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CIRP ANNALS 1993

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 STC A 

A module for the automated planning of grasps in robotized assembly operations
G. Dini (2)  
STC A,  42/1/1993,  P.1
Keywords: Automatic Assembly, Grippers, Planning
Abstract : This paper reports on the development of a software module able to select the surfaces of an object to be grasped by a robot and to generate the optimal configuration of a two-jaw gripper. The various aspects involved in the direction of the surfaces for gripping are analyzed and discussed: surface geometry, orientation, position with respect to the centroid of the object, etc. In particular, the methods and the advantages obtained in the application of the fuzzy logic for the selection of the surfaces that assure a stable and accessible grasp are described. Furthermore, the methodology adopted for a parametric configuration of the main features of the gripper is explained. At the end, some meaningful examples of results are reported and discussed.
Grasping and walking finger manipulation of objects using four-fingered hand
N. Brook, M. Shoham, J. Dayan   / R. Weill (1)
STC A,  42/1/1993,  P.5
Keywords: Robots, Grippers
Abstract : Options for grasping an object are restricted by the surface on which the object is placed. There is a frequent need therefore, to manipulate the object from an initial lifting grasp to a final working one. We present here an algorithm for finding the three-finger force-closured grasp space of polygonal objects for arbitrarily small friction (certain particular solutions for smooth objects are also given). Using a graphical representation of the grasp space we determine conditions for manipulating an object from one grasp to another with four fingers and arbitrarily small friction. Planning possibilities for the manipulation process are also presented.
A 2-D mapping approach for monitoring and diagnosing the execution of robotic assembly task
H.A. ElMaraghy (1), A. Syed, H. Chu, W.H. Elmaraghy  
STC A,  42/1/1993,  P.9
Keywords: Robotic Assembly, Diagnosis, Neural-Networks
Abstract : Assembly task planning is concerned with generating the sequence of operations and the required detailed execution instructions. Realtime monitoring, and diagnosing of uncertain events, based on the latest feedback from sensor (vision, tactile, force, etc.), during robot assembly tasks Execution plays a vital role in ensuring a reliable and robust assembly. This paper presents techniques developed for realtime monitoring of assembly operations, direction of errors due to parts mishandling such as incorrect parts manipulation, insertion and placement in the workspace or due to interference between robots sharing the workspace. Two-dimensional maps are created bv adaptative projecting the typically three or more dimensional assembly problems to a simpler two-dimensional problem space which provides the flexible and efficient associative properties needed for effective realtime monitoring and diagnosis. A self-organizing neural network (Kohonen map) is used for organizing the various inputs regarding parts, tools and sensors feedback during robotic assembly and diagnosing the sources of errors. Re-planning of the assembly to recover front errors would then proceed based on this feedback. The results of this research have been demonstrated in thee real assembly of a dishwasher power unit.
Automatic generation of assembly constraints and cooperation task planning
S.Y. Nof, V.N. Rajan   / E. Lenz (1)
STC A,  42/1/1993,  P.13
Keywords: Assembly Analysis, Multi-Robot Systems, Cooperation, Optimal Planning
Abstract : Cooperation is considered an essential attribute of intelligent multi-robot systems. It enhances their flexibility and reliability. The Cooperation Requirement Planning (CRP) process consists of two steps: CRP-I for generating the assembly, robot, and cell constraints, and the cooperation requirements; and CRP-II for performing task assignment, and generating a consistent and coordinated global plan for task execution. In this paper, we describe the CRP-I methodology which takes the assembly and multi-robot cell information to generate the constraints and the cooperation requirements. For a given assembly, its geometric model is analyzed to generate the minimal set of geometric precedence constraints. The geometric, physical, and operational requirements of the assembly tasks are then matched with the corresponding capabilities of the various robot sets in a given multi-robot cell to generate the robot and cell constraints, and the cooperation requirements. The CRP-I methodology has been implemented using the ROBCAD^© robotic graphical simulation package Open-System Environment on a Silicon Graphics IRIST^© 4D / 80GT graphics workstation.
Adaptive genetic algorithm for optimal printed circuit board assembly planning
N. Wong, M.C. Leu (2)  
STC A,  42/1/1993,  P.17
Keywords: Assembly Machines, Algorithms, Optimization
Abstract : We present a novel application of the genetic algorithm approach for solving the problem of planning optimal placement-insertion sequence and machine setup in printed circuit board (PCB) assembly The algorithm starts with feasible solutions and utilizes genetic operators to iteratively generate potentially better solutions in the optimization process, similar to the biological evolution process. We first describe the basic algorithm and its application to optimal planning for some popular PCB assembly machines We then describe an adaptive genetic algorithm, which has its rates of genetic operators changed automatically during the iterative optimization process_ We use a Wilcoxon signed rank test to show its performance improvement over the fixed-rate genetic algorithm.
CLIR - Clean room industrial robot for handling and assembly in semiconductor industry
N. Roth (2), B. Schneider  
STC A,  42/1/1993,  P.21
Keywords: Robots, Assembly Lines, Clean Room, Contamination, Process Quality, Semiconductor mask, Pellicle
Abstract : In many technical areas innovation is characterized by an increasingly progressing miniaturisation leading to a situation, that a growing spectrum of products has to be produced under clean room conditions. Technical as well as economic reasons are responsible for the necessity to automize large areas of that type of production, because even under protective measures human workers produce an unacceptable amount of pollution in clean rooms. Industrial robots can be used in clean rooms, but they have to be designed or at least to be largely modified to meet the requirements. In this paper development and technical features of such robot systems are described and results from an application in assembly tasks within semiconductor production are discussed.
Flexible solutions for wiring harness assembly with industrial robots
H.J. Warnecke (1), H. Emmerich, S. Koller  
STC A,  42/1/1993,  P.25
Keywords: Automatic Assembly, Wiring, Flexibility
Abstract : The wire harness assembly process has not changed fundamentally for many years. All procedures except the pre-assembling of the individual wires are done by hand. The labor-costs of wiring are very high in comparison to the total costs of the assembly process. A pilot work station for the fully automated direct-assembly of wires into fluorescence lights has been developed. With the aid of a new connection technology and the help of an industrial robot and special tools the direct-assembly of individual wires into the light cases is possible. First test results show that the procedure of the direct-assembly works with a high availability and that this procedure is more cost effective in comparison to the traditional wiring harness assembly in many fields.

 STC C 

Chip formation in the machining of hardened steel
M.C. Shaw (1), A. Vyas  
STC C,  42/1/1993,  P.29
Keywords: Cutting, Cubic Boron Nitride (CBN), Chip Formation
Abstract : With the availability of polycrystalline cubic boron nitride (PCBN) it is possible to machine very hard gears, etc at speeds of (60-150 m / min = 200-500 fpm). When this is done using PCBN tools in face milling, chip formation is of a cyclic saw toothed type. This type of chip formation is reviewed in relation to other types of cyclic and noncyclic chip formation. The root cause of high frequency, saw toothed chip formation is found to be periodic gross shear fracture extending from the free surface of the chip toward the tool tip and not adiabatic shear as commonly believed.
Rigid-plastic FEM analysis of three-dimensional deformation fiels in chip formation process
K. Ueda (2), K. Manabe  
STC C,  42/1/1993,  P.35
Keywords: Cutting, Finite Element Method, Chip Formation
Abstract : A three-dimensional deformation field in the chip formation process is analysed by the Rigid-Plastic Finite Element Method. By developing a three-dimensional model of the work material, the deformation field in oblique cutting is continuously analysed for the transition process from the beginning of the cutting until the steady state. The variations in the chip geometry and cutting forces due to the inclination angle of the cutting edge are simulated for a carbon steel. The simulation results are compared with in-situ scanning electron microscope observations of the cutting experiments, and good correlation between them is found.
Turning versus grinding - A comparison of surface integrity aspects and attainable accuracies
V. König (1), A. Berktold, K.F. Kich  
STC C,  42/1/1993,  P.39
Keywords: Hard Machining, Surface Properties, Accuracy
Abstract : In the past decade, the technology of machining hardened steels with geometrically defined cutting edges has been developed. Despite its high potential to increase productivity as well as competitiveness, the industrial use is still low. That is because the effects of hard machining on surface integrity aspects and the attainable accuracies are not well understood. In this paper, the characteristics of hard machined surfaces - especially of 'white layers' - will be discussed and compared to those which are ground. Furthermore, the development in the area of high precision machining of hardened steels will be presented.
Automatic chip breaking detection in turning by frequency analysis of cutting force
J.L. Andreasen, L. De Chiffre (2)  
STC C,  42/1/1993,  P.45
Keywords: Turning, Chip Control, Cutting Forces
Abstract : An automatic system for chip breaking detection in turning has been developed for use in the laboratory. The system utilises a detection technique based on frequency analysis of the dynamic feed force component. The ability to identify chip breaking has been demonstrated using different lathes, cutting tools, workpiece materials and cutting data.
Computer-aided predictive models for fundamental rotary tool cutting processes
E.J.A. Armarego (1), V. Karri, A.J.R. Smith  
STC C,  42/1/1993,  P.49
Keywords: Cutting, Mechanics, Rotary Tools
Abstract : Mechanics of cutting analyses fur fundamental `self-propelled' and driven rotary tool cutting processes aired at coining an understanding of the practical rotary tool turning and face milling operations are presented. It is shown that these fundamental rotary tool processes can be directly related to the `classical' orthogonal and oblique cutting processes used to study the fundamentals cf conventional machining and develop predictive yodels for the more complex practical -turning, drilling and milling operations. Based on the unified mechanics of cutting approach, computer-aided cutting models for predicting the force components, power and chip flow angle in -he fundamental rotary tool processes are discussed, experimentally verified and numerically studied. The difficulties of extending these models to the practical rotary tool operations are briefly discussed.
Optimization of precision machining by simulation of the cutting process
H. Schulz (1), K. Bimschas  
STC C,  42/1/1993,  P.55
Keywords: Precision Cutting, Simulation, Preventive Optimization
Abstract : In order to produce high precision workpieces, sources of error are made apparent through preventive simulation of the planned cutting process. Machining optimization prior to the start of production is thereby made possible, The simulation program developed by the Institute for Production Engineering and Machine Tools (PTW) is based on a permanent work-proceeding simultaneous transfer of force caused by the cutting forces onto the present workpiece geometry. In order to improve the precision of the workpiece the entire manufacturing system "machine tool - workpiece - tool - clamping device - cutting technology - sequence of operations" must be considered. The simulation of workpiece machining and the optimization processes required to achieve higher precision will be demonstrated. Utilization of this preventive simulation method can gradualy reduce workpiece form failures.
Estimation of cutting tool life by processing tool image data with neural network
T. Teshima, T. Shibasaka, M. Takuma, A. Yamamoto   / K. Iwata (1)
STC C,  42/1/1993,  P.59
Keywords: Tool Life, Neural Networks, Image Processing
Abstract : In the manufacturing Systems such as FMS, one of the most important issues is to estimate the rest of cutting tool life under a given cutting conditions as accurately as possible. In this paper, a system based on neural network is proposed to estimate the life and wear type of cutting tools from their image data and cutting conditions. The input of the system is the states of a cutting tool, crater wear and flank wear, obtained as image data, and the cutting conditions. The validity of the system was confirmed by the examinations Under various cutting conditions in turning.
Reliability improvement of tool-wear monotoring
A. Novak (1), H. Wiklund  
STC C,  42/1/1993,  P.63
Keywords: Process Monitoring, Tool Wear, Statistical Analysis
Abstract : A method for on-line reliability evaluation of flank-wear measurements and for immediate adjustment of improper data is presented in the paper. Direct flank-wear measurements by a developed vision system and the indirect sensing of tool condition by teed force measurements are two simultaneously evaluated signals when two sources of possible measurement errors are introduced and used for reliability estimates of the acquired data. Optimum settings of two parameters involved in the signal conditioning strategy are calculated by applying response surface methodology (RSM) and a suitable tool-wear model. The described method has been applied to several machinability tests performed during turning. A significant increase of monitoring adequacy when compared with the traditional way of monitoring has been verified. The accuracy and reliability of tool-wear monitoring by the developed vision system, operating on the machine tool on-line, has been improved as disclosed by the presented results.
Unsupervised neural network for tool breakage detection in turning
V.B. Jamu, K. Danai   / S. Malkin (1)
STC C,  42/1/1993,  P.67
Keywords: neural network
Abstract : Ali unsupervised neural network is introduced for on-line tool breakage detection in machining using multiple sensors. This neural network performs detection by classifying the measurements either as normal or abnormal. However, it performs classification by relying only on the normal category, so that it does not need to establish the abnormal category requiring samples of measurements taken at tool breakage. This/ Single Category-Based Classi//fier (SCBC) /also adapts the prototype values on-line so as continuously update the normal category, and employs the noise suppression technique: /contrast enhancement and voting,/ in order to cope with different levels of noise in measurements. The performance of the SCBC is evaluated in turning. Extensive tests were performed which produced six tool breakage cases. Four measurements which were clear indicators of tool breakage in these tests were used as inputs to the SCBC and to two other classifiers utilizing Kononen's Feature Mapping and Adaptive Resonance Theory (ART2). The results indicate that the SGBC was the only classifier that could detect all of the tool breakages.
On multi-sensor approach to drill wear monitoring
A. Noori-Khajavi, R. Komanduri (1)  
STC C,  42/1/1993,  P.71
Keywords: Drill Wear Monitoring, Sensors, Neural Network, Sensor Fusion
Abstract : Single sensors were investigated in the past for their potential for monitoring drill wear. Since, signals from different sensors may capture wear differently at different stages of its life, sensor fusion concept was advanced recently using multiple sensors. In this investigation, this concept was explored in drilling using four sensors, namely, thrust, torque, and strains in two orthogonal directions to the drill axis (i.e., the X- and Y-directions on the table of a CNC milling machine). The signals were analyzed in the time and frequency domains. In the frequency domain, the Power Spectral Density (PSD) of sensor signals showed good correlation with drill wear while in the time domain no significant changes were observed between a sharp and a worn tool Also, the signal-to-noise ratio analyses in the frequency domain at different states of drill wear indicated that as the drill wear increases the noise also increases. It was shown that when noisy sensor signals were integrated (instead of using one sensor signal) using a neural network, it may actually result in the deterioration of the correct estimation of drill wear. Consequently, it appears that integration of the sensor signals under these conditions may not be appropriate and a single sensor may be adequate.
Combined stress, material flow and heat analysis of orthogonal micromachining of copper
T. Moriwaki (1), N. Sugimura, L. Sheng  
STC C,  42/1/1993,  P.75
Keywords: Cutting, Micromachining, Finite Element Method
Abstract : Theoretical and experimental analyses of orthogonal micromachining of copper are presented to promote fundamental understanding of ultraprecision metal cutting process. A method is proposed by applying the rigid-plastic FEM to analyze the mechanics of steady state orthogonal micromachining process of copper taking into consideration of the roundness of the tool edge. An FEM model is also developed to analyze the flow of cutting heat and the temperature distribution within both the workpiece and the .tool based on the stress and the material flow within the workpiece calculated. Orthogonal micromachining experiments are carved out by employing both a micromachining equipment installed within SEM (Scanning Electron Microscope) and an ultraprecision fly cutting machine. The results of the FEM analysis are compared with the experimental results.
Mechanics and energy dissipation in nanoscale cutting
T. Inamura, N. Takezawa, Y. Kumaki   / N. Ikawa (1)
STC C,  42/1/1993,  P.79
Keywords: Simulation, Micromachining, Cutting
Abstract : The methods by which to evaluate energy dissipation and stress/strain distribution in nanoscale cutting have been presented and applied to the results of atomic-model-based simulation of nanoscale cutting. The results thus obtained show that the rate of energy dissipation in plastic deformation under a tool is large compared with that in macroscale cutting but that the value for surface generation is still small. The results also show that the stress-and-strain distribution in nanoscale cutting is consistent with that of macroscale cutting except that there is almost no concentrated shear stress in the primary shear zone.
Effect of tool edge geometry on energy dissipation in ultraprecision machining
D.A. Lucca, Y.W. Seo   / R. Komanduri (1)
STC C,  42/1/1993,  P.83
Keywords: Cutting, Cutting Forces, Diamond
Abstract : An experimental study of die effect of single crystal diamond tool edge geometry on the resulting cutting and thrust forces and specific energy in the ultraprecision orthogonal flycutting of Tc-Cu was made. The effects of both the nominal rake angle and tool edge profile were investigated over uncut chip thicknesses from 20 µm down to 10 nm. Characterization of the tool edge was performed with the use of atomic force microscopy. Both the nominal rake angle and tool edge profile were found to have significant effects on the resulting forces and energies.
Development of an advanced tool setting device for diamond turning
M. Sawa, Y. Maeda, M. Masuda, R. Ito   / T. Moriwaki (1)
STC C,  42/1/1993,  P.87
Keywords: Aluminium Alloys, Diamond Tools, Diamond Turning Machines, Ultra-Precision Machining
Abstract : This paper describes development of an advanced tool setting device for diamond turning. In order to machine a magnetic recording disk substrate (Al-Mg alloy) to a mirror-finished surface of less than 0.03 µm Rmax using a diamond cutting tool, a mechanism has been developed for automatic adjustment of the tool setting angle, which is a very important factor to obtain a smooth machined surface. The adjustment of the tool setting angle, which has previously been done by skilled operators, is now automated and the angular tolerance subjected to the tool replacement has been improved to an accuracy of ± 1.4 x 10^- 3 degrees. The machined surface roughness has also been improved to less than 0.03 pm Rmax. Moreover, the time required for the tool setting angle adjustment has been shortened to 5 minutes as compared to between 15 and 45 minutes required by the conventional manual adjustment.
Feasibility study on ultimate accuracy in microcutting using molecular dynamics simulation
S. Shimada, N. Ikawa (1), H. Tanaka, G. Ohmori, J. Uchikoshi, H. Yoshinaga  
STC C,  42/1/1993,  P.91
Keywords: Cutting, Micromachining, Computerized Simulation
Abstract : Using molecular dynamics computer simulation, the feasibility is analyzed on nanometric or an ultimate machining accuracy attainable in microcutting of free machining workmaterials under perfect motion of a machine tool; Based on the analysis, the microprocess of chip and surface generation can be well understood from the atomistic point of view. The minimum thickness cf cut, that is a measure of the accuracy attainable, can he expected to be about 1 nm or less, that is, 1/20 to 1/10 of the edge radius of a realistic fine cutting edge available. The ultimate roughness and depth of deformed layer of worksurface is estimated to be about 0,5 nm and 5.0 nm, respectively. The quality of worksurface of aluminum is worse thin that of copper These results suggest that the ultraprecision metal cutting the machining accuracy of which is at least 1 nm is feasible.
A consideration of tool wear mechanism when machining metal matrix composites (MMC)
K. Weinert   / W. König (1)
STC C,  42/1/1993,  P.95
Keywords: Composites, Machining, Tool Wear
Abstract : The chip formation is very important for the comprehension of tool wear mechanism when machining MMC. The real area of contact during the chip formation is not well known. Therefore a clear determination of the type of wear is only possible after a well-founded investigation on the wear appearances. These investigation have shown important differences if the hardness of the reinforcement material is higher or lower than the hardness of the cutting material. Furthermore the relation of the reinforcement particle size and the grain size of the cutting material influences the wear mechanism and the wear appearances.
Performance of whisker-reinforced ceramic tools in milling nickel-based super alloy
M.A. Elbestawi (2), Di Yang, Min Tan, T. Elwardany  
STC C,  42/1/1993,  P.99
Keywords: Cutting, Tool Wear, Ceramics
Abstract : This paper investigates failure characteristics and cutting performance of silicon carbide whisker-reinforced ceramic tools during milling of Inconel 718. Cutting tests were performed using round and square inserts, at cutting speeds ranging from 200 to 700 m/min, and feeds from .05 to .15 mm/tooth. Various immersion ratios were also considered. Tool wear was examined under the various cutting conditions. The behaviour of the cutting forces and temperatures during machining were then examined. The results show that an improved performance was obtained using the round inserts in comparison with the square ones. Modes of tool failure were found to be depth of cut notch wear and trailing edge wear. The former wear was dominant at cutting speeds from 200 to 400 m/min while the later wear was dominant at speeds from 400 to 700 m/min. Flank wear was mainly due to adhesion of workpiece material on the tool surface. The best performance was achieved at a speed of 700 m/min, feed of 0.15 mm/tooth and 1.25 mm depth of cut.
High speed machining of inconel 718 with ceramic tools
N. Barutaki, Y. Yamane, K. Hayashi, T. Kitagawa   / K. Uehara (1)
STC C,  42/1/1993,  P.103
Keywords: Nickel Alloys, High Speed Machining
Abstract : High speed machining for Inconel 718 was carried out with SiC whisker reinforced alumina, silicon nitride and TiC added alumina ceramic tools. In this test, not only the commercial available inserts, square type 120408 or button type 120400, but also specially designed cutting edges were tried. The SiC whisker tool showed the best performance in respect of notch wear at the cutting speed of under 300m/min. However, when the speed exceed 400m/min., the TiC added alumina ceramic tool showed the smallest wear compare to other tools. Specially designed cutting edge made the notch wear small.
Ultra-precision machining of SiCw/Al composites
Z.J. Yuan (1), L. Geng, S. Dong  
STC C,  42/1/1993,  P.107
Keywords: Composites, Cutting, Ultra-Precision machining
Abstract : images/cirpfichiers/annals/SiCw/Al composite is a new material which has high strength and low weight. In ultra-precision machining of the SiCw/Al composites with single point diamond tool (SPDT), surface finish of Ra =0.0l ?m is reached. In precision machining of the SiCw/Al composites, the effections of percentage and direction of the SiC whisker and the cutting parameters on cutting surface integrity of the SiCw/Al composites are studied. The mechanism of cutting deformation of the SiCw/Al composite is also searched with SEM and TEM analysis.
Theoretical consideration of rare earth metal compounds as tool materials for titanium machining
B. Kramer (2), D. Viens, S. Chin  
STC C,  42/1/1993,  P.111
Keywords: Tool Wear, Titanium Alloys
Abstract : Previous work has suggested that tool materials that are effective in the machining of titanium, such as tungsten carbide and diamond, promote seizure between the tool and chip, producing a diffusion-limited, low wear regime. Another strategy for decreasing tool wear is to identify materials that have high chemical stability with respect to titanium. Some rare earth metals are known to have relatively high enthalpies of solution in titanium and their compounds are expected to have corresponding low solubilities. Although much needed data concerning the chemical and mechanical properties of rare earth compounds is unavailable, the paper represents an attempt to evaluate the potential of various rare earth metal compounds as tool materials for titanium machining, on the basis of the limited available data.
Proposition of a method to optimize the machining of XC42 steel with laser assistance
J.F. Gratias, L.J. Fan, G. Marot, p. Cohen, A. Moisan (1)  
STC C,  42/1/1993,  P.115
Keywords: Laser Beam Cutting, Material Finishing, Optimization
Abstract : This paper presents a method which permits to obtain relationships between the main parameters to be considered during machining of steel with laser assistance - the cutting speed, the laser beam power, the melting temperature and the austenitic transformation temperature of the machined material - in order to optimize the process. From a theoretical approach and from experimental results obtained in turning with laser assistance, laser power-cutting speed relations are established, defining a zone in which the influence of the energy supplied by the laser is most significant on the cutting force. Decreases of the cutting force components up to 70%37; are observed, in proving the efficiency of machining with laser assistance, principally in the case of hard-strength materials.

 STC Dn 

Development of machining-productibility evaluation method (MEM)
S. Arimoto, T. Ohashi, M. Ikeda, S. Miyakawa   / M. Kiuchi (1)
STC Dn,  42/1/1993,  P.119
Keywords: Design, Productibility, Processability
Abstract : The Machining-productivity Evaluation Method (MEM) was developed to assess design quality for easier processing of parts and products. It has been effectively used in the Hitachi Group and other companies. MEM covers cutting (turning) and grinding, sheet metal working, welding, molding, die casting, and casting. It features: 1) quantitative evaluation using easy to understand 100 points evaluation scale and estimated processing cost index. 2) method is easy to both learn and use, using approximately 20 basic symbols 3) concurrent calculation of processing coast for workshop with indices.
A nex concept for design of sheet metal products
M. Shpitalni (1)  
STC Dn,  42/1/1993,  P.123
Keywords: Design, CAD/CAM, Sheet Metal
Abstract : An interactive CAD/CAM system dedicated to the design and manufacture of sheet metal products has been developed. This paper discusses the unique method used by the system for product definition. The product is defined based on the principles of zero thickness and zero bend radii as well as on manufacturing constraints. First, the product is defined in 2-D using nominal dimensions. Then, transformation from the 2-D nominal layout to the real 3-D product is performed by means of manufacturing constraints. These constraints, including bending, welding, and critical dimensions, introduce an important aspect of design for manufacturing.
Design and application of a prototype system for concurrent engineering in a small firm
W. Gijsels, W.R. De Vries (2)  
STC Dn,  42/1/1993,  P.127
Keywords: Concurrent Engineering, Process Planning, Data Base
Abstract : Efforts to develop an integrated or concurrent engineering approach to design and manufacturing often focus on large systems in large firms. However smaller firms can also benefit from this approach. In this paper we propose a database structure for handling the design of small mechanical parts to be produced on a flexible manufacturing system. The database the information on geometric models of part designs, models for tools and fixtures manufacturing operations and detailed process plans which are developed simultaneously. This prototype database structure and planning system have been developed to run on an IBM PS/2 or equivalent. This paper outlines the data structure design and the planning assumptions that are made to implement such system. The system is illustrated by applying it to realistic part designs.
Systematization of design knowledge
H. Yoshikawa (1)  
STC Dn,  42/1/1993,  P.131
Keywords: Design, Computer Aided Design, Knowledge Based System
Abstract : It is expected that future design/manufacturing systems should be autonomous, metamorphological, self-organizing, self-maintaining/recovering, and intelligent. To develop such systems, the concept of knowledge intensiveness plays a crucial role. Developing knowledge intensive systems requires building large scale knowledge bases on manufacturing and design. Our experiences with developing a large scale design knowledge base for intelligent CAD systems show, however, that without systematizing design knowledge it is impossible even just to collect knowledge. This paper discusses aims, goals, and roles of design knowledge systematization and proposes a systematization methodology. Some preliminary results are also described.
A generic mechanism model for use in a CIM environment for the development of mechanized production machines
W. Zhang, K. Van Der Werff   / C.A. Van Luttervel (1)
STC Dn,  42/1/1993,  P.135
Keywords: Mechanism, Model, Database
Abstract : In production machines mechanisms are important components. Such mechanisms have to be designed taking into account many different aspects. Communication with many other specialists may be required. A project called "computer integrated manufacture of mechanism (CIMOM)" was started at TU Delft. The goal of this project is to develop a computer-based information system to support all activities necessary for the integrated and automated design and manufacture of mechanisms. A generic model for mechanisms plays an essential role in the CIMOM environment. This paper focuses on the formulation of this mechanism model. Database technology is used. The conceptual schema of the mechanism model is presented. Some prototype implementations are reported to prove the effectiveness of this model.
Customerbased design with constraint reasoning
G. Sivard, L. Lindberg, E. Agerman (2)  
STC Dn,  42/1/1993,  P.139
Keywords: Interactive Design Systems, Automated Design, Constraint Logic Programming
Abstract : This paper identifies some principles for computer-aided customer-based design. In this type of design, technical prerequisites and the range of customer requirements are typically the same over time. From time to time there are larger changes in manufacturing methods and customer needs, though. Thus the degree of automation to a design support system can be fairly large, but it still needs to be interactive and flexible for changes. A test-case based on an industrial application, implemented using a commercial CAD system and a CLP (Constraint Logic Programming) system, is described. Special emphasis is put on interactivity- the collaboration between designer and automated design system.
A CAD for functional design
T. Tomiyama, Y. Umeda   / H. Yoshikawa (1)
STC Dn,  42/1/1993,  P.143
Keywords: Design, Conceptual Model, Function
Abstract : Although functional design (or conceptual design) is crucial to whole design process, traditional CAD technology based on geometric modeling does not support this process because of difficulty of dealing with function. This paper proposes a new methodology to deal with function, called FBS (Function-Behavior-State) modeling and describes a computer tool support functional design based on the FBS modeling. Importance and advantages of the FBS modeling is clarified by demonstrating two examples. One is the design of functionally redundant machines and the other is the automatic generation of control software for mechatronics products.
Product and process modelling as a kernel for virtual manufacturing environment
F. Kimura (2)  
STC Dn,  42/1/1993,  P.147
Keywords: Product Engineering, Computer Models, Computer Integrated Manufacturing
Abstract : For coping with severe requirements for future manufacturing systems, it is effective to model necessary product behaviour and associated manufacturing processes by computer as precisely as possible, and to predict potential problems for product functionality and manufacturability before making real manufacturing. This approach is called as virtual manufacturing. In this paper, a set of models pertinent for realizing virtual manufacturing environment is introduced. Among them product and process modes are discussed in some details as a kernel. Product models represent every artifact which appears during manufacturing, and process models are associated with them to derive their properties and behaviour. Some examples are given to show the effectiveness of virtual manufacturing.
Methods for quality driven product development
F. L. Krause (2), A. Ulbrich, R. Woll  
STC Dn,  42/1/1993,  P.151
Keywords: Design, Quality Assurance, Product Development
Abstract : This paper introduces approaches for the integration of the QFD and FMEA methods as well as feedback with system components for computer aided product development. The integration is based on information models representing product, process and factory information. These information models will be extended by requirements and failure models to support the above mentioned quality assurance methods. A quality information model for company-wide information delivery is defined and forms the control of the quality driven product development process by integration of a system component for quality control.
Process driven engineering - A key element in integrating design and manufacture
A. Geddam, S. Kaldor (2)  
STC Dn,  42/1/1993,  P.155
Keywords: Process Driven Design, Design For Manufacture, Precision Machining
Abstract : Traditionally, design and development activity has been and still is completely separated in many places from engineering and from production. This has often led to dead ends when production could not keep up with requirements due to lack of suitable processes. Further, in the past, this could not happen since it was natural to develop and build prototypes in the manufacturing environment and through help from manufacturing personnel. Modern trends like concurrent engineering emphasize free information flow between production engineering and design, aimed at an integrated approach to design and manufacture. This paper deals with design and engineering methods which are based on available and specific processes. Examples from the fields of inertial devices and thermal imaging are discussed.
Notes on concurrent engineering
L. Lindberg   / G. Sohlenius (1)
STC Dn,  42/1/1993,  P.159
Keywords: Concurrent Engineering, Design, System Theory
Abstract : This paper discusses Concurrent Engineering from a system perspective. The approach is to use analogies to control systems to illustrate central problems in Concurrent Engineering. 'Notation' is then presented as a useful concept to discuss the representation of the data flowing in the manufacturing system. This also shows that to perform a quantitative analysis a formal definition of information is needed, with an associates measure of it.
The life cycle concept as a basis or sustainable industrial production
L. Alting (1), J. Jorgensen  
STC Dn,  42/1/1993,  P.163
Keywords: Product Development, Design, Life Cycle, Environment
Abstract : The Life cycle concept will become the backbone in a new industrial culture named sustainable production. Sustainability means that products are designed for their whole life cycle i.e. production, distribution, usage and disposal with minimized (acceptable) influence on the environment, occupational health and use of resources. A key element in this new engineering life cycle approach is a method/ tool to assess and evaluate environmental. occupational health and resource consequences in all life cycle phases at the product development stage. In this paper a preliminary method for evaluating environmental consequences containing the major environmental effects is presented. The method outlined quantifies the term "environmental friendly" so it can be used as a "yardstick" in evaluating different technical solutions. The complex problems in the final design decisions are discussed and future perspectives outlined.
Evolving issues in product life cycle design
V.A. Tipnis (2)  
STC Dn,  42/1/1993,  P.169
Keywords: Product Design, Process Design, Environmental Impact, Competitive Strategies, Concurrent Engineering, Economic Model, Penalty Costs
Abstract : Driven by the global environmental movement and consumer preferences to `green labeled products', a new paradigm has emerged:{`GREEN' ROBUST PRODUCTS} plus {CLEAN PRODUCTION) equals (SUSTAINABLE GROWTH}.This paradigm evolved from the growing environmental regulations and occupational health and safety laws that restrict gaseous, liquid, and solid emissions and waste disposals from manufacturing processes and products in-use and -disposal. Also, disposal of product packaging and recycling of used products is forcing the rethinking of the entire product life cycle from product strategy to recycling/disposal. There is a growing recognition of the fact that the competitive position and, indeed, the very, survival of companies depend on their response to this paradigm. This new paradigm is named the paradigm 'E' because to adopt it, a corporation must emphasize Ecology, Environment, Energy, Economy, Empowering, Education, and Excellence in all product fife cycle decision. Responding to this paradigm poses several new challenges beyond the traditional role and expertise of most product designers and production engineers. In this paper, the evolving issues of the paradigm and their impact on product design and production are examined. The steps necessary for the adoption of die paradigm 'E' are presented. A review is presented of the available methodologies and analysis tools for making evaluation of environmental impact, product life cycle economics, and corporate competitive positioning. Activity modeling which provides a comprehensive methodology for these investigations is illustrated through sample outputs from an on-going industrial implementation of the Paradigm 'E'.
Information-based design for environmental problem solving
D.R. Wallace, N.P. Suh (1)  
STC Dn,  42/1/1993,  P.175
Keywords: Design, Axioms, Design Requirements
Abstract : Axiomatic design is a general method that helps designers structure and understand design problems, thereby facilitating the synthesis of suitable design requirements, solutions, and processes. The approach also provides a consistent framework from which the merits of designs can be quantified. In this paper we briefly review the tenets of axiomatic design, and demonstrate how information content can he applied to environmental design problems - an issue that is becoming increasingly important. A prototypical computer program is used to illustrate the approach.
Life-cycle-analysis : a strategic element for future products and manufacturing technologies
H. Weule (1)  
STC Dn,  42/1/1993,  P.181
Keywords: Ecology, Life-Cycle-Analysis, Design Requirements
Abstract : Environmentally clean products and manufacturing technologies are vital in order to be competitive in the future. Beside functional requirements product design must be more and more oriented on ecological effects throughout the life-cycle of products. Life-cycle-analysis permits the comparison and evaluation of various alternatives from the ecological and economical point of view. The method for life-cycle-analysis is illustrated. For two alternative suction tubes for a vacuum cleaner the first approach for an "ecobalance" is outlined.
3D shape reconstruction for recognition of freehand machine drawings
T. Honda (2), S.I. Kaneko, Y. Takeda  
STC Dn,  42/1/1993,  P.185
Keywords: Drawing, Design, Vision
Abstract : An algorithm to reconstruct three dimensional geometries of machine parts based on the two dimensional data generated from two orthographic projection views of machine drawings has been developed, and implemented to a system for recognition of freehand written machine drawings that has been under research and development by the authors since 1984. For machine parts with geometrical elements of planes, cylindrical surfaces and holes, the system can generate the overall 3D shapes from the two orthographic projection views data under some restrictions. In this paper, the algorithm is shown with some test results. Furthermore, the evaluation of the computing time is discussed comparing the theoretical estimation with the actual measurement.
Performance rating of spur gears with non-standard proportions and profiles
M.A.S. Arikan (2), O.Uyar Carkoglu  
STC Dn,  42/1/1993,  P.189
Keywords: Gears, Gear Cutting
Abstract : Although it is common practice to design gears with standard proportions and cut them by using standard cutters and machines, considerable performance improvements can be obtained either by designing and cutting gears with non-standard proportions, i.e. gears with addendum modifications: or by relieving their tips and/or roots. In this study, effects of designing and cutting with non-standard proportions, and giving tip and/or root reliefs on performance of spur gears are investigated by using gear tooth models formed by using the geometry of the canter. Variations of dynamic loads on spur gears during a mesh cycle of a tooth, is found by using an analytical model based on torsional vibrations of gears. Finite element method is used to find the variable stiffness of gear tooth and to make the stress analysis. Bending deformations of gear bodies and supporting shafts, bearing deformations, torsional deformations of gear bodies, and contact deformations of teeth are also included in stiffness calculations.
Skeleton-based design analysis of near net shape products
C.N. Chu, J.M. Lee (2), R.L. Kashyap  
STC Dn,  42/1/1993,  P.193
Keywords: Design, Near Net Shapes, Productability
Abstract : In this paper, we present a parallel thinning algorithm for design analysis of near net shape products. The parallel thinning algorithm allows extraction of global topology of a three dimensional geometry. In this scheme, the geometry is digitized and a skeleton line of the geometry is extracted by preserving the Euler characteristics and connectivity. The extracted skeleton allows a design evaluation system to utilize heuristic manufacturing knowledge base. Finally, we construct a skeleton model and present its application to casting and forcing design analysis.

 STC E 

Progress toward clean technology for photochemical machining
D.M. Allen (2)  
STC E,  42/1/1993,  P.197
Keywords: Environmental Impact, Etching, Waste Treatment
Abstract : In order to compete with traditional mechanical methods of manufacture, photochemical machining has undergone many process modifications in order to comply with a plethora of legislation and regulations aimed at protecting the environment. These modifications have greatly reduced the environmental impact of the process and the drive to reduce it further continues. This paper describes the cleaner photographic, metal preparation, coating and etching technologies that have been developed and includes details of current research directed towards economic recycling of spent etchants.
A finite element simulation of the electrochemical machining process
H. Hardisty, A.E. Mileham, H. Shirvani   / A.N. Bramley (1)
STC E,  42/1/1993,  P.201
Keywords: Electrochemical Machining, Finite Elements, Simulation
Abstract : The paper describes package based on the FEM (Finite Element Method), which simulates the Electrochemical Machining (ECM) process. The FEM is used to determine the two-dimensional potential and flux distribution in the electrolyte, in order to estimate surface erosion for a finite time-step. Algorithms have been developed which automatically change the F.E. mesh, to simulate moving boundaries for tool movement and workpiece erosion. The complex flux distributions produced in the electrolyte have yielded considerable insight into the erosion process for the tool shapes used unpractice.
Depth prediction in laser machining with the aid of surface temperature measurements
G. Chryssolouris (1), A. Yablon  
STC E,  42/1/1993,  P.205
Keywords: Laser Machining
Abstract : This paper discusses a method for estimating the groove depth in laser machining processes based on temperature measurements. The temperature field was measured through infrared thermography. An analytical model relating temperature to groove depth was used to predict the groove depth given a temperature measurement and its location. Theoretical and experimental results are compared and discussed.
Dynamic stability of the technological machining system in EDM
S. Enache (1), C. Opran  
STC E,  42/1/1993,  P.209
Keywords: EDM, Technological Oscillations, Dynamic Stability
Abstract : The paper presents the results of the theoretical and experimental research concerning the physical model, the transfer functions and the equations of the dynamic stability on processing in EDM. It also deals with the influence of the electro-technological factors upon the technological oscillations, characteristic of the tool-electrode of the EDM.There is also shown the influence exerted by these technological oscillations on the productivity, roughness of the machined surface and manufacturing precision. This is a continuation of the paper introduced at CIRP 1990.
Thin plate welding by a high-power-density small diameter plasma arc
S. Yoshioka, T. Miyazaki, T. Kimura, A. Komatsu, N. Kinoshita (1)  
STC E,  42/1/1993,  P.215
Keywords: Plasma Arc Welding, Tolerances, Control
Abstract : High-power-density plasma arc of 10^4 W/mm² (10^6 W/cm²) is applied to welding of stainless steel plate of 0.1 and 0.3 mm in thickness. Practical conditions required for successful welding and welding capability of this new equipment are discussed. Welding capability does not depend on the working distance defined as the distance between exit of nozzle and workpiece surface. Furthermore, even though the plasma torch is deviated from the right position, appropriate welding can be successfully carried out because the workpiece is the anode in this process and thus all power is supplied to the workpiece.
Metal surface modification by electrical discharge machining with composite electrode
N. Mohri, N. Saito, Y. Tsunekawa   / N. Kinoshita (1)
STC E,  42/1/1993,  P.219
Keywords: Electrical Discharge Machining, Surface Properties, Composites
Abstract : This paper presents a new method of surface modification by electrical discharge machining using composite structured electrode. Surface modifications on work pieces of carbon steel or aluminum were carried out in hydrocarbon oil using composite electrodes. Composite electrode consists of' green compact products or sintered products. Copper, aluminum, tungsten carbide and titanium were used for the material of the electrode. It was revealed that there existed the electrode material in the work surface layer and the characteristics of' the surface of raw material remarkably changed. These surfaces have less cracks, higher corrosion resistance and wear resistance.
On the maximum depth and profile of cut in pulsed Nd : YAG laser machining
C.Y. Jiang, W.S. Lau (1), T.M. Yue  
STC E,  42/1/1993,  P.223
Keywords: Laser Beam Machining, Depth, Dimension
Abstract : The maximum depth in pulsed Nd: YAG Laser machining is one of the critical problems due to the relatively small mean beam power. A theoretical model is established to predict the depth of machining by considering the laser beam intensity distribution and file interaction of the beam with the material. The influence of the focal spot position on the depth of machining is analyzed and experimentally investigated. Moreover, the transverse sectional shape of the machined hole or slot can also be approximately predicted.
Environmentally friendly and high capacity dielectric regeneration for wire EDM
G.N. Levy (1)  
STC E,  42/1/1993,  P.227
Keywords: Wire EDM, Filters, Environmental Impact
Abstract : In wire EDM the most frequently used dielectric is water. During recent years a significant progress in cutting speed has been achieved. This requires an efficient and long term autonomy regeneration system. On the other hand, the environmental impact on machining has become more relevant. Use of water bears some risks. A filtration unit based on membrane technology which fulfills both requirements is described, and experimental results are presented and discussed.
Study of pulse electrochemical machining characteristics
K.P. Rajurkar, J. Kozak, B. Wei   / J.A. McGeough (1)
STC E,  42/1/1993,  P.231
Keywords: Electrochemical Machining, Modelling, Acuracy
Abstract : The Pulse Electrochemical Machining (PECM) promises to improve dimensional accuracy control and to simplify tool design in machining hard, high strength, and heat resistant materials into complex shapes such as turbine blades. This paper presents a mathematical model for the PECM process which takes the non-steady physical phenomena in the gap into consideration, A specially-built PECM cell and a high-speed data acquisition device are used to obtain accurate experimental results for the model verification. The interelectrode gap characteristics, including pulse current, metal removal rate, effective volumetric electrochemical equivalent and electrolyte conductivity variations, are analyzed based on the model and experiments.
Droplet-based manufacturing
J.H. Chun, C.H. Passow   / N.P. Suh (1)
STC E,  42/1/1993,  P.235
Keywords: Deposition, Liquids, Processing
Abstract : Droplet-based manufacturing (DBM) processes are promising production techniques for metallic parts and coatings with unique properties. In DBM processes, molten metal droplets are produced and deposited onto a substrate where they solidify to form near-net-shape parts. The quality of parts formed using such processes depends on the precise control of droplet size, flux, velocity and temperature. This paper presents an experimental study on the effect of droplet impact states and mass flux of the spray on deposit characteristics, using a unique DBM apparatus that generates molten metal droplet sprays with precisely controlled droplet size, mass flux and thermal state.
Ion beam fabrication of ultra-fine patterns on cemented carbide chips with ultra-fine grains
I. Miyamoto, N. Taniguchi (1)  
STC E,  42/1/1993,  P.239
Keywords: Dies, Cemented Carbide, Ion Beam Machining, Patterns, Electron Beam, Masks
Abstract : This paper describes the fabrication of opto-electrical and opto-mechanical devices by transferring ultra-fine patterns on cemented carbide dies into a glass substrate. Photo resist masks made by electron beam lithography were transferred into cemented carbide chips with grain sizes of 2-3 pm and 0.5 um using a Kaufman type ion beam machining apparatus. The cemented carbide chip, with ultra-fine grain of 0.5 um, machined with 1.0 keV argon ions, has fine surface under 4-5 nm in Ra and 12-20 nm in Rz, and the chips may be useful as the substrate for dies. The transferred dies have good pattern profile and photo resist masks also have fairly good etch selectivity for etching by ion beam.
Controlling of Q-switched YAG laser beam machining by generated sound
T. Miyazaki, Y. Tanaka, T. Tokunaga   / N. Taniguchi (1)
STC E,  42/1/1993,  P.243
Keywords: Acoustic Detectors, Control, Laser Beam Machining
Abstract : Q-switched YAG laser beam machining processes are monitored by sensing generated sound. The generated sound pressure varies with the focusing condition of the laser beam, kind of the workpiece material and removal rate. A system for improving the machining capability is newly developed, which can perform the Laser oscillation switching, automatic focusing and refocusing of the beam. In the system, drilling operation can be automatically started and finished. A hole can be drilled to the rear surface of 2 mm thick Si_3 N_4 , plate in 8 s; this plate cannot be drilled through to the near surface without this system.
Micromachining using excimer lasers
H.K. Tönshoff (1), D. Hesse, J. Mommsen  
STC E,  42/1/1993,  P.247
Keywords: Excimer Lasers, Micromachining, Micromechanical Parts
Abstract : Excimer lasers can be used to machine metals, ceramics and polymers, UV radiation with short pulses of several 10 ns and intensities much higher than those of other sources allow machining with minimum thermal influence. The high photon energy of excimer laser radiation facilitates a direct photolytic interaction with the material. Besides this thermal and pyrolytic interaction mechanisms also appear. Considering on this, the removal mechanisms of certain materials are discussed. The application of special features of this micro-machining center are the beam handling system with integrated flexible mask and energy control. The workpiece handling and all process parameters are controlled by a host computer with ergonomic user interface. The unit can be used to generate microstructures in ceramic and polymer surfaces. Furthermore, it is possible to produce micro-mechanical parts of these materials, also in fibre reinforced plastics.
Anode erosion in wire-EDM. A theoretical model
G. Spur (1), J. Schönbeck  
STC E,  42/1/1993,  P.253
Keywords: Process Models, Wire-EDM, Finite Element Method
Abstract : Theoretical predictions concerning the machinability of different materials by EDM are difficult because numerous aspects govern this problem. The influence of the thermo-physical material properties which play a dominant role can be studied best b_y a theoretical model Thus. a new model which s tailored after a typical wire-EDM discharge has been developed and experimentally verified. The model describes the impact of a discharge on the anode as a heat source on a semi-infinite solid whose size and intensity are time-dependent. The numerical analysis of this mathematical problem has been performed by using the Finite element method.
Three dimensional printing : the physics and implication of additive manufacturing
E. Sachs (2), M. Cima, J. Cornie, D. Brancazio, J. Bredt, A. Curodeau, T. Fan, S. Khanuja, A. Lauder  
STC E,  42/1/1993,  P.257
Keywords: Castings, Ceramics, Computer Aided Design (CAD), Metals and Alloys, Toolmaking
Abstract : Three Dimensional Printing is a process for creating parts directly from a computer model. 3D Printing builds parts in layers by spreading a layer of powder and then selectively joining the powder in the layer by ink-jet printing of a hinder material. After all layers are printed, the loose powder is removed to reveal the finished pan. Application areas include ceramic molds for metal castings, directly printed parts for end-use and for use as tooling, ceramic preforms for metal matrix composites, structural ceramic parts and others. 3D Printing is a member of a group of layer manufacturing techniques which have the primary distinguishing feature of creating parts by the controlled addition (rather than subtraction) of material. The primitive building element in 3D Printing is a spherical ensemble of powder particles held together by one droplet of binder. Ballistic effects are important in the formation of primitives due to kinetic energy associated with the incoming droplet_ Stitching together of droplets forms surfaces and hence determines surface finish. Vertical dimensional control is determined in part by the compression of powder layers by subsequently applied powder. These physical mechanisms help to determine the dimensional control and surface finish of 3D Printed parts.

 STC F 

Computer aided simulation of extrusion and/or drawing of fin-tubes and fin-bars
M. Kiuchi (1), S.I. Jima  
STC F,  42/1/1993,  P.261
Keywords: Fin-Tube, Fin-Bar, Extrusion, Drawing, Simulation
Abstract : An analytical method based on the upper hound method has been developed for investigating into deformation features of workpieces in dies for extrusion and/or drawing of fin-tubes and fin-bars which have longitudinally straight radial-fins on their outside or inside surfaces. The general equations which denote velocity fields of workpieces in dies are formulated and the mathematical procedure for overall analysis is established. By this method, power requirement, extrusion pressure, drawing stress, precise geometry of extruded or drawn fin-tube and fin-bar and geometry of die desirable for making fins as high as possible are successfully calculated and predicted. Through a series of analyses, effects of working conditions on shapes and dimensions of manufactured fin-tubes and fin-bars have been consistently clarified. Moreover, knowledges helpful for design of dies and processes have been systematically obtained.
Computer-aided modeling of a new copper extrusion process
T. Reinikainen, A.S. Korhonen (1), K. Andersson, S. Kivivuori  
STC F,  42/1/1993,  P.265
Keywords: Forming, Extrusion, Finite Element Method
Abstract : The general principles in the development of forming processes and processes for the production of semi-finished copper products in particular are briefly discussed. Conform extrusion is chosen as an example of a novel copper extrusion process. Finite modelling of the Conform extrusion is carried out after making simplifying assumptions on the deformation geometry. The distribution of strain, strain rate and temperature is studied by making FEM calculations on a workstation computer.
Central bursting defects in drawing and extrusion numerical and ultra-sonic evaluation
N. Alberti (1), A. Barcellona, A. Masnata, F. Micari (2)  
STC F,  42/1/1993,  P.269
Keywords: Drawing, Numerical Models, Ultrasonic Control
Abstract : A new approach for the prediction of central bursting defects in extrusion and drawing is proposed: a finite element analysis of the processes has been carried out, and the obtained results have been elaborated by means of a post-processor, which, employing a proper ductile fracture criterion, is able to suggest if and where the central burst occur. An ultrasonic control system able to detect the insurgence of defects with a resolution of 0.2 mm. has been setup in order to verify the predictive capability of the model. The experimental results show a good agreement with the numerical predictions confirming the effectiveness of the proposed approach, whose industrial application appears very suitable.
Analysis for the automation of small batch manufacturing using open die forging
B. Aksakal, F.H. Osman, A.N. Bramley (1)  
STC F,  42/1/1993,  P.273
Keywords: Open Die Forging, Upper Bound, Automation
Abstract : Open die forging is a long established process which can be used to produce a wide range of shapes. Its characteristics features in relationship to other types of forging processes are hat it requires low forming loads and only a small range of simple tools to make a wide variety of shapes. Whilst the process is generally associated with the production of large forgings, an automated version could be attractive for small batch manufacturing of low weight forgings. Such a system could compete effectively against machining process. This paper examines the process of pressing small size parts by open die forging, reviews existing literature and presents an upper bound based solution for single step and incremental open die forging. The validity of the theoretical analysis is assessed by comparison with experiments and found to be in a good agreement.
Tool cost estimating at the early stages of cold forging process design
P.F. Bariani (2), G. Berti, L. D'Angelo  
STC F,  42/1/1993,  P.279
Keywords: Tool, Cost Estimating, Cold Forging
Abstract : Identifying the most appropriate sequence of cold forging operations for a new part requires a number of technological and economical evaluations concerning loads, mechanical properties of the forged component, its producibility on the machines as well as costs for equipment and associate tooling. This paper presents a methodology for estimating initial and maintenance costs for cold forging tools. This methodology is for use of planners at the early stages of process design, when the sequence of forging operations and equipment are decided and before details of the tooling system are available.
Optimization of cold rolling of precision tubes
P. Hulm (2), R. Fogelholm, A. Salwen  
STC F,  42/1/1993,  P.283
Keywords: Forming, Cold Rolling, Tubes, Simulation
Abstract : The goal for the optimization of process and material parameters in cold rolling of precisions tubes is a product with accurate dimensions, without eccentricities, possessing eligible final properties. The common practice of such optimization is based on experience and empirical know-how. In this paper is described a systematic approach based on a computer assisted process model combined with an appropriate characterization of the material behaviour in this process. The developed models allow to cut down experimental investigations and trials otherwise necessary for a proper choice of a optimal combination of the process and material parameters.
Design, analysis and experimental verification of the pack rolling process
J.S. Gunasekera (2), A.F. Ali, R. Anbajagane  
STC F,  42/1/1993,  P.287
Keywords: Rolling, Forming, Design, Finite Element Method
Abstract : The paper presents a design and analysis approach for the pack rolling process to determine the stability in terms of the correct dimensions of the material and the desired microstructure without defects. Pack rolling involves the rolling of "difficult-to-form" materials within a pack or cover material. Simulation of the process require, modeling, the physics of the pack rolling process; the temperature distribution, the velocity discontinuities between the cover plate and the workpiece, and the deformation process. An analytical model was developed for simulating the pack rolling process which utilizes a cinematically admissible velocity field to determine tine relative slip between the cover plate and the workpiece, a heat transfer module determines the temperature distribution, and the deformation analysis is modeled by a modified slab method. A 3D finite element analysis with coupled heat transfer for pack rolling is presented. The pack rolling model was correlated with experiments and the more accurate finite element model.
Determination of optimum forming path in three-roll bending by combination of fuzzy reasoning and finite element simulation
K. Osakada (1), G. Yang, K. Mori  
STC F,  42/1/1993,  P.291
Keywords: Roll Bending, Tools, Flexibility, Finite Element Method, Sheet Metal
Abstract : A method for determining the optimum forming paths in the roll-bending process of plates by combining the finite element simulation with the fuzzy reasoning is proposed. In this method, the forming conditions in the finite element simulation are automatically changed to attain the desired shape of the plate with the help of the fuzzy reasoning by monitoring the calculated results such as the curvature of the plate, the stress and strain distributions, etc. in each deformation step. To form the front and the rear ends of a plate into a proper curvature by three-roll bending, it is essential to give an appropriate path of the top roll. For this purpose, the optimum motion of the top roll is successively searched for in the finite element simulation. The fuzzy reasoning is used to determine the motion of the top roll by taking account of the effects of the plate thickness, the flow stress and the difference between the desired and the calculated curvatures. It is shown that the decrease in the curvature near both ends of the bent plate is prevented by the use of the present method.
Roll bending of thin sheet metal parts on press brakes
E. Von Finckenstein , F. Haase, M. Kleiner, G. Reil, R. Schilling, H. Sulaiman  
STC F,  42/1/1993,  P.295
Keywords: Roll Bending, Tools, Flexibility, Finite-Element-Method, Sheet Metal
Abstract : Increasing the flexibility of the sheet metal forming technology is the aim of various research projects. A special tool system for roll bending thin sheet metal parts on conventional press brakes is presented in this article. Furthermore a finite element simulation (FEM) provides more information which is necessary for an additional optimizing of this tool.
The mechanism of laser forming
M. Geiger (2), F. Vollertsen  
STC F,  42/1/1993,  P.301
Keywords: Forming, Laser Beam Application, Simulation
Abstract : Laser forming is a complex dynamic forming process. Its basic feature is the forming by thermal stresses, induced by irradiation of a laser beam. A two-layer model for laser bending is proposed, which is capable to describe the process in spite of many restrictions which have to be made. It is shown that the coefficient of thermal expansion is one of the most significant parameters for the process. The model shows the right dependence on the sheet thickness and the right order of magnitude for the bend angle which can be obtained in one step of the laser bending process. Possible extensions of the model are discussed, using experimental results which had shown that the neutral line lies at a relative thickness z/s_0 =0.65.
Modelling and simulation of the aquadraw deep drawing process
J.C. Gelin (1), P. Delassus  
STC F,  42/1/1993,  P.305
Keywords: Aquadraw Process, Finite Element Method, Flow Control
Abstract : The aquadraw deep drawing operation with an hydraulic counter-pressure where the die cavity is filled of an hydraulic fluid is analyzed taking into account as well as hydraulic flow between the die and the sheet metal as deformation of the sheet material. The analysis developed in the paper focuses on the main parameters that controls the process. An hydraulic study of the pressure in the die cavity and an analysis of the flow between the die cavity and the sheet metal are presented and qualitative results are given that agree experimental ones. The deformation of the sheet metal is analyzed using a finite element approach taking into account the fluid pressure distribution. The results of the numerical simulations in the case of axissymmetric parts are compared with experimental ones obtained on an instrumented aquadraw press and the agreement is good. The results obtained can be used for a better control of the die cavity pressure to optimize the thickness strain in the formed shape for the given process parameters.
Determination of the remaining formability in formed sheet metal parts from grid measurements carried out by computer image processing technique
J. Danckert (2), K. Albrektsen  
STC F,  42/1/1993,  P.309
Keywords: Forming, Sheet Metal, Strains
Abstract : The paper presents a computer based system for 1) The measurement of a grid applied to the surface of the sheet metal part, 2) Analysing the strain distribution and 3) Determination of the remaining formability in the finished sheet metal part taking history into account. A grid is applied to the surface of the undeformed blank. After forming the grid is measured by computer image processing technique. The strains are calculated automatically and can be displayed on the computer screen in various ways e g. as a process signature together with the forming limit curve (FLC) of the material. By selecting a point on the process signature a new FLC is displayed which shows the remaining formability of the material corresponding to the selected point. By measuring the grid at different stages during the forming, the influence from the strain history on the remaining formability can be taken into account. Examples of the use of the system are given.
Small lot stamping production by progressive unit dies
T. Nakagawa (1), S. Futamura, T. Murata  
STC F,  42/1/1993,  P.313
Keywords: Blanking, Hydraulic Presses, Progressive dies
Abstract : This paper describes a new concept in tooling system and the press machine for the widely used progressive stamping technology. The usual conventional progressive die set up is divided into a number of unit dies performing individual operations. All these unit dies in the system have been standardized. These dies can be fabricated simply by Wire-EDM. Consequently, this system is highly suited to small lot stamping production because the cost of tool making is low and the delivery is quick.
CNC Hydraulic multipoint blankholder system for sheet metal forming presses
K. Siegert   / E. Doege (1)
STC F,  42/1/1993,  P.319
Keywords: Sheet Fed Presses, Hydraulic Equipment, Computer Numerical Control (CNC)
Abstract : Starting with the insufficient pneumatic drawing mechanism (cushion) in the table of single-action presses, a programmable hydraulic drawing mechanism is introduced, which makes it possible to control the sheet metal flow through a controllable blankholder (binder) pressure and therefore represents a major contribution in reproducible sheet metal forming processes.
On the formability of aluminum-coated steel sheet
K.J. Weinmann (2), S.K. Kernosky  
STC F,  42/1/1993,  P.323
Keywords: Sheet Metal, Formability, Coatings
Abstract : Mild steel sheet coated with aluminum was characterized in terms of mechanical behavior and formability. The layer of aluminum, 7 ?m - 10µm thick, was deposited by a relatively recently developed version of physical vapor deposition (PVD). The uniqueness of this particular deposition process comes from the use of a steered arc. The substrate chosen for the study was deep drawing quality steel of the type used in the automotive industry. Tension tests provided information on ductility, strain, and strength. A forming limit diagram (FLD) was constructed and angular stretch bend tests carried out to assess the formability of coated sheet. This study found a 40%37;, increase in the yield stress of coated material over uncoated material. Additionally, coated material has lower formability than uncoated sheet. The majority of the properties of the coated sheet are attributable to strain aging of the steel (diffusion of carbon atoms to dislocations) brought about by the coating process.
Ductile failure in upsetting of a rapid solidification processed aluminium-alloy
F.A.C.M. Habraken, J.H. Dautzenberg (2)  
STC F,  42/1/1993,  P.327
Keywords: Ductility, Upsetting, Aluminium Alloys
Abstract : Cold upset-tests have been performed on a Rapid Solidification Processed (RSP) aluminum-alloy, produced by the 'melt-spun ribbons'-process out of 70%37; car-scrap and 30%37; primary scrap. The ribbons are hot extruded, resulting in 29 mm diameter bar. Its properties regarding plastic flow and fracture are strongly anisotropic. Upset-tests are performed on this alloy to verify a concept for the prediction of ductile failure. The experimental results also demonstrate the mechanical integrity of this material. Hill's flow-criterion for anisotropic materials is used in FEM-models of the experiments. Results of various experiments concerning failure at the equatorial free surface are compared with fracture strains in torsion and tension tests in circumferential direction. Furthermore a surface-instability analysis based on an energy principle is applied. It is shown that a graph of effective strain versus triaxiality (?_m / ?) in addition to an instability-criterion, is a useful tool for the prediction of ductile failure in forming processes.
A study of the plane strain compression test
M. Pietrzyk, J.G. Lenard (1), G.M. Dalton  
STC F,  42/1/1993,  P.331
Keywords: Rolling, Compression, Temperature
Abstract : The applicability of the plane strain compression test to simulate the flat rolling process is examined, analytically and through experiments. The resistance to deformation and the rise of temperature of a 6061-T6 aluminum alloy is determined in plane strain compression. A thermal-mechanical finite element model, developed to analyze both the rolling and compression processes is then introduced. Its ability to calculate the distributions of the variables is substantiated by comparing the time-temperature profiles measured during plane strain compression tests with those predicted by the model. Following next are comparisons of the distributions of stress, strain rate and temperature in the two processes, leading to the conclusion that, in general, good similarity among the parameters is observed and that the plane strain compression test gives a reasonable simulation of the flat rolling process, provided the shape factors are comparable.
The evaluation of flow stress and friction in upsetting of rings and cylinders
A. Bugini, G. Maccarini, C. Giardini, R. Pacagnella   / R. Levi (1)
STC F,  42/1/1993,  P.335
Keywords: Forming, Upstetting, Friction
Abstract : FEM calibration chart for ring upsetting at room temperature is drawn when dealing with annealed Aluminum specimens of different height. The method allows the evaluation of the friction coefficient affecting the plastic flow when teflon films are interposed between dies and specimens.
Springback reduction in draw bending process of sheet metals
D. Schmoeckel (1), M. Beth  
STC F,  42/1/1993,  P.339
Keywords: Sheet Metal, Springback, Draw Bending
Abstract : A model test has been developed in order to examine the springback of sheet metals in draw bending under combined tensile stresses. The tensile stress components are of decisive influence concerning the springback behavior. Therefore, a control of springback is possible with specially adapted blankholder pressure. Experimental results are discussed and compared with results of FE simulation.
Investigation of microstructure and thermomechanical history in the hammer forging of an incoloy 901 disk
G. Shen, R. Shivpuri, S.L. Semiatin, J. Y. Lee   / T. Altan (1)
STC F,  42/1/1993,  P.343
Keywords: Simulation, Hammer Forging, Nickel Alloys, Microstructure
Abstract : A method for computer simulation of hammer forging is presented. The relationship between the observed final gain size in Incoloy 901 disk forgings and the thermomechanical histories obtained from computer simulations was established. It is shown that hammer forging can be modeled with reasonable accuracy by computer simulation and, the calculated thermomechanical history of material along with known phase relations can reasonably explain the evolution of microstructure in forged parts.
Factors affecting the double cup extrusion test for evaluation of friction in cold and warm forging
M.I. Ghobrial, J.Y. Lee, T. Altan (1), N. Bay (2), B.G. Hansen  
STC F,  42/1/1993,  P.347
Keywords: FEM Simulation, Double Cup Extrusion, Friction Test
Abstract : The objective of this study is to expand the double cup extrusion test, used for evaluating lubrication in cold forging, to determine the friction factor m and study factors affecting the sensitivity of this test at the same time. An FEM analysis was used to predict metal flow and forming load for different reductions in area, using a fixed billet geometry. Based on this study a procedure is suggested to estimate friction at large effective strains and interface pressures that occure in cold and warm forging, and factors affecting the results of this test are identified.
New lubricating method for warm forging of steel with boron oxide (B203)
F. Nonoyama, K. Kitamura, A. Danno   / K. Osakada (1)
STC F,  42/1/1993,  P.353
Keywords: Forging, Lubrication, Hot Forming
Abstract : Boron oxide (B_2 0_3 ) is a glass with low viscosity in the temperature range of warm forging. Lubrication properties of B_2 0_3 in warm forging of steels were mainly examined using the backward can extrusion test. On the inside surface of a can. a B_2 0_3 film formed on the surface of a billet contributed to reduce seizure. friction and heat damage of a punch. For the application of B_2 0_3 , to warm forging, however, it was required to reduce friction at low temperatures and optimize the amount of B_2 0_3 , as well as heating conditions. A practical method not only for satisfying these requirements but also for obtaining high lubrication properties of B_2 0_3 has been developed. This method was successfully applied to the production of cans with rectangular cross sections made of high strength steel.
Experimental analysis of cut welding in aluminium
P. Dorph, L. De Chiffre (2), N. Bay (2)  
STC F,  42/1/1993,  P.357
Keywords: Solid State Welding, Aluminium, Strength
Abstract : Cut welding is a newly developed cold pressure welding process. In the present work, an experimental investigation was carried out analyzing the mechanisms involved in cut welding of a block to a strip. Experiments were carried out in technically pure aluminum. The investigation has involved tensile testing and metallographic investigations of the welds. The results show that this variant of cut welding is a very reproducible process giving a weld strength equal to 30-40%37; the strength of the parent material. The experiments have shown that the reason for this relatively low strength is an uneven pressure distribution along the weld due to a wave formed during sliding. Attempts to alter the material flow during sliding are presented.
A constitutive model for friction in forming
L. Anand (2), W. Tong  
STC F,  42/1/1993,  P.361
Keywords: Friction, Forming
Abstract : A new adhering-slipping constitutive model for interface friction is outlined. The model is fully three-dimensional in nature, but rate independent, isothermal and isotropic in character. A new compression-torsion friction experiment to directly measure tool-workpiece interface frictional response under conditions approaching those encountered in quasistatic deformation processing is described. Specific functional forms for the constitutive equations are proposed, and methods to evaluate the material parameters in the interface constitutive model are developed. The particular workpiece-tool pair for which the material parameters are reported in this paper is annealed OFHC copper sliding against AISI A2 tool steel. Although idealized, the model should he useful for a first-order accounting of frictional behavior at dry, unlubricated contacting interfaces in quasistatic deformation processing operations of metallic workpieces with rigid tools.

 STC G 

High-performance surface grinding
E. Brinksmeier (2), E. Minke  
STC G,  42/1/1993,  P.367
Keywords: Grinding, Grinding Fluids, Cutting Speed
Abstract : The availability of newly designed grinding machines wish high stiffness. high spindle power and wheel speeds, super abrasive CBN-grinding wheels, adaptive dressing techniques, coolant delivery, coolant filter, and wheel surface cleaning systems enables application of the high-performance grinding method. This grinding technique, using CBN-grinding wheels. can be characterized by high cutting speeds. relatively high material removal rates, and good surface finish. This paper presents the consideration of chip thickness and its influence on the grinding process, due to the grinding parameters. such as cutting speed. depth of cut and work speed. Results obtained in practical investigations concerning the impact of the coolant delivery, on the emerged forces and on die power demand at high peripheral wheel speeds are discussed.
CBN or CD grinding of profiles
E. Westkämper   / H.K. Tönshoff (1)
STC G,  42/1/1993,  P.371
Keywords: Cubic boron nitride (CBN), Dressing, Technology assessment
Abstract : In practice, profiles in difficult-to-machine materials are ground by means of CD grinding or by using CBN wheels. Both processes permit manufacturing at high cutting speeds and produce a high shape accuracy and a high surface quality. In CBN grinding, this is achieved through the use of vivified bonded or electroplated CBN wheels. The comparatively low wear of this wheel type allows constant operating conditions even at high speeds. In CD grinding, conventional grinding wheels are kept in almost constant condition through continuous conditioning. However, conditioning reduces the wheel volume to a larger extent than the normal grinding wear would do. In this paper, the two grinding processes are compared as to their economical efficiency based on a specific machining task. In numerous tests, first, the technological limits of performance were investigated. On the basis of the test results, a time and cost comparison was made. It was found for CD grinding that an optimization of the process parameters led to better results. With a comparable surface quality, higher material removal rates were achieved. On the contrary, the more expensive CBN wheels did not possess a sufficient pore volume to be able to produce comparable results.
A new grinding method ceramics using a biaxially vibrated non-rotational ultrasonic tool
K. Suzuki, T. Uematsu, H. Tochinai, S. Mishiro   / T. Nakagawa (1)
STC G,  42/1/1993,  P.375
Keywords: Grinding, Ceramics, Ultrasonics
Abstract : A new method for grinding ceramics and hard materials by using a non-rotational tool has been developed. In the method a fixed abrasive type grinding tool is vibrated by a complex ultrasonic transducer longitudinally and torsionally at the same time. Experiments showed that the complex ultrasonic vibration keeps grinding force low and stable for a long time in grinding hard ceramics even without rotating the tool. When a diamond grinding tool with a square or triangular bottom is used, this method has a great effect on producing cavities with sharp inner corners of almost zero radius on various hard-to-machine materials.
Intelligent data base for grinding operations
T. Sakakura, T. Inasaki (1)  
STC G,  42/1/1993,  P.379
Keywords: Grinding, Dressing, Data Base
Abstract : This paper describes an intelligent data base system which performs an intelligent task like a skilled operator. The system consists of a grinding data base, a grinding rule base, a learning module and a reasoning module. The learning module extracts relationships between set-up parameters and results from grinding examples stored in the grinding data base using genetic algorithms. These relationships are expressed in the Form of a fuzzy production rule and stored in the grinding rule hase. The reasoning module provides suitable dressing and grinding parameters using those rules. A computer simulation is performed to confirm the effectiveness of the proposed system.
Computer simulation for cylindrical plunge grinding
N. Chiu, S. Malkin (1)  
STC G,  42/1/1993,  P.383
Keywords: Grinding, Computerized Simulation
Abstract : A computerized simulation is described tot cylindrical plunge grinding operations. The simulation predicts both the grinding behavior during the cycle and the final part quality, including grinding forces, power, actual material removal, temperature, thermal damage, thermal expansion, wheel wear, surface roughness and roundness. White not necessarily predicting the exact performance, the simulation does capture the main effects which occur during the grinding cycle. The conceptual and physical construction of the simulation program are described. Examples are presented to illustrate how the simulation works. Experimental results are found to compare favorably with predictions from the simulation.
Computer visual simulation on structural changes of steel in grinding process and experimental verification
H. Eda, E. Ohmura, S. Yamauchi   / I. Inasaki (1)
STC G,  42/1/1993,  P.389
Keywords: Grinding, Computerized Simulation, Microstructure
Abstract : A computer simulation system was developed to estimate the heat-affected zone (HAZ) of carbon steel in surface grinding process. HAZ is usually generated by solid state phase transformation causes by the grinding temperature. In the present system, the heat flow and phase transformation during grinding process was analyzed using a finite-difference method. The changes with the time of temperature distribution, the carbon redistribution in austenite and the quenching to martensite were simulated or, an engineering work station (EWS). The simulated results of the distributions of temperature, microstructure and carbon concentration were shown in the pseudocolor images on the display. Furthermore, experimental surface grinding was carried out and the results were in good agreement with the simulated results.
An intelligent monitoring system for cylindrical grinding
P. Lezanski,J. Rafalowicz   / J. Jedrzejewski (1)
STC G,  42/1/1993,  P.393
Keywords: Cylindrical Grinding, Process Monitoring, Data Processing
Abstract : A sensor based system for process state monitoring during cylindrical grinding is described. A modular and hierarchical structure with a multiple-sensor approach (cutting forces, vibration, acoustic emission, and both diameter and out-of-roundness of the workpiece) for process monitoring has been proposed for the system. Features are extracted from the sensor readings by signal processing. They form a set of data which makes it possible to evaluate the grinding process in every respect because the signals represent different groups of process features. The problems associate with the signal processing rind recording are discussed.
Abrasive texturing and bursnishing process monitoring using acoustic emission
D.A. Dornfeld (2), J.J.B. Liu  
STC G,  42/1/1993,  P.397
Keywords: Acoustic Emission, Burnishing, Process Monitoring
Abstract : This paper evaluates the use of acoustic emission (AE) feedback as a method to monitor and control the tape burnishing process. A brief review of the research on friction and wear studies using AE, which provides the basis for this investigation, is first presented. A fluid coupled AE sensor is used to monitor the extent of texturing in a thin film rigid magnetic storage disk manufacturing process. Normal and friction forces are also measured for comparison to the AE. A strong correlation was found between characteristics of the disk texture (surface profile and roughness) and parameters of the AE signal (RMS voltage, mean frequency, zero crossing rate and spectral density.) The feasibility of using AE for tape burnishing monitoring is established.
In-process measurements of progressive variation of grinding characteristics in constant-load heavy grinding
T. Natsuo (1), M. Touge, K. Iwasaki  
STC G,  42/1/1993,  P.401
Keywords: Grinding, Material Removal, Self-Sharpening
Abstract : Constant-load heavy grinding was performed on 304 stainless steel with three different alumina wheel types. The variation of grinding characteristics such as removal rate and tangential force with the progress of grinding, has been studied using in-process measuring methods. It was obvious that removal rate, wheel rate and tangential force changed remarkable with grinding tome, and there are closed correlations each other. Wear flat area of abrasive grains were also measured. The variations of grinding characteristics have been explained well with the progressive wear and the generation of self-sharpening.
Measurement of grinding temperature of active grains using infrared radiation pyrometer with optical fiber
T. Ueda, H. Tanaka, A. Torii, T. Sugita   / T. Matsuo (1)
STC G,  42/1/1993,  P.405
Keywords: Grinding, Temperatures, Measurements
Abstract : The temperature of the cutting grains on the grinding wheel just after cutting is measured using a new type of infrared radiation pyrometer with optical fiber and InAs cell. The mean temperature of cutting grains is hardly influenced by the wheel depth of cut or the workpiece speed, but decreases with increase of the wheel speed. The maximum temperature of cutting grains at the cutting point is approximate to the melting point of the work material of steel. The change in the working conditions of cutting grains after every revolution of the wheel is observed.
The effect of deformation on the contact area in grinding
W.B. Rowe (1)  
STC G,  42/1/1993,  P.409
Keywords: Grinding, Modelling, Contact
Abstract : Grinding efficiency and workpiece surface integrity are greatly affected by deflections that occur within the grinding contact zone. This paper is concerned with the effect deflections have on the real length of contact. A new relationship for the contact between the grinding wheel and the surface of the workpiece is introduced based on contact mechanics. The real contact length between the grinding wheel and the workpiece has been modeled based on the theory for cylinders in contact including the effect of the surface roughness of the contact faces. A .second formulation is presented which takes account of the contact area at the micro level of the grains. The new model more accurately describes the mechanics of grinding contact than previous contact models. Application of the new model to published experimental data for plunge surface grinding operations explains why measured contact length can be 50%37; - 200%37; greater than the geometric contact length.
On improved bonding of TiC coated CBN grits in nickel based matrix
A.K. Chattopadhyay, H.E. Hintermann (1)  
STC G,  42/1/1993,  P.413
Keywords: Grinding, CBN, Bonding
Abstract : The present work has shown that galvanically bonded CBN abrasive tools, particularly those with monocrystalline CBN particles having relatively smooth surface may suffer from large grit pull out during grinding. This investigation has further revealed that strong and durable Ni-Cr alloys, which are known to braze uncoated diamond grits very effectively, providing superior bond than galvanic one, however, failed to wet uncoated CBN crystals during brazing. Thus, in order to activate Ni-Cr alloys, surface modification of CBN grits was found to be essential. To achieve this, a new process has been developed, wherein the CBN particles were coated with a strongly adherent film of TiC by conventional CVD. Such surface modification significantly improved retention of CBN grits in Ni-based matrix.
Ultra-precision grinding of optical glasses to produce super-smoots surfaces
Y. Namba, M. Abe   / A. Kobayashi (1)
STC G,  42/1/1993,  P.417
Keywords: Ultra-Precision Machining, Diamond Wheels, Optical Surfaces
Abstract : The typical 11 kinds of optical glasses have been ground by the ultra-precision surface grinder having a glass-ceramic spindle of extremely-low thermal expansion with various cup-typed resinoid-bonded diamond wheels of #200-#3000 in grain size. All kinds of glasses can be ground in the ductile mode and the surface does not contain a micro-crack under the surface. The surface roughness is related with grain size, feed per wheel revolution and glass material, not with depth of cut. Super-smooth surfaces less than 0.2nm rms, 2nm Rmax have been obtained by the ultra-precision grinding.
Proposal of new lapping method for ceramic balls
S. Ichikawa, H. Ona, I. Yoshimoto   / A. Kobayashi (1)
STC G,  42/1/1993,  P.421
Keywords: Lapping, Ceramics, Spheres
Abstract : This paper treats the relation among lapping pressure, wear-distance-ratio, mesh number of abrasive sheet and sphericity of balls in the lapping circumstances off ceramic ball, and the mew lapping method for ceramic balls are presented. Obtained results are as follows: (1) For balls formed by CIP the optimum lapping conditions such as lapping pressure, the mesh number of abrasive sheet and others are found. (2) New lapping method for sintered ball based on the three-point measuring method of roundness measuring method is proposed, and the sphericity of balls can be considerably improved by this method. (3) The optimum share ration of normal loads in combined tools is found for the rapid improvement of the sphericity of balls.
The new method of free form surface honing
B. Nowicki   / M. Szafarczyk (1)
STC G,  42/1/1993,  P.425
Keywords: Honing, Sculptured Surface
Abstract : The finishing of free-form surface such as press forming dies, propellers, screw propellers is usually a manual job or is done by robots equipped with special machining heads The author has elaborated the non-conventional method of honing which enables to place the profiling and the finishing one the same machine tool. The abrasive tools have 4 degrees of freedom, they are elastically pressed against the surface Their working surfaces are always tangent to the machined surface The elaborated method is suitable for machining parts of various plasticity. The minimum allowable curvature radii of the machined parts is 40 mm, the removal rate is about 1 dm²/min and the surface roughness after machining is Ra=0 05-1.5 mm.

 STC M 

Design and modelling of a modular robot system
P.C. Mulders (2), G.J. Kreffer, W.H.M. Bax, A.C.H. Van Der Wolf (1)  
STC M,  42/1/1993,  P.429
Keywords: Mechatronics, Simulation, Computer Adaptive Control
Abstract : A modular robot system - consisting of a linear and a rotary actuator and for loads up to 50 kg - has been developed. The linear robot arm is driven by a DC motor, has a length of 1 m. a maximum velocity of 1 m/s, an acceleration of 5 m/s², and an accuracy of 0.01 mm. The rotational module is also driven by a DC motor with an angular velocity of P/'2 rad/s, an acceleration of P /2 rad/s^² and an accuracy of 10^-5 rad. With a 3D-force sensor teach - and replay of trajectories will be performed. Optimal trajectory control strategies - like e.g. the optimal control law by matrix riccati, the computed torque or model reference adaptive control (MRAC) method - are based on a good knowledge of the system. So from this modular robot an extended dynamic model has been made, which is verified by modal analysis techniques. Next a model reduction has been done - to obtain a simulation model or a control model - and this is necessary to test adaptive path control algorithms with respect to the phenomena of parameter variations during trajectory performance.
SHIVA a multi-arms machine tool
O. Garro, p. Martin (2), M. Véron (1)  
STC M,  42/1/1993,  P.433
Keywords: Machine Tool, Design, Optimization
Abstract : In this article we present a new model of machine toot with higher performance in terms of productivity and flexibility. The prototype of this machine toot is called SHIVA because of its great number of axes and operative parts. We define a methodology of design for these machines based on the use of manufacturing features. Finally we present a comparison between this machine and the classical ones.
Evaluation of a lathe with ferrocement bed
M. Rahman (2), M.A. Mansur  
STC M,  42/1/1993,  P.437
Keywords: Machine Tools, Ferrocement Bed, Centre Lathe, Cutting Tests, Performance Evaluation, Vibration Tests
Abstract : In an earlier study, the feasibility of using ferrocement as a replacement to cast iron in the manufacture of machine tool structures was investigated by fabricating a prototype ferrocement bed for a centre lathe and testing the bed alone. Improved performance exhibited by the ferrocement bed in comparison with the parent cast iron bed under both static and dynamic loadings has inspired the authors to pursue the work and assess the bed in terms of the performance of the machine as a whole. A centre lathe was chosen for this purpose. The traditional cast iron bed in the machine was replaced by a ferrocement bed, designed and fabricated for accommodating all the necessary parts and attachments. The method of fabrication and installation of the bed are described in this paper. Identical vibration and cutting tests were performed in the original as well as the modified machines. Test results indicate that the machine with ferrocement bed provides significantly higher damping and natural frequencies, specially the torsional frequency, and results in an approximately 40%37; deeper cut than the original lathe before the onset of chatter.
Research on machine tools rolling slideways assembly with damping oil-films
Q.Y. Wang, Z. Jiang, W.M. Qian, H.S. Qi   / H.W. Zheng (1)
STC M,  42/1/1993,  P.441
Keywords: Machine Tools, Damping Oil-Films, Rolling Slideways
Abstract : This paper presents an investigation on inserting damping oi1-films into machine tools rolling slideways. It indicates that the vibration-proof ability of the system can be improved significantly by this means as well as its proper moving sensitivity and low-speed moving stability are preserved. The experimental formula of the damping coefficient of rectangular oil-films with a parallel gap is presented through tests. The rolling slideways system with damping oil-films is modeled in accordance with the special characteristic of the structure and the corresponding identification method of the damping coefficient is presented. Furthermore, computer simulative experiments are carried out. On the basis of the analysis of the results the objective for optimization of oil-film damping parameters is given.
Spindle bearing systems for high speed applications in machine tools
M. Weck (1), A. Koch  
STC M,  42/1/1993,  P.445
Keywords: Spindles, Lubrication, Roller Bearings
Abstract : The operational speed of spindle bearing systems with angular contact ball bearings is limited amongst other factors by the highest permissible rotatory speed of the bearings The revolution parameter limit of these bearings currently lies at about n*dm=1.5*10^6 mm/min if lubricated by the principle of minimum oil quantity. This paper will introduce how, by applying oil-air minimum quantity lubrication using a new oil-air supply, the revolutionary parameter limit was able to be increased to approximately n*dm=1.8*10s mm/min. On the basis of test results it shows how the application of ceramic balls or coated bearing elements reduces the surface wear under insufficient lubrication conditions and increases the life span of the bearing.
Open system controllers, a challenge for the future of the machine tool industry
G. Pritschow (1), C. Daniel, G. Junghans, W. Sperling  
STC M,  42/1/1993,  P.449
Keywords: Machine Tools, NC Controllers, Open System Architecture
Abstract : This contribution deals with the present situation of the European machine tool industry and the control manufacturers as well, as with the motivation to start with the design of a vendor-neutral open control system. The problems of configuration and control-internal communication are discussed and solutions are given. Furthermore, the ESPRIT project OSACA is presented which aims at the specification of vendor-neutral standards for open control systems.
Polynomial predictive functional control (PPFC) for motor drives
P. Boucher (2), D. Dumur (2), H.P. Kurzweil  
STC M,  42/1/1993,  P.453
Keywords: Machine Tools, CNC, Control System
Abstract : Among the field of predictive technics, Predictive Functional Control seems to be very attractive for non specialists of predictive control methods, due to its simple tuning, and well adapted to C.N.C. machines. This different approach is presented here in a polynomial form called Polynomial Predictive Functional Control (P.P.F.C.) to provide a stability analysis and a simple design of the tuning parameters. The developed version improves classical solutions by including a control weighting factor to avoid high values of the control signal. The new P.P.F.C. is finally used for the velocity control of motor drives and experiments stress the advantages of this method in terms of simple design and robustness, compared to previous results obtained with Generalized Predictive Control.
Collision free five axis milling of twisted ruled surface
F. H. Rehsteiner, H.J. Renker (1)  
STC M,  42/1/1993,  P.457
Keywords: Cutting Path, Milling, Surfaces, Geometry
Abstract : Ruled surfaces (generated by straight ruling lines) are a special kind of free form surfaces which plays an important role, e.g., in aerodynamic surfaces (rotary engines). They are particularly well suited for five axis milling by the flank milling method. In the case of twisted ruled surfaces, however, the obvious milling method of having the cutter touch these ruling lines along a generator of its own flank leads to collision problems, The nature of these twisted ruled surfaces is analysed and conditions for their collision free milling by a cylindrical cutter are established. Efficient milling strategies are found.
Efficient simulation programs for chatter in milling
S. Smith, J. Tlusty (1)  
STC M,  42/1/1993,  P.463
Keywords: Milling, Chatter
Abstract : This paper outlines the use of PTP (peak-to-peak) diagrams for the evaluation of the results of multiple runs of a time-domain simulation of a milling process. These diagrams summarize the amplitudes of the forces, deflections, or surface finishes resulting from a large number of simulations through a range of axial depths of cut and spindle speed. The diagrams have similarities to and contain the global information of the familiar stability lobe diagrams, while including the detail available from simulation.
Screw presses with a flywheel inertia variable moment
D. Temeljkovski, p. Popovic   / V. Solaja (1)
STC M,  42/1/1993,  P.467
Keywords: Screw Presses, Conceptual Model, Load Control
Abstract : Starting from the theoretically made complex model of screw presses the authors present a new driving system which is designed in order to provide available energy variations. After mathematical modeling and computer-aided simulation the experimental research is carried out on the laboratory model. The model control is done by microprocessor. The obtained results of the theoretical and experimental research arc a solid foundation for designing screw presses of changed conceptual solutions which will have a higher degree of compatibility of the machine capabilities and the technological processes requirement according to energetic parameters.
Environmentally clean machining processes - A strategic approach
G. Byrne (2), E. Scholta  
STC M,  42/1/1993,  P.471
Keywords: Machining, Environmental Impact
Abstract : Present day machining processes are not clean. Current trends in the manufacturing world indicate that this situation will not be acceptable in the Future and that extensive research and development work is essential in order to meet the future requirements of legislation In this paper, the various possible routes to achieve clean machining processes are analyzed and discussed. It is shown that the conventional approach has its limitations and that a new and innovative approach is essential within the framework of an environmentally oriented management system and the relevant networks for data provision and analysis Processes have to be subjected to fine analysis giving detailed consideration to the various inputs and outputs Combined processes, alternative processes, new technologies, energy requirements etc. have to be evaluated from the environmental perspective A first approach to the strategy required to answer the many questions which arise in relation to clean machining processes and to an integrated environmental protection policy is presented and discussed

 STC O 

Development of a virtual manufacturing system by integrating product models and factory models
M. Onosato, K. Iwata (1)  
STC O,  42/1/1993,  P.475
Keywords: Manufacturing System
Abstract : Virtual manufacturing (VM) is a concept of executing manufacturing processes in computers as well as in the real world. VM makes it possible to estimate manufacturing processes previously without using real facilities, and therefore, VM is expected to be used for many applications in manufacturing. This paper firstly introduces the concept of VM systems and discusses the relations with other concepts in manufacturing. After the discussion about the requirements for VM systems, the architecture of VM systems is explained. Lastly, some systems developed for VM systems are introduced.
Modelling flexible manufacturing systems based on Petri nets
H. Van Brussel (1), Y. Peng, p. Valckenaens  
STC O,  42/1/1993,  P.479
Keywords: Flexible Manufacturing Systems, Modelling
Abstract : Petri nets have evolved into a powerful too: for analysing asynchronous concurrent systems. In this paper the Petri net formalism is used for developing modular models of flexible manufacturing systems (FMS). Coloured-Timed Extended Petri nets are used to model the shared resources, the precedent constraints of the products to be fabricated in the PMS, as well as the automatic transport system of the FMS. A systematic approach to generate the Petri net model for the FMS is proposed and implemented. The resulting Peen net models serve as a simulation tool for scheduling optimization.
A step towards intelligent manufacturing : modelling and monitoring of manufacturing processes through artificial neural networks
L. Monostori   / J. Prohaska (1)
STC O,  42/1/1993,  P.485
Keywords: In-Process Monitoring, Tool Wear, Neural Networks
Abstract : In the paper different approaches are described for applying artificial neural network techniques for modeling and monitoring of machining process (turning, milling) by sensor integration. Back propagations network are used for state classification of tools, estimation of the tool wear and inverse modeling of the cutting process. Special emphasis is placed on the incorporation of the varying cutting conditions into the learning phase and solution, which are based upon normal operation, i.e. cutting with sharp tools. Performances of the developed strategies are demonstrated and compared. At the end of the paper the role and perspectives of artificial neural networks in intelligent manufacturing are highlighted.
A software architecture for FMS simulation and control
A. Del Taglia   / M. Santochi (1)
STC O,  42/1/1993,  P.489
Keywords: FMS, Control, Simulation
Abstract : Control software for an FMS is normally tailored on a specific plant: this causes long development times and high costs; hence the impossibility to have the software at the early stage of the system design and the difficulty of modifying the software during the working phase. The paper describes a software architecture that allows the interactive definition of an FMS model and, at the same tine, automatically builds the control and emulation software. These, together, constitute an off-line detailed simulator that may be used for plant optimization. When the plant is completely set up, the control software is also available; when the plant is functioning, the simulation software may be used as on-line simulator for the decision rules optimization.
Conceptual design of a relational data base for manufacturing processes
S. Kastelic, J. Kopiac, J. Peklenik (1)  
STC O,  42/1/1993,  P.493
Keywords: Relational Data Base, Machinability Data, Optimization
Abstract : An effective CA-process planning and the optimization of conditions depend significantly on the quality and availability of the machinability data for various manufacturing processes. The contribution explains the conceptual design of a relational data base, its structure and the standard procedures for using the data in CAPP, NC-programming and other preparatory operations for production. An illustrative example reveals the viability of the design of the data base and the procedures of optimizing the turning operations.
RALB - A heuristic algorithm for design and balancing of robotic assembly lines
J. Rubinovitz, J. Bukchin   / E. Lenz (1)
STC O,  42/1/1993,  P.497
Keywords: Robotic Assembly, Line Balancing, Frontier Search
Abstract : This paper describes an heuristic approach for design and balancing of a robotic assembly line. The objective of RALB (Robotic Assembly Line Balancing) algorithm is to balance the assembly line, by allocating equal amount of work to the stations on the line, while assigning the most efficient robot type, out of several different types of robots available for the assembly task, to each workstation, and minimizing the number of workstations and robots used. RALB uses heuristics to limit and guide a Branch and Bound frontier search, thus leading to solution of very large or difficult problems. A recommendation of the optimal set of heuristic rules is made based on results of extensive testing of RALB with a variety of assembly problems.
A two-stage approach for optimizing simulation experiments
N.C. Ho, S.S.G. Lee, Y.L. Loh   / A.Y.C. Nee (1)
STC O,  42/1/1993,  P.501
Keywords: Simulation, Optimization
Abstract : Simulation experiments involve many parameters (factors) not all of which significantly affect system performance. This paper proposes the application of Taguchi method prior to optimization, to reduce the number of experiments using orthogonal array design, and to determine the significant factors through sensitivity analysis. Non-linear optimization search strategies are then used to determine the 'optimal' level of these factors. This approach, besides being straightforward, can optimize both quantifiable and non-quantifiable factors and also reduces optimization time. Results from initial studies support its effectiveness in the optimization of simulation systems.
Lower and upper bounds of manufacturing cost in FMS
S. Noto La Diega (2), A. Passannanti, U. La Commare (2)  
STC O,  42/1/1993,  P.505
Keywords: Optimization, FMS,Cost Analysis
Abstract : The use of traditional techniques of product costing, cost control and performance evaluation in advanced manufacturing environment supplies poor results to operations management. In this paper, after a brief review of the major drawbacks traditional machining economics, a new framework for product costing will be presented. The basis of the proposed approach lies on an analysis of the production process aimed at single out proper cost drivers for the use of the various employed manufacturing resources. As a consequence, the quota of the manufacturing cost of uncertain allocation is drastically reduced. A lower and au upper bound value of the unit production cost are also defined with reference to the given manufacturing system. The range between the above bounds is used for accounting the costs of uncertain allocation.
Logistics performance measurement of shop floor activities
H.P. Wiendahl (1), W. Ullmann  
STC O,  42/1/1993,  P.509
Keywords: Production Logistics, Performance Measurement, Monitoring System
Abstract : The way to 'World Class Manufacturing' often suffers from the lack of objective performance criteria on shop floor level. We introduce new approaches for the logistics evaluation of production by means of a specific performance measurement (P.M.): monitoring methods support the analysis of production and order flows and structures, allowing for a quantified turn to account of hidden potentials. On this basis, company-wide accepted information systems with illustrative graphics help to keep on-track with consistant and realistic defined goals.
IPPM - A prototype to integrate process planning and job shop scheduling functions
H.C. Zhang   / E. Merchant (1)
STC O,  42/1/1993,  P.513
Keywords: CAPP, Production Scheduling, Functional Integration
Abstract : Functional integration has taken the foreground in the current manufacturing system development. Process planning and job shop scheduling we two main manufacturing functions involved in shopfloor activities. An integrated process planning model (IPPM) is introduced in this paper. The two functions (process planning and job shop scheduling) are truly integrated by means of distributed approach which is different from current nonlinear and alternative process planning approaches. In this paper, the two functions are integrated at task stage, while the nonlinear and alternative approaches are taken place at result stage which cannot be considered as real integration but rather interface. The introduced IPPM works in three levels, based on manufacturing resource availability and real time feedback from shop floor they are: pre-planning, pairing planning, and final planning. The IPPM consists of three modules, introduced in detailed in the paper, they are: process planning module, production scheduling module, and decision making module. An example is provided to illustrate the model. This paper is to be considered as a contribution to the research efforts in process planning and integrated manufacturing.
Intelligent support mechanisms in adaptable human computer interfaces
D. Spath   / H. Weule (1)
STC O,  42/1/1993,  P.519
Keywords: Computer Systems, Human Factors Engineering, Conceptual model
Abstract : Advanced production technology is not only characterized by higher automation of production flow and control, but more and more measured at the level of the ergonomics of man-machine interaction. Although much effort has been devoted to user friendly design and improved interface techniques, today's systems do not take into account their individual user's problems and tasks. One possible answer to this problem is the design of 'cooperative', adaptable or adaptive user interfaces. The idea proposed is to adapt interface behavior (presentation and dialog control) on account of individual user differences or user problems, by reasoning about user intentions in situational work contexts. This paper presents the theory behind and an approach for design of adaptable/adaptive human-computer interfaces for software applications in the field of production technology, exemplified by a shop floor technology planning tool.
The application of Features in airframe component design and manufacturing
J.H. Kappert, F.J.A.M. Van Houten(2), H.J.J. Kals (1)  
STC O,  42/1/1993,  P.523
Keywords: images/cirpfichiers/annals/ CAD/CAM
Abstract : This paper discusses recent results obtained from the development of a CAD/CAM application, which supports the generation of the manufacturing information for airframe components, which are produced using the rubber pad pressing technique. It describes the design module, which has been developed to generate feature based product models. The feature based approach guides the designer in creating product models according to company rules. These models represent the input for the subsequent modules for manufacturability analysis and tool design. The features are implemented as extensions to the data structure of a commercial geometric modeler. The functionality of the manufacturability and tool design modules are briefly discussed to clarify the demands these modules put on the product model. It is shown how high level design modifications can be supported using die proposed product model.
On the automatic generation of set-ups given a feature-based design representation
F.L.M. Delbressine, R. De Groot, A.C.H. Van Der Wolf (1)  
STC O,  42/1/1993,  P.527
Keywords: Optimisation, Process-Planning, Computer Integrated
Abstract : Manufacturing (CIM) A design methodology has been developed which takes manufacturing restrictions into account in the geometric design phase. This has been accomplished by defiling Manufacturable design transformations. A Manufacturable design transformation is a design operation which has one or more manufacturing operations as counterpart. The applied design operations are recorded in a Design Tree which is an integral part of the product model. Process planning converts this Design Tree, given the available manufacturing machines, fixturing tools and machining tools, into a Manufacturing Tree. The Manufacturing Tree consists of one or more set-ups with per set-up a collection of basic manufacturing operations. This paper deals with the automatic generation of set-ups given a design representation based on Manufacturable design transformations. The main advantage of this approach is a faster generation of set-ups. Furthermore, the generated set-tips and the collection of basic manufacturing operations per set-up can be used for automatic generation of NC code.
Generation of machining scenario and its applications to intelligent machining operations
S. Takata (2)  
STC O,  42/1/1993,  P.531
Keywords: Machining, Simulation, Modeling
Abstract : A machining scenario is a description of a machining process in which the changes of machining states are described in terms of both geometrical and physical characteristics of machining processes such as geometry of tool-workpiece contact face, cutting force, and machining error. A machining scenario can be automatically generated by a model based cutting simulation. It provides useful information for pre-process optimization of cutting conditions, on-line adaptive control, and monitoring and diagnosis of abnormal occurrences. This paper describes the data structure of the machining scenario and how it can be utilized for the generation of efficient and reliable machining data and realizing intelligent machining operation. The results of experiments by a prototype system are also described to verify its effectiveness.
SITS - A semi-intelligent tool selection system for turned components
S. Hinduja, G. Barrow (1)  
STC O,  42/1/1993,  P.535
Keywords: Optimization, Tool Selection, Turning
Abstract : A method of selecting tools for the manufacture of turned components is describes. The system, which is user-friendly, is capable of dealing with all the operations normally associated with the manufacture of turned components. The tools, particularly those for external turning operations, are chosen so that optimum economic performance eg minimum cost is achieved. While the system does include a number of automatic routines and is, in fact, capable of automatically selecting the tools, the user can interact with it and override the system choice. However, if the system is overridden the user is informed of any increase in cost caused by the choice of an alternative tool or tools.
Principles of multidisciplinary cooperation in research
A. Kjellberg   / G. Sohlenius (1)
STC O,  42/1/1993,  P.541
Keywords: Behavioural Science, Manufacturing Technology, Multidisciplinary Cooperation
Abstract : This paper introduces a framework for systematically and strategically using behavioral sciences in order to achieve more far reaching results from long-term, visionary technical R & D work. The framework describes the most important aspects of interdisciplinary work, which are: the "integration components" and the "integration dimensions" for achieving the utmost level of integrated, cooperative work. Reflecting upon 20 years of empirical data it is clear that different levels of integration during the research process will lead to different types of reports with a predetermined quality - as to the achieved multidisciplinary integration. Furthermore, the successive specification of the framework and its application - "the total integration principle", developed for long-term R&D work - resulted in a research tradition change.
An opportunistic approach to process planning within a concurrent engineering environment
A. Herman, M. Lawley, S.C.Y. Lu (2), D. Mattox  
STC O,  42/1/1993,  P.545
Keywords: CAPP, Concurrent Engineering, Life Cycle
Abstract : Traditionally, design and manufacturing activities have been serially linked by the process planning function. One objective of concurrent engineering is to transform this sequential approach into a more interactive, parallel process. To support concurrent engineering, computer-aided process planning (CAPP) systems must be developed that support an opportunistic style of process planning. This paper presents XTURN, a CAPP system implemented within the IDEEA environment that supports a flexible and opportunistic style of process planning. XTURN enables engineers to explore alternative process plans in early design stages. The engineer controls process selection strategies, while XTURN determines the interactions between the various choices, flags those that are inconsistent, and offers advice on resolving any inconsistencies. XTURN does not require that an inconsistency be immediately removed, rather it remembers the inconsistency and allows the engineer to continue exploration. This paper describes the development and application of XTURN and IDEEA. Also, ongoing research that extends IDEEA into a fully distributed system integration workbench to support concurrent engineering is discussed.
Development of an intelligent machining center incorporating active compensation for thermal distortion
Y. Hatamura, T. Nagao (2), M. Mitsuishi, K.I. Kato, S. Taguchi, T. Okumura, G. Nakagawa, H. Sugishit  
STC O,  42/1/1993,  P.549
Keywords: Machining Centers, Deformation, Neural Networks
Abstract : An intelligent machining center that employs thermal actuators to actively compensate for thermal deformation has been designed, constructed and tested. The machining, center also incorporates an intelligent controller, force and deformation sensors and fail-safe mechanisms to protect against catastrophic failure of the system. Both matrix control techniques and neural network approaches to the control of the thermal deformation of the machine structure have been tested. In both cases, the measured maximum thermal deformation was controlled to a level of 10 micrometers, approximately 1/3 the level of the uncontrolled machine.
Automation of polishing process for a cavity surface on dies and molds by using an expert system
K. Saito (2), T. Miyoshi, T.Sasaki  
STC O,  42/1/1993,  P.553
Keywords: Expert Systems, Dies, Polishing
Abstract : In order to establish an automatic manufacturing system for dies and molds, a surface finishing technology for free form surface must primarily be developed, because the cavity surface is still finished by handiwork of a skill machinist. In this paper, the knowledge of skilled machinists for mold polishing operation was acquired, and an expert system to design the polishing process was established. This system was confirmed to be useful for schedule and determination of the polishing process, and it was verified that performance of this system was similar to expert performance of mold machinist.
Development of computer aided inspection system with CMM for integrated mold manufacturing
H.J. Pahk, Y.H. Kim, Y.S. Hong, S.G. Kim (2)  
STC O,  42/1/1993,  P.557
Keywords: CMM, Molds, CIM
Abstract : An interactive and integrated inspection system has been developed for molds having sculptured surfaces with some basic features, such as: holes, slots and bosses. Features to be inspected can be chosen in the CAD environment. Then the inspection planning is to be done for each feature, respectively. For the accurate measurement of sculptured surfaces, the distribution of measurement points can be controlled to be uniform, curvature dependent or hybrid of the two. The output of the planning is the machine code for a specific CMM having CNC capability. The measured data are to be transferred back to the CAD system, compensated by the form error calculation, and the evaluated errors are displayed graphically. High degree of CAD/CAM/CAI integration is demonstrated by implementing the developed system to real molds.
Representation of process planning knowledge for part families
M. Mäntylä   / G. Sohlenius (1)
STC O,  42/1/1993,  P.561
Keywords: Computer Automated Process Planning (CAPP), Knowledge Based Systems, Group Technology
Abstract : The paper describes the representation of process planning knowledge utilized in a process planner under development at the Helsinki University of Technology. The planner puts special emphasis on the representation and processing of group technological part families. Part families are represented on the basis of a feature model which is associated with a family-specific plan specification encoded in a block structured definition language. The plan specification can be evaluated at planning time to yield a process plan. The evaluation process encapsulates the search amongst predefined alternatives and the required consideration of part instance-specific knowledge. The work is considered a contribution to computer-aided process planning methodology.
Computer-aided tool material selection for metal cutting operations
R.G. Fenton (1), M.F.J. Gagnon  
STC O,  42/1/1993,  P.565
Keywords: Optimization, Cutting-Tool Material, Process Planning
Abstract : A computer based methodology is presented for cutting-tool material selection, using numerical optimization for solving the multi-objective optimization problem. For each cutting-tool material, the feasible set of optimal solutions are determined and plotted, using computer graphics, in criteria space (unit production time vs. unit cost). The best solution for each available tool material is then selected, and the best overall tool material, corresponding to the optimal criteria values, together with the optimal cutting parameters, are determined.
Process oriented organisation of order processing : a new method to meet customers demands
W. Eversheim (1), St. Krumm, Th. Heuser, St. Müller  
STC O,  42/1/1993,  P.569
Keywords: Process Identification, Process Model, Order Processing
Abstract : Today's world is continuously changing. High quality and flexibility as well as low production costs are still important, but these demands nowadays have to be extended by organizational aspects. However, a process oriented organization of customer-led order processing from order receiving to shipping can be seen as a key factor for the future. Therefore, it is necessary to gain a process model of activities (processes) to be done in a company. In this case a model has been developed at WZL, which can be used to build up order processing, to identify organizational problems, and to simulate lead times. Additionally work is done in order to use this model for order planning and control and to build up new process oriented cost accounting methods.

 STC P 

An advanced metrology system
W.T. Estler, Y.H. Queen   / J. Bryan (1)
STC P,  42/1/1993,  P.573
Keywords: Metrology, Angular Measurements, Calibration
Abstract : We describe the new Advanced Automated Master Angle Calibration System (AAMACS) at the U.S, National Institute of Standards and Technology. The heart of this system is a set of three stacked concentric indexing tables with 832, 729, and 625 teeth respectively. The system is fully error corrected and achieves a full-circle positioning accuracy of = 0.02 arc-seconds with an angular positioning resolution of 0,0034 arc-seconds. System accuracy is limited by autocollimator noise. We will describe the error mapping process and the use of the system for high-accuracy autocollimator calibrations.
Compensation for errors introduced by non-zero fringe densities in phase measuring interferometers
C.J. Evans   / J. Bryan (1)
STC P,  42/1/1993,  P.577
Keywords: Interferometers, Optical Measurement, Optical Surfaces
Abstract : Interferometers offer rapid full aperture measurement of optics. Flats, spheres and conics can be measured to high accuracy with computer controlled systems using high density detectors. In principle, aspheres that depart from the base sphere or conic by several micrometers could also be measured. This paper demonstrates that substantial errors may be incurred and describes simple tests to evaluate the scale of those errors. The paper then discusses the error sources and presents a method for compensating for those errors.
An accurate interference refractometer based on a permanent vacuum chamber
M. Renkens, P.H.J. Schellekens (2)  
STC P,  42/1/1993,  P.581
Keywords: Interference Refractometer, Laser Interferometry, Refractive Index
Abstract : A new accurate interference refractometer, without pumping device, has been developed. The refractometer is based on a commercially available laser measurement system and uses a prismatic measuring cell, containing a permanent vacuum chamber. Measurements of the refractive index of air can be carried out accurately, easily and quickly with this instrument. l'or this instrument also a new arrangement of a double pass, plane mirror interferometer with high stability was developed. The accuracy of the interference refractometer is analytically and experimentally determined and appeared to be better as 1 part in 10^7 .
Non-Contact probe for continuous measurement of surface inclination and position using dynamic irradiation of light beam
K. Yamazaki (2), H. Aoyama, K.S. Lee, M. Sawabe  
STC P,  42/1/1993,  P.585
Keywords: Dimensional Measurement, Optical Measuring Instruments, Scanning
Abstract : The paper deals with a development of a new non-contact probe module for the high speed measurement of dimensions of a product. The probe module can continuously and simultaneously detect a position and a surface normal vector with custom signal processing algorithm developed. A probe module using multiple optical fibers was designed and a simulation was performed for verifying the proposed idea. A probe module was also prototyped and tested. Successful results were obtained and its performance coincided with the simulation. For practical application, a multi-beam dynamic irradiation probe using the developed module was designed and prototyped.
Vibroscanning method for mondestructive measurement of small holes
T. Masuzawa (2), Y. Hamasaki, M. Fujino  
STC P,  42/1/1993,  P.589
Keywords: Micromachining, Measuring Instruments
Abstract : A new method for measuring inner dimensions of small holes was developed. The electrical contact between a vibrating feeler and the inner surface of a hole is detected, and the duty cycle of the contact is measured. Through a controlled scan by a feeler with a constant duty cycle, data on the ups and downs of the surface profile are obtained. Through the application of this principle, a Ø 200 ?m hole with the depth of 700 ?rn was successfully measured, and geometrical data such as straightness, declination and taper were obtained.
Four point method of roundness and spindle error measurements
G.X. Zhang (1), R.K. Wang  
STC P,  42/1/1993,  P.593
Keywords: Precision, Measurements, Roundness
Abstract : A new method of roundness and spindle error motion measurement is presented in this paper. Roundness error of the workpiece and radial error motion of the spindle are measured simultaneously by using 4 probes mounted with certain angle arrangement. This method gives high accuracy for all harmonics which is difficult for three point method. Based on error analysis a methodology for selecting optimal parameters is given. Both computer simulation and experiment justify the high accuracy of proposed method.
Six axis of sensitivity force sensor for robots
G. Ricciardi (2), L. Borsati  
STC P,  42/1/1993,  P.597
Keywords: Robot Assembly, Laser Beam Welding
Abstract : The paper will present a force/moment sensor for robot advanced applications (e.g. intelligent assembly, finishing, etc). The main features are the very high linearity and repeatability, the very simple procedure of calibration and the low cost of realization. This is due to an innovative conception of geometry, design and technology (laser welding). The paper describes designing and realization techniques including the problems relating to the laser welding of the two pieces that form the sensor and presents the design specifications.
A six degrees of freedom fine motion mask stage for X-ray aligner
N. Kikuiri, N. Uchida, O. Kuwabara   / H. Makino (1)
STC P,  42/1/1993,  P.603
Keywords: Precision, Nanotechnology, Alignment
Abstract : A fine motion mechanism has been developed for an x-ray aligner. The mechanism to align a mask and a wafer precisely has to move with a nanometer-order resolution for several hundred micrometers, which is impossible to achieve with piezoelectric actuators. The mechanism is driven by servomotors, and their displacements are reduced by wedges and ball screws. To obtain high resolution, these transmission parts are designed not to have hysteresis. A better than 20 nm resolution in feedback control with an encoder and a better than 2.5 nm resolution in feedback control using a capacitance micrometer have been achieved.
Magnetic bearing stage for photolithography
M.E. Williams, D.L. Trumper, R. Hocken (1)  
STC P,  42/1/1993,  P.607
Keywords: Mechatronics, Precision, Methodology
Abstract : This paper describes a linear magnetic nearing stage which controls a suspended object in six degrees of freedom. The intended applications is for X-Y wafer positioning in photolithography stages. Magnetic bearings offer superior performance and resolution over existing mechanical X-Y stages. An advanced prototype magnetic bearing stage that improves the ideas verified in the existing stage has been designed and is currently under consideration. The paper will also present the advanced stage design methodology used and the reasons for the decisions made.
Generation of sculptured surfaces by means of an ultra-precision milling machine
Y. Takeuchi (2), K. Ato, S. Kawakita, K. Sawada, T. Sata (1)  
STC P,  42/1/1993,  P.611
Keywords: Ultra-Precision, Milling Machine, Sculptured Surface
Abstract : The study deals with the development of an ultraprecision milling machine, which allows the production of workpieces with sculptured surfaces. Until now, a variety of precision parts have been produced by ultra-precision diamond turning machines. However, they can not cope with making sculptured surfaces, which have higher requirements. The ultra-precision milling machine developed consists of an air spindle with a milling tool and a three-axis feed mechanism. As a milling tool, a pseudo ball-endmill is designed by slightly offsetting a conventional diamond tool having a nose radius. It is found that the ultra-precision milling machine can produce workpieces with sculptured surface in surface roughness of 70 nm Rmax.
From unambiguousty defined geometry to the perfect quality control loop
A. Wirtz (1), C. Gächter, D. Wipf  
STC P,  42/1/1993,  P.615
Keywords: Precision, Metrology, NC-Programming
Abstract : At the CIRP General Assembly 1986 Vectorial Tolerancing, a model for a quality control loop with a real three dimensional correction was presented [4]. In the fifties we learned how to control an automatic lathe by statistical quality control We were successful, because there are only one dimensional features [1]. In this case the calculated deviations could be used directly as a correcting value. In the milling process each feature of a geometric element, like the position and the direction requires up to two correcting procedures. Now such a quality control loop has been successfully built. On the basis of vectorial defined workpiece geometry and the machine kinematics, the NC data for a five axis milling machine and a co-ordinate measuring machine is being produced. After manufacturing the workpiece, the actual geometry is measured, and from it the correction values are calculated. The regulation of the workpiece geometry results from the feedback of the correction values into the planning process.
Comparison of combinatorial rules for machine error budgets
Y.L. Shen, N.A. Duffie (2)  
STC P,  42/1/1993,  P.619
Keywords: Accuracy, Errors, Budgeting, Uncertainty, Design, Machine Tools, Coordinate Measuring Machines (CMM)
Abstract : An error budget is an analysis tool for the prediction and control of the total error of a machine system for which accuracy is an important measurement of performance. The error budget concept is commonly applied in designing precision machine tools and precision measuring machines and requires application of a combinatorial rule to assess total error which is contributed to by a number of individual error components. No single generally agreed upon combinational rule exists for predicting maximum total error that may result from many error components, and precision machine designers often apply empirical formula rules that have evolved from practical experience. Combinatorial rules based on the central limit theorem (CLT) in probability theory and the uncertainty interval concept are described in this paper and compared to two empirical formula rules using two precision machine error source examples reported in the literature. It is shown using Monte Carlo simulations that the CLT combinatorial rules and the empirical formulas adequately predict maximum total errors. However, the CLT rules provide a more rigorous methodology than an empirical formula for predicting total error. Moreover, a confidence level associated with the estimated total errors can be specified for error budgeting in precision machine design.

 STC S 

Photothermal sensing techniques for measuring material properties and near-surface defects
G. Goch, B. Schmitz, M. Reick   / R. Hocken (1)
STC S,  42/1/1993,  P.623
Keywords: Surface Properties, Coatings, Defects
Abstract : Photothermal measurement techniques, particularly the optical beam deflection (Mirage effect) and the photothermal radiometry, are able to determine optical and thermal properties of bulk materials, surfaces and coatings in a non-contact and non-destructive manner. Special interest is focused on the non-destructive parameter evaluation of coatings, of disturbed zones and surface layers after manufacturing processes (e.g. grinding, hardening) and on material inspections (e.g. Vickers test). This paper presents a few recent results of the photothermal beam deflection technique to characterize the optical and thermal properties of bulk solids, of surfaces and subsurface hidden structures. The use of the photothermal technique to determine the thickness of coatings will be illustrated exemplarily. The thermal diffusivity, which influences decisively the heat transfer in non-stationary processes (e.g. cutting,), was measured on non-transparent bulk materials. Furthermore, a model for the change of material properties after manufacturing steps and testing procedures was investigated. A short comprehensive survey of both theoretical and experimental aspects of the photothermal effect for microscopic imaging and related phenomena will be given.
Material characterization of a machined surface using an anisotropic acoustic Lens
T. Semba, Y. Tani, H. Sato (1)  
STC S,  42/1/1993,  P.627
Keywords: Surfaces, Acoustic Microscopes, Nondestructive Tests
Abstract : Metallurgical orientation generated by plastic sliding on the cutting edge produces material anisotropy in both the cutting direction, and the feeding direction on a machined surface. This paper reports on experimental research conducted to evaluate the material anisotropy on a machined surface by means of a scanning acoustic microscope. A point-focus anisotropic lens that can be used for observing an acoustic image and evaluating an acoustic material signature was developed. Then, material characterization on the end milled surface was carried out. It was revealed that the Rayleigh wave velocity, measured while rotating the anisotropic lens, showed a periodical change having peak values in the cutting direction and the feeding direction. At the same time, it became clear that the degree of material anisotropy, the angle of metallurgical orientation and the mean Young's modulus could he evaluated separately through analysis of the measured Rayleigh vane velocity.
A study of chip surface characteristics during the machining of steel
V.C. Ventakesh (1), D.Q. Zhou, D.T. Quinto, W. Xue  
STC S,  42/1/1993,  P.631
Keywords: Surface Properties, Coating, Oxides
Abstract : Carbide inserts of different geometry (SMG, CNMG, CNMG-MG, CPMP, and SPMP) with a variety of coatings CVD TiN, PVD TiN, CVD (TiCN/TiC/A1_2 0_3 ), CVD (TiCN/TiC) + PVD TiN, CVD TiC, and TiN/ A1_2 0_3 ,..TiCN] were used to machine AISI 1018 steel at different speeds with and without a coolant. Three typical colors deep blue, blue, and golden brown were analyzed and found to contain varying amounts of oxide layers consisting of FeO, Fe_2 0_3 , and Fe_3 0_4 . Chip roots from turning/drilling operations were studied for secondary shear/built-up edge formation, and temperatures calculated and related to chip color. Chip color classification, brightness, surface roughness, waviness, roundness, and chip strain were measured and evaluated.
Characterization of surface texture generated by plateau honing process
M.C. Malburg, J. Raja   / D.J. Whitehouse (1)
STC S,  42/1/1993,  P.637
Keywords: Surfaces, Honing
Abstract : The plateau honing operation is being widely used for finishing of cylinder liners for internal combustion engines. Plateau honing has been shown to significantly reduce the costly running-in period due to the fact that very little further modification of the texture is required once the liner is put into operation. In order to better understand, control, and ultimately "engineer" plateau honed surfaces, a comprehensive means of characterizing this texture is required. In this paper the techniques currently used are briefly reviewed and an alternate approach is proposed. The proposed approach is based on analyzing the cumulative distribution plot on a normal probability graph.
Manufacture to function - in optics
D.J. Whitehouse (1)  
STC S,  42/1/1993,  P.641
Keywords: Surfaces, Optics
Abstract : Surface texture can be used to monitor the manufacturing process. The surface of a component is also important in determine how well the component performs. Ideally, the manufacturing process should be picked to ensure that the part work satisfactorily. In this paper, as an example, the specific function of gloss is chosen as a requirement. It is shown what sort of surface is most suitable for this, and how this surface should be made, thereby completing the chain from manufacture to function.
Nano-topography of ultra-precise ground surface of fine ceramics using atomic force microscope
Y. Tchida, K. Kishi   / H. Sato (1)
STC S,  42/1/1993,  P.647
Keywords: Grinding, Ultra-Precision, Ceramics
Abstract : The nanometer scale imaging of ultra-precise around surface of Si_3 N_4 ceramics has been conducted with an atomic force microscope. An ultra-precise surface with a roughness of about 8 nm Rmax could be generated when fine grain diamond wheel with a grain size of #10.000 was used. The topography of the ultra-precise ground surface is affected by the protrusion of grain boundary phase out of Si_3 N_4 crystal surface as well as by the unevenness of grinding streaks. There is an infinite number of surface. These ultra-fine projections have slightly an anisotropic geometry in the shape and in the distribution.