THE INTERNATIONAL ACADEMY FOR PRODUCTION ENGINEERING

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CIRP ANNALS 1992

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 STC A 

Automated sequencing and subassembly detection in assembly planning
G. Dini, M. Santochi (1)  
STC A,  41/1/1992,  P.1
Keywords: Assemblies, Planning, Subassemblies
Abstract : This paper describes a procedure for the selection of the subassemblies and the assembly sequences of a product, applied in an assembly planning software system named FLAPS (FLexible Assembly Planning System), under development at the institute of mechanical technology of the University of Pisa. This procedure is based on a mathematical model of the product, obtained through the definition of 3 matrices: the interference matrix, the contact matrix and the connection matrix. The possible subassemblies are automatically detected by satisfying some mathematical conditions applicable to these matrices. For each subassembly and for the whole product, all the possible assembly sequences are generated, whose number can be successively reduced according to some optimization criteria. At the end, a meaningful example is reported to show the possibilities of the method.
Planning of products assembly and disassembly
L. Laperriere, H.A. ElMaraghy (1)  
STC A,  41/1/1992,  P.5
Keywords: Process Planning, Assembly, Disassembly, Graph Methods, Optimal Plans
Abstract : Previous research in assembly process planning focused on the generation and evaluation of all possible assembly plans for the product under consideration. While this approach ensures completeness, it is inefficient, time consuming and costly. This paper presents the results of our research which aims at improving the efficiency of the assembly planning process and producing optimal assembly and disassembly plans. Geometric feasibility and accessibility constraints are introduced to reduce the size of the directed assembly graph to be searched. Four criteria have been introduced and formalized to optimize the resulting assembly plans. These are: stability, number of reorientations, concurrency of operations, and grouping of similar operations. Graph search methods which guarantee optimality of plans are briefly described. Examples of real products are used to illustrate the generation of: assembly plans, disassembly plans for repair and maintenance, and plans to recover from assembly execution errors.
Integrated assembly planning and scheduling - CAPP related issues
W.H. Elmaraghy   / H.A. ElMaraghy (1)
STC A,  41/1/1992,  P.11
Keywords: Computer Integrated Manufacturing (CIM), Computer Aided Process Planning (CAPP), Production Planning and Control (PPC), Assembly Planning
Abstract : Responsiveness to unforeseen disturbances on the shop floor is highly desirable in order to increase throughput, reduce waste and improve resource utilization and productivity. Such responsiveness requires changes to process planning systems (CAPP) and production planning and control systems (PPC). This paper deals with issues related to CAPP and its integration with PPC. It discusses two modules: a reactive planning environment (RPE) and an event handler communication system called the Integrator, developed at McMaster University and the University of Western Ontario, respectively. Various integration scenarios and their advantages and disadvantages are presented. The developed modules were applied to product assembly planning in combination with operations, from other manufacturing domains, required to complete the product. Complementary research in production planning and control is carried out by IPA (Stuttgart) in a collaborative project.
The integration of CAPP and PPC - The PPC part
H.J. Warnecke (1), H. Kühnle  
STC A,  41/1/1992,  P.15
Keywords: Computer Integrated Manufacturing, Assembly, Scheduling
Abstract : The paper introduces concepts for the integration of Computer Automated Process Planning (CAPP) and Production Planning & Control, PPC). Logics, benefits and scenarios of functional integration are discusses. Methods and techniques for the implementation of integration are highlighted. Based on a general assembly process model, various planning aspects of PPC such as lot-sizing, scheduling and bottleneck management are finally shown.
A knowledge-based system for automated assembly planning
H.K. Tönshoff (1), E. Menzel, H.S. Park  
STC A,  41/1/1992,  P.19
Keywords: Knowledge Based Systems, Assembly Sequence, Layout Planning, Programming of Robots
Abstract : This paper presents a computer-aided planning system for automated assembly cells, which uses the product description to generate assembly sequences and finally robot programs. For solving the entailed problems knowledge-based techniques are applied. In order to determine the assembly sequence, the assembly task has to be described by the jointing positions between the individual parts and by the assembly technology to be applied. The multitude of combinational possibilities for the various connections can be reduced with the help of planning rules. Within the layout planning, the travel route is optimized to achieve the minimum cycle time. On the functional level of automatic programming, the assembly processes are described in terms of their operational functions. On the language level, the individual functions are then translated into commands for the specific machines.
Acoustic test procedures - A powerful method for quality assurance and process monitoring in the assembly
J. Milberg (1), J. Wisbacher  
STC A,  41/1/1992,  P.25
Keywords: Assembly Systems, Acoustic Emission, Quality Assurance
Abstract : In many cases, it is necessary to integrate suitable test methods for process monitoring and quality assurance into automatic assembly systems. Noise analysis is a comprehensive approach to the analysis of the various complex interactions between assembly product and assembly process. This test method is based on the noise pattern characterizing technical processes. If errors occur in the assembly process, the noise pattern usually shows characteristic deviations. These can be determined by comparing the measured noise characteristics to stored reference data. By means of noise analysis, even complex processes can be monitored at poorly accessible positions within an assembly system. Apart from that, this method is highly versatile and flexible, as the application examples "Process Monitoring of the Assembly of Clip Elements" and "Assurance of the Assembly Quality of Three-Phase Generators" show.
Application of advanced data processing technology for integrated inspection in electronics assembly
P. Mengel, N. Roth (2), P. Schwartz  
STC A,  41/1/1992,  P.29
Keywords: Flexible Assembly, Integrated Inspection, Acoustic and 3D-Sensorics, Neural Networks
Abstract : The paper deals with integrated test and quality assurance systems for monitoring and control of advanced production lines in electro technical industry. The focus of the paper is on the application of innovative data processing technologies based on neural networks which are used both for acoustic signal interpretation as well as for image processing. By describing examples of their application in the manufacturing of electro motors and in the assembly of Printed Circuit Boards (PCB) both the technological approach as well as the conclusions from the industrial application are discussed.
Process planning and robotic assembly system design for technical textile fabrics
G. Seliger (2), C. Gutsche, L.H. Hsieh  
STC A,  41/1/1992,  P.33
Keywords: Technical Textile Fabrics, Robotic Assembly, Process Planning and System Design, Lay-Up, Bonding
Abstract : Assembly of non-rigid sheet materials represents one of the most premising but difficult fields in industrial automation. Knowledge about parts interaction during gripping and joining is a prerequisite for process planning and design of automated assembly systems. In this paper part behavior and relevant process parameters are quantified. Experimental determination of the parameters for the design of needle and card grippers as well as for determining of joining strategies for bonding and lay-up of technical textile fabrics is described in detail. Design tools based on process parameters increase the planning efficiency. Design fundamentals for needle and card grippers have been worked out. An example of planning and design for a flexible assembly system based on the experimental results is shown.
A simulation system on assembly accuracy
T. Arai (2), K. Takeuchi  
STC A,  41/1/1992,  P.37
Keywords: Assemblies, Tolerances, Geometric Modeling, Simulation, Selective Assembly
Abstract : In order to construct a high performance manufacturing line in a short time, it is inevitable to simulate manufacturing process from the view point of accuracy. This paper proposes a method of evaluating the accuracy of assembled product based on a geometric model. Machining errors, assembly errors and measuring errors are modeled as probability distribution functions in Monte Carlo method. Selective assembly is simulated, and the number of the classification is evaluated. The result indicates the number of the classes improves the assembly accuracy, but decreases slightly the efficiency of the total assembly line.
Screw fastening in flexible automated assembly with computer-integrated process control
K. Feldmann (2), M. Steber  
STC A,  41/1/1992,  P.41
Keywords: Flexible Assembly, Process Control, Quality Assurance
Abstract : A special challenge in flexible automated assembly systems is still to optimize the screw fastening. Therefore a computer integrated system was developed, which helps to plan and control the screw fastening process. The concept was tested systematically in an assembly cell with a gantry robot, which manipulates a bolting spindle. The developed program can control several bolting processes simultaneously. Furthermore, relevant process data can be recorded and stored. In case of process failures the additional monitoring system supports the supervisor to solve the problems. This special assembly cell is part of a computer-integrated model factory at the University of Erlangen.
A comparison of control paradigms for adhesive dispensing
A.A. West, J.C. Hinde, D.J. Williams (2)  
STC A,  41/1/1992,  P.45
Keywords: Adhesives, Assembly, Controllers
Abstract : This paper compares implementation styles for elements of the solution of a control problem encountered in the manufacture of electronic assemblies. The implementation studies include the application of rule based control within an object oriented environment, a neural network based system equivalent to elements of the rule based process controller and a design study for a control system implemented in a conventional procedural language. The control task is the control of the accurate dispensing of the small quantities of adhesive used to secure surface mount components to mixed technology printed circuit hoards and therefore allow the assemblies to tie wave soldered.

 STC C 

New approaches to characterising the performance of coated cutting tools
W. König (1), R. Fritsch, D. Kammermeier  
STC C,  41/1/1992,  P.49
Keywords: Coatings, Physical Vapor Deposition (PVD), Wear Resistance
Abstract : The paper deals with the properties of PVD and CVD coatings deposited on HSS or cemented carbide tools. Titanium-based ternary layers form the main topic. The substrate and coating properties related to straight and interrupted cutting of quenched and tempered steel are characterized. Differences in performance between coated tools are explained through a separate consideration of substrate and coating influences. In addition, the paper describes a new approach to analyzing the effects of the thermal properties of the "coated tool" composite on the type and progress of wear.
Machinability of particulate aluminium matrix composites
N. Tomac, K. Tonnessen   / F.O. Rasch (1)
STC C,  41/1/1992,  P.55
Keywords: Cutting, Composites, Wear
Abstract : Mechanical and physical properties of light metal matrix composites (MMC) indicate that these materials could play a significant role in applications for engineering components. The aim of this investigation has been to enhance the knowledge about the machinability of a specific particulate aluminum matrix composite (AlSi7Mg) alloy reinforced with 14 vol%37; SiC. The high percentage of hard silicon carbide (2700 HV) which is used to reinforce PAIMC makes machining operations very difficult. The hard SiC particles are forced against the tool, causing excessive abrasive flank wear. The main objects of the investigations were tool wear, cutting forces and surface roughness.
High performance machining of SiC whisker reinforced aluminum composite by self-propelled rotary tools
P. Chen   / T. Hoshi (1)
STC C,  41/1/1992,  P.59
Keywords: Composites, High Speed Machining, Tool Life
Abstract : Aiming to machine a SiC whisker reinforced aluminum composite for the sake of high production rate and high cost efficiency, the self-propelled rotary tool was proposed and evaluated in this study. Experimental results show that the rotary tool made of carbide exhibits superior wear-resistance comparable to the diamond tool, that tool life of carbide has been extended dozens of times by rotary cutting, that the rotary tool bears neither built-up edge nor flank build-up, and that the radial thrust cutting force component of the rotary tool is 30-40%37; lower than that of the fixed circular insert. The rotary tool is found to be a high performance cutting tool for machining of the composite.
Machining of fibre and particle reinforced aluminium
L. Cronjäger (1), D. Meister  
STC C,  41/1/1992,  P.63
Keywords: Drilling, Milling, Composites
Abstract : The machining of metal matrix composites causes problems because the tool wear, due to the hardness of the ceramic Fibers and particles, is extremely high. The use of high speed steel tools (HSS) is not possible. Polycrystalline diamond (PCD) tipped tools are often necessary to guarantee a dimensional stability and an economic machining. To diminish the tool wear the relation of the particle size, the PCD-grain size and the feed rate is important. The application of a coolant or lubricant can effect a higher tool wear. In spite of the extreme tool wear the machining quality is often better than to the case of not reinforced aluminum.
A new approach to the theoretical analysis of surface generation mechanism in machining
G. Byrne (2)  
STC C,  41/1/1992,  P.67
Keywords: Machining, Surface Properties
Abstract : This paper reports on a new theoretical approach and the development of a computer simulation program for the analysis of engagement mechanics and surface generation mechanisms in machining under geometrically defined conditions. Based on the example of external cylindrical turning, a model of the work hardening mechanisms which arise in the surface layer during machining has been developed. This idealized model comprises two sub-models. In the first sub-model the geometrical and kinematic inter-relationships in the zone of cutting are described. The second sub-model describes as a first approach the behavior of the workpiece material during chip removal. Both sub-models form the basis of a computer simulation program which allows the prediction of engagement conditions, micro-hardness level and surface layer damage. From the practical, industrial machining point of view, an understanding of surface generation mechanisms takes on renewed importance in order that environmentally acceptable machining processes can be developed in the future. The work is also of direct relevance to precision and ultra-precision machining.
Comprehensive chip form classification based on the cutting mechanism
K. Nakayama (1), M. Arai  
STC C,  41/1/1992,  P.71
Keywords: Cutting, Cutting Tool Geometry, Chip
Abstract : For the logical control of the chip form in machining operation, chip forms are classified comprehensively, and the conditions to control the form are indicated. Due to the developments in cutting tool and cutting technology, possible ranges of variation in the conditions and the form of chips produced have become very wide. To meet such situation, the chip form diagram presented before by one of the authors is expanded. Essential meanings of the direction of side curling and chip flow angle on the chip form and the proceeding of helical chip are made clear. A projection on tool face plays important role by changing the line of tool-chip separation and, accordingly, the form and proceeding of helical chip.
On the problem of thermoelectric current in metal cutting
K. Uehara (1), M. Sakurai, T. Ikeda  
STC C,  41/1/1992,  P.75
Keywords: Turning, Tool Wear, Insulation
Abstract : The behavior and the effect of thermoelectric current which flows through tool-chip interface in metal cutting has been a obscure problem for a long time. The aim of this paper is to find out the path of thermoelectric current near the cutting edge and to clarify its influence on the tool wear and cutting mechanism. The path of electric current was determined using an analogous technique. It was found that the path is strongly influenced by tool insulation, tool wear, temperature distribution of tool chip-interface and application of external electricity. These findings explain the results of cutting experiment well.
A statistical model for prediction of tool life as a basis for economical optimization of the cutting process
T.E. Carlsson, F. Strand   / B. Lindström (1)
STC C,  41/1/1992,  P.79
Keywords: Adaptive Control, optimization, Tool Wear
Abstract : The paper is dedicated to the implementation of statistical optimization of the cutting process by identification and prediction of the tool condition and lifetime. A statistical model is presented which uses ideas from the theory of reliability and statistical quality control. Since the model is consistent with the Taylor equation, it can easily utilize existing information about relations between cutting data and tool life. A control strategy, which is based on the model, is put forward. Results from experimental tests of the statistical model and of the influence on the wear rate due to feed variations as well as of the performance of the control algorithm are presented.
Development of a deep hole boring tool guided by laser
A. Katsuki, H. Onikura, T. Sajima, T. Akashi   / T. Matsuo (1)
STC C,  41/1/1992,  P.83
Keywords: Boring, Laser Beam Application, Adaptive Control
Abstract : A laser-guided BTA tool has been developed with the purpose of preventing the axial hole deviation in deep hole boring. To examine the performance of this system, two kinds of experiments were carried out using prebored duralumin workpiece. The first experiment was to examine if the tool can be precisely manipulated by computer. The second was to investigate if the tool can follow the target. The target is located in front of the tool and its position changes in the normal plane to the machining axis. The results show that the tool can turn its course to correct hole deviation.
Cutting conditions and work material state identification through acoustic emission methods
R. Teti (2), U. La Commare (2)  
STC C,  41/1/1992,  P.89
Keywords: In-Process Monitoring, Acoustic Emission, Turning
Abstract : This paper examines the problem of in-process monitoring of metal cutting operations carried out on aluminum alloys for aeronautical applications. Turning tests were conducted on annealed and heat treated aluminum alloy bars, using carbide tools. For both work material conditions, different combinations of cutting parameters were used. During cutting tests, acoustic emission (AE) and cutting force sensor data were detected and processed. The comparison between AE responses from the annealed and heat treated aluminum alloys allowed, with the help of force sensor data. to verify the applicability of AE and sensor fusion techniques for in-process and real time identification of work material state.
Acoustic emission feedback for precision deburring
D.A. Dornfeld (2), V. Lisiewicz  
STC C,  41/1/1992,  P.93
Keywords: Acoustic Emission Sensor, Deburring Automation, Feedback Control
Abstract : Deburring operations account for a considerable portion of the cost of machined components and there have been efforts to automate deburring for some time. This has been done with robots carrying deburring tools and sensor feedback for tacking the edge. The deburring and chamfering of precision components is complicated by the fact that the burr may be very small (0.040 mm or less) and conventional sensing techniques for burr following such as measurement of force on the deburring tool are unreliable due to low metal removal rates. Acoustic emission has been under development as a sensing technique for precision deburring feedback. This paper will establish the basis for use of acoustic emission in chamfering and deburring. The results of recent research to develop and evaluate a signal conditioning and control strategy for chamfering and deburring 6061-T6 aluminum will be presented.
Detection of cutting edge breakage in turning
K. Jemielniak   / M. Szafarczyk (1)
STC C,  41/1/1992,  P.97
Keywords: Tool Life, Brittle Fracturing, Detection, Cutting Forces
Abstract : The paper presents e digital detector of the cutting edge chipping or breakage based on the characteristic variation of the cutting force, associated with brittle catastrophic tool failure. The results of tests of the detector operation, during which a laboratory dynamometer and industrial force sensors have been used are also presented.
Influence of high pressure flushing through the rake face of the cutting tool
R. wertheim (1), J. Rotberg, A. Ber (1)  
STC C,  41/1/1992,  P.101
Keywords: Chip, Coolant, Tool Life, Tool Material, Wear
Abstract : The influence of flushing in metal cutting including flow rate, composition and type of coolant, coolant pressure and direct on, is the subject of many investigations. In the current study high pressure flow was used, penetrating through the cutting tool's rake face and reducing the temperatures in the most critical area. During the investigation the pressure was increased up to 25 bar. Mainly grooving operations were investigated, in which chip symmetry simplifies fine analysis. It was found that flow rate and pressure have a significant influence on tool life and wear behavior as well as on the chip shape and the metallurgical structure of the chip itself. The narrowing and curling effect of the chip, improving chip exit from the slot, is viewed as related to temperature reduction. The investigation covered different cutting tool materials and different workpiece compositions. It was found that the phenomenon of built-up edge was minimized, especially when machining stainless steel and similar high alloy materials.
Tooth chipping during band sawing of steel
H. Chandrasekaran (2), H. Thoors, H. Hellbergh, L. Johansson  
STC C,  41/1/1992,  P.107
Keywords: Band Saws, High Speed Steels, Heat Treatment, Stress Analysis, Micro-Chipping
Abstract : The results from a research study on tooth chipping during band sawing of quenched and tempered steel with HSS tipped bi-metal saws, are presented here. Research efforts were directed to develop a convenient reference sawing test to quantify the tooth chipping phenomenon. Subsequently saw tests were carried out to investigate the influence of saw material composition, processing route (powder and conventional), heat treatment and saw teeth stresses (FEM) upon its chipping propensity. The study shows the importance of correct heat treatment from the point of view of teeth toughness as exhibited during sawing. Here conventional and PM HSS variants displayed different sensitivity to heat treatment and chipping, irrespective of comparable hardness or carbide content. Tire presented information could well serve as the basis for the closer study of the micromechanical and material aspects of saw teeth performance in band sawing.
Measurements on the dynamic behaviour of modular milling tools
J.A.W. Hijink, A.C.H. Van Der Wolf (1)  
STC C,  41/1/1992,  P.113
Keywords: Dynamic Tests, Cutting Forces, Milling Cutters
Abstract : To compare newly designed modular tooling-systems, a number of these systems have been used in order to compare the dynamic behavior. The tools were measured dynamically, and three different cutting tests were performed. As a result of these tests a certain correlation between dynamic flexibility and cutting performance could he found.
Molecular dynamics analysis as compared with experimental results of micromachining
S. Shimada, N. Ikawa (1), G. Ohmori, H. Tanaka, J. Uchikoshi  
STC C,  41/1/1992,  P.117
Keywords: Cutting, Micromachining, Computerized Simulation
Abstract : An attempt is presented on the molecular dynamics (MD) analysis of nanometric chip removal process in micro-cutting. Comparison shows a fairly good agreement between the chip morphologies, the cutting forces and the specific energy in both MD simulation and micro-cutting experiments. It is also shown that MD simulation can be applied to the analysis of thermal field in metal cutting process with the introduction of suitable scaling on the gradient in thermal field which is affected by the thermal conductivity of the workmaterial.
Atomic-scale cutting in a computer using crystal models of copper and diamond
T. Inamura, N. Takezawa   / N. Taniguchi (1)
STC C,  41/1/1992,  P.121
Keywords: Simulation, Micromachining, Cutting
Abstract : A method of computer simulation based on a quasi-static computation has been proposed to analyze nanoscale cutting. The results of simulation show that, though the cutting mechanism depends on both the crystalline orientation of the workpiece and the interatomic potential between the tool and workpiece materials, discontinuous change of cutting force as well as impulses in the cutting temperature are commonly observed in all cases. The results obtained by a polycrystal workpiece indicate that the plastic deformation in metal first occurs along grain boundaries and then propagates into each grain.
Fuzzy patten recognition for tool wear monitoring in diamond turning
T.J. Ko, D.W. Cho, J.M. Lee (2)  
STC C,  41/1/1992,  P.125
Keywords: Diamond, Tool Wear, Fuzzy, Pattern Recognition
Abstract : In this paper, to monitor single crystal diamond tool wear in ultraprecision machining process, a fuzzy pattern recognition technique was introduced. Some selected features to partition the cluster of pattern were obtained from time series AR modeling of dynamic cutting force signals. The wear on a diamond tool edge appears to be classifiable into two types, one of which is micro-chipping and the other gradual, both very small quantifies to detect compared to conventional tool wear. In this regard, a fuzzy technique in pattern recognition, which considers the ambiguity in classification as well as the weakness of the cutting force variation, was used for monitoring the diamond tool wear status.
Chip formation mechanism in microcutting of an amorphous metal
K. Ueda (2), K. Manage  
STC C,  41/1/1992,  P.129
Keywords: Cutting, Amorphous Materials, Finite Element Method
Abstract : The chip formation mechanism of an amorphous metal is elucidated by means of in-situ scanning electron microscope observation and Rigid-Plastic Finite Element Method (RPFEM). The chip morphology of the amorphous metal exhibits typical lamellar structure due to periodical formation of the localized shear band. The chip formation process is simulated by the RPFEM with considering adiabatic deformation in the primary shear zone. The simulation results including the lamellar structure formation process, the lamella spacing and the angle of the localized shear band are in good agreement with experiment results. The cutting force and the surface integrity are also discussed.
Application of sintered plastics to a pourous vacuum chuck for diamond turning of aluminum magnetic discs
Y. Tani, T. Ohshima, H. Sato (1)  
STC C,  41/1/1992,  P.133
Keywords: Diamond Turning, Aluminium, Plastics, Waviness, Acceleration
Abstract : Urethane vacuum chucks which are in use for diamond turning of aluminum magnetic discs because of their high friction coefficient and high damping ratio have problems in that swelling by a coolant and the nonuniformity of the supporting rigidity due to the suction grooves deteriorate the form accuracies of workpieces. Thus, a sintered porous chuck made of fluororesin has been developed. The investigation of the mechanical features of the chuck indicated that the chuck was only slightly deformed by vacuum suction and loading and that it had an adequate friction coefficient and adequate bonding strength onto the chuck body for diamond turning. Then, diamond turning of aluminum discs was carried out using a hard aluminum chuck, a urethane soft chuck and two types of fluororesin porous chucks. Consequently, the cutting using a fluororesin chuck achieved better straightness and less acceleration of a turned surface than that using any other chuck.
A study on damaged layer remaining in diamond mirror cut surface
K. Horio, T. Kasai, Y. Ogata, A. Kobayashi (1)  
STC C,  41/1/1992,  P.137
Keywords: Ultra-Precision Machining, Residual Stresses, Diamond Tools
Abstract : Residual stresses which remains in diamond mirror cut surface is discussed. After diamond cutting of very thin aluminum alloy workpiece. measurement of its deflection with repetition of slight elimination by chemical etching of damaged layer have been done. With this technique, we can calculate the magnitude of the residual stresses at any depth from the surface. It was found that the residual stresses is affected by the sharpness of a diamond tool, so the residual stresses becomes large with cutting length. Also magnitude of the residual stresses is different by direction of cutting surface such as along to or perpendicular to cutting.
Ultraprecision ductile cutting of glass by applying ultrasonic vibration
T. Moriwaki (2), E. Shamoto, K. Inoue  
STC C,  41/1/1992,  P.141
Keywords: Brittle-Ductile Transition, Ultra-Precision Machining, Ultrasonics
Abstract : Ultraprecision ductile cutting of glass is realized by applying ultrasonic vibration to a single crystal diamond tool in the cutting direction. It is clarified by grooving experiments that the critical depth of cut for ductile cutting is increased and the surface profile of diamond cutting edge is better transferred to the cut groove as compared to the conventional cutting. The transparent surface of soda-lime glass w4-1 surface roughness of 0.03 mm Rmax is obtained by face turning. The work is considered as a contribution to the ultraprecision machining of brittle materials.
Determination of tool cutting capacity
S. Enache (1), E. Strajescu, I. Tanase, C. Opran  
STC C,  41/1/1992,  P.145
Keywords: Cutting Capacity, Mathematical Model
Abstract : In the work, the mathematical model and the results of the experimental researches performed are shown, in order to establish the partial and global tool cutting capacities. They enable the most adequate tools to be chosen, according to the imposed requirements. At the same time, the best cutting conditions can be chosen depending on the concrete priority requirements, so that both the reasonable tool exploitation and respectively, the attaining of best figures of the imposed parameters and technical-economical indices could be assured. Finally, some results of the experimentally performed researches are presented, in the case of cutting: with metallic carbide tips armed turning tools, with twist drills, having different forms of the active part, and with metallic carbide plates armed and milling cutters. The results obtained, emphasize new methods and ways to increase the tool cutting capacity.
Macro plastic deformation of cutting edge - A method for maximum utilization of cutting tool
E. Kuljanic (1)  
STC C,  41/1/1992,  P.151
Keywords: Plastic Deformation, Sensors, Turning, Tool Wear, Productivity Increase, Surface Roughness
Abstract : This paper investigates the macro plastic deformation of the cutting edge and the material near the cutting edge in rough turning. It was found that the macro plastic deformation takes place approximately three seconds after the start of cutting, when the single point cutting tool is not able to cut properly, the surface roughness of the machined surface increases and vibrations appear. A method for maximum utilization of single point cutting tool and tool selection for rough turning, grooving etc. by using the information about the macro plastic deformation of the cutting edge are proposed. Both the way of measuring the macro plastic deformation and how the macro plastic deformation can be detected by means of feed cutting force is presented. Acoustic emission sensors or sensors systems could be used for detecting the macro plastic deformation of the cutting edge.
Some basic relationships for identification of the machining processes
J. Peklenik (1), A. Jerele  
STC C,  41/1/1992,  P.155
Keywords: On-Line Process Identification, Transfer Function, Propagating Surface Interface
Abstract : Research into the machining processes was since F.W. Taylor very intensive, trying to understand and describe the process as a complex object of control. Its modeling was based predominately on the deterministic approach, and well known laws of classical physics. This contribution reports on some research results, where the process represents a part of the close loop machining systems and is described as a propagating and frictional surface interface. Its identification is based on stochastic inputs and outputs, related to the structure of the material. An attempt is made to develop the process transfer function, determining the gain factors, the process frequency bandwidths and the damping factors in relation to the cutting speeds and structural characteristics of the materials.

 STC Dn 

Development of new methodology for mechanical design by symbolized elements with movement
K. Iwata (1), E. Matsuo, M. Onosato  
STC Dn,  41/1/1992,  P.161
Keywords: Design, Mechanism
Abstract : The concept of "Mechanism Diagram" is introduced in order to realize the quick understanding of mechanism in mechanical design. Mechanism Diagram is constituted by the connection of "symbolized elements with movement ", which are derived by analyzing kinematic relations of mechanical elements in machines. A drawing system for Mechanism Diagram is also developed. The result of experiments by using it shows that Mechanism Diagram can remarkably reduce time for understanding a complicated mechanism.
The product structure - The backbone of CIM
L. Lindberg, E. Agerman (2)  
STC Dn,  41/1/1992,  P.165
Keywords: Design, Data Model, Product Structure
Abstract : In this paper we argue that the product structure should be used as the backbone for the modeling and documentation of the product. First a general architecture of a Technical Information System, TIS, based on Functional Systems is presented. Then three major subsystems of the TIS are identified, and one of these, the Product Structure System is discussed in greater derail. The product structure is shown to be in a sense both complete and stable, thus providing a foundation for a true CIM system. A simple, yet versatile, data model is presented, allowing variants and views of the product to be represented.
The 'constructive deductive' design approach - Application to power transmissions
J.P. Van Griethuysen   / A. Wirtz (1)
STC Dn,  41/1/1992,  P.169
Keywords: Design, Modelling, Bottom-Up Design, CAD
Abstract : The constructive deductive approach is a "bottom-up" optimized design method. The method proposes a sequence of logical constructive rules up to the product solution from the functional specifications. It is easy to automate in an intelligent CAD expert system as it is sequential. A description of this approach will precede an application to demonstrate the first step of this method : the design oriented analysis.
Probabilistic aspects of axiomatics
P. Tatray   / G. Sohlenius (1)
STC Dn,  41/1/1992,  P.173
Keywords: Axiomatics, Quality, Design Theories, Top-Down Design
Abstract : Axiomatics is a design theory that is partly based on probabilistic concepts. It proposes two axioms. The first is dealing with coupling of functions in the design, and the second with simplicity and probability of success. Exploring the probabilistic aspects of it leads to a partial reformulation and reinterpretation of Axiom 2, shows where the limits of its application could lie, and shows an alternative way of defining independency in Axiom 1. We can even prove, that simplest is best, combining full independence according to Axiom and the old and new formulation of Axiom 2. Other measures of complexity than given by Axiom 2^ are also discussed, and some possible further research directions are defined.
Integration of CAD/CAM and production control for sheet metal components manufacturing
S. Tilley   / H. Van Brussel (1)
STC Dn,  41/1/1992,  P.177
Keywords: images/cirpfichiers/annals/ CAD/CAM, Production Planning and Control, Features, Data Bases
Abstract : The paper deals with the computer integrated manufacturing and production of sheet metal components. The system developed, aims at giving a high degree of flexibility in choosing the manufacturing resources. Typically the selection of machines and tools is made at the latest possible moment. The decisions are taken using the latest information from the shop floor. The system contains a central database for storing and exchanging information amongst all modules, using parametrical, technological features for description of parts tools and machines. The monitoring is built into the medium and short term scheduler thus allowing the continuous control of orders.
Concurrent design and process planning of rotational parts
D. Domazet, S. lu (2)   / M. Kalajdzic (1)
STC Dn,  41/1/1992,  P.181
Keywords: Concurrent Engineering, Computer Integrated Manufacturing (CIM)
Abstract : In this paper, a system for concurrent engineering of rotational parts is proposed. The paper describes the first modules which have been developed and perform product design, process planning and manufacturability analysis. A feature-based design system generates the product model with multiple representations, including both symbolic and object-oriented. A Lisp-based frame format allows easy transfer of product data to the process planner, also developed in a Common Lisp environment. Using object-oriented programming techniques, a blackboard architecture, and multiple rule-bases, a process plan can be generated during all design stages. This allows the designer to verify his design from a manufacturing perspective and, if necessary, modify it in the early stages. Manufacturability analysis is based on the generated process plan and actual process data inventory.
Design by using machining operations
M.A.S. Arikan (2), O.H. Totuk  
STC Dn,  41/1/1992,  P.185
Keywords: Design, Milling, Part Programming
Abstract : Since every designed part will be manufactured afterwards, it is important to consider also the manufacturing aspects at the design stage. Machining, which is one of the basic manufacturing processes, is the removal of certain selected areas, in order to obtain a desired shape or finish. Therefore, it can be considered as removing some defined geometric elements from a solid object, wherein geometries of these elements are determined by the individual machining operations. A database comprising the geometric elements related to machining operations is constructed, and parts are formed by subtracting these elements from a simple solid object, like a rectangular prism or a cylinder. The database comprises the geometric elements related to available operations on a 2 1/2 axis CNC milling machine. For design of the part by using this method, an interactive computer program with graphical input and output is developed. The program also has modules for sequencing the machining operations according to a prescribed decision logic, for automatic or manual selection of cutting tools for corresponding operations. for calculation of machining parameters by using empirical relations, for creation and usage of personal databases for cutting tool and machining data, and for preparing the NC program and transmitting it to the milling machine for machining of the part.
A feature-based classification scheme for fixtures
A.Y.C. Nee (1), A. Senthil Kumar, S. Prombanpong, K.Y. Puah  
STC Dn,  41/1/1992,  P.189
Keywords: Jig and Fixtures, Classification, Codes and Coding, Group Technology, Computer-Integrated Manufacturing
Abstract : This paper presents a feature-based classification scheme for fixtures using a 3D solid modeler, a feature extractor and an object-oriented expert system shell. Its intended use lies in variant fixture designs as well as its association with machining operations, machining environment, cutting tools and workpiece features. The operations begin with a solid model where machining features are extracted and grouped into setups based on machining directions and tolerance factors. A knowledge base is used to infer the operations involved and the cutting tools required for a given machining environment. Different classes and sub-classes of fixtures are identified based on setups, operations, and fixturing rules. Instead of using numerical taxonomy, the fixture is coded in feature-based symbolic representations which can be compared easily for its similarity with existing fixtures.
Product design evaluation based on effect of shape errors for part assembly
F. Kimura (2), H. Suzuki, K. Takahashi  
STC Dn,  41/1/1992,  P.193
Keywords: Design Evaluation, Shape Error Analysis, Dynamic Simulation
Abstract : One of the machine design objectives is to maximize the functionality under the constraints of manufacturability. It is desirable for designers to be able to analyze the effect of geometrical errors due to manufacturing processes on the functional behavior of assemblies. We propose a method to evaluate the motion of an assembly of parts with geometrical errors. We make idealization of geometrical errors considering typical machining errors, and solve equations of motion of objects under the gravity and friction force from contact constraints by using Linear Programming Method. The result of calculation is useful for evaluating the effect of shape errors on the accuracy of the motion of assemblies.
Tolerance synthesis to support concurrent engineering
R.G. Wilhelm, S.C.Y. Lu (2)  
STC Dn,  41/1/1992,  P.197
Keywords: Tolerance Synthesis, Concurrent Engineering, Computer-Aided Design
Abstract : Geometric tolerances are critical in many phases of product and process design, linking design goals and manufacturing capabilities. With an appropriate representation, geometric tolerances can provide flexibility in concurrent engineering so that, when complete information about geometry and tolerances is available, several different fabrication strategies can be considered and fairly compared. This paper presents a framework and computer implementation that provides automated methods for geometric tolerance synthesis. This approach directly supports design synthesis since design details can be referred from the tolerance relationships which must hold for particular requirements. Automated analysis of completed designs and design checking is also possible with this approach.
Product modelling and "information integrated" engineering systems
T. Kjellberg (2), H. Schmekel  
STC Dn,  41/1/1992,  P.201
Keywords: Product Modelling, Reference Models, Product Realization, "Information-Integrated" Systems
Abstract : The integration of computer represented engineering concepts together with geometric model concepts will be discussed in order to realize future product modeling systems. It will provide for "information integrated" systems in engineering and more advanced tools for communication to realize concurrent product realization. What then can be achieved will be reasoned upon. Implemented examples and developed reference models will show how product models with engineering terminology and concepts can be represented in the computer.
Knabling use of engineering terminology in product models and user interfaces of CAD/CAM systems
L. Wingard, p. Carleberg, T. Kjellberg (2)   / G. Sohlenius (1)
STC Dn,  41/1/1992,  P.205
Keywords: Features, Product Modelling, Interactive Design Systems
Abstract : This paper presents an approach to introducing engineering terminology in product models and user interfaces of CADCAM systems. It describes how we have utilized forth features and engineering elements in order to represent engineering knowledge more naturally in product models. This gives us a method for realizing user interfaces in which an application specific and user adapted engineering terminology is used. A CADCAM Framework for integration of general software packages into a distributed CADCAM system is also suggested. Finally, some aspects of the suggested approach, collected from a limited test implementation and from discussions with an industrial partner are discussed.
Hypermedia as a design tool with application to design of fluid film journal bearings
W.B. Rowe (1), K. Cheng  
STC Dn,  41/1/1992,  P.209
Keywords: Design, Hypermedia, Artificial Intelligence
Abstract : This paper describes a hypermedia based intelligent system for design with particular reference to fluid film journal bearings. It is considered that this approach has potential for much wider application in design. The .system was developed by integrating hypermedia, artificial intelligence and intelligent database technologies, together with conventional design techniques.
Application of adaptive resonance networks for conceptual design
S.R.T. Kumara (2), S.V. Kamarthi  
STC Dn,  41/1/1992,  P.213
Keywords: Conceptual Design, Group Technology, Neural Networks
Abstract : Conceptual design is the most important and creative phase of the design process which demands the knowledge, intuition, and imagination of a designer. The success of the designer in this phase of design depends upon his ability to recall a family of previous design problems which are similar to the current problem and apply the previously discovered solutions. In this paper the application of Adaptive Resonance Theory networks for the creation of families of design problems, characterized by their functional requirements is examined. A comparison of this method is maid with k-mean clustering algorithms. It is found that the Adaptive Resonance Theory networks provides the means for the dynamic creation of families of design problems which cannot be obtained by using conventional clustering algorithms.
Intelligent CAD of Box-type machine components
X.N. Feng (2), Y.Z. Zhang  
STC Dn,  41/1/1992,  P.217
Keywords: Computer Aided Design, Expert Systems, Design, Drawing
Abstract : The basic principles and methodologies of intelligent CAD for box-type machine components are described in this paper. A special developed three dimensional solid modeling graphic software is used to construct on screen the model of machine component to be designed, and to extract the graphic information for generating two dimensional working drawing of box-type machine, component. The necessary graphic entities which should be dimensioned without any redundancy to define the model of machine component unequivocally are determined. Expert systems are used to decide which sizes should be dimensioned and how to distribute all the sizes to each view and section view in the run dimensional working drawing. The CAD system then is able to generate automatically the corking drawing of box-type machine component qualified for manufacturing. It also be described the key strategies including dimension redundancy analysis, the principles of expert systems used for reasonable distributing and dimensioning of sizes etc.

 STC E 

About the evolution of the wire tool performance in wire EDM
D.F. Dauw (2), L. Albert  
STC E,  41/1/1992,  P.221
Keywords: Wire, Cutting Speed, Accuracy, Roughness, Precision
Abstract : Since the commercial introduction of wire EDM on the market, end 1969 begin 1970, the overall performance of the wire EDM has undergone a tremendous evolution. Six major contributing factors nave been responsible for this important change. One of these, the wire tool electrode has been improving substantially yielding an enormous increase of the overall performance (cutting speed, cutting accuracy, precision, cost etc.). The paper deals with an analysis of the six contributing factors. Attention is given in particular to one of these factors, the wire tool itself. The several types of ware are compared twin their metallurgical aspect. Their physical composition and .relative performance are analyzed and a cost to performance ratio is given for a series of wires considered. As a conclusion, it is shown that the wire tool, a though often considered as an evident EDM accessory has influenced very substantially the EDM wire cutting performance.
Observation of the arc column movement during monopulse discharge in EDM
M. Kunieda, H. Xia, N. Nishiwaki   / N. Kinoshita (1)
STC E,  41/1/1992,  P.227
Keywords: EDM and Discharges
Abstract : This paper describes the results of the detection and observation of arc column movement during monopulse discharge and the movement of the arc column subjected to a transverse magnetic field in the EDM process. It is found that not only the cathode spot but also the anode spot moves at a high speed over the electrode surfaces during a monopulse, and that the moving patterns of the anode and cathode spots are the same. Besides, the area over which/ /the arc column moves becomes broader with the progress of the discharge, which coincides well with observation of the resulting craters.
Investigation on the optimum carbide content and machining condition for wire EDM of zirconia ceramics
T. Matsuo (1), E. Ohshima  
STC E,  41/1/1992,  P.231
Keywords: Wire EDM, Zirconium, Ceramics, Cutting Rate
Abstract : Wire EDM has been performed on conductive zirconias containing 23 to 45 vol%37; NbC or TiC, and thus, the optimum carbide content was clarified. The machining rate and surface roughness for various pulse durations and duty factors were evaluated, and consequently, the optimum machining conditions for the wire EDM were discussed. It is obvious that the maximum machining rate can be obtained with about 28-30 vol%37; NbC or TiC content, and that there exists the optimum duty factor from a standpoint of machning rate. Also, the effect of second cut on the machining rate and surface roughness was investigated.
On the electro-discharge machining of ceramic plasma-sprayed steel plates
A.G. Mamalis (1), N.M. Vaxevanidis, D.I. Pantelis  
STC E,  41/1/1992,  P.235
Keywords: Surface Integrity, EDM, Plasma-Sprayed Ceramics, High Strength Steels
Abstract : The present work is a follow-up of the extensive research on "surface integrity of mechanically and/or thermally worked steel grades" undertaken by the authors and also a first step into an investigation of the possibilities and limitations of successfully applying EDMachining on non metallic materials of great industrial importance such as electroconductive ceramics,/ /ceramic-metal and carbon-fibre reinforced composite. In this paper we report on the application of EDMachining to plasma-sprayed WC-Co coating on HSLA steel substrate. The influence of the intense thermal impact due to EDM upon the main features of the resulted surface is examined in terms of microgeometry/ /and surface topography, microhardness variation and metallurgical changes in the surface and the subsurface layers: their dependence on the main processing parameters is examined and discussed. Comparison is also/ /made with high-strength steel grades EDMachined under the same conditions.
Improved jet flushing for EDM
T. Masuzawa (2), X. Cui, N. Taniguchi  
STC E,  41/1/1992,  P.239
Keywords: EDM
Abstract : Jet flushing is the most popular type of flushing for EDM. However, it is usually applied with the nozzles fixed at positions which are decided on the basis of the operator's experience. In this paper we propose a dynamic jet flushing method with moving nozzles that sweep along the outline of the EDM gap. Experimental results clarify the effectiveness of this method on the precision of machining. A method for calculating the debris distribution in the gap is proposed as well.. The result of calculations successfully displays the debris status with various types of jet flushing, showing the superiority of the sweeping jet method.
Analysis and adaptive control of EDM sinking process using the ignition delay time and fall time as parameter
M. Weck (1), J.M. Dehmer  
STC E,  41/1/1992,  P.243
Keywords: EDM, Adaptive Control, Metal Removal, Electrodes
Abstract : EDM sinking experiments were carried out to determine the pulse type with the best ratio of material removal to electrode wear. The results show, that the material removal is only dependent on the discharge duration while the wear is caused only by undelayed and late ignition discharges. This result and a process analysis using methods of the chaos theory were the basis to develop an adaptive optimization of the gap controller.
Laser microformation of thin film on glass substrate for repair of transparent defects on high density masks
T. Miyauchi, M. Hongo, K. Mitzukoshi, M. Okunaka, T. Kawanabe, Y. Koizumi   / N. Taniguchi (1)
STC E,  41/1/1992,  P.247
Keywords: Laser Beam Application, LSI, Defects, Baking
Abstract : A new technique is developed for repairing transparent defects on high density masks for VLSI. A thin Ag-Ta organometallic film is first spin-coated onto a photomask and baked. Then an Ar laser microspot is applied to a small area on this film. After rinsing the mask with a solvent, an opaque layer remains at the laser-irradiated spot and the rest of the organometallic material is washed away. The opaque film formed locally by laser irradiation is dense enough to prevent light transmission and durable enough to withstand repeated washing with strong alkali and acid solutions.
Surface treatment by laser with high thermal gradients
G. Ricciardi (2), M. Cantello, C. Rivela  
STC E,  41/1/1992,  P.251
Keywords: Laser, Surface Treatment, Mathematical Model
Abstract : A theoretical study of heat interact on of laser radiation has been carried out. This study has supplied a mathematical adimensional model able of describing the thermal field versus time depth in a very general way. The model has been checked with experimental tests or, some ferrous alloys by means of CO_2 laser. Specific tests using very high gradients, got from model, have shows the formation of innovative metallurgical structures.

 STC F 

In situ ultrasonic measurement of the real contact area in bulk metal forming processes
M. Geiger (2), U. Engel, F. Vollertsen  
STC F,  41/1/1992,  P.255
Keywords: Forming, Friction, Interface, Contact Area, Ultrasonics
Abstract : The real contact area (r.c.a.) between tool and workpiece is mainly dependent on local forces and sliding velocities. It is one of the most significant parameters describing the tribological state in forming processes. An experimental technique is described which enables the development of the real contact area to be measured in situ, ie during the forming process. The ultrasonic method is proved to give signals of great reproducibility and of high lateral resolution from which the local values of r.c.a. can be determined by proper calibration. In the first part of the paper a comprehensive view on the state of the art investigating contact problems is given. In the second part the basic principles of the ultrasonic method and its new application are described. In the third and fourth part experimental results are given showing the temporal and local distribution of the r.c.a in upsetting, and further applications of this new technique are discussed, respectively.
Investigation of factors affecting the coefficient of friction and surface properties with a sheet drawing test
A. Azushima, M. Yamamiya   / H. Kudo (1)
STC F,  41/1/1992,  P.259
Keywords: Friction, Surface Properties, Lubrication, Sheet Metal, Drawing
Abstract : The purposes of this study are to examine systematically the effect of tribological factors on the coefficient of friction and surface features of drawn sheet, and to propose a method fir predicting and controlling the surface brightness before sheet drawing. Aluminum sheet drawing experiments are carried out:, by changing the drawing speed and viscosity of lubricant. From the experimental results it is seen that since all the data fall on a single brightness versus calculated entrance oil film thickness curve, the surface brightness however is predictable using the entrance oil film thickness. The coefficient of friction is not significantly dependent on the lubricant viscosity and drawing speed.
Proposal of an evaluating method on lubrication
S. Isogawa, A. Kimura, Y. Tozawa (1)  
STC F,  41/1/1992,  P.263
Keywords: Forging, Lubrication, Evaluation
Abstract : The tribological condition in forging is very severe due to no subsequent supply of lubricant during forming, high contacting pressure between tool and work piece and large surface extension of work piece. A method to evaluate lubricants for forging, which is named spike forging test is proposed in which a similar tribological condition as that in forging is generated. In this test, a cylindrical specimen having a height to diameter ratio of 1.2 is forged with a platen, of which surface is provided with shallow concentric grooves, in an impression die, of which approaching angle is 160°, containing a central tapered cavity with 3°. An analytical simulation for this test shows that the height of the spike formed in the central cavity when the platen reaches to a certain distance from the die surface depends strongly an the frictional resistance at the interface. The spike heights obtained by experiment using several kinds of lubricants have a good correlation with forging loads required and also ejecting loads after forging, and hence these three values may be used for evaluating lubricants, The results on lubrication obtained with the method proposed are in good agreement with that in warm extruding operation of stainless steel can, while the results of/ /the ring compression test don't agree with them.
Properties of cold worked metallic parts
P. Huml (2), M. Bergsing, M. Lindegren  
STC F,  41/1/1992,  P.267
Keywords: Forming, Mechanical Properties
Abstract : The aim of the present paper is to present new results from investigations of material behavior under forming conditions corresponding to the strain path in forming processes characterized by cyclic deformation mode and non proportional loading (cold pilger rolling of tubes, swaging, draw-rolling in roller dies). The influence of strain path on material behavior and final properties has been simulated in uni-, two- and three-directional deformation regimes. The obtained results explain the "unexpected" deformation behavior and make it possible to predict properties of cold worked parts with better accuracy than earlier.
Practical verification of ductile failure curves
W.H. Sillekens, J.H. Dautzenberg (2), S.M. Hoogenboom, J.A.G. Kals (1)  
STC F,  41/1/1992,  P.271
Keywords: Forming, Material Properties, DuctilityThis paper deals with
Abstract : the ductility of workpiece materials in connection with forming. The concept of the failure curve is used as a phenomenological means to describe the ductility in dependence on the state of stress. On the basis of analysis and experiment, two different forming operations are studied in order to evaluate the practical relevance of ductile failure curves. These processes are sheet bending and backward can extrusion. As an illustrative material, recycled aluminum of moderate ductility is used.
Computer aided design of dies to control dimensional quality of extruded shapes
R. Shivpuri, S. Momin   / T. Altan (1)
STC F,  41/1/1992,  P.275
Keywords: Computer, Die, Design, Quality, Extrusion
Abstract : Conventionally, steel shapes are extruded using flat faced shear dies resulting in flow related defects such as curvature and twist. As a result, post-extrusion, straightening and detwisting are needed to obtain acceptable dimensional quality of the product. This paper presents a computer aided design and flow simulation procedure for predicting these geometric defects and reducing them by the modification of the die geometry including entry angles and the die land. This procedure was applied to the extrusion of L-shaped structural shapes and the results verified by controlled experiments on a 17,8 MN extrusion press. Significant improvement, in product quality were achieved. This design for manufacturing approach can be applied to other three dimensional steady state processes such as shape rolling.
Friction-assisted extrusion of thin strips of aluminium composite material from powder metals
T. Nakamura, S. Tanaka, M. Hiraiwa, H. Imaizumi, Y. Tomizawa   / K. Osakada (1)
STC F,  41/1/1992,  P.281
Keywords: Extrusion, Friction, Thin-Strip, Aluminium Composite, Powder Metal
Abstract : A new process of friction-assisted extrusion for producing thin strips was developed. An aluminum foil of about 50mm in thickness could be formed at an extrusion ratio R=200 with a considerably low pressure ration p/2k=1 (p: punch pressure, k: yield shear stress) at room temperature. The extrusion process is applied to powder forming for producing thin strips of aluminum composite materials. Composite aluminum powder miwed with SiC ceramics powder by 0~20 vol%37; is successfully extruded into thin strips at room temperature.
Shape control in CNC rotary swaging machine
K. Osakada (1), Y. Goto, M. Shiraishi, T. Okada  
STC F,  41/1/1992,  P.285
Keywords: Metal Working, Swaging, Finite Element Method
Abstract : To obtain sound products with good shape accuracy in the computer controlled rotary swaging machine, the effects of working conditions and the methods for improving the accuracy after forming process are investigated by experiment and FEM analysis. The rigid-plastic FEM analysis with an assumption of generalized plane strain can be employed for predicting the shape of products. Optimum incremental angle of billet rotation is found to be about 10 degrees when 4 dies are used. It is clarified that slow retreat of dies and finishing blows after forming are effective to suppress the shape distortion.
Mathematical simulation of clad sheet rolling and sandwich sheet rolling
M. Kiuchi (2), K. Shintani, Y.M. Hwang  
STC F,  41/1/1992,  P.289
Keywords: Asymmetrical Rolling, Clad heet Rolling, Sandwich Sheet Rolling, Numerical Simulation, Upper Bound Theorem, Sheet Bonding
Abstract : Mathematical models and simulation techniques for clad sheet rolling and sandwich sheet rolling are developed. They are based on the extended upper bound/ /theorem. A series of numerical simulations of clad and sandwich sheet rolling processes are performed. Through simulations, the flow and deformation feature of each sheet (layer) at roll gap, thickness ratio of each layer in rolled clad or sandwich sheet, rolling force, rolling torque and longitudinal curvature of rolled product are successfully calculated. The calculated results are compared with the experimental measurements and very good agreements between them are found. It becomes clear that the proposed simulation techniques are useful enough for characterizing the clad sheet rolling and/ /the sandwich sheet rolling. They enable us to obtain systematic knowledge for designing desirable rolling schedule and performing stable operation.
Influence of hydrostatic pressure in cold pressure welding
W. Zhang, N. Bay (2)  
STC F,  41/1/1992,  P.293
Keywords: Pressure Welding (cold), Hydrostatic Pressure, Surface Properties
Abstract : Earlier work by Bay has shown the introduction of brittle surface coatings by electrochemical or chemical plating to be useful when roll bonding Al-Al. The coating layers fracture during deformation and decover virgin surfaces which extrude through the cracks and establish contact and metallic bonding to the adjacent surface. This paper presents a systematic study of the influence of hydrostatic pressure on the fracture of various types of surface layers. By cold pressure welding Al-Al, Cu-Cu, AI-alloy-Al-alloy and Fe-Fe in simple upsetting the ductility of different coatings have been studied at four different levels of hydrostatic pressure. The ductility of electrochemical matt Ni is very pressure sensitive, chemical Ni is somewhat less sensitive whereas hard chromium is almost brittle even at large pressures.
Temperature, heat flux and conductivity in bar rolling
J. Jeswiet (2), S. Zou  
STC F,  41/1/1992,  P.299
Keywords: Rolling, Temperature, Heat Flux, Conductance
Abstract : The temperatures in the roll gap in unlubricated cold rolling of aluminum have been measured using a recently designed multipoint temperature sensor. The sensor can measure the billet surface temperature, the roll surface temperature and the internal roll temperature simultaneously. The heat flux and interface thermal conductivity are calculated from the interface temperatures by inverse heat transfer methods. Tests were conducted at two rolling speeds and the influence of speed can be seen. Experimental temperature results, interface heat flux and thermal conductivity are shown for different reductions and at different speeds.
Three-dimensional elastic-plastic FEM analysis on torsion of square-section bars
N. Hatada, K. Ueno, M. Ueda, S. Watanabe   / N. Kinoshita (1)
STC F,  41/1/1992,  P.303
Keywords: Forming, Torsion, Finite Element Method
Abstract : This paper deals with FEM analysis on the torsion of solid bars. Using FEM program MARC, three-dimensional elastic-plastic torsion problem, which have not to date been solved, were analyzed. Thus, the longitudinal strain during twisting is calculated for the first time. The decreasing ratio of axial length becomes smaller with the increase of strain hardening ratio. Furthermore, the decreasing ratio of axial length of the square-section bar was larger than that of the circular-section bar. The same tendency has been observed in precious experiments.
An experimental study of heat transfer in metal forming processes
J.G. Lenard (1), M.E. Davies  
STC F,  41/1/1992,  P.307
Keywords: Metal Working, Heat Transfer
Abstract : The success of predictive modeling of hot forming processes is critically dependent on the correct description of the boundary conditions of the deformation none. As far as the thermal events are concerned, these are most conveniently described in terms of the heat transfer coefficient. The magnitude of that coefficient has been shown to depend on process and material parameters in addition to the presence or absence of scaling and lubrication. The study will critically examine the methods available to measure the coefficient of heat transfer: discuss its effect or, predictive modeling and present experimental results concerning its magnitude in compression and hot rolling.
Pressure control in hydraulic tube forming
D. Schmoeckel (1), C. Hessler, B. Engel  
STC F,  41/1/1992,  P.311
Keywords: Tubes, Hydrostatic Pressure, Pressure Control
Abstract : At THD/PtU a manufacturing technique was developed in order to form tubes under internal hydraulic pressure and axial force. The forming of the bulging tube can be influenced by pressure control. Algorithms can be developed to define pressure depending on the axial force or parameters to that, such as displacement and time. The most important parameters of geometry and load are recorded during the process.
Materials processing issue related to fabrication of high Tc superconductor wire
S.K. Samanta (2), S. Samajdai  
STC F,  41/1/1992,  P.315
Keywords: Formability, Thermomechanical processing, Microcomposite
Abstract : An understanding of the mechanism of thermomechanical processing of /Y Ba_2 // Cu_3 O//_7-6 / /- Ag /superconducting microcomposite is needed from the viewpoint of fabrication processing as well as improvement of superconducting properties of the high /T_s /. materials. The processing technique to obtain mechanically strong and environmentally stable /Y Ba_2 // Cu_3 O//_7-6 / /- Ag /superconducting microcomposite wires is discussed. It is shown that compositional changes do occur near the interface. The effect of addition of small quantities of /Cu_2 O /and /CuO /on/ /the superconducting properties and microstructure is evaluated by electrical measurements and scanning and transmission electron microscopy. These additions play a positive role in the reduction of the width of the compositional variation zone. The results are discussed from the point of view of thermodynamic and kinetic aspects of oxygen diffusion and tetragonal ® orthorhombic transformations.
Effect of rigidity of die and press on blanking accuracy of electronic machine parts
T. Jimma, F. Sekine   / Y. Tozawa (1)
STC F,  41/1/1992,  P.319
Keywords: Blanking, Die-sets, Precision, Press
Abstract : Blanking accuracy is decided by the relative displacement of an upper die to a lower die in the blanking. Deformation of a die-set subjected to an eccentric load in a press is analyzed, and the banding moment M and the lateral force Q acting on the end of each guide post are expressed by the inclination q and the lateral displacement DX of the upper die. In the experiment, a die-set of sub-guide construction is installed on a 1250 kN straight side frame press and 1100 kN C-type frame press, and q and DX are measured under static loading and dynamic loading of 100 spm. The calculated M and Q using the measure q and DX show that the M and Q acting on the guide post ens are smaller on the straight side frame press that on the C-type frame press though the capacities of both presses are almost the same; The analytical method proposed in this paper can be used in the selection of a press suitable to a given die set and a given eccentric load.
Sensors and diagnostic systems in forming machines
E. Doege (1), K.H. Schomaker, T. Brendel  
STC F,  41/1/1992,  P.323
Keywords: Forming, Blanking, Deep-Drawing, Sensors, Process Monitoring, Optical Measurement
Abstract : New optical sensors and standard sensors `or the measurement of tool accuracy, acceleration, force and distance get more important for process automation in forming machines. Together with a diagnostic system based on a process control computer it is possible to analyze the production system in regard to workpiece quality, process, machine and tool. Examples of a diagnostic system for monitoring a high speed blanking press with optoelectronic sensors and a diagnostic system for monitoring the machine process in deep drawing are represented.
Forming of glass fiber fabrics into complex shapes-experimental and computational aspects
P. Boisse, J.C. Gélin (1), H. Sabhi  
STC F,  41/1/1992,  P.327
Keywords: Forming, Glass, Fibers, Finite Elements
Abstract : The flow of resin during the RTM process mainly depends on the properties of the glass fiber preform obtained by drawing. The paper describes constitutive equations for glass fiber fabrics and their application in a 3-D shell finite element program for the simulation of complex shaping processes. The material model proposed is based on the non-linear elastic response of a single fiber and is extended to consider interactions between fibers. The finite element approach lies on 3-D shell elements using a membrane assumption where the strains along each fiber direction are calculated and used in a minimum energy procedure. Experimental results concerning the forming of hemispherical shapes reveal the importance of the shearing effects.
3-D Plotting of finite element sheet metal forming simulation results by laser stereolithography
T. Nakagawa (1), A. Makinouchi  
STC F,  41/1/1992,  P.331
Keywords: Finite Element Method, Sheet Metal, Forming, Stereolithography
Abstract : 3-D Finite Element simulation is becoming one of the important and powerful means to solve the various technical problems encountered in the metal forming operations. But any suitable method to express the 3-D simulation results has not been existed except the computer graphics on CRT display. This paper deals with the new expressing method of 3-D simulation results by using the laser stereolithography which is a kind of 3-D plotter. Two types of sheet metal forming simulation results were converted to solid 3-D shapes and it was confirmed that simulation results were more easily understood and could be used more effectively to solve the technical problems with the aids of laser stereolithography.

 STC G 

New grinding methods for aspheric mirrors with large curvature radii
Z. Zhong   / T. Nakagawa (1)
STC G,  41/1/1992,  P.335
Keywords: Grinding, Aspheric Mirror, Large Curvature Radius, Shape Accuracy, Surface Roughness
Abstract : In this paper some new methods for grinding toroidal mirrors, elliptic and circular cylinder mirrors with large curvature radii are investigated. By using the grinding methods proposed here, we successfully obtain aspheric mirrors made of SiC, with higher precision in shape accuracy and low surface roughness, as R_max = 20 - 40 nm, R_a = 2 ~ 5 nm. The data measured show that the roughness is independent of the direction of measurement. Also, the time consumed in the processes is very short.
Development of a new mechanochemical polishing method with a polishing film for ceramic round bars
K. Suzuki, T. Uematsu, H. Ohashi, K. Kitajima, T. Suga, O. Imanaka   / A. Kobayashi (1)
STC G,  41/1/1992,  P.339
Keywords: Mechanochemical Polishing, Polishing Film, Ceramic Round Bar, Silicon Nitride
Abstract : A new mechanochemical polishing method applicable to structural ceramic round bars has been developed by using a polishing film method. A silicon nitride round bar having 20 mm diameter was successfully polished with a Cr_2 O_3 polishing film with 51 mm width. Surface roughness of the bar was improved from 1.2 mm R_max to 45 nm R_max by polishing it for 60 minutes and from 0.63 mm R_max to 24 nm R_max for 30 minutes. It was found the higher polishing speed, higjer oscillation frequency of the film and I harder urethane contacting roller give higher polishing efficiency and better surface roughness.
Magnetic fluid grinding cell design
T.H.C. Childs (2), H.J. Yoon  
STC G,  41/1/1992,  P.343
Keywords: Ceramics, Polishing, Ferromagnetic Materials
Abstract : Magnetic fluid grinding is a process for the rapid grinding and polishing of ceramic ball bearings. Grinding grits are levitated in a ferrofluid contained above a bed of permanent magnets; and balls to he finished are driven through this medium by a shaft against which they are loaded, also by magnetic forces. This paper describes a theoretical and experimental study of the magnetic forces which exist in the process and discusses design of the magnetic fluid grinding cell in terms of these. Shaft contact loads of the order of Newtons per ball are achievable and grits may be levitated tens of mm above the magnet bed.
Surface structure of Mn-Zn ferrite single crystals ground by an ultra-precision surface grinder with various diamond wheels
T. Namba, Y. Yamada, A. Tsuboi, K. Unno, H. Nakao   / I. Inasaki (1)
STC G,  41/1/1992,  P.347
Keywords: Ultra-Precision Machining, Diamond Wheels, Surfaces
Abstract : Manganese-zinc ferrite single crystals have been around by the ultra-precision surface grinder having a glass-ceramic spindle of extremely-low thermal expansion with various resinoid-bonded diamond wheels of #200-#3000. The ground surface can be classified into three categories, that is, fracture mode, ductile mode and ductile & fracture mode grinding by observing, the surface with a Nomarski interference microscope. There is no micro crack under the surface ground in the ductile mode, The relationship between the surface roughness and grinding conditions has been also clarified. The micro-.surface structure has been also discussed with an STM and AFM measurement.
A neural network approach to the decision making process for grinding operations
M. Sakakura, I. Inasaki (1)  
STC G,  41/1/1992,  P.353
Keywords: Grinding, Dressing, Surface Roughness
Abstract : In this paper, a decision making process model for grinding operations is proposed. It has a multistage structure and consists of different two types of neural network: the Feed-Forward network and the Brain-State-in-a-Box network. As an application example of the model, the relationship between the dressing conditions and the surface roughness of ground components is simulated. The results indicate that the proposed model is capable of learning the stochastic data of surface roughness and recalling the dressing conditions which attains the required surface roughness. The simulated process can he considered to be quite similar to the decision making process of experienced operators.
Enumeration of microorganisms in metalworking fluids using photometric methods
R.W. Coughlin, D. Williams, E. Seveau, R. Veith, T.D. Howes (2)  
STC G,  41/1/1992,  P.357
Keywords: Grinding Fluids, Contaminations, Measurements
Abstract : This paper will discuss two approaches to assaying concentrations of microorganisms in metalworking fluids using light. One approach employs fluorescent dye to stain the DNA within microbial cells suspended in the fluid. The intensity of light emitted by the bound dye is measured to provide an estimate of microbial concentrations. The second approach is based upon a light-producing reaction of ATP, a measure of the energetic state that is essentially constant for all living cells. The rate of light production is proportional to the concentration of ATP arid, therefore, to the concentration of microbial cells; the light emitted is then a measure of the number of cells in a sample of fluid. Both approaches provide reproducible and reliable results. These methods have the potential of providing rapid, on-site measurement of microbial loads and are being explored as alternatives to standard piste count and dip slide methods that require an incubation period of up to two days to achieve results.
Sensitivity analysis and tolerance allocation for micro-planer dill point grinders
K.F. Ehmann (2), S.K. Kang, C. Lin  
STC G,  41/1/1992,  P.361
Keywords: Grinding, Drill Points, Tolerances
Abstract : A sensitivity analysis and tolerance analysis/allocation of the grinding parameters is presented to guide the design of planar micro-drill point grinders. The mapping from the desired micro-planar drill point geometry parameter space to he grinding parameter space of the drill grinder has been established to determine a unique grinding parameter set for the desired planar micro-drill point geometry. By means of the sensitivity analysis (variations of the drill point geometry parameters with respect to the grinding parameters), it is indicated which parameters are the most important and most profoundly affect drill point geometry. To specify the upper and/or lower limits of grinding parameter tolerances, and to assure that the total tolerance of the drill point geometry is maintained throughout the desired range, two methods are presented. Tolerance analysis shows he maximal tolerances of the drill point geometry parameters in terms of the maximal tolerances of the grinding parameters. This method requires the tuning of .he tolerances of the grinding parameters until the tolerance of point geometry are satisfied. As an inverse problem to tolerance analysis, a rational tolerance allocation algorithm is investigated to assign the unknown grinding parameter tolerances from the known maximal allowable tolerances of the drill point geometry.
Study on mechanism of ceramics grinding
K. Kitajima, G.Q. Cai, N. Kumagai, Y. Tanaka, H.W. Zheng (1)  
STC G,  41/1/1992,  P.367
Keywords: Ceramics, Grindability
Abstract : The grindabilities of ceramic materials are evaluated through the measurement of the grinding forces, energy, temperature and wheel wear, and the SEM examination of the ground surface arc the grinding swarf. Comparing with SiC and Si_3 N_4 , the grinding force, energy, temperature and the wheel wear in AI_2 0_3 grinding with the same removal rate are lowest. The ground surface roughness of SiC is better because no any bulge formed on the side edges of streaks. The grindability of ceramics is related to the mechanical behaviors of materials at grinding temperature.
Monitoring of grinding wheel wear
E. Brinksmeier (2)  
STC G,  41/1/1992,  P.373
Keywords: Cylindrical Grinding, Data Acquisition, Monitoring, Optical Measurement, Wear
Abstract : A new optical sensor has been developed in order to monitor the cutting capacity of grinding wheels. This sensor is based on the principle of triangulation. For the investigation oft he grinding wheel topography even during the grinding process the sensor has been mounted at the opposite side of the working area of an external grinding machine. The output signals of the sensor are processed by a digital data acquisition /system /controlling the position of the sensor and calculating different parameters to describe the state of wheel wear. These parameters take various aspects of macroscopic and microscopic wheel wear into consideration. Some results which have been obtained using a corundum grinding wheel are presented. These results were achieved during the rotation of the wheel at cutting speed.
Surface topography assessment of high-precision coated abrasive tape and estimation of its machining performance
K. Yanagi, Y. Tsukada, R. Yamada   / H. Yoshikawa (1)
STC G,  41/1/1992,  P.377
Keywords: Abrasives, Roughness, Texture
Abstract : A topography assessment of coated abrasive tape was dealt with for distinguishing its functional performance. The three-dimensional distribution of projecting abrasive grains en a tape surface was presented and the related geometrical parameters for classifying the coated abrasive tapes were proposed. A comparison vas made between those parameters of the tape surface and the generated surface textures on the aluminum alloy substrate for magnetic/ /rigid disks. The topographical parameters of textured substrate surface which are based on the profile amplitude. microgeometry near the valley bottoms and their number were correlated fairly well with the spatial distribution of the effective coated abrasive grains in conjunction with working fluid or coolant.
On surface modification of superabrasive grits by CVD of chromium
A.K. Chattopadhyay, H.E. Hintermann (1)  
STC G,  41/1/1992,  P.381
Keywords: Diamond, CBN, Surface Modification, CVD of chromium
Abstract : In the present work, an attempt has been made to modify the surface of diamond and CBN grits in order to enhance their adhesion with the metal matrix. Chromium CVD process was used for this purpose. SEM and EP-NIA studies have shown that the type of chemical reagents, deposition time, deposition temperature and the type of abrasive grit substrate could influence the morphology and composition of the film deposited. Such surface modification was found to be more effective for diamond than for CBN in improving wettability and bondability of the Ni-based matrix. This was confirmed by improved retentivity of the diamond grits in the Ni-based matrix during simulated grinding test.
The real contact length between grinding wheel and workpiece : a new concept and a new measuring method
Z.X. Zhou, C.A. Van Luttervelt (1)  
STC G,  41/1/1992,  P.387
Keywords: Grinding Process, Maximum, Local and Real Contact Length, Contact Length Measurement, Grinding Zone
Abstract : Research on the contact length in grinding is needed to understand the grinding mechanism and for analysis of grinding operations. In this paper, a new concept for the grinding contact length is proposed. The contact length is distinctly divided into a maximum contact length and a local contact length. A new measuring method for both contact lengths, called the Applied Power Source or APS method, is presented. The results obtained show that the maximum contact length is about 22-50%37; longer than the local one. Awareness of the variation of the local contact length along the width of the contact zone results in a better understanding of the contact phenomenon between wheel and workpiece.
Galileo principe
M.C. Shaw (1)  
STC G,  41/1/1992,  P.393
Keywords: Grinding, Tmperature, Analysis, Heat Transfer, History
Abstract : In his second book "Dialog concerning two new sciences" published in 1638, Galileo made an amazing assumption that violates something as fundamental as static equilibrium. Yet, in applying this to many problems, he obtained correct answers. The reason is that he sought relative answers rather than absolute ones and the errors involved cancelled out. This is a useful analytical tool for engineering analysis which I call the dimensional analysis to the complex problem of estimating fine grinding temperatures in order to simplify the analysis and end result.

 STC M 

An automated planning, control and inspection system for robotic deburring
M.A. Elbestawi (2), G.M. Bone, P.W. Tam  
STC M,  41/1/1992,  P.397
Keywords: Robots, Deburring, Adaptive Control
Abstract : This paper describes a system for the automated planning, control and inspection of robotic edge deburring. The task planner uses an object oriented distributed artificial intelligence approach along with computer-aided design models to plan a collision-free path. The path is adjusted online to maintain the desired chamfer depth of cut using a high-bandwidth active end effector. The control system incorporates: a) sensor fusion of force and vision data, b) parameter adaptive predictive control, and c) learning control. Task completion is verified through in-process inspection of the chamfered edges. Simulation as well as experimental results are presented.
Adaptive control of a modular robot system
P.C. Mulders (2), R.J. Voorkamp, J. Jansen, A.C.H. Van Der Wolf (1)  
STC M,  41/1/1992,  P.403
Keywords: Robots, Adaptive Control
Abstract : Adaptive control is a process of modifying one or more parameters of the controller and these adaptive control algorithms are specially important for flexible manipulators with place and time dependent parameters, varying during trajectory performance. Here an adaptive controller is described as a combination of the computed torque method and an adaptive PD controller based on the Model Reference Adaptive Control (MRAC) method. It has been applied to a modular robot for loads up to 50kg consisting of a linear and a rotary actuator sowing these parameters variations. Necessary models, extended and reduced, of this modular robot have been made and the proposed controller has been tested in simulations and in the real configuration also with respect to stability, convergency and robustness.
Neural network control of robots
M. Shoham, C.J. Li, Y. Hacham, E. Kreindler   / R. Weill (1)
STC M,  41/1/1992,  P.407
Keywords: Robots, Control, Neural Network
Abstract : The abilities of/ /massive computation parallelism and self-learning make the neural networks a promising candidate for intelligent robot control. In this investigation, a robot controller consisting of inverse kinematics and inverse dynamics algorithms, has been replaced by two neural networks. A different approach to the neural networks learning phase made this solution applicable for robots control from the point of view of learning time as well as accuracy. First, the learning algorithm has been changed from the traditional back-propagation method to the quasi-Newton method. Secondly, the initial neural network weights which usually are chosen arbitrarily, have been determined in a systematic way based on a geometric interpretation of the neuron function. Simulation results show the significant improvement of both learning time and accuracy, which practically enables the use of a neural network controller in robotic applications.
Research on the efficiency of feed forward controllers in M
G. Pritschow (1), W. Philipp  
STC M,  41/1/1992,  P.411
Keywords: Position Controller, Path Errors, Feedforward Control, Predictive Control, Uncertain Parameters, Direct Drives, Path Accuracy
Abstract : The path accuracy of machine tools and industrial robots is influenced by the characteristics of the control loops of all axes that are involved in the course of the path. In comparison to classical electromechanical drives, direct drives allow considerably higher accuracies and velocities. The control error can be reduced further by additional feed-forward controls. In he course of this paper, feed-forwards control procedures developed at our institute at the University of Stuttgart are presented and compared to known procedures for the use in direct drives. This comparison mainly concentrates on the influence of parameter uncertainties and the resulting path behavior.
Automatic design of tuning parameters for predictive control of CNC machines
P. Boucher (2), D. Dumur (2), S. Daumüller  
STC M,  41/1/1992,  P.417
Keywords: CNC,Control System, Machine Tool
Abstract : Predictive control laws nowadays appear to be successfully implemented on many French and German C.N.C. machines and ensure sufficient performances in term of rapidity, disturbance and errors cancellations. But even if the control law remains very simple, there is up to now no method that provides the best set of tuning parameters it a systematic way and without any help. We propose in this paper an original and automatic design of these parameters, giving at the end the best tuning in Term of robustness and stability of the predictive control law. With this method based on simple frequential considerations, and even if the user has no particular knowledge about predictive control, the result for the C.N.C. machine is a robust and stable control algorithm corresponding to the desired performances. Experimental results prove the validity and usefulness of this new approach.
Ultra-precise machine tool equipped with a giant magnetostriction actuator
H. Eda, E. Ohmura, M. Sahashi, T. Kobayashi   / N. Ikawa (1)
STC M,  41/1/1992,  P.421
Keywords: Ultra-Precision Machining, Actuators, Diamond Turning Machines, Brittle-Ductile Transition, Giant Magnetostriction
Abstract : By developing several alloys with the composition Tb_x Dy_1-x (Fe_y Mn_1-y )_n , a giant magnetostriction actuator was manufactured. The output power of them is several times and the displacement is several ten times as much as PZT without a magnifier. A temperature controller to keep a fluctuation of the cooling water within 10m°C was developed for the actuator. An ultra-precise machine tool was also developed, equipping the present actuator. The depth of cut can be set with the accuracy of several nanometers by the actuator and cut by a turning diamond tool. The hard and brittle materials such as glass and ceramics were finished in ductile mode, and the surface roughness was obtained within several nanometers.
Structural configuration and performances of machining environment-controlled ultra-precision diamond turning machine "Capsule"
H. Shinno, H. Hashizume, Y. Ito (2), C. Sato  
STC M,  41/1/1992,  P.425
Keywords: Ultra-Precision, Machine Tools, Diamond Turning Machine
Abstract : To establish a future ultra-precision machining technology of nano-meter order, it is important to realize the machine tool structure based on a new design concept. Therefore, a Machining Environment-Controlled Ultra-Precision Diamond Turning Machine has been newly developed. This machine can be characterized by capsule-like closed structure along with various new mechanisms. The machine aims especially at the manufacture of the high precision mirror under various environments. At present, the flat mirror with 3 nm in surface roughness (Al-alloy) is in reality/.
Instrumented milling cutter for in-process measurement of spindle error motion
S.A. Spiewak (2)  
STC M,  41/1/1992,  P.429
Keywords: Sensors, Spindles, Errors
Abstract : An instrumented cutter developed for a new generation of machining centers designed specifically for die making in the car industry is presented. A three-component accelerometer installed inside of the cutter facilitates the measurement of spindle error motion exactly at the cutter location. The method of signal conversion from accelerations measured by the rotating sensor into the spindle displacements in the machine tool reference system is outlined. A setup used in the laboratory tests and representative results are presented.
Stabilizing chatter by automatic spindle speed regulation
S. Smith, J. Tlusty (1)  
STC M,  41/1/1992,  P.433
Keywords: Milling, Chatter
Abstract : This paper describes the theoretical basis behind a system for the elimination of chatter in, milling through the automatic regulation of the spindle seed. This technique is most effective in milling operations where the tooth passing frequency can approach the natural frequency of the mode responsible or chatter. Examples detailing the convergence process are presented, and non-convergence situations are described. Experimental data are quoted to illustrate typical improvements in metal removal rate. The various modes of operation of the system are described.
Automated rapid prototyping utilizing laser scanning and free form machining
C. Bradley, G.W. Vickers   / J. Tlusty (1)
STC M,  41/1/1992,  P.437
Keywords: Laser Scanners, CNC Machining, Multiple Surface Patches, Free-Form Surfaces, Quadric Surfaces
Abstract : The paper deals with the use of a laser based method for rapid prototyping of free-form and quadric surface multiple patch models. Integration of a triangulation based laser scanner with a CNC machining center is discussed. Methods of analysis of the mass of irregular and unformatted positional data generated by the scanner are presented in order for a series of basic quadric and compound curved surfaces to be defined. The procedure for defining the CNC cutter path for a generalized shaped end-milling cutter is given with illustration of the applicability of the method to a variety of test objects. The work is a new approach utilizing laser scanned data for direct machining of quadric and free-form surfaces.
Collaborative coordination control (CCC) of distributed multi-machine manufacturing
S.Y. Nof   / R. Weill (1)
STC M,  41/1/1992,  P.441
Keywords: Optimization, Distributed Control, Flexibility, Coordination
Abstract : Coordination control of multi-machine workstations in distributed FMS and other manufacturing facilities has been designed with synchronous and asynchronous techniques. In a recent study at Purdue, the element of machine collaboration has been added to the coordination control, to add to the flexibility and reliability properties of the processes. The new Collaborative Coordination Control strategy is explained and illustrated with two specific implementation case studies based on one U.S. and one French FMS facility. Impacts on performance measures are evaluated. Certain advantages, limitations and open questions of the approach are discussed.
Precision turning by means of a simplified predictive function of machining error
T. Asao, Y. Mizugaki, M. Sakamoto   / H. Sato (1)
STC M,  41/1/1992,  P.447
Keywords: Turning, Errors, Compensation
Abstract : This study deals with a compensative system for machining errors in turnings by adopting a simplified predictive function and modifying previous NC commands. The predictive function is represented in .he form of an exponential function as an experimental expression and installed into an auto NC programming tool as a database. A NC command is modified by varying its depth of cut from which the notion resolution of a lathe subtracted everywhere the predicted machining error exceeds the motion resolution. The experimental results support the efficiency of the compensative system proposed in some intermittent metal cutting.
Investigation into temperature dependence of motor current measurements applied to monitoring and adaptive control
M.A. Mannan (2), S. Broms  
STC M,  41/1/1992,  P.451
Keywords: Adaptive Control, Temperatures, Tool Wear
Abstract : It is a crucial requirement, when using motor-current-based sensing systems, that the ratio between cutting forces and the corresponding motor currents is constant during the period of observation. Different induction motors employed in spindle and teed drives have been shown to have different sensitivities to heating cycles, depending upon their design and the magnetic materials used in them. Besides the changes in electro-magnetic losses due to temperature variations, changes in mechanical losses in different components incorporated in machine tool drives are the major contributory factors. We have experimentally studied the effect of the above-mentioned factors on the accuracy of motor current measurements, taking into account variations in temperature.
A new approach to modelling thermal behaviour of machine tool under service conditions
J. Jedrzejewski (1), W. Modrzycki  
STC M,  41/1/1992,  P.455
Keywords: Machine Tool, Modelling, Thermodynamic Properties
Abstract : The paper presents a new method of modeling thermal behavior of a machine tool in service based on integrated determination of power losses in the kinematic system components, temperature and thermal displacement. The method is applicable to any operational conditions. The mathematical model and its organization are presented. Basic features of the method are shown in a case of a machining center whose services thermal behavior is analyzed.
Influencies on the availability of FMS
U. Heisel, H. Hammer   / G. Pritschow (1)
STC M,  41/1/1992,  P.459
Keywords: Availabitily, FMS
Abstract : A major prerequisite for the economical operation of Flexible Manufacturing Systems is a high level a availability. This is determined, on the one hand, by technical factors and, on the other hand, by limitations in the corporate organization and personnel. The paper presents results of a field study in which reasons for breakdowns caused by technical errors and inadequate organization are viewed in relation to the effects of insufficient qualification and motivation of personnel.
Processintegrated measurements for quality control with turning
H. Trumpold (1), R. Mack  
STC M,  41/1/1992,  P.463
Keywords: Processquality, Sensorsystem, Turning, Force Measurement, Monitoring
Abstract : The paper deals with a process integrated piezoelectric force sensor system working in a frequency range of 5 Hz...20 kHz. Together with the software for the evaluation of the continuous dynamic signal the system allows the determination of deviations from the normal teach-in function of parameters typical for the process within one workpiece revolution or within defined time intervals. The efficiency of the measuring and quality monitoring strategy and the correlation between dynamic forces and disturbances within the system machine-tool-work-fixture are described. The investigations were made on one and multi-spindle lathes.
Optimization of design tolerances of servomechanisms
H.H.B. Roelofs, C.J. Heuvelman (1)  
STC M,  41/1/1992,  P.467
Keywords: Servomechanisms, Optimization, Tolerancing
Abstract : A method is proposed to specify maximum tolerance ranges on nominal values of system parameters of servomechanisms and the nominal values themselves using semi-infinite optimization algorithms. The performance specifications of the servomechanism are transcribed to semi-infinite inequalities. The feasible design area is assumed to be convex. The dynamic behavior of the servomechanism is represented by a linear state space model.

 STC O 

Approach to the identification and quantification of environmetal effects during product life
R. Züst, R. Wagner   / B. Schumacher (1)
STC O,  41/1/1992,  P.473
Keywords: Organization of Product Development, Cost Analysis, Environmental Impact, Product Life-Cycle, Ecological Balance, Extended Quantification
Abstract : Rising environmental costs and their transfer to those who incur them become serious hazards for the industrial enterprise. To avoid these hazards special activities have to be adopted during the product development phase. Quantifiable evaluations covering all phases of a product's life are of great significance for product development. The authors conclude that using existing ecological balances is not a suitable method. Further quantification is necessary, which deals with costs, material flows, energy flows, mixing of materials, hazards, damage and ethical aspects.
A new system for automatic understanding engineering drawings
L.Y. Zhang, J.Y. Zhu (1), Q.Y. Zhu  
STC O,  41/1/1992,  P.477
Keywords: Computer Vision, Engineering Drawing, Automatic Understanding
Abstract : A new system which can understand engineering drawings automatically and convert the result data to CAD / CAM system is introduced in this paper. Engineering drawings are inputted into a vision system via a CCD camera as an image. First, algorithms for preprocessing the image to remove noise, segment the image, and convert raster image to vectors are presented. Then, contours are fitted to straight lines, arcs and symbols in the drawings are recognized. Finally; after editing, the result data is transformed to CAD CAM system to obtain machine program.
Design for manufacture : expert processing sequence selection for early product design
J. Farris, W.A. Knight (2)  
STC O,  41/1/1992,  P.481
Keywords: Design for Manufacture, Process Selection, Material Selection
Abstract : A method to systematically map part geometry and material requirements onto sequences of processes and compatible materials is described. The geometrical and material constraints of the design are input information for the system. The system produces a list of practical processing sequences and material combinations. The sequences are ranked according to the difficulty of manufacturing the part with particular processes selected and how well a material meets the material requirements for the part.
Dynamic optimization of job distribution on machine tools using time decomposition into constant job-mix stages
L. Kops (1), S. Natarajan  
STC O,  41/1/1992,  P.485
Keywords: Production Scheduling, Job Allocation, Dynamic Optimization, Linear Programming
Abstract : A new concept of time decomposition which allows to combine linear programming and heuristics to solve the dynamic problem of job distribution on machine tools for a scheduling horizon is presented. An optimization algorithm based on this decomposition principle and which considers also the setup time is described. The application of the algorithm is demonstrated on a case of multiple-operation job processed according to the arrival and due date schedule, on machine tool grouped in sections according to operations. The results indicate that the optimization based on the concept of time decomposition into constant job-mix stages, CMS, leads to increased utilization of machine tools, higher production rate in sections, with shorter makespan of individual jobs and reduced computational time.
A CAPP system for non-linear process plans
J.P. Kruth (2), J. Detand  
STC O,  41/1/1992,  P.489
Keywords: Computer Automated Process Planning (CAPP), Knowledge Based Systems, Petri Nets, Non-Linear Process Plans
Abstract : Non-linear process plans are process plans which comprise different manufacturing alternatives. Such non-linear process plans increase the flexibility of scheduling activities, and allow to remedy quickly to disturbances in the workshop. They are represented by Petri nets. The automatic generation of a non-linear process plan is realized in different steps - the feature based workpiece description is transformed into a non-linear sequence of operation steps - the resources, capable to manufacture the specified operation steps, are determined - the non-linear sequence is converted into a non-linear process plan which is directly usable for scheduling. The developed CAPP system has been tested for hydraulic components.
Application of flows and envelopes to NC machining
D. Blackmore, M.C. Leu (2), K.K. Wang (1)  
STC O,  41/1/1992,  P.493
Keywords: Geometric Modeling, Numerical Control, Machining
Abstract : The characterization and representation of swept volume has important applications in NC machining theory and practice. Modern NC programs are quite versatile: they provide programmers with the capacity of performing a variety of possible types of motion for the cutting tool such as linear, circular, helical, parabolic and cubic interpolation. Using the method of sweep differential equations, techniques which incorporate the method of envelopes are developed for constructing the swept volume of simple tools which are generated by topical motions in NC programs. The technique for linear, circular and helical motions is shown to effectively reduce the dimension of the problem by two. For completely general motions it is shown that the procedure can be best effectuated by first imbedding the configuration in a space of one more dimension. Several examples are included to illustrate the implementation of the methods which are introduced.
Computer aided analysis and planning of set-up process
H.P. Wiendahl (1), Z. Fu  
STC O,  41/1/1992,  P.497
Keywords: Set-Up Process, Set-Up Structure, Analysis, Planning
Abstract : To adapt the consequence of set-up time for the manufacturing process and the enterprise success, it is necessary to consider systematically the set-up process in the production. The paper shows a method, which enables to analyze the set-up process and derive measures for set-up time reduction upon the basis of ascertained weakness. The necessity of the planning of the set-up process in analogy to manufacturing process results from the existing problems in the set-up organization. A prototype of such planning system has been developed to equip the set-up personnel with aids, which make a structured and disturbance free set-up process possible.
An intelligent sensor for robotics
D.T. Pham   / A.W.J. Chisholm (1)
STC O,  41/1/1992,  P.501
Keywords: Robotics, Sensors, Part Feeding
Abstract : The paper describes a novel low-cost sensor based on the measurement of inertia-sensitive parameters to detect the location of workpieces in robotic assembly or pick-and-place applications. The sensor is a vibrating system comprising a platform which holds the workpiece to be located and a flexible column which supports the platform. The inertia-sensitive parameters used are the natural frequencies of this vibrating system. A transputer is employed to process the vibration signals to obtain the exact coordinates of the workpiece relative to the platform. The processing techniques described include Kalman filtering and fuzzy interpolation.
Real-time machining state detection using multi-axis force sensing
M. Mitsuishi, T. Nagao (2), Y. Hatamura, S.I. Warisawa  
STC O,  41/1/1992,  P.505
Keywords: Real-Time Machining State Detection, Force Vector Locus, Intelligent Machining
Abstract : To realize fully-automated, intelligent machining, it is necessary to develop a method for judging the machining state in real-time. A method for determining the machining state in milling is described. The technique utilizes the ^" force vector locus" determined from the measured force data. The variance in the distance from the center of gravity to each sample point is used to distinguish between normal cutting and chatter conditions. Because the variance depends on the cutting conditions, as well as on the cutting state, the threshold variance is set relative to the ideal variance calculated from the Kronenberg cutting force model. Experiments have demonstrated the utility of the technique in actual milling operations.
Robotic workcell cycle time optimization using computer graphics
R.G. Fenton (1), D. Poon, S.P. Davies  
STC O,  41/1/1992,  P.509
Keywords: Robot, Workcell, Cycle Time
Abstract : The position of a robot within a flexible manufacturing workcell, where machine station and storage locations are predetermined, plays an important role in determining the cell's cycle time [1]. In this paper, the optimum position of the robot (defined as the position of the robot in the workcell that results in the minimum cycle time) in a multi-location industrial workcell is determined through the use of a numerical optimization routine and ROBCAD, a kinematic computer graphics simulation program.
Cutting conditions optimization in 3 axis NC milling
K.D. Bouzakis (2), R. Paraskevopoulou  
STC O,  41/1/1992,  P.513
Keywords: Milling, Process Simulation, Cutting Forces, Tool Wear, Cutting Conditions Optimization
Abstract : For the optimization of the cutting speed and feed rate in 3-axis NC-milling a computer supported procedure is presented. Input to that procedure is the NC- code off a part. The tool motions, derived from the NC-code, are grouped in subprocesses. Considering the manufacturing cost and accuracy, using developed models, which enable the calculation of the cutting force components and the tool wear, the optimum feedrate and cutting speed values along the tool path are calculated. These optimum cutting conditions are automatically implemented into the NC-code, which is properly modified. An application example of the developed procedure is presented.
An integrated cutting tool selection and operations sequencing method
H.M. Rho, A.H. Van't Erve, H.J.J. Kals (1)  
STC O,  41/1/1992,  P.517
Keywords: CAPP, Operation Sequencing, Tool Selection
Abstract : Within the PART CAPP system, the selection of an optimum operation sequence is related to the modules which perform the machining method and cutting tool selection. This study analyzes the technical and economical aspects of operation sequencing and presents a method which is capable of generating an optimum solution on the basis of previously selected machining operations and alternative cutting tools per operation. Precedence relations between operations provided by the method selector are used as constraints which should not be violated. The operation sequencing method simultaneously assigns single tools from a list of alternatives to each operation and manipulates the operation sequence in order to minimize the total number of tool changes and the number of required tools.
Building wider scope integrated manufacturing systems
R.H. Weston   / B.J. Davies (1)
STC O,  41/1/1992,  P.521
Keywords: Integrated Industrial System, Information Management System, Computer Integrated Manufacturing
Abstract : The industrial use of an 'open' approach to building integrated manufacturing systems is described and compared with conventional turnkey and custom built solutions. The case study system developed by the author integrates planning, supervision and change control operations, along with information support and management functions. The paper shows how the approach is applied to four in production surface mount technology assembly lines. The benefits of the 'open' approach are documented in terms of very significant savings in engineering cost and time. Furthermore the paper illustrates how the extendibility of the open approach can lead to enterprise-wide integration.
A generator for creating adaptive post processors
A. Blumfield, M. Shpitalni (1), E. Lenz (1)  
STC O,  41/1/1992,  P.527
Keywords: Adaptive Post Processor, CAD/CAM, CNC, Manufactuing Philosophy
Abstract : The combination of modern CAD/CAM systems with CNC machines allows for creation of adaptive post processors with significant advantages over the classical post processors: (1) They generate g-code which reflects the manufacturing philosophy of the individual user; (2) They use technological tables for automatically obtaining various machining parameters; (3) They make better use of the CNC programming options, producing compact legible code with better manufacturing quality; and (4) They can be modified on site during installation. A special generator for creating such adaptive post processors has been developed and is represented in this paper.
Fractal path generation for a metal-mold polishing robot system and its evaluation by the operability
Y. Mizugaki, M. Sakamoto   / T. Sata (1)
STC O,  41/1/1992,  P.531
Keywords: Mechatronics, Polishing, Robot Programming
Abstract : This paper suggests a new method of Fractal path generation in a robot system of polishing metal molds. It is conducted through the generation of a planer Peano curve in the X-Y domain and its orthogonal projection onto the free-form surface of a workpiece The orientation of the end-effector along the path is set perpendicular to the surface. By calculating the sum of operability of the robotic linkage along the path, the path can be evaluated from the ease of the robots' motion. The experiments inclusive of the polishing force control are illustrated and a beef conclusion made.
CAD-CAI Integration for complex surfaces
D.V. Majstorovic, p. Bojanic, V. Milacic (1)  
STC O,  41/1/1992,  P.535
Keywords: CAD-CAI, Complex surfaces
Abstract : The integration of systems in the field of engineering activities on the basis of CA technology begins with the establishing of internal model of a workpiece in CAD system. Feature-based modeling offers a number of advantages over the classical geometrical modeling in the building of integrated systems. This paper describes the architecture of CAD/CAI (Computer Aided Design/Computer Aided Inspection) integrated system based on the recognition of forms and artificial intelligence. As specific forms in the model may also appear the forms with complex surfaces. Initial result of the investigation justifies such an approach in the integration of systems in the field of CA technologies.
Generation of 5-axis control collision-free tool path and post-processing for NC data
Y. Takeuchi (2), T. Watanabe  
STC O,  41/1/1992,  P.539
Keywords: Machining Center, Tool Path, Postprocessing
Abstract : The study deals with the general method of generating NC data from collision-free tool path of 5-axis control machining centers. The use of 5-axis control machining centers, capable of machining complicated workpiece shapes efficiently and accurately, is recently increased. Then, it is inevitable to generate collision-free CL data and NC data rapidly. CL data are generated by the main-processor having the collision avoidance procedure between a workpiece and an arbitrary tool shape, based on the solid modeling technique. The post-processor developed in the study can convert CL data to actual NC data, taking account of the structure of machining centers. The main- and post-processors are experimentally found effective.
Computer aided run-in of CNC-programmes
H. Weule (1), M. Klaiber  
STC O,  41/1/1992,  P.543
Keywords: Optimization of Manufacturing Systems, Shop-Floor-Orientation, Run-In of CNC-Programmes
Abstract : To date the necessary rationalization procedures in the manufacturing environment to achieve competitive advantage have taken place mostly, from a high level, centralized point of view within organizations. Additional competitive success can only be achieved through consequential shop floor orientation. Existing resources at the shop floor level, for example processing proximity and manufacturing know-how can be used to advantage. In this paper, a shop floor oriented approach is presented using the example of reduction of the run-in time of CNC-Programmes. A computer aided method for the run-in of CNC-Programmes is presented. Up to now this task has been undertaken empirically. The result is a transparent, well structured and thus target oriented run-in system which assists the production planning process and which leads to significant time saving.
A generalized kinematics model for three to five axis milling machines and their implementation in a CNC
A. Rüegg   / P.E. Gygax (1)
STC O,  41/1/1992,  P.547
Keywords: CNC, Kinematics
Abstract : Currently, it is only possible to program the milling of complex shapes by giving the axis cutter location points in ISO programs. With these programs, it is not possible to apply corrections and fixture compensation at the machine. Using a generalized kinematics model and a uniform algorithm, working from the tool osculation point information, it is possible to calculate the axis values for 3, 31/2, 4, 41/2 and 5 axis milling machines, thus supporting all the most important kinematic designs of milling machines. This method is implemented in a CNC controller, making it possible to perform the kinematic calculations online on the machine. This has the advantage that the same NC program can be used for different 5 axis machines (with different geometry) without needing to rerun a postprocessor program.
Block-like component CAD/CAM system for fully automated CAM processing
T. Hoshi (1)  
STC O,  41/1/1992,  P.551
Keywords: CAD-CAM
Abstract : For the purpose of fully automating the transformation of CAD designed product data into the information necessary for machining the product, a new method of machining feature-based CAD/CAM has been investigated. By modifying the existing Parametric Feature-Based CAD methodology into one using only geometrical features machinable by defined cutting technologies, a Machining Feature-Based CAD system has been developed, by which it is possible to fully automate the processing of the succeeding CAM tasks for fabrication of block-like components. The CAD/CAM system has demonstrated a future possibility of highly automated production of low volume high product-mix items of block-like components which fall into a sub-set class of prismatics.
Model-based learning for diagnostic tasks
D. Specht, S. Weiss   / G. Spur (1)
STC O,  41/1/1992,  P.557
Keywords: Knowledge-Based Systems, Diagnostic Routines, Production
Abstract : Despite many years of research, the two problems of knowledge acquisition and maintenance of a growing knowledge base while preserving consistency are still largely unsolved. This paper introduces an approach which supports/ /the acquisition of diagnostic rules by learning from examples representing the experiences of domain experts. Using a model of the system to be diagnosed, these heuristic rules are consistency checked before they are added to the knowledge-base. Moreover, this model/ /constitutes a base for learning by transforming analogous cases into actual problems when the system is operational.
Quality control in a flexible manufacturing cell
Z. Idelmerfaa, F. Lepage, J. Richard, M. Véron (1)  
STC O,  41/1/1992,  P.561
Keywords: Quality Control, Information System, Distributed Control, Flexible Manufacturing Cell
Abstract : This paper presents a quality control loop architecture of a flexible manufacturing cell. The cell is considered as an autonomous system which produces parts and controls their quality and which manages its own equipment and adapts its behavior according to the most recent information. The quality control in the cell is based on two principles concepts: - management of all technical and quality information in the cell information system, - distributed control of the cell on several levels to perform correction as fast as possible. An application using a MAP local area network and SQL server realized in the C.R.A.N, is described.
Clearance space in volumic dimensioning
M. Giodano, D. Duret, S. Tichadou, R. Arrieux (2)  
STC O,  41/1/1992,  P.565
Keywords: Tolerancing, Clearance, Functional Dimensioning
Abstract : This paper presents a theoretical representation of the notion of clearance between two parts connected by prismatic surfaces. In order to characterize the clearance, the latter is associated to a fictive volume represented in a three-dimensional space, which is not the real space of the mechanical parts. The properties of the clearance volume are studied. An example is presented. A generalization to the volumic case is considered. This method allows to develop a model that can be used from different points of view: computer aided functional tolerancing, manufacturing and control.
Simultaneous optimization of design and manufacturing tolerances with process (Machine) selection
C. Zhang, H.P. Wang, J.K. Li (2)  
STC O,  41/1/1992,  P.569
Keywords: Design and Manufacturing Tolerance, CAPP, Optimization
Abstract : Tolerance design and synthesis is a major task of product and process design and is in a period of extensive study due both to increased demands for quality products and to increasing automation of machining and assembly. Optimum tolerance design and synthesis ensures good quality product at low cost. This paper provides an analysis of simultaneous optimization of design and manufacturing tolerance syntheses with consideration of process (machine) selection. The tolerance synthesis problem is formulated as a mixed nonlinear optimization model, which has as its objective the minimum total manufacturing cost. A new global optimization algorithm simulated annealing is coded to solve the optimization problem. An example for illustrating the model and solution procedure is provided.
A new approach to manufacturing engineering education
O. Bjorke (1)  
STC O,  41/1/1992,  P.573
Keywords: Education, Systems
Abstract : The paper points at the development towards a generalized systems theory, which may be used to model the many topics covered in manufacturing engineering education. This leads to the possibility to harmonize the education in today's curricula consisting of separated vertical blocks. The other important aspect in the paper is the trend towards automatic formulation of system equations. These developments will in the years to come force a major change in engineering curricula.

 STC P 

Fiberoptics for in-line production measurement
T. Pfeifer   / W. König (1)
STC P,  41/1/1992,  P.577
Keywords: Fiberoptics, Sensors, Threads, Metrology
Abstract : The contribution deals with the laser-optical internal thread measurement, with the aim to define quality-parameters, such as: diameter, flank lead, break etc., automatically. The special fiberoptic and laser-based sensor techniques as well as the data processing method and evaluation algorithms are described.
Distance-Distance method for straightness measurement
G. X. Zhang (1), X.H. Chu, W. Tang, Z.Z. Jin  
STC P,  41/1/1992,  P.581
Keywords: Precision, Measurement, Straightness, Distance-Distance Method
Abstract : A new method for straightness measurement based on distance measurement from two reference points is introduced in this paper. The distinguishing feature of this method is that it does not require a straightness reference. It gives high accuracy due to high accuracy in displacement measurement. A practical device used for quick distance measurement based on a turnable laser interferometer with two end balls is designed. Accuracy analysis of the instrument is given in detail. Theoretical analysis and experiment show that this method gives high accuracy in straightness and straightness error motion measurements.
Angular measurement by means of rotation of linear gratings
F.S. Jing, Y.C. Lin, Y.F. Zhou   / G.X. Zhang (1)
STC P,  41/1/1992,  P.585
Keywords: Precision Measurement, Moire Fringes, Microcomputer, Real Time
Abstract : A newly patented technique for precision angular measurement by means of mutual rotation of linear gratings is presented in this paper. An analysis of variation of moire fringes based on theory of Fourier Optics is given in accordance with the specific conditions, Processing of signals is done in real time by a microprocessor. Both theory and experiment show that angles can by measured more accurately with the aid of the new technique.
Automatic detection of defects among small pins-group
Y. Furukawa (1), H. Sakuma  
STC P,  41/1/1992,  P.589
Keywords: Neural Network, Inspection, Image Processing
Abstract : Some defects among a large number of electronic connector plug pins inserted into a board being inspected manually today, can be automatized by the proposed system which consists of an image processor associated with neural network. Images which are caught by ITV camera is first processed to binary signals, then input to the first layer of the network, which is composed of other 2nd and 3rd layer, each of which is programmed by so-called "Back-Propagation" algorithm. The network learns many types of defects in advance and decides strength of each net, with which compares the actual image of pins. Fundamental features of the proposed system were made clear and the network could well detect such defects as beaded, buckled and mis-positioned pins.
Three dimensional cognitive system for quick perception and inspection of mechanical part using computer tomography
K. Yamazaki (2)  
STC P,  41/1/1992,  P.593
Keywords: Dimensional Measurement, Image Processing, Geometric Modelling
Abstract : The paper deals with a new method for the efficient and autonomous perception and inspection of three dimensional geometry of a mechanical part. The method developed is based on a high power X-ray CT (Computer Tomography) applied image capturing and three dimensional computer image processing. The system was developed such that a geometric model of the part can automatically be reconstructed as a computer software model with newly developed algorithms which can autonomously perceive three dimensional geometry features of the part. The feasibility of the proposed method was successful demonstrated by the experiments using the developed system.
An universal algorithm for the alignment of any sculptured surface
G. Goch, U. Tschudi   / J. Pettavel (1)
STC P,  41/1/1992,  P.597
Keywords: Coordinate Measurement Techniques, Sculptured Surfaces, Alignment and Approximation, Deviation Function
Abstract : Sculptured surfaces are often given/ /by a set of discrete nominal points and the corresponding normal directions (e.g. bevel gear flanks, turbine blades). The alignment of these workpieces leads to significant problems, as conventional algorithms based on the L_2 -norm (Gauss) or Tschebyscheff-norm (T-norm) require a surface description by mathematical functions. In this paper a new alignment-algorithm will be explained, which needs as input data only a set of nominal points together with their normal directions and which delivers as output data the alignment operator (rotation matrix and displacement vector). Both L_2 -norm and T-norm are available as objective functions. The surface can be contiguous or composed of different areas distributed over the workpiece (e.g. different teeth-flanks); no functional description is necessary. Basic mathematics will be discussed and results obtained by measurements will be given.
Performance analysis of feed-drive-system in diamond turning by machining specified test samples
T. Bispink   / M. Weck (1)
STC P,  41/1/1992,  P.601
Keywords: Diamond Turning Machines, Form Accuracy, Tests
Abstract : In the field of ultraprecision machining proper performance of feed drive systems is necessary. Smallest depths of cut, smooth surfaces and minimal shape errors of complex parts are required. To test the behavior of high precision feed drive systems several direct and indirect analysis methods can be applied. In this report three indirect test methods are presented. By machining and evaluation of specified workpiece samples information about the feed drive behavior are obtained. Correlations between surface-shape, surface-describing parameters and the position data of the cutting tool are made. The work is to be considered as a contribution to the testing of ultraprecision machine tools.
The optimum crystal plane of nature diamond tool for precision machining
Z.J. Yuan (1), J.C. He, Y.X. Yao  
STC P,  41/1/1992,  P.605
Keywords: Ultra-Precision Machining, Single Crystals, Diamond Tools, Friction, Wear Resistance
Abstract : Because of the strong anisotropism of single crystal diamond, the optimization of crystal plane becomes very important and crucial in manufacturing of single point diamond tool. The friction states between the rake and the flank of diamond tool and workpiece materials affect shear deformation, tool wear and the quality of machined surface directly. In this paper, the writers investigated the friction coefficients between diamond oriented various crystallographic direction and non-ferrous metals by experiment simulating friction states of ultra-precision machining, and find out that the friction coefficients is not only different with different crystal planes, but also different with different directions in the same crystal plane. These experiments lead to the conclusion that (100) plane is the optimum plane for the rake and the flank of single point diamond tool.

 STC S 

Predicting microcontact spots size distribution in contact problems
L. Klimczak   / J. Kaczmarek (1)
STC S,  41/1/1992,  P.609
Keywords: Roughness, Real Contact Area, Contour Map, Contact Spots Size Distribution
Abstract : When two parts are in contact surface roughness causes contact to occur at discrete contact points. Number of contact spots and their individual size are essential information to understand many tribological situations. They can be predicted from geometrical intersection between surface and plane ? the surface roughness contour map. In this paper, variation of contact spots size distribution with intersection level was evaluated from contour maps of surface produced by common machining processes. This was compared with contact spots distribution obtained for surfaces deformed plastically.
Surface studies during indexable drilling with coated carbides of different geometry
V.C. Venkatesh (1), W. Xue, D.T. Quinto  
STC S,  41/1/1992,  P.613
Keywords: Indexable Drill, Surface Integrity, Negative Point Angle, Coated Carbides
Abstract : Three types of indexable drills (A, B, and C) were used to drill 1018 steel, copper, and aluminum alloys. The inserts used were 80° rhomboid, square, and trigon shaped giving different side cutting edge angles (SCEAs). The inserts had three types/ /of coatings and one uncoated: Drill A TiC (CVD), Drill BI TiN/A1_2 ,O_3 , multi-layer (CVD), Drill B2 TiN (CVD), and Drill C (uncoated). In one type of drill both outer and inner inserts had only one cutting edge each, whereas in the other two types, two cutting edges were presented. Roundness, surface roughness, angularity, waviness, chip root, photoelastic, microscopic, and X-ray diffraction studies were carried out. Drill A with a -ve SCEA and a TiC coating on a cobalt enriched surface. and Drill B1 with a TiN/A1_2 O_3 coating gave the best surface finish and roundness values and the reasons for this are highlighted in this paper.
Robot kinematics for the free-form polishing of deformable Bezier-type surfaces
K.T. Yap (2), Y. Yokokohji  
STC S,  41/1/1992,  P.617
Keywords: Hybrid Control, Electrochemical Polishing, Bezier Surfaces, Contact Sensors
Abstract : The exact model of dynamic forces required to control a robot to follow a Bezier-type surface is developed in this paper. Implementation using a contact sensor to enable the polishing tool fixed at the end-effector for hybrid controlled is discussed. The experimental set-up led to the discarding of terms in the original kinematic equations which are insignificant compared to friction and actuator dynamics due to slow tool advance velocity involved in electro-chemical polishing. Some problems relating to the "look ahead" mechanical sensor are also addressed.
The use of 3D topographic analysis to determine the micro-geometric transfer characteristics of textured sheet surfaces through rolling
K.J. Stout, P.J. Sullivan   / P.A. McKeown (1)
STC S,  41/1/1992,  P.621
Keywords: 3D Surface Topography, Surface Analysis, Textured Sheet, Rolling, 3D Parameters
Abstract : Traditionally, rolling mills were used for the purposes of flattening metal sheet, and reducing its thickness. However recently their use has been extended to provide a method for producing sheet with specified textures. The transfer characteristics of a textured roll to a sheet may be investigated qualitatively and quantitatively using a number of different approaches. Quantitative techniques include the use of 2-dimensional profilometry which is obviously inherently limited in its ability to characterize a 3-dimensional (3-D) surface. Although 3-D surface topography measurement systems have been available for/ /some time, 3-D characterization techniques are still in their infancy (particularly with functional significance). The aim of/ /this paper is to show how the use of 3-D characterization techniques may be used to qualitatively and quantitatively analyze engineering surfaces. In this paper the texture transfer characteristics of sheet rolling is explored and the extent of transfer is determined. The technique employed shows how the integrity of topography transfer may be established with a limited basic set of 3-D parameters through the analysis of parameter variation. Art area material ratio curve is also introduced and its usefulness in the comparison of the amplitude distributions of two surfaces is demonstrated.