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CIRP Annals Online sorted by Year and Volume




Design for Assembly and Disassembly
G. Boothroyd (1), L. Alting (1)  
STC A,  41/2/1992,  P.625
Keywords: Design, Assembly, Disassembly
Abstract : A review is made of design for assembly (DFA) methods developed over the last fifteen years. It is found that implementation of DFA at the early conceptual stage of design has led to enormous bene255fits including simplification of products, lower assembly and manufacturing costs, reduced overheads, improved quality and reduced time to market. DFA is now being broadened to include consideration of the difficulty of manufacture of the individual parts to be assembled and is providing the necessary basis for teamwork and simultaneous engineering. More recently, environmental concerns are requiring that disassembly for service and recycling be considered during product design - in fact, total life cycle costs for a product are becoming an essen255tial part of simultaneous engineering. This keynote paper concludes with a discussion of current de255velopments of design for disassembly (DFD).


High Speed Machining
H. Schulz (1), T. Moriwaki (1)  
STC C,  41/2/1992,  P.637
Keywords: High-Speed Cutting, Hsc-Machine Tools, Cutting Tools
Abstract : The high speed machining is now recognized as one of the key manufacturing technologies for higher productivity and throughput. The paper reviews recent development in high speed machining and related technology especially in the last decade. The state of the art of high speed cutting, cutting tools and machine tools for high speed cutting are presented. The realization of hsc demands new unconventional solutions for machine tools and their components. The optimization and the safety precautions of the tools are very important. Time reduction of more than 50% can be achieved.

 STC Dn 

Concurrent Engineering
G. Sohlenius (1)  
STC Dn,  41/2/1992,  P.645
Keywords: Concurrent Engineering, Manufacturing, Design
Abstract : The term Concurrent Engineering, also called Simultaneous Engineering, was used the first time in the US 356n1989. It is primarily an expression for the ambition to increase the competitiveness by decreasing the lead-time and still improving quality and cost. The main methodology is to integrate the product development and the development of the design- and production processes. In this way Concurrent Engineering is a label for a development era of the manufacturing technology. To be successful Concurrent Engineering must be based on relevant theories, use efficient tools and be lead by dedicated management. Education and the ability for team work is essential for the success. Many companies are reporting good results from their use of Concurrent Engineering principles. More efficient software tools and manufacturing systems principles are being developed in research projects.


Surface Treatment Techniques by Laser Beam Machining
C.J. Heuvelman (1), W. Koenig (1), H.K. Toenshoff (1), J. Meijer (2), P.K. Kirner, M. Rund, M.F. Schneider, I. van Sprang  
STC E,  41/2/1992,  P.657
Keywords: Laser, Hardening, Remelting, Cladding, Alloying, Dispersing, Annealing
Abstract : Laser surface treatment involves a range of thermal and thermo-chemical processes which are applied on a wide range of products. An overview of processes and applications in the machine industry is given. Laser transformation hardening and remelting of cast iron are already established techniques. Improvements may be expected by on-line process control. Application of cladding and alloying will open the way for numerous new products but requires still further development. Results of CIRP co-operative work directed to the transferability of laboratory research to industry are included.


Tool Life and Tool Quality in Bulk Metal Forming
K. Lange (1), L. Cser (2), M. Geiger (2), J.A.G. Kals (1)  
STC F,  41/2/1992,  P.667
Keywords: Forming, Tool Life, Wear, Fracture, Design, Materials,
Abstract : Coatings, Simulation, Knowledge Based Systems, Monitoring Due to their intermediate position between machine and workpiece, tools represent the interface of the manufacturing system to the process. Near net shape production, new materials and techniques are the new challenges in metal forming and specially in tooling. A significant economical effect can be achieved through an increase in the service time of tool elements, as well as through proper tool management strategies. The greatest problem connected with the preliminary estimation of tool life is the enormous dispersion of tool lives for the same construction of tool. The uncertainty in estimating the expected service time of tools and thus the tooling costs/piece is caused by enormous variety and confluence of damaging factors, factory-specific character of tool life, stochastic phenomenon of tool failures. Front the confluence of aspects influencing the tool life it is clear, that there is no general recipe for increasing tool life and tool quality. Each of the influencing aspects contains some possibilities for increasing the service-time of tools. Paper shows some examples in tool design and tool manufacturing and points out, that a knowledge based approach can he the bridge between CA-techniques and human experience in prediction of expected tool life.


Modelling and Simulation of Grinding Processes
H.K. Toenshoff (1), J. Peters (1), T. Inasaki (1), T. Paul  
STC G,  41/2/1992,  P.677
Keywords: Grinding Process, Modelling, Simulation
Abstract : This paper describes the state-of-the-art in the modelling and simulation of grinding processes. The kinematics of the grinding process are characterised by a series of statistically irregular and separate engagements. Topography models are used to describe the structure of the grinding wheel, taking the quantities of motion and the geometric parameters into account. Chip formation is represented in chip thickness models. During the process of chip formation, energy is transformed. Additionally, forces are generated. In this paper, grinding energy models and force models will be presented. In conclusion, the kinematic and energetic processes are taken into consideration for temperature and surface integrity models as well as for models for describing the surface roughness of the workpiece. Different approaches to modelling will be compared. Furthermore, the benefits as well as the limits of model application and simulation will be discussed.


Advanced Controls for Feed Drives
Y. Koren (1), C.C. Lo  
STC M,  41/2/1992,  P.689
Keywords: Numerical Control, Machine Tool, Servo-Controller
Abstract : To achieve the high precision required in future contouring machining applications, accurate servo-controllers for the feed drives are needed. For this purpose conventional P controllers, which are utilized on many CNC systems, are not adequate, and more advanced control algorithms must be implemented. This paper summarizes existing servo-controllers for contouring applications and presents an evaluation of three basic types of controllers: feedback controller, feedforward controller, and cross-coupling controller. The evaluation of servo-controllers includes: (1) their abilities in eliminating different error sources and (2) their practical limitations in machine-tool control. The evaluation is supported by simulation and experimental results. In addition, some directions for future servo-control algorithms are also suggested.


Manufacturing Interfaces
F.J.A.M. Van Houten (2)  
STC O,  41/2/1992,  P.699
Keywords: Interfaces, CAD/CAM, Automation, Optimization, Production Control, CIM
Abstract : The paper identifies the changing needs and requirements with respect to the interfacing of manufacturing functions. It considers the manufacturing system, its components and their relationships from the technological and logistic point of view, against the background of concurrent engineering. Design- and manufacturing features are considered to become the basic elements for both internal and external communication between manufacturing functions. The increasing level of automation on the shop floor requires a much more formal communication at a high level of detail. Together with the increasing need for flexibility and the resulting decrease of batch sizes, this demands a much closer integration of production planning, process planning and shop floor control. Improvement of communication in combination with the use of feed-back data from the shop floor can substantially increase the effectiveness of the planning and consequently reduce the time pressure on the manufacturing system and its operators. Planning and control of auxiliary tasks and resources like tool and fixture preparation, machine set-up, material preparation, etc. increases due date reliability and quality and lowers production cost.


Vibration Isolation of precision Machine Tools and Instruments
D. De Bra (1)  
STC P,  41/2/1992,  P.711
Keywords: Vibration Isolation, Active Isolation
Abstract : Successful precision engineering is the balance of robustness of the machine and how benign the environment can be made through isolation to minimize the strains caused by vibration that compromise a machine's accuracy. This paper discusses principally the process of isolating a machine from the disturbances which come from the ground, air and utilities which serve it. Principles are reviewed and the intrinsic dependence on frequency established. Requirements are discussed and the hardware realizations currently available are reviewed. A number of examples of systems with unusually demanding requirements are given to illustrate the diverse nature of the solutions in practice. Some new developing areas are identified as the various topics are presented.