Abstract
This paper deals with an automated computer-aided process planning and die design system with which designer can determine operation sequences even after only a little experience in process planning and die design of multi former-bolt products by multistsage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules, which are input and shape treatment, production feasibility check, process planning, and die design modules. The process planning and die design module considers several factors, such as the complexities of perform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. It can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution and the level of the required forming loads at the last forming step by controlling the forming ratios. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The stanardization of die parts for multi former-bolt products requiring a cold forging process is described. The strip layout and die layout drawings, which are automatically generated by formulization and quantification of experimental technology, will minimize trial and error and reduce the period for developing new products. The system developed makes it possible to design and manufacture multi former-bolt products more efficiently.
