Knowledge-Based Process Planning in Axisymmetrical Cold Forged Products Using Adjustment of Stepped Cylinder Method

Abstract

In this research investigation, we have proposed a cold forging process planning reproduced the expert engineer's thinking process faithfully, and have also developed a practical knowledge-based system for axisymmetrical cold forged products. In this system, a forged product is represented as an aggregation of the forming patterns consisting of cylindrical pillar parts. The basic principle of the inference is the adjustment of the diameters of neighboring stepped cylinders so that they are all the same. Deformable process plans are generated by using expert knowledge regarding working limits and metal flow. The system can eliminate useless plans by using the knowledge of how to combine plural forming patterns in one process. Moreover, it can evaluate process plans by considering forming load, effective strain in the product and select an optimal one by using FEM simulation. We applied the system to actual forged products, and appropriate results were obtained including a practical process plan. The knowledge using the basic principle is widely applicable to various axisymmetrical forged product shapes.