The process sequence design of a power-assisted steering part

Conventional and new forging processes of a power-steering worm blank are a nalyzed by the rigid-plastic finite element method. The conventional proces s contains three stages such as indentation, extrusion and upsetting, and w as designed by a forming equipment expert. Process conditions such as reduc tion in area, extrusion angle and upsetting ratio are considered to prevent internal or geometrical defects. The results of simulation of the conventi onal forging process are summarized in terms of deformation patterns, load- stroke relationships and die pressures for each forming operation. Based on the simulation results of the current three-stage process, a power-steerin g worm blank forging process for improving the conventional process sequenc e is designed. The die pressures and forming loads of the proposed process are within the limit value, which was set by experts and the proposed proce ss is found to be suitable for manufacturing the power-steering worm blank. (C) 2001 Elsevier Science B.V. All rights reserved.