Papers by Keyword: Valve Spring Retainer VSR

Abstract: New manufacturing processes for a valve-spring retainer (VSR) are proposed by replacing the initial solid billet for commercially available thick-walled pipes. The rigid-plastic FEM has been applied to simulate the conventional five-stage manufacturing process for VSR component. The existing process includes mainly backward extrusion and heading operations. A process design methodology is proposed and applied for the analysis. The process design criteria are the maximum force requirement within the available press limit, and the material saving by reducing the wastes from the process. As a result, several simulations of one-step process from selected stocks to the final product shape are performed for a possibly better process than the conventional one. Statistics among different processes are summarized and compared each other in terms of number of required operations for final product, forging load, material waste, number of individual die, process time, and even the possibility of fracture during service. Experiment also has been conducted to ensure that the proposed one-step process is safe operation without geometrical defects.

Abstract: The cold forging processes of automobile parts such as piston-pin, valve-spring retainer(VSR) and power-assisted steering part (PAS) are analyzed by the rigid-plastic finite element method. The results of the simulation on the piston-pin are summarized in terms of the strain distribution and load-stroke relationship. Based on the analysis on the current processes of VSR and PAS, the new novel processes for improving the conventional process sequences are designed. As a design criterion, the improved processes satisfy the new condition such as an initial billet size, the production time and the limit value of forming load and pressure etc. The present simulation results and the newly developed process gave rise to an improvement in manufacturing processes for cold-forged automobile parts. Furthermore, the numerical analysis for the processes in this study provides a new design concept for forming processes and a basis for the selection of forging equipments.