Numerical Simulation Of Muti-Step Cold Forging Process For A Camber Bolt

Camber bolt is a part used to adjust wheel alignment at rear suspension system of vehicle for maintaining driving balanced. As a fastening piece, it generally manufactured by cold forging process. With a view to its complicated structure and Materal hardness, muti-step forging is needed for preforming, bat many problems would be apeared in the serous forging, such as the unexpected metal flow, breack, surface oxidation at high temperature, lubricating failure and so on, therefor, the design of cold forgng process and its temperature in forging are important factors for the quality of a camber bolt.In order to obtain an expected one of AISI4140steel camber bolt with a specifaction, the design of cold forging process has been made, the total forging process includs5steps, and they have been numerical simulated using the method of rigid-plastic finite element analysis, which provided the rules of forming for the whole process of the camber bolt, and then given a ference of modifying for the dies design. Finally, the simulated pieces and the experimental one have been compared to verify the correctness of the process design.After that, using the thermol-coupled finite element analysis, temperature distributions of the cold forging process has also been numerical simulated, Firstly, the material mechanical energy to heat conversion rate has been determined and the temperature distributions throughout the forging process of a camber bolt has been analyzed. Furthermore, the temperature and the load that concerned with different punch speeds have also been studied. Finally, the experimental proof has been presented for the accuracy of this method.Though the numerical simulation and experiment, some conclusions have been drawn as flows: 1. The vital point of the process design was that the metal flow lines should be rounded in the direction of the eccentric.2. Through determining the material mechanical energy to heat conversation rate, the temperature distributions of the cold forging process of the camber bolt was accurately calculated.3. Within a certain punch speed, the workpiece temperature increases linearly with the increased punch speed, while the load decreases a little with increased temperature and punch speed, but the load becomes to be change little when the punch reaches a certain speed.