Improving Part Quality During Deep Drawing by Modifying Friction Conditions via the Ram Movement
摘要
This article presents a method for optimising the friction conditions during deep drawing processes, enabling part quality to be improved. The optimisation is based on the speed dependent modification of friction coefficients by adjusting the ram motion. Here, the intention is to modify the ram motion profile depending on the part geometry to control the friction-related sheet retention force and thus increase the drawing depth. To this end, fundamental experimental investigations are carried out to record the friction coefficient of DP500, revealing a high dependence on drawing speed. Next, a forming simulation is performed with the determined friction coefficients, considering a conventional sinusoidal profile. Subsequently, the drawing depth is divided into several steps and the friction coefficient for each of these steps is determined with regard to highest possible drawing depth through stochastic simulations. Finally, the friction coefficients are correlated with corresponding forming speeds to derive the appropriate ram profile.