Development of an Active Deep Drawing Tool Based on SMA High Load Actuators

Force distribution is one of the most important parameters in deep drawing processes and determines the quality of the formed parts. This paper presents a novel mechatronic approach to actively optimize the normal force distribution in deep drawing tools using high load actuators based on shape memory alloys (SMAs). Unlike competing technologies, SMA actuators offer small installation space, sufficient force, low costs, and a simple control. The concept is based on an array of SMA actuators which is integrated into the blank holder (BH) to actively adjust the force distribution during the deep drawing process. This can be used to respond to process variations and to automate the currently time-consuming and costly tryout phase when commissioning new tools. Experimental investigations with the active BH on a benchmark tool show the potential for increasing process reliability and stability.