New approach on controlling strain distribution manufactured in sheet metal components during deep drawing process

The production of irregularly shaped deep drawing parts with high quality requirements, which are common in today's automotive car body production, consistently challenges production processes. The more and more complex requirements of design, light weight construction and crashworthiness lead to a more narrow process window for deep drawing production and thus the manufacturing process robustness is decreasing and hence the necessary use of high strength steels. Modern metal forming technologies deals with these challenges using highly sophisticated methods to control the material flow or adjustable process parameters by use of controllable machine or tool axis. Multiple control loop methods in deep drawing technology have been investigated during the recent two decades in order measure and to control the material flow in deep drawing processes. These methods only allow any control intervention between two strokes which itself is regarded as a simple open loop control system because a none process variable is a feed back to the controller. The method that was developed at the Institute for Metal Forming Technology (IFU) at the University of Stuttgart allows any control intervention during the deep drawing stroke for every blank holder design.