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.
Keywords: deep drawing, closed-loop control, follow-up control, robust process, part wall stress