A New Forming Strategy to Realise Parts Designed for Deep-drawing by Incremental CNC Sheet Forming

摘要

The work detailed in this paper focuses on a new forming strategy for the CNC incremental sheet forming (ISF) process that is appropriate to form steep flanges, e.g. for parts designed for deep-drawing. When parts are designed for deep-drawing, they usually contain steep or rectangular side walls that cannot be manufactured using the standard ISF strategies. Unlike prior approaches to obtain steep flanges through ISF, the present method achieves a rough approximation to the final part already in the preforming stage. This can be accomplished without excessive sheet thinning due to sheet bending and stretching at this stage. As a consequence, additional material can be used for the finishing stages, thus yielding a final part with largely reduced thinning. After basic studies on a simple benchmark problem, the new bending/stretching strategy is tested with an industrially applied part that is usually produced by deep-drawing. Finally, the ISF workpiece is evaluated against the deep-drawn component with respect to sheet thickness and geometric accuracy.