METHOD AND APPARATUS FOR REDUCING WRINKLE FORMATION IN DEEP DRAWING

摘要

A method and apparatus for deep drawing a product from a blank(5), in which, during deep drawing, the blank(5) is held near its edge by a downholder (8) against a die ring cooperating with the downholder (8), thereby preventing, at least reducing wrinkle formation in the blank, by adjusting, at the beginning of deep drawing, the downholder (8) such that a downholder (8) force exerted by the downholder (8) on the edge of the blank is relatively small, and by controlling, during the further course of the process, the downholder (8) on the basis of a predetermined thickness trend of the mentioned edge during deep drawing and/or a trend or critical value derived from this thickness trend.