Method and drawing tool for deep drawing blanks of sheet metal material to flangeless moldings

摘要

A method of deep-drawing blanks stamped from sheet metal material coated or sheet-coated, such as steel or aluminum, into flangeless blanks, the blanks being formed around a draw mandrel by means of a pull cup of a puller to a cup-shaped member having a flangeless cylindrical rim be deformed and during the formation of the edge of the blanks by means of a pleat holder on the drawing bell opposite side of the edge a predetermined spring force is applied, and shortly before the end of the drawing operation, the spring force is reduced spontaneously at the pleat holder substantially to zero.