Method forming a drawn container and a container produced by this method

Abstract

The invention relates to a method for drawing a wrinkle-free thin-walled cup from a sheet blank, using a die formed as a draw ring, a holddown that holds the blank material against the draw ring, and a drawing punch, which pushes the blank into the opening of the draw ring, wherein the blank material that flows from the slot between the draw ring and the holddown is formed by drawing in an initial zone of deformation which surrounds the punch, and flows into the opening of the draw ring over the latter's inner edge which is adjacent to the area of the holddown. According to the invention, in order to draw a conical cup of sheet metal, preferably of sheet steel, having a peripheral wall which forms with respect to the center axis of the cup an angle sheet is smaller than 60.degree. and preferably an angle of 3.degree., utilizing a rigid construction of both the draw ring end of the holddown and the draw punch, the holddown subjects the blank material to a force that amounts to a multiple of the force of the draw punch, in such manner that the material which flows from the initial zone of deformation into the opening of the draw ring is formed in a second conic zone of deformation by means of stretch forming in a free cavity formed between the draw punch and draw ring.

Dependencies are inferred from the claim text.