METHOD AND DEVICE FOR DEEP-DRAWING LEAF MATERIALS WITH A DEFORMABLE STAMP UNDER A SUBMERSIBLE PISTON.

摘要

Method for pressing sheet material, in particular sheet metal, on a press by way of a cushion (12) composed of an elastic material, comprising disposing a sheet blank (20) to be formed on a support whose peripheral part forms a lower blank holder (2) and whose central part constitutes a die (3), applying, under the action of an outer slide, an upper blank holder (9) on the peripheral portion of the sheet blank (20), then applying a punch (11) under the effect of a ram, the method further comprising, in the course of a first step, applying, under the action of the ram, the cushion (12) on the sheet blank (20) for preforming the sheet blank in such manner as to impart thereto a surface area substantially equal to the surface area of the finished part to be obtained, then, in the course of a second step, continuing, under the action of the ram, the descent of the elastic cushion (12) and simultaneously displacing all or a part of the bottom of the die (3) for achieving the final shaping of the part.