EXTRUSION METHOD Russian patent published in 1994 - IPC

FIELD: metal working. SUBSTANCE: extrusion is carried out in container 1 through flat die 2 by means of two concentric plungers. In the course of extrusion of workpiece 5, when the length of press residue equals to the height of the center of plastic deformation, deformation of the part of the press residue under the central plunger is stopped, and deformation of the periphery of the press residue is continued by the peripheral plunger to engagement with die end. This terminates extrusion of the central part of the press residue through the hole in the die. EFFECT: enhanced efficiency of extrusion process. 4 dwg