Hydraulically assisted mechanical extrusion press

摘要

Mechanical extrusion press for billet piercing and tube extrusion comprises an upper punch and a mandrel both of which are actuated by the cam shaft, but where the action of the punch is reinforced by the pressure exerted by at least one hydraulic cylinder which is effective near the bottom dead centre of the cam movement at the end of the working stroke. By this method the speed of the mechanical press exemplified by the fast return movement of mandrel and punch is combined with the greatly superior maximum pressure capability of a slow hydraulic pressing system.