Improving in performance of cold extrusion of deep bushings using specialized presses

Abstract

The design of specialized press applicable to extrude parts such as deep cups and bushings in which creating actively directed contact friction stresses at the boundary of the workpiece with the matrix, which reduces the pressure on the punch and increases its fatigue resistance is presented. The role of the non-uniformity of contact friction, which leads to different thickness of the products wall, is explained. It is experimentally proved that there is no difference of wall thicknesses when the two-channel flow of the extruded metal is happens. The results of the study of specific forces and product shaping during two-channel extrusion of parts in the form of coaxial double bushings are presented. For such parts, extrusion with actively directed contact friction stresses between the workpiece and the tool is studied. The rational combination of two bushings of different sizes into single stamped part, carried out in order to increase the productivity of stamping, is considered.