Hydraulic press four column Cold extrusion hydraulic press machine

Cold Extrusion is to force the plastic flow of gold chips, through the gap between the punch and the die or the exit of the die, to create a hollow or a part with a smaller section than the blank. If the blank is extruded without heating, it is called cold extrusion. Cold extrusion is one of the chipless and less chip parts processing technology, so it is an advanced technology method in the plastic processing of gold chips. If the blank is heated to a temperature below the recrystallization temperature for extrusion, it is called warm extrusion. Warm extrusion still has the advantage of less swarf.

Features

1.At present, the general dimensional accuracy of cold extrusions developed in China can reach 8-9 grades. If the ideal lubrication is used (refers to the pure aluminum and copper parts), it is second only to the surface of fine polishing. Therefore, the parts produced by the cold extrusion method generally do not need to be reprocessed, and only a small number of parts need to be finished (ground).

2. The utilization of cold extruded parts can usually reach more than 80%. For example, the utilization rate of the piston cutting and cutting processing materials of the Liberal brand automobile is 43.3%, while the material utilization rate is increased to 92% when the cold extrusion is used; and if the universal joint bearing sleeve is changed to cold extrusion, the material utilization rate is from the past. 27.8% to 64%. It can be seen that using cold extrusion to produce mechanical parts can save a lot of steel and non-ferrous metal materials.

3.Because cold extrusion adopts the cold working strengthening characteristic of metal material cold deformation, that is, the metal blank is in a three-direction compressive stress state during the extrusion process, and the material structure is dense after deformation and has a continuous fiber flow direction, so the strength of the workpiece is relatively large. improve. In this way, low-strength materials can be used instead of high-strength materials. For example, in the past, 20Cr steel was used to manufacture Liberated brand piston pins through cutting. Now, No.20 steel has been used to make cold-extrusion piston pins. After performance determination of various indicators, cold extrusion method is higher than cutting processing method to manufacture piston pins.