Copper terminal products are made of red copper, which has low yield strength, good plasticity and axial symmetry, and is suitable for cold extrusion. Cold extrusion of pipe fittings can be divided into two types: cold extrusion with mandrel and cold extrusion without mandrel. The mandrel can limit the inner diameter of the formed pipe fittings, and the die structure is complex, which is mainly used for workpieces that require the wall thickness of the pipe fittings to be constant or thin. The mandrel-free forming process not only has axial elongation, but also thickens the wall thickness, which is suitable for producing pipe fittings with less strict requirements on inner diameter and wall thickness. The coreless cold extrusion die has no mandrel, simple structure, easy manufacture, convenient operation and high production efficiency. A large cross-sectional reduction rate can be obtained by one-time extrusion, and the deformation times can be minimized. In view of the lack of strict requirements on the inner diameter and wall thickness of the parts, the cold extrusion process without mandrel was finally selected for the project.

The specific process flow is as follows:

The terminal cold extrusion die adopts combined structure. When working, first lift the upper die, and then put the blank into the lower die vertically. When the upper die is pressed, it returns immediately after pressing, and the ejector ejects the workpiece from the lower die to obtain the finished product, thus completing a working cycle.