Extrusion mold for soft copper bar

Abstract

The invention relates to an extrusion mold for soft copper bars. The extrusion mold includes a molding cavity; the molding cavity comprises an inlet wire cavity, a sizing cavity and an outlet wire cavity, which are communicated in order. The axes of the inlet wire cavity, the sizing cavity and the outlet wire cavity are in the same straight line; along the wire outlet direction, the inlet wire cavity is in necking arrangement, the outlet wire cavity is in flaring arrangement, and the sizing cavity is in plain end arrangement. The invention has the following advantages: 1) the three regions extend the molding time of copper rod in the mold, so that the copper rod is kept at a higher temperature in a long time to realize better softening effect; and 2) the inlet wire cavity forms a buffer zone in the liquefaction softening process of the copper rod, and the diameter slowly changes, in order to ensure gentle stress on the copper rod during extrusion; and the level of the force slowly changes, thus ensuring the quality of the copper bar product.

Description

technical field [0001] The invention relates to an extrusion die for producing soft copper bars, which belongs to the technical field of dies. Background technique [0002] For the rotor guide bars of large hydroelectric generators, wind turbines, and other special motors, due to the need for subsequent processing such as bending and shaping, wrapping and lower grooves, etc., general motor manufacturers require softer, less than 120 N / mm2 stiffness requirements, springback angle It is required to be below 3°. At present, there are two methods for domestic production of rotor guide bar copper bars. One is the traditional production method of cold drawing + annealing. This method has great limitations, and the length is limited (depending on the length of the broaching machine). There are many waste materials and a large waste; during annealing, the copper bars are easy to stick together, and the surface quality of the copper bars is seriously affected; there are many process...

AI Technical Summary

Problems solved by technology

At present, there are two methods for domestic production of rotor guide bar copper bars. One is the traditional production method of cold drawing + annealing. This method has great limitations, and the length is limited (depending on the length of the broaching machine). There are a lot of waste materials and a lot of waste; during annealing, the copper bars are easy to stick together, and the surface quality of the copper bars is seriously affected; there are many processes, large energy consumption, and high production costs

The second is the continuous extrusion production method, which effectively overcomes the above limitations, but generally has a relatively large rigidity, generally around 150 N / mm2, and the copper bar is relatively hard, which is not conducive to subsequent processing

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