Molding process for precision shaped pipe and cold drawing mold thereof

Abstract

The invention discloses a molding process for a precision shaped pipe and a cold drawing mold thereof. The molding process comprises the following steps of: 1) annealing a round blank pipe; 2) washing the annealed round blank pipe with acid and phosphating the acid-washed pipe; 3) pinching, namely extruding one end of the round blank pipe to form a necking; 4) performing cold drawing molding, namely inserting the pinched round blank pipe into a drawing rod, starting a core rod feeding device, feeding a pinched position of the round blank pipe into a shaped hole on an external drawing mold by the drawing rod, clamping the pinched position by a clamping jaw of a drawing machine and pulling the round blank pipe across a shaped annular mold hole formed by combining the external drawing mold and a shaped core rod; and 5) removing tips. The cold drawing mold comprises the external drawing mold provided with the shaped hole and the matching shaped drawing core rod aligned in the shaped hole,wherein the external drawing mold comprises an outer sleeve and a mold core; and the mold core is sequentially provided with a shrunken conical hole and the shaped hole along a drawing direction. Thecold drawing mold is molded by a drawing procedure once, and a processed product has the advantages of high accuracy and good appearance quality. The molding process has a few working procedures and the production efficiency is greatly enhanced.

Description

technical field [0001] The invention relates to a forming process for processing precision special-shaped pipes and a cold drawing die thereof. Background technique [0002] Such as figure 1 and figure 2 The octagonal special-shaped pipe 6 shown is a blank pipe for auto parts, and has high requirements for the accuracy of the internal and external dimensions, and the difference between the wall thicknesses A1-A8 of the eight sides is less than 0.15mm; The size of the inner hole cannot be satisfied; the production process is to weld the strip into a round tube, anneal, pickle, phosphate, and then, such as image 3 As shown, after several times of sizing rolling, the circular tube 7 is rolled into special-shaped tubes with arcs R1, R2, and R3 each time, and R1<R2<R3. The straight edge is made, so that the outer dimension of the special-shaped tube 8 rolled out by the roll can be controlled, but the inner hole dimension cannot be controlled, and it cannot be guarantee...

AI Technical Summary

Problems solved by technology

[0002] like figure 1 and figure 2 The octagonal special-shaped pipe 6 shown is a blank pipe for auto parts, and has high requirements for the accuracy of the internal and external dimensions, and the difference between the wall thicknesses A1-A8 of the eight sides is less than 0.15mm; The size of the inner hole cannot be satisfied; the production process is to weld the strip into a round tube, anneal, pickle, phosphate, and then, such as image 3 As shown, after several times of sizing rolling, the circular tube 7 is rolled into special-shaped tubes with arcs R1, R2, and R3 each time, and R1figure 1 The accuracy requirements in the medium, and the process is numerous, the production efficiency is low

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