Outer mould of inequilateral lining core mould of rectangular special-shaped steel tube

Abstract

The invention discloses an outer mould of an inequilateral lining core mould of a rectangular special-shaped steel tube. Relevant parameters of an inlet segment of the outer mould can be quantized, and the outer mould comprises an insert bush and a mould core arranged in the insert bush, and a draw hole penetrating the mould core is formed in the mould core and comprises the inlet segment and a sizing segment; the sizing segment comprises a pair of wide straight faces, a pair of narrow straight faces and four corner circular-arc faces, wherein the distance between the wide straight faces is A, the distance between the narrow straight faces is B, and the curvature radius of the corner circular-arc faces is R1; the inlet segment comprises a pair of wide guide-in inclined surfaces, a pair of narrow guide-in inclined surfaces and four inlet corner curved faces; the distance between the outer edge lines of the wide guide-in inclined faces is the formula (please see the formula in the specification), wherein k1 is larger than or equal to 1.15 and smaller than or equal to 1.25, k2 is larger than or equal to 0.5 and smaller than or equal to 0.8, and k3 is larger than or equal to 0.5 and smaller than or equal to 0.8; and the distance between the outer edge lines of the pair of narrow guide-in inclined faces is L2 equal to B+k4(L1-A), wherein k4 IS larger than or equal to 0.9 and smaller than or equal to 1.0. The outer mould is used for drawing round steel tube blanks to the rectangular steel tube.

Description

technical field [0001] The invention relates to a forming and drawing die in the technical field of metal plastic processing, in particular to a forming and drawing die for drawing a round steel pipe into a rectangular special-shaped steel pipe. Background technique [0002] The drawing die is an important tooling part in the production of cold-drawn steel pipes, and has been widely used in the production process of steel pipe diameter reduction and / or deformation. The steel pipe is cold drawn and formed by using a drawing die, which has the characteristics of high material utilization rate, low energy consumption, excellent product performance, high production efficiency and low cost. Among the drawing dies, according to the different cross-sectional shapes of the drawn pipes, they can be divided into oval drawing dies and special-shaped drawing dies. ); Among them, the special-shaped drawing die is divided into empty drawing die (referred to as empty drawing die) and lini...

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Problems solved by technology

[0003] As we all know, if the opening size of the outer mold and the length of the entrance section are set unreasonably, the contact area between the steel pipe and the mold will change accordingly, and the longitudinal and lateral flow of the metal will be unbalanced, which will lead to The quality of the rectangular tube is poor, and the main surface has defects such as poor straightness (with varying degrees of bending), uneven wall thickness, uneven rounded corners, unstable dimensions, and uneven surfaces, and even more so during the drawing process. Steel pipe breakage and cracking

[0004] At present, there is no uniform design standard for the outer mold of the special-shaped steel pipe lining mandrel. The opening size and length of the inlet section are set based on experience. For each type of rectangular tube, when designing the outer mold, It takes repeated tests, improvements, and retests to get an ideal outer mold, which not only prolongs the processing cycle of the outer mold, but also increases the production cost

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