Thin-wall rectangular-cross-section pipe bending method

Abstract

The invention provides a thin-wall rectangular-cross-section pipe bending method. The thin-wall rectangular-cross-section pipe bending method comprises the following steps that (1), a conventional pipe bending method is adopted, a thin-wall rectangular-cross-section pipe blank is bent in advance, and a pipe pre-bending piece with folds is obtained; (2), a corresponding shaping die is selected and installed on a pressure bulging pressing machine; (3), the pre-bending piece is installed to the shaping die and is connected with a high-pressure-oil oil way; (4), a high-pressure oil pump is started to eliminate air in the pipe pre-bending pipe, an exhausting hole is sealed, a pipe is filled with oil liquid; (5), pressure is exerted for bulging till the folds of the pipe pre-bending piece are eliminated; (6), pressure is relived, oil is discharged, and die sinking is performed. By means of the method, two types of process technologies are comprehensively utilized, on one hand, the advantage that the conventional bent pipe is easy to form is utilized, the blank is bent in advance in the first place, then the inner-high-pressure forming technology is utilized, high pressure is exerted on the interior of the pipe so that the pipe can be bulged and attached to the die to eliminate the folds, disadvantages of the conventional bent pipe are overcome, a thin-wall rectangular-cross-section pipe bending piece is formed accurately, forming quality and precision are high, the surface is neat and smooth, and the appearance is attractive.

Description

technical field [0001] The invention belongs to the technical field of mechanical processing, and relates to a pipe processing method, in particular to a method for bending thin-walled rectangular cross-section pipes. Background technique [0002] Pipe bending forming is an important branch of pipe plastic forming. As the most typical and important type of pipe bending products with rectangular cross section, it has the characteristics of uniform force, stable structure and easy installation. It has been widely used in various industry. [0003] The common pipe bending forming process is mainly divided into two categories: one is to rely entirely on the shape of the mold part, and the bending process is carried out by fitting the pipe and the surface of the mold, such as stretch bending, press bending, and winding forming; the other is Relying on the relative movement between the mold and the pipe, the plastic processing is completed through the instantaneous loading and un...

AI Technical Summary

Problems solved by technology

[0004] Due to the thin and hollow walls of the rectangular section tube, the inner wall of the rectangular tube billet is compressed and deformed in the axial direction during the bending process, and is limited by the mold in the width direction, so the material will gradually accumulate in the thickness direction. When the inner wall Wrinkling occurs when the material cannot continue to flow along the axial direction, which not only affects the appearance of the formed part, but also affects the forming accuracy

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