A thin-walled metal tube stretch bending method

Abstract

The invention discloses a thin-wall metal pipe stretch bending method. The thin-wall metal pipe stretch bending method comprises the step of conducting stretch bending on a pipe blank through a stretch bending device. The stretch bending device comprises a die, shaping rolls and chucks. The shaping rolls are arranged on the two sides of the die and used for auxiliary shaping. In the stretch bending process, the shaping rolls rotate in the direction opposite to the direction of pull force borne by the pipe blank. Through the thin-wall metal pipe stretch bending method, in the stretch bending forming process, the stretch amount of the inner side of a metal pipe can be increased, and the stretch amount of the outer side of a metal pipe can be reduced; the difference between the inside and outside stretch amounts generated in the stretch bending process is balanced; and the risk of unstability of the pipe is reduced.

Description

technical field [0001] The invention belongs to the technical field of metal processing and forming, and in particular relates to a pipe bending deformation process, in particular to a new stretch bending forming process of thin-walled metal pipes. Background technique [0002] As we all know, stretch bending is an important method of metal pipe bending forming process. However, due to the deformation characteristics of metal, when the thin-walled metal pipe is stretch-bent with a small bending radius, it often occurs that the inner side of the bend is wrinkled and the outer side is cracked. The main reason is that the deformation of the inner and outer sides of the pipe is quite different. . [0003] At present, the clamping fixture commonly used in the stretch bending forming process of metal pipes, the main working principle is to clamp the metal pipes evenly along the circumference, so as to apply tensile stress in the radial direction, and then bend them according to t...

AI Technical Summary

Problems solved by technology

During the whole process, the tensile stress is always consistent with the axial direction of the metal pipe and perpendicular to the circumferential direction, that is to say, the tensile stress received by each place of the pipe wall of the metal pipe is basically the same, but, due to the The deformation radii of the inner metal and the outer metal far away from the mold are different, so that the total length of the inner metal after bending will be smaller than the total length of the deformation of the outer metal, which results in the compression length of the inner tube wall metal close to the mold, and because the thin-walled metal is easy to lose Stable, so it is prone to wrinkling, and the outer metal needs to be extended to cause excessive stretching, resulting in breakage of the tube wall

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