Four-point-bending over-bending straightening process method for large shaft tube parts

Abstract

The invention relates to a four-point-bending over-bending straightening process method for large shaft tube parts and is characterized in that two lower dies are arranged on a workbench of a forming press, two upper dies are connected to a beam of the forming press, and a shaft tube part is placed among the two upper dies and the two lower dies under the beam of the forming press; the distance between the two lower dies is determined by calculation, the distance between the two upper dies is determined by calculation, and the positions of the upper dies above the lower dies, and the rolling reduction of the two upper dies are determined by calculation; the distance between the two upper dies and the distance between the two lower dies are respectively adjusted to the expected position; then, the shaft tube part is pressed, after the pressing is finished, the upper dies move upwards along with the beam of the forming press; and whether the straightness of the shaft tube part meets requirements or not is inspected, if not, the steps are repeatedly carried out until the requirements are met. The four-point-bending over-bending straightening process method for the large shaft tube parts has the advantages that the finally-finished shaft tube part is deformed uniformly and realizes smooth transition, and the straightness of the parts better meets the requirements; residual stress existing in the parts is smaller, and the distribution of the residual stress is uniform; and meanwhile, the forming cycle is shortened, and the working efficiency is improved.

Description

technical field [0001] The invention belongs to a mechanical processing method in the field of machinery, and in particular relates to a four-point bending and over-bending straightening process for large-scale shaft and tube parts. Background technique [0002] Shaft tube parts are important parts widely used in mechanical products. Due to heat treatment and other processes, the shaft center line is bent and deformed, which may easily cause the straightness of the parts to fail to meet the use requirements. At present, the straightness quality of the parts can be guaranteed by one or more three-point cold straightening processes. The main forming method is: the shaft tube parts are sent to the forming press table, and placed on an upper die and two lower dies. Between the dies; then, the upper die moves down to press the part into the opposite direction of curvature; then the upper die moves up to measure whether the straightness of the part meets the requirements, if not, ...

AI Technical Summary

Problems solved by technology

Since the basic mechanical model of its straightening is a three-point bending mechanical model, the main disadvantages of this process are as follows: 1. Because the deformation area is mainly concentrated in the area near the pressure point, the local deformation is serious, resulting in large and distributed residual stress. Uneven, the quality of the parts is not high; 2. The straightening efficiency is low and the labor intensity is high

Images