Annealing-free driving bridge shell hydraulic forming method using high-strength welded pipe

Abstract

The invention discloses an annealing-free driving bridge shell hydraulic forming method using a high-strength welded pipe. A welded pipe blank is subjected to two times of end portion pushing and diameter reducing process, two times of middle part hydraulic bulging process and one liquid filling and pressing and shaping process to prepare a bridge shell. The first hydraulic bulging process adoptsa sliding bulging mold with a back pressure punch, the bulging volume is up to 1.8 times of pipe expansion rate, the thinning rate is not more than 10%, and the middle part of the pipe blank after forming is an axisymmetric cylinder. The second hydraulic bulging process adopts a sliding bulging mold with a fixed mold, the middle part of the pipe blank after forming is a non-axisymmetric cylinder shaped part, and the thinning rate is not more than 10%. The third liquid filling and pressing and shaping process prepares the preformed pipe blank into a bridge shell pipe fitting with flat front part and spherical rear part. A bridge shell product is prepared after cutting off an additional front cover. The annealing-free driving bridge shell hydraulic forming method using the high-strength welded pipe retains the advantages of light weight, high strength and high material utilization rate of the bridge shell hydraulic forming process, has the characteristics of simplified forming process, high production efficiency and the like, and can achieve the purpose of replacing the traditional bridge shell stamping and welding process.

Description

technical field [0001] The invention belongs to the field of auto parts manufacturing, and relates to a hydroforming method for drive axle housing parts. Background technique [0002] In recent years, in the automotive field, hydroforming, as one of the lightweight methods, tends to spread to the drive axle housing. Since hydroforming can make the thickness distribution of the axle housing change, even under the condition of equal weight, the hydraulic forming axle housing has higher rigidity and longer fatigue life than the stamped and welded axle housing. [0003] Although there have been forming technologies related to the hydroforming of automobile drive axle housings, such as the integral forming method of CN103084460 B light and medium-duty trucks without welded seam housings, the composite bulging method of utilizing shrinking diameter and sliding hydraulic bulging to carry out axle housing forming has been described. Shape process method. The axle housing manufactu...

AI Technical Summary

Problems solved by technology

This limits the application of this process on drive axles with high load-bearing capacity requirements: medium and light vehicle drive axle housings usually need to be manufactured with 350MPa high-strength steel, and the elongation of high-strength steel is generally not more than 25%.

[0006] (2) The second back pressure forming and the third internal high pressure shaping require a large change in the shape of the product, and there is a bottleneck problem that requires higher internal pressure forming

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