Stretching forming process of casing pipe for automobile chassis

Abstract

The invention discloses a stretching forming process of a sleeve for an automobile chassis. From a QSTE420TM cold-formed hot-rolled automobile structural steel plates to casing pipe finished products, the method comprises the following process steps of material selection and blanking, stretch forming, shaping, trimming, flanging and rotary cutting. According to the method, by reasonably increasing stretching process passes and combining accurate calculation and repeated experiments, the stretching forming process of the casing pipe for the automobile chassis is finally determined, bad products such as stretching cracks and indentations are effectively avoided, and the procedure of trimming inner circumferential wall of a pipe body under condition of stretching cracks and indentations in prior art is reduced; after the final shaping link in the conventional process is converted into the stretching forming step, the overall semi-finished product size and specification requirements are adjusted in advance, and therefore subsequent steps and processes can be directly completed conveniently; and an upper opening of the casing pipe is achieved in a rotary cutting process overall cutting mode, so that the problems that due to the fact that the upper opening formed through punching needs to be flanged, the thinning rate change is aggravated, and the material performance is reduced are completely and effectively avoided.

Description

technical field [0001] The invention relates to the technical field of molding technology of automobile parts, in particular to a stretching molding technology for casings used in automobile chassis. Background technique [0002] Today's car OEMs have higher and higher requirements for vehicle weight reduction and improvement of vehicle strength, especially for car chassis parts, which are mainly reflected in the reduction of material thickness, material strength, and modeling complexity. Among them, the casing used for car chassis is an important part in the car, because of its high tensile height (h=65~70mm), high material strength requirements (tensile strength>540MPa), and high material thinning rate requirements. Low (<15%), small diameter (<75mm) requirements, most of the existing sleeve parts are processed by the buckling forming process or cold heading of metal tubes, but the buckling forming process makes the sleeve The components not only have low strengt...

AI Technical Summary

Problems solved by technology

[0002] Today's car OEMs have higher and higher requirements for vehicle weight reduction and improvement of vehicle strength, especially for car chassis parts, which are mainly reflected in the reduction of material thickness of parts, the improvement of material strength, and the increase of modeling complexity. Among them, the casing used for car chassis is an important part in the car, because of its high tensile height (h=65~70mm), high material strength requirements (tensile strength>540MPa), and high material thinning rate requirements. Low (<15%), small diameter (<75mm) requirements, most of the existing casing parts are processed by buckling forming process or cold heading of metal tubes, but the buckling forming process makes casing The components not only have low strength and poor cylindricity, but also the fastening parts and the buckle grooves are easy to fall off during flanging, and the scrap rate is high. Due to the limitation of the material properties of the metal pipe, the cold heading of the metal pipe is subject to restrictions when forming the flange flanging. It is easy to break and scrap due to stress, so it is not suitable for the current automobile production and use requirements. It is also difficult to manufacture the part by cold stamping and stretching of high-strength steel plate. The opening is realized by punching the end face, and the end of the punching hole can only be flanged outward again, which greatly reduces the overall coaxiality accuracy of the inner diameter, and the thinning rate cannot meet the standard, and there is a problem of inner wall cracking caused by stretching Stretch marks, stress and easy cracking and scrapping, etc., instead increase production costs and reduce production efficiency

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