Monolithic molding method of light duty truck weldless axle case

Abstract

The invention relates to a monolithic molding method of a light duty truck weldless axle case. A weldless steel round pipe is used, first, early hole shrinkage is conducted to two ends of the weldless steel round pipe, two times of hydro-bugling are conducted to the middle of the weldless steel round pipe; and then, later stage hole shrinkage is conducted to the two ends of the weldless steel round pipe to obtain a performing pipe blank which is in an axial symmetry shape or close to an axial symmetry shape. A die left pressure head and a die right pressure head are used on a four-way hydraulic machine for sealing the ends of the performing pipe blank, liquid is injected into the four-way hydraulic machine, an upper die block, a lower die block, a front die block and a rear die block are used for integral pressing and forming on the performing pipe blank from the upper direction, the lower direction, the front direction and the rear direction, an axle case semi-finished product with a hemispherical rear oil cap and an additional front cap is obtained, and an axle case product is obtained by cutting the additional front cap. According to the monolithic molding method, the manufactured axle case is weldless, high in strength and stiffness, and high in material utilization rate. Comparing the used technique with a traditional hydro-bugling technique, the liquid pressure needed in manufacturing process is lowered by more than 60%, and the tonnage of forming devices is lowered by more than 50%.

Description

technical field [0001] The invention belongs to the field of automobile manufacturing, and in particular relates to an integral forming method for a non-welded axle housing of light and medium trucks. Background technique [0002] The axle housing of the automobile drive axle is one of the main load-bearing components of the automobile. It is the assembly base of the final reducer, differential, and half shaft. And through the suspension to the frame or body. Its performance directly affects the safety and reliability of the transport vehicle, it should have sufficient strength and rigidity, and it is required to reduce the mass as much as possible to improve the ride comfort of the vehicle. Light and medium-duty truck axle housings are pipes with complex shapes. The two ends are small and the middle is large. The ends are round and the inside of the end is rectangular. At present, the axle housings of light and medium-sized trucks are mainly manufactured by stamping and w...

AI Technical Summary

Problems solved by technology

[0007] (1) The axial force effect is not good when the tube blank is hydraulically bulging, and the wall thickness reduction is large

The diameter of both sides of the middle part of the tube blank before hydraulic bulging has been reduced to the required size, and the size difference between the end part and the middle part is large. Big

For light and medium-duty trucks, the end of the tube blank is round after diameter reduction and the inner side is rectangular, and the effect of applying axial force during hydraulic bulging is even worse

[0008] (2) It is difficult to operate when the hydraulic bulging tube blank is pressed and formed

The front module and the rear module of the pressing mold are fixedly connected by bolts and cannot be moved. In actual production, it will be difficult to unload the material before pressing, and it will be difficult to release the semi-finished axle housing after pressing and easily scratch the outer surface.

[0009] (3) The performance of the parts is not easy to control

If stress-relief annealing is performed on the reduced-diameter parts of the axle housing semi-finished products obtained after pressing, the work hardening will be completely eliminated, and the static bending stiffness and bending fatigue life of the parts will be significantly reduced; if stress-relief annealing is not performed, the residual Excessive stress can also affect performance

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