A kind of friction welding aluminum alloy transmission shaft and its processing method

Abstract

The invention discloses a friction welding aluminum alloy transmission shaft and a processing method thereof. The transmission shaft comprises a shaft tube body, a shaft fork is welded at one end of the shaft tube body, and a spline sleeve is welded at the other end; The outer wall of one end is surrounded by a first thickened part, and the outer wall of the other end of the shaft tube body facing the spline sleeve is surrounded by a second thickened part. The inner wall of one end of the shaft tube body is surrounded by a first inner flange, and the inner wall of the other end of the shaft tube body is surrounded by a second inner flange; the inner wall of the welded end of the shaft fork is surrounded by a shaft fork fixed with the first inner flange Inner flanging, the inner wall of the welding end of the spline sleeve is surrounded by an inner flanging of the spline sleeve fixed to the second inner flanging. The outer walls of both ends of the shaft tube body of the present invention are provided with a first thickened part and a second thickened part, which can improve the torsional section coefficient, reduce the working stress of the welded joint, and compensate for the decrease in weld strength caused by friction welding. Under the condition of torque, the weight of the transmission shaft is lighter, and at the same time, the qualification rate of product welding production is improved.

Description

technical field [0001] The invention belongs to the technical field of automobile drive shafts, and in particular relates to a friction welded aluminum alloy drive shaft. Background technique [0002] At present, there are mainly two welding methods for the welding of the transmission shaft tube body and the shaft yoke or spline sleeve, namely MIG welding and friction welding. During aluminum alloy MIG welding, under the protection of high-purity argon, the arc heat source burned between the continuously fed welding wire and the workpiece is used to melt the welding wire and base metal and continuously fill the molten pool, and form a weld after cooling. The remelting of the material, the weld is a cast structure, and the temperature of the heat-affected zone of the weld during the welding process is much higher than the artificial aging temperature of 180°C, which causes the material to age and reduce the strength. In addition, due to the aluminum alloy MIG welding The wor...

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Problems solved by technology

Due to the complex structure and shape of the shaft fork or spline sleeve, the heat capacity is large, and the temperature rises slowly. The temperature gradient of the weldment on the side of the shaft fork or spline sleeve is large, and its strength loss is relatively small; while the temperature gradient of the shaft tube clamped in the fixed fixture is small, and the strength loss is large. The tube is easy to produce out-of-round deformation, which reduces the effective cross-sectional area of ​​the weld, and the coaxiality of the shaft fork or spline sleeve and the shaft tube decreases after welding, so that high-quality friction welding joints cannot be obtained, and the scrap rate of friction welding production is high. This problem is especially obvious when the transmission shaft with a thinner shaft tube wall thickness is welded

Since the temperature of the friction interface material rises sharply to about 550°C, although under the action of the upsetting force, the friction interface material with the highest temperature is extruded into a flanging, but the temperature of the material that finally forms the weld and its nearby heat-affected zone is much higher than The artificial aging temperature of 180°C, over-aging will cause the strength of the welded joint to decrease, and the strength coefficient of the weld can only reach about 80% in general

[0004] There are two main problems in the current friction welding of aluminum alloy transmission shafts. One is that the strength of the welded joints is significantly lower than that of the base metal. Redundancy of strength leads to material waste and cost increase; secondly, the deformation of the shaft tube during forging is large, which reduces the effective cross-sectional area of ​​the weld seam, and the coaxiality error of the transmission shaft after welding is large, resulting in a high scrap rate

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