Abstract:

The axle housing of heavy-duty truck has large dimension， and high load-carrying capacity， and the stress on the axle housing cover part is complex. There is cracking phenomenon in the process of development test and engineering application. The design method of heavy-duty truck axle housing by seamless steel pipe bulging forming is proposed in this paper， and the process flow of bulging forming is given. The axle-housing sample of 1：1 axle load with load of 11.5 tons is designed and trial-produced. Through the finite element simulation of the bulging forming process， the changes of the wall thickness of the axle housing， as well as the stress distribution law of the transition arc surface of the rear cover are revealed， which shows that the deformation strengthening coefficient of the bridge package reaches 1.37~1.61. Through the static strength simulation and test under the torsion condition with a 65 kN longitudinal force applied on the upper thrust rod support of the sample， it is revealed that the maximum tangential strain and normal strain of the axle housing are 317με， with the maximum longitudinal deformation per meter of wheelbase less than 0.91mm. Moreover， the design basis for the front plane width of the bridge package higher than both sides and the wall thickness of the seamless steel pipe is given. Based on the load spectrum collected from the real vehicle， the fatigue test under the torsional condition is carried out and the axle housing sample remains intact after five stages of 1.419 million cycles in total. The research results show that the axle housing of heavy-duty truck by seamless steel pipe bulging forming has light weigh， high strength and stiffness， which provides an important reference for solving thoroughly the failure of axle housing.

Key words: heavy-duty truck, bulging forming, design of axle housing, torsion condition, performance analysis