Research On The Weld Failure Of The Rear Axle Plate Of The Air Suspension

The rear suspension of medium-and high-grade passenger bus of 12 m and above,often employs four-link non-independent air suspension structure.It's often formed through mounting the C-shaped bracket on the rear axle with U-bolts,and with air springs mounted on both sides of the C-shaped bracket to support the vehicle.In the operation of vehicles,especially for vehicles on various roads in mountainous areas such as the southwestern area,the weld on the rear axle plate cracks frequently(the MMBF is about 300,000 km),while this kind of problems are reported even more frequent in the proving ground.The paper will solve the problem through theoretical analyses on the topic in combination with experiments and verifications with test buses.The technical background of the paper is the four-link non-independent rear air suspension structures of medium-and high-grade passenger bus of 12 m and above from a bus company.The paper firstly completes 3D modeling on the suspension components with CATIA software,and then conducts finite element analysis and optimization analysis on the 3D model with HyperWorks software,to calculated the stress of the weld.Through the simulation comparison of the model,the influences of the suspension structure size,the axle plate structure,the structural process of the plate weld and the suspension assembly process on the weld stress of the axle plate are studied,In order to determine the main influencing factors and optimization methods of the stress of the weld.Finally,through improvements on the suspension structure,the axle plate structure and the assembly welding process,the weld on the rear axle plate of the air suspension of passenger bus of 12 m and above can survive more than 12,000 km on various roads in the proving ground.And the purpose of no faults for the weld in the entire life cycle of the bus is achieved finally.