分动箱油冷系统输油钢管断裂原因分析及优化措施

Fracture Failure, Optimization Measures For The Oil Steel Pipe Of the Transfer Case Oil Cooling System

某越野车辆分动箱油冷系统输油钢管在整车可靠性路试中出现断裂故障。通过对故障件的断口进行外观检查、微观观察、金相分析、化学成分分析,并分析钢管固定方式和结构特点,得出钢管折点处断裂的原因是:钢管是悬臂梁布置方式,折点处应力集中,受到长时间振动激励,出现疲劳断裂。针对失效原因,对钢管结构和固定方式进行优化。结果表明:优化后钢管结构及其固定方式通过了道路可靠性试验,有效避免了该类故障的再次发生。

For the oil steel pipe of the transfer case oil cooling system of the off-road vehicle was broken on vehicle road reliability test.In order to find the failure cause,macroscopic observation,microscopic observation,metallographic examination and chemical composition analysis were carried out,and combined with the analysis of the fixing mode and structural characteristics of the oil steel pipe.The results show that the oil steel pipe is a cantilever beam arrangement,where the stress is concentrated at the break point,and is stimulated by long-term vibration,resulting in fatigue fracture.For the failure reason,the oil steel pipe structure and fixed mode are optimized.The results show that the optimized oil steel pipe structure and its fixed mode passed the vehicle road reliability test and avoided the recurrence of such faults.