轻型客车发动机曲轴断裂原因分析

轻型客车发动机曲轴在实际使用中多次发生断裂的问题,分析其宏观断口形貌,采用金相显微镜、直读光谱仪、万能试验机和显微硬度计对其金相组织、化学成分、力学性能以及结合ANSYS有限元技术对曲轴断裂原因进行分析。结果表明:曲轴连杆颈与扇形板交接处圆弧过渡半径过小,容易产生较大的应力集中,在外加载荷作用下导致曲轴的断裂;同时曲轴润滑条件差,加速了断裂的发生。根据断裂原因提出了曲轴质量控制措施建议。

Failure Analysis of Light Bus Engine Crankshaft

Failure analysis of a light bus engine crankshaft was carried out by macro observation on fracture surface, chemical composition analysis, microstructure examination, property testing and finite-element analysis. The results show that the radius of arc transition between the neck of connecting rod and the sector plate was lower than the design requirement, increasing stress concentration, which is the main cause for the fracture of the crankshaft. In addition, bad lubrication accelerated the fracture of the crankshaft. Suggestions were made based on the study.