刘召伟1,2，孙琛媛1,2，郭金朋1,2，董勃1,2

1.滨州渤海活塞有限公司，山东滨州256602；2.山东省发动机活塞摩擦副重点实验室，山东滨州256602

摘要：针对某船用柴油机活塞销孔开裂问题，对活塞进行失效分析，确认开裂的原因为销座结构和销孔设计不合理，通过有限元分析匹配不同销孔形线的销座结构对销孔接触压力和疲劳系数的影响，根据仿真结果确定优化方案，经650 h耐久试验，优化后的活塞销孔未出现开裂。研究表明，活塞销座阶梯形结构配合销孔双侧二次曲线异形结构可以改善销孔接触压力分布，使销孔承载面应力均匀进而降低销孔开裂风险。

关键词：活塞；销孔；开裂；形线；有限元分析

Abstract:Failure analysis of piston pin is conducted in order to improve its performance for a marine diesel. The results indicate that the pin bore cracking is caused by improper design of pin boss and pin bore. FEA is used to study the performance of different pin boss and bore profile, as well as the pin bore contact pressure and fatigue factors. Optimization profile is confirmed by the FEA results and no cracking is found in optimized piston after engine test. It could be confirmed that the stepped pin boss designed with secondary curve of bore profile can improve pressure distribution, even bore stress and reduce the risk of cracking.

Keywords:piston; pin bore; cracking; profile; finite element analysis