祝传亮1,2，曹国帅1,2，郑洪国1,2，黄超1,2，赵昌锋1,2,张学禄1,2

1.滨州渤海活塞有限公司，山东滨州256600；2.山东省发动机活塞摩擦副重点实验室，山东滨州256600

摘要：针对某发动机在耐久试验中出现的活塞环岸断裂故障，对故障活塞进行结构强度计算、物理性能和铸造缺陷检测，确定故障原因为发动机形成液压锁；分析造成发动机液压锁液体来源，总结不同液体造成的液压锁判定方法，分析液压锁导致的活塞失效模式。结果表明：冷却液、机油和燃油是形成发动机液压锁液体的主要来源；可以通过活塞表面外观、活塞顶面积碳和发动机性能判定形成液压锁的液体类型；液压锁可以导致活塞环岸断裂和活塞顶面开裂等故障。该研究可以为液压锁形成分析提供参考。

关键词：发动机；液压锁；活塞；有限元分析；失效模式

Abstract：According to the failure of piston ring land breakage in endurance test, the structural strength of the piston is calculated,the physical performance and the casting defect detection of the piston are tested.It is determined that the failure is caused by the formation of a hydraulic lock in the engine,the sources of engine hydraulic lock fluid are analyzed, the determination methods of hydraulic lock caused by different liquids are summarized, and the piston failure modes caused by hydraulic lock failur are analyzed.The results show that the coolant, oil and fuel are the main liquid to form the engine hydraulic lock. The cause of the hydraulic lock can be determined by the appearance of piston surface, the carbon of piston top area and the performance of the engine. Hydraulic lock may cause the piston ring bank fracture and the piston top surface crack and other faults. This study can provide reference for the failure analysis of hydraulic lock.

Keywords:engine;hydraulic lock;piston; finite element analysis;failure mode