| 摘要:针对某柴油机推杆焊缝开裂故障,采用材料分析、断口电镜扫描分析及金相分析相结合的方法对故障原因进行分析。分析结果表明:推杆头部和杆身焊接内侧焊缝处存在焊接缺陷，在工作应力、组织应力、淬火残余应力和应力集中等因素共同作用下，推杆从疲劳裂纹处发生开裂。据此提出了过盈压装式推杆的改进方案。过盈压装式推杆样件，经有限元分析校核、平台试验机试验以及装机验证，满足设计要求。 |
| 关键词: 柴油机 推杆 焊缝 开裂 |
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| Failure Analysis and Improvement Design ofWeld Cracking in the Push Rod of a Diesel Engine |
| Han Le,Dai Le,Ji Yonghui,Dong Feiying |
| Henan Diesel Engine Industry Co., Ltd.,Henan Luoyang 471039;Military Representative Office of Naval Equipment Department in Luoyang Area，Henan Luoyang 471039 |
| Abstract:To deal with the weld cracking in push rod of a diesel engine, the method combining material analysis, scanning electron microscope (SEM) and metallographic analysis was used to study the causes of the failure. The analysis results show that there was weld flaws on the top of the push rod and at the weld inside of the rod. Under the combined force of working stress, structural stress, quenching residual stress and stress concentration, the push rod cracked at the fatigue cracks.The interference press fitting push rod was thus suggested as an improvement design, and the sample was verified through FEM analysis, platform test and engine test,which verified that the new design could meet with the requirements. |
| Key words: diesel engine push rod weld crack |
