发动机漏水故障分析与密封结构优化

Fault analysis of engine water leakage and sealing structure optimization

针对采用过盈配合密封的发动机出水管管接头漏水故障率高的问题,通过对漏水故障件的拆解、分析,确定漏水的主要原因为人工装配过程不规范及管接头粗糙度不达标。采用出水管固定工装、提高管接头头部粗糙度要求、管接头压装工装等改进装配工艺,重新设计2种管接头新螺纹密封结构等优化措施,并进行装配工艺试验验证。验证结果表明:过盈配合密封方式受到装配过程、零部件一致性等因素影响较大,不建议采用;F型螺柱密封结构可靠,漏水故障率仅为0.6%,且无需涂胶,对零部件螺纹配合要求不高,可有效解决管接头漏水问题。

In the view of high water leakage failure rate of the outlet pipe joints of a batch of engines with interference fit seals, the reasons of water leakage are found by disassembling the water leakage fault parts. The results show that the main causes of water leakage are the non-standard manual assembly process and the non-standard roughness of the pipe joints. The assembly process is improved, the outlet pipe fixing tooling and the pipe joint press fitting tooling are designed, the roughness requirements of the pipe joint head is increased. Two new thread sealing structures of pipe joints are also redesigned and tested. The process verification results show that the interference fit sealing method is greatly affected by the assembly process, parts consistency and other factors, so it is not recommended to use this method for sealing. The F-type stud sealing structure shows reliable sealing performance, and the water leakage failure rate is only 0.6%, which can effectively solve the water leakage problem of the pipe joint, and can provide reference for the subsequent pipe joint sealing design.