活塞组漏气量超标原因分析及优化

Overrun blow-by cause analysis and optimization of piston assembly

为解决某高强化柴油机漏气量超标问题,对活塞组的漏气通道进行分析,并利用有限元及动力学分析软件对配缸间隙进行对比分析并进行优化,结果显示优化配缸间隙后漏气量仅降低0.82%。对活塞环装配前后的尺寸进行检测对比,确认活塞环装配不当使得闭口间隙超差并出现漏光现象,是造成发动机漏气量超标的主要原因。对活塞环的装配设备改进之后进行500 h发动机试验,漏气量降低到规定范围内。结果表明,该发动机活塞与缸套的配缸间隙对漏气量影响较小,活塞环装配不当造成漏气量超标。

In order to solve the leakage of a strengthened diesel piston,blow-by passages are analyzed.FEA and dynamics analysis are used for cylinder clearance improving,and the blow-by is reduced only for 0.82%.Rings′dimensions before and after assembly are inspected and compared,the results show the closed gaps are out of specification and light-tight effect is damaged which indicates that improper assembly process is the main cause of overrun blow-by.After optimized ring assembly equipment,a new engine is operated for 500 hours and its blow-by is reduced to a value within specification.The results indicate that cylinder clearance shows limited impact to blow-by and improper assembly of piston rings will bring high blow-by.