柴油机敲缸故障的振动诊断法

柴油机敲缸是一种常见故障，发生故障时，不仅使柴油机振动加剧，而且使其寿命缩短．活塞横向撞击气缸壁是柴油机发生敲缸故障的主要激励，经实测柴油机运行过程中的４ 个特征参数，即振动持续时间、振动峰峰值、第１ 频带功率谱峰值和第２ 频带功率谱峰值，分析得知：若振动持续时间比正常值有较大增加，且振动峰峰值和第１，第２ 频带内功率谱峰值也增加，则可断定发生了敲缸故障．通过对北京型机车柴油机故障的实际诊断，证实了此诊断方法是可行的．

The vibration diagnostic method of rap vat fault of diesel engine

Rap vat fault of diesel engine not only aggravates vibration,but also decreases service life of diesel engine.The main reason is that the piston strikes the wall of cylinder in cross way.By means of measurement and analysis of 4 characteristic parameters in the period of running, this paper reaches a conclusion:if continuous period of vibration is longer than normal,and vibration peak and power peak in first and second frequency band increases too ,then the rap vat fault must take place.The conclusion was verified in Beijing type diesel locomotive