某款Ⅴ型六缸发动机缸内异响问题诊断与优化

Diagnosis and Optimization of Knock Noise in Cylinder of Ⅴ6 Engine

发动机是汽车重要零部件之一,当发动机的机体内部出现敲击问题的时候,就会听到“哒哒”或“当当”等敲击噪声,这种异响问题势必会引起用户抱怨,影响品牌形象。文章通过对某款Ⅴ型六缸发动机在冷机启动后的敲击异响问题振动噪声测试与分析,诊断出敲击发生的位置,确认了敲击的主要频率范围,通过正时信号角度域分析,推导出敲击发生时刻,各缸气门、活塞等运动副所处的位置,分析出最有可能发生敲击的运动副并进行验证,通过结构优化解决此敲击异响问题。

Engine is one of the important parts in a vehicle,when knock noise inside the cylinder occurs,people will perceive"rattling"or"dangdang"noise,which is often leading to customer complaints and negatively impacts the brand image.In this paper,by investigating the abnormal vibration and noises of a Ⅴ6 engine after cold start via testing and analysis,the location of knock is identified,and the main frequency range of the knock noises is determined.By analyzing the angle domain of timing signal,the positions of each cylinder valve,piston and other moving pairs at the time of knock are deduced.The components and parts which are most likely to generate knocking noises are analyzed and verified.Finally,the issue of the abnormal knocking noises is resolved through structural optimization.