某四缸TGDI发动机怠速正时皮带噪声解决及优化

Solution and Optimization of Idle Timing Belt Noise of a Four Cylinder TGDI Engine

直喷发动机的正时皮带在怠速工况较为容易出现噪声问题,由于曲轴正时链轮的轮齿对正时皮带激励而产生一连串噪声。怠速时正时激励噪声由空气辐射及悬置等结构振动传入驾驶室,引起用户抱怨。问题频率为基础频率两倍左右达到峰值。采用试验方法与仿真手段结合的方法预测正时皮带动态特性、噪声产生机理及解决措施,确定了试验与仿真结果结合的优化方案,达到了可接受的NVH特性。

The timing belt of the direct injection engine is easy to produce noise under idle condition.When the engine is running,there are a series of noise problems caused by the excitation of the teeth of the crankshaft timing sprocket to the timing belt.The idle timing excitation noise is introduced into the cab by the structure vibration such as air radiation and mounting,which causes user complaints.The peak value of the problem frequency was observed at about twice the basic frequency.This paper introduces the method of combining the test method with the simulation method to predict the dynamic characteristics of the timing belt,the mechanism of noise generation and the solution measures,and determines the optimized scheme combining the test and simulation results,so as to achieve the acceptable NVH characteristics.