中高频振动引起车内噪声分析研究

Study and Analysis of the Automotive Interior Noise Caused by Medium and High Frequency Vibration

为解决某车型车内噪声问题,在发动机振动引起车内噪声问题分析方法的基础上,确定横摆中高频振动是引起车内噪声的主要原因,并提出解决方案。在发动机怠速状态下测量输油管道的振动状态,根据汽车噪声、振动和声振粗糙度基本理论,通过模态分析和频谱分析,得出输油管道横摆中高频振动引起的车身底板振动向车内辐射噪声。采用加装胶垫的方法降噪,改进后的实车试验结果表明,车内声压峰值从32dB下降到24dB,横摆中高频振动得到有效控制。

In order to solve the interior noise prob- lem of a certain vehicle type and based on analytic techniques identifying noise problems caused by engine vibrations, a transverse swing having medium and high frequencies is established to be the primary cause; so- lutions to the problem are proposed. The transverse swing of the pipeline having medium and high frequen- cies causes vibrations of the baseplate, which radiates noise to the interior according to the fundamental theo- ry of the vehicle NVH （noise, vibration and harsh- ness）. This is concluded as a result of modal analysis and frequency spectrum analysis, wherein the vibration state of the pipeline was measured while the engine is idling. Actual vehicle tests were conducted wherein a rubber cushion was attached for noise reduction. The test results using this improvement showed that the peak value of the automotive interior sound pressure declined from 32 dB to 24 dB, and the transverse swing having medium and high frequencies was effec- tively controlled.