一种发动机噪声源识别与控制方法的应用

Identification of an Engine's Root of Noise and Optimization on the Engine

基于气流的再生噪声理论,结合运用专业声学测量系统Head noisebook与近声场扫描方法分别对国内一汽车公司某轿车及匹配的动力总成进行噪声测量与噪声源识别,分析出其动力总成产生一种高频啸叫声的频率与发动机转速有关,属于气流再生噪声范畴.通过优化发动机飞轮和离合器罩壳的结构设计,实现了降低这种高频噪声的目的.在大多数转速上,装配更改后飞轮的发动机,60阶噪声声压级比原状态发动机有很大的降低,平均幅度达到5dB(A)左右.

Based on the theory of airflow regeneration noise, the professional acoustical equipment-Head noisebook and the method of close sound field scan are used to measure the noise and search the root of this noise in the car which assembles 475 engine in one automobile Co. , Ltd.. It is found that the powertrain brings high frequency noise, and the high frequency noise which belongs to airflow regeneration noise is related to the rotate speed of the engine. The structure of the flywheel and the clutch cover are optimized in order to reduce this high frequency noise. In many case, the sound pressure level of this noise can debase about 5dB（ A）when assemble new flywheel and the clutch cover.