应用隔声罩降低汽车噪声的研究

Study on Application of Acoustical Enclosure for Decreasing Automobile Noise

本文对动态情况下轻型隔声罩的隔声性能做了某些理论探讨,推导了相应的插入损失公式,并在实验室内进行了模拟实验,其结果与理论推导基本吻合。文中应用相干分析技术确定了BJ121A型汽车的主噪声源,设计并加工了局部隔声和隧道式隔声罩,结果使其车外加速噪声有所降低。

Some noise insulation properties of light-duty acoustical enclosure in dynamiccase were studied. The relevant formula for calculating insertion loss was derived.The simulated test in laboratory had been done, and its results basically concurredwith what obtained by theory. Using coherence analysis technique, the main noise source of BJ 121A had beenfound. The partial acoustical enclosure and tunnel-like acoustical enclosure weredesigned and installed, and the out-of-automobile speed-up noise level was reducedfrom 87.5 dB ( A ) to 83dB ( A ) .