1.前言内燃机车的噪声,主要有柴油机噪声、排气噪声、冷却风扇噪声及传动箱噪声等。对于这种种噪声,只有使用不同的方法,才能得到完满的防声效果。日本对内燃机车这些噪声的研究,是从1973年开始的。头两年,主要是研究哪种方法可以提高对各种噪声的防声效果,例如,采用什么样的消声器可以降低排气噪声,采用什么样的隔声材料可以隔除机械噪声 1. Foreword The noise of diesel locomotives includes diesel engine noise, exhaust noise, cooling fan noise and transmission noise. For this kind of noise, only use different methods, in order to get a perfect anti-sound effect. Japan’s study of the noise of diesel locomotives started in 1973. In the first two years, we mainly studied which method can improve the noise prevention effect of various noises. For example, what kind of muffler can be used to reduce the exhaust noise and what kind of sound insulation material can be used to eliminate the mechanical noise