抄録
A road maintenance vehicle has often been used at night in order to avoid traffic confusion in major cities in Japan. The noise reduction of the road maintenance vehicle has been demanded from the environmental point of view. The suction truck used for cleaning a sewer is one of them. Since the weight of a truck increases even if it performs soundproofing measures with covering a suction truck with acoustic insulation etc., the recovered amount of salvaged material will be restricted. For this reason, the working efficiency of a suction truck will fall. On the other hand, a side brunch is lightweight and is simple structure. And there is no example, which loaded the side brunch to the suction machine in the past. In this paper, numerical analyses by BEM and experiments by using a real thing are conducted in order to reduce the noise of the real suction machine. As a result, noise reduction of 6dB overall level and 20dB of 160Hz component could be achieved.
