DEVICE FOR ATTENUATING NOISE

摘要

PURPOSE:To avoid the increase in the volume of noise only in a particular direction, by making a noise attenuation device of plural horizontal louvers of such cross-sectional shape as to diffuse noise-making air upward and downward through the device and by attaching the device to the engine enclosure of a construction machine or the like. CONSTITUTION:A silencing louver unit 14, which is provided at the open part 9 of the radiator guard 8 of the engine enclosure of an earth-moving vehicle, is made of a plurality of horizontal louvers 36 extending at intervals in parallel with each other. The louvers 36 are mounted on a fixed frame not shown in the drawing. The silencing louver unit 14 is removable installed at the open part 9. Each louver 36 is made of a sound absorber coated with punched metal of enough punched percentage and is positioned at a prescribed angle to the flow of noise-making air discharged by a cooling fan 3. The upper louvers 36a are shaped to conduct the noise-making air upward. The lower louvers 36b are shaped to conduct the air downward. A wedgeshaped louver 36c is provided beteen the upper and the lower louvers 36a, 36b.