| 摘要 |
PURPOSE:To attenuate a sound energy and reduce a noise by a method wherein an air communication passage communicating an air passage with an external space of a case of a main body of a unit is provided in an air guiding plate constituting a rear wall part of the air passage. CONSTITUTION:During operation of a device, a noise is generated from an axial flow fan 6 and the like. Almost of the noise generated and discharged toward an air guiding plate 9 enters from each of slits 11A, 11B and 11C to each of air communication passages 10A, 10B and 10C. The noise entered the air passages 10A, 10B and 10C is reflected in a zig-zag form by hindering plates 13A and 13B and is discharged to a rear surface side of a main body case 1 of the unit while being attenuated. The attenuated noise is discharged out of the openings 14A and 14B into the interior of the room, reflected by wall surfaces of the room and then transmitted to the interior space as indirected sound. In this way, noise discharged toward the air guide plate 9 is substantially attenuated, so that a noise in the interior of the room is substantially decreased. |
