| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine cover capable of effectively preventing a noise generated from an engine. SOLUTION: A plurality of recessed and protruding parts 30 are formed on a foamed member 20 provided on an inner surface 12 of a rigid cover 11, and thereby a sound absorbing area is enlarged. Therefore, the noise from the engine 90 can be effectively prevented. Further, a space 80 is provided between the recessed and protruding part 30 and the engine 90, and the recessed and protruding part 30 is arranged in an expanded part 14, and thereby the space 80 is enlarged. Therefore, the effect of attenuating the noise by air in the space 80 is increased, and the noise can effectively be prevented. Furthermore, a height difference H of the recessed and protruding part 30 is made to be 1/4 of a wavelength of the noise to be prevented. The noise to be prevented and the reflected noise at the recessed and protruding part 30 offset each other, and thereby the noise can be prevented effectively. COPYRIGHT: (C)2004,JPO
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