| 摘要 |
PROBLEM TO BE SOLVED: To provide a noise-proof cover which has the very high noise insulating property capable of shutting out transmission sound and solid propagating sound, and whose manufacture is easy and cost is inexpensive. SOLUTION: A plurality of covers 2 are fixed to a main body 1, wherein a machine 1a such as a motor, gear and a fan that generates the noise is included. The cover 2 has the hollow tightly closed structure comprising an outer wall 2a, an inner wall 2b and an elastic member 2c such as rubber and the like for connecting the outer surfaces of these walls, and the inside is made vacuum. An emitted sound from the machine 1a strikes the inner wall 2b and vibrates the inner surface of the wall. Since the inside of the cover 2 is in vacuum, there is no medium for transmitting the vibration. The vibration is not transmitted to the outer wall 2a. At the peripheral part, the elastic member 2c shuts out the solid propagation of the bending vibration. |
