| 摘要 |
PROBLEM TO BE SOLVED: To provide a car roof structure capable of suitably reducing harsh road noise felt by an occupant while the car runs by reflecting the sound pressure in air based on the road noise by a reflecting part, and preventing the attenuation. SOLUTION: The car roof structure comprises a roof panel 13, a sound absorbing material 12 to absorb road noise to be transmitted in a cabin of a car in a vicinity of the roof panel 13, and a reflecting plate 11 to reflect the sound pressure in air based on the frequency of road noise to a roof panel surface. The sound absorbing material 12 is air-permeable, and installed on a part at which the particle speed of air based on road noise is high, and the reflecting plate 11 is installed on a part at which the sound pressure in air to the roof panel surface is high. COPYRIGHT: (C)2005,JPO&NCIPI
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