| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress low frequency noise due to a vibration of 10 to 20 Hz of a bridge. <P>SOLUTION: A low frequency noise reduction device 100 is fixed to a bridge 110 and reduces low frequency noise generated from the bridge. The low frequency noise reduction device 100 comprises: a spring part 120 constituted of a plurality of disc springs 122 provided in conjunction, directly receiving the vibration of the bridge, and vibrating in association with the vibration of the bridge; and a weight 130 connected to the spring part in a vibration direction thereof. The resonance frequency of a vibration system constituted of the spring part and the weight is adjusted to a frequency included in a range between 10 Hz and 20 Hz. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
