SOUND ABSORBING PLATE

摘要

PROBLEM TO BE SOLVED: To provide a sound absorbing plate lightweight with high sound absorbing performance. SOLUTION: The sound absorbing plate 1 is formed with a large number of holes 3 in a plate body 2 of a polymeric foam resin material from one face side to the other face side to constitute a large number of closed tube air column parts. The holes constituting the large number of closed tube air column parts are made different in length. The large number of holes are formed obliquely to the extending direction of the plate body. The bulk specific gravity of the sound absorbing plate is 0.4 or less. At least a front face part and a side face part of the plate body are covered with a protective plate. The protective plate comprises a vibration control sheet formed of an organic polymeric material with a peak value of a loss sine (tanδ) of 1.5 or more, and a restraining member with a Young's modulus of 1 GPa or more provided on the outside of the vibration control sheet. Communicating parts corresponding to the large number of holes of the plate body are formed in a front face part of the protective plate. COPYRIGHT: (C)2010,JPO&INPIT