| 摘要 |
PROBLEM TO BE SOLVED: To largely reduce sound of a specific frequency band by using a resonance effect of a main body part of a sound absorption structure ad a resonance effect of a cavity layer. SOLUTION: The sound absorption structure 1 is furnished with the cavity layer 11 having a large umber of cavities, a surface layer to cover the cavity layer 11, the main body part 10 having a back surface layer 13 and a peripheral surface layer 14 and a mounting part 20 to mount the main body part 10. A hole part 15 to communicate with the cavities of the cavity layer 11 is formed on the surface layer 12, and a rigidity improving part 16 to improve rigidity of the cavity layer 11 is provided on the surface layer 12. Resonance frequency of the cavity layer 11 is changed by an opening area of the hole part 15. Resonance frequency of the main body part 10 is changed by changing rigidity of the main body part 10 by the rigidity improving part 16. The resonance frequency of the cavity layer 11 and the resonance frequency of the main body part 10 are overlapped in a specific frequency region. COPYRIGHT: (C)2009,JPO&INPIT
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