| 摘要 |
PROBLEM TO BE SOLVED: To provide a noise absorbing structure and a noise absorbing/insulating structure capable of exerting a noise absorption property suitable for noise having a wide frequency range. SOLUTION: First and second noise absorbing portions 26a, 26b whose noise absorbing characteristics are different are provided in a noise absorbing/insulating box 12. Respective noise absorbing portions 26a, 26b are constituted by being equipped with noise absorbing walls 21a, 21b which are arranged toward a noise source and noise insulating walls 22a, 22b which are arranged by being opposed respectively to the noise absorbing walls 21a, 21b. First noise absorbing holes 20a are provided by being penetrated in the first noise absorbing wall 21a as an aggregate of holes 28 whose diameters are equal, second noise absorbing holes 20b are provided by being penetrated in the second noise absorbing wall 21b as an aggregate of holes 28 whose diameters are larger than that of the holes 28. That is, the noise absorbing box 12 is formed so that internal opening areas of noise absorbing holes 20a, 20b are different for every noise absorbing portions 26a, 26b, respectively. COPYRIGHT: (C)2006,JPO&NCIPI
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