US 12,067,963 B2
Soundproof structure body
Akihiko Ohtsu, Ashigara-kami-gun (JP); Shinya Hakuta, Ashigara-kami-gun (JP); Yoshihiro Sugawara, Ashigara-kami-gun (JP); and Shogo Yamazoe, Ashigara-kami-gun (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Apr. 16, 2021, as Appl. No. 17/232,770.
Application 17/232,770 is a continuation of application No. PCT/JP2019/039356, filed on Oct. 4, 2019.
Claims priority of application No. 2018-197582 (JP), filed on Oct. 19, 2018.
Prior Publication US 2021/0233506 A1, Jul. 29, 2021
Int. Cl. G10K 11/172 (2006.01); F24F 13/24 (2006.01); G10K 11/16 (2006.01); B60R 13/08 (2006.01)
CPC G10K 11/172 (2013.01) [F24F 13/24 (2013.01); G10K 11/161 (2013.01); B60R 13/08 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A soundproof structure body comprising:
a tubular tube body having an opening portion; and
a resonance type soundproof structure formed from an air impermeable material and directly installed on a wall surface of the tube body,
wherein the resonance type soundproof structure has a portion that is in direct contact with an inside of the tube body,
wherein a phase difference θ, at an upstream of the resonance type soundproof structure, between a reflected wave in the resonance type soundproof structure and a reflected wave of a transmitted wave transmitted through the resonance type soundproof structure and reflected by the opening portion satisfies the following Inequation (1) with respect to a resonance frequency of the resonance type soundproof structure.
|θ−π|≤≤π/3  (1)
 
3. The soundproof structure body according to claim 1,
wherein in a case where a waveguide distance from the resonance type soundproof structure to the opening portion of the tube body in a waveguide composed of an opening tube line through which a sound wave travels in the tube body, which includes an opening end correction, is denoted by L, an average cross-sectional area of the waveguide included in the tube body is denoted by S1, and a reflectance obtained by the opening end is denoted by Rx(f), an acoustic impedance Z1 defined by Expression (3) satisfies Expression (2) on a complex plane in a frequency range in which a frequency f satisfies f<c/(4×(√(S1/π))),
|(Z1−Z0)/(Z1+Z0)|<√Rx(f)  (2)
Z1=(A×Z0+B)/(C×Z0+D)  (3),
A, B, C, and D are given by Expression (4) representing a transfer matrix T,

OG Complex Work Unit Math
Z0 is given by Expression (5),
Z0=ρc/S1  (5),
Sx is given by Expression (6),
Sx=(1+Rx(f))/(1−Rx(f))×S1  (6), and
ZR is an impedance of the resonance type soundproof structure, c is a speed of sound, ρ is a density of air, and k is a wave number.