Soundproof structure body

Patent metadata

Field	Value
Publication number	US-11636839-B2
Application number	US-202017039072-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Apr 18, 2018
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

Provided is a soundproof structure body including an opening member that forms an opening tube line having a cross-sectional area S, and at least two resonance structures for sound waves that are installed inside the opening tube line, and in a case where a cross-sectional area of the resonance structure is defined as Si, a width thereof is defined as di, an interval between the two resonance structures is defined as L, an impedance of the two resonance structures is defined as Zi, and a synthetic acoustic impedance is defined as Zc, a condition of Expression (1) is satisfied at a resonance frequency f0 at which a theoretical absorption value At is a maximum value. This soundproof structure body can realize high absorption using a plurality of resonance structures.At(f0, L, S, Si, di, Zi)>0.75  (1),Here, L>0, S>0, Si (i=1, 2)>0, di (i=1, 2)>0

First claim

What is claimed is:

1. A soundproof structure body comprising:
an opening member that forms an opening tube line having a cross-sectional area S; and
at least two resonance structures for sound waves that are installed inside the opening tube line,
wherein a cross-sectional area Si (i=1, 2, . . . , where the resonance structure having a smaller i number is located on an upstream side) in the opening tube line and a width di (i=1, 2, . . . ) of the resonance structure in a waveguide forward direction are more than 0,
at least two resonance structures among the resonance structures are installed to be spaced apart at an interval L (L>0) from each other, and
in a case where an impedance of each of the two resonance structures installed to be spaced apart at the interval L from each other is defined as Zi (i=1, 2), and
a synthetic acoustic impedance, in which the two resonance structures and the interval thereof, a change in the cross-sectional area in the waveguide forward direction, and the two resonance structures are considered, is defined as Zc,
a condition of Expression (1) is satisfied at a resonance frequency f0 at which a theoretical absorption value At given by Expression (2) is a maximum value,
At ( f 0, L, S, Si, di, Zi )>0.75  (1),

where, in a case where L>0, S>0, Si(i=1, 2)>0, di(i=1, 2)>0,
and, f, L, S, Si, di, Zi (i=1, 2) is represented by x,
At ( x )=1−|( Zc ( x )− Z 0)/( Zc ( x )+ Z 0)| 2 −|2/( Ac ( x )+ Bc ( x )/ Z 0+ Z 0 Cc ( x )+ Dc ( x ))| 2   (2),

where, the synthetic acoustic impedance Zc(x) is defined by Expression (3)

Zc
⁡

(
x
)

=

Z
0

⁢

A
C

⁡

(
x
)

+

B
C

⁡

(
x
)

Z
0

⁢

C
C

⁡

(
x
)

+

D
C

⁡

(
x
)

,

(
3
)

in Expression (3), Z0 is an acoustic impedance of an opening tube line represented by Zair/S(=Z0) (S is a tube line cross-sectional area),
Zair denotes an acoustic impedance of air and is given by Zair=ρc, ρ denotes a density of air, and c denotes a speed of sound,
Ac(x), Bc(x), Cc(x), and Dc(x) are elements of a synthetic transfer matrix, and are defined by Expression (4), and
in Expression (4), Tc is a synthetic transfer matrix of the two resonance structures

T
C

=

T

d
⁢

⁢

1
/
2

⁢

T
1

⁢

T

d
⁢

⁢

1
/
2

⁢

T

L
-

d
⁢

⁢

1
/
2

-

d
⁢

⁢

2
/
2

Assignees

• Fujifilm Corp

Inventors

• Ohtsu Akihiko
• Sugawara Yoshihiro
• Hakuta Shinya
• Yamazoe Shogo

Classifications

• G10K11/172 Primary

  using resonance effects · CPC title

• F24F2013/245

  using resonance · CPC title

• F24F13/02

  Ducting arrangements · CPC title

• G10K11/161 Primary

  in systems with fluid flow (G10K11/162 takes precedence; gas flow silencers or exhaust apparatus for machines or engines in general or for internal combustion engine F01N, noise absorbers in pipes or pipe systems F16L55/02; noise absorption in air conditioning and ventilation F24F13/24; silencing exhaust or propulsion jets in aircraft B64D33/06) · CPC title

• F24F13/24

  Means for preventing or suppressing noise · CPC title