JP7085702B1 - Sound absorption system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound absorbing system which is space-saving and has an improved sound absorbing effect.
A sound absorbing system according to an embodiment includes a first sound absorbing material, a second sound absorbing layer, and a first sound absorbing material including a first division layer sandwiched between the first sound absorbing layer and the second sound absorbing layer. A sound absorbing system including a third sound absorbing layer, a fourth sound absorbing layer, and a second sound absorbing material including a second division layer sandwiched between the third sound absorbing layer and the fourth sound absorbing layer, wherein the first sound absorbing material is used. Placed in contact with the first wall area of the first wall, the first sound absorbing layer is placed between the first wall area and the first section layer, and the second sound absorbing material intersects the first wall at less than 180 °. A third wall region is placed in contact with the second wall region, a third sound absorbing layer is placed between the second wall region and the second partition layer, and a third wall region is located between the first wall region and the second wall region. The wall area is separated from the first sound absorbing material and the second sound absorbing material, and the distance between the first sound absorbing material and the second sound absorbing material is smaller than the thickness of either the first sound absorbing material or the second sound absorbing material.
[Selection diagram] Fig. 1

Description

Embodiments of the present invention relate to a sound absorbing system.

There is a sound absorbing material in which foam layers having different densities are laminated on a porous sound absorbing structure that absorbs sound by converting the energy of sound waves into heat energy by utilizing the viscous resistance of air.

Patent Document 1 discloses a foam layer and a sound absorbing material in which porous body layers are laminated on both sides of the foam layer. Here, the foam layer is a foam containing each component of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate as raw material components. The porous body layer is formed of general-purpose glass wool or rock wool.

In the sound absorbing material having such a structure, the foam layer having a high density plays the role of an additional mass, and the porous body layer having a low density on the wall side plays a role of a spring, thereby forming a dynamic vibration absorber, in particular. The sound absorption coefficient in the low frequency band can be improved. Further, by providing the porous body layer on the sound source side as well, the sound absorbing characteristics in the high frequency region of 150 Hz or higher are improved, and it is possible to provide a sound absorbing material that can be used even in the wide frequency region.

Japanese Patent No. 4148318

The embodiment according to the present disclosure provides a sound absorbing system that saves space and has an improved sound absorbing effect.

The sound absorbing system according to one embodiment includes a first sound absorbing material including a first sound absorbing layer, a second sound absorbing layer, and a first division layer sandwiched between the first sound absorbing layer and the second sound absorbing layer, and a third sound absorbing layer. A sound absorbing system including a fourth sound absorbing layer and a second sound absorbing material including a second partition layer sandwiched between the third sound absorbing layer and the fourth sound absorbing layer, wherein the first sound absorbing material is a first wall. A second wall that is placed in contact with the first wall area, the first sound absorbing layer is placed between the first wall area and the first partition layer, and the second sound absorbing material intersects the first wall at less than 180 °. The third wall region is arranged in contact with the second wall region, the third sound absorbing layer is arranged between the second wall region and the second partition layer, and the third wall region between the first wall region and the second wall region is. It is separated from the first sound absorbing material and the second sound absorbing material, and the distance between the first sound absorbing material and the second sound absorbing material is smaller than the thickness of either the first sound absorbing material or the second sound absorbing material.

The embodiment according to the present disclosure can provide a sound absorption system that saves space and has improved sound absorption efficiency.

It is a perspective view schematically showing the sound absorption system which concerns on one Embodiment. It is a top view which shows schematically the sound absorption system which concerns on one Embodiment. It is a perspective view schematically showing the sound absorption system which concerns on one Embodiment. It is a top view which shows schematically the sound absorption system which concerns on one Embodiment. It is a perspective view schematically showing the sound absorption system which concerns on one Embodiment. It is a top view which shows schematically the sound absorption system which concerns on one Embodiment. It is a perspective view schematically showing the sound absorption system which concerns on one Embodiment. It is a top view which shows schematically the sound absorption system which concerns on one Embodiment. It is a perspective view schematically showing the sound absorption system which concerns on one Embodiment. It is sectional drawing which shows schematically the sound absorption system which concerns on one Embodiment. It is a perspective view which shows typically the sound absorption system which concerns on one modification. It is a top view which shows schematically the sound absorption system which concerns on one modification. It is a perspective view which shows typically the sound absorption system which concerns on one modification. It is a graph which shows an example of the ratio of sound absorption at the 1/3 octave band center frequency of Example 1 with respect to Comparative Example 1. FIG.

Hereinafter, the sound absorbing system according to the present embodiment will be specifically described with reference to the drawings. In the following description, elements having substantially the same function and configuration are described with the same code or a code with an alphabet added after the same code, and will be described in duplicate only when necessary. Each embodiment shown below exemplifies a system or method for embodying the technical idea of this embodiment. The technical idea of the embodiment does not specify the material, shape, structure, arrangement, etc. of the component parts to the following. Various modifications can be made to the embodiments without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof.

The drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment in order to clarify the explanation, but the drawings are merely examples and limit the interpretation of the present invention. It's not something to do. In the present specification and each drawing, elements having the same functions as those described with respect to the existing drawings may be designated by the same reference numerals and duplicate description may be omitted.

In the present specification, "α is A, B or C", "α is any of A, B and C", and "α is one selected from the group consisting of A, B and C". Unless otherwise specified, the expression "include" does not exclude the case where α includes a plurality of combinations of A to C. Furthermore, these expressions do not exclude cases where α contains other elements.

The following embodiments and modifications can be combined with each other as long as there is no technical conflict.

[First Embodiment]
<Sound absorption system>
FIG. 1 is a perspective view schematically showing an overall configuration of a sound absorbing system according to an embodiment. FIG. 2 is a top view schematically showing a sound absorbing system according to an embodiment. In FIG. 1, the vertical direction is referred to as the Z direction, and the two directions intersecting the Z direction are referred to as the X direction and the Y direction. The XZ surface is referred to as the first wall 100, the YZ surface is referred to as the second wall 200, and the XY surface (floor surface) is referred to as the third wall 300.

As shown in FIGS. 1 and 2, the sound absorbing system 1 according to the present embodiment will be described by showing an example of being applied to an end portion where the first wall 100 and the second wall 200 are connected. However, the sound absorbing system 1 is not limited to this, and can be applied to an end portion where two surfaces such as a wall, a floor, and a ceiling surrounding a space requiring sound absorption are connected. The sound absorbing system 1 includes a first sound absorbing material 10 arranged on the first wall 100 and a second sound absorbing material 20 arranged on the second wall 200.

The first sound absorbing material 10 includes a first sound absorbing layer 11, a second sound absorbing layer 12, and a first division layer 13. The first sound absorbing layer 11, the first division layer 13, and the second sound absorbing layer 12 are laminated in this order in a plane. The first division layer 13 is sandwiched between the first sound absorbing layer 11 and the second sound absorbing layer 12. The first sound absorbing material 10 is arranged in contact with the first region 101 of the first wall 100. The first sound absorbing material 10 is arranged so that the second sound absorbing layer 12 faces the space side where sound absorption is required. That is, the first sound absorbing layer 11 is arranged between the first region 101 and the first division layer 13. The first division layer 13 is arranged substantially parallel to the first wall 100. The first sound absorbing material 10 is separated from the second wall 200.

The second sound absorbing material 20 includes a third sound absorbing layer 21, a fourth sound absorbing layer 22, and a second division layer 23. The third sound absorbing layer 21, the second division layer 23, and the fourth sound absorbing layer 22 are laminated in this order in a plane. The second division layer 23 is sandwiched between the third sound absorbing layer 21 and the fourth sound absorbing layer 22 in contact with each other. The second sound absorbing material 20 is arranged in contact with the second region 201 of the second wall 200. The second sound absorbing material 20 is arranged so that the fourth sound absorbing layer 22 faces the space side where sound absorption is required. That is, the third sound absorbing layer 21 is arranged between the second region 201 and the second division layer 23. The second division layer 23 is arranged substantially parallel to the second wall 200. The second sound absorbing material 20 is separated from the first wall 100.

As the first section layer 13 and the second section layer 23, for example, a film of a polymer organic substance such as a resin is used. The first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, and the fourth sound absorbing layer 22 are an aggregate of fibers, for example, either glass wool or rock wool, or a combination thereof. Is used.

The density of the first division layer 13 of the first sound absorbing material 10 is higher than the density of the first sound absorbing layer 11 and the second sound absorbing layer 12. The density of the second division layer 23 of the second sound absorbing material 20 is higher than the density of the third sound absorbing layer 21 and the fourth sound absorbing layer 22. Here, the densities of the first division layer 13, the first sound absorption layer 11, the second sound absorption layer 12, the second division layer 23, the third sound absorption layer 21, and the fourth sound absorption layer 22 are the densities of the materials constituting each layer. It shows the density of the entire layer, not the density.

The Young's modulus of the first sound absorbing layer 11 and the second sound absorbing layer 12 of the first sound absorbing material 10 is smaller than the Young's modulus of the first division layer 13. The Young's modulus of the third sound absorbing layer 21 and the fourth sound absorbing layer 22 of the second sound absorbing material 20 is smaller than the Young's modulus of the second division layer 23.

When a sound wave is incident on the second sound absorbing layer 12 or the fourth sound absorbing layer 22, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave is converted into heat energy by the viscous resistance of this air, and the sound absorption in the high frequency band is performed. Will be done.

When the sound wave is incident on the first division layer 13, the first division layer 13 is arranged between the first division layer 13 and the first wall 100, so that the first division layer 13 has an additional mass (weight) and a first. 1 The sound absorbing layer 11 acts as a spring (air spring), and can absorb sound in a low frequency band by membrane vibration. Similarly, when a sound wave is incident on the second division layer 23, the third division layer 23 is arranged between the second division layer 23 and the second wall 200, so that the second division layer 23 has an additional mass (weight). ), The third sound absorbing layer 21 acts as a spring (air spring), and can absorb sound in a low frequency band by membrane vibration.

Here, the region in contact with the first sound absorbing material 10 of the first wall 100 is the first region 101, the region in contact with the second sound absorbing material 20 of the second wall 200 is the second region 201, the first region 101 and the second region 201. The area between them is referred to as a third area 301. The first region 101 and the second region 201 are not in contact with each other, and at least a part thereof face each other. The third region 301 is a region separated from the first sound absorbing material 10 and the second sound absorbing material 20.

In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are separated from each other. The distance D1 between the first sound absorbing material 10 and the second sound absorbing material 20 is smaller than either the thickness d10 of the first sound absorbing material 10 or the thickness d20 of the second sound absorbing material 20. The distance D1 between the first sound absorbing material 10 and the second sound absorbing material 20 is either the distance d11 from the first wall 100 to the first division layer 13 or the distance d21 from the second wall 200 to the second division layer 23. It is preferably smaller than the distance of. In other words, the distance D1 between the first sound absorbing material 10 and the second sound absorbing material 20 is smaller than either the thickness d11 of the first sound absorbing layer 11 or the thickness d21 of the third sound absorbing layer 21. Is preferable. The distance D1 between the first sound absorbing material 10 and the second sound absorbing material 20 may be zero as described later, and in that case, it indicates that they are in contact with each other somewhere. Since the distance D1 between the first sound absorbing material 10 and the second sound absorbing material 20 is smaller, the sound waves diffusely reflected at the end where the first wall 100 and the second wall 200 are connected are generated by the first sound absorbing material 10 and the first. 2 The sound absorbing material 20 can absorb sound without missing it, and the sound absorbing efficiency can be improved. The surface of the first sound absorbing material 10 and the second sound absorbing material 20 (the surface on the side of the second sound absorbing layer 12 and the fourth sound absorbing layer 22) is exposed to the space side where sound absorption is required, so that the sound absorbing region can be fully utilized. Can be done. Further, by arranging the first sound absorbing material 10 and the second sound absorbing material 20 at the end where the first wall 100 and the second wall 200 are connected, space saving becomes possible. Here, the distance D1 indicates the minimum distance between the first sound absorbing material 10 and the second sound absorbing material 20, and the thickness d10 of the first sound absorbing material 10 is the thickness of the first sound absorbing material 10 in the stacking direction (Y direction). The thickness d20 of the second sound absorbing material 20 indicates the thickness of the second sound absorbing material 20 in the stacking direction (X direction). The thickness d11 of the first sound absorbing layer 11 indicates the thickness of the first sound absorbing layer 11 in the stacking direction (Y direction), and the thickness d21 of the third sound absorbing layer 21 indicates the thickness of the third sound absorbing layer 21 in the stacking direction (X direction). Indicates the thickness of.

In the present embodiment, the distance between the second sound absorbing layer 12 and the fourth sound absorbing layer 22 is preferably smaller than the distance between the first sound absorbing layer 11 and the third sound absorbing layer 21. The distance between the second sound absorbing layer 12 and the fourth sound absorbing layer 22 may be zero as described later, and in that case, it indicates that they are in contact with each other somewhere. Since the distance between the second sound absorbing layer 12 and the fourth sound absorbing layer 22 is smaller, the sound waves diffusely reflected at the end where the first wall 100 and the second wall 200 are connected are generated by the first sound absorbing material 10 and the second. Sound can be absorbed without being missed by the sound absorbing material 20, and the sound absorbing efficiency can be improved. By exposing the surfaces of the second sound absorbing layer 12 and the fourth sound absorbing layer 22 to the space side where sound absorption is required, the sound absorbing region can be fully utilized. Further, by arranging the first sound absorbing material 10 and the second sound absorbing material 20 at the end where the first wall 100 and the second wall 200 are connected, space saving becomes possible. Here, the distance between the second sound absorbing layer 12 and the fourth sound absorbing layer 22 indicates the minimum distance between the second sound absorbing layer 12 and the fourth sound absorbing layer 22, and the first sound absorbing layer 11 and the third sound absorbing layer 22. The distance between 21 indicates the minimum distance between the first sound absorbing layer 11 and the third sound absorbing layer 21.

In the present embodiment, the distance d12 between the first sound absorbing material 10 and the second wall 200 is larger than the thickness d20 of the second sound absorbing material 20. The distance d22 between the second sound absorbing material 20 and the first wall 100 is larger than the thickness d10 of the first sound absorbing material 10. The frequency of the sound wave that can be absorbed changes depending on the distance d12 between the first sound absorbing material 10 and the second wall 200 and the distance d22 between the second sound absorbing material 20 and the first wall 100, and the sound absorbing efficiency is improved depending on the frequency. ..

The distance d13 between the first sound absorbing material 10 and the third wall 300 connected to the first wall 100 and the second wall 200 is the thickness d10 of the first sound absorbing material 10 and the thickness d20 of the second sound absorbing material 20. It is preferably smaller than any of the thicknesses. The distance d23 between the second sound absorbing material 20 and the third wall 300 is preferably smaller than either the thickness d10 of the first sound absorbing material 10 or the thickness d20 of the second sound absorbing material 20. The distance d13 between the first sound absorbing material 10 and the third wall 300 and the distance d23 between the second sound absorbing material 20 and the third wall 300 may be the same or different. The distance d13 between the first sound absorbing material 10 and the third wall 300 and the distance d23 between the second sound absorbing material 20 and the third wall 300 may be zero, in which case the third wall. Indicates that it is in contact with 300. The distance d13 between the first sound absorbing material 10 and the third wall 300 and the distance d23 between the second sound absorbing material 20 and the third wall 300 are smaller, so that the first wall 100, the second wall 200, and the first wall 300 are smaller. Sound waves diffusely reflected at the end of the three walls 300 can be absorbed by the first sound absorbing material 10 and the second sound absorbing material 20 without being missed, and the sound absorbing efficiency can be improved.

In the present embodiment, the first wall 100 and the second wall 200 intersect each other in a plane shape to form a corner portion. The third region 301 includes a part of the first wall 100 and a part of the second wall 200 at this corner. That is, the third region 301 includes a plane extending from the first region 101 of the first wall 100 to the corner portion and a plane extending from the second region 201 of the second wall 200 to the corner portion. However, the shape of the third region 301 is not limited to this, and the shape of the third region 301 may be smoothly connected by a curved surface from the first region 101 of the first wall 100 to the second region 201 of the second wall 200, or two or more. It may be connected by a plane of, or it may be a combination of a plane and a curved surface. The third region 301 may include a concave portion or a convex portion. The third region 301 may be separated from the first sound absorbing material 10 and the second sound absorbing material 20.

In the present embodiment, the angle formed by the first wall 100 and the second wall 200 is about 90 °. However, the present invention is not limited to this, and the angle formed by the first wall 100 and the second wall 200 may be less than 180 °. This angle is preferably 150 ° or less, and generally preferably 90 ° or more and 135 ° or less. Here, the angle formed by the first wall 100 and the second wall 200 indicates the angle on the space side formed by the first wall 100 and the second wall 200. As the angle formed by the first wall 100 and the second wall 200 becomes smaller, the space sandwiched between the first wall 100 and the second wall 200 becomes narrower, and diffused reflection of sound waves becomes more likely to occur. The larger the angle formed by the first wall 100 and the second wall 200, the closer the arrangement of the first sound absorbing material 10 and the second sound absorbing material 20 is from the corners, so that the first wall 100, the second wall 200, and the first wall 1 The space surrounded by the sound absorbing material 10 and the second sound absorbing material 20 becomes smaller, and diffused reflection of sound waves is likely to occur.

As the angle formed by the first wall 100 and the second wall 200 becomes smaller, the first sound absorbing material 10 and the second sound absorbing material 20 become farther from the corners, while the first sound absorbing material 10 and the second sound absorbing material 20 become thinner. By doing so, each can be brought closer to the corner, and space can be saved. The larger the angle formed by the first wall 100 and the second wall 200, the closer the first sound absorbing material 10 and the second sound absorbing material 20 are from the corners, while moving each of them away from the corners, so that the first sound absorbing material 10 And the second sound absorbing material 20 can be made thicker, and the sound absorbing efficiency can be improved. In either case, it can be appropriately set in relation to the sound absorption efficiency and the utilization part of the room.

In the present embodiment, the shapes of the first sound absorbing material 10 and the second sound absorbing material 20 are substantially rectangular, and the corners connecting the first wall 100 and the second wall 200 extend along the extending direction (Z direction). The long side is extended. The region where the first sound absorbing material 10 and the second sound absorbing material 20 face each other is preferably long along the direction in which the corners extend (Z direction). That is, it is preferable that the long sides of the first sound absorbing material 10 and the second sound absorbing material 20 are as large as possible. The third region 301 between the first region 101 and the second region 201 extends along the long sides of the first sound absorbing material 10 and the second sound absorbing material 20. As long as the above conditions are satisfied, the third region 301 preferably has a length along the direction in which the corners extend (Z direction). By having such a configuration, the sound absorption efficiency of the first sound absorbing material 10 and the second sound absorbing material 20 can be improved. The width w10 of the first sound absorbing material 10 is preferably larger than the thickness d10 of the first sound absorbing material 10. The width w20 of the second sound absorbing material 20 is preferably larger than the thickness d20 of the second sound absorbing material 20. Having such a configuration makes it possible to save space. However, the shapes of the first sound absorbing material 10 and the second sound absorbing material 20 are not particularly limited, and may satisfy the above conditions.

In the sound absorbing system 1 according to the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are arranged along the first wall 100 or the second wall 200, so that the sound is most echoed at the end portion. The sound wave transmitted along the wall is incident on the first sound absorbing layer 11 or the third sound absorbing layer 21. Further, the first sound absorbing material 10 and the second sound absorbing material 20 are arranged at the end where the first wall 100 and the second wall 200 are connected, so that the sound cannot be completely absorbed and the first sound absorbing layer 11 or the third sound absorbing layer 11 or the third. The sound wave that has passed through the sound absorbing layer 21 bounces off the first wall 100 or the second wall 200, and is again incident on the first sound absorbing layer 11 or the third sound absorbing layer 21. When a sound wave is incident on the first sound absorbing layer 11 or the third sound absorbing layer 21, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave is converted into heat energy by the viscous resistance of this air, and the sound absorption in the high frequency band is performed. Will be done. By having the above-mentioned configuration, the sound absorbing system 1 according to the present embodiment can improve the sound absorbing efficiency and save space.

<Composition of sound absorbing material>
In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 have the same configuration. However, the present invention is not limited to this, and the first sound absorbing material 10 and the second sound absorbing material 20 may have different configurations. As the first sound absorbing material 10 and the second sound absorbing material 20, for example, the sound absorbing material described in Japanese Patent No. 4148318 may be used.

The surface densities of the first section layer 13 and the second section layer 23 in the present embodiment are preferably in the range of 100 kg / m ² or more and 1000 kg / m ² or less. If the surface density of the first section layer 13 and the ^second section layer 23 is less than 100 kg / m ² , the air permeability becomes too good, and the sound absorption efficiency in the low frequency region deteriorates. Becomes too bad and the sound is reflected and it becomes difficult to absorb the sound.

As the first section layer 13 and the second section layer 23 in the present embodiment, a polymer organic substance and a film such as a resin can be used.

In the present embodiment, the first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, and the fourth sound absorbing layer 22 may have the same configuration or may have different configurations.

The first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, and the fourth sound absorbing layer 22 are specifically formed by laminating glass wool or rock wool of the same type or different types. May be good.

[Second Embodiment]
<Sound absorption system>
The configuration of the sound absorbing system according to the present embodiment is the same as the configuration of the sound absorbing system according to the first embodiment, except that the first sound absorbing material 10 and the second sound absorbing material 20 come into contact with each other. The same description as in the first embodiment will be omitted, and here, a part different from the configuration of the sound absorbing system according to the first embodiment will be described. FIG. 3 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the embodiment. FIG. 4 is a top view schematically showing a sound absorbing system according to an embodiment.

As shown in FIGS. 3 and 4, the sound absorbing system 2 according to the present embodiment includes a first sound absorbing material 10 arranged on the first wall 100, a second sound absorbing material 20 arranged on the second wall 200, and the second sound absorbing material 20. To prepare for. What is the relationship between the first region 101 where the first sound absorbing material 10 is arranged, the second region 201 where the second sound absorbing material 20 is arranged, and the third region 301 between the first region 101 and the second region 201? Since it is the same as the first embodiment, it is omitted here.

In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other. The first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other at the end of the second sound absorbing layer 12 and the end of the fourth sound absorbing layer 22. However, the present invention is not limited to this, and as will be described later, it indicates that the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other somewhere.

In the present embodiment, the distance d12 between the first sound absorbing material 10 and the second wall 200 is substantially the same as the thickness d20 of the second sound absorbing material 20. The distance d22 between the second sound absorbing material 20 and the first wall 100 is substantially the same as the thickness d10 of the first sound absorbing material 10.

In the sound absorbing system 2 according to the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other at the end of the second sound absorbing layer 12 and the end of the fourth sound absorbing layer 22. The space surrounded by the wall 100, the second wall 200, the first sound absorbing material 10, and the second sound absorbing material 20 is closed. Even if diffused reflection of sound waves occurs in this space, it is again incident on the first sound absorbing material 10 and the second sound absorbing material 20. When a sound wave enters the first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, or the fourth sound absorbing layer 22, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave due to the viscous resistance of the air. Is converted into heat energy, and sound absorption in a higher frequency band is performed. By having the above-mentioned configuration, the sound absorbing system 2 according to the present embodiment can further improve the sound absorbing efficiency and save space.

[Third Embodiment]
<Sound absorption system>
The configuration of the sound absorbing system according to the present embodiment is the same as the configuration of the sound absorbing system according to the first embodiment, except that the first sound absorbing material 10 and the second sound absorbing material 20 overlap each other. The same description as in the first embodiment will be omitted, and here, a part different from the configuration of the sound absorbing system according to the first embodiment will be described. FIG. 5 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the embodiment. FIG. 6 is a top view schematically showing a sound absorbing system according to an embodiment.

As shown in FIGS. 5 and 6, the sound absorbing system 3 according to the present embodiment includes a first sound absorbing material 10 arranged on the first wall 100, a second sound absorbing material 20 arranged on the second wall 200, and the second sound absorbing material 20. To prepare for. What is the relationship between the first region 101 where the first sound absorbing material 10 is arranged, the second region 201 where the second sound absorbing material 20 is arranged, and the third region 301 between the first region 101 and the second region 201? Since it is the same as the first embodiment, it is omitted here.

In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other. However, the present invention is not limited to this, and the first sound absorbing material 10 and the second sound absorbing material 20 may be separated from each other as described later.

In the present embodiment, the distance d12 between the first sound absorbing material 10 and the second wall 200 is substantially the same as the thickness d20 of the second sound absorbing material 20. The distance d22 between the second sound absorbing material 20 and the first wall 100 is smaller than the thickness d10 of the first sound absorbing material 10.

At least a part of the end surface of the second sound absorbing layer 12 faces the surface of the second sound absorbing material 20 on the side of the fourth sound absorbing layer 22. In the present embodiment, at least a part of the end surface of the second sound absorbing layer 12 and a part of the fourth sound absorbing layer 22 are in contact with each other. However, the present invention is not limited to this, and the second sound absorbing layer 12 and the fourth sound absorbing layer 22 may be separated from each other as described later.

In the sound absorbing system 3 according to the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with at least a part of the end surface of the second sound absorbing layer 12 and a part of the fourth sound absorbing layer 22. By doing so, the space surrounded by the first wall 100, the second wall 200, the first sound absorbing material 10, and the second sound absorbing material 20 is closed. Even if diffused reflection of sound waves occurs here, it is incident on the first sound absorbing material 10 and the second sound absorbing material 20 again. When a sound wave enters the first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, or the fourth sound absorbing layer 22, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave due to the viscous resistance of the air. Is converted into heat energy, and sound absorption in a higher frequency band is performed. Further, the frequency of the sound wave that can be absorbed changes depending on the distance d22 between the second sound absorbing material 20 and the first wall 100, and the sound absorbing efficiency is improved depending on the frequency. By having the above-mentioned configuration, the sound absorbing system 3 according to the present embodiment can further improve the sound absorbing efficiency and save space.

[Fourth Embodiment]
<Sound absorption system>
The configuration of the sound absorbing system according to the present embodiment is the same as the configuration of the sound absorbing system according to the first embodiment, except that the first sound absorbing material 10 and the second sound absorbing material 20 overlap each other. The same description as in the first embodiment will be omitted, and here, a part different from the configuration of the sound absorbing system according to the first embodiment will be described. FIG. 7 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the embodiment. FIG. 8 is a top view schematically showing a sound absorbing system according to an embodiment.

As shown in FIGS. 7 and 8, the sound absorbing system 4 according to the present embodiment includes a first sound absorbing material 10 arranged on the first wall 100, a second sound absorbing material 20 arranged on the second wall 200, and the second sound absorbing material 20. To prepare for. What is the relationship between the first region 101 where the first sound absorbing material 10 is arranged, the second region 201 where the second sound absorbing material 20 is arranged, and the third region 301 between the first region 101 and the second region 201? Since it is the same as the first embodiment, it is omitted here.

In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with each other. However, the present invention is not limited to this, and the first sound absorbing material 10 and the second sound absorbing material 20 may be separated from each other as described later.

In the present embodiment, the distance d12 between the first sound absorbing material 10 and the second wall 200 is substantially the same as the thickness d20 of the second sound absorbing material 20. The distance d22 between the second sound absorbing material 20 and the first wall 100 is smaller than the distance between the first division layer 13 and the first wall 100.

The end surface of the second sound absorbing layer 12 faces the surface of the second sound absorbing material 20 on the side of the fourth sound absorbing layer 22. In the present embodiment, the end surface of the second sound absorbing layer 12 and a part of the fourth sound absorbing layer 22 are in contact with each other. However, the present invention is not limited to this, and the second sound absorbing layer 12 and the fourth sound absorbing layer 22 may be separated from each other as described later.

The end surface of the first division layer 13 faces the surface of the second sound absorbing material 20 on the side of the fourth sound absorbing layer 22. In the present embodiment, the end surface of the first division layer 13 and a part of the fourth sound absorbing layer 22 are in contact with each other. However, the present invention is not limited to this, and the first division layer 13 and the fourth sound absorbing layer 22 may be separated from each other as described later.

A part of the end surface of the first sound absorbing layer 11 faces the surface of the second sound absorbing material 20 on the side of the fourth sound absorbing layer 22. In the present embodiment, a part of the end surface of the first sound absorbing layer 11 and a part of the fourth sound absorbing layer 22 are in contact with each other. However, the present invention is not limited to this, and the first sound absorbing layer 11 and the fourth sound absorbing layer 22 may be separated from each other as described later.

In the sound absorbing system 4 according to the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are in contact with a part of the end surface of the first sound absorbing layer 11 and a part of the fourth sound absorbing layer 22. As a result, the space surrounded by the first wall 100, the second wall 200, the first sound absorbing material 10, and the second sound absorbing material 20 is closed. Even if diffused reflection of sound waves occurs here, it is incident on the first sound absorbing material 10 and the second sound absorbing material 20 again. The sound waves incident on the second sound absorbing layer 12 and the fourth sound absorbing layer 22 can further increase the distance in the sound absorbing layer. When a sound wave enters the first sound absorbing layer 11, the second sound absorbing layer 12, the third sound absorbing layer 21, or the fourth sound absorbing layer 22, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave due to the viscous resistance of the air. Is converted into heat energy, and sound absorption in a higher frequency band is performed. Further, the frequency of the sound wave that can be absorbed changes depending on the distance d22 between the second sound absorbing material 20 and the first wall 100, and the sound absorbing efficiency is improved depending on the frequency. By having the above-mentioned configuration, the sound absorbing system 4 according to the present embodiment can further improve the sound absorbing efficiency and save space.

[Fifth Embodiment]
<Sound absorption system>
The configuration of the sound absorbing system according to the first embodiment includes the third sound absorbing material 30, the fourth sound absorbing material 40, the fifth sound absorbing material 50, and the sixth sound absorbing material 60. Is the same as. The same description as in the first embodiment will be omitted, and here, a part different from the configuration of the sound absorbing system according to the first embodiment will be described. FIG. 9 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the embodiment. FIG. 10 is a cross-sectional view schematically showing a sound absorbing system according to an embodiment. FIG. 10 is a cross-sectional view taken along the line AA'of FIG.

As shown in FIGS. 9 and 10, the sound absorbing system 5 according to the present embodiment will be described by showing an example of being applied to an end portion where the first wall 100, the second wall 200, and the third wall 300 are connected. do. However, the sound absorbing system 5 is not limited to this, and can be applied to an end portion to which three surfaces such as a wall, a floor, and a ceiling surrounding a space requiring sound absorption are connected. The sound absorbing system 5 is provided on the first sound absorbing material 10 and the sixth sound absorbing material 60 arranged on the first wall 100, the second sound absorbing material 20 and the third sound absorbing material 30 arranged on the second wall 200, and the third wall 300. The fourth sound absorbing material 40 and the fifth sound absorbing material 50 to be arranged are provided. Since the relationship between the configuration of each sound absorbing material and the wall in contact with the sound absorbing material is the same as that of the first embodiment, it is omitted here. The relationship between the first sound absorbing material 10 and the second sound absorbing material 20, the third sound absorbing material 30 and the fourth sound absorbing material 40, and the fifth sound absorbing material 50 and the sixth sound absorbing material 60 is the same as in the first embodiment. Let's omit it. Since the relationships between the first sound absorbing material 10 and the sixth sound absorbing material 60, the second sound absorbing material 20 and the third sound absorbing material 30, and the fourth sound absorbing material 40 and the fifth sound absorbing material 50 are the same, here, the first sound absorbing material is used. The material 10, the second sound absorbing material 20, and the third sound absorbing material 30 will be described.

The third sound absorbing material 30 includes a fifth sound absorbing layer 31, a sixth sound absorbing layer 32, and a third division layer 33. The fifth sound absorbing layer 31, the third division layer 33, and the sixth sound absorbing layer 32 are laminated in this order in a plane. The third sound absorbing material 30 is arranged in contact with the fourth region 401 of the second wall 200. The third sound absorbing material 30 is arranged so that the sixth sound absorbing layer 32 faces the space side where sound absorption is required. That is, the fifth sound absorbing layer 31 is arranged between the fourth region 401 and the third division layer 33. The third division layer 33 is arranged substantially parallel to the second wall 200. The third sound absorbing material 30 is separated from the first wall 100 and the third wall 300.

Here, the region where the first sound absorbing material 10 of the first wall 100 is in contact is the first region 101, the region where the second sound absorbing material 20 of the second wall 200 is in contact is the second region 201, and the region where the second sound absorbing material 20 is in contact is the second region 201 and the third sound absorbing material of the second wall 200. The region in contact with 30 is referred to as a fourth region 401, and the region between the first region 101 and the fourth region 401 is referred to as a fifth region 501. The first region 101 and the fourth region 401 are not adjacent to each other. The fifth region 501 is separated from the first sound absorbing material 10 and the third sound absorbing material 30. The second region 201 and the fourth region 401 are separated from each other. That is, the second sound absorbing material 20 and the third sound absorbing material 30 are separated from each other. However, the present invention is not limited to this, and the second sound absorbing material 20 and the third sound absorbing material 30 may be arranged in contact with each other. The second sound absorbing material 20 and the third sound absorbing material 30 may be integrally formed.

In the present embodiment, the first sound absorbing material 10 and the third sound absorbing material 30 are separated from each other. The distance D2 between the first sound absorbing material 10 and the third sound absorbing material 30 is smaller than either the thickness d10 of the first sound absorbing material 10 or the thickness d30 of the third sound absorbing material 30. The distance D2 between the first sound absorbing material 10 and the third sound absorbing material 30 is either the distance d11 from the first wall 100 to the first division layer 13 or the distance d31 from the second wall 200 to the third division layer 33. It is preferably smaller than the distance of. In other words, the distance D2 between the first sound absorbing material 10 and the third sound absorbing material 30 is smaller than either the thickness d11 of the first sound absorbing layer 11 or the thickness d31 of the fifth sound absorbing layer 31. Is preferable. The distance D2 between the first sound absorbing material 10 and the third sound absorbing material 30 may be zero as described above, and in that case, it indicates that they are in contact with each other somewhere. Here, the distance D2 indicates the minimum distance between the first sound absorbing material 10 and the third sound absorbing material 30, and the thickness d30 of the third sound absorbing material 30 is the thickness of the third sound absorbing material 30 in the stacking direction (X direction). show. The thickness d31 of the fifth sound absorbing layer 31 indicates the thickness of the fifth sound absorbing layer 31 in the stacking direction (X direction).

In FIG. 10, the distance d32 between the third sound absorbing material 30 and the first wall 100 is larger than the thickness d10 of the first sound absorbing material 10. However, the distance d32 between the third sound absorbing material 30 and the first wall 100 is not limited to this, and the distance d32 is larger than either the thickness d10 of the first sound absorbing material 10 or the thickness d30 of the third sound absorbing material 30. Small is preferable. The distance d32 between the third sound absorbing material 30 and the first wall 100 is either the distance d11 from the first wall 100 to the first division layer 13 or the distance d31 from the second wall 200 to the third division layer 33. It is preferably smaller than the distance. The distance d32 between the third sound absorbing material 30 and the first wall 100 may be zero, in which case it indicates that it is in contact with the first wall 100. Since the distance d32 between the third sound absorbing material 30 and the first wall 100 is small, sound waves diffusely reflected at the end where the first wall 100 and the second wall 200 are connected are generated by the first sound absorbing material 10 and the third sound absorbing material 10. Sound can be absorbed without missing with the material 30, and the sound absorption efficiency can be improved. Further, by arranging the first sound absorbing material 10 and the third sound absorbing material 30 at the end where the first wall 100 and the second wall 200 are connected, space saving becomes possible. Since the distance d32 between the third sound absorbing material 30 and the first wall 100 is large, the surfaces of the first sound absorbing material 10 and the third sound absorbing material 30 (the surfaces on the second sound absorbing layer 12 and the sixth sound absorbing layer 32 side). Is exposed to the space side where sound absorption is required, so that the sound absorption area can be fully utilized.

The distance d13 between the first sound absorbing material 10 and the third wall 300 is preferably smaller than either the thickness d10 of the first sound absorbing material 10 or the thickness d30 of the third sound absorbing material 30. The distance d13 between the first sound absorbing material 10 and the third wall 300 may be zero, in which case it indicates that it is in contact with the third wall 300. The distance d23 between the second sound absorbing material 20 and the third wall 300 is larger than the width w30 of the third sound absorbing material 30. The distance d33 between the third sound absorbing material 30 and the third wall 300 is preferably smaller than either the thickness d10 of the first sound absorbing material 10 or the thickness d30 of the third sound absorbing material 30. The distance d33 between the third sound absorbing material 30 and the third wall 300 is either the distance d11 from the first wall 100 to the first division layer 13 or the distance d31 from the second wall 200 to the third division layer 33. It is preferably smaller than the distance. The distance d13 between the first sound absorbing material 10 and the third wall 300 and the distance d33 between the third sound absorbing material 30 and the third wall 300 may be the same or different. The distance d13 between the first sound absorbing material 10 and the third wall 300 and the distance d33 between the third sound absorbing material 30 and the third wall 300 are smaller, so that the first wall 100, the second wall 200, and the first wall 300 are smaller. Sound waves diffusely reflected at the end of the three walls 300 can be absorbed by the first sound absorbing material 10 and the third sound absorbing material 30 without being missed, and the sound absorbing efficiency can be improved.

The fifth region 501 includes a part of the first wall 100 and a part of the second wall 200 at the corner. That is, the fifth region 501 includes a plane extending from the first region 101 of the first wall 100 to the corner portion and a plane extending from the fourth region 401 of the second wall 200 to the corner portion. However, the shape of the fifth region 501 is not particularly limited, and the shape of the fifth region 501 is not particularly limited. The fifth region 501 may be separated from the first sound absorbing material 10 and the third sound absorbing material 30.

In the present embodiment, the shapes of the first sound absorbing material 10, the second sound absorbing material 20, and the third sound absorbing material 30 are substantially rectangular. The long side of the first sound absorbing material 10 and the second sound absorbing material 20 extends in the direction (Z direction) in which the corner portion connecting the first wall 100 and the second wall 200 extends. The third sound absorbing material 30 has a long side extending in the direction (Y direction) in which the corner portion connecting the second wall 200 and the third wall 300 extends. The width w30 of the third sound absorbing material 30 is preferably larger than the thickness d30 of the third sound absorbing material 30. However, the shape of the third sound absorbing material 30 is not particularly limited, and it is sufficient that the above conditions are satisfied.

In the sound absorbing system 5 according to the present embodiment, the sound is produced by arranging the first sound absorbing material 10, the second sound absorbing material 20, and the third sound absorbing material 30 along the first wall 100 or the second wall 200. The sound wave transmitted along the wall toward the most reverberant end is incident on the first sound absorbing layer 11, the third sound absorbing layer 21, or the fifth sound absorbing layer 31. Further, the first sound absorbing material 10, the second sound absorbing material 20, and the third sound absorbing material 30 are arranged at the end where the first wall 100 and the second wall 200 are connected, so that the first sound absorbing material cannot be completely absorbed. The sound sound that has passed through the sound absorbing layer 11, the third sound absorbing layer 21, or the fifth sound absorbing layer 31 bounces off the first wall 100 or the second wall 200, and again, the first sound absorbing layer 11, the third sound absorbing layer 21, or the third sound absorbing layer 21. 5 It is incident on the sound absorbing layer 31. When a sound wave is incident on the first sound absorbing layer 11, the third sound absorbing layer 21, or the fifth sound absorbing layer 31, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave is converted into heat energy by the viscous resistance of the air. Sound absorption in the high frequency band is performed. By having the above-mentioned configuration, the sound absorbing system 5 according to the present embodiment can further improve the sound absorbing efficiency and save space.

In the sound absorbing system 5 according to the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20, the third sound absorbing material 30 and the fourth sound absorbing material 40, the fifth sound absorbing material 50 and the sixth sound absorbing material 60 are formed on the first wall. By arranging at each end where 100, the second wall 200, and the third wall 300 are connected, the first wall 100, the second wall 200, the third wall 300, the first sound absorbing material 10, and the second sound absorbing material are arranged. 20, the space surrounded by the third sound absorbing material 30, the fourth sound absorbing material 40, the fifth sound absorbing material 50, and the sixth sound absorbing material 60 is closed. Even if diffused reflection of sound waves occurs here, it is again incident on the first sound absorbing material 10, the second sound absorbing material 20, the third sound absorbing material 30, the fourth sound absorbing material 40, the fifth sound absorbing material 50, and the sixth sound absorbing material 60. do. When the sound wave is incident on each sound absorbing layer, the air in the void portion of the sound absorbing layer vibrates, and the energy of the sound wave is converted into thermal energy by the viscous resistance of the air, and sound absorption in a higher frequency band is performed. By having the above-mentioned configuration, the sound absorbing system 5 according to the present embodiment can further improve the sound absorbing efficiency and save space.

[Modification 1]
<Sound absorption system>
The configuration of the sound absorbing system according to the present modification is the same as the configuration of the sound absorbing system according to the third embodiment, except that the first sound absorbing material 10 and the second sound absorbing material 20 are separated from each other. The same description as in the third embodiment will be omitted, and here, a part different from the configuration of the sound absorbing system according to the third embodiment will be described. FIG. 11 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the modified example. FIG. 12 is a top view schematically showing a sound absorbing system according to a modified example.

In the present embodiment, the first sound absorbing material 10 and the second sound absorbing material 20 are separated from each other. Since the distance D3 between the first sound absorbing material 10 and the second sound absorbing material 20 is the same as the distance D1 of the first embodiment, it is omitted here. Here, the distance D3 indicates the minimum distance between the first sound absorbing material 10 and the second sound absorbing material 20.

[Modification 2]
<Sound absorption system>
The configuration of the sound absorbing system according to this modification is other than arranging the first sound absorbing material 10 and the second sound absorbing material 20 at the respective ends where the first wall 100, the second wall 200, and the third wall 300 are connected. , Since the configuration is the same as that of the sound absorbing system according to the first embodiment, the description thereof is omitted here. FIG. 13 is a perspective view schematically showing the overall configuration of the sound absorbing system according to the modified example.

[Example 1]
Using the sound absorption system 5 according to the fifth embodiment, a reverberation room method sound absorption coefficient measurement test conforming to JIS-A-1409 (1998) was performed. The total area of the sound absorbing material used in Example 1 was 0.444 m ² . The remaining time of the sound at the center frequency of the 1/3 octave band under the condition according to Example 1 was measured, and the sound absorption volume per unit area as compared with the case without the sound absorption system was calculated.

[Comparative Example 1]
One plate-shaped sound absorbing material was placed on the floor surface, and a reverberation room method sound absorption coefficient measurement test conforming to JIS-A-1409 (1998) was conducted in the same manner as in Example 1. The total area of the sound absorbing material used in Comparative Example 1 was 0.888 m ² . The remaining time of the sound at the center frequency of the 1/3 octave band under the condition according to Comparative Example 1 was measured, and the sound absorption volume per unit area as compared with the case without the sound absorption system was calculated.

FIG. 14 is a graph showing the ratio of the absorption volume of Example 1 when the absorption volume of Comparative Example 1 is 1. As shown in FIG. 14, even if the same sound absorbing material is used, by using the sound absorbing system 5 according to the fifth embodiment in the first embodiment, the sound absorbing coefficient on the high frequency band side (generally 400 Hz or more) is significantly increased. You can see that it has improved.

1, 2, 3, 4, 5 Sound absorption system, 10 1st sound absorption material, 11 1st sound absorption layer, 12 2nd sound absorption layer, 13 1st division layer, 20 2nd sound absorption material, 21 3rd sound absorption layer, 22nd 4 sound absorbing layer, 23 second division layer, 30 third sound absorbing material, 31 fifth sound absorbing layer, 32 sixth sound absorbing layer, 33 third division layer, 40 fourth sound absorbing material, 50 fifth sound absorbing material, 60 sixth sound absorbing material Material, 100 1st wall, 101 1st area, 200 2nd wall, 201 2nd area, 300 3rd wall, 301 3rd area, 401 4th area

Claims (14)

A first sound absorbing material including a first sound absorbing layer, a second sound absorbing layer, and a first division layer sandwiched between the first sound absorbing layer and the second sound absorbing layer.
A second sound absorbing material including a third sound absorbing layer, a fourth sound absorbing layer, and a second division layer sandwiched between the third sound absorbing layer and the fourth sound absorbing layer.
Is a sound absorption system that includes
The first sound absorbing material is arranged in contact with the first wall region of the first wall.
The first sound absorbing layer is arranged between the first wall region and the first dividing layer.
The second sound absorbing material is placed in contact with the second wall region of the second wall that intersects the first wall at less than 180 °.
The third sound absorbing layer is arranged between the second wall region and the second dividing layer.
The third wall region between the first wall region and the second wall region is separated from the first sound absorbing material and the second sound absorbing material.
The distance between the first sound absorbing material and the second sound absorbing material is smaller than the thickness of either the first sound absorbing material or the second sound absorbing material.
Sound absorption system. The sound absorbing system according to claim 1, wherein the distance between the first sound absorbing material and the second sound absorbing material is smaller than the thickness of either the first sound absorbing layer or the third sound absorbing layer. The sound absorbing system according to claim 1 or 2, wherein the first sound absorbing material and the second sound absorbing material come into contact with each other. The distance between the first wall and the third wall intersecting the second wall at less than 180 ° with the first sound absorbing material and the second sound absorbing material is the distance between the first sound absorbing material and the second sound absorbing material. The sound absorbing system according to any one of claims 1 to 3, which is smaller than any thickness. The sound absorbing system according to any one of claims 1 to 4, wherein at least a part of the end surface of the second sound absorbing layer faces the surface of the fourth sound absorbing layer. The sound absorbing system according to claim 5, wherein a part of the end surface of the first sound absorbing layer faces the surface of the fourth sound absorbing layer. The sound absorbing system according to any one of claims 1 to 6, wherein the first sound absorbing material extends in the first direction, and the second sound absorbing material extends in the first direction. A third sound absorbing material including a fifth sound absorbing layer, a sixth sound absorbing layer, and a third division layer sandwiched between the fifth sound absorbing layer and the sixth sound absorbing layer is further included.
The third sound absorbing material is placed in contact with the fourth wall region of the third wall that intersects the first wall and the second wall at less than 180 °.
The fifth sound absorbing layer is arranged between the fourth wall region and the third division layer.
The fifth wall region between the first wall region and the fourth wall region is separated from the first sound absorbing material and the third sound absorbing material.
The distance between the first sound absorbing material and the third sound absorbing material is smaller than the thickness of either the first sound absorbing material or the third sound absorbing material.
The sound absorbing system according to any one of claims 1 to 7. The sound absorbing system according to claim 8, wherein the distance between the first sound absorbing material and the third sound absorbing material is smaller than the thickness of either the first sound absorbing layer or the fifth sound absorbing layer. The sound absorbing system according to claim 8 or 9, wherein at least a part of the end surface of the second sound absorbing layer faces the surface of the sixth sound absorbing layer. The sound absorbing system according to claim 10, wherein a part of the end surface of the first sound absorbing layer faces the surface of the sixth sound absorbing layer. The first sound absorbing material extends in the first direction, the second sound absorbing material extends in the first direction, and the third sound absorbing material extends in the second direction intersecting with the first direction. Item 2. The sound absorbing system according to any one of Items 8 to 11. A sound absorbing system including a seventh sound absorbing layer, an eighth sound absorbing layer, and a fourth sound absorbing material including a fourth division layer sandwiched between the seventh sound absorbing layer and the eighth sound absorbing layer.
The fourth sound absorbing material is arranged in contact with the sixth wall region of the second wall.
The seventh sound absorbing layer is arranged between the sixth wall region and the fourth division layer.
The seventh wall region between the first wall region and the sixth wall region is separated from the first sound absorbing material and the fourth sound absorbing material.
The distance between the first sound absorbing material and the fourth sound absorbing material is smaller than the thickness of either the first sound absorbing material or the fourth sound absorbing material.
The sound absorbing system according to any one of claims 8 to 12. The first sound absorbing material extends in the first direction, the second sound absorbing material extends in the first direction, and the third sound absorbing material extends in the second direction intersecting the first direction. 13. The sound absorbing system according to claim 13, wherein the fourth sound absorbing material extends in the first direction and the third direction intersecting the second direction.

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