JP2009169299A - Sound absorbing body, sound absorbing body group, and sound room - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorbing body capable of efficiently absorbing sound. <P>SOLUTION: A vibration part 20 is adhered on an opening part of a chassis 10 with tension applied thereto. A base material layer 21 of the vibration part 20 is a rectangular member in which a high polymer compound is formed like a film. A front surface layer 22 at the front surface of the base material layer 21 and a rear surface layer 23 at the rear surface are adhered layers where finely cut chemical fibers are dispersed at a prescribed density. When a sound wave is incident from the side of the vibration part 20, the vibration part 20 is vibrated by the sound pressure difference between the front side and the rear side of the base material layer 21. Because the sound absorbing body 1 includes the front surface layer 22 and the rear surface layer 23, the front surface layer 22 and the rear surface layer 23 operate as the resistance to the movement of air near the vibration part 20. Thus, the energy of the sound wave is further consumed than the case without the front surface layer 22 or the rear surface layer 23, and a sound absorption rate is further improved than the case without the front surface layer 22 or the rear surface layer 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for absorbing sound.

  As a sound absorber that absorbs sound, there is a sound absorber using a membrane material and an air layer (see, for example, Patent Documents 1 and 2). The sound absorber described in Patent Document 1 has a mesh-like structure that transmits sound waves fixed at a plurality of locations on the front side and the back side of the membrane material, and has an air layer on the back side of the membrane material. Yes. The sound absorber described in Patent Document 2 has an air layer sealed with a thin film, and a plurality of spherical damper members are enclosed in the sealed air layer.

JP 2005-227333 A JP 2006-195006 A

In the sound absorber disclosed in Patent Document 1, when a sound wave is incident on the sound absorber, friction is generated between the film material and the network structure due to vibration caused by the sound wave, and the energy of the sound wave is converted into heat energy. The sound absorbing function is exhibited. However, in the sound absorber disclosed in Patent Document 1, since friction is generated between the film material and the mesh structure, the film material may be deteriorated.
Further, in the sound absorber disclosed in Patent Document 2, when the sound absorber is vibrated by sound waves, the vibration is transmitted to the damper member and the damper member moves, and the vibration is absorbed by this movement and the sound is absorbed. However, since the spherical damper member freely moves in the space inside the sound absorber and collides with the housing or thin film of the sound absorber, there is a problem that sound is generated by this collision.

  The present invention has been made under the above-described background, and an object thereof is to provide a sound absorber that can efficiently absorb sound.

  In order to solve the above-described problem, the present invention includes a housing having an opening and an internal space connected to the opening, and a base material layer formed in a film shape or a plate shape, and at least the base material. And a vibration part having a plurality of fiber pieces bonded to the front surface or the back surface of the layer, and a sound absorber (first sound absorber) in which the opening is closed by the vibration part.

  In addition, the present invention includes a housing having an opening and an internal space connected to the opening, and a base material layer formed in a film shape or a plate shape, and at least on the front surface or the back surface of the base material layer. A sound absorber (second sound absorber) having a vibrating portion in which a plurality of fiber pieces are implanted and having the opening portion closed by the vibrating portion is provided.

  The present invention also includes a housing having an opening and an internal space connected to the opening, a base material layer formed in a film shape or a plate shape, a sealing layer formed in a film shape, a powder And the opening is closed by the base material layer, and the sealing layer has a sealed space formed by the sealing layer, the base material layer, and an inner wall forming the internal space of the housing. Provided is a sound absorber (third sound absorber) which is disposed at a predetermined distance from the base material layer to the inner space side so as to be formed and in which the powder is enclosed in the sealed space.

  The present invention also includes a housing having an opening and an internal space connected to the opening, a base material layer formed in a film shape or a plate shape, a first fiber layer having air permeability, and air permeability. And the opening is closed by the second fiber layer, and the base material layer is formed with a space between the base material layer and the second fiber layer. As described above, the first fiber layer is disposed at a predetermined distance away from the second fiber layer in the direction opposite to the internal space direction, and a space is formed between the first fiber layer and the base material layer. Thus, the sound absorbing body (fourth sound absorbing body) disposed at a predetermined distance from the base material layer to the side opposite to the internal space direction is provided.

Furthermore, the present invention provides a sound absorber group in which any one of the sound absorbers is combined.
In addition, the present invention includes the first sound absorber, and further includes at least one of the second sound absorber, the third sound absorber, and the fourth sound absorber. Provide body groups.
The present invention also provides a sound absorber group that includes the second sound absorber and further includes at least one of the third sound absorber and the fourth sound absorber.
The present invention also provides a sound absorber group having the third sound absorber and further including at least one fourth sound absorber.
Moreover, this invention provides the acoustic chamber which has either of the said sound-absorbing bodies.
Moreover, this invention provides the acoustic chamber which has either of the said sound-absorbing body group.

  According to the present invention, sound absorption can be performed efficiently.

[First Embodiment]
FIG. 1 is a schematic diagram of the appearance of a sound absorber 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. In the sound absorber 1 shown in FIGS. 1 and 2, the dimensions of the sound absorber 1 are different from those of the actual sound absorber 1 for easy understanding of the configuration of the present embodiment.

  As shown in the figure, the sound absorber 1 is formed by a housing 10 and a vibrating portion 20 when roughly classified. The housing 10 is formed of a metal-made rectangular bottom member 11 that serves as a bottom surface of the housing 10 and a metal side wall member 12 that serves as a sidewall of the housing 10. The side wall member 12 has a shape of a square tube, and an end surface on one opening side is fixed to the bottom surface member 11. In addition, the material of the member which forms the housing | casing 10 is not limited to a metal, Other materials, such as a synthetic resin and wood, may be used.

The vibration unit 20 includes a base material layer 21, a front surface layer 22, and a back surface layer 23. The base material layer 21 is a rectangular member in which a polymer compound is formed in a film shape. Moreover, the surface layer 22 on the surface of the base material layer 21 and the back surface layer 23 on the back surface are layers that are bonded so that the short cut or molded chemical fibers have a predetermined density. The fibers forming the front surface layer 22 and the back surface layer 23 may be natural fibers (plant fibers, animal fibers, mineral fibers), not chemical fibers, as long as the fibers have a flow resistance that makes it difficult for air to flow. May be. Moreover, the base material layer 21 may be formed by forming a metal material, a woody material, or the like into a film shape.
The vibration unit 20 is bonded in a state where tension is applied to an end surface opposite to the end surface of the side wall member 12 fixed to the bottom surface member 11 side, whereby the housing 10 and the vibration unit 20 absorb sound. An air layer 30 is formed inside the body 1.

The sound absorber 1 formed as shown in the figure is arranged in a sound field so that the surface layer 22 side of the vibration part 20 is directed to the sound source side, and the sound wave emitted from the sound field is a vibration part of the sound absorber 1. Incident on the 20 side. When sound waves are incident on the film-like member, the film vibrates due to the sound pressure difference between the front side and the back side of the film. At this time, air in the vicinity of the front side and the back side of the membrane moves (vibrates), and this moving (vibrating) speed coincides with the vibrating speed of the membrane.
Further, the surface layer 22 and the back surface layer 23 are not in contact with the base material layer 21 and provide resistance to the air flow excluded by the vibrating film (base material layer 21). Since the surface layer 22 and the back surface layer 23 are not in contact with the base material layer 21, the natural vibration of the base material layer 21 is not affected.
Also in the sound absorber 1 according to the present embodiment, when sound waves are incident from the vibrating unit 20 side, due to the sound pressure difference between the front side (acoustic wave incident side) and the back side (air layer side of the sound absorber 1) of the base material layer 21, The vibration unit 20 vibrates.
Here, in this embodiment, since it has the surface layer 22 and the back surface layer 23 which were formed with the fiber, the surface layer 22 and the back surface layer 23 are used for the movement (vibration) of the air near the vibration part 20. It becomes mechanical resistance.
This configuration is intended to obtain a sound absorbing force by placing a resistance material (fiber) in a place where the particle velocity of sound waves is high, that is, in the vicinity of the vibrating portion 20 that vibrates. Compared to the case without the back layer 23, the energy of the incident sound wave is consumed more, and the sound absorption rate is improved than when the front layer 22 and the back layer 23 are not provided.
In the present embodiment, the front surface layer 22 and the back surface layer 23 are not in contact with the base material layer 21, but do not affect the natural vibration of the base material layer 21, and The surface layer 22 and the back surface layer 23 may be disposed in the immediate vicinity of the base material layer 21 and slightly contact the base material layer 21 as long as resistance is given to the air flow excluded by the layer 21.

[Second Embodiment]
Next, the sound absorber 1A according to the second embodiment of the present invention will be described. FIG. 3 is a schematic diagram of the appearance of the sound absorber 1A, and FIG. 4 is a cross-sectional view taken along the line BB of FIG. As shown in the drawing, the sound absorber 1A is roughly formed by a housing 10 and a vibrating portion 20A. In addition, the housing | casing 10 is formed with the bottom member 11 and the side wall member 12 with the same structure as the housing | casing 10 of 1st Embodiment.

Next, the vibration unit 20 </ b> A according to the present embodiment includes a base material layer 21, a powder 24, and a sealing layer 25.
The base material layer 21 is a rectangular member in which a polymer compound is formed in a film shape. The base material layer 21 is bonded in a state where tension is applied to an end surface opposite to the end surface of the side wall member 12 fixed to the bottom surface member 11 side.
The sealing layer 25 is formed by forming a polymer compound into a film, and the film thickness is thinner than that of the base material layer 21. The sealing layer 25 is fixed inside the housing 10 at a position away from the base material layer 21 toward the bottom surface of the housing 10 by a predetermined distance, and the air layer inside the sound absorber 1 is replaced with the sealing layer 25. And a first air layer surrounded by the casing 10 and a second air layer surrounded by the base material layer 21, the casing 10 and the sealing layer 25. As a result, the powder 24 can be retained (encapsulated) inside the second air layer, and the diffusion of the powder 24 is prevented.
The material of the powder 24 is, for example, zinc white starch, and is enclosed in a space between the base material layer 21 and the sealing layer 25. The powder 24 is made to be a layer having a predetermined thickness on the surface of the base material layer 21.

The sound absorber 1A formed as shown in the figure is arranged in the sound field so that the vibration part 20A side is directed to the sound source side, and the sound wave emitted from the sound field is incident on the vibration part 20A side of the sound absorber 1A. To do. When sound waves are incident from the vibrating portion 20A side, the base material layer 21 vibrates due to the sound pressure difference between the front side (sound wave incident side) and the back side (second air layer side) of the base material layer 21. Here, since the powder 24 is sealed in the second air layer on the back side of the base material layer 21, the powder 24 acts in the same manner as the surface layer 22 and the back surface layer 23 of the first embodiment. It becomes mechanical resistance against the movement (vibration) of the air in the vicinity of the base material layer 21. At the same time, when the powder 24 contacted by the vibration of the base material layer 21 is removed, the kinetic energy of the base material layer 21 is converted into the kinetic energy of the powder 24. Loss occurs.
For this reason, compared with the case where there is no powder 24, the energy of the incident sound wave is consumed, and the sound absorption rate is improved as compared with the case where there is no powder 24. In the present embodiment, since the sealing layer 25 is provided, even if vibration is transmitted to the powder 24, the powder 24 does not diffuse into the first air layer, and the energy of the sound wave is efficiently obtained. Is consumed.
Further, since the individual particles of the powder 24 are very small and light with respect to the base material layer 21, even if the particles of the powder 24 collide with the base material layer 21, the base material layer 21 is separated from the particles of the powder 24. The force received is very small, and there is no problem that a collision sound is generated.
In addition, since the powder 24 is enclosed between the base material layer 21 and the sealing layer 25, the same sound absorbing effect can be obtained regardless of the direction of the vibration part 20A, even if the vibration part 20A is directed upward or downward. Obtainable.

[Third Embodiment]
Next, a sound absorber 1B according to a third embodiment of the present invention will be described. FIG. 5 is a schematic diagram of the appearance of the sound absorber 1B, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. As shown in the figure, the sound absorber 1B is roughly composed of a housing 10A and a vibrating portion 20B.

  The housing 10 </ b> A has the same configuration as the housing 10 of the first embodiment, and is formed by a bottom surface member 11 and a side wall member 12. The casings 10 </ b> B and 10 </ b> C are square tubes having the same shape as the side wall member 12, and the inner peripheral length and outer peripheral length thereof are the same as the inner peripheral length and outer peripheral length of the side wall member 12. The base material layer 21 is a rectangular member in which a polymer compound is formed in a film shape. The surface layer 27 and the back surface layer 28 are breathable nonwoven fabrics, and the area and shape thereof are the same as the area and shape of the bottom surface member 11, respectively. Note that the heights of the housing 10 </ b> B and the housing 10 </ b> C are such that the front surface layer 27 and the back surface layer 28 do not contact each other with the base material layer 21.

In the sound absorber 1B, the four sides of the rectangular back surface layer 28 are bonded to the end surface opposite to the end surface of the side wall member 12 fixed to the bottom surface member 11 side. The housing 10 </ b> B is fixed to the back surface layer 28 such that each side of the opening is abutted with each side of the opening of the side wall member 12 on the back surface layer 28. Further, the four sides of the rectangular base material layer 21 are bonded in a state where tension is applied to the end surface opposite to the end surface fixed to the back surface layer 28 of the housing 10B. The housing 10C is fixed to the base material layer 21 on the base material layer 21 such that each side of the opening is abutted with each side of the opening of the housing 10B. The four sides of the rectangular surface layer 27 are bonded to the end surface opposite to the end surface of the housing 10C that is fixed to the base material layer 21.
With this configuration, in the sound absorber 1B, an air layer is formed between the surface layer 27 and the base material layer 21, between the base material layer 21 and the back surface layer 28, and between the back surface layer 28 and the housing 10A. Has been.

  The sound absorber 1B formed as shown in the drawing is arranged in the sound field so that the surface layer 27 side is directed to the sound source side, and the sound wave emitted from the sound field is incident on the surface layer 27 side. When a sound wave enters from the surface layer 27 side, the base material layer 21 vibrates due to a sound pressure difference between the front side (sound wave incident side) and the back side (back surface layer 28 side) of the base material layer 21. Here, in this embodiment, since it has the surface layer 27 and the back surface layer 28 which were formed with the nonwoven fabric, the surface layer 27 and the back surface layer 28 are against the movement of the air in the vicinity of the base material layer 21. It becomes resistance. For this reason, compared with the case where there is no surface layer 27 and the back surface layer 28, the energy of the sound wave is consumed more, and the sound absorption rate is improved than when the surface layer 27 and the back surface layer 28 are not provided. In the present embodiment, there is an air layer between the base material layer 21 and the front surface layer 27 and the back surface layer 28, and the vibrating portion 20B and the front surface layer 27 and the back surface layer 28 are not in contact with each other. The problem of deterioration does not occur.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. For example, the present invention may be implemented by modifying the above-described embodiment as follows.

In the present invention, the base material layer 21 may be a plate member having elasticity.
In the present invention, the shape of the air layer formed inside the sound absorber is not limited to a rectangular parallelepiped, and may be another shape.
In the first embodiment of the present invention, the fiber material may be different between the front surface layer 22 and the back surface layer 23. Also, in the third embodiment of the present invention, the front surface layer 27 and the back surface layer are also different. 28 may be made of different fiber materials.
In the first embodiment of the present invention, fibers may be planted on the base material layer 21 to form the surface layer 22 and the back surface layer 23, and the wool yarn may be applied to the front surface and the back surface of the base material layer 21. You may arrange | position and form the surface layer 22 and the back surface layer 23. FIG.
In the first embodiment of the present invention, the surface layer 22 and the back surface layer 23 may be formed by mixing and adhering or flocking a plurality of different types of fibers, or the third embodiment of the present invention. Also in the form, the front surface layer 27 and the back surface layer 28 may be formed of a nonwoven fabric obtained by mixing a plurality of different types of fibers.
Moreover, in 1st Embodiment of this invention, you may make it adhere | attach or plant a fiber only to either one surface of the surface of the base material layer 21, or a back surface.
In the third embodiment of the present invention, a breathable cloth woven with synthetic fibers may be used as the surface layer 27 and the back layer 28.

Moreover, also in 2nd Embodiment of this invention, a fiber may be planted or adhere | attached on the surface or back surface of the base material layer 21, and a fiber may be planted or adhered on both the front surface and the back surface.
In the second embodiment of the present invention, the powder 24 is not limited to zinc white starch, and may be other organic or inorganic powder such as corn starch, talc, silica, zinc white, or the like. Good.
In the second embodiment of the present invention, powders of a plurality of different materials may be mixed and sealed between the base material layer 21 and the sealing layer 25.
Moreover, in 2nd Embodiment of this invention, the distance between the base material layer 21 and the sealing layer 25 can be set arbitrarily. Further, the amount of the powder 24 can be arbitrarily set.

In the present invention, the shape of the side wall member 12 may be a cylindrical shape other than a square tube or a polygonal tube shape.
Further, in the present invention, the sound absorbers are not used alone, but a plurality of sound absorbers according to any of the above-described embodiments or modifications may be used as a group of sound absorbers.
In the sound absorber group, for each of the sound absorbers to be combined, the conditions for forming the sound absorber (for example, the thickness of the air layer, the tension applied to the material of the base material layer and the base material layer, the thickness of the surface layer and the back surface layer, The frequency of the sound that is absorbed may be varied by changing the material, the type of powder, and the like.

Further, in the present invention, when the sound absorber group is formed, not only the sound absorber group is formed by combining a plurality of the sound absorbers of any one of the above-described embodiments or modifications, but for example, in the first embodiment. Different types of sound absorbers may be combined into a sound absorber group, such as combining the sound absorber and the sound absorber according to the second embodiment, or combining three or more types of sound absorbers.
Further, when the sound absorber group is formed by combining different types of sound absorbers, a plurality of each type of sound absorbers may be provided.
Also in this sound absorber group, the sound absorber forming conditions may be different for each sound absorber to be combined, and the frequency of the sound to be absorbed may be different.

  Moreover, the sound absorber and the sound absorber group connecting the sound absorbers according to the present invention can be arranged in various acoustic chambers that control acoustic characteristics. Here, the various acoustic rooms include soundproof rooms, halls, theaters, listening rooms for audio equipment, living rooms such as conference rooms, spaces for various transportation equipment such as vehicles, and housings for speakers and musical instruments.

It is a schematic diagram of the external appearance of the sound absorber 1 which concerns on one Embodiment of this invention. It is the sectional view on the AA line of FIG. It is a schematic diagram of the external appearance of 1 A of sound absorbers which concern on 2nd Embodiment of this invention. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a schematic diagram of the external appearance of the sound-absorbing body 1B according to the third embodiment of the present invention. It is CC sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sound absorber, 10 ... Housing, 11 ... Bottom member, 12 ... Side wall member, 20, 20A, 20B ... Vibrating part, 21 ... Base material layer, 22 ... -Surface layer, 23 ... Back layer, 24 ... Powder, 25 ... Sealing layer, 27 ... Surface layer, 28 ... Back layer, 30 ... Air layer

Claims (10)

A housing having an opening and an internal space connected to the opening;
It has a base material layer formed in a film shape or a plate shape, and has a vibration part in which a plurality of fiber pieces are bonded to at least the front surface or the back surface of the base material layer,
A sound absorber in which the opening is closed by the vibration part. A housing having an opening and an internal space connected to the opening;
It has a base material layer formed in a film shape or a plate shape, and has a vibrating part in which a plurality of fiber pieces are planted on at least the front surface or the back surface of the base material layer,
A sound absorber in which the opening is closed by the vibration part. A housing having an opening and an internal space connected to the opening;
A base material layer formed in a film shape or a plate shape;
A sealing layer formed in a film shape;
Powder and
The opening is closed by the base material layer;
The sealing layer is separated from the base material layer by a predetermined distance toward the internal space so that a sealed space is formed by the sealing layer, the base material layer, and an inner wall forming the internal space of the housing. Arranged,
A sound absorber in which the powder is enclosed in the sealed space. A housing having an opening and an internal space connected to the opening;
A base material layer formed in a film shape or a plate shape;
A first fiber layer having air permeability;
A second fiber layer having air permeability,
The opening is closed by the second fiber layer;
The base material layer is disposed at a predetermined distance from the second fiber layer to the side opposite to the internal space direction so that a space is formed between the base material layer and the second fiber layer.
The first fiber layer is disposed at a predetermined distance from the base material layer to the side opposite to the internal space direction so that a space is formed between the first fiber layer and the base material layer. Sound absorber.   A sound absorber group in which a plurality of sound absorbers according to any one of claims 1 to 4 are combined. The sound absorber according to claim 1,
Furthermore, the sound absorber group which has at least one sound absorber as described in any one of Claim 2,3,4. A sound absorber according to claim 2,
Further, a sound absorber group having at least one sound absorber according to any one of claims 3 and 4. A sound absorber according to claim 3,
Furthermore, a sound absorber group having at least one sound absorber according to claim 4.   An acoustic chamber having the sound absorber according to any one of claims 1 to 4.   An acoustic chamber having the sound absorber group according to any one of claims 6 to 8.

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