JP5270420B2 - Sound absorbing structure - Google Patents

Description

  The present invention relates to a sound absorbing structure that can reduce sound from a sound source in a railway, road, or other place where sound is generated.

  Conventionally, in order to prevent noise from neighboring houses or public facilities, soundproof walls or the like as sound absorbing structures have been used around railway facilities and highways. Also, in a room such as a conference room or a concert hall, a sound absorbing structure is used to prevent sound leakage to an adjacent room or unnecessary interference of sound.

As such a sound absorbing structure, for example, the one described in Patent Document 1 is used. In this sound absorbing structure, the internal space of the box member in which a large number of small holes are formed on the outer surface is divided by a perforated plate. The perforated plate is sandwiched and held by a support frame having an outer shape along the internal space of the box member.
According to this configuration, the sound absorption effect can be increased and the weather resistance can be maintained high.

JP 2008-138505 A

  However, since the sound absorbing structure described in Patent Document 1 installs the porous plate inside the box member, an internal structure member such as a support frame is required. Therefore, the manufacturing cost is increased.

  In view of the above circumstances, an object of the present invention is to provide a sound absorbing structure that does not require an internal structural member and can exhibit a high sound absorbing effect in a wide frequency range.

  The sound absorbing structure according to the present invention has the following features to achieve the above object. In other words, the sound absorbing structure of the present invention has the following features alone or in combination as appropriate.

  The first feature of the sound absorbing structure according to the present invention for achieving the above object is a sound absorbing structure obtained by combining a plurality of sound absorbing panels capable of absorbing sound from a sound source, and comprising at least one sound absorbing structure. A first sound-absorbing panel having a predetermined sound-absorbing characteristic formed in a box shape having a plurality of through-holes in the surface plate; and a predetermined sound-absorbing characteristic formed in a box shape having a plurality of through-holes in at least one surface plate. And a second sound absorbing panel having different sound absorbing characteristics.

  According to this configuration, since the first sound absorbing panel and the second sound absorbing panel having different sound absorbing characteristics are combined, a high sound absorbing effect can be exhibited in a wide frequency range without arranging a structural member inside each sound absorbing panel. . Thereby, a sound absorbing structure that exhibits a high sound absorbing effect in a wide frequency range can be manufactured at low cost.

  The second feature of the sound absorbing structure according to the present invention is that the first sound absorbing panel has a plurality of through-holes as the surface plate so that the shape of the opening is different between one surface and the other surface. The second sound absorbing panel is a second sound absorbing panel in which a plurality of through holes are formed by the same method as the method of forming the through holes in the first sound absorbing panel as the surface plate. The second perforated plate is provided in the second sound absorbing panel so as to be opposite to the direction of the first perforated plate provided in the first sound absorbing panel.

According to this configuration, the shape of the opening is different between the surface of the first perforated plate facing the outside of the first sound absorbing panel and the surface of the second perforated plate facing the outside of the second sound absorbing panel. Thereby, the 1st sound absorption panel and the 2nd sound absorption panel can be distinguished easily based on the shape of the surface. As a result, it is possible to prevent a mistaken arrangement of the sound absorbing panel during the production of the sound absorbing structure.
Moreover, since a 1st perforated plate and a 2nd perforated plate can be formed by the same method, manufacture of a perforated plate can be performed efficiently.

  Further, a third feature of the sound absorbing structure according to the present invention is that the first porous plate and the second porous plate are formed by punching a plate, and the first porous plate is And the second perforated plate is provided so that the direction from the inner side to the outer side of the second sound absorbing panel is the punching direction. It is being done.

  According to this configuration, burrs are generated on the surface of the porous plate by punching, so that the surface shape is different between the front and back surfaces of the porous plate. Therefore, the first sound absorbing panel and the second sound absorbing panel can be distinguished by the presence or absence of the burr on the surface of the sound absorbing panel. As a result, it is possible to prevent mistakes in the arrangement of the sound absorbing panels by a simple method.

  In addition, a fourth feature of the sound absorbing structure according to the present invention is that the first sound absorbing panel has a plurality of through-holes as the surface plate and has a predetermined surface facing the outside of the first sound absorbing panel. A first perforated plate having a color, wherein the second sound absorbing panel has a plurality of through-holes as the surface plate and a color different from the predetermined color on a surface facing the outside of the second sound absorbing panel. It is providing the 2nd perforated board which has.

  According to this configuration, the first sound absorbing panel and the second sound absorbing panel can be easily distinguished from each other by appearance. For this reason, it is possible to prevent a mistaken arrangement of the sound absorbing panel when the sound absorbing structure is manufactured.

  ADVANTAGE OF THE INVENTION According to this invention, the sound absorption structure which can exhibit a high sound absorption effect in a wide frequency range can be manufactured at low cost.

The figure which shows the sound absorption structure which concerns on 1st Embodiment of this invention. The figure which shows the 1st sound absorption panel in the sound absorption structure shown in FIG. The figure which shows the 2nd sound absorption panel in the sound absorption structure shown in FIG. The figure which shows the sound absorption characteristic of the sound absorption structure shown in FIG. The figure which shows the sound absorption structure which concerns on 2nd Embodiment of this invention.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
<Overall configuration>
As shown in FIG. 1, the sound absorbing structure 1 according to the first embodiment of the present invention includes three first sound absorbing panels 2, three second sound absorbing panels 3, and a pair of pillar members 4 extending vertically. It has.
The sound absorbing structure 1 is formed by fitting the first sound absorbing panel 2 and the second sound absorbing panel 3 between a pair of pillar members 4 arranged at a predetermined interval. The first sound absorbing panel 2 and the second sound absorbing panel 3 are alternately arranged in the longitudinal direction of the column member 4. Moreover, the 1st sound absorption panel 2 and the 2nd sound absorption panel 3 are arrange | positioned so that a mutual side surface may closely_contact | adhere.

<Configuration of the first sound absorbing panel>
Fig.2 (a) is a perspective view which shows the 1st sound absorption panel 2 of the sound absorption structure 1, FIG.2 (b) is a X1-X1 cross-sectional schematic diagram of the 1st sound absorption panel 2 shown to Fig.2 (a). It is.
As shown to Fig.2 (a), the 1st sound absorption panel 2 is formed in the rectangular parallelepiped box shape, and several through-holes 21a are formed in one surface (surface plate 21) of six surfaces which form a box. Is formed.
The material of the first sound absorbing panel 2 is, for example, an aluminum plate or aluminum foil with good workability.

The through hole 21a is formed by punching the surface plate 21.
The surface plate 21 is punched from a surface facing the outside of the first sound absorbing panel 2 (hereinafter referred to as an outer surface) to a surface facing the inside (hereinafter referred to as an inner surface). Therefore, the shape of the opening portion of the through hole 21 a is different between the outer surface and the inner surface of the surface plate 21.
Specifically, as shown in FIG. 2 (b), burrs protruding toward the inside of the first sound absorbing panel 2 are formed at the periphery of the opening on the inner surface of the surface plate 21. On the other hand, no burr is formed on the outer surface of the surface plate 21, and the periphery of the opening is slightly depressed.

<Configuration of the second sound absorbing panel>
Fig.3 (a) is a perspective view which shows the 2nd sound absorption panel 3 of the sound absorption structure 1, FIG.3 (b) is X2-X2 cross-sectional schematic diagram of the 2nd sound absorption panel 3 shown to Fig.3 (a). It is.
As shown in FIG. 3 (a), the second sound absorbing panel 3 is formed in a rectangular parallelepiped box shape having the same dimensions as the first sound absorbing panel 2, and one of the six surfaces forming the box (surface plate) A plurality of through holes 31a are formed in 31).
The material of the second sound absorbing panel 3 is, for example, an aluminum plate or aluminum foil with good workability.

The through hole 31a is formed by punching from the inner surface to the outer surface of the second sound absorbing panel 3 in the surface plate 31, and the shape of the opening is different between the inner surface and the outer surface.
Specifically, as shown in FIG. 3 (b), burrs protruding outward from the second sound absorbing panel 3 are formed at the periphery of the opening on the outer surface. On the other hand, no burr is formed on the inner surface, and the periphery of the opening is recessed.

<Number and shape of through holes in sound absorbing panel>
The sound absorption coefficient standard of the road sound absorption panel is defined as 0.7 or more at the first frequency (400 Hz) and 0.8 or more at the second frequency (1 kHz), for example. That is, the sound absorption coefficient standard of the road sound absorption panel is defined by the sound absorption coefficient at two frequencies.
Therefore, the through-hole 21a of the first sound absorbing panel 2 is formed in the surface plate 21 so that the sound absorbing rate of the first sound absorbing panel 2 is maximized at 400 Hz (first frequency defined by the sound absorbing rate reference). That is, the hole diameter and the aperture ratio of the through hole 21a are set so that the sound absorption coefficient is maximized at 400 Hz.
The first sound absorbing panel 2 need not have a sound absorption coefficient of 0.8 or more at 1 kHz.

Here, the “sound absorption rate” means a ratio of sound energy not reflected to incident sound energy.
The “aperture ratio” means the ratio of the area of the portion opened by the plurality of through holes 21 a to the area of the surface plate 21.

On the other hand, the through hole 31a of the second sound absorbing panel 3 is formed in the surface plate 31 so that the sound absorption coefficient of the second sound absorbing panel 3 becomes maximum at 1 kHz (second frequency defined by the sound absorption coefficient reference). That is, the hole diameter and the aperture ratio of the through hole 31a are set so that the sound absorption coefficient becomes maximum at 1 kHz.
The second sound absorbing panel 3 does not have to have a sound absorption coefficient of 0.7 or more at 400 Hz.

<Sound absorption characteristics of sound absorbing structure 1>
The sound absorbing structure 1 according to the present embodiment is formed by alternately arranging the first sound absorbing panel 2 and the second sound absorbing panel 3 in which the through holes 21a and the through holes 31a are formed in the surface plate as described above. The characteristics are shown in FIG.
In FIG. 4, the sound absorption characteristics of the sound absorbing structure (Comparative Example 1) in which only the first sound absorbing panels 2 are arranged and the sound absorbing characteristic of the sound absorbing structure (Comparative Example 2) in which only the second sound absorbing panels 3 are arranged. The characteristics are also shown.

As shown in FIG. 4, the sound absorption rate of the sound absorbing structure 1 according to the present embodiment is about 0.8 at 400 Hz and about 0.9 at 1 kHz. That is, it satisfies the sound absorption coefficient standard (0.7 or more at 400 Hz and 0.8 or more at 1 kHz) of the road sound absorbing panel. The sound absorption rate of the sound absorbing structure 1 is 0.8 or more in the range of 400 Hz to 1 kHz.
On the other hand, in the sound absorption structure of Comparative Example 1, although the sound absorption rate at 400 Hz is 0.7 or more, the sound absorption rate at 1 kHz is about 0.3, which does not satisfy the sound absorption rate standard of the road sound absorption panel. Similarly, in the sound absorbing structure of Comparative Example 2, although the sound absorption rate at 1 kHz is 0.8 or more, the sound absorption rate at 400 Hz is about 0.3, which does not satisfy the sound absorption rate standard of the road sound absorption panel. .

<Effect of the sound absorbing structure 1>
As described above, the sound absorbing structure 1 includes the following two types of sound absorbing panels.
(1) A first sound absorbing panel 2 which is formed in a box shape in which a plurality of through holes 21a are formed in the surface plate 21 and has a sound absorbing characteristic that maximizes the sound absorption coefficient at 400 Hz in all frequency regions.
(2) The second sound absorbing panel 3 which is formed in a box shape in which a plurality of through holes 31a are formed in the surface plate 31 and has a sound absorbing characteristic that maximizes the sound absorption coefficient at 1 kHz in the entire frequency region.
And in the sound-absorbing structure 1, the 1st sound-absorbing panel 2 and the 2nd sound-absorbing panel 3 have each side surface (outer surface) in the state which orient | assigned the surface board 21 and the surface board 31 to the same direction (sound source side). They are in contact and arranged alternately in one direction.

According to this configuration, since two sound absorbing panels having different sound absorbing characteristics (the first sound absorbing panel 2 and the second sound absorbing panel 3) are combined, a wide frequency range can be obtained without disposing a structural member inside each sound absorbing panel. High sound absorption effect. In the present embodiment, the sound absorption coefficient is high in the frequency range of 400 Hz to 1 kHz.
Moreover, since the 1st sound absorption panel 2 and the 2nd sound absorption panel 3 are arrange | positioned so that it may mutually contact on an outer surface, they will be mutually supported between sound absorption panels. Thereby, the number of other structural members for fixing the position of each sound absorbing panel can be reduced.
As a result, the manufacturing cost of the sound absorbing structure 1 can be suppressed.

Further, the first sound absorbing panel 2 includes a surface plate 21 (first perforated plate) having a plurality of through holes 21a formed so that burrs are generated on the inner surface and burrs are not generated on the outer surface. I have. The through hole 21 a is formed by punching the surface plate 21. And the surface board 21 of the 1st sound absorption panel 2 is installed in the said 1st sound absorption panel 2 so that it may become the direction where the burr | flash of the opening edge part of the through-hole 21a is located inside a sound absorption panel.
The second sound absorbing panel 3 includes a surface plate 31 (second perforated plate) in which a plurality of through holes 31a are formed by a punching method. The surface plate 31 of the second sound absorbing panel 3 is arranged so that the direction in which the surface plate 21 of the first sound absorbing panel is installed on the first sound absorbing panel 2 is reversed, that is, the burr is outside the sound absorbing panel. It is installed in the second sound absorbing panel 3 so as to be oriented in the direction.

According to this configuration, the first sound absorbing panel 2 and the second sound absorbing panel 3 can be easily distinguished by checking the presence or absence of burrs exposed on the outer surface of the sound absorbing panel by tactile sensation. Therefore, it is possible to prevent the arrangement order of the sound absorbing panels from being mistaken when the sound absorbing structure 1 is manufactured.
Moreover, since a through-hole can be formed in the surface plate 21 and the surface plate 31 by the same construction method (punching), the production of the porous plate can be performed efficiently.

Further, in the first sound absorbing panel 2, the surface plate 21 is provided such that the direction from the outside to the inside of the first sound absorbing panel 2 is the punching direction of the through hole 21 a.
On the other hand, in the second sound absorbing panel 3, the surface plate 31 is provided such that the direction from the inner side to the outer side of the second sound absorbing panel 3 is the punching direction of the through hole 31a.

  According to this structure, the 1st sound absorption panel 2 and the 2nd sound absorption panel 3 can be distinguished using the burr | flash produced by punching. As a result, it is possible to prevent mistakes in the arrangement of the sound absorbing panels with a simple method.

(Second Embodiment)
As shown in FIG. 5, the sound absorbing structure 1 </ b> A according to the second embodiment of the present invention has the surface plate 21 of the first sound absorbing panel 2 on the outer surface of the surface plate 31 in the second sound absorbing panel 3 of the first embodiment. The second embodiment is different from the first embodiment in that a predetermined color different from the color of the outer surface is attached. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  In the sound absorbing structure 1A, the first sound absorbing panel 2 has a white color on the outer surface of the surface plate on which the through holes are formed, and the second sound absorbing panel 3 ′ is a surface plate on which the through holes are formed. The color of the outer surface is gray.

  According to this configuration, the first sound absorbing panel 2 and the second sound absorbing panel 3 ′ can be easily distinguished from each other by appearance. Therefore, it is possible to prevent a mistake in arrangement of the sound absorbing panel at the time of manufacturing the sound absorbing structure 1A.

  In the second embodiment, since the first sound absorbing panel 2 and the second sound absorbing panel 3 ′ can be distinguished by visual recognition, the outer surface burrs on the surface plate in which the through holes are formed are removed. There may be.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

  For example, the present invention is not limited to the case where two types of sound absorbing panels are alternately arranged, and the sound absorbing structure may be configured by repeatedly arranging three or more types of sound absorbing panels in a predetermined order.

  Moreover, in this embodiment, although the inside of the 1st sound absorption panel 2 and the 2nd sound absorption panel 3 is all empty, one porous board is inserted in the inside of a sound absorption panel, and the internal structure of a sound absorption panel is carried out. A two-layer structure may be used, or two or more perforated plates may be inserted into the sound-absorbing panel to form an internal structure having three or more layers. In particular, the manufacturing cost can be most suppressed by emptying the interior of the sound absorbing panel as in this embodiment.

  The present invention can reduce sound from a sound source in a railway, road, or other place where sound is generated.

1, 1A Sound absorbing structure 2 First sound absorbing panel 21 Surface plate (first perforated plate)
3 Second sound absorbing panel 31 Surface plate (second perforated plate)

Claims (3)

A sound absorbing structure formed by combining a plurality of sound absorbing panels capable of absorbing sound from a sound source,
A first sound absorbing panel formed in a box shape having a plurality of through holes in at least one surface plate, and having a predetermined sound absorbing characteristic;
A second sound absorbing panel formed in a box shape having a plurality of through holes in at least one surface plate, and having a sound absorbing characteristic different from the predetermined sound absorbing characteristic;
Equipped with a,
The first sound absorbing panel has, as the surface plate, a first perforated plate in which a plurality of through holes are formed so that the shape of the opening is different between one surface and the other surface,
The second sound absorbing panel includes, as the surface plate, a second perforated plate in which a plurality of through holes are formed by the same method as the method of forming the through holes in the first sound absorbing panel,
Such that the front and back opposite to the installation has been the first perforated plate orientation to the first sound absorbing panel, the sound absorbing structure the second perforated plate that is disposed on the second sound absorbing panel. The first perforated plate and the second perforated plate are those in which through holes are formed by punching the plate,
The first perforated plate is provided such that a direction from the outside to the inside of the first sound absorbing panel is a punching direction,
The second perforated plate is provided such that a direction from the inner side to the outer side of the second sound absorbing panel is a punching direction.
The sound absorbing structure according to claim 1 . The first sound absorbing panel includes a first perforated plate having a predetermined color on a surface facing the outside of the first sound absorbing panel while a plurality of through holes are formed as the surface plate.
The second sound absorbing panel includes, as the surface plate, a second perforated plate having a color different from the predetermined color on a surface facing the outside of the second sound absorbing panel while a plurality of through holes are formed.
The sound absorbing structure according to claim 1 or 2 .

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