WO2008053997A1

WO2008053997A1 - Sound absorbing structure

Info

Publication number: WO2008053997A1
Application number: PCT/JP2007/071426
Authority: WO
Inventors: Takahiro Yamada; Ichiro Yamagiwa; Toshimitsu Tanaka; Masaji Horio; Noritaka Oomori; Tosiyasu Nakahara; Wataru Ishihara; Hiroshi Matsuda
Original assignee: Kabushiki Kaisha Kobe Seiko Sho; Shinko Kenzai Ltd.
Priority date: 2006-11-02
Filing date: 2007-11-02
Publication date: 2008-05-08
Also published as: JP2013047858A; JP5308006B2; JP5492972B2; TW200837248A; JP2008138505A

Abstract

In a sound insulating wall (100), the inner space of a box member (150) having, in at least one face (160), a large number of small holes (110) is partitioned into spaces by perforated plates (310, 320). Further, support frames (210, 220, 230) for holding the perforated plates (310, 320) have the outline along the inner space of the box member (150).

Description

Specification

Sound absorbing structure

Technical field

The present invention relates to a sound absorbing structure that can reduce sound from a sound source in railways, roads, and other places where sound is generated.

Background art

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 rooms such as conference rooms and concert halls, sound absorbing structures are used to prevent sound leakage into adjacent rooms or unwanted interference of sound!

For example, Patent Document 1 discloses a frame structure of a soundproof panel and a soundproof panel having the frame structure. In the soundproof panel described in Patent Document 1, even when a load from a vehicle collides with the soundproof panel in a traffic disaster, the soundproof panel is unlikely to cause the load to pass through the soundproof panel or to scatter components. It aims to provide a frame structure.

[0004] The structure of the soundproof panel described in Patent Document 1 is a rectangular soundproof panel in which a frame is formed using a frame material around a soundproof plate having sound insulation properties, and the bending strength of the facing frame material is substantially the same. It is what. As a result, when the load dropped from the vehicle hits, the opposing frame members are deformed to the same extent, so that it is possible to prevent the load from passing through the soundproof panel. In addition, even when the retaining material is used for retaining, the load concentrates on the retaining material on the one side of the frame material, so that the retaining material can be prevented from being broken and scattered and the soundproof plate can be prevented from being damaged. An effect is obtained.

On the other hand, Patent Document 2 discloses a panel sound absorbing device. In the structure of the sound absorbing device described in Patent Document 2, a number of punchings are applied to the metal front and back plates, and a rough cloth such as cold water is laid on the back surface of the front and back plates. In a sound absorbing device that uses a single sound absorbing plate or two sound absorbing plates, with a sound absorbing plate connected to a metal frame and filled with glass wool or rock wool in an inner hollow part surrounded by a gap. In the case of a single sheet, a vertically long air layer is formed between other panels and walls, and the end face is closed and connected with a metal side frame without gaps. Opposite to each other, the air layer portion is formed vertically between the back plates, and the end surfaces are closed and connected with a metal side frame without gaps.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-52380

Patent Document 2: JP-A-62-079018

Disclosure of the invention

Problems to be solved by the invention

[0007] However, the soundproof panel described in Patent Document 1 cannot effectively enhance the soundproofing force required during normal times, which is effective for lack of strength during a disaster. Moreover, since a member is fixed inside the soundproof panel, manufacturing is difficult.

[0008] On the other hand, in the sound absorbing device described in Patent Document 2, the inner hollow portion is filled with glass wool material and the like, and it is necessary to uniformly fill the glass wool material into the sound absorbing device. Manufacturing technology is required. In addition, it is necessary to position the sound-absorbing plate at the time of manufacture, which makes it difficult to manufacture.

[0009] Further, in the soundproof panel described in Patent Document 1 and the sound absorbing device described in Patent Document 2, it is difficult to obtain a high sound attenuation effect in a wide frequency band. In other words, actual noise depends on sound in a wide frequency band. Therefore, sound absorption using only glass wool described in Patent Document 2 is not able to reduce sound in a wide frequency range with high weather resistance and stability.

[0010] An object of the present invention is to provide a sound absorbing structure that is easy to assemble, has a high sound absorbing effect, and has weather resistance.

Another object of the present invention is to provide a sound absorbing structure that has high weather resistance and can stably reduce sound in a wide frequency band.

Means for solving the problem

[0012] (1)

A sound absorbing structure according to the present invention is a sound absorbing structure capable of absorbing sound from a sound source, and includes a box member having a porous surface with a large number of openings on at least one surface, A perforated plate having an opening and separating the inner space of the box member into a plurality of spaces; and a plurality of support frames sandwiching the perforated plate and having a force and an outer shape along the inner space of the box member. The plurality of support frames and the multi-hole plate are unitized by sandwiching the porous plate with a plurality of support frames.

[0013] In the sound absorbing structure according to the present invention, the internal space of the box member having a porous surface having a large number of openings on at least one surface has one or a plurality of perforated plates having a large number of openings. Is separated into a plurality of spaces. The plurality of support frames that sandwich the one or more perforated plates have an outer shape along the internal space of the box member.

[0014] In this case, the box member constituting the sound absorbing structure is unitized by sandwiching the perforated plate with a plurality of support frames, so that the unit can be easily put into the internal space of the box member in the manufacturing process. can do. As a result, the sound absorbing structure can be easily manufactured, and the force S for reducing the positioning work for fixing the perforated plate to a predetermined position in the internal space of the box member can be reduced. Accordingly, the sound absorbing structure can be easily assembled. In addition, by being unitized, each internal space inside the unit is kept airtight except for the opening of the perforated plate, so that the sound from the sound source can be effectively reduced. In addition, since the members having weather resistance are appropriately assembled, the sound resistance of the sound absorbing structure according to the present invention can be maintained high, and the structure of the sound absorbing structure does not change over a long period of time. Therefore, the sound absorption performance does not deteriorate even after long-term use.

[0015] (2)

The box member may be a rectangular parallelepiped, the porous surface may be disposed to face the sound source, and the plurality of support frames may be formed so that the porous plate is disposed in parallel to the porous surface.

In this case, the sound from the sound source efficiently passes through the porous surface of the box member, and the sound is absorbed by the porous plate sandwiched between the plurality of support frames. As a result, the sound from the sound source can be absorbed efficiently, and the sound can be reduced efficiently.

[0017] (3)

The perforated plate is composed of a plurality of perforated plates, and a plurality of perforated plates are individually arranged in a gap formed by stacking a plurality of support frames, and the plurality of perforated plates and the plurality of support frames are united. Unit member is formed by being assembled, and the unit member is stored in the box member. In addition, a plurality of support frames may be formed so that the plurality of perforated plates do not contact the inner peripheral surface of the box member.

In this case, the plurality of perforated plates are sandwiched between the plurality of support frames to form a unit, and the unitized member can be easily accommodated in the box member. Further, since the plurality of perforated plates do not contact the inner peripheral surface of the box member, damage to the perforated plates during production can be prevented. In addition, when the perforated plate and the box member are formed of different metal material forces, it is possible to prevent electric corrosion. Furthermore, by being unitized, each internal space inside the unit is kept airtight except for the opening of the perforated plate, so that the sound from the sound source can be effectively reduced.

[0019] (4)

The plurality of support frames are preferably made of non-conductors.

[0020] In this case, since the plurality of support frames are made of a non-conductor, even when the porous plate and the box member are made of a highly rigid conductor from the viewpoint of sound absorption, the gap between the porous plate and the box member There is no risk of direct contact. Furthermore, contact between the perforated plate and a metal such as a screw when fixing the box member and the support frame can be prevented. As a result, electrolytic corrosion does not occur between the perforated plate and the box member, and durability and weather resistance can be improved. As a result, sound absorption performance can be maintained for a long time.

[0021] (5)

The plurality of support frames are preferably made of resin.

In this case, since the plurality of support frames are made of resin, the support frames can be formed at low cost. Further, even when the perforated plate and the box member are made of a conductor, there is no possibility that the perforated plate and the box member are in direct contact with each other. Furthermore, contact between the perforated plate and a metal such as a screw when the box member and the support frame are fixed can be prevented. As a result, electrolytic corrosion does not occur between the perforated plate and the box member, and durability and weather resistance can be improved. As a result, the sound from the sound source can be efficiently reduced over a long period of time.

[0023] (6)

The plurality of support frames may have the same thickness in the stacking direction.

[0024] In this case, by unifying the thicknesses of the plurality of support frames, the intervals in the perforated plate are equal. Thus, cost reduction and ease of manufacture can be realized.

[0025] (7)

The plurality of support frames may have a width in a direction perpendicular to the stacking direction that is half or less of a wavelength from the sound source.

In this case, since the width in the direction perpendicular to the stacking direction is set to ½ or less of the wavelength from the sound source, it is possible to prevent the sound from spreading after passing through the perforated plate. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0027] (8)

The perforated surface and the perforated plate may be formed so that the aperture ratios of the openings in the perforated surface and the perforated plate are different, and the aperture ratio of the perforated surface and the perforated plate becomes smaller as the sound source force increases.

[0028] In this case, since the porous surface and the porous plate are arranged so that the aperture ratio of the opening decreases as the distance from the sound source increases, the sound of a wide frequency band from the sound source is gradually and gradually increased. It can be effectively reduced.

[0029] (9)

At least one of the porous surface and the porous plate satisfies the relationship y ^ O. 0086x + 0. 0076, where X is the thickness divided by the hole diameter of the opening, and y is the opening ratio of the opening ridge. It may be formed as follows.

[0030] (10)

The perforated plate is composed of a plurality of perforated plates, and at least one of the perforated surface and the plurality of perforated plates arranged at the farthest position from the sound source satisfies the relationship y O. 0086χ + 0.00 It may be formed.

[0031] (11)

A sound attenuating member, the sound attenuating member being disposed in at least one of a plurality of spaces separated by a plurality of support frames and a perforated plate, the sound attenuating member, the plurality of supports, and the The perforated plate may be unitized.

[0032] In this case, since the sound attenuating member is arranged and unitized in at least one of the plurality of spaces separated by the plurality of support frames and the perforated plate, the sound absorbing structure can be easily formed. The sound of the sound source can be further effectively reduced as compared with the case of using only the perforated plate.

[0033] (12)

The sound attenuating member may be a porous material force.

In this case, since the sound attenuating member is made of a porous material, the force S can be reduced more effectively to reduce the sound of the sound source.

[0035] (13)

The sound attenuating member may be made of a nonwoven fabric.

[0036] In this case, since the sound attenuating member is made of non-woven fabric, the force S can be reduced more effectively to reduce the sound of the sound source.

[0037] (14)

The sound attenuating member may be made of glass wool or PET (Poly Ethylene Terephthalate) based fiber material.

[0038] In this case, even if the sound attenuating member is made of glass wool or PET fiber material, glass wool or PET fiber material is arranged in the space, respectively. Compared to the case where glass wool or PET fiber material is placed on the surface, the bias of the sound attenuating member due to its own weight can be minimized. Further, even when the amount of the sound attenuating member is small, a sound absorbing structure by the perforated plate can be expected, and further sound attenuating effect can be achieved by adding the sound attenuating member. Therefore, sound from the sound source can be effectively reduced in the sound absorbing structure.

[0039] (15)

The opening can be a small hole!

[0040] In this case, since the opening is made of a small hole, the sound of the sound source can be effectively reduced.

[0041] (16)

The opening may be a circular hole.

[0042] Since the opening is formed of a circular hole, it can be manufactured easily and at low cost.

[0043] (17)

The opening may be a slit-shaped hole. [0044] In this case, since the opening is made of a slit-shaped hole, it is possible to reduce the sound S from the sound source. The slit shape includes a louver fin shape.

[0045] (18)

The opening may be formed from a deformed hole.

[0046] In this case, since the opening is formed of an irregularly shaped hole, a shape having a sharp angle is included in a part of the hole such as a cross-shaped hole formed by embossing, and is manufactured easily and at low cost. That's the power S.

[0047] (19)

The perforated plate is preferably made of an aluminum member!

[0048] In this case, since the porous plate is made of an aluminum member, it can be manufactured at low cost.

It is easy to process and many fine holes can be formed. In addition, recyclability is improved by using aluminum members.

[0049] (20)

The box member is preferably made of an aluminum member.

[0050] In this case, since the box member is made of an aluminum member, it can be easily processed and can form a large number of minute holes. In addition, the use of aluminum members improves recyclability.

[0051] (21)

The opening is preferably formed by embossing.

[0052] In this case, since the opening in the perforated plate is formed by embossing, the micropores can be formed uniformly. Moreover, since the rigidity of the porous plate can be increased by the shape of the peaks and valleys during embossing, the rigidity of the porous plate itself can be increased even when a thin porous plate is used. Ability to increase work efficiency in manufacturing In addition, when the perforated plate is formed by embossing, if it is held by a plurality of support frames, extremely small gaps can be formed between the perforated plate and the plurality of support frames. You can expect.

[0053] (22)

The opening may be formed by punching. [0054] In this case, even if a thick plate material is used, a large number of openings can be formed by punching.

[0055] (23)

The perforated plate may have a damping structure.

[0056] In this case, since the perforated plate itself has a damping structure, vibration due to resonance of the perforated plate can be reduced, and the relative speed difference between the perforated plate and air can be increased to prevent a decrease in sound absorption performance. it can. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0057] (24)

The damping structure may be coated on the perforated plate! /

[0058] In this case, the porous plate is made of a composite material by coating the porous plate.

As a result, the vibration due to the resonance of the perforated plate can be reduced and the relative speed difference between the perforated plate and air can be increased to prevent the sound absorption performance from being lowered. As a result, the sound absorbing structure can effectively reduce the sound source force and other sounds.

[0059] (25)

The perforated plate may be composed of at least two perforated plates arranged in contact with each other.

[0060] In this case, by arranging the two perforated plates in contact with each other, the perforated plate itself has vibration damping properties, so that vibration due to resonance of the perforated plate is reduced, and the relative speed difference between the perforated plate and air is reduced. It is possible to prevent the deterioration of the sound absorption performance. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0061] (26)

The perforated plate can be made of a vibration-damping plate! /.

[0062] In this case, since the perforated plate itself has vibration damping properties, vibration due to resonance of the perforated plate can be reduced, and the relative speed difference between the perforated plate and air can be increased to prevent a decrease in sound absorption performance. . As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0063] (27)

It is preferable that the box member has a drain hole penetrating the internal space and the outside!

[0064] In this case, since the drain hole is formed, it is installed outdoors and the inside of the box member Even if there is water intrusion due to rain, etc., the drain hole can also drain rain water to prevent electric corrosion that occurs inside the box parts, and the sound absorption performance is low due to clogging due to accumulated water. There is no lowering.

[0065] (28)

The sound absorbing structure according to the present invention is a sound absorbing structure capable of absorbing sound from a sound source, and is provided with a first plate member having a large number of openings and a first plate member facing the first plate member. 2 plate members and one or more perforated plates having a large number of openings and disposed between the first plate member and the second plate member, the first plate member and the perforated plate The aperture ratios of the first plate member and the multi-hole plate are different, the first plate member, the perforated plate, and the second plate member are arranged in this order from the sound source, and the first plate member and the perforated plate move away from the sound source. It is formed so that the aperture ratio becomes small.

[0066] In this case, the first plate member and the perforated plate are arranged so that the aperture ratio of the opening decreases as the distance from the sound source increases! /. Sound can be reduced step by step and effectively.

[0067] (29)

At least one of the first plate member and the perforated plate has a value obtained by dividing the plate thickness by the hole diameter of the opening portion as X, and the opening ratio of the opening portion as y, and a relationship of y O. 0086x + 0.00. It may be formed so as to satisfy.

[0068] (30)

The perforated plate is composed of a plurality of perforated plates, and at least one of the plurality of perforated plates arranged at the farthest position from the sound source is formed so as to satisfy the relationship y O. 0086χ + 0.00. May be.

[0069] (31)

A sound attenuating member may be further included, and the sound attenuating member may be disposed at least at one position between the first plate member and the perforated plate, between the perforated plate, and between the perforated plate and the second plate member.

[0070] In this case, since the sound attenuating member is disposed at least at one position between each of the first plate member, the perforated plate and the second plate member, only the first plate member, the perforated plate and the second plate member are provided. Compared to the case, the sound of the sound source can be further effectively reduced. [0071] (32)

The sound attenuating member may be a porous material force.

[0072] In this case, since the sound attenuating member is made of a porous material, the force S can be reduced more effectively to reduce the sound of the sound source.

[0073] (33)

The sound attenuating member may be made of a nonwoven fabric.

[0074] In this case, since the sound attenuating member is made of non-woven fabric, the force S can be reduced more effectively to reduce the sound of the sound source.

[0075] (34)

[0076] In this case, even if the sound attenuating member is made of glass wool or PET fiber material, glass wool or PET fiber material is arranged in the space, respectively. Compared to the case where glass wool or PET fiber material is placed on the surface, the bias of the sound attenuating member due to its own weight can be minimized. Further, even when the amount of the sound attenuating member is small, a sound absorbing structure by the perforated plate can be expected, and further sound attenuating effect can be achieved by adding the sound attenuating member. Therefore, sound from the sound source can be effectively reduced in the sound absorbing structure.

[0077] (35)

The opening can be a small hole!

[0078] In this case, since the opening is formed of a small hole, the sound of the sound source can be effectively reduced.

[0079] (36)

The opening may be a circular hole.

[0080] Since the opening is formed of a circular hole, it can be manufactured easily and at low cost.

[0081] (37)

The opening may be a slit-shaped hole.

[0082] In this case, since the opening is formed of a slit-shaped hole, it is possible to reduce the sound S from the sound source. The slit shape includes a louver fin shape. [0083] (38)

The opening may be formed from a deformed hole.

[0084] In this case, since the opening is formed of an irregularly shaped hole, a shape having an acute angle is also included in a part of the hole such as a cross-shaped hole formed by embossing, which is easily manufactured at low cost. That's the power S.

(39)

The perforated plate is preferably made of an aluminum member!

In this case, since the perforated plate is made of an aluminum member, it can be manufactured at a low cost and can be easily processed to form a large number of minute holes. In addition, recyclability is improved by using aluminum members.

(40)

The first plate member and the second plate member are preferably made of aluminum members!

[0086] In this case, since the first plate member and the second plate member are made of an aluminum member, they can be manufactured at a low cost and can be processed easily and a large number of minute holes can be formed. In addition, recyclability is improved by using an aluminum member.

[0087] (41)

The opening is preferably formed by embossing.

[0088] In this case, since the opening in the perforated plate is formed by embossing, it is possible to uniformly form micropores. Moreover, since the rigidity of the porous plate can be increased by the shape of the peaks and valleys at the time of embossing, the rigidity of the porous plate itself can be increased even when a thin porous plate is used. The ability to improve work efficiency in manufacturing

[0089] (42)

The opening may be formed by punching.

In this case, even if a thick plate material is used, a large number of openings can be formed by punching.

[0091] (43)

The perforated plate may have a damping structure. [0092] In this case, since the perforated plate itself has a damping structure, vibration due to resonance of the perforated plate can be reduced, and a relative speed difference between the perforated plate and air can be increased to prevent a decrease in sound absorption performance. it can. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0093] (44)

The damping structure may be coated on the perforated plate! /

In this case, the porous plate is made of a composite material by applying a coating treatment to the porous plate.

[0095] (45)

[0096] In this case, by arranging the two perforated plates in contact with each other, the pair of perforated plates themselves have vibration damping properties. Therefore, vibration due to resonance of the perforated plates is reduced, and the relative perforation between the perforated plates and the air is reduced. The speed difference can be increased to prevent a decrease in sound absorption performance. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0097] (46)

The perforated plate can be made of a vibration-damping plate! /.

[0098] In this case, since the perforated plate itself has vibration damping properties, vibration due to resonance of the perforated plate can be reduced, and the relative speed difference between the perforated plate and air can be increased to prevent a decrease in sound absorption performance. . As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0099] (47)

The sound absorbing structure according to the present invention includes a housing having a surface having a first hole, a first frame, a second frame, and a second hole formed between the first frame and the second frame. A unit member that is accommodated in the housing, and the surface of the housing and the intermediate member face each other.

Brief Description of Drawings

[0100] [FIG. 1] A schematic perspective view showing an example of a soundproof wall using a sound absorbing structure.

FIG. 2 is a schematic explanatory diagram showing an example of a plurality of units. FIG. 3 is a schematic cross-sectional view showing an example of a cross section in which a plurality of units are housed in a box member.

[Fig.4] Schematic perspective view of a part of the noise barrier.

[Fig. 5] (a) is a schematic sectional view of a porous plate, (b) is a schematic plan view of the porous plate.

[Fig. 6] (a) is a schematic sectional view of a porous plate, (b) is a schematic plan view of the porous plate.

[Fig. 7] Schematic diagram for explaining the hole ratio of the surface and the aperture ratio of the perforated plate

[Fig. 8] Schematic diagram for explaining the aperture ratio of the perforated plate

FIG. 9 is a schematic diagram for explaining a state in which a sound attenuating member is attached to a perforated plate.

FIG. 10 is a schematic diagram for explaining a state in which a sound attenuating member is attached to a perforated plate.

FIG. 11 is a schematic sectional view for explaining a soundproof wall including a sound attenuating member.

[Fig. 12] Schematic diagram for explaining an example of a sound barrier

FIG. 13 is a schematic diagram for explaining the effect of the soundproof wall in FIG.

FIG. 14 is a schematic sectional view showing an example of a section of a sound absorbing structure according to a second embodiment.

[Fig. 15] (a) is a schematic cross-sectional view of a porous plate, (b) is a schematic plan view of the porous plate.

[Fig. 16] (a) is a schematic cross-sectional view of a porous plate, (b) is a schematic plan view of the porous plate.

FIG. 17 is a schematic cross-sectional view for explaining a sound absorbing structure that further includes a sound attenuating member in the sound absorbing structure.

FIG. 18 is a schematic cross-sectional view for explaining a state in which a sound attenuating member is attached to a perforated plate.

100 wall structure, sound absorbing structure

150 box member, second plate member

160, first plate member

180 drain hole

210 1st support frame

220 Second support frame

230 3rd support frame

240 4th support frame

200 units

310, 320, 330 31 1, 321 mountain shape

312, 322 Valley shape

318, 328 sound attenuating member

510, 520, 530 sound attenuation member

BEST MODE FOR CARRYING OUT THE INVENTION

[0102] Hereinafter, first and second embodiments according to the present invention will be described. In the first embodiment, a case where the sound absorbing structure is applied to a soundproof wall structure will be described.

(First embodiment)

[0103] FIG. 1 is a schematic perspective view showing an example of a soundproof wall using a sound absorbing structure.

[0104] The soundproof wall 100 of Fig. 1 is composed of a box member 150 in which a space is formed. In the box member 150, a large number of small holes 110 are formed in the surface 160. In the present embodiment, a large number of small holes 110 are formed by punching. These many small holes 110 have, for example, a hole diameter of 0.3 mm or more and 3 mm or less, and an opening ratio of the surface 160 of 10% or less. Further, the box member 150 is made of a steel plate (for example, a highly weather-resistant steel plate). As a result, the manufacturing cost of the box member 150 can be kept low.

In addition, as shown in FIG. 1, a plurality of units 200 are provided in the internal space of the box member 150. Details of the plurality of units 200 will be described later. In FIG. 2, for the sake of explanation, the upper part of the box member 150 is shown open, but in actual use, all six surfaces are surrounded. Further, the surface 160 may be screwed as a lid portion and may be formed so as to be removable. In this case, the screw is preferably made of the same member as the box member 150.

Further, in the present embodiment, the force with which box member 150 is made of a steel plate is not limited to this, and it may be made of any other metal processed member, resin, or the like. Further, the force that is formed by punching a large number of small holes 110 in the surface 160 is not limited to this, and may be formed by embossing or other arbitrary processing. Next, FIG. 2 is a schematic explanatory diagram showing an example of the plurality of units 200. As shown in FIG. FIG. 2 shows a state where one unit 200 is pulled out from the box member 150 and the internal structure of the unit 200 is separated.

As shown in FIG. 2, the unit 200 includes a first frame member 210, a second frame member 220, and a third frame member 2

30 and perforated plate 310 and perforated plate 320.

As shown in FIG. 2, the porous plate 310 is sandwiched between the first frame member 210 and the second frame member 220, and the porous plate 320 is sandwiched between the second frame member 220 and the third frame member 230. Is done. The first frame member 210, the second frame member 220, and the third frame member 230 have substantially the same outer size as the area of the internal space of the box member 150.

[0110] In the present embodiment, the force S described in the case of the first frame member 210, the second frame member 220, and the third frame member 230 is not limited to this. It may be composed of a plurality of frame members. In addition, it is preferable that the unit 200 has a shape that occupies the internal space of the box member 150.

Next, FIG. 3 is a schematic cross-sectional view showing an example of a cross-section in a state where a plurality of units 200 are housed in a box member 150.

As shown in FIG. 3, the outer periphery of the porous plate 310 is sandwiched between the first frame member 210 and the second frame member 220, and the second frame member 220 and the third frame member 230 are The outer periphery of the perforated plate 320 is sandwiched.

Further, by sandwiching the porous plate 310 and the porous plate 320 in the first frame member 210, the second frame member 220, and the third frame member 230, the porous plate 310 and the porous plate 320 become the box member 150. It is formed so as not to come into contact with the surface in the internal space.

Further, as shown in FIG. 3, the thickness of the first frame member 210 is L1, the thickness of the second frame member 220 is L2, and the thickness of the third frame member 230 is L3. These thicknesses LI, L2 and L3 are determined by the wavelength of the sound wave to be absorbed among the sound waves coming from the sound source, and the thickness, hole diameter and aperture ratio of the perforated plate. Therefore, in the present embodiment, the values of the thicknesses LI, L2 and L3 are different from each other. However, the present invention is not limited to this, and any thickness may be used as long as the two thicknesses are the same value. LI, L2, and L3 may be the same numerical value. Further, the perforated plate 310 and the perforated plate 320 are not limited to the case where they are arranged completely in parallel, and are substantially flat. If they are rows, they may be facing each other at an arbitrary angle, such as when they are arranged in parallel.

Next, the first frame member 210, the second frame member 220, and the third frame member 230 are made of resin, and the box member 150 is made of a steel plate as described above. Furthermore, as will be described later, the perforated plate 310 and many? The L plate 320 is made of an aluminum plate. All the members may be made of an aluminum member. Thereby, there is no possibility that a member will deteriorate by electric corrosion. For example, if the box member 150, perforated plates 310, 320, screws, etc. are all made of an aluminum member except for the first frame member, the second frame member, and the third frame member, the occurrence of electrolytic corrosion is ensured. Can be prevented. The first frame member 210, the second frame member 220, and the third frame member 230 are ultrasonic waves that may be bonded to each other by an adhesive that may be screwed at a portion that does not contact the perforated plates 310 and 320. Crimping by may be used.

In this case, as shown in FIG. 3, the outer peripheral partial force of the perforated plate 310 and the perforated plate 320 is supported by the first frame member 210, the second frame member 220, and the third frame member 230. As a result, the perforated plate 310 and the perforated plate 320 do not contact the box member 150. Therefore, it is possible to prevent the occurrence of an electrochemical reaction (hereinafter abbreviated as an electrolytic corrosion reaction) that occurs in the porous plates 310 and 320 and the box member 150 due to the influence of humidity and the like. In other words, the galvanic corrosion reaction corresponds to a different metal, in this embodiment, a steel plate and an aluminum plate that are different from each other, and when they are in contact with each other with moisture! appear. In this implementation, the soundproof wall 100 is usually installed outdoors, so it tends to have moisture due to wind and rain. Therefore, when the steel plate and the aluminum plate are in contact with each other, the metal part disappears due to corrosion. As a result, the perforated plates 310 and 320 may disappear, resulting in poor weather resistance. However, in the present embodiment, the occurrence of an electrolytic corrosion reaction can be prevented, the disappearance of the porous plates 310 and 320 can be prevented, and the weather resistance can be improved.

Next, FIG. 4 is a schematic perspective view in which a part of the soundproof wall 100 is enlarged.

As shown in FIG. 4, a water drain hole 180 is formed in a part of the box member 150 of the sound barrier 100. Thereby, even when the soundproof wall 100 is installed outdoors, rainwater or the like that has entered the box member 150 through the many small holes 110 of the surface 160 can be discharged. As described above, in the soundproof wall 100 according to the present embodiment, the perforated plate 310 and the perforated plate 320 are formed by the first frame member 210, the second frame member 220, and the third frame member 230 made of resin. Since it is configured so as not to contact the member 150, and further, the drainage hole 180 is formed, the electrolytic corrosion reaction can be prevented.

Next, the porous plate 310 and the porous plate 320 will be described. FIG. 5 (a) is a schematic cross-sectional view of the porous plate 310, and FIG. 5 (b) is a schematic plan view of the porous plate 310.

[0121] As shown in Fig. 5 (a), the perforated plate 310 is formed by continuously forming a mountain shape 311 and a valley shape 312 by embossing! When the embossed peak shape 311 and valley shape 312 exceed the ductility of the aluminum plate of the perforated plate 310, minute perforations 315 are formed in the aluminum plate. Note that the microporous 315 formed by embossing has a shape close to a cross-shaped hole formed by a circular hole. Hereinafter, the shape close to the cross-shaped hole will be described as a circular hole having an equivalent hole area.

Thus, by processing the aluminum plate by embossing, it is possible to form a uniform and minute porous 315.

In addition, as shown in FIG. 5 (b), the rigidity of the porous plate 310 can be increased by alternately forming the peak shape 311 and the valley shape 312 in a staggered pattern. That is, even when the porous plate 310 is thin, the rigidity can be increased by embossing, so that the assembly efficiency is improved and the soundproof wall 100 can be easily manufactured.

In the porous plate 310 shown in FIG. 5, the pore diameter of the minute porous 315 is, for example, 0.05 mm or more and 0.15 mm or less, and the aperture ratio of the porous plate 310 is 0.3% or more and 1.0% or less. .

Next, FIG. 6 (a) is a schematic sectional view of the porous plate 320, and FIG. 6 (b) is a schematic plan view of the porous plate 320.

[0126] As shown in Fig. 6 (a), the perforated plate 320 has a mountain shape 321 and a valley shape 322 continuously formed by embossing. When the embossed peak shape 321 and the valley shape 322 exceed the ductility of the aluminum plate of the porous plate 320, minute pores 325 are formed in the aluminum plate. Note that the microporous 325 formed by embossing has a shape close to a cross-shaped hole formed by a circular hole. Hereinafter, the shape close to the cross-shaped hole will be described as a circular hole having an equivalent hole area. Thus, by processing the aluminum plate by embossing, it becomes possible to form a uniform and minute porous 325.

[0128] Further, as shown in Fig. 6 (b), the rigidity of the porous plate 320 can be increased by alternately forming the mountain shape 321 and the valley shape 322 in a staggered pattern. That is, even when the thickness of the perforated plate 320 is thin, the rigidity can be increased by embossing, so that the assembly efficiency is improved and the soundproof wall 100 can be easily manufactured.

[0129] In the perforated plate 320 shown in FIG. 6, unlike the perforated plate 310 shown in FIG. 5, the pore diameter of the minute perforated 325 is, for example, 0.05 mm or more and 0.15 mm or less. The aperture ratio is 0.2% or more and 0.8% or less. That is, the aperture ratio is smaller than that of the porous plate 310 shown in FIG. 5, which has a smaller aperture ratio than the porous surface 160 shown in FIG. That is, from the larger aperture ratio to the smaller aperture ratio, the number of small holes 110 on the surface 160, the minute porosity 315, and the minute porosity 325 are in this order. This effect will be described later.

In the porous plates 310 and 320 described above, each parameter is set so as to cause a viscous action on the air passing through the porous 315 and 325. As a result, when a viscous damping action occurs in the air passing through the porous holes 315 and 325, the air vibrations are converted into thermal energy, resulting in the damping of the air vibrations, resulting in a sound absorption effect in a relatively wide frequency band. become able to.

In the present embodiment, the force for forming the perforated plates 315 and 325 by embossing is not limited to this, and the perforated plates 315 and 325 may be formed by other arbitrary processing such as punching processing.

FIG. 7 is a schematic diagram for explaining the aperture ratios of the hole 110 of the surface 160, the porous plate 310, and the porous plate 320. The vertical axis in Fig. 7 represents the normal incidence sound absorption coefficient for the sound from the sound source, and the horizontal axis represents the 1/3 octave band frequency (Hz).

[0133] In the present embodiment, the sound source is noise, and since it is a sound barrier that protects the noise, the noise used as the sound source shows a high value in a specific frequency range. Therefore, for example, in the case of railways, the main frequency band is from 400 Hz to 4 kHz, and in highways, etc., the main frequency band is from 250 Hz to 4 kHz, so noise is efficiently absorbed by absorbing sound in that band. It can be reduced well. [0134] The solid line A in Fig. 7 shows the calculated value of the normal incident sound absorption coefficient when the aperture ratio in the hole 110 of the surface 160 is 5% and the aperture ratio of the porous plate 310 is 0.43%. The broken line B shows the calculated value of the normal incident sound absorption coefficient when the aperture ratio of the hole 160 in the surface 160 is 0.43% and the aperture ratio of the porous plate 310 is 5%.

Here, each parameter of the soundproof wall 100 shown by a solid line A in FIG. 7 is that the thickness of the surface 160 is 0.8 mm, the aperture ratio in the surface 160 is 5%, and a large number of small holes 110 are used. The hole diameter of the porous plate 310 is 0.8 mm, the air layer (distance L1) is 15 mm, the hole diameter of the porous plate 315 of the porous plate 310 is 0.07 mm, and the plate thickness of the porous plate 310 is 0.1 mm. The aperture ratio at 310 is 0.43%, the air layer (distance L2) is 30 mm, the pore diameter of the perforated plate 320 is 0.12 mm, and the thickness of the perforated plate 320 is 0.1 mm. Yes, the aperture ratio in the porous plate 320 is 0.36%, and the air layer (distance L3) is 53 mm.

[0136] Since the surface 160 and the perforated plates 310 and 320 each have a sound absorption peak frequency, the aperture ratio, the hole diameter, the plate thickness, and the air layer between the perforated plates are optimally designed. Thus, three sound absorption peak frequencies can be set, and a high level and sound absorption rate can be obtained in a wide band, that is, the frequency band of the region AL.

[0137] On the other hand, each parameter of the soundproof wall indicated by dotted line B in FIG. 7 is that the thickness of the surface 160 is 0.8 mm, the aperture ratio in the surface 160 is 0.43%, and the hole diameters of the numerous small holes 110 are Is 0.8 mm, the air layer (distance L1) is 15 mm, the pore diameter of the porous plate 315 of the porous plate 310 is 0.07 mm, the plate thickness of the porous plate 310 is 0.1 mm, and the porous plate 310 The aperture ratio is 5%, the air layer (distance L2) is 30 mm, the pore diameter of the perforated plate 320 is 0.12 mm, the thickness of the perforated plate 320 is 0.1 mm, The aperture ratio at 320 is 0.36%, and the air layer (distance L3) is 53 mm.

That is, in the solid line A in FIG. 7, the sound source in the order of the aperture ratio of the large number of small holes 110 is 5%, the aperture ratio of the porous 315 is 0.43%, and the aperture ratio of the porous 325 is 0.36%. In contrast, the value of the aperture ratio decreases in a stepwise manner from the direction closer to the distance from the near side, whereas in the broken line B in FIG. 7, the aperture ratio of the large number of small holes 110 is 0.43%, and the aperture of the porous 315 The aperture ratio gradually increases or decreases in the order of 5% and the aperture ratio of Porous 325 in the order of 0.36%. Thus, by comparing the solid line A and the broken line B in FIG. 7, the vertical incident sound absorption coefficient of the broken line B in FIG. 7 is only 0 at the 1/3 octave band frequency between about 400 Hz and 800 Hz. While the effect of 6 or more was not seen, the solid line A in Fig. 7 shows an effect of normal incidence sound absorption coefficient of 0.6 or more at 1/3 octave band frequency from 500 Hz to 5 kHz. It was found that sound can be effectively absorbed even for railway noise and highway noise. If the aperture ratio increases or decreases stepwise in this way, high sound absorption performance cannot be obtained over a wide band.

[0140] From the above, it is possible to reduce the sound from the sound source in steps by setting the aperture ratio to be smaller as the distance from the sound source increases, and as a result, it is possible to reduce the broadband sound. It was found that the effect is obtained.

[0141] (Other examples)

Furthermore, the porous plate 320 in the present embodiment may be configured to satisfy the relationship of the following formula (1). Here, the porous plate 310 closer to the sound source is referred to as the first porous plate 310, and the far porous plate 320 away from the sound source is referred to as the second porous plate 320. The farthest from the sound source! /, The second porous plate 320 is the lowermost porous plate 320.

[0142] y ^ O. 0086x + 0. 0076 · · · · (1)

[0143] In the above formula (1), X is a value obtained by dividing the plate thickness of the perforated plates 310 and 320 by the hole diameter of the perforated plates 315 and 325, and y is the aperture ratio of the perforated plates 310 and 320. If the aperture ratio y of 320 satisfies equation (1), the sound absorption coefficient reference value of the sound absorption panel for roads of JH (formerly the Japan Highway Public Corporation) is satisfied.

Note that the sound absorption coefficient reference value of road acoustic panels at JH is 0.7 or higher at 400 Hz and 0.8 or higher at lkH z.

[0144] Fig. 8 is a graph showing the results of measuring the sound absorption coefficient for the sound from the sound source for each frequency by varying the aperture ratio of the porous plate 320 in the lowermost layer (second layer). It is. In Fig. 8, the vertical axis represents the sound absorption rate for sound from the sound source, and the horizontal axis represents 1/3 octave band frequency (Hz). Here, Casel is set so that the aperture ratio y of the second layer of porous plate 320 satisfies the relationship of Equation (1), while Case2 has the aperture ratio y of the second layer of porous plate 320 It is set outside the range that satisfies the relationship of equation (1). The first layer of perforated plate 310 The aperture ratio y is set outside the range that satisfies the relationship of equation (1) for both Casel and Case2.

Yes

[0145] As shown in Fig. 8, in Casel where the aperture ratio y of the second layer porous plate 320 is set within the range satisfying the relationship of the expression (1), the aperture ratio of the second layer porous plate 320 is Compared to Case 2 where y is set outside the range that satisfies the relationship of equation (1), the sound absorption rate is higher. Specifically, Casel's sound absorption coefficient at 400Hz is higher than 0.7, which is the standard value of JH's sound absorption coefficient at 400Hz, while Case2's sound absorption coefficient at 400Hz is the standard value of JH's sound absorption coefficient at 400Hz. Is lower than 0.7. In addition, Casel's sound absorption coefficient at 1 kHz is higher than the reference value of JH's sound absorption coefficient at 1 kHz, while Case2's sound absorption coefficient at 1 kHz is the reference value of JH's sound absorption coefficient at 1 kHz. Lower than 8.

[0146] From the above, in the lowermost porous plate 320, by setting the aperture ratio y so that the value X obtained by dividing the plate thickness by the hole diameter and the aperture ratio y satisfy the formula (1), the sound absorption coefficient Was found to improve.

[0147] Note that the aperture ratio y of the first porous plate 310 may be set so as to satisfy the relationship of the expression (1).

[0148] (Another example)

Next, the soundproof wall 100a will be described with reference to the drawings. The soundproof wall 100a is obtained by attaching a sound attenuating member to the perforated plates 310 and 320 of the soundproof wall 100. FIG. 8 and FIG. 9 are schematic diagrams for explaining a state in which a sound attenuating member is attached to the multi-hole plate 310 and the perforated plate 320.

As shown in FIG. 9 and FIG. 10, the sound attenuating member 318 and the sound attenuating member 328 are attached to the outer peripheral regions of the perforated plate 310 and the perforated plate 320, respectively. Thereby, the rigidity of the perforated plate 310 and the perforated plate 320 can be increased. Further, since the perforated plates 310 and 320 are formed of a composite material together with the sound attenuating members 318 and 328, the resonance peak can be reduced.

As a result, sound can be further effectively reduced in the porous plate 310 and the porous plate 320. In this example, the force with which the sound attenuating members 318 and 328 are attached to the perforated plate 310 and the perforated plate 320 is not limited to this. Sound attenuation members 318 and 328 may be attached to the entire surface, and then fine perforations 315 and 325 may be formed by embossing. Sound attenuation is applied only to one of the front and back surfaces of porous plate 310 and porous plate 320. The members 318 and 328 may be attached. Further, as the sound attenuating members 318 and 328, any of various tape members, coating materials, coating materials, or arbitrary members may be used. Further, in the present embodiment, the force of using one perforated plate 310 and one multi-perforated plate 320 is not limited to this, and a perforated plate having a damping function may be used, and a plurality of perforated plates may be used. Alternatively, a porous plate formed by stacking multiple porous plates may be used. That is, a porous plate that is the same as or different from the porous plate may be brought into contact with each other and used as a single porous plate. By applying damping to the perforated plate with these means, it is possible to reduce vibration due to resonance of the perforated plate, increase the relative speed difference between the perforated plate and air, and prevent deterioration in sound absorption performance.

[0151] (Another example)

FIG. 11 is a schematic cross-sectional view for explaining a soundproof wall 100b that further includes sound attenuating members 510, 520, and 530 in addition to the soundproof wall 100. FIG.

As shown in FIG. 11, in the soundproof wall 100b, the sound attenuating member 510 is provided in the space formed by the large number of small holes 110, the first frame member 210, and the perforated plate 310 on the surface 160 of the box member 150. And a sound attenuating member 520 is provided in a space formed by the minute perforated plate 315 of the perforated plate 310, the second frame member 220, and the perforated plate 320, and the minute perforated plate 325 of the perforated plate 320, the third frame member. A sound attenuating member 530 is provided in a space formed by 230 and the box member 150.

[0153] In the soundproof wall 100b in yet another example, the sound attenuating members 510, 520 and 530 are provided in each space. However, the sound attenuating members 510, 520, 530 are not limited thereto. It is possible to provide at least one sound-attenuating saddle member of 530, and the sound attenuating members 510, 520, and 530 are the first frame member 210, the second frame member 220, and the third member, respectively. The frame member 230 may be fixed to at least one of the forces.

[0154] In this case, the force S can be used to easily manufacture the soundproof wall 100b by inserting the unit 200 into the box member 150.

[0155] The sound source attenuating members 510, 520 and 530 are made of glass wool, rock wool, open cell urethane, non-woven fabric or any other member which may be made of PET fiber resin. May be.

[0156] (Another example)

FIG. 12 is a schematic diagram for explaining an example of the soundproof wall 100c. FIG. 12 (a) shows a schematic perspective view of the soundproof wall 100c, and FIG. 12 (b) shows a schematic cross-sectional view of the soundproof wall 100c.

[0157] As shown in Fig. 12 (a), a large number of holes 110c are formed in the surface 160c of the box member 150c of the soundproof wall 100c by a louver fin shape. In FIG. 12 (a), a large number of holes 110c are arranged in a plurality of rows. However, the present invention is not limited to this, and the holes 110c may be arranged in a staggered manner or any other method.

In addition, as shown in FIG. 12 (b), the unit 200 in the soundproof wall 100c includes a box box 150c, perforated plates 310, 320, and 330, a first frame member 210, a second frame member 220, and a third frame. A frame member 230 and a fourth frame member 240 are provided.

As in FIG. 3, the outer peripheral portion of the porous plate 310 is sandwiched between the first frame member 210 and the second frame member 220, and the second frame member 220 and the third frame member 230 are sandwiched between them. The outer periphery of the perforated plate 320 is sandwiched, and the outer periphery of the perforated plate 330 is sandwiched between the third frame member 220 and the fourth frame member 230. Further, a porous plate 335 is formed in the porous plate 330 in the same manner as the porous plates 310 and 320 in FIGS.

[0160] Also, as shown in FIG. 12 (b), the thickness of the first frame member 210 is L1, the thickness of the second frame member 220 is L2, and the thickness of the third frame member 230 is L3. The thickness of the fourth frame member 240 is L4. These thicknesses LI, L2, L3 and L4 are determined by the wavelength of the sound wave to be absorbed among the sound waves coming from the sound source, and the thickness, hole diameter and aperture ratio of the perforated plate. Therefore, in the present embodiment, the forces assumed to have different values of the thicknesses LI, L2, L3, and L4 are not limited to this, and any force and the two thicknesses may have the same value. All the thicknesses LI, L2, L3 and L4 may be the same value. In addition, the perforated plate 310 and the multi-hole plate 320 are not limited to the case where they are arranged in parallel, but are opposed to each other at an arbitrary angle, such as when they are substantially parallel or arranged in parallel. It may be.

[0161] Since the large number of holes 110c are formed in a louver fin shape, the intrusion of rainwater can be efficiently prevented, and sound from a sound source to be absorbed can be taken in. As a result, the sound of the sound source can be reduced efficiently. Also during transportation It is effective as a protective plate to prevent intrusion when the load falls or when stones are scattered.

FIG. 13 is a schematic diagram for explaining the effect of the soundproof wall 100c in FIG. The vertical axis in Fig. 13 represents the normal incident sound absorption coefficient for the sound from the sound source, and the horizontal axis represents the 1/3 octave band frequency (Hz).

[0163] Here, each parameter of the soundproof wall 100c shown in Fig. 12 is that the thickness of the surface 160c is lmm, the aperture ratio power at the surface 160c is 2.8%, and the air layer (distance L1) is 10mm. Yes, the porous plate 310 has a pore diameter of 0.1 mm, the porous plate 310 has a thickness of 0.1 mm, the aperture ratio in the porous plate 310 is 0.89%, and the air layer (distance L2) is 5 mm. The porous plate 320 has a pore diameter of 0.07 mm, the porous plate 320 has a thickness of 0.1 mm, the aperture ratio of the porous plate 310 is 0.55%, and the air layer (distance L3) is 30 mm, the pore size of the perforated plate 330 is 0.07 mm, the thickness of the perforated plate 330 is 0.1 mm, and the aperture ratio in the perforated plate 330 is 0.24%. , Air layer (distance L4) force is 5mm. (Note that the thickness of the surface 160c including the machining height of the louver and fin is 12mm.)

[0164] Since the surface 160c and the perforated plates 310, 320, and 330 each have a sound absorption peak frequency in this manner, the aperture ratio, the hole diameter, the plate thickness, and the air layer between the perforated plates are optimally designed. As shown in Fig. 4, four sound absorption peak frequencies can be set, and by designing them so that they are continuously arranged, a high sound absorption coefficient can be obtained in a wide frequency band.

[0165] In FIG. 12, the force that forms a large number of holes 110c in the surface 160c due to the louver fin shape is not limited to this, and the louver fin shape is applied to the porous plate 310, the porous plate 320, and the porous plate 330. A large number of holes may be formed. Also, the present invention is not limited to the louver fin shape, and other arbitrary hole shapes such as a slit shape, a circular shape, an elliptical shape, and an irregular shape may be formed.

From the above, a plurality of perforated plates 310, 320 are sandwiched by a plurality of frame members 210, 220, 230 with respect to the box member 150 constituting the soundproof walls 100, 100a, 100b, 100c. By forming 200, the unit 200 can be easily put into the internal space of the box member 150 in the manufacturing process. As a result, the soundproof wall 100 can be easily manufactured, and positioning for fixing the plurality of perforated plates 310 and 320 to the internal space of the box member 150 is possible. You can reduce your work. In addition, by unitizing, each internal space inside the unit 200 is kept airtight except for the perforated plates 310 and 320 except for the perforated plates 315 and 325, so that the sound source power and other sounds can be effectively reduced. Can do. Further, in this case, the sound from the sound source is absorbed by a large number of / J, 孑 L110 in the box member 150, and further by the plurality of perforated plates 310, 320 sandwiched between the plurality of frame screens 210, 220, 230. Sound is absorbed.

[0167] Further, the plurality of multiple multi-plates 310, 320 are sandwiched by three solid frame members 210, 220, 230 to form a unit, and the unit 200 is easily accommodated in the box member 150. be able to. In addition, since the three frame members are made of non-conductive resin, and the plurality of porous plates 310 and 320 do not contact the inner peripheral surface of the box member 150, damage to the porous plates 310 and 320 during manufacturing is prevented. The stopping force S can be prevented, and the electrolytic corrosion of the perforated plates 310 and 320 can be prevented. In addition, the durability and weather resistance of the soundproof wall 100 can be improved. As a result, sound absorption performance can be maintained for a long time.

[0168] Also, a plurality of perforated plates 310, 320 force Sanolemium member force, and further, the perforated plates 310, 320 are formed by embossing, so that the ridge shape 311 in embossing and The rigidity of the porous plates 310 and 320 can be increased by the valley shape 312, the mountain shape 321 and the valley shape 322, so that even if the thin porous plates 310 and 320 are used, the rigidity of the porous plates 310 and 320 themselves Can be increased. As a result, work efficiency in manufacturing the soundproof wall 100 can be increased. Further, since an aluminum member is used, it can be manufactured at low cost, and can be easily processed and a large number of minute holes 315 and 325 can be formed, thereby improving recyclability. Therefore, all the members of the sound barrier 100 are made of aluminum.

[0169] Further, since the surface 160 and the perforated plates 310, 320 are arranged so that the aperture ratio decreases as the distance from the sound source increases, it is possible to effectively reduce sound in a wide frequency band. In addition, since the water drainage hole 180 is formed, the water drainage hole 180 force is provided even when the water is infiltrated by rainwater or the like in the internal space of the box member 150 when installed outdoors. It is possible to drain rainwater and prevent electric corrosion.

[0170] Furthermore, the sound attenuating members 318, 328, 510, 520, 5 in at least one of the plurality of spaces separated by the plurality of frame members 210, 220, 230 and the plurality of perforated plates 310, 320 Since 30 is arranged and unitized, the soundproof wall 100 can be easily manufactured, and the sound of the sound source can be more effectively reduced as compared with the case of only the plurality of perforated plates 310 and 320. That's the power S.

[0171] Further, since the sound attenuating members 510, 520, 530 are made of a porous material, non-woven fabric, glass wool, or PET fiber material, the glass wool or PET fiber material is simply disposed inside the box member 150. Compared with the case, it is possible to eliminate the bias of the sound attenuating members 510, 520, and 530 due to their own weight. As a result, the sound S effectively reduces the sound from the sound source in the noise barrier 100.

Further, the unit 200 is formed by sandwiching the plurality of perforated plates 310, 320, 330 with the plurality of frame members 210, 220, 20, 30, 240 with respect to the box member 150c constituting the soundproof wall 100c. Thus, it is possible to easily put the unit 200 into the internal space of the box member 150c in the manufacturing process. As a result, the soundproof wall 100c can be easily manufactured, and the force S for reducing the positioning work for fixing the plurality of multi-hole plates 310, 320, 330 to the internal space of the box member 150c can be reduced. In addition, as a result of unitization, the internal space inside the unit 200 is kept airtight except for the multiple plates 315, 325, and 335 of the inner space plates 310, 320, and 330. Can be effectively reduced. Further, in this case, while rainwater is shielded, sound from the sound source is transmitted through the small holes 110 having a louver fin shape in the box member 150c while being absorbed and sandwiched by the plurality of frame members 210, 220, 230, 240. Sound is absorbed by the plurality of multi-hole plates 310, 320, 330.

[0173] Further, the four frame members are made of a resin that is a non-conductor, and the plurality of perforated plates 310, 320, 330 are not in contact with the inner peripheral surface of the box member 150c. 320 and 330 can be prevented from being damaged, and electrolytic corrosion of the perforated plates 310, 320 and 330 can be prevented. Further, the durability and weather resistance of the soundproof wall 100c can be improved. As a result, sound absorption performance can be maintained for a long time.

[0174] In addition, a plurality of perforated plates 310, 320, 330 force, Sanoremium member force, and moreover, because it is formed by multi-layered 315, 325, 335 caustic embossing on perforated plates 31 0, 320, 330, embossing Oka IJ properties of the porous plates 310, 320, 330 can be enhanced by the shape of the peaks and valleys at the time, so even if thin porous plates 310, 320, 330 are used, The rigidity of the perforated plates 310, 320, 330 itself can be increased. As a result, work efficiency in manufacturing the soundproof wall 100c can be increased. Furthermore, since an aluminum member is used, it can be manufactured at a low cost, and it can be easily processed and can form a large number of minute holes 315, 325, 335, thereby improving recyclability. Therefore, all the members of the soundproof wall 100c are made of aluminum.

[0175] Further, since the surface 160c and the perforated plates 310, 3 20, and 330 are arranged so that the aperture ratio decreases as the distance from the sound source increases, it is possible to effectively reduce sound in a wider frequency band. .

[0176] Furthermore, the sound attenuating members 318, 328 are provided in at least one of the plurality of spaces separated by the plurality of frame members 210, 220, 230, 240 and the plurality of multi-colored plates 310, 320, 330. , 5 10, 520, 530, and other sound attenuating members are also arranged in the air layer (distance L4) in the same way, and unitized, compared to the case of multiple perforated plates 310, 320, 330 only. The sound of the sound source may be further effectively reduced.

Next, a second embodiment according to the present invention will be described.

(Second embodiment)

FIG. 14 is a schematic cross-sectional view showing an example of a cross section of a sound absorbing structure according to the second embodiment.

The sound absorbing structure 100c of FIG. 14 includes a first plate member 160, perforated plates 310 and 320, and a second plate member 150. The first plate member 160 is disposed so as to face the sound source, and the perforated plates 310 and 320 and the second plate member 150 are sequentially disposed so as to be parallel to the first plate member 160. Yes. In the present embodiment, the perforated plates 310 and 320 and the second plate member 150 force are illustrated as being provided in parallel to the first plate member 160. And can be arranged at an angle! / ,.

[0179] The sound absorbing structure 100c shown in FIG. 14 includes air between the first plate member 160 and the porous plate 310, between the porous plate 310 and the porous plate 320, and between the porous plate 320 and the second plate member 150, respectively. A layer is formed.

[0180] The first plate member 160 is provided with an opening 110. The hole diameter of the opening 110 is, for example, 0.3 mm or more and 3 mm or less, and the opening ratio of the first plate member 160 is 10% or less. is there. Also, In the present embodiment, the first plate member 160 and the second plate member 150 are made of steel plates (for example, highly weather-resistant matte steel plates). As a result, it is possible to reduce the manufacturing cost of the box member 150 with the force S.

[0181] Further, the porous plate 310 is provided with an opening 315, and the hole diameter of the opening 315 is, for example, 0.05 mm or more and 0.15 mm or less, and the opening ratio of the porous plate 310 is 0.3. % To 1.0%.

[0182] Further, the porous plate 320 is provided with an opening 325, and the hole diameter of the opening 325 is, for example, 0.05 mm or more and 0.15 mm or less, and the opening ratio of the porous plate 320 is 0.2. % Or more and 0.8% or less.

[0183] Each of the above parameters is set so as to cause a viscous action on the air passing through the openings 110, 315, and 325. As a result, when a viscous damping action occurs in the air passing through the openings 110, 315, and 325, the air vibrations are converted into thermal energy, resulting in the damping of the air vibrations. The sound absorption effect can be demonstrated with.

[0184] Further, among the first plate member 160, the porous plates 310 and 320, and the second plate member 150, the aperture ratio of the first plate member 160 increases in the order of the porous plates 310 and 320 having the largest aperture ratio. As a result, the first plate member 160 and the perforated plates 310 and 320 have different frequency bands in which the sound absorbing effect is exerted. Therefore, in the sound absorbing structure 100d using them, the frequency components other than the resonance frequency over a wide frequency band. The sound absorption effect can be exhibited even in noise having a noise.

[0185] In the first plate member 160 and the perforated plates 310 and 320, by suppressing a sudden drop in the sound absorption coefficient, a high sound absorption effect can be exhibited over a wide frequency band. In addition, by decreasing the aperture ratio stepwise in the order of the first plate member 160 and the perforated plates 310 and 320, the sound with a wavelength shorter than the frequency absorbed in the opening 110 of the first plate member 160 is obtained. Sound can be absorbed by the perforated plates 310 and 320, and sound with a shorter wavelength than the frequency of sound absorption at the opening 315 of the perforated plate 310 can be absorbed by the perforated plate 320.

Further, as shown in FIG. 14, the interval between the first plate member 160 and the porous plate 310 is a distance L1, and the interval between the porous plate 310 and the porous plate 320 is a distance L2, Second plate member 150 and Is the distance L3. In this way, the distances LI, L2, and L3 are different forces, and are not limited to this, and they may all be the same distance.

[0187] In the present embodiment, the first plate member 160, the perforated plates 310, 320, and the second plate member 150 are not limited to this, and are not limited thereto. For example, It is good also as what consists of a plane of a circular shape, an ellipse shape, and a triangular shape. Furthermore, the force that the first plate member 160, the perforated plates 310 and 320, and the second plate member 150 of the sound absorbing structure 100c have a predetermined size area is not limited to this, and the manufacturing problem is solved. For this reason, the sound absorbing structure 100c may be formed smaller than a predetermined size, and a plurality of sound absorbing structures 100c may be provided to form a sound absorbing structure having an area of a predetermined size.

[0188] Furthermore, the first plate member 160, the perforated plates 310 and 320, and the second plate member 150 are not limited to this force. One member is a flat plate and the other member is a thin film. It may be made from. Moreover, all the members may consist of thin films. For example, all of the first plate member 160, the perforated plates 310 and 320, and the second plate member 150 may be made of an arbitrary plate material such as a steel plate (for example, a highly weather-resistant steel plate), an anode plate material, a resin, or the like.

Next, an example of the porous plate 310 and the porous plate 320 will be described. Figure 15 (a) shows a perforated plate

FIG. 15B is a schematic cross-sectional view of 310, and FIG.

[0190] As shown in Fig. 15 (a), the perforated plate 310 is embossed to form a mountain shape 311 and a valley shape.

312 is formed continuously. When the embossed peak shape 311 and valley shape 312 exceed the ductility of the aluminum plate of the porous plate 310, minute openings 315 are formed in the aluminum plate. Note that the minute opening 315 formed by embossing has a shape close to a cross-shaped hole formed by a circular hole. Hereinafter, the shape close to the cross-shaped hole will be described as a circular hole having an equivalent hole area.

Thus, by processing the aluminum plate by embossing, it is possible to form a uniform and minute opening 315.

Further, as shown in FIG. 15 (b), the rigidity of the porous plate 310 can be increased by alternately forming the mountain shape 311 and the valley shape 312 in a staggered pattern. That is, even when the thickness of the perforated plate 310 is thin, the rigidity can be increased by embossing, so that the assembly efficiency is improved. Next, FIG. 16 (a) is a schematic cross-sectional view of the porous plate 320, and FIG. 16 (b) is a schematic plan view of the porous plate 320.

[0194] As shown in Fig. 16 (a), the perforated plate 320 is formed with a mountain shape 321 and a valley shape 322 continuously by embossing. When the embossed peak shape 321 and valley shape 322 exceed the ductility of the aluminum plate of the perforated plate 320, minute openings 325 are formed in the aluminum plate. Note that the minute opening 325 formed by embossing has a shape close to a cruciform hole formed by a circular hole. Hereinafter, the shape close to the cross-shaped hole will be described as a circular hole having an equivalent hole area.

[0195] Thus, by processing the aluminum plate by embossing, it is possible to form a uniform and minute opening 325.

[0196] Further, as shown in Fig. 16 (b), the rigidity of the porous plate 320 can be increased by alternately forming the mountain shape 321 and the valley shape 322 in a zigzag shape. That is, even when the thickness of the porous plate 320 is thin, the rigidity can be increased by embossing, so that the assembly efficiency is improved and the soundproof wall 100 can be easily manufactured.

In the porous plate 310 shown in FIG. 15, for example, the hole diameter of the opening 315 is 0.05 mm or more and 0.15 mm or less, and the opening ratio of the porous plate 310 is 0.3% or more and 1.0% or less. is there. In the porous plate 320 shown in FIG. 16, for example, the hole diameter of the opening 325 is 0.05 mm or more and 0.15 mm or less, and the opening ratio of the porous plate 320 is 0.2% or more and 0.8% or less. .

[0198] In FIGS. 15 and 16, the force with which the perforated plates 310 and 320 are made of an aluminum member is not limited to this, and may be made of any other metal processing member or resin. Good. Further, the force that the holes 315 and 325 formed in the perforated plates 310 and 320 are formed by embossing is not limited to this, and it is possible to form by punching or any other Karoe. .

Next, FIG. 17 is a schematic cross-sectional view for explaining a sound absorbing structure 100e further including sound attenuating members 510, 520, 530 in addition to the sound absorbing structure 100d.

As shown in FIG. 17, in the sound absorbing structure 100d, a sound attenuating member 510 is provided in the air layer formed by the first plate member 160 and the porous plate 310, and the porous plate 310 and the porous plate 320 A sound attenuating member 520 is provided in the formed air layer, and the perforated plate 320 and the second plate A sound attenuating member 530 is provided in the air layer formed by the plate member 150.

[0201] In the sound absorbing structure 100d described above, the force of providing the sound attenuating members 510, 520 and 530 in each air layer is not limited to this, and the sound attenuating ability 510, 520, 530 is used. In other words, at least one sound attenuating member may be provided. Sound attenuating members 510, 520 and 530 may be fixed to the first plate member 160, the perforated plates 310, 320 and the second plate member 150, respectively. Good.

[0202] Thereby, in addition to the sound absorbing effect of the sound absorbing structure 100d composed of only the first plate member 160, the perforated plates 310, 320, and the second plate member 150, the sound absorbing effect in the sound attenuating members 510, 520, 530 is further increased. Because it can be added, it is more preferable! /, Can achieve a sound absorption effect

Yes

[0203] The sound source attenuating members 510, 520, and 530 may be made of PET fiber resin, glass wool, rock wool, open cell urethane, nonwoven fabric, or any other member.

[0204] Next, the sound absorbing structure 100f will be described with reference to FIG. FIG. 18 is a schematic cross-sectional view for explaining a state in which a sound attenuating member is attached to the perforated plate 310 and the perforated plate 320. The sound absorbing structure 100f is obtained by attaching a sound attenuating member to the perforated plates 310 and 320 of the sound absorbing structure 100d.

As shown in FIG. 18, the sound attenuating member 318 and the sound attenuating member 328 are attached to the entire surface of the perforated plate 310 and the perforated plate 320, respectively. As a result, the number of Oka IJs in the perforated plate 310 and the perforated plate 320 can be increased. Furthermore, many? Since the L plates 310 and 320 are formed of a composite material together with the sound attenuation members 318 and 328, the resonance peak can be reduced.

As a result, sound can be further effectively reduced in the perforated plate 310 and the perforated plate 320. In this example, the force of attaching the sound attenuating members 318 and 328 to the entire surface of the porous plate 310 and the porous plate 320 is not limited to this, and the sound is not limited to the outer periphery of the porous plate 310 and the porous plate 320. The sound attenuating members 318 and 328 may be attached to only one of the front and back surfaces of the perforated plate 310 and the perforated plate 320 on which the attenuating members 318 and 328 may be attached. Further, as the sound attenuating members 318 and 328, any of various tape members, coating materials, coating materials, or arbitrary members may be used. Furthermore, in the present embodiment, one sheet The perforated plate 310 and the force of using a single perforated plate 320 are not limited to this, and a perforated plate in which a plurality of perforated plates are laminated may be used. It may be used. That is, a porous plate that is the same as or different from the porous plate may be brought into contact with each other and used as a single porous plate. By applying damping to the perforated plate by these means, vibration due to resonance of the perforated plate can be reduced, and the relative speed difference between the perforated plate and air can be increased to prevent a decrease in sound absorption performance. .

[0207] As described above, in the sound absorbing structures 100d, 100e, 100f, the first plate member 160 and the perforated plates 310, 320 are arranged so that the aperture ratio of the opening portion decreases as the distance from the sound source increases. Therefore, the power S can be used to effectively and gradually reduce the sound in a wide frequency band from the sound source.

[0208] Also, since the sound attenuating members 510, 520, 530 are disposed at least at one place between each of the first plate member 160, the perforated plates 310, 320, and the second plate member 150, the first plate Compared with the case of only the member 160, the perforated plates 310 and 320, and the second plate member 150, the power S can be reduced more effectively. In addition, since the sound attenuating members 510, 520, and 530 are made of a porous material, non-woven fabric, glass wool, or PET (Poly Ethylene Terephthalate) fiber material, the sound from the sound source can be more effectively reduced.

[0209] Further, the openings 110, 315, and 325 may be any of small holes, circular holes, slit-shaped holes, irregular-shaped holes, and rubber fin-shaped holes, thereby reducing manufacturing costs. It becomes possible.

[0210] Also, since each of the first plate member 160, the perforated plates 310 and 320, and the second plate member 150 is made of a force aluminum member, it can be manufactured at a low cost, and it is easy to process and has minute holes. Many can power to form. In addition, recyclability is improved by using aluminum members.

[0211] Further, since the openings 315 and 325 are formed by embossing, a force S for uniformly forming the openings can be obtained. Further, since the rigidity of the porous plate can be increased by the crest shape and the valley shape at the time of embossing, the rigidity of the porous plate 310, 320 itself can be increased even when the thin porous plate 310, 320 is used. Can absorb sound efficiently. [0212] Further, when the perforated plates 310 and 320 themselves have a force damping structure, the vibration due to resonance of the perforated plates 310 and 320 is reduced, and the relative speed difference between the perforated plates 310 and 320 and air is increased. A decrease in sound absorption performance can be prevented. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0213] The perforated plates 310 and 320 may be made of plate member force having vibration damping properties that may be arranged in contact with each other. In this case, since the perforated plate itself has vibration damping properties, the vibration due to resonance of the perforated plate is reduced, and the relative speed difference between the perforated plate and air is increased to prevent deterioration of the sound absorption performance. it can. As a result, the sound absorbing structure can effectively reduce the sound from the sound source.

[0214] In the first embodiment, the wall structure 100, 100a, 100b, 100c corresponds to the sound absorbing structure, the surface 160 corresponds to the porous surface, the box member 150 corresponds to the box member, and the porous structure The plates 310, 320, 330 correspond to a plurality of perforated plates, the first frame member 210, the second frame member 220, the third frame member 230, the fourth frame member correspond to a plurality of support frames, and the unit 200 Corresponding to unitization, mountain shape 31 1 and valley shape 312, mountain shape 321 and valley shape 322 correspond to the shape by embossing, sound attenuation member 318, sound attenuation member 328, sound attenuation member 510, 520, 530 It corresponds to the sound attenuating member, and the water draining hole 180 corresponds to the water draining hole.

[0215] In the second embodiment, the sound absorbing structures 100d, 100e, and 100f correspond to the sound absorbing structure, the first plate member 160 corresponds to the first plate member, and the second plate member 150. Applies to the second plate material, applies to multiple plates 310, 320 multiple plates, corresponds to the open P 咅 315, 325 openings, mountain shape 311 and valley shape 312, mountain The shape 321 and the valley shape 322 correspond to the shape by embossing, and the sound attenuating member 318, the sound attenuating member 328, and the sound attenuating members 510, 520, 530 correspond to the sound attenuating members.

[0216] The present invention is not limited to the force S described in the preferred first and second embodiments, and the present invention. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention. Further, in the present embodiment, the forces describing the operations and effects of the configuration of the present invention. These operations and effects are examples.

The present invention is not limited to this. Furthermore, in the present embodiment, the force exemplified by the soundproof wall as the sound absorbing structure is not limited to this, but can be applied to any other sound absorbing structure. The power S

Industrial applicability

The present invention is applicable to a sound absorbing structure that can reduce sound from a sound source.

Claims

The scope of the claims

[1] A sound absorbing structure capable of absorbing sound from a sound source,

A box member having a porous surface with a large number of openings on at least one surface;

A perforated plate having a large number of openings and separating the internal space of the box member into a plurality of spaces;

A plurality of support frames sandwiching the perforated plate and having an outer shape along the inner space of the box member,

The sound absorbing structure, wherein the plurality of support frames and the porous plate are unitized by sandwiching the porous plate by the plurality of support frames.

[2] The box member is formed of a rectangular parallelepiped, the porous surface is disposed to face the sound source, and the plurality of support frames are formed so that the porous plate is disposed in parallel to the porous surface. The sound absorbing structure according to claim 1, wherein

[3] The perforated plate is composed of a plurality of perforated plates, and the plurality of perforated plates are individually arranged in a gap formed by laminating the plurality of support frames. Unit members are formed by unitizing the frame,

The plurality of support frames are formed so that the plurality of perforated plates do not contact the inner peripheral surface of the box member when the unit member is housed in the box member. The sound absorbing structure according to 1.

4. The sound absorbing structure according to claim 1, wherein the plurality of support frames are made of a non-conductor.

[5] The sound absorbing structure according to [1], wherein the plurality of support frames are made of resin.

6. The sound-absorbing structure according to claim 1, wherein the plurality of support frames have the same thickness in the stacking direction.

7. The sound absorbing structure according to claim 1, wherein the plurality of support frames have a width in a direction perpendicular to the stacking direction that is equal to or less than a half of a wavelength from a sound source.

[8] The aperture ratio of the apertures in the porous surface and the porous plate is different between the porous surface and the porous plate, and the aperture ratio of the porous surface and the porous plate decreases as the distance from the sound source increases. 2. The sound absorbing structure according to claim 1, wherein the sound absorbing structure is formed as described above.

[9] At least one of the porous surface and the porous plate has a value obtained by dividing the plate thickness by the hole diameter of the opening, and X represents the opening ratio of the opening, and y O. 0086x 2. The sound absorbing structure according to claim 1, wherein the sound absorbing structure is formed so as to satisfy a relationship of +0.0000.

[10] The perforated plate includes a plurality of perforated plates, and at least one of the perforated surface and the plurality of perforated plates disposed at a position farthest from the sound source is y O. 0086χ + 0.007. 10. The sound absorbing structure according to claim 9, wherein the sound absorbing structure is formed so as to satisfy the relationship of 6.

[11] It further includes a sound attenuating member,

The sound attenuating member is disposed in at least one space among a plurality of spaces separated by the plurality of support frames and the perforated plate, and the sound attenuating member, the plurality of support bodies, and the perforated plate are unit. 2. The sound absorbing structure according to claim 1, wherein the sound absorbing structure is formed.

12. The sound absorbing structure according to claim 11, wherein the sound attenuating member has a porous material force.

13. The sound absorbing structure according to claim 11, wherein the sound attenuating member is made of a nonwoven fabric.

Yes

14. The sound absorbing structure according to claim 11, wherein the sound attenuating member is made of glass wool or PET fiber material.

15. The sound absorbing structure according to claim 1, wherein the opening is formed of a small hole.

16. The sound absorbing structure according to claim 1, wherein the opening is a circular hole.

17. The sound absorbing structure according to claim 1, wherein the opening is a slit-shaped hole.

18. The sound absorbing structure according to claim 1, wherein the opening is made of a hole having an irregular shape.

[19] The sound absorbing structure according to [1], wherein the porous plate is made of an aluminum member.

[20] The sound absorbing device according to [1], wherein the box member is made of an aluminum member. Structure.

21. The sound absorbing structure according to claim 1, wherein the opening is formed by embossing.

[22] The sound absorbing structure according to [1], wherein the opening is formed by punching.

23. The sound absorbing structure according to claim 1, wherein the perforated plate has a damping structure.

24. The sound absorbing structure according to claim 23, wherein the damping structure is obtained by coating the perforated plate.

[25] The sound-absorbing structure according to claim 1, wherein the perforated plate includes at least two perforated plates arranged in contact with each other.

26. The sound absorbing structure according to claim 1, wherein the porous plate is made of a plate material having vibration damping properties.

27. The sound absorbing structure according to claim 1, wherein the box member has a water drain hole penetrating the internal space and the outside.

[28] A sound absorbing structure capable of absorbing sound from a sound source,

A first plate member having a number of openings;

A second plate member provided facing the first plate member;

Including one or more perforated plates provided with a plurality of openings, and disposed between the first plate member and the second plate member,

The first plate member and the perforated plate have different aperture ratios in the first plate member and the perforated plate, are arranged in the order of the first plate member, the perforated plate, and the second plate member from the sound source, and from the sound source. A sound-absorbing structure formed such that the aperture ratio of the first plate member and the perforated plate decreases with increasing distance.

[29] At least one of the first plate member and the porous plate has a value obtained by dividing the plate thickness by the hole diameter of the opening, X, and the opening ratio of the opening is y, y 30. The sound absorbing structure according to claim 28, wherein the sound absorbing structure is formed so as to satisfy a relationship of O. 00 86χ + 0.00.

[30] The perforated plate comprises a plurality of perforated plates, and among the plurality of perforated plates, at least the 30. The sound absorbing structure according to claim 29, wherein the perforated plate arranged at a position farthest from the sound source is formed so as to satisfy a relationship of y O. 0086X + 0.00.

[31] further includes a sound attenuating member;

The sound attenuating member is disposed at least at one position between the first plate member and the perforated plate, between the perforated plate, and between the perforated plate and the second plate member. The sound absorbing structure according to 28.

32. The sound absorbing structure according to claim 31, wherein the sound attenuating member also has a porous material force.

33. The sound absorbing structure according to claim 31, wherein the sound attenuating member is made of a nonwoven fabric.

34. The sound absorbing structure according to claim 31, wherein the sound attenuating member is made of glass wool or PET fiber material.

35. The sound absorbing structure according to claim 28, wherein the opening is made of a small hole.

36. The sound absorbing structure according to claim 28, wherein the opening comprises a circular hole.

[37] The sound absorbing structure according to [28], wherein the opening comprises a slit-shaped hole.

38. The sound absorbing structure according to claim 28, wherein the opening is formed of an irregularly shaped hole.

39. The sound absorbing structure according to claim 28, wherein the perforated plate is made of an aluminum member.

40. The sound absorbing structure according to claim 28, wherein the first plate member and the second plate member are made of an aluminum member.

41. The sound absorbing structure according to claim 28, wherein the opening is formed by embossing.

42. The sound absorbing structure according to claim 28, wherein the opening is formed by punching.

[43] The sound absorbing structure according to claim 28, wherein the perforated plate has a damping structure.

44. The sound absorbing structure according to claim 43, wherein the damping structure is obtained by coating the perforated plate.

[45] The sound absorbing structure according to claim 28, wherein the perforated plate is composed of at least two perforated plates arranged in contact with each other.

46. The sound absorbing structure according to claim 28, wherein the porous plate is made of a plate material having vibration damping properties.

[47] a housing having a surface having a first hole;

A unit member having a first frame, a second frame, an intermediate member sandwiched between the first frame and the second frame and having a second hole, and housed in the housing.

The surface of the housing and the intermediate member oppose each other;

Sound absorbing structure.