JP2011242558A - Acoustic structure and standing wave reduction panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technical means which reduces a standing wave of each mode ranging from a low frequency to a high frequency without increasing burden of transportation or installation, or manufacturing cost.SOLUTION: A cavity 26-N is provided inside lateral faces 21, 22, 23, and 24 of an acoustic structure 6. When a plurality of the acoustic structures 6 are arranged side by side between a wall 1 and a wall 2 of a room 90, a standing wave reduction panel 10 having a cavity 26'-k with a length D1 which is about the same length as a distance D1 between the wall 1 and wall 2 is formed. When a standing wave SWenters into the cavity 26'-k, a standing wave SW' with about the same frequency as a standing wave Wand a phase rotated by 180 degrees to the standing wave Wis emitted from the cavity 26'-k and gaps G1 and G2. Thus, the standing wave SWis reduced.

Description

  The present invention relates to a technique for preventing acoustic disturbance in an acoustic space.

  In an acoustic space surrounded by walls, standing waves are generated by repeatedly reflecting sound between parallel facing walls, and this standing waves may cause acoustic disturbances such as booming and flutter echoes. For example, Patent Document 1 discloses a technique that discloses a technique for preventing the occurrence of this type of acoustic disturbance.

  The acoustic structure disclosed in Patent Document 1 is used by being installed on the inner wall or ceiling of a room. This acoustic structure has a plurality of rectangular pipes arranged in parallel so as to form a plane as a whole. When sound generated in the room enters the cavity in the pipe through the opening of the pipe of this acoustic structure, a standing wave corresponding to the resonance frequency of each cavity is generated in each cavity. Is emitted from the opening of the pipe toward the acoustic space. As a result, a scattering effect and a sound absorbing effect are generated in the vicinity of the opening, and standing waves in the room are reduced.

JP 2002-30744 A JP 2010-84509 A

  By the way, the acoustic structure disclosed in Patent Document 1 may be installed in a room where the distance between the walls is significantly longer than the pipe of the acoustic structure. In this case, a standing wave having a long wavelength such as a primary mode or a secondary mode is generated in the room where the acoustic structure is installed, and even if this standing wave enters the cavity, a resonance phenomenon occurs in the cavity. No standing wave having a long wavelength such as a primary mode or a secondary mode could not be reduced. On the other hand, if an acoustic structure having a cavity having a length substantially the same as the distance between walls in the room is installed in the room, standing waves having such a long wavelength can be reduced. However, there is a problem that such an acoustic structure having an excessively long cavity is not easily carried into the installation site or installed. In addition, if many types of acoustic structures are manufactured in accordance with the assumed sizes and shapes of various rooms, there is a problem that the manufacturing cost increases.

  The present invention has been devised under such a background, and does not increase the burden and manufacturing cost of transportation and installation to the acoustic space of the installation destination, and low to high frequencies generated in the acoustic space. An object of the present invention is to provide a technical means capable of reducing the standing wave in each mode.

  The present invention is an acoustic structure having a cavity extending in one direction and having one end and the other end opened in the extending direction, and the acoustic structure is connected to another acoustic structure. The acoustic structure is configured such that the cavity of the acoustic structure and the cavity of another acoustic structure are connected to form one cavity.

  According to the present invention, by connecting an appropriate number of acoustic structures, a standing wave reduction panel having a continuous cavity having a length corresponding to the distance between the walls of the acoustic space as the installation destination is configured. Can do. Therefore, it is possible to save the trouble of making an individual design corresponding to the dimensions of the room. Furthermore, technical means for reducing standing waves having a long wavelength can be installed in the acoustic space without increasing the burden of carrying-in and installation and the manufacturing cost.

It is the figure which looked at the state which installed the standing wave reduction panel which is 1st Embodiment of this invention in the room from the downward direction. It is the figure which looked at the state which installed the identification standing wave reduction panel in the room from the side. It is a perspective view of the acoustic structure which makes an identification standing wave reduction panel. It is a figure which shows the principle of reduction of a standing wave by a standing wave reduction panel. It is a perspective view which shows the acoustic structure which is 2nd Embodiment of this invention. It is a figure which shows the acoustic structure which is 3rd Embodiment of this invention, and the aspect of the installation. It is a figure which shows the acoustic structure which is 4th Embodiment of this invention, and the aspect of the installation. It is a figure which shows the acoustic structure which is 5th Embodiment of this invention, and the aspect of the installation. It is a perspective view which shows the acoustic structure in which the hanging bolt was erected. It is a perspective view which shows an acoustic structure and a suspension member. It is a figure which shows the acoustic structure which is other embodiment of this invention. It is a figure which shows the acoustic structure which is other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a view of a state in which the standing wave reducing panel 10 according to the first embodiment of the present invention is provided on the interior ceiling 5 side of the room 90 as viewed from the floor surface side below the standing wave reducing panel 10. . FIG. 2 is a view of this state as viewed from the side of the room 90. FIG. 3 is a perspective view showing one of the plurality of acoustic structures 6 constituting the standing wave reduction panel 10. In the example of FIGS. 1 and 2, a room 90 that is an acoustic space where the standing wave reduction panel 10 is installed includes an interior ceiling 5 that separates the space below the ceiling slab 70 and the room 90, and the interior ceiling 5. The floor 71 is opposed to the interior ceiling 5 and the walls 1, 2, 3, 4 orthogonal to the floor 71. In this room 90, the pair of opposing walls 1 and 2 are separated by a distance D1, and the other pair of walls 3 and 4 are separated by a distance D2.

  As shown in FIG. 3, the acoustic structure 6 includes parallel rectangular side surfaces 21 and 22 facing each other and parallel square side surfaces 23 and 24 facing each other on both sides of the side surfaces 21 and 22. It has an enclosed rectangular parallelepiped. In the acoustic structure 6, the inner sides surrounded by the side surfaces 21, 22, 23, and 24 are separated by four partition surfaces 25 -M (M = 1 to 4) parallel to the side surfaces 21, 22. There is a cavity 26-N (N = 1-5). One end and the other end in the extending direction of the cavity 26 -N (N = 1 to 5) in the acoustic structure 6 are openings.

  As shown in FIGS. 1 and 2, in this embodiment, i (in the example of FIGS. 1 and 2, i = 5) acoustic structures 6 are connected to cavities 26 -N of adjacent acoustic structures 6. One acoustic structure row 11 is connected in the extending direction of the cavity 26-N so as to become one cavity 26'-N. Then, the standing wave reduction panel 10 is obtained by combining the acoustic structure rows 11 of j rows (j = 4 in the examples of FIGS. 1 and 2) along the direction intersecting the extending direction of the cavity 26-N. And The standing wave reducing panel 10 is arranged along the interior ceiling 5 so that gaps G1 and G2 are formed between the walls 1 and 2, respectively. The length in the extending direction of the cavities 26 ′ -N (the length in the direction D <b> 1 in FIG. 1) in the j rows of acoustic structure rows 11 constituting the standing wave reducing panel 10 is j rows of acoustic structure rows 11. It is the same for all of. The total number i × j of the acoustic structures 6 installed as the standing wave reduction panel 10 in one room 90 is the interior ceiling when i × j acoustic structures 6 are arranged along the interior ceiling 5 of the room 90. The number should be sufficient to occupy almost the entire surface of 5.

The above is the details of the configuration of the standing wave reduction panel 10 and the acoustic structure 6 constituting the standing wave reduction panel 10. According to this standing wave reduction panel 10, n (n = 1, 2,...) Standing mode SW _n (n = 1, 2,...) Generated by repeated reflection of sound waves between the walls 1 and 2 of the room 90. ) Can be reduced. Hereinafter, these n (n = 1,2 ...) on the standing wave SW ₁ of the longest wavelength lambda ₁ of the first-order mode having one of the standing wave _SW n of the following modes (n = 1,2 ...) Attention is paid to the reason why the standing wave SW ₁ is reduced by the standing wave reducing panel 10.

As shown in FIG. 4, the wavelength λ ₁ of the standing wave SW ₁ of the primary mode generated in the room 90 is twice the distance D 1 between the walls 1 and 2. Then, the standing wave SW _{1 in} the first-order mode passes through the gaps G 1 and G 2 between the acoustic structure row 11 and the walls 1 and 2 in the standing wave reducing panel 10, and the cavity 26 of the acoustic structure row 11. 'Enters into -N. Here, if the length of the cavity 26 '-N D1' is approximately the same as the distance D1 between the walls 1 and 2 of the room 90, the resonant frequency of the cavity 26 '-N also substantially the frequency of the standing wave SW ₁ Be the same. Therefore, in this case, the standing wave SW ₁ is incident into the cavity 26 '-N, resonance phenomenon occurs in the cavity 26'-N. When a resonance phenomenon occurs in the cavity 26 ′ -N, the standing wave SW _{1 ′} having substantially the same frequency as the standing wave SW _{1 and} whose phase is rotated by 180 degrees with respect to the standing wave SW ₁ is converted into the cavity 26 ′. -N is emitted from gaps G1 and G2. As a result, in the vicinity of the gaps G1 and G2, the sound waves SW ₁ and SW ₁ ′ having opposite wavelengths and substantially the same wavelengths λ ₁ and λ ₁ ′ cancel each other. As a result, the standing wave SW ₁ in the room 90 is reduced.

According to the embodiment described above, the standing wave reduction panel 10 having the cavity 26 ′ -N that reduces the standing wave SW ₁ of the room 90 can be easily obtained by connecting an appropriate number of acoustic structures 6. Can be made. In addition, according to the present embodiment, the standing wave reduction panel 10 that is most suitable for reducing standing waves in a room having various shapes and sizes different from those of the room 90 is adapted to the sizes and shapes of various rooms. Compared with the preparation of many types of acoustic structures 6, it can be made at a lower cost.

Second Embodiment
FIG. 5 is a perspective view showing an acoustic structure 6A according to the second embodiment of the present invention. This acoustic structure 6A is a pair of two acoustic structures 6 (FIG. 3), and the acoustic structure 6 forming the pair intersects the extending direction of each cavity 26-N (N = 1 to 5). It is laminated so as to make it.

In the present embodiment, a number of acoustic structures 6A that can occupy almost the entire surface of the interior ceiling 5 when arranged along the interior ceiling 5 of the room 90 are arranged in a lattice shape so as to satisfy the following two conditions. Is fixed under the interior ceiling 5 as a standing wave reducing panel 10.
a1. The cavities 26-N of the upper acoustic structures 6 in the adjacent acoustic structures 6A along the direction between the walls 1 and 2 are connected to form one cavity 26'-N.
b1. The cavities 26-N of the lower acoustic structures 6 in the acoustic structures 6A adjacent to each other along the direction between the walls 3 and 4 are connected to form one cavity 26'-N.

  According to this embodiment, the following effects can be obtained. In the room 90, the standing wave in the direction between the walls 1 and 2 (X direction), the standing wave in the direction between the walls 4 and 5 (Y direction), and the direction between the interior ceiling 5 and the floor 71 (Z Direction) standing wave. According to the acoustic structure 6A, among these three kinds of standing waves, there are standing waves in the direction between the walls 1 and 2 (X direction) and standing waves in the direction between the walls 4 and 5 (Y direction). Removed (mitigated). Also, since furniture and fixtures are usually placed on the floor 71 in the room 90, the standing wave in the direction (Z direction) between the interior ceiling 5 and the floor 71 is compared without using a special sound absorbing material. Easily removed (relaxed). Therefore, by providing the acoustic structure 6 </ b> A in the room 90, it is possible to almost completely suppress all standing waves generated in the room 90. When there is no object in the room 90 that promotes the removal (relaxation) of the standing wave in the direction between the interior ceiling 5 and the floor 71 (Z direction), a diffuser (irregularity on the surface facing the wall surface of the acoustic structure 6A A reflector having a shape and a sound absorbing material may be appropriately installed.

<Third Embodiment>
FIG. 6A is a perspective view showing an acoustic structure 6B according to the third embodiment of the present invention. The cavity 26-N (N = 1 to 5) of the acoustic structure 6B is surrounded by trapezoidal side surfaces 61 and 62 having the same dimensions and rectangular side surfaces 63 and 64 having two types of long and short dimensions, Opening surfaces at one end and the other end of the cavity 26-N (N = 1 to 5) intersect with the longer side surface 64 of the rectangular side surfaces 63 and 64 at an acute angle.

  As shown in FIG. 6 (B), in this embodiment, an odd number (5 in the example of FIG. 6 (B)) acoustic structures 6B are connected to the cavities 26-N of the adjacent acoustic structures 6B. The acoustic structure row 11 is defined as one cavity 26'-N and the side 63 and the side 64 connected so that the top and bottom are alternately arranged. A standing wave is obtained by fixing one or a plurality of acoustic structure rows 11 below the interior ceiling 5 with the side surface 64 of the acoustic structure 6B closest to the walls 1 and 2 facing the interior ceiling 5. The reduction panel 10 is used.

  In the present embodiment, when each of the acoustic structures 6 connected as the acoustic structure row 11 is fixed under the interior ceiling 5 of the room 90, the position of the acoustic structure 6B closest to the wall 1 is determined. When positioning is performed so that the end of the side surface 64 of the acoustic structure 6B is in contact with the wall 1, a gap G1 ′ is formed between the end of the side surface 63 of the acoustic structure 6B and the wall 1. When the position of the acoustic structure 6B closest to the wall 2 is positioned so that the end of the side surface 64 of the acoustic structure 6B is in contact with the wall 2, the end of the side surface 64 of the acoustic structure 6B and the wall 2 A gap G2 ′ is formed between them. Therefore, according to the present embodiment, the standing wave reduction panel 10 can be efficiently installed. In addition, the standing wave reduction panel 10 can be installed so that the interior ceiling 5 cannot be seen from the wall surface side of the room 90.

<Fourth embodiment>
FIG. 7A is a perspective view showing an acoustic structure 6C according to the fourth embodiment of the present invention. The cavity 26-N (N = 1 to 5) of the acoustic structure 6C is surrounded by the parallelogram-shaped side surfaces 65 and 66 having the same size and the rectangular side surfaces 67 and 68 having the same size. The opening surface at one end of the cavity 26-N (N = 1 to 5) is one of the side surfaces 67 and 68, and the opening surface at the other end of the cavity 26-N (N = 1 to 5) is the side surface. Each of 67 and 68 intersects the other side surface 68 at an acute angle.

  As shown in FIG. 7B, in this embodiment, a plurality of (six in the example of FIG. 7B) acoustic structures 6C are connected to the cavities 26-N of the adjacent acoustic structures 6C. An acoustic structure row 11 is formed by connecting the side 67 and the side 68 so that the tops and bottoms thereof are aligned. The standing wave reduction panel 10 is obtained by fixing one or a plurality of acoustic structure rows 11 below the interior ceiling 5 of the room 90.

  In the present embodiment, when each of the acoustic structures 6 connected as the acoustic structure row 11 is fixed under the interior ceiling 5 of the room 90, the position of the acoustic structure 6B closest to the wall 1 is determined. When positioning is performed so that the end of the side surface 67 of the acoustic structure 6B is in contact with the wall 1, a gap G1 "is formed between the end of the side surface 68 of the acoustic structure 6B and the wall 1. Therefore, according to the present embodiment. The standing wave reduction panel 10 can be efficiently installed.

<Fifth Embodiment>
FIG. 8 is a view of a state in which the standing wave reduction panel 90 according to the fifth embodiment of the present invention is provided on the ceiling side of the room 10 as viewed from the side of the room 90. In this embodiment, i × j acoustic structures 6 constituting the standing wave reduction panel 10 are installed with a space from the interior ceiling 5 of the room. In this embodiment, each of the i × j acoustic structures 6 is fixed below the interior ceiling 5 of the room 90 in the following manner.

  In the first mode, as shown in FIG. 9, suspension bolts 40, 41, 42, 43 are erected slightly inside the four corners of the side surface 23 of the acoustic structure 6, and the suspension bolts 40, 41, The upper ends of 42 and 43 are fixed to the interior ceiling 5. In this aspect, an annular rubber or the like is wound around the outer ends of the side surfaces 21, 22, 23, and 24 of the acoustic structure 6 so that the boundary portion between the cavities 26 -N of the adjacent acoustic structures 6 is sealed. Turn it.

  In the second mode, as shown in FIG. 10, the end portions of the acoustic structure 6 are connected by a suspension member 7 having a housing frame 37 that can accommodate the ends of the acoustic structure 6. The housing frame 37 is configured such that plates 33 and 34 arranged in the left-right direction are interposed between plates 31 and 32 arranged in the vertical direction. Here, the interval between the plate 31 and the plate 32 in the housing frame 37 is slightly wider than the thickness between the side surfaces 23 and 24 of the acoustic structure 6, and the interval between the plate 33 and the plate 34 is the side surface of the acoustic structure 6. It is slightly wider than the width between 21 and 22. Therefore, the end of the acoustic structure 6 can be accommodated in the accommodation frame 37. In addition, hanging bolts 35 and 36 are erected slightly inside the end of the upper plate 31 in the housing frame 37. In this embodiment, the plurality of suspension members 7 are suspended from the interior ceiling 5 with the length of one side of the side surfaces 23, 24 of the acoustic structure 6. Then, the end of one acoustic structure 6 is fitted from one of the housing frames 37 of each suspension member 7, and the end of the other acoustic structure 6 is fitted from the other of the housing frames 37. In this aspect, the inside of the housing frame 37 may be sealed with rubber or the like so that the boundary portion between the cavities 26-N of the two acoustic structures 6 fitted into the housing frame 37 from both sides is sealed.

  In the present embodiment, the acoustic structure row 11 in the standing wave panel 10 is not directly joined to the interior ceiling 5 itself, but via the suspension bolts 40, 41, 42, 43 and the suspension member 7. Install below. Therefore, a sound absorbing material such as glass wool or plate-like material is placed in the space between the acoustic structure row 11 having a width corresponding to the length of the suspension bolts 40, 41, 42, 43 and the suspension member 7 and the interior ceiling 5. Can be installed. Therefore, the standing wave which causes booming in the room 90 can be removed by the acoustic structure 6, and the remaining frequency components from which the standing wave has been removed can be adjusted by the sound absorbing material.

  Furthermore, in this embodiment, since the acoustic structure row 11 is provided with a space below the interior ceiling 5, the noise from the upper floor is increased by the amount of the sound insulation performance of the sound insulation layer constituted by the acoustic structure row 11. Therefore, the noise is reduced.

The first to fifth embodiments of the present invention have been described above. However, the present invention may have other embodiments. For example, it is as follows.
(1) In the first to fifth embodiments, the plurality of acoustic structures 6 are fixed below the interior ceiling 5 of the room 90. However, a plurality of acoustic structures 6 may be fixed between the interior ceiling 5 and the floor 71 in any of the walls 1, 2, 3, 4 of the room 90.

(2) In the first to fifth embodiments, the acoustic structure 6 has five cavities 26-N (N = 1 to 5). However, the number of cavities in the acoustic structure 6 may be four or less, or may be six or more.
(3) In the first to fifth embodiments, it is not necessary to fix the acoustic structure row 11 below the interior ceiling 5 in a posture orthogonal to the space between the opposing walls 1 and 2. For example, the acoustic structure 11 may be fixed below the interior ceiling 5 such that the extending directions of the cavities 26-N (N = 1 to 5) obliquely intersect the walls 1 and 2.

(4) In the first to fifth embodiments, the standing wave reduction panel 10 has a plurality of acoustic structure rows 11 arranged along the interior ceiling 5 of the room 90. However, one acoustic structure row 11 may be used as the standing wave reduction panel 10. Moreover, what was arranged in the state which adjacent acoustic structure row | line | columns 11 in the some acoustic structure row | line | column 11 contacted is good also as the standing wave reduction panel 10, and adjoining acoustic structure body 6 is separated. It is good also as what is arranged in the state made into the standing wave reduction panel 10. FIG.

(5) In the third embodiment, at least one of the angles θ1 and θ2 formed by the side surfaces 64 and the opening surfaces of the one end and the other end of the cavity 26-N (N = 1 to 5) of the acoustic structure 6B. The angle should be more than 45 degrees. FIG. 11A shows an acoustic structure 6B ′ in which both angles θ1 and θ2 exceed 45 degrees, and is installed so that the end of the side face 64 contacts the wall 1 of the room 90. It is the figure seen from the wall 3 side of the room 90. FIG. FIG. 11B is a view of the acoustic structure 6 </ b> B ′ viewed from the wall 1 side of the room 90. FIG. 11C is a view of the acoustic structure 6 </ b> B ′ viewed from the wall surface side of the room 90. As shown in FIGS. 11 (A), 11 (B), and 11 (C), in this acoustic structure 10B ′, the opening surface on the wall 1 side in the cavity 26-N (N = 1 to 5) Since the angle θ1 formed by the side surface 64 exceeds 45 degrees, the width of the gap G1 ′ formed between the end of the side surface 63 and the wall 1 is smaller than the height h of the cavity 26-N. Therefore, in this case, the area S1 of the gap G1 ′ is smaller than the cross-sectional area SH of the cross section perpendicular to the extending direction of the cavity 26-N in the cavity 26-N, and the sound absorption is larger. An effect and a scattering effect can be obtained. For the relationship between the size of the area S1 and the area SH and the sound absorption effect and the scattering effect, refer to Patent Document 2 (particularly, FIG. 9).

(6) In the fourth embodiment, the standing wave reduction panel 10 in which a plurality of acoustic structures 6 </ b> C are connected is fixed under the interior ceiling 5 of the room 90. However, as shown in FIG. 12, an acoustic structure row 11 in which a plurality of acoustic structures 6C are connected is provided in a room 90 ′ from which the interior ceiling 5 is removed, and the standing wave reduction panel 10 and the room 90 ′. The space under the ceiling slab 70 may be separated. When there is another room 90 ″ on the upper floor of the room 90 ′ (above the ceiling slab 70), the floor impact sound (sound mainly composed of the low frequency range) generated in the room 90 ″ passes through the space under the ceiling slab 70. May propagate to room 90 '. By providing the acoustic structure row 11 in which the plurality of acoustic structures 6C are connected to the room 90 ′, a gap G2 in which a floor impact sound is generated between the end of the acoustic structure row 11 on the wall 2 side and the wall 2 is created. ”Is propagated into the cavity 26 ′ -N and the floor impact sound is alleviated. Therefore, according to this embodiment, the standing wave generated in the room 90 ′ and the floor impact sound generated in the room 90 ′ are It can be relaxed and a quiet environment can be realized in the room 90 '. In addition, when there is a room in which a standing wave reduction panel of another specification is installed on the lower floor of the room 90 ', a quiet environment can be realized even in the room on the lower floor.

(7) The acoustic structure 6 </ b> A in the second embodiment is a laminate of two layers of acoustic structures 6. However, three or more acoustic structures 6 may be laminated.

1, 2, 3, 4 ... walls, 5 ... interior ceiling, 6, 6A, 6B, 6C ... acoustic structure, 7 ... suspension member, 10 ... standing wave reduction panel, 11 ... acoustic structure row, 26 ... Cavity 31, 32, 33, 34 ... plate, 37 ... receiving frame 21, 22, 23, 24, 35, 36, 61, 63, 64, 65, 66, 67, 68 ... side, 35, 36, 40 , 41, 42, 43, 44, 45, 46, 47 ... hanging bolts, 70 ... ceiling slab, 71 ... floor, 90 ... room.

Claims (4)

  An acoustic structure having a cavity extending in one direction and opening at one end and the other end in the extending direction, and the acoustic structure when the acoustic structure is connected to another acoustic structure An acoustic structure characterized in that a body cavity and a cavity of another acoustic structure are connected to form one cavity.   2. An acoustic structure comprising two or more layers of the acoustic structure according to claim 1 in a state where the extending directions of the cavities intersect each other.   The acoustic according to claim 1 or 2, wherein an opening surface of an end portion where the cavity is opened in the acoustic structure and one side surface of side surfaces surrounding the cavity of the acoustic structure form an acute angle. Structure. 2. One or a plurality of acoustic structure rows connecting a plurality of acoustic structures according to claim 1 that occupy the entire surface or one surface of the boundary surface of the acoustic space along the boundary surface of the acoustic space. Standing wave reduction panel characterized by being arranged in a row.

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