JP2017008553A - Sound absorption structure and sound proof room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sound absorption performance with a simple structure.SOLUTION: A sound absorption structure (1) includes a back surface part (21) having a length in a predetermined direction, a front surface part (22) disposed in parallel with the back surface part (21) and away from the back surface part (21) frontward, and a sound absorption member disposed between the back surface part (21) the front surface part (22). The front surface part (22) has an opening (23) through which sound passes, and a sound absorption member (3) is arranged at least behind a reflection wall part (220) excluding the opening (23) in the front surface part (22).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sound absorbing structure and a soundproof room, and more particularly to a sound absorbing structure suitable for an audio room and a soundproof room equipped with the sound absorbing structure.

  In a room (audio room) whose main purpose is to play a musical instrument such as a piano or listen to music, not only soundproofing but also good sounding (sound) is required. One of the methods for producing good sound is “sound absorption”. Conventionally, there are sound-absorbing ceiling materials, sound-absorbing wall materials, wall-mounted or stationary sound-absorbing panels, and the like.

  For example, in Japanese Patent Application Laid-Open No. 2005-146650 (Patent Document 1), in order to absorb sound of a specific frequency in an air layer existing between double walls, a plurality of Helmholtz resonances are provided in a stud provided in a wall space. A sound absorbing structure that forms a vessel has been proposed. Specifically, the stud is composed of a hollow tube extending in the vertical direction, a plurality of openings that open to the space in the wall are provided on the side of the stud, and the periphery of the opening is the other part. Further, it is disclosed to form a cylindrical shape that protrudes more sideways.

  In addition, it is known in the architectural acoustics industry that it is effective to place a sound-absorbing material in the corner to reduce the acoustic disturbance of booming, where bass sounds accumulate in the corner of the room and the sound balance is poor. ing. For example, in Japanese Patent Application Laid-Open No. 2014-141822 (Patent Document 2), a substantially triangular prism-shaped sound absorber is arranged at a corner portion of a soundproof room, and a low-frequency sound is absorbed by a thick part, and a thin part. A technology for absorbing high-frequency sounds has been proposed. In addition, in this document, in order to make the sound variable, it is also proposed to add a variable mechanism that makes the exposed area of the sound absorption surface (surface) of the sound absorber variable.

  In JP-A-8-53887 (Patent Document 3), an opening is provided in the surface material of the wall of the acoustic chamber, and a sound absorbing box containing a sound absorbing material is inserted into the wall thickness from the opening. Thus, a wall structure that exhibits a sound absorbing effect by utilizing the thickness of the wall is disclosed.

JP 2005-146650 A JP 2014-141822 A JP-A-8-53887

  In order to improve the sound absorption performance of the substantially triangular prism-shaped sound absorber installed at the corner as in Patent Document 2, the size of the sound absorber may be increased. However, if the size of the sound absorber in the corner portion is too large, not only the space in the room is narrowed but also not desirable in terms of design, so that the practicality is poor. Also, in the wall structure of Patent Document 3, since the sound absorbing material is disposed only behind the opening provided in the surface material, it is necessary to increase the wall thickness in order to sufficiently exhibit the sound absorbing effect. .

  Moreover, since the technique of the said patent document 1 requires the pillar of a special structure, the technique which improves a sound absorption performance with a simple structure was calculated | required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sound absorbing structure and a soundproof room capable of improving sound absorbing performance with a simple structure.

  A sound absorbing structure according to an aspect of the present invention is a sound absorbing structure for absorbing sound, and is disposed in a predetermined direction in a predetermined length in a rear surface portion, parallel to the rear surface portion, and spaced forward from the rear surface portion. And a sound absorbing material disposed between the rear surface portion and the front surface portion. The front surface portion is provided with an opening for allowing sound to pass therethrough, and the sound absorbing material is disposed at least behind the reflection wall portion excluding the opening of the front surface portion.

  Preferably, the reflection wall portion and the opening portion are adjacent to each other in a predetermined direction.

  Preferably, the sound absorbing material is also disposed behind the opening. In this case, the ratio of the opening dimension of the opening and the length dimension of the reflecting wall in the predetermined direction is desirably 1: 3.

  It is desirable that the sound absorbing structure further includes an opening / closing mechanism for enabling the opening to be closed, and the sound absorption rate is made variable by opening / closing the opening / closing mechanism.

  A soundproof room according to another aspect of the present invention includes at least one side wall having any one of the above sound absorbing structures, and a position on the side wall that reflects the sound that is close to the sound source and is emitted from the sound source, on the front surface portion, and the sound source An opening is provided at both the position far from the center.

  According to the present invention, the sound absorption performance can be improved with a simple structure. Moreover, since it is not necessary to increase the thickness of the sound absorbing material, practicality can be improved.

It is sectional drawing which shows typically the soundproof room which concerns on Embodiment 1 of this invention. It is the figure which looked at the soundproof room which concerns on Embodiment 1 of this invention from the indoor side (from the direction of arrow II of FIG. 1). It is a figure which shows typically the cross-sectional structure of the sound-absorbing material contained in the sound-absorbing structure according to Embodiment 1 of the present invention. It is a figure which shows typically the structure of the sound absorption structure which concerns on Embodiment 1 of this invention. It is a graph which shows the experimental result about the sound absorptivity of the sound of a low frequency range which compared the sound absorption structure which concerns on Embodiment 1 of this invention, and another wall structure. It is a figure which shows the structure of the wall structure of a comparative example. It is a figure which shows the structure of the wall structure of a comparative example. It is a figure which shows the structure of the wall structure of a comparative example. It is a graph which shows the experimental result about the sound absorption characteristic from the low sound to the high sound which compared the sound absorption structure which concerns on Embodiment 1 of this invention, and another wall structure. It is a figure which shows the structure of the wall structure of a comparative example. It is a figure which shows the structure of the wall structure of a comparative example. It is a figure which shows typically an example of the base member of the sound absorption structure which concerns on Embodiment 1 of this invention. (A), (B) is a figure which shows typically the other example of the base | substrate member of the sound absorption structure which concerns on Embodiment 1 of this invention. It is a figure which shows typically a 125Hz sound wave. It is sectional drawing which shows typically the sound-absorption structure which concerns on Embodiment 2 of this invention, (A) shows the bass sound variable mechanism of a full open state, (B) shows the bass sound variable mechanism of a fully closed state. Show. It is a graph which shows the relationship between the material of the partition member which comprises a bass sound variable mechanism, and a sound absorption effect. It is sectional drawing which shows typically the sound absorption structure which concerns on the modification of Embodiment 2 of this invention. It is a graph which shows the relationship between the angle change of the partition member which comprises a bass sound variable mechanism, and the sound absorption property of a bass. It is a figure which shows typically the sound absorption structure which concerns on Embodiment 3 of this invention. It is a figure which shows typically the soundproof room which concerns on Embodiment 4 of this invention. It is a figure which shows typically the soundproof room which concerns on Embodiment 5 of this invention. (A), (B) is a figure which shows notionally the usage pattern of the soundproof room which concerns on Embodiment 5 of this invention. (A), (B) is a figure which shows notionally the other usage pattern of the soundproof room which concerns on Embodiment 5 of this invention. It is the figure which looked at the soundproof room which concerns on other embodiment of this invention from the room inner side. It is a perspective view which shows the sound absorbing device which concerns on other embodiment of this invention. It is sectional drawing which shows typically the sound absorption structure which concerns on other embodiment of this invention. It is sectional drawing which shows typically the sound absorption structure which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Embodiment 1>
First, the outline of the soundproof room according to the present embodiment will be described. In the present embodiment, the side closer to the sound source (the center side of the room) is called “front”, and the far side is called “rear”.

  1 and 2, the soundproof room 9 is a room surrounded by a floor 91, side walls 92 to 95, and a ceiling 96. In the present embodiment, for example, one side wall 92 has a sound absorbing structure 1 for absorbing sound generated indoors. The sound absorbing structure 1 includes a rear surface portion 21, a front surface portion 22, and a sound absorbing material 3 for absorbing sound.

  The rear surface portion 21 has a rectangular shape and has a length in the vertical direction and the horizontal width direction. The rear surface portion 21 is orthogonal to the side walls 93 and 95 of the soundproof room 9. The rear surface portion 21 is made of a rigid face material.

  The front surface portion 22 is disposed in parallel with the rear surface portion 21 and spaced forward from the rear surface portion 21. The front surface portion 22 is also rectangular and has a length in the vertical direction and the horizontal width direction. An arrow A1 in FIG. 2 indicates the horizontal width direction.

  The front surface portion 22 is provided with an opening 23 as a sound intake. The front surface portion 22 allows sound to pass through the opening portion 23 and reflects sound at the other main body portion (hereinafter referred to as “reflection wall portion”) 220. The reflection wall 220 is also made of a rigid face material. The reflection wall 220 and the opening 23 are disposed adjacent to each other in the lateral width direction. It is desirable that the opening 23 extends in the vertical direction.

  In the present embodiment, both the rear surface portion 21 and the reflection wall portion 220 of the front surface portion 22 constitute the side wall 92. That is, the side wall 92 of the soundproof room 9 is a double wall.

  In the present embodiment, the opening 23 extends from the upper end position of the front surface portion 22 to the lower end position. The opening 23 is provided at one end of the front surface portion 22 in the width direction. In this case, the opening 23 may be formed by making the width of the face material itself constituting the reflection wall 220 shorter than the rear face 21. If the face material constituting the rear face portion 21 is referred to as a “rear face member” and the face material constituting the reflecting wall portion 220 is referred to as a “front face member”, the front face member is wider than the rear face member. And the opening is formed at a position adjacent to the front surface member in the lateral width direction.

  The sound absorbing material 3 is provided between the rear surface portion 21 and the front surface portion 22. Specifically, the sound absorbing material 3 includes a region 24 (hereinafter referred to as “first region”) located behind the opening 23 in the front surface portion 22 and a reflection wall portion 220 in the front surface portion 22. It is provided in both the area 25 (hereinafter referred to as “second area”) located behind. The first area 24 and the second area 25 constitute a front area of the rear surface portion 21.

  In this case, the sound absorbing material 3 is located in the first region 24, is located in the portion exposed in the room from the opening 23 (hereinafter referred to as “exposed sound absorbing portion”) 31, and is located in the second region 25, and is a reflective wall It is composed of a portion (hereinafter referred to as “back sound absorbing portion”) 32 hidden by the portion 220. It is desirable that the exposed sound absorbing portion 31 and the back sound absorbing portion 32 be adjacent to each other. That is, it is desirable that the sound absorbing material 3 extends from the first region 24 to the second region 25. Even when the opening 23 does not extend from the upper end position to the lower end position of the front surface portion 22, it is desirable that the rear sound absorbing portion 32 is adjacent to the exposed sound absorbing portion 31 also in the vertical direction.

The sound absorbing material 3 may be composed of a general sound absorbing body such as glass wool or rock wool, or may be composed of a layered sound absorbing body composed of a plurality of layer members as shown in FIG. In FIG. 3, a plurality of layer members are arranged so that layers are formed in the thickness direction in both the exposed sound absorbing portion 31 and the back sound absorbing portion 32. Each layer member is formed by, for example, intricately intertwining PET (Polyethylene terephthalate) fibers, and the density thereof is, for example, 30 kg / m ³ .

  According to the present embodiment, the surface of the reflection wall portion 220 of the front surface portion 22 and the surface of a part of the sound absorbing material 3 (exposed sound absorbing portion 31) are exposed in the room (soundproof chamber 9). Therefore, a part of the sound generated in the room is reflected by the reflection wall part 220 and the other part is incident on the exposed sound absorbing part 31 of the sound absorbing material 3 through the opening 23 and is absorbed.

  Here, in the present embodiment, since the sound absorbing material 3 has the back sound absorbing portion 32 adjacent to the exposed sound absorbing portion 31 in the lateral width direction, the sound in the high sound range (hereinafter also simply referred to as “high sound”) is A sound in the low sound range (hereinafter also simply referred to as “low sound”) absorbed by the exposed sound absorbing portion 31 can be diffracted into the second region 25 and absorbed by the back sound absorbing portion 32. Therefore, the sound absorbing material 3 can absorb a wide range of sounds while suppressing the thickness of the sound absorbing material 3.

  Next, the configuration (size or ratio) of the sound absorbing structure 1 that can appropriately absorb low sounds in the sound absorbing material 3 and can absorb sound in a balanced manner from low to high sounds will be described. FIG. 4 is a diagram illustrating a configuration example of the sound absorbing structure 1 according to the present embodiment.

  As shown in FIG. 4, in the present embodiment, the opening dimension D1 of the opening 23 is 0.5P, and the horizontal width dimension (hereinafter also referred to as “reflection wall dimension”) D2 of the reflecting wall 220 is 1 .5P. 1P represents one module in the design of the building, and indicates 910 mm or 1000 mm. The opening dimension (D1) of the opening 23 is read as the width dimension of the first area 24 (the length dimension of the first area 24 in a predetermined direction), and the reflection wall dimension (D2) is the width dimension of the second area 25 ( It may be read as “the length dimension of the second region 25 in a predetermined direction).

  The thickness D3 of the sound absorbing material 3 is, for example, 100 mm. The thickness dimension D3 is also equal to the depth dimension of the first region 24 and the second region 25. In FIG. 4, the thickness is shown large for convenience. In the present embodiment, it is assumed that the exposed sound absorbing portion 31 and the back sound absorbing portion 32 have the same thickness, but the exposed sound absorbing portion 31 may protrude forward by the thickness of the reflection wall portion 220. A decorative panel (not shown) may be attached to the surface of the exposed sound absorbing portion 31.

  The sound absorbing performance of the sound absorbing structure 1 having such a configuration will be described with reference to experimental results using a comparative example. In the experiment, a layered sound absorber as shown in FIG. 3 is used as the sound absorber 3.

  First, with reference to FIGS. 5 to 8, the sound absorption performance (sound absorption power) of the sound absorption structure 1 will be described. FIG. 5 shows a result of an experiment on the sound absorption of the sound in the low frequency range, comparing the sound absorbing structure 1 according to the present embodiment with another wall structure. 6 to 8 show configurations of wall structures 101 to 103 of comparative examples, respectively. In this experiment, the width of the front surface portion 22 is fixed to 2P, and only the opening dimension D1 of the opening 23 is changed.

  The sound absorbing structure 1 according to the present embodiment is a “¼ sound absorbing” wall structure because the opening dimension D1 is 0.5P. The wall structure 101 shown in FIG. 6 has a “1/2 sound absorption” wall structure because the opening dimension D1 is 1P. In the wall structure 102 shown in FIG. 7, the reflection wall 220 is not provided, and all the sound absorbing material 3 is exposed from the opening 123. The wall structure 102 is an “all sound absorbing” wall structure because the opening size is 2P. The wall structure 103 shown in FIG. 8 is a “no sound absorption” wall structure because the opening 23 is not provided.

  In the graph of FIG. 5, compared with the “no sound absorption” wall structure 103 of FIG. 8, the sound level of the low to medium sound (125 to 1000 Hz) is shown for each of the sound absorption structure 1 and the wall structures 101 and 102. It is shown as a sound pressure level (unit: dB).

  In the “total sound absorption” wall structure 102 in FIG. 7, the low sound absorption coefficient is considerably lower than the medium sound absorption coefficient. Further, in the “1/2 sound absorption” wall structure 101 of FIG. 6, the sound absorption coefficient of the bass is slightly improved as compared with the wall structure 102, but the sound absorption coefficient of the medium sound is still higher. On the other hand, the sound absorption structure 1 of “¼ sound absorption” according to the present embodiment is further improved in the sound absorption rate of the low sound, and is similar to the sound absorption rate of the medium sound.

  From the above results, it can be seen that the sound absorbing structure 1 having the opening dimension D1 of 0.5P has excellent bass sound absorbing performance.

  Next, the sound absorption balance of the sound absorbing structure 1 will be described with reference to FIGS. FIG. 9 shows a result of an experiment on sound absorption characteristics from low to high, by comparing the sound absorption structure 1 according to the present embodiment with another wall structure. 10 and 11 show the structures of the wall structures 104 and 105 of the comparative example, respectively. From the above experimental results on the sound absorption of bass, it has been found that the opening dimension D1 is preferably 0.5P. In this experiment, the opening dimension D1 is fixed to 0.5P, and the opening dimension D1 and the reflection are reflected. Only the ratio with the wall dimension D2 is changed.

  In the sound absorbing structure 1 according to the present embodiment, the ratio between the opening dimension D1 and the reflecting wall dimension D2 is 1: 3. In the wall structure 104 shown in FIG. 10, the ratio of the opening dimension D1 to the reflecting wall dimension D2 is 1: 1, and the opening 23 having an opening dimension of 0.5P is formed at both lateral ends of the front surface portion 22. Each is provided. In the wall structure 105 shown in FIG. 11, the ratio of the opening dimension D1 to the reflection wall dimension D2 is 1: 2.

  In the graph of FIG. 9, compared with the “no sound absorption” wall structure 103 of FIG. 8, the sound intensity of the sound absorption structure 1 and the wall structures 104 and 105 is from low to high (125 to 4000 Hz). It is shown as a sound pressure level (unit: dB).

  In the wall structure 104 of “sound absorption 1: reflection 1” in FIG. 10, the sound pressure level decreases as the sound becomes higher, and the sound absorption balance is not good. Further, in the “sound absorption 1: reflection 2” wall structure 105 of FIG. 11, the sound absorption balance is improved as compared with the wall structure 101, but the sound pressure level of the high sound is still lower. On the other hand, the sound absorbing structure 1 of “sound absorption 1: reflection 3” according to the present embodiment shows a substantially constant sound pressure level from low to high and has a flat sound absorption characteristic.

  From the above results, it can be seen that the sound absorbing structure 1 in which the ratio of the opening dimension D1 to the reflecting wall dimension D2 is 1: 3 can absorb sound in a balanced manner from low to high.

  In order to pass the sound in the horizontal width direction through the second region 25 (the back sound absorbing portion 32), the base member that supports the rear surface portion 21 and the reflecting wall portion 220 of the front surface portion 22 is in the horizontal width direction. It must have a portion that penetrates. Specifically, for example, the base member 4 as shown in FIG. 12 or the base member 4A as shown in FIG. 13 may be employed. In FIGS. 12 and 13, the illustration of the sound absorbing material 3 is omitted.

  The base member 4 has a plurality of cutouts 40 penetrating in the lateral width direction at intervals in the vertical direction. In FIG. 12, the notch 40 faces the front surface portion 22 side, but the notch 40 may face the rear surface portion 21 side.

  As shown in FIG. 13B, the base member 4A has a plurality of vertical bars 41 and a plurality of horizontal bars 42, and is formed in a sword shape. In this case, as shown in FIG. 13A, for example, the vertical rail 41 is in contact with the reflecting wall portion 220 of the front surface portion 22 and the horizontal rail 42 is in contact with the rear surface portion 21.

  As described above, according to the sound absorbing structure 1 of the present embodiment, the back sound absorbing portion 32 is configured to absorb bass, so that the thickness of the sound absorbing material 3 can be suppressed. Therefore, since the space in the soundproof room 9 can be widely used, practicality and design can be improved. In addition, an excellent sound absorbing performance can be realized with a simple structure. As a result, in the soundproof room 9 provided with the sound absorbing structure 1, it is possible to create a comfortable sound, so that the soundproof room 9 can be provided as a comfortable audio room.

  In addition, the following structures may be sufficient as the structure (size or ratio) of the sound absorption structure 1 with which the soundproof room 9 is equipped.

  The ratio between the opening dimension D1 of the opening 23 and the reflecting wall dimension D2 may be 1: 2. That is, when the opening dimension D1 is 1, it is desirable that the reflection wall dimension D2 is 2 or more. In the experimental result shown in FIG. 9, even the wall structure 105 of “sound absorption 1: reflection 2” showed a relatively well-balanced sound absorption characteristic. Alternatively, the reflection wall dimension D2 may simply be longer than the opening dimension D1.

  Although it is considered that the sound absorption coefficient of each sound range varies depending on the material and density of the sound absorbing material 3, the horizontal width dimension of the back sound absorbing portion 32, that is, the reflection wall dimension D2, is 1 / th of the sound wave in the low frequency range (125 Hz). Two or more wavelengths are sufficient. FIG. 14 shows the length (1/2 wavelength) W1, specifically about 1.5P. Further, it is desirable that the thickness dimension (D3) of the back sound absorbing portion 32, that is, the depth dimension of the second region 25 is 100 mm or more.

  However, even when the depth dimension of the second region 25 (and the first region 24) is larger than 100 mm, the lateral width dimension of the back sound absorbing portion 32 that absorbs low sounds, that is, the reflection wall dimension D2, is at least an exposure that absorbs high sounds. It is longer than the thickness dimension D3 of the sound absorbing portion 31, that is, the depth dimension of the first region 24 (and the second region 25).

<Embodiment 2>
Next, the sound absorbing structure of the soundproof room according to Embodiment 2 of the present invention will be described. In the present embodiment, the sound absorbing structure has a function of changing the sound in the low sound range.

  15A and 15B are cross-sectional views schematically showing a sound absorbing structure 1A according to the second embodiment. The basic configuration of the sound absorbing structure 1A is the same as that of the sound absorbing structure 1 shown in the first embodiment. Therefore, only differences from the sound absorbing structure 1 of the first embodiment will be described below.

  The sound absorbing structure 1 </ b> A includes a bass sound variable mechanism 5. The bass sound variable mechanism 5 changes the sound absorption coefficient of the bass by adjusting the opening area (hereinafter referred to as “passage area”) of the low-frequency sound passage from the first region 24 into the second region 25. Can do. That is, the sound in the low sound range can be made variable.

  The bass sound variable mechanism 5 can be typically realized by a plate-shaped partition member 51. The partition member 51 has, for example, a width equal to or greater than the depth dimension of the first region 24 and the second region 25, and substantially the same length as their height dimension (the height from the floor 91 to the ceiling 96 shown in FIG. 2). Have Such a partition member 51 is inserted from the end of the opening 23 into the boundary surface 26 between the first region 24 and the second region 25 or in the vicinity thereof so as to divide the sound absorbing material 3. The passage area can be reduced. In this case, the sound absorbing material 3 is provided with a cut or a gap for inserting the partition member 51 in the thickness direction.

  In the state of FIG. 15A, since the partition member 51 is not inserted into the boundary surface 26, the passage area of the bass is the maximum and is in a fully opened state. In this case, as shown in the first embodiment, the low sound is sufficiently absorbed similarly to the high sound. On the other hand, in the state of FIG. 15B, since the partition member 51 is completely inserted into the boundary surface 26, the passage area of the bass is zero (minimum) and is in a fully closed state. In this case, since the sound absorption rate of the low sound is reduced, the low sound is increased indoors. In order to allow the partition member 51 to be easily inserted and removed, rails (not shown) may be provided on the floor 91 and the ceiling 96 of the soundproof room 9, for example. Alternatively, in order to facilitate insertion and removal of the partition member 51, the partition member 51 may be divided into a plurality of parts in the vertical direction.

  In order for the partition member 51 to effectively block or reduce the passage of bass to the second region 25, the partition member 51 is preferably a rigid plate-like member. This will be described with reference to the experimental results shown in FIG.

  FIG. 16 is a graph showing the relationship between the material of the partition member 51 and the sound absorption effect. In this experiment, the material of the partition member 51 was changed, and the partition member 51 was completely inserted as shown in FIG.

  From the experimental results shown in FIG. 16, it can be seen that the low sound absorption coefficient is not so low with a rigid vinyl sheet, but the low sound absorption coefficient is low with a rigid plywood or styrene board as intended. In addition, it is clear from this experimental result that, even if the partition member 51 has rigidity, even if the low-passage passage is fully closed by the partition member 51, it does not affect the sound absorption property of high frequencies of 1000 Hz or higher. It has become.

  As described above, according to the present embodiment, the low-frequency sound can be made variable, so that the sound absorption structure 1A can function like a woofer or a subwoofer by intentionally lowering the low-frequency sound absorption rate. it can. Therefore, comfortable sound can be created according to the type of musical instrument used.

  Although the vertical length of the partition member 51 is substantially the same as the height dimension of the boundary surface 26, it may be shorter than that. That is, the partition member 51 may be configured to partially open the bass passage even in the fully closed state.

  Further, the bass sound variable mechanism 5 may have other configurations. A modification of the bass sound variable mechanism 5 will be described.

(Modification)
FIG. 17 is a cross-sectional view schematically showing a sound absorbing structure 1B according to a modification of the second embodiment. The sound absorbing structure 1B includes a bass acoustic variable mechanism 5A. The bass acoustic variable mechanism 5 </ b> A includes a partition member 51 as in the bass acoustic variable mechanism 5. However, the arrangement position and the way of adjusting the passage area are different from those of the bass acoustic variable mechanism 5.

  In the bass acoustic variable mechanism 5 </ b> A, the partition member 51 is built in the second region 25. In this case, the bass passage area can be adjusted by rotating the partition member 51. That is, the partition member 51 is provided such that the angle with respect to the lateral width direction is variable. The partition member 51 is desirably provided near the entrance of the second region 25 (near the boundary surface 26 described above).

  In this case, in order to open and close the low-pass passage, the partition member 51 only needs to be able to rotate 90 ° with its center line as the rotation axis. A state in which the direction of the partition member 51 is 90 ° with respect to the lateral width direction (a state in which the partition member 51 is disposed in parallel with the thickness direction as shown in FIG. 15B) is a fully closed state. On the other hand, as shown in FIG. 17, the state in which the direction of the partition member 51 is 0 ° with respect to the lateral width direction is the fully open state.

  FIG. 18 is a graph showing the relationship between the angle change of the partition member 51 and the sound absorption of bass. In this experiment, a plywood having a thickness of 2.5 mm is used as the partition member 51. From the experimental results of FIG. 18, it can be seen that even if the partition member 51 is built in the vicinity of the entrance of the second region 25, the sound absorbing structure 1 </ b> B exhibits a sound absorption characteristic proportional to the angle change of the partition member 51.

  In the bass sound variable mechanism 5 </ b> A, the sound absorbing material 3 may not be provided in the rotation range of the partition member 51 in order to enable the partition member 51 to rotate within the second region 25. That is, as shown in FIG. 17, the second region 25 may be disposed in the cavity 250. The hollow portion 250 is, for example, a region where both sides thereof are separated by a partition bar 52 provided with a space in the vertical direction.

  Further, in order to easily rotate the partition member 51 from the indoor side, the bass acoustic variable mechanism 5 </ b> A may include an operation lever 53 coupled to the rotation shaft of the partition member 51. In this case, an operation opening 221 for exposing a part of the distal end portion of the operation lever 53 may be provided in a part of the reflection wall portion 220 of the front surface portion 22 located in front of the cavity portion 250. .

  In the case where the cavity portion 250 is provided in the second region 25 as in this modification, in order to avoid a slight decrease in the low-frequency sound absorption force in the fully opened state, the width of the cavity portion 250 is reduced. The lateral width dimension of the reflection wall portion 220 of the rear surface portion 21 and the front surface portion 22 may be increased. By doing so, the horizontal width dimension of the back sound absorption part 32 can be made the same as the dimension in the said Embodiment 2. FIG.

<Embodiment 3>
Next, the sound absorbing structure of the soundproof room according to Embodiment 3 of the present invention will be described. In the present embodiment, the sound absorbing structure has a function of changing the sound in the entire sound range.

  FIG. 19 is a diagram schematically illustrating a sound absorbing structure 1C according to the third embodiment. The basic structure of the sound absorbing structure 1C is the same as that of the sound absorbing structure 1 of the first embodiment. Therefore, only the points different from the sound absorbing structure 1 of the first embodiment will be described here.

  The sound absorbing structure 1 </ b> C includes an acoustic variable mechanism 6. The sound variable mechanism 6 can change the sound absorption rate of the entire sound by adjusting the exposed area of the sound absorbing surface exposed from the opening 23 (that is, the surface of the exposed sound absorbing portion 31 or the surface of the decorative panel).

  Specifically, the acoustic variable mechanism 6 is provided in the opening 23, and is composed of a plurality of wing plates 61 like a louver, for example. Each slat 61 extends in the horizontal width direction and can change the angle in the vertical direction. Therefore, the exposed area of the sound absorbing surface of the sound absorbing material 3 can be adjusted by changing the angle of the slat 61. That is, when the entire or part of the sound absorbing surface is closed with the wing plate 61, the sound absorption coefficient of the entire sound is lowered, so that the sound in the entire sound range is increased.

  Therefore, also in the present embodiment, comfortable sound can be created according to the type of musical instrument used.

  The acoustic variable mechanism 6 is not limited to the configuration as shown in FIG. 19 and may be configured by one or a plurality of doors.

<Embodiment 4>
In the first to third embodiments, the soundproof room having a side wall with a width of 2P has been described as an example. However, the sound absorbing structure as described above can also be applied to a soundproof room surrounded by other side walls with a width. . A configuration example of the soundproof room in this case will be described.

  FIG. 20 is a diagram schematically showing a soundproof room 9A according to the fourth embodiment. The soundproof room 9A has side walls 92, 94 having a width of 3P and side walls 93, 95 having a width of 4P.

  In each of the 4P side walls 93 and 95, for example, the sound absorbing structure 1 shown in the first embodiment is set as one unit, and two sound absorbing structures 1 are arranged in the lateral width direction. In the present embodiment, two units in which an opening 23 is provided at one end in the width direction of the front surface portion 22 are arranged. In this case, a partition member 71 for blocking the passage of sound may be provided between the units.

  Alternatively, a unit in which the opening 23 is provided at one end in the width direction of the front surface portion 22 and the other end in the width direction of the front surface portion 22 so that the opening 23 is arranged near the corner portion of the soundproof room 9A. A unit having an opening 23 in the part may be arranged. In any case, the rear surface portion 21 may be continuous.

  Moreover, the 3P side wall 92 is comprised by the sound absorption structure 1D, for example. In the sound absorbing structure 1D, an opening 23 having an opening size of 0.5P is disposed in front of the center of the rear surface portion 21 having a width 3P. That is, the front surface part 22 has the reflection wall part 220 on both sides of the opening part 23. Also in this case, the thickness dimension D3 of the sound absorbing material 3 may be 100 mm or more.

  Thus, when the lateral width of the side wall is larger than 2P, the reflection wall dimension D2 of the front surface portion 22 may be larger than 1.5P.

<Embodiment 5>
In the present embodiment, a soundproof room in which the position of the opening 23 is determined based on the positional relationship with the sound source will be described.

  Referring to FIG. 21, in the soundproof room 9B, each of the pair of side walls 93 and 95 facing each other has a sound absorbing structure 1E. In the sound absorbing structure 1 </ b> E, openings 23 are provided in both the position of the front surface portion 22 that is close to the sound source S and that reflects the sound emitted from the sound source S (including the mirror image sound source) and the position that is far from the sound source S. ing. The surface of the sound absorbing material 3, that is, the sound absorbing surface is exposed from the opening 23.

  Specifically, it is assumed that the sound source S is arranged near the side wall 92. In this case, the front surface part 22 of each side wall 93 and 95 has the opening part 23 in both the edge part near the side wall 92 and the edge part far from the side wall 92, for example.

  Desirably, each opening 23 is provided with a variable acoustic mechanism 6A. The sound variable mechanism 6A is configured by, for example, a door that can be opened and closed. In FIG. 21, the door closer to the sound source S is shown as a door 62, and the door far from the sound source S is shown as a door 63. The doors 62 and 63 may be divided in the vertical direction. When the doors 62 and 63 are closed, the sound absorbing surface (opening 23) is covered, so that the sound emitted from the sound source S does not enter the sound absorbing material 3 and is reflected on the surfaces of the doors 62 and 63.

  When the sound variable mechanism 6 </ b> A is provided in each opening 23, a plurality of usage forms are possible as shown in FIGS. 22 and 23. In these drawings, for easy understanding, a portion of the sound absorbing material exposed from the opening 23 is hatched.

  22A, the door 62 close to the sound source S is closed and the door 63 far from the sound source S is opened on both side walls 93 and 95. In this case, since the sound is reflected around the sound source S and the sound image is widened, the sound reaching the viewer is rich. On the other hand, in the usage pattern of FIG. 22B, the door 63 far from the sound source S is closed and the door 62 close to the sound source S is opened on both side walls 93 and 95. In this case, the sound is absorbed around the sound source S and the sound image becomes sharp, so that the sound reaching the viewer is a clean sound.

  Moreover, all the doors 62 and 63 can be opened as shown in FIG. 23A, or all the doors 62 and 63 can be closed as shown in FIG.

  Thus, according to the present embodiment, sound absorbing surfaces can be arranged at various positions with the sound source S as a reference in one soundproof room 9B. Therefore, the viewer himself can create his / her favorite sound.

  Further, by combining the sound absorbing structure 1E of the soundproof room 9B with the bass sound variable mechanism described in the second embodiment, it is possible to create a more ideal sound.

<Other embodiments>
In the sound absorbing structure of each of the above embodiments, the opening 23 is provided in a part of the front surface part 22 in the horizontal width direction, but may be provided in a part of the front surface part 22 in the vertical direction. In this case, like the side wall 92 shown in FIG. 24, the opening 23 may be provided at the center in the vertical direction.

  Further, in each of the above embodiments, the rear surface portion 21 and the front surface portion 22 (reflection wall portion 220) of the sound absorbing structure constitute the side wall of the soundproof room. However, as shown in FIG. May constitute the floor 91 or the ceiling 96 of the soundproof room. That is, the rear surface portion 21 and the front surface portion 22 of the sound absorbing structure only need to constitute at least one of the side walls 92 to 95, the floor 91, and the ceiling 96 of the soundproof room.

  Alternatively, only the rear surface portion 21 of the sound absorbing structure may constitute at least one of the side walls 92 to 95, the floor 91, and the ceiling 96 of the soundproof room. That is, the reflection wall part 220 of the front surface part 22 may be arrange | positioned only as a reflection panel ahead of the structural surface (rear surface part 21) of a soundproof room.

  Alternatively, the sound absorbing structure shown in each embodiment may not be incorporated in the soundproof room in advance. That is, the sound absorbing structure may be realized as a portable sound absorbing device as shown in FIG.

  Referring to FIG. 25, sound absorbing device 10 has a sound absorbing structure 1F in which a sound absorbing structure 1B according to a modification of the second embodiment and a sound absorbing structure 1C according to the third embodiment are combined, for example. Therefore, the sound absorbing device 10 includes, as an example, a bass sound variable mechanism 5 </ b> A (FIG. 17) and a sound variable mechanism 6. Therefore, the sound absorbing device 10 can change the sound for each sound range (for each frequency). Note that FIG. 25 shows a state in which the acoustic variable mechanism 6 is fully closed.

  In this case, the rear wall portion 21 and the reflection wall portion 220 of the front surface portion 22 constitute a part of the housing of the sound absorbing device 10. The sound absorbing device 10 may be surrounded by the surface members 81 to 84 that block the upper end surface, the lower end surface, and both side surfaces of the sound absorbing material 3 in addition to the rear surface portion 21 and the reflection wall portion 220.

  Also in the sound absorbing device 10, the shapes of the rear surface portion 21 and the front surface portion 22 are both rectangular. When the predetermined direction indicated by the arrow A2 in FIG. 25 is one direction, the length in one direction of the rear surface portion 21 is 2P, and the length in one direction of the reflection wall portion 220 of the front surface portion 22 is 1.5P. It is desirable to be. The length of the rear surface portion 21 and the front surface portion 22 in the other direction (a direction orthogonal to one direction) is desirably 1P or more.

  By installing the sound absorbing device 10 as described above at a desired position in the room, the room can be used like an audio room. The sound absorbing device 10 can also function as an audio tune because the sound can be changed for each sound range. The sound absorbing device 10 may be installed such that the predetermined direction matches the lateral width direction of the side wall of the room, or may be installed so that the predetermined direction matches the vertical direction of the room.

  In the example of the sound absorbing device 10 in FIG. 25, the rear surface portion 21 and the front surface portion 22 have a rectangular shape, but are not limited to such shapes. It is only necessary that the rear surface portion 21 and the front surface portion 22 have a length in at least a predetermined direction, and one or a plurality of openings 23 are provided in a part of the front surface portion 22 in the predetermined direction.

  In the second embodiment, it has been described that the sound absorbing material 3 may be divided when the bass sound variable mechanism is provided. However, the sound absorbing material 3 is divided regardless of the presence or absence of the bass sound variable mechanism. Also good. That is, it is only necessary that the sound absorbing material 3 is provided in both the first region 24 and the second region 25 that constitute the front region of the rear surface portion 21, and the sound absorbing material 3 is provided from the first region 24 to the second region. It does not have to extend to 25. For example, one or more cavities may be provided in the second region 25.

  Moreover, in each said embodiment, although the sound-absorbing material 3 was provided in both the 1st area | region 24 and the 2nd area | region 25, as shown by the sound-absorbing structure 1G of FIG. May be provided only. That is, it is sufficient that the sound absorbing material 3 is disposed at least behind the reflection wall portion 220.

  In the sound absorbing structure 1 </ b> G, a part of the sound incident on the first region from the opening 23 is reflected by the rear surface portion 21, and the remaining part reaches the second region 25. In this case, most of the high sound is reflected, and the low sound is incident on the sound absorbing material 3 provided in the second region 25 from the side surface and absorbed. According to such a sound absorbing structure 1G, compared with the sound absorbing structure 1 of the first embodiment, it is possible to increase the sound pressure level of the high sound while maintaining the sound absorbing performance of the low sound. Therefore, by adopting the sound absorbing structure 1G, it is possible to realize a construction method that absorbs only low frequencies and absorbs low frequencies effectively. In addition, in the sound absorbing structure 1G, when an opening / closing mechanism (for example, a door) for enabling the opening 23 to be closed is provided, the sound absorption rate of the low sound can be changed by opening / closing the opening / closing mechanism.

  As mentioned above, although embodiment of this invention was described, you may combine each said embodiment and modification suitably.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 1A, 1B, 1C, 1D, 1E, 1F, 1G Sound absorbing structure, 3 sound absorbing material, 4, 4A base member, 5, 5A low sound variable mechanism, 6, 6A variable sound mechanism, 9, 9A, 9B Soundproof room DESCRIPTION OF SYMBOLS 10 Sound absorption device, 21 Back surface part, 22 Front surface part, 23, 123 Opening part, 24 1st area | region, 25 2nd area | region, 26 Boundary surface, 31 Exposed sound absorption part, 32 Back sound absorption part, 41 Vertical beam, 42 Horizontal beam, 51 partition member, 52 partition beam, 53 operation lever, 61 wing plate, 62, 63 door, 71 partition material, 81-84 surface member, 91 floor, 92-95 side wall, 96 ceiling, 101-105 wall structure , 220 reflective wall, 221 opening for operation, 250 cavity.

Claims (5)

A sound absorbing structure for absorbing sound,
A rear surface portion having a length in a predetermined direction;
A front surface portion disposed parallel to the rear surface portion and spaced forward from the rear surface portion;
A sound absorbing material disposed between the rear surface portion and the front surface portion;
The front surface portion is provided with an opening for allowing sound to pass through,
The sound absorbing structure, wherein the sound absorbing material is disposed at least behind a reflection wall portion excluding the opening portion of the front surface portion.   The sound absorbing structure according to claim 1, wherein the reflection wall portion and the opening portion are adjacent to each other in the predetermined direction. The sound absorbing material is also disposed behind the opening,
The sound absorbing structure according to claim 2, wherein a ratio of an opening dimension of the opening and a length dimension of the reflection wall in the predetermined direction is 1: 3. An opening / closing mechanism for allowing the opening to be closed;
The sound absorption structure according to any one of claims 1 to 3, wherein the sound absorption rate is variable by opening and closing the opening / closing mechanism. A soundproof room comprising at least one side wall having the sound absorbing structure according to any one of claims 1 to 4,
The soundproof room, wherein the opening is provided in both the front surface portion of the side wall at a position near the sound source and a position where the sound emitted from the sound source is reflected and a position far from the sound source.

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