Sound absorption structure

Abstract

To provide a sound absorption structure with a simpler structure, which provides sound absorption property equal to or greater than a conventional structure.SOLUTION: A sound absorption structure 1 incudes: an undulation structure part 10; and an outer peripheral end 20 surrounding an outer periphery of the undulation structure part 10. The undulation structure part 10 includes: undulating faces 11 for forming undulating faces; and undulating back faces 12 for forming undulating faces opposite to the undulating faces 11. The undulating faces 11 and the undulating back faces 12 form a plurality of projecting parts 30. The undulation structure part 10 includes: a first vibration resonance system 2 and a second vibration resonance system 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sound absorbing structure, and more particularly to a plate-shaped sound absorbing structure. [Background technology]

[0002] Conventionally, various soundproof structures have been proposed for soundproofing. Among these soundproof structures are plate-shaped soundproof panels used in walls, etc. Some soundproof panels have a sound-absorbing structure that exhibits sound-absorbing properties (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-99319 Summary of the Invention [Problem to be solved by the invention]

[0004] A conventional soundproof panel with sound-absorbing properties and a sound-absorbing structure is composed of multiple components each made of different materials. Therefore, the weight of a conventional soundproof panel is the total weight of the multiple components. Since a soundproof panel is used while being supported, if the soundproof panel is heavy, the structure supporting the soundproof panel must be strong. In addition, a certain number of processes are required to manufacture a conventional soundproof panel made of multiple components. A large number of manufacturing processes can lead to increased manufacturing costs.

[0005] For this reason, there is a demand for a sound absorbing structure that has a simpler configuration than conventional soundproof panels and has sound absorbing properties equal to or higher than conventional soundproof panels.

[0006] The present invention has been made in view of the above-mentioned problems, and its object is to provide a sound-absorbing structure that has a simpler configuration and provides sound-absorbing properties equal to or higher than conventional structures. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the sound-absorbing structure of the present invention comprises an undulating structure portion and an outer peripheral end portion which is a portion surrounding the outer periphery of the undulating structure portion, the undulating structure portion having an undulating surface which forms an undulating surface and an undulating back surface which faces away from the undulating surface and also forms an undulating surface, the undulating surface and the undulating back surface form a plurality of protruding portions, and the undulating structure portion comprises a first vibration resonance system and a second vibration resonance system.

[0008] In a sound absorbing structure according to one aspect of the present invention, the undulating structure is vibrable relative to the outer peripheral end, and each of the plurality of protrusions is vibrable.

[0009] In the sound absorbing structure according to one aspect of the present invention, the plurality of protrusions are arranged adjacent to each other.

[0010] In the sound absorbing structure according to one aspect of the present invention, the plurality of protrusions have the same shape.

[0011] In the sound absorbing structure according to one aspect of the present invention, the plurality of protrusions have a plurality of different shapes.

[0012] In the sound absorbing structure according to one aspect of the present invention, the undulating surface and the undulating rear surface of each of the plurality of protrusions form a pyramidal surface.

[0013] In the sound absorbing structure according to one aspect of the present invention, the undulating structure is a member formed from a plate-like member. [Effects of the Invention]

[0014] The sound absorbing structure according to the present invention can have a sound absorbing property equal to or higher than that of conventional structures with a simpler configuration. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a schematic configuration of a sound absorbing structure according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective cross-sectional view showing a part of a cut sound absorbing structure. [Figure 3] FIG. 2 is a perspective cross-sectional view showing a part of a cut sound absorbing structure. [Figure 4] FIG. 4 is a diagram showing a protrusion provided on the sound absorbing structure as seen from the front side. [Figure 5] FIG. 2 is a schematic diagram showing a first vibration resonance system provided in the sound absorbing structure. [Figure 6] FIG. 4 is a schematic diagram showing a second vibration resonance system provided in the sound absorbing structure. [Figure 7] FIG. 10 is a perspective cross-sectional view showing a modified example of the sound absorbing structure. [Figure 8] FIG. 10 is a perspective cross-sectional view showing another modified example of the sound absorbing structure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is a perspective view showing the schematic configuration of a sound-absorbing structure 1 according to an embodiment of the present invention, and FIGS. 2 and 3 are perspective cross-sectional views showing a cut portion of the sound-absorbing structure 1. FIGS. 1 and 3 show the sound-absorbing structure 1 as viewed from the front, and FIG. 2 shows the sound-absorbing structure 1 as viewed from the rear. As shown in FIGS. 1 to 3, the sound-absorbing structure 1 includes an undulating structure 10 and an outer peripheral edge 20 that surrounds the outer periphery of the undulating structure 10. The undulating structure 10 includes a undulating surface 11 that forms an undulating surface, and a undulating back surface 12 that forms an undulating surface facing away from the undulating surface 11. The undulating surface 11 and the undulating back surface 12 form a plurality of protruding portions 30. The undulating structure 10 includes a first vibration resonance system 2 and a second vibration resonance system 3. The configuration of the sound-absorbing structure 1 will be described in detail below.

[0018] 1 to 3, for the sake of convenience, the direction in which the undulating surface 11 faces is referred to as the sound source side, and the direction in which the undulating back surface 12 faces is referred to as the fixed side. In addition, in the drawings, not all of the multiple components are labeled with reference numerals, and the reference numerals of some of the multiple components may be omitted.

[0019] In the sound-absorbing structure 1, for example, the configuration that forms the first vibration resonance system 2 includes a configuration that forms the second vibration resonance system 3. Specifically, for example, the undulating structure 10 is vibrable relative to the outer peripheral end 20, and the undulating structure 10 forms the first vibration resonance system 2. Furthermore, each of the multiple protrusions 30 of the undulating structure 10 is vibrable, and each of the multiple protrusions 30 forms the second vibration resonance system 3. Specifically, the undulating structure 10 is capable of membrane vibration relative to the outer peripheral end 20, and the first vibration resonance system 2 is configured as a vibration resonance system that includes a vibration resonance system in which a resonance phenomenon occurs due to the membrane vibration of the undulating structure 10. Furthermore, each of the multiple protrusions 30 is capable of membrane vibration, and the second vibration resonance system 3 is configured as a vibration resonance system that includes a vibration resonance system in which a resonance phenomenon occurs due to the membrane vibration of each protrusion 30. In the sound absorbing structure 1, the second vibration resonating system 3 overlaps the first vibration resonating system 2 in the undulating structure portion 10.

[0020] As shown in FIGS. 1 to 3, the undulating structure 10 is a plate-like member, and the undulating surface 11 and the undulating back surface 12 are back-to-back with each other. The undulating structure 10 has a width between the undulating surface 11 and the undulating back surface 12. In other words, the undulating structure 10 has a thickness. The thickness of the undulating structure 10 is, for example, uniform or approximately uniform throughout the undulating structure 10. As shown in FIGS. 1 and 3, the undulating surface 11 is undulating, and more specifically, multiple locations on the undulating surface 11 protrude toward the sound source. As shown in FIGS. 2 and 3, the undulating back surface 12 is undulating corresponding to the undulating surface 11, and multiple locations on the undulating surface 11 are recessed toward the sound source. In this way, multiple protrusions 30 are formed in the undulating structure 10 by the undulations of the undulating surface 11 and the undulating back surface 12. As shown in FIGS. 1 to 3, the multiple protrusions 30 are arranged adjacent to each other. The plurality of protrusions 30 form, for example, a plurality of rows.

[0021] As shown in FIGS. 1 and 2, the outer peripheral edge 20 is the outer peripheral edge of the sound-absorbing structure 1 and is a ring-shaped frame that surrounds the undulating structure 10 from the outer periphery. The outer peripheral edge 20 has a rectangular or substantially rectangular ring shape, as shown in FIG. 1, for example. Specifically, as shown in FIGS. 1 to 3, the outer peripheral edge 20 has a pair of end pieces 21 and 22 and another pair of end pieces 23 and 24. The end pieces 21 and 22 are plate-like portions that extend along a linear direction a (the direction of arrow a in FIG. 1) and face each other. The end pieces 23 and 24 are plate-like portions that extend along a linear direction b (the direction of arrow b in FIG. 1) that is perpendicular to the linear direction a along which the end pieces 21 and 22 extend and face each other. The end piece 23 extends between one end of each of the end pieces 21 and 22, and the end piece 24 extends between the other end of each of the end pieces 21 and 22.

[0022] As shown in FIGS. 1 to 3 , the multiple protrusions 30 are arranged, for example, along the outer peripheral edge 20. Specifically, for example, the multiple protrusions 30 are arranged so as to form multiple rows in the extending directions of the end pieces 21 and 22 and the end pieces 23 and 24. That is, the multiple protrusions 30 are arranged along the linear direction a to form one row in the linear direction a, and multiple rows of the multiple protrusions 30 in the linear direction a are arranged in the linear direction b. Furthermore, each of the multiple protrusions 30 forming the multiple rows in the linear direction a is arranged along the linear direction b to form one row in the linear direction b, and multiple rows of the multiple protrusions 30 in the linear direction b are arranged in the linear direction a. In this way, the multiple protrusions 30 in the undulating structure 10 are arranged in a matrix.

[0023] As shown in Figures 1 to 3, the multiple protrusions 30 have the same shape. For example, the shape of the protrusions 30 is pyramidal. That is, in each of the multiple protrusions 30, the undulating surface 11 and the undulating back surface 12 form a pyramidal surface. Specifically, for example, as shown in Figures 1 to 3, the shape of the multiple protrusions 30 is a quadrangular pyramid. That is, in each of the multiple protrusions 30, the undulating surface 11 and the undulating back surface 12 form a quadrangular pyramidal surface.

[0024] 1 to 3, there is no gap between two adjacent protrusions 30 on the sound source side. That is, on the undulating surface 11, there is no gap between a quadrangular pyramidal surface forming a protrusion 30 and a quadrangular pyramidal surface forming a protrusion 30 adjacent to this protrusion 30, and the base of a quadrangular pyramidal surface overlaps with the base of a quadrangular pyramidal surface adjacent to this quadrangular pyramidal surface. On the other hand, as shown in FIG. 2, the undulating back surface 12 has a lattice surface 13 that is a lattice-like surface, and the quadrangular pyramidal surfaces forming the multiple protrusions 30 on the undulating back surface 12 each extend from a multiple of openings 14 arranged in a matrix defined by the lattice surface 13. Note that there may be a gap between two adjacent protrusions 30 on the sound source side.

[0025] 4 is a diagram showing the protruding portion 30 as seen from the front side. As shown in FIGS. 1 to 4, the protruding portion 30 has a plurality of plate-like portions 31, which are plate-like portions along a plane. Specifically, for example, the protruding portion 30 has a quadrangular pyramid shape, and the protruding portion 30 has four triangular plate-like portions 31.

[0026] The undulating structure 10 and the outer peripheral edge 20 are integrally connected, and the sound-absorbing structure 1 is integrally formed from an elastic material. The elastic material from which the sound-absorbing structure 1 is made is, for example, a thermoplastic resin. Specific examples of elastic materials from which the sound-absorbing structure 1 is made include expanded polypropylene, expanded styrene, and soft polyvinyl chloride. The sound-absorbing structure 1 is formed, for example, by vacuum molding or blow molding using a thermoplastic resin sheet. Note that the elastic material from which the sound-absorbing structure 1 is made is not limited to a thermoplastic resin. The elastic material from which the sound-absorbing structure 1 is made may be, for example, another resin, rubber, or the like.

[0027] The sound-absorbing structure 1 is used with its outer peripheral edge 20 fixed to a member to which the sound-absorbing structure 1 is attached. The sound-absorbing structure 1 has the configuration described above, and the undulating structure 10 is a flexible plate. That is, the undulating structure 10 has a planar lattice surface 13 extending therethrough, and the rigidity of the lattice surface 13 is lower than the rigidity of the protruding portions 30, so that the lattice surface 13 of the undulating structure 10 as a whole is more likely to undergo membrane vibration toward the sound source side and the fixed side. Therefore, the undulating structure 10 is capable of membrane vibration toward the sound source side and the fixed side. The sound-absorbing structure 1 also has the configuration described above, and each of the multiple protruding portions 30 has multiple flexible plate-like portions 31. Therefore, in each protruding portion 30, each of the multiple plate-like portions 31 is capable of membrane vibration.

[0028] In this way, in the sound-absorbing structure 1, the entire undulating structure 10 forms a first vibration resonance system 2. In other words, the entire undulating structure 10 resonates at a specific frequency, acting as an inertial mass to absorb sound of the corresponding frequency. In addition, in the sound-absorbing structure 1, each of the multiple protrusions 30 forms a second vibration resonance system 3. In other words, in each protrusion 30, the four plate-like portions 31 resonate at a specific frequency, acting as an inertial mass to absorb sound of the corresponding frequency. In this way, the sound-absorbing structure 1 has two types of membrane vibration systems in the undulating structure 10, and can absorb sound in two different frequency ranges.

[0029] The relief structure 10 extends wider than the plate-like portions 31 of each protrusion 30. Furthermore, in each protrusion 30, each plate-like portion 31 is constrained at its end by the adjacent plate-like portions 31. Therefore, the relief structure 10 as a whole is more flexible and has lower elasticity than the plate-like portions 31 of the protrusions 30, and thus resonates at a lower frequency than the plate-like portions 31 of the protrusions 30. The resonant frequency of the relief structure 10 as a whole can be changed to various frequencies. For example, the resonant frequency of the relief structure 10 as a whole can be changed by varying the thickness of the lattice surfaces 13 of the relief structure 10, the size of the area over which the relief structure 10 extends, the size of the openings 14 in the lattice surfaces 13, and other factors.

[0030] On the other hand, the plate-like portion 31 of each protrusion 30 is constrained by the adjacent plate-like portion 31, and the area of the plate-like portion 31 is smaller than the area of the undulating structure portion 10, so that each plate-like portion 31 of each protrusion 30 resonates at a high frequency. The resonant frequency of the plate-like portion 31 can be changed to various frequencies. For example, the resonant frequency of the plate-like portion 31 can be changed by changing the height or size of the protrusion 30.

[0031] FIG. 5 is a schematic diagram showing the first vibration resonance system 2, and FIG. 6 is a schematic diagram showing the second vibration resonance system 3. FIG. 5 shows the vibration of the entire undulating structure 10. In FIG. 5, the darker the color, the larger the amplitude. Thus, in the first vibration resonance system 2, the central portion of the undulating structure 10 vibrates more. On the other hand, FIG. 6 shows the vibration of each of the plate-like portions 31 of the multiple protrusions 30. In FIG. 6, the darker the color, the larger the amplitude. Thus, in the second vibration resonance system 3, the central portion of each plate-like portion 31 vibrates more.

[0032] As described above, the sound absorbing structure 1 has a simple structure in which the undulating structure 10 and the outer peripheral edge 20 are integrated into a single plate. Furthermore, the sound absorbing structure 1 has two different vibration resonance systems, the first vibration resonance system 2 and the second vibration resonance system 3, which are overlapped in the undulating structure 10, and is simply configured by overlapping two different sound absorbers. Therefore, the sound absorbing structure 1 can achieve high sound absorption with a simple configuration.

[0033] Furthermore, the resonant frequency of the first vibration resonant system 2 can be set to various frequencies depending on the shape of the undulating structure 10, and the resonant frequency of the second vibration resonant system 3 can be set to various frequencies depending on the shape of the protrusions 30. Therefore, the sound-absorbing structure 1 can absorb a wide range of sounds in the low frequency range, and can also absorb a wide range of sounds in the high frequency range. In this way, the sound-absorbing structure 1 can achieve sound absorption characteristics over a wide range of frequencies from low to high, and can be effective against a variety of target sounds.

[0034] Furthermore, the sound absorbing structure 1 can be easily made from a single material by vacuum molding, blow molding, etc. Therefore, the manufacturing cost of the sound absorbing structure 1 is low.

[0035] Furthermore, in each protrusion 30, the multiple plate-like portions 31 are each constrained by the adjacent plate-like portions 31, increasing the rigidity of the protrusion 30. The undulating structure 10 also has multiple protrusions 30. As a result, the rigidity of the entire undulating structure 10, in terms of its shape, is higher than the rigidity of a flat, plate-like member. Furthermore, the sound-absorbing structure 1 has a simple configuration and can be made lightweight. This allows the strength of the members that hold the sound-absorbing structure 1 to be reduced. This allows the configuration of the members that hold the sound-absorbing structure 1 to be simplified, and the cost of installing the sound-absorbing structure 1 to be reduced.

[0036] Furthermore, the sound-absorbing structure 1 can absorb a large amount of sound in a small space. In other words, the sound-absorbing structure 1 can exert a high sound-absorbing effect in a small space. In this way, the space required for installation of the sound-absorbing structure 1 is small, and the sound-absorbing structure 1 can be applied to spaces and partitions of various shapes. Furthermore, because the sound-absorbing structure 1 exerts a high sound-absorbing effect, it can exert a high sound-absorbing effect in spaces and partitions of various shapes.

[0037] Furthermore, by making the undulating structure 10 and the outer peripheral edge 20 of the sound-absorbing structure 1 from a transparent resin, the sound-absorbing structure 1 can be made transparent. For this reason, the sound-absorbing structure 1 can be suitably used in spaces where transparency and lighting should be ensured in the partitions of the walls, ceiling, floor, etc., such as spaces separated by glass partitions or spaces with transparent light-receiving windows in the ceiling.

[0038] As described above, the sound absorbing structure 1 according to the embodiment of the present invention can achieve sound absorbing properties equal to or higher than conventional structures with a simpler configuration.

[0039] The multiple protrusions 30 of the undulating structure 10 are not limited to having the same shape. For example, the undulating structure 10 may have protrusions 30 of various sizes. This allows the sound absorbing structure 1 to have a wider range of sound absorbing characteristics.

[0040] Furthermore, the plurality of protrusions 30 are not limited to the quadrangular pyramid shape described above. For example, the shape of the plurality of protrusions 30 may be a pyramid shape other than a quadrangular pyramid shape. Furthermore, the shape of the plurality of protrusions 30 does not have to be a pyramid shape, and may be, for example, a rectangular prism shape. As an example, the shape of the plurality of protrusions 30 may be, for example, a quadrangular prism shape that is trapezoidal in side view as shown in FIG. 7, or may be a hexagonal prism shape (honeycomb shape) as shown in FIG. 8. In this way, the shape of the plurality of protrusions 30 may be various types of shapes.

[0041] Furthermore, the plurality of protrusions 30 may not have a single type of shape, but may have multiple types of shapes. For example, some of the plurality of protrusions 30 may have the above-mentioned quadrangular pyramid shape, and other parts of the plurality of protrusions 30 may have a shape other than a quadrangular pyramid shape. Furthermore, the plurality of protrusions 30 may have three or more types of shapes.

[0042] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0043] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components illustrated in different embodiments may be partially substituted or combined within the scope of technical inconsistency. Furthermore, the various configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects. [Explanation of symbols]

[0044] 1 sound absorbing structure, 2 first vibration resonance system, 3 second vibration resonance system, 10 undulating structure portion, 11 undulating surface, 12 undulating back surface, 13 lattice surface, 14 opening, 20 outer peripheral edge portion, 21, 22, 23, 24 end pieces, 30 protrusion portion, 31 plate-shaped portion

Claims

1. An undulating structure; an outer peripheral edge portion that is a portion surrounding the outer periphery of the undulating structure portion, The undulating structure portion has an undulating surface that forms an undulating surface, and an undulating back surface that forms an undulating surface and is opposite to the undulating surface, the undulating surface and the undulating back surface form a plurality of protruding protrusions; the relief structure comprises a first vibration resonating system and a second vibration resonating system; Sound-absorbing structure.

2. the relief structure is vibrable relative to the outer peripheral edge, Each of the plurality of protrusions is vibrable. The sound absorbing structure according to claim 1 .

3. The plurality of protrusions are adjacent to each other. The sound absorbing structure according to claim 1 .

4. The plurality of protrusions have the same shape. The sound absorbing structure according to claim 1 .

5. The plurality of protrusions have a plurality of types of shapes. The sound absorbing structure according to claim 1 .

6. In each of the plurality of protrusions, the undulating surface and the undulating back surface form a pyramidal surface. The sound absorbing structure according to claim 1 .

7. The undulating structure is a member formed from a plate-like member. The sound absorbing structure according to claim 1 .

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