Sound absorption structure

Abstract

To provide sound absorption structures, which are installed at intervals, and efficiently absorb sound passing through gaps formed between the sound absorption structures.SOLUTION: There are provided sound absorption structures 1A and 1B installed at intervals 100, in which side surfaces 10A and 10B of adjacent sound absorption structures 1A and 1B form the interval 100, and at least one of the side surfaces 10A and 10B is provided with an opening 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sound absorbing structure that is erected at intervals. [Background technology]

[0002] In order to reduce noise over a wide range, multiple sound-absorbing structures capable of absorbing noise are sometimes installed side by side as soundproof walls. Gaps are formed between multiple soundproof walls installed side by side, and these gaps reduce soundproofing performance due to sound passing through the gaps. Therefore, in order to fill the gaps between multiple soundproof walls installed side by side, a structure has been proposed in which boards are attached to the gaps after the soundproof walls are installed to fill the gaps (see, for example, Patent Document 1). Also, in order to fill the gaps between multiple soundproof walls installed side by side, a structure has been proposed in which soundproof walls having interlocking structures are fitted together to fill the gaps (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5956405 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the plate materials are attached after the soundproof wall is erected, the process of attaching the plate materials increases. Furthermore, if the plate materials are attached to the soundproof wall in advance, a margin must be provided to accommodate construction errors outside the soundproof wall surface. When soundproof walls having interlocking structures are interlocked, the interlocking portions must be tightly fitted, which leaves the problem of not being able to adjust the total length of the soundproof walls. Conversely, if a margin is provided to allow for adjustment of the total length, gaps will be created. In other words, when erecting multiple soundproof walls side by side, structures that fill the gaps formed between the soundproof walls by attaching plate materials to them or structures that fill the gaps by interlocking soundproof walls with interlocking structures have issues with the workability and construction of the product. Furthermore, these structures inherently have the problem of reduced soundproofing performance if the gaps formed between the soundproof walls are not completely filled.

[0005] The present invention has been made to solve such problems, and aims to provide a sound-absorbing structure that is erected at intervals and can efficiently absorb sound that passes through the gaps formed between the sound-absorbing structures. [Means for solving the problem]

[0006] The present invention has been made to solve the above problems, and the gist of the present invention is as follows. [1] A sound-absorbing structure that is erected with a gap between them, wherein the side surfaces of adjacent sound-absorbing structures form the gap, and an opening is provided in at least one of the side surfaces. [2] The sound-absorbing structure according to [1], wherein the opening is provided over substantially the entire side surface. [3] The sound absorbing structure according to [1] or [2], wherein the opening has an opening ratio of 20% or more and 70% or less. [4] The sound absorbing structure according to any one of [1] to [3], wherein the interval is 20 mm or less. [5] The sound absorbing structure according to any one of [1] to [4], wherein the thickness of the sound absorbing structure is 100 mm or more and 600 mm or less. [6] The sound-absorbing structure according to any one of [1] to [5], which is installed at the top of a soundproof wall. [Effects of the Invention]

[0007] It is possible to provide a sound absorbing structure that is erected at intervals and can efficiently absorb sound that passes through gaps formed between the sound absorbing structures. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view of a sound absorbing structure according to a first embodiment of the present invention. [Figure 2] 1 is a schematic side view of a sound absorbing structure according to a first embodiment of the present invention. [Figure 3] FIG. 4 is a schematic perspective view of a sound absorbing structure according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic side view of a sound absorbing structure according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram showing the shape of an opening of a sound absorbing structure according to a third embodiment of the present invention. [Figure 6] FIG. 1 is a schematic diagram showing test specimens T1 to T6 prepared for use in the analysis of the examples. [Figure 7] FIG. 1 is a schematic diagram showing an analysis of an example. [Figure 8] 7 is a graph showing the analysis results of the difference in sound attenuation at six observation points for the test specimen T1 in FIG. 6(a) and the test specimen T2 in FIG. 6(b) in Example 1. [Figure 9] 7 is a graph showing the analysis results of the difference in sound attenuation at six observation points for the test specimen T1 in FIG. 6(a) and the test specimen T3 in FIG. 6(c) in Example 2. [Figure 10] 6(d) is a graph showing the analysis results of the difference in sound attenuation at six observation points for the test specimen T1 in FIG. 6(a) and the test specimen T4 in FIG. 6(d) in Comparative Example 1. [Figure 11]6(e) is a graph showing the analysis results of the difference in sound attenuation at six observation points for test specimen T1 in FIG. 6(a) and test specimen T5 in FIG. 6(e) in Comparative Example 2. [Figure 12] 6(f) is a graph showing the analysis results of the difference in sound attenuation at six observation points for the test specimen T1 in FIG. 6(a) and the test specimen T6 in FIG. 6(f) in Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, identical or similar parts are denoted by identical or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. Furthermore, it goes without saying that the drawings also include parts with different dimensional relationships and ratios.

[0010] (First embodiment) The sound absorbing structures 1A and 1B according to the first embodiment of the present invention are sound absorbing structures that are erected with a gap 100 therebetween, as shown in FIG. 1, and the side surfaces 10A and 10B of the adjacent sound absorbing structures 1A and 1B that are erected form the gap 100, and an opening 11 is provided in at least one of the side surfaces 10A and 10B. The sound absorbing structure of the present invention is not limited to the form of a simple planar soundproof wall as shown in Fig. 1, but may be the form of an entire soundproof wall with a plurality of soundproof panels installed above and below, or may be the form of a part of a soundproof wall with a plurality of soundproof panels installed above and below. Furthermore, the sound absorbing structure of the present invention may be installed on the topmost stage of a soundproof wall (see the second embodiment).

[0011] The sound-absorbing structures 1A and 1B have the function of separating the compartments, thereby reducing noise generated in one compartment in the other compartment. The sound-absorbing structures 1A and 1B are equipped with sound-absorbing material inside, and exert a sound-absorbing effect by introducing sound into the interior. The sound-absorbing material provided in the sound-absorbing structures 1A and 1B is not particularly limited, but examples thereof include dry materials such as glass wool, rock wool, felt, synthetic fibers, and metal fibers, as well as wet materials such as urethane foam and putty. The sound-absorbing material may be a dry material or a wet material used alone, and is preferably at least one selected from the group consisting of glass wool, rock wool, felt, and urethane foam. Of the dry materials, those that deform when they absorb moisture, such as glass wool, are preferably water-repellent.

[0012] The sound absorbing structures 1A and 1B are erected at an interval D1 of 100 along the direction in which a road or a railway track is laid (X-axis direction), for example. The width D1 is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. By having the width D1 be equal to or less than the above upper limit, the construction can be improved by providing a gap, and the sound passing through the gap can be reduced, thereby improving the sound absorption effect. The thickness T1 of the sound absorbing structures 1A, 1B is preferably 25 mm or more, more preferably 50 mm or more, and even more preferably 100 mm or more. Furthermore, the thickness T1 of the sound absorbing structures 1A, 1B is preferably 300 mm or less, more preferably 200 mm or less, and even more preferably 150 mm or less. By keeping the thickness T1 of the sound absorbing structures 1A, 1B within the above range, the sound absorbing structures 1A, 1B can efficiently absorb noise from a sound source while maintaining their rigidity and durability. The thickness T1 of the sound absorbing structures 1A, 1B refers to the thickness in the direction perpendicular to the installation direction (Y-axis direction).

[0013] It is sufficient that the opening 11 is provided in at least one of the side surface portions 10A, 10B of the sound absorbing structures 1A, 1B, and it is preferable that the opening 11 is provided in both the side surface portions 10A, 10B. The shape of the opening 11 may be any of a round hole, a rectangular hole, an elongated hole, etc. The openings 11 can be arranged in a regular pattern. For example, as shown in Fig. 2, the openings 11 can be round holes with a diameter of 2 mm to 10 mm, with a pitch P1 in the direction perpendicular to the installation direction (Y-axis direction) of 5 mm to 15 mm, and a pitch P2 in the height direction (Z-axis direction) of 10 mm to 20 mm. By arranging the openings 11 in this regular pattern, the sound absorption effect in the side portions 10A and 10B can be made uniform across the entire surface.

[0014] From the viewpoint of improving the sound absorbing effect, it is preferable that the openings 11 are provided over substantially the entire side surface portions 10A, 10B. Examples of the side surface portions 10A, 10B include punched metal and wire mesh that have a large number of openings 11 and that are provided over substantially the entire side surface portions 10A, 10B. From the viewpoint of durability, metals are preferred for the components constituting the sound absorbing structures 1A, 1B other than the side portions 10A, 10B, and particularly, plated steel sheets such as highly corrosion-resistant plated steel sheets and hot-dip galvanized steel sheets are preferred. Specific examples of highly corrosion-resistant plated steel sheets include Superdyma steel sheets (registered trademark) and ZAM steel sheets. The components constituting the sound absorbing structures 1A, 1B other than the side portions 10A, 10B may be painted or otherwise treated to improve corrosion resistance.

[0015] The opening ratio of the openings 11 in the side portions 10A, 10B is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more. The opening ratio of the openings 11 in the side portions 10A, 10B is preferably 70% or less, more preferably 65% or less, and even more preferably 60% or less. When the opening ratio of the openings 11 in the side portions 10A, 10B is within the above range, the sound absorbing structure 1 can efficiently absorb noise from the sound source while maintaining its rigidity and durability. The aperture ratio of the openings 11 in the side surface portions 10A and 10B is the ratio of the area of the openings 11 to the area of the entire surface including the openings 11 when the side surface portions 10A and 10B are viewed in plan.

[0016] According to the sound-absorbing structure of the first embodiment, sound passing through the gaps formed between the sound-absorbing structures is introduced into the sound-absorbing structure by openings provided on the side surfaces, thereby absorbing noise efficiently. Furthermore, with the sound-absorbing structure according to the first embodiment, it is only necessary to arrange the structures in a line with a space between them, thereby eliminating the need for precise processing or difficult construction work, and making installation work easy.

[0017] [Second embodiment] The second embodiment differs from the first embodiment in that sound absorbing structures 2A and 2B are installed on the topmost stage of a soundproof wall 1C, as shown in Fig. 3. Differences between the first embodiment and the second embodiment will be described below. In the following description of different embodiments, members having the same configuration will be assigned the same reference numerals.

[0018] The sound-absorbing structures 2A and 2B are installed on the topmost level of the soundproof walls 1C and 1D, and are therefore higher by the height of the sound-absorbing structures 2A and 2B, allowing them to efficiently absorb diffracted sound that diffracts from the upper parts of the soundproof walls 1C and 1D. The sound-absorbing structures 2A and 2B are equipped with sound-absorbing material inside, and exert their sound-absorbing effect by introducing sound into the interior. The sound-absorbing materials provided in the sound-absorbing structures 2A and 2B are not particularly limited, but examples include dry materials such as glass wool, rock wool, felt, synthetic fibers, and metal fibers, as well as wet materials such as urethane foam and putty. The sound-absorbing material may be a dry material or a wet material used alone, and is preferably at least one selected from the group consisting of glass wool, rock wool, felt, and urethane foam. Of the dry materials, those that deform when they absorb moisture, such as glass wool, are preferably water-repellent.

[0019] The sound absorbing structures 2A and 2B are erected with a width D2 in the direction in which a road or a railway track is laid (X-axis direction), for example. The width D2 is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. When the width D2 is equal to or less than the above upper limit, the construction can be improved by providing a gap, and the sound passing through the gap can be reduced, thereby improving the sound absorption effect. The thickness T2 of the sound absorbing structures 2A, 2B is preferably 100 mm or more, more preferably 150 mm or more, and even more preferably 200 mm or more. Furthermore, the thickness T2 of the sound absorbing structures 2A, 2B is preferably 600 mm or less, more preferably 550 mm or less, and even more preferably 500 mm or less. By keeping the thickness T2 of the sound absorbing structures 2A, 2B within the above range, the sound absorbing structures 2A, 2B can efficiently absorb noise from the sound source while maintaining their rigidity and durability. The thickness T2 of the sound absorbing structures 2A, 2B refers to the thickness in the direction perpendicular to the installation direction (Y-axis direction).

[0020] It is sufficient that the opening 21 is provided in at least one of the side surface portions 20A, 20B of the sound absorbing structures 2A, 2B, and it is preferable that the opening 21 is provided in both of the side surface portions 20A, 20B. The shape of the opening 21 may be any of a round hole, a rectangular hole, an elongated hole, etc. The openings 21 can be arranged in a regular pattern. For example, as shown in Fig. 4, the openings 21 can be round holes with a diameter of 2 mm to 10 mm, with a pitch P3 in the direction perpendicular to the installation direction (Y-axis direction) of 5 mm to 15 mm, and a pitch P4 in the height direction (Z-axis direction) of 10 mm to 20 mm. By arranging the openings 21 in this regular pattern, the sound absorption effect of the side portions 20A and 20B can be made uniform across the entire surface.

[0021] From the viewpoint of improving the sound absorbing effect, it is preferable that the openings 21 are provided over substantially the entire side surface portions 20A, 20B. Examples of the side surface portions 20A, 20B include punched metal and wire mesh that have a large number of openings 21 and that are provided over substantially the entire side surface portions 20A, 20B. From the viewpoint of durability, metals are preferred for the components constituting the sound absorbing structures 2A, 2B other than the side portions 20A, 20B, and particularly, plated steel sheets such as highly corrosion-resistant plated steel sheets and hot-dip galvanized steel sheets are preferred. Specific examples of highly corrosion-resistant plated steel sheets include Superdyma steel sheets (registered trademark) and ZAM steel sheets. The components constituting the sound absorbing structures 2A, 2B other than the side portions 20A, 20B may be painted or otherwise treated to improve corrosion resistance.

[0022] The opening ratio of the openings 21 in the side portions 20A, 20B is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more. The opening ratio of the openings 21 in the side portions 20A, 20B is preferably 70% or less, more preferably 65% or less, and even more preferably 60% or less. When the opening ratio of the openings 21 in the side portions 20A, 20B is within the above range, the sound absorbing structure 1 can efficiently absorb noise from the sound source while maintaining its rigidity and durability. The aperture ratio of the openings 21 of the side surface portions 20A, 20B is the ratio of the area of the openings 21 to the area of the entire surface including the openings 21 when the side surface portions 20A, 20B are viewed in plan.

[0023] The sound absorbing structure according to the second embodiment can provide the same effects as those of the first embodiment. Furthermore, according to the sound absorbing structure of the second embodiment, the sound absorbing structure is installed on the topmost stage of the soundproof wall, and therefore can efficiently absorb diffracted sound that diffracts from the upper part of the soundproof wall.

[0024] [Third embodiment] The third embodiment differs from the first embodiment in that the openings 12 provided in the side portions 10A, 10B of the sound absorbing structures 1A, 1B have a louvered shape, as shown in Figures 5(a) and 5(b). Differences between the first embodiment and the third embodiment will be described below. In addition, in the following description of different embodiments, components having the same configuration will be assigned the same reference numerals.

[0025] As shown in Figure 5(b), the louver shape of the opening 12 is, for example, inclined from the fulcrum 12A of the side portion 10A of the sound absorbing structure 1A so as to face the sound source 40, so that the sound emitted from the sound source 40 is reflected by the louver portion and efficiently introduced into the inside of the sound absorbing structure 1A, thereby enhancing the sound absorption effect.

[0026] The louver-shaped members of the opening 12 can be made of a rigid and durable material, such as metals such as iron, steel, and aluminum; resins such as polyethylene, polypropylene, and polybutene; and wooden plywood. Metals are preferred for the louver-shaped members of the opening 12, and plated steel sheets such as highly corrosion-resistant plated steel sheets and hot-dip galvanized steel sheets are particularly preferred. Specific examples of highly corrosion-resistant plated steel sheets include Superdyma Steel Sheet (registered trademark) and ZAM (registered trademark) steel sheets. Metals are preferred for the material of the louver-shaped members of the opening 12, and aluminum sheets are particularly preferred because of their rigidity and light weight. The louver-shaped members of the opening 12 may be painted to improve corrosion resistance.

[0027] The sound absorbing structure according to the third embodiment can provide the same effects as those of the first embodiment. Furthermore, with the sound absorbing structure according to the third embodiment, the openings have a louver shape, so that sound from the sound source can be efficiently absorbed.

[0028] [Other embodiments] The present invention is not limited to the configurations of the first to third embodiments described above, and any improvements and modifications may be made without departing from the technical spirit of the present invention.

[0029] For example, in the explanation of the second embodiment, the sound absorbing structures 2A and 2B are installed on the topmost tiers of the soundproof walls 1C and 1D, but the sound absorbing structures 1A and 1B of the first embodiment may be used as the soundproof walls 1C and 1D. In other words, the first and second embodiments can be combined, and by doing so, a better sound absorbing effect can be achieved. [Example]

[0030] The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. The sound absorbing structure of the present invention is evaluated as follows.

[0031] <Evaluation method> Test specimens T1 to T6, as shown in Figures 6(a) to (f), were created to confirm the differences in performance between them. Specifically, as shown in Figure 7, the sound (100 dB) generated from the line sound source LS was measured at six observation points (three points (P1, P2, P3) on the extension line L1 of the spacing and three points (P4, P5, P6) on the extension line L2 at the center of the test specimens) using the test specimens T (T1 to T6) to confirm how much the sound was attenuated. Note that the acoustic analysis was performed using Abaqus / Standard2021 with the finite element method. The analysis conditions were set as follows: Air region: density 1.2 kg / m 3 The bulk modulus was set to 0.142 MPa. -Sound absorbing material region: Complex density and complex elastic modulus are given for each frequency. Boundary conditions Boundary B1 (top and bottom of model): Non-reflecting condition (Since sound is completely absorbed, it can be analyzed as if sound passes through boundary 1 and no reflection occurs.) Boundary B2 (left and right faces of the model): Reflection condition (symmetric condition) (By using the center of a 1,800mm span soundproof wall as a reflection surface, analysis can be performed in the same way as if the soundproof wall continued infinitely.) Boundary B3 (steel plate surface): Elastic modulus 200 GPa, Poisson's ratio 0.29, density 7,800 kg / m 3 Boundary B4 (punched metal surface): Opening rate 50%, partial reflection setting

[0032] Details of the test specimens prepared are shown below. The test specimen T1 in FIG. 6(a) is a sound-absorbing structure that has a punched metal exterior, a sound-absorbing material inside, and no gaps, and serves as a benchmark for evaluation. Specimen T2 in FIG. 6(b) is a sound-absorbing structure in which the exterior is a punched metal surface, there is sound-absorbing material inside, and both sides of the side portions that form the gap are punched metal surfaces. Specimen T3 in Figure 6(c) is a sound-absorbing structure with a punched metal exterior, sound-absorbing material inside, and a punched metal surface on one side of the side that forms the gap, and a steel plate surface on the other side of the side that forms the gap. Specimen T4 in Figure 6(d) is a sound-absorbing structure with a punched metal exterior, sound-absorbing material inside, steel plate surfaces on both sides of the side sections that form the gap, and the steel plate surfaces that block the entrance to the gap on the sound source side. Specimen T5 in Figure 6(e) is a sound-absorbing structure with a punched metal exterior, sound-absorbing material inside, steel plate surfaces on both sides of the side surfaces that form the gap, and a fitting structure where the side surfaces that form the gap are fitted together. Specimen T6 in FIG. 6(f) is a sound-absorbing structure with a punched metal exterior, sound-absorbing material inside, and steel plate surfaces on both sides of the side surfaces that form the gap.

[0033] [Example 1] The difference in sound attenuation at six observation points on test specimen T1 in Figure 6(a) and test specimen T2 in Figure 6(b), which were the evaluation criteria, was measured when the test specimen thicknesses were 600mm, 400mm, and 200mm. The graphs showing the results are shown in Figures 8(a), 8(b), and 8(c).

[0034] [Example 2] Figure 9 shows a graph of the difference in sound attenuation at six observation points for test specimen T1 in Figure 6(a) and test specimen T3 in Figure 6(c), which was the evaluation standard, with a test specimen thickness of 600 mm.

[0035] [Comparative Example 1] Figure 10 shows a graph of the difference in sound attenuation at six observation points for test specimen T1 in Figure 6(a) and test specimen T4 in Figure 6(d), which are the evaluation criteria, with a test specimen thickness of 600 mm.

[0036] Comparative Example 2 Figure 11 shows a graph of the results of the difference in sound attenuation at six observation points for test specimen T1 in Figure 6(a) and test specimen T5 in Figure 6(e), which were the evaluation criteria, with a test specimen thickness of 600 mm.

[0037] Comparative Example 3 The difference in sound attenuation at six observation points on test specimen T1 in Figure 6(a) and test specimen T6 in Figure 6(f), which were the evaluation criteria, was measured when the test specimen thicknesses were 600mm, 400mm, and 200mm. The graphs showing the results are shown in Figures 12(a), 12(b), and 12(c).

[0038] In Examples 1 and 2, an opening was provided on at least one of the side surfaces, and the sound attenuation was good, being equivalent to that of a test piece with no gap (ideal condition) (fluctuating around 0 on the vertical axis of the graph). In contrast to this, in Comparative Examples 1 to 3, there was a difference (greater than 0 on the vertical axis of the graph) compared to the test specimen with no gap (ideal state), and sound attenuation was poor. [Explanation of symbols]

[0039] 1, 2: Sound-absorbing structure 10,20: Side part 11, 21, 12: Opening 40: Sound Source 100: Interval

Claims

1. A sound absorbing structure erected at intervals, The side surfaces of the adjacent sound absorbing structures form the gap, A sound-absorbing structure in which an opening is provided in at least one of the side surfaces.

2. The sound absorbing structure according to claim 1 , wherein the opening is provided over substantially the entire side surface.

3. 3. The sound absorbing structure according to claim 1, wherein the opening has an opening ratio of 20% to 70%.

4. 3. The sound absorbing structure according to claim 1, wherein the spacing is 20 mm or less.

5. 3. The sound absorbing structure according to claim 1, wherein the sound absorbing structure has a thickness of 100 mm or more and 600 mm or less.

6. 3. The sound-absorbing structure according to claim 1, which is installed at the top of a soundproof wall.

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