Soundproofing structure

Abstract

To provide a soundproofing structure that can improve sound insulation and reduce thickness.SOLUTION: An embodiment of the present invention includes: a soundproofing material 10 comprising a sheet 11 having elasticity, a support portion 12 supporting the sheet 11 and dividing the sheet 11 into compartments; and holding members 20 holding the soundproofing material 10, where ten-point average roughness (RzJIS) of a contact surface of the support portion 12 with the sheet 11 is in the range of 20 μm or more to 200 μm or less, and the soundproofing material 10 is pressed between the holding members 20 under pressure greater than atmospheric pressure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a soundproof structure. [Background technology]

[0002] There are many sound sources inside a car. Since quietness from noise both inside and outside the car is required, various soundproofing measures are implemented in cars. In particular, soundproofing measures must be taken near the source of loud noise (intrinsic sound sources) such as the engine, transmission, and drivetrain. For this reason, special soundproofing covers with excellent sound absorption and blocking properties are used to protect against these sound sources.

[0003] Here, with successive legal revisions tightening regulations on exterior noise levels and the fact that quieter interior noise is directly linked to the value (luxury) of a car, there is a very high demand for low-noise automotive parts. In particular, the exterior noise regulations introduced in the European Union (EU) in 2013 are strict, ultimately setting a minimum of -3dB (a reduction of sound pressure energy to half) compared to the previous regulations. This requires noise reduction measures for the engine itself, which is the main source of noise in the engine compartment, and other inherent noise sources such as the transmission.

[0004] Although various soundproofing parts such as engine top covers have been used up until now, further improvements in performance are required. Also, from the viewpoint of fuel economy, it is preferable that soundproofing measures also meet the demand for weight reduction.

[0005] Patent Document 1 below discloses a soundproofing material that aims to improve sound insulation and reduce weight. This soundproofing material has a laminated structure in which an indoor-side sound-absorbing layer and an outdoor-side sound-absorbing layer are provided on both sides of a middle sound-absorbing layer, with thermoplastic resin films interposed between them. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-36675 Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 has a structure in which a middle sound-absorbing layer and a layer (middle layer) made of thermoplastic resin film arranged on both sides of the middle sound-absorbing layer are interposed between the indoor-side sound-absorbing layer and the outdoor-side sound-absorbing layer, which poses the problem of making the soundproofing material itself thick. As such, the thicker the soundproofing material, the higher the sound-insulating performance, but on the other hand, the increased thickness places restrictions on the installation space, so it is necessary to make the material as thin as possible while still improving sound-insulating performance.

[0008] At least one embodiment of the present invention has been made in view of the above circumstances, and specifically, an object of the present invention is to provide a soundproof structure that can improve sound insulation and achieve a thinner structure. [Means for solving the problem]

[0009] The soundproof structure of this embodiment comprises a soundproofing material having an elastic sheet and a support portion that supports the sheet and divides the sheet into partitions, and a clamping member that clamps the soundproofing material, wherein the ten-point mean roughness (RzJIS) of the contact surface between the support portion and the sheet is in the range of 20 μm to 200 μm, and the soundproofing material is clamped by the clamping member and pressurized at a pressure greater than atmospheric pressure. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic exploded perspective view of a soundproof structure according to an embodiment of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing a state before pressure is applied to a soundproof material of a soundproof structure according to an embodiment of the present invention. FIG. [Figure 3] 2 is a schematic cross-sectional view showing a state in which a soundproof material of the soundproof structure according to the present embodiment is pressurized. FIG. [Figure 4]1 is a conceptual diagram of a soundproof structure according to an embodiment of the present invention when packed into a floor mat of a vehicle body. [Figure 5] FIG. 1 is a conceptual diagram for explaining the arrangement of the measurement system (soundproof box and microphone) used to evaluate soundproofing performance in the Examples section. [Figure 6] 1 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-3. [Figure 7] 1 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Example 2-1, Example 2-2, and Comparative Example 2. [Figure 8] 1 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Example 3-1, Example 3-2, and Comparative Example 3. [Figure 9] 4 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Example 4-1, Example 4-2, and Comparative Example 4. [Figure 10] 1 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Example 5-1, Example 5-2, and Comparative Example 5. [Figure 11] 1 is a graph showing the results of measuring the insertion loss of the soundproofing materials of Example 6-1, Example 6-2, Comparative Example 6-1, and Comparative Example 6-2. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown here are merely examples for embodying the technical concept of the present invention and are not intended to limit the present invention. Furthermore, all other embodiments, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included within the scope and spirit of the present invention, as well as within the scope of the claims and their equivalents.

[0012] Furthermore, for the sake of clarity and ease of illustration, the drawings accompanying this specification may be represented schematically and with scales, aspect ratios, shapes, etc., appropriately altered from the actual product, but these are merely examples and do not limit the interpretation of the present invention. In this specification, the term "X to Y" indicating a range means "X or more and Y or less." Unless otherwise specified, operations and measurements of physical properties, etc., are performed at room temperature (20 to 25°C) and a relative humidity of 40 to 50%.

[0013] 1 to 3, a soundproof structure 1 according to this embodiment includes a soundproof material 10 and a clamping member 20 that applies a predetermined pressure to the soundproof material 10 while sandwiching the soundproof material 10. The soundproof structure 1 has a layered structure in which the soundproof material 10 is sandwiched between the clamping member 20 in the thickness direction so that the soundproof material 10 is maintained in a state where it is pressurized with the predetermined pressure (a pressure greater than atmospheric pressure).

[0014] <Soundproofing material> The soundproofing material 10 includes an elastic sheet 11 and a support portion 12 that supports the sheet 11 and divides the sheet 11 into compartments. The soundproofing material 10 can be made of an acoustic metamaterial. An "acoustic metamaterial" is an artificial medium designed to exhibit acoustic properties not normally exhibited by materials found in nature, and can suppress sound transmission by controlling air vibrations caused by sound propagation with the sheet 11. Acoustic metamaterials are useful because they can reduce the thickness of the soundproofing material 10, and therefore the soundproofing structure 1. Examples of acoustic metamaterials that can be used include those disclosed in International Publication No. 2019 / 022245 (Nissan Motor Co., Ltd.).

[0015] Sheet 11 has elasticity and is placed in a state overlapping support portion 12. Because sheet 11 has partitions formed by support portion 12, the parts surrounded by the partitions vibrate, thereby enhancing the soundproofing effect. From the viewpoint of the soundproofing effect of the soundproofing material, the film thickness of sheet 11 is preferably 10 to 1000 μm, and more preferably 100 to 500 μm.

[0016] There are no particular limitations on the constituent material of the sheet 11, and various elastic materials can be used. In this specification, the term "elastic" means that the sheet 11 is made of a material having a Young's modulus value in the range of 0.001 to 70 GPa. The Young's modulus value for resins can be measured according to JIS K7161-1 (2014). The Young's modulus for metals can be measured according to JIS Z2241 (2011). The Young's modulus for rubber can be measured according to JIS Z6251 (2010).

[0017] Examples of materials that can be used for the sheet 11 include rubber materials such as latex rubber, chloroprene rubber (CR), styrene-butadiene rubber (SBR), ethylene-propylene-diene rubber (EPDM), and acrylonitrile-butadiene rubber (NBR). The sheet 11 may also be made of resin, metal, or paper. Furthermore, the sheet 11 may also be made of a material with a shock-absorbing function, such as an air cushion. All of these materials, including rubber, have sufficient elasticity to achieve the effects of the soundproofing material 10 according to this embodiment. Examples of resin materials include polyolefin resins such as polyethylene (e.g., low-density polyethylene, high-density polyethylene, etc.), polypropylene, polyvinyl chloride resin, acrylic resin, methacrylic resin, acrylonitrile-butadiene-styrene resin, vinyl acetate resin, ethylene-vinyl acetate resin, and styrene-butadiene resin. Examples of thermosetting resins that can be used include silicone resin, urethane resin, melamine resin, thermosetting acrylic resin, urea-16 resin, phenolic resin, resorcinol resin, alkylresorcinol resin, epoxy resin, and thermosetting polyester. Resin precursors that produce these resins, such as prepolymers, oligomers, and monomers, may also be used, including urethane resin prepolymer, urea resin prepolymer (initial condensate), phenolic resin prepolymer (initial condensate), diallyl phthalate prepolymer, acrylic oligomer, polyisocyanate, methacrylic ester monomer, and diallyl phthalate monomer. Metal materials include copper and aluminum. The materials constituting the sheet 11 are not limited to those listed above, and other materials may also be used. Rubber materials are preferred as materials for the sheet 11, with latex rubber or EPDM rubber being more preferred. Using these rubber materials as materials for the sheet 11 can favorably achieve the soundproofing effect of the soundproofing material 10 according to this embodiment. Furthermore, these rubber materials are particularly preferable because they are lightweight and contribute significantly to improving fuel economy, especially when considering application to vehicles. Furthermore, from the perspective of cost reduction, polyolefin resins such as polypropylene are also preferable as constituent materials for the sheet 11.

[0018] The support section 12 supports the elastic sheet 11 and divides the sheet 11 into compartments (airtightly divided). There are no particular limitations on the specific configuration of the support section 12, as long as it has a configuration that can exhibit this function. Although Fig. 1 shows multiple compartments, a single compartment is within the scope of the present invention.

[0019] There are no particular limitations on the material that constitutes the support portion 12, and conventionally known thermoplastic or thermosetting resins can be used. Metal materials such as stainless steel mesh or stainless steel wire gauze, or other materials, may also be used as the material that constitutes the support portion 12. All of these materials have physical properties that are suitable for holding the sheet 11 and dividing it into compartments.

[0020] Examples of thermoplastic resins include polyvinyl chloride resin, polyethylene (e.g., low-density polyethylene, high-density polyethylene, etc.), polyolefin resins such as polypropylene, acrylic resin, methacrylic resin, acrylonitrile-butadiene-styrene resin, vinyl acetate resin, ethylene-vinyl acetate resin, and styrene-butadiene resin. Examples of thermosetting resins that can be used include urethane resin, melamine resin, thermosetting acrylic resin, urea resin, phenolic resin, resorcinol resin, alkylresorcinol resin, epoxy resin, and thermosetting polyester. Resin precursors that produce these resins, such as prepolymers, oligomers, and monomers, such as urethane resin prepolymer, urea resin prepolymer (initial condensate), phenolic resin prepolymer (initial condensate), diallyl phthalate prepolymer, acrylic oligomer, polyisocyanate, methacrylic ester monomer, and diallyl phthalate monomer, may also be used. Among these, thermoplastic resins are preferred from the viewpoint of ease of molding, and vinyl chloride resin and polyolefin resin are particularly preferred due to their lightweight, excellent durability, and low cost.

[0021] The support section 12 is preferably a lattice structure having a large number of continuously formed cells. In this case, the support section 12 divides the elastic sheet 11 into a plurality of partitions. Furthermore, more preferably, at least some of the partitions have a regular array structure in which a plurality of partitions having the same outer shape are regularly arranged. This configuration facilitates manufacturing, and the presence of a large number of partitions of the same shape can specifically exhibit soundproofing performance against sound waves in a desired frequency range. In this case, from the viewpoint of further enhancing soundproofing performance, the proportion of the area of ​​the regular array structure to the area of ​​the sheet 11 is preferably 80 to 100%, more preferably 90 to 100%, even more preferably 95 to 100%, even more preferably 98 to 100%, particularly preferably 99 to 100%, and most preferably 100%. At least one lattice structure (support section 12) for one sheet 11 may be divided into a plurality of members. By adopting such a configuration, it is preferable that the soundproofing material 10 according to this embodiment has flexibility as a whole. However, even if the support portion 12 is not divided into multiple members, it is a preferred embodiment that the soundproofing material 10 has flexibility as a whole. This flexibility of the soundproofing material 10 is preferable because it allows the soundproofing material 10 to be positioned in a manner that allows it to follow sound sources of various shapes.

[0022] The outer shape of the compartments in the above-described regular array structure (the cross-sectional shape of the cells in a cross section perpendicular to the thickness direction of the lattice structure) is not limited to a regular rectangle (square) as shown in Figure 1, and may be other shapes. If a large number of cells are arranged by continuously forming regular polygons having the same cross-sectional shape, a regular triangle or a regular hexagon may be used as the cross-sectional shape in addition to a regular rectangle. By using these shapes, a support that is easy to manufacture and exhibits excellent strength can be provided. If the cross section of the lattice structure is to have a pattern in which multiple regular polygons are regularly arranged, then, for example, using Archimedes' plane tessellation, the cross section of the lattice structure can be configured to have the above pattern by any of the following combinations: (4 equilateral triangles, 1 regular hexagon), (3 equilateral triangles, 2 regular quadrilaterals (squares)) x 2 ways, (1 equilateral triangle, 2 regular quadrilaterals (squares), 1 regular hexagon), (2 equilateral triangles, 2 regular hexagons), (1 equilateral triangle, 2 regular dodecagons), (1 regular quadrilateral (square), 1 regular hexagon, 1 regular dodecagon), or (1 regular quadrilateral (square), 2 regular octagons).

[0023] In the soundproofing material 10 according to this embodiment, the surface roughness (ten-point average roughness (RzJIS)) of the contact surface between the support portion 12 and the sheet 11 is 20 μm or more and 200 μm or less. With this configuration, part of the sheet 11 penetrates into the uneven surface shape (hereinafter also referred to as the uneven portion) caused by the surface roughness of the support portion 12, and the sheet 11 comes into close contact with the support portion 12 so as to be able to vibrate, thereby improving the soundproofing effect.

[0024] In contrast, if the ten-point mean roughness of support portion 12 is less than 20 μm, the area of ​​elastic sheet 11 that is pressurized becomes larger, sheet 11 is pressurized more than necessary, and surface vibration of sheet 11 is less likely to occur, reducing sound insulation performance. Also, if the ten-point mean roughness of support portion 12 exceeds 200 μm, the contact area between sheet 11 and support portion 12 is small, so even if pressure is applied by clamping member 20, sheet 11 cannot sufficiently penetrate the uneven portions of support portion 12, reducing the contact area and reducing sound insulation performance.

[0025] The soundproofing material 10 according to this embodiment is clamped by the clamping members 20 and pressurized at a pressure greater than atmospheric pressure. The soundproofing material 10 is preferably pressurized in the range of 5 kPa to 10 kPa in addition to atmospheric pressure. With this configuration, when the sheet 11 is pressed against the support portion 12, a portion of the sheet 11 enters the uneven portion of the support portion 12, and the sheet 11 comes into close contact with the support portion 12 while being able to vibrate. Therefore, in the soundproofing structure 1, the sheet 11 can come into close contact with the support portion 12 without hindering the vibration of the sheet 11, thereby improving the sound insulation performance.

[0026] When the soundproofing material 10 is pressurized with a pressure of 5 kPa or more in addition to atmospheric pressure, the sheet 11 and the support portion 12 can be brought into sufficient close contact and a sufficient contact area can be secured between the sheet 11 and the support portion 12, thereby further improving the soundproofing performance. Furthermore, when the soundproofing material 10 is pressurized with a pressure of 10 kPa or less in addition to atmospheric pressure, the pressure applied to the sheet 11 is not too great and sufficient surface vibration of the sheet 11 can be generated, thereby also further improving the soundproofing performance.

[0027] The soundproofing material 10 according to this embodiment is compressed only at its ends or over its entire surface by the clamping members 20. If the soundproofing material 10 is configured so that only its ends are compressed by the clamping members 20 when it is compressed by the clamping members 20, the soundproofing material 10 will only be clamped at its ends, making installation easier. If the soundproofing material 10 is configured so that its entire surface is compressed when it is compressed by the clamping members 20, the soundproof structure 1 can be manufactured in a pre-pressurized state, allowing installation without using a pressurizing mechanism 30 (described later) or the like, thereby increasing installation flexibility. Note that the ends of the soundproofing material 10 include the outer peripheral edge and a certain range (20 mm) inward from the outer peripheral edge when the soundproofing material 10 is viewed in plan.

[0028] The soundproofing material 10 according to this embodiment is plate-shaped. According to the physical laws governing the surface density and sound insulation properties of a plate, the greater the surface density (weight), the better the sound insulation performance. Therefore, if the density of the material is uniform, the thicker the material, the better the sound insulation performance. However, the thicker the material, the more space must be secured for installation, which may result in restrictions on the installation space. In particular, when the soundproof structure 1 is applied to a vehicle, it is necessary to efficiently arrange the material in a limited space to improve the sound insulation performance. Therefore, from the viewpoint of installation flexibility, it is preferable that the thickness of the soundproofing material 10 be set in the range of 0.5 mm to 6.0 mm.

[0029] If the thickness of the soundproofing material 10 is 0.5 mm or more, the surface rigidity is not too low and sufficient sound insulation performance is obtained. Also, if the thickness of the soundproofing material 10 is 6.0 mm or less, the thickness is not too large, and there are no restrictions on the installation space of the soundproof structure 1, improving the degree of freedom in installation.

[0030] As described above, the soundproofing material 10 according to this embodiment is preferably lightweight. From this viewpoint, the overall surface density of the soundproofing material 10 according to this embodiment is preferably 3.24 kg / m 2 More preferably, it is less than 2.0 kg / m 2 More preferably, it is 1.5 kg / m or less. 2 and particularly preferably 1.0 kg / m 2 The following is the result.

[0031] <Holding member> The clamping members 20 clamp the soundproofing material 10 and apply a pressure greater than atmospheric pressure to the soundproofing material 10. The clamping members 20 are composed of a first clamping member 21 arranged opposite the sheet 11 of the soundproofing material 10, and a second clamping member 22 arranged opposite the support portion 12 of the soundproofing material 10.

[0032] The clamping members 20 need only clamp the soundproofing material 10 under a pressure greater than atmospheric pressure, and there are no particular limitations on their structure or constituent materials. However, in order to achieve effective sound insulation, it is important for the soundproof structure 1 to press the sheet 11 against the support portion 12 when clamping and pressurizing the soundproofing material 10 with the clamping members 20, thereby allowing the sheet 11 to penetrate into the uneven portions of the support portion 12 and achieve close contact. For this reason, the clamping members 20 are preferably made of a material that has elasticity and provides sound-absorbing properties, such as a fiber aggregate such as felt or glass wool, or a porous synthetic resin such as urethane foam. The clamping members 20 may be configured as a pair of members made of the same material, or as a pair of members made of different materials, as long as they have elasticity and sound-absorbing properties.

[0033] Furthermore, it is preferable that at least the first clamping member 21 of the clamping member 20 is made of an elastic material. With this configuration, the soundproofing material 10 allows the first clamping member 21, which is arranged opposite the sheet 11, to appropriately press the sheet 11 against the support portion 12, allowing the sheet 11 to fit into the uneven portions of the support portion 12 and bring the two into close contact with each other.

[0034] The clamping member 20 only needs to be configured to be able to apply a predetermined pressure (a pressure greater than atmospheric pressure, preferably in the range of atmospheric pressure plus 5 kPa to 10 kPa) to the soundproofing material 10, and the thickness, dimensions, etc. can be adjusted appropriately depending on the volume of the space in which the soundproofing structure 1 is to be installed.

[0035] The soundproof structure 1 of this embodiment can be configured to include a pressure mechanism 30 that presses the clamping member 20 toward the soundproof material 10 to maintain a pressurized state so that the sheet 11 and the support portion 12 are in close contact with each other.

[0036] <Pressure mechanism> The pressure mechanism 30 applies pressure to the clamping members 20 of the soundproof structure 1, applying a pressure greater than atmospheric pressure to the soundproofing material 10. The pressure mechanism 30 is configured to press the first clamping member 21 and the second clamping member 22 against the surface of the soundproofing material 10 (the surface extending in a direction intersecting the thickness direction) to maintain a predetermined pressure on the soundproofing material 10. The pressure mechanism 30 may be configured as a component of the soundproof structure 1, or may utilize equipment used at the installation location of the soundproof structure 1. As shown in FIG. 4, when the soundproof structure 1 is applied to a vehicle floor mat, for example, it can be interposed between a steel plate 101 on the vehicle body floor and a sheet material 102 arranged below a floor carpet 103. The sheet material 102 is made of a heavy rubber plate. In this way, the soundproof structure 1 uses the steel plate 101 of the body floor and the sheet material 102 as the pressure mechanism 30, and by placing the sheet material 102 on the upper surface (on the side of the first clamping member 21) of the soundproof structure 1 and clamping it, the soundproof structure 1 is pressurized to a pressure greater than atmospheric pressure by the load from the sheet material 102, and this pressurized state is maintained. Furthermore, if there is no equipment suitable for pressurizing the clamping member 20 at the installation location, the soundproof structure 1 can be equipped with a clamping jig (not shown) that can clamp the soundproof material 10 with the clamping member 20 and maintain a state in which a pressure greater than atmospheric pressure is applied to the soundproof material 10.

[0037] In the soundproof structure 1 according to this embodiment, the sheet 11 and the support portion 12 constituting the soundproofing material 10, or the soundproofing material 10 and the sandwiching member 20, may be bonded with an adhesive, or may be free to be bonded without adhesive or the like. In the soundproof structure 1, bonding the sheet 11 and the support portion 12 increases the adhesion between the sheet 11 and the support portion 12, and the sheet 11 is reliably divided by the partitions formed by the support portion 12, thereby stabilizing the soundproofing performance. However, if the adhesive spreads to the surface of the sheet 11 other than the contact area between the sheet 11 and the support portion 12 (the contact area between the sheet 11 and the support portion 12), the surface rigidity of the sheet 11 may be higher than designed, potentially impeding vibration. Therefore, when using adhesive, it is recommended that the adhesive be applied only to the contact area between the sheet 11 and the support portion 12 and not flow into the non-contact area of ​​the sheet 11 with the support portion 12.

[0038] The soundproof structure 1 according to this embodiment can be suitably used for blocking noises from various sound sources. In particular, the soundproof structure 1 according to this embodiment can be configured to be extremely lightweight. Because the soundproof structure 1 according to this embodiment can be made lightweight, it is preferable that it be mounted on a vehicle for use. In particular, it is most preferably used for soundproofing noises generated from parts that generate loud noises (specific sound sources) such as the engine, transmission, and drivetrain. Examples of application areas include engine head covers, engine body covers, hood insulators, front-dash insulators, air box bulkheads, air intake air cleaners, dust side ducts, and undercovers in the engine compartment. In the cabin, the present invention can be applied to dash insulators, dash panels, floor carpets, spacers, door trim, soundproofing materials in door trim, soundproofing materials in compartments, instrument panels, instrument center boxes, instrument upper boxes, air conditioner housings, roof trim, soundproofing materials in roof trim, sun visors, rear seat air conditioning ducts, cooling ducts for battery cooling systems in battery-powered vehicles, cooling fans, center console trim, soundproofing materials in consoles, parcel trim, parcel panels, seat headrests, front seat backs, and rear seat backs. In the trunk, the present invention can be applied to trunk floor trim, trunk boards, trunk side trim, soundproofing materials in trim, and drafter covers. The present invention can also be applied within the vehicle frame or between panels, such as pillar trim and fenders. The present invention can also be applied to various exterior components, such as under-floor undercovers, fender protectors, tailgates, wheel covers, and aerodynamic covers for suspensions.

[0039] The soundproof structure 1 according to this embodiment is a structure that exhibits sound insulation performance that surpasses the mass law, despite its simple and lightweight configuration consisting of soundproofing material 10 and sandwiching member 20, and is particularly designed with consideration given to the actual mounting structure when mounted on a vehicle. Therefore, by interposing the soundproof structure 1 between surrounding structures or substrates around the installation location (for example, between the steel plate and sheet material of the vehicle body floor when applied to a vehicle floor mat), the soundproofing material 10 can be placed in a state where it is pressurized at a pressure greater than atmospheric pressure, and it can exhibit higher sound insulation performance than conventionally known soundproofing materials.

[0040] There are no particular restrictions on the arrangement of the soundproof structure 1 according to this embodiment relative to a sound source. When the soundproof structure 1 according to this embodiment is arranged relative to a sound source, it is preferable that the sound source be positioned in the direction of the openings of the cells that make up the lattice structure (support portion 12). When arranging in this manner, the sheet 11 may be arranged to be positioned on the sound source side, or the openings of the cells may be arranged to be positioned on the sound source side, but from the viewpoint of better soundproofing performance, the former arrangement is more preferable.

[0041] [Action and effect] As described above, the soundproof structure 1 of this embodiment comprises a soundproofing material 10 having an elastic sheet 11 and a support portion 12 that supports the sheet 11 and divides the sheet 11 into partition portions, and a clamping member 20 that clamps the soundproofing material 10, wherein the ten-point mean roughness (RzJIS) of the contact surface of the support portion 12 with the sheet 11 is in the range of 20 μm or more and 200 μm or less, and the soundproofing material 10 is clamped by the clamping member 20 and pressurized at a pressure greater than atmospheric pressure.

[0042] With this configuration, soundproofing material 10 is pressed at a pressure greater than atmospheric pressure while being sandwiched between sandwiching members 20, and sheet 11 constituting soundproofing material 10 is brought into close contact with support part 12 so as to be able to vibrate, with sheet 11 fitting into the uneven surface shape (uneven portion) caused by the surface roughness of support part 12. Therefore, soundproof structure 1 can improve the sound insulation effect compared to conventionally known soundproofing materials, without making soundproofing material 10 thicker.

[0043] Furthermore, in the soundproofing structure 1 according to this embodiment, the clamping member 20 is preferably composed of a first clamping member 21 arranged opposite the sheet 11 and a second clamping member 22 arranged opposite the support portion 12, and at least the first clamping member 21 may be composed of an elastic member.

[0044] With this configuration, the soundproofing material 10 allows the sheet 11 to be pressed appropriately against the support portion 12, allowing the sheet 11 to fit into the uneven portions of the support portion 12 and bring the two into close contact with each other.

[0045] The soundproof structure 1 according to this embodiment may preferably be configured to include a pressure mechanism 30 that presses the clamping member 20 against the soundproof material 10.

[0046] With this configuration, the soundproofing material 10 is sandwiched between the sandwiching members 20 that are pressurized at a predetermined pressure by the pressurizing mechanism 30, thereby stabilizing the soundproofing performance.

[0047] In the soundproof structure 1 according to this embodiment, the soundproof material 10 may be configured to be pressurized preferably to atmospheric pressure and in the range of 5 kPa to 10 kPa.

[0048] With this configuration, when sheet 11 is pressed against support portion 12, a portion of sheet 11 enters the uneven portion of support portion 12 and comes into close contact with support portion 12 while being able to vibrate. Therefore, in soundproof structure 1, sheet 11 can come into close contact with support portion 12 without hindering the vibration of sheet 11, thereby improving sound insulation performance.

[0049] In the soundproof structure 1 according to this embodiment, the soundproof material 10 may preferably be configured so that only the end portions thereof are pressed by the clamping members 20 .

[0050] With this configuration, when the soundproofing material 10 is pressed by the clamping member 20, the area that is clamped by the soundproofing material 10 is only the end portion, which makes installation easier.

[0051] In the soundproof structure 1 according to this embodiment, the soundproof material 10 may preferably be configured so that the entire surface thereof is pressed by the clamping member 20 .

[0052] With this configuration, when the soundproofing material 10 is pressed by the clamping member 20, the entire surface of the soundproofing material 10 is pressed, so that the soundproofing structure 1 can be manufactured in a pre-pressurized state. Therefore, the soundproofing structure 1 can be installed without using a pressurizing mechanism 30 or the like, increasing the degree of freedom in installation.

[0053] In the soundproof structure 1 according to this embodiment, the soundproof material 10 may preferably have a thickness of 0.5 mm or more and 6.0 mm or less.

[0054] With this configuration, particularly when the soundproof structure 1 is applied to a vehicle, it can be efficiently arranged in a limited installation space, and soundproofing performance can be improved. [Example]

[0055] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to the following examples.

[0056] Examples and comparative examples of the soundproof structure according to the embodiment of the present invention will be described.

[0057] [Outline of soundproofing structure evaluation test equipment and performance test evaluation] The soundproofing performance of the soundproofing structures fabricated in the examples and comparative examples against sound waves of various frequencies was measured. Specifically, a speaker (sound source) 300 was placed inside a soundproofing box (evaluation test device) 200, which consisted of an iron pot with an open top and surrounded by sound-absorbing material, as shown in FIG. 5 . A sample (soundproofing structure) S was placed at the opening of the soundproofing box 200, and the edge of the sample S was clamped and fixed between an open rectangular frame-shaped lid member 210 and a top plate 220. Furthermore, a height-adjusting rubber member 230 was placed on the underside of the sample S as needed, and clay 240 was placed on the underside of the sample S to fill any gaps between the top surface of the sample S and the lid member 210 and prevent sound from entering from outside. Sound was then generated from the speaker (sound source) 300 installed inside the soundproofing box 200, and the insertion loss (unit: dB) was measured relative to a control without the sample S, thereby evaluating the soundproofing performance. A larger insertion loss value at a certain frequency indicates better soundproofing performance against sound waves of that frequency. Unless otherwise specified in the Examples and Comparative Examples below, the soundproof structure was placed so that the sheet was positioned on the side of microphone 400, which serves as a sound collection section and is placed above soundproof box 200, and evaluations were carried out.

[0058] The sound source generating conditions for each example were as follows: Spectrum level: White noise (100~8192Hz) Fmax: 8192Hz ·Δf (frequency resolution): 1Hz Average value: 300 arithmetic average (300 measurements were taken at slightly different times for each measurement, and the arithmetic average was used as the measurement value) ·Overlap: 75%.

[0059] In each example, sample S attached to soundproof box 200 was subjected to a predetermined pressure by compressing with a cover member the portion (protrusion) of a clamping member (first clamping member) disposed on the upper surface side of the soundproof material that protruded from soundproof box 200. The pressure applied to the soundproof material can be determined by adjusting the protrusion of the clamping member and the thickness of rubber member 230 for adjusting the height based on the thickness of the soundproof structure.

[0060] [Sample specifications] The specifications of the samples used in Examples 1 to 4 are as follows: Samples A to C were molded into rectangular plates with each side measuring 200 mm. <Sample A> First clamping element: 10mm thick Takapole (manufactured by Nippon Tokushu Toryo Co., Ltd.; felt + rubber sheet; positioned so that the rubber sheet faces the microphone) Second clamping member: 10mm thick felt Support: PVC (polyvinyl chloride) honeycomb lattice (cell size 4mm) with a ten-point average roughness (RzJIS) of 20μm and a thickness of 5.96mm Sheet: 0.04mm (40μm) thick latex rubber sheet. <Sample B> First clamping element: 10mm thick Takapole (manufactured by Nippon Tokushu Toryo Co., Ltd.; felt + rubber sheet; positioned so that the rubber sheet faces the microphone) Second clamping member: 10mm thick felt Support part: Stainless steel mesh (20 mesh) with a ten-point average roughness (RzJIS) of 60 μm and a thickness of 0.475 mm (475 μm) Sheet: 0.025mm (25μm) thick latex rubber sheet <Sample C> First clamping element: 10mm thick Takapole (manufactured by Nippon Tokushu Toryo Co., Ltd.; felt + rubber sheet; positioned so that the rubber sheet faces the microphone) Second clamping member: 10mm thick felt Support: Stainless steel mesh (opening size 1cm) with a ten-point average roughness (RzJIS) of 200μm and a thickness of 0.975mm (975μm) Sheet: 0.025mm (25μm) thick latex rubber sheet.

[0061] The specifications of the samples used in Examples 1 to 4 are summarized in Table 1 below.

[0062] [Table 1]

[0063] [Example 1] In Example 1, a test was conducted to evaluate the soundproofing performance depending on whether or not the soundproofing material of the soundproof structure was pressurized. Example 1-1 and Comparative Example 1-1 used Sample A, Example 1-2 and Comparative Example 1-2 used Sample B, and Example 1-3 and Comparative Example 1-3 used Sample C. In Examples 1-1 to 1-3, the ends (boundaries) of the soundproofing material were pressurized to 5 kPa by adding atmospheric pressure, while in Comparative Examples 1-1 to 1-3, the pressure was left at atmospheric pressure without pressurization. The insertion loss results obtained from the evaluation of soundproofing performance are shown in FIG.

[0064] As shown in Fig. 6, it was confirmed that Examples 1-1 to 1-3 all exhibited superior soundproofing performance compared to Comparative Examples 1-1 to 1-3, which were configured only with soundproofing material. This test result shows that in a soundproof structure, sandwiching the soundproofing material between sandwiching members and further pressurizing the soundproofing material at a pressure greater than atmospheric pressure (atmospheric pressure + 5 kPa) are important factors in improving soundproofing performance.

[0065] [Example 2] In Example 2, a test was conducted to evaluate soundproofing performance according to the pressure applied to the soundproofing material of the soundproof structure. Sample B was used in Examples 2-1, 2-2, and Comparative Example 2. In Example 2-1, the edge (boundary) of the soundproofing material was pressurized to 5 kPa in addition to atmospheric pressure, in Example 2-2 the edge (boundary) of the soundproofing material was pressurized to 10 kPa in addition to atmospheric pressure, and in Comparative Example 2 the pressure was left at atmospheric pressure without any pressure applied. The insertion loss results obtained from the evaluation of soundproofing performance are shown in FIG. 7.

[0066] As shown in Figure 7, it was confirmed that Examples 2-1 and 2-2 both exhibited excellent soundproofing performance compared to Comparative Example 2, which was not pressurized. Furthermore, when comparing Examples 2-1 and 2-2, although a partial reversal phenomenon was observed in the high frequency band above about 1600 Hz, it was confirmed that soundproofing performance was further improved by increasing the pressure. This test result shows that in a soundproof structure, sandwiching the soundproofing material between clamping members and further pressurizing the soundproofing material by setting a pressure greater than atmospheric pressure in the range of 5 kPa to 10 kPa above atmospheric pressure is effective in improving soundproofing performance.

[0067] [Example 3] In Example 3, a test was conducted to evaluate soundproofing performance according to differences in the pressure region of the soundproofing material of the soundproof structure. Sample B was used in Examples 3-1, 3-2, and Comparative Example 3. In Example 3-1, the edge (boundary) of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, in Example 3-2, a lattice-shaped member was interposed between the cover member and the entire surface of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, and in Comparative Example 3, atmospheric pressure was maintained without pressurization. The insertion loss results obtained by evaluating soundproofing performance are shown in FIG. 8.

[0068] As shown in Fig. 8, it was confirmed that Examples 3-1 and 3-2 both exhibited excellent soundproofing performance compared to Comparative Example 3, which was not pressurized. This test result shows that in a soundproof structure, sandwiching a soundproof material between clamping members and further pressurizing the edges and entire surface of the soundproof material at a pressure greater than atmospheric pressure (5 kPa above atmospheric pressure) is effective in improving soundproofing performance.

[0069] [Example 4] In Example 4, a test was conducted to evaluate the soundproofing performance according to the difference in the pressure region of the soundproofing material of the soundproof structure. Sample C was used in Examples 4-1, 4-2, and Comparative Example 4. In Example 4-1, the edge (boundary) of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, in Example 4-2, a lattice-shaped member was interposed between the cover member and the entire surface of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, and in Comparative Example 4, atmospheric pressure was maintained without pressurization. The insertion loss results obtained by evaluating the soundproofing performance are shown in FIG. 9.

[0070] As shown in Fig. 9, it was confirmed that Examples 4-1 and 4-2 both exhibited excellent soundproofing performance compared to Comparative Example 4, which was not pressurized. This test result shows that in a soundproof structure, sandwiching a soundproof material between clamping members and further pressurizing the edges and entire surface of the soundproof material at a pressure greater than atmospheric pressure (5 kPa above atmospheric pressure) is effective in improving soundproofing performance.

[0071] [Example 5] In Example 5, a test was conducted to evaluate the soundproofing performance according to the difference in the pressure region of the soundproofing material of the soundproof structure. Sample A was used in Examples 5-1, 5-2, and Comparative Example 5. In Example 5-1, the edge (boundary) of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, while in Example 5-2, a lattice-shaped member was interposed between the cover member and the entire surface of the soundproofing material was pressurized to 5 kPa by adding atmospheric pressure, and in Comparative Example 5, atmospheric pressure was maintained without pressurization. The insertion loss results obtained by evaluating the soundproofing performance are shown in FIG. 10.

[0072] As shown in Fig. 10, it was confirmed that Examples 5-1 and 5-2 both exhibited excellent soundproofing performance compared to Comparative Example 5, which was not pressurized. This test result shows that in a soundproof structure, sandwiching a soundproof material between clamping members and further pressurizing the edges and entire surface of the soundproof material at a pressure greater than atmospheric pressure (5 kPa above atmospheric pressure) is effective in improving soundproofing performance.

[0073] [Example 6] In Example 6, a test was conducted to evaluate the soundproofing performance according to the thickness of the soundproofing material of the soundproof structure. Example 6-1 and Comparative Example 6-1 used Sample B, and Example 6-2 and Comparative Example 6-2 used Sample A. In Example 6-1, the soundproofing material of Sample B had a thickness of 0.5 mm, and in Example 6-2, the soundproofing material of Sample A had a thickness of 6.0 mm. In Comparative Example 6-1, Example 6-1 was left at atmospheric pressure without pressurization, and in Comparative Example 6-2, Example 6-2 was left at atmospheric pressure without pressurization. The insertion loss results obtained from the evaluation of soundproofing performance are shown in FIG. 11.

[0074] 11, the thickness of the soundproofing material in Example 6-1 was 0.5 mm, and the thickness of the soundproofing material in Example 6-2 was 6.0 mm, that is, the thickness of the soundproofing material was set in the range of 0.5 mm to 6.0 mm, and it was confirmed that each Example exhibited excellent soundproofing performance compared to Comparative Examples 6-1 and 6-2, which were not pressurized. This test result shows that in a soundproof structure, setting the thickness of the soundproofing material in the range of 0.5 mm to 6.0 mm and clamping the soundproofing material with a clamping member to pressurize it at a pressure greater than atmospheric pressure (5 kPa above atmospheric pressure) is effective in improving soundproofing performance. [Explanation of symbols]

[0075] 1 soundproof structure, 10 soundproofing materials, 11 seats, 12 support part; 20 clamping member; 21 first clamping member, 22 second clamping member, 30 pressure mechanism, 101 Body floor steel plate, 102 sheet material, 103 Floor carpet, 200 soundproof boxes, 210 lid member, 220 Top Plate 230 rubber plates, 240 clay, 300 speakers (sound source) 400 microphones, S sample.

Claims

1. a soundproofing material including an elastic sheet and a support portion that supports the sheet and divides the sheet into partition portions; a clamping member that clamps the soundproofing material, The ten-point average roughness (RzJIS) of the contact surface of the support portion with the sheet is in the range of 20 μm or more and 200 μm or less, The soundproof structure, wherein the soundproof material is clamped by the clamping members and pressurized at a pressure greater than atmospheric pressure.

2. the clamping member is composed of a first clamping member arranged opposite the sheet and a second clamping member arranged opposite the support portion, 2. The soundproof structure according to claim 1, wherein at least the first clamping member is made of an elastic material.

3. The soundproof structure according to claim 1 or 2, further comprising a pressure mechanism for pressing the clamping member against the soundproof material.

4. 4. The soundproof structure according to claim 1, wherein the soundproof material is pressurized in a range of 5 kPa to 10 kPa in addition to atmospheric pressure.

5. 5. The soundproof structure according to claim 1, wherein only the ends of the soundproof material are pressed by the clamping member.

6. 5. The soundproof structure according to claim 1, wherein the soundproof material is pressed over the entire surface by the clamping member.

7. The soundproof structure according to any one of claims 1 to 6, wherein the soundproof material has a thickness of 0.5 mm or more and 6.0 mm or less.

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