Sound-absorbing structure, automotive interior parts and automobiles

Abstract

To provide means that enables high sound absorption performance to be achieved in a wide frequency band including a frequency range of 300 Hz or under.SOLUTION: A sound absorption structure includes: a grid plate made of resin or metal; a porous body sheet stacked on the grid plate and fixed to the grid plate in a portion opposed to at least some of lattice points of the grid plate; and a base material opposed to the grid plate with the porous body sheet therebetween.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sound absorbing structure, an interior part for an automobile, and an automobile. [Background technology]

[0002] There are many sound sources within an automobile. To address the demand for quietness from both inside and outside the vehicle, automobiles are equipped with various soundproofing and sound-absorbing measures. In particular, specialized soundproofing covers with excellent sound absorption and blocking capabilities are used for loud noise-generating components (inherent sound sources) such as the engine, transmission, and drivetrain. Furthermore, since reducing interior noise is directly linked to the value (luxury) of a vehicle, there is a high demand for low-noise components in automobiles. For example, even within an automobile's cabin, cavity resonance can be induced by engine vibration, intake and exhaust noise, and road irritation, resulting in muffled sounds and road noise. Therefore, measures to reduce such noise are essential. While various sound-absorbing components have been used in automobile interiors, such as roof trim, further performance improvements are required.

[0003] Various configurations have been proposed for such sound absorbing parts (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-316364 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the inventors have found through their research that even if the technology described in Patent Document 1 etc. is used, it is not possible to achieve sufficient sound absorption performance in the frequency range of 300 Hz or less. Therefore, an object of the present invention is to provide a means that makes it possible to achieve high sound absorption performance in a wide frequency range, including the frequency range of 300 Hz or less. [Means for solving the problem]

[0006] The sound-absorbing structure of the present invention comprises a lattice plate made of resin or metal, a porous body sheet laminated on the lattice plate and fixed to the lattice plate at a position facing at least some of the lattice points of the lattice plate, and a base material facing the lattice plate with the porous body sheet in between. [Effects of the Invention]

[0007] According to the present invention, when sound is incident on a porous sheet, the portions of the porous sheet that are not fixed to the lattice plate are displaced in the direction of the sound incidence, generating vibrations that cancel out the low-frequency components of the sound. As a result, sound absorption performance can be improved, particularly in the low-frequency band below 300 Hz. Furthermore, the vibrations of the porous sheet and the substrate influence each other, making it possible to further improve sound absorption performance compared to when no substrate is provided. Therefore, it is possible to demonstrate high sound absorption performance over a wide frequency band, including the frequency range below 300 Hz. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating an outline of a sound absorbing structure according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of a cross-sectional configuration of the sound absorbing structure shown in FIG. [Figure 3] 1. FIG. 4 is a schematic diagram showing another example of the cross-sectional configuration of the sound absorbing structure shown in FIG. [Figure 4] 1. FIG. 4 is a schematic diagram showing another example of the cross-sectional configuration of the sound absorbing structure shown in FIG. [Figure 5] 1. FIG. 4 is a schematic diagram showing another example of the cross-sectional configuration of the sound absorbing structure shown in FIG. [Figure 6] 2 is a diagram for explaining vibrations that occur when sound is incident on the sound absorbing structure shown in FIG. 1. FIG. [Figure 7] FIG. 1 is a diagram schematically illustrating the configuration of an apparatus used to measure sound absorption coefficient. [Figure 8] 1 is a graph showing the results of measuring the sound absorption coefficient of the sound absorbing structures of Examples 1 and 2 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the technical scope of the present invention is not limited to the following embodiments. Note that the dimensional ratios in the drawings are exaggerated for the sake of explanation and may differ from the actual ratios. In this specification, the range "X to Y" means "X or more and Y or less." Furthermore, unless otherwise specified, operations and measurements of physical properties, etc. are performed under conditions of room temperature (20 to 25°C) and relative humidity of 40 to 50%.

[0010] <Embodiment> [Sound-absorbing structure configuration] FIG. 1 is a perspective view schematically illustrating a sound-absorbing structure 1 according to one embodiment of the present invention, and FIG. 2 shows an example of the cross-sectional configuration of the sound-absorbing structure 1. The sound-absorbing structure 1 has a laminated structure having a substrate 30, a porous body sheet 10, and a lattice plate 20, in this order. In the following description, the lamination direction of the substrate 30, the porous body sheet 10, and the lattice plate 20 is sometimes referred to as the Z direction, and the directions intersecting this direction are sometimes referred to as the X direction and the Y direction. FIG. 2 shows an example of the XZ cross-sectional configuration of the sound-absorbing structure 1. In this specification, "sound absorption" means reducing reflected sound or absorbing sound (acoustics).

[0011] It is preferable that the sound absorbing structure 1 is lightweight. From this viewpoint, the density of the sound absorbing structure 1 as a whole is preferably 1 g / cm 3 or less, more preferably 0.5 g / cm 3 More preferably, it is 0.3 g / cm or less. 3 or less, and particularly preferably 0.2 g / cm 3The sound absorbing structure 1 is preferably thin. From this viewpoint, the overall thickness of the sound absorbing structure 1 is preferably 50 mm or less, more preferably 30 mm or less, and even more preferably 20 mm or less.

[0012] (Porous sheet) The porous body sheet 10 is disposed between the substrate 30 and the lattice plate 20. The porous body sheet 10 laminated on the lattice plate 20 has, for example, a rectangular planar shape (XY plane). The porous body sheet 10 has a plurality of communicating holes. There are no particular restrictions on the material constituting the porous body sheet 10, and known materials can be used. Examples include porous body sheets made of fibrous materials, resin foams, metals, ceramics, glass, etc. Among these, resin foams are preferred because of their light weight.

[0013] The fibrous body is not particularly limited as long as it is an aggregate of fibers having voids on the surface and inside thereof, and either a woven fabric or a nonwoven fabric such as felt can be used. Furthermore, the fibrous body may be made of organic fibers such as resin fibers, or inorganic fibers such as glass fibers.

[0014] Examples of resin foams include polyolefin foams such as polyurethane foam (hereinafter also referred to as urethane foam), polyethylene foam, and polypropylene foam; polystyrene foam; polyamide foam; polyester foams such as polyethylene terephthalate (PET) foam and polybutylene terephthalate (PBT); (meth)acrylic foam; phenolic foam; polyvinyl chloride foam; polyimide foam; silicone resin foam; urea resin foam; melamine resin foam; ethylene propylene diene rubber (EPDM) foam; styrene butadiene rubber (SBR) foam; nitrile butadiene rubber (NBR) foam; ethylene-vinyl acetate copolymer (EVA) foam; ethylene-acrylic acid copolymer foam; and ethylene-ethyl acrylate copolymer (EEA) foam. Among these, polyurethane foams are preferred from the viewpoint of sound absorption performance. These foams may be soft, semi-rigid, or rigid.

[0015] The thickness of the porous sheet 10 is not particularly limited, but from the viewpoint of sound absorption effect, it is preferably 1 mm to 100 mm, more preferably 5 mm to 50 mm. The density of the porous sheet 10 is also not particularly limited, but it is preferably 3 kg / m 3 ~150kg / m 3 This is preferable from the viewpoint of weight reduction.

[0016] (lattice plate) The lattice plate 20 supporting the porous sheet 10 has, for example, a rectangular planar shape (XY plane) that is approximately the same size as the porous sheet 10. The lattice plate 20 has, for example, a plurality of lattice points 21 and a plurality of openings 22.

[0017] The openings 22 are arranged in a matrix along the X and Y directions and are holes that penetrate the lattice plate 20 in the Z direction. The openings 22 have, for example, a square planar shape. The planar shape of the openings 22 may also be other shapes such as a rectangle, a hexagon, or a triangle.

[0018] There are also no particular limitations on the size of opening 22. For example, when opening 22 has a square planar shape, the length of one side is, for example, 1 mm to 50 mm, preferably 2 mm to 40 mm, and more preferably 3 mm to 39 mm. This can improve the sound absorption characteristics in the low frequency range, particularly in the frequency range of 300 Hz or less.

[0019] The area of each opening 22 (opening area) is not particularly limited, but from the viewpoint of obtaining high sound absorption characteristics, it is preferably 10 mm 2 ~1500mm 2 The opening area is 10 mm 2 If the opening area is 1500mm or more, the sound absorption coefficient of 200Hz or less can be improved. 2 If it is equal to or less than this, the sound absorption coefficient in the frequency range of 200 to 300 Hz can be improved.

[0020] The lattice points 21 are the intersections of plate portions extending in the X direction and plate portions extending in the Y direction, and are present, for example, at the centers of the four openings 22. Fixing members 21a for fixing the porous material sheet 10 are provided at at least some of the lattice points 21 of the lattice plate 20 (FIG. 2). In other words, the porous material sheet 10 is fixed to the lattice plate 20 at portions facing at least some of the lattice points 21 of the lattice plate 20, and the remaining portions are capable of vibrating in the direction of incident sound. As will be described in detail later, this generates membrane vibration (or plate vibration) in the porous material sheet 10, making it possible to improve sound absorption performance in the low frequency range.

[0021] The fixing members 21a are provided on one surface of the lattice plate 20 (the XY plane on the porous body sheet 10 side). The fixing members 21a may be provided over the entire area of the lattice points 21, or may be provided on some of the lattice points 21. The fixing members 21a may be provided at all of the lattice points 21 of the lattice plate 20, or may be provided on some of the lattice points 21. The fixing members 21a may be provided on parts of the lattice plate 20 other than the lattice points 21. The fixing members 21a are made of, for example, double-sided tape or adhesive. The fixing members 21a may also be fasteners such as screws or bolts.

[0022] To obtain the effects of the present invention more significantly, it is preferable to arrange the fixing members 21a as follows, for example: When the fixing members 21a are arranged in a strip shape, the distance between adjacent fixing members 21a is, for example, 200 mm or less, preferably 100 mm or less; When the fixing members 21a are arranged in a grid shape, the distance between adjacent rows and columns of fixing members 21a is, for example, 200 mm or less, preferably 100 mm or less; When the fixing members 21a are arranged in a dotted shape, the distance between adjacent fixing members 21a is, for example, 200 mm or less, preferably 100 mm or less.

[0023] The lattice plate 20 is made of resin or metal, which makes it easier to adjust the Young's modulus of the lattice plate 20 to a desired value, and makes it possible to improve the sound absorbing characteristics of the sound absorbing structure 1.

[0024] The resin material constituting the grid plate 20 is not particularly limited, but conventionally known thermoplastic resins or thermosetting resins can be used.

[0025] Examples of thermoplastic resins include polyethylene (e.g., low-density polyethylene, high-density polyethylene, etc.), polyolefin resins such as polypropylene, polyvinyl chloride resins, acrylic resins, methacrylic resins, acrylonitrile-butadiene-styrene resins, vinyl acetate resins, ethylene-vinyl acetate resins, and styrene-butadiene resins. Examples of thermosetting resins that can be used include urethane resins, melamine resins, thermosetting acrylic resins, urea resins, phenolic resins, resorcinol resins, alkylresorcinol resins, epoxy resins, and thermosetting polyesters. Resin precursors that produce these resins, such as prepolymers, oligomers, and monomers, may also be used, including urethane resin prepolymers, urea resin prepolymers (initial condensates), phenolic resin prepolymers (initial condensates), diallyl phthalate prepolymers, acrylic oligomers, polyisocyanates, methacrylic ester monomers, and diallyl phthalate monomers. Among these, thermoplastic resins are preferred from the viewpoint of ease of molding, and polyolefin resins are particularly preferred due to their lightweight, excellent durability, and low cost.

[0026] Examples of the metal material include copper, aluminum, titanium, magnesium, tungsten, iron, chromium, and alloys thereof. Stainless steel (SUS) may also be used as the metal material.

[0027] The thickness of the lattice plate 20 is not particularly limited, but is, for example, 0.1 mm to 10 mm, and preferably 0.5 mm to 5 mm. If it is 0.1 mm or more, the effects of the present invention can be more easily obtained. Also, if it is 10 mm or less, it is preferable from the viewpoint of weight reduction.

[0028] The sound-absorbing structure 1 may have multiple lattice plates 20. For example, by shifting the positions of the multiple lattice plates 20, it is possible to adjust the size of the overlapping area between the openings 22 of the lattice plates 20. This makes it possible to adjust the sound-absorbing characteristics of the sound-absorbing structure 1.

[0029] (base material) The substrate 30 faces the lattice plate 20 with the porous body sheet 10 therebetween. The substrate 30 has, for example, a rectangular planar shape (XY plane) that is approximately the same size as the lattice plate 20 and the porous body sheet 10. The size of the XY plane of the substrate 30 may be larger than the size of the XY plane of the lattice plate 20 and the porous body sheet 10. The substrate 30 may be, for example, a part of an automotive interior part such as a roof trim. As will be described in detail later, providing such a substrate 30 in the sound-absorbing structure 1 can further improve sound absorption performance.

[0030] The substrate 30 is made of, for example, a fibrous material such as fabric. Examples of the fibrous material include nonwoven fabric, woven fabric, and felt. The thickness of the substrate 30 is, for example, 0.1 mm to 20 mm, preferably 0.5 mm to 10 mm, and more preferably 1 mm to 7 mm.

[0031] The entire surface of the porous body sheet 10 facing the substrate 30 (XY plane) may be in contact with the substrate 30 (FIG. 2), or only a portion of the surface facing the substrate 30 may be in contact with the substrate 30. By providing the substrate 30 so that it is in contact with the porous body sheet 10, the sound absorbing structure 1 can be made thinner.

[0032] 3, 4, and 5 show other examples of the cross-sectional (XZ cross-section) configuration of the sound-absorbing structure 1. For example, an air layer 40 may be provided at least partially between the porous body sheet 10 and the substrate 30 (FIG. 3). In this case, for example, a spacer 41 is disposed between the porous body sheet 10 and the substrate 30 together with the air layer 40. In other words, the spacer 41 forms the air layer 40 between the porous body sheet 10 and the substrate 30. The thickness (size in the Z direction) of the air layer 40 is, for example, 0.1 mm to 50 mm, preferably 0.5 mm to 20 mm, and more preferably 1 mm to 15 mm. The spacer 41 is made of, for example, a resin material such as an acrylic resin or a metal material. One frame-shaped spacer 41 may be provided between the porous body sheet 10 and the substrate 30, or multiple spacers 41 may be provided at a distance from each other. By providing an air layer 40 between the porous sheet 10 and the substrate 30, the air layer 40 as well as the substrate 30 are coupled to the membrane vibration of the porous sheet 10, making it possible to obtain higher sound absorption performance.

[0033] The sound-absorbing structure 1 may be provided with an adhesive member 50 that bonds the porous body sheet 10 and the substrate 30 (FIG. 4). The adhesive member 50 is made of, for example, double-sided tape or adhesive, and is provided between the porous body sheet 10 and the substrate 30. By providing such an adhesive member 50, it is possible to prevent misalignment between the porous body sheet 10 and the substrate 30. The adhesive member 50 may be provided in at least a portion of the area where the porous body sheet 10 and the substrate 30 contact each other.

[0034] At least one of the lattice plate 20, the porous body sheet 10, and the substrate 30 may be supported by a support member 60 (FIG. 5). By using the support member 60 to support the lattice plate 20, the porous body sheet 10, or the substrate 30, it is possible to prevent the sound-absorbing structure 1 from falling off due to its own weight, regardless of the installation direction. Furthermore, for example, by supporting the substrate 30, the lattice plate 20, and the porous body sheet 10 individually, it is possible to provide an air layer 40 between the porous body sheet 10 and the substrate 30 without using a spacer (for example, spacer 41 in FIG. 4).

[0035] [Effects of sound-absorbing structures] Next, the effects of the sound absorbing structure 1 will be described.

[0036] For example, when sound enters a porous sheet, the sound waves are affected by friction with the surrounding walls and viscous resistance within the pores, and some of the sound energy is consumed as heat, resulting in sound absorption. However, the sound absorption performance of the porous sheet produced in this way is weak in the low-frequency range, making it difficult to obtain sufficient sound absorption properties with the porous sheet in the low-frequency range below 300 Hz, such as vibrations caused by cavity resonance within the vehicle body. For example, to increase the sound absorption coefficient in the low-frequency range, it becomes necessary to increase the thickness of the porous sheet.

[0037] Furthermore, as the density of the constituent materials increases, the soundproofing performance improves, so in order to improve the soundproofing performance, it becomes necessary to increase the density of the soundproofing material, that is, to increase its weight.

[0038] In contrast, in the sound-absorbing structure 1 of this embodiment, the porous sheet 10 is fixed to the lattice plate 20 at a location facing at least some of the lattice points 21 of the lattice plate 20. This allows the structure to have excellent sound-absorbing performance in the frequency range of 300 Hz or less, even though it is lightweight and thin.

[0039] FIG. 6 shows a schematic diagram of vibrations of the sound-absorbing structure 1 when sound S is incident. In the sound-absorbing structure 1, when sound S is incident on the porous body sheet 10 from the substrate 30 side, the portion of the porous body sheet 10 that is not fixed to the lattice plate 20 is displaced in the direction of the incident sound S, generating membrane vibrations that cancel out the low-frequency components of the sound. This attenuates the low-frequency components of the sound, thereby improving the sound-absorbing performance of the sound-absorbing structure 1 in the low-frequency range. The sound-absorbing structure 1 exhibits high sound-absorbing performance, particularly in the frequency range of 300 Hz or less (e.g., 50 Hz to 300 Hz or 100 Hz to 300 Hz). The same sound-absorbing effect can be achieved even when sound is incident on the porous body sheet 10 from the lattice plate 20 side. In this way, by generating membrane vibrations in the porous body sheet 10, the sound-absorbing structure 1 can improve the sound-absorbing performance in the low-frequency range without increasing the thickness or density.

[0040] Furthermore, since the sound-absorbing structure 1 is provided with the base material 30, the membrane vibration of the porous body sheet 10 and the vibration of the base material 30 (or the base material 30 and the air layer 40) affect each other. That is, the membrane vibration of the porous body sheet 10 is coupled with the base material 30 and the air layer 40. This makes it possible to obtain higher sound-absorbing performance than a sound-absorbing structure that does not have the base material 30. Therefore, the sound-absorbing structure 1 can exhibit high sound-absorbing performance over a wide frequency range, including a frequency range of 300 Hz or less.

[0041] <Application example> The sound-absorbing structure according to this embodiment can be suitably used for absorbing noise from various sound sources. In particular, the sound-absorbing structure according to this embodiment can be configured to be extremely lightweight. Because of this lightweight capability, the sound-absorbing structure according to this embodiment is preferably mounted on a vehicle for use. Examples of application areas include dash insulators, dash panels, floor carpets, spacers, door trim, sound-absorbing structures within door trim, sound-absorbing structures within compartments, instrument panels, instrument center boxes, instrument upper boxes, air conditioner housings, roof trim, sound-absorbing structures within roof trim, sun visors, rear seat air conditioning ducts, cooling ducts for battery cooling systems in battery-powered vehicles, cooling fans, center console trim, sound-absorbing structures within consoles, parcel trim, parcel panels, seat headrests, front seat backs, and rear seat backs. Furthermore, in the trunk, the sound-absorbing structure can be applied to trunk floor trim, trunk boards, trunk side trims, sound-absorbing structures within trim, and drafter covers. It can also be applied inside the vehicle frame or between panels, for example, to pillar trim and fenders. In particular, it is preferable to use it in automotive interior parts because it has excellent sound absorption performance in the frequency range of 300 Hz or less, is lightweight, and allows for a thin overall thickness. [Example]

[0042] The present invention will be described in more detail below with reference to examples, although the technical scope of the present invention is not limited to the following examples.

[0043] <<Sound absorption coefficient measurement>> Figure 7 shows a schematic diagram of the sound absorption coefficient measurement device used. The sound absorption coefficient was measured approximately in accordance with JIS A 1405-2 (Measurement of sound absorption coefficient and impedance using an acoustic tube - Part 2: Transfer function method). The sound absorption coefficient was measured by placing an impedance tube 200 and a sound-absorbing sample 100 on a desk 400. A speaker 201 (Fostex, FE103En) and two microphones 202 (Brüel & Kjær, 5957) were attached to the impedance tube 200. The sample 100 was held in place by a spacer 301. A spacer 302 was placed behind the sample 100, forming a 10 mm air gap. A 5 mm gap 303 was left between the spacer 302 and a reflector 304. In addition to the above, the measurements were carried out using a measuring instrument front end (Siemens KK, LMS SCADAS III), measurement software (Siemens KK, LMS TEST.Lab 14A), a measurement computer (Dell Corporation, PRECISION M4800), and a speaker amplifier (Bose Japan KK, 1702).

[0044] [Example 1] The porous sheet was a 10 mm thick urethane foam (density: approximately 32.1 kg / m 3 , Flow resistance: approx. 36000Ns / m 4 ) was cut to a size of 90 mm x 90 mm.

[0045] A 1.0 mm thick polypropylene (PP) plate (manufactured by Acrylic Eye Co., Ltd., density: 0.9 g / cm 3 ) was cut to a size of 90 mm × 90 mm. This PP plate was cut so that the openings were squares with sides of 15 mm and the spacing between the openings was 7 mm to prepare a grid plate.

[0046] A substrate was prepared by cutting a 5.0 mm thick miscellaneous felt into a size of 150 mm x 150 mm.

[0047] A porous body sheet and a lattice plate were laminated in this order on the substrate, and the porous body sheet and the lattice plate were fixed with double-sided tape provided in a lattice pattern on the lattice plate. The porous body sheet and the substrate were not fixed. This produced the sound-absorbing structure of Example 1.

[0048] [Example 2] A spacer having a thickness of 10.0 mm was provided between the porous sheet and the substrate to form an air layer having a thickness of 10.0 mm. Except for this, the sound-absorbing structure of Example 2 was produced in the same manner as in Example 1.

[0049] [Comparative Example 1] Except for not providing a base material, the sound absorbing structure of Comparative Example 1 was produced in the same manner as in Example 1. That is, the sound absorbing structure of Comparative Example 1 only includes a porous sheet and a lattice plate.

[0050] Comparative Example 2 Except for not providing the porous sheet and the lattice plate, the sound absorbing structure of Comparative Example 2 was produced in the same manner as in Example 1. That is, the sound absorbing structure of Comparative Example 2 has only a base material.

[0051] The specifications of the above-mentioned Examples and Comparative Examples are shown in the following Table 1. For the Reference, the sound absorption coefficient was measured without providing anything at the position of Sample 100 (FIG. 7).

[0052] [Table 1]

[0053] FIG. 8 shows the results of the sound absorption coefficients measured using the sound absorbing structures of Examples 1 and 2 and Comparative Examples 1 and 2. As shown in FIG. 8, the sound absorbing structures of Examples 1 and 2 were found to exhibit higher sound absorption coefficients across a wide frequency range, including the low frequency range of 300 Hz or less, compared to the sound absorbing structures of Comparative Examples 1 and 2. Compared to Comparative Example 1, Examples 1 and 2 exhibit improved sound absorption coefficients in the frequency range of 800 Hz or more. Compared to Comparative Example 2, Examples 1 and 2 exhibit improved sound absorption coefficients across all frequency ranges, but the sound absorption coefficient is significantly improved in the low frequency range of 600 Hz or less, especially 300 Hz or less. In the frequency range of 700 Hz or more, the sound absorbing structure of Example 2 exhibits a higher sound absorption coefficient than Example 1.

[0054] As described above, it was confirmed that high sound absorption performance was obtained over a wide frequency range, including the low frequency range of 300 Hz or less, in Examples 1 and 2. Although not shown in Fig. 8, it was confirmed that the sound absorption performance of the sound absorbing structures consisting of only the porous body sheet and only the lattice plate was lower than that of Comparative Example 1.

[0055] The sound-absorbing structure of the present invention has been described above using embodiments and examples. However, those skilled in the art can appropriately add, modify, and omit aspects of the present invention within the scope of the technical concept. For example, the configurations, shapes, sizes, etc. of the components of the sound-absorbing structure described in the above embodiments and examples are merely examples, and other configurations, shapes, sizes, etc. may be used. [Explanation of symbols]

[0056] 1. Sound-absorbing structure 10 Porous sheet 20 lattice plate 21 grid points 21a Adhesive position (fixed position) 22 Opening 30 Base material 40 Air Layer 41 Spacer 50 Adhesive material 60 Support member.

Claims

1. a lattice plate made of resin or metal; Fixing members provided at at least some of the lattice points on one surface of the lattice plate; A porous sheet that is laminated on the lattice plate and fixed to the lattice plate by the fixing member, and whose surface facing the lattice plate forms a flat surface when no sound is incident; a substrate facing the lattice plate with the porous sheet interposed therebetween; A sound-absorbing structure.

2. The sound absorbing structure according to claim 1 , wherein at least a portion of the porous sheet is in contact with the substrate.

3. The sound absorbing structure according to claim 2 , further comprising an adhesive member that bonds the porous sheet and the base material together.

4. The sound absorbing structure according to claim 1 , wherein an air layer is present at least partially between the porous sheet and the substrate.

5. The sound absorbing structure according to claim 4 , further comprising a spacer between the porous sheet and the base material, together with the air layer.

6. The sound-absorbing structure according to any one of claims 1 to 5, wherein at least one of the lattice plate, the porous body sheet, and the base material is supported by a support member.

7. The sound absorbing structure according to any one of claims 1 to 6, wherein the openings of the lattice plate have a rectangular planar shape.

8. An interior part for an automobile, comprising the sound absorbing structure according to any one of claims 1 to 7.

9. An automobile having the sound-absorbing structure according to any one of claims 1 to 7 or the interior part according to claim 8.

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