Sound insulation structure

Abstract

To provide a sound insulation structure that has sufficient sound insulation properties, can be easily and stably placed on a thin and light mounting surface in a curved shape and an irregular shape, and has a surrounding section for at least partially covering a space a sound generation source or a space isolated from the sound generation source.SOLUTION: A sound insulation structure 10 has a surrounding section 11 for at least partially covering a sound generation source 12 or a space to be isolated, and a surface that is at least one portion of the surrounding section 11 and faces inside has a sound insulation mechanism 1. The sound insulation mechanism 1 has a membrane section 2 having elasticity, a support wall section 3 that is erected in the membrane section 2 and has elasticity, and weight sections 4 erected in the membrane section 2. The membrane section 2 is divided into multiple compartments 5 by the support wall section 3, and the weight sections 4 are positioned each within the compartment 5. The height H1 of the support wall section 3 is larger than the height H2 of the weight sections 4. Each of the weight sections 4 constitutes a spring mass resonator having a spring section 4a having elasticity, and a mass section 4b having larger mass than that of the spring section 4a.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sound insulation structure.

Background Art

[0002] In recent years, in the interiors of buildings such as apartment houses, office buildings, and hotels, outdoor noise from automobiles, railways, airplanes, ships, etc. outside the building, equipment noise generated outside the room inside the building, and human voices are blocked, and tranquility suitable for the use of the room is required. Also, inside vehicles such as automobiles, railways, airplanes, and ships, it is desired to reduce noise by blocking wind noise and engine noise to provide a quiet and comfortable space for passengers. Therefore, means for blocking the propagation of noise and vibration from the outside to the inside of buildings and vehicles, and also for blocking the propagation of noise and vibration from the outside to the inside within buildings and vehicles, that is, a sound insulation structure, is required. In recent years, in buildings, a lightweight sound insulation structure has been required due to high-rise construction, etc., and also in vehicles, a lightweight sound insulation structure has been required for improving energy efficiency. Examples of sound insulation structures forming sound insulation walls in vehicles and buildings are disclosed in Patent Documents 1 to 4.

[0003] In the invention described in Patent Document 1, in an acoustic attenuation panel including a rigid frame divided into a plurality of individual cells, a sheet of a flexible material, and a plurality of weights, each weight is fixed to the sheet of the flexible material so that a weight is provided in each cell, and the attenuated sound is controlled by an appropriate selection of the mass of the weights.

[0004] In the invention described in Patent Document 2, in a sound insulation material including an elastic sheet and a support portion that holds the sheet and partitions the sheet into partition portions, the relationship between the rigidity of the sheet in the partition portion and the surface density of the sheet is defined.

[0005] The sound insulation material of the invention described in Patent Document 3 is a structure including a flat substrate portion and a plurality of resonance portions connected to the substrate portion and having a predetermined resonance frequency. Each of the plurality of resonance portions has a weight portion and a connecting portion connecting the weight portion to the substrate portion. In a projection view seen from a direction perpendicular to the substrate portion, the center of gravity of the resonance portion is configured to be located outside the joint region between the substrate portion and the connecting portion.

[0006] The vibration reduction device of the invention described in Patent Document 4 has an acoustic metamaterial mounted on a vehicle body to block vibrations transmitted through the vehicle body, a cross-shaped frame mounted on the vehicle body to divide a certain space into certain regions, and a vibrator configured at a corner portion of each region partitioned by the frame to have respective natural vibration frequencies and block vibrations transmitted from the vehicle body through the frame.

[0007] Further, Patent Document 5 describes a sound insulation structure. This sound insulation structure has a side wall portion made of a sound insulation panel, and a noise source is accommodated in an accommodation space surrounded by the side wall portion. The sound insulation panel has a laminated structure of a resin plate material and a porous plate material. The resin plate material includes an upper closing wall having communication holes, a lower closing wall, and a side wall portion located between the upper closing wall and the lower closing wall.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] The acoustic attenuation panel described in Patent Document 1 has a rigid frame that is not flexible, and vibrations are transmitted to the sheet through this rigid frame, so there is a possibility that sufficient sound insulation cannot be obtained. Further, when the mounting surface on which the rigid frame is placed is curved or has irregularities, there is a possibility that the acoustic attenuation panel cannot be stably held. In particular, since there are many curved or irregular portions in the panels of general vehicles (e.g., automobiles) and machines that generate noise (e.g., generators and compressors), it is difficult to use them simply as sound insulation materials. Further, the rigid frame has a large mass, and an increase in mass due to the sound insulation material may be a problem.

[0010] The sound insulation material described in Patent Document 2 has a high height of the support portion, that is, a height extending in a direction orthogonal to the sheet from the sheet, and preferably 25 mm or more. In order to stably support the sheet by such a support portion having a high height, the support portion preferably has rigidity. As a result, there is a possibility that sufficient sound insulation cannot be obtained because vibrations are transmitted through the support portion, and it is difficult to mount it on a mounting surface having a curved surface or irregularities such as a panel of a vehicle (e.g., an automobile) or a machine that generates noise (e.g., a generator and a compressor). Further, there is a concern that such a support portion having a high height may cause an increase in the size and weight of the entire sound insulation material. In particular, when mounted on a vehicle panel or the like, there is a concern that the sound insulation material may occupy a large space inside the vehicle, reducing the space efficiency, interfering with the installation of other members, or disturbing the passengers.

[0011] In the sound insulation material described in Patent Document 3, the resonance portion, which is a functional portion that exhibits a sound insulation effect, is exposed without being covered by a support wall or the like. If another member or a human body contacts this resonance portion, the sound insulation property may decrease or change. Therefore, it is necessary to provide a large space around the resonance portion, resulting in a decrease in space efficiency.

[0012] The vibration reduction device described in Patent Document 4 does not have a film portion and is composed of a plurality of vibrators and a frame connecting them. Therefore, similar to the sound insulation material of Patent Document 3, the vibrators, which are functional parts that exhibit a sound insulation effect, are exposed. If another member or a human body comes into contact with this vibrator, the sound insulation performance may decrease or change. In addition, in order to ensure the minimum structural strength of the vibration reduction device, the frame is required to have rigidity. As a result, there is a possibility that sufficient sound insulation cannot be obtained because vibration is transmitted through the frame, and it is difficult to place it on a curved or uneven mounting surface such as a panel of a vehicle (e.g., an automobile) or a machine that generates noise (e.g., a generator or a compressor).

[0013] In the sound insulation structure described in Patent Document 5, since the side wall portion surrounding the noise source is constituted by a sound insulation panel including a resin plate material having communication holes and a porous plate material, it can be expected to exhibit a sound absorption effect, but it does not exhibit a remarkable sound insulation effect. Further, the resin plate material is composed of an upper closing wall, a lower closing wall, and a side wall portion, and is further laminated with the porous plate material. Therefore, this laminated structure is rigid, and it is difficult to place it on a curved or uneven mounting surface such as a panel of a vehicle (e.g., an automobile) or a machine that generates noise (e.g., a generator or a compressor), and the installability is poor.

[0014] Therefore, an object of the present invention is to provide a sound insulation structure that can obtain sufficient sound insulation performance, is thin and lightweight, has good sound insulation performance particularly in the low frequency range of 1000 Hz or less, has a flexible structure, can be easily and stably mounted on a surface having a curved or uneven shape at the mounting site, has an enclosure portion that at least partially covers the space isolated from the sound source (e.g., a mechanical device, etc.) or the sound source from the side, and can suppress the influence of the sound emitted by the sound source.

Means for Solving the Problems

[0015] The sound insulation structure of the present invention is a sound insulation structure having an enclosure portion that at least partially covers a sound source or a space isolated from the sound source from the side, wherein at least a part of the inner-facing surface of the enclosure portion has a sound insulation mechanism, the sound insulation mechanism having an elastic film portion, a support wall portion that stands on the film portion and has elasticity, and a weight portion that stands on the film portion, the film portion being divided into a plurality of compartments by the support wall portion, the weight portions being respectively located inside all of the plurality of compartments or inside some of the plurality of compartments, in the compartments where the weight portions are located inside, one weight portion is arranged in one compartment, the height of the support wall portion extending in a direction perpendicular to the film portion is larger than the height of the weight portion extending in a direction perpendicular to the film portion, and each of the weight portions constitutes a spring mass resonator having an elastic spring portion and a mass portion having a larger mass than the spring portion, which is characterized thereby. Here, the elasticity referred to herein means the property of a solid material deformed by an externally applied force to return to its original shape when the external force is removed, and includes energy elasticity and rubber elasticity (entropy elasticity). Herein, the case of having at least one of energy elasticity and rubber elasticity (entropy elasticity) is referred to as "having elasticity". The support wall portion and the spring portion may be made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. Similarly, the film portion may also be made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. The film portion, the support wall portion, and the spring portion may all have a dynamic storage elastic modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C. Also, the film portion, the support wall portion, and the spring portion may all be made of an elastic body having a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. Specifically, the elasticity of the film portion, the support wall portion, and the spring portion is evaluated by the dynamic storage modulus (E') obtained by measuring the frequency dependence in the tensile or compression mode of a dynamic viscoelasticity measuring device in accordance with JIS K7244 and obtaining a master curve based on 23°C. The dynamic storage modulus (E') at 23°C and a frequency of 1 Hz to 1000 Hz shall be 0.01 MPa or more and 100 MPa or less. Further, more preferably, both the film portion and the support wall portion may be made of an elastic body having a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less and a loss tangent of 0.05 or more and 0.45 or less at 23°C and a frequency of 1 Hz to 1000 Hz. The spring portion of the weight portion is located on the side attached to the film portion of the weight portion, and the mass portion may be located on the side opposite to the side attached to the film portion of the weight portion. The mass portion of the weight portion may have a larger volume than the spring portion. The mass portion of the weight portion may be made of a material having a higher density than the spring portion.

[0016] Another sound insulation structure of the present invention is a sound insulation structure having an enclosure portion that at least partially covers a sound source or a space to be isolated from the sound source from the side, wherein at least a part of the inner-facing surface of the enclosure portion has a sound insulation mechanism, and the sound insulation mechanism has an elastic film portion, a support wall portion that stands on the film portion and has elasticity, and a weight portion that stands on the film portion. The film portion is divided into a plurality of compartments by the support wall portion, and the weight portions are respectively located inside all of the plurality of compartments or inside a part of the plurality of compartments. In the compartment where the weight portion is located inside, one weight portion is arranged in one compartment. The height of the support wall portion extending in the direction orthogonal to the film portion is larger than the height of the weight portion extending in the direction orthogonal to the film portion, and the film portion serves as a spring portion and the weight portion serves as a mass portion to constitute a spring-mass resonator. The support wall portion may be made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. Similarly, the film portion may also be made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. Both the film portion and the support wall portion may have a dynamic storage modulus at 23°C in the frequency range of 1 Hz to 1000 Hz of 0.01 MPa or more and 100 MPa or less. Also, both the film portion and the support wall portion may be made of an elastic body having a loss tangent at 23°C in the frequency range of 1 Hz to 1000 Hz of 0.01 or more and 0.50 or less. More preferably, both the film portion and the support wall portion may be made of an elastic body having a dynamic storage modulus (E’) at 23°C in the frequency range of 1 Hz to 1000 Hz of 0.05 MPa or more and 50 MPa or less, and a loss tangent at 23°C in the frequency range of 1 Hz to 1000 Hz of 0.05 or more and 0.45 or less.

[0017] The sound insulation structure of the present invention described above and another sound insulation structure may have the following configuration. The surrounding portion may include a side plate portion that at least partially covers the sound source or the space from the side, and a top plate portion that at least partially covers the sound source or the space from above. A part of the side plate portion may constitute an openable and closable door portion. Four or more of the partitions may be provided on each of the top plate portion and the side plate portion, and the partitions may be arranged in a matrix. The support wall portion may include a plurality of first wall portions that extend in a direction perpendicular to the film portion and also extend in a first direction parallel to the film portion, and a plurality of second wall portions that extend in a direction perpendicular to the film portion and also extend in a second direction perpendicular to the first direction. The support wall portion may be cylindrical with a circular, elliptical or oval cross-sectional shape defining each of the compartments, or may be angular cylindrical with a polygonal cross-sectional shape defining each of the compartments, specifically a square, regular pentagon or regular hexagon cross-sectional shape. The area of each of the compartments may be 100 mm 2 or more and 1000 mm 2 or less. There may be provided 10 or more and 1000 or less of the compartments per 1000 cm 2 of the area of the film portion, and it is more preferable that 50 or more and 500 or less of the compartments are provided. The plate thickness of the support wall portion may be 0.5 mm or more and 5.0 mm or less, and it is more preferable that it is 1.0 mm or more and 3.0 mm or less. The film thickness of the film portion may be 0.1 mm or more and 3.0 mm or less. The height in the direction perpendicular to the film portion may be 5 mm or more and 20 mm or less. The height of the support wall portion extending in the direction perpendicular to the film portion may be 5 mm or more and 20 mm or less, and the height may be partially different. The height of the weight portion extending in the direction perpendicular to the film portion may be 1 mm or more. The durometer A hardness of the film portion may be 50 or more, and the durometer A hardness of the support wall portion may be 1 or more and 90 or less. The durometer A hardness can be obtained by measuring according to JIS K 6253-3.

Advantages of the Invention

[0018] According to the present invention, a sound insulation structure is provided that can obtain sufficient sound insulation performance, is thin and lightweight, and has good sound insulation performance particularly in the low frequency region of 1000 Hz or less. Since the structure is flexible, it can be easily and stably mounted on a curved surface or a surface having irregularities, and has an enclosure portion that at least partially covers the space separated from the sound source (for example, a mechanical device, etc.) or the sound source from the side, and can suppress the influence of the sound emitted by the sound source.

Brief Description of the Drawings

[0019]

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[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] FIG. 1(A) is a perspective view of the sound insulation structure 10 according to the first embodiment of the present invention as viewed from above, and FIG. 1(B) is a perspective view as viewed from below. FIG. 2 is a front sectional view of the sound insulation structure 10 of the present embodiment. The sound insulation structure 10 has an enclosure portion 11 that at least partially covers the sound source 12 or the space isolated from the sound source from the side. At least a part of the inner surface of the enclosure portion 11 facing inward has a sound insulation mechanism 1. Specifically, the sound insulation structure 10 of the present embodiment has a top plate portion 11a and four side plate portions 11b as the enclosure portion 11, and is a hollow square cylinder shape with an open bottom. The inner surfaces of each wall portion of the sound insulation structure 10, that is, the surfaces of the top plate portion 11a and each side plate portion 11b on the inner side (hollow portion side) of the square cylinder each have a sound insulation mechanism 1. As shown in FIG. 2, the sound insulation structure 10 is placed on an installation surface 13 (for example, the floor of a building, the upper surface of a desk or table, a vehicle panel, a machine that generates noise, etc.), and covers the upper and side of the sound source 12 schematically illustrated by a two-dot chain line.

[0021] FIG. 3(A) is a perspective view of the sound insulation mechanism 1 of the sound insulation structure 10 of the present embodiment, and FIG. 3(B) is a cross-sectional view taken along line A-A of FIG. 3(A) and turned upside down vertically. The sound insulation mechanism 1 has an elastic sheet-like film portion 2, a support wall portion 3 standing substantially vertically from the film portion 2, and a weight portion 4 standing substantially vertically from the film portion 2. The film portion 2 is divided into a plurality of compartments (unit structures) 5 by the support wall portion 3. The weight portions 4 are respectively located inside the plurality of compartments 5, and in the compartment 5 where the weight portion 4 is located inside, one weight portion 4 is located in one compartment 5. FIG. 4(A) is an exploded perspective view of one compartment 5 of the sound insulation mechanism 1, and FIG. 4(B) is an exploded front view thereof. The height H1 of the support wall portion 3 extending from the film portion 2 in a direction orthogonal to the film portion 2 is larger than the height H2 of the weight portion 4 extending from the film portion 2 in a direction orthogonal to the film portion 2. Each of the weight portions 4 constitutes a spring-mass resonator having an elastic spring portion 4a and a mass portion (mass part) 4b having a mass larger than that of the spring portion 4a. The elasticity referred to here means the property that a solid substance deformed by an externally applied force restores to its original shape when the external force is removed, and includes energy elasticity and rubber elasticity (entropy elasticity). Here, the case of having at least one of energy elasticity and rubber elasticity (entropy elasticity) is referred to as "having elasticity".

[0022] The support wall portion 3 of the present embodiment includes a plurality of first wall portions 3a extending in a first direction D1 parallel to the film portion 2, and a plurality of second wall portions 3b extending in a second direction D2 orthogonal to the first direction D1. The plurality of first wall portions 3a are arranged in parallel, and the plurality of second wall portions 3b are arranged in parallel. The first wall portion 3a and the second wall portion 3b are integrated at the intersection. In this way, the plurality of first wall portions 3a and the plurality of second wall portions 3b constitute a lattice structure, and a plurality of compartments 5 having a square planar shape partitioned by the first wall portion 3a and the second wall portion 3b are arranged in a matrix. In other words, the support wall portion 3 has a structure in which a plurality of square tubular members having a square cross-sectional shape defining individual compartments 5 are arranged side by side. The support wall portion 3 is preferably made of a flexible material such as rubber, elastomer, or resin foam. The flexible material referred to here is any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

[0023] A portion of the weight portion 4 of the present embodiment on the side attached to the film portion 2 is a spring portion 4a, and a portion on the side opposite to the side attached to the film portion 2 is a mass portion 4b having a larger mass than the spring portion 4a. In the examples shown in FIGS. 1 to 4, the spring portion 4a and the mass portion 4b have the same shape and the same dimensions, but different materials. The spring portion 4a is made of a flexible material, and the mass portion 4b is made of a material having a higher density than the material constituting the spring portion 4a. A spring-mass resonator is configured in which the spring portion 4a functions as a spring and the mass portion 4b functions as a mass. Note that, together with the spring portion 4a of the weight portion 4, the film portion 2 may also function as a part of the spring of the spring-mass resonator. Further, the air in the space surrounded by the film portion 2 and the support wall portion 3 may function as a part of the spring (air spring) of the spring-mass resonator. The spring portion 4a is also preferably made of any one of a flexible material, that is, a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

[0024] According to the sound insulation mechanism 1 of this embodiment, the vibration of the film portion 2 is controlled by the action of the spring mass resonator constituted by the spring portion 4a and the mass portion 4b of the weight portion 4. In particular, in a specific frequency range (for example, a frequency of 1000 Hz or less which is the main frequency band of road noise in an automobile, the frequency of noise generated by a generator or a compressor, or the frequency of human conversation), the film vibration is significantly reduced. As a result, the radiated sound from the film portion 2 becomes small, and high sound insulation performance is exhibited.

[0025] The partition 5 of the sound insulation mechanism 1 of this embodiment is preferably provided with 10 or more and 1000 or less per 1000 cm of the area of the film portion 2, and more preferably 50 or more and 500 or less. Since there are 10 or more per 1000 cm of the area of the film portion 2, the entire sound insulation mechanism 1 can be divided into a plurality of partitions 5 to exhibit a sound insulation effect for each partition, and the sound insulation performance of the entire sound insulation mechanism 1 is improved. Also, since there are 1000 or less per 1000 cm of the area of the film portion 2, an increase in the weight of the entire sound insulation mechanism 1 can be suppressed. The area of the planar shape of each partition 5 is preferably 100 mm 2 or more and 1000 mm 2 or less, and more preferably 200 mm 2 or more and 800 mm 2 or less. Since the area of the planar shape of each partition 5 is 100 mm 2 or more, it is easy to arrange the weight portion 4 inside. On the other hand, since the area is 1000 mm 2 or less 2 2 or more, it is easy to arrange the weight portion 4 inside. On the other hand, since the area is 1000 mm 2Therefore, since the following conditions are met, the effect of the weight portion 4 on the film portion 2 is significant, and high sound insulation performance can be obtained. It is preferable that the height of the entire sound insulation mechanism 1 in the direction orthogonal to the film portion 2 is 5 mm or more and 20 mm or less. When the height of the entire sound insulation mechanism 1 is 5 mm or more, the weight portion 4 can have a sufficient height as a spring mass resonator, and when the height is 20 mm or less, an increase in the weight of the entire sound insulation mechanism 1 can be suppressed. Note that each drawing schematically shows each section 5, the support wall portion 3, etc. There may be cases where the number and area of the sections 5 and the height of the support wall portion 3 are not strictly and accurately shown, or cases where they are not unified in each drawing. However, it is preferable that the number and area of the sections 5 and the height of the support wall portion 3 are appropriately designed so as to fall within the numerical ranges described above, respectively.

[0026] In this embodiment, the film portion 2, the support wall portion 3, and the spring portion 4a of the sound insulation mechanism 1 are all made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, and a loss tangent (tanδ) of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. Preferably, the dynamic storage modulus (E') is 0.05 MPa or more and 50 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, and the loss tangent (tanδ) is 0.05 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. The dynamic storage modulus (E') and the loss tangent (tanδ) are obtained by creating a master curve based on 23°C using a dynamic viscoelasticity tester. Since the dynamic storage modulus (E') at a frequency of 1 Hz to 1000 Hz at 23°C is 0.01 MPa or more, the sound insulation performance in the target frequency band is good, and the shape retention of the film portion 2 and the support wall portion 3 is good. Since the dynamic storage modulus (E') at a frequency of 1 Hz to 1000 Hz at 23°C is 100 MPa or less, the vibration in the frequency band to be sound-insulated is good, the sound insulation mechanism 1 does not become rigid, and the installability is also good. The film portion 2 and the support wall portion 3 may be formed of the same material or different materials. The film portion 2 is preferably made of a flexible material, that is, a material having no energy elasticity and having rubber elasticity, a material having no rubber elasticity and having energy elasticity, or a material having both rubber elasticity and energy elasticity.

[0027] Since the hammer part 4 is attached to the diaphragm part 2, the diaphragm part 2 is preferably an elastic membrane that is relatively hard. The dynamic storage elastic modulus (E’) of the diaphragm part 2 is preferably 15 MPa or more, the thickness (membrane thickness) is preferably 0.1 mm or more and 3.0 mm or less, and more preferably about 0.5 mm. When the thickness of the diaphragm part 2 is 0.1 mm or more, a sufficient thickness can be ensured, so that it is easy to handle. Since the thickness of the diaphragm part 2 is 3.0 mm or less, an increase in the thickness and weight of the entire sound insulation mechanism 1 can be suppressed, and the entire sound insulation mechanism 1 does not become too hard and has good installability. The material of the diaphragm part 2 preferably has a durometer A hardness of 50 or more according to JIS K6253, and more preferably 70 or more. By setting the durometer A hardness of the diaphragm part 2 within the above range, deterioration of the vibration of the diaphragm part 2 is prevented, and the sound insulation performance in the frequency band to be sound-insulated becomes good. And the rigidity (axial rigidity) k of the diaphragm part 2 is expressed as k = E’ × A / L from the dynamic storage elastic modulus E’, the cross-sectional area A of the diaphragm part 2, and the thickness L of the diaphragm part 2. When the area of the diaphragm part 2 to be evaluated for rigidity is 1000 cm 2 When it is, the rigidity k is 10 6 N / mm or more and 10 9 N / mm or less, preferably 3 × 10 6 N / mm or more and 10 8 N / mm or less, more preferably. When the area of the diaphragm part 2 is 1000 cm 2 When it is, the rigidity is 10 6 N / mm or more, whereby deterioration of the vibration of the diaphragm part 2 can be suppressed, and the sound insulation performance in the frequency band to be sound-insulated becomes good. When the area of the diaphragm part 2 is 1000 cm 2 When it is, the rigidity is 10 9 N / mm or less, whereby the sound insulation mechanism 1 becomes flexible and has good installability. Further, the bending rigidity K of the diaphragm part 2 is expressed as K = E’ × I from the dynamic storage elastic modulus E’ and the second moment of area I. The second moment of area I is calculated as I = b × h 3 / 12 from the thickness h and the width b of the diaphragm part 2. When the area of the diaphragm part 2 to be evaluated is 1000 cm 2 When it is, the bending rigidity K is 1 N / mm 2 or more and 10 5 N / mm2 It is preferably the following, 10 N / mm 2 or more and 5×10 4 N / mm 2 or less is more preferable. When the area of the film portion 2 is 1000 cm 2 the bending rigidity K is 1 N / mm 2 or more, the vibration of the film portion 2 becomes good, and it is possible to suppress deterioration of the sound insulation property in the frequency band to be sound-insulated. When the area of the film portion 2 is 1000 cm 2 the bending rigidity K is 10 5 N / mm 2 or less, the sound insulation mechanism 1 becomes flexible and the installability becomes good. The cross-sectional shape of the film portion 2 is not particularly limited, and it may be flat or may have irregularities.

[0028] Examples of the material for the diaphragm portion 2 include crosslinked (vulcanized) rubber, thermoplastic elastomer, and plastic. Examples of the crosslinked (vulcanized) rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), and ethylene-butene-diene rubber (EBDM) such as ethylene·α-olefin·non-conjugated polyene copolymers, chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), acrylic rubber (ACM), ethylene-acrylic rubber (AEM), ethylene-vinyl acetate rubber (EVA), epichlorohydrin rubber (CO, ECO), polysulfide rubber (T), silicone rubber (Q) such as methyl vinyl silicone rubber (VMQ) and fluorosilicone rubber (FVMQ), urethane rubber (U), and various rubber materials such as fluororubber (FKM) crosslinked (vulcanized). These crosslinked (vulcanized) rubbers can be used alone or in combination of two or more. Note that as the crosslinking (vulcanizing) method, for example, a method of crosslinking (vulcanizing) by heating using an organic peroxide, phenol resin, oxime compound, sulfur, sulfur-based compound, or polyamine compound as a crosslinking agent (vulcanizing agent), or a method of crosslinking by irradiating with an electron beam can be mentioned. Note that the crosslinked (vulcanized) rubber may generally be blended with various known blending agents (reinforcing agents such as carbon black and silica, fillers such as calcium carbonate, softening agents such as paraffin oil and plasticizer, processing aids, antioxidants, light stabilizers, flame retardants, antifungal agents, acid acceptors, silane coupling agents, antistatic agents, ultraviolet absorbers, etc.) used as rubber compounding agents. These crosslinked (vulcanized) rubbers, crosslinking agents (vulcanizing agents), and blending agents may be made of biomass raw materials.

[0029] Examples of the thermoplastic elastomer include an olefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyvinyl chloride-based thermoplastic elastomer, an ethylene-vinyl acetate-based thermoplastic elastomer, and the like. Examples of the plastic include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, or a composite resin containing them. These thermoplastic elastomers and plastics may be made of biomass raw materials.

[0030] Specifically, the material of the film portion 2 is preferably ethylene-propylene-diene rubber, a thermoplastic olefin-based elastomer, a thermoplastic styrene-based elastomer, polyethylene, polypropylene, polyethylene terephthalate, thermoplastic polyurethane, or the like.

[0031] The support wall portion 3 is preferably made of a soft and flexible material within a range capable of supporting the film portion 2. The plate thickness of the support wall portion 3 is preferably 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm or less. When the plate thickness of the support wall portion 3 is 0.5 mm or more, the shape retention of the sound insulation mechanism 1 becomes good. When the plate thickness of the support wall portion 3 is 5.0 mm or less, the vibration of the film portion 2 is good, the sound insulation performance in the frequency band to be sound-insulated is good, and an increase in the weight of the entire sound insulation mechanism 1 can be suppressed. The height extending in the direction orthogonal to the film portion 2 of the support wall portion 3 is preferably 5 mm or more and 20 mm or less, and more preferably 10 mm or more and 20 mm or less. The support wall portion 3 may be partially different in height. When the height of the support wall portion 3 is partially different, the higher portion of the height may be 10 mm or more and 20 mm or less, more preferably 12 mm or more and 20 mm or less, and even more preferably 14 mm or more and 20 mm or less. Since the height of the support wall portion 3 is not too low, the weight portion 4 can have a sufficient height as a spring mass resonator. Since the height of the support wall portion 3 is not too high, the overall weight can be reduced. The material of the support wall portion 3 preferably has a durometer A hardness of 1 or more and 90 or less according to JIS K6253, and more preferably 10 or more and 70 or less. When the durometer A hardness of the support wall portion 3 is 1 or more, the shape retention of the sound insulation mechanism 1 can be maintained. When the durometer A hardness of the support wall portion 3 is 90 or less, it is possible to prevent the vibration from the support wall portion 3 from being transmitted to the film portion 2 and deteriorating the sound insulation performance, and the sound insulation mechanism 1 becomes flexible and the installability becomes good. And the rigidity k of the support wall portion 3 is expressed as k = E'×A / L from the dynamic storage elastic modulus E', the cross-sectional area A of the support wall portion 3, and the height L of the support wall portion 3. When the area of the support wall portion 3 to be evaluated for rigidity is 1000 cm 2 When it is, the rigidity k is preferably 10 N / mm or more and 10 6 N / mm or less, and more preferably 10 2 N / mm or more and 10 5 N / mm or less. When the area of the support wall portion 3 is 1000 cm 2When the rigidity k is 10 N / mm or more, the shape retention of the sound insulation mechanism 1 can be maintained. The area of the support wall portion 3 is 1000 cm 2 When the rigidity k is 10 6 N / mm or less, vibration from the support wall portion 3 is prevented from being transmitted to the film portion 2, preventing deterioration of the sound insulation performance, and the sound insulation mechanism 1 is not rigid and has good installability.

[0032] Examples of the material of the support wall portion 3 include crosslinked (vulcanized) rubber, thermoplastic elastomer, resin foam, etc. The crosslinked (vulcanized) rubber and thermoplastic elastomer may be the same as the materials listed as the material of the film portion 2. The resin foam may have a closed cell structure or an open cell structure, and examples include polyurethane foam, polystyrene foam, polyethylene foam, ethylene-vinyl acetate rubber (EVA) foam, etc. Specifically, the material of the support wall portion 3 is preferably ethylene-propylene-diene rubber, urethane rubber, silicone rubber, thermoplastic olefin-based elastomer, thermoplastic styrene-based elastomer, thermoplastic polyurethane, polyurethane foam, etc. These resin foams may be made of biomass raw materials.

[0033] The material of the spring portion 4a of the weight portion 4 is a flexible material such as crosslinked (vulcanized) rubber, thermoplastic elastomer, resin foam, etc. The crosslinked (vulcanized) rubber, thermoplastic elastomer, and resin foam may be the same as the materials listed as the material of the support wall portion 3. Specifically, the material of the spring portion 4a of the weight portion 4 is preferably ethylene-propylene-diene rubber, urethane rubber, silicone rubber, thermoplastic olefin-based elastomer, thermoplastic styrene-based elastomer, thermoplastic polyurethane, polyurethane foam, etc. These materials may be made of biomass raw materials.

[0034] The material of the mass portion 4b is not particularly limited, and it may be made of resin, metal, or the like. The mass portion 4b has a greater mass than the spring portion 4a, and has a mass of, for example, 0.1 g or more and 2.0 g or less. Preferably, the mass portion 4b has a mass that is at least twice the mass of the spring portion 4a. By having the weight of the mass portion 4b be at least twice the mass of the spring portion 4a, the weight portion 4 can be sufficiently resonated in the frequency range to be sound-insulated, and a good sound-insulating effect can be obtained. When the material of the mass portion 4b is resin, the resin may be made of biomass raw materials.

[0035] The spring constant (rigidity) of the spring portion 4a is determined based on the mass of the mass portion 4b so that the resonance frequency matches the frequency that is the main sound-insulation target. As an example, when the mass of the mass portion 4b is 1.0 g and the frequency that is the main sound-insulation target is 1000 Hz or less, the spring constant of the spring portion 4a is 0.5 N / mm or more and 100 N / mm or less, and more preferably 1 N / mm or more and 50 N / mm or less.

[0036] With such a configuration, each of the film portion 2, the support wall portion 3, and the weight portion 4 is relatively lightweight, and the dimension in the direction orthogonal to the film portion 2 is relatively small. Thus, although the sound-insulation mechanism 1 of the present embodiment is lightweight and thin, as described above, high sound insulation can be obtained in a specific frequency range (for example, a frequency of 1000 Hz or less, which is the main frequency band of road noise in an automobile, the frequency of noise generated by a generator or a compressor, or the frequency of human conversation). When this sound-insulation mechanism 1 is adopted in a part of the sound-insulation structure 10 shown in FIGS. 1 to 2 (for example, the inner surfaces of the top plate portion 11a and each side plate portion 11b), the sound generated by the sound source 12, at least a part of which is surrounded by the sound-insulation structure 10, can be favorably blocked. This sound-insulation structure 10 can be easily and stably installed on a planar mounting surface, a curved mounting surface, or a mounting surface having irregularities, without being fixed by adhesion or the like.

[0037] FIG. 5(A) is a perspective view of the sound insulation mechanism 1 of the sound insulation structure 10 according to a modified example of the first embodiment of the present invention, and FIG. 5(B) is a cross-sectional view taken along line A-A of FIG. 5(A) and turned upside down. FIG. 6(A) is a cross-sectional view of the sound insulation mechanism 1 of the sound insulation structure 10 according to another modified example, and FIG. 6(B) is a perspective view of the weight portion 4 of the sound insulation mechanism 1. FIG. 7(A) is a cross-sectional view of the sound insulation mechanism 1 of the sound insulation structure 10 according to still another modified example, and FIG. 7(B) is a perspective view of the weight portion 4 of the sound insulation mechanism 1. In the modified example shown in FIGS. 5(A) and 5(B), the spring portion 4a has a small-diameter cylindrical shape, and the mass portion 4b has a large-diameter cylindrical shape. In the modified example shown in FIGS. 6(A) and 6(B), the spring portion 4a has an elongated cylindrical shape, the mass portion 4b has a spherical shape, and the diameter of the cross-sectional shape of the cylindrical spring portion 4a is smaller than the diameter of the spherical mass portion 4b. In the modified example shown in FIGS. 7(A) and 7(B), the spring portion 4a has a frustum of a cone shape, the mass portion 4b has a cylindrical shape, and the diameter of the smallest portion of the frustum of a cone-shaped spring portion 4a substantially coincides with the diameter of the cylindrical mass portion 4b. In the modified examples shown in FIGS. 5 to 6, the mass portion 4b has a larger volume than the spring portion 4a. Therefore, even if the spring portion 4a and the mass portion 4b are formed of the same material, the mass portion 4b has a larger mass than the spring portion 4a and can constitute a spring-mass resonator. However, in this modified example, the spring portion 4a and the mass portion 4b may be formed of different materials and the mass portion 4b may have a larger mass than the spring portion 4a. On the other hand, in the modified example shown in FIGS. 7(A) and 7(B), the spring portion 4a has a larger volume than the mass portion 4b. In this case, the mass portion 4b is formed of a material having a higher density than the spring portion 4a, the mass portion 4b has a larger mass than the spring portion 4a, and a spring-mass resonator can be constituted. When the spring portion 4a has a frustum of a cone shape that tapers in a direction away from the diaphragm portion 2 as in the modified example shown in FIGS. 7(A) and 7(B), the mold release property from the mold when the diaphragm portion 2 and the spring portion 4a are integrally formed is good. The shape and dimensions of the weight portion 4 of the present invention are not limited, and the shapes shown in FIGS. 3 to 7 and various other shapes not shown can be adopted. The weight portion 4 is formed in an arbitrary shape and dimension selected so as to satisfy the performance of the spring-mass resonator required for sound insulation and to be accommodated in the partition 5.

[0038] In this embodiment, the spring portion 4a and the mass portion 4b of the weight portion 4 are made to have different materials and / or volumes, so that the mass of the mass portion 4b is made larger than that of the spring portion 4a to form a spring-mass resonator, thereby obtaining a sufficient sound insulation effect. That is, the materials, shapes, and dimensions of the spring portion 4a and the mass portion 4b are determined so that a spring-mass resonator capable of exhibiting a sufficient sound insulation effect can be formed. As long as the mass of the mass portion 4b can be made larger than that of the spring portion 4a to such an extent that a spring-mass resonator capable of exhibiting a sufficient sound insulation effect is formed, the materials, shapes, and dimensions of the spring portion 4a and the mass portion 4b can be freely selected. However, since the spring portion 4a functions as a spring, it needs to be formed from a flexible material.

[0039] [Second Embodiment] FIG. 8(A) is a perspective view of the sound insulation mechanism 6 of the sound insulation structure 10 according to the second embodiment of the present invention, and FIG. 8(B) is a cross-sectional view taken along the line A-A in FIG. 8(A) and turned upside down. In this embodiment, similar to the sound insulation structure 10 of the first embodiment shown in FIGS. 1 to 2, although not shown, the inner surfaces (hollow portion side) of the top plate portion and each side plate portion of the sound insulation structure each have a sound insulation mechanism 6. This sound insulation mechanism 6 has a weight portion 7 having a single structure that is not divided into a spring portion and a mass portion. In this embodiment, a spring-mass resonator is formed in which the entire weight portion 7 functions as a mass portion and the film portion 2 functions as a spring portion. As an example, the mass of the weight portion 7 is about 0.1 g to 2.0 g. The material of the weight portion 7 is not limited, and it is formed of, for example, a synthetic resin or metal. Since the other configurations are the same as those of the first embodiment described above, the description thereof is omitted. Also in the sound insulation mechanism 6 of this embodiment, the membrane vibration is controlled by the action of the spring-mass resonator formed by the weight portion 7 and the film portion 2, and in a specific frequency range (for example, 1000 Hz or less), the membrane vibration is significantly reduced, and high sound insulation performance is exhibited. Note that, together with the film portion 2, the air in the space surrounded by the film portion 2 and the support wall portion 3 may function as a part of the spring (air spring) of the spring-mass resonator.

[0040] Both the film part 2 and the support wall part 3 of this embodiment preferably have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, and preferably have a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. Further, both the film part 2 and the support wall part 3 of this embodiment more preferably have a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, and a loss tangent (tanδ) of 0.05 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C.

[0041] In addition, the support wall part 3 of this embodiment is made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. Similarly, the film part 2 of this embodiment is also made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

[0042] Although not shown, in the sound insulation structure 10 of a modification of the second embodiment of the present invention, the weight part 7 has a frustum of a cone shape that tapers in a direction away from the film part 2. In this configuration, the mold release property from the mold when the film part 2 and the weight part 7 are integrally formed is good. In this embodiment, the shape of the weight part 7 can be arbitrarily determined and is not particularly limited.

[0043] In any of the first to second embodiments, the film part 2 and the support wall part 3 can be formed by integral molding or two-color molding such as injection molding, compression molding, press molding, extrusion molding, transfer molding, casting, etc. of the above-described materials. Further, at least a part of the weight parts 4 and 7 may also be formed together with the film part 2 and the support wall part 3 by integral molding, two-color molding, insert molding, etc. of the above-described materials. However, the sound insulation mechanisms 1 and 6 may be assembled by forming the film part 2, the support wall part 3, and the weight parts 4 and 7 separately and then joining them to each other by adhesion or heat fusion.

[0044] In the configurations of the sound insulation mechanisms 1 and 6 described above, as shown in FIGS. 9(A) and 9(B), the support wall portion 3 includes a plurality of first wall portions 3a extending in a first direction D1 parallel to the film portion 2 and a plurality of second wall portions 3b extending in a second direction D2 orthogonal to the first direction D1, and the planar shape of each partition 5 is square. In other words, the support wall portion 3 has a square tubular shape having a square cross-sectional shape that defines each partition 5, and a plurality of square tubular support wall portions 3 are arranged side by side, and the support wall portions 3 of adjacent partitions 5 are integrated. However, it is not limited to such a configuration. For example, although not shown, the planar shape of each partition 5 may be triangular, and the support wall portion 3 may have a triangular tubular shape having a triangular cross-sectional shape that defines each partition 5. Also, although not shown, the planar shape of each partition 5 may be pentagonal, and the support wall portion 3 may have a pentagonal tubular shape having a pentagonal cross-sectional shape that defines each partition 5. As shown in FIGS. 10(A) and 10(B), the planar shape of each partition 5 may be hexagonal, and the support wall portion 3 may have a hexagonal tubular shape having a hexagonal cross-sectional shape that defines each partition 5, constituting a so-called honeycomb structure. Furthermore, although not shown, the planar shape of each partition 5 may be circular, and the support wall portion 3 may have a cylindrical shape having a circular cross-sectional shape that defines each partition 5. In the case of a configuration where the planar shape of each partition 5 is pentagonal or circular, a gap is formed between the partitions 5, so it is preferable to determine the shape and dimensions of the support wall portion 3 so that the gap becomes smaller, and it is preferable that the film portion 2 extends so as to close the gap. In the case of a configuration where the planar shape of each partition 5 is quadrilateral, triangular, or hexagonal, no gap is formed between the partitions 5. Furthermore, each partition 5 may have various shapes not shown, for example, rectangular, parallelogram, trapezoid, polygon with seven or more sides, oval, oblong, etc., or may have an irregular shape. The support wall portion 3 is formed in a shape and dimensions corresponding to the planar shape of each partition 5.

[0045] In the sound insulation structure 10 according to the first and second embodiments of the present invention, at least a part of the top plate portion and the side plate portion that cover a part of the sound source 12 from above and from the side are composed of sound insulation mechanisms 1 and 6 including a film portion 2, a support wall portion 3, and weight portions 4 and 7. Thereby, a sound insulation effect against the sound from the sound source 12 can be obtained. And the sound insulation structure 10 can be easily placed on a surface having a curved surface or unevenness, and may be placed and used on a panel of a vehicle, particularly an automobile. A panel of an automobile or the like is basically a non-ventilated plate. As an example, a metal plate (iron plate, steel plate, aluminum plate), a resin plate, etc. may be mentioned. When the panel on which the sound insulation structure 10 is placed is a metal plate, its thickness is preferably in the range of 0.5 mm to 2.0 mm, and when it is a resin plate, its thickness is preferably in the range of 0.5 mm to 20 mm. The sound insulation structure 10 may or may not be adhered to the mounting surface of a panel, a machine, etc., but it is preferable that the sound insulation structure 10 is not adhered to the mounting surface of a panel, a machine, etc. and is placed and used on the mounting surface.

[0046] As a part for installing the sound insulation structure 10 of the present invention in an automobile, in the engine compartment, there are an engine head cover, an engine body cover, a hood insulator, a dash front insulator, the wall of an air box, a cleaner of an air intake, a dust side duct, an under cover, etc.; in the cabin, there are a dash insulator, a dash panel, a floor carpet (floor silencer), a spacer, a door trim of a door, the inside of the door trim, an instrument panel, an instrument center box, an instrument upper box, a housing of an air conditioner, a roof trim, the inside of the roof trim, a sun visor, a rear seat air conditioner duct, a cooling duct of a battery cooling system in a battery-mounted vehicle, a cooling fan, a trim of a center console, the inside of the console, a parcel trim, a parcel panel, a headrest of a seat, a seat back of a front seat, a seat back of a rear seat, etc.; in the trunk, there are a trim of a trunk side, the inside of the trim, a drafter cover, etc. Further, the sound insulation structure 10 of the present invention can also be installed inside the skeleton of the automobile or between panels, and furthermore, it can also be installed on an under cover under the floor located outside the vehicle, a fender protector, a back door, a wheel cover, an aerodynamic cover of a suspension, etc.

[0047] Examples of the use of the sound insulation structure 10 of the present invention are schematically shown in FIGS. 11 to 14. However, for clarity, the specific and detailed shapes of the sound insulation mechanisms 1 and 6 of each sound insulation structure 10 in FIGS. 11 to 14 are not shown. In the use examples shown in FIGS. 11(A) to 11(D), the sound insulation structure 10 at least partially covers various sound sources. In the use example shown in FIG. 11(A), at least a part of the surface of the sound insulation structure 10 (engine cover) that covers the vehicle engine 21 from above and laterally and faces the engine 21 is composed of any one of the sound insulation mechanisms 1 and 6 having the above-described configuration. In the use example shown in FIG. 11(B), at least a part of the surface of the sound insulation structure 10 (generator cover) that covers a device such as a generator 22 from the side and faces the generator 22 is composed of any one of the sound insulation mechanisms 1 and 6 having the above-described configuration. This sound insulation structure 10 is open without covering the upper part of the generator 22. Also, a part of this sound insulation structure 10 constitutes an openable and closable door portion. In the use example shown in FIG. 11(C), at least a part of the surface of the sound insulation structure 10 that covers a large device such as a compressor 23 from the side and faces the compressor 23 is composed of any one of the sound insulation mechanisms 1 and 6 having the above-described configuration. This sound insulation structure 10 is open without covering the upper part of the compressor 23. Also, a part of this sound insulation structure 10 constitutes an openable and closable door portion. In the use example shown in FIG. 11(D), at least a part of the surface of the sound insulation structure 10 that covers a part other than the attachment portion of the ventilation fan 24 to the building wall and faces the ventilation fan 24 is composed of any one of the sound insulation mechanisms 1 and 6 having the above-described configuration.

[0048] In the usage examples shown in FIGS. 12 to 14, the sound insulation structure 10 at least partially covers a space isolated from the sound source. In the usage example shown in FIG. 12, a desktop booth placed on the workbench 25 is composed of the sound insulation structure 10 of the present invention. This sound insulation structure 10 (desktop booth) covers a part of the space on the workbench 25 where a computer (not shown) etc. is placed from the side and above, and at least a part of the inner-facing surface of this sound insulation structure 10 is composed of either the sound insulation mechanism 1 or 6 having the above-described configuration. In the usage example shown in FIG. 13, a partition that is installed on the floor surface where the conference table 26 is placed and covers a part of the wide space where the conference table 26 is installed and a plurality of people enter from the side is composed of the sound insulation structure 10 of the present invention. At least a part of the inner-facing surface of this sound insulation structure 10 (partition) is composed of either the sound insulation mechanism 1 or 6 having the above-described configuration. This sound insulation structure 10 leaves the upper part of the space where the conference table 26 is installed and a plurality of people enter open without covering it. In the usage example shown in FIG. 14, a booth that covers a space of a size that can accommodate one person from above and a part of the side is composed of the sound insulation structure 10 of the present invention. The inner-facing surface of this sound insulation structure 10 (booth) of a space of a size that can accommodate one person is composed of either the sound insulation mechanism 1 or 6 having the above-described configuration. This sound insulation structure 10 has an open entrance and exit for people to enter and exit.

[0049] As shown in the usage examples shown in FIGS. 12 to 14, when the sound insulation structure 10 is used and arranged to at least partially cover the space isolated from the sound source, only the sound insulation structure 10 may be used alone, or an external member that supports the sound insulation structure 10 (not shown in the figure and not included in the sound insulation structure 10, such as a panel, a frame, or a punching metal) may be used together with the sound insulation structure 10. The material and shape of the external member are not particularly limited and can be arbitrarily set according to the application. The method of supporting the sound insulation structure 10 by the external member is not particularly limited. For example, when the external member is a panel or the like, the external member may be mounted on the surface opposite to the surface in contact with the film portion 2 of the support wall portion 3. When the external member is a frame, in addition to the method similar to the panel described above, a method of connecting and supporting a plurality of sound insulation structures 10 with a frame-shaped external member may also be adopted. Also, as shown in the usage examples shown in FIGS. 12 to 14, when the sound insulation structure 10 is used and arranged to at least partially cover the space isolated from the sound source, since the sound insulation structure 10 has a flexible structure, the sound insulation structure 10 can be arranged according to the shape of the space isolated from the sound source or the shape of the above external member. Specifically, the sound insulation structure 10 can also be arranged in a curved surface shape or an uneven shape.

[0050] As described above, the sound insulation structure 10 of the present invention can be adopted for a cover that covers at least a part of various devices and facilities, or a booth or partition that covers at least a part of a part of the human body or a space where one or more people enter. The sound insulation structure 10 may have an arbitrary shape such as a cube, a rectangular parallelepiped, a conical shape, a dome shape, or a booth shape. It is preferable that each part of the sound insulation mechanism 1, 6 of the sound insulation structure 10 is provided with four or more compartments 5 arranged in a matrix of at least 2×2 or more.

[0051] According to the sound insulation structure 10 of the present invention, it is thin and lightweight, has good sound insulation performance particularly in the low frequency range of 1000 Hz or less, and has a flexible structure. Therefore, it can be easily and stably mounted on a mounting site that is curved or has uneven surfaces. And, the surrounding portion 11 that at least partially covers the space separated from the sound source 12 (for example, a mechanical device, etc.) from the side can suppress the influence of the sound emitted by the sound source 12.

Example

[0052] Specific examples and comparative examples of the present invention will be described below. [Example 1] The sound insulation mechanism 1 of the sound insulation structure 10 of Example 1 of the present invention has the same structure as the first embodiment shown in FIGS. 3 to 4. The film portion 2 is made of an elastic body having a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, and a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. More specifically, the film portion 2 of this example has a dynamic storage modulus (E') of 20.4 MPa and a loss tangent (tanδ) of 0.12 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 23.0 MPa and a loss tangent (tanδ) of 0.13 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 25.4 MPa and a loss tangent (tanδ) of 0.16 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 28.8 MPa and a loss tangent (tanδ) of 0.14 at a frequency of 1000 Hz at 23°C, a durometer A hardness of 70 according to JIS K6253, and is made of EPDM (ethylene-propylene-diene rubber) with a film thickness of 0.5 mm. When the planar shape of this film portion 2 is a square with an area of 1000 cm 2 is a square, the flexural rigidity K is 67.2 N / mm 2 and when the planar shape is a square with an area of 400 cm 2 is a square, the flexural rigidity K is 42.5 N / mm 2 is. Hypothetically, with the same material as this film portion 2, a film thickness of 3 mm, and a planar shape with an area of 1000 cm 2When a film portion in the shape of a square is formed, its flexural rigidity K is approximately 1.5×10 4 N / mm 2 .

[0053] The support wall portion 3 of this embodiment is made of an elastic body having a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less and a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. More specifically, the support wall portion 3 of this embodiment has a dynamic storage modulus (E') of 13.2 MPa and a loss tangent (tanδ) of 0.12 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 15.0 MPa and a loss tangent (tanδ) of 0.14 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 17.4 MPa and a loss tangent (tanδ) of 0.17 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 20.2 MPa and a loss tangent (tanδ) of 0.16 at a frequency of 1000 Hz at 23°C, a durometer A hardness of 65 according to JIS K6253, a plate thickness of 1.6 mm, and is made of EPDM with a height in the direction orthogonal to the film portion 2 of 10 mm. However, only the outermost support wall portion 3 has a plate thickness of 0.8 mm, which is half. The compartment 5 defined by the plurality of support wall portions 3 (the first wall portion 3a and the second wall portion 3b) is square in shape with sides of 25 mm × 25 mm, and there are 49 compartments 5 in the 200 mm × 200 mm square region (evaluation surface) of the film portion 2. However, only a part of this region is schematically shown in the drawing. The weight portion 4 is cylindrical with a diameter of 6 mm and a height (dimension in the direction orthogonal to the film portion 2) of 6 mm.

[0054] Among the weight portion 4, the spring portion 4a, which is the portion on the side attached to the film portion 2, has a height of 3 mm, a dynamic storage modulus at a frequency of 1 Hz to 1000 Hz at 23°C of 0.01 MPa or more and 100 MPa or less, and a loss tangent at a frequency of 1 Hz to 1000 Hz at 23°C within the range of 0.01 or more and 0.50 or less. More specifically, the spring portion 4a of this embodiment has a dynamic storage modulus (E') of 0.60 MPa and a loss tangent (tanδ) of 0.17 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 0.74 MPa and a loss tangent (tanδ) of 0.24 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 0.97 MPa and a loss tangent (tanδ) of 0.17 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 1.31 MPa and a loss tangent (tanδ) of 0.16 at a frequency of 1000 Hz at 23°C, and is made of a silicone rubber with a durometer A hardness of 10 according to JIS K6253. The mass portion 4b, which is the portion of the weight portion 4 on the side opposite to the side attached to the film portion 2, also has a height of 3 mm and is made of rigid stainless steel (SUS304). The mass of the weight portion 4 is approximately 0.8 g, and it has a resonance peak at a frequency of 600 Hz to 650 Hz with respect to the direction perpendicular to the installation surface of the weight portion 4. The overall height of the sound insulation mechanism 1 is 10.5 mm, and the total areal density including the film portion 2, the support wall portion 3, and the weight portion 4 in one compartment 5 is 2.97 kg / m 2 is. Note that the areal density is a value calculated from the weight and area of the sample.

[0055] The sound insulation performance of the end face of the support wall portion 3 of the sound insulation mechanism 1 of this embodiment, which is on the side opposite to the side attached to the film portion 2, was measured with the incident sound side. Specifically, in accordance with the intensity method shown in JIS A1441-1, using a test facility room where the sound source room is a reverberation room and the receiving room is a semi-anechoic room, the acoustic transmission loss (transmission loss) [dB] with respect to the 1 / 3 octave band center frequency [Hz] by 1 / 3 octave band analysis was obtained. The relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss was obtained and is shown in FIGS. 15(A) to 15(C), 16(A) to 16(C), and 18(B). The higher the acoustic transmission loss, the higher the sound insulation performance. Note that at the 1 / 3 octave band center frequency [Hz] shown in FIGS. 15(A) to 18(B), 1 kHz is 1000 Hz, and the prefix "k" means 1000.

[0056] [Example 2] The sound insulation mechanism 6 of the sound insulation structure 10 of Example 2 of the present invention has the same structure as the second embodiment shown in FIG. 8. The film portion 2 and the support wall portion 3 of this embodiment are the same as the film portion 2 and the support wall portion 3 of Example 1. And the weight portion 7 is made of EPDM with a durometer A hardness of 65 according to JIS K6253-3, and is a cylindrical shape with a diameter of 13 mm and a height (dimension in the direction orthogonal to the film portion 2) of 5 mm. The mass of the weight portion 7 is about 0.85 g, and the areal density of this configuration is 3.04 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 6 of this embodiment was obtained in the same manner as in Example 1 and is shown in FIG. 15(B).

[0057] [Example 3] The sound insulation mechanism 6 of the sound insulation structure 10 of Example 3 of the present invention shown in FIG. 19 has the same structure as Example 2, but has a weight portion 7 that is smaller than the weight portion 7 of Example 2. FIG. 19(A) is a perspective view of the sound insulation mechanism 6, and FIG. 19(B) is a cross-sectional view cut along the line A-A and turned upside down. The film portion 2 and the support wall portion 3 of this embodiment are the same as the film portion 2 and the support wall portion 3 of Example 1. The weight portion 7 is made of EPDM with a durometer A hardness of 65 according to JIS K6253-3, and is a cylindrical shape with a diameter of 6 mm and a height (dimension in the direction orthogonal to the film portion 2) of 5 mm. The mass of the weight portion 7 is about 0.15 g. The areal density of this configuration is 2.54 kg / m2 It is. The sound insulation performance of the sound insulation mechanism 6 of this example was determined in the same manner as in Example 1 and is shown in FIG. 15(B).

[0058] [Example 4] The sound insulation mechanism 1 (not shown) of the sound insulation structure 10 of Example 4 of the present invention has the same structure as that of Example 1, but has a support wall portion 3 that is softer than the support wall portion 3 of Example 1. The film portion 2 and the weight portion 4 of this example are the same as the film portion 2 and the weight portion 4 of Example 1. The support wall portion 3 of this example is made of an elastic body having a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C and a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C. More specifically, the support wall portion 3 of this example has a dynamic storage modulus (E') of 1.48 MPa and a loss tangent (tanδ) of 0.07 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 1.72 MPa and a loss tangent (tanδ) of 0.12 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 2.00 MPa and a loss tangent (tanδ) of 0.11 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 2.33 MPa and a loss tangent (tanδ) of 0.12 at a frequency of 1000 Hz at 23°C, a durometer A hardness of 30 according to JIS K6253-3, a plate thickness of 1.6 mm, and is made of EPDM with a height in the direction orthogonal to the film portion 2 of 10 mm. However, only the outermost support wall portion 3 has a plate thickness of 0.8 mm, which is half. The surface density of this configuration is 2.52 kg / m 2 It is. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in FIG. 15(C).

[0059] [Example 5] The sound insulation mechanism 1 (not shown) of the sound insulation structure 10 of Example 5 has the same structure as that of Example 1, but has a film portion 2 that is softer than the film portion 2 of Example 1. The support wall portion 3 and the weight portion 4 of this example are the same as the support wall portion 3 and the weight portion 4 of Example 1. The film portion 2 of this example is made of EPDM with a durometer A hardness of 30 according to the same IS K6253-3 as the material of the support wall portion 3 of Example 4, and its shape and dimensions are the same as those of the film portion 2 of Example 1. The areal density of this configuration is 2.83 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this example was obtained in the same manner as in Example 1 and is shown in Fig. 16(A).

[0060] [Example 6] The sound insulation mechanism 1 of the sound insulation structure 10 of Example 6 shown in Fig. 20 has the same structure as that of Example 1, but has a partition 5 that is wider than the partition 5 of Example 1. Fig. 20(A) is a perspective view of the sound insulation mechanism 1, and Fig. 20(B) is a cross-sectional view cut along the line A-A and turned upside down. The film portion 2 and the weight portion 4 of this example are the same as the film portion 2 and the weight portion 4 of Example 1. And the support wall portion 3 itself of this example is the same as the support wall portion 3 of Example 1, but is arranged side by side at a wider interval than in Example 1. As a result, each partition 5 of this example has a square shape of 50 mm × 50 mm, and its area is 2500 mm 2 is. The areal density of this configuration is 1.60 kg / m 2 is. There are 9 partitions 5 in the 200 mm × 200 mm square region (evaluation surface) of the film portion 2. However, only a part of this region is schematically shown in the drawing. The sound insulation performance of the sound insulation mechanism 1 of this example was obtained in the same manner as in Example 1 and is shown in Fig. 16(B).

[0061] [Example 7] The sound insulation mechanism 1 (not shown) of the sound insulation structure 10 of Example 7 has the same structure as that of Example 1, but the weight portion 4 has a cylindrical shape with a diameter of 13 mm and a height (dimension in the direction orthogonal to the film portion 2) of 9 mm. Among this weight portion 4, the spring portion 4a, which is the portion on the side attached to the film portion 2, has a height of 4 mm, and is made of an elastic body having a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less and a loss tangent of 0.01 or more and 0.50 or less in the frequency range of 1 Hz to 1000 Hz at 23°C. More specifically, the spring portion 4a of this example has a dynamic storage modulus of 0.06 MPa and a loss tangent (tanδ) of 0.15 at 23°C and 1 Hz, a dynamic storage modulus (E') of 0.07 MPa and a loss tangent (tanδ) of 0.15 at 23°C and 10 Hz, a dynamic storage modulus (E') of 0.08 MPa and a loss tangent (tanδ) of 0.15 at 23°C and 100 Hz, and a dynamic storage modulus (E') of 0.10 MPa and a loss tangent (tanδ) of 0.15 at 23°C and 1000 Hz, and is made of polyurethane foam. The mass portion 4b, which is the portion of the weight portion 4 on the side opposite to the side attached to the film portion 2, has a height of 5 mm and is made of EPDM having a durometer A hardness of 65 according to JIS K6253-3. The mass of the weight portion 4 is approximately 1.0 g.

[0062] The film portion 2 and the support wall portion 3 of this example are the same as the film portion 2 and the support wall portion 3 of Example 1. The areal density of this configuration is 3.08 kg / m 2 and is shown in Fig. 16(C) by obtaining the sound insulation performance of the sound insulation mechanism 1 of this example in the same manner as in Example 1.

[0063] [Example 8] The sound insulation mechanism 1 (not shown) of the sound insulation structure 10 of Example 8 has the same structure as the modified example of the first embodiment shown in FIG. 5. The film portion 2 and the support wall portion 3 of this example are the same as the film portion 2 and the support wall portion 3 of Example 1, but the weight portion 4 of this example is composed of a small-diameter cylindrical spring portion 4a and a large-diameter cylindrical mass portion 4b. The spring portion 4a, which is the portion of the weight portion 4 attached to the film portion 2, is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film portion 2) of 3 mm, and is made of the same material as the spring portion 4a of the weight portion 4 in Example 1 (silicone rubber with a durometer A hardness of 10 according to JIS K6253-3). The mass portion 4b, which is the portion of the weight portion 4 on the side opposite to the side attached to the film portion 2, is cylindrical with a diameter of 13 mm and a height of 5 mm, and is made of EPDM with a durometer A hardness of 65 according to JIS K6253-3. The mass of the weight portion 4 is approximately 1.0 g. The areal density of this configuration is 3.13 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in FIGS. 16(C) and 17(A).

[0064] [Example 9] The sound insulation mechanism 1 (not shown) of the sound insulation structure 10 of Example 9 has the same structure as the modified example of the first embodiment shown in FIG. 5. The film portion 2 and the weight portion 4 of this example are the same as the film portion 2 and the weight portion 4 of Example 8, but the support wall portion 3 of this example is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height in the direction perpendicular to the film portion 2 of 10 mm. The areal density of this configuration is 2.81 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in FIGS. 17(A) to 17(C).

[0065] [Example 10] The sound insulation mechanism 1 of the sound insulation structure 10 of Example 10 shown in Fig. 21 has the same structure as the modified example of the first embodiment shown in Fig. 5. Fig. 21 is a cross-sectional view of the sound insulation mechanism 1. The film part 2 and the weight part 4 of this example are the same as those of the film part 2 and the weight part 4 of Example 9, but the support wall part 3 of this example is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height in the direction orthogonal to the film part 2 of 14 mm. The areal density of this configuration is 3.16 kg / m 2 2. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in Fig. 17(B).

[0066] [Example 11] The sound insulation mechanism 1 of the sound insulation structure 10 of Example 11 shown in Fig. 22 has the same structure as the modified example of the first embodiment shown in Fig. 5. Fig. 22(A) is a perspective view of the sound insulation mechanism 1, and Fig. 22(B) is a cross-sectional view taken along the line B-B and turned upside down. The film part 2 and the weight part 4 of this example are the same as those of the film part 2 and the weight part 4 of Example 9, but in this example, among a plurality of support wall parts, some support wall parts 3d extend in the direction orthogonal to the film part 2 with a higher height than the other support wall parts 3c. That is, the sound insulation mechanism 1 of this example has a support wall part (some support wall parts) 3d with a high height similar to the support wall part 3 of Example 10 and a support wall part (other support wall parts) 3c with a low height similar to the support wall part 3 of Example 9. Specifically, the support wall part 3c is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height in the direction orthogonal to the film part 2 of 10 mm, and the support wall part 3d is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height in the direction orthogonal to the film part 2 of 15 mm. The support wall part 3d has a height 1.5 times that of the support wall part 3c. In this example, as shown in Figs. 22(A) and 22(B), rows in which the support wall parts 3d with a high height are arranged and rows in which only the support wall parts 3c with a low height are arranged are alternately positioned. Thereby, among the 49 square sections 5 arranged in a 7×7 grid, 16 sections 5 are sections surrounded by the support wall parts 3d with a high height. The areal density of this configuration is 3.02 kg / m 2It is. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in Fig. 17(C).

[0067] [Example 12] The sound insulation mechanism 1 (not shown) of Example 12 has the same structure as a modification of the first embodiment shown in Fig. 5. The weight portion 4 of this example is the same as the weight portion 4 of Example 8. The film portion 2 and the support wall portion 3 of this example have a dynamic storage modulus (E') of 7.81 MPa and a loss tangent (tanδ) of 0.06 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 8.62 MPa and a loss tangent (tanδ) of 0.08 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 9.19 MPa and a loss tangent (tanδ) of 0.11 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 10.3 MPa and a loss tangent (tanδ) of 0.08 at a frequency of 1000 Hz at 23°C, a durometer A hardness of 50 according to JIS K6253, a thickness of the film portion 2 of 1.0 mm, a plate thickness of the support wall portion 3 of 1.2 mm, and a height in the direction orthogonal to the film portion 2 of 10 mm, and is formed by integral molding of a styrene-based thermoplastic elastomer (TPS). The areal density of this configuration is 2.56 kg / m 2 It is. The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in Fig. 18(A).

[0068] [Example 13] The sound insulation mechanism 1 (not shown) of Example 13 has the same structure as the modified example of the first embodiment shown in FIG. 5. The film part 2 and the support wall part 3 of this example are the same as the film part 2 and the support wall part 3 of Example 12. The weight part 4 of this example consists of a spring part 4a having a small-diameter cylindrical shape and a mass part 4b having a large-diameter cylindrical shape. The spring part 4a, which is the part of the weight part 4 on the side attached to the film part 2, is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film part 2) of 3 mm. At 23°C, the dynamic storage modulus (E’) at a frequency of 1 Hz is 0.19 MPa, the loss tangent (tanδ) is 0.03. At 23°C, the dynamic storage modulus (E’) at a frequency of 10 Hz is 0.19 MPa, the loss tangent (tanδ) is 0.04. At 23°C, the dynamic storage modulus (E’) at a frequency of 100 Hz is 0.19 MPa, the loss tangent (tanδ) is 0.25. At 23°C, the dynamic storage modulus (E’) at a frequency of 1000 Hz is 0.23 MPa, the loss tangent (tanδ) is 0.04. It is made of TPS with a Shore A hardness of 5 according to JIS K6253. The mass part 4b, which is the part of the weight part 4 on the side opposite to the side attached to the film part 2, is cylindrical with a diameter of 11 mm and a height of 6 mm. It is made of EPDM with a Shore A hardness of 70 according to JIS K6253-3. The areal density of this configuration is 2.50 kg / m 2 ². The sound insulation performance of the sound insulation mechanism 1 of this example was determined in the same manner as in Example 1 and is shown in FIG. 18(A).

[0069] [Example 14] The sound insulation mechanism 1 (not shown) of Example 13 has the same structure as the modified example of the first embodiment shown in FIG. 5. The film part 2 and the support wall part 3 of this example are the same as the film part 2 and the support wall part 3 of Example 12. The weight part 4 of this example consists of a small-diameter cylindrical spring part 4a and a large-diameter cylindrical mass part 4b. The spring part 4a, which is the part of the weight part 4 attached to the film part 2, is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film part 2) of 3 mm. The mass part 4b, which is the part of the weight part 4 on the side opposite to the side attached to the film part 2, is cylindrical with a diameter of 9 mm and a height of 6 mm. The spring part 4a and the mass part 4b of the weight part 4 of this example have a dynamic storage modulus (E') of 0.21 MPa and a loss tangent (tanδ) of 0.04 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 0.23 MPa and a loss tangent (tanδ) of 0.03 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 0.29 MPa and a loss tangent (tanδ) of 0.05 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 0.25 MPa and a loss tangent (tanδ) of 0.17 at a frequency of 1000 Hz at 23°C, and are made of TPS with a durometer A hardness of 5 according to JIS K6253. The areal density of this configuration is 2.14 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this example was obtained in the same manner as in Example 1 and is shown in FIG. 18(A).

[0070] [Comparative Example 1] As Comparative Example 1, the theoretical value of the sound insulation performance calculated based on the mass law when a member having the same mass as the sound insulation mechanism 1 of the sound insulation structure 10 of Example 1 was placed was obtained, and the relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss is shown in FIG. 15(A). The areal density of this configuration is 2.90 kg / m 2 is.

[0071] [Comparative Example 2] As Comparative Example 2, the sound insulation performance of only the film portion 2 was measured in the same manner as in Example 1, and the relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss is shown in Fig. 15(A). The film portion 2 of this comparative example is the same as the film portion 2 of Example 1, and there are no supporting wall portions 3 and weight portions 4 as in Example 1. The areal density of this configuration is 0.68 kg / m 2 is.

[0072] [Comparative Example 3] As Comparative Example 3, in the same manner as in Example 1, the sound insulation performance of the sound insulation mechanism composed of only the film portion 2 and the supporting wall portion 3 was measured, and the relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss is shown in Figs. 15(A) to 15(B) and 16(C). The film portion 2 and the supporting wall portion 3 of this comparative example are the same as the film portion 2 and the supporting wall portion 3 of Example 1, but there is no weight portion 4. The areal density of this configuration is 2.43 kg / m 2 is.

[0073] [Comparative Example 4] The sound insulation mechanism (not shown) of the sound insulation structure of Comparative Example 4 has substantially the same structure as that of Example 1, but has a supporting wall portion 3 that is harder and less flexible than the supporting wall portion 3 of Example 1. The film portion 2 and the weight portion 4 of this comparative example are the same as the film portion 2 and the weight portion 4 of Example 1. The supporting wall portion 3 of this comparative example is made of polylactic acid (PLA resin) having a dynamic storage modulus (E’) of 2.03 GPa and a loss tangent (tanδ) of 0.0045 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E’) of 2.04 GPa and a loss tangent (tanδ) of 0.000060 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E’) of 2.05 GPa and a loss tangent (tanδ) of 0.045 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E’) of 2.07 GPa and a loss tangent (tanδ) of 0.0079 at a frequency of 1000 Hz at 23°C, and its shape and dimensions are the same as those of the supporting wall portion 3 of Example 1. The areal density of this configuration is 2.63 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this comparative example was determined in the same manner as in Example 1 and is shown in Fig. 15(C).

[0074] [Comparative Example 5] As Comparative Example 5, similar to Comparative Example 3, as shown in FIG. 23, the sound insulation performance of the sound insulation mechanism composed only of the film portion 2 and the support wall portion 3 was measured in the same manner as in Example 1, and the relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss is shown in FIG. 18(A). FIG. 23(A) is a perspective view of this sound insulation mechanism, and FIG. 23(B) is a cross-sectional view cut along the line A-A and inverted vertically. The film portion 2 and the support wall portion 3 of this comparative example are the same as the film portion 2 and the support wall portion 3 of Example 12 and different from the film portion 2 and the support wall portion 3 of Example 1 and Comparative Example 3. And, the weight portion 4 does not exist in the sound insulation mechanism of this comparative example. The areal density of this configuration is 1.88 kg / m 2 is.

[0075] [Comparative Example 6] The sound insulation mechanism 1 (not shown) of Comparative Example 6 has the same structure as that of Example 1, but has a film portion 2 made of a resin material with a thinner film thickness than the film portion 2 of Example 1. The support wall portion 3 and the weight portion 4 of this comparative example are the same as the support wall portion 3 and the weight portion 4 of Example 1. The film portion 2 of this comparative example is made of low-density polyethylene (LDPE) with a film thickness of 0.05 mm. The areal density of this configuration is 2.25 kg / m 2 is. The sound insulation performance of the sound insulation mechanism 1 of this comparative example was determined in the same manner as in Example 1 and is shown in FIG. 18(B).

[0076] [Results] The results of comparing Examples 1 to 14 and Comparative Examples 1 to 6 of the present invention described above will be described. Referring to FIG. 15(A), it can be seen that the sound insulation effect is improved by the sound insulation mechanisms 1 and 6 of the sound insulation structure 10 of the present invention. In particular, according to the sound insulation mechanism 1 of Example 1, in the frequency band higher than 630 Hz, a significantly greater sound insulation effect than the theoretical value (Comparative Example 1) based on the mass law is obtained, indicating that the effect of the present invention is significant. And, in particular, when compared with Comparative Example 2 and Comparative Example 3 in the frequency band lower than 1.25 kHz, it can be seen that the sound insulation performance of Example 1 having the film portion 2, the support wall portion 3, and the weight portion 4 is high.

[0077] Referring to Fig. 15(B), it can be seen that a favorable sound insulation effect can be obtained in the same manner for both the sound insulation mechanism 1 (Example 1) of the first embodiment of the present invention and the sound insulation mechanism 6 (Examples 2 and 3) of the second embodiment. When the weight portion 4 itself constitutes a spring mass resonator as in Example 1, particularly good sound insulation is obtained in the vicinity of the frequency (for example, 630 Hz to 1000 Hz) at which the vibration of the film portion 2 is reduced by the resonance of the spring mass resonator. On the other hand, when the spring mass resonator is constituted by the weight portion 7 and the film portion 2 as in Examples 2 and 3, the frequency band with particularly good sound insulation can be adjusted according to the weight of the weight portion 7. For example, when the weight portion 7 has the same mass as the weight portion 4 of Example 1, the frequency band with particularly good sound insulation is around 1000 Hz. When the weight portion 7 is made lighter, the frequency band with particularly good sound insulation can be shifted to the high frequency side.

[0078] Referring to Fig. 15(C), it can be seen that the sound insulation performance is low unless the support wall portion 3 of the sound insulation mechanism is made of a flexible material, but a favorable sound insulation effect can be obtained when the support wall portion 3 is made of a flexible material. This is presumably because when the support wall portion 3 is hard rather than made of a flexible material, vibration is likely to be transmitted to the film portion 2 through the support wall portion 3, whereas when the support wall portion 3 is made of a flexible material, vibration is less likely to be transmitted to the film portion 2 through the support wall portion 3. The frequency band with particularly good sound insulation can be adjusted according to the hardness of the support wall portion 3. For example, when the support wall portion 3 is made softer, the frequency band with particularly good sound insulation can be shifted to the low frequency side.

[0079] Referring to Fig. 16(A), it can be seen that the sound insulation performance slightly decreases when the film portion 2 of the sound insulation mechanism is too soft. This is presumably because when the film portion 2 is too soft, vibration sufficient for the spring mass resonator to function properly is not transmitted to the spring mass resonator.

[0080] Referring to Fig. 16(B), it can be seen that if each section 5 of the film portion 2 defined by the support wall portion 3 of the sound insulation mechanism is too large, the sound insulation performance will slightly decrease. This is presumably because if each section 5 is too large, the spring mass resonator does not function sufficiently and the vibration reduction effect weakens. Therefore, it is preferable that each section 5 is somewhat small (for example, 1000 mm 2 or less).

[0081] Referring to Fig. 16(C), it is shown that even if the materials and shapes of the weight portions 4 of the sound insulation mechanism 1 are different, as long as each is within a preferable range of materials and shapes, the sound insulation function in the present invention is exhibited. Therefore, it can be understood that the materials and shapes of the weight portion 4 and the like can be freely set within a preferable range.

[0082] Referring to Fig. 17(A), it can be seen that even if the durometer A hardness of the support wall portion 3 according to JIS K6253-3 is somewhat different, a similar sound insulation effect can be obtained. And referring to Fig. 17(B), it can be seen that even if the height extending in the direction orthogonal to the film portion 2 of the support wall portion 3 is somewhat different, a similar sound insulation effect can be obtained.

[0083] Referring to Fig. 17(C), it can be seen that even in a configuration where only some of the support wall portions 3d of the plurality of support wall portions have a higher height extending in the direction orthogonal to the film portion 2 and the heights of the other support wall portions 3c are lower, a good sound insulation effect can be obtained. When the sound source and the sound insulation mechanisms 1 and 6 are mounted and supported on external members (not shown), if there are too few support wall portions 3d with a high height, it becomes difficult to stably support the sound insulation mechanisms 1 and 6, and if there are too many, the weight of the entire sound insulation mechanisms 1 and 6 increases. Therefore, it is preferable that the section 5 surrounded by the support wall portions 3d with a high height is 5% or more of the total sections 5 of the sound insulation mechanisms 1 and 6. Also, when looking at the cross section parallel to the film 2 of each support wall portion 3c and 3d, it is preferable that the total cross-sectional area of the support wall portions 3d with a high height is 10% or more of the total cross-sectional area of all the support wall portions 3c and 3d of the sound insulation mechanisms 1 and 6. In Example 11, among the film portions 2 having a square planar shape of 25 mm × 25 mm, 20 mm × 20 mm (area 400 cm 2In the region of , 49 compartments 5 are provided in a 7×7 arrangement. Among them, 16 compartments 5 are surrounded by the high support wall portions 3d, and the ratio is 32.6%, which is preferable.

[0084] Note that, whether all the support wall portions 3 have a high height as in Example 10 or only some of the support wall portions 3d have a high height as in Example 11, in order to suppress an increase in the weight of the entire sound insulation mechanism 1, 6 and installation restrictions, it is preferable that the height of the entire sound insulation mechanism 1, 6 be 20 mm or less as described above.

[0085] Referring to FIG. 18(A), it can be seen that even when the film portion 2 and the support wall portion 3 are formed by integrally molding a thermoplastic material, good sound insulation can be obtained by providing the weight portion 4. In the spring-mass resonator composed of the spring portion 4a and the mass portion (mass part) 4b of the weight portion 4 as in Example 13, it can be seen that when the spring portion 4a is softer, the resonance frequency shifts to the low-frequency side, and a large sound insulation effect can be obtained on the low-frequency side. By thus changing the configuration of the weight portion 4, adjustment of the sound insulation frequency band is possible. Also, as in Example 14, it can be seen that good sound insulation can be obtained even when the weight portion 4 has a configuration made of a single material. Therefore, productivity can be improved by manufacturing the weight portion 4 from a single material.

[0086] Referring to FIG. 18(B), it can be seen that when the film portion 2 is made of a thin resin material (film), the sound insulation performance deteriorates, so it is preferable that the film portion 2 has a certain thickness. Compared with an elastomer material such as the EPDM of Example 1, the resin material such as LDPE of Comparative Example 6 is hard, so it is conceivable to reduce the film thickness. However, without a film thickness of a certain level or more, the film portion 2 is too soft, and it is considered that vibrations sufficient for the spring-mass resonator composed of the spring portion 4a and the mass portion (mass part) 4b of the weight portion 4 to function properly are not transmitted to the weight portion 4. Therefore, it is preferable that the film portion 2 has a thickness of a certain level or more.

[0087] The present invention may have the following configuration. [1] A sound insulation structure having an enclosure that at least partially covers a sound source or a space isolated from the sound source from the side, wherein at least a part of the inner-facing surface of the enclosure has a sound insulation mechanism, the sound insulation mechanism includes an elastic membrane portion, a support wall portion that stands on the membrane portion and has elasticity, and a weight portion that stands on the membrane portion, the membrane portion is divided into a plurality of compartments by the support wall portion, and the weight portions are respectively located inside all of the plurality of compartments or inside some of the plurality of compartments. In the compartments where the weight portions are located inside, one weight portion is arranged in one compartment, the height of the support wall portion extending in the direction perpendicular to the membrane portion is greater than the height of the weight portion extending in the direction perpendicular to the membrane portion, A sound insulation structure, characterized in that each of the weight portions constitutes a spring mass resonator having an elastic spring portion and a mass portion having a mass greater than that of the spring portion. [2] The sound insulation structure according to [1], wherein each of the membrane portion, the support wall portion, and the spring portion is made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity. [3] The sound insulation structure according to [1] or [2], wherein each of the membrane portion, the support wall portion, and the spring portion has a dynamic storage modulus of elasticity of 0.01 MPa or more and 100 MPa or less at 23°C and a frequency of 1 Hz to 1000 Hz. [4] The sound insulation structure according to any one of [1] to [3], wherein each of the membrane portion, the support wall portion, and the spring portion has a loss tangent of 0.01 or more and 0.50 or less at 23°C and a frequency of 1 Hz to 1000 Hz. [5] The sound insulation structure according to any one of [1] to [4], wherein the spring portion of the weight portion is located on the side attached to the membrane portion of the weight portion, and the mass portion is located on the side opposite to the side attached to the membrane portion of the weight portion. [6] The sound insulation structure according to any one of [1] to [5], wherein the mass portion of the hammer portion has a larger volume than the spring portion. [7] The sound insulation structure according to any one of [1] to [6], wherein the mass portion of the hammer portion is made of a material having a higher density than the spring portion. [8] A sound insulation structure having an enclosure portion that at least partially covers a sound source or a space to be isolated from the sound source from the side, wherein at least a part of the inner surface of the enclosure portion facing inward has a sound insulation mechanism, the sound insulation mechanism includes an elastic film portion, a support wall portion that stands on the film portion and has elasticity, and a hammer portion that stands on the film portion, the film portion is divided into a plurality of compartments by the support wall portion, and the hammer portions are respectively located inside all of the plurality of compartments or inside some of the plurality of compartments. In the compartment where the hammer portion is located inside, one hammer portion is arranged in one compartment, the height of the support wall portion extending in a direction orthogonal to the film portion is greater than the height of the hammer portion extending in a direction orthogonal to the film portion, The sound insulation structure, characterized in that the film portion serves as a spring portion and the hammer portion serves as a mass portion to constitute a spring-mass resonator. [9] The sound insulation structure according to [8], wherein both the film portion and the support wall portion are made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

[10] The sound insulation structure according to [8] or [9], wherein both the film portion and the support wall portion have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C.

[11] The sound insulation structure according to any one of [8] to

[10] , wherein both the film portion and the support wall portion have a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C.

[12] The surrounding portion includes a side plate portion that at least partially covers the sound source or the space from the side, and a top plate portion that at least partially covers the sound source or the space from above, and is the sound insulation structure according to any one of [1] to

[11] .

[13] A part of the side plate portion constitutes an openable and closable door portion, and is the sound insulation structure according to

[12] .

[14] Four or more of the partitions are provided on the top plate portion and the side plate portion respectively, and the partitions are arranged in a matrix, and is the sound insulation structure according to

[12] or

[13] .

[15] The support wall portion includes a plurality of first wall portions that extend in a direction perpendicular to the film portion and extend in a first direction parallel to the film portion, and a plurality of second wall portions that extend in a direction perpendicular to the film portion and extend in a second direction perpendicular to the first direction, and is the sound insulation structure according to any one of [1] to

[14] .

[16] The support wall portion is a cylindrical shape having a circular, elliptical or oval cross-sectional shape defining each of the partitions, or a rectangular tube shape having a polygonal cross-sectional shape defining each of the partitions, and is the sound insulation structure according to any one of [1] to

[15] .

[17] The area of each of the partitions is 100 mm 2 or more and 1000 mm 2 or less, and is the sound insulation structure according to any one of [1] to

[16] .

[18] 10 or more and 1000 or less of the partitions are provided per 1000 cm of the area of the film portion, and is the sound insulation structure according to any one of [1] to

[17] . 2

[19] 50 or more and 500 or less of the partitions are provided per 1000 cm of the area of the film portion, and is the sound insulation structure according to

[18] . 2

[20] The plate thickness of the support wall portion is 0.5 mm or more and 5.0 mm or less, and is the sound insulation structure according to any one of [1] to

[19] .

[21] The plate thickness of the support wall portion is 1.0 mm or more and 3.0 mm or less, and is the sound insulation structure according to

[20] .

[22] The film thickness of the film portion is 0.1 mm or more and 3.0 mm or less, and is the sound insulation structure according to any one of [1] to

[21] .

[23] The sound insulation structure according to any one of [1] to

[22] , wherein the height in the direction orthogonal to the film portion is 5 mm or more and 20 mm or less.

[24] The sound insulation structure according to any one of [1] to

[23] , wherein the height of the support wall portion extending in the direction orthogonal to the film portion is 5 mm or more and 20 mm or less.

[25] The sound insulation structure according to any one of [1] to

[24] , wherein the height of the weight portion extending in the direction orthogonal to the film portion is 1 mm or more.

[26] The sound insulation structure according to any one of [1] to

[25] , wherein the durometer A hardness of the film portion is 50 or more, and the durometer A hardness of the support wall portion is 1 or more and 90 or less.

Explanation of Signs

[0088] 1,6 Sound insulation mechanism 2 Film portion 3 Support wall portion 3a First wall portion 3b Second wall portion 4,7 Weight portion 4a Spring portion 4b Mass portion 5 Compartment 10 Sound insulation structure 11 Surrounding portion 11a Top plate portion 11b Side plate portion 12 Sound source 13 Installation surface 21 Engine 22 Generator 23 Compressor 24 Ventilation fan 25 Workbench 26 Conference table

Claims

1. A sound insulation structure having an enclosure portion that at least partially covers a sound source or a space isolated from the sound source from the side, wherein at least a part of the inner surface of the enclosure portion has a sound insulation mechanism, the sound insulation mechanism having an elastic film portion, a support wall portion standing on the film portion and having elasticity, and a weight portion standing on the film portion, the film portion being divided into a plurality of compartments by the support wall portion, and the weight portions being respectively located inside all of the plurality of compartments or inside some of the plurality of compartments, and in the compartments where the weight portions are located inside, one weight portion is arranged in one compartment, the height of the support wall portion extending in a direction orthogonal to the film portion is greater than the height of the weight portion extending in a direction orthogonal to the film portion, A sound insulation structure, characterized in that each of the weight portions constitutes a spring mass resonator having an elastic spring portion and a mass portion having a mass greater than that of the spring portion.

2. The sound insulation structure according to claim 1, wherein each of the film portion, the support wall portion, and the spring portion is made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

3. The sound insulation structure according to claim 1 or 2, wherein each of the film portion, the support wall portion, and the spring portion has a dynamic storage elastic modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C.

4. The sound insulation structure according to claim 3, wherein each of the film portion, the support wall portion, and the spring portion has a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23°C.

5. The sound insulation structure according to claim 1 or 2, wherein the spring portion of the weight portion is located on the side attached to the film portion of the weight portion, and the mass portion is located on the side opposite to the side attached to the film portion of the weight portion.

6. The sound insulation structure according to claim 5, wherein the mass portion of the weight portion has a larger volume than the spring portion.

7. The sound insulation structure according to claim 1 or 2, wherein the mass portion of the weight portion is made of a material having a density greater than that of the spring portion.

8. A sound insulation structure having an enclosure portion that at least partially covers a sound source or a space isolated from the sound source from the side, At least a part of the inner-facing surface of the surrounding portion has a sound insulation mechanism. The sound insulation mechanism includes an elastic film portion, a support wall portion that stands on the film portion and has elasticity, and a weight portion that stands on the film portion. The film portion is divided into a plurality of compartments by the support wall portion, and the weight portions are respectively located inside all of the plurality of compartments or inside some of the plurality of compartments. In the compartments where the weight portions are located, one weight portion is arranged in one compartment. The height of the support wall portion extending in the direction perpendicular to the film portion is greater than the height of the weight portion extending in the direction perpendicular to the film portion. A sound insulation structure, characterized in that the film portion constitutes a spring-mass resonator as a spring portion and the weight portion constitutes a mass portion.

9. The sound insulation structure according to claim 8, wherein both the film portion and the support wall portion are made of any one of a material having no energy elasticity but having rubber elasticity, a material having no rubber elasticity but having energy elasticity, and a material having both rubber elasticity and energy elasticity.

10. The sound insulation structure according to claim 8 or 9, wherein both the film portion and the support wall portion have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at 23°C and a frequency of 1 Hz to 1000 Hz.

11. The sound insulation structure according to claim 10, wherein both the film portion and the support wall portion have a loss tangent of 0.01 or more and 0.50 or less at 23°C and a frequency of 1 Hz to 1000 Hz.

12. The sound insulation structure according to claim 1 or 8, wherein the surrounding portion includes a side plate portion that at least partially covers the sound source or the space from the side, and a top plate portion that at least partially covers the sound source or the space from above.

13. The sound insulation structure according to claim 12, wherein a part of the side plate portion constitutes an openable and closable door portion.

14. The sound insulation structure according to claim 12, wherein four or more of the compartments are provided in each of the top plate portion and the side plate portion, and the compartments are arranged in a matrix.

Images