Sound insulation structure

Abstract

To provide a thin and light-weight sound insulation structure with a sufficient sound insulation property, capable of being easily mounted on a curved mounting surface in a stable manner.SOLUTION: A sound insulation structure 1 comprises: a film part 2 having elasticity; a support wall part 3 having elasticity, erected on the film part 2; and a weight part 4 erected on the film part 2. The film part 2 is divided into a plurality of sections 5 by the support wall part 3, and the weight part 4 is disposed respectively inside the sections 5. One weight part 4 is provided in one section 5. A height H1 of the support wall part 3, extending in a direction orthogonal to the film part 2 is greater than a height H2 of the weight part 4, extending in the direction orthogonal to the film part 2. Each weight part 4 constitutes a spring-mass resonator having a spring part 4a having elasticity and a mass part 4b having a greater mass than the spring part 4a. At least a portion of the support wall part 3 has a tapered shape that becomes tapered towards a tip part opposite the film part 2.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 in 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 in order to block wind noise and engine noise and 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, members with high sound insulation performance are required. In recent years, in buildings, lightweight sound insulation members have been demanded due to high-rise construction and the like, and also in vehicles, lightweight sound insulation members have been demanded 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 weights are 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, and 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 partition a certain space into certain regions, and vibrators configured at the corner portions of each region partitioned by the frame and having respective natural frequencies to block vibrations transmitted from the vehicle body through the frame.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] 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. Also, 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 held stably. In particular, since panels of general vehicles (e.g., automobiles) often have curved or irregular parts, it is difficult to use them simply as a sound insulation material for vehicles. Further, the rigid frame has a large mass, and an increase in mass due to the sound insulation material may be a problem in some cases.

[0009] The sound insulation material described in Patent Document 2 has a high support portion height, that is, a height extending in a direction orthogonal to the sheet from the sheet, preferably 25 mm or more. In order to stably support the sheet by such a high support portion, the support portion preferably has rigidity. As a result, since vibrations are transmitted through the support portion, there is a possibility that sufficient sound insulation cannot be obtained, 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). Also, such a high support portion causes the sound insulation material to increase in size and weight. When mounted on a panel of a vehicle or the like, there is a concern that the sound insulation material occupies a large space inside the vehicle, reducing the space efficiency and interfering with the installation of other members, or disturbing the occupants.

[0010] 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 comes into contact with this resonance portion, the sound insulation performance may decrease or change. Therefore, it is necessary to provide a large space around the resonance portion, resulting in a decrease in space efficiency.

[0011] 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 the human body comes into contact with these vibrators, 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).

[0012] Therefore, an object of the present invention is to provide a thin and lightweight sound insulation structure that can obtain sufficient sound insulation performance and can be easily and stably placed on a curved or uneven mounting surface such as a panel of a building, a mechanical device, or a vehicle (e.g., an automobile), and particularly has good sound insulation performance in the low frequency region of 1000 Hz or less.

Means for Solving the Problems

[0013] The sound insulation structure of the present invention 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 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 larger than the height of the weight portion extending in the direction perpendicular to the film portion. 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. At least a part of the support wall portion has a tapered shape that becomes thinner toward the tip on the side opposite to the film portion. Note that the elasticity mentioned here refers to 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). Here, 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 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, and the dynamic storage modulus (E') at a frequency of 1 Hz to 1000 Hz at 23°C is 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 at a frequency of 1 Hz to 1000 Hz at 23°C and a loss tangent of 0.05 or more and 0.45 or less at a frequency of 1 Hz to 1000 Hz at 23°C. 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 hammer portion may be made of a material having a higher density than that of the spring portion.

[0014] Another sound insulation structure of the present invention includes an elastic film portion, a support wall portion standing on the film portion and having elasticity, and a hammer portion standing 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, one hammer portion is arranged in one compartment. The height of the support wall portion extending in the direction perpendicular to the film portion is larger than the height of the hammer portion extending in the direction perpendicular to the film portion. The film portion serves as a spring portion, and the hammer portion serves as a mass portion to form a spring-mass resonator. At least a part of the support wall portion has a tapered shape that becomes thinner toward the tip portion on the side opposite to the film portion. 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 of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C. Also, both the film portion and the support wall portion may 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. More preferably, both the film portion and the support wall portion are made of an elastic body having 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 of 0.05 or more and 0.45 or less at a frequency of 1 Hz to 1000 Hz at 23°C.

[0015] The sound insulation structure of the present invention and another sound insulation structure described above may have the following configuration. The thickness of the tip portion on the side opposite to the film portion may be thinner than the thickness of the position of the support wall portion in contact with the film portion. The thickness of the support wall portion may be thinnest at the tip portion on the side opposite to the film portion. The angle formed by at least one surface of the support wall portion with respect to the direction perpendicular to the film portion may be 0.1 degrees or more. The support wall portion may include a plurality of first wall portions extending in a first direction parallel to the film portion while extending in a direction perpendicular to the film portion, and a plurality of second wall portions extending in a second direction perpendicular to the first direction while extending in a direction perpendicular to the film portion. The support wall portion may be cylindrical having a circular, elliptical or oval cross-sectional shape defining each of the compartments, or may be a square tube having 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 is 100 mm 2 or more and 1000 mm 2 or less. 10 or more and 1000 or less of the compartments may be provided per 1000 cm 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. 2 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 in accordance with JIS K 6253-3.

Advantages of the Invention

[0016] According to the present invention, there is provided a thin and lightweight sound insulation structure that can obtain sufficient sound insulation performance and can be easily and stably placed on a curved or uneven mounting surface such as a panel of a building, a mechanical device, or a vehicle (e.g., an automobile). In particular, a sound insulation structure having good sound insulation performance in a low frequency region of 1000 Hz or less can be provided.

Brief Description of the Drawings

[0017]

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[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] FIG. 1(A) is a perspective view of a sound insulation structure 1 according to a first embodiment of the present invention, and FIG. 1(B) is a cross-sectional view taken along line A-A of FIG. 1(A) and turned upside down. The sound insulation structure 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 in which the weight portion 4 is located, one weight portion 4 is located in one compartment 5. FIG. 2(A) is an exploded perspective view of one compartment 5 of the sound insulation structure 1, and FIG. 2(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 portion) 4b having a larger mass than the spring portion 4a. The elasticity referred to here means the property of a solid substance 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). Here, the case of having at least one of energy elasticity and rubber elasticity (entropy elasticity) is referred to as "having elasticity".

[0019] The support wall portion 3 has a tapered shape (a conical shape) that becomes thinner toward the tip on the side opposite to the film portion 2. The entire support wall portion 3 may have a tapered shape, or at least a part of the support wall portion 3, particularly only the vicinity of the tip on the side opposite to the film portion 2, may have a tapered shape. The thickness (plate thickness) of the tip on the side opposite to the film portion 2 is thinner than the thickness (plate thickness) of the position where the support wall portion 3 contacts the film portion 2, and the support wall portion 3 is thinnest at the tip on the side opposite to the film portion 2. This support wall portion 3 may have a tapered shape with both surfaces inclined, or a configuration in which only one surface is inclined and the other surface extends perpendicular to the film portion 2. The angle formed by the surface of the support wall portion 3 with respect to the direction perpendicular to the film portion 2 is preferably 0.1 degrees or more, and more preferably 0.5 degrees or more. That is, when the support wall portion 3 is a resin molded product, the draft angle from the mold is preferably 0.1 degrees or more, and more preferably 0.5 degrees or more. When the draft angle of the support wall portion 3 is 0.1 degrees or more, the mold release property after molding becomes good. On the other hand, the angle formed by the surface of the support wall portion 3 with respect to the direction perpendicular to the film portion 2 is preferably 10 degrees or less, and more preferably 5 degrees or less. That is, when the support wall portion 3 is a resin molded product, the draft angle from the mold is preferably 10 degrees or less, and more preferably 5 degrees or less. By setting the draft angle in accordance with the height of the support wall portion 3 and the thickness (plate thickness) of the position where the support wall portion 3 contacts the film portion 2 within the range where the draft angle of the support wall portion 3 is 10 degrees or less, the mold release property from the mold after molding can be improved without significantly changing the shape of the resin molded product after molding. And, since the support wall portion 3 has a tapered shape, weight reduction can be achieved. Note that in each drawing, for ease of viewing, the thickness and angle (draft angle) of the tapered shape of the support wall portion 3 may be slightly exaggerated in the illustration.

[0020] The support wall portion 3 of this 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. Both the first wall portion 3a and the second wall portion 3b have a tapered shape as described above. 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. 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. Since the support wall portion 3 is a flexible material, the propagation of solid vibration by the support wall portion 3 is suppressed, and the structure becomes flexible, so that it can be easily and stably placed on a curved or uneven mounting surface such as a panel of a building, a mechanical device, or a vehicle (e.g., an automobile).

[0021] In the present embodiment, the portion of the weight portion 4 attached to the film portion 2 is the spring portion 4a, and the portion on the side opposite to the side attached to the film portion 2 is the mass portion 4b having a larger mass than the spring portion 4a. In the example shown in FIGS. 1 and 2, 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 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.

[0022] According to the sound insulation structure 1 of the present 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 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.

[0023] In the present embodiment, the partition 5 of the sound insulation structure 1 preferably has 10 or more and 1000 or less provided per 1000 cm of the area of the film portion 2, and more preferably 50 or more and 500 or less provided. When there are 10 or more partitions 5 per 1000 cm of the area of the film portion 2, the entire sound insulation structure 1 can be divided into a plurality of partitions 5, and the sound insulation effect can be exhibited for each partition, thereby increasing the sound insulation performance of the entire sound insulation structure 1. Further, when the number of partitions 5 is 1000 or less per 1000 cm of the area of the film portion 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. The area of the planar shape of each partition 5 is 100 mm 2 preferably provided per 1000 cm of the area of the film portion 2, and more preferably 50 or more and 500 or less provided. When there are 10 or more partitions 5 per 1000 cm of the area of the film portion 2, the entire sound insulation structure 1 can be divided into a plurality of partitions 5, and the sound insulation effect can be exhibited for each partition, thereby increasing the sound insulation performance of the entire sound insulation structure 1. Also, when the number of partitions 5 is 1000 or less per 1000 cm of the area of the film portion 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. 2 Since there are 10 or more partitions 5 per 1000 cm of the area of the film portion 2, the entire sound insulation structure 1 can be divided into a plurality of partitions 5, and the sound insulation effect can be exhibited for each partition, thereby increasing the sound insulation performance of the entire sound insulation structure 1. Also, when the number of partitions 5 is 1000 or less per 1000 cm of the area of the film portion 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. 2 Since there are 1000 or less partitions 5 per 1000 cm of the area of the film portion 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. The area of the planar shape of each partition 5 is 100 mm2 Above 1000 mm 2 It is preferably below, 200 mm 2 Above 800 mm 2 It is more preferably below. Since the area of each planar shape of each section 5 is 100 mm 2 or more, it is easy to arrange the weight part 4 inside. On the other hand, since the area is 1000 mm 2 or less, the effect of the weight part 4 on the film part 2 is large, and high sound insulation can be obtained. The height of the entire sound insulation structure 1 in the direction orthogonal to the film part 2 is preferably 5 mm or more and 20 mm or less. Since the height of the entire sound insulation structure 1 is 5 mm or more, the weight part 4 can have a sufficient height as a spring mass resonator, and since the height is 20 mm or less, an increase in the weight of the entire sound insulation structure 1 can be suppressed. In addition, each drawing schematically shows each section 5, the support wall part 3, etc. There may be cases where the number and area of the section 5 and the height of the support wall part 3 are not strictly and accurately shown, or where they are not unified in each drawing. However, it is preferable that the number and area of the section 5 and the height of the support wall part 3 are appropriately designed so as to be within the numerical ranges described above, respectively.

[0024] The film portion 2, the support wall portion 3, and the spring portion 4a of the sound insulation structure 1 of the present embodiment 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') is 0.01 MPa or more at a frequency of 1 Hz to 1000 Hz at 23°C, the sound insulation property 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') is 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23°C, the vibration in the sound insulation target frequency band is good, the sound insulation structure 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 any one 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, and a material having both rubber elasticity and energy elasticity.

[0025] The diaphragm portion 2 is preferably a relatively hard elastic film because the hammer portion 4 is attached thereto. The dynamic storage elastic modulus (E’) of the diaphragm portion 2 is preferably 15 MPa or more, the thickness (film 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 portion 2 is 0.1 mm or more, a sufficient thickness can be ensured, so that handling is easy. Since the thickness of the diaphragm portion 2 is 3.0 mm or less, an increase in the thickness and weight of the entire sound insulation structure 1 is suppressed, and the entire sound insulation structure 1 does not become too hard and has good installability. The material of the diaphragm portion 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 portion 2 within the above range, deterioration of vibration of the diaphragm portion 2 is prevented, and the sound insulation property in the frequency band to be sound-insulated becomes good. And the rigidity (axial rigidity) k of the diaphragm portion 2 is expressed as k = E’ × A / L from the dynamic storage elastic modulus E’, the cross-sectional area A, and the thickness L of the diaphragm portion 2. When the area of the diaphragm portion 2 to be evaluated for rigidity is 1000 cm 2 , the rigidity k is preferably 10 6 N / mm or more and 10 9 N / mm or less, and more preferably 3×10 6 N / mm or more and 10 8 N / mm or less. When the area of the diaphragm portion 2 is 1000 cm 2 and the rigidity is 10 6 N / mm or more, deterioration of vibration of the diaphragm portion 2 can be suppressed, and the sound insulation property in the frequency band to be sound-insulated becomes good. When the area of the diaphragm portion 2 is 1000 cm 2 and the rigidity is 10 9 N / mm or less, the sound insulation structure 1 becomes flexible and has good installability. Further, the bending rigidity K of the diaphragm portion 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 portion 2. When the area of the diaphragm portion 2 to be evaluated is 1000 cm 2 , the bending rigidity K is preferably 1 N / mm 2 or more and 10 5 N / mm 2 or less, and preferably 10 N / mm2 5×10 or more 4 N / mm 2 It is more preferable that the area of ​​the membrane portion 2 is 1000 cm or less. 2 The bending stiffness K when 2 By satisfying the above, the vibration of the film portion 2 is improved, and the deterioration of the sound insulation performance in the frequency band to be sound-insulated can be suppressed. 2 When the bending stiffness K is 10 5 N / mm 2 When the thickness is as follows, the sound insulation structure 1 becomes flexible and the installation becomes easy. The cross-sectional shape of the film portion 2 is not particularly limited, and may be flat or may have irregularities.

[0026] Examples of the material for the diaphragm 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. In addition, 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, fungicides, 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.

[0027] Examples of the thermoplastic elastomer include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, ethylene-vinyl acetate-based thermoplastic elastomers, 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.

[0028] Specifically, the material of the film portion 2 is preferably ethylene-propylene-diene rubber, thermoplastic olefin-based elastomer, thermoplastic styrene-based elastomer, polyethylene, polypropylene, polyethylene terephthalate, thermoplastic polyurethane, or the like.

[0029] 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 structure 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 structure 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 still 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 structure 1 can be maintained. When the durometer A hardness of the support wall portion 3 is 90 or less, vibration from the support wall portion 3 can be prevented from being transmitted to the film portion 2 and deteriorating the sound insulation performance, and the sound insulation structure 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 structure 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 structure 1 is not rigid and has good installability.

[0030] 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.

[0031] 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.

[0032] 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 larger mass than the spring portion 4a, and has a mass of, for example, 0.1 g or more and 2.0 g or less. The mass portion 4b preferably has a mass that is 1.5 times or more the mass of the spring portion 4a. When the weight of the mass portion 4b is 1.5 times or more 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.

[0033] 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.

[0034] 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, the sound-insulating structure 1 of the present embodiment is lightweight and thin, and 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). And the support wall portion 3 made of a flexible material can be easily and stably installed without being fixed to a flat mounting surface, a curved mounting surface, or a mounting surface having irregularities by adhesion or the like.

[0035] FIG. 3(A) is a perspective view of the sound insulation structure 1 according to a modified example of the first embodiment of the present invention, and FIG. 3(B) is a cross-sectional view taken along line A-A of FIG. 3(A) and turned upside down. FIG. 4(A) is a cross-sectional view of the sound insulation structure 1 according to another modified example, and FIG. 4(B) is a perspective view of the weight portion 4 of the sound insulation structure 1. FIG. 5(A) is a cross-sectional view of the sound insulation structure 1 according to still another modified example, and FIG. 5(B) is a perspective view of the weight portion 4 of the sound insulation structure 1. In the modified example shown in FIGS. 3(A) and 3(B), the spring portion 4a is a small-diameter cylindrical shape, and the mass portion 4b is a large-diameter cylindrical shape. In the modified example shown in FIGS. 4(A) and 4(B), the spring portion 4a is an elongated cylindrical shape, the mass portion 4b is 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. 5(A) and 5(B), the spring portion 4a is a frustum of a cone shape, the mass portion 4b is 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. 3(A) to 4(B), 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. 5(A) and 5(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 is a frustum of a cone shape that tapers in a direction away from the film portion 2 as in the modified example shown in FIGS. 5(A) and 5(B), the mold release property from the mold when the film 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. 1 to 5 and various other shapes not shown can be adopted. The weight portion 4 is formed in an arbitrary shape and dimensions selected so as to satisfy the performance of the spring mass resonator required for sound insulation and to be accommodated in the partition 5.

[0036] 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, and a sufficient sound insulation effect is obtained. 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.

[0037] [Second Embodiment] FIG. 6(A) is a perspective view of a sound insulation structure 6 according to the second embodiment of the present invention, and FIG. 6(B) is a cross-sectional view taken along line A-A of FIG. 6(A) and turned upside down. The sound insulation structure 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 from, 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 structure 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 membrane portion 2, and in a specific frequency range (for example, 1000 Hz or less), the membrane vibration is significantly reduced and a high sound insulation property 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.

[0038] In this embodiment, both the film portion 2 and the support wall portion 3 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 portion 2 and the support wall portion 3 in 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.

[0039] In addition, the support wall portion 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 portion 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.

[0040] FIG. 7(A) is a cross-sectional view of the sound insulation structure 6 of the modification of the second embodiment of the present invention, and FIG. 7(B) is a perspective view of the weight portion 7 of the sound insulation structure 6. In this modification, the weight portion 7 is a frustum of a cone that tapers in a direction away from the film portion 2. In this configuration, the mold release property from the mold when the film portion 2 and the weight portion 7 are integrally formed is good. In this embodiment, the shape of the weight portion 7 can be arbitrarily determined and is not particularly limited.

[0041] In any of the first to second embodiments, the film portion 2 and the support wall portion 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. As described above, since the support wall portion 3 has a tapered shape, it has good moldability, and a sound insulation structure can be produced relatively easily by integral molding, two-color molding, insert molding, compression molding, etc. Further, at least a part of the weight portions 4 and 7 may also be formed together with the film portion 2 and the support wall portion 3 by integral molding, two-color molding, insert molding, etc. of the above-described materials. However, the sound insulation structures 1 and 6 may be assembled by separately forming the film portion 2, the support wall portion 3, and the weight portions 4 and 7 and then joining them to each other by adhesion or heat fusion.

[0042] In the configurations of the sound insulation structures 1 and 6 described above, as shown in FIGS. 8(A) and 8(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 a square. In other words, the support wall portion 3 has a square cross-sectional shape that defines each individual partition 5 and is in the form of a square tube, and a large number of square tube-shaped support wall portions 3 are arranged side by side, with the support wall portions 3 of adjacent partitions 5 integrated. However, it is not limited to such a configuration. For example, as shown in FIGS. 9(A) and 9(B), the planar shape of each partition 5 may be triangular, and the support wall portion 3 may have a triangular cross-sectional shape that defines each individual partition 5 and is in the form of a square tube. Also, as shown in FIGS. 10(A) and 10(B), the planar shape of each partition 5 may be pentagonal, and the support wall portion 3 may have a pentagonal cross-sectional shape that defines each individual partition 5 and is in the form of a square tube. As shown in FIGS. 11(A) and 11(B), the planar shape of each partition 5 may be hexagonal, and the support wall portion 3 may have a hexagonal cross-sectional shape that defines each individual partition 5 and constitutes a so-called honeycomb structure. Further, as shown in FIGS. 12(A) and 12(B), the planar shape of each partition 5 may be circular, and the support wall portion 3 may have a circular cross-sectional shape that defines each individual partition 5 and is in the form of a cylinder. In the case of the configurations shown in FIGS. 10 and 12, since a gap is generated between the partitions 5, it is preferable to determine the shape and dimensions of the support wall portion 3 so that the gap becomes smaller. In the case of the configurations shown in FIGS. 8, 9, and 11, no gap is generated between the partitions 5. Furthermore, each partition 5 may have various shapes not shown in the figures, such as a rectangle, a parallelogram, a trapezoid, a polygon with seven or more sides, an ellipse, an oblong, etc., or an irregular shape. The support wall portion 3 is formed in a shape and dimensions that match the planar shape of each partition 5.

[0043] The sound insulation structures 1 and 6 of the present invention are very thin and lightweight, and are also easy to place on a surface having a curved surface or unevenness. Therefore, they may be placed and used on a panel of a vehicle, particularly an automobile. Panels of automobiles and the like are basically plates without air permeability. 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 structures 1 and 6 are placed is a metal plate, its thickness is preferably in the range of 0.5 mm to 2.0 mm. When it is a resin plate, its thickness is preferably in the range of 0.5 mm to 20 mm. When the sound insulation structures 1 and 6 are placed on an automobile panel, it is preferable that the end face of the support wall portion 3 of the sound insulation structures 1 and 6 on the side opposite to the side attached to the film portion 2 is placed on the panel. At this time, the support wall portion 3 and the panel may or may not be adhered. However, it is preferable that the support wall portion 3 is placed and used on the panel without being adhered to the panel.

[0044] Further, the sound insulation structures 1 and 6 of the present invention may be used alone, or may be used in combination with other members (not shown). When the sound insulation structures 1 and 6 of the present invention are used in combination with other members, they may be laminated or joined with other members. When laminated or joined with other members, the sound insulation structures 1 and 6 may be placed so as to be in contact with the portion (for example, an automobile panel) on which the sound insulation structures 1 and 6 are placed, or may be placed so that other members are in contact with that portion. The other members used in combination with the sound insulation structures 1 and 6 may be made of various materials.

[0045] As the parts where the sound insulation structures 1 and 6 of the present invention are installed in a vehicle, 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 structures 1 and 6 of the present invention can also be installed inside the skeleton of the vehicle or between panels, and furthermore, they can also be installed on an under cover under the floor, a fender protector, a back door, a wheel cover, an aerodynamic cover of a suspension, etc. located outside the vehicle.

Example

[0046] Specific examples and comparative examples of the present invention will be described below. [Example 1] The sound insulation structure 1 of Example 1 of the present invention shown in Fig. 13 has the same structure as that of the first embodiment shown in Figs. 1 to 3. Both the film part 2 and the support wall part 3 are made of an elastic body having 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 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, both the film part 2 and the support wall part 3 of this example have a dynamic storage elastic modulus (E') of 7.81 MPa at a frequency of 1 Hz at 23°C, a loss tangent (tanδ) of 0.065, a dynamic storage elastic modulus (E') of 8.62 MPa at a frequency of 10 Hz at 23°C, a loss tangent (tanδ) of 0.079, a dynamic storage elastic modulus (E') of 9.19 MPa at a frequency of 100 Hz at 23°C, a loss tangent (tanδ) of 0.112, a dynamic storage elastic modulus (E') of 10.3 MPa at a frequency of about 1000 Hz at 23°C, a loss tangent (tanδ) of 0.084, and are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A50TPS") with a durometer A hardness of 50 according to JIS K6253. The film part 2 of this example is a flat sheet with a thickness of 1 mm. The support wall part 3 of this example has a tapered shape with a height H1 of 10 mm in the direction perpendicular to the film part 2, a thickness W1 of 1.6 mm at the position in contact with the film part 2, and a thickness W2 of 1.25 mm at the tip on the side opposite to the film part 2. The angle (draft angle) θ formed by both surfaces of the support wall part 3 with respect to the direction perpendicular to the film part 2 is 1 degree. However, only the outermost support wall part 3 has thicknesses of 0.8 mm and 0.625 mm, which are half of W1 and W2 respectively. The interval (pitch) P between the centers of adjacent support wall parts 3 is 25 mm. Therefore, the compartment 5 defined by a plurality of support wall parts 3 (the first wall part 3a and the second wall part 3b) is a square shape with a side length S of 23.4 mm on the surface of the film part 2. For example, when the film part 2 has a square area of 200 mm × 200 mm, there are 49 compartments 5 in that area. However, only a part of this area is schematically shown in the drawing.

[0047] The weight portion 4 of this embodiment consists 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. 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 9 mm and a height of 5 mm. Both the spring portion 4a and the mass portion 4b of the weight portion 4 of this embodiment are made of a material whose dynamic storage modulus at 23°C in the frequency range of 1 Hz to 1000 Hz is 0.01 MPa or more and 100 MPa or less, and whose loss tangent at 23°C in the frequency range of 1 Hz to 1000 Hz is in the range of 0.01 or more and 0.50 or less. More specifically, both the spring portion 4a and the mass portion 4b of the weight portion 4 of this embodiment have a dynamic storage modulus (E’) of 2.13 MPa and a loss tangent (tanδ) of 0.038 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E’) of 2.29 MPa and a loss tangent (tanδ) of 0.031 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E’) of 2.85 MPa and a loss tangent (tanδ) of 0.051 at 23°C and a frequency of 100 Hz, a dynamic storage modulus (E’) of 2.49 MPa and a loss tangent (tanδ) of 0.166 at 23°C and a frequency of about 1000 Hz, and are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A5TPS") with a durometer A hardness of 5 according to JIS K6253. The mass of the weight portion 4 is approximately 0.36 g. The areal density of this sound insulation structure 1 is 2.68 kg / m 2 is. The areal density is a value calculated from the dimensions of the film portion 2, the support wall portion 3, and the weight portion 4 in the section 5, which is the unit structure, and the density of the material of each part. The sound insulation performance of this sound insulation structure 1 was determined. Specifically, using COMSOL Multiphysics (registered trademark), which is general-purpose finite element method software, a model with the sound insulation structure 1 arranged was created, the sound pressure levels on the reflection side and the transmission side were determined, and from the transmission matrix obtained therefrom, the acoustic transmission loss at each frequency for vertically incident sound waves was determined and is shown in FIGS. 14(A) to 14(C) and 15(A) to 15(B). The higher the acoustic transmission loss, the higher the sound insulation performance.

[0048] [Example 2] The sound insulation structure 6 of Example 2 of the present invention shown in FIG. 16 has the same structure as the second embodiment shown in FIG. 6. 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 1. And the weight part 7 is made of A5TPS, and is a columnar shape with a diameter of 9 mm and a height (dimension in the direction perpendicular to the film part 2) of 5 mm. The mass of the weight part 7 is about 0.28 g, and the areal density of this sound insulation structure 6 is 2.56 kg / m 2 2. The other configurations are the same as those of Example 1, so the description is omitted. The sound insulation performance of this sound insulation structure 6 is shown in FIG. 14(A).

[0049] [Example 3] The sound insulation structure 1 of Example 3 of the present invention shown in FIG. 17 has the same structure as Example 1. The film part 2 and the weight part 4 of this example are the same as the film part 2 and the weight part 4 of Example 1. And the support wall part 3 of this example is made of the same material as the support wall part 3 of Example 1, has a height H1 of 10 mm in the direction perpendicular to the film part 2, a thickness W1 of 1.6 mm at the position in contact with the film part 2, and a thickness W2 of 1.43 mm at the tip on the side opposite to the film part 2, and has a tapered shape. The angle (draft angle) θ formed by both surfaces of the support wall part 3 with respect to the direction perpendicular to the film part 2 is 0.5 degrees. However, only the outermost support wall part 3 has thicknesses of 0.8 mm and 0.715 mm, which are each half of W1 and W2. The areal density of this sound insulation structure 1 is 2.75 kg / m 2 2. The other configurations are the same as those of Example 1, so the description is omitted. The sound insulation performance of this sound insulation structure 1 is shown in FIG. 14(B).

[0050] [Example 4] The sound insulation structure 1 of Example 4 shown in Fig. 18 has the same structure as that of Example 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 1. And the support wall part 3 of this example is made of the same material as the support wall part 3 of Example 1, has a height H1 of 10 mm in the direction perpendicular to the film part 2, a thickness W1 of 1.6 mm at the position in contact with the film part 2, and a tapered shape with a thickness W2 of 0.9 mm at the tip on the side opposite to the film part 2. The angle (draft angle) θ formed by both surfaces of the support wall part 3 with respect to the direction perpendicular to the film part 2 is 2 degrees. However, only the outermost support wall part 3 has thicknesses of 0.8 mm and 0.45 mm, which are each half of W1 and W2. The areal density of this sound insulation structure 1 is 2.55 kg / m 2 It is. Since the other configurations are the same as those of Example 1, the description is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 14(B).

[0051] [Example 5] The sound insulation structure 1 of Example 5 of the present invention shown in Fig. 19 has the same structure as that of Example 1. The support wall part 3 and the weight part 4 of this example are the same as those of the support wall part 3 and the weight part 4 of Example 1. And the film part 2 of this example is made of the same material as the film part 2 of Example 1 and has a thickness of 0.5 mm. The areal density of this sound insulation structure 1 is 2.18 kg / m 2 It is. Since the other configurations are the same as those of Example 1, the description is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 14(C).

[0052] [Example 6] The sound insulation structure 1 of Example 6 of the present invention shown in Fig. 20 has the same structure as that of Example 1. The support wall part 3 and the weight part 4 of this example are the same as those of the support wall part 3 and the weight part 4 of Example 1. And the film part 2 of this example is made of the same material as the film part 2 of Example 1 and has a thickness of 1.5 mm. The areal density of this sound insulation structure 1 is 3.18 kg / m 2 It is. Since the other configurations are the same as those of Example 1, the description is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 14(C).

[0053] [Example 7] The sound insulation structure 1 of Example 7 shown in Fig. 21 has the same structure as that of Example 1. 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 1. And the weight part 4 of this example consists of a columnar spring part 4a made of A5TPS with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film part 2) of 3 mm, and a columnar mass part 4b made of A5TPS with a diameter of 6 mm and a height of 5 mm. The mass of the mass part 4b is about 0.13 g, the total mass of the weight part 4 is about 0.2 g, and the areal density of this sound insulation structure 1 is 2.43 kg / m 2 It is as follows. Since the other configurations are the same as those of Example 1, the description thereof is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 15(A).

[0054] [Example 8] The sound insulation structure 1 of Example 8 shown in Fig. 22 has the same structure as that of Example 1. 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 1. And the weight part 4 of this example consists of a columnar spring part 4a made of A5TPS with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film part 2) of 3 mm, and a columnar mass part 4b made of A5TPS with a diameter of 12 mm and a height of 5 mm. The mass of the mass part 4b is about 0.5 g, the total mass of the weight part 4 is about 0.59 g, and the areal density of this sound insulation structure 1 is 3.03 kg / m 2 It is as follows. Since the other configurations are the same as those of Example 1, the description thereof is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 15(A).

[0055] [Example 9] Although not shown, the sound insulation structure 1 of Example 9 of the present invention has the same structure as that of Example 1. The weight part 4 of this example is the same as the weight part 4 of Example 1. And both the film part 2 and the support wall part 3 of this example are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A40TPS") having a dynamic storage modulus (E') of 3.76 MPa, a loss tangent (tanδ) of 0.069 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 4.03 MPa, a loss tangent (tanδ) of 0.082 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 4.43 MPa, a loss tangent (tanδ) of 0.097 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 4.91 MPa, a loss tangent (tanδ) of 0.092 at a frequency of about 1000 Hz at 23°C, and a durometer A hardness of 40 according to JIS K6253. The areal density of this sound insulation structure 1 is 2.47 kg / m 2 It is. Since the other configurations are the same as those of Example 1, the description thereof is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 15(B).

[0056] [Example 10] Although not shown, the sound insulation structure 1 of Example 10 of the present invention has the same structure as that of Example 1. The weight part 4 of this example is the same as the weight part 4 of Example 1. And both the film part 2 and the support wall part 3 of this example are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A60TPS") having a dynamic storage modulus (E') of 14.6 MPa, a loss tangent (tanδ) of 0.067 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E') of 15.8 MPa, a loss tangent (tanδ) of 0.071 at a frequency of 10 Hz at 23°C, a dynamic storage modulus (E') of 17.2 MPa, a loss tangent (tanδ) of 0.12 at a frequency of 100 Hz at 23°C, a dynamic storage modulus (E') of 18.8 MPa, a loss tangent (tanδ) of 0.086 at a frequency of about 1000 Hz at 23°C, and a durometer A hardness of 60 according to JIS K6253. The areal density of this sound insulation structure 1 is 2.47 kg / m 2 It is. Since the other configurations are the same as those of Example 1, the description thereof is omitted. The sound insulation performance of this sound insulation structure 1 is shown in Fig. 15(B).

[0057] [Comparative Example 1] As Comparative Example 1, the theoretical sound insulation value calculated based on the mass law of a member having the same mass as the sound insulation structure 1 of Example 1 was obtained, and the relationship between the frequency and the acoustic transmission loss is shown in Fig. 14(A). The areal density of this configuration is 2.68 kg / m 2 is.

[0058] [Comparative Example 2] As Comparative Example 1, as shown in Fig. 23, the sound insulation property was measured in a state where only the same film part 2 as the film part 2 of Example 1 was present and the support wall part 3 and the weight part 4 were not present, and is shown in Fig. 14(A). The areal density of this configuration, that is, the film part 2, is 1.00 kg / m 2 is.

[0059] [Comparative Example 3] As Comparative Example 3, as shown in Fig. 24, the sound insulation property of the structure 8 having only the same film part 2 and support wall part 3 as the film part 2 and support wall part 3 of Example 1 and not having the weight part 4 was measured, and is shown in Fig. 14(A). The areal density of this structure 8 is 2.11 kg / m 2 is.

[0060] [Comparative Example 4] Although not shown, the structure of Comparative Example 4 has the same structure as that of Example 1. The weight part 4 of this comparative example is the same as the weight part 4 of Example 1. And both the film part 2 and the support wall part 3 of this comparative example are made of polylactic acid (PLA resin) having a dynamic storage modulus (E’) of 2.03 GPa and a loss tangent (tanδ) of 0.0044 at a frequency of 1 Hz at 23°C, a dynamic storage modulus (E’) of 2.04 GPa and a loss tangent (tanδ) of 0.000057 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 about 1000 Hz at 23°C. The areal density of this structure is 3.21 kg / m 2It is as follows. Since the other configurations are the same as those in the first embodiment, the description thereof is omitted. The sound insulation property of this structure is shown in Fig. 15(B).

[0061] [Results] The results of comparing the first to tenth embodiments and the first to fourth comparative examples of the present invention described above will be explained. Referring to Fig. 14(A), it can be seen that good sound insulation effects can be obtained by the sound insulation structures 1 and 6 of the present invention. In particular, according to the sound insulation structures 1 and 6 of the first and second embodiments, in the frequency band of 1 kHz or less, compared with the theoretical value based on the mass law (Comparative Example 1), the configuration of only the film portion 2 without the support wall portion 3 and the weight portion 4 (Comparative Example 2), and the configuration of only the film portion 2 and the support wall portion 3 without the weight portion 4 (Comparative Example 3), significantly greater sound insulation effects can be obtained, indicating that the effects of the present invention are significant.

[0062] Referring to Fig. 14(B), it can be seen that high sound insulation can be obtained even if the angle (draft angle) of the surface of the tapered support wall portion 3 with respect to the direction orthogonal to the film portion varies within a range of 0.1 degrees or more. Therefore, considering the strength, weight, and mold release property of the support wall portion 3, the angle (draft angle) of the tapered shape of the support wall portion 3 can be arbitrarily determined.

[0063] Referring to Fig. 14(C), it can be seen that high sound insulation can be obtained even if the thickness (film thickness) of the film portion 2 varies within a range of 0.1 mm or more and 3.0 mm or less. And by changing the thickness of the film portion 2, it is possible to adjust the frequency showing particularly high sound insulation. Therefore, it is preferable to determine the thickness of the film portion 2 according to the frequency band in which sound insulation is particularly desired.

[0064] Referring to Fig. 15(A), it can be seen that high sound insulation can be obtained even if the size and mass of the mass portion 4b of the weight portion 4 vary to some extent. And by changing the size and mass of the mass portion 4b, it is possible to finely adjust the frequency showing particularly high sound insulation. Therefore, it is preferable to determine the size and mass of the mass portion 4b according to the frequency band in which sound insulation is particularly desired. However, the mass of the mass portion 4b is preferably 1.5 times or more the mass of the spring portion 4a.

[0065] Referring to FIG. 15(B), it can be seen that high sound insulation performance can be obtained even if the hardness of the film portion 2 and the support wall portion 3 is somewhat different. And by changing the hardness of the film portion 2 and the support wall portion 3, it is possible to finely adjust the frequency showing particularly high sound insulation performance. Therefore, it is preferable to determine the hardness of the support wall portion 3 according to the frequency band in which sound insulation is particularly desired. However, among the film portion 2 and the support wall portion 3, especially when the support wall portion 3 is made of a material that is too hard (for example, PLA resin), high sound insulation performance cannot be obtained in the frequency band of at least 1 kHz or less. This is presumably because when the support wall portion 3 is hard, the entire structure becomes hard and resonates at a high frequency as a whole, and vibration is easily propagated to the film portion 2 through the support wall portion 3.

[0066] As described above, it can be seen that the sound insulation structures 1 and 6 of the present invention can obtain high sound insulation performance as long as the materials and shapes of each part are somewhat different and each is within a preferable range of materials and shapes. Therefore, the materials and shapes of each part of the sound insulation structures 1 and 6 can be freely set within a preferable range. Furthermore, since the support wall portion 3 has a tapered shape, weight reduction of the sound insulation structures 1 and 6 is realized.

[0067] The present invention may have the following configuration. [1] It has 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 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 film portion is larger than the height of the weight portion extending in the direction perpendicular to the film portion. 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. The sound insulation structure is characterized in that at least a part of the support wall portion has a tapered shape that becomes thinner toward the tip on the side opposite to the film portion. [2] The sound insulation structure according to [1], wherein each of the film portion, the support wall portion, and the spring portion is made of any one of a material having rubber elasticity but not energy elasticity, a material having energy elasticity but not rubber 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 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 any one of [1] to [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 any one of [1] to [4], 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 any one of [1] to [5], wherein the mass portion of the weight 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 weight portion is made of a material having a higher density than the spring portion. [8] It 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 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 larger than the height of the weight portion extending in the direction perpendicular to the film portion. The film portion serves as a spring portion, and the weight portion serves as a mass portion to constitute a spring-mass resonator. A sound insulation structure, characterized in that at least a part of the support wall portion has a tapered shape that becomes thinner toward the tip portion on the side opposite to the film portion. [9] The sound insulation structure according to [8], wherein both the film portion and the support wall portion are each 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 elastic 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 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 23°C and a frequency of 1 Hz to 1000 Hz.

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

[11] , wherein the thickness of the tip portion on the side opposite to the film portion is thinner than the thickness of the position of the support wall portion in contact with the film portion.

[13] The sound insulation structure according to

[12] , wherein the support wall portion has the thinnest thickness at the tip portion on the side opposite to the film portion.

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

[13] , wherein the angle formed by at least one surface of the support wall portion with respect to the direction orthogonal to the film portion is 0.1 degrees or more.

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

[14] , wherein the support wall portion includes a plurality of first wall portions extending in a direction orthogonal to the film portion and extending in a first direction parallel to the film portion, and a plurality of second wall portions extending in a direction orthogonal to the film portion and extending in a second direction orthogonal to the first direction.

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

[15] , wherein the support wall portion has a cylindrical shape having a circular, elliptical or oval cross-sectional shape defining each of the compartments, or a rectangular tube shape having a polygonal cross-sectional shape defining each of the compartments.

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

[16] as follows.

[18] The number of the partitions is 10 or more and 1000 or less per 1000 cm 2 of the area of the film part, and the sound insulation structure according to any one of [1] to

[17] .

[19] The number of the partitions is 50 or more and 500 or less per 1000 cm 2 of the area of the film part, and the sound insulation structure according to

[18] .

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

[19] .

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

[20] .

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

[21] .

[23] The height in the direction perpendicular to the film part is 5 mm or more and 20 mm or less, and the sound insulation structure according to any one of [1] to

[22] .

[24] The height of the support wall part extending in the direction perpendicular to the film part is 5 mm or more and 20 mm or less, and the sound insulation structure according to any one of [1] to

[23] .

[25] The height of the weight part extending in the direction perpendicular to the film part is 1 mm or more, and the sound insulation structure according to any one of [1] to

[24] .

[26] The Shore A hardness of the film part is 50 or more, and the Shore A hardness of the support wall part is 1 or more and 90 or less, and the sound insulation structure according to any one of [1] to

[25] .

Explanation of Reference Numerals

[0068] 1,6 Sound insulation structure 2 Film part 3 Support wall part 3a First wall part 3b Second wall part 4,7 Weight part 4a Spring part 4b Mass part 5 Partition 8 Structure

Claims

1. It has an elastic film part, a support wall part that stands on the film part and has elasticity, and a weight part that stands on the film part, the film part is divided into a plurality of compartments by the support wall part, and the weight parts are respectively located inside all of the plurality of compartments or inside some of the plurality of compartments. In the compartments where the weight parts are located, one weight part is arranged in one compartment, the height of the support wall part extending in the direction perpendicular to the film part is greater than the height of the weight part extending in the direction perpendicular to the film part, each of the weight parts constitutes a spring mass resonator having an elastic spring part and a mass part having a greater mass than the spring part, A sound insulation structure, characterized in that at least a part of the support wall part has a tapered shape that becomes thinner toward the tip on the side opposite to the film part.

2. The film part, the support wall part, and the spring part are all 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 sound insulation structure according to Claim 1.

3. The film part, the support wall part, and the spring part are all such that the dynamic storage elastic modulus at 23°C in the frequency range of 1 Hz to 1000 Hz is 0.01 MPa or more and 100 MPa or less. The sound insulation structure according to Claim 1 or 2.

4. The film part, the support wall part, and the spring part are all such that the loss tangent at 23°C in the frequency range of 1 Hz to 1000 Hz is 0.01 or more and 0.50 or less. The sound insulation structure according to Claim 3.

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

6. The mass part of the weight part has a larger volume than the spring part. The sound insulation structure according to Claim 5.

7. The mass part of the weight part is made of a material having a higher density than the spring part. The sound insulation structure according to Claim 1 or 2.

8. It has an elastic film part, a support wall part that stands on the film part and has elasticity, and a weight part that stands on the film part, 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 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 greater than the height of the weight portion extending in the direction orthogonal to the film portion. The film portion serves as a spring portion, and the weight portion serves as a mass portion to constitute a spring-mass resonator. A sound insulation structure, characterized in that at least a part of the support wall portion has a tapered shape that becomes thinner toward the tip portion on the side opposite to the film 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 a frequency of 1 Hz to 1000 Hz at 23°C.

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 a frequency of 1 Hz to 1000 Hz at 23°C.

12. The sound insulation structure according to claim 1 or 8, wherein the thickness of the tip portion on the side opposite to the film portion is thinner than the thickness of the position of the support wall portion in contact with the film portion.

13. The sound insulation structure according to claim 12, wherein the thickness is the thinnest at the tip portion on the side opposite to the film portion of the support wall portion.

14. The sound insulation structure according to claim 1 or 8, wherein the angle formed by at least one surface of the support wall portion with respect to the direction orthogonal to the film portion is 0.1 degree or more.

Images