Sound insulation structures and soundproofing structures

Abstract

This invention provides a thin and lightweight sound-insulating structure that offers sufficient sound insulation, can be easily and stably mounted on curved surfaces, and has good sound insulation in the low-frequency range. [Solution] The sound-insulating structure 1 has an elastic membrane portion 2 and a weight portion 4 erected on the membrane portion 2. Each of the weight portions 4 constitutes a spring-mass resonator having an elastic spring portion 4a and a mass portion 4b with a mass greater than that of the spring portion 4a. The durometer A hardness of the membrane portion 2 is 30 or less.

Description

[Technical Field]

[0001] This invention relates to sound insulation structures and soundproofing structures. [Background technology]

[0002] In recent years, the interiors of buildings such as apartment complexes, office buildings, and hotels require quietness appropriate to the room's purpose by blocking out outdoor noise from vehicles, trains, aircraft, ships, etc., as well as equipment noise and human voices generated outside the room. Furthermore, inside vehicles such as cars, trains, aircraft, and ships, it is desirable to reduce noise by blocking wind noise and engine noise to provide a quiet and comfortable space for occupants. Therefore, there is a need for means to block the transmission of noise and vibration from the outside to the inside of buildings and vehicles, and from the outside to the inside of buildings and vehicles—that is, highly sound-insulating materials. In recent years, lightweight sound-insulating materials have been required for buildings due to the increasing height of buildings, and also for vehicles to improve energy efficiency. Examples of sound-insulating structures that form sound barriers in vehicles and buildings are disclosed in Patent Documents 1 to 4.

[0003] The invention described in Patent Document 1 provides an acoustic damping panel comprising a rigid frame divided into a plurality of individual cells, a sheet of flexible material, and a plurality of weights, wherein each weight is fixed to the sheet of flexible material such that each cell has a weight, and the damped sound is controlled by the appropriate selection of the mass of the weights.

[0004] In the invention described in Patent Document 2, a soundproofing material comprising an elastic sheet and a support portion that holds the sheet and divides the sheet into partitioned sections is provided, and the relationship between the rigidity of the sheet in the partitioned section and the surface density of the sheet is defined.

[0005] The sound-insulating material of the invention described in Patent Document 3 is a structure comprising a flat substrate portion and a plurality of resonant portions connected to the substrate portion and having a predetermined resonant frequency, wherein each of the plurality of resonant portions has a weight portion and a connecting portion that connects the weight portion to the substrate portion, and in a projection view taken from a direction perpendicular to the substrate portion, the center of gravity of the resonant portion is located outside the joint area between the substrate portion and the connecting portion.

[0006] The vibration reduction device of the invention described in Patent Document 4 has an acoustic metastructure that is mounted on the vehicle body and blocks vibrations transmitted through the vehicle body, and includes a cross-shaped frame mounted on the vehicle body that divides a certain space into certain regions, and vibrators configured at the corners of each region divided by the frame and configured to have their respective natural frequencies, thereby blocking vibrations transmitted from the vehicle body through the frame. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2005-250474 [Patent Document 2] International Publication No. 2019 / 022245 [Patent Document 3] Japanese Patent Publication No. 2021-152584 [Patent Document 4] Japanese Patent Publication No. 2020-91481 [Overview of the project] [Problems that the invention aims to solve]

[0008] The acoustic damping panel described in Patent Document 1 has a rigid, inflexible frame, and vibrations are transmitted to the sheet through this rigid frame, which may result in insufficient sound insulation. Furthermore, if the mounting surface on which the rigid frame is placed is curved or uneven, the acoustic damping panel may not be able to be held stably. In particular, since panels in typical vehicles (e.g., automobiles) have many curved or uneven parts, it is difficult to simply use the acoustic damping panel of Patent Document 1 as a sound insulation material for vehicles. In addition, the rigid frame has a large mass, and the increase in mass due to the sound insulation material may be a problem in vehicles.

[0009] The soundproofing material described in Patent Document 2 has a high support section, that is, a height extending from the sheet in a direction perpendicular to the sheet, preferably 25 mm or more. In order to stably support the sheet with such a high support section, it is preferable that the support section is rigid, but as a result, vibrations are transmitted through the support section, which may result in insufficient sound insulation, and it is difficult to place it on a curved or uneven surface such as a panel of a vehicle (e.g., an automobile). Furthermore, such a high support section leads to an increase in the overall size and weight of the soundproofing material, and when placed on a panel of a vehicle, the soundproofing material occupies a large space inside the vehicle, reducing space efficiency, and there are concerns that it may hinder the installation of other components or get in the way of occupants.

[0010] The sound-insulating material described in Patent Document 3 has a resonant portion, which is the functional part that provides sound insulation, exposed without being covered by a support wall or the like. If other members or the human body come into contact with this resonant portion, the sound insulation performance may decrease or change. Therefore, it is necessary to provide a large space around the resonant portion, which reduces space efficiency.

[0011] The vibration reduction device described in Patent Document 4 does not have a membrane and consists of multiple vibrators and a frame connecting them. Therefore, similar to the sound insulation material in Patent Document 3, the vibrators, which are the functional parts that provide sound insulation, are exposed, and if these vibrators come into contact with other members or the human body, 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 be rigid. As a result, vibrations are transmitted through the frame, so sufficient sound insulation may not be obtained, and it is difficult to mount the vibration reduction device of Patent Document 4 on curved or uneven surfaces such as panels of vehicles (e.g., automobiles).

[0012] Therefore, the object of the present invention is to provide a thin and lightweight sound-insulating structure that can be easily and stably mounted on curved or uneven surfaces such as panels of buildings, machinery, or vehicles (e.g., automobiles), and which has particularly good sound-insulating properties in the low-frequency range of 500 Hz or less. [Means for solving the problem]

[0013] The first sound-insulating structure of the present invention comprises an elastic membrane portion and a weight portion erected on the membrane portion, wherein each of the weight portions constitutes a spring-mass resonator having an elastic spring portion and a mass portion having a greater mass than the spring portion, and the durometer A hardness of the membrane portion is 30 or less. Here, elasticity refers to the property of a solid material that, after being deformed by an external force, returns to its original shape when the external force is removed. This includes energy elasticity and rubber elasticity (entropy elasticity). In this context, a material is described as "having elasticity" if it possesses at least one of energy elasticity and rubber elasticity (entropy elasticity). It may further have an elastic support wall portion erected on the film portion, the support wall portion surrounds the weight portion from the side in a non-contact manner with respect to the weight portion, and an end portion of the weight portion on the side opposite to the side attached to the film portion is exposed without being covered by the support wall portion. The height of the support wall portion extending in a direction perpendicular to the film portion may be greater than the height of the weight portion extending in a direction perpendicular to the film portion, and the durometer A hardness of the support wall portion may be 30 or less. Any of the film portion, 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. Any of the film portion, the support wall portion, and the spring 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, any of the film portion, the support wall portion, and the spring portion may be made of an elastomer 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 elastomer 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 0.01 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 of the weight portion attached to the film portion, and the mass portion may be located on the side opposite to the side of the weight portion attached to the film 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 density greater than that of the spring portion.

[0014] The second 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 weight portion standing on the film portion. The support wall portion surrounds the weight portion laterally in a non-contact manner, and an end portion of the weight portion opposite to the side attached to the film portion is exposed without being covered by the support wall portion. 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. The film portion serves as a spring portion and the weight portion serves as a mass portion to constitute a spring-mass resonator. Both the film portion and the support wall portion are characterized in that the durometer A hardness is 30 or less. Both the film portion and 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. 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 0.01 or more and 0.45 or less at a frequency of 1 Hz to 1000 Hz at 23°C.

[0015] The first sound insulation structure and the second sound insulation structure may have the following configurations. The membrane portion is divided into a plurality of sections by the support wall portion, and the weight portion is located inside all of the plurality of sections, or inside some of the plurality of sections, and in the sections in which the weight portion is located, one weight portion may be arranged in each section. The support wall portion may include a plurality of first wall portions extending in a direction perpendicular to the membrane portion and in a first direction parallel to the membrane portion, and a plurality of second wall portions extending in a direction perpendicular to the membrane portion and in a second direction perpendicular to the first direction. The membrane portion and the support wall portion may be formed from the same material. The area of ​​each of the aforementioned compartments is 100 mm². 2 Above 1000mm 2 The following is acceptable: Area of ​​the aforementioned membrane: 1000 cm² 2 There may be 10 to 1000 of the aforementioned compartments per unit, and it is more preferable that there be 50 to 500 of the aforementioned compartments. The support wall portion may be cylindrical with a circular, elliptical, or oblong cross-sectional shape defining each of the aforementioned sections, or it may be rectangular tubular with a polygonal cross-sectional shape defining each of the aforementioned sections, specifically a square, regular pentagon, or regular hexagonal cross-sectional shape. The plate thickness of the support wall portion may be 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. The thickness of the aforementioned film portion may be 0.1 mm or more and 3.0 mm or less. The height of the aforementioned membrane portion in the direction perpendicular to it may be 5 mm or more and 20 mm or less. The height of the support wall portion extending in a direction perpendicular to the membrane portion may be 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 may have different heights in parts. The support wall portion may have a plurality of support wall portions, and some of the support wall portions may have a greater height extending in a direction perpendicular to the membrane portion than the other support wall portions. The height of the weight portion extending in a direction perpendicular to the membrane portion may be 1 mm or more.

[0016] The soundproofing structure of the present invention is a soundproofing structure comprising a soundproofing plate-like portion and a sound-insulating structure portion, wherein the soundproofing plate-like portion is a plate-shaped member made of a sound-absorbing material or a sound-insulating material, and the sound-insulating structure portion is made of a sound-insulating structure having one of the above-described configurations, wherein at least one of the membrane portion and the support wall portion and the soundproofing plate-like portion are integrally formed or joined to each other, and the soundproofing plate-like portion and the sound-insulating structure portion are positioned side by side in a planar manner. The soundproof panel may have a single-layer structure consisting of a layer made of felt, polyurethane foam, or glass wool, and a layer made of a resin film or rubber sheet, or a multi-layer structure in which these are laminated. It may be located in at least one of the following locations: the dashboard panel of an automobile, the interior of the instrument panel, the roof, the pillars supporting the roof, the door trim, the fender liners that partially cover the tires, the trunk sides, the trunk trim, and the rear floor. It may also be located inside an electric vehicle. Other soundproofing structures of the present invention consist of a sound-insulating structure having any of the above-described configurations and are placed in at least one of the following locations in an automobile: the dashboard panel, the interior of the instrument panel, the roof, the pillars supporting the roof, the door trim, the fender liner partially covering the tires, the trunk side, the trunk trim, and the rear floor. They may also be placed inside an electric vehicle. [Effects of the Invention]

[0017] According to the present invention, a thin and lightweight sound-insulating structure can be easily and stably mounted on curved or uneven surfaces such as panels of buildings, machinery, or vehicles (e.g., automobiles), and the present invention provides a sound-insulating structure that has particularly good sound-insulating properties in the low-frequency range of 500 Hz or less. [Brief explanation of the drawing]

[0018] [Figure 1](A) is a perspective view of a sound-insulating structure according to the first embodiment of the present invention, and (B) is a cross-sectional view thereof taken along line AA. [Figure 2] (A) is an exploded perspective view of one section of the sound insulation structure shown in Figure 1, and (B) is an exploded front view thereof. [Figure 3] (A) is a perspective view of a sound-insulating structure of a modified example of the first embodiment of the present invention, and (B) is a cross-sectional view thereof taken along line AA. [Figure 4] (A) is a perspective view of a sound insulation structure according to a second embodiment of the present invention, and (B) is a cross-sectional view thereof taken along line AA. [Figure 5] (A) is a schematic plan view showing one section of the sound insulation structure of the present invention, and (B) is a schematic plan view showing multiple sections thereof. [Figure 6] This is a cross-sectional view showing a part of the sound insulation structure of Embodiment 1 of the present invention. [Figure 7] (A) to (B) are graphs showing the sound insulation performance of Examples 1 to 5 and Comparative Examples 1 to 3 of the present invention. [Figure 8] This is a cross-sectional view showing a part of the sound insulation structure of Embodiment 2 of the present invention. [Figure 9] This is a cross-sectional view showing a part of the sound insulation structure of Embodiment 3 of the present invention. [Figure 10] This is a cross-sectional view showing a part of the sound insulation structure of Embodiment 4 of the present invention. [Figure 11] This is a cross-sectional view showing a part of the sound insulation structure of Embodiment 5 of the present invention. [Figure 12] This is a cross-sectional view of the structure of Comparative Example 2. [Figure 13] This is a side view of an automobile equipped with the soundproofing structure of the present invention. [Figure 14] Figure 13 is a side view of the soundproofing structure. [Figure 15] Figure 13 is a perspective view of the soundproofing structure as seen from the front. [Figure 16] Figure 15 is a cross-sectional view along line BB. [Figure 17] This is a side view of another automobile equipped with the soundproofing structure of the present invention. [Figure 18](A) is a perspective view of the automobile shown in Figure 17, seen from the front, and (B) is a perspective view seen from the rear. [Figure 19] Figure 17 is a side view showing a magnified portion of the automobile. [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] Figure 1(A) is a perspective view of a sound insulation structure 1 according to a first embodiment of the present invention, and Figure 1(B) is a cross-sectional view obtained by cutting along line AA of Figure 1(A) and inverting it vertically. Figure 2(A) is an exploded perspective view of one section 5 of the sound insulation structure 1, and Figure 2(B) is an exploded front view thereof. The sound insulation structure 1 has an elastic sheet-like membrane portion 2, an elastic support wall portion 3 erected substantially vertically from the membrane portion 2, and a weight portion 4 erected substantially vertically from the membrane portion 2. The support wall portion 3 surrounds the outer circumferential surface of the weight portion 4 from the side, i.e., from a direction substantially perpendicular to the direction in which the support wall portion 3 and the weight portion 4 extend, without contact with the weight portion 4. The end of the weight portion 4 opposite to the side attached to the membrane portion 2 is exposed and not covered by the support wall portion 3. In other words, the membrane portion 2 is divided into multiple compartments (unit structures) 5 by the support wall portion 3, and a weight portion 4 is located inside all of the multiple compartments 5, or inside some of the multiple compartments 5. In the compartments 5 in which a weight portion 4 is located, one weight portion 4 is located within one compartment 5. The height H1 of the support wall portion 3 extending from the membrane portion 2 in a direction perpendicular to the membrane portion 2 is greater than the height H2 of the weight portion 4 extending from the membrane portion 2 in a direction perpendicular to the membrane portion 2. Each weight portion 4 constitutes a spring-mass resonator having an elastic spring portion 4a and a mass portion (mass part) 4b with a greater mass than the spring portion 4a. Elasticity, as used here, refers to the property of a solid material that has been deformed by an external force to return to its original shape when the external force is removed, and includes energy elasticity and rubber elasticity (entropy elasticity). Here, "having elasticity" refers to a material possessing at least one of energy elasticity and rubber elasticity (entropy elasticity).

[0020] The support wall portion 3 of this embodiment has a tapered shape that narrows towards the tip opposite to the membrane portion 2. The entire support wall portion 3 may be tapered, or at least a part of the support wall portion 3, particularly near the tip opposite to the membrane portion 2, may be tapered. The thickness (plate thickness) of the support wall portion 3 at the position in contact with the membrane portion 2 is less than the thickness (plate thickness) of the tip opposite to the membrane portion 2, and the support wall portion 3 is thinnest at the tip opposite to the membrane portion 2. The support wall portion 3 may have a tapered shape with both surfaces inclined, or it may have a configuration where only one surface is inclined and the other surface extends perpendicularly to the membrane portion 2. The angle that the surface of the support wall portion 3 makes with respect to the direction perpendicular to the membrane 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. If the draft angle of the support wall portion 3 is 0.1 degrees or more, the release properties from the mold after molding will be good. On the other hand, the angle that the surface of the support wall portion 3 makes 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 of the support wall portion 3 to match the height of the support wall portion 3 and the thickness (plate thickness) of the support wall portion 3 at the position where it contacts the film portion 2, within the range of a draft angle of 10 degrees or less, it is possible to improve the release properties from the mold after molding without significantly changing the shape of the resin molded product after molding. Furthermore, the tapered shape of the support wall portion 3 allows for weight reduction. Note that in some drawings, the thickness and angle (draft angle) of the tapered shape of the support wall portion 3 may be slightly exaggerated for clarity. However, although not shown in the diagram, the support wall portion 3 may not be tapered, but rather have a constant thickness (plate thickness) from the point where it contacts the membrane portion 2 to the opposite end, and may extend linearly perpendicular to the membrane portion 2.

[0021] 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 membrane portion 2, and a plurality of second wall portions 3b extending in a second direction D2 perpendicular to the first direction D1, and both the first wall portions 3a and the second wall portions 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, and the first wall portions 3a and the second wall portions 3b are integrated at their intersections. In this way, the plurality of first wall portions 3a and the plurality of second wall portions 3b constitute a lattice structure, and the planar shape partitioned by the first wall portions 3a and the second wall portions 3b is a matrix of a plurality of square sections 5 arranged in a matrix. In other words, the support wall portion 3 is a structure in which a plurality of rectangular tubes having a square cross-sectional shape defining each section 5 are arranged. The support wall portion 3 is preferably made of a flexible material such as rubber, elastomer, or resin foam. The term "flexible material" here refers to any of the following: a material that does not have energy elasticity but has rubber elasticity; a material that does not have rubber elasticity but has energy elasticity; or a material that has both rubber elasticity and energy elasticity. Because the support wall portion 3 is made of a flexible material, the propagation of solid vibrations by the support wall portion 3 is suppressed, and the structure becomes flexible, making it possible to easily and stably place it on curved or uneven mounting surfaces such as panels of buildings, machinery, or vehicles (e.g., automobiles). However, if the membrane portion 2 can be supported by some support means (not shown), the support wall portion 3 can be omitted.

[0022] In this embodiment, the portion of the weight portion 4 attached to the membrane portion 2 is the spring portion 4a, and the portion opposite to the side attached to the membrane portion 2 is the mass portion 4b, which has a greater mass than the spring portion 4a. In the example shown in Figures 1 and 2, the spring portion 4a and the mass portion 4b have the same shape and dimensions, but are made of different materials. The spring portion 4a is made of a flexible material, and the mass portion 4b is made of a material with a higher density than the material that makes up the spring portion 4a. This spring-mass resonator is constructed in which the spring portion 4a functions as a spring and the mass portion 4b functions as a mass. In addition, the membrane portion 2 may also function as part of the spring of the spring-mass resonator together with the spring portion 4a of the weight portion 4. Furthermore, the air in the space surrounded by the membrane portion 2 and the support wall portion 3 may also function as part of the spring of the spring-mass resonator (air spring). It is preferable that the spring portion 4a is also made of a flexible material, that is, a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, or a material that has both rubber elasticity and energy elasticity. While weights 4 may be placed in all sections 5 of the sound-insulating structure 1, it is also possible to have a configuration in which weights 4 are placed in only some sections 5, and some sections 5 do not have weights 4.

[0023] In this embodiment of the sound-insulating structure 1, the vibration of the membrane portion 2 is controlled by the action of a spring-mass resonator formed by the spring portion 4a and mass portion 4b of the weight portion 4. In particular, in a specific frequency range (for example, frequencies below 500 Hz, which are the main frequency ranges for road noise and tire pattern noise in automobiles), membrane vibration is significantly reduced, and as a result, the sound radiated from the membrane portion 2 is reduced, resulting in high sound insulation performance.

[0024] In this embodiment, the sound insulation structure 1 has a section 5 with a membrane section 2 area of ​​1000 cm². 2 It is preferable that 10 to 1000 are provided per unit, and more preferably 50 to 500. Section 5 is the area of ​​the membrane 2, 1000 cm². 2By having 10 or more per area, the entire sound insulation structure 1 can be divided into a plurality of compartments 5, and the sound insulation effect can be exhibited for each compartment, enhancing the sound insulation performance of the entire sound insulation structure 1. Also, since the number of compartments 5 is 1000 or less per 1000 cm of the area of the film part 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. The area of the planar shape of each compartment 5 is preferably 100 mm 2 or more and 1000 mm 2 or less, more preferably 200 mm 2 or more and 800 mm 2 or less. Since the area of the planar shape of each compartment 5 is 100 mm 2 or more, it is easy to arrange the weight part 4 inside, and particularly a large sound insulation performance can be obtained in the low frequency band (for example, a frequency band of 250 Hz or less). 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 performance 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. By having the height of the entire sound insulation structure 1 be 5 mm or more, the weight part 4 can have a sufficient height as a spring mass resonator, and by having the height be 20 mm or less, an increase in the weight of the entire sound insulation structure 1 can be suppressed. Note that each drawing schematically shows the compartments 5, the support wall part 3, etc. There may be cases where the number and area of the compartments 5 and the height of the support wall part 3 are not strictly and accurately shown, or cases where they are not unified in each drawing. However, it is preferably designed appropriately so that the number and area of the compartments 5 and the height of the support wall part 3 are within the numerical ranges described above respectively. 2

[0025] ​The membrane portion 2, support wall portion 3, and spring portion 4a of the sound insulation structure 1 in this embodiment are all made of an elastic material having a dynamic storage modulus (E') of 0.01 MPa to 100 MPa, preferably 0.05 MPa to 50 MPa, at 23°C and a frequency of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 to 0.50, preferably 0.01 to 0.45, at 23°C and a frequency of 1 Hz to 1000 Hz. The dynamic storage modulus (E') and loss tangent (tanδ) are determined by creating a master curve based on 23°C using a dynamic viscoelasticity tester. Since the dynamic storage modulus (E') at 23°C and a frequency of 1 Hz to 1000 Hz is 0.01 MPa or higher, the sound insulation performance in the target frequency band is good, and the shape retention of the membrane portion 2 and support wall portion 3 is good. Since the dynamic storage modulus (E') at 23°C and frequencies from 1Hz to 1000Hz is 100MPa or less, vibrations in the frequency band to be sound-insulated are well controlled, the sound-insulating structure 1 is not rigid, and installation is easy. The membrane portion 2 and the support wall portion 3 may be made of the same material or different materials. Preferably, the membrane portion 2 is made of a flexible material, i.e., a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, or a material that has both rubber elasticity and energy elasticity.

[0026] The thickness (film thickness) of the membrane 2 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 membrane 2 is 0.1 mm or more, sufficient thickness is ensured, making it easy to handle. When the thickness of the membrane 2 is 3.0 mm or less, the increase in the overall thickness and weight of the sound insulation structure 1 is suppressed, and the sound insulation structure 1 does not become too rigid, resulting in good installation. The material of the membrane 2 has a durometer A hardness of 30 or less according to JIS K6253. By having a durometer A hardness of 30 or less of the membrane 2, excellent sound insulation can be achieved in the low frequency range (500 Hz or less, especially 250 Hz or less). The cross-sectional shape of the membrane 2 is not particularly limited and may be flat or uneven.

[0027] Examples of materials for membrane portion 2 include cross-linked (vulcanized) rubber, thermoplastic elastomer, and plastic. Examples of crosslinked (vulcanized) rubbers include ethylene-α-olefin-non-conjugated polyene copolymers such as 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); 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 fluorinated silicone rubber (FVMQ); urethane rubber (U); and fluororubber (FKM), all of which are crosslinked (vulcanized). These crosslinked (vulcanized) rubbers can be used individually or in combination of two or more types. Examples of crosslinking (vulcanization) methods include using organic peroxides, phenolic resins, oxime compounds, sulfur, sulfur-based compounds, and polyamine compounds as crosslinking agents (vulcanizing agents) and crosslinking by heating, or by irradiation with electron beams. The crosslinked (vulcanized) rubbers may also contain various known compounding agents commonly used as rubber compounding agents (such as carbon black, silica, and other reinforcing agents; calcium carbonate and other fillers; paraffin oil, plasticizers and other softening agents; processing aids; antioxidants; light stabilizers; flame retardants; fungicides; acid acceptors; silane coupling agents; antistatic agents; and UV absorbers). These crosslinked (vulcanized) rubbers, crosslinking agents (vulcanizing agents), and compounding agents may also be made from biomass raw materials.

[0028] Examples of thermoplastic elastomers include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, and ethylene-vinyl acetate-based thermoplastic elastomers. Examples of plastics include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, or composite resins containing these materials. These thermoplastic elastomers and plastics may also be made from biomass raw materials.

[0029] Specifically, the material of the membrane portion 2 is preferably ethylene-propylene-diene rubber, thermoplastic olefin elastomer, thermoplastic styrene elastomer, polyethylene, polypropylene, polyethylene terephthalate, thermoplastic polyurethane, etc.

[0030] The support wall portion 3 is preferably made of a soft, flexible material that can support the membrane portion 2. The 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. A thickness of 0.5 mm or more for the support wall portion 3 ensures good shape retention of the sound insulation structure 1. A thickness of 5.0 mm or less for the support wall portion 3 ensures good vibration of the membrane portion 2, resulting in good sound insulation for the frequency band to be sound-insulated and suppressing an increase in the overall weight of the sound insulation structure 1. The height of the support wall portion 3 extending in a direction perpendicular to the membrane portion 2 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 have partially different heights. If the height of the support wall portion 3 is partially different, the taller portion 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. By ensuring that the height of the support wall 3 is not too low, the weight 4 can have sufficient height to function as a spring-mass resonator. By ensuring that the height of the support wall 3 is not too high, the overall weight can be reduced. The material of the support wall 3 is preferably one with a durometer A hardness of 30 or less according to JIS K6253. By ensuring that the durometer A hardness of the support wall 3, together with the membrane 2, is 30 or less, excellent sound insulation can be achieved in the low-frequency range (500 Hz or less, especially 250 Hz or less).

[0031] Examples of materials for the support wall portion 3 include cross-linked (vulcanized) rubber, thermoplastic elastomers, and resin foams. The cross-linked (vulcanized) rubber and thermoplastic elastomers may be the same as the materials listed for the membrane 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, and ethylene-vinyl acetate rubber (EVA) foam. Specifically, the material for 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, or polyurethane foam. These resin foams may also be made from biomass raw materials.

[0032] The material of the spring portion 4a of the weight portion 4 is a flexible material such as cross-linked (vulcanized) rubber, thermoplastic elastomer, or resin foam. The cross-linked (vulcanized) rubber, thermoplastic elastomer, or resin foam may be the same as the materials listed for 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, or polyurethane foam.

[0033] The material of the mass portion 4b is not particularly limited, but it may be made of resin or metal, and the mass portion 4b has a greater mass than the spring portion 4a, for example, a mass of 0.1g or more and 2.0g or less. Preferably, the mass portion 4b has a mass of twice or more the mass of the spring portion 4a. Because the weight of the mass portion 4b is twice 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 deterioration of sound insulation performance is suppressed. If the material of the mass portion 4b is resin, the resin may be made from biomass raw materials.

[0034] The spring constant (stiffness) of the spring section 4a is determined based on the mass of the mass section 4b, such that the resonant frequency matches the frequency that is the main target of sound insulation. For example, if the mass of the mass section 4b is 1.0 g and the frequency that is the main target of sound insulation is 1000 Hz or less, the spring constant of the spring section 4a is between 1 N / mm and 50 N / mm.

[0035] With this configuration, the membrane portion 2, the support wall portion 3, and the weight portion 4 are all relatively lightweight, and the dimensions in the direction perpendicular to the membrane portion 2 are relatively small. Thus, the sound insulation structure 1 of this embodiment is lightweight and thin, yet, as mentioned above, high sound insulation performance is obtained in a specific frequency range (for example, below 500 Hz). Furthermore, the support wall portion 3, which is made of a flexible material, can be easily and stably installed on flat mounting surfaces as well as curved or uneven mounting surfaces without the need for fixing by adhesive or the like. In particular, since the membrane portion 2 and the support wall portion 3 are made of a soft material with a durometer A hardness of 30 or less, they have good installation properties on curved or uneven surfaces, and fixing by adhesive or the like is unnecessary. The installation work of the sound insulation structure 1 is simple and low cost, and removal or replacement for maintenance or other reasons is also extremely easy.

[0036] The specific structure of the sound insulation structure 1 of this embodiment is not limited to the configuration shown in Figures 1 and 2. Modified versions of the sound insulation structure 1 of this embodiment are described below. In the modified versions described below, the spring portion 4a and the mass portion 4b of the weight portion 4 of the sound insulation structure 1 have different shapes and dimensions. Figure 3(A) is a perspective view showing a modified version of the sound insulation structure 1 of this embodiment, and Figure 3(B) is a cross-sectional view obtained by cutting along line AA of Figure 3(A) and inverting it vertically. In the modified version shown in Figure 3, the spring portion 4a is a small-diameter cylindrical shape, and the mass portion 4b is a large-diameter cylindrical shape. Although not shown, the spring portion 4a may also be an elongated cylindrical shape, and the mass portion 4b may be spherical, with the diameter of the cross-sectional shape of the cylindrical spring portion 4a being smaller than the diameter of the spherical mass portion 4b. In these modified versions, 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 made of the same material, the mass portion 4b has a greater mass than the spring portion 4a, and a spring-mass resonator can be constructed. However, in these modified examples, the spring portion 4a and the mass portion 4b may be made of different materials, and the mass portion 4b may have a greater mass than the spring portion. Also, although not shown in the figures, the spring portion 4a may be frustoconical, and the mass portion 4b may be cylindrical, with the diameter of the smallest part of the frustoconical spring portion 4a substantially matching the diameter of the cylindrical mass portion 4b. In this modified example, the spring portion 4a has a larger volume than the mass portion 4b. In this case, the mass portion 4b is made of a material with a higher density than the spring portion 4a, and the mass portion 4b has a greater mass than the spring portion, thereby constructing a spring-mass resonator. As shown in this modified example, if the spring portion 4a is a frustoconical shape that tapers toward the direction away from the membrane portion 2, the release properties from the mold are good when the membrane portion 2 and the spring portion 4a are integrally molded. The shape and dimensions of the weight portion 4 of the present invention are not limited, and shapes such as those shown in Figures 1 to 3, or various other shapes not shown, can be adopted. The weight portion 4 is formed into any shape and dimensions selected so as to satisfy the performance of a spring-mass resonator required for sound insulation and to be housed within the compartment 5.

[0037] In this embodiment, the spring portion 4a and the mass portion 4b of the weight portion 4 are made to differ in material, volume, or both, thereby increasing the mass of the mass portion 4b compared to the spring portion 4a, thereby constructing a spring-mass resonator and obtaining a sufficient sound insulation effect. That is, the material, shape, and dimensions of the spring portion 4a and the mass portion 4b are determined so as to construct a spring-mass resonator that can exhibit a sufficient sound insulation effect. The material, shape, and dimensions of the spring portion 4a and the mass portion 4b can be freely selected as long as the mass of the mass portion 4b is large enough to exceed the mass of the spring portion 4a to construct a spring-mass resonator that can exhibit a sufficient sound insulation effect. However, the spring portion 4a needs to be made of a flexible material in order to function as a spring.

[0038] [Second Embodiment] Figure 4(A) is a perspective view of a sound insulation structure 6 according to a second embodiment of the present invention, and Figure 4(B) is a cross-sectional view obtained by cutting along line AA of Figure 4(A) and inverting it vertically. The sound insulation structure 6 has a single-structure weight portion 7 that is not divided into a spring portion and a mass portion. In this embodiment, a spring-mass resonator is configured in which the entire weight portion 7 functions as the mass portion and the membrane portion 2 functions as the spring portion. For example, the mass of the weight portion 7 is about 0.1g to 2.0g. The material of the weight portion 7 is not limited and is formed from, for example, synthetic resin or metal. The other configurations are the same as those of the first embodiment described above, so their explanation is omitted. In the sound insulation structure 6 of this embodiment as well, membrane vibration is controlled by the action of the spring-mass resonator formed by the weight portion 7 and the membrane portion 2, and membrane vibration is greatly reduced in the low frequency range (for example, below 500Hz, especially below 250Hz), and high sound insulation performance is achieved. In addition, the air in the space surrounded by the membrane 2 and the support wall 3 may also function as part of the spring (air spring) of the spring-mass resonator.

[0039] In this embodiment, both the membrane portion 2 and the support wall portion 3 preferably have a dynamic storage modulus (E') of 0.01 MPa to 100 MPa at 23°C and frequencies from 1 Hz to 1000 Hz, and more preferably 0.05 MPa to 50 MPa. Furthermore, the loss tangent (tanδ) at 23°C and frequencies from 1 Hz to 1000 Hz preferably has a loss tangent of 0.01 to 0.50, and more preferably 0.01 to 0.45. In addition, both the membrane portion 2 and the support wall portion 3 have a durometer A hardness of 30 or less according to JIS K6253.

[0040] Furthermore, the support wall portion 3 of this embodiment is made of one of the following: a material that does not have energy elasticity but has rubber elasticity; a material that does not have rubber elasticity but has energy elasticity; or a material that has both rubber elasticity and energy elasticity. Similarly, the membrane portion 2 of this embodiment is also made of one of the following: a material that does not have energy elasticity but has rubber elasticity; a material that does not have rubber elasticity but has energy elasticity; or a material that has both rubber elasticity and energy elasticity.

[0041] Although not shown in the figures, in a modified version of the sound-insulating structure 1 of this embodiment, the weight portion 7 is a frustoconical shape that tapers away from the membrane portion 2. In this configuration, the release properties from the mold are good when the membrane portion 2 and the weight portion 7 are integrally molded. In this embodiment, the shape of the weight portion 7 can be determined arbitrarily and is not particularly limited.

[0042] In either of the first or second embodiment, the membrane portion 2 and the support wall portion 3 can be formed by integral molding or two-color molding using injection molding, compression molding, press molding, extrusion molding, transfer molding, casting, etc., of the aforementioned materials. Furthermore, the weight portions 4 and 7 can also be formed together with the membrane portion 2 and the support wall portion 3 by integral molding, two-color molding, insert molding, etc., of the aforementioned materials. However, the sound insulation structures 1 and 6 may also be assembled by forming the membrane portion 2, the support wall portion 3 and the weight portions 4 and 7 separately and then joining them together by adhesive or heat fusion.

[0043] In the configuration of the sound-insulating structures 1 and 6 described above, as shown in Figures 5(A) and 5(B), the support wall portion 3 includes a plurality of first wall portions 3a extending in a first direction D1 parallel to the membrane portion 2, and a plurality of second wall portions 3b extending in a second direction D2 perpendicular to the first direction D1, and the planar shape of each section 5 is square. In other words, the support wall portion 3 is a rectangular tube shape having a square cross-section that defines each section 5, and a large number of rectangular tube-shaped support wall portions 3 are arranged in a row, with the support wall portions 3 of adjacent sections 5 being integrated. However, the configuration is not limited to this. For example, although not shown, the planar shape of each section 5 may be triangular, and the support wall portion 3 may be a rectangular tube shape having a triangular cross-section that defines each section 5. Also, although not shown, the planar shape of each section 5 may be pentagonal, and the support wall portion 3 may be a rectangular tube shape having a pentagonal cross-section that defines each section 5. Although not shown, the planar shape of each section 5 may be hexagonal, and the support wall portion 3 may be a rectangular tube shape having a hexagonal cross-section defining each section 5, thus forming a so-called honeycomb structure. Furthermore, although not shown, the planar shape of each section 5 may be circular, and the support wall portion 3 may be a cylindrical shape having a circular cross-section defining each section 5. In the case where the planar shape of each section 5 is pentagonal or circular, gaps will occur between the sections 5, so it is preferable to determine the shape and dimensions of the support wall portion 3 so that the gaps are small, and it is preferable that the membrane portion 2 expands to close the gaps. In the case where the planar shape of each section 5 is triangular, quadrilateral, or hexagonal, no gaps will occur between the sections 5. Furthermore, each section 5 may be various shapes not shown, such as rectangles, parallelograms, trapezoids, polygons with heptagons or more, ellipses, oblongs, etc., and may also be irregular in shape. The support wall portion 3 is formed to match the planar shape of each section 5 in terms of shape and dimensions.

[0044] The sound-insulating structures 1 and 6 of the present invention are extremely thin and lightweight, and can be easily placed on curved or uneven surfaces, making them suitable for use on vehicle panels, particularly those of automobiles. Automobile panels are basically non-permeable plates, examples of which include metal plates (iron plates, steel plates, aluminum plates) and resin plates. When the panel on which the sound-insulating structure 1 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. When the sound-insulating 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-insulating structure 1 and 6, opposite to the side attached to the membrane portion 2, is placed on the panel. In this case, the support wall portion 3 and the panel may or may not be bonded, but it is preferable that the support wall portion 3 is not bonded to the panel and is placed on the panel for use.

[0045] Furthermore, the sound insulation structures 1 and 6 of the present invention may be used alone or 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 bonded together with the other members. When laminated or bonded together with other members, the sound insulation structures 1 and 6 may be placed in contact with the area on which they are mounted (for example, a car panel), or the other members may be placed in contact with that area. The other members used in combination with the sound insulation structures 1 and 6 may be made of various materials.

[0046] Parts in an automobile where the sound-insulating structures 1 and 6 of the present invention are installed include, in the engine compartment, the engine head cover, engine body cover, hood insulator, front dash insulator, airbox wall, air intake cleaner, dust side duct, under cover, etc.; in the cabin, the dash insulator, dash panel, floor carpet (floor silencer), spacer, door trim, interior of door trim, instrument panel, interior of instrument panel, instrument center box, instrument upper box, air conditioner housing, roof trim, interior of roof trim, sun visor, rear seat air conditioner duct, cooling duct for battery cooling system in battery-equipped vehicles, cooling fan, center console trim, interior of console, parcel trim, parcel panel, seat headrest, front seat back, rear seat back, rear floor, etc.; and in the trunk, the trunk side, trunk trim, interior of trunk trim, drafter cover, etc. Furthermore, the sound insulation structures 1 and 6 of the present invention can be installed within the frame of an automobile or between panels, and can also be installed on the underbody cover under the floor, fender protectors, fender liners that partially cover the tires, back doors, wheel covers, suspension aerodynamic covers, roof, and pillars that support the roof, which are located outside the vehicle. In particular, it is effective to place the sound insulation structure 1 or 6 of the present invention in at least one of the following locations: the dashboard panel and rear floor which have uneven or curved surfaces, the inside of the instrument panel which has fine uneven surfaces, the roof, pillars, door trims, fender liners which have curved surfaces, trunk sides, and trunk trims. In addition, in electric vehicles, although not shown, a heavy motor located in the floor portion of the passenger compartment may have the effect of suppressing vibrations in the floor portion, but it has little effect in suppressing noise from other parts of the vehicle. Therefore, suppressing the intrusion of noise from all directions into the passenger compartment of an automobile by the sound insulation structure 1 or 6 of the present invention is extremely effective in making the passenger compartment of an electric vehicle quieter.As mentioned above, the membrane portion 2 and the support wall portion 3 have a particularly flexible structure, making them easy to install on various curved surfaces and uneven surfaces of automobiles. The sound insulation structures 1 and 6 are held stably without the need for adhesive or other fixing, and by exhibiting good sound insulation in the low-frequency range, the quietness of the automobile's cabin can be improved.

[0047] Specific examples and comparative examples of the sound-insulating structure of the present invention are described below. [Example 1] The sound insulation structure 1 of Embodiment 1 of the present invention has a structure similar to a modified example of the first embodiment shown in Figure 3. The dimensions and shape of the sound insulation structure 1 of this embodiment will be described with reference to Figure 6. Both the membrane portion 2 and the support wall portion 3 of the sound insulation structure 1 of this embodiment are made of an elastic material having a dynamic storage modulus of 0.01 MPa to 100 MPa at 23°C and a frequency of 1 Hz to 1000 Hz, and a loss loss tangent of 0.01 to 0.50 at 23°C and a frequency of 1 Hz to 1000 Hz. More specifically, both the film portion 2 and the support wall portion 3 of this embodiment are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A13TPS") having a dynamic storage modulus (E') of 0.50 MPa and a loss tangent (tanδ) of 0.019 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.52 MPa and a loss tangent (tanδ) of 0.042 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 0.50 MPa and a loss tangent (tanδ) of 0.051 at 23°C and a frequency of 1000 Hz, a dynamic storage modulus (E') of 0.60 MPa and a loss tangent (tanδ) of 0.057 at 23°C and a frequency of 1000 Hz, and a durometer A hardness of 13 according to JIS K6253.

[0048] The membrane portion 2 in this embodiment is a flat sheet with a thickness of 1 mm. The support wall portion 3 in this embodiment has a height H1 of 10 mm in the direction perpendicular to the membrane portion 2, a thickness W1 of 1.6 mm at the position in contact with the membrane portion 2, and a tapered shape with a thickness W2 of 1.25 mm at the tip opposite the membrane portion 2. The angle (draft angle) θ that both surfaces of the support wall portion 3 make with respect to the direction perpendicular to the membrane portion 2 is 1 degree. However, only the outermost support wall portion 3 has thicknesses W1 and W2 that are halved to 0.8 mm and 0.625 mm, respectively. The distance (pitch) P between the centers of adjacent support wall portions 3 is 25 mm. Therefore, the section 5 defined by the multiple support wall sections 3 (first wall section 3a and second wall section 3b) is square in shape with a side length S of 23.4 mm on the surface of the membrane section 2. For example, if the membrane section 2 has a 200 mm x 200 mm square area, there are 49 sections 5 in that area. However, only a portion of this area is schematically shown in the drawing.

[0049] 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 of the weight portion 4, which is the part attached to the membrane portion 2, is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the membrane portion 2) of 3 mm. The mass portion 4b of the weight portion 4, which is the part opposite to the side attached to the membrane 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 having a dynamic storage modulus of 0.01 MPa to 100 MPa at 23°C and a frequency of 1 Hz to 1000 Hz, and a loss tangent of 0.01 to 0.50 at 23°C and a frequency of 1 Hz to 1000 Hz. More specifically, both the spring portion 4a and the mass portion 4b of the weight portion 4 in this embodiment are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A3TPS") with a dynamic storage modulus (E') of 0.21 MPa and a loss tangent (tanδ) of 0.038 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.23 MPa and a loss tangent (tanδ) of 0.031 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 0.29 MPa and a loss tangent (tanδ) of 0.051 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 0.25 MPa and a loss tangent (tanδ) of 0.166 at 23°C and a frequency of approximately 1000 Hz, with a durometer A hardness of 3 according to JIS K6253. The mass of the weight portion 4 is approximately 0.36 g. The surface density of this sound-insulating structure 1 is 2.45 kg / m². 2 The surface density is calculated from the dimensions of the membrane portion 2, support wall portion 3, and weight portion 4 in the unit structure section 5, and the density of the material in each part. The sound insulation performance of this sound insulation structure 1 was determined. Specifically, a model of the sound insulation structure 1 was created using COMSOL Multipyisics®, a general-purpose finite element method software, and the sound pressure levels on the reflective and transmitted sides were determined. From the transfer matrix obtained therefrom, the sound transmission loss at each frequency for perpendicularly incident sound waves was determined and is shown in Figures 7(A) and 7(B). The greater the sound transmission loss, the higher the sound insulation performance. In this embodiment, particularly high sound insulation performance is shown for sounds with a frequency of around 175 Hz.

[0050] [Example 2] The sound insulation structure 1 of Embodiment 2 of the present invention, shown in Figure 8, has a configuration that is generally the same as the sound insulation structure 1 of Embodiment 1, except that the membrane portion 2 is a flat sheet with a thickness of 1.3 mm. Since the configuration is the same as Embodiment 1 except for the thickness of the membrane portion 2, a detailed explanation is omitted. The surface density of this sound insulation structure 1 is 2.72 kg / m². 2 The sound insulation performance of this sound insulation structure 1 was determined and is shown in Figure 7(A). In this embodiment, it shows particularly high sound insulation performance against sounds with a frequency of approximately 225 Hz.

[0051] [Example 3] The sound insulation structure 1 of Embodiment 3 of the present invention shown in Figure 9 has a configuration that is generally the same as the sound insulation structure of Embodiment 1, but the hardness of the materials of the membrane portion 2 and the support wall portion 3 is different, as is the thickness of the spring portion 4a of the weight portion 4. In other words, both the membrane portion 2 and the support wall portion 3 of the sound insulation structure 1 in this embodiment are made of a styrene-based thermoplastic elastomer (hereinafter referred to as "A30TPS") with a dynamic storage modulus (E') of 0.82 MPa and a loss tangent (tanδ) of 0.044 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.88 MPa and a loss tangent (tanδ) of 0.041 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 1.08 MPa and a loss tangent (tanδ) of 0.096 at 23°C and a frequency of 1000 Hz, a dynamic storage modulus (E') of 1.19 MPa and a loss tangent (tanδ) of 0.144 at 23°C and a frequency of 1000 Hz, and a durometer A hardness of 30 according to JIS K6253. The dimensions and shape of the membrane portion 2 and the support wall portion 3 in this embodiment are the same as in Embodiment 1.

[0052] The weight portion 4 of this embodiment consists of a cylindrical spring portion 4a with an even smaller diameter than the spring portion 4a of the weight portion 4 of Embodiment 1, and a mass portion 4b similar to that of Embodiment 1. The spring portion 4a of this embodiment is cylindrical with a diameter of 3 mm and a height (dimension in the direction perpendicular to the membrane portion 2) of 3 mm. The mass portion 4b is cylindrical with a diameter of 9 mm and a height of 5 mm. Both the spring portion 4a and the mass portion 4b are made of A3TPS. The mass of the weight portion 4 is approximately 0.30 g. The surface density of this sound insulation structure 1 is 2.55 kg / m 2The other components are the same as in Example 1, so their explanation is omitted. The sound insulation performance of this sound insulation structure 1 was determined and is shown in Figure 7(A). In this example, it shows particularly high sound insulation performance against sounds with a frequency of approximately 175 Hz.

[0053] [Example 4] The sound insulation structure 1 of Embodiment 4 of the present invention, shown in Figure 10, has a configuration that is generally the same as the sound insulation structure 1 of Embodiment 3, except that the membrane portion 2 is a flat sheet with a thickness of 1.3 mm. Since the configuration is the same as Embodiment 3 except for the thickness of the membrane portion 2, a detailed explanation is omitted. The surface density of this sound insulation structure 1 is 2.84 kg / m². 2 The sound insulation performance of this sound insulation structure 1 was determined and is shown in Figure 7(A). In this embodiment, it shows particularly high sound insulation performance against sounds with a frequency of approximately 200 Hz.

[0054] [Example 5] The sound-insulating structure 6 of Embodiment 5 of the present invention shown in Figure 11 has a similar structure to that of the second embodiment shown in Figure 4. The membrane portion 2 and support wall portion 3 in this embodiment are the same as those in Embodiment 1. The weight portion 7 is made of A3TPS and is cylindrical with a diameter of 9 mm and a height (dimension in the direction perpendicular to the membrane portion 2) of 5 mm. The mass of the weight portion 7 is approximately 0.28 g, and the surface density of this sound-insulating structure 6 is 2.33 kg / m². 2 The rest of the configuration is the same as in Example 1, so we will omit the explanation. The sound insulation performance of this sound insulation structure 6 was determined and is shown in Figure 7(B). In this example, it shows particularly high sound insulation performance against sounds with a frequency of about 250 Hz.

[0055] [Comparative Example 1] As Comparative Example 1, the theoretical value of sound insulation performance calculated based on the mass law for a member with the same mass as the sound insulation structure 1 of Example 1 is shown in Figures 7(A) and 7(B), illustrating the relationship between frequency and sound transmission loss. The surface density of this configuration is 2.45 k / m². 2 In this comparative example, it exhibits particularly high sound insulation against sounds with frequencies of 1000 Hz or higher.

[0056] [Comparative Example 2] As Comparative Example 2, as shown in Figure 12, the sound insulation performance of a structure 8 that has only the same membrane portion 2 and support wall portion 3 as in Example 1, but without the weight portion 4, was measured and is shown in Figure 7(B). The surface density of this structure 8 is 2.14 kg / m³ 2 In this comparative example, it shows particularly high sound insulation against sounds with a frequency of around 950 Hz.

[0057] [Comparative Example 3] The structure of Comparative Example 3 has generally the same configuration as the sound-insulating structure 1 of Example 1, but the hardness of the materials of the membrane portion 2 and the support wall portion 3 is different. Specifically, both the membrane portion 2 and the support wall portion 3 of the structure in this comparative example are made of an olefin-based thermoplastic elastomer (hereinafter referred to as "A50TPO") with a dynamic storage modulus (E') of 8.14 MPa and a loss tangent (tanδ) of 0.104 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 9.42 MPa and a loss tangent (tanδ) of 0.095 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 10.42 MPa and a loss tangent (tanδ) of 0.889 at 23°C and a frequency of 1000 Hz, a dynamic storage modulus (E') of 11.84 MPa and a loss tangent (tanδ) of 0.106 at 23°C and a frequency of 1000 Hz, and a durometer A hardness of 50 according to JIS K6253. The dimensions and shape of the membrane portion 2 and the support wall portion 3 of this comparative example are the same as in Example 1. The weight portion 4 in this comparative example is the same as the weight portion 4 in Example 1. The surface density of this structure is 2.68 kg / m³. 2 The other components are the same as in Example 1, so their explanation is omitted. The sound insulation performance of this structure was determined and is shown in Figure 7(B). In this comparative example, particularly high sound insulation performance is observed for sounds with frequencies of approximately 650 to 675 Hz.

[0058] [result] The results of comparing Examples 1-5 of the present invention with Comparative Examples 1-3 described above will now be explained. Referring to Figure 7, it can be seen that the sound insulation effect is improved by the sound insulation structure 1 of the present invention. In particular, the sound insulation structure 1 of Examples 1-5 provides a greater sound insulation effect than the theoretical value based on the mass law (Comparative Example 1) and Comparative Example 2, which does not have weights 4 and 7, especially in the low frequency range (for example, the frequency range around 200 Hz), demonstrating the great effect of the present invention.

[0059] Referring to Figure 7, Examples 1 to 5 can be compared with Comparative Example 3, and it can be seen that the softness of the materials constituting the membrane portion 2 and the support wall portion 3 allows for a particularly high sound insulation effect in the low frequency range (for example, the frequency range around 200 Hz). In other words, the sound insulation structure 1 of the present invention is effective when sound insulation is required, especially in the low frequency range. Furthermore, as can be seen by comparing the sound insulation performance of Examples 1 and 2, and also by comparing the sound insulation performance of Examples 3 and 4, the frequency range at which sound insulation is particularly high can be adjusted by adjusting the thickness of the membrane portion 2.

[0060] The sound-insulating structure of the present invention enhances sound insulation, particularly in the low-frequency range, by constructing the membrane portion 2 and the support wall portion 3 from a soft material. However, in the case of a configuration in which the softness of the membrane portion 2 and the support wall portion 3 is reduced, as in Example 3, high sound insulation in the low-frequency range can be maintained by making the spring portion 4a of the weight portion 4 thinner. Therefore, even if there is a limit to how soft the membrane portion 2 can be made in order to support the weight portion 4, for example, the desired sound insulation in the low-frequency range can be achieved by making the spring portion 4a of the weight portion 4 thinner. Nevertheless, it is preferable that the membrane portion 2 and the support wall portion 3 have a durometer A hardness of 30 or less according to JIS K6253.

[0061] Furthermore, it can be seen that both the sound insulation structure 1 of the first embodiment of the present invention (Example 1) and the sound insulation structure 6 of the second embodiment (Example 5) can similarly achieve a good sound insulation effect. In the case where the weight portion 4 itself constitutes a spring-mass resonator, as in Example 1, particularly good sound insulation can be obtained near the frequency at which the vibration of the membrane portion 2 is reduced by the resonance of the spring-mass resonator. On the other hand, in the case where the weight portion 7 and the membrane portion 2 constitute a spring-mass resonator, as in Example 5, the frequency band in which sound insulation is particularly good can be adjusted by the weight of the weight portion 7. For example, by making the weight portion 7 heavier, the frequency band in which sound insulation is particularly good can be shifted to the lower frequency side.

[0062] [Soundproofing structure] Next, we will describe a soundproofing structure 11 that includes the soundproofing structures 1 and 6 of the present invention described above, and further enhances soundproofing performance while being easier to install. First, Figure 13 shows a side view of an automobile 100, which is an example of a vehicle equipped with this soundproofing structure 11. This automobile 100 may be an engine vehicle, an electric vehicle, a fuel cell vehicle, a hybrid vehicle, etc. The soundproofing structure 11 of the present invention is positioned so as to overlap a panel (dash panel) 14 provided at the boundary between the engine room 12 and the passenger compartment 13 of the automobile 100. A side view of this soundproofing structure 11 is shown in Figure 14, a perspective view of it from the front is shown in Figure 15, and a cross-sectional view of Figure 15 along line BB is shown in Figure 16. The soundproofing structure 11 shown in Figures 13 to 16 consists of a soundproofing plate-like part 10 and a soundproofing structure part 9 that are positioned side by side in plan. This soundproofing structure part 9 has the same configuration as either of the soundproofing structures 1 and 6 of the present invention described above. In other words, the sound insulation structure 9 consists of either the sound insulation structure 1 or 6 of the present invention described above. In this example, a large-area soundproof plate-like portion 10 and two sound insulation structure portions 9 (at least one of the membrane portion 2 and the support wall portion 3) are integrally formed or joined together to form a sound insulation structure 11 in which the soundproof plate-like portion 10 and the sound insulation structure portions 9 are positioned side by side in a planar manner and can be treated as a single component.

[0063] The soundproofing panel 10 may be made of materials similar to existing soundproofing materials, and may have a single-layer structure consisting of either a layer made of a sound-absorbing material such as felt, polyurethane foam, or glass wool, or a layer made of a sound-insulating material such as a resin film or rubber sheet, or a laminated structure thereof. These materials may also be made from biomass raw materials. The soundproofing panel 10 is a plate-shaped member that conforms to the shape of the panel 14, and its thickness may vary depending on the part. For example, the soundproofing panel 10 may have thin parts with a thickness of less than 5 mm and thick parts with a thickness of about 40 mm.

[0064] An example of the sound insulation structure 9 has the same configuration as the sound insulation structure 1 shown in Figures 1-2; that is, the sound insulation structure 9 consists of the sound insulation structure 1 of the present invention described above. This sound insulation structure 9 has an elastic sheet-like membrane portion 2, an elastic support wall portion 3 erected substantially vertically from the membrane portion 2, and an elastic weight portion 4 erected substantially vertically from the membrane portion 2. Each weight portion 4 located in each section 5 constitutes a spring-mass resonator having an elastic spring portion 4a and a mass portion (mass part) 4b with a mass greater than the spring portion 4a. The membrane portion 2 and the support wall portion 3 have a durometer A hardness of 30 or less according to JIS K6253. Since this sound insulation structure 9 has the same configuration as the sound insulation structure 1 shown in Figures 1-2, as described above, the vibration of the membrane portion 2 is controlled by the action of the spring-mass resonator formed by the spring portion 4a and mass portion 4b of the weight portion 4. In particular, in the low-frequency range (for example, frequencies below 500 Hz), membrane vibration is significantly reduced, resulting in high sound insulation.

[0065] In this soundproofing structure 11, the sound-insulating structure 9 with the aforementioned configuration is placed in areas of the vehicle where sound propagation is particularly high. In the example shown in Figure 13, the soundproofing structure 11 is placed so as to overlap with a panel 14 located at the boundary between the engine room 12 and the passenger compartment 13 of the automobile 100. The sound-insulating structure 9 is placed in two locations facing the front tires 15, which are areas where road noise and tire pattern noise propagation is particularly high. If the entire soundproofing structure 11, which is placed so as to overlap the panel 14, were composed of the sound-insulating structure 9 with the aforementioned configuration, the soundproofing effect would be high, but the weight of the soundproofing structure 11 would be large, which may adversely affect the performance of the vehicle. In contrast, in the soundproofing structure 11 of this embodiment, the sound-insulating structure 9 with a particularly high soundproofing effect is placed in areas where sound propagation is high (for example, the position facing the tires 15), and a simple soundproofing plate-like section 10 is placed in areas where sound propagation is not so high (positions other than the position facing the tires 15). This allows for efficient sound suppression while keeping the weight increase to a minimum. Furthermore, not only the soundproof plate-like section 10, which is formed to match the shape of the panel 14, but also the sound-insulating structure section 9 can be easily and stably installed on various shaped mounting surfaces without the need for adhesive or other fixing. Therefore, the soundproof structure 11 of this embodiment can be stacked on a panel 14 with a complex shape and held stably.

[0066] In this example, on one main surface of the soundproof structure 11 (the surface facing the passenger compartment 13, which faces to the right in Figures 13 and 14 and is the large surface mainly shown in Figure 15), the area occupied by the sound-insulating structure 9 is preferably 5% to 95% of the total area of ​​the soundproof structure 11, more preferably 10% to 40%, and even more preferably 20% to 30%. If the proportion of the area occupied by the sound-insulating structure 9 is too small, the sound insulation of the soundproof structure 11 equivalent to a dash silencer will be insufficient. Also, if the proportion of the area occupied by the sound-insulating structure 9 is too large, the noise transmitted to the passenger compartment through the soundproof structure 11 will be reflected by the instrument panel, and when it hits the surface of the soundproof structure 11 where sound-absorbing material is not laminated and is re-reflected, the sound pressure will increase, resulting in a muffled sound. In the example shown in Figures 13 to 16, the area occupied by the sound-insulating structure 9 is approximately 30% of the total area of ​​the soundproof structure 11.

[0067] In this example, the soundproofing panel 10 and the sound insulation structure 9 are integrated. Specifically, the layers of soundproofing material (felt, polyurethane foam, glass wool, etc.) or sound insulation material (resin film, rubber sheet, etc.) that constitute the soundproofing panel 10 and at least one of the membrane 2 and support wall 3 of the sound insulation structure 9 are integrally molded by insert molding or the like, or they are joined to each other by ultrasonic welding, hot melt adhesive bonding, clips, bolts, or rivets. As a result, the soundproofing structure 11 consisting of the soundproofing panel 10 and the sound insulation structure 9 can be easily handled.

[0068] The soundproofing structure 11 of the present invention is very thin and lightweight, not only in the soundproofing plate-like portion 10 but also in the sound-insulating structure portion 9 as described above. In particular, the membrane portion 2 and the support wall portion 3 are soft (durometer A hardness is 30 or less) and can be easily placed on curved or uneven surfaces, making it suitable for use on the panels of vehicles, especially automobiles 100 (for example, the panel 14 shown in Figure 13). Examples of panels on which the soundproofing structure 11 is placed may be the same as those on which the sound-insulating structures 1 and 6 described above are placed. The arrangement method, position, and usage form of the soundproofing structure 11 may be the same as those of the arrangement method, position, and usage form of the sound-insulating structures 1 and 6 described above.

[0069] The soundproofing structure 11 of the present invention has a sound-insulating structure 9 with the same configuration as the sound-insulating structures 1 and 6 exemplified in Examples 1 to 5 described above, and in addition, it is equipped with a sound-insulating plate-like portion 10. Therefore, it can be said that the difference in sound insulation performance of the sound-insulating structures 1 and 6 in Examples 1 to 5 represents the difference in sound insulation performance of each soundproofing structure 11. Furthermore, as mentioned above, the sound-insulating structures 1 and 6 in Examples 1 to 5 have greater sound insulation performance than the structures in Comparative Examples 1 to 3, especially in the low-frequency range, and it is considered that the soundproofing structure 11 of the present invention exhibits even better sound insulation performance because it is equipped with a sound-insulating plate-like portion 10.

[0070] In the automobile 100, the location where the soundproofing structure 11 of the present invention is installed is not limited to the dash panel 14 as described above, but can be installed in various locations, and it is preferable to install it in at least part of the member that partially separates the passenger compartment 13 of the automobile 100 from the outside of the vehicle. Figure 17 is a side view of the automobile 100 in which the soundproofing structure 11 is installed in various locations, Figure 18(A) is a perspective view from the front, and Figure 18(B) is a perspective view from the rear. In this example, the soundproofing structure 11 is installed in the roof portion 100a of the automobile 100, the pillar portions (supports) 100b and 100c that support the roof portion 100a, the door portion 100d, the fender portions 100e and 100f that partially cover the tires 15 and 16, respectively, and the trunk portion 100g. As shown in Figure 19, which is an enlargement of a part of Figure 17, the soundproofing structure 11 with the above configuration (see Figures 1 and 2) is installed inside the roof portion 100a of the automobile 100. This reduces the intrusion of noise into the passenger compartment 13 from above the vehicle. Furthermore, the pillar sections 100b and 100c are hollow cylindrical or rectangular tubes, with sound-insulating structures 11 embedded inside. This reduces the intrusion of noise into the passenger compartment 13 from around the windows of the vehicle 100. Figure 19 shows the rear pillar section 100c, but the front pillar section 100b also has a similar sound-insulating structure 11.

[0071] As an example, inside the door section 100d of the automobile 100, a soundproofing structure 11 with the aforementioned configuration (see Figures 1-2) is placed on a door trim (not shown). This soundproofing structure 11 suppresses the intrusion of noise from the door section 100d into the passenger compartment 13.

[0072] Furthermore, a soundproofing structure 11 with the aforementioned configuration (see Figures 1-2) is positioned on the vehicle compartment 13 side of the fender liner (not shown) on one fender portion 100e of the automobile 100. This soundproofing structure 11 suppresses the intrusion of noise from the tire 15 into the vehicle compartment 13. Similarly, on the other fender portion 100f, a soundproofing structure 11 of this embodiment is positioned on the vehicle compartment 13 side of the fender liner (not shown). These soundproofing structures 11 suppress the intrusion of noise (road noise and tire pattern noise) from the tires 15 and 16 in contact with the ground into the vehicle compartment 13.

[0073] The trunk trim (not shown) of the trunk section 100g of the automobile 100 has a structure in which a felt sheet material (not shown) and a thermoplastic resin plate member are laminated, and the soundproofing structure 11 with the above-described configuration (see Figures 1-2) is arranged thereon. Alternatively, the trunk trim may be constructed by laminating a soundproofing structure 11, in which a thermoplastic resin soundproofing plate-like part 10 and a sound insulation structure part 9 are integrated, onto a felt sheet material (not shown). Furthermore, the soundproofing structure 11 of this embodiment is arranged on both sides of the trunk section 100g, on the trunk sides (not shown). Therefore, the soundproofing structure 11 is arranged in at least three places inside the trunk section 100g, suppressing noise from the trunk section 100g and noise transmitted from the outside through the trunk section 100g from entering the passenger compartment 13.

[0074] As explained above, in the example shown in Figures 17-19, soundproofing structures 11 are placed on the roof 100a, pillars 100b, 100c, door 100d, fenders 100e, 100f, and trunk 100g of the automobile 100, suppressing the intrusion of noise into the passenger compartment 13 from all directions around the automobile 100. This makes it possible to keep the passenger compartment 13 quiet. However, not all of these soundproofing structures 11 are essential. If the soundproofing structures 11 of this embodiment are placed on at least some of the members that partially separate the passenger compartment 13 of the automobile 100 from the outside, a certain degree of effect can be obtained in keeping the passenger compartment 13 quiet. Furthermore, even if the soundproofing structure 11 is located in areas other than the roof portion 100a, pillar portions 100b, 100c, door portion 100d, fender portions 100e, 100f, and trunk portion 100g of the automobile 100, such as inside the instrument panel or on the rear floor, a certain degree of effectiveness can be obtained if the soundproofing structure 11 is located in at least a part of the members that partially separate the passenger compartment 13 from the outside of the vehicle. Members located outside the passenger compartment 13 of the automobile 100 generally interpose between the outside space and the passenger compartment 13, and therefore directly or indirectly separate the passenger compartment 13 from the outside space, and can be said to be members that partially separate the passenger compartment 13 of the automobile 100 from the outside of the vehicle. Note that the soundproofing structure 11 in each part may be exposed, but may also be covered by panels or sheets not shown.

[0075] The soundproofing structure 11 may be attached to existing components such as the panel (not shown) inside the roof section 100a, the interior of the pillar sections 100b and 100c, the door trim, fender liner, trunk trim, trunk side, interior of the instrument panel, and rear floor, or it may be provided as part of these existing components. In this embodiment, the lightweight and thin soundproofing structure 11 provides high sound insulation in a specific frequency range (for example, frequencies below 500 Hz, which are the main frequency ranges for road noise and tire pattern noise in the automobile 100), and also provides good installation without the need for adhesive. In particular, it can efficiently block noise from entering the passenger compartment 13 from all directions outside the automobile 100, resulting in a great soundproofing effect.

[0076] In the examples shown in Figures 17-19, the entire soundproof structure 11 may consist of a sound-insulating structure 9, or, as in the examples shown in Figures 13-16, the soundproof structure 11 may consist of a sound-insulating structure 9 and a soundproof plate-like section 10. In particular, when the soundproof structure 11 is provided as part of an existing component of the automobile 100, the soundproof structure 11 may consist of a sound-insulating structure 9 and a soundproof plate-like section 10. It is also possible to install the soundproof structure 11 independently without attaching it to a component such as a panel.

[0077] This invention includes the following configuration. [1] Having an elastic membrane portion and a weight portion erected on the membrane portion, Each of the aforementioned weight portions constitutes a spring-mass resonator having an elastic spring portion and a mass portion having a greater mass than the spring portion. A sound-insulating structure characterized in that the durometer A hardness of the membrane portion is 30 or less. [2] The sound-insulating structure according to [1], wherein the spring portion of the weight portion is located on the side of the weight portion that is attached to the membrane portion, and the mass portion is located on the side opposite to the side of the weight portion that is attached to the membrane portion. [3] The sound-insulating structure according to [1] or [2], wherein the mass portion of the weight portion has a larger volume than the spring portion. [4] The sound-insulating structure according to any one of [1] to [3], wherein the mass portion of the weight portion is made of a material with a higher density than the spring portion. [5] The membrane portion further has an elastic support wall portion erected thereon, The support wall surrounds the weight from the side without contacting it, and the end of the weight opposite to the side attached to the membrane is exposed and not covered by the support wall. The height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than the height of the weight portion extending in a direction perpendicular to the membrane portion. The sound-insulating structure according to any one of [1] to [4], wherein the durometer A hardness of the support wall portion is 30 or less. [6] The sound-insulating structure according to [5], wherein the membrane portion, the support wall portion, and the spring portion are all made of a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, and a material that has both rubber elasticity and energy elasticity. [7] The sound-insulating structure according to [5] or [6], wherein the membrane portion, the support wall portion, and the spring portion all have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at 23°C and frequencies from 1 Hz to 1000 Hz. [8] The sound insulation structure according to any one of [5] to [7], wherein the membrane portion, the support wall portion, and the spring portion all have a loss tangent of 0.01 or more and 0.50 or less at 23°C and frequencies from 1 Hz to 1000 Hz. [9] Having an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, The support wall surrounds the weight from the side without contact with the weight, and the end of the weight opposite to the side attached to the membrane is exposed and not covered by the support wall. The height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than the height of the weight portion extending in a direction perpendicular to the membrane portion. The aforementioned membrane portion constitutes a spring portion, and the aforementioned weight portion constitutes a mass portion, thus forming a spring-mass resonator. A sound-insulating structure characterized in that both the membrane portion and the support wall portion have a durometer A hardness of 30 or less.

[10] The sound-insulating structure according to [9], wherein both the membrane portion and the support wall portion are made of a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, and a material that has both rubber elasticity and energy elasticity.

[11] The sound-insulating structure according to [9] or

[10] , wherein both the membrane 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 frequencies from 1 Hz to 1000 Hz.

[12] The sound insulation structure according to any one of [9] to

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

[13] The sound-insulating structure according to any one of [5] to

[12] , wherein the membrane portion is divided into a plurality of sections by the support wall portion, and the weight portion is located inside all of the plurality of sections, or inside some of the plurality of sections, and in the sections in which the weight portion is located, one weight portion is arranged in one section.

[14] The sound-insulating structure according to

[13] , wherein the support wall portion is cylindrical with a circular, elliptical, or oblong cross-sectional shape defining each of the compartments, or rectangular tube with a polygonal cross-sectional shape defining each of the compartments.

[15] The area of ​​each of the above compartments is 100 mm² 2 Above 1000mm 2 The sound-insulating structures described in

[13] or

[14] below.

[16] Area of ​​the membrane portion 1000 cm² 2 A sound-insulating structure according to any one of

[13] to

[15] , wherein 10 to 1000 of the aforementioned compartments are provided per unit.

[17] Area of ​​the membrane portion: 1000 cm² 2 The sound insulation structure according to

[16] , wherein 50 to 500 of the aforementioned compartments are provided per unit.

[18] The sound-insulating structure according to any one of [5] to

[17] , wherein the membrane portion and the support wall portion are formed of the same material.

[19] The sound-insulating structure according to any one of [5] to

[18] , wherein the support wall portion includes a plurality of first wall portions extending in a direction perpendicular to the membrane portion and in a first direction parallel to the membrane portion, and a plurality of second wall portions extending in a direction perpendicular to the membrane portion and in a second direction perpendicular to the first direction.

[20] The sound insulation structure according to any one of [5] to

[19] , wherein the thickness of the support wall portion is 0.5 mm or more and 5.0 mm or less.

[21] The sound insulation structure according to

[20] , wherein the thickness of the support wall portion is 1.0 mm or more and 3.0 mm or less.

[22] The sound insulation structure according to any one of [5] to

[21] , wherein the height of the support wall portion extending in a direction perpendicular to the membrane portion is 5 mm or more and 20 mm or less.

[23] The sound insulation structure according to

[22] , wherein the height of the support wall portion extending in a direction perpendicular to the membrane portion is 10 mm or more and 20 mm or less.

[24] A sound insulation structure according to any one of [5] to

[23] , having a plurality of support wall portions, wherein some of the support wall portions have a greater height extending in a direction perpendicular to the membrane portion than the other support wall portions.

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

[24] , wherein the film thickness of the membrane portion is 0.1 mm or more and 3.0 mm or less.

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

[25] , wherein the height in the direction perpendicular to the membrane portion is 5 mm or more and 20 mm or less.

[27] The sound-insulating structure according to any one of [1] to

[26] , wherein the height of the weight portion extending in a direction perpendicular to the membrane portion is 1 mm or more.

[28] A soundproofing structure comprising a soundproofing plate-like part and a sound-insulating structure part, The aforementioned soundproofing plate-like portion is a plate-shaped member made of sound-absorbing material or sound-insulating material. The sound insulation structure consists of a sound insulation structure according to any one of [1] to

[27] , A soundproofing structure characterized in that at least one of the membrane portion and the support wall portion and the soundproofing plate-like portion are integrally formed or joined to each other, and the soundproofing plate-like portion and the sound insulation structure portion are positioned side by side in a planar manner.

[29] The soundproofing panel has a single-layer structure consisting of a layer made of felt, polyurethane foam, or glass wool and a layer made of a resin film or rubber sheet, or a multi-layer structure in which these are laminated, as described in

[28] .

[30] The soundproofing structure according to

[28] or

[29] , located in at least one of the following locations of an automobile: the dashboard, the interior of the instrument panel, the roof, the pillars supporting the roof, the door trim, the fender liners partially covering the tires, the trunk sides, the trunk trim, and the rear floor.

[31] A soundproofing structure according to any of

[28] to

[30] , which is located inside an electric vehicle. A soundproofing structure comprising the sound insulation structure described in any of

[32] [1] to

[27] , and positioned in at least one of the following locations: the dashboard panel of an automobile, the interior of the instrument panel, the roof, the pillars supporting the roof, the door trim, the fender liner partially covering the tires, the trunk side, the trunk trim, and the rear floor. A soundproofing structure comprising any of the sound-insulating structures described in

[33] [1] to

[27] , and positioned inside an electric vehicle. [Explanation of symbols]

[0078] 1.6 Sound insulation structure 2 Membrane part 3 Support wall section 3a 1st wall 3b 2nd wall part 4,7 Weight 4a Spring part 4b Mass part 5 plots 8 Structure 9. Sound insulation structure 10 Soundproof panel-like section 11 Soundproofing Structures 12 Engine Room 13 Cabin 14 Panels (Dash Panel) 15, 16 tires 100 automobiles 100a Roof section 100b, 100c Pillar section (support column section) 100d Door section 100e, 100f fender section 100g Trunk section

Claims

1. It has an elastic membrane portion and a weight portion erected on the membrane portion, Each of the aforementioned weight portions constitutes a spring-mass resonator having an elastic spring portion and a mass portion having a greater mass than the spring portion. A sound-insulating structure characterized in that the durometer A hardness of the membrane portion is 30 or less.

2. The aforementioned membrane portion further comprises an elastic support wall portion erected on the membrane portion, The support wall surrounds the weight from the side without contacting it, and the end of the weight opposite to the side attached to the membrane is exposed and not covered by the support wall. The height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than the height of the weight portion extending in a direction perpendicular to the membrane portion. The sound insulation structure according to claim 1, wherein the durometer A hardness of the support wall portion is 30 or less.

3. The sound-insulating structure according to claim 2, wherein the membrane portion, the support wall portion, and the spring portion are all made of a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, and a material that has both rubber elasticity and energy elasticity.

4. The sound insulation structure according to claim 2 or 3, wherein the membrane portion, the support wall portion, and the spring portion all 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.

5. The sound insulation structure according to claim 4, wherein the membrane portion, the support wall portion, and the spring portion all have a loss tangent of 0.01 or more and 0.50 or less at 23°C and frequencies from 1 Hz to 1000 Hz.

6. The sound-insulating structure according to claim 1 or 2, wherein the spring portion of the weight portion is located on the side of the weight portion that is attached to the membrane portion, and the mass portion is located on the side of the weight portion that is attached to the membrane portion.

7. It has an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, The support wall surrounds the weight from the side without contact with the weight, and the end of the weight opposite to the side attached to the membrane is exposed and not covered by the support wall. The height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than the height of the weight portion extending in a direction perpendicular to the membrane portion. The aforementioned membrane portion constitutes a spring portion, and the aforementioned weight portion constitutes a mass portion, thus forming a spring-mass resonator. A sound-insulating structure characterized in that both the membrane portion and the support wall portion have a durometer A hardness of 30 or less.

8. The sound insulation structure according to claim 7, wherein both the membrane portion and the support wall portion are made of a material that does not have energy elasticity but has rubber elasticity, a material that does not have rubber elasticity but has energy elasticity, or a material that has both rubber elasticity and energy elasticity.

9. The sound-insulating structure according to claim 7 or 8, wherein both the membrane 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.

10. The sound insulation structure according to claim 9, wherein both the membrane portion and the support wall portion have a loss tangent of 0.01 or more and 0.50 or less at 23°C and frequencies from 1 Hz to 1000 Hz.

11. The sound insulation structure according to claim 2 or 7, wherein the membrane portion is divided into a plurality of sections by the support wall portion, and the weight portion is located inside all of the plurality of sections, or inside some of the plurality of sections, and in the sections in which the weight portion is located, one weight portion is arranged in one section.

12. The sound-insulating structure according to claim 2 or 7, wherein the membrane portion and the support wall portion are formed from the same material.

13. A soundproofing structure consisting of a soundproofing plate-like part and a sound-insulating structure part, The aforementioned soundproofing plate-like portion is a plate-shaped member made of sound-absorbing material or sound-insulating material. The sound insulation structure consists of the sound insulation structure described in claim 2 or 7. A soundproofing structure characterized in that at least one of the membrane portion and the support wall portion and the soundproofing plate-like portion are integrally formed or joined to each other, and the soundproofing plate-like portion and the sound insulation structure portion are positioned side by side in a planar manner.

14. The soundproofing structure according to claim 13, wherein the soundproofing panel-like portion has a single-layer structure consisting of a layer made of felt, polyurethane foam, or glass wool, and a layer made of a resin film or rubber sheet, or a multi-layer structure in which these are laminated.

15. A soundproofing structure according to claim 13, which is placed inside an electric vehicle.

16. A soundproofing structure comprising the sound insulation structure described in claim 1 or 7, and disposed inside an electric vehicle.

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