Soundproofing structures and sound insulation structures

Abstract

The present invention provides a thin and lightweight sound-insulating structure that offers sufficient sound insulation, can be stably mounted, and has good sound insulation over a wide frequency range. [Solution] The soundproofing structure 11 comprises a sound-insulating structure 1 and a plate-shaped member 8 on which the sound-insulating structure 1 is placed. The sound-insulating structure 1 comprises 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 greater mass than the spring portion 4a. The plate-shaped member 8 is made of aluminum, an aluminum alloy, or resin.

Description

[Technical Field]

[0001] This invention relates to soundproofing structures and sound insulation 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 road noise, tire pattern noise, wind noise, engine noise, etc., in order 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, sound-insulating structures. In recent years, lightweight sound-insulating structures have been required for buildings due to the increasing height of buildings, and lightweight sound-insulating structures are also required for vehicles to improve energy efficiency. Examples of soundproofing structures installed in automobiles and other vehicles are disclosed in Patent Documents 1 to 4.

[0003] The sound-absorbing material (dash silencer) disclosed in Patent Document 1 is made of foam material and has an interference portion and a gap-filling structure portion so that no gap is created between the sound-absorbing material and the dash panel to which it is attached.

[0004] In the automobile body structure disclosed in Patent Document 2, a sheet-like soundproofing material made of asphalt-based vibration damping material is attached to the rear wheel house lining.

[0005] In the vehicle disclosed in Patent Document 3, a fender protector is attached inside the wheelhouse. It has ribs erected on the surface (back surface) of the fender protector on the wheelhouse side, and a sound-absorbing material that covers the ribs and is attached in close contact at least at the peripheral part to the back surface of the fender protector or the back surface of the ribs, and the part in contact with the ribs is lifted from the back surface of the fender protector. The space surrounded by the back surface of the fender protector, the side surface of the ribs, and the sound-absorbing material is configured as a closed sound-absorbing air chamber. The sound-absorbing material is heat-welded to the fender protector, the outer surface of the sound-absorbing material is brought into contact with the vehicle body panel constituting the wheelhouse of the vehicle, and a closed second sound-absorbing air chamber is formed between the recessed part, which is the heat-welded part of the sound-absorbing material heat-welded to the back surface of the fender protector or the back surface of the ribs, and the vehicle body panel.

[0006] In the panel structure of an automobile disclosed in Patent Document 4, it is a double-wall panel in which a sealed intermediate layer is formed between opposing inner and outer walls, and at least one of the front and rear, left and right, and upper and lower wall parts of the passenger space is constituted. The double-wall panel is composed of a fixed part attached to the vehicle body and a non-fixed part, and the weight of the vehicle parts attached to the non-fixed part is included, and the weight of the non-fixed part of the inner wall and the vehicle parts attached to the non-fixed part of the inner wall and the non-fixed part of the outer wall and the vehicle parts attached to the non-fixed part of the outer wall is set to be substantially the same.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] The dash silencer described in Patent Document 1 does not have a special sound insulation structure and cannot sufficiently reduce the noise entering the vehicle interior. In particular, road noise and tire pattern noise transmitted from the tires contacting the ground into the vehicle interior are large, and there is a possibility that a quiet and comfortable space cannot be provided for the passengers.

[0009] The vehicle body structure of the automobile described in Patent Document 2 also does not have a special sound insulation structure and cannot sufficiently reduce the noise entering the vehicle interior. Just a sheet-shaped sound insulation material made of an asphalt-based vibration damping material cannot sufficiently suppress the road noise and tire pattern noise transmitted from the rear-wheel tires into the vehicle interior, and it is difficult to realize a quiet vehicle interior.

[0010] In the invention described in Patent Document 3, it is intended to reduce the intrusion of noise from the fender, but it does not have a special sound insulation structure and cannot sufficiently reduce the noise entering the vehicle interior.

[0011] In the invention described in Patent Document 4, a double-wall panel with good weight balance is provided, but a special sound insulation structure is not formed, and the noise entering the vehicle interior cannot be completely suppressed.

[0012] The structures described in Patent Documents 1 to 4 aim to make the vehicle interior of an automobile quiet, but no special sound insulation structure for suppressing the intrusion of noise into the vehicle interior has been proposed. And none of the configurations described in Patent Documents 1 to 4 has sufficient sound insulation performance against the noise entering the vehicle interior, and a sound insulation structure with higher sound insulation performance is desired.

[0013] Therefore, an object of the present invention is to provide a sound insulation structure that can obtain sufficient sound insulation performance, is thin and lightweight, and has good sound insulation performance against noise in a wide frequency range.

Means for Solving the Problems

[0014] The first soundproofing structure of the present invention comprises a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, wherein the sound-insulating structure comprises an elastic membrane portion and a weight portion erected on the membrane portion, and 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 plate-shaped member is made of aluminum, an aluminum alloy, or a resin. The membrane portion further comprises an elastic support wall portion erected thereon, the support wall portion surrounding the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion being exposed and not covered by the support wall portion, and the height of the support wall portion extending in a direction perpendicular to the membrane portion may be greater than the height of the weight portion extending in a direction perpendicular to the membrane portion. 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). The membrane portion, the support wall portion, and the spring portion may all be made of one of the following materials: 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. The membrane portion, the support wall portion, and the spring portion may all have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at 23°C and frequencies from 1 Hz to 1000 Hz. Furthermore, the membrane portion, the support wall portion, and the spring portion may all be made of an elastic material with a loss tangent of 0.01 or more and 0.50 or less at 23°C and frequencies from 1 Hz to 1000 Hz. Specifically, the elasticity of the membrane, support wall, and spring 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 determining a master curve based on 23°C, wherein the dynamic storage modulus (E') at 23°C and frequencies from 1 Hz to 1000 Hz is 0.01 MPa or more and 100 MPa or less. Furthermore, more preferably, both the membrane and the support wall may be made of an elastic material having a dynamic storage modulus (E') at 23°C and frequencies from 1 Hz to 1000 Hz of 0.05 MPa or more and 50 MPa or less, and a loss tangent at 23°C and frequencies from 1 Hz to 1000 Hz of 0.01 or more and 0.45 or less. The spring portion of the weight may be located on the side of the weight that is attached to the membrane portion, and the mass portion may be located on the side of the weight that is attached to the membrane portion. The mass portion of the weight may have a larger volume than the spring portion. The mass portion of the weight may be made of a material with a higher density than the spring portion.

[0015] The second soundproofing structure of the present invention comprises a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, wherein the sound-insulating structure comprises an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, wherein the support wall portion surrounds the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion, 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 membrane portion constitutes a spring-mass resonator as a spring portion and the weight portion as a mass portion, and the plate-shaped member is made of aluminum, an aluminum alloy, or a resin. Both the membrane portion and the support wall portion may be made of 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. Both the membrane portion and the support wall portion may 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. Furthermore, both the membrane portion and the support wall portion may be made of an elastic material having a loss tangent of 0.01 or more and 0.50 or less at 23°C and frequencies from 1 Hz to 1000 Hz. More preferably, both the membrane portion and the support wall portion may be made of an elastic material having a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less at 23°C and frequencies from 1 Hz to 1000 Hz, and a loss tangent of 0.01 or more and 0.45 or less at 23°C and frequencies from 1 Hz to 1000 Hz.

[0016] The first soundproofing structure and the second soundproofing 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.

[0017] The soundproofing structure of the present invention comprises a sound-insulating structure portion made of the sound-insulating structure and a plate-shaped soundproofing plate portion made of a sound-absorbing material or a sound-insulating material, wherein at least one of the membrane portion and the support wall portion of the sound-insulating structure portion and the soundproofing plate portion are integrally formed or joined to each other, and the soundproofing plate portion and the sound-insulating structure portion may be 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.

[0018] The sound-insulating structure of the present invention comprises an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, wherein the support wall portion surrounds the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion, 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, and 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 is characterized in that it is mounted on a plate-shaped member made of aluminum, an aluminum alloy, or a resin. Furthermore, another sound insulation structure of the present invention comprises a sound insulation structure and a plate-shaped member on which the sound insulation structure is placed, wherein the sound insulation structure comprises an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, wherein the support wall portion surrounds the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion, 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 membrane portion constitutes a spring-mass resonator as a spring portion and the weight portion as a mass portion, and is characterized in that it is placed on a plate-shaped member made of aluminum, an aluminum alloy, or a resin. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a thin and lightweight soundproofing structure that can be easily mounted on curved or uneven surfaces such as panels of buildings, machinery, or vehicles (e.g., automobiles), while also providing good soundproofing performance over a wide frequency range. [Brief explanation of the drawing]

[0020] [Figure 1] (A) is a cross-sectional view of a soundproofing structure according to the first embodiment of the present invention, and (B) is a perspective view of the sound-insulating structure of the soundproofing structure. [Figure 2] (A) is an exploded perspective view of one section of the sound insulation structure shown in Figure 1(B), and (B) is an exploded front view thereof. [Figure 3] (A) is a cross-sectional view of a modified soundproofing structure according to the first embodiment of the present invention, and (B) is a perspective view of the sound-insulating structure of the soundproofing structure. [Figure 4] (A) is a cross-sectional view of a soundproofing structure according to a second embodiment of the present invention, and (B) is a perspective view of the sound-insulating structure of the soundproofing structure. [Figure 5] (A) is a schematic plan view showing one section of the sound insulation structure of the soundproofing structure of the present invention, and (B) is a schematic plan view showing multiple sections thereof. [Figure 6] (A) and (B) are graphs showing the sound insulation performance of Examples 1 and 2 and Comparative Examples 3 and 6 of the present invention. [Figure 7] This graph shows the sound insulation performance of Examples 1-2 and Comparative Examples 1-2, 4-5 of the present invention. [Figure 8] This is a cross-sectional view showing a soundproofing structure according to Embodiment 2 of the present invention. [Figure 9] This is a cross-sectional view showing the structure of Comparative Example 4. [Figure 10] This is a cross-sectional view showing the structure of Comparative Example 5. [Figure 11] This is a side view of an automobile equipped with the soundproofing structure of the present invention. [Figure 12] Figure 11 is a side view of the soundproofing structure. [Figure 13] Figure 12 is a perspective view of the soundproofing structure as seen from the front. [Figure 14] Figure 13 is a cross-sectional view along line BB. [Figure 15] This is a side view of another automobile equipped with the soundproofing structure of the present invention. [Figure 16] (A) is a perspective view of the automobile shown in Figure 15, seen from the front, and (B) is a perspective view seen from the rear. [Figure 17] Figure 15 is a side view showing a magnified portion of the automobile. [Figure 18] Figure 15 is a perspective view of the door section of an automobile. [Figure 19]Figure 15 is a side view of the fender section of an automobile. [Figure 20] Figure 19 is a perspective view of the fender liner of the fender section shown. [Figure 21] Figure 15 is a perspective view of the trunk area of ​​the automobile. [Figure 22] Figure 21 is a plan view of the trunk trim of the trunk section. [Figure 23] Figure 21 is a side view of the trunk side of the trunk section. [Figure 24] (A) is a perspective view showing the area including the instrument panel of the automobile, and (B) is a perspective view showing the instrument panel in the open position. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] Figure 1(A) is a cross-sectional view of the soundproofing structure 11 of the first embodiment of the present invention, cut at the position of line AA in Figure 2, which will be described later. This soundproofing structure 11 is a structure in which a sound insulation structure 1 is attached to a plate-shaped member 8. The plate-shaped member 8 is made of a lightweight material such as aluminum or an aluminum alloy, or a resin such as carbon fiber reinforced plastic (CFRP). The density of the plate-shaped member 8 is 1.0 g / cm³. 3 ~3.0g / cm 3It is a plate-like material with a thickness of approximately 0.5 mm to 5 mm, and is, for example, part of an automobile body panel. Figure 1(B) is a perspective view of the sound insulation structure 1 of the soundproofing structure 11 shown in Figure 1(A). 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, that is, 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).

[0022] The support wall portion 3 of this embodiment has a constant thickness (plate thickness) from the position in contact with the membrane portion 2 to the opposite end, and extends linearly perpendicular to the membrane portion 2. This 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. 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 of the plurality of square sections 5 partitioned by the first wall portions 3a and the second wall portions 3b are 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. Here, "flexible material" 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 (plate-shaped members 8) 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.

[0023] 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.

[0024] 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.

[0025] 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, thereby increasing the sound insulation performance of the entire sound insulation structure 1. Also, since the number of compartments 5 is 1000 or less per area of the film portion 2, an increase in the weight of the entire sound insulation structure 1 can be suppressed. The area of the planar shape of each 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 portion 4 inside, and particularly a large sound insulation property can be obtained in a 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 portion 4 on the film portion 2 is large, and a high sound insulation property can be obtained. The height of the entire sound insulation structure 1 in the direction orthogonal to the film portion 2 is preferably 5 mm or more and 20 mm or less. Since the height of the entire sound insulation structure 1 is 5 mm or more, the weight portion 4 can have a sufficient height as a spring mass resonator, and since the height is 20 mm or less, an increase in the weight of the entire sound insulation structure 1 can be suppressed. Each drawing schematically shows each compartment 5, the support wall portion 3, etc. Although the number and area of the compartments 5 and the height of the support wall portion 3 may not be shown exactly accurately or may not be unified in each drawing, it is preferable that the number and area of the compartments 5 and the height of the support wall portion 3 are appropriately designed so as to fall within the numerical ranges described above respectively.

[0026] ​​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.

[0027] The membrane portion 2 is preferably a relatively rigid elastic membrane because the weight portion 4 is attached to it. The dynamic storage modulus (E') of the membrane portion 2 is preferably 15 MPa or higher, and the thickness (film thickness) is preferably 0.1 mm to 3.0 mm, and more preferably about 0.5 mm. If the thickness of the membrane portion 2 is 0.1 mm or higher, sufficient thickness can be ensured, making it easy to handle. If the thickness of the membrane portion 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 portion 2 is preferably a durometer A hardness of 50 or higher according to JIS K6253, and more preferably 70 or higher. If the durometer A hardness of the membrane portion 2 is 50 or higher, the vibration of the membrane portion 2 is good, and the sound insulation performance in the frequency band to be sound-insulated is good. The stiffness (axial stiffness) k of membrane 2 is expressed as k = E' × A / L, where E' is the dynamic storage modulus, A is the cross-sectional area of ​​membrane 2, and L is the thickness of membrane 2. The area of ​​membrane 2 to be evaluated for stiffness is 1000 cm². 2 When the stiffness k is 10 6 N / mm or more 10 9 Preferably N / mm or less, 3 × 10 6 N / mm or more 10 8 It is more preferable that the density is N / mm or less. The area of ​​membrane portion 2 is 1000 cm². 2 The stiffness when it is 10 6 By having a density of N / mm or higher, the deterioration of vibration of membrane 2 can be suppressed, resulting in good sound insulation in the frequency band targeted for sound insulation. The area of ​​membrane 2 is 1000 cm². 2 The stiffness when it is 10 9 By having a density of N / mm or less, the sound-insulating structure 1 becomes flexible, resulting in good installation flexibility. Furthermore, the bending stiffness K of the membrane 2 is expressed as K = E' × I, based on the dynamic storage modulus E' and the second moment of area I. The second moment of area I is calculated as I = b × h, based on the thickness h and width b of the membrane 2. 3 The calculation is / 12. The area of ​​membrane 2 to be evaluated is 1000 cm². 2 When the bending stiffness K is 30 N / mm 2 The above 10 5 N / mm 2 The following is preferable: 50 N / mm2 The above 5 x 10 4 N / mm 2 The following is more preferable: The area of ​​membrane portion 2 is 1000 cm². 2 The bending stiffness K is 30 N / mm². 2 As a result of the above, the vibration of the membrane 2 is improved, and the deterioration of sound insulation performance in the frequency band to be sound-insulated can be suppressed. The area of ​​the membrane 2 is 1000 cm². 2 The bending stiffness K is 10 5 N / mm 2 The following conditions make the sound-insulating structure 1 flexible and improve installation ease. The cross-sectional shape of the membrane portion 2 is not particularly limited and may be flat or uneven.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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. Although not shown in the figures, the support wall portion 3 may have partially different heights. If the height of the support wall portion 3 is partially different, the higher 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 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 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 such that its durometer A hardness according to JIS K6253 is between 1 and 90, and more preferably between 10 and 70. If the durometer A hardness of the support wall 3 is 1 or higher, the good shape retention of the sound insulation structure 1 is maintained, and if it is 90 or lower, the transmission of vibrations from the support wall 3 to the membrane 2 and deterioration of sound insulation performance are suppressed, and the sound insulation structure 1 is flexible and easy to install. The stiffness k of the support wall 3 is expressed as k = E' × A / L, where E' is the dynamic storage modulus, A is the cross-sectional area of ​​the support wall 3, and L is the height of the support wall 3, and the area of ​​the support wall 3 to be evaluated for stiffness is 1000 cm². 2 When the stiffness k is 10 N / mm or more, 6 Preferably N / mm or less, 10 2 N / mm or more 10 5 It is more preferable that the density is N / mm or less. The area of ​​the support wall 3 is 1000 cm². 2 The rigidity k at this time is 10 N / mm or more, which allows the shape retention of the sound insulation structure 1 to be maintained. The area of ​​the support wall 3 is 1000 cm².2 The stiffness k at this time is 10 6 By having a value of N / mm or less, vibrations from the support wall 3 are prevented from being transmitted to the membrane 2, thus preventing deterioration of sound insulation performance, and the sound insulation structure 1 is not rigid, resulting in good installation flexibility.

[0032] 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.

[0033] Although not shown in the figures, the support wall portion 3 in this embodiment may have 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. This support wall portion 3 may have a tapered shape with both surfaces inclined, or one surface may be inclined and the other surface may extend 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.

[0034] 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.

[0035] The material of the mass portion 4b is not particularly limited, but it is made of resin or metal, and the mass portion 4b has a greater mass than the spring portion 4a, for example, a mass of 0.1 g or more and 2.0 g or less. Preferably, the mass portion 4b has a mass of twice or more the mass of the spring portion 4a. When 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 the sound insulation performance does not deteriorate. If the material of the mass portion 4b is resin, the resin may be made from biomass raw materials.

[0036] 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.

[0037] 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 can be 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.

[0038] The sound insulation structure 1, as described above, is placed on a plate-shaped member 8 to form the soundproofing structure 11 of this embodiment. In this embodiment, the plate-shaped member 8 on which the sound insulation structure 1 is placed is a part of an automobile body panel made of aluminum, an aluminum alloy, or a resin such as CFRP. By placing the flexible sound insulation structure 1 on any part of a lightweight material such as aluminum, an aluminum alloy, or CFRP, or a structure containing them (for example, a part of an automobile body panel), high sound insulation in the low-frequency range due to the effect of the sound insulation structure 1 and high sound insulation in the high-frequency range due to the hollow double-wall effect can be obtained. In recent years, automobile body panels with complex shapes are sometimes formed using lightweight materials such as aluminum, an aluminum alloy, or CFRP, but because of the complex shape, it can be difficult to stably place conventional sound insulation structures on them. However, as described above, the sound insulation structure 1 of this embodiment has a flexible membrane portion 2 and a support wall portion 3, so it can be stably placed on a plate-shaped member such as a body panel 8 with a complex shape. As a result, it can exhibit high sound insulation performance in both low-frequency and high-frequency ranges, and a soundproof structure 11 with a stable structure is realized.

[0039] The specific structure of the sound-insulating structure 1 of the soundproofing structure 11 of this embodiment is not limited to the configuration shown in Figures 1 and 2. Modified examples of the sound-insulating structure 1 of this embodiment are described below. In the modified examples described below, the spring portion 4a and the mass portion 4b of the weight portion 4 of the sound-insulating structure 1 have different shapes and dimensions. Figure 3(A) is a cross-sectional view of the modified soundproofing structure 11 of the first embodiment of the present invention, cut at the position of line AA in Figure 3(B), which will be described later. Figure 3(B) is a perspective view of the sound-insulating structure 1 of the soundproofing structure 11 shown in Figure 3(A). In the modified example 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 examples, 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.

[0040] 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.

[0041] [Second Embodiment] Figure 4(A) is a cross-sectional view of a modified soundproofing structure 11 of the first embodiment of the present invention, cut at the position of line AA in Figure 4(B), which will be described later. Figure 4(B) is a perspective view of the sound insulation structure 6 of the soundproofing structure 11 shown in Figure 4(A). This sound insulation structure 6 has a single 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 the 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.

[0042] 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.

[0043] 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.

[0044] Although not shown in the figures, in a modified version of the sound-insulating structure 6 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.

[0045] 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.

[0046] 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.

[0047] The sound-insulating structures 1 and 6 of the present invention are very thin and lightweight, and can be easily placed on curved or uneven surfaces, making them suitable for use on the panels of vehicles, particularly automobiles. Automobile panels are basically non-permeable plates, and in this invention, the sound-insulating structures 1 and 6 are placed on a plate-shaped member 8 made of a lightweight material such as aluminum, an aluminum alloy, or CFRP to form a sound-insulating structure 11. When the plate-shaped member 8 is made of aluminum or an aluminum alloy, its thickness is preferably in the range of 0.5 mm to 2.0 mm. When the plate-shaped member 8 is made of a resin plate such as CFRP, its thickness is preferably in the range of 0.5 mm to 20 mm. 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 plate-shaped member 8. In this case, the support wall portion 3 and the plate-shaped member 8 may or may not be bonded, but it is preferable that the support wall portion 3 is not bonded to the plate-shaped member 8 and is placed on the plate-shaped member 8 for use.

[0048] In automobiles, the parts that constitute the soundproofing structure 11 of the present invention, i.e., the plate-shaped members 8 on which the sound insulation structures 1 and 6 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 of 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 soundproofing structure 11 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-insulating structures 1,6 of the soundproofing structure 11 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 using the soundproofing structure 11 of the present invention is extremely effective in making the passenger compartment of an electric vehicle quiet.As mentioned above, the membrane portion 2 and support wall portion 3 of the sound insulation structure 1 are particularly flexible, allowing for good installation on plate-shaped members 8 of various parts of an automobile that have curved surfaces and irregularities. The sound insulation structures 1 and 6 are held stably without the need for adhesive or other fixing, resulting in a good soundproof structure 11 that exhibits good sound insulation in both low and high frequency bands, thereby enhancing the quietness of the automobile's cabin.

[0049] Specific examples and comparative examples of the soundproofing structure 11 of the present invention are described below. [Example 1] The soundproofing structure 11 of Embodiment 1 of the present invention comprises a sound-insulating structure 1 having a structure similar to that of a modified example of the first embodiment shown in Figures 1-2, and a plate-shaped member 8 made of an aluminum plate with a thickness of 2 mm. The membrane portion 2 of the sound-insulating structure 1 of this embodiment is 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, the film portion 2 of this embodiment is made of EPDM (ethylene-propylene-diene rubber) with a dynamic storage modulus (E') of 20.4 MPa and loss tangent (tanδ) of 0.12 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 23.0 MPa and loss tangent (tanδ) of 0.13 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 25.4 MPa and loss tangent (tanδ) of 0.16 at 23°C and a frequency of 100 Hz, a dynamic storage modulus (E') of 28.8 MPa and loss tangent (tanδ) of 0.14 at 23°C and a frequency of 1000 Hz, a durometer A hardness of 70 according to JIS K6253, and a film thickness of 0.5 mm.

[0050] The support wall portion 3 of this embodiment is made of an elastic body having a dynamic storage modulus of 0.01 MPa to 100 MPa at 23°C and frequencies from 1 Hz to 1000 Hz, and a loss loss tangent of 0.01 to 0.50 at 23°C and frequencies from 1 Hz to 1000 Hz. More specifically, the support wall 3 of this embodiment is made of EPDM with a dynamic storage modulus (E') of 13.2 MPa and a loss tangent (tanδ) of 0.12 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 15.0 MPa and a loss tangent (tanδ) of 0.14 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 17.4 MPa and a loss tangent (tanδ) of 0.17 at 23°C and a frequency of 100 Hz, a dynamic storage modulus (E') of 20.2 MPa and a loss tangent (tanδ) of 0.16 at 23°C and a frequency of 1000 Hz, a durometer A hardness of 65 according to JIS K6253, a plate thickness of 1.6 mm, and a height of 10 mm in the direction perpendicular to the film 2. However, only the outermost support wall 3 has half the plate thickness, 0.8 mm. The compartments 5 defined by multiple support walls 3 (first wall 3a and second wall 3b) are square in shape, measuring 25 mm x 25 mm, and there are approximately 100 compartments 5 within the 260 mm x 260 mm square area (evaluation surface) of the membrane 2. However, only a portion of this area is schematically shown in the drawing. The weight 4 is cylindrical with a diameter of 6 mm and a height (dimension perpendicular to the membrane 2) of 6 mm.

[0051] The spring portion 4a of the weight portion 4, which is the part attached to the membrane portion 2, has a height of 3 mm and is made of an elastic material whose dynamic storage modulus at 23°C and frequencies from 1 Hz to 1000 Hz is between 0.01 MPa and 100 MPa, and whose loss tangent at 23°C and frequencies from 1 Hz to 1000 Hz is in the range of 0.01 to 0.50. More specifically, the spring portion 4a of this embodiment is made of silicone rubber with a durometer A hardness of 10 according to JIS K6253, with a dynamic storage modulus (E') of 0.60 MPa and a loss tangent (tanδ) of 0.17 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.74 MPa and a loss tangent (tanδ) of 0.24 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 0.97 MPa and a loss tangent (tanδ) of 0.17 at 23°C and a frequency of 1000 Hz, and a dynamic storage modulus (E') of 1.31 MPa and a loss tangent (tanδ) of 0.16 at 23°C and a frequency of 1000 Hz. The mass portion 4b of the weight portion 4, which is the part opposite to the side attached to the membrane portion 2, also has a height of 3 mm and is made of rigid stainless steel (SUS304). The mass of the weight portion 4 is approximately 0.8 g, and it exhibits a resonance peak at a frequency of 600 Hz to 650 Hz in the direction perpendicular to the mounting surface of the weight portion 4.

[0052] The end face of the support wall portion 3 of this sound insulation structure 1, opposite to the side attached to the membrane portion 2, is placed on a 2.0 mm thick aluminum plate (plate-shaped member) 8 to form the soundproof structure 11 shown in Figure 1. The overall height of the soundproof structure 11 is 12.5 mm, its weight is 530.9 g, and its surface density is 7.9 kg / m². 2The surface density is calculated from the dimensions of the membrane section 2, support wall section 3, weight section 4, and plate-like member 8 in the unit structure section 5, and the density of the material in each part. The sound insulation performance was measured with the side opposite to the side on which the sound insulation structure 1 of the aluminum plate 8 was placed as the incident sound side. Specifically, following the intensity method shown in JIS A1441-1, a test facility room in which the sound source room was a reverberation chamber and the receiving room was a semi-anechoic chamber was used, and the sound transmission loss (transmission loss) [dB] for the 1 / 3 octave band center frequency [Hz] was determined by 1 / 3 octave band analysis. The relationship between the 1 / 3 octave band center frequency and sound transmission loss is shown in Table 1 and Figure 6(A). The greater the sound transmission loss, the higher the sound insulation performance. In the 1 / 3 octave band center frequency [Hz] shown in Figures 6(A) to 6(B), 1 kHz is 1000 Hz, and the prefix "k" means 1000. The average transmission loss in the frequency range of 500Hz to 8kHz is 48.3dB, as shown in Table 1 and Figure 7.

[0053] [Table 1]

[0054] [Example 2] The soundproofing structure 11 of Example 2 shown in Figure 8 has the same structure as Example 1, but has a thinner aluminum plate 8 with a thickness of 0.8 mm compared to the plate-shaped member 8 of Example 1. The sound insulation structure 1 of this example is the same as the sound insulation structure 1 of Example 1. The overall height of this soundproofing structure 11 is 11.3 mm, its weight is 314.8 g, and its surface density is 4.7 kg / m². 2 The relationship between the 1 / 3 octave band center frequency and sound transmission loss of this soundproofing structure 11 is shown in Table 1 and Figure 6(B). The average transmission loss in the frequency band from 500 Hz to 8 kHz is 42.7 dB, as shown in Table 1 and Figure 7.

[0055] [Comparative Example 1] As Comparative Example 1, the theoretical value of sound insulation calculated based on the mass law for the same mass (530.9g) as the soundproofing structure 11 of Example 1 is shown in Table 1. The average transmission loss in the frequency range of 500Hz to 8kHz is 41.6dB, as shown in Table 1 and Figure 7.

[0056] [Comparative Example 2] As Comparative Example 2, the theoretical value of sound insulation calculated based on the mass law for the same mass (314.8g) as the soundproofing structure 11 of Example 2 is shown in Table 1. The average transmission loss in the frequency range of 500Hz to 8kHz is 37.1dB, as shown in Table 1 and Figure 7.

[0057] [Comparative Example 3] Although not shown in the figures, the structure of Comparative Example 3 is similar to the soundproofing structure 11 of Example 1, but instead of the aluminum plate (plate-like member) 8 of Example 1, it has a hard stainless steel plate with a thickness of 0.8 mm. The sound insulation structure 1 of this Comparative Example is the same as the sound insulation structure 1 of Example 1. This sound insulation structure 1 is placed on the stainless steel plate, the overall height of the structure is 11.3 mm, the weight is 582.2 g, and the surface density is 8.6 kg / m 2 The relationship between the 1 / 3 octave band center frequency and the acoustic transmission loss of this structure is shown in Table 1 and Figures 6(A) and 6(B). The average transmission loss in the frequency band from 500 Hz to 8 kHz is 49.3 dB, as shown in Table 1.

[0058] [Comparative Example 4] In Comparative Example 4 shown in Figure 9, only a 2mm thick aluminum plate 8 is present, and sound insulation structures 1 and 6 are not provided. The weight of this aluminum plate 8 is 355.9g, and the surface density is 5.3kg / m². 2 The relationship between the 1 / 3 octave band center frequency and the sound transmission loss of this aluminum plate 8 is shown in Table 1 and Figure 6(A). The average transmission loss in the frequency band from 500 Hz to 8 kHz is 34.0 dB, as shown in Table 1 and Figure 7.

[0059] [Comparative Example 5] In Comparative Example 5 shown in Figure 10, only an aluminum plate 8 with a thickness of 0.8 mm is present, and sound insulation structures 1 and 6 are not provided. The weight of this aluminum plate 8 is 139.8 g, and the surface density is 2.1 kg / m². 2 The relationship between the 1 / 3 octave band center frequency and the sound transmission loss of this aluminum plate 8 is shown in Table 1 and Figure 6(B). The average transmission loss in the frequency band from 500 Hz to 8 kHz is 28.6 dB, as shown in Table 1 and Figure 7.

[0060] [Comparative Example 6] Although not shown in the diagram, in Comparative Example 6, only a 0.8 mm thick stainless steel plate exists, and sound insulation structures 1 and 6 are not provided. The weight of this stainless steel plate is 407.2 g, and the surface density is 6.0 kg / m². 2 The relationship between the 1 / 3 octave band center frequency and the sound transmission loss of this stainless steel plate was determined and is shown in Table 1 and Figures 6(A) and 6(B). The average transmission loss in the frequency band from 500 Hz to 8 kHz is 37.7 dB, as shown in Table 1.

[0061] [result] The results of comparing Examples 1-2 and Comparative Examples 1-6 of the present invention, as described above, are explained below. Referring to Figures 6(A), 6(B), and 7, it can be seen that the sound insulation effect is improved by the soundproofing structure 11 of the present invention. With the soundproofing structure 11 of Example 1, it can be seen that a significantly greater sound insulation effect is obtained over a wide frequency range than the theoretical value based on the mass law (Comparative Example 1) or when the sound insulation structure 1 is not present (Comparative Example 4). Similarly, with the soundproofing structure 11 of Example 2, a significantly greater sound insulation effect is obtained over a wide frequency range than the theoretical value based on the mass law (Comparative Example 2) or when the sound insulation structure 1 is not present (Comparative Example 5), demonstrating the great effectiveness of the present invention.

[0062] Furthermore, referring to Figures 6(A) and 6(B), it can be seen that Examples 1 and 2 can achieve a sound insulation effect comparable to that of Comparative Example 3. In Comparative Example 3, where the sound insulation structure 1 is placed on a stainless steel plate, extremely good sound insulation is obtained compared to Comparative Example 6 and others, where the sound insulation structure 1 is not provided. However, for the sake of weight reduction and ease of forming complex shapes, aluminum and aluminum alloys or resins (CFRP, etc.), which are softer than stainless steel, are sometimes used for things like automobile body panels. Even in such cases, the soundproofing structure 11 of Examples 1 and 2 of the present invention can achieve sound insulation close to that of the structure in which the sound insulation structures 1 and 6 are placed on a stainless steel plate (Comparative Example 3). In other words, the soundproofing structure 11 of the present invention can achieve a high level of balance between high sound insulation over a wide frequency range and weight reduction and ease of forming complex shapes.

[0063] Although specific examples are not shown, both the modified soundproofing structure 11 of the first embodiment of the present invention shown in Figure 3 and the soundproofing structure 11 of the second embodiment shown in Figure 4 can achieve a good sound insulation effect similar to that of the soundproofing structures 11 of Examples 1 and 2. When the weight portion 4 itself constitutes a spring-mass resonator, as in the soundproofing structures 11 of Examples 1 and 2, 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, when the spring-mass resonator is composed of the weight portion 7 and the membrane portion 2, as in the soundproofing structure 11 of the second embodiment, 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.

[0064] [Examples of soundproofing installations] An example of the installation of a soundproof structure 11, which has the sound insulation structures 1 and 6 with the configuration described above and offers high sound insulation and is easy to install, will be described. A side view of an automobile 100, which is an example of a vehicle equipped with this soundproof structure 11, is shown in Figure 11. This automobile 100 may be an engine vehicle, an electric vehicle, a fuel cell vehicle, a hybrid vehicle, etc. The soundproof structure 11 of the present invention is installed on 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 soundproof structure 11 is shown in Figure 12, a perspective view of it from the front is shown in Figure 13, and a cross-sectional view of Figure 13 along line BB is shown in Figure 14. The soundproof structure 11 shown in Figures 11 to 14 includes a soundproof plate-like part 10 and a sound insulation structure part 9 that are positioned side by side in plan. At least a part of the panel 14 on which these soundproof plate-like parts 10 and sound insulation structure part 9 are placed is the plate-like member 8 described above. Therefore, in the drawing, the reference numeral 8 for the plate-shaped member is shown in parentheses next to panel 14. The sound insulation structure 9 has the same configuration as either of the sound insulation structures 1 or 6 of the present invention described above. That is, the sound insulation structure 9 consists of either of the sound insulation structures 1 or 6 of the present invention described above. In this example, the large-area soundproof plate-shaped part 10 and two sound insulation structure parts 9 (at least one of the membrane part 2 and the support wall part 3) are formed integrally or joined together so that the soundproof plate-shaped part 10 and the sound insulation structure parts 9 are positioned side by side in a planar manner and can be treated as a single component.

[0065] 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.

[0066] 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 larger mass than the spring portion 4a. 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 the 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, and high sound insulation performance is achieved. Then, the end of this sound-insulating structure 9 opposite to the side in contact with the membrane 2 of the support wall 3 is placed on a lightweight plate-shaped member 8 made of aluminum or an aluminum alloy or resin such as CFRP, thereby forming the soundproof structure 11.

[0067] In this example, the sound-insulating structure 9, as described above, is placed in parts of the vehicle where sound propagation is particularly high. In the example shown in Figure 11, the soundproofing structure 11 is installed on a panel 14 located at the boundary between the engine compartment 12 and the passenger compartment 13 of the automobile 100. At least a portion of this panel 14 (at least the portion on which the sound-insulating structure 9 is placed) is made of a lightweight plate-like member 8 such as aluminum or an aluminum alloy or CFRP, as described above, and constitutes the soundproofing structure 11 of the present invention. The sound-insulating structure 9 is placed at two locations facing the front tires 15, which are areas where road noise and tire pattern noise propagation is particularly high. If the sound-insulating structure 9, as described above, were provided throughout the entire soundproofing structure 11, 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, a 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 tire 15), and a soundproofing plate-like section 10 with a simple structure is placed in areas where sound propagation is not so high (positions other than the position facing the tire 15). This makes it possible to efficiently suppress the intrusion of sound while keeping the increase in weight to a minimum. Furthermore, not only the soundproofing plate-like section 10 formed to match the shape of the panel 14, but also the sound-insulating structure 9 can be easily and stably installed on mounting surfaces (plate-like members 8) of various shapes without having to fix them by adhesive or the like. Therefore, the soundproofing structure 11 of this embodiment can be made into a stable structure that includes a panel 14 with a complex shape.

[0068] In this example, on one main surface of the soundproofing structure 11 (the surface facing the passenger compartment 13, which faces to the right in Figures 11 and 12 and is the large surface mainly shown in Figure 13), the area occupied by the sound insulation structure 9 is preferably 5% to 95% of the total area of ​​the soundproofing structure 11, more preferably 10% to 40%, and even more preferably 20% to 30%. If the proportion of the area occupied by the sound insulation structure 9 is too small, the sound insulation performance of the soundproofing structure 11 equivalent to a dash silencer will be insufficient. Also, if the proportion of the area occupied by the sound insulation structure 9 is too large, noise transmitted to the passenger compartment through the soundproofing structure 11 will be reflected by the instrument panel, and when it hits the surface of the soundproofing 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 11 to 14, the area occupied by the sound insulation structure 9 is approximately 30% of the total area of ​​the soundproofing structure 11.

[0069] In this example, the soundproof panel-like section 10 and the sound-insulating structure section 9 are integrated. Specifically, the layers of soundproofing material (felt, polyurethane foam, glass wool, etc.) or sound-insulating material (resin film, rubber sheet, etc.) constituting the soundproof panel-like section 10 and at least one of the membrane section 2 and support wall section 3 of the sound-insulating structure section 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 soundproof panel-like section 10 and the sound-insulating structure section 9 can be integrated and easily handled.

[0070] In this invention, not only the soundproofing plate-like portion 10, but also the sound-insulating structure portion 9, as described above, is very thin and lightweight, and can be easily placed on curved or uneven surfaces. Therefore, the soundproofing structure 11 can be easily constructed by placing it on a panel of a vehicle, especially an automobile 100 (for example, panel 14 shown in Figure 11). An example of the plate-like member 8 that constitutes part of the soundproofing structure 11 may be the same as the panel on which the sound-insulating structures 1 and 6 described above are placed. The installation method, location, and usage form of the soundproofing structure 11 may be the same as the arrangement method, location, and usage form of the soundproofing structure 11 described above.

[0071] The soundproofing structure 11 of the present invention has a sound insulation structure 9 with the same configuration as the sound insulation structures 1 and 6 exemplified in Examples 1 and 2 described above, and in addition, it is equipped with a sound insulation plate-like section 10 and a plate-like member 8. Therefore, it can be said that the difference in sound insulation performance of the sound insulation structures 1 and 6 of Examples 1 and 2 represents the difference in sound insulation performance of each soundproofing structure 11. Furthermore, as mentioned above, the sound insulation structures 1 and 6 of Examples 1 and 2 have greater sound insulation performance over a wider frequency band than the structures of Comparative Examples 1 to 2 and 4 to 6, 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 insulation plate-like section 10.

[0072] In the automobile 100, the location where the soundproofing structure 11 of the present invention is provided is not limited to the dash panel 14 as described above, but can be provided in various locations, and it is preferable to provide it in at least a part of the part that partially separates the passenger compartment 13 of the automobile 100 from the outside of the vehicle. Figure 15 is a side view of the automobile 100 in which the soundproofing structure 11 is provided in various locations, Figure 16(A) is a perspective view from the front, and Figure 16(B) is a perspective view from the rear. In this example, the roof portion 100a of the automobile 100, the pillar portions (support portions) 100b, 100c that support the roof portion 100a, the door portion 100d, the fender portions 100e, 100f that partially cover the tires 15, 16 respectively, and the trunk portion 100g each contain the plate-shaped member 8 described above, and the sound insulation structure portion 9 (a structure similar to the sound insulation structures 1, 6 described above) is placed on the plate-shaped member 8 to constitute the soundproofing structure 11. As shown in Figure 17, which is an enlargement of a portion of Figure 15, the soundproofing structure 11 described above (see Figures 1-2) is installed inside the roof portion 100a of the automobile 100. This suppresses the intrusion of noise from above the automobile into the passenger compartment 13. In addition, the pillar portions 100b and 100c are hollow cylindrical or rectangular tubes, and the soundproofing structure 11 is installed inside them. This suppresses the intrusion of noise from around the windows of the automobile 100 into the passenger compartment 13. Figure 17 shows the rear pillar portion 100c, but the front pillar portion 100b is also similarly provided with the soundproofing structure 11.

[0073] Figure 18 is a perspective view showing the interior of the door section 100d of the automobile 100. Inside the door section 100d, at least a portion of the door trim 17 is the aforementioned plate-shaped member 8, and a sound insulation structure 9 (with a structure similar to the aforementioned sound insulation structures 1 and 6) is placed thereon to form a soundproof structure 11. This soundproof structure 11 suppresses the intrusion of noise from the door section 100d into the passenger compartment 13.

[0074] Figure 19 is a side view showing the main part of one fender section 100e of the automobile 100, and Figure 20 is a perspective view showing the fender liner 18. At least a portion of the fender liner 18 on the passenger compartment 13 side is the aforementioned plate-shaped member 8, and a sound insulation structure 9 (with a structure similar to the aforementioned sound insulation structures 1 and 6) is placed thereon to constitute a soundproof structure 11. This soundproof structure 11 suppresses the intrusion of noise from the tire 15 into the passenger compartment 13. Although not shown in Figures 19 and 20, the other fender section 100f also has the same soundproof structure 11 configured on the passenger compartment 13 side of the fender liner 18. These soundproof 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 passenger compartment 13.

[0075] Figure 21 is a perspective view showing the interior of the trunk section 100g of the automobile 100. Figure 22 is a plan view of the trunk trim 19 of the trunk section 100g. This trunk trim 19 is constructed by laminating a felt sheet material (not shown) and a thermoplastic resin plate member, at least a part of which is the aforementioned plate member 8, and a sound insulation structure 9 (similar in structure to the aforementioned sound insulation structures 1 and 6) is placed on it to constitute the soundproofing structure 11. Alternatively, the trunk trim 19 may be constructed by laminating a soundproofing structure 11, in which a thermoplastic resin soundproofing plate-like part 10, a sound insulation structure 9, and a plate member 8 are integrated, onto a felt sheet material (not shown). Also, although not shown in Figure 22, trunk sides 20 are arranged on both sides of the interior of the trunk section 100g. These trunk sides 20 are shown in Figure 23. At least a portion of the trunk side 20 is the aforementioned plate-shaped member 8, and a sound-insulating structure 9 (with a structure similar to the aforementioned sound-insulating structures 1 and 6) is placed thereon to constitute the soundproof structure 11. Therefore, soundproof structures 11 are provided in at least three locations 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.

[0076] As explained above, in the example shown in Figures 15-23, soundproofing structures 11 are provided in the roof section 100a, pillar sections 100b, 100c, door section 100d, fender sections 100e, 100f, and trunk section 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 configured in 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 provided 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, for example, inside the instrument panel or rear floor, a certain degree of effect can be obtained if the soundproofing structure 11 is provided 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 space outside the vehicle and the passenger compartment 13, and therefore directly or indirectly separate the passenger compartment 13 from the space outside the vehicle, and can be said to be members that partially separate the passenger compartment 13 of the automobile 100 from the outside of the vehicle. Figure 24(A) shows the area including the instrument panel 21 of the automobile, in which the soundproofing structure 11 is configured. Figure 24(B) shows the instrument panel 21 in the open position. Although the soundproofing structure 11 is not shown in Figure 24(B), even if the instrument panel 21 has many fine irregularities inside, the sound insulation structures 1 and 6 of the present invention are easy to install because the membrane portion 2 and the support wall portion 3 are soft, and the soundproofing structure 11 can be easily constructed to exhibit a soundproofing effect. The soundproofing structure 11 of each part may be exposed, but may also be covered by a panel or sheet not shown.

[0077] 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 17, the fender liner 18, the trunk trim 19, the trunk side 20, the interior of the instrument panel 21, and the rear floor, or some of these existing components may be formed as plate-shaped members 8. In this embodiment, the lightweight and thin soundproofing structure 11 provides high sound insulation over a wide frequency range, and good installation is possible 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.

[0078] In the examples shown in Figures 15 to 24, the sound-insulating structure 9 may be provided throughout the entire soundproof structure 11, and the soundproof structure 11 may have both a sound-insulating structure 9 and a sound-insulating plate-like section 10, similar to the examples shown in Figures 11 to 14. In particular, when the soundproof structure 11 is constructed using some of the existing components of the automobile 100, the soundproof structure 11 may have both a sound-insulating structure 9 and a sound-insulating plate-like section 10.

[0079] This invention includes the following configuration. [1] comprising a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, The sound-insulating structure comprises an elastic membrane portion and a weight portion erected on the membrane portion, and 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. The soundproofing structure is characterized in that the plate-shaped member is made of aluminum, an aluminum alloy, or a resin. [2] The soundproofing 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 soundproofing structure according to [1] or [2], wherein the mass portion of the weight portion has a larger volume than the spring portion. [4] The soundproofing 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 comprises an elastic support wall portion erected on the membrane portion, The support wall surrounds the weight from the side without contacting it. The end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion. The soundproofing structure according to any one of [1] to [4], wherein 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. [6] The soundproofing 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 soundproofing 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 soundproofing 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] comprising a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, The sound-insulating structure comprises an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, wherein the support wall portion surrounds the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion, 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, and the membrane portion constitutes a spring-mass resonator with the weight portion acting as a spring and the weight portion as a mass portion. The soundproofing structure is characterized in that the plate-shaped member is made of aluminum, an aluminum alloy, or a resin.

[10] The soundproofing 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 soundproofing 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 soundproofing 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 soundproofing 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 area of ​​each of the above compartments is 100 mm² 2 Above 1000mm 2 The soundproofing structure described in

[13] is as follows:

[15] Area of ​​the membrane portion: 1000 cm² 2 The soundproofing structure according to

[13] or

[14] , wherein 10 to 1000 of the above compartments are provided per unit.

[16] Area of ​​the membrane portion 1000 cm² 2 The soundproofing structure according to

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

[17] The soundproofing structure according to any one of

[13] to

[16] , 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.

[18] The soundproofing structure according to any one of [5] to

[16] , 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.

[19] The soundproofing structure according to any one of [5] to

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

[20] The soundproofing 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 soundproofing 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 soundproofing 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 soundproofing 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] The soundproofing 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 insulation structure comprises a sound insulation structure and a plate-shaped soundproof plate made of a sound-absorbing material or a sound-insulating material, The soundproofing structure according to any one of [5] to

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

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

[25] .

[27] The soundproofing structure according to any one of [1] to

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

[28] The soundproofing structure according to any one of [1] to

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

[29] The soundproofing structure according to any one of [1] to

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

[30] A soundproofing structure according to any one of [1] to

[29] provided 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 liner partially covering the tires, the trunk side, the trunk trim, and the rear floor.

[31] A soundproofing structure described in any of [1] to

[30] , which is installed inside an electric vehicle.

[32] 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. 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 by being placed on a plate-shaped member made of aluminum, an aluminum alloy, or a resin.

[33] 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 by being placed on a plate-shaped member made of aluminum, an aluminum alloy, or a resin. [Explanation of Symbols]

[0080] 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 Plate-shaped member 9. Sound insulation structure 10 Soundproof panel-like section 11 Soundproofing structure 12 Engine Room 13 Cabin 14 Panels (Dash Panel) 15, 16 tires 17 Door trim 18 Fender Liner 19 Trunk trim 20 Trunk side 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 comprises a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, The sound-insulating structure comprises an elastic membrane portion and a weight portion erected on the membrane portion, and 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. The soundproofing structure is characterized in that the plate-shaped member is made of aluminum, an aluminum alloy, or a resin.

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. The end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion. The soundproofing structure according to claim 1, wherein 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.

3. The soundproofing 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 soundproofing 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 soundproofing 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 soundproofing structure according to any one of claims 1 to 3, 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 comprises a sound-insulating structure and a plate-shaped member on which the sound-insulating structure is placed, The sound-insulating structure comprises an elastic membrane portion, an elastic support wall portion erected on the membrane portion, and a weight portion erected on the membrane portion, wherein the support wall portion surrounds the weight portion from the side without contact with the weight portion, the end of the weight portion opposite to the side attached to the membrane portion is exposed and not covered by the support wall portion, 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, and the membrane portion constitutes a spring-mass resonator with the weight portion acting as a spring and the weight portion as a mass portion. The soundproofing structure is characterized in that the plate-shaped member is made of aluminum, an aluminum alloy, or a resin.

8. The soundproofing 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, and a material that has both rubber elasticity and energy elasticity.

9. The soundproofing 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 soundproofing 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 soundproofing structure according to any one of claims 2, 3, 7, or 8, 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 soundproofing structure according to any one of claims 2, 3, 7, or 8, wherein the membrane portion and the support wall portion are formed of the same material.

13. It comprises a sound-insulating structure made of the aforementioned sound-insulating structure, and a plate-shaped sound-insulating plate made of sound-absorbing material or sound-insulating material, The soundproofing structure according to any one of claims 2, 3, 7, or 8, wherein at least one of the membrane portion and the support wall portion of the soundproofing structure and the soundproofing plate-like portion are integrally formed or joined to each other, and the soundproofing plate-like portion and the soundproofing structure 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 any one of claims 1, 2, 3, 7, or 8, provided 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.

16. A soundproofing structure according to any one of claims 1, 2, 3, 7, or 8, installed inside an electric vehicle.

17. 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. 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 by being placed on a plate-shaped member made of aluminum, an aluminum alloy, or a resin.

18. 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 by being placed on a plate-shaped member made of aluminum, an aluminum alloy, or a resin.

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