Soundproof structure and soundproof structure of automobile

Abstract

To provide a thin and light-weight soundproof structure that can provide sufficient sound insulating properties, and can be easily and stably mounted on a panel of an automobile having a curved surface or irregularities.SOLUTION: A soundproof structure 8 is arranged in one or both of at least part of a position at which a space in which a rear wheel tire is accommodated and a cabin are partitioned from each other and at least part of a position at which a space in which a front wheel tire is accommodated and the cabin are partitioned from each other, in an automobile, and includes a soundproof structure part 8a. The soundproof structure part 8a has a film part 2 having elasticity, support wall parts 3 erected on the film part 2 and having elasticity, and weight parts 4 erected on the film part 2. The film part 2 is divided into a plurality of sections by the support wall parts 3, and one weight part 4 is arranged in one section. The height of the support wall part 3 is larger than the height of the weight part 4. Each of the weight parts 4 forms a spring-mass resonator having a spring part 4a having elasticity and a mass part 4b having a larger mass than the spring part 4a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a soundproof structure and a soundproof structure for an automobile. [Background technology]

[0002] In recent years, there has been a demand for reducing noise in the interior of an automobile to provide a quiet and comfortable space for occupants by blocking out noises such as road noise, tire pattern noise, wind noise, and engine noise. Therefore, there is a demand for means for suppressing the propagation of noise and vibration from the outside of the automobile to the inside, and also for the propagation of noise and vibration from the outside of the passenger compartment to the passenger compartment within the automobile, i.e., for members with high soundproofing properties. In recent years, there has been a demand for lightweight soundproofing members to improve the energy efficiency of automobiles. Examples of soundproofing structures installed in automobiles and the like are disclosed in Patent Documents 1 to 9.

[0003] Patent Documents 1 and 2 disclose automotive dash silencers (also called dash insulators). These dash silencers are laminated to a dash panel (dashboard) located at the boundary between the space housing the front tires and the passenger compartment, and suppress noise from entering the passenger compartment from the space housing the front tires. Dash silencers have a single-layer or multi-layer structure that includes felt or urethane foam as sound-absorbing materials.

[0004] The sound-absorbing material (dash silencer) disclosed in Patent Document 3 is made of foam material and has an interference section and a gap-filling structure section, so that no gaps occur between the sound-absorbing material and the dash panel to which it is attached.

[0005] The vehicle dash silencer disclosed in Patent Document 4 has a large-area main dash silencer portion, a small-area auxiliary dash silencer portion, and a locking means for maintaining the stacked state of both portions, and the auxiliary dash silencer portion is stacked in a position of the main dash silencer portion where sound insulation is required. Both the main dash silencer and the auxiliary dash silencer portion are made of a fiber laminate or the like.

[0006] In the automobile body structure disclosed in Patent Document 5, a sheet-like soundproofing material made of asphalt-based vibration-damping material is attached to the rear wheel well inner panel.

[0007] The invention described in Patent Document 6 is an acoustic damping panel comprising a rigid frame divided into a plurality of individual cells, a sheet of flexible material, and a plurality of weights, each weight being fixed to the sheet of flexible material so that each cell is provided with a weight, and the attenuated sound is controlled by appropriate selection of the mass of the weights.

[0008] In the invention described in Patent Document 7, in a soundproofing material comprising an elastic sheet and a support portion that holds the sheet and divides the sheet into partitions, the relationship between the rigidity of the sheet in the partitions and the surface density of the sheet is specified.

[0009] The sound-proofing material of the invention described in Patent Document 8 is a structure comprising a flat substrate portion and a plurality of resonating portions connected to the substrate portion and having a predetermined resonant frequency, each of the plurality of resonating portions having a weight portion and a connecting portion that connects the weight portion to the substrate portion, and is configured so that, in a projection view seen from a direction perpendicular to the substrate portion, the center of gravity of the resonating portion is located outside the joint area between the substrate portion and the connecting portion.

[0010] The vibration reduction device of the invention described in Patent Document 9 has an acoustic meta-structure that is attached to the vehicle body and blocks vibrations transmitted through the vehicle body, and includes a cross-shaped frame that is attached to the vehicle body and divides a certain space into certain areas, and vibrators that are configured at the corners of each area divided by the frame and have their respective natural frequencies, blocking vibrations transmitted from the vehicle body through the frame. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-210381 [Patent Document 2] Japanese Patent Application Publication No. 2018-012353 [Patent Document 3] Patent No. 6616970 [Patent Document 4] Patent No. 5512197 [Patent Document 5] Patent No. 2996035 [Patent Document 6] Japanese Patent Application Laid-Open No. 2005-250474 [Patent Document 7] Patent No. 6879369 [Patent Document 8] Patent Publication No. 2021-152584 [Patent Document 9] Japanese Patent Publication No. 2020-91481 Summary of the Invention [Problem to be solved by the invention]

[0012] The dash silencers and the like described in Patent Documents 1 to 4 do not have a special soundproofing structure and are unable to sufficiently reduce noise entering the vehicle cabin. In particular, road noise and tire pattern noise transmitted from the tires in contact with the ground into the vehicle cabin are large, which may prevent the provision of a quiet and comfortable space for the occupants.

[0013] The body structure of the automobile described in Patent Document 5 does not have a special soundproofing structure, and is unable to sufficiently reduce noise entering the vehicle cabin. Sheet-like soundproofing material made of asphalt-based vibration-damping material alone is unable to sufficiently suppress road noise and tire pattern noise transmitted from the rear tires into the vehicle cabin, making it difficult to achieve a quiet vehicle cabin.

[0014] The acoustic damping panel described in Patent Document 6 has an inflexible, rigid frame, and vibrations are transmitted to the seat via this rigid frame, which may result in insufficient sound insulation. Furthermore, if the support surface on which the rigid frame is placed is curved or uneven, the acoustic damping panel may not be stably supported. In particular, since many of the panels of typical automobiles have curved or uneven surfaces, it is difficult to easily use the acoustic damping panel described in Patent Document 6 as an automotive soundproofing material. Furthermore, rigid frames have a large mass, and the increased mass of the soundproofing material in an automobile poses a problem.

[0015] The soundproofing material described in Patent Document 7 has a high support portion, i.e., a height extending from the seat in a direction perpendicular to the seat, preferably 25 mm or more. In order to stably support the seat with such a high support portion, the support portion preferably has rigidity. As a result, vibrations may be transmitted through the support portion, which may result in insufficient sound insulation, and it may be difficult to mount the soundproofing material on curved or uneven automotive panels. Furthermore, such a high support portion increases the overall size and weight of the soundproofing material. When mounted on an automotive panel, the soundproofing material may occupy a large amount of space inside the vehicle, reducing space efficiency, interfering with the installation of other components, and becoming a nuisance to occupants.

[0016] The sound-insulating material described in Patent Document 8 has a resonating section, which is the functional part that provides sound insulation, exposed and not covered by a supporting wall, etc., and if this resonating section comes into contact with other members or the human body, there is a risk that the sound-insulating properties will be reduced or changed. Therefore, it is necessary to provide a large space around the resonating section, which reduces space efficiency.

[0017] The vibration reduction device described in Patent Document 9 does not have a membrane portion, but consists of multiple vibrators and a frame connecting them. Therefore, like the sound-insulating material of Patent Document 8, the vibrators, which are the functional parts that provide the sound-insulating effect, are exposed, and if other components or the human body come into contact with these vibrators, the sound-insulating properties may be reduced or changed. Furthermore, to ensure a minimum structural strength of the vibration reduction device, the frame must be rigid. As a result, vibrations are transmitted through the frame, which may result in insufficient sound insulation. Furthermore, it is difficult to mount the vibration reduction device described in Patent Document 9 on curved or uneven automotive panels.

[0018] As explained above, the configurations described in Patent Documents 1 to 4 are not intended to prevent noise from tires in contact with the ground from entering the vehicle interior. Furthermore, none of the configurations described in Patent Documents 1 to 5 proposes a new and special structure that effectively insulates sound. Furthermore, none of the configurations described in Patent Documents 1 to 9 provide sufficient sound insulation against noise that enters the vehicle interior, and a soundproof structure with better sound insulation is desired.

[0019] Therefore, an object of the present invention is to provide a soundproofing structure and an automobile soundproofing structure that are thin and lightweight and can be easily and stably mounted on curved or uneven automobile panels while providing sufficient soundproofing properties, and that have good soundproofing properties, particularly against noise in the low frequency range of 1000 Hz or less. [Means for solving the problem]

[0020] The soundproof structure of the present invention is arranged in at least one or both of a position separating a space for accommodating rear tire(s) from a passenger compartment of an automobile and a position separating a space for accommodating front tire(s) from a passenger compartment, and includes a soundproof structure, the soundproof structure having an elastic membrane portion, an elastic support wall portion standing on the membrane portion, and a weight portion standing on the membrane portion, the membrane portion being divided into a plurality of compartments by the support wall portions, the weight portion being located inside all of the plurality of compartments or inside some of the plurality of compartments, each of the weight portions being located in one compartment, the height of the support wall portion extending in a direction perpendicular to the membrane portion being greater than the height of the weight portion extending in a direction perpendicular to the membrane portion, Each of the weight portions constitutes a spring-mass resonator having a spring portion having elasticity and a mass portion having a mass greater than that of the spring portion. The term "elasticity" used here refers to the property of a solid substance that has been deformed by an external force and then returns to its original shape when the external force is removed, and includes energy elasticity and rubber elasticity (entropy elasticity). Here, a substance is said to have "elasticity" if it has 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 a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity. The film portion, the support wall portion, and the spring portion may all have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at 23° C. and a frequency of 1 Hz to 1000 Hz. The film portion, the support wall portion, and the spring portion may all have a loss tangent of 0.01 or more and 0.50 or less at 23° C. and a frequency of 1 Hz to 1000 Hz. Specifically, the elasticity of the membrane, supporting wall, and spring portions is evaluated by measuring frequency dependency in tension or compression mode with a dynamic viscoelasticity measuring device in accordance with JIS K 7244, and determining a master curve based on 23° C., and the dynamic storage modulus (E') is 0.01 MPa or more and 100 MPa or less at 23° C. and frequencies of 1 Hz to 1000 Hz. Even more preferably, the membrane and supporting wall portions each have a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less at 23° C. and frequencies of 1 Hz to 1000 Hz, and a loss tangent of 0.05 to 0.45 at 23° C. and frequencies of 1 Hz to 1000 Hz. The spring portion may be located on the side of the weight portion attached to the membrane portion, and the mass portion may be located on the opposite side of the weight portion from the side attached to the membrane portion. The mass portion may have a larger volume than the spring portion. The mass portion may be made of a material having a higher density than the spring portion. Another soundproof structure of the present invention is arranged in at least one or both of a position separating the space in which rear tires are accommodated from the passenger compartment of an automobile and a position separating the space in which front tires are accommodated from the passenger compartment, and includes a soundproof structure part, the soundproof structure part having an elastic membrane part, an elastic support wall part standing on the membrane part, and a weight part standing on the membrane part, the membrane part is divided into a plurality of compartments by the support wall parts, the weight part is located inside all of the plurality of compartments or inside some of the plurality of compartments, each of the compartments having a weight part located therein has one weight part, the height of the support wall part extending in a direction perpendicular to the membrane part is greater than the height of the weight part extending in the direction perpendicular to the membrane part, the membrane part acts as a spring part, and the weight part acts as a mass part, thereby constituting a spring-mass resonator. Both the membrane portion and the support wall portion may be made of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity. The film portion and the supporting wall portion may both have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23° C. Furthermore, the film portion and the supporting wall portion may both have a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23° C. More preferably, the film portion and the supporting wall portion may both have a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less at a frequency of 1 Hz to 1000 Hz at 23° C., and a loss tangent of 0.05 or more and 0.45 or less at a frequency of 1 Hz to 1000 Hz at 23° C. In the soundproofing structure of the present invention and another soundproofing structure, the support wall portion may include a plurality of first wall portions extending in a direction perpendicular to the membrane portion and extending 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 extending in a second direction perpendicular to the first direction. The support wall portion may be cylindrical with a circular, elliptical or oval cross-sectional shape that defines each of the compartments, or may be rectangular with a polygonal cross-sectional shape that defines each of the compartments, specifically a square, regular pentagon or regular hexagonal cross-sectional shape. The area of ​​each of the compartments is 100 mm 2 More than 1000mm 2 It may be the following: The area of ​​the membrane is 1000 cm 2 More preferably, the membrane portion has an area of ​​1000 cm or more and 1000 or less of the compartments. 2 There may be 50 to 500 of the compartments per unit area. The support wall portion may have a thickness of 0.5 mm or more and 5.0 mm or less. More preferably, the support wall portion may have a thickness of 1.0 mm or more and 3.0 mm or less. The membrane portion may have a thickness of 0.1 mm or more and 3.0 mm or less. The height in the direction perpendicular to the film portion may be 5 mm or more and 20 mm or less. The height of the support wall portion extending from the film portion in a direction perpendicular to the film portion may be 5 mm or more and 20 mm or less, and the height may vary in parts. The height of the weight portion extending from the film portion in a direction perpendicular to the film portion may be 1 mm or more. The film portion may have a durometer A hardness of 50 or more, and the support wall portion may have a durometer A hardness of 1 or more and 90 or less. The durometer A hardness can be obtained by measurement in accordance with JIS K 6253-3. The soundproof structure includes the soundproof structure portion and a soundproof plate-shaped portion, and the soundproof plate-shaped portion may be formed integrally with at least one of the membrane portion and the support plate portion, or may be joined to each other and positioned alongside the soundproof structure portion in a plane. The area of ​​the main surface of the soundproof structure occupied by the soundproof structural portion may be 5% to 95% of the area of ​​the entire soundproof structure. The soundproof structure may be attached to a panel inside a vehicle (including an internal combustion vehicle, an electric vehicle, a fuel cell vehicle, and a hybrid vehicle), and in particular may be attached to a panel inside an electric vehicle. In the automobile soundproofing structure of the present invention, the soundproofing structures having the above-described configuration are attached to the dash panel and the rear floor, respectively. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a soundproof structure and an automobile soundproof structure that are thin and lightweight and can be easily and stably mounted on curved or uneven automobile panels while providing sufficient soundproofing, and that have particularly good sound insulation in the low frequency range of 1000 Hz or less. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view of an automobile provided with a soundproof structure according to a first embodiment of the present invention. [Figure 2]FIG. 1 is a front view of one soundproof structure according to a first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of a modified example of the soundproof structure shown in FIG. [Figure 5] FIG. 2 is a perspective view of another soundproof structure according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a side view of the soundproof structure shown in FIG. 5. [Figure 7] FIG. 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 8] 1A is a perspective view of a soundproof structure of the present invention, and FIG. 1B is a cross-sectional view taken along line CC thereof. [Figure 9] 9(A) is an exploded perspective view of one section of the soundproof structure shown in FIG. 8, and FIG. 9(B) is an exploded front view thereof. [Figure 10] 1A is a perspective view of another example of the soundproof structure of the present invention, and FIG. 1B is a cross-sectional view taken along line CC thereof. [Figure 11] 1A is a perspective view of a modified example of the soundproof structure of the present invention, and FIG. 1B is a cross-sectional view taken along line CC thereof. [Figure 12] FIG. 1(A) is a plan view schematically showing one section of a soundproof structure of the present invention, and FIG. 1(B) is a plan view schematically showing a plurality of sections. [Figure 13] 1 is a cross-sectional view showing a state in which a sound-insulating structure according to a first embodiment of the present invention is attached to an iron plate. [Figure 14] Graphs (A) to (F) show the sound insulation properties of Examples 1 to 8 of the present invention and Comparative Examples 1 to 4. [Figure 15] Graphs (A) to (E) show the sound insulation properties of Examples 1 and 8 to 14 of the present invention and Comparative Examples 5 and 6. [Figure 16] FIG. 1 is a cross-sectional view of the structure of Comparative Example 1. [Figure 17] 10(A) is a perspective view of the sound insulating structure of Comparative Example 3, and FIG. 10(B) is a cross-sectional view showing the sound insulating structure attached to an iron plate. [Figure 18] FIG. 10 is a cross-sectional view showing a state in which a sound-insulating structure according to a second embodiment of the present invention is attached to an iron plate. [Figure 19] FIG. 10(A) is a perspective view of a sound insulating structure according to a third embodiment of the present invention, and FIG. 10(B) is a cross-sectional view showing the sound insulating structure attached to an iron plate. [Figure 20] 6A is a perspective view of a sound insulating structure according to a sixth embodiment of the present invention, and FIG. 6B is a cross-sectional view showing the sound insulating structure attached to an iron plate. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] FIG. 1 shows a side view of an automobile 1 provided with soundproof structures 8 and 9 according to a first embodiment of the present invention. In this automobile 1, a soundproof structure 8 of the present invention is arranged so as to overlap a panel (rear floor) 17 provided at the boundary between a space 12 in which a rear tire 11 is accommodated and a passenger compartment 13. In addition, another soundproof structure 9 is arranged so as to overlap a panel (dash panel) 16 provided at the boundary between a space 15 in which a front tire is accommodated and the passenger compartment 13. The panel referred to here is a general term for a plate-like member located inside the automobile 1 and includes a part of the frame, chassis, etc. However, the soundproof structures 8 and 9 may be arranged on a member other than the panels 16 and 17. This automobile 1 may be an engine vehicle, an electric vehicle, a fuel cell vehicle, a hybrid vehicle, etc.

[0024] Fig. 2 is a front view of a soundproofing structure 8 provided at the boundary between a space 12 in which a rear tire 11 is accommodated and the vehicle interior 13, as seen from the vehicle interior 13 side, and Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. Fig. 4 is a cross-sectional view of a modified example of the soundproofing structure 8. Fig. 5 is a perspective view of a soundproofing structure 9 provided at the boundary between a space 15 in which a front tire is accommodated and the vehicle interior 13, as seen from the vehicle interior 13 side, Fig. 6 is a side view thereof, and Fig. 7 is a cross-sectional view taken along line BB in Fig. 5. A panel 16 located in the front of the vehicle interior 13 and covering part of the space 15 in which the front tire is accommodated is usually called a dash panel, and the soundproofing structure 9 is arranged to overlap this panel 16.

[0025] The soundproof structure 8 provided on the side of the space 12 where the rear tire 11 is accommodated and the soundproof structure 9 provided on the side of the space 15 where the front tire is accommodated each comprise soundproof structures 8a, 9a and soundproof plate-like structures 8b, 9b, respectively. In this embodiment, the large-area soundproof plate-like portion 8b, 9b and the two soundproof structures 8a, 9a located on either side of it are integrally formed or joined together to form the soundproof structures 8, 9, which can be handled as a single component. In the configuration shown in FIG. 3, the soundproof plate-like portion 8b and the two soundproof structure portions 8a are positioned side by side in a plane. However, as shown in a modified example in FIG. 4, two soundproof structure portions 8a may be stacked on the soundproof plate-like portion 8b. Although not shown, the soundproof structure 9 may also have a configuration in which two soundproof structure portions 9a are stacked on the soundproof plate-like portion 9b, similar to the configuration shown in FIG. 4.

[0026] In these soundproofing structures 8, 9, soundproofing structures 8a, 9a are arranged in areas of the automobile 1 where sound propagation is particularly strong. For example, in the soundproofing structure 9 arranged so as to overlap a panel 16 located at the boundary between a space 15 that houses the front tires and the passenger compartment 13, soundproofing structures 9a are arranged in two locations facing the front tires, which are areas where propagation of road noise and tire pattern noise is particularly strong.

[0027] The soundproofing plate portions 8b, 9b may be made of materials similar to existing soundproofing materials, such as a single-layer structure consisting of a layer of sound-absorbing material (e.g., felt, polyurethane foam, or glass wool) and a layer of sound-insulating material (e.g., resin film or rubber sheet), or a laminated structure of these. These materials may be made from biomass materials. The soundproofing plate portions 8b, 9b are plate-shaped members shaped to fit the panels 16, 17 and may have different thicknesses depending on the area. For example, the soundproofing plate portions 8b, 9b may have thicknesses ranging from thin portions less than 5 mm to thick portions approximately 40 mm. The soundproofing plate portions 9b may have a configuration substantially similar to or similar to the dash silencers described in Patent Documents 1 and 2.

[0028] The sound-insulating structure 8a of the sound-insulating structure 8 and the sound-insulating structure 9a of the sound-insulating structure 9 may have the same structure. Specific structural examples of these sound-insulating structures 8a, 9a are shown in FIGS. 8 and 9. FIG. 8(A) is a perspective view of the sound-insulating structures 8a, 9a, and FIG. 8(B) is a cross-sectional view taken along line CC in FIG. 8(A) and inverted. FIG. 9(A) is an exploded perspective view of one section 5 of the sound-insulating structures 8a, 9a shown in FIG. 8, and FIG. 9(B) is an exploded front view thereof. The sound-insulating structures 8a, 9a each have an elastic sheet-like film 2, an elastic support wall 3 standing substantially perpendicular to the film 2, and a weight 4 standing substantially perpendicular to the film 2. The film 2 is divided into multiple sections (unit structures) 5 by the support wall 3. The weight 4 is located inside all of the multiple sections 5 or inside some of the multiple sections 5. In the compartments 5 in which the weights 4 are located, one weight 4 is located within one compartment 5. The height H1 of the support wall 3, which extends from the membrane 2 in a direction perpendicular to the membrane 2, is greater than the height H2 of the weight 4, which extends from the membrane 2 in a direction perpendicular to the membrane 2. Each weight 4 constitutes a spring-mass resonator having an elastic spring 4a and a mass 4b having a larger mass than the spring 4a. The term "elasticity" as used here refers to the property of a solid material that has been deformed by an external force and returns to its original shape when the external force is removed, and includes energy elasticity and rubber elasticity (entropy elasticity). Here, the term "having elasticity" refers to the presence of at least one of energy elasticity and rubber elasticity (entropy elasticity). The sound-insulating structure shown in Figures 8-9, etc. can be used in both the sound-insulating structure 8 on the side of the space 12 where the rear wheel tire 11 is accommodated, as shown in Figures 2-4, and the sound-insulating structure 9 on the side of the space 15 where the front wheel tire is accommodated, as shown in Figures 5-7, and therefore the sound-insulating structure shown is given both the symbol 8a and the symbol 9a.

[0029] The support wall 3 of the sound-insulating structure 8a, 9a of this embodiment includes a plurality of first walls 3a extending in a first direction D1 parallel to the membrane 2 and a plurality of second walls 3b extending in a second direction D2 perpendicular to the first direction D1. Specifically, the plurality of first walls 3a are arranged in parallel, and the plurality of second walls 3b are arranged in parallel, with the first walls 3a and the second walls 3b being integrated at their intersections. The plurality of first walls 3a and the plurality of second walls 3b thus form a lattice structure, and a plurality of compartments 5, each having a square planar shape and partitioned by the first walls 3a and the second walls 3b, are arranged in a matrix. In other words, the support wall 3 is structured by arranging a plurality of rectangular tubes having a square cross section, each defining an individual compartment 5. The support wall 3 is preferably made of a flexible material such as rubber, elastomer, or resin foam. The flexible material referred to here is any of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, and a material that has both rubber elasticity and energy elasticity.

[0030] 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 larger mass than the spring portion 4a. In the example shown in Figures 7 and 8, 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 constituting the spring portion 4a. A spring-mass resonator is constructed in which the spring portion 4a functions as a spring and the mass portion 4b functions as a mass. Note that in addition to the spring portion 4a of the weight portion 4, the membrane portion 2 may also function as part of the spring of the spring-mass resonator. Furthermore, the air in the space surrounded by the membrane portion 2 and the support wall portion 3 may function as part of the spring of the spring-mass resonator (an air spring). It is preferable that the spring portion 4a is also made of a flexible material, i.e., a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity.

[0031] According to the sound-insulating structural parts 8a, 9a of the soundproof structures 8, 9 of this embodiment, the vibration of the membrane part 2 is controlled by the action of a spring-mass resonator formed by the spring part 4a and mass part 4b of the weight part 4. In particular, in a specific frequency range (for example, frequencies below 1000 Hz, which are the main frequency bands of road noise and tire pattern noise in automobile 1), membrane vibration is significantly reduced, resulting in a reduction in the sound radiated from the membrane part 2 and a high level of sound insulation.

[0032] In this embodiment, the sound-insulating structure sections 8a and 9a have a section 5 with a membrane section 2 of 1000 cm 2 Preferably, 10 to 1000 compartments are provided per 1000 cm2 of the membrane part 2, and more preferably, 50 to 500 compartments are provided per 1000 cm2 of the membrane part 2. 2 By providing 10 or more sections per membrane part 2, the entire sound insulating structure parts 8a, 9a can be divided into a plurality of sections 5, and sound insulating effect can be exerted for each section 5, thereby improving the sound insulating properties of the entire sound insulating structure parts 8a, 9a. 2 By limiting the number of pieces to 1000 or less per section, the increase in the weight of the entire sound insulating structure 8a, 9a can be suppressed. 2 More than 1000mm 2 Preferably, it is less than 200 mm 2 Over 800mm 2 It is more preferable that the area of ​​the planar shape of each of the sections 5 is 100 mm or less. 2 Therefore, it is easy to arrange the weight part 4 inside, and on the other hand, the area is 1000 mm 2Because the height is less than or equal to 5 mm, the effect of the weight 4 on the membrane 2 is large, resulting in high sound insulation. The height of the entire sound insulation structures 8a, 9a in the direction perpendicular to the membrane 2 is preferably 5 mm or more and 20 mm or less. When the height of the entire sound insulation structures 8a, 9a is 5 mm or more, the weight 4 can have a sufficient height as a spring-mass resonator, and when the height is 20 mm or less, an increase in the weight of the entire sound insulation structures 8a, 9a is suppressed. Note that each drawing shows each compartment 5 and support wall 3, etc., schematically, and the number and area of ​​compartments 5 and the height of support wall 3 may not be shown strictly accurately or may not be consistent across drawings. However, it is preferable that the number and area of ​​compartments 5 and the height of support wall 3 are appropriately designed so that they are within the aforementioned numerical ranges.

[0033] The membrane 2, support wall 3, and spring 4a of the soundproof structures 8a and 9a of the soundproof structures 8 and 9 of this embodiment are all made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa to 100 MPa at 23°C and a frequency of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 to 0.50 at 23°C and a frequency of 1 Hz to 1000 Hz, preferably 0.05 MPa to 50 MPa at 23°C and a loss tangent (tanδ) of 0.05 to 0.50 at 23°C and a frequency of 1 Hz to 1000 Hz, respectively. 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 in the frequency range of 1 Hz to 1000 Hz is 0.01 MPa or more, sound insulation in the target frequency band is good, and the shape retention of the film 2 and the support wall 3 is good. Since the dynamic storage modulus (E') at 23°C in the frequency range of 1 Hz to 1000 Hz is 100 MPa or less, vibration in the target frequency band is good, and the sound-insulating structures 8a, 9a do not become rigid, allowing for good installation of the soundproof structures 8, 9. The film 2 and the support wall 3 may be made of the same material or different materials. It is preferable that the film 2 is also made of a flexible material, i.e., a material that has rubber elasticity but no energy elasticity, a material that has energy elasticity but no rubber elasticity, or a material that has both rubber elasticity and energy elasticity.

[0034] Since the weight 4 is attached to the film 2, it is preferable that the film 2 be a hard elastic film. The dynamic storage modulus (E') of the film 2 is preferably 15 MPa or more, and the thickness (film thickness) is preferably 0.1 mm to 3.0 mm, more preferably approximately 0.5 mm. When the film 2 is 0.1 mm or more, sufficient thickness is ensured, making it easy to handle. When the film 2 is 3.0 mm or less, the thickness and weight of the sound-insulating structures 8a, 9a as a whole are suppressed, and the sound-insulating structures 8a, 9a as a whole do not become too hard, making installation easy. The material of the film 2 preferably has a durometer A hardness according to JIS K6253 of 50 or more, more preferably 70 or more. By setting the durometer A hardness of the film 2 within the above range, deterioration of the vibration of the film 2 is prevented, and sound insulation in the target frequency band is improved. The rigidity (axial rigidity) k of the membrane part 2 is expressed as k = E' × A / L using the dynamic storage modulus E', the cross-sectional area A of the membrane part 2, and the thickness L of the membrane part 2. When the area of ​​the membrane part 2 to be evaluated for rigidity is 1000 cm 2 When the stiffness k is 10 6 N / mm or more 10 9 N / mm or less is preferable, and 3×10 6 N / mm or more 10 8 It is more preferable that the surface area of ​​the film portion 2 is 1000 cm or less. 2 When the stiffness is 10 6 When the surface area of ​​the film 2 is 1000 cm or more, the deterioration of the vibration of the film 2 can be suppressed, and the sound insulation performance in the frequency band to be insulated can be improved. 2 When the stiffness is 10 9 When the sound insulation structure parts 8a, 9a are flexible, the sound insulation structures 8a, 9a can be easily installed, and the sound insulation structures 8, 9 can be easily installed. The bending rigidity K of the film part 2 is expressed as K=E'×I from the dynamic storage modulus E' and the second moment of area I, and the second moment of area I is expressed as I=b×h from the thickness h of the film part 2 and the width b of the film part 2. 3 When the area of ​​the membrane part 2 to be evaluated is 1000 cm 2 When the bending stiffness K is 1N / mm 2 Over 10 5 N / mm 2Preferably, it is 10 N / mm or less. 2 5x10 or more 4 N / mm 2 It is more preferable that the area of ​​the membrane portion 2 is 1000 cm or less. 2 When the bending stiffness K is 1N / mm 2 By satisfying the above, the vibration of the film part 2 is improved, and it is possible to suppress deterioration of the sound insulation performance in the frequency band to be insulated. 2 When the bending stiffness K is 10 5 N / mm 2 By satisfying the following, the soundproof structures 8a, 9a become flexible and improve the installation properties of the soundproof structures 8, 9. The cross-sectional shape of the film portion 2 is not particularly limited, and may be flat or may have irregularities.

[0035] Materials for the film portion 2 include cross-linked (vulcanized) rubber, thermoplastic elastomer, and plastic. Examples of crosslinked (vulcanized) rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), ethylene-α-olefin-non-conjugated polyene copolymers such as 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 methylvinylsilicone rubber (VMQ) and fluorinated silicone rubber (FVMQ), urethane rubber (U), and fluororubber (FKM). These crosslinked (vulcanized) rubbers can be used alone or in combination of two or more. Examples of crosslinking (vulcanization) methods include a method of crosslinking (vulcanization) by heating using a crosslinking agent (vulcanizing agent) such as an organic peroxide, a phenolic resin, an oxime compound, sulfur, a sulfur-based compound, or a polyamine compound, or a method of crosslinking by irradiating with an electron beam. The crosslinked (vulcanized) rubber may contain various known compounding agents commonly used as rubber compounding agents (reinforcing agents such as carbon black and silica, fillers such as calcium carbonate, softeners such as paraffin oil and plasticizers, processing aids, antioxidants, light stabilizers, flame retardants, mildew inhibitors, acid acceptors, silane coupling agents, antistatic agents, ultraviolet absorbers, etc.). These crosslinked (vulcanized) rubbers, crosslinking agents (vulcanizing agents), and compounding agents may be made from biomass materials.

[0036] Examples of thermoplastic elastomers include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, ethylene-vinyl acetate-based thermoplastic elastomers, and thermoplastic polyurethanes. Examples of plastics include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, and composite resins containing these. These thermoplastic elastomers and plastics may be made from biomass raw materials.

[0037] Specifically, the material of the film portion 2 is preferably ethylene-propylene-diene rubber, thermoplastic olefin-based elastomer, thermoplastic styrene-based elastomer, polyethylene, polypropylene, polyethylene terephthalate, thermoplastic polyurethane, or the like.

[0038] The support wall 3 is preferably made of a flexible material that is soft enough to support the membrane 2. The thickness of the support wall 3 is preferably 0.5 mm to 5.0 mm, and more preferably 1.0 mm to 3.0 mm. Having a thickness of 0.5 mm or more improves the shape retention of the sound-insulating structures 8a, 9a. Having a thickness of 5.0 mm or less improves the vibration of the membrane 2, improves sound insulation in the target frequency band, and minimizes the increase in the overall weight of the sound-insulating structures 8a, 9a. The height of the support wall 3 in a direction perpendicular to the membrane 2 is preferably 5 mm to 20 mm, and more preferably 10 mm to 20 mm. The support wall 3 may have different heights in parts. If the height of the support wall 3 varies in parts, the higher part may be 10 mm to 20 mm, more preferably 12 mm to 20 mm, and even more preferably 14 mm to 20 mm. By ensuring that the height of the support wall portion 3 is not too low, the weight portion 4 can have a sufficient height as a spring-mass resonator. By ensuring that the height of the support wall portion 3 is not too high, the overall weight can be reduced. The material of the support wall portion 3 preferably has a durometer A hardness according to JIS K6253 of 1 or more and 90 or less, and more preferably 10 or more and 70 or less. By ensuring that the durometer A hardness of the support wall portion 3 is 1 or more, the shape retention of the soundproof structures 8a, 9a can be maintained. By ensuring that the durometer A hardness of the support wall portion 3 is 90 or less, vibrations from the support wall portion 3 can be prevented from being transmitted to the membrane portion 2, which would deteriorate the soundproofing performance, and the soundproof structures 8a, 9a become flexible, improving the installability of the soundproof structures 8, 9. The stiffness k of the support wall 3 is expressed as k = E' × A / L using the dynamic storage modulus E', the cross-sectional area A of the support wall 3, and the height L of the support wall 3. When the area of ​​the support wall 3 to be evaluated for stiffness is 1000 cm 2 When the stiffness k is 10N / mm or more, 6 N / mm or less is preferable, and 10 2 N / mm or more 10 5 It is more preferable that the area of ​​the support wall 3 is 1000 cm or less. 2When the area of ​​the support wall 3 is 1000 cm, the stiffness k is 10 N / mm or more, so that the shape retention of the sound insulating structures 8a and 9a can be maintained. 2 When the stiffness k is 10 6 By keeping the resistance at N / mm or less, vibrations from the support wall portion 3 are prevented from being transmitted to the membrane portion 2, which would deteriorate the sound insulation performance, and the sound insulation structure portions 8a, 9a do not become rigid, which makes it easy to install the soundproof structures 8, 9.

[0039] 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 those listed as materials for the membrane portion 2. The resin foams may have either 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 materials for the support wall portion 3 are preferably ethylene-propylene-diene rubber, urethane rubber, silicone rubber, thermoplastic olefin-based elastomers, thermoplastic styrene-based elastomers, thermoplastic polyurethane, and polyurethane foam. These resin foams may be made from biomass materials.

[0040] 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 as the materials of the support wall portion 3. Specifically, the material of the spring portion 4a of the weight portion 4 is preferably ethylene-propylene-diene rubber, urethane rubber, silicone rubber, thermoplastic olefin-based elastomer, thermoplastic styrene-based elastomer, thermoplastic polyurethane, or polyurethane foam. These materials may be made from biomass raw materials.

[0041] The material of the mass portion 4b is not particularly limited, but it may be made of resin, metal, or the like, and the mass portion 4b has a larger mass than the spring portion 4a, for example, a mass of 0.1 g or more and 2.0 g or less. The mass portion 4b preferably has a mass at least twice the mass of the spring portion 4a. By making the weight of the mass portion 4b at least twice the mass of the spring portion 4a, the weight portion 4 can be made to resonate sufficiently in the frequency range to be sound-insulated, thereby achieving a good sound-insulating effect. When the material of the mass portion 4b is resin, the resin may be made from a biomass material.

[0042] The spring constant (rigidity) of the spring portion 4a is determined based on the mass of the mass portion 4b so that the resonant frequency coincides with the frequency that is the main target of sound insulation. For example, if the mass of the mass portion 4b is 1.0 g and the main target frequency of sound insulation is 1000 Hz or less, the spring constant of the spring portion 4a is 1 N / mm or more and 50 N / mm or less.

[0043] With this configuration, the film portion 2, the support wall portion 3, and the weight portion 4 are all relatively light in weight, and the dimensions in the direction perpendicular to the film portion 2 are relatively small. As described above, the soundproof structures 8, 9 of this embodiment are lightweight and thin, yet provide high sound insulation in a specific frequency range (for example, frequencies below 1000 Hz, which are the main frequency bands of road noise and tire pattern noise in an automobile 1), as described above. Furthermore, the support wall portion 3 made of a flexible material can be easily and stably installed on a flat panel 16 or the like, or on a panel 16 with a curved or uneven surface, without being fixed by adhesive or the like.

[0044] The sound-insulating structure 8a of the sound-insulating structure 8 of this embodiment is disposed in a position separating the space 12 housing the rear tires 11, which are a region of the automobile 1 where sound propagation is particularly strong, from the passenger compartment 13. Similarly, in this embodiment, the sound-insulating structures 9a are disposed on both the left and right sides of the space 15 housing the front tires, i.e., in positions adjacent to the front tires 14, which are regions where sound propagation is particularly strong. If the entire sound-insulating structure 8 or the entire sound-insulating structure 9 were formed as the sound-insulating structure 8a or the sound-insulating structure 9a, the sound-insulating effect would be high, but the weight of the sound-insulating structures 8 and 9 would be large, which could adversely affect the performance of the automobile 1. In contrast, in this embodiment, the sound-insulating structure 8a with a high sound-insulating effect is disposed in a position facing the rear tires 11, which are a region where sound propagation is particularly strong, and the sound-insulating structure 9a with a high sound-insulating effect is disposed in a position adjacent to the front tires 14, which are also a region where sound propagation is particularly strong. Furthermore, soundproofing plate-like portions 8b, 9b with a simple structure are arranged in areas where sound propagation is not so strong. This makes it possible to efficiently suppress sound penetration while minimizing weight increases. Furthermore, the soundproofing structures 8, 9 can be easily and stably installed on panels of various shapes without the need for adhesive or other fastening. Therefore, the soundproofing structures 8, 9 of this embodiment can be stacked on panels of complex shapes and stably held in place.

[0045] Furthermore, the sound-insulating structures 8a, 9a of this embodiment are integrated with the sound-insulating plate-shaped members 8b, 9b, which are similar to existing sound-insulating materials. This eliminates the need for additional components and simplifies installation. The sound-insulating structures 8a, 9a and the sound-insulating plate-shaped members 8b, 9b can be integrated by insert molding or other methods, such as integrally molding a layer of sound-insulating material (e.g., felt, urethane, glass wool) or a layer of sound-insulating material (e.g., resin film, rubber sheet) that constitutes the sound-insulating plate-shaped members 8b, 9b with at least one of the membrane member 2 and the support wall member 3 of the sound-insulating structures 8a, 9a. Alternatively, ultrasonic welding, bonding with a hot-melt adhesive, or fastening with clips, bolts, or rivets can be used. This allows for easy handling of the sound-insulating structures 8a, 9, each consisting of the sound-insulating plate-shaped members 8b, 9b and the sound-insulating structures 8a, 9a. The sound-insulating structural parts 8a, 9a may be exposed inside the vehicle interior 13, but may also be covered with a sheet material (not shown) or the like so that the sound-insulating structural parts 8a, 9a are not exposed inside the vehicle interior 13.

[0046] In this embodiment, the lightweight and thin soundproofing structures 8, 9 provide high sound insulation in a specific frequency range (for example, frequencies below 1000 Hz, which are the main frequency bands for road noise and tire pattern noise in the automobile 1), and can be easily installed without the need for adhesive. In particular, they can efficiently block noise from the space 12 that houses the rear tire 11, which has a large sound propagation, and noise from the space 15 that houses the front tire, from entering the vehicle interior 13, resulting in a high soundproofing effect. However, a configuration in which only one of the soundproofing structure 8 located at a position separating the space 12 that houses the rear tire 11 from the vehicle interior 13 and the soundproofing structure 9 located at a position separating the space 15 that houses the front tire from the vehicle interior 13 also provides a fairly high sound insulation effect, and is an example of a configuration according to the present invention.

[0047] On one main surface of the soundproofing structures 8, 9 (the surface facing the vehicle interior 13, which is the wide surface mainly shown in FIGS. 2 and 5), the area occupied by the planar shape of the soundproofing structures 8a, 9a is preferably 5% to 95% of the area of ​​the planar shape of the entire soundproofing structures 8, 9, more preferably 10% to 40% and even more preferably 20% to 30%. When the area proportion occupied by the soundproofing structures 8a, 9a is 5% or more, sufficient sound insulation for the soundproofing structures 8, 9 can be obtained. Furthermore, when the area proportion occupied by the soundproofing structures 8a, 9a is 95% or less, noise propagating through the soundproofing structures 8, 9 toward the vehicle interior 13 is reflected by the panel, hits a surface of the soundproofing structures 8, 9 that is not laminated with sound-absorbing material, and is then reflected again, which increases the sound pressure and prevents muffled noise.

[0048] The specific structures of the sound-insulating structures 8a, 9a of the sound-insulating structures 8, 9 of this embodiment are not limited to those shown in FIGS. 8 and 9 . Modifications of the sound-insulating structures 8a, 9a of this embodiment are described below. In the modifications described below, the spring portion 4a and the mass portion 4b of the weight portion 4 of the sound-insulating structures 8a, 9a have different shapes and dimensions. FIG. 10(A) is a perspective view showing a modification of the sound-insulating structures 8a, 9a of the sound-insulating structures 8, 9 of this embodiment, and FIG. 10(B) is a cross-sectional view taken along line CC in FIG. 10(A) and inverted upside down. In the example shown in FIG. 10 , the spring portion 4a is cylindrical with a small diameter, and the mass portion 4b is cylindrical with a large diameter. Although not shown, the spring portion 4a may be elongated and cylindrical, 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 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 larger mass than the spring portion 4a, thereby constituting a spring-mass resonator. However, in these examples, the spring portion 4a and the mass portion 4b may be made of different materials, and the mass portion 4b may have a larger mass than the spring portion. Also, although not shown, the spring portion 4a may be truncated conically and the mass portion 4b may be cylindrically shaped, with the diameter of the smallest part of the truncated conical spring portion 4a substantially equal to the diameter of the cylindrical mass portion 4b. In this 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 larger mass than the spring portion, thereby constituting a spring-mass resonator. As in this example, if the spring portion 4a has a truncated cone shape tapering away from the membrane portion 2, it can be easily released from a mold 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 the shapes shown in Figures 8 to 10 and various other shapes not shown can be used. The weight portion 4 is formed in any shape and dimensions selected so as to satisfy the performance of the spring-mass resonator required for sound insulation and to be able to be housed within the compartment 5.

[0049] In the sound-insulating structures 8a and 9a of the sound-insulating structures 8 and 9 shown in Figures 5 to 10, the spring portion 4a and the mass portion 4b of the weight portion 4 are made of different materials and / or different volumes, thereby making the mass portion 4b larger in mass than the spring portion 4a, thereby forming a spring-mass resonator and achieving a sufficient sound-insulating effect. In other words, the materials, shapes, and dimensions of the spring portion 4a and the mass portion 4b are determined so that a spring-mass resonator that can provide a sufficient sound-insulating effect can be formed. The materials, shapes, 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 can be made larger than the spring portion 4a to the extent that a spring-mass resonator that can provide a sufficient sound-insulating effect can be formed. However, the spring portion 4a must be made of a flexible material in order to function as a spring.

[0050] [Second embodiment] FIG. 11(A) is a perspective view showing sound insulating structures 8a and 9a of soundproof structures 8 and 9 according to a second embodiment of the present invention, and FIG. 11(B) is a cross-sectional view taken along line CC in FIG. 11(A) and turned upside down. These sound insulating structures 8a and 9a have a weight portion 7 that is a single structure that is not divided into a spring portion and a mass portion. In these sound insulating structures 8a and 9a, the entire weight portion 7 functions as the mass portion, and a spring-mass resonator is formed in which the film portion 2 functions as the spring portion. As an example, the mass of the weight portion 7 is approximately 0.1 g to 2.0 g. The material of the weight portion 7 is not limited, and it may be made of, for example, synthetic resin or metal. The rest of the configuration is the same as that of the first embodiment, and therefore a description thereof will be omitted. In the sound insulation structures 8a and 9a of this embodiment, membrane vibration is also controlled by the action of the spring mass resonator formed by the weight portion 7 and the membrane portion 2, and membrane vibration is significantly reduced in a specific frequency range (for example, 1000 Hz or less), thereby providing high sound insulation. Note that, together with the membrane portion 2, 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 (air spring) of the spring mass resonator.

[0051] In this embodiment, the film part 2 and the supporting wall part 3 both preferably have a dynamic storage modulus of 0.01 MPa or more and 100 MPa or less at a frequency of 1 Hz to 1000 Hz at 23° C., and a loss tangent of 0.01 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23° C. Furthermore, it is more preferable that the film part 2 and the supporting wall part 3 both have a dynamic storage modulus (E') of 0.05 MPa or more and 50 MPa or less at a frequency of 1 Hz to 1000 Hz at 23° C., and a loss tangent (tanδ) of 0.05 or more and 0.50 or less at a frequency of 1 Hz to 1000 Hz at 23° C.

[0052] The support wall 3 of this embodiment is made of any one of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, and a material that has both rubber elasticity and energy elasticity. Similarly, the membrane 2 of this embodiment is made of any one of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, and a material that has both rubber elasticity and energy elasticity.

[0053] Although not shown, in a modified example of the sound insulating structure parts 8a, 9a of the soundproof structures 8, 9 of this embodiment, the weight part 7 has a truncated cone shape that tapers in a direction away from the film part 2. With this configuration, the weight part 7 can be easily released from a mold when the film part 2 and the weight part 7 are integrally molded. In this modified example, the shape of the weight part 7 can be determined arbitrarily and is not particularly limited.

[0054] In the sound-insulating structures 8a, 9a of the soundproof structures 8, 9 of any of the first and second embodiments described above, the film 2 and the support wall 3 can be formed by integral molding or two-color molding using the above-mentioned materials, such as injection molding, compression molding, press molding, extrusion molding, transfer molding, or cast molding. Furthermore, at least a portion of the weights 4, 7 can also be formed together with the film 2 and the support wall 3 by integral molding, two-color molding, or insert molding using the above-mentioned materials. However, the sound-insulating structures 8a, 9a may also be assembled by forming the film 2, the support wall 3, and the weights 4, 7 separately and then joining them together by adhesive or heat fusion.

[0055] In the sound-insulating structures 8a and 9a described above, as shown in FIGS. 12(A) and 12(B), the support wall 3 includes a plurality of first walls 3a extending in a first direction D1 parallel to the membrane 2 and a plurality of second walls 3b extending in a second direction D2 perpendicular to the first direction D1, and each compartment 5 has a square planar shape. In other words, the support wall 3 is a rectangular tube having a square cross-section that defines each compartment 5, and a large number of rectangular support walls 3 are arranged side by side, with the support walls 3 of adjacent compartments 5 being integrated. However, this configuration is not limited to this. For example, although not shown, the planar shape of each compartment 5 may be triangular, and the support wall 3 may be a rectangular tube having a triangular cross-section that defines each compartment 5. Alternatively, although not shown, the planar shape of each compartment 5 may be pentagonal, and the support wall 3 may be a rectangular tube having a pentagonal cross-section that defines each compartment 5. Although not shown, the planar shape of each compartment 5 may be hexagonal, and the support wall 3 may be a rectangular tube with a hexagonal cross-section that defines each compartment 5, forming a so-called honeycomb structure. Furthermore, although not shown, the planar shape of each compartment 5 may be circular, and the support wall 3 may be a cylinder with a circular cross-section that defines each compartment 5. When the planar shape of each compartment 5 is pentagonal or circular, gaps will form between the compartments 5. Therefore, it is preferable to determine the shape and dimensions of the support wall 3 so as to minimize these gaps, and it is preferable that the membrane 2 expands to close the gaps. When the planar shape of each compartment 5 is triangular, quadrangular, or hexagonal, no gaps will form between the compartments 5. Furthermore, each compartment 5 may have various shapes (not shown), such as a rectangle, parallelogram, trapezoid, polygon with seven or more sides, ellipse, oval, etc., or may be an irregular shape. The support wall 3 is formed to a shape and dimensions that match the planar shape of each compartment 5.

[0056] The soundproof structures 8 and 9 of the present invention are thin and lightweight, and are used by being placed on a curved or uneven panel of an automobile 1 (for example, panel 16 shown in FIG. 1 ). The panel of the automobile 1 is basically a non-porous plate, and examples thereof include a metal plate (iron plate, steel plate, aluminum plate) and a resin plate. When the panel on which the soundproof structures 8 and 9 are placed is a metal plate, its thickness is preferably in the range of 0.5 mm to 2.0 mm, and when it is a resin plate, its thickness is preferably in the range of 0.5 mm to 20 mm. It is preferable that the end face of the support wall portion 3 of the soundproof structures 8 and 9 opposite to the side attached to the film portion 2 is placed on the panel of the automobile 1. In this case, the support wall portion 3 of the soundproof structures 8 and 9 and the panel may or may not be bonded, but it is preferable that the support wall portion 3 is placed on the panel without being bonded to the panel. [Example]

[0057] Specific examples and comparative examples of the sound insulating structural parts 8a, 9a of the sound insulating structures 8, 9 of the present invention will be described below. [Example 1] The soundproof structural members 8a, 9a of the soundproof structures 8, 9 of Example 1 of the present invention have the same structure as that of the first embodiment shown in Figures 8 and 9. The film member 2 is made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at 23°C and at a frequency of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 or more and 0.50 or less at 23°C and at a frequency of 1 Hz to 1000 Hz. More specifically, the film part 2 of this example has a dynamic storage modulus (E') of 20.4 MPa and a 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 a 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 a loss tangent (tanδ) of 0.16 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 28.8 MPa and a 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, and is made of EPDM (ethylene-propylene-diene rubber). The planar shape of this film part 2 has an area of ​​1000 cm. 2 If the square is , the bending stiffness K is 67.2N / mm 2 The planar shape has an area of ​​400 cm 2 If the square is , the bending stiffness K is 42.5N / mm 2 If the same material as the film portion 2 is used, the film thickness is 3 mm, and the plane shape has an area of ​​1000 cm 2 When a square membrane is formed, its bending stiffness K is approximately 1.5 × 10 4 N / mm 2 is.

[0058] The support wall portion 3 of this embodiment is made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at 23°C and at a frequency of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 or more and 0.50 or less at 23°C and at a frequency of 1 Hz to 1000 Hz. More specifically, the support wall portion 3 of this example has 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, and 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 according to JIS K6253 of 65, a plate thickness of 1.6 mm, and a height of 10 mm in the direction perpendicular to the membrane portion 2. However, only the outermost support wall portion 3 has a plate thickness of half that, 0.8 mm. The compartments 5 defined by the multiple support walls 3 (first wall 3a and second wall 3b) are square, measuring 25 mm x 25 mm, and there are 49 compartments 5 in the 200 mm x 200 mm square area (evaluation surface) of the membrane 2. However, only a portion of this area is shown schematically in the drawing. The weight 4 is cylindrical, with a diameter of 6 mm and a height (dimension in the direction perpendicular to the membrane 2) of 6 mm.

[0059] Of this weight portion 4, the spring portion 4a, which is the portion attached to the membrane portion 2, is 3 mm high and is made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at 23°C and at frequencies of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 or more and 0.50 or less at 23°C and at frequencies of 1 Hz to 1000 Hz. More specifically, spring portion 4a in this embodiment has 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 100 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, and is made of silicone rubber with a durometer A hardness of 10 according to JIS K6253. Mass portion 4b, which is the portion of weight portion 4 opposite the side attached to membrane portion 2, also has a height of 3 mm and is made of rigid stainless steel (SUS304). The mass of the weight 4 is approximately 0.8 g, and has a resonance frequency peak at 600 Hz to 650 Hz in the direction perpendicular to the installation surface of the weight 4. The height of the entire sound-insulating structures 8a and 9a is 10.5 mm, and the overall surface density of one section 5, including the membrane 2, the support wall 3, and the weight 4, is 2.97 kg / m 2 The surface density is a value calculated from the weight and area of ​​the sample.

[0060] As shown in Figure 13, the end face of the support wall 3 of the sound-insulating structures 8a and 9a opposite the side attached to the membrane 2 was placed on a 0.8 mm thick steel plate 10, and sound insulation was measured with the surface of the steel plate 10 opposite the side on which the sound-insulating structures 8a and 9a were placed as the incident sound side. Specifically, in accordance with the intensity method specified in JIS A1441-1, a test facility with a reverberation chamber as the sound source room and a semi-anechoic chamber as the sound receiving room was used to determine the sound transmission loss (transmission loss) [dB] versus the 1 / 3 octave band center frequency [Hz] using 1 / 3 octave band analysis. The relationship between the 1 / 3 octave band center frequency and the sound transmission loss was determined, and is shown in Figures 14(A) to 14(F) and 15(E). The greater the sound transmission loss, the higher the sound insulation. In the 1 / 3 octave band center frequencies [Hz] shown in FIGS. 14(A) to 15(E), 1 kHz corresponds to 1000 Hz, and the prefix "k" means 1000.

[0061] [Comparative Example 1] As Comparative Example 1, as shown in Figure 16, sound insulation was measured with nothing placed on a 0.8 mm thick iron plate 10, and the relationship between the 1 / 3 octave band center frequency and sound transmission loss is shown in Figure 14(A). This shows the state where no soundproof structure is provided. The surface density of this structure is 6.02 kg / m 2 is.

[0062] Comparative Example 2 As Comparative Example 2, a member having the same mass as the sound-insulating structural members 8a and 9a of Example 1 was placed on a 0.8 mm thick iron plate 10. The theoretical sound-insulating value calculated based on the mass law was obtained, and the relationship between the 1 / 3 octave band center frequency and the sound transmission loss is shown in Figure 14(A). The surface density of this structure was 8.99 kg / m 2 is.

[0063] Comparative Example 3 As Comparative Example 3, a sound insulating structure consisting only of the film 2 and supporting wall 3 shown in Fig. 17(A) was placed on a 0.8 mm thick iron plate 10 as shown in Fig. 17(B) to measure sound insulating properties, and the relationship between the 1 / 3 octave band center frequency and sound transmission loss is shown in Figs. 14(A) to 14(B). The film 2 and supporting wall 3 of this comparative example are the same as those of Example 1, but do not have the weight 4. The surface density of this structure is 2.43 kg / m 2 is.

[0064] [Example 2] The sound-insulating structural members 8a and 9a of Example 2 of the present invention have the same structure as the second embodiment shown in Fig. 11. The film member 2 and the supporting wall member 3 of this example are the same as the film member 2 and the supporting wall member 3 of Example 1. The weight member 7 is made of EPDM having a durometer A hardness of 65 according to JIS K6253-3, and is cylindrical with a diameter of 13 mm and a height (dimension in the direction perpendicular to the film member 2) of 5 mm. The mass of the weight member 7 is approximately 0.85 g, and the surface density of this structure is 3.04 kg / m 2 As shown in Fig. 18, the end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on an iron plate 10 with a thickness of 0.8 mm, and the sound insulation was measured, and the result is shown in Fig. 14(B).

[0065] [Example 3] The sound insulating structure members 8a and 9a of Example 3 of the present invention shown in Figures 19(A) and 19(B) have the same structure as Example 2, but have a weight portion 7 that is smaller than the weight portion 7 of Example 2. The film portion 2 and the support wall portion 3 of this example are the same as the film portion 2 and the support wall portion 3 of Example 1. The weight portion 7 is made of EPDM with a durometer A hardness of 65 according to JIS K6253-3, and is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film portion 2) of 5 mm. The mass of the weight portion 7 is approximately 0.15 g. The surface density of this structure is 2.54 kg / m 2 As shown in Fig. 19(B), the end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on an iron plate 10 with a thickness of 0.8 mm, and the sound insulation was measured, and the result is shown in Fig. 14(B).

[0066] [Example 4] Sound insulating structures 8a, 9a (not shown) of Example 4 of the present invention have the same structure as Example 1, but have support wall portions 3 that are softer than the support wall portions 3 of Example 1. The film portion 2 and weight portion 4 of this example are the same as the film portion 2 and weight portion 4 of Example 1. The support wall portions 3 of this example are made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at 23°C and at frequencies of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 or more and 0.50 or less at 23°C and at frequencies of 1 Hz to 1000 Hz. More specifically, the support wall portion 3 of this example is made of EPDM having a dynamic storage modulus (E') of 1.48 MPa and a loss tangent (tanδ) of 0.07 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 1.72 MPa and a loss tangent (tanδ) of 0.12 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 2.00 MPa and a loss tangent (tanδ) of 0.11 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 2.33 MPa and a loss tangent (tanδ) of 0.12 at 23°C and a frequency of 1000 Hz, a durometer A hardness of 30 according to JIS K6253-3, a plate thickness of 1.6 mm, and a height of 10 mm in the direction perpendicular to the membrane portion 2. However, only the outermost support wall portion 3 has a plate thickness of half that, 0.8 mm. The areal density of this configuration is 2.52 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 14(C).

[0067] Comparative Example 4 The sound-insulating structure (not shown) of Comparative Example 4 has substantially the same structure as that of Example 1, but has a support wall 3 that is harder and less flexible than the support wall 3 of Example 1. The film portion 2 and weight portion 4 of this Comparative Example are the same as the film portion 2 and weight portion 4 of Example 1. The support wall 3 of this comparative example is made of polylactic acid (PLA resin) having a dynamic storage modulus (E') of 2.03 GPa and a loss tangent (tan δ) of 0.0045 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 2.04 GPa and a loss tangent (tan δ) of 0.000060 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 2.05 GPa and a loss tangent (tan δ) of 0.045 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 2.07 GPa and a loss tangent (tan δ) of 0.0079 at 23°C and a frequency of 1000 Hz, and its shape and dimensions are the same as those of the support wall 3 of Example 1. The areal density of this configuration is 2.63 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 14(C).

[0068] [Example 5] The sound insulating structural members 8a, 9a (not shown) of Example 5 have the same structure as Example 1, but have a film portion 2 that is softer than the film portion 2 of Example 1. The supporting wall portion 3 and weight portion 4 of this example are the same as the supporting wall portion 3 and weight portion 4 of Example 1. The film portion 2 of this example is made of EPDM having a durometer A hardness of 30 according to JIS K6253-3, the same material as the supporting wall portion 3 of Example 4, and its shape and dimensions are the same as the film portion 2 of Example 1. The surface density of this structure is 2.83 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 14(D).

[0069] [Example 6] The sound insulating structure parts 8a and 9a of Example 6 shown in Figures 20(A) and 20(B) have the same structure as Example 1, but have sections 5 that are wider than the sections 5 of Example 1. The film parts 2 and weight parts 4 of this example are the same as the film parts 2 and weight parts 4 of Example 1. The support wall parts 3 of this example are the same as the support wall parts 3 of Example 1, but are arranged side by side at wider intervals than in Example 1. As a result, each section of this example is a square of 50 mm x 50 mm, and its area is 2500 mm. 2 The areal density of this configuration is 1.60 kg / m 2 There are nine compartments 5 in a 200 mm x 200 mm square area (evaluation surface) of the membrane 2. However, the drawing only shows a part of this area. As shown in Figure 20(B), the end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the membrane 2 was placed on a 0.8 mm thick iron plate 10, and the sound insulation was measured, as shown in Figure 14(E).

[0070] [Example 7] The sound insulating structures 8a and 9a (not shown) of Example 7 have the same structure as Example 1, but the weight 4 is cylindrical with a diameter of 13 mm and a height (dimension in the direction perpendicular to the film 2) of 9 mm. Of this weight 4, the spring 4a, which is the part attached to the film 2, has a height of 4 mm and is made of an elastic body having a dynamic storage modulus (E') of 0.01 MPa or more and 100 MPa or less at 23°C and at frequencies of 1 Hz to 1000 Hz, and a loss tangent (tanδ) of 0.01 MPa or more and 0.50 or less at 23°C and at frequencies of 1 Hz to 1000 Hz. More specifically, the spring portion 4a in this embodiment is made of polyurethane foam having a dynamic storage modulus (E') of 0.06 MPa and a loss tangent (tanδ) of 0.15 at 1 Hz at 23°C, a dynamic storage modulus (E') of 0.07 MPa and a loss tangent (tanδ) of 0.15 at 10 Hz at 23°C, a dynamic storage modulus (E') of 0.08 MPa and a loss tangent (tanδ) of 0.15 at 100 Hz at 23°C, and a dynamic storage modulus (E') of 0.10 MPa and a loss tangent (tanδ) of 0.15 at 1000 Hz at 23°C. The mass portion 4b, which is the portion of the weight portion 4 opposite the side attached to the membrane portion 2, is 5 mm high and made of EPDM having a durometer A hardness of 65 according to JIS K6253-3. The mass of the weight portion 4 is approximately 1.0 g.

[0071] The membrane part 2 and the support wall part 3 of this embodiment are the same as the membrane part 2 and the support wall part 3 of Example 1. The surface density of this structure is 3.08 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 14(F).

[0072] [Example 8] The sound-insulating structures 8a and 9a (not shown) of Example 8 have the same structure as the modified example of the first embodiment shown in FIG. 10 . The film 2 and support wall 3 of this example are the same as those of Example 1, but the weight 4 of this example consists of a small-diameter, cylindrical spring 4a and a large-diameter, cylindrical mass 4b. The spring 4a, which is the part of the weight 4 attached to the film 2, is cylindrical with a diameter of 6 mm and a height (dimension perpendicular to the film 2) of 3 mm and is made of the same material as the spring 4a of the weight 4 of Example 1 (silicone rubber with a durometer A hardness of 10 according to JIS K6253-3). The mass 4b, which is the part of the weight 4 opposite the part attached to the film 2, is cylindrical with a diameter of 13 mm and a height of 5 mm and is made of EPDM with a durometer A hardness of 65 according to JIS K6253-3. The mass of the weight 4 is approximately 1.0 g. The surface density of this structure is 3.13 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, and the results are shown in Figures 14(F) to 15(A).

[0073] [Example 9] The sound-insulating structural members 8a, 9a (not shown) of Example 9 have the same structure as the modified example of the first embodiment shown in Fig. 10. The film member 2 and weight member 4 of this example are the same as the film member 2 and weight member 4 of Example 8, but the support wall member 3 of this example is made of EPDM having a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height of 10 mm in the direction perpendicular to the film member 2. The surface density of this structure is 2.81 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structures 8a and 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, and the results are shown in Figures 15(A) to 15(C).

[0074] [Example 10] The sound-insulating structural members 8a and 9a (not shown) of Example 10 have the same structure as the modified example of the first embodiment shown in Fig. 10. The film member 2 and weight member 4 of this example are the same as the film member 2 and weight member 4 of Example 9, but the support wall member 3 of this example is made of EPDM having a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height of 14 mm in the direction perpendicular to the film member 2. The surface density of this structure is 3.16 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 15(B).

[0075] [Example 11] The sound-insulating structures 8a and 9a (not shown) of Example 11 have the same structure as the modified example of the first embodiment shown in Fig. 10. The film 2 and weight 4 of this example are the same as the film 2 and weight 4 of Example 9, but in this example, some of the multiple support wall portions have a height extending in a direction perpendicular to the film 2 that is higher than the other support wall portions. That is, the sound-insulating structures 8a and 9a of this example have support wall portions (some of the support wall portions) that are as high in height as the support wall portion 3 of Example 10, and support wall portions (other support wall portions) that are as low in height as the support wall portion 3 of Example 9. Specifically, the low-height support wall portion is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height of 10 mm in the direction perpendicular to the membrane portion 2, while the high-height support wall portion is made of EPDM with a durometer A hardness of 30 according to JIS K6253, a plate thickness of 1.6 mm, and a height of 15 mm in the direction perpendicular to the membrane portion 2. The high-height support wall portion is 1.5 times the height of the low-height support wall portion. In this embodiment, rows containing high-height support wall portions and rows containing only low-height support wall portions are alternately positioned. As a result, of the 49 square compartments 5 arranged in a 7x7 grid, 16 compartments 5 are surrounded by high-height support wall portions. The surface density of this configuration is 3.02 kg / m 2 The end face of the supporting wall portion 3d of the sound-insulating structure portions 8a and 9a opposite to the side attached to the film portion 2 was placed on an iron plate 10 having a thickness of 0.8 mm, and the sound insulation property was measured, and the result is shown in Figure 15(C).

[0076] [Example 12] The sound insulating structures 8a and 9a (not shown) of Example 12 have the same structure as the modified example of the first embodiment shown in Fig. 10. The weight 4 of this example is the same as the weight 4 of Example 8. The membrane portion 2 and supporting wall portion 3 of this embodiment are formed by integral molding of styrene-based thermoplastic elastomer (TPS) with a dynamic storage modulus (E') of 7.81 MPa and a loss tangent (tanδ) of 0.06 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 8.62 MPa and a loss tangent (tanδ) of 0.08 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 9.19 MPa and a loss tangent (tanδ) of 0.11 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 10.3 MPa and a loss tangent (tanδ) of 0.08 at 23°C and a frequency of 1000 Hz, a durometer A hardness of 50 according to JIS K6253, a membrane portion 2 thickness of 1.0 mm, a supporting wall portion 3 thickness of 1.2 mm, and a height perpendicular to the membrane portion 2 of 10 mm. The areal density of this configuration is 2.56 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 15(D).

[0077] [Example 13] The sound-insulating structures 8a and 9a (not shown) of Example 13 have the same structure as the modified example of the first embodiment shown in Fig. 10. The film 2 and support wall 3 of this example are the same as the film 2 and support wall 3 of Example 12. The weight 4 of this example is composed of a small-diameter cylindrical spring portion 4a and a large-diameter cylindrical mass portion 4b. The spring portion 4a, which is the part of the weight portion 4 that is attached to the membrane portion 2, is cylindrical with a diameter of 6 mm and a height (dimension perpendicular to the membrane portion 2) of 3 mm, and is made of TPS with a dynamic storage modulus (E') of 0.19 MPa and a loss tangent (tanδ) of 0.03 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.19 MPa and a loss tangent (tanδ) of 0.04 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 0.19 MPa and a loss tangent (tanδ) of 0.25 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 0.23 MPa and a loss tangent (tanδ) of 0.04 at 23°C and a frequency of 1000 Hz, and a durometer A hardness of 0 according to JIS K6253. The mass portion 4b, which is the portion of the weight portion 4 opposite to the side attached to the membrane portion 2, is cylindrical with a diameter of 11 mm and a height of 6 mm, and is made of EPDM having a durometer A hardness of 70 according to JIS K6253-3. The surface density of this structure is 2.50 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 15(D).

[0078] [Example 14] The sound-insulating structure members 8a and 9a (not shown) of Example 14 have the same structure as the modified example of the first embodiment shown in FIG. 10. The film member 2 and the support wall member 3 of this example are the same as the film member 2 and the support wall member 3 of Example 12. The weight member 4 of this example consists of a small-diameter cylindrical spring member 4a and a large-diameter cylindrical mass member 4b. The spring member 4a, which is the part of the weight member 4 that is attached to the film member 2, is cylindrical with a diameter of 6 mm and a height (dimension in the direction perpendicular to the film member 2) of 3 mm. The mass member 4b, which is the part of the weight member 4 opposite the side that is attached to the film member 2, is cylindrical with a diameter of 9 mm and a height of 6 mm. The spring portion 4a and mass portion 4b of the weight portion 4 in this embodiment are made of TPS having a dynamic storage modulus (E') of 0.21 MPa and a loss tangent (tanδ) of 0.04 at 23°C and a frequency of 1 Hz, a dynamic storage modulus (E') of 0.23 MPa and a loss tangent (tanδ) of 0.03 at 23°C and a frequency of 10 Hz, a dynamic storage modulus (E') of 0.29 MPa and a loss tangent (tanδ) of 0.05 at 23°C and a frequency of 100 Hz, and a dynamic storage modulus (E') of 0.25 MPa and a loss tangent (tanδ) of 0.17 at 23°C and a frequency of 1000 Hz, and a durometer A hardness of 5 according to JIS K6253. The areal density of this configuration is 2.50 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure 8a, 9a opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 15(D).

[0079] Comparative Example 5 As Comparative Example 5, similar to Comparative Example 3, a sound insulating structure consisting only of a film 2 and a supporting wall 3 was placed on a 0.8 mm thick iron plate 10 as shown in FIG. 17, and sound insulating properties were measured. The relationship between the 1 / 3 octave band center frequency and the sound transmission loss is shown in FIG. 15(D). The film 2 and supporting wall 3 of this Comparative Example are different from those of Example 1 and Comparative Example 3, but are the same as those of Example 12. Furthermore, the sound insulating structure of this Comparative Example does not have a weight 4. The surface density of this structure is 1.88 kg / m 2 is.

[0080] Comparative Example 6 The sound-insulating structure (not shown) of Comparative Example 6 has the same structure as that of Example 1, but includes a film 2 made of a resin material with a thinner film thickness than that of Example 1. The supporting wall 3 and weight 4 of this Comparative Example are the same as those of Example 1. The film 2 of this Comparative Example is made of low-density polyethylene (LDPE) with a film thickness of 0.05 mm. The surface density of this structure is 2.25 kg / m 2 The end face of the supporting wall 3 of the sound-insulating structure opposite to the side attached to the film 2 was placed on a 0.8 mm thick iron plate 10 to measure the sound insulation, which is shown in Figure 15(E).

[0081] [result] The results of comparing the above-mentioned Examples 1 to 14 of the present invention with Comparative Examples 1 to 6 will be explained. Referring to Fig. 14(A), it can be seen that the sound insulating effect is improved by the sound insulating structures 8a and 9a of the present invention. In particular, the sound insulating structures 8a and 9a of Example 1 provide a sound insulating effect significantly greater than the theoretical value based on the mass law (Comparative Example 2) in the frequency band higher than 630 Hz, demonstrating the great effect of the present invention. Furthermore, it can be seen that Example 1, which has the weight portion 4, has greater sound insulating properties than Comparative Example 3, particularly in the frequency band lower than 1.25 kHz.

[0082] Referring to FIG. 14(B), it can be seen that the sound-insulating structures 8a and 9a (Example 1) of the first embodiment of the present invention and the sound-insulating structures 8a and 9a (Examples 2 and 3) of the second embodiment of the present invention both provide good sound-insulating effects. When the mass 4 itself constitutes a spring-mass resonator, as in Example 1, particularly good sound-insulating properties are obtained near frequencies (e.g., 630 Hz to 1000 Hz) where the vibration of the membrane 2 is reduced by the resonance of the spring-mass resonator. On the other hand, when the spring-mass resonator is formed by the mass 7 and the membrane 2, as in Examples 2 and 3, the frequency band where sound-insulating properties are particularly good can be adjusted by adjusting the weight of the mass 7. For example, when the mass of the mass 7 is similar to that of the mass 4 of Example 1, the frequency band where sound-insulating properties are particularly good is around 1000 Hz. By reducing the weight of the mass 7, the frequency band where sound-insulating properties are particularly good can be shifted to a higher frequency.

[0083] 14(C), it can be seen that if the support wall 3 of the sound-insulating structure 8a, 9a is not made of a flexible material, the sound-insulating effect is low, but if the support wall 3 is made of a flexible material, a good sound-insulating effect can be obtained. This is thought to be because if the support wall 3 is made of a hard material rather than a flexible material, vibrations are easily transmitted to the membrane 2 via the support wall 3, whereas if the support wall 3 is made of a flexible material, vibrations are less likely to be transmitted to the membrane 2 via the support wall 3. Note that the frequency band in which sound-insulating effect is particularly good can be adjusted by changing the hardness of the support wall 3. For example, if the support wall 3 is made softer, the frequency band in which sound-insulating effect is particularly good can be shifted to a lower frequency side.

[0084] 14(D), it can be seen that if the film portion 2 of the sound-insulating structures 8a and 9a is too soft, the sound insulation performance will be slightly reduced. This is thought to be because if the film portion 2 is too soft, vibrations of a degree sufficient for the spring-mass resonator to function properly will not be transmitted to the spring-mass resonator.

[0085] Referring to FIG. 14(E), it can be seen that if each section 5 of the membrane section 2 defined by the support wall section 3 of the sound insulating structure sections 8a, 9a is too large, the sound insulating properties will be slightly reduced. This is thought to be because if each section 5 is too large, the spring mass resonator will not function sufficiently, and the vibration reduction effect will be reduced. Therefore, each section 5 should be made small to some extent (for example, 1000 mm 2 ) is preferred.

[0086] 14(F) shows that even if the materials and shapes of the weights 4 of the sound-insulating structures 8a and 9a are different, as long as the materials and shapes are within the preferred ranges, the sound-insulating function of the present invention will be exhibited. Therefore, it can be seen that the materials and shapes of the weights 4, etc. can be freely set within the preferred ranges.

[0087] 15(A) shows that a similar sound-insulating effect can be obtained even if the durometer A hardness according to JIS K6253-3 of the support wall portion 3 differs to some extent. Furthermore, FIG. 15(B) shows that a good sound-insulating effect can be obtained by configuring the support wall portion 3 so that it is tall in the direction perpendicular to the film portion 2. This is because, when the support wall portion 3 is tall, the thickness of the air layer located between the film portion 2 and the mounting surface (the iron plate 10 in each embodiment) on which the sound-insulating structures 8a and 9a are placed is large, which changes the frequency band of air resonance transmission, reducing the impact of sound-insulating interference in the target frequency band and increasing sound insulation, particularly in the low-frequency range (for example, around 500 Hz).

[0088] Referring to FIG. 15(C), it can be seen that a good sound insulation effect can be obtained even when only some of the support walls are increased in height in the direction perpendicular to the film 2, while the other support walls are decreased in height. Even when only some of the support walls are increased in height, the thickness of the air layer between the film 2 and the support surface (the iron plate 10 in each embodiment) on which the sound-insulating structures 8a, 9a are placed is increased, as in the case of a configuration in which all of the support walls are increased in height. As a result, sound insulation is particularly enhanced in the low-frequency range (e.g., around 500 Hz), as described above. Furthermore, by increasing the height of only some of the support walls, the thickness of the air layer is increased while suppressing an increase in the overall weight of the sound-insulating structures 8a, 9a. This also makes it easy to stably mount the sound-insulating structures 8a, 9a on support surfaces of various shapes, including curved surfaces. In other words, a lightweight sound-insulating structure 8a, 9a with good sound insulation in the low-frequency range can be provided. If there are too few high support wall portions, it becomes difficult to stably support the sound insulation structures 8a, 9a, and if there are too many, the weight of the entire sound insulation structures 8a, 9a increases. Therefore, it is preferable that the sections 5 surrounded by high support wall portions are 5% or more of the total sections 5 of the sound insulation structures 8a, 9a. Also, when looking at a cross section of each support wall portion parallel to the film portion 2, it is preferable that the total cross-sectional area of ​​the high support wall portions is 10% or more of the total cross-sectional area of ​​all the support wall portions of the sound insulation structures 8a, 9a. In Example 11, a 20mm x 20mm (area 400cm) section of the film portion 2, which has a planar shape of 25mm x 25mm square, is 2) there are 7 x 7 = 49 compartments 5, of which 16 compartments 5 are compartments 5 surrounded by high support walls, which is a preferable proportion of 32.6%.

[0089] In addition, even when the height of all of the support wall portions 3 is high as in Example 10, or when the height of only some of the support wall portions is high as in Example 11, it is preferable to keep the overall height of the sound-insulating structures 8a, 9a to 20 mm or less, as mentioned above, in order to prevent an increase in the overall weight of the sound-insulating structures 8a, 9a and to prevent installation restrictions.

[0090] Referring to FIG. 15(D), it can be seen that even if the membrane portion 2 and the support wall portion 3 are formed by integral molding of a thermoplastic material, the provision of the weight portion 4 provides good sound insulation. In a spring-mass resonator consisting of the spring portion 4a and the mass portion 4b of the weight portion 4, as in Example 13, it can be seen that if the spring portion 4a is softer, the resonant frequency shifts to the lower frequency side, and a large sound insulation effect can be obtained at the lower frequency side. In this way, by changing the configuration of the weight portion 4, it is possible to adjust the sound insulation frequency band. Furthermore, it can be seen that good sound insulation can be obtained even if the weight portion 4 is made of a single material, as in Example 14. Therefore, productivity can be improved by manufacturing the weight portion from a single material.

[0091] 15(E), it can be seen that if the film portion 2 is made of a thin resin material (film), sound insulation performance will decrease, so it is preferable that the film portion 2 have a certain thickness. Compared to the elastomer material such as EPDM in Example 1, the resin material such as LDPE in Comparative Example 6 is hard, so it is possible to make the film thickness thin, but unless the film thickness is greater than a certain level, the film portion 2 will be too soft and vibrations sufficient to allow the spring-mass resonator consisting of the spring portion 4a and mass portion 4b of the weight portion 4 to function properly will not be transmitted to the weight portion 4. Therefore, it is preferable that the film portion 2 have a certain thickness or more.

[0092] The soundproof structures 8 and 9 of the present invention have soundproof structural members 8a and 9a as exemplified in Examples 1 to 14 described above, and also have soundproof plate-like members 8b and 9b. Therefore, it can be said that the difference in sound insulation property between the soundproof structural members 8a and 9a in Examples 1 to 14 represents the difference in sound insulation property between the soundproof structures 8 and 9. Furthermore, as described above, the soundproof structural members 8a and 9a in Examples 1 to 14 have greater sound insulation property than the structures of Comparative Examples 1 to 6. In addition, when the soundproof structures 8 and 9 are provided with the soundproof plate-like members 8b and 9b, it is thought that even better sound insulation property can be achieved.

[0093] The present invention includes the following configurations and methods. [1] The device is disposed in at least one or both of a position separating a space for accommodating rear tires from a vehicle interior and a position separating a space for accommodating front tires from a vehicle interior, a sound-insulating structure including an elastic film portion, an elastic support wall portion standing on the film portion, and a weight portion standing on the film portion; the membrane portion is divided into a plurality of compartments by the support wall portion, and the weight portion is located inside each of the plurality of compartments or inside some of the plurality of compartments, In the compartments in which the weight portions are located, one weight portion is disposed in one compartment, a height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than a height of the weight portion extending in a direction perpendicular to the membrane portion; A soundproof structure, characterized in that each of the weight portions constitutes a spring-mass resonator having an elastic spring portion and a mass portion having a mass greater than that of the spring portion. [2] The soundproof structure described in [1], wherein the membrane portion, the support wall portion, and the spring portion are all made of a material that has rubber elasticity but no energy elasticity, a material that has energy elasticity but no rubber elasticity, or a material that has both rubber elasticity and energy elasticity. [3] The soundproof structure according to [1] or [2], 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. [4] A soundproof structure according to any one of [1] to [3], wherein the film 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 a frequency of 1 Hz to 1000 Hz. [5] A soundproof structure described in any one of [1] to [4], wherein the spring portion is located on the side of the weight portion attached to the membrane portion, and the mass portion is located on the side opposite to the side of the weight portion attached to the membrane portion. [6] The device is disposed in at least one or both of a position separating the space in which rear tires are accommodated from the passenger compartment of a motor vehicle and a position separating the space in which front tires are accommodated from the passenger compartment; a sound-insulating structure including an elastic film portion, an elastic support wall portion standing on the film portion, and a weight portion standing on the film portion; the membrane portion is divided into a plurality of compartments by the support wall portion, and the weight portion is located inside each of the plurality of compartments or inside some of the plurality of compartments, In the compartments in which the weight portions are located, one weight portion is disposed in one compartment, a height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than a height of the weight portion extending in a direction perpendicular to the membrane portion; A soundproof structure, characterized in that the film portion serves as a spring portion and the weight portion serves as a mass portion, thereby forming a spring-mass resonator. [7] The soundproof structure described in [6], wherein both the membrane portion and the supporting wall portion are made of either a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity. [8] The soundproof structure according to [6] or [7], wherein the film portion and the supporting wall portion each 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. [9] The soundproof structure according to any one of [6] to [8], wherein the film portion and the supporting wall portion each have a loss tangent of 0.01 or more and 0.50 or less at 23°C and a frequency of 1 Hz to 1000 Hz.

[10] A soundproof structure according to any one of [1] to [9], comprising the soundproof structure portion and a soundproof plate-shaped portion, wherein the soundproof plate-shaped portion is formed integrally with at least one of the membrane portion and the support plate portion, or the membrane portion and the support plate portion are joined to each other and positioned alongside the soundproof structure portion in a plane.

[11] A soundproof structure according to any one of [1] to

[10] , wherein the area of ​​the main surface of the soundproof structure occupied by the soundproof structure portion is 5% or more and 95% or less of the area of ​​the entire soundproof structure.

[12] A soundproof structure according to any one of [1] to

[11] , attached to an interior panel of an electric vehicle.

[13] A soundproofing structure for an automobile, in which the soundproofing structure described in any one of [1] to

[12] is attached to the dash panel and rear floor, respectively. [Explanation of symbols]

[0094] 1. Automobiles 2 Membrane part 3 Support wall section 3a 1st wall 3b 2nd wall part 4 Weight part 4a Spring part 4b Mass part 5 plots 7 Weight 8,9 Soundproofing structure 8a, 9a Sound insulation structure 8b, 9b Soundproof plate-shaped part 10 Iron Plate 11 Rear tire 12 Space for accommodating rear tires 13 Cabin 14 Front tire 15 Space for housing front tires 16 Panel (Dash Panel) 17 Panel (rear floor)

Claims

1. The tire is disposed in at least one or both of a position separating a space for accommodating rear tires from a vehicle interior and a position separating a space for accommodating front tires from a vehicle interior, Including a sound-insulating structure, the sound-insulating structure includes an elastic film portion, an elastic support wall portion standing on the film portion, and a weight portion standing on the film portion, the membrane portion is divided into a plurality of compartments by the support wall portion, and the weight portion is located inside each of the plurality of compartments or inside some of the plurality of compartments, In the compartments in which the weight portions are located, one weight portion is disposed in one compartment, a height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than a height of the weight portion extending in a direction perpendicular to the membrane portion; A soundproof structure, characterized in that each of the weight portions constitutes a spring-mass resonator having an elastic spring portion and a mass portion having a mass greater than that of the spring portion.

2. 2. The soundproof structure of claim 1, wherein the membrane portion, the support wall portion, and the spring portion are all made of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity.

3. 3. The soundproof structure according to claim 1, 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.

4. 4. The soundproof structure according to claim 3, wherein the film 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 a frequency of 1 Hz to 1000 Hz.

5. 3. The soundproof structure according to claim 1, wherein the spring portion is located on the side of the weight portion attached to the membrane portion, and the mass portion is located on the opposite side of the weight portion from the side attached to the membrane portion.

6. The tire is disposed in at least one or both of a position separating a space for accommodating rear tires from a vehicle interior and a position separating a space for accommodating front tires from a vehicle interior, Including a sound-insulating structure, the sound-insulating structure includes an elastic film portion, an elastic support wall portion standing on the film portion, and a weight portion standing on the film portion, the membrane portion is divided into a plurality of compartments by the support wall portion, and the weight portion is located inside each of the plurality of compartments or inside some of the plurality of compartments, In the compartments in which the weight portions are located, one weight portion is disposed in one compartment, a height of the support wall portion extending in a direction perpendicular to the membrane portion is greater than a height of the weight portion extending in a direction perpendicular to the membrane portion; A soundproof structure, characterized in that the film portion serves as a spring portion and the weight portion serves as a mass portion, thereby forming a spring-mass resonator.

7. 7. The soundproof structure according to claim 6, wherein the membrane portion and the support wall portion are made of a material that has rubber elasticity but not energy elasticity, a material that has energy elasticity but not rubber elasticity, or a material that has both rubber elasticity and energy elasticity.

8. 8. The soundproof structure according to claim 6, wherein the film portion and the supporting wall portion each 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.

9. 9. The soundproof structure according to claim 8, wherein the film portion and the support wall portion each have a loss tangent of 0.01 or more and 0.50 or less at 23° C. and a frequency range of 1 Hz to 1000 Hz.

10. 7. The soundproof structure according to claim 1, further comprising a soundproofing structure portion and a soundproofing plate-shaped portion, the soundproofing plate-shaped portion being integrally formed with at least one of the membrane portion and the support plate portion, or the soundproofing plate-shaped portion being joined to the membrane portion and the support plate portion, and being positioned alongside the soundproofing structure portion in a plane.

11. 11. The soundproof structure according to claim 10, wherein the area of ​​the main surface of the soundproof structure occupied by the soundproof structural portion is 5% to 95% of the area of ​​the entire soundproof structure.

12. 10. The soundproof structure according to claim 1 or 6, which is attached to an interior panel of an electric vehicle.

13. A soundproofing structure for an automobile, wherein the soundproofing structure according to claim 1 or 6 is attached to a dash panel and a rear floor, respectively.

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