Sheet-like soundproof structure, and automobile parts and duct-closing lid parts using the same

Abstract

To provide soundproofing means which offers superior soundproofing performance and reduced manufacturing cost.SOLUTION: The above challenge is cleared by bending a sheet-like soundproof structure for use, the soundproof structure comprising an elastic sheet, and a support member provided with multiple openings partitioned by a frame and configured to support the sheet and divide the sheet into planer divided sections. A surface of the support member on a side with the sheet has asperities, and the sheet is placed on the surface of the support member such that protrusions of the asperities penetrate in a thickness direction of the sheet.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a sheet-like soundproof structure that can be used, for example, in automobile parts, duct closing cover parts, etc. [Background technology]

[0002] A conventional soundproof structure is described in Patent Document 1. The soundproof structure described in Patent Document 1 includes an elastic sheet and a support portion that supports the sheet and divides the sheet. The support portion is a honeycomb structure in which a large number of cylindrical cells are arranged. This soundproof structure exhibits high soundproofing performance over a wide range of frequencies below 2000 Hz. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6879369 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, the conventional soundproof structure as described in Patent Document 1 has excellent soundproofing performance. On the other hand, the conventional soundproof structure has a problem that it is relatively expensive and difficult to reduce the manufacturing cost.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a soundproofing means that has excellent soundproofing performance and is capable of realizing reduction in manufacturing costs. [Means for solving the problem]

[0006] One aspect of the present invention provides a sheet-like soundproof structure. This sheet-like soundproof structure includes an elastic sheet, and a support member having a plurality of openings defined by crosspieces, supporting the sheet and defining the sheet into planar partitions. The sheet-like soundproof structure is characterized in that the surface of the support member on which the sheet is disposed has projections and recesses, the sheet is disposed on the surface of the support member such that the projections of the projections and recesses penetrate the sheet in the thickness direction, and the sheet is used in a curved state. Effect of the Invention

[0007] The sheet-like soundproof structure according to one embodiment of the present invention has the above-mentioned configuration, and thus has excellent soundproofing performance and can achieve reduced manufacturing costs. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a sheet-like soundproof structure according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a bottom view of the sheet-like soundproof structure according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. [Figure 4] FIG. 4 is an enlarged view of one opening 3C of the expanded metal 3 shown in FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which a sheet-like soundproof structure according to one embodiment of the present invention is used in a curved state. [Figure 7A] FIG. 7A is a graph showing the results of measuring the insertion loss in Comparative Example 1, Comparative Example 2, Example 1-1, and Example 1-2. [Figure 7B] FIG. 7B is a graph showing the results of measuring the insertion loss in Comparative Example 1, Comparative Example 2, Example 2-1, and Example 2-2. [Figure 8]FIG. 8 is a graph showing the results of measuring the soundproofing performance (insertion loss) of the sheet-like soundproofing structures produced in Reference Examples 1 and 2. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] One form of the present invention is a sheet-like soundproofing structure comprising an elastic sheet and a support member having a plurality of openings defined by crosspieces, supporting the sheet and defining the sheet into planar partitions, wherein the surface of the support member on which the sheet is disposed has projections and recesses, the sheet is disposed on the surface of the support member such that the projections of the projections penetrate in the thickness direction of the sheet, and the sheet-like soundproofing structure is used in a curved state.

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0011] Fig. 1 is a plan view of a sheet-like soundproof structure according to one embodiment of the present invention, Fig. 2 is a bottom view of the sheet-like soundproof structure according to one embodiment of the present invention, and Fig. 3 is a cross-sectional view taken along line III-III shown in Fig. 1.

[0012] The sheet-like soundproof structure 1 shown in Figures 1 to 3 comprises an elastic sheet 2 and an expanded metal 3 serving as a support member that supports the sheet 2 and divides the sheet 2 into planar partitions 2A. The expanded metal 3 serving as a support member has projections and recesses on both sides, and more specifically has projections 3B at the intersections of numerous diamond-shaped crosspieces 3A. As a result, the surface of the expanded metal 3 on which the sheet 2 is placed also has numerous projections 3B, and these projections 3B penetrate the sheet 2 in its thickness direction to form protrusions.

[0013] The sheet 2 is a flat membrane-like member made of rubber, for example, synthetic rubber. The expanded metal 3 functions as a support member that supports the sheet 2 and divides the sheet 2 into planar partitions 2A. Examples of such support members include expanded metal or expanded metal-like mesh members, or wire mesh or wire mesh-like mesh members. In the sheet-like soundproof structure 1 according to this embodiment, the support members are formed using such materials, and the partitions 2A can be easily formed in the sheet 2 through the openings 3C. As a result, the cross-sectional ratio of the openings in the support member can be increased, which contributes to reducing the overall mass. In addition, the above-mentioned sheets and support members can generally be mass-produced and are relatively inexpensive.

[0014] The expanded metal 3, which is the support member of this embodiment, has a bending rigidity larger than that of the sheet 2. As a result, resonance occurs on the surface of the support member due to acoustic waves, and surface resonance vibration also occurs in the sheet in contact with the support member. As a result, there is an advantage that the sound insulation performance is improved near the resonance frequency. However, in some cases, the bending rigidity of the support member may be smaller than that of the sheet. In addition, examples of materials constituting the support member having a bending rigidity larger than that of the sheet include metal materials such as stainless steel, iron, and aluminum. Although these materials are lightweight, by using them as the constituent materials of the support member according to this embodiment, sound insulation performance that greatly exceeds the mass law can be achieved. In addition, the material is not limited to metal, and may be, for example, plastic that can be manufactured by an expansion method involving heating.

[0015] Fig. 4 is an enlarged view of one opening 3C of the expanded metal 3 shown in Fig. 1. Fig. 5 is a cross-sectional view taken along line VV shown in Fig. 4. The expanded metal 3 and the like, which are the constituent materials of the support member in this embodiment, may have unavoidable unevenness on their surfaces due to their structure, as shown in Fig. 5. For this reason, if a support member such as the expanded metal 3 is directly fixed to a flat sheet 2, the unevenness may cause non-contact portions between the crosspiece 3A and the sheet 2, and the entire circumference of the partition portion 2A may not be covered by the crosspiece 3A, resulting in partial gaps that may impair soundproofing performance.

[0016] As described above, in the sheet-like soundproofing structure 1 of this embodiment, the convex portion 3B on the surface of the expanded metal 3 on which the sheet 2 is arranged is configured to penetrate the sheet 2 in its thickness direction.

[0017] According to the study by the inventors, it was found that the soundproofing performance is further improved by the projection 3B penetrating the sheet 2 in this way, compared with the case where the projection 3B does not even penetrate the sheet 2. The mechanism by which the sheet-like soundproofing structure according to this embodiment exhibits the above-mentioned action and effect is not completely clear, and the following mechanism is presumed, although the present invention is not bound by any theory. That is, according to the above-mentioned configuration, the entire circumference of the partition 2A is easily covered by the crosspiece 3A. As a result, it is possible to ensure that the surface rigidity of the sheet 2 in the partition 2A and the resonance frequency of the soundproofing structure 1 are within a preferable range, and it is considered that the soundproofing performance is improved. More specifically, when a uniformly distributed pressure is applied in the thickness direction of the sheet 2, the sheet-like soundproofing structure 1 can maintain the planar partition 2A as the surface rigidity of the sheet 2 is ensured. As a result, it is presumed that the position of maximum deflection of the planar partition 2A is present within the opening 3C of the expanded metal 3, and high soundproofing performance can be realized.

[0018] Furthermore, the sheet-like soundproof structure 1 according to this embodiment does not have any essential components other than the sheet and the support members. Therefore, the sheet-like soundproof structure 1 can obtain excellent soundproofing performance while using relatively inexpensive materials for the support members and reinforcing members, and can realize reduction in manufacturing costs.

[0019] As described above, the sheet-like soundproof structure 1 according to this embodiment has improved sound insulation performance in the vicinity of the resonance frequency by making the bending rigidity of the support member greater than the bending rigidity of the sheet 2.

[0020] The sheet-like soundproof structure according to this embodiment is characterized in that it is used in a curved state, not in a flat state as shown in Figs. 1 to 3. Fig. 6 is a cross-sectional view showing a state in which a sheet-like soundproof structure according to one embodiment of the present invention is used in a curved state. In the embodiment shown in Fig. 6, the sheet-like soundproof structure 1 is arranged so as to cover an opening 11 of a drafter (exhaust port) 10 for an automobile. The radius of curvature (length R shown in Fig. 6) indicating the degree of curvature of the sheet-like soundproof structure 1 is 135 mm. The elastic sheet 2 constituting the soundproof structure is arranged so as to be located on the opposite side of the center O of the radius of curvature R with respect to the expanded metal (support member).

[0021] According to the study by the inventors, it was found that the soundproofing performance is improved by using the sheet-like soundproofing structure having the above-mentioned configuration in a curved state compared to using it without curving (in a flat state). It was also found that, if the sheet-like soundproofing structure is used in a curved state, the expanded metal (supporting member) may be disposed on the opposite side of the center O of the radius of curvature R with respect to the elastic sheet 2, as opposed to FIG. 6. However, from the viewpoint of a higher improvement effect in soundproofing performance compared to using it without curving (in a flat state), it is more preferable that the elastic sheet 2 is disposed on the opposite side of the center O of the radius of curvature R with respect to the expanded metal (supporting member) as shown in FIG. 6. It should be noted that the mechanism by which the soundproofing performance is improved by using the sheet-like soundproofing structure in a curved state is not clear, but it is presumed that the surface rigidity of the sheet constituting each partition becomes a value suitable for the expression of soundproofing performance as a result of an appropriate stress being applied to the elastic sheet 2 by the curvature.

[0022] The radius of curvature R, which indicates the degree of curvature when the sheet-like soundproof structure is used in a curved state, is preferably R<220 mm, more preferably R≦200 mm, even more preferably R≦180 mm, still more preferably R≦160 mm, particularly preferably R≦140 mm, and most preferably R≦137 mm. There is no particular lower limit for the radius of curvature R, but it is usually R≧30 mm.

[0023] The sheet-like soundproof structure according to one embodiment of the present invention is not limited to the above embodiment in its configuration, and can be appropriately modified within the scope of the present invention. For example, in the sheet-like soundproof structure according to the above embodiment, the convex portion 3B present on the surface of the expanded metal 3 on the side where the sheet 2 is arranged penetrates the sheet 2 in the thickness direction to form a protrusion. However, the present invention is not limited to this configuration, and the convex portion 3B may penetrate into the sheet 2 without penetrating the sheet 2. Even with this configuration, the entire periphery of the partition portion 2A is easily covered by the crosspiece portion 3A as described above, and the planar partition portion 2A can be maintained with the surface rigidity of the sheet 2 ensured. As a result, high soundproof performance can be achieved. Here, if the sheet 2 is arranged on the surface of the expanded metal 3 (support member) so that the convex portion 3B penetrates the sheet 2 in the thickness direction, it is preferable from the viewpoint of covering the entire periphery of the partition portion 2A with the crosspiece portion 3A. On the other hand, when considering long-term use, there is a possibility that the sheet may deteriorate at the penetration portion, and therefore, from the standpoint of long-term durability, it is preferable that the sheet 2 is arranged on the surface of the expanded metal 3 (support member) so that the convex portion 3B penetrates the sheet 2 without penetrating it in the thickness direction.

[0024] The method for manufacturing the sheet-like soundproof structure according to this embodiment is not particularly limited, but an example is a method of pressing an elastic sheet and a support member in a laminated state in the lamination direction. That is, according to another embodiment of the present invention, a method for manufacturing a sheet-like soundproof structure is also provided, which includes pressing a laminate of an elastic sheet and a support member having a plurality of openings partitioned by a crosspiece and having an uneven surface on the sheet side in the lamination direction of the laminate, and arranging the sheet on the surface of the support member so that the convex parts of the unevenness penetrate the sheet in the thickness direction. According to this manufacturing method, a soundproof structure having excellent soundproof performance can be obtained at a low cost. In addition, when forming a laminate of an elastic sheet and a support member, by applying an adhesive between them, the entire outer periphery of the partition part can be more reliably adhered to the crosspiece of the support member. However, the use of an adhesive is not essential. In addition, by adjusting the thickness of the sheet and the pressing conditions, it is possible to control whether the convex parts penetrate the sheet or penetrate into the sheet without penetrating it. For example, when the pressing pressure in the lamination direction of the laminate is about 0.1 MPa, the convex parts do not penetrate the sheet. For this reason, the pressing pressure in the stacking direction of the laminate is preferably 0.3 MPa or more, more preferably 0.5 MPa or more, even more preferably 0.8 MPa or more, even more preferably 1.0 MPa or more, particularly preferably 1.5 MPa or more, and most preferably 2.0 MPa or more. There is no particular limit to the upper limit of the pressing pressure, but it is usually sufficient if it is 5.0 MPa or less. By pressing the laminate with such a pressing pressure, it is possible to flatten the expanded metal 3 etc. shown in FIG. 5 as a whole, while allowing the protrusions 3B to penetrate into the sheet 2.

[0025] The sheet-like soundproofing structure according to this embodiment can be applied to, for example, automobile parts or duct closing lid parts having a curved opening. That is, according to another embodiment of the present invention, an automobile part or duct closing lid part is provided that includes the sheet-like soundproofing structure according to one embodiment of the present invention. The automobile part or duct closing lid part can be an intrusion path for noise generated at the sound source. By applying the sheet-like soundproofing structure according to this embodiment to the automobile part or duct closing lid part, it is possible to more effectively block the intrusion of noise from such parts.

[0026] The following embodiments are also included within the scope of the present invention: a sheet-like soundproof structure as defined in any one of claims 1 to 3 having the features of claim 4; a sheet-like soundproof structure as defined in any one of claims 1 to 4 having the features of claim 5; a sheet-like soundproof structure as defined in any one of claims 1 to 5 having the features of claim 6; a sheet-like soundproof structure as defined in any one of claims 1 to 6 having the features of claim 7; a sheet-like soundproof structure as defined in any one of claims 1 to 7 having the features of claim 8; a sheet-like soundproof structure as defined in any one of claims 1 to 8 having the features of claim 9; an automobile part comprising a sheet-like soundproof structure as defined in any one of claims 1 to 9; and a duct closing lid part comprising a sheet-like soundproof structure as defined in any one of claims 1 to 9. EXAMPLES

[0027] The present invention will be described in more detail below with reference to examples, although the technical scope of the present invention is not limited to the following examples.

[0028] <Evaluation of soundproofing performance of sheet-type soundproofing structures> The soundproofing performance against sound waves of each frequency was measured for the sheet-like soundproofing structures produced in the manufacturing examples described later. Specifically, a speaker (sound source) was placed inside a soundproofing box made of an iron pot, and a 200 mm x 200 mm sample (soundproofing structure) was placed in the opening (170 mm x 170 mm square) of the soundproofing box so that their centers and orientations were aligned. In this case, in the comparative example, the sample (soundproofing structure) was placed in a flat state. On the other hand, in the example, the sample (soundproofing structure) was placed in a curved state. The gaps caused by the curve were filled with clay.

[0029] After that, sound was generated from a speaker (sound source) installed inside the soundproofing box, and the insertion loss (unit: dB) was measured compared to the control (when no sample (soundproofing structure) was placed), to evaluate the soundproofing performance. The larger the insertion loss value at a certain frequency, the better the soundproofing performance against sound waves of that frequency. The sound source generation conditions were as follows: Spectrum level: White noise (100~8192Hz) F max :8192Hz ·Δf (frequency resolution): 1Hz Average value: 300 arithmetic average (300 measurements were taken at slightly different times for each measurement, and the arithmetic average was used as the measured value) Overlap: 75%.

[0030] <Production example of sheet-shaped soundproof structure> As an elastic sheet, a sheet (thickness 150 μm) made of thermoplastic polyester elastomer (manufactured by Toray Celanese Co., Ltd., Hytrel (registered trademark)) 3046 was prepared. An adhesive-coated aluminum expand metal (support member) was laminated on one side of this sheet to obtain a laminate. Next, this laminate was pressed using a flat press. The pressing pressure was 2.0 MPa, the pressing machine's platen temperature was 150°C, and the pressing time was 2 minutes. The laminate (sheet-like soundproof structure) thus obtained was arranged as in the following comparative examples and examples to evaluate the soundproofing performance. It was confirmed that in the obtained sheet-like soundproof structure, the convex portion of the support member penetrated the sheet, and no gap existed between the outer periphery of the partition portion of the sheet and the crosspiece portion of the support member.

[0031] [Comparative Example 1] The sheet-like soundproof structure produced above was placed flat without being curved at the opening of a soundproof box to evaluate the soundproof performance. At this time, the soundproof structure was placed so that the support member was located on the soundproof box side with respect to the sheet.

[0032] [Comparative Example 2] The soundproofing performance was evaluated in the same manner as in Comparative Example 1 described above, except that the soundproofing structure was arranged so that the sheet was located on the soundproofing box side relative to the support member.

[0033] [Example 1-1] Except for the fact that the sheet-like soundproof structure was placed in a curved state toward the outside of the soundproof box, the soundproof performance was evaluated in the same manner as in the above-mentioned Comparative Example 1. The radius of curvature R, which indicates the degree of curvature, was set to R = 220 mm.

[0034] [Example 1-2] Except for the fact that the sheet-like soundproof structure was arranged in a curved state toward the outside of the soundproof box, the soundproof performance was evaluated in the same manner as in the above-mentioned Comparative Example 2. The radius of curvature R, which indicates the degree of curvature, was set to R = 220 mm.

[0035] [Example 2-1] Except for the fact that the sheet-like soundproof structure was placed in a curved state toward the outside of the soundproof box, the soundproof performance was evaluated in the same manner as in the above-mentioned Comparative Example 1. The radius of curvature R, which indicates the degree of curvature, was set to R = 137 mm.

[0036] [Example 2-2] Except for the fact that the sheet-like soundproof structure was placed in a curved state toward the outside of the soundproof box, the soundproof performance was evaluated in the same manner as in the above-mentioned Comparative Example 2. The radius of curvature R, which indicates the degree of curvature, was set to R = 137 mm.

[0037] [Soundproofing performance evaluation results (1)] The results for the above comparative example and example in the frequency range of 400 to 1200 Hz are shown in FIG. 7A and FIG. 7B.

[0038] Fig. 7A is a graph showing the results of measuring the insertion loss in Comparative Example 1 and Comparative Example 2, and Examples 1-1 and 1-2. Fig. 7A also shows a graph in which the insertion loss of Comparative Example 1 is subtracted from the insertion loss of Example 1-1 (the difference between Example 1-1 and Comparative Example 1) and a graph in which the insertion loss of Comparative Example 2 is subtracted from the insertion loss of Example 1-2 (the difference between Example 1-2 and Comparative Example 1).

[0039] As shown in Fig. 7A, in both Example 1-1 and Example 1-2, it was observed that the frequency ranges showing higher insertion loss than the corresponding comparative example existed in the road noise range of about 800 Hz and about 1000 Hz. This means that the sheet-like soundproofing structure of this example exhibits excellent soundproofing performance against sounds in these frequency bands. Moreover, this effect of improving the insertion loss was more pronounced in Example 1-1 (wherein the soundproofing structure is arranged so that the support member is located on the soundproofing box side relative to the sheet) than in Example 1-2 (wherein the soundproofing structure is arranged so that the sheet is located on the soundproofing box side relative to the support member).

[0040] Fig. 7B is a graph showing the results of measuring the insertion loss in Comparative Example 1 and Comparative Example 2, and Examples 2-1 and 2-2. Fig. 7B also shows a graph in which the insertion loss of Comparative Example 1 is subtracted from the insertion loss of Example 2-1 (the difference between Example 2-1 and Comparative Example 1) and a graph in which the insertion loss of Comparative Example 2 is subtracted from the insertion loss of Example 2-2 (the difference between Example 2-2 and Comparative Example 1).

[0041] As shown in FIG. 7B, in both Example 2-1 and Example 2-2, it was observed that the frequency ranges showing higher insertion loss than the corresponding comparative example existed in the road noise range of about 800 Hz and about 1000 Hz. This means that the sheet-like soundproofing structure of this example exhibits excellent soundproofing performance against sounds in these frequency bands. In addition, this effect of improving the insertion loss was more pronounced in Example 2-1 (wherein the soundproofing structure was arranged so that the support member was located on the soundproofing box side relative to the sheet) than in Example 2-2 (wherein the soundproofing structure was arranged so that the sheet was located on the soundproofing box side relative to the support member). Furthermore, in Examples 2-1 and 2-2, the sheet-like soundproofing structures were curved more (the radius of curvature R was made smaller) than in Examples 1-1 and 1-2. As a result, the effect of increasing the insertion loss shown as the difference in the graph was more pronounced.

[0042] [Reference example 1] As an elastic sheet (thermal adhesive film), a sheet (thickness 300 μm) made of ethylene-methacrylic acid-isobutylene acrylate terpolymer (manufactured by Mitsui Dow Polychemicals, Nucrell (registered trademark) N035C) was prepared. An adhesive-coated aluminum expand metal (support member) was laminated on one side of this sheet to obtain a laminate. Next, this laminate was pressed using a flat press. The pressing pressure was 10 MPa, the pressing plate temperature was 90° C., and the pressing time was 4 minutes. The laminate thus obtained was used as the sheet-like soundproof structure of this reference example. It was confirmed that in the sheet-like soundproof structure of this reference example, the convex portion of the support member penetrates the sheet, and no gap exists between the outer periphery of the partition portion of the sheet and the crosspiece portion of the support member.

[0043] [Reference example 2] A laminate was produced using the same method as in Reference Example 1 described above, except that the pressing pressure when pressing the laminate was changed to 1.0 MPa, the pressing time was changed to 2 minutes, and the platen temperature of the press machine was changed to 55°C on the heat-sealing film side and 90°C on the support member side, to produce a sheet-like soundproof structure of this Reference Example. In the sheet-like soundproof structure of this Reference Example, it was confirmed that the convex parts of the support member penetrate into the sheet without penetrating it, and that there was no gap between the outer periphery of the partition part of the sheet and the battens of the support member. In addition, the fact that the convex parts of the support member penetrate into the sheet without penetrating it was also confirmed by connecting terminals to the contact parts between the expanded metal battens of the sample and the expanded metal convex parts of the film using a digital multimeter (manufactured by Yokogawa Instruments Works, Ltd., model number: 7541) and finding that the electrical resistance value was over-range (overload (OL; no current flowing).

[0044] [Soundproofing performance evaluation results (2)] The soundproofing performance (insertion loss) of the sheet-like soundproofing structures produced in Reference Examples 1 and 2 was measured by the method described above. The results in the frequency range of 400 to 8000 Hz are shown in Fig. 8. The solid line graph in Fig. 8 shows the measurement results. The dashed line graph in Fig. 8 shows the insertion loss estimated from the areal density values ​​of the sheet-like soundproofing structures produced in each Reference Example, assuming that the soundproofing performance is exhibited according to only the mass law.

[0045] As shown in FIG. 8, in Reference Example 1 in which the convex portion of the support member penetrates the sheet, and Reference Example 2 in which the convex portion penetrates the sheet without penetrating the sheet, almost the same insertion loss profile was observed, and in each example, insertion loss peaks exceeding the dashed line graph were observed in the frequency ranges of about 400 to 800 Hz, 1200 to 1800 Hz, and 2000 to 2400 Hz. Among these, the insertion loss peaks in the road noise range of about 400 Hz to about 800 Hz in particular mean that the sheet-like soundproofing structures of Reference Examples 1 and 2 exhibit excellent soundproofing performance against sounds in these frequency bands. Therefore, it is presumed that not only when the convex portion of the support member penetrates the sheet as in each of the above-mentioned examples, but also when the convex portion of the support member penetrates the sheet without penetrating the sheet, it will exhibit better soundproofing performance by being curved and used.

[0046] As described above, the sheet-like soundproof structure according to the present invention has excellent soundproofing performance and can reduce manufacturing costs. [Explanation of symbols]

[0047] 1. Sheet-like soundproof structure, 2. Elastic sheet; 2A compartment, 3 Expanded metal (support member), 3A cross section, 3B Convex part, 3C opening, 10 Drafter, 11 aperture, R Radius of curvature.

Claims

1. An elastic sheet; a support member having a plurality of openings defined by crosspieces, supporting the sheet and defining the sheet into planar partitions; Equipped with the surface of the support member on which the sheet is disposed has projections and recesses, and the sheet is disposed on the surface of the support member such that the projections of the projections and recesses penetrate the sheet in a thickness direction; A sheet-like soundproofing structure that is used in a curved state.

2. 2. The sheet-like soundproof structure according to claim 1, which is used while being curved so that the radius of curvature R is less than 220 mm.

3. 3. The sheet-like soundproof structure according to claim 2, which is used while being curved so that the radius of curvature R is 137 mm or less.

4. 4. The sheet-like soundproof structure according to claim 1, wherein the sheet is disposed on the opposite side of the center of the radius of curvature with respect to the support member.

5. 4. The sheet-like soundproofing structure according to claim 1, wherein the sheet is disposed on the surface of the support member such that the protrusions penetrate the sheet in a thickness direction.

6. 4. The sheet-like soundproof structure according to claim 1, wherein the sheet is disposed on the surface of the support member so that the protrusions do not penetrate the sheet in a thickness direction.

7. 4. The sheet-like soundproofing structure according to claim 1, wherein the support member is an expanded metal or an expanded metal-like mesh member, or a wire mesh or a wire mesh-like mesh member.

8. 4. The sheet-like soundproof structure according to claim 1, wherein the supporting member is made of a material selected from the group consisting of stainless steel, iron and aluminum.

9. 4. The sheet-like soundproof structure according to claim 1, wherein the bending rigidity of the support member is greater than the bending rigidity of the sheet.

10. An automobile part comprising the sheet-like soundproof structure according to claim 1 or 3.

11. A duct closing cover part comprising the sheet-like soundproof structure according to claim 1 or 3.

Images