Acoustic material

Abstract

To provide an acoustic material advantageous in securing of both flexural rigidity and acoustic performance.SOLUTION: A plurality of slender plate-shaped reinforcing plates 14 formed of a material with higher rigidity than an acoustic material body 12 formed of an acoustic material having predetermined acoustic performance are embedded in the acoustic material body 12. The plurality of reinforcing plates 14 position a direction of their height H1 of the reinforcing plates 14 along a direction of thickness T2 of the acoustic material body 12. Both ends of the respective reinforcing plates 14 in the direction of the height H1 are arranged at positions away from both surfaces of the acoustic material body 12 in the direction of the thickness T2, and the plurality of reinforcing plates 14 are arranged intersecting with each other, so that a closed cross section structure surrounded by the plurality of reinforcing plates 14 is formed when viewed from the direction of the thickness T2 of the acoustic material body 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to acoustic materials. [Background technology]

[0002] Acoustic materials have been provided that can be attached to structures such as the hull of a ship to reflect, absorb, and transmit sound waves (see Patent Document 1). One such acoustic material is a rectangular plate made of a viscoelastic material of uniform thickness, which is attached by overlapping it on the outer surface of the steel plate that constitutes the structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-227702 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in recent years, there has been a demand for thinner steel plates constituting structures in order to reduce the weight of the structures. However, thinner steel plates are disadvantageous in terms of ensuring the strength of the structures. Therefore, it is possible to incorporate the acoustic material itself as a structural member (reinforcing member) into the structural design of the structure by sandwiching a reinforcing layer made of FRP, synthetic resin, or metal material inside the acoustic material to give the acoustic material bending rigidity. In other words, by using the acoustic material itself as a structural component that constitutes a structure such as a hull, the strength of the entire structure consisting of the structure and the acoustic material can be ensured even if the steel plates of the structure are made thin. However, in this case, the reinforcing layer, which is a different material with different material and physical properties from the viscoelastic material that makes up the acoustic material, receives sound waves on its surface, so the acoustic performance of the acoustic material (sound insulation, sound absorption, transparency) is likely to be affected by the reinforcing layer, which may be disadvantageous in ensuring the desired acoustic performance of the acoustic material. The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an acoustic material that is advantageous in ensuring both bending rigidity and acoustic performance. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention comprises a plate-shaped acoustic material body having a thickness formed from an acoustic material having a predetermined acoustic performance, and a plurality of elongated plate-shaped reinforcing plates formed from a material having higher rigidity than the acoustic material body, having a thickness, a height that is greater than the thickness, and a length that is greater than the height, and embedded in the acoustic material body, wherein the plurality of reinforcing plates are arranged so that the height direction of the reinforcing plate is aligned with the thickness direction of the acoustic material body, and both ends of the height direction of the reinforcing body are positioned at locations away from both sides in the thickness direction of the acoustic material body, and the plurality of reinforcing plates are arranged so that they intersect with each other, thereby forming a closed cross-sectional structure surrounded by the plurality of reinforcing plates when viewed from the thickness direction of the acoustic material body. In addition, one embodiment of the present invention comprises a plate-shaped acoustic material body having a thickness formed from an acoustic material having a predetermined acoustic performance, and a plate-shaped reinforcing plate formed from a material with higher rigidity than the acoustic material body, and having a thickness, a height that is greater than the thickness, and a length that is greater than the height, wherein the height direction of the reinforcing plate is oriented along the thickness direction of the acoustic material body and is arranged to cover the entire outer peripheral surface of the acoustic material body, and a closed cross-sectional structure surrounded by the reinforcing plate is formed. Effect of the Invention

[0006] According to one embodiment of the present invention, the multiple reinforcing plates are advantageous in securing the bending rigidity of the acoustic material, and the closed cross-sectional structure surrounded by multiple reinforcing plates has a large rigidity, which is advantageous in securing the bending rigidity in all directions when the acoustic material is subjected to torsional stress. Therefore, it is advantageous in suppressing the deformation amount and displacement amount (distortion) of the acoustic material when pressure is applied to the acoustic material. Furthermore, when viewed from the direction from which the sound waves arrive, the area of ​​the multiple reinforcing plates occupies an extremely small proportion of the area of ​​the main acoustic material, so even though reinforcing plates made of a material different from the main acoustic material are provided, the impact on the acoustic performance of the acoustic material is minimized. This is therefore advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a plan view of the acoustic material of the first embodiment. [Diagram 2] 1 is an explanatory diagram of a reinforcing plate embedded in an acoustic material body. [Diagram 3] 1A is a perspective view showing a state before the intersection portion is assembled, and FIG. 1B is a perspective view showing a state after the intersection portion is assembled. [Figure 4] FIG. 11 is a plan view of an acoustic material according to a second embodiment. [Diagram 5] FIG. 13 is a plan view of an acoustic material according to a third embodiment. [Figure 6] FIG. 13 is a plan view of an acoustic material according to a fourth embodiment. [Figure 7] FIG. 13 is a plan view of an acoustic material according to a fifth embodiment. [Figure 8] FIG. 13 is a plan view of an acoustic material according to a sixth embodiment. [Figure 9] FIG. 13 is a plan view of an acoustic material according to the seventh embodiment. [Figure 10] FIG. 13 is a plan view of an acoustic material according to the eighth embodiment. [Figure 11] FIG. 13 is a plan view of an acoustic material according to the 9th embodiment. [Figure 12] FIG. 17 is a plan view of an acoustic material according to the tenth embodiment. [Figure 13] FIG. 17 is a plan view of an acoustic material according to the 11th embodiment. [Figure 14] FIG. 11 is an oblique view of an acoustic material according to an eleventh embodiment. [Figure 15] FIG. 12 is a plan view of an acoustic material according to a twelfth embodiment. [Figure 16] FIG. 13 is a plan view of an acoustic material according to the thirteenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) Next, an acoustic material 10A according to a first embodiment will be described with reference to FIGS. The acoustic material 10A is attached by overlapping it on the outer surface (attachment surface) of a steel plate that constitutes a structure (not shown) such as the hull of a ship, thereby reflecting, absorbing, and transmitting sound waves. The acoustic material 10A includes an acoustic material body 12 and a reinforcing plate 14. The acoustic material body 12 is formed from an acoustic material having predetermined acoustic performance (sound insulation, sound absorption, and transparency), and in this embodiment, a viscoelastic body is used as the acoustic material. As the viscoelastic body, various conventionally known viscoelastic bodies such as rubber and synthetic resins such as urethane can be used. As shown in Figs. 1 and 2, the acoustic material body 12 is formed in the shape of a rectangular plate having a uniform thickness T2, a uniform width W2 that is greater than the thickness T2, and a uniform length L2. In this embodiment, it is formed into a square plate with the width W2 and length L2 being equal, and mounting holes 16 are formed through the four corners 1202 of the acoustic material main body 12 for mounting the acoustic material 10A to a structure such as a ship's hull. The acoustic material 10A is attached to the structure by bolts inserted through the mounting holes 16. In addition, the locations where the mounting holes 16 are provided are not limited to the corners of the rectangle that defines the outline of the acoustic material main body 12, but multiple holes may be provided at intervals on each side of the rectangle excluding the corners, or multiple holes may be provided in the center of the rectangle or around the center at locations that do not interfere with the intersection 1402 of the reinforcing plate 14 described later, and the locations and number of mounting holes 16 can be determined arbitrarily depending on the shape and size of the acoustic material 10A.

[0009] The reinforcing plate 14 is formed from a material having higher rigidity than the acoustic material body 12 and is embedded in the acoustic material body 12. Four reinforcing plates 14 are provided, each having the same shape and extending linearly. The reinforcing plate 14 can be made of various conventionally known materials such as FRP (fiber reinforced plastic), synthetic resin, and metal. Using a material such as FRP, which has acoustic performance similar to that of the acoustic material (viscoelastic material), in other words, a material with an acoustic impedance similar to that of the acoustic material, as the reinforcing plate 14 is advantageous in ensuring the acoustic performance of the acoustic material 10A, and in this embodiment, FRP is used as the reinforcing plate 14. As shown in FIG. 2, the four reinforcing plates 14 are of the same shape, and are elongated plates having a uniform thickness T1, a uniform height H1 that is greater than the thickness T1, and a uniform length L1 that is greater than the height H1. The height H1 of the reinforcing plate 14 is formed to be smaller than the thickness T2 of the acoustic material body 12, and the length L1 of the reinforcing plate 14 is formed to be slightly smaller than one side of the square 1210 that defines the outline of the acoustic material body 12. The reinforcing plate 14 is arranged with the height H1 direction of the reinforcing plate 14 aligned along the thickness T2 direction of the acoustic material main body 12, and both ends of the reinforcing material 14 in the height H1 direction are located away from both sides of the acoustic material main body 12 in the thickness T2 direction. In this embodiment, the thickness T1 of the reinforcing plate 14 is approximately 1 mm to 20 mm, and both ends of the reinforcing plate 14 in the height H1 direction are located approximately 1 mm away from both sides of the acoustic material main body 12 in the thickness T2 direction, and both ends of the reinforcing plate 14 in the length L1 direction are located away from the end faces of the acoustic material main body 12 in the width W2 direction and the end faces of the acoustic material main body 12 in the length L2 direction. Therefore, the portions of the acoustic material main body 12 located on both sides of the reinforcing plate 14 are connected over the entire length of the reinforcing plate 14 in the direction of length L1 at both ends of the reinforcing plate 14 in the direction of height H1, and are also connected at both ends of the reinforcing plate 14 in the direction of length L1.

[0010] The acoustic material main body 12 is formed in a square shape, and each reinforcing plate 14 is arranged parallel to each side in the vicinity of the four sides of the square 1210, and both ends of each reinforcing plate 14 form intersections 1402 that intersect with adjacent reinforcing plates 14 at right angles, each intersection 1402 is located in the vicinity of a corner 1202 of the square 1210, and mounting holes 16 are located in the vicinity of each intersection 1402. In a structure in which adjacent reinforcing plates 14 intersect at right angles, as shown in Figures 3(A) and (B), two reinforcing plates 14 may be assembled in a cross shape via cutouts 1410 provided at the longitudinal ends thereof, and the cross shape may be maintained by an adhesive, or may be formed using a mold. When molding is performed using a mold, the four reinforcing plates 14 are molded as a single piece, and the reinforcing plate 14 becomes one component. In the embodiment described later, a plurality of reinforcing plates 14 may be integrally molded using a die, and the reinforcing plate 14 may be a single component. Therefore, when viewed in the thickness T2 direction of the acoustic material body 12, the four reinforcing plates 14 form a square frame-shaped closed cross-sectional structure similar in shape to the square 1210 that defines the contour of the acoustic material body 12. The center of this closed cross-sectional structure is located at a point that coincides with the center of the acoustic material main body 12, and in this embodiment, it is located at a point where the center of the closed cross-sectional structure and the center of the acoustic material main body 12 coincide, and the four reinforcing plates 14 are located on the outer periphery of the acoustic material main body 12. The reinforcing plate 14 is made of FRP, and the reinforcing fibers constituting the reinforcing plate 14 are embedded inside the reinforcing plate 14 so as to be parallel to both sides of the reinforcing plate 14 in the thickness T1 direction. Therefore, in this embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical with respect to a center line that passes through the center of the acoustic material body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetric with respect to the intersection of the two diagonals of the acoustic material body 12.

[0011] Next, the effects will be described. According to the acoustic material 10A of this embodiment, a plurality of elongated, plate-like reinforcing plates 14 made of a material having higher rigidity than the acoustic material main body 12 are embedded in an acoustic material main body 12 formed of an acoustic material having predetermined acoustic performance, and the plurality of reinforcing plates 14 are arranged so that the height H1 direction of the reinforcing plates 14 is aligned with the thickness T2 direction of the acoustic material main body 12 and both ends of the height H1 direction of the reinforcing plates 14 are positioned away from both sides of the thickness T2 direction of the acoustic material main body 12, and the plurality of reinforcing plates 14 are arranged so as to intersect with each other, thereby forming a closed cross-sectional structure surrounded by the plurality of reinforcing plates 14 when viewed from the thickness T2 direction of the acoustic material main body 12. Therefore, not only is it advantageous to ensure the bending rigidity of acoustic material 10A by using multiple reinforcing plates 14, but the closed cross-sectional structure made up of multiple reinforcing plates 14 has a large rigidity in itself, which is advantageous for ensuring bending rigidity in all directions when torsional stress occurs in acoustic material 10A. Therefore, it is advantageous for suppressing the amount of deformation and displacement (distortion) of acoustic material 10A when pressure is applied to acoustic material 10A. Furthermore, when viewed from the direction from which the sound waves arrive, the area of ​​the multiple reinforcing plates 14 occupies a very small proportion of the area of ​​the acoustic material main body 12, so even though the reinforcing plates 14 are made of a material different from that of the acoustic material main body 12, the impact on the acoustic performance of the acoustic material 10A is minimal. This is therefore advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material 10A. In addition, since both ends of the reinforcing material 14 in the height H1 direction are located away from both sides of the acoustic material main body 12 in the thickness T2 direction, the acoustic material main body 12 is connected at both ends in the height H1 direction of the reinforcing plate 14 at the reinforcing plate 14, and the acoustic material main body 12 is not divided by the reinforcing plate 14, which is advantageous in ensuring the durability of the acoustic material 10A. Therefore, by using the acoustic material 10A itself as a structural component that constitutes a structure such as the hull, it is advantageous for ensuring the strength of the entire structure consisting of the structure and the acoustic material 10A even if the steel plates of the structure are made thin, which is advantageous for achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10A.

[0012] Furthermore, in this embodiment, the center of the closed cross-sectional structure is located at a position that coincides with the center of the contour of the acoustic material body 12, which is advantageous in ensuring that the bending rigidity of the entire acoustic material 10A is approximately uniform.

[0013] In addition, in this embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape symmetrical with respect to a center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12, which is advantageous in ensuring that the bending rigidity of the entire acoustic material 10A is approximately uniform.

[0014] In addition, in this embodiment, the multiple reinforcing plates 14 are arranged in a point-symmetric shape centered on the intersection of the two diagonals of the acoustic material main body 12, which is advantageous in ensuring that the bending rigidity of the entire acoustic material 10A is approximately uniform.

[0015] In addition, in this embodiment, mounting holes 16 for the acoustic material are formed in the four corners of the acoustic material main body 12 in the thickness direction of the acoustic material main body 12, and four reinforcing plates 14 are arranged parallel to the four sides of the rectangle that defines the outline of the acoustic material main body 12, and the intersection 1402 where adjacent reinforcing plates 14 intersect is located in the vicinity of the mounting holes 16, so that the length L1 of each reinforcing plate 14 can be made large, which is more advantageous in terms of ensuring the bending rigidity of the acoustic material 10A, and the rigidity of the portion of the acoustic material main body 12 in the vicinity of the mounting holes 16 is increased by the reinforcing plates 14, which is advantageous in terms of ensuring the mounting strength of the acoustic material 10A.

[0016] Although a metal material may be used as the reinforcing plate 14, if the reinforcing plate 14 is formed from a material whose acoustic performance is similar to that of the acoustic material, as in this embodiment, the effect of the reinforcing plate 14 on the acoustic performance can be suppressed, which is advantageous in ensuring the acoustic performance of the acoustic material 10A. Furthermore, when a viscoelastic material is used as the acoustic material and the reinforcing plate 14 is formed of FRP, as in this embodiment, the acoustic performance of the acoustic material and that of FRP are closer, which is more advantageous in suppressing the effect of the reinforcing plate 14 on the acoustic performance and ensuring the acoustic performance of the acoustic material 10A.

[0017] (Second embodiment) Next, a second embodiment will be described with reference to FIG. In the following embodiment, the same parts and members as those in the first embodiment are denoted by the same reference numerals, and the following description will focus on the differences from the first embodiment. Moreover, the mounting holes 16 are omitted from illustration in FIGS. In the acoustic material 10B of the following embodiment, the length L1 of the reinforcing plates 14, the number of plates, and the arrangement structure are different from those of the first embodiment. In the embodiments described below, including this embodiment, the thickness T1, height H1, material, etc. of the reinforcing plate 14 are the same as those in the first embodiment. In the second embodiment shown in Figure 4, four reinforcing plates 14 of the same length are used, and the length L1 of each reinforcing plate 14 is shorter than one side of the square 1210 that defines the outline of the acoustic material main body 12, and is formed with a dimension greater than 1 / 2 of one side of the square 1210. Two of the four reinforcing plates 14 are arranged parallel to the diagonal line connecting two opposing corners 1202 of the four corners 1202 of the square 1210 that forms the outline of the acoustic material body 12, and the remaining two reinforcing plates 14 are arranged parallel to the diagonal line connecting the remaining two opposing corners 1202 of the four corners 1202 of the square 1210 that forms the outline of the acoustic material body 12, and the four intersections 1402 where adjacent reinforcing plates 14 intersect at right angles are located on imaginary lines connecting the centers of two opposing sides of the square 1210.

[0018] Therefore, when viewed from the thickness T2 direction of the acoustic material main body 12, the four reinforcing plates 14 form a square frame-shaped closed cross-sectional structure similar in shape to the square 1210 that forms the outline of the acoustic material main body 12, and the four sides of this square that forms the closed cross-sectional structure are inclined at 45 degrees with respect to the four sides of the square 1210 that forms the outline of the acoustic material main body 12. The center of this closed cross-sectional structure is located at a position that coincides with the center of the acoustic material body 12, and in this embodiment, it is located at a position where the center of the closed cross-sectional structure and the center of the acoustic material body 12 coincide with each other. Therefore, in the second embodiment, the multiple reinforcing plates 14 are also arranged so as to have a shape that is symmetrical with respect to a center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetrical with respect to the intersection of two center lines connecting the centers of two opposing sides of the acoustic material main body 12. The acoustic material 10B of the second embodiment as described above also provides the same effects as the first embodiment.

[0019] (Third embodiment) Next, a third embodiment will be described with reference to FIG. In the third embodiment of acoustic material 10C shown in Figure 5, four reinforcing plates 14A-14D of the same length are used, and the length L1 of each reinforcing plate 14 is formed to be equal to one side of the square 1210 that defines the outline of the acoustic material main body 12. The first and second reinforcing plates 14A, 14B are disposed in the vicinity of two opposing sides of a square 1210 that defines the outline of the acoustic material body 12, and parallel to those two sides. Moreover, the third reinforcing plate 14C is disposed in the vicinity of one of the two sides of the remaining square 1210 and parallel to that side. Moreover, the fourth reinforcing plate 14D is disposed so as to pass through the center of the square 1210 in parallel with the third reinforcing plate 14C. Therefore, two intersections 1402 where adjacent reinforcing plates 14 intersect at right angles are provided near each of two opposing sides of the square 1210. Furthermore, mounting holes (not shown) are located near two intersections 1402 located near the two corners 1202 of the square 1210, and the remaining two intersections 1402 are located in the center of the length of two opposing sides of the square 1210. Therefore, when viewed from the thickness T2 direction of the acoustic material main body 12, the four reinforcing plates 14 form a rectangular frame-shaped closed cross-sectional structure having a short side shorter than one side of the square 1210 that forms the outline of the acoustic material main body 12 and a long side shorter than one side of the square 1210, and the center of this closed cross-sectional structure is located at a point displaced from the center of the square 1210 that forms the outline of the acoustic material main body 12.

[0020] Therefore, in the third embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape symmetrical with respect to a center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12. According to the acoustic material 10C of the third embodiment, the bending rigidity of the acoustic material 10C at the locations where the third reinforcing plate 14C and the fourth reinforcing plate 14D are arranged is set higher than that of other locations of the acoustic material 10C. Therefore, when acoustic material 10C is attached to a structure, if the pressure acting on the lower half of square 1210 defining the outline of acoustic material 10C is higher than the pressure acting on other parts of acoustic material 10C, attaching acoustic material 10C to the structure so that third reinforcing plate 14C and fourth reinforcing plate 14D are positioned at the parts where that pressure is applied will be advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10C, and will be advantageous in achieving both a lightweight structure and ensuring the acoustic performance of acoustic material 10C.

[0021] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. In the fourth embodiment of acoustic material 10D shown in Figure 6, six reinforcing plates 14 of the same length are used, and the length L1 of each reinforcing plate 14 is formed to be equal to one side of the square 1210 that defines the outline of the acoustic material main body 12. The four reinforcing plates 14 are arranged parallel to the four sides of the square 1210 that defines the outline of the acoustic material main body 12, and the intersection 1402 where the ends of adjacent reinforcing plates 14 intersect at right angles is located near a mounting hole not shown. The remaining two reinforcing plates 14 are arranged so as to pass through the centers of two opposing sides of the square 1210, and the intersection 1402 where the longitudinal centers of these two reinforcing plates 14 intersect at right angles is located at the center of the square 1210, and the intersection 1402 where both longitudinal ends of these two reinforcing plates 14 intersect at right angles with the four reinforcing plates 14 arranged parallel to the four sides is located at the longitudinal center of the reinforcing plates 14 arranged parallel to the four sides. Therefore, the four reinforcing plates 14 arranged parallel to the four sides of the square 1210 that defines the outline of the acoustic material body 12, and the remaining two reinforcing plates 14, form four square frame-shaped closed cross-sectional structures with dimensions smaller than the square 1210 that defines the outline of the acoustic material body 12 when viewed from the thickness T2 direction of the acoustic material body 12, and the centers of these four closed cross-sectional structures are located at points that coincide with the center of the square 1210 that defines the outline of the acoustic material body 12.

[0022] Therefore, in the fourth embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical with respect to a center line that passes through the center of the acoustic material body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetrical with respect to the intersection of two center lines connecting the centers of two opposing sides of the acoustic material body 12, i.e., the center of the square 1210. According to the acoustic material 10D of the fourth embodiment, the number of closed cross-sectional structures is increased compared to the first embodiment, which is advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material 10D compared to the first embodiment, and is advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10D.

[0023] (Fifth embodiment) Next, a fifth embodiment will be described with reference to FIG. The fifth embodiment of acoustic material 10E shown in Figure 7 uses one fifth reinforcing plate 14E whose length is equal to one side of a square 1210 that defines the outline of the acoustic material main body 12, two sixth reinforcing plates 14F that are slightly shorter than one side of the square 1210, and one seventh reinforcing plate 14G that is shorter than the sixth reinforcing plate 14F. The fifth reinforcing plate 14E is disposed in the vicinity of one side of the square 1210 so as to extend parallel to this side. The seventh reinforcing plate 14G is disposed so as to extend in parallel to one side of the square 1210 in the vicinity of the side opposite to the side on which the fifth reinforcing plate 14E is disposed. The two sixth reinforcing plates 14F are arranged so as to intersect with the fifth reinforcing plate 14E and the seventh reinforcing plate 14G, and the distance between the two sixth reinforcing plates 14F gradually increases from the seventh reinforcing plate 14G to the fifth reinforcing plate 14E. The two sixth reinforcing plates 14F are arranged in a shape that is linearly symmetrical with respect to an imaginary line connecting the center of one side of the square 1210 in which the fifth reinforcing plate 14E is arranged and the center of one side of the square 1210 in which the seventh reinforcing plate 14G is arranged. Therefore, when viewed from the thickness T2 direction of the acoustic material main body 12, the four reinforcing plates 14 form a trapezoidal frame-shaped closed cross-sectional structure, and the center of this closed cross-sectional structure is located at a point that approximately coincides with the center of the square 1210 that forms the outline of the acoustic material main body 12. The two mounting holes (not shown) are located near the intersection 1402 where both ends of the fifth reinforcing plate 14E intersect with the two sixth reinforcing plates 14F, and the remaining two mounting holes are located near both longitudinal ends of the seventh reinforcing plate 14G.

[0024] According to this acoustic material 10E of the fifth embodiment, the bending rigidity of the acoustic material 10E provided with the closed cross-sectional structure is set to be higher than other parts of the acoustic material 10E. Therefore, when acoustic material 10E is attached to a structure, if the pressure acting on a trapezoidal frame-shaped portion located approximately in the center of acoustic material main body 12 is higher than the pressure acting on other portions of acoustic material 10E, attaching acoustic material 10E to the structure so that the closed cross-sectional structure is located at the portion where the pressure is applied is advantageous for ensuring both the bending rigidity and acoustic performance of acoustic material 10E, and is advantageous for achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10E.

[0025] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIG. In the sixth embodiment of the acoustic material 10F shown in Figure 8, two eighth reinforcing plates 14H of length equal to one side of the square 1210 that defines the outline of the acoustic material main body 12, and two ninth reinforcing plates 14I extending in an arc shape and shorter than one side of the square 1210 are used. The two eighth reinforcing plates 14H are disposed in the vicinity of two opposing sides of the square 1210 so as to extend parallel to one of the sides. The two ninth reinforcing plates 14I are arranged so as to intersect with the two eighth reinforcing plates 14H at locations spaced apart in the longitudinal direction of the two eighth reinforcing plates 14H, and therefore four intersections 1402 are provided where the two eighth reinforcing plates 14H and the two ninth reinforcing plates 14I intersect. Two eighth reinforcing plates 14H and two ninth reinforcing plates 14I form a frame-shaped closed cross-sectional structure, which is configured in a shape that is symmetrical with respect to a virtual line connecting the centers of the two sides of the square 1210 to which the ninth reinforcing plates 14I face. Furthermore, the center of this closed cross-sectional structure is located at a point displaced from the center of the square 1210 that defines the outline of the acoustic material body 12 along a center line that passes through the center of the acoustic material body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material body 12.

[0026] According to such an acoustic material 10F of the sixth embodiment, the bending rigidity of the acoustic material 10F provided with the closed cross-sectional structure is set to be higher than other parts of the acoustic material 10F. Therefore, when acoustic material 10F is attached to a structure, if the pressure acting on an approximately elongated area located at a point displaced from the center of the square 1210 that defines the outline of the acoustic material main body 12 is higher than the pressure acting on other points of acoustic material 10F, attaching acoustic material 10F to the structure so that a closed cross-sectional structure is located at the point where that pressure is applied will be advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10F, and will be advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10F.

[0027] (Seventh embodiment) Next, a seventh embodiment will be described with reference to FIG. In an acoustic material 10G of the seventh embodiment shown in FIG. 9, four reinforcing plates 14 having a length equal to one side of a square 1210 that defines the contour of the acoustic material body 12 are used. A tenth reinforcing plate 14J, which is one of two of the four reinforcing plates 14, is disposed in the vicinity of two opposing sides of the square 1210 so as to extend parallel to one of these sides. The remaining two reinforcing plates 14, the eleventh reinforcing plate 14K, are arranged parallel to each other so as to extend diagonally relative to one side of the square 1210, and both ends of the two eleventh reinforcing plates 14K are arranged to intersect with the two tenth reinforcing plates 14J, and intersection portions 1402 are provided at both ends of the eleventh reinforcing plate 14K. Therefore, when viewed from the thickness T2 direction of the acoustic material main body 12, the four reinforcing plates 14 form a parallelogram frame-shaped closed cross-sectional structure, and the center of this frame-shaped closed cross-sectional structure is located at a point that approximately coincides with the center of the square 1210 that forms the outline of the acoustic material main body 12. The four mounting holes (not shown) are located near both ends of the tenth reinforcing plate 14J.

[0028] According to this acoustic material 10G of the seventh embodiment, the bending rigidity of the acoustic material 10G provided with the parallelogram closed cross-sectional structure is set to be higher than other parts of the acoustic material 10G. Therefore, when the acoustic material 10G is attached to a structure and the pressure acting on a parallelogram located approximately in the center of the acoustic material main body 12 is higher than the pressure acting on other parts of the acoustic material 10G, attaching the acoustic material 10G to the structure so that the closed cross-sectional structure is located at the point where the pressure is applied is advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material 10G, and is advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10G.

[0029] (Eighth embodiment) Next, an eighth embodiment will be described with reference to FIG. In the eighth embodiment of acoustic material 10H shown in Figure 10, a 12th reinforcing plate 14L that is shorter than one side of the square 1210 that defines the outline of the acoustic material main body 12, a 13th reinforcing plate 14M that is slightly shorter than the 12th reinforcing plate 14L, a 14th reinforcing plate 14N that is slightly shorter than the 13th reinforcing plate 14M, and a 15th reinforcing plate 14O that is shorter than the 14th reinforcing plate 14N are used. The reinforcing plates 14 are arranged in a trapezoidal frame shape so that they are not parallel to any of the four sides of the square 1210 that defines the outline of the acoustic material main body 12, and four intersections 1402 are provided where adjacent reinforcing plates 14 intersect, with a trapezoidal frame-shaped closed cross-sectional structure being provided inside the four reinforcing plates 14. The center of this trapezoid closed cross-sectional structure is located at a point displaced from the center of the square 1210.

[0030] According to the acoustic material 10H of the eighth embodiment, the flexural rigidity of the acoustic material 10H having a trapezoidal closed cross-sectional structure is set to be higher than other portions of the acoustic material 10H. Therefore, when acoustic material 10H is attached to a structure and the pressure acting on a trapezoidal portion displaced from approximately the center of acoustic material main body 12 is higher than the pressure acting on other portions of acoustic material 10H, attaching acoustic material 10H to the structure so that the closed cross-sectional structure is located at the portion where the pressure is applied is advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10H, and is advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10H.

[0031] Ninth embodiment Next, a ninth embodiment will be described with reference to FIG. In the ninth embodiment of acoustic material 10I shown in Figure 11, eight reinforcing plates 14 of approximately the same length, which is shorter than one side of the square 1210 that defines the outline of the acoustic material main body 12, are used, and the reinforcing plates 14 are arranged so that their longitudinal ends cross to form a regular octagonal frame-shaped closed cross-sectional structure. The center of the closed cross-sectional structure and the center of the square 1210 that defines the outline of the acoustic material body 12 are located at the same point. Therefore, in the ninth embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical about a center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetrical about the center of the acoustic material main body 12.

[0032] According to the acoustic material 10I of the ninth embodiment, a larger number of reinforcing plates 14 are used compared to the first embodiment, which is more advantageous in terms of ensuring the bending rigidity of the acoustic material 10I, and more advantageous in terms of ensuring bending rigidity in all directions when torsional stress occurs in the acoustic material 10I. Therefore, it is more advantageous in terms of suppressing the amount of deformation and displacement (distortion) of the acoustic material 10I when pressure is applied to the acoustic material 10I.

[0033] (Tenth embodiment) Next, a tenth embodiment will be described with reference to FIG. An acoustic material 10J according to a tenth embodiment shown in FIG. 12 is a modified example of the first embodiment. In other words, in the first embodiment, the four reinforcing plates 14 are arranged parallel to each of the four sides of the square 1210 near the four sides, but in the tenth embodiment, both ends of the reinforcing plates 14 are extended to the four end faces 1220 of the acoustic material main body 12. An attachment hole (not shown) is located near an intersection 1402 where both ends of adjacent reinforcing plates 14 intersect. Further, two reinforcing plates 14 are provided crosswise so as to connect mutually opposing corners 1202 of the square frame-like closed cross-sectional structure formed by the four reinforcing plates 14 . An intersection 1402 where the two reinforcing plates 14 intersect in a cross shape is located at a point that coincides with the center of the square 1210 . Therefore, the square closed cross-sectional structure is divided by the two reinforcing plates 14 into four isosceles triangular frame-shaped closed cross-sectional structures. Therefore, in this embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical with respect to a center line that passes through the center of the acoustic material body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetric with respect to the intersection of the two diagonals of the acoustic material body 12.

[0034] According to the acoustic material 10J of the tenth embodiment, the number of closed cross-sectional structures used is greater than that of the first embodiment, which is more advantageous in terms of ensuring the bending rigidity of the acoustic material 10J and in terms of ensuring the bending rigidity in all directions when torsional stress occurs in the acoustic material 10J. Therefore, it is more advantageous in terms of suppressing the deformation amount and displacement amount (distortion) of the acoustic material 10J when pressure is applied to the acoustic material 10J.

[0035] (Eleventh embodiment) Next, an eleventh embodiment will be described with reference to FIGS. In an acoustic material 10K according to an eleventh embodiment shown in Figs. 13 and 14, mounting holes (not shown) are formed through the four corners 1202 of the acoustic material body 12, similar to the first embodiment. The acoustic material 10K of the eleventh embodiment is provided with four reinforcing plates 14 of approximately the same shape. The reinforcing plate 14 has a thickness T1, a height H1 that is greater than the thickness T1, and a length L1 that is greater than the height H1, and is in the form of an elongated plate. The height H1 of the reinforcing plate 14 is formed to have the same dimensions as the thickness T2 of the acoustic material body 12, and the length L1 of the reinforcing plate 14 is formed to have approximately the same dimensions as the length of one side of the square 1210 that defines the outline of the acoustic material body 12. The four reinforcing plates 14 are arranged with their height H1 direction aligned with the thickness T2 direction of the acoustic material main body 12, covering the four end faces 1220 located at both ends of the acoustic material main body 12 in the width W2 direction and both ends of the length L2 direction. That is, the reinforcing plate 14 is provided so that its height H1 direction is aligned with the thickness T2 direction of the acoustic material body 12 and covers the entire outer circumferential surface of the acoustic material body 12. The four reinforcing plates 14 may be attached to the end faces 1220 by using an adhesive, or by using bolts that pass through the reinforcing plates 14, or in any other manner. A square frame-shaped closed cross-sectional structure surrounded by the four reinforcing plates 14 is formed. Therefore, in this embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical with respect to a center line that passes through the center of the acoustic material body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetric with respect to the intersection of the two diagonals of the acoustic material body 12.

[0036] According to the acoustic material 10K of the 11th embodiment, the same effects as those of the first embodiment are achieved, and it is more advantageous in ensuring bending rigidity in all directions when torsional stress occurs in the acoustic material 10K, and it is more advantageous in suppressing the deformation and displacement (distortion) of the acoustic material 10K when pressure is applied to the acoustic material 10K. The reinforcing plate 14 may be formed integrally using a mold, or the like. In this case, the number of reinforcing plates 14 will be one, in the shape of a square frame.

[0037] (Twelfth embodiment) Next, a twelfth embodiment will be described with reference to FIG. In the acoustic material 10L of the 12th embodiment shown in Figure 15, four reinforcing plates 14 of the same length are used, and the length L1 of each reinforcing plate 14 is formed to be approximately the same length as one side of the square 1210 that defines the outline of the acoustic material main body 12. The four reinforcing plates 14 are arranged in parallel, two at a time, so that the square 1210 that outlines the acoustic material body 12 is divided into nine squares of the same shape and size, and both ends of each reinforcing plate 14 are located on the same plane as the end face of the acoustic material body 12. In the twelfth embodiment, a square frame-shaped closed cross-sectional structure having a size 1 / 9 of the square 1210 that defines the outline of the acoustic material body 12 is formed in the center of the acoustic material body 12 by four reinforcing plates 14. The center of this closed cross-sectional structure is located at a position that coincides with the center of the acoustic material body 12, and in this embodiment, it is located at a position where the center of the closed cross-sectional structure and the center of the acoustic material body 12 coincide with each other. Therefore, in the 12th embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical about the center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetrical about the center of the acoustic material main body 12.

[0038] According to the twelfth embodiment, compared to the first embodiment, four reinforcing plates 14 are arranged inside the acoustic material main body 12, which is more advantageous in ensuring bending rigidity in all directions when torsional stress occurs in the acoustic material 10L. Therefore, it is more advantageous in suppressing the amount of deformation and displacement (distortion) of the acoustic material 10L when pressure is applied to the acoustic material 10L, and is more advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10L.

[0039] (Thirteenth embodiment) Next, a thirteenth embodiment will be described with reference to FIG. An acoustic material 10M according to the thirteenth embodiment shown in FIG. 16 is a modified example of the acoustic material 10L according to the twelfth embodiment. In the acoustic material 10M of the 13th embodiment, as in the acoustic material 10L of the 12th embodiment, four reinforcing plates 14 of the same length are used, and the length L1 of each reinforcing plate 14 is formed to be approximately the same length as one side of the square 1210 that forms the outline of the acoustic material main body 12. In the 13th embodiment of the acoustic material 10M, two reinforcing plates 14 are arranged parallel to each other with a narrower gap than in the 12th embodiment, and are arranged so as to intersect in a cross shape at the center of the square 1210 that defines the outline of the acoustic material main body 12. The two reinforcing plates 14 arranged in parallel to each other are disposed so as to extend at equal intervals from an imaginary line X connecting the centers of two opposing sides of a square 1210 that defines the contour of the acoustic material body 12 . In the thirteenth embodiment, a square frame-shaped closed cross-sectional structure smaller than that of the twelfth embodiment is formed in the center of the acoustic material body 12 by four reinforcing plates 14 . The center of this closed cross-sectional structure is located at a position that coincides with the center of the acoustic material body 12, and in this embodiment, it is located at a position where the center of the closed cross-sectional structure and the center of the acoustic material body 12 coincide with each other. Therefore, in the thirteenth embodiment, the multiple reinforcing plates 14 are also arranged so as to have a shape that is symmetrical about a center line that passes through the center of the acoustic material main body 12 in the length L2 direction and extends in the width W2 direction of the acoustic material main body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to have a shape that is point-symmetrical about the center of the acoustic material main body 12.

[0040] According to the thirteenth embodiment, compared to the twelfth embodiment, the four reinforcing plates 14 are positioned further inward in the acoustic material main body 12, and the bending rigidity of the central part of the acoustic material 10M having a rectangular closed cross-sectional structure is set higher than that of other parts of the acoustic material 10M. Therefore, when the acoustic material 10M is attached to a structure and the pressure acting on the center of the acoustic material main body 12 is higher than the pressure acting on other parts of the acoustic material 10M, attaching the acoustic material 10M to the structure so that the closed cross-sectional structure is located at the part where the pressure is applied is advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material 10M, and is advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10M. This is therefore more advantageous in terms of ensuring bending rigidity in all directions when torsional stress occurs in the center of the acoustic material 10M, and is more advantageous in terms of suppressing the amount of deformation and displacement (distortion) of the acoustic material 10M when pressure is applied to the acoustic material 10M, and is more advantageous in terms of achieving both weight reduction of the structure and ensuring the acoustic performance of the acoustic material 10M. In this embodiment, the acoustic material body 12 is formed in the shape of a rectangular plate, but the shape of the acoustic material body 12 may be any shape that allows it to be arranged without gaps on the outer surface of the structure, and various conventional structures such as a parallelogram, trapezoid, or regular hexagon can be adopted. [Explanation of symbols]

[0041] 10A-10M Acoustic material 12 Acoustic material body 1202 Corner 1210 Square that forms the outline of the acoustic material body 1220 End face 14 Reinforcement plate 14A-14O 1st to 15th reinforcement plates 1402 Intersection 1410 Missing part 16 Mounting holes T1 Thickness of the stiffener H1 Height of the reinforcing plate L1 Length of the reinforcing plate T2 Thickness of acoustic material body W2 Width of acoustic material body L2 Length of the acoustic material body X Virtual Line

Claims

1. A plate-shaped acoustic material body having a thickness and formed of an acoustic material having a predetermined acoustic performance; The acoustic material body is made of a material having a higher rigidity than the acoustic material body, and has a thickness, a height that is greater than the thickness, and a length that is greater than the height. The acoustic material body is embedded with a plurality of elongated plate-like reinforcing plates. The plurality of reinforcing plates are arranged such that the height direction of the reinforcing plate is aligned with the thickness direction of the acoustic material body, and both ends of the reinforcing body in the height direction are positioned at positions away from both sides of the acoustic material body in the thickness direction, The multiple reinforcing plates are arranged to intersect with each other, so that a closed cross-sectional structure surrounded by the multiple reinforcing plates is formed when viewed from the thickness direction of the acoustic material body. An acoustic material characterized by:

2. The center of the closed cross-sectional structure is located at a position that coincides with the center of the contour of the acoustic material body.

2. The acoustic material according to claim 1.

3. The acoustic material body has a width and a length greater than the thickness and has a rectangular plate shape, The plurality of reinforcing plates are arranged so as to be symmetrical with respect to a center line that passes through the center of the length direction of the acoustic material body and extends in the width direction of the acoustic material body, 2. The acoustic material according to claim 1.

4. The acoustic material body has a rectangular plate shape, The plurality of reinforcing plates are arranged so as to have a point-symmetric shape with respect to the intersection of two diagonals of the rectangle that defines the contour of the acoustic material body.

2. The acoustic material according to claim 1.

5. The acoustic material body has a rectangular plate shape, The reinforcing plate is arranged in four pieces parallel to the four sides of the rectangle that defines the outline of the acoustic material body, An intersection portion where adjacent reinforcing plates intersect is located near a corner of the rectangle.

2. The acoustic material according to claim 1.

6. A plate-shaped acoustic material body having a thickness and formed of an acoustic material having a predetermined acoustic performance; The acoustic material body is made of a material having a higher rigidity than the acoustic material body, and the acoustic material body has a thickness, a height greater than the thickness, and a length greater than the height. The reinforcing plate is provided so that its height direction is aligned with the thickness direction of the acoustic material body and covers the entire outer circumferential surface of the acoustic material body, A closed cross-sectional structure is formed surrounded by the reinforcing plate. An acoustic material characterized by:

7. The reinforcing plate is formed of a material having acoustic properties similar to those of the acoustic material forming the acoustic body.

7. The acoustic material according to claim 1 or 6.

8. The acoustic material forming the acoustic body is a viscoelastic material, The reinforcing plate is made of FRP.

8. The acoustic material according to claim 7.

9. The acoustic material body has a rectangular plate shape, At each corner of the rectangular shape that defines the contour of the acoustic material body, a mounting hole is formed through the acoustic material body in the thickness direction.

7. The acoustic material according to claim 1 or 6.

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