Acoustic material

Abstract

To provide an acoustic material advantageous in securing of both flexural rigidity and acoustic performance.SOLUTION: 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 reinforcing plates 14 are arranged in a manner to 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 positioned away from both surfaces of the acoustic material body 12 in the direction of the thickness T2.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 body having a thickness formed from an acoustic material having a predetermined acoustic performance, and a reinforcing plate formed from a material having higher rigidity than the acoustic body, having a thickness, a height that is greater than the thickness, and a length that is greater than the height, and being embedded in the acoustic body, wherein the height direction of the reinforcing plate is arranged along the thickness direction of the acoustic body, and both ends of the height direction of the reinforcing body are located at a distance from both sides in the thickness direction of the acoustic body. Effect of the Invention

[0006] According to one embodiment of the present invention, the reinforcing plate is advantageous in ensuring the bending rigidity of the acoustic material. Furthermore, when viewed from the direction in which the sound waves are coming, the area of ​​the reinforcing plate occupies an extremely small proportion of the area of ​​the acoustic material itself, so the impact on the acoustic performance of the acoustic material, i.e., the reflection, absorption, and transmission of sound waves, is minimal. This is therefore advantageous in ensuring both the bending rigidity and acoustic performance of the acoustic material. In addition, at the part of the acoustic material body where the reinforcing plate is located, the acoustic material body is connected at both ends in the height direction of the reinforcing plate over the entire length of the reinforcing plate, and the acoustic material body is not divided by the reinforcing plate, which is advantageous in ensuring the durability 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. 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 mounting holes 16 may be provided at intervals on each side of the rectangle excluding the corners, or multiple mounting holes 16 may be provided in the center of the rectangle or around the center, and the positions 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 a higher rigidity than the acoustic material body 12 and is embedded in the acoustic material body 12. 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 reinforcing plate 14 is in the form of an elongated plate 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 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 material 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. Further, both ends of the reinforcing plate 14 in the length L1 direction are located away from the end faces of both ends of the acoustic material body 12 in the width W2 direction and the end faces of both ends in the length L2 direction. Therefore, the portions of the acoustic material body 12 located on both sides of the reinforcing plate 14 are connected at both ends of the reinforcing plate 14 in the height H1 direction, and also connected at both ends of the reinforcing plate 14 in the length L1 direction.

[0010] The reinforcing plates 14 are provided in two linearly extending pieces of the same shape. The acoustic material body 12 is formed in a square shape, and the two reinforcing plates 14 are arranged to a length that approximately connects opposing mounting holes 16 on the diagonals of the square, and are arranged so as to intersect perpendicularly with each other between the opposing mounting holes 16, forming a cross shape. Therefore, the length L1 of the reinforcing plate 14 is greater than one side of the square that the acoustic material body 12 presents. The intersection 1402 where the reinforcing plates 14 intersect is located approximately in the center of the square outline of the acoustic material body 12, and in this embodiment, is located at the center 1420 of the square. In addition, such a cross-shaped reinforcing plate 14 may be assembled in a cross shape via a cutout 1410 provided in the center of two reinforcing plates 14, as shown in Figures 3(A) and (B), and the cross shape may be maintained by an adhesive, or it may be molded as a single unit using a mold. 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 reinforcing plate 14 formed of a material having higher rigidity than the acoustic material main body 12 and having a long, thin plate shape is embedded in an acoustic material main body 12 formed of an acoustic material having predetermined acoustic performance, and 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 plate 14 in the height H1 direction are located at locations away from both sides of the acoustic material main body 12 in the thickness T2 direction. Therefore, the reinforcing plate 14 is advantageous in ensuring the bending rigidity of the acoustic material 10A. Furthermore, when viewed from the direction from which the sound waves arrive, the area of ​​the reinforcing plate 14 occupies a very small proportion of the area of ​​the acoustic material main body 12, so even though the reinforcing plate 14 is 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, at the part of the acoustic material main body 12 where the reinforcing plate 14 is located, the acoustic material main body 12 is connected at both ends in the height H1 direction of the reinforcing plate 14 over the entire length of 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] It should be noted that a single reinforcing plate 14 may be used, or multiple reinforcing plates 14 may be arranged without intersecting; however, when multiple reinforcing plates 14 are arranged in an intersecting manner, as in the present embodiment, the intersection portion 1402 has a large rigidity due to its structure itself, which is more advantageous in terms of ensuring the bending rigidity of the acoustic material 10A using the reinforcing plate 14.

[0013] Furthermore, in this embodiment, the intersection 1402 where multiple reinforcing plates 14 intersect is located approximately in the center of the contour of the acoustic material main body 12, so that the rigidity of the portion of the reinforcing plate 14 which is farthest from the four mounting holes 16 and most susceptible to deformation can be ensured, which is advantageous for using the acoustic material 10A itself as a structural member that constitutes a structure such as a hull.

[0014] 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.

[0015] 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.

[0016] In addition, in this embodiment, the mounting holes 16 of the acoustic material 10A are formed through the four corners 1202 of the acoustic material main body 12 in the thickness T2 direction of the acoustic material main body 12, and the reinforcing plate 14 extends to the vicinity of each opposing corner 1202 on the diagonal of the acoustic material main body 12.In this embodiment, the reinforcing plate 14 is provided to a length that almost connects the opposing mounting holes 16, so that a large length L1 can be ensured, which is more advantageous in terms of ensuring the bending rigidity of the acoustic material 10A. In addition, since the end of the reinforcing plate 14 extends to the periphery of the mounting hole 16, the rigidity of the acoustic material 10A around the mounting hole 16 is increased by the reinforcing plate 14, which is advantageous in ensuring the mounting strength of the acoustic material 10A to the structure.

[0017] 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.

[0018] (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, shape, and arrangement of the reinforcing plate 14 are different from those of the first embodiment. In the second embodiment of the acoustic material 10B shown in Figure 4, two reinforcing plates 14 are used, and the length L1 of each reinforcing plate 14 is formed to be slightly shorter than one side of the square that defines the outline of the acoustic material main body 12. In the embodiments described below, including this embodiment, the thickness, height, material, etc. of the reinforcing plate are the same as those in the first embodiment. The two reinforcing plates 14 are arranged on a virtual line connecting the centers of one of the opposing sides, and the intersection 1402 where the two reinforcing plates 14 intersect perpendicularly is located approximately in the center of the square that defines the outline of the acoustic material main body 12, and in this embodiment is located at the center 1420 of the square. 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 the 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. 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. An acoustic material 10C according to a third embodiment shown in FIG. 5 is a modified example of the first embodiment. The arrangement of the two reinforcing plates 14 is similar to that of the first embodiment, but the length L1 of the two reinforcing plates 14 is shorter than that of the reinforcing plates 14 of the acoustic material 10A of the first embodiment. Therefore, in the third embodiment, the multiple reinforcing plates 14 are also arranged so as to have a shape that is symmetrical with respect to the 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. The length L1 of the two reinforcing plates 14 is longer than half of one side of the square that defines the outline of the acoustic material body 12 and shorter than the dimension of one side of the square. Although the acoustic material 10C of the third embodiment has a slightly lower bending rigidity than the acoustic material 10A of the first embodiment, when viewed from the direction in which the sound waves arrive, the proportion of the area of ​​the reinforcing plate 14 to the area of ​​the acoustic material main body 12 is smaller, which is advantageous in ensuring the acoustic performance of the acoustic material 10C.

[0020] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. An acoustic material 10D according to a fourth embodiment shown in FIG. 6 is a modified example of the second embodiment. The arrangement of the two reinforcing plates 14 is similar to that of the second embodiment, but the length L1 of the two reinforcing plates 14 is shorter than that of the reinforcing plates 14 of the acoustic material 10B of the second embodiment. Therefore, in the fourth embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape that is symmetrical with respect to the 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. The length L1 of the two reinforcing plates 14 is slightly shorter than half of one side of the square that defines the outline of the acoustic material body 12. Although the acoustic material 10D of this fourth embodiment has a bending rigidity that is slightly lower than that of the acoustic material 10B of the second embodiment, when viewed from the direction in which the sound waves arrive, the proportion of the area of ​​the reinforcing plate 14 to the area of ​​the acoustic material main body 12 is smaller, which is advantageous in ensuring the acoustic performance of the acoustic material 10D.

[0021] (Fifth embodiment) Next, a fifth embodiment will be described with reference to FIG. An acoustic material 10E according to a fifth embodiment shown in FIG. 7 is a modified example of the first embodiment. The arrangement of the two reinforcing plates 14 is similar to that of the first embodiment, but the length L1 of one of the two reinforcing plates 14, reinforcing plate 14A, is formed with a dimension shorter than that of reinforcing plate 14 of acoustic material 10A in the first embodiment, and is formed with a dimension slightly shorter than 1 / 2 of one side of the square that defines the outline of the acoustic material main body 12. The length of the other reinforcing plate 14 is the same as that of the first embodiment. Therefore, in the fifth embodiment, the multiple reinforcing plates 14 are arranged so as to form a shape that is symmetrical with respect to the diagonals of the square that defines the outline of the acoustic material main body 12, and at the same time, the multiple reinforcing plates 14 are arranged so as to form a shape that is point-symmetric with respect to the intersection of the two diagonals of the acoustic material main body 12. Although the acoustic material 10E of the fifth embodiment has a slightly lower bending rigidity than the acoustic material 10A of the first embodiment, when viewed from the direction in which the sound waves arrive, the area of ​​the reinforcing plate 14 accounts for a smaller proportion of the area of ​​the acoustic material main body 12 than in the acoustic material 10A of the first embodiment, which is advantageous in ensuring the acoustic performance of the acoustic material 10E compared to the acoustic material 10A of the first embodiment.

[0022] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIG. An acoustic material 10F according to a sixth embodiment shown in FIG. 8 is a modified example of the second embodiment. The arrangement of the two reinforcing plates 14 is similar to that of the second embodiment, but one of the two reinforcing plates 14, reinforcing plate 14A, is formed with a length shorter than that of reinforcing plate 14 of acoustic material 10B in the second embodiment, and is formed with a length slightly shorter than 1 / 2 of one side of the square that defines the outline of the acoustic material main body 12. The length of the other reinforcing plate 14 is the same as that of the second embodiment. Therefore, in the sixth embodiment, the multiple reinforcing plates 14 are also arranged so as to have a shape that is symmetrical with respect to the 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. Although the acoustic material 10F of this sixth embodiment has a slightly lower bending rigidity than the acoustic material 10B of the second embodiment, when viewed from the direction in which the sound waves arrive, the area of ​​the reinforcing plate 14 accounts for a smaller proportion of the area of ​​the acoustic material main body 12 than the acoustic material 10B of the second embodiment, which is advantageous in ensuring the acoustic performance of the acoustic material 10F compared to the acoustic material 10B of the second embodiment.

[0023] (Seventh embodiment) Next, a seventh embodiment will be described with reference to FIG. An acoustic material 10G according to the seventh embodiment shown in FIG. 9 is a modified example of the first embodiment. The arrangement structure of the two reinforcing plates 14 is different from that of the first embodiment, and the length L1 of one of the two reinforcing plates 14, reinforcing plate 14A, is formed to be shorter than that of reinforcing plate 14 of acoustic material 10A in the first embodiment. The length L1 of one reinforcing plate 14A is slightly shorter than half of one side of the square that defines the outline of the acoustic material 10G, and the length L1 of the other reinforcing plate 14B is the same as in the first embodiment, and the other reinforcing plate 14B is arranged on the diagonal of the square as in the first embodiment. One reinforcing plate 14A is disposed close to a corner 1202 located at an end of the other reinforcing plate 14B in the extending direction, and is perpendicular to the other reinforcing plate 14. An intersection 1402 where one reinforcing plate 14A and the other reinforcing plate 14B intersect is disposed so as to be located on a diagonal of a small square obtained by dividing the square that defines the outline of the acoustic material 10G into four equal parts. Therefore, also in the seventh embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape symmetrical on the left and right sides with respect to the diagonal line of the acoustic material body 12 that passes through the extending direction of the other reinforcing plate 14B. According to this acoustic material 10G of the seventh embodiment, the bending rigidity of the acoustic material 10G at the location where one of the reinforcing plates 14A, which has a shorter length, is arranged is set to be higher than other locations of the acoustic material 10G. Therefore, when acoustic material 10G is attached to a structure, if the pressure acting on the small square parts of acoustic material 10G obtained by dividing the square that defines the outline of acoustic material 10G into four equal parts is higher than the pressure acting on other parts of acoustic material 10G, attaching acoustic material 10G to the structure so that one of reinforcing plates 14A is positioned at the part where that pressure is applied will be advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10G, and will be advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10G.

[0024] (Eighth embodiment) Next, an eighth embodiment will be described with reference to FIG. An acoustic material 10H according to an eighth embodiment shown in FIG. 10 is a modified example of the first embodiment. The arrangement of the two reinforcing plates 14 differs from that of the first embodiment, and the length L1 and shape of one of the two reinforcing plates 14, reinforcing plate 14A, differs from that of reinforcing plate 14 of acoustic material 10A in the first embodiment. The length L1 of one reinforcing plate 14A is greater than half of one side of the square that defines the outline of the acoustic material 10H, but shorter than one side, and the length L1 of the other reinforcing plate 14B is the same as in the first embodiment, and the other reinforcing plate 14B is arranged on the diagonal of the square, as in the first embodiment. One reinforcing plate 14A is formed in an arc shape, and the center of this reinforcing plate 14A in the length L1 direction is located at the center 1420 of the square that defines the outline of the acoustic material 10H, and intersects with the other reinforcing plate 14B. Therefore, also in the eighth embodiment, the multiple reinforcing plates 14 are arranged so as to have a shape symmetrical on the left and right sides with respect to the diagonal line of the acoustic material body 12 that passes through the extending direction of the other reinforcing plate 14B. According to such an acoustic material 10H of the eighth embodiment, the bending rigidity of the acoustic material 10H at the location where one of the reinforcing plates 14A, which has a shorter length, is arranged is set to be higher than the bending rigidity of the other locations of the acoustic material 10H. Therefore, when acoustic material 10H is attached to a structure, if the pressure acting on a portion of acoustic material 10H located on a circumference centered on square corner 1202 that defines the outline of acoustic material 10H is higher than the pressure acting on other portions of acoustic material 10H, attaching acoustic material 10H to the structure so that one of reinforcing plates 14A is positioned at the portion where that pressure is applied will be advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10H, and will be advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10H.

[0025] Ninth embodiment Next, a ninth embodiment will be described with reference to FIG. An acoustic material 10I according to a ninth embodiment shown in FIG. 11 is a modified example of the first embodiment. The arrangement structure of the two reinforcing plates 14 is different from that of the first embodiment, and the length L1 of the two reinforcing plates 14 is shorter than that of the reinforcing plate 14 of the acoustic material 10A of the first embodiment and longer than that of the reinforcing plate 14 of the acoustic material 10B of the second embodiment. The two reinforcing plates 14 have the same length L1, and the central portions of the two reinforcing plates 14 in the length L1 direction intersect to form an intersection 1402.This intersection 1402 is located approximately in the center of the square that defines the outline of the acoustic material 10I, and in this embodiment, the intersection 1402 is located at the center 1420 of the square. Of the angles θ1 and θ2 at which the two reinforcing plates 14 intersect, one angle θ1 is an acute angle, and the other angle θ2 is an obtuse angle. Therefore, in the ninth embodiment, the multiple reinforcing plates 14 are also arranged so as to be symmetrical with respect to an imaginary line connecting the centers of opposing sides of the square, and are also arranged so as to be point-symmetrical with respect to the center 1420 of the square. According to the acoustic material 10I of the ninth embodiment, the bending rigidity of the acoustic material 10I in the vicinity of the imaginary line connecting the centers of the opposing sides of the square is set to be higher than that of other parts of the acoustic material 10I. Therefore, when acoustic material 10I is attached to a structure, if the pressure acting on a point near the imaginary line connecting the centers of two opposing sides of the square that defines the outline of acoustic material 10I is higher than the pressure acting on other points of acoustic material 10I, attaching acoustic material 10I to the structure so that two reinforcing plates 14 are positioned at the points where that pressure is applied will be advantageous in ensuring both the bending rigidity and acoustic performance of acoustic material 10I, and will be advantageous in achieving both a lightweight structure and ensuring the acoustic performance of acoustic material 10I.

[0026] (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. The arrangement structure of the two reinforcing plates 14 is different from that of the first embodiment, and the length L1 of the two reinforcing plates 14 is shorter than that of the reinforcing plate 14 of the acoustic material 10A of the first embodiment and longer than that of the reinforcing plate 14 of the acoustic material 10B of the second embodiment. The two reinforcing plates 14 have the same length L1, and the two reinforcing plates 14 intersect at an intersection 1402 near one end in the length L1 direction.This intersection 1402 is located on the diagonal of the square, and is also located near one corner 1202 of the square that defines the outline of the acoustic material 10J. Of the angles θ3 and θ4 at which the two reinforcing plates 14 intersect, one angle θ3 is an acute angle, and the other angle θ4 is an obtuse angle. In the tenth embodiment, the two reinforcing plates 14 are also arranged so as to be symmetrical with respect to the diagonal of the square. According to such acoustic material 10J of the tenth embodiment, the bending rigidity of the acoustic material 10J at a location closer to one corner 1202 on the diagonal of the square is set to be higher than other locations of the acoustic material 10J. Therefore, when acoustic material 10J is attached to a structure, if the pressure acting on a point near one corner 1202 on the diagonal of the square that defines the outline of acoustic material 10J is higher than the pressure acting on other points of acoustic material 10J, attaching acoustic material 10J to the structure so that intersection 1402 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 10J, and will be advantageous in achieving both weight reduction of the structure and ensuring the acoustic performance of acoustic material 10J. 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]

[0027] 10A-10J Acoustic material 12 Acoustic material body 1202 Corner 14 Reinforcement plate 14A One side reinforcement plate 14B Other reinforcing plate 1402 Intersection 1410 Missing part 1420 Square Center 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 θ1-θ4 angle

Claims

1. A plate-shaped acoustic material body having a thickness and formed of an acoustic material having a predetermined acoustic performance; A reinforcing plate is formed of a material having a higher rigidity than the acoustic material body, has a thickness, a height dimension greater than the thickness, and a length dimension greater than the height, and is embedded in the acoustic material body. The reinforcing plate is disposed such that a height direction of the reinforcing plate is aligned with a thickness direction of the acoustic material body, Both ends of the reinforcing body in the height direction are located away from both sides of the acoustic material body in the thickness direction. An acoustic material characterized by:

2. The reinforcing plates are provided in a plurality of crossing positions.

2. The acoustic material according to claim 1.

3. The intersection where the multiple reinforcing plates intersect is located approximately at the center of the contour of the acoustic material body.

3. The acoustic material according to claim 2.

4. 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, 3. The acoustic material according to claim 2.

5. 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.

3. The acoustic material according to claim 2.

6. The acoustic material body has a rectangular plate shape, The reinforcing plate extends along a diagonal line of the rectangle that defines the contour of the acoustic body.

2. The acoustic material according to claim 1.

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

2. The acoustic material according to claim 1.

8. The acoustic material forming the acoustic body is a viscoelastic body, 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.

2. The acoustic material according to claim 1.

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