Mounting structure of underwater acoustic material on surface to be mounted and structure covering surface to be mounted of underwater structure with underwater acoustic material, as well as underwater acoustic material

Abstract

To provide a mounting structure of an underwater acoustic material on a surface to be mounted of an underwater acoustic material that is advantageous in making mounting work more efficient while improving acoustic performance, and a structure covering a surface to be mounted of an underwater structure with an underwater acoustic material, as well as an underwater acoustic material.SOLUTION: In a state where a first underwater acoustic material 14A and a second underwater acoustic material 14B are alternately mounted in a vertical direction on a surface 12 to be mounted, a pair of surfaces (first inclined surfaces) 20A constituting a pair of legs of a first trapezoid 16A of the first underwater acoustic material 14A and a pair of surfaces (second inclined surfaces) 20B constituting a pair of legs of a second trapezoid 16B of the second underwater acoustic material 14B are tightly attached to each other, which eliminates necessity of work for filling a joint sealant into a gap between the underwater acoustic materials 14 arranged adjacently in the vertical direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a structure for attaching an underwater acoustic material to a mounting surface, a structure for covering a mounting surface of an underwater structure with an underwater acoustic material, and the underwater acoustic material. [Background technology]

[0002] Underwater acoustic materials have been provided that have sufficient acoustic performance to achieve sound insulation, sound absorption, or vibration suppression when attached to underwater structures such as the hull of a ship (see Patent Document 1). Known underwater acoustic materials include those made of elastic material and having a rectangular plate shape with a uniform thickness. A plurality of underwater acoustic materials are then arranged vertically and horizontally, and the back surface, which is one of the two surfaces in the thickness direction, is superimposed on the surface to be attached of the underwater structure. When installing underwater acoustic materials, it is necessary to fill and seal the gaps that occur between the four sides of adjacent underwater acoustic materials with a joint material made of rubber or silicone material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-227702 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional technology, the joint material does not have the same acoustic performance as the underwater acoustic material, so there is a concern that the acoustic performance will be reduced by an amount equivalent to the area of ​​the joint material. Furthermore, the installation of the underwater acoustic material requires the filling of joint material, which is disadvantageous in terms of improving the efficiency of the installation of the underwater acoustic material. The present invention was devised in consideration of the above circumstances, and its object is to provide an attachment structure for an underwater acoustic material to an attachment surface, which is advantageous in improving acoustic performance while making attachment work more efficient, a structure for covering the attachment surface of an underwater structure with an underwater acoustic material, and an underwater acoustic material. [Means for solving the problem]

[0005] In order to achieve the above object, one embodiment of the present invention is a mounting structure for an underwater acoustic material to a mounting surface of an underwater structure, the underwater acoustic material having a plate shape made of an elastic material, one of both surfaces in the thickness direction of the underwater structure being formed as a rectangular front surface and the other surface being formed as a rectangular back surface, the back surface being mounted in a line either up and down or horizontally on the mounting surface of the underwater structure, wherein a cross-sectional shape obtained by cutting the underwater acoustic material in the thickness direction from the front surface to the back surface along an imaginary line parallel to one side of the rectangle of the surface that extends in one of the up and down direction or the horizontal direction is a first trapezoid with the front surface as the lower base and the back surface as the upper base, and the cross-sectional shape obtained by cutting the underwater acoustic material in the thickness direction from the front surface to the back surface along an imaginary line parallel to one side of the rectangle of the surface that extends in the other of the up and down direction or the horizontal direction is a rectangle, The present invention is characterized in that a plurality of second underwater acoustic materials are provided, each having a cross-sectional shape that forms a second trapezoid with the surface as the upper base and the back surface as the lower base, and a cross-sectional shape that forms a rectangle when cut in the thickness direction along an imaginary line that extends from the surface to the back surface in the other of the vertical direction or the horizontal direction and is parallel to one side of the rectangle on the surface, the cross-sectional shape being rectangular; the first underwater acoustic material and the second underwater acoustic material have mounting holes that penetrate through them in the thickness direction and are formed as elongated holes that are long in either the vertical direction or the horizontal direction for attaching the first underwater acoustic material and the second underwater acoustic material to the mounting surface, and stud bolts that protrude from the mounting surface are connected within the elongated holes, so that the first underwater acoustic material and the second underwater acoustic material are attached alternately to the mounting surface in either the vertical direction or the horizontal direction, and a pair of surfaces that form a pair of legs of the first trapezoid of the first underwater acoustic material and a pair of surfaces that form a pair of legs of the second trapezoid of the second underwater acoustic material are in close contact with each other. In one embodiment of the present invention, a plate-like structure is provided which is made of an elastic material, one of both surfaces in the thickness direction of the structure being formed as a rectangular front surface and the other surface being formed as a rectangular back surface, the back surface being attached to a mounting surface of an underwater structure and covering the mounting surface with the underwater acoustic material, and the cross-sectional shape cut in the thickness direction along an imaginary line which extends from the front surface to the back surface in either the vertical direction or the horizontal direction and is parallel to one side of the rectangle of the front surface is a bottom base and the back surface is an upper base a plurality of first underwater acoustic materials each having a rectangular cross section in the thickness direction along an imaginary line extending from the front surface to the back surface in the other of the vertical direction or the horizontal direction and parallel to one side of the rectangle on the front surface; a plurality of first underwater acoustic materials each having a rectangular cross section in the thickness direction along an imaginary line extending from the front surface to the back surface in the other of the vertical direction or the horizontal direction and parallel to one side of the rectangle on the front surface; a second trapezoid having the front surface as an upper base and the back surface as a lower base; Alternatively, a plurality of second underwater acoustic materials are provided, each having a rectangular cross-sectional shape when cut in the thickness direction by an imaginary line parallel to one side of the rectangle on the surface extending in the other horizontal direction, and the first and second underwater acoustic materials have mounting holes that penetrate them in the thickness direction and are formed as long holes that are long in either the vertical or horizontal direction for attaching the first and second underwater acoustic materials to the mounting surface, and stud bolts protruding from the mounting surface are connected within the long holes, so that the first and second underwater acoustic materials are attached alternately in either the vertical or horizontal direction to the mounting surface, and a pair of surfaces that form a pair of legs of the first trapezoid of the first underwater acoustic material and a pair of surfaces that form a pair of legs of the second trapezoid of the second underwater acoustic material are in close contact to form an acoustic material row that extends in either the vertical or horizontal direction, and a plurality of the acoustic material rows are provided with gaps in the other of the vertical or horizontal direction, and the gaps are closed with joint material. Further, one embodiment of the present invention is an underwater acoustic material having a plate shape made of an elastic material, one of both surfaces in a thickness direction of which is formed as a rectangular front surface and the other surface is formed as a rectangular back surface, the underwater acoustic material being composed of a first underwater acoustic material and a second underwater acoustic material, the cross section of the first underwater acoustic material being cut in the thickness direction along an imaginary line extending from the front surface to the back surface in one of the vertical direction or the horizontal direction and parallel to one side of the rectangle of the front surface being a first trapezoid with the front surface as a lower base and the back surface being an upper base, and the cross section of the first underwater acoustic material being cut in the thickness direction along an imaginary line extending from the front surface to the back surface in the other of the vertical direction or the horizontal direction being parallel to one side of the rectangle of the front surface being a first trapezoid with the front surface as a lower base and the back surface being an upper base The second underwater acoustic material has a rectangular surface shape, and the mounting holes penetrating in the thickness direction are formed as long holes that are long in either the vertical or horizontal direction, and the cross-sectional shape of the second underwater acoustic material when cut in the thickness direction by an imaginary line parallel to one side of the rectangle on the surface that extends from the front surface to the back surface in either the vertical or horizontal direction is a second trapezoid with the front surface as the upper base and the back surface as the lower base, and the cross-sectional shape when cut in the thickness direction by an imaginary line parallel to one side of the rectangle on the surface that extends from the front surface to the back surface in the other of the vertical or horizontal direction is a rectangle, and the mounting holes penetrating in the thickness direction are formed as long holes that are long in either the vertical or horizontal direction. In addition, one embodiment of the present invention is characterized in that when the angle formed between a pair of surfaces constituting a pair of legs of the first trapezoid of the first underwater acoustic material and the front surface is defined as a first inclination angle θ1, and the angle formed between a pair of surfaces constituting a pair of legs of the second trapezoid of the second underwater acoustic material and the back surface is defined as a second inclination angle θ2, the first inclination angle θ1 and the second inclination angle θ2 are greater than or equal to 45° and less than 90°. [Effects of the Invention]

[0006] According to the mounting structure for an underwater acoustic material to a mounting surface, the structure for covering the mounting surface of an underwater structure with an underwater acoustic material, and the underwater acoustic material of one embodiment of the present invention, when the first underwater acoustic material and the second underwater acoustic material are mounted alternately in the vertical direction on the mounting surface, a pair of surfaces constituting a pair of legs of the first trapezoid of the first underwater acoustic material and a pair of surfaces constituting a pair of legs of the second trapezoid of the second underwater acoustic material are in tight contact with each other, thereby eliminating the need to fill gaps between adjacent underwater acoustic materials in the vertical or horizontal direction with joint material. As a result, of the conventional work of filling the gaps between adjacent underwater acoustic materials in the horizontal direction with joint material, and the work of filling the gaps between adjacent underwater acoustic materials in the vertical direction with joint material, it is possible to omit the work of filling one of the gaps, and the area of ​​the joint material can be reduced to half compared to the conventional work, which means that the decline in acoustic performance can be suppressed to half, which is advantageous in terms of improving acoustic performance compared to the conventional work. In addition, the work required to fill joints when installing underwater acoustic materials can be reduced by half, which is advantageous in reducing the cost of joints and improving the efficiency of the installation work for underwater acoustic materials. [Brief explanation of the drawings]

[0007] [Figure 1] 1A is a plan view of a first underwater acoustic material according to an embodiment, seen from the surface side; FIG. 1B is a cross-sectional view of (A) taken along line BB; and FIG. 1C is a cross-sectional view of (A) taken along line CC. [Figure 2] 1A is a plan view of the second underwater acoustic material according to the embodiment, seen from the surface side; FIG. 1B is a cross-sectional view of (A) taken along line BB; and FIG. 1C is a cross-sectional view of (A) taken along line CC. [Figure 3] (A) and (B) are cross-sectional views explaining the installation work of the first underwater acoustic material and the second underwater acoustic material to the installation surface in the embodiment, and (C) is a cross-sectional view showing the state after the first underwater acoustic material and the second underwater acoustic material have been installed to the installation surface. [Figure 4] This is a plan view of the first underwater acoustic material and the second underwater acoustic material after they have been attached to the attachment surface, viewed from the surface side. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes the structure for attaching the underwater acoustic material to the mounting surface, the structure for covering the mounting surface of the underwater structure with the underwater acoustic material, and the underwater acoustic material according to the embodiment. As shown in FIG. 3(C), the mounting surface 12 of the underwater structure 10, such as a ship's hull, to which the multiple underwater acoustic materials 14 are attached, is configured as a flat surface or a concavely curved surface or a convexly curved surface. The mounting surface 12 of the underwater structure 10 is covered with a plurality of underwater acoustic materials 14 .

[0009] As shown in Figure 3(C), the underwater acoustic material 14 is a plate made of an elastic material, and one of its two surfaces in the thickness direction, the rectangular back surface 1402, is attached to the mounting surface 12 and arranged vertically and horizontally. As the elastic material, various conventionally known elastic materials such as rubber and urethane can be used. In this embodiment, the underwater acoustic material 14 includes a plurality of first underwater acoustic materials 14A and a plurality of second underwater acoustic materials 14B having different shapes.

[0010] As shown in Figures 1(A), (B), and (C), the first underwater acoustic material 14A has a rectangular back surface 1402 and a rectangular front surface 1404 located opposite the back surface 1402 and having a larger outline than the back surface 1402. In this embodiment, we will explain the case where multiple first underwater acoustic materials 14A and multiple second underwater acoustic materials 14B are arranged in the vertical direction, so one of the vertical direction or the horizontal direction is the vertical direction and the other is the horizontal direction. The cross-sectional shape of the first underwater acoustic material 14A when cut in the thickness direction along an imaginary line parallel to one side of the rectangle of the surface 1404 extending vertically from the surface 1404 to the back surface 1402 is a first trapezoid 16A with the surface 1404 as the lower base and the back surface 1402 as the upper base, and the cross-sectional shape when cut in the thickness direction along an imaginary line parallel to one side of the rectangle of the surface 1404 extending horizontally from the surface 1404 to the back surface 1402 is a first rectangle 18A. Therefore, the first underwater acoustic material 14A has a pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A, and a pair of flat surfaces (first side surfaces) 22A that form opposing sides of the first rectangle 18A. Here, when the angles formed by a pair of faces (first inclined faces) 20A constituting a pair of legs of the first trapezoid 16A and the surface 1404 are each defined as a first inclination angle θ1, the two first inclination angles θ1 are equal to each other. Moreover, the two angles formed by the pair of surfaces (first inclined surfaces) 20A and the rear surface 1402 are equal to each other. The first underwater acoustic material 14A has a plurality of mounting holes 24 formed therethrough in the thickness T1 direction for mounting the first underwater acoustic material 14A to the mounting surface 12. In this embodiment, the mounting holes 24 are provided near the four corners of the surface 1404 of the first underwater acoustic material 14A, and each mounting hole 24 is provided as a long hole that is long in the vertical direction. The minor diameter of the elongated hole is larger than the diameter of the stud bolt, and for example, the minor diameter of the elongated hole is set to about 1.5 to 2 times the diameter of the stud bolt. A counterbore hole 2402 having a larger outline than the elongated hole is formed on the surface 1404 side of the mounting hole 24 . The stud bolt 26 protruding from the mounting surface 12 is inserted into the mounting hole 24, and a nut 30 is fastened to the tip of the stud bolt 26 via a washer 28 in the countersink hole 2402, thereby attaching the underwater acoustic material 14 to the mounting surface 12. At this time, the nut 30 and the tip of the stud bolt 26 are positioned lower than the surface 1404 of the underwater acoustic material 14, and the countersunk hole 2402 is closed by attaching a rubber cap (not shown) to the countersunk hole 2402, so that the surface 1404 of the cap is positioned on the same plane as the surface 1404 of the underwater acoustic material 14.

[0011] As shown in Figures 1(A), (B), and (C), the second underwater acoustic material 14B has a rectangular back surface 1402 and a rectangular front surface 1404 located opposite the back surface 1402 and having a smaller outline than the back surface 1402. Furthermore, the surface 1404 of the first underwater acoustic material 14A and the back surface 1402 of the second underwater acoustic material 14B are rectangular with the same shape and size, and the back surface 1402 of the first underwater acoustic material 14A and the surface 1404 of the second underwater acoustic material 14B are rectangular with the same shape and size. The cross-sectional shape of the second underwater acoustic material 14B when cut in the thickness direction along an imaginary line parallel to one side of the rectangle of the surface 1404 extending vertically from the surface 1404 to the back surface 1402 is a second trapezoid 16B with the surface 1404 as the upper base and the back surface 1402 as the lower base, and the cross-sectional shape when cut in the thickness direction along an imaginary line parallel to one side of the rectangle of the surface 1404 extending horizontally from the surface 1404 to the back surface 1402 is a second rectangle 18B. Therefore, the second underwater acoustic material 14B has a pair of surfaces (second inclined surfaces) 20B that form a pair of legs of the second trapezoid 16B, and a pair of flat surfaces (second side surfaces) 22B that form opposing sides of the rectangle. Here, when the angles formed by the pair of surfaces (second inclined surfaces) 20B constituting the pair of legs of the second trapezoid 16B and the back surface 1402 are each defined as a second inclination angle θ2, the two second inclination angles θ2 are equal to each other. Moreover, the two angles formed by the pair of surfaces (second inclined surfaces) 20B and the surface 1404 are equal to each other. Furthermore, the first inclination angle θ1 of the first underwater acoustic material 14B and the second inclination angle θ2 of the second underwater acoustic material 14B are the same angle. The second underwater acoustic material 14B has a plurality of mounting holes 24 formed therethrough in the thickness T2 direction for mounting the second underwater acoustic material 14B to the mounting surface 12. In this embodiment, the mounting holes 24 are provided near the four corners of the surface 1404 of the second underwater acoustic material 14B, and each mounting hole 24 is provided as a long hole that is long in the vertical direction, and a countersunk hole 2402 with a larger outline than the long hole is formed on the surface 1404 side of the mounting hole 24. The number and arrangement of the mounting holes 24 of the first underwater acoustic material 14A and the second underwater acoustic material 14B are not limited to those in this embodiment, but can be set as appropriate.

[0012] Next, the attachment of the first underwater acoustic material 14A and the second underwater acoustic material 14B to the attachment surface 12 will be described with reference to FIGS. In this embodiment, the rear surfaces 1402 of the first underwater acoustic material 14A and the second underwater acoustic material 14B are attached to the attachment surface 12 of the underwater structure 10 so as to be alternately arranged in the up-down direction. As shown in Figure 3(A), a pair of legs of the second trapezoid 16B are positioned above and below the second underwater acoustic material 14B, and more specifically, with the pair of second inclined surfaces 20B facing in the vertical direction, in other words, with the extension direction of the long holes facing in the vertical direction, the back surface 1402 of the second underwater acoustic material 14B is faced toward the mounting surface 12, and each stud bolt 26 is inserted into each mounting hole 24, and the second underwater acoustic material 14B is moved toward the mounting surface 12 until the back surface 1402 of the second underwater acoustic material 14B abuts against the mounting surface 12. Then, once the back surface 1402 of the second underwater acoustic material 14B abuts against the mounting surface 12, nuts 30 are tightened to the tip of each stud bolt 26 via a washer 28, in other words, the stud bolts 26 are connected within the long holes, so that the back surface 1402 of the second underwater acoustic material 14B abuts against the mounting surface 12 and the second underwater acoustic material 14B is attached to the mounting surface 12.

[0013] Next, the first underwater acoustic material 14A is attached adjacent to and above the second underwater acoustic material 14B. As shown in Figure 3(A), a pair of legs of the first trapezoid 16A are positioned above and below the first underwater acoustic material 14A, and more specifically, with the pair of first inclined surfaces 20A facing up and down, in other words, with the extension direction of the long holes facing up and down, the back surface 1402 of the first underwater acoustic material 14A is faced toward the mounting surface 12, and each stud bolt 26 is inserted into each mounting hole 24, and the first underwater acoustic material 14A is moved toward the mounting surface 12 until the back surface 1402 of the first underwater acoustic material 14A abuts against the mounting surface 12. 3(B), the back surface 1402 of the first underwater acoustic material 14A comes into contact with the mounting surface 12. At this time, because the mounting hole 24 of the first underwater acoustic material 14A is an ellipse that is long in the vertical direction, like the mounting hole 24 of the second underwater acoustic material 14B, the first underwater acoustic material 14A can move in the vertical direction relative to the stud bolt 26, and the first underwater acoustic material 14A is slid downward with the back surface 1402 of the first underwater acoustic material 14A in contact with the mounting surface 12. Then, a pair of surfaces (first inclined surfaces) 20A constituting a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A are brought into close contact with a pair of surfaces (second inclined surfaces) 20B constituting a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B. In this state, by tightening a nut 30 to the tip of each stud bolt 26 via a washer 28, in other words, by connecting the stud bolts 26 within the long holes, the back surface 1402 of the first underwater acoustic material 14A abuts against the mounting surface 12, and the first underwater acoustic material 14A is attached to the mounting surface 12.

[0014] Next, using the same procedure as above, the second underwater acoustic material 14B is attached above the first underwater acoustic material 14A, so that the pair of surfaces (first inclined surfaces) 20A that form the pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A are tightly fitted to the pair of surfaces (second inclined surfaces) 20B that form the pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B. As shown in FIG. 4, the second underwater acoustic materials 14B and the second underwater acoustic materials 14A are arranged alternately in the vertical direction and attached to the attachment surface 12 in this manner, thereby forming an acoustic material row 32 extending linearly in the vertical direction. Note that horizontal position adjustment is performed when attaching the first underwater acoustic material 14A and the second underwater acoustic material 14B to the attachment surface 12. As mentioned above, the minor diameter of the long holes is formed to be larger than the diameter of the stud bolt 26, so the horizontal position adjustment of the first underwater acoustic material 14A and the second underwater acoustic material 14B relative to the stud bolt 26 is possible within the range of the minor diameter of the long holes. In the acoustic material row 32 thus formed, a pair of sides that face each other in the horizontal direction of the rectangle on the surface 1404 of the first underwater acoustic material 14A and a pair of sides that face each other in the horizontal direction of the rectangle on the surface 1404 of the second underwater acoustic material 14B each form a single straight line extending in the vertical direction.

[0015] As shown in Figure 4, multiple such acoustic material rows 32 are arranged horizontally with gaps S between them, and the gaps S are sealed with joint material (not shown), and the mounting surface 12 of the underwater structure 10 is covered with underwater acoustic material 14. As with conventional joint materials, rubber or silicone materials are used.

[0016] According to this embodiment, when the first underwater acoustic material 14A and the second underwater acoustic material 14B are attached to the attachment surface 12 alternately in the vertical direction, a pair of surfaces (first inclined surfaces) 20A constituting a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and a pair of surfaces (second inclined surfaces) 20B constituting a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B are in close contact with each other, thereby eliminating the need to fill the gaps between adjacent underwater acoustic materials 14 in the vertical direction with joint material. Therefore, of the conventional work of filling the gaps between adjacent underwater acoustic materials 14 in the horizontal direction with joint material and the work of filling the gaps between adjacent underwater acoustic materials 14 in the vertical direction, the work of filling the gaps between adjacent underwater acoustic materials 14 in the vertical direction can be omitted, and the area of ​​the joint material can be reduced to half compared to the conventional work, which prevents the deterioration of acoustic performance from decreasing by half, which is advantageous in improving acoustic performance compared to the conventional work. Furthermore, the work of filling the joint material when installing the underwater acoustic material 14 can be reduced by half, which is advantageous in reducing the cost of the joint material and improving the efficiency of the installation work of the underwater acoustic material 14.

[0017] Furthermore, the first inclination angle θ1 of the first underwater acoustic material 14A and the second inclination angle θ2 of the second underwater acoustic material 14B are preferably equal to or greater than 45° and less than 90°. Water pressure is applied to the surface 1404 of the underwater acoustic material 14 covering the mounting surface 12 of the underwater structure. This water pressure acts in a direction to bring into close contact a pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and a pair of surfaces (second inclined surfaces) 20B that form a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B. When the first inclination angle θ1 and the second inclination angle θ2 are in the range of 45° or more and less than 90°, the water pressure applied to the surfaces 1404 of the first underwater acoustic material 14A and the second underwater acoustic material 14B acts in a direction intersecting the pair of faces (first inclined faces) 20A that constitute a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and the pair of faces (second inclined faces) 20B that constitute a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B, which is advantageous in that the water pressure acts effectively on these faces and brings these faces into more firm contact with each other. Therefore, this is advantageous in improving the acoustic performance of the underwater acoustic material 14, and also in improving the attachment strength of the underwater acoustic material 14 to the attachment surface 12, preventing the underwater acoustic material 14 from falling off from the attachment surface 12 and ensuring the attachment strength of the underwater acoustic material 14 to the attachment surface 12.

[0018] When the first inclination angle θ1 and the second inclination angle θ2 are below 45°, the thickness of the pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A that are located on the underwater side relative to the portion of the surfaces (second inclined surfaces) 20B that form a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B becomes thinner, and therefore the portion of the pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A becomes more likely to be deformed by water flow. As a result, the effect of ensuring close contact between a pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and a pair of surfaces (second inclined surfaces) 20B that form a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B is reduced, and although the effect of improving the acoustic performance of the underwater acoustic material 14 and the attachment strength of the underwater acoustic material 14 to the attachment surface 12 is improved compared to the conventional structure, it is reduced compared to when the first inclination angle θ1 and the second inclination angle θ2 are 45° or more.

[0019] When the first inclination angle θ1 and the second inclination angle θ2 are 90°, the water pressure applied to the surfaces 1404 of the first underwater acoustic material 14A and the second underwater acoustic material 14B acts approximately parallel to a pair of surfaces (first inclined surfaces) 20A that form a pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and a pair of surfaces (second inclined surfaces) 20B that form a pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B. Therefore, water pressure is less likely to act in the direction of bringing the surfaces into close contact, reducing the effect of bringing the surfaces into close contact, and although acoustic performance is improved compared to conventional structures, it is reduced compared to when the first inclination angle θ1 and the second inclination angle θ2 are less than 90°.

[0020] In this embodiment, the first underwater acoustic material 14A and the second underwater acoustic material 14B are attached alternately in the vertical direction on the attachment surface 12 of the underwater structure 10, but the first underwater acoustic material 14A and the second underwater acoustic material 14B may also be attached alternately in the horizontal direction on the attachment surface 12 of the underwater structure 10, in which case the pair of legs of the first trapezoid 16A of the first underwater acoustic material 14A and the pair of legs of the second trapezoid 16B of the second underwater acoustic material 14B are positioned at both ends in the horizontal direction, and the extension direction of the long holes that constitute the attachment hole 24 is directed horizontally. Of course, even if the first underwater acoustic material 14A and the second underwater acoustic material 14B are attached alternately in the horizontal direction on the attachment surface 12 of the underwater structure 10 in this manner, the same effect as in this embodiment can be achieved. [Explanation of symbols]

[0021] 10 Underwater structures 12 Mounting surface 14 Underwater acoustic materials 1402 Back side 1404 Surface 14A No. 1 underwater acoustic material 14B 2nd underwater acoustic material 16A 1st trapezoid 16B Second trapezoid 18A 1st rectangle 18B 2nd rectangle 20A 1st slope 20B 2nd slope 22A 1st side 22B 2nd side 24 mounting holes 240 Counterbore 26 stud bolt 28 Washer 30 nuts 32 Acoustic material row θ1 1st inclination angle θ2 2nd inclination angle S Gap

Claims

1. An underwater acoustic material mounting structure for a mounting surface of an underwater structure, the underwater acoustic material having a plate shape made of an elastic material, one of both surfaces in the thickness direction of the underwater acoustic material being formed as a rectangular front surface and the other surface being formed as a rectangular back surface, the back surface being mounted in a line either vertically or horizontally to the mounting surface of the underwater structure, a plurality of first underwater acoustic materials are provided, each having a cross-sectional shape that is a first trapezoid with the surface as a lower base and the back surface as an upper base, when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in one of the vertical direction and the horizontal direction and is parallel to one side of the rectangle on the surface; and a cross-sectional shape that is a rectangle when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in the other of the vertical direction and the horizontal direction, when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in the a plurality of second underwater acoustic materials are provided, each having a cross section in the thickness direction cut along a virtual line extending from the front surface to the back surface in one of the vertical direction and the horizontal direction and parallel to one side of the rectangle on the front surface, which forms a second trapezoid with the front surface as an upper base and the back surface as a lower base, and a cross section in the thickness direction cut along a virtual line extending from the front surface to the back surface in the other of the vertical direction and the horizontal direction and parallel to one side of the rectangle on the front surface, which forms a rectangle; The first underwater acoustic material and the second underwater acoustic material have mounting holes formed therethrough in a thickness direction thereof for mounting the first underwater acoustic material and the second underwater acoustic material to the mounting surface as long holes extending in either the vertical direction or the horizontal direction; The first underwater acoustic material and the second underwater acoustic material are attached alternately in either the vertical or horizontal direction to the mounting surface by connecting stud bolts protruding from the mounting surface within the long holes, and a pair of surfaces constituting a pair of legs of the first trapezoid of the first underwater acoustic material and a pair of surfaces constituting a pair of legs of the second trapezoid of the second underwater acoustic material are in close contact with each other. A mounting structure for an underwater acoustic material to a mounting surface.

2. A plate-like structure made of an elastic material, one of whose two surfaces in the thickness direction is formed as a rectangular front surface and the other surface is formed as a rectangular back surface, the back surface being attached to a mounting surface of an underwater structure, and the mounting surface being covered with the underwater acoustic material, a plurality of first underwater acoustic materials are provided, each having a cross-sectional shape that is a first trapezoid with the surface as a lower base and the back surface as an upper base, when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in one of the vertical direction and the horizontal direction and is parallel to one side of the rectangle on the surface; and a cross-sectional shape that is a rectangle when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in the other of the vertical direction and the horizontal direction, when cut in the thickness direction along a virtual line that extends from the front surface to the back surface in the a plurality of second underwater acoustic materials are provided, each having a cross section in the thickness direction cut along a virtual line extending from the front surface to the back surface in one of the vertical direction and the horizontal direction and parallel to one side of the rectangle on the front surface, which forms a second trapezoid with the front surface as an upper base and the back surface as a lower base, and a cross section in the thickness direction cut along a virtual line extending from the front surface to the back surface in the other of the vertical direction and the horizontal direction and parallel to one side of the rectangle on the front surface, which forms a rectangle; The first underwater acoustic material and the second underwater acoustic material have mounting holes formed therethrough in a thickness direction thereof for mounting the first underwater acoustic material and the second underwater acoustic material to the mounting surface as long holes extending in either the vertical direction or the horizontal direction; The stud bolts protruding from the mounting surface are coupled within the long holes, so that the first underwater acoustic material and the second underwater acoustic material are mounted alternately in either the vertical or horizontal direction relative to the mounting surface, and a pair of surfaces constituting a pair of legs of the first trapezoid of the first underwater acoustic material and a pair of surfaces constituting a pair of legs of the second trapezoid of the second underwater acoustic material are in close contact with each other, thereby forming an acoustic material row extending in either the vertical or horizontal direction, The acoustic material rows are provided in plural with gaps in the other of the vertical direction and the horizontal direction, The gap is closed with a joint material. A structure in which the mounting surface of an underwater structure is covered with an underwater acoustic material.

3. An underwater acoustic material having a plate shape made of an elastic material, one of both surfaces in the thickness direction of which is formed as a rectangular front surface and the other surface is formed as a rectangular back surface, The underwater acoustic material is composed of a first underwater acoustic material and a second underwater acoustic material, The first underwater acoustic material has a cross-sectional shape in the thickness direction cut along an imaginary line parallel to one side of the rectangle on the surface, extending from the front surface to the back surface in either the vertical direction or the horizontal direction, which forms a first trapezoid with the front surface as the lower base and the back surface as the upper base, and a cross-sectional shape in the thickness direction cut along an imaginary line parallel to one side of the rectangle on the surface, extending from the front surface to the back surface in the other of the vertical direction or the horizontal direction, which forms a rectangle, and a mounting hole penetrating through the thickness direction is formed as a long hole that is long in either the vertical direction or the horizontal direction, The second underwater acoustic material has a cross-sectional shape cut in the thickness direction along an imaginary line parallel to one side of the rectangle on the surface, extending from the front surface to the back surface in either the vertical or horizontal direction, which forms a second trapezoid with the front surface as the upper base and the back surface as the lower base, and a cross-sectional shape cut in the thickness direction along an imaginary line parallel to one side of the rectangle on the surface, extending from the front surface to the back surface in the other of the vertical or horizontal direction, which forms a rectangle, and the mounting hole penetrating in the thickness direction is formed as a long hole that is long in either the vertical or horizontal direction. An underwater acoustic material characterized by:

4. a first inclination angle θ1 is an angle formed by a pair of faces constituting a pair of legs of the first trapezoid of the first underwater acoustic member and the surface; When the angle formed by a pair of surfaces constituting a pair of legs of the second trapezoid of the second underwater acoustic material and the back surface is defined as a second inclination angle θ2, the first tilt angle θ1 and the second tilt angle θ2 are equal to or greater than 45° and less than 90°; 4. The underwater acoustic material according to claim 3.

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