Vibration-damping sheet and method for manufacturing vibration-damping sheet

Abstract

To provide a vibration-damping sheet which is composed of a single plate-shaped member and which allows for easy control of a vibration frequency desired to be damped, as well as a method for manufacturing the vibration-damping sheet.SOLUTION: A vibration-damping sheet according to one embodiment of the present invention includes a base and a vibration-damping unit. The vibration-damping sheet is disposed on a surface of a vibration-damping target object and is composed of a single plate-shaped member. The base is disposed in contact with the surface of the vibration-damping target object and has an opening edge that forms an opening. The vibration-damping unit includes a weight located outside the opening, and a support with its one end being connected to the weight and the other end being connected to the opening edge so as to allow the weight to vibrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration-damping sheet and a method for manufacturing the vibration-damping sheet. [Background technology]

[0002] Parts and housings used in fields such as automobiles, aircraft, railroad vehicles, ships, home appliances, office automation equipment, building facilities, and machine tools are prone to vibration and noise during operation. In order to suppress the generation of such vibration and noise, it is known to attach a sheet that suppresses vibration and sound to the parts and housings.

[0003] For example, Patent Document 1 describes a sound-proof sheet member having a plurality of resonating parts provided on a sheet having rubber elasticity. The resonating part includes a base made of a polymeric material and a weight part having a mass greater than that of the base, and at least a part of the weight part is embedded in the base on the tip side of the resonating part. Patent Document 1 describes that when sound waves are incident from a noise source, the sheet and / or the resonating part resonate, and a part or all of the vibration stops near the resonant frequency of the sheet and / or the resonating part, resulting in high sound-proofing performance that surpasses the mass law. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 135409 Summary of the Invention [Problem to be solved by the invention]

[0005] The sound-proofing sheet member described in Patent Document 1 is effective in damping vibrations in the out-of-plane direction perpendicular to the sheet, but is insufficient in damping vibrations in the in-plane direction of the sheet. Also, in the shape of the resonating part of the sound-proofing sheet member described in Patent Document 1, the size of the base depends on the shape of the weight, so the options for vibration frequencies to be damped are limited.

[0006] In view of the above circumstances, an object of the present invention is to provide a vibration-damping sheet that is made of a single plate member and that allows easy control of the vibration frequency to be damped, and a method for manufacturing the vibration-damping sheet. [Means for solving the problem]

[0007] In order to achieve the above object, a vibration-damping sheet according to one embodiment of the present invention comprises a base and a vibration-damping unit. The vibration-damping sheet is placed on the surface of an object to be damped and is composed of a single plate-shaped member. The base is placed in contact with the surface of the object to be damped and has an opening edge that forms an opening. The vibration-damping unit has a weight portion located outside the opening, and a support portion having one end connected to the weight portion and the other end connected to the opening edge, allowing the weight portion to vibrate.

[0008] With this configuration, by adjusting the planar shape and dimensions of the support part and the weight part, the spring constant and the mass of the weight part can be adjusted, making it possible to easily optimize the natural frequency of the vibration control unit and to produce a vibration control sheet that can easily control the vibration frequency to be controlled.

[0009] The base may have one or more of the openings, and one or more of the vibration damping units may be connected to an edge of the opening that forms at least one of the openings. The planar shape of the weight portion may be a polygonal shape such as a rectangle, a substantially polygonal shape with rounded corners, a circular shape including an ellipse and a perfect circle, or the like.

[0010] The plurality of vibration damping units connected to the opening edge forming the at least one opening may include a first vibration damping unit and a second vibration damping unit whose support portions extend in different directions from each other.

[0011] The opening edge forming the at least one opening may have a polygonal shape having three or more sides, and the first vibration damping unit and the second vibration damping unit may be connected to different sides.

[0012] The base may include a picture-frame-shaped outer peripheral frame and an inner frame that defines multiple openings within the outer peripheral frame, and one or more of the vibration damping units may be connected to the opening edge that forms each opening.

[0013] The plurality of vibration-damping units provided on the vibration-damping sheet may include two vibration-damping units whose support portions extend in different directions.

[0014] The vibration damping unit may rise from a connection portion between the base portion and the support portion as a rising point and be positioned obliquely with respect to the surface of the object to be damped.

[0015] The vibration damping unit may be located within the opening formed by the opening edge to which the vibration damping unit is connected in a plan view.

[0016] The vibration-damping sheet may be made of metal.

[0017] The base may be thicker than the vibration damping unit.

[0018] In order to achieve the above object, a method for manufacturing a vibration-damping sheet according to one embodiment of the present invention involves etching or cutting a single plate-like member to form a base and a vibration-damping unit, and erecting the vibration-damping unit. The vibration-damping unit has a weight and a support. The base formed by the etching or cutting has an opening edge that forms an opening. The support formed by the etching or cutting has one end connected to the weight and the other end connected to the opening edge, allowing the weight to vibrate. In erecting the vibration-damping unit, the connection between the base and the support is used as a starting point for bending, and the vibration-damping unit is erected. Effect of the Invention

[0019] According to the present invention, it is possible to provide a vibration damping sheet that is made of a single plate member and that allows easy control of the vibration frequency to be damped. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view of a vibration damping sheet according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the vibration damping sheet of the first embodiment before bending. [Diagram 3] 1A is a partial perspective view of the vibration damping sheet of the first embodiment, and FIG. [Figure 4] 4 is a schematic cross-sectional view of a portion corresponding to line IV-IV in FIG. 2 when the vibration-damping sheet of the first embodiment is placed on the surface of an object to be vibration-damped. [Diagram 5] 4 is a manufacturing flow of the vibration damping sheet according to the first embodiment. [Figure 6] 4 is a manufacturing process diagram of the vibration damping sheet of the first embodiment, which is explained using a cross section of a portion corresponding to line IV-IV in FIG. 2. [Figure 7] FIG. 13(A) is a perspective view of a vibration-damping sheet according to a second embodiment, and FIG. [Figure 8] 6A to 6C are manufacturing process diagrams of the vibration damping sheet according to the second embodiment. [Figure 9] FIG. 11 is a plan view of the vibration damping sheet of the third embodiment before bending. [Figure 10] FIG. 11 is a partial perspective view of a vibration damping sheet according to a third embodiment. [Figure 11] FIG. 11 is a plan view of the vibration-damping sheet of the fourth embodiment before bending. [Figure 12] 1A is a partial cross-sectional view of a fifth embodiment of a vibration-damping sheet having a base thickness thicker than that of a vibration-damping unit when placed on an object to be damped, and FIG. 1B is a partial cross-sectional view of a fifth embodiment of a vibration-damping sheet when placed in a state prior to bending processing. [Figure 13] 1A to 1C are partial cross-sectional views illustrating examples of placement of a vibration-damping sheet on a vibration-damping object having a recess, where 1A and 1B are examples using the vibration-damping sheet of the first embodiment, and 1C is an example using the vibration-damping sheet of the first embodiment in a state prior to bending processing. [Figure 14] FIG. 1 is a schematic perspective view of a wind tunnel testing device. [Figure 15]FIG. 2 is a perspective view of a vibration-damping sheet including a plurality of vibration-damping units. [Figure 16] 16 is a graph showing the measurement results relating to an evaluation of vibration damping properties in the out-of-plane direction of the vibration damping sheet shown in FIG. 15 and a comparative flat plate. [Figure 17] 16 is a graph showing measurement results relating to an evaluation of sound insulation in the out-of-plane direction of the vibration damping sheet shown in FIG. 15. [Figure 18] 1 is a schematic partial cross-sectional view of an aircraft fuselage showing an application example of a vibration damping sheet according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are used for the configurations already described, and the description may be omitted. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for easy understanding, and do not limit the present disclosure unless otherwise specified.

[0022] The vibration-damping sheet and vibration-damping unit according to one embodiment of the present invention described below are placed in contact with the surface of an object to be damped, and reduce the vibration of the object to be damped. Examples of the object to be damped include parts and housings of automobiles, aircraft, railway vehicles, ships, home appliances, office automation equipment, building and housing equipment, machine tools, and other items used in applications where vibration occurs.

[0023] First Embodiment

[0024] [Vibration-damping sheet]

[0025] FIG. 1 is a perspective view of a vibration-damping sheet 1 according to a first embodiment. The vibration-damping sheet 1 of this embodiment can be manufactured, for example, by processing (etching, cutting, etc.) a single plate-like member 20 to form a base 2 and vibration-damping units 3, and then bending the vibration-damping units 3 to make them stand up. FIG. 2 is a plan view of the vibration-damping sheet 1 before bending. FIG. 3(A) is a partial perspective view of the vibration-damping sheet 1 in FIG. 1. FIG. 3(B) is a partial plan view of the vibration-damping sheet 1 before bending. FIG. 4 is a partial cross-sectional view of the vibration-damping sheet 1 after bending when it is placed on the surface 80 of an object 8 to be damped, and corresponds to the line IV-IV in FIG. 2.

[0026] Please refer to FIG. 1 to FIG. 4. The vibration-damping sheet 1 is composed of one plate-like member 20. The plate-like member 20 has a first surface 20a and a second surface 20b. As the plate-like member, a flat plate material having excellent processability that allows etching and bending can be used. In addition, the material required for the use of the vibration-damping sheet 1, for example, a material having flame retardancy, heat resistance, chemical resistance, mechanical strength, dimensional stability, etc., can be appropriately set. For example, as the material of the vibration-damping sheet 1, a metal plate made of a metal such as aluminum or an alloy such as stainless steel, a resin plate made of resin, etc. can be used. As the resin, a resin such as an acrylic resin, a silicone resin, or a general plastic material can be used. From the viewpoint of obtaining a vibration-damping sheet 1 having excellent weather resistance and flame retardancy, it is more preferable to use a metal plate. The outer shape of the vibration-damping sheet 1 is, for example, a square with a horizontal dimension b (dimension in the X-axis direction) of 100 mm and a vertical dimension c (dimension in the Y-axis direction) of 100 mm. The thickness a (dimension in the Z-axis direction) of the plate-like member 20 is, for example, about 0.8 mm to 1.0 mm. The external dimensions (length, width, thickness) of the vibration-damping sheet 1 are appropriately set depending on the material used, the purpose, the environment of the application, and the like. For example, when the space at the application location is small (environment of application), the size of the vibration-damping unit can be reduced, while the thickness of the plate-like member can be increased to increase the thickness of the weight portion in order to obtain a vibration-damping effect, and the thickness of the plate-like member can be appropriately set depending on the environment of the application.

[0027] The vibration-damping sheet 1 includes a base 2 and a plurality of vibration-damping units 3. In this embodiment, the base 2 and the vibration-damping units 3 have the same plate thickness, for example, about 0.8 to 1.0 mm. Note that the thickness value is an example, and can be set appropriately depending on the material of the plate-like member used, the purpose, the environment of the application, the frequency to be damped, etc. When the vibration-damping sheet is placed on a surface 80 of an object 8 to be damped, the base 2 comes into contact with the surface 80.

[0028] In the vibration-damping sheet 1 shown in FIG. 1, an X-axis and a Y-axis are set parallel to two orthogonal sides of the vibration-damping sheet 1 having a rectangular outer shape, and a Z-axis is set perpendicular to the X-axis and the Y-axis. As shown in FIG. 3, when the vibration-damping sheet 1 is placed on a flat surface, a virtual line 16 perpendicular to the flat surface passing through the center of gravity C of the weight section 31 is set. The virtual line 16 is parallel to the Z-axis. When the vibration-damping sheet 1 is placed on a horizontal plane, the extension direction of the virtual line 16 coincides with the direction of gravity. Note that, when the vibration-damping sheet 1 is placed on a curved surface, a normal line to the curved surface passing through the center of gravity of the weight section 31 corresponds to the virtual line 16. A virtual plane perpendicular to the virtual line 16 is set. In this specification, the "in-plane direction" refers to the in-plane direction in the virtual plane, and the "out-of-plane direction" refers to the direction parallel to the virtual line 16. In this specification, the "in-plane direction" is sometimes called the "horizontal direction" and the "out-of-plane direction" is sometimes called the "vertical direction". In this embodiment, the "in-plane direction" corresponds to the in-plane direction in the XY plane, and the "out-of-plane direction" corresponds to the Z-axis direction. Here, an example is given in which the surface of the vibration-damping object 8 on which the vibration-damping sheet 1 is arranged is flat.

[0029] In this specification, the "top" of the vibration damping unit 3 refers to the direction away from the object 8 to be damped when the vibration damping sheet 1 is placed on the object 8 to be damped, and the "bottom" refers to the direction closer to the object 8 to be damped. Also, the view of the vibration damping sheet 1 from above in its thickness direction (Z-axis direction) is referred to as a plan view.

[0030] The object 8 to be damped is a vibrating object. The object 8 to be damped may be a vibration source such as a device or an engine, or may be an object that vibrates due to vibration of a vibration source different from the object 8 to be damped, or may be an object that vibrates due to the propagation of sound from a sound source different from the object 8 to be damped. The vibration-damping sheet 1 is disposed on a surface 80 of the object 8 to be damped, thereby reducing the vibration of the object 8 to be damped.

[0031] In this embodiment, an example is given in which the surface 80 of the object to be damped 8 on which the vibration-damping sheet 1 is arranged is a flat surface, but the surface of the object to be damped may be a curved surface. The thickness a of the base 2 may be adjusted so that the base 2 in contact with the vibration-damping sheet 1 can deform along the curved surface of the object to be damped, or the base 2 may be formed, for example, in an elongated shape so that the vibration-damping sheet 1 can easily deform along the curved surface of the object to be damped. In addition, in this embodiment, an example is given in which the outer shape of the vibration-damping sheet 1 is rectangular, but the outer shape of the vibration-damping sheet 1 is not limited to a rectangle and may be set appropriately depending on the surface shape of the object to be damped 8 to which the vibration-damping sheet 1 is attached, etc.

[0032] As shown in FIG. 1 and FIG. 2, the base 2 has an opening edge 60 that forms a plurality of rectangular openings 6 that are partitioned. FIG. 3(B) is a partial plan view of the vibration-damping sheet 1 before bending, and is a diagram illustrating the area that is removed from the original unprocessed plate-like member by etching or cutting (more specifically, cut-out). Here, an example in which etching is adopted will be described. In the plan view of FIG. 3(B), the area filled with fine dots is the area that remains after etching, and the white area is the removal area 61 that is removed by etching. The area that remains after etching is the vibration-damping unit 3 and the base 2. One opening 6 has a rectangular shape that includes an area that corresponds to the shape of four vibration-damping units 3 in a plan view. In detail, the opening 6 includes an area that corresponds to the vibration-damping unit 3 and a removal area 61. As shown in FIG. 3(B), the periphery of the vibration-damping unit 3 is removed by etching, and the removal area 61 is located so as to substantially surround the vibration-damping unit 3.

[0033] The vibration-damping unit 3 has a weight 31 and a support 32. The weight 31 is located outside the opening 6. One end 321 of the support 32 is connected to the weight 31, and the other end 322 is connected to the opening edge 60 of the base 2. The support 32 allows the weight 31 to vibrate. The support 32 of the vibration-damping unit 3 is elongated, and the vibration-damping unit 3 can vibrate (swing) with the connection 4 between the base 2 and the root of the support 32 as a fulcrum. As shown in FIG. 3(B), in the vibration-damping sheet 1 before bending, a gap is formed between the base 2 having the opening edge 60 that forms the opening 6 and the vibration-damping unit 3, and between adjacent vibration-damping units 3, which is a removal region 61. In other words, the vibration-damping unit 3 is located apart from the base 2, except for the connection 4 that connects to the opening edge 60 of the base 2.

[0034] The above-mentioned "weight portion 31 is located outside opening 6" means that when vibration-damping sheet 1 is placed on a horizontal plane, weight portion 31 is not located within opening 6, but is located away from the opening surface of opening 6.

[0035] As shown in Figures 1 and 3(A), each vibration-damping unit 3 of the vibration-damping sheet 1 in Figure 2 is folded starting from the connection portion 4 and raised at an angle on the upper side (the first surface 20a side in the example shown in Figure 1), thereby obtaining a vibration-damping sheet 1 having a vibration-damping unit 3 that extends diagonally upward from the opening edge 60 and has a shape in which the weight portion 31 is positioned outside the opening 6.

[0036] In this embodiment, an example is given in which the vibration-damping unit 3 extends obliquely upward when the vibration-damping sheet 1 is placed on the object 8 to be damped, but the arrangement is not limited to this. For example, the surface 80 of the object 8 to be damped may have a recess, and the space within the recess may be used as the vibration space of the vibration-damping unit 3. An example of an arrangement on the surface 80 of the object 8 to be damped that has a recess will be described later.

[0037] The base 2 and the vibration damping unit 3 will be described in detail below.

[0038] (base)

[0039] 1 to 3, the base 2 is a portion of an original, unprocessed plate-like member 20, excluding areas corresponding to the vibration-damping units 3 and a removal area 61. The second surface 20b of the base 2 is a portion that comes into contact with the surface 80 of an object to be damped 8 when the vibration-damping sheet 1 is placed on the surface 80, and the vibration-damping sheet 1 can be fixedly placed on the object to be damped 8 by being affixed and fixed to the surface 80 with an adhesive or the like.

[0040] As shown in FIG. 1 to FIG. 3, the base 2 has a picture frame-shaped outer peripheral frame 21 and an inner frame 22 that defines a plurality of openings 6 within the outer peripheral frame 21. The inner frame 22 includes a plurality of vertical frames 22y as first frames and a plurality of horizontal frames 22x as second frames. The vertical frames 22y extend parallel to the Y-axis direction and are arranged at equal intervals in the X-axis direction (three in the example shown in FIG. 2). The horizontal frames 22x extend parallel to the X-axis direction and are arranged at equal intervals in the Y-axis direction (three in the example shown in FIG. 2). The vertical frames 22y and the horizontal frames 22x intersect with each other. In this embodiment, an example is given in which the first frame (vertical frame 22y) and the second frame (horizontal frame 22x) intersect at an angle of 90°, but this is not limited thereto and may be configured to intersect at another angle, as long as a vibration damping unit can be formed within the opening defined by the first frame and the second frame. The vibration-damping sheet 1 has 16 openings 6 defined by an outer peripheral frame 21, three vertical frames 22y, and three horizontal frames 22x. In this specification, when there is no need to distinguish between the outer peripheral frame 21 and the inner frame 22 (vertical frames 22y, horizontal frames 22x), they are referred to as the "base 2."

[0041] As shown in FIG. 1, FIG. 3, and FIG. 4, the vibration-damping sheet 1 is connected to the opening edge 60 of the base 2 that forms each opening 6, and includes a vibration-damping unit 3 that protrudes from the opening edge 60. When the vibration-damping sheet 1 is placed on the surface 80 of the vibration-damping object 8, the vibration-damping unit 3 can be arranged so as to extend obliquely upward with respect to the surface 80 and to be spaced apart from the surface 80. In the vibration-damping sheet 1, four vibration-damping units 3 are provided for each opening 6. In detail, one vibration-damping unit 3 is connected to each of the four sides of the opening edge 60 of one rectangular opening 6, and the support parts 32 of each vibration-damping unit 3 extend in different directions from each other. An assembly consisting of the base 2 that forms one opening 6 and the four vibration-damping units 3 connected to the base 2 is called a cell 10. The vibration-damping sheet 1 has 16 cells 10. There are cells 10 in which the base forming one opening 6 is the outer peripheral frame 21 and the vertical frame 22y and / or the horizontal frame 22x, and there are cells 10 in which the base forming one opening 6 is the vertical frame 22y and the horizontal frame 22x. Fig. 3(A) is a perspective view of a cell 10 in which the base forming one opening 6 is the vertical frame 22y and the horizontal frame 22x. As shown in Fig. 3(A), in one cell 10, one vibration control unit 3 is connected to each of the two vertical frames 22y and the two horizontal frames 22x.

[0042] By providing the inner frame 22 (vertical frame 22y and horizontal frame 22x), the number of vibration-damping units 3 arranged in the X-axis direction and / or Y-axis direction in one vibration-damping sheet can be increased, making it possible to arrange multiple vibration-damping units 3 at high density, thereby improving vibration-damping performance. Note that it is also possible to provide a vibration-damping sheet with only one cell 10 having a base 2 consisting of only the outer peripheral frame 21, without providing the vertical frame 22y and horizontal frame 22x.

[0043] Refer to FIG. 2. The width d of the outer peripheral frame 21 is typically wider than the width e of the inner frame 22 (the vertical frame 22y and the horizontal frame 22x). This allows the vibration-damping sheet 1 to be stably fixed to the vibration-damping target 8. The width d of the outer peripheral frame 21 and the width e of the vertical frame 22y and the horizontal frame 22x can be appropriately set according to the size of the entire vibration-damping sheet 1, etc. In this embodiment, the width d of the outer peripheral frame 21 is, for example, 10 mm, and the width e of the vertical frame 22y and the horizontal frame 22x is, for example, 1 to 2 mm. However, the width d of the outer peripheral frame 21 is preferably a certain width, and is preferably 5 mm or more, from the viewpoint of making the vibration-damping sheet 1 difficult to peel off from the surface 80 of the vibration-damping target 8 and of easiness in attaching the vibration-damping sheet 1 to the surface 80. The width e of the vertical frame 22y and the horizontal frame 22x is preferably 1 mm or more from the viewpoint of making the vibration-damping sheet 1 difficult to peel off from the surface 80 of the vibration-damping target 8.

[0044] In the present embodiment, the shape of the opening 6 is rectangular, but is not limited thereto. For example, the shape of the opening 6 may be a polygon having three or more sides, or a circle including an ellipse and a perfect circle.

[0045] (Vibration control unit)

[0046] As shown in Fig. 1, the vibration-damping sheet 1 has 64 vibration-damping units 3. All of the vibration-damping units 3 have the same shape and size. The vibration-damping units 3 are capable of vibrating in the in-plane direction and the out-of-plane direction.

[0047] In this embodiment, the vibration-damping sheet 1 is made of a single plate-like member, and by adjusting the planar shapes and dimensions of the support portion 32 and the weight portion 31, the spring constant and the mass of the weight portion can be adjusted, and the natural frequency of the vibration-damping unit 3 can be easily optimized. This increases the degree of freedom in design, and allows the vibration-damping sheet 1 to be easily controlled to achieve the vibration frequency to be damped.

[0048] As shown in Figs. 1 to 4, the vibration-damping sheet 1 is composed of one plate-like member, and the vibration-damping unit 3 has a flat shape. In the present embodiment, an example has been given in which the thickness of the weight portion 31 and the thickness of the support portion 32 are made equal to each other, but they may be different. For example, the thickness of the weight portion may be in the range of approximately 0.5 to 10 times the thickness of the support portion, and the vibration-damping unit may have an overall flat shape. In this way, by adjusting the thicknesses of the weight portion 31 and the support portion 32 in addition to adjusting the planar shapes and dimensions of the weight portion 31 and the support portion 32, it becomes easier to optimize the natural frequency of the vibration-damping unit 3, and it becomes easier to control the vibration frequency to be damped.

[0049] The vibration-damping unit 3 is supported by the base 2. Since the weight 31 is located outside the opening 6, when the vibration-damping sheet 1 is placed on the object 8 to be damped, the vibration-damping unit 3 is located away from the surface 80 of the object 8 to be damped, and the vibrating weight 31 is unlikely to come into contact with the base 2 and the object 8 to be damped. As a result, the vibration-damping sheet 1 is placed on the object 8 to be damped in a state in which a space (vibration space) in which the vibration-damping unit 3 can move is secured so that the vibration of the vibration-damping unit 3 is not hindered. Note that the thickness of the base 2 may be increased from the viewpoint of securing the vibration space between the surface 80 of the object 8 to be damped and the vibration-damping unit 3, which will be described in the fifth embodiment described later.

[0050] The vibration-damping unit 3 is configured to be easily vibrated by vibrations transmitted from the object 8 to be damped. The overall shape of the vibration-damping unit 3 is configured by providing a weight 31 at the tip of a long, thin rod-shaped support 32. The support 32 supports the weight 31. The vibration-damping unit 3 constitutes a vibrating body that can vibrate, and the weight of the weight 31 causes the vibration-damping unit 3 to vibrate in multiple directions (in other words, swing). The frequency at which vibration can be damped depends on the natural frequency of the control unit. The natural frequency of the vibration-damping unit 3 is adjusted so that the weight 31 vibrates at approximately the same period as the vibration to be suppressed, so that the natural frequency of the vibration-damping unit 3 is approximately equal to the period of the vibration of the object 8 to be damped (the vibration to be suppressed). The weight 31 vibrates in response to the vibration of the object 8 to be damped, absorbing the vibration of the object to be damped and reducing the vibration of the object 8 to be damped. In this way, the vibration-damping unit 3 functions as a dynamic vibration absorber that suppresses the resonance phenomenon around the vibration frequency of the object 8 to be damped. When the vibration mode of the vibration damping unit is in the out-of-plane direction, it has a vibration damping effect against out-of-plane vibration, whereas when the vibration mode of the vibration damping unit is in the in-plane direction, it has a vibration damping effect against in-plane vibration.

[0051] The natural frequency of the vibration damping unit is adjusted by the mass and spring constant of the weight. In this embodiment, the natural frequency of the vibration damping unit 3 can be set arbitrarily by changing the material of the weight 31 and the support 32, i.e., the properties (Young's modulus, density) of the material of the plate-like member, and the size of the weight 31 and the support 32 (planar shape and dimensions, thickness of the weight, planar shape and dimensions, thickness of the support, etc.). For example, the natural frequency can be increased by reducing the mass of the weight 31, and the natural frequency can be decreased by increasing the mass. Also, for example, the natural frequency can be decreased by increasing the length of the support.

[0052] In the vibration damping unit 3 of this embodiment, since the support portion 32 has an elongated shape, the spring constant of the support portion 32 can be easily changed by adjusting the dimensions of the support portion 32 without changing the material constituting the support portion 32 to change the physical properties, in other words, even if the same material as the base portion 2 and the weight portion 31 is used. This allows the natural frequency of the vibration damping unit 3 to be tuned over a wide range, and the vibration damping unit 3 can be easily designed according to the vibration frequency to be reduced. In this way, since the support portion 32 provided between the weight portion 31 and the base portion 2 of the vibration damping sheet 1 of this embodiment has a rod-like elongated shape, the natural frequency of the vibration damping unit 3 can be tuned over a wide range, and the design freedom is high.

[0053] As shown in FIG. 3(A), the connection part 4, which is the part where the other end 322 of the support part 32 is connected to the base part 2, becomes the base of the vibration-damping unit 3 with respect to the base part 2. The vibration-damping unit 3 vibrates with the connection part 4 as a fulcrum when vibration from the vibration-damping target 8 is transmitted. The vibration-damping unit 3 has the elongated support part 32, which makes it easy to swing in both the in-plane direction and the out-of-plane direction, and it is possible to reduce both the in-plane vibration and the out-of-plane vibration of the vibration-damping target 8. Furthermore, since the weight part 31 is located outside the opening 6, it is configured so that it is unlikely to be interfered with by the base part 2 in the in-plane vibration. For this reason, it is easy to design the weight part 31 so that the planar shape of the weight part 31 is enlarged and the mass of the weight part 31 is increased, and the natural frequency of the vibration-damping unit 3 can be tuned in a wide range, and the vibration-damping sheet 1 has a high degree of design freedom. The vibration-damping sheet 1 is also made of one plate-like member 20, and the area of ​​the plate-like member 20 corresponding to the opening 6 is used as the weight part 31. From the viewpoint of increasing the planar shape of the weight portion 31 and arranging the vibration damping units 3 at a higher density, it is preferable to make the weight portion 31 rectangular with respect to the rectangular opening 6 in a plan view, as in this embodiment. In this embodiment, in the vibration damping sheet 1 before bending shown in Fig. 2, the four sides of the rectangular weight portion 31 are approximately parallel to the four sides of the opening edge 60 that forms the rectangular opening 6 in a plan view.

[0054] Refer to FIG. 3(A) and FIG. 4. The inclination angle θ of the vibration-damping unit 3 with respect to the surface 80 is, for example, 20°. The inclination angle θ is set so that the vibration-damping unit 3 does not come into contact with the vibration-damping target 8 when it vibrates, and is preferably set to less than 90° from the viewpoint of facilitating large vibration. When the angle of the vibration-damping unit 3 to be raised is shallow (the value of the inclination angle θ is small, generally, for example, less than 45°), the structure is likely to vibrate in the out-of-plane direction. On the other hand, when the angle of the vibration-damping unit 3 is deep (the value of the inclination angle θ is large, generally, 45° or more and less than 90°), the structure is likely to vibrate in the in-plane direction. Therefore, the inclination angle θ can be adjusted according to the direction in which the vibration-damping effect is desired to be enhanced (the desired vibration mode), and the adjustment range of the vibration-damping direction can be expanded. In addition, the inclination angle θ can be arbitrarily adjusted according to the environment in which the vibration-damping sheet 1 is installed, and the vibration-damping sheet 1 can be installed in a narrow space, making it a highly versatile vibration-damping sheet.

[0055] Moreover, by setting the inclination angle θ to less than 90°, when the vibration-damping sheet 1 is viewed in a plane, the vibration-damping unit 3 is located within the frame (base) of the cell 10 to which the vibration-damping unit 3 belongs, that is, within the opening 6 formed by the opening edge 60 to which the vibration-damping unit 3 is connected. In other words, when the vibration-damping sheet 1 is placed on the surface 80 of the vibration-damping target 8, the vibration-damping unit 3 fits within the frame to which the vibration-damping unit 3 is connected in a projection of the vibration-damping unit 3 projected onto the surface 80. With this configuration, it is easy to design the vibration-damping units of adjacent cells 10 so that they do not collide with each other. For example, as long as the inclination angle θ of the vibration-damping unit 3 is set so that four vibration-damping units 3 belonging to one cell 10 vibrate within the range of the area corresponding to the opening 6 in a plane view, the vibration-damping units 3 belonging to adjacent cells 10 can be designed to vibrate so as not to collide with each other. In particular, when the vibration-damping units 3 are densely arranged on one vibration-damping sheet 1, it is effective to design it in this way, and a vibration-damping sheet 1 with stable vibration-damping characteristics can be stably manufactured.

[0056] Furthermore, in the vibration-damping sheet 1, the multiple vibration-damping units 3 may or may not be arranged at equal intervals in each of the X-axis and Y-axis directions. At least, the multiple vibration-damping units 3 should be arranged so that they do not interfere with each other's vibrations (shaking) when the vibration-damping sheet 1 is placed on the object 8 to be damped. This makes it possible to prevent the vibration-damping units 3 from colliding with each other, resulting in a vibration-damping sheet 1 with stable vibration-damping characteristics.

[0057] In the vibration-damping sheet 1, in one cell 10, the support parts 32 of the four vibration-damping units 3 are connected to different base parts 2 corresponding to the four sides of the rectangular opening 6. Here, as shown in FIG. 3, the four vibration-damping units 3 belonging to one cell 10 are distinguished as a first vibration-damping unit 301, a second vibration-damping unit 302, a third vibration-damping unit 303, and a fourth vibration-damping unit 304. When there is no need to distinguish them, they are called vibration-damping units 3. The support parts 32 of the first to fourth vibration-damping units 301 to 304 each extend in a direction perpendicular to the extending direction of the base part to which they are connected, and while maintaining this perpendicular direction, they rise from the connecting part 4 as a rising starting point and are inclined obliquely with respect to the surface 80. Therefore, in one cell 10, the extending directions of the support parts 32 of the first vibration-damping unit 301, the second vibration-damping unit 302, the third vibration-damping unit 303, and the fourth vibration-damping unit 304 are different from each other. With this configuration, vibration-damping units 3 that are particularly prone to shaking in the Y-axis direction in in-plane directions (horizontal directions) are mixed with vibration-damping units 3 that are particularly prone to shaking in the X-axis direction, resulting in a vibration-damping sheet 1 that is effective in reducing vibrations in multiple different directions in the in-plane directions of the object 8 to be damped.

[0058] In this embodiment, a single plate-shaped member is etched to form the base 2 and the vibration-damping unit 3, and then bent to raise the vibration-damping unit 3 at an angle. In other words, the base 2 and the vibration-damping unit 3 that are connected to each other are made of the same material and are connected. In this embodiment, the base 2, the weight 31, and the support 32 each have the same thickness. The thicknesses of the base 2, the weight 31, and the support 32 do not necessarily have to be the same. An example of a vibration-damping unit in which the weight and the support have different thicknesses will be described in the second embodiment described later, and an example of a vibration-damping sheet in which the vibration-damping unit 3 and the base 2 have different thicknesses will be described in the fifth embodiment described later.

[0059] 3(A), weight portion 31 has a planar rectangular plate shape, but the planar shape of weight portion 31 is not limited to a rectangle and may be a circle, a polygon, etc. When there is a constraint on the area of ​​the portion of the vibration-damping object on which the vibration-damping sheet is to be placed, that is, when there is a constraint on the size of the applicable vibration-damping sheet in the X and Y directions, it is preferable to efficiently and densely arrange the vibration-damping units within the surface from the viewpoint of enhancing the vibration-damping effect, and the planar shape of the weight portion is preferably a rectangle or a polygon as in this embodiment.

[0060] 3(A) and 4, the support portion 32 of the vibration-damping unit 3 protrudes from the bottom surface of the rectangular weight portion 31, extends away from the weight portion 31, including an in-plane component of the imaginary plane (an in-plane component of the XY plane, an in-plane component of the surface 80) and a directional component parallel to the imaginary straight line 16 (an out-of-plane component, a Z-axis component), and lands on the opening edge 60 of the base 2. In the vibration-damping sheet 1, vibrations from the object 8 to be damped are transmitted to displace the support portion 32, and the weight of the weight portion 31 causes the vibration-damping unit 3 to vibrate.

[0061] 3(A), the cross-sectional shape and size of support part 32 of vibration damping unit 3 do not change from one end 321 to the other end 322, and the thickness is uniform along the extension direction of support part 32. The thickness of support part 32 may change along the extension direction, and support part 32 is preferably formed elongated so as not to interfere with the vibration of weight part 31 in multiple directions.

[0062] Incidentally, the support part being "long and thin" typically refers to the case where, when an imaginary line is drawn through the center of a cross section of the support part, the length of the longest line segment connecting the two intersection points where the imaginary line intersects with the contour line of the cross section is s, and the length of the support part in the extension direction (the length from one end to the other end) is t, the value of t / s is 2 or greater.

[0063] When there is a recess in the surface 80 to which the vibration-damping object 8 is attached, the recess may be utilized to make the gap between the vibration-damping unit 3 and the attachment surface a vibration space for the vibration-damping unit 3. An example in which there is a recess 81 in the surface 80 to which the vibration-damping object 8 is attached and the recess 81 is utilized as a vibration space for the vibration-damping unit 3 will be described with reference to Figs. 13(A) to (C). The inner surface of the recess that forms the recess 81 is also included in the surface 80. The positions of the vibration-damping unit in each of Figs. 13(A) to (C) show the positions when the vibration-damping unit is not vibrating. The same applies to Figs. 12(A) and (B) described later.

[0064] 13(A), the vibration-damping sheet 1 of the first embodiment may be arranged so that the vibration-damping unit 3 extends obliquely upward (in the direction opposite to the direction in which the recess 18 is recessed). With such a configuration, the vibration-damping unit 3 can vibrate the space including the space inside the recess 81 as the vibration space. With such a configuration, even if the gap 82 between the object 8 to be damped on which the vibration-damping sheet 1 is arranged and the object 9 is narrow, a sufficient vibration space can be secured and the rise angle of the vibration-damping unit 3 can be adjusted to be small according to the size of the gap 82.

[0065] In this way, since the vibration-damping sheet 1 has the openings 6, the vibration-damping units 3 can vibrate so as to protrude in the thickness direction Z from each of the first surface 20a and the second surface 20b of the vibration-damping sheet 1. If the depth of the recesses 81 is not sufficient, the thickness of the base may be increased to ensure a sufficient vibration space.

[0066] 13B, the vibration-damping sheet 1 of the first embodiment may be arranged so that the vibration-damping unit 3 extends obliquely downward. In other words, the vibration-damping sheet 1 may be arranged so that the vibration-damping unit 3 is located in the recess 18. With such a configuration, the vibration-damping unit 3 can vibrate the space in the recess 81, and a vibration space can be secured. In addition, by adjusting the rising direction and rising angle of the vibration-damping sheet 1 so that the vibration-damping unit 3 vibrates only in the recess 18, the vibration-damping effect of the vibration-damping sheet 1 can be obtained without being influenced by the size of the gap 82 between the object 8 to be damped and the object 9. For example, even if the gap 82 is zero, the vibration-damping effect of the vibration-damping sheet 1 can be obtained by utilizing the shape of the object 8 to be damped.

[0067] As shown in FIG. 13C, a flat vibration-damping sheet 1 before bending may be used, the vibration-damping sheet 1 may be arranged so that the vibration-damping unit 3 is located corresponding to the recess 81, and the vibration-damping unit 3 may be vibrated in a space including the space in the recess 81. In this case, the vibration-damping unit 3 is located in the opening 6 in a non-vibrating state. With this configuration, when the vibration-damping sheet 1 is arranged in the gap 82 between the object 8 to be damped and the object 9, even if the gap 82 is narrow, the shape of the object 8 to be damped can be utilized to ensure a space for the vibration-damping unit 3 to vibrate. When the vibration-damping sheet 1 is made flat in this way, bending is not required, and there is no need to increase the thickness of the base to ensure the vibration space, as described above.

[0068] Here, as shown in Fig. 3(B), gaps are formed between the base 2 and the vibration-damping unit 3 and between adjacent vibration-damping units 3, and the base 2 and the vibration-damping unit 3 are separated except at the connection portion 4, and adjacent vibration-damping units 3 are also separated. When arranging the vibration-damping sheet 1 in a flat state before bending as shown in Fig. 13(C), by ensuring the above-mentioned gap (corresponding to the removed area 61), the vibration-damping unit can vibrate not only in the out-of-plane direction but also in the in-plane direction without being interfered with by the base or other vibration-damping units. When using the vibration-damping sheet 1 in a flat state like this, it is preferable to ensure a sufficient removed area 61 around the vibration-damping unit 3, which constitutes a part of the opening 6.

[0069] In the flat vibration-damping sheet before bending shown in Figure 13(C), the vibration-damping unit is located inside the opening, whereas in the vibration-damping sheet 1 after bending shown in Figures 13(A) and (B), the vibration-damping unit is located outside the opening.

[0070] In a vibration-damping sheet in which the weight is located within the opening, the dimensions of the weight are limited because the in-plane vibration of the weight is likely to be interfered with by the base as described above. In contrast, in a vibration-damping sheet in which the weight is located outside the opening, the weight is located outside the opening, so that the in-plane vibration of the weight is less likely to be interfered with by the base, and therefore the planar shape of the weight 31 can be designed to be larger, allowing for greater design freedom than a vibration-damping sheet in which the weight is located inside the opening.

[0071] Also, for example, when forming a vibration-damping unit by cutting, it may be difficult to provide a sufficient gap between the weight and the base, as in the case of etching. In a vibration-damping sheet in which a weight is located within an opening and there is no sufficient gap between the weight and the base, for example, when subjected to vibration in an out-of-plane direction (vertical direction), the weight does not necessarily vibrate in an out-of-plane direction relative to the base due to the misalignment of the center of gravity of the support part and the weight, so there is a risk that the vibrating weight will come into contact with the base, resulting in a decrease in the vibration-damping function or damage to the structure. In contrast, in a vibration-damping sheet in which a weight is located outside an opening, even if there is no sufficient gap between the weight and the base in the vibration-damping sheet before bending, the vibrating weight is unlikely to come into contact with the base in the vibration-damping sheet after bending, and the risk of a decrease in the vibration-damping function or damage due to contact can be avoided.

[0072] In this way, from the viewpoint of freedom of design and from the viewpoint of avoiding the risk of deterioration of the vibration damping function or damage, it is preferable to configure the weight portion to be located outside the opening.

[0073] As described above, the vibration-damping sheet 1 of this embodiment can be arranged in a variety of configurations according to the shape of the object 8 to be vibration-damped, making it highly versatile.

[0074] In this embodiment, the vibration-damping sheet 1 is mainly described, which is bent to make the vibration-damping unit 3 stand up at an angle. However, the vibration-damping sheet 1 before bending may be brought to a work site where the vibration-damping object 8 is located, and a worker may stand up the vibration-damping unit at the work site. In this case, since the vibration-damping sheet before bending is in a flat state, the thickness of the laminate does not become too thick even when the sheets are stacked, and the transportability and storage efficiency can be improved. In addition, the inclination angle of the vibration-damping unit 3 can be adjusted as desired depending on the environment in which the vibration-damping sheet is placed, such as a narrow space for placing the vibration-damping sheet or the surface condition of the vibration-damping object 8 (for example, the presence of a recess as described above). In addition, even in the case of a vibration-damping sheet having a vibration-damping unit that is in a state of standing up at an angle in advance, the worker may fine-tune the inclination angle of the vibration-damping unit 3 depending on the environment in which the vibration-damping sheet is placed. From the viewpoint of allowing an operator to adjust the inclination angle of the vibration-damping unit, it is preferable to use a material for the vibration-damping sheet that allows the connection portion 4 to be folded relatively easily, that is likely to maintain the folded shape, and that enables the vibration-damping unit to vibrate; for example, it is preferable to use a metal.

[0075] <Manufacturing method>

[0076] Fig. 5 shows a manufacturing flow of the vibration-damping sheet 1. Fig. 6 shows a manufacturing process diagram of the vibration-damping sheet 1, which is explained using a schematic cross section of a portion corresponding to line IV-IV. The vibration-damping sheet 1 can be manufactured through an etching process and a bending process. Hereinafter, the manufacturing method of the vibration-damping sheet 1 will be explained according to the manufacturing flow of Fig. 5 and with reference to the manufacturing process diagram of Fig. 6.

[0077] A plate-shaped member (metal flat plate) 20 having an unprocessed first surface 20a and a second surface 20b is prepared, and as shown in FIG. 6(A), both surfaces (first surface 20a and second surface 20b) of the plate-shaped member 20 are exposed and developed through a photomask to form a photoresist 5 having a desired pattern shape. The photoresist 5 is formed on both surfaces of the region excluding the above-mentioned removal region 61. Next, as shown in FIG. 6(B), the portion of the plate-shaped member 20 that is not covered by the photoresist 5 is etched and removed using a known etching solution such as hydrofluoric acid (HF) depending on the material of the plate-shaped member to be etched. Then, as shown in FIG. 6(C), the photoresist 5 is removed to obtain the plate-shaped member 20 before bending (ST1). By etching the plate-shaped member in ST1, a base 2 having an opening edge 60 that forms an opening 6 and a vibration damping unit 3 are formed. The vibration damping unit 3 has a weight portion 31 and a support portion 32. The support portion 32 has one end connected to the weight portion 31 and the other end connected to the opening edge 60 .

[0078] Next, as shown in Fig. 6(D), the plate-like member 20 after etching is subjected to bending (ST2). In this bending, the vibration damping unit 3 is bent at a connecting portion 4, which is the base portion of the vibration damping unit 3 attached to the base portion 2, as a rising starting point, so that the vibration damping unit 3 rises at an angle (for example, an inclination angle of 20°). In this way, the vibration damping sheet 1 shown in Fig. 1 is obtained.

[0079] In this manner, in the manufacturing method of this embodiment, it is possible to easily obtain a vibration-damping sheet 1 in which a plurality of vibration-damping units 3 and a base 2 that supports the vibration-damping units 3 and is arranged in contact with a surface 80 of an object to be damped 8 are integrated from one plate-like member 20. As in the vibration-damping sheet 1 shown in FIG. 1, by positioning the weights 31 outside the openings 6, when the vibration-damping sheet 1 is arranged on the surface 80 of the object to be damped 8, each of the vibration-damping units 3 is positioned away from the surface 80 of the object to be damped 8 as shown in FIG. 4, and the vibrating weights 31 are not interfered with by the base 2 and the object to be damped 8, and the vibration-damping units 3 can vibrate in the out-of-plane direction and in-plane direction. The vibration-damping units 3 absorb the vibration energy of the object to be damped 8, thereby damping the vibration of the object to be damped.

[0080] In this embodiment, an example of using an etching process to manufacture the vibration-damping sheet is given, but a cutting process may be used to form a base and a vibration-damping unit from one plate-like member as in the fourth embodiment described later. The vibration-damping sheet may also be manufactured by a 3D printer or injection molding, and the plate thicknesses of the base, weight, and support can be arbitrarily designed to widen the adjustment range of the natural frequency of the vibration-damping unit. From the viewpoint of easily manufacturing a vibration-damping sheet that is easy to control the vibration frequency to be damped, it is more preferable to form the base and the vibration-damping unit by etching or cutting one plate-like member. In this embodiment, an example of using so-called wet etching using an etching solution is given, but a dry etching process may also be used. From the viewpoint of ease of manufacture, it is preferable to use an etching process.

[0081] As described above, the vibration-damping sheet of this embodiment is configured so that the vibration-damping unit is vibrated by being composed of a weight and a support, and by positioning the weight outside the opening, the natural frequency of the vibration-damping unit can be easily tuned by adjusting the planar shape and dimensions of the weight and / or the support, and the vibration-damping sheet is easy to control the vibration frequency to be damped. Furthermore, the vibration-damping sheet of this embodiment has a high degree of design freedom because it is possible to control the vibration-damping unit to any frequency by adjusting the material properties (Young's modulus, density, etc.) of the plate-like member used and the shape of the vibration-damping unit (dimensions of the weight and / or dimensions of the support).

[0082] In addition, the vibration-damping sheet of this embodiment has openings in the areas of the plate-like member used to form the vibration-damping units, making it possible to reduce the weight compared to a configuration in which multiple vibration-damping units are arranged on a single plate-like member without an opening. Furthermore, since the vibration-damping sheet 1 has openings, various arrangements are possible as described above, making the vibration-damping sheet 1 highly versatile.

[0083] In addition, each vibration-damping unit provided in the vibration-damping sheet of this embodiment is generally flat and has a simple shape. This makes it easy to mold, and the vibration-damping unit can be easily manufactured by etching (or cutting) a single plate-like member, resulting in excellent productivity. Furthermore, by simplifying the shape of the vibration-damping unit, which is composed of a support part and a weight part, it becomes easy to change the design parameters of the vibration-damping unit in order to control the vibration-damping frequency.

[0084] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made. Other embodiments will be described below.

[0085] <Second embodiment>

[0086] Fig. 7(A) is a perspective view of a vibration-damping sheet 1A according to the second embodiment, and Fig. 7(B) is a partial perspective view of the vibration-damping sheet 1A. In the above embodiment, an example was given in which the weight 31 and the support 32 in the vibration-damping unit 3 are the same in thickness, but the weight 31A may be thicker than the support 32A, as in the vibration-damping unit 3A provided in the vibration-damping sheet 1A of this embodiment shown in Figs. 7(A) and (B). Note that in the example shown in Figs. 7(A) and (B), an example is given in which the base 2 (periphery frame 21, vertical frame 22y, horizontal frame 22x) and the support 32 are the same in thickness, but the support 33 may be thinner than the base 2.

[0087] 8 is a manufacturing process diagram of the vibration-damping sheet 1A. The vibration-damping sheet 1A can be manufactured through an etching process and bending processing, similar to the vibration-damping sheet 1. The manufacturing method of the vibration-damping sheet 1A will be described below with reference to the manufacturing process diagram of FIG.

[0088] First, a plate-shaped member (metal flat plate) 20A having a first surface 20a and a second surface 20b is prepared before processing, and then the plate-shaped member 20A is exposed through a photomask and developed to form a photoresist 5A having a desired pattern shape, as shown in Fig. 8(A). The photoresist 5A is formed on both sides (first surface 20a and second surface 20b) of the plate-shaped member 20A in the region that will become the weight portion 31A of the vibration damping unit 3A, and is formed on one side (second surface 20b) of the plate-shaped member 20A in the region that will become the support portion 32A and the base portion 2 (peripheral frame 21, vertical frame 22y, horizontal frame 22x), and is not formed on any surface in other regions.

[0089] Next, as shown in FIG. 8(B), the portion of the plate-shaped member 20 that is not covered by the photoresist 5A is etched and removed using an etching solution. At this time, the regions on both sides of the plate-shaped member 20 where the photoresist 5A is not formed are etched from both sides, so that the entire plate-shaped member is removed. The regions on only one side of the plate-shaped member 20 where the photoresist 5A is formed (the regions corresponding to the support portion 32A and the base portion 2) are etched only from one side, so that half the thickness of the original plate-shaped member is removed, and the remaining half of the thickness remains (half etching). The regions on both sides of the plate-shaped member 20 that will become the weight portion 31A where the photoresist 5A is formed are not etched, so that the thickness of the original plate-shaped member remains. Next, as shown in FIG. 8(C), the photoresist 5A is removed to obtain the plate-shaped member 20A before bending.

[0090] Next, as shown in Fig. 8(D), the plate-like member 20A after etching is bent. In this bending process, the vibration damping unit 3A is raised at an angle by bending it from the connection part 4, which is the base part of the vibration damping unit 3A attached to the base part 2, as the rising starting point. In this way, the vibration damping sheet 1A shown in Fig. 7(A) is obtained. The vibration damping unit 3A also functions as a dynamic vibration absorber, like the vibration damping unit 3 of the above-mentioned embodiment.

[0091] In this way, by changing the thickness of weight portion 31A and support portion 32A, the adjustment range of the natural frequency of the vibration damping unit can be increased.

[0092] In addition, as a method for making the thicknesses of the weight and the support in the vibration-damping unit different, a method other than the half-etching described in this embodiment may be used. For example, a vibration-damping sheet having a vibration-damping unit in which the weight and the support have the same thickness as shown in the first embodiment may be prepared, and a protective film or the like may be formed on one or both sides of only the weight of the vibration-damping sheet, thereby adjusting the thickness of the weight and therefore the mass.

[0093] Here, the vibration damping and sound insulation properties against vibration in the out-of-plane direction by the multiple vibration damping units 3A arranged in the arrangement form shown in FIG. 7 were evaluated. Specifically, as an evaluation object, a vibration damping sheet 100 in which multiple vibration damping units 3A are arranged on a substrate 101 having a thickness of 1 mm, a length of 100 mm, and a width of 100 mm, as shown in FIG. 15, was produced by molding with a 3D printer. In the vibration damping sheet 100, the substrate 101 and the vibration damping units 3A are integrally connected. The number and arrangement form of the vibration damping units 3A were the same as those of the vibration damping unit 3A shown in FIG. 7. In addition, as a comparison object, a flat plate having a length of 100 mm and a width of 100 mm, consisting of only a substrate without a vibration damping unit arranged thereon, was produced by molding with a 3D printer, and the thickness of the flat plate was adjusted so that the weight was equivalent to that of the evaluation object in FIG. 15. An acrylic resin was used as the material for all of the vibration damping sheets.

[0094] The evaluation of vibration-damping and sound insulation was performed using a wind tunnel testing device 50 shown in FIG. 14. The wind tunnel testing device 50 has a measuring section 54 at the center in the longitudinal direction, and a separately installed fan generates wind in a direction from one surface 53 to the other surface 52 so that the wind passes through the measuring section 54. A part 54a of the side wall of the measuring section 54 of the wind tunnel testing device 50 is replaced with a metal sheet 55 having a length of 180 mm, a width of 560 mm, and a thickness of 1.5 mm, and a state is created in which the turbulent boundary layer generated on the inner wall of the measuring section 54 during ventilation applies vibration in the out-of-plane direction to the metal sheet 55 simulating the object to be damped. In this state, the vibration-damping sheet 100 to be measured was placed at the center of the outer surface of the metal sheet 55 to be the object to be damped. Next, wind was generated in the measurement section 54 to vibrate the thin metal plate 55, and the vibration acceleration was measured using an acceleration sensor installed in the center of the thin metal plate 55, and the sound pressure level (SPL) was measured using a sound level meter equipped with a microphone installed near the thin metal plate 55. The vibration acceleration was also measured for a comparative flat plate using the same method. The results are shown in Figures 16 and 17. The procedure was as follows:

[0095] The graph shown in Fig. 16 shows vibration characteristics at the center of thin metal plate 55 measured using wind tunnel testing equipment 50, with the vertical axis of the graph showing vibration acceleration in the out-of-plane direction of thin metal plate 55 and the horizontal axis of the graph showing the frequency at which vibration occurs. In the graph shown in Fig. 16, the solid line shows the measurement results of the vibration-damping sheet of Fig. 15 which is the evaluation subject, and the dashed line shows the measurement results of the comparative flat plate. As shown in Fig. 16, it was confirmed that by providing multiple vibration-damping units 3A, the vibration-damping effect was higher than that of the comparative flat plate in which no vibration-damping units were arranged.

[0096] The graph shown in Fig. 17 shows acoustic characteristics measured using wind tunnel testing equipment 50, with the vertical axis of the graph showing sound pressure level (SPL) measured near the surface of thin metal plate 55, and the horizontal axis of the graph showing the frequency at which the sound pressure level is generated. The solid line in the graph shown in Fig. 17 shows the measurement results of the vibration-damping sheet of Fig. 15, which is the evaluation target. As shown in Fig. 17, the sound pressure level is low at around 238 Hz, confirming the sound insulation effect.

[0097] <Third embodiment>

[0098] Fig. 9 is a plan view of the vibration-damping sheet 1B of the third embodiment before bending, and Fig. 10 is a partial perspective view of the vibration-damping sheet 1B after bending. The vibration-damping sheet 1B of this embodiment can also be manufactured using etching and bending, like the vibration-damping sheet 1 of the first embodiment.

[0099] In the first embodiment, an example in which four vibration damping units are provided in one cell has been given, but one vibration damping unit 3B may be provided in the opening 6 of one cell 10B as shown in Fig. 9. One opening 6 includes an area corresponding to one vibration damping unit 3B in plan view and a removed area 61 that is removed by etching, and has an overall rectangular shape.

[0100] In addition, in the first embodiment, an example was given in which the weight portion is rectangular and the support portion is linear when the vibration-damping sheet before bending is viewed from above, but as in this embodiment, weight portion 31B may be circular in plan view, and support portion 32B may be an elongated curved shape that surrounds weight portion 31B along the outer periphery of weight portion 31B. By forming support portion 32B in a shape that surrounds weight portion 31B in this manner, the length of support portion 32B can be adjusted to be longer than the length of one side of opening 6 that is rectangular in plan view.

[0101] 10, the vibration damping unit 3B is raised at an angle by bending or the like, starting from the connection portion 4, and further processed so that the support portion 32B is spiral. The spiral shape of the support portion 32B allows the support portion 32B to have a spring function. The vibration damping unit 3B configured in this way can also function as a dynamic vibration absorber, similar to the vibration damping units of the above-mentioned embodiments.

[0102] Here, when trying to obtain a vibration damping effect against low frequencies, it is effective to increase the length of the support part of the vibration damping unit. In this embodiment, as shown in Fig. 9, support part 32B is continuously arranged around weight part 31B, and the length of support part 32B can be increased, so that the vibration damping effect against low frequencies can be improved.

[0103] <Fourth embodiment>

[0104] Fig. 11 is a plan view of the vibration-damping sheet 1C of the fourth embodiment before bending. In the above-mentioned embodiment, an example was given in which the vibration-damping unit and the base were formed by etching, but as shown in Fig. 11, the base 2C and the vibration-damping unit 3 may be formed by cutting (more specifically, cutting) the plate-shaped member 20. In this cutting process, a cut in the outer shape of the vibration-damping unit 3 is made in the plate-shaped member 20C while the portion of the plate-shaped member 20C that will become the connection portion 4 between the support portion 32 of the vibration-damping unit 3 and the base 2C remains connected. The cut can be made by, for example, mechanical processing, laser processing, or the like.

[0105] In the vibration-damping sheet 1C of this embodiment, only the portions corresponding to the vibration-damping units 3 formed by the cuts in the plate-like member 20C become the openings 6. The vibration-damping sheet 1 of the first embodiment can also be manufactured using a cutting process (more specifically, a cut-out process), and the vibration-damping sheet 1 may be manufactured by cutting out and removing the removal areas 61 by the cutting process.

[0106] <Fifth embodiment>

[0107] 12(A) is a partial cross-sectional view of a vibration-damping sheet 1D of the fifth embodiment placed on a surface 80 of an object 8 to be damped. Like the vibration-damping sheet 1 of the first embodiment, the vibration-damping sheet 1D can be manufactured by etching and bending a plate-shaped member 20D. The shape of the vibration-damping sheet 1D after etching but before bending when viewed from above is similar to that of the vibration-damping sheet 1 shown in FIG. 2. The vibration-damping sheet 1D differs from the vibration-damping sheet 1 of the first embodiment only in that the thickness of the base 2D is thicker than the thickness of the vibration-damping unit 3.

[0108] As shown in FIG. 12(A), the vibration-damping sheet 1D may be configured such that the thickness of the base 2D is thicker than the thickness of the vibration-damping unit 3. By configuring in this way, as shown in FIG. 12(A), the surface of the plate-like member 20D that has a step due to the difference in thickness is used as the attachment surface to place the vibration-damping sheet 1D on the surface of the vibration-damping target 8, and a gap equal to or larger than the gap 83 that is the difference in thickness between the base 2D and the vibration-damping unit 3 is generated between the vibration-damping unit 3 and the surface 80. The gap 83 may be utilized as part of the vibration space of the vibration-damping unit 3. The vibration-damping unit 3 can vibrate in the out-of-plane direction and in-plane direction with the connection portion 4 as a fulcrum, and the vibration-damping unit 3 can also vibrate the gap 83 and the space above the vibration-damping sheet 1D as a vibration space.

[0109] As shown in FIG. 12(B), the vibration-damping sheet 1D may be substantially flat before bending. As shown in FIG. 12(B), the vibration-damping sheet 1D is placed on the surface of the vibration-damping target 8 with the surface having the step due to the difference in thickness of the plate-like member 20D as the attachment surface, and a gap 83 that is substantially equivalent to the difference in thickness between the base 2D and the vibration-damping unit 3 is generated between the vibration-damping unit 3 and the surface 80. The gap 83 may be utilized as a part of the vibration space of the vibration-damping unit 3. The vibration-damping unit 3 can vibrate in the out-of-plane direction and in-plane direction with the connection part as a fulcrum, and the vibration-damping unit 3 can vibrate the gap 83 and the space above the vibration-damping sheet 1D as vibration spaces. With the vibration-damping sheet 1D configured in this way, it is possible to obtain a vibration-damping effect without bending or adjusting the inclination angle of the vibration-damping unit 3. However, as described above in the explanation using Figures 13(A) to (C), from the standpoint of design freedom and from the standpoint of avoiding risks such as a decrease in vibration-damping function or damage, it is preferable to use the vibration-damping sheet in which the weight portion is located outside the opening as shown in Figure 12(A) rather than the vibration-damping sheet in which the weight portion is located inside the opening as shown in Figure 12(B).

[0110] Sixth embodiment

[0111] In the above-mentioned first to third embodiments, an example was given in which the vibration-damping sheet 1 has 16 openings 6, but the number of openings is not limited to this, and the number of openings 6 provided in one vibration-damping sheet 1 may be one or more. When there is one opening, there is no inner frame, and the base is formed only by the outer peripheral frame. In addition, in the above-mentioned embodiments, an example was given in which the inner frame 22 includes the vertical frame 22y and the horizontal frame 22x, but a form in which either one is present at least once may also be used. For example, two vertical frames 22y may be provided in the outer peripheral frame 21, resulting in a vibration-damping sheet having a total of three openings 6, one vertical and three horizontal.

[0112] In the above-mentioned first and second embodiments, the number of vibration-damping units connected to the opening edge 60 forming one opening 6 is four, but the number of vibration-damping units is not limited to this and may be one or more. In the above-mentioned first and second embodiments, the four vibration-damping units belonging to one cell have the same shape, size, and tilt angle value, and all have the same natural vibration, but at least one of the shape, size, and tilt angle value may be different. For example, by varying the mass of the weight part and / or the size of the support part, the natural vibration frequency can be changed, and vibration-damping units with different natural vibration frequencies can be arranged in one vibration-damping sheet. In this way, the vibration-damping sheet is provided with multiple types of vibration-damping units with different natural vibration frequencies, so that vibrations over a wide range of frequencies can be damped. In addition, by varying the tilt angle value, it is possible to adjust whether the structure is easily vibrated in the in-plane direction or the out-of-plane direction. For example, by providing a vibration-damping sheet having a plurality of types of vibration-damping units with different inclination angles, such as a vibration-damping unit with an inclination angle value of 20° (a range of less than 45°) and a vibration-damping unit with an inclination angle value of 60° (a range of 45° or more and less than 90°), it is possible to obtain a vibration-damping sheet capable of effective vibration-damping in both the out-of-plane direction and the in-plane direction. In the above-mentioned embodiment, the extension directions of the four vibration-damping units 3 in one cell 10 are different from each other, but the extension directions of the plurality of vibration-damping units in one cell may all be the same. In the above-mentioned embodiment, all of the 16 cells 10 have the same shape and the same dimensions, but they may be different. For example, at least one of the number, extension direction, inclination angle, shape, dimensions, etc. of the vibration-damping units belonging to the cells may be different between two cells. In the above-mentioned embodiment, an example in which a vibration-damping unit is provided for all of the plurality of openings was given, but a configuration in which a vibration-damping unit is not provided for some of the openings may be used. It is sufficient that the vibration-damping sheet has one or more vibration-damping units connected to the opening edge forming at least one opening.

[0113] In the first to third embodiments, the opening 6 provided in the vibration-damping sheet is rectangular, but as described above, the opening is not limited to a rectangle, and may be circular, such as a perfect circle or an ellipse, or a polygonal shape other than a rectangle having three or more sides. For example, a plurality of vibration-damping units may be provided at equal or different intervals, protruding from the edge of a circular opening. In such a configuration, similarly to the first embodiment, a plurality of vibration-damping units extending in different directions from each other are provided, so that the vibration-damping effect against vibrations in a plurality of different directions in the in-plane direction of the vibration-damping object can be improved. From the viewpoint of arranging the vibration-damping units on the vibration-damping sheet at high density, the opening is preferably polygonal, such as a rectangle.

[0114] In the above embodiment, a plurality of cells having the same shape and dimensions are arranged in a matrix, and the vibration-damping sheet has vibration-damping units with support parts extending in different directions arranged in a regular manner, but the vibration-damping sheet may be configured to be arranged irregularly. All of the vibration-damping units provided on the vibration-damping sheet may include two vibration-damping units whose support parts extend in different directions. For example, a vibration-damping sheet having 16 cells each having one vibration-damping unit may be configured such that the extension direction of the support part of the vibration-damping unit belonging to one cell is different from the extension direction of the support parts of the vibration-damping units belonging to the other 15 cells.

[0115] In the above embodiment, the vibration-damping units are arranged at approximately equal intervals in the X-axis and Y-axis directions, but they may be arranged randomly. The vibration-damping units do not have to be arranged uniformly in the plane of the vibration-damping sheet, and there may be a mixture of areas where the vibration-damping units are densely arranged and areas where they are sparsely arranged. The arrangement of the vibration-damping units may be appropriately set according to the shape of the surface of the object to be damped.

[0116] <Application Examples>

[0117] A specific application example of the vibration-damping sheet will be described with reference to Fig. 18. Fig. 18 is a partial schematic cross-sectional view of an aircraft fuselage. As shown in Fig. 18, seats 41 are installed on floor panels 42 within the fuselage of an aircraft fuselage 40. The fuselage of the aircraft fuselage 40 has an outer panel 45, a plurality of frames 43, a plurality of stringers 44, an interior panel 46, an insulation blanket 47, and a vibration-damping sheet 1.

[0118] The fuselage of the aircraft 40 has a generally cylindrical shape. A plurality of frames 43 and a plurality of stringers 44 are provided inside the fuselage of the aircraft 40. The plurality of frames 43 are main structural members of the fuselage of the aircraft 40 and form the shape of the fuselage. The frames 43 extend in a circumferential direction around the central longitudinal axis of the fuselage. The plurality of frames 43 are arranged spaced apart from one another along the central longitudinal axis. The outer plate 45 is connected to the frames 43. The plurality of stringers 44 are arranged parallel to one another and extend parallel to the central longitudinal axis of the fuselage. The stringers 44 are connected to the inner surface of the outer plate 45 and the frames 43.

[0119] The frames 43 and stringers 44 are arranged in a lattice pattern. The vibration-damping sheet 1 and the insulation blanket 47 are provided in the space defined by the frames 43 and stringers 44. Furthermore, an interior panel 46 is attached to the inside of the spaces defined by the frames 43.

[0120] The insulation blanket 47 is made of a heat insulating material such as glass wool, and is designed to keep the cabin warm and absorb noise from outside.

[0121] The vibration-damping sheet 1 is attached to the inner surface of the outer plate 45. In an aircraft, an engine is typically arranged under the main wing or behind the fuselage, and the vibration caused by the operation of the engine propagates to vibrate the fuselage of the aircraft 40. Similarly, the sound generated by the engine acoustically vibrates the fuselage of the aircraft 40, causing the fuselage of the aircraft 40 to vibrate. The fuselage of the aircraft 40 also vibrates when it is subjected to aerodynamic vibration due to a turbulent boundary layer generated on the fuselage surface during flight. The turbulent boundary layer is a thin air layer that has a velocity distribution in the normal direction of the fuselage surface. In other words, the outer plate 45 corresponds to the object to be damped that is vibrated by the engine, which is the vibration source. The inner surface of the outer plate 45 corresponds to the surface of the object to be damped. The vibration-damping sheet 1 is arranged so that the base 2 and the inner surface of the outer plate 45 are in contact with each other via an adhesive. As a result, the multiple vibration-damping units 3 arranged on the vibration-damping sheet 1 are arranged so as to protrude toward the inside of the aircraft 40. Moreover, the vibration-damping sheet 1 is disposed inside the machine body 40 so that the vibrations of the weights 31 of the multiple vibration-damping units 3 do not interfere with each other and so that a space for the vibration-damping units 3 to vibrate is secured.

[0122] By providing the vibration-damping sheet 1 in this manner, vibration of the outer plate 45 caused by the engine, etc. can be damped. Furthermore, by damping the vibration, sound caused by the vibration of the outer plate 45 can be suppressed.

[0123] When the vibration-damping sheet 1 is applied to an aircraft, the second surface 2b side of the base 2 of the vibration-damping sheet 1 is arranged along the surface of the skin 45 of the fuselage. Even if the vibration-damping sheet 1 is not arranged so as to be parallel to the horizontal plane in this way, the vibration of the skin caused by the turbulent boundary layer, which is generally the main source of vibration to the fuselage skin, is in the normal direction of the skin (perpendicular to the skin surface), and therefore, for the purpose of damping this vibration, it is preferable that the height direction of the vibration-damping units 3 arranged on the vibration-damping sheet 1 is also parallel to the normal direction of the skin section in which the vibration-damping sheet is arranged.

[0124] Although various embodiments of the present invention have been described above, these embodiments are merely examples, and the present invention is not limited to the specific embodiments disclosed herein. In addition, it goes without saying that the scope of the present invention is not limited to these embodiments.

[0125] 1, 1A, 1B, 1C, 1D... Vibration-damping sheet 2, 2D…Base 3, 3A, 3B…Vibration control unit 4...Connection part (connection part between base and support part) 6…Aperture 8... Vibration control object 20...Plate-shaped member 21...Picture frame-shaped outer frame 22x...Horizontal frame (inner frame) 22y...Vertical frame (inner frame) 31, 31A, 31B... Weight part 32, 32A, 32B...Support part 60…Opening edge 80…Surface 301…First vibration control unit (vibration control unit) 302...Second vibration control unit (vibration control unit) 303…Third vibration control unit (vibration control unit) 304…4th vibration control unit (vibration control unit) 321...one end 322...other end

Claims

1. A vibration-damping sheet arranged on a surface of an object to be damped and composed of a single plate-like member, a base portion disposed in contact with a surface of the vibration damping object and having an opening edge that forms an opening; A weight portion located outside the opening; a support portion having one end connected to the weight portion and the other end connected to the opening edge, the support portion enabling the weight portion to vibrate; A vibration control unit having A vibration-damping sheet comprising:

2. The vibration-damping sheet according to claim 1, the base has one or more of the openings; One or more of the vibration damping units are connected to the opening edge that forms at least one of the openings. Vibration-damping sheet.

3. The vibration-damping sheet according to claim 2, the plurality of vibration damping units connected to the opening edge forming the at least one opening include a first vibration damping unit and a second vibration damping unit, the support portions of which extend in different directions from each other; Vibration-damping sheet.

4. The vibration-damping sheet according to claim 3, The opening edge forming the at least one opening has a polygonal shape having three or more sides, and the first vibration damping unit and the second vibration damping unit are connected to different sides. Vibration-damping sheet.

5. The vibration damping sheet according to any one of claims 1 to 4, The base portion includes a picture-frame-shaped outer peripheral frame and an inner frame that defines a plurality of the openings within the outer peripheral frame, For each of the openings, one or more of the vibration damping units are connected to the opening edge that forms the opening. Vibration-damping sheet.

6. The vibration-damping sheet according to claim 5, The plurality of vibration-damping units provided on the vibration-damping sheet include two vibration-damping units whose support portions extend in different directions from each other. Vibration-damping sheet.

7. The vibration damping sheet according to any one of claims 1 to 4, The vibration damping unit rises from a connection portion between the base portion and the support portion as a rising point and is positioned obliquely with respect to a surface of the vibration damping object. Vibration-damping sheet.

8. The vibration damping sheet according to any one of claims 1 to 4, the vibration damping unit is located in the opening formed by the opening edge to which the vibration damping unit is connected in a plan view; Vibration-damping sheet.

9. The vibration damping sheet according to any one of claims 1 to 4, The vibration-damping sheet is made of metal. Vibration-damping sheet.

10. The vibration damping sheet according to any one of claims 1 to 4, The thickness of the base is greater than that of the vibration damping unit. Vibration-damping sheet.

11. A plate-shaped member is etched or cut, a base having an opening edge that forms an opening; a vibration control unit having a weight portion and a support portion having one end connected to the weight portion and the other end connected to the opening edge to allow the weight portion to vibrate; Forming The vibration damping unit is raised by bending the connection portion between the base portion and the support portion as a rising point. A method for manufacturing a vibration-damping sheet.

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