Sound-absorbing material

Abstract

This silencing member comprises: a first space; a second space that is disposed adjacent to the first space; a passage that connects the first space and the second space; a first member that surrounds the bottom surfaces and / or side surfaces of the first space and the second space; and a film-shaped second member that covers the top surfaces of the first space and the second space.

Description

Technical Field

[0001] The present disclosure relates to a sound absorption member.

Background Art

[0002] Conventionally, a sound absorption member that outputs a cancellation wave, which is a sound wave having a phase opposite to that of an input sound wave, to cancel the input sound is known (see, for example, Patent Document 1).

[0003] [[ID=|17]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The sound absorption member of Patent Document 1 discloses a structure of a sound absorption member including a space having a pair of openings, a pair of transmitting and receiving membranes covering the respective openings, and a seesaw member connecting the pair of transmitting and receiving membranes. When one of the transmitting and receiving membranes of the sound absorption member of Patent Document 1 vibrates upon receiving noise, the seesaw member transmits the vibration to the other transmitting and receiving membrane. As a result, the other transmitting and receiving membrane transmits a cancellation wave having the same frequency and opposite phase to the vibration of the one transmitting and receiving membrane. As a result, the sound absorption member can cancel the sound wave of the noise by the cancellation wave.

[0005] On the other hand, the sound absorption member of Patent Document 1 needs to provide a space for arranging a seesaw member that connects the transmitting and receiving membranes. Therefore, it is necessary to select an installation location where sufficient space can be secured for installing the sound absorption member.

[0006] An object of the present disclosure is to provide a sound absorption member that can be installed in a narrower space or location.

Means for Solving the Problems

[0007] A sound-absorbing member according to one aspect of the present disclosure comprises a first space, a second space arranged adjacent to the first space, a passage connecting the first space and the second space, a first member surrounding the bottom and / or side surfaces of the first space and the second space, and a membrane-like second member covering the top surfaces of the first space and the second space.

[0008] This sound-absorbing member connects two adjacent spaces, a first and a second, with a passage. This allows the sound-absorbing member to quickly transmit vibrations input to one space to the other via the passage. As a result, the second member covering the other space can quickly generate a cancellation wave with the opposite phase to the input sound wave. This enables the sound-absorbing member to absorb input noise without requiring any connecting components to the second member. Consequently, the sound-absorbing member can be installed in smaller spaces or locations. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide sound-absorbing components that can be installed in narrower spaces or locations. [Brief explanation of the drawing]

[0010] [Figure 1] A perspective view showing a sound-absorbing member in the first embodiment of this disclosure. [Figure 2] A cross-sectional view showing section AA in Figure 1. [Figure 3] A top view showing a sound-absorbing member in the first embodiment of this disclosure. [Figure 4] A schematic diagram illustrating the noise reduction mechanism in the first embodiment of this disclosure. [Figure 5] An exploded perspective view showing a sound-absorbing member in a second embodiment of this disclosure. [Figure 6] A top view showing a sound-absorbing member in a second embodiment of this disclosure. [Figure 7] A cross-sectional view showing the BB section in Figure 6. [Modes for carrying out the invention]

[0011] <First Embodiment> The first embodiment of this disclosure will be described below with reference to the drawings. Each figure shows mutually orthogonal XYZ axes for determining direction.

[0012] In this embodiment, a sound-absorbing member that can be attached to the roof liner of an automobile or the like will be described as an example.

[0013] As shown in Figure 1, the sound-absorbing member 1 comprises a first space 2, a second space 4 arranged adjacent to the first space 2, a passage 6 connecting the first space 2 and the second space 4, a first member 8 surrounding the bottom and / or side surfaces of the first space 2 and the second space 4, and a second member 10 covering the top surfaces of the first space 2 and the second space 4.

[0014] As shown in Figure 2, the first space 2 is a hollow space surrounded by a top surface 21, a bottom surface 22 opposite the top surface 21, and a side surface 23. In this embodiment, both the top surface 21 and the bottom surface 22 are circular with radius R1 (see Figure 3). That is, the first space 2 is cylindrical. However, it is not limited to this, and while it is preferable for the top surface 21 of the first space 2 to be circular, it may be other shapes. For example, the first space 2 may be formed into a hemispherical shape or various other shapes.

[0015] In this embodiment, the bottom surface 22 and side surface 23 of the first space 2 are defined by the first member 8. Furthermore, the top surface 21 of the first space 2 is defined by the second member 10.

[0016] The second space 4 is a hollow space surrounded by a top surface 41, a bottom surface 42, and a side surface 43. In this embodiment, both the top surface 41 and the bottom surface 42 are circular with radius R1 (see Figure 3). That is, the second space 4 is cylindrical. However, it is not limited to this, and while it is preferable for the top surface 41 of the second space 4 to be circular, it may be of other shapes. The second space 4 may be formed into, for example, a hemispherical shape or various other shapes.

[0017] The bottom surface 42 and the side surface 43 of the second space 4 of the present embodiment are defined by the first member 8, similar to the first space 2. Further, the top surface 41 of the second space 4 is defined by the second member 10, similar to the first space 2.

[0018] The areas of the top surface 21 of the first space 2 and the top surface 41 of the second space 4 may be formed to be equal. More preferably, the top surface 21 of the first space 2 and the top surface 41 of the second space 4 may be formed in the same shape. As shown in FIG. 3, the top surface 21 of the first space 2 and the top surface 41 of the second space 4 of the present embodiment are both formed to be circular with a radius R1. However, the top surface 21 of the first space 2 and the top surface 41 of the second space 4 may be formed in different shapes from each other.

[0019] The first space 2 and the second space 4 may be formed to have equal volumes. The top surface 21, the bottom surface 22 of the first space 2, the top surface 41, and the bottom surface 42 of the second space 4 of the present embodiment are all circular with a radius R1. Further, the magnitudes in the height direction (the direction of arrow Z in FIG. 2) of the side surface 23 of the first space 2 and the side surface 43 of the second space 4 are formed to be equal. Thereby, the first space 2 and the second space 4 of the present embodiment are formed in a cylindrical shape with a radius R1 and equal volumes. However, the first space 2 and the second space 4 may be formed in different shapes from each other.

[0020] The radius R1 of the first space 2 and the second space 4 of the present embodiment is formed within a range of approximately 25 mm to 100 mm. The magnitude of the radius R1 may be approximately 10 mm to 200 mm. Further, the magnitudes in the height direction (the direction of arrow Z in FIG. 2) of the first space 2 and the second space 4 are formed within a range of approximately 10 mm to 30 mm. The magnitudes in the height direction of the first space 2 and the second space 4 may be approximately 5 mm to 50 mm.

[0021] The first space 2 and the second space 4 are arranged adjacent to each other. The first space 2 and the second space 4 in the present embodiment are arranged side by side with a distance of approximately 10 mm along the longitudinal direction (the direction of arrow X in FIG. 2).

[0022] The passage 6 is a hollow space located between the first space 2 and the second space 4, connecting the first space 2 and the second space 4. The passage 6 is surrounded by a top surface 61, a bottom surface 62 opposite the top surface 61, a first side surface 63, and a second side surface 64 opposite the first side surface 63. In this embodiment, the bottom surface 62, the first side surface 63, and the second side surface 64 of the passage 6 are defined by the first member 8. Furthermore, the top surface 61 of the passage 6 is defined by the second member 10.

[0023] As shown in Figure 3, the passage 6 connects the first space 2 and the second space 4 by the shortest distance L at the position where the distance between the first space 2 and the second space 4 is smallest.

[0024] As shown in Figure 2, the passage 6 in this embodiment is a quadrilateral shape with a roughly rectangular cross-section. The size of the passage 6 in the height direction (direction Z of the arrow in Figure 2) is smaller than that of the first space 2 and the second space 4. The bottom surface 62 of the passage 6 in this embodiment is positioned above the bottom surface 22 of the first space 2 and the bottom surface 42 of the second space 4. Alternatively, the bottom surface 62 of the passage 6 may be formed on the same plane as the bottom surface 22 of the first space 2 and the bottom surface 42 of the second space 4.

[0025] The width of passage 6 (in the direction of the arrow Z in Figure 3) should be smaller than the radius R1 of the first space 2 and the second space 4, and should be approximately 5 mm to 10 mm. Furthermore, the width of passage 6 may be approximately 2 mm to 20 mm. In addition, passage 6 only needs to connect the first space 2 and the second space 4, and its shape can be changed in various ways.

[0026] The material forming the first member 8 is not particularly limited. However, from the viewpoint of reducing weight, a porous material is preferred for forming the first member 8. The porous material may be non-permeable, but one that is permeable is preferred. For example, if the first member 8 is formed of a porous material with a certain degree of permeability, the pressure in the first space 2 and the second space 4 can be adjusted to be the same as the outside. The porous material may also be used to adjust parameters such as humidity in the first space 2 and the second space 4 to be the same as the outside. Note that a certain degree of permeability means one that does not impair the effects of the present invention. In this embodiment, the first member 8 is formed of foamed polyurethane. The first member 8 is not limited to this, and may be formed of various materials such as foamed polyolefin such as foamed polypropylene or fibrous material.

[0027] The first member 8 of this embodiment is formed in a roughly rectangular parallelepiped shape. The first member 8 has a top surface 81 and a recess 82 provided on the top surface 81. As shown in Figure 3, the top surface 81 of this embodiment is a plane that extends along the length direction (arrow X direction in Figure 3) and the depth direction (arrow Y direction in Figure 3). The recess 82 of this embodiment surrounds the first space 2, the second space 4, and a part of the passage 6.

[0028] The first member 8 is not limited to this, however, it is sufficient for the first member 8 to surround at least a portion of the bottom surface 22(42) and / or side surface 23(43) of the first space 2 and the second space 4. As a result, at least a portion of the first space 2 and the second space 4 is surrounded by the breathable first member 8. Therefore, the sound-absorbing member 1 can maintain the temperature, air pressure, and humidity of the first space 2, the second space 4, and the passage 6 at a constant level with the outside.

[0029] The second member 10 is formed of a non-permeable membrane member. As shown by the pointillism in Figures 1 and 3, the second member 10 in this embodiment is a translucent thin film. The second member 10 in this embodiment is formed of TPU (Thermoplastic Polyurethane). However, the second member 10 is not limited to this and may be formed of various materials such as TPO (Thermoplastic Olefinic Elastomer) or EPDM (Ethylene Propylene Diene Methylene Linkage).

[0030] As shown in Figure 2, the second member 10 has a first portion 11, a second portion 12, and a third portion 13. The first portion 11 covers the top surface 21 of the first space 2. The second portion 12 covers the top surface 41 of the second space 4. The third portion 13 covers the top surface 61 of the passage 6.

[0031] As shown in Figure 3, the dimensions of the second member 10 in this embodiment in the longitudinal direction (X direction in Figure 3) and the depth direction (Y direction in Figure 3) are formed to be approximately equal to the top surface 81 of the first member 8.

[0032] In this embodiment, the second member 10 is bonded to the first member 8 by an adhesive that has been pre-applied to the top surface 81 of the first member 8. The second member 10 only needs to be bonded to the edge of the recess 82 on at least the top surface 81 of the first member 8. As a result, the second member 10 closes the top surface 21 of the first space 2, the top surface 41 of the second space 4, and the top surface 61 of the passage 6.

[0033] In this embodiment, the second member 10 is a vibrating membrane that covers the first space 2 and the second space 4. The portion of the second member 10 that covers the top surface 21 of the first space 2 and the top surface 41 of the second space 4 vibrates freely in accordance with the airflow inside the first space 2, the second space 4, and the passage 6. The thickness of the second member 10 is, for example, about 0.02 mm to 0.5 mm.

[0034] Next, the sound-dampening mechanism of the sound-dampening member 1 of this embodiment will be explained using Figure 4. Figure 4 is a schematic diagram showing the sound-dampening mechanism when sound P is input to the sound-dampening member 1. As shown in Figure 4, sound P having a predetermined frequency is input to the first space 2 via the first part 11 of the second member 10. At this time, the first part 11 of the second member 10 vibrates at a predetermined frequency according to the frequency and amplitude of sound P. In Figure 4, the first part 11 of the second member 10 that vibrates in response to the input of sound P is shown bulging out toward the first space 2.

[0035] Next, the sound P input to the first space 2 is transmitted from the first space 2 to the second space 4 via the passage 6. The first space 2 and the second space 4 have approximately equal volumes. Therefore, when the first part 11 of the second member 10 vibrates at a predetermined frequency corresponding to the sound P, the second part 12 of the second member 10 vibrates in response, with the same period as the first part 11.

[0036] The second part 12 vibrates in response to the vibration of the first part 11. In this embodiment, the areas of the top surface 21 of the first space 2 and the top surface 41 of the second space 4 are formed to be approximately equal. Therefore, when the first part 11 bulges outward toward the first space 2, the second part 12 bulges outward toward the second space 4. That is, the first part 11 and the second part 12 vibrate at the same frequency but in opposite phase. As a result, the second part 12 outputs sound P'. Here, the sound P' output by the second part 12 is in opposite phase and has the same frequency as the sound P input to the first part 11. As a result, the sound-dampening member 1 can cancel out the input sound P and silence it.

[0037] On the other hand, when sound P is input to the second space 4 side via the second part 12 of the second member 10, vibrations corresponding to sound P are transmitted from the second space 4 to the first space 2 via the passage 6. As a result, the first part 11 of the second member 10 can output sound P'. In this case as well, the sound P' output by the first part 11 is out of phase and has the same frequency as the sound P input to the second part 12. Therefore, when sound P is input to either the first space 2 or the second space 4, the sound-dampening member 1 can output sound P' which is out of phase and has the same frequency as the input sound P from the other of the first space 2 or the second space 4. As a result, the sound-dampening member 1 can mute the input sound P.

[0038] Furthermore, the sound-absorbing member 1 can target and silence sounds in a specific frequency band by adjusting the area of ​​the top surface 21 of the first space 2 and the top surface 41 of the second space 4, the volume of the first space 2 and the second space 4, and the thickness of the second member 10. In this embodiment, the top surface 21 of the first space 2 and the top surface 41 of the second space 4 are formed as circles with radius R1. This allows the sound-absorbing performance to be easily adjusted according to the frequency band to be silenced by appropriately changing the radius R1.

[0039] <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to Figures 5 to 7. As shown in Figure 5, the sound-absorbing member 101 of the second embodiment comprises a first space 102, a second space 104, a passage 106, a first member 108, a second member 110, and a third member 112. The first space 102, the second space 104, and the passage 106 of this embodiment overlap with those of the first embodiment, so their description will be omitted.

[0040] The first member 108 has a base portion 108a, a first wall portion 108b, a second wall portion 108c, and a third wall portion 108d. The first member 108 in this embodiment is formed from a thermoplastic resin material such as polypropylene, polyethylene, ABS resin (acrylonitrile-butadiene-styrene copolymer), or PC resin (polycarbonate resin).

[0041] The base portion 108a is a plate-like member that extends along the length direction (arrow X direction in Figure 5) and the depth direction (arrow Y direction in Figure 5). In this embodiment, the size of the base portion 108a in the height direction (arrow Z direction in Figure 5) is formed to be approximately 5 mm to 10 mm.

[0042] The first wall portion 108b is positioned on the base portion 108a and extends in the height direction. Together with the base portion 108a, the first wall portion 108b surrounds the first space 102. In this embodiment, the first wall portion 108b is formed in the shape of a thin-walled cylinder with a hollow interior.

[0043] The second wall portion 108c is positioned on the base portion 108a and extends in the height direction, similar to the first wall portion 108b. Together with the base portion 108a, the second wall portion 108c surrounds the second space 104. In this embodiment, the second wall portion 108c is formed in the same shape as the first wall portion 108b.

[0044] The first wall portion 108b and the second wall portion 108c are arranged side by side on the base portion 108a.

[0045] The third wall section 108d is a pair of vertical walls positioned between the first wall section 108b and the second wall section 108c. The third wall section 108d surrounds the passage 106.

[0046] The second member 110 is a thin film positioned between the first member 108 and the third member 112. Similar to the first embodiment, the second member 110 in this embodiment is formed of a non-permeable membrane member and covers the first space 102, the second space 104, and the passage 106.

[0047] In this embodiment, the second member 110 is sandwiched and fixed between the first member 108 and the third member 112.

[0048] The third member 112 covers the first member 108 and the second member 110. In this embodiment, the third member 112 is made of the same thermoplastic resin material as the first member 108.

[0049] The third member 112 has a fixing portion 112a, a first opening 112b, and a second opening 112c.

[0050] As shown in Figure 7, the fixing portion 112a fixes the third member 112 to the first member 108. In this embodiment, the fixing portion 112a is a flange extending from the side surface of the third member 112. The fixing portion 112a is attached to the side surface of the first member 108. As a result, the third member 112 is fixed to the first member 108. Consequently, the second member 110 is fixed between the first member 108 and the third member 112, covering the first space 102, the second space 104, and the passage 106.

[0051] The fixing portion 112a may be fixed to the first member 108 by various methods. In addition, the second member 110 may be fixed to the first member 108 or the third member 112 in advance using adhesive.

[0052] The first opening 112b is positioned above the first space 2 with the third member 112 fixed to the first member 108. Similarly, the second opening 112c is positioned above the second space 4.

[0053] As shown in Figure 6, the first opening 112b and the second opening 112c in this embodiment are louvers. This allows the first opening 112b and the second opening 112c to protect the first member 108 and the second member 110 without obstructing the transmission of sound input to and output to the sound-absorbing member 101. However, the first opening 112b and the second opening 112c may be formed as a honeycomb or other geometric grid structure.

[0054] As explained above, this disclosure provides a sound-absorbing member with a simple structure that can be installed in narrower spaces.

[0055] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0056] For example, in the above embodiment, the first space 2,102 and the second space 4,104 of the sound-absorbing member 1,101 are formed as cylindrical shapes with radius R1, but the disclosure is not limited thereto. That is, the shape of the top surfaces of the first space 2,102 and the second space 4,104 is not limited to circular shapes, and they may have different shapes from each other. The sound-absorbing member 1,101 only needs to have equal volumes for the first space 2,102 and the second space 4,104, and the shape and film thickness of the second members 10,110 covering them to be the same.

[0057] Furthermore, in the above embodiment, the first members 8,108 of the sound-absorbing member 1,101 surround the bottom and sides of the first space 2,102 and the second space 4,104, but the disclosure is not limited thereto. That is, the first member 8,108 may have through-holes in the shape of the first space 2,102, the second space 4,104 and the passage 6,106. In this case, one end of the through-hole may be covered by the second members 10,110, and the other end may be covered by a part of the roof liner on which the sound-absorbing member 1,101 is installed.

[0058] Furthermore, although the sound-absorbing member 1,101 in the above embodiment was installed in the roof liner of an automobile, this disclosure is not limited thereto. That is, the sound-absorbing member 1,101 may be installed in the instrument panel or various body members of an automobile. In this case, the sound-absorbing member 1,101 only needs to be positioned so that the second members 10,110 face the sound source.

[0059] Furthermore, although the sound-absorbing member 1,101 in the above embodiment was installed in an automobile, this disclosure is not limited thereto. That is, the sound-absorbing member 1,101 may be installed in the walls of a house or building.

[0060] Furthermore, while the sound-absorbing member 1,101 in the above embodiment is provided with one first space 2,102, one second space 4,104, and one passage 6,106, the disclosure is not limited thereto. That is, the sound-absorbing member 1,101 may have multiple first spaces 2,102 and second spaces 4,104 connected by passage 6,106. In this case, the first members 8,108 may be formed to match the size of the installation location and the curvature of the surface.

[0061] Furthermore, although the first members 8,108 in the above embodiment are formed of a porous material having a certain degree of breathability, the disclosure is not limited thereto. That is, the material forming the first member 8,108 may be non-breathable. In this case, adjustment valves or the like may be provided to adjust parameters such as pressure and humidity in the first space 2,102 and the second space 4,104 to the same level as the outside. [Explanation of Symbols]

[0062] 1,101: Sound-absorbing material 2,102: 1st space 4,104:Second space 6,106: Passageway 8,108: First member 10,110: Second member 112: Third member

Claims

1. The first space and, A second space is arranged adjacent to the first space, A passage connecting the first space and the second space, A first member that surrounds the bottom and / or side surfaces of the first space, the second space and the passage, A membrane-like second member covering the top surface of the first space, the second space, and the passage, A third member covering the first member and the second member, Equipped with, The third member is a sound-absorbing member that fixes the second member to the first member by sandwiching the second member between the third member and the first member.

2. The first space and, A second space is arranged adjacent to the first space, A passage connecting the first space and the second space, A first member that surrounds the bottom and / or side surfaces of the first space, the second space and the passage, A membrane-like second member covering the top surface of the first space, the second space, and the passage, A third member covering the first member and the second member, Equipped with, The third member fixes the second member to the first member by sandwiching the second member between the third member and the first member. The third member covers the second member which covers the top surface of the passage and has a first opening and a second opening. The first opening is positioned above the first space with the third member fixed to the first member. The second opening is a sound-absorbing member positioned above the second space, with the third member fixed to the first member.

3. The sound-absorbing member according to claim 2, wherein the first opening or the second opening forms a louver, honeycomb, or geometric grid structure.

4. The sound-absorbing member according to any one of claims 1 to 3, wherein the second member is non-permeable.

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