JP2024077300A - Sound absorbing panels - Google Patents

Abstract

[Problem] To provide a sound-absorbing panel that improves sound-absorbing performance and ensures sufficient rigidity. [Solution] A sound-absorbing panel 1 comprises a front plate 2 having a plurality of holes 2a, a rear plate 3 arranged at a fixed interval from the front plate 2, a plurality of ribs 4 arranged at a fixed interval between the front plate 2 and the rear plate 3, and a plurality of sound-absorbing materials 5 arranged between the ribs 4 between the front plate 2 and the rear plate 3, the rear plate 3 being constituted by a corrugated plate 21 having first convex portions 22 facing the front side and second convex portions 23 facing the rear side arranged alternately, the sound-absorbing materials 5 and the first convex portions 22 being joined to each other, and an air layer E being formed between the sound-absorbing materials 5 and the second convex portions 23 of the corrugated plate 21. [Selected Figure] Figure 2

Description

This disclosure relates to sound-absorbing panels.

Conventionally, sound-absorbing panels that absorb noise generated under the floor when a railway vehicle is traveling, for example, are known. For example, the railway vehicle sound-absorbing panel described in Patent Document 1 includes a sound-absorbing material that absorbs noise from the bogie under the railway vehicle. This conventional sound-absorbing panel includes a surface protective material, a back panel, a number of ribs provided at predetermined intervals between the surface protective material and the back panel, and a sound-absorbing material stored between the ribs between the surface protective material and the back panel. An air layer is provided between the sound-absorbing material and the surface protective material.

JP 2007-283842 A

Sound-absorbing panels like those mentioned above are required to have improved sound-absorbing performance against various kinds of sounds, such as rolling noise generated under the floor when a train is moving, sound generated under the floor and reflected by soundproofing walls, and the operating noise of equipment placed under the floor. In addition, because they are placed under the floor of trains, they are expected to be hit by flying stones and ice while the train is moving, and airtight loads will be added when entering a tunnel, so they are required to have sufficient rigidity to withstand such loads.

This disclosure has been made to solve the above problems, and aims to provide a sound-absorbing panel that improves sound-absorbing performance and ensures sufficient rigidity.

A sound-absorbing panel according to one aspect of the present disclosure comprises a front panel having a plurality of holes, a rear panel arranged at a fixed distance from the front panel, a plurality of ribs arranged at fixed distances between the front panel and the rear panel, and a plurality of sound-absorbing materials arranged between the ribs between the front panel and the rear panel, the rear panel being constituted by a corrugated panel having alternating first convex portions facing the front panel and second convex portions facing the rear panel, the sound-absorbing materials and the first convex portions being joined to each other, and an air layer being formed between the sound-absorbing materials and the second convex portions of the corrugated panel.

In this sound-absorbing panel, the back plate is made of a corrugated plate in which first and second convex portions are arranged alternately. By using a corrugated plate for the back plate, which serves as the base of rigidity in the sound-absorbing panel, the rigidity of the sound-absorbing panel can be sufficiently increased compared to when a flat plate is used for the back plate. In addition, in this sound-absorbing panel, an air layer is formed between the sound-absorbing material and the second convex portions by utilizing the shape of the corrugated plate. By forming an air layer on the back side of the sound-absorbing material, the sound-absorbing efficiency of the sound-absorbing material can be improved. Therefore, this sound-absorbing panel improves sound-absorbing performance and ensures sufficient rigidity.

The corrugated sheet and the ribs may be constructed as a single unit. In this case, the joining of the corrugated sheet and the ribs can be omitted. This simplifies the construction of the sound-absorbing panel.

A perforated plate may be placed between the sound absorbing material and the corrugated plate. In this case, a resonant sound absorber is formed by the air layer on the surface side of the corrugated plate and the perforated plate, making it possible to expand the frequency range that can be absorbed.

A pair of perforated plates may be arranged to sandwich the corrugated plate. The air layers on the front and back sides of the corrugated plate and the perforated plates form a resonant sound absorber, making it possible to further expand the frequency range that can be absorbed.

The first and second convex portions may have a trapezoidal cross section. In this case, an air layer can be formed with a sufficient volume. In addition, since the top surface of the first convex portion is a flat surface, it is easy to join the sound absorbing material to the first convex portion.

The rib may be disposed at a position corresponding to the second protrusion. In this case, the rib protrudes toward the corrugated sheet side from the back surface of the sound-absorbing material, so the length of the rib can be made sufficiently long. By ensuring a sufficient length of the rib, the rigidity of the sound-absorbing panel can be improved.

The rib may be positioned at a position corresponding to the first convex portion. In this case, the rib is positioned to correspond to the first convex portion facing the front surface, so the length of the rib can be sufficiently short. By reducing the length of the rib, the bending rigidity of the sound-absorbing panel can be improved and the weight can be reduced.

This disclosure aims to improve sound absorption performance and ensure sufficient rigidity.

FIG. 2 is a front view of an acoustic panel according to one embodiment of the present disclosure. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 4 is a partially enlarged cross-sectional view showing the joining structure between the surface plate and the rib. 4 is a partially enlarged cross-sectional view showing an example of the positional relationship between a rib and a first protrusion and a second protrusion of the corrugated plate. FIG. 11 is a partially enlarged cross-sectional view showing another example of the positional relationship between the rib and the first and second protrusions of the corrugated plate. FIG. FIG. 11 is a partially enlarged cross-sectional view showing a modified example of the porous plate.

Below, a preferred embodiment of a sound-absorbing panel according to one aspect of the present disclosure will be described in detail with reference to the drawings.

Figure 1 is a front view of a sound-absorbing panel according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The sound-absorbing panel 1 shown in Figures 1 and 2 is a member that is placed on, for example, the skirt portion of the side of a railway vehicle. The sound-absorbing panel 1 absorbs various types of sounds generated when the railway vehicle is running, reducing noise. Examples of sounds that can be absorbed by the sound-absorbing panel 1 include rolling noise (vibration noise generated when the wheels rotate on the rails while moving) generated under the floor when the railway vehicle is running, reflected sound generated under the floor and reflected by a soundproof wall, and driving noise of equipment placed under the floor (for example, motors and gears placed on a bogie).

As shown in Figs. 1 and 2, the sound-absorbing panel 1 is composed of a front plate 2, a back plate 3, a plurality of ribs 4, a plurality of sound-absorbing materials 5, and a perforated plate 6. For ease of explanation, Figs. 1 and 2 show an orthogonal coordinate system with X, Y, and Z axes. When the sound-absorbing panel 1 is attached to a railway vehicle, the X axis corresponds to the longitudinal direction (rail direction) of the railway vehicle, the Y axis corresponds to the width direction (sleeper direction) of the railway vehicle, and the Z axis corresponds to the height direction of the railway vehicle. In addition, as necessary, the side of the front plate 2 will be referred to as the front surface (front face) of the sound-absorbing panel 1, and the side of the back plate 3 will be referred to as the back face of the sound-absorbing panel 1.

The surface plate 2 is a plate that faces outward on the side of the railway vehicle when the sound-absorbing panel 1 is attached to the railway vehicle. The surface plate 2 is made of a rigid material such as aluminum or an aluminum alloy from the viewpoint of durability against loads such as collisions with flying stones and ice while the railway vehicle is traveling and the addition of airtight loads when entering a tunnel, and from the viewpoint of reducing the weight of the railway vehicle to which it is attached. When viewed from the Y-axis direction, the surface plate 2 is, for example, rectangular. The thickness of the surface plate 2 is, for example, around 1 mm. When viewed from the X-axis direction, the surface plate 2 may be gently curved, for example, convex outward, depending on the cross-sectional shape of the lower part of the side of the railway vehicle to which it is attached.

The surface plate 2 has a number of holes 2a that serve as sound intakes (see FIG. 1). The holes 2a are arranged in a staggered or lattice pattern at a fixed pitch when viewed from the front of the surface plate 2. Each hole 2a is a through hole that extends from the front to the back of the surface plate 2. The diameter of the holes 2a is, for example, about 1 mm to several mm. The open area ratio of the surface plate 2 due to the holes 2a is, for example, about 15% to 30%. The surface plate 2 may be made of a single plate, or may be made by joining divided members divided in the Z-axis or X-axis direction to each other.

When the surface plate 2 is made up of divided members divided in the Z-axis or X-axis direction, the aperture ratio of the surface plate 2 due to the holes 2a of each divided member may be equal to each other or may be different from each other. When the aperture ratios are to be different, for example, divided members with aperture ratios of 30%, 20%, and 15% may be used in combination. For example, the surface plate 2 may be divided in the Z-direction by divided members, and a divided member with an aperture ratio of 30%, a divided member with an aperture ratio of 20%, and a divided member with an aperture ratio of 15% may be arranged in that order from the top.

The rear plate 3 is a plate that faces the inside of the side of the railway vehicle when the sound-absorbing panel 1 is attached to the railway vehicle. Like the front plate 2, the rear plate 3 is made of a rigid material such as aluminum or an aluminum alloy from the viewpoint of durability against loads such as collisions with flying stones and ice while the railway vehicle is traveling and the addition of an airtight load when entering a tunnel, and from the viewpoint of reducing the weight of the railway vehicle to which it is attached. When viewed from the Y-axis direction, the rear plate 3 is, for example, rectangular. When viewed from the X-axis direction, the rear plate 3 is, for example, linear overall. The thickness of the rear plate 3 is, for example, around 1 mm.

The rear plate 3 is disposed at a fixed distance from the front plate 2, and a space S for the sound-absorbing material 5 is formed between the rear plate 3 and the front plate 2 (see FIG. 2). In this embodiment, the rear plate 3 is divided into three in the Z-axis direction by dividing members 3A to 3C. Divided members 3A, 3B, and 3C are arranged in this order from above in the Z-axis direction. The lower end of divided member 3A and the upper end of divided member 3B are butted together and joined by welding or the like. The lower end of divided member 3B and the upper end of divided member 3C are butted together and joined by welding or the like.

The upper end of the dividing member 3A is provided with a flange portion 11A used to attach the sound-absorbing panel 1 to the railway vehicle. The flange portion 11A has a hollow base end portion 12A that protrudes further toward the front side than the main body portion of the back plate 3, and a tip portion 13A that protrudes upward along the Z axis from the base end portion 12A so as to be continuous with the front plate 2. The upper end of the front plate 2 is joined to the wall portion on the front side of the base end portion 12A by a joining means such as welding or riveting. The tip portion 13A is provided with insertion holes 14A at both ends and the center in the X axis direction, for example. The upper side of the sound-absorbing panel 1 is fixed to the railway vehicle by inserting joining members such as bolts into these insertion holes 14A and screwing them into bolt holes on the vehicle side.

The lower end of the dividing member 3C is provided with a flange portion 11B used to attach the sound-absorbing panel 1 to the railway vehicle. The flange portion 11B has a hollow base end portion 12B that protrudes further toward the front side than the main body of the back plate 3, and a tip portion 13B that protrudes downward along the Z axis from the base end portion 12B so as to be continuous with the main body of the back plate 3. The lower end of the front plate 2 is joined to the wall portion on the front side of the base end portion 12B by a joining means such as welding or riveting. The tip portion 13B is provided with insertion holes 14B at both ends and the center in the X axis direction, for example. The lower side of the sound-absorbing panel 1 is fixed to the railway vehicle by inserting joining members such as bolts into these insertion holes 14B and screwing them into bolt holes on the vehicle side.

The ribs 4 are strength members for ensuring the rigidity of the sound-absorbing panel 1. The ribs 4 are formed of a rigid material such as aluminum or an aluminum alloy, for example, like the front plate 2 and the rear plate 3. The ribs 4 are arranged between the front plate 2 and the rear plate 3 so as to connect the front plate 2 and the rear plate 3, and extend in the X-axis direction with the same length as the front plate 2 and the rear plate 3. In this embodiment, four ribs 4 are arranged at predetermined intervals in the Z-axis direction. The topmost rib 4 also serves as the lower wall of the hollow base end 12A of the divided member 3A that constitutes the rear plate 3. The bottommost rib 4 also serves as the upper wall of the hollow base end 12B of the divided member 3C that constitutes the rear plate 3.

The ends 4a of the two central ribs 4 on the side of the surface plate 2 are provided with bent portions 16 that bend along the surface plate 2, as shown in FIG. 3. The bent portions 16 are used to join the surface plate 2 and the ribs 4. With the bent portions 16 aligned along the surface plate 2, the surface plate 2 and the bent portions 16 are joined by a joining means such as welding or riveting, thereby joining the surface plate 2 and the ribs 4.

Returning to Figures 1 and 2, the sound-absorbing material 5 is a member that absorbs sound taken in through the holes 2a in the surface panel 2. The sound-absorbing material 5 is made of a fibrous material such as glass wool. In glass wool, the energy of the incident sound vibrates the fibers and the air between the fibers, converting it into thermal energy, thereby providing a sound-absorbing effect. When viewed from the Y-axis direction, the sound-absorbing material 5 has, for example, a rectangular shape. The thickness of the sound-absorbing material 5 is, for example, about several tens of mm.

The sound-absorbing material 5 is disposed between the ribs 4 in the space S between the front panel 2 and the back panel 3. In this embodiment, the space S is divided into three regions in the Z-axis direction by the four ribs 4 described above. By disposing a sound-absorbing material 5 in each of these regions, three sound-absorbing materials 5 are arranged in the Z-axis direction. A small gap may be formed between the sound-absorbing material 5 and the front panel 2 in the Y-axis direction. A small gap may be formed between the sound-absorbing material 5 and the ribs 4 in the Z-axis direction.

The perforated plate 6 is a member that constitutes a resonant sound absorber in cooperation with the sound-absorbing material 5 (see FIG. 2). The perforated plate 6 is formed of a metal material such as aluminum in a rectangular shape that is slightly smaller than the sound-absorbing material 5. The thickness of the perforated plate 6 is, for example, smaller than the front plate 2 and approximately the same as the back plate 3. The thickness of the perforated plate 6 is, for example, approximately 1 mm. The perforated plate 6 is fixed to the back side of each of the sound-absorbing materials 5 by gluing or the like. The sound-absorbing material 5 efficiently absorbs sounds in the mid- to high-frequency range, and the resonant sound absorber using the perforated plate 6 efficiently absorbs sounds in the low-frequency range, thereby expanding the frequency range that can be absorbed by the sound-absorbing panel 1.

The perforated plate 6 has a number of holes 6a (see FIG. 4). When viewed from the front of the perforated plate 6, the holes 6a are arranged in a staggered or lattice pattern at a fixed pitch. Each hole 6a is a through hole that extends from the front surface to the back surface of the perforated plate 6. The diameter of the hole 6a is, for example, about 1 mm to several mm. By adjusting the plate thickness, hole diameter, and air layer thickness of the perforated plate 6, sounds in any frequency range can be efficiently absorbed.

Next, we will explain the configuration of the back plate 3 described above in more detail.

As shown in Figs. 1 and 2, in the sound-absorbing panel 1, the back plate 3 is composed of a corrugated plate 21 in which first protrusions 22 facing the front side and second protrusions 23 facing the back side are arranged alternately. In this embodiment, the first protrusions 22 and second protrusions 23 of the corrugated plate 21 each have a trapezoidal cross section and extend in the X-axis direction over the entire length of the back plate 3 in the X-axis direction.

As shown in Figs. 2 and 4, the first protrusion 22 is joined to the back side of the sound absorbing material 5. More specifically, in this embodiment, the top surface 22a of the first protrusion 22 is in contact with the perforated plate 6 on the back side of the sound absorbing material 5. The perforated plate 6 is joined to the top surface 22a of the first protrusion 22 by a joining means such as welding or riveting. In other words, in this embodiment, the first protrusion 22 is joined to the back side of the sound absorbing material 5 via the perforated plate 6.

As shown in Figures 2 and 4, the top surface 23a of the second protrusion 23 is spaced apart from the rear surface of the perforated plate 6 at a fixed distance in the Y-axis direction. Therefore, an air layer E is formed between the sound-absorbing material 5 (the perforated plate 6 on the rear surface side of the sound-absorbing material 5) and the second protrusion 23. The air layer E is defined by the second protrusion 23 to have a trapezoidal cross section, and extends in the X-axis direction over the entire length of the rear surface plate 3 in the X-axis direction.

In the sound-absorbing panel 1, the corrugated sheet 21 and the ribs 4 are formed as a single unit using an extruded molding material. In this embodiment, as shown in FIG. 2, the flange portion 11A including the base end portion 12A that also serves as the top rib 4 and the dividing member 3A are formed as a single unit using an extruded molding material, and the two ribs 4 in the center and the dividing member 3B are formed as a single unit using an extruded molding material. In addition, the flange portion 11B including the base end portion 12B that also serves as the bottom rib 4 and the dividing member 3C are formed as a single unit using an extruded molding material.

In this embodiment, as shown in FIG. 4, the rib 4 is disposed at a position corresponding to the second protrusion 23. In the example of FIG. 4, the top surface 23a of the second protrusion 23 of the corrugated plate 21 is positioned so as to straddle the sound absorbing materials 5, 5 in the Z-axis direction. The end portion 4b on the back side of the rib 4 protrudes toward the back plate 3 (corrugated plate 21) side more than the back surface of the sound absorbing material 5, and is connected to the central portion in the Z-axis direction of the top surface 23a of the second protrusion 23. As a result, an air layer E having a cross-sectional shape different from the air layer E is formed in the vicinity of the corner 5a on the back plate 3 side of the sound absorbing material 5 by being surrounded by the corner 5a, the rib 4, and a half portion of the second protrusion 23.

As described above, in the sound-absorbing panel 1, the back plate 3 is composed of a corrugated plate 21 in which the first convex portions 22 and the second convex portions 23 are arranged alternately. By using the corrugated plate 21 for the back plate 3, which is the base of rigidity in the sound-absorbing panel 1, the rigidity of the sound-absorbing panel 1 can be sufficiently increased compared to the case where a flat plate is used for the back plate 3. In addition, in the sound-absorbing panel 1, an air layer E is formed between the sound-absorbing material 5 and the second convex portions 23 by utilizing the shape of the corrugated plate 21. By forming the air layer E on the back side of the sound-absorbing material 5, the sound-absorbing efficiency of the sound-absorbing material 5 can be improved. Therefore, the sound-absorbing panel 1 improves the sound-absorbing performance and ensures sufficient rigidity. Since there is no need to process the shape of the sound-absorbing material 5 in a complex manner to form the air layer E, the manufacturing cost can also be reduced.

In this embodiment, the corrugated sheet 21 and the ribs 4 are constructed as a single unit. This eliminates the need to join the corrugated sheet 21 and the ribs 4. This simplifies the structure of the sound-absorbing panel 1.

In this embodiment, a perforated plate 6 is placed between the sound absorbing material 5 and the corrugated plate 21. In this case, a resonant sound absorber is formed by the air layer on the surface side of the corrugated plate 21 and the perforated plate 6, making it possible to expand the frequency band that can be absorbed.

In this embodiment, the first convex portion 22 and the second convex portion 23 have a trapezoidal cross section. This allows the air layer E to be formed with a sufficient volume. In addition, the top surface 22a of the first convex portion 22 is a flat surface, making it easy to join the sound absorbing material 5 to the first convex portion 22.

In this embodiment, the rib 4 is disposed at a position corresponding to the second protrusion 23. This allows the rib 4 to protrude toward the corrugated plate 21 side from the rear surface of the sound-absorbing material 5, making the length of the rib 4 sufficiently long. By ensuring a sufficient length of the rib 4, the rigidity of the sound-absorbing panel 1 can be improved.

The present disclosure is not limited to the above embodiment. For example, in the above embodiment, the rib 4 is disposed at a position corresponding to the second convex portion 23, but as shown in FIG. 5, the rib 4 may be disposed at a position corresponding to the first convex portion 22. In the example of FIG. 5, the top surface 22a of the first convex portion 22 of the corrugated sheet 21 is positioned so as to straddle the sound absorbing materials 5, 5 in the Z-axis direction. The end portion 4b on the back side of the rib 4 is connected to the central portion in the Z-axis direction of the top surface 22a of the first convex portion 22.

With this configuration, the ribs 4 are positioned in correspondence with the first protrusions 22 facing the front surface, so the length of the ribs 4 can be made sufficiently short. By reducing the length of the ribs 4, the bending rigidity of the sound-absorbing panel 1 is improved and the weight is reduced. In the example of FIG. 5, the perforated plate 6 extends to the corners 5a of the sound-absorbing material 5, and the corners 5a of the sound-absorbing material 5 come into contact with the top surfaces 22a of the first protrusions 22 via the perforated plate 6, so that no gaps are created near the corners 5a. This makes it possible to prevent foreign matter such as dust from accumulating in the air layer E.

In the above embodiment, the corrugated sheet 21 and the ribs 4 are configured as an integral member, but the corrugated sheet 21 and the ribs 4 may be formed as separate members and joined by joining means such as welding or riveting. Also, in the above embodiment, the perforated sheet 6 is disposed between the sound absorbing material 5 and the corrugated sheet 21, but the arrangement of the perforated sheet 6 may be omitted. In this case, the top surface 22a of the first convex portion 22 may be directly contacted with the back surface of the sound absorbing material 5, and the sound absorbing material 5 and the first convex portion 22 may be joined by adhesive or the like.

In the above embodiment, the first convex portion 22 and the second convex portion 23 have a trapezoidal cross section, but the cross-sectional shape of the first convex portion 22 and the second convex portion 23 may be other shapes such as a triangle, a square, a rectangle, a semicircle, or a semi-ellipse.

In the embodiment shown in FIG. 4, a perforated plate 6 is disposed between the sound absorbing material 5 and the corrugated plate 21, but as shown in FIG. 6, a pair of perforated plates 6, 6 may be disposed to sandwich the corrugated plate 21. The perforated plate 6 on the back side of the corrugated plate 21 can be joined to the top surface 23a of the second protrusion 23 by a joining means such as welding or riveting. With this configuration, a resonant sound absorber is formed by the air layers on the front and back sides of the corrugated plate 21 and the perforated plate 6, so that the frequency band that can be absorbed can be further expanded. In addition, when the sound absorbing panel 1 is disposed on the skirt portion of the side of the railway vehicle, it can efficiently absorb noise generated by the vehicle's underfloor equipment or bogies.

The gist of the present disclosure is as follows: [1] to [7]
[1] A sound-absorbing panel comprising: a front plate having a plurality of holes; a rear plate arranged at a fixed interval from the front plate; a plurality of ribs arranged at fixed intervals between the front plate and the rear plate; and a plurality of sound-absorbing materials arranged between the ribs between the front plate and the rear plate, wherein the rear plate is constituted by a corrugated plate in which first convex portions facing the front side and second convex portions facing the rear side are alternately arranged, the sound-absorbing materials and the first convex portions are bonded to each other, and an air layer is formed between the sound-absorbing materials and the second convex portions of the corrugated plate.
[2] The sound-absorbing panel according to [1], wherein the corrugated sheet and the ribs are formed as a single integral member.
[3] The sound-absorbing panel according to [1] or [2], wherein a perforated plate is disposed between the sound-absorbing material and the corrugated plate.
[4] The sound-absorbing panel according to any one of [1] to [3], wherein a pair of perforated plates are arranged to sandwich the corrugated plate.
[5] The sound-absorbing panel according to any one of [1] to [4], wherein the first convex portion and the second convex portion have a trapezoidal cross section.
[6] The sound-absorbing panel according to any one of [1] to [5], wherein the rib is arranged at a position corresponding to the second convex portion.
[7] The sound-absorbing panel according to any one of [1] to [5], wherein the rib is arranged at a position corresponding to the first convex portion.

1...sound-absorbing panel, 2...front plate, 2a...holes, 3...back plate, 4...ribs, 5...sound-absorbing material, 6...perforated plate, 21...corrugated plate, 22...first convex portion, 23...second convex portion, E...air layer.

Claims (7)

a surface plate having a plurality of holes;
A back plate arranged at a certain distance from the front plate;
A plurality of ribs arranged at regular intervals between the front plate and the rear plate;
a plurality of sound absorbing materials disposed between the ribs and between the front panel and the rear panel;
The back plate is formed of a corrugated plate in which first convex portions facing the front side and second convex portions facing the back side are alternately arranged,
A sound-absorbing panel, wherein the sound-absorbing material and the first convex portion are joined to each other, and an air layer is formed between the sound-absorbing material and the second convex portion of the corrugated plate. The sound-absorbing panel of claim 1, in which the corrugated sheet and the ribs are formed as a single unit. The sound-absorbing panel according to claim 1, wherein a perforated plate is disposed between the sound-absorbing material and the corrugated plate. The sound-absorbing panel according to claim 1, in which a pair of perforated plates are arranged to sandwich the corrugated plate. The sound-absorbing panel according to claim 1, wherein the first convex portion and the second convex portion have a trapezoidal cross section. The sound-absorbing panel according to any one of claims 1 to 5, wherein the rib is disposed at a position corresponding to the second protrusion. The sound-absorbing panel according to any one of claims 1 to 5, wherein the rib is disposed at a position corresponding to the first protrusion.

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