JP5250310B2 - Sound absorbing structure - Google Patents

Description

  The present invention relates to a sound absorbing structure.

  As this type of technology, for example, a porous sound absorbing structure disclosed in Japanese Patent Application Laid-Open No. 2005-338895 is cited. The porous sound absorbing structure is formed by opposingly arranging a first outer member and at least one or more inner members in which a plurality of through holes are formed along a plane. The diameter and the aperture ratio are set so as to generate a viscous action on the air flowing through the through hole. On the opposite side of the first outer member with respect to the inner member, a second outer member having a plurality of through holes formed along a plane is disposed opposite the inner member. The opening ratio of the through hole of the second outer member is more than 3% and 50% or less (refer to claim 1, FIG. 1, etc. of JP-A-2005-338895).

  Incidentally, the applicant of the present application has filed Japanese Patent Application No. 2007-274818 (hereinafter referred to as Patent Document 1). This patent document 1 discloses a sound absorbing structure that can absorb sound from a sound source. The sound absorbing structure includes a box member having a porous surface with a large number of openings, a perforated plate having a large number of openings and dividing the internal space of the box member, and a plurality of support frames. . The perforated plate is supported in the box member by sandwiching the outer peripheral portion of the perforated plate between the support frames (see paragraph number 0109 of Patent Document 1 and FIG. 2). . The perforated plate can be moved relative to the support frame in the in-plane direction.

  Although the above sound absorbing structure is excellent in terms of assemblability, there is still room for improvement in terms of the sound absorbing effect.

  The present invention has been made in view of such various points, and its main object is to provide a sound absorbing structure that is further excellent in sound absorbing effect as compared with the sound absorbing structure disclosed in Patent Document 1. It is in.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above, and the inventors of the present invention have found that, as a result of intensive research, it is beneficial to improve the sound absorption effect to suppress the vibration of the porous plate as much as possible. The following invention has been completed. Next, means for solving this problem and effects thereof will be described.

  According to the viewpoint of this invention, the sound-absorbing structure comprised as follows is provided. That is, the sound absorbing structure includes a housing having a surface plate in which a large number of holes are formed, a porous plate that partitions the internal space of the housing in the normal direction of the surface plate, and the porous body with respect to the housing. And a support that supports the plate. The support body fixedly supports the porous plate with respect to the housing in the normal direction and in-plane direction of the porous plate, and has higher rigidity per unit area than the porous plate. According to the above configuration, the vibration of the perforated plate with respect to the casing is strongly suppressed by the support, and thus an excellent sound absorbing effect can be exhibited.

  The above sound absorbing structure is further configured as follows. That is, the support is thicker than the perforated plate. According to the above configuration, the rigidity per unit area of the support can be made higher than that of the porous plate with a simple configuration.

  The above sound absorbing structure is further configured as follows. That is, the support has a multilayer structure. According to the above configuration, the rigidity per unit area of the support can be made higher than that of the porous plate with a simple configuration.

  Embodiments of the present invention will be described below.

  First, please refer to FIG. FIG. 1 is a partially cutaway perspective view of a sound absorbing structure according to an embodiment of the present invention. As shown in this figure, the sound absorbing structure 1 according to this embodiment includes a housing 4 having a surface plate 3 in which a large number of holes 2 are formed, and the housing 4 in the normal direction of the surface plate 3. It is comprised from the perforated plate 5 which partitions internal space, and the square tube 6 as a support body which supports the perforated plate 5 with respect to said housing | casing 4. FIG. The square tube 6 fixes and supports the porous plate 5 with respect to the housing 4 in the normal direction and in-plane direction of the porous plate 5, and the rigidity per unit area is higher than that of the porous plate 5. Is also set high.

  Here, for convenience of explanation, a normal direction, a longitudinal direction, and a short direction are defined in FIG. That is, the “normal direction” means the normal direction of the surface plate 3 provided in the sound absorbing structure 1. The “longitudinal direction” and the “short direction” are both perpendicular to the “normal direction”, and the “longitudinal direction” and the “short direction” are orthogonal to each other.

  Hereafter, each component of said sound-absorbing structure 1 is demonstrated in detail.

  The casing 4 is a hollow rectangular parallelepiped, and the size thereof is about 2000 mm in the longitudinal direction, about 500 mm in the lateral direction, and about 100 mm in the normal direction. The housing 4 is made of a metal plate such as an aluminum plate, a stainless steel plate, or a high weather-resistant plated steel plate, and has a thickness of about 1 to 2 mm. The numerous holes 2 formed in the surface plate 3 are formed by, for example, punching, and the hole diameter is approximately 0.3 to 3.0 mm, and the aperture ratio is approximately 10% or less.

  The perforated plate 5 and the square tube 6 constitute a plurality of sound absorbing units 7 in the housing 4. In other words, the sound absorbing unit 7 includes the perforated plate 5 and the square tube 6. Six sound absorbing units 7 are accommodated in the housing 4, and three are arranged in the longitudinal direction and two are arranged in the short direction in the figure. Hereinafter, the configuration of the sound absorbing unit 7 will be described in more detail.

As described above, the sound absorbing unit 7 includes the porous plate 5 that partitions the internal space of the housing 4 in the normal direction of the surface plate 3 and the square tube 6 that supports the porous plate 5 with respect to the housing 4. The perforated plate 5 is configured to be substantially parallel to the surface plate 3. The square tube 6 extends in the normal direction in the figure, and two bent portions 8 are formed that project outward from the square tube 6 in the middle of the extending direction. Then, the outer peripheral edge portion 9 of the perforated plate 5 is inserted into each bent portion 8, and the outer peripheral edge portion 9 is accommodated in the bent portion 8 and pressed against the bent portion 8 by a stapler. By being fixed together, the porous plate 5 is fixedly supported with respect to the square tube 6 in the normal direction and in-plane direction of the porous plate 5. On the other hand, the sound absorbing unit 7 is accommodated in the normal direction, the longitudinal direction, and the short direction with respect to the casing 4 without any play. It is supported so that relative movement is impossible. With this configuration, the square tube 6 can be said to fix and support the porous plate 5 with respect to the housing 4 in the normal direction and in-plane direction of the porous plate 5.

  The perforated plate 5 is made of, for example, aluminum or other metal foil, and has a thickness of about 0.1 mm, and a large number of through-holes 10 of about 0.05 to 0.15 mm are formed. The aperture ratio of the porous plate 5 is approximately 0.1 to 1.0%. Reference is now made to FIG. FIG. 2 is an enlarged cross-sectional view of the perforated plate. As shown in the figure, the perforated plate 5 is embossed in a zigzag shape in a plan view, and the aluminum foil is locally cleaved in the through hole 10 during the embossing. Is formed. The above-mentioned “thickness of the porous plate 5” is defined as follows when the surface becomes uneven by embossing as in this embodiment. That is, the “thickness of the perforated plate 5” is not a thickness that includes all of the irregularities indicated by the symbol T in this figure, but a thickness of the porous plate 5 that can be imagined on the assumption that there are no irregularities indicated by the symbol t. Means. In other words, the “thickness of the perforated plate 5” is defined as the thickness of the perforated plate 5 just before embossing.

  On the other hand, the square tube 6 is made of, for example, aluminum or other metal foil, and the thickness thereof is set to be thicker than that of the porous plate 5. That is, in this embodiment, the thickness of the square tube 6 is approximately 0.2 mm. Thereby, the rigidity per unit area of the square tube 6 is higher than that of the porous plate 5 described above. Unlike the perforated plate 5, the rectangular tube 6 has a non-porous shape in which the through hole 10 is not formed.

  Please refer to FIG. 1 again. In the present embodiment, each of the bent portions 8 is disposed at two locations in the extending direction of the square tube 6. Therefore, for convenience of explanation to be described later, the bent portion 8 closer to the surface plate 3 out of the two bent portions 8 is referred to as a first bent portion 11 and the other is referred to as a second bent portion 12. The porous plate 5 supported by the first bent portion 11 is referred to as a first porous plate 13, and the porous plate 5 supported by the second bent portion 12 is referred to as a second porous plate 14. Further, a portion of the square tube 6 that is closer to the surface plate 3 than the first bent portion 11 is positioned between the first square tube portion 15 and the first bent portion 11 and the second bent portion 12. The portion is referred to as a second rectangular tube portion 16, and the portion on the opposite side across the second rectangular tube portion 16 and the second bent portion 12 is referred to as a third triangular tube portion 17.

  Hereinafter, the first test for confirming the technical effect of the sound absorbing structure 1 according to the present embodiment will be described in detail. Please refer to FIG. 3 and FIG. FIG. 3 is a graph showing test results of the first test for confirming the technical effect of the sound absorbing structure. FIG. 4 is an explanatory diagram of test conditions of a first test for confirming the technical effect of the sound absorbing structure.

  In the graph shown in FIG. 3, the horizontal axis represents the output frequency of the sound source, and the vertical axis represents the sound absorption coefficient (reverberation room method sound absorption coefficient). The “resin frame” in the figure is the configuration disclosed in FIG. 2 of Patent Document 1 described above, that is, the perforated plate is movable relative to the box member in the in-plane direction of the perforated plate. Corresponding to a sound-absorbing structure that is supported so as not to be relatively movable in the normal direction of the perforated plate. Similarly, the “four-way rail” in the figure is the configuration according to the above embodiment, that is, the perforated plate 5 is in any direction with respect to the casing 4 (that is, the method of the perforated plate 5). It corresponds to the sound absorbing structure 1 having a configuration in which it is fixedly supported (in the linear direction and in-plane direction). On the other hand, the “two-way rail” in the figure corresponds to a sound absorbing structure having a configuration different from the configuration of the “four-way rail” as follows. Reference is now made to FIG. As shown in FIG. 1A, in the configuration of the “four-way rail”, the bent portion 8 surrounds the perforated plate 5 over the entire circumference. On the other hand, as shown in FIG. 2B, in the configuration of the “two-way rail”, the bent portion 8 does not surround the perforated plate 5 over the entire circumference but faces the perforated plate 5 therebetween. It is formed only in portions corresponding to a pair of sides. The configuration of the “four-way rail” and the configuration of the “two-way rail” are that the porous plate 5 is fixedly supported with respect to the housing 4 in the normal direction and the in-plane direction of the porous plate 5. The same.

  Please refer to FIG. 3 again. According to this figure, the configuration of the “4-way rail” and the “2-way rail” exhibits an excellent sound absorbing effect in a wide range of output frequencies of 200 to 4000 Hz compared to the configuration of the above-mentioned Patent Document 1. You can see that This can be considered as follows.

  That is, the former configuration and the latter configuration are different in that the porous plate 5 is fixedly supported with respect to the casing 4 (or box member) in the normal direction and in-plane direction of the porous plate 5. In the former configuration, the porous plate 5 is fixedly supported with respect to the housing 4 in the normal direction and the in-plane direction of the porous plate 5. When the perforated plate 5 is fixedly supported in the normal direction and in-plane direction of the perforated plate 5 with respect to the casing 4, when air enters the hole 2 formed in the perforated plate 5, the perforated plate 5 5 is difficult to vibrate, and thereby the chance of friction between the inner peripheral surface of the hole 2 and the air is not impaired. The friction between the inner peripheral surface of the hole 2 and the air contributes most to the sound absorption effect. Therefore, it is considered that the former configuration can exhibit an excellent sound absorbing effect because the vibration of the perforated plate 5 is suppressed.

  In addition, the said 1st test can also be considered as follows from another viewpoint. That is, the support frame of Patent Document 1 is much higher in rigidity than the rectangular tube 6, but as described above, the perforated plate is fixedly supported with respect to the box member in the normal direction and the in-plane direction of the perforated plate. If there is no technical matter that is a prerequisite, it is considered that the rigidity of the support frame hardly affects the sound absorption effect.

  Next, a first modification of the above embodiment will be described. Please refer to FIG. FIG. 5 is a partially cutaway perspective view of the sound absorbing structure according to the first modification. Here, this modification will be described mainly with respect to differences from the above embodiment, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  In the above embodiment, the rectangular tube 6 has a single layer structure (see also FIG. 1), and the rigidity per unit area is higher than that of the porous plate 5 by setting the thickness to be thicker than the porous plate 5. I am doing so. On the other hand, the square tube 6 according to this modification has a multilayer structure of aluminum foil. Specifically, the square tube 6 has a two-layer structure of aluminum foil in this modification, and the thickness of each layer is the same as the thickness of the porous plate 5, for example. Thus, the square tube 6 according to the present modification employs a multilayer structure so that the rigidity per unit area is higher than that of the porous plate 5.

  Next, a second test for verifying the technical effect of the sound absorbing structure 1 according to the embodiment and the modification from another viewpoint will be described. See FIG. FIG. 6 is a graph showing test results of the second test for confirming the technical effect of the sound absorbing structure.

  In the graph shown in FIG. 6, the horizontal axis and the vertical axis are the same as the graph shown in FIG. “Folded side surface single” in the drawing is a comparative example, and means a sound absorbing structure having a configuration in which the thickness of the square tube 6 is the same as that of the porous plate 5 in the configuration shown in FIG. In addition, “folding only on the lower side of the bent side surface” in the drawing is an example, and in the configuration shown in FIG. 5, only the first triangular cylinder portion 17 of the square cylinder 6 has a multilayer structure (two-layer structure). On the other hand, the first rectangular tube portion 15 and the second rectangular tube portion 16 mean the sound absorbing structure 1 having a configuration that does not employ a multilayer structure. In this embodiment, specifically, a lead sheet with an adhesive having a thickness of 0.5 mm with respect to the third triangular cylinder portion 17 which is a portion adopting a multilayer structure (here, a lead sheet is used instead of an aluminum foil). The selection was made for convenience in conducting the experiment.) Further, “folded side upper middle lower double” in the drawing is an example, and the configuration shown in FIG. 5, that is, the first rectangular tube portion 15 and the second rectangular tube portion of the rectangular tube 6. The sound absorbing structure 1 having a configuration adopting a multilayer structure (double structure) for any of the sixteenth and third triangular cylinder portions 17 is meant. In this embodiment, specifically, with the adhesive having a thickness of 0.5 mm with respect to the first rectangular tube portion 15, the second rectangular tube portion 16, and the first triangular tube portion 17, which are portions adopting a multilayer structure. A lead sheet was attached in the same manner as described above.

  According to this figure, if the rigidity per unit area of the square tube 6 is set to be higher than that of the perforated plate 5 by adopting a multilayer structure with respect to the square tube 6, an excellent result in terms of the sound absorption effect is obtained. It turns out that it is obtained. Also, according to the comparison between “Folded side bottom double only” and “Folded side upper middle lower double” in the figure, it can be seen that the former and the latter have almost the same results. This is a configuration in which a multi-layer structure is adopted for the first triangular tube portion 17 of the square tube 6 but a multi-layer structure is adopted in the first square tube portion 15 and the second square tube portion 16 other than the first triangular tube portion 17. This means that it is advantageous in terms of sound absorption effect. And this tendency can be considered as follows. That is, as shown in FIG. 5, it can be said that the third triangular tube portion 17 is easy to vibrate because it has a larger area and is more easily bent than the first square tube portion 15 and the second square tube portion 16. Therefore, it is considered beneficial to preferentially apply the multilayer structure having the vibration suppressing effect to the portion (the third triangular tube portion 17) that is most likely to vibrate.

  Next, a second modification of the above embodiment will be described. Please refer to FIG. FIG. 7 is a partially cutaway perspective view of the sound absorbing structure according to the second modification. Here, this modification will be described mainly with respect to differences from the above embodiment, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  The sound absorbing unit 7 according to the present modification is a large box 18 that opens in a direction away from the surface plate 3 in place of the configuration of the above-described embodiment formed by a combination of the perforated plate 5 and the square tube 6 as shown in FIG. And a child box 19 that is accommodated in the large box 18 and opens in the same direction away from the surface plate 3. Both the large box 18 and the child box 19 are formed by bending aluminum foil. The large box 18 includes a bottom surface portion 20 corresponding to the first perforated plate 13 and a square tube portion 21 extending along the normal direction. Similarly, the child box 19 includes a bottom surface portion 22 corresponding to the second perforated plate 14 and a rectangular tube portion 23 extending along the normal direction. A large number of through holes 10 are formed in the bottom surface portion 20 and the bottom surface portion 22 in the same manner as the porous plate 5 described above. The bottom surface portion 20 is separated from the surface plate 3 as much as the first porous plate 13 according to the embodiment, and the bottom surface portion 22 is also separated from the surface plate 3 as much as the second porous plate 14 according to the embodiment. Is done.

  The rectangular tube portion 21 is in a relation to be covered with the rectangular tube portion 23. The rectangular tube portion 21 and the rectangular tube portion 23 are fixed to the housing 4, thereby functioning as a support for supporting the bottom surface portion 20 and the rectangular tube portion 21 as a porous plate with respect to the housing 4. Demonstrate. In other words, the rectangular tube portion 21 and the rectangular tube portion 23 can be said to be constituent members corresponding to the rectangular tube 6 according to the above embodiment in that the bottom surface portion 20 and the bottom surface portion 22 are supported with respect to the housing 4. .

  An aluminum foil 24 having a thickness of approximately 0.1 mm is pasted on the outer periphery of the rectangular tube portion 21 by a stapler. As a result, the square tube portion 21 and the square tube portion 23 that support the bottom surface portion 20 and the bottom surface portion 22 with respect to the housing 4 have higher rigidity per unit area than the bottom surface portion 20 and the bottom surface portion 22, respectively. Thus, vibrations of the bottom surface portion 20 and the bottom surface portion 22 are suppressed.

  As described above, since the rectangular tube portion 21 has a relationship of covering the rectangular tube portion 23, the rectangular tube portion 23 that supports the bottom surface portion 22 with respect to the housing 4 has a rigidity per unit area. Becomes higher than the bottom surface portion 22. Therefore, in this modification, even if it is the structure where the aluminum foil 24 is not affixed, it can be said that the vibration is suppressed at least regarding the bottom face part 22.

  Next, a third modification of the above embodiment will be described. Please refer to FIG. FIG. 8 is a partially cutaway perspective view of a sound absorbing structure according to a third modification. Here, the present modification will be described mainly with respect to differences from the second modification, and other overlapping description will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  The sound absorbing unit 7 according to the present modification includes an M-shaped box 25 having an M-shaped cross section instead of the large box 18 according to the second modified example. The M-shaped box 25 is formed by bending aluminum foil. The M-shaped box 25 includes a bottom surface portion 26 corresponding to the first perforated plate 13 and a connecting portion 27 extending from the outer peripheral edge of the bottom surface portion 26 toward the surface plate 3 and reaching the surface plate 3. And a rectangular tube portion 28 that is bent 180 degrees from the front end of the connecting portion 27 and extends in a direction away from the surface plate 3.

  The rectangular tube portion 28 is slightly covered with the rectangular tube portion 23. The rectangular tube portion 23 is fixed to the housing 4, and the rectangular tube portion 28 is fixed to the rectangular tube portion 23 by a stapler, so that the rectangular tube portion 28 is a porous plate with respect to the housing 4. A function as a support for supporting the bottom surface portion 26 is exhibited. In other words, the square tube portion 28 can be said to be a component corresponding to the square tube 6 according to the above embodiment in that the bottom surface portion 26 is supported with respect to the housing 4.

  Then, an aluminum foil 24 having a thickness of approximately 0.1 mm is attached to the outer periphery of the square tube portion 28 and the square tube portion 23 by a stapler. As a result, the square tube portion 28 and the square tube portion 23 that support the bottom surface portion 26 and the bottom surface portion 22 with respect to the housing 4 have higher rigidity per unit area than the bottom surface portion 26 and the bottom surface portion 22, respectively. Thus, the vibration of the bottom surface portion 26 and the bottom surface portion 22 is suppressed.

  Next, a fourth modification of the above embodiment will be described. See FIG. FIG. 9 is a partially cutaway perspective view of a sound absorbing structure according to a fourth modification. Here, the present modification will be described mainly with respect to differences from the third modification, and other overlapping description will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  The sound absorbing unit 7 according to this modification includes an M-shaped box 29 having an M-shaped cross section instead of the child box 19 according to the third modified example. That is, the sound absorbing unit 7 according to this modification is configured to include the M-shaped box 25 and the M-shaped box 29. Hereinafter, for convenience of explanation, the M-shaped box 25 disposed on the surface plate 3 side is the first M-shaped box 25, and the M-shaped character disposed on the opposite side across the surface plate 3 and the first M-shaped box 25. The box 29 will be referred to as a second M-shaped box 29. The second M-shaped box 29 is formed by bending aluminum foil. The second M-shaped box 29 includes a bottom surface portion 30 corresponding to the second perforated plate 14, a connection portion 31 extending from the outer peripheral edge of the bottom surface portion 30 toward the surface plate 3, and the connection portion. And a rectangular tube portion 32 that is bent 180 degrees from the tip of 31 and extends away from the surface plate 3.

  The rectangular tube portion 28 has a partially overlapping relationship with the rectangular tube portion 32. Specifically, the rectangular tube portion 28 is in an overlapping relationship with the portion of the rectangular tube portion 32 that overlaps with the connecting portion 31. And the square cylinder part 32 exhibits the function as a support body which supports the bottom face part 30 as a porous plate with respect to the housing | casing 4 because the square cylinder part 32 is fixed with respect to the housing | casing 4. FIG. In other words, the rectangular tube portion 32 can be said to be a component corresponding to the rectangular tube 6 according to the above-described embodiment in that the bottom surface portion 30 is supported with respect to the housing 4.

  Then, an aluminum foil 24 having a thickness of approximately 0.1 mm is pasted on the outer periphery of the rectangular tube portion 28 and the rectangular tube portion 32 by a stapler. As a result, the square tube portion 28 and the square tube portion 32 that support the bottom surface portion 26 and the bottom surface portion 30 with respect to the housing 4 have higher rigidity per unit area than the bottom surface portion 26 and the bottom surface portion 30, respectively. Thus, the vibration of the bottom surface portion 26 and the bottom surface portion 30 is suppressed.

  Next, a fifth modification of the above embodiment will be described. Please refer to FIG. FIG. 10 is a partially cutaway perspective view of the sound absorbing structure according to the fifth modification. Here, the present modification will be described mainly with respect to differences from the fourth modification, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  The sound absorbing unit 7 according to this modification is different from the sound absorbing unit 7 according to the fourth modification in the following points. That is, in the sound absorbing unit 7 according to the fourth modified example, as shown in FIG. 9, the rectangular tube portion 28 is in a relationship of covering the rectangular tube portion 32 from the outside. On the other hand, in the sound absorbing unit 7 according to this modification, as shown in FIG. 10, the rectangular tube portion 28 is not completely covered with the rectangular tube portion 32 from the outside. Specifically, a part of the rectangular tube portion 28 is located on the inner side of the rectangular tube portion 32, more specifically, on the inner side of the connecting portion 31 that connects the rectangular tube portion 32 and the bottom surface portion 30, And it is set as the relationship contact | abutted with respect to the bottom face part 30. A part of the rectangular tube portion 28 located inside the connecting portion 31 is fixed to the connecting portion 31 by a stapler. In this sense, the rectangular tube portion 28 according to the present modification, like the rectangular tube portion 28 according to the fourth modification, functions as a support that supports the bottom surface portion 26 as a porous plate with respect to the housing 4. Demonstrate. In other words, the rectangular tube portion 28 according to the present modification example relates to the above-described embodiment in that the bottom surface portion 26 is supported with respect to the housing 4 in the same manner as the rectangular tube portion 28 according to the fourth modification example. It can be said that it is a component corresponding to the square tube 6.

  The aluminum foil 24 is attached to the outer periphery of the rectangular tube portion 28 and the rectangular tube portion 32, thereby suppressing the vibration of the bottom surface portion 26 and the bottom surface portion 30. This is the same as the fourth modification.

  Next, a sixth modification of the above embodiment will be described. Please refer to FIG. FIG. 11 is a partially cutaway perspective view of the sound absorbing structure according to the sixth modification. Here, the present modification will be described with a focus on differences from the first modification, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

In the first modified example, as shown in FIG. 5, the perforated plate 5 is press-engaged and fixed to the bent portion 8 by the stapler in a state where the outer peripheral edge portion 9 is accommodated in the bent portion 8. Thus, the porous plate 5 is fixedly supported with respect to the square tube 6 in the normal direction and in-plane direction of the porous plate 5. On the other hand, in this modified example, as shown in FIG. 11, instead of forming the bent portion 8 in the square tube 6, a bent portion 34 is provided on the outer peripheral edge of the perforated plate 5, and the bent portion 34 is replaced with the square tube. by pressing engagement fixed by stapler respect 6, the perforated plate 5 is fixedly supported in the normal direction and the plane direction of the porous plate 5 with respect to the rectangular tube 6.

  In the present modification, as in the first modification, the square tube 6 adopts a multilayer structure so that the rigidity per unit area is higher than that of the porous plate 5. Instead of applying a multilayer structure to the square tube 6, the thickness of the square tube 6 may be set thicker than the perforated plate 5 as in the above embodiment.

  Next, a seventh modification of the above embodiment will be described. Please refer to FIG. FIG. 12 is a partially cutaway perspective view of a sound absorbing structure according to a seventh modification. Here, the present modification will be described mainly with respect to differences from the fourth modification, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  The sound absorbing unit 7 according to the fourth modified example is configured to include a first M-shaped box 25 and a second M-shaped box 29 as shown in FIG. On the other hand, as shown in FIG. 12, the sound absorbing unit 7 according to this modification has a first Z-shaped member 35 having a Z-shaped cross section, and the opposite side across the surface plate 3 and the first Z-shaped member 35. And a second Z-shaped member 36 having a Z-shaped cross section disposed in the main structure. The first Z-shaped member 35 and the second Z-shaped member 36 are both formed by bending aluminum foil. The first Z-shaped member 35 is based on the contact with the surface plate 3, and extends from the surface plate 3 in a direction away from the surface plate 3. A first porous plate portion 38 extending in parallel and corresponding to the first porous plate 13 and a first portion extending from the front end of the first porous plate portion 38 in a direction away from the surface plate 3. And an extending portion 39. Similarly, the second Z-shaped member 36 also extends in a direction away from the surface plate 3, and extends from the second extension portion 40 in parallel with the surface plate 3. A second perforated plate portion 41 corresponding to the hole plate 14; and a second extending portion 42 extending from the front end of the second perforated plate portion 41 in a direction away from the surface plate 3. Become.

The first extension part 37 and the second extension part 40 are in a partially overlapping relationship. In this overlapping part, the first extension part 37 and the second extension part 40 are pressed against each other by a stapler. It is if fixed. Similarly, the first extension portion 39 and the second extension portion 42 also have a partially overlapping relationship. In this overlapping portion, the first extension portion 39 and the second extension portion 42 are mutually connected by a stapler. Is pressed and fixed. And the 1st extension part 37 and the 2nd extension part 42 are fixed with respect to the housing | casing 4, and the 1st extension part 39 and the 2nd extension part 40 are said 1st extension part 37 and 2nd. These first extending portion 37, first extending portion 39, second extending portion 40, and second extending portion 42 are fixed to the housing 4 via the extending portion 42, respectively. The function as a support for supporting the first porous plate portion 38 and the second porous plate portion 41 as the porous plate with respect to the casing 4 is exhibited. In other words, the first extending portion 37, the first extending portion 39, the second extending portion 40, and the second extending portion 42 enclose the first porous plate portion 38 and the second porous plate portion 41. It can be said that it is a structural member corresponding to the square tube 6 according to the above embodiment in that it is supported with respect to the body 4.

  The aluminum foil 24 having a thickness of approximately 0.1 mm is pasted on the second extending portion 40, the first extending portion 39, and the second extending portion 42 by a stapler. Thereby, the 2nd extension part 40, the 1st extension part 39, and the 2nd extension part 42 which support the 1st porous board part 38 and the 2nd porous board part 41 with respect to the housing | casing 4 are unit. The rigidity per area is higher than that of the first perforated plate portion 38 and the second perforated plate portion 41, so that the vibration of the first perforated plate portion 38 and the second perforated plate portion 41 is suppressed. It has become.

  Next, an eighth modification of the above embodiment will be described. See FIG. FIG. 13 is a partially cutaway perspective view of a sound absorbing structure according to an eighth modification. Here, this modification will be described mainly with respect to differences from the above embodiment, and other overlapping descriptions will be omitted. Moreover, the same code | symbol is used about a corresponding member.

  A sound absorbing structure 1 according to this modification includes a housing 4 having a surface plate 3 in which a large number of holes 2 are formed, and a perforated plate 5 that partitions the internal space of the housing 4 in the normal direction of the surface plate 3. And a partition wall 43 as a support for supporting the porous plate 5 with respect to the casing 4. The partition wall 43 fixes and supports the porous plate 5 with respect to the housing 4 in the normal direction and the in-plane direction of the porous plate 5, and the rigidity per unit area is higher than that of the porous plate 5. Is also set high. Hereinafter, the configuration of the sound absorbing structure 1 will be described in more detail.

In this modification, the porous plate 5 has an area substantially the same as that of the surface plate 3, and a plurality of porous plates 5 are arranged in parallel to the surface plate 3. The partition wall 43 has a multiple structure, and the details of the multiple structure are as in the first modification to the above embodiment. The partition wall 43 is provided with a bent portion 44 for fixing the partition wall 43 to the perforated plate 5, and the bent portion 44 is press-engaged and fixed to the perforated plate 5 by a stapler. The wall 43 is configured to fix and support the porous plate 5 with respect to the housing 4 in the normal direction and in-plane direction of the porous plate 5.

(Summary)
As described above, the sound absorbing structure 1 according to the embodiment shown in FIG. 1 is configured as follows. That is, with respect to the housing 4 provided with a housing 4 having a surface plate 3 in which a large number of holes 2 are formed, a porous plate 5 that partitions the internal space of the housing 4 in the normal direction of the surface plate 3, and A square tube 6 (support) that supports the porous plate 5. The square tube 6 fixes and supports the porous plate 5 in the normal direction and in-plane direction of the porous plate 5 with respect to the casing 4 and has higher rigidity per unit area than the porous plate 5. According to the above configuration, the vibration of the perforated plate 5 with respect to the housing 4 is strongly suppressed by the square tube 6, so that an excellent sound absorbing effect can be exhibited.

  The sound absorbing structure 1 is further configured as follows. That is, the square tube 6 is thicker than the perforated plate 5. According to the above configuration, the rigidity per unit area of the square tube 6 can be made higher than that of the porous plate 5 with a simple configuration.

  The sound absorbing structure 1 is further configured as follows. That is, the square tube 6 has a multilayer structure. According to the above configuration, the rigidity per unit area of the square tube 6 can be made higher than that of the porous plate 5 with a simple configuration.

  Although the preferred embodiment of the present invention has been described above, the above embodiment can be modified as follows.

  That is, it is conceivable to use, for example, an adhesive or an adhesive tape instead of the illustrated stapler when fixing the components of the sound absorbing structure 1.

  Further, as a means for forming the through hole 10 in the perforated plate 5, a punching process may be used instead of the illustrated embossing process.

  Moreover, each component which exhibits the function as a support body can consider the structure made into a porous shape instead of a non-porous shape.

  In addition, each component that functions as a support can be provided with, for example, ribs or the like as appropriate, instead of improving the rigidity by appropriately setting the thickness or adopting a multilayer structure. Improvements can also be considered.

For example, as shown in FIG. 1, a bent portion 8 that should be drawn in a single state by being originally pressed and fixed is avoided to be drawn in a single manner in order to facilitate an understanding of the structure. I will add that. The same applies to FIGS. 5 and 7 to 13. That is, for example, in FIG. 13, the partition wall 43 is drawn with emphasis on a multilayer structure. However, in reality, the partition wall 43 has a multilayer structure with no gaps, and is therefore single.

  “Rigidity per unit area” in the present specification also contributes to the overlapping relationship between the connecting portion 27 and the rectangular tube portion 28 as shown in FIG. 8, for example. That is, in this figure, the connecting portion 27 that fixes and supports the bottom surface portion 26 with respect to the housing 4 in the normal direction and in-plane direction of the bottom surface portion 26 may be configured such that the aluminum foil 24 is omitted. Due to the overlapping relationship with the rectangular tube portion 28, the rigidity is higher than that of the bottom surface portion 26. In this sense, the connecting portion 27, the square tube portion 28, and the square tube portion 23, which function as a support, have a unit area as a whole due to the overlapping relationship between the connecting portion 27 and the square tube portion 28. It can be said that the rigidity is higher than the bottom surface portion 26 and the bottom surface portion 22 as a perforated plate.

Partially cutaway perspective view of a sound absorbing structure according to an embodiment of the present invention Cross-sectional enlarged view of perforated plate Graph showing the test results of the first test to confirm the technical effect of the sound absorbing structure Explanatory drawing of the test conditions of the first test to confirm the technical effect of the sound absorbing structure Partially cutaway perspective view of the sound absorbing structure according to the first modification. Graph showing the test results of the second test to confirm the technical effect of the sound absorbing structure Partially cutaway perspective view of a sound absorbing structure according to a second modification. Partially cutaway perspective view of a sound absorbing structure according to a third modification. Partially cutaway perspective view of a sound absorbing structure according to a fourth modification. Partially cutaway perspective view of a sound absorbing structure according to a fifth modification Partially cutaway perspective view of sound absorbing structure according to sixth modification. Partially cutaway perspective view of a sound absorbing structure according to a seventh modified example Partially cutaway perspective view of a sound absorbing structure according to an eighth modification

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sound absorption structure 2 Hole 3 Surface plate 4 Case 5 Perforated plate 6 Square cylinder 7 Sound absorption unit 8 Bending part

Claims (3)

A housing including a surface plate in which a large number of holes are formed;
A perforated plate that partitions the internal space of the housing in the normal direction of the surface plate;
The porous plate is fixedly supported with respect to the housing in the normal direction and in-plane direction of the porous plate , and a support having a higher rigidity per unit area than the porous plate ,
With
The support has a V-shaped bent portion that extends in the normal direction of the perforated plate and protrudes outward of the support in the middle of the extending direction;
With the outer peripheral edge portion of the perforated plate inserted into the bent portion, the bent portion that opens in a V shape is pressed against the bent portion from the outside of the bent portion. By being engaged and fixed, the perforated plate is fixedly supported with respect to the support in the normal direction and in-plane direction of the perforated plate . The sound absorbing structure according to claim 1,
The sound absorbing structure, wherein the support is thicker than the perforated plate. The sound absorbing structure according to claim 1 or 2,
The sound absorbing structure according to claim 1, wherein the support has a multilayer structure.

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