Sound-absorbing member

Abstract

The purpose of the present invention is to provide a sound-absorbing member in which the thickness between a front surface section and a rear surface section is reduced on the basis of a novel diffraction principle instead of the conventional straight-line principle. This sound-absorbing member (1) is provided with: a sound-source-side front surface section (2) having an X-Y plane; and a rear surface section (4) disposed on the front surface section (2) with a rear air layer (3) having a thickness in the Z direction therebetween. A plurality of slits (5) communicating with the rear air layer (3) are provided in the front surface section (2) at a prescribed length and a prescribed pitch, and a ventilation chamber (6) for guiding and accommodating sound diffracted waves incident from the slits (5) is provided on the X-Y plane so as to have a prescribed thickness in the Z direction.

Description

Technical Field

[0001] The present invention relates to a sound absorbing component used in a soundproof wall of a highway, an inner wall of an indoor passage, etc. Background Art

[0002] As a conventional sound absorbing component, there is a sound absorbing component described in Japanese Patent Publication No. 2022-84524 (Patent Document 1). This conventional sound absorbing component is used for a sound absorbing wall installed beside a road, and has a sound absorbing member inside a box-shaped plate body composed of a front part, a back part, and a side part with holes formed by a louver or the like.

[0003] The above-mentioned conventional sound absorption technology uses fibers, foam materials, films, etc. as materials, and uses heat energy conversion methods such as resonance, vibration, friction, etc. as structures. In addition, the prior art uses this principle to make the incoming sound move straight from the front part to the back part side to solve the problem.

[0004] Therefore, conventional sound absorbing components are sound absorbing components whose box-shaped panel bodies are thicker. When installing the sound absorbing panels in walls and ceilings that are not subjected to wind loads, such as conference rooms, machine rooms, gymnasiums, arenas, public passages, and air conditioning equipment, as installation locations, thin sound absorbing panels are desired.

[0005] However, it is difficult to achieve thinning with the technology described in the conventional Patent Document 1.

[0006] On the other hand, as a technology for achieving thinning, there is a technology described in Japanese Patent Publication No. 2003-108145 (Patent Document 2). This sound insulation component is configured with two porous metal plates at appropriate intervals from the panel portion of the profile, and exerts a sound insulation effect through the Helmholtz resonance principle and the viscosity attenuation principle to achieve thinness and lightness.

[0007] However, the thickness of the profile described in Patent Document 2 is very thick, so there is a limit to thinning. In addition, if the air layer between the porous metal plate and the panel portion is not made thicker, sufficient sound insulation effect cannot be exerted.

[0008] [Prior art literature]

[0009] [Patent Document]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2022-84524

[0011] [Patent Document 2] Japanese Patent Application Publication No. 2003-108145. Summary of the invention

[0012] [Problems to be solved by the invention]

[0013] The technology described in Patent Documents 1 and 2 is based on the principle of obtaining a sound absorbing effect by making incoming sound travel straight from the front portion to the back portion side. Therefore, a thick rear air layer is required, and there is a limit to thinning.

[0014] Therefore, an object of the present invention is to provide a sound absorbing member which is not based on the conventional straight-line principle but based on a new diffraction principle and has a reduced thickness between the front portion and the back portion.

[0015] [Methods for solving the problem]

[0016] In order to achieve the above object, the present invention adopts the following method. That is, the sound absorbing component of the present invention has: a front face portion on the sound source side having an XY plane; and a rear face portion arranged on the front face portion with a rear air layer having a thickness in the Z direction interposed therebetween; a plurality of slits communicating with the rear air layer are provided at a predetermined length and predetermined intervals in the front face portion, and a ventilation chamber is provided on the XY plane with a predetermined thickness in the Z direction to guide and contain diffracted waves of sound incident from the slits.

[0017] Preferably, the ventilation chamber is divided into a plurality of parts in the Y direction and is continuous in the X direction, and the slit is linear and intersects the X direction at an angle of 45 to 135 degrees.

[0018] It is preferred that the ventilation chamber be provided in multiple layers in the Z direction.

[0019] The front portion is preferably formed of any one of corrugated paper, metal material, or synthetic resin material.

[0020] Preferably, a sound absorbing material is accommodated in the ventilation chamber.

[0021] [Advantages and positive effects of the present invention]

[0022] The present invention uses the principle of sound diffraction to achieve an effect of being able to form a thinner structure compared to conventional linear configurations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view showing a sound absorbing member according to an embodiment of the present invention.

[0024] Figure 2 yes Figure 1 Cross-sectional views of various illustrative sound absorbing components.

[0025] Figure 3 It is a cross-sectional view of the front part made of corrugated paper.

[0026] Figure 4 It is a cross-sectional view of the front part made of aluminum profiles.

[0027] Figure 5 It is a various cross-sectional view of the front part consisting of composite overlapping panels.

[0028] Figure 6 It is a perspective view of the front part for explaining the diffraction principle of the present invention.

[0029] Figure 7 This is a diagram illustrating the principle of diffraction.

[0030] Figure 8 It is the front view of the first specimen.

[0031] Fig. 9 is a cross-sectional view of the first specimen.

[0032] Fig.10 It is a graph showing the sound absorption measurement results of the first test piece.

[0033] Fig.11 It is a graph showing the sound absorption measurement results of the first test piece.

[0034] Fig.12 It is the front view of the second specimen.

[0035] Fig.13 It is a graph showing the sound absorption measurement results of the second test piece.

[0036] Fig.14 It is a graph showing the sound absorption measurement results of the second test piece.

[0037] Fig.15 is a cross-sectional view of the third specimen.

[0038] Fig.16 It is a graph showing the sound absorption measurement results of the third test piece.

[0039] Fig.17 It is a graph showing the sound absorption measurement results of the third test piece.

[0040] Fig.18 It is the front view of the fourth specimen.

[0041] Fig.19 It is a graph showing the sound absorption measurement results of the fourth test piece.

[0042] Fig. 20 It is a graph showing the sound absorption measurement results of the fourth test piece.

[0043] Fig.21 is a cross-sectional view of the fifth test piece.

[0044] Fig. 22 It is a graph showing the sound absorption measurement results of the fifth test piece.

[0045] Fig.23It is a graph showing the sound absorption measurement results of the fifth test piece.

[0046] Fig.24 is a cross-sectional view of the sixth specimen.

[0047] Fig.25 It is a graph showing the sound absorption measurement results of the sixth test piece.

[0048] Fig.26 It is a graph showing the sound absorption measurement results of the sixth test piece.

[0049] Fig. 27 It is a front view and a cross-sectional view showing a sound absorbing member according to another embodiment of the present invention.

[0050] Fig.28 It is a front view and a cross-sectional view showing a sound absorbing member and its components according to another embodiment of the present invention.

[0051] Fig.29 It is a front view and a cross-sectional view showing a sound absorbing member and its components according to another embodiment of the present invention.

[0052] Fig.30 It is a cross-sectional view showing the front part of another embodiment of the present invention.

[0053] Fig.31 It is a perspective view of a flat aluminum plate constituting another embodiment of the present invention.

[0054] Fig.32 Yes Fig.31 A three-dimensional view of the front part formed by bending an aluminum plate.

[0055] Fig.33 yes Fig.32 A back side perspective view of the front piece.

[0056] Fig.34 Yes Fig.32 A perspective view of the sound absorbing component of the front piece is shown.

[0057] Fig.35 yes Fig.34 An enlarged cross-sectional view of section A.

[0058] Fig.36 is a cross-sectional view of a sound absorbing component having an aluminum frame.

[0059] Fig.37 It is a cross-sectional view of the sound absorbing component of the rear part which is composed of zinc iron plate.

[0060] Fig.38 It is a front view of a spandrel-type sound absorbing component.

[0061] Fig.39 yes Fig.38 A cross-sectional view of a sound absorbing component.

[0062] Fig.40 (a) is the front view of the seventh test piece, and (b) is the cross-sectional view.

[0063] Fig.41 It is a graph showing the sound absorption measurement results of the seventh test piece.

[0064] Fig.42 It is a graph showing the sound absorption measurement results of the seventh test piece.

[0065] Fig.43 (a) is the front view of the eighth test piece, and (b) is the cross-sectional view.

[0066] Fig.44 It is a graph showing the sound absorption measurement results of the eighth test piece.

[0067] Fig.45 It is a graph showing the sound absorption measurement results of the eighth test piece.

[0068] Fig.46 (a) is the front view of the ninth test piece, and (b) is the cross-sectional view.

[0069] Fig.47 It is a graph showing the sound absorption measurement results of the ninth test piece.

[0070] Fig.48 It is a graph showing the sound absorption measurement results of the ninth test piece.

[0071] Fig.49 (a) is a front view of the tenth test piece, and (b) is a cross-sectional view.

[0072] Fig.50 It is a graph showing the sound absorption measurement results of the tenth test piece.

[0073] Fig.51 It is a graph showing the sound absorption measurement results of the tenth test piece.

[0074] Fig.52 (a) is the front view of the eleventh specimen, and (b) is the cross-sectional view.

[0075] Fig.53 This is a graph showing the sound absorption measurement results of the eleventh specimen.

[0076] Fig.54 This is a graph showing the sound absorption measurement results of the eleventh specimen.

[0077] Fig.55 (a) is the front view of the twelfth specimen, and (b) is the cross-sectional view.

[0078] Fig.56 It is a graph showing the sound absorption measurement results of the twelfth test piece.

[0079] Fig.57 It is a graph showing the sound absorption measurement results of the twelfth test piece.

[0080] Fig.58 (a) is the front view of the thirteenth specimen, and (b) is the cross-sectional view.

[0081] Fig.59 This is a graph showing the sound absorption measurement results of the thirteenth test piece.

[0082] Fig.60 This is a graph showing the sound absorption measurement results of the thirteenth test piece.

[0083] Fig.61 (a) is the front view of the fourteenth specimen, and (b) is the cross-sectional view.

[0084] Fig.62 It is a graph showing the sound absorption measurement results of the fourteenth test piece.

[0085] Fig.63 It is a graph showing the sound absorption measurement results of the fourteenth test piece. DETAILED DESCRIPTION

[0086] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0087] Figure 1 It is a front view of a sound absorbing member 1 used in a soundproof wall of a highway, a ceiling wall in a room, and the like.

[0088] Figure 2 It is a cross-sectional view, wherein (a) and (b) of the figure are structures capable of coping with external forces such as wind loads when used outdoors, and (c) of the figure is a cross-sectional structure used indoors in places that are not subjected to wind loads, etc. (such as sound insulation or partitions in the machine room).

[0089] The sound absorbing member 1 includes a front surface portion 2 on the sound source side and a rear surface portion 4 disposed on the front surface portion 2 via a rear air layer 3 .

[0090] In addition, based on Figure 1 The XY coordinates recorded in Figure 2 The YZ coordinates recorded in the figure define the "XYZ direction" used in the present invention. In addition, the X direction is sometimes referred to as the "left-right direction", the Y direction is sometimes referred to as the "up-down direction", and the Z direction is sometimes referred to as the "thickness direction".

[0091] The front part 2 is composed of a plate-like member having an XY plane and a predetermined thickness in the Z direction. The rear part 4 has a rear panel 4a arranged parallel to the front part 2 in the Z direction with the air layer 3 behind it, an upper panel 4b and a lower panel 4c extending from the upper and lower ends of the rear panel 4a toward the front part. The ends of the upper panel 4b and the lower panel 4c are connected to the upper and lower edges of the front part 2.

[0092] like Figure 2 As shown in (a), a convex rib 4d protruding toward the front face 2 is formed at the central portion of the rear panel 4a, and in (b) of the figure, a rib 4e protruding toward the side opposite to the front face 2 is formed at the upper and lower portions of the rear panel 4a, forming a rib structure capable of coping with wind loads. The structure shown in (c) of the figure is for indoor use, so no rib structure is adopted.

[0093] A plurality of slits 5 communicating with the rear air layer 3 are provided at a predetermined length and predetermined intervals on the front portion 2. In addition, a ventilation chamber 6 is provided on the front portion 2 to guide and contain diffracted waves of sound incident from the slits 5. The ventilation chamber 6 has a predetermined thickness along the Z direction on the XY plane. The width of the slit 5 is 0.5 mm or less.

[0094] Figure 3 to Figure 5 Various shapes of the ventilation chamber 6 are shown.

[0095] Figure 3 The front part 2 is shown to be made of corrugated paper. (a) of the figure is a "single-sided corrugated paper" in which a core base paper 8 formed into a wave shape is attached to a liner board 7, and the hollow part of the wave shape forms a ventilation chamber 6. (b) of the figure is a "double-sided corrugated paper" in which a liner board 7 is attached to the top of the corrugation of the single-sided corrugated paper, and the hollow part of the wave shape between the liner boards 7 and 7 forms a ventilation chamber 6. (c) and (d) of the figure are "double-sided double-sided corrugated paper" in which a single-sided corrugated paper is attached to one side of the double-sided corrugated paper. The difference between (c) and (d) lies in the size of the wave spacing of the single-sided corrugated paper. (e) of the figure is a "multiple double-sided corrugated paper" in which a single-sided corrugated paper is attached to one side of the double-sided double-sided corrugated paper.

[0096] The ventilation chamber 6 is divided into a plurality of parts in the Y direction and is continuous in the X direction. In the structures shown in (c) to (e), the ventilation chamber 6 is provided in a plurality of layers in the Z direction.

[0097] Figure 4 The front part 2 is shown to be formed from an aluminum profile. Figure 4 (a) shows a structure with the equivalent Figure 3 (a) The cross-sectional shape, Figure 4 (b) and (c) have the equivalent Figure 3 The cross-sectional shape of (b) forms a ventilation chamber 6 divided into a plurality of parts in the Y direction. Figure 4(d) Two aluminum plates are arranged in parallel with a predetermined interval in the Z direction, and the ventilation chamber 6 has a predetermined thickness in the Z direction on the XY plane and is not divided into a plurality of parts in the Y direction.

[0098] Figure 5 The front part 2 is shown to be composed of composite overlapping plates. The plates are aluminum, zinc iron plates, SUS materials or plastic plates. The space between the overlapping plates is a ventilation chamber 6.

[0099] In addition, although the case where the front portion 2 is made of corrugated paper, a metal material, or a synthetic resin material has been exemplified, the present invention is not limited to the case where it is made of these members.

[0100] use Figure 6 , Figure 7 Explain the phenomenon of diffraction of sound.

[0101] When there is a gap, the sound is significantly diffracted behind the panel. The diffracted waves are structurally guided and contained, and the sound energy is converted into heat. That is, a ventilation chamber is set behind the surface panel to perform sound absorption.

[0102] Figure 6 The front face 2 of the sound absorbing component shown is composed of Figure 3 The surface plate of the front portion 2 is formed of a liner plate 7, and the ventilation chamber 6 is divided into a plurality of parts in the Y direction, is continuous in the X direction, and is provided in multiple layers in the Z direction.

[0103] A slit 5 is provided through the front portion 2 in the thickness direction. The slit 5 has a predetermined length in the Y direction, and a plurality of slits 5 are provided at predetermined intervals in the X direction. The slits 5 are provided at an angle of 90 degrees to the X direction. In the case where the ventilation chamber 6 is continuous in the X direction, the condition is that the slit 5 is not parallel to the ventilation chamber 6. Therefore, based on 90 degrees, 45 degrees to 135 degrees are optimal. In addition, the slits 5 are processed on the same plane and have a width of 0.5 mm or less.

[0104] like Figure 7 As shown, the straight wave of the sound entering from the slit 5 becomes a diffracted wave and is guided to the ventilation chamber 6. In the ventilation chamber 6 that guides and receives the diffracted wave, the transmission energy of the sound is converted into heat energy through physical energy such as friction and vibration, and the sound is absorbed. The diffracted wave is not only the first time, but also can be improved by the second diffracted wave and the third diffracted wave processing (multi-level processing in the Z direction). As a result, the air layer behind can be made thinner, and the thin structure of the sound absorbing component 1 can be achieved.

[0105] In the principle of sound, if the gap is narrow, diffraction occurs, and the diffraction increases as the frequency is low. Using this principle, the sound is introduced into the ventilation chamber 6, and the energy conversion of the sound is performed in the ventilation chamber 6. There is also a part of the sound that goes straight, but it has no great influence on the structure above 3 layers. The length of the ventilation chamber 6 varies (about 20mm to 200mm), so the frequency range of the sound absorption rate of the sound that enters the ventilation chamber 6 is expanded. The thickness of the sound absorbing component 1 can be reduced even at low frequencies.

[0106] Figure 8 to Figure 26 Shown are the results of tests involving normal incidence.

[0107] This test was conducted at the Osaka Industrial Technology Research Institute, a local independent corporation in Japan, using the "Sound Absorption Measurement System" of the Buick Care Type 4206, with the device number: A6001. The diameter of the "test piece" used in the sound absorption measurement system is 100 mm. The measurement method is the 2-microphone method (transfer function method). The application standards are ISO10534-2 and ASTME1050. The measurement frequency range is 100-1600 Hz.

[0108] Figure 8 , Fig. 9 Shown is the first test piece used in the above-mentioned "Sound Absorption Measurement System". Figure 8 is the front view of the test piece (front part 2), Fig. 9 : is a cross-sectional view of the test piece (front part 2). The front part 2 of the first test piece is made of fireproof corrugated paper of "double-sided corrugated paper". The thickness of the front part 2 is 3mm. In the test device, a "back air layer 3" is formed on the back of the test piece.

[0109] The ventilation chamber 6 formed in the front part 2 is continuous in the X direction and is divided into a plurality of chambers in the Y direction. The slits 5 intersect at 90 degrees with respect to the X direction. The slit width is 0.5 mm. The spacing of the slits 5 is as follows: Figure 8 shown.

[0110] Fig.10 , Fig.11 : is a graph of the vertical incidence test results of the first test piece, wherein the vertical axis is the sound absorption rate and the horizontal axis is the frequency. Fig.10 This graph shows the air layer behind the camera is set to 30 mm, and the representative frequency is 850 Hz. Fig.11 The air layer behind is set to 60mm, which represents a frequency of 600Hz.

[0111] Fig.12 is a front view of the second test piece. The second test piece has a slit 5 and an X-axis intersection angle of 60 degrees relative to the ventilation chamber 6 that is continuous in the X direction. Fig. 9The same as above, so the illustration is omitted.

[0112] Fig.13 , Fig.14 It is a graph of the vertical incidence test results of the second specimen. Fig.13 The figure shows that the air layer behind is set to 30 mm, and the representative frequency is 600 Hz. Fig.14 The back air layer is set to 50mm, which represents a frequency of 700Hz.

[0113] Figure 15 to Figure 17 is a diagram of the third specimen. The main view of the third specimen is Figure 8 The cross-sectional view is as follows: Fig.15 As shown, use Figure 3 (c) shows the general corrugated paper of "double double-sided corrugated paper". The thickness of the front part 2 is 3mm+1.5mm.

[0114] Fig.16 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 15 mm, and the representative frequency is 1200 Hz. Fig.17 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 30 mm, and the representative frequency is 600 Hz.

[0115] Figures 18 to 20 is a diagram of the fourth specimen. The front view of the fourth specimen is Fig.18 As shown in the figure, the spacing of the slits 5 is Figure 8 The spacing shown is different. Its cross-sectional view is similar to Fig.15 The cross-sectional views shown are the same and therefore are omitted in the illustration.

[0116] Fig.19 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 10 mm, and the representative frequency is 1600 Hz. Fig. 20 This is a graph showing the results of a vertical incidence test with the air layer behind set to 30 mm, and the representative frequency is 900 Hz.

[0117] Figure 21 to Figure 23 is a diagram of the fifth specimen. The front view of the fifth specimen is Figure 8 The cross section is the same as shown in FIG. Fig.21 As shown, it is equivalent to Figure 4 (a) The cross-sectional shape of the front portion 2 is that the ventilation chamber 6 is formed by the front aluminum plate 2a with a thickness of 0.8 mm and the aluminum square wave plate 2b with a thickness of 0.5 mm, and the thickness of the front portion 2 is 9 mm.

[0118] Fig. 22 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 30 mm, and the representative frequency is 850 Hz. Fig.23This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 50 mm, and the representative frequency is 600 Hz.

[0119] Figure 24 to Figure 26 is a diagram of the sixth specimen. The front view of the sixth specimen is Figure 8 The cross-sectional view is as follows: Fig.24 As shown, it is equivalent to Figure 4 (d) The cross-sectional shape of the front portion 2 is such that a front aluminum plate 2a having a thickness of 0.8 mm and a rear aluminum plate having a thickness of 0.5 mm are arranged in parallel at a predetermined interval to form a ventilation chamber 6, and the thickness of the front portion 2 is 4 mm.

[0120] Fig.25 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 30 mm, and the representative frequency is 800 Hz. Fig.26 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 50 mm, and the representative frequency is 500 Hz.

[0121] From the above experimental results, it is understood that the thickness of the sound absorbing member 1 can be reduced.

[0122] Figure 27 to Figure 29 The figure shows the front part 2 used for the sound absorbing component used for indoor use in places not subject to wind load, such as the inner wall of indoor passages, the inner wall of mechanical rooms, etc.

[0123] exist Fig. 27 In the front part 2, two flat plates with a thickness of 4 mm are arranged in parallel and held by a mold frame 9, and a ventilation chamber 6 is formed between the two flat plates. A slit 5 is provided in the front part 2.

[0124] Fig.28 The front part 2 is made of "double-sided corrugated paper". As shown in (a) of the figure, the member 10 shown in (b) of the figure is embedded and fixed to the mold frame 9 via the slit 5. That is, the gap between the member 10 and the member 10 is the slit 5.

[0125] Fig.29 The front portion 2 is shown to be made of corrugated paper, and a member 10 shown in (b) of the figure is fixed to a peripheral material 11. A plurality of slits 5 are formed in the member 10.

[0126] Fig.30 The sound absorbing material 12 is shown to be stored in the ventilation chamber 6. The front portion 2 has a surface material 13 and a plurality of lining plates 14. The surface material 13 and the lining plates 14 and the lining plates 14 serve as the ventilation chamber 6. The sound absorbing material 12 is stored in the ventilation chamber 6. The front portion 2 is provided with a slit 5 that penetrates in the thickness direction.

[0127] As the surface material 13, a straight board, asbestos cement board, etc. are used. As the lining board 14, a transparent board (plastic), plywood, cypress, fir, etc. thin plate materials are used. As the sound absorbing material 12, polyester non-woven fabric, glass wool, open cell plastic (EPDM, polyurethane), etc. are used. As the sound absorbing material 12, a metal mesh (expanded metal) can also be used.

[0128] In the above embodiment, the slit 5 is illustrated as a straight line, but it can also be a wave, an arc, or other shapes. The slit can also be used to draw a pattern to improve the decorative effect. In order to improve the decorative effect, the ventilation chamber can be not a hole but a surface (see Figure 4 (d)). The slit is preferably formed by laser processing, but can also be formed by other processing methods. The "Japanese Patent Application No. 2022-50983" of the applicant of this application can also be used. Fig.60 The "four-mesh woven structure" shown in the figure forms a slit.

[0129] Fig.31 Other embodiments of the present invention will be described below.

[0130] Fig.31 The aluminum plate 2c shown is a flat plate with a thickness of 0.5 mm. The aluminum plate 2c is formed into a rectangular shape with a long side in the X direction and a short side in the Y direction. On the aluminum plate 2c, a plurality of slits 5 penetrating in the thickness direction have a predetermined length in the X direction and are formed in a straight line at a predetermined interval in the X direction. The slits 5 are arranged in two rows at a predetermined interval in the Y direction. The slits 5 are preferably formed by laser processing, but may also be formed by stamping, punching, or machining.

[0131] The Y-direction width of the slit 5 is preferably 2 mm or less. The X-direction length of the slit 5 also depends on the plate thickness, but is about 30 to 50 mm. The slits 5 may be arranged at a pitch of 50 to 70 mm in the X-direction. The opening ratio of the slit 5 is 5% or less.

[0132] like Fig.32 As shown, the upper and lower ends of the rectangular aluminum plate 2c are folded back 180 degrees in the same direction at the position of the slit 5 to form a folded portion 2d. Between the folded portion 2d and the plane portion 2e between the slit 5, a ventilation chamber 6 of a specified thickness is formed along the Z direction. The thickness of the ventilation chamber 6 is preferably the width of the above-mentioned slit 5 or less than 0.5 to 10 mm. The thickness of the ventilation chamber 6 in the Z direction may not be constant. That is, the folded portion 2d and the plane portion 2e may not be parallel. It may also change from 0.2 mm to 8 mm in an expanded state from the folding starting point to the folding end.

[0133] Hereinafter, the part formed by folding back is referred to as the "front part 15".

[0134] like Fig.33 As shown in FIG. 1 , an additional slit 16 can be formed by laser processing in the folded portion 2d. Fig.31 The additional slit 16 is provided obliquely in the X direction, but is not limited thereto and may be perpendicular or parallel to the X direction. The additional slit 16 has a length of 50 mm or less and may be provided in various lengths and inclination angles.

[0135] like Fig.34 As shown, the front member 15 is arranged in multiple stages in close contact along the Y direction on the XY plane to form the front portion 2. The rear portion 4 is arranged on the front portion 2 via the rear air layer 3 to form the sound absorbing member 1.

[0136] The plurality of upper and lower front members 15 are connected and fixed to a support frame 2f arranged in the upper and lower directions in the rear air layer 3 by fixing rivets 2g.

[0137] Fig.35 It is an enlarged cross-sectional view of the connection portion in the slit 5 of the upper and lower front members 15, 15 of the front portion 2. As shown in the figure, in the slit 5 of the folded portion 2d, when the incident sound goes straight toward the rear air layer 3, it is diffracted toward the ventilation chamber 6 side, and the diffracted sound enters the ventilation chamber 6 from the slit 5.

[0138] The positions of the slits 5 of the upper and lower front members 15 that are in close contact with each other in the Y direction are consistent in the X direction. Moreover, the gap in the Y direction at the position of the slits 5 of the upper and lower front members 15 that are in close contact with each other does not exceed 3 mm. That is, Fig.35 The entry gap of the incident sound in is less than 3 mm. The sound entering from this gap is diffracted from the slit 5 and enters the ventilation chamber 6.

[0139] The ventilation chamber 6 has a structure that does not serve as a barrier to the sound diffracted from the slit 5 .

[0140] The ventilation chamber 6 has an inlet from the slit 5 and an outlet from the folded end communicating with the back air layer 3, and needs to be an unsealed space. In addition, the additional slit 16 also constitutes an outlet communicating with the back air layer 3.

[0141] like Fig.36 As shown, the front part 2 composed of the front member 15 can be held by an aluminum frame 17. The rear panel 4a is held on the aluminum frame 17 to form the rear part 4. The Y-direction dimensions of the front member 15 are 125 mm, 75 mm, 50 mm, 75 mm, and 125 mm from bottom to top.

[0142] Fig.37 The structure shown is that the front part 2 formed by the front part 15 is supported by the rear panel 4a. The rear panel 4a is made of zinc iron plate. The structure of the rear panel 4a is similar to Figure 2 The structures shown are largely the same.

[0143] Fig.38 and Fig.39 The spandrel-type sound absorbing device is shown, and the sound absorbing component 1 of the present invention is used as a sound absorbing device for a ceiling or a wall. A front portion 2 composed of a front member 15 is held in a spandrel-type aluminum form 18 mounted on a ceiling or a wall. The rear portion 4 may also be held in the aluminum form 18, but the ceiling or the wall itself may be used as the rear portion 4. The Y-direction dimensions of the front member 15 are 52.5 mm, 100 mm, and 52.5 mm from the bottom to the top. The interval between the ends of the folded portion 2d of the front member 15 is 15 mm. Through this interval, the ventilation chamber 6 is connected to the rear air layer 3.

[0144] The plurality of upper and lower front members 15 are connected and fixed to a support frame 2f arranged in the upper and lower directions in the rear air layer 3 by fixing rivets 2g.

[0145] Figure 40 to Figure 42 This is a picture of the seventh specimen.

[0146] Fig.40 (a) is a front view of the seventh test piece, and (b) is a cross-sectional view thereof.

[0147] The seventh test piece is Fig.39 The slit 5 shown is arranged at the center of the test piece with a Y-direction interval of 100 mm. The thickness of the aluminum plate is 0.5 mm, the length of the slit 5 in the X direction is 35 mm, and the length of the folded portion 2d in the Y direction is 35 mm and 20 mm. No additional slit 16 is formed in the folded portion 2d.

[0148] Fig.41 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 650 Hz. Fig.42 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 450 Hz.

[0149] From the above experimental results, it is understood that the thickness of the sound absorbing member 1 can be reduced.

[0150] Figure 43 to Figure 45 It is a diagram based on the eighth test piece.

[0151] Fig.43 (a) is a front view of the eighth test piece, and (b) is a cross-sectional view thereof.

[0152] The eighth test piece is Fig.36 The slit 5 shown is arranged at the center of the test piece with a 50 mm interval in the Y direction. The thickness of the aluminum plate is 0.5 mm, the length of the slit 5 in the X direction is 35 mm, and the length of the folded portion 2d in the Y direction is 15 mm and 18 mm. No additional slit 16 is formed in the folded portion 2d.

[0153] Fig.44 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 20 mm, and the representative frequency is 850 Hz. Fig.45 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 550 Hz.

[0154] Figure 46-48 It is a diagram based on the ninth specimen.

[0155] Fig.46 (a) is a front view of the ninth test piece, and (b) is a cross-sectional view thereof.

[0156] The ninth specimen and Fig.43 The test piece shown is the same, but an additional slit 16 is formed in the folded portion 2d. The additional slits 16 have X-direction pitches of 20 mm, 25 mm, and 20 mm, and are provided orthogonally to the X direction.

[0157] Fig.47 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 800 Hz. Fig.48 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 600 Hz.

[0158] Figures 49 to 51 This is a diagram based on the tenth specimen.

[0159] Fig.49 (a) is a front view of the tenth test piece, and (b) is a cross-sectional view thereof.

[0160] The tenth specimen is Fig.40 The test piece shown has the same shape, but is made of galvanised iron with a thickness of 0.27 mm, and has an additional slit 16 formed in the folded portion 2d. The additional slits 16 have X-direction pitches of 20 mm, 25 mm and 20 mm, and are provided orthogonally to the X direction.

[0161] Fig.50 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 750 Hz. Fig.51 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 40 mm, and the representative frequency is 500 Hz.

[0162] Figure 52 to Figure 54 This is a picture of the eleventh specimen.

[0163] Fig.52 (a) is a front view of the eleventh test piece, and (b) is a cross-sectional view thereof.

[0164] The eleventh specimen is Fig.46 The test piece shown has the same shape, but is made of a 0.27 mm thick galvanized iron plate, and has an additional slit 16 formed in the folded portion 2d. The additional slits 16 have X-direction pitches of 20 mm, 25 mm, and 20 mm, and are provided orthogonally to the X direction.

[0165] Fig.53 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 750 Hz. Fig.54 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 40 mm, and the representative frequency is 500 Hz.

[0166] Figure 55 to Figure 57 This is a diagram of the twelfth specimen.

[0167] Fig.55 (a) is a front view of the twelfth test piece, and (b) is a cross-sectional view thereof.

[0168] The twelfth specimen is Fig.52 The test pieces shown are of the same shape but are made of stainless steel with a thickness of 0.2 mm.

[0169] Fig.56 This is a graph of the measurement results of a vertical incidence test with the air layer behind set to 20 mm, and the representative frequency is 850 Hz. Fig.57 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 600 Hz.

[0170] Figures 58 to 60 This is a picture of the thirteenth specimen.

[0171] Fig.58 (a) is a front view of the thirteenth test piece, and (b) is a cross-sectional view thereof.

[0172] The thirteenth specimen is Fig.55 The test piece shown has the same shape, but is made of aluminum with a thickness of 0.5 mm, and an additional slit 16 is provided in the folded portion 2d so as to be inclined in the X direction.

[0173] Fig.59 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 800 Hz. Fig.60 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 600 Hz.

[0174] Figure 61 to Figure 63 It is a diagram based on the fourteenth specimen.

[0175] Fig.61(a) is a front view of the fourteenth test piece, and (b) is a cross-sectional view thereof.

[0176] The fourteenth specimen is Fig.58 The test pieces shown have the same shape, but differ in that an additional slit 16 is provided in parallel with the X direction in the folded portion 2d.

[0177] Fig.62 This is a graph of the measurement results of a vertical incidence test with a rear air layer of 20 mm, and the representative frequency is 900 Hz. Fig.63 This is a graph of the measurement results of a vertical incidence test with the rear air layer set to 40 mm, and the representative frequency is 600 Hz.

[0178] According to the above-described embodiment, since the ventilation chamber 6 is formed by the folded portion, the thickness of the ventilation chamber 6 in the Z direction can be reduced, and as a result, the thickness of the front portion 2 can be reduced.

[0179] The material of the front member 15 is not limited to metal materials such as zinc iron plate, stainless steel, and aluminum, but may also be plastic materials such as polycarbonate and PET.

[0180] Since the front portion 2 is formed of the folded front member 15, the strength can be improved despite being thin.

[0181] Since the opening ratio of the front part 2 is extremely low, new added value can be given to the surface, for example, it can be used as a radio wave and whistle sound wave absorbing panel, noise under beams and underground roads, ETC radio wave countermeasures, tunnel sound absorbing panels, and tunnel lighting.

[0182] The present invention is not limited to the above-mentioned embodiments or samples.

[0183] The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0184] Description of Reference Numerals

[0185] 1 Sound absorbing components

[0186] 2 Front

[0187] 2a Front aluminum plate

[0188] 2b aluminum square wave plate

[0189] 2c Aluminum Plate

[0190] 2d fold

[0191] 2e Plane

[0192] 2f Support frame

[0193] 2g fixing rivets

[0194] 3. Back air layer

[0195] 4. Back

[0196] 4a Rear panel

[0197] 4b Upper panel

[0198] 4c Lower panel

[0199] 4d rib

[0200] 4e Rib

[0201] 5 Slit

[0202] 6 Ventilation chamber

[0203] 7 Liner

[0204] 8 SMIC Paper

[0205] 9 Frame

[0206] 10 Components

[0207] 11 Peripheral materials

[0208] 12 Sound-absorbing materials

[0209] 13 Surface material

[0210] 14 Liner

[0211] 15 front piece

[0212] 16 Additional slits

[0213] 17 Aluminum frame

[0214] 18 Spandrel aluminum formwork.

Claims

1. A sound absorbing member comprising: a front face portion on a sound source side having an XY plane; and a rear face portion disposed on the front face portion via a rear air layer having a thickness in the Z direction; The front portion is provided with a plurality of slits communicating with the rear air layer at a predetermined length and a predetermined pitch, and a ventilation chamber is provided with a predetermined thickness in the Z direction on the XY plane to guide and contain diffracted waves of sound incident from the slits.

2. The sound absorbing component according to claim 1, wherein: The ventilation chamber is divided into a plurality of parts in the Y direction and is continuous in the X direction. The slits are linear and intersect at 45 to 135 degrees with respect to the X direction.

3. The sound absorbing component according to claim 2, wherein: The ventilation chamber is provided with multiple layers in the Z direction.

4. The sound absorbing component according to claim 2 or 3, wherein: The front portion is formed of any one of corrugated paper, metal material or synthetic resin material.

5. The sound absorbing component according to claim 4, wherein: A sound absorbing material is accommodated in the ventilation chamber.

6. The sound absorbing component according to claim 1, wherein: The ventilation chamber is divided into a plurality of parts in the Y direction and is continuous in the X direction. The slit is linear and parallel to the X direction.

7. The sound absorbing component according to claim 6, wherein: The slits are formed in a plurality of positions in the Y direction at a predetermined distance from the upper and lower ends in the Y direction of the flat plate having the XY plane, with a predetermined length in the X direction and a predetermined pitch in a straight line, The Y-direction end of the flat plate is folded back 180 degrees at the slit position to form a front member, The front part is configured in a multi-stage close-fitting manner in the Y direction to form the front part, The folded portion of the front member forms the ventilation chamber.

Images