WO2008007447A1

WO2008007447A1 - Translucent perforated laminate acoustical board and translucent acoustical panel

Info

Publication number: WO2008007447A1
Application number: PCT/JP2006/314318
Authority: WO
Inventors: Toru Morimoto; Masamichi Sekiya; Toshio Mitsuoka; Kunihide Ito
Original assignee: Unix Corporation Ltd.
Priority date: 2006-07-13
Filing date: 2006-07-13
Publication date: 2008-01-17
Also published as: JP4975744B2; JPWO2008007447A1

Abstract

An acoustical panel which is excellent in sound absorbing characteristics, provided with translucency and transparency, hard to be contaminated, and free from erroneous operation of highway ETC devices. An acoustical board is used that is obtained by laminating two transparent, perforated resin sheets, each having a thickness of 1-5mm, a hole diameter of 1-10mm and an aperture ratio of 5-50%, so as not provide through openings. The acoustical pane comprises this acoustic board disposed on a sound source side and a transparent resin sound shield board on an anti-sound source side that are held by a frame member and, if necessary, a middle rail. A sound absorbing material such as a soft fibrous sound absorbing material is preferably lined further on the insides of the frame member and the middle rail.

Description

Technical description Transparent light-transmitting laminated sound absorbing plate and light transmitting sound absorbing panel Technical Field

The present invention belongs to a technical field related to a sound absorbing material and a translucent sound absorbing panel. Specifically, the present invention relates to a translucent sound-absorbing plate that has not only a sound-absorbing characteristic but also a watermark through a sound-absorbing material and that does not reflect radio waves. Background art

When a perforated plate material such as gypsum paste calcium silicate plate is used as a sound absorbing material, it is common to use a soft fibrous porous sound absorbing material such as rock wool or glass wool as the base material. In addition, a translucent sound absorbing plate in which a transparent resin thin film is sandwiched between aluminum expanded metals has been put into practical use. A sound-absorbing plate using a conventional perforated plate such as a gypsum-padded calcium silicate plate cannot obtain sufficient sound-absorbing characteristics only through an air layer. Therefore, since ground materials such as glass wool and rock wool are necessary, there are inherent problems such as the generation of scattered materials when dismantling them. These sound absorbing plates have no translucency or transparency.

The translucent sound-absorbing plate uses a fluorine-based transparent resin thin film. This is not only possible due to the collision of small flying substances, but also in the air due to the occurrence of static electricity. There are inherent problems such as being easily adsorbed by dust.

In addition, the translucent membrane vibration sound absorbing plates of Japanese Patent Nos. 2518589 and 3392070 invented by the present inventors use two aluminum expanded metals having a mesh size of 2 Om or less. Therefore, when this translucent membrane vibration absorbing material is used in the vicinity of ITS (Intelligent Transport System) and ETC (Automatic Toll Collection System), the radio waves for exchanging information with the vehicle are reflected. There is a risk of malfunction or radio interference. Disclosure of the invention

The object of the present invention is to solve the above-mentioned problems, and to transmit light without wave reflection. Another object of the present invention is to provide a translucent perforated laminated sound absorbing plate and a translucent sound absorbing panel having excellent visibility and transparency.

The present applicants have found a translucent perforated laminated sound-absorbing plate having good sound-absorbing characteristics using two transparent perforated resin plates without using a transparent resin thin film, and have arrived at the present invention. It is.

The first invention of the present invention is a translucent perforated laminated sound absorbing plate in which two transparent perforated resin plates are laminated, and the thickness of the two transparent perforated resin plates is 1 mm to 5 mm, In addition, the hole diameter ranges from 1 mm to 10 mm, and the respective opening ratios range from 5% to 50%, and there is no common opening in the state in which two transparent perforated resin plates are laminated. This is a translucent perforated laminated sound-absorbing plate.

The second invention is the translucent perforated laminated sound absorbing plate described in the first invention, wherein at least one portion of the two transparent perforated resin plates is mutually attached via rivets or an adhesive. A translucent hole-opening layer sound-absorbing plate characterized in that the sound-absorbing property is improved by improving the adhesion between the two transparent hole-opening resin plates by fixing.

According to a third aspect of the present invention, there is provided the translucent perforated laminated sound absorbing plate described in the first and second aspects of the invention on the sound source side, and a transparent resin sound insulating plate on the anti-sound source side. The light-transmitting sound-absorbing panel is characterized in that an air layer is formed by holding a member using a middle rail if necessary.

The fourth invention is a soft fiber-based porous sound absorbing material or an open-cell type elastic foam sound absorbing material which is provided with a waterproof measure on the inner side of the frame member and center rail of the translucent sound absorbing panel described in the third invention. This is a translucent sound-absorbing panel characterized by being used as an auxiliary sound-absorbing material.

By using the translucent perforated laminated sound-absorbing plate of the present invention, a translucent sound-absorbing panel excellent in translucency and see-through is provided, and translucency without reflection of radio waves from the sound-absorbing plate is provided. A mold sound absorbing panel can be provided. For applications that do not matter for translucency, see-through, and radio wave reflection, a metal perforated plate may be used instead of the transparent perforated resin plate of the present invention. Brief Description of Drawings

FIG. 1 is a conceptual plan view of a translucent perforated laminated sound absorbing plate (Example 1) of the present invention. 2 is a cross-sectional view taken along the line aa in FIG.

FIG. 3 is a schematic plan view of Comparative Example 1 in which the hole positions of two transparent perforated resin plates are matched.

4 is a cross-sectional view taken along line bb in FIG.

FIG. 5 is a schematic plan view of another translucent perforated laminated sound absorbing plate (Example 2) of the present invention.

6 is a cross-sectional view taken along line c in FIG.

FIG. 7 is a conceptual plan view of Comparative Example 2 in which the hole positions of two transparent perforated resin plates are matched.

8 is a cross-sectional view taken along d-d in FIG.

FIG. 9 (a) is a schematic diagram of the translucent sound absorbing panel used in the examples and comparative examples of the present invention, and (b) is a cross-sectional view taken along line ee.

FIG. 10 is an explanatory diagram of a translucent sound absorbing panel of Example 1. FIG.

FIG. 1 1 is an explanatory diagram of a translucent sound absorbing panel of Comparative Example 1.

FIG. 12 is an explanatory diagram of a translucent sound absorbing panel of Example 2. FIG.

FIG. 3 is an explanatory diagram of a translucent sound absorbing panel of Comparative Example 2.

Fig. 14 is an explanatory diagram of a translucent hole-laminated laminated sound absorbing plate of Examples 3, 4, and 5.

FIG. 15 is an explanatory view of a translucent sound absorbing panel of Example 3.

FIG. 16 is an explanatory diagram of a translucent sound absorbing panel of Example 4. FIG.

Fig. 17 is a diagram showing the sound absorption characteristics of the translucent sound absorbing panels of Example 1 and Comparative Example 1. Fig. 18 is a diagram showing the sound absorbing characteristics of the translucent sound absorbing panels of Example 2, Comparative Example 2 and Example 3. It is.

FIG. 19 is a diagram comparing the sound absorption characteristics of Example 3 and Example 4 with two transparent poly-single-pone laminates without holes.

FIG. 20 is a diagram comparing the sound absorption characteristics of Example 4 and Example 5. FIG.

Explanation of symbols

1 1 Translucent perforated laminated sound absorber (Example 1)

1 2 Transparent plastic plate with sound source side

1 3 Clear hole side plastic resin plate

1 Translucent perforated laminated sound absorber (Comparative example 1) 1 5 Sound source side transparent perforated resin plate

1 6 Opposite sound source side transparent perforated resin plate

1 7 Translucent perforated laminated sound absorber (Example 2)

1 8 Translucent perforated laminated sound absorber (Comparative example 2)

1 9 Frame member

2 0 Middle pier

2 1 Transparent polycarbonate sound insulation board

2 2 Enclosure

2 3 Translucent sound absorbing panel (Example 1)

2 4 Translucent sound absorbing panel (Comparative Example 1)

2 5 Translucent sound absorbing panel (Example 2)

2 6 Translucent sound absorbing panel (Comparative Example 2)

2 7 Translucent perforated laminated sound absorber (Examples 3, 4 and 5)

2 8 Translucent sound-absorbing panel (Example 3)

2 9 Transparent double-sided tape

3 0 Open-cell elastic foam sound absorber

3 1 Fluorine resin thin film

3 2 Auxiliary sound absorber

3 3 Translucent sound absorbing panel (Example 4) Best mode for carrying out the invention

The translucent perforated laminated sound absorbing plate of the present invention and the translucent sound absorbing panel using the same will be described in detail with reference to the accompanying drawings.

1 and 2 are conceptual diagrams of a translucent perforated laminated sound absorbing plate 11 according to the present invention. The solid line indicates the sound source side transparent perforated resin plate 12, and the broken line indicates the counter sound source side transparent perforated resin plate 13. Figure 2 shows a schematic cross-sectional view along the line aa in Figure 1.

As is clear from Figs. 1 and 2, the openings of the two transparent holed resin plates 1 2 and 1 3 do not overlap. If there is an overlap (a common opening), the sound absorption rate is greatly reduced.

The opening shapes of the sound source side transparent perforated resin plate 1 2 and the counter sound source side transparent perforated resin plate 1 3 in Fig. 1 are shown in a circular staggered arrangement, but this shape does not matter. It can also be a rectangle, square, or triangle. An opening ratio in the range of 5% to 50% is practical, but a range of 10% to 40% is more preferable.

When the opening ratio exceeds 50%, the contact area between the non-opening portions of the two transparent holed resin plates decreases, and the sound absorption phenomenon due to friction caused by vibration of the two transparent holed resin plates described later (sound absorption) A) and sound absorption phenomenon (sound absorption B) based on air gap resistance is reduced, so the sound absorption characteristics deteriorate. In addition, a large aperture ratio causes a problem in the strength of the transparent perforated resin plate.

When the aperture ratio is less than 5%, the sound wave is not only largely reflected from the sound source side transparent perforated resin plate 12, but also the incident sound wave is difficult to penetrate the counter sound source side transparent perforated resin plate 13. Therefore, the translucent perforated laminated sound-absorbing plate is similar to the case of two transparent polycarbonate plates without holes, as shown in Fig. 19 described later, and the sound-absorbing plate deteriorates because the sound-absorbing properties are deteriorated. It cannot be.

The plate thickness of the transparent perforated resin plates 1 2, 1 3, 15, and 16 in the present invention is in the range of l mm to 5 mm, more preferably in the range of 1.5 mm to 2.0 mm. If the plate thickness exceeds 5 mm, it will be disadvantageous from an economic point of view, even if the strength is sufficient. In addition, if the thickness of the transparent perforated resin plate is less than 1 mm, strength problems and difficulty in carrying out weathering treatment will occur. However, as mentioned above, for applications where translucency, watermarking and radio wave reflection are not a problem, it is possible to use a plate thickness of 1 mm or less by using a metal perforated plate.

Since the sound absorbing mechanism of the present invention does not use a resin thin film, it is not a sound absorbing mechanism by membrane vibration. In addition, although two perforated plates are used, there is no consistent opening in the perforated plates, so the resonance sound absorption mechanism using perforated plates cannot be explained. In addition, when a plate vibration, that is, a sound wave collides with the plate-like body and the plate is temporarily twisted or bent, the plate will vibrate in an attempt to return according to the elasticity inherent in the plate. At this time, the sound energy is converted into vibrational energy and absorbed. However, the sound absorption rate by this sound absorption mechanism is generally not sufficient.

Fig. 19 In Example 3 and Example, a transparent polycarbonate plate with a thickness of 1.5 mm, which is the same as the one used in this example, was used as a sound absorbing plate. The result of the reverberation room method sound absorption coefficient measured in the same manner as in 4 is shown. The sound absorption coefficient of the sound absorption board with two transparent polycarbonate plates without holes is about 0.4, although the sound absorption coefficient peak is at 1 25 Hz, and the overall sound absorption coefficient is extremely low. It cannot be a sound absorbing plate.

On the other hand, it is apparent that the sound absorption characteristics are greatly improved by using the method of the present invention in Examples 3 and 4 of the present invention, also shown in FIG.

As a result of repeated experiments using various perforated plates, the sound absorbing mechanism of the present invention is inferred as follows. That is, when the entire laminate is vibrated by sound waves, friction caused by vibration occurs between the two perforated plates, and part of the sound energy is converted into heat energy to absorb the sound. (Hereafter referred to as sound absorption A)

Next, the sound wave that has entered from the hole on the sound source side passes through the gap between the two holes, and passes through the hole on the side opposite the sound source. Part is converted into heat energy and absorbed. (Hereinafter referred to as sound absorption B.) Therefore, it is presumed that the sound absorption phenomenon of the translucent perforated laminated sound absorbing plate of the present invention is mainly caused by the above (sound absorption A + sound absorption B).

The present inventors have already applied for a patent for a membrane vibration sound absorbing plate in which a transparent fluorinated styrene resin thin film is sandwiched between two transparent perforated resin plates (Japanese Patent Application No. 2 0 0 4-1 6 6 4 9 1) In these development processes, the present invention was accomplished by finding a translucent perforated laminated sound absorbing plate with good sound absorbing characteristics without using the resin thin film. Example

FIG. 9A is an explanatory diagram of an example of a translucent sound-absorbing panel of 200 mm × 10 mm × 90 mm. A casing 2 2 having four circumferences made of frame members 19 is formed. P I, P 2, P 3, and P 4 are, for example, surfaces on the sound source side of the housing 22, and are portions on which the translucent perforated laminated sound absorbing plates are arranged. A transparent resin sound insulating plate 21 made of polycarbonate having a thickness of 5 dragons is attached to the surface S 1, S 2, S 3, S 4 on the side opposite to the sound source. An intermediate beam 20 was provided for the purpose of preventing stagnation when a translucent perforated laminated sound absorbing plate was arranged on the sound source side surface. The frame member 19 and the middle beam 20 are formed by forming a 1 mm thick aluminum plate into a hollow prism shape, and the thickness of the hollow prism is 25 mm. FIG. 9 (b) is a cross-sectional view taken along line e-1e in FIG. 9 (a). The light absorbing performance of each case was compared by arranging a transparent type perforated laminated sound absorbing plate of Example or Comparative Example on the P I, P 2, P 3 and P 4 surfaces of the casing 22. (Example 1)

The translucent perforated laminated sound absorbing plate 11 used in Example 1 is shown in FIG. Sound source side transparent hole opening The resin plate 12 is a staggered arrangement with a polycarbonate thickness of 1.5 mm, an opening diameter of 1 O mm, an opening center distance (pitch) of 16 mm, and an opening angle of 60 degrees. An aperture ratio of 35% was used.

Also, the transparent sound-resin-side resin plate 13 on the opposite side of the sound source has a polycarbonate thickness of 1.5 mm, an opening diameter of 6 mm, an opening center distance (pitch) of 16 mm, and an opening angle. Was a staggered array of 60 degrees and an aperture ratio of 13%. Figure 2 shows a cross-sectional view along the line aa in Figure 1.

Set the above two transparent holed resin plates 1 2 and 1 3 so that their openings do not overlap as shown in the conceptual diagrams of Fig. 1 and Fig. 2, that is, there is no common through opening. Thus, a translucent perforated laminated sound absorbing plate 11 was obtained by fastening both ends on the long side with tape.

As shown in Fig. 10, this translucent perforated laminated sound absorbing plate 11 is placed on the case 2 2 in Fig. 9 (placed on the P1, P2, P3, and P4 surfaces in Fig. 9). It was set as the light type sound absorption panel 23. Example 1 of Fig. 17 shows the results of measuring the sound absorption coefficient of the reverberation chamber method for this translucent sound-absorbing panel 23 according to JIS A 1 4 0 9-1 9 98.

(Comparative Example 1)

Figure 3 shows the translucent perforated laminated sound absorber 14 used. The sound source side transparent perforated resin plate 1 2 and the counter sound source side transparent perforated resin plate 1 3 are the same as those in Example 1, but as is clear from FIGS. 3 and 4, the sound source side transparent perforated resin plate 1 3 is the same. Resin plate 1 2 and transparent sound source side transparent hole opening Resin plate 1 3 has the same hole position. Therefore, it has a through-opening (opening ratio: 13%) based on the transparent hole opening resin board on the opposite side of the sound source with a small hole diameter.

This translucent perforated laminated sound absorbing plate 14 was placed on a housing 2 2 as shown in FIG. The result of measuring the sound absorption coefficient of the reverberation chamber method for this translucent sound-absorbing panel 24 in the same manner as JIS A 1 4 0 9-1 9 98 is shown in Comparative Example 1 in FIG.

Fig. 1 By comparing the sound absorption coefficient of the reverberation chamber method in Example 1 and Comparative Example 1 in Fig. 7, a common through-opening occurs in a translucent perforated laminated sound absorbing plate in which two perforated plates are laminated. It is clear that the sound absorption characteristics are greatly improved by laminating the layers so that they do not.

(Example 2)

The translucent perforated laminated sound absorbing plate 17 used is shown in Figs. Sound source side transparent hole opening resin The plate 15 is made of polycarbonate, with a thickness of 1.5 mm, opening ridges of 3 mm, opening center distance (pitch) of 8 mm, opening angle of 60 degrees and a zigzag arrangement with an opening ratio of 13% Was used. Also, the non-sound source side transparent perforated resin plate 16 having the same specifications as the sound source side transparent perforated resin plate 15 was used.

As shown in the conceptual diagrams of Fig. 5 and Fig. 6, set the two transparent hole resin plates 15 and 16 so that the openings do not overlap, that is, there is no common through-opening. Then, a translucent perforated laminated sound absorbing plate 17 was obtained by fastening both ends on the long side with tape.

This translucent perforated laminated sound absorbing plate 17 is placed on the housing 22 as shown in Fig. 12 (located on the PI, P2, P3, and P4 surfaces in Fig. 9). It was set to 5. Example 2 of FIG. 18 shows the result of measuring the sound absorption coefficient of the reverberation chamber method according to JI S A 1409-1998 in the same manner as described above.

(Comparative Example 2)

The translucent perforated laminated sound absorbing plate 18 used is shown in Figs. The sound source side transparent perforated resin plate 15 and the counter sound source side transparent perforated resin plate 16 are the same as those in Example 2, but as is clear from FIGS. The hole positions of the resin plate 15 and the non-sound source side transparent holed resin plate 16 are the same. Therefore, the common through-opening ratio is 13% corresponding to the transparent holed resin plates (15 and 16) with a diameter of 3 mm.

This translucent perforated laminated sound absorbing plate 18 was placed on the housing 22 as shown in FIG. Comparative Example 2 in FIG. 18 shows the result of measuring the sound absorption coefficient of the reverberation room method for this translucent sound absorbing panel 26 in accordance with JIS A 1 09-1998 as described above.

By comparing the sound absorption coefficient of the reverberation chamber method of Example 2 and Comparative Example 2 in Fig. 8, the translucent perforated laminated sound absorbing plate (1 1 and 14) with the combination of 0 10 mm and φ 6 mm was obtained. Similar to the case of Example 1 and Comparative Example 1 used, this is also common to the translucent holed laminated sound absorbing plates 1 7 and 1 8 in which two holes of 03 mm and ø 3 mm are laminated. It is again clear that the sound absorption coefficient is greatly improved by laminating so that the opening (through opening) does not occur.

(Example 3)

The translucent perforated laminated sound-absorbing plate 27 used will be explained using the conceptual diagrams shown in Figs. Sound source side transparent perforated resin plate 1 5 and anti-sound source side transparent perforated resin plate 1 6 The same aperture diameter as used in Example 2 is 3 mm. As is clear from FIG. 14, the two perforated plates were overlapped so that the respective opening portions did not overlap at all as in the case of Example 2. Furthermore, using a double-sided tape 29 with a width of 5 mm, as shown in Fig. 14 and Fig. 15, two transparent strips are attached along the longitudinal direction of the laminate as shown in Figs. The perforated resin plates 15 and 16 were fixed to each other to obtain a translucent perforated laminated sound absorbing plate 27.

Place this translucent perforated laminated sound absorbing plate 27 on the housing 2 2 as shown in the conceptual diagram of Fig. 15 (placed on the PI, P2, P3, and P4 surfaces in Fig. 9). It was set as the light type sound absorption panel 28. The results of measuring the sound absorption coefficient of the reverberation chamber method in accordance with J IS A 1 4 0 9 — 1 9 98 for this translucent sound absorbing panel 28 are shown in Example 3 of FIGS. 18 and 19.

Example 2 where two transparent perforated resin plates 15 and 16 are fixed with double-sided tape 29, as shown in Fig. 14 and Fig. 15. Example 2 In comparison with Fig. 18, improvement in sound absorption characteristics is observed particularly in the frequency range from 3 15 Hz to 100 00 Hz, as shown in Fig. 18.

The reason for the improved sound absorption characteristics is that the sound absorption B described above by fixing with double-sided tape, that is, the sound wave that has entered from the hole on the sound source side passes through the gap between the two holes, and the hole on the opposite sound source side. It passes through the open part, but it is presumed that the void resistance at this time has increased.

(Example 4)

The translucent perforated laminated sound absorbing plate used is the same as that of Example 3 shown in FIG. In other words, two transparent perforated resin plates 15 and 16 with a hole diameter of Φ 3 mm and a thickness of 1.5 mm are stacked so that the openings do not overlap at all, and a double-sided tape 29 with a width of 5 mm is attached. It is used as shown in FIGS. 14 and 16 and the above-mentioned transparent perforated resin plates 15 and 16 are fixed to each other.

Fig. 16 shows the translucent sound absorbing panel 33 used. Open-celled elastic with a thickness of 25 mm and a height of 9 O mm on the inner side of the frame member 1 of the housing 2 1 and one side of the middle rail 20 (the lower side in the case of a panel for a vertical soundproof wall) The foam sound-absorbing material 30 was wrapped in a fluorine-based resin thin film 31 having a thickness of 21 μπι to obtain an auxiliary sound-absorbing material 3 2.

Here, the open-cell elastic foam sound absorbing material 30 has a very dense internal cell (pore) structure made of resin, and these cells (pores) are connected to each other so that the front and back surfaces of the material are air. Is a foam with a structure (open cell) that can pass through (Vibrating air particles) receive frictional resistance that passes through the pores and are converted to thermal energy to be absorbed.

The results of measuring the sound absorption coefficient of the reverberation chamber method for this translucent sound absorbing panel 33 in accordance with JIS A 1409-1998 are shown in Example 4 of FIG. 19 in comparison with Example 3. As is apparent from Fig. 19, the use of the auxiliary sound absorbing material 32 improves the sound absorbing characteristics at frequencies of 500 Hz and higher.

(Example 5)

The translucent sound-absorbing panels used in Examples 1 to 4 and Comparative Examples 1 and 2 were all shown in FIG. 9 when 2000 mm × 1 000 mm × 90 mm, ie, the air layer was 9 Omm.

In this example, a transparent sound-absorbing panel (not shown) having 2000 mm × 100 Omm × 5 Omm, that is, an air layer of 5 Omm, was manufactured, and the joined transmission shown in FIG. Optically perforated laminated sound absorber 27 and a continuous foam-type elastic foam sound absorber 30 wrapped in a fluororesin thin film 31 with a length of 5 Omm in the same manner as shown in Fig. 16 as an auxiliary sound absorber Used as 32.

With respect to this translucent sound absorption panel (not shown, but the same structure as in FIG. 16), the results of measuring the sound absorption coefficient of the reverberation chamber method in accordance with JISA 109-998 are shown in FIG. Shown in comparison with the graph.

As is clear from FIG. 20, in the translucent perforated laminated sound absorbing plate of the present invention, it is confirmed that the sound absorption characteristic curve moves to the higher frequency side when the air layer is reduced, as in the case of other plate-shaped sound absorbing materials. did it.

As mentioned in the background section, a light-transmitting membrane vibration sound absorbing plate using a conventional fluorine-based transparent resin thin film adsorbs fine exhaust gas dust in the air due to the occurrence of static electricity. In the case of the sound-absorbing plate of the present invention, the resin-absorbing plate does not use a resin thin film, and is only a transparent resin plate made of polycarbonate, which is caused by adsorption of fine exhaust gas dust caused by static electricity. Dirt is reduced. Industrial applicability

By using resin-made translucent perforated laminated sound absorbers, translucent perforated laminated sound absorbers and translucent sound absorbing panels that do not reflect radio waves and have excellent translucency and see-through properties can be obtained. . For applications where light transmission, see-through, and radio wave reflection are not an issue, the use of a metal perforated laminated vibration-absorbing plate makes it possible to use holes with excellent heat resistance, fire resistance, wind resistance, etc. There is a possibility of being used for open laminated vibration absorbing plates and sound absorbing panels.

Claims

The scope of the claims

(1) In a translucent perforated laminated sound absorbing board in which two transparent resin plates are laminated, the thickness of the two transparent resin plates is 1 mm to 5 mm and the hole diameter is 1 mm to 1 O mm, each aperture ratio is in the range of 5% to 50%, and there is no common opening in the state where two transparent holed resin plates are laminated. Perforated laminated sound absorbing board.

(2) Improving the adhesion of the two transparent holed resin plates by fixing at least one of the two transparent holey resin plates with a reppet or an adhesive. The translucent perforated laminated sound absorbing plate according to claim 1, wherein the sound absorbing characteristics are improved.

(3) The translucent perforated laminated sound absorbing board according to claim 1 or claim 2 is provided on the sound source side and a transparent resin sound insulating board on the opposite sound source side, and these are used as frame members. In some cases, the translucent sound-absorbing panel is characterized in that an air layer is formed by holding it with an intermediate rail.

(4) A soft fiber porous sound absorbing material or an open-cell elastic foam sound absorbing material with water-proofing measures used as an auxiliary sound absorbing material on the inner side of the frame member and middle rail of the translucent sound absorbing panel. The translucent sound-absorbing panel according to claim 3.