JP4975744B2 - Translucent perforated laminated sound absorbing plate and translucent sound absorbing panel - Google Patents

Description

  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 property but also a watermark property through a sound-absorbing material and that does not reflect radio waves.

When a perforated plate material such as a gypsum board or a calcium silicate plate is used as a sound absorbing material, it is common to use a soft, porous porous sound absorbing material such as rock wool or glass wool as a base material. In addition, as a translucent sound absorbing plate, a transparent resin thin film sandwiched between aluminum expanded metals has been put into practical use.
A sound absorbing plate using a conventional perforated plate such as a gypsum board or a calcium silicate plate cannot obtain sufficient sound absorbing characteristics only through an air layer. Therefore, since a ground material such as glass wool or rock wool is necessary, there is a problem of generation of scattered substances when disassembling them. Further, these sound absorbing plates have no translucency or see-through property.
In addition, a fluorine-based transparent resin thin film is used for the translucent sound-absorbing plate. This may be caused by the occurrence of static electricity or the like in addition to the possibility of opening by collision of small flying substances. There are inherent problems such as being easily adsorbed by dust.
Moreover, the translucent type | mold film vibration sound-absorbing board of Japanese Patent Nos. 2518589 and 3392070 invented by the present inventors uses two aluminum expanded metals having a mesh size of 20 mm 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.

An object of the present invention is to provide a translucent perforated laminated sound absorbing plate and a translucent sound absorbing panel that solves the above-described problems and that has no radio wave reflection and has excellent translucency and transparency. Applicants have found a translucent perforated laminated sound absorbing plate having good sound absorbing characteristics without using a transparent resin thin film using two transparent perforated resin plates and have arrived at the present invention. It is.
The first invention of the present invention is a translucent perforated laminated sound absorbing board in which two transparent perforated resin plates are laminated, the thickness of the two transparent perforated resin plates is 1 mm to 5 mm, and the hole diameter 1 mm to 10 mm and the respective opening ratios are in the range of 5% to 50%, and the two transparent perforated resin plates are laminated without using a transparent resin thin film . A state in which at least one portion of the transparent perforated resin plate is fixed to each other via an adhesive, and the sound absorption characteristics are improved and laminated by improving the adhesion of the two transparent perforated resin plates characterized in that the common aperture free Kushida in a light-transmissive hole opens laminate sound absorbing plate.
Further, the second invention provides a transparent resin sound insulating plate on the sound source side and a transparent resin sound insulating plate on the opposite sound source side of the translucent perforated laminated sound absorbing plate described in the first invention, and these are arranged as a frame member and a middle member. It is a translucent sound-absorbing panel characterized in that an air layer is formed by holding it with a crosspiece.
Further, the third invention is a soft fiber porous sound absorbing material or an open-cell elastic foam sound absorbing material in which a waterproof measure is taken inside the frame member and the middle rail of the translucent sound absorbing panel according to the second invention. A translucent sound-absorbing panel that is 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 watermarking is provided, and a translucent sound absorbing panel free from radio wave reflection from the sound absorbing plate is provided. can do. In addition, regarding the use which does not consider translucency, see-through property, 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 THE DRAWINGS FIG. It is aa sectional drawing of FIG. It is a plane conceptual diagram of the comparative example 1 which made the hole position of two transparent perforated resin plates correspond. It is bb sectional drawing of FIG. It is a plane conceptual diagram of another translucent perforated laminated sound absorbing plate (Example 2) of the present invention. It is cc sectional drawing of FIG. It is a plane conceptual diagram of the comparative example 2 which made the hole position of two transparent perforated resin plates correspond. It is dd sectional drawing of FIG. (A) is a conceptual diagram of the translucent sound absorption panel used for the Example and comparative example of this invention, (b) is ee sectional drawing. It is explanatory drawing of the translucent sound absorption panel of Example 1. FIG. It is explanatory drawing of the translucent type sound-absorption panel of the comparative example 1. It is explanatory drawing of the translucent type sound absorption panel of Example 2. FIG. It is explanatory drawing of the translucent type sound-absorption panel of the comparative example 2. It is explanatory drawing of the translucent holed laminated sound-absorbing board of Example 3, 4, 5. FIG. It is explanatory drawing of the translucent type sound-absorption panel of Example 3. FIG. It is explanatory drawing of the translucent type sound-absorption panel of Example 4. FIG. It is a figure which shows the sound absorption characteristic of the translucent sound absorption panel of Example 1 and Comparative Example 1. It is a figure which shows the sound absorption characteristic of the translucent sound absorption panel of Example 2, the comparative example 2, and Example 3. FIG. It is the figure which compared the sound absorption characteristic of two transparent polycarbonate laminated sheets without a hole, and Example 3 and Example 4. FIG. It is the figure which compared the sound absorption characteristic of Example 4 and Example 5. FIG.

Explanation of symbols

11 Translucent perforated laminated sound absorbing plate (Example 1)
12 sound source side transparent perforated resin plate 13 counter sound source side transparent perforated resin plate 14 translucent perforated laminated sound absorbing plate (Comparative Example 1)
DESCRIPTION OF SYMBOLS 15 Sound source side transparent perforated resin board 16 Anti-sound source side transparent perforated resin board 17 Translucent type perforated laminated sound absorbing board (Example 2)
18 Translucent perforated laminated sound absorber (Comparative Example 2)
DESCRIPTION OF SYMBOLS 19 Frame member 20 Middle crosspiece 21 Transparent polycarbonate sound insulation board 22 Case 23 Translucent sound absorption panel (Example 1)
24 Translucent sound absorbing panel (Comparative Example 1)
25 Translucent sound absorbing panel (Example 2)
26 Translucent sound absorbing panel (Comparative Example 2)
27 Translucent perforated laminated sound absorbing plate (Examples 3, 4 and 5)
28 Translucent sound absorbing panel (Example 3)
29 Transparent double-sided tape 30 Open-cell elastic foam sound absorbing material 31 Fluorine resin thin film 32 Auxiliary sound absorbing material 33 Translucent sound absorbing panel (Example 4)

DETAILED DESCRIPTION OF THE INVENTION A translucent perforated laminated sound absorbing plate and a 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 of the present invention. A solid line indicates the sound source side transparent perforated resin plate 12, and a broken line indicates the counter sound source side transparent perforated resin plate 13. FIG. 2 is a schematic cross-sectional view taken along the line aa in FIG.
As is clear from FIGS. 1 and 2, the opening portions of the two transparent perforated resin plates 12 and 13 do not overlap. If there is an overlapping portion (a common opening portion), the sound absorption coefficient is greatly reduced.
The opening shapes of the sound source side transparent perforated resin plate 12 and the counter sound source side transparent perforated resin plate 13 in FIG. 1 are shown in a circular staggered arrangement, but are not particular to this shape, and are not limited to rectangles, squares, triangles, etc. But it doesn't matter. The range of 5% to 50% is practical for the aperture ratio, but the range of 10% to 40% is more preferable.
When the opening ratio exceeds 50%, the contact area of the non-opening portions of the two transparent perforated resin plates decreases, and a sound absorption phenomenon (sound absorption A) due to friction caused by vibration of two transparent perforated resin plates described later. ) And the sound absorption phenomenon (sound absorption B) based on the air gap resistance is reduced, so that the sound absorption characteristics are deteriorated. Furthermore, a large aperture ratio causes a problem in strength of the transparent perforated resin plate.
If the aperture ratio is less than 5%, not only the sound wave is largely reflected from the sound source side transparent perforated resin plate 12, but also the incident sound wave cannot easily penetrate the counter sound source side transparent perforated resin plate 13. The optical perforated laminated sound absorbing plate has a behavior similar to that in the case of two transparent polycarbonate plates having no holes as shown in FIG. 19 described later, and the sound absorbing characteristics deteriorate, so that it cannot be a sound absorbing plate.
The plate thickness of the transparent perforated resin plates 12, 13, 15, and 16 in the present invention is in the range of 1 mm to 5 mm, and more preferably in the range of 1.5 mm to 2.0 mm. If the plate thickness exceeds 5 mm, it is disadvantageous from an economical point of view even if the strength is sufficient. Moreover, when the plate | board thickness of a transparent perforated resin board is less than 1 mm, a difficulty arises in performing a strong problem and a weather resistance process. However, as described above, for applications in which translucency, watermarking property, 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.
The sound absorbing mechanism of the present invention is not a sound absorbing mechanism based on membrane vibration since a resin thin film is not used. In addition, although two perforated plates are used, there is no consistent opening portion in the perforated plates, and therefore it cannot be explained by a common sound absorption mechanism using perforated plates.
Further, when plate vibration, that is, sound waves collide with the plate-like body and the plate is temporarily twisted or bent, the plate is vibrated in an attempt to return according to the elasticity inherent in the plate. At this time, sound energy is converted into vibration energy and absorbed. However, the sound absorption rate by this sound absorption mechanism is generally not sufficient.
FIG. 19 is the same as in Example 3 and Example 4 except that two transparent polycarbonate plates with the same thickness as those used in this example and 1.5 holes are stacked as a sound absorbing plate. The result of the reverberation room method sound absorption rate measured in the manner described above is shown. The sound absorption coefficient of a sound absorption board in which two transparent polycarbonate plates without holes are stacked is about 0.4 although the sound absorption coefficient has a peak at 125 Hz, and the overall sound absorption coefficient is extremely low, so it cannot be a sound absorption board.
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, which is also shown in FIG.
As a result of intensive 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 thermal energy and absorbed. (Hereinafter referred to as sound absorption A)
Next, the sound wave that has entered from the perforated part on the sound source side passes through the gap between the two perforated plates and passes through the perforated part on the anti-sound source side. It is converted into thermal energy and absorbs sound. (Hereinafter referred to as sound absorption B)
Therefore, it is assumed 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 fluoroethylene resin thin film is sandwiched between two transparent perforated resin plates (Japanese Patent Application No. 2004-166491). In the process, the present invention has been achieved by finding a light-transmitting perforated laminated sound-absorbing plate having good sound-absorbing characteristics without using the resin thin film.

FIG. 9A is an explanatory diagram of an example of a translucent sound absorbing panel of 2000 mm × 1000 mm × 90 mm. A casing 22 is formed of the frame member 19 having four circumferences. P1, P2, P3, and P4 are surfaces of the housing 22 on the sound source side, for example, and are portions where a translucent perforated laminated sound absorbing plate is arranged. A transparent resin sound insulating plate 21 made of polycarbonate having a thickness of 5 mm is attached to the S1, S2, S3 and S4 surfaces on the side opposite to the sound source. In addition, the middle crosspiece 20 was provided in order to prevent the bending | flexion at the time of arranging a translucent perforated laminated sound-absorbing board on the surface at the sound source side. The frame member 19 and the intermediate rail 20 are formed by processing an aluminum plate having a thickness of 1 mm into a hollow prism shape, and the thickness of the hollow prism is 25 mm. FIG. 9B is a cross-sectional view taken along the line ee of FIG. The light-transmitting type laminated sound-absorbing plate of the example or the comparative example is arranged on the P1, P2, P3, and P4 surfaces of the casing 22, and the respective sound-absorbing performances are compared.
[Example 1]
The translucent perforated laminated sound absorbing plate 11 used in Example 1 is shown in FIG. The sound source side transparent perforated resin plate 12 is a staggered arrangement having a polycarbonate thickness of 1.5 mm, an opening diameter of 10 mm, an opening center distance (pitch) of 16 mm, and an opening angle of 60 degrees. 35% was used.
Similarly, the counter sound source side transparent perforated resin plate 13 is a staggered pattern having 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 of 60 degrees. An array with an aperture ratio of 13% was used. FIG. 2 is a cross-sectional view taken along the line aa in FIG.
Set the two transparent perforated resin plates 12 and 13 so that the respective opening portions do not overlap, that is, there is no common through-opening portion as shown in the conceptual diagrams of FIGS. 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 casing 22 of FIG. 9 (arranged on the P1, P2, P3, and P4 surfaces of FIG. 9). Panel 23 was obtained. The result of measuring the sound absorption coefficient of the reverberation chamber method in accordance with JIS A1409-1998 for the translucent sound absorbing panel 23 is shown in Example 1 of FIG.
(Comparative Example 1)
The translucent perforated laminated sound absorbing plate 14 used is shown in FIG. The sound source side transparent perforated resin plate 12 and the counter sound source side transparent perforated resin plate 13 are the same as those in the first embodiment, but as is apparent from FIGS. 3 and 4, the sound source side transparent perforated resin plate 13 12 and the hole position of the counter sound source side transparent perforated resin plate 13 are the same. Therefore, it has a through-opening (opening ratio 13%) based on the counter sound source side transparent perforated resin plate 13 having a small hole diameter.
This translucent perforated laminated sound absorbing plate 14 was placed on a housing 22 as shown in FIG. The result of measuring the sound absorption rate of the reverberation chamber method in accordance with JIS A1409-1998 is shown in Comparative Example 1 in FIG.
By comparing the sound absorption coefficient of the reverberation chamber method of Example 1 and Comparative Example 1 of FIG. 17, a common through-opening portion is not generated in the 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.
[Example 2]
The translucent perforated laminated sound absorbing plate 17 used is shown in FIGS. The sound source side transparent perforated resin plate 15 is a staggered arrangement having a polycarbonate thickness of 1.5 mm, an opening diameter of 3 mm, an opening center distance (pitch) of 8 mm, and an opening angle of 60 degrees. 13% was used. Further, the non-sound source side transparent perforated resin plate 16 also has the same specifications as the sound source side transparent perforated resin plate 15.
As shown in the conceptual diagrams of FIGS. 5 and 6, the two transparent resin plates 15 and 16 are set so that the respective opening portions do not overlap, that is, there is no common through-opening portion. A translucent perforated laminated sound absorbing plate 17 was obtained by fastening both ends on the long side with tape.
The translucent perforated laminated sound absorbing plate 17 is placed on the housing 22 as shown in FIG. 12 (arranged on the P1, P2, P3, and P4 surfaces in FIG. 9) to form a translucent sound absorbing panel 25. . The result of measuring the sound absorption rate of the reverberation chamber method in accordance with JIS A1409-1998 is shown in Example 2 of FIG.
(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 the second embodiment, but as is clear from FIGS. 7 and 8, the sound source side transparent perforated resin plate 15 15 and the hole position of the counter sound source side transparent perforated resin plate 16 are the same. Therefore, the common through-opening ratio is 13% corresponding to the transparent resin plates (15 and 16) each having a diameter of 3 mm.
This translucent perforated laminated sound absorbing plate 18 was placed on a housing 22 as shown in FIG. About this translucent sound absorption panel 26, the result of having measured the reverberation room method sound absorption rate according to JIS A1409-1998 similarly to the above is shown in the comparative example 2 of FIG.
By comparing the sound absorption coefficient of the reverberation chamber method of Example 2 of FIG. 18 and Comparative Example 2, it is compared with Example 1 using the translucent perforated laminated sound absorbing plate (11 and 14) of the combination of φ10 mm and φ6 mm. As in the case of Example 1, in the light transmission type laminated sound absorbing plates 17 and 18 in which two holes of φ3 mm and φ3 mm are laminated, a common opening portion (through opening portion) is not generated. It is clear again that the sound absorption coefficient is greatly improved by laminating.
[Example 3]
The translucent perforated laminated sound absorbing plate 27 used will be described with reference to the conceptual diagrams shown in FIGS. The sound source side transparent perforated resin plate 15 and the counter sound source side transparent perforated resin plate 16 have an opening diameter of 3 mm, which is the same as that used in Example 2. 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. Further, by using a double-sided tape 29 having a width of 5 mm, two transparent perforated resin plates are attached by attaching two portions in the width direction of the laminated plate along the longitudinal direction of the laminated plate as shown in FIGS. 15 and 16 were fixed to each other to obtain a translucent perforated laminated sound absorbing plate 27.
As shown in the conceptual diagram of FIG. 15, the translucent perforated laminated sound absorbing plate 27 is placed on the housing 22 (arranged on the P1, P2, P3, and P4 surfaces of FIG. 9). Panel 28 was designated. The results of measuring the sound absorption coefficient of the reverberation chamber method in accordance with JIS A1409-1998 for this translucent sound absorbing panel 28 are shown in Example 3 of FIGS.
As shown in FIG. 14 and FIG. 15, two portions of the two transparent perforated resin plates 15 and 16 are fixed with a double-sided tape 29, so that FIG. As shown in FIG. 5, improvement in sound absorption characteristics is recognized particularly in the frequency range of 315 Hz to 1000 Hz.
The reason why the sound absorption characteristics are improved is that the sound absorption B described above by fixing with double-sided tape, that is, the sound wave that has entered from the perforated part on the sound source side passes through the gap between the two perforated plates and opens the hole on the opposite sound source side. Although it passes through the portion, it is assumed that the void resistance at this time is increased.
[Example 4]
The translucent perforated laminated sound absorbing plate used is the same as that of Example 3 shown in FIG. That is, two transparent perforated resin plates 15 and 16 having a hole diameter of Φ3 mm and a thickness of 1.5 mm are overlapped so that the opening portions do not overlap at all, and further, a double-sided tape 29 having a width of 5 mm is used. The transparent perforated resin plates 15 and 16 are fixed to each other as shown in FIG.
The translucent sound absorbing panel 33 used is shown in FIG. An open-cell elastic foam sound absorbing material 30 having a thickness of 25 mm and a height of 90 mm is formed on the inner side of the frame member 19 of the housing 22 and on one side of the middle rail 20 (lower side in the case of a vertical soundproof wall panel). The auxiliary sound-absorbing material 32 was wrapped with a 21 μm fluorine-based resin thin film 31.
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 air can flow between the front and back surfaces of the material. It is a foam having a structure (open cell) that can pass through, and sound waves (vibrating air particles) receive frictional resistance that passes through the pores and are converted into thermal energy and absorbed.
The result of measuring the sound absorption coefficient of the reverberation chamber method in accordance with JIS A1409-1998 is 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 absorption characteristics at a frequency of 500 Hz or more.
[Example 5]
The translucent sound-absorbing panels used in Examples 1 to 4 and Comparative Examples 1 and 2 were all in the case of 2000 mm × 1000 mm × 90 mm shown in FIG. 9, that is, the air layer was 90 mm.
In this embodiment, a light-transmitting sound absorbing panel (not shown) having a size of 2000 mm × 1000 mm × 50 mm, that is, an air layer of 50 mm is manufactured, and the bonded light-transmitting perforated laminate shown in FIG. An open cell elastic foam sound absorbing material 30 encased in a fluorine resin thin film 31 having a length of 50 mm in the same manner as that shown in FIG.
With respect to this translucent sound-absorbing panel (not shown, but the same structure as that shown in FIG. 16), the result of measuring the reverberation chamber method sound absorption rate in accordance with JIS A1409-1998 is compared with the graph of Example 4 in FIG. Show.
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 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 induction of static electricity or the like. In the case of the sound absorbing plate of the present invention, there is no resin thin film, but only a transparent resin resin plate made of polycarbonate, so that the dirt caused by the adsorption of fine exhaust gas dust caused by static electricity Is alleviated.

By using the resin-made translucent perforated laminated sound absorbing plate, a translucent perforated laminated sound absorbing plate and a translucent sound absorbing panel that do not reflect radio waves and have excellent translucency and see-through properties can be obtained.
In addition, for applications where translucency, see-through, and radio wave reflection are not a problem, the use of a metal-made perforated laminated vibration-absorbing sound board makes it possible to obtain a perforated laminated structure with excellent heat resistance, fire resistance, wind pressure resistance, etc. There is a possibility of being used for a vibration sound absorbing plate and a sound absorbing panel.

Claims (3)

In a translucent perforated laminated sound absorbing board in which two transparent perforated resin plates are laminated, the thickness of the two transparent perforated resin plates is 1 mm to 5 mm and the hole diameter is 1 mm to 10 mm. The rate is in the range of 5% to 50%, and the two transparent perforated resin plates are laminated without using a transparent resin thin film, and at least one location of the two transparent perforated resin plates the mutually fixed through an adhesive, by improving the adhesion of the two transparent AnaHiraki resin plate, to improve the sound absorption characteristics, and a common opening portion in the stacked state free Kushida A translucent perforated laminated sound absorbing plate characterized by the above. A transparent resin sound-insulating plate is disposed on the sound source side and on the opposite sound source side of the translucent perforated laminated sound-absorbing plate according to claim 1, and air is retained by using a frame member and an intermediate rail. A translucent sound-absorbing panel characterized in that a layer is formed. It is characterized by using a soft fiber-based porous sound absorbing material or an open-cell elastic foam sound absorbing material lined with waterproofing as an auxiliary sound absorbing material on the inside of the frame member and the middle rail of the translucent sound absorbing panel. The translucent sound absorbing panel according to claim 2 .

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