JP2001065077A - Sound absorbing panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perforated plate type sound absorbing panel low in cost with a high sound absorbing coefficient in a low frequency sound area of 100-500 Hz. SOLUTION: This sound absorbing panel 1a is formed by forming a large number of sound absorbing holes 3 in a wood panel body 2 in the state of piercing the front and rear faces, and bonding a wood sound absorbing membrane plate 4 with a thickness of 0.2-3.0 mm to the surface of the panel body 2 to close the sound absorbing holes 3. The parts, covering the sound absorbing holes 3, of the sound absorbing membrane plate 4 are vibrated in-plate (membrane) by external sound energy to absorb sound. A sound absorbing coefficient in a low sound area is thereby heightened as the whole panel. A sound absorbing interior material of excellent appearance with the invisible sound absorbing holes can be obtained since the surface of the perforated panel body 2 is formed of the wood sound absorbing membrane plate 4 to close the sound absorbing holes 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing panel of a sound absorbing interior material used as a wall plate or a ceiling plate of a building.

[0002]

2. Description of the Related Art A perforated plate formed by penetrating a large number of sound-absorbing holes in a rectangular panel body made of a plywood or a non-combustible material as a sound-absorbing panel that positively absorbs noise-like sounds inside and outside a room. The type is often used. In this perforated plate type sound absorbing panel, the frequency band of sound that can effectively absorb sound is selected by selecting and setting the material of the panel body, the size, number, and arrangement pattern of the sound absorbing holes. The perforated plate-type sound absorbing panel is used as a single panel body as a wall plate or a ceiling plate, or with a sound absorbing material such as glass wool or rock wool disposed on the back surface of the panel body. In the sound absorbing panel in which the sound absorbing material is arranged on the back surface of the panel body, sound energy incident from outside to the sound absorbing hole of the panel body is consumed by the sound absorbing material as heat energy, and the sound absorbing rate is increased.

Such a perforated plate type sound absorbing panel has a simple structure, is low in material cost, and is easy to mass-produce, so that it can be used as an inexpensive sound absorbing interior material.
Because of its superiority in the middle and high frequency range exceeding Hz, it has been awarded as a sound-absorbing interior material for wall boards and ceiling boards in gymnasiums and music rooms.

[0004]

The sound-absorbing panel of the perforated plate type has an excellent sound absorption coefficient for sounds in the middle and high frequency ranges, but has a low sound absorption rate for sounds in the low frequency range lower than 500 Hz. Is much lower than the sound absorption in the high range,
In particular, the sound absorption coefficient in the low sound range of about 100 Hz to 250 Hz is low, and the sound absorption effect in this low sound range cannot be expected very much. For example, vehicle noise around the highway is 100
Although it is generated in a wide range of frequencies up to 5000 Hz, it has a poor sound absorbing effect on noise in a low frequency range, and there is a demand for the development of an inexpensive perforated plate type sound absorbing panel for noise pollution in a low frequency range.

The existing sound-absorbing panels are effective in places where high-frequency sounds are actively generated, such as gymnasiums and music rooms. However, such panels are used in nursing homes, lobby of public facilities, and study rooms of general households. It is not necessarily effective in places where very high frequency sounds (noise) are not generated. In other words, in places such as nursing homes where high-frequency sounds are less actively generated, low-frequency sounds such as car noise, home appliances, and human voices are more worrisome than high-frequency sounds. In such a place, a sound absorbing panel having a high sound absorbing rate in the low range and an average sound absorbing rate in the entire range from the low range to the high range is more appropriate than the sound absorbing panel having a high sound absorbing rate in the high range. Many. However, it is difficult to develop an inexpensive perforated plate type sound absorbing panel that has an average sound absorption coefficient in the entire range from the low range to the high range. That is the current situation.

Further, in order to increase the sound absorption coefficient in the low sound range of the perforated plate type sound absorbing panel, a thick sound absorbing member such as a nonwoven fabric having an excellent sound absorption coefficient in the low sound range is superposed on the panel body of the sound absorbing panel, Although the sound absorbing holes of the main body are filled, this makes the whole panel complicated and causes a problem that the size is increased and the cost is increased, which is not practical.

An object of the present invention is to provide a perforated plate type inexpensive sound absorbing panel having a high sound absorption coefficient in a low sound range.

[0008]

A technical means for achieving the above object of the present invention is to provide a panel body having a plurality of sound absorbing holes penetrating through the front and back surfaces in a predetermined arrangement, and being integrally bonded to the surface of the panel body. Structure having a thickness of 0.2 to 3.0 mm of a wood-based sound-absorbing film plate that closes the openings on the panel surface side of the plurality of sound absorbing holes and that absorbs sound by vibrating the plate with sound energy from the outside at the portion that closes the sound absorbing holes. It is characterized by.

The panel body is a wooden veneer board, a plywood board, a non-combustible board, or the like. The wood-based sound-absorbing membrane plate adhered to the surface of the panel body is made by cutting a thin piece of raw wood into a sheet. desirable. This wood-based sound-absorbing membrane plate is a wood sheet having a thickness of 0.2 to 3.0 mm. When this is adhered to the surface of the panel body, the opening on the surface side of the sound-absorbing hole is closed by the sound-absorbing membrane plate, and the sound-absorbing membrane plate is closed. The portion that closes the sound absorbing hole uses the space of the sound absorbing hole to cause plate vibration (membrane vibration) with sound energy from the outside, and the plate vibration absorbs (absorbs) part of the sound energy in the low frequency range. The sound absorption coefficient in such a low sound range becomes favorable when the thickness of the wood-based sound absorbing film plate is in the range of 0.2 mm or more and 3.0 mm or less. In addition, the whole surface of the sound-absorbing panel is formed by the wood-based sound-absorbing film plate by bonding the wooden sound-absorbing film plate to the entire surface of the panel main body, and the panel surface has good appearance without holes such as sound-absorbing holes. Becomes

The above-mentioned wood-based sound-absorbing membrane plate is not limited to a single wood-based veneer, but may have a plywood structure in which a plurality of wood-based thin plates (single veneers) are laminated and integrated when the thickness is increased to nearly 3 mm. The use of plywood is equivalent to the present invention.

Further, according to the invention of claim 3 of the present invention, a reinforcing paper which does not hinder the vibration of the sound absorbing film plate is adhered to the back surface of the wooden sound absorbing film plate, and the sound absorbing film plate is connected to the panel through the reinforcing paper. It is characterized by being adhered to the surface of the main body. By doing so, the fragile wood-based sound-absorbing membrane plate is reinforced by the reinforcing paper so as not to be easily torn, and can be adhered to the panel body in a good state, and the quality of the sound-absorbing panel is stabilized.

According to a fourth aspect of the present invention, there is provided a sound absorbing material which absorbs sound energy from a plurality of sound absorbing holes of the panel body and absorbs the sound energy on a back surface of the panel body, and a box-shaped outer material surrounding the sound absorbing material. Is fixed.

Further, the invention according to claim 4 of the present invention has a wooden panel body having a plurality of heavenly sound-absorbing holes perforated from the back side to the front side in a predetermined arrangement.
The top plate of the sound-absorbing hole left unpenetrated on the panel surface side of the panel body is a wood-based sound-absorbing film plate having a thickness of 0.2 to 3.0 mm that absorbs sound by vibrating the plate with external sound energy. There is a feature.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG.

A sound absorbing panel 1a according to a first embodiment shown in FIGS. 1 to 3 has a plurality of sound absorbing holes 3 formed in a panel body 2;
A wood-based sound-absorbing membrane plate 4 having a predetermined thickness t is bonded and fixed to the surface of the panel body 2. The panel main body 2 is a wood-based veneer, a plywood, a non-combustible board, or the like, similar to the conventional perforated panel type panel main body. It is formed in various sizes, numbers, and arrangement patterns. The feature of the present invention is that the surface of the panel main body 2 is formed in a sheet shape having the same area as the surface,
The sound absorbing film 3 having a thickness of 0.2 to 3.0 mm is bonded to close the sound absorbing hole 3 on the surface of the panel main body 2 and the sound absorbing hole 3 is hidden from view.

The material of the wood-based sound-absorbing membrane plate 4 is desirably a relatively good-grained wood with good appearance, such as Chinese china, tamasa, cherry, oak, and hippo. The production of the wood-based sound-absorbing membrane plate 4 is performed by rotating a raw log and continuously cutting the outer peripheral portion of the log into a sheet having a predetermined thickness t. Further, a reinforcing paper 5 is adhered to the back surface of the sheet-shaped sound absorbing film plate 4 as necessary, and the sound absorbing film plate 4 is adhered and fixed to the surface of the panel main body 2 via the reinforcing paper 5. The reinforcing paper 5 is thinner than the sound absorbing film plate 4 and does not prevent the vibration of the sound absorbing film plate 4 to be described later. By adhering the reinforcing paper 5 to the sound absorbing film plate 4, the single sound absorbing film plate 4 is less likely to be torn and the work of adhering to the panel main body 2 is facilitated, and the quality after adhesion is favorably stabilized.

Depending on the material and thickness t of the sound absorbing film plate 4, it is also possible to directly bond the single sheet of the sound absorbing film plate 4 to the panel body 2 without bonding the reinforcing paper 5. The sound-absorbing membrane plate 4, the reinforcing paper 5, and the panel body 2 are bonded to each other with an adhesive made of a 100% non-formaldehyde natural material, so that the sound-absorbing panel 1 is installed on a wall or ceiling. It is desirable to make the living environment safe for the human body.

By bonding the wood-based sound-absorbing film plate 4 having a thickness t of 0.2 mm or more and 3.0 mm or less to the surface of the panel body 2, the plurality of sound-absorbing holes 3 are opened on the panel surface side. 4, the portion 4 'of the sound absorbing film plate 4 which closes the sound absorbing hole 3 can vibrate in the thickness direction. Actually, when sound energy is externally applied to the portion 4 ′ of the sound absorbing film plate 4 which closes the sound absorbing hole 3, the hole closing portion 4 ′ of the sound absorbing film plate 4 is moved by the applied sound energy to the air layer in the sound absorbing hole 3. Using plate vibration (membrane vibration)
Then, a part of the sound energy is consumed and the sound is absorbed by the plate vibration. Such plate vibration type sound absorption is efficiently performed for sound energy in a low sound range, and the thickness t of the sound absorbing film plate 4 is reduced.
Has been found to be effective within the range of 0.2 to 3.0 mm, and in particular, stably and reliably within the range of 0.2 to 0.5 mm. Further, the panel body 2 itself vibrates and absorbs sound due to plate vibration with sound energy from the outside, and the sound absorbing hole 3 of the panel body 2 also absorbs sound energy by a resonator type sound absorbing method. The sound absorbing panel 1a in which the wood-based sound absorbing film plate 4 is adhered to the surface of the panel main body 2 by the composite sound absorbing effect by such various methods has a high sound absorption coefficient in a low sound range, and also in a whole sound range from a low sound range to a high sound range. Experiments have shown that the average does not vary much. The results of this experiment will be described with reference to various experimental data of Examples described later.

Further, a wood-based sound absorbing film plate 4 is adhered to the surface of the panel body 2 and the suction holes 3 on the surface of the panel body 2 are hidden by the sound absorbing film plate 4, so that the surface of the sound absorbing panel 1a has no holes. The sound-absorbing panel 1a used as a sound-absorbing interior material is made of a good wood-based sound-absorbing membrane plate 4 having a good appearance. The thickness t of the wood-based sound absorbing membrane plate 4 is 0.2 m.
If m is smaller than m, the sound absorption effect in the low-frequency range due to the above-described plate vibration is reduced, and the sound absorption hole 3 is seen through from the surface of the sound absorption panel 1a because it is too thin to be transparent, which is not preferable in appearance. . Conversely, if the thickness t exceeds 3 mm, the vibration of the board is not performed well, and the sound absorbing effect in the low frequency range is deteriorated, and the sound absorbing panel 1a is simply a plywood board without sound absorbing holes. Therefore, the thickness t of the wood-based sound absorbing membrane plate 4 is 0.2 to 3.0 mm.
It is practically necessary to define the thickness within the range of 0.2 to 0.5 mm. The thickness regulation of such a wood-based sound absorbing membrane plate is the same in the following embodiments.

The sound absorbing panel 1b shown in the second embodiment of FIG. 4 has a plywood-structured wood-based sound absorbing film plate 4a adhered to the surface of the panel body 2. The wood-based sound-absorbing membrane plate 4a having a plywood structure is, for example, a laminate of two wood-based membrane plates 4b and 4c, which are bonded and integrated.
The total plate thickness t of c is regulated to 0.2 to 3.0 mm, preferably 0.2 to 0.5 mm. As shown in FIG. 5, if two wood-based membrane boards 4b are stacked such that the grain 10 of one wood-based membrane board 4b and the grain 11 of another wood-based membrane board 4c are orthogonal to each other, The sound-absorbing membrane plates 4a in which the two sheets are reinforced with each other and integrated are hardly broken. Therefore, the wood-based sound-absorbing membrane plate 4a having the plywood structure may be directly bonded to the panel main body 2 without reinforcing with reinforcing paper or the like.
If the thickness t is regulated, the wood-based sound absorbing film plate 4a having such a plywood structure also vibrates with sound energy urged from the outside, and exhibits the same sound absorbing effect as the sound absorbing panel of FIG.

The sound absorbing panel 1c of the third embodiment shown in FIG. 6 is a panel body 2 of the sound absorbing panel of FIG. 1 or FIG.
Sound absorbing material 6 such as glass wool and rock wool on the back of
A box-shaped outer surrounding member 7 that surrounds and accommodates the sound absorbing member 6 is fixed. Styrofoam is suitable for the outer cover 7. When sound energy from the sound absorbing hole 3 of the panel body 2 is incident, the sound absorbing material 6 absorbs sound (porous sound absorbing) by consuming a part of the sound energy as heat energy. This sound absorbing material 6
And the sound absorption effect of the panel body 2 side,
An average sound absorption coefficient is obtained stably from the bass range to the treble range.

In the sound absorbing panel 1d of the fourth embodiment shown in FIG. 7, the sound absorbing hole 3 is formed at a predetermined depth from the back surface of the wooden panel body 2 without penetrating to the panel surface. The top plate portion left unpenetrated on the panel surface side is a wood-based sound absorbing film plate 4d that vibrates with sound energy. The thickness t of the wood-based sound absorbing membrane plate 4d is 0.2 to 3.0 mm. By simultaneously forming the wood-based sound-absorbing membrane plate 4e when the sound-absorbing holes 3 are formed in the wood-based panel main body 2 as described above, it is possible to save the labor of separately manufacturing and adhering the separate panel body and the sound-absorbing membrane plate. .

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Experimental results in which three types of sound absorbing panels are installed in a reverberation room and the sound absorption coefficient and reverberation time of each type of sound absorbing panel are measured will be described. As shown in FIG. 8, a plurality of bricks 13 are installed on a floor 12 of a reverberation room, and a plurality of the same type of sound absorbing panels 14 are arranged on the bricks 13.
Is measured, and the reverberation time of the reverberation room is measured. A case in which a sound absorbing panel 1c similar to that shown in FIG. 6 is used as the sound absorbing panel 14 is referred to as a product C of the present invention, and a conventional structure in which the sound absorbing film plate 4 is omitted from the panel main body 2 in FIG. A sound-absorbing panel equivalent to a conventional product is referred to as a soundproof plate B, and a sound-absorbing panel equivalent to a conventional product in which the sound-absorbing material 6, the surrounding material 7, and the sound-absorbing film plate 4 are omitted from the panel body 2 in FIG. Table 1 shows measurement data obtained by measuring the sound absorption coefficient of each sound absorbing panel.

[0024]

[Table 1]

FIG. 9 shows a graph of the measured data of Table 1. As shown in FIG. 9, the perforated plate A has a high sound absorption coefficient in the high sound range, and the sound absorption coefficient decreases from the middle sound range to the low sound range. The sound absorbing plate B has a high sound absorption coefficient from the high sound range to the middle sound range, but the sound absorption coefficient is greatly reduced in the low sound range. On the other hand, the product C of the present invention has a low sound absorption coefficient in the entire sound range from the low sound range to the high sound range but is uniform, and in particular, the sound absorption coefficient in the low sound range of 100 to 200 Hz has the perforated plate A or the sound absorption plate. It turns out that it is several times higher than B. Therefore, the product C of the present invention can be used as an unprecedented qualified sound absorbing panel in a place where low-frequency noise such as automobile noise is generated. The theoretical description of the uniform sound absorption coefficient distribution in the entire sound range of the product C of the present invention is not sufficient at the present time, and thus will be omitted.

Next, Table 2 shows measurement data obtained by measuring the reverberation time of each of the above sound absorbing panels, and a graph thereof is shown in FIG.

[0027]

[Table 2]

The reverberation time of an empty room in Table 2 is the reverberation time when the reverberation room is removed from the sound absorbing panel to make the room empty. As is clear from FIG. 10, the reverberation time of the product C of the present invention is averaged over the entire range from the low range to the high range, and is particularly shorter than the reverberation time of the perforated plate A or the sound absorbing plate B in the low range. Even from this, it can be seen that the sound absorption coefficient of the product C of the present invention is high in the low frequency range.

[0029]

According to the present invention, a wooden sound-absorbing film plate is formed on a surface of a panel body of a perforated plate having a plurality of sound-absorbing holes in a state where the sound-absorbing holes are closed, and this wooden sound-absorbing film plate is removed from the outside. By making the board vibrate with the sound energy of the sound and absorbing the sound, the sound absorption rate of the entire sound absorbing panel becomes higher than the sound in the low sound range. An inexpensive perforated plate-type sound absorbing panel excellent in sound absorbing effect can be provided. In addition, by forming the surface of the panel body having the sound absorbing hole with a wood-based sound absorbing film plate, the sound absorbing hole on the surface of the sound absorbing panel is hidden by the sound absorbing film plate, so that the sound absorbing panel looks better, and is used as a sound absorbing interior material. High value-added products can be provided.

[Brief description of the drawings]

FIG. 1 is a side view including a partial cross section of a sound absorbing panel according to a first embodiment.

FIG. 2 is a partially enlarged sectional view of the sound absorbing panel of FIG. 1;

FIG. 3 is a partially enlarged plan view of the sound absorbing panel of FIG. 1;

FIG. 4 is a partial cross-sectional view of a sound absorbing panel showing a second embodiment.

FIG. 5 is a partial perspective view of a wood-based sound absorbing membrane plate in the sound absorbing panel of FIG. 4;

FIG. 6 is a side view including a partial cross section of a sound absorbing panel showing a third embodiment.

FIG. 7 is a side view including a partial cross section of a sound absorbing panel according to a fourth embodiment.

FIG. 8 is a side view of the sound absorbing panel for explaining the sound absorbing coefficient measurement experiment.

FIG. 9 is a graph based on experimental data of sound absorption coefficients of a product of the present invention and a conventional product.

FIG. 10 is a graph based on experimental data of reverberation time of a product of the present invention and a conventional product.

[Explanation of symbols]

 1a to 1d sound absorbing panel 2 panel body 3 sound absorbing hole 4 wooden sound absorbing film plate 4a to 4d wooden sound absorbing film plate 5 reinforcing paper 6 sound absorbing material 7 outer material

Claims (5)

[Claims] A panel body having a plurality of sound absorbing holes penetrating through the front and back surfaces in a predetermined arrangement; a panel body integrally bonded to a surface of the panel body to close openings of the plurality of sound absorbing holes on the panel surface side; Thickness 0.2 that absorbs sound by vibrating the plate with sound energy from the outside at the closing part
And a wood-based sound-absorbing membrane plate having a thickness of about 3.0 mm. 2. The sound-absorbing panel according to claim 1, wherein the wood-based sound-absorbing membrane plate is a plywood in which a plurality of wood-based membrane plates are laminated and integrated. 3. A sound-absorbing membrane plate is bonded to a back surface of a wood-based sound-absorbing membrane plate with a reinforcing paper that does not hinder vibration of the sound-absorbing membrane plate, and the sound absorbing membrane plate is bonded to a surface of the panel body via the reinforcing paper. The sound absorbing panel according to claim 1. 4. A sound absorbing material which absorbs sound energy by absorbing sound energy from a plurality of sound absorbing holes of the panel body and a box-shaped outer material surrounding the sound absorbing material are fixed to a back surface of the panel body. Item 2. The sound absorbing panel according to Item 1. 5. A wooden panel body having a plurality of heavenly sound-absorbing holes arranged in a predetermined arrangement from a back side to a front side without being penetrated, and the panel body side of the panel body is not penetrated. 2. The sound-absorbing panel according to claim 1, wherein the top plate portion of the sound-absorbing hole is a wood-based sound-absorbing film plate having a thickness of 0.2 to 3.0 mm which absorbs sound by vibrating the plate with sound energy from the outside.