JP2840130B2 - Sound absorber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sound absorber mainly composed of a non-porous or low-porous film material.

(Prior art) Conventional sound absorbers used for soundproof walls and the like include porous materials such as glass wool and rock wool that absorb sound due to voids in the material, and vinyl sheets and canvases that absorb sound in the resonance frequency range due to resonance vibration. They are broadly classified into membrane materials and perforated materials such as perforated gypsum boards that absorb sound in the resonance frequency range determined by the pitch and thickness of the holes.

Of these, the most frequently used are porous materials with good sound absorption performance, and other porous materials and membrane materials are used alone because they absorb sound only in the resonance frequency range and have a low sound absorption coefficient. There are few things. In particular, a film-like material is often used as a coating material for preventing scattering of fibers such as glass wool or rock wool which is a porous material, and in such a case, a sound absorbing property of the porous material is not damaged. Thickness of about 20 μm is common.

By the way, recently, there is a problem that a scene outside the road is not visible due to being blocked by a soundproof wall, a sunshine right is impaired by the soundproof wall, and a translucent sound absorbing body is required. However, since the conventional porous material is non-translucent, even if a transparent plastic plate is used as a sound insulating plate used in combination with the sound absorber, the entire soundproof wall will be non-translucent. . Also, if a transparent sheet is used among the film-like materials, translucency can be obtained, but as described above, this material has a problem that sufficient sound absorption cannot be obtained because the sound absorption coefficient is extremely low.

(Problems to be Solved by the Invention) The present invention has been completed for the purpose of solving the above-mentioned conventional problems and providing a sound absorber having both a light transmitting property and a sound absorbing property.

(Means for Solving the Problems) According to the present invention made to solve the above problems, a porous material is arranged on both sides of a film material at a distance that the film material can contact by vibration. It is characterized by the following.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

In FIG. 1, (1) is a film material, and (2) is a porous material arranged on both sides thereof. It is necessary that the film material (1) has low rigidity itself and exhibits elasticity when tensioned. For example, a synthetic resin film such as polyvinyl fluoride, polyvinyl chloride, or polyethylene is used. Used. Also, as the film thickness increases, the rigidity of the film material increases and film vibration due to sound waves becomes difficult to occur, and as a result, the sound absorption coefficient decreases, and conversely, if it is too thin, the strength decreases and it is broken. To make it easier
It is preferably about 0.01 to 2 mm.

On the other hand, as the perforated material (2), meshes made of various materials such as glass, vinylon, aluminum, iron and the like or meshes such as expanded metal, or through holes of various shapes formed on inorganic plates, organic plates, metal plates and the like A perforated plate is used. Here, a gypsum board, a calcium silicate board or the like is used as an inorganic board, a polyvinyl chloride board, a polycarbonate board or the like is used as an organic board, and an aluminum board, an iron board or the like is used as a metal board. The porosity of the perforated material (2) is preferably at least 40%, particularly preferably at least 80%, in order to improve the sound absorption and secure the light transmission. The size of the hole is 1-50
mm is preferable. If the holes are too large, the function of adjusting the vibration of the film material (1) is reduced, and the sound absorption coefficient is also reduced. Although there is considerable flexibility in the shape and dimensions of the holes, since the porous material (2) is disposed on both sides of the membrane material (1), the porous materials (2),
It is desirable that the shape and arrangement of the holes in (2) be the same in order to improve the sound absorption and the light transmission.

The porous material (2) is disposed between the film material (1) and the film material (1) at a distance such that the film material (1) can come into contact with vibration. As a result, in the sound absorber of the present invention, the vibration of the film material (1) due to the sound wave is attenuated by the contact with the perforated material (2), and a high sound absorption coefficient is obtained. As described above, it is necessary that the film material (1) can be vibrated by sound waves. Therefore, when a panel-shaped sound absorber is used, only the four sides are adhered as shown in FIG. It is desirable that only partial bonding be performed. If the entire surface is adhered to the inside, the film material (1) cannot vibrate, and the sound absorption coefficient decreases. In the case of partial bonding, a spacer may be interposed only in that part. The film material (1) may be tensioned to such an extent that it can be vibrated by a sound wave, but it is more preferable that the film material is loosely stretched.

FIG. 1 shows the basic structure of the sound absorber of the present invention, but the sound absorber of the present invention may be used as a multilayer.

(Operation) The sound absorber of the present invention configured as described above can attenuate the vibration of the film material (1) generated by the sound wave by contact with the perforated material (2) arranged on both sides thereof. As described in the next embodiment, it is possible to obtain excellent sound absorbing properties. In addition, the film-like material (1) can be made transparent or light-transmitting by making it thin enough to be light-transmitting. Can be provided. For this reason, the external scenery can be seen through the hole of the perforated material (1), and sunlight can be secured. Further, the peak of the sound absorption coefficient can be easily set by changing the thickness of the film material (2) or the thickness of the back air layer, and necessary sound absorption characteristics can be provided.

(Example) On both sides of three types of polyvinyl chloride films having a film thickness of 0.024 mm, 0.1 mm, and 1 mm, aluminum expanded metal (aperture ratio: 90%) was attached by bonding only the peripheral frame portion.
Example products of o.1, No.2 and No.3 were manufactured. As a comparative example, a sound absorber made of only a polyvinyl chloride film having a thickness of 0.024 mm was produced.

As a result of measuring the normal incidence sound absorption coefficient of these four types of sound absorbers, the frequency characteristics as shown in the graph of FIG. 2 were confirmed.

As is clear from this graph, the sound absorber of the present invention can exhibit an excellent sound absorption coefficient over a wide frequency range, and the frequency at which the sound absorption coefficient shows a peak can be freely changed by the film thickness of the film material. Can be.

(Effects of the Invention) As described above, the present invention is excellent in sound absorption, can freely change the peak of the sound absorption coefficient, can have a light-transmitting property, and the soundproof wall prevents sunlight. This has many advantages, such as avoiding the need to do so and being able to make the whole lightweight and inexpensive. Therefore, the present invention greatly contributes to industrial development as a sound absorber that has eliminated the conventional problems.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a sound absorber of the present invention, and FIG. 2 is a graph showing the sound absorption coefficient of the sound absorber of the embodiment. (1): film material, (2): porous material.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G10K 11/168

Claims (2)

(57) [Claims] 1. A sound absorber comprising a perforated material disposed on both sides of a film material at a distance from which the film material can come into contact by vibration. 2. The sound absorber according to claim 1, wherein the film material is a synthetic resin film having a thickness of 0.01 to 2 mm, and the perforated material has a porosity of 40% or more.