JP2000046283A - Sound-proofing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound-proofing material to save a space (thickness) and provide a high sound proofing effect at a low area. SOLUTION: A sound absorbing member body 3a is formed of foamed resin and has a cavity part 5 opened to a contact surface 3s brought into contact with a wall surface. A skin layer 3b is formed integrally with an inner wall surface to partition a cavity part 5 and a skin layer 3b to form a sheet-form sound absorbing member 3. A sound shielding member 4 is arranged on the outer surface of the sound absorbing member 3 on the opposite side to the skin layer 3b. A groove 6 serving as a partitioning means that a part of the skin layer of the part forms a vibration film 3c independent from other part is formed in an inner wall surface to partition the cavity part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof material mounted on a wall of a pipe or the like.

[0002]

2. Description of the Related Art In recent years, in general houses, toilets are generally installed on the second floor, and in some houses, bathrooms and mini-kitchens are also increasing. In addition, in apartment buildings and the like, households are formed on the first and second floors, and water-related facilities such as kitchens, toilets, and bathrooms are installed on each floor.

In such pipes of water-related facilities, radiated sound is often a problem. As a countermeasure, soundproofing materials having a sound insulation layer and a sound absorption layer are installed around pipes and hoses. The sound insulation layer reflects sound radiated from the inside of the wall surface to the inside of the pipe or the inside of the wall surface, and is made of a soft resin such as PVC having a predetermined density and a predetermined thickness.

[0004] The sound absorbing layer is provided between the sound insulating layer and the wall surface, and is generally a porous sound absorbing member using a fibrous material such as glass wool, or a diaphragm sound absorbing member using a thin film or thin plate.

[0005]

However, in the conventional soundproofing material composed of the sound absorbing layer and the sound insulating layer, the sound absorbing layer is in close contact with the entire wall surface, so that the contact area between the sound absorbing member main body and the pipe constituting the sound absorbing layer. And the vibration of the pipe surface is easily transmitted. At present, vibration from the pipe surface causes the soundproofing material itself to vibrate, and this vibration generates noise.

[0006] In recent years, the sound insulation effect of the outer walls of ordinary houses has been enhanced. As a result, sound from outside is considerably shielded, and background noise in the room is reduced. For this reason,
The sound generated in a house is particularly conspicuous, and there is a further demand for improved performance of soundproofing materials for piping. Also,
Since the soundproofing material attached to pipes, hoses, etc. is generally limited to a thickness of about 10 mm in the radial direction from the point of space, a sufficient soundproofing effect is achieved with a soundproofing material having a sound insulation layer and a sound absorption layer. Therefore, only some frequencies (relatively high frequencies) can be soundproofed. If the target frequency is restricted in this way, there is a problem in application to places where sound at the specific frequency, especially the entire audible range including the low range, is a problem due to differences in piping structure, engine specifications, rigidity, etc. May be.

SUMMARY OF THE INVENTION The present invention provides a space-saving, audible
An object to be solved is to provide a sound insulating material having a high sound insulating effect.

[0008]

In order to solve the above-mentioned problems, the inventors of the present invention have made various studies, and by using a sound absorbing member having both a sound absorbing portion of a cavity and a vibrating portion, it is possible to obtain a sound including low frequencies. Considering sound absorption in a high range, the present invention has been completed. That is, the soundproofing material of the present invention is mounted so as to cover the wall surface, and a sound absorbing member body made of a foamed resin having a hollow portion opened on the contact surface that is in contact with the wall surface,
A sheet-like sound absorbing member including an inner wall surface that defines the hollow portion and a skin layer provided integrally with the contact surface, and a sound insulating member provided on an outer surface of the sound absorbing member opposite to the skin layer Wherein the portion of the skin layer provided on the inner wall surface that defines the hollow portion has a separating means that is separated from other portions so as to be an independent vibrating membrane. Things.

[0009] In the soundproofing material of the present invention, the separating means comprises:
The groove may be a groove surrounding at least one of the bottom surface and the side surface of the cavity. Thereby, the rigidity of the skin layer in the groove portion increases, and the portion of the skin layer separated by the groove becomes an independent vibration film. As another separating means, the groove portion may be in the shape of a protrusion, and the same effect can be obtained by using a groove-shaped or protrusion-shaped separating means at an arbitrary position on the bottom surface or side surface of the cavity. be able to.

Further, in the above configuration, the vibration film can be easily formed by forming a film such as a film on the entire surface of the sound absorbing member main body which defines the cavity. In the soundproofing material of the present invention, the skin layer may be constituted by a film joined to the sound absorbing member main body. This film is effective when a cavity is formed on the cut surface of the foamed resin.

In the soundproofing material of the present invention, the skin layer may use a skin layer formed on the surface of the sound absorbing member main body when the sound absorbing member main body having a cavity formed by the cut surface of the foamed resin is formed. In the soundproofing material of the present invention, the thickness of the skin layer is preferably 100 μm or less. In the soundproofing material of the present invention,
The sound absorbing member is preferably an open-cell soft urethane foam.

[0012]

According to the soundproofing material of the present invention, the skin layer defining the cavity of the sound absorbing member main body becomes an independent vibration film. Due to the weight of the skin layer and the resilience of the sound absorbing member main body made of a foamed resin, a resonance phenomenon occurs at a specific frequency, particularly in a low frequency range. At the time of this resonance, the incident sound is converted into heat energy by the vibration of the skin layer,
Absorbs sound. Further, even if the thickness of the sound absorbing member body is limited and the volume of the hollow portion is reduced, the sound absorbing member body has a high-range sound absorbing effect. Therefore, the soundproofing material of the present invention is a soundproofing material that has a small space and absorbs sound over the entire audible range and has a high soundproofing effect.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The soundproofing material of the present invention is mounted on a wall such as a kitchen, a toilet, a bathroom or the like so as to cover a wall such as an outer peripheral surface of a pipe of a water supply facility. As a foamed resin to be a sound absorbing member, a foamed thermoplastic resin such as foamed polyethylene, foamed PVC, or urethane foam is used.
A flexible foam is preferred from the viewpoint of processability, and an open-cell polyurethane foam is particularly preferred from the viewpoint of sound absorption.

As the skin layer, a skin layer or a urethane film formed at the time of molding the foamed resin can be used. The foamed resin behind the independent skin layer adjusts the weight related to the resonance frequency and the spring constant in order to tune the resonance frequency of the independent skin layer to a frequency aimed at reduction. The weight of the independent skin layer can be adjusted by the thickness and the like, and the spring constant can be adjusted by the bubble ratio and the like.

It is preferable that the resonance frequency is set to a low frequency that does not have a sound absorbing effect mainly with the thickness of the sound absorbing member main body. The soundproofing material of the present invention may be formed in advance in the shape of the wall surface to be mounted, or may be in a sheet shape before mounting, and may be wound according to the shape of the wall surface during mounting.

[0016]

Next, the present invention will be described in detail with reference to drawings and graphs according to Embodiment 1.2. (Embodiment 1) As shown in FIGS. 1 and 2, the soundproofing material 1 of this embodiment is mounted on the outer peripheral surface of a cylindrical pipe 2 as a wall surface.
A sound absorbing member 3 that covers the outer peripheral surface of the pipe 2 in a cylindrical shape;
And a sound insulating member 4 provided on the outer surface of the first member.

The sound absorbing member 3 is, as shown in FIG.
A sound absorbing member body 3a made of an open-cell soft urethane foam having a cavity 5 opened to a contact surface 3s abutting on an outer peripheral surface of the member, and a sound absorbing member body 3a formed by the open-cell soft urethane foam When molding the sound absorbing member main body 3
and a skin layer 3b as a skin layer of the present invention formed on the surface of a.

In the present embodiment, a groove 6 surrounding the skin layer 3b on the bottom surface of the cavity 5 is formed. Cavity 5
Here, as shown in FIG. 3, the groove 6 is formed in a disc shape, and the groove 6 is formed in a circular shape substantially matching the diameter of the column of the cavity 5. Thereby, the skin layer portion in which the groove 6 is formed has higher rigidity than other portions, and the skin layer 3b of the circular portion surrounded by the groove 6 can be an independent vibration film 3c. .

The sound insulating member 4 is made of rubber, soft resin or the like having a high specific gravity. In the present embodiment, the soundproof material 1 having the above configuration is formed in a sheet shape as shown in FIG.
To be wound around. The sheet-shaped sound insulating material 1 can be manufactured as a two-layer integrally molded product of the sound insulating member 4 and the sound absorbing member 3. The cavity 5 is also formed at the time of molding. The groove 6 may be formed at the same time as the molding of the hollow portion 5 or may be formed by pressing after the molding.

According to the soundproofing material 1 of this embodiment, since the skin layer 3b formed on the bottom surface of the cavity 5 is surrounded by the groove 6, as shown in FIG.
Become nodes and become independent vibration films 3c. This vibrating membrane 3
As for c, the resonance phenomenon occurs at a specific frequency due to its own weight and the resiliency of the sound absorbing member main body portion 7 behind. At the time of this resonance, the vibrating membrane 3c vibrates, thereby converting incident sound into thermal energy and absorbing sound.

The resonance frequency f is determined by the following equation.

[0022]

[Formula 1] f = (1 / 2π) · (K / M) ^{1/2 In} Formula 1, K is a spring constant (unit system: ML ⁻¹ T ⁻² ) of the sound absorbing member main body portion 7 behind, and M Is the mass of the vibrating membrane 3c. Therefore, by reducing the density of the sound absorbing member main body 3a, K is reduced, and the resonance frequency, that is, the target frequency of soundproofing can be lowered. In addition, by reducing the thickness of the skin layer 3b, M becomes smaller, and the target frequency of soundproofing becomes higher.

The target frequency of soundproofing of only the sound absorbing member main body 3a is around 6 KHz. By providing the hollow portion 5 in the sound absorbing member main body 3a, the target frequency can be broadened to a lower frequency range. However, even with the cavity 5, 3 KHz
The target frequency drops only in the vicinity. However, by forming the vibrating film 3c on the bottom surface of the cavity and adjusting the resonance frequency of the vibrating film 3c with K and M as in the present embodiment, the soundproofing target frequency can be further extended to a lower frequency range.

FIG. 6 shows the sound absorption coefficient measured from 100 Hz to 6.3 KHz every 1/3 octave when the skin layer 3b is not provided on the sound absorbing member main body 3a and when the skin layer 3b (vibrating membrane 3c) is provided. is there. Sound absorbing member main body without skin layer 3b (Comparative Example 1) and sound absorbing member main body 3 provided with skin layer 3b
The density and thickness of a (the present invention) were the same. The thickness of the sound absorbing member main body 3a is 15 mm, and the thickness of the skin layer 3b is 30 μm.
m. The thickness of the sound insulating member 4 was 1.5 mm. Also,
As shown in FIG. 4, the cavity 5 was formed in a columnar shape with a flat bottom surface, and had a height of 7.5 mm and a diameter of 30 mm.

According to FIG. 6, when the skin layer 3b indicated by white dots is not present, the sound absorption coefficient characteristics are as follows. In the sound absorption coefficient characteristics when the skin layer 3b indicated by the dot is provided, the frequency of the sound absorption coefficient 0.5 is reduced to 1.25 to 1.6 KHz. FIG. 7 shows that the thickness of the sound absorbing member main body 3a is 10 mm.
It is a sound absorption coefficient characteristic of the same conditions in the case of. According to FIG. 7, when the skin layer 3b is not provided (Comparative Example 2), the frequency of the sound absorption coefficient 0.5 is about 3.15 KHz, whereas the skin layer 3b (vibrating membrane 3c) is not. The sound absorption coefficient characteristic of the case (present invention) is such that the frequency of sound absorption coefficient 0.5 is 1.6.
KHz. (Embodiment 2) As shown in FIG.
A cavity 8 having a V-shaped cross section was formed in the sound absorbing member main body 3a.
The other skin layer 3b is formed on the slope that defines the hollow portion 8.
A groove 6a was formed by pressing or the like along the top (bottom) of the V-shape so as to form a vibration film 3c 'independent of the above.

The sound-insulating material 11 having such a configuration (the present invention)
8 and the sound absorbing properties of the soundproofing material 3 of Comparative Example 3 were measured.
Shown in In the soundproof material 11, the thickness of the sound absorbing member main body 3a was 20 mm, and the thickness of the skin layer 3b was 30 μm. In the soundproofing material of Comparative Example 3, the thickness of the sound absorbing member main body 3a was 20 mm and there was no skin layer. In the soundproofing material of Comparative Example 3, while the frequency of the sound absorption coefficient of 0.5 is around 1.25 KHz,
In the soundproof material 11 of the present invention, the frequency of the sound absorption coefficient of 0.5 is reduced to almost 800 Hz.

As described above, in both the first and second embodiments, by forming the vibrating film on the inner wall surface that divides the cavity 5, the soundproofing target frequency can be broadened to a lower frequency range. It has been found that the effect is further improved by increasing the thickness of the sound absorbing member body. However, it was found that even when the sound absorbing member body having a thickness of 10 mm was used, the sound absorption coefficient characteristics spread to a lower frequency than when the vibration film having the same thickness was not provided, and a large soundproofing effect was achieved in a small space.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cross section in which a soundproofing material according to a first embodiment of the present invention is mounted on a cylindrical pipe.

FIG. 2 is an enlarged view of FIG. 1 taken along the line AA.

FIG. 3 is a perspective view showing the soundproofing material of Example 1 before being attached to a pipe.

FIG. 4 is a cross-sectional view of the soundproofing material of the first embodiment.

FIG. 5 is a cross-sectional view of the soundproofing material of the second embodiment.

FIG. 6 is a characteristic diagram of sound absorption coefficient as compared with the soundproofing material of Example 1 having no skin layer.

FIG. 7 is a characteristic diagram of the sound absorption coefficient as compared with the soundproofing material of Example 1 in which the thickness of the sound absorbing member is reduced and no skin layer is provided.

FIG. 8 is a characteristic diagram of sound absorption coefficient as compared with the soundproofing material of Example 2 having no skin layer.

[Explanation of symbols]

1, 11: soundproofing material, 2: pipe (wall surface), 3: sound absorbing member,
4 ... Sound insulation member, 5, 8 ... Cavity, 6 ... Groove (separation means).

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Noriomi Horie No. 4203, No. 4 Kita-gaiyama, Komaki-shi, Aichi F-term in Tokai Chemical Industry Co., Ltd. 3H025 CA01 CB05 CB39

Claims (6)

[Claims] A sound absorbing member main body made of a foamed resin, which is mounted so as to cover a wall surface and has a hollow portion opened on a contact surface abutting on the wall surface; an inner wall surface defining the hollow portion; A sheet-like sound absorbing member including a skin layer integrally provided on a contact surface, and a sound insulating member including a sound insulating member provided on an outer surface of the sound absorbing member on a side opposite to the skin layer, The soundproofing material according to claim 1, wherein a portion of the skin layer provided on the inner wall surface that defines the cavity has a separating unit that is separated from other portions so as to be an independent vibrating membrane. 2. The method according to claim 1, wherein the separating means includes a bottom surface of the cavity,
The soundproofing material according to claim 1, wherein the soundproofing material is a groove surrounding at least one of the side surfaces. 3. The soundproofing material according to claim 1, wherein the skin layer is made of a film bonded to the sound absorbing member. 4. The soundproofing material according to claim 1, wherein the skin layer is a skin layer formed at the time of molding the foamed resin. 5. The soundproofing material according to claim 1, wherein the thickness of the skin layer is 100 μm or less. 6. The soundproofing material according to claim 1, wherein the foamed resin is an open-cell soft urethane foam.