JP2007133246A - Sound absorbing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To absorb surrounding noise of an apartment house, an office, a theater and a movable body or the like. <P>SOLUTION: The sound absorbing structure of the invention comprises: a sheet-like low frequency sound absorbing material 2a which is laid on a floor 1 of the apartment house consisted of reinforced concrete; a plate-like reinforcement layer 3 laid on a surface of the low frequency sound absorbing material 2a in parallel with the low frequency sound absorbing material 2a; and a sheet 4 laid on a surface of the reinforcement layer 3, which has a characteristic for transmitting sound. The low frequency sound absorbing material 2a includes: a material which has an excellent sound absorbing characteristic in a low frequency region, for example: a film 21 composed of silicone rubber including inorganic compound which is laid at the reinforcement layer side; and a porous body layer 22 which is stacked in the lower face side of the film 21. The reinforcement layer 3 is constituted with a punching metal made of stainless steel whose aperture is about 40 to 70% and whose thickness is about 4 mm, and a sheet 4 is constituted with, for example, a carpet etc. made from fabric. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sound absorbing structure, and more particularly, to a sound absorbing structure capable of absorbing ambient noise such as an apartment house, an office, a theater, and a moving body.

  Conventionally, as this kind of sound absorbing material, (a) one using a porous body layer made of glass wool, rock wool or the like, (b) one formed by providing an air layer on the front side of the sound absorbing material, (c) ventilation A high-density and low-density fiber assembly having different degrees of 5 to 100 times is laminated (for example, see Patent Document 1).

  However, in the sound absorbing material (a), in order to effectively absorb noise in a low frequency region of 100 Hz or less, it is necessary to increase the thickness of the porous body layer. When the thickness is increased, there is a problem that the weight of the sound absorbing material is increased overall. Further, in the sound absorbing material (b), since an air layer is present on the front surface side of the sound absorbing material, there is a problem that the weight of the sound absorbing material becomes heavy and a large space must be taken.

  On the other hand, the sound-absorbing material (c) utilizes the viscous resistance of air, and by laminating fiber assemblies having different densities on a porous sound-absorbing structure that absorbs sound by converting sound wave energy into heat energy, The high-density part is an additional mass, and the low-density part plays the role of a spring, so that a so-called dynamic vibration absorber is constructed to improve the sound absorption coefficient particularly in the low frequency region. In particular, in a low frequency region of 100 Hz or less, there is a problem that a sufficient sound absorption effect cannot be obtained. In addition, sound and vibration in the low-frequency region generate not only air-borne sound but also shakiness of buildings and windows, so it is necessary to take measures against solid-borne sound and vibration prevention at the same time. The countermeasure was difficult.

  For this reason, the present applicant first uses the viscous resistance of air to convert the sound wave energy into heat energy and absorb the sound, and then stacks a fiber assembly having a different density on the porous sound absorbing structure. The second sound-absorbing material has been developed and applied (for example, see Patent Document 2).

  The sound absorbing material includes a foam layer disposed on the front surface side and a porous body layer laminated on the back surface side of the foam layer, and the foam layer is a first layer having a molecular weight of 500 to 5000. A diol, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a blowing agent, and a foam containing each component of isocyanate, and the porous body layer is formed of general-purpose glass wool. Yes.

  According to the sound absorbing material having such a configuration, a so-called dynamic vibration absorber, in which the high density portion plays the role of additional mass and the low density portion plays the role of spring, can improve the sound absorption coefficient particularly in the low frequency band. However, there were the following difficulties.

  1stly, the glass wool which comprises a porous body layer has the difficulty that a sound-absorbing effect becomes weak in the low frequency area | region of 100 Hz or less.

  Secondly, the foam layer and the porous body layer are integrally molded, and a surface film is formed on the front side of the foam layer during the integral molding, so that the degree of freedom of the product cannot be improved. there were. That is, since the surface film is simultaneously formed during the integral molding of the foam layer and the porous body layer, the front side of the foam layer or the back side of the porous body layer is necessary to exert the required sound absorption characteristics. There was the difficulty of having to change the side.

  Third, since the sound-absorbing material itself is not formed of a flame-retardant material, there is a difficulty in that it cannot satisfy the standards of the non-flammability test of the Building Standard Law.

  Fourthly, in apartment houses made of reinforced concrete, etc., a room that is located on the same floor as the first room and adjacent to the first room, from the room where the noise source exists (hereinafter referred to as the “first room”). In order to prevent noise to (hereinafter referred to as “second living room”), for example, it is necessary to install a sound absorbing material formed in a panel shape on the wall or ceiling of the first living room over the entire surface, Such a sound absorbing structure has a problem that it takes a long time to install the sound absorbing material and is expensive.

JP-A-8-152890 JP 2003-316364 A

  The present invention provides a sound-absorbing structure that can effectively absorb noise in low-frequency regions around apartment houses, offices, theaters, and moving objects, and can satisfy the standards of the non-combustibility test of the Building Standards Act. The purpose is that.

  The sound absorbing structure according to the first aspect of the present invention includes a sheet-like low-frequency sound absorbing material placed on the floor surface, and a plate-like shape disposed on the upper surface of the low-frequency sound absorbing material in parallel with the low-frequency sound absorbing material. A rubber comprising a reinforcing layer and a sheet having a property of transmitting sound placed on the upper surface of the reinforcing layer, and the low-frequency sound absorbing material includes an inorganic compound and / or carbon fiber disposed on the lower surface side of the reinforcing layer Alternatively, a film made of an acrylic resin and a porous body layer laminated on the lower surface side of the film are provided.

  The sound absorbing structure according to the second aspect of the present invention includes a sheet-like low-frequency sound absorbing material placed on the floor, and a plate-like shape arranged on the upper surface of the low-frequency sound absorbing material in parallel with the low-frequency sound absorbing material. A rubber comprising a reinforcing layer and a sheet having a property of transmitting sound placed on the upper surface of the reinforcing layer, and the low-frequency sound absorbing material includes an inorganic compound and / or carbon fiber disposed on the lower surface side of the reinforcing layer Alternatively, a film made of an acrylic resin and a porous body layer laminated on the lower surface side of the film and disposed in parallel with the floor surface through an air layer are provided.

  The sound absorbing structure according to the third aspect of the present invention includes a sheet-like low-frequency sound absorbing material placed on the floor, and a plate-like shape arranged on the upper surface of the low-frequency sound absorbing material in parallel with the low-frequency sound absorbing material. The low-frequency sound absorbing material includes a reinforcing layer and a sheet having a property of transmitting sound placed on the upper surface of the reinforcing layer, and the low-frequency sound absorbing material includes a porous body layer disposed on the lower surface side of the reinforcing layer, and a porous body layer A film made of rubber or acrylic resin containing an inorganic compound and / or carbon fiber laminated on the lower surface side of the film, and another porous body layer laminated on the lower surface side of the film.

  The sound absorbing structure according to the fourth aspect of the present invention includes a sheet-like low-frequency sound absorbing material placed on the floor surface, and a plate-like shape arranged on the upper surface of the low-frequency sound absorbing material in parallel with the low-frequency sound absorbing material. The low-frequency sound absorbing material includes a reinforcing layer and a sheet having a property of transmitting sound placed on the upper surface of the reinforcing layer, and the low-frequency sound absorbing material includes a porous body layer disposed on the lower surface side of the reinforcing layer, and a porous body layer A film made of a rubber or acrylic resin containing an inorganic compound and / or carbon fiber laminated on the lower surface side of the film, and another porous film laminated on the lower surface side of the film and parallel to the floor surface through an air layer And a body layer.

  The sound absorbing structure according to the fifth aspect of the present invention includes a sheet-like low-frequency sound absorbing material placed on the floor, and a plate-like shape arranged on the upper surface of the low-frequency sound absorbing material in parallel with the low-frequency sound absorbing material. A rubber including a reinforcing layer and a sheet having a property of transmitting sound placed on the upper surface of the reinforcing layer, and the low-frequency sound absorbing material includes a mechanical compound and / or carbon fiber disposed on the lower surface side of the reinforcing layer Or the film | membrane which consists of an acrylic resin is provided, and a film | membrane is arrange | positioned in parallel with a floor surface through an air layer.

  According to a sixth aspect of the present invention, in the sound absorbing structure according to any one of the first to fifth aspects, the reinforcing layer protects the low frequency sound absorbing material and has a property of transmitting sound. It consists of a body.

  According to a seventh aspect of the present invention, in the sound absorbing structure according to any one of the first to fifth aspects, the reinforcing layer is made of a metal plate-like body having a large number of openings.

  According to an eighth aspect of the present invention, in the sound absorbing structure according to any one of the first to fifth aspects, the reinforcing layer is made of a punching metal or an expanded metal.

  According to a ninth aspect of the present invention, in the sound absorbing structure according to the seventh aspect, the aperture ratio of the plate-like body is 40 to 70%.

  According to a tenth aspect of the present invention, in the sound absorbing structure according to any one of the first to ninth aspects, the rubber is silicone rubber, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, nitrile butadiene. It is made of any rubber selected from rubber, butyl rubber, ethylene propylene rubber, fluorine rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, polysulfide rubber, and polyolefin.

  According to an eleventh aspect of the present invention, in the sound absorbing structure according to any one of the first to tenth aspects, the inorganic compound is any one of Si, Ca, Sr, Ba, Al, and Mg. Or a mixture of compounds containing any one of Si, Ca, Sr, Ba, Al, and Mg.

  According to a twelfth aspect of the present invention, in the sound absorbing structure according to any one of the first to eleventh aspects, the carbon fiber has a fiber diameter of 10 to 30 μm and an average length of 0.3 to 0.3. 2 mm, and the added amount is 0.5 to 10 parts with respect to the main acrylic resin.

According to a thirteenth aspect of the present invention, in the sound absorbing structure according to any one of the first to twelfth aspects, the combustion heat generation amount of the film is 8 MJ / m ² or less.

A fourteenth aspect of the present invention is the sound absorbing structure according to any one of the first to thirteenth aspects, wherein the film has a combustion heat generation rate of [200 kW / m ² ] · 10 sec or less. It is.

  According to a fifteenth aspect of the present invention, in the sound absorbing structure according to any one of the first to fourteenth aspects, at least one of the porous body layer and the other porous body layer is flame retardant. It is formed with the material which has.

  According to a sixteenth aspect of the present invention, in the sound absorbing structure according to any one of the first to fifteenth aspects, at least one of the porous body layer and the other porous body layer is made of glass wool or rock. Any one of wool or a mixture thereof.

  According to a seventeenth aspect of the present invention, in the sound absorbing structure according to any one of the first to sixteenth aspects, the film is integrated with at least one of the porous body layer and the other porous body layer. It has become.

  According to an eighteenth aspect of the present invention, in the sound absorbing structure according to any one of the first to sixteenth aspects, the film is bonded to at least one of a porous body layer and another porous body layer. And are integrated.

  According to a nineteenth aspect of the present invention, in the sound absorbing structure according to any one of the first to sixteenth aspects, the film is at least one of a porous body layer and another porous body layer by heat fusion. It is integrated with either.

  According to a twentieth aspect of the present invention, in the sound absorbing structure according to any one of the first to sixteenth aspects, the film is formed of at least one of a porous body layer and another porous body layer by a silicone graft reaction. It is integrated with either.

  According to a twenty-first aspect of the present invention, in the sound absorbing structure according to any one of the first to sixteenth aspects, the film is at least part of the porous body layer and the other porous body layer. It is integrated with at least one of the porous body layer and the other porous body layer by entering any one of the holes.

  According to the sound absorbing structure of the first aspect to the twenty-first aspect of the present invention, the following effects are obtained.

  First, by arranging a low-frequency sound absorbing material on the floor of a room (first room) where a noise source in a low frequency region of about 200 Hz or less exists, noise in the first room can be effectively reduced. Can be absorbed. Therefore, according to the sound absorbing structure of the present invention, unlike the conventional case, the second room (the first room) from the first room can be provided without providing the low-frequency sound absorbing material on the wall or ceiling of the first room. The noise to the room on the same floor as the first room and adjacent to the first room can be effectively prevented.

  Second, by changing the specifications of the low-frequency sound absorbing material arranged on the floor surface, sound absorption according to the frequency characteristics of the noise source can be performed.

  Thirdly, when the porous body layer constituting the low-frequency sound absorbing material is formed of glass wool, the glass wool has a function as a heat insulating material, and thus has high added value as a highly heat-insulating and sound-insulating house. A house can be provided.

  Fourthly, by arranging a low-frequency sound absorbing material on the floor surface of a moving body such as an elevator or an automobile, noise around the moving body can be absorbed, especially in a moving body such as an automobile aiming at weight reduction. Is a film-like sound absorbing structure with an air layer to effectively absorb noise around the moving body (echo inside the elevator, noise inside the car, etc.) while suppressing the weight of the moving body itself. Can do.

  Fifth, the sound absorbing material itself is provided with flame retardancy that complies with the flame retardance standard in the Building Standards Act, so that it can be applied to places where flame retardancy is required.

  Sixth, since no halogen-based flame retardant or lead-based compound is used as a flame retardant, there is no possibility of generating toxic gas during combustion, and a sound absorbing structure with environmental protection measures can be provided.

  Seventh, since the reinforcing material or rigid wall layer is provided on the upper surface side of the low-frequency sound absorbing material, even if it is applied to the floor surface of an apartment house, office, theater, etc., the low-frequency sound absorbing material is prevented from being damaged. can do.

  Eighth, the degree of freedom of the product form can be improved by using a low-frequency sound absorbing material in which the membrane is integrated with the porous body layer and / or another porous body layer.

Hereinafter, a preferred embodiment to which the sound absorbing structure of the present invention is applied will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a cross-sectional view showing an embodiment in which the sound absorbing structure of the present invention is applied to a floor surface of an apartment house made of reinforced concrete.

  In the same figure, the sound absorbing structure in the present invention includes a sheet-like low frequency sound absorbing material 2a placed on the floor surface 1 of an apartment house made of reinforced concrete, and a low frequency sound absorbing material 2a on the upper surface of the low frequency sound absorbing material 2a. A plate-shaped reinforcing layer 3 arranged in parallel and a sheet 4 placed on the upper surface of the reinforcing layer 3 and having a property of transmitting sound are provided.

  The reinforcing layer 3 is formed of a plate-like body that mechanically protects a low-frequency sound absorbing material 2a described later and has a property of transmitting sound. Specifically, it is made of a metal plate having a large number of openings, for example, a punching metal or an expanded metal made of stainless steel having an opening ratio of about 40 to 70% and a thickness of about 4 mm. Here, the reason why the aperture ratio of the plate-like body is set to 40 to 70% is that sound is not sufficiently transmitted when the aperture ratio is less than 40%, and when the aperture ratio exceeds 70%, the entire plate-like body is formed. This is because the mechanical strength becomes weak and the protection of the low-frequency sound absorbing material 2a becomes insufficient.

  The sheet 4 has, for example, good heat retention, high elasticity, and flame retardancy, specifically, a fabric carpet or the like.

  As the low frequency sound absorbing material 2a, a material exhibiting excellent sound absorbing characteristics in a low frequency range of 100 Hz to 200 Hz, specifically, a sound absorbing material developed and filed by the present inventors is suitable.

  Specifically, as disclosed in Japanese Patent Application No. 2005-77593, the low-frequency sound absorbing material includes a film 21 made of silicone rubber containing an inorganic compound and disposed on the lower surface side of the reinforcing layer 3. And a porous body layer 22 laminated on the lower surface side.

  The film | membrane 21 is formed with the material which has a flame retardance and does not generate | occur | produce noxious gas at the time of combustion. Specifically, the film 21 is a compound containing any one of Si, Ca, Sr, Ba, Al, Mg or Si, Ca, Sr, Ba in a ratio of 2: 1 to 1: 1 with silicone rubber. , Al and Mg are mixed with an inorganic compound composed of a mixture of compounds containing any one of them.

  In the membrane 21 having such a structure, a high bulk density and a small particle diameter of barium sulfate or the like are mixed into the porous chamber portion of the silicone rubber having a network structure, so that it is nonflammable and flexible, and has a predetermined value. A film having an areal density can be formed.

  FIG. 2 is an explanatory diagram showing the sound absorption coefficient, surface density, film thickness, heat generation amount, and heat generation rate of the film 21 according to the embodiment of the present invention together with a comparative example.

  Here, the film 21 in this example is formed by mixing silica, calcium carbonate, strontium carbonate, and barium sulfate in a ratio of 2: 1 to silicone rubber, and a film made of urethane is used as a comparative example. ing.

  The calorific value was measured by the method specified in Article 2, Item 9 of the Building Standard Law, and the heat generation rate was measured by the method specified by ISO5660.

From the figure, the film 21 in the present embodiment can obtain the same sound absorption coefficient and surface density as those in the comparative example even if the film thickness is about 1/3 that of the comparative example. Moreover, it can adapt to the nonflammable grade prescribed | regulated to Building Standard Act Article 2 No. 9, and also can make a combustion heat_generation | fever rate less than [200kW / m < ² * 10sec].

  Next, various performances required for the film 21 having such a configuration will be described.

First, it is preferable to use a membrane 21 having a combustion heat generation amount per unit volume of 8 MJ / m ² or less. This is because if the calorific value per unit volume of the membrane 21 exceeds 8 MJ / m ² , it cannot conform to the non-combustible grade defined in the Building Standard Act Article 2 No. 9 which is the applicable regulation of the product according to this embodiment. . Note that the amount of combustion heat generated by the film 21 can be adjusted by the type and amount of the inorganic filler to be blended with the raw material resin for the film 21.

According to the film 21 made of silicone rubber containing such an inorganic compound, in a test piece having a width of 100 mm, a length of 100 mm, and a thickness of 3 to 50 mm, a combustion heat generation per unit volume in a combustion heat generation test specified by ISO 5660 The amount can be 8 MJ / m ² or less.

Second, it is preferable to use a film 21 having a combustion heat generation rate of [200 kW / m ² ] · 10 sec or less. This is because if the combustion heat generation rate of the membrane 21 exceeds [200 kW / m ² ] · 10 sec ³ , it does not conform to the non-combustible grade specified in Article 2, Item 9 of the Building Standard Law.

According to the membrane 21 made of silicone rubber containing such an inorganic compound, in a test piece having a width of 100 mm, a length of 100 mm, and a thickness of 3 to 50 mm, the combustion heat generation rate is set to [200 kW] in the combustion heat generation rate test specified by ISO5660. / M ² ] • Can be 10 sec or less.

  Next, the porous body layer 22 is formed of a material having flame retardancy. Specifically, it is made of glass wool, rock wool or a mixture thereof. Here, the porous body layer 22 is formed with a thickness of 1 to 50 mm, preferably 10 to 25 mm.

  The porous body layer 22 having such a configuration has excellent sound absorption characteristics over a wide range from a low frequency region to a high frequency region, and has an effective damping property for reducing solid-borne sound and vibration. Demonstrate.

  In this embodiment, the porous body layer 22 is laminated on the lower surface side of the membrane 21 because the portion of the membrane 21 acts as an additional mass, that is, the role of a weight, and the portion of the porous body layer 22 is a spring, that is, air. This is because it acts as a spring and absorbs sound due to membrane vibration.

  The membrane 21 is preferably integrated with the porous body layer 22 by adhesion, a silicone graft reaction, or the like in order to improve the degree of freedom of the product form and simplify the construction on site.

  FIG. 3 shows the sound absorption characteristics of the low-frequency sound absorbing material in the first embodiment. Here, in the figure, the broken line L1 indicates the sound absorption characteristics of a conventional sound absorbing material in which the thickness of the porous body layer (glass wool) is 100 mm, and the solid line L2 indicates the thickness of the film (silicone rubber film) 21 by 0.5 mm. The sound absorption characteristics of the low frequency sound absorbing material 2a in the first embodiment in which the thickness of the porous body layer (glass wool) 22 is 75 mm are shown.

  From the figure, the conventional sound absorbing material has a high sound absorption rate in a high frequency region exceeding about 200 Hz, but has a low sound absorption rate in a low frequency region of about 200 Hz or less, whereas the sound absorbing material in the first embodiment is low. It can be seen that although the sound absorption coefficient is low in the high frequency region of 200 Hz or higher, the sound absorption coefficient is high in the low frequency region of 200 Hz or less. Therefore, if the low-frequency sound absorbing material 2a in the first embodiment is used, a sound absorbing material that can cope with the low-frequency region can be provided.

  Next, a method for installing the low-frequency sound absorbing material 2a configured as described above on the floor surface 1 of the apartment house made of reinforced concrete will be described.

  1 and 4, first, a plurality of metal liners 5a, 5b, 5c,..., For example, a prismatic column having a width of 40 mm and a height of 80 mm are formed on the floor surface 1 of a reinforced concrete apartment building. For example, stainless steel liners are laid in parallel at intervals of 910 mm. Thereby, a storage groove for laying the low-frequency sound absorbing material 2a on the floor surface 1 is formed. Here, the height of each of the liners 5a, 5b, 5c,... (Depth of the storage groove) is designed to be approximately the same as or slightly higher than the thickness of the low frequency sound absorbing material 2a. ing.

  Next, a large number (for example, 30) of panel-shaped low-frequency sound absorbing materials 2a (for example, vertical width: 607 mm, horizontal width: 910 mm, thickness) are formed in each of the storage grooves formed in this manner. 75 mm) with the porous body layer 22 facing the floor surface 1 side.

  Next, a reinforcing plate 3 made of stainless steel punching metal having a thickness of about 2 mm and an aperture ratio of about 40% is provided between the tops (upper parts in FIG. 1) of the liners 5a, 5b, 5c,. A sheet 4 made of carpet is placed on the upper surface of the reinforcing plate 3 so as to cover the upper surface of the frequency sound absorbing material 2a. Thus, each low-frequency sound absorbing material 2a is mechanically protected by the storage groove and the reinforcing plate 3 partitioned by the liners 5a, 5b, 5c,.

FIG. 5 shows a comparison of power levels depending on whether or not a sound absorbing structure is applied to the floor surface. Here, the comparative example shows the power level of a so-called ordinary apartment house in which the sound absorbing structure is not applied to the floor surface 1, and the embodiment is made from a silicone rubber having a thickness of 0.5 mm on the floor surface 1. According to the first embodiment, a low-frequency sound-absorbing material 2a in which a porous body layer 22 made of 32K felt glass wool (32 kg / m ³ hard glass wool) having a thickness of 75 mm is laminated is disposed on the formed film 21. The power level of the sound absorbing structure is shown. The noise level was measured according to JIS A 1409: 1998 “Method for measuring sound absorption coefficient of reverberation room method”.

  From the figure, the sound absorbing structure in the present embodiment has a dominant difference of about 30 dB in the sound absorbing characteristics of 200 Hz, which is the dominant noise in the living room, compared to the comparative example, and the sound absorbing structure in the present invention is different from the first living room. It can be seen that this is very effective as a noise prevention measure for the second room.

As described above, according to the sound-absorbing structure of the present invention, even if a low-frequency sound-absorbing material is not provided on the wall or ceiling of the first living room as in the prior art, the sound absorption structure of the first living room is about 200 Hz or less. Noise in the low frequency region can be effectively absorbed, and as a result, noise from the first room to the second room can be effectively prevented.
[Second Embodiment]
FIG. 6 is a sectional view showing a second embodiment of the sound absorbing structure in the present invention. In the figure, parts common to those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  In this embodiment, as shown in FIG. 6, a porous body layer (hereinafter referred to as “first porous body layer”) 22 on the upper surface side of the film 21 instead of the low frequency sound absorbing material 2a shown in FIG. Is a low frequency sound absorbing material 2b in which another porous body layer (hereinafter referred to as "second porous body layer") 23 is laminated on the lower surface side.

  Here, the first and second porous body layers 22 and 23 are laminated on the resin film 21 because the film 21 portion acts as an additional mass, that is, a role of a weight, and the first and second porous bodies. This is because the layers 22 and 23 function as a spring, that is, an air spring, and perform sound absorption by membrane vibration.

  The second porous body layer 23 is formed of the same material as the porous body layer 22 shown in FIG. The resin film 21 is preferably integrated with at least one of the first and second porous body layers 22 and 23 by the same means as described above.

  FIG. 7 shows the sound absorption characteristics of the low frequency sound absorbing material 2b in the second embodiment. Here, in the figure, the broken line L1 is the sound absorption characteristic of the conventional sound absorbing material in which the thickness of the porous body layer (glass wool) is 100 mm, and the solid line L3 is the film (silicon rubber film), as shown in FIG. ) The sound absorption characteristics of the sound absorbing material in the second embodiment in which the thickness of 21 is 0.5 mm and the thickness of the first and second porous body layers (glass wool) 22 and 23 is 75 mm.

  As shown in the figure, the conventional sound absorbing material has a high sound absorption rate in the high frequency region exceeding about 200 Hz, as described above, but has a low sound absorption rate in the low frequency region below about 200 Hz. It can be seen that the low-frequency sound-absorbing material in this form exhibits excellent sound-absorbing characteristics not only in a low-frequency region of about 200 Hz or less but also in a high-frequency region of about 200 Hz or more.

  FIG. 8 shows a comparison of power levels depending on whether or not a sound absorbing structure is applied to the floor surface. Here, the comparative example shows the power level of a so-called ordinary apartment house in which the sound absorbing structure is not applied to the floor surface 1, and the embodiment is made from a silicone rubber having a thickness of 0.5 mm on the floor surface 1. A first porous body layer 22 made of 32K felt glass wool having a thickness of 25 mm is formed on the upper surface side of the formed film 21, and a second porous body layer 23 made of 32 K felt glass wool having a thickness of 50 mm is formed on the lower surface side. The power level of the sound absorption structure which concerns on 2nd Embodiment which has arrange | positioned the low frequency sound-absorbing material 2b which laminated | stacked is shown. The noise level was measured in accordance with JIS A 1409: 1998 “Method of measuring reverberation room method sound absorption coefficient” in the same manner as in the above-described embodiment.

  From the same figure, also in the sound absorbing structure in the present embodiment, a dominant difference of about 30 dB is recognized in the sound absorbing characteristics at 200 Hz, which is the dominant noise in the room, as in the previous embodiment, and the sound absorbing structure in the present invention is the first. It can be seen that this is very effective as a noise prevention measure from the second room to the second room.

As described above, also in the sound absorbing structure of the present invention, the low frequency of about 200 Hz or less in the first living room is not required even if the low-frequency sound absorbing material is not provided on the wall or ceiling of the first living room as in the past. It is possible to effectively absorb the noise in the frequency domain, and thus effectively prevent noise from the first room to the second room.
[Third Embodiment]
FIG. 9 is a cross-sectional view showing a third embodiment of the sound absorbing structure in the present invention. In the figure, parts common to those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  9, in this embodiment, a low-frequency sound absorbing material 2c having a film-like sound absorbing structure is used instead of the low-frequency sound absorbing material 2a shown in FIG.

  That is, the low-frequency sound absorbing material 2 c in this embodiment includes a film 21 made of silicone rubber containing an inorganic compound disposed on the lower surface side of the reinforcing layer 3, and the film 21 is a floor through the air layer 6. It is arranged parallel to the surface 1.

  In the film-like sound absorbing structure having such a configuration, the air layer 6 acts as a spring with respect to the mass of the film 21 as the low-frequency sound absorbing material, forming a single resonance system, as described above. When the frequency matches the resonance frequency of this single resonance system, the membrane 21 vibrates and is absorbed by internal friction.

Also in this embodiment, by arranging the film 21 as the low frequency sound absorbing material 2c on the floor surface of the room of the reinforced concrete apartment house, the noise in the low frequency region of about 200 Hz or less in the room is effectively absorbed. As a result, noise from the first living room to the second living room can be effectively reduced without providing a low-frequency sound absorbing material on the wall or ceiling of the first living room as in the prior art. Can be prevented. Further, in this embodiment, since it is a film-like sound absorbing structure having an air layer, when applied to a moving body such as an automobile aiming at weight reduction, the moving body suppresses an increase in the weight of the moving body itself. Can effectively absorb the ambient noise.
[Fourth Embodiment]
FIG. 10 is a sectional view showing a fourth embodiment of a sound absorbing structure in the present invention. In the figure, parts common to those in FIGS. 1 and 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  10, in this embodiment, a thin low-frequency sound absorbing material 2a 'is used instead of the low-frequency sound absorbing material 2a shown in FIG.

  That is, the low-frequency sound absorbing material 2a ′ in this embodiment is formed by laminating a thin porous body layer 22 ′ having a thickness smaller than that of the porous body layer 22 shown in FIG. The thin porous body layer 22 ′ is arranged in parallel with the floor surface 1 through the air layer 6.

In this embodiment, the sound absorption characteristics are slightly reduced by the amount of the porous body layer formed thinner than in the first embodiment, but the so-called back surface is formed between the floor surface 1 and the porous body layer 22 '. The presence of the air layer can reduce the weight and cost of the sound absorbing structure as a whole. Therefore, when this embodiment is applied to a moving body such as an automobile aiming at weight reduction, it is possible to effectively absorb noise around the moving body while suppressing an increase in the weight of the moving body itself.
[Fifth Embodiment]
FIG. 11 is a sectional view showing a fifth embodiment of a sound absorbing structure in the present invention. In the figure, parts common to those in FIGS. 6 and 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  11, in this embodiment, a thin low frequency sound absorbing material 2b 'is used instead of the low frequency sound absorbing material 2b shown in FIG.

  That is, the low-frequency sound-absorbing material 2b ′ in this embodiment has a second thin porous body layer 23 formed thinner on the lower surface side of the film 21 than the second porous body layer 23 shown in FIG. ′ Is laminated, and the thin second porous body layer 23 ′ is arranged in parallel with the floor surface 1 through the air layer 6.

Also in this example, although the sound absorption characteristics are slightly lowered by the amount of the second porous body layer formed thinner than the second example, the floor surface 1 and the second porous body layer are reduced. By providing a so-called back air layer between 23 ', it is possible to reduce the weight and cost of the sound absorbing structure as a whole. Therefore, also in this embodiment, when applied to a moving body such as an automobile aiming at weight reduction, noise around the moving body can be effectively absorbed while suppressing an increase in the weight of the moving body itself.
[Sixth Embodiment]
In the above-described embodiment, the case where the film 21 is formed of silicone rubber containing an inorganic compound is described. However, the film 21 is made of acrylic resin at a ratio of 2: 1 to 1: 1, and Si, Ca, Sr, A compound containing any one of Ba, Al and Mg or an inorganic compound composed of a mixture of compounds containing any one of Si, Ca, Sr, Ba, Al and Mg, and the following carbon fiber mixed therein May be formed.

  In the film 21 having such a configuration, by adding carbon fiber to the acrylic resin, it is possible to form a resin film having a predetermined surface density in addition to being nonflammable and flexible.

  Here, it is preferable to use carbon fibers having a fiber diameter of 10 to 30 μm, an average length of 0.3 to 2 mm, and an addition amount of 0.5 to 10 parts relative to the main acrylic resin. Here, the fiber diameter is set to 10 to 30 μm because the bond between the resins is lowered when the fiber diameter is less than 10 μm, and the flexibility of the resin is lowered when the fiber diameter exceeds 30 μm. The average length is set to 0.3 to 2 mm because the bond between the resins decreases when the average length is less than 0.3 mm, and the average length exceeds 2 mm. This is because the flexibility of the resin is lowered. Furthermore, the reason why the addition amount is set to 0.5 to 10 parts with respect to the main acrylic resin is that when the addition amount is less than 0.5 parts with respect to the main acrylic resin, the bond between the resins decreases. This is because when the amount exceeds 10 parts with respect to the main acrylic resin, the flexibility of the resin decreases.

  FIG. 12 is an explanatory diagram showing the sound absorption coefficient, surface density, film thickness, heat generation amount, and heat generation rate of the resin film according to the sixth embodiment together with a comparative example.

  Here, the film 21 in the sixth embodiment is formed by mixing acrylic resin with silica, calcium carbonate, strontium carbonate, barium sulfate, aluminum hydroxide, magnesium hydroxide in a ratio of 2: 1, As a comparative example, a resin film made of urethane is used.

  The calorific value was measured by the method specified in Article 2, Item 9 of the Building Standard Law, and the heat generation rate was measured by the method specified by ISO5660.

From the figure, the film 21 in the sixth embodiment can obtain the sound absorption coefficient and surface density equivalent to those of the comparative example even if the film thickness is made about 1/3 that of the comparative example. . Moreover, it can adapt to the nonflammable grade prescribed | regulated to Building Standard Law Article 2 No. 9, and also can make a combustion heat_generation | fever rate less than [200kW / m < ² >] * 10sec.

  In the above-described embodiments, the present invention is described with specific embodiments shown in the drawings. However, the present invention is not limited to these embodiments, and as long as the effects of the present invention are exhibited, You may comprise as follows.

  1stly, in the above-mentioned Example, although the case where it applied to the floor surface 1 of the apartment house which consists of reinforced concrete which has the performance as a rigid wall is described, the floor surface 1 does not have the performance as a rigid wall Therefore, it is necessary to lay a back rigid wall layer (for example, a steel plate having a thickness of about 2 mm or an aluminum plate having a thickness of about 5 mm) on the back side of the low-frequency sound absorbing material, that is, on the floor surface 1.

  Secondly, in the above-described embodiment, the case where silicone rubber is used as the film is described. However, instead of silicone rubber, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, nitrile butadiene rubber, butyl rubber are used. Any rubber selected from ethylene propylene rubber, fluorine rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, polysulfide rubber, and polyolefin may be used.

  Thirdly, in the above-described embodiments, the case where the membrane is integrated with the porous body layer (or other porous body layer) by means such as adhesion or silicone graft reaction is described. When the porous body layer (or other porous body layer) is heated to a temperature at which the membrane and / or porous body layer (or other porous body layer) softens (eg, 80 ° C.), Both may be integrated by applying some pressure.

Fourthly, in the above-described embodiment, the combustion heat generation amount and the combustion heat generation rate of the film are described. However, the combustion heat generation amount of the low-frequency sound absorbing material itself is 8 MJ / m ² or less, and the combustion heat generation rate is [200 kW / m 2]. ² ] · 10 sec or less.

  Fifth, in the above-described embodiment, the case where the present invention is applied to the floor surface of an apartment house made of reinforced concrete is described. However, the free access floor of an office, the floor of a theater, the floor of an elevator, the floor of an automobile ( Even when applied to a floor pan), ambient noise can be effectively absorbed.

Sectional drawing of the sound absorption structure in the 1st Embodiment of this invention. Explanatory drawing which shows the mixing ratio of the silicone rubber and filler in the 1st Embodiment of this invention. Explanatory drawing which shows the sound absorption characteristic of the low frequency sound absorption material in the 1st Embodiment of this invention. Explanatory drawing which shows the installation condition of the low frequency sound-absorbing material in the 1st Embodiment of this invention. Explanatory drawing which shows the relationship between the power level and frequency of a sound absorption structure in the 1st Embodiment of this invention. Sectional drawing of the sound absorption structure in the 2nd Embodiment of this invention. Explanatory drawing which shows the sound absorption characteristic of the low frequency sound-absorbing material in the 2nd Embodiment of this invention. Explanatory drawing which shows the measurement condition of the power level of the sound absorption structure in the 2nd Embodiment of this invention. Sectional drawing of the sound absorption structure in the 3rd Embodiment of this invention. Sectional drawing of the sound absorption structure in the 4th Embodiment of this invention. Sectional drawing of the sound absorption structure in the 5th Embodiment of this invention. Explanatory drawing which shows the mixing ratio of the acrylic resin and filler in other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Floor surface 2a, 2b, 2c, 2d, 2e, 2f ... Low frequency sound-absorbing material 21 ... Membrane 22 ... 1st porous body layer (porous body layer)
23 ... 2nd porous body layer (other porous body layers)
3 ... Reinforcing layer 4 ... Sheets 5a, 5b, 5c ... Liner 6 ... Air layer

Claims (21)

A sheet-like low-frequency sound-absorbing material placed on the floor, a plate-like reinforcing layer arranged in parallel with the low-frequency sound-absorbing material on the upper surface of the low-frequency sound-absorbing material, and an upper surface of the reinforcing layer And a sheet having a property of transmitting the placed sound,
The low-frequency sound absorbing material includes a film made of rubber or acrylic resin containing an inorganic compound and / or carbon fiber disposed on the lower surface side of the reinforcing layer, and a porous body layer laminated on the lower surface side of the film. A sound absorbing structure characterized by comprising. A sheet-like low-frequency sound-absorbing material placed on the floor, a plate-like reinforcing layer arranged in parallel with the low-frequency sound-absorbing material on the upper surface of the low-frequency sound-absorbing material, and an upper surface of the reinforcing layer And a sheet having a property of transmitting the placed sound,
The low-frequency sound-absorbing material is laminated on the lower surface side of the membrane and a film made of rubber or acrylic resin containing an inorganic compound and / or carbon fiber, which is disposed on the lower surface side of the reinforcing layer. A sound absorbing structure comprising: a porous body layer disposed in parallel with the floor surface. A sheet-like low-frequency sound-absorbing material placed on the floor, a plate-like reinforcing layer arranged in parallel with the low-frequency sound-absorbing material on the upper surface of the low-frequency sound-absorbing material, and an upper surface of the reinforcing layer And a sheet having a property of transmitting the placed sound,
The low-frequency sound absorbing material is made of a porous body layer disposed on the lower surface side of the reinforcing layer and a rubber or acrylic resin containing an inorganic compound and / or carbon fiber laminated on the lower surface side of the porous body layer. A sound absorbing structure comprising: a film; and another porous body layer laminated on a lower surface side of the film. A sheet-like low-frequency sound-absorbing material placed on the floor, a plate-like reinforcing layer arranged in parallel with the low-frequency sound-absorbing material on the upper surface of the low-frequency sound-absorbing material, and an upper surface of the reinforcing layer And a sheet having a property of transmitting the placed sound,
The low-frequency sound absorbing material is made of a porous body layer disposed on the lower surface side of the reinforcing layer and a rubber or acrylic resin containing an inorganic compound and / or carbon fiber laminated on the lower surface side of the porous body layer. A sound absorbing structure comprising: a membrane; and another porous body layer laminated on the lower surface side of the membrane and disposed in parallel with the floor surface through an air layer. A sheet-like low-frequency sound-absorbing material placed on the floor, a plate-like reinforcing layer arranged in parallel with the low-frequency sound-absorbing material on the upper surface of the low-frequency sound-absorbing material, and an upper surface of the reinforcing layer And a sheet having a property of transmitting the placed sound,
The low-frequency sound absorbing material includes a film made of rubber or acrylic resin containing a mechanical compound and / or carbon fiber disposed on the lower surface side of the reinforcing layer,
The sound absorbing structure, wherein the film is arranged in parallel with the floor surface through an air layer.   6. The sound absorbing structure according to claim 1, wherein the reinforcing layer is made of a plate-like body having a property of protecting the low frequency sound absorbing material and transmitting sound.   6. The sound absorbing structure according to claim 1, wherein the reinforcing layer is made of a metal plate having a large number of openings.   The sound absorbing structure according to claim 1, wherein the reinforcing layer is made of a punching metal or an expanded metal.   The sound absorbing structure according to claim 7, wherein an aperture ratio of the plate-like body is 40 to 70%.   The rubber includes silicone rubber, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber, fluoro rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, The sound absorbing structure according to any one of claims 1 to 9, wherein the sound absorbing structure is any rubber selected from sulfurized rubber and polyolefin.   The inorganic compound is composed of a compound containing any one of Si, Ca, Sr, Ba, Al, and Mg or a mixture of compounds containing any one of the Si, Ca, Sr, Ba, Al, and Mg. The sound absorbing structure according to claim 1, wherein:   The carbon fiber has a fiber diameter of 10 to 30 µm, an average length of 0.3 to 2 mm, and an addition amount of 0.5 to 10 parts with respect to the main acrylic resin. The sound absorbing structure according to claim 11. The sound absorption structure according to any one of claims 1 to 12, wherein a combustion heat generation amount of the film is 8 MJ / m ² or less. 14. The sound absorbing structure according to claim 1, wherein a combustion heat generation rate of the film is [200 kW / m ² ] · 10 sec or less.   The sound absorbing structure according to any one of claims 1 to 14, wherein at least one of the porous body layer and the other porous body layer is formed of a flame retardant material. .   16. At least one of the porous body layer and the other porous body layer is made of glass wool, rock wool, or a mixture thereof. Sound absorption structure.   The sound absorbing structure according to any one of claims 1 to 16, wherein the film is integrated with at least one of the porous body layer and the other porous body layer.   The sound absorbing structure according to any one of claims 1 to 16, wherein the film is integrated with at least one of the porous body layer and the other porous body layer by adhesion.   The sound absorption according to any one of claims 1 to 16, wherein the film is integrated with at least one of the porous body layer and the other porous body layer by heat fusion. Construction.   The sound absorption according to any one of claims 1 to 16, wherein the film is integrated with at least one of the porous body layer and the other porous body layer by a silicone graft reaction. Construction. The membrane includes at least one of the porous body layer and the other porous body layer by allowing a part of the membrane to enter at least one of the pores of the porous body layer and the other porous body layer. The sound-absorbing structure according to any one of claims 1 to 16, wherein the sound-absorbing structure is integrated with either one.

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