JPH108845A - Soundproof door - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a sound insulating function by applying the constitution that a porous elastic material having specified bulk density and Young's modulus is stacked on the inner surface of at least one of surface plates faced to each other, and a mass membrane having the specified surface density is stacked on the inner surface of the elastic material. SOLUTION: A porous elastic material 3 made, for example, of rock wool having bulk density equal to or less than 100kg/cm<3> and a Young's modulus between 1.0×10<3> and 1.0×10<6> N/m<2> is stacked on the inner surface of at least one of surface plates 1 and 2 faced to each other. Also, a mass film 4 having surface density between 0.1kg/m<2> and 3kg/m<2> and thickness between 0.1 mm and 3 mm is stacked on the inner surface of the porous elastic material 3, thereby forming a soundproof door. In this case, a powder contained sheet type material eraclosing powder made, for example, of silica having a grain size between 0.1 and 1.000μm and bulk density between 0.1 and 1.5g/m<3> with an acoustically transmissive surface sheet may be used, instead of the mass membrane 4. Furthermore, the powder may be mixed with fine fiber such as a metallic whisker having a spring constant equal to or less than 1×10<2> N/m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof door with improved sound insulation.

[0002]

2. Description of the Related Art The characteristics of soundproof doors used in audio / video rooms, piano practice rooms, and karaoke rooms are that they are heavier than general interior doors, and are easy to handle during transportation and construction. Was bad.

FIG. 9 shows a conventional general soundproof door having a relatively good sound insulation performance and a light weight. This soundproof door has a double panel structure in which an air space or a porous sound absorbing material such as glass wool or urethane foam is installed as a sound absorbing layer 11 between two surface plates 1 and 2 attached to a door frame 10. Things.

[0004] In such a soundproof door, the sound insulation performance (transmission loss) in a low sound range has a large effect on the overall sound insulation characteristics. The following two problems are involved in the sound insulation performance of a double panel structure. No.

[0005] 1. Since the above-mentioned porous sound absorbing material has a low sound absorption coefficient in a low sound range, the transmission loss in a low frequency range does not increase so much as compared with a case where the sound absorbing material is hollow.

2. A significant reduction in transmission loss at the resonance frequency frmd, caused by resonance in the low range characteristic of double panels.

[0007] The resonance frequency frmd in the above-described soundproof door having a double panel structure basically follows the following equation.

Frmd = (ρC ² / md) ^1/2 / (2π) where ρ in the above equation is the density of air (kg / m ³ ), and C
Is the speed of sound in air (m / s), m is the surface weight of the surface plates 1 and 2 (kg / m ² ), and d is the distance (m) between the surface plates 1 and 2.

From the above equation, the resonance frequency frmd of the double panel
It can be seen that it is necessary to use a very thick soundproof door in order to shift the frequency to an extremely low frequency range of about 100 Hz, which does not cause a problem in sound insulation performance. But,
Increasing the thickness of the soundproof door increases the transmission loss and increases the sound insulation performance. However, there is a limit in increasing the thickness due to design restrictions and the connection with the wall, which is not practical.

In order to solve the above problem, for example, by inserting a sound absorbing material having a high sound absorbing property in a low sound range between the surface plates 1 and 2, an improvement in sound insulating performance can be expected. However, a generally widely used porous sound absorbing material has almost no sound absorbing characteristics in a low sound range due to its sound absorbing mechanism, so that improvement in sound insulation performance in this sound range cannot be expected.

Also, as a general problem of the soundproof door,
There is a problem that the weight is larger than that of a general interior door and the handling is poor. That is, in order to obtain the high sound insulation required for the soundproof door, it is necessary to increase the surface weight of the surface plates 1 and 2 in accordance with the mass rule to improve the sound insulation. However, if the surface weight of the surface plates 1 and 2 of the soundproof door is increased, the transmission loss increases, and the sound insulation performance increases. However, the effect of improving the sound insulation performance is small for the increase in weight, and in order to obtain higher sound insulation performance. Is too heavy to be practical.

Therefore, if the sound insulation performance can be improved without increasing the weight or thickness, the sound insulation performance is also excellent acoustically, the weight is light, and the handleability during construction is improved.
It is possible to realize a soundproof door with a high degree of freedom against restrictions on design and restrictions such as connection with a wall.

[0013]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a soundproof door which has improved sound insulation performance, is lightweight and thin, has improved handleability during construction, and has a high degree of freedom in design. The task is to

[0014]

According to a first aspect of the present invention, there is provided an ink jet recording head having two face plates 1 and 2 opposed to each other, and a porous plate is provided inside at least one of the face plates 1 and 2. A porous elastic body 3 is laminated, and a mass film 4 is further laminated inside the porous elastic body 3 so that the bulk density of the porous elastic body 3 is 100 kg / m ³ or less and the Young's modulus is 1.0. × and 10 ³ ~1. 0 × 10 in the ⁶ N / m ² range, constitutes a characterized in that it comprises a surface density of the mass layer 4 as ^{0. 1kg / m 2 ~3kg / m} 2.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, a resin sheet is used as the mass film 4, and the thickness of the resin sheet is in the range of 0.1 to 3 mm. Make up.

According to a third aspect of the present invention, in the first aspect of the invention, the powder 5 exhibiting a sound absorbing effect is closed with an acoustically transparent top sheet 6 to form a powder-containing sheet 7. The powder-containing sheet 7 is used in place of the mass film 4.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the powder 5 has a particle size of 0.1 to 1000 μm.
And the bulk density is in the range of 0.1 to 1.5 g / cm ³ .

According to a fifth aspect of the present invention, in the third aspect of the present invention, the powder 5 is mixed with fine fibers 5a having a spring constant of 1 × 10 ² N / m or less. ing.

According to a sixth aspect of the present invention, in the third aspect of the present invention, a spring constant of 1 × 10
It is characterized in that it is made by adhering a microfiber 5a of ² N / m or less.

[0020] The invention according to claim 7 is the invention according to claims 1 to 6.
In the invention according to any one of the above, a porous elastic body 3 is disposed on both inner sides of the two face plates 1 and 2 arranged opposite to each other,
Porous elastic body 3 and mass film 4 or powder-containing sheet 7
Are alternately laminated, and these surface plates 1 and 2, the porous elastic body 3, and the mass film 4 or the powder-containing sheet-like material 7 are formed as an integrated laminate. doing.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view conceptually showing one soundproof door of this embodiment. As shown in this figure, this soundproof door has two face plates 1 and 2 arranged to face each other, and a porous elastic body 3 is laminated inside at least one of these face plates 1 and 2; Further, a mass film 4 is laminated inside the porous elastic body 3. The bulk density of the porous elastic body 3 is set to 100 kg / m ³ or less, the Young's modulus is set in a range of 1.0 × 10 ³ to 1.0 × 10 ⁶ N / m ² , and the mass film 4 is formed. the surface density is set to ^{0. 1kg / m 2 ~3kg / m} 2. Further, the front plates 1 and 2 are attached to the door frame 11 and formed.

In this figure, the porous elastic body 3 and the mass film 4 are laminated on the surface plates 1 and 2 on both sides, respectively. Good thing.

In general, in such a double-panel structure using the surface plates 1 and 2, the sound insulation performance is greatly reduced near the resonance frequency frmd. In order to improve the sound insulation, a new resonance system having a laminated structure of the porous elastic body 3 and the mass film 4 and having a resonance frequency f1 is installed on the surface plates 1 and 2. doing. By setting the resonance frequency f1 near the resonance frequency frmd of the double-panel structure, the resonance phenomenon of the surface plates 1 and 2 is suppressed by the dynamic vibration absorbing mechanism. Can be reduced.

FIG. 2 is an explanatory diagram schematically showing the above soundproof door. In this figure, a porous elastic body 3 (thickness; t1, Young's modulus; E1) and a mass film 4 (surface weight; M1)
) Shows that a new resonance system (resonance frequency f) of a spring-mass system is provided on the surface plates 1 and 2 (surface weight;
1) It is installed as

The resonance frequency f1 of the laminated structure of the porous elastic body 3 and the mass film 4 is expressed as follows.

F1 = (K1 / M1) ^1/2 / (2π) where K1 is the spring constant (N / m / m ² ) of the porous elastic body 3 per unit sectional area, and M1 is This is the surface weight (kg / m ² ) of the mass film 4.

K1 is represented by the following equation. K1 = E1 / t1, where E1 in the above equation is the Young's modulus (N / m ² ) of the porous elastic body 3, and t1 is the thickness (m) of the porous elastic body 3.

That is, by properly selecting the thickness and Young's modulus of the porous elastic body 3 provided on the surface plates 1 and 2 and the surface weight of the mass film 4, the resonance frequency f 1 is set to around the resonance frequency frmd of the double panel structure. It is necessary to bring it.

At this time, the porous elastic body 3 has a bulk density of 100 kg / m ³ or less and a Young's modulus of 1.0.
There is no particular limitation as long as it is within the range of 0 × 10 ³ to 1.0 × 10 ⁶ N / m ² , but usually, porous materials made of inorganic or organic fibers such as rock wool, glass wool, and nonwoven fabric A material or a foamed resin body such as urethane can be used.

The mass film 4 also has a surface density of 0.1 kg / m ² to 3 kg / m ² and functions as a mass (mass) in a spring-mass system resonance system. There is no particular limitation so long as the laminated structure with the porous elastic body 3 functions as a new resonance system (resonance frequency f1) when the surface plates 1 and 2 are vibrated by sound waves. Good.

Specifically, synthetic resin sheets such as vinyl chloride resin, vinyl acetate resin, polyethylene resin, polypropylene resin, polyurethane resin, etc., those obtained by filling them with inorganic powder as an extender, aluminum sheets, etc. Metal sheet and the like.

In the above-described spring-mass system resonance system, since the sheet-shaped mass film 4 is used as the mass (mass), the porous elastic body 3 and the mass film 4 are formed inside the soundproof door. This constitutes a membrane vibration type sound absorbing material. Therefore, when a sound wave enters the soundproof door, the porous elastic body 2 installed on the surface plates 1 and 2 and the mass film 4
In addition to suppressing the resonance phenomenon of the surface plates 1 and 2, it is possible to further improve the sound insulation of the soundproof door by the sound absorbing effect of the film vibration type sound absorbing material.

As a result, it is possible to improve the sound insulation performance without increasing the weight and thickness of the soundproof door, to improve the handleability at the time of construction by being lightweight, and to restrict the design and to cope with the wall. A soundproof door with a high degree of freedom against restrictions can be realized.

Further, a configuration using a powder-containing sheet material 7 instead of the mass film 4 may be employed.

FIG. 3 is a sectional view conceptually showing one example of the above-mentioned powder-containing sheet 7. This powder-containing sheet-like material 7 is a powder 7 that exhibits a sound absorbing effect by vibrating particles.
However, it is divided into several blocks by an acoustically transparent top sheet 6 and closed.

Even in the configuration using such a powder-containing sheet material 7, similarly to the case of the mass film 4, the surface plate 1,
The resonance frequency f2 can be brought near the resonance frequency frmd of the double panel structure by installing a spring-mass system resonance system (resonance frequency; f2) in 2 and the resonance of the surface plates 1 and 2 by the dynamic vibration absorption mechanism. The phenomenon can be suppressed, and as a result, it is possible to improve a decrease in sound insulation near the resonance frequency frmd.

The configuration using the powder-containing sheet 7 can be represented by the same model as that of FIG.
The powder-containing sheet material 7 corresponds to the mass film 4 which is a mass (mass) portion in the figure.

The resonance frequency f2 due to the laminated structure of the porous elastic body 3 and the powder-containing sheet 7 is substantially the same as that when the mass film 4 is used, and is expressed as follows.

F2 = (K1 / M2) ^1/2 / (2π) where M2 in the above equation is the surface weight (kg / m ² ) of the powder-containing sheet material 7.

K1 is represented by the following equation, just as described above. K1 = E1 / t1 That is, by selecting the thickness and Young's modulus of the porous elastic body 3 installed on the surface plates 1 and 2, the surface weight of the powder-containing sheet-like material 7, and the like, the resonance frequency f2 is set to a double panel structure. It is necessary to bring it near the resonance frequency frmd.

The powder-containing sheet 7 is not particularly limited as long as the powder 5 exhibiting a sound absorbing effect is formed into a sheet by being closed by an acoustically transparent top sheet 6. Any material that functions as a mass (mass) in a spring-mass resonance system may be used. However, in the laminated structure with the porous elastic body 3, when the surface plates 1 and 2 are vibrated by sound waves, it is necessary to function as a new resonance system (resonance frequency f2). It is necessary to appropriately select the physical properties of the porous elastic body 3 and the powder-containing sheet material 7 so that f2 can be designed around the resonance frequency frmd of the double panel structure.

FIGS. 4 and 5 are sectional views or exploded perspective views conceptually showing different specific examples of the powder-containing sheet material 7. FIG.

The powder-containing sheet-like material 7 shown in FIG. 4 has the above-mentioned powder 5 filled in the space inside the sheet-like fibers 8 such as nonwoven fabric, glass wool, rock wool, etc. It has a closed structure.

The powder-containing sheet 7 shown in FIG.
Is a polymer sheet in which the powder 5 is meshed,
It has a structure in which the inside of a cell structure 9 such as a paper honeycomb is filled and closed with an acoustically transparent top sheet 6. With such a structure, a decrease in the sound absorbing performance due to the bias of the powder 5 or the like is suppressed, and the handleability as a sheet material is excellent.

Examples of the powder 5 used in the powder-containing sheet 7 as described above include the following.

That is, usually, the particle size is 0.1 to 1000.
μm, bulk density of about 0.1 g / cm ³ to about 1.5
g / cm ³ range, upon sound wave incidence, a flat type having a substantially constant sound absorption coefficient at a specific frequency or higher, or a peak type having a peak in the frequency characteristic of the sound absorption coefficient, Examples thereof include a mixture of a powder of a granular material and a powder of fine fibers 5a having a spring constant of 1 × 10 ² N / m or less, or a powder to which the fine fibers 5a are attached.

More specifically, as the powder 5 having a flat type sound absorbing property, vermiculite (average particle size;
200-400 μm, bulk density: 0.1 g / cm ³ ), wet silica (average particle size: 400-500 μm, bulk density: about 0.1)
1-0.2 g / cm ³ ), soft calcium carbonate (average particle size;
1-2 μm, bulk density; about 0.4 g / cm ³ ), nylon powder (average particle size: 180-500 μm, bulk density: about 0.5 g / cm ³ ), calcined ferrite (average particle size: 1. 3
~ 1.5μm, bulk density; about 1.0g / cm ³ ), gold mica
(Average particle size: 650 μm, bulk density: about 0.5 to 0.6)
g / cm ³ ).

The powder 5 having a peak type sound absorbing characteristic
Examples thereof include silica, mica, and talc, and more specifically, gold mica (average particle size; 40 μm, bulk density; about 0.4 g / cm ³ ), wet silica (average particle size;
50 μm, bulk density; about 0.1 to 0.3 g / cm ³ ), spherical silica (average particle size: 3 to 28 μm, bulk density: about 0.3)
０0.9 g / cm ³ ), talc (average particle size: 1.5 to 9.4)
μm, bulk density; about 0.3 to 0.5 g / cm ³ ), fine acrylic powder (average particle size: 1 to 2 μm, bulk density: about 0.3 g / cm3)
cm ³ ), calcium silicate powder (average particle size: 20 to 30)
μm, bulk density: about 0.1 g / cm ³ ), pearlite powder (average particle size: 100 to 150 μm, bulk density: about 0.1)
０0.2 g / cm ³ ), fluororesin powder (average particle size: 5-2)
5 μm, bulk density: about 0.4 to 0.5 g / cm ³ ), bentonite (average particle size: 0.3 to 3.5 μm, bulk density: about 0.5 to 0.8 g / cm ³ ), shirasu balloon (Average particle size;
30 to 50 μm, bulk density: about 0.2 to 0.3 g / c
m ³ ), fused silica (average particle size: 5 to 32 μm, bulk density: about 0.5 to 0.8 g / cm ³ ), silicon carbide powder (average particle size: 0.4 to 5.0 μm, bulk density) About 0.6-1.
1 g / cm ³ ), nylon powder (average particle size: 5-250)
μm, bulk density; about 0.3 to 0.5 g / cm ³ ), acrylic powder (average particle size: 45 μm, bulk density: about 0.6 to 0.5 g / cm ³ )
7 g / cm ³ ), carbon fiber powder (average fiber diameter: 14-18 μm,
Fiber length 100-200 μm, bulk density; about 0.5-0.6 g /
cm ³ ), titanium dioxide powder (average particle size: 0.1 to 0.2)
5 μm, bulk density: about 0.5 to 0.7 g / cm ³ ), calcium carbonate powder (average particle size: 3 to 30 μm, bulk density: about 0.6 to 1.0 g / cm ³ ), vinyl chloride resin Powder (average particle size: 130 μm, bulk density: about 0.5 g / cm ³ ), barium ferrite magnetic powder (average particle size: 1.8 to 2.2 μm, bulk density: about 1.5 g / cm ³ ), silicon Powder (average particle size: 0.3 to 0.7 μm, bulk density: about 0.2 to 0.3)
g / cm ³ ).

Further, in the explanatory view of FIG. 6, an example of the powder 5 different from the above is conceptually shown. The powder 5 in this figure has fine fibers 5a adhered to the particle surface of the powder 5. Note that such microfibers 5a may be formed in an aggregated state and attached thereto.

By using the powder 5 as described above, the sound absorption characteristic can be further reduced in the sound range, and the thickness of the powder-containing sheet 7 can be reduced.

As the fine fibers 5a to be adhered to or mixed with the powder 5, metal whiskers, plastic fibers, vegetable fibers, glass fibers, a structure in which these are aggregated, and the like are used. More specifically, mention may be made of potassium titanate whiskers, silicon carbide whiskers, zinc oxide whiskers, calcium silicate needle powder, sepiolite and the like. The fiber system and fiber length are not particularly limited either, but usually the average fiber diameter is in the range of 0.1 μm to 10 μm, and the fiber length is in the range of several μm to several tens μm.

The microfibers 5a are not limited to those described above, but may have a spring constant of 1 × 10 ² N / m or less, preferably 10 N / m or less. Furthermore, the mixing ratio with the powder particles 7 and the method of attachment are not particularly limited.

The acoustically transparent top sheet 6 is not particularly limited as long as it can prevent the powder 5 from spilling. Examples thereof include breathable paper, woven fabric, nonwoven fabric sheet, glass cloth, etc., polymer sheets such as polyester sheet, polyethylene sheet and vinyl sheet having a thickness of about 50 μm or less, and metal foil such as aluminum foil. These sheets are arbitrarily selected according to the particle size of the powder 5 to be used, the filling amount, and the like.

Further, as described above, since the powder-containing sheet 7 is used as a mass (mass) in the spring-mass resonance system, the inside of the soundproof door is not in contact with the porous elastic body 3. It has a sound absorbing mechanism in which the powder-containing sheet-like materials 7 are stacked. That is, the porous elastic body 3 such as rock wool, glass wool, and urethane generally has almost no sound absorbing effect in a low frequency range, whereas the resonance of the powder-containing sheet-like material 7 using the porous elastic body 3 as a spring. This increases the sound absorbing effect in the low frequency range.

For this reason, when sound waves enter the soundproof door, the porous elastic body 3 installed on the front plates 1 and 2 suppresses the resonance phenomenon of the front plates 1 and 2 and also absorbs sound at low frequencies. By increasing the action, it is possible to further improve the sound insulation of the soundproof door.

FIGS. 7 and 8 are cross-sectional views conceptually showing one soundproof door of this embodiment, which has a different configuration from the above soundproof door.

In the soundproof door of FIG. 7, a porous elastic body 3 is disposed on both inner sides of two facing surface plates 1 and 2, and a mass film 4 is provided inside the porous elastic body 3. And these surface plates 1 and 2, the porous elastic body 3 and the mass film 4 are formed in an integrated laminate.

Further, in the soundproof door of FIG.
A porous elastic body 3 is arranged on both inner sides of the two surface plates 1 and 2,
Further, the mass membranes 4 are respectively disposed inside the porous elastic bodies 3, and the porous elastic bodies 3 are further disposed inside the mass elastic membranes 4. The porous elastic body 3, the two mass films 4 inside the porous elastic body 3, and the porous elastic body 3 inside the porous elastic body 3 are formed as an integrated laminate.

The replacement of the mass film 4 with the powder-containing sheet-like material 7 is the same as that described with reference to FIGS. 1 to 6 and does not cause any problem.

In such a soundproof door, when sound waves enter, the laminated structure of the porous elastic body 3 installed on the surface plates 1 and 2 and the mass film 4 and the powder-containing sheet-like material 7 causes It has the function of suppressing the first and second resonance phenomena. Moreover,
Since the resonance system composed of the porous elastic body 3 and the mass film 4 and the powder-containing sheet-like material 7 respectively installed on the surface plates 1 and 2 is connected and integrated, 2 has the function of suppressing vibration. That is, the function of suppressing the resonance phenomenon of the surface plates 1 and 2 is combined, and the sound insulation can be further improved.

As described above, the soundproof door according to the present embodiment is provided with two facing surface plates 1 and 2,
It has a structure in which a porous elastic body 3 and a mass film 4 and a powder-containing sheet material 7 laminated inside the porous elastic body 3 are laminated inside at least one of the two surface plates 1 and 2. Thus, the reduction of transmission loss near the resonance frequency frmd caused by resonance in the low frequency range peculiar to the double panel can be reduced, and the sound insulation in the low frequency range can be improved.

Further, in the spring-mass resonance system, since the mass film 4 and the powder-containing sheet 7 are used as masses (mass), the surface plates 1, 2 In addition to suppressing the resonance phenomenon of the surface plates 1 and 2 by the porous plate laminated structure with the porous elastic body 4 installed in
In addition to the sound absorbing effect of the powder-containing sheet material 7, the sound-absorbing effect of the laminated structure of the porous elastic body 3, the mass film 4, and the powder-containing sheet material 7 can further improve the sound insulation. It is.

[0064]

EXAMPLES Specific examples will be described below.

(Embodiment 1) The soundproof door of this embodiment has the structure shown in FIG. A 3 mm thick Lauan plywood is used as the surface plates 1 and 2. And
Inside each of the Rawan plywood, urethane having a thickness of 5 mm, which is a porous elastic body 3, and 0.5 mm, which is a mass film 4, are formed.
And a vinyl chloride sheet, respectively, and the inside is hollow.

The urethane has a density of 16 kg / m ³ , a Young's modulus of 1.0 × 10 ⁶ N / m ² , and a surface area of the vinyl chloride sheet of 0.5 kg / m ² . Lauan plywood, urethane, and vinyl chloride sheet are each laminated and adhered on the entire surface with an adhesive double-sided tape, and have sufficient strength in terms of handleability. Note that the bonding method is not limited to this embodiment, and for example, may be bonded and laminated using an adhesive or the like.

(Embodiment 2) The soundproof door of this embodiment is different from the embodiment 1 in that the mass film 4 is a powder-containing sheet 7 having a thickness of 2 mm.

This powder-containing sheet-like material 7 has the structure shown in FIG. 5, and contains fine fibers 5a on the surface of silica powder having an average particle diameter of 150 μm inside the cell structure 9 of paper honeycomb. Powder 5 obtained by adhering a silicon carbide whisker which is
The surface is covered with a polyester film, and is formed into a sheet.

(Embodiment 3) The soundproof door of this embodiment has the structure shown in FIG. As the surface plates 1 and 2,
A 3mm thick Rawan plywood is provided as in Example 1.
As the porous elastic body 3, a urethane having a thickness of 14 mm is used.
Is used. This powder-containing sheet-like material 7 has a cross-sectional structure as shown in FIG. It is formed into a sheet having a thickness of 2 mm by covering the surface with a polyester film having a thickness of 25 μm.

The above-mentioned rawan plywood, urethane and powder-containing sheet material 7 are laminated and adhered over the entire surface with an adhesive double-sided tape, as in Example 1.

The soundproof door of each of the above embodiments has a thickness of 30 mm.
The door frame 11 is formed in a size of 800 mm × 2000 mm.

Table 1 below shows the sound insulation performance and the weight of the soundproof door in the above embodiment, which are compared with those of the comparative example. Evaluation of sound insulation performance is based on JIS standard A141
6 (method of measuring sound transmission loss in a laboratory), and the results are shown as D values. Further, the comparative example has a hollow structure in which the porous elastic body 3, the mass film 4, the powder-containing sheet-like material 7, and the like are not laminated on the surface plates 1 and 2.

[0073]

[Table 1]

The D value shown in the above table is based on JIS standard A1
Based on 416 (sound insulation grade of the building), a reference frequency characteristic of the sound insulation grade related to the spatial average sound pressure level difference is determined and set as a reference curve, and this reference curve is a numerical value of the sound pressure level difference (dB) indicated at 500 Hz. . Therefore, the greater the D value, the better the sound insulation performance.

As shown in the above table, in the soundproof door of the comparative example, the sound insulation performance was D-15 in the class D, and sufficient sound insulation as the soundproof door was not obtained. This is because the sound insulation performance is significantly reduced due to the resonance frequency frmd near 125 to 250 Hz.

On the other hand, the soundproof doors of Examples 1, 2 and 3 were all compared with those of the comparative example by 125 to 250.
The sound insulation performance around Hz is improved by about 10 dB or more. As a result, the performance of D-30 was obtained as the D grade.

As described above, it can be seen that all of the soundproof doors of the above embodiments are light in weight and significantly improved in sound insulation performance.

As described above, the soundproof door of the present invention includes the two face plates 1 and 2 facing each other, and the inside of at least one of the two face plates 1 and 2 is provided with the porous elastic body 3. And a structure in which a mass film 4 and a powder-containing sheet material 7 laminated on the inside thereof are laminated. For this reason, when a sound wave is incident, the resonance phenomenon of the surface plates 1 and 2 is suppressed by the laminated structure of the porous elastic body 3 and the mass film 4 and the powder-containing sheet material 7 installed on the surface plates 1 and 2. I do. Further, the sound absorption by the laminated structure of the porous elastic body 3, the mass film 4, and the powder-containing sheet material 7 can further improve the sound insulation.

[0079]

According to the first aspect of the present invention, a new spring-mass resonance system having a resonance frequency f1 is installed on the surface plate by the laminated structure of the porous elastic body and the mass film having appropriate physical property ranges. By setting the resonance frequency f1 near the resonance frequency frmd of the double panel structure, the resonance phenomenon of the surface plate is suppressed by the dynamic vibration absorbing mechanism, and as a result, the deterioration of the sound insulation near the resonance frequency frmd is improved. It has become possible.

Further, a membrane vibration type sound absorbing material can be constituted by the porous elastic body and the mass film, and the sound insulation of the soundproof door can be further improved by the sound absorbing effect of the film vibration type sound absorbing material. Becomes

As a result, it is possible to improve the sound insulation performance without increasing the weight and thickness of the soundproof door, to improve the lightness and handleability at the time of construction, and to restrict the design and to cope with the wall. A soundproof door with a high degree of freedom against restrictions has been realized.

According to the second aspect of the present invention, the effect of the first aspect of the present invention is achieved by using a 0.1 to 3 mm resin sheet generally easily available as a mass film.

According to the third aspect of the present invention, a spring-mass resonance system can be similarly obtained by using a powder-containing sheet instead of the mass film, and the effect of the first aspect of the present invention can be obtained. Has been played.

According to the fourth aspect of the present invention, the effect of the third aspect of the present invention is exhibited by setting the particle diameter and the bulk density of the powder in a range suitable for exhibiting a sound absorbing effect.

According to the fifth aspect of the present invention, the sound insulation in the low frequency range is further improved by the mixed fine fibers.

According to the sixth aspect of the present invention, the sound insulation in the low range is further improved by the fine fibers attached to the surface.

According to the seventh aspect of the present invention, the resonance system comprising the porous elastic body and the mass film or the sheet material containing the powder is:
Due to the integrated connection, there is a function of better suppressing the surface plate vibration at the time of sound wave incidence. That is, the effect of suppressing the resonance phenomenon of the surface plate is combined, and it is possible to further improve the sound insulation.

[Brief description of the drawings]

FIG. 1 is a sectional view conceptually showing one soundproof door according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram schematically showing the soundproof door according to the first embodiment.

FIG. 3 is a sectional view conceptually showing one example of a powder-containing sheet material in the soundproof door of the embodiment.

FIG. 4 is a sectional view conceptually showing a different specific example of the above-mentioned powder-containing sheet material.

FIG. 5 is a perspective view conceptually showing a different specific example of the above powder-containing sheet material.

FIG. 6 is an explanatory view conceptually showing an example of a powder used in the above-mentioned powder-containing sheet.

FIG. 7 is a sectional view conceptually showing one soundproof door of the embodiment.

FIG. 8 is a sectional view conceptually showing one soundproof door of the embodiment.

FIG. 9 is a sectional view conceptually showing a conventional soundproof door.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface plate 2 Surface plate 3 Porous elastic body 4 Mass film 5 Powder 5a Microfiber 6 Surface sheet 7 Powder containing sheet material 8 Sheet fiber 9 Cell structure 10 Door frame 11 Sound absorbing layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor: Hayato Inada 1048 Odakadoma, Kadoma City, Osaka Inside Matsushita Electric Works, Ltd.

Claims (7)

[Claims] 1. A method in which two surface plates are arranged to face each other, a porous elastic body is laminated inside at least one of these surface plates, and a mass film is further laminated inside the porous elastic body. Increase the bulk density of the porous elastic body to 100 kg / m ³
In addition to the following, the Young's modulus is set to 1.0 × 10 ³ to 1.0.
× 10 ⁶ N / m ^{2 and} the mass density of the mass film is 0.1
soundproof door, characterized by comprising as ^{kg / m 2 ~3kg / m 2} . 2. The soundproof door according to claim 1, wherein a resin sheet is used as the mass film, and the thickness of the resin sheet is in the range of 0.1 to 3 mm. 3. A powder exhibiting a sound absorbing effect is closed with an acoustically transparent top sheet to form a powder-containing sheet, and the powder-containing sheet is used in place of the mass film. The soundproof door according to claim 1, wherein the soundproof door is formed. 4. The particle size of the powder is 0.1 to 1000 μm.
With a soundproof door according to claim 3, characterized in that it comprises the bulk density as a range of 0. 1~1. 5g / cm ^3. 5. The soundproof door according to claim 3, wherein the powder is mixed with fine fibers having a spring constant of 1 × 10 ² N / m or less. 6. A spring constant of 1 × 10 on the particle surface of the powder.
4. The soundproof door according to claim 3, wherein fine fibers of ² N / m or less are adhered. 7. A porous elastic body is arranged on both inner sides of two opposed face plates, and the porous elastic body and a mass film or a powder-containing sheet are alternately laminated. The soundproof door according to any one of claims 1 to 6, wherein the surface plate, the porous elastic body, and the mass film or the sheet material containing the powder are formed in an integrated laminate.