JP6963418B2 - Sound absorbing panel - Google Patents

Description

The present invention relates to a sound absorbing panel that absorbs noise generated from vehicles, houses, public facilities, railways, roads, and the like.

In order to suppress the running of vehicles and the noise caused by so-called daily noise, the method of installing sound absorbing panels along the roadway, railroad track, site boundary, and adjacent land boundary has been often used and used. Various configurations have been proposed for the sound absorbing panel.

For example, in Patent Document 1, a sound absorbing material is incorporated in a hollow body formed by a front portion having a large number of openings and a back portion having sound insulation, and the sound absorbing material is made of an organic plastic fiber material. The thickness dimension of the sound absorbing material is 18 to 45 mm, a back air layer having a depth dimension of 5 to 40 mm is formed between the back surface portion and the sound absorbing material, and the thickness dimension of the hollow body is 25 to 60 mm. A thin soundproof panel characterized by this has been proposed by the applicant.

Japanese Unexamined Patent Publication No. 2001-193021

The thin soundproof panel shown in Patent Document 1 provides a soundproof panel having a small thickness with good sound absorption performance by providing a back air layer between a back surface portion having sound insulation and a sound absorbing material. Provides a sound absorbing panel having even better sound absorbing performance.

In order to achieve the above object, the present invention has the following configuration.
That is, the sound absorbing panel according to the present invention is arranged between the front plate having a through hole and arranged on the sound source side, the sound insulating plate arranged behind the front plate, and the sound insulating plate and the front plate. A sound absorbing means including a sound absorbing means, wherein a protective material, a first sound absorbing material, a resistance material and a second sound absorbing material are arranged in order from the sound source side, and the protective material, the first sound absorbing material, the first. The sound absorbing material, the resistance material, and the second sound absorbing material are all breathable, and the resistance material is arranged in a range of 3 mm from the center of the sound absorbing means in the front-rear direction to the flow resistance of the resistance material. Is larger than the flow resistance of the first sound absorbing material and the second sound absorbing material.

In the present invention, it is preferable that the first sound absorbing material and the second sound absorbing material have the same material, the same thickness, and the same ventilation performance.

Further, the sound absorbing panel according to the present invention is arranged between a front plate having a through hole and arranged on the sound source side, a sound insulating plate arranged behind the front plate, and the sound insulating plate and the front plate. It is a sound absorbing panel provided with the sound absorbing means, in which the protective material, the first sound absorbing material, the resistance material and the second sound absorbing material are arranged in order from the sound source side, and the protective material, the first The sound absorbing material, the resistance material, and the second sound absorbing material are all breathable, and the resistance material is located at the center of the sound absorbing means in the front-rear direction, and the first sound absorbing material and the second sound absorbing material are located. The sound absorbing material is of the same material, the same thickness, and the same ventilation performance, and the flow resistance of the resistance material is larger than the flow resistance of the first sound absorbing material and the second sound absorbing material. Is.

According to the sound absorbing panel according to the present invention, in the sound absorbing means, a protective material, a first sound absorbing material, a resistance material and a second sound absorbing material are arranged in order from the sound source side, and the protective material, the first sound absorbing material, and the like. Both the resistance material and the second sound absorbing material are breathable, and the resistance material is located at the center portion in the front-rear direction of the sound absorbing means or behind the center portion, and the flow of the resistance material. Since the resistance is larger than the flow resistance of the first sound absorbing material and the second sound absorbing material, noise can be effectively attenuated.

In the sound absorbing material according to the present invention, if the ventilation resistance of the protective material is 0.3 kPa · sec / m or less and the ventilation resistance of the resistance material is 0.1 to 3.0 kPa · sec / m, noise The damping effect of can be further improved.

Further, in the sound absorbing material according to the present invention, the ventilation resistance of the first sound absorbing material is 0.15 kPa · sec / m or more, and the ventilation resistance of the resistance material is 0.1 to 1.2 kPa · sec / m. If so, the noise attenuation effect can be further improved.

It is a front view which shows one Embodiment of the sound absorption panel which concerns on this invention. It is an enlarged cross-sectional view of the line AA of FIG. It is a schematic diagram of the sound absorbing means of FIG. It is a table which shows the Example of the sound absorbing means which concerns on this invention. It is a table which shows the Example of the sound absorbing means which concerns on this invention. It is a table which shows the comparative example of the sound absorbing means which concerns on this invention.

Embodiments of the present invention will be specifically described with reference to the drawings.
In the drawing, 1 is a sound absorbing panel. The sound absorbing panel 1 shown in FIG. 1 includes a main body 2 formed in a horizontally long rectangular box shape. The main body 2 includes a quadrangular frame body F in which left and right vertical frames 21 formed in a long body and upper and lower horizontal frames 22 formed in a square cylinder shape are assembled. A front plate 23 and a sound insulating plate 24 are attached to the front side and the rear side of the frame body F so as to close the opening of the portion surrounded by the vertical frame 21 and the horizontal frame 22, respectively, to form a hollow box. The main body 2 of the above is formed.

The front plate 23 is formed with a through hole h for connecting the inside and the outside of the main body 2. The through holes h are circular small holes penetrating the front plate 23, and are formed in large numbers so as to cover substantially the entire surface of the front plate 23 at intervals. For the sake of simplification of the drawings, the through holes h are shown only in a part of the four corners of the front plate 23 in FIG. 1, and the through holes h are not shown in FIG.

A rectangular plate-shaped sound absorbing means 3 is housed inside the main body 2. The sound absorbing means 3 is provided in a shape and size such that the upper, lower, left and right ends are located in the vicinity of the horizontal frame 22 and the vertical frame 21, respectively, and the noise incident on the inside through the through hole h of the front plate 23. Is provided so that sound can be absorbed efficiently. Further, the thickness of the sound absorbing means 3 in the front-rear direction is substantially the same as the distance between the front plate 23 and the sound insulating plate 24.

In the sound absorbing means 3, a protective material 31, a first sound absorbing material 32, and a second sound absorbing material 33 are arranged in this order from the sound source side, and further, between the first sound absorbing material 32 and the second sound absorbing material 33. The resistor material 34 is arranged.
The protective material 31 prevents foreign matter such as rainwater or dust that enters the inside of the main body 2 through the through hole h from coming into contact with the first sound absorbing material 32 behind.
Further, the protective material 31 has breathability. As a result, for example, a material having almost no air permeability, such as a film, may reflect noise and not exhibit sufficient sound absorption performance, but such a problem can be prevented.
Further, the protective material 31 can be formed by using a known material having better weather resistance than the first sound absorbing material 32. Further, as the protective material 31, a material obtained by subjecting the known material to a water repellent treatment can be used.

Examples of the material of the protective material 31 include polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly-1,4-dimethylcyclohexane terephthalate, and polyethylene naphthalate, and polyethylene. Polyolefin resins such as polypropylene and polypropylene, polyamide resins such as nylon and aramid fibers, acrylic resins, melamine resins, fluororesins such as ETFE, synthetic resins such as polyurethane resins, rubber materials such as EPDM, rayons, etc. Wood-based materials such as cellulose nanofibers and cotton, metals such as aluminum and stainless steel, carbon fibers, and inorganic materials such as glass wool, glass cloth, and rock wool can be used. Moreover, each of the above-mentioned materials may be selected or used in combination.
When a non-woven fabric made of a fiber-based material is used as the protective material 31, it may be formed on a cloth-like sheet body or a cotton-like body.

The first sound absorbing material 32 is a breathable material arranged behind the protective material 31, and is known to be used as a sound absorbing material such as a woven fabric made of a fiber-based material, a non-woven fabric, and a foam made of a synthetic resin. Members can be used.

The second sound absorbing material 33 is a breathable material arranged behind the first sound absorbing material 32, and like the first sound absorbing material 32, is made of a woven fabric made of a fiber-based material, a non-woven fabric, or a synthetic resin. A known member used as a sound absorbing material for a sound absorbing panel, such as a foam material, can be used.

The materials of the first sound absorbing material 32 and the second sound absorbing material 33 include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly-1,4-dimethylcyclohexane terephthalate, and the like. Polyester resins such as polyethylene naphthalate, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon and aramid fibers, synthetic resins such as acrylic resins, melamine resins and polyurethane resins, and rubber materials such as EPDM. , Wood-based materials such as rayon, cellulose nanofibers and cotton, metals such as aluminum and stainless steel, carbon fibers, inorganic materials such as glass wool and rock wool, etc. can be used. Moreover, each of the above-mentioned materials may be selected or used in combination.
When a non-woven fabric made of a fiber-based material is used for one or both of the first sound absorbing material 32 and the second sound absorbing material 33, a cloth-like sheet body or a plurality of laminated sheets may be formed. It may be formed into a cotton-like body.

The first sound absorbing material 32 and the second sound absorbing material 33 are preferable because they can be shared if they have the same material, the same thickness, and the same ventilation performance, but are not particularly limited. For example, the first sound absorbing material 32 and the second sound absorbing material 33 may be made of the same material or different materials. Further, the first sound absorbing material 32 and the second sound absorbing material 33 may be made of the same material or have different ventilation performances. For example, the flow resistance of the second sound absorbing material 33 may be made larger than that of the first sound absorbing material 32, or conversely, it may be made smaller.

The thickness of the first sound absorbing material 32 is preferably 15 mm or more. If it is thinner than this, the sound absorbing performance of the sound absorbing means 3 tends to deteriorate. On the other hand, the thickness of the second sound absorbing material 33 is preferably 5 mm or more. If the thickness is less than 5 mm, molding and shape maintenance become difficult.

As described above, the resistance material 34 is arranged between the first sound absorbing material 32 and the second sound absorbing material 33. As a result, a part of the sound incident on the sound absorbing means 3 and passing through the first sound absorbing material 32 is reflected by the resistor material 34, and a part of the reflected sound is absorbed by the first sound absorbing material 32. In the other part, it is presumed that the incident sound and the reflected sound cancel each other out due to the phase difference caused by the reflection of each material, thereby improving the sound absorption performance.

Further, the resistance material 34 is formed of a breathable material, and a part of the noise passes through and is absorbed by the second sound absorbing material 33, and further, due to the phase difference caused by the reflection by the sound insulating plate 24, the resistance material 34 is formed. It is presumed that the incident sound and the reflected sound cancel each other out, and that these are combined to enhance the sound absorbing performance of the sound absorbing means 3.

Since the resistance material 34 is provided to reflect a part of the sound incident on the first sound absorbing material 32, the first sound absorbing material 32 and the resistance material 34 are integrally arranged. It may be attached to the rear surface of the 32, or may be arranged with a gap on the rear surface side of the first sound absorbing material 32 or without providing a gap. Further, it may be attached to the front surface side of the second absorbent material 32.

In the sound absorbing means 3, the resistor 34 is located at the center of the sound absorbing means 3 in the front-rear direction or behind the center. As a result, the sound absorbing performance of the sound absorbing means 3 is improved as compared with the form in which the first sound absorbing material 32 and the second sound absorbing material 33 are continuously arranged in the front-rear direction without using the resistance material 34. I understood. By the way, it is thought that the sound absorbing performance of the sound absorbing means 3 changes by using the resistance material 34. However, by arranging the resistance material 34 at a specific position as described above, as will be described later, a relatively high frequency It was found that the noise is effectively absorbed and the sound absorption performance is improved.

Regarding the position of the resistance material 34, the central portion in the front-rear direction of the sound absorbing means 3 is the position where the resistance material 34 is arranged when the same material is used for the first sound absorbing material 32 and the second sound absorbing material 33. Although it is assumed, even a slight difference in the thickness of the protective material 31 and the resistance material 34 or the thickness of the sound absorbing materials 32 and 33 may deviate from the center in the front-rear direction. Therefore, even if the position of the resistor material 34 is different due to the influence of the thickness of each material, the sound absorbing performance of the sound absorbing means 3 is considered to be not significantly different from the center of the sound absorbing means 3 in the front-rear direction and its vicinity. The range including is the central part in the front-rear direction. That is, if the position of the resistor member 34 is arranged in the vicinity of 5 mm from the center in the front-rear direction to the front side, the sound absorption performance of the sound absorbing means 3 tends to deteriorate, and the central portion in the front-rear direction is exactly 3 mm in the front-rear direction from the center. The part that includes the range.

Further, in the sound absorbing means 3, the flow resistance of the resistance material 34 is made larger than the flow resistance of the first sound absorbing material 32 and the second sound absorbing material 33. As a result, a part of the noise transmitted through the first sound absorbing material 32 is easily reflected by the resistor material 34, and the passing noise can be further reduced by the second sound absorbing material 33.

Regarding the relationship between the protective material 31 and the resistance material 34, the ventilation resistance of the protective material 31 is 0.3 kPa · sec / m or less, and the ventilation resistance of the resistance material 34 is 0.1 to 3.0 kPa · sec / m. Is preferable. If the ventilation resistance of the protective material 31 exceeds 0.3 kPa · sec / m, noise is likely to be reflected by the protective material 31, and the sound absorbing performance of the sound absorbing means 3 may deteriorate. Further, if the ventilation resistance of the resistance material 34 exceeds 3.0 kPa · sec / m, it becomes difficult for noise to propagate from the resistance material 34 to the second sound absorbing material 33, and the sound absorbing performance of the sound absorbing means 3 may deteriorate. ..

Regarding the relationship between the first sound absorbing material 32 and the resistance material 34, the ventilation resistance of the first sound absorbing material 32 is 0.15 kPa · sec / m or more, and the ventilation resistance of the resistance material 34 is 0.1 to 1. It is more preferably .2 kPa · sec / m. As a result, the sound absorbing performance is superior to that of the sound absorbing means made of only the protective material 31 and glass wool, which is generally considered to have excellent sound absorbing performance.

The sound absorbing means 3 of the sound absorbing panel 1 according to the present invention will be described below.

<Example 1>
The protective material 31, the first sound absorbing material 32, the resistance material 34, and the second sound absorbing material 33 are arranged in this order from the sound source side.
The protective material 31 is a glass cloth having a thickness of 0.16 mm, a basis weight of 139 g / m2, a flow resistance of 100.0 kPa · sec / m2, and a ventilation resistance of 0.016 kPa · sec / m.
The first sound absorbing material 32 and the second sound absorbing material 33 are both cotton-like non-woven fabrics made of polyethylene terephthalate resin fibers, and have a thickness of 25 mm, a density of 22 g / m2, a flow resistance of 3.8 kPa · sec / m2, and a ventilation resistance of 0. .095 kPa · sec / m, using
The resistor material 34 is a spunbonded non-woven fabric made of polyester resin fiber, which has a thickness of 0.39 mm, a grain size of 125 g / m2, a flow resistance of 1313.3 kPa · sec / m2, and a ventilation resistance of 0.512 kPa · sec / m. A sound absorbing means 3 having a total thickness of about 51 mm was produced.

<Example 2>
Examples except that the first sound absorbing material 32 and the second sound absorbing material 33 have a thickness of 25 mm, a density of 44 g / m2, a flow resistance of 7.8 kPa · sec / m2, and a ventilation resistance of 0.195 kPa · sec / m. A sound absorbing means 3 having a total thickness of about 51 mm was produced in the same manner as in 1.

<Example 3>
Examples except that the first sound absorbing material 32 and the second sound absorbing material 33 have a thickness of 25 mm, a density of 55 g / m2, a flow resistance of 13.8 kPa · sec / m2, and a ventilation resistance of 0.345 kPa · sec / m. A sound absorbing means 3 having a total thickness of about 51 mm was produced in the same manner as in 1.

<Example 4>
The first sound absorbing material 32 and the second sound absorbing material 33 are all made of glass wool, except that the thickness is 25 mm, the density is 32 g / m2, the flow resistance is 13.3 kPa · sec / m2, and the ventilation resistance is 0.333 kPa · sec / m. Made a sound absorbing means 3 having a total thickness of about 51 mm in the same manner as in Example 1.

<Example 5>
The first sound absorbing material 32 and the second sound absorbing material 33 are both foamed melamine foams, having a thickness of 25 mm, a density of 10 g / m2, a flow resistance of 17.0 kPa · sec / m2, and a ventilation resistance of 0.425 kPa · sec / m. A sound absorbing means 3 having a total thickness of about 51 mm was produced in the same manner as in Example 1 except for the above.

<Example 6>
The first sound absorbing material 32 has a thickness of 30 mm, a density of 44 g / m2, a flow resistance of 7.8 kPa · sec / m2, and a ventilation resistance of 0.234 kPa · sec / m, and the second sound absorbing material 33 has a thickness of 20 mm and a density of 44 g. A sound absorbing means 3 having a total thickness of about 51 mm was produced in the same manner as in Example 2 except that the flow resistance was 7.8 kPa · sec / m2, the ventilation resistance was 0.156 kPa · sec / m.

<Example 7>
The first sound absorbing material 32 has a thickness of 45 mm, a density of 44 g / m2, a flow resistance of 7.8 kPa · sec / m2, and a ventilation resistance of 0.351 kPa · sec / m, and the second sound absorbing material 33 has a thickness of 5 mm and a density of 44 g. A sound absorbing means 3 having a total thickness of about 51 mm was produced in the same manner as in Example 2 except that the flow resistance was set to / m2, the flow resistance was set to 7.8 kPa · sec / m2, and the ventilation resistance was set to 0.039 kPa · sec / m.

<Example 8>
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.39 mm, the basis weight is 100 g / m2, the flow resistance is 278.6 kPa · sec / m2, and the ventilation resistance is 0.110 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 9>
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.45 mm, the basis weight is 165 g / m2, the flow resistance is 2429.9 kPa · sec / m2, and the ventilation resistance is 1.090 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 10>
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.58 mm, the grain size is 200 g / m2, the flow resistance is 1206.9 kPa · sec / m2, and the ventilation resistance is 0.700 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 11>
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.67 mm, the basis weight is 260 g / m2, the flow resistance is 2068.7 kPa · sec / m2, and the ventilation resistance is 1.390 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 12>
The protective material 31 is a short fiber non-woven fabric made of polyester resin fiber, except that the thickness is 0.39 mm, the basis weight is 38 g / m2, the flow resistance is 9.3 kPa · sec / m2, and the ventilation resistance is 0.004 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 13>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.34 mm, the basis weight is 80 g / m2, the flow resistance is 487.1 kPa · sec / m2, and the ventilation resistance is 0.166 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 14>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.22 mm, the basis weight is 70 g / m2, the flow resistance is 1171.8 kPa · sec / m2, and the ventilation resistance is 0.258 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 15>
A sound absorbing means 3 having a layer thickness of about 41 mm was produced in the same manner as in Example 2 except that the thickness of the first sound absorbing material 32 was 20 mm and the thickness of the second sound absorbing material 33 was 20 mm.

<Example 16>
A sound absorbing means 3 having a layer thickness of about 61 mm was produced in the same manner as in Example 2 except that the thickness of the first sound absorbing material 32 was 30 mm and the thickness of the second sound absorbing material 33 was 30 mm.

<Example 17>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, having a thickness of 0.39 mm, a basis weight of 100 g / m2, a flow resistance of 278.6 kPa · sec / m2, and a ventilation resistance of 0.110 kPa · sec / m.
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.45 mm, the basis weight is 165 g / m2, the flow resistance is 2429.9 kPa · sec / m2, and the ventilation resistance is 1.090 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 18>
The resistor material 34 is a melt-blown non-woven fabric made of polypropylene resin fiber, except that the thickness is 0.644 mm, the grain size is 60 g / m2, the flow resistance is 4385.1 kPa · sec / m2, and the ventilation resistance is 2.824 kPa · sec / m. A sound absorbing means 3 having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Example 19>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, having a thickness of 0.39 mm, a basis weight of 38 g / m2, a flow resistance of 9.3 kPa · sec / m2, and a ventilation resistance of 0.004 kPa · sec / m.
The thickness of the first sound absorbing material 32 is set to 35 mm.
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, having a thickness of 0.58 mm, a basis weight of 200 g / m2, a flow resistance of 1206.9 kPa · sec / m2, and a ventilation resistance of 0.700 kPa · sec / m.
A sound absorbing means 3 having a layer thickness of about 61 mm was produced in the same manner as in Example 2 except that the thickness of the second sound absorbing material 33 was set to 25 mm.

<Example 20>
The layer thickness of the second sound absorbing material 33 was about 51 mm in the same manner as in Example 2 except that the thickness of the second sound absorbing material 33 was 25 mm, the density was 22 g / m2, the flow resistance was 3.8 kPa · sec / m2, and the ventilation resistance was 0.095 kPa · sec / m. The sound absorbing means 3 of the above was produced.

<Example 21>
The first sound absorbing material 32 has a thickness of 25 mm, a density of 22 g / m2, a flow resistance of 3.8 kPa · sec / m2, and a ventilation resistance of 0.095 kPa · sec / m.
The second sound absorbing material 33 was made of glass wool and had a thickness of 25 mm, a density of 32 g / m2, a flow resistance of 13.3 kPa · sec / m2, and a ventilation resistance of 0.333 kPa · sec / m. A sound absorbing means 3 having a thickness of about 51 mm was produced.

<Comparative example 1>
The protective material 31 and the first sound absorbing material 32 are arranged in order from the sound source side, that is, the resistance material 34 is not arranged and the first sound absorbing material 32 and the second sound absorbing material 33 are integrally arranged. The protective material 31 is a glass cloth having a thickness of 0.16 mm, a basis weight of 139 g / m2, a flow resistance of 100.0 kPa · sec / m2, and a ventilation resistance of 0.016 kPa · sec / m.
The first sound absorbing material 32 is a cotton-like non-woven fabric made of polyethylene terephthalate resin fiber, which has a thickness of 50 mm, a density of 22 g / m2, a flow resistance of 3.8 kPa · sec / m2, and a ventilation resistance of 0.190 kPa · sec / m. A sound absorbing means having a total thickness of about 50 mm was prepared by using the material.

<Comparative example 2>
The total thickness of the first sound absorbing material 32 is about 50 mm in the same manner as in Comparative Example 1 except that the thickness of the first sound absorbing material 32 is 50 mm, the density is 44 g / m2, the flow resistance is 7.8 kPa · sec / m2, and the ventilation resistance is 0.390 kPa · sec / m. The sound absorbing means of the above was prepared.

<Comparative example 3>
The total thickness of the first sound absorbing material 32 is about 50 mm in the same manner as in Comparative Example 1 except that the thickness of the first sound absorbing material 32 is 50 mm, the density is 55 g / m2, the flow resistance is 13.8 kPa · sec / m2, and the ventilation resistance is 0.690 kPa · sec / m. The sound absorbing means of the above was prepared.

<Comparative example 4>
The first sound absorbing material 32 was made of glass wool and had a total thickness of 50 mm, a density of 32 g / m2, a flow resistance of 13.3 kPa · sec / m2, and a ventilation resistance of 0.665 kPa · sec / m in the same manner as in Comparative Example 1. A sound absorbing means having a thickness of about 50 mm was produced.

<Comparative example 5>
Comparative Example 1 except that the first sound absorbing material 32 was a foamed resin foamed melamine foam having a thickness of 50 mm, a density of 10 g / m2, a flow resistance of 17.0 kPa · sec / m2, and a ventilation resistance of 0.850 kPa · sec / m. In the same manner as above, a sound absorbing means having a total thickness of about 50 mm was produced.

<Comparative Example 6>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.34 mm, the basis weight is 80 g / m2, the flow resistance is 487.1 kPa · sec / m2, and the ventilation resistance is 0.166 kPa · sec / m. A sound absorbing means having a total thickness of about 50 mm was produced in the same manner as in Comparative Example 1.

<Comparative Example 7>
A sound absorbing means having a layer thickness of about 51 mm was produced in the same manner as in Example 2 except that the thickness of the first sound absorbing material 32 was 20 mm and the thickness of the second sound absorbing material 33 was 30 mm.
That is, the protective material 31, the first sound absorbing material 32, the resistance material 34, and the second sound absorbing material 33 are arranged in this order from the sound source side.
The protective material 31 is a glass cloth having a thickness of 0.16 mm, a basis weight of 139 g / m2, a flow resistance of 100.0 kPa · sec / m2, and a ventilation resistance of 0.016 kPa · sec / m.
The first sound absorbing material 32 is a cotton-like non-woven fabric made of polyethylene terephthalate resin fiber, which has a thickness of 20 mm, a density of 22 g / m2, a flow resistance of 3.8 kPa · sec / m2, and a ventilation resistance of 0.095 kPa · sec / m. Use,
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, which has a thickness of 0.39 mm, a grain size of 125 g / m2, a flow resistance of 1313.3 kPa · sec / m2, and a ventilation resistance of 0.512 kPa · sec / m. The first sound absorbing material 32 is a cotton-like non-woven fabric made of polyethylene terephthalate resin fiber, which has a thickness of 30 mm, a density of 22 g / m2, a flow resistance of 3.8 kPa · sec / m2, and a ventilation resistance of 0.095 kPa · sec / m. A sound absorbing means having a total thickness of about 51 mm was produced by using the material.

<Comparative Example 8>
A sound absorbing means having a layer thickness of about 51 mm was produced in the same manner as in Example 2 except that the thickness of the first sound absorbing material 32 was 15 mm and the thickness of the second sound absorbing material 33 was 35 mm.

<Comparative Example 9>
A composite non-woven fabric in which the resistance material 34 is supported by nanofibers (NF) made of polyvinylidene fluoride (PVDF) on a spunbonded non-woven fabric made of polyester resin fibers. The thickness is 0.3 mm, the grain size is 123 g / m2, and the flow resistance is 12058. A sound absorbing means having a layer thickness of about 51 mm was produced in the same manner as in Example 2 except that the ventilation resistance was set to .8 kPa · sec / m2 and the ventilation resistance was 3.680 kPa · sec / m.

<Comparative Example 10>
The layer thickness was the same as in Example 2 except that the resistance material 34 was made of glass cloth and had a thickness of 0.16 mm, a basis weight of 139 g / m2, a flow resistance of 100 kPa · sec / m2, and a ventilation resistance of 0.016 kPa · sec / m. A sound absorbing means having a thickness of about 51 mm was produced.

<Comparative Example 11>
The protective material 31 is a short fiber non-woven fabric made of polyester resin fibers, having a thickness of 0.39 mm, a basis weight of 38 g / m2, a flow resistance of 9.310 kPa · sec / m2, and a ventilation resistance of 0.004 kPa · sec / m.
The layer thickness was the same as in Example 2 except that the resistance material 34 was made of glass cloth and had a thickness of 0.16 mm, a basis weight of 139 g / m2, a flow resistance of 100 kPa · sec / m2, and a ventilation resistance of 0.016 kPa · sec / m. A sound absorbing means having a thickness of about 51 mm was produced.

<Comparative Example 12>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, having a thickness of 0.22 mm, a basis weight of 70 g / m2, a flow resistance of 1171.8 kPa · sec / m2, and a ventilation resistance of 0.258 kPa · sec / m.
The resistance material 34 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.39 mm, the basis weight is 100 g / m2, the flow resistance is 278.6 kPa · sec / m2, and the ventilation resistance is 0.110 kPa · sec / m. A sound absorbing means having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Comparative Example 13>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, except that the thickness is 0.39 mm, the basis weight is 125 g / m2, the flow resistance is 1311.3 kPa · sec / m2, and the ventilation resistance is 0.511 kPa · sec / m. A sound absorbing means having a layer thickness of about 51 mm was produced in the same manner as in Example 2.

<Comparative Example 14>
The protective material 31 is a spunbonded non-woven fabric made of polyester resin fiber, having a thickness of 0.34 mm, a basis weight of 80 g / m2, a flow resistance of 487.1 kPa · sec / m2, and a ventilation resistance of 0.166 kPa · sec / m.
A sound absorbing means having a layer thickness of about 36 mm was produced in the same manner as in Example 2 except that the thickness of the first sound absorbing material 32 was set to 10 mm.

A method for measuring the flow resistance and the ventilation resistance of each member constituting the sound absorbing means 3 of Examples 1 to 21 and the sound absorbing means of Comparative Examples 1 to 14 will be described.
First, the members constituting the first sound absorbing material 32 and the second sound absorbing material 33 were cut into a circle having a diameter of 90 mm and used as a measurement sample.
Further, each member constituting the protective material 31 and the resistance material 34 was cut into squares having a length of 100 mm and a width of 100 mm, respectively, and used as measurement samples.
Next, the aeration resistance of each of the above measurement samples was measured with an aeration tester (manufactured by Kato Tech Co., Ltd., model: KES-F8-AP1).
Finally, the measured aeration resistance was divided by the value of the thickness of the measurement sample to calculate the value of the flow resistance.
4 to 6 are tables showing physical property values such as flow resistance and ventilation resistance of each member constituting each sound absorbing means of Examples 1 to 21 and Comparative Examples 1 to 14, and the sound absorbing coefficient of each sound absorbing means. .. The flow resistance and ventilation resistance of each member measured and calculated by the above procedure are as shown in the tables of FIGS. 4 to 6. In addition, in the material of each member, for example, polyester terephthalate may be described in PET or the like, or may be partially omitted or abbreviated.

<Measurement method of sound absorption coefficient>
A method for measuring the sound absorption coefficient (vertically incident sound absorption coefficient) of the sound absorbing means 3 of Examples 1 to 21 and Comparative Examples 1 to 14 will be described.
First, each of the sound absorbing means 3 of Examples 1 to 21 and Comparative Examples 1 to 14 was cut into a circle having a diameter of 29 mm and used as a measurement sample.
Next, the vertical incident sound absorption coefficient of each of the above measurement samples was measured based on JIS A 1405.
Specifically, using the vertical incident sound absorption coefficient measurement system 4206 type acoustic impedance tube (manufactured by Brüel & Kjä) and the vertical incident sound absorption coefficient measurement software MS1021 (manufactured by Spectris Co., Ltd.), the frequency range is 500 Hz or more and 6400 Hz or less. Then, it was measured every 2 Hz.
Finally, in the measured values of the vertically incident sound absorption coefficient measured by the above method, the sound absorption coefficient at the 1/3 octave band center frequency of 2500, 3150, 4000 Hz is calculated, and the sound absorption coefficient at the three center frequencies is calculated. The simple average value was taken as the sound absorption coefficient.
The values of the sound absorption coefficient of each sound absorbing means 3 calculated by the above procedure are as shown in the tables of FIGS. 4 to 6.

As a result of comparing the sound absorbing rates of Examples 1 to 21 and Comparative Examples 1 to 14, the sound absorbing means 3 of each of Comparative Examples 1 to 14 was 0.97 or less, but the sound absorbing means of each of Examples 1 to 21 was obtained. Means 3 was able to confirm a good value of 0.97 or more. That is, the sound absorption coefficient of Comparative Example 4 using glass wool, which is generally considered to be excellent as a sound absorbing material, is 0.97, which is the best among Comparative Examples 1 to 14, and is made of resin fiber as the sound absorbing material. Although the non-woven fabric and the foamed resin are inferior to the sound absorbing performance of glass wool, the sound absorbing coefficient became 0.97 or more by arranging the resistor material 34 as shown in the sound absorbing means 3 of Examples 1 to 21.

Further, by setting the ventilation resistance of the first sound absorbing material 32 to 0.15 kPa · sec / m or more and the ventilation resistance of the resistance material to 1.2 kPa · sec / m or less, the sound absorbing coefficient of the sound absorbing means 3 can be increased. It is 0.98 or more, which is more preferable.

The value calculated by simply averaging the frequencies of 2500, 3150, and 4000 Hz for calculating the sound absorption coefficient is the frequency band of the voice emitted by the child in the facility such as a nursery school or kindergarten, and is the frequency band of the voice of the child. A high-pitched voice such as a golden voice and a typical one in a frequency band that can be heard with high sensitivity are selected, and are determined by referring to the following documents.
Mari Ueda, 4 others, "Analysis of Acoustic Features of Children's Screaming", Proceedings of the Acoustical Society of Japan, September 2016, 789-790
Supervised by Yasuo Tokita, "Sound Environment and Noise Control Technology", Volume 1, Basic Technology, p111

In other words, the sound absorbing panel 1 using the sound absorbing means 3 of Examples 1 to 21 has frequencies that can be perceived as noise by the surrounding residents, such as high-pitched voices, among the voices emitted by children in facilities such as nursery schools and kindergartens. It can effectively absorb sound from the band.

The sound absorbing panel 1 according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, the sound absorbing panel 1 is provided with a through hole h provided in the front plate 23 for passing sound from a sound source in a circular small hole shape, but the present invention is not limited to this, and a through hole or slit other than the circular hole or slit is provided. It may be formed in another shape such as a long hole shape.

Further, the sound absorbing panel 1 has only one sound absorbing means 3 installed behind the front plate 23, but the present invention is not limited to this, and a plurality of sound absorbing means 3 may be arranged vertically or horizontally. ..

1 Sound absorbing panel 2 Main body 21 Vertical frame 22 Horizontal frame 23 Front plate 24 Sound insulating plate 3 Sound absorbing means 31 Protective material 32 First sound absorbing material 33 Second sound absorbing material 34 Resistive material F Frame

Claims (3)

A sound absorbing panel having a front plate having a through hole and arranged on the sound source side, a sound insulating plate arranged behind the front plate, and a sound absorbing means arranged between the sound insulating plate and the front plate. And
In the sound absorbing means, a protective material, a first sound absorbing material, a resistance material and a second sound absorbing material are arranged in order from the sound source side.
The protective material, the first sound absorbing material, the resistance material and the second sound absorbing material are all breathable.
The resistance material is arranged in a range of 3 mm from the center of the sound absorbing means in the front-rear direction.
A sound absorbing panel characterized in that the flow resistance of the resistance material is larger than the flow resistance of the first sound absorbing material and the second sound absorbing material. The sound absorbing panel according to claim 1, wherein the first sound absorbing material and the second sound absorbing material have the same material, the same thickness, and the same ventilation performance. A sound absorbing panel having a front plate having a through hole and arranged on the sound source side, a sound insulating plate arranged behind the front plate, and a sound absorbing means arranged between the sound insulating plate and the front plate. And
In the sound absorbing means, a protective material, a first sound absorbing material, a resistance material and a second sound absorbing material are arranged in order from the sound source side.
The protective material, the first sound absorbing material, the resistance material and the second sound absorbing material are all breathable.
The resistance material is located at the center of the sound absorbing means in the front-rear direction.
The first sound absorbing material and the second sound absorbing material have the same material, the same thickness, and the same ventilation performance.
A sound absorbing panel characterized in that the flow resistance of the resistance material is larger than the flow resistance of the first sound absorbing material and the second sound absorbing material.

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