JP2817997B2 - Sound absorber and sound absorbing component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

TECHNICAL FIELD The present invention relates to a sound absorbing body and a sound absorbing structure applied to an elevated road, a rail bottom girder or a trench, a semi-underground road side wall, and the like.

[0002]

[Prior art]

A wide variety of soundproofing walls are installed along a highway or a railway for the purpose of absorbing noise generated by a car or a train. These soundproofing walls are for absorbing sound and shielding sound, and usually include a sound absorbing portion having a sound absorbing function and a sound insulating portion for holding the sound absorbing portion and simultaneously blocking transmission of sound.

For example, as shown in a front view of FIG. 12 and a sectional view taken along the line ZZ of FIG. 13, a soundproof wall (11) has a metal front plate (12) formed with a number of slits and a metal on the back side. Back plate (1
3) and a sound absorbing material (14) provided between the front plate (12) and the back plate (13). A fiber material such as glass wool is used for the sound absorbing material (14), and the sound absorbing material (14) is wrapped with a thin synthetic resin film for protection.

[0004] In the above soundproof wall (11), the generated sound is transmitted to the front panel (12).
The sound that has been absorbed by the sound absorbing material (14) through the slits provided therein and passed through the sound absorbing material (14) is shielded by the back plate (13) and does not leak to the outside. It is well known that a porous material such as ceramic or sintered metal is used as the sound absorbing material (14) in addition to the above-mentioned fiber-based material. When the sound absorbing material (14) has a soundproof wall (11) structure made of a porous material, the generated sound is absorbed by the sound absorbing material (14) made of the porous material serving as the front plate (12), and the transmitted sound is reduced. Sound insulation by the metal back plate (13).

As described above, the soundproof wall (11) of the above configuration example is often installed and used along a highway or a railway, but recently, an elevated road, a railroad girder or a digging, a side wall of a semi-underground road. And so on. Most of the sound absorbing materials applied to these soundproof walls have a flat plate structure.

[0006]

[Problems to be solved by the invention]

Conventional sound-absorbing structures applied to highways and railroads, elevated roads, railroad bottom girders and trenches, semi-underground side walls, etc. are metal front plates with a number of slits formed as a soundproof wall (11) structure. (12) and back metal back plate (13)
And a sound absorbing material (14) interposed between the front plate (12) and the rear plate (13). The overall structure of the sound absorbing structure or the sound absorbing material (14) is a flat plate. It is configured in a shape.

[0007] For this reason, not only is the sound absorbing power not less than 1 and a sound absorbing coefficient of 1.0 cannot be obtained, but it is difficult to select a sound absorbing area with respect to the area of the sound absorbing component at an arbitrary magnification. That is, since the sound absorbing power of the conventional flat-type sound absorbing structure is determined by the performance of the sound absorbing material and the wall area of the sound absorbing structure, the limit is sound absorption coefficient × wall area. Therefore, it is necessary to increase the wall area as much as possible to select a sound-absorbing material having high sound-absorbing performance in order to increase the sound absorbing power to 1 or more as this kind of sound absorbing structure.

From this point of view, when examining the sound absorbing performance of the conventional flat-plate-shaped sound absorbing structure, the cross-sectional area of a single body is limited because the sound absorbing material or the sound absorbing structure has a flat structure. When the sound absorbing material was attached to the soundproof wall, it was impossible to increase the area of the soundproof wall. The sound absorption coefficient is deflected by the incident angle of the sound wave to the sound absorbing material, and the desired sound absorbing power cannot be obtained. And so on.

The present invention has been made in view of the above-mentioned point of view, and has an object to obtain a sound absorbing power of 1 or more and a sound absorbing coefficient of 1.0,
Another object of the present invention is to provide a sound absorbing body and a sound absorbing structure capable of selecting a sound absorbing area with respect to a sound absorbing structure area at an arbitrary magnification.

[0010]

[Means for Solving the Problems]

According to the present invention, as a means for achieving the above-mentioned object, a sound absorbing plate made of foamed aluminum having a communication hole is formed in a cylindrical or spherical hollow structure, and a sound absorbing body is formed on a shaft portion in the sound absorbing plate. The core member for supporting the sound absorbing plate is arranged, and a hanger plate for arranging the sound absorbing plate in a three-dimensional arrangement in a staggered arrangement is attached to an end of the sound absorbing plate and the core member, and a sound absorbing structure. As a body, by arranging a plurality of the above sound absorbers three-dimensionally in a staggered arrangement at a predetermined position in front of a sound insulating wall made of fiber reinforced concrete or the like,
This adopts a configuration formed so as to obtain a sound absorbing power of 1 or more and a sound absorbing coefficient of 1.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is a sound absorbing body and a sound absorbing structure as described above.The sound absorbing body has a steel pipe having a diameter of 50 to 100 mm as a core material, and a cylindrical shape having a thickness of about 9 mm so that a predetermined air layer exists in the core material. The sound absorbing material is arranged as a basic structure, but the sound absorbing body is made cylindrical, so that the oblique incidence sound absorbing coefficient has less drop than the flat type sound absorbing body even when the incident angle increases. . That is, as shown in the graph of FIG. 8 showing the result of an experiment on the dependence of the oblique incidence sound absorption coefficient on the incident angle, the incident angle θ between the conventional flat-plate-type sound absorber and the cylindrical-type sound absorber of the present invention is different.
There is almost no difference in the oblique incidence sound absorption coefficient in the vicinity of about 30 degrees, but when the incident angle θ becomes about 30 degrees or more, the oblique incidence sound absorption coefficient of the flat-plate type sound absorber gradually decreases, and Incident angle θ
It was found that the oblique incidence sound absorption coefficient dropped extremely when the angle exceeded 60 degrees.

In the present invention, the configuration of the sound absorber is made cylindrical based on the above experimental results. Next, the sound absorbing component adopts a configuration in which a plurality of cylindrical sound absorbing members are attached to predetermined positions of the sound insulating wall. As an example of the arrangement configuration, a plurality of sound absorbing members are arranged at the same pitch in the same plane. This is based on the results of an experiment conducted on a configuration example in which the above-described configuration example and a configuration example in which a plurality of sound absorbers are arranged three-dimensionally. In other words, a configuration example in which a plurality of sound absorbers are mounted on the sound insulation wall at equal intervals in the same plane will be described. The arrangement pitch D of each sound absorber (the pitch here is the difference between the diameter of the sound absorber and the interval between the sound absorbers). It has been found from experimental results that the smaller the value of the sum is, the higher the sound absorbing power is.

This is because the arrangement pitch D of each of the above sound absorbers is 300 mm, 400 m
As shown in the graph of FIG. 9 showing the experimental results of measuring the sound absorbing power by the reverberation chamber method when m and 600 mm, the overall tendency that appears with the change of the frequency is common at any arrangement pitch D. However, the sound absorbing power differs depending on the value of the arrangement pitch D of the sound absorbers. That is, as described above, it can be seen that the sound absorbing power increases as the arrangement pitch D decreases.

The vertical axis in the graph of FIG. 9 indicates sound absorption power / wall unit area (m ² ), and the horizontal axis indicates frequency (Hz). Further, the graph shown in FIG. 10 is based on the reverberation chamber method in which a plurality of sound absorbers are arranged in a staggered arrangement on the sound insulating wall as shown in the figure, and the arrangement pitch D is 300 mm, 400 mm, and 600 mm. FIG. 8 is a graph showing the experimental results of measuring the sound absorbing power. In all the arrangement pitches D as in the above case, the overall tendency that appears with the change in the frequency is common. The sound absorbing power varies depending on the value of the body arrangement pitch D. That is, by reducing the arrangement pitch D, the ratio of sound absorbing power / wall unit area (m ² ) can be increased, and the sound absorbing power can be arbitrarily increased to one or more.

[0015] The graph of Fig. 11 shows a structure in which a rubber sphere is used as a core material as a sound absorbing body, and the sound absorbing material is wrapped in a spherical shape around its peripheral surface. The arrangement pitch D300mm, 400mm, is a graph showing the experimental results of measuring the sound absorption by the reverberation chamber method in the case of 600mm example, even in any case as described above,
The general tendency that appears with changes in frequency is common.
However, the sound absorbing power differs depending on the value of the arrangement pitch D of the sound absorbing bodies. That is, the sound absorbing power is increased by increasing the ratio of sound absorbing power / wall unit area (m ² ).

[0016]

【Example】

Hereinafter, embodiments of a sound absorbing body and a sound absorbing structure according to the present invention will be described in detail with reference to FIGS. 1 to 7. The basic structure of the sound absorbing body will be described with reference to cross-sectional views of FIGS. 1A and 1B. A plurality of partitioning machines (2) are arranged in a longitudinal direction on a core material (1) of a steel pipe having a diameter of 50 to 100 mm. (2)
A cylindrical sound-absorbing material (3) made of aluminum foam having a communication hole is formed and arranged with an air layer L, and the end is sealed with a flange (4). is there.

FIG. 2 shows a modified example of the sound absorbing body of the present invention. The core material (1) having the above-mentioned basic structure is formed into a spherical shape with synthetic rubber or another synthetic resin, and the spherical core material (1) is formed. ) Is a configuration example in which a spherical sound absorbing material (3) made of foamed aluminum having a communication hole is enclosed by forming an air layer L and covering the surface with a sound absorbing cloth (3a) such as gauze or felt. is there. In addition, reference numeral (5) denotes a hanging tool connected to the spherical core material (1).

Although the configuration example of the sound absorbing body of the present invention is as described above, a case where this is configured as a sound absorbing structure will be described with reference to FIGS. 3 to 7. 3A and 3B are application examples in which a sound absorbing structure is attached to an underpass of an elevated road, a railroad bottom girder, or a side wall of a trench, and FIG. 3) A metal sound insulation wall X is attached to B), and a plurality of sound absorbers Y ...
Are arranged at equal pitch intervals toward the road surface.

A detailed mounting structure for applying the sound absorbers Y to the elevated road shown in FIG. 3A is shown in FIG. Hanger plate (1
2) is attached, and the end of the sound absorbing body Y is inserted and hung. The means for suspending the sound absorbers Y is as described above. However, since the length of the sound absorbers Y is molded to a size of about 3 m, it is necessary to arrange the sound absorbers Y over the entire area of the lower surface of the beam (10). Need to be connected in the same direction.

In this embodiment, the structure shown in FIGS. 5A and 5B is used as a connection structure between the sound absorbers Y alone. That is, in the structural example of FIG. 5A, a helical tube (1a) is applied to the sound absorbing body Y as the core material (1), and the sound absorbing material (3) is used.
An air layer L is formed between them, and the action of improving the tightening force with a hanger plate (12) described later is performed. When connecting the sound absorbing body Y, as shown in the figure, a hanger plate (1) having a through hole (121) formed in the shaft core and a flange portion (122) formed in contact with the inner surface of the spiral tube (1a) is formed.
2) is arranged at the end of the attached sound absorbing body Y, and another sound absorbing body Y is inserted into the flange portion (122) of the hanger plate (12) so that the spiral tube (1a) is circumscribed. Joined to the end of the sound absorber Y.

Thereafter, a rubber band (9) for tightening and waterproofing is provided on the outer peripheral surface of the joint of the sound absorbers Y... And the upper portion is tightened with bolts. When the joining of the sound absorbers A is completed as described above,
The tie rods (7) are inserted into the through holes (121) of the hanger plate (12) and tightened to make the sound absorbers A more firmly joined together. Reference numeral (8) is a blind rivet.

FIGS. 6A and 6B show an example of a structure in which two L-shaped members (1b) are applied as a core member (1) as a set.
Both parts are combined and integrated with bolts so as to form a swastika shape as a configuration in which the sheets are joined together, and their ends are fastened to the sound absorbing material (3) with bolts. The hanger plate (12) is disposed at the end of the attached sound absorber Y in the same manner as in the above-described embodiment, and the core material is attached to the flange portion (122) of the hanger plate (12). Another sound absorber Y is inserted so that (1) is circumscribed, and is joined to the end of the attached sound absorber Y. Thereafter, a rubber band (9) for tightening and waterproofing is provided on the outer peripheral surface of the joint of the sound absorbers Y...

When the joining of the sound absorbers Y is completed as described above,
The tie rods (7) are inserted into the through holes (121) of the hanger plate (12) and tightened to make the sound absorbers Y more firmly joined together. 7A and 7B, four tie rods (7) are arranged as a core material (1) as shown in the figure, and these are respectively passed through through holes (121) of the hanger plate (12). Let them be tight.

[0024]

【The invention's effect】

As described above, the sound absorbing body and the sound absorbing structure of the present invention have a sound absorbing plate made of a foamed aluminum having a communication hole as a sound absorbing body formed in a cylindrical or spherical hollow structure, and the sound absorbing plate is provided on a shaft core in the sound absorbing slope. A core member for supporting the plate is arranged, and a hanger plate for arranging the sound absorbing plates in a three-dimensional arrangement in a staggered arrangement is attached to an end of the sound absorbing plate and the core member, and as a sound absorbing structure. By arranging a plurality of the sound absorbers three-dimensionally in a staggered arrangement at a predetermined position in front of sound insulation made of fiber reinforced concrete or the like,
Since the sound absorbing body or the sound absorbing structure has a cylindrical or spherical structure because the sound absorbing body or the sound absorbing structure is formed to have a sound absorbing power of 1 or more and a sound absorbing coefficient of 1, the cross-sectional area of the single body is flat. When the sound absorbing body is attached to the sound insulating wall, the sound absorbing area can be selected at an arbitrary magnification with respect to the area of the sound insulating wall.

Further, there is no problem that the sound absorption coefficient is deflected by the incident angle of the sound wave to the sound absorbing body, and the sound absorption power is 1 or more, and a sound absorption coefficient of 1.0 is obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are longitudinal sectional views showing one embodiment of a sound absorbing body of the present invention.

FIG. 2 is a longitudinal sectional view showing a modified example of the sound absorbing body of the present invention.

FIGS. 3A and 3B are longitudinal sectional views showing one construction example of the sound absorbing structure of the present invention.

FIG. 4 is an enlarged sectional view of a main part showing a joined portion of the sound absorbing component.

FIGS. 5A and 5B are enlarged cross-sectional views of main parts showing a joint portion of the sound absorbing structure.

FIGS. 6A and 6B are enlarged cross-sectional views of essential parts showing a modification of the joining portion of the sound absorbing structure.

FIGS. 7A and 7B are enlarged cross-sectional views of a main part showing a modified example of a joint portion of the sound absorbing structure.

FIG. 8 is a graph showing the results of a comparison experiment of the dependency of the sound absorbing body of the present invention on the incident angle of the conventional sound absorbing body.

FIG. 9 is a graph showing the results of a reverberation room absorption sound measurement when the sound absorbing structure of the present invention is used.

FIG. 10 is a graph showing the results of measurement of the sound absorption in a reverberation room when the sound absorbing structure of the present invention is used.

FIG. 11 is a graph showing the results of a reverberation room absorption sound measurement when the sound absorbing structure of the present invention is used.

FIG. 12 is a front view showing a configuration example of a conventional flat-type sound absorber.

FIG. 13 is a sectional view taken along the line ZZ in FIG. 12;

[Explanation of symbols]

 (1) Core material (2) Partition board of sound absorbing component (3) Sound absorbing material (4) Flange (5) Sound absorber support (6) Road (7) … Tie rods (9)… Rubber bands (10)… Girders on elevated roads (12)… Hanger plates

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mikio Kato 4-2-18 Ina, Minoh-shi, Osaka (72) Inventor Masaru Uenaka 7-1-4 Higashihagoromo, Takaishi-shi, Osaka (72) Inventor Taizo Tateishi Osaka 2-3 D-2-102, Shinsenri-nishi-cho, Toyonaka-shi, Tofu-shi 10-1 Inside Shinko Wire Industry Co., Ltd. (72) Inventor Kyomin Kasai 10-1 Nakahamacho, Amagasaki City, Hyogo Prefecture Inside Kobe Steel Wire Industry Co., Ltd. (56) References JP-A-1-315506 (JP, A) Japanese Utility Model Application Sho 63-65714 (JP, U) Japanese Patent Publication No. 60-38490 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) E01F 8/00

Claims (2)

(57) [Claims] 1. A sound absorbing plate made of aluminum foam having a communication hole is formed in a cylindrical or spherical hollow structure.
A core member for supporting the sound absorbing plate is disposed on a shaft core portion in the sound absorbing plate, and a hanger plate for arranging the sound absorbing plate three-dimensionally in a staggered arrangement is provided at an end of the sound absorbing plate and the core member. A sound absorber characterized by being attached. 2. A sound absorbing plate made of foamed aluminum having a communication hole is formed in a cylindrical or spherical hollow structure.
A core member for supporting the sound absorbing plate is disposed on a shaft core portion in the sound absorbing plate, and a hanger plate for arranging the sound absorbing plate three-dimensionally in a staggered arrangement is provided at an end of the sound absorbing plate and the core member. A plurality of sound absorbers to be attached are three-dimensionally arranged in a staggered arrangement at predetermined positions in front of a sound insulation wall made of fiber-reinforced concrete or the like, so that a sound absorption of 1 or more and a sound absorption coefficient of 1 are obtained. A sound absorbing structure characterized by the above.