JPH093833A - Sound-absorptive structure - Google Patents

Abstract

PURPOSE: To increase the sound-absorptive capacity, by parallelly arranging a plurality of sound-absorptive units made of a porous sound-absorptive material and a hollow space formed at the rear part thereof through sound-absorptive holes to define a soundabsorptive part and forming a resonance chamber between the soundabsorptive unit and a sound-insulating member provided at the rear side of the sound-absorptive part and further, connecting the resonance chamber to the sound-absorptive holes. CONSTITUTION: A sound-absorptive unit 1 is constituted of a porous sound-absorptive material 11 and a hollow space 12 formed at the rear side thereof. A plurality of these sound-absorptive units 1 are parallelly arranged so at to form sound-absorptive holes 2 between adjacent sound-absorptive units to define a sound-absorptive part A. A resonance chamber B is formed between the sound absorptive part A and a sound-insulating member 3 provided at the rear side of the sound-absorptive part A and connected to the sound-absorptive holes 2. Accordingly, sounds in the lower frequency zone than the resonance chamber B are attenuated and absorbed and sounds in the middle or higher frequency zone than that are absorbed by the porous sound- absorptive material 11 and the hollow space 12. In this way, the sound-absorptive capacity can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower portion of an elevated structure such as a railway, an elevated road, a bridge or an elevated road, a side surface of a trench or a semi-underground road, a highway, or a wall surface of a general building or a ceiling surface of an underpass. The present invention relates to a sound absorbing structure that is attached to a vehicle.

[0002]

2. Description of the Related Art Conventionally, as this type of sound absorbing structure, as shown in FIGS. 7 and 8, a sound absorbing structure consisting of a sound absorbing material and a space formed behind the sound absorbing material is known.

[0003]

However, in the conventional sound absorbing structure as described above, for example, glass wool in FIG. 7 and aluminum fiber board in FIG. 8 are used as the sound absorbing material.
As a result of measuring the sound absorption performance by the normal incidence method, FIG. 9 and FIG.
There is a drawback that the sound absorption performance in the low frequency range is inferior as 0.

Therefore, the present invention solves the above problems,
An object of the present invention is to provide a sound absorbing structure having an excellent sound absorbing effect.

[0005]

In order to achieve the above object, the present invention has the following arrangement. That is, in the sound absorbing structure according to the present invention, a plurality of sound absorbing units each including a porous sound absorbing material and a space portion formed behind the porous sound absorbing material are arranged in parallel with each other by forming sound absorbing holes to form a sound absorbing portion. A resonance chamber is formed between the resonance chamber and the sound insulation member, and the resonance chamber and the sound absorbing hole are communicated with each other.

[0006]

According to the sound absorbing structure of the present invention, the sound absorbing effect by the sound absorbing unit including the porous sound absorbing material and the space portion formed behind it and the sound insulation member provided behind the sound absorbing unit are provided. Excellent sound absorption performance is exhibited by the synergistic effect with the damping effect of the resonance chamber formed in the. That is, the sound in the low frequency range is attenuated and absorbed in the resonance chamber, and the sound in the middle and high frequency range is absorbed by the porous sound absorbing material and the space, so that a wide range of noise from low to medium and high frequency range is received The sound absorbing effect is exhibited.

[0007]

Embodiments of the present invention will now be specifically described with reference to the drawings. First, FIG. 1 is a cross-sectional view showing an embodiment of the sound absorbing structure of the present invention, in which 1 is a porous sound absorbing material 1.
1 and a space 12 formed behind a porous sound absorbing material 11 is a sound absorbing unit. More specifically, the sound absorbing unit 1 comprises a front wall 13, a rear wall 14, left and right side walls 15, a top plate 16 and a bottom plate 17, and the front wall 13 has a large number of small holes 1
8, a porous sound absorbing material 11 made of glass wool is added inside the front wall 13, and a space 12 is formed behind the porous sound absorbing material 11.

Thus, a plurality of the sound absorbing units 1 are arranged in parallel so that the sound absorbing holes 2 are formed between the adjacent sound absorbing units 1, 1 to form the sound absorbing portion A. Behind the sound absorbing portion A, a resonance chamber B communicating with the sound absorbing hole 2 is partitioned by a sound insulating member 3 such as a metal plate. The sound absorbing hole 2 may be curved as shown in FIG. 1, or may be linear, oblique, or curved.

The resonance chamber B is formed behind the sound absorbing portion A, and in the case of FIG. 1, the resonance chamber B is formed integrally with the sound absorbing portion A.

The embodiment shown in FIG. 2 has a front wall 13 and a porous sound absorbing material 1.
1 is the same as the embodiment of FIG. 1 except that 1 and 1 are shared by the aluminum fiber board. The porous sound absorbing material 11 may be made of glass wool, aluminum fiber board, rock wool or other fiber material, polyurethane foam or other plastic foam material, or aluminum or concrete foam material. When glass wool or rock wool is used for the porous sound absorbing material 11, it may be covered with a fluororesin film or the like in order to prevent deterioration of the adhesive.

FIG. 3 is a partially cutaway perspective view showing another embodiment of the present invention. In this embodiment, the porous sound absorbing material 11 is made of aluminum fiber board in common with the front wall 13. Also,
The sound absorbing hole 2 is used in combination with one having an edge protruding toward the resonance chamber B, one having no protruding edge, and one having a bent edge. Further, the sound absorbing unit 1 also has various shapes. Further, the shape of the resonance chamber B is also variously different, such as a portion where a plurality of sound absorbing holes 2 are communicated and a portion where a single sound absorbing hole 2 is communicated. As described above, it is preferable that a plurality of resonance chambers B having different shapes and sizes are combined to absorb noise in various sound ranges.

FIG. 4 is a sectional view showing still another embodiment of the present invention. In the case of this embodiment, the sound absorbing section A is provided on the back side of the elevated road, the back side of the elevated road is the sound insulation member 3, and the resonance chamber B is provided between the sound absorbing section A and the back side of the elevated road. In the case of FIG. 4, a side wall 15 made of a decorative plate is provided between the back end of the elevated road and the end of the sound absorbing part A, and the resonance chamber B is partitioned by the decorative plate. Also in this case, it is preferable to change the size and shape of the sound absorbing section A and the resonance chamber B variously because the sound absorbing performance is improved.

[0013]

According to the sound absorbing structure of the present invention, a plurality of sound absorbing units, each of which is composed of a porous sound absorbing material and a space formed behind the porous sound absorbing material, are arranged in parallel with each other by forming sound absorbing holes to form a sound absorbing portion. Since the resonance chamber is formed between the sound absorbing member provided behind the sound absorbing portion, the sound absorbing unit including the porous sound absorbing material and the space formed behind the sound absorbing unit produces sound in the middle and high frequency range. The sound is absorbed and the sound in the low frequency range is attenuated and absorbed in the resonance chamber, and as a whole, the sound absorbing effect is exhibited for a wide range of noises from the low frequency range to the mid-high frequency range.

The sound absorbing structure according to the present invention comprises a front wall, a rear wall, left and right side walls, a top plate and a bottom plate. The front wall is provided with a large number of small holes, and a porous sound absorbing material is attached to the inside thereof. A sound absorbing unit is formed by forming a space behind the sound absorbing material, and a plurality of sound absorbing units are arranged in parallel by forming sound absorbing holes to form a sound absorbing unit, and a resonance chamber is formed behind the sound absorbing unit. When the sound absorbing hole and the sound absorbing hole are communicated with each other, the structure becomes an integral structure, and like the conventional sound absorbing structure, it can be easily installed along a road or a railway.

Furthermore, when the resonance chamber of the sound absorbing structure is composed of a plurality of resonance chambers having different sizes and shapes, it is possible to absorb noise in various sound ranges.

Furthermore, when the sound insulating member of the sound absorbing structure is the wall surface of the existing structure, the sound insulating member can be omitted, the sound absorbing structure is not bulky, and the cost is low, which is preferable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example in which glass wool is used as a porous sound absorbing material of a sound absorbing structure of the present invention.

FIG. 2 is a cross-sectional view showing an example in which an aluminum fiber board is used as a porous sound absorbing material of the sound absorbing structure of the present invention.

FIG. 3 is a partially cutaway perspective view showing another embodiment of the sound absorbing structure of the present invention.

FIG. 4 is a sectional view showing still another embodiment of the sound absorbing structure of the present invention.

FIG. 5 is a graph showing the results of measuring the sound absorbing performance by the normal incidence method of an example in which glass wool is used as the porous sound absorbing material of the sound absorbing structure of the present invention.

FIG. 6 is a graph showing the results of measuring the sound absorbing performance by the normal incidence method of an example in which an aluminum fiber plate is used as the porous sound absorbing material of the sound absorbing structure of the present invention.

FIG. 7 is a cross-sectional view of a conventional sound absorbing structure using glass wool as a porous sound absorbing material.

FIG. 8 is a sectional view of a conventional sound absorbing structure using an aluminum fiber board as a porous sound absorbing material.

FIG. 9 is a graph showing the results of measuring the sound absorbing performance of a conventional sound absorbing structure using glass wool as a porous sound absorbing material by the vertical incidence method.

FIG. 10 is a graph showing the results of measuring the sound absorbing performance of a conventional sound absorbing structure using an aluminum fiber plate as a porous sound absorbing material by the vertical incidence method.

[Explanation of symbols]

 A sound absorbing part B resonance chamber 1 sound absorbing unit 11 porous sound absorbing material 12 space part 13 front wall 14 rear wall 15 side wall 16 top plate 17 bottom plate 18 small hole 2 sound absorbing hole 3 sound insulating member

Claims (5)

[Claims] 1. A sound absorbing unit comprising a porous sound absorbing material and a space formed behind the sound absorbing unit, which are arranged in parallel with each other with a sound absorbing hole formed therein to form a sound absorbing unit, and a sound insulating unit provided behind the sound absorbing unit. A sound absorbing structure in which a resonance chamber is formed between the member and the resonance chamber communicates with the sound absorbing hole. 2. The sound absorbing structure comprises a front wall, a rear wall, left and right side walls, a top plate and a bottom plate. A sound absorbing unit is formed by forming a space behind the sound absorbing material, and a plurality of sound absorbing units are arranged in parallel by forming sound absorbing holes to form a sound absorbing unit, and a resonance chamber is formed behind the sound absorbing unit. The resonance chamber and the sound absorbing hole are communicated with each other.
The sound absorbing structure described. 3. The sound absorbing structure according to claim 1, comprising a plurality of resonance chambers provided behind the sound absorbing portion. 4. The sound absorbing structure according to claim 3, wherein the resonance chamber is composed of a plurality of different sizes. 5. The sound absorbing structure according to claim 1, 2, 3 or 4, wherein the sound insulating member provided behind the sound absorbing portion is a wall surface of an existing structure.