JP2859578B2 - Sound wave phase change device and sound barrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound wave phase changing device provided around a sound source or in a propagation path for advancing or delaying a sound wave phase, and a soundproof wall using the sound wave phase changing device.

[0002]

FIG. 23 shows, for example, Japanese Patent Publication No. 51-46969.
It is an explanatory view showing a conventional soundproof wall shown in the official gazette. In the figure, a sound insulating wall 1 has a sound absorbing material 2 along its upper end.
Is attached. There are various types of shapes and mounting structures of the sound absorbing material 2 as shown in FIGS.

FIG. 24 shows, for example, Japanese Patent Application Laid-Open No. 52-915.
It is explanatory drawing which shows the other example of the conventional soundproof wall shown by No. 14. In the figure, a non-transmissive body 3 is attached to a sound insulating wall 1 along an upper end thereof. The non-transmissive body 3
It has a structure that prevents transmission of sound waves. There are various types of shapes and mounting structures of the non-transmissive body 3 as shown in FIGS.

FIG. 25 is an explanatory view showing the operation of the soundproof wall shown in FIG. The sound wave 5 a radiated from the sound source 4 and directly colliding with the sound absorbing material 2 and the sound wave 5 b reflected by the sound insulating wall 1 and colliding with the sound absorbing material 2 are absorbed by the sound absorbing material 2. Therefore, only the sound wave 5c diffracting above the sound absorbing material 2 is radiated outward beyond the sound insulating wall, and the sound passing through the sound insulating wall is reduced.

FIG. 26 is an explanatory view showing the operation of the soundproof wall of FIG. The sound wave 5d directly colliding with the non-transmissive body 3 and the sound wave 5e reflected by the sound insulating wall 1 and colliding with the non-transmissive body 3 are as follows.
Each is reflected by the non-transmissive body 3. These sound waves 5d,
The phase of 5e is slightly shifted from the phase of the sound wave 5c diffracting the non-transmitting member 3 due to the difference in the path length. Therefore, the sound waves 5d and 5e and the sound wave 5c interfere with each other, thereby weakening both sound waves and reducing sound passing through the soundproof wall.

[0006]

However, in the conventional soundproof wall using the sound absorbing material 2 as described above, the sound wave 5c diffracted by the sound absorbing material 2 cannot be reduced.
Further, in the soundproof wall using the non-transmissive body 3, there is only a phase shift due to a difference in the path length due to the shape, so that the sound reduction effect due to mutual interference is small.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can significantly shift the phase of an incident sound wave, thereby enhancing the sound reduction effect due to mutual interference of sound waves. It is an object of the present invention to obtain a sound wave phase changing device and a soundproofing wall which can be used.

[0008]

According to a first aspect of the present invention, there is provided a sound wave phase changing apparatus comprising a combination of a porous member made of a porous material and a plurality of sound insulation plates. A sound insulating plate assembly is provided on the back of the member, which forms a plurality of independent spaces having different volumes.

According to a second aspect of the present invention, there is provided a sound wave phase changing apparatus using a porous member made of a porous material obtained by partially welding a large number of plastic particles.

According to a third aspect of the present invention, in the sound wave phase changing device, the sound insulating plate and the porous member exposed to the outside are joined to form a corner.

According to a fourth aspect of the present invention, there is provided a sound wave phase changing device using a plate-like porous member and changing its thickness.

In the sound wave phase changing device according to a fifth aspect of the present invention, the thickness of the porous member is changed by changing the number of layers.

According to a sixth aspect of the present invention, there is provided a sound wave phase changing apparatus using a plate-shaped porous member having a cross-sectional shape bent so as to increase an area on which a sound wave is incident.

According to a seventh aspect of the present invention, in the sound wave phase changing device, the size of the cross-sectional shape of the porous member is changed along the longitudinal direction so that the area of the porous member on which the sound wave is incident increases. It has been changed.

In the sound wave phase changing device according to the present invention, the sound insulating plate constituting the bottom of the space is inclined with respect to the horizontal direction, and the porous member is connected to the lower end. Is what it is.

The sound wave phase changing device according to the ninth aspect of the present invention uses a material that transmits light as a material of the porous member and the sound insulating plate assembly.

According to a tenth aspect of the present invention, a soundproof wall is provided along a soundproof panel erected near a sound source, a porous member made of a porous material, and along an upper end of the soundproof panel. A sound wave phase changing device comprising a combination of a plurality of sound insulation plates, and having a sound insulation plate assembly that supports the porous member and forms a plurality of independent spaces with different volumes on the back of the porous member. Things.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a sectional view of a main part of a soundproof wall having a sound wave phase changing device according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the operation of the soundproof wall in FIG.

In FIG. 1, a soundproof panel 11 is provided upright on a side of a road through which a sound source (or noise source) 4 such as an automobile passes. At the upper end of the soundproof panel 11, a first sound insulating plate 1 is provided.
2 is fixed vertically. A plurality of second sound insulating plates 13 are horizontally fixed to both side surfaces of the first sound insulating plate 12. The first and second sound insulation plates 12 and 13 are made of, for example, an iron plate or a plastic plate. The first and second sound insulation plates 12 and 13 constitute a sound insulation plate assembly 14.

A cylindrical porous member 15 is provided on the outer periphery of the sound insulating plate assembly 14. The porous member 15
The soundproof panel 11 extends along the longitudinal direction. Also,
At the back of the porous member 15, independent spaces 16 having different volumes are formed. The sound wave phase changing device 17 according to the first embodiment has a porous member 15 and a sound insulating plate assembly 14 also serving as a reinforcing member. In addition, the sound wave phase changing device 17 and the soundproof panel 11 allow the first embodiment to be used.
Soundproof wall is configured.

As the material of the porous member 15, plastic, ceramic, foamed metal or the like can be used.
For example, when using plastic, a method of manufacturing the porous member 15 by partially heating and welding plastic particles can be applied. Such a method is disclosed in, for example,
No. 89333. Further, as the plastic material, for example, polypropylene resin, acrylic resin, vinyl chloride resin, ABS resin, polycarbonate resin, or the like can be used. According to the method of welding the plastic particles, the porous member 15 having a desired shape can be easily molded by a mold.

Next, the operation will be described. In FIG. 2, a sound wave 18 directly incident on a sound wave phase changing device 17,
The sound wave 19 reflected by the soundproof panel 11 and incident on the sound wave phase changing device 17 passes through the porous member 15 and enters the space 16, and the sound insulating plate 12, which forms the wall of the space 16,
It is reflected at 13. Then, the light passes through the porous member 15 and goes out of the sound wave phase changing device 17.

When the sound wave 18 enters the sound wave phase changing device 17 at an incident angle β and exits as a sound wave 18a, the normal acoustic impedance Z of the sound wave phase changing device 17
Is Z = ρa / cos (β) × (Pi + Pr) / (Pi
-Pr). Here, ρa (ρ: density of air, a: sound velocity in air) is the characteristic impedance of air, Pi is the sound pressure of incident sound wave 18, and Pr is the sound pressure of reflected sound wave (sound wave from sound wave phase changing device 17) 18 a It is.

From the above equation, the sound pressure reflectance R of the sound wave phase changing device 17 is given by: R = Pr / Pi = (Zcos (β) −ρ
a) / (Zcos (β) + ρa).
From this equation, the phase difference θ between the incident sound wave 18 and the reflected sound wave 18a is expressed as θ = arg (R).

The porous member 15 in the sound wave phase changing device 17 has an acoustic mass m and an acoustic resistance r as acoustic characteristics, and the space 16 has an acoustic capacitance c as acoustic characteristics.
Therefore, the normal acoustic impedance Z of the sound wave phase changing device 17 is Z = r + j2 when the frequency is f.
πfm + 1 / j2πfc. Where j ² = −1
It is.

As described above, the incident sound wave 18 and the reflected sound wave 1
8a is changed by the normal acoustic impedance Z. Sound wave phase changing device 1 of the first embodiment
According to 7, the normal acoustic impedance Z can be controlled, and the phase difference can be changed.
Specifically, the acoustic mass m and the acoustic resistance r are controlled by the thickness and the porosity of the porous member 15, and the acoustic capacitance c is controlled by the volume of the space 6, thereby obtaining desired phase characteristics. When the above-described plastic particles are used as the material of the porous member 15, the porosity can be easily controlled by the degree of adhesion between the plastic particles.

FIG. 3 shows the frequency f at the sound wave phase changing device 17.
FIG. 7 is a relationship diagram showing an example of a phase difference θ between an incident sound wave 18 and a reflected sound wave 18a with respect to the first sound wave. In the figure, the phase difference θ is 18
0 degrees or -180 degrees indicates that the phase of the incident sound wave 18 is reversed and is reflected as the reflected sound wave 18a. Thus, the phase difference θ is 180 degrees or −1
When the angle is 80 degrees, the reflected sound wave 18a has a phase opposite to that of the sound wave 20 diffracted on the sound wave phase changing device 17, so that the two cancel each other out, and the entire sound wave is greatly attenuated.

As described above, according to the sound wave phase changing device 17 of the first embodiment, the phase of the incident sound wave can be largely shifted, and thus the sound reduction effect due to the mutual interference of the sound waves can be enhanced. In addition, since a plurality of independent spaces 16 having different volumes are present at the back of the porous member 15, a plurality of phase characteristics suitable for different frequencies can be obtained, and a sound wave having a wider frequency can be obtained. The sound reduction effect can be enhanced.

Further, by using a material in which plastic particles are partially welded as the material of the porous member 15, it is possible to easily mold it into any shape and to easily adjust the porosity. It is.

Further, as a material of the sound insulating plate assembly 14 and the porous member 15, for example, a transparent acrylic resin, a vinyl chloride resin, an ABS resin, a polycarbonate resin, or the like can be used.
By using a material that transmits light, it is possible to prevent the surroundings from becoming dark when used as a soundproof wall.

Embodiment 2 Next, FIG. 4 is a sectional view of a main part of a soundproof wall having a sound wave phase changing device according to a second embodiment of the present invention, and FIG. 5 is an explanatory view showing the operation of the soundproof wall in FIG. In the first embodiment, the cross-sectional shape of the sound wave phase changing device 17 is circular. However, in the second embodiment, a plate-shaped sound wave phase changing device 21 having a substantially semicircular cross-sectional shape is used. Further, the lowermost second sound insulating plate 13a exposed to the outside and the porous member 15 form a corner portion (edge portion) 22.
Are formed to form Other configurations are the same as those in the first embodiment.

Next, the operation will be described. The phase of the sound wave 18 that is directly incident on the sound wave phase changing device 21 is shifted as in the first embodiment. Also, soundproof panel 1
The sound wave 23 reflected at 1 and passing through the corner 22 is
The phase is shifted by, for example, 180 degrees due to the phase change effect due to the shape of. Thus, the phase-shifted sound wave 18
a and 23a and the sound wave 20 diffracting above the sound wave phase changing device 21 cancel each other, and the whole sound wave is attenuated.

Such a sound wave phase changing device 21 is smaller in size as compared with the sound wave phase changing device 21 as shown in FIG. In addition, since the corners 22 are provided, a phase change effect due to the shape of the corners 22 can be obtained. Further, since the corners 22 are on both sides of the sound wave phase changing device 21, a sound reduction effect can be obtained regardless of the position of the sound source 4 on either side of the sound wave phase changing device 21.

Embodiment 3 Next, FIG. 6 is a sectional view of a main part of a sound wave phase changing device according to a third embodiment of the present invention. In this example, the cross-sectional shape of the sound wave phase changing device 24 is substantially fan-shaped.

In such an apparatus, the whole can be further miniaturized as compared with the second embodiment. Moreover, a sound reduction effect similar to that of the second embodiment can be obtained for the sound source on the corner 22 side.

Embodiment 4 FIG. Next, FIG. 7 is a sectional view of a main part of a sound wave phase changing device according to a fourth embodiment of the present invention. In the first to third embodiments, the curved porous member 1
5, the sound wave phase changing device 2 according to the fourth embodiment is shown.
In 5, the flat porous member 26 is used.

As described above, by making the porous member 26 flat, the manufacture and assembly can be easily performed. Further, since the corners 22 are provided, the same sound reduction effect as in the third embodiment can be obtained.

Embodiment 5 Next, FIG. 8 is a sectional view of a main part of a sound wave phase changing device according to a fifth embodiment of the present invention. In the above embodiments, one porous member is shown, but in the sound wave phase changing device 27 of this example, a plurality of divided porous members 28 are used. Each porous member 2
A corner 29 is formed at the joint between the sound insulation plate 13 and the sound insulation plate 13.

In such a sound wave phase changing device 27, not only the phase of the sound wave incident on the porous member 28 is shifted, but also the phase is changed by the corners 22 and 29.
A great sound reduction effect is obtained.

Although FIG. 8 shows the porous member 28 in the form of a flat plate, it may have, for example, a polygonal line shape or a wavy cross-sectional shape.

Embodiment 6 FIG. FIG. 9 is a cross-sectional view of a main part of a sound wave phase changing device according to Embodiment 6 of the present invention. The sound wave phase changing device 30 of this example includes a flat porous member 26.
And has a cross-sectional shape that is substantially upside down as shown in FIG.

With the sound wave phase changing device 30 having such a shape, a sound reduction effect substantially similar to that of the third embodiment can be obtained.

Embodiment 7 FIG. 10 and 11 are cross-sectional views of main parts of a sound wave phase changing device according to Embodiment 7 of the present invention. In the figure, a sound insulating plate assembly 31 includes first and second sound insulating plates 12 and 13 and an arc-shaped third sound insulating plate 3.
2 and 2 arranged radially from the third sound insulating plate 32.
And four fourth sound insulation plates 33. The sound wave phase changing device 34 has a sound insulation plate assembly 31 and a porous member 35 having an arc-shaped cross section. The plate-shaped porous member 35 is made of the same material as in each of the above embodiments, but the thickness thereof is changed. In FIG. 11, the thickness of the end opposite to the porous member 35 in FIG. 10 is increased.

Next, the operation will be described. The porous member 35 of the sound wave phase changing device 34 has an acoustic mass m and an acoustic resistance r as acoustic characteristics, and the space 16 has an acoustic capacitance c as acoustic characteristics. Here, by changing the thickness of the porous member 35, the acoustic mass m and the acoustic resistance r can be controlled, and desired phase characteristics can be obtained.

In FIGS. 10 and 11, the porous member 3
Although the thickness of No. 5 changes continuously, it may be changed discontinuously.

Embodiment 8 FIG. 12 and 13 are cross-sectional views of main parts of a sound wave phase changing device according to Embodiment 8 of the present invention. In the sound wave phase changing device 36 of this example, a plate-shaped porous member 15 having a uniform thickness is used, but the overall thickness is changed by laminating the porous members 15. . FIG. 13 shows a laminated example different from FIG. With such a sound wave phase changing device 36, the same effect as in the seventh embodiment can be obtained.

Embodiment 9 FIG. Next, FIG. 14 is a sectional view of a main part of a sound wave phase changing device according to a ninth embodiment of the present invention. In the sound wave phase changing device 37 of this example, porous members 38 and 39 having a curved cross section are used in place of the flat porous member 28 of FIG.

As described above, by bending the cross-sectional shape of the porous members 38 and 39, their substantial surface area, that is, the area where sound waves are incident, is larger than the projected area. Thereby, the apparent acoustic mass m and the acoustic resistance r are reduced, and a phase difference characteristic closer to ± 180 degrees can be obtained. Therefore, a more excellent sound reducing effect can be obtained.

Embodiment 10 FIG. The cross-sectional shape of the porous member is not limited to that shown in FIG.
A porous member 40 having a cross-sectional shape as shown in FIG. 1 may be used. If the surface area is larger than the projected area, the same effect can be obtained.

Embodiment 11 FIG. FIG. 16 is a sectional view of a main part of a sound wave phase changing device according to Embodiment 11 of the present invention. In the sound wave phase changing device 41 of this example, the sound insulating plate constituting the bottom of the space 16, that is, the second sound insulating plate 13 is inclined with respect to the horizontal direction, and a porous member is provided at the lower end. 15 are connected. Other configurations are the same as those of the third embodiment.

In such a sound wave phase changing device 41, the water that has passed through the porous member 15 and entered the space 16 is
And is discharged from the porous member 15 near the corner 22 to the outside. Therefore, when the sound wave phase changing device 41 is applied to a soundproof wall and used outdoors, it is possible to easily take measures against rainwater. The sound reduction effect is the same as in the third embodiment.

Embodiment 12 FIG. FIG. 17 is a sectional view of a main part of a sound wave phase changing device according to a twelfth embodiment of the present invention. In the sound wave phase changing device 42 of this example, a lighting device 43 such as a fluorescent lamp is disposed in the sound insulating plate assembly 31. Further, as a material of the porous member 15 and the sound insulation plate assembly 31, a transparent or translucent acrylic resin, a vinyl chloride resin, an ABS resin, a polycarbonate resin, or the like is used.

In such a sound wave phase changing device 42, the soundproof wall can be used as an illumination device. Also,
A sound reduction effect substantially similar to that of the third embodiment can be obtained.

Embodiment 13 FIG. FIG. 18 is a plan view showing a configuration of a sound wave phase changing device according to Embodiment 13 of the present invention, and has the same cross-sectional shape as FIG. In the sound wave phase changing device 21 of this example, the size of the entire cross section changes along the longitudinal direction so that the area on which sound waves are incident increases.

In such a sound wave phase changing device 21, since the substantial surface area is larger than the projection area,
The apparent sound mass m and the sound resistance r can be reduced, and a phase difference characteristic closer to ± 180 degrees can be obtained.
An even better sound reduction effect is obtained.

In FIG. 18, the planar shape of both sides of the sound wave phase changing device 21 is a polygonal line, but is not limited to this, and may be a wavy line as shown in FIG. Further, regarding the sound wave phase changing device 24 having a cross-sectional shape as shown in FIG. 6, the plane shape of one side may be changed as shown in FIG.

Embodiment 14 FIG. Next, FIG. 21 is a schematic perspective view of a sound wave phase changing apparatus according to Embodiment 14 of the present invention. In each of the above embodiments, the soundproof panel is provided with a separate sound wave phase changing device. However, in this example, the soundproof panel 11 and the sound wave phase changing device 24 are previously manufactured as an integrated body. Have been. This makes it possible to reduce the number of parts and simplify installation by using a common structural material.

FIG. 22 is a schematic perspective view showing another example of FIG. In this example, both ends 11 a in the longitudinal direction of the portion of the soundproof panel 11 are longer than the portion of the sound wave phase changing device 24. Such a soundproof wall is easily provided by erecting columns (not shown) having an H-shaped cross section at intervals and inserting both ends 11a of the soundproof panel 11 into grooves of the columns having the H-shaped cross section. Installed.

When the sound wave phase changing device is integrated with the soundproof panel, the sound wave phase changing device is
Modifications as shown in the above embodiments are possible.

In each of the above embodiments, only the case where the sound wave phase changing device is applied to the soundproof wall has been described. However, the sound wave phase changing device may be installed and used on a structure other than the soundproof panel, such as a building. Is also possible.

[0061]

As described above, according to the first aspect of the present invention, there is provided a sound wave phase changing device, comprising: a porous member made of a porous material;
And a plurality of sound insulation plates are combined, and a sound insulation plate assembly that supports the porous member and forms a plurality of independent spaces having different volumes on the back of the porous member is provided, so that the phase of the incident sound wave is The noise can be greatly shifted, thereby increasing the sound reduction effect due to the mutual interference of sound waves.

Since the sound wave phase changing device according to the second aspect of the present invention uses a porous member made of a porous material obtained by partially welding a large number of plastic particles, the porous member can be formed into any shape. The molding can be easily performed, and the porosity of the porous member can be easily adjusted.

According to the third aspect of the present invention, since the sound insulating plate and the porous member that are exposed to the outside are joined so as to form a corner, the porous member and the space are separated from each other. In addition to the phase change caused by the above, the phase can be changed by the corner, and the sound reduction effect can be enhanced.

The sound wave phase changing device according to the fourth aspect of the present invention uses a plate-shaped porous member and changes the thickness thereof, so that the acoustic mass and the acoustic resistance can be controlled, and the desired sound mass can be controlled. Phase characteristics can be obtained.

In the sound wave phase changing device according to the fifth aspect of the present invention, since the thickness of the porous member is changed by changing the number of layers, the acoustic mass and the acoustic resistance can be easily controlled.

The sound wave phase changing device according to the sixth aspect of the present invention uses a plate-shaped porous member having a cross-sectional shape bent so as to increase the area on which sound waves are incident. Acoustic resistance can be reduced, more ±
A phase difference characteristic close to 180 degrees can be obtained, and a more excellent sound reduction effect can be obtained.

According to a seventh aspect of the present invention, in the sound wave phase changing device, the size of the cross-sectional shape of the porous member is changed along the longitudinal direction so that the area of the porous member to which sound waves are incident increases. As a result, the apparent acoustic mass and acoustic resistance can be reduced, a phase difference characteristic closer to ± 180 degrees can be obtained, and a further excellent sound reduction effect can be obtained.

In the sound wave phase changing device according to the present invention, the sound insulating plate constituting the bottom of the space is inclined with respect to the horizontal direction, and the porous member is connected to the lower end. Therefore, it is possible to prevent rainwater from accumulating in the space when installed outdoors.

In the sound wave phase changing device according to the ninth aspect of the present invention, since a material that transmits light is used as a material of the porous member and the sound insulating plate assembly, the vicinity of the soundproof panel is darkened by the sound wave phase changing device. Can be prevented.

The soundproof wall according to the tenth aspect of the present invention includes a soundproof panel erected near a sound source, a porous member made of a porous material, and a plurality of soundproof panels mounted along an upper end of the soundproof panel. The sound wave phase change device has a sound insulation plate assembly that supports the porous member and has a sound insulation plate assembly that forms a plurality of independent spaces with different volumes on the back of the porous member. In addition, the phase of the incident sound wave can be greatly shifted, thereby increasing the sound reduction effect due to the mutual interference of the sound waves.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a soundproof wall having a sound wave phase changing device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the soundproof wall in FIG.

FIG. 3 is a relationship diagram showing an example of a phase difference θ between an incident sound wave and a reflected sound wave with respect to a frequency f in the sound wave phase changing device in FIG.

FIG. 4 is a sectional view of a main part of a soundproof wall having a sound wave phase changing device according to a second embodiment of the present invention.

FIG. 5 is an explanatory view showing the operation of the soundproof wall in FIG. 4;

FIG. 6 is a sectional view of a main part of a sound wave phase changing device according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a main part of a sound wave phase changing device according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a sound wave phase changing device according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view of a main part of a sound wave phase changing device according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view of a main part of a sound wave phase changing device according to a seventh embodiment of the present invention.

FIG. 11 is a cross-sectional view of a principal part showing a modification of FIG. 10;

FIG. 12 is a sectional view of a main part of a sound wave phase changing device according to an eighth embodiment of the present invention.

FIG. 13 is a sectional view of a main part showing a modification of FIG.

FIG. 14 is a sectional view of a main part of a sound wave phase changing device according to a ninth embodiment of the present invention.

FIG. 15 is a fragmentary cross-sectional view of a sound wave phase changing device according to a tenth embodiment of the present invention.

FIG. 16 is a sectional view of a main part of a sound wave phase changing device according to an eleventh embodiment of the present invention.

FIG. 17 is a fragmentary cross-sectional view of a sound wave phase changing device according to a twelfth embodiment of the present invention.

FIG. 18 is a plan view showing a configuration of a sound wave phase changing device according to Embodiment 13 of the present invention.

FIG. 19 is a plan view showing a modification of FIG. 18;

FIG. 20 is a plan view showing another modification of FIG. 18;

FIG. 21 is a schematic perspective view of a sound wave phase changing device according to Embodiment 14 of the present invention.

FIG. 22 is a schematic perspective view showing a modification of FIG. 21;

FIG. 23 is an explanatory view showing an example of a conventional soundproof wall.

FIG. 24 is an explanatory view showing another example of a conventional soundproof wall.

FIG. 25 is an explanatory view showing the operation of the soundproof wall in FIG. 23.

FIG. 26 is an explanatory view showing the operation of the soundproof wall in FIG. 24.

[Explanation of symbols]

11 sound insulation panel, 12 first sound insulation plate, 13 second sound insulation plate, 14, 31 sound insulation plate assembly, 15, 26, 28,
35, 38, 39, 40 Porous member, 16 spaces, 1
7, 21, 24, 25, 27, 30, 34, 36, 3
7, 41 sound wave phase changing device, 22, 29 corner, 32
The third sound insulating plate, 33 The fourth sound insulating plate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FIG10K 11/178 (72) Inventor Sadao Ogawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (56) References JP-A-2-289333 (JP, A) JP-A-5-61488 (JP, A) JP-A-60-144405 (JP, A) JP-A-52-91514 (JP, A) JP-A-4-147199 (JP, A) JP-A-61-93498 (JP, A) JP-A-1-138909 (JP, U) JP-B-51-46969 (JP, B2) (58) Fields investigated (Int. Cl. ⁶⁾ , DB name) G10K 11/00

Claims (10)

(57) [Claims] 1. A porous member made of a porous material and a plurality of sound insulating plates are combined to form a plurality of independent spaces having different volumes on the back of the porous member to support the porous member. A sound wave phase changing device, comprising: 2. The sound wave phase change device according to claim 1, wherein the porous member is made of a porous material obtained by partially welding a large number of plastic particles. 3. The sound wave phase change device according to claim 1, wherein the sound insulating plate and the porous member exposed to the outside are joined so as to form a corner. 4. The sound wave phase change device according to claim 1, wherein the porous member has a plate shape and a thickness thereof changes. 5. The sound wave phase changing device according to claim 4, wherein the thickness of the porous member is changed by changing the number of layers of the porous member. 6. The porous member according to claim 1, wherein the porous member has a plate-like shape, and has a cross-sectional shape bent so as to increase an area on which a sound wave is incident. 6. The sound wave phase changing device according to any one of 5. 7. The porous member according to claim 1, wherein the size of the entire cross section of the porous member changes along the longitudinal direction so as to increase the area on which the sound wave is incident. A sound wave phase changing device according to any one of the above. 8. The sound insulating plate constituting the bottom of the space is inclined with respect to the horizontal direction, and a porous member is connected to a lower end of the sound insulating plate. Item 8. The sound wave phase changing device according to any one of Items 7. 9. The sound wave phase changing device according to claim 1, wherein the porous member and the sound insulating plate assembly are each made of a material that transmits light. 10. A soundproof panel erected near a sound source,
And a porous member made of a porous material, attached along the upper end of the soundproof panel, and configured by combining a plurality of sound insulation plates, supporting the porous member and supporting the porous member. A soundproof wall comprising: a sound-wave phase changing device having a sound-insulating plate assembly that forms a plurality of independent spaces having different volumes on a back portion.