JP3806566B2 - Soundproofing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a soundproofing device that is installed to insulate and absorb noise associated with traveling of a vehicle or the like.
[0002]
[Prior art]
In order to reduce the noise associated with the traveling of vehicles, etc., noise on the backside of girders can be installed as noise barriers on expressways and railways, between sidewalks and roadways, as median strips, and on the backside of viaducts and bridge girders. As shown in FIG. 8, as a sound-absorbing plate on the back side of the girders for reducing noise, and as a soundproofing equipment for other digging roads, it is formed by a front part b having a large number of openings a and a rear part c having sound insulation properties. A sound absorbing material d is housed in the hollow, a back air layer e is provided between the sound absorbing material d and the back surface portion c, and a spacer f interposed between the front surface portion b and the sound absorbing material d. Thus, a soundproof device in which a front air layer g is formed between the front surface portion b and the sound absorbing material d is used. The spacer f is generally composed of an upper surface portion h for mounting on the inner surface of the front surface portion b, a side surface portion i for securing a predetermined front air layer g depth, and a lower surface for pressing the sound absorbing material d. Part j.
[0003]
[Problems to be solved by the invention]
In the soundproofing device as described above, the noise N incident in the hollow from the opening a of the front surface portion b is absorbed by the sound absorbing material d and is also sound-insulated by the back surface portion c so that it does not leak outside from the back surface portion c. The low-frequency noise N is effectively reduced by the rear air layer e, and the front air layer g is provided between the front part b and the sound absorbing material d as described above. Therefore, the noise N that has entered the hollow through the opening a of the front surface portion b is repeatedly diffusely reflected in the front air layer g between the protective material k enclosing the sound absorbing material d and the front surface portion b. Since the sound is absorbed by d and attenuated by interfering with each other, the oblique incident sound absorption coefficient is increased.
[0004]
However, as shown in FIG. 8, the conventional spacer f uses a square pipe having a flat side surface portion i, ie, a so-called square cross section. Reflected toward the sound absorbing material d by the flat side surface portion i of the spacer f, part of the reflected noise N is re-reflected by the protective material k enclosing the sound absorbing material d and emitted to the outside. When viewed only with respect to the spacer f such that the advanced noise N is reflected by the upper surface portion h of the spacer f, the conventional square spacer f has an adverse effect on the oblique incident sound absorption coefficient.
[0005]
For example, as described above, the average oblique incident sound absorption coefficient of the soundproofing device in the form shown in FIG. 8 was measured, as shown in FIG. 9, and the average value of the average oblique incident sound absorption coefficient was 0.862. .
[0006]
Incidentally, the average oblique incident sound absorption coefficient is defined as four types of noise incident angles of 0 degree (normal incidence), 15 degrees, 30 degrees, and 45 degrees, and the sound absorption coefficient obtained by measuring at each angle is arithmetically averaged. The value is measured every 1/3 octave center frequency Hz, and FIG. 9 is a graph of the value, and the average value of the average oblique incident sound absorption coefficient is a weighted average of those values. It is.
[0007]
Accordingly, the present invention is intended to solve the above-described problems and to provide a soundproofing device with improved oblique incidence sound absorption coefficient.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
That is, the soundproofing device according to claim 1 according to the present invention includes a sound absorbing material housed in a hollow formed by a front surface portion having a large number of openings and a back surface portion having sound insulation properties, and a front surface portion. And a sound absorbing device in which a front air layer is formed between the front surface portion and the sound absorbing material by a spacer interposed between the sound absorbing material and the sound absorbing material, wherein the side surface portion of the spacer has a concave groove shape. It is a feature.
[0009]
According to the present invention, since the side surface portion of the spacer is formed into a concave groove shape, the noise that is obliquely incident into the hollow and reaches the side surface portion of the spacer is generated between the opposing inner walls of the concave groove side surface portion of the spacer. Since the reflection is repeated and attenuated, the decrease in the oblique incident sound absorption coefficient due to the side surface portion of the spacer can be suppressed.
[0010]
According to a second aspect of the present invention, there is provided a soundproofing device, wherein a sound absorbing material is housed in a hollow formed by a front part having a large number of openings and a rear part having sound insulation, and a front part. A soundproofing device in which a front air layer is formed between a front surface portion and a sound absorbing material by a spacer interposed between the sound absorbing material, and a plurality of openings are formed in the upper surface portion and the side surface portion of the spacer. It is characterized by that.
[0011]
According to the present invention, since a large number of openings are formed in the spacer, noise does not reflect on the top surface and side surfaces of the spacer and passes through the openings, so the top surface and side surfaces of the spacer. It is possible to suppress a decrease in oblique incident sound absorption coefficient.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be specifically described with reference to the drawings.
First, FIG. 1 is a sectional view showing an embodiment of a soundproofing device according to the first aspect of the present invention.
[0013]
The soundproofing device shown in the form of FIG. 1 has a sound absorption in a hollow formed by a front surface portion 1 in which a large number of openings 11 formed in almost the entire surface are formed and a back surface portion 2 having sound insulation properties. The material 3 is internally provided, and a back air layer 4 is formed between the sound absorbing material 3 and the back surface portion 2, and the front surface portion 1 is separated by a spacer 5 interposed between the front surface portion 1 and the sound absorbing material 3. A front air layer 6 is formed between the sound absorbing material 3, and noise N incident into the hollow through the opening 11 of the front surface portion 1 is absorbed by the sound absorbing material 3 and is also sound-insulated by the back surface portion 2. In addition, noise in the low frequency range is effectively attenuated by irregular reflection or the like in the back air layer 4, and further, irregular reflection is repeated in the front air layer 6 between the front surface portion 1 and the sound absorbing material 3, which is the sound absorbing material. 3 is absorbed and attenuated by interfering with each other, and their synergistic effect The one in which oblique incidence sound absorption coefficient is enhanced.
[0014]
The front portion 1 is generally formed of an aluminum alloy plate, an iron plate, or a stainless plate, and the surface thereof is appropriately coated with a coating for improving corrosion resistance, but is not particularly limited. The opening 11 may be a slit hole provided with a flange, and is not particularly limited. However, if the hole 11 is a punching hole, the surface of the front face 1 is substantially flat compared to the slit hole. Easy to clean and wash. In addition, although the aperture ratio of the front part 1 in which the opening part 11 was formed is preferably 15 to 50%, it is not particularly limited.
[0015]
As the sound absorbing material 3, generally, a fibrous material such as glass wool is appropriately used, but is not particularly limited. The sound absorbing material 3 is preferably wrapped with a protective material 31 in order to improve weather resistance and further protect it from rainwater. As the protective material 31, generally a polyvinyl fluoride film or a tetrafluorofluoroethylene film excellent in waterproofness and durability is used, but this is not limited, and a glass cloth or the like may be used. Furthermore, as shown in FIG. 2 to be described later, the above-described film or the like may be first wrapped with the internal protective material 311 as an internal protective material 311 and further covered with an external protective material 312 such as a glass cloth. The thickness of the sound absorbing material 3 is preferably 50 to 100 mm, but is not particularly limited.
[0016]
The back surface portion 2 is a back surface made of a metal plate or the like made of a metal plate as exemplified in the front surface portion 1 so as to satisfy the required transmission loss so that the noise N does not transmit to the outside from the back surface portion 2. 2, a front panel 1 and a back panel 2 may form a hollow panel body, and a back air layer 4 may be formed between the back panel 2 and the sound absorbing material 3. Thus, when attaching to the wall surface of a viaduct, a bridge, a digging road, or the like, that is, the wall surface of the structure 7, the back surface portion 2 is not particularly formed by another plate material or the like, and the wall surface of the structure 7 to be attached is used as the back surface portion 2. It is good. For example, the soundproofing device is attached to the wall surface with the mounting bracket 71 and the anchor bolt 72 while adjusting the unevenness, and the back air layer 4 is formed between the sound absorbing material 3 and the back surface portion 2 that is the wall surface. Also good. The depth dimension of the back air layer 4 is preferably 5 to 50 mm, but is not particularly limited.
[0017]
The spacer 5 includes an upper surface portion 51 for mounting on the inner surface of the front surface portion 1, a side surface portion 52 for securing a predetermined depth dimension of the front air layer 6, and a lower surface portion 53 for pressing the sound absorbing material 3. The constructed cross section has a substantially inverted Z shape, and the side surface portion 52 has a concave groove shape. The depth dimension of the front air layer 6 secured by the spacer 5 is preferably 5 to 50 mm, but is not particularly limited.
[0018]
By making the side surface portion 52 of the spacer 5 into a concave groove shape as described above, the noise N that is obliquely incident into the hollow and reaches the concave groove side surface portion 52 is the relative noise constituting the concave groove side surface portion 52. Reflecting and attenuating between the facing inner walls 54, the oblique incident sound absorption coefficient is improved.
[0019]
The results of measuring the average oblique incidence sound absorption coefficient of the soundproofing device shown in FIG. 1 are shown in FIG. The measurement is the same as described in the conventional soundproofing device using the square spacer as described above. As shown in the graph of FIG. 6, the drop in the sound absorption coefficient near 2500 Hz is improved as compared with the case where the square spacer is used, and the average value of the average oblique incident sound absorption coefficient is 0.876. The average value of the incident sound absorption coefficient is also improved.
[0020]
In addition, in the said form, in order to make the side part 52 into a concave groove shape, the spacer 5 whose cross section is substantially reverse Z shape is used, However, The side part 52 is a concave groove shape, The inner wall which opposes it As long as noise can be repeatedly reflected between 54, the present invention is not limited to this. For example, it may be U-shaped as shown in FIG. 3, and the upper surface portion 51 is compared with the lower surface portion 53 as shown in FIG. 4. Wide and substantially I-shaped.
[0021]
Next, the soundproofing device according to the second aspect of the present invention will be described with reference to FIG. In this form, the spacer 5 is different from the form shown in FIG. 1, and other front part 1, back part 2, sound absorbing material 3, back air layer 4, front air layer 6 and the like have been described in FIG. Since the content is almost the same, only the spacer 5 will be described. That is, the spacer 5 in the form shown in FIG. 5 has a large number of openings 55 formed in the upper surface portion 51, the side surface portion 52, and the lower surface portion 53, and the noise N is the upper surface portion 51 of the spacer 5 or The light passes through the opening 55 without being reflected by the side surface 52 or the like.
[0022]
The spacer 5 does not require noise to pass through the opening 55 and be reflected by the upper surface portion 51, the side surface portion 52, etc., so that the side surface portion 52 as shown in FIG. For example, as shown in FIG. 5, the side surface portion 52 may be an inverted U-shape with a flat shape, a square shape, or the like.
[0023]
The hole shape of the opening 55 of the spacer 5 is not particularly limited, but it is preferable to create the spacer 5 by bending a punching plate in which a large number of punching holes are formed because the processing is easy.
[0024]
The average oblique incident sound absorption coefficient of the soundproofing device in the form shown in FIG. 5 was measured in the same manner as described above, and the result is shown in FIG. As shown in the graph of FIG. 7, compared with the case where a square spacer is used, the sound absorption device near 2500 Hz is used, as in the case of the soundproofing device using the spacer having the concave groove side surface portion shown in FIG. The drop in rate is improved, the average value of the average oblique incident sound absorption coefficient is 0.876, and the average value of the average oblique incident sound absorption coefficient is also improved.
[0025]
【The invention's effect】
According to the first aspect of the present invention, since the side surface portion of the spacer is formed in a concave groove shape, the noise incident obliquely into the hollow and reaching the side surface portion of the spacer is relative to the concave groove side surface portion of the spacer. Since the reflection is repeatedly attenuated between the inner walls facing each other, it is possible to suppress a decrease in the oblique incident sound absorption coefficient due to the side surface portion of the spacer.
[0026]
According to the second aspect of the present invention, since a large number of openings are formed in the spacer, noise does not reflect on the upper surface and side surfaces of the spacer and passes through the opening. Further, it is possible to suppress a decrease in the oblique incident sound absorption coefficient due to the side portion.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a soundproofing device according to the present invention.
FIG. 2 is a cross-sectional view showing another embodiment of the soundproofing device according to the present invention.
FIG. 3 is a cross-sectional view showing still another embodiment of the soundproofing device according to the present invention.
FIG. 4 is a cross-sectional view showing still another embodiment of the soundproofing device according to the present invention.
FIG. 5 is a cross-sectional view showing still another embodiment of the soundproofing device according to the present invention.
FIG. 6 is a graph showing the oblique incidence sound absorption coefficient of the soundproofing device according to the present invention.
FIG. 7 is a graph showing the oblique incidence sound absorption coefficient of the soundproofing device according to the present invention.
FIG. 8 is a cross-sectional view showing one embodiment of a conventional soundproofing device.
FIG. 9 is a graph showing an oblique incident sound absorption coefficient of a conventional soundproofing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front part 11 Opening part 2 Back part 3 Sound absorption material 31 Protective material 4 Back surface air layer 5 Spacer 51 Upper surface part 52 Side surface part 53 Lower surface part 54 Inner wall 55 Opening part 6 Front air layer 7 Structure 71 Mounting bracket 72 Anchor bolt

Claims (2)

A sound absorbing material is housed in a hollow formed by a front part having a large number of openings and a back part having sound insulation properties, and a spacer interposed between the front part and the sound absorbing material allows the front part to A soundproofing device in which a front air layer is formed between the sound absorbing material and a side surface of the spacer having a concave groove shape. A sound absorbing material is housed in a hollow formed by a front part having a large number of openings and a back part having sound insulation properties, and a spacer interposed between the front part and the sound absorbing material allows the front part to A soundproofing device in which a front air layer is formed between the sound absorbing material and a plurality of openings are formed in an upper surface portion and a side surface portion of the spacer.

Images