JP5122859B2 - Noise barrier - Google Patents

Description

  The present invention relates to a silencing wall that is used in a structure that shields a noise source, and that attenuates noise sound waves from the noise source.

Panels with sound-absorbing materials are installed around roads and railways as noise-reducing and sound-proofing structures to prevent noise generated by traveling vehicles and construction sites, etc., and noise generated on one side of the wall is transferred to the other side. There is a known sound-absorbing wall that reduces transmission. For example, in the sound deadening wall (sound absorbing panel) disclosed in Patent Document 1 below, a number of through holes are formed on the panel surface, and sound waves taken from the through holes are attenuated by a sound absorbing material made of a synthetic fiber nonwoven fabric. Yes. In such a sound deadening wall, there is a problem that the amount of noise captured is limited by the aperture ratio of the through holes formed on the panel surface. Moreover, since the sound waves that enter the inside of the panel body through the through holes are reflected on the wall surface that supports the sound absorbing material and leak to the outside again, the trapping property is also poor. That is, assuming that the aperture ratio of the through holes on the panel surface is 50%, the sound wave acting on the sound absorbing material inside the panel body is limited to 50% of the total noise reaching the soundproof wall, and the rest is reflected on the panel surface. It will be repelled outside the body. Moreover, even noise sound waves acting on the sound absorbing material are reflected by a plate body (intermediate plate in Patent Document 1) that supports the sound absorbing material, and are reflected outward from the through holes. It must be said that the sound absorption is low.
Japanese Patent Laid-Open No. 11-323845

  The present invention has been made in response to the problems of the preceding examples, and the problem is to efficiently capture the noise sound wave that has arrived from the noise source and to direct the captured sound wave to the outside. An object of the present invention is to provide a noise reduction wall that promotes attenuation of noise sound waves by making it difficult to leak.

In order to solve the above-mentioned problems, the present invention provides a noise reduction wall for reducing noise sound waves that reach from a noise source, a main body casing having a space of a predetermined volume inside, and a sound absorbing material accommodated in the inner space of the main body casing. a muffling chamber comprising Te, an opening formed in one side surface of the main body casing, the cross-sectional shape is an elliptical curve, reflects the noise sound waves from attached noise source to the opening in the muffler chamber reflection And a folded portion formed by folding back from the opening side end of the reflecting plate toward the inside of the main body casing , and a plurality of the reflecting plates are arranged in a multistage manner between adjacent reflecting plates. to form a noise sound wave introduction path, the focus of one based on cross-sectional shape of the reflecting plate is positioned in said noise sound wave introduction path, the other focal point of the folded portion of the outside of the main body casing Suggest muffling walls, characterized in that is located on the longer line.

  In the proposed silencing wall, it is desirable that a part of the noise sound wave introduction path is formed by the sound wave reflection surface and the folded portion of the reflection plate.

  In addition, a noise sound wave introduction port is formed between the respective front ends of the adjacent reflection plates at the opening side end of the reflection plate, and a reflected sound wave introduction port is provided between the front end of the main body casing of the reflection plate and the front end of the folded portion. It is desirable that the reflected sound wave inlet is smaller than the noise sound wave inlet.

  According to the present invention, the noise sound wave that arrives from the noise source is captured in the silencer chamber in the main body casing by the reflection plate provided in the opening of the main body casing. At this time, since the noise sound wave is captured in a range corresponding to the surface area of the reflection plate, the noise sound wave can be captured efficiently. In addition, a noise sound wave introduction path is formed between the reflectors arranged in multiple stages, and the focal point resulting from the cross-sectional shape of the reflection plate is positioned in the noise sound wave introduction path. The noise sound wave reflected by is reflected toward the inside of the main casing, and as a result, is efficiently captured in the silencer chamber.

  Further, a folded portion is formed from the opening side end of the reflecting plate toward the muffle chamber inside the main casing, and noise sound waves are generated by one reflecting surface and the other folded portion of the reflecting plate constituting the sound wave introduction path. Since it forms a part of the introduction path, even if the noise sound wave captured from the noise sound wave introduction path is reflected by the inner wall of the silencer chamber and radiated toward the outside of the main body casing, Radiation to the outside can be prevented by hitting the surface facing.

  In addition, since the reflected sound wave inlet that takes in the noise sound wave from the noise sound wave introduction path is made smaller than the noise sound wave inlet that takes the noise sound wave that arrives from the noise sound source, the sound wave captured in the sound deadening room is It becomes difficult to radiate to the outside of the main body casing, and the noise sound wave attenuation effect in the muffler chamber can be enhanced.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view showing a sound deadening wall of the embodiment of the present invention, and FIG.
Reference numeral 1 denotes a main casing, which is constructed by assembling plate-like members made of a metal material into a box shape, forming an opening 1a on the front surface, and a sound absorbing material made of a porous material or a fibrous material such as glass wool or rock wool inside. 2 is formed. Reference numeral 3 denotes a reflector, which is attached between the side walls 1c of the main casing 1 in a state of being inclined upward from the opening 1a opened on the front surface of the main casing 1 toward the muffler chamber 1b inside the main casing 1.

  The reflection plates 3 are arranged in a multi-stage manner with a predetermined interval in the vertical direction of the main casing 1, and a noise sound wave introduction path 4 is formed between the reflection plates 3 adjacent in the vertical direction. And the folding | returning part 3b is formed toward the main body casing inner side in the noise sound wave introduction path 4 from the opening part side front end 3a of the reflecting plate 3. As shown in FIG. The folded portion 3 b extends to the vicinity of the center of the noise sound wave introduction path 4 toward the inner end 3 c of the main body casing of the reflector 3 adjacent to the lower side of the first stage, and constitutes a part of the noise sound wave introduction path 4. ing. In addition, a noise sound wave introduction port 5 is formed between each opening side tip 3a of the reflectors 3 arranged in multiple stages in the vertical direction, from the reflectors located on the upper side of the reflectors 3 that are also vertically aligned. A reflected sound wave introduction port 6 is formed between the folded portion tip 3d of the folded portion 3b that is extended and the main body casing inside tip 3c of the reflector plate located on the lower side. That is, a noise sound wave introduction port 5 is formed on the front surface of the main body casing 1, and a reflected sound wave introduction port 6 is formed in the middle of the noise sound wave introduction path 4 that leads from the noise sound wave introduction port 5 to the muffler chamber 1 b inside the main body casing 1. Has been. The opening size of the reflected sound wave introduction port 6 is set smaller than the opening size of the noise sound wave introduction port 5. This is to make it easier for noise sound waves to enter the muffling chamber 1b and to make it difficult for noise sound waves that have once entered the muffling chamber 1b to return to the outside from the muffling chamber.

  By the way, the reflecting plate 3 has a cross-sectional shape that draws a curve as shown in FIG. 2, and is specifically formed to draw an elliptic curve. In the figure, f1 and f2 are two focal points based on the elliptical shape of the reflecting plate 3, and the first focal point f1 has substantially the same position as the folded portion tip 3d of the folded portion 3b. On the other hand, the second focal point f2 is placed in the space in front of the main body casing 1, and in particular in the present embodiment, is aligned with the extension line of the folded portion 3b folded at a predetermined angle from the opening side tip 3a of the reflecting plate 3. Yes.

  As shown in FIG. 3, the elliptical shape given to the reflecting plate 3 is a continuous elliptic curve in which a flat plate is formed into an elliptical shape by using a mold or the like (FIG. 3A), and the flat plate is formed by a sheet metal processing machine. Any of the approximate elliptic curves (FIG. 3B) formed by fine bending may be adopted. In the case of a continuous elliptic curve, the range of the focal points f1 and f2 is accurate in a narrower range, and in the case of a pseudo elliptic curve, the range of the focal points f1 and f2 is slightly widened and ambiguous. However, the difference between the two is sufficiently acceptable for obtaining a silencing effect.

  In this way, one unit of the sound deadening wall is configured. This one unit is the minimum unit for handling that is constituted by the same main body casing 1, and a plurality of units can be installed side by side or stacked in the vertical direction depending on the installation location. 1 and 2, ribs 7 formed by extending from the back plate on the upper surface of the main body casing 1 are formed on the lower back surface of the main body casing of the upper unit. It has an overlapping structure. A concave portion is formed in the portion where the rib 7 overlaps by the thickness of the rib so that no step is generated on the back plate in a state where the units are stacked vertically. The ribs 7 can prevent a gap from being formed between the units stacked one above the other from the front side to the back side, and noise can be transmitted from the noise source side to the other side via the gap. It can be prevented from being transmitted.

Next, the operation and action of the present embodiment will be described with reference to FIG.
The noise reduction wall of the present invention is installed between a noise source (not shown) and a silent area where noise is desired to be blocked with the opening 1a of the main casing 1 facing the noise source. The noise sound wave W that has arrived from the noise source enters the noise sound wave introduction path 4 from the noise sound wave introduction port 5, is reflected by the elliptical surface of the reflector 3, and enters the inside of the silencer chamber 1 b from the reflected sound wave introduction port 6. Go further. In this case, as already described, the elliptical focus f1 of the reflector 3 is set so that the position thereof is substantially the same as that of the folded portion tip 3d of the folded portion 3b, and the other focal point f2 is set as the main casing. 1, most of the sound waves that reach from a distant noise source enter the noise sound wave introduction path 4 without passing between the focal points f 1 and f 2. Therefore, reflection occurs at the elliptical reflection surface of the reflector 3 without passing between the focal points f1 and f2, and the noise sound wave after reflection does not pass between the focal points f1 and f2, and the noise sound wave introduction path 4 As a result, it enters the inside of the muffler chamber 1b through the reflected sound wave inlet 6 as a result.

  The noise sound wave incident on the sound deadening chamber 1b is reflected by irregular reflection in the sound deadening chamber so that reflected waves with mutually reversed phases come out and cancel each other out energy, or the energy of the sound sound wave is reduced by the action of the sound absorbing material 2. As a result, the energy of the sound wave is greatly reduced, and a silencing effect is obtained. At this time, since the opening size of the reflected sound wave introduction port 6 is set smaller than the opening size of the noise sound wave introduction port 5, the sound is silenced with respect to the noise sound wave entering the silencer chamber 1 b from the outside where the noise source is present. The sound wave returning from the chamber 1b to the outside is reduced, and the energy of the noise sound wave can be sufficiently attenuated in the silencer chamber.

  As mentioned above, although the present Example demonstrated by the form which made the cross-sectional shape of a reflecting plate an elliptic curve, these are not specifically limited, Various embodiments can be considered within the technical scope of this invention. For example, the cross-sectional shape of the reflecting plate may be a parabola, and the parabola may be set at a position where the focal point of the parabola is closer to the sound deadening chamber 1b than the folded part tip 3d.

It is external appearance explanatory drawing which shows the noise-reduction wall of this invention Example. It is internal cross-section explanatory drawing which shows the noise-reduction wall of this invention Example. It is explanatory drawing about the curve shape given to the reflecting plate 3 of an Example of this invention. It is sectional explanatory drawing which shows operation | movement and an effect | action of an Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body casing 1a Opening part 1b Silencer chamber 2 Sound absorbing material 3 Reflector 3a Opening side side front end 3b Folding part 3c Main body casing inner front end 3d Folding part front end 4 Noise sound wave introduction path 5 Noise sound wave introduction port 6 Reflected sound wave introduction port 7 Rib f1 , F2 focus W noise sound wave

Claims (3)

In the sound deadening wall that reduces the noise sound wave that reaches from the noise source,
A main body casing having a space of a predetermined volume inside;
A sound deadening chamber containing a sound absorbing material in the internal space of the main body casing;
An opening formed on one side of the main body casing;
A reflecting plate that has an elliptic curve in cross- section and is attached to the opening and reflects noise sound waves from a noise source toward the muffler chamber;
A folded portion formed by folding back from the opening side tip of the reflector toward the inside of the main body casing ;
A plurality of the reflection plates are arranged in a multi-stage shape to form a noise sound wave introduction path between adjacent reflection plates, and one focal point based on the cross-sectional shape of the reflection plate is positioned in the noise sound wave introduction path And the other focal point is positioned on an extension line of the folded portion outside the main body casing .   The sound deadening wall according to claim 1, wherein a part of the noise sound wave introduction path is formed by a sound wave reflection surface of the reflection plate and the folded portion.   A noise sound wave introduction port is formed between the respective front ends of the adjacent reflectors at the front end of the reflector on the opening side, and the reflection is reflected between the main body casing inner front end of the reflector and the folded portion front end. The sound deadening wall according to claim 1, wherein a sound wave introduction port is configured, and the reflected sound wave introduction port is made smaller than the noise sound wave introduction port.

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