JP5808287B2 - Sound barrier - Google Patents

Description

  The present invention relates to a soundproof wall for reducing noise generated in railways, roads, factories and the like.

  The height of soundproof walls used for railways is determined in consideration of damage prevention due to wind loads such as during typhoons (there are wind load design conditions (wind resistant design)). Conventional upright soundproof walls that have been used in the past are strongly affected by wind loads, and are therefore made to be low in height. When the height of the soundproof wall is lowered, the noise reduction effect is lowered while the design condition of the wind load can be satisfied. Here, as a technique regarding the soundproof wall, for example, there is one described in Patent Document 1.

  The soundproof wall described in Patent Document 1 is obtained by providing a sound absorbing unit at a tip portion of a main body wall constituting the soundproof wall so as to branch from the main body wall. According to this structure, since the sound diffraction effect from the sound source to the observation point is increased, the noise reduction effect can be obtained more than that of the conventional upright sound barrier even at the same height as the conventional upright sound barrier.

JP-A-11-293632

  However, even with the tip-branch type soundproof wall described in Patent Document 1, as with the conventional upright soundproof wall, it is not possible to raise the height of the soundproof wall from the conventional level due to restrictions imposed by the design conditions of the wind load. Can not. That is, there is a limit to the noise reduction effect obtained by the tip branch structure because the height of the soundproof wall cannot be increased. Further, the tip-branch type soundproof wall described in Patent Document 1 is likely to collect rain, snow, and the like at the branch portion. For example, when snow accumulates on a branch portion, there is a problem that a high load is applied to the sound absorption unit or the like of the branch portion.

  The present invention has been made in view of the above circumstances, and its purpose is to increase the height as compared with the prior art and to prevent rain and snow from accumulating while obtaining a sound diffraction effect. It is to provide a sound barrier.

  The present invention is a soundproof wall having a main body wall and a rotating portion disposed on the main body wall. The rotating portion includes a rotating shaft that is rotatable about the length direction of the main body wall, and a rotating wall that is attached to the rotating shaft so as to extend from the rotating shaft in a radial direction of the rotating shaft. I have.

  According to the present invention, it is possible to provide a soundproof wall in which the height can be increased as compared with the prior art, and rain and snow are not easily collected while obtaining a sound diffraction effect.

It is a figure which shows the soundproof wall which concerns on one Embodiment of this invention. It is a perspective view of the rotation part shown in FIG. It is a figure which shows the modification of the soundproof wall shown in FIG. It is a figure for demonstrating the analysis conditions of a noise reduction effect. It is a graph which shows the analysis result of a noise reduction effect. It is a graph which shows the analysis result of a noise reduction effect. It is a graph which shows the analysis result of a noise reduction effect.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1A is a cross-sectional view of a soundproof wall 100 according to an embodiment of the present invention. Moreover, FIG.1 (b) is a front view of the soundproof wall 100 (A arrow line view of Fig.1 (a)). The soundproof wall 100 of this embodiment is provided on both sides of a railway track, for example, on an elevated structure of a high-speed railway such as a railway, particularly a Shinkansen. Note that the soundproof wall 100 may be used as a soundproof wall for roads (for example, highways) and factories. In the following description, the soundproof wall 100 will be described as a soundproof wall for railways.

(Configuration of sound barrier)
As shown in FIG. 1, the soundproof wall 100 includes a main body wall 1 installed in an upright posture, a rotating unit 2 arranged on the main body wall 1 installed in an upright posture (on the vertical direction), Is provided. The main body wall 1 is fixed on an elevated structure of a high-speed railway such as a Shinkansen. In the present application, “upright” does not mean to stand in the straight vertical direction. That is, in the present application, “upright” includes standing slightly inclined with respect to the vertical direction. Further, the main body wall 1 may not be installed in an upright posture.

(Body wall)
The main body wall 1 is installed along the track. A plurality of main body walls 1 having a predetermined length are arranged side by side along the track to form a continuous wall along the track. The main body wall 1 may be a hollow wall or a solid wall. The material of the main body wall 1 may be a metal such as iron, stainless steel, or an aluminum alloy, concrete, or resin.

(Rotating part)
A perspective view of the rotating unit 2 is shown in FIG. As shown in FIGS. 1 and 2, the rotating unit 2 includes a rotating shaft 3 and a rotating wall 4. Here, the rotating shaft 3 is rotatable about the length direction D of the main body wall 1 as an axis. The rotating shaft 3 is supported by the main body wall 1 through a bearing or the like, for example. In installing the rotating shaft 3, it is not always necessary to support the main body wall 1. The rotating shaft 3 may be a hollow rod-shaped body or a solid rod-shaped body. The material of the rotating shaft 3 may be a metal such as iron, stainless steel, and aluminum alloy, or may be a resin.

  A rotating wall 4 is attached to the rotating unit 2. In the present embodiment, three rotating walls 4 are arranged around the rotating shaft 2 with an equal phase difference every 120 °. Each of the rotating walls 4 is attached to the rotating shaft 3 so as to extend from the rotating shaft 3 in the radial direction of the rotating shaft 3. When the rotating wall 4 that rotates is positioned vertically downward, the gap between the rotating wall 4 and the main body wall 1 is preferably small. Moreover, although it is preferable to arrange three or more rotating walls 4 around the rotation axis 2, the number of the rotating walls 4 is not limited to three or more. When three or more rotating walls 4 are arranged around the rotating shaft 2, it is preferable to arrange the rotating walls 4 with equal phase differences.

  In the present embodiment, the rotating wall 4 is a rotating wall having a single-sided sound absorption structure. Specifically, one surface of the rotating wall 4 in the direction R in which the rotating wall 4 rotates around the axis of the rotating shaft 3 is a sound absorbing surface 4a. A large number of holes 5 are formed in the sound absorbing surface 4a. In addition, a porous material (porous body) such as glass wool is placed in the rotating wall 4. The surface of the rotating wall 4 opposite to the sound absorbing surface 4a is not provided with a hole 5, that is, a sound insulating surface 4b. The holes 5 are for guiding sound waves to the porous material (porous body) in the rotating wall 4 and may have any shape. An ellipse may be sufficient, a perfect circle may be sufficient, and other shapes may be sufficient. The sound that enters the rotating wall 4 from the hole 5 is absorbed by a porous material (porous body) such as glass wool.

  Further, the three rotating walls 4 have a sound absorbing surface 4a (or sound insulating surface 4b) on the same side in the direction R in which the rotating wall 4 rotates. The direction R in which the rotating wall 4 rotates has two directions, clockwise and counterclockwise. However, the three rotating walls 4 are in the direction R in which the rotating wall 4 rotates. The surface on the same side is the sound absorbing surface 4a (or sound insulating surface 4b). Here, in FIG. 1A, for example, it is assumed that the train travels on the left side of the main body wall 1 (soundproof wall 100) (the noise source is on the left side of the soundproof wall 100). As described above, in the present embodiment, regarding the three rotating walls 4, the same side surface in the direction R in which the rotating wall 4 rotates is the sound absorbing surface 4 a (or the sound insulating surface 4 b). When the rotating unit 2 is viewed from the left side of the soundproof wall 100 in FIG. 1A, even if the rotating wall 4 rotates, the ratio between the sound absorbing surface 4a and the sound insulating surface 4b does not change greatly. That is, the change in the noise reduction effect at each angle of the rotating wall 4 is suppressed.

  In addition, the porous wall (air body) is made into the space (air layer) without putting the porous material (porous body) in the rotating wall 4, and the sound is absorbed into the rotating wall 4 by appropriately determining the diameter of the hole 5. An effect may be given.

  Further, both surfaces of the rotating wall 4 in the direction R in which the rotating wall 4 rotates may be sound absorbing surfaces, and both surfaces of the rotating wall 4 in the direction R in which the rotating wall 4 rotates may be sound insulating surfaces. Note that no holes are formed in the surface of the main body wall 1 on the noise source side. That is, the main body wall 1 is a sound insulation wall. As with the rotating wall 4, the main body wall 1 may have a sound absorbing effect so that the main body wall 1 has a sound absorbing structure.

  The material of the casing of the rotating wall 4 that stores the porous material (porous body) may be a metal such as iron, stainless steel, or aluminum alloy, or may be a resin.

  When the rotating wall 4 is a sound insulating wall without sound absorption, no hole is formed in the casing of the rotating wall 4. In this case, the rotating wall 4 may be a hollow wall or a solid wall.

(Results of noise reduction analysis)
Here, when the rotating wall 4 is in the posture shown in FIG. 1, the noise reduction effect is improved because the sound diffraction effect is larger than the upright soundproof wall having the same height as the soundproof wall 100. However, when the rotating wall 4 is rotated from the posture of FIG. 1 and the angle thereof is changed, the noise reduction effect is caused by the change of the angle of the rotating wall 4 and the gap between the rotating wall 4 and the main body wall 1. It may change. Therefore, the noise reduction effect of the soundproof wall 100 was analyzed at each angle shown in FIG. The rotating wall 4 of the rotating unit 2 performs analysis in three patterns: a rigid wall (double-sided sound insulation), a single-sided sound-absorbing wall (the rotating wall 4 itself shown in FIG. 1), and a double-sided sound absorbing wall.

  As shown in FIG. 4, when one of the three rotating walls 4 is vertically downward, it is defined as 0 °, and 0 °, 30 °, 60 °, and 90 °, respectively. The noise reduction effect of the noise barrier 100 was examined. The comparison target was an upright soundproof wall 500. The soundproof wall 500 has a sound absorbing surface 51 on its upper side surface (noise source side).

  In order to make the conditions the same, the total height of the soundproof wall 100 when one of the three rotating walls 4 is vertically downward and the total height of the soundproof wall 500 to be compared are both 3 m. Further, the height of the rotating portion 2 in the side view of the soundproof wall 100 when one of the three rotating walls 4 is vertically downward, and the height of the sound absorbing surface 51 of the soundproof wall 500 to be compared are both set. 1 m.

  The noise source was a sound source at the top of the vehicle, such as a current collector. Further, it is assumed that there is a noise source on the left side of the soundproof wall (100, 500) in FIG. Then, the sound pressure level at a point 25 m away from the noise source (25 m point sound pressure level) was obtained by numerical analysis.

<When the rotating wall of the rotating part is a rigid wall (double-sided sound insulation)>
FIG. 5 is a graph showing the analysis result of the noise reduction effect when the rotating wall of the rotating part is a rigid wall (double-sided sound insulation). The horizontal axis of the graph is the frequency (1/3 oct), and the vertical axis is the sound pressure level reduction amount. The sound pressure level reduction amount is based on the 25 m point sound pressure level of the soundproof wall 500 to be compared (upper soundproof wall of the sound absorbing surface 51 is the upper 1 m). In other words, the sound pressure level reduction amount of 0 means that the sound pressure level is the same as that of the soundproof wall 500 to be compared at the observation point.

  As can be seen from FIG. 5, 0 ° (when one of the three rotating walls 4 is vertically downward) has the largest sound pressure level reduction amount and the greatest noise reduction effect. The sound pressure reduction amount is larger than that of the soundproof wall 500. The soundproof wall 500 to be compared has a sound absorbing surface 51 at the top 1 m. On the other hand, the rotating wall of the soundproof wall 100 according to the present embodiment is a rigid wall (double-sided sound insulation) (no sound absorbing effect). Nevertheless, the soundproof wall 100 according to the present embodiment has a greater noise reduction effect than the soundproof wall 500 to be compared. This is because a large sound diffraction effect is obtained.

<When the rotating wall of the rotating part is a single-sided sound absorbing wall>
FIG. 6 is a graph showing the analysis result of the noise reduction effect when the rotating wall of the rotating part is a single-sided sound absorbing wall. In this graph as well, the sound pressure level reduction amount on the vertical axis is based on the 25 m point sound pressure level of the soundproof wall 500 (upper soundproofing wall of the sound absorbing surface 51 is the upper portion 1m) as a comparison target (in FIG. 7). The same).

  Comparing FIG. 5 and FIG. 6, it can be seen that when the rotating wall is a sound absorbing wall, the amount of sound pressure level reduction is greater at each angle than when no sound is absorbed (sound insulation).

<When the rotating wall of the rotating part is a double-sided sound absorbing wall>
FIG. 7 is a graph showing the analysis result of the noise reduction effect when the rotating wall of the rotating part is a double-sided sound absorbing wall. Comparing FIG. 6 and FIG. 7, it can be seen that if the rotating wall is a double-sided sound-absorbing wall, the amount of sound pressure level reduction is greater at each angle than in the case of a single-sided sound-absorbing wall. Further, comparing the three graphs of FIGS. 5 to 7, the difference in the sound pressure level reduction amount at each angle is small in the order of double-sided sound absorption, single-sided sound absorption, and no sound absorption (sound insulation). This means that even if the rotating wall 4 rotates or the rotating wall 4 rotates and stops at an arbitrary angle, the noise reduction effect does not vary.

  From the analysis results of these three patterns, the soundproof wall 100 according to the present embodiment is more upright than the soundproof wall whether the rotating wall 4 has no sound absorption (sound insulation) or has sound absorption (sound absorption wall). It can also be seen that the noise reduction effect is increased. Moreover, since the wind load is reduced by the rotating portion 2 of the soundproof wall 100 of this embodiment, the height dimension can be made larger than that of the upright soundproof wall, and the noise reduction effect is further increased. In this respect, the noise reduction effect is greater than that of the conventional tip branch type soundproof wall.

(Modification)
FIG. 3 is a view showing a modification of the soundproof wall 100 shown in FIG. In addition, the same code | symbol is attached | subjected about the structural member similar to the structural member of the soundproof wall 100 shown in FIG. 3 (a) and 3 (b) are diagrams corresponding to FIG. 1 (a). That is, both FIG. 3A and FIG. 3B are cross-sectional views of the soundproof wall.

  A soundproof wall 101 shown in FIG. 3A includes a plurality of rotating units 2. In the soundproof wall 101 of this modification, two rotating parts 2 are arranged adjacent to each other in the vertical direction. As described above, two or more rotating portions 2 may be provided. The rotating wall 4 may be a double-sided sound absorbing wall instead of a single-sided sound absorbing wall, or a wall body without sound absorption (sound insulation) (the same applies to FIG. 3B).

  The soundproof wall 102 shown in FIG. 3 (b) is obtained by installing an upright auxiliary wall 6 above the rotating unit 2. Compared to the soundproof wall 100 shown in FIG. 1, in the soundproof wall 102 of this modification, the height of the main body wall 1 is made lower than that of the soundproof wall 100 shown in FIG. An upright auxiliary wall 6 is installed vertically above the rotary shaft 3. When the rotating wall 4 that rotates is positioned vertically upward, the gap between the rotating wall 4 and the auxiliary wall 6 is preferably small. The auxiliary wall 6 has a noise absorbing surface 6a on the surface on the noise source side. As described above, the auxiliary wall 6 according to this modification is a wall having a sound absorbing structure having a sound absorbing effect similarly to the rotating wall 4. Note that the auxiliary wall 6 may be a sound-insulating wall like the main body wall 1.

(Action / Effect)
In the soundproof wall of the present invention, the rotating part is disposed above the main body wall. The rotating unit includes a rotating shaft that can rotate about the length direction of the main body wall, and a rotating wall attached to the rotating shaft. According to this configuration, when the soundproof wall receives a wind load, the rotating portion rotates to reduce the wind load acting on the soundproof wall. Therefore, the height of the soundproof wall can be increased to a height that cannot be realized by a conventional upright soundproof wall / branch-type soundproof wall (the height of the soundproof wall can be increased). The rotating wall constituting the rotating part is attached to the rotating shaft so as to extend from the rotating shaft in the radial direction of the rotating shaft. As described above, since the rotary wall is attached to the rotary shaft so as to extend in the radial direction of the rotary shaft, the soundproof wall according to the present invention has a sound source (noise The diffraction effect of the sound from the source to the observation point is increased, and the noise reduction effect is more than that of the conventional upright sound barrier. Furthermore, for example, when snow has accumulated on the rotating wall, the snow falls due to the rotation of the rotating wall due to the unbalance of the snow load. That is, the soundproof wall of the present invention has a structure in which rain, snow and the like are not easily collected.

  In addition, by making the rotating wall of the rotating part into a sound-absorbing structure wall, reflection of sound from the rotating wall in various directions can be suppressed, and noise is reduced compared to a sound-insulating structure wall without sound absorption The effect can be increased.

  Further, by arranging three or more rotating walls around the rotation axis with an equal phase difference, even if the rotating wall (rotating part) rotates and stops at an arbitrary angle, each angle is sufficient. Noise reduction effect can be obtained. In addition, if both surfaces of the rotating wall are sound absorbing surfaces, even if the rotating wall rotates, the ratio of the sound absorbing surfaces increases in the side view of the rotating part, which can increase the noise reduction effect and reduce noise at each angle. Variations in effects can be suppressed.

  For example, as described as a modification, a wind load is further reduced by providing a some rotation part as a structural member of a sound-proof wall. Therefore, the height of the entire soundproof wall can be further increased (the height dimension of the entire soundproof wall can be further increased). As a result, a greater noise reduction effect can be obtained.

  Further, by further arranging an upright auxiliary wall above the rotating part, the noise reduction effect can be increased also by this auxiliary wall. Since the wind load is reduced by the rotating portion, it is possible to satisfy the wind resistant design even if an auxiliary wall is arranged.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

1: Body wall 2: Rotating part 3: Rotating shaft 4: Rotating wall 4a: Sound absorbing surface 4b: Sound insulating surface 100: Sound insulating wall D: Length direction of the body wall

Claims (5)

The body wall,
A rotating part disposed on the body wall;
Have
The rotating part is
A rotating shaft rotatable around the length direction of the main body wall;
A rotating wall attached to the rotating shaft so as to extend from the rotating shaft in a radial direction of the rotating shaft;
Equipped with a,
A soundproof wall characterized in that three or more rotating walls are arranged with an equal phase difference around the rotating shaft . The soundproof wall according to claim 1,
A soundproof wall, wherein the rotating wall is a sound absorbing wall. The soundproof wall according to claim 1 or 2 ,
A soundproof wall characterized in that both surfaces of the rotating wall in the direction in which the rotating wall rotates are sound absorbing surfaces. In the soundproof wall in any one of Claims 1-3 ,
A soundproof wall, wherein a plurality of the rotating parts are arranged. In the soundproof wall in any one of Claims 1-4 ,
A soundproof wall, wherein an upright auxiliary wall is disposed above the rotating part.

Images