JP3616623B2 - Noise barrier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a noise blocking wall that prevents noise generated on a roadway or the like from being transmitted to the outside as much as possible.
[0002]
[Prior art]
In order to prevent as much as possible the noise generated by the automobile from traveling to a private house outside the roadway, noise blocking walls are often provided along the road.
FIG. 3 is a view showing an example of such a conventional noise shielding wall. In FIG. 3, 1 is a noise blocking wall, 2 is a noise blocking wall body, and 3 is a noise blocking wall upper part. The noise blocking wall 1 is provided along the road on the road. As shown in parentheses in FIG. 3, the near side from the noise blocking wall 1 is inside the roadway, and the other side is outside the roadway.
[0003]
In the case of this example, the noise blocking wall 1 is composed of a noise blocking wall main body 2 installed vertically from the ground and a noise blocking wall upper part 3 formed on the noise blocking wall main body 2. And the noise shielding wall upper part 3 is made into the shape curved inside (roadway inner side).
The noise generated in the roadway is reflected on the noise barrier wall body 2 or reflected on the upper part 3 of the noise barrier wall, and is prevented from going out of the roadway. The noise blocking wall upper part 3 prevents noise from going out obliquely upward, but is curved inward so that it is blocked compared to a shape that extends vertically upward. The defense range to be widened.
[0004]
[Problems to be solved by the invention]
(problem)
However, the conventional noise blocking wall described above adds noise reflected from the wall to the generated noise to fill the roadway and further increase the noise in the roadway, so the efficiency of blocking the noise is poor. There was a problem.
[0005]
(Explanation of problem)
(1) Sound generated in the roadway is reflected by the noise barrier 1 and stays in the roadway, so the roadway is filled with newly generated noise and reflected noise. It becomes. Of that noise, the part that goes diagonally above the noise barrier wall upper part 3 goes outside the noise barrier wall upper part 3, but the noise itself is large, The amount of heading upward is also large.
[0006]
{Circle around (2)} Although the noise blocking wall 1 reflects the impacted noise, the noise blocking wall 1 itself vibrates to a slight extent due to the impact force of the noise sound wave. The vibration of the noise blocking wall 1 is a vibration with a resonance frequency determined by its size (the height of the noise blocking wall body 2 and the curved length of the upper portion 3 of the noise blocking wall). Of course, the noise is transmitted to the outside (the outside of the roadway) from the noise blocking wall 1. The sound becomes louder as the road is filled with noise.
An object of the present invention is to solve the above problems.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, in the noise barrier wall of the present invention, the noise barrier wall body installed perpendicular to the ground and the upper part of the noise barrier wall body are spiral in cross section, and the external open part is the noise. The structure is provided with a noise absorbing device installed facing the generation side.
[0008]
(Work)
The noise absorbing device installed at the upper part of the noise barrier wall body absorbs a part of the incoming noise and makes the reflected sound small even if it is reflected. For this reason, the noise filling the roadway is reduced as compared with the prior art, so that the noise that goes over the noise barrier is reduced, and the sound transmitted to the outside is also reduced by vibrating the noise barrier.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing a noise blocking wall according to the present invention. Reference numerals correspond to those in FIG. 3, and 4 is a noise absorbing device. 3 differs from the conventional example of FIG. 3 in that a noise absorbing device 4 having a special shape is attached instead of the noise blocking wall upper portion 3 curved inward along the upper portion of the noise blocking wall body 2. is there.
FIG. 2 is a view showing a cross section of the noise absorbing device 4. The cross section of the noise absorbing device 4 has a spiral shape that has been swirled as many times as necessary, and the external open part 4-1 is arranged so as to face the inner side of the roadway on which noise is generated.
[0010]
The noise generated on the roadway enters from the external opening 4-1 as indicated by the arrow of the approach sound 5. The noise travels back in the spiral path. As you go deeper, the loudness is also reduced. After going to the back, it tries to come out as shown by the arrow of the reflected sound 6. Therefore, both of them collide in the middle of the spiral path of the noise absorbing device 4. When they hit, if both sound waves are different by half a wavelength (that is, one sound wave is in a “mountain” state and the other is in a “valley” state), they cancel each other Noise disappears.
Needless to say, the noise on the roadway includes sound waves of various wavelengths, but somewhere in the spiral path of the noise absorbing device 4, the incoming sound 5 and the reflected sound 6 are different by a half wavelength. All the sound of the wavelength will be extinguished. Therefore, when viewed from the outside, the noise absorbing device 4 is a device that absorbs noise. There is also a reflected sound that does not disappear inside but exits from the external open part 4-1, but since the energy is consumed by reflection in the middle, it is considerably reduced in size.
[0011]
As shown in FIG. 1, the noise blocking wall 1 of the present invention is provided with the noise absorbing device 4 as described above along the upper portion of the noise blocking wall main body 2 similar to the conventional one. The wall body 2 reflects the noise generated in the roadway and prevents it from being transmitted outside the roadway as in the conventional case. Of the noise generated in the roadway, the portion that enters the noise absorbing device 4 obliquely upward is absorbed, or even if reflected sound comes out, it is supposed to be small by the reciprocation of the spiral path. .
[0012]
Therefore, the noise reflected in the roadway is not large as in the case of the conventional noise blocking wall, and the noise filling the roadway is also smaller than before. Therefore, the noise that goes out above the noise absorbing device 4 is reduced, the sound that vibrates the noise blocking wall 1 itself is weakened, and the efficiency of blocking the noise is improved as compared with the conventional case.
In the above example, the case where it is used as a noise blocking wall installed along a roadway has been described, but nothing is limited thereto. It can be used as a wall to prevent noise from being transmitted to the outside from some noise source. For example, it can be used as a noise blocking wall installed along the site of a factory.
[0013]
【The invention's effect】
As described above, according to the present invention, the noise absorbing device installed on the upper part of the noise blocking wall main body absorbs a part of the noise entering there and reduces the reflected sound even if reflected. Therefore, the noise filling the roadway is reduced as compared with the conventional case. Therefore, the noise that goes over the noise blocking wall is reduced, and the sound transmitted to the outside is reduced by vibrating the noise blocking wall. As a result, the efficiency of blocking noise transmitted to the outside is improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a noise blocking wall according to the present invention. FIG. 2 is a sectional view of a noise absorbing device. FIG. 3 is a diagram showing an example of a conventional noise blocking wall.
DESCRIPTION OF SYMBOLS 1 ... Noise-blocking wall, 2 ... Noise-blocking wall main body, 3 ... Noise-blocking wall upper part, 4 ... Noise-absorbing device, 4-1 ... External opening part, 5 ... Approaching sound, 6 ... Reflected sound

Claims (1)

A noise barrier wall installed vertically from the ground;
A noise blocking wall comprising: a noise absorbing device installed along the upper part of the noise blocking wall main body, having a spiral cross section and having an external open portion directed toward the noise generating side.

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