JPH041311A - Interference type sound proof device - Google Patents

Abstract

PURPOSE:To miniaturize a device and increase the sound-proof ability, by nearly vertically extending a hollow pierced pipe way along the sound-proof wall at the upper end of the sound source side thereof. CONSTITUTION:A sound-proof wall 2 is installed at the position apart from the noise source S. Next, hollow pierced pipe ways 5 are nearly vertically attached along the sound-proof wall 2 at the upper end of the noise source side 2a of the sound-proof wall 2. In this case, the hollow pierced pipe ways 5 are composed of a plurality of parallel ways to each other against the sound- proof wallface 2a and further the rows of hollow pierced pipe ways 5a near the sound-proof wall 2 are made longer than those of the further pipe ways 5b from the sound-proof wall in the length.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an interference type soundproofing device, and in particular to a device for delaying noise propagating from a noise source by passing a part of the noise through a hollow through pipe. The present invention relates to an interference type soundproofing device that forms a sound-attenuated interference region by causing the delayed propagation sound to interfere with the directly propagated sound from the noise source in combination with a soundproofing wall.

(Prior art) This type of interference type soundproofing device is known, for example, from Japanese Patent Publication No. 54200.
This is based on the interference principle described in Japanese Patent Publication No. 6 and Japanese Patent Publication No. 54-42728. In other words, by arranging an interference type soundproofing device having a large number of hollow pipes with its noise incident surface facing the noise source, a part of the noise propagating from the noise source is passed through the hollow pipes. This is based on the interference principle that creates a sound reduction area by using the phase difference between the delayed propagation sound emitted from the exit on the noise radiation surface and the directly propagation sound from the noise source. This device is capable of efficiently controlling the target noise frequency range by adjusting the pipe length, pipe cross-sectional area, and number of hollow pipes.

Unlike conventional soundproof walls, this interference type soundproofing device utilizes the above-mentioned interference phenomenon of propagated sound, so it has a large sound reduction and soundproofing effect, and has less sound diffraction phenomenon compared to soundproofing walls, so it can be used even over long distances. Great sound reduction effect. In addition, it is effective against noise sources that cannot be completely sealed, and has the advantage of allowing heat and air to pass through. In addition, it uses metal materials, inorganic materials, and plastic materials with excellent water and weather resistance. It has the advantage of being able to

For this reason, when using the above-mentioned interference-type soundproofing device to counter train noise generated by the running of railway vehicles such as Shinkansen trains or automobile running noise on expressways, it is necessary to install the interference-type soundproofing device on the noise source side of the existing soundproofing wall. By installing a soundproofing device, even with a low soundproofing wall in a narrow installation space, a sufficient sound reduction effect can be obtained at a sound receiving point far away from the soundproofing wall.

Based on the interference principle, for example, Japanese Patent Publication No. 59-19591
As shown in FIG. 9, the noise control device described in Publication No. 2 allows a portion of delayed propagation sound to be propagated to the side of the noise emission surface 1b of the noise control device 1 without being sufficiently interfered with by direct sound. , the sound reduction effect is not sufficient, so a sound insulating wall 4 is installed at an appropriate distance from the rear of the noise control device 1 as shown in FIG. 10 to prevent the propagation of uninterfered delayed propagation sound. I was going. However, in order to cope with the increase in noise caused by the speed increase of Shinkansen and other trains, improvements in soundproofing performance are required. Therefore, in the structure disclosed in the above-mentioned publication,
As a result of increasing the soundproofing performance, the noise control device becomes larger and costs increase, and when applied to Shinkansen trains, etc., it is installed at the upper end of the soundproofing wall, so the larger size causes problems such as air exclusive rights. is occurring.

(Problems to be Solved by the Invention) The present invention is intended to provide an interference-type soundproofing device that is compact and has excellent soundproofing performance, particularly suitable for countermeasures against noise caused by trains such as Shinkansen trains.

(Means for solving the problem) Therefore, according to the present invention, as shown in FIG. The interference type soundproofing device is characterized in that the hollow penetrating pipe 5 is provided at the upper end of the soundproofing wall on the noise source side so as to extend substantially perpendicularly along the soundproofing wall surface 2a.

Further, according to the present invention, the hollow through pipes 5 are provided in a plurality of rows parallel to the soundproof wall surface, and the length of the hollow through pipes in the row near the soundproof wall is longer than the length of the hollow through pipes in the row far from the soundproof wall. It is better to make it longer.

Further, it is preferable that the width of the hollow through conduit in a row close to the soundproof wall, that is, the dimension in the direction perpendicular to the soundproof wall, be larger than the width of the hollow through conduit in a row far away.

(Function) In the case of a Shinkansen, etc., among the noise that spreads to the outside from the noise source S between the track and the car body (wheels), the noise that propagates through the hollow pipe 5 is different from the noise that propagates directly. out of phase,
Thereby, the noise can be reduced by interference between the two noises. As shown in the schematic diagram in Figure 2,
Passage length L1 ÷ L2 of noise propagating through hollow pipe 5
The lower end position (XL Yl) is determined so that the length is longer than the path length L0 of directly propagated sound by % of the hollow pipe length. In this way, by making the path length of the propagating sound passing through the hollow pipe 5 interfere with the directly propagating sound by delaying each wavelength, the results of the visualization experiment of the single hollow pipe shown in Fig. 3 can be obtained. As can be seen, a significant sound attenuation zone is created compared to the case where the hollow pipe shown in FIG. 4 is not provided.

(Example) Figures 5 and 6 show an example of the present invention. The illustrated interference type soundproofing device 1 is made of synthetic resin or other similar materials;
A hollow penetrating pipe 5 is attached to the upper end of the noise source side 2a of the soundproof wall 2 installed at a position away from the noise source S so as to extend substantially vertically along the soundproof wall.

In this way, the hollow through pipes 5 having the upper end outlet are provided in a plurality of rows parallel to the soundproof wall surface 2a, and the length of the hollow through pipes 5a in the rows near the soundproof wall 2 is set to the length of the hollow through pipes 5a in the rows far from the soundproof wall 2. 5b
The width of the hollow through pipes 5a in the row near the soundproof wall, that is, the dimension in the direction perpendicular to the soundproof wall, is larger than the width of the hollow through pipes 5b in the row far away.

Figure 7 shows the case where the interference type soundproofing device according to the present invention is installed (
The results of a test comparing the sound reduction effect between I) and the case of soundproof walls (II) are shown in FIG. 8, and the measurement method thereof is shown in FIG. As shown in FIG. 8, the Shinkansen car body model 7 is installed, the noise source S is placed at the rail/wheel position of the Shinkansen car body model,
The horizontal distance d1 of the interference type soundproofing device I from the noise source S is 2.5.
The height (hl) from the noise source S to the upper end of the hollow body 1 is 2 m, and a point 25 m away from the soundproof wall 2 at a horizontal distance d2 is 2 m above the ground. The measurement was made at the sound receiving point P at the height (h2).

As shown in the graph of FIG. 7, the present invention can greatly improve the sound reduction effect compared to only soundproof walls.

(Effects of the Invention) According to the present invention, it is possible to install an interference type soundproofing device with a high sound reduction effect that can reliably reduce noise in a narrow space, and since the structure is simple, the soundproofing performance is improved. There is no increase in the shape, and construction equipment such as scaffolding is required if installed outside the soundproof wall, but since it is installed inside the soundproof wall,
Significant savings in construction equipment costs can be expected.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the device according to the present invention, Figure 2 is a diagram of the principle of the present invention, Figure 3 is a line diagram showing the results of a noise visualization experiment according to the present invention, and Figure 4 is visualization in the case of only a soundproof wall. Diagrams showing experimental results; FIG. 5 is a diagrammatic vertical sectional view showing one embodiment of the interference type soundproofing device according to the present invention; FIG. 6 is a diagrammatic front view of the device shown in FIG. 5; The figure is a characteristic curve diagram showing the sound reduction effect of the interference type soundproofing device according to the present invention. It is a schematic diagram of a conventional device. 1...Interference type soundproofing device 2...Soundproofing wall...Hollow pipe Figure 1 Figure 3 Figure 2 Figure 4 Figure 5 Figure 6 Figure 9 Figure 1 O Figure 7 Surrounding plate Number (Hz) Figure 8 Procedural Amendment Heisei Date

Claims (1)

[Claims] 1. In an interference type soundproofing device in which a hollow through pipe is provided on a soundproof wall installed at a position away from a noise source, the hollow through pipe is connected to the upper end of the soundproof wall on the noise source side. An interference-type soundproofing device characterized in that it is provided extending almost vertically along a soundproofing wall. 2. The hollow through pipes are provided in a plurality of rows parallel to the soundproof wall surface, and the length of the hollow through pipes in the row near the soundproof wall is longer than the length of the hollow through pipes in the row far from the soundproof wall. The interference type soundproofing device according to claim 1. 3. The interference according to claim 2, characterized in that the width of the hollow through conduit in a row close to the soundproof wall, that is, the dimension in the direction perpendicular to the soundproof wall, is larger than the width of the hollow through conduit in a row far away from the soundproof wall. Type soundproofing device.