JP2005163334A - Soundproof device and soundproof wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an excellent noise-reducing effect by using a miniaturized device. <P>SOLUTION: In an opening space structure 5, many space parts 51, which are opened on the side of a sound source and whose opposite-side terminal ends are closed, are vertically and horizontally provided in rows, and the depth dimension of a space part 51a arranged in an upper-end row is set smaller than that of a space part 51b arranged in a lower row. The structure 5 is arranged in the front of the next sound-absorbing structure 2. The structure 2, which is formed in such an approximate triangle as to be directed to a back end 24 on the opposite side from a front part 23, is composed of a top surface part 21 for covering a top surface, an undersurface part 22 for covering an undersurface, and the front part 23 which is directed to the side of the sound source. The top surface 21 is formed of a sound-absorbing material, and a plurality of internal spaces 3 and 3 (three spaces in Fig.), such that their depths are sequentially made smaller toward the back end 24 from the front part 23, are provided inside by using a plurality of almost vertically arranged partition plates 31 (two plates in Fig.). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a soundproofing device installed to reduce noise in roads, railways, factories, and the like, and a soundproofing wall using the soundproofing device.

2. Description of the Related Art Conventionally, as a measure for preventing noise generated from roads, railways, factories, etc., it is widely used to install a soundproof wall in order to block noise transmitted from a noise generating source. Sound barriers for this purpose are generally installed by placing a sound insulating plate or a sound insulating plate with a sound absorbing material (or a sound insulating plate with a built-in sound absorbing material) between the H-shaped support columns. The height of the wall needed to be increased to improve the effect.
However, if the height of the soundproof wall is increased, the cost is increased, and inconveniences such as sunshine, landscape, ventilation, or radio interference may occur.

Therefore, a cylindrical sound-absorbing material or the like is installed horizontally along the wall at the upper end of the sound barrier (see Patent Document 1), or a V-shaped wall is added (see Patent Document 2). There has been proposed a soundproof wall that improves the noise reduction effect (soundproof effect) without increasing the height so much.
In addition, a soundproof wall in which an apparatus having a structure (see Patent Document 3) in which an upper opening such as a V shape is covered with a sound absorbing material has been proposed.

However, in the case of a cylindrical sound absorbing material, it is difficult to increase the size in order to increase the noise reduction effect in terms of cost, strength, and structure, and in the case of a V-shaped wall, in order to increase the noise reduction effect The size has to be increased, resulting in high costs and wind pressure strength after installation. In addition, the soundproof wall provided with a cylindrical sound absorbing material or a V-shaped wall has a problem that the noise reduction effect at a relatively high position (high place) is small.
Japanese Patent Laid-Open No. 7-180119: FIG. JP-A-9-264909: FIG. Japanese Patent Laid-Open No. 2002-161516: FIG.

  The present invention has been made to solve the above-described problems of the soundproofing device, and an object of the present invention is to provide a soundproofing device and a soundproofing wall that can obtain a higher noise reduction effect with a smaller device.

  The above problem is a soundproofing device installed at the upper part of the soundproofing wall, which is provided with a sound absorbing material on the upper surface, and is open on the sound source side front surface of the sound absorbing material structure having a plurality of internal spaces, and opens on the opposite side. A book in which a large number of closed spaces are arranged, and an open space structure in which the depth of the spaces arranged in the upper end row is shorter than the space in the lower row is arranged. This can be solved by the soundproofing device of the invention.

In the present invention, the cross-sectional shape of the sound absorbing structure is a tapered, generally triangular shape whose width is reduced from the sound source side toward the rear, or the space portion arranged in the upper end row of the open space structure. A form in which the depth length is 1/2 to 1/4 of the space portion of the lower row is preferable.
The above problem can also be solved by the soundproof wall of the present invention characterized in that the soundproofing device is installed in the upper part.

  Since the soundproofing device and the soundproofing wall of the present invention are configured by combining the open space structure on the front surface of the sound absorbing structure as described above, the excellent effect that the noise reduction effect can be further improved as follows. There is. Therefore, the present invention has extremely great practical value as a soundproofing device and a soundproofing wall that have solved the conventional problems.

(1) A soundproof wall provided with the soundproofing device of the present invention is a soundproofing structure in which noise generated from a sound source and over the soundproofing device is silenced by an open space structure having an opening in the front portion of the soundproofing device, and a sound absorbing structure. Since the silencing is performed continuously or simultaneously, a great noise reduction effect can be obtained by a synergistic effect.
(2) The noise reduction effect is greater than that of a conventional soundproofing device of the same size. Moreover, if the noise reduction effect is the same, the size of the soundproofing device can be further reduced, so that the cost of the soundproofing device can be reduced.

Next, embodiments of the soundproofing device and the soundproofing wall of the present invention will be described with reference to FIGS.
The soundproofing device of the present invention will be described. In FIG. 1 illustrating the soundproofing device, an opening space structure 5 is combined with the front surface of the sound absorbing structure 2 as will be described in detail later.

(Sound absorbing structure)
The sound absorbing structure 2 according to the present invention includes an upper surface portion 21 that covers the upper surface, a lower surface portion 22 that covers the lower surface, and a front surface portion 23 that faces the sound source side. The front surface portion 23 faces the rear end 24 on the opposite side. A triangular shape is formed, and a side surface portion 26 is provided on the side surface.

And this upper surface part 21 is formed with a sound-absorbing material, and the depth is sequentially increased from the front surface part 23 toward the rear end part 24 by a plurality of partition plates 31 (two in the figure) arranged substantially vertically. A plurality of shallow internal spaces 3 and 3 (three in FIG. 1) are provided. In addition, on both sides, mounting portions 25 that are attached to the H-shaped support column 11 (see FIG. 4) for mounting the sound insulating plate 10 to be erected are provided in mounting step portions 27, but in FIG. It is omitted.
4 is a structure in which the front of the H-shaped support 11 is a space, so that the H-shaped support can be seen when viewed from the sound source side. However, an appropriate H-shaped support covering is provided to make the structure invisible. May be.

Further, the sound absorbing structure 2 will be described in detail.
The sound absorbing structure 2 is a box-shaped structure having an internal space 3 partitioned by a partition plate 31, and is preferably a metal, inorganic or organic porous sound absorbing material as a sound absorbing material forming the upper surface portion 21 thereof. A sound absorbing material made of a material, a perforated material (a perforated material, a slit material, a net-like material), a transparent or non-transparent film-shaped sound absorbing material, or the like is used alone or in combination.

  The metal sound-absorbing material is made of a porous sound-absorbing material obtained by crimping aluminum fibers alone or in combination with a net or a perforated plate, a porous sound-absorbing material obtained by sintering aluminum powder, an aluminum foam, etc. It is good to use as. By using such a sound-absorbing material, it is possible to expect a sound-absorbing effect, and it is possible to prevent the expected performance from being deteriorated due to the accumulation of fallen leaves and snow accumulation. Corrosion and deterioration can be prevented.

  In addition, the sound absorbing material may be attached flatly on the upper surface portion 21 of the sound absorbing structure 2, but may be attached in a semicircular shape so that the central portion is raised. Increasing the central portion has the advantage that dirt, dust, fallen leaves, snow, etc. are difficult to accumulate, and that it is easy to remove and wash due to rain. In addition, the upper surface portion 21 made of the sound absorbing material is disposed on the entire upper surface of the sound absorbing structure 2 and may be partially installed. The sound absorbing material forming the upper surface portion 21 is preferably extended to the upper surface of the open space structure 5 disposed on the front surface (see FIG. 2).

  Next, the internal space 3 provided in the sound absorbing structure 2 will be described. Inside, a plurality of rows of space spaces 3 and 3 are arranged in the length direction and the height direction by a plurality of partition plates 31 arranged substantially vertically. Provided. Further, the partition interval (width and length of the internal space 3) may be equal intervals or unequal intervals. When the cross-sectional shape is a triangle, the depth (width in the vertical direction) of the internal space 3 is 0.4 to 0.7 m near the front surface (road side), and the depth is the rear end 24. It is preferable to change the direction so that it continuously decreases.

  The depth of the space provided in this way (distance from the top sound-absorbing material to the bottom sound-insulating material) is ¼ of the wavelength in the frequency region 125 Hz to 4000 Hz of road and railway noise (about 0.68 m at 125 Hz, 4000 Hz) in each part. Therefore, the noise attenuated in the vicinity of the open space structure, which will be described later, can be greatly reduced by the sound absorbing effect that the sound absorbing structure 2 further absorbs the sound. When the depth of the front side space (height near the mounting portion of the soundproofing device) is made to coincide with the height dimension (for example, 500 mm) of the conventional soundproofing plate (soundproofing plate 10 in FIG. 4), This is convenient when the sound insulation plate is removed and replaced with the soundproofing device of the present invention.

  The partition plates 31 that partition the internal space 3 are arranged substantially parallel to the vertical axis of the sound insulation wall, but the partition plates are arranged in a plurality of rows from the front side toward the rear end, so that each tip is It contributes to the reduction of noise that goes over the top of the soundproofing device as a diffraction edge of noise.

  The partition plate 31 and the materials such as the lower surface portion 22, the front surface portion 23, and the side surface portion 26 are made of a metal material such as an iron plate or an aluminum plate, or an organic material such as a synthetic resin, but is not limited thereto. In addition, when a transparent (light-transmitting) material is used, the soundproof wall can have transparency and translucency, so that the scenery, sunlight, and daylighting are improved. If the opening space structure 5 is made transparent (translucent) in combination with a transparent thin-film sound-absorbing material, the entire sound-proofing device 2 (translucent) can be obtained.

(Open space structure)
Next, the open space structure 5 provided on the front surface of the sound absorbing structure 2 described above will be described.
The open space structure 5 includes a large number of space portions 51 that are open on the side of the sound absorption source and closed at the opposite end, arranged in the vertical and horizontal directions, and the depth length of the space portions 51a arranged in the upper end row is set at the lower level. It is configured to be shorter than the row of space portions 51 b and is disposed on the front surface of the sound absorbing structure 2.

  More specifically, the open space structure 5 is composed of space portions 51a and 51b obtained by partitioning the outer frame portion 52 with partition plates 53a and 53b. The sound source side is open and the opposite side is closed. It has been. Noise passing through the vicinity of the opening configured as described above can be reduced by phase inversion, resonance, and interference.

  The shape of the opening cross section is not limited to the illustrated quadrangle, and a triangle, a polygon, a circle, an ellipse, and the like can be applied. Various shapes may be combined, but a quadrangle is preferable from the viewpoint of manufacturing the device and cost.

As for the size of this opening (in the case of a square), the width when viewed from the front is preferably 0.05 to 2 m and the height is preferably 0.025 to 0.2 m, more preferably 0.1 m in length and 0. It is about 1 m.
It is not necessary to arrange all the openings to the same size, and openings having different sizes may be mixed. Acoustically, the opening at the upper end that becomes the boundary of the noise path is important. The upper end opening is an ideal opening of about 0.1 m in length and about 0.1 m in width, and the lower row is about 0.1 m in length. Even if the opening is wide in the horizontal direction of about 0.5 m to 1.8 m, a noise reduction effect substantially equivalent to that of the soundproofing device in which the entire opening is 0.1 m in length and 0.1 m in width can be obtained. With such a configuration, the number of partitions in the vertical direction of the lower row can be reduced, and the manufacturing cost of the apparatus can be greatly reduced.

  The depth (depth length) is 0.05 to 0.2 m, and preferably includes a length corresponding to ¼ (λ / 4) of the wavelength of the target noise. For example, 500 Hz: about 0.17 m, 1000 Hz: about 0.085 m, 2000 Hz: about 0.043 m.

  Moreover, it is preferable to mix the openings 5 having different depths because the frequency range is expanded. For example, if the depth of the opening in the upper row is about 1/2 to 1/4 of that in the lower row, it is possible to handle frequencies up to about 2 to 4 times the corresponding frequency depending on the depth of the opening in the lower row. Noise reduction effect is improved compared with the depth.

The material which comprises the opening space structure 5 demonstrated above is not specifically limited, such as a metal material and an organic material. When a transparent material is used, the soundproof wall can have transparency and translucency, so that the scenery, sunlight, and daylighting are improved.
The front ends of the partition plates 53a and 53b at the opening end of the opening 51 serve as noise diffraction edges and contribute to the reduction of noise that passes over the front surface of the soundproofing device. A thin film material that transmits sound waves may be attached to the opening end.

(Overall structure of soundproofing device)
In the soundproofing device of the present invention described above, it is preferable from the viewpoint of performance that the cross-sectional shape is a substantially triangular shape, but a trapezoidal shape or a rectangular shape can also be adopted.
The size of the soundproofing device is 0.5 m to 2 m in length (depth), and the effect improves as the length increases, but there is a practical limit, and 0.5 to 0.8 m is preferable. In addition, since the low frequency component is less likely to be attenuated, the length may be appropriately selected from the target noise frequency component, the noise reduction target value, and the like.

The width is preferably 1 m to 4 m, which is about the distance between the sound insulation wall H-shaped columns (H-shaped column 11 in FIG. 4), and the height is 0.5 m to 0.6 m, so that the height of the conventional sound insulation plate is adjusted. .
Moreover, although the part of the opening space structure 5 is 0.05-0.2 m among full length (depth), this is selected from the frequency component (wavelength) etc. of the noise made into object.

  Attachment portions for attaching the soundproofing device to the soundproofing wall H-shaped support are provided at both ends of the soundproofing device as illustrated in FIG. Or you may provide in the lower part of an apparatus. In this case, what is necessary is just to make it attach to the upper end of the sound-insulating wall H-shaped support | pillar with a bolt nut through a metal fitting. In addition, it is recommended that safety be considered so that the soundproofing device is provided with a wire rope (not shown) for preventing the fall.

(Mounting on sound insulation wall)
In the soundproofing device described above, the sound absorbing structure 2 is provided on the upper part of the soundproofing wall constructed of a sound insulating board or the like shown in FIG. The soundproof wall of the present invention is configured by projecting and attaching to the outside of the soundproof wall (for example, the outside of the road = the private side).
At the time of attachment, the soundproofing device is lifted by a crane or the like, and if there are attachment portions at both ends, they are dropped while sliding into the grooves of the H-shaped support columns, and fixed metal fittings are driven into the gaps and fixed.

  In this case, a hole may be provided in the attachment portion and a fall prevention wire rope may be passed through the hole in order to prevent the fall in case of accidental damage. Further, a wire rope may be attached to the upper end of the apparatus in the lateral direction and fixed to the H-shaped support. The soundproofing device may be attached to the upper part of the H-shaped support via a mounting bracket or directly fixed with a bolt or the like.

As shown in FIG. 2, the angle of attachment of the soundproofing device is preferably such that the upper surface of the soundproofing device is attached at an inclination angle θ of 60 ° to 90 ° with respect to the vertical axis of the sound insulating wall.
It was confirmed that when the mounting inclination angle θ is smaller than 90 °, the noise reduction effect is improved at a position about 10 m higher than the height of the noise source outside the soundproof wall. For example, when the mounting inclination angle θ is 60 to 80 °, the noise reduction effect is improved by 1 to 2 dB compared to the inclination angle 90 °. However, if the inclination angle is too small, the height of the soundproof wall itself increases, and the sunlight and the landscape are obstructed. Therefore, the selection is made comprehensively according to the situation.

  As described above, the soundproof wall using the soundproofing device of the present invention has the open space structure 5 disposed on the front surface of the soundproofing device in which the noise from the sound source is placed on the front surface and the upper part of the soundproof wall. Since the sound is silenced by phase inversion, resonance, and interference in a large number of spaces, and then silenced mainly by sound absorption in the sound absorbing structure 2, a greater noise reduction effect can be obtained.

(Soundproof device, Example 1)
The overall size of the soundproofing device is 2m in width, 0.6m in height, 0.6m in length, the opening shape of the open space structure is rectangular, 4 rows in the height direction (5 space rows), in the width direction Dividing into 3 rows (number of space rows 4), the depth of the lower 4 rows space is about 0.15 m, and the space of the uppermost row is set at the opening end 0.1 m from the opening end of the lower row The space portions with a depth of about 0.05 m are arranged, and the sound absorbing structure has a substantially triangular cross section and the depth of the space decreases toward the tip of the rear end portion. An aluminum porous sound absorbing material having a thickness of about 2 mm was attached to the upper surface portion.
In this soundproofing device, the mounting angle (tilt angle) with respect to the sound insulation wall was set to 70 degrees.

(Soundproof device, example 2)
The mounting structure (tilt angle) was 90 degrees with the same structure as in Example 1.

  A metal sound insulation board with a glass wool sound absorbing material built in between a H-shaped column with a height of about 3 m and standing on a flat surface at an interval of about 2 m (height 0.5 m, thickness 95 mm, width 2 m) ) The height of the soundproofing device (Example 1 or Example 2) of the present invention is attached to the upper part of the sound insulation wall having a built-in height of about 2.5 m by fitting five pieces to the flange of the H-shaped column. A soundproof wall b of about 3 m was formed. (Figure 3)

The total length of the soundproof wall was about 20 m, noise was generated from a noise source a provided near the ground as shown in FIG. 3, and the noise was measured at a measurement position c1 on the opposite side of the soundproof wall b.
As a result, the noise barrier of the present invention was found to have an effect of reducing 5 to 7 dB noise as compared with a noise barrier made of a metal sound insulating board having a glass wool sound absorbing material built in for all 3 m in height.
It should be noted that at the measurement position c2 where the ground height H is about 10 m, the effect of Example 1 was greatly reduced by 1 to 2 dB compared to Example 2 (inclination angle: example of 90 degrees).

Next, as a soundproofing device, the sound absorbing effect of the soundproofing device of the present invention was compared with the case where the soundproofing device was composed only of the sound absorbing structure and the case of the soundproofing device of the present invention. The results are shown in Table 1.
In the case of the soundproofing device of the present invention having a triangular cross section, a height of 0.6 m, and a length of 0.6 m, the noise reduction effect (difference from the conventional soundproofing wall of the same height without the soundproofing device installed) Is an average of 6 dB, a noise reduction effect of 3 dB when constituted only by a sound absorbing structure, and a noise reduction effect of 2 dB when constituted only by an open space structure having an opening, which is a significant reduction in the present invention. The effect was recognized. When this result is converted into the length of the soundproofing device, it corresponds to a size of about 1 m in the case of only the sound absorbing structure, and corresponds to a size of about 1.2 m in the case of only the open space structure. Therefore, the soundproofing device of the present invention has a special advantage that the length can be reduced by 50 to 60% compared to the conventional type.

The part notch principal part perspective view for demonstrating the soundproofing apparatus of this invention. The schematic sectional drawing of the soundproof wall in an Example. The schematic diagram which shows the relationship between the sound source in an Example, a soundproof wall, and a measurement position. The partially cutaway perspective view which shows other embodiment of the soundproofing apparatus of this invention, and its attachment structure. The partially notched perspective view which shows other embodiment of the soundproofing apparatus of this invention.

Explanation of symbols

10: Sound insulating plate, 11: H-shaped support column 2: Sound absorbing structure, 20: Soundproofing device of prior application, 21: Upper surface part, 22: Lower surface part, 23: Front part, 24: Rear end part, 26: Side part 3 : Internal space, 31: Partition plate 5: Open space structure, 51, 51a, 51b: Space part

Claims (5)

  A soundproofing device installed on the top of a soundproofing wall, provided with a sound absorbing material on the upper surface, and a sound absorbing material structure having a plurality of internal spaces. A soundproofing device comprising an opening space structure in which a large number of sections are arranged and the depth of the space arranged in the upper end row is shorter than the space in the lower row.   The soundproofing device according to claim 1, wherein a cross-sectional shape of the soundproofing device is a tapered, generally triangular shape having a reduced width from the sound source side toward the rear.   The soundproofing device according to claim 1 or 2, wherein a depth length of the space portion arranged in the upper end row of the space structure is 1/2 to 1/4 of the space portion of the lower row.   The soundproofing device according to claim 1, wherein the horizontal width of the lower row space portion of the space structure is larger than that of the upper row space portion. The soundproof wall characterized by installing the soundproof device in any one of Claims 1-4 in the upper part.

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