JP3410297B2 - Soundproof panel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof panel installed so as to surround a low frequency sound source such as a sediment separating device.

[0002]

2. Description of the Related Art When excavating using a mud circulation type excavator such as a hydro phrase excavator or a muddy water shield machine,
The waste mud water generated by the excavation is reused as mud water after a predetermined treatment after separating the excavated sediment by the sediment separating device.

FIG. 6 is a front view showing an example of a conventional sediment separating apparatus. As can be seen in the figure, in the earth and sand separating device 10, screens 1, 3, 4 functioning as so-called vibrating screens and an iron plate 2 called a blind plate are attached to a frame body 5 supported by a spring 7, and the frame body The screens 1, 3 and 4 are vibrated by driving the exciter 6 mounted above the screen 5, and the soil on the screens 1, 3 and 4 can be selected according to the particle size.

Here, when the sediment separating apparatus 10 is operated,
Noise is generated from each part and the screens 1, 3,
4 becomes a sound wave generation surface, and low frequency sound of about 17 Hz is generated. Since such low-frequency sound is near the lower limit of the audible range that can be heard by the human ear, rattling noise caused by vibrating fittings such as shoji screens, windows, and doors is not a direct noise. Generate.

Therefore, when the earth and sand separating device is installed in an urban area to perform the earth and sand separating work, the whole earth and sand separating device 10 is covered with a soundproof box 11 as shown in FIG.
The noise from each part of the device and the low frequency sound generated by the vibration of the screen were designed to be leaked to the outside as little as possible.

[0006]

However, in the conventional soundproof box, the sound pressure level outside the soundproof box is lowered to some extent by the sound insulation performance proportional to the surface density of the soundproof panel and the sound absorption performance by glass wool or the like. However, for low frequency sound, the sound pressure level outside the soundproof box cannot be sufficiently lowered due to the lack of sound insulation and sound absorption performance of the soundproof panel in the frequency range. Was occurring.

In particular, the lack of sound absorption performance causes low frequency sound to reverberate inside the box, resulting in an increase in sound pressure level. In the worst case, the increase in sound pressure level due to reverberation is suppressed by the soundproof panel. However, the sound pressure level outside the box may not change much compared to when the soundproof box is not installed.

[0008] Due to such circumstances, in practice, even if the sediment separation efficiency is sacrificed, it is necessary to take measures such as lowering the rotational speed of the vibrator and lowering the amplitude of the screen.

On the other hand, if the soundproof panel is made of concrete or thick iron plate, for example, the areal density and rigidity of the panel are increased to improve the sound insulation performance for low frequency sound, and as a result, the sound pressure outside the soundproof box is increased. Although the level can be lowered sufficiently, in that case, another problem arises in that handling such as transportation, installation, removal and diversion becomes difficult, and the manufacturing cost becomes high.

The present invention has been made in consideration of the above-mentioned circumstances, and the sound pressure level of the low frequency sound outside the soundproof box is improved by improving the sound absorption performance of the low frequency sound while being easy to handle such as diversion. It is an object of the present invention to provide a soundproof panel capable of sufficiently reducing the noise.

[0011]

In order to achieve the above object, the soundproof panel of the present invention has the following features.
A hollow tube having one end closed and a predetermined sound absorbing port formed on the side of the other end is attached to a panel frame, an iron plate is arranged on one surface of the panel frame, and a perforated plate is formed on the other surface of the panel frame. While the sound absorbing port is attached to the perforated plate to penetrate, spacers are arranged at predetermined intervals in the gap between the perforated plate and the hollow tube, and the remaining space of the gap is filled with a porous sound absorbing material. is there.

In the soundproof panel according to the present invention, a plug for closing the space inside the hollow tube is movably arranged at one end of the hollow tube.

Further, in the soundproof panel according to the present invention, a hollow pipe having one end closed and a predetermined sound absorbing port formed on the side of the other end is attached to a panel frame, and the hollow pipes are alternated with the sound absorbing ports. They are arranged in parallel so that they are staggered.

Further, the soundproof panel according to the present invention corresponds to the length of the panel shortened by attaching a hollow tube having one end closed and a predetermined sound absorbing port formed on the side of the other end to the panel frame. By extending the extension pipe to the side opening of the hollow pipe to make the tip opening of the extension pipe a new sound-absorbing port, the sound-absorbing port projects a predetermined length in the out-of-plane direction of the panel frame. It was done.

Further, in the soundproof box according to the present invention, as described in claim 5, the soundproof panel according to any one of claims 1 to 4 is mutually arranged so as to be arranged around the earth and sand separating device. It is assembled and assembled.

[0016]

In the soundproof panel of the present invention, the hollow tube attached to the panel frame functions as a resonance type silencer using the sound absorbing port formed at the other end side as the air inlet and outlet, and the length of the hollow tube is increased. A sound wave having a wavelength corresponding to the height resonates in the hollow tube. Then, the energy of the air vibration that resonates in the hollow tube is changed into heat energy due to friction or the like when entering and leaving the sound absorbing port, and the vibration energy is quickly attenuated.

Therefore, the length of the hollow tube of the soundproof panel is set to, for example, a quarter wavelength of the target low frequency sound,
When the soundproof box is assembled with the panel so as to surround the low frequency sound source, the low frequency sound from the low frequency sound source is absorbed by the hollow tube, and reverberation in the soundproof box is prevented.

Here, when an iron plate is arranged on one surface of the panel frame, the iron plate is integrated with the hollow tube having a large bending rigidity to increase the rigidity, and the performance as a sound insulating material is improved.

A perforated plate is attached to the other surface of the panel frame to allow the sound absorbing port to penetrate the perforated plate, and spacers are arranged at predetermined intervals in the gap between the perforated plate and the hollow tube. When the remaining space of the gap is filled with the porous sound absorbing material, noise is absorbed by the porous plate and the porous sound absorbing material in addition to the sound absorbing effect of the low frequency sound by the hollow tube.

When a plug for closing the space in the hollow tube is movably arranged at one end of the hollow tube, the length of the tube is adjusted by changing the mounting position of the plug, and as a result, The resonance frequency is finely adjusted.

Further, when the hollow pipes are arranged in parallel so that the sound absorbing ports are alternately arranged in a staggered manner, the sound absorbing ports of the hollow pipes are dispersed on both edges of the panel, and the sound from the low frequency sound source is reduced. The frequency sound is efficiently absorbed by the hollow tube.

Further, when the sound absorbing port is protruded by a predetermined length in the out-of-plane direction of the panel frame, the shortage of the pipe length when the panel is shortened can be compensated by the protrusion length.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a soundproof panel according to the present invention will be described below with reference to the accompanying drawings. It should be noted that parts and the like which are substantially the same as those of the conventional technique are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a front view of a soundproof panel according to this embodiment. As can be seen from the figure, the soundproof panel 21 according to the present embodiment has a substantially rectangular shape as a whole, and the ratio of length to width is set to 2: 1 in consideration of versatility when assembled in a box shape.

As is clear from the detailed sectional view of FIG. 2A, the soundproof panel 21 has a large number of cylindrical hollow tubes 26 arranged in parallel in a panel frame 22 made of grooved steel. An iron plate 23 is provided on one surface of the panel frame 22,
A perforated plate 24 having a large number of holes 25 is attached to the other surface.

As can be seen from the detailed sectional views of FIGS. 2 (b) and 2 (c), the hollow tube 26 has one end of the pipe body 27 closed by a cap 28 and the other end of which is a T-shaped socket 29.
Is attached, the short tube 30 is attached to the opposite side, and it is closed with a cap 31. The side opening 37 of the T-shaped socket 29 penetrates the perforated plate 24, and acts as a sound absorbing port for allowing the hollow tube 26 to absorb low-frequency sound from that direction. Further, as can be seen clearly in FIG. 1, the hollow tubes 26 are arranged in parallel so that the side openings 37 of the T-shaped sockets 29 which are sound absorbing ports are alternately arranged in a staggered arrangement. The hollow tube 26 can be made of a lightweight material such as vinyl chloride, a lightweight steel tube, or a deck plate that is laminated.

On the other hand, on the opposite side to which the T-shaped socket 29 is attached, a cylindrical plug 34 having an outer diameter equal to the inner diameter of the hollow body 27 is fitted into the hollow body 27, and Bolt 3 passed through the perforated slit 35
6, the hollow tube 26 is fixed by loosening the bolt 36 and sliding the stopper 34 in the tube.
The length of the hollow portion can be changed by closing the inside of the housing at a desired position. Similar to the hollow tube 26, the plug 34 may be formed by covering both ends of a pipe made of vinyl chloride or the like with a cap, or may be made of a material such as wood or styrofoam.

In the gap between the hollow tube 26 and the perforated plate 24, spacers 32 are arranged at predetermined intervals, as can be seen clearly in FIG.
4, the hollow tube 26 and the iron plate 23 are joined together by bolts or the like so as to be integrated. In addition, in the remaining space of the gap, a porous sound absorbing material 33 such as glass wool or rock wool is used.
Is filled.

In the soundproof panel 21 of this embodiment,
The hollow tube 26 attached to the panel frame 22 functions as a resonance silencer using the sound absorbing port 37 provided at the other end side of the tube as an air inlet / outlet port, depending on the length of the hollow tube 26. The vibration of the sound wave resonates in the hollow tube 26. And
The energy of the air vibration that resonates in the hollow tube 26 is changed into heat energy due to friction and the like when entering and leaving the sound absorbing port 37, and the vibration energy is quickly attenuated.

Therefore, the length of the hollow tube 26 (the sound absorbing port 3
The distance from the plug 7 to the plug 34) is set to a quarter wavelength of the low frequency sound, and the soundproof panel 21 is built around the sound source with the sound absorbing port 37 facing the low frequency sound source. In the case of the soundproof box, the low-frequency sound from the low-frequency sound source resonates and is absorbed in the hollow tube 26, and the low-frequency sound reverberates in the soundproof box to increase its sound pressure level. There is no such thing.

In FIG. 3, two soundproof panels 21 are arranged on each side of the earth and sand separating device 10 which is a low-frequency sound source, for a total of five sides. It shows how it is assembled into a soundproof box by joining to. In addition, as an example of application to the sediment separating apparatus 10, the diameter of the hollow tube 26 is set to about 15 cm and the length of the pipeline is set in consideration of the size of the apparatus, the frequency of low-frequency sound generated, and the like. Is 5 m, the panel length is 6 m, and the panel width is about 3 m.

As described above, according to the soundproof panel 21 of the present embodiment, since the hollow pipe 26 arranged in the panel functions as a resonance type silencer, the low frequency sound generated from the sediment separating device or the like. Is efficiently absorbed by the hollow tube 26.

Therefore, when assembled in the soundproof box, the low frequency sound does not reverberate inside the box and the increase of the sound pressure level in the box due to the reverberation is suppressed. As a result, the low frequency sound outside the soundproof box is suppressed. The sound pressure level is
Significantly reduced compared to conventional soundproof boxes using soundproof panels.

Moreover, since such a hollow tube can be formed of a relatively lightweight material such as vinyl chloride, the weight of the entire panel is not much different from that of a conventional general soundproof panel and can be easily assembled and disassembled. It can be carried out. Therefore, there is no difficulty in transportation, installation, conversion, relocation, etc.

Further, according to the soundproof panel 21 of this embodiment, the iron plate 23 functioning as a sound insulating material is provided in the panel frame 2.
Since it is integrated with the hollow tube 26 having a high bending rigidity through the spacer 2 and the spacer 32, the rigidity of the iron plate 23 is also increased and the sound insulation performance is improved.

For general noise having a frequency higher than that of low frequency sound, the hollow pipe 2 is passed through the holes 25 of the perforated plate 24.
It is diffusely reflected by 6 and is absorbed by the porous sound absorbing material 33 filled with the porous plate 24.

Further, according to the soundproof panel 21 of the present embodiment, since the hollow tube 26 and the iron plate 23 have a triple sound insulation structure, the conventional sound absorber panel 21 has a porous sound absorbing material sandwiched between a pair of iron plates. The rigidity and surface density are higher than that of the soundproof panel, and the sound insulation performance is significantly improved, and the sound pressure level of the low frequency sound outside the soundproof box is significantly reduced in combination with the effect of improving the sound absorption characteristics of the low frequency sound described above. It becomes possible.

Noise having a frequency higher than the low frequency sound is also shielded by the triple sound insulation structure of the hollow tube 26 and the iron plate 23, and is absorbed by the perforated plate 24 and the porous sound absorbing material 33. The sound pressure level of noise is reduced as compared with the conventional one, and eventually it is possible to reduce the sound pressure level over a wide band including noise.

Further, since the plug 34 for closing the space in the hollow tube 26 is movably arranged at one end of the hollow tube 26, for example, when the vibration frequency of the earth and sand separating device changes, the plug is changed. By changing the mounting position of 34 and changing the length of the conduit, it is possible to adjust the resonance frequency.

Further, since the hollow pipes 26 are arranged in parallel so that the sound absorbing ports 37 are alternately arranged in a staggered manner, the sound absorbing ports 37 of the hollow pipe 26 are dispersed on both edges of the soundproof panel 21, and the earth and sand separating device, etc. The low frequency sound from can be efficiently absorbed.

In the present embodiment, the soundproof panel is assembled by installing two soundproof panels 21 on each of the five surfaces. However, the combination method and the scale thereof are arbitrary and are not limited. When the separating devices are collectively soundproofed, for example, as shown in FIG.
You may make it comprise with the soundproof panel 21 of one sheet. In such a case, the sound absorbing port 37 is arranged not only in the corner portion of the soundproof box but also in the central portion, so that efficient sound absorption is performed in the corner portion and the central portion where the sound pressure level of the low frequency sound is high. It becomes possible.

Further, in the present embodiment, the specific specifications of the soundproof panel are described for the convenience of understanding the invention. However, regarding the diameter and the number of the hollow tubes or the length of the pipes, the low frequency sound generation source is used. It can be appropriately changed in consideration of the scale, the frequency of the target low-frequency sound, the convenience of handling such as transportation, and the like. For example, the width of the soundproof panel is 2m for convenience of transportation.
The diameter and number of hollow tubes can be changed according to the degree.

Further, in the present embodiment, the length of the hollow pipe is made substantially equal to the length of the soundproof panel, but it is not always required to be the same, and even if a soundproof panel longer than the hollow pipe is used. Good. In such a case, it is preferable to provide a stopper to prevent the hollow pipe from rattling in the panel or to fit a pipe having a short length.

Although not particularly mentioned in the present embodiment, as shown in FIG. 5 (a), a door 51 for an operator to enter and exit is provided.
When the soundproof box is provided in the soundproof box, the soundproof panel 52 adjacent to the door 51 needs to be shorter than the soundproof panel 21 having a standard size by the space of the door.

In such a case, the extension pipe 53 corresponding to the shortened portion is added to the side opening 37 as shown in FIG. 5B, and the tip end opening 55 of the extension pipe 53 is newly replaced as a sound absorbing port. Good. In such a configuration, the sound absorbing port 55 protrudes from the perforated plate 24 by the length of the panel, but the length of the conduit is the same as that of the standard soundproof panel, and thus the soundproof panel 21 is the same. It is possible to obtain the sound absorption effect of.

Although not particularly mentioned in the present embodiment, if the soundproof panel or the hollow pipe of the present embodiment is arranged on the floor surface on which the earth and sand separating device is installed, the low frequency sound in the box can be reduced. The sound absorption performance of can be further improved.

Further, in this embodiment, a large number of hollow tubes are arranged in parallel in the panel frame, an iron plate is attached to one surface of the frame, and a perforated plate is attached to the other surface, and the hollow tube and the perforated plate are further connected. Although a porous sound absorbing material is filled in the space between them, in some cases, a configuration in which a large number of hollow tubes are arranged in the panel frame may be used. Even in such a configuration, the hollow tube is
It has the effect of suppressing the reverberation of low-frequency sound inside the box by acting as a resonance silencer as described above, and if the gap between the hollow tubes is filled with welding or resin, the hollow tubes will have It is possible to manufacture a soundproof panel that takes advantage of the high rigidity and high areal density. In addition, by adding an iron plate, a perforated plate, and a porous sound-absorbing material to the sound-proof panel with just such a hollow tube attached, a sound-proof panel with sound insulation properties and noise absorption properties gradually increased. It is also possible to manufacture and use these properly according to the application.

[0049]

As described above, since the soundproof panel of the present invention is constructed by attaching the hollow tube having one end closed and the predetermined sound absorbing port formed on the side of the other end to the panel frame, The sound absorption characteristic for high frequency sound is improved, and if this is assembled into a soundproof box, the sound pressure level of low frequency sound outside the soundproof box can be sufficiently reduced. Also,
Since such a soundproof panel can be formed of a light-weight hollow tube, it can be easily diverted, transported, or otherwise handled.

[0050]

[Brief description of drawings]

FIG. 1 is a front view of a soundproof panel according to the present embodiment.

FIG. 2 is a detailed view of the soundproof panel according to the present embodiment,
(a) is a sectional view taken along the line AA of FIG. 1, and (b) is the same as BB.
A sectional view taken along the line, (c) is a sectional view of the hollow tube, (d) is C of (c).
-A side view of the vicinity of the lower end of the hollow tube as viewed from the direction of the line C.

FIG. 3 is an overall view showing how a soundproof box is assembled using the soundproof panel of the present embodiment.

FIG. 4 is a general view of the soundproof box.

5A and 5B are views of a soundproof panel according to a modified example of the present embodiment, where FIG. 5A is an overall view of the soundproof box, and FIG. 5B is a perspective view of the soundproof panel.

FIG. 6 is a front view of a conventional sediment separating device.

FIG. 7 is an overall view of a conventional soundproof box.

[Explanation of symbols]

21,52 soundproof panel 23 Iron Plate 24 Perforated plate 26 hollow tubes 32 spacer 33 Porous sound absorbing material 34 Plug 37, 55 Sound absorption mouth

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masaaki Yoshizaki               2-3 Kandajimachi, Chiyoda-ku, Tokyo               Obayashi Corporation Tokyo Head Office                (56) Reference JP-A-7-302087 (JP, A)                 JP-A-4-125595 (JP, A)                 Actual Kaihei 6-65110 (JP, U)

Claims (5)

(57) [Claims] 1. A hollow pipe having one end closed and a predetermined sound absorbing port formed on the side of the other end is attached to a panel frame, and an iron plate is arranged on one surface of the panel frame and the other of the panel frame is mounted. A porous plate is attached to the surface of the porous plate to allow the sound absorbing port to penetrate through the porous plate, and spacers are arranged at predetermined intervals in the gap between the porous plate and the hollow tube to form a porous sound absorbing material in the remaining space of the gap. A soundproof panel characterized by being filled with. 2. The soundproof panel according to claim 1, wherein a plug body that closes a space inside the hollow tube is movably arranged at one end of the hollow tube. 3. A hollow pipe having one end closed and a predetermined sound absorbing port formed on the side of the other end is attached to a panel frame, and the hollow pipes are arranged in parallel so that the sound absorbing ports are alternately arranged in a staggered manner. Soundproof panel characterized by being placed. 4. A hollow pipe having one end closed and a predetermined sound absorbing port formed on the side of the other end is attached to a panel frame, and an extension pipe corresponding to the shortened panel is attached to the hollow pipe. A soundproof panel characterized in that the sound absorbing port is protruded in the out-of-plane direction of the panel frame by a predetermined length by connecting to the side opening to form a new sound absorbing port at the tip end opening of the extension pipe. . 5. A soundproof box, characterized in that the soundproof panel according to any one of claims 1 to 4 is assembled and bonded to each other so as to be arranged around the earth and sand separating device.