JP2009139481A - Noise insulating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively insulate noise from a noise source which generates heat, with a simple configuration. <P>SOLUTION: The noise insulating device includes: a housing 3 for wrapping a device 2 which generates heat and sound; and a sound permeable film 4 and a sheet type sound absorbing material 5, which are separately arranged in the housing 3. The sound permeable film 4 and the sound absorbing material 5 are arranged to be perpendicular to a transmission direction of air transmission sound, and the sound permeable film 4 is arranged at an upper stream side of the sound absorbing material 5. The sound permeable film 4 is composed of a material which has characteristics for separating sound and heat, for example, a resin-made film etc. of a micron order thickness, such as a finely-woven fabric material, or a polyvinylidenechloride-based synthetic film, with a number of dense minute apertures. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a soundproofing device, and more particularly to a soundproofing device useful as a noise countermeasure for a device that generates heat together with noise.

  Conventionally, as this type of soundproofing device, (a) a transformer storage box that is installed in an electrical room and stores a transformer therein, and an air supply passage that supplies outdoor air to the lower part of the transformer storage box; An exhaust duct having one end connected to the upper part of the transformer storage box and the other end opened to the outside, (b) a plurality of plate-like projecting members inside the exhaust duct, By alternately projecting from the inner wall surfaces on both sides of the exhaust duct, a plurality of elbows are formed, and (c) the inner wall surface of the duct is provided with a large number of irregularities that are continuously connected to each other. It is known (see, for example, Patent Documents 1 to 3).

  However, in the soundproofing device (A), even if a sound absorbing material is attached to the inner wall of the exhaust duct, the sound absorbing material is in a positional relationship parallel to the air propagation direction. Therefore, noise cannot be effectively reduced, and since the sound absorbing effect is low, there is a problem that it is necessary to stick a sound absorbing material over the entire length of the duct. In addition, in the soundproofing device (b), the elbow shape allows the exhaust to be bent at a right angle so that the sound does not directly go outside, so noise can be effectively reduced, but a plurality of elbows must be formed. Therefore, there is a problem that a sufficient space cannot be secured. Furthermore, in the soundproofing device (c), in order to enhance the sound absorption effect within a limited range, it is necessary to have a complex uneven surface. In the soundproofing device provided with such an uneven surface, the air resistance is low. There is a problem that the cost increases due to the increase in size and the necessity of preparing a mold for forming irregularities.

  For this reason, a method of providing the sound absorbing material at a position orthogonal to the air propagation direction has been devised, but in this method, although the sound absorbing effect is improved as compared with the case where the sound absorbing material is provided parallel to the air propagation direction, Since the noise of the part flows together with air containing heat, there is a problem that it is not possible to sufficiently absorb sound with a simple configuration.

JP-A-11-283384 Japanese Patent Laid-Open No. 3-24398 JP-A-11-117761

  The present invention has been made paying attention to such points, and an object of the present invention is to provide a soundproofing device capable of efficiently soundproofing a noise source accompanied by heat generation with a simple configuration.

  A soundproofing device according to a first aspect of the present invention includes a housing that encloses a device that generates heat and sound, and an acoustically permeable membrane and a sheet-like sound absorbing material that are spaced apart in parallel in the housing. The sound transmission film and the sound absorbing material are disposed so as to be orthogonal to the propagation direction of the air propagation sound, and the sound transmission film is disposed on the upstream side of the sound absorbing material.

  According to a second aspect of the present invention, in the soundproofing device according to the first aspect, a mounting member for attaching an acoustically permeable membrane is disposed between the inner wall of the housing and the device.

  According to a third aspect of the present invention, in the soundproofing device according to the second aspect, the sound transmission membrane is attached to an opening provided in the mounting member so as to close the opening.

  According to a fourth aspect of the present invention, in the soundproofing device according to the second aspect or the third aspect, the sound absorbing material is attached to the inner wall of the housing facing the mounting member.

  According to a fifth aspect of the present invention, in the soundproofing device according to any one of the first to fourth aspects, an exhaust fan is disposed between the sound transmission film and the device.

  According to a sixth aspect of the present invention, in the soundproofing device according to any one of the first to fifth aspects, the sound transmission film is formed of a material having a property of separating sound and heat. It is.

  According to the soundproofing device of the first to sixth aspects of the present invention, the sound transmission film and the sound absorbing material are arranged so as to be orthogonal to the propagation direction of the air-borne sound, and the sound transmission film is located upstream of the sound absorbing material. By arranging it on the side, air propagation sound propagating with the exhaust airflow can be separated into sound and heat by the sound permeable membrane, and the separated sound is sound-absorbed by the sound absorbing material, and the separated heat is discharged to the exhaust port The noise source with heat generation can be efficiently soundproofed with a simple configuration.

  Hereinafter, a preferred embodiment to which the soundproofing device of the present invention is applied will be described in detail with reference to the drawings.

  1 is a perspective view of a sound absorbing box to which the soundproofing device of the present invention is applied, FIG. 2 is a front view of the sound absorbing box, and FIG. 3 is a schematic schematic sectional view of the sound absorbing box.

  1 to 3, a sound absorbing box 1 according to the present invention includes a rectangular parallelepiped housing 3 for enclosing a device 2 for generating heat and sound, for example, a vacuum pump, and the like in parallel in the housing 3 as will be described later. And a sound-transmitting film 4 (see FIG. 3) and a sheet-like sound absorbing material 5 (see FIG. 3). As indicated by the arrows, the sound transmission film 4 and the sound absorbing material 5 are disposed so as to be orthogonal to the propagation direction of the air-borne sound including heat, and the sound transmission film 4 is disposed on the upstream side of the sound absorbing material 5. ing.

  The housing 3 includes a lower box 31, an upper box 32 that covers the upper portion of the lower box 31, and a fan box 33 (see FIG. 2) provided at the lower portion of the upper box 32. Is provided with a shelf 310 (see FIG. 2) for mounting the device 2 such as a vacuum pump. A first mounting member 321 (see FIG. 3) made of a plate material is parallel to the upper plate 320 at a position spaced apart from the upper plate 320 (see FIG. 3) in the upper box 32 by a predetermined length toward the device 2. The second mounting member 322 (see FIG. 3) made of a plate material is located at a position spaced apart from the first mounting member 321 toward the device 2 by a predetermined length, and the first mounting member 321. Are arranged in parallel with each other. An opening 321a for attaching the sound transmission film is provided at a substantially central portion of the first mounting member 321, and a fan box 33 is provided at a substantially central portion of the second mounting member 322. . The fan box 33 is provided with, for example, four openings (not shown) for attaching the ventilation fan 330 so as to be separated by the first mounting member 321 and the second mounting member 322. The formed space (passage) 323 (see FIG. 3) communicates with an exhaust port 324 provided in the upper box 32. In this embodiment, an interval of about 50 mm is provided between the first mounting member 321 and the second mounting member 322.

  The sound transmission film 4 is made of a material having a property of separating sound and heat, that is, a material having a property of allowing sound to pass but not allowing air flow to pass through. Specifically, it is composed of a cloth material with clogs having many minute holes densely, a resin film having a thickness of micron order made of a polyvinylidene chloride synthetic film and the like.

  The sound transmission membrane 4 having such a configuration is attached to the opening 321a of the first mounting member 321 so as to close the opening 321a.

  The sound absorbing material 5 is a material that has excellent sound absorbing characteristics over a wide range from a low frequency region to a high frequency region, and also exhibits effective damping properties for reducing solid-borne sound and vibration, specifically, Is preferably a low-frequency sound-absorbing material obtained by laminating urethane foams having a thickness of 25 mm on both sides of a film made of silicone resin.

  The sound absorbing material 5 having such a configuration is attached to the inner wall of the upper plate 320 of the upper box 32. A space of about 5 mm is provided between the sound absorbing material 5 affixed to the inner wall of the upper plate 320 of the upper box 32 and the above-described acoustic transmission film 4, so that the above-described passage is formed above the upper box 32. An empty space 324 smaller than 323 is formed.

  According to the soundproofing device having such a configuration, since the sound transmission film 4 and the sheet-like sound absorbing material 5 are arranged in parallel and spaced apart from each other so as to be orthogonal to the propagation direction of the air-borne sound including heat, Air-propagating sound including heat, that is, air-propagating sound that propagates along with the exhaust airflow is separated into sound and heat by the sound transmission film 4, and the separated sound travels straight toward the sound-absorbing material 5 and hits the sound-absorbing material 5. The heat absorbed and separated is discharged from the exhaust port 324 via the passage 323. Therefore, according to the soundproofing device of the present invention, a noise source with heat generation can be efficiently soundproofed with a simple configuration.

  FIG. 4 shows a comparison of noise levels depending on the presence or absence of the sound transmission film of the soundproof box configured as described above. Here, in the comparative example, the vacuum pump 2 is housed in a conventional soundproof box having no sound permeable membrane, that is, a soundproof box 1 having a width of 600 mm, a depth of 1000 mm, and a height of 1200 mm. The noise level of the member 322 with an exhaust fan 330 with a heat dissipation amount of 2400 W attached and the sound absorbing material 5 formed by laminating a 25 mm thick urethane foam on both sides of the silicone resin film on the upper plate of the upper box 32 is set. In the illustrated embodiment, a vacuum pump is housed in a soundproof box according to the present invention in which a sound transmission membrane 4 is disposed, that is, a soundproof box 1 having a width of 600 mm, a depth of 1000 mm, and a height of 1200 mm. An exhaust fan 330 having a heat dissipation amount of 2400 W is attached to the mounting member 322, and the above-mentioned polyvinylidene chloride is attached to the first mounting member 321. The sound level of a sound absorbing material 5 made of a synthetic film and a sound absorbing material 5 formed by laminating a 25 mm thick urethane foam on both sides of a silicone resin film on the upper plate of the upper box 32 is shown. Yes. The noise level was measured in accordance with JIS A 1409: 1998 “Measurement method of sound absorption coefficient of reverberation room method”.

  From the figure, the soundproof box in the present embodiment has a dominant difference of about 6.8 (dB) in the all-pass noise level (dB) with respect to the comparative example, and is about 9.5 at the 160 Hz noise level (dB). It can be seen that (dB) is superior, and that the soundproof box according to the present invention is very effective as a noise prevention measure.

  In the above-described embodiments, the present invention is described with specific embodiments shown in the drawings. However, the present invention is not limited to these embodiments, and as long as the effects of the present invention are exhibited, You may comprise as follows.

  First, in the above-described embodiment, the sound absorbing box has been described. However, the same effects can be obtained when applied to equipment such as ducts and fans, the construction field, and the like.

  Secondly, in the above-described embodiment, a case where a low-frequency sound absorbing material formed by laminating urethane foams having a thickness of 25 mm on both surfaces of a resin film made of a silicone resin is used as the sound absorbing material. You may use what laminated | stacked porous body layers, such as glass wool and rock wool of thickness 25mm, on both surfaces of the resin film which consists of silicone resins. Further, a resin film made of acrylic resin may be used instead of the resin film made of silicone resin.

The perspective view of the soundproofing device in the Example of this invention. The front view of the soundproofing apparatus in the Example of this invention. The schematic sectional drawing of the soundproofing apparatus in the Example of this invention. Explanatory drawing which shows the comparison of the noise level by the presence or absence of the sound permeable film of a soundproof box.

Explanation of symbols

2 ... Device for generating heat and sound 3 ... Housing
320: upper plate 321: mounting member (first mounting member)
321a: Opening 330 ... Exhaust fan 4 ... Sound transmission film 5 ... Sheet-like sound absorbing material

Claims (6)

A housing enclosing a device for generating heat and sound;
An acoustically permeable membrane and a sheet-shaped sound absorbing material arranged in parallel and spaced apart in the housing,
The soundproofing device, wherein the acoustically permeable film and the sound absorbing material are disposed so as to be orthogonal to a propagation direction of air-borne sound, and the acoustically permeable film is disposed upstream of the sound absorbing material.   The soundproofing device according to claim 1, wherein a mounting member for attaching the sound transmission membrane is disposed between the inner wall of the housing and the device.   The soundproof device according to claim 2, wherein the sound transmission membrane is attached to an opening provided in the mounting member so as to close the opening.   The soundproofing device according to claim 2 or 3, wherein the sound absorbing material is attached to an inner wall of the housing facing the mounting member.   The soundproof device according to any one of claims 1 to 4, wherein an exhaust fan is disposed between the sound transmission membrane and the device.   The soundproof device according to any one of claims 1 to 5, wherein the sound transmission film is made of a material having a property of separating sound and heat.

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