JPH09243154A - Sound absorbing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a sound absorbing effect without increasing a flowing resistance within a flow passage by a method wherein a plurality of cylindrical sound absorbing members are arranged within a casing while being contacted to each other in a parallel state in respect to the flow passage or adjacent to each other and then the sound absorbing members are of a hollow structure with their both ends being opened. SOLUTION: A plurality of sound absorbing members 2 are arranged within a casing 1 of a sound absorbing device in parallel with an air flowing direction while being adjacent to each other. The sound absorbing member 2 has its front end 2a and its rear end 2b opened and has a hollow cylindrical structure. In addition, each of the front end 2a and the rear end 2b of the sound absorbing member is fastened to each of a front end fixing fitting 3 and a rear end fixing fitting 4 fixed to the casing 1. An intermediate section of each of the sound absorbing members 2 fixes the arrangement of the sound absorbing members 2 by an intermediate holding fitting 5 fixed to the casing 1 so as to prevent their positions from being displaced by aeration of air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing device that is used by inserting it into an air passage to reduce noise from a compressor or a blower.

[0002]

2. Description of the Related Art Conventionally, in order to reduce noise from a duct opening, a ventilation duct used for a blower is provided with a sound absorbing device in the middle of the ventilation duct or at a suction port or an exhaust port of the duct. As a conventional sound absorbing device of this type, a sound absorbing duct having a sound absorbing material attached to the inside of the duct or a duct silencer has been used. 7 to 9 are respectively a front view, a side view, and FIG. 8 for explaining the duct silencer.
2 is a plan sectional view taken along line BB ′ of FIG. As shown in the figure, the duct silencer has
It has a side surface sound absorbing portion 11a and a splitter sound absorbing portion 11b. A flow path is formed between the side surface sound absorbing portion 11a and the splitter sound absorbing portion 11b. In addition, the side sound absorbing part 1
The 1a and the splitter sound absorbing portion 11b are composed of a sound absorbing material 12 for absorbing noise and a punching plate 13 that covers the sound absorbing material 12.

[0003]

However, when the sound absorbing duct is used, the sound absorbing effect is small, and a long sound absorbing duct must be used in order to obtain a predetermined sound reduction volume, which results in a large installation space. There is a problem that it will end up. Further, when the noise level of the noise source is high, there is a problem that it is difficult to obtain a sufficient noise reduction effect only with the sound absorbing duct. On the other hand, when using a duct silencer, there is an advantage that the sound deadening effect is large compared to the sound absorbing duct, but it is expensive and has a problem that the workability is not good due to the difference in size and shape from the ventilation duct. ing. Therefore, it is an object of the present invention to provide a low-cost sound absorbing device that has a sound reduction effect similar to that of a duct silencer and that has excellent workability.

[0004]

According to the present invention, a plurality of cylindrical sound absorbers are arranged in parallel with a flow path in a cylindrical casing so as to be in contact with each other or close to each other. It is characterized by having a hollow structure having openings at both ends.
Further, a front end fixing metal fitting and a rear end fixing metal fitting are arranged in the casing perpendicularly to the flow path, the front end fixing metal fitting and the rear end fixing metal fitting have a lattice structure, and both ends of the sound absorbing body are respectively connected to the front end. It is preferable to fasten to the lattice points of the fixing bracket and the rear end fixing bracket. Further, it is preferable to provide an intermediate holding metal fitting for holding the sound absorbing body between the front end fixing metal fitting and the rear end fixing metal fitting.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a plurality of hollow cylindrical sound absorbers having openings at both ends are provided in contact with each other in the flow path or in the vicinity thereof in parallel with the flow path. Thereby, the sound absorbing effect can be enhanced without increasing the flow resistance in the flow path. In particular, by providing the sound absorbers in contact with each other, it is possible to fill the inside of the casing without any gap, so that the contact area of the sound absorbers with respect to the air flow can be increased and the sound absorption efficiency is good. Also, the sound absorbers are 1/3 of the diameter of the sound absorber.
The sound absorption efficiency can be maintained even though the ventilation area can be widened and the ventilation capacity can be increased by providing them in the vicinity of not more than twice. In addition, since the front end fixing metal fittings and the rear end fixing metal fittings of the lattice structure are provided in the flow path and the sound absorber is fastened to the grid points of these fixing metal fittings and provided in the flow path, the front end fixing metal fittings and the rear end fixing metal fittings are provided. If it is installed according to the shape of the duct, it is possible to perform construction according to the shape of the duct and the sound reduction level by adjusting the number of sound absorbers installed. Therefore, since it is not necessary to change the sound absorber itself according to the shape of the duct and the sound reduction level, the construction can be easily performed. Further, since the sound absorbing body is held by the intermediate holding metal fitting, the positional displacement does not occur due to ventilation. Therefore, it is possible to prevent the sound absorption effect from decreasing and the distribution resistance from increasing due to the displacement.

[0006]

Embodiments of the sound absorbing device according to the present invention will be described with reference to the drawings. 1 is a front view of the sound absorbing device according to the embodiment, FIG. 2 is a side view of the same, FIG. 3 is a sectional view taken along the line AA 'of FIG. 2, and FIG. 4 is a perspective view of a main part showing a front end fixing portion of the sound absorbing body. It is a figure. As shown in the figure, in the casing 1 of the sound absorbing device,
The plurality of sound absorbers 2 are arranged in the vicinity of and parallel to the ventilation direction. The sound absorbing body 2 includes a front end portion 2a and a rear end portion 2 thereof.
b is an opening and has a hollow cylindrical shape.

The sound absorbing body 2 uses glass wool as a sound absorbing material and is used by covering a glass cloth with a bag sewn in a tubular shape. It is possible to provide a sound absorbing body of excellent quality and inexpensive. Instead of glass cloth, non-woven fabric, gold wire, punching sheet, etc. may be used.

Further, the front end portion 2a and the rear end portion 2 of the sound absorbing body 2 are
b is fastened to the front end fixing fitting 3 and the rear end fixing fitting 4 fixed to the casing 1, respectively. The middle portion of the sound absorbing body 2 is fixed to the casing 1 by an intermediate holding metal fitting 5 so that the arrangement of the sound absorbing body 2 is fixed so that the sound absorbing body 2 is not displaced due to ventilation. The intermediate holding metal fittings 5 may be provided in two or more places depending on the length of the sound absorbing body 2.

Here, the front end fixing member 3, the rear end fixing member 4, and the intermediate holding member 5 are those having a lattice structure such as gold lining. In the above-mentioned embodiment, the front end fixing member 3, the rear end fixing member 4, and the intermediate holding member 5 are made of gold, but those having a lattice structure such as gold are perpendicular to the surface without increasing ventilation resistance. Strong against stress in various directions,
Moreover, the fastening portion is not displaced by fastening at the lattice points. Therefore, for example, a perforated plate, which can be expected to have the same action and effect, is also included in the concept of the lattice structure described in this embodiment.

Further, although the lattice of the front end fixing metal fitting 3 shown in FIG. 1 has a size whose one side is a length approximately equal to the diameter of the sound absorbing body 2, a finer lattice can be used. In addition to not only further increasing the stress in the direction perpendicular to the surface, but also increasing the degree of freedom in mounting the sound absorbing body 2, it is possible to easily increase or decrease the number of mounting the sound absorbing body 2 according to the sound absorbing level.

FIG. 5 is a front view of a sound absorbing device showing another embodiment. The members having the same functions as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. As shown in the figure, the sound absorbing material 6 is further attached to the inner surface of the casing 1. With such a configuration, the sound absorbing effect can be further enhanced.

FIG. 6 is a perspective view of an essential part showing a front end fixing portion of a sound absorbing body according to still another embodiment. As shown in the figure, in this embodiment, a fixing ring 3b is fixed to the lattice point 3a of the front end fixing fitting 3, and the sound absorbing body 2 is fixed to this fixing ring 3b.
The front end portion of is inserted and held. Sound absorber 2
The rear end portion can also be similarly configured.

As described above, the sound absorbing device according to the present embodiment has a simple structure and the same sound reducing effect as that of the conventionally used split silencer can be obtained, and the manufacturing cost can be reduced. In addition, as a sound absorber, a cylinder diameter of 15 to 300 A
If a glass wool heat insulation tube (JIS A9504 glass wool heat insulation tube) having an inner diameter of 22 to 319 mm and a length of 1 n (n: integer) m is used, the heat insulation tube has various diameters depending on the pipe diameter and the wall thickness. A cylindrical sound absorber suitable for various duct sizes can be selected, which is advantageous in terms of performance, quality and cost.

[0014]

According to the present invention, the sound absorbing effect can be enhanced without increasing the flow resistance in the flow passage. Further, since it is not necessary to change the sound absorber itself according to the shape of the duct and the sound reduction level, the construction can be easily performed.

[Brief description of drawings]

FIG. 1 is a front view of a sound absorbing device according to an embodiment of the present invention.

FIG. 2 is a side view of the sound absorbing device.

3 is a sectional view taken along the line AA ′ of FIG.

FIG. 4 is a main part perspective view showing a front end fixing portion of the sound absorbing body according to the embodiment.

FIG. 5 is a front view of a sound absorbing device showing another embodiment.

FIG. 6 is a front end fixing portion of a sound absorbing body according to another embodiment.

FIG. 7 is a front view of a conventional duct silencer.

FIG. 8 is a side view of the duct silencer.

9 is a plan sectional view taken along the line BB ′ of FIG.

[Explanation of symbols]

 1 Casing 2 Sound Absorber 2a Front End 2b Rear End 3 Front End Fixing Metal 4 Rear End Fixing Metal 5 Intermediate Holding Metal 6 Sound Absorbing Material 10 Casing 11a Side Sound Absorbing Part 11b Splitter Sound Absorbing Part 12 Sound Absorbing Material 13 Punching Plate

Claims (3)

[Claims] 1. A plurality of cylindrical sound absorbers are arranged in parallel with a flow path in a casing so as to be in contact with each other or close to each other, and the sound absorber has a hollow structure having openings at both ends. A sound absorbing device characterized by the above. 2. A front end fixing member and a rear end fixing member are arranged in the casing perpendicularly to a flow path, and the front end fixing member and the rear end fixing member have a lattice structure, and both ends of the sound absorbing body are connected to each other. The sound absorbing device according to claim 1, wherein the sound absorbing device is fastened to lattice points of the front end fixing member and the rear end fixing member, respectively. 3. The sound absorbing device according to claim 2, wherein an intermediate holding metal fitting for holding the sound absorbing body is provided between the front end fixing metal fitting and the rear end fixing metal fitting.