JPH09217955A - Sound absorbing flexible duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance an effect of sound absorption and to ensure a sufficient effect of sound absorption even when a measure for preventing scattering of a sound absorbing material is taken, regarding a flexible duct which connects an air conditioner with an air outlet, a duct, a chamber, etc., in a flexible manner. SOLUTION: An aluminum foil layer 2 has bellows-like indentations. Therefore the surface area of the aluminum foil layer 2 is large and the number of holes 2b which can be bored therein can be increased. This makes it easy for noise to pass through the holes 2b and the efficiency of sound absorption is enhanced. Moreover, a gap having a large space is formed between the outer recessions of the aluminum foil layer 2 and a layer of a sound absorbing material and the noise propagating through a space inside a duct enters this gap through the holes 2b. Therefore absorption of the noise in the layer of the sound absorbing material and sound absorption due to interference, attenuation, etc., of the sound in the gap are enabled. Thus an effect of sound absorption is improved sharply as a whole and attainment of reliable sound absorption is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible duct for flexibly connecting an air conditioner and an air outlet, a duct, a chamber, etc. to each other, and particularly suppresses blast noise generated by a supplied gas. Sound absorbing flexible duct.

[0002]

2. Description of the Related Art Conventionally, noise generated from an air conditioner such as a blower or a heat pump or noise generated in an adjacent room has a flexible structure for connecting an air conditioning main duct and an air supply chamber and an air outlet to the room. It may enter the room through the duct, and as a countermeasure, the sound absorbing duct 1 shown in FIG.
00 was used. FIG. 6 shows a schematic configuration diagram of a conventional sound absorbing duct. In the conventional sound absorbing duct 100, one end of the strip-shaped mesh sheet 101 in the width direction is arranged on the outer circumference of the winding of the coil 102 and the other end is arranged on the inner circumference of the winding one pitch after the winding. The mesh sheet 101 is formed into a spiral shape so as to fit the leads of the coil 102,
Adhere between the mesh sheets 101 that overlap with each other,
Further, a sound absorbing material layer 103 such as glass wool is formed on the outer periphery of the mesh sheet 101, and the sound absorbing material layer 103 is covered with a coating material 104.
It is a structure covered with. Sound absorbing duct 100 having the above-mentioned configuration
The noise entering the inside passes through the mesh of the mesh sheet 101 while propagating in the sound absorbing duct 100, and the sound absorbing material layer 103
It is a mechanism that is absorbed by and is not transmitted to the air outlet (not shown).

[0003]

Conventional sound absorbing duct 10
0 is configured as described above, and noise is absorbed only by the sound absorbing material layer 103, so the sound absorbing effect is not always sufficient. In addition, since fine fibers such as glass wool, which is a sound absorbing material, may fly into the space inside the duct through the mesh sheet 101 and reach the room through the air outlet, avoiding this, the sound absorbing material layer 103 and the mesh sheet are avoided. 101
Although measures such as providing a polyethylene sheet layer between them were taken, as a result, there is a problem that the polyethylene sheet layer interferes with the absorption of noise by the sound absorbing material and the sound absorbing effect is greatly reduced. It was The present invention has been made to solve the above problems, and an object of the present invention is to provide a sound absorbing flexible duct that has a high sound absorbing effect and can secure a sufficient sound absorbing effect even when measures are taken to prevent scattering of the sound absorbing material.

[0004]

The sound absorbing flexible duct according to the present invention comprises an aluminum foil layer formed as a tubular body having bellows-like irregularities made of an aluminum foil film having a plurality of holes formed therein, and the aluminum foil. An inner wire, which is spirally arranged on the outer periphery of the layer, is formed of a wire having elasticity, and is arranged outside the aluminum foil layer and the inner wire, and is made of a fiber material.
Also, the sound absorbing material layer is formed to be bendable with the inner side surface as a substantially smooth surface, and is arranged spirally on the outside of the sound absorbing material layer,
An outer wire formed of a wire material having elasticity, and formed in an uneven bellows shape in accordance with the spiral shape of the outer wire, and on the outer circumference of the outer wire so that the outer wire is located in the outer convex portion of the bellows shape. And an outer coating overlaid with a flexible polymeric material. As described above, in the present invention, since the aluminum foil layer has the bellows-like irregularities, the surface area of the aluminum foil layer is large, and the number of holes that can be drilled can be increased. As the height increases, a large space gap is formed between the outer recess of the aluminum foil layer and the sound absorbing material layer, and noise propagating in the duct inner space passes through the hole and enters the air layer in this gap.
It is possible to absorb noise in the sound absorbing material layer and to absorb sound due to interference and attenuation of sound in the air layer in the gap, so that the sound absorbing effect as a whole is greatly improved, and reliable noise reduction is possible.
And because the entire duct has elasticity, it can be contracted to a compact state, easy to carry in large quantities at one time, easy to carry, installation workability is good, and storability is good and storage location can be selected. Absent.

In the sound absorbing flexible duct according to the present invention, if necessary, a strip-shaped aluminum foil film is spirally wound with the longitudinal edges partially overlapping, and the aluminum foil films are overlapped with each other. The spiral inner wire is held to form a tubular body, and the aluminum foil layer is formed.
As described above, in the present invention, the aluminum foil layer is spirally wound while partially overlapping the aluminum foil layer to form the tubular aluminum foil layer, thereby easily forming the aluminum foil layer having a complicated shape having irregularities. In addition, the positions of the aluminum foil layer and the inner wire are firmly linked to each other, and even when various external forces are applied, the gap formed by the bellows-like irregularities of the aluminum foil layer is not crushed and sufficient air is not crushed. Since the layers can be maintained, the silencing effect can be surely executed, and the robustness of the duct itself can be improved.

Further, the sound absorbing flexible duct according to the present invention has a polyethylene sheet layer disposed between the aluminum foil layer and the inner wire and the sound absorbing material layer, if necessary. As described above, in the present invention, by covering the sound absorbing material layer from the inside with respect to the space inside the duct with the polyethylene sheet layer, the fine fibers of the sound absorbing material are separated from the sound absorbing material layer and come out from the holes of the aluminum foil layer. In addition, it is possible to prevent scattering in the space in the duct, and even if the sound absorbing effect of the sound absorbing material layer is reduced by the polyethylene sheet layer, sufficient sound absorbing effect can be secured by the sound absorption of the gap.

In the sound absorbing flexible duct according to the present invention, an aluminum foil layer is provided between the sound absorbing material layer and the outer wire and outer coating, if necessary. As described above, in the present invention, by covering the sound absorbing material layer from the outside with the aluminum foil layer, mutual heat transfer between the space in the duct and the outside air is less likely to occur, and the sound absorbing material layer is insulated. In the case of playing the role of, the heat insulating effect can be maintained even if the amount of the sound absorbing material is reduced and only the amount necessary for sound absorption is provided.

Further, the sound absorbing flexible duct according to the present invention is formed by an annular body having an L-shaped cross section, if necessary.
The base portion of the letter is formed to have an outer diameter equal to the inner diameter of the aluminum foil layer, and is formed with a base inserted into the opening end of the sound absorbing flexible duct, and a cylindrical body, and the connected portion is connected to one end of the cylindrical body. A connecting portion is formed in a shape that conforms to the opening shape, and a step portion is formed at the other end with an inner diameter equal to the outer coating outer diameter, and the mouthpiece is housed in the step portion, and the sound absorbing member is provided between the mouthpiece and the step portion. And a duct joint for holding the open end of the flexible duct in a clamped state. As described above, in the present invention, by holding the open end of the sound absorbing flexible duct in such a manner as to be held between the outside and the inside by the duct joint and the base,
When connecting the duct joint to the connected part and feeding the gas through the sound absorbing flexible duct, the connecting work between them can be performed with a simple one-touch operation, and the gas can be transferred between the sound absorbing flexible duct body and the duct joint. This can be reliably prevented and airtightness can be maintained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

(One Embodiment of the Invention) A sound absorbing flexible duct according to one embodiment of the present invention will be described below with reference to FIGS. 1 is a side view of a main portion of a sound absorbing flexible duct according to the present embodiment, FIG. 2 is a vertical sectional view of FIG. 1, FIG. 3 is a partially enlarged view of FIG. 2, and FIG. 4 is a diagram of a sound absorbing flexible duct according to the present embodiment. FIG. 5 is an explanatory view of a use state, and FIG. 5 is an explanatory view of a mounting operation of the sound absorbing flexible duct according to the present embodiment.

In each of the above figures, the sound absorbing flexible duct 1 according to the present embodiment is wound in a spiral shape according to the inner diameter of the duct, and is composed of the inner wire 3 made of steel wire and the pitch of the winding of the inner wire 3. A strip having a sufficiently large width, and one side edge of the aluminum foil film 2a in which a plurality of holes 2b are formed is the outer circumference of the winding of the inner wire 3, and the other side edge is one pitch after the winding. The aluminum foil film 2a is spirally wound so that the slack of the aluminum foil film 2a forms a bellows-like unevenness by arranging the aluminum foil film 2a along the spiral shape of the inner wire 3 while arranging it on the inner circumference of the wire and overlapping the side edges. The inner wire 3 is sandwiched and the overlapping aluminum foil films 2a are adhered to each other, and the aluminum foil layer 2 is formed as a tubular body, and the aluminum foil layer 2 is disposed on the outer side of the aluminum foil layer 2. A gap 4 is formed between the aluminum foil layer 2 and the outer concave portion 2c. A glass wool layer 5 as a sound absorbing material layer formed, helically wound in accordance with the duct outer diameter on the outside of the glass wool layer 5, an outer wire 6 made of steel wire
And a polymer outer coating which is formed in a bellows shape having irregularities in conformity with the spiral shape of the outer wire 6 and is coated along the outer circumference of the outer wire 6 so that the outer wire 6 is located in the bellows-shaped outer convex portion 7a. 7 is provided, and the entire hollow tubular body is bendable. The polymer outer coating 7
Alternatively, it is also possible to form the flexible polymer tape by spirally winding it with the outer wire 6 being held between the flexible polymer tape and the aluminum foil layer 2.

This sound absorbing flexible duct has an open end 1
The duct joint 13 is attached to a. The duct joint 13 is formed of a cylindrical body, and the connecting portion 13a is formed at one end of the cylindrical body so as to be fitted to the duct connecting port 23 (see FIG. 4) which is a connected portion and which can be connected with one touch. An expansion step portion 13b having an inner diameter equal to the outer diameter of the polymer outer coating 7 is formed on the other end, and an outer packing 12 which is a rubber O-ring is attached to the inner circumference of the expansion step portion 13b. The mouthpiece 10 is housed in 13b, and the opening end 1a is held between the mouthpiece 10 and the stepped portion 13 in a sandwiched state. The base 10 is formed of an annular body having a substantially L-shaped cross section, the L-shaped base portion 10a is formed to have an outer diameter equal to the inner diameter of the aluminum foil layer 2, and an inner packing 11 that is a rubber O-ring.
Is attached to the outer periphery of the base 10a and is inserted into the opening end 1a.

At the opening end 1a, the base 10a of the mouthpiece 10 is adhered to the aluminum foil layer 2, and the duct joint 1
3 is an L-shaped upright portion 10 of the mouthpiece 10 with its expanded step portion 13b
In addition to being bonded to b, the end of the expansion step portion 13b is squeezed and pressure-bonded to the polymer outer coating 7, so that airtightness is maintained. In addition to gluing, riveting can be performed, and on the condition that sufficient airtightness can be maintained, either one of the outer packing 12 and the inner packing 11 can be used, or both of them can be configured not to be used at all. In the sound absorbing flexible duct 1 according to the present embodiment, the duct joint 13 is connected to each duct connection port 23 of the air-conditioning chamber 21 installed in the ceiling and the air outlet 22 facing the room. The configuration is such that these communicate with each other.

Next, the sound absorbing action of the present embodiment based on the above configuration will be described. When the noise from the air conditioner (not shown) or the adjacent room enters the sound absorbing flexible duct 1 through the main duct 20 and the chamber 21, the noise is transmitted from the hole 2b of the aluminum foil layer 2 while propagating through the space in the duct. It goes out and enters the gap 4 of the air layer formed between the outer concave portion 2c of the aluminum foil layer 2 and the glass wool layer 5. The noise that enters the gap 4 interferes with the noise that enters from the other hole 2b, is attenuated by the reflection in the air layer in the gap 4, and is absorbed by the glass wool layer 5 so that the noise can be silenced. By providing the gap 4 of the air layer formed between the aluminum foil layer 2 and the glass wool layer 5 in this manner, the noise that has escaped from the space in the duct to the gap 4 through the hole 2b of the aluminum foil layer 2 will be the gap 4 itself. Therefore, sound can be effectively absorbed in the glass wool layer 5, and sound can be absorbed to a sufficiently low level as compared with the conventional sound absorbing material using only a sound absorbing material such as glass wool, and noise leakage can be eliminated.

In the present embodiment, the polyethylene sheet layer 8 may be arranged between the aluminum foil layer 2 and the inner wire 3 and the glass wool layer 5. In this case, the glass wool layer 5 is removed. It is possible to prevent the fine fibers from separating, coming out of the holes 2b of the aluminum foil layer 2 and scattering into the space inside the duct. Even in this case, sound can be absorbed in the gap between the aluminum foil layer 9 and the glass wool layer 5, and a sufficient sound absorbing effect can be maintained. Further, in the present embodiment, an aluminum foil layer 9 different from the innermost layer may be arranged between the glass wool layer 5, the outer wire 6 and the polymer outer coating 7, and in this case, The heat transfer to the glass wool layer 5, which also functions as a heat insulating material, is blocked by the aluminum foil layer 9 to further improve the heat insulating properties of the space inside the duct and the outside air, and the efficiency of the entire air conditioning equipment can be increased.

[0015]

As described above, in the present invention, since the aluminum foil layer has bellows-like irregularities, the surface area of the aluminum foil layer is large, and the number of holes that can be formed is increased, and noise is generated. It is easy to pass and the sound absorption efficiency is increased,
A large space gap is formed between the outer recess of the aluminum foil layer and the sound absorbing material layer, and noise propagating in the duct inner space enters the air layer in this gap through the holes, so that noise in the sound absorbing material layer is reduced. It is possible to absorb and absorb sound due to interference and attenuation of sound in the air layer of the gap, the sound absorbing effect as a whole is greatly improved, and reliable sound deadening is possible, and furthermore, the duct as a whole has elasticity, Since it can be contracted into a compact state, it is easy to carry a large amount at a time, can be easily carried, has good installation workability, and has good storability. Also,
In the present invention, by forming a tubular aluminum foil layer by spirally winding while partially overlapping the aluminum foil layer,
It is possible to easily form a complex aluminum foil layer having irregularities, and the positions of the aluminum foil layer and the inner wire are firmly linked to each other, so that the bellows shape of the aluminum foil layer is applied even when various external forces are applied. A sufficient air layer can be maintained without being crushed by the gap formed by the unevenness, and the sound deadening effect can be surely executed and the robustness of the duct itself can be improved. Also,
In the present invention, by covering the sound absorbing material layer from the inside with the polyethylene sheet layer for the space in the duct,
It is possible to prevent fine fibers of the sound absorbing material from separating from the sound absorbing material layer and coming out of the holes of the aluminum foil layer and scattering into the space inside the duct, and even if the sound absorbing effect of the sound absorbing material layer is reduced by this polyethylene sheet layer. The sound absorption in this gap has the effect of ensuring a sufficient sound absorption effect. Further, in the present invention, by covering the sound absorbing material layer from the outside with the aluminum foil layer, it becomes more difficult for mutual heat transfer between the space in the duct and the outside air to occur, and the sound absorbing material layer is insulated. When it plays a role, it has an effect that the heat insulating effect can be maintained even if the amount of the sound absorbing material is reduced and the sound absorbing material is arranged by the amount necessary for sound absorption. Further, in the present invention, by holding the open end of the sound absorbing flexible duct in such a manner that it is sandwiched between the outside and the inside by the duct joint and the mouthpiece, the duct joint is connected to the connected portion to feed the gas through the sound absorbing flexible duct. In doing so, it is possible to perform mutual connection work with a simple one-touch operation, and it is possible to reliably prevent gas from leaking between the sound absorbing flexible duct body and the duct joint, and to maintain airtightness.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a sound absorbing flexible duct according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view in FIG.

FIG. 3 is a partially enlarged view of FIG.

FIG. 4 is an explanatory view of a usage state of the sound absorbing flexible duct according to the embodiment of the present invention.

FIG. 5 is an explanatory view of the mounting operation of the sound absorbing flexible duct according to the embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a conventional sound absorbing flexible duct.

[Explanation of symbols]

 1 Sound Absorption Flexible Duct 1a Open End 2, 9 Aluminum Foil Layer 2a Aluminum Foil Film 2b Hole 2c Outer Recess 3 Inner Wire 4 Gap 5 Glass Wool Layer 6 Outer Wire 7 Polymer Outer Coating 7a Outer Convex 8 Polyethylene Sheet 10 Base 10a Base Part 10b Standing part 11 Inner packing 12 Outer packing 13 Duct joint 13a Connecting part 13b Expanding step part 20 Main duct 21 Chamber 22 Air blowout port 23 Duct connecting part port 100 Sound absorbing duct 101 Mesh sheet 102 Coil 103 Sound absorbing material layer 104 Coating material

Claims (5)

[Claims] 1. An aluminum foil layer formed as a tube body having bellows-shaped irregularities with an aluminum foil film having a plurality of holes formed therein, and an aluminum foil layer spirally arranged on the outer periphery of the aluminum foil layer to provide elasticity. An inner wire formed of a wire having, a sound absorbing material layer disposed outside the aluminum foil layer and the inner wire, made of a fibrous material, and formed to be bendable with the inner side surface being a substantially smooth surface, An outer wire spirally arranged outside the sound absorbing material layer and formed of a wire material having elasticity, and an outer bellows-shaped outer convex portion formed in a corrugated shape corresponding to the spiral shape of the outer wire. A sound-absorbing flexible duct, comprising: an outer coating covering the outer wire with a flexible polymer material along the outer periphery of the outer wire so that the outer wire is located on the outer duct. 2. The sound absorbing flexible duct according to claim 1, wherein a strip-shaped aluminum foil film is spirally wound with the longitudinal edges partially overlapping, and the spiral is provided between the overlapping aluminum foil films. A sound-absorbing flexible duct, characterized in that it holds an inner wire of a rectangular shape to form a tubular body and forms the aluminum foil layer. 3. The sound absorbing flexible duct according to claim 1, wherein a polyethylene sheet layer is provided between the aluminum foil layer and the inner wire and the sound absorbing material layer. . 4. The sound absorbing flexible duct according to any one of claims 1 to 3, wherein an aluminum foil layer is provided between the sound absorbing material layer and the outer wire and outer coating. Flexible duct. 5. The sound absorbing flexible duct according to any one of claims 1 to 4, wherein the sound absorbing flexible duct is formed of an annular body having an L-shaped cross section, and an L-shaped base portion of the annular body is equal to the inner diameter of the aluminum foil layer. Formed on the outer diameter,
A base that is inserted into the opening end of the sound absorbing flexible duct, and is formed of a cylindrical body, a connecting portion having a shape that matches the opening shape of the connected portion is formed at one end of the cylindrical body, and the outer end is formed at the other end. A step portion is formed with an inner diameter equal to the outer diameter of the coating, the die is housed in the step portion, and a duct joint for holding the open end of the sound absorbing flexible duct in a sandwiched state is provided between the die and the step portion. Characteristic sound-absorbing flexible duct.