WO2011108527A1

WO2011108527A1 - Duct hose

Info

Publication number: WO2011108527A1
Application number: PCT/JP2011/054599
Authority: WO
Inventors: 龍志吉田; 康博菊森; 達也町野; 慶治中俣; 一行南; 洋一郎月江; 史和松下
Original assignee: 東拓工業株式会社
Priority date: 2010-03-05
Filing date: 2011-03-01
Publication date: 2011-09-09
Also published as: CN102770719A; CN102770719B; JP5634083B2; JP2011185480A

Abstract

Provided is a duct hose wherein, even with a simple structure, the acoustic absorption performance is remarkably improved. In the duct hose, an outer layer (4) composed of a cylindrical soft resin layer is provided on the outer peripheral surface of an inner layer (1) composed of a cylindrical foamable resin layer via a reinforcing core element (2), so that a clearance portion (5) is formed between the outer peripheral surface of the inner layer (1) and the inner peripheral surface of the outer layer (4); and a plurality of acoustic absorption holes (10) are formed in the inner layer (1), and an inner space (6) communicates with the clearance portion (5) via the acoustic absorption holes (10), so that a noise propagating through the inner space (6) is introduced to the clearance portion (5).

Description

Duct hose

The present invention relates to a duct hose used for air supply / exhaust of air conditioning equipment in a house or a building, for example.

Conventionally, duct hoses for air supply / exhaust have been provided with noise reduction measures to prevent noise from being propagated indoors by attenuating the noise generated from the air source as much as possible inside the hose.

As this type of duct hose, for example, as disclosed in Patent Document 1, a cylindrical foamed resin layer having a plurality of sound absorbing holes is provided, and inner opening ends of the plurality of sound absorbing holes in the foamed resin layer are provided. A structure having a structure in which noise propagating in the internal space of the hose is guided from the thin film ventilation hole to the sound absorption hole of the foamed resin layer is covered with a thin film made of non-woven fabric or the like having air permeability. .

In the duct hose having such a structure, the contact area of the noise in the foamed resin layer is expanded, and the sound absorbing hole portion covered with the thin film exhibits a silencing action similar to that of the resonator, so that it does not have a sound absorbing hole. Compared to the structure having a foamed resin layer, the sound absorption performance can be improved.

JP 2006-313043 A

However, the duct hose described above has a structure in which noise can be attenuated only at the thin film portion on the inner peripheral surface side of the foamed resin layer and the sound absorbing hole portion of the foamed resin layer, and a fundamentally high sound absorbing performance is expected. It wasn't possible. In particular, if the number of sound absorbing holes is reduced or the size of the sound absorbing holes is reduced to reduce the proportion of the sound absorbing holes in the entire foamed resin layer, the sound absorbing performance will be reduced. Increasing the number of holes or increasing the size of the sound absorbing holes to increase the proportion of the sound absorbing holes in the entire foamed resin layer to improve the sound absorbing performance leads to a decrease in the strength of the foamed resin layer. The shape retention of the hose is impaired, and the heat insulation performance of the hose is also reduced.

Therefore, the present invention aims to provide a duct hose that can solve the above-mentioned problems and can significantly improve the sound absorption performance while having a simple structure without impairing the strength and heat insulation performance of the hose. And

In the duct hose of the present invention, a cylindrical outer layer 4 is provided on the outer peripheral surface side of the inner layer 1 made of a cylindrical foamed resin layer via a reinforcing core member 2, so that the outer peripheral surface of the inner layer 1 and the outer layer 4 A gap portion 5 is formed between the inner peripheral surface and a plurality of sound absorbing holes 10... Communicating with the internal space 6 through which gas flows are formed in the inner layer 1, and the sound absorbing holes 10. The outer open end 10b on the outer peripheral surface side of the inner layer 1 is made to face the gap portion 5.

Specifically, the sound absorbing holes 10... Have a cross-sectional shape in which the hole diameter increases from the inner peripheral surface side to the outer peripheral surface side of the inner layer 1. The sound absorbing holes 10... Communicate with the inner space 6 such that the inner opening ends 10 a on the inner peripheral surface side of the inner layer 1 in the sound absorbing holes 10. is doing. Alternatively, the sound absorption holes 10... Are covered with the thin film 1 a with air permeability so that the inner opening ends 10 a on the inner peripheral surface side of the inner layer 1 in the sound absorption holes 10. .. communicated with the internal space 6 through the ventilation holes.

Further, the inner layer 1 is formed by spirally winding a band-shaped foamed resin material 11 having the sound absorbing holes 10... And adjacent edges of the preceding foamed resin material 11 and the subsequent foamed resin material 11. The parts are joined together via the reinforcing core 2 that is spirally wound along the edge portions, and the reinforcing core 2 is interposed between the outer peripheral surfaces of the adjacent edge portions. A horizontal piece 21 that straddles and a vertical piece 22 that extends from the horizontal piece 21 in the hose radial direction and enters between the adjacent edge portions.

Furthermore, the reinforcing core member 2 is provided with a rising piece 23 that extends from the lateral piece 21 outward in the hose diameter and pushes the outer layer 4 outward in the hose diameter. Or the elastic spacer 50 which is attached to the outer peripheral surface of the horizontal piece 21 of the said reinforcement core material 2 and pushes the said outer layer 4 in the hose diameter outward direction is provided.

Furthermore, the auxiliary reinforcing wire 3.. Is spirally wound around the outer peripheral surface side of the inner layer 1 along the middle portion of the foamed resin material 11.

The outer layer 4 is formed by spirally winding a belt-shaped soft resin sheet material 40 and joining adjacent edge portions of the preceding soft resin sheet material 40 and the subsequent soft resin sheet material 40 to each other. Become. Further, the reinforcing core member 2 and the outer layer 4 are not bonded. Furthermore, among the plurality of sound absorbing holes 10..., Some or all of the sound absorbing holes 10.

In the duct hose according to the present invention, the noise propagating in the internal space can be guided to the gap formed between the inner layer and the outer layer through a plurality of sound absorbing holes formed in the inner layer. Therefore, the contact area of the noise in the inner layer and the outer layer can be greatly expanded to efficiently absorb the noise, and the sound absorbing performance can be remarkably improved while having a simple structure.

Moreover, it is possible to obtain a satisfactory sound absorption performance by ensuring a sufficient contact area of noise without increasing the number of sound absorbing holes in the inner layer as much as possible or without increasing the size of the sound absorbing holes as much as possible. It is possible to maintain the good shape retention of the hose while suppressing a decrease in strength of the hose. In addition, since an air layer is formed by the gap between the inner layer and the outer layer and an air heat insulating effect is obtained, the heat insulating performance of the hose can be improved.

Also, by making the inner opening end of the sound absorbing hole small in diameter, the inner peripheral surface of the inner layer can be made to be in a substantially smooth state with little unevenness, and the ventilation resistance at the time of air supply / exhaust can be kept small. Furthermore, by making the inner opening end of the sound absorption hole directly face the internal space, it is possible to reliably guide the noise propagating in the internal space to the gap, and stably maintain good sound absorption performance. Furthermore, by covering the inner opening end of the sound absorbing hole with a thin film having air permeability, the inner peripheral surface of the inner layer is maintained in a substantially smooth state with almost no unevenness, and the ventilation resistance during air supply and exhaust is further reduced. Can be suppressed.

In addition, the reinforcing core material provided with the horizontal piece and the vertical piece is wound around the outer peripheral surface side of the inner layer, and the edge portions of the foamed resin material of the inner layer are joined to each other through the reinforcing core material, so that the inner layer is effective. In particular, the inner layer can be prevented from being crushed by external pressure, and the shape retaining property of the hose can be maintained well.

Moreover, although the reinforcing core material is provided to reinforce the inner layer, the reinforcing core material does not hinder ventilation. Furthermore, the edges of the foam resin material of the inner layer are firmly joined to each other, so that even if the hose is bent, there is no opening between the edges of the foam resin material of the inner layer, and a crack occurs in the inner layer. It has become difficult. Thereby, the ventilation resistance at the time of air supply / exhaust can be suppressed small.

Furthermore, the outer layer is pushed outward in the hose diameter direction by the rising piece of the reinforcing core material, or the outer layer is pushed outward in the hose diameter direction by the elastic spacer attached to the reinforcing core material, so that the height of the gap portion in the hose radial direction is increased. The gap can be stably formed while ensuring sufficient thickness. In addition, when an elastic spacer is used, the flexibility of the hose can be improved.

Moreover, by winding the auxiliary reinforcing wire around the outer peripheral surface side of the inner layer, the shape retention of the hose can be further enhanced, and the generation of wrinkles and slack in the outer layer is suppressed, and the void portion is stably formed. be able to.

Furthermore, by using an outer layer formed by spirally winding a belt-shaped soft resin sheet material, it is possible to effectively attenuate the noise guided to the gap and further improve the sound absorption performance. In addition, by setting the reinforcing core member and the outer layer in a non-adhered state, the outer layer can be prevented from adhering along the shape of the reinforcing core member, and the void portion can be stably formed.

It is a partially broken perspective view of the duct hose according to the first embodiment of the present invention. It is the longitudinal cross-sectional view similarly. It is the principal part longitudinal cross-sectional view similarly. It is a principal part longitudinal cross-sectional view of the state which bonded the joined part of the outer layer just above the reinforcing core material. It is a principal part longitudinal cross-sectional view which shows the modification of the duct hose which concerns on 1st Embodiment. It is a partial fracture perspective view of a duct hose concerning a 2nd embodiment of this invention. It is the longitudinal cross-sectional view similarly. It is the principal part longitudinal cross-sectional view similarly. It is a principal part longitudinal cross-sectional view which shows the modification of the duct hose which concerns on 2nd Embodiment. It is a principal part longitudinal cross-sectional view of the duct hose which made the shape and magnitude | size of a sound absorption hole different. It is a principal part longitudinal cross-sectional view of the duct hose which made the shape and magnitude | size of a sound absorption hole different. It is a principal part longitudinal cross-sectional view of the duct hose using the reinforcement core material of a cross-sectional substantially T shape.

(First embodiment)
The duct hose according to the first embodiment of the present invention is connected to an air supply / exhaust port of a cooling / heating device such as a house or a building, or is connected to an air supply / exhaust port of a ventilation device, and is used for air supply / exhaust to these air conditioning equipment. Used as

As shown in FIGS. 1 to 3, this duct hose has a thin-film cylindrical shape on the outer peripheral surface side of the inner layer 1 made of a thick-walled cylindrical foamed resin layer via a reinforcing core member 2 and auxiliary reinforcing wire members 3. By laminating the outer layer 4 made of a soft resin layer, a gap portion 5 is formed between the outer peripheral surface of the inner layer 1 and the inner peripheral surface of the outer layer 4. This duct hose has flexibility as a whole, and allows gas (air for supply / exhaust) to circulate in the internal space 6 surrounded by the inner peripheral surface of the inner layer 1.

The inner layer 1 is formed with a plurality of substantially V-shaped sound absorption holes 10... Penetrating in the hose radial direction at appropriate intervals in the hose axial direction and the hose circumferential direction. These sound absorbing holes 10... Gradually increase in diameter from the inner peripheral surface to the outer peripheral surface of the inner layer 1, and a small-diameter inner opening end 10 a that opens to the inner peripheral surface of the inner layer 1 faces the inner space 6. In this case, a large-diameter outer opening end 10 b that opens to the outer peripheral surface of the inner layer 1 faces the gap portion 5. Thereby, the sound absorption holes 10... Are in communication with the internal space 6 and the gap 5. In other words, the internal space 6 and the gap portion 5 are in communication with each other via the sound absorption holes 10..., And noise propagating in the internal space 6 is transmitted to the gap portion 5 via the sound absorption holes 10. It has come to be guided.

Specifically, the hole diameters of the inner opening ends 10a in the sound absorbing holes 10 are set to 0.1 mm to 10.0 mm (preferably 0.5 mm to 2.0 mm), and the outer opening ends 10b,. Is set to be twice or more (preferably 2.0 mm to 10.0 mm) of the inner opening end 10a. As described above, by setting the inner opening end 10a.. be able to. Note that the size and shape of the sound absorbing holes 10 are not limited to the above.

The inner layer 1 is formed by spirally winding a band-shaped foamed resin material 11 made of, for example, a foamed polyethylene resin or a foamed urethane resin having sound absorbing holes 10. It is comprised by joining the edge parts which adjoin each other of the material 11 via the reinforcement core material 2 formed by spirally winding along these edge parts. In addition, as the foamed resin material 6, an open cell structure is used, but a closed cell structure may be used.

As shown in FIG. 3, the reinforcing core member 2 is an extruded product made of, for example, hard polypropylene resin or polyethylene resin, and has a substantially cross-shaped cross section. Specifically, the reinforcing core member 2 includes a horizontal piece 21 straddling between outer peripheral surfaces of adjacent edge portions of the preceding foamed resin material 11 and the subsequent foamed resin material 11 in the inner layer 1, and A vertical piece 22 extending from the central portion in the width direction into the hose diameter inward direction and entering between the adjacent edge portions (specifically, between the opposing end surfaces), and the horizontal direction center of the horizontal piece 21 And a rising piece 23 that extends outward from the hose diameter and pushes the outer layer 4 outward in the hose diameter. The height of the vertical piece 22 in the hose radial direction is equal to or slightly lower than the thickness of the foamed resin material 11 (height in the hose radial direction), and the bonding area with the end surface of the foamed resin material 11 While ensuring sufficient, it does not protrude to the inner peripheral surface side of the inner layer 1. Further, the reinforcing core material 2 and the foamed resin material 11 are bonded by heat fusion using the heat of fusion at the time of extrusion molding of the reinforcing core material 2, but may be bonded using an adhesive. good.

Further, on the outer peripheral surface side of the inner layer 1, a plurality of (specifically, three) auxiliary reinforcing wires 3... Are spirally wound along the width direction intermediate portion of the foamed resin material 11. That is, on the outer peripheral surface side of the inner layer 1, the reinforcing core member 2 and the auxiliary reinforcing wire members 3 are wound spirally at substantially equal intervals in the hose axial direction.

These auxiliary reinforcing wires 3... Are extrusion-molded products made of, for example, hard polypropylene resin or polyethylene resin, like the reinforcing core material 2, and have a substantially circular cross section. The amount of the auxiliary reinforcing wire 3... Protruding outward in the hose diameter direction is smaller than the amount of the reinforcing core member 2 protruding outward in the hose diameter direction. Further, the auxiliary reinforcing wire 3 ·· and the foamed resin material 11 are bonded by heat fusion using heat of fusion at the time of extrusion molding of the auxiliary reinforcing wire 3 ··, but are bonded using an adhesive. You may do it.

Thus, the inner core 1 is effectively reinforced by wrapping the reinforcing core 2 and the auxiliary reinforcing wire 3... Around the outer peripheral surface side of the inner layer 1, and particularly the reinforcing core 2 and the auxiliary reinforcing wire against the external pressure. 3.. Positively resists the inner layer 1 from being crushed. In addition, since the reinforcing core member 2 and the auxiliary reinforcing wire 3... Do not exist on the inner peripheral surface side of the inner layer 1 facing the inner space 6, these do not hinder ventilation. Further, the horizontal piece 21 of the reinforcing core material 2 is bonded across the outer peripheral surface of the edge portion of the foamed resin material 11, and the vertical piece 22 is bonded in a state of being sandwiched between the end surfaces of the foamed resin material 11. For this reason, the end portions of the foamed resin material 11 are firmly joined in the inner layer 1. Thereby, even if the duct hose is curved, the gap between the edge portions of the foamed resin material 11 of the inner layer 1 is not opened, and a crack is hardly generated in the inner layer 1.

The outer layer 4 is formed by, for example, winding a non-breathable strip-shaped soft resin sheet material 40 made of a soft polyolefin-based elastomer resin into a spiral shape, followed by the preceding soft resin sheet material 40 and the subsequent soft resin sheet material 40. The edge portions adjacent to each other are overlapped and bonded using heat fusion or an adhesive tape.

The rising piece 23 of the reinforcing core material 2 and the auxiliary reinforcing wire 3... Are pressed against the inner peripheral surface of the outer layer 4. As a result, the outer layer 4 is in a stretched state in which wrinkles and slack are unlikely to occur, and a gap in which the height in the hose radial direction is sufficiently secured between the outer peripheral surface of the inner layer 1 and the inner peripheral surface of the outer layer 4 5 is formed stably. Moreover, the joining part 41 of the edge parts which adjoin each other of the soft resin sheet material 40 in the outer layer 4 is arrange | positioned so that the upper part of the reinforcement core material 2 may be avoided, and via the adhesive tape which is not shown in figure with respect to the auxiliary reinforcement wire 3. Are glued together. That is, the outer layer 4 is not bonded to the reinforcing core material 2 and is bonded to the auxiliary reinforcing wire 3. As a result, for example, as shown in FIG. 4, the outer layer 4 is brought into close contact with the shape of the rising piece 23 of the reinforcing core member 2, thereby eliminating the problem of narrowing the gap 5.

The duct hose with the above configuration is manufactured as follows. First, a strip-shaped foamed resin material 11 having a plurality of sound absorbing holes 10... Is spirally wound on a mandrel. Subsequently, the reinforcing core material 2 extruded by the extruder is spirally wound along adjacent edge portions of the preceding foamed resin material 11 and the succeeding foamed resin material 11. At this time, in a state where the horizontal piece 21 is straddled between the outer peripheral surfaces of the adjacent edge portions while the vertical piece 22 of the reinforcing core material 2 is inserted between the adjacent edge portions, the reinforcing core material 2 The reinforcing core material 2 and the foamed resin material 11 are integrated by thermal fusion using the heat of fusion at the time of extrusion molding. At the same time, the auxiliary reinforcing wire 3 ·· extruded by the extruder is spirally wound along the outer peripheral surface of the intermediate portion of the foamed resin material 11 so that the auxiliary reinforcing wire 3 ·· is extruded. The auxiliary reinforcing wire 3... And the foamed resin material 11 are integrated by heat fusion using the heat of fusion. Thereby, the inner layer 1 in which the reinforcing core member 2 and the auxiliary reinforcing wire members 3 are wound around the outer peripheral surface side is formed.

And in the outer peripheral surface side of this inner layer 1, the strip | belt-shaped soft resin sheet material 40 is helically wound, and the edge parts adjacent to each other of the preceding soft resin sheet material 40 and the following soft resin sheet material 40 are mutually And the outer layer 4 is formed by bonding using heat fusion or an adhesive tape. Thereby, the reinforcing core material 2 and the auxiliary reinforcing wire 3... Are interposed between the inner layer 1 and the outer layer 4, and are continuous spirally between the outer peripheral surface of the inner layer 1 and the inner peripheral surface of the outer layer 4. A gap 5 is secured.

When the above duct hose is used for air supply / exhaust of an air conditioner, if noise generated by the blower enters the duct hose, the noise is propagated through the internal space 6 while the inner layer (foamed resin layer) 1 It is attenuated by colliding with the inner peripheral surface of the inner layer 1 and is attenuated by being guided to the inside of the inner layer 1 through the fine holes on the inner peripheral surface. Further, the noise propagating in the internal space 6 enters the sound absorbing hole 10 through the inner opening end 10a facing the internal space 6 and is attenuated by colliding with the hole wall surface of the sound absorbing hole 10. At the same time, it is led to the inside of the inner layer 1 through the fine holes on the wall surface of the hole and is attenuated. Further, the noise that has entered the sound absorbing holes 10... Enters the gap 5 from the outer opening end 10 b facing the gap 5, and the outer peripheral surface of the inner layer (foamed resin layer) 1 and the flexible outer layer The soft resin layer 4 is attenuated by colliding with the inner peripheral surface of the inner layer 4 and is attenuated by being guided into the inner layer 1 through the fine holes on the outer peripheral surface of the inner layer 1. Furthermore, it is assumed that the sound absorbing holes 10... Of the inner layer 1 constitute openings and the gap 5 constitutes a cavity, respectively, and exhibit the same function as the Helmholtz resonator. In this case, when noise is incident on the sound absorption holes 10..., The air in the sound absorption holes 10... Vibrates violently, and the sound is generated by friction between the air in the sound absorption holes 10 and the hole wall surface of the sound absorption holes 10. Energy is converted into thermal energy, and noise is attenuated. For these reasons, noise that has entered the duct hose is silenced before reaching the indoor opening of the duct hose.

As described above, in the duct hose described above, a plurality of sound absorbing holes 10... Are formed in the inner layer 1, and the gap portion 5 is formed between the inner layer 1 and the outer layer 4 to propagate through the inner space 6. Noise can be guided to the gap 5 through the sound absorbing holes 10. As a result, noise can be caused to collide with the outer peripheral surface of the inner layer 1 and the inner peripheral surface of the outer layer 4 to be attenuated, and the sound absorption performance can be significantly improved while having a simple structure.

Moreover, the sound absorbing holes 10... In the inner layer 1 need only communicate at least the internal space 6 and the gap 5, and can obtain good sound absorbing performance even if the number is reduced or the size is reduced. Since it can do, the strength reduction of the inner layer 1 can be suppressed and the shape retention property of a hose can be maintained favorable. In addition, since an air layer is formed by the gap 5 between the inner layer 1 and the outer layer 4 and an air heat insulating effect is obtained, the heat insulating performance of the hose can be improved.

FIG. 5 shows a modification of the duct hose according to the first embodiment. In this duct hose, the inner opening ends 10a of the plurality of sound absorbing holes 10 in the inner layer 1 are covered with a breathable thin film 1a that is part of the inner surface of the inner layer 1, The sound absorbing holes 10 are communicated with the internal space 6 through the ventilation holes of the thin film 1a. That is, the sound absorbing holes 10 are formed so as not to penetrate the inner layer 1 in the hose radial direction and leave the thin film 1a on the inner peripheral surface side of the inner layer 1.

Thereby, the inner peripheral surface of the inner layer 1 can be maintained in a substantially smooth state with almost no unevenness, and the ventilation resistance at the time of air supply and exhaust can be further reduced. In addition, as the thin film having air permeability, the inner opening ends 10a of the plurality of sound absorbing holes 10 formed through the inner layer 1 are covered so as to cover the inner peripheral surface of the inner layer 1 in a cylindrical shape. It may be a non-woven fabric or a woven fabric.

(Second Embodiment)
In the duct hose according to the second embodiment of the present invention, as shown in FIGS. 6 to 8, the reinforcing core member 2 is formed in a substantially T-shaped cross section including a horizontal piece 21 and a vertical piece 22. And the elastic spacer 50 which pushes the outer layer 4 in the hose diameter outward direction is attached to the outer peripheral surface of the horizontal piece 21 of this reinforcing core material 2.

The elastic spacer 50 is made of, for example, foamed polyethylene resin or the like, is wider than the horizontal piece 21 of the reinforcing core 2 and is formed in a substantially rectangular shape with a thickness of about 3 mm so as to cover the horizontal piece 21. Thus, it is spirally wound along the outer peripheral surface of the horizontal piece 21. In addition, the joining part 41 of the edge parts which adjoin each other of the soft resin sheet material 40 in the outer layer 4 is arrange | positioned directly on the elastic spacer 50, and is adhere | attached with the adhesive tape which is not shown in figure with respect to the elastic spacer 50. ing.

Thus, instead of the rising piece 23 of the reinforcing core material 2, the outer layer 4 is pushed in the hose diameter outward direction by the wide elastic spacer 50, so that the inner layer 1 is interposed between the outer peripheral surface and the inner peripheral surface of the outer layer 4. In addition, it is possible to more reliably form the gap 5 in which the height in the hose radial direction is sufficiently secured, and to further improve the sound absorption performance and the heat insulation performance. In addition, the flexibility of the hose can be improved. Other configurations and operational effects are the same as those of the first embodiment, and members having the same functions as those of the first embodiment in FIGS. 6 to 8 are denoted by the same reference numerals.

FIG. 9 shows a modification of the duct hose according to the second embodiment. In this duct hose, the inner opening ends 10a of the plurality of sound absorbing holes 10 in the inner layer 1 are covered with a breathable thin film 1a that is part of the inner surface of the inner layer 1, The sound absorbing holes 10 are communicated with the internal space 6 through the ventilation holes of the thin film 1a. That is, the sound absorbing holes 10 are formed so as not to penetrate the inner layer 1 in the hose radial direction and leave the thin film 1a on the inner peripheral surface side of the inner layer 1.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, as shown in FIG. 10 or FIG. 11, the shape and size of the sound absorption holes may be appropriately changed to widely mute noises in different frequency bands. In addition, the auxiliary reinforcing wire may be eliminated as long as the void portion can be secured only by interposing the reinforcing core material between the inner layer and the outer layer. Furthermore, in the above embodiment, a reinforcing core material having a substantially cross-shaped cross section or a reinforcing core material having a substantially T-shaped cross section with an elastic spacer is used. However, if a gap can be secured, FIG. As shown in FIG. 4, a reinforcing core material having a simple T-shaped cross section that does not include a rising piece or an elastic spacer may be used, or a reinforcing core material having other shapes may be used.

1 .... Inner layer, 1a ... Thin film, 2 .... Reinforcement core, 3 .... Auxiliary reinforcing wire, 4 .... Outer layer, 5 .... Gap, 6 .... Internal space, 10 .... Sound absorption hole, 10a ... Inner opening end, 10b .. Outer opening end, 11 .. Foamed resin material, 21 .. Horizontal piece, 22 .. Vertical piece, 23 .. Standing piece, 40 .. Soft resin sheet material, 50 .. Elastic spacer

Claims

By providing a cylindrical outer layer (4) via a reinforcing core (2) on the outer peripheral surface side of the inner layer (1) made of a cylindrical foamed resin layer, the outer peripheral surface and the outer layer of the inner layer (1) ( 4) A gap (5) is formed between the inner peripheral surface and a plurality of sound absorbing holes (10) in communication with the internal space (6) through which gas flows are formed in the inner layer (1). The outer opening end (10b) on the outer peripheral surface side of the inner layer (1) in the sound absorbing holes (10) is made to face the gap (5). hose.
2. The duct hose according to claim 1, wherein the sound absorbing holes (10) have a cross-sectional shape in which a hole diameter increases from an inner peripheral surface side to an outer peripheral surface side of the inner layer (1).
In the sound absorbing holes (10), the inner opening end (10a) on the inner peripheral surface side of the inner layer (1) faces the inner space (6) so that the sound absorbing holes (10), 3. The duct hose according to claim 1 or 2, wherein the is communicated with the internal space (6).
In the sound absorbing holes (10), the inner opening end (10a) on the inner peripheral surface side of the inner layer (1) is covered with a breathable thin film (1a), so that the sound absorbing holes ( The duct hose according to claim 1 or 2, wherein 10) is communicated with the internal space (6) through a vent of the thin film (1a).
The inner layer (1) is formed by spirally winding a band-shaped foamed resin material (11) in which the sound absorbing holes (10) are formed, and the preceding foamed resin material (11) and the subsequent foamed resin material ( 11) adjacent edge portions of each other are joined together via the reinforcing core material (2) formed by spirally winding along the edge portions, and the reinforcing core material (2) A horizontal piece (21) straddling between the outer peripheral surfaces of the adjacent edge portions, and a vertical piece extending from the horizontal piece (21) in the hose radial inward direction and entering between the adjacent edge portions ( 22). A duct hose according to any one of claims 1 to 4.
The said reinforcing core material (2) is equipped with the standing piece (23) extended in the hose diameter outer direction from the said horizontal piece (21), and pushing the said outer layer (4) in the hose diameter outer direction. Duct hose.
The duct hose according to claim 5, further comprising an elastic spacer (50) attached to the outer peripheral surface of the lateral piece (21) of the reinforcing core member (2) and for pushing the outer layer (4) outward in the hose diameter direction.
The auxiliary reinforcing wire (3) is spirally wound around the outer peripheral surface side of the inner layer (1) along the middle portion of the foamed resin material (11). Duct hose.
The outer layer (4) is formed by spirally winding a strip-shaped soft resin sheet material (40), and adjacent edges of the preceding soft resin sheet material (40) and the subsequent soft resin sheet material (40). The duct hose according to any one of claims 1 to 8, wherein the parts are joined together.
The duct hose according to any one of claims 1 to 9, wherein the reinforcing core member (2) and the outer layer (4) are in an unbonded state.
The duct hose according to any one of claims 1 to 10, wherein a shape or a size of a part or all of the plurality of sound absorbing holes (10) is different.