JPH09210291A - Heat insulating pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulating pipe lightening weight, having both good heat insulation and sound absorptivity, reducing fluid resistance of a duct, decreasing a work amount in a jobsite, having easily supporting rigidity and with economical efficiency. SOLUTION: A heat insulating pipe 10 is constituted by an inner pipe 12 comprising foaming material layers 16, 18 and a ventilating film layer 20 layered inside the foaming material layer and an outer pipe 14 provided in the outside of the inner pipe to have rigidity larger than its rigidity to be formed by a flexible corrugated pipe unit having an internal wall surface alternately protruding/hollowing in a direction crossing with an axial core. The foaming material layer of the inner pipe respectively has an independent bubble foaming material layer 16 having a continuous bubble foaming material layer 18 in the inside and elasticity in the outside. The independent bubble foaming material layer, by its elasticity, is advanced into a recessed part of the outer pipe internal wall surface, in this way, the inner/outer pipe is mutually engaged, integrality of a heat insulating pipe is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating pipe, and more particularly to a heat insulating pipe most suitable as a material for ventilation and blower ducts of an air conditioner or an air conditioner for a building, particularly an air conditioner for an ordinary house or an air conditioner. It is about pipes.

[0002]

2. Description of the Related Art Ventilation or blower ducts provided in air-conditioning facilities or air-conditioning facilities of buildings are a type of air pipe for sending cold or warm air indoors. In order to retain the heat, heat insulation is required to prevent heat from flowing in and out between the air and the outside. Conventionally, various types of ducts with heat insulating properties have been used as ventilation and blower ducts, the main ones of which are classified as iron plate ducts, spiral ducts, glass wool ducts, flexible ducts and heat insulation ducts. ing.

The iron plate duct 50 is the most commonly used heat insulating duct, and as shown in FIG.
It is composed of a duct body 52 and a heat insulating layer 54. The duct main body 52 is formed by cutting and processing an iron plate such as a zinc iron plate at a duct manufacturing factory or a duct laying site, and assembling it as a tubular body having a shape such as a cylindrical shape or a rectangular tube shape (displayed as a square tube shape in FIG. 10). The heat insulating layer 54 is formed by attaching the assembled duct body 52 along a predetermined path, and then winding glass wool or rock wool around the duct body 52 at that location. Insulating layer 54 to duct body 52
In order to fix the heat insulating layer 54 on the outside, the outside of the heat insulating layer 54 is wound with an adhesive tape 56A made of aluminum glass cloth, and the abutting corners of the heat insulating layer 54 in the longitudinal direction are attached with an adhesive tape 56B.

As shown in FIG. 11, the spiral duct 57 has a tubular body 58 formed by winding narrow steel strips in a spiral shape while partially overlapping them with each other in a spiral shape, and the tubular body 58 along a predetermined path. And a heat insulating layer 60 formed by winding glass wool around the outer periphery of the tube body 58 at that location. In order to fix the heat insulating layer 60 to the tubular body 58, the outer circumference of the heat insulating layer 60 is wrapped with an adhesive tape 62A made of aluminum glass cloth, and the longitudinal abutting edges of the heat insulating layer 60 are pasted together with an adhesive tape 62B. Has been done.
In addition, as one type of the spiral duct 57, there is also one in which heat insulating fibers are planted on the outer peripheral surface of the tubular body by electrostatic coating to prevent dew condensation and achieve a heat insulating effect.

As shown in FIGS. 12 and 13, the glass wool duct 63 is formed by molding the rectangular tubular duct main body 64 or the cylindrical duct main body 68 with a glass wool molding plate and bringing the molded duct to the installation site. It is a duct formed by adhering the edges of the plates with adhesive tapes 66 and 70 made of aluminum glass cloth. Also, for non-straight pipe parts such as bent parts and branch parts, by cutting and pasting the molding plate on site,
It is made individually.

The flexible duct 77 is shown in FIG.
As shown in FIG. 3, a strip 80 such as a non-woven fabric or a glass cloth is wound around the steel wire coil 78 to form a tubular body, glass wool 82 is wound thereon as a heat insulating material, and a vinyl sheet or a vinyl tube is further placed thereon. It is a duct that is wound with an exterior material 84 such as the above.

The heat-insulating duct 85 shown in FIGS. 15 (a) and 15 (b) was developed as a duct material for ventilation or blower for general houses. A non-woven fabric 88 is wound around a steel strip coil 86 to form a pipe. Forming a body, and then sequentially forming narrow strips of urethane foam 90, vinyl tape or PVC
It is a duct manufactured by winding a sheet 92, a polyethylene foam 94, a vinyl tape or a PVC sheet 96.

[0008]

However, as described in detail below, the conventional duct has problems associated with its material and structure. First, in the iron plate duct 50 of FIG. 10, it is necessary to perform on-site heat insulation work by winding a heat insulating material around the duct body, and in order to adjust the duct length, iron plate cutting, sheet metal processing and welding work are performed on site. It is necessary to do. For this reason, there are many on-site works that require high skill, and there is a problem that it is difficult to rationalize the duct laying work. In addition, when cutting glass wool or rock wool, there is a work environment problem in that cutting waste is scattered as powder and irritates the operator's skin or is inhaled with breathing. Further, the spiral duct 57 of FIG. 11 is used as, for example, a cooling duct because of the problem that heat insulation work is required to attach a heat insulating material at the site and the low heat insulation performance in the flocked type, and the temperature lower than that of the outside. There was a problem that dew condensation occurred on the duct when cold air was passed. Furthermore, the iron plate duct 5
In the case of 0 and the spiral duct 57, when sound absorption is required, there is a problem that a member such as a flexible duct and a chamber having a sound absorbing property is additionally required.

Further, the glass wool duct 63 shown in FIGS. 12 and 13 is accompanied by a work environment problem caused by the above-mentioned cutting of glass wool. In addition, a worker with skill and experience is required for the work of joining ducts with adhesive tape or adhesive, and when forming bent parts of ducts, elbow parts etc. are manufactured at the duct laying site. It was difficult to rationalize on-site construction. In addition, there is an economical problem that the material cost increases.

Since the flexible duct 77 of FIG. 14 is constructed integrally with a heat insulating material, it has the advantages that it does not require heat insulation work on site, and that it has sound absorption and flexibility. However, at the same time, since the duct itself is poor in rigidity, it is easy for the duct to be deformed or crushed at the supporting portion or bending portion of the duct, and it is difficult to form a long duct, for example, a duct of 5 m or more,
Also, there is a problem that the material cost is high and it is economically disadvantageous.

Since the heat insulating duct shown in FIG. 15 is integrally formed with a heat insulating material like the flexible duct 77 shown in FIG. 14, there is no need to perform heat insulating work on site, and the sound absorbing property and flexibility can be improved. Although it has the advantage that it is provided, it is hung with a hanger etc. because the outer peripheral part of the duct is made of foam such as urethane foam and a soft exterior material such as vinyl tape and is soft and easily deformed. There was a problem that the duct was deformed or crushed at the place or the place supported by the beam. Further, since the tubular body and the heat insulating pipe are manufactured by rolling the strip-shaped material in a spiral shape, there is a problem that the manufacturing cost increases. In addition, in order to cut the heat insulating duct at the site, it is necessary to cut the spirally wound steel strip with a tool such as gold scissors, so it takes time and labor for the duct work. there were.

By the way, a duct laid inside the building,
In particular, the ventilation and blower ducts installed in air-conditioning equipment or air-conditioning equipment of general houses should be laid in a narrow space such as (1) attic on the second floor or between the ceiling on the first floor and the floor on the second floor. Therefore, the workability is good, (2) the fluid resistance is low due to the necessity of laying a narrow duct in a narrow space, and (3) the sound absorption performance in addition to the heat insulation performance for blocking the noise generated by the flow of the fluid. (4) The sites are dispersed in each place, and the amount of duct work at each site is small, so the type of work required at the site and the amount of work required are as small as possible. It is necessary to have the flexibility to bend freely along the path without the need for a separate part for use, and the rigidity to be easily supported, and (6) low cost. .

However, as described above, the conventional heat-insulating ducts have problems associated with their respective materials and structures. Therefore, the above-mentioned heat-insulating ducts for indoor use, especially as duct materials for general houses, are required. There is no duct that can meet the requirements. Therefore, an object of the present invention is to provide a lightweight, heat-insulating pipe having rigidity that is easy to support, good heat insulation and sound absorption, duct fluid resistance is small, workability is good, and economical. is there.

[0014]

In order to achieve the above object, a heat insulating pipe according to the present invention comprises an inner pipe comprising a foam layer and a breathable film layer laminated inside the foam layer, A foam body for the inner pipe, which is provided outside the pipe, has a rigidity higher than that of the inner pipe, and is composed of an outer pipe made of a flexible corrugated pipe having inner wall surfaces that are alternately concave and convex in a direction intersecting the axis. The layer is characterized by having an open cell foam layer on the inside and a closed cell foam layer on the outside.

The outer tube is composed of a corrugated tube having higher rigidity and flexibility than the inner tube. This allows
The outer tube has rigidity so as not to be deformed against its own weight due to suspension support by a suspender or beam support to facilitate supporting the heat insulating tube and protect the inner tube against mechanical force from the outside, It is also flexible and can be laid freely along the path without the need for a separate bend part. The inner tube may be inserted loosely with respect to the outer tube by reducing the outer diameter of the inner tube, which may be convenient for replacing the inner tube. Conversely, the closed cell foam of the inner tube may be used. It is also possible that the layer projects into the recess of the inner wall surface of the outer tube and is hooked on the inner wall surface, and the inner tube and the outer tube are engaged with each other to ensure the integrity of the heat insulating tube. When the inner tube and the outer tube are engaged with each other to secure the integrity of the heat insulating tube, it is desirable that the closed cell foam layer has elasticity. Further, in this case, it is not necessary that the outer circumference of the closed-cell foam layer protrudes into the recess of the inner wall surface of the outer tube over the entire circumference, and as long as the inner tube and the outer tube can engage with each other, only a part of the outer circumference. May project into the recess of the inner wall surface of the outer tube.

The outer tube is not particularly limited as long as it is formed of a flexible corrugated tube having rigidity higher than that of the inner tube and having inner wall surfaces which are alternately concave and convex in a direction intersecting with the axis. The shape may be a cylinder, an elliptic cylinder, a polygonal cylinder, or the like, and is preferably a cylinder. The corrugated shape is provided so that the tube wall of the outer tube is alternately convex and concave in a direction intersecting the axis, for example, in a direction orthogonal to each other. Even in the spiral continuous corrugated shape, individual ring (ring) -shaped shapes are obtained. It may be an independent wave. The dimensions of the pitch, crest width, trough width, height between crests, etc., of the individual corrugations of the corrugated shape are such that the closed-cell foam layer of the inner tube can project into the recess of the inner wall surface of the outer tube, and There is no limitation as long as it has flexibility and rigidity,
When drawing the inner tube into the outer tube, it is easier for the wave size to be smaller. The material of the outer tube is not particularly limited, moldability capable of molding a long outer tube by a continuous extrusion method, light weight,
From the viewpoint of corrosion resistance and workability such as cutting, plastic is preferable.

The shape of the inner tube is not particularly limited, and is cylindrical,
Any shape such as an elliptical shape, a polygonal cylinder shape, and a flat cylinder shape may be used. Further, the outer peripheral portion of the inner pipe may project into the concave portion of the inner wall surface of the outer pipe so that the inner pipe and the outer pipe are engaged with each other. The inner diameter of the inner tube is determined depending on the flow rate of the flowing fluid, for example, air, but the inner diameter of 50 mmφ to 200 mmφ is usually used. In order to make it easier to draw the inner pipe into the outer pipe, the outer peripheral length of the inner pipe is the same as the inner peripheral length of the outer pipe (the inner peripheral length at the convex portion of the inner surface of the outer pipe), or 0 to 5%. It is desirable to make it small.

The open-cell foam layer forming the inner layer of the inner tube and the closed-cell foam layer forming the outer layer of the inner tube are provided for imparting sound absorption and heat insulation to the heat insulating tube, respectively. . Since the open-celled foam has a heat insulating property in addition to the sound absorption performance, it may be possible to configure the inner tube with only the open-celled foam, but since the rigidity (strength of the waist) is poor, Difficult to mold into a tubular body and it is difficult to maintain its shape as a tubular body. On the other hand, closed-cell foam has excellent moldability, but its sound absorption is inferior to that of open-cell foam. I cannot satisfy my sexuality.

The breathable film layer has a smooth surface for reducing the fluid resistance of the fluid flowing in the inner tube, and has a large number of pores for communicating the fluid with the open-cell foam layer for absorbing sound. It is a film layer provided on a smooth surface. By allowing the fluid to communicate with the open-cell foam layer through the breathable film layer, low heat resistance and sound absorption are imparted to the heat insulating tube,
In addition, it is possible to suppress the quality deterioration of the open-cell foam layer due to the direct contact between the open-cell foam layer and the fluid.

The layer thicknesses of the open-cell foam layer and the closed-cell foam layer are determined on the basis of the necessary heat insulation performance and sound absorption performance, but in practice, they are each 5 to 5 regardless of the inner diameter of the inner tube.
A range of 20 mm is sufficient. The closed cell foam layer preferably has an expansion ratio of 20 to 40 times and a density of 25 to 50 kg / m ³ . On the other hand, the open-cell foam layer is
Foaming ratio is 20 to 60 times and density is 18 to 60 kg / m
^It is preferably in the range of ³ . Also, the tensile strength is 15-
40N / cm ^2, it is preferable to provide the strength of the compressive hardness 2.0~6.0N / cm ^2. When projecting into the concave portion of the inner wall surface of the outer tube, the open cell foam layer should have elasticity enough to project.

In the heat-insulating pipe according to the present invention, the inner pipe has a two-layer structure including an open-cell foam layer mainly providing sound absorption and a closed-cell foam layer mainly providing heat insulation. Therefore, the work of installing the heat insulating material on the site is not required, and it is not necessary to prepare another member for sound absorption or sound absorption, and the workability is good. Further, since the breathable film layer is provided on the inner peripheral surface, the fluid resistance is low. Since the heat-insulating pipe according to the present invention has flexibility, it can be freely laid along the route without the need for separate elbows, joints, and other parts, and an outer pipe with high rigidity can be provided. As it is equipped, laying work is easy.

The inner tube has a structure in which the closed-cell foam layer and the open-cell foam layer of the foam layer of the inner tube are integrally formed, and the inner tube forming the foam layer of the inner tube. In some embodiments, the open-cell foam layer and the outer closed-cell foam layer have a laminated structure composed of an independent open-cell foam and a closed-cell foam.

In the former embodiment, as will be described later, for example, a closed cell foam layer and an open cell foam layer are integrally formed by an electron beam irradiation method using a polyolefin resin as a material of the foam layer. Foam layers can be made.

In the case of the latter embodiment, that is, when the foam layer of the inner tube is formed of a laminated structure composed of independent open-cell foam and independent-cell foam, the closed-cell foam is For example, a foam having good heat insulating property such as polyethylene, EVA, polypropylene, etc., generally polyethylene foam is used. On the other hand, in the open-cell foam,
For example, a sound absorbing foam such as polyurethane, polyethylene, polyvinyl chloride, EVA, melamine, etc., generally polyurethane foam is used.

The breathable film layer is preferably a nonwoven fabric made of polyester, nylon, polypropylene or the like, more preferably a nonwoven fabric made of polyester or nylon from the viewpoint of heat resistance and durability. The basis weight is 30 to 100 g / m ^2.
Is desirable.

The method of manufacturing the heat insulating pipe is not limited, and for example, the outer pipe and the inner pipe may be separately molded, and then the inner pipe may be inserted into or pulled out from the outer pipe, and the heat insulating pipe according to the present invention may be manufactured. Can be manufactured. The outer tube is generally formed by extrusion of plastic. In order to form an inner tube in which the closed-cell foam layer and the open-cell foam layer are integrally formed, first, a plate-like body made of a foamable resin, for example, a polyolefin resin plate containing a foaming agent is formed. When the surface layer is irradiated with an electron beam to cause electron beam cross-linking and then foamed, the surface layer is a closed cell foam layer having elasticity and the inner layer is a foam plate made of a foam material having an open cell foam layer. be able to. By laminating the breathable film layer on the side of the open-celled foam layer of this foam plate, it is possible to form a laminated plate necessary for molding the inner tube.

On the other hand, in order to form an inner tube having a laminated structure consisting of independent open-cell foams and independent-cell foams, first, a breathable film and:
An open-cell foam plate and a closed-cell foam plate are laminated in this order to form a laminated structure, which is then cut into a predetermined width to form a laminated plate.

Further, a plurality of parallel folds (or folds) extending in the longitudinal direction of the laminate are provided on the surface of the laminated plate on the side of the breathable film, and the folds are arranged in a direction orthogonal to the folds, and An inner pipe can be formed by winding the laminate so that the breathable film layer is the inner peripheral surface, butting both edges of the laminate, and then joining the butting edges. Then, the inner tube is drawn into the outer tube obtained by extrusion molding the plastic to complete the heat insulating tube.

In forming the laminate, the air-permeable film layer, the open-cell foam layer and the closed-cell foam layer are bonded to each other by a thermal bonding method such as a frame lamination method or an infrared lamination method. It can be performed by a method such as a dry lamination or a bonding method using an adhesive such as bonding. For economical bonding, a thermal bonding method in which the surface of a thermoplastic material such as polyurethane or polyethylene is melted to form a fusion layer.

In a preferred embodiment of the present invention, a plurality of fold-shaped grooves formed so as to allow the breathable film layer to bite into the foam layer extend on the inner peripheral surface of the inner pipe in the longitudinal direction of the heat insulating pipe. It is characterized by doing. When a laminated plate including a breathable film layer and a foam layer is wound to form an inner tube, the foam layer is wound with a plurality of crease-shaped grooves (folds) as bending lines. An inner tube having a smooth cross-sectional profile is formed, and fluid resistance is reduced.

The number of folds is preferably equal to or greater than the quotient obtained by dividing the difference between the outer peripheral length of the inner pipe and the inner peripheral length by the thickness of the inner pipe, and the distance between the folds is 8 to 40 mm. It is preferably in the range. In addition, the method of forming the folds can be formed by pressing the creasing jig at a depth shallower than the thickness of the inner pipe. Instead of the fold line, a cut may be formed in the breathable film layer and the foam layer.

[0032]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Example 1 FIG. 1 is a perspective view of Example 1 of the heat insulating pipe according to the present invention,
2 is a partial cross-sectional side view of the heat insulating pipe shown in FIG. As shown in FIG. 1, the heat insulating pipe 10 of the present embodiment includes an inner pipe 12 made of a substantially cylindrical pipe body having an inner diameter of about 95 mm and an outer diameter of about 115 mm, and an inner pipe 12 outside the inner pipe 12. Covered, the inner diameter is 115 mm, the outer diameter is 125 mm, and the wall thickness is 0.
The outer tube 14 is a corrugated tube of 5 to 0.8 mm.

The inner tube 12 is a cylindrical outer cylinder layer 16 having a thickness of about 5 mm, which is formed of a closed cell foam having good heat insulation properties, and a sound absorbing member inside the outer cylinder layer 16 independently of the outer cylinder layer 16. A cylindrical inner cylinder layer 18 having a thickness of about 5 mm, which is formed of a good open-cell foam and forms a laminated structure with the outer cylinder layer 16, and a breathable film layer laminated on the inner peripheral surface of the inner cylinder layer 18. 20 and 20.

The closed cell foam forming the outer cylinder layer 16 has a foaming ratio of 30 times, a density of 30 kg / m ³ , a tensile strength of 17.6 N / cm ² , and a compression hardness of 2.9 N / cm ² . A flammable closed-cell polyethylene foam is used, and the pasting surface is subjected to a primer treatment or a corona treatment so as to facilitate the pasting process with the inner cylinder layer 18. Also,
Skin layers are provided on both sides of the closed-cell foam forming the outer cylinder layer 16 in order to impart elasticity. on the other hand,
The open-celled foam forming the inner cylinder layer 18 is made of flame-retardant open-celled polyurethane foam having a foaming ratio of 30 times and a density of 30 kg / m ³ . For the breathable film layer 20, a breathable and flame-retardant non-woven fabric made of polyester having a basis weight of 50 g / m ² is used. Instead of the polyester non-woven fabric, a flame-retardant or self-extinguishing nylon non-woven fabric may be used. It is also effective to apply or impregnate an antibacterial agent in order to make it difficult for mold and other bacteria to generate. The breathable film layer 20 of the inner tube 12 has eighteen creases 22 having a depth of 2 to 4 mm in such a manner that the breathable film layer 20 is drawn into the inner tubular layer 18, and the heat insulating tube 10 is provided at substantially equal intervals. Is formed in the longitudinal direction.

The outer pipe 14 is a commercially available hard vinyl flexible corrugated pipe for drainage pipes made by continuous extrusion vacuum forming, and as shown in FIG. 2 (a), the pitch P is 8 mm. ,
The peak height H is 5 mm, the peak width W ₁ is 4.5 mm, and the valley width W ₂ is 2.
It has a spiral corrugation with a dimension of 5 mm and is formed by alternately corrugating the tube wall in the direction orthogonal to the axial direction. Outer tube 14
Inside, the outer peripheral portion of the outer tube layer 16 of the inner pipe 12 is the outer pipe 14
Projecting into the recess 21. As a result, the inner pipe 12 and the outer pipe 14 are engaged with each other to maintain the integrity of the heat insulating pipe 10. Since the outer pipe 14 of the present embodiment has a small corrugated pitch, when the inner pipe 12 is pulled in, the contact area between the inner pipe 12 and the inner convex portion 23 of the outer pipe 14 becomes small, and therefore the pull-in resistance becomes small. It becomes easy to pull in. Further, since the tube wall of the outer tube 14 is thin, it is lightweight and has good flexibility.

In this embodiment, the inner tube 12 is cylindrical, but the inner tube 12 has a shape such that the maximum outer dimension L of the outer shape of the inner tube 12 (see FIG. 3) is the inner diameter D of the outer tube 14 (see FIG. 2). As long as the inner tube 12 is slightly larger than the inner tube 12 and is retained by the outer tube 14 (see (a)), an elliptic tube shape as shown in FIG. 3 (a), a hexagonal tube shape as shown in FIG. The polygonal cylinder shape may be a flat cylinder shape as shown in FIG.

With the above structure, the heat insulating pipe 10 of the present embodiment.
Has the following features. (1) Since the inner tube 12 and the outer tube 14 are formed of plastic foam and plastic, respectively, they are lightweight,
Moreover, it has good on-site workability such as cutting work and connecting work.
(2) The inner tube 12 is composed of two layers of an open-celled foam having a high sound absorbing property and a closed-cell foam having a high heat insulating property, and the open-celled foam has a heat insulating tube 10 through a breathable film layer.
Since it communicates with the fluid flowing therein, it has both sound absorbing properties and heat insulating properties, and furthermore, deterioration of the quality of the open-cell foam is prevented. (3) Since the breathable film layer is provided on the fluid contact surface of the heat insulating tube 10, the fluid resistance is low. (4) Since the outer pipe 14 has appropriate rigidity and flexibility, it is easy to lay and has high mechanical strength against external mechanical force. (5) Engagement of the inner pipe 12 and the outer pipe 14 ensures the integrity of the heat insulating pipe 10.

Manufacturing Method of Insulating Pipe of Embodiment 1 A manufacturing method of the insulating pipe 10 of Embodiment 1 will be briefly described below. 1. Step of Forming Laminated Plate First, as shown in FIG. 4, a nonwoven fabric 24, an open-cell polyurethane foam 25, and a closed-cell polyethylene foam 26 are sequentially laminated and laminated, and then the outer peripheral length of the inner tube 12 is obtained. The width is cut to a width to form a long laminated plate 28.

2. Inner tube forming step The step of forming the laminated plate into an inner tube is performed using a forming apparatus as shown in FIG. Here, FIG. 5 is a schematic diagram of an example of a manufacturing apparatus for the inner pipe 12, and FIG. 6 is a schematic diagram of a molding die for molding the laminated plate into the inner pipe. The laminated plate 28 is introduced into the manufacturing apparatus 29 with the non-woven fabric 24 on the upper side, and while being placed on the feed roller 30 and run, the crease forming roller 31 causes the surface of the non-woven fabric 24 to be orthogonal to the width direction of the laminated plate 28. Folds 32 (see FIG. 6) are formed at a pitch of 20 mm.

Next, the upper side of the laminated plate 28, that is, the nonwoven fabric 2
The four sides are heated by the hot air heater 36 to bend the laminated plate 28, and the laminated plate 28 is introduced into the molding die 33. As shown in FIG. 6, both side edges of the laminated plate 28 are abutted to form the cylindrical inner tube 12. The laminated plate 28 is molded into the cylindrical inner tube 12, and at the same time, the abutting side edges of the laminated plate 28 are heated and fused by the heater 34 for heat fusion at the entrance of the molding die 33. Next, the inner pipe 12 that has passed through the molding die 33 is continuously drawn out by the take-out device. The take-up device is arranged above and below the inner pipe 12 to draw the inner pipe 12 from the molding die 33, and guides the inner pipe 12 when the inner pipe 12 is pulled out and the endless belt 38 that runs in close contact with the inner pipe 12. For this purpose, guides 40 provided above and below the endless belt 38 are provided. By the cooperation of the endless belt 38 and the guide 40, the take-out device can take out the inner tube 12 from the forming die 33. At the time of manufacturing the inner pipe 12, an excess portion on the inner side of the inner pipe caused by the difference between the outer diameter and the inner diameter of the inner pipe 12 bites into the inner tubular layer 18 along the fold 32, and the inner peripheral wall of the inner pipe 12 A fold groove 22 (see FIGS. 1 and 2) is formed.

3. Inserting Step Next, the inner tube 12 is inserted into or retracted from the outer tube 14 to form the heat insulating tube 10 shown in FIG. When retracted, the inner tube 12 is deformed to facilitate insertion into the outer tube 14 if necessary. In addition, inserting the inner tube 12 into the outer tube 14,
At the time of pulling in, if a lubricant such as water is applied to the outer peripheral side wall of the inner tube 12, insertion or pulling in becomes easy. As the inner tube 12 is drawn into the outer tube 14, the outer peripheral portion of the outer tube layer 16 of the inner tube 12 projects into the inner recess of the outer tube 14 to engage the inner tube 12 and the outer tube 14 and to provide integrated heat insulation. A tube 10 is formed. However, if the outer diameter of the inner pipe 12 is too small with respect to the inner diameter of the outer pipe 14, for example, the outer diameter of the inner pipe 12 is 105 mm.
In this case, the gap between the inner pipe 12 and the outer pipe 14 becomes large, and the elasticity of the inner pipe 12 alone cannot lock the inner pipe 12 to the inner wall of the outer pipe, resulting in insufficient fixation of the inner pipe 12.

When forming the inner tube 12, as shown in FIG. 3A, the inner diameter is equal to or shorter than the inner diameter of the outer tube 14, for example, 11
An elliptic cylindrical inner tube 12 having a short diameter of 0 to 115 mm (-5 to 0%) and an inner diameter of the outer tube 14 which is equal to or longer than the inner diameter, for example, 115 to 120 mm, is formed, and is formed into the outer tube 14. You can pull in. When the inner tube 12 is pulled into the outer tube 14, the long diameter portion of the outer peripheral portion of the inner tube 12 contacts the inner wall surface of the outer tube 14 and receives a compressive force from the outer tube 14. At this time, the long diameter portion of the outer tube layer 16 bites into the recess of the inner wall surface of the outer pipe 14 due to its elasticity, so that the inner pipe 12 moves in the long diameter direction I-I of the inner pipe 12 as shown in FIG. Engage with 14. Similar to the above-mentioned example of the elliptic cylinder, the polygonal cylinder shown in FIG.
The inner tube 12 can be locked and fixed to the outer tube 14 even in the flat tubular shape shown in FIG.

The heat insulating pipe 10 can be manufactured by extruding the outer pipe 14 onto the outer periphery of the inner pipe 12 instead of pulling the formed inner pipe 12 into the outer pipe 14.

Embodiment 2 FIG. 8 is a cross-sectional view of Embodiment 2 of the heat insulating pipe according to the present invention. The heat insulating pipe 41 of the present embodiment has the same configuration as the heat insulating pipe 10 of the first embodiment, except that the inner pipe 42 has a different configuration from the inner pipe 12 of the heat insulating pipe 10 of the first embodiment. There is. In the first embodiment, the inner pipe 12 is composed of the outer cylinder layer 16 and the inner cylinder layer 18.
In contrast to being formed by a laminated structure of layers, the second embodiment
The foam layer of the inner tube 42 has a density of 30%, as shown in FIG.
10 mm thickness made of polyethylene foam of kg / m ³
It is formed by one foam cylinder 43. The foam cylinder 43 includes an outer closed-cell foam layer 44 having a thickness of about 5 mm,
It is composed of an inner open-cell foam layer 45 having a thickness of about 5 mm. The inner surface of the open-cell foam layer 45 has Example 1
Similarly to the above, a breathable film layer 20 made of polyester having a basis weight of 50 g / m ² is laminated, and 18 folding grooves 22 are formed.
Are formed in the longitudinal direction of the heat insulating pipe 10 at substantially equal intervals. With the above configuration, the heat insulating pipe 41 of the second embodiment has the same features as the heat insulating pipe 10 of the first embodiment.

Manufacturing Method of Insulating Pipe of Embodiment 2 The manufacturing method of the insulating pipe of Embodiment 2 will be briefly described below.
First, both sides of a polyethylene resin plate containing a crosslinking agent and a foaming agent are irradiated with an electron beam to cause electron beam crosslinking in a layer near the irradiation surface. Next, when foamed, a layer in the vicinity of the electron beam irradiation surface of the polyethylene resin plate becomes a closed cell foam layer 44, and an inner layer becomes an open cell foam layer 45 to form a composite foam. The foam composite was foamed 40 times, and the total thickness of the closed-cell foam layer and the open-cell foam layer was 12 mm. This was sliced at the center to halve, and a pair of the inner open-cell foam layer and the outer closed-cell foam layer was used. Then, the nonwoven fabric 46 is attached to the open-cell foam layer 45, and further cut into a width corresponding to the outer peripheral length of the inner tube 42 to form a long laminated plate 49 as shown in FIG. Next, the laminated plate 49 is processed in the same manner as in the method of manufacturing the heat insulating tube 10 of the first embodiment to form the inner tube 42, and the inner tube 42 is drawn into the outer tube 14 to manufacture the heat insulating tube 41.

[0046]

According to the present invention, a heat insulating pipe is formed by an inner pipe made of a foam layer and an air permeable film layer inside thereof, and an outer pipe made of a flexible corrugated pipe having a rigidity higher than that of the inner pipe. Configure and
Lightweight by constructing the foam layer of the inner tube from the inner open-cell foam layer and the outer closed-cell foam layer having elasticity, and projecting the closed-cell foam layer into the recess of the inner wall surface of the outer tube With good heat insulation and sound absorption, low fluid resistance, low work load on site, rigidity and integrity, easy to support, and economical economical heat insulation pipe is realized. By using the heat insulating pipe according to the present invention as the duct material, (1) the work of installing the heat insulating material on site is not required, and the work amount of costly field work can be reduced. (2)
There is no need to separately prepare a sound absorbing member or a member for absorbing sound, and material management becomes easy. (3) Since the heat insulating pipe has appropriate rigidity and flexibility, the laying work is easy, and the heat insulating pipe is not deformed after the duct construction to increase the fluid resistance. (4) Since it is small, lightweight, has low fluid resistance, and is economical, it is optimal as a duct material for ventilation and blower for general houses.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a heat insulating pipe according to a first embodiment.

2 (a) and 2 (b) are a partial cross-sectional side view and a cross-sectional view, respectively, of the heat insulating tube of FIG.

3 (a), (b) and (c) are cross-sectional views of another example of the inner tube.

FIG. 4 is a perspective view of a laminated plate for forming an inner tube.

FIG. 5 is a schematic diagram showing a manufacturing apparatus inside a heat insulating pipe of Example 1.

FIG. 6 is a schematic diagram illustrating the function of a molding die.

FIG. 7 is a conceptual diagram illustrating engagement between an inner pipe and an outer pipe.

FIG. 8 is a transverse cross-sectional view showing a configuration of a heat insulating pipe according to a second embodiment.

FIG. 9 is a perspective view of an inner pipe forming laminated plate of a heat insulating pipe according to a second embodiment.

FIG. 10 is a perspective view of a conventional heat insulating tube.

FIG. 11 is a perspective view of another conventional heat insulating tube.

FIG. 12 is a perspective view showing still another conventional heat insulating tube.

FIG. 13 is a perspective view showing still another conventional heat insulating tube.

FIG. 14 is a perspective view showing still another conventional heat insulating tube.

15 (a) and 15 (b) are respectively an exploded view and a longitudinal sectional view showing still another conventional heat insulating pipe.

[Explanation of symbols]

 10 Example 1 of heat insulation pipe according to the present invention 12 Inner pipe 14 Outer pipe 16 Outer cylinder layer 18 Inner cylinder layer 20 Breathable film layer 21 Recessed portion 22 Groove 23 Convex portion 24 Nonwoven fabric 25 Open cell polyurethane foam 26 Closed cell polyethylene Form 28 Laminated plate 29 Manufacturing apparatus 30 Feed roller 31 Fold forming roller 32 Fold 33 Forming die 34 Heat fusion heater 36 Hot air heater 38 Endless belt 40 Guide 41 Example 2 of heat insulating pipe according to the present invention 42 Inner pipe 43 Foaming Body cylinder 44 Closed-cell foam layer 45 Open-cell foam layer 46 Nonwoven fabric 49 Laminated plate

Claims (3)

[Claims] 1. An inner tube composed of a foam layer and a breathable film layer laminated inside the foam layer, and an outer tube provided outside the inner tube, having a rigidity higher than that of the inner tube and intersecting an axial center. It is composed of an outer tube consisting of a flexible corrugated tube having inner wall surfaces that are alternately concave and convex in the direction, and the foam layer of the inner tube has an open cell foam layer on the inside and a closed cell foam layer on the outside. An adiabatic tube characterized by having each. 2. The heat insulating pipe according to claim 1, wherein the inner open-cell foam layer and the outer closed-cell foam layer forming the foam layer of the inner tube are independent of each other. And a heat insulating tube having a laminated structure made of a closed cell foam. 3. A fold-shaped groove formed so as to allow the breathable film layer to bite into the foam layer, which extends in the longitudinal direction of the heat insulating pipe on the inner peripheral surface of the inner pipe. The heat insulating pipe according to 1 or 2.