JPH10238667A - Heat insulation pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulation pipe which is easy in manufacture and excellent in quality, has the stable structure free from any ejection or pull-out of the heat insulation material, and prevent the generation of condensation. SOLUTION: An inner pipe 1 is formed by spirally winding the hard vinyl chloride resin strip in the semi-molten condition, a strip-shaped heat insulation material 2' made of foamed polyethylene resin which is non-adhesive or difficult in adhesion to the inner pipe 1 made of hard vinyl chloride resin is similarly and spirally wound over the inner pipe 1 to form a heat insulation layer 2, and inner and outer end parts at the jointing surface of the firstly wound strip- shaped heat insulation material part with the secondly wound strip-shaped heat insulation material are fused with each other to realize the integrated adhesion 4, 5. In addition, the generation of condensation is prevented by wholly exposing the surface of the heat insulation layer 2 or by covering the surface with an outer surface made of nonwoven fabric to absorb the water content.

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 having a straight inner pipe made of hard vinyl chloride resin, such as a heat-insulating drain pipe for air-conditioning equipment.

[0002]

2. Description of the Related Art Conventionally, as such a straight synthetic resin heat insulating pipe, a cylindrical heat insulating material made of foamed polyethylene resin is coated on the outer peripheral surface of a hard vinyl chloride resin inner pipe obtained by extrusion molding. A heat-insulating pipe is widely known in which the heat-insulating layer is formed by fitting the heat-insulating layer, and the outer peripheral surface of the heat-insulating layer is covered with an outer tube made of a soft vinyl chloride resin.

[0003]

However, in the heat-insulating pipe having such a structure, the inner pipe made of a hard vinyl chloride resin obtained by extrusion molding is inserted into a cylindrical heat-insulating material, or a hard vinyl chloride resin is used. A pair of semi-cylindrical heat insulators are put on the resin inner tube in a cylindrical shape, joined together and adhered together, and then a sheet of soft vinyl chloride resin is formed on the heat insulator into a tubular shape. Since it is manufactured by coating while molding, not only is the manufacturing complicated and time-consuming, but also when the heat-insulating material is fitted on the inner pipe made of a hard vinyl chloride resin, the cylindrical heat-insulating material is used. However, there is a problem in that a portion that expands or contracts in the length direction occurs, and it is difficult to make all the heat insulating pipes substantially uniform.

Further, the vinyl chloride resin forming the inner tube and the foamed polyethylene resin forming the heat insulating layer have poor adhesion and are difficult to be integrated by an adhesive or fusion. If the inner pipe made of the rigid vinyl chloride formed in the above-mentioned cylindrical shape is covered with a heat insulating material of the same cylindrical shape, a gap is formed between the inner pipe and the heat insulating material, and the hard vinyl chloride resin is removed from the heat insulating material of the cylindrical shape. There is a possibility that the inner pipe made of the steel may easily come off, and dew may be formed in the above-mentioned gap, thereby lowering the durability.

[0005] The problem of this escape is that if a heat insulating layer is formed by spirally winding a band-like foamed polyethylene resin heat insulating material on a cylindrical hard vinyl chloride inner tube, the tightening force due to the winding. In a heat-insulating pipe having a heat-insulating layer formed by spiral winding of such a band-shaped material, when the heat-insulating pipe is cut into a pipe of a desired length, the heat-insulating material easily jumps out from a cut end of the pipe and heat-insulates the inner and outer pipes. The layer is perturbed in the circumferential direction or the length direction to generate distortion, and the form becomes unstable and the commercial value is reduced.

Further, since the outer peripheral surface of the heat insulating layer is covered with an outer tube made of a soft vinyl chloride resin, dew condensation easily occurs on the surface of the outer tube, and the dew drops along the surface of the outer tube. There is a possibility that the device may be soiled or adversely affect the device.
The present invention has been made in view of such a problem, and is capable of suppressing the occurrence of dew condensation, is easy to manufacture, and has a stable quality and form. It is intended to be provided.

[0007]

In order to achieve the above object, the heat insulating pipe of the present invention is formed by spirally winding a heat insulating material made of a foamed resin around the outer peripheral surface of a cylindrical hard vinyl chloride resin inner tube. The above-mentioned inner pipe made of hard vinyl chloride resin is formed by helically winding a strip of hard vinyl chloride resin in a semi-molten state. It has a structure in which the outer peripheral surface of the heat insulating layer is entirely exposed.

[0008] In the heat insulating pipe configured as described above,
The invention according to claim 2 has a structure in which the exposed outer peripheral surface of the heat-insulating layer is covered with a tubular net formed by spirally winding a belt-like net,
Further, the invention according to claim 3 is characterized in that the exposed outer peripheral surface of the heat insulating layer is covered with an outer tube made of a nonwoven fabric formed by spirally winding.

Further, according to a fourth aspect of the present invention, the heat insulating material wound on the inner pipe made of the hard vinyl chloride resin is made of a foamed polyethylene resin, and the heat insulating material portion wound first and the second heat insulating material are wound next. At least the inner end or the outer end of the joint surface with the turned heat insulating material is integrally bonded.

[0010]

In the same manner as a conventional flexible heat insulating pipe, a band of semi-melted hard vinyl chloride resin, a band of heat insulating material, and a band of net or non-woven fabric, if necessary, are sequentially formed on a rotating shaft for molding. By spirally winding while polymerizing, it is possible to efficiently manufacture a homogeneous heat insulating pipe having a rigid hard vinyl chloride resin inner pipe. At this time, a thin material as a semi-molten hard vinyl chloride resin band-shaped material, which is thin and wider than the band-shaped heat insulating material, is spirally wound on the forming rotary shaft at the same pitch as the band-shaped heat insulating material. It is possible to obtain a hard vinyl chloride resin inner pipe having a certain thickness by overlapping several layers of vinyl resin strips and having a flat inner and outer peripheral surface.

Further, since the heat insulating layer is formed by spirally winding the belt-shaped heat insulating material on the hard vinyl chloride resin inner tube, the band heat insulating material is firmly tightened around the hard vinyl chloride resin inner tube. Even if the belt-shaped heat insulating material is made of a foamed polyethylene resin that is non-adhesive or difficult to adhere to the vinyl chloride resin while maintaining the fixed form, the rigid vinyl chloride resin is formed from the heat insulating layer wound in a cylindrical shape. There is no danger that the inner tube made of steel will fall out.

Further, since the heat insulating pipe exposes a heat insulating layer made of a foamed resin such as a foamed polyethylene resin to the surface, it is necessary to prevent moisture from penetrating and absorbing into the air bubbles of the heat insulating layer to form dew on the surface. In addition, by covering the outer peripheral surface (surface) of the heat insulating layer with a tubular mesh body, the heat insulating layer can be protected and prevented from being damaged. In addition, generation | occurrence | production of such dew condensation and protection of a heat insulation layer can also be prevented by coating a heat insulation layer with the outer tube which consists of nonwoven fabrics as described in Claim 3.

Further, when the heat-insulating pipe of the present invention is cut into fixed lengths, or when the heat-insulating pipe is cut to a fixed size and attached to equipment such as an air conditioner, the heat insulating material is wound spirally. Since the part of the joint surface between the previously wound heat insulating material part and the next wound heat insulating material part is integrally bonded, it is possible to prevent the heat insulating material from jumping out of the cut end of the pipe. At the same time, the heat insulating material is partially prevented from being perturbed in the length direction and the circumferential direction, and maintains a stable form.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a specific embodiment of the present invention will be described. FIG. 1 is a simplified side view in which a part of a heat insulating pipe formed in a rigid straight pipe is sectioned.
Reference numeral 1 denotes an inner tube made of hard vinyl chloride resin having a constant thickness, which is formed by spirally winding a semi-molten hard vinyl chloride resin strip on a rotary molding shaft. The surface is formed as a flat surface having the same diameter over the entire length. On the outer peripheral surface of the inner tube 1 made of the hard vinyl chloride resin, a band-shaped heat insulating material 2 ′ made of a foamed polyethylene resin and having a vertically long parallelogram in section is spirally wound at the same pitch as the band material made of the hard vinyl chloride resin. Thus, the heat insulating layer 2 is formed, and the entire surface (outer peripheral surface) of the heat insulating layer 2 is exposed.

As shown in FIG. 2, the inner pipe 1 made of hard vinyl chloride resin is wider than the upper and lower sides of a band-shaped heat insulating material 2 'made of a foamed polyethylene resin having a heat insulating layer 2 and has a film-like thickness. Alternatively, a half-molten hard vinyl chloride resin strip 1 ′ formed in a sheet-like thin-walled state in a semi-molten state may be wound on a forming rotary shaft (not shown) in an amount equal to or more than に 対 し て with respect to the strip. By spirally winding the next strip-shaped part with the overlap width, at least three layers of strip-shaped parts are formed in an inner pipe having a certain thickness which is integrated in a state of being shifted in the length direction and overlapping and integrated. Have been.

On the other hand, a strip-shaped heat insulating material having the heat insulating layer 2 formed thereon
2 ′ is formed into a parallelogram in cross section by mutually parallel front and rear surfaces 2 a and 2 b having a constant width, and inner and outer end surfaces 2 c and 2 d narrower than these front and rear surfaces 2 a and 2 b. In the state where 2b is inclined at a constant angle length direction with respect to the center line of the hose, the inclined rear surface 2b of the insulating material portion to be wound next is joined to the inclined rear surface 2b of the insulating material portion wound earlier, Furthermore, only the inner and outer ends of the front and rear joining surfaces 2a and 2b are integrally bonded 4,
Then, the bonding surfaces between the bonding portions 4 and 5 are bonded without bonding.

The heat insulating pipe thus configured maintains a rigid straight pipe shape that does not bend by the hard vinyl chloride resin inner pipe 1, and further forms the inner pipe 1. The polyvinyl chloride resin and the foamed polyethylene resin forming the heat insulating layer 3 are non-adhesive or difficult to bond, but the heat insulating material 2 ′ having the heat insulating layer 3 formed on the hard vinyl chloride resin inner tube 1 has a spiral shape. Since it is firmly pressed by the pressure tightening at the time of winding, there is no possibility that the inner tube 1 also having the cylindrical shape may come off from the heat insulating layer 3 formed in the cylindrical shape.

Further, when the heat insulating pipe is cut into a desired length, the heat insulating material 2 ′ wound spirally has a heat insulating material portion wound first and a heat insulating material portion wound next. Since the inner and outer ends of the joint surface are integrally bonded 4 and 5, the end of the strip-shaped heat insulating material 2 'does not protrude from the cut end of the pipe. The material portions are not separated in the length direction or the outer diameter direction of the hose via the bonding portions 4 and 5, and are also prevented from being deflected to each other in the circumferential direction, so that a stable form is always maintained. Things.

In the spirally wound strip-shaped heat insulating material 2 ',
To bond the inner and outer ends at the front and rear joining surfaces of the previously wound heat insulating material portion and the next wound heat insulating material portion,
The bonding may be performed by using an appropriate adhesive. However, at the time of production, the bonding end of the strip-shaped heat insulating material 2 'is melted by heating, and is fixed after cooling. In addition, this adhesive part is a band-shaped heat insulating material wound spirally.
It may be provided continuously over the entire length of 2 ′, or may be a structure that is intermittently adhered. However, in the spirally wound band-shaped heat insulating material 2 ′, first one turn in the spiral direction It is necessary to bond at least one portion of the heat insulating material portion and the heat insulating material portion wound next in a spiral direction so as to overlap the heat insulating material portion.

In the heat-insulating pipe, the surface of the foamed polyethylene resin heat-insulating layer 2 covering the hard vinyl chloride resin inner tube 1 is entirely exposed to allow water to permeate and absorb into the bubbles of the heat-insulating layer 2. Although the formation of dew condensation on the surface is prevented, as shown in FIG. 3, a tubular net covering the surface of the heat insulating layer 2 by spirally winding a belt-like net around the surface of the heat insulating layer 2 made of foamed polyethylene resin. A net 3 may be provided. Thus, the surface of the heat insulating layer 2 is
If the heat insulating pipe 2 is covered, the shape of the heat insulating layer 2 can be further stabilized, and at the time of handling or transporting the heat insulating pipe,
Alternatively, it is possible to prevent partial loss or damage during piping.

Alternatively, as shown in FIG. 4, the entire surface of the heat insulating layer 2 may be covered with an outer tube 3 'made of non-woven fabric by spirally winding a band-shaped non-woven fabric, as shown in FIG. .
In this case as well, the heat insulating layer 2 can be protected by the outer tube 3 'made of non-woven fabric and moisture can be absorbed by the non-woven fabric to prevent the occurrence of dew condensation.

Next, a brief description will be given of a method of manufacturing a heat-insulating pipe having such a structure. First, a belt-like material made of a semi-molten hard vinyl chloride resin having a constant width and thickness.
When the 1 ′ is spirally wound on a forming rotary shaft (not shown) while being extruded from a forming nozzle (not shown), as in a known manner, it is then wound on the previously wound strip 1 ′. The inner tube 1 made of a rigid vinyl chloride resin is formed by spirally winding the strip-shaped material 1 'to be wound so that the width portions of 1/2 to 2/3 overlap each other, and fusing and integrating the polymerized portions. I will do it.

Further, a cross-section made of the above-mentioned foamed polyethylene resin is not formed on the outer peripheral surface of the band-shaped material 1 'forming the inner tube 1 without forming a hollow spiral projection having a core wire therein as in a conventional flexible heat insulating pipe. A vertically long parallelogram-shaped heat insulating material 2 'is directly wound in a continuous spiral at the same spiral pitch as the above-mentioned material 1'. At this time, the inclined rear surface 2b of the heat insulating material portion wound one turn in the helical direction first and the inclined front surface 2a of the heat insulating material portion wound one turn in the helical direction are sequentially joined in a superimposed state to form the heat insulating layer 2. Front and back surfaces 2a joined to each other
The inner peripheral end of 2b is bonded and integrated. When the band-shaped heat insulating material 2 'is wound on the semi-molten state band-shaped material 1' forming the hard vinyl chloride resin inner tube 1, the bonding portion 5 raises the temperature of the band-shaped material 1 'with the foamed polyethylene resin. This is performed by keeping the melting temperature of the high-temperature strip 1 ′, and the heat of the high-temperature strip 1 ′ is used to melt the inner peripheral end of the joining surface of the strip-shaped heat insulating material portions joined to each other to bond the inner end. The part 5 is formed.

Next, if necessary, a band-shaped net or a band-shaped non-woven fabric having a fixed width is formed on the outer peripheral surface of the heat insulating layer 2. Is wound spirally at the same pitch as the above-mentioned band-shaped heat insulating material 2 ′ while polymerizing and integrally bonding the front end portions of the tubular mesh member 3 ′, thereby forming the tubular mesh body 3 or the non-woven outer tube 3 ′. At this time, when the belt-shaped net or the non-woven fabric is made of a thermoplastic synthetic resin material, and when the spirally wound edges are bonded together by heat-sealing the edges overlapped with each other, the high heat The outer end portions of the band-shaped heat insulating materials 2 'are simultaneously fused to form the bonding portion 4.

In the above manufacturing method, the inner and outer ends of the joining surfaces of the heat insulating portions joined to each other of the belt-shaped heat insulating material 2 'made of foamed polyethylene resin are welded, but at least one of the inner and outer ends of the joining surfaces is fused. What is necessary is just to wear and integrate.
As a means for fusing and integrating at least one of the inner and outer ends of the joint surface of the heat insulating material portion, an appropriate heating means is used in addition to the above-described method using heat of the inner and outer tubes. Alternatively, the heat treatment may be performed by forcibly heating the strip material forming the inner and outer tubes 1 and 3 ′, and by applying an appropriate adhesive to an appropriate portion of the joint surface of the heat insulating material portion at the time of manufacturing the heat insulating pipe. A part of the bonding surfaces may be bonded and integrated with each other. Furthermore, the band-shaped heat insulating material 2 'is not limited to the above-described vertically long parallelogram, and may have a rectangular cross-sectional shape.

[0026]

As described above, according to the heat insulating pipe of the present invention, a heat insulating material made of a foamed resin is spirally wound around the outer peripheral surface of the cylindrical inner pipe made of a hard vinyl chloride resin to form a heat insulating layer. In the straight pipe heat insulating pipe, the inner pipe made of the hard vinyl chloride resin is formed by spirally winding a belt-shaped material of the hard vinyl chloride resin in a semi-molten state, and the outer peripheral surface of the heat insulating layer is formed. Since it has a structure that is fully exposed, a belt-like material of hard vinyl chloride resin in a semi-molten state, a belt-like heat insulating material, and a belt-like net or a nonwoven fabric are sequentially polymerized on the molding rotary shaft in order. It is possible to easily and efficiently manufacture a heat-insulated pipe having a rigid inner pipe made of a rigid vinyl chloride resin by spirally winding while providing a heat-insulated pipe of stable quality.

Furthermore, since the heat insulating layer is formed by spirally winding the belt-shaped heat insulating material on the hard vinyl chloride resin inner tube, the band heat insulating material is firmly tightened around the hard vinyl chloride resin inner tube. Even when the band-shaped heat insulating material is made of a foamed polyethylene resin that is non-adhesive or difficult to adhere to the vinyl chloride resin, the rigid vinyl chloride resin There is no danger that the inner tube made of steel will fall out.

Further, since the heat insulating pipe exposes a heat insulating layer made of a foamed resin such as a foamed polyethylene resin to the surface, it is necessary to prevent moisture from penetrating and absorbing into the air bubbles of the heat insulating layer to cause dew condensation on the surface. In addition, by covering the surface of the heat insulating layer with a cylindrical mesh, the shape of the heat insulating layer 2 can be further stabilized by the cylindrical mesh, and at the same time, the shape of the heat insulating pipe can be reduced. When handling or transporting,
Alternatively, it is possible to prevent partial loss or damage during piping. Further, the heat insulating layer may be covered with an outer tube made of a nonwoven fabric in place of such a tubular net, and in this case, the moisture can be absorbed by the nonwoven fabric to prevent the occurrence of dew condensation. It can protect the heat insulating layer.

A heat insulating material made of a foamed polyethylene resin wound in a spiral shape integrally bonds a part of a joining surface between the heat insulating material portion wound first and the heat insulating material portion wound next. Although the inner pipe is formed of a vinyl chloride resin that is non-adhesive or difficult to adhere to the foamed polyethylene resin, when the heat-insulated pipe is cut to a desired length, a cut end of the pipe is formed. Can reliably prevent the strip-shaped heat insulating material from jumping out or being pulled out, and also prevent the heat insulating material from partially moving in the length direction or circumferential direction, and always maintain a stable form Piping work can be performed accurately and efficiently.

[Brief description of the drawings]

FIG. 1 is a simplified side view of a part of a heat-insulating pipe,

FIG. 2 is an enlarged cross-sectional view of a part thereof;

FIG. 3 is a partially enlarged cross-sectional view of a heat-insulating pipe in which a heat-insulating layer is covered with a tubular net;

FIG. 4 is a partially enlarged cross-sectional view of a heat insulating pipe in which a heat insulating layer is covered with an outer tube made of a nonwoven fabric.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner pipe made of hard vinyl chloride resin 1 'Strip material made of hard vinyl chloride resin 2 Insulation layer made of foamed polyethylene resin 2' Strip heat insulating material 3 Cylindrical mesh 3 'Outer pipe made of non-woven fabric 4 Outer end bonding part 5 Inner end bonding part

Claims (4)

[Claims] 1. A straight heat-insulated pipe in which a heat insulating material made of a foamed resin is spirally wound around an outer peripheral surface of a cylindrical inner pipe made of a hard vinyl chloride resin to form a heat insulating layer. The resin inner tube is formed by spirally winding a strip of hard vinyl chloride resin in a semi-molten state and exposing the entire outer peripheral surface of the heat insulating layer. pipe. 2. The heat-insulating pipe according to claim 1, wherein the exposed outer peripheral surface of the heat-insulating layer is covered with a tubular net formed by spirally winding a belt-shaped net. 3. The heat-insulating pipe according to claim 1, wherein the exposed outer peripheral surface of the heat-insulating layer is covered with an outer tube made of a nonwoven fabric that is spirally wound. 4. The heat insulating material wound on a hard vinyl chloride resin inner tube is made of a foamed polyethylene resin, and is joined to a previously wound heat insulating material portion and a next wound heat insulating material portion. The heat insulating pipe according to claim 1, wherein at least inner ends or outer ends of the surfaces are integrally bonded.