JP2015068450A - Resin pipe and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin pipe capable of being manufactured at low cost and excellent in heat exchange performance, and a manufacturing method thereof.SOLUTION: A high thermal conductive fiber 3 having higher thermal conductivity than a resin pipe body 2 is buried in the wall thickness direction of the pipe body 2. The high thermal conductive fiber 3 is buried in a radial direction to be the wall thickness direction of the pipe body 2. Four high thermal conductive fibers 3 are buried with predetermined intervals in the circumferential direction of the pipe body 2, and are arrayed with predetermined intervals along the longitudinal direction of the pipe body 2. The high thermal conductive fiber 3 is a high strength polyethylene fiber, and the high strength polyethylene fiber is sewn with a sewing machine needle into the pipe body 2 in a molten state of being molded by an extruder, and is subjected to cooling solidification.

Description

  The present invention relates to a resin pipe excellent in thermal conductivity used for heat exchange and a method for producing the same.

  In recent years, there is an increasing need for effective use of unused heat resources such as geothermal heat, sewage heat, and factory waste water. For example, a method is known that suppresses power consumption by using geothermal heat, which has less heat fluctuation than the outside air temperature, as a heat source for a heat pump. In this apparatus, a ground heat exchanger such as a U-shaped pipe buried deep in the ground is connected to a heat pump, and heat is supplied and discharged by circulating water, antifreeze, or the like inside the pipe.

  As such an underground heat exchanger, generally, a resin pipe having excellent corrosion resistance as compared with a metal pipe is used. Compared to metal pipes, resin pipes have the advantage of being transportable as a roll and requiring fewer joint locations. As such a resin tube, high-density polyethylene having a relatively high thermal conductivity among general-purpose resins and excellent in weather resistance, creep resistance, moldability, and the like is often used. However, since high-density polyethylene is inferior in heat conductivity to metal pipes, it requires a large surface area for heat exchange. For example, in the case of a borehole type with underground heat, a buried pipe extended to about 100 m underground The disadvantage is that it is necessary to increase the number, which causes high costs.

  As a means for solving such a drawback, it is known that a filler having excellent thermal conductivity is blended with a base resin as a resin tube. For example, in the heat exchange pipe described in Patent Document 1, the thermal conductivity is increased by adding carbon nanotubes (hereinafter sometimes referred to as CNT) to the base resin, and the CNT has an anchor effect. It has the feature of being difficult to flow out into the body.

  Further, in the heat exchanger described in Patent Document 2, the U-shaped pipe includes a heat conductive filler as a material having higher heat conductivity than that of the resin, and the heat conductive filler is bonded with a low melting point metal. Thus, a heat conduction path (heat conduction path) is formed.

JP 2010-190471 A JP 2008-256329 A

    However, the heat exchange pipe described in Patent Document 1 has a problem that CNTs are very expensive compared to general-purpose fillers. Further, in the heat exchanger described in Patent Document 2, there is a concern about deterioration of the matrix resin itself as a base material due to the presence of a low melting point metal in the resin, and a liquid such as warm water is circulated inside the tube. In such a case, there is a problem that a low melting point metal may flow out.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a resin pipe that is low in manufacturing cost and excellent in heat exchange performance and a manufacturing method thereof.

In the resin pipe according to the present invention, high heat conductive fibers having higher thermal conductivity than the pipe body are arranged in the thickness direction of the resin pipe body, and the high heat conductive fibers are arbitrarily arranged in at least one of the circumferential direction and the longitudinal direction of the pipe body. It is characterized by being arranged at intervals of.
ADVANTAGE OF THE INVENTION According to this invention, heat exchange performance can be improved by the high heat conductive fiber arranged at arbitrary intervals in at least one of the circumferential direction and the longitudinal direction of the resin tube, and the manufacturing cost of the resin tube can be reduced.

Moreover, the high thermal conductive fiber may protrude from at least one of the inner surface and the outer surface of the tube body.
Since the high heat conductive fiber protrudes from at least one of the inner surface and the outer surface of the resin tube, the heat transfer performance to the fluid or the like of the exposed portion of the high heat conductive fiber is further improved.

Moreover, you may coat | cover the outer surface of a tubular body with the coating layer which consists of resin containing the highly heat conductive filler.
By covering with a resin coating layer filled with a high thermal conductive filler as the coating layer, the gap generated when embedding the high thermal conductive fiber in the tube can be filled with the coating layer, and the high thermal conductive filler Since the resin is filled, heat transfer performance with the outside world can be improved.

Further, the high thermal conductive fiber may be a high strength polyethylene fiber or a metal fiber.
Since the high thermal conductive fiber is a high-strength polyethylene fiber or a metal fiber, it can be embedded in the pipe body by stitching or piercing, and the cost is low compared with a carbon nanotube or the like. Further, the thermal conductivity can be increased as compared with the configuration in which the filler is included in the resin tube.

The method of manufacturing a resin pipe according to the present invention includes a step of forming a resin pipe body by extrusion molding, and inserting a high thermal conductive fiber in the thickness direction of the pipe body to at least one of the circumferential direction and the longitudinal direction of the pipe body. And a step of cooling and solidifying the tube body.
According to the present invention, high thermal conductivity fibers can be inserted in the thickness direction of a tubular body in a molten state in which a tubular body made of resin is formed by extrusion molding. Alternatively, a resin tube can be formed by extrusion molding and cooled and solidified, and then melted again to insert a high thermal conductive fiber, and then cooled and solidified again.

Further, after the step of cooling and solidifying the tubular body, a step of coating the outer surface of the tubular body with a resin coating layer filled with a high thermal conductive filler and a step of cooling and solidifying the coating layer may be provided.
By covering with the resin filled with the high thermal conductive filler, the gap generated when the high thermal conductive fiber is embedded in the tube can be filled with the coating layer.

Alternatively, after the step of inserting the high heat conductive fiber into the tube body, a step of closely contacting the tube body and the high heat conductive fiber to eliminate the gap may be provided.
The gap can be filled by applying stress in the molten state of the base resin of the tube, specifically means for crimping from the inner and outer surfaces of the tube, and means for compressing the tube by pressing in the longitudinal direction Alternatively, a means for compressing in a resin pipe sizing process can be employed. Or you may employ | adopt the means to closely_contact | adhere with the high heat conductive fiber by melting the base material resin of a tubular body.

Further, in the step of inserting the high thermal conductive fiber in the thickness direction of the tubular body, the high thermal conductive fiber may be projected from at least one of the inner surface and the outer surface of the tubular body.
Since the high heat conductive fiber protrudes from at least one of the inner surface and the outer surface of the tubular body, the heat transfer performance to the fluid or the like of the exposed portion of the high heat conductive fiber is further improved.

Moreover, you may make it cut | disconnect the high heat conductive fiber which protruded from the pipe body after the process of inserting a high heat conductive fiber in a pipe body.
When a fluid is transported inside the resin pipe, or when the resin pipe and a joint, another resin pipe, or the like are joined, it is possible to prevent the high thermal conductive fiber from becoming an obstacle.

  According to the resin pipe and the method of manufacturing the same according to the present invention, high heat conduction fibers are included in the thickness direction of the pipe body, and the high heat conduction fibers are arranged at least in the circumferential direction or the longitudinal direction of the pipe body. An excellent resin tube can be obtained at low cost. In addition, since the high thermal conductive fiber is embedded in the thickness direction of the tube body, there is no possibility of causing outflow or misalignment even if a fluid such as warm water is circulated inside the resin tube.

It is a principal part perspective view of the resin tube for heat exchange by 1st embodiment of this invention. (A) in the resin pipe shown in FIG. 1 is an AA line sectional view, (b) is a BB line sectional view. It is principal part explanatory drawing which shows the manufacturing apparatus of the resin pipe | tube by 1st embodiment. (A) is a figure which shows the pipe body in the manufacturing apparatus of FIG. 3, and the sewing needle of an exclusive sewing machine, (b) is a figure which shows the sewing process of the high heat conductive fiber to a pipe body, (c) is from a pipe body. It is a figure which shows the cutting process of the high heat conductive fiber which protruded. The resin tube for heat exchange by 2nd embodiment of this invention is shown, (a) is sectional drawing orthogonal to the longitudinal direction of a tubular body, (b) is a longitudinal cross-sectional view along a longitudinal direction. It is principal part explanatory drawing which shows the manufacturing apparatus of the resin pipe by 2nd embodiment. It is principal part explanatory drawing which shows the manufacturing apparatus of the resin pipe by 3rd embodiment. It is principal part explanatory drawing which shows the manufacturing apparatus of the resin pipe | tube by 4th embodiment.

Hereinafter, a resin tube for heat exchange according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the accompanying drawings.
1 to 4 show a resin tube excellent in heat exchanging performance according to the first embodiment of the present invention and a manufacturing method thereof.
A resin tube 1 according to the first embodiment shown in FIGS. 1 and 2 is a pipe having a tubular tube body 2 used as a heat exchanger, for example, and is made of resin and has a predetermined thickness. The inner surface of the tubular tube 2 is referred to as an inner surface, and the outer surface is referred to as an outer surface. As shown in FIGS. 2 (a) and 2 (b), the tubular body 2 is a cross-sectional view orthogonal to the longitudinal direction. As shown in FIGS. 3 is arranged in the radial direction, that is, in the thickness direction. In addition, as shown in FIGS. 1 and 2B, a plurality of the high thermal conductive fibers 3 are arranged in a straight line at a predetermined interval along the longitudinal direction of the tube body 2.

Here, the resin used as the base material of the resin tube 1 is not particularly limited. For example, polyolefin resins such as high-density polyethylene, crosslinked polyethylene, polypropylene, and polybutene, polyphenylene sulfide, polyethylene terephthalate, and vinyl chloride are preferably used. It is done. Among them, high-density polyethylene and crosslinked polyethylene that are excellent in cost, moldability, and thermal conductivity are preferable. Further, for the purpose of improving the thermal conductivity of the base resin of the tube body 2, a composite of fibers and fine particles of a material such as metal, glass and carbon may be used.
When, for example, high-strength polyethylene fibers 3a are used as the high heat conductive fibers 3, it is preferable from the viewpoint of adhesiveness to use high-density polyethylene having the same molecular structure as the base resin.

The high thermal conductive fiber 3 is formed in a linear body having higher thermal conductivity than the resin of the tube body 2. When the high-strength polyethylene fiber 3a is used as the high heat conductive fiber 3, the ultrahigh molecular weight polyethylene is oriented by stretching, and micro level defects in the polymer that can become a heat scattering point, for example, molecular end, molecular chain entanglement As long as there is little folding of the molecular chain, it is not particularly limited. From the viewpoint of thermal conductivity, polyethylene nanofibers consisting of several polymer chains are most preferable. However, since continuous productivity and handling are poor, practically, high-strength polyethylene fibers 3a such as Dyneema (Toyobo Co., Ltd.) (Registered trademark) can be preferably used.
The volume content of the high-strength polyethylene fiber 3a in the base material is not particularly limited, but it is 0.1% or more and 50% or less to improve the thermal conductivity, complicate the sewing process, and the strength of the resin tube 1 Considering maintenance, it is considered a practical range.

  Further, when metal fibers are used as the high thermal conductive fibers 3, examples of the metal fibers include iron, stainless steel, copper, silver, aluminum, and the like. Although not particularly limited, stainless steel fibers excellent in cost and corrosion resistance are particularly preferable. And aluminum fibers are preferred.

Note that a metal or carbon layer may be provided on the surface layer of the tubular body 2 in order to further enhance the heat transfer performance with the outside world. As a method for forming the tube body 2 in multiple layers, in addition to a conventionally known coextrusion method, a physical vapor deposition method such as plating, sputtering, or arc ion plating, heat or plasma is used for the formed tube body 2. Chemical vapor deposition can also be used. In particular, it is preferable to form a diamond-like carbon thin film in order to increase thermal conductivity.
For the same purpose, the inner and outer layers of the tube 2 may have a fin shape.

  As a manufacturing method of the resin pipe 1 according to the first embodiment, the manufacturing apparatus 5 shown in FIGS. 3 and 4 is used, and a tubular resin molded body is discharged as the pipe body 2 by extrusion molding, and then continuously. The process includes a step of sewing a large number of high thermal conductive fibers 3 so as to penetrate in the thickness direction of the tube body 2. As the method, for example, when the high heat conductive fiber 3 is a high strength polyethylene fiber 3a, the vertical movement of the sewing needle 7 in which the high heat conductive fiber 3 is passed through the needle hole like a sewing machine is used. For example, a dedicated sewing machine 8 as a sewing device for sewing in a thick thickness, a method of drilling the tube body 2 with a drill, a laser, or the like, and passing a fiber through the hole with a needle or suction.

On the other hand, when the high heat conductive fiber 3 is a metal fiber, its strength and rigidity can be effectively used. Therefore, the method of piercing and penetrating the high heat conductive fiber 3 as it is into the molten resin is the easiest. When the fiber outer diameter is thin and the strength is inferior, as in the high-strength polyethylene fiber 3a described above, the sewing machine needle 7 can be sewn into the tube body 2 like the dedicated sewing machine 8, or the tube body 2 can be perforated. A method of inserting the high thermal conductive fiber 3 into the hole thus formed can be used.
The method of sewing the high thermal conductive fiber 3 is the tube 2 in which the resin made of the molten tube 2 to be discharged, or after cooling and solidification, or the resin 2 in the molten state again after cooling and solidification. Any of the above may be performed.

Next, although the manufacturing method of the resin pipe | tube 1 by the 1st embodiment of this invention is demonstrated with FIG.3 and FIG.4, this invention is not limited to the following manufacturing method.
The manufacturing apparatus 5 for the resin pipe 1 according to the first embodiment will be specifically described with reference to FIGS. This manufacturing apparatus 5 includes an extrusion molding machine 6 for extruding a resin tube 2 and a sewing needle 7 that feeds out a roll-like high thermal conductive fiber 3 and passes through a needle hole to project the high thermal conductive fiber 3 into a tube. A dedicated sewing machine 8 that is sewn into the body 2 is provided. Further, a sizing die 9 having a continuously taper for downsizing the outer diameter of the resin tube 1 and a cooling water tank 10 for cooling the resin tube 1 whose outer diameter is adjusted are disposed in front of the dedicated sewing machine 8. And.

A method of manufacturing the resin pipe 1 according to the first embodiment using the manufacturing apparatus 5 will be described with reference to FIGS.
First, for example, high-density polyethylene is used as a resin as a base material, and the tube body 2 having an outer diameter of 32.5 mm and a wall thickness of 3.5 mm is formed and discharged by the extruder 6. And the high heat conductive fiber 3 which consists of the continuous high strength polyethylene fiber 3a whose outer diameter is about 0.5 mm, for example with the exclusive sewing machine 8 was embedded in the longitudinal direction of the pipe body 2 at predetermined intervals.
As shown in FIG. 2 (a), the embedding intervals of the high thermal conductive fibers 3 are embedded in the radial direction at intervals of 90 degrees on the ring-shaped thick surface in a cross section perpendicular to the longitudinal direction of the tube body 2, and As shown in FIG. 2B, the tube body 2 was also embedded in the longitudinal direction at intervals of about 10 mm, for example. In other words, the high thermal conductive fibers 3 are embedded along four straight lines in which two planes perpendicular to each other through the center line of the cross section perpendicular to the longitudinal direction of the tube body 2 intersect the inner surface and the outer surface of the tube body 2, that is, in four rows. It is.

  The process of embedding the high thermal conductive fiber 3 by the dedicated sewing machine 8 will be described with reference to FIG. 4. As shown in FIG. 4A, the tube 2 formed by the extruder 6 is heated to about 130 ° C. by IR heating without contact. As shown in FIG. 4 (b), the sewing machine needle 7 is pulled out while the pipe body 2 is being fed as shown in FIG. The highly heat-conductive fiber 3 is sewed into the tube body 2 along the longitudinal direction at intervals of, for example, 10 mm through the tube body 2 from the outer surface to the inner surface in the radial direction. Then, as shown in FIG. 4C, the plurality of high thermal conductive fibers 3 protruding from the inner surface and the outer surface along the longitudinal direction of the tube body 2 are cut by the cutter 12. This operation is repeated at, for example, four locations in the circumferential direction of the tube body 2.

Thereafter, the obtained resin tube 1 is subjected to diameter reduction processing with a sizing die 9 having a taper such that the outer diameter becomes 32 mm. Thereafter, the resin pipe 1 having high thermal conductivity can be obtained by cooling by passing the cooling water tank 10 connected to the sizing die 9.
Thus, as a polyethylene pipe in which four rows of high-strength polyethylene fibers 3a are arranged in the circumferential direction as the high thermal conductive fibers 3 in the thickness direction of the resin pipe body 2 and arranged at predetermined intervals along the longitudinal direction of the pipe body 2 The resin tube 1 was manufactured.

  Further, in this manufacturing apparatus 5, a gap is generated when the high thermal conductive fiber 3 is sewn into the tube body 2 with the sewing needle 7, and the base material resin of the resin tube 1 is melted so that this gap is eliminated. A step of filling the gap between the sewing needles 7 by applying stress is provided. Specifically, for example, a method of pressing from both the inner and outer surfaces of the resin tube 1, a method of pressing the end surface of the tube body 2 partially in the longitudinal direction, and compressing the tube body 2 as a product in advance. A method in which the outer diameter is slightly larger than the outer diameter of 1 and is compressed to a required outer diameter in the sizing process using the sizing die 9 is exemplified.

  The atmosphere temperature in the sewing process is preferably equal to or higher than the temperature at which the base resin of the tube body 2 is melted. In particular, when the high-strength polyethylene fiber 3a is used as the high thermal conductive fiber 3, it is about 150 ° C. near the melting point. It is desirable that it is about the following. If the atmospheric temperature is not higher than the melting temperature of the base resin, the base resin does not flow, so that the gap cannot be closed. On the other hand, the high heat conductive fibers 3 arranged in the tube body 2 are higher than the melting point of the high heat conductive fibers 3. Since the orientation state of the material collapses and uniform high thermal conductivity is not maintained, it is necessary to handle the sewing process in the temperature range of the above-described range. Note that this is not the case with metal fibers.

  When metal fibers are used instead of the high-strength polyethylene fibers 3a as the high thermal conductive fibers 3, in order to improve the adhesion between the metal fibers and the base resin of the tube body 2, for example, an adhesive layer is provided on the surface of the tube body 2. It may be interposed. Alternatively, the adhesion between the metal fiber and the base resin may be improved by partially melting the base resin by induction heating to the metal fiber.

  Further, in the sewing process, the high thermal conductive fiber 3 protruding from the inner and outer surfaces of the tube body 2 may be cut by a cutter 12 with an appropriate length as shown in FIG. The cutting location of the high thermal conductive fiber 3 is not particularly limited, but for the purpose of improving the heat transfer performance, it is preferable to project the tube body 2 from the inner and outer surfaces by a length of about 5 mm, for example. However, when priority is given to the fluid transport function inside the tube body 2 or when it becomes an obstacle when the resin tube 1 and the joint are joined, the portion where the high thermal conductive fiber 3 protrudes from the inner and outer surfaces of the tube body 2 You may cut | disconnect with the cutter 12 etc. so that there may not be.

  As described above, according to the resin tube 1 and the manufacturing method thereof according to the first embodiment, the high heat conduction fiber 3 is embedded in the thickness direction of the tube body 2 by sewing or the like, and the high heat conduction fiber 3 is embedded in the tube body 2. Therefore, the resin pipe 1 having a uniform high thermal conductivity and excellent heat exchange performance can be obtained at low cost. In addition, since the high thermal conductive fiber 3 is embedded through the thickness of the pipe body 2 in the radial direction, even when a liquid such as warm water is circulated inside the resin pipe 1, it flows out or causes a misalignment. There is no fear.

  The present invention is not limited to the resin pipe 1 according to the first embodiment described above, and appropriate modifications and substitutions are possible without departing from the scope of the present invention. included. Although other embodiments and modifications of the present invention will be described below, the same or similar parts or members as those of the above-described embodiment will be described using the same reference numerals.

Next, the resin tube 15 and the manufacturing method thereof according to the second embodiment of the present invention will be described with reference to FIGS.
The resin pipe 15 according to the second embodiment includes a coating layer 16 on the outer peripheral surface thereof in addition to the configuration of the resin pipe 1 in which the high thermal conductive fibers 3 are embedded at predetermined intervals in the longitudinal direction of the pipe body 2 according to the first embodiment. Is a double pipe coated with The coating layer 16 is, for example, a thin layer made of a resin filled with a high thermal conductive filler.

Here, the resin of the coating layer 16 is not particularly limited, but it is preferably the same as the base material resin of the tube body 2 from the viewpoint of adhesion, and high density polyethylene for the same reason as the base material resin. It is preferable to do this.
In addition, the high thermal conductive filler to be filled is not particularly limited, and fine particles such as carbon black, carbon fiber, carbon nanofiber, magnesium oxide, boron nitride, alumina, zirconia, silicon carbide, silica, silver, copper, aluminum and the like Is mentioned. However, from the viewpoint of filling the gap formed by the sewing needle 7 in the tube body 2, a macro fibrous material should be avoided. For example, carbon black is a suitable example. The high thermal conductive filler is preferably a material having higher thermal conductivity than the base material.

Next, a manufacturing apparatus 18 for the resin pipe 15 according to the second embodiment is disclosed in FIG. 6, and this manufacturing apparatus 18 is similar to the manufacturing apparatus 5 according to the first embodiment, and includes an extruder 6 and a dedicated sewing machine 8. And a roll-like high thermal conductive fiber 3 and a cooling water tank 10. A coating mold 20 for forming the coating layer 16 on the outer peripheral surface of the resin pipe 1 is installed on the front side of the cooling water tank 10 in the tube conveyance direction, and a cooling water tank 22 for the resin pipe 15 is installed on the front side thereof. ing.
Further, an extrusion molding machine 21 for supplying a molten resin for forming the coating layer 16 is installed in the vicinity of the coating mold 20. The extrusion molding machine 21 is supplied with a pellet raw material in which 3 parts by weight of carbon black is mixed in advance with the same high-density polyethylene as the base resin of the tube body 2, melts and extrudes into the coating die 20, and A coating layer 16 is formed on the outer periphery.

The manufacturing apparatus 18 according to the second embodiment has the above-described configuration. Next, a manufacturing method of the double-pipe resin pipe 15 using the manufacturing apparatus 18 will be described.
According to the manufacturing method of the resin pipe 15, the high thermal conductive fiber 3 is sewn into the pipe body 2 formed by the extruder 6 as in the first embodiment with the dedicated sewing machine 8, and cooled and solidified in the cooling water tank 10, for example, outside A resin tube 1 having a diameter of 30 mm and a wall thickness of 2.5 mm was obtained and mounted in the coating mold 20. On the other hand, in the extrusion molding machine 21 for coating, a pellet raw material in which 3 parts by weight of carbon black is blended in advance with the same high-density polyethylene as the base resin is melted, and this coating resin is filled in the coating mold 20 to form a resin. The double pipe of the resin pipe 15 in which the outer peripheral surface of the pipe 1 was coated to form the coating layer 16 was obtained. Then, the double pipe was cooled and solidified in the cooling water tank 22 to produce a highly heat conductive resin pipe 15 having an outer diameter of 32 mm and a wall thickness of 3.5 mm, for example.

  In the resin pipe 15 of the double pipe according to the second embodiment, the gap generated when the high thermal conductivity fiber 3 is sewn into the pipe body 2 with the sewing needle 7 in the resin pipe 1 can be filled with the covering layer 16.

Next, in the resin pipe 24 according to the third embodiment, instead of the high-strength polyethylene fiber 3a as the high heat conductive fiber 3 embedded in the pipe body 2 in the resin pipe 1 in the first embodiment, the aluminum wire 3b is arranged in the thickness direction. They are aligned and arranged.
The aluminum wire 3b as the high thermal conductive fiber 3 was embedded in the wall thickness of the tubular body 2 by piercing in the radial direction from the outer surface to the inner surface of the tubular body 2 instead of sewing with the sewing needle 7. The embedding interval of the aluminum wire 3b was the same as that of the high heat conductive fiber 3 of the high strength polyethylene fiber 3a according to the first embodiment. The aluminum wire 3b has a relatively high strength and can be pierced into the molten tube 2.

Next, FIG. 7 shows the manufacturing apparatus 25 which manufactures the resin pipe | tube 24 by 3rd embodiment.
In the manufacturing apparatus 25 shown in FIG. 7, a metal wire embedding means 26 is provided on the front side of the extrusion molding machine 6 to pierce the aluminum wire 3b as the high thermal conductive fiber 3 drawn from the roll from the outer surface of the tubular body 2 to the inner surface. Further, an induction heating device 27 for heating the aluminum wire 3b and a cooling water tank 10 are installed in front of it.

Next, the manufacturing method of the resin tube 24 according to the third embodiment using the manufacturing apparatus 25 will be described. For example, high-density polyethylene is used as a base material resin, and the extruder 6 has an outer diameter of φ30 mm and a wall thickness of 3. A 5 mm tube 2 is formed and discharged. Thereafter, an aluminum wire 3b having an outer diameter of about φ1 mm, for example, is pierced into the tube body 2 as the high thermal conductive fiber 3 by the metal wire embedding means 26 and cut into a wall thickness or slightly longer.
Then, the aluminum wire 3b is embedded in the longitudinal direction of the tube body 2 at a predetermined interval, for example, 10 mm intervals, and a plurality of wires, for example, four wires are embedded at 90 degree intervals in the circumferential direction of the tube body 2. As a result, the aluminum wire 3b was embedded and arranged along four straight lines where two planes perpendicular to each other through the central axis of the tube 2 intersected with the inner surface and the outer surface of the tube 2.

In the metal wire embedding means 26 of the manufacturing apparatus 25, the tube body 2 is heated to about 130 ° C. without contact by IR heating, and the aluminum wire 3 b is pierced into the outer surface of the tube body 2, along the inner and outer surfaces of the tube body 2. The step of cutting and polishing the protruding aluminum wire 3b is repeated.
Thereafter, the aluminum wire 3b is continuously heated to about 150 ° C. by the induction heating device 27 to be fused to the base resin of the tube 2 to fill the gap, and further solidified by the cooling water tank 10 A highly heat conductive resin tube 24 was obtained.

  Next, the resin tube 30 according to the fourth embodiment has the same structure as the resin tube 15 of the double tube according to the second embodiment described above, and instead of the high-strength polyethylene fiber 3a as the high thermal conductive fiber 3, a metal is used. It is a double pipe pierced and embedded in the thickness direction using an aluminum wire 3b which is a fiber. The arrangement configuration of the aluminum wires 3b embedded in the tube body 2 is the same as the arrangement configuration of the high-strength polyethylene fibers 3a.

Next, the manufacturing apparatus 33 for the resin pipe 30 according to the fourth embodiment will be described with reference to FIG.
This manufacturing apparatus 33 has the same configuration as the manufacturing apparatus 18 according to the second embodiment, and includes an extrusion molding machine 6, a metal embedding means 26, an aluminum wire 3b that is a roll-like high thermal conductive fiber 3, and a cooling water tank. 10. A coating mold 20 for forming the coating layer 16 on the outer peripheral surface of the resin tube 24 is installed on the front side of the cooling water tank 10 in the tube transport direction, and a cooling water tank 22 is installed in front of the coating mold 16. Further, an extrusion molding machine 21 that supplies a resin for forming the coating layer 16 is installed in the vicinity of the coating mold 20. The extrusion molding machine 21 is supplied with a pellet raw material in which 3 parts by weight of carbon black is blended in advance with the same high-density polyethylene as the base resin of the tube body 2 and melts and extrudes it into the coating mold 20 to form the coating layer 16. To do.

  Next, the manufacturing method of the resin pipe 30 according to the fourth embodiment using the manufacturing apparatus 33 will be described. As shown in FIG. 8, the extruder 6 and the metal wire embedding means 26 are the same as in the third embodiment. Thus, the aluminum wire 3b was pierced and aligned in the thickness direction of the molded tube body 2 and solidified by the cooling water tank 10 to obtain, for example, a resin tube 24 having an outer diameter of 30 mm and a wall thickness of 2.5 mm. Thereafter, a pellet raw material in which 3 parts by weight of carbon black is blended in advance with the same high density polyethylene as the base resin is melted by the coating extruder 21 and supplied to the coating mold 20 to coat the outer peripheral surface of the resin tube 24. Coating with layer 16 gave a double tube. Then, this double pipe was solidified in the cooling water tank 22 to produce a highly heat conductive resin pipe 30 having an outer diameter of 32 mm and a thickness of 3.5 mm, for example.

  As described above, the resin pipes 1, 15, 24, and 30 manufactured by the manufacturing method using the respective manufacturing apparatuses 5, 18, 25, and 33 are formed by the high thermal conductive fibers 3 arranged in the thickness cross-sectional direction of each pipe body 2. In order to configure a heat conduction path (heat conduction path) in the radial direction and the longitudinal direction of the resin pipes 1, 15, 24, 30, respectively, a normal high-density polyethylene pipe (for example, an outer diameter of 32 mm and a wall thickness of 3.5 mm) And excellent thermal conductivity corresponding to the heat conduction contribution. Further, when the high heat conductive fiber 3 protrudes from the inner and outer surfaces of the tube body 2 and there is a fluid on the inner and outer surfaces of the tube body 2, further improvement in heat transfer is expected.

  In each of the above-described embodiments, the high thermal conductivity fiber 3 is sewn from the outer surface to the inner surface of the resin tube body 2 with the sewing needle 7 or is embedded by piercing the resin of the tube body 2 into the resin. However, the means for embedding the high thermal conductive fiber 3 in the tube body 2 is not limited to these means, and an appropriate means can be adopted. For example, the highly heat-conductive fiber 3 may be inserted by making a hole in the cooled and solidified tube body 2 with a drill or the like.

Further, the resin pipes 1, 15, 24, and 30 having excellent heat exchange performance according to each of the above-described embodiments have the high heat conductive fibers 3 inserted in the thickness direction of the pipe body 2 and the circumferential direction and the longitudinal direction of the pipe body 2. However, it may be arranged at least in any one of them. For example, when the high thermal conductive fibers 3 are arranged in the circumferential direction of the tube body 2, the tubes 2 may be sequentially provided at positions shifted in the circumferential direction in the longitudinal direction of the tube body 2. In addition, when the high heat conductive fibers 3 are arranged in the longitudinal direction of the tube body 2, the high heat conductive fibers 3 in each row are arranged at unequal intervals in the longitudinal direction so that the circumferential direction is the longitudinal direction of the tube body 2. The structure which is not arranged in the same orthogonal cross section may be sufficient.
Alternatively, the high thermal conductive fibers 3 may be arranged on the inner and outer surfaces of the tube body 2 at random in the circumferential direction and the longitudinal direction or at equal intervals. Even in these cases, the heat exchange performance can be improved as compared with the conventional resin pipe.

  Since the resin pipe according to the present invention has a configuration in which high thermal conductive fibers are embedded and arranged at arbitrary intervals in the radial direction and the longitudinal direction of the pipe body, the thermal conductivity is high while being low in cost, and underground heat and sewage It can be used as a resin tube excellent in heat exchange performance that can efficiently exchange heat with a heat source such as heat.

1, 15, 23, 30 Resin pipe 2 Tube 3 High thermal conductive fiber 3a High strength polyethylene fiber 3b Aluminum wire 5, 18, 25, 33 Manufacturing device 6, 21 Extruder 7 Sewing needle 8 Dedicated sewing machine 9 Sizing die 10, 22 Cooling water tank 16 Coating layer 26 Metal embedding means 27 Induction heating device

Claims (9)

  High heat conductive fibers having higher thermal conductivity than the tube are arranged in the thickness direction of the resin tube, and the high heat conductive fibers are arranged at arbitrary intervals in at least one of the circumferential direction and the longitudinal direction of the tube. A resin tube characterized by being made.   The resin pipe according to claim 1, wherein the high thermal conductive fiber protrudes from at least one of an inner surface and an outer surface of the tubular body.   The resin pipe according to claim 1 or 2, wherein the outer surface of the pipe body is covered with a coating layer made of a resin containing a highly thermally conductive filler.   The resin pipe according to any one of claims 1 to 3, wherein the high thermal conductive fiber is a high-strength polyethylene fiber or a metal fiber. Forming a resin tube by extrusion molding; and
Inserting a high thermal conductive fiber in the thickness direction of the tubular body and arranging in at least one of a circumferential direction and a longitudinal direction of the tubular body;
Cooling and solidifying the tube; and
A method for producing a resin tube, comprising: After the step of cooling and solidifying the tubular body, a step of coating the outer surface of the tubular body with a resin coating layer filled with a high thermal conductive filler;
The method for producing a resin pipe according to claim 5, further comprising a step of cooling and solidifying the coating layer.   The method for producing a resin tube according to claim 5 or 6, further comprising a step of causing the tube body and the high heat conductive fiber to closely contact each other to eliminate a gap after the step of inserting the high heat conductive fiber into the tube body. In the step of inserting high thermal conductivity fibers in the thickness direction of the tube body,
The method for manufacturing a resin pipe according to any one of claims 5 to 7, wherein the high thermal conductive fiber is projected from at least one of an inner surface and an outer surface of the tubular body.   The method for producing a resin pipe according to any one of claims 5 to 8, wherein the high thermal conductive fiber protruding from the tubular body is cut after the step of inserting the high thermal conductive fiber into the tubular body.

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