JPH10238677A - Connecting structure of heat insulating double pipe and connecting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out connection between high density polyethylene pipe bodies and a fitting and their arrangement in a required from by providing the fitting, which is provided with a heating wire and fitted to the respective tip parts of the high density polyethylene pipe bodies so as to be welded to them. SOLUTION: A fitting 15, which connects high density polyethylene pipe bodies 12, 22 together, is provided with a dimension allowing it to be fitted to the high density polyethylene pipe bodies 12, 22 respectively. When electric power is supplied to a heating wire which is wound and buried in the fitting 15, the inside face of the fitting 15 and the outside faces of the high density polyethylene pipe bodies 12, 22 are fused so as to be connected together. Subsequently, heat insulating members 16, 26 cover the vicinity of the fitting 15 from the upper and lower sides. A tubular cover 17 covers circumferences of the heat insulating members 16, 26. Heat contracting tubes 18, 28 seal the connecting parts between the high density polyethylene pipe bodies 12, 22 and the tubular cover 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge addition, a water pipe bridge, a water pipe, a gas pipe, an agricultural pipe, a drain pipe, a water pipe, a digestion plug pipe, a sprinkling pipe, a district heating pipe, The present invention relates to a connection structure of a heat retaining double pipe used for a hot water pipe, a plant pipe, a building pipe, or the like, and a connection method thereof. In particular, the present invention relates to a connection structure of a heat retaining double pipe and a connection method thereof, which are highly effective for small-scale construction with small turns in a cold region.

[0002]

2. Description of the Related Art FIG. 5 is a view for explaining a state in which a conventional flexible resin cladding tube is laid. In FIG. 5, a flexible resin coating tube 53 is wound around a drum 52 mounted and fixed on a trailer 57. The flexible resin coating tube 53 is guided to the laying place using a plurality of guide rollers and the like, and has one end connected to the wire 55. Then, the wire 55 is pulled by a winch wheel 56. The flexible resin covering tube 53 has a conduit made of high-density polyethylene inside, and the periphery of the conduit is wound with a cloth tape or a stainless steel tape. After that, the flexible resin coating tube 53 is covered with a heat insulating material with urethane foam, and then covered with a steel corrugated tube. Further, the flexible resin coating tube 53 is covered with a low-density polyethylene outer tube after the anticorrosion layer.

[0003]

Since the flexible resin coating tube 53 is wound around the drum 52, there is an advantage that there is no connecting portion when laying a long section as a long one. In addition to requiring a special trailer 57, a heavy machine such as a hoist for loading the drum 52 or a winch wheel 56 is required. Therefore, the conventional long flexible resin cladding tube 53 is advantageous for long works such as many kilometers. However, construction of a relatively short section such as several meters to several tens of meters or construction in a narrow place is not always advantageous, and has a problem that the construction is expensive.

[0004] In order to solve the above problems, the present invention provides a connection structure of a heat retaining double pipe laid while connecting a relatively short heat retaining double pipe of a predetermined length, and a connection method therefor. The purpose is to do.

[0005]

[Means for Solving the Problems]

(1st invention) The connection structure of the heat retaining double pipe of the present invention comprises a high density polyethylene pipe 12 (22) and a heat insulating material 13 (2) covering the high density polyethylene pipe 12 (22).
3) and a synthetic resin sheath tube 14 (24) concentrically sheathed with respect to these, and the ends of the high-density polyethylene tube 12 (22) project at both ends. The high-density polyethylene pipe 12 (2) of the above-mentioned heat-retaining double pipe 11 (21) to be connected by the heat-retaining double-pipe connection structure.
2) Fitting to each of the distal end portions and fusion-connected with the heating wire, heat insulating materials 16 and 26 covering the joint 15 and its vicinity, and heat insulating materials 16 and 26
And heat-shrinkable tubes 18 and 28 adhered so as to cover the joint between the tubular cover 17 and the synthetic resin outer tube 14 (24).

(Second Invention) A connection structure for a heat-retaining double pipe according to the present invention comprises a high-density polyethylene pipe 12 (22) and a heat insulating material 13 for covering the high-density polyethylene pipe 12 (22). (23) and a synthetic resin sheath tube 14 (24) concentrically sheathed with respect to these, and the distal end of the high-density polyethylene tube 12 (22) projects at both ends. A heating wire which is fitted to each end of the high-density polyethylene pipe 12 (22) of the above-mentioned heated double pipe 11 (21) and fused and connected. Entering joint 15, heat insulating material 13 (23) covering the joint 15 and its vicinity, a half-tubular cover covering the heat insulating material 13 (23), the entire half-tubular cover and the half-tubular The cover and the synthetic resin outer tube 14 (2 ) It is composed of a heat-shrinkable tube which are bonded so as to cover the joint between characterized.

(Third invention) The heat retaining double pipe of the present invention is characterized by having flexibility.

(Fourth invention) The synthetic resin outer tube of the present invention is characterized in that the outer tube has a corrugated tube with concentric concave and convex or spiral shape.

(Fifth invention) The sheath tube made of synthetic resin of the present invention is characterized in that the exterior is a coaxial uneven or spiral corrugated tube, and the interior is smooth.

(Sixth invention) A joint with a heating wire according to the present invention comprises:
The power and energizing time are determined by the barcode displayed on the surface.

(Seventh invention) The heat-shrinkable tube according to the present invention is characterized in that the inner surface thereof has a pressure-sensitive adhesive layer or a heat-sensitive adhesive layer for bonding to a synthetic resin outer tube.

(Eighth invention) The tubular cover is a spiral corrugated tube.

(Ninth invention) The half-split tubular cover is characterized in that a spiral corrugated pipe is cut in half in the longitudinal direction.

(Tenth invention) A method for connecting a heat insulating double pipe according to the present invention is a method for connecting a high-density polyethylene pipe 12 (22) and a heat insulating material 13 covering the high-density polyethylene pipe 12 (22). (23) and a synthetic resin sheath tube 14 (24) concentrically sheathed with respect to these, and the distal end of the high-density polyethylene tube 12 (22) projects at both ends. Disposing the heat-insulated double pipe 11 (21), and placing the tubular cover 1 on the heat-insulated double pipe 11 (21).
7 and the step of loosely fitting the two heat-shrinkable tubes 18 and 28;
1 (21), after fitting to each end of the high-density polyethylene tube 12 (22), supplying a predetermined electric power to the heating wire for a predetermined time, and connecting the heating wire; Joint 15 and high-density polyethylene tube 12 (22)
Covering with a heat insulating material 13 (23), and moving the tubular cover 17 to cover the heat insulating material 13 (23).
(23) and a step of covering a part of the synthetic resin outer tube 14 (24), and the two heat-shrinkable tubes 18 and 28 are attached to two places of the tubular cover 17 and the synthetic resin outer tube 14 (24). And then heating and heating the joint to seal the joint.

(Eleventh invention) In the method for connecting a heat insulating double pipe according to the present invention, a heat insulating material 13 for covering the high density polyethylene pipe 12 (22) and the high density polyethylene pipe 12 (22) is provided. (23) and a synthetic resin sheath tube 14 (24) concentrically sheathed with respect to these, and the distal end of the high-density polyethylene tube 12 (22) projects at both ends. Disposing a heat-insulating double pipe 11 (21), loosely fitting a heat-shrinkable tube to the heat-insulating double pipe, and connecting the heating wire-containing joint to the heat-insulating double pipe 11 (21). High-density polyethylene tube 12 (22)
A predetermined power is supplied to the heating wire for a predetermined time after the fitting, and the step of connecting the heating wire with the heating wire and the high-density polyethylene tube 12 (22) for heat insulation is performed. The step of covering with the heat insulating material 13 (23), the heat insulating material 13 (23) and the synthetic resin outer pipe 14
A step of covering a part of (24) with a half-split tubular cover;
And 4) sealing the joint by heating after moving over the joint with 4).

(Twelfth Invention) In the method for connecting a heat insulating double pipe according to the present invention, the power supplied to the heating wire of the joint and the time thereof are determined by printing or pasting conditions determined in advance by the shape and diameter of the joint. It is characterized in that it is determined by reading the bar code being worn.

(Thirteenth invention) In the method for connecting a heat retaining double pipe according to the present invention, the electric power supplied to the heating wire of the above-mentioned joint and the time thereof are determined by measuring a discriminating resistance incorporated in the joint, and then measuring the resistance value. The power supply controller is set based on the power supply.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First invention) The applicant of the present invention pays attention to a combination of a simple connection method using a synthetic resin joint called an electrofusion joint and a seal using a heat-shrinkable tube. Even if it is a flexible insulated double tube,
We found that the construction cost can be reduced and the work can be done in a small turn. The structure of the heat retaining double pipe according to the present invention includes a high-density polyethylene pipe, a heat insulating material for covering the high-density polyethylene pipe, and a synthetic resin casing concentrically covering these. It is composed of a tube. The distal end of the high-density polyethylene pipe in the heat-retaining double pipe to be connected is formed in advance so as to protrude from the heat-insulating heat insulating material and the synthetic resin outer pipe. At the tip of the high-density polyethylene pipe to be connected, a heating-wire-containing synthetic resin joint is fitted, and the heat generated when power is supplied to the heating wire causes the joint to be connected to the high-density polyethylene. The contact surfaces with the tube body are connected to each other by melting each other. The joint and the high-density polyethylene tube in the vicinity thereof are covered with a heat insulating material such as urethane foam or styrene foam. Further, the heat insulating material is covered with a tubular cover. The joint between the tubular cover and the synthetic resin outer tube is tightly covered with, for example, a heat-shrinkable tube made of cross-linked polyethylene. The synthetic resin joint has a heating wire embedded therein and a terminal for supplying electric power.

(Second Invention) The second invention is different from the first invention in that the cover in the first invention is formed in a half-split shape and a heat-shrinkable tube is placed on the half-split cover. That is, the heat-shrinkable tube of the present invention covers the heat insulating material covering the joint, and is bonded to the two synthetic resin outer tubes via the half-cover. In the first invention and the second invention, since the seal is completely completed,
It has excellent water-tightness as well as heat retention.

(Third Invention) The heat retaining double pipe according to the present invention can utilize a combination of different lengths and flexibility, so that it can be easily laid in a curved portion or a narrow place.

(Fourth Invention) Since the outer tube made of synthetic resin of the present invention has flexibility due to the coaxial unevenness or spiral corrugated tube on the outside, it can be easily laid in a curved portion or a narrow place. . In addition to having flexibility, the uneven or spiral corrugated tube can improve the heat insulating effect by the air layer formed in the uneven portion and the spiral portion.

(Fifth invention) The outer tube made of synthetic resin of the present invention is an uneven or spiral corrugated tube having a coaxial outer portion, and the inner portion is formed smoothly. In particular, when the same synthetic resin outer tube is used for the cover, it is easy to move the smooth surface of the cover over the uneven or spiral waved portion of the synthetic resin outer tube. Further, the air existing in the space formed between the synthetic resin outer tube and the smooth surface improves the heat insulating effect.

(Sixth invention) A joint with a heating wire according to the present invention comprises:
The barcode printed or adhered to the surface is read by a barcode reader, and the result determines the power and energizing time. When a bar code is provided on the joint, a worker having special skills is not required when connecting the heat retaining double pipe.

(Seventh Invention) The heat-shrinkable tube of the present invention has a pressure-sensitive adhesive layer or a heat-sensitive adhesive layer for bonding to a synthetic resin outer tube. The heat-shrinkable tube shrinks at a seam portion, for example, when heat is applied by a burner. However, since sufficient sealing cannot be achieved only by shrinking the heat-shrinkable tube, the above-mentioned adhesive layer is provided inside, and the sealing is completely performed by this adhesive. In the heat-shrinkable tube, a separator is adhered to the inner surface of the adhesive layer, and after being arranged at a predetermined position, the separator is removed and the tube is adhered with heat.

(Eighth Invention) Since the tubular cover of the present invention is a spiral corrugated tube, a space having good flexibility and a corrugated portion is effective for heat retention.

(Ninth Invention) A half-split tubular cover according to the present invention is obtained by cutting a spiral corrugated pipe in half in the longitudinal direction, so that the connection of a heat retaining double pipe can be made simply and quickly.

(Tenth invention) First, a high-density polyethylene pipe, a heat insulating material covering the high-density polyethylene pipe, and a synthetic resin outer pipe concentrically mounted on these pipes Are arranged in a predetermined shape. Next, in the heat insulating double pipe, a part of the synthetic resin outer pipe and the heat insulating material that hinder connection are removed in advance. Before connecting the high-density polyethylene tube, the tubular cover that covers the synthetic resin outer tube is loosely fitted to one of the synthetic resin outer tubes. Further, the heat-shrinkable tube is loosely fitted on one of the synthetic resin outer tubes in advance to cover one of the tubular cover and the synthetic resin outer tube. The heat-shrinkable tube is loosely fitted in advance on the other synthetic resin outer tube in order to cover the tubular cover and the other synthetic resin outer tube. Next, the fittings with heating wires are respectively fitted to the tips of the high-density polyethylene pipes to be connected, and a predetermined power is supplied to the heating wires for a predetermined time. A part of the connected heating wire joint and the high-density polyethylene pipe body are covered from above and below, for example, by a heat insulating material formed in half. Thereafter, the tubular cover is moved onto the heat insulating material, thereby covering the heat insulating material and a part of the synthetic resin outer tube. Next, the heat-shrinkable tube is moved onto one end of the tubular cover and one end of the synthetic resin outer tube, and then heated to seal a seam between the tubular cover and the synthetic resin outer tube. Also, the joint between the tubular cover and the other end of the synthetic resin outer tube is similarly sealed.

(Eleventh invention) In the eleventh invention, after covering the tubular cover in the tenth invention in half, the heat-shrinkable tube is covered. The half tubular cover can facilitate the connection operation. That is, after covering the high-density polyethylene tube with a heat insulating material, the upper portion is further covered with a half-split tubular cover, and then the heat-shrinkable tube which has been loosely fitted to the synthetic resin outer tube in advance is a joint. To keep the part warm, it is moved to the part covered by the thermal insulation. Thereafter, the heat-shrinkable tube seals a joint between the synthetic resin outer tube and the heat-shrinkable tube by removing the separator provided inside and heating the tube from the outside.

(Twelfth Invention) The connection between the synthetic resin pipes depends on the shape, diameter and the like of the synthetic resin pipes. In view of this, the power to be supplied to the heating wire of the joint and the time in the present invention are determined by reading a bar code printed or pasted under conditions previously determined by the material, thickness and diameter of the joint. That is, since the power supply for supplying power to the joint is provided with the barcode reading device, anyone can easily set the power and the supply time. The bar code can read the manufacturer name, type of joint (straight pipe, branch pipe, curved pipe), bore size, lot number, melting time, cooling time, and the like.

(Thirteenth invention) According to the present invention, the method of setting the power to be supplied to the heating wire of the joint and the time thereof is as follows: After measuring the identification resistance incorporated in the joint, the controller of the power supply is set based on the measured value. . After measuring the resistance value, the power supply controller can automatically determine the power and the power supply time based on the measured resistance value. Therefore, anyone can easily determine the power and the supply time only by measuring the resistance value. Further, the resistance value can be made to be able to identify a correction coefficient depending on temperature, a resistance value of a heating wire, a voltage value, and the like.

[0031]

[Embodiment] FIG. 1 is a conceptual perspective view for explaining a connection between heat retaining double tubes according to an embodiment of the present invention. FIG.
(A) is an example of the present invention, and is a conceptual cross-sectional view for explaining a state in which a heat retaining double pipe is connected, and (B) is a perspective view of the heat retaining double pipe. FIG. 3 is a conceptual diagram for explaining a method of connecting synthetic resin tubes using joints in one embodiment of the present invention. FIG. 4 is a conceptual diagram for explaining a heat-shrinkable tube used in an example of the present invention. In FIG. 1, the heat retaining double tubes 11, 21 are arranged at the center,
For example, synthetic resin pipes 12 and 22 serving as water pipes,
It is composed of synthetic resin foams 13 and 23 such as urethane, phenol, silicon, olefin, or styrene filled around the outer circumference, and synthetic resin outer tubes 14 and 24 covering the foams 13 and 23. I have.

The synthetic resin pipes 12 and 22 are made of, for example, high-density polyethylene and are suitable for water pipes, gas pipes, agricultural water pipes, drain pipes, and the like. The synthetic resin outer tubes 14 and 24 are made of, for example, low-density polyethylene and have helical waves or have unevenness coaxial with the axis. In addition, the inner surfaces of the synthetic resin outer tubes 14 and 24 having spiral waves or having irregularities are sometimes smooth, and in this case, an air layer is formed between the inner smooth surface and the outer tubes. Therefore, there is an advantage that the heat retaining effect is further increased and the foaming agents 13 and 23 are easily formed in the intermediate portion. Further, the synthetic resin outer tubes 14 and 24 have a color that does not allow ultraviolet rays to enter, in order to prevent deterioration of the foam materials 13 and 23 that are housed inside.

The foam members 13 and 23 are made of, for example, hard urethane foam, and are made of synthetic resin tubes 12 and 22.
When the stock solution such as urethane is discharged from the tip of the firing nozzle, air is introduced between the and the synthetic resin outer tubes 14 and 24 to cause foaming. Foaming material 13, 23 inserted between synthetic resin pipes 12, 22 and synthetic resin outer pipes 14, 24
It is good to change the density depending on the location. For example,
At the place where the heat retaining double tubes 11 and 21 are bent, the density of one and the other is changed in advance so that the bending is cheap. In addition, the heat retaining double tubes 11 and 21 can increase the density at a location where stress is concentrated, or at a side or a portion where heat insulation is required. In the factory, several kinds of such heat retaining double tubes 11 and 21 having a predetermined length are prepared in advance. Also,
The heat retaining double tubes 11 and 21 are provided with foam materials 13 and 23 and a synthetic resin outer tube 14 so as to be easily connected at the distal end.
A part of 24 is previously formed short.

The joint 15 connecting the synthetic resin pipes 12, 22 is made of the same or substantially the same material as the synthetic resin pipes 12, 22 and can be fitted to the synthetic resin pipes 12, 22, respectively. It has a size. The joint 15 is embedded with a heating wire (not shown) wound, for example, in a spiral shape. By supplying power to the heating wire, the inner surface of the joint 15 and the synthetic resin tube 1 are connected.
The outer surfaces 2 and 22 are fused and connected. The joint 15 is provided with terminals (not shown) at both ends of the heating wire, and power cables 36 and 36 ′ from a power supply (not shown) are connected to the terminals via sockets 35 and 35 ′. You. As the above-mentioned joint, what is known as a known electrofusion joint is used.

The heat insulating materials 16 and 26 are the same as the foam materials 13 and 23. For example, a material formed in a half-split shape is prepared and covered so as to hold the vicinity of the joint 15 from above and below. It is. The tubular cover 17 is provided with, for example, a spiral wave, and is made of a synthetic resin tube 1.
It is slightly larger than the diameter of 2, 22 and is the same material as the synthetic resin outer tubes 14, 24. Further, the shape of the tubular cover 17 includes a coaxial unevenness and a shape having a smooth surface through a space inside the unevenness or the spiral wave. FIG.
On the left side, the tubular cover 17 shown in (a) does not have the same pitch as the spiral wave of the synthetic resin outer tube 14, but is forcibly pushed from right to left. ing. The tubular cover 17 is fitted while being rotated substantially in line with the spiral wave of the synthetic resin outer tubes 14 and 24. Furthermore, the synthetic resin outer tubes 14 and 24
An air layer is appropriately formed between the pipe and the tubular cover 17 to serve as a heat insulating layer. The heat-shrinkable tubes 18 and 28 are shrunk by heat, and seal the joint between the synthetic resin tubes 12 and 22 and the tubular cover 17.

Next, a description will be given of a method of connecting the above-mentioned heat retaining double tubes 11, 21. The heat-retaining double pipes 11 and 21 are loaded into a truck with a predetermined length suitable for the installation location and transported to the installation location. At the laying place, the synthetic resin pipe 12 and the synthetic resin pipe 22 are abutted so as to have a correct arrangement. And the synthetic resin outer tube 14,
The tip portion of 24 is formed in advance so as to project a predetermined length. In this state, for example, as shown in FIG.
It is loosely fitted in (24). The heat-shrinkable tube 18
Is loosely fitted to the tubular cover 17. The other synthetic resin outer tube 24 is connected to the heat-shrinkable tube 2 in the same manner as described above.
8 is loosely fitted.

In the method of connecting the synthetic resin tubes 12, 22, first, the connecting portion is cleaned. The cleaned connection portion fits the joint 15 and the fixing base 3 shown in FIG.
1 are mounted on the lower clamps 32, 32 '
It is arranged to be in the correct position. The connecting portions of the synthetic resin tubes 12 and 22 are connected to upper clamps 33 and 33 '.
And are fastened and fixed by the fastening machines 34, 34 'so as not to move.

The terminals (not shown) provided on the joint 15 are fitted with sockets 35 and 35 ',
6, 36 'connect to a power source (not shown). For example, a bar code is printed or affixed to the joint 15, and even if the material, size, and the like of the joint 15 are unknown, the melting condition can be determined by a bar code reader provided in the power supply device. Therefore, the power supply automatically sets the power of the condition read by the barcode reader and the supply time thereof. The power supply has a program for interpreting data read by the barcode reader and setting a predetermined power and a supply time.

Further, another power source can be set by measuring the power to be supplied to the heating wire of the joint and the time for the electric power by measuring a discriminating resistance previously incorporated in the joint.
That is, the above conditions can be properly set by the operator by measuring the resistance and then setting it in the controller of the power supply. The measured resistance can also allow the power controller to be automatically set. When electric power is supplied to the heating wire, the outer surfaces of the synthetic resin pipes 12 and 22 and the inner surface of the joint 15 melt. After the end of the predetermined time, the insulated double tubes 11, 21
Performs natural cooling until the connection is hardened.

After the synthetic resin tubes 12, 22 have been connected, each clamp is removed. Thereafter, the periphery of the joint 15 is surrounded so that the heat insulators 16 and 26 in half are embraced from above and below. In addition, the circumference of the heat insulating materials 16 and 26 is covered by rotating the tubular cover 17 previously loosely fitted to the synthetic resin outer tube 14 while rotating it spirally and moving it in parallel. Next, the heat-shrinkable tube 18 loosely fitted to the synthetic resin outer tube 14 is moved from left to right in FIG. 1 to cover the seam between the tubular cover 17 and the synthetic resin outer tube 14. Similarly, the synthetic resin outer tube 24
The heat-shrinkable tube 28 that has been loosely fitted to the cover is moved from right to left in FIG. 1 to cover the joint between the tubular cover 17 and the synthetic resin outer tube 24. Heat-shrinkable tubes 18, 28
For example, when heated by a burner, it shrinks and makes the tubular cover 17 and the synthetic resin outer tubes 14 and 24 adhere to each other by the adhesive formed on the inner surface. As described above, the insulated double tubes 11 and 21 are
The connection state shown in FIG.
The watertightness is further improved by the contraction forces of 8, 28.

The heat-shrinkable tubes 18 and 28 are, for example, as shown in FIG.
Butyl rubber-based pressure-sensitive adhesive 1
82 are formed. In addition, the heat-shrinkable tube 18,
A separator 183 is provided inside the adhesive 182 formed on the substrate 28. The separator 183 is made of, for example, a transparent polyethylene film, and a release agent is applied to the adhesive 182 side so that the separator 183 can be easily peeled off. After the heat-shrinkable tubes 18 and 28 are placed in place, the separator 183 can be bonded only after being pulled out. Further, the adhesive 182 may be a heat-sensitive adhesive. The heat-shrinkable tubes 18 and 28 are used by cutting the cylinder shown in FIG. 4 into a predetermined width.

Although not shown, the second embodiment of the present invention uses a synthetic resin outer tube or a tubular cover in which a tube one size larger than the synthetic resin outer appearance is halved. That is, the half-split tubular cover is disposed so as to cover the heat insulating material after the connection between the synthetic resin pipe and the joint and the installation of the heat insulating material are completed. Thereafter, as in the first embodiment, the heat-shrinkable tube is moved to a predetermined position, and after the separator is pulled out, the heat-shrinkable tube is heated by a burner or the like. As a result, the heat-shrinkable tube and the synthetic resin outer tubes 14 and 24 are bonded.

The present embodiment has been described in detail above.
It is not limited to the above embodiment. Various design changes can be made without departing from the present invention described in the appended claims. For example, the synthetic resin tube, the synthetic resin outer tube, the joint, the cover, the foam material, the heat insulating material, and the heat-shrinkable tube are merely examples in the examples, and a known or well-known material is used. can do. In addition, the outer shape of the heat retaining double tube is arbitrarily shaped according to the purpose such as length, presence or absence of irregularities and spirals, straight or curved, other than concentric circles, other than circular, and further, such as deformation such as bifurcation or trifurcation. it can. Also,
Similarly, a known or well-known power supply or barcode reader can be used.

[0044]

According to the present invention, by using a relatively short heat-retaining double pipe, a simple welding machine, and joints of various shapes, the high-density polyethylene pipe and the joint can be connected. Since it can be laid in a desired shape, it is easy to adapt to the shape to be laid. According to the present invention, the use of the heat-shrinkable tube and the adhesive formed on the inner surface of the heat-shrinkable tube have made it possible to completely seal the connection portion. According to the present invention, by adopting a heat-resistant member for the heat-shrinkable tube, even if it is heated from the outside, it merely shrinks, and the adhesion with the synthetic resin outer tube can be improved. Was.

According to the present invention, since the synthetic resin outer tube is provided with spiral waves or provided with coaxial irregularities on the outside, an air layer is formed in this portion to improve the heat retaining property and also to improve the flexibility. It was possible to have. According to the present invention, compared to a steel pipe or a synthetic resin pipe wrapped with a stainless steel tape or cloth tape, it is easy to bend and light, and has no rusting parts. According to the present invention, since the synthetic resin layer, the air layer, the heat insulating layer, and the synthetic resin layer are formed as a multilayer tube, there is no need to provide a heater for preventing freezing.

[Brief description of the drawings]

FIG. 1 is a conceptual perspective view illustrating a connection between heat retaining double tubes according to an embodiment of the present invention.

FIG. 2A is a conceptual cross-sectional view for explaining a state in which a heat-retaining double pipe is connected in one embodiment of the present invention, and FIG. 2B is a perspective view of the heat-retaining double pipe.

FIG. 3 is a conceptual view for explaining a method of connecting synthetic resin pipes using a joint in one embodiment of the present invention.

FIG. 4 is a conceptual diagram illustrating a heat-shrinkable tube used in an example of the present invention.

FIG. 5 is a view for explaining a state in which a flexible resin cladding tube that has been conventionally constructed is laid.

[Explanation of symbols]

11, 21 ・ ・ ・ Insulated double tube 12,22 ・ ・ ・ Synthetic resin tube (High-density polyethylene tube) 13,23 ・ ・ ・ Foam material 14, 24 ・ ・ ・ Synthetic resin outer tube 15 ・..Couplings 16, 26: heat insulating material (heat insulating material for heat insulation) 17: tubular cover 18, 28: heat-shrinkable tube 181: outer layer 182: adhesive 183: separator 31 ... Fixing table 32, 32 '... Lower clamp 33, 33' ... Upper clamp 34, 34 '... Fastener 35, 35' ... Socket 36, 36 '... Cable

Claims (13)

[Claims] 1. A high-density polyethylene pipe body, a heat insulating material for covering the high-density polyethylene pipe body, and a synthetic resin outer pipe concentrically outer of these pipes. In the connection structure of a heat insulating double pipe in which the ends of the high-density polyethylene pipe protrude at both ends, the heat-insulating double pipe is fitted to each end of the high-density polyethylene pipe of the heat insulating double pipe, A joint containing a heating wire to be melt-connected, a heat insulating material for covering the joint and the vicinity thereof, a tubular cover for covering the heat insulating material, and a joint between the tubular cover and the synthetic resin outer pipe. And a heat-shrinkable tube that is adhered as described above. 2. A high-density polyethylene pipe body, a heat insulating material for covering the high-density polyethylene pipe body, and a synthetic resin outer pipe concentrically mounted on these pipes. In the connection structure of a heat insulating double pipe in which the ends of the high-density polyethylene pipe protrude at both ends, the heat-insulating double pipe is fitted to each end of the high-density polyethylene pipe of the heat insulating double pipe, , A joint containing a heating wire to be melt-connected, a heat insulating material covering the joint and the vicinity thereof, a half cover covering the heat insulating material, the whole tubular tube cover and the half tubular cover, and the above synthesis And a heat-shrinkable tube adhered so as to cover a joint with the resin outer tube. 3. The connection structure for a heat retaining double pipe according to claim 1, wherein the heat retaining double pipe has flexibility. 4. The connection structure for a heat insulating double pipe according to claim 1, wherein the synthetic resin outer pipe is a corrugated pipe having a coaxial concave and convex or a spiral shape. 5. The connection as claimed in claim 4, wherein the outer tube made of synthetic resin is a corrugated tube with concentric corrugations or spirals, and the inside is smooth. Construction. 6. The connection structure for a heat retaining double pipe according to claim 1, wherein the electric wire and the energizing time of the joint containing the heating wire are determined by a bar code displayed on the surface thereof. . 7. The heat-shrinkable tube has a pressure-sensitive adhesive layer or a heat-sensitive adhesive layer on an inner surface thereof for bonding to a synthetic resin outer tube. Heated double tube connection structure. 8. The connection structure according to claim 1, wherein the tubular cover is a spiral corrugated tube. 9. The connection structure according to claim 2, wherein the half-split tubular cover is formed by cutting a spiral corrugated pipe in half in a length direction. 10. A high-density polyethylene pipe, a heat insulating material for covering the high-density polyethylene pipe, and a synthetic resin outer pipe concentrically external to the pipe. A step of arranging a heat retaining double tube in which the ends of the high-density polyethylene pipe project at both ends; a step of loosely fitting a tubular cover and two heat-shrinkable tubes to the heat retaining double tube; After fitting the hot wire-filled joint to each end of the high-density polyethylene pipe body of the heat retaining double pipe to be connected, supplying a predetermined power to the heating wire for a predetermined time, and connecting the heating wire, Covering the heating wire-filled joint and the high-density polyethylene tube with a heat insulating material; and moving the tubular cover to cover a part of the heat insulating material and the synthetic resin outer tube. Two heat-shrinkable tubes After moving over the seam of two positions of the serial tubular cover and a synthetic resin jacket tube, by heating, a method of connecting insulation double pipe, characterized the step of sealing the seam, in that it consists of. 11. A high-density polyethylene tube, a heat insulating material for covering the high-density polyethylene tube, and a synthetic resin outer tube concentrically outer of these tubes. A step of arranging a heat-retaining double pipe in which the ends of a high-density polyethylene pipe project at both ends, a step of loosely fitting a heat-shrinkable tube to the above-mentioned heat-retaining double pipe, and connecting a joint containing a heating wire Supplying a predetermined electric power to the heating wire for a predetermined time after fitting the fitting into each end of the high-density polyethylene pipe of the heat-retaining double pipe, and connecting the heating wire-containing joint And covering the high-density polyethylene tube with a heat insulating material; and covering a part of the heat insulating material and the synthetic resin outer tube with a half-tubular cover. The entire tubular cover and After moving over the joint between half tubular jacket and a synthetic resin cladding tube, by heating, a method of connecting insulation double pipe, characterized the step of sealing the seam, in that it consists of. 12. The electric power supplied to the heating wire of the joint and its time are determined by reading a bar code printed or affixed under conditions predetermined by the shape and diameter of the joint in advance. The method for connecting a heat retaining double pipe according to claim 10 or 11. 13. The power supplied to the heating wire of the joint and the time thereof are determined by measuring a discriminating resistance incorporated in the joint, and then setting a controller of a power supply based on the measured resistance value. The method for connecting a heat retaining double pipe according to claim 10 or 11.