JP2001214994A - Connecting method and connecting structure of thermoplastic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure that facilitates work and is inexpensive and stable. SOLUTION: For the connection of a thermoplastic-resin connecting pipe 1 having a spigot 4 at one end to a thermoplastic-resin connected pipe 2 having a socket at one end, a connecting method of a thermoplastic resin pipe is so designed that a heating wire 3 is wound circumferentially in serpentine fashion about the periphery of the spigot 4 of the connecting pipe 1 or about the internal surface of the socket of the connected pipe, and with the heating wire 3 fed stepwise with electric power, the spigot 4 of the connecting pipe 1 is inserted into the socket of the connected pipe 2 to allow an integral fused connection between the connecting and connected pipes 1 and 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting thermoplastic synthetic resin pipes, and more particularly, to a method of connecting thermoplastic synthetic resin pipes such as water pipes of small to large diameters using heating wires. The present invention relates to a method for connecting a thermoplastic synthetic resin tube to be fusion-spliced to a pipe. The method for connecting a thermoplastic synthetic resin pipe according to the present invention is particularly suitable for connecting a large-diameter thermoplastic synthetic resin pipe (for example, having a diameter of 200 to 2000 mm or more) at an installation site.

[0002]

2. Description of the Related Art Conventionally, this type of thermoplastic synthetic resin pipe has been connected to a conductive wire which generates heat by energizing a socket of a synthetic resin pipe (joint) having a small diameter, in particular, a diameter of 200 mm or less. The heating wire is covered with an insulating resin and wound in a coil shape along the inner peripheral surface.After one synthetic resin tube is introduced into the socket of the synthetic resin tube, the heating wire is heated to combine the two. There was a technique of fusing and joining resin tubes.

[0003] Also, large-diameter synthetic resin pipes, particularly,
In the case of 200 to 2000 mm or more, it is necessary to consider the deformation due to the weight of the pipes since both pipes to be connected are made of synthetic resin. In other words, there has been a technique of performing fusion using an inflation-compression pressing jig utilizing expansion by pressurization in order to allow a large fitting difference caused by such deformation.

[0004]

However, such a conventional technique has the following problems. (1) The number of work steps and costs are increased by using an insulating resin-coated wire. (2) When used in a large-diameter pipe for winding an insulating resin-coated wire in a coil shape, a considerable amount of heating wire is required. (3) In order to allow a fitting difference between the pipes to be connected, it is necessary to prepare an expansion / compression pressing jig having different dimensions for each diameter. Therefore, a main object of the present invention is to provide a method of connecting a thermoplastic resin pipe which can solve these problems.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a heating wire is connected to a connecting pipe made of a thermoplastic resin having at least one end with a connecting pipe made of a thermoplastic resin having a receiving port at at least one end. After winding in the meandering shape in the circumferential direction near the outer peripheral surface of the outlet of the connecting pipe or the inner peripheral surface of the receiving port, insert the connecting port of the connecting pipe into the receiving port of the connected pipe, and then Provided is a method for connecting a thermoplastic resin pipe, wherein a connecting pipe and a connected pipe are integrally fused and connected by energizing a heating wire. That is, according to the present invention, the heating wire is wound around the fitting portion, that is, near the outer peripheral surface of the inlet of the connecting pipe or near the inner peripheral surface of the receiving port of the connected pipe, in a meandering shape in the circumferential direction. Thus, workability can be improved and a low-cost and stable connection structure can be obtained with a relatively short heating wire.

In the present invention, the connecting pipe and the connecting pipe made of a thermoplastic resin are not particularly limited, but those having a diameter of 200 to 2000 mmφ or more, such as water pipes and sewer pipes, are suitable. Preferred examples of the plastic resin include polyethylene resins and polypropylene resins. A heating wire is used in the vicinity of the fitting portion between the connecting pipe and the connected pipe, that is, in the vicinity of the outer peripheral surface of the outlet or the inner peripheral surface of the receptacle. Here, the vicinity of each of the peripheral surfaces means a portion that is in contact with each of the peripheral surfaces or a portion slightly inward or outward from each of the peripheral surfaces. Specifically, a heating wire directly contacts, or Or a shallow (eg, about 1 mm deep) insert inside.

The heating wire is wound around each peripheral surface of the fitting portion between the connecting pipe and the connected pipe so as to meander in the circumferential direction. As described above, when winding the heating wire in a meandering shape, the heating wire may be wound while being formed in a meandering shape directly near the fitting portion at the installation site, but it is preferable to use a wire formed in a meandering shape in advance. preferable. In addition, the heating wire formed in a meandering shape is formed on a strip-like sheet made of the same material as the connecting pipe and the connected pipe in advance, that is, a thermoplastic resin, or sandwiched between a pair of sheets, and has an outer peripheral surface of an inlet of the connecting pipe. May be directly wound in a meandering manner with respect to the circumferential direction. Furthermore, in order to maintain the wound state, the wire may be temporarily fixed by simple welding or energization, and a heat-shrinkable sheet (polyethylene resin sheet) is placed around the heating wire and heat-shrinked. It may be held tightly on the outer peripheral surface.

The heating wire used in the present invention is not particularly limited, but a tungsten wire or a brass wire is preferable because the melting state of the thermoplastic resin as the material of the connection pipe or the connection pipe can be easily controlled.

According to another aspect of the present invention, there is provided a connecting pipe made of a thermoplastic resin having an opening at at least one end, a connecting pipe made of a thermoplastic resin having a receiving opening at at least one end, and a connecting pipe of the connecting pipe. After being wound in a meandering shape in the circumferential direction near the outer peripheral surface or the inner peripheral surface of the receiving port, an insertion port of the connecting pipe is inserted into the receiving port of the connected pipe, and then connected by being energized. Provided is a connection structure for a thermoplastic resin tube including a heating wire in which a tube and a connected tube are integrally fused and connected.

According to yet another aspect of the present invention, there is provided a connection port formed at at least one end of a thermoplastic resin connection pipe, a receptacle formed at at least one end of a thermoplastic resin connection pipe, Near the inner peripheral surface of the receptacle or near the outer peripheral surface of the receptacle, after being wound in a meandering shape in the circumferential direction, the receptacle is inserted into the receptacle of the connected pipe, and then energized, Provided is a joint structure of a thermoplastic resin pipe including a heating wire that enables integral fusion splicing of a connecting pipe and a connected pipe.

According to yet another aspect of the present invention, there is provided a thermoplastic resin tube main body having an insertion port at one end and a reception port at the other end, a portion near the inner peripheral surface of the reception port of the pipe main body, and an outer periphery of the insertion port. In the vicinity of the surface, after being wound in a meandering shape with respect to the circumferential direction thereof, the insertion port and the reception port are fitted into a pair of thermoplastic resin connected pipes, respectively, and then energized, so that a pair of Provided is a joint for a thermoplastic resin pipe comprising a heating wire enabling integral fusion splicing of the thermoplastic resin connected pipe.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings. Note that the present invention is not limited to this.

[First Embodiment] FIG. 1 is a perspective view for explaining a first embodiment of a method for connecting a thermoplastic resin pipe according to the present invention, and FIG. 2 is a heating wire used in the first embodiment. And FIG. 3 is a cross-sectional view of a connecting portion (fitting portion) of a thermoplastic resin tube in which a heating wire is in close contact with the band-shaped sheet.

First, in FIG. 1, reference numeral 1 denotes a polyethylene water supply connection pipe as a thermoplastic resin connection pipe, 2 denotes a polyethylene water supply connection pipe as a thermoplastic resin connection pipe, and 3 denotes a connection pipe 1. A heating wire (heater) 5 wound around the outer circumferential surface of the insertion hole 4 formed at one end of the opening in a meandering shape with respect to the circumferential direction, 5 is a band-shaped sheet for closely supporting the heating wire 3 from the outside in advance. is there.

The heating wire 3 is made of a brass wire having a diameter of about 1 to 3 mm and a thickness of about 1 to 2 mm on a polyethylene resin strip 5 in FIGS. The strip 4 is tightly fitted in a meandering shape in the longitudinal direction, and then, together with the belt-like sheet 5 in the tightly contacted state, the opening 4
The heating wire 3 is wound around the inside. Then, after inserting the insertion port 4 of the connection pipe into one end of the connection pipe 2 (the receptacle), the heating wire 3 is appropriately energized to complete the fusion in the vicinity of the heating wire 3. At this time, a gap 7 may be provided between the heating wire 3 on the belt-shaped sheet 5 and the connected pipe 2 as shown in FIG. 3, so that a band (not shown) or the like is appropriately used from the outside of the connected pipe 2. The connecting pipe 1 and the connected pipe 2 can be integrally fusion-spliced without gaps 7.

Of course, in this case, the outlet 4 of the connecting pipe 1
It is convenient if the thickness of the pipe 2 is large and that of the connected pipe 2 (receiving port) is small. It is preferable that the supply of electric power to the heating wire 3 be performed while gradually increasing the voltage.

[Second Embodiment] Unlike the first embodiment, the heating wire can be directly wound around the outer peripheral surface of the inlet of the connection pipe without using a strip-shaped sheet.

FIG. 4 is a view corresponding to FIG. 2 showing another example of the heating wire. In FIG. 4, the heating wire 3a is formed in a meandering shape naked, and is directly wound around an outer peripheral surface of an inlet (not shown) of the connecting pipe so as to meander in the circumferential direction. After inserting an insertion port (not shown) of the connection pipe into a receiving port (not shown) of the connection pipe, the heating wire 3a is energized, so that both connection pipes can be integrally fused and connected.
In this case as well, an operation of narrowing down from the outside of the socket of the connected pipe may be added.

[Embodiment 3] FIG. 5 is a perspective view showing another example of the receptacle of the connected pipe. In FIG. 5, when the insertion port of the connecting pipe is inserted into the receptacle 8 of the connected pipe 2a to be integrally fused and connected, in order to make the integrated fusion more reliable,
A groove 9 may be formed along the outer peripheral surface of the receptacle 8, and the groove 9 may be used to narrow the groove with a band or the like.

[Embodiment 4] FIG. 6 shows an example provided from another viewpoint of the present invention, and is an explanatory perspective view illustrating a structure for connecting thermoplastic resin pipes to each other using a joint. FIG. 7 is a view corresponding to FIG.

In FIGS. 6 and 7, a joint 11 is composed of a joint body 12 and an insertion port 1 formed at one end of the body 12.
3, a receiving port 14 formed at the other end of the main body 12, a heating wire 15 and its strip-shaped sheet 16 wound around the outer periphery of the insertion port 13, and a heating wire 21 and a strip-shaped sheet pressed against the inner peripheral face of the receiving port 14. A groove 17 is formed on the outer peripheral surface of the receptacle 14 along the circumferential surface. In addition, 18 and 19 are connected pipes.

Then, after the insertion port 13 of the joint 11 is inserted into the (receiving port) of the connected pipe 18, the heating wire 15 is energized, so that the joint 11 and the connected pipe 18 are integrally fused and connected. In this case, since there may be a gap between the heating wire 15 and the receiving port of the connected pipe 18, the band may be appropriately narrowed from the outer peripheral surface of the (receiving port) of the connected pipe 18 with a band (not shown) or the like. Preferably, an integral fusion splice is ensured.

Next, after the receiving port 14 of the joint 11 is inserted into another connected pipe 19, the heating wire 21 is energized, so that the joint 11 and the connected pipe 19 are integrally fused and connected. Here, the outer peripheral surface of the receiving port 14 of the joint 11 is narrowed by using the band 20 through the groove 17, so that the integrated fusion splicing is more reliably performed.

[Embodiment 5] FIG. 8 shows another example of a connection port of a connected pipe, and is a cross-sectional view of a main part of a fitting portion between a connection port of the connection pipe and an insertion port of the connection pipe. FIG. 4 is a graph showing an example of a relationship between a voltage applied to a heating wire and an elapsed time, and shows a tendency different depending on a heating wire material.

First, in FIG. 8, the receiving port 33 of the connected pipe 32 has a heating wire 35 meandering in the circumferential direction on the inner peripheral surface thereof. It extends outside through the through holes 37 and 38. Reference numeral 36 denotes a through hole for detecting the molten state of the thermoplastic resin near the heating wire 35. In addition, 31 is a connection pipe, and 34 is the inlet.

In this way, the electric heating wire 35 is energized through a pair of energizing terminals extending to the outside through the through holes 37 and 38 (the electric current is supplied until the molten resin is ejected from the through hole). The adjacent thermoplastic resin is melted, and the connecting pipe 31 and the connected pipe 32 are integrally fused and joined. Here, when the heating wire 35 is energized, the thermoplastic resin material can be uniformly melted without reaching the decomposition temperature by gradually increasing the voltage as shown in FIG. And the connection pipe 32 can be reliably fused and joined together. Since a gap may be formed between the heating wire 35 and the connected pipe 32, the outer peripheral surface of the receiving port 33 of the connected pipe 32 may be appropriately inserted through the groove 39 after a predetermined time from the start of energization. By tightening with a band (not shown), the occurrence of gaps is prevented even in the large-diameter connection pipe 31 and the connection pipe, thereby making the integral fusion bonding more reliable.

[Embodiment 6] Unlike Embodiment 5, a heating wire is wound around an outlet of a connecting pipe, and a current-carrying terminal of the heating wire is connected between a receiving port of a connected pipe and an outlet of a connecting pipe. It can also be taken out from between. FIG. 10 is a diagram corresponding to FIG. 8 showing the sixth embodiment. In FIG.
The outlet 44 of the connection pipe 41 has a heating wire 45 on its outer peripheral surface in a meandering shape in the circumferential direction, and a pair of energizing terminals of the heating wire are connected to the connection 44 of the connection pipe 41 and the connected pipe 42. And extends outside so as to be able to conduct electricity. Reference numeral 46 denotes a through hole for detecting the molten state of the thermoplastic resin near the heating wire 45. The other structure and the operation leading to the fusion splicing of the connecting pipe 41 and the connected pipe 42 are the same as in the fifth embodiment, and the description thereof is omitted.

[0028]

According to the present invention, the heating wire is formed in a meandering shape in the circumferential direction near the fitting portion, that is, near the outer peripheral surface of the inlet of the connecting pipe or near the inner peripheral surface of the receptacle of the connected pipe. In this way, it is possible to improve workability and obtain a low-cost and stable connection structure with a relatively short heating wire.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view for explaining a first embodiment of a method for connecting a thermoplastic resin pipe according to the present invention.

FIG. 2 is a schematic configuration explanatory view showing a heating wire and a belt-like sheet used in Embodiment 1 in a state where the heating wire is closely attached to the belt-like sheet.

FIG. 3 is a cross-sectional view of a connecting portion (fitting portion) of a thermoplastic resin tube.

FIG. 4 is a diagram corresponding to FIG. 2, showing another example (Embodiment 2) of the heating wire.

FIG. 5 is a perspective view showing another example (Embodiment 3) of the receptacle of the connected pipe.

FIG. 6 shows an example (Embodiment 4) provided from another viewpoint of the present invention, and is an explanatory diagram illustrating a configuration in which thermoplastic resin tubes are connected to each other using a joint.

7 is a view corresponding to FIG. 3, showing a cross section of a main part of FIG. 6;

FIG. 8 is a cross-sectional view of a main part of a fitting portion between a receiving port of a connected pipe and an insertion port of the connecting pipe, showing another example (Embodiment 5) of the receiving port of the connected pipe.

FIG. 9 is a graph showing a relationship between a voltage applied to a heating wire and an elapsed time.

FIG. 10 is a diagram corresponding to FIG. 8, showing another example (Embodiment 6) of a fitting portion between a socket of a connecting pipe and a receptacle of a connected pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Connecting pipe 2 Contacted pipe 3 Heating wire 4 Insertion port 5 Belt sheet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuyoshi Hasenami 2-3-1 Awaji-cho, Chuo-ku, Osaka-shi, Osaka Dainippon Plastics Co., Ltd. F-term (reference) 3H019 GA04 4F211 AA04 AA11 AD05 AD12 AD24 AG08 AH43 AK09 TA01 TC11 TD11 TH02 TH18 TN08 TN31

Claims (14)

[Claims] When connecting a connecting pipe made of thermoplastic resin having at least one end with a connecting pipe made of thermoplastic resin having at least one end, a heating wire is connected to the outer periphery of the connecting pipe. After winding in the meandering shape in the circumferential direction near the surface or near the inner peripheral surface of the receiving port, insert the connecting pipe into the receiving port of the connected pipe, and then connect by heating the heating wire. A method for connecting thermoplastic resin pipes, wherein the pipes and the pipes to be connected are integrally fused. 2. The thermoplastic resin tube according to claim 1, wherein, when the heating wire is wound near the outer peripheral surface of the connection pipe outlet, the heating wire is directly wound around the outer peripheral surface of the connection pipe insertion port. Connection method. 3. When the heating wire is wound in the meandering shape in the circumferential direction in the vicinity of the outer peripheral surface of the outlet of the connection pipe, the heating wire is previously placed on a belt-shaped sheet made of thermoplastic resin. The method according to claim 1, wherein the heating wire is closely wound in a meandering shape with respect to the longitudinal direction of the sheet, and then the heating wire is closely wound around the outer peripheral surface of the insertion port of the connecting pipe in a state of being in close contact with the belt-shaped sheet with the heating wire being inside. The method for connecting a thermoplastic resin pipe described in the above. 4. When the heating wire is wound in the meandering shape in the circumferential direction in the vicinity of the outer peripheral surface of the inlet of the connection pipe, the heating wire is previously placed between a pair of thermoplastic resin strips.
2. The connecting wire according to claim 1, wherein the heating wires are tightly wound on the outer peripheral surface of an inlet of the connecting pipe while being sandwiched between the pair of strip-shaped sheets. Connection method of thermoplastic resin tubes. 5. When the heating wire is wound around the outer peripheral surface of the outlet of the connecting pipe in a meandering shape in the circumferential direction, the heating wire is wound around the outer peripheral surface of the outlet of the connecting pipe in the circumferential direction. 2. The heating wire is tightly wound on the outer peripheral surface by winding the heating wire directly around the heating wire, and then wrapping a thermoplastic resin band-shaped sheet around the heating wire to thermally shrink.
4. The method for connecting a thermoplastic resin pipe according to the item 1. 6. An outer peripheral surface of a receiving port of a connected pipe has a groove extending in a circumferential direction of the receiving pipe, and after inserting an insertion port of the connecting pipe into the receiving port of the connected pipe, a connection is made by applying a current to a heating wire. The method for connecting a thermoplastic resin pipe according to any one of claims 1 to 5, wherein, when the pipe and the connected pipe are integrally fusion-spliced, a socket of the connected pipe is fastened by a band through the groove. . 7. The method of connecting a thermoplastic resin pipe according to claim 1, wherein the energization of the heating wire is performed by increasing the voltage stepwise. 8. The method of connecting a thermoplastic resin pipe according to claim 1, wherein the diameter of the pipe is 200 to 2000 mmφ. 9. The method of connecting a thermoplastic resin pipe according to claim 1, wherein the pipe to be connected is a pipe having a uniform inner and outer diameter. 10. The thermoplastic resin according to claim 1, wherein the receiving port of the pipe to be connected is provided with one or more through holes for taking out a terminal for supplying a heating wire to the outside. How to connect pipes. 11. The thermoplastic resin pipe according to claim 1, wherein the receiving port of the connected pipe has a through hole for detecting a molten state of the thermoplastic resin near the heating wire. Connection method. 12. A connecting pipe made of a thermoplastic resin having an inlet at least at one end, a connected pipe made of a thermoplastic resin having a receiving port at at least one end, and an outer peripheral surface of an inlet of the connecting pipe or an inner peripheral surface of the receiving port. In the vicinity, after being wound in a meandering shape with respect to the circumferential direction, the insertion port of the connection pipe is inserted into the receptacle of the connection pipe, and then the connection pipe and the connection pipe are integrally formed by being energized. A connection structure for a thermoplastic resin tube consisting of a fusion-spliced heating wire. 13. A spigot formed at at least one end of a thermoplastic resin connecting pipe, a spout formed at at least one end of a thermoplastic resin connected pipe, and a vicinity of an inner peripheral surface of the spigot or a spout of the spigot. After being wound in the meandering shape in the circumferential direction in the vicinity of the outer peripheral surface, an insertion port is inserted into a socket of the connected pipe, and then the power is supplied with electricity, so that the connecting pipe and the connected pipe are integrally fused. A joint structure of a thermoplastic resin pipe consisting of a heating wire that enables connection. 14. A thermoplastic resin pipe main body having an inlet at one end and a receptacle at the other end, and a portion in the vicinity of the inner peripheral surface of the receptacle of the tube main body and the outer peripheral surface of the insert, in the circumferential direction thereof. After being wound in a meandering manner, the inlet and the outlet are respectively fitted to the pair of thermoplastic resin connected pipes, and then the pair of thermoplastic resin connected pipes are integrally fused by being energized. A joint made of thermoplastic resin tubes consisting of a heating wire that enables connection.