JPH10267183A - Welding joint and connection method therefor, and welding jig thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the tie for welding by using a clamp by providing a temporary welded part which covers an outer face of a pie and has a thin wall on an end part side of a pipe receive port of a joint main body which is made of thermoplastic rein and in which a heat generation body is embedded in an inner peripheral part thereof. SOLUTION: A welding joint is constituted by inserting a thermoplastic resin pipe 3 into a pipe receptive port 11 of an electrically welded joint 1 and assembling a fusion jig 2. A heating wire 12 is sprially embedded in an inner peripheral face of a joint main body 10, and an end part of the heating wire 12 is connected with a connector pin 13 embedded in the joint main body 10 and protrudes on an outer face of the joint main body 10. A thin-walled cylindrical temporary welded part 14 protrudes and is provided integrally with the joint main body 10 at an inlet of the pipe receive port 11 in an end part of the joint main body 10. The welding jig 2 is of half-split type which has a joint hold part 21 and a pipe hold part 22 which rare in contact with an outer peripheral face of the joint main body 10 and an outer peripheral face of the resin pipe 3 on an inner face of both end parts thereof and hold them and a heating part 23 which is in contact with the temporary fused part 14 of the joint and heats an outer face of the temporary welded part 14 on an inner face of a central part thereof, and a part tightened by a bolt is provided on both sides, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusion joint in which a heating element is embedded in an inner peripheral surface used for fusing a thermoplastic resin tube such as a polyethylene or polypropylene tube, a method of connecting the fusion joint, and a fusion jig thereof. More particularly, the present invention relates to fixing a pipe when a joint and the pipe are fused.

[0002]

2. Description of the Related Art When a fusion joint is used to fuse a thermoplastic resin tube with a thermoplastic resin tube, a resin tube is inserted into a tube socket of the joint, and a current is applied to a heating wire on the inner periphery of the joint. In general, fusion bonding is performed in which a resin at an inner peripheral portion and a resin at an outer peripheral portion of a tube are melted and both are integrally fused. If the tube is not fixed during the welding operation, there is a problem in that the tube is pulled out or bent during the welding operation and fused. For this reason, usually, for example, Japanese Patent Application Laid-Open No.
The resin tube inserted into the joint is fixed by using a clamp as disclosed in Japanese Patent No. 34578, and the heating wire at the inner peripheral portion of the joint is energized while the centering of the tube and the stopper of the tube are performed. A method of fusing tubes has been used.

Further, a main energizing heating element and a sub energizing heating element are buried in a central portion of a receptacle on an inner peripheral surface of a joint, and a sub-conductive heating element is buried in an inlet portion and a back portion of the receptacle, which is disclosed in JP-A-7-91584. After the connecting resin tube is inserted, when the tube is fused, the sub-heating element is first energized to heat and fuse the heating element at the inlet and the back of the receptacle, and then the main heating element is energized to join the joint. A fusion joint for fusing a tube with a tube is disclosed.

[0004]

In the case of using the above-mentioned conventional clamp, if the clamp is removed before the fused portion is not sufficiently cooled after applying heat to the heating wire and fusing, the tube is fused by the external force of the tube. There is a problem that the part is bent or the pipe comes out of the joint. For this reason, the clamp cannot be removed for a long time even after the energization is completed until the fused part is cooled down,
It takes a long time to install and remove the clamp, so a large number of clamps must be prepared in order to sequentially perform the welding work at the piping site, and the welding time is long due to the clamp. There were problems such as complicated construction work.

[0005] In the latter, a joint is formed by energizing the sub energizing heating element on the inner peripheral surface and temporarily fixing the sub energizing heating element to the tube by fusion by heating, and then energizing the main energizing heating element to fuse with the tube. In such a case, a main heating element and a sub-heating element must be provided in the receptacle of the joint, and a controller for energizing both the heating elements is required, which increases the manufacturing cost and complicates the fusion work. There was a problem. Also, in a pipe that connects a normal joint and a pipe, if bending or tensile force acts on the connected pipe, this stress tends to concentrate on the boundary between the joint and the pipe, and the pipe tends to be damaged from this part. there were. The present invention solves the above-mentioned problems, shortens the time for fusion using a clamp to a minimum time, and can perform fusion work with the pipe and the joint fixed, and after fusion fusion splicing. Another object of the present invention is to provide a fusion joint having a large pipe strength, a connection method thereof, and a fusion jig.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a thin-walled temporary fusion-bonded portion which covers the outer surface of a pipe at the end of a pipe receiving port of a thermoplastic resin joint body having a heating element embedded in an inner peripheral portion. It is a fusion joint characterized by the above. Also, a thin temporary fusion-bonded portion covering the outer surface of the pipe is provided on the end side of the pipe receiving port of the thermoplastic resin joint body in which the heating element is embedded in the inner peripheral portion, and after inserting the connection resin pipe into the pipe receiving port, The fusion joint is characterized in that the joint and the resin pipe are temporarily fused by heating from the outer surface of the fusion joint, and then the heating element on the inner peripheral part of the joint is heated and fused with the resin pipe. The connection method. In the above, the temporary fusion bonding part can be provided separately from the joint on the end of the fusion splicing joint at the tube receiving end. In addition, together with a holding portion for holding the outer surface of the resin pipe inserted into the tube socket of the fusion joint, a heating portion for heating the outer surface of the temporary fusion joint provided on the end side of the tube socket of the joint is provided. This is a fusion jig for a fusion joint.

[0007]

The present invention has the above-mentioned structure, and a thin temporary fusion-bonded portion is provided on the end of the joint at the end of the tube socket. The joint is heated and melted by a heating iron or high-frequency induction heating, and the joint and the pipe can be temporarily fused. When the temporary fused part is integral with the fitting body, it is fused to the outer surface of the pipe at the end of the joint. When the temporary fused part is separate from the fitting body, it is fused to the joint end and the outer surface of the pipe. The joint and the tube are fused together in a state where the temporary fusion bonding portion is raised on the outer peripheral surface of the tube. Since the pipe and the joint are fixed by the fusion of the temporary fusion bonding portion and serve as a conventional clamp, the heating element of the joint main body generates heat and can be fused without a clamp when performing the main fusion. In addition, since the thickness of the outer peripheral surface of the pipe at the joint end is increased by the provisionally fused portion, even if bending or tensile force is applied to the pipe after fusion splicing, the thickness of the pipe portion where the stress at the joint end tends to concentrate is increased. The thickness is increased, and the strength of the pipe after fusion splicing is improved.

Further, since the temporary fused portion is almost brought into contact with the outside air and fused, the temporary fused portion can be cooled quickly,
Even if a clamp is used during temporary fusion, it can be removed in a shorter time than before. After the temporary fusion, even if the heat generating body on the inner peripheral surface of the joint is heated without fusion,
The tube is held at the temporarily fused portion and the tube does not move.
Therefore, the main fusion work can be performed in a state where the centering and fixing are securely performed, and the main fusion can be quickly performed in a correct connection state. Further, in the welding jig of the present invention provided with a heating section for heating the temporary welding section, since the heating of the temporary welding section can be performed simultaneously with the centering and fixing of the tube, it is necessary to prepare another heating iron or the like. And the fusion work can be performed more efficiently.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a connecting portion showing a state in which a thermoplastic resin tube 3 is inserted into a tube receiving port 11 of an electric fusion joint 1 and a fusion jig 2 is assembled according to an embodiment of the present invention. A heating wire 12 is helically embedded in the inner peripheral surface of the joint body 10, and an end of the heating wire 12 is connected to a connector pin 13 embedded in the joint body. Projects to the outside. At the end of the joint main body 10, a thin-walled tubular temporary fusion bonding portion 14 is provided at the entrance of the pipe receiving port 11 so as to protrude integrally with the joint main body 10. This temporary fusion bonding portion 14 may be provided in an irregular shape that protrudes alternately at equal intervals around the circumference of the tube receiving port 11, and as shown in FIG.
Joint body 1 in contact with end face of joint body 10 and connecting resin pipe 3
Alternatively, a thin annular temporary fusion-bonding member 15 having an L-shaped cross section and formed of a member separate from the member 0 may be provided. The fusion joint 1 which generates heat by the heating wire is a conductive fiber such as carbon fiber or a laminate thereof, a processed product in the form of a mesh sheet, or a joint which generates heat by high-frequency induction heating or microwave heating. Is also good.

The inner surface of both ends of the fusion jig 2 has a joint body 10.
Has a joint holding portion 21 and a tube holding portion 22 which are in contact with and hold the outer peripheral surface of the resin tube 3 and the outer peripheral surface of the resin tube 3. 14 is a half-split type having a heating portion 23 for heating the outer surface, and has bolted portions 24 on both sides. Note that the fastening portion 24 may be hinged on one side so that it can be freely opened and closed, and one side may be a bolt fastening type. The heating part 23 has a heating wire inside, and heats and melts the outer peripheral surface of the temporary fusion part 14, so that the joint body 10 and the pipe 3 are fused together by the fusion of the temporary fusion part 14. .

In connection, the temporary receiving portion 14 or 15 is provided at the end of the joint body 10 and the pipe receiving port 11 is connected.
The end of the connection resin pipe 3 is inserted into the inside, and then the fusion jig 2 is put over the joint body 10 and the outer peripheral surface of the resin pipe 3.
Is tightened and held, and the joint 10 and the pipe 3 are centered and fixed. Next, the heating unit 23 of the fusion jig 2 is heated, and the temporary fusion unit 14 or 15 is melted on the inner surface of the heating unit 23, and the joint body 10 and the pipe 3 are temporarily integrated with the temporary fusion unit 14 or 15. We fuse. As shown in FIG. 4, this heating is performed by heating with an electric iron 25 or the like different from the welding jig to melt the temporary fused portion 14 or 15 while the tube 3 is fixed with another clamp 5. Thus, the joint 1 and the pipe 3 may be temporarily fused. Further, heating may be performed by high-frequency induction heating or microwave heating. Since this temporary fusion is performed in a state where it is exposed to the outside air instead of the inside of the thermoplastic resin joint body having poor heat conductivity as in the prior art, the cooling after the temporary fusion is fast, and thus the fusion cure is performed. The time for using the tools 2 and 5 is also short.

After the temporary fusion is completed, the electric heating wire 12 in the fusion joint body is energized from an external controller to make the electric heating wire 1
2 is heated, or the heating element in the joint main body is heated by induction heating or microwave heating, and the resin of the joint main body 10 and the resin of the pipe 3 are melted to fuse them together. At this time, even if the welding is carried out after the welding jig 2 holding the joint and the tube is removed, since both are securely fixed by the temporary welding portion 14 or 15, the tube 3 The fusion is performed in a correct state without any movement of the metal. As described above, since the time for fixing the pipe 3 is shorter than before, the entire fusion work time is shortened, and the number of the fusion jigs 2 does not need to be large. I can do it. Further, since the thickness of the temporary fusion bonding portion 14 increases on the outer peripheral surface of the pipe at the end of the joint after fusion splicing, stress of the pipe does not concentrate on the end of the joint, and as a result, the strength of the pipe increases.

[0013]

According to the present invention, the joint and the pipe can be easily fixed in a centered state, and the welding operation can be performed sequentially without preparing a large number of clamps. Be shortened. In addition, the thickness of the resin pipe at the end of the joint after fusion increases, and the strength of the pipe increases.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a state in which a resin tube is inserted into an electric fusion joint and a fusion jig is assembled according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which a resin tube is inserted into an electric fusion joint and a fusion jig is assembled according to another embodiment.

FIG. 3 is a front view of the clamp according to the embodiment of the present invention.

FIG. 4 is a plan view showing a state of temporary fusion in another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric fusion joint 2 Fusion jig 3 Resin pipe 5 Clamp 10 Joint main body 11 Pipe socket 12 Heating wire 13 Connector pin 14, 15 Temporary fusion part 21 Joint holding part 22 Resin pipe holding part 23 Heating part 24 Tightening part 25 Electric iron

Claims (4)

[Claims] 1. A fusion joint comprising a thermoplastic resin joint body having a heating element embedded in an inner peripheral portion thereof, and a thin temporary fusion-bonding portion for covering an outer surface of the tube is provided on an end side of a pipe receiving port of the thermoplastic resin joint body. 2. A thin temporary fusion-bonded portion for covering an outer surface of a pipe is provided at an end of a pipe receiving port of a thermoplastic resin joint body in which a heating element is embedded in an inner peripheral portion, and a connecting resin pipe is inserted into the pipe receiving port. Heating from the outer surface of the temporary fusion bonding portion to temporarily fuse the joint and the resin tube, and then heat the heating element at the inner peripheral portion of the joint to fuse with the resin tube. Connection method of the fitting. 3. The fusion splicing part is provided separately from the joint at the end of the tube port of the fusion splicing joint.
The connection method of the fusion joint described in the above. 4. A holding section for holding an outer surface of a resin tube inserted into a tube receiving port of a fusion joint, and a heating section for heating an outer surface of a temporary fused section provided on an end side of the pipe receiving port. A fusion jig for fusion joints.