JP2001050469A - Pipe joining method - Google Patents

Abstract

(57) [Summary] [Problem] Without completely stopping the water flowing down inside,
Provided is a pipe joining method capable of fusion joining pipe ends of a thermoplastic resin pipe using an electric fusion joint. SOLUTION: The pipe ends of thermoplastic resin pipes 11 and 12 to be joined are connected to the packing 132 via a short pipe 13 in which packings 132 are mounted in concave grooves provided in both end faces along a circumferential direction. After heating the surfaces of the pipe ends to be fused together, the heating wire 142 was embedded in the thermoplastic resin across the abutting portion of the pipe ends. The electric fusion joint 14 is covered with the electric fusion joint 14.
Is applied to the heating wire 142 to melt-join between the inner peripheral surface and the outer peripheral surfaces of the two pipe ends.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of temporarily stopping water between pipe ends of a thermoplastic resin pipe to be joined which cannot completely stop water, and connecting the pipe ends to each other by using an electric fusion joint. The present invention relates to a pipe joining method for fusion joining.

[0002]

2. Description of the Related Art Conventionally, when repairing the ends of a resin tube, for example, as described in Japanese Patent Application Laid-Open No. 3-251436, fused portions are provided at both ends between cut portions of the resin tube. A pipe repair method is known in which a repair pipe is inserted and a fused portion of the repair pipe is fused to a resin pipe.

[0003] In the case where such tube ends of a resin tube are fusion-bonded to each other using an electric fusion joint, if moisture or oil is attached to the surface to be fusion-bonded, the fusion interface may be formed. Since there is a problem that bubbles and the like are generated and the fusion strength is reduced, in the standard construction, the surface to be subjected to the electrofusion bonding is cleaned (without acetone).

[0004] However, when water is not completely stopped by the gate valve when the existing pipe is extended or the like, water on the surface to be subjected to the electrofusion joining cannot be completely removed. It was necessary to carry out the mechanical joining. In the case of this mechanical joining method, there are problems that the construction is troublesome and the joining strength is low as compared with the fusion joining method.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems and solves the problem of electrofusing the ends of thermoplastic resin tubes without completely stopping the water flowing down the inside. An object of the present invention is to provide a pipe joining method that can perform fusion joining using a joint.

[0006]

According to the first aspect of the present invention, the thermoplastic resin pipes to be joined are provided with the pipe ends along the circumferential direction on both end faces. Abutting in a state where water is temporarily stopped by the packing via a short pipe having a packing attached to the concave groove, and after cleaning the surface to be fused at the end of the pipe, the butt is joined to the abutting portion between the pipe ends. Straddling,
An electric fusion joint in which a heating wire is embedded in a thermoplastic resin is covered, and the electric heating wire of the electric fusion joint is energized, so that the inner peripheral surface and the outer peripheral surfaces of the two pipe end portions are fusion-bonded. It is a pipe joining method.

The invention described in claim 2 of the present application (the present invention 2)
Abutting the pipe ends of the thermoplastic resin pipes to be joined in a state where a packing is attached to a concave groove provided on at least one end face of the pipe end and water is temporarily stopped by the packing; After cleaning the surface of the pipe end to be fused, the electrofusion joint in which the heating wire is embedded in the thermoplastic resin is put over the abutting portion of the pipe ends, and the electric fusion joint is covered. Is a pipe joining method for melting and joining an inner peripheral surface and an outer peripheral surface of both pipe ends by applying a current to the heating wire.

The invention described in claim 3 of the present application (the present invention 3)
The temporary end of the thermoplastic resin pipes to be joined is fitted with temporary waterproof plugs with packings installed in concave grooves provided on the outer peripheral surfaces of both ends of the cylindrical body, and these packings are used to temporarily After the ends are joined in a water-stopped state and the surface to be fused at the end of the tube is cleaned, the electric heating wire is embedded in the thermoplastic resin over the joint of the end of the tube. This is a pipe joining method in which a joint is put on and a heating wire of the electric fusion joint is energized to melt-join between an inner peripheral surface and an outer peripheral surface of both pipe ends.

In the present invention, the thermoplastic resin forming the thermoplastic resin tube and the electrofusion joint is not particularly limited. For example, polyethylene such as high-density polyethylene and medium-density polyethylene, and polyolefin-based resins such as polypropylene are used. No.

[0010] In the present invention, the material of the packing is not particularly limited. For example, those having excellent heat resistance such as ethylene-propylene-diene-terpolymer (EPMD) and styrene-butadiene rubber (SBR) are used. Is preferred. As the shape of the packing, for example, an O-shaped one having no cut surface irregularities, a plate-like packing, a self-sealing type capable of improving water stoppage, and the like are used.

[0011] In the present invention, as the electric fusion joint,
Generally, those on the market are used as appropriate. In the present invention, for cleaning (water removal) the surface of the thermoplastic resin tube to be fused at the end thereof, for example, a method of wiping using an etalle or the like is used.

In the first aspect of the present invention, as the short pipe, any pipe that can be generally used as a pipe is used as long as it is not easily deformed. In the present invention 3, as the material of the temporary water stop plug, a material that can maintain strength even if it is thin and does not corrode is preferable.

[0013]

According to the pipe joining method of the present invention 1, the pipe ends of the thermoplastic resin pipes to be joined are connected to each other through short pipes provided with packing in concave grooves provided along the circumferential direction on both end faces. Butting is performed in a state where water is temporarily stopped by packing, and after cleaning the surface of the pipe ends to be fused, a heating wire is buried in the thermoplastic resin over the abutting portion of the pipe ends. The inner pipe and the outer pipe at the ends of the pipes are melt-bonded by energizing the heating wire of the pipe, and the new pipe is joined to the existing pipe. In such a case, even if it is not necessary to completely stop the flowing water flowing down inside, it is possible to temporarily stop the water with the packing of the short pipe interposed between the pipe ends of the thermoplastic resin pipe to be joined. Therefore, it is possible to clean (remove moisture) the surface to be fused at the end of the pipe.
The fusion bonding can be performed by the electric fusion joint without generating bubbles or the like at the fusion interface or reducing the fusion strength.

According to a second aspect of the present invention, there is provided a pipe joining method, wherein a packing is attached to a pipe end of a thermoplastic resin pipe to be joined in a concave groove provided on at least one end face of the pipe end. The ends of the pipes to be fused are cleaned after the surfaces are temporarily stopped, and then the electric heating wire is embedded in the thermoplastic resin over the abutting portions of the pipe ends. By covering the splice joint and energizing the heating wire of the electric fusion splice, the inner peripheral surface and the outer peripheral surface of both pipe ends are melt-bonded, so that a new pipe is joined to an existing pipe. In this case, even if the flowing water flowing down the inside is not completely stopped, the pipe ends are temporarily stopped by a packing interposed between the pipe ends of the thermoplastic resin pipes to be joined. Can clean (removal of water) the surface to be fused, so that bubbles etc. are generated at the fusion interface. Without or, or reduce the fusion strength can be melt bonded by an electric welding joint.

According to a third aspect of the present invention, there is provided a method of joining pipes, wherein the pipe ends of the thermoplastic resin pipes to be joined are temporarily sealed with packing provided in concave grooves provided on the outer peripheral surfaces of both ends of the tubular body. After the plugs are fitted and the packings are temporarily stopped by the packing, butting is performed, the surface of the pipe ends to be fused is cleaned, and then the thermoplastic resin is spread over the butting portions of the pipe ends. Is covered with an electric fusion joint in which a heating wire is buried, and by applying a current to the heating wire of the electric fusion joint, the inner peripheral surface thereof and the outer peripheral surface of both pipe ends are melt-bonded. Even if it is not necessary to completely stop the flowing water flowing down, it is necessary to stop the melting of the thermoplastic resin pipes in a state where the pipe ends are temporarily stopped by packing with waterproof plugs installed inside the pipe ends. Since the surface to be bonded can be cleaned (removal of water), bubbles and the like may be generated at the fusion interface, Without or reduce the wear strength, it can be melt bonded by an electric welding joint.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are explanatory views for sequentially explaining steps of an example of the pipe joining method of the present invention.
In FIGS. 1A and 1B, reference numerals 11 and 12 denote thermoplastic resin tubes to be joined made of polyethylene or the like. 13
Is a short pipe made of polyethylene or the like interposed between the pipe ends of the thermoplastic resin pipes 11 and 12, and has concave grooves 131 on both end faces along the circumferential direction. Groove 1
Packings 132, 132 are mounted on 31, 31, respectively. The outer diameter and thickness of the short pipe 13 are the thermoplastic resin pipe 1
The tube ends are substantially the same as the tube ends 1 and 12.

Reference numeral 14 denotes an electro-fusion joint 14 in which receiving ports 141 and 141 are provided at both ends and heating wires 142 and 142 are embedded in the inner surfaces of the receiving ports 141 and 141, respectively. And terminals 143 and 143 leading to heating wires 142 and 142 so as to protrude from the surface.
143 are provided.

In the pipe joining method of this embodiment, first, as shown in FIG. 1A, an electric fusion joint 14 is mounted on one thermoplastic resin pipe 11 and the thermoplastic resin The tube ends of the tube 11 and the other thermoplastic resin tube 12 are connected to each other with a short tube 13 interposed therebetween.
Match in the condition that water is temporarily stopped in 1. In this state, the surfaces to be fused at both ends of the pipes are sufficiently cleaned (removed of water).

Next, as shown in FIG. 1B, the electric fusion joint 1 is mounted on one of the thermoplastic resin tubes 11.
4 is moved and covered so as to straddle the butted portions of the tube ends of the thermoplastic resin tubes 11 and 12. Further, terminals 14 are connected to the heating wires 142 of the electric fusion joint 14.
3, 143, the inner peripheral surface and the outer peripheral surfaces of both ends of the thermoplastic resin tubes 11, 12 are melt-bonded.

FIGS. 2A and 2B are explanatory views for sequentially explaining the steps of another example of the pipe joining method of the present invention. FIG.
In (a) and (b), 21 is a new tube, which is one thermoplastic resin tube made of polyethylene or the like. A concave groove 221 is provided on the end face of the thermoplastic resin tube 22 along the circumferential direction. A packing 212 is mounted in the concave groove 211. Reference numeral 22 denotes an existing pipe for joining a new pipe, which is the other thermoplastic resin pipe made of polyethylene or the like. 2
Reference numeral 4 denotes an electrofusion joint similar to that described with reference to FIGS. 1 (a) and 1 (b). Only the figure numbers corresponding to FIGS. 1A and 1B are given, and the detailed description thereof is omitted.

In the pipe joining method of this embodiment, first, as shown in FIG. 2A, an electro-fusion joint 24 is mounted on one thermoplastic resin pipe 21 and the thermoplastic resin The pipe ends of the pipe 21 and the other thermoplastic resin pipe 22 are connected to each other by a concave groove 211 provided on the end face of the thermoplastic resin pipe 21.
Butted in a state where the water is temporarily stopped by the packing 212 attached to the hopper. In this state, the surfaces to be fused at both ends of the pipes are sufficiently cleaned (removed of water).

Next, as shown in FIG. 2 (b), the electrofusion joint 24 is moved so as to straddle the abutting portion between the ends of the thermoplastic resin tubes 21 and 22 and cover it. Furthermore,
By energizing the heating wires 242 and 242 of the electric fusion joint 24 from the terminals 243 and 243, the inner peripheral surface and the outer peripheral surfaces of both ends of the thermoplastic resin tubes 21 and 22 are fusion-bonded.

FIGS. 3A and 3B are explanatory views for sequentially explaining the steps of still another example of the pipe joining method of the present invention. In FIGS. 3A and 3B, reference numerals 31 and 32 denote thermoplastic resin tubes to be joined made of polyethylene or the like. 33 is
This is a temporary water stop plug which is provided inside both ends of the thermoplastic resin pipes 31 and 32 to be joined, and is provided with concave grooves 332 and 332 on the outer peripheral surfaces of both ends of the cylindrical body 331.
2, 332 are provided with packings 333, 333. A ridge 334 is provided along the circumferential direction on the outer peripheral surface at the center of the tubular body 331.

In the pipe joining method of this embodiment, first, as shown in FIG. 3A, an electric fusion joint 34 is mounted on one of the thermoplastic resin pipes 31 and the thermoplastic resin is attached. The pipe ends of the pipe 31 and the other thermoplastic resin pipe 32 are provided with a temporary water stop plug 33 therein and, as shown in FIG. Match. In this state, the surfaces to be fused at both ends of the pipes are sufficiently cleaned (removed of water).

Next, as shown in FIG. 3 (b), the electrofusion joint 34 is moved so as to straddle the abutting portion between the ends of the thermoplastic resin tubes 31 and 32 so as to cover it. Furthermore,
By energizing the heating wires 342 and 342 of the electric fusion joint 34 from the terminals 343 and 343, the inner peripheral surface and the outer peripheral surfaces of both ends of the thermoplastic resin tubes 31 and 32 are fusion-bonded.

(Examples) The present invention will be described below with reference to examples. Examples 1 to 4 Thermoplastic resin tubes having a diameter of 75, 100, 150, and 200 mm were placed under flowing water at a flow rate of 0.5 L / min.
By the pipe connection method of temporarily stopping water via the short pipe described with reference to FIG. The thermoplastic resin forming the thermoplastic resin tube and the electrofusion joint is a high-density polyethylene (density 0.953 g / cm3).
³ , melting point 133 ° C, melt index 0.4g / mi
n) was used. As the packing, an O-shaped cross-section made of ethylene-propylene-diene-terpolymer (EPMD) was used. Two strip-shaped test pieces were cut out from eight places in the circumferential direction, and a peel test was performed according to JWWA K145. Table 1 shows the results.

Comparative Examples 1 and 2 A diameter of 75 and 100 m similar to that used in Examples 1-4.
m, and the thermoplastic resin pipes were fused and joined by an electrofusion joint in the same manner as in Examples 1 to 4 except that the temporary stop water was not applied, and the same evaluation as in Examples 1 to 4 was performed. Was done. The results are shown in Table 1.

Embodiments 5 to 7 The same as Embodiments 1 to 4 except that the thermoplastic resin pipes having a diameter of 75, 100, and 150 mm are connected to each other by using the pipe connection method for temporarily stopping water described with reference to FIG. Then, fusion bonding was performed using an electric fusion joint, and the same evaluation as in Examples 1 to 4 was performed. The results are shown in Table 1.

Embodiments 8 to 10 Embodiments 1 to 4 are performed except that the pipe connection method for temporarily stopping the thermoplastic resin pipes having a diameter of 75, 100, 150, and 200 mm is described with reference to FIG. Were fusion-bonded with an electric fusion joint in the same manner as in Example 1 and evaluated in the same manner as in Examples 1 to 4. The results are shown in Table 1.

[0030]

[Table 1]

[0031]

Since the pipe joining method of the present invention is as described above, the ends of the thermoplastic resin pipes are joined together without completely stopping the flowing water flowing down inside. The pipe can be formed by fusion-bonding using.

[Brief description of the drawings]

FIGS. 1A and 1B are partial cross-sectional views sequentially illustrating steps of an example of a pipe joining method according to the present invention.

FIGS. 2A and 2B are partial cross-sectional views sequentially illustrating steps of another example of the pipe joining method of the present invention.

3 (a) and 3 (b) are partial cross-sectional views for sequentially explaining the steps of still another example of the pipe joining method of the present invention.

[Explanation of symbols]

 11, 12, 21, 22, 31, 32 Thermoplastic resin tube 13 Short tube 14, 24, 34 Electrofusion joint 33 Temporary waterproofing plug 131, 211, 332 Groove 132, 212, 333 Packing 142, 242, 342 Heating wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiichi Hitomi 54 Shimobuchi, Sakai-machi, Sawa-gun, Gunma Prefecture Sekisui Chemical Co., Ltd. (72) Yoshihiro Hashimoto, Inventor 54 Shimobuchi, Sakai-machi, Sawa-gun, Gunma Prefecture Sekisui Chemical Co., Ltd.F-term (reference) TH18 TN31

Claims (3)

[Claims] 1. The pipe ends of thermoplastic resin pipes to be joined are temporarily water-stopped by the packing via short pipes in which packings are mounted in concave grooves provided circumferentially on both end faces. After butt in the state and cleaning the surface of the tube end to be fused, cover the joint between the tube ends with an electric fusion joint in which a heating wire is embedded in the thermoplastic resin. A pipe joining method characterized in that an electric heating wire of the electric fusion joint is energized to melt-join between an inner peripheral surface thereof and an outer peripheral surface of both ends of the pipe. 2. The pipe ends of the thermoplastic resin pipes to be joined are packed in a concave groove provided on at least one end face of the pipe ends, and water is temporarily stopped by the packing. Butt, after cleaning the surface of the tube end to be fused, and covering the joint of the tube ends with an electric fusion joint in which a heating wire is embedded in a thermoplastic resin. A pipe joining method, characterized in that an electric current is applied to a heating wire of a fusion joint so that an inner peripheral surface of the fusion joint and an outer peripheral surface of both pipe ends are fusion-welded. 3. A temporary water plug in which the ends of thermoplastic resin pipes to be joined are packed with concave grooves provided on the outer peripheral surfaces of both ends of the tubular body, and the packing is performed. After the surfaces of the pipe ends to be fused were cleaned, a heating wire was embedded in the thermoplastic resin across the butted portions of the pipe ends. A pipe joining method, wherein an electric fusion joint is put on, and a current is applied to a heating wire of the electric fusion joint to melt-join an inner peripheral surface and an outer peripheral surface of both pipe ends.