JP3053460B2 - Pipe fitting detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting a pipe joint, and more particularly, to a method of detecting an electric fusion pipe joint and a thermoplastic synthetic resin pipe connected to the pipe joint in a hidden place such as underground. When provided, the present invention relates to a method of detecting a pipe joint from outside such as the ground, and a pipe joint for detecting the pipe.

[0002]

2. Description of the Related Art Conventionally, in order to detect the underground position of polyethylene pipes for transporting city gas and the like on the ground,
When laying the pipe, a conductor called a locating wire is arranged along the pipe, and in order to detect the buried position of the pipe on the ground, a DC or AC power is supplied to the conductor to generate an electromagnetic field, Then, the electromagnetic field is detected.

[0003]

In such prior art, the strength of the electromagnetic field detected on the ground is low depending on the condition of the soil in which the pipe is buried. Can be difficult.

A pipe joint is provided in the middle of such a pipe, and it is often necessary to repair the pipe joint. Therefore, it would be advantageous to be able to locate the fittings on the ground. As described above, conventionally, it is impossible to detect the buried position of the pipe joint on the ground.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a pipe joint which can reliably detect the position of a pipe joint and a thermoplastic synthetic resin pipe connected thereto outside the pipe. It is to be.

[0006]

According to the present invention, a first thermoplastic synthetic resin tube 12 and a second thermoplastic synthetic resin tube 1 are provided.
3 and 45 are connected by the first electro-fused pipe joint 1, and in the middle of the second thermoplastic synthetic resin pipes 13 and 45,
The third thermoplastic synthetic resin pipe 50 is branched and connected by the second electrofusion pipe joint 47, and the first electrofusion pipe joint 1 is connected to the first thermoplastic synthetic resin pipe joint body 2. And a first heating wire 5 provided inside or on the inner surface of the first pipe joint body and having a portion wound around the first pipe joint body 2.
And heating the first heating wires 5 and 6 by supplying power to the first heating wires 5 and 6 so that the first pipe joint body 2
And the first and second thermoplastic synthetic resin pipes 12 and 13 are melted and hermetically sealed, and the second electro-fusion pipe joint 47 is
Including a second thermoplastic synthetic resin pipe joint main body and a second heating wire 48 provided inside or on the inner surface of the second pipe joint main body and having a part wound around the second pipe joint main body. The second heating wire 48 is heated by supplying electric power to the second heating wire 48 to melt the second pipe joint body and the second and third thermoplastic synthetic resin tubes 13, 45; A first conductive wire 32 that is hermetically fused and provided along the first thermoplastic synthetic resin tube 12 and has one end connected to one end of the first heating wires 5 and 6; Thermoplastic synthetic resin tube 1
One end is connected to the other end of the first heating wire 5 or 6 between the first and second electrofusion pipe joints 1 and 47 along the third or third end, and the second end is connected to the second end. A second conductive wire 33 connected to one end of the heating wire 48, and a second thermoplastic synthetic resin tube 1
Along the third and fourth electric fusion joints 47, the third electric fusion joint 47 is provided on the opposite side to the first electric fusion joint 1, and has one end connected to the other end of the second heating wire 48. A conductor 44 of
A pipe joint provided along the third thermoplastic synthetic resin tube 50 and including a fourth conductor 51 having one end connected to a connection point between the one end of the second heating wire 48 and the second conductor 33. And a DC or AC power is supplied between the other end of the fourth conductor 51 and the other end of the first conductor 32 or the other end of the third conductor 44 to generate an electromagnetic field. The generated electromagnetic field is transferred to the first to third thermoplastic synthetic resin tubes 12;
3, 45, and 50, and a method for detecting a pipe joint, which is performed outside the first and second electrofusion pipe joints 1 and 47.

[0007]

According to the present invention, by supplying electric power to the heating wires 5, 6; 48 of the first and second electrofusion pipe joints 1, 47, the pipe joint body made of thermoplastic synthetic resin and connected thereto. Heat-fused with the thermoplastic synthetic resin pipe to be welded and hermetically fused, and thus the electro-welded pipe joints 1, 47 and the pipe 12; 1
After connecting the heating wire and the conducting wires 32, 33, 44, 51 provided along the tube in series, and supplying DC power or AC power, the heating wire 5, 6; 48 and the conductors 32, 33, 44, 51 generate an electromagnetic field. The heating wire has a portion wound around the pipe joint body, and therefore, the intensity of the electromagnetic field generated near the heating wire is large. Therefore, when an electromagnetic field is detected outside the pipe, the position of the pipe joint having a high intensity of the electromagnetic field can be easily known outside a concealed place such as the ground.

When the pipes are connected by a plurality of pipe joints and laid over a long distance, by detecting the position of each of these pipe joints, the pipe is laid so as to connect the detected positions. Can be deduced and the position of the tube can also be determined.

The pipe is also provided with a conductor as described above, and an electromagnetic field is generated by the conductor, and the electromagnetic field generated from the conductor can be detected outside a concealed portion such as the ground. It is possible.

[0010]

FIG. 1 is an overall sectional view of an embodiment of the present invention. Tubes 12 and 13 made of thermoplastic synthetic resin such as polyethylene are buried in the soil 31.
Are heat-sealed by the electric welding pipe joint 1 to be air-tightly connected. In the electric fusion joint 1, heating wires 5 and 6 for performing heat welding with the tubes 12 and 13 are provided, and these heating wires 5 and 6 are locating wires provided along the tubes 12 and 13. Connected to conductors 32, 33 called
2 and 13 are connected to standing pipes 34 and 35. The standing pipes 34 and 35 are connected to gas meters 36 and 37 and the like. The standing pipes 34 and 35 are made of steel. These standing pipes 3
By connecting a DC power supply 38 between 4, 4 and 35, an electromagnetic field is generated by the fitting 1 and the conductors 32 and 33,
On the ground, this electromagnetic field is detected by the detecting means 40 having the antenna 39, and thus the buried position of the pipe joint 1 and the buried positions of the pipes 12, 13 can be detected. Since the heating wires 5 and 6 of the pipe joint 1 have a portion wound in a spiral or coil shape, the intensity of the electromagnetic field generated by the heating wires 5 and 6 is large. Thus, the buried position of the pipe joint 1 can be accurately detected by reliably detecting an electromagnetic field having such a large intensity. When the pipes 12 and 13 are connected by a plurality of pipe joints 1, an electromagnetic field having a large intensity in each of the pipe joints 1 is detected, and the pipes 12 and 13 connecting the burying positions of these pipe joints are buried. It is also possible to infer and detect the position. In this case, even if the electromagnetic field generated from the conductors 32 and 33 is weak and it is difficult to accurately detect the electromagnetic field on the ground, the embedding positions of the tubes 12 and 13 where such conductors 32 and 33 are provided are determined. Can be accurately detected. AC power may be used instead of the DC power supply 38.

FIG. 2 is a cross-sectional view of the electrofusion pipe joint 1.
FIG. 3 is a perspective view showing the pipe joint 1 in a simplified manner. Pipe joint body 2 made of thermoplastic synthetic resin, for example, polyethylene
And heating wires 5 and 6 provided inside the connection holes 3 and 4 or inside the thick portion near the inner surfaces thereof,
Lead wires 9 and 10 are connected to these heating wires 5 and 6 via terminals 7 and 8. In connection holes 3 and 4, pipes 12,
13 are inserted and connected, and in this state, power is supplied to the heating wires 5 and 6, whereby
The heating wires 5, 6 are heated, and the pipe joint body 2 and the pipe 12,
13 is melted by heat and fusion-bonded to be airtight.

As the material of the pipe joint body 2 and the pipes 12 and 13, for example, in addition to polyethylene as described above,
Materials include polyolefin resins such as polypropylene, polybutene, and methylpentene. The pipe joint body 2 and the pipes 12 and 13 are used for transporting gas such as city gas and liquid such as cold and hot water. The pipes 12 and 13 are buried in the ground,
Exposed by

In the pipe joint main body 2, the portions of the heating wires 5 and 6 formed by winding a single wire in a coil shape are connected to terminals 7 and 8, respectively. Is erected on the pipe joint body 2 and is surrounded by protective tubes 14 and 15. Caps 16 and 17 made of an electrically insulating synthetic resin material are attached to ends of the lead wires 9 and 10, and the lead wires 9 and 10 are connected to connecting pieces 18 and 1 into which terminals 7 and 8 are fitted.
9 is electrically connected. The outer periphery of the lead wires 9 and 10 is covered with a coating layer made of an electrically insulating synthetic resin. The terminals 7 and 8 and the connection pieces 18 and 19 are detachable.

In joining the pipes 12 and 13 using the pipe joint 1, the ends of the pipes 12 and 13 are inserted into the connection holes 3 and 4 of the pipe joint body 2 as shown in FIG. Next, the connection piece 21 is connected to the terminal 7, and the lead wire 22 is connected to the power supply circuit 23. Similarly, the other terminal 8 is connected to the power supply circuit 23 via the lead wire 24. The power of the commercial AC power is variably supplied from the power supply circuit 23 to generate Joule heat in the heating wires 5 and 6. Therefore, a portion near the inner peripheral surface of the pipe joint body 2 and a portion near the outer peripheral surfaces of the pipes 12 and 13 are thermally melted and hermetically welded as shown in FIGS. 1 and 5 (2). After such thermal fusion bonding between the pipe joint body 2 and the pipes 12 and 13, the connecting piece 21 connected to the lead wire 22 is removed from the terminal 7, and another lead wire 24 is formed.
Is removed from the terminal 8 in the same manner.

Thereafter, as shown in FIG.
8 and 19 are fitted to the terminals 7 and 8 for electrical connection. The leads 9 and 10 are electrically connected as indicated by reference numerals 42 and 43 to conducting wires 32 and 33 which are locating wires provided along the tubes 12 and 13. The conductors 32 and 33 may be covered with, for example, an electrically insulating coating layer to prevent corrosion when buried in the ground. The connecting portions 42 and 43 between the conductive wires 32 and 33 and the lead wires 9 and 10 are covered with an electrically insulating material such as rubber or synthetic resin. afterwards,
The soil is backfilled, and the pipes 12, 13 and the pipe joint body 2 are buried underground.

Therefore, by supplying power to the conductors 32 and 33 and the heating wires 5 and 6 of the pipe joint 1 by the DC power supply 38 as described above, the intensity of the electromagnetic field detected by the detecting means 40 on the ground is shown in FIG. The peak value 46 of the electromagnetic field corresponds to the heating wires 5 and 6 of the pipe joint 1. When a pipe 45 made of a thermoplastic synthetic resin is connected to the pipe 13 via an electric fusion joint 47, conductors 33 and 44 are connected to the heating wire 48 of the joint 47, and the conductor 44 is connected to the heating wire 48 of the joint 47. By providing the DC power between the conductors 32 and 44 along the pipe 45, the peak value 49 of FIG. 7A is detected on the ground corresponding to the heating wire 48 of the pipe joint 47. Can be In this way, the buried position of the pipe joints 1 and 47 can be detected on the ground. The pipe 50 branched by the pipe joint 47 is made of a thermoplastic synthetic resin.
A power supply may be connected between the conductive wire 51 and the above-described conductive wire 32 or 44 to detect the position in the same manner as described above. Tube 50
May be a pipe to be connected to the standpipe 35. An AC power supply may be used instead of the DC power supply 38. Each of the electrofusion pipe joints 1 and 47 includes a pipe joint body made of a thermoplastic synthetic resin and heating wires 5, 6, and 48. The pipe joint 47 is provided in the middle of the pipes 13 and 45 and branched. Tube 50 is connected. One end of the conductor 32 is connected to one end of the heating wires 5 and 6, one end of the conductor 33 is connected to the other end of the heating wires 5 and 6, and the other end of the conductor 33 is connected to one end of the heating wire 48. Connected to the unit. The conductor 44 is provided on the side opposite to the pipe joint 1 with respect to the pipe joint 47, and one end of the conductor 44 is connected to the other end of the heating wire 48. One end of the conducting wire 51 is connected to a connection point between the one end of the heating wire 48 and the conducting wire 33. DC or AC power is supplied between the conductor 51 and the other end of the conductor 32 or the other end of the conductor 44 to generate an electromagnetic field. The generated electromagnetic field is transmitted to the tubes 12;
5; 50 and detected outside fittings 1, 47.

The present invention is widely applicable not only for detecting pipe joints and pipes buried underground, but also for detecting the position of pipe joints and pipes buried underwater and in other concealed parts. can do.

[0018]

As described above, according to the present invention, the first and second heating wires 5, 6; 48 provided on the pipe joint body of the first and second electrofusion pipe joints 1, 47 are provided. Electric power is supplied to the pipe joint body and the first to third thermoplastic synthetic resin pipes 1
2; 13, 45; 50 are heat-sealed and hermetically fused and connected, and the heating wires 5, 6, 48 are connected to first to fourth conductive wires 32, 33, 33 provided along the pipe. 44 and 51, and supplies DC power or AC power to generate an electromagnetic field. Since the heating wire has a portion wound around the pipe joint body, the heating wire is generated from this heating wire. The strength of the electromagnetic field is high, so that the position of the pipe joint can be easily detected outside a concealed place such as the ground. Tube 12; 13, 4
5; 50 are connected by the pipe joints 1 and 47, and by detecting the position of each pipe joint as described above, the laying position of the pipe connecting the positions of these pipe joints is estimated and detected. be able to. Since the tube also has a conductor, the conductor also produces an electromagnetic field,
It is also possible to detect the position of the tube by detecting the electromagnetic field generated from the conductor. Further, according to the present invention, the first and second thermoplastic synthetic resin pipes 12 and 13 are connected by the first electrofusion pipe joint 1, and the second thermoplastic synthetic resin pipe 13 is connected to the second electric plastic pipe 13. The third thermoplastic synthetic resin pipe 50 is branched and connected by the fusion pipe joint 47, and the first and second conductive wires 32 and 33 are connected to the first heating wires 5 and 6 of the first pipe joint 1, The second heating wire 48 of the second pipe joint 47 is connected to the second and third conductors 33 and 44, and the fourth conductor 51 provided along the branched pipe 50 includes the second conductor 33 and the second conductor 33. The DC or AC power supply is connected to the connection point with the heating wire 48, so that the DC or AC power is supplied between the other end of the fourth conductor 51 and the other end of the first conductor 32, or the other end of the third conductor 51. And the other end of the third conducting wire 44, and an electromagnetic field generated thereby is detected outside. Rukoto can. In this way, the first to third pipes 12 provided in the concealed place over a long distance with a relatively simple operation;
13, 45; 50 and the buried position of the first and second electrofusion pipe joints 1, 47 can be easily detected.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the electric fusion joint 1;

FIG. 3 is a simplified perspective view of the electrofusion pipe joint 1;

FIG. 4 is a cross-sectional view illustrating an operation at the time of heat fusion bonding using the electrofusion pipe joint 2.

FIG. 5 is a partial cross-sectional view showing a state where the pipes 12 and 13 are connected using the heat fusion pipe joint 1;

FIG. 6 shows the heating wires 5 and 6 and the conducting wires 32 and 3 of the heat-fused pipe joint 1.
FIG. 3 is a cross-sectional view showing a state of connection with the third embodiment.

FIG. 7 is a diagram for explaining an operation for detecting the buried position of the electro-fusion pipe joints 1, 47 according to one embodiment of the present invention on the ground.

[Explanation of symbols]

 1,47 Electric fusion joint 5,6,48 Heating wire 12,13 Tube 38 DC power supply

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-78689 (JP, A) JP-A 62-7087 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01V 3/08

Claims (1)

(57) [Claims] 1. A first thermoplastic synthetic resin pipe (12) and second thermoplastic synthetic resin pipes (13, 45) are connected by a first electrofusion pipe joint (1), and a second thermoplastic synthetic resin pipe (1) is provided. In the middle of the synthetic resin tubes 13 and 45, the second
The third thermoplastic synthetic resin pipe 50 is branched and connected by the electro-fusion pipe joint 47 of the first embodiment. The first electro-fusion pipe joint 1 is composed of the first thermoplastic synthetic resin pipe joint body 2 and The first fitting is provided on the inside or inside surface of the first fitting body,
And heating the first heating wires 5 and 6 by supplying power to the first heating wires 5 and 6, the first heating wires 5 and 6 having portions wound around the pipe joint body 2. The first pipe joint body 2 and the first and second thermoplastic synthetic resin pipes 12 and 13 are melted and hermetically fused, and the second electro-fusion pipe joint 47 is formed of a second thermoplastic synthetic resin. A second pipe joint body provided inside or on an inner surface of the second pipe joint body;
Heating wire 48 having a portion wound around the pipe joint body of FIG.
By supplying electric power to the second heating wire 48, the second heating wire 48 is heated, and the second pipe joint body and the second and third thermoplastic synthetic resin tubes 13, 45; A first conductive wire 32 that is melted and hermetically fused and provided along the first thermoplastic synthetic resin tube 12 and has one end connected to one end of the first heating wires 5 and 6; Along the second thermoplastic synthetic resin tubes 13 and 45, the first
One end is connected to the other ends of the first heating wires 5 and 6, and the other end is connected to one end of the second heating wires 48 between the first and second electric fusion fittings 1 and 47. Along the second conducting wire 33 and the second thermoplastic synthetic resin tubes 13 and 45,
A third conductive wire 44 provided on the side opposite to the first electrofusion fitting 1 with respect to the electrofusion fitting 47 and having one end connected to the other end of the second heating wire 48; A method of detecting a pipe joint provided along a synthetic resin pipe 50 and including a fourth conductive wire 51 having one end connected to a connection point between the one end of the second heating wire 48 and the second conductive wire 33. A DC or AC power is supplied between the other end of the fourth conductor 51 and the other end of the first conductor 32 or the other end of the third conductor 44 to generate an electromagnetic field. Pipe joints characterized in that the detected electromagnetic field is detected outside the first to third thermoplastic synthetic resin pipes 12; 13, 45; 50 and the first and second electrofusion pipe joints 1, 47. Detection method.