JPH0243547B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention is useful when, for example, repairing an empty tube body of an underground conduit that forms a cable lead-in conduit for wiring telecommunications cables etc. underground from inside the pipe while it is still installed. This invention relates to a pigging device used for repairing underground pipelines.

[Technical background of the invention]

Underground conduits for wiring telecommunications cables, etc. underground usually consist of multiple pipe bodies (steel pipes, cast iron pipes, or hard vinyl pipes) running between vertical holes such as manholes in multiple stages above and below. Even if multiple rows are arranged on the left and right, they are constructed by laying underground in order under roads etc. to form a conduit.Multiple rows of underground conduits are constructed in advance and the cables to be routed are etc., by selecting an arbitrary empty pipe and leading it in for installation. By the way, many of the pipe bodies of existing underground conduits are made of steel pipes or cast iron pipes connected by pipe joints. Rust develops in such metal pipe bodies over many years, and the rust gradually spreads within the pipe, eventually forming a "knot-like" phenomenon that reduces the effective diameter of the pipe. In addition, because the above-mentioned underground pipes are installed under roads, the joint condition of the pipe joints changes due to the load of vehicles passing on the road, vibrations, earthquakes, etc. Gaps are created, and foreign matter such as water and earth and sand can enter the pipes through these gaps and corrosion holes that occur in the pipes themselves, causing the pipes to become clogged. Due to these reasons, in underground pipelines that have been installed for a certain number of years, even if you try to insert a new cable into the empty pipeline, it may become impossible to insert it. It is being considered to repair empty pipes from inside the pipes while they are still installed.

[Technical problem of the invention]

In the above-mentioned repair of the pipe body, it is necessary to repair the pipe body by filling the gap at the pipe joint with resin to improve the sealing performance of the joint. The problem in this case is that if there is a leak at the joint of the pipe, the resin will be filled smoothly, but if there is no leak, the air in the gap will prevent the resin from filling. It is. In addition, when performing construction to fill the gap between the joints of pipes with resin, a pig is introduced into the pipe to be repaired with the resin placed on the front side of the pig, and the pig is pulled to push the resin from behind. However, during this movement process, resin pressure is generated in the resin due to viscous resistance due to contact with the inner surface of the tube, so even if this resin pressure is generated, the resin will not move further than the circumferential surface of the towing pig. In order to prevent the towing pig from escaping backwards, the towing pig must be inserted into the pipe with some compression so that the circumferential surface slides in airtight contact with the inner surface of the pipe. In this way, when the towing pig passes behind the resin and passes through the position of the pipe joint where resin has been filled, the expansion pressure of the towing pig fills the gap in the joint. Immediately after filling, the resin is pushed out from within the gap into the pipe again, and this hardens into a raised state within the pipe, causing a phenomenon that reduces the pipe's inner diameter, causing problems when passing cables, etc. through the repaired pipe. There is a problem.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pigging device for repairing underground pipelines that can reliably fill the gap between the joints of pipes with resin without causing the above-mentioned problems. It is something to do.

[Structure of the invention]

In order to achieve this purpose, the pigging device according to the present invention has a configuration in which a replacement pig is connected to the leading end, a towing pig is next, and a leveling pig is connected to the rear in the moving direction of the towing rope inserted into the pipe to be repaired. , the displacement pig is movable with respect to the tow rope, and has a resin-filled groove and an air escape groove formed on the circumferential surface, and the tow pig is cylindrical and fixed to the tow rope. Its circumferential surface is in airtight contact with the inner surface of the pipe, and the resin placed between it and the replacement pig at the front can be pulled.The rear leveling pig has an outer diameter slightly smaller than the diameter of the pipe to be repaired. It is characterized by being fixed to the tow rope.

【Example】

Hereinafter, one embodiment of the present invention will be described based on the drawings. The illustrated embodiment shows an example in which the present invention is applied to the repair of an underground conduit laid for wiring telecommunication cables underground, and FIG. 1 shows the entire example of the repair work. It is schematically shown, and reference numeral 1 in the figure indicates an underground pipe to be repaired. This underground conduit 1 consists of a plurality of pipes (usually made by connecting steel pipes, cast iron pipes, or hard vinyl pipes with a diameter of 50 mm to 100 mm to a predetermined length with pipe fittings) at predetermined intervals. For example, a total of nine pipes are arranged in three rows vertically and three rows horizontally to form one pipe group, and these pipes are sequentially laid underground under a road through manholes (or handholes) A and B. This is formed by forming multiple rows of conduits. Telecommunication cables and the like are wired in this underground conduit 1, and the multiple rows of conduits are comprised of cable passages and empty pipes through which cables are not inserted. This relates to a pigging device used when repairing this empty pipeline. When repairing the empty pipes of the underground pipe 1, in the construction method shown in the figure, the area between the manholes A and B, which are the openings at both ends of the underground pipe group, is treated as one section of repair, and the area between each manhole A and B is repaired above ground. , a work vehicle 2 equipped with winch devices 31 and 32 for the traction rope 3 inserted into the empty pipe 11 to be repaired, and resin supply devices 4 and 5 for supplying resin into the empty pipe 11, respectively.
1 and 22 are arranged. Each of the resin supply devices 4 and 5 installed in the working vehicles 21 and 22 includes a main resin tank 41 and 51 and a curing agent tank 42 and 5, respectively.
2, and these tanks 41, 42 and 5
The resin outlet pipes 43, 44 and 53, 54 sent out from each tank 1, 52 are connected to a known two-liquid mixer (static mixer) 45, 55, where the main resin resin and curing agent are mixed. It is of the type that is sent out in a mixed state. Note that each main agent tank 41, 51 is connected to a vacuum pump 46, 5, respectively.
6, so that bubbles generated in the main resin can be defoamed. In order to introduce the resin from the resin supply devices 4 and 5 into the empty pipe 11 to be repaired, each manhole A,
Inside B, guide tubes 12 and 13 connected to the opening of the empty tube 11 are provided. Each guide tube 12,
13 are provided with resin injection ports 14 and 15, respectively, and resin discharge side pipes 47 and 57 of the two-liquid mixers 45 and 55 are connected to the resin injection ports 14 and 15, respectively.
are connected to each other so that resin can be introduced into the hollow tube 11 from both manhole A and B sides separately through the guide tubes 12 and 13. In addition, pulleys 33 and 34 are provided in each manhole A and B for detouring a towing rope 3 as a towing cable inserted into the empty pipe 11 to be repaired, and the towing rope 3 is Both ends of the rope are pulled out from the ground through each manhole A, B and connected to winch devices 31, 32, and by alternately winding and unwinding each winch device 31, 32, the tow rope 3 is Empty pipe 1 with the distance between manholes A and B as the stroke
1 so that it can be towed in a reciprocating direction. A pig device of the present invention shown in FIG. 2 is attached to the towing rope 3, and thereby a resin filling process described below is performed. The pig device according to the present invention has a replacement pig 61 at the head of the towing rope 3 inserted into the empty pipe 11 to be repaired, a towing pig 62 next, a leveling pig 63 at the rear, and a towing rope 3 inserted into the empty pipe 11 to be repaired. These pigs 6 are connected in the middle so that they can be replaced.
1, 62, and 63 are all made of elastic material. The replacement pig 61 has an outer diameter such that its circumferential surface slides in airtight contact with the inner surface of the empty pipe 11 to be repaired, and is slidably inserted into the towing rope 3. When moving within the pipe,
Due to the sliding resistance with the inner wall of the tube, a required pressure can be applied to the resin C placed between it and the rear towing pig 62. In addition, this replacement pig 61 includes:
As shown in FIG. 3, on the outer periphery of the pig body 61a, which has a cylindrical shape, there is an air escape groove 61b whose end opens toward the front end, and an air escape groove 61b at a different position in the circumferential direction relative to the air escape groove 61b. A resin guide groove 61c is provided with a portion opening toward the rear end, and both grooves 61b,
61c are formed so that their inner ends overlap each other in the longitudinal direction (traction direction). The towing pig 62 has a cylindrical shape fixed to the towing rope 3, and its circumferential surface slides in airtight contact with the inner surface of the pipe to be repaired, and the leading replacement pig 61
The resin C placed between the tube and the tube can be pulled and moved along the inside of the tube. In addition, the leveling pig 6 on the rear side
3 has an outer diameter slightly smaller than the diameter of the pipe to be repaired, and is fixedly attached to the tow rope 3. In the resin filling process, the pigs 61, 6
2 and 63 in one manhole (in the illustrated example, the left manhole A), the leading replacement pig 61 is inserted into the pipe from the end of the guide pipe 12 by pulling the rope 3, and the second When the towing pig 62 is inserted into the end of the guide tube 12, the resin injection port 14 is opened and the filling resin C is injected from the resin supply device 4. The filling resin C used here is a two-component resin liquid that cures at room temperature, with a mixing ratio of the main resin and curing agent of 3 to 1:1 by weight, and a contact curing time of 3 to 5 hours. . The components of the main agent are, for example, 40 parts of bisphenol A type diglycidyl ether, bisphenol A side chain type diglycidyl ether
40 parts Polyfunctional diluent 20 parts Filler 10 parts The components of the curing agent include, for example, modified aliphatic polyamine 20 parts modified aliphatic polyamine 20 parts polyamide 10 parts filler 5 parts. Ru. By injecting the resin C, the leading replacement pig 61
Resin C is interposed between the towing pig 62 and the towing rope 3, and in this state the towing rope 3 is pulled toward the second manhole B on the right side. As a result, the resin C is pushed by the traction pig 62 and introduced into the empty tube 11, and is moved to the right inside the tube at a predetermined traction speed. The pressing force from the displacement pig 61 acts, and the resin itself generates considerable pressure due to viscous resistance due to contact with the inner wall of the pipe.
When the resin C passes through the pipe joint part 11a of the empty pipe 11,
The resin C is filled into the gap of the pipe joint portion 11a at the above filling pressure. At this time, if there is a leak in the pipe joint 11a, the air in the joint gap escapes to the outside through the leak due to the resin being press-fitted by the above-mentioned filling pressure, so that the gap is completely filled with resin. However, if no leakage occurs in the pipe joint 11a, the air within the gap is compressed, which may inhibit the filling of the resin C into the joint gap. In this case, as described above, the replacement pig 61 has an air escape groove 61b on the outer periphery of the pig body 61a, the end of which opens toward the front end, and an air escape groove 61b at a different position in the circumferential direction with respect to the air escape groove 61b. A resin guide groove 61c is provided that opens at the end side, and when the replacement pig 61 configured in this way is used, the pipe joint portion 11
During the process in which the replacement pig 61 reaches and passes through a, the inside of the joint gap becomes in communication with the space in front of the replacement pig 61 via the groove 61b, and the air in the gap flows through the groove 61b. Since the resin C escapes into the front space, it passes through the other groove 61c.
The resin C flows around the outer periphery of the pig body 61a into the gap of the pipe joint 11a due to the resin pressure, and as a result, the resin C is replaced and filled accurately. In this way, the resin C is pushed by the pulling pig 62 and passes through the pipe line of the empty pipe 11, so that each pipe fitting part 11a interposed on the pipe line is sequentially filled with resin into the joint part gap, and this The pipe joint portion 11a is repaired with resin filling to improve its sealing performance. In addition, in this resin filling process, the towing pig 62
When pushing the resin C and moving inside the pipe, the towing pig 6
As described above, 2 is designed to slide in airtight contact with the inner surface of the pipe so that even if resin pressure is generated in the resin C on the front side, the resin will not escape backward from the circumferential surface of the traction pig 62. Therefore, the towing pig 62 is
When passing the position of the pipe joint 11a filled with resin by the leading displacement pig 61, the resin filled in the joint gap is filled with the expansion pressure of the pulling pig 62 as shown in FIG. Later on, there is a tendency to be pushed out from within the gap again, but in this case, the towing pig 6
A leveling pig 63 is connected to the rear of the tube 2, and this acts to smooth the bulging resin a onto the inner surface of the tube, so that the inner diameter of the tube is not reduced by the bulging resin a.

【Effect of the invention】

Thus, according to the pig device according to the present invention, the following effects can be obtained. For each joint of the pipe body to be repaired, regardless of whether or not there is a leak in that joint, the displacement pig 61 at the top discharges the air stagnant in the joint gap and fills the gap. Replace resin,
Since it can be filled, resin filling is reliable and repairs can be made to accurately improve the sealing performance of the joint. Moreover, during this repair, even if the expansion pressure of the traction pig 62 causes the resin filled in the joint gap to be pushed out from the gap into the pipe again after filling, the leveling pressure connected to the rear of the traction pig 62 Since the swollen resin can be applied in a series of steps using a pig so that it is smoothed onto the inner surface of the pipe, there is no problem such as the swollen resin shrinking the pipe inner diameter and hindering cable insertion. The inner surface of the pipe joint part of the pipe body can be repaired.

[Brief explanation of the drawing]

Fig. 1 is a sectional view schematically showing the entire repair work example using the pigging device according to the present invention, Fig. 2 is an explanatory diagram showing a resin filling process using the pigging device according to the present invention, and Fig. 3 is a replacement FIG. 4, a perspective view of the pig, is an explanatory diagram of the phenomenon that occurs inside the pipe during the resin filling process. 1... Underground pipe, 11... Empty pipe, 12, 13...
... Guide tube, 14, 15 ... Resin injection port, 21,
21...Work vehicle, 3...Tow rope, 31, 32
... Winch device, 33, 34 ... Pulley, 4, 5
... Resin supply device, 41, 51 ... Main agent tank,
42, 52...Curing agent tank, 43, 44, 5
3,54... Outlet pipe, 45,55... Two liquid mixer, 46,56... Vacuum pump, 47,57...
... Resin discharge side pipe of two-liquid mixer, 61 ... Displacement pig, 61a ... Pig body, 61b ... Air escape groove, 61c ... Resin guide groove, 62 ... Traction pig, 63 ... Equalizer Shi pig.

Claims (1)

[Claims] 1 A repair pig device that introduces a plurality of pigs into the pipe of an underground conduit with resin interposed between the pigs, tows the pigs along the pipe, and fills the gap at the pipe joint with resin. In this method, the plurality of pigs have a configuration in which a replacement pig is connected at the front in the moving direction, a traction pig is next, and a leveling pig is connected at the rear. The towing pig has a cylindrical shape fixed to the towing cable, and its peripheral surface is in airtight contact with the inner surface of the tube, and the resin placed between it and the leading displacement pig is inserted from behind. A pig device for repairing underground pipelines, characterized in that the leveling pig has an outer diameter slightly smaller than the diameter of the pipe to be repaired and is fixedly attached to a tow cable.