JPH062255B2 - Pipe inner surface lining device - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a pipe inner surface lining device for an existing pipe for repairing such as forming a resin lining coating film on the inner surface of the existing pipe such as a gas pipe laid underground, in an embedded state, More specifically, the present invention relates to a pipe inner surface lining device that smoothes the movement of the lining device in the bent portion of an existing bent pipe and reliably lining the pipe inner surface.

[Prior art]

Generally, existing pipes such as gas pipes installed underground have corrosion holes in the pipes due to the passage of time after installation, which may cause a leakage phenomenon. For the purpose, repair is performed so as to form a resin lining coating film on the inner surface of the pipe. As one kind of the pipe inner surface lining repair method, a repair resin and a pig device having a pig that pushes the resin from the rear are inserted into the pipe of an existing pipe, and the pig device is pulled by a tow line. When moving the resin along the inner surface of the pipe,
A method is known in which a gap between the outer circumference of the pig and the inner surface of the pipe is used as a lining gap, and the resin flows out from the gap toward the rear of the pig to form a resin lining coating film having a predetermined thickness on the inner surface of the pipe. Examples of such prior art are Japanese Patent Laid-Open Nos. 49-13236 and 52-7.
No. 8250, Japanese Patent Laid-Open No. 53-26840, and the like. In these prior arts, a pig for pushing a resin is moved by air pressure and is pulled by a tow line connected to the pig. There is a method.

[Problems to be Solved by the Invention]

By the way, as described above, in the repair method of pushing the resin in the pipe to be repaired by the pig to form the lining coating film on the inner surface of the pipe, in the method of propelling the pig by the air pressure, leakage due to the applied air pressure There is a risk that the blocking effect of the part will become insufficient and the phenomenon that the leaked part will expand will occur, and it was unsuitable for repairing gas pipes and the like. In addition, in the method of pulling the pig with a tow cable, if the pipe to be repaired is a straight pipe, the pig can move smoothly, but if it is a bent pipe, the pig is caught in the bent portion. It is apt to occur, and moreover, the tow rope moves while being in contact with the inner wall of the in-tube bent portion and being bent, so that the tow resistance increases and it is difficult to smoothly move the pig. That is, as shown in FIG. 4, the tow cable 4 connected to the lining pig 21 having an outer diameter slightly smaller than the inner diameter of the pipe to be repaired is pulled, and the resin C on the front side of the lining pig 21 is attached to the peripheral surface of the lining pig 21. When the pipe to be repaired has a bent portion 1a when further flowing out and forming a uniform lining coating film on the inner surface of the pipe, the tow line 4 contacts the inner wall of the bent portion 1a and moves while being bent. . And resin pig 21
The lining pig as it approaches the bent part 1a of the bent pipe.
The force for moving 21 in the traveling direction becomes gradually smaller, and the force for pressing the lining pig 21 against the inner wall of the pipe becomes gradually larger, so that the required traction force is greatly increased. Moreover, the tow line 4 is provided with a lining pig when passing through the bent portion 1a.
21 has a drawback in that it cannot effectively give the turning force required to change its traveling direction, and the lining pig 21 is easily caught. Therefore, in order to eliminate the above-mentioned drawbacks, as shown in FIG. 5, one end of a plurality of flexible linear members 30 is attached to the outer periphery of the lining pig 21, and the other ends are converged to draw a tow line. It is known that a flexible tow cord 31 in the form of an envelope cone, which is fixed to the cable 4, is provided. However, when forming a lining coating film on the inner surface of the pipe using the lining pig 21 provided with the flexible tow rope 31 described above, when the lining pig 21 approaches the bent portion 1a of the bent pipe,
Although the flexible traction line 31 can prevent the increase in the required traction force at a portion in contact with the inner wall of the pipe, the flexible traction line 31 on the side in contact with the inner wall of the pipe is slackened to bend the bent portion 1a. There is a problem that it is difficult to effectively prevent the lining pig 21 from being caught by the lining pig 21 and smoothly apply the lining. The present invention has been made for the purpose of solving the above-mentioned problems.

[Means for Solving the Problems]

In order to achieve this object, the device according to the present invention inserts a repair resin C and a pig device 2 having pigs 21 to 23 for pushing the resin C from the rear into the pipe of the existing pipe 1,
In the lining device for pulling the pig device 2 by the tow cable 4 to let the resin C flow out to the rear of the pig to form a lining coating film on the inner surface of the pipe, the pig device 2 has a plurality of lining pigs 21-23. Are connected to the tow cable 4 with a space of, and each of the rear portions of the front pigs 21, 22 is formed to have a length substantially equal to the space between the rear pigs 22, 23 and is made of a spring member or the like. The pulling rods 40, 40 having flexibility are extended, and the pulling rods 40, 40 of the front pigs 21, 22 are rotatably supported by the pulling points 41, 41 of the rear pigs 22, 23. When the device 2 moves in the bent portion 1a of the pipe, the tow rods 40, 40 of the front pigs 21, 22 are repulsed toward the center line direction of the pipes at the pull points 41, 41 of the rear pigs 22, 23. It is characterized in that it is configured to be pulled.

[Action]

With the above structure, even when a curved pipe is used in the repair section, the lining rod in the curved portion of the curved pipe is pulled while the subsequent lining pig is always elastically bulged toward the center line of the pipe by the traction rod. The lining coating film on the inner surface of the pipe is made to have a uniform thickness and the traction force applied to the traction line of the pig apparatus is reduced.

【Example】

Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a pipe inner surface lining device according to the present invention, FIG. 2 is an operation explanatory view of the pipe inner surface lining device according to the present invention, and FIG. 3 is a schematic view showing an entire configuration of a repair construction device according to the present invention. In the figure, reference numeral 1 is an existing pipe to be repaired. In the case of a gas pipe, this existing pipe 1 is a pipe that is commonly called a “branch pipe” and is laid under a road or the like. Since there is a possibility that a leakage phenomenon may occur, repair is performed by forming a resin lining coating film on the inner surface of the pipe for the purpose of repairing leakage or preventive maintenance. At the time of this repair work, the existing pipe 1 is divided into repair sections L each having a length (for example, 100 m) suitable for repair, and the separation opening ends 11 and 12 of the existing piping 1 are pits A and B opened on the ground.
Expose inside. Then, the insertion guide tube 5 is connected to one separation end 11, and the extraction guide tube 6 is connected to the other separation end 12. The insertion guide tube 5 is provided with a resin inlet port 5a having an opening / closing cock 52 and an air vent port 5b also having the opening / closing cock 53, and the resin inlet port 5a includes a hose 7a. So that the repair lining resin C described later from the resin supply tank 7 can be injected into the pipe by the filling pressure of the compressed air from the small compressor 7c driven by the generator 7b. is there. Further, the other outlet guide tube 6 is provided with a resin discharge port portion 6a for discharging residual resin and a negative pressure introduction port portion 6b,
The negative pressure introducing port 6b is communicated with the vacuum pump 10 via the pressure adjusting unit 10a, and the negative pressure by the vacuum pump 10 can be introduced into the existing pipe 1 through the negative pressure introducing port 6b. There is. A tow cable 4 is passed through the existing pipe 1 through the opening at the tip of the insertion guide tube 5, and the tip of the tow cable 4 is drawn out from the other guide tube 6 and wound by a winch 9. Lining pig device 2 attached to tow line 4
Are introduced into the tube through the tip opening of the insertion guide tube 5. At the time of this introduction, the resin injection port 5a is provided on the front side of the pig apparatus 2.
The lining resin C for repairing is injected from. The lining resin C used here is, for example, a room temperature curing type two-liquid type resin liquid, and an amount sufficient to form a resin lining coating film of a predetermined length on the inner surface of the repair section L over the entire length of the tube. The resin is injected at once, and after this injection, the pig apparatus 2 is pulled by winding the tow line 4, so that the pig apparatus 2 moves the lining resin C injected on the front side thereof along the inside of the pipe. It is possible to push from the entrance side to the exit side. As shown in FIG. 1 and FIG. 2 in an enlarged manner, the pig apparatus 2 includes a plurality of lining pigs 2 at the rear side of a shell-shaped lining pig 21 with a predetermined facing interval.
The outer diameter of these lining pigs 21,22,23 is formed to be slightly smaller than the inner diameter of the existing pipe 1 to be repaired, and is the same as the inner surface of the pipe. It is formed so as to have a predetermined lining gap therebetween. In such a structure, the pig apparatus 2 is pulled by winding the tow line 4, and the lining resin C injected to the front side is pulled.
When the resin is pushed along the inside of the pipe from the inlet side to the outlet side, the resin C sequentially moves from the pig 21 to the subsequent pig 22, and the pigs 22 and 23.
The lining coating film of resin C having a uniform thickness is formed on the inner surface of the existing pipe 1 by moving it to the front side of the lining pig 23. Here, by properly selecting the number of lining pigs and the lining gap of the pig apparatus 2, even when the resin amount is large and the resin pressure is large as in the previous stage of the repair section, the resin amount is increased due to the progress of repair. Even in the middle and rear stages of the repair section where the resin pressure decreases and the resin pressure drops, the resin C leaks through the gap between the outer periphery of the pig in the front stage and the inner periphery of the existing pipe 1 to the pig in the rear stage, and this is repeated a plurality of times. As a result, the pressure difference (resin pressure) is sequentially attenuated, and the resin pressure on the front side of the lining pig 23 becomes substantially constant regardless of the amount of resin. In the previous stage of the repair section where the amount of resin is large, the above-mentioned pressure adjusting unit 10a largely controls the negative pressure applied to the inside of the pipe in the advancing direction of the lining resin C by the vacuum pump 10, while the repair progresses. When the amount of resin decreases, the negative pressure may be controlled to decrease accordingly. When such control is also used, when the resin amount is large in the preceding stage of the repair section (when the resin pressure is large), the negative pressure introduced into the pipe on the front side in the traveling direction of the resin C is large, and the suction due to the negative pressure is large. Due to the action, a phenomenon in which the resin C is pulled toward the traveling direction occurs, so that the resin pressure generated on the rear side of the moving resin C is reduced, while the resin pressure is reduced due to the decrease in the resin amount. In the middle stage and the latter stage, the negative pressure introduced into the pipe is controlled to be small, and the suction action of the resin C due to the negative pressure is weakened, so that the resin C moving in the pipe in the repair section is completely affected by the change in the resin amount. The resin pressure is controlled to be substantially constant without being affected. Further, in such a configuration, in the pig apparatus 2, a plurality of lining pigs 22, 23 are connected to the rear side of the lining pig 21, and the respective lining pigs 21 and 22 and 22 and 23.
In the connecting portion between and, a towing rod 40 having elasticity, which is formed of a spring member or the like extending from the rear portion of the front pig, is formed to have a length substantially equal to the gap between the rear pig and the rear rod. 40 is rotatably supported by a pulling point 41 of the rear pig. Therefore, when the pig apparatus 2 moves along the bent portion 1a in the existing pipe 1, as shown in FIG. 2, the pulling rods 40 of the front pigs 21 and 22 are bent, but the pulling points 41 of the rear pigs 22 and 23 are bent. Since it always repels and pulls 41 toward the center line in the pipe,
The pig apparatus 2 pushes the resin C along the inside of the pipe while maintaining a uniform lining gap with the inner surface of the pipe. Therefore, in such a configuration, when the pig apparatus 2 is towed by winding the tow line 4 and the resin C is pushed along the inside of the pipe, if the pipe to be repaired is a straight pipe, as described above. Although a uniform lining coating film is formed on the inner surface of the pipe,
Even when a bend pipe is used as the repair target pipe and there are a plurality of bend portions 1a in the repair section, as the pig apparatus 2 advances along the bend portion 1a as described above, the tow rod 40 of the pig at the previous stage is moved. Since the pulling point 41 of the rear-stage pig is elastically pulled in the direction of the center line in the pipe while bending, the uniform lining coating film can be formed on the inner surface of the pipe without increasing the required pulling force.

【The invention's effect】

Thus, according to the present invention, even when a bent pipe is used as the pipe to be repaired and there are a plurality of bent portions in the repair section, the resin injected into the pipe is pushed by the pig device to line the inner surface of the pipe. When forming a coating film, the resin pressure on the front side of the lining pig can be made constant regardless of the amount of resin, and the pulling point of the pig device is moved closer to the center line side of the pipe inner surface as the pig device approaches the bending part. Therefore, it is pulled while being pulled, and a problem such as an increase in frictional resistance when pulling the pig device as in the conventional device is eliminated. Also, because the traction resistance in the repair section that has a bend is reduced,
The pig device is smoothly moved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a pipe inner surface lining device according to the present invention, FIG. 2 is an operation explanatory view of the pipe inner surface lining device according to the present invention, and FIG. 3 is a schematic diagram showing an entire configuration of a repair construction device according to the present invention. FIG. 4 is an operation explanatory view of a main part showing a conventional embodiment, and FIG. 5 is an operation explanatory view of a main part showing a further conventional embodiment. 1 ... Existing piping, 1a ... Bends, 11,12 ... Separation openings, 2 ...
Pig device, 21, 22, 23 ... Lining pig, 4 ... Traction line, 40 ... Traction rod, 41 ... Traction point, 5 ... Insertion guide tube, 5a ... Resin injection port, 5b ... Air vent port, 6 ... Derivation guide Pipe, 6a ... residual resin discharge port, 6b ... negative pressure inlet port, 7 ... resin filling tank, 7a ... hose, 7b ... generator, 7c ... compressor, 9 ... winch, 10 ... vacuum pump, 10a ... pressure adjustment Unit, C ... Lining resin.

Claims (1)

[Claims] 1. A repair resin (C) is provided in the pipe of the existing pipe (1),
Insert the pig device (2) having the pigs (21-23) pushing the resin (C) from the rear, and pull the pig device (2)
In the lining device that draws the resin (C) to the rear of the pig by pulling by (4) to form a lining coating film on the inner surface of the pipe, the pig device (2) is a plurality of lining pigs (21 to 23).
Are connected to the tow cable (4) at a predetermined interval, and are formed at the rear of the front pigs (21, 22) to a length approximately equal to the interval with the rear pigs (22, 23). , And an elastic tow rod (40, 40) composed of a spring member or the like is extended, and the tow rod (40, 40) of the preceding pig (21, 22) is a tow point of the rear pig (22, 23). When the pig device (2) moves along the bent part (1a) of the pipe, the tow rod (40, 40) of the preceding pig (21, 22) is pivotally supported by the (41, 41). The pipe inner surface lining device is characterized in that the pulling point (41, 41) of the rear stage pig (22, 23) is pulled in a state of being resilient toward the center line direction in the pipe.