JPH0671992B2 - How to recover cables in existing piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for recovering a cable laid in an existing pipe after the inspection when the inside of the existing pipe is inspected using a cable by an in-pipe inspection pig or the like. In particular, the present invention relates to a method for recovering a cable in an existing pipe having many curved pipe portions.

[Conventional technology]

Conventionally, when collecting the cable laid in the existing pipe,
The laying cable was input from one end of the existing pipe or pulled by pulling it with a winch or the like.

[Problems to be solved by the invention]

In the conventional existing pipe cable recovery method as described above,
In the case of an existing pipe that has a large number of bent pipe parts, the friction between the laid cable that pulls out and the existing pipe is large, and especially in the bent pipe part, it is strong at the corners of the bent pipe part when the laid cable is bent. Friction caused by sliding contact was extremely large, and not only could the cable be damaged, but it could not be easily pulled out by being caught by the curved pipe section. For this reason, there is a problem in that the cable cannot be recovered, or the recovered cable is damaged and cannot be reused.

The present invention has been made to solve the problems of the conventional ones described above, and even if the existing pipe has a large number of curved pipe portions, the cable laid in the existing pipe can be easily recovered without being damaged. The purpose is to be able to.

[Means for solving problems]

The existing pipe cable recovery method according to the present invention provides a cable winding drum in the front part of a pig body that is supported by a plurality of magnet rollers and is self-propelled in the pipe.
An encoder for detecting a pig traveling distance is attached to one of the magnet rollers, and an encoder for detecting a winding amount is attached to the cable winding drum, respectively, and the cable winding is performed based on the traveling distance of the pig body. While controlling the winding speed of the drum for use, the cable laid in the existing pipe having many curved pipe portions is wound up.

[Work]

In the cable recovery method for an existing pipe according to the present invention, the pig main body having the cable winding drum attached to the front is supported in the pipe by a plurality of magnet rollers, and is self-propelled by power supply. The output from an encoder attached to one of the network rollers detects the travel distance of the pig body, and the output from an encoder attached to the cable winding drum detects the winding amount of the cable. The rotational speed of the cable winding drum is controlled so that the two detected values match when running.

Example of Invention

FIG. 1 is an explanatory view of a method for recovering a cable in an existing pipe showing an embodiment of the present invention, and FIG. 2 is a block diagram of its control system. In the figure, (1) is a pig body, which is formed in a shape and dimension that allows the existing pipe (P) to freely travel even in a curved pipe portion. (2) is a magnet roller, the peripheral surface of which is a tire shape made of rubber or the like. Reference numeral (3) is a support arm pivotally mounted on the front and rear of the pig body (1) so as to be rotatable a plurality of times. It has a mechanism that is biased to the side and transmits the rotational force of the drive motor built in the pig body (1) to the magnet roller (2). (4) is a cable winding drum attached to the front part of the pig body (1), (5) is a pair of guide rollers provided at the cable winding port, and (6) is a driving motor for pig running. , (7) is a cable winding roller, (8) is a pig running distance detection encoder attached to one of the magnet rollers (2), and (9) is attached to a guide roller (5) of the cable winding port. An encoder for detecting the cable winding amount, (10) is a controller incorporated in the pig body (1), (11) is a drive unit such as a drive motor (6) and a cable winding motor (7), ( 1
2) is a power source provided outside the existing pipe (P), which is supplied to the pig main body (1) via the recovered cable (C) laid in the existing pipe (F).

Next, a method of recovering the existing in-pipe cable configured as described above will be described. At one end of the existing pipe (P), the end of the cable (C) that has been laid (is in the installed state) is connected to the connection terminal provided on the cable winding drum (4) and is fixed. On the other hand, place the power supply (12) on the other end side of the existing pipe (P), and connect the cable (C).
Connect to. Next, the pig main body (1) is inserted from one end of the existing pipe (P), and the magnet roller (2) is pressed against the pipe wall by the urging force of the support arm (3) to connect the pig main body (1) to the pipe (1). P) is held approximately in the center. At this time, since the magnet roller (2) is attracted to the inner wall of the pipe (P) and surely makes contact with it, the pig body (1) is prevented from falling not only when traveling in the curved pipe portion but also when traveling vertically downward. It is possible to reliably travel in the existing pipe (P).

When the power (12) is turned on in this state, the controller (1
0), the drive motor (6) and the cable winding motor (7) are rotationally driven through the drive unit (11), and the pig body (1) is rotated by the magnet roller (2) to replace the existing pipe (P). ), The cable winding drum (4) is also rotated to wind the cable (C) through the guide roller (5). The traveling distance of the pig body (1) is detected by a signal from a pig traveling distance detecting encoder (8) attached to the magnet roller (2),
The cable winding amount is detected by the signal of the cable winding amount detection encoder (9) attached to the guide roller (5), and the controller (10) inputs both detection signals to detect the cable winding amount. The rotation of the cable winding motor (7) is controlled so that the value matches the pig travel distance, and the cable (C) is wound around the drum (4) without giving excessive tension or slack to the cable (C). I'll take it. In this case, the traveling speed of the pig body (1) can also be controlled by the controller (10). When the end point of the existing pipe (P) is reached, the power supply (12) is turned off and stopped.

〔The invention's effect〕

As described above, the present invention is configured to control the rotation of the cable winding drum so that the cable winding amount matches the pig travel distance. The effect is that the cable laid for inspection in the existing pipe can be easily wound and collected without damaging it.

[Brief description of drawings]

FIG. 1 is an explanatory view of an existing pipe cable recovery method showing an embodiment of the present invention, and FIG. 2 is a block diagram of its control system. In the figure, (1) is a pig body, (2) is a magnet roller, (4) is a cable winding drum, (5) is a guide roller, (6) is a pig running drive motor, and (7) is a cable. Winding motor, (8) and (9) are encoders,
(10) is a controller and (12) is a power supply.

Claims (1)

[Claims] 1. A cable winding drum is provided at a front portion of a pig main body that is self-propelled in an existing pipe supported by a plurality of magnet rollers, and an encoder for detecting a pig traveling distance is provided to one of the magnet rollers. In addition, an encoder for detecting the winding amount is attached to each of the cable winding drums, and the inside of the existing pipe is inspected while controlling the winding speed of the cable winding drum based on the traveling speed of the main body of the cable. A method for collecting cables in existing pipes, characterized in that the cables laid for the purpose are wound up.