JPH0515026A - Method of laying sub duct in conduit line - Google Patents

Abstract

PURPOSE:To lay a flexible protective pipe in a conduit line as a sub duct by pulling out a control cable. CONSTITUTION:If a traveling device 3, where a slender mover 1 consisting of a control cable 1A and a flexible protective pipe 1B is connected to the rear, finishes the running from the laying start point 2A inside a conduit line 2 to the terminal 2B, it turns out that the slender mover 1 extends all over the division inside the conduit line 2. Separating the this slender mover 1 from the traveling device 3 and pulling out the inside control cable 1, only the flexible productive pipe 1B will remain as a subduct inside the conduit line 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of laying a sub-duct in a conduit such as a cable laying conduit.

[0002]

2. Description of the Related Art As a method for laying a conduit for accommodating a relatively small diameter cable such as an optical communication cable, that is, a sub-duct in a conduit accommodating a large diameter cable such as an electric power cable, Conventionally, a method has been implemented in which a rod for pulling in a sub-duct is first inserted into a pipe and inserted, and the rod is used to pull the sub-duct into the pipe.

[0003]

However, in the pipeline in which the power cable or the like has already been laid, the spare space in the pipeline is relatively narrow, and therefore, in the above-mentioned conventional method, it is pushed into the pipeline. Since the rod for pulling in the sub-duct cannot pass through the curved portion of the pipeline, or if the pipeline length is long, it causes buckling in the middle, so it is difficult to insert the rod over a long distance and insert it. , Therefore, there was a situation in which it was not possible to lay a pipe in the pipeline over a long distance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is an elongated moving body including a control cable and a flexible protective tube for housing and protecting the control cable. Is traveling in the pipeline from the installation start point of the pipeline toward the same end point while controlling the traveling device connected to the rear part with the control cable, and when the traveling device reaches the installation end point of the pipeline, While separating the moving body from the traveling device, the flexible protective tube in the slender moving body is cut at the starting point of installation, and the control cable in the slender moving body is extracted and withdrawn to the sending side, and the flexible protective tube is subducted. As a method of laying a sub-duct in the pipeline that remains in the pipeline as it is.

[0005]

When the traveling device travels in the pipeline from the laying start point to the end point, the elongated moving body connected to the rear part of the traveling device extends in the pipeline. When the slender moving body is separated from the traveling device and the control cable of the slender moving body is pulled out of the conduit, only the flexible protective tube of the slender moving body remains in the conduit.

[0006]

1 (a) to 1 (d) show a method of an embodiment of the present invention in the order of steps. First, a traveling device 3 that travels in the pipeline 2 is prepared as shown in FIG. In this traveling device 3, a front locking part 31 that is pressed against the inner wall surface of the pipe line 2 with a large frictional force and a rear locking part 32 that is similar to the front locking part 31 are connected by a driving part 33 that expands and contracts by a fluid pressure cylinder or the like. The front locking portion 31 and the rear locking portion 32 are alternately pressed against the inner wall surface of the pipe line 2 while the driving portion 33 is expanded / contracted, so that the pipe is just like a “scale insect”. It is possible to proceed on the road 2. Further, the imaging camera 4 is attached in front of the front locking portion 31 so that the state inside the conduit 2 can be observed and inspected.
Naturally, it is essential that the traveling device 3 be provided with a pressurized fluid supply pipe as a driving power source, an electric cable used for power supply for control, etc. Control cable 1
A is connected to the tail.

By the way, the control cable 1A is required to be protected from mechanical external force and to prevent frictional damage to the inner wall of the pipe line 2. Therefore, the control cable 1A usually has a flexible protection pipe 1B. Loosely covered. Therefore, the slender moving body 1 including the control cable 1A and the flexible protective tube 1B that houses and protects the control cable 1A is connected to the rear portion of the traveling device 3.

In the present invention, first, as described above, the traveling device 3 in which the slender moving body 1 including the control cable 1A and the flexible protective tube 1B accommodating the control cable 1A is connected to the rear portion is installed in the pipeline 2. Placed at the starting point 2A, and the traveling device 3
Is controlled by the control cable 1A to run in the pipeline 2 to the laying end point 2B. The state where the traveling device 3 has reached the laying end point 2B of the pipeline 2 is illustrated in FIG. (B). It extends into the pipeline 2 over the entire section up to 2B. It should be noted that when the traveling device 3 travels from the laying start point 2A to the same terminating point 2B, the situation in the pipeline 2 in this section can be observed and inspected by the imaging camera 4.

Next, as shown in FIG.
While the slender moving body 1 is separated from the above, only the flexible protective tube 1B of the slender moving body 1 is cut 11 at the installation starting point 1A.

Next, as shown in FIG. 3D, the control cable 1A together with the cutting base of the protection tube 1B is pulled out from the protection tube 1B extending into the conduit 2 toward the installation starting point 2A. Actually, the delivery drum 5 may be wound and rotated in the direction of the arrow. By doing so, only the flexible protective tube 1B remains in the conduit 2 as a sub-duct. That is, the installation of the intended sub-duct is completed in the state of FIG. It should be noted that the present invention can be carried out both when the existing cable is present in the conduit 2 and when it is not present.

[0011]

As is apparent from the above, according to the present invention, a flexible protective tube 1B which can be diverted to a sub-duct later.
However, since it is pulled by the traveling device 3 and drawn into the pipe line 2, unlike the conventional method of pushing the rod for pulling in the sub-duct into the pipe line and inserting the rod, the flexible protection tube 1B can be caught on the way. Even if the pipeline length is long, the flexible protective tube 1B, that is, the sub-duct can be easily laid in the pipeline 2 without causing any trouble. You can go.

[Brief description of drawings]

FIG. 1 is a simplified side cross-sectional view showing an example of a situation in which the method of the present invention is being carried out, sequentially illustrating steps from (a) to (d).

[Explanation of symbols]

 1 elongated moving body 1A control cable 1B flexible protective tube 2 pipeline 2A installation start point 2B installation end point 3 traveling device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Kobayashi 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Line Co., Ltd. (72) Inventor Satoshi Yamaguchi 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East Inside Kyoden Electric Co., Ltd. (72) Inventor Shigeki Yoshida 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Tokyo Electric Power Co., Inc.

Claims (1)

1. An elongated moving body (1) comprising a control cable (1A) and a flexible protective tube (1B) for accommodating and protecting the control cable (1A) is connected to a rear portion thereof. The traveling device (3)
A step of traveling in the pipeline (2) from the installation start point (2A) of the pipeline (2) toward the same end point (2B) while controlling by the control cable (1A); When the laying end point (2B) is reached, the elongated moving body (1) is disconnected from the traveling device (3), while the flexible protection tube (1B) of the elongated moving body (1) is laid at the laying starting point (2A). ) Is cut, and the control cable (1A) in the elongated moving body (1) is extracted and withdrawn to the sending side, and a flexible protective tube (1B)
Is left as it is in the pipeline (2) as a sub-duct, and the sub-duct is installed in the pipeline.