JP2001320810A - Cable passing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable passing method when a cable is connected from a main conduit to a user facility via a branch conduit line. SOLUTION: This is a cable passing method for laying a cable into a main conduit P and a branch conduit line FP, connected to the main conduit P and having a smaller diameter than that of the main conduit. To the tip of a cable C to be laid, a parachute Pa is connected, and to the end part of the main conduit P at the side where the cable C is laid, a blower B is connected. By driving the blower B in the closed state of the end of the opposite side to the one of the main conduit P to which the blower B is connected, the tip of the cable C where the parachute Pa is linked is inserted with the parachute Pa ahead from the end of the branch conduit FP of the opposite side to the one connected to the main conduit P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying various cables such as optical cables through a branch pipe connected to a main pipe.

[0002]

Generally, communication cables such as optical cables and other various cables are mostly laid by being inserted into pipelines buried underground. For example, communication cables such as optical cables are It is laid by being inserted into the existing communication pipeline (main pipe) buried underground.

[0003] The connection of the communication cable laid in the main pipe to each user facility or the like is performed by a branch pipe provided between the main pipe P and the user facility U as shown in FIGS. This is performed via the road FP.

The branch pipe FP has a diameter smaller than the diameter of the main pipe P, and is piped so as to be connected to the main pipe P for each user facility U. When connecting the communication cable laid in the main pipe P to the user facility U, first, the user facility is connected to the work handhole H1 and the branch pipe line FP provided in the middle of the main pipe P. It is necessary to pass a communication cable between the work box (hereinafter, referred to as a small hall) H2 provided on the U side. It is an object of the present invention to provide a cable routing method for connecting a cable from a main pipe to a user facility via a branch conduit as described above.

[0005]

According to a first aspect of the present invention, there is provided a cable connecting method, comprising: a branch pipe having a diameter smaller than a diameter of a main pipe and a main pipe connected to the main pipe; A method of laying a cable on a road with a cable laying method, in which a parachute-like traction tool is connected to a tip of the cable to be laid, and a suction device is connected to an end of the main pipe on a side where a cable is laid. Then, the suction device is driven in a state where the end of the main pipe opposite to the side to which the suction device is connected is closed, and the tip end of the cable to which the parachute-like traction tool is connected is branched. It is characterized in that a parachute-like traction tool is inserted first from the end of the conduit opposite to the side connected to the main pipe.

In the cable wiring method according to the first aspect of the present invention, a parachute-like traction tool is connected to a leading end of the cable to be passed when the cable is passed.
A cable is inserted into the branch conduit from the end opening to a small hole or the like provided in the middle of the branch pipe, with a parachute-like traction tool at the head.

At this time, the end of the main pipe opposite to the side to which the suction device is connected is closed with the connecting portion between the main pipe and the branch pipe line therebetween, and the suction device is driven in this state. As a result, the inside of the main pipe and the branch pipe are brought into a negative pressure state.

By driving the suction device, the parachute-like traction tool attached to the distal end of the cable is sucked in the direction of the connection with the main pipe, and the cable is drawn into the branch conduit.

When the parachute-like traction tool reaches the junction between the branch pipe and the main pipe and enters the main pipe, when the parachute-like traction tool is present in the branch pipe, the diameter of the branch pipe becomes smaller. The parachute-like traction tool, which had spread along with it, spreads even further according to the diameter of the main pipe.

[0010] Thus, the parachute-like traction tool which receives the negative pressure generated by the suction of the suction device draws the cable from the branch line into the main pipe, and further pulls the inside of the main pipe in a desired direction.

As described above, according to the first aspect,
Since the main pipe and the branch pipe are made to have a negative pressure and the cable is pulled by the suction force, the cable is pulled from the branch pipe having a smaller diameter than the main pipe in the target direction of the main pipe. The line is made reliably.

[0012] According to a second aspect of the present invention, in addition to the configuration of the first aspect, the parachute-like traction device connected to the distal end of the cable enters the main pipe from the branch conduit. In this case, the end of the main pipe on the side opposite to the side to which the suction device is connected is released, whereby the differential pressure between the front and rear of the parachute-like traction device increases in the main pipe, and The pulling of the cable in the pipe is ensured.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, when a parachute-like traction tool connected to the distal end of the cable enters the main pipe from the branch pipe line. The suction pressure by the suction device is reduced, whereby the differential pressure before and after the parachute-like traction tool is reduced in the main pipe, and the traction force applied to the cable in the main pipe is leveled. As a result, the pulling of the cable is performed securely and securely.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 are process explanatory views showing an example of an embodiment of a cable passing method according to the present invention. In FIGS. 1 and 2, a blower B is connected to an end of the main pipe P that opens into the handhole H1 so as to perform suction in the main pipe P.

When laying various communication cables such as an optical cable in the main pipe P and the branch pipe FP, a small hole H2 provided on a user facility side (not shown) of the branch pipe FP enters the branch pipe FP. The cable is inserted to reach the handhole H1.

At the time of passing the cable, a parachute Pa is connected to the end of the cable C for passing the cable as shown in FIG. Then, the cable C is inserted into the branch conduit FP from the end side opened in the small hole H2 with the parachute Pa at the head.

At this time, the end of the main pipe P opposite to the side to which the blower B is connected across the connection portion with the branch conduit FP is closed, and in this state, the blower B is driven. Thus, the inside of the main pipe P and the branch pipe FP are brought into a negative pressure state.

As shown in FIG. 1, the parachute Pa attached to the distal end of the cable C is sucked by the blower B in the direction of the connection with the main pipe P. It is drawn into.

As shown in FIG. 2, when the parachute Pa reaches the connecting portion between the branch pipe FP and the main pipe P and enters the main pipe P, the parachute Pa enters the branch pipe FP. The parachute Pa, which had been widened according to the diameter of the branch pipe FP when it was present, further widened according to the diameter of the main pipe P. At this time, the main pipe P
When the end of the blower B on the side opposite to the connection side is released, the suction amount by the blower B increases and the parasit is reliably expanded.

In addition, the differential pressure generated before and after the parachute Pa in the main pipe P becomes large.
Parachute P which receives negative pressure by suction of blower B
a, the cable C is drawn into the main pipe P from the branch pipe line FP, and the inside of the main pipe P is passed through the handhole H1.
In the direction of. However, at this time, the differential pressure before and after the parachute Pa becomes large, and there is a risk that an excessive tensile force may be applied to the cable. Therefore, the suction force of the blower may be reduced, or the end of the blower B opposite to the connection side may be opened. It is preferable that the area is adjusted to level the force applied to the cable.

As described above, the cable C is passed from the branch conduit FP to the main pipe P, and the end of the passed cable C on the small hole H2 side is connected to a user facility (not shown). Is done.

[Brief description of the drawings]

FIG. 1 is a process explanatory view showing a first example of an embodiment of the present invention.

FIG. 2 is a process explanatory view of the same example.

FIG. 3 is an explanatory diagram showing a connection state of a parachute used in the example.

FIG. 4 is a layout diagram showing a connection state between a main pipe and a branch pipe line.

FIG. 5 is a layout diagram showing a connection state between a main pipe and a branch pipe line.

[Explanation of symbols]

 P… Main pipe FP… Branch pipe H1… Hand hole H2… Small hall B… Blower (suction device) Pa… Parachute (traction tool) C… Cable U… User facility

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Suehiro 3-23-14 Takanawa, Minato-ku, Tokyo Inside Japan Comsys Corporation (72) Inventor Takayoshi Shimura 3-23-14 Takanawa, Minato-ku, Tokyo Nippon COMSYS Corporation (72) Inventor Tsutomu Sato 3-23-14 Takanawa, Minato-ku, Tokyo Nippon COMSYS Corporation (72) Inventor Nobukatsu Ike 1-10-6 Takaban, Meguro-ku, Tokyo Shares Inside the company Hako (72) Inventor Hiroaki Kaneko 1-10-6 Takaban, Meguro-ku, Tokyo Inside the company Hako (72) Inventor Toshio Nakagawa 1-10-6 Takaban, Meguro-ku, Tokyo Hako Co., Ltd. (72) Inventor Junta Sakurai 1-10-6 Takaban, Meguro-ku, Tokyo Inside Hako Co., Ltd. (72) Inventor Takeomi Miura 4-7-120 Toyo, Koto-ku, Tokyo Doi Corporation Work-house F-term (reference) 2H038 CA69 CA73

Claims (3)

[Claims] 1. A method for laying a cable in a main pipe and a branch pipe line having a diameter smaller than the diameter of the main pipe connected to the main pipe, comprising: a tip portion of a cable to be laid; A main body cable is connected to an end of the main pipe on which a cable is laid, and a suction apparatus is connected to an end of the main pipe opposite to a side to which the suction apparatus is connected. By driving the suction device in the state, the tip end of the cable to which the parachute-like traction device is connected is moved from the end of the branch pipe line on the side opposite to the side connected to the main pipe of the parachute-like traction device. The cable passing method, characterized in that the cable is inserted first. 2. When a parachute-like traction tool connected to the end of the cable enters the main pipe from the branch pipe, the end of the main pipe opposite to the side where the suction device is connected is closed. The method of claim 1, wherein the cable is released. 3. The cable line according to claim 1, wherein a suction pressure by the suction device is reduced when a parachute-like traction tool connected to a distal end portion of the cable enters the main pipe from a branch pipe. Construction method.