JP2001327023A - Traction implement for laying of cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traction implement for the laying of a cable, by which the cable can pulled surely, even when a conduit line in which the cable is laid is curved when a traction wire is connected to the traction implement connected to the tip part of the cable in order to receive negative pressure, so as to pull the cable in a cable-laying construction method, in which the cable is pulled into the conduit line so as to be laid by using negative pressure. SOLUTION: In the traction implement for the laying of the cable, the negative pressure which is generated inside an existing conduit line 1 is received, and when the cable C is laid inside the existing conduit line 1, a traction force is generated, and the cable C is pulled into the existing conduit line 1. The traction implement is provided with guide pigs 12, which are connected to both ends of a traction pig 11 whose outside diameter is slightly smaller than or nearly identical to the diameter of the existing conduit line 1, and which receives negative pressure to generate the traction force. The tip of the cable C is connected to the guide pig 12 on one side, and a traction wire 5 is connected to the guide pig 12 on the other side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pig which is connected to the end of various cables such as an optical cable for laying the cable in an existing pipeline.

[0002]

In recent years, most communication cables such as optical cables and other various cables are inserted and laid in pipelines buried underground. For example, communication cables such as optical cables are It is laid by being inserted into the existing information box pipeline buried underground.

FIG. 4 shows a cable laying method proposed by the applicant of the present invention to lay a cable in the existing pipeline.

In this cable laying method, FIG.
A delivery device 2 for sending out the cable C at a predetermined speed while holding the cable C is attached to one end of the existing pipeline 1, and a vacuum device 3 is attached to the other end of the existing pipeline 1. The cable C, to which the pig 4 formed of an elastic material is connected at the distal end, is sent out into the existing pipeline 1 by the sending device 2 while the air is sucked, so that the cable C is inserted into the existing pipeline 1. It is something that will be done.

[0005] According to this cable laying method, when the cable C is inserted into the existing pipeline 1 by the delivery device 2, the existing pipeline 1 is sucked by the vacuum device 3.
An airflow along the insertion direction is generated in the inside, whereby friction between the cable C and the pipe wall of the existing pipeline 1 is reduced, and when the inside of the existing pipeline 1 becomes a negative pressure, the pig 4 moves in the insertion direction. The cable C is pulled by pulling the cable C, and the cable C is pulled into the existing pipeline 1, whereby the cable C is laid.

[0006] In recent years, the cable laying work has tended to extend the laying distance in a single work in order to improve the efficiency of the laying work. In addition, a situation occurs in which the suction force of the vacuum device 3 is insufficient, and the cable C cannot be sufficiently drawn into the existing pipeline 1.

Therefore, as shown in FIG. 5, the pulling wire 5 is connected to the pig 4 from the other end side of the existing pipeline 1 to which the vacuum device 3 is attached, and the cable C is connected.
Is proposed to compensate for the lack of suction force by the vacuum device 3 by pulling the cable C, and to extend the laying distance of the cable C in one construction.

[0008] However, the following new problems arise when the traction is performed by the traction wire.

In other words, as shown in FIG. 6, when the existing pipeline 1 is curved, when the distal end of the cable C passes through the curved portion of the existing pipeline 1, the pig 4 pulls the pulling wire. 5, the pig 4 is pulled in a direction to be pressed against the inner wall surface located inside the curved portion of the existing pipeline 1, so that the pig 4 is formed of a soft material such as an open-cell foam material. It will be in the state crushed in the direction.

For this reason, a gap is formed between the pig 4 and the inner wall surface of the existing pipeline 1, and the pressure difference before and after the pig 4 is reduced, the traction force is reduced, and the cable C can be drawn. There is a possibility that a situation such as disappearance may occur.

[0011] The above situation is a case where a parachute 6 is connected to the end of the cable C instead of the pig 4 as shown in FIG. 7 and the cable C is pulled by the parachute 6. The same is true for

That is, even when the pulling wire 5 is further connected to the parachute 6 to be pulled in order to extend the cable laying distance in one installation, FIG.
As shown in the figure, the parachute 6 is folded by the pulling force of the pulling wire 5 inward of the existing pipeline 1 in the curved portion of the existing pipeline 1, and the pulling force of the cable C by the parachute 6 disappears. There is a possibility that it will end up.

The present invention has been made to solve the above-mentioned problems in the cable laying method. That is, the present invention relates to a cable laying method for laying a cable by drawing a cable into a pipeline using a negative pressure, and further connects a pulling wire to a pulling tool connected to receive a negative pressure at a distal end of the cable. It is an object of the present invention to provide a cable laying traction tool that can reliably perform cable traction even when a conduit for laying a cable is curved when traction is performed.

[0014]

According to a first aspect of the present invention, there is provided a cable laying traction tool which receives a negative pressure generated in a pipe when the cable is laid in the pipe. A cable laying pulling device that pulls a cable into a pipeline by generating a traction force, and has a slightly smaller or substantially the same outer diameter as the diameter of the pipeline in which the cable is laid. It is equipped with guide pigs connected to both sides of a traction member that generates a traction force by receiving pressure, a tip end of a cable is connected to one side of the guide pig, and a traction wire is connected to the other side of the guide pig. And

According to the first aspect of the present invention, there is provided a cable laying traction tool in which guide pigs are connected in series before and after a traction member such as a pig or a parachute which generates a traction force by receiving a negative pressure in a pipeline. A guide pig side connected to one side of the member is used by being inserted into a pipeline while being connected to a tip end of a cable to be laid and the other guide pig side being connected to a pulling wire inserted into the pipeline. The cable is drawn into the existing pipeline by the traction force caused by the differential pressure generated before and after the traction member and the traction force by the traction wire when the inside of the pipeline is set to the negative pressure.

When the cable laying pulling tool passes through the curved portion of the pipeline, the component of the pulling force of the pulling wire acting inward in the radius of curvature of the curved portion of the pipeline is used. A guide pig connected to the front side of the traction member receives the force, and among the tensile forces acting on the cable laying pulling device by pulling the cable, a component force acting inward in the radius of curvature direction of the curved portion of the pipeline is used. Since the guide pig connected to the rear side of the traction member receives, even if the traction member is a soft pig or a parachute, it is prevented from being crushed by being pressed inward in the curved portion of the pipeline. .

Therefore, according to the first aspect of the present invention, it is possible to prevent a gap from being formed between the traction member and the inner wall surface of the conduit even in the curved portion of the conduit, and thus the conduit has the curved portion. Even in this case, the cable can be reliably drawn.

The cable laying traction tool according to the second invention is characterized in that the traction member is a pig made of a soft material, and the pig generates a traction force due to a negative pressure in the pipeline. The guide pigs connected before and after the pig prevent the pig that generates the traction force from being crushed when passing through the curved portion of the pipeline and generating a gap between the pig and the inner wall surface of the pipeline.

The cable laying traction tool according to the third invention is characterized in that a space member for maintaining a predetermined distance between the traction member and the guide pig is interposed between the traction member and each guide pig. The space member ensures a space between the guide pig and the guide member required for guiding the traction member.

In a fourth aspect of the present invention, the pulling member is a parachute member. The parachute member generates a tractive force due to a negative pressure in the pipeline, and the parachute member. The guide pigs connected in front and behind prevent the parachute member, which generates the traction force, from being crushed when passing through the curved portion of the pipeline and generating a gap between the parachute member and the inner wall surface of the pipeline.

According to a fifth aspect of the present invention, the guide pig is a pig formed of a hard material, whereby the pulling member is connected to the pulling wire at the curved portion of the pipeline. It is prevented from being crushed by the tensile force from the cable.

A sixth aspect of the present invention is the cable laying traction tool, wherein the material constituting the guide pig is polyethylene, whereby a hard guide pig is formed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an example of an embodiment of a cable laying pig according to the present invention.

In this example, the cable laying traction tool 10 is used.
Is provided with a traction pig 11 formed into a spherical shape having an outer diameter larger than the diameter of an existing pipeline in which a cable is laid by an open cell material, and a pair of guide pigs 12 connected before and after the traction pig 11, respectively. ing.

The guide pig 12 is a polyethylene sphere having an outer diameter slightly smaller than or substantially the same as the diameter of the existing pipeline in which the cable is laid. They are connected in series.

That is, the towing pig 11 is formed with a through hole 11A passing through the center thereof, and the guide pig 12 is formed with a through hole 12A passing through the center thereof, and the wire 13 is connected to the through hole 11A of the towing pig 11. Guide pig 12
Of the traction pig 11
A pair of guide pigs 12 are connected before and after.

Then, each guide pig 12 and towing pig 11
, A spacer 14 is interposed by inserting the center of the spacer 14 through the wire 13, and the traction pig 11 and each guide pig 1 are inserted by the spacer 14.
2 are held apart from each other by a required distance.

At both ends of the wire 13, connecting portions 13A for connecting the cable laying tool 10 to a cable for laying the cable and a towing wire for pulling the cable, respectively, as described later. Is provided.

The cable laying pulling device 10 lays a cable in a state where one connecting portion 13A of the wire 13 is connected to the tip of the cable to be laid and the other connecting portion 13A is connected to the traction wire. To be inserted into the existing pipeline.

Then, similarly to the case of FIG. 5, the tension in the cable laying traction tool 10 is reduced by making the pressure in the existing pipeline negative.
Traction force due to the differential pressure generated before and after the traction pig 11
The cable is drawn into the existing pipeline by the pulling by the pulling wire 5.

As shown in FIG. 2, when the cable laying pulling tool 10 passes through the curved portion of the existing pipeline 1, the pulling force of the pulling wire 5 includes the bending portion of the existing pipeline 1. Pig that pulls a component force acting inward in the radius direction of curvature
1 is received by a guide pig 12 connected to the front side of the cable 1, and the cable C is pulled by the cable C.
Since the guide pig 12 connected to the rear side of the towing pig 11 receives a component force acting inward in the radius of curvature of the curved portion of the existing pipeline 1 among the tensile forces acting on the zero, the towing pig 11 It is prevented from being crushed by being pressed inward of the curved portion of the existing pipeline 1.

Therefore, it is possible to prevent a gap from being formed between the towing pig 11 and the inner wall surface of the existing pipeline 1 even in the curved portion of the existing pipeline 1. The use of the cable laying pulling tool 10 makes it possible to reliably pull in the cable.

Note that, as shown in FIG.
Guide pig 12 before and after parachute 21 instead of 1
Also, when the cable C is pulled into the existing pipeline 1 using the cable laying pulling tool 20 to which the cable C is connected, when the distal end of the cable C passes through the curved portion of the existing pipeline 1,
The guide pigs 12 connected before and after the parachute 21 prevent the parachute 21 from being folded and losing the pulling force of the cable C.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of use in a curved portion of the pipeline of the same example.

FIG. 3 is an explanatory view showing a use state in a curved portion of a pipe in another example of the embodiment of the present invention.

FIG. 4 is a side sectional view showing a conventional cable laying method.

FIG. 5 is an explanatory diagram when a pulling wire is used in the cable laying method.

FIG. 6 is an explanatory diagram showing a state of pulling by a pulling wire at a curved portion of a pipeline in the cable laying method.

FIG. 7 is an explanatory diagram of a case where a cable is pulled by a parachute in the cable laying method.

FIG. 8 is an explanatory diagram showing a state where the parachute shown in FIG. 7 is pulled by a pulling wire in a curved portion of a pipeline.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Existing pipe line (Pipe line) 10 ... Pulling tool for cable laying 11 ... Pulling pig (pulling member) 12 ... Guide pig 13 ... Wire 13A ... Connecting part 14 ... Spacer (space member) 20 ... Pulling tool for cable laying 21 ... Parachute (parachute member, traction member)

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 Japan COMSYS Within Co., Ltd. (72) Inventor Tsutomu Sato 3-23-14 Takanawa, Minato-ku, Tokyo Within Nippon Comsys Co., Ltd. (72) Nobukatsu Ike 1-10-6 Takaban, Meguro-ku, Tokyo Hakko Corporation (72) Inventor Hiroaki Kaneko 1-10-6 Takaban, Meguro-ku, Tokyo Inside Hako Co., Ltd. (72) Inventor Toshio Nakagawa 1-10-6 Takaban, Meguro-ku, Tokyo Inside Hako Co., Ltd. (72 ) Inventor Junta Sakurai 1-10-6 Takaban, Meguro-ku, Tokyo Inside Hako Co., Ltd. 2H038 CA68 CA69 CA73

Claims (6)

[Claims] Claims: 1. A cable laying traction tool for drawing a cable into a pipeline by generating a traction force by receiving a negative pressure generated in the pipeline when the cable is laid in the pipeline, A guide pig which has a slightly smaller or substantially the same outer diameter as the diameter of the pipeline in which the cable is laid and which is connected to both sides of a traction member which generates a traction force by receiving a negative pressure, is provided on one side. A cable tip is connected to the guide pig and a pulling wire is connected to the guide pig on the other side. 2. The traction tool for laying a cable according to claim 1, wherein the traction member is a pig having a soft material. 3. Between the traction member and each guide pig,
3. The cable laying traction tool according to claim 2, further comprising a space member for maintaining a predetermined distance between the traction member and the guide pig. 4. The cable laying traction tool according to claim 1, wherein the traction member is a parachute member. 5. The cable laying traction tool according to claim 1, wherein the guide pig is a pig formed of a hard material. 6. The cable laying traction tool according to claim 5, wherein the material forming the guide pig is polyethylene.