JP2001346310A - Cable drawing tool for use in cable installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable drawing tool which is capable of producing sufficient drawing force by negative pressure, allows frictional force produced between a cable and the inner wall faces of a conduit line to be reduced so as to smoothly draw the cable, and flexibly copes with any variation in diameter of and any bend in a conduit in a cable installation method wherein cables are installed by pulling the cables into conduit lines through utilization of negative pressure. SOLUTION: The cable drawing tool produces drawing force under negative pressure produced in a conduit line when a cable is installed in the conduit line, thereby pulling the cable into the conduit line. The cable drawing tool is provided with a parachute 11 that is joined with the lead end of the cable C and houses an open-cell pig 12 therein. The parachute 11 is made of an air- permeable material and its central portion for housing the open-cell pig 12 has a resin-coated portion 11A without air permeability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable pulling device for pulling a cable into an existing pipeline when laying various cables such as an optical cable in the 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. 5 shows a cable laying method proposed by the applicant of the present invention for laying 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. As a result, the cable C is pulled, and the cable C is drawn into the existing pipeline 1.

A pig 4 used in this cable laying method
There are two types: one molded from a single-cell resin (including a flexible resin) (hereinafter referred to as a single-cell pig) and one molded from an open-cell resin such as urethane (hereinafter referred to as an open-cell pig). There is.

When a single-cell pig is used in the above cable laying method, the single-pig pig does not have air permeability, so that the negative pressure generated in the existing pipeline 1 by suction by the vacuum device 3 is well received. Has the advantage of being able to generate a large traction force, but when traveling in the pipeline, the diameter of the single-bubble pig becomes larger due to the pressure difference before and after this single-pig pig. The friction between the inner wall of the pipeline and the inner wall of the pipeline increases, and it is adaptable to cases where the inner diameter of the pipeline changes or where the pipeline is curved. In addition, there is a problem that it is clogged at the entrance of the pipeline.

On the other hand, the open-cell pig has flexibility compared to the closed-cell pig, and has a small friction between the pig and the inner wall surface of the pipe when traveling in the pipe. Flexible insertion is possible even when the inner diameter of the passage changes or when the conduit is curved, and it has excellent penetrability such that there is little risk of clogging at the entrance of the conduit. .

However, the open-celled pig has a problem that it has air permeability and a large pressure loss, and cannot generate a traction force as much as a single-celled pig.

The open-cell pig is usually connected to the cable C by housing the open-cell pig 4 'in a parachute 5 fastened to the distal end of the cable C, as shown in FIG.

In this case, if the parachute 5 is made of, for example, a waterproof cloth made of vinyl or the like to block the air permeability of the open-cell pig 4 'to prevent a decrease in tractive force, the parachute 5 must be When the hem 5 'is pulled in the cable insertion direction by the negative pressure of the pipeline, it adheres to the inner wall surface of the pipeline and generates a large frictional force with the inner wall surface of the pipeline. And cable C on the contrary
The problem arises that the traction force is weakened.

The present invention has been made to solve the above-mentioned problems in the cable laying method. That is, in the cable laying method of laying by drawing a cable into a pipeline using negative pressure, the present invention can generate a sufficient traction force by a negative pressure, and a gap between the inner wall surface of the pipeline and the cable laying method. The resulting frictional force is small and the cable can be pulled smoothly,
It is an object of the present invention to provide a cable traction tool that can flexibly cope with a change in a pipe diameter or a curve.

[0013]

According to the first aspect of the present invention, there is provided a cable pulling tool in a cable laying method for reducing a negative pressure generated in a pipe when the cable is laid in the pipe in order to achieve the above object. A cable pulling device that draws a cable into a pipeline by receiving and generating a pulling force, and includes a parachute member that is connected to a distal end of the cable and accommodates a pig inside, and the parachute member has air permeability. And a non-breathable portion having no breathability is formed in a central portion of the pigtail for accommodating the pig.

The cable traction tool in the cable laying method according to the first invention is inserted from one end thereof into a conduit for laying the cable, while being connected to the end of the cable.

When the inside of the pipeline is made negative pressure by the vacuum device attached to the other end of the pipeline, the suction force pulls the parachute member and the pig in the pipeline in the downstream direction. The cable is drawn into the pipeline by its traction force.

At this time, since the cable pulling device receives the negative pressure from the vacuum device by the non-ventilated portion of the parachute member, even if the pig housed in the parachute has air permeability. This prevents the traction of the cable from being reduced.

The outer edge portion of the non-ventilated portion of the parachute member comes into sliding contact with the inner wall surface of the pipe when the cable pulling device is pulled in the downstream direction by the negative pressure in the pipe. Since the part has breathability,
The coefficient of friction between the inner wall surface of the pipeline and the inner wall does not increase, and there is no fear that a frictional force enough to reduce the traction force of the cable is generated.

Thus, the cable can be drawn into the pipeline by a large traction force,
The use of open-cell pigs made of soft open-cell resin makes it possible to respond flexibly to changes in pipe diameters and curved sections, and parachute negative pressure generated in pipes. Since it is mainly received by the non-ventilated part of the member, the diameter of the pig can be made smaller than that of the conventional one, so that it can respond more flexibly to changes in the pipe diameter and curved parts, etc. It is possible to prevent clogging at the entrance or the like.

The cable traction tool in the cable laying method according to the second invention has the following features.
In addition to the configuration of the invention described in the above, the non-ventilated portion of the parachute member is formed by performing resin coating on a material having air permeability.

According to the cable traction tool in the cable laying method according to the second invention, the non-ventilated portion can be easily formed in an arbitrary shape at the center of the parachute member.

According to a third aspect of the present invention, there is provided a cable traction tool in a cable laying method, wherein
In addition to the configuration of the invention, the non-ventilated portion of the parachute member is formed by attaching a sheet of a non-breathable material on a breathable material.

According to the cable traction device in the cable laying method according to the third invention, a non-ventilated portion can be easily formed in an arbitrary shape in the center of the parachute member by attaching a vinyl sheet or the like. Can be done.

A cable traction tool in a cable laying method according to a fourth aspect of the present invention provides a cable traction tool according to the first aspect of the present invention.
In addition to the configuration of the invention described in the above, the pig is characterized by being formed of an open-celled material.

According to the cable pulling tool in the cable laying method according to the fourth invention, the cable can be pulled flexibly in response to a change in the pipe diameter or a curved portion.

In order to achieve the above object, the cable traction tool in the cable laying method according to the fifth invention generates a traction force by receiving a negative pressure generated in the pipe when laying the cable in the pipe. A cable pulling device for pulling a cable into a pipeline by a parachute member connected to a distal end portion of the cable, the parachute member being made of a material having air permeability, A non-breathable member having no breathability is accommodated in the inside.

The cable pulling tool in the cable laying method according to the fifth aspect of the present invention is inserted from one end thereof into a conduit for laying the cable, while being connected to the end of the cable.

At this time, a non-breathable member made by, for example, rolling a vinyl sheet or the like into a ball shape is accommodated inside the parachute member.

When the pressure in the pipeline is reduced by a vacuum device attached to the other end of the pipeline, the suction force pulls the parachute member in the pipeline in the downstream direction. The cable is drawn into the pipeline by the traction force.

At this time, since the cable pulling device receives the negative pressure from the vacuum device by the non-ventilating member accommodated in the parachute member, the tractive force of the cable is reduced even if the parachute member has air permeability. Is prevented.

The outer edge of the parachute member is
When the cable puller is pulled in the downstream direction by the negative pressure in the pipe, it comes into sliding contact with the inner wall surface of the pipe, but this outer edge portion that is not in contact with the non-breathable member retains air permeability. Therefore, the coefficient of friction between the inner wall surface of the pipeline and the inner wall surface does not increase, and there is no possibility of generating a frictional force enough to reduce the traction force of the cable.

Thus, the cable can be drawn into the pipe by a large pulling force, and it can flexibly cope with a change in the pipe diameter or a curved portion. Can be prevented.

In the cable laying method according to the sixth aspect of the present invention, the cable traction tool is provided with a fifth structure.
In addition to the configuration of the present invention, the non-ventilating member is characterized in that a non-venting sheet material is rolled up, so that a flexible non-venting member can be easily prepared. become able to do.

The cable pulling tool in the cable laying method according to the sixth invention is a cable pulling tool for achieving the above object.
In addition to the constitution of the invention, the non-breathable sheet material is a vinyl sheet material, whereby sufficient non-breathability of the non-breathable member can be secured.

[0034]

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

FIGS. 1 and 2 show an example of an embodiment of a cable traction tool according to the present invention. The cable traction tool 10 in this example is of a type in which the open-cell pig is accommodated in a parachute and connected to a cable, as in FIG. 6, and FIG. FIG.

In the parachute 11, the central portion of a circular cloth having air permeability is coated with a resin, and the air permeability of the circular resin coating section 11A is cut off. The outer part 11B of the is secured for its air permeability.

The diameter r of the resin coating 11A is
As shown in FIG. 2, the open-cell foam pig 12 is
1, the open-cell foam pig 12 is fitted with a resin coating portion 11A in accordance with the diameter of the open-cell foam pig 12.
The size is set to fit inside.

The parachute 11 is connected to the distal end of the cable C by a pull cord 11C fastened at equal angular intervals on the outer edge.

As shown in FIG. 3, this cable pulling tool 10 is inserted into the existing pipeline 1 from one end (right end in the figure) while being connected to the distal end of the cable C.

When the inside of the existing pipeline 1 is made to have a negative pressure by a vacuum device (not shown) attached to the other end (the left end side in the figure) of the existing pipeline 1, the cable puller 10 is pulled by the suction force. The downstream direction in the existing pipeline 1 (Fig. 3
At the left side), the cable C is drawn into the existing pipeline 1 by the traction force.

At this time, the cable pulling device 10 receives the negative pressure from the vacuum device by the resin coating portion 11A of the parachute 11 having no air permeability.
Open-cell pig 12 contained in this parachute 11
Even if (see FIG. 2) has air permeability, the traction force of the cable C does not decrease.

The outer part 11 of the parachute 11
B, when the cable pulling device 10 pulls the cable C by the negative pressure generated by the vacuum device,
The outer portion 11B is slidably in contact with the inner wall surface of the existing pipeline 1. However, since the outer portion 11B has sufficient air permeability, the friction between the outer portion 11B and the inner wall surface of the existing pipeline 1 does not increase.
There is no possibility of generating a frictional force enough to reduce the traction force of the vehicle.

Thus, the cable C can be drawn into the existing pipeline 1 by a large traction force, and the change in the pipe diameter can be achieved by using the open-cell pig 12 formed of a soft open-cell resin. And the curved portion can be flexibly handled, and the negative pressure generated in the existing pipeline 1 is mainly received by the resin coating portion 11A of the parachute 11 so that the diameter of the open-cell pig 12 is reduced. It can be made smaller than those, so that it is possible to flexibly cope with a change in the pipe diameter or a curved portion, and the likelihood of clogging at the pipe inlet or the like is almost eliminated.

In the above example, the central portion of the parachute is coated with a resin to block the air permeability of that portion. However, by attaching a circular vinyl sheet to the central portion of the parachute, You may make it block the air permeability of the part.

FIG. 4 is a side sectional view showing another example of the cable traction tool according to the present invention.

In the cable pulling device 20 in this example, the entire parachute 21 is formed of a circular material having air permeability. And this cable traction tool 20
Is used in a state in which a non-breathable material 22 formed of a non-breathable material such as a vinyl sheet is accommodated inside a parachute 21 as shown in the figure.

This cable pulling device 20 is also shown in FIGS.
As in the case of the cable pulling tool 10 of the example, the cable C is used by being inserted into the existing pipeline while being connected to the distal end of the cable C.
Is formed in the central portion of the cable, the traction of the cable C is secured, and the friction between the parachute 21 and the inner wall surface of the existing pipeline is reduced because the parachute 21 has air permeability. . Further, the non-aerated material 22 performs the same function as the open-cell pig 12 in FIG.

[Brief description of the drawings]

FIG. 1 is a front view showing a parachute in an example of an embodiment of the present invention.

FIG. 2 is a side sectional view of the cable traction tool in the same example.

FIG. 3 is an explanatory diagram showing a state where a cable is being pulled by a cable pulling tool in the example.

FIG. 4 is a side sectional view showing a cable traction tool according to another example of the embodiment of the present invention.

FIG. 5 is an explanatory view of a cable laying method.

FIG. 6 is a side view showing a conventional cable traction tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Existing pipe line (Pipe line) 10 ... Cable traction tool 11 ... Parachute (parachute member) 11A ... Resin coating part (non-venting part) 11B ... Outside part 11C ... Traction cord 12 ... Open cell pig (pig) 20 ... Cable Towing tool 21 ... parachute (parachute member) 22 ... non-ventilated material (non-ventilated member)

 ──────────────────────────────────────────────────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) 5G369 AA19 BA04 EA03

Claims (7)

[Claims] A cable pulling device 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, the cable pulling device comprising: A parachute member connected to the distal end for accommodating the pig therein, the parachute member being made of a material having air permeability, and a non-ventilating non-air-permeable portion in the central portion for accommodating the pig; A cable traction tool in a cable laying method, wherein a portion is formed. 2. The cable pulling tool according to claim 1, wherein the non-ventilated portion of the parachute member is formed by applying a resin coating on a material having air permeability. 3. The cable in the cable laying method according to claim 1, wherein the non-ventilated portion of the parachute member is formed by attaching a sheet made of a non-breathable material on a breathable material. Towing equipment. 4. The cable traction tool according to claim 1, wherein the pig is formed of a foamed material. 5. A cable pulling device for pulling a cable into a pipeline by generating a traction force by receiving a negative pressure generated in the pipeline when laying the cable in the pipeline, wherein the cable pulls the cable. A parachute member connected to the distal end portion, wherein the parachute member is made of a material having air permeability, and a non-ventilating member having no air permeability is accommodated inside the parachute member. Cable traction tool in the cable laying method. 6. The cable traction tool according to claim 5, wherein the non-breathable member is formed by rolling a non-breathable sheet material. 7. The cable traction tool according to claim 6, wherein the non-breathable sheet material is a vinyl sheet material.