JPH01160303A - Cable laying method - Google Patents

Abstract

PURPOSE:To lay a cable easily in short time in a conduit having a rising section, by employing a reverse U-shaped bellows tube for inserting the cable through the rising section of the conduit thereby eliminating necessity of opening the conduit in the mid way. CONSTITUTION:When laying work of cable 40 is performed, a jig 30 is first placed on a planar position then the cable 40 is inserted through the jig 30 and secured through a stopper 46 and the like to the jig 30. At this time, a cable pull-in rope 48 and a cable stopping rope 50 are fixed to the cable 40. Then the jig 30 is lifted through a lifter 52 over a conduit 64 and one end of the cable 40 at the side where the rope 48 is fixed is removed and matched with the position of the upper opening of a rising section 64A, thereafter one end of a traction rope 66 is fixed to the end section of the cable 40 and the cable 40 is inserted into the rising section 64A. Under this state, the stopper 46 is removed and the jig 30 is lifted by the lifter 52 with the rope 48 supported by workers, then the cable 40 is moved in the direction of an arrow 68 and into reverse U-shaped bellows tube 32, thereafter the rope 66 is pulled to insert the cable 40 into the conduit 64.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cable laying method, and particularly to a method for laying a cable on an electric line having a rising portion.

[Prior Art] Conventionally, when laying a large cable on a zero-shaped or L-shaped electrical line, as shown in FIG. The cable 12, which had just been cut, was pulled in while being pulled by a towing rope 14 at both ends. In this case, since large cables are difficult to bend, the length of the open middle part is made large, the space between them is constructed with a flexible tube 16, one end of which is removed and the cable 12 is inserted from there, and after the insertion is completed.

The work involved connecting the flexible pipe 16 to the electric line 10. 18 is a pulley, 20 is an overhead crane, 22
is a rope pulling machine.

[Problems to be solved by the invention] The conventional construction method described above requires a lot of manpower and time, and this work often has to be done in a narrow space. The task of inserting it from there was extremely difficult.

The present invention solves the drawbacks of the conventional construction methods described above, and provides a cable laying method that allows even large cables that are difficult to bend to be easily laid in a short period of time on electric lines that accommodate rising parts. purpose.

[Means for Solving the Problems] The cable laying method of the present invention includes the steps of inserting a cable to be laid into a flexible U-shaped bellows pipe, and reversing the flexible bellows pipe through which the cable has been inserted. There are two steps: lifting it in a U shape and positioning it above the rising part of the electric line to be laid;
Align the tip of the cable hanging from one end of the bellows pipe with the opening at the top of the rising part of the electrical line to be laid, feed the cable out of the inverted U-shaped bellows pipe, and use the cable's own weight to enter the rising part of the electrical line to be laid. and inserting it.

[Function] Due to its bellows structure, the U-shaped bellows tube has a small contact area with the cable, and when the cable is sent out from the inverted U-shaped bellows tube, the weight on both sides of the cable suspended on the inverted U-shaped bellows tube is reduced. The balance is lost, and the cable then falls under its own weight and is inserted into the rising part of the cable line to be installed.

[Example] Figures 1 and 2 are a front view and a side view, respectively, showing an example of a U-shaped bellows pipe used in the construction method of the present invention.

The U-shaped bellows tube 32 is made of a flexible plastic material, and has a stopper 34 in order to form the bellows tube 32 into a U-shape and to withstand the weight of the cable to be lifted.
The jig 30 is configured by being integrated with a steel frame 36 via.

Frame 3 has a planar triangular shape, and its vertex 38
The entire jig 30 can be lifted up. The inner diameter of the bellows tube 32 is set to a size that allows the cable to be inserted easily, and the bending radius is also set larger than the allowable bending radius of the cable.

Next, the construction method of the present invention will be explained based on FIGS. 3 to 6.

First, as shown in FIG. 3, the jig 30 is placed horizontally on a flat place such as on the floor, and the cable 40 is inserted through the jig 30 by one person. Figure 3 shows the cable 4 from the cable drum 42.
0 is pulled out and inserted into the jig 30 using the wire extension rollers 44, but the work is easier if the cable 40 is cut to a predetermined length in advance.

After passing the cable 40 through, as shown in FIG. 4, the cable 40 extending from both sides of the jig 30 is rolled up inward and fixed to the jig 30 with a stopper 46 or the like. This is to prevent the hanging cable 40 from getting caught in an unexpected place and causing an accident when the cable 40 is lifted and moved by a lifting machine. Also, at this time, one cable 40
cable pull-in rope 48 to the other cable 40
The cable retaining rope 50 is tied to the cable, and the preparation for lifting is now complete. 5 and 6 are diagrams showing how the cable 40 is inserted into the electric line 64 between the generator 60 and its operation panel 62. As shown in FIG. The jig 30 equipped with is lifted onto the electric line 64 using the lifting force Ia52, one end of the cable 40 on the side to which the cable pull-in rope 48 is tied is removed, and aligned with the upper end opening of the rising part 64A of the electric line 64, One end of the traction rope 66, which has been inserted into the electric line 64 in advance, is tied to the end of the cable 40. Then, while lowering the lifting machine 52, the cable 40 is inserted into the rising portion 64A of the electric line 64.

In this state, the stopper 46 of the cable 40 on the other side may be removed to allow the cable 40 to hang down, and the cable 40 may be further inserted into the electrical line 64 using the cable pull-in rope 48 or the traction rope 66; After hanging the cable 40 on the other side, as shown in FIG. 6, when the jig 30 is gently raised by the lifting machine 52 while the worker is holding the cable pulling rope 48, the cable 40 is 68 in the inverted U-shaped bellows tube 32.

At this time, pull the cable retaining rope 50 to prevent the cable 40 from slipping too much. When the jig 30 is lowered again after raising the cable 40 to an appropriate position, the cable 40 will enter the electric line 64 under its own weight. Once the weight balance on both sides of the cable 40 suspended on the shaped bellows tube 32 is lost, the cable 40 will then slide inside the inverted U-shaped bellows tube 32 under its own weight. If there is resistance to insertion, the above-mentioned vertical movement operation is reversed. By this operation, it is possible to insert the cable 40 to a considerable length of the electric line 64, and the rest can be pulled by pulling the towing rope 66 and moving the cable 40 to the other side of the electric line 64. The cable 40 is inserted to the end.The cable 40 is also inserted when pulling the tow rope 66.
Since its own weight acts on it, the traction force is small.

In the construction method of the above embodiment, the cable 40 is inserted into the electric line 64 by vertically moving the jig 30, that is, the inverted U-shaped bellows tube 32, but the vertical movement of the inverted U-shaped bellows tube 32 is not necessarily necessary. Moreover, although the case of large cables has been explained as an example, it can also be applied to the case of bundling and laying thin cables.

[Effects of the invention] As explained above, the cable laying method according to the present invention has the following effects:
Using an inverted U-shaped bellows tube, the cable is inserted into the rising part of the power line using its own weight, so there is no need to open the middle of the power line, and even large cables that are difficult to bend can be inserted. The handling becomes easy, and the cable can be easily laid in a short time on the electric line that accommodates the rising portion.

[Brief explanation of the drawing]

Figures 1 and 2 are a front view and a side view, respectively, of an embodiment of a U-shaped bellows pipe used in the construction method of the present invention;
I! Figures J and 4 are a perspective view and a plan view, respectively, to explain how to use the bellows pipe, Figures 5 and 6 are a side view of the device, and Figure 7 is a side view of the device to explain an embodiment of the construction method of the present invention. FIG. 2 is a side view of a device for explaining a conventional construction method. 32...Inverted U-shaped bellows pipe 40...Cable 64...-Electric line 64A-...Rising part of electric line Applicant Hitachi Plant Construction Co., Ltd. Figure 3 40 - Group Figure 4 Figure 5 64 +++ is the thread route 64A-11 electric thread Σ name, 0 rising pain β Fig. 7

Claims (1)

[Claims] (1) A method of laying a cable on the rising edge of a power line, which includes the steps of inserting the cable to be laid into a flexible U-shaped bellows pipe, and reversing the flexible bellows pipe through which the cable has been inserted. The step of lifting it in a U shape and positioning it above the rising part of the electric line to be laid, and aligning the tip of the cable hanging from one end of the inverted U-shaped bellows pipe with the opening at the top of the rising part of the electric line to be laid, and lifting it in an inverted U shape. A cable laying method comprising the steps of sending out a cable from a bellows-shaped pipe and inserting the cable into the rising part of the electric line to be laid by using the cable's own weight.