JPH0340572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for laying a cable or other elongated body along a cable laying conduit provided underground or along a trough having an open surface.

In general, when long objects such as power and communication cables are drawn along pipes or troughs, the pipes, etc. (hereinafter referred to as pipes) have many bends, or long-distance pipes, etc. (200 to 300 meters or more), due to frictional resistance between the pipe and the long body (hereinafter referred to as the cable),
There is a risk that a tension exceeding the allowable tension will be generated in the cable, causing damage to the cable.

Therefore, as an example of installing long cables, etc., the method shown in Figure 1 (Tokuko Showa
41-18025) has been proposed.

That is, a caterpillar drive device 3 is placed in the manholes 2B, 2C, 2D, etc. located in the middle of the long-distance underground pipe 1, and a pulling device 4 such as a winch is placed near the outlet manhole 2E of the pipe 1. death,
The tip of the cable 6 is connected to the end of the guide rope 5 wound around the pulling machine 4, and the cable 6 is pulled by the drive device 3... and the pulling machine 4, whereby the cable 6 is This method prevents the tension from being concentrated only near the tip.

However, this method has the following drawbacks.

() Since the caterpillar type drive device is a large device, it is difficult to install it inside a narrow manhole.

() If the retracting speed of the caterpillar drive at any one point changes due to continuous (endless) retracting of the cable, excessive tension or slack will occur in the cable. This tension or slack is then maintained until it passes through the last drive without being corrected midway. Furthermore, if speed changes or slips occur between the cables and the caterpillars in multiple caterpillar drive units, tension or slack in the cables will accumulate, making it impossible to control the overall length.

The present invention was made against the background of the above-mentioned circumstances, and
The purpose of this invention is to provide a method for laying a long body that reduces the tension applied to the cable during cable laying work, prevents damage to the cable, and promotes smooth laying work. A plurality of intermittent traction machines 9A, 9B, 9C, etc. are installed between the guide rope 5 and the guide rope 5 pulling means 8, and each of these intermittent traction machines is divided into two groups every other time. The intermittent traction machines 9A, 9C, 9E... and the other group 9B, 9D, 9F... are operated synchronously, and the forward process of each intermittent traction machine in one group and the return process of each intermittent traction machine in the other group are performed. Further, the elongated body is drawn in by substantially matching the timing of the return stroke of each intermittent traction machine of the one group and the forward stroke of each intermittent traction machine of the other group.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 2 explains one embodiment of the present invention, in which a delivery drum (delivery means) 7 around which a cable 6 is wound is installed on the ground near a manhole 2A of a long-distance underground pipe 1. , and a pulling machine (retracting means) 8 for the guide rope 5 is installed on the ground near the exit manhole 2E. This take-up machine 8 is driven by, for example, a torque motor or the like, and is capable of controlling the torque at the time of take-up. Also, the manholes 2B, 2 between the sending drum 7 and the take-up machine 8
C, 2D, 2E with intermittent traction machine 9B, 9C, 9D,
Install 9E. These intermittent traction machines 9B, 9C,
9D and 9E are devices that alternately repeat a forward stroke in which the cable is gripped and pulled with a constant stroke 1 and a backward stroke in which the cable 6 is released from its grip and returned to its original position, as will be described later. Then, the starting end of the guide rope 5 is moved along the pipe line 1 by the intermittent traction machines 9B and 9.
C, 9D, 9E, and then manhole 2
It is pulled out from E to the ground and connected to the above-mentioned take-up machine 8.

On the other hand, the cable 6 is pulled out from the delivery drum 7 and drawn into the manhole 2A via an intermittent traction machine 9A similar to the above-mentioned intermittent traction machines 9B, 9C, 9D, and 9E fixed to a support stand 10 on the ground. Then, the tip of this cable 6 is connected to the terminal end of the guide rope 5.

Here, the intermittent traction machines 9A, 9B, 9C...
In detail, this device is a well-known cable traction machine described in, for example, Fujikura Electric Cable Technical Report No. 62 (Publisher: Fujikura Electric Cable Co., Ltd., Publication date: February 1980), and is shown in Figure 3. As shown, a mounting base 12 is attached to the opening 11 of the conduit 1 in the manhole, a sleeve-shaped grip part 13 that is extendable and retractable, such as a wire net, is connected to the mounting base 12 so as to be movable in the orthogonal direction, and this grip It is provided with a traction drive mechanism 14 such as a hydraulic cylinder that moves the portion 13 forward and backward, and a grip release mechanism 15 such as a hydraulic cylinder that expands and contracts the grip portion 13.

If this operation process is explained with reference to FIGS. 3a to 3d, the cable 6 is inserted into the grip part 13,
As shown in Figure a, the grip part 13 is extended by the grip release mechanism 15 to grip the cable 6, and as shown in Figure 3b, the grip part 13 is advanced by the traction drive mechanism 14 to hold the cable 6. Tow 6. Next, as shown in FIG. 3c, the gripping part 13 is retracted to release the grip on the cable 6, and the gripping part 13 is retreated to its original position as shown in FIG. 3d. The cable 6 is pulled in the forward direction of the grip portion 13 by repeating the above-described steps in sequence.

Further, reference numerals 16 and 17 in the figure indicate a front limit switch and a rear limit switch respectively provided in the traction drive mechanism 14, and these switches 16,
17, the outgoing strokes of a and b, and c and d
and the return stroke are ensured to be sequential operations. Further, the oil pressure of the traction drive mechanism 14 is set in advance to be less than the maximum allowable tension of the cable, so that excessive tension is not applied to the cable.

These intermittent traction machines 9A, 9B, 9C... are divided into two groups every other group, and the intermittent traction machines 9A, 9C, 9E of one group and the intermittent traction machines 9B, 9D of the other group are operated synchronously. , the timings of the forward stroke of one group and the backward stroke of the other group, as well as the backward stroke of one group and the forward stroke of the other group, are made to coincide. Each of these intermittent traction machines 9A, 9B, 9C...
The operation is shown in FIG. 4 in a time chart. However, f indicates the forward stroke and b indicates the backward stroke. That is, the cable 6 is pulled almost continuously by the adjacent intermittent pulling machines alternately. At this time, it is desirable to match the traction speeds of each intermittent traction machine 9A, 9B, 9C, but even if they do not match, the stroke 1 of each intermittent traction machine 9A, 9B, 9C... 14 (determined in accordance with the characteristics of the hydraulic cylinder)), smooth installation work can be performed without accumulating tension or slack on the cable 6. In order to make the intermittent traction machines 9A, 9C, 9E of one group repeat accurate alternating operations with the intermittent traction machines 9B, 9D of the other group, for example, all of the intermittent traction machines of one group (the other group) Unless the limit switch in front of the intermittent traction machine is turned on, the control may be such that any one of the intermittent traction machines in the other group (one group) does not start the forward stroke operation.

When the cable 6 is pulled in this way and its tip reaches the exit manhole 2E, the guide rope 5 and all the intermittent traction machines 9A, 9B,
9C... is removed, and the installation of the cable 6 into the conduit 1 is completed.

Further, FIG. 5 shows an example of application when the conduit 1' is curved, and an intermittent traction machine 9F, 9G, 9H, etc. is provided for each bent part 18, such as a bend, and the bent part 18... There is slack 19 in the cable 6 passing through...
This reduces the frictional resistance that the cable 6 receives, allowing smooth cable installation.

Although Figures 2 and 5 show an example of laying one cable in one conduit, it is also possible to install multiple intermittent traction machines in parallel and lay multiple cables in parallel. Good too.

As explained above, according to the present invention, the following effects can be obtained.

By making the strokes of the forward strokes of each intermittent traction machine approximately equal, and for adjacent intermittent traction machines, the timings of one outgoing stroke and the other backward stroke, as well as one backward stroke and the other forward stroke, were made almost the same. To prevent excessive tension or slack from occurring in the cable and facilitate smooth cable installation work.

Since the cable is alternately and continuously pulled by adjacent intermittent traction machines, the cable can be pulled even during the return stroke of either one of the intermittent traction machines, thereby shortening the installation time.

Since the cable is gripped and towed at multiple locations, the frictional resistance between the conduit and the cable during towing is divided into multiple locations, and the tension generated in the cable can be suppressed, so the conduit is Even if the cable is infinitely long or there are countless bends, the cable can be laid smoothly without being damaged.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional cable installation method;
Fig. 2 is a vertical sectional view illustrating an embodiment of the present invention, Figs. 3 a to d are explanatory diagrams of the operation of the intermittent traction machine used in the present invention, and Fig. 4 is a timing diagram of the operation of each intermittent traction machine. FIG. 5 is a horizontal sectional view showing an example of application of the present invention. 1,1'...Pipe line, 5...Guiding rope, 6...
... Cable (elongated body), 7 ... Delivery drum (delivery means), 8 ... Taking-off machine (taking-up means), 9
A, 9B, 9C, 9D... Intermittent traction machine, l... Stroke.

Claims (1)

[Claims] 1. A plurality of intermittent traction machines 9A,
9B, 9C... are attached, and each of these intermittent traction machines is divided into two groups every other group, and one group of intermittent traction machines 9A, 9C, 9E... and the other group 9B, 9D, 9F... are attached. At the same time, the forward stroke of each intermittent traction machine in one group, the return stroke of each intermittent traction machine in the other group, the return process of each intermittent traction machine in the one group, and the intermittent traction of the other group are performed in synchronization. A method for laying an elongated body, characterized in that the elongated body is pulled in at a timing substantially coinciding with the forward process of a machine.