JPH05328559A - Method for laying cable - Google Patents

Abstract

PURPOSE:To lay a long cable such as an optical cable in a conduit tube automatically, by transmitting the measurement values of the front traction part to the rear traction part via a control line, and by driving the rear traction machine synchronizing with the front traction machine. CONSTITUTION:Control devices 4 for controlling respectively driving devices 3 of respective traction machines 1 are provided, and the control devices 4 of respective traction parts are connected to each other by a control line 6. In each traction part, such traction data as the traction speed of a cable or the moving quantity of the cable are measured, and these data are transmitted from the front traction part to the rear traction part via the control devices 4 and via the control line 6. The rear control device 4 compares the traction data of the rear traction part with the traction data of the front traction part, and so controls the driving device 3 of the rear traction part that both the traction data become equal to each other. Thereby, a long cable can be laid automatically in a conduit tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable laying method for laying a long cable such as an optical cable in a conduit.

[0002]

2. Description of the Related Art When a long cable, such as an optical cable, which has a length of one winding of about 2 km or more, is laid in a pipe line within an allowable tension and a slack amount, it acts on the cable The traction parts are provided at a plurality of points so that the traction force is within the allowable tension, and cable traction machines are distributed and laid in each traction part.

In order to lay an optical cable or the like in a pipeline, a small parachute is usually attached to the tip of a thread such as a tako thread, blown into the pipeline with a compressor, and the thread is inserted into the pipeline. Tie a rope to the thread and pull it out of the conduit.
Then, as shown in FIG. 3, a cable (C) is connected to the rope, and the cable or the like is connected to the towing parts (20),
(21) ... is towed by the towing machines (22) and (22) provided in the pipe (P).

When the rope or cable (C) is towed, excessive tension is applied to the cable or the like, which damages the cable or the like. Therefore, a worker is arranged at each towing portion, and the operator visually confirms the slack (23) so that the operator can operate within the allowable tension of the cable and the allowable amount of slack, and the driving device of the motor (24) of the towing machine. (25) startup,
Stopping work is performed, and a tension detecting device is installed to detect the slack state of the cable, and the start and stop of the towing machine are controlled according to the detected value.

However, in the conventional method, each towing machine (2
Since 2) and (22) are controlled independently, a worker must be placed in each towing section to perform driving operation.
Many workers were needed. When controlling the allowable amount of slack by detecting the tension, the sensor is pressed against the cable for measurement, which causes an increase in the tension on the front towing machine, and when installing a long cable. , You will have to install an extra towing machine. In addition, the operating conditions must be changed each time depending on various factors such as the type of cable, the position of the towing machine in the manhole, the conditions of the laying pipeline, etc. I couldn't decide, and it was a difficult operation.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of workers when laying a long cable or the like by providing a towing portion at a plurality of positions, and the type of cable and other conditions. It is an object of the present invention to provide a cable laying method capable of automatically laying a cable without having to change the setting of the operating condition each time even when the number changes.

[0007]

According to the present invention, a control device for controlling a drive device of a towing machine distributed in a plurality of towing portions is provided, and each control device is connected to the front towing portion by a control line. The cable pulling speed or moving amount in the rear pulling part is measured, and the measured value of the front pulling part is transmitted to the rear pulling part through the control line. A method for laying a cable is provided, which is characterized in that the rear traction unit drive device is controlled so as to be equal to the movement amount, and the rear traction machine is driven in synchronization with the front traction machine. To be achieved.

[0008]

Embodiments will be described in detail below with reference to embodiments. FIG. 1 is a block diagram showing the overall configuration of the cable laying method of the present invention. For example, a towing portion (D1) in which a towing machine (1) for towing a cable (C) such as an optical cable to the left in the figure is arranged between pipe lines (P) ... About 500 m long, (D2), (D3) ... Are provided.

The towing machine (1) has a known structure for holding and pulling the cable (C), and is driven by a motor (2) such as a DC motor or an AC motor to drive the motor (2). ) Is connected to a drive device (3) for supplying power.

A control device (4) for controlling the motor start and motor speed by the drive device (3) is communicated to each drive device, and each control device is communicated for construction through a modem or a transceiver (5). Communication is performed by a communication line or a control line (6) composed of a wireless or wired public line.

A signal from a cable speed detector or a movement amount detector (8) is input to the control device (4). As the movement amount detector, for example, a digital encoder or the like may be used to measure the cable movement amount.

Further, a signal from a slack detector (7) for detecting the amount of cable slack in the cable feeding direction of each towing portion is also input to the control device (4). The slack detector may be of a type in contact with the cable or a non-contact type.

Thus, the control device (4) sends back towing data such as speed data or movement amount data of the cable (C) at each towing portion (D1), (D2), (D3) ... It has a configuration for transmitting to the traction units (D2), (D3) ... Through the modem or the transceiver (5) and the control line (6). Further, the traction data of the front traction sections (D1), (D2) ... Is received, and the traction data such as speed data or movement amount data measured by the traction sections (D2), (D3) is received by each control device. Compared with the above-mentioned towing data, the towing part (D
2) and (D3) are provided with a configuration for outputting a speed command for controlling the motor speed of the motor (2) via the drive unit (3) so that the traction data becomes equal to the front traction data. There is. These configurations may be configured by known appropriate circuits. In this way, when the towing portion (D1) on the front side starts towing, the towing portions (D2), (D3) ... On the rear side sequentially start towing.

As described above, the rear towing machine is driven in synchronism with the front towing machine, but the distance between the towing parts is usually long, and bending or slack of the cable is caused in the middle of the pipeline (P). Therefore, even if the leading towing section starts towing,
At the same time, the pulling action may not be transmitted to the cable at the rear pulling portion. In such a case, when the towing machine is driven simultaneously by the leading towing portion and the trailing portion behind it, slack may occur in the cable feeding direction at the trailing portion.

Therefore, as shown in the figure, when the slack detector (7) provided in a portion where slack occurs in the cable feeding direction detects a slack exceeding the allowable slack amount, the detection signal is sent to the control device (4). The control device (4) stops the driving of the towing machine (1) in the rear towing section. When the amount of slack detected by the slack detector (7) is within the allowable amount of slack, the control device (4) issues a speed command to the drive device (3) and starts towing at the rear towing portion. I am doing it.

In the above embodiment, each control device (4)
Are the respective towing parts (D1), (D2), (D3)
, And the control line (6) is used for direct communication, but it is also possible to make indirect communication. That is, as shown in FIG. 2, a centralized control management device (9) is installed at an appropriate place, and the centralized control management device (9) and the above-mentioned control devices (4) ... Are connected by control lines (6). .
In this way, in the central control management device (9),
The traction data of the whole traction unit (D1), (D2), (D3) ... Is managed, and the drive unit (3) in each traction unit.
Since the whole can be controlled, it is possible to simplify the configuration of the control device (4) installed in each towing portion.

[0017]

Since the present invention is configured as described above, it is not necessary to arrange a worker for each towing section, the number of workers can be reduced, and the towing machines in each towing section are mutually connected. Since it starts and stops in conjunction with each other, it is possible to lay cables, etc. within the allowable tension and the amount of slack, and set the operating conditions depending on the type of cable, the position of the towing machine in the manhole, and the conditions of the laying pipeline The cable can be installed automatically without the need to change the.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of the present invention.

FIG. 2 is a block diagram showing another embodiment.

FIG. 3 is a block diagram showing a conventional cable laying method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Towing machine 2 ... Motor 3 ... Drive device 4 ... Control device 5 ... Modem or transceiver 6 ... Control line 7 ... Slack detector 8 ... Speed detector or movement amount detector 9 ... Centralized control management device

Claims (4)

[Claims] 1. A method for laying a long cable by disposing traction machines in respective traction sections provided at a plurality of positions so that the traction force is within an allowable tension, and a control device for controlling a drive unit of each traction machine. The pulling speed or the amount of movement of the cable in the front and rear towing sections is measured, and the measured value of the front towing section is transmitted to the rear towing section through the control line. Alternatively, the drive unit of the rear traction unit is controlled so that the movement amount becomes equal to the traction speed or movement amount of the front traction unit, and the rear traction machine is driven in synchronization with the front traction machine. How to lay cables. 2. The cable laying method according to claim 1, wherein the control device is provided in each towing portion. 3. The cable laying method according to claim 1, wherein the control device is controlled by a centralized control management device, and each towing section is connected via a control line connecting the control device and the centralized control management device. 4. A cable slack detector is provided in the cable feeding direction of each towing portion, and control is performed so as not to drive the drive device of the towing portion while the slack detector detects a slack state. The cable laying method according to claim 1, wherein: