JPH0792362A - Method for installing optical cable - Google Patents

Abstract

PURPOSE:To control a traction machine by automatically discriminating an optical cable part from a traction rope part in the case of installing an optical cable inside a conduit line. CONSTITUTION:The traction rope 3 is connected to the leading edge of the optical cable 1 through a connecting instrument 2, and the traction rope 3 is pulled by the traction machine 4. The connecting instrument 2 has an indentifier 5 made of a magnetic metal material. A magnetic sensor 6 detecting the indentifier 5 is provided on this side of the traction machine 4, and the magnetic sensor is connected to the controller 7. When a detection signal is inputted from the sensor to the controller 7, the controller controls to operate the traction machine.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art The work of laying an optical cable in an underground conduit is performed by connecting the end of the optical cable to the rear end of the tow rope that has been previously inserted into the conduit and connecting the tow rope to the outside of the end of the conduit. The optical cable is introduced into the pipeline by towing with the provided towing machine, but due to problems with the strength of the optical cable, the part towed by the towing machine is the part of the towing rope or the part of the optical cable. Determining whether or not it is an important factor in proceeding with the construction. Therefore, at present, an operator visually judges the towing machine to determine whether it is a towing rope or an optical cable, and operates the towing machine based on the recognition.

[0003]

As described above, under the present circumstances where an operator must be present at the part of the towing machine to perform visual inspection, the work of laying the optical cable is automated, and the work is efficiently performed by unmanned operation. If you try to proceed to the next step, the construction will be hindered. The present invention, in view of such circumstances,
An object of the present invention is to provide an optical cable laying method capable of automatically laying an optical cable by automatically distinguishing an optical cable portion and a rope portion without relying on visual observation.

[0004]

According to the present invention, in a method for connecting a tow rope to the tip of an optical cable and towing it by a towing machine to lay the optical cable in a conduit,
A method of laying an optical cable, characterized in that an identifier for displaying a tip portion of the optical cable is formed, a sensor for detecting the identifier is provided in front of the towing machine, and the towing machine is controlled by the detection signal. Is provided,
The above object is achieved.

[0005]

Embodiments will be described in detail below with reference to embodiments. Figure 1
The explanatory view of the work of laying an optical cable is shown, and the tow rope (3) is connected to the tip of the optical cable (1) through the connector (2). When the length of the rope is short with respect to the length of a pipeline (not shown) such as an underground pipeline, a plurality of ropes are connected through other connecting tools (2a) ... Usually, the connecting members (2) and (2a) are made of a metal material, but they may be made of a synthetic resin material or the like.

The tow rope (3) is previously inserted into the pipeline by appropriate means, the optical cable (1) to be laid is connected to the rear end thereof, and the towing machine (4) is provided at the front position of the pipeline. Is towed in the direction of the arrow, and the optical cable (1) is introduced into the conduit as it advances.

An appropriate identifier (5) is provided to indicate that it is the tip of the optical cable (1).
As the identifier, various known ones can be used, but when the optical cable is introduced into an underground conduit, it is contaminated with water, mud, or the like, and the connecting tools (2) and (2a) are generally used. Since it is made of a metal material, it is preferable to adopt an appropriate identifier that does not adversely affect these, and various sensors (6) corresponding to the identifier are provided in front of the towing machine (4). There is.

In the embodiment shown in FIG. 1, a magnetic body is used as the identifier (5) and a magnetic sensor such as a reed switch is used as the sensor (6). In the figure, the identifier (5) is provided on the connector (2) by forming a part of the connector (2) immediately before the optical cable (1) with a magnetic metal material. It may be attached to the surface of the tool (2), embedded therein, or the entire connecting tool may be formed of a magnetic metal material. In addition, a flexible magnetic material piece such as a magnetic tape or a rubber magnet is formed, and the magnetic material piece is attached to the outer circumference of the tip of the optical cable (1), the surface of the immediately preceding coupling tool (2), or the rope. It may be attached to the outer periphery of the rear end or the like.

The sensor (6) having the identifier (5) is connected to the control device (7). When the sensor (6) detects the identifier (5), a detection signal is sent to the control device (7). It is input and the operation of the towing machine (4) is controlled. Such an identifier using a magnetic material is particularly effective in a pipeline to which water, mud, etc. adhere, as described above.

FIG. 2 shows another embodiment using an encoder. Generally, when laying an optical cable,
In order to measure the laying distance, a rotary encoder (8) is provided in the towing machine or its accessory, and the towing length can be known from the number of pulses from the rotary encoder (8). Further, in the embodiment shown in the drawing, a tape (10) having a metal body (9) for indicating the tip of the optical cable (1) is attached to the tip of the optical cable as an identifier (5). The length of (9) is formed to be shorter than the length of the connecting tool (2).

When a metal sensor is used as the sensor (6) and is connected to the control device (7) together with the encoder (8), the sensor (6) is based on the number of pulses from the encoder (8) as shown in FIG. It is possible to measure the length of the portion detected in (). That is, as described above, since the connector (2) is generally formed of a metal material, the sensor (6) also detects the part of the connector (2), but the pulse of the detection part (11). Number (Fig. 4
(A)) is larger than the number of pulses (FIG. 4B) of the detection portion (12) of the metal body (9) of the metal tape (10), and in this case, the connector (2) is used. ) Can be determined. If the number of pulses is less than the number of pulses of the connector part, it is determined that the tape is the metal tape (10) and the tip of the optical cable can be identified.

Metal body (9) provided on the tape (10)
Are arranged in a bar code shape in the longitudinal direction as shown in FIG. 3, the sensor (6) intermittently emits a detection signal corresponding to the bar code as shown in FIG. 4 (b).
The difference from the connector part is further clarified, and the reliability of detection can be further improved. It should be noted that such a parcode-like identifier (5) can also be applied to the above-mentioned embodiment in which a magnetic material is used as the identifier, and the magnetic material is provided in the form of a bar code on the tape so that it can be detected by the magnetic sensor. May be.

As the identifier and its sensor, in addition to the above-mentioned embodiment, the identifier is used as a transmitter according to the state of the pipeline,
The sensor may be used as a receiver, or a photoelectric element may be used, and the sensor may be appropriately configured.

[0014]

The present invention is constructed as described above, and a sensor is provided in front of the towing machine to detect the tip of the optical cable connected to the towing rope and control the towing machine based on the detection signal. Therefore, it is not necessary to arrange an operator for visual monitoring in the part of the towing machine as in the conventional case, and the installation work of the optical cable can be automated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of another embodiment of the present invention.

FIG. 3 is a plan view showing an embodiment of an identifier.

FIG. 4 is an explanatory diagram showing pulses by an encoder,
(A) is an explanatory view showing an output waveform of a connector part, (b) is a bar code metal tape part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical cable 2 ... Connecting tool 3 ... Towing rope 4 ... Towing machine 5 ... Identifier 6 ... Sensor 7 ... Control device 8 ... Encoder 9 ... Metal body 10 ... Metal body tape

Claims (6)

[Claims] 1. A method of connecting a tow rope to the tip of an optical cable and towing the cable by a towing machine to lay the optical cable in a conduit, wherein an identifier for indicating the tip of the optical cable is formed, and the identifier is used for the towing. A method for laying an optical cable, characterized by detecting with a sensor provided in front of the machine and controlling the towing machine according to the detection signal. 2. The method of laying an optical cable according to claim 1, wherein the identifier is a magnetic material, and the sensor is a magnetic sensor. 3. The method of laying an optical cable according to claim 2, wherein the magnetic body is provided at a connecting portion between the optical cable and the tow rope. 4. The method for laying an optical cable according to claim 1, wherein the identifier is a metal tape having a metal body having a length shorter than a length of a connecting portion between the optical cable and the tow rope. 5. The method of laying an optical cable according to claim 1, wherein the identifiers are arranged in a bar code shape in the longitudinal direction. 6. The method of laying an optical cable according to claim 1, wherein the identifier is a transmitter and the sensor is a receiver.