JP2018085248A - Cable with load detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a cable with load detection function capable of detecting a position where load is applied on a cable.SOLUTION: In a cable with load detection function 100 in which a conductor wire 10 and an optical fiber 20 are twined, by utilizing optical fiber sensing technology by connecting an optical device 50 having a light source for exiting laser light to a core 21 of the optical fiber 20 and a detector for detecting scattered light in a core 21 to one end of the optical fiber 20, positions where the optical fiber 20 is deformed or distorted are detected, and thereby, positions where the load is applied on the cable 100 with load detection function are made possible to detect.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cable with a load detection function that makes it possible to detect a location where a load is applied to the cable using optical fiber sensing technology.

Conventionally, one sensing line provided with an insulator on the outer periphery of a conductor obtained by twisting a plurality of strands, and a plurality of detected lines provided with an insulator on the outer periphery of a conductor obtained by twisting a plurality of strands And a cable with a disconnection detection function having a structure in which the periphery of the detection line is twisted so as to be surrounded by a plurality of detection lines (see, for example, Patent Document 1).
In this cable with disconnection detection function, the wire diameter of the conductor of the detection wire is made larger than the wire diameter of the conductor of the detected wire, or the material of the conductor wire of the detection wire and the conductor wire of the detected wire Insulated wires that are used as the detected wire by making the bending life of the detected wire shorter than that of the detected wire, and by detecting the presence or absence of disconnection by passing a current through the detected wire. The disconnection time is predicted, and the cable with the disconnection detection function is replaced based on the prediction result.

Japanese Patent Laid-Open No. 2006-3260

However, in the case of the cable disclosed in Patent Document 1, although the disconnection timing of the insulated wire (detected line) can be predicted, the disconnection position (disconnection position) cannot be predicted, so the disconnection of the detection line is detected. In such a case, there is a problem that the cable must be inspected over the entire line or the entire cable must be replaced.
On the other hand, if the detection line is disconnected due to a load on the cable, if the location of the load is known, check that part pinpointed, whether the cable needs to be replaced immediately, or whether there is a delay before the replacement, etc. Since it becomes possible to judge and to determine whether it is necessary to partially replace the cable so as to include the disconnection portion of the detection line, it is preferable in performing cable maintenance.

  Moreover, in the case of the cable of the above-mentioned patent document 1, when a disconnection of the detection line is discovered, the insulated wire (detected line) may have already deteriorated. There was a problem of unexpected system failure.

  The objective of this invention is providing the cable with a load detection function which can detect the location where the load acted on the cable.

In order to achieve the above object, the present invention provides:
At least one conductor wire;
A cable with a load detection function comprising: at least one optical fiber along a direction in which the conductor wire extends;
An optical device having a light source that emits laser light to the core of the optical fiber and a detector that detects scattered light in the core is connected to one end of the optical fiber, and the optical fiber is deformed. It was configured to be detectable.

In the case of a cable with a load detection function having such a configuration, the part where the load is applied to the cable with the load detection function is detected by detecting the part where the optical fiber is deformed or distorted by using the optical fiber sensing technology. Can be detected.
And since the location which may have damaged the cable with a load detection function can be specified at an early stage, it can be repaired or replaced before the deterioration of the cable progresses from that location.

Also, preferably
The optical fiber is twisted with the conductor wire.
By doing so, when a load acts on the cable with a load detection function, the load easily acts on the optical fiber, and it becomes easy to detect a location where the load acts on the cable with the load detection function.

Also, preferably
The optical fiber is spirally wound around the conductor wire.
By doing so, when a load acts on the cable with a load detection function, the load easily acts on the optical fiber, and it becomes easy to detect a location where the load acts on the cable with the load detection function.

Also, preferably
The optical fiber and the conductor wire are covered with a sheath.
By doing so, it is possible to prevent the optical fiber from being damaged by simple friction or the like, so that it is possible to suitably detect the location where the load acts on the cable with the load detection function.

  ADVANTAGE OF THE INVENTION According to this invention, the cable with a load detection function which can detect the location where the load acted on the cable is obtained.

It is the perspective view (a) which shows the cable with a load detection function of this embodiment, and its sectional drawing (b). It is explanatory drawing about detecting the location where the load acted on the cable with a load detection function. It is a perspective view which shows the cable with a load detection function from which a cable shape differs.

  Hereinafter, embodiments of a cable with a load detection function according to the present invention will be described in detail with reference to the drawings. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

The cable 100 with a load detection function of the present embodiment includes, for example, two conductor wires 10 and one optical fiber 20 as shown in FIGS. 1 (a) and 1 (b). 10 and the optical fiber 20 are twisted together. A bundle in which the conductor wire 10 and the optical fiber 20 are twisted is covered with a sheath 30 made of an insulating material.
Note that the number of the conductor wires 10 and the optical fibers 20 is not limited thereto, and includes at least one conductor wire 10 and at least one optical fiber 20, and the optical fiber 20 extends in the direction in which the conductor wire 10 extends. As long as

The conductor wire 10 includes a conductor 11 in which a plurality of strands are twisted and an insulating layer 12 that covers the conductor 11.
The two conductor wires 10 may be conductors 11 having the same number of strands or conductors 11 having different numbers of strands. Moreover, even if it is the conductor 11 with the same wire thickness (cross-sectional area), the conductor 11 with different wire thickness (cross-sectional area) may be sufficient.

The optical fiber 20 includes a core 21 having a relatively high refractive index and a clad 22 having a relatively low refractive index.
The clad 22 is formed so as to cover the periphery of the core 21, and a coating film covering the clad 22 may be provided.

Connected to one end of the optical fiber 20 of the cable 100 with load detection function is an optical device 50 having a light source for emitting laser light to the core 21 of the optical fiber 20 and a detector for detecting scattered light in the core 21. (See FIG. 2).
In the present embodiment, an OTDR (optical time domain reflectometer) capable of detecting light reflected by Fresnel in the optical fiber 20 is used as a detector (photodetector), and the load 100 having a load detection function is loaded. The optical fiber 20 is used as a sensor that detects a phenomenon in which the scattered light changes due to the deformation when the optical fiber 20 is deformed (strained). Then, by analyzing the optical signal detected using the optical fiber 20, the location where the load is applied to the cable 100 with load detection function is detected so that the location where the optical fiber 20 is deformed or distorted is detected. Configured to detect.
In addition, since the optical fiber 20 is twisted with the conductor wire 10, when the load acts on the cable 10 with a load detection function, the load is likely to act on the optical fiber 20.

For example, as shown in FIG. 2, when a load such as a strong impact acts on the cable 100 with a load detection function and the optical fiber 20 is deformed or distorted, the optical device 50 reflects the light reflected by Fresnel in the optical fiber 20. To detect.
The distance L from one end of the optical fiber 20 (optical device 50) to the location where the optical fiber 20 is deformed (the location where the load is applied to the cable 100 with the load detection function) is, for example, the propagation speed of laser light. It can be obtained as a value that is ½ of the value obtained by multiplying the time difference between the time of emitting the laser light and the time of receiving the reflected light.
Thus, the distance information regarding the location where the load is applied to the cable 100 with the load detection function and the time information when the Fresnel reflected light is received are associated with each other and stored in a storage device (not shown) and displayed on a display device (not shown). Then, it becomes possible for the user to know when and where the load acts on the cable 100 with the load detection function.

  As described above, if the location where the load is applied to the cable 100 with the load detection function is detected using the optical fiber sensing technology and the user can grasp the position, the cable 100 with the load detection function is damaged. Since it is possible to identify a possible location at an early stage, it is possible to repair or replace the cable before the deterioration of the cable proceeds from that location.

In particular, it is possible to pinpoint a location where a load is applied to the cable 100 with a load detection function and where the load detection function cable 100 may be damaged. Instead, it is possible to perform a partial replacement, thereby reducing repair costs.
In addition, inspect the place where the load is applied to the cable 100 with the load detection function, and if the cable (conductor wire 10) is not damaged, register it as a check required place without performing repair or replacement immediately. The user may check the location periodically to confirm the progress of deterioration. Then, repair or replacement may be performed when repair is necessary.

The present invention is not limited to the above embodiment.
For example, as shown in FIG. 3, the present invention may be applied to a leaky coaxial cable.
A cable 200 with a load detection function in which the present invention is applied to a leaky coaxial cable is made of, for example, a conductor wire 1 that is a tubular inner conductor and an insulating material wound around the conductor wire 1, as shown in FIG. Insulating string 2, insulating tube 3 made of an insulating material covering conductor wire 1 and insulating string 2, tubular outer conductor 4 covering insulating tube 3, sheath 5 made of an insulating material covering outer conductor 4, and insulating tube 3 and the outer conductor 4 are provided.
The outer conductor 4 is formed with a slot 4a, and the sheath 5 is provided with a hanging line 6.

The optical fiber 20 of the cable 200 with a load detection function is spirally wound around the conductor wire 1 via the insulating string 2 and the insulating tube 3.
As described above, since the optical fiber 20 is spirally wound around the conductor wire 1, when a load acts on the cable 10 with a load detection function, the load easily acts on the optical fiber 20.

An optical device 50 having a light source for emitting laser light to the core 21 of the optical fiber 20 and a detector for detecting scattered light in the core 21 is connected to one end of the optical fiber 20 of the cable 200 with load detection function. By doing so, as described above, the location where the load is applied to the cable 200 with the load detection function is detected so that the location where the optical fiber 20 is deformed or distorted is detected using the optical fiber sensing technology. can do.
In addition, the optical fiber 20 of the cable 200 with a load detection function is not limited to being disposed between the insulating tube 3 and the outer conductor 4, and may be disposed between other members.

  As described above, according to the cables 100 and 200 with the load detection function of the present embodiment, it is possible to detect a location where a load is applied to the cable.

  The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Conductor wire 11 Conductor 12 Insulation layer 20 Optical fiber 21 Core 22 Cladding 30 Sheath 50 Optical device 100 Cable with load detection function 1 Conductor wire 2 Insulation string 3 Insulation tube 4 External conductor 4a Slot 5 Sheath 6 Hanging line 200 Cable with load detection function

Claims (4)

At least one conductor wire;
A cable with a load detection function comprising: at least one optical fiber along a direction in which the conductor wire extends;
An optical device having a light source that emits laser light to the core of the optical fiber and a detector that detects scattered light in the core is connected to one end of the optical fiber, and the optical fiber is deformed. A cable with a load detection function, which is configured to be detectable.   The cable with a load detection function according to claim 1, wherein the optical fiber is twisted together with the conductor wire.   The cable with a load detection function according to claim 1, wherein the optical fiber is spirally wound around the conductor wire. The cable with a load detection function according to claim 1, wherein the optical fiber and the conductor wire are covered with a sheath.

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