JPH0654007U - Insulator for optical fiber - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to pull out an optical fiber from a high voltage side to a low voltage side without attaching dirt to the surface of the optical fiber or damaging the optical fiber. [Construction] A guide groove 22 extending from one end to the other end is provided on the outer peripheral portion of an insulating rod 21. Insert the optical fibers 14 and 15 into the guide groove of the insulating rod 21,
One end and the other end of 4, 15 are pulled out from one end and the other end of the insulating rod. The insulating rod 21 is covered with the optical fibers 14 and 15 by the resin mold portion 25.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is an insulator for an optical fiber used for guiding optical sensor information obtained from an optical sensor such as an optical CT or optical PT attached to a high voltage part to a low voltage side through an optical fiber in a gas insulation switchgear or the like. It is about.

[0002]

[Prior art]

 In electrical equipment such as gas-insulated switchgear, when detecting the current or voltage of the high-voltage part and extracting the detection result to the low-voltage side, in order to facilitate insulation, light such as optical CT or optical PT Advantageously, the sensor is used to transmit the optical sensor information obtained from the optical sensor through the optical fiber to the low voltage side.

As a means for transmitting optical information, an optical fiber cable having a structure in which a bare optical fiber (bare optical fiber) having a core and a clad covering the core is covered with a protective clothing such as vinyl is usually used. It is used. However, since the protective clothing used for optical fiber cables does not have a very high dielectric strength, optical fiber cables that are generally used as a means for transmitting signals obtained from optical sensors placed in high-voltage parts can be used as they are. If used, a flashover may occur between the high voltage part and the ground through the protective clothing of the optical fiber. Therefore, in this type of application, it is considered to use a bare optical fiber having no protective clothing, and in that case, a drawing structure shown in FIG. 6 or 7 is proposed.

The example shown in FIG. 6 shows a case where an optical fiber 4 led out from an optical CT 3 attached to a main circuit conductor 2 arranged in a metal container 1 of a gas insulated switchgear is drawn to the outside. Then, the optical fiber 4 is wound around the outer circumference of the insulating guide rod 5 provided between the conductor 2 and the metal container 1, and is guided to the vicinity of the metal container 1. The metal container 1 is provided with a hole 1a for drawing out an optical fiber, and a relay connector 6 is attached so as to hermetically close the hole 1a, and the optical fiber 4 is led out to the outside through the relay connector 6. And is connected to the monitoring device 7 or the like. The container 1 is filled with SF ₆ gas.

In the example shown in FIG. 7, the optical fiber 4 is pulled out from the tank 1 ′ on the ground side of the electric device. In this example, the insulator 8 is attached to the cover plate 1 a ′ of the tank 1 ′, An optical fiber 4 ′ is wound around an insulating rod 9 provided inside the insulator 8. The optical fiber 4'derived from the optical sensor in the tank 1'is connected to the lower end of the optical fiber 4'through a relay connector 6 attached to the cover plate 1a 'of the tank 1', and the upper end of the optical fiber 4'is insulated. It is led out to the outside through a relay terminal 6 ′ attached to an end plate 10 provided on the upper end of the insulator 8.

[0006]

[Problems to be solved by the device]

 The conventional optical fiber drawing structure has a problem that the bare optical fiber is arranged to be exposed, so that the optical fiber is easily damaged. Further, since the optical fiber is exposed, there is a problem that dirt easily adheres to the surface of the optical fiber. If dirt adheres to the surface of the optical fiber, the dielectric strength of the surface of the optical fiber decreases, so it is necessary to remove the dirt, but it is difficult to remove the dirt adhered to the surface of the optical fiber. It was

An object of the present invention is to provide an optical fiber that can be pulled out from a high voltage side to a low voltage side without adhering dirt to the surface of the optical fiber or damaging the optical fiber. It is to provide an insulator for a fiber.

[0008]

[Means for Solving the Problems]

 The optical fiber insulator of the present invention comprises a resin-made insulating rod having a guide groove on the outer peripheral portion from one end to the other end, and one end of the insulating rod inserted into the guide groove of the insulating rod and the other. It is composed of an optical fiber led from the end to the outside, and a resin molding part for molding an insulating rod together with the optical fiber.

The optical fiber used here is a bare optical fiber which is not covered with protective clothing such as vinyl, but as the optical fiber, a fiber consisting of a core and a clad may be used. You may use what coat | covered the outer periphery with the coating (jacket) of silicone rubber or Teflon.

As the resin forming the resin mold portion, it is preferable to use the same resin as the resin forming the insulating rod.

[0011]

[Action]

 If the optical fiber is inserted into the guide groove provided on the insulating rod as described above and the insulating rod is molded with resin together with the optical fiber, the optical fiber is protected by the resin molding part, It can prevent damage and dirt on the surface of the optical fiber.

When the optical fiber is molded with resin, stress is applied to the optical fiber due to the difference between the coefficient of thermal expansion of the resin and the coefficient of thermal expansion of the optical fiber, but as described above, the optical fiber is guided by the insulating rod. When the resin is inserted into the groove and molded with resin, the mold resin that has entered the guide groove adheres closely to the resin of the insulating rod that is the core, so that the optical fiber is hardly stressed. In this case, it is preferable to make the width of the guide groove sufficiently narrow and make the depth of the guide groove sufficiently larger than the groove width.

[0013]

【Example】

 1 to 3 show an embodiment of the present invention. In FIG. 1, 11 is a metal container of a gas insulated switchgear, 12 is a main circuit conductor arranged in the container 11, and an optical CT 13 is attached to the main circuit conductor 11. This optical CT is a known one that includes a core 13a forming an annular magnetic path surrounding the main circuit conductor 11 and a Faraday element inserted in the magnetic path of the core. The optical CT has an input side optical fiber 14 for giving incident light and an output side optical fiber 15 for leading out the emitted light (light including current information) from the Faraday element via connectors 16 and 17, respectively. Connected. As the optical fibers 14 and 15, bare fibers without a protective coating are used.

An optical fiber insulator 20 used for pulling out the optical fibers 14 and 15 is provided with an insulating rod 21 made of resin, and the insulating rod 21 has an outer peripheral surface as shown in FIG. A guide groove 22 is formed in a spiral shape extending from one end to the other end of the guide groove 22. The width dimension of the guide groove 22 is set to the minimum required for inserting the optical fibers 14 and 15, and the depth of the guide groove 22 is set sufficiently larger than the groove width. . The optical fibers 14 and 15 are inserted into the guide groove 22 from one end side of the insulating rod 21 and are drawn out to the other end side of the insulating rod 21 through the guide groove. Cup-shaped fittings 23 and 24 are respectively arranged on the upper end and the other end of the insulating rod 21, and the resin molding portion 25 made of the same resin as the resin forming the insulating rod 21 allows the insulating rod 21 and the mounting bracket 23 and 24 and the optical fibers 14 and 15 are molded. The resin mold portion 25 is formed by inserting the insulating rod 21 and the fittings 23 and 24 into a mold and injecting resin into the mold.

One ends and the other ends of the optical fibers 14 and 15 are led out to the outside through holes 23 a and 24 a provided in the fittings 23 and 24, respectively.

The insulating rod 21, the mounting brackets 23 and 24, the optical fibers 14 and 15, and the resin mold portion 25 constitute an optical fiber insulator 20.

This insulator is disposed between the main circuit conductor 12 and the metal container 11, and the mounting members 23 and 24 are attached to the fixing members 27 and 28 fixed to the main circuit conductor 12 and the metal container 11, respectively. It is fitted and attached. Optical connectors 30 and 31 are attached to the other ends of the optical fibers 14 and 15 led out from the lower end side of the insulator, respectively, and these connectors are connected to a relay connector 32 attached to the metal container 11. Optical fiber cables 33 and 34 are connected to the relay connector 32 from the outside of the metal container 11, and incident light is applied to the optical CT 13 through the optical fiber cable 33 and the optical fiber 14. An optical signal obtained from the optical CT 13 is given to an external monitoring device or the like through the optical fiber 15 and the optical fiber cable 34.

In the above-mentioned embodiment, the insulator 20 is arranged in the container 11. However, as shown in FIG. 4, one mounting member 24 is provided with a flange 24a, and the flange 24a of the mounting member 24 is The insulator 20 may be attached to the container 11 by connecting the periphery of the opening 11a provided in the container 11 via the packing 35. In the above-described embodiment, the outer surface of the resin mold portion 25 is formed smooth, but as shown in FIG. 5, in order to increase the creepage insulation distance of the resin mold portion 25 and increase its dielectric strength, Like the usual insulator, a large number of pleats 25a may be provided on the outer surface of the resin mold portion 25.

Further, in the embodiment shown in FIGS. 1 to 3, a part of the fittings 23 and 24 is projected from the resin mold portion 25. However, as shown in FIG. 5, the fittings 23 and 24 are The whole of the above may be covered with the resin mold portion 25.

When the optical fibers 14 and 15 are inserted into the guide groove provided in the insulating rod 21 as described above and the insulating rod is molded together with the optical fiber by the resin molding portion 25, the optical fibers 14 and 15 are Since it is covered and protected by the resin mold portion 25, it is possible to prevent the optical fibers 14 and 15 from being damaged and from being contaminated on the surface of the optical fibers.

When the optical fiber is molded with resin, stress is applied to the optical fiber due to the difference between the coefficient of thermal expansion of the resin and the coefficient of thermal expansion of the optical fiber. When the resin is inserted into the guide groove and molded with resin, the mold resin that has entered the guide groove adheres to the resin of the core insulating rod, and the insulating rod absorbs stress. The fiber is barely stressed. In this case, it is preferable that the width of the guide groove is sufficiently narrow and the depth of the guide groove is sufficiently larger than the groove width.

When an optical fiber having a coating layer acting as a buffer layer on the outermost circumference is used, stress applied to the optical fiber can be reduced. When an optical fiber having a structure in which the outer circumference of the cladding is covered with a coating of silicon rubber or Teflon, the coating layer can be used as a buffer layer.

In the above-described embodiment, the guide groove of the insulating rod 21 is formed in a spiral shape. However, if the guide groove is formed in a spiral shape in this way, the creepage insulation distance can be increased, so that the insulating rod 21 is formed. The length can be shortened to obtain a predetermined insulation performance, and the insulator can be downsized. However, the present invention is not limited to such a case where the guide groove is provided in a spiral shape, and for example, a linear guide groove may be provided from one end side to the other end side of the insulating rod 21. Good.

In the above embodiment, a bare optical fiber without a protective coating is used, but an optical fiber with a protective coating may be used.

In the above embodiment, the mounting brackets 23 and 24 are provided at both ends, but the shape of these mounting brackets is arbitrary, and a mounting bracket having an appropriate structure should be used according to the mounting location. You can

[0026]

[Effect of device]

 As described above, according to the present invention, the optical fiber is inserted into the guide groove provided in the insulating rod, and the insulating rod is molded together with the optical fiber by the resin. Protects the optical fiber from damage and prevents the surface of the optical fiber from being contaminated with dirt.

Further, according to the present invention, since the optical fiber is inserted into the guide groove of the insulating rod and is molded with resin, it is possible to prevent stress from being applied to the optical fiber when forming the resin mold portion. There are advantages.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an embodiment of the present invention.

FIG. 2A is a perspective view showing an insulating rod used in the embodiment of FIG. (B) is an enlarged view near one end of the insulating rod of (A).

FIG. 3 is a sectional view showing the structure of the insulator of the embodiment of FIG.

FIG. 4 is a sectional view showing an essential part of another embodiment of the present invention.

FIG. 5 is a sectional view showing a main part of still another embodiment of the present invention.

FIG. 6 is a schematic diagram showing a conventional optical fiber drawing structure.

FIG. 7 is a cross-sectional view showing another conventional optical fiber drawing structure.

[Explanation of symbols]

 11 Metal Container 12 Main Circuit Conductor 13 Optical CT 14 Optical Fiber 15 Optical Fiber 20 Insulation for Optical Fiber 21 Insulating Rod 22 Guide Groove 23 Mounting Metal Fitting 24 Mounting Metal Fitting 25 Resin Mold Section

Claims (1)

[Scope of utility model registration request] 1. An insulating rod made of resin having a guide groove on an outer peripheral portion from one end to the other end, and inserted into the guide groove of the insulating rod and led out from one end and the other end of the insulating rod. Insulator for an optical fiber, comprising: a molded optical fiber; and a resin molding portion that molds the insulating rod together with the optical fiber.