JPH0529005U - End structure of insulator with built-in optical fiber - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an end structure of an insulator with a built-in optical fiber that is easy to handle and is less likely to damage the optical fiber. [Structure] A columnar insulator main body 1 has an elastic first end portion.
A cap 16 formed of the mold layer 15 is provided.
The second mold layer 20 is provided on the upper end of the cap 16,
Protective tube 1 with inserted optical fiber 11
Fix the end of 9. When an external force pulling the protective tube 19 in the lateral direction acts, the second mold layer 20 and the first mold layer 15 are integrally curved due to the elasticity of the end of the protective tube 19 without the end of the protective tube 19 jumping up. Therefore, the optical fiber 11 is not damaged by the end of the protective tube 19.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an end structure of an insulator incorporating an optical fiber in which an optical fiber for transmitting an optical signal is penetrated in an insulator body.

[0002]

[Prior Art]

 For example, as disclosed in Japanese Patent Application Laid-Open No. 1-148018, an optical CT sensor is provided on a bus bar, and an optical signal detected by the optical CT sensor is transmitted to an earth-side measuring section by an optical fiber so that it can be used in a substation. A fault zone detection system that detects a fault such as a ground fault is known. In this system, an optical fiber built-in insulator is used, in which an optical fiber is inserted into a columnar support insulator to connect the charging side and the ground side. In this insulator with a built-in optical fiber, the optical fiber is penetrated into the through hole, and the optical fiber is pulled out from the end opening of the insulator. As shown in FIG. 6, the end structure of the insulator with a built-in optical fiber is such that the flexible first mold layer filled in the through hole is raised in a conical shape at the insulator end to form the cap 16. ing. The top of the cap 16 is formed with a columnar protruding column portion 17 for pulling out the optical fiber 11. The end structure of the insulator with a built-in optical fiber prevents the optical fiber 11 from being locally bent and damaged by the elasticity of the first mold layer 15.

[0003]

[Problems to be solved by the device]

 However, it is difficult to coat the optical fiber penetrating the inside of the insulator body with a mechanical strength sufficient to secure the insulation of the insulator. For this reason, the optical fiber 11 is not covered with a protective coating and is easily damaged, and is easily bent and damaged when a large bending force is locally applied. For this reason, it was necessary to handle it very carefully at the time of manufacturing and in the subsequent connection work with the optical sensor.

As a solution to this, it is sufficient to cover the entire optical fiber with a protective layer to provide mechanical strength, but it is difficult for the optical fiber in the insulator body to be electrically insulating.

In view of the above problems, the present invention is to provide an end structure for an insulator with a built-in optical fiber that is easy to handle, scratch-resistant, and highly reliable.

[0006]

[Means for Solving the Problems]

 Therefore, in this invention, the optical fiber pulled out from the top of the cap is inserted into the protective tube, and the end of the protective tube is covered with a pipe attached to the cap, and the second mold is inserted into this pipe. The layers are filled and fixed.

[0007]

[Action]

 When an external force is applied to the protective tube in a lateral direction, the external force is applied to the protective tube without directly applying the external force to the optical fiber. Since the end of the protective tube is fixed by the second mold layer, the second mold layer is integrally curved due to elasticity. At this time, since the first mold layer and the second mold layer are fitted in the pipe, the first mold layer and the second mold layer are not separated. Further, since the end portion of the protective tube is supported by the second mold layer and only the end portion of the protective tube does not bend in a jump shape, the optical fiber is not damaged by this end portion.

[0008]

【Example】

 An embodiment to which the present invention is applied will be described below in detail with reference to FIGS.

FIG. 1 shows an example applied to a support insulator in which flange metal fittings 2 and 3 are attached to both upper and lower ends of a cylindrical insulator body 1 made of porcelain. This support insulator is installed upright on a base 4 with a flange fixture 3 installed and fixed by bolts. On the upper end of the insulator main body 1, a support metal fitting 5 is attached to a flange metal fitting 2 via a lid 6. A terminal plate 9 provided with a contactor 8 for receiving the blade 7 of the disconnecting switch on one side is fixed to the support fitting 5. A bus bar (not shown) is connected to the other side of the terminal board 9.

A through hole 10 having a circular cross section is provided at the center of the axis of the insulator body 1, and an optical fiber 11 is penetrated into the through hole 10 and connected to a measuring unit (not shown). The optical fiber 11 pulled out from the upper part of the insulator body 1 is connected to the optical CT sensor 12.

The optical CT sensor 12 includes an iron core 13 arranged so as to surround the terminal plate 9 in an annular shape, and an optical magnetic field sensor 14 for converting an electric signal of a secondary current obtained by the iron core 13 into an optical signal. ing. The optical fiber 11 drawn out from the optical magnetic field sensor 14 penetrates the through hole 10 from the upper end of the insulator body 1, is drawn out to the lower end, and is connected to a measuring unit (not shown) provided on the ground side. The inside of the through hole 10 is filled with a first mold layer 15 made of silicon rubber to secure the insulation inside the through hole 10 and fix the optical fiber 11.

Since the upper and lower end portions of the insulator body 1 have substantially the same structure, the upper end portion will be described below as shown in FIG. 2. The first mold layer 15 filled in the through hole 10 is the insulator body. A cap 16 is formed on the upper end surface of No. 1 so as to further project in a conical shape. Since the first mold layer 15 has elasticity, the first mold layer 15 is bent according to the bending of the optical fiber 11 so that the optical fiber is not excessively bent. Further, a columnar projecting pillar portion 17 is formed on the top portion, and the optical fiber 11 is pulled out upward from this projecting pillar portion 17.

A short pipe 18 is fitted to the protruding column portion 17. The pipe 18 is made of a flexible silicone resin having higher rigidity than the first mold layer 15.

Further, the drawn out optical fiber 11 is inserted into a flexible long protective tube 19 made of Teflon or silicon. The protection tube 19 has higher rigidity than the optical fiber 11 and is configured to be largely bent without being locally bent even when a large external force is applied to the protection tube 19. Then, the end portion of the protective tube 19 is exposed to the inside of the pipe 18, and then the end portion of the protective tube 19 is formed by the second mold layer 20 formed by filling the pipe 18 with the room temperature curing type silicone resin. And the second mold layer 20 is integrally joined to the protruding column portion 17. Therefore, when an external force is applied to the pipe 18 in the lateral direction, the cap 16, the protruding column portion 17, and the second mold layer 20 are integrally curved by their respective elastic forces.

Next, the operation of this embodiment configured as described above will be described.

Now, for example, when an external force such as pulling laterally is carelessly applied to the protective tube 19 during the work of connecting the optical fiber 11 to the optical magnetic field sensor 14, the optical fiber 11 is directly affected by the external force. The external force acts on the protective tube 19 without applying the external force. Along with this, the cap 16, the protruding column portion 17, and the second mold layer 20 are integrally curved due to their respective elastic forces. In particular, the closer to the top of the cap 16, the greater the amount of bending and the local bending. Therefore, the optical fiber 11 protected by the cap 16, the protruding column portion 17, and the second mold layer 20 is not locally bent and broken or damaged. Particularly in this embodiment, the optical fiber 11 is housed in the protective tube 19, and the end portion of the protective tube 19 is supported by the second mold layer 20, so that only the end portion does not bend upward and bends. (2) Since it is curved integrally with the mold layer 20, it is possible to prevent the cutting failure of the optical fiber 11.

Further, since the optical fiber 11 pulled out from the end portion is inserted through the protective tube 19, it is possible to further prevent scratches during manufacturing and transportation.

[0018]

[Effect of the device]

 In this device, the optical fiber pulled out from the top of the cap is inserted into the protective tube, and the end of the protective tube is covered with a pipe attached to the cap, and the second mold layer is filled in the pipe. Since the optical fiber is adhered and fixed, it is easy to handle, the optical fiber is not easily scratched, and a highly reliable end structure of the optical fiber built-in insulator can be obtained.

[0019]

[Brief description of drawings]

FIG. 1 is a cross-sectional view with an optical CT sensor attached.

FIG. 2 is a partial cross-sectional view.

FIG. 3 is a partial cross-sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulator main body 10 ... Through hole 11 ... Optical fiber 15 ... First mold layer 16 ... Cap 18 ... Pipe 19 ... Protective tube 20 ... Second mold layer

Claims (1)

[Scope of utility model registration request] 1. An optical fiber (11) is inserted into the through hole (10) of a columnar insulator body (1) having a through hole (10) penetrating in the axial direction, and the inside of the through hole (10) is inserted. The first
An insulator with a built-in optical fiber, which is filled with a mold layer (15) and is provided with a cap (16) continuously protruding from the through hole (10) by integral molding at an end of the insulator body (1), wherein the cap ( The optical fiber (11) pulled out from the top of 16) is inserted into the protective tube (19), and the end of the protective tube (19) is capped (16).
An end structure of an insulator with a built-in optical fiber, characterized in that it is covered with a pipe (18) attached to, and a second mold layer (20) is filled and fixed in the pipe (18).