JPH0677415B2 - Insulator with built-in optical sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an insulator with a built-in optical sensor, which detects a voltage or an electric wire of a transmission and distribution line by a detection unit and transmits the signal through an optical fiber. is there.

(Prior Art) Conventionally, as this type of insulator, there is one disclosed in Japanese Patent Laid-Open No. 60-225806, and as shown in FIG.
The through hole 22 is formed in the axial center of the optical fiber 23, and the optical fiber 23 is housed in a spiral shape in the trough 22a formed in the inner peripheral surface of the through hole 22.

(Problems to be Solved by the Invention) However, the conventional optical sensor composite insulator has a through hole inside.
Since there are 22 and the pleats are formed on the inner peripheral surface of the through hole 22, the cavity becomes large and the mechanical strength of the insulator is lowered, and the through hole 22 is formed between the upper and lower end surfaces of the insulator. Since it travels straight along the axis, the insulation distance of the through hole 22 is the same as the total length of the insulator, and the creepage leakage distance is also the through hole, for example.
Although it can be increased by deepening the folds in 22, the mechanical strength of the insulator and the above-mentioned strength in the thickness direction of the insulator main body will be reduced. However, there is a problem that the insulator function with respect to the lightning impulse voltage and the like is easily deteriorated.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention inserts an optical fiber into a spiral through hole formed along an axis inside a spiral insulator body, A detection unit having a built-in optical sensor connected to the tip of the optical fiber is fixedly housed in an inner concave portion of a cap fitting attached to the upper end of the insulator body for holding an electric wire, and the lower end of the optical fiber is fixed to the insulator. The means for connecting to the optical connector is adopted on the bottom surface of the base metal fitting attached to the lower end of the main body.

(Operation) The present invention operates as follows by adopting the above means.

Since the detection unit is arranged near the electric wire, stable detection accuracy can be obtained, and since the optical fiber and the detection unit are protected in the recess, the light transmission is stably maintained and the damage due to the external force can be prevented.

The optical fiber can be inserted into the through hole from one opening end of the insulator body, the optical fiber can be arranged inside the insulator body using the through hole as a guide, and the optical fiber can be easily pulled out from the other open end.

In addition, since the through hole is a small hole occupying the cross section of the insulator body, it does not impair the mechanical strength of the insulator body, and is formed spirally along the inner axis of the insulator body. It is possible to easily secure the insulation distance or the creepage leakage distance from the opening end to the other opening end, and the insulator itself can maintain its original function without impairing the electrical insulation strength.

(Embodiment) Hereinafter, one embodiment embodying the present invention will be described with reference to FIG. 1. The lower end portion of the porcelain insulator main body 1 integrally formed with a plurality of folds 1a on the outer peripheral surface has cement. The base metal fitting 3 is fitted and fixed by a filler 2 such as. The base metal fitting 3 is fastened and fixed by bolts to, for example, a wire arm of a utility pole. A cap metal fitting 4 having a receiving groove 4a on the top surface is similarly fitted and fixed to the upper end portion of the insulator body 1 by a filler 2. The electric wire 5 of the electric line is fastened and fixed to the upper surface of the cap fitting 4 by a bolt 6, a nut 7 and a holding fitting 8.

Inside the porcelain insulator main body 1, there is provided a through hole 10 having a circular cross section formed by a manufacturing method described later.
An intermediate portion of the through hole 10 is a spiral portion 10a along the axis of the insulator body 1, and upper and lower end portions thereof are straight portions 10b. The through hole 10 may be formed in a spiral shape as a whole, or may have an arbitrary cross-sectional shape, and the inner diameter may be set to a dimension that allows insertion of the optical fiber 9 or the optical fiber cable. However, considering the convenience of forming the insulator body, about 1 mm to 10 mm is practical. The optical fiber 9 is inserted through the opening of the through hole 10. At this time, the through hole 10 itself serves as a guide to guide the tip of the optical fiber 9 so that it can be easily pulled out to the other opening. 9 Considering the elastic force or flexibility of itself, the through hole
It is desirable to set the radius of curvature of the spiral portion 10a of 10 to about 30 mm to 40 mm. After inserting the optical fiber 9, the through hole 10
Although not shown, for example, an inorganic material such as low melting point glass may be welded to the insulator body between the inner peripheral surface of the optical fiber 9 and the optical fiber 9.

Further, the optical fiber 9 is connected to a detection unit 12 having a built-in optical sensor such as a magnetic field sensor or an electric field sensor at its tip, and is housed in a compound or the like in the inner recess 4b of the cap metal fitting 4. The other end of the optical fiber 9 is connected to the optical connector 13 and accommodated in a recess 3a formed in the bottom surface of the base metal fitting 3. The optical connector 13
Further, an optical transmission line such as the optical fiber cable 14 is extended and connected to the measuring device.

In addition, in the above-mentioned embodiment, if a more practically desirable setting is described, the relationship between the body diameter D of the insulator body 1 and the diameter d of the spiral portion 10a of the through hole 10 is as shown in FIG. d / D
If the length of the through hole 10 is set so that the insulation distance in the through hole 10 is about 1.5 times or more of the insulating distance of the outer surface of the insulator body 1, the lightning is It is possible to reliably prevent the internal flash path and the electrical penetration in the thickness direction due to the impulse voltage.

Next, an example of a method of manufacturing the porcelain insulator body 1 will be described with reference to FIGS. 2 and 3.

First, a core material 15 including a spiral portion 15a and a straight portion 15b is prepared from a flammable material such as paraffin or plastic.

Next, the both ends of the core material 15 are locked by the stoppers 17 to the upper and lower ends of the pair of left and right insulator forming dies 16 having a semi-cylindrical shape having the cavity 16a for molding the insulator body 1. Positioned at the center of the cavity 16a, both molds 16 are fixed by the upper and lower fixing frames 18. Then, the molding die 16
When the base slurry is injected into the cavity 16a from an injection port (not shown) provided in the core, dehydrated, released from the mold, and fired through a drying process, the core material 15 is burned off and the core is placed inside the insulator body 1. The through holes 10 are formed, leaving holes that follow the shape of the material 15.
However, the method of molding the insulator body 1 is not limited to the injection molding, and a press manufacturing method is also possible. The core material 15 burns and disappears, but can be removed by a slight amount of debris or compressed air.

The present invention can also be embodied as follows.

Effects of the Invention As described in detail above, according to the present invention, the optical fiber can be easily disposed only by inserting it into the through hole formed by bypassing the inside of the insulator body, and the through hole is formed in the cross section of the insulator. Since the tightening rate is small, the mechanical strength of the insulator is not lowered, and the insulation distance inside is easy to be taken, so the insulator itself can maintain its original function stably without deteriorating the electrical performance, and it can be detected. The accuracy and the light transmission accuracy are stably maintained, and the damage of each component is prevented.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a central portion showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a central portion showing an example of a method for manufacturing an insulator main body, and FIG. 3 is a line AA in FIG. FIG. 4 is a sectional view showing a conventional example. 1 ... Insulator main body, 9 ... Optical fiber, 10 ... Through hole, 10a, 15a
... spiral part, 10b, 15b ... straight part, 12 ... detection unit incorporating optical sensor, 13 ... optical connector, 15 ... core material, 16 ... insulator molding die, 16a ... cavity.

Claims (1)

[Claims] 1. An optical sensor connected to the tip of an optical fiber (9) by inserting an optical fiber (9) into a spiral through hole (10) formed in the insulator body (1) along the axis. The built-in detection unit (12) is fixedly housed in the inner recess (4b) of the cap fitting (4) that is attached to the upper end of the insulator body (1) and holds the electric wire (5). Attach the lower end of (9) to the insulator body (1).
An insulator with a built-in optical sensor, which is connected to an optical connector (13) on the bottom surface of a base metal fitting (3) attached to the lower end of the.