JPH0644432B2 - Lightning arrester - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester having a lightning protection element built-in, and more particularly to a lightning protection insulator used in an insulator device for an overhead power transmission line.

[Prior Art] Conventionally, as a lightning arrester with a built-in lightning arrester,
The one disclosed in Japanese Patent Publication No. 48588 is used. This lightning protection insulator will be described with reference to FIG. 9. A plurality of lightning protection elements 61 are stacked, and electrodes 62 and 63 are provided at the upper and lower ends thereof, respectively.
The lightning protection element 61 is covered with a heat-shrinkable tube 64 to fix the same, and the mold range 65 is provided outside the heat-shrinkable tube 64.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional lightning protection insulator, when the element part is electrically destroyed by an unexpected electric shock and a conductive state is generated and a high temperature and high pressure arc is generated, the entire mold range 65 is scattered. There was a problem of destruction.

An object of the present invention is to provide a lightning protection insulator that solves the above problems.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a polymer layer having a lightning protection element interposed between electrodes on the ground side and the charging side and having an insulating fold on the outside of the lightning protection insulator. A configuration is adopted in which a rubber mold is formed by coating, and a thin portion for releasing pressure when the lightning protection element is conducted is formed between insulating folds of the rubber mold.

[Operation] Since the present invention employs the above means, when an arc is generated in the element part, first, the high temperature / high pressure arc melts and destroys the thin portion and is guided to the outside, so that scattering due to the destruction of the entire lightning protection insulator is suppressed. To be done.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a suspension fitting 2 is attached to a steel tower 1 with bolts 3
The hanging metal fitting 2 supports a hanging metal fitting 4 so as to be orthogonal to the hanging metal fitting 2, and the hanging metal fitting 4 supports a connecting yoke 6 via a connecting pin 5. Suspension insulators 7, 7 are rotatably supported on the left and right ends of the connecting yoke 6 via connecting pins 8, respectively.

The first connecting links 10 and 10 are supported at the lower end portions of the two suspension insulators 7 and 7 via connecting pins 9, respectively.
The connecting yoke 1 is connected to 0 and 10 via connecting pins 11 and 11.
2 are supported. The connecting yoke 12 has a connecting pin 1
The second connecting link 14 is supported via the
4, a clamp 16 is supported via a connecting pin 15,
An electric wire 17 is suspended and supported by the clamp 16. A discharge electrode 12a is provided at the center of the upper surface of the connecting yoke 12.

A lightning protection insulator 19 is attached to the connecting yoke 6 via a bracket 18 and a support fitting 20.

Next, the lightning protection insulator 19 will be described in detail.
As shown in FIG. 4, a cylindrical grounding having a step portion 22a is provided at the upper end of a pressure resistant insulating cylinder 21 made of a material such as reinforced plastic (FRP) having excellent mechanical strength and heat resistance and pressure resistance. The side electrodes 22 and the cylindrical power-supply-side mounting brackets 23 each having a step portion 23a at the lower end are respectively fitted,
It is fixed by an adhesive 24. In addition, withstand voltage insulation cylinder 2
An annular groove 21a is formed on the outer peripheral surface of both ends of 1, and the annular groove 2a is formed on the inner peripheral surfaces of the ground-side electrode 22 and the power-supply-side mounting bracket 23.
2b and 23b are formed to increase the adhesion area and strengthen the adhesion. The support fitting 20 is fitted around the upper portion of the ground electrode 22. As shown in FIG. 5, gas escape holes 21b are formed in the upper, middle and lower parts of the pressure-proof insulating cylinder 21 at every 180 ° in the diameter direction of the insulating cylinder 21. The gas escape hole 21b is connected to the ground electrode 2
It is efficient to provide them in the vicinity of 2 and the power supply side mounting bracket 23 and in the vicinity of the intermediate portion thereof.

A female screw 23 is provided on the inner peripheral surface of the lower portion of the power-supply-side mounting bracket 23.
c is formed, and as shown in FIG.
After screwing the fastening metal fitting 25 having a, the female screw 23
The loosening is prevented by the stop ring 26 fitted in the lower part of c. A female screw 25b is provided on the inner peripheral surface of the tightening fitting 25.
Is formed, and a spring receiving fitting 27 having a male screw 27a is screwed.

Further, a male screw 23d is formed on the outer peripheral surface of the lower portion of the power-supply-side mounting bracket 23, and a cylindrical power-supply-side electrode 28 having a bottom and having a female screw 28a is screwed and fixed. This charging side electrode 2
An annular projection 28b is provided in the vicinity of the center of the bottom portion of 8, and a plurality of disc springs 29 are provided between the spring receiving fitting 27 and the spring receiving metal 27 to prevent the power-supply-side electrode 28 from loosening. ing. Further, the discharge electrode 30 is provided on the lower surface of the charging side electrode 28.
Is fixed by screwing, and the discharge electrode 12a of the connecting yoke 12 is fixed.
And an air discharge gap G is formed between them.

In the withstand voltage insulating cylinder 21, a plurality of lightning protection elements 31 mainly made of zinc oxide and made of a material having a nonlinear voltage-current characteristic are arranged in series. As shown in FIG. 7, a metallikon 32 is provided on the upper and lower surfaces of each lightning protection element 31, and a conductive spacer 33 made of a thin plate of light metal lead, aluminum, copper or the like is interposed between each lightning protection element 31, and each lightning protection element 31 is provided. An insulating layer 34 is formed on the outer peripheral surface of the element 31 to prevent the arc from flying between the outer peripheral edges of the conductive spacers 33.

An element pressing metal fitting 35 is arranged on the upper end of the lightning protection element 31 via a conductive spacer 33, and is fixed through the insertion hole 22c inside the ground side electrode 22 shown in FIG. 8 via a cylindrical insulating spacer 37. A plurality of disc springs 38 for applying a contact pressure to the lightning protection element 31 and a conductive spacer 39 for adjusting the contact pressure are interposed between the leakage current lead-out terminal 36 and the leakage current lead-out terminal 36. A conductive member 40 having a cross-sectional shape is interposed at three locations in the disc spring 38 to improve electrical connection.

Further, an element pressing metal fitting 35 is arranged at the lower end of the lightning protection element 31 via a conductive spacer 33, and a disc similar to the above is provided between the lightning protection element 31 and the spring pressing metal fitting 41 engaged with the upper surface of the tightening metal fitting 25. A spring 38 and a conductive spacer 39 are interposed, and a conical member 40 similar to the above is interposed in the disc spring 38.
In this way, the lightning arrester 31 is connected to the leakage current extraction terminal 3
6 is electrically connected to the voltage application side electrode 28 and is energized and held.

The insulating spacer 37, the engaging portion 36a of the leakage current drawing terminal 36, the conductive spacers 39, 39, and the spring retainer 4
1. The heat-shrinkable tube 42 made of FPDM rubber, polyethylene, or fluororesin is coated on the outer peripheral surfaces of the element holding metal fittings 35, 35 and the lightning protection element 31.
Together with the leakage current lead-out terminal 36 and the spring retainer 41 are integrally fixed and enclosed.

The heat-shrinkable tube 42 is fitted to the annular groove 43 formed by the insulating layer 34 and the conductive spacer 33 shown in FIG.
Is formed to a thickness of. By bonding the heat-shrinkable tube 42 and the lightning protection element 31 to each other, it is possible to more completely prevent the generation of voids and improve the element holding function.

Between the withstand voltage insulating cylinder 21 and the lightning protection element 31, between the ground-side electrode 22 and the leakage current drawing terminal 36, and withstand voltage insulating tube 2
1, a rubber mold 44 made of EPDM rubber having heat shrinkability is formed, extends to the lower outer peripheral surface of the ground side electrode 22 and the upper outer peripheral surface of the voltage application side electrode 28, and has a fold 44a on the outer periphery. Are integrally formed. This rubber mold 44 is an EPDM that is in a fluidized state at about 150 ° C.
It is molded by injecting rubber at a pressure of about 150 kg / cm ² .
Annular groove 2 on the inner side and the upper side of the ground electrode 22
2d, the annular groove 28c on the outside of the charging side electrode 28 and the annular groove 36b on the outer periphery of the leakage current lead-out terminal 36 are bonded to the EPDM rubber and metal under the conditions when the EPDM rubber is injected to improve the airtightness. Vulcanizing adhesive is pre-applied.

The rubber mold 44 between the ground-side electrode 22 and the leakage current lead-out terminal 36 is formed of rubber that flows from the through hole 22e inside the ground-side electrode 22 during molding.

Further, in the rubber mold 44, as shown in FIG. 5, a pressure release port 44b is recessed at a position corresponding to the gas escape hole 21b of the pressure-proof insulating cylinder 21, and a thin portion 44c is formed.

An arcing ring arm portion 45 is fixed to a mounting piece 20a provided on one side of the support fitting 20 with a bolt, and a tip of the arcing ring arm portion 45 corresponds to the pressure release port 44b of the upper portion. Arcing ring 46
Is provided. On the other hand, a mounting bracket 47 is fixedly attached to the outer periphery of the lower portion of the power-supply-side electrode 28, and the arcing ring arm portion 45 is also fixed to the mounting piece 47a with bolts.
The arcing ring 46 is provided at the tip of the arcing ring arm 45 so as to substantially correspond to the pressure release port 44b at the lower portion.
Is provided.

Next, the operation of the suspension insulator device configured as described above will be described.

When a lightning surge enters the electric wire 17 due to an electric shock, current is arc-discharged from the electric wire 17 to the discharge electrode 30 from the discharge electrode 12a of the clamp 16 → the second connecting link 14 → the connecting yoke 12 through the air discharge gap G. , From the power-supply side electrode 28 to the power-supply side mounting bracket 23 → tightening bracket 25 → spring retainer bracket 4
1 → conductive spacer 39 → conductive member 40 → flows to the lightning arrester element 31 through the lower element pressing fitting 35, and further, the upper element pressing fitting 35 → conductive member 40 → conductive spacer 39 → leakage current lead terminal 36 → connection yoke 6 After that, it flows from the tower 1 to the earth. The subsequent flow accompanying this is blocked by the lightning protection element 31.

Further, when the lightning arrester 31 is abnormally discharged due to an unexpected large-scale electric shock and a high-temperature and high-voltage arc is generated, a part of the heat-shrinkable tube 42 and the thin-walled portion of the rubber mold 44 near the gas escape hole 21b of the pressure-proof insulating cylinder 21. 44c is softened or melted and destroyed, scattered by high-pressure gas, and an arc discharge path communicating with the outside is forcibly formed. The arcs emitted to the outside of the insulator 19 are vertically connected to each other and move between the arcing rings 46.

In the embodiment of the present invention, even when an arc occurs in the element portion, the thin portion 44c of the rubber mold 44 is first melted and destroyed, and the high-pressure gas is quickly released to the outside. The internal pressure rises and the entire lightning insulator can be prevented from scattering and breaking.

The present invention is not limited to the above embodiment,
You may implement as follows.

The rubber mold 44 may be formed of silicon rubber or butyl rubber instead of EPDM rubber. The mold material and the heat shrinkable tube 42 are preferably made of the same material. By doing so, the bondability between the heat shrinkable tube 42 and the rubber mold 44 is improved.

[Effects of the Invention] As described in detail above, according to the present invention, there is an excellent effect that the scattering destruction of the entire lightning protection insulator can be prevented when an arc is generated in the element portion due to an electric shock.

[Brief description of drawings]

FIG. 1 is a front view showing a suspension insulator device equipped with a lightning arrester of the present invention, FIG. 2 is a front view showing the entire lightning arrester device, and FIGS. 3 and 4 are partial longitudinal sectional views of the lightning insulator. 5 is a sectional view taken along the line AA of FIG. 3, FIG. 6 is a reduced end view taken along the line BB of FIG. 4, FIG. 7 is an enlarged sectional view around the conductive spacer, and FIG.
FIG. 9 is a sectional view taken along line CC of FIG. 3, and FIG. 9 is a sectional view showing a conventional example. 21 ... Withstand voltage insulating cylinder, 21b ... Pressure release hole, 22 ... Grounding side electrode, 23 ... Charging side electrode, 31 ... Lightning arrester element, 44
...... Rubber mold, 44a folds, 44b pressure release port, 44c thin section.

Claims (1)

[Claims] 1. A lightning protection element is interposed between electrodes on the grounding side and a charging side, and a rubber mold of a polymer layer having an insulation fold is formed on the outside of the lightning protection insulator by coating, and between the insulation folds of the rubber mold. A lightning protection insulator characterized in that a thin portion for releasing pressure is formed on said lightning protection element.