JPH06103608B2 - Lightning arrester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a suspension insulator type lightning arrester having both the function of a suspension insulator and the function of a lightning arrester.

(Prior Art) Conventionally, it has been considered to introduce a lightning arrester into a transmission line in order to absorb lightning and switching surges and prevent a ground fault in the transmission line. However, it is not preferable to attach a lightning arrester having only a lightning protection function to the transmission line because the transmission line tower structure and the insulator device are complicated. Therefore, the insulation of conventional insulators
Various lightning protection insulators having both a wire support function and a lightning arrester function have been proposed (see Japanese Patent Laid-Open No. 54-122898).

However, since this suspension type lightning arrestor embeds the lightning protection element in the head, it is necessary to concentrate the lightning protection function and the load bearing function as the suspension insulator near the central axis, that is, in the head. It is greatly increased, making it difficult to emphasize the lightning protection function and mechanical strength.

Therefore, the applicant of the present application provided an insulating support tube in the cap portion of the lightning protection insulator, embedded a lightning protection element having a non-linear voltage-current characteristic in the tube, and provided conductive cap-shaped electrodes at the upper and lower ends of the tube. We have proposed a lightning protection insulator in which the lightning protection element is electrically connected by a spring and a rubber-like adhesive is poured into the space between the electrode and the element to ensure airtightness.

(Problems to be solved by the invention) The improved lightning protection insulator has a large influence on the electric characteristics of the element because the rubber material essentially has some water permeability, and is unbearable for many years of use. Furthermore, when the voltage applied to the insulator under a special condition (during snow-covering, soiling, etc.) is transient compared to that during cleaning, or rises to 150 to 250% for a short time and the temperature of the lightning arrester rises, this thermal change Joins the adhesive part of the rubber adhesive. This temperature change from room temperature to high temperature is extremely severe, and due to this condition change, the adhesive agent separates from the surface of the porcelain or the cap metal member to form a gap. Therefore, there is a new problem that the airtightness and watertightness of the insulating support cylinder and the electrodes are broken, and the lightning protection element is deteriorated earlier due to the intrusion of water.

The present invention aims to solve the above problems.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention fixes a cap metal fitting to a cap-shaped cylindrical head formed in the upper central part of a cap, Insulator body is constructed by inserting and fixing pin metal fittings inside, and an insulating support tube is formed to project vertically in the cap portion, and a lightning protection element having a non-linear voltage-current characteristic is formed in the insulating support tube. Embedded, the upper and lower end surfaces of the insulating support tube, copper sulfide method, by applying a metallization layer with high adhesion to porcelain by silver carbonate method, etc., the lightning element end face is also metallized by other methods, These two surfaces are covered with a soft metal layer such as solder or a low-melting metal braze to form an airtight layer, and cap-shaped members electrically connected to the lightning protection element are formed at the upper and lower ends of the insulating support cylinder. Hand to crimp both upper and lower electrodes It has taken.

(Operation) In the present invention, since the airtightness is ensured by the metal layer having essentially no water permeability by the above-mentioned means, the deterioration of the electrical characteristics of the element is not seen for many years, and further, the excessive current due to the lightning surge in the transmission line. Is applied, the lightning protection element quickly reduces the resistance value and discharges a large current due to a lightning surge. Further, since the line voltage is low with respect to the follow current continuing to the lightning surge, the resistance value is immediately restored to restore the insulation, so that the follow current discharge is suppressed and interrupted and the electric line is normally restored. At this time, the heat generated by the lightning protection element due to the lightning current increases the voltage applied to the lightning protection insulator to 150 to 250% during a short period of time or transiently compared with the voltage applied to the lightning protection insulator under special conditions (during snow cover, pollution, etc.) Then, even when the temperature of the lightning protection element rises,
Since the adhesion between the metallized layer and the solder is extremely high, airtightness and watertightness are maintained.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a suspension insulator type lightning arrester 3 is mounted on an arm 1 provided on a steel tower (not shown) via a support metal fitting 2.
Are suspended in series, and the power transmission line L is supported at the lowermost end of the lightning protection insulator 3 via a suspension metal fitting 4.

As shown in FIG. 1, an insulator main body 5 constituting the lightning protection insulator 3.
Is a cap portion 5a, a fold portion 5b formed in an annular shape and concentric with the inner surface of the cap portion 5a, and a cylindrical head with a lid integrally formed on the central upper portion of the cap portion 5a. It is integrally molded with 5c. Further, a cap metal fitting 7 is capped and fixed to the outer periphery of the head 5c by cement 6, and an engaging concave portion 7a is formed in the metal fitting 7 so that the pin metal fitting 8 of the lightning protection insulator 3 directly above can be engaged. I have to. The upper part of the pin fitting 8 is the head 5c
Is fixed to the inside by cement 6 and the lower end is engaged with the engaging recess 7a of the cap fitting 7 of the lightning protection insulator 3 directly below. In this way, the plurality of lightning protection insulators 3 are connected in series.

The cap portion 5a is provided with a plurality of cylindrical insulating support cylinders 9 (three in this embodiment) at equal intervals and in the vertical direction.
It is integrally formed so as to penetrate through 5a. It is desirable that the insulating support cylinder 9 is brought close to the cap fitting 7 in order to improve the fouling property of the cap portion 5a corresponding to the portion where the support cylinder 9 is embedded. The upper and lower heights of the insulating support cylinder 9 are connected to each other by using the engaging recess 7a of the cap metal fitting 7 and the pin metal fitting 8 in a state where the upper and lower lightning protection insulators 3, 3 are inclined with their central axes crossing each other. It is decided to secure the work clearance at the time.

A plurality of lightning arresters 11, 11 which are mainly made of zinc oxide (ZnO) and have a non-linear voltage-current characteristic having excellent non-current interruption characteristics are fitted in the insulating support tube 9 and Lightning arrester 1
The low melting point glass material 12 and the organic insulating materials such as 1, 11 are bubble-free adhered by heat-resistant silicone rubber or the like, and metallized layers 23 are provided on the upper and lower ends of both elements 11 by metallikon or other method. ing. On the surface of the metallized layer 23, a metal thin protective plate 13 for conduction is provided. A metallized layer 10 is formed on the upper and lower end surfaces of the insulating support cylinder 9 by a copper sulfide method, a silver carbonate method or the like.
The surfaces of the protective plate 13 and the metallized layer 10 have excellent adhesion to both and are easily plastically deformed (melting point: 150 to 200 ° C.)
Alternatively, a soft metal layer 14, such as a low melting point metal braze, is welded in an airtight manner. By applying this metallized layer 10 to improve the adhesion between the insulating support tube 9 and the soft metal layer 14,
Even if the airtightly bonded portion is heated under special conditions, the support cylinder 9 and the soft metal layer 14 are prevented from separating from each other and the airtightness and watertightness are prevented from being broken.

Further, since the protective plate 13 and the metallized layer 10 are sealed in a substantially flat plate shape by the soft metal layer 14 which is easily plastically deformed, the application concentration on the insulating support cylinder 9 is eliminated.

Cap-shaped upper and lower electrodes 15 and 16 are fitted to the upper and lower ends of the insulating support cylinder 9, and are caulked to annular grooves 9a formed on the outer circumference of both ends of the insulating support cylinder 9. A pressure spring 17 having electrical conductivity and thermal conductivity is interposed between the inner surfaces of both electrodes 15 and 16 and the protective plate 13 for conduction, and the contact surfaces on the upper and lower sides are enlarged. The lightning protection element 11 is fixed by pressure contact between the upper and lower electrodes 15 and 16 by a pressing spring 17,
Also, the lightning protection element 11 and the electrodes 15 and 16 are connected to the protection plate 13 for conduction,
It is electrically connected by a pressing spring 17. Also, electrode 1
Rubber-like adhesive elastic body 20 is enclosed in the space inside 5,16,
In the unlikely event that the adhesive sealing surface is increased, the soft metal layer
Even if 14 is damaged, airtightness is ensured. By maintaining the airtightness in the insulating support tube 9 in this way, the deterioration of the lightning protection element 11 is prevented.

As shown in FIGS. 1 and 4, the upper and lower electrodes 15 and 16 are substantially circular outside the electrodes 15 and 16 so as to cover the electrodes 15 and 16 and to surround the cap fitting 7 or the pin fitting 8. The ring-shaped heat radiation covers 18 and 19 are crimped and fixed so that electricity can be conducted and heat can be transferred. A large number of fins 18a are radially provided outside the upper heat dissipation cover 18. The upper heat dissipation cover 18 is a cap fitting 7, and the lower heat dissipation cover 19 is a ring fitting or a fitting fitting 21, 22 having a certain width with the pin fitting 8.
And are electrically connected to each other. A plurality of lightning protection elements 11 are provided by the heat radiation covers 18 and 19.
The spaces are connected with low inductance, and the shunt effect is improved. Therefore, the heat radiation covers 18 and 19 alleviate the concentration of the electric field on the specific element 11. In addition, the heat of the heat dissipation cover 18 is transferred to the cap fitting 7 by the connecting fitting 21.
Since it is conducted to, the connecting metal fitting 21 also helps in heat dissipation.

Further, when it is desired to electrically connect the respective insulators with a lower inductance, it is sufficient to provide terminals for connection on the heat dissipation covers 18 and 19 and connect the terminals with a flexible conductor.

Next, the operation of the lightning protection insulator configured as described above will be described.

When an excessive voltage of lightning surge is applied to the power transmission line L, the current flows through the hanging metal fitting 4 to the pin metal fitting 8 of the lightning protection insulator 3 at the lowermost end, and the connecting metal fitting 22 → heat radiation cover 19 → electrode 16 → lower pressing spring.
17 → lower conductive protection plate 13 → lower metallized layer 23 → lightning protection element 11 → upper metallized layer 23 → upper conductive protective plate 13 → upper pressing spring 17 → electrode 15 → heat dissipation cover 18 → coupling 21 → It flows to the cap fitting 7. After that, it flows from the cap metal fitting 7 to the pin metal fitting 8 of the lightning protection insulator 3 directly above. Similarly, it is transmitted to a plurality of lightning protection insulators 3 connected in series, and is grounded from the cap fitting 7 of the uppermost lightning protection insulator 3 through the support fitting 2 and the arm 1 to the ground.

At this time, the lightning protection element 11 built in the insulator main body 5 quickly reduces the resistance value due to its characteristics and discharges a large current due to a lightning surge. Further, the lightning arrester element 11 immediately restores the resistance value and restores the insulation with respect to the follow current continuing to the lightning surge, so that the follow current discharge is suppressed and interrupted and the electric line is normally restored.

However, in the present embodiment, even if the lightning protection element 11 becomes conductive due to a large-scale lightning strike and an arc occurs and the inside of the insulating support cylinder 9 becomes a high voltage, the upper and lower electrodes 15 and 16 form a ring shape of the insulating support cylinder 9. Since they are only caulked in the groove 9a, both electrodes 15 and 16 easily separate from the insulating support cylinder 9 to radiate an arc to the outside to prevent damage and disconnection of the insulating support cylinder 9.

Further, since the electrodes 15 and 16 are fitted in the annular groove 9a of the insulating support cylinder 9 by the caulking method, the leak current and the lightning current at the time of insulator fouling do not flow in the airtight attachment portion of the soft metal layer 14, and Since no external load is applied, the airtight seal is not damaged.

In addition, under special conditions (when snowing, when polluting, etc.), the voltage applied to the lightning arrestor 3 rises transiently or for a short period of time to 150 to 250% compared to the time of cleaning, and the temperature of the lightning arrester element 11 rises. Since the adhesion between the metallized layer 10 and the soft metal layer 14 is high even at any time, no air gap is formed between the airtightly adhered portions, and airtightness and watertightness are secured. In addition, this heat has a good thermal conductivity, such as a conduction protection plate 13, a pressing spring 17, electrodes 15 and 16, and a heat radiation cover.
It is dissipated to the outside through 18,19 and the heat dissipation cover 18
Heat dissipation is promoted by the fins 18a.

The present invention is not limited to the above embodiment,
It may be embodied as follows.

Omit the pressing spring 17 and enclose the solder of good conductor.

Effects of the Invention As described in detail above, the present invention provides a metallized layer on both upper and lower end surfaces of an insulating support tube, and seals a soft metal layer on the upper surface of the insulating support tube, and the metallized layer, The metallized layer and the soft metal layer, and the soft metal layer and the lightning arrester are in close contact with each other, so that airtightness and watertightness can be secured and reliability can be improved. Therefore, there is an effect that deterioration of the lightning protection element can be prevented.

[Brief description of drawings]

FIG. 1 is a partial semi-longitudinal sectional view of a lightning protection insulator showing an embodiment of the present invention, FIG. 2 is a schematic front view showing a usage state of the lightning protection insulator, and FIG. 3 is an enlarged sectional view near the upper heat dissipation cover. , 4th
The figure is a cross-sectional view taken along the line AA of FIG. 1, and FIG.
It is a B-line reduced sectional view. 5 ... Insulator main body, 5a ... Shade part, 5c ... Head part, 7 ... Cap fitting, 8 ... Pin fitting, 9 ... Insulating support tube, 9a ... Annular groove, 10 ...
Metallized layer, 11 ... Lightning protection element, 13 ... Protective plate for conduction, 14 ...
Soft metal layers, 15, 16 ... Electrodes, 17 ... Pressure springs.

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Claims (5)

[Claims] 1. A cap metal fitting (7) is capped and fixed to a capped tubular head (5c) formed in the upper central part of a cap portion (5a), and a pin metal fitting (8) is provided inside the head (5c). ) Is inserted and fixed to form an insulator body (5), and an insulating support tube (9) is attached to the cap portion (5a).
Are projected vertically, and a lightning arrester element (11) having a non-linear voltage-current characteristic is embedded in the insulating support tube (9). Copper sulfide method is applied to both upper and lower end surfaces of the insulating support tube (9). A metallized layer (10) with high adhesion to porcelain is applied by the silver carbonate method, etc., and a metallized layer (23) is also provided on the end face of the lightning protection element (11) by another method. The surface is covered with a soft metal layer (14) such as solder or a low-melting metal braze to form an airtight layer, and the upper and lower ends of the insulating support tube (9) are electrically connected to the lightning protection element (11). A lightning protection insulator characterized in that both upper and lower electrodes (15, 16) in a cap shape connected to the are caulked. 2. The upper and lower electrodes (15, 16) are pressed by a pressing spring (17) having an energizing function interposed between the inner surface of the upper and lower electrodes (15, 16) and the insulating support cylinder (9). ) The lightning protection insulator according to claim 1, wherein the lightning protection insulator is caulked in annular grooves (9a) provided on the upper and lower outer circumferences of the above. 3. The solder of the soft metal layer (14) has a melting point of 150 to 250.
The lightning protection insulator according to claim 1, which has a temperature of about ° C. 4. The lightning protection insulator according to claim 2, wherein a metal protective plate (13) for conduction is interposed between the lightning protection element (11) and the pressing spring (17). 5. The lightning arrester according to claim 1, wherein a rubber-like adhesive elastic body (20) is enclosed in a space inside both the upper and lower electrodes (15, 16).