JPH0676669A - Lightning insulator - Google Patents

Abstract

PURPOSE:To enhance the corrosion resistance of a lightning insulator by enlarging the diameter of each conducting electrode and to attach lead wire to each conducting electrode without increasing the height of an electrode portion by preventing current density from rising when a lightning surge current is passed. CONSTITUTION:A resistance element 15 of nonlinear voltage-current characteristic is enclosed in a storage cylinder 12 made of porcelain and both ends of the storage cylinder 12 are closed by porcelain lids 21, 22. Conducting electrodes 24, 31 are electrically connected to the resistance element 15 via respective pole plates 19, 20 and are passed through the porcelain lids 21, 22 and supported. Large-diameter head portions 24a, 31a are provided at the outer ends of the respective conducting electrodes 24, 31 and have their inner surfaces brazed to the outer surfaces of the respective porcelain lids 21, 22. Tapped holes 27, 34 for mounting lead wires 29, 35 are formed at the centers of the respective head portions 24a, 31a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection insulator which discharges a lightning surge current to the ground to suppress an increase in the lightning surge potential of a transmission line and prevent a power failure due to a ground fault.

[0002]

2. Description of the Related Art As a conventional lightning protection insulator of this kind, one having a structure as shown in FIGS. 3 and 4, for example, is known.

In these conventional configurations, the resistance element 4 having a non-linear voltage-current characteristic is provided in the porcelain housing cylinder 41.
2 is housed, and a porcelain lid 43 is joined and fixed to both ends of the housing cylinder 41. Electrode plates 44 are provided on both ends of the resistance element 42.
The conducting electrode 45 is electrically connected via the through hole, the conducting electrode 45 penetrates through the insertion hole 46 formed in the porcelain lid 43, and is joined and fixed to the porcelain lid 43 by the silver wax 47. A male screw 48 is formed on the outer periphery of the leading end of the conducting electrode 45, and a lead wire 50 is connected and attached to the conducting electrode 45 by screwing a nut 49 into the male screw 48.

In particular, in the conventional structure shown in FIG. 3, the conducting electrode 45 is formed of a Kovar alloy into a round bar shape having a diameter of about 6 mm, and the porcelain lid 43 surrounds the exposed boundary portion of the conducting electrode 45. An annular electrolytic corrosion prevention ring 51 is provided on the outer surface of the. Further, in the conventional configuration shown in FIG. 4, the conducting electrode 45 has a diameter of 6 mm due to the Kovar alloy.
It is formed in a round bar shape of about mm, and a truncated cone-shaped joint portion 52 is formed at the root portion of the conduction electrode 45.

[0005]

However, in the conventional structure shown in FIG. 3, the conduction electrode 45 is restricted by the joining condition between the outer peripheral surface of the conduction electrode 45 and the inner peripheral surface of the insertion hole 46. The outer diameter of the conductive electrode 45 cannot be increased, and the conductive electrode 45 is formed of a Kovar alloy and fixed to the porcelain lid 43 by the silver wax 47. Therefore, the conductive electrode 45 has poor corrosion resistance. was there.

Therefore, it is necessary to coat the conducting electrode 45 with a material having excellent corrosion resistance such as ceramics or surround the exposed boundary portion of the conducting electrode 45 with the annular electrolytic corrosion preventing ring 51 as described above. there were. Therefore, there has been a problem that the related structure of the conduction electrode 45 is complicated and the manufacturing is troublesome.

Further, in the conventional structure shown in FIG. 3, since the conducting electrode 45 has a small diameter and a small cross-sectional area, the current density of the conducting electrode 45 becomes high during the passage of a lightning surge current, and the electrode plate There is a problem that partial discharge occurs on the contact surface with respect to 44.

In order to deal with this problem, as shown in FIG. 4, a truncated cone-shaped joint 5 is formed at the root of the conductive electrode 45.
Although a configuration in which 2 is provided is also proposed, in the case of such a configuration, it becomes difficult to process the conduction electrode 45 and the fitting tolerance with respect to the insertion hole 46 becomes large, so that the joining state between the two is increased. There was a problem that variation easily occurred.

Further, in the conventional structure shown in FIGS. 3 and 4, since the conducting electrode 45 has a small diameter, it is not possible to form a screw hole for attaching the lead wire at the center of the leading end thereof, and the male electrode is formed on the outer periphery of the leading end. A screw 48 is formed. Therefore, when the nut 49 is screwed to the male screw 48 and the lead wire 50 is connected and attached to the conduction electrode 45, the height of the electrode portion increases, and it is difficult to secure the clearance between the lightning protection insulators. there were.

The present invention has been made by paying attention to the problems existing in such conventional techniques.
It is an object of the invention to provide a lightning protection insulator capable of increasing the diameter of the conducting electrode with a simple structure and improving the corrosion resistance of the conducting electrode.

A second object of the present invention is to make the conducting electrode large in diameter and to have a large cross-sectional area with a simple structure, so that the current density of the conducting electrode can be increased when a lightning surge current is applied. It is an object of the present invention to provide a lightning protection insulator which can prevent the possibility of partial discharge occurring on the contact surface or the like with respect to the electrode plate.

Further, a third object of the present invention is to form a screw hole for attaching a lead wire at the center of the tip of the conducting electrode, thereby making it possible to reduce the height of the electrode portion and to prevent lightning. (EN) Provided is a lightning protection insulator which can secure a sufficient clearance between the insulators.

[0013]

In order to achieve the above object, according to the invention of claim 1, a resistance element having a non-linear voltage-current characteristic is accommodated in a porcelain accommodating cylinder. Both ends of the housing cylinder are closed by a porcelain lid, and a conductive electrode is electrically connected to the resistance element via an electrode plate, and the conductive electrode penetrates and is supported by the porcelain lid. A large-diameter head is provided at the outer end of the conduction electrode, the inner surface of the head is brazed and fixed to the outer surface of the porcelain lid, and a screw hole is formed in the center of the head for attaching the lead wire. It was done.

According to the second aspect of the invention, the conducting electrode is formed of a titanium alloy.

[0015]

[Operation] In the lightning protection insulator configured as described above,
Since a head is provided at the outer end of the conduction electrode and the inner surface of the head is brazed and fixed to the outer surface of the porcelain lid, the fitting tolerance of the conduction electrode to the insertion hole of the porcelain lid, etc. The diameter of the conducting electrode can be increased without any restriction. Therefore, it is not necessary to coat the conductive electrode with a material having excellent corrosion resistance or to surround the exposed boundary portion of the conductive electrode with an annular electrolytic corrosion prevention ring, and improve the corrosion resistance of the conductive electrode with a simple configuration. be able to.

Further, since the diameter of the conducting electrode can be increased, the cross-sectional area of the conducting electrode can be increased with a simple structure without forming a truncated cone-shaped joint or the like at the root of the conducting electrode. Can be taken. Therefore, the current density of the conducting electrode does not increase when the lightning surge current is applied, and it is possible to prevent the possibility of partial discharge occurring at the contact surface or the like with the electrode plate.

Further, since a screw hole for attaching the lead wire is formed at the center of the tip of the conducting electrode, a screw is screwed into the screw hole to increase the height of the electrode portion without increasing the height of the electrode portion. The wires can be connected and attached to the conducting electrodes. Therefore, the height of the electrode portion can be reduced and a sufficient clearance between the lightning protection insulators can be secured, as compared with the conventional configuration in which a male screw is provided on the outer circumference of the tip of the conduction electrode.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a suspension type lightning arrester embodying the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 2, the insulator main body 2 of the lightning protection insulator 1 is integrally formed of porcelain and has a cylindrical head 3 with a lid.
And a cap portion 4 formed on the outer periphery of the head portion 3, and a plurality of concentric fold portions 5 formed concentrically on the inner surface of the cap portion 4. The cap fitting 6 is fitted and fixed to the head 3 of the insulator body 2 via cement 7, and a fitting recess 8 is formed on the top thereof. The pin fitting 9 is fixed in the head 3 of the insulator main body 2 with cement 10, and the fitting portion 11 is attached to the lower end thereof.
Are formed. Then, the fitting portion 1 of the pin fitting 9
By engaging 1 with the fitting recess 8 on the cap fitting 6 of another lightning protection insulator 1, a plurality of lightning protection insulators 1 can be connected in series in the vertical direction.

As shown in FIGS. 1 and 2, the plurality of housing cylinders 12 are formed integrally with the cap portion 4 of the insulator body 2, and inside thereof are a protection cylinder 13 made of alumina or inorganic fibers.
Are arranged. The plurality of resistance elements 15 are housed and arranged in the protective cylinder 13, and are formed of a resistor whose main component is zinc oxide having a non-linear voltage-current characteristic. The pair of intermediate electrodes 16 and 17 is disposed in the intermediate portion of the resistance element 15, and a spring 18 for urging the resistance element 15 toward both upper and lower ends is interposed between the intermediate electrodes 16 and 17. There is.

As shown in FIGS. 1 and 2, a pair of upper and lower electrode plates 19 and 20 made of a conductive material such as Kovar are disposed on the upper and lower end surfaces of the resistance element 15 by bonding, and on the outer surface thereof, a bonding recess 19a is formed. , 20a are formed. The pair of upper and lower porcelain lids 21, 22 are made of an inorganic adhesive 23 such as low melting glass
The adhesive is fixed to the openings at the upper and lower ends of the accommodating cylinder 12 by means of these, and a part of them is bonded to the joint recesses 19 of the electrode plates 19 and 20.
Insertion holes 21a and 22a facing a and 20a are formed. And in this embodiment, the upper porcelain lid 2
The insertion hole 21a of No. 1 has a larger diameter than the insertion hole 22a of the lower porcelain lid 22.

The upper conducting electrode 24 is integrally formed of a conductive material such as titanium, and has a large-diameter head portion 24a at the outer end, a fitting portion 24b in the middle, and a joint portion 24 projecting at the center of the inner surface thereof.
and c. Then, the fitting insertion portion 24b of the upper conducting electrode 24 is fitted into the insertion hole 21a of the upper porcelain lid 21, and the inner surface of the head portion 24a is joined to the outer surface of the upper porcelain lid 21 through the titanium-based wax 25. It is fixed. Also,
The end face of the joint portion 24c is the joint recess 19a of the upper electrode plate 19.
Are joined and fixed via a titanium-based wax material 26. By the way, in this embodiment, the wax materials 25 and 26 are used.
Is titanium 70%, copper 15%, nickel 15% by weight
Is formed of a titanium-based alloy.

As shown in FIGS. 1 to 3, the screw hole 27 is formed at the center of the head portion 24a of the upper conducting electrode 24.
The outer surface of the head 24a is opened. The through hole 28 for gas replacement is formed so as to penetrate the head portion 24a and the fitting insertion portion 24b of the upper conduction electrode 24, and the inner end thereof is located outside the joint portion 24c and outside the peripheral surface of the upper electrode plate 19. It is open. The upper lead wire 29 is connected and fixed to the head portion 24 a of the upper conducting electrode 24 by a screw 30 screwed into the screw hole 27 at one end, and is connected to the cap fitting 6 at the other end. The resistance element 15 and the cap fitting 6 are electrically connected to each other through the upper lead wire 29 and the upper conducting electrode 24.

The lower conducting electrode 31 is integrally formed of a conductive material such as titanium and has a large-diameter head portion 31a at the outer end and a joint portion 31b projecting at the center of the inner surface thereof. Then, the joint portion 31b of the lower conduction electrode 31 is fitted into the insertion hole 22a of the lower porcelain lid 22, and the inner surface of the head portion 31a is joined and fixed to the outer surface of the lower porcelain lid 22 via the titanium-based wax material 32. Has been done. In addition, the end surface of the joint portion 31b is formed in the joint recess 20a of the lower electrode plate 20 by the titanium-based brazing material 3
It is joined and fixed via 3.

The screw hole 34 is formed in the center of the head portion 31a of the lower conduction electrode 31 and is opened on the outer surface side of the head portion 31a. The lower lead wire 35 has a screw hole 3 at one end.
It is connected and fixed to the head portion 31a of the lower conduction electrode 31 by a screw 36 screwed to the screw 4, and the other end is connected to the pin fitting 9. The resistance element 15 and the pin fitting 9 are electrically connected to each other via the lower lead wire 35 and the lower conduction electrode 31.

Next, the operation of the suspension type lightning arrestor constructed as described above will be described. The lightning protection insulator 1 is used by connecting a plurality of lightning protection insulators 1 in series in the vertical direction and supporting a power transmission line at its lower end. When an overvoltage of lightning surge is applied to the power transmission line in this usage state, a lightning surge current flows to the pin metal fitting 9 of the lightning protection insulator 1 located at the lower end, and the lower lead wire 3
5, lower conduction electrode 31, lower electrode plate 20, lower resistance element 15, intermediate electrodes 17, 16, upper resistance element 15, upper electrode plate 19, upper conduction electrode 24, and upper lead wire 2.
It reaches to the cap metal fitting 6 through 9, and then sequentially flows to the grounding side lightning protection insulator 1, and is discharged from the steel tower to the ground. At this time, the resistance element 15 reduces the resistance value due to the non-linear voltage-current characteristic to quickly discharge the lightning surge current, and then immediately restores the resistance value to restore the insulation function to the subsequent operating voltage. To do.

In the lightning protection insulator 1 of this embodiment, the head 2 is attached to the outer ends of the conducting electrodes 24 and 31 as described above.
4a and 31a are provided, and the inner surfaces of the head portions 24a and 31a thereof are joined and fixed to the outer surfaces of the porcelain lids 21 and 22 via the brazing materials 25 and 32. Therefore, the conduction electrodes 24, 3 are not restricted by the fitting tolerance of the conduction electrode 24.31 with respect to the insertion holes 21a, 22a of the porcelain lids 21, 22.
1 can have a large diameter. Therefore, the conduction electrode 2
4,31 is coated with a material with excellent corrosion resistance,
Since it is not necessary to surround the exposed boundary portions of the conduction electrodes 24 and 31 with an annular electrolytic corrosion prevention ring, the corrosion resistance of the conduction electrodes 24 and 31 can be improved with a simple configuration.

Further, in this embodiment, since the conducting electrodes 24, 31 can be made large in diameter, it is possible to form a truncated cone-shaped joint portion or the like at the root of the conducting electrodes 24, 31. The cross-sectional area of the conducting electrodes 24, 31 can be made large with a simple configuration. Therefore, even if a large current of a lightning surge flows through the lightning protection insulator 1 as described above, the current is not concentrated on the conduction electrodes 24 and 31 and the current density does not increase, and the conduction for the electrode plates 19 and 20 is prevented. Electrodes 24,3
It is possible to reliably prevent the possibility of partial discharge from occurring on the contact surface of No. 1 or the like.

Further, in this embodiment, the conducting electrode 2
At the center of the head portions 24a, 31a of the lead wires 4, 31, the lead wire 2
Screw holes 27, 34 for attaching 9, 35 are formed. Therefore, the screw 3 is inserted in the screw holes 27 and 34.
The lead wires 29 and 35 can be connected and fixed to the conductive electrodes 24 and 31 without screwing 0 and 36 and increasing the height of the electrode portions. Therefore, the conducting electrodes 24, 31
Compared with the conventional structure in which a male screw is provided on the outer circumference of the tip, the height of the electrode part can be reduced, and the clearance between the lightning arrestors 1 can be increased in the state where a plurality of lightning arrestors 1 are connected in the vertical direction. You can secure enough.

Moreover, in this embodiment, the conducting electrode 2
4, 31 are made of titanium, and correspondingly, the heads 24a, 31a of the electrodes 24, 31 for conduction are connected to the porcelain lid 21,
The brazing materials 25 and 32 for joining and fixing to the outer surface of 22 are also changed to a titanium base. Therefore, the conductive electrode 2
It is possible to further improve the corrosion resistance of the electrode portion, as compared with the conventional configuration in which a silver-based brazing material is used at the joint portion between the porcelain lids 4 and 31 and the porcelain lids 21 and 22.

The present invention is not limited to the configuration of the above-described embodiment, and for example, the configuration of each part may be arbitrarily modified and embodied within the scope not departing from the gist of the present invention as follows. It is possible. (A) In the invention according to claim 1, the conducting electrode 2
Form 4, 31 with a Kovar alloy, and apply a ceramic coating on it. (B) The upper and lower ends of the protective cylinder 13 should be almost in contact with each other without being embedded in the upper porcelain lid 21 or the lower porcelain lid 22, or arranged with a slight gap.

[0032]

Since the present invention is configured as described above, it has the following excellent effects.

First, according to the invention described in claim 1, the conductive electrode is not coated with a material having excellent corrosion resistance, and the exposed boundary portion of the conductive electrode is not surrounded by an annular electrolytic corrosion preventing ring, and thus it is simple. With such a configuration, the diameter of the conduction electrode can be increased, and the corrosion resistance of the conduction electrode can be improved.

Further, according to the invention described in claim 1, the conduction electrode is made large in diameter with a simple structure without forming a truncated cone-shaped joint at the root of the conduction electrode, and the cross-sectional area thereof is reduced. It can be set large, and it is possible to prevent the possibility that the current density of the conducting electrode becomes high when a lightning surge current is applied and a partial discharge occurs at a contact surface or the like with the electrode plate.

Further, in the invention according to claim 1, a screw hole for attaching a lead wire can be formed in the center of the tip of the conduction electrode, and a conventional structure in which a male screw is provided on the outer periphery of the tip of the conduction electrode. Compared with the above, the height of the electrode portion can be reduced, and a sufficient clearance between the lightning arrestors can be secured.

According to the second aspect of the invention, since the conducting electrode is formed of a titanium-based alloy, the silver wax for bonding and fixing the conducting electrode to the porcelain lid is also changed to a titanium base. Therefore, the corrosion resistance of the electrode portion can be further improved.

[Brief description of drawings]

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

FIG. 2 is a partial cross-sectional view showing the entire structure of the suspension type lightning arrestor.

FIG. 3 is a partial cross-sectional view showing a configuration of a conventional suspension type lightning arrester.

FIG. 4 is a partial cross-sectional view showing another configuration of a conventional suspension type lightning arrester.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lightning protection insulator, 2 ... Insulator main body, 12 ... Housing cylinder, 15 ...
Resistance element, 19 ... Upper electrode plate, 20 ... Lower electrode plate, 21
... Upper porcelain lid, 22 ... Lower porcelain lid, 24 ... Upper conduction electrode, 24a ... Head, 25 ... Silver wax, 27 ... Screw hole, 29 ...
Upper lead wire, 30 ... Screw, 31 ... Lower conduction electrode, 3
1a ... Head, 32 ... Silver wax, 34 ... Screw hole, 35 ... Lower lead wire, 36 ... Screw.

Claims (2)

[Claims] 1. A porcelain containing cylinder contains a resistance element having a non-linear voltage-current characteristic, and both ends of the containing cylinder are closed by a porcelain lid, and the resistance element is provided with an electrode plate. In a lightning arrestor in which a conduction electrode is electrically connected and the conduction electrode is supported through a porcelain lid, a large-diameter head is provided at the outer end of the conduction electrode. A lightning arrester characterized in that the inner surface is brazed and fixed to the outer surface of the porcelain lid, and a screw hole for attaching a lead wire is formed in the center of the head. 2. The lightning protection insulator according to claim 1, wherein the conducting electrode is formed of a titanium alloy.