JP2724057B2 - Lightning arrester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester used for distribution lines and the like.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a conventional lightning arrester disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 2-33404. The electric wire 7 is connected to power-supply-side fittings 6a and 6b on the upper part of the insulating container 2, and their charged portions are covered with insulator covers 10a and 10b. Here, the zinc oxide element 1 is located in the lower space 11 provided in the insulating container 2.
And is connected to the power-receiving-side fitting 6b via the conductor 3. The lower space 11 is hermetically closed by a lid 9 electrically connected to the ground-side fitting 4 by a connection line 14, and a gas such as air or nitrogen is sealed inside.

[0003] For example, when the zinc oxide element 1 fails, an internal arc 12 is generated, the internal gas in the closed lower space 11 is heated, and the pressure in the space increases. In order to prevent the insulating container 2 from being violently broken and scattered due to this pressure rise, the lid 9 is automatically broken when the pressure rises beyond a certain limit, and releases internal gas. That is, the lid 9 has a pressure release function like a safety valve.

[0004]

As described above, it is not possible for the insulating container 2 to be broken due to the pressure increase in the lower space 11 as described above.
However, the internal arc 12 remains after the internal gas is released, and the heat generated by the internal arc 12 causes the insulating container 2 to be heated and destroyed. .

The present invention has been made to solve the above-mentioned problems. When an arc is generated inside the insulating container 2 due to a failure of a zinc oxide element or the like of a lightning arrester, the internal pressure is increased and the heating is caused by the arc. It is an object of the present invention to obtain a lightning arrester that does not damage the insulating container 2.

[0006]

According to a first aspect of the present invention, there is provided a lightning arrester including an insulating container provided with a space therein, a zinc oxide element accommodated in an upper portion of the space in the insulating container, and the zinc oxide. A lid attached to the upper end of the insulating container so as to be able to come off when the pressure in the space is increased in order to seal the space accommodating the elements, a ground-side fitting provided at the lower end of the insulating container, and the lid are provided. wherein a voltage application side bracket provided in the upper part of the insulating container, gas is released to the outside from the voltage application side fitting space constituted between the upper end portion of said insulating container and the Division conductive mounting bracket One having a nozzle-shaped outlet for controlling the direction of time substantially in the direction of the ground-side metal fitting, and covering the power-receiving-side metal fitting so that the space inside the power-receiving-side metal fitting is substantially sealed. And the jets provided on the power-supply-side bracket. Covering the mouth, part of the Division conductive side of the Division conductive mounting bracket with the gas pressure within the Division conductive metal fitting space permits the rapidly increased release of gas to the outside of the case
An insulating cover having an easily breakable portion configured to be exposed to the outside of the inner space of the fitting .

[0007] The insulating container lightning arrester having a space therein in accordance with the invention described in claim 2, the space of the insulating container
A zinc oxide element housed at the top, a lid attached to the upper end of the insulating container so as to be able to come off when the pressure in the space is increased in order to seal the space housing the zinc oxide element,
Said ground side metal fitting provided at the lower end of the insulating container, a voltage application side bracket provided in the upper part of the insulating container in which the lid is provided <br/>, of the insulating container and the Division conductive mounting bracket A horn fitting provided outwardly in the vicinity of the ejection opening of the power-receiving-side fitting, the horn fitting having an ejection port for discharging gas from the space inside the electricity-supplying-side fitting formed between the upper end portion and the outside, In order to substantially seal the space inside the power-receiving-side fitting, the power-receiving-side fitting is covered, and the entire horn fitting provided on the power-receiving-side fitting is adapted to correspond to the shape of the horn fitting. br /> cover, the Ho with the gas pressure within the Division conductive metal fitting space permits the rapidly increased release of gas to the outside of the case
The frangible portion for exposing the metal portion of the down bracket to the outside small
At least a part of the insulating cover.

[0008]

According to the lightning arrester of the first aspect, the heat of the internal arc generated in the space accommodating the zinc oxide element in the insulating container due to the failure of the zinc oxide element or the like causes the gas in the space to heat and expand, The lid provided to seal the space is automatically torn. Therefore, the gas that has been heated and expanded fills the space inside the power-receiving-side fitting, and rapidly increases the gas pressure in the space inside the power-receiving-side fitting. As a result, the frangible portion of the insulating cover that substantially seals the inner space of the power-receiving-side metal fitting is opened to cover the spout provided on the power-receiving-side metal fitting, and the gas is transferred to the ground-side metal fitting in the external space. Release in the direction of.

According to the lightning arrester of the second aspect, the heat of the internal arc generated in the space accommodating the zinc oxide element in the insulating container due to the failure of the zinc oxide element or the like causes the gas in the space to expand by heating. The lid provided to seal the space is automatically torn. Therefore, the gas that has been heated and expanded fills the space inside the power-receiving-side fitting, and rapidly increases the gas pressure in the space inside the power-receiving-side fitting. As a result, at least a portion of the portion of the insulating cover that covers the horn fitting, which covers the horn fitting provided in the vicinity of the ejection opening of the power receiving fitting and substantially seals the space inside the power receiving fitting. The gas is discharged along the horn fitting in the external space in the direction of the ground-side fitting.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a lightning arrester according to a first embodiment of the present invention. A power-receiving-side metal fitting 6b is attached to the upper portion of the insulating container 2 with cement 8a, and the electric wire 7 is connected and fixed by the power-receiving-side metal fittings 6a and 6b.
These electric wires 7 and power-receiving-side fittings 6a, 6b are made of polyethylene resin or EP (ethylene propylene rubber) of about 3 mm.
It is covered with thick insulator covers 10a and 10b.
The power-supply-side bracket is formed by the insulator covers 10a and 10b.
Prevent electric shock accident by covering 6a, 6b
Can be. The insulator covers 10a and 10b are covered on the upper portions of the power-receiving-side fittings 6a and 6b with the hinge 10c as a fulcrum, and are opened from the center to the left and right in the figure. The insulator covers 10a and 10b are connected together and attached as shown in FIG.

The power-receiving-side metal fitting 6b is shaped like a lid so as to form a power-receiving-side metal-fitting space 20 above the insulating container 2, and is formed between the power-receiving-side metal-fitting space 20 and the surrounding atmosphere. The space is communicated by the spout 15 if the insulator cover 10a is not provided.
Actually, the spout 15 is also covered with the insulator cover 10a, and the power-supply-side inner space 20 is substantially sealed. This substantially sealed means that when the pressure in the power-supply-side fitting internal space 20 instantaneously rises to several times or more of the atmospheric pressure, it is sealed so that the increased pressure does not drop instantaneously. It means that.

A zinc oxide element 1 is accommodated in an upper space 11 設 け provided in an insulating container 2, and is connected to a ground-side fitting 4 via a conductor 3. The upper space 11 ■ is connected to the power-supply-side fitting 6b and the connection line 14.
The inside is hermetically sealed by a lid 9 ■ electrically connected by (2), and the inside is sealed with an internal gas such as air at atmospheric pressure or nitrogen. The grounding-side fitting 4 is attached to the lower part of the insulating container 2 by cement 8b. The ground side bracket 4 is pin 401
Is attached to the pole arm 5 of the telephone pole.

The shape of the ejection port 15 described above is such that when a gas is released as described later, the nozzle is directed downward in the figure so that the released gas is directed substantially toward the ground-side fitting 4. It has a shape. In order to substantially seal the inner space 20 of the power-receiving-side fitting, the resin-made insulator covers 10a and 10b are almost in close contact with the lower peripheral edge 6b # of the power-receiving-side fitting 6b. Here, the thickness of the easily breakable portion 10d that covers the nozzle portion of the jet port 15 of the insulator cover 10a is formed as thin as about 0.5 mm.

For example, when the zinc oxide element 1 fails, an internal arc 12 is generated, the internal gas in the closed upper space 11 is heated, and the pressure in the space increases to 10 to 20 atm.
In order to prevent the insulation container 2 from being destroyed by this pressure rise, the lid 9 ■ is automatically torn when the pressure rises beyond a certain limit, and the internal gas inside the power-supply-side fitting inner space 20 is closed.
Release into. The gas released into the power-receiving-side bracket internal space 20 is covered by the insulator cover 10a that covers the ejection port 15 of the power-receiving-side bracket 6.
And is instantaneously released to the outside as shown by arrows A and A in the figure. As a result, there is no possibility that the insulating container 2 may be damaged due to a rise in the pressure of the internal gas.

As described above, the easily breakable portion 1 of the insulator cover 10a
Since 0d is broken, a part of the power-receiving-side fitting 6b is exposed to the atmosphere. Further, since a gas containing a large amount of ions ionized due to the generation of the internal arc 12 is emitted as shown by arrows A and A, a part of the exposed metal fitting 6b and the ground which is originally exposed These ionized gases exist between the side fittings 4. Therefore, the power-supply-side bracket 6b and the ground-side bracket
Flashing occurs because the insulation between the four is greatly reduced, and an external arc 16 is generated, with the result that the internal arc 12 is extinguished.
Unlike the internal arc 12 generated in a narrow space in the insulating container 2, the external arc 16 is generated in a wide atmosphere as shown in the figure, and therefore does not heat the insulating container 2. That is, the internal arc 12 is extinguished and the external arc 16 is generated, thereby preventing the insulating container 2 from being damaged by heating.

In the above-described first embodiment, the thickness of the easily breakable portion 10d of the insulator cover 10a is made thin so that the portion can be broken by an increase in the pressure of the internal gas. That is, when the pressure in the power-receiving-side fitting internal space 20 rises sharply, the easily-breakable lid 10d that allows the gas in the power-receiving-side fitting internal space 20 to be released to the outside is provided. The function that the easily breakable portion 10d of the insulator cover 10a is substantially opened is, for example, the function of the easily breakable portion 1d of the insulator cover 10a.
0d is cut along the periphery of the spout 15 to make it easy to break, or this easily breakable part
It can also be obtained by providing the door 10d with a door which can be easily opened by an increase in internal pressure or a stopper which can be easily removed by an increase in internal pressure.

FIG. 2 is a sectional view showing a lightning arrester according to a second embodiment of the present invention. The lightning arrester shown in FIG. 2 is substantially the same as the lightning arrester shown in FIG. It is connected to the side fitting 4 by welding or the like. This power-side horn 17a
The insulating cover 10a also has a horn-shaped portion 10h as shown in FIG. 2 so as to cover the entire charging section including the power-supplying horn 17a. As above
With the insulating covers 10a and 10b and the horn-shaped portion 10h
Cover the power-receiving-side fittings 6a and 6b and the power-receiving-side horn 17a.
Thus, an electric shock accident can be prevented.

When an internal arc 12 is generated due to the failure of the zinc oxide element 1 in the lightning arrester shown in FIG. 2, the internal gas released from the lid 9 ■ passes through the jet port 15 、 and the horn shape of the insulating cover 10 is formed. It is guided to the portion 10h and breaks its tip or the entire horn-shaped portion 10h, and is discharged in the direction of the horn 17b along the power receiving horn 17a as shown by arrows B and B. As a result, the provision of the power-supplying horn 17a and the grounding-side horn 17b results in a shorter insulation distance between metal fittings than when the horn is not connected to the power-supplying-side metal fitting 6b or the grounding-side metal 17b. As shown by arrows B and B, the external arc 16 can be more easily produced as compared with the first embodiment due to the synergistic effect of the internal gas discharged concentrated between the power receiving horn 17a and the ground horn 17b. Occurs. Therefore, damage to the insulating container 2 due to heating can be prevented more reliably than in the first embodiment.

It is to be noted that the tip of the horn-shaped portion 10h may be thinned by forming the tip of the horn-shaped portion of the insulating cover 10 to be thin, or the root portion of the horn-shaped portion 10h may be thinned.
The root is torn. That is, at least a part of the horn-shaped portion 10h has an easily breakable portion that allows the internal gas to be released to the outside. The specific configuration example of the easily breakable portion having the function of substantially opening the opening is as described in the first embodiment.

In the above-described second embodiment, the horn 17 on the charging side is used.
Since the nozzle 15a is provided, the jet port 15 # does not need to have the nozzle shape as in the first embodiment. As described above, the embodiment having the two horns, the power-supplying horn 17a and the grounding-side horn 17b, has been described. However, when one of the horns is used, or when the jet port has the nozzle shape of the first embodiment. Almost the same effects can be obtained by combining the ground horn 17b with the ground horn 17b.

In the above embodiment, an example is shown in which the direction of opening of the jet ports 15 and 15 ° is perpendicular to the electric wire 7.
However, in consideration of actual use, a lightning protection device is provided for each of a plurality of wires that are installed in parallel, so that it is possible to avoid the influence of the ionized gas released between adjacent wires. Generally preferred. In that case, it is possible to cope with this by shifting the positions of the jet ports 15, 15 ° so that the directions of the jet ports 15 and 15 ° are parallel to the electric wire 7.

[0022]

According to the lightning arrester of the first aspect, as a result of a sudden increase in gas pressure in the space inside the power-receiving side metal fitting due to the generation of an internal arc, the space inside the power-receiving side metal fitting is substantially sealed. An easy-to-break portion of the insulating cover covering the spout provided on the power-receiving-side fitting is opened, and the ionized gas is discharged in the external space toward the ground-side fitting. As a result, the insulation between a part of the power application-side metal fitting and the ground-side metal fitting that is exposed due to the opening of the above-described ejection port is reduced, and an external arc is generated. As a result, the internal arc is extinguished, so that the insulating cover is not heated and destroyed by the internal arc. Also, the metal fittings on the power
It is covered with a bar, so you can prevent electric shock accidents
You.

According to the lightning arrester of the second aspect, the horn provided in the vicinity of the ejection port of the power-receiving-side fitting as a result of a sharp rise in the gas pressure in the internal space of the power-receiving-side fitting due to the occurrence of an internal arc. A frangible portion of at least a portion of the insulating cover that covers the metal fitting and substantially seals the inner space of the power-receiving-side metal fitting is open at least in a portion of the insulating cover that covers the horn metal fitting, and the ionized gas flows along the horn metal fitting. In the direction of the ground-side fitting in the external space. Therefore, the insulation between the horn fitting and the ground-side fitting that is exposed due to the opening of the easily breakable portion of the insulating cover described above decreases, and an external arc is generated. As a result, the internal arc is extinguished, so that the insulating cover is not heated and destroyed by the internal arc. In addition, the power supply side bracket and horn bracket
Each is covered with an insulating cover and a horn-shaped part
Thus, an electric shock accident can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a lightning arrester according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of a lightning arrester according to the present invention.

FIG. 3 is a sectional view showing a conventional lightning arrester.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Zinc oxide element 2 Insulating container 4 Grounding side fitting 6a, 6b Power receiving side fitting 9 ■ Lid 10a, 10b Insulating cover 10d Fragile break 10h Horn shaped part 11 ■ Upper space 15,15 ■ Spout 17a Horn fitting 20 Power receiving Space in side bracket

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasutomo Imai 2-4-1, Nishi-Atsujigaoka, Chofu City Tokyo Electric Power Company R & D Laboratory (72) Inventor Tatsuyoshi Matsuura 2-4-1, Nishi-Atsujigaoka, Chofu City Tokyo Electric Power Company (56) References JP-A-59-182501 (JP, A) JP-A-48-4945 (JP, A) JP-A 62-62408 (JP, U) JP-A-2-33403 ( JP, U) Japanese Utility Model Showa 63-167702 (JP, U)

Claims (2)

(57) [Claims] 1. A dielectric casing having a space therein, the zinc oxide element housed in the space above the insulating container, the space at the upper end of the insulating container for sealing the space containing the said zinc oxide elements the lid mounted as may come off when the inner pressure has increased, the ground side metal fitting provided at the lower end of the insulating container, a voltage application side bracket provided in the upper part of the insulating container in which the lid is provided A nozzle for controlling a direction in which gas is discharged to the outside from a space inside the power-supplying-side fitting formed between the power-supplying-side fitting and an upper end of the insulating container, substantially in the direction of the ground-side fitting. What has a shape of the ejection port, so that the space inside the power application side metal fitting is substantially sealed, and covers the power application side metal fitting, and covers the jet port provided in the power application side metal fitting, Gas pressure in the space inside the power-supply-side bracket suddenly increases The Division conductive portion of the mounting bracket is the Division conductive mounting bracket in conjunction with permitting the release of the external gas when raised
A lightning arrester comprising: an insulating cover having an easily breakable portion configured to be exposed to the outside of the space . Wherein the insulating container having a space therein, the zinc oxide element housed in the space above the insulating container, the space at the upper end of the insulating container for sealing the space containing the said zinc oxide elements the lid mounted as may come off when the inner pressure has increased, the ground side metal fitting provided at the lower end of the insulating container, a voltage application side bracket provided in the upper part of the insulating container in which the lid is provided A spout for discharging gas from a space inside the power-supplying-side fitting formed between the power-supplying-side fitting and an upper end portion of the insulating container, near the ejection port of the power-supplying-side fitting. A horn fitting provided to the outside, the horn fitting provided on the power-receiving-side fitting as a whole , while covering the power-receiving-side fitting such that the space inside the power-receiving-side fitting is substantially sealed. To the shape of the horn bracket
To as cover, when the gas pressure within the Division conductive metal fitting space is rapidly increased when allowing the release of the external gas co
A lightning arrester comprising: an insulating cover having, at least in part, an easily breakable portion for exposing a metal part of the horn metal part to the outside .