JPH0630287B2 - Gears press arrester - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a gears press arrester, and more particularly to a gears press arrester capable of easily determining an airtight state.

[Technical Background of the Invention and Problems Thereof] A lightning arrester has a lightning arrester element housed in a container having excellent weather resistance such as a porcelain tube, and sealed with dry nitrogen or air as an insulating medium so that it is completely exposed to the outside air. It has a broken airtight structure. If there is a defect in this airtight structure, moisture in the outside air will penetrate into the interior, impairing the insulation performance of the arrester element, degrading the function of the arrester, and eventually causing a burnout due to dielectric breakdown. Conventionally, the entire product for judging the quality of the airtight structure portion is put in hot water to increase the pressure in the airtight structure, and it is checked whether or not there is airtightness by the presence or absence of bubbles. However, it requires skill to determine the airtight leak, and the accuracy of the airtightness determination is limited.

In another conventional example, a method has been proposed in which a lightning arrester is held in a pressurized inert gas tank for a certain period of time and then the discharge voltage of a built-in gear is checked to determine whether the airtight state is good or not. (Japanese Patent Application No. 56-78601) However, this method cannot be applied to a gear-press press lightning arrester which has been widely used in recent years and which uses a zinc oxide element having excellent non-linear resistance characteristics as a characteristic element. Therefore, the emergence of a gear press arrester which can easily determine the airtight state of the arrester has been desired.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a gear press press lightning arrester capable of easily performing airtight leak determination.

[Outline of Invention]

In order to achieve the above-mentioned object, the gears press arrester according to the present invention has a non-linear resistor, a pair of fixed and movable electrodes connected in series with the non-linear resistor, and holds the electrodes in a normally closed state. An elastic body and a porcelain insulator are housed in an airtight state, and the movable electrode is formed of a magnetic material that is movable against the elastic body by an electromagnetic force from the outside of the porcelain insulator, and an electromagnetic force from the outside of the porcelain insulator is used. Thus, the electrode is opened to enable an airtight test.

Example of Invention

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

FIG. 1 is a vertical sectional view of a lightning arrester according to an embodiment of the present invention. An insulating tube 2 and a non-linear resistor 3 are stacked inside a porcelain porcelain insulator tube 1, and a contact pressure is applied downward by a first spring 4. On the upper end surface of the porcelain bushing 1, the line side terminal 5 is tightened with a bolt 7 by sandwiching the contact plate 6, and the upper packing 8 accommodated in the packing groove provided in the line side terminal 5 is compressed to perform an airtight action. There is. The lower end surface of the porcelain bushing 1 has a lower packing 10 accommodated in a cover 9 having a packing groove, and the cover 9 is fixed to the porcelain bushing 1 by drawing so that the lower packing 10 is compressed to perform an airtight action. A fixed test electrode is placed between the non-linear resistor 3 and the insulating tube 2.
11 is sandwiched, and the movable test electrode 12 is pressed against the fixed test electrode 11 by the second spring 13. In this way, always
Between the line-side terminal 5 and the cover 9, only the non-linear resistor 3 has a structure without any gear gap.

Next, a method of airtightness test of the gear press arrester constructed as above will be described.

Gas tank filled with inert gas such as SF ₆ or Freon that is pressurized with the lightning arrester after assembly (not shown)
After leaving it inside for a certain period of time, take it out to the atmosphere and conduct an electrical test.

FIG. 2 shows a diagram during an electrical test. The arrester is placed on the electromagnetic magnet 14 to excite the electromagnetic magnet 14. If the movable test electrode 12 is made of a magnetic material such as iron, the movable test electrode 12 is attracted downward by the electromagnetic magnet 14 so that the absorption force becomes greater than the repulsive force of the second spring 13 by the magnet. For example, the movable test electrode 13 is pressed against the cover 9, and a test gear 15 is formed between the fixed movable test electrodes 11 and 12. In this state, check the discharge voltage of the test gear 15. If there is a defect in the lightning arrester's airtight structure, the inert gas has entered the lightning arrester while being left in the pressurized gas tank, and the discharge voltage of the test gear 15 will be higher than in the normal case. Can be easily detected. In this test, a lightning arrester that does not discharge even when a constant voltage is applied can be determined to be acceptable.

After completion of the electric test, the magnet 14 is deenergized, and the movable test electrode 12 is pressed against the fixed test electrode 11 again by the restoring force of the second spring 13 to form the gear press arrester structure.

〔The invention's effect〕

As described above, the gear press arrester according to the present invention can easily determine the airtight state as follows.

1) If a large pressurized gas tank is used, a large amount of lightning arresters can be stored at one time, so it is possible to easily perform an airtight test on mass-produced devices such as distribution lightning arresters.

2) Since the discharge voltage of the test gear changes greatly even when a very small amount of inert gas is mixed in, the accuracy of detecting airtightness is extremely high. Moreover, no skill is required to determine the airtight leak, and the reliability of the test is high.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a gears press arrester according to the present invention in a steady state, and FIG. 2 is a view showing a state in an electric test of an embodiment of a gears press arrester according to the present invention. 1 …… Insulator tube 2 …… Insulation tube 3 …… Non-linear resistor 11 …… Fixed test electrode 12 …… Movable test electrode 14 …… Electromagnetic magnet

Claims (2)

[Claims] 1. A non-linear resistor, a pair of fixed and movable electrodes connected in series to the non-linear resistor, and an elastic body for holding both electrodes in a normally closed state in an insulator tube in an airtight state. And a movable body made of a magnetic material which is movable against the elastic body by an electromagnetic force from the outside of the porcelain bushing. 2. The gear suppress arrester according to claim 1, wherein the elastic body is a compression spring.