JP2001237110A - Surge arrester - Google Patents

Abstract

(57) [Problem] To improve the surge current resistance and energy resistance of a surge arrester that protects various electronic devices and electrical equipment from noise such as lightning and switching surges. SOLUTION: A cylindrical insulator 1, a plurality of voltage non-linear elements 4 having sprayed electrodes formed on both sides laminated and housed inside thereof, a pair of electrode plates 5, and the voltage via the electrode plates 5 are provided. A spring 6 electrically connected to the spray electrode of the non-linear element 4 and pressed against one side;
The conductor 7 was interposed between the stacked voltage non-linear elements 4 in the surge arrester comprising the cap 3 having the terminal 2 in the opening of the lightning arrester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester for protecting various electronic devices and electric equipment from noises such as lightning and switching surges.

[0002]

2. Description of the Related Art The structure of a conventional lightning arrester is shown in FIG. FIG.
1 is a cylindrical insulator, 2 is a terminal, 3 is a cap,
Is a voltage non-linear element, 5 is an electrode plate, and 6 is a spring.

The lightning arrester includes a cap 3 having terminals 2 attached to both openings of a cylindrical insulator 1, a voltage non-linear member electrically connected to one of the terminals 2, and laminated via an electrode plate 5. The voltage non-linearity element 4 has a sprayed aluminum electrode (not shown) formed on both surfaces.

[0004]

However, in the structure of the surge arrester, the sprayed electrode of the voltage non-linear element 4 has a rough surface and the contact surface between the voltage non-linear elements 4 is smaller than the electrode area. The element 4 could not sufficiently exhibit the current withstand capability and the energy withstand capability against the lightning surge or the switching surge.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to improve the surge current resistance and the energy resistance of the surge arrester.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical insulator, a plurality of voltage non-linear elements having thermal spray electrodes formed on both sides stacked and housed therein,
A pair of electrode plates, a spring electrically connected to the thermal spray electrode of the voltage non-linear element through the electrode plates and holding the pressure contact from one side, and a lightning arrester having a terminal formed at an opening of the cylindrical insulator. By interposing a conductor between the stacked voltage non-linear elements and bringing the voltage non-linear elements into contact with each other with an area equal to or greater than the electrode area formed on both sides, lightning surge or switching surge can reduce the voltage non-linear element. When the voltage non-linearity element is added, the inherent performance of the voltage non-linearity element, such as the current resistance and the energy resistance, is sufficiently exhibited to achieve the intended purpose.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention is directed to a cylindrical insulator, a plurality of voltage non-linear elements having electrodes formed on both sides laminated and housed therein, and a pair of electrode plates. And a spring electrically connected to the thermal spray electrode of the voltage non-linear element via the electrode plate, and a spring that is pressed and held from one side, and a lightning arrester having a terminal formed in the opening of the cylindrical insulator. A surge arrester with a conductor interposed between voltage non-linear elements, and a sprayed electrode area in which the contact area between voltage non-linear elements is formed on both sides by interposing a conductor between stacked voltage non-linear elements. When lightning surge or switching surge is applied to the voltage non-linear element by making it equal to or larger than the above, the original performance of the voltage non-linear element such as current capacity and energy capacity can be fully exhibited. Those having an effect of bets can be.

The invention according to claim 2 of the present invention is the surge arrester according to claim 1, wherein the conductor is a silver paste, wherein a silver paste is interposed between the stacked voltage non-linear elements as a conductor. As a result, the unevenness of the spray electrode formed on the surface of the voltage non-linear element is filled with silver paste, and the contact area between the voltage non-linear elements can be made equal to or greater than the area of the spray electrode that forms the lightning surge. Alternatively, when an opening / closing surge is applied to the voltage non-linear element, the voltage non-linear element has an effect of sufficiently exhibiting its inherent current withstand capability and energy withstand capability.

According to a third aspect of the present invention, there is provided the surge arrester according to the first aspect, wherein the conductor is a thermosetting conductive adhesive, and the conductor is provided between the laminated voltage non-linear elements. By interposing a thermosetting conductive adhesive, the thermosetting conductive adhesive fills the unevenness of the sprayed electrode formed on the surface of the voltage non-linear element and forms a contact area between the voltage non-linear elements. It is possible to increase the area equivalent to or larger than the sprayed electrode area, and when a lightning surge or switching surge is applied to the voltage non-linear element, the performance of the voltage non-linear element such as the original current capacity and energy capacity Can be sufficiently exhibited, and the voltage non-linear elements can be fixedly held together.

According to a fourth aspect of the present invention, there is provided the surge arrester according to the first aspect, wherein the conductor is a conductive rubber having elasticity. By interposing conductive rubber having, by pressing with a spring from one of the laminated voltage non-linear elements,
The conductive rubber with elasticity fills the unevenness of the thermal spray electrode formed on the voltage non-linear element surface, and it is possible to make the contact area between the voltage non-linear elements equal to or larger than the thermal spray electrode area formed. When a lightning surge or a switching surge is applied to the voltage non-linear element, the voltage non-linear element has an effect of sufficiently exhibiting the inherent current withstand capability and energy withstand capability of the voltage non-linear element. .

According to a fifth aspect of the present invention, there is provided the lightning arrester according to the first aspect, wherein a conductor and a metal plate excellent in heat dissipation are interposed between the stacked voltage non-linear elements. By interposing a conductor and a metal plate with excellent heat dissipation between the voltage non-linear elements, the conductor increases the contact area between the voltage non-linear elements equal to or greater than the area of the sprayed electrode that forms When a lightning surge or switching surge is applied to the voltage non-linear element, the heat generated by the voltage non-linear element is radiated to the outside, and the temperature rise of the voltage non-linear element is alleviated to reduce the voltage non-linearity. It also has the effect that the performance of the linear element, such as the original current withstand capability and the energy withstand capability, can be further improved.

The arrester of the present invention will be described below.

The structure of the arrester of the present invention is shown in FIGS. 1 to 4, reference numeral 7 denotes a conductor, 8 denotes a heat radiator, and other components are the same as those in the conventional example.

First, 87.9 mol% of zinc oxide, 5.3 mol% of bismuth oxide and 0.9 mol of cobalt oxide were used as starting materials.
Mol%, nickel oxide 0.9 mol%, antimony oxide 3.3 mol%, manganese oxide 0.5 mol%, silicon oxide 0.3 mol%, and aluminum hydroxide 0.02 mol%. 32mm diameter, 31 thickness using ceramic method
A sintered body of the zinc oxide-based voltage nonlinear element 4 having a thickness of 2 mm is manufactured.

Next, both surfaces of the sintered body were polished to a diameter of 32 m.
m, thickness 31mm, then polished both sides 30m diameter
The voltage non-linearity element 4 is completed by spraying the aluminum electrode 10 of m.

Next, an inner diameter of 34 mm and a length of 1 shown in FIG.
A stainless steel cap 3 having a terminal 2 is connected to one opening of a cylindrical insulator 1 of 13 mm.

Then, after the copper electrode plate 5, three voltage non-linear elements 4, the electrode plate 5, and the stainless steel spring 6 are sequentially inserted into the cylindrical insulator 1, the other end of the cylindrical insulator 1 is inserted. The coupling was carried out in a state where the spring 6 was compressed by the cap 3 having the terminal 2 in the opening of. Note that an element having a conductor 7 interposed between the three voltage non-linear elements 4 was used. Four types of lightning arresters were completed using three types of materials for the conductor 7. Sample (1): Three pastes of voltage non-linear elements 4 were integrated by applying a silver paste to the adjacent sprayed electrode surfaces and dried, Sample (2): Conductive thermosetting resin was applied to the adjacent sprayed electrode surfaces A sample in which three of the voltage non-linear elements 4 are integrated by coating and drying, sample (3): a conductive rubber is inserted into the adjacent spraying electrode surface, and a sample (4): a silver paste is adjacent to the spraying electrode. After applying to the surface and further inserting the heat radiator 8 into the applied surface, it is dried and integrated with the three voltage non-linear elements 4 (FIGS. 3 and 4). Also, the sample of the comparative example (5)
A conventional lightning arrester without using the conductor 7 shown in FIG. 5 was also manufactured.

With respect to the five types of lightning arresters thus manufactured, a surge current resistance test between the terminals 2 was carried out by 8/20 μm.
s, a voltage of 20 kA is applied twice between the terminals 2, and a current of 2 ms, 200 A is applied once between the terminals 2 as an energy withstand test, and the voltage characteristic change rate of the arrester before and after the test is shown in Table 1 The results are shown in Table 2).

Further, with respect to the samples (1) and (5), a voltage of 8/20 μs and 20 kA was applied between the terminals 2 10 times as a surge current withstand test, and 2 m as an energy withstand test.
A critical life test in which a current of s and 200 A was applied between the terminals 2 ten times was performed, and the results are shown in FIGS. 5 and 6, respectively.

[0020]

[Table 1]

[0021]

[Table 2]

As shown in (Table 1) and (Table 2), the surge arresters (1) to (4) according to the present invention all have a surge current withstand test.
It can be seen that the rate of change in both the energy tolerance test is smaller than that of the conventional product (5) and the performance is improved.

This is because the contact area between the voltage non-linear elements 4 is smaller than the formed spray electrode area in the conventional product due to the unevenness of the thermal spray electrode, whereas the present invention product has the adjacent voltage non-linearity. Since the conductor 7 is interposed between the elements 4, the conductor 7 is connected with an area equal to or larger than that of the thermal spray electrode formed by filling the concave and convex portions of the thermal spray electrode. This seems to indicate that the load was uniformly applied to No. 4 and the deterioration of the voltage characteristics was reduced.

The deterioration of the voltage characteristic of the sample (4) is smaller than that of the samples (1) to (3) because the radiator 8 generates heat of the voltage nonlinear element 4 generated when a current or a voltage load is applied. This is probably because the heat was radiated and the temperature rise of the voltage nonlinear element 4 was suppressed. Further, the sample (3) is replaced with the samples (1) and (2).
It is considered that the reason why the voltage characteristic change rate is slightly larger than that of the above is that the depression of the sprayed electrode could not be completely covered.

As shown in FIGS. 5 and 6, even in the limit life test, the conventional product has a tendency of voltage deterioration as the surge voltage or the number of surge current loads increases, while the conventional product has a deterioration tendency. Is small.

From the above results, by placing the conductor 7 between the voltage non-linear elements 4 inserted into the cylindrical insulator 1, the surge voltage or the surge current is applied to the surge arrester. It is clear that the original performance of the non-linear element 4 is fully exploited, and an excellent lightning arrester with high reliability can be obtained.

[0027]

As described above, according to the present invention, the unevenness of the thermal spray electrode formed on the surface of the voltage non-linear element is absorbed by interposing a conductor between the voltage non-linear elements constituting the surge arrester. As a result, the contact area between the voltage non-linear elements becomes equal to or larger than that of the sprayed electrode, and the surge arrester can withstand a surge current or a surge current when a surge current is applied to the surge arrester. Things.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an arrester according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the lightning arrester of the same embodiment;

FIG. 3 is a cross-sectional view of another example of an arrester.

FIG. 4 is an enlarged sectional view of a main part of the same.

FIG. 5 is a graph showing a limit test result for a repeated load of a surge current.

FIG. 6 is a graph showing a limit test result with respect to a repeated load of a surge voltage.

FIG. 7 is a cross-sectional view of a conventional lightning arrester.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical insulator 2 Terminal 3 Cap 4 Voltage non-linear element 5 Electrode plate 6 Spring 7 Conductor 8 Radiator

Claims (5)

[Claims] 1. A cylindrical insulator, a plurality of voltage non-linear elements having sprayed electrodes formed on both sides laminated and housed therein, a pair of electrode plates, and the voltage non-linearity via the electrode plates. A lightning arrester having a spring electrically connected to a thermal spray electrode of an element and pressed and held from one side, and a lightning arrester having a terminal formed in an opening of the cylindrical insulator, wherein a conductor is interposed between stacked voltage non-linear elements. . 2. The lightning arrester according to claim 1, wherein the conductor is a silver paste. 3. The lightning arrester according to claim 1, wherein the conductor is a thermosetting conductive adhesive. 4. The lightning arrester according to claim 1, wherein the conductor is a conductive rubber having elasticity. 5. The lightning arrester according to claim 1, wherein a conductor and a metal plate excellent in heat dissipation are interposed between the stacked voltage non-linear elements.