JPS6328001A - Arrestor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a lightning arrester whose main component is zinc oxide.

B3 Summary of the Invention The present invention provides a surge arrester having a surge arrester body whose main component is zinc oxide, in which the surge arrester is configured by integrally providing pleats made of the same component as the main body on the outer peripheral surface of the surge arrester body, and Y1mA/
By setting mm to So ~ 100Y/xta,
This eliminates the need for a storage insulating container, as well as the need for assembling the support means 1 for supporting the element group within the insulating container and managing airtightness, and improves heat dissipation characteristics.

C1 Conventional technology The structure of the lightning arrester is shown in FIG.

That is, a plurality of element groups 2 made of zinc oxide are stacked inside the porcelain tube l serving as an insulating storage container, and the inside of the porcelain tube 1 is sealed. A pleat Ia is formed on the outer circumferential surface of the insulator tube 1 to increase the creepage distance, and a terminal 5 is inserted into the hole 3 formed in the upper part of the insulator tube 1 via a gasket 4, and a washer 6 is attached to the lower end of the terminal 5. A nut 7 is screwed together via the . - On the other hand, a holding plate 9 having explosion-proof means (not shown) is bolted to the lower part of the insulator I through a gasket 8, and an electrode 11 attached to the holding plate 9 with a distance 10 and a washer 6 via a spring 12. The element group 2 is supported between the electrode 13 and the electrode 13 provided therebetween.

D1 Problems to be Solved by the Invention However, since the element group consisting of zinc oxide elements is housed in an insulating container, there are the following problems.

(a) Since a support means is required to support the element group within the insulating container, there is a problem that the number of parts and assembly steps are increased.

(b) The insulating container must be constructed with an airtight groove, and there is a problem in that it is necessary to control the parts used for the airtight part and to control the airtightness inside the insulating container through an airtight test.

(c) There was a problem in that the heat generated from the element group was trapped in the insulating container, resulting in poor heat dissipation efficiency.

E9 Means for Solving Problems In light of the above, an attempt was made to see if the above problems could be solved by constructing the main body by integrally providing pleats on the outer peripheral surface of the arrester main body.

By the way, as a result of experiments, in the case where pleats of the same composition are integrally provided on the outer circumferential surface of the main body, the integrated lightning arrester main body has the same rated voltage as a conventional arrester and the elements forming the main body. When molded under the same conditions (components and proportions, firing temperature and time), if the body diameter (minimum diameter of the surge arrester body) of the integrated surge arrester body is molded to match the outer diameter of the conventional element, the conventional surge arrester Withstanding voltage (lightning impulse voltage).

It has been found that the length between the electrodes is required to be approximately three times that of the conventional main body, in terms of leakage distance against external contamination (commercial frequency voltage) and external contamination.

In this way, when the length between the electrodes is approximately tripled, the value of V1mA/mm is the same for products molded under the conditions of conventional composition, firing temperature, and firing time, so the value of V1mA/mm is the same, so For example, the starting voltage between the electrodes is proportional to the length, so the voltage value is about three times as large, making it incompatible with conventional lightning arresters and causing a problem of lack of versatility.

Conventionally, the value of V Im A / m m was set at 150 to 3
00 '/ / m m (set based on the lower limit of the operation start voltage of JEC-217), therefore, in order to make it equivalent to the voltage value between the conventional electrodes, Y1m^/
The value of mm must be approximately 1/3, 50 to 100Y/I+1m.

There are methods for reducing Y1mA/m+++, such as (1) changing the blending ratio of components, (2) increasing the firing temperature, and (2) lengthening the firing time.

Therefore, samples were molded under the conditions shown in the table below, and Y1m
^/n+++ was measured experimentally.

The table shows the ingredients and proportions, firing temperature and time.

In addition, in the experiment, outer diameter: 'f:) = 32 mm, length: H =
The test was conducted using a 30 mm disk-shaped sample.

(Margin below) The results are shown in FIG.

From the results in Figure 4, ■ Decrease the blending ratio of sb, o,
■Increase the firing temperature, ■Longen the firing time,
It was confirmed that Y+m^/ll1m can be made smaller by (1) and (2).

It should be noted that it is possible to reduce VH++A/mm with only two of the three conditions (■, ■, and ■) mentioned above, and the combination can be combined in any way, and it is possible to reduce VH++A/mm even with only the - condition. It is.

In this way, the blending ratio of the components in Experimental Examples 1 and 2.3,
Even when the firing temperature and firing time were changed, no changes were observed in other characteristic values such as voltage-current characteristics (V-1 characteristics).

The present invention has been made in view of the above points, and in order to omit the insulating container and have the arrester main body made of zinc oxide serve the external insulation function of the insulating container, the outer peripheral surface of the arrester main body is made of the same material as the main body. By integrally providing folds made of ingredients,
Further, electrodes are provided at both ends of the main body to constitute a lightning arrester, and VHm^/m+n between the electrodes is set to 50 to 100 V/mm.

21 action A plurality of pleats made of the same composition and concentrically arranged in parallel in the axial direction are formed on the outer periphery of a cylindrical lightning arrester body whose main component is zinc oxide, and electrodes are provided at both ends of the arrester body. Installation and V+mA/mm between electrodes from 50 to 100Y/
Since the lightning arrester is configured as mm, there is no need for a storage insulating container, and accordingly, there is no need to assemble the support means 1 for supporting the element group within the insulating container and to manage airtightness.

Moreover, the heat dissipation characteristics can be greatly improved.

G. Examples Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

As shown in FIG. 1, the electric appliance according to the present invention is composed of a lightning arrester body 2I, electrodes 22 fixed to both ends of the lightning arrester body 2I, and wire holders 23 for fixing cables and the like thereto.

The lightning arrester main body 21 is made of a material whose main component is zinc oxide, and is formed by forming a plurality of concentric pleats of the same composition and arranged in parallel in the axial direction on the outer periphery of a cylinder.

As for the material of the lightning arrester body 21, considering the rated voltage, AC withstand voltage, impact withstand voltage, etc., the ingredients and proportions shown in the table above, for example, Experimental Example 1 (94°5 mol% 2n0° 1.0 mol%) are selected.
5btOj, 1.0mol% Bit's, t,o
mol% Co, O, 0,5 mol% MnO, 1,0
Mol% S+Ot.

Using 1.0 mol% of Nio), molding is performed by isostatic pressing or injection molding.

Next, a method for manufacturing such a lightning arrester will be specifically explained.

The manufacturing method (Part 1) for forming the lightning arrester body is shown in Figures 2 (a) and (b). In this process, a material 2 containing zinc oxide as a main component is put into an inner bag L whose inner circumferential surface has been formed in the shape of the earth arrestor body, and the material 2 is placed in a high-pressure container 3 via a diaphragm rubber 4 and a mold bunch 5. Pressure mold. After molding, the pressure inside the high-pressure container 3 is lowered and the hardened lightning arrester main body 2a is taken out.

Next, manufacturing method for lightning protection and molding of the vessel body (Part 2)
are shown in Figures 3(a) and (b). Note that in the drawings, members denoted by the same reference numerals as those in FIG. 2 are the same members, although their shapes are different. Since it is relatively difficult to form pleats on a surge arrester body having a large outer diameter, a substantially cylindrical molded body 6a is made from the material 6 whose main component is zinc oxide by the same method as shown in FIG. The shape of the pleated portion of the body 6a is processed using a grinder or the like to obtain a lightning arrester main body.

The main body of the lightning arrester formed in this way is made by removing organic substances such as binders during the calcination process, and then coating the outer peripheral surface with glaze, glass, and a high-resistance material in a material whose main components are zinc oxide. Reactive oxides (ZntSiO*, ZnxS
byOz) to improve the dielectric strength of the side surfaces. When applying glaze 6, the reaction oxide is applied according to the shrinkage rate due to thermal contraction during calcination of the lightning arrester body, and when glass is applied, it is baked after sintering the lightning arrester body. The temperature and time during firing are based on the firing temperature of 1250° C. and firing time of 20 hours in Experimental Example 1 in the table above.

After firing, both end faces of the lightning arrester main body are polished and baked with silver waves or the like to metallize the surfaces, and then the electrodes 22 are fixed by welding. After that, a wire retainer 23 for fixing a cable or the like is attached to the electrode 22.

As a result of manufacturing the lightning arrester main body according to the present invention to the dimensions shown in FIG. 5 using the ingredients, α ratio, firing temperature and time shown in Experimental Example 1 in the table above, the LHnA/am between the electrodes was measured to be 70 to 8.
It was 0 Y/mm. In addition, in the figure, the maximum diameter D = 50
mm, minimum diameter d = 32 mm, length H = 150 mm.

As described in detail of the H0 invention, according to the present invention, a plurality of pleats made of the same composition and concentrically are arranged in parallel in the axial direction on the outer periphery of the cylindrical arrester body whose main component is zinc oxide. A main body is formed, electrodes are attached to both ends of the arrester main body, and V between the electrodes is
(Since the mA/mm is set at 50 to 100Y/m@, it has the following effects compared to conventional lightning arresters.

(a) A storage insulating container is not required, and a support means for supporting the element group within the insulating container is not required, so the number of parts and assembly man-hours can be reduced.

(b) Management of parts used in airtight parts to create an airtight structure so that an insulated storage container is no longer required.

Also, there is no need to manage the airtightness of the insulating container through airtightness tests.

(c) This occurs because the length between the electrodes is about three times longer.

The ability to absorb heat is improved, and since heat can be directly radiated from the outer peripheral surface of the lightning arrester body, the heat radiation characteristics are improved. Therefore, the heat generated from the element group does not become trapped in the insulating container and the heat dissipation efficiency becomes poor as in the conventional case.

(d) Since the length between the electrodes is increased, the leakage length becomes longer, which improves creeping strength and makes flashover less likely.

[Brief explanation of drawings]

FIG. 1 is a structural diagram showing an embodiment of the lightning arrester according to the present invention, and FIGS.
), FIGS. 3(a) and 3(b) are explanatory diagrams showing the method for manufacturing the lightning arrester main body (Part 2), and FIG.
Figure 5 is an external view of the arrester body, Figure 6 is a graph comparing
The figure is a structural diagram of a conventional lightning arrester. 20... Lightning arrester, 21... Lightning arrester body, 22...
electrode. Figure 5 ■μ body rope sword

Claims (1)

[Claims] On the outer periphery of the cylindrical lightning arrester body whose main component is zinc oxide,
The lightning arrester body is formed by axially arranging a plurality of pleats made of the same component and concentrically, electrodes are attached to both ends of the lightning arrester body, and the V_1m_A/mm between the electrodes is set to 50 to 100V/mm. A lightning arrester characterized by: