JPH01620A - lightning insulator - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention provides a method for quickly discharging surge current to the ground when a surge current due to a lightning strike is applied to a power transmission line, and interrupting the subsequent current. This invention relates to a suspended insulator type lightning arrester that prevents ground faults and enables retransmission of power.

(Prior Art) Conventionally, it has been considered to introduce lightning arresters to power transmission lines in order to absorb lightning and switching surges and prevent power transmission line ground faults. However, installing a lightning arrester that only has a lightning protection function on a power transmission line complicates the structure of the transmission line tower and the insulator device, which is undesirable.
A suspended insulator-type lightning arrester has been proposed that has both a wire support function and a lightning arrester function. As this lightning insulator,
The applicant of the present application has proposed an insulator in which a lightning arrester having non-linear voltage-current characteristics is attached to a cylindrical portion of the insulator body. This lightning arrester houses a lightning arrester element in a mounting cylinder, and a metal lower electrode and a lower electrode are fitted and fixed to both the upper and lower ends of the mounting cylinder, and the upper electrode and a cap metal fitting, and the lower electrode and a pin metal fitting are fitted and fixed to the upper and lower ends of the mounting cylinder. They were each connected by lead wires.

(Problem to be solved by the invention) However, in such conventional devices, the metal upper i
Since the rod and the lower electrode are fitted and fixed in the mounting cylinder, there is a problem in that it is difficult to maintain airtightness within the mounting cylinder.

Also, a structure has been proposed in which an insulating ceramic is fitted into the mounting tube and a lead wire is led out from the lightning arrester element, but although this improves the adhesion between the mounting tube and the insulating ceramic, Since it is necessary to form a notch in the insulating ceramic for the lead wire to pass through, not only is the machining troublesome, but the notch is also difficult to seal, posing a problem in reliability.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes fixing a cap fitting to a capped cylindrical head formed at the upper center of the cylindrical portion of the insulator body, A pin fitting is fitted and fixed inside the head, a mounting cylinder is provided in the cylinder, a lightning arrester with non-linear voltage-current characteristics is fitted into the mounting cylinder, and the mounting cylinder is An upper electrode and a lower electrode made of conductive ceramic are fitted into the upper end portion and the lower end portion, and are adhesively fixed to the mounting cylinder portion using an inorganic material.

(Function) In the present invention, since the mounting cylinder part, upper electrode, and lower electrode are molded from conductive ceramic, the mounting cylinder part and the electrodes are securely bonded and fixed, and airtightness is ensured. Deterioration is prevented. In addition, there is no need to form a notch for inserting the lead wire into the electrode.
The structure is cylindrical, improving airtightness and increasing reliability.

(Example) An example embodying the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 3, a large number of suspension insulator-type lightning arresters 3 are connected and suspended in series from a support arm 1 provided on a steel tower (not shown) via hanging fittings 2, and the lowest end of the lightning arrester 3 is A power transmission line is supported via a hanging metal fitting 4.

As shown in FIG. 1, an insulator body 5 constituting the lightning arrester 3
A cylindrical portion 5a, a plurality of folds 5b formed annularly and concentrically on the inner surface of the cylindrical portion 5a, and a covered cylindrical portion integrally formed at the upper center of the cylindrical portion 5a. head 5
It is integrally molded with c. Further, a cap fitting 7 is fixed to the outer periphery of the head 5c with cement 6,
An engagement recess 7a is formed in the metal fitting 7, so that the pin fitting 8 of the lightning arrester 3 directly above the lightning arrester 3 can be engaged with the metal fitting 7.

The upper part of the pin fitting 8 is fixed inside the head 5c with cement 6, and the lower end is engaged with the engaging recess 7a of the cap fitting 7 of the lightning arrester 3 directly below. In this way, a plurality of lightning arresters 3 are connected in series.

As shown in FIGS. 1 and 2, the cylindrical portion 5a has a plurality of cylindrical mounting cylindrical portions 5d (four in this embodiment) arranged at equal intervals and parallel to the pin fitting 8. It is formed to penetrate through the portion 5a.

Each of the mounting cylinders 5d is provided with a plurality of (two in this embodiment) lightning arrester elements each made of zinc oxide (ZnO) as a main material and having a cylindrical shape with excellent follow-on current blocking characteristics and non-linear voltage-current characteristics. 9 are fitted in series, and a silicone rubber 1 serving as an elastic insulating material is inserted between the inner circumferential surface of the mounting cylinder portion 5d and the outer circumferential surface of the lightning arrester element 9.
0 is interposed and glued.

The upper and lower ends of the mounting tube 5d are made of conductive ceramic (ZrBb 2: melting point: 3060°, coefficient of thermal expansion: 4.5×10, specific resistance: 2.5×10 Ω·1) or titanium boride (Ti), which is weather resistant for outdoor use.
・B2: Melting point 2900℃, thermal expansion coefficient 4゜5X10
The upper electrode 11 is made of a conductive material with a high melting point, such as a conductive ceramic having a specific resistance of 2 to 3×10 Ω·Cm).
12 are fitted and fixed by adhesive with a low melting point glass 13 which melts at 300 to 500°C. This low melting point glass 13 is used to reduce the exposed area to the atmosphere, for example,
．． A thickness of 3 to 1°0III is desirable. The low melting point glass 13 and the upper electrode 11. The lower electrode 12 improves the airtightness within the mounting tube 5d, and the lightning arrester element 9
It is designed to prevent deterioration due to moisture.

Furthermore, between the lightning arrester element 9 and the picture electrode 11.12,
A conductive disc spring 14 in the shape of a planar donut plate is interposed to electrically connect the lightning arrester element 9 to the upper electrode 11 and the lower electrode 12, and to mechanically hold the lightning arrester element 9.

Thin electrode layers 15 made of tin metallicon or adhesive conductive paint are formed on both upper and lower surfaces of the lightning arrester 9 to ensure continuity between the disc spring 14 and the lightning arrester 9 and to maintain continuity between the disc spring 14 and the lightning arrester 9.
We are trying to establish continuity between them.

One end of lead wires 17 and 18 is adhesively fixed to the upper surface of the upper electrode 11 and the lower surface of the lower electrode 12 using tin metallized silicone 16, respectively, and the other end of the upper lead wire 17 is connected to the cap fitting 7. Lead wire 18. The other end is connected to the pin fitting 8.

Here, the lightning arrester 9, upper and lower electrodes 11.1
The second assembly process will be explained. First, the lower electrode 12 is fitted to the lower end of the hollow mounting cylinder part 5d, and the lower electrode 12 is melted and solidified at about 500°C with the low melting point glass 13 interposed between the two members. The lower electrode 12 is airtightly fixed to.

Next, the lower disc spring 14 is placed on the upper surface of the lower electrode 12, and the lightning arrester element 9 is placed on the upper surface of the mounting disc spring 14 and held in a predetermined position by a jig (as shown). , silicone rubber 10 is filled between the mounting tube 5d and the lightning arrester 9.
It solidifies and fixes the lightning arrester element 9 to the mounting tube portion 5d.

Furthermore, after removing the jig, the upper disc spring 14 is placed on the upper surface of the lightning arrester element 9, and the upper electrode 11 is placed on the upper surface of the mounting disc spring 14, and the upper electrode 11 is fixed in a predetermined position using the jig. While being pressed and held at a pressure of
Fix by melting adhesive at 0°C). After that, the lead wire 17°1
8 to complete the burying of the lightning arrester element 9.

Next, the operation of the lightning arrester constructed as described above will be explained.

When an excessive voltage due to a lightning surge is applied to the power transmission line, the current flows through the hanging metal fitting 4 to the pin fitting 8 of the lowest lightning arrester 3, and from the lead wire 18 to the lower electrode 12 to the disc spring. 1
4 -> Lightning arrester element 9 - Belleville spring 14 - Upper electrode 11 -> Lead cotton 17 - Cap fitting 7. Thereafter, the light is transmitted from the cap fitting 7 to the pin fitting 8 of the lightning arrester 3 directly above it. Similarly, it is transmitted to a plurality of lightning arresters 3 connected in series, and is grounded to the earth via the cap fitting 7 of the uppermost lightning arrester 3, the hanging fitting 2, and the support arm 1.

At this time, the lightning arrester element 9 built into the insulator body 5 quickly reduces its resistance value due to its characteristics and discharges the large current caused by the lightning surge. Further, in response to a read current that continues after the lightning surge, the lightning arrester 9 immediately restores its resistance value and restores insulation, so follow-on discharge is suppressed and interrupted, and the electrical line returns to normal.

Now, in the embodiment of the present invention, the upper electrode 11 and the lower electrode 12 made of conductive ceramic are adhesively fixed to both the upper and lower ends of the mounting tube 5d using low melting point glass 13. .12 is fixed in one piece, which improves the airtightness of the inner part of the mounting tube 5d, prevents deterioration of the lightning arrester element 9 due to moisture, increases the durability of the lightning arrester element 9, and improves the reliability. can be improved. Also, electrode 1
There is no need to provide a notch in 1.12 through which the lead wires 17 and 18 are passed, and from this point of view as well, airtightness can be maintained, reliability can be improved, the structure can be simplified, and manufacturing can be easily performed.

In the embodiment described above, the mounting tube 5d and the lightning arrester element 9 were adhesively fixed with silicone rubber 10, but in this case, the lightning arrester element 9 was instantly heated to a high temperature in about 10 microseconds due to a lightning surge or an opening/closing surge. Also, the silicone rubber 10 absorbs the thermal expansion of the lightning arrester element 9 and suppresses excessive stress from acting on the mounting cylinder portion 5d, thereby suppressing damage due to cracks in the mounting cylinder portion 5d.

Note that the present invention is not limited to the above embodiments,
It may be specified as follows.

(1) Two, three, or five or more lightning arrester elements 9 are arranged at equal angles.

(2) The mounting cylindrical portion 5d may be formed separately, or the cylindrical portion 5a may be formed separately.
to be flush with the top surface of the

Effects of the Invention As detailed above, in the present invention, since the mounting cylinder part, upper electrode, and lower electrode are molded from conductive ceramic, the mounting cylinder part and the electrodes are securely bonded and fixed, and airtightness is ensured. However, deterioration of the lightning arrester element due to moisture can be prevented, and durability and reliability can be improved. Furthermore, since there is no need to form a notch in the electrode for passing the lead wire through, the structure is simplified and airtightness is improved, which also has the effect of improving reliability.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical sectional view showing the main parts of a lightning arrester according to an embodiment of the present invention, Fig. 2 is a half-box sectional view showing the lightning arrester element, and Fig. 3 is a front view showing the usage state of the lightning arrester. It is. 3... Lightning arrester, 5... Insulator body, 5a... Cylinder part, 5c... Head, 5d... Mounting cylinder part, 7... Cap fitting, 8... Pin fitting, 9... Lightning arrester, 10
...Silicone rubber as elastic insulation material, 11.12.
... Upper and lower electrodes, 13... Low melting point glass, 17.
18... Lead wire.

Claims (1)

[Scope of Claims] 1. A cap fitting (7) is fixed to the capped cylindrical head (5c) formed at the upper center of the cap portion (5a) of the insulator body (5), and the head (5c) is fixed. A pin fitting (8) is fitted and fixed inside the cap, a mounting cylinder part (5d) is provided in the cap part (5a), and a lightning arrester with non-linear voltage-current characteristics is provided in the mounting cylinder part (5d). The element (9) is fitted, and the upper and lower ends of the mounting tube (5d) are provided with upper electrodes (
11) and a lower electrode (12) are fitted together and adhesively fixed to the mounting cylinder part (5d) using an inorganic material. 2. The device according to claim 1, wherein a low melting point glass (13) as an inorganic material is filled and bonded between the mounting tube portion (5d) and the upper electrode (11) and lower electrode (12). Lightning insulator. 3. The lightning arrester according to claim 1, wherein an elastic insulating material is filled and bonded between the inner circumferential surface of the mounting tube portion (5d) and the outer circumferential surface of the lightning arrester element (9).