JPH0677416B2 - Lightning-proof insulator of lightning insulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a withstand voltage insulating cylinder of a lightning protection insulator incorporating a lightning protection element.

(Prior art) Conventionally, this type of lightning insulator has a pressure-resistant insulating cylinder made of FRP or the like with excellent mechanical strength, and cylindrical ground-side and power-discharging-side electrodes are fitted and fixed at the upper and lower ends, respectively. In some cases, a lightning arrester having a non-linear voltage-current characteristic is housed and fixed between the two electrodes, and a rubber mold is provided on the outer circumference.

(Problems to be Solved by the Invention) However, in the case of the tubular body with the both ends simply opened as the withstand voltage insulating tube, the inside of the withstand voltage insulating tube is formed by the electrodes on the ground side and the voltage applying side that are fitted and fixed on the upper and lower sides. Was in a closed state. Therefore, in a special case such as an effective earthing system or an ineffective earthing system where a short circuit current of tens of thousands of amperes is expected, the lightning arrester element abnormally discharges during a large-scale lightning strike, and the high temperature and high voltage arc at that time causes the insulation cylinder to There was a risk that the internal pressure would rise abnormally, causing cracks or ruptures in the insulating cylinder, or even explosion of the lightning protection insulator.

Configuration of the Invention (Means for Solving Problems) In order to solve the above problems, the present invention is directed to a pressure-resistant insulating cylinder 12
Is formed into a basket shape and a plurality of openings g are provided on the side surface thereof.

(Operation) Since the present invention adopts the above means, even if a lightning arrester abnormally discharges and a high-temperature / high-voltage arc is generated during an unexpected large-scale lightning stroke, the arc is emitted from the opening and Abnormal pressure rise is suppressed and damage to the lightning protection insulator is prevented.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 3, suspension insulators 3,3 are rotatably suspended at the left and right ends of the grounding side suspension fitting 2 attached to the tower body 1, and the lower ends of both suspension insulators 3,3 are suspended. A wire-side hanging metal fitting 5 having a discharge electrode 4 in the center is attached to the wire, and an electric wire 7 is hung and supported by the hanging metal fitting 5 via a clamp 6. A lightning protection insulator 9 is attached to the bracket 8 attached to the center of the hanging fitting 2. A discharge electrode 10 is attached to a mounting piece 16b at the lower end of the lightning protection insulator 9, and an air discharge gap G is formed between the discharge electrode 10 and the discharge electrode 4. Further, an arcing ring 11 is provided on one side of the bracket 8 and one side of the mounting piece 16b via arcing ring arm portions (not shown).

Next, the structure of the lightning protection insulator 9 will be described.
As shown in the figure, reinforced plastic (FRP) with excellent mechanical strength, heat resistance, and pressure resistance inside the lightning protection insulator 9
A withstand voltage insulating cylinder 12 made of the above materials is provided.

As shown in FIGS. 1, 2 and 5, the withstand voltage insulating cylinder 12
Is a plurality of radially arranged (8 in this embodiment)
Of the flat plate-like vertical stirrup member 13 and a plurality of (14 in this embodiment) circular transverse stirrup members 14a to 14c arranged in parallel on the outside of the vertical stirrup member 13 and on the inside of both upper and lower ends. And is formed into a basket-shaped cylinder having a plurality of openings g between the vertical reinforcing member 13 and the horizontal reinforcing members 14a to 14c. As shown in FIG. 2, the horizontal reinforcing members 14a are fitted and fixed in a plurality of recesses 13a formed outside each vertical reinforcing member 13. Recesses 13a are also formed inside the upper and lower ends of each vertical streak member 13, and horizontal streak members 14c having a small diameter corresponding to the horizontal streak members 14b on the upper and lower ends of each vertical streak member 13 are fitted and fixed. In this way, the upper and lower ends of the withstand voltage insulating cylinder 12 are
In order to fit the electrodes 15 and 16 on the grounding side and the charging side, which will be described later, they are reinforced by the double transverse members 14b and 14c.

As shown in FIG. 4, the cylindrical grounding electrode 15 having a mounting flange 15a on the outer periphery is fitted and adhered to the upper end of the pressure-resistant insulating cylinder 12, and the lower end of the cylindrical cylinder 12 has a cylindrical shape. The bottomed cylindrical electrode 16 on the power-supply side is fitted and adhered to the engaging cylinder 16a protruding from the bottom center. A mounting piece 16b to which the discharge electrode 10 is mounted is provided on the lower surface of the voltage application side electrode 16.

An element assembly 17 is housed in the pressure-resistant insulating cylinder 12.
This element assembly 17 includes a lightning protection element 18 formed by using zinc oxide (ZnO) as a main material and having a plurality of non-linear voltage-current characteristics stacked in series, and an upper portion connected to the lightning protection elements 18 at the upper and lower ends. And the lower element holding metal fittings 19, 20 and the lightning protection element 18
And a covering 21 made of EPDM rubber provided on the outer circumferences of both element pressing fittings 19, 20. The position of the lower end of the element assembly 17 is regulated by the engagement between the lower portion of the lower element pressing fitting 20 and the engagement cylinder 16a of the power-supply-side electrode 16.
Further, the outer peripheral surface of the fastening metal fitting 22 is screwed onto the inner peripheral surface of the ground side electrode 15. A terminal metal fitting 24 is fixed to the center of the fastening metal fitting 22 through a cylindrical insulating spacer 23.
The lower end of this terminal fitting 24 and the element holding fitting 19 at the top of the element assembly 17
A spring 25 is interposed between and. This spring 25
Due to the urging force, the upper and lower ends of the element assembly 17 are connected to the terminal fittings 24
Also, the pressure is applied to the charging side electrode 16 and a contact pressure is applied between the plurality of lightning protection elements 18. The spring 25
Provides a good electrical connection by winding a plurality of shafts (three in this embodiment).

Further, as shown in FIG. 4 and FIG.
A rubber mold 27 made of EPDM rubber is provided between the 12 and the element assembly 17, between the ground side electrode 15 and the terminal fitting 24, and on the outer side of the pressure resistant insulating cylinder 12. Also, the rubber mold
Reference numeral 27 covers the lower outer peripheral surface of the ground side electrode 15 and the upper outer peripheral surface of the voltage application side electrode 16, and integrally forms a fold 27a protruding outside the main body of the lightning protection insulator 9. Further, the rubber mold 27 is provided with a pressure release port 27b at a position corresponding to the arcing ring 11 shown in FIG.

Next, the operation of the insulator device configured as described above will be described.

Now, when a lightning surge enters the electric wire 7 due to a lightning stroke, the electric current is arc-discharged from the electric wire 7 to the discharge electrode 10 of the lightning protection insulator 9 through the air discharge gap G from the clamp 6 → the hanging metal fitting 5 → the discharge electrode 4. The current flows from the power-supply-side electrode 16 to the lightning protection element 18 via the lower element holding metal fitting 20, and further flows from the body 1 to the ground via the upper element holding metal fitting 19 → shunt 26 → terminal metal fitting 24 → hanging metal fitting 2. The follow-up current accompanying this is blocked by the lightning protection element 18.

Further, when the lightning arrester element 18 is abnormally discharged by an unexpected large-scale electric shock and a high-temperature and high-voltage arc is generated, this arc causes a part of the coating 21 near the opening g and a part of the rubber mold 27, particularly the pressure release port. The area around 27b is destroyed and the arc is released to the outside. Therefore, abnormal pressure rise in the withstand voltage insulating cylinder 12 is prevented. The arc released to the outside is transferred to the arcing ring 11.

Furthermore, when an arc occurs in the lightning protection element 18, a pressure-resistant insulating cylinder
Even if a radial stress is generated on the inner side, the horizontal reinforcing member 14a is configured to hold the radial arrangement of the vertical reinforcing members 13 as shown in FIG. Since the FRP having a high strength can be used, the pressure resistance is improved. In addition, the vertical bar member 13 and the horizontal bar member 14
Since the a to 14c are orthogonally combined, the stress is equally distributed in the vertical and horizontal directions, and moderate stress concentration does not occur at the joint portion between the two reinforced members 13, 14a to 14c.

As described above, in the withstand voltage insulating cylinder 12, abnormal boosting and stress concentration due to arcing of the lightning protection element 18 inside thereof are suppressed, and thereby damage to the lightning protection element 9 is prevented.

The pressure-resistant insulating cylinder 12 includes a vertical streak member 13 and a horizontal streak member 14a.
It is possible to reduce the weight because it is formed in a basket shape with a small volume by 14c.

Further, since it has a basket-like shape and the opening g extends over the entire length, it is characterized in that the rubber can smoothly infiltrate into the pressure-resistant insulating cylinder 12 during the rubber molding and can be easily manufactured.

The present invention can also be implemented as follows.

(1) As shown in FIG. 6, a plate-shaped vertical reinforcing member 28 in which pressure-proof insulating cylinders are radially arranged, and a flat plate which is orthogonal to the vertical reinforcing member 28 and connects between the vertical reinforcing members 28 in a ring shape. Transverse member 29
To be integrally formed into a basket-shaped cylinder by and.

(2) As shown in FIG. 7, a ring that is attached to the vertical reinforcing member 30 by fitting the pressure-proof insulating cylinder into the rod-shaped vertical reinforcing member 30 and the recess 30a on the outer side of the vertical reinforcing member 30 and orthogonal to the vertical reinforcing member 30. Forming into a basket-like cylinder with the horizontal transverse members 31.

As described in detail above, according to the present invention, the withstand voltage insulating cylinder is formed into a cage shape and a plurality of openings are provided on the side surface thereof. Even if an arc occurs, it is possible to prevent abnormal pressure rise and stress concentration in the pressure resistant insulation cylinder, to prevent cracking and rupture of the pressure resistance insulation cylinder and damage to the lightning protection insulator. Has the effect of facilitating the infiltration of water and facilitating the manufacture.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a pressure-proof insulating cylinder embodying the present invention, FIG. 2 is a partially enlarged cutaway view of the pressure-proof insulating cylinder, and FIG. 3 shows an insulator device equipped with a lightning protection insulator. Front view, Fig. 4 is a vertical sectional view of the lightning arrester, and Fig. 5 is A- in Fig. 4.
A line sectional view, FIG. 6 is a partially enlarged view showing another example of the withstand voltage insulating cylinder, and FIG. 7 is a partially enlarged view showing the other example of the same withstand voltage insulating tube. 9: Lightning arrester, 12 ... Withstand voltage insulation cylinder, 13, 28, 30 ... Vertical bar member,
14a to 14c, 29, 31 ... Horizontal members, 15 ... Grounding side electrode, 16 ... Charging side electrode, 18 ... Lightning rod, 27 ... Rubber mold, g ... Opening.

Claims (3)

[Claims] 1. Cylindrical ground-side electrodes (1
5) and the charging side electrode (16) are fitted and fixed, and both electrodes (1
5), (16) Lightning arrester (1
8) is accommodated and fixed, and a rubber mold (2
In the withstand voltage insulation tube (12) of the lightning protection insulator (9) provided with 7), the withstand voltage insulation tube (12) is formed in a cage shape, and a plurality of openings (g) are provided on the side surface thereof. Insulator withstand voltage insulation tube. 2. A pressure-resistant insulating cylinder (12) is provided with a plurality of vertical stirrup members (1).
Claim 1 which comprises 3) and a plurality of horizontal reinforcing members (14a to 14c) attached orthogonally to these vertical reinforcing members (13).
A voltage-proof insulating cylinder for a lightning insulator according to the item. 3. Vertical stirrup members (13) and horizontal stirrup members (14a-14c).
Are pressure-resistant insulating cylinders of a lightning arrester according to claim 2, each of which is made of reinforced plastic (FRP).