JPH0218882Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) This invention suppresses and interrupts follow-on current during lightning flash faults on power transmission and distribution lines, thereby preventing wire breakage due to follow-on arcs and separation of the insulator itself. This relates to lightning-resistant tension insulators.

(Prior technology) Conventionally, as a tension insulator with a built-in lightning arrester,
-167430 and Utility Model Application Publication No. 57-6114 have been proposed, but these tension-resistant insulators have cap electrodes fitted and fixed at both ends of a hollow insulator.
Although a current limiting element and a discharge gap are placed inside the insulator and connected to the cap electrodes at both ends, the power transmission and distribution line may receive an excessive lightning surge, that is, a lightning surge that exceeds the discharge withstand capacity of the current limiting element. Furthermore, even if the current limiting element is below the discharge withstand capacity, it will explode and scatter if the current limiting element deteriorates due to repeated lightning surge discharges, age, poor airtightness, etc. In such cases, the tension insulator holding the wires in place is damaged and easily separated by the tension, causing the wires to fall to the ground or break, leading to secondary accidents. There is a problem.

(Problems to be Solved by the Invention) This invention solves the problems that exist in the conventional technology, namely, when the current limiting element in a tension-resistant insulator that simply has a lightning arrester built into the hollow insulator deteriorates or due to excessive lightning surge, etc. It exploded, the tension insulator was separated,
We are trying to solve the problem of electric wires falling to the ground and breaking.

Structure of the device (means for solving the problem) In order to solve the above problem, this device forms the head of the insulator body into a covered cylinder shape, and the outer periphery of the head is covered with a cap metal fitting. Furthermore, the ground side electrode of the current limiting element unit, in which the ground side electrode and the energized side electrode are connected with a tension insulating rod, is inserted into the inner cavity, and the ground side electrode and the voltage applied side electrode are connected with a filling material. while fixing the cap metal fitting, a discharge end provided on the inner top surface of the cap metal fitting and a discharge end of the ground side electrode are opposed to each other with a predetermined discharge gap through a through hole formed on the top surface of the head; Further, a means is adopted in which a pressure release gap is provided on one side between the inner peripheral surface of the opening of the shade formed in series with the head of the insulator body and the outer peripheral surface of the current limiting element unit.

(Function) This device uses the above-mentioned means to cause lightning impulse overvoltage caused by lightning surges to flash across the discharge gap in power transmission and distribution lines, and to reduce the continuing commercial frequency current of the power line, that is, the follow-on current, to the voltage and current of the current limiting element. It is suppressed and interrupted by the non-linearity of the characteristics, and prevents breakage due to follow-on arcs, damage to the tension insulator itself, and separation, as well as preventing the current limiting element from exploding and scattering due to deterioration or excessive lightning surge. However, by forming a pressure relief gap open to one side between the insulator body and the current limiting element unit, the impact pressure applied to the insulator can be reduced and damage to the insulator itself can be prevented. Even if a part of the insulator body were to break, the cap metal fittings and the electrodes of the current limiting element unit would be fixed together with the filling inside and outside of the covered cylindrical head of the insulator body. This prevents the tension insulator itself from breaking.

(Embodiment) An embodiment embodying this invention will be described below with reference to FIGS. 1 to 3.

FIG. 2 shows an example of a tension device in which a normal tension insulator 9 and a lightning tension insulator 11 of this invention are connected in series. It is an insulator, and a hem 4a of an insulated wire 4 is bound to the upper end thereof by a bind wire 3. Reference numerals 5 and 6 indicate ground-side retaining devices that are fastened to the arm 2; 7 and 8 indicate wire-holding fittings such as retaining clamps for grasping and fixing the insulated wire 4 to form the edging portion 4a; and 9; A normal tension insulator is connected between the grounding side fasteners 5, 6 and the electric wire gripping fittings 7, 8 by connecting pins 10, and 11 is connected between the grounding side fasteners 5, 6 and the tension insulator 9. The lightning-resistant tension insulator of this invention is connected by pins 10.

Next, the lightning-resistant tension insulator 11 will be explained with reference to FIGS. 1 and 3.

Reference numeral 12 denotes an insulator body composed of a deep bowl-shaped shade 12a and a capped cylindrical head 12b integrally formed with the shade, and the top surface of the head 12b is provided with a through hole for discharge. 12c is provided.

Furthermore, a cap fitting 14 is fitted onto the outer periphery of the head 12b of the insulator body 12, and is fixed with a filler 13 such as cement. In addition, 15
is interposed between the head 12b and the cap fitting 14 to prevent the filler 13 from entering the through hole 12c side,
This is a gasket for sealing the gap in the through hole 12c. At the center of the inner top surface of the cap fitting 14, a discharge end 14a protrudes through a predetermined discharge gap G1, corresponding to the through hole 12c of the insulator body 12, and facing a discharge end 16c of the ground side electrode 16, which will be described later. Two ears 14c having connecting holes 14b connected to the ground-side retaining devices 5 and 6 by connecting pins 10 are integrally formed at the end portions thereof. Note that the discharge gap G1 ensures at least an insulation distance that can withstand the line voltage. Further, a pressure relief hole 14d is provided in the upper part of the cap fitting 14. As shown in FIG. 3, a rubber sealing plug 17 having an annular protrusion 17a integrally formed on the body is press-fitted into the pressure release hole 14d, and the sealing plug 17 is inserted into the discharge gap G1. When the pressure exceeds a certain level, it is designed to release and release the pressure.

Next, the current limiting element unit U attached to the insulator body 12 will be explained. Reference numeral 18 is a tension insulating rod made of a material with excellent mechanical strength such as reinforced plastic (FRP). A ground side electrode 16 having a screw hole 16a is screwed into one of the formed screws 18a, and the ground side electrode 16
is fitted into the inner cavity of the head 12b of the insulator body 12 and fixed with a filler 13, and the current limiting element unit U is attached to the opening 12d of the shade 12a. Further, a power supply side electrode 19 having a screw hole 19a is screwed onto the other end of the tension insulating rod 18, and a connection hole 19b is provided to enable connection via a connection pin 10 or the like. A packing 15 is interposed between the ground side electrode 16 and the head 12b to prevent the filler 13 from entering the discharge gap G1 side and to seal the discharge gap G1 at the same time.

A cylindrical current-limiting element 20 made of zinc oxide or the like with excellent nonlinear voltage-current characteristics is fitted onto the outer periphery of the tension-resistant insulating rod 18, and has welded metal or the like on both ends of the current-limiting element 20. Annular electrode plates 21 and 22 made of a soft metal such as a lead alloy are interposed between the electrode surface formed by the power supply side electrode 19 and the ground side electrode 16. The outer periphery of the current limiting element 20 is integrally molded with an elastic insulating material 23 such as ethylene propylene rubber, and a plurality of folds 23a are formed therein. The charging side electrode 19 and the grounding side electrode 16 are provided with an injection port 19c for the elastic insulating material 23,
16b is transparently provided from the outer periphery toward the inner cavity, and the gap between the tensile insulating rod 18 and the current limiting element 20 is also filled with the elastic insulating material 23 to form an internal insulating layer 23c, and the inside of the current limiting element 20 is filled with the elastic insulating material 23. This strengthens the surrounding insulation, provides a buffering effect, and improves airtightness. There is a pressure relief gap G between the opening 12d of the shade 12a and the folds 23a of the elastic insulating material 23.
2 is provided, and the pressure relief gap G2 is open to one side.

In addition, as shown in FIG. 1, a shielding insulating plate 24 is provided on the power supply side electrode 19 so as to shield the opening 12d of the shade 12a and have a gap G3. This is to prevent the intrusion of rainwater, salt dust, etc. Regarding the shielding of the opening 12d, as shown in FIG.
3 may be integrally formed to form the shielding body 23b.

Next, the lightning-resistant tension insulator 11 configured as described above is
The effect of this will be explained.

When a lightning impulse overvoltage occurs in the insulated wire 4 of the power transmission and distribution line due to a lightning surge, this voltage is applied to the lightning insulator 11 from the insulated wire 4 and the wire gripping fitting 7, and the voltage is applied to the voltage-carrying side electrode 19→electrode plate 22→
Current limiting element 20 → ground side electrode 16 via electrode plate 21
The discharge end 16c of the cap metal fitting 14 and the discharge end 14 of the cap fitting 14
The discharge gap G1 between the
It is grounded from the ground through a lead wire (not shown). Furthermore, as shown in FIG. 2, when a normal tension insulator 9 and a lightning tension insulator 11 are connected in series,
The lightning impulse overvoltage flashes through the current limiting element 20 between the surface of the tension insulator 9 and the discharge gap G1. When a lightning impulse overvoltage flashes, a follow-up current is discharged in the path of the flash on the surface of the insulator using only a normal tension insulator, but the lightning-resistant tension insulator to which this invention belongs is able to withstand high voltages such as lightning impulse overvoltage. In this case, the current-limiting element 20 attached to the lightning-resistant tension insulator 11
However, due to the non-linearity of the voltage-current characteristics, the resistance value is quickly reduced to discharge the large current of the lightning surge, and in response to the following current, the line voltage is low, so the resistance value is immediately restored and the insulation is completed. As it recovers, the follow-on discharge is suppressed and cut off, and the electric line returns to normal.

Now, in the present invention, as explained in the embodiment, a cap metal fitting 14 is attached to the outer periphery of the head 12b of the insulator body 12.
At the same time, the ground side electrode 16 of the current limiting element unit U is fixed to the inner cavity of the head 12b, one side is left open, and the inner wall of the opening 12d of the shade 12a and the current limiting element unit U are fixed. Since a pressure relief gap G2 is provided between them, even if the current limiting element 20 explodes and scatters due to deterioration or excessive lightning surge, the elastic insulating material 23
Since the insulator body 12 is coated with a mold, the impact force is alleviated, and impact pressure and flying debris are released from the pressure release gap G2, thereby preventing damage to the insulator body 12 and preventing damage to the insulator body 12 in the event that the insulator body 12 is damaged. Shikasa 1
Even if 2a falls off, the head 12b remains attached to the cap metal fitting 14.
Since it is sandwiched between the cap fitting 14 and the ground side electrode 16 of the current limiting element unit U and is fixed integrally with the filling material 13, the progress of damage is prevented and the cap fitting 14 and the current limiting element unit U are fixed together. The current-limiting element unit U has a tension-resistant structure that connects the ground-side electrode 16 and the energized-side electrode 19 with a tension-resistant insulating rod 18. If the tensile insulating rod 18 is covered with an internal insulating layer 23c made of an elastic insulating material 23 to form a buffer layer, even if the current limiting element 20 explodes, The tension-resistant insulating rod 18 is not cut off, and the wire can be kept in a tethered state, thereby preventing the wire from falling to the ground or breaking. As described above, if the discharge gap G1 is provided with an insulation distance that can withstand the line voltage or more, the line voltage is not always applied, so deterioration is suppressed and the life of the current limiting element 20 is extended. Furthermore, if a pressure relief hole 14d is provided in the cap metal fitting 14 containing the discharge gap G1 and a sealing plug 17 is inserted, the pressure between the cap metal fitting 14 and the ground side electrode 16 can be released due to deterioration of the current limiting element 20, etc. Gap G2
Even if the discharge pressure increases due to lightning surge discharge or follow-on current, if the internal pressure of the cap metal fitting 14 exceeds a certain level, the sealing plug 17 will come off and the pressure will be released, resulting in damage to the cap metal fitting 14 itself or the insulator body 12. is prevented.

In addition, the lightning-resistant tension insulator 11 of the present invention has a discharge gap G
1 is housed inside, but it can be converted to a gear press structure by connecting the cap metal fitting 14 and the grounding side electrode 16, and even as a gear press, it has the ability to cut off large currents and follow current from lightning surges. Of course, it is possible to demonstrate the same.

Furthermore, the embodiment of the present invention has a shade 12 of the insulator body 12.
Since the current-limiting element unit U is installed in the opening 12d of a, the lightning-resistant tension insulator 11 can be manufactured compactly in the same way as when the current-limiting element 20 is built-in, and it does not become an obstacle during installation work or track repair. You can work easily.

In addition, the lightning-resistant tension insulator 11 of the present invention is not only effective at the wire retaining portion, but also has a lower insulation level than the zipper wire support insulator 1.
It prevents flash shorts at the switch, prevents disconnection and damage to the support insulator 1, and furthermore, if it is used to hold the wires on the switch mounting pole, it is possible to omit the lightning arrester that was conventionally attached to the switch pole. Become. As described above, the lightning-resistant tension insulator 11 of the present invention has the shade 12 of the insulator body 12.
If a shield insulating plate 24 or a shield 23b is provided to shield the opening 12d of the shade 12a, it will prevent rainwater and salt dust from entering the opening 12d of the shade 12a, effectively preventing staining and moisture. Salt damage resistance can be improved by suppressing surface leakage current. This invention consists of a current limiting element unit U that covers the opening 12d of the insulator body 12 with an elastic insulating material 23.
Coupled with the fact that the opening 12d is already covered by the attachment, the effect is of course further enhanced.

In the embodiment described above, the lightning-resistant tension insulator is composed of the lightning-resistant tension insulator 9 and the lightning-resistant tension insulator 11, but the lightning-resistant tension insulator 11 may be used alone or in combination.

Effects of the invention As detailed above, this invention has the advantage that even if the current limiting element of the current limiting element unit explodes in the event of a lightning surge discharge at the wire retention point of the power transmission and distribution line, there is little effect on the insulator body. Even if the insulator body is damaged, the lightning-resistant tension insulator itself will not be severed, so it has an excellent effect of preventing the electric wire from falling to the ground or breaking the wire.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a lightning-resistant tension insulator according to an embodiment of the present invention, Fig. 2 is a front view showing a lightning-resistant tension device incorporating the lightning-resistant tension insulator, and Fig. 3 is a sealed structure. FIG. 4 is an enlarged sectional view of only the vicinity of the stopper, and a partial sectional view showing another embodiment of the present invention. 12...Insulator body, 12a...Shade, 12b...
Head, 12c... Through hole, 12d... Opening, 1
3... Filler, 14... Cap fitting, 14a,
16c...discharge end, 16...ground side electrode, 18...
... Tension-resistant insulation rod, 19 ... Voltage-side electrode, 20 ... Current-limiting element, 21, 22 ... Electrode plate, 23 ... Elastic insulating material, 23a ... Crease, 23b ... Shielding body, 24
...Shielding insulating plate, U...Current limiting element unit, G1
...discharge gap, G2...pressure release gap.

Claims (1)

[Claims for Utility Model Registration] 1. The head 12b of the insulator body 12 is formed into a closed cylinder shape, and a cap metal fitting 1 is attached to the outer periphery of the head 12b.
4 and a ground side electrode 16 in the inner cavity.
The ground side electrode 16 of the current limiting element unit U, which is connected between the energizing side electrode 19 with a tension insulating rod 18, is inserted and fixed with a filler, and the head The cap fitting 1 is inserted through the through hole 12c formed on the top surface of the cap fitting 12b.
4 and the discharge end 16c of the ground side electrode 16 are separated by a predetermined discharge gap G.
1, and the opening 1 of the shade 12a is formed in a continuous manner with the head 12b of the insulator body 12.
2d A lightning-resistant tension insulator characterized in that a pressure relief gap G2 that is open on one side is provided between the inner circumferential surface of the current limiting element unit U and the outer circumferential surface of the current limiting element unit U. 2 The current limiting element unit U is the cap 1 of the insulator body 12.
A shielding insulating plate 24 that shields the opening 12d of 2a.
A lightning-resistant tension insulator according to claim 1 of the utility model registration claim, which is provided with: 3 The current limiting element unit U is a tensile insulation rod 18
, the ground side and energized side electrodes 16 and 19 screwed to both ends thereof, and the current limiting element 20 sandwiched between both electrodes 16 and 19 are covered with an elastic insulating material 23. In this case, the insulator body 12
A shielding body 2 that shields the opening 12d of the shade 12a.
3b integrally formed with the elastic insulating material 23, the lightning-resistant tension insulator according to claim 1, which is a registered utility model.