JP2662188B2 - Overhead lightning arrester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester having a spring for pressing a stacked lightning arrester.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional lightning arrester using a non-linear resistance element installed on a supporting tower or the like of an overhead wire is a lightning arrester 31 made of a non-linear resistance element such as zinc oxide.
Are stacked in series and installed in an insulating cylindrical body 32, and a conductive metal spring 3 that presses the end face of the laminated lightning arrester 31.
3, end fittings 34 are provided at both ends of the insulating cylinder 32, and a space 35 is formed in the insulating cylinder 32. The laminated lightning arrester 31, the spring 33, and the space 35 are formed inside the insulating cylinder 32.
Is sealed and stored.

In addition, a pair of intermediate electrodes sandwiching a spring is installed between the upper and lower non-linear resistance lightning arresters, and these are hermetically housed in a porcelain housing cylinder and incorporated into the umbrella of the suspension insulator. Japanese Patent Laid-Open No. 5-190042 discloses a lightning arrester.

[0004]

In the conventional lightning arrester as described above, a laminated lightning arrester and a spring for holding an end face thereof are provided inside an insulating cylinder housing a laminated lightning arrester having a non-linear resistance. Since it is housed and sealed together, the space occupied by the spring installation area will be formed in the insulating cylinder, and if it fails to shut off the subsequent flow of the lightning surge, the high temperature due to the short-circuit current will occur. When the non-linear resistance element is destroyed by the arc and generates high-temperature gas, a large amount of air in the large-volume space in the spring installation area also undergoes rapid thermal expansion, causing the internal pressure to rise sharply and causing an explosion, destroying the lightning arrester. There is a problem of causing a flying accident.

In addition, since a large-volume space for installing the spring must be provided inside the insulating cylinder, there is a problem that the device becomes complicated, the size becomes large, and the weight increases.

The present invention solves the above-mentioned problems, and provides an overhead wire lightning arrester which eliminates a large amount of air which causes a thermal expansion explosion in an insulating tube, prevents explosion and scattering of insulators, and reduces the weight of the device. The purpose is to do so.

[0007]

To achieve the above object, an overhead wire lightning arrester according to the present invention comprises: (1) a lightning arrester having a conductive metal spring 17 for pressing an end face of a laminated nonlinear resistance element 1; An insulator mold outer cylinder portion 19 is provided around the outer periphery of the laminated non-linear resistance element 1 by molding except for the installation area 18 of the spring 17, and the spring 17 is provided outside the insulator mold outer cylinder portion 19. It is a feature.

(2) In the overhead line lightning arrester of (1), an insulating fiber layer 3 for preventing explosion and scattering is provided around the laminated non-linear resistance element 1, and the insulating molded outer cylindrical portion 19 is made of an elastic insulator. It is characterized by being molded with.

[0009]

[Action] The lightning arrester is installed at the supporting tower section of the overhead line,
When a lightning surge is received, a surge current passes through the laminated non-linear resistance element 1 and the conductive metal spring 17 from the electrode portion to protect the overhead line system from the lightning strike. In the unlikely event that a surge current cannot be interrupted and a non-linear resistance element is destroyed by a high-temperature arc of a short-circuit current and a high-temperature gas is generated in the insulator mold outer cylinder portion 19, this insulator mold outer cylinder portion Although the air inside 19 rapidly expands thermally, since the spring installation area 18 requiring a large volume space is provided outside the inside of the insulator mold outer tube portion 19 instead of inside, the insulator mold outer tube portion 1 is provided.
Since a large amount of air due to the space of the spring installation area 18 does not exist in 9 and the amount of internal air in the insulator molded outer tube portion 19 is small, thermal expansion explosion of the large amount of air does not occur. Even if a small amount of air thermally expands, the thermal expansion air pressure does not become high enough to damage the insulator mold outer cylinder portion 19, and damage to the insulator mold outer cylinder portion during a lightning strike is prevented.

As described above, even if the laminated non-linear resistance element 1 is broken and a high-temperature gas is generated, the insulating fiber layer 3 for preventing the explosion and scattering is formed.
As a result, explosion energy is absorbed, and the explosion insulator is prevented from being scattered by the mold outer cylinder portion 19 made of an elastic insulator.

[0011] By molding the insulator-molded outer tube portion 19 except for the spring installation area 18, the insulator-molded portion becomes smaller, and the device becomes lighter.

The conductive metal spring 17 elastically presses the stacked non-linear resistance elements to bring the elements into close contact.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a vertical sectional view of an overhead wire lightning arrester according to a first embodiment of the present invention. Reference numeral 1 denotes a laminated non-linear resistance element in which a plurality of disc-shaped non-linear resistance elements such as zinc oxide are stacked. These non-linear resistance elements are laminated with a conductive metal disk 2 such as an aluminum disk interposed therebetween to reduce the electric contact resistance.
The conductive metal disks 2 are also arranged on the uppermost surface and the lowermost surface of the semiconductor device and laminated in series.

Reference numeral 3 denotes an insulating fiber layer provided on the outer periphery of the laminated non-linear resistance element 1 for preventing explosion and scattering. The insulating fiber layer is different from the insulating coating of the peripheral surface of the zinc oxide disk of the laminated non-linear resistance element 1. , Such as glass fiber, aromatic polyamide fiber (trade name: Kepler, Techmilon) or the like, as shown by a broken line 3 in FIG. It is provided by molding.

Reference numeral 4 denotes a conductive element-made laminated element holding plate, which is provided with a spring end locking portion 5 of a concave portion into which a spring end described later is fitted at the center of the lower surface, and through which a plurality of laminated element holding rod insertion holes are provided near the outer periphery. 6 is provided. This laminated element holding plate 4
Is installed with the concave portion of the spring end locking portion 5 facing downward and the upper surface in contact with the lower surface of the conductive metal disk 2 at the lowermost surface of the laminated nonlinear resistance element 1. This elastically presses the lower surface of the laminated non-linear resistance element 1 by receiving the elasticity of the spring as described later.

Reference numeral 7 denotes a thick rod-shaped upper electrode fitting, which is provided with a plurality of insertion holes 9 for a plurality of stacked element holding rods in a lower end flange 8, and which is provided on the uppermost surface of the stacked non-linear resistance element 1. Is placed in contact with the conductive metal disk 2.

Numeral 10 is a thick rod-shaped lower electrode fitting, and a plurality of laminated element holding rod insertion holes 12
And a spring end locking portion 13 of a concave portion into which the spring end fits is provided at the center of the upper surface of the flange portion 11. The lower electrode fittings 10 are arranged below the laminated element pressing plate 4 with an interval D therebetween.

Reference numeral 14 denotes a laminated element holding rod made of an insulating material such as an FRP or Kepler, which holds a plurality of non-linear resistance elements stacked with the conductive metal disk 2 interposed therebetween in a laminated state. is there. Numeral 15 denotes a nut screwed into the upper thread of the laminated element holding rod 14, and numeral 16 denotes a nut screwed into the lower screw.

Reference numeral 17 denotes a conductive metal spring for pressing the laminated element, which is provided between the laminated element pressing plate 4 and the lower electrode fitting 10, and which elastically holds the laminated non-linear resistance element 1 through the laminated element pressing plate 4. Press with.

The laminated element holding rod is inserted into the plurality of insertion holes 9 of the flange portion 8 of the electrode fitting 7 placed on the laminated nonlinear resistance element 1 alternately stacked with the plurality of conductive metal disks 2. 14 are inserted through the upper ends of the plurality of stacked element holding rods 14 so as to project above the insertion holes 9.
The lower end of each of the stacked element holding rods 14 is inserted into the plurality of insertion holes 12 provided in the flange portion 11 of the lower electrode fitting 10 so as to protrude downward long. The lower end is made to protrude below the insertion hole 12, and the nuts 15 and 16 are screwed into the threaded portions of the upper and lower ends of the stacked element holding rods 14, respectively.

Before the nuts 15 and 16 screwed to the upper and lower ends of the laminated element holding rod 14 are tightened and fixed, the spring end locking portion 5 on the lower surface of the laminated element holding plate 4 and the upper surface of the lower electrode fitting 10 are fixed. The upper and lower ends of the conductive metal spring 17 for pressing the laminated element are fitted into the spring end locking portions 13, and the spring 17 is installed between the laminated element pressing plate 4 and the lower electrode fitting 10.

As described above, the conductive metal spring 17 for pressing the laminated element is installed, and the nuts 15 and 16 screwed to the upper and lower ends of the laminated element holding rod 14 are tightened. And the lower electrode fitting 10, the multilayer element pressing plate 4 is pressed upward by the repulsive force of the spring, and the stacked plurality of non-linear resistance elements are firmly tightened to form a stacked non-linear resistance element. 1 is maintained, and electrical contact between the non-linear resistance elements is ensured. This conductive metal spring 1
Reference numeral 7 denotes a lower laminated element holding plate 4 of the laminated nonlinear resistance element 1.
And the lower electrode fitting 10 are electrically connected.

Reference numeral 18 denotes an installation area of the conductive element spring 17 for pressing the multilayer element provided between the multilayer element pressing plate 4 and the lower electrode fitting 10, and D denotes a multilayer element holder in which the spring installation area 18 is formed. This is the distance between the plate 4 and the upper end flange 11 of the lower electrode fitting 10.

As described above, the laminated element holding rod 1 made of an insulator is used.
4, silicon rubber, EPDM are integrally formed around the insulating fiber layer 3 for preventing explosion and scattering around the outer periphery of the laminated non-linear resistance element 1 in which the plurality of non-linear resistance elements and the conductive metal disks 2 are alternately stacked and laminated. An elastic insulator such as rubber or PTFE is molded to provide an elastic insulator molded outer cylinder portion 19. The area where the elastic insulating mold outer cylindrical portion 19 is formed by molding is a conductive metal spring 17 for pressing the laminated element between the laminated element pressing plate 4 and the lower electrode fitting 10.
This is an area excluding the spring installation area 18 at the interval D, where the periphery of the flange portion 8 of the upper electrode fitting 7 and the circumference of the explosion scattering prevention insulating fiber layer 3 on the outer periphery of the laminated non-linear resistance element 1 and the lower side thereof. An insulating material having elasticity is molded over the periphery of the laminated element pressing plate 4. 19a
Is the upper end of the mold; 19b is the lower end of the mold;
c is an umbrella-shaped portion provided on the outer periphery of the elastic insulating molded outer cylindrical portion 19.

As described above, the elastic insulating material is molded around the insulating fiber layer 3 for preventing explosion and scattering on the outer periphery of the laminated non-linear resistance element 1 except for the installation area 18 of the conductive metal spring 17 for pressing the laminated element. The space region of the spring installation area 18 at the interval D between the laminated element holding plate 4 and the lower electrode fitting 10 is located inside the elastic insulator molded outer cylindrical portion 19 in which the laminated nonlinear resistance element 1 is sealed. Is not formed, but is formed outside thereof.

The lightning arrester constructed as described above is installed between the charging side and the earth side in a supporting tower portion of an overhead line or the like, and when it receives a lightning surge, the upper electrode fitting 7, the laminated non-linear resistance element 1, The overhead wire system is protected from lightning strike through a surge current through the path of the conductive metal laminated element holding plate 4, the conductive metal spring 17, and the lower electrode fitting 10.

If the lightning arrester receiving the lightning surge fails to cut off the follow-up of the lightning surge, the non-linear resistance element is destroyed by the high-temperature arc due to the short-circuit current, and a high-temperature gas is generated. In the overhead wire lightning arrester of the present invention configured as described above, the elastic insulating molded outer cylinder portion 19 does not have a large volume space of the spring installation area as in the related art, and a large amount of air does not exist. Even if high-temperature gas is generated, a thermal expansion explosion accident of a large amount of air does not occur.

If the laminated non-linear resistance element 1 is destroyed and a high-temperature gas is generated due to a failure to block the following flow of the lightning surge, the thermal expansion energy of the high-temperature gas is absorbed by the explosion-scattering insulating fiber layer 3. Elastic insulator molded outer tube portion 19 prevents the explosive insulator from scattering due to its elastic material.

Further, since the insulator-molded outer cylindrical portion 19 is formed except for the spring installation area 18 as described above, the insulator-molded portion is small, and the device is light in weight.

The insulator-molded outer tubular portion 19 is integrally molded with the explosion-scattering-preventing insulating fiber layer 3 on the outer periphery of the laminated non-linear resistance element 1 as described above. Instead of forming such that a slight gap remains between the surface and the inner peripheral surface of the insulating molded outer cylindrical portion 19 integrated with the explosion-scattering insulating fiber layer 3, the outer peripheral surface of the laminated non-linear resistance element 1 The laminated non-linear resistance element 1 may be directly molded integrally with the peripheral surface of the laminated non-linear resistance element 1 so that no air gap is left between the insulating molded outer cylindrical part 19 and the insulator molded outer cylindrical part 19. If no air holding gap is formed in the insulator mold outer tube portion 19 as described above, there is no thermal expansion air in the insulator mold outer tube portion 19, and a large explosion accident does not occur.

FIG. 2 shows a second embodiment of the present invention.
The same reference numerals indicate the same components. In the second embodiment, holding of a plurality of stacked non-linear resistance elements is held by a plurality of stacked element holding rods 14 surrounding the periphery of the stacked non-linear resistance element 1 as in the first embodiment. Instead, the laminated non-linear resistance element 1 is attached to the central laminated element holding rod 20.
Is inserted and held. For this reason, each non-linear resistance element such as zinc oxide is formed in an annular disk shape provided with a center hole 1a, and a conductive metal disk 2 such as an aluminum disk is also formed in a disk provided with a center hole 2a. A plurality of conductive metal disks and each non-linear resistance element are alternately stacked, and the respective center holes 2a, 1a
Is inserted into a laminated element holding rod 20 made of an insulating material such as FRP or Keplera. The upper end 21 and the lower end 22 of the laminated element holding rod 20 are protruded vertically above and below the laminated nonlinear resistance element 1.

As described above, the outer periphery of the laminated non-linear resistance element 1 in which the plurality of conductive metal disks 2 and the plurality of non-linear resistance elements are alternately inserted into the central laminated element holding rod 20 is provided in the first embodiment. Similarly to the above, an insulating fiber layer 3 (shown by broken lines) for preventing explosion and scattering using glass fiber, Keplera fiber or the like is provided in a layered or cylindrical shape.

The conductive metal laminated element holding plate 4a is provided with a laminated element holding rod insertion hole 23 at the center and a convex spring end locking part 24 at the center of the lower surface where the spring end fits.
The outer peripheral portion of the upper surface is formed in a conical surface 25, and the upper surface of the laminated element pressing plate 4 a is brought into contact with the lower surface of the conductive metal disk 2 at the lowermost surface of the laminated non-linear resistance element 1. 23 is inserted through the laminated element holding rod 20 protruding below the laminated nonlinear resistance element 1 and arranged. The laminated element pressing plate 4a elastically presses the lower surface of the laminated non-linear resistance element 1 by receiving elasticity of a spring as described later.

The thick rod-shaped upper electrode fitting 7 is provided at the center thereof with an insertion hole 26 for the laminated element holding rod opened on the lower surface, and a conical surface 27 is formed on the outer periphery of the lower surface of the lower end flange 8.
The upper electrode fitting 7 is brought into contact with the upper surface of the conductive metal disk 2 on the uppermost surface of the laminated nonlinear resistance element 1, and the insertion hole 26 at the center of the upper electrode fitting protrudes above the laminated nonlinear resistance element 1. It is fitted to the upper end 21 of the element holding rod 20. The fitted upper electrode fitting 7 is fixed to the upper end of the stacked element holding rod 20 by compression or screwing.

The thick bottom electrode fitting 10 is provided with an insertion hole 28 for a laminated element holding rod opened at the center in the center, and a spring having a convex portion into which the spring end is fitted at the center of the upper surface of the flange 11 at the upper end. An end locking portion 29 is provided.

The conductive metal spring 17 for pressing the laminated element is inserted into the laminated element holding rod 20 projecting below the laminated element pressing plate 4a, and the lower end 22 of the laminated element holding rod 20 is inserted.
The lower and upper ends of the spring 17 are fitted with the insertion holes 28 of the lower electrode fitting 10, and the spring end locking parts 24 on the lower surface of the laminated element holding plate 4 a and the spring end locking parts 29 on the upper surface of the lower electrode fitting 10. To the laminated element holding plate 4
The conductive metal spring 17 for pressing the laminated element is placed between the a and the lower electrode fitting 10 in a compressed and biased state. If the lower electrode fitting 10 is fixed to the lower end portion 22 of the stacked element holding rod 20 by compression or screwing, the stacked element holding plate 4a
The stacked element holding plate 4a is pressed upward by the elasticity of the spring 17 which is compressed and urged between the lower electrode fitting 10 and the stacked non-linear resistance elements are firmly tightened to maintain the stacked state. At the same time, electrical contact between the non-linear resistance elements is ensured. Further, the conductive metal spring 17 for pressing the laminated element is formed by the laminated non-linear resistance element 1.
Is electrically connected to the lower electrode fitting 10. Reference numeral 18 denotes an installation area of the conductive metal spring 17 for pressing the multilayer element between the multilayer element pressing plate 4a and the lower electrode fitting 10, as in the first embodiment.

As described above, the insulating element holding rod 20 made of an insulator is used.
Non-linear resistance element 1 whose lamination state is maintained by
Around the outer periphery of the insulating fiber layer 3 for preventing explosion scattering,
A mold outer cylinder portion 19 made of an elastic insulator such as silicon rubber, EPDM rubber, or PTFE is provided. As in the first embodiment, the area where the elastic insulator molded outer tube portion 19 is molded is the same as that of the first embodiment.
The area excluding the spring installation area 18 in which the conductive metal spring 17 for pressing the multilayer element is installed between the upper electrode fitting 7 and the periphery of the flange 8 of the upper electrode fitting 7 and the outer circumference of the multilayer nonlinear resistance element 1 are used for preventing explosion and scattering. The elastic insulator is molded over the periphery of the fiber layer 3 and the periphery of the laminated element pressing plate 4a thereunder to provide an elastic insulator molded outer tube portion 19. 19a is the upper end of the mold, 19b
Denotes a lower end portion of the mold, and 19c denotes an umbrella-shaped portion provided on the outer periphery of the elastic insulating mold outer cylindrical portion 19.

As described above, the explosion and scattering prevention of the outer periphery of the laminated nonlinear resistance element 1 except for the area 18 where the laminated element pressing conductive metal spring 17 is provided between the laminated element pressing plate 4a and the lower electrode fitting 10 is provided. By molding an elastic insulator around the insulating fiber layer 3 for use, the space region in which the spring 17 is provided becomes the elastic insulator molded outer cylindrical portion 19 in which the laminated nonlinear resistance element 1 is sealed. It will be formed outside, not inside.

The second embodiment of the present invention constructed as described above, like the first embodiment, is installed between the charging side and the earth side in an overhead wire supporting tower or the like and receives a lightning surge. , Upper electrode fitting 7, laminated non-linear resistance element 1, laminated element holding plate 4a made of conductive metal, conductive metal spring 1
7. Protect the overhead line system from lightning strike through surge current through lower electrode fitting 10. Even if the follow-up interruption of the lightning surge is unsuccessful and the non-linear resistance element is destroyed to generate hot gas, there is no large volume space for the spring installation area in the elastic insulating molded outer cylinder part 19 and a large amount of air Does not exist, there is no thermal expansion explosion of a large amount of air due to the generation of hot gas.

Even if the laminated non-linear resistance element 1 is broken and a high-temperature gas is generated, the explosion-scattering insulating fiber layer 3 absorbs the explosion energy to prevent the debris from being scattered. It is the same as in the first embodiment that the portion 19 prevents the explosive insulator from scattering by the elastic material.

In the second embodiment, since the laminated non-linear resistance element 1 and the conductive metal disk 2 are inserted into and held by a single laminated element holding rod 20 at the center, the holding and assembling thereof is facilitated. .

It should be noted that the insulator-molded outer tube portion 19 in the second embodiment has the laminated non-linear resistance element 1 as described above.
Instead of being integrally molded with the explosion-scattering-prevention insulating fiber layer 3 on the outer periphery of the laminated non-linear resistance element 1 so that a gap is formed between the outer peripheral surface of the laminated non-linear resistance element 1 and the inner peripheral surface of the insulator molded outer cylindrical portion 19. Alternatively, the laminated non-linear resistance element 1 may be integrally molded with the peripheral surface of the laminated non-linear resistance element 1 so that no gap is left between the peripheral surface and the insulator molded outer cylindrical portion 19. If no air gap is formed in the insulator mold outer cylinder portion 19 in this manner, a large explosion accident does not occur because no thermal expansion air exists in the insulator mold outer cylinder portion 19.

[0043]

As described above, the present invention relates to a lightning arrester for pressing the end face of a laminated non-linear resistance element with a conductive metal spring. Molding is performed except for the installation area, and the spring installation area is provided outside the insulator mold outer cylinder, so even if the non-linear resistance element is destroyed during a lightning strike and high-temperature gas is generated, the insulation mold outer cylinder Since there is no spring installation space and a large amount of air does not exist in the unit, a thermal expansion explosion of a large amount of air does not occur, and an explosion damage accident of the lightning arrester can be prevented.

Further, an insulating fiber layer for preventing explosion and scattering is provided around the laminated non-linear resistance element, and the insulating molded outer cylindrical portion is molded with an elastic insulating material. Even in this case, the explosion energy is absorbed by the insulating fiber layer for preventing explosion and scattering, and the explosion insulating material can be prevented from being scattered by the molded outer cylinder portion of the elastic insulating material.

Further, since the insulator molded outer cylinder portion is molded except for the spring installation area, it is possible to form the insulator molded portion smaller than in the conventional molding including the spring installation area as a whole. Can,
The device can be reduced in weight.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a conventional example.

[Explanation of symbols]

 1: laminated non-linear resistance element 3: explosion scattering prevention insulating fiber layer 17: laminated element pressing conductive metal spring 18: spring installation area 19: insulator molded outer cylinder

Continuation of the front page (56) References JP-A-63-108619 (JP, A) JP-A-62-274511 (JP, A) JP-A-3-55691 (JP, U) JP-A-1-140719 (JP) , U) Japanese Utility Model 3 95525 (JP, U) Japanese Utility Model 3-40725 (JP, U)

Claims (2)

(57) [Claims] In a lightning arrester provided with a conductive metal spring for pressing an end face of a laminated non-linear resistance element, an insulator-molded outer cylindrical portion is molded around an outer periphery of the laminated non-linear resistance element except an installation area of the spring. An overhead wire lightning arrester, wherein the spring is provided outside an insulator molded outer cylinder portion. 2. The overhead line lightning arrester according to claim 1, wherein an insulating fiber layer for preventing explosion and scattering is provided around the laminated non-linear resistance element, and the insulator molded outer cylindrical portion is molded with an elastic insulator. Characteristic overhead line lightning arrester.