JPS6394509A - Arresting insulator - 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 Object of the Invention (Field of Industrial Application) The present invention relates to a lightning arrester having a power transmission line support function used in a power transmission line.

(Prior art) As a conventional lightning arrester, for example, Utility Model No. 58-63844
There was something disclosed in the issue. This involves fitting and fixing a cylindrical non-linear resistance element to an insulating rod, fitting and fixing terminal fittings on the energizing side and grounding side to both the upper and lower ends of the insulating rod, and then molding the non-linear resistance element and the terminal fittings into a rubber mold. It was stored and fixed in one piece.

(Problem to be Solved by the Invention) However, since the conventional lightning arrester is packaged in one piece, if a non-linear resistance element becomes defective during the manufacturing process, the entire product becomes unusable, resulting in reduced material costs. Not only is waste forced, but during use, the amount of expansion and contraction of each member differs due to differences in thermal expansion coefficients, and when relative movement occurs between each member, separation occurs and creates voids that allow moisture to enter. This problem easily occurs, leading to a decrease in insulation strength and reliability.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a tension insulation rod made of reinforced plastic, and a pair of tension insulation rods that are fitted and fixed to both ends of the tension insulation rod. The gripping metal fitting is fitted to the outer periphery of the tension-resistant rod via an insulating sliding compound so as to be movable relative to the axial direction, and a non-linear resistance element in a shape of a donut is laminated in series within a bendable insulating cylinder. A non-linear resistance element unit containing a linear resistance element group and molded with a rubber layer on the gap between the bendable insulating tube and the non-linear resistance element group and on the inner peripheral surface of the non-linear resistance element group; The outer periphery of the element unit is fitted to the outer periphery of the element unit so as to be able to move relative to each other in the axial direction via an insulating sliding compound, and the outer casing unit is made of rubber and has a large number of folds formed on the outer periphery. There is.

(Function) Since the present invention employs the above-mentioned means, the tension insulation rod can expand and contract due to changes in the load of the power transmission line or wind pressure, and the tension insulation rod, non-linear resistance element unit, and sheathing unit have a coefficient of thermal expansion. Even if relative movement occurs between them due to differences in the amount of expansion and contraction, it is absorbed by the insulating sliding compound, eliminating unreasonable stress from being applied to each member, and preventing cracks and damage. Not only can the durability be improved, but also the formation of voids can be eliminated to prevent moisture from entering, and the reliability of the insulation strength can be improved. In addition, since the non-linear resistance element unit is fitted to the tension-resistant insulating rod and the outer cover unit is fitted to the non-linear resistance element unit, manufacturing and assembly are facilitated, and even if a defective product is produced, it will not be defective. Since the product can be completed by simply replacing the parts that have become damaged, costs can be reduced.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 16.

As shown in FIG. 16, a lightning arrester 4 is attached to the suspension fitting 2 of the steel tower 1 via a connecting pin 3 to prevent swinging.

Further, a power transmission line 7 is held at the lower end of the lightning arrester 4 via a connecting bin 5 and a hanging fitting 6.

As shown in FIGS. 1, 2, and 16, the lightning arrester 4 includes an elongated cylindrical tension insulating rod 8 made of reinforced plastic (FRP) and caulked to both upper and lower ends of the rod. Ground side and energizing side gripping fittings 9 and 10 made of fixed structural steel materials, a nonlinear resistance element unit 11 which will be described in detail after being fitted onto the outer periphery of the tension insulating rod 8, and the nonlinear resistance It is composed of a rubber jacket unit 25 having a large number of pleats 25a fitted into the outer peripheral surface of the element unit 11, and arcing rings 32, 33 supported by the re-gripping fittings 9, 10.

First, a method of manufacturing the non-linear resistance element uni-node 11 will be explained with reference to FIGS. 7 to 10.

As shown in FIG. 7, a plurality of donut-shaped nonlinear resistance elements 12 made of zinc oxide or the like having nonlinear voltage-current characteristics are stacked in series, and the upper and lower ends are made of copper alloy or aluminum alloy. The donut-shaped ground side and energized side electrode plates 13 and 14 are joined together, and a plurality of intermediate electrodes 15 (only - shown) are interposed at a predetermined pitch between the non-linear resistance elements 12. The members are bonded and fixed to each other using a conductive adhesive 16 applied to the bonding surfaces in advance to form a group of non-linear resistance elements 17 having an elongated cylindrical shape. Note that as the conductive adhesive 16, for example, a glass base material containing silver powder is used, and the temperature is 300 to 400°C.
Melt and glue. This conductive adhesive 16 ensures electrical continuity of each member and ease of assembly, and also prevents the rubber layer 24 from entering during molding of the rubber layer 24, which will be described later, by eliminating gaps between the joint surfaces of each member. It has the function of

Next, as shown in FIG. 8, an elongated cylindrical tube made of reinforced plastic is provided with a plurality of pressure relief ports 18a (in this embodiment, four locations every 90 degrees as shown in FIG. 3) at least at both the upper and lower ends. A ring-shaped tightening fitting 19 on the power supply side for a female thread 18b formed on the inner circumferential surface of the lower end of the curved insulating cylinder 18
At the same time, a plurality of disk springs 20 are placed on the upper surface of the fastening fitting 19, and the electrode plate 14 at the lower end of the non-linear resistance element group 17 is brought into contact with the upper surface thereof. In addition, bend-resistant insulating tube 1
A cylindrical ground-side fastening fitting 21 is temporarily screwed into the internal thread 18c formed on the inner circumferential surface of the upper end of the electrode plate 8, and the lower surface of the fastening fitting 21 is brought into contact with the electrode plate 13. Next, as shown in FIG. 9, with the lower surface of the electrode plate 19 supported by the support 22, the inner protrusion 13a of the electrode plate 13 is pressed against the pressing jig 22.
2a to compress the disc spring 20 and fully tighten the tightening fitting 21. At this time, nonlinear resistance element group 1
7 is held in pressure contact between both wired members 19 and 21 by a disk spring 20, and the outer peripheral surface of the non-linear resistance element group 17 and the bendable insulating cylinder 1
A predetermined gap is formed between the inner circumferential surface of 8 and the inner circumferential surface of 8.

Next, after removing the support tool 22 and the pressing jig 22a, an outer mold (the path shown in the figure) is placed on the outer peripheral surface of the bendable insulating tube 18, and the non-linear resistance element group 17 and the clamping metal odor 19. A molding iron (as shown) is inserted into the inner side of the non-linear resistance element group 17, and molten EPDM rubber is press-fitted into each gap to form a predetermined thickness on both the inner and outer sides of the non-linear resistance element group 17, as shown in FIG. A rubber layer 24 having an insertion hole 24a is formed. This rubber layer 24
When molding, a plurality of holes (9 in FIG. 4) are formed on the intermediate electrode 15.
The molten rubber enters both the inside and outside of the non-linear resistance element group 17 through the passages 15a (4 places at each 0 degrees), and also through the pressure relief opening 18a formed in the bendable insulating tube 18. A rubber layer 24 is also formed on the inside of the clamping fitting 19.21.

In addition, before molding the rubber Fii 24, the nonlinear resistance element 1 is
2. An adhesive (the path shown in the diagram) may be applied to the surfaces of the bendable insulating tube 18 and the fastening fittings 19, 21, etc., so that the adhesive reacts during rubber vulcanization and improves the adhesive effect. good.

Thereafter, the mold is released, and the manufacturing of the integral non-linear resistance element unit 11 shown in FIG. 10 is completed.

Next, a method of manufacturing the jacket unit 25 will be explained with reference to FIG. 11.

This jacket unit 25 is also molded with a mold (as shown in the diagram) before assembly.
It is molded in one piece. A spiral groove 25b is simultaneously formed on the inner circumferential surface of this jacket unit 25 during molding, and is filled with an insulating sliding compound to prevent moisture absorption to the interface. Note that even if the spiral groove 25b is present, the mold can be removed by relatively rotating the mold and the jacket unit 25.

Next, the tension insulating rod 8 described above with reference to FIGS. 12 to 15 is
, gripping fitting 9. IO1 non-direct non-linear resistance element Uniet 11
The process of assembling the lightning arrester 4 using the jacket unit 25 will be explained.

First, as shown in FIG. 12, the power-supplying side gripping fitting 10 is fitted onto the lower end of the tension insulating rod 8 and fixed by caulking.

On the other hand, as shown in FIG. 13, a reinforcing collar 26 is screwed onto the female thread 18b of the bendable insulating cylinder 18 of the non-linear resistance element unit 11, and a reinforcing collar 26 is provided inside the collar 26 for electrical conduction and expansion/contraction absorption. A coil-shaped spring 27 is accommodated, and an elastic member 28 having the function of absorbing insulating silicone rubber 29 as an insulating sliding compound made of foamed rubber is set inside the spring 27. After that, the insulating silicone rubber 29 is applied to the outer peripheral surface of the tension insulating rod 8 and the inner peripheral surface of the insertion hole 24a of the rubber layer 24, and then a non-linear resistance element is placed on the outer periphery of the tension insulating rod 8 as shown in FIG. The unit 11 is fitted so as to be relatively movable in the vertical direction.

Furthermore, as shown in FIG. are fitted to allow relative movement in the axial direction. At this time, the insulating silicone rubber 29 accumulates in the spiral groove 25b of the sheathing unit 25, making it possible to more reliably absorb moisture at this interface and facilitating relative movement between the bendable insulating tube 18 and the sheathing unit 25. At the same time, the uneven spiral groove 25b increases the pressing force against the outer circumferential surface of the bendable insulating cylinder 18, thereby stabilizing the assembled state. Note that this spiral groove 25b
Similar to a! A spiral groove may be formed on the inner peripheral surface of the rubber layer 24.

Thereafter, as shown in FIG. 1, the ground-side gripping metal fitting 9 is fitted onto the upper end of the tension-resistant insulating rod 8 and fixed by caulking, and the flange portions 9a and 10a of both gripping metal fittings 9 and 10 are
A caulked portion 9b provided on the outer periphery.

10b is caulked and fixed to protrusions 25c integrally formed on the outer periphery of both ends of the jacket unit 25.

In this way, the assembly of the lightning arrester 4 is completed.
In the pole mounted state, a support arm 31 is fixed to the gripping metal fitting 9.10 by a pair of brackets 30, and an electric field is concentrated between the tips of the support arm to avoid corona in the air and corona inside the jacket unit 25. A notched annular arcing ring 32,33 is attached for this purpose.

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

Now, when a surge current due to a lightning strike flows through the power transmission line 7 and enters the gripping fitting 10 of the lightning arrester 4 via the hanging fitting 6,
This current flows through the spring 27, the clamping fitting 19, the disc spring 20, the electrode plate 14, the non-linear resistance element 12, the intermediate electrode 15, the non-linear resistance element 12, the electrode plate 13, the clamping fitting 21 and the gripping fitting 9.
It flows to the steel tower 1 through the hanging metal fitting 2, and is grounded.

When the non-linear resistance element group 17 becomes conductive due to an unexpected lightning strike, an abnormal current of the commercial frequency voltage flows into the non-linear resistance element group 17, resulting in a short-circuit condition, and the pressure relief port is released from near the non-linear resistance element 12 at both the upper and lower ends. A high-temperature, high-pressure arc blows out through the tube 18a while melting the rubber layer 24 and a portion of the jacket unit 25. This arc is the arcing ring 3
2.33, and destruction of the nonlinear resistance element group 17 due to abnormally high pressure is suppressed.

Note that the hanging load of the power transmission line 7 acts entirely on the tensile insulating rod 8, and the bending load acting on the lightning arrester 4 is mainly shared by the bending insulating rod 8.

Now, in the embodiment of the present invention, the nonlinear resistance element unit 11 prepared in advance by coating the tension insulating rod 8 with insulating silicone rubber 29 is assembled so as to be relatively movable in the axial direction. Similarly, insulating silicone rubber 29 was applied to the outer circumferential surface of the outer cover unit 25, and the cover unit 25 was fitted so as to be movable relative to each other, so after centering each member,
Compared to conventional lightning arresters that are rubber-molded at the end, the load of the power transmission line 7 or the wind pressure acting on the power transmission line 7 acts on the tension-resistant insulating rod 8, or expands due to heat in areas with severe weather conditions. - Even if shrinkage occurs and relative movement occurs due to differences in the thermal expansion coefficients of each member, it can be easily absorbed, preventing cracks and breakage of each member, and improving durability. Further, the insulating silicone rubber 29
This prevents the formation of voids in the relative movement portion, thereby preventing moisture from entering and improving the reliability of insulation strength.

Furthermore, in the embodiment of the present invention, the nonlinear resistance element unit 11
The rubber layer 24 can be easily molded using only the unit, and the tensile insulating rod 8, the nonlinear resistance element unit 11, and the jacket unit 25 can be easily assembled, and both units IL25 can be easily formed. Even if a defective product is produced during the manufacturing process or a failure occurs during assembly, the entire lightning arrester does not have to be scrapped, and therefore the cost of the product can be reduced.

Note that the present invention can also be embodied in the following embodiments.

(1) The intermediate electrode 15 is omitted.

(2) Shunt for energizing the spring 27 (diagram waterway)
shall be established.

Effects of the Invention As described in detail above, the present invention allows the tension insulating rod to expand and contract due to the electrical charge of the power transmission line or fluctuations in wind pressure, and the tension insulating rod, the nonlinear resistance element unit, and the jacket unit to expand and contract due to changes in the thermal expansion coefficient. Even if relative movement occurs between them due to differences in the amount of expansion and contraction, it is absorbed by the insulating sliding compound, eliminating unreasonable stress from being applied to each member, and preventing cracks and damage. In addition to increasing durability,
By eliminating the formation of voids, it is possible to prevent moisture from entering and improve the reliability of insulation strength. In addition, since the non-linear resistance element unit is fitted to the tension-resistant insulating rod and the outer sheath unit is fitted to the non-linear resistance element unit, manufacturing and assembly are facilitated, and even if a defective product is produced, it will not be defective. Only the damaged parts need to be replaced, which has the effect of saving material costs and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a half-longitudinal sectional view showing the grounding side end of the lightning arrester according to the present invention, FIG. 2 is a half-longitudinal sectional view showing the energized side end, and FIG. 4 is an end view taken along line B-B in FIG. 1, FIG. 5 is an end view taken along line C-C in FIG. 2, and FIG. 6 is an end view taken along line D in FIG. Figures 7 to 10 are cross-sectional views for explaining the manufacturing process of the nonlinear resistance element unit, Figure 11 is a half-longitudinal cross-sectional view of only the jacket unit, and Figures 12 to 15 are cross-sectional views of the lightning arrester. FIG. 16 is a sectional view for explaining the assembly process, and a front view showing the usage state of the lightning arrester. 4... Lightning arrester, 8... Tension-resistant insulation rod, 9 (10).
...Grounding side (voltage side) gripping metal fitting, 11...Non-linear resistance element unit, 12...Non-linear resistance element, 17...
Nonlinear resistance element group, 18...Bendable insulating cylinder, 19.21
... Tightening metal fitting, 24 ... Rubber layer, 25 ... Outer cover unit, 25a ... Fold, 25b ... Spiral groove, 25
c... Projection, 29... Insulating silicone rubber as an insulating sliding compound.

Claims (1)

[Scope of Claims] 1. A tension insulation rod made of reinforced plastic, a pair of gripping fittings fitted and fixed to both ends of the tension insulation rod, and an insulating sliding compound applied to the outer periphery of the tension insulation rod. A group of non-linear resistance elements in which donut-shaped non-linear resistance elements are stacked in series is housed in the bend-resistant insulating cylinder so that they can move relative to each other in the axial direction. A non-linear resistance element unit is formed by molding a rubber layer on the gap between the resistance element group and the inner peripheral surface of the non-linear resistance element group, and the outer circumference of the non-linear resistance element unit is axially connected to the outer circumference of the non-linear resistance element unit through an insulating sliding compound. 1. A lightning arrester comprising: a rubber jacket unit which are fitted together so as to be movable relative to each other and have a large number of folds formed on the outer periphery. 2. The non-linear resistance element unit includes a bendable insulating cylinder having a plurality of pressure relief ports at least at both upper and lower ends thereof, a fastening fitting screwed and fixed to both upper and lower ends of the bendable insulating cylinder, and both fastening fittings. a non-linear resistance element group interposed between; a spring interposed between the lower end of the non-linear resistance element group and the fastening fitting;
The lightning arrester according to claim 1, comprising rubber layers formed on both the inner and outer sides of the non-linear resistance element group. 3. A flange portion is formed at the base end of the gripping metal fitting,
The lightning arrester according to claim 1, wherein the caulking portion formed on the outer periphery of the flange portion is caulked and fixed to the protrusion formed on the outer periphery of the end portion of the jacket unit. 4. A spiral groove is formed on the inner circumferential surface of the jacket unit and the inner circumferential surface of the rubber layer, as claimed in claim 1 or 2.
Lightning arrester described in Section.