JP2837978B2 - Lightning arrester and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground fault which, when a surge current caused by a lightning strike enters a power line, immediately discharges the surge current to the ground and suppresses and interrupts a subsequent current of a commercial frequency generated thereafter. And a method for manufacturing the same.

[0002]

2. Description of the Related Art
As a lightning arrester, a plurality of resistance elements having non-linear voltage-current characteristics are stacked in series and housed inside a cylindrical pressure-resistant insulating cylinder, and cap-shaped electrode fittings are provided at both ends of the pressure-resistant insulating cylinder. Are fitted and fixed, and a rubber insulating jacket is coated on the outer peripheral surface of the pressure-resistant insulating cylinder. The present applicant has proposed the following as a lightning arrester having such a configuration.

(1) As shown in Japanese Patent Application Laid-Open No. 1-163925, a plurality of resistance elements are directly stacked and accommodated in a pressure-resistant insulating cylinder, and cap-shaped outer peripheral surfaces of both ends of the pressure-resistant insulating cylinder are provided. The electrode fittings are fitted and the bonding interface between the pressure-resistant insulating cylinder and the electrode fittings is bonded and fixed with an adhesive, and thereafter, an insulating jacket having a fold on the outer peripheral surface of the pressure-resistant insulating cylinder is integrally molded by rubber molding.

However, since the above-mentioned lightning arrester has a structure in which the electrode fittings are bonded and fixed to the outer peripheral surfaces of both ends of the pressure-resistant insulating cylinder, it takes a long time for the adhesive to completely cure and develop the bonding strength. However, there has been a problem that the assembling work time becomes longer and the cost increases.

In addition, since the pressure-resistant insulating cylinder and the electrode fitting are joined by bonding, it is necessary to perform processing such as forming irregularities on the joining surface in order to ensure sufficient mechanical bonding strength between the two. There was also.

Further, with the resistance element and the electrode fittings assembled inside the pressure-resistant insulating cylinder, these are housed in a molding die, and molten rubber heated to a predetermined temperature is injected into a cavity of the molding die. In order to mold the insulating mantle, it is necessary to heat not only the pressure-resistant insulating cylinder but also the resistance element and the electrode fitting at the time of molding before molding.Moreover, since the heat capacity is large, the time until the completion of molding is increased, There is a problem that the manufacturing cost increases.

(2) JP-A-61-151913,
As shown in Japanese Patent Application Laid-Open No. 61-200,620, as a conventional lightning arrester, a male screw portion is formed on the outer peripheral surfaces of both ends of a pressure-resistant insulating cylinder, and a female screw portion formed on the inner peripheral surface of the cylindrical portion of the electrode fitting is formed thereon. There has been proposed a structure in which an insulating mantle is rubber-molded on the outer periphery of a pressure-resistant insulating cylinder after being screwed and fixed.

However, in the lightning arrester of the type in which the pressure-resistant insulating cylinder and the electrode fitting are screwed together, the bonding time can be shorter than that of the bonding method (1). Each of them needs to be threaded, which is cumbersome to manufacture and requires the use of an adhesive to prevent rattling caused by the gap between the joining interfaces. This is an obstacle in reducing the emissions.

In addition, as in the conventional example of (1), since not only the pressure-resistant insulating cylinder but also the resistance element and the electrode fitting need to be heated before molding, the thermal efficiency is reduced, and the cost in the manufacturing process is reduced. There was a problem that it was not possible. (3) Further, as a conventional lightning arrester, Japanese Patent Application No. 2-57
No. 298, a plurality of resistance elements are stacked in series, and electrode fittings are arranged via springs at upper and lower ends thereof, and the electrode fittings are pressed by upper and lower pressing jigs. On the outer peripheral surfaces of both electrode fittings, a long insulating member having bolt insertion holes formed at both ends is cylindrically arranged at predetermined intervals, and bolts are inserted into the insulating member from the bolt insertion holes at both ends of the insulation member. There has also been proposed a method in which each of the insulating members is screwed and fixed to the electrode fittings, and finally, an insulating jacket is molded around the outer periphery of the insulating member.

However, in this conventional example, the number of parts is increased, and the assembling work is very troublesome, heat loss increases at the time of molding the insulating jacket, and the cost of the product cannot be reduced. Have problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and a first object of the present invention is to reduce the number of parts to facilitate manufacture and assembly, thereby reducing product costs. It is an object of the present invention to provide a lightning arrester that can be used.

It is a second object of the present invention to provide a method for manufacturing a lightning arrester which can suppress heat loss in a manufacturing process of the lightning arrester and reduce the manufacturing cost.

[0013]

In order to achieve the first object, the invention according to claim 1 accommodates a resistance element having a non-linear voltage-current characteristic inside a pressure-resistant insulating cylinder.
An insulating mantle is formed on the outer periphery of the pressure-resistant insulating cylinder, and the opening at both ends of the pressure-resistant insulating cylinder has approximately the same size as the inner diameter of the pressure-resistant insulating cylinder.
The formed columnar spacer is fitted, and furthermore, cap-shaped electrode fittings are fitted around both ends of the pressure-resistant insulating cylinder, and the cylindrical caulked portion of the electrode fitting is moved to the spacer side with the pressure-resistant insulating cylinder and the insulating member. A means of caulking and fixing to the end of the mantle is adopted.

[0014] Further, since a second aspect of the present invention to achieve the second object, an insulation overcoat member on the outer peripheral surface of the pressure-resistant insulating tube molded formed shape, then the voltage inside the pressure-resistant insulating tube - Current A column containing a resistance element with non-linear characteristics and formed approximately the same size as the inner diameter of the pressure-resistant insulating cylinder inside both ends of the pressure-resistant insulating cylinder.
And a cap-shaped electrode fitting is fitted on both outer peripheral surfaces of the pressure-resistant insulating cylinder, and the cylindrical caulking portion of the electrode fitting is pressed toward the spacer with the pressure-resistant insulating cylinder and the insulating member.
A method of caulking and fixing it to the end of the mantle is adopted.

[0015]

According to the first aspect of the present invention, a spacer is fitted inside the end of the pressure-resistant insulating cylinder, and the cylindrical caulked portion of the electrode fitting is pressed against the end of the pressure-resistant insulating cylinder and the insulating jacket toward the spacer. As a result, the number of parts can be reduced as compared with the above-described structure, and the manufacturing and assembling operations are facilitated, so that the product cost can be reduced.

Further, since the end of the pressure-resistant insulating cylinder is pressure-bonded between the spacer and the cylindrical caulking portion of the electrode fitting, it is not necessary to process unevenness on each pressure-bonded surface, thereby reducing the number of manufacturing steps. Can be.

Furthermore, since the end of the insulating mantle is press-bonded between the outer peripheral surface of the pressure-resistant insulating cylinder and the inner peripheral surface of the caulked portion of the electrode fitting , airtightness can be provided without an adhesive.
Also, in the invention according to claim 2, in the molding step of the insulating mantle, since the resistance element is not housed inside the pressure-resistant insulating cylinder, it is not necessary to heat the resistance element, the thermal efficiency is improved, and the manufacturing is improved. Cost can be reduced.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. Also not a, the lightning insulators produced by the method of the invention will be described with reference to FIG.

On the outer peripheral surface of the pressure-resistant insulating cylinder 1 made of fiber reinforced synthetic resin (FRP), an insulating mantle 2 is formed by EPDM or silicon rubber or the like, including a pressure relief port 15 and excluding the vicinity of the end. A large number of pleats 3 are integrally formed on the outer peripheral surface. The outer peripheral surface of the end portion of the pressure-resistant insulating cylinder 1 is not subjected to unevenness processing for joining with the electrode fittings 9 and 10. A large number of resistance elements 4 made of, for example, zinc oxide or the like having a non-linear voltage-current characteristic are accommodated in a stacked manner in series inside the pressure-resistant insulating cylinder 1. 6, spacers 7 and 8 made of a metal such as aluminum or copper are joined. The outer diameters of the spacers 7 and 8 are formed to be substantially the same as the inner diameter of the pressure-resistant insulating cylinder 1. Further, the pressure-resistant insulating cylinder 1
Cap-shaped electrode fittings 9 and 10 are fitted to the upper and lower ends of the insulating mantle 2 respectively.
Then, the cylindrical caulking portions 11 and 12 of the electrode fittings 9 and 10 are formed.
The inner peripheral surfaces of the first inner peripheral surfaces 11a, 12a having different inner diameters,
The second inner peripheral surfaces 11b and 12b are formed, and the first inner peripheral surface 11b is formed.
a and 12a are caulked and fixed to the outer peripheral surface of the pressure-resistant insulating cylinder 1 toward the spacers 7 and 8, and the second inner peripheral surfaces 11b and 12b are caulked toward the spacers 7 and 8 at the outer peripheral surface at the end of the insulating jacket 2. Fixed.

The outer peripheral surfaces of the pressure-resistant insulating cylinder 1 and the insulating mantle 2 and the inner peripheral surfaces 11a, 12a, 1
An adhesive 13 is applied between the first and second members 1b and 12b to ensure airtightness.

An insulating filler 1 such as silicone rubber is provided between the inner peripheral surface of the pressure-resistant insulating cylinder 1 and the outer peripheral surface of the resistance element 4.
4 have been injected. The pressure-resistant insulating cylinder 1 is provided with a pressure-release hole 15 for releasing a high-temperature, high-pressure gas to the outside due to an internal arc in the event that the resistance element 4 breaks down. The electrode fittings 9 and 10 have screw holes 16 and mounting portions 1.
The screw hole 16 is used to attach a lightning arrester to a support arm or the like of a steel tower, and the attachment portion 17 is used to support a discharge electrode (not shown).

Next, a method of manufacturing the lightning arrester constituted as described above will be described with reference to FIGS. First, as shown in FIG. 2, to produce a pressure-resistant insulating tube 1 alone, while accommodated in a mold (not shown) this alone was cured by injecting molten rubber into the mold cavity, the breakdown voltage An insulating mantle 2 is molded on the outer peripheral surface of the insulating cylinder 1. At this time, the insulating mantle 2 is vulcanized and bonded to the outer peripheral surface of the pressure-resistant insulating cylinder 1.

Next, as shown in FIG. 3, the lower electrode fitting 10 is fitted to the lower end of the pressure-resistant insulating cylinder 1 and the lower surface thereof is supported by the supporting metal fitting 21. In a state where the spacer 8 is accommodated and the upper surface of the spacer 8 is pressed by the spacer pressing jig 22, a plurality of outer peripheral surfaces of the swaging portion 12 of the lower electrode fitting 10 are pressed by the pressing plate 25 attached to the piston rod 24 of the swaging cylinder 23. As shown in FIG. 4, the spacer 8 is pressed toward the center of the spacer 8, and the caulked portion 12 of the electrode fitting 10 is pressed against the end of the pressure-resistant insulating cylinder 1 and the insulating mantle 2.
Secure by swaging. In this step, the pressure-resistant insulating cylinder 1
The airtightness may be improved by applying a resin-based or rubber-based adhesive 13 in advance on the interface between the electrode and the metal fitting 10.

Further, as shown in FIG. 5, the disc spring 6, the resistance element 4, and the disc spring 5 are sequentially accommodated in the pressure-resistant insulating cylinder 1, and the upper surface of the upper disc spring 5 is With the lower end pressed, the molten silicon resin as the insulating filler 14 is injected into the gap between the inner peripheral surface of the pressure-resistant insulating cylinder 1 and the outer peripheral surface of the resistance element 4 from the injection passage 27 formed in the jig 26. Inject and cure. At this time, the air inside the pressure-resistant insulating cylinder 1 is discharged through the exhaust passage 28 formed in the jig 26 , and the filling operation is performed uniformly over the entire gap.

Finally, as shown in FIG. 6, the injection jig 26 is removed, the spacer 7 is fitted inside the upper end of the pressure-resistant insulating cylinder 1, and the upper electrode fitting 9 is fitted around the outer periphery. With the upper surface pressed down by the pressing jig 29, the outer peripheral surface of the caulking portion 11 of the electrode fitting 9 is pressed and fixed by the pressing plate 32 attached to the piston rod 31 of the caulking cylinder 30.

The lightning arrester constructed as described above is
For example, the present invention is applied to a transmission line supporting insulator device, and a lower electrode fitting 1
At 0, a discharge electrode (not shown) on the ground side is supported. Then, from the discharge electrode (not shown) on the power application side supported on the power transmission line side, the air discharge gap flashes over and flows to the discharge electrode on the ground side, and then passes through the resistance element 4 of the lightning arrester and passes through the upper electrode fitting 9. From the tower to the support arm of the tower, and is discharged to the ground. Further, the subsequent current generated thereafter is suppressed and cut off by restoring the air discharge gap and the resistance value of the resistance element 4, thereby preventing a ground fault accident.

In this embodiment, spacers 7 and 8 are fitted inside the end of the pressure-resistant insulating cylinder 1 so that the cylindrical caulked portions 11 and 12 of the electrode fittings 9 and 10 are spacers 7 and 8.
To prevent damage to the pressure-resistant insulating cylinder 1.
Stop and have sufficient bonding strength between the pressure-resistant insulating cylinder 1 and the electrode fittings.
As compared with the conventional connection structure in which screws are formed in the pressure-resistant insulating cylinder 1 and the electrode fittings 9 and 10 or fixed by an adhesive, manufacturing and assembling operations are performed quickly and easily. And the cost of the product can be reduced.

In the above embodiment, the pressure-resistant insulating cylinder 1
Since the insulating mantle 2 is molded into a single body, the resistive element 4 does not exist inside the pressure-resistant insulating cylinder 1. Therefore, the amount of heat for heating the resistive element 4 becomes unnecessary and the molding time is shortened. Can be.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, the spacer 7
(8) and the electrode fittings 9 and 10 are integrally formed.
Although this embodiment has the advantage of reducing the number of parts and the number of assembling steps, it must be selected on a case-by-case basis because it requires time and effort for processing.

[0030]

As described in detail above, according to the first aspect of the present invention, a threaded portion is formed in a pressure-resistant insulating cylinder and an electrode fitting,
And eliminates the step of or applying an adhesive to the bonding interface therebetween can be performed manufacturing and assembling operations quickly and easily, the withstand voltage insulating tube and the electrodes fitting to prevent breakage of the pressure-resistant insulating tube
This has the effect of improving the bonding strength with the steel sheet and reducing the cost of the product.

According to the second aspect of the present invention, it is not necessary to heat the resistance element at the time of molding the insulating jacket.
This has the effect of improving the thermal efficiency and shortening the molding time to significantly reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a half longitudinal sectional view showing one embodiment of a lightning arrester according to the present invention.

FIG. 2 is a longitudinal sectional view showing a pressure-resistant insulating cylinder and an insulating mantle of the lightning arrester.

FIG. 3 is a longitudinal sectional view showing a caulking process of a lower electrode fitting.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a longitudinal sectional view showing a step of injecting an insulating filler into a gap between a pressure-resistant insulating cylinder and a resistance element.

FIG. 6 is a longitudinal sectional view showing a caulking process of the upper electrode fitting.

FIG. 7 is a partial sectional view showing another example of the end fitting.

[Explanation of symbols]

1 pressure-resistant insulating cylinder, 2 insulating mantle, 4 resistance element, 7
Spacer, 8 Spacer, 9 Upper electrode fitting, 10 Lower electrode fitting, 11 Caulking part, 12 Caulking part.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-151913 (JP, A) JP-A-62-274511 (JP, A) JP-A-2-116702 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) H01B 17/00-19/04

Claims (2)

(57) [Claims] 1. A pressure-resistant insulating cylinder accommodates therein a resistance element having a non-linear voltage-current characteristic, and an insulating jacket formed on an outer periphery of the pressure-resistant insulating cylinder. Cylinder formed approximately the same size as the inner diameter of the pressure-resistant insulating cylinder
And a cap-shaped electrode fitting is fitted on the outer periphery of both ends of the pressure-resistant insulating cylinder, and the cylindrical caulking portion of the electrode fitting is moved toward the spacer side with the pressure-resistant insulating cylinder and the insulating outside.
A lightning arrester characterized by being caulked and fixed to the end of the hood . 2. A mold formed form an insulation overcoat member on the outer peripheral surface of the pressure-resistant insulating tube, then the voltage inside the pressure-resistant insulating tube - current characteristics to accommodate the resistive element of nonlinearity, both ends of the withstand voltage insulating cylinder Cylindrical shape with approximately the same size as the inside diameter of the pressure-resistant insulating cylinder inside
Of the spacer fitted, further, the both ends the outer circumferential surface of the pressure-resistant insulating tube fitted a cap-shaped electrode fitting, pressure-resistant insulating tube and insulating outer cylindrical caulking portion of the electrode fitting to the spacer side
A method for manufacturing a lightning arrester, comprising caulking and fixing to an end of a sleeve .