JPH01243319A - Lighting insulator and manufacture thereof - Google Patents

Abstract

PURPOSE:To ensure sufficient insulation between a voltage resisting insulating cylinder and a current limiting element unit by injecting an insulating material through pressure releasing holes of the voltage resisting insulating cylinder having received ring-shaped foaming elastic members in both end portions thereof. CONSTITUTION:Pressure releasing holes 12 are provided in the wall of an voltage resisting insulating cylinder 1 containing a current limiting element unit 3 and ring- shaped foaming elastic members 10, 11 at the both ends thereof and electrode fittings 5, 6 are fixedly connected to both ends of the cylinder 1 and an insulating material is injected through the holes 2 when an insulating jacket body 12 is molded. In this case, the space between the cylinder 1 and the unit 3 is evacuated to expand the volume of the members 10, 11 and subsequently the insulating material is injected thereby the members 10, 11 are compressed into flat shape. The evacuation decreases the residual air and when the members 10, 11 are flattened to contract their volume, the residual air is drawn toward the contracted region and concentrated therein so that the mixing of the air into inside insulating layer is greatly suppressed and thereby sufficient insulation between the voltage resisting insulating cylinder and the current limiting element unit is ensured and a highly reliable lighting insulator is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lightning arrester and a manufacturing method thereof.

(Prior art) As a conventional lightning arrester, a pair of electrode fittings are fitted and fixed to both ends of a voltage-proof insulating tube that houses a current-limiting element unit inside, and an insulating jacket is attached to the outer circumferential surface of the voltage-proof insulation tube IRfl4 and both electrode fittings. It is known that the body is molded and an inner insulating layer is provided between the voltage-resistant insulating cylinder and the current limiting element unit.

(Problems to be Solved by the Invention) However, in this conventional lightning arrester, when filling an insulating material to serve as an inner insulating layer between the L-mo insulating tube and the current limiting element unit, the inside of the insulating material is If air remains in the tube, the insulation between the voltage-resistant insulating tube and the current-limiting element unit will be reduced, so there is a problem in that special measures are required for the mold or vacuum fl[, etc.] to prevent this. .

This invention was made by paying attention to the problems existing in the conventional technology, and aims to minimize the air that gets mixed into the inner insulating layer between the pressure-resistant R cylinder and the current limiting element unit. This is a highly reliable solution that can ensure sufficient insulation between the voltage-resistant insulation cylinder and the current-limiting element unit! ! ?
The purpose of this invention is to provide a lightning arrester, and also to provide a manufacturing method suitable for manufacturing the lightning arrester.

(Means for Solving the Problems) In order to achieve the above object, the lightning arrester of the present invention includes a voltage-resistant insulating cylinder, a current-limiting cable unit housed inside the voltage-resistant insulating cylinder, Electrode fittings fitted and fixed to the upper and lower ends of the pressure-resistant supply RWi, ring-shaped closed foam insulating elastic material accommodated in the upper and lower ends of the voltage-resistant insulation cylinder, and molded on the outer peripheral surfaces of the voltage-resistant insulation cylinder and the electrode metal fittings. In addition, in the method for manufacturing a lightning arrester insulator of the present invention, an *m metal fitting is fitted to one end of the voltage-resistant insulating cylinder. fixed, a ring-shaped closed foam insulating elastic material is housed inside one end of the pressure-resistant insulating tube, and a current-limiting element unit is housed inside the pressure-proof insulating tube,
One end thereof is engaged with the electrode fitting, and a ring-shaped closed foam insulating elastic material is housed inside the other end of the voltage-proof insulating cylinder, while another electrode fitting is attached to the other end of the current-limiting element unit. and an insulating mantle to form an insulating mantle on the outer circumferential surface of the voltage-proof insulating tube and both electrode fittings, and an inner insulating layer between the current-limiting element unit and the voltage-proof insulating tube. A vacuum is drawn between the flow element unit and the voltage-resistant insulating cylinder to expand both closed-cell foam insulating elastic materials, and then an insulating material is injected to form an insulating jacket. Insulating material is injected between the pressure-resistant insulating cylinder and the current-limiting element unit through the pressure relief hole formed in the cylinder.
E: Both closed foam insulating elastic materials are compressed.

(Function) According to the lightning arrester configured as described above and the manufacturing method thereof, when molding the insulating jacket and the inner insulating layer, the ring-shaped closed-cell foam insulating elastic material is housed inside both ends of the voltage-resistant insulating cylinder. is expanded in volume as a result of evacuation, and then compressed into a flat shape as insulating material is injected. Therefore, the amount of air remaining between the pressure-resistant insulating tube and the current-limiting element unit 1- during vacuuming is reduced, and the remaining air is attracted when the closed-cell foam insulating elastic material shrinks in volume into a flat shape. Since the air is concentrated in the contracted portion, the amount of air mixed into the inner insulating layer filled subsequently can be kept to a minimum.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, the voltage-resistant insulation n1 is formed of reinforced plastic (FRP) or the like into a cylindrical shape with both upper and lower ends open, and a plurality of pressure relief holes 2 are formed in it. Voltage -
The current limiting element unit 3, which is mainly made of zinc oxide (ZnO) or the like with non-linear current characteristics, is housed inside the voltage-resistant insulating cylinder 1, and has contact fittings at both the upper and lower ends. 4
, 5 are provided.

A pair of electrode fittings 6 and 7 are fitted to both upper and lower ends of the voltage-resistant insulating cylinder 1 and fixed with an adhesive 8, respectively.

A coil spring 9 serving as a biasing means is interposed between the F contact fitting 5 of the current limiting element unit 3 and the lower electrode fitting 7 so as to electrically connect them. The contact pressure between each current-limiting element in the element unit 3 is ensured, and the current-limiting element unit 3
The upper contact fitting 4 is press-fitted to the upper electrode fitting 6.

A pair of closed foam insulating elastic materials 10 and 11 are formed into a ring shape from closed foam rubber such as EPDM (ethylene-E1-pyrene diene copolymer), and are housed inside the upper and lower ends of the voltage-resistant insulating cylinder 1. The insulating jacket 12 is made of the above-mentioned EPDM rubber or the like and is made of the pressure-resistant insulating cylinder 1 and both l! The outer peripheral surfaces of the electrode fittings 6 and 7 are molded to be airtight, and a plurality of ribs 13 are provided on the outer peripheries. Inner insulation W! Reference numeral 114 is provided between the voltage-resistant insulating tube 1 and the current-limiting element unit 3, and when the insulating jacket 12 is molded, the EPD
It is formed by filling an insulating material such as M rubber into the inside of the pressure-resistant insulating cylinder 1 through the pressure release hole 2 .

Next, a method for manufacturing the lightning arrester constructed as described above will be explained with particular reference to FIG. 2.

Now, when manufacturing this lightning arrester, first, with the upper closed foam insulating elastic material 10 housed inside the upper end of the voltage-resistant insulating cylinder 1, the upper electrode fitting 6 is fitted to the upper end of the voltage-resistant insulating cylinder 1. Fix with adhesive 8.

Next, the current limiting element unit 3 is housed in the voltage-resistant insulation m1 from the lower end side, and the upper contact fitting 4 at the upper end thereof is engaged with the upper electrode fitting 6. Further, a lower independent foam insulating elastic material 11 is housed inside the lower end of the voltage-resistant insulating cylinder 1 . Then, while pressing the lower electrode fitting 7 with the coil spring 9 interposed in the non-contact fitting 5 on the lower end side of the current limiting element unit 3,
The lower electrode fitting 7 is fitted onto the lower end of the voltage-resistant insulating cylinder 1 and fixed with an adhesive 8.

Thereafter, when this assembly is placed in a mold (not shown) and the forming part is evacuated prior to molding the insulating jacket 12, the space between the voltage-resistant insulator n1 and the current-limiting element unit 3 is filled. A certain amount of air is released from the pressure relief hole 2 of the pressure-resistant insulating tube 1, and the space becomes negative pressure, and as a result, the closed-cell foam insulating elastic material 1 housed inside both the upper and lower ends of the pressure-resistant insulating tube 1
0.11 expands in volume. Therefore, due to the volumetric expansion of the closed foam insulating elastic material 10.11, the space between the voltage-resistant insulation IJ1 and the current limiting element unit 3 becomes narrower, and the air layer remaining in the space can be minimized.

Then, in this state, a material such as EPDM rubber is injected into the mold and the insulating jacket 12 is molded on the outer peripheral surfaces of the voltage-resistant insulating tube 1 and both electrode fittings 6.7. A material such as rubber is injected into the space between the voltage-resistant insulation tube 1 and the current-limiting element unit 3 through the pressure relief hole 2, and the inner insulation 814 is filled and formed in the space. At this time, the closed foam insulating elastic material 10 which was in a volumetrically expanded state
Since ゜11 is compressed into a flat shape as shown in Figure 1,
As the flattening shrinks, the slight amount of remaining air is also attracted to the contracted portion and concentrated there. Therefore,
The amount of air mixed into the inner insulating layer 14 can be kept to a minimum, and air can be prevented from remaining between the voltage-resistant insulating tube 1 and the current-limiting element unit 3 to ensure sufficient insulation. can.

Moreover, the manufacturing process is extremely easy because all that is required is to arrange the ring-shaped closed foam insulating elastic materials io and 1i within the voltage-resistant insulating cylinder 1.

(Effects of the Invention) Since the lightning arrester of the present invention is configured as explained above, it is possible to ensure sufficient insulation between the voltage-proof insulating cylinder and the current-limiting element unit, and to improve reliability. It has the excellent effect of being able to

Further, according to the method for manufacturing a lightning arrester of the present invention, the above-mentioned lightning arrester can be easily manufactured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a lightning arrester embodying the present invention, and FIG. 2 is a sectional view showing the lightning arrester in a state in the middle of manufacturing. DESCRIPTION OF SYMBOLS 1... Voltage-proof insulation tube, 2... Pressure relief hole, 3... Current-limiting element unit, 6.7-... Electrode fitting, 9... Coil spring as biasing means, 10.11- ...Closed foam insulating elastic material, 12...Insulating jacket, 14...Inner insulating layer. Patent applicant Nippon Insulator Co., Ltd. Agent Patent attorney On 1) Hironobu Figure 2

Claims (2)

[Claims] 1. A voltage-resistant insulating cylinder having a pressure relief hole, a current-limiting element unit housed inside the voltage-resistant insulating cylinder and mainly made of zinc oxide or the like having non-linear voltage-current characteristics, and both upper and lower ends of the voltage-resistant insulating cylinder. a pair of electrode fittings fitted and fixed to the electrode fittings, a ring-shaped closed foam insulating elastic material housed inside both upper and lower ends of the voltage-resistant insulating cylinder, and an airtight molded material on the outer peripheral surfaces of the voltage-proof insulating cylinder and the electrode fittings. 1. A lightning arrester comprising: an insulating jacket; and an inner insulating layer filled into the inside through a pressure release hole of a voltage-resistant insulating cylinder when the insulating jacket is molded. 2. An electrode fitting is fitted and fixed to one end of the voltage-resistant insulating cylinder, a ring-shaped closed-foam insulating elastic material is housed inside one end of the voltage-resistant insulating cylinder, and a current-limiting element unit is housed inside the voltage-resistant insulating cylinder. Then, one end thereof is engaged with the electrode fitting, and a ring-shaped closed foam insulating elastic material is similarly accommodated inside the other end of the voltage-proof insulating cylinder, while the other end of the current limiting element unit is In order to fit and fix another electrode fitting, and further to form an insulating jacket on the outer peripheral surfaces of the voltage-resistant insulating tube and both electrode fittings, and an inner insulating layer between the current-limiting element unit and the voltage-proof insulating tube, respectively. , Vacuum is drawn between the forming part of the insulating mantle, the current limiting element unit, and the voltage-resistant insulating cylinder to expand both the closed foam insulating elastic materials, and then injecting an insulating material to mold the insulating mantle. A method for manufacturing a lightning arrester, comprising injecting an insulating material between the voltage-resistant insulating cylinder and the current-limiting element unit through a pressure relief hole formed in the voltage-resistant insulating cylinder, and compressing both the closed-cell foam insulating elastic materials.