JPH06310307A - Compact lightning arrester for indoor and outdoor use - Google Patents

Abstract

PURPOSE:To obtain a compact lightning arrester, for indoor and outdoor use, which is lightweight and not degraded electrically and mechanically even when it is exposed outdoors. CONSTITUTION:A compact lightning arrester for indoor and outdoor use is constituted of a plurality of stacked nearly cylindrical ZnO elements 1, of heat- resistant tapes 11 pasted on side faces of parts in which the individual ZnO elements 1 are polymerized, of an upper metal fitting 8 and a lower metal fitting 9 which are arranged on both the upper and lower end parts at the ZnO elements 1, of FRP rods 3 as strength members which are interposed between the upper and lower metal fittings and which fix both metal fittings and of a housing member 13 which is situated at the circumference of the ZnO elements 1, the upper and lower metal fittings and the strength members, whose main material is a rubber-based polymer material and which is applied by a molding means. The housing member adopts an EPDM rubber as a main material, and it is obtained in such a way that a material kneaded with a material in which a vulcanizing agent, a vulcanizing auxiliary, a softening agent, carbon black, a flame retarder, an age resistor and a filler have been mixed with the main material is molded by an injection molding means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact lightning arrester for both indoor and outdoor use, which uses a voltage non-linear type resistor whose main component is zinc oxide (hereinafter abbreviated as ZnO).

[0002]

2. Description of the Related Art As a lightning arrester using a voltage non-linear resistor having ZnO as a main component, the structures shown in FIGS. 2 and 3 have been conventionally known. The example shown in FIG. 2 is an example of a mold-type indoor lightning arrester, in which a plurality of substantially columnar ZnO elements 1 are stacked in a central hole, and an epoxy resin 2 having an insulating property is provided on the outside thereof. It has a structure in which electrodes (not shown) are arranged above and below by molding.

The ZnO element 1 has a high voltage nonlinearity,
Since it has a composition and composition with small heat loss and can absorb a large amount of energy as compared with a general surge absorber for weak electric current, it is used as a resistor for a lightning arrester or the like.

On the other hand, a lightning arrester used by being directly exposed to the outdoors is constructed by stacking a plurality of substantially cylindrical ZnO elements 1 similar to those shown in FIG. 2 in a central hole as shown in FIG. The FRP (fiber reinforced plastic) rod 3 and the support member 4,
5 is used for fixing, and a porcelain porcelain insulator tube 6 is arranged around it. Then, elastic members 7 such as disc springs are vertically arranged.
The upper metal fitting 8 and the lower metal fitting 9 are arranged with the intervening. The elastic member 7 is inserted for the purpose of preventing shape deformation due to bending or pulling force applied from the outside, and for preventing contact failure between the electrode and the ZnO element 1 due to expansion and contraction due to temperature change. Has been done.

[0005] As an insulating material composition for forming an insulator, an insulator tube, a spacer, a bushing, etc., which is directly exposed outdoors by such a high-voltage device, examples described in the following technical documents are known.

(1) Electrical and Electronic Advanced Technology Exhibition and Technical Seminar: "Current State of Outdoor Polymer Insulators" Watanabe, Central Research Institute of Electric Power, Yokosuka Research Center
Takahashi et al. (2) EIM-90-3 “Long-term properties of polymers for outdoor insulators” NGK Kunieda, Shinobuku, Nakai

[0007]

However, in such a lightning arrester using a conventional ZnO element, the epoxy resin 2 adopted in the example shown in FIG. 2 has a low specific gravity and leaks to the outside including a cap-shaped portion. Although it has the advantage of having a high degree of freedom in designing in determining the distance, it has low tracking resistance, that is, low electrical resistance when conductive liquid such as rainwater adheres to the surface when voltage is constantly applied, There is a problem that hydrogen in hydrocarbons constituting the molecule of the epoxy resin is released and conductive carbon is formed on the surface of the resin to impair the insulating property.

Further, the strain generated by the difference in thermal expansion between the ZnO element and the epoxy resin is increased on the low temperature side, and as a result, "cracking" of the epoxy resin occurs or ZnO
There is a problem in that the performance as a lightning arrester deteriorates because the epoxy resin flows into an interface that requires electrical conduction when a large number of elements are laminated and is cured.

On the other hand, the porcelain used as the porcelain tube 6 in the example shown in FIG. 3 has the advantage that it has a large track record of use because it does not deteriorate electrically or mechanically even if it is directly exposed to the outdoors. However, this porcelain has a large specific gravity, so that the product itself becomes heavy and the strength of the steel tower is limited, and it is difficult to make it compact and beautify. Also, because the porcelain itself is hard and brittle, the insulator's shade is broken by the impact of electrical energy during an air flash on the outside of the insulator, causing the parts to fall from the steel tower and the ZnO element to be removed. The problem with the internal porcelain insulator is that the air in the gap between the porcelain and the porcelain may expand and explode due to the energy caused by penetrating the element or flashing outside the element that occurs when absorbing an excessive lightning surge. There is a point.

Further, since there is a gap between the ZnO element and the porcelain tube, there is a drawback that the insulation property is likely to deteriorate due to internal dew condensation.

Therefore, the present invention solves the problems of the conventional lightning arrester for indoor and outdoor use mainly composed of ZnO elements, and is light in weight, and is electrically and mechanically deteriorated even when exposed to the outdoors. The purpose is to obtain a compact lightning arrester that can be used both indoors and outdoors.

[0012]

In order to achieve the above-mentioned object, the present invention has a substantially cylindrical ZnO element having a plurality of laminated layers and a heat resistance attached to the side surface of a portion where each ZnO element is polymerized. A tape, an upper metal fitting and a lower metal fitting arranged at both upper and lower ends of the ZnO element, a strength member for fixing the both metal fittings interposed between the upper metal fitting and the lower metal fitting, and the ZnO element and the upper and lower metal fittings and the strength member. A compact lightning arrester for indoor / outdoor use is provided, which is composed of an outer covering member which is surrounded by a molding material and is mainly made of a rubber-based polymer material.

The outer cover member employs EPDM rubber as a main material, and a material in which a vulcanizing agent, a vulcanization aid, a softening agent, carbon black, a flame retardant, an antiaging agent and a filler are mixed with the main material. Use the kneaded material. Also, E as the main material
Aluminum hydroxide is used as a filler to be added to PDM rubber, a halogen-based compound and an antimony-based compound are used as flame retardants, and these kneaded products are molded into a jacket material by injection molding means.

[0014]

According to the present invention, the lightning arrester thus obtained is lightweight and compact, and is not deteriorated even if it is exposed outdoors for a long period of time. By adopting the EPDM rubber as the material, the degree of freedom in design is high in determining the outer leakage distance including the shaded portion, and the tracking resistance is kept good. Further, mechanical strength is guaranteed by a strength member fixed by being interposed between the upper metal member and the lower metal member, and further, the mechanical strength is ensured by the outer member and the Z member.
The effect that there is no strain generated due to the difference in thermal expansion from the nO element is obtained.

The heat-resistant tape attached to the superposed portion of the ZnO element eliminates the risk of the outer jacket member flowing into the interface, and there is no gap between the ZnO element and the outer jacket member. There is provided a compact lightning arrestor that can be used both indoors and outdoors without any fear of deterioration of insulation performance and expansion of air in the gap.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an indoor / outdoor compact lightning arrester according to the present invention will be described in detail below with reference to the accompanying drawings, in which the same reference numerals are given to the same components as the conventional components.
In the present embodiment, the characteristics of the epoxy resin, that is, the specific gravity is light, the design freedom is high in determining the outer leakage distance including the shade portion, and the characteristics of the porcelain,
In other words, the main aim is to obtain a molded lightning arrester that has the advantage of not causing electrical or mechanical deterioration even if it is directly exposed to the outdoors.

As a main material of the outer covering member, Teflon,
Whether silicone rubber or EPDM rubber was selected was examined for compatibility. Both of these materials are light in weight and have excellent tracking resistance, and hydrogen of hydrocarbons constituting the molecule is not desorbed or conductive carbon is not formed on the surface. It is characterized by the occurrence of strain due to the difference in expansion coefficient and the absence of "cracking" that accompanies this strain, and is a candidate as a main material.

As a result of further study, it is necessary to perform integral molding or injection molding in order to achieve integration with the ZnO element by the molding means, and it is required that the material be moldable by mold casting. To be done. From this viewpoint, Teflon is excluded.

When the remaining silicone rubber and EPDM rubber were examined, it was found that, on the one hand, which is a material that can be molded by mold casting, both have insulating properties at the interface that requires electrical conduction when ZnO elements are laminated. There is a problem that high polymer with high flow rate will flow and harden, reducing the performance as a lightning arrester, and both materials have strong rubber-like properties, so the material itself cannot guarantee the mechanical strength as an insulator. There is a problem.

In view of the above, in this embodiment, EPDM rubber is adopted as the main material, and the main material is vulcanizing agent, vulcanization aid, softening agent, carbon black, flame retardant, anti-aging agent shown in Table 1. The material which mixed the agent and the filler was adopted.

[0021]

[Table 1]

The EPDM rubber used as the main material is ethylene propylene diene monomer rubber (Ethylen Propyl
ene Diene Monomer Rubber, hereinafter abbreviated as EPDM rubber), which is a general term for compounds having two conjugated double bonds. Generally, a rubber-like copolymer of ethylene and propylene is called EPM. The EPDM rubber has a polymer and an unsaturated group in its side chain.
Incidentally, these may be collectively referred to as EPR (ethylene propylene rubber).

At the time of execution, Esprane 600 manufactured by Sumitomo Chemical Co., Ltd. was used as the EPDM rubber at 100 phr, and as a filler, 100 phr of the representative aluminum hydroxide manufactured by Shower Denko's Showa Denko series was used.

Aluminum hydroxide used as a filler has the features of excellent outdoor insulation resistance and flame retardancy. By making both the above two components 100 phr, it becomes the center of characteristics for improving the insulation resistance and the tracking resistance, but in this example, 2.5 phr of peroximone F-40 was used as a vulcanizing agent, Zinc white No. 3 was used as a vulcanization aid at 5 phr, stearic acid was used as a softening agent at 1 phr, and HAF black was used at 2 phr as a carbon black for improving weather resistance.

Further, as a halogen-based compound as a flame retardant, 15 phr of bromine compound decabrom diphenyl ether (frame cut 110R manufactured by Tosoh Corporation) and 15 phr of antimony trioxide (ATOX-S manufactured by Nippon Seiko Co., Ltd.) were used as an antimony compound. did. As an anti-aging agent, 0.5 phr of Antigen RD, MB of Antigen
Was used at 2.0 phr. Stearic acid has the effect of enhancing the releasability at the time of molding, and a vulcanizing agent and a vulcanization aid were added to vulcanize the compound and to increase the strength.

The above-mentioned halogen-based compound brings about an effect of suppressing combustion by overheating or a gas generated at the time of combustion reacting with excited atoms / atomic groups. Further, the antimony-based compound promotes dehalogenation reaction and melts itself. Has the effect of blocking the oxygen required for combustion, and the flame retardancy of the molded product is enhanced.

The addition of 2.5 phr of the vulcanizing agent in Table 1 means that the vulcanizing agent is added in an amount of 2.5 parts by weight based on 100 parts by weight of EPDM rubber.

Further, Table 1 shows various characteristic values of the injection molding composition having the above blending ratio. That is, the dielectric constant was 3.5, the tensile strength (kg / mm ² ) was 0.5, the tensile elongation at break (%) was 200, and the tracking resistance (inclined plate method) was 300 min or more.

Next, a specific structure and manufacturing means of the lightning arrester according to this embodiment will be described with reference to FIG. Reference numeral 1 in the figure denotes a substantially columnar ZnO element in which a plurality of ZnO elements 1 are stacked, and in the illustrated example, three ZnO elements 1 are stacked and arranged. Next, the heat-resistant tape 1 is attached to the side surface of each ZnO element 1 where the superposition occurs.
Wrap 1 and stick. In this embodiment, the heat resistant tape 11 is made of polyimide.

Next, the upper metal fitting 8 and the lower metal fitting 9 are arranged on both upper and lower ends of the ZnO element 1, and a flange member 8a, 9a protruding laterally from the upper metal fitting 8 and the lower metal fitting 9 serves as a strength member. The FRP rod 3 is interposed and fixed with the nut 12. Beforehand F
The RP rod 3 is coated with an interfacial adhesive for enhancing the adhesiveness with the EPDM rubber in the subsequent step, and the nut 12 is also coated with a fixing adhesive for enhancing the adhesiveness with the FRP rod 3. is there.

As described above, the ZnO element 1 and the upper and lower metal fittings 8,
9 was fixed using an FRP rod 3 and placed in a mold for injection molding in which EPDM rubber was flowed, and aluminum hydroxide, a vulcanizing agent, and a vulcanization aid were previously added to the Esplen 600 using a kneader (kneader). The kneaded material containing the agent, the flame retardant, the carbon black, the softening agent, and the antiaging agent is injection-molded, and thereafter, a curing treatment is performed at about 150 ° C. for 3 minutes to form the jacket member 13. The heat resistant tape 11 is a ZnO element 1
It has the function of preventing the kneaded material from flowing into the polymerized portion and hardening.

As is well known, injection molding means is a method in which a molding material is heated and melted in an injection cylinder, and the fluidized molding material is press-fitted into a mold closed tightly by an injection plunger or a screw to mold it. Is.

The lightning arrester manufactured by such means is light in weight, which is a characteristic of the product obtained by the conventional molding means, and is electrically and mechanically exposed even when it is directly exposed to the outdoors, which is a characteristic of the porcelain insulator. It has a performance that combines the property of not deteriorating.

[0034]

As described in detail above, according to the compact arrester for indoor / outdoor use according to the present invention, the obtained arrester is lightweight and compact, and is not deteriorated even when exposed to the outdoors. The EPDM rubber, which is a polymer material, is used for the outer cover member, which has a high degree of freedom in design and is highly resistant to tracking. The property is good, and there is no fear that the insulating property will be impaired due to the adhesion of rainwater or the like under the applied voltage.

Further, the strength member fixed by being interposed between the upper metal member and the lower metal member enhances the strength against pulling and bending, so that the mechanical strength of the conventional porcelain insulator can be guaranteed. Furthermore, since there is no strain caused by the difference in thermal expansion between the jacket member and the ZnO element, there is no “cracking” of the jacket member.
Does not occur, and the heat-resistant tape attached to the superposed portion of the ZnO element eliminates the risk of the outer jacket member flowing into the interface of the ZnO element, and the performance as a lightning arrester is maintained well.

Since there is no gap between the ZnO element and the outer cover member, there is no fear of deterioration of the insulation due to internal dew condensation, and the air in the gap may expand and explode due to the energy caused by the flashover. It is possible to obtain a compact arrester that can be used both indoors and outdoors.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of an indoor / outdoor compact lightning arrester according to the present invention.

FIG. 2 is a cross-sectional view of essential parts showing an example of a conventional resin-molded arrester.

FIG. 3 is a cross-sectional view of a main part showing an example of a conventional outdoor lightning arrester.

[Explanation of symbols]

 1 ... ZnO element 3 ... FRP rod (strength member) 8 ... Upper metal fitting 9 ... Lower metal fitting 8a, 9a ... Flange part 11 ... Heat resistant tape 13 ... Coating member

Claims (5)

[Claims] 1. A substantially columnar ZnO element having a plurality of laminated layers, a heat-resistant tape adhered to a side surface of a superposed portion of each ZnO element, upper metal fittings arranged at upper and lower ends of the ZnO element, and A lower metal fitting, a strength member that is interposed between the upper metal fitting and the lower metal fitting to fix the both metal fittings, and a molding means using a rubber-based polymer material as a main material around the ZnO element, the upper and lower metal fittings, and the strength member. A compact lightning arrester for both indoor and outdoor use, which is characterized in that it is composed of an outer cover member attached by. 2. The outer cover member employs EPDM rubber as a main material, and a vulcanizing agent, a vulcanization aid, a softening agent, carbon black, a flame retardant, an antioxidant and a filler are mixed with the main material. The indoor / outdoor compact lightning arrester according to claim 1, wherein a material obtained by kneading the above material is used. 3. An aluminum hydroxide is used as a filler added to EPDM rubber as a main material, and a halogen compound and an antimony compound are used as flame retardants,
The compact lightning arrester for indoor / outdoor use according to claim 1, wherein the kneaded material is molded by injection molding means. 4. The indoor according to claim 1, 2 or 3, wherein decabrom diphenyl ether is used as a halogen-based compound as a flame retardant added to EPDM rubber as a main material, and antimony trioxide is used as an antimony-based compound.
Compact lightning arrestor for outdoor use. 5. The compact lightning arrester for both indoor and outdoor use according to claim 1, wherein a fiber-reinforced plastic rod is used as a strength member interposed between the upper metal fitting and the lower metal fitting to fix the both metal fittings.