JPH06215656A - Method for manufacturing composite insulator - Google Patents

Abstract

PURPOSE:To form an interface strongly and integrally, and exhibit effectively excellent creeping insulating strength of a casing body by forming a casing body inside part on a core body whose resin is put in an unhardened condition, and molding a casing body outside part after the core body resin is hardened. CONSTITUTION:An unvulcanized tape or sheet is wound round a core body 1 whose resin is unhardened, or an unvulcanized tube is inserted, and reinforcing winding is also applied by a die separable tape or sheet. Next, it is heated and vulcanized, and an inside part 21 of a casing body 2 is formed, and the resin of the body 1 is hardened by heat at this vulcanization time. An unvalcanized material is added to the part 21 formed in this way, and this is clamped by a die, and the die is heated, and the material is vulcanized, and is formed in a prescribed shape, and a core 3 is pulled out thereafter. Thereby, since an interface between the body 1 and the part 21 can be adhered firmly by hardening the resin of the body 1, interfacial dielectric breakdown on this interface can be prevented. Since the interface between the part 21 and an outside part 22 of the body 2 is also adhered excellently, excellent creeping insulating strength on an outside surface of the body 2 can be exhibited effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite insulator, which is useful for producing a synthetic resin sleeve.

[0002]

2. Description of the Related Art A porcelain trocar has the disadvantages that it is easily ruptured by the impact of lightning surges, it is heavy, and it is difficult to manufacture. Attention has been paid to a sleeve formed of an organic polymer material such as.

Among these organic polymer sleeves, the rubber sleeve is excellent in creep resistance, particularly in tracking resistance and weather resistance, but has a problem in load bearing strength.
Therefore, there has been proposed a sleeve tube in which an outer cover containing rubber as a main component is formed on a fiber-reinforced resin core.

[0004]

If the interface between the core body and the outer cover is peeled off due to the thermal stress due to the change in ambient temperature, the creeping insulation strength of the surface of the fiber reinforced resin core body is increased. It is low, and because the creepage insulation distance at the interface is shorter than the creepage insulation distance at the outer surface of the jacket, dielectric breakdown occurs at the peeling interface, effectively exhibiting excellent creeping insulation strength on the outer surface of the jacket. I can't let you do it. Therefore, in the above-mentioned composite sleeve, strong adhesive integration between the fiber-reinforced resin core and the outer jacket is essential.

Conventionally, as a method for integrating the core body and the outer cover, a heat shrink type outer cover having a hot-melt adhesive applied to the inner surface is covered on the core, and the outer cover is thermally contracted. Method, a method of press-fitting a jacket having an inner diameter slightly smaller than the outer diameter of the core into the core coated with silicone grease, an adhesive is applied to the core, and a jacket is formed on the outer surface of the core. There has been proposed a method of pressure-molding using.

However, in the first and second methods, there is a limit to the thickness of the outer casing, and the tensile stress remains applied to the outer casing, and cracks may occur depending on the material of the outer casing and environmental conditions. Are disadvantageous in that the adhesive strength is likely to occur and the adhesive strength cannot be expected so much. Further, in the third method, the adhesive applied to the core body easily flows out from the interface due to the molding pressure of the jacket, and it is difficult to strongly integrate the interface.

An object of the present invention is to manufacture a composite sleeve having an outer jacket having excellent creeping insulation strength on a core made of a fiber-reinforced cured resin, which enables strong integration of the interface, and It is an object of the present invention to provide a method for producing a composite insulator capable of producing a composite sleeve capable of effectively exhibiting excellent creeping insulation strength.

[0008]

A method for producing a composite insulator according to the present invention is a method for forming a jacket having a shape having a creeping insulation strength superior to that of a core on a fiber-reinforced cured resin core. , The resin is uncured, the inner part of the outer cover is formed on the core, the resin of the core is cured, and then the outer part of the outer cover is molded. A composition containing rubber as a main component can be used as the material of the inner part of the body and the material of the outer part of the outer jacket, and a thermoplastic resin is added to both the material of the inner part of the outer jacket and the material of the outer part of the outer jacket. It is preferable.

[0009]

The hardening resin of the core is hardened when the inner portion of the outer cover is formed. In this case, the thickness of the outer casing can be reduced, and the molding pressure of the inner portion of the outer casing can be sufficiently lowered, so that the resin can be prevented from flowing out before the resin is cured, and the core body and the inner portion of the outer sheath can be prevented. The interface of is strongly integrated by curing the resin.

Further, since the inner part and the outer part of the outer cover are made of the same material, and the interface is well integrated, and the interface between the materials having excellent creeping insulation strength, the interface is also materially concerned. The creeping insulation strength of is increased.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are explanatory views showing an embodiment of the present invention. 1 (a) and 1 (b)
In the above, 1 indicates a fiber-reinforced cured resin core, which is tubular, and as the fiber, inorganic fiber such as glass fiber, synthetic resin fiber or the like can be used. Reference numeral 2 denotes an outer jacket having a shape having a creeping insulation strength superior to that of the core body 1. 21 is the inner part of the outer casing 2,
Reference numerals 22 denote outer portions, and the material of each of these portions is a material having higher creeping insulation strength and weather resistance than the core body 1, such as ethylene-propylene-diene rubber.
Compositions based on-may be used. 3 is a core.

In order to manufacture a composite insulator (composite sleeve) according to the present invention, in FIG. 1 (a), an unvulcanized tape or sheath is placed on a core body 1 in which the resin is uncured. Wrapped around or insert an unvulcanized tube, and then release the tape.
The inner part 21 of the outer cover is molded by applying a press-winding of a pump or a sheet and then heating and vulcanizing, and the resin of the core body 1 is cured by the heating during this vulcanization.

During the above-mentioned vulcanization, the thermal expansion of the vulcanizate is suppressed due to the pressing layer and pressure is generated, so that the vulcanizate can be vulcanized and molded by voidless. It is also possible to use a presser die instead of the releasable tape or sheet presser winding.

When the inner part 21 of the jacket is molded in this way, in FIG. 1B, unvulcanized material is added to the molded inner part 21 of the jacket and this is clamped with a mold. (Adding material by wrapping unvulcanized tape, tightening this with a mold, or filling the mold with a block of unvulcanized material,
This mold is set on the inner part of the outer cover), the mold is heated to vulcanize the material and mold it into a predetermined shape.
The core 3 is removed and the molding of the composite insulator is completed.

In the above, in order to further strengthen / increase the adhesive strength at the interface between the inner part 21 and the outer part 22 of the outer cover, the material of each part is made of a thermoplastic resin such as ethylene-vinyl acetate copolymer. A polymer, an ethylene-ethyl acrylate copolymer, a styrene-isoprene block copolymer, a styrene-butadiene block copolymer, or the like can be added, and the interface can be heat-sealed.

When the material forming the inner part 21 of the outer cover is added by winding a tape or a sheet material, a tackifying resin can be added to the material to impart tackiness. .

An example of the material for the inner part of the jacket and the material for the outer part of the jacket used in the present invention is as follows:
It is as follows. [Composition of material for inner part of outer cover] 70 parts by weight of ethylene / propylene / diene rubber, ethylene ethyl acrylate
30 parts by weight of copolymer, 20 parts by weight of polyisobutylene,
50 parts by weight of clay, 1 part by weight of carbon black, 0.5 part by weight of heat and antioxidant, 3 parts by weight of dicumyl peroxide.

[Composition of material for inner part of outer cover] 70 parts by weight of ethylene / propylene / diene rubber, 30 parts by weight of ethylene ethyl acrylate copolymer, 30 parts by weight of magnesium hydroxide, 10 parts by weight of calcium carbonate, 1 part by weight of carbon black, 0.5 part by weight of heat and antioxidant, 3 parts by weight of dicumyl peroxide.

In the present invention, as shown in FIG. 2, the jacket 2 is divided into a cap portion 22 and a tubular portion 21, the tubular portion being the inner portion of the jacket, and the cap portion being outside the jacket. It can also be a part. In FIG. 2, reference numeral 1 is a fiber-reinforced cured resin core.

[0020]

As described above, in the method for manufacturing the composite insulator of the present invention, the outer body is divided into the inner portion and the outer portion, and the inner portion of the outer body is provided on the core body in which the resin is uncured. Since the resin of the core is cured while being molded, and the thickness of the inner part of the composite insulator is thin, the molding pressure of the inner part of the outer casing can be made sufficiently low to prevent the resin from flowing out before the resin cures. It can be prevented, and the interface between the core and the inner part of the jacket can be strongly adhered by curing the resin of the core, and the interfacial dielectric breakdown at this interface can be prevented.

Further, the interface between the inner part of the outer cover and the outer part of the outer cover can be adhered well because of the same material, and the creeping insulation strength of the materials of both parts is excellent, and the creeping insulation strength of the interface is good. Since it can be made higher in terms of material, it is possible to prevent interfacial dielectric breakdown at this interface. Therefore, it is possible to manufacture a composite insulator capable of effectively exhibiting excellent creeping insulation strength on the outer surface of the jacket.

[Brief description of drawings]

FIG. 1A is an explanatory view showing a forming step of an inner part of an outer jacket of the present invention, and FIG. 1B is an explanatory view showing a forming step of an outer part of the outer jacket.

FIG. 2 is an explanatory view showing an example of a composite sleeve produced by the present invention.

[Explanation of symbols]

 1 Fiber Reinforced Hardened Resin Core Body 2 Outer Body 21 Outer Body Inner Part 22 Outer Body Outer Part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Nakanishi 1-2-2 Shimohozumi, Ibaraki-shi, Osaka Prefecture Nitto Denko Corporation (72) Minoru Sonoda 1-2-1, Shimohozumi, Ibaraki-shi, Osaka No. Nitto Denko Corporation

Claims (3)

[Claims] 1. A method of molding a fiber-reinforced cured resin core body on the core body in which the resin is in an uncured state in a method of molding a sheath body having a shape having better creeping insulation strength than the core body. A method for producing a composite insulator, which comprises forming an inner part, curing a resin of a core, and then molding an outer part of the outer cover. 2. The method for producing a composite insulator according to claim 1, wherein the material of the inner part of the outer cover and the material of the outer part of the outer cover are compositions containing rubber as a main component. 3. The method for producing a composite insulator according to claim 2, wherein both the material of the inner part of the outer cover and the material of the outer part of the outer cover contain a thermoplastic resin.