JPH0970132A - Power cable connecting part and manufacturing method thereof - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To eliminate the cause of dielectric breakdown by preventing the existence of an interface with an epoxy resin insulator and the absence of electrically harmful voids, and at the same time, to prevent the electrode from insulating with an epoxy resin The purpose is to be able to confirm the adhesion to the body. SOLUTION: A conductive paint 5 is applied to an inner portion of an epoxy resin insulator 3 in an epoxy unit 1 forming a part of a prefabricated joint, and the conductive paint serves as an electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cable connecting part and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, tape type joints (TJs), tape type mold joints (TMJs), extrusion mold joints (EMJs) and prefabricated joints (PJs) are known as methods for connecting power cables. Of these, the prefabricated joint (PJ) is, for example, as shown in FIG. 4, the ends of the left and right cables 21L and 21R are stripped off, and the cable conductors are exposed and abutted to connect the cable conductors to each other. ing.

An epoxy unit 27 composed of an epoxy resin insulator 25 having an electrode 23 embedded inside is covered on the outer periphery of this connecting portion, and a conical rubber is engaged with the left and right conical tapered surfaces of the epoxy unit 27. The mold stress cones 29L and 29R are fitted from the left and right, and the interfaces of the cables 21L and 21R and the epoxy unit 27 are brought into close contact with each other for insulation.

As described above, the prefabricated joint (PJ) is roughly divided into the cables 21L and 21R, the epoxy unit 27, and the rubber mold stress cones 29L and 29.
It consists of three parts, R. Among them, the epoxy unit 27 is the epoxy resin insulator 2 having the electrode 23.
5, the electrode 23 is made of a metal such as aluminum (Al) or copper (Cu), and the epoxy resin insulator 25 is made of an epoxy cured product containing an inorganic filler.

As shown in FIG. 5, the epoxy unit 27 uses a mold 31 composed of a bottom plate 31D and a plurality of side plates 31S, and a core 33 in which the electrode 23 is previously mounted in the mold 31. The side plate 3 of the mold 31
The epoxy resin 35 is injected between the 1S and the core 33, the epoxy resin 35 is cured, and then the epoxy resin 35 is removed from the mold 31.

[0006]

By the way, since the above-mentioned conventional epoxy unit 27 is composed of the metal electrode 23 and the epoxy resin insulator 25 obtained by curing the epoxy resin 15, there is a different interface. Metal electrode 23
Due to the difference in the coefficient of thermal expansion between the epoxy resin insulator 25 and the epoxy resin insulator 25, there is a drawback in that voids are formed at the interface without sticking to each other, causing dielectric breakdown.

The conventional epoxy unit 2 described above is also used.
In the manufacturing method of 7, the core 33 having the metal electrode 23 attached is set in the mold 31, and then the epoxy resin 35 is added.
Since it was injected, it was not possible to confirm whether or not the interface between the electrode 23 and the epoxy resin 35 was adhered to each individual unit.

An object of the present invention is to eliminate the cause of dielectric breakdown by eliminating the interface with the epoxy resin insulator and the absence of electrically harmful voids, and at the same time to prevent the electrode and the epoxy resin insulator. An object of the present invention is to provide a power cable connecting part and a method for manufacturing the same, which can confirm the adhesion with the power cable connecting part.

[0009]

In order to achieve the above object, the power cable connecting component of the present invention is such that a conductive paint is applied to an inner portion of a resin insulator in an epoxy unit forming a part of a prefabricated joint, This conductive paint is used as an electrode.

Further, according to the method of manufacturing a power cable connecting part of the present invention, a core having an electrode part mold is set in a mold, and an epoxy resin is injected between the mold and the core to cure the epoxy. Then, apply the conductive paint to the electrode part of the epoxy cured product with the mold, core and electrode mold removed,
The conductive paint is used as an electrode.

The conductive paint has a conductivity of 10 ⁵
It is preferable that the paint is Ω · cm or less.

With the power cable connecting component and the manufacturing method thereof as described above, by applying the conductive paint to the inner portion of the epoxy unit, the embedded electrode is eliminated, so that the interface with the epoxy resin insulator is eliminated. Not present, no electrically harmful voids. Therefore, the cause of dielectric breakdown disappears. Also, after manufacturing the epoxy resin insulator, apply conductive paint to the inner part,
Since the electrodes are used, the adhesion between the electrodes and the epoxy resin insulator can be confirmed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the epoxy unit 1 according to the present invention. This epoxy unit 1 has the same shape as a conventional epoxy unit, and is an epoxy resin insulator (cured product) obtained by curing an epoxy resin.
It consists of three. The inside of the epoxy resin insulator 3 (hatched portion in FIG. 1) is coated with a conductive paint 5 and the conductive paint 5 is used as an electrode for the epoxy unit 1.
Is configured.

The conductive paint 5 is preferably a paint containing metal fine particles such as silver (Ag) and copper (Cu) or carbon particles and having an electric conductivity of 10 ⁵ Ω · cm or less.

As described above, since the conductive paint 5 is applied to the inner portion of the epoxy insulator 3 to form an electrode, the conventional embedded electrode (metal) is eliminated, so that the interface with the epoxy insulator 3 exists. Without, there are no electrically harmful voids. Therefore, the cause of dielectric breakdown disappears.

As a manufacturing method for manufacturing the epoxy unit 1, as shown in FIG. 2, a metal mold 9A for an electrode portion made of metal is placed in a mold 7 composed of a bottom plate 7D and a plurality of side plates 7S. The jointed core 11 is set, and the electrode part mold 9B is set on the bottom plate 7D. Further, after the electrode section mold 9C is set on the upper side and the epoxy resin 13 is injected between the side plate 7S of the mold 7 and the core 11, the epoxy resin 13 is cured when a certain time has elapsed. When the mold 7, the core 11 and the electrode molds 9A, 9B and 9C are removed from the cured epoxy resin 13, the epoxy resin insulator 3 (cured epoxy resin) as shown in FIG. 1 is obtained.

Then, as shown in FIG. 1, the epoxy unit 1 can be obtained by applying a conductive paint 5 having an electric conductivity of 10 ⁵ Ω · cm or less to the inner portion of the epoxy resin insulator 3. it can. In this way, after the resin 13 is cured to form the epoxy resin insulator 3, the conductive paint 5 is applied to the inner portion and the conductive paint is formed as an electrode, so that the electrode 5 and the epoxy resin 3 are bonded together. Can be confirmed.

For example, as shown in FIG. 3, the cable conductor 1 in which the ends of the cables 15L and 15R are stripped off
7 was connected to the electrode made of the conductive paint 5 and the conductor connection tube 19 was connected, and the AC withstand voltage was measured. The results shown in Table 1 were obtained. Table 1 also shows the results of measuring the AC withstand voltage by using a conventional buried metal as an electrode or a conventional buried metal mold coated with a conductive coating as an electrode as a comparative example.

[0020]

[Table 1] As can be seen from the results shown in Table 1, this example provided better AC withstand voltage values than Comparative Examples 1 and 2.

As described above, by applying the conductive paint 5 to the inside of the epoxy resin insulator 3 in the epoxy unit 1 to form an electrode, there is no interface between the metal electrode and the epoxy resin insulator 3. , No void is generated due to peeling. Since no metal electrode is used, heat shrinkage of the epoxy resin insulator (epoxy cured product) 3 due to heat cycle or the like is not added.

First, the epoxy insulator (hardened epoxy) 3
After that, the conductive paint 5 is applied to the inner part of the epoxy resin insulator 3 to form an electrode. Therefore, the inner part of the epoxy resin insulator 3 (the part to which the conductive paint 5 is applied) should be electrically and mechanically treated. Appropriate measures can be taken even if there are harmful foreign substances or protrusions.

The present invention is not limited to the example of the above-described embodiment, but can be appropriately modified. For example, instead of the example of the present embodiment, which uses an epoxy cured product and uses a metal as an electrode, a conductive paint can be used as an electrode.

[0024]

As will be understood from the above embodiments, according to the present invention, an epoxy resin insulator is formed by applying a conductive paint to the inside of the epoxy resin insulator to form an electrode. Since there is no interface with and there are no electrically harmful voids, the cause of dielectric breakdown can be eliminated.

Further, after the epoxy resin insulator is manufactured, a conductive paint is applied to the inner portion of the epoxy resin insulator to form the electrode, so that the adhesion between the electrode and the epoxy resin insulator can be confirmed.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an epoxy unit of the present invention.

FIG. 2 is an explanatory view illustrating a manufacturing method of the present invention.

FIG. 3 is an explanatory diagram for measuring AC withstand voltage using the epoxy unit of the present invention.

FIG. 4 is an explanatory view showing a conventional prefabricated joint.

FIG. 5 is an explanatory diagram illustrating a method for manufacturing an epoxy unit that constitutes a part of a conventional prefabricated joint.

[Explanation of symbols]

 1 Epoxy Unit 3 Epoxy Resin Insulator (Epoxy Cured Product) 5 Conductive Paint (Electrode) 7 Mold 9A, 9B, 9C Metallic Mold 11 Core 13 Epoxy Resin

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroaki Okuyama 42-1 Shintomicho, Futtsu City, Chiba Prefecture Fujikura Futtsu Factory

Claims (2)

[Claims] 1. A power cable connecting component characterized in that a conductive paint is applied to the inside of an epoxy resin insulator in an epoxy unit forming a part of a prefabricated joint, and the conductive paint is used as an electrode. 2. A mold, a core and an electrode part after setting a core provided with a mold for an electrode part in a mold and injecting an epoxy resin between the mold and the core to form an epoxy cured product. A method for producing a power cable connecting component, characterized in that a conductive paint is applied to the inside of the epoxy cured product from which the mold has been removed, and the conductive paint is used as an electrode.