JP2006033899A - Cable terminal connection part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable terminal connection part in which flashover performance is enhanced through a simple structure while decreasing the number of components. <P>SOLUTION: The cable terminal connection part comprises a polymer bushing 26, and a cable terminal 28. The polymer bushing 26 comprises a hard insulation tube 16 having a central conductor lead-out rod 12 and provided with a cable receiving opening 14 at the lower end, a polymer coating 20 provided on the outer circumference of the insulation tube 16 and having a large number of ribs 18 formed on the outer circumference while spaced apart in the longitudinal direction, and a supporting metal 24 having a flange 22 projecting outward from the circumferential surface of the insulation tube 16. The cable terminal 28 is fixed to the cable receiving opening 14 of the insulation tube 16. The polymer coating 20 is located above the supporting metal 24 and the cable receiving opening 14 is located below the supporting metal 24. The flange 22 of the supporting metal 24 has curved surface at the corner 30 of the outer surface and a nonpenetrating threaded hole 34 is made in the lower surface part 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cable termination connection using a polymer cannula, which is used in the air termination of a power cable.

  Conventionally, as a cable terminal connection portion using a polymer sleeve, there is a configuration as shown in FIG. In the figure, the conventional cable terminal connecting portion includes a polymer sleeve 26 to be described later, and a cable terminal portion 28 joined to the polymer sleeve 26. The polymer sleeve 26 is a hard insulating member having a conductor lead-out rod 12 having a conductor insertion hole 12a at the lower end and a cable receiving port 14 provided on the outer periphery of the conductor lead-out rod 12 and joining the cable terminal portion 28 to the lower end. It is comprised from the cylinder 16 and the polymer coating body 20 provided in the outer periphery of the insulating cylinder 16. FIG. The cable terminal portion 28 is attached to the cable receiving port 14 of the insulating cylinder 16 (see Patent Document 1).

  The insulating cylinder 16 is formed of a material having high mechanical strength, for example, a hard plastic resin such as epoxy resin or FRP, and the polymer cover 20 is a material having excellent electrical insulation performance, for example, a polymer insulating material such as silicon polymer. The conductor lead bar 12, the insulating cylinder 16, and the polymer cover 20 are integrally formed by a mold.

  The insulating cylinder 16 is connected to the large-diameter insulating cylinder 16a provided on the outer peripheral portion of the lower portion of the conductor extraction rod 12, that is, the outer peripheral portion corresponding to the conductor insertion hole 12a, and the large-diameter insulating cylinder 16a. A small-diameter insulating tube 16b provided on the outer peripheral portion of the portion excluding the tip of the rod 12 is provided, and a support fitting 24 is disposed at a continuous portion of the large-diameter insulating tube 16a and the small-diameter insulating tube 16b.

  The support fitting 24 is connected to a cylindrical portion 23 concentrically embedded in the lower portion of the insulating cylinder 16 with the conductor extraction rod 1 and a lower end portion of the cylindrical portion 23, and is provided outside the peripheral surface of the insulating cylinder 16. And a flange portion 22 protruding in the direction. A bottom metal fitting 40 is fixed to the lower end surface of the outer peripheral edge of the flange portion 22 by mounting bolts 42. Further, a cone-shaped cable receiving port 14 for receiving a stress cone of a cable terminal portion 28 to be described later is provided at the lower end portion of the large-diameter insulating tube 16a. It communicates with the hole 12a.

  The polymer cover 20 is provided on the outer peripheral portion of the small-diameter insulating cylinder 16 b, and a large number of flanges 18 are formed on the outer peripheral portion so as to be separated along the longitudinal direction of the polymer cover 20. As for the collar part 18, the large diameter collar part and the small diameter collar part are provided alternately. In the figure, reference numeral 46 denotes a protective fitting that is disposed on the outer peripheral portion of the large-diameter insulating cylinder 16a and whose upper end is attached to the lower surface of the flange portion 22 of the support fitting 24.

The above-described cable terminal connection portion is installed as follows.
First, the polymer sleeve 26 is attached to the support frame 44 via the support lever 38 disposed on the lower surface of the bottom metal fitting 40. Similarly to the conventional cable terminal portion, a stress cone 50 is attached to the outer periphery of the cable insulator 48 exposed by stripping the cable terminal, and a known conductor terminal 54 is attached to the tip of the cable conductor 52. Install. The stress cone 50 is made of a pre-molded insulator having rubber-like elasticity such as ethylene propylene rubber (EP rubber). A tapered shape attached to the inner wall surface of the cable receiving port 14 is attached to the tip of the stress cone 50. A cone is provided.

  Next, the cable terminal portion 28 is attached to the cable receiving port 14, and the pressing device 53 previously disposed on the cable terminal portion side is compressed toward the cable receiving port 14 side. As a result, the conductor terminal 54 is plug-in connected to the conductor insertion hole 12 a of the conductor lead bar 12 and the cone-shaped portion of the stress cone 50 is pressed against the inner wall surface of the cable receiving port 14. Therefore, the insulation performance of the interface between the inner wall surface of the cable receiving port 14 and the outer peripheral surface of the cone-shaped portion is ensured. In the figure, reference numeral 56 denotes a seal portion, 57 denotes a lower metal fitting, 58 denotes an intermediate metal fitting, and 59 denotes a ground wire.

In the cable terminal connecting portion configured in this way, the cable receiving port 14 is disposed below the polymer covering 20, so that the polymer cannula 26 can be made thinner than the conventional polymer cannula. . In addition, since the connection between the polymer sleeve 26 and the cable terminal portion 28 is performed at a lower level than the polymer covering 20, the length of the stepped portion of the cable terminal portion 28 can be shortened.
JP 2003-304632 A

By the way, the above technique has the following problems to be solved.
Since the outer diameter of the flange portion 18 of the polymer cover 20 is small, the mounting bolt 42 attached to the support fitting 24 is positioned outward in the circumferential direction of the flange portion 18. Accordingly, since the head of the mounting bolt 42 becomes a protrusion when viewed from the outer surface of the support bracket 24, it flashes at the tip (head) of the mounting bolt when broken.

In order to prevent this flashing, the countermeasure shown in FIG. 4 is considered. That is, as shown in FIG. 4, a shield cap 61 is disposed on the outer surface of the flange portion 22 of the support fitting 24 so as to cover the head of the mounting bolt 42 protruding from the outer surface of the flange portion 22. Is.
However, the configuration in which the head of the mounting bolt is covered with the shield cap 61 has a drawback that the number of parts increases, leading to an increase in assembly man-hours and cost increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cable terminal connection portion having a small number of parts, a simple structure, and improved flashing performance.

In each embodiment of the present invention, the above-described problems are solved by the following configurations.
<Configuration 1>
A hard insulating tube having a conductor lead bar at the center and a cable receiving port at the lower end, and a polymer coating provided on the outer periphery of the insulating tube, with a number of flanges spaced apart in the longitudinal direction on the outer periphery A polymer sleeve including a body and a support fitting having a flange portion protruding outward from a peripheral surface of the insulating cylinder, and a cable terminal portion attached to a cable receiving port of the insulating cylinder, the polymer The covering is positioned higher than the support bracket, the cable receiving port is positioned lower than the support bracket, the flange portion of the support bracket has a curved corner at the outer surface, and a lower surface portion A cable terminal connecting portion characterized in that a screw hole that does not penetrate is provided.

When installing the cable end connection part of Configuration 1 on the support base, a plurality of support insulators are interposed between the support base and the flange part of the support bracket, and fixed with mounting bolts using the screw holes of the flange part. To do. The screw hole of the flange portion does not penetrate the flange portion. The mounting bolt is screwed into the screw hole from the lower side of the flange portion and does not protrude from the upper surface of the flange portion. Therefore, since the corner of the outer surface of the flange portion of the support bracket is a curved surface and a screw hole that does not penetrate is provided on the lower surface portion of the flange portion, it is not necessary to cover the flange portion with a shield cap. Less, it is possible to improve the flashing performance with a simple structure.
Furthermore, the cable terminal connection part of the structure 1 has the following effect. That is, since the cable receiving port is positioned below the support metal fitting and below the lower end of the polymer covering, the polymer cannula can be made thinner than the conventional polymer cannula. Further, as a result of thinning of the polymer cannula, the projected cross-sectional area of the polymer cannula becomes small, and a predetermined fouling withstand voltage characteristic can be maintained even with a short polymer cannula. In addition, since the polymer cover is positioned higher than the support metal fitting, and the connection between the conductor lead bar and the cable conductor is performed lower than the polymer cover, the length of the stepped portion of the cable terminal portion is reduced. Can be shortened.

<Configuration 2>
The cable terminal connection part according to Configuration 1, wherein a bottom metal part for fixing a support insulator is attached to a flange part of the support metal part with an attachment bolt screwed into the screw hole. .

A plurality of support insulators are disposed between the support frame and the bottom metal fitting when the cable terminal connection portion is installed on the support frame.
The mounting bolt screwed into the screw hole of the flange of the support metal from below does not penetrate the upper surface of the flange portion. Therefore, a flashing at the tip of the mounting bolt is prevented.

  Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1 is a cross-sectional view showing a cable terminal connection portion of Example 1, and FIG. 2 is an enlarged cross-sectional view of a main part thereof.
The cable terminal connection portion of the first embodiment shown in these drawings is the same as the overall structure shown in FIG. 3 except for the components of the support metal fitting 24 provided in the lower portion of the insulating cylinder 16. Therefore, in FIG. 1 and FIG. 2, the same parts as those in FIG.

  1 and 2, the cable terminal connecting portion of the first embodiment is provided on the outer periphery of a hard insulating tube 16 having a conductor lead bar 12 at the center and a cable receiving port 14 at the lower end, and the insulating tube 16. A polymer covering body 20 having a large number of flanges 18 spaced apart in the longitudinal direction on the outer periphery, and a support metal fitting 24 having a flange portion 22 protruding outward from the peripheral surface of the insulating cylinder 16. A cannula 26 and a cable terminal portion 28 attached to the cable receiving port 14 of the insulating cylinder 16 are provided.

  The support fitting 24 is connected to a cylindrical portion 23 concentrically embedded in the lower portion of the insulating cylinder 16 with the conductor extraction rod 1 and a lower end portion of the cylindrical portion 23, and is provided outside the peripheral surface of the insulating cylinder 16. And a flange portion 22 protruding in the direction.

The polymer covering 20 is positioned higher than the support bracket 24, and the cable receiving port 14 is positioned lower than the support bracket 24.
As shown in FIG. 2B, the flange portion 22 of the support fitting 24 has a corner portion 30 on the outer surface as a curved surface, and a lower surface portion 32 provided with screw holes 34 and 35 that do not penetrate. Of the screw holes 34, 35, the screw hole 34 is used when attaching the bottom metal fitting 40, and the screw hole 35 is used when fixing the intermediate metal fitting 58. The screw hole that does not penetrate is a blind hole that does not penetrate the upper surface of the flange portion 22 and has a thread groove.

When installing the cable terminal connection portion on the support frame 44, the bottom metal fitting 40 is attached to the flange portion 22 of the support metal fitting 24. The bottom metal fitting 40 is fixed by screwing a mounting bolt 42 into the screw hole 34 of the flange portion 22.
Between the support frame 44 and the bottom metal fitting 40, about 4 to 6 support insulators 38 are disposed around the polymer sleeve 26, and the cable terminal connection portion is supported by the support frame.

  In the first embodiment, the corner portion 30 on the outer surface of the flange portion 22 of the support fitting 24 is formed into a curved surface, and screw holes 34 and 35 that do not penetrate are provided on the lower surface portion of the flange portion 22. Since it is not necessary to cover with a shield cap or the like, the number of parts is small and the flashing performance can be improved.

The present applicant conducted a flash test on the cable termination connection portion of the present invention and examined the result, and will be described below.
(1) AC flash (commercial frequency flash) test results At the tip of the buttocks of the silicone rubber polymer coating with the highest electric field, an air discharge occurs and then flashes. The flash marks remain on the upper metal fittings, but the polymer sleeve has only a partial discoloration at the apex of the buttocks and almost no carbonization. In addition, there is no decrease in the flash value in the re-powering after the flash.
(2) Imp flashing (lightning impulse flashing) test results Streamer marks are seen on the surface of the polymer covering and the buttock surface near the upper metal fitting, but there is no burning. In addition, there is no decrease in the flash value in the re-powering after the flash.

From these facts, it was confirmed that the flashing of the cable terminal connection portion occurred in the air on the surface of the buttock, so that there was little damage to the silicone rubber portion of the polymer coating by the surface flashing.
In the flash test, the mounting bolt is mounted from the bottom surface of the bottom bracket, and the mounting bolt does not protrude from the top surface of the flange portion of the support bracket. did it.

FIG. 3 is a longitudinal sectional view illustrating a cable terminal connection portion according to the first embodiment. It is a longitudinal cross-sectional view which expands and shows the principal part of FIG. It is a longitudinal cross-sectional view which shows the conventional cable termination | terminus connection part. It is a longitudinal cross-sectional view which shows the principal part of the other conventional cable termination | terminus connection part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Conductor extraction rod 14 Cable receiving port 16 Insulation cylinder 18 Eave part 20 Polymer covering body 22 Flange part 23 Cylindrical part 24 Support metal fitting 26 Polymer sleeve 28 Cable terminal part 30 Corner | angular part 32 Lower surface part 34 Screw hole 35 Screw hole 38 Support Insulator 40 Bottom bracket 42 Mounting bolt 44 Support base 46 Protective bracket

Claims (2)

A hard insulating tube having a conductor lead bar at the center and a cable receiving port at the lower end, and a polymer coating provided on the outer periphery of the insulating tube, with a number of flanges spaced apart in the longitudinal direction on the outer periphery A polymer sleeve including a body and a support fitting having a flange portion protruding outward from a peripheral surface of the insulating cylinder;
A cable terminal portion attached to the cable receiving port of the insulating cylinder,
The polymer covering is positioned higher than the support fitting,
The cable receiving port is positioned lower than the support fitting;
The cable terminal connection portion according to claim 1, wherein the flange portion of the support metal fitting has a curved outer corner portion and a screw hole that does not pass through the lower surface portion. In the cable termination connection part according to claim 1,
A cable terminal connection part, wherein a bottom part metal part for fixing a support insulator is attached to a flange part of the support part with an attachment bolt screwed into the screw hole.

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