JP2000037027A - Terminal main part for power cable terminal insulating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the electrical insulation creeping distance of a terminal main part from being declined by contaminant. SOLUTION: A terminal main part 20 for power cable terminal insulating is composed of a shrinkable tube made of synthetic rubber. In addition to an ordinary shade 22, a downward cup-shape deep shade 23 is provided beneath the shade 22 and, further, a wind penetration preventive shade 24 is provided immediately below the shade 23. The downward cup-shape deep shade 23 contributes significantly to increase an electrical insulation creeping distance and, further, the wind penetration preventive shade 24 immediately below the shade 23 prevents contaminants blown up by a wind from penetrating into the reverse-U shaped inside of the downward cup-shaped deep shade 23 to prevent the electrical insulation creeping distance from being declined by the deposition of contaminants on the inner wall 23a of the shade 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal body used for insulating a terminal part of a power cable, and more particularly to a terminal part of a salt-resistant type power cable having a bulk for increasing an electrical insulation creepage distance. Related to the terminal unit main body.

[0002]

2. Description of the Related Art There are various methods for terminal treatment for insulation and mechanical protection of a terminal portion of a power cable, and a terminal body made of porcelain is widely used. This porcelain terminal part body is provided with a bulk to prevent the tracking phenomenon that the electrical insulation is broken on the surface of the insulator, and the electrical insulation creepage distance is increased, but it is used in coastal areas etc. In the case of a salt-resistant terminal body as shown in FIG.
As shown in the terminal body 1 made of porcelain shown in FIG. 1, a normally-shallow depth 1 a and a deep depth 1 b are provided to further increase the electrically insulating creepage distance. The electrically insulating creepage distance is, in the case shown, the total length from the upper part to the lower part along the contour of the terminal part main body 1. In FIG. 4, the press-contact portion 4a of the terminal 4 is connected to the exposed conductor 3 of the power cable 2.
Is connected for compression. 5 is a cable insulator, 6 is a cable outer semiconductive layer, 7 is a shielded copper tape, 8 is a ground wire, 9
Is a stress cone, 10 is a bracket, and 11 is an insulating tape winding.

[0003]

In the above-mentioned terminal portion of the power cable, the depth 1b of the terminal portion main body 1 is effective for increasing the electrical insulation creepage distance. Because of the blowing of the wind,
Inverted interior 1 of bulk 1b with fouling substances such as salt in the air
c and easily adheres to the inner wall surface of the inverted concave interior 1c,
And, since the reverse concave interior 1c of the deep bulk 1b cannot be expected to be washed by rain, there is a problem that a fouling substance adheres and accumulates on the inner wall surface, and the electrical insulation creepage distance decreases.
In addition, since it is made of porcelain, it is heavy and is easily damaged when dropped, so that it is not easy to handle and the workability of cable terminal processing is low. In addition, the terminal body 1 made of porcelain is not easy to mold,
Cost is high. In addition, there is also a terminal body with a shrink tube structure made of synthetic rubber instead of porcelain and also provided with a deep bulk, but the inner wall surface inside the inverted concave shape of the bulk due to wind blowing etc. The same applies to the problem that the electric insulation creepage distance is reduced due to the adhesion and deposition of the metal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and there is little decrease in the creepage distance of electrical insulation due to fouling substances, and it is easy to handle and improves workability in cable terminal processing. It is another object of the present invention to provide a terminal body for power cable terminal section insulation that can be easily formed and is inexpensive.

[0005]

SUMMARY OF THE INVENTION To solve the above-mentioned problems, a terminal body for insulating a power cable terminal part according to the present invention has a shrinkable tube structure made of synthetic rubber and has a downwardly cup-shaped deep portion formed on the outer periphery of the tube body. A bulk and a wind-blocking bulk located directly below the deep bulk.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to the terminal body 20 for insulating the power cable terminal of one embodiment shown in FIG. 1A is a longitudinal sectional front view of a terminal body 20 for insulating a power cable terminal section according to an embodiment of the present invention, FIG. 1B is a bottom view of FIG. 1A, and FIG. FIG. 3 is a partial longitudinal front view of the cable terminal portion in a state in which the cable terminal processing has been completed following the operation shown in FIG. As shown in these figures, the terminal portion main body 20 has a shrinkable tube structure made of synthetic rubber such as EP rubber, chloroprene rubber, silicon rubber, or the like. , And then a deep cup-shaped deep bulk 23. Immediately below the deep bulk 23, for example, a disk-shaped wind intrusion prevention bulk 24 for maintaining a salt resistance function described later is provided. It is preferable that the outside diameter of the wind intrusion prevention bulk 24 for maintaining the salt resistance function is slightly smaller than the inside diameter of the downward cup-shaped deep bulk 23.

The terminal body 20 is a so-called cold-shrinkable tube. As shown in FIG. 2, the terminal body of the power cable is formed by using an inner core 25 which is a cylindrical plastic having a spiral notch 25a, for example. It is covered. That is, this terminal portion main body 20 is previously covered with the inner core 25 to be in an expanded state, and is covered with the terminal processing portion of the power cable 2 at the time of construction, and then the notch 25a of the inner core 25 is cut off and pulled out by spiral cutting. By further pulling the piece 25b, the inner core 25, for example, from the upper end side of the terminal section main body 20 as shown, or
Then, the terminal body 20 is placed in close contact with the cable terminal section. Next, as shown in FIG. 3, the insulating tape 12 is wound.
2 and 3, reference numeral 5 denotes a cable insulator, 6 denotes a cable outer semiconductive layer, 7 denotes a shielding copper tape, and 8 denotes a ground wire.

[0008] The terminal unit main body 20 has three bulkheads 2.
The presence of 2, 23, 24 increases the electrical insulation creepage distance. In particular, the downward bulk 23 having a downward cup shape greatly contributes to increasing the electrical insulation creepage distance. As described in the description of the conventional example, the downward cup-shaped deep bulk 23 has a deep inverted concave shape. It is easy to penetrate into the inside of the shape and adhere to the inner wall surface 23a.
There is an air intrusion prevention bulkhead 24 just below 3 and the opening of the deep cup-shaped deep bulkhead 23 is narrowed.
The blow-up of the wind into the inverted concave shape of the deep cup-shaped deep bulk 23 is small, and the fouling substance is
Adhesion and deposition on a is small. Therefore, the original electrically insulating creepage distance can be maintained for a long time. In addition, since it is less necessary to consider a decrease in the creepage distance of the electrical insulation, the terminal unit main body 20 can be shortened.

Also, since it is made of synthetic rubber instead of porcelain, it is lightweight and does not easily damage when dropped, so that it is easy to handle. Therefore, the workability of the cable terminal processing is improved. Further, since it is made of synthetic rubber, the downward cup-shaped deep bulk 23 and the wind intrusion prevention bulk 24 immediately below it can be easily formed integrally with the tubular portion (tube body 21) by, for example, injection molding. The manufacturing cost is lower than in the case of porcelain.

In this embodiment, only one downward cup-shaped deep bulk is provided, but a plurality of deep bulks may be provided. In this case, the wind-intrusion preventing bulk 24 for maintaining the salt-resistant function may be provided facing each of the downwardly shaped cup-shaped deep bulks, or only a part thereof may be provided. In addition, the wind intrusion prevention volume 24 provided immediately below the downward cup-shaped deep volume 23 is not limited to the disk-shaped volume (that is, shallow depth) as in the embodiment, but may be a deep volume.

[0011]

According to the present invention, since the terminal body for insulating the power cable terminal section is made of synthetic rubber, unlike the porcelain-made one, it is light and does not crack. Therefore, handling is easy, and workability of cable terminal processing is improved.

Since a wind-intrusion preventing bulkhead is provided immediately below the deep-cup-shaped deep bulk 23, pollutants such as salt in the air can be removed by blowing up the wind so that the downward-cup-shaped deep-bulk 23 has an inverted concave shape. It is possible to prevent intrusion into the inside, and therefore, a deep cup-shaped
Thus, it is possible to effectively prevent the fouling substance from adhering to the inner wall surface 23a of the third member 3 to reduce the electrical insulation creepage distance. In addition, it is possible to shorten the overall length of the terminal unit main body.

[0013] Since the downward cup-shaped deep bulk 23 and the wind intrusion prevention bulk 24 immediately below it can be integrally formed with the tubular portion (tube body 21), manufacture is easy and cost is reduced. be able to.

[Brief description of the drawings]

FIG. 1A is a vertical sectional front view of a terminal body for insulating a power cable terminal section according to an embodiment of the present invention, and FIG. 1B is a bottom view of FIG.

FIG. 2 is a longitudinal sectional front view of a cable terminal unit for explaining a state in the middle of a cable terminal processing operation performed using the terminal unit main body.

FIG. 3 is a partially longitudinal front view of the cable terminal portion in a state where the cable terminal process has been completed by continuing work from FIG. 2;

FIG. 4 is a partial longitudinal front view of a power cable terminal configured using a conventional terminal body.

[Explanation of symbols]

Reference Signs List 2 power cable 3 conductor 4 terminal 4a press-contact part 20 terminal body (terminal body for power cable terminal insulation) 21 tube body 22 cap 23 deep cup-shaped downward cup 23a inner wall surface 24 wind prevention cap

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[Procedure amendment]

[Submission Date] July 27, 1998 (1998.7.2)
7)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

The terminal body 20 is a so-called cold-shrinkable tube. As shown in FIG. 2, the terminal body of the power cable is formed by using an inner core 25 which is a cylindrical plastic having a spiral notch 25a, for example. It is covered. That is, this terminal portion main body 20 is previously covered with the inner core 25 to be in an expanded state, and is covered with the terminal processing portion of the power cable 2 at the time of construction, and then the notch 25a of the inner core 25 is cut off and pulled out by spiral cutting. By further pulling the piece 25b, the inner core 25 is removed from the upper end side of the terminal section main body 20 as shown in the drawing or conversely, sequentially from the lower end side of the terminal section main body 20 to the outside. Cover the part with close contact. Next, as shown in FIG. 3, the insulating tape 12 is wound.
2 and 3, reference numeral 5 denotes a cable insulator, 6 denotes a cable outer semiconductive layer, 7 denotes a shielding copper tape, and 8 denotes a ground wire.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tadahiko Oshio 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Co., Ltd. F-term (reference) 5G375 AA02 CB08 DA32 DA38

Claims (1)

[Claims] 1. A shrinkable tube structure made of synthetic rubber, having a deep cup-shaped downward bulk (23) and a wind-intrusion-preventing bulk just below the deep bulk (23) on the outer periphery of a tube body (21). (24) A terminal body for power cable terminal section insulation, comprising: