JP3259037B2 - Cable connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable connecting portion in which a support structure of a cable drawing portion at a portion connecting a device and a cable via a bushing is ensured.

[0002]

2. Description of the Related Art When connecting a high-voltage cable such as a gas-insulated switch to a high-voltage cable, the following cable connection section is employed. FIG. 2 shows a vertical sectional view of a conventional cable connection portion. As shown in the drawing, a bushing 1 molded by molding an epoxy resin or the like is fixed to a wall surface of a device (not shown) arranged on the left side of the drawing. An internal electrode 2 is provided at the center of the bushing 1 and is electrically connected to the internal conductor of the device. Connection terminals A and B are provided above and below the bushing 1 for connecting cables, respectively. When the device is actually used, a cable for making an electrical connection with another device is connected to one of the terminals, for example, the connection terminal B.

The other connection terminal A is connected with a cable for an electrical test of a device or a cable connected to the connection terminal B. In the figure, a cable 3 connected to a connection terminal A includes a sheath 4, a shielding layer 5, and a semiconductive layer 6.
Then, the insulator 7 is peeled off in order, and the conductor 8 is exposed.
A connection terminal configured by combining a plug 10, a wedge 11, and a wedge tightening fitting 12 is attached to the conductor 8, and is electrically connected to the internal electrode 2.

[0004] A stress cone 13 is fitted around the outer periphery of the insulator 7 of the cable 3. The stress cone 13 is formed by integrally molding an insulating portion 14 made of insulating rubber or the like and a semiconductive portion 15 made of semiconductive rubber or the like. A stopper 9 is inserted between the stress cone 13 and the internal electrode 2 in order to keep the distance between the stress cone 13 and the internal electrode 2 constant.

[0005] The stress cone 13 is provided with a press fitting 16.
The spring unit 18 presses the inner wall surface of the bushing 1 with a certain force or more. Thereby, the stress cone 13 and the bushing 1
A surface pressure commensurate with the insulation characteristics required at the interface with the substrate is provided. The spring unit 18 is provided in the protective case 1.
9 is sandwiched between the washer 17 supported by the step portion and the pusher 16.

The protection case 19 is formed of a metal pipe for surrounding and protecting the terminal portion of the cable 3 exposed from the bushing 1. One end of the protective case 19 is fixed to the bushing 1 by a bolt 21. Further, the lower end thereof is hermetically sealed with the outer peripheral surface of the cable 3 by the tape winding section 22. A lead wire 23 is wound around the shielding layer 5 of the cable 3 and the washer 1
7 and electrically connected to the protective case 19. Thus, the protective case 19 is grounded, and the shielding layer 5 of the cable 3 is grounded. In the state shown in the figure, for example, the test cable 3 is attached to the connection terminal A of the bushing 1 and the other connection terminal B is attached with the blind plug 20 for electrical protection. In such a state, for example, a high voltage is applied to the device through the cable 3 and various electric tests are performed.

[0007]

By the way, the cable connecting portion having the above configuration has the following problems to be solved conventionally. FIG. 3 is a side view showing a state where a cable is actually attached to the device. In the figure, device 25
The bushing 1 as described in FIG.
Has been fixed. A cable 3 is connected to the bushing 1 and is drawn rightward in the drawing. Here, when the cable 3 is connected to a high-voltage power supply or the like, it may be necessary to lay the cable 3 appropriately while avoiding an obstacle 26 or the like as shown in the figure.

In such a case, first, the cable 3 must be laid while maintaining a radius larger than a preset minimum allowable bending radius. Further, in the state as shown in the figure, the own weight of the cable 3 is directly applied to a connection portion of the cable 3 to the bushing 1. At this time, a biasing load is applied to the protection case 19 shown in FIG. 2 and the stress cone 13 housed therein. Thereby, stress corn 1
In some cases, the surface pressure of the bushing 3 becomes non-uniform, and a part of the surface pressure is reduced, resulting in insufficient insulating properties.

Conventionally, in order to solve such a problem,
As shown in FIG. 3, a portion of the cable 3 close to the bushing 1 is supported by a cable presser 27, or an appropriate portion is hung by a cable hanger 28. As a result, the length of the straight portion 3A of the cable 3 is ensured, for example, about 1 meter, thereby preventing the above-mentioned bias load and the like. Further, the radius of curvature in the bent portion 3B is set to be larger than the limit.

However, in such a method, if the straight portion 3A of the cable 3 is not sufficiently long, the partial load cannot be effectively prevented, and if the obstacle 26 is very close to the equipment 25, In this case, there is a problem that it is not possible to maintain a curvature larger than the allowable bending radius at the bent portion 3B. The present invention has been made by paying attention to the above points, and in a case where a cable is pulled out from a bushing and bent and laid, a cable connection that does not apply partial load to a stress cone housed inside the bushing. The purpose is to provide a part.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for electrically connecting a device.
Connected internal electrodes are buried and attached to equipment.
Singing, fixed to the end of the bushing, to the bushing
Attached horizontally to make electrical connection with internal electrodes
Protective case covering cable terminal and attached to cable terminal
Is pressed against the tapered inner wall surface of the bushing end.
Protection at the cable connection with tress cone
After fixing to the case, remove the cable near the protective case.
Cleats that can be detached and placed inside the protective case
And support by inserting the cable section near the stress cone
And a bending prevention pipe.

[0012]

In the cable connecting portion, a cleat is provided so as to grasp the cable portion drawn from the protective case fixed to the bushing. Also, inside the protective case
Is supported by a bending prevention pipe. Therefore, even if the cable is bent, the bending stress is cleared.
From that Tsutawa the stress cone can be prevented in two-stage structure by over preparative and bending prevention pipe. Therefore, it is possible to prevent a situation in which the surface pressure of the stress cone partially decreases.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of a cable connecting portion of the present invention. The configuration of the bushing 1 and the internal electrodes 2 and the like of the cable connection portion in the drawing is the same as the conventional cable connection portion already described with reference to FIG. In the cable 3, the sheath 4, the shielding layer 5, the semiconductive layer 6, and the insulator 7 are stripped to expose the conductor 8.

The conductor 8 is connected to a concentric cylindrical plug having a double structure composed of an inner plug 31 and an outer plug 32, which is used to make an electrical connection between the internal electrode 2 and the conductor 8. Have been. On the other hand, a stress cone 13 composed of an insulating part 14 and a semiconductive part 15 is fitted around the outer periphery of the insulator 7. Further, the stress cone 13 is pushed in a direction toward the inner wall surface of the bushing 1 by the press fitting 16 and the spring unit 18 so as to obtain a constant surface pressure. These configurations are the same as the conventional one.

Here, in the cable connection portion of the present invention, a protection case 35 having a relatively strong structure is used to protect the connection portion of the cable 3 pulled out from the end of the bushing 1. One end 35A of the protective case 35 is fixed to the bushing 1 using the bolt 21. Further, a split tubular cleat 40 as shown in the figure is fixed to the other end 35B. The cleat 40 is fixed to the other end 35B of the protection case 35 by welding or screwing, for example. In this embodiment, the cleat 40 is composed of a receiving member 41, a holding member 42 and a bolt 43, the receiving member 41 is fixed to the other end 35B of the protective case 35, the holding member 42 is detachable, and the bolt 43 Cable 3 by tightening
And fix it. A cushion layer 38 made of a semiconductive rubber tape, a shrinkable tube, or the like is formed between the cleat 40 and the cable 3. This allows the semiconductive layer 6 of the cable 3 to be
This is because the semiconductive layer 6 is not damaged by being gripped with zero.

FIG. 4 shows a side view of a cable laid state pulled out of a device when the cable connecting portion of the present invention is used. As shown in the figure, when the cable connecting portion of the present invention is used, the cable 3 is particularly connected to the bushing 1.
There is no need to provide a long straight section when pulling out from the cable. That is, as shown in this figure, since the portion of the cable 3 pulled out from the bushing 1 is fixed and supported sufficiently firmly using the cleat 40, the stress caused by the bending of the cable 3 is absorbed by the cleat 40, and the stress shown in FIG. Cone 1
It does not reach three. Therefore, the unbalanced load of the stress cone 13 is also prevented. Note that a schematic perspective view of the receiving metal member 41 and the holding metal member 42 constituting the cleat 40 is shown in a circle C in FIG.

In the connecting portion of the present invention, more effective cable support can be performed by the following configuration. That is, as shown in FIG. 1, a washer 37 disposed at a step inside the protective case 35 supports the spring unit 18 and also has a cable 3 at the center thereof.
Is provided with a tubular bend prevention pipe 37A extending in the longitudinal direction of the pipe. The bend preventing pipe 37A surrounds just above the cable 3 between the cleat 40 and the stress cone 13 inside the protective case 35, and holds the cable 3 at this portion even when the cable 3 is bent, The bending stress is stress cone 1
I try not to pass on to 3. Such cleats 4
By using the 0 and the bend prevention pipe 37A together, a further fixed support effect can be obtained.

The present invention is not limited to the above embodiment. In the above embodiment, the shape of the cleats, the number of cleats, the method of supporting and fixing the cleats and the cable, and the like may be freely changed. Further, the cleat may be formed integrally with the protective case, or two or more cleats may be combined to fix and support the cable. Also,
In the above embodiment, when the bend preventing pipe is disposed inside the protective case, the structure in which the washer and the bend preventing pipe are integrated is shown. May be independently supported.

[0019]

The cable connecting portion of the present invention described above.
Is a cleat that grips the cable part drawn out of the protective case and fixes and supports this cable part near the protective case.
And the cable near the stress cone in the protective case.
Bending stress when laying cables is reduced due to cleats and bending because a bending prevention pipe is provided to support
The pipe prevents the stress cone from being placed inside the bushing . Therefore, it is not necessary to provide a sufficiently long straight section in the cable drawn from the bushing, and even when an obstacle is relatively positioned near the bushing, the cable can be bent with a curvature larger than the allowable bending radius. Will be possible.

It should be noted that since a cable for an electrical test does not normally flow a large current, it is not necessary to consider the thermal expansion of the cable at the connection. Therefore, even if the cable is strongly fixed to the protective case using the cleat as described above, there is no possibility that an excessive force is applied to the cable.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of a cable connection part of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional cable connecting portion.

FIG. 3 is a side view showing a conventional cable laid state.

FIG. 4 is a side view showing a cable laid state of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bushing 2 Internal electrode 3 Cable 35 Protective case 37 Washer 37A Bend prevention pipe 40 Cleat 41 Receiving bracket 42 Holding bracket 43 Bolt

Claims (1)

(57) [Claims] 1. A internal electrode electrically connected to the device is embedded, and the bushing attached to the instrument, it is fixed to the end of the bushing, along the horizontal direction so as to electrically connected to the internal electrode in the bushing A cable connecting portion including a protective case for covering the cable terminal to be mounted, and a stress cone mounted on the cable terminal and pressed against the tapered inner wall surface of the bushing end; A cable connecting part comprising: a cleat for detachably gripping a cable part near a case; and a bending prevention pipe disposed in the protective case and supporting the cable part near the stress cone through.