JP4372745B2 - Cable connection - Google Patents

Description

  The present invention relates to a cable connecting portion provided with a lead wire for voltage detection, such as a switch such as a GIS (Gas Insulated Switchgear), a transformer, or a motor.

  Conventionally, as a cable connecting portion 12 provided with this type of power detection lead wire, for example, there is a structure shown in FIG. That is, in FIG. 4, the stress cone 20 having the semiconductive rubber layer 18 and the resin push pipe 21 are fitted on the cable insulator 16 at the end of the cable in a connected state. A protective metal fitting 22 is provided around the push pipe 21. A ring 30 is fitted to the end portion of the cable conductor via the compression terminal 28. The cable end is inserted into the bushing 34. A ring 30 is fitted on a cap-shaped connecting conductor 32 provided on the top of the bushing 34.

  One end of the protective metal fitting 22 is joined to the bushing 34 via the flange 36, and is fixed by mounting bolts 38 arranged at several places around it. A coil spring 40 is interposed between the protective fitting 22 and the push pipe 21 so that the push pipe 21 always presses one end surface of the stress cone 20.

  For the anticorrosion treatment or the waterproof treatment, a heat shrinkable tube 42 is placed over the protective metal fitting 22 and the cable insulator 16 and is heat-shrinked so that one end surface of the protective metal fitting 22 is sealed. In the vicinity of the portion of the stress cone 20 where the tip of the push pipe 21 is in contact, a voltage detector 44 having an electrode is embedded. One end of a lead wire 46 for voltage detection connected to a voltage detection indicator (not shown) outside the cable connection portion 12 is connected to the voltage detection unit 44. The lead wire 46 for electric detection is wired along the cable insulator 16 in the push pipe 21 and the heat shrinkable tube 42 and is drawn out to the outside.

By the way, the above technique has the following problems to be solved.
When assembling the above-described conventional cable connection portion, when performing anticorrosion and waterproofing, a heat shrink tube is often used because of its simplicity. The heating and shrinking work requires a fire such as a dryer or a gas torch. For this reason, there exists a possibility that the coating | cover of the lead wire inside a heat contraction tube may be damaged with the heat at the time of a heating.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a cable connecting portion in which the lead wire for detection is not thermally damaged by the heat shrinking operation of the heat shrinkable tube.

In each embodiment of the present invention, the above-described problems are solved by the following configurations.
<Configuration 1>
A stress cone connected and fitted on the cable insulator, a protective metal fitting joined to the bushing via a flange , a voltage detection unit having an electrode embedded in the stress cone, and one end pressed against the stress cone. A lead wire for voltage detection connected to the voltage detection unit embedded in the vicinity where the pipe is in contact, and connected to an external voltage detection display through the cable insulator and the protective metal fitting. A cylindrical protective cover having an opening through which the lead wire for voltage detection is inserted and fitted over one end of the protective fitting and a cable insulator; and one end of the protective cover; An anticorrosion layer made of a heat-shrinkable tube provided across the cable insulator, the opening of the protective cover is at a position away from the anticorrosion layer, and the lead wire for voltage detection is the anticorrosion layer Placed away from Cable connection, characterized in that it is.

  The lead wire for detection is pulled out from the opening of the protective cover, so that the lead wire for detection is separated from the heating part when the cable connection part is assembled. Can be avoided.

<Configuration 2>
The cable connection part according to Configuration 1, wherein the opening of the protective cover is formed in a cylindrical shape protruding outward.

  Since the opening has a cylindrical shape protruding outward, the lead wire for voltage detection can be stably inserted in a sealed state.

<Configuration 3>
3. The cable connection part according to Configuration 1 or 2, wherein a connection terminal having a conductor insertion hole for joining a conductor of the power detection lead wire is fitted into the opening of the protective cover.

  The lead wire for electric detection can be detachably connected at the opening of the protective cover.

<Configuration 4>
In the cable connecting portion according to any one of the first to third aspects, the protective cover is formed of a rubber elastic material having elasticity that is in close contact with the outer peripheral surfaces of the protective metal fitting and the cable insulator. A cable connection part characterized by that.

  Both ends of the protective cover are fitted in close contact with the protective metal fitting and the cable insulator.

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

  FIG. 1 is a cross-sectional view showing a cable connecting portion of the first embodiment, and the same reference numerals are given to the same portions as those in FIG. 4 described above. As shown in the figure, the cable connecting portion 12 includes a stress cone 20 and a protective metal fitting 22 fitted in a state of being connected to the cable insulator 16 at the cable end portion, and a voltage detection device having electrodes embedded in the stress cone 20. A lead wire 46 for power detection, one end of which is connected to the power detection unit 44, and the other end is connected to the external power detection display through the cable insulator 16 and the protective metal fitting 22. A cylindrical protective cover 48 having an opening 50 through which the lead wire 46 is inserted and fitted over one end of the protective fitting 22 and the cable insulator 16, and one end of the protective cover 48 and the cable An anticorrosion layer 54 made of a heat-shrinkable tube is provided across the insulator 16.

  A resin push pipe 21 is provided inside the protective fitting 22. The push pipe 21 and the stress cone 20 are abutted against each other. A ring 30 is fitted to the end portion of the cable conductor via the compression terminal 28, and a cap-like connecting conductor 32 is further fitted thereon. A bushing 34 is fitted on the periphery of the connecting conductor 32 and the stress cone 20. The connecting conductor 32 is integrally attached to the bushing 34.

  One end of the protective metal fitting 22 is joined to the bushing 34 via the flange 36, and is fixed by mounting bolts 38 arranged at several places around it. Between the protective metal fitting 22 and the push pipe 21, there is interposed a coil spring 40 biased so as to separate the two cylinders from each other in the axial direction. The push pipe 21 always presses one end surface of the stress cone 20 in the axial direction by the coil spring 40.

  The outer peripheral surface of the stress cone 20 is a tapered surface that tapers in the left direction in the figure. Also on the inner peripheral surface of the bushing 34 facing the taper surface, a taper surface tapering toward the left in the figure is provided. Accordingly, the stress cone 20 is pressed between the bushing 34 and the cable insulator 16 by being pushed leftward in the drawing by the push pipe 21.

  In the vicinity of the portion of the stress cone 20 where the tip of the push pipe 21 is in contact, a voltage detector 44 having an electrode is embedded. One end of a lead wire 46 for voltage detection connected to a voltage detection display (not shown) disposed outside the cable connection portion 12 is connected to the voltage detection unit 44 by soldering. The power detection lead wire 46 is wired along the cable insulator 16 in the push pipe 21 and is drawn out from the opening 50 of the protective cover 48. Since the voltage detection lead wire 46 is separated from the anticorrosion layer 54 made of a heat-shrinkable tube provided at one end of the protective cover 48, it is not affected by heat.

  The protective cover 48 is formed of a rubber elastic material having elasticity that is in close contact with the outer peripheral surfaces of the protective fitting 22 and the cable insulator 16. Both ends of the protective cover 48 are formed smaller than the outer diameters of the protective fitting 22 and the cable insulator 16 in which the inner diameters are fitted, and are fitted in close contact with each other.

FIG. 2 is a cross-sectional view showing a part of the cable connecting portion of the second embodiment, and the same reference numerals are given to the same portions as FIG.
In the cable connecting portion of this embodiment, the opening 50 of the protective cover 48 is formed in a cylindrical shape protruding outward. If the inner diameter of the opening 50 is formed to be smaller than the outer diameter of the detection lead wire 46, the detection lead wire 46 can be inserted in a sealed state. The configuration other than the opening 50 is the same as the configuration shown in FIG.

FIG. 3 is a cross-sectional view showing a part of the cable connecting portion of the third embodiment, and the same reference numerals are given to the same portions as FIG.
In the cable connecting portion of this embodiment, a connection terminal 52 having a conductor insertion hole for joining a conductor of the lead wire for detection 46 is fitted into the opening 50 of the protective cover 48. The connection terminal 52 has a known configuration including a female terminal 52A and a male terminal 52B that is detachably electrically connected thereto.

  The female terminal 52A is attached to the opening 50 of the protective cover 48, and the voltage detection lead wire 46 is connected to the inner end face. The male terminal 52 </ b> B is connected to one end of a power detection lead wire 46 connected to a power detection display 56 disposed outside the cable connection portion 12, and is covered with an insulating cover 58. The configuration other than the opening 50 is the same as the configuration shown in FIG.

FIG. 3 is a cross-sectional view illustrating a cable connection portion according to the first embodiment. 6 is a cross-sectional view showing a part of a cable connection part of Example 2. FIG. 6 is a cross-sectional view showing a part of a cable connection part of Example 3. FIG. It is sectional drawing which shows the conventional cable connection part.

Explanation of symbols

12 Cable connection portion 16 Cable insulator 18 Semiconductive rubber layer 20 Stress cone 21 Push pipe 22 Protective fitting 28 Compression terminal 30 Ring 32 Connector 34 Bushing 36 Flange 38 Mounting bolt 40 Coil spring 42 Heat contraction tube 44 Electric detection portion 46 Electrical lead wire 48 Protective cover 50 Opening 52 Connection terminal 52A Female terminal 52B Male terminal 54 Anticorrosion layer

Claims (4)

A protective metal fitting joined to the bushing via a stress cone and a flange connected and fitted on the cable insulator;
A voltage detector having an electrode embedded in the stress cone;
One end is connected to the voltage detector embedded in the vicinity of the stress cone pushing the pipe and the other end is connected between the cable insulator and the protective metal fitting and connected to the external voltage detector A lead wire for voltage detection,
A cylindrical protective cover having an opening through which the lead wire for voltage detection is inserted and fitted over one end of the protective metal fitting and a cable insulator;
Provided with an anticorrosion layer made of a heat-shrinkable tube provided across one end of the protective cover and the cable insulator;
The opening of the protective cover is located away from the anticorrosion layer;
The cable connecting portion, wherein the lead wire for voltage detection is wired at a position away from the anticorrosion layer. In the cable connection part of Claim 1,
An opening portion of the protective cover is formed in a cylindrical shape protruding outward, and a cable connection portion. In the cable connection part according to claim 1 or 2,
A cable connection portion, wherein a connection terminal having a conductor insertion hole for joining a conductor of the voltage detection lead wire is fitted into the opening of the protective cover. In the cable connection part in any one of Claim 1 thru | or 3,
The cable connecting portion, wherein the protective cover is formed of a rubber elastic material having elasticity that is in close contact with the outer peripheral surfaces of the protective metal fitting and the cable insulator.

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