JPH0124009B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to termination connections for power cables, particularly rubber-plastic cables.

For example, air termination connections for cross-linked polyethylene insulated vinyl sheathed cables require numerous machined parts,
It is constructed using molded parts, an example of which is shown in FIG. In FIG. 1, the insulator 6,
A terminal connection portion is formed by upper and lower metal fittings 7 and 8, an epoxy housing 4, a rubber molded stress cone 3, a pressing mechanism 5 composed of a pressing metal fitting 51, a spring 52, and a supporting metal fitting 53, an insulating oil 9, and the like. In such a configuration, the material costs are high, especially due to the use of the epoxy housing 4 and the pressing mechanism 5, and the assembly work is also relatively complicated.

In order to solve such drawbacks, it is conceivable to attach only the rubber molded stress cone 3 to the cable without using the epoxy housing 4 and the pressing mechanism 5, insert it into the insulating tube 6, and fill it with insulating oil 9. In that case, the interfacial pressure between the rubber stress cone 3 and the cable 1 is applied only by the elastic force of the rubber stress cone itself, making it difficult to obtain sufficient electrical performance. Furthermore, since the rubber stress cone 3 comes into direct contact with the insulating oil 9, a new drawback arises in that the rubber swells.

In addition, as a means to increase the interfacial pressure between the cable 1 and the rubber stress cone 3, the rubber stress cone 3
A method of winding a rubber/plastic tape on an inclined surface is already known, but in this method, it is difficult to wind the rubber/plastic tape properly on an inclined surface, and the tensile stress of the tape itself is often increased. There is a problem in that the winding part loses its shape due to this, and therefore effective tightening cannot actually be achieved.

It is an object of the present invention to overcome the disadvantages associated with the prior art by providing an economical and performance-stable termination connection for rubber-plastic insulated cables.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 2 is a partial cross-sectional view of one embodiment of the present invention. In FIG. 2, a rubber stress cone 3 is arranged on a cable 1 whose end has been conventionally treated so that the conductive portion 13 of the rubber stress cone 3 is electrically connected to the outer conductive layer 12 of the cable 1, and further An insulating rubber spacer 3' is placed opposite the rubber stress cone 3. Then, the outer ends of the rubber stress cone 3 and the rubber spacer 3' were fixed with polyolefin heat-shrinkable tubes 11, respectively (each heat-shrinkable tube 11 was placed on the circumference of the outer end of the rubber stress cone 3 and the rubber spacer 3'. (Insert it through and fix it by heat shrinking it.)
Later, rubber stress cone 3 and rubber spacer 3'
For example, a self-adhesive insulating tape 1 is placed between the
0 is wound and provided. Furthermore, the whole is covered with a polyolefin heat-shrinkable tube 11' to form internal insulation, and then it is inserted into the insulator tube 6 sealed by the upper and lower metal fittings 7 and 8, and insulating oil or insulating compound 9 is injected to connect it. constitute the department.

Here, the heat shrink tube 11 serves to temporarily stop the rubber stress cone 3 and the rubber spacer 3' from being pushed to both sides when forming the winding portion of the insulating tape 10, and on the other hand, After forming the wound portion of the insulating tape 10, the shrink tube 11' is attached to the rubber stress cone 3 and the rubber spacer 3'.
It works to permanently stop the body from being pushed to both sides. That is, although the heat-shrinkable tube 11 alone is not necessarily sufficient, as a result of configuring the heat-shrinkable tube 11' to envelop both the rubber stress cone 3 and the rubber spacer 3', both 3 and 3' are It becomes permanently impossible to be pushed to either side. Furthermore, since the rubber stress cone 3 and the rubber spacer 3' are entirely wrapped in the heat shrink tube 11', both of them are protected from the insulating oil or insulating compound 9 by the heat shrink tube 11'. Therefore, stable performance can be guaranteed over a long period of time.

By configuring the connection part in this way,
Machining parts such as the epoxy housing 4 and the pressing mechanism 5, which were conventionally necessary, are no longer necessary, making it extremely economical. Incidentally, a rubber spacer 3', a tape winding part 10, and heat shrinkable tubes 11, 11' are required in place of the epoxy housing 4 and the pressing mechanism 5, but these are much cheaper than the previous two. Therefore, economic efficiency is greatly improved. Furthermore, as mentioned above, the problem of swelling of the stress cone and insulating tape due to insulating oil etc. does not occur due to the use of the polyolefin heat shrink tube 11'. The interfacial pressure between the stress cone 3 and the cable 1 becomes extremely large due to the fixing and tightening force of both, and stable interfacial electrical characteristics can be obtained. Furthermore, since the inclined surfaces (far end portions) of the stress cone 3 and spacer 3' are held down by heat shrink tubes 11, 11', there is a risk of deformation as in the case of conventional tape winding. Instead, we can expect stable and permanent tightening.

Although the above example shows an example of an air termination connection, the present invention can also be applied to the internal insulation of a transformer direct connection type termination connection used for connection with a transformer, a switch, etc., or an SF ₆ gas submersion termination connection. Of course, are equally applicable.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing a conventional terminal connection.
FIG. 2 is a partial cross-sectional view of a terminal connection according to the invention. 1: Cable, 3: Rubber stress cone,
3': Rubber spacer, 4: Epoxy housing,
5: Pressing mechanism, 51: Push metal fitting, 52: Spring, 53: Support metal fitting, 6: Insulator tube, 7, 8: Upper and lower metal fittings, 9: Insulating oil or insulating compound, 10:
Insulating tape, 11, 11': insulating heat shrink tube, 12: outer conductive layer of cable, 13: conductive part of rubber stress cone.

Claims (1)

[Claims] 1. A rubber mold stress cone 3 is provided on the cable 1 so that the external conductive layer 12 of the cable 1 and the conductive rubber portion 13 of the rubber mold stress cone 3 are electrically connected, and an insulating rubber is provided opposite to the stress cone 3. spacer 3',
The respective far ends of the stress cone 3 and the rubber spacer 3' are fixed onto the cable 1 with a heat shrink tube 11, and an insulating tape 10 is wrapped between the stress cone 3 and the rubber spacer 3'. The cable is characterized in that internal insulation is constructed by further inserting an insulating heat-shrinkable tube 11' over the entirety of the stress cone 3, the insulating tape winding part 10, and the rubber spacer 3'. Termination connection.