JPS5854566B2 - Construction method of insulation reinforcement part of plastic insulated power cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for configuring an insulation reinforcement part of a plastic insulated cable cable, and more specifically, the present invention relates to a method for configuring an insulation reinforcement part of a plastic insulated cable cable, and more specifically, the present invention relates to a method for constructing an insulation reinforcement part of a plastic insulated cable cable, which is mainly used for high voltage applications. The present invention relates to a method for constructing an insulation reinforcement section.

One of the cable terminals of this kind currently in practical use,
Referring to FIG. 1 of the accompanying drawings, reference numeral 1 indicates a cross-linked polyethylene insulated vinyl sheath smear cable (hereinafter referred to as CV cable) to be treated.

) and the vinyl sheath (protective covering layer) 2 and the outer shielding layer (
Alternatively, the outer semiconductive layer 3 is sequentially peeled off to expose its own crosslinked polyethylene insulation coating layer 4 over a predetermined section.

Reference numeral 5 designates a lead-out terminal bar attached to the end of the conductor 6 of the C■ cable 1.

Reference numeral 7 denotes an insulating reinforcing layer formed on the periphery of the insulating coating layer 4, which is formed by rolling up insulating paper as shown.

Reference numeral 8 denotes a molded bellmouth-shaped insulator 9 made of epoxy resin that is closely inserted around the circumference of the insulation reinforcing layer 7 and is connected to the outer cocoon-shielding layer 3 side of the insulation reinforcement layer 7 button and the molded bellmouth-shaped insulator 8. A conductive layer is formed on the rising surface of the conductive layer, which is electrically connected to the external shielding layer 3 at one end thereof.

Reference numeral 10 denotes an insulator tube inserted around each of the above members to cover them, and as shown in the figure, an upper metal fitting 11 and a lower metal fitting 12 are respectively formed on the upper and lower sides of the insulator tube, and each of the above members is sealed. There is.

The insulator tube 10 may be made of, for example, hard synthetic resin such as epoxy resin or ceramics.

Reference numeral 13 indicates an insulating oil (for example, silicone oil) filled in the insulator tube 10, and reference numeral 14 indicates a watertight tape wrapping layer provided at the end of the lower metal fitting 12.

Now, according to the terminal section configured as described above, the electric field at the terminal section can be brought into an ideal state by using the insulation reinforcing layer 7 and the bellmouth-shaped insulator 8, and the insulating tube By using the 10 button, silicone oil 13, etc., the creeping strength of the button between the ground side electrode and the conductor 6 can be made sufficiently small, and therefore, it can be expected to be an excellent cable terminal part.

However, this type of cable terminal section is not completely free from problems.

In other words, as the voltage of cables increases, the thickness of the insulating coating layer naturally increases. The degree of thermal expansion and contraction of the layer becomes significantly greater.

However, at this time, in the cable terminal portion of the above structure, the insulation reinforcing layer 7 and furthermore the bellmouth-shaped insulator 8 cannot follow the thermal expansion and contraction of the insulation coating layer 4, and therefore, over time, , gaps are likely to occur between these members 4, 7, and 8.

In this way, if a gap is created between the insulating coating layer, the insulating reinforcing layer, and the bellmouth-shaped insulator, the gap becomes an electrical weak point.
It is expected that this will not only lead to a loss of mechanical stability, but will eventually result in the inability to maintain desired properties.

Therefore, as a result of intensive research, the inventors of the present invention have successively peeled off the protective coating layer button and the external shielding layer (or external semiconductive layer) at the end of the plastic insulating coating layer. A molded insulating spacer made of the same or similar material as the insulating coating layer is placed on the insulating coating layer of the plastic insulating capeple exposed over the section of the insulating coating layer. A molded bellmouth-shaped insulator made of the above-mentioned material is closely inserted therethrough, and a conductive layer is further formed on the raised surface of the outer shielding layer (or outer semiconductive layer) side of the molded insulating spacer and the molded bellmouth-shaped insulator. We have developed an insulation reinforcing section for a plastic insulated capeple, in which one end of the conductive layer is electrically connected to an external shielding layer (or an external semiconductive layer).

More specifically, instead of the insulation reinforcing layer 7 shown in FIG. 1, a molded insulation spacer 70 made of, for example, crosslinked polyethylene is closely inserted around the four insulation coating layers of the cable as shown in FIG. Furthermore, instead of the molded bellmouth-shaped insulator 8 made of epoxy resin, a molded bellmouth-shaped insulator 80 made of cross-linked polyethylene is closely inserted over the circumference of the spacer 70.

Reference numeral 90 denotes a conductive layer formed on the rising surface of the cable outer shielding layer 3 over both the button of the molded insulating spacer 70 and the molded bellmouth-shaped insulator 80, which coats the crosslinkable conductive paint with the spacer 70. and an insulator 80 were applied and baked (by doing so, the conductive paint chemically bonds to the spacer 70 and the insulator 80, making it possible to bond extremely strongly.

). Here, the conductive layer 90 is connected to the spacer 70''J=- and the insulator 8, respectively.
Although the spacer 70 and the insulator 80 are formed in advance on the insulation coating layer 4, they may be formed after the spacer 70 and the insulator 80 are attached on the insulation coating layer 4.

According to the cable insulation reinforcing section configured in this way, instead of the conventional paper-wrapped insulation reinforcing layer 7, a molded insulation spacer 7 made of crosslinked polyethylene, which is the same material as the insulation coating layer 4, is used.
0 is used, and in place of the conventional bellmouth-shaped molded body 8 made of epoxy resin, a bellmouth-shaped molded body 80 made of crosslinked polyethylene is used, so that both the above-mentioned members 70.80 In this case, the cable always exhibits the same thermal expansion and contraction as the insulation coating layer 4 of the cable, and therefore both members 70 and 80 can follow the thermal expansion and contraction of the insulation coating layer 4 at any time. When is the most electrically important part of the terminal part located in the terminal section?
However, it can be maintained in its original ideal state.

SUMMARY OF THE INVENTION An object of the present invention is to provide a useful method for constructing the above-mentioned plastic-insulated cable insulation reinforcement.

That is, the gist of the present invention is to sequentially strip off the protective coating layer and the external shielding layer (or external semiconductive layer) at the ends of the plastic insulating capacitor to be treated, and to apply the plastic insulating coating layer to a predetermined level. a step of exposing the spacer over the section; and a step of heating and expanding a pre-prepared molded insulating spacer made of the same or similar material as the insulating covering layer, and then inserting it onto the insulating covering layer. , or a step of heating and expanding a pre-prepared molded bellmouth-shaped insulator made of the same or similar material as the insulating coating layer, and then inserting it onto the molded insulating spacer. , cooling and shrinking the molded insulating spacer and the molded bellmouth-shaped insulator;
A step of bringing the molded insulating spacer into close contact with the insulating coating layer and a molded bellmouth-shaped insulator with the molded insulating spacer, respectively; Insulation of a plastic insulated capeple, characterized by the step of electrically connecting one end of a conductive layer applied to a rising surface of an external semiconductive layer to an external shielding layer (or an external semiconductive layer) It is in the construction method of the reinforcement part.

The above-mentioned conductive layer can be formed, for example, by applying a cross-linkable conductive paint (conductive paint containing a cross-linking agent) to the rising surface of the molded insulating spacer button and the molded bellmouth-shaped insulator and baking it, or by baking a conductive paint made of conductive plastic. It is formed by molding a compound onto the rising surface, or by wrapping a conductive plastic tape around the rising surface and then heating and molding it.

The heating temperature when heating and expanding the molded insulating spacer and the molded bellmouth-shaped insulator varies slightly depending on the material, but for example, when the material is crosslinked polyolefin, A temperature of about 120°C is appropriate.

The reason for this is that when the temperature is 80°C or lower, the degree of expansion is insufficient, so when it is later cooled and shrunk, the adhesion to the inner member tends to be insufficient.
If the temperature exceeds 20°C, not only will it have a negative thermal effect on the material, but it will also be extremely difficult for workers to handle. be exposed.

Therefore, if the material is heated too much, the worker cannot easily touch it, which ultimately impairs the workability.

) etc. Next, the present invention will be described in detail with reference to FIGS. 1 and 2 of the accompanying drawings, but it should be noted that the present invention is not to be construed as being limited by these examples.
not.

There may be some embodiments other than this embodiment, but as long as they are essentially within the technical scope of the present invention, they are all part of the present invention.

For example, in the embodiment described below, both the molded insulating spacer and the bellmouth-shaped insulator are passed through the insulating coating layer and the spacer, and then both are cooled and shrunk together. A molded insulating spacer may be drawn over the insulation coating layer and allowed to cool and shrink, after which a molded bellmouth insulator may be inserted over the spacer.

Now, to explain how to construct the molded insulating spacer 70 button and the molded bellmouth-shaped insulator 80, first, the molded insulating spacer 7 made of crosslinked polyethylene prepared in advance is explained.
80 to 1 prior to inserting 0 over the 4th circumference of the insulating coating layer.
Expand by heating at a temperature of about 20°C.

After the spacer 70 has been sufficiently heated and expanded, it is inserted over the circumference of the insulating coating layer 4 as shown in FIG.

At this time, since the spacer 70 is in a heated and expanded state,
The task can be done quite easily.

Next, in the same manner, a previously prepared bellmouth-shaped insulator 80 made of cross-linked polyethylene is heated and expanded.

After the insulator 80 has been sufficiently heated and expanded, it is inserted over the spacer 70 as shown in FIG.

After that, the molded insulating spacer 70 and the molded bellmouth-shaped insulator 80 are cooled and contracted, so that the spacer 70 and the insulator 80 are strongly bonded to the insulating coating layer 4 and the spacer 70, respectively. bring them close together.

The members 10 to 14 other than the insulating spacer 70 button and the molded bellmouth-shaped insulator 80 are assembled by the same construction method as the conventional one, so a description thereof will be omitted.

The method of configuring the insulation reinforcement part of the terminal part of the plastic insulated cable cable has been explained above, and the construction method of the insulation reinforcement part of the connection part is also carried out in substantially the same way.
Moreover, it goes without saying that effects similar to those described below can be achieved.

Now, according to the construction method of the insulation reinforcing portion of the cable of this embodiment carried out in this manner, the molded insulation spacer 70 and the molded bellmouth-shaped insulator 80 are first heated and expanded, and then left in that state. The spacer 70 is inserted onto the insulating coating layer 4, and the insulator 80 is inserted onto the spacer 70,
After that, they are assembled by cooling and shrinking them, so even a beginner can easily carry out the work, and each part has a diameter of 4°70.
It is possible to make a very strong adhesion to the top, and to produce the desired insulation reinforcement part.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the insulation reinforcement part of a conventional plastic insulation type cable of this type, and FIG. 2 is an explanatory diagram showing an example of the method of constructing the insulation reinforcement part of the plastic insulation type cable of the present invention. FIG. 1...Cv cable, 2...vinyl sheath (protective coating layer), 3...outer shielding layer (or outer semiconductive layer), 4...crosslinking Polyethylene insulation coating layer, 5... Output terminal bar, 6...
Conductors 1, 7...Paper insulation reinforcement layer, 8...
・Molded bellmouth-shaped insulator made of epoxy resin, 9...
...Conductive layer, 10...Insulator tube, 11...
・Upper metal fitting, 12...Lower metal fitting, 13...
... Silicone oil, 14 ... Watertight tape wrapping layer, 7
0... Molded insulating spacer made of cross-linked polyethylene, 80... Molded bellmouth-shaped insulator made of cross-linked polyethylene, 90... Conductive layer.

Claims (1)

[Claims] 1. The protective coating layer and the external shielding layer (or external semiconductive layer) at the end of the plastic insulating capeple to be treated are sequentially peeled off, and the plastic insulating coating layer itself is removed in a predetermined section. heating and expanding a pre-prepared molded insulating spacer made of the same or similar material as the insulating covering layer, and then inserting it onto the insulating covering layer; heating and expanding a molded bellmouth-shaped insulator made of the same or similar material as the insulating coating layer, also prepared in advance, and then inserting it over the molded insulating spacer; A step of cooling and shrinking the insulating spacer and the molded bellmouth-shaped insulator to bring the molded insulating spacer into close contact with the insulation coating layer and the molded bellmouth-shaped insulator with the molded insulating spacer, One end of the conductive layer applied to the rising surface of the spacer button and the external shielding layer (or external semiconductive layer) side of the molded bellmouth-shaped insulator is electrically connected to the external shielding layer (or external semiconductive layer). A method of constructing an insulation reinforcing part of a plastic insulation type cable, which is characterized by comprising the following steps. 2. A method for constructing an insulation reinforcing portion of a plastic insulated capeple according to claim 1, wherein the material of the insulation coating layer, the molded insulation spacer, and the molded bellmouth-shaped insulator are crosslinked polyethylene. 3. A method for constructing an insulation reinforcing portion of a plastic insulated capeple according to claim 1, wherein the conductive layer is formed by baking a crosslinkable conductive material onto a molded insulating spacer button and a molded bellmouth-shaped insulator. .