JPS58361Y2 - OF cable connection part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an OF cable connection, and more particularly to an OF cable connection with a plastic insulation layer.

In recent years, as power transmission lines have become ultra-high voltage, OF cables having an insulating layer with a low dielectric constant are required.

For this reason, prototype OF cables are being developed in which the insulating layer is made of plastic tape or plastic-containing insulating paper tape instead of the conventionally used kraft insulating paper.

On the other hand, the lead method is almost always adopted for the airtight connection between the junction box and the cable sheath at the OF cable connection section.

For this reason, during lead work, the temperature inside the cable sheath reaches a high temperature of nearly 200 degrees Celsius, but this poses a problem in that the plastic insulation layer under the cable sheath is susceptible to thermal deterioration.

This idea was created in view of the above points.

An object of the present invention is to provide an OF cable connection part that can prevent a plastic insulating layer from deteriorating due to high heat during lead work.

In the present invention, the corrugated metal sheath of an OF cable having a plastic insulating layer is formed into a right cylindrical shape near the plumb joint, and a heat insulating material is interposed on the plastic insulating layer inside this right cylindrical part.

The invention will be explained below with reference to one illustrated embodiment.

In the figure, the OF cable 1 to be connected is the conductor 1 at the end.
, plastic insulation layer 3. Shielding layer 4. Corrugated metal sheath 5
The conductor of the other OF cable (not shown) to be connected is connected to the sleeve 6.

The plastic insulating layer 3 is formed by winding a plastic tape having a low dielectric constant such as cross-linked polyethylene 0 or an insulating paper tape containing the same plastic.

A reinforcing insulating layer 7 is provided at and near the sleeve connection portion.

This reinforcing insulating layer 7 is covered by a junction box 8.

Both ends of the junction box 8 are connected to the peeled corrugated metal sheath 5 with lead fittings 9.

A portion 10 of the corrugated metal sheath 5 near the lead connection is formed into a right cylindrical shape, and a plastic insulating layer 3 is formed within this right cylindrical portion 10.
A heat insulating material 11 is inserted on top.

The right cylindrical part 10 is formed by stretching the corrugated part with a suitable tension tool, but it is sufficient to form a gap of about a certain amount between it and the plus sack insulating layer 3.
The surface may have some unevenness.

The heat insulating material 11 is a molded product of heat-resistant and oil-resistant glass fiber or kraft paper, and is vacuum-dried so as not to have a negative electrical effect on the edge layer 3.

Oil-impregnated.

The range in which the heat insulating material 11 is inserted is preferably at least 50 mm longer than the lead connection part 9.

In the connection part configured as described above, the end of the corrugated metal sheath is stretched and formed into a right cylindrical shape before the lead connection part is provided, and the heat insulating material 11 is inserted into this right cylindrical part. High heat during lead work is blocked, and thermal deterioration of the plastic insulating layer 3 is prevented.

The OF cable connection portion according to the present invention is formed into a right cylindrical shape near the lead connection portion of the corrugated metal sheath of the OF cable having a plastic insulation layer.

By interposing the heat insulating material on the plastic insulating layer inside the right cylindrical portion, it is possible to prevent the plastic insulating layer from deteriorating due to the high heat generated during lead work.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an example of the OF cable connection part according to the present invention. 1...OF cable, 2...Conductor, 3
...Plastic insulating layer, 5 ... Corrugated metal sheath, 8 ... Connection box, 9 ... Leadwork connection part, 10 ...・Right cylindrical part, 11...
・Insulation material.

Claims (1)

[Claims for Utility Model Registration] 1 O having a corrugated metal sheath on a plastic insulating layer
At the OF cable connection part, where a connection box is placed over the conductor connection part of the F cable and both ends of the connection box are connected to the corrugated metal sheath by a lead wire, the vicinity of the lead connection part of the corrugated metal sheath is formed into a right cylindrical shape. , an OF cable connection part characterized in that a heat insulating material is interposed on the plastic insulation layer inside the right cylindrical part. 2. The OF cable connection section according to claim 1, wherein the plastic insulation layer is composed of a wound layer of insulating paper tape containing crosslinked polyethylene. 3. The OF cable connection part according to claim 1 or 2, wherein the heat insulating material is made of heat-resistant and oil-resistant glass fiber or kraft paper.