JPS6029137Y2 - oil-filled cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil-filled (OF) cable in which oil leakage can be easily detected.

Generally, in oil-filled cables, the outer circumferential surface of the metal sheath is coated with an anti-corrosion layer via anti-corrosion paint, and in conventional oil-filled cables, cracks and pinholes occur in the metal sheath, causing the internal insulating oil to leak. Even if it leaks to the outside of the metal sheath,
The leaked oil was prevented from moving in the axial direction of the oil-filled cable by the anticorrosion paint and the anticorrosion layer, and only accumulated between the metal sheath and the anticorrosion layer.

Retention of oil between the metal sheath and the anti-corrosion layer is undesirable because the anti-corrosion paint dissolves into the oil and causes deterioration of insulation performance.

There is also the problem that oil will leak out if the anti-corrosion layer is torn.

Detecting these oil build-ups and spills is very difficult.

In other words, oil-filled cables are laid over many lengths,
Oil is supplied from an oil tank at the end of the pipe, but since most of the parts other than the connections are buried underground, it is extremely difficult to detect where oil is leaking.

The purpose of this invention is to easily detect the occurrence of oil leakage from the metal sheath in an oil-filled cable that has an anti-corrosion layer around the outer periphery of the metal sheath, and to make it possible to easily detect the occurrence of oil leakage from the metal sheath and to prevent the accumulation of oil between the metal sheath and the anti-corrosion layer. The objective is to provide an oil-filled cable that can prevent this.

In order to achieve this objective, the oil-filled cable of the present invention is provided with an oil leak passage extending along the axis of the oil-filled cable between the outer peripheral surface of the metal sheath and the anticorrosion layer.

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of the oil-filled cable 1. FIG.

Each layer is arranged concentrically, and in order from the center outward in the radial direction is an oil passage 2, a conductor 3, an insulating layer 4, and an insulating shielding layer 5 made of a copper wire woven cloth tape wrapped around the outer periphery of this insulating layer 4. , an aluminum sheath 6, and an anti-corrosion layer 7 coated with the anti-corrosion paint on the outer peripheral surface of the aluminum sheath 6 coated with the anti-corrosion paint.

At least one location in the circumferential direction of the inner circumferential surface of the anticorrosion layer 7, in the embodiment two locations symmetrical to the center, is provided with an oil leakage passage 8 that extends over the entire length in the axial direction of the oil-filled cable. .

The oil leak passage 8 is provided by partially recessing the inner circumferential surface of the anticorrosive layer 7, or by inserting a porous-walled tube between the aluminum sheath 6 and the anticorrosive layer 7.

The oil leak passage 8 may extend linearly or spirally along the axis of the oil-filled cable.

Oil leaking to the outside of the aluminum sheath 6 through cracks or pinholes formed in the aluminum sheath 6 can move to some extent in the circumferential direction and can reach the oil leak passage 8.

The leaked oil that has reached the oil leakage passage 8 moves in the axial direction of the oil-filled cable 1 through the oil leakage passage, so the oil leakage is removed by stripping off the corrosion protection layer at the end of the corrosion protection layer near the connection in the manhole or at an appropriate location. By checking the presence or absence of oil in the passage 8,
The occurrence of oil leakage can be detected.

Figure 2 shows how oil leaks out in a manhole.

11 is a manhole, and 12 is an underground pipe.

The anti-corrosion layer 7 of the oil-filled cable 1 is partially peeled off and the oil leakage passage 8 is guided to the outside of the oil-filled cable 1.
Connect the end to a gauge or transparent tube 13.

In this way, the occurrence of oil leakage can be detected by checking whether oil has accumulated in the transparent tube 13.

Although the above embodiment shows an oil-filled cable in which one conductor is inserted inside a metal sheath, it is of course applicable to an oil-filled cable in which three conductors are inserted inside a metal sheath.

As described above, according to the present invention, oil leaking from the metal sheath is guided in the axial direction of the oil-filled cable through the oil leakage passage 8 extending between the outer circumferential surface of the metal sheath and the anticorrosive layer. The occurrence of oil leakage can be easily inspected at a suitable location far away from the location.

Furthermore, since oil leakage does not accumulate between the metal sheath and the anti-corrosion layer, it is possible to prevent the anti-corrosive paint from dissolving into the oil.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, and FIG. 2 is a view showing the end of an oil leak passage 8 in a manhole. 1... Oil-filled cable, 6... Aluminum sheath, 7... Anti-corrosion layer, 8... Oil leakage passage.

Claims (1)

[Scope of utility model registration request] In an oil-filled cable in which a conductor covered with an insulating layer is housed in a metal sheath, and an anti-corrosion layer is coated on the outer circumferential surface of the metal sheath, there is an oil-filled cable between the outer circumferential surface of the metal sheath and the anti-corrosion layer. An oil-filled cable characterized by being provided with an oil leakage passage extending along the axis.