JPH0376084B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to power cables, particularly cross-linked polyethylene insulated vinyl sheathed power cables (CV cables).
This invention relates to a method of forming a cable towing end that is useful when introducing a pipeline.

[Prior art] Recently, when renewing cables, old conduits are often used, and cables are becoming larger as capacity increases, resulting in changes in the inner diameter of the conduit and cable finish. Often, the design is designed to make the difference between the two possible.

As shown in FIG. 2, the conventional cable towing end includes a cable core 1 which is penciled so that the insulator part has a tapered part 11, and a metal part which is fitted and crimped onto the conductor 12 exposed by the penciling. Sleeve 2, sheath 3 covering the cable core
and a waterproof coating layer 4 covering the outer peripheral surface of the metal sleeve 2 and the sheath 3.
The cable towing end is formed by first cutting and removing the sheath 3, then penciling the insulator part of the cable core 1 to form a tapered part 11 there, and then inserting the tapered part 11 on the exposed conductor 12. The metal sleeve 2 is fitted and crimped onto the metal sleeve 2 and the sheath 3 is fitted with a heat shrink tube, or a waterproof coating layer 4 is provided by winding a waterproof tape. Ru.

[Problems to be Solved by the Invention] As is clear from FIG. 2, the conventional towing end is constructed with a sheath 3 and a waterproof coating layer 4 overlapping each other, and the cable is This increases the outside diameter of the cable, which requires the inside diameter of the lead-in conduit to be considerably larger than the finished outside diameter of the cable.

To solve this problem, the outer diameter of the cable traction end can be made equal to or less than the finished cable diameter, but conventionally there has been no good way to create such a cable traction end.

[Means for Solving the Problems] The present invention has been made in view of the above points, and its purpose is to provide a cable towing end whose size (outer diameter) is equal to or less than the finished outside diameter of the cable. The purpose is to provide a useful method for manufacturing.

That is, the gist of the present invention is to form an arbitrary number of axial cuts in the sheath of the cable core, further cut the sheath to expose the cable core, and pencil the exposed insulator of the cable core. A process of forming a tapered part at the relevant location and exposing the tip of the conductor, a process of fitting and crimping a metal sleeve to the exposed conductor, returning the cut sheath to the circumference of the tapered part of the insulator, and further removing the cut part. and a step of covering the tapered part with a waterproof coating layer from the restored sheath to the metal sleeve so that its outer diameter is less than or equal to the finished outer diameter of the cable. .

[Embodiment] FIG. 1 is an explanatory diagram of an embodiment of the formal method of the cable traction end of the present invention, in which the cable core 1 is penciled so that its insulator portion has a tapered portion 11. The metal sleeve 2 is placed on the conductor 12 exposed by the pencilling process.
are fitted and crimped, and a PVC sheath 3 is coated on the cable core 1 with its tip extending to the tapered part 11, and a metal sleeve 2
A waterproof coating layer 4 made of a heat-shrinkable tube or waterproof tape is provided on the outer peripheral surface of the PVC sheath 3 on the tapered portion 11 so as to have a dimension equal to or smaller than the finished outer diameter of the cable as shown. Note that 5 is a sealing compound.

Next, to specifically explain the method for forming the cable towing end of the present invention, first, several axial cuts (not shown) are made in the PVC sheath 3 at locations corresponding to the insulator tapered portions described later. The cable core 1 is then cut open from the end of the sheath 3.
to expose. Next, the exposed insulator of the cable core 1 is subjected to penciling processing to form the tapered portion 11 at the relevant location and to expose the tip of the conductor 12. Next, the metal sleeve 2 is fitted and crimped onto the exposed conductor 12. Next, the cut-out sheath 3 is placed back on the tapered portion 11 of the insulator, and the cut portion is welded using a gas burner, a trowel, or the like. Next, after applying a sealing compound 5 between the metal sleeve 2 and the sheath 3, a waterproof coating layer 4 is applied from the metal sleeve 2 to the sheath 3 using a heat shrink tube or various waterproof tapes.
is coated so that the outer diameter of the cable itself is less than or equal to the finished outer diameter of the cable.

In addition, in the above embodiment, the case of a single-core cable was explained, but triplex type and three-core cable are used.
The same applies to the core cable, and does not depart from the gist of the present invention.

Further, in the above embodiment, the conductor 12 is exposed by penciling the insulator of the cable core 1, but the conductor 12 is exposed by removing the ends of the sheath and the insulator before cutting the sheath 3. You may go depending on the situation.

[Effects of the Invention] As explained above, according to the present invention, it is possible to easily form a cable traction end portion whose maximum outer diameter is equal to or less than the finished outer diameter of the cable, and therefore, it can be said that its industrial value is very large.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing an example of a method of forming a cable traction end portion according to the present invention, and FIG. 2 is an explanatory view showing a conventional example. In each figure, the same parts are given the same reference numerals. 1: Cable core, 11: Tapered part, 12: Conductor, 2: Metal sleeve, 3: PVC sheath, 4:
Waterproof coating layer, 5: Sealing compound.

Claims (1)

[Claims] 1 Forming an arbitrary number of axial cuts in the sheath 3 of the cable core 1, further cutting the sheath 3 to expose the cable core 1, and penciling the exposed insulator of the cable core 1,
A tapered portion 11 is formed at the location, and the conductor 1
The process of exposing the tip of the conductor 12 and the exposed conductor 12
A process of fitting and crimping the metal sleeve 2 on the insulator, a process of returning the cut-out sheath 3 to the circumference of the tapered part 11 of the insulator, and further welding the cut part, and a process of placing the restored sheath 3 on the tapered part 11. A method for forming a cable traction end, which comprises the step of covering a metal sleeve 2 with a waterproof coating layer 4 such that the outer diameter of the waterproof coating layer 4 is less than or equal to the finished outer diameter of the cable.