JPS601722B2 - Manufacturing method of insulated wire with optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a crosslinked insulated wire containing optical fibers by electron beam irradiation.

Recently, due to the rapid progress of optical fiber, its practical field is rapidly expanding, and optical fiber lines are already interposed in various power cables together with current conductors, and they are used as lines for communication, signals, control, etc. It plays a role as a line for detecting failures in the electric wire itself. Various wire structures have been proposed in which the optical fiber wire is covered with an insulator such as vinyl chloride, polyethylene, or polypropylene together with the conductor. However, in insulated wires that require a crosslinking process, such as crosslinked polyethylene, which is often used to improve heat resistance, embedding optical fiber wires in the insulation coating of the insulated wires has the following problems. was there. Regarding crosslinking of electric wire insulators, two methods are generally widely used: a chemical crosslinking method and an electron beam irradiation crosslinking method. This chemical crosslinking is carried out through an uncrosslinked polyethylene insulated wire in which a crosslinking agent is placed in steam at a high temperature and pressure of, for example, 200q020k9. However, the optical fiber wire extruded together with the conductor by an extruder and embedded in an uncrosslinked polyethylene insulation coating usually consists of a pongee wire (consisting of a core and a cladding part) of about several tens of microns. and
When bare, it is easily damaged by reels, guide rollers, etc., so it is normal for it to be damaged by subsequent handling.
To prevent scratches, a protective coating such as poppy, base resin, or nylon resin is applied to the surface immediately after spinning. Therefore, such resin-coated optical fiber wires are usually embedded in the coating of the uncrosslinked electric wire, but the melting temperature of the resin coating these optical fiber wires is about 120 to 200 qo, and the above-mentioned When an uncrosslinked electric wire is exposed to high temperature, high pressure steam, an optical fiber wire having a resin coating embedded in an insulation coating of uncrosslinked polyethylene or the like is affected by the heat and pressure. For this reason, the coating of the optical fiber line may be thermally deformed during the crosslinking process or may be affected by steam, causing the optical fiber line to seriously deteriorate its transmission characteristics. Next is a method using electron beam irradiation, but when this method is used, the glass of the optical fiber becomes colored under the influence of electron beam irradiation, making it impossible to maintain a product with satisfactory light transmission characteristics. As mentioned above, it has not been easy to manufacture electric wires made of cross-linked insulators containing optical fiber wires, but in the present invention, in the method of crosslinking by electron beam irradiation, To provide a method for manufacturing a cross-linked polyethylene insulated wire with an optical fiber wire by embedding the optical fiber wire in an uncrosslinked insulating coating such as polyethylene while shielding it with a metal layer and irradiating it with an electron beam. It is.

Examples of the present invention will be described below.

In FIG. 1, an optical fiber line 2 is vertically attached to a plurality of twisted conductors 1, and a metal tape 3, for example, a lead tape, is longitudinally attached to wrap the plurality of conductors 1 and the optical fiber line 2, and an insulating The material polyethylene is coated with an extruder to form an uncrosslinked wire, which is then crosslinked by electron beam irradiation to form a crosslinked polyethylene insulation coating 4.
This is an example of forming an insulated wire.

In addition to lead tape, copper tape and aluminum tape may be used as the metal tape. Also, the tape mentioned above is made of PET.
, PE, etc. can also be used. The metal tape may be attached vertically as described above, but may also be wrapped. In the embodiments described above, both the conductor and the optical fiber line are wrapped with a metal layer for shielding electron beams. Next, an example will be shown in which only the optical fiber line is shielded with a metal layer.

FIG. 2 shows an insulating coating 4 having a protrusion 5 on a part of its circular cross section.
This is an example of a crosslinked polyethylene insulated wire formed by electron beam irradiation.

This shape is used to prevent snow from accreting and to improve workability, but the optical fiber line 2 is wrapped in a metal tape 3 near the protrusion and embedded in the polyethylene insulation coating 4. It is rare. Further, FIG. 3 shows an example in which an optical fiber wire 2 wrapped independently in a metal tape 3 is located in a cross-linked polyethylene insulation coating 4 having a circular cross section, and FIG. The book is shown in the form of a pipe of metal tape 3 with an optical fiber line 2 inside, twisted together with other conductors and having a cross-linked polyethylene insulation coating 4 thereon.

The manufacturing method for those in which only the optical fiber line 2 is shielded with a metal layer is understood from what has already been described, but the conductor and the optical fiber line are both wrapped in a metal layer, or only the optical fiber line is shielded with a metal layer. The electric wire is then extruded in an uncrosslinked state while being embedded in an insulating material using an extruder, and then subjected to electron beam crosslinking. After crosslinking, an electric wire with an insulating coating is completed. Note that as the shielding metal layer, a metal may be deposited on the optical fiber coating layer. Furthermore, although the present invention has been described with reference to a single optical fiber line, the present invention may be applied to a plurality of optical fiber lines, and can be applied even when the optical fiber line occupies multiple positions in the insulation coating, and can be further implemented. Although the example uses polyethylene as the insulation coating, manufacturing of insulated wires using insulation materials that are crosslinked by electron beam irradiation, polyolefins such as vinyl, EA, and EVA, EP rubber, and chlorinated PE as the coating. This applies to

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are diagrams for explaining the implementation of the present invention. 1: Conductor, 2: Optical fiber line, 3: Metal tape, 4:
Insulating coating, 5: protrusion. Car diagram 2 diagram soup 3 diagram 4 diagram

Claims (1)

[Claims] 1. A method comprising: covering at least an optical fiber wire with a metal layer and embedding it together with a conductor in an extruded coating material to form an uncrosslinked electric wire, and then irradiating the uncrosslinked electric wire with an electron beam. A method for manufacturing an insulated electric wire containing optical fiber wire. 2. The optical fiber wire-containing insulation according to claim 1, wherein the optical fiber wire and the conductor are covered with a metal layer and then embedded in a coating material that is extruded to form an uncrosslinked electric wire. Method of manufacturing electric wire.