JP2013235687A - Power cable and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power cable which allows for enhancement in the workability of terminal treatment and productivity, and to provide a production method therefor.SOLUTION: A power cable 1 includes a stranded core wire 5 produced by stranding a plurality of insulated core wires 3, holding means 7 for holding the stranded state of the stranded core wire 5, and a sheath 9 applied to the outer periphery of the stranded core wire 5, held by the holding means 7, by extrusion molding. The holding means 7 has a plurality of linear members 11, 13 consisting of at least two linear members wound around the outer periphery of the stranded core wire 5. Melting point of at least one linear member 13 out of the plurality of linear members 11, 13 is set lower than the melting point of the sheath 9.

Description

  The present invention relates to a power cable and a manufacturing method thereof.

  Conventionally, as a power cable, a cable body as a wire core twisted body in which a plurality of insulated wire cores are twisted together, a high-strength fiber string and a holding tape as a holding means for holding the twisted state of the cable body, There has been known one provided with a sheath that is covered by extrusion molding on the outer periphery of a cable body held by a strength fiber cord and a holding tape (for example, see Patent Document 1).

  In this power cable, in the cable body, the gap between the twisted insulated wire cores is filled with inclusions such as jute or polypyrene string, and a plurality of high-strength fiber strings are wound horizontally on the outer periphery of the cable body. A tape such as a rubberized cloth tape or a non-woven fabric is wound around the outer periphery of the high-strength fiber cord, and a sheath such as a vinyl sheath is extrusion coated on the outside of the tape.

JP-A-7-141946

  However, in the power cable as in Patent Document 1, in the terminal processing when connecting to a switchboard or the like, it is necessary to delete the tape as the holding means, which is troublesome and the deleted tape. As a result, the workability of the terminal processing has been reduced.

  In addition, as the holding means, there may be provided an extrusion intervention by extrusion molding of resin or the like on the outer periphery of the wire core twisted body. In this case, when producing the power cable, the extrusion line is passed twice or more. It was necessary and productivity was reduced. In addition, when a tape is used as the holding means, there is a limit to the ability of the taping machine, such as moving a taping head having a large weight, which limits productivity.

  Therefore, an object of the present invention is to provide a power cable that can improve the workability of the terminal processing and also improve the productivity, and a method for manufacturing the power cable.

  The invention according to claim 1 is a wire core twisted body in which a plurality of insulated wire cores are twisted together, holding means for holding the twisted state of the wire core twisted body, and the wire core twisted body held by the holding means. A power cable provided with a sheath coated by extrusion molding on the outer periphery of the wire cable, wherein the holding means includes a plurality of linear members wound around the outer periphery of the wire core twisted body, The melting point of at least one of the plurality of linear members is set lower than the melting point of the sheath.

  In this power cable, since the holding means has a plurality of linear members composed of at least two wound around the outer periphery of the wire core twisted body, it is not necessary to use tape or extrusion interposition as the holding means, thereby improving productivity. Can do. In addition, it is possible to reduce dust in terminal processing when a tape is used as the holding means.

  Further, since the melting point of at least one of the plurality of linear members is set lower than the melting point of the sheath, at least one of the plurality of linear members can be melted by extrusion molding of the sheath, and the terminal Waste in processing can be greatly reduced, and workability of terminal processing can be improved.

  Therefore, with such a power cable, workability of terminal processing can be improved and productivity can be improved.

  The invention according to claim 2 is the power cable according to claim 1, wherein a melting point of at least one of the plurality of linear members is set to be equal to or higher than a melting point of the sheath.

  In this power cable, since at least one melting point of the plurality of linear members is set to be equal to or higher than the melting point of the sheath, at least one of the plurality of linear members is not melted by extrusion molding of the sheath. The twisted state of the core twisted body can be stably maintained.

  The invention according to claim 3 is a method for manufacturing a power cable, wherein a first step of forming a wire core stranded body by twisting a plurality of insulated wire cores, and at least one melting point is set lower than the melting point of the sheath. A second step of winding the plurality of linear members wound around the outer periphery of the twisted wire core, and a third step of covering the outer periphery of the twisted wire core with a sheath by extrusion molding.

  In this power cable manufacturing method, the process of winding the tape around the core of the wire core and the process of providing the extrusion intervention can be reduced, and the productivity of the power cable can be improved. In addition, it is possible to reduce dust in terminal processing when a tape is used as the holding means.

  In addition, since at least one of the plurality of linear members wound around the wire core twisted body in the second stroke is melted by the extrusion molding of the sheath in the third stroke, the dust in the terminal processing is greatly reduced. And the workability of terminal processing can be improved.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a power cable that can improve the workability of terminal processing and can improve productivity, and a method for manufacturing the power cable.

1 is a perspective view of a power cable according to an embodiment of the present invention. It is a perspective view of the state before extruding the sheath of the power cable concerning an embodiment of the invention. It is the schematic when a linear member is wound around the core twisted body of the electric power cable which concerns on embodiment of this invention.

  A power cable and a method for manufacturing the power cable according to the embodiment of the present invention will be described with reference to FIGS.

  The power cable 1 according to the present embodiment includes a wire core twisted body 5 obtained by twisting a plurality of insulated wire cores 3, a holding unit 7 that holds the twisted state of the wire core twisted body 5, and the holding unit 7. A sheath 9 that is covered by extrusion molding is provided on the outer periphery of the held wire core strand 5.

  And the holding means 7 has the two linear members 11 and 13 wound around the outer periphery of the wire core twisted body 5, and the melting point of the linear member 13 is set lower than the melting point of the sheath 9.

  Further, the melting point of the linear member 11 is set to be equal to or higher than the melting point of the sheath 9.

  As shown in FIG. 1 to FIG. 3, the wire core twisted body 5 is formed by twisting a plurality of insulated wire cores 3 whose outer periphery is covered with insulation. The insulated wire core 3 has, for example, 2 to 4 cores and a size of 1.25 sq to 38 sq. The wire core twisted body 5 is filled with inclusions 15 between the insulated wire cores 3, and the twisted state is held by the holding means 7 provided on the outer periphery.

  The holding means 7 includes two linear members 11 and 13. The linear member 11 is made of plastic fiber such as polyester having heat resistance equal to or higher than the melting point of the sheath 9. The linear member 13 is made of, for example, nylon having a melting point lower than that of the sheath 9.

  Such linear members 11 and 13 are wound around the outer periphery of the wire core twisted body 5 at the same pitch in the winding direction of the S twist and the Z twist by a bobbin detachable winding device (not shown). In addition, a winding device with a high rotational speed, that is, a device with a high linear speed for feeding the linear members 11 and 13 is selected.

  Here, the pitch P1 between the linear members 11 and between the linear members 13 is set to 2 to 6 times the outer diameter of the wire core twisted body 5, and the pitch P2 between the linear members 11 and 13 is The outer diameter of the core twisted body 5 is set to 1 to 3 times. If these pitches are set large, the twisted state of the wire core strand 5 may be broken when the wire members 11 and 13 are wound around the wire core strand 5 and when the sheath 9 is extruded.

  The linear members 11 and 13 have a strength of at least 30 N / piece or more so as to withstand the tension in consideration of the centrifugal force of the winding device. A sheath 9 is provided on the outer periphery of the wire core twisted body 5 around which the linear members 11 and 13 are wound.

  The sheath 9 is made of, for example, vinyl chloride. The sheath 9 is extrusion-molded on the outer periphery of the core wire 5 around which the linear members 11 and 13 are wound by an extrusion molding device (not shown) to cover the outer periphery of the core wire 5.

  At this time, the linear member 11 is not melted by heat at the time of extrusion molding, and maintains the twisted state of the wire core twisted body 5. Moreover, the linear member 13 is melted by heat at the time of extrusion molding, and is intervened and disconnected on the outer periphery and inside of the core wire 5. Thereby, in the terminal process, the removal work of the linear member 13 is reduced, and the dust in the terminal process can be greatly reduced.

  The melting point of the linear member 13 is preferably set 80 to 40 ° C. lower than the resin temperature of the sheath 9. For example, when the resin temperature of the sheath 9 is 180 ° C., the linear member 13 has a melting point of 100 to 140 ° C. By such setting, air cooling of the linear member 13 after resin discharge of the sheath 9 can be promoted.

  Next, a method for manufacturing the power cable 1 will be described. First, a plurality of insulated wire cores 3 are twisted to form a twisted wire core 5 (first step). Next, the linear members 11 and 13 are wound around the outer periphery of the wire core strand 5 by the winding device (second step). And by the extrusion molding apparatus, the sheath 9 is extrusion-molded on the outer periphery of the wire core twisted body 5 around which the linear members 11 and 13 are wound, and the outer periphery of the wire core twisted body 5 is covered with the sheath 9 (third process). .

  By such a manufacturing method of the power cable 1, the twisted state of the wire core strand 5 is held by the linear member 11, and the linear member 13 is melted by heat at the time of extrusion molding of the sheath 9, and the holding means in the terminal processing 7 can be reduced, and garbage in the terminal processing can be greatly reduced.

  In addition, the production line speed is faster than the structure using the tape winding that moves the self-weight taping head, and it is not necessary to pass through the extrusion line twice as in the structure using the extrusion intervention. Can be improved.

  In such a power cable 1, since the holding means 7 has the two linear members 11 and 13 wound around the outer periphery of the wire core twisted body 5, it is not necessary to use tape or extrusion interposition as the holding means, and productivity Can be improved. In addition, it is possible to reduce dust in terminal processing when a tape is used as the holding means.

  Further, since the melting point of the linear member 13 is set lower than the melting point of the sheath 9, the linear member 13 can be melted by extrusion molding of the sheath 9, and the dust in the terminal processing can be greatly reduced. The terminal processing workability can be improved.

  Therefore, with such a power cable 1, it is possible to improve the workability of terminal processing and improve productivity.

  Further, since the melting point of the linear member 11 is set to be equal to or higher than the melting point of the sheath 9, the linear member 11 is not melted by the extrusion molding of the sheath 9, and the twisted state of the wire core twisted body 5 is stably maintained. can do.

  Furthermore, in the manufacturing method of the power cable 1, the process of winding the tape around the core wire 5 and the process of providing the extrusion intervention can be reduced, and the productivity of the power cable 1 can be improved. In addition, it is possible to reduce dust in terminal processing when a tape is used as the holding means.

  Further, in the second stroke, the linear member 13 wound around the wire core twisted body 5 is melted by the extrusion molding of the sheath 9 in the third stroke, so that dust in the terminal processing can be greatly reduced. The workability of terminal processing can be improved.

  In the power cable according to the embodiment of the present invention, the minimum number of linear members is two, but at least one linear member lower than the melting point of the sheath and the melting point of the sheath are included. If at least one of the above linear members is included, two or more may be used.

DESCRIPTION OF SYMBOLS 1 ... Electric power cable 3 ... Insulated wire core 5 ... Wire core twisted body 7 ... Holding means 9 ... Sheath 11, 13 ... Linear member

Claims (3)

A wire core twisted body in which a plurality of insulated wire cores are twisted together, a holding means for holding the twisted state of the wire core twisted body, and an outer periphery of the wire core twisted body held by the holding means is coated by extrusion molding. A power cable having a sheath
The holding means includes a plurality of linear members formed of at least two wound around the outer periphery of the wire core twisted body, and at least one melting point of the plurality of linear members is lower than a melting point of the sheath. A power cable characterized by being set. The power cable according to claim 1,
The power cable according to claim 1, wherein a melting point of at least one of the plurality of linear members is set to be equal to or higher than a melting point of the sheath.   A first step in which a plurality of insulated wire cores are twisted together to form a wire core twisted body, and a plurality of linear members in which at least one melting point is set lower than the melting point of the sheath are wound around the outer periphery of the wire core twisted body A method of manufacturing a power cable, comprising: a second step; and a third step of covering the outer periphery of the wire core twisted body with a sheath by extrusion molding.

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