JPH06139853A - Manufacture of cable - Google Patents

Abstract

PURPOSE:To manufacture a CV cable generating no birdcage and having a wire shield lateral winding type solid extrusion sheath structure by a improved method. CONSTITUTION:A wire shielding machine 4 and a sheath extruding machine 5 are installed in tandem. The point where a cable is wound on the wire shielding machine 4 is moved near the crosshead of the sheath extruding machine 5 by one pitch or less of the wire shielding machine 4 to manufacture the cable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cable, and more particularly to a crosslinked polyethylene (hereinafter referred to as CV cable), and to a method for manufacturing a cable which is wire-shielded and whose sheath is extrusion-coated by a solid extrusion method.

[0002]

2. Description of the Related Art When a wire shield system is adopted for a CV cable, a copper tape is spirally wound around the wire shield as a binder, or a tape is wound around the wire shield, and a sheath is extruded and coated thereon. It is generally manufactured.

However, some customers desire a wire shield having a structure in which polyethylene or polyvinyl chloride is directly and fully extruded only by horizontal winding.

The present invention is the latter method for producing a cable having a structure in which polyethylene or polyvinyl chloride is fully extrusion-coated. That is, in the case where polyethylene or polyvinyl chloride is directly subjected to solid extrusion on a cable having a wire shield wound horizontally, the following method can be considered.

(1) Horizontal winding wire shield is applied in a separate step in advance, and then polyethylene or the like is subjected to solid extrusion coating in an extrusion line.

(2) A binder tape is wound around the horizontally wound wire shield, and polyethylene or the like is subjected to full extrusion coating while removing the binder tape on an extrusion line.

(3) A binder tape of the same quality as the sheath material is applied on the horizontally wound wire shield, and polyethylene or the like is fully extruded and coated on the next extrusion line, and the tape of the same material is integrated by the heat during extrusion. I will let you.

[0008]

By the way, in the above-mentioned prior art, when the horizontal winding wire shield cable was extruded, it was slightly stretched at the time of winding the drum after the horizontal winding wire shield work, Due to the heat during extrusion, the shield wire is slightly embedded in the outer conductive layer of the cable, and a phenomenon occurs in which the shield wire is slightly left. This phenomenon is sent to the rear one after another when a long extrusion operation is performed, and the horizontal winding shield expands. That is, there is a problem that it becomes a bird cage shape.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an improved manufacturing method for manufacturing a CV cable of a wire shield horizontal winding type solid extrusion sheath structure in which a bird cage does not occur. And

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a method for manufacturing a cable for a crosslinked polyethylene power cable or the like in which the structure of the shield layer and the sheath comprises a wire shield horizontal winding shield layer in which polyethylene or polyvinyl chloride is directly and fully extruded. A cable manufacturing method characterized in that a wire shield machine and a sheath extruder are installed in a tandem line, and the point where the wire shield is wound around the cable is brought close to the crosshead of the extruder within one pitch of the wire shield. .

[0011]

[Operation] The sheath extruder and the horizontal wire shield machine are arranged in tandem for simultaneous work, without causing a phenomenon in which the shield wire is embedded in the outer conductive layer due to heat during sheath extrusion and is slightly left. It is possible to manufacture a long cable having a uniform structure.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a cross-sectional view of a wire shield full extrusion type CV cable. That is, the central cable conductor 10
A cable core is formed by covering the outer circumference of the inner semiconductive layer 11, the insulator 12, and the outer conductive layer 13. Then, the wire shield 14 is horizontally wound on the thus formed cable core by a wire shield machine, and polyethylene or polyvinyl chloride is extrusion-coated by a sheath extruder to form a full extruded sheath 15.

FIG. 1 is a configuration diagram of a manufacturing line in which the wire shield machine and the sheath (solid) extruder of the embodiment are arranged in tandem. That is, in the cable core 3 sent from the sending core 1 via the caterpillar 2 which is a brake, the wire shield 14 is first wound around the cable core 3 by the wire shield machine 4. Subsequently, the crosshead 6 of the sheath extruder 5 extrusion-covers the outer periphery of the wire shield 14 of the cable core 3 with an insulator of polyethylene or polyvinyl chloride.

The crosshead portion is enlarged and shown in FIG. That is, the crosshead 6 is composed of a mouthpiece 18 and a mandrel 17, and the wire shield 14 from which the polyethylene or polyvinyl chloride resin is horizontally wound from the sheath extruder 5 is fully extruded and covered to form a sheath 15. Of.

At this time, the crosshead 6 of the sheath extruder 5 is required to be extremely close to the point where the wire shield 14 is wound around the cable core 3, and is ideally within 1 pitch. Thus, the shield wires 14 are loosened by the wire pulling tension by the bobbin brake, and the loosened wires are sent later, so that the bird gauge does not occur. If they are not brought close to each other, a bird gauge will be generated in a portion where the drawing tension does not reach in the winding portion.

The distance between the crosshead 6 of the sheath extruder 5 and the wire shield winding portion changes depending on the back tension of the shield wire 14, but the closer this distance is, the more reliable work can be performed. In general, ideally, the distance may be within one pitch of the wire shield 14.

Then, the cable core 3 delivered from the crosshead 6 is taken up by the take-up caterpillar 8 by the take-up machine 9 through the cooling water tank 7. At this time, since the take-up caterpillar 8 is electrically synchronized with the wire shield machine 4,
It is connected to the wire shield machine 4 via the tuning circuit 16 and maintains the wire winding pitch accurately. This is done by detecting the speed of the take-up caterpillar 8 and determining the number of rotations of the wire shield machine 4 by the signal thereof.

[0018]

EFFECT OF THE INVENTION In a cable manufacturing method of a CV cable or the like in which polyethylene, polyvinyl chloride or the like is directly covered by full extrusion by only horizontal winding of the wire shield, a residual phenomenon of the wire shield generally called a bird gauge occurs. According to the cable manufacturing method of the present invention, it is possible to manufacture a cable having a long and uniform structure without producing such a bird gauge.

[Brief description of drawings]

FIG. 1 is a manufacturing line configuration diagram of a wire shield extruder and a sheath extruder showing an embodiment of a cable manufacturing method of the present invention,

FIG. 2 is a CV manufactured by the cable manufacturing method of the present invention.
Cross section of the cable,

FIG. 3 is a cross-sectional view showing details of a crosshead portion.

[Explanation of symbols]

 3 Cable Core 4 Wire Shielding Machine 5 Sheath Extruder 6 Crosshead 10 Cable Conductor 11 Inner Semi-Conductive Layer 12 Insulator 13 Outer Semi-Conductive Layer 14 Wire Shield 15 Solid Extrusion Sheath 17 Mandrel 18 Base

Front page continuation (72) Inventor Mitsuo Yoshimoto 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki "Hitachi Cable Co., Ltd. Hidaka Plant"

Claims (1)

[Claims] 1. In a cable manufacturing method in which polyethylene or polyvinyl chloride is directly and fully extruded into a shield layer of a wire shield horizontal winding in a crosslinked polyethylene power cable or the like, the shield layer and the sheath have a tandem wire shield machine and sheath extruder. A cable manufacturing method characterized in that it is installed on a line and the point where the wire shield is wound around the cable is brought close to the crosshead of the sheath extruder within one pitch of the wire shield.