JP2000156124A - Twisted pair of wires and pair cable braided of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a twisted pair of wires having a nearly circular outline for the cross section, and to provide a pair of cables having satisfactory appearance, with small irregularity of the outer shape. SOLUTION: Plural twisted pair of wires 10 coated with a shield layer 15 are braided and covered with a sheath 16 outside thereof so as to form a pair cable 20. In this case, the twisted pair of wires 10 have a pair of insulated wires 13 formed by coating a metal conductor 11 with an insulator 12, and a pair of interposed wires 14 having nearly the same outer diameter as that of the insulated wires 13, and the twist pair wires 10 are twisted into a quad form so that both the pair of insulated wires 13 and both the pair of interposed wires face opposite each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a LAN (Local Area)
The present invention relates to a twisted pair wire used for high-speed transmission such as a network or a serial bus, and an improvement of a twisted pair cable.

[0002]

2. Description of the Related Art In recent years, LANs have been wired to offices. Generally, unshielded twisted pair cables are used for LAN wiring. However, as the frequency increases, the crosstalk between the twisted pair wires that make up the twisted pair cable increases. In order to reduce the crosstalk between the twisted pair wires, it is effective to apply a shield layer to each twisted pair wire. This shield layer is formed by winding a tape-shaped shield material around a twisted pair wire.

[0003]

However, as shown in FIG. 4, two insulated wires 3 are twisted in pairs, and a shield layer 4 is formed.
The cross-sectional shape of the twisted pair wire 5 given in the figure changes in the longitudinal direction. Therefore, a plurality of twisted pair wires 5
Are twisted into a cable, and the outermost layer of the paired cable 7 provided with the sheath 6 has a problem that unevenness is generated in the outer shape and the appearance is deteriorated. In the drawings, reference numerals 1 and 2 denote a metal conductor and an insulator, respectively, that constitute the insulated wire 3.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 comprises a pair of insulated wires formed by covering a metal conductor with an insulator; A twisted pair wire having a pair of intervening wires having substantially the same outer diameter as the wire, and being twisted in a quad shape so that the pair of insulated wires and the intervening wires face each other. According to a second aspect of the present invention, in a pair cable in which a plurality of twisted pair wires to which a shield layer is applied are twisted and a sheath is provided outside the twisted pair wire, the twisted pair wire is formed by coating a metal conductor with an insulator. A pair of insulated wires, and a pair of intervening wires having substantially the same outer diameter as the insulated wires, and the pair of insulated wires and the intervening wires are twisted in a quad shape so as to face each other. It is a pair cable which twisted the twisted wire of Claim 1 characterized by the above-mentioned.

According to the first aspect of the present invention, the twisted pair wire is twisted in a quad shape so that a pair of insulated wires and a pair of intervening wires having substantially the same outer diameter as the insulated wire face each other. Therefore, the profile of the cross section of the twisted pair wire is substantially circular. Therefore, in the paired cable according to the second aspect, in which a plurality of twisted wires are twisted to form a cable and a sheath is formed on the outermost layer, unevenness in the outer shape is reduced, and the appearance is improved.

Further, the twisted pair wire according to claim 1 is
Since it consists of an insulated wire and an intervening wire having substantially the same outer diameter,
The head can be manufactured without difficulty using a quad twisting machine. By the way, if the interposed wire is thinner than the insulated wire,
When twisting is performed using a quad twisting machine, the twist of the thin interposed wire is disturbed, and the twist structure may be broken.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of one embodiment of a twisted pair wire according to the present invention, and FIG. 2 is a sectional view of a pair cable using the twisted pair wire.
In FIG. 1, a twisted pair wire 10 is composed of two insulated wires 13 formed by coating a metal conductor 11 with an insulator 12 made of polyolefin, and two polyethylenes approximately equal in outer diameter of the insulated wire 13. The shield wire 15 is formed by twisting the interposed wires 14 in a quad shape so that the insulated wires 13 and the interposed wires 14 are opposed to each other, and wrapping a laminated tape obtained by laminating aluminum and polyester on the stranded wires to form a shield layer 15. It is. The twisted pair wire 10 has a substantially circular cross-section because the outer diameters of the insulated wire 13 and the intervening wire 14 are substantially equal. The twisted pair wire 10 can be easily manufactured by using a four-head quad twister.

[0008] Then, as shown in FIG. 2, four twisted pair wires 10 were twisted and the sheath 16 was covered to form a pair cable 20. In the pair cable 20 having such a structure, since the cross section of the twisted pair wire 10 has a shape close to a circle, the surface unevenness is small and the appearance is better than before.

Note that the twisted pair wire 10 is not limited to the structure shown in FIG.
7 may be used. By doing so, the structure twisted in a quad shape can be stabilized. Further, the shield layer 15 may be made of a metal tape, or a metal tape and a composite tape may be used in combination. Further, the intervening wire 14 may be made of a thermoplastic resin such as PVC in addition to polyethylene, or may be a cotton yarn covered with a thermoplastic resin. By making the equivalent permittivity of the intervening wire 14 smaller than the equivalent permittivity of the insulator 12, an increase in the attenuation caused by the provision of the intervening wire 14 can be suppressed. Further, the number of twisted pair wires 10 constituting the pair cable 20 is not limited to four.

(Example) Next, an example of the present invention will be described in detail. 2, the insulated wire 13 has an outer diameter of 0.65.
A metal conductor 11 made of soft copper having a thickness of 1 mm is coated with an insulator 12 made of polyethylene so that the outer diameter of the insulation becomes 1.4 mm. The intervening wire 14 is made of polyethylene having the same outer diameter as the insulated wire 13. Also, the shield layer 15
Is aluminum (10 µm thick) and polyester (12 µm thick)
Made of laminated tape. Four twisted pair wires 10 having such a configuration are twisted, and a sheath 16 having a thickness of 0.6 mm is provided to form a pair cable 20. Here, the twist pitch of the pair of the four twisted pair wires 10 is 43
mm, 48 mm, 61 mm, and 74 mm (different to reduce electromagnetic coupling). The obtained pair cable 20 had less unevenness on the surface and was excellent in appearance.

[0011]

According to the first aspect of the present invention, a twisted pair wire having a substantially circular cross section can be obtained. Also,
According to the second aspect of the present invention, a plurality of twisted pair wires according to the first aspect of the present invention are twisted to form a cable,
By forming a sheath on the outermost layer, there is an excellent effect that a pair cable having good appearance can be obtained with small irregularities occurring in the outer shape.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a twisted pair wire according to the present invention.

FIG. 2 is a sectional view of a pair cable using the twisted pair wire.

FIG. 3 is a cross-sectional view of another embodiment of the twisted pair wire.

FIG. 4 is a sectional view of a pair cable using a conventional twisted pair wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Twisted pair wire 11 Metal conductor 12 Insulator 13 Insulated wire 14, 17 Intervening wire 15 Shield layer 16 Sheath 20 Pair cable

Claims (2)

[Claims] 1. A pair of insulated wires each having a metal conductor covered with an insulator, and a pair of intervening wires having an outer diameter substantially equal to the insulated wires. A twisted pair wire which is twisted in a quad shape so as to face each other. 2. In a pair cable in which a plurality of twisted pair wires provided with a shield layer are twisted and a sheath is provided on the outside thereof, the twisted pair wire is a pair of insulated wires formed by coating a metal conductor with an insulator. And a pair of intervening wires having substantially the same outer diameter as the insulated wire, and the pair of insulated wires and the intervening wires are twisted in a quad shape so as to face each other. A pair cable obtained by twisting the twisted wires according to 1.