JPH07201229A - Multipair cable - Google Patents

Abstract

PURPOSE:To achieve a thin size of a multipair cable. CONSTITUTION:Plural conductors 2, 2... of which outer circumferential surfaces are coated with enamel 2a are twisted with each other to be a pair twisted wire 4. Around the plural pair twisted wires 4, 4, a protective layer 5 comprising resin having insulation property is formed to embed the pair twisted wires 4, 4.... A shield layer 7 is formed on the outer circumferential surface of the protective layer 5, and a sheath layer 8 is formed on an outer circumferential surface of the shield layer 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-pair cable having a multi-core structure, which is preferably used in, for example, electronic equipment and has a plurality of twisted pair signal lines arranged in parallel with each other.

[0002]

2. Description of the Related Art Conventionally, as a multi-pair cable used in electronic equipment, a pair of twisted core wires around which an insulating paper tape is wrapped or an extruded wire around the twisted core wires is used. A plurality of products coated with an insulating resin such as polyethylene (PE) by molding are arranged in parallel with each other, and a shield layer and a sheath layer are coaxially formed so as to surround these coated core wires. Etc. are known. The multi-pair cable coated with this insulating resin has less hygroscopicity than the multi-pair cable insulated with paper tape, insulation deterioration is less likely to occur, pressure resistance, and the geometric positions of the core wires are correct. It is widely used in various fields because of its excellent characteristics such as excellent cross-talk coupling and high mechanical strength.

[0003]

By the way, in the above-mentioned resin-coated multi-pair cable, in order to obtain the same capacitance as the multi-pair cable insulated by using the paper tape, the thickness of the insulating layer should be increased. Since there is no choice but to avoid it, the outer diameter of the cable inevitably becomes large, and therefore the cost of the cable increases. Moreover, since the polyethylene (PE) is coated around the core wire by extrusion molding, the thickness of the coating layer becomes 50 μm or more, and the polyethylene (P
Even if a special material other than E) is used, it is not easy to make the thickness of the coating layer 50 μm or less, and it is said that the thickness is about 50 μm. Therefore, it is extremely difficult to further reduce the diameter of the conventional multi-pair cable.

The present invention has been made in view of the above circumstances, and it is possible to further reduce the diameter, and moreover, there is no difference in electrical characteristics from the conventional multi-pair cable coated with resin. The purpose is to provide a paired cable.

[0005]

In order to solve the above problems, the present invention employs the following multi-pair cables. That is, a plurality of conductor wires coated with enamel on the outer peripheral surface are twisted with each other to form a twisted pair wire, and a plurality of these twisted wires are arranged in parallel, outside each of these plurality of twisted wires,
A protective layer made of a resin having an insulating property is formed so as to embed these plural twisted wires, a shield layer is formed on the outer peripheral surface of the protective layer, and a sheath layer is formed on the outer peripheral surface of the shield layer. It is characterized by that.

[0006]

In the multi-pair cable of the present invention, a plurality of conducting wires coated with enamel on the outer peripheral surface are twisted together to form a twisted pair wire, which is sufficient even when the thickness of the enamel layer is reduced to about 5 μm. The insulating property can be maintained, and the thickness of the protective layer around the core wire made of twisted wires can be significantly reduced. Therefore, the diameter can be significantly reduced as compared with the conventional multi-pair cable.

[0007]

1 is a sectional view showing a multi-pair cable according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a twisted pair portion of the multi-pair cable. This multi-pair cable 1 has two coated copper wires (conductor wires) 2 having an enamel layer 2a baked on the outer peripheral surface thereof.
2 are twisted with each other and further covered with a urethane layer 3 to form a twisted pair wire 4. These twisted pair wires 4, 4, ...
Arranged in parallel so that each axis is parallel to each other,
A protective layer 5 made of a resin having an insulating property is formed outside the pair of twisted wires 4, 4, ... To embed the pair of twisted wires 4, 4 ,. Restraint tape 6
The shield layer 7 and the shield layer 7 are sequentially formed coaxially, and the sheath layer 8 is formed on the outer peripheral surface of the shield layer 7. A polyurethane resin, a polyethylene (PE) resin, a polyimide resin, a fluororesin, or the like is preferably used as the resin forming the protective layer 5. Here, the thickness of the enamel layer is 5 μm,
The outer diameter of the copper wires 2 and 2 is 35 μm, and the thickness of the urethane layer 3 is 5
.mu.m, and the number of pairs of twisted pair wires 4, 4, ... Is 64. The outer diameter of the multi-pair cable 1 at this time was about 2 mm.

In this multi-pair cable 1, two covered copper wires 2 and 2 having an enamel layer 2a baked on the outer peripheral surface are twisted together, and further covered with a urethane layer 3 to form a twisted pair wire 4. The twisted pair wire 4 is sufficiently kept in insulating property by the enamel layer 2a and the urethane layer 3. Therefore, the insulating property is sufficiently maintained even if the thickness of the protective layer 5 around the twisted pair wires 4, 4, ... Is significantly reduced, and furthermore, the enamel layer 2a, the urethane layer 3, the protective layer 5 are provided.
Since a sufficient capacitance can be obtained by the combination of, the diameter can be significantly reduced as compared with the conventional resin-coated multi-pair cable.

As explained above, the enamel layer 2 is formed on the outer peripheral surface.
The two copper wires 2, 2 on which a has been baked are twisted together to form a twisted pair portion, and the twisted pair portion is further covered with a urethane layer 3 to form a twisted pair wire 4. These twisted pair wires 4, 4, ... Are arranged in parallel, a protective layer 5 is formed outside the twisted pair wires 4, 4, ... so as to embed the twisted pair wires 4, 4 ,. Since the tape 6 and the shield layer 7 are sequentially formed coaxially and the sheath layer 8 is formed on the outer peripheral surface of the shield layer 7, the thickness of the protective layer 5 around the twisted pair wires 4, 4, ... Is significantly reduced. Even in such a case, the insulating property can be sufficiently maintained, and the thickness of the protective layer 5 around the twisted pair wires 4, 4, ... Can be significantly reduced. Therefore, the diameter can be significantly reduced as compared with the conventional multi-pair cable. Moreover, there is no problem in electrical characteristics as compared with the conventional resin-coated multi-pair cable, and there is no problem in practical use.

In the above-mentioned multi-pair cable 1, the twisted pair wire 4 in which the two covered copper wires 2 and 2 are twisted in pairs is used. However, in addition to the above configuration, for example, four covered copper wires 2, Various configurations can be adopted such as a configuration in which 2, ... Are twisted with each other, and a configuration in which the twisted pair wires 4 and 4 are further twisted.

[0011]

As described above, according to the multi-pair cable of the present invention, a plurality of conducting wires each having an outer peripheral surface coated with enamel are twisted together to form a twisted pair wire. Are arranged in parallel, a protective layer made of a resin having an insulating property is formed outside each of the plurality of twisted pair wires so as to fill the plurality of twisted pair wires, and the shield layer is formed on the outer peripheral surface of the protective layer. Since the sheath layer is formed on the outer peripheral surface of the shield layer, sufficient insulation can be maintained even when the thickness of the enamel layer is reduced to about 5 μm, and the core wire made of twisted pair wires The thickness of the protective layer around the can be significantly reduced. Therefore, the diameter can be significantly reduced as compared with the conventional multi-pair cable. Moreover, there is no problem in electrical characteristics as compared with the conventional resin-coated multi-pair cable, and there is no problem in practical use.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a multi-pair cable according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing a multi-pair cable of an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multipair cable, 2 ... Coated copper wire (conductor wire), 2a ... Enamel layer, 3 ... Urethane layer, 4 ... Twisted wire, 5 ... Protective layer, 6
... holding tape, 7 ... shield layer, 8 ... sheath layer.

Claims (1)

[Claims] 1. A plurality of conducting wires each having an outer peripheral surface coated with enamel are twisted together to form a pair twisted wire, and the plurality of pair twisted wires are arranged in parallel, and the outer side of each of the plurality of pair twisted wires is arranged. A protective layer made of an insulative resin is formed so as to embed these twisted pair wires, a shield layer is formed on the outer peripheral surface of the protective layer, and a sheath layer is formed on the outer peripheral surface of the shield layer. A multi-pair cable characterized by