JP2013235693A - Multicore cable and process of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multicore cable capable of obtaining excellent electrical properties and provide a process of manufacturing the same.SOLUTION: The multicore cable includes: a plurality of twist pair electric wires with shields 31 formed by twisting a pair of electric wires of small diameter 33; a collective shield layer 46 that covers the surrounding of the plurality of twist pair electric wires with shields 31; and a sheath 47 that covers the surrounding of the collective shield layer 46, wherein each of the plurality of twist pair electric wires with shields 31 is turned and twisted to be assembled.

Description

  The present invention relates to a multicore cable having a plurality of small-diameter wires and a method for manufacturing the same.

  A high-speed interface cable including a signal line and a power line for high-frequency transmission is known (for example, see Patent Document 1). The cable described in Patent Document 1 has a central interposition in the sheath, and a coaxial signal line formed with an even number of pairs of four or more cores around it is almost the same distance from the central portion of the central interposition as viewed from the cable cross section. The + Vcc line of one or a plurality of small-diameter insulated power supply lines covered with insulation is inserted in the gap between the plurality of coaxial signal lines.

JP 2010-33879 A

In recent years, peripheral cables for connecting peripheral devices to personal computers have been transmitted at high speed, and the frequency band used has expanded to several GHz. In addition, transmission of differential signals has become the mainstream as a transmission method of digital signals such as video. When transmitting a differential signal in such a high frequency band, it is required to suppress the attenuation amount in the cable.
However, in a cable provided with a shielded twisted pair wire (STP) as a signal line, a drop in attenuation (suck out) at a high frequency of the twisted pair wire occurs.

  An object of the present invention is to provide a multicore cable capable of obtaining good electrical characteristics and a method for manufacturing the same.

A multi-core cable capable of solving the above-mentioned problems is a plurality of shielded twisted pair wires in which a pair of small-diameter wires are twisted and covered with a shield layer,
A collective shield layer covering the periphery of the plurality of shielded twisted pair wires;
A sheath covering the periphery of the collective shield layer,
Each of the plurality of shielded twisted pair wires is twisted and assembled while being twisted.

  In the multicore cable of the present invention, it is preferable that the plurality of shielded twisted electric wires are twisted at a twist amount of 10 to 20 revolutions per meter.

  In the multi-core cable of the present invention, it is preferable that the twisted direction of the plurality of shielded twisted wires is the same as the twisted direction of the shielded twisted wires.

  The multi-core cable of the present invention preferably includes an electric wire other than the shielded twisted pair electric wire.

The manufacturing method of the multi-core cable of the present invention is a method of twisting a pair of small-diameter wires to make a plurality of twisted wires, covering the twisted wires with a shield layer to form a shielded twisted wire, and a plurality of the shields Twist the attached twisted wires while twisting them together,
A plurality of the shielded twisted pair wires that have been assembled are covered with a batch shield layer and a sheath in order.

  In the method for producing a multi-core cable of the present invention, it is preferable to twist a plurality of shielded twisted wires with a twist amount of 10 to 20 revolutions per meter.

  In the manufacturing method of the multi-core cable of the present invention, it is preferable that the plurality of shielded twisted wires be twisted in the same direction as the twisted direction of the shielded twisted wires.

  In the manufacturing method of the multi-core cable of the present invention, it is preferable that electric wires other than the shielded twisted pair wire are assembled together with the shielded twisted pair wire.

  According to the present invention, a plurality of shielded twisted pair wires shielded by twisting a pair of small-diameter wires are twisted together while being twisted to suppress a sudden drop in attenuation in the high frequency band. And good electrical characteristics can be obtained.

It is sectional drawing of the multicore cable which shows the structure of the multicore cable which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the frequency of the signal to transmit, and attenuation amount. It is sectional drawing of the multicore cable which shows the other structural example of a multicore cable.

Hereinafter, an example of an embodiment of a multicore cable and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the multi-core cable 11 has a plurality (four in this example) of shielded twisted wires 31. These shielded pair-twisted wires 31 are obtained by twisting a pair of small-diameter wires 33 and shielding them. The thin wire 33 constituting the shielded twisted pair wire 31 is formed by providing the insulating layer 2 around the center conductor 1. The periphery of the pair of small-diameter wires 33 is covered with the shield layer 3. Inside the shield layer 3, the drain wire 4 may be disposed along the thin wire 33. Such a shielded twisted pair wire 31 has the shield layer 3 and thus has noise resistance and is advantageous for high-speed transmission lines.

The multi-core cable 11 has, for example, a dual simplex structure in which signals are transmitted and received in two bidirectional lanes by a shielded twisted pair wire 31 and can transmit and receive signals in two channels. .
As the thin wire 33 constituting the shielded twisted pair wire 31, a wire thinner than the AWG 30 according to the AWG (American Wire Gauge) standard is used.

  The plurality of shielded paired electric wires 31 are twisted together while being twisted, and the twisting direction is the same as the twisting direction of each shielded paired electric wire 31. The twisting amount of the shielded twisted pair wire 31 is preferably 10 to 20 rotations per meter. The amount of twist is preferably equal to or less than the number of twists of the shielded twisted pair wire 31, in other words, the twist pitch of the shielded twisted twisted wire 31 is preferably equal to or greater than the twist pitch of the shielded twisted twisted wire 31. More preferably, the twisting pitch of the shielded twisted pair wire 31 is the same as or approximately the same as the twist pitch of the shielded twisted wire 31. The twist pitch is determined by the flexibility, flexibility, and workability of the thin wire 33. The amount of twist can then be determined.

  The multicore cable 11 has wires other than the shielded twisted pair wire 31, for example, insulated wires 41 and 42 such as a power cable, a low-speed signal cable, and a ground cable. In addition, it may replace with these insulated wires 41 and 42, and may provide a thin diameter coaxial wire, or may provide both the insulated wires 41 and 42 and a thin diameter coaxial wire, respectively. Moreover, the structure which accommodated only the multiple twisted pair twisted electric wires 31 may be sufficient.

  The shielded twisted pair wire 31 is spirally arranged around the insulated wires 41 and 42, and the periphery thereof is sequentially covered with the presser winding 45, the collective shield layer 46, and the sheath 47.

  As the presser winding 45, for example, a resin tape or a paper tape formed from a polyethylene terephthalate (PET) resin or a polytetrafluoroethylene (PTFE) resin excellent in heat resistance, wear resistance and the like is used. As the collective shield layer 46, for example, a braided tin-plated copper wire or copper alloy wire is used. The collective shield layer 46 may be one in which a plurality of copper wires or copper alloy wires are spirally wound, and a copper foil or an aluminum foil is formed on a resin tape made of polyethylene terephthalate (PET) resin. It may be one wrapped with a metal resin tape.

  The sheath 47 is formed of, for example, an insulating resin such as polyvinyl chloride (PVC) or polyolefin resin. Non-halogen polyolefin-based resins include mixtures of elastomers such as ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), and styrene ethylene butylene styrene block copolymer (SEBS). Moreover, what added a weathering agent, antioxidant, and anti-aging agent to polyethylene (PE) may be used. In addition, as the sheath 47 using this polyethylene (PE), the non-flame retardant thing which does not contain a flame retardant may be sufficient.

Next, an example of a method for manufacturing the multicore cable 11 will be described.
First, the thin wire 33 is fed out from the two supply reels, and the supply reels are rotated as a pair, whereby the thin wires 33 are twisted together to form a paired wire. When the drain wire 4 is attached, the two thin electric wires 33 and the drain wire 4 are twisted together.

  Then, the shield layer 3 is formed by winding a metal resin tape or a metal strand around the twisted electric wire. The twisted electric wire may be wound once, and the twisted electric wire may be unwound and wound with a metal resin tape or a metal wire. Alternatively, the metal resin tape or the metal wire may be wound before the antitwisted wire is wound. A metal resin tape or a metal strand is wound according to the structure of the shield layer 3. The shielded twisted pair electric wire 31 made is wound up once.

  The required number of shielded twisted wires 31 and insulated wires 41 and 42 (four cables in the case of FIG. 1) are unwound from each reel, and the insulated wires 41 and 42 are arranged on the inner side to follow them. And twisting the shielded twisted pair wire 31 and winding it on a take-up reel. At this time, each shielded twisted pair wire 31 is twisted and gathered around the insulated wires 41 and 42, but each shielded twisted pair wire 31 itself is twisted and gathered together. In this way, a cable core in which a plurality of shielded twisted pair wires 31 are twisted and twisted around the insulated wires 41 and 42 is formed. When the shielded twisted pair wires 31 are twisted together, the shielded twisted pair wires 31 may be further twisted in the twist direction. Alternatively, when twisting the shielded twisted pair wire 31 (twisting in the direction opposite to the twist of the wire), the twisted cycle is made smaller than the twisting cycle, so that the shielded twisted wire 31 is twisted. The electric wire 31 is twisted in the same direction as the twist.

  Thereafter, the cable core composed of the insulated wires 41 and 42 and the shielded twisted pair wire 31 is covered with the presser winding 45 and the collective shield layer 46, and further, an insulating resin is extruded around the sheath 47 to form a sheath 47. Form.

  According to the multi-core cable 11 according to the present embodiment manufactured as described above, each of the shielded twisted pair wires 31 obtained by twisting a pair of small-diameter wires 33 is twisted and assembled. The shield layer 3 of the shielded twisted pair wire 31 is tightened. Thereby, it is considered that a sudden drop (suckout) of the attenuation amount in the high frequency band of the shielded twisted pair wire 31 can be suppressed, and good electrical characteristics can be obtained.

The direction in which the shielded twisted pair 31 is twisted is preferably the same as the twist direction of the shielded twisted pair 31 itself. By twisting the plurality of shielded twisted wires 31 together, the shielded twisted wires 31 can be twisted in the same direction as the twist direction by not twisting back or by reducing the number of twists.
Moreover, accumulation | storage of the twist of each small diameter electric wire 33 can be effectively prevented by making the frequency | count of twisting the twisted pair twisted electric wire 31 below into the frequency | count of twisting the same electric wire.

In this way, when the shielded twisted pair wires 31 are twisted and assembled (the twisting pitch is equal to the twisting pitch of the thin wires 33 and opposite to each other) and when they are assembled without twisting, the transmission signal The results shown in FIG. 2 were obtained. The dimensions of the multicore cable whose measurement results are shown in FIG. 2 are as follows.
The conductor of a thin wire is a twist of seven conductors with a diameter of 0.06 mm.
The diameter of the thin wire is 0.5mm.
The shield layer structure of the shielded twisted pair wire is a spirally wound tin-plated annealed copper wire with a diameter of 0.06 mm.
The structure of the collective shield layer is a spirally wound tin-plated annealed copper wire with a diameter of 0.08 mm.
The outer sheath of the multi-core cable is an extruded polyethylene.

  As shown in FIG. 2, in the multi-core cable (shown by the solid line in FIG. 2) in which the shielded twisted pair wires 31 are assembled without being twisted, a suckout in which the attenuation amount suddenly falls in the high frequency band (7 GHz). As a result, the amount of attenuation increases rapidly. On the other hand, in the multi-core cable 11 (shown by a dotted line in FIG. 2) according to the present embodiment in which the shielded twisted pair wires 31 are twisted and gathered, a suckout in which the attenuation amount suddenly drops occurs in the high frequency band. I did not.

  From this, if the multi-core cable 11 is formed by gathering the shielded twisted pair wires 31 while twisting, it is possible to suppress a suck-out in which the attenuation amount suddenly drops in a high frequency band, and good electrical characteristics can be obtained. I was able to confirm.

  In the multicore cable 11 described above, the shielded twisted pair wires 31 are twisted and assembled around the insulated wires 41 and 42, but the arrangement inside the cable core is limited to the multicore cable 11 described above. Not. For example, like the multi-core cable 11A shown in FIG. 3, even if the insulated electric wire 42 is arrange | positioned between the shielded pair twisted electric wires 31 in the outer peripheral side of the shielded pair twisted electric wires 31 twisted together while twisting, it gathers good.

  Moreover, the number of the shielded twisted pair wires 31 and the insulated wires 41 and 42 in the multicore cable 11 of the above embodiment is not limited to the forms shown in FIGS.

1: central conductor, 2: insulation layer, 3: shield layer, 11, 11A: multi-core cable, 31: shielded twisted wire, 33: thin wire, 41, 42: insulated wire, 46: collective shield layer, 47: Sheath

Claims (8)

A plurality of shielded twisted wires in which a pair of small-diameter wires are twisted and covered with a shield layer;
A collective shield layer covering the periphery of the plurality of shielded twisted pair wires;
A sheath covering the periphery of the collective shield layer,
A multi-core cable, wherein each of the plurality of shielded twisted pair wires is twisted and assembled while being twisted. The multi-core cable according to claim 1,
The multi-core cable, wherein the plurality of shielded twisted wires are twisted at a twist amount of 10 to 20 revolutions per meter. The multi-core cable according to claim 1 or 2,
The multi-core cable, wherein the twisted direction of the plurality of shielded twisted wires is the same as the twisted direction of the shielded twisted wires. The multi-core cable according to any one of claims 1 to 3,
A multi-core cable comprising an electric wire other than the shielded twisted pair electric wire. Twist a pair of small-diameter wires to make a plurality of twisted wires, cover the twisted wires with a shield layer to make a shielded twisted wire, and twist and twist each of the shielded twisted wires with a twist. Gather,
A method of manufacturing a multi-core cable, wherein a plurality of the shielded twisted pair wires that are assembled are sequentially covered with a collective shield layer and a sheath. It is a manufacturing method of the multi-core cable according to claim 5,
A method for producing a multicore cable, wherein a plurality of shielded twisted wires are twisted at a twist amount of 10 to 20 rotations per meter. It is a manufacturing method of the multi-core cable according to claim 5 or 6,
A method of manufacturing a multi-core cable, wherein a plurality of shielded twisted pair wires are twisted in the same direction as the twist direction of the shielded twisted wires. It is a manufacturing method of the multi-core cable according to any one of claims 5 to 7,
A method of manufacturing a multi-core cable, wherein the shielded twisted pair wires are combined with wires other than the shielded twisted pair wires.

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