JP2002117731A - Flat cable for lan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat cable for a LAN for preventing mutual interference between unit electric wires, enhance the efficiency of fitting work of a connector, and improving a crosstalk characteristic between unit electric wires. SOLUTION: Plural sets of unit electric wires 2 formed by connecting in parallel two electric wires 5 are alternately arranged vertically in the width direction of a conductive tape 1 on the top and bottom sides of the conductive tape 1, and a shield 9 is formed in the periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cable for LAN used for wiring between an automobile and various communication devices.

[0002]

2. Description of the Related Art A twisted pair wire obtained by twisting a pair of conductive wires is:
Since it is inexpensive, lightweight, and easy to lay, it is widely used in LAN cables. As the type of twisted pair wire, STP (Shielded Twisted-Pair)
wire; UTP (Unshielded Twisted-Pair wire; without shielded earth)
Unshielded twisted pair cable)
For P, a plurality of categories are defined by EIA / TIA (Electronic Industries Association of America / Telecommunications Industry Association of America) or the like according to a transmittable band. Such a LAN cable is used by being connected to a modular connector such as RJ-45.

FIG. 6 shows an LA made of unshielded twisted pair wires.
It is a schematic sectional drawing which shows the conventional example of the cable 100 for N.

In this LAN cable 100, a pair of electric wires 101 are twisted at a predetermined pitch to form a twisted pair wire 102, and four sets of the twisted pair wires 102 are twisted at a predetermined pitch. Covering part 1 made of resin such as PVC (polyvinyl chloride)
03 is formed.

In this LAN cable 100, in order to improve crosstalk characteristics and impedance characteristics between the twisted pair wires 102, the twist pitch of the pair of wires 101 is made different in each twisted pair wire 102, and Each twisted pair wire 102 is twisted.

[0006]

However, in the LAN cable 100 as described above, if it is pressed or bent from the outside during the assembling process or the laying process, the twisted pair wires 102 interfere with each other. . As a result, the twisted pair wires 102 come into contact with each other with a strong force to damage the cable 100, or the twisted pair wires 10
The twisting form of the two twists and the like, and the crosstalk characteristics and impedance characteristics between the twisted pair wires 102 become unstable. In particular, with a category 5 LAN cable that guarantees a transmission speed of 100 Mbit / s, such a problem cannot be ignored.

When the modular connector is attached to the end of the LAN cable 100, the twist of the end of each electric wire 101 is loosened and the twist is fixed at the end of the LAN cable 100 so as to be in a parallel state. After doing
It is necessary to insert and attach the end of the cable 100 to the modular connector, which causes a problem that the connector mounting workability is poor.

Therefore, as shown in FIG.
Are connected in a parallel state.

However, the flat cable 110 for LAN has a problem that the electric wires 111 are too close to each other, so that mutual interference of the electric wires 111 is likely to occur, and that the crosstalk characteristics of the cables are easily deteriorated. There is a problem that it is difficult to reach the standard.

It is an object of the present invention to provide a LAN flat cable which can prevent mutual interference between unit wires, has excellent connector mounting workability, and has excellent crosstalk characteristics between unit wires. The point is to provide.

[0011]

According to a first aspect of the present invention, there is provided a flat cable for LAN according to the present invention, wherein the flat cable extends in parallel on both upper and lower sides of a conductive tape.
A plurality of sets of unit wires having the present lead wires are alternately arranged vertically so that their axial directions are aligned with the longitudinal direction of the conductive tape, and do not overlap each other in the vertical direction along the width direction of the conductive tape. And a coating portion is formed on the outer periphery thereof.

According to a second aspect of the present invention, the conductive tape may be flat along its width direction, and as described in a third aspect, the conductive tape may be flat in the width direction. And the unit wires may be accommodated and arranged in concave grooves between the waves on both the upper and lower surfaces of the conductive tape and arranged on substantially the same plane.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a LAN flat cable according to a first embodiment of the present invention will be described.

As shown in FIGS. 1 and 2, this LAN flat cable comprises a conductive tape 1 and a plurality of sets (four sets in this embodiment) disposed on both upper and lower sides of the conductive tape 1. ), And a covering portion 9.

The conductive tape 1 is a tape-shaped member formed of a conductive material. For example, a metal tape such as a copper foil tape or an aluminum foil tape can be used.

Each unit electric wire 2 extends in a parallel state.
It is configured to include the conducting wire 3. In the present embodiment, a two-core parallel cable having a configuration in which an electric wire 5 having a covering 4 formed around a conducting wire 3 is connected to each other via one side of the covering 4 as the unit electric wire 2 is used. ing. In addition,
Although the electric wires 5 may not be connected to each other and may be in a disjointed state, it is easier to manufacture a flat cable by connecting both electric wires 5 as in the present embodiment. In addition, since the distance between the two electric wires 5 is kept as constant as possible after manufacturing, there is an advantage that the impedance characteristics between the conductive wires 3 can be stabilized. The conductor 3 may be a round conductor having a substantially circular cross section or a flat conductor having a substantially rectangular cross section.

Each of the unit wires 2 is separated from the conductive tape 1 so that the axial direction thereof is aligned with the longitudinal direction of the conductive tape 1 and the width direction thereof is aligned with the width direction of the conductive tape 1. They are arranged alternately up and down so that they do not overlap each other in the up and down direction. Therefore, the conductive tape 1 always intervenes between the unit wire 2 on the upper surface side and the unit wire 2 on the lower surface side of the conductive tape 1 and is adjacent to the conductive tape 1 on the upper surface side or the lower surface side. The unit electric wires 2 are configured to be separated from each other with an interval dimension equal to or larger than the width dimension of the unit electric wires 2. The distance between the unit wires 2 adjacent to each other on the upper surface or the lower surface of the conductive tape 1 is set so as to improve the crosstalk characteristics between the unit wires 2 and to improve the flat cable for LAN according to the second embodiment described later. It is preferable to provide a sufficient predetermined interval dimension equal to or larger than the width dimension of the unit electric wire 2 so that the unit electric wire 2 can be deformed.

Further, as described above, the covering portion 9 is formed on the outer periphery of the assembled form in which the unit wires 2 are disposed on the upper and lower surfaces of the conductive tape 1. In the present embodiment, the insulating sheet material 9a made of insulating resin is stuck on the upper and lower surfaces of the above-mentioned aggregated form in close contact with its outer shape via an adhesive or the like,
The covering portion 9 is formed by bonding the insulating sheet materials 9a together via an adhesive or the like on both sides of the aggregated form. In addition, you may form the coating part 9 by extrusion-coating resin.

The flat cable for LAN constructed as described above is a cable conforming to the category 5 regulations.
For example, an RJ45 type connector is attached to an end of the connector, and the connector is connected to a connector of various electronic devices, so that the connector is used for wiring between various communication devices constituting a LAN. When attaching the connector to the end of the cable, the sheath 9 and the conductive tape 1 were removed at the end of the cable, and the wires 5 were exposed and processed so as to be arranged in parallel. Attach to the end of the cable.

According to the LAN flat cable constructed as described above, each unit electric wire 2 is arranged on both upper and lower sides of the conductive tape 1 with its axial direction aligned with the longitudinal direction of the conductive tape 1. The unit wires 2 on the upper surface side of the conductive tape 1 and the units on the lower surface side of the conductive tape 1 are alternately arranged vertically so as not to overlap each other in the vertical direction along the width direction of the conductive tape 1. The electric wires 2 are electromagnetically shielded by the conductive tape 1 interposed therebetween, and the unit electric wires 2 adjacent to each other on the upper surface side or the lower surface side of the conductive tape 1 Since the wires are separated from each other by a sufficient distance equal to or larger than the width of the wires 2, it is difficult to exert an electromagnetic influence on each other. It is.

The unit wires 2 are disposed so as not to overlap each other in the vertical direction along the width direction of the conductive tape 1, and are arranged between the unit wires 2 on the upper surface side or the lower surface side of the conductive tape 1. Since there are no inclusions in the cable, even if a compressive force acts on the flat cable for LAN in the thickness direction, the unit wires 2 are less likely to interfere with each other. Thereby, specifically, as in the conventional LAN cable 100 shown in FIG.
It is possible to prevent the cable 100 from being damaged by mutual contact with each other, or to prevent the crosstalk characteristic and the impedance characteristic from becoming unstable due to the collapse of the aggregated form of the twisted pair wires 102. Instability of crosstalk characteristics and impedance characteristics between the unit wires 2 can be prevented.

Further, in the present flat cable for LAN, since the electric wires 5 including the respective conducting wires 3 and the unit electric wires 2 are not twisted, when the connector is connected to the end thereof,
Untwist each wire 101 as before, or
There is no need to correct that twisting habit. For this reason, the connector workability is excellent.

Further, since the LAN flat cable has a flat shape, it is easy to bend in a direction orthogonal to the plane direction, and the bending form is 2 mm in diameter of the electric wire 5.
There is an advantage that it can be reduced to the main level. In addition, since the wires 5 are bent with substantially the same radius of curvature when bent in such a manner, there is an advantage that the arrangement of the wires 5 is not easily collapsed.

Further, since it is not necessary to bend the conductive tape 1 in the width direction, a flat cable can be easily and quickly manufactured.

Here, a modification of the LAN flat cable according to the first embodiment will be described.

In a first modification shown in FIG. 3, a flat cable 10 is attached to both upper and lower surfaces of a conductive tape 1. Each of the flat cables 10 includes a unit wire portion 12 in which a pair of conductors 13 are buried in a parallel state at a predetermined interval in an insulating material such as a resin, and an interposition portion 1 composed of only a resin body.
6 are provided alternately along the width direction. Such a flat cable 10 is formed by sandwiching a plurality of conductors 13 between a pair of insulating films, or by extruding an insulating resin on the plurality of conductors 13. The flat cables 10 are stuck on the upper and lower surfaces of the conductive tape 1 such that the unit electric wires 12 are alternately arranged vertically so as not to overlap each other in the vertical direction of the conductive tape 1. . As the conductor 13, a rectangular conductor having a substantially rectangular cross section may be used.
A round conductor 13b having a substantially circular cross section may be used as in Modification 2 shown in FIG.

The flat cable for LAN shown in FIG. 3 or FIG. 4 can also provide effects such as excellent crosstalk characteristics as in the case of the above embodiment. In addition, an effect that a flat cable for LAN can be easily manufactured only by attaching the flat cable 10 to both sides of the conductive tape 1 is obtained.

Next, a LAN flat cable according to a second embodiment of the present invention will be described.

The difference from the flat cable for LAN according to the first embodiment will be mainly described.
As shown in FIG. 5, in the flat cable for LAN, instead of the conductive tape 1 which is flat in the width direction used in the flat cable for LAN according to the first embodiment, the flat cable is formed in a wavy shape along the width direction. Each of the unit wires 2 (similar to that in the first embodiment) is housed and arranged in the concave groove portion 1Ba between each wave on the upper and lower surfaces of the conductive tape 1 using the conductive tape 1B thus obtained. They are arranged on the same plane.

That is, the conductive tape 1B is formed in a substantially trapezoidal wave shape along the width direction, and the conductive tape 1B is formed between upper and lower surfaces of the conductive tape 1B between each wave.
A concave groove portion 1Ba extending along the longitudinal direction is formed.
However, on both sides of the conductive tape 1B, the outside of the groove 1Ba is open. Each concave groove portion 1Ba is formed in a cross-sectional shape having a width dimension and a height dimension that can be accommodated and arranged in a posture in which the width direction of the unit electric wire 2 is aligned with the width direction of the conductive tape 1B. When the unit wires 2 are respectively housed and arranged in the concave groove portions 1Ba on the upper and lower surfaces of the conductive tape 1B, the unit wires 2 are arranged on the upper surface side and the lower surface side of the conductive tape 1B. In other words, they are arranged on substantially the same plane in a state where they are alternately arranged.

As a method of forming such an assembly form of the conductive tape 1B and each unit electric wire 2, for example,
As in the first embodiment, after forming a set form in which the unit wires 2 are alternately arranged along the width direction on both upper and lower sides of the conductive tape 1 which is flat in the width direction (FIG. 1
By pressing the aggregated form in the thickness direction, the conductive tape 1 is formed into the corrugated conductive tape 1B by utilizing the shearing force between the unit electric wires 2, and at the same time, the concave grooves 1Ba between the waves are formed. There is a method of accommodating and arranging the unit electric wires 2 or a method of forming the conductive tape 1B in a corrugated shape in advance, and then accommodating and arranging the unit electric wires 2 in the concave grooves 1Ba between the waves.

In the case where the former manufacturing method is applied, since the conductive tape 1 does not need to be bent in the width direction as in the case of the first embodiment, it is easy and quick. A flat cable can be manufactured. Incidentally, in this case, the conductive tape 1B has a more rounded and corrugated shape than the case shown in FIG.

A covering 9 having the same structure as that of the first embodiment is provided on the outer periphery of the assembled form in which a plurality of sets of unit wires 2 are arranged on the upper and lower surfaces of the conductive tape 1B. It is formed.

In the thus constructed flat cable for LAN, the conductive tape 1B is formed in a corrugated shape along the width direction, and each unit wire 2 is connected to each of the upper and lower surfaces of the conductive tape 1B. Are arranged in substantially the same plane by being accommodated and arranged in the concave groove portion 1Ba, so that between the unit wires 2 is electromagnetically shielded by the conductive tape 1B,
The crosstalk characteristics between the unit wires 2 are excellent.

For the same reason as in the first embodiment, the unit wires 2 are less likely to interfere with each other against external force in the vertical direction, preventing cable damage, crosstalk characteristics, and impedance characteristics. And the effects of excellent connector mounting workability can be obtained.

In each of the above-described embodiments, various requirements (characteristic impedance, attenuation) of the flat cable for LAN are used in order to improve the crosstalk characteristics and prevent external noise. As long as it is satisfied, it is preferable that each conductor 3 be in a form close to the conductive tapes 1 and 1B.

[0037]

As described above, in the flat cable for LAN according to the first to third aspects of the present invention, a plurality of sets of unit electric wires having two conductors extending in parallel are electrically conductive in the axial direction. The units are arranged alternately up and down so that they do not overlap each other in the vertical direction along the width direction of the conductive tape in a posture aligned with the longitudinal direction of the tape. Between the unit wires shall be electromagnetically shielded by conductive tape, and between the unit wires on the upper or lower surface of the conductive tape, a sufficient distance equal to or greater than the width of the unit wires shall be provided. This makes it difficult for electromagnetic waves or the like to affect each other, and therefore, the crosstalk characteristics between the unit wires are excellent.

Further, since the unit wires are arranged so as not to overlap with each other, even if a compressive force acts on the LAN flat cable in its thickness direction, the unit wires are not connected to each other. Hard to interfere.

Further, since the wires and unit wires are not twisted, there is no need to untwist the wires when attaching the connector to the end of the cable as in the prior art. Excellent in nature.

In particular, the conductive tape is formed in a wavy shape along the width direction, and each unit electric wire is housed in the concave groove between the upper and lower surfaces of the conductive tape. If the unit wires are arranged and arranged on substantially the same plane, the unit wires adjacent on the plane are electromagnetically shielded by a conductive tape that is always interposed therebetween, so that the unit wires are not connected to each other. Has excellent crosstalk characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a LAN flat cable according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the LAN flat cable according to the first embodiment;

FIG. 3 is a sectional view showing a LAN flat cable according to a first modification.

FIG. 4 is a sectional view showing a LAN flat cable according to a first modification;

FIG. 5 is a sectional view showing a LAN flat cable according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a conventional LAN cable.

FIG. 7 is a diagram showing an example of a LAN flat cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive tape 1B Conductive tape 1Ba Depressed groove part 2 Unit electric wire 3 Conductor 4 Coating part 5 Electric wire 9 Coating part

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shizuya Kawabe 1-14 Nishisuehiro-cho, Yokkaichi-shi, Mie F-term in Sumitomo Wiring Systems Co., Ltd. 5G311 CA01 CB03 CC01 CD03 CE04 5G319 DA01 DB01 DC21 DC22

Claims (3)

[Claims] 1. A plurality of sets of unit wires each having two conductive wires extending in parallel on both upper and lower sides of a conductive tape,
In a posture in which the axial direction is aligned with the longitudinal direction of the conductive tape, while being alternately arranged vertically so as not to overlap each other in the vertical direction along the width direction of the conductive tape,
A flat cable for LAN with a coating on the outer periphery. 2. The LAN flat cable according to claim 1, wherein the conductive tape is flat along a width direction thereof. 3. The conductive tape is formed in a wavy shape along its width direction, and the unit wires are accommodated and arranged in concave grooves between the waves on the upper and lower surfaces of the conductive tape. The LAN according to claim 1, which is disposed on a plane.
For flat cable.