JP2020017436A - Twist pair cable, and communication cable - Google Patents

Abstract

To provide a twist pair cable capable of achieving a crosstalk without increasing the number of components of a communication cable.SOLUTION: A twist pair cable 10A has a pair of wires 11 twisted each other, and the wire 11 has a plurality of kind of twisted pitch Pto P.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a twisted pair cable and a communication cable including the twisted pair cable.

  A communication cable in which four twisted pair electric wires are bundled and a shield layer and a sheath are provided on the outer periphery thereof is known (for example, see Patent Document 1).

JP 2010-232092 A

  In the communication cable described above, in order to reduce crosstalk, a cross inclusion is interposed between a plurality of twisted pair wires, or only a part of the twisted pair wires is covered with a shield layer. Therefore, there is a problem that the number of members constituting the communication cable is increased.

  An object of the present invention is to provide a twisted pair cable capable of reducing crosstalk without increasing the number of components of a communication cable, and a communication cable including the twisted pair cable.

  [1] A twisted pair cable according to the present invention is a twisted pair cable including a pair of wires twisted with each other, wherein the wires are twisted pair cables having a plurality of types of twist pitches.

  [2] In the above invention, the electric wires may be mutually twisted so that a twist pitch changes periodically.

  [3] In the above invention, the electric wires may be mutually twisted so that a twist pitch changes randomly.

  [4] In the above invention, the twisted pair cable may have electrical insulation and include a jacket in which the electric wire is embedded.

  [5] In the above invention, the jacket may have a sign indicating a specific position of a twist pattern along an axial direction of the twisted pair cable.

  [6] A communication cable according to the present invention is a communication cable including the plurality of twisted pair cables described above, wherein the plurality of twisted pair cables are bundled with each other and extend along the axial direction of the twisted pair cable. The communication cables have different twist patterns.

  [7] A communication cable according to the present invention is a communication cable including the plurality of twisted pair cables described above, wherein the plurality of twisted pair cables are bundled such that the positions of the markers are shifted from each other in the axial direction. Communication cable.

  According to the present invention, since the twisted pair cable has a plurality of types of twist pitches, the twist patterns can be made different from each other when bundling with another twisted pair cable. For this reason, crosstalk can be reduced without using cross inclusions or individual shield layers.

FIG. 1A is a perspective view illustrating a twisted pair cable according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. FIG. 2A is a side view illustrating a state in which a jacket is removed from the twisted pair cable according to the embodiment of the present invention, and FIG. 2B is a side view illustrating the twisted pair cable according to the embodiment of the present invention. Drawing 3 is a figure showing the 1st modification of a twisted pair cable in an embodiment of the present invention, and is a side view showing the state where a jacket was removed from the twisted pair cable. FIG. 4 is a diagram illustrating a second modification of the twisted pair cable according to the embodiment of the present invention. FIG. 5A is a graph showing the crosstalk characteristic of the twisted pair cable in the present embodiment, and FIG. 5B is a graph showing the crosstalk characteristic of the twisted pair cable in Comparative Example 1, and FIG. () Is a graph showing the crosstalk characteristics of the twisted pair cable in Comparative Example 2. FIG. 6 is a sectional view showing a communication cable according to the embodiment of the present invention. FIG. 7 is a diagram illustrating a twist pattern of the first to fourth twisted pair cables according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A and 1B are a perspective view and a cross-sectional view illustrating a twisted pair cable according to the present embodiment, and FIG. 2A is a side view illustrating a state where a jacket is removed from the twisted pair cable according to the present embodiment. FIG. 2B is a side view showing the twisted pair cable in the present embodiment.

  The twisted pair cable 10A in the present embodiment includes a pair of electric wires 11 and a jacket 20, as shown in FIGS. 1 (a) and 1 (b). The twisted pair cable 10A in the present embodiment is used side by side with another twisted pair cable, and is used, for example, by being incorporated into a communication cable 1 or the like described later.

  Each electric wire 11 includes a linear conductor 12 and a covering layer 13 that covers the outer periphery of the conductor 12. The conductor 12 is formed of a single wire or a stranded wire made of a metal material having excellent conductivity such as copper, copper alloy, aluminum, and aluminum alloy. The coating layer 13 is made of an insulating material having electrical insulation such as a resin material. Although not particularly limited, polypropylene (PP) can be exemplified as an example of the resin material forming the coating layer 13.

The pair of electric wires 11 are mutually twisted. Specifically, as shown in FIG. 2 (a), a pair of wires 11, has a first twist pattern 15 as the twisting pitch P ₁ to P ₃ of the electric wire 11 is changed periodically I have. The “twist pattern” in the present embodiment is the entire shape of a pair of electric wires over the entire length along the axial direction of the twisted pair cable, and means a spiral shape accompanying the twist.

The first twist pattern 15 includes three types of sections 151 to 153. In the first section 151, the electric wire 11 is twisted at a _first twist pitch P1, and the first section 151 has a length corresponding to half of the _first twist pitch P1. . Further, in the second section 152, and the wire 11 is twisted in the first twist pitch _{P 1} second twisting pitch _{P 2} is smaller than _(P 2 _<P 1), the second section 152, and it has a length corresponding to a half of the second twisting pitch P _2. Further, in the third section 153, and the wire 11 is twisted in a second twist pitch _P less than ₂ the third twist pitch _{P 3 (P} 3 _<P 2), the third section 153, and it has a length corresponding to a half of the third twisting pitch P _3. Is not particularly limited, one example, the first twist pitch _{P 1} is 50.0 mm, the second twist pitch _{P 2} is 25.0 mm, a third twist pitch _{P 3} is 12.5mm is there. Note that the relationship between the _first to third twist pitches P _{1 to} P ₃ may not be an integral multiple.

  The first twist pattern 15 is configured by repeating a cycle 155 including the first to third sections 151 to 153. Specifically, in the present embodiment, the respective cycles 155 are arranged in the order of a first section 151, a second section 152, a third section 153, and a second section 152. . Further, in the first twist pattern 15, the left end of the cycle 155 in the drawing (the left end of the first section 151) is the left end of the first twist pattern 15 in the drawing (hereinafter, simply referred to as a "start point"). Match.

  The number of periods constituting the twist pattern is not particularly limited to the above. Moreover, as long as the periodicity of the change of the twist pitch is maintained in the twist pattern, the twist pattern may include a part of the cycle at its end. For example, in the first twist pattern 15 shown in FIG. 2A, half of the first section 151 is included in the right end in the figure as a part of the cycle.

Furthermore, the number of sections constituting the cycle and the types of sections are not particularly limited to the above. In the above example, the first to third sections 151 to 153 each have a length corresponding to half of the _first to third twist pitches P _{1 to} P ₃ , but the invention is not particularly limited to this. Not done. For example, the first to third sections 151 to 153 may each have a length corresponding to one of the _first to third twist pitches P _{1 to} P ₃ .

  Further, as shown in FIG. 3, the twist pattern may not have the periodicity as described above. FIG. 3 is a diagram showing a first modified example of the twisted pair cable in the present embodiment, and is a side view showing a state where a jacket is removed from the twisted pair cable.

Specifically, as shown in FIG. 3, the pair of electric wires 11 may have a twist pattern 15 ′ in which the twist pitches P _{1 to} P _{3 of the} electric wires 11 change randomly. In the twist pattern 15 ′, from the left end to the right end in the drawing, a first section 151, a third section 153, a second section 152, a first section 151, a second section 152,... , A first section 151, a third section 153, and a second section 152, and the first to third sections 151 to 153 are randomly arranged. Note that the arrangement of the twist pitch in the twist pattern is not particularly limited to the example shown in FIG. 3 as long as the wires are twisted so that the twist pitch changes randomly.

  As shown in FIGS. 1A and 1B, the jacket 20 has a solid cylindrical shape. The electric wires 11 are buried inside the jacket 20 with the pair of electric wires 11 twisted. The jacket 20 is made of an insulating material having electrical insulation such as a resin material. Although not particularly limited, polyvinyl chloride (PVC) can be exemplified as an example of the resin material forming the jacket 20.

Particularly, in the present embodiment, the first twist pattern 15 in which the twist pitches P _{1 to} P ₃ periodically change is stably maintained by embedding the electric wire 11 in the jacket 20 in a twisted state. be able to.

  The jacket 20 has a mark 21 indicating a specific position of the twist pattern 15 as shown in FIGS. 1A and 2B. In the present embodiment, the mark 21 is formed by printing or the like on the outer peripheral surface of the jacket 20 so as to correspond to the end of the cycle 155 in the twist pattern 15, and indicates the cycle 155 in the twist pattern 15. This mark 21 enables the period 155 of the electric wire 11 in the jacket 20 to be grasped from the outside. Note that, as long as the mark 21 indicates a specific position of the twist pattern 15, the position of the mark 21 on the outer peripheral surface of the jacket 20 is not particularly limited to the position illustrated in FIG. The mark 21 in the present embodiment corresponds to an example of the sign in the present invention.

  The sign indicating a specific position of the twist pattern 15 is not particularly limited to the mark 21 described above. FIG. 4 is a diagram illustrating a second modification of the twisted pair cable according to the present embodiment. For example, as shown in FIG. 4, a specific position of the twist pattern 15 may be indicated by forming a colored portion 22 by partially coloring the outer periphery of the jacket 20 instead of the mark 21. The coloring section 22 in the present embodiment corresponds to an example of the sign in the present invention. Alternatively, although not specifically shown, a convex portion or a concave portion may be formed on the jacket 20 as a marker indicating a specific position of the twist pattern 15.

  Hereinafter, the effect of reducing the crosstalk by the twisted pair cable 10A in the present embodiment will be described with reference to FIGS. 5 (a) to 5 (c).

  FIG. 5A is a graph showing the crosstalk characteristic of the twisted pair cable in the present embodiment, FIG. 5B is a graph showing the crosstalk characteristic of the twisted pair cable in Comparative Example 1, and FIG. 7 is a graph showing crosstalk characteristics of a twisted pair cable in Comparative Example 2.

  5 (a) to 5 (c), when two twisted pair cables are arranged and a signal is input to one twisted pair cable (Aggressor side), the other twisted pair cable (Victim side) is used. The near-end crosstalk of the twisted pair cable is indicated by a solid line, and the far-end crosstalk is indicated by a chain line. 5A to 5C, the twisted pair cable on the aggressor side is a twisted pair cable having a constant twist pitch over the entire length, and the twist pitch is 12.5 mm.

  The twisted pair cable on the victim side in FIG. 5A is a twisted pair cable having a twist pattern 15 in which the twist pitch changes periodically as shown in FIG. 2A. On the other hand, the twisted pair cable on the victim side in Comparative Example 1 in FIG. 5B is a twisted pair cable having a constant twist pitch over the entire length, similarly to the twisted pair cable on the aggressor side, and the twist pitch is 12 0.5 mm.

  As shown in FIGS. 5A and 5B, the twisted pair cable 10A of the present embodiment reduces both the near-end crosstalk and the far-end crosstalk as compared with the twisted pair cable of Comparative Example 1. ing. This is because the twist pitch of the twisted pair cable of Comparative Example 1 is the same as the twist pitch of the twisted pair cable on the aggressor side over its entire length, whereas the twist pitch of the twisted pair cable 10A of the present embodiment is The reason for this is that the twist pitch of the twisted pair cable is largely different, and the interference is weakened as a whole.

  Incidentally, the twisted pair cable on the victim side in Comparative Example 2 in FIG. 5C is a twisted pair cable having a constant twist pitch over the entire length, but is different from the twist pitch of the twisted pair cable on the aggressor side. Is 25.0 mm. As shown in FIGS. 5A and 5C, in the twisted pair cable of Comparative Example 2, both the near-end crosstalk and the far-end crosstalk are reduced as compared with the twisted pair cable 10A of the present embodiment. ing. This is because the twist pitch of the twisted pair cable of Comparative Example 2 is different from the twist pitch of the twisted pair cable on the aggressor side over the entire length thereof, whereas the twist pitch of the twisted pair cable 10A of the present embodiment is different on the aggressor side. This is because the pitch locally matches the twist pitch of the twisted pair cable.

  As described above, the twisted pair cable 10A of the present embodiment is inferior to the twisted pair cable of Comparative Example 2 in terms of crosstalk. However, the twisted pair cable 10A of the present embodiment is superior to the twisted pair cable of the comparative example 2 in comparison with the comparative example 2 in that the number of types of twisted pair cables can be reduced as follows.

  That is, when a communication cable (described later) is configured using the configuration of Comparative Example 2 (a configuration in which the twist pitch of the twisted pair cable is different), the number of twist pitches corresponding to the number of twisted pair cables configuring the communication cable is used. It is necessary to prepare variations. On the other hand, in the twisted pair cable 10A of this embodiment, a twisted pair cable having a plurality of types of twist patterns can be manufactured only by changing the cutting position when cutting out individual twisted pair cables from a long twisted pair cable. Therefore, in the twisted pair cable according to the present embodiment, the number of types of twisted pair cables for manufacturing a communication cable can be significantly reduced as compared with the twisted pair cable of Comparative Example 2.

  Hereinafter, the configuration of the communication cable 1 using the twisted pair cable 10A in the present embodiment will be described with reference to FIGS.

  FIG. 6 is a cross-sectional view illustrating a communication cable according to the present embodiment, and FIG. 7 is a diagram illustrating a twist pattern of the first to fourth twisted pair cables according to the present embodiment.

  The communication cable 1 in the present embodiment is, for example, a communication cable used for an in-vehicle LAN, and is used by being connected to devices such as an electronic control unit (ECU) and auxiliary devices mounted on the vehicle. The use of the communication cable 1 is not particularly limited to a vehicle. As shown in FIG. 6, the communication cable 1 includes four twisted pair cables 10A to 10D, a shield layer 30, and a sheath 40. The first to fourth twisted pair cables 10A to 10D respectively function as differential transmission lines for transmitting high-frequency differential signals. Note that the number of twisted pair cables included in the communication cable 1 is not particularly limited as long as it is plural.

  The first twisted pair cable 10A is the above-described twisted pair cable 10A described with reference to FIGS. 1 (a) and 2 (b).

  The second twisted pair cable 10B includes a pair of electric wires 11 and a jacket 20, similarly to the first twisted pair cable 10A described above, but the twist pattern 16 of the electric wires 11 is different from that of the first twisted pair cable 10A. Are different. Specifically, as shown in FIG. 7, the second twist pattern 16 of the second twisted pair cable 10B is shifted from the first twist pattern 15 by １ ／ period, and The starting point of the twist pattern 16 coincides with the center of the third section 153 in the cycle 155.

  The third twisted pair cable 10C also includes a pair of electric wires 11 and a jacket 20, similarly to the above-described first twisted pair cable 10A, but the twist pattern 17 of the electric wires 11 is the first twisted pair cable. 10A. Specifically, as shown in FIG. 7, the third twist pattern 17 of the third twisted pair cable 10C is shifted from the first twist pattern 15 by 2/4 cycle, and The starting point of the twist pattern 17 coincides with the second section 152 on the left side in the cycle 155.

  Further, the fourth twisted pair cable 10D also includes a pair of electric wires 11 and a jacket 20, similarly to the above-described first twisted pair cable 10A, but the twist pattern 18 of the electric wires 11 is the first twisted pair cable. 10A. Specifically, as shown in FIG. 7, the fourth twist pattern 18 of the fourth twisted pair cable 10D is shifted from the first twist pattern 15 by 3/4 cycle, and the fourth twist pattern The starting point of the pattern 18 coincides with the center of the first section 151 in the cycle 155.

  As shown in FIG. 6, the first to fourth twisted pair cables 10A to 10D are bundled together. In the present embodiment, since the mark 21 is attached to each of the twisted pair cables 10A to 10D, by bundling the twisted pair cables 10A to 10D while confirming that all the marks 21 are shifted from each other in the axial direction, A configuration in which the twist patterns 15 to 18 are different from each other can be easily formed without having the same twist pattern. In addition, as long as the twist patterns of all the twisted pair cables are shifted from each other, the shift amount is not particularly limited to the above.

  The shield layer 30 covers the outer circumference of the twisted pair cables 10A to 10D bundled together. The shield layer 30 is formed of a metal braid formed by braiding a thin metal wire. A drain wire 35 is joined to the shield layer 30, and the drain wire 35 is electrically connected to the ground of the device when the communication cable 1 is connected to the device. The shield layer 30 may be formed by winding a metal foil tape around the outer circumference of the twisted pair cables 10A to 10D instead of the metal braid. Although not particularly shown, the outer circumferences of the first to fourth twisted pair cables 10A to 10D may be covered with a presser winding tape, and the shield layer 30 may cover the outer circumferences of the presser winding tapes.

  The sheath 40 covers the outer periphery of the shield layer 30. The sheath 40 is made of an electrically insulating material such as a resin material. Although not particularly limited, polyvinyl chloride (PVC) or the like can be exemplified as an example of the resin material forming the sheath 40.

As described above, in the present embodiment, bundled twisted pair cables 10A~10D has a plurality of kinds of twisting pitch _P 1 to P _3, twist pattern 15-18 is a twisted pair cable 10A~10D as different from each other Have been. This makes it possible to make the twist pitch different in most of the adjacent twisted pair cables 10A to 10D, and to reduce the interference between the twisted pair cables 10A to 10D as a whole. Therefore, in the present embodiment, crosstalk can be reduced without using a cross inclusion or an individual shield layer.

  The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the example shown in FIG. 6, all the twisted pair cables constituting the communication cable 1 are constituted by the twisted pair cables 10A to 10D having plural kinds of twist pitches, but the present invention is not particularly limited to this. For example, the communication cable 1 is configured using a twisted pair cable having the same twist pitch over the entire length as in Comparative Example 1 or Comparative Example 2 instead of a part of twisted pair cables having a plurality of types of twist pitches. You may. In this case, the twist pitch of the twisted pair cable having a plurality of twist pitches does not have to be an integral multiple of the twist pitch of the twisted pair cable having a single twist pitch.

DESCRIPTION OF SYMBOLS 1 ... Communication cable 10A-10D ... Twisted pair cable 11 ... Electric wire 12 ... Conductor 13 ... Coating layer 15 ... 1st twist pattern 151-153 ... 1st-3rd section 155 ... Cycle 16-18 ... 2nd-4th Twist pattern 20 ... Jacket 21 ... Mark 22 ... Colored portion 30 ... Shield layer 35 ... Drain wire 40 ... Sheath

Claims (7)

A twisted pair cable comprising a pair of mutually twisted electric wires,
The electric wire is a twisted pair cable having a plurality of types of twist pitches. The twisted pair cable according to claim 1,
A twisted pair cable in which the electric wires are mutually twisted such that the twist pitch changes periodically. The twisted pair cable according to claim 1,
A twisted pair cable in which the electric wires are mutually twisted such that the twist pitch changes randomly. It is a twisted pair cable according to any one of claims 1 to 3,
The twisted pair cable has electrical insulation properties and includes a jacket in which the electric wires are embedded. The twisted pair cable according to claim 4,
The twisted pair cable, wherein the jacket has a sign indicating a specific position of a twist pattern along an axial direction of the twisted pair cable. A communication cable comprising a plurality of twisted pair cables according to any one of claims 1 to 5,
A communication cable in which a plurality of the twisted pair cables are bundled with each other, and twist patterns along the axial direction of the twisted pair cables are different from each other. A communication cable comprising a plurality of twisted pair cables according to claim 5,
A communication cable, wherein the plurality of twisted pair cables are bundled such that the positions of the markers are shifted from each other in the axial direction.

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