JP6774461B2 - Multi-core communication cable - Google Patents

Description

The present invention relates to a multi-core high-speed signal transmission cable having a plurality of coaxial electric wires. More specifically, the present invention can suitably transmit a high-speed digital signal and can easily identify the coaxial electric wire at the time of wiring a connector. Regarding multi-core communication cables for transmission.

In recent years, communication cables typified by USB3.1 and the like tend to be required to have a smaller diameter and flexibility because they are frequently used for handling such as insertion and removal as the frequency of use increases. As an improvement in the diameter reduction and flexibility required for a communication cable, for example, in Patent Document 1, a high-speed digital signal of 10 Gbps or more can be suitably transmitted, and multi-core twisted or bent. Even in this case, we are proposing a high-speed signal transmission cable in which the signal transmission speed is constant, the characteristics are unlikely to deteriorate, and the variation in the electrical length of each cable is small. This technology is a high-speed signal transmission cable including a coaxial line assembly, a shield layer provided on the outer periphery of the coaxial line assembly, and a sheath provided on the outermost layer, and the coaxial line is an internal conductor. It has a hollow core body and an outer conductor formed by vertically attaching a metal foil or a plastic tape provided with a metal layer to the outer periphery of the hollow core body.

Further, Patent Document 2 proposes a technique for providing a multi-core cable capable of suppressing crosstalk between coaxial electric wire pairs. In this technique, two or more pairs of coaxial wires are included in which two coaxial wires are in contact with each other and arranged in parallel, and each coaxial wire is composed of a central conductor, an insulator, an outer conductor, and a jacket, respectively. There is. The outer conductor has an inner layer portion formed by horizontally winding a thin metal wire and an outer layer portion formed by horizontally winding a metal resin tape around the inner layer portion, and the thin metal wire of the inner layer portion. The winding direction of the metal resin tape is opposite to the winding direction of the metal resin tape in the outer layer, and the angle of the winding direction of the metal resin tape with respect to the winding direction of the thin metal wire is 30 degrees or more and 90 degrees or less, and a plurality of coaxial cables are used. By including two or more pairs of coaxial wires in which two coaxial wires are in contact with each other and arranged in parallel, the crosstalk between the pairs of coaxial wires is set to -40 dB or less.

In such a conventional coaxial line collective cable (multi-core communication cable), since a plurality of coaxial electric wires are assembled and used, the hue of the tape winding layer is changed in order to identify each coaxial electric wire. However, increasing the number of colors of the tape according to the number of coaxial electric wires has problems in terms of cost and management. In response to such a problem, Patent Document 3 proposes a tape-wound insulated wire for increasing the number of colored tape winding layers by color without increasing the number of colors of the colored tape used for the winding tape. This technology is a tape-wound insulated wire provided with a tape-wound layer in which an insulating plastic tape is layered on the outer circumference, and the tape-wound layer is formed by two thin tapes, an inner-wound tape and an outer-wound tape. However, the hue of the tape winding layer is set by combining the hues of the inner winding tape and the outer winding tape.

WO2013 / 069755 Japanese Unexamined Patent Publication No. 2016-207658 JP-A-2002-216547

In recent years, the number of multi-core communication cables composed of a large number of coaxial electric wires has increased so that high-speed digital signals can be suitably transmitted. Therefore, it is necessary to connect or wire to a connector or the like for each role of each of these coaxial electric wires, but if it is difficult to identify them, the connection work becomes complicated and a mistake may occur. In the tape-wound insulated wire of Patent Document 3 described above, a technique for setting the hue of the tape-wound layer by combining the hues of two thin tapes, an inner-wound tape and an outer-wound tape, has been proposed. There is a drawback that the material cost and man-hours increase due to the use of two layers.

The present invention has been made to solve the above problems, and an object thereof is for high-speed signal transmission in which a high-speed digital signal can be suitably transmitted and a coaxial electric wire can be easily identified at the time of connector wiring. Is to provide a multi-core communication cable.

The multi-core communication cable according to the present invention is a multi-core communication cable including two or more sets of coaxial electric wires composed of two coaxial electric wires, and the two or more sets of coaxial electric wires are covered with a sheath. The coaxial electric wire has a central conductor, an insulator, an outer conductor, and an outer body in that order, and the outer body is formed by horizontally winding a colored tape, and a spiral shape appears on the surface of the coaxial electric wire. It is characterized by being identified by color and / or width.

According to the present invention, since the outer cover is formed by horizontally winding a colored tape, the color, wrap, and winding pitch of the colored tape are combined on the surface of the coaxial electric wire to express various differences in distinctiveness. Can be done. As a result, when connecting or wiring to a connector or the like for each role of each coaxial electric wire, identification becomes easy and connection / wiring work can be performed easily and accurately, so that mistakes can be eliminated. it can.

In the multi-core communication cable according to the present invention, the spiral color and / or width is configured by combining any one or more selected from the color, wrap, and winding pitch of the colored tape. According to the present invention, these elements can be combined to represent various distinctive differences.

In the multi-core communication cable according to the present invention, the colored tape is a resin tape with a fusion layer, and the resin tape with a fusion layer is wrapped around the resin tape.

According to the present invention, since the resin tape with the cohesive layer is used as the colored tape, by providing the cohesive layer on the outer conductor side, a spiral color and / or width represented by horizontally winding the colored tape can be obtained. It can be fixed without being disturbed. Further, since the wrap is wound, the line width or shading of the overlapping portion and the non-overlapping portion can be arbitrarily set by adjusting the degree of wrapping, and the difference in distinctiveness can be expressed. Further, since the metal thin wire and the resin tape are adhered to each other via the fusion layer, the fusion layer is fused only to the surface layer of the metal thin wire, and the flexibility based on the displacement movement of the bulk metal fine wire is increased. Can be caused. In addition, it is possible to prevent the thin metal wire from coming apart during the terminal strip, the workability is good, and there is no risk of a short circuit.

In the multi-core communication cable according to the present invention, a metal resin tape wound horizontally between the colored tape and the outer conductor and directly below the colored tape in the direction opposite to the horizontal winding direction of the colored tape. It is provided.

According to the present invention, since the metal resin tape that does not transmit light is provided on the core material side, the color of the colored tape can be made clear. Further, since the metal resin tape and the colored tape are wound in the opposite directions, the line width appearing on the colored tape can be easily understood.

In the multi-core communication cable according to the present invention, the thickness of the colored tape is in the range of 2 to 10 μm. According to the present invention, since the outer cover can be formed of a thin colored tape, it is possible to make identification without increasing the outer diameter of the entire coaxial electric wire.

In the multi-core communication cable according to the present invention, the colored tape is horizontally wound with less than 1/2 wrap. According to the present invention, since it is wound horizontally with less than 1/2 wrap, it is possible to prevent the thickness from becoming thick.

In the multi-core communication cable according to the present invention, the outer diameter of the coaxial electric wire is in the range of 0.7 to 0.9 mm. According to the present invention, it is possible to provide a multi-core communication cable including a small-diameter coaxial electric wire that can be easily identified.

In the multi-core communication cable according to the present invention, the outer sheath has one or more presser-wrapping tapes, a shield layer, and a resin extruded layer in this order from the inside to the outside.

According to the present invention, it is possible to provide a multi-core communication cable for high-speed signal transmission, which can suitably transmit a high-speed digital signal and can easily identify a coaxial electric wire at the time of connector wiring.

It is sectional drawing which shows an example of the multi-core communication cable which concerns on this invention. It is a perspective block diagram which shows the form of the coaxial electric wire which constitutes the multi-core communication cable which concerns on this invention. It is a perspective block diagram which shows the form of the coaxial electric wire which provided the metal resin tape between a metal thin wire and an outer body. It is explanatory drawing which shows the example which changed the degree of wrap.

An embodiment of the multi-core communication cable according to the present invention will be described with reference to the drawings. It should be noted that the present invention includes the invention of the same technical idea as the embodiments described below and the embodiments described in the drawings, and the technical scope of the present invention is limited to the description of the embodiments and the drawings. Not a thing.

[Multi-core communication cable]
As shown in FIGS. 1 to 4, the multi-core communication cable 10 according to the present invention is a cable 10 including two or more coaxial electric wire sets 2 composed of two coaxial electric wires 1 and 1. The coaxial electric wire 1 has a central conductor 11, an insulator 12, an outer conductor 13, and an outer cover 14 in that order. The outer cover 14 is composed of a colored tape wound horizontally, and is identified by a spiral color and / or width appearing on the surface of the coaxial electric wire 1, and the spiral color and / or width is the color and / or width of the colored tape. And any one or more selected from the winding pitch are combined.

Since the outer cover 14 of the multi-core communication cable 10 is formed by horizontally winding a colored tape, the color, wrap, and winding pitch of the colored tape are combined on the surface of the coaxial electric wire 1 to provide various distinctiveness. Can show the difference. As a result, when connecting or wiring to a connector or the like for each role of each coaxial electric wire 1, identification becomes easy and connection / wiring work can be performed easily and accurately, so that no mistake is made. Can be done.

Hereinafter, each component will be described in detail.

<Coaxial wire>
As shown in FIGS. 1 to 3, the coaxial electric wire 1 includes a central conductor 11, an insulator 12 continuous on the outer periphery of the central conductor 11 in the longitudinal direction Y, and an outer conductor 13 provided on the outer periphery of the insulator 12. And an outer cover 14 provided on the outer periphery of the outer conductor 13.

(Center conductor)
The central conductor 11 is composed of one strand extending in the longitudinal direction Y of the coaxial electric wire 1, or is composed of a plurality of strands twisted together. The type of the strand is not particularly limited as long as it is a good conductive metal, but it is a good conductive metal conductor such as a copper wire, a copper alloy wire, an aluminum wire, an aluminum alloy wire, or a copper-aluminum composite wire, or a surface thereof. A plating layer is preferably applied to the aluminum. From the viewpoint of high frequency, copper wire and copper alloy wire are particularly preferable. As the plating layer, a solder plating layer, a tin plating layer, a gold plating layer, a silver plating layer, a nickel plating layer and the like are preferable. The cross-sectional shape of the wire is not particularly limited, but the cross-sectional shape may be a circular or substantially circular wire rod, or may be a square shape.

The cross-sectional shape of the central conductor 11 is also not particularly limited, but may be circular (including an elliptical shape), rectangular, or the like. The outer diameter of the central conductor 11 is preferably as large as possible so that the electrical resistance (AC resistance, conductor resistance) becomes small, and for example, about 0.09 to 0.4 mm can be mentioned. An insulating film (not shown) may be provided on the surface of the center conductor 11 if necessary. The type and thickness of the insulating film are not particularly limited, but for example, those that decompose well during soldering are preferable, and thermosetting polyurethane films and the like can be preferably mentioned.

(Insulator)
The insulator 12 is a low dielectric constant insulating layer provided continuously on the outer periphery of the central conductor 11 in the longitudinal direction Y. The material of the insulator 12 is not particularly limited, but for example, a fluororesin having a low dielectric constant such as PFA, ETFE, or FEP is preferable, and good high-frequency transmission characteristics can be exhibited. The material of the insulator 12 may contain a colorant. The method for forming the insulator 12 is not particularly limited, and examples thereof include extrusion and coating. The structural form of the insulator 12 may be a solid structure, a hollow structure, or a foam structure. Since the hollow structure and the foamed structure have voids inside the structure, the dielectric constant can be further reduced. The thickness of the insulator 12 is also not particularly limited, but is preferably in the range of about 0.2 to 0.5 mm.

(Outer conductor)
The outer conductor 13 is provided on the outer periphery of the insulator 12. The outer conductor 13 is provided separately from the shield layer 6 that covers the entire surface, which will be described later. The outer conductor 13 is formed by horizontally winding a thin metal wire 13a. The thickness of the outer conductor 13 varies depending on the wire diameter and the number of twists of the thin metal wire 13a used, and is not particularly limited.

The thin metal wire 13a is not particularly limited as long as it is a well-conductive metal thin wire provided on the outer periphery of the dielectric layer (insulator 12) as an outer conductor of the coaxial electric wire. For example, various fine metal wires typified by tin-plated copper wire and the like can be preferably used. The diameter of the thin metal wire 13a is also not particularly limited, and examples thereof include those in the range of about 0.04 to 0.1 mm. The number of thin metal wires 13a is arbitrarily selected depending on the outer diameter of the insulator 12 and the planned outer diameter of the coaxial electric wire 1, but 48 on the insulator 12 having a diameter of 0.05 mm as in the embodiment described later. The thin metal wire 13a of the book can be horizontally wound to form the outer conductor 13.

The winding pitch P1 when the thin metal wire 13a is wound horizontally differs depending on the outer diameter of the insulator 12. For example, when the outer diameter of the insulator 12 is 0.78 m as in the embodiment described later, the pitch P1 is set. It is preferably about 14 mm. Since the horizontal winding pitch P1 is used, even if the thin metal wire 13a that exhibits flexibility at the time of bending shifts to some extent, the electrical conduction can be more stabilized and stable shielding characteristics can be ensured.

(Metal resin tape)
Although the metal resin tape 13b is not an essential configuration, it is preferable that the metal resin tape 13b is provided between the thin metal wire 13a and the outer cover 14 described later, as shown in FIG. When the metal resin tape 13b is provided, the "outer conductor 13" is formed together with the thin metal wire 13a. When the metal resin tape 13b is provided, it is wound horizontally with the metal layer surface on the metal thin wire side.

The metal resin tape 13b is provided between the colored tape 14 and the outer conductor 13, which will be described later, directly below the colored tape 14. In particular, the colored tape 14 is provided by being horizontally wound in the direction opposite to the horizontal winding direction. Since the metal resin tape 13b easily reflects or absorbs light in the metal layer, it is difficult for light to pass through to the core material side. Therefore, the color of the colored tape 14 can be made clearer. Further, by winding the metal resin tape 13b and the colored tape 14 in opposite directions, the line width appearing in the colored tape 14 can be made easier to understand.

Further, by providing the metal resin tape 13b, the metal thin wire 13a and the metal layer of the metal resin tape 13b are electrically conductive, so that even if the metal thin wire 13a exhibiting flexibility at the time of bending is slightly displaced. By arranging the metal resin tape 13b restrained by the resin tape 14a described later on the thin metal wire 13a, stable shielding characteristics can be ensured.

Such a metal resin tape 13b has a metal layer provided on a resin base material. The resin base material is not particularly limited, but a polyester film such as polyethylene terephthalate or polyethylene naphthalate can be preferably used. The thickness of the resin base material is arbitrarily selected within the range of, for example, about 2 to 20 μm. As the metal layer, a copper layer, an aluminum layer and the like can be preferably mentioned. As the metal layer, a metal layer formed on a resin base material by vapor deposition or plating, or a metal foil bonded via an adhesive layer (for example, a polyester-based thermoplastic adhesive resin or the like) can be preferably mentioned. The thickness of the metal layer is not particularly limited and varies depending on the forming means, but the one formed by vapor deposition or plating can be arbitrarily selected from the range of about 2 to 8 μm, and the metal foil is bonded. Can be arbitrarily selected from the range of about 6 to 16 μm. As described above, the type, thickness, color, surface morphology, etc. of the metal layer affect the reflection and absorption of light, so the distinctiveness of the colored tape is improved in consideration of such reflection characteristics and absorption characteristics. It is preferred to choose to improve.

As shown in FIG. 3, the metal resin tape 13b is horizontally wound at a pitch P2 of 4 to 10 mm. When winding horizontally at this pitch P2, the tape width is selected so that the wrap is 1/5 to 1/2. It is preferable to arbitrarily select and use the tape width when the pitch P2 and the wrap are wound horizontally. The horizontal winding of the metal resin tape 13b is preferably wrapped and horizontally wound without leaving a gap so that the color of the colored tape 14 can be made clearer. Further, it is preferable that the metal layer side is opposed to the metal thin wire 13a so as to be in direct contact with the metal thin wire 13a. As a result, the thin metal wire 13a and the metal layer can be electrically conductive. By arranging and horizontally winding the metal resin tape 13b under the pitch P2 and the wrap so as to face each other, the metal layer can be directly contact-arranged on the thin metal wire 13a without creating a gap between the metal layers of the metal resin tape 13b. it can. As a result, even if the thin metal wire 13a, which exhibits flexibility at the time of bending, shifts to some extent, the electrical conduction can be further stabilized and stable shielding characteristics can be ensured.

The horizontal winding pitch P2 of the metal resin tape 13b is preferably in the range of 1/5 to 1/2 of the horizontal winding pitch P1 of the thin metal wire 13a. By doing so, the resin tape 13b can be wound without gaps, and the thin metal wire 13a can be pressed. The horizontal winding direction of the metal resin tape 13b may be the same as the horizontal winding direction of the thin metal wire 13a described above, or may be the opposite winding direction, but the reverse direction is preferable. The tape width is arbitrarily selected depending on the winding pitch, ease of winding, and the like, and can be, for example, about 3 to 10 mm as in the examples described later.

It is preferable that the metal resin tape 13b is adhered to the resin tape with a fusion layer described later via the fusion layer 14b. By providing the metal resin tape 13b so that the metal thin wire 13a is not directly fixed by the resin tape with a fusion layer, it is possible to secure the displacement movement of the metal thin wire 13a and to prevent the metal resin tape 13b from being directly fixed at the time of terminal stripping. The thin metal wire 13a located below does not come apart.

(Outer body)
The outer cover 14 is provided on the outer periphery of the outer conductor 13. The outer cover 14 is formed by horizontally winding a colored tape (the colored tape also uses reference numeral 14 in the present application), and the individual coaxial electric wires 1 are arranged according to the spiral color and / or width appearing on the surface of the coaxial electric wire 1. Is identified according to its role and the like. Specifically, since the colored tape 14 is wound horizontally, various distinctive differences can be expressed on the surface of the coaxial electric wire 1 by combining the color, wrap, and winding pitch of the colored tape 14. As a result, when connecting or wiring to a connector or the like for each role of each coaxial electric wire 1, identification becomes easy and connection / wiring work can be performed easily and accurately, so that no mistake is made. Can be done.

The colored tape 14 is preferably a resin tape with a cohesive layer, and is horizontally wound with the side of the cohesive layer 14b of the resin tape with a cohesive layer as the outer conductor side. By providing the colored tape 14 in this way, the colored tape 14 can be fixed without disturbing the spiral color and / or width L represented by the horizontal winding. Further, since the wrap is wound, as shown in the example in which the degree of wrap is changed in FIG. 4, by adjusting the degree of wrap, the overlapped portion 14'(length L1) and the non-overlapping portion 14'( The line width or shading with the length L2) can be arbitrarily set, and the difference in distinctiveness can be expressed.

Specifically, as shown in FIG. 4A, the overlapping portion 14'is shortened (length L1) and the non-overlapping portion 14'is lengthened (length L2), and FIG. 4B As shown in the above, the width of the colored line appearing on the surface of the coaxial wire 1 is different from the case where the overlapping portion 14'is lengthened (length L1) and the non-overlapping portion 14' is shortened (length L2). Since the shades are different, even when the colored tape 14 of the same color is used, a plurality of identifiable coaxial electric wires 1 can be obtained. Further, by using the metal resin tape 13b described later in combination, the reflection and absorption thereof can be utilized to obtain a plurality of coaxial electric wires 1 having further identification variations even when the colored tape 14 of the same color is used. be able to. In order to enhance the distinctiveness, L1 ≦ L is preferable in the case of FIG. 4 (A), and L / 3 ≦ L2 is preferable in the case of FIG. 4 (B). When the colored tape 14 is wound in consideration of productivity, the case of L1 ≦ L / 2 is preferable in FIG. 4A.

Examples of the material of the resin tape 14a constituting the colored tape 14 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyamide (PA), polyimide (PI), polyphenylene sulfide (PPS), and ethylene-tetrafluoride. Ethylene copolymer (ETFE), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP), fluorinated resin copolymer (perfluoroalkoxy alkane resin: PFA), polyetheretherketone (PEEK), etc. be able to. In terms of hardness and elongation, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and the like are preferable. These resin tapes are usually single-layered, but may have two or more layers depending on the purpose. The thickness of the resin tape 14a is not particularly limited as long as it is thick enough to secure the required dielectric strength, but it can be about 0.004 mm as in the examples described later.

The fusion layer 14b constituting the colored tape 14 is provided on one side of the resin tape 14a. The material of the fused layer 14b is a resin composition mainly composed of a thermoplastic resin, and preferably has a property of being able to adhere by causing a crosslinking reaction at a specific temperature or higher. Due to these properties, the colored tape 14 is provided by horizontally winding the fused layer 14b on the outer conductor side, and at that time or after that, it is heated to a specific temperature or higher to cause a cross-linking reaction and adhere to the outer conductor 13. Let me. By doing so, the colored tape 14 adheres and fixes the metal resin tape 13b via the fusion layer 14b when the metal resin tape 13b is optionally provided under the metal resin tape 13b, so that the position of the metal layer is fixed. It is possible to prevent the deviation. As a result, stable shielding characteristics can be maintained even when bending occurs, and it is possible to prevent the thin metal wire located under the metal resin tape 13b from being separated during the terminal strip, and processing is performed. It has good properties and there is no risk of short circuit. Further, when the colored tape 14 is wound horizontally, a winding stress is applied, but since the stress is relaxed or dispersed by heating at that time or thereafter, the rigidity due to the concentration of the winding stress can be alleviated, and from the viewpoint of flexibility. It will be preferable.

Examples of the material of the cohesive layer 14b constituting the colored tape 14 include thermosetting resins such as polyurethane resin, polyester resin, and polyesterimide resin. Of these, polyurethane resin and polyester resin are preferable. The resin composition for forming the fusion layer forming the fusion layer 14b contains a cross-linking agent and a solvent. In addition, various additives are included as needed. The cross-linking agents, solvents and additives thereof are not particularly limited, and various cross-linking agents, solvents and additives according to the types of polyurethane resin, polyester resin, polyesterimide resin and the like and their required characteristics are used as necessary. .. The thickness of the fused layer 14b is also not particularly limited, but can be, for example, about 0.001 mm.

It should be noted that, at the time of horizontal winding, by applying a temperature lower than the specific temperature at which the cross-linking reaction is carried out, it is possible to make a temporary adhesive state and perform horizontal winding. By doing so, it is possible to prevent the horizontally wound resin tape 14a from being unwound. The temperature at which such a temporary bonding state occurs is preferably a temperature lower than the temperature at which the crosslinking reaction of the fused layer 14b occurs. For example, regarding "a cross-linking reaction occurs at a specific temperature or higher and adhesion", when a polyester-based thermosetting resin is used as the resin composition for forming a fusion layer, it is cured at, for example, about 160 to 200 ° C. It can be temporarily bonded on the outer conductor 13, but as a temporary bonding state, it can be temporarily cured at about 80 to 130 ° C., which is lower than the temperature, and temporarily bonded. Further, among other thermosetting resins, those having a "specific temperature" of about 90 to 150 ° C. (for example, epoxy-based thermosetting resin, manufactured by TOMOEGAWA, Elephant CS) are temporarily adhered at about 50 to 70 ° C. Can be. When the colored tape 14 is wound horizontally, it is possible to prevent winding misalignment due to such an operation. The temporary bonding state and the bonding state can be roughly evaluated by the heating weight loss curve measured using a hot balance. For example, the curing behavior of a resin can be analyzed by considering the heating weight lapse rate as hardness. By such evaluation, the "temporary bonding state temperature" and the "specific bonding temperature" can be arbitrarily designed, and the temperature difference is set to be large, for example, 80 ° C to 120 ° C, or small, such as 0 ° C to 50 ° C. It can be a thing.

The resin tape 14a is usually colored, but the fusion layer 14b may be colored. Coloring can be provided by incorporating a colorant in the resin tape 14a or by applying or printing the colorant on the resin tape 14a. By coloring the resin tape 14a, different colors can be given to the coaxial electric wire 1 by the colored tape 14, and the coaxial electric wires 1 having individual roles can be identified by the colors. As the colorant, those generally used as a resin tape colorant can be used.

The spiral color and / or width appearing on the surface of the coaxial electric wire 1 is configured by combining any one or more selected from the color, wrap, and winding pitch of the colored tape 14 described above. By combining these elements, it is possible to express the difference in the distinctiveness of each coaxial electric wire 1 in the multi-core communication cable 10 having a large number of coaxial electric wires 1. Further, the degree of wrapping of the colored tape 14 is not particularly limited, but it is preferable that the colored tape 14 is horizontally wound with less than 1/2 wrap. By doing so, it is possible to prevent the obtained outer body 14 from becoming thicker.

The horizontal winding pitch P3 when the colored tape 14 is wound horizontally is not particularly limited, but when the metal resin tape 13b is arbitrarily provided, the horizontal winding pitch P2 of the metal resin tape 13b shall be the same as or about the same. Is preferable. By setting the wrap and the horizontal winding pitch P3 of the colored tape 14 and the horizontal winding pitch P2 of the arbitrarily provided metal resin tape 13b as described above, the difference in the distinctiveness of each coaxial electric wire 1 can be expressed. At the same time, the resin tape 14a can be wound horizontally at a pitch P3 in which the metal layer arranged under the resin tape 14a is not easily displaced after ensuring the overlap of the resin tape 14a fixed by the fusion layer 14b. In particular, in the latter case, even when bending occurs and the thin metal wire 13a is slightly displaced, stable contact between the metal resin tape 13b covering the thin metal wire 13a and the resin tape 14a adhering on the thin metal wire 13a is maintained. It is being held. As a result, stable shield characteristics can be maintained.

When the metal resin tape 13b is arbitrarily provided, the horizontal winding direction of the colored tape may be the same as the horizontal winding direction of the metal resin tape 13b or the opposite winding direction, but the reverse direction. It is preferable to wind it in the direction.

The thickness of the colored tape 14 is not particularly limited, but is preferably in the range of 2 to 10 μm. By setting it within this range, the outer cover can be formed of the thin colored tape 14, so that the identification can be performed without increasing the outer diameter of the entire coaxial electric wire.

As shown in FIG. 2, when the metal resin tape 13b is not provided between the outer cover (colored tape) 14 and the metal thin wire 13a, the metal thin wire 13a and the resin tape 14a form a fusion layer 14b. Since they are adhered to each other, the fused layer 14b is fused only to the surface layer of the thin metal wire 13a, and flexibility based on the displacement movement of the thin metal wire in the bulk can be generated. Further, it is possible to prevent the thin metal wire 13a from coming apart during the terminal strip, the workability is good, and there is no risk of a short circuit. On the other hand, as shown in FIG. 3, when the metal resin tape 13b is provided between the outer cover (colored tape) 14 and the thin metal wire 13a, particularly directly under the colored tape, the metal layer of the metal resin tape 13b is illuminated. The color of the colored tape 14 can be made clearer because it is easily reflected or absorbed.

In this way, the coaxial electric wire 1 that can be easily identified can be configured. The outer diameter of the coaxial electric wire 1 is preferably in the range of 0.7 to 0.9 mm.

<Multi-core communication cable>
As shown in FIG. 1, the multi-core communication cable 10 is a press winding that covers and bundles the core material 3, two or more sets of coaxial electric wire sets 2 arranged on the outer periphery of the core material 3, and two or more sets of coaxial electric wire sets 2. It is composed of at least a tape 5, a shield layer 6 that covers the presser foot tape 5, and a resin extrusion sheath 7 that covers the shield layer 6. The presser winding tape 5, the shield layer 6, the resin extruded sheath 7, and the like that cover two or more sets of coaxial electric wire sets 2 may be referred to as a jacket sheath 4. The multi-core communication cable 10 includes two or more sets of coaxial electric wires 2 composed of the above-mentioned two coaxial electric wires. For example, in the example of FIG. 1, four coaxial electric wire sets 2 are included. The number of the coaxial electric wire sets 2 may be at least two or more, and the upper limit is not particularly limited, but may be about 4 to 8.

(Core material)
The core material 3 is located at the center of the multi-core communication cable 10, and can be in various forms. For example, a high-tensile tension member that functions as a winding core acts to reinforce the axial strength and flexibility of the multi-core communication cable 10. As an example, a fiber thread composed of a plurality of fibers or a fiber bundle obtained by bundling the fiber threads is preferably used. Examples of the fibers constituting the fiber bundle or fiber yarn include polyester fibers such as Tetron (registered trademark), all-aromatic polyamide fibers such as Kebra (registered trademark), and polyarylate fibers such as Vectran (registered trademark). Glass fiber and the like can be mentioned. Further, the core material 3 may be an arbitrary composite of fibers made of different materials or fiber threads having different outer diameters. The core material 3 has a concentric (perfect circular) cross section in which these fiber bundles or fiber threads are made into a collecting wire, a stranded wire, or a braided wire. In addition, "dtex" indicates a fiber yarn in terms of weight, and 1 dtex means that the length is 10000 m and the weight is 1 g.

As another example of the core material 3, the power line, the signal line, and the drain line may be arbitrarily selected and bundled. These can be arbitrarily selected according to the requirements such as the application of the multi-core communication cable 10.

(Core material holding tape)
The core material 3 is preferably covered with a core material holding tape 8. The core material presser winding tape 8 is not particularly limited as long as it can hold the core material 3 so as not to come apart, but polyester tape or the like can be preferably mentioned, for example. The thickness is not particularly limited, and is preferably in the range of 0.003 to 0.01 mm. The outer diameter of the core material 3 after being wound with the core material presser winding tape 8 is arbitrarily selected according to its role and application, and is not particularly limited. The tape width is arbitrarily selected depending on the winding pitch and the like, and is not particularly limited.

(Outer sheath)
The outer sheath 4 is composed of a presser foot tape 5, a shield layer 6, a resin extruded sheath 7, and the like. The presser foot tape 5 is provided so as to cover and bundle two or more coaxial electric wire sets 2. The presser foot tape 5 is not particularly limited as long as it can hold the plurality of coaxial electric wire sets 2 so as not to come apart, but polyester tape, paper tape and the like can be mentioned, and Japanese paper tape is particularly preferable. it can. The thickness of the presser winding tape 5 is also not particularly limited, and is preferably in the range of 0.003 to 0.01 mm. The outer diameter after being wound with the presser winding tape 5 is not particularly limited, but can be, for example, within the range of mm. The tape width is arbitrarily selected depending on the winding pitch and the like. In addition, when the signal line or the like is provided together with the coaxial electric wire set 2 as needed, the presser winding tape 5 acts to wind and hold them together.

The shield layer 6 covers the presser foot tape 5. The shield layer 6 may be a braided or horizontally wound metal thin wire similar to the metal thin wire 13a constituting the outer conductor 13, or an insulating tape with a metal layer (for example, polyethylene with a copper foil). It may be a terephthalate film or the like), or it may be a combination of both of them. In the example of FIG. 1, the thin wire braid is provided as the shield layer 6. The shield layer 6 can be provided by arbitrarily selecting a thin metal wire similar to the above-mentioned thin metal wire 13a. The thickness of the shield layer 6 varies depending on the type of braided metal wire, horizontal winding, or insulating tape with a metal layer, but it is only limited as long as it is thick enough to exhibit the shielding performance according to each. However, it is in the range of, for example, about 0.05 to 0.30 mm.

The shield layer 6 may be a single shield layer or a double or more shield layer. As for the two-layer horizontal winding shield layer, each layer may be in the same direction or in the opposite direction. By winding the shield layer horizontally with double conductors and winding them horizontally in the opposite direction, it is possible to prevent disconnection from occurring. In particular, as compared with a shield conductor formed by vertically attaching or horizontally winding a metal tape, it is less likely to break and the bending resistance can be improved.

The resin extrusion sheath 7 is provided so as to cover the shield layer 6. As with the outer body 14, the material of the resin extruded sheath 7 is not particularly limited as long as it has an insulating property. For example, various generally applied substances can be used, for example, a fluororesin such as ETFE, a vinyl chloride resin, or a polyolefin resin such as polyethylene may be used. Alternatively, it may be a polyester resin such as polyethylene terephthalate. The thickness of the resin extruded sheath 7 can be, for example, in the range of about 0.5 to 1.5 mm. By providing such a resin extruded sheath 7, the finished outer diameter of the multi-core communication cable 10 is not particularly limited.

A tape-wrapped sheath may be used instead of the extruded sheath 7. As the tape-wrapped sheath, various types used as insulating tapes for coaxial electric wires can be arbitrarily selected and used within a range satisfying necessary characteristics.

As described above, the multi-core communication cable 10 according to the present invention is a multi-core communication cable for high-speed signal transmission capable of suitably transmitting a high-speed digital signal and easily identifying a coaxial electric wire at the time of connector wiring. Can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

[Example 1]
First, the coaxial electric wire 1 having the form shown in FIGS. 2 and 4 (A) was produced. For each coaxial electric wire 1, as the central conductor 11, AWG30 (outer diameter of about 0.3 mm) obtained by twisting seven tin-plated annealed copper wires having a diameter of 0.10 mm was used. Next, a 0.24 mm thick FEP resin (manufactured by DuPont) layer was extruded and formed on the outer periphery of the central conductor 11 to have an outer diameter of 0.78 mm. Next, the outer conductor 13 was formed. The outer conductor 13 was wound with 48 tin-plated annealed copper wires (thin metal wires 13a, abbreviated as TCW) having a diameter of 0.05 mm in a left-horizontal winding at a pitch P1 of 14 mm. The outer diameter after providing the outer conductor 13 was 0.88 mm. After that, a colored PFE tape (resin tape 14a) with a fusion layer having a thickness of 0.004 mm and a width of 2 mm was used as the outer cover 14, and the outer conductor 13 was wound with the fusion layer 14b on the outer conductor side. It was wound right-handed in the opposite direction. The winding pitch P2 at that time was 4 mm, and the wound was wound with 1 / 2.2 laps. The outer diameter of each coaxial electric wire 1 was 0.89 mm. The spiral width L appearing on the surface of the colored PFE tape 14 was 2.0 mm, the length L1 of the overlapping portion 14'was 1.7 mm, and the relational expression was L1 ≦ L.

Then, as the core material 3, 280 dtex × 3 aramid fibers were used as tension members, and the tension members were covered and bundled with the presser winding tape 8. Then, four sets of coaxial electric wire sets 2 composed of the two coaxial electric wires obtained above were used, and the core material 3 was right-twisted around the outer periphery of the core material 3 at a pitch of 70 mm with the core material 3 as the axial center position. Then, it was pressed and wound with Japanese paper tape 5 having a width of 15 mm so as to cover the four sets of coaxial electric wire sets 2. Then, as the shield layer 6, 105 tin-plated annealed copper wires having a diameter of 0.10 mm were used and wound right-handed. The outer diameter after the shield layer 6 was provided was 4.2 mm. Then, as the resin extrusion sheath 7, soft PVC having a thickness of 0.4 mm was extruded to obtain a multi-core communication cable 10 having a final outer diameter of 5.0 mm. In the coaxial electric wire constituting this multi-core communication cable, the length L1 of the overlapping portion 14'was small, and the dark colored line appeared as a thick spiral.

[Example 2]
In Example 1, the winding pitch P2 of the colored PFE tape 14 was set to 4 mm, and the colored PFE tape 14 was wound with 1/4 wrap. The multi-core communication cable 10 of Example 2 was produced in the same manner as in Example 1 except for the above. The spiral width L appearing on the surface of the colored PFE tape 14 was 4.0 mm, the length L1 of the overlapping portion 14'was 1.2 mm, and the relational expression was L / 3 ≦ L2. In the coaxial electric wire constituting this multi-core communication cable, the length L2 of the non-overlapping portion 14 "occupies a large part, and the dark colored line appears as a thin spiral.

1 Coaxial wire 2 Coaxial wire assembly 3 Core material 4 Outer sheath 5 Presser winding tape 6 Shield layer 7 Resin extrusion layer 8 Core material Presser winding tape 10 Multi-core communication cable 11 Center conductor 12 Insulator 13 External conductor 13a Metal thin wire 13b Metal Resin tape 14 Outer body (colored tape)
14a Resin tape 14b Fused layer 14'Overlapping part 14 "Non-overlapping part Y Longitudinal direction P1 Horizontal winding pitch of metal thin wire P2 Horizontal winding pitch of metal resin tape P3 Horizontal winding pitch of resin tape L Spiral width appearing on the surface L1 Length of overlapping part L2 Length of non-overlapping part

Claims (6)

A multi-core communication cable including two or more sets of coaxial electric wires composed of two coaxial electric wires and covering the two or more sets of coaxial electric wires with a sheath, and the coaxial electric wires are a central conductor and an insulator. The outer conductor and the outer body are provided in that order, and the outer body is formed by horizontally winding a colored tape, and is identified by a spiral color and / or width appearing on the surface of the coaxial electric wire. A multi-core feature is provided between the colored tape and the outer conductor, directly below the colored tape, with a metal resin tape wound horizontally in the direction opposite to the horizontal winding direction of the colored tape. communication cable. The multi-core communication cable according to claim 1, wherein the spiral color and / or width is configured by combining any one or more selected from the color, wrap, and winding pitch of the colored tape. The multi-core communication cable according to claim 1 or 2, wherein the colored tape is a resin tape with a fusion layer, and the resin tape with a fusion layer is wrapped around the resin tape. The multi-core communication cable according to any one of claims 1 to 3 , wherein the thickness of the colored tape is in the range of 2 to 10 μm. The multi-core communication cable according to any one of claims 1 to 4 , wherein the colored tape is horizontally wound with a wrap of less than 1/2. The one according to any one of claims 1 to 5 , wherein the outer sheath has one or more presser-wrapping tapes, a shield layer, and a resin extruded layer in that order from the inside to the outside. Multi-core communication cable.