Communication cable

Abstract

To provide a communication cable capable of improving flexibility while maintaining return loss and near-end crosstalk attenuation even with a small diameter.SOLUTION: A communication cable 1 includes a cable core 10, a binding tape 20 laterally wrapped around the cable core 10, a shielding layer 30 covering the binding tape 20, and an outer sheath 40 covering the shielding layer 30. The cable core 10 includes a plurality of twisted pairs 8 and an interstice 9 for separating the plurality of twisted pairs 8 from each other. The width of the binding tape 20 is greater than 5 mm and less than 25 mm. The stranding pitch of the cable core 10 is greater than 40 mm and less than 100 mm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a communication cable. [Background technology]

[0002] Communication cables such as LAN (Local Area Network) cables are used to connect various devices, such as between servers, between servers and switches, between servers and personal computers, etc. In recent years, there has been a demand for communication cables that are suitable for high-speed data communication and meet the Category 6A standard.

[0003] On the other hand, many communication cables suitable for high-speed data communication have low flexibility. Cables with low flexibility are stiff and prone to rebound, which makes it difficult for workers to lay them. For this reason, various means have been proposed to increase the flexibility of communication cables. For example, Patent Document 1 describes a method for laying a communication cable with a basis weight of 90 to 110 g / m2 as a rolled cable. 2 The present inventors have proposed that the flexibility of a communication cable be improved by using a nonwoven fabric tape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-20460 Summary of the Invention [Problem to be solved by the invention]

[0005] In applications requiring high-density wiring, small-diameter communication cables with outer diameters of approximately 3.0 to 6.5 mm are often used. The inventors attempted to improve the flexibility of such small-diameter communication cables by using a nonwoven fabric tape with the above basis weight as a winding material, but found that the return loss (RL) and near-end crosstalk (NEXT) of the communication cable significantly decreased.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a communication cable that can improve flexibility while maintaining return loss and near-end crosstalk attenuation even when it has a small diameter. [Means for solving the problem]

[0007] The communication cable for solving the above problem is: a cable core including a plurality of twisted wire pairs and an interposer for spacing the plurality of twisted wire pairs from one another; a winding tape wound laterally around the cable core; a shielding layer covering the wound tape; an outer jacket covering the shielding layer; and The width of the wound tape is greater than 5 mm and less than 25 mm; The twist pitch of the cable cores is characterized by being greater than 40 mm and less than 100 mm. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a communication cable that can maintain the return loss and near-end crosstalk attenuation and improve flexibility even when it has a small diameter. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of a communication cable according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a so-called twisted pair cable for LAN use will be described in detail as a communication cable according to one embodiment of the present invention with reference to the drawings, although the present invention is not limited thereto. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In numerical ranges described in stages in this specification, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages.

[0011] (Communication cable configuration) FIG. 1 is a schematic cross-sectional view of a communication cable 1 according to an embodiment of the present invention. As shown in Figure 1, the communication cable 1 has a cable core 10, a winding tape 20 wound transversely around the cable core 10, a shielding layer 30 covering the winding tape 20, and an outer jacket 40 covering the shielding layer 30.

[0012] The cable core 10 includes multiple pairs of twisted wires 8 and interposers 9 for separating the multiple pairs of twisted wires 8 from one another. The multiple pairs of twisted wires 8 and interposers 9 are twisted together in a fixed direction at a predetermined twisting pitch. Here, the "twisting pitch" refers to the distance in the longitudinal direction of the cable core 10 required for one pair of twisted wires 8 to make one circuit when the multiple pairs of twisted wires 8 and interposers 9 are twisted together.

[0013] Each of the multiple pairs of twisted pair wires 8 has two insulated wires 6. In each twisted pair wire 8, the two insulated wires 6 are twisted together in a fixed direction at a predetermined twist pitch. Here, the "twist pitch" refers to the longitudinal distance of the twisted pair wire 8 required for one insulated wire 6 to make one full turn when two insulated wires 6 are twisted together. The number of twisted wire pairs 8 is not particularly limited as long as it is plural. In this embodiment, the number of twisted wire pairs 8 is four.

[0014] The insulated wire 6 has a conductor 2 and an insulating layer 4 that covers the conductor 2 . The conductor 2 is a conducting wire made of a conductive metal material. There are no particular limitations on the type of conductor 2. In this embodiment, the conductor 2 is a soft copper wire. The conductor 2 may be a solid wire or a twisted wire made by twisting together a plurality of wires. There are no particular limitations on the outer diameter (circular equivalent diameter) of the conductor 2, and it is selected appropriately depending on the use and type of the communication cable 1. The diameter of the conductor 2 is, for example, within a range of 0.2 to 0.5 mm. The insulating layer 4 covers the conductor 2. The material of the insulating layer 4 is not particularly limited as long as it has insulating properties. In this embodiment, the insulating layer 4 is made of polyethylene. The thickness of the insulating layer 4 is not particularly limited and can be selected appropriately. The thickness of the insulating layer 4 is, for example, within the range of 0.1 to 0.3 mm.

[0015] The spacers 9 extend in the longitudinal direction of the communication cable 1 and separate the multiple pairs of twisted wires 8 from one another. That is, the multiple pairs of twisted wires 8 are separated by the spacers 9 so that they do not come into contact with one another. The shape of the spacers 9 is not particularly limited as long as it can separate the multiple pairs of twisted wires 8 from one another. In this embodiment, the cross-sectional shape of the spacers 9 perpendicular to the longitudinal direction of the communication cable 1 is a plus sign shape. In other words, the spacers 9 are so-called cross spacers. The material of the spacers 9 is also not particularly limited as long as it can perform the above-mentioned functions. In this embodiment, the material of the spacers 9 is polyethylene. The wire inserts 9 are twisted along the length of the cable core 10 (communication cable 1). Accordingly, the multiple pairs of twisted wires 8 are also twisted along the length of the cable core 10 (communication cable 1) while being separated by the wire inserts 9.

[0016] As explained above, the cable core 10 (multiple pairs of twisted wires 8 and interposers 9) are twisted together in a fixed direction at a predetermined twist pitch. As mentioned above, the "twist pitch" refers to the distance in the longitudinal direction of the cable core 10 required for one pair of twisted wires 8 to make one circuit when multiple pairs of twisted wires 8 and interposers 9 are twisted together. Here, the twist pitch of the cable core 10 is preferably greater than 40 mm and less than 100 mm. For example, the twist pitch of the cable core 10 is within a range of 50 to 90 mm. In the communication cable 1 according to the present embodiment, when the twist pitch is 40 mm or less, the near-end crosstalk attenuation (NEXT) is likely to decrease, but when the twist pitch is greater than 40 mm, the decrease in near-end crosstalk attenuation can be suppressed. The reason why the near-end crosstalk attenuation decreases when the twist pitch is 40 mm or less is presumed to be, but not limited to, as follows: When the twist pitch is 40 mm or less, the twist pitch of the twisted wire pairs 8 is likely to change due to the influence of the twist pitch, which in turn decreases the near-end crosstalk attenuation. In contrast, when the twist pitch is greater than 40 mm, the twist pitch of the twisted wire pairs 8 is unlikely to change, and the near-end crosstalk attenuation is unlikely to decrease. Furthermore, in the communication cable 1 according to this embodiment, if the twisting pitch is 100 mm or more, the return loss (RL) is also likely to decrease, but by setting the twisting pitch to less than 100 mm, the decrease in return loss can be suppressed. The reason why the return loss decreases when the twisting pitch is 100 mm or more is presumed to be, but not limited to, as follows: That is, when the twisting pitch is 100 mm or more, the twisting pitch is likely to change when the communication cable 1 is bent, which affects the return loss. In contrast, when the twisting pitch is less than 100 mm, the twisting pitch is unlikely to change and the return loss is unlikely to decrease.

[0017] The winding tape 20 is wound laterally around the cable core 10 to cover the cable core 10. In this specification, "winding laterally" means winding a long tape spirally along the length of the object to be wound, with the side edges of the tape overlapping the previously wound tape. The winding tape 20 maintains a constant distance between the conductor 2 of the cable core 10 and the shielding layer 30. The configuration of the winding tape 20 is not particularly limited. The winding tape 20 may be, for example, a nonwoven fabric tape or a resin tape, with a nonwoven fabric tape being preferred. Examples of nonwoven fabric tapes include nonwoven fabric tapes containing one or more fibers selected from the group consisting of polyester fibers, polypropylene fibers, aramid fibers, nylon fibers, acrylic fibers, and glass fibers. Examples of resin tapes include polypropylene tapes and high-density polyethylene tapes. In this embodiment, the winding tape 20 is a polyethylene terephthalate (PET) nonwoven fabric tape. The thickness of the winding tape 20 is not particularly limited, but is preferably within a range of 0.1 to 0.5 mm. When the winding tape 20 is a nonwoven fabric tape, the basis weight of the nonwoven fabric tape is 90 to 110 g / m 2 It is preferable that the range is 95 to 105 g / m 2 It is particularly preferable that the range is: Furthermore, when the winding tape 20 is a nonwoven fabric tape, the variation in the measured thickness of the nonwoven fabric tape is preferably within a range of 1.5 to 5.5%. Here, "variation in measured thickness" refers to the value (%) obtained by measuring the thickness of the nonwoven fabric tape at 20 locations along the length of a 1-meter piece of communication cable 1, calculating the difference between the maximum and minimum deviations from the average value (mm), and dividing the calculated values ​​by the average value. The number of sheets of the winding tape 20 is not particularly limited as long as it does not impair the object and effect of this embodiment.

[0018] The width of the winding tape 20 is preferably greater than 5 mm and less than 25 mm. For example, the width of the winding tape 20 is within a range of 10 to 20 mm. By making the width of the winding tape 20 less than 25 mm, the winding pitch of the winding tape 20 wound around the cable core 10 is shortened, which suppresses sharp corners in the winding tape 20 even when the communication cable 1 is bent, and stabilizes the distance between the conductor 2 of the cable core 10 and the shielding layer 30. By stabilizing the distance between the conductor 2 and the shielding layer 30 in this way, the uniformity of the communication cable 1 is improved and a decrease in return loss (RL) is suppressed. On the other hand, it is difficult to make the width of the winding tape 20 5 mm or less in terms of manufacturing. The winding pitch of the winding tape 20 is not particularly limited and can be set appropriately depending on the width of the winding tape 20. For example, the ratio of the winding pitch of the winding tape 20 to the width of the winding tape 20 is within the range of 0.47 to 0.73.

[0019] The shielding layer 30 covers the outer periphery of the winding tape 20. The shielding layer 30 protects the cable core 10 and also blocks external electromagnetic waves. For example, the shielding layer 30 may be made of a metal laminate tape. Examples of metal laminate tapes include Al / PET tapes in which aluminum foil (Al) is laminated on a polyethylene terephthalate film. It is preferable that a slit is formed in the aluminum foil portion to block electrical conduction. In this embodiment, the shielding layer 30 is an Al / PET tape. The tape-shaped shielding layer 30 is wound transversely on the winding tape 20 along the length direction of the cable core 10. The thickness of the shielding layer 30 is not particularly limited as long as it can exhibit the above functions, and may be appropriately selected. The thickness of the shielding layer 30 is, for example, within the range of 0.01 to 0.1 mm.

[0020] The jacket 40 is a so-called sheath that covers the shielding layer 30. The jacket 40 is the outermost layer of the communication cable 1 and protects the cable core 10. The material of the outer sheath 40 is not particularly limited as long as it can perform the above functions. Examples of materials for the outer sheath 40 include polyvinyl chloride and polyolefin. In this embodiment, the material of the outer sheath 40 is polyvinyl chloride. There are no particular limitations on the thickness of the outer jacket 40. The thickness of the outer jacket 40 is, for example, within the range of 0.3 to 1.0 mm.

[0021] The outer diameter of the communication cable 1 is not particularly limited, but the communication cable 1 according to this embodiment is excellent in flexibility, return loss (RL), and near-end crosstalk attenuation (NEXT) even when it has a small diameter. That is, the communication cable 1 according to this embodiment is particularly effective when it has a small diameter. For example, the outer diameter of the communication cable 1 may be within a range of 3.0 to 6.5 mm.

[0022] (Communication cable manufacturing method) There are no particular limitations on the method for manufacturing the communication cable 1 according to this embodiment. For example, the communication cable 1 can be manufactured by the following procedure.

[0023] First, a single annealed copper wire is prepared as the conductor 2. While conveying the conductor 2 in the longitudinal direction, polyethylene is extruded from the die of an extruder, and the conductor 2 is covered with an insulating layer 4 to produce an insulated wire 6. Next, two insulated wires 6 are twisted together to produce a twisted pair wire 8. Four pairs of twisted pair wires 8 are twisted along the cross inserts 9 at a predetermined twisting pitch (more than 40 mm and less than 100 mm) to produce a cable core 10.

[0024] Next, a winding tape 20 having a predetermined width (more than 5 mm and less than 25 mm) is wound around the cable core 10. At this time, the ratio of the winding pitch of the winding tape 20 to the width of the winding tape 20 is preferably within a range of 0.47 to 0.73.

[0025] Next, the shielding layer 30 is formed around the roll 20. For example, a tape-shaped shielding layer 30 is wound transversely around the roll 20. Finally, while the cable core 10 wrapped with the winding tape 20 and the shielding layer 30 is conveyed in the lengthwise direction, polyvinyl chloride is extruded from the die of the extruder to coat the shielding layer 30 with the outer jacket 40 .

[0026] Through the above procedure, the communication cable 1 can be manufactured.

[0027] (effect) The communication cable 1 of this embodiment has a twisting pitch of the cable core 10 that is greater than 40 mm and less than 100 mm, and a width of the winding tape 20 that is greater than 5 mm and less than 25 mm, so that even though it has a small diameter, it has excellent flexibility, return loss, and near-end crosstalk attenuation (see examples).

[0028] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. [Example]

[0029] 1. Manufacture of communication cables A 0.4 mm diameter annealed copper wire (single wire) was prepared as the conductor. High-density polyethylene was prepared as the insulating resin, and this was extruded through the die of an extruder to cover the conductor with an insulator, producing an insulated wire with an outer diameter of 0.7 mm. Two insulated wires were twisted together to produce a twisted pair wire with an outer diameter of approximately 1.4 mm. A cross-shaped wire insert with a radial length of 3.5 mm and a thickness of 0.5 mm was prepared, and four pairs of twisted wires were twisted along the cross-shaped wire insert at a specified twisting pitch (40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm) to produce a cable core.

[0030] The tape is wound with a specified width (5mm, 10mm, 15mm, 20mm or 25mm) of polyester nonwoven fabric tape (thickness 0.35mm, basis weight 100g / m 2) was prepared and wound horizontally around the cable core. The winding pitch of the nonwoven fabric tape was 2.0 mm when the tape width was 5 mm, 5.3 mm when the tape width was 10 mm, 9.7 mm when the tape width was 15 mm, 14.1 mm when the tape width was 20 mm, and 27.0 mm when the tape width was 25 mm. Note that when the tape width was 5 mm, the nonwoven fabric tape could not be wound properly.

[0031] As a shielding layer, an Al / PET tape (aluminum: thickness 9 μm, PET: thickness 43 μm, width 22 mm) with a fixed slit was prepared and wrapped horizontally around the roll, overlapping by 7.3 mm (1 / 3 wrap). Finally, polyvinyl chloride was prepared as the resin for the outer sheath, and this was extruded through the die of the extruder to cover the shielding layer with an outer sheath (thickness 0.4 mm), producing a communication cable with an outer diameter of approximately 6.0 mm.

[0032] 2.Evaluation of communication cables The flexibility, return loss (RL), and near-end crosstalk attenuation (NEXT) of each communication cable were measured. Note that when a nonwoven fabric tape with a tape width of 5 mm was used for winding, it was not possible to manufacture a communication cable, so the flexibility, return loss (RL), and near-end crosstalk attenuation (NEXT) were not measured.

[0033] (flexibility) A 50cm sample was cut from each communication cable. One 30cm section of each sample was fixed to a workbench, and the other 20cm section was left open to the air, forming a free end. A 50g load was applied to the free end, and the amount of deflection of the free end in the vertical direction (the vertical distance from the top of the workbench to the free end) was measured. As a result, all of the communication cables had a flexure of 100 mm or more, and had good flexibility.

[0034] (RL and NEXT) A 100m sample was cut from each communication cable, and the return loss (RL) and near-end crosstalk attenuation (NEXT) of each sample were measured using a general-purpose LAN cable automatic measuring device. For the evaluation of return loss (RL) and near-end crosstalk attenuation (NEXT), the standard values ​​of the ANSI / TIA Category 6A standard were used as the standard. If the standard was met with a margin of 4 dB or more, it was given a "◎", if the standard was met with a margin of 2 dB or more but less than 4 dB, it was given a "〇", if the standard was met with a margin of less than 2 dB, it was given a "△", and if the standard was not met, it was given an "×". The evaluation results for each communication cable are shown in Tables 1 and 2. A "-" in the tables indicates that the return loss (RL) or near-end crosstalk attenuation (NEXT) was not measured.

[0035] [Table 1] [Table 2]

[0036] As shown in Tables 1 and 2, communication cables with a tape width of more than 5 mm and less than 25 mm and a core twist pitch of more than 40 mm and less than 100 mm had a small outer diameter of about 6.0 mm and excellent flexibility, yet met the Category 6A standards for return loss (RL) and near-end crosstalk (NEXT). On the other hand, when the width of the wound tape was 25 mm or more, the return loss (RL) decreased and the Category 6A standard could not be met. Furthermore, even if the width of the tape is greater than 5 mm and less than 25 mm, if the twisting pitch of the cable core is 40 mm or less or 100 mm or more, the return loss (RL) or near-end crosstalk attenuation (NEXT) decreases, and the Category 6A standard cannot be met. [Industrial Applicability]

[0037] The communication cable according to the present invention is useful, for example, as a small-diameter twisted pair cable for LAN. [Explanation of symbols]

[0038] 1 Communication cable 2 conductors 4. Insulation layer 6. Insulated wire 8 twisted pair wire 9 Cruciform intervention 10 cable cores 20 Rolled Tape 30 Shielding layer 40 Outer cover

Claims

1. a cable core including a plurality of twisted wire pairs and an interposer for spacing the plurality of twisted wire pairs from one another; a winding tape wound laterally around the cable core; a shielding layer covering the wound tape; an outer jacket covering the shielding layer; and The width of the wound tape is greater than 5 mm and less than 25 mm; The twisting pitch of the cable core is more than 40 mm and less than 100 mm. Communication cable.

2. 2. The communication cable according to claim 1, The width of the wound tape is within the range of 10 to 20 mm, The twisting pitch of the cable core is in the range of 50 to 90 mm. Communication cable.

3. 2. The communication cable according to claim 1, A communication cable, characterized in that the ratio of the winding pitch of the winding tape to the width of the winding tape is within a range of 0.47 to 0.

73.

4. The communication cable according to any one of claims 1 to 3, A communication cable, characterized in that the outer diameter of the communication cable is within a range of 3.0 to 6.5 mm.

5. The communication cable according to any one of claims 1 to 3, A communication cable, characterized in that the winding tape is a nonwoven fabric tape containing one or more fibers selected from the group consisting of polyester fibers, polypropylene fibers, aramid fibers, nylon fibers, acrylic fibers, and glass fibers.

6. 6. The communication cable according to claim 5, The basis weight of the nonwoven fabric tape is 90 to 110 g / m ２ A communication cable characterized in that it is within the range of

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