Communication cable

Abstract

To provide a communication cable that can improve flexibility while maintaining reflection attenuation and near-end crosstalk attenuation even with a small diameter. 【Solution means】The communication cable 1 includes a cable core 10, a winding tape 20 wound around the cable core 10, a shielding layer 30 covering the winding tape 20, and an outer sheath 40 covering the shielding layer 30. The cable core 10 includes a plurality of pairs of twisted wires 8 and an intervening member 9 for separating the plurality of pairs of twisted wires 8 from each other. The width of the winding tape 20 is more than 5 mm and less than 25 mm. The twist pitch of the cable core 10 is more than 40 mm and less than 100 mm.

Description

Technical Field

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

Background Art

[0002] Communication cables such as LAN (Local Area Network) cables are used for connecting various devices, such as between servers, between a server and a switch, and between a server and a personal computer. In recent years, there has been a demand for communication cables suitable for high-speed data communication that 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 have the problem that they are hard and tend to repel, making it difficult for workers to lay them. For this reason, various means for increasing the flexibility of communication cables have been proposed. For example, in Patent Document 1, the present inventors have proposed improving the flexibility of a communication cable by using a non-woven tape with a basis weight of 90 to 110 g / m as a wrap. 2 The present inventors have proposed improving the flexibility of a communication cable by using a non-woven tape with a basis weight of 90 to 110 g / m as a wrap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In applications where wiring is done at high density, communication cables with a small outer diameter of about 3.0 to 6.5 mm may be used. The present inventors attempted to improve the flexibility of such a small-diameter communication cable by using the non-woven tape with the above-mentioned basis weight as a wrap, but the return loss (RL) and near end crosstalk (NEXT) of the communication cable were significantly reduced.

[0006] An object of the present invention is to provide a communication cable that can improve flexibility while maintaining reflection attenuation and near-end crosstalk attenuation even if the diameter is small.

Means for Solving the Problems

[0007] A communication cable for solving the above problems includes: a cable core including a plurality of pairs of twisted wires and an intervening member for separating the plurality of pairs of twisted wires from each other; a winding tape wound around the cable core; a shielding layer covering the winding tape; an outer sheath covering the shielding layer; and has wherein the width of the winding tape is more than 5 mm and less than 25 mm, and the twisting pitch of the cable core is more 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 improve flexibility while maintaining reflection attenuation and near-end crosstalk attenuation even if the diameter is small.

Brief Description of the Drawings

[0009]

Figure 1

Embodiments for Carrying Out the Invention

[0010] Hereinafter, a so-called LAN twisted pair cable as a communication cable according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited thereto. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions.

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

[0012] The cable core 10 includes a plurality of pairs of twisted wires 8 and an intervening member 9 for separating the plurality of pairs of twisted wires 8 from each other. The plurality of pairs of twisted wires 8 and the intervening member 9 are twisted together in a certain direction at a predetermined twisting pitch. Here, the "twisting pitch" means the lengthwise distance of the cable core 10 required for one pair of twisted wires 8 to make one turn when the plurality of pairs of twisted wires 8 and the intervening member 9 are twisted together.

[0013] Each of the plurality of pairs of twisted wires 8 has two insulated wires 6. In each pair of twisted wires 8, the two insulated wires 6 are twisted together in a certain direction at a predetermined pair-twisting pitch. Here, the "pair-twisting pitch" means the lengthwise distance of the pair of twisted wires 8 required for one of the insulated wires 6 to make one turn when the two insulated wires 6 are twisted together. The number of pairs of twisted wires 8 is not particularly limited as long as it is plural. In this embodiment, the number of pairs of twisted wires 8 is 4 pairs.

[0014] The insulated wire 6 has a conductor 2 and an insulating layer 4 covering the conductor 2. The conductor 2 is a wire formed of a conductive metal material. The type of the conductor 2 is not particularly limited. In the present embodiment, the conductor 2 is a soft copper wire. The conductor 2 may be a single wire or a stranded wire formed by twisting a plurality of strands. The outer diameter (equivalent circular diameter) of the conductor 2 is not particularly limited and is appropriately selected according to the use and type of the communication cable 1. The diameter of the conductor 2 is, for example, in the 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 the present embodiment, the insulating layer 4 is made of polyethylene. The thickness of the insulating layer 4 is not particularly limited and is appropriately selected. The thickness of the insulating layer 4 is, for example, in the range of 0.1 to 0.3 mm.

[0015] The intervening member 9 extends in the length direction of the communication cable 1 and separates a plurality of pairs of twisted pairs 8 from each other. That is, the plurality of pairs of twisted pairs 8 are separated by the intervening member 9 so as not to contact each other. The shape of the intervening member 9 is not particularly limited as long as it can separate the plurality of pairs of twisted pairs 8 from each other. In the present embodiment, the cross-sectional shape of the intervening member 9 orthogonal to the length direction of the communication cable 1 is in the shape of a plus sign. That is, the intervening member 9 is a so-called cross intervening member. The material of the intervening member 9 is also not particularly limited as long as it can exhibit the above functions. In the present embodiment, the material of the intervening member 9 is polyethylene. The intervening member 9 is twisted along the length direction of the cable core 10 (communication cable 1). Accordingly, the plurality of pairs of twisted pairs 8 are also twisted along the length direction of the cable core 10 (communication cable 1) while being separated by the intervening member 9.

[0016] As described above, the cable core 10 (a plurality of pairs of twisted pairs 8 and the intervening member 9) is twisted in a certain direction at a predetermined twisting pitch. As described above, the "twisting pitch" means the distance in the length direction of the cable core 10 required for a pair of twisted pairs 8 to make one turn when the plurality of pairs of twisted pairs 8 and the intervening member 9 are twisted together. Here, the twisting pitch of the cable core 10 is preferably more than 40 mm and less than 100 mm. For example, the twisting pitch of the cable core 10 is in the range of 50 to 90 mm. In the communication cable 1 according to the present embodiment, when the twisting pitch is 40 mm or less, the near-end crosstalk attenuation (NEXT) is likely to decrease. However, by setting the twisting pitch to more than 40 mm, it is possible to suppress the decrease in the near-end crosstalk attenuation. The reason why the near-end crosstalk attenuation decreases when the twisting pitch is 40 mm or less is presumably as follows, although it is not limited to this. That is, when the twisting pitch is 40 mm or less, the twisting pitch of the pair wire 8 is likely to change due to the influence of the twisting pitch, and as a result, the near-end crosstalk attenuation decreases. On the other hand, when the twisting pitch is more than 40 mm, the twisting pitch of the pair wire 8 is less likely to change, and the near-end crosstalk attenuation is less likely to decrease. Also, in the communication cable 1 according to the present embodiment, when the twisting pitch is 100 mm or more, the return loss (RL) is also likely to decrease. However, by setting the twisting pitch to less than 100 mm, it is possible to suppress the decrease in the return loss. The reason why the return loss decreases when the twisting pitch is 100 mm or more is presumably as follows, although it is not limited to this. 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, and as a result, the return loss decreases. On the other hand, when the twisting pitch is less than 100 mm, the twisting pitch is less likely to change, and the return loss is less likely to decrease.

[0017] The wrapping tape 20 is wound horizontally around the cable core 10 and covers the cable core 10. In this specification, "horizontal winding" means winding a long tape in a spiral shape along the length direction of the object to be wound, while overlapping the tape with the side edge portion of the tape wound first. The wrapping tape 20 keeps the distance between the conductor 2 and the shielding layer 30 of the cable core 10 constant. The configuration of the winding tape 20 is not particularly limited. The winding tape 20 is, for example, a non-woven tape or a resin tape, and a non-woven tape is preferred. Examples of non-woven tapes include non-woven 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 the present embodiment, the winding tape 20 is a non-woven tape of polyethylene terephthalate (PET). The thickness of the winding tape 20 is not particularly limited, but is preferably in the range of 0.1 to 0.5 mm. When the winding tape 20 is a non-woven tape, the basis weight of the non-woven tape is preferably 2 in the range of 90 to 110 g / m 2 and particularly preferably in the range of 95 to 105 g / m. Also, when the winding tape 20 is a non-woven tape, the variation in the measured thickness of the non-woven tape is preferably in the range of 1.5 to 5.5%. Here, the "variation in the measured thickness" means that when 1 m of the communication cable 1 is cut out, the thickness of the non-woven tape included in the cut-out piece is measured at 20 locations along the length direction, and the difference between the maximum deviation amount and the minimum deviation amount with respect to the average value (mm) is calculated respectively, and the value (%) obtained by dividing the calculated value by the average value. The number of winding tapes 20 is not particularly limited as long as the object and effect of the present embodiment are not impaired.

[0018] The width of the winding tape 20 is preferably more than 5 mm and less than 25 mm. For example, the width of the winding tape 20 is in the range of 10 to 20 mm. By setting the width of the winding tape 20 to less than 25 mm, the winding pitch of the winding tape 20 wound around the cable core 10 becomes shorter, and even when the communication cable 1 is bent, the cornering of the winding tape 20 is suppressed, and the distance between the conductor 2 of the cable core 10 and the shielding layer 30 is stabilized. By thus stabilizing the distance between the conductor 2 and the shielding layer 30, the uniformity in the communication cable 1 is improved, and a decrease in the reflection attenuation amount (RL) is suppressed. On the other hand, setting the width of the winding tape 20 to 5 mm or less is difficult in manufacturing. The winding pitch of the winding tape 20 is not particularly limited and can be appropriately set according to 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 in 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 blocks electromagnetic waves from the outside. For example, the shielding layer 30 may be composed of a metal laminate tape. Examples of the metal laminate tape include an Al / PET tape in which an aluminum foil (Al) is laminated on a polyethylene terephthalate film. It is preferable that a slit for blocking conduction is formed in the aluminum foil portion. In the present embodiment, the shielding layer 30 is an Al / PET tape. The tape-shaped shielding layer 30 is wound horizontally 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 the above functions can be exhibited and is appropriately selected. The thickness of the shielding layer 30 is, for example, in the range of 0.01 to 0.1 mm.

[0020] The outer sheath 40 is a so-called sheath that covers the shielding layer 30. The outer sheath 40 is the outermost layer of the communication cable 1 and protects the cable core 10. The material of the jacket 40 is not particularly limited as long as it can exhibit the above functions. Examples of the material of the jacket 40 include polyvinyl chloride and polyolefin. In the present embodiment, the material of the jacket 40 is polyvinyl chloride. The thickness of the jacket 40 is not particularly limited. The thickness of the jacket 40 is, for example, in 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 the present embodiment is excellent in flexibility, return loss (RL), and near-end crosstalk loss (NEXT) even if it has a small diameter. That is, the communication cable 1 according to the present embodiment can exhibit a particularly effective effect when it has a small diameter. For example, the outer diameter of the communication cable 1 may be in the range of 3.0 to 6.5 mm.

[0022] (Method for manufacturing a communication cable) The manufacturing method of the communication cable 1 according to the present embodiment is not particularly limited. For example, the communication cable 1 can be manufactured by the following procedure.

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

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

[0025] Next, the shielding layer 30 is formed around the wrapping 20. For example, a tape-shaped shielding layer 30 is wound around the wrapping 20 horizontally. Finally, while transporting the cable core 10 wrapped with the pressure-sensitive tape 20 and the shielding layer 30 in the longitudinal direction, polyvinyl chloride is extruded from the die of an extruder to cover the periphery of the shielding layer 30 with the outer sheath 40.

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

[0027] (Effect) In the communication cable 1 according to the present embodiment, since the twisting pitch of the cable core 10 is more than 40 mm and less than 100 mm, and the width of the pressure-sensitive tape 20 is more than 5 mm and less than 25 mm, even if the diameter is small, it is excellent in flexibility, reflection attenuation amount, and near-end crosstalk attenuation amount (see the examples).

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

Example

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

[0030] As the pressure-sensitive tape, a polyester non-woven fabric tape with a predetermined tape width (5 mm, 10 mm, 15 mm, 20 mm, or 25 mm) (thickness 0.35 mm, basis weight 100 g / m 2Prepare and wind it horizontally around the cable core. At this time, the winding pitch of the non-woven 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 non-woven tape could not be wound properly.

[0031] As the shielding layer, prepare an Al / PET tape (aluminum: thickness 9 μm, PET: thickness 43 μm, width 22 mm) with certain slits and wind it horizontally around the periphery of the spiral winding. At this time, it was wound with an overlap of 7.3 mm (1 / 3 lap) each time. Finally, prepare polyvinyl chloride as the resin for the outer sheath, extrude it from the die of the extruder to coat the shielding layer with the outer sheath (thickness 0.4 mm), and manufacture a communication cable with an outer diameter of about 6.0 mm.

[0032] 2. Evaluation of communication cables For each communication cable, flexibility, return loss (RL), and near-end crosstalk loss (NEXT) were measured. Note that when using a non-woven tape with a tape width of 5 mm as the spiral winding, a communication cable could not be manufactured, so the measurements of flexibility, return loss (RL), and near-end crosstalk loss (NEXT) were not performed either.

[0033] (Flexibility) Cut out a 50-cm-long sample from each communication cable. For each sample, fix the 30-cm-long part on one end side to the workbench and leave the 20-cm-long part on the other end side open in space as a free end. Apply a 50-g load to the free end and measure the amount of deflection in the vertical direction of the free end (the vertical distance from the upper surface of the workbench to the free end). As a result, the amount of deflection of each communication cable was 100 mm or more, indicating good flexibility.

[0034] (RL and NEXT) Samples of 100 m in length were cut out from each communication cable. For each sample, the return loss (RL) and near-end crosstalk loss (NEXT) were measured using a general-purpose automatic LAN cable measuring device. Regarding the evaluation of the return loss (RL) and near-end crosstalk loss (NEXT), based on the standard values of Category 6A of the ANSI / TIA standard, the case where the standard was met with a margin of 4 dB or more was evaluated as "◎", the case where the standard was met with a margin of 2 dB or more and less than 4 dB was evaluated as "〇", the case where the standard was met with a margin of less than 2 dB was evaluated as "△", and the case where the standard was not met was evaluated as "×". The evaluation results of each communication cable are shown in Table 1 and Table 2. The "-" in the table indicates that the measurement of the return loss (RL) or near-end crosstalk loss (NEXT) was not performed.

[0035]

Table 1

Table 2

[0036] As shown in Table 1 and Table 2, the communication cable with a width of the wrapping tape exceeding 5 mm and less than 25 mm, and a twisting pitch of the cable core exceeding 40 mm and less than 100 mm had a small outer diameter of about 6.0, and while having excellent flexibility, it met the Category 6A standard for the return loss (RL) and near-end crosstalk loss (NEXT). On the other hand, when the width of the wrapping tape was 25 mm or more, the return loss (RL) decreased and the Category 6A standard could not be met. Also, even when the width of the wrapping tape exceeded 5 mm and was less than 25 mm, when the twisting pitch of the cable core was 40 mm or less or 100 mm or more, the return loss (RL) or near-end crosstalk loss (NEXT) decreased and the Category 6A standard could not be met.

Industrial Applicability

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

Explanation of Signs

[0038] 1 Communication cable 2 Conductor 4 Insulation layer 6 Insulated wire 8 Twisted pair 9 Cross intervention 10 Cable core 20 Wrapping tape 30 Shielding layer 40 Outer sheath

Claims

1. A cable core including a plurality of twisted wire pairs and a spacer for spacing the plurality of twisted wire pairs from each other; A winding tape wound transversely around the cable core; A shielding layer covering the wound tape; An outer cover covering the shielding layer; having The width of the wound tape is greater than 5 mm and less than 25 mm; The twist 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 rolled tape is within a range of 10 to 20 mm. The twist pitch of the cable core is within a 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, wherein 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 types of 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 nonwoven fabric tape has a basis weight of 90 to 110 g / m ２ A communication cable, characterized in that the range is within the range.

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