Composite cable and method for manufacturing the same

Abstract

To provide a composite cable configured to reduce reflection attenuation and near end crosstalk attenuation.SOLUTION: A composite cable includes a LAN cable, a coaxial cable, a press winding layer that covers the LAN cable and the coaxial cable, and an outer layer that covers the press winding layer. The LAN cable and the coaxial cable are twisted together. The composite cable satisfies 17≤(P / D)<30, where D is a maximum length in a cross section perpendicular to a length direction of the composite cable in a region surrounded by the press winding layer, and P is a collection pitch of the composite cable.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a composite cable and a method for manufacturing the same.

Background Art

[0002] For providing Internet, TV, and telephone services to each room in a building, it is necessary to wire a LAN cable (Internet), a coaxial cable (TV), and a telephone cable (telephone). These cables are either wired separately or are wired in a state where each cable is bundled together (see, for example, Patent Document 1).

[0003] Patent Document 1 describes a listening composite cable (composite cable) including a LAN cable including a conductor for a LAN cable, a coaxial cable including a shield conductor of a coaxial cable for TV reception, and a telephone cable including a conductor of a telephone cable.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A composite cable for simultaneous listening described in Patent Document 1 or the like may be manufactured by twisting a LAN cable, a coaxial cable, and a telephone cable. In recent years, for the LAN cable of the composite cable for simultaneous listening, a Cat.6A product corresponding to a frequency of 500 MHz has been demanded. However, in a composite cable in which a LAN cable corresponding to Cat.6A, a coaxial cable, and a telephone cable are twisted, the near-end crosstalk (NEXT) or return loss (RL) of the LAN cable may increase. Therefore, it is desired to provide a high-quality communication cable with more stable electrical characteristics.

[0006] Therefore, a main object of the present invention is to provide a composite cable and a manufacturing method thereof in which an increase in the return loss and near-end crosstalk of a LAN cable is suppressed.

Means for Solving the Problems

[0007] In order to solve the above problems, according to one aspect of the present invention, A composite cable having a LAN cable, a coaxial cable, a wrapping layer covering the LAN cable and the coaxial cable, and an outer covering layer covering the wrapping layer, The LAN cable and the coaxial cable are twisted together, When the maximum length in a cross section orthogonal to the length direction of the composite cable in the region surrounded by the wrapping layer is D and the collective pitch of the composite cable is P, a composite cable satisfying the following formula (1) is provided. Formula (1) 17 ≦ (P / D) < 30

[0008] According to another aspect of the present invention, A method for manufacturing a composite cable having a LAN cable, a coaxial cable, a wrapping layer covering the LAN cable and the coaxial cable, and an outer covering layer covering the wrapping layer, A step of preparing the LAN cable and the coaxial cable, Let D be the maximum length in the cross-section orthogonal to the longitudinal direction of the composite cable in the region surrounded by the press winding layer, and let P be the set pitch of the composite cable. A method for manufacturing a composite cable is provided, which includes a step of twisting the LAN cable and the coaxial cable so as to satisfy the following formula (1). Formula (1) 17 ≤ (P / D) < 30

Effect of the Invention

[0009] According to the present invention, it is possible to provide a composite cable in which an increase in the return loss and the near-end crosstalk attenuation of the LAN cable is suppressed, and a method for manufacturing the same.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiment for Carrying Out the Invention

[0011] Hereinafter, a composite cable and a method for manufacturing the same according to an embodiment of the present invention will be described. However, the composite cable and the method for manufacturing the same of the present invention are not limited to the embodiments shown below. In this specification, the “~” indicating a numerical range includes the upper limit value and the lower limit value in the numerical range.

[0012] (Configuration of the Composite Cable) FIG. 1A is a cross-sectional view of a composite cable 10 having an intervening member 50 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view of a composite cable 10 not having the intervening member 50. FIG. 2A is a side view for explaining an example in which a LAN cable 20 and a coaxial cable 30 are twisted together, FIG. 2B is a side view for explaining an example in which the LAN cable 20 is wound around the coaxial cable 30, FIG. 2C is a side view for explaining an example in which the LAN cable 20 and a telephone cable are wound around the coaxial cable 30, and FIG. 2D is a schematic cross-sectional view of the LAN cable 20 and the coaxial cable 30 corresponding to FIG. 2B.

[0013] The composite cable 10 has a LAN cable 20, a coaxial cable 30, and an outer sheath layer 70. In addition to the above configuration, the composite cable 10 may have any one or more of a telephone cable 40, an intervening member 50, and a winding layer 60. As shown in FIG. 1A, in the present embodiment, the composite cable 10 has a LAN cable 20, a coaxial cable 30, a telephone cable 40, an intervening member 50, a winding layer 60, and an outer sheath layer 70.

[0014] As shown in FIGS. 2A and 2B, the LAN cable 20 and the coaxial cable 30 are twisted together. Here, being twisted together includes twisting the LAN cable 20 and the coaxial cable 30 together (see FIG. 2A) and winding the LAN cable 20 around the coaxial cable 30 (see FIG. 2B). In the present embodiment, as shown in FIG. 2C, the LAN cable 20 and the telephone cable 40 are wound around the coaxial cable 30. Note that the LAN cable 20, the coaxial cable 30, and the telephone cable 40 may be twisted together (not shown).

[0015] When the maximum length in a cross section orthogonal to the length direction of the composite cable 10 in the region surrounded by the winding layer 60 of the composite cable 10 is D and the collective pitch of the composite cable 10 is P, the composite cable 10 satisfies the following formula (1). It is preferable that the composite cable 10 also satisfies the following formula (2). Formula (1) 17 ≦ (P / D) < 30 Equation (2): 20 ≦ (P / D) ≦ 27

[0016] Here, as shown in FIGS. 1A and 1B, D means the maximum length in a cross section orthogonal to the longitudinal direction of the composite cable 10 in the region surrounded by the press-wound layer 60. In the present embodiment, as shown in FIG. 1A, in the composite cable 10 having the intervening member 50, it means D1, and as shown in FIG. 1B, in the composite cable 10 not having the intervening member 50, it means D2. For example, the maximum length D is preferably in the range of 12 to 20 mm.

[0017] As shown in FIGS. 2A, 2B, and 2C, P is the collective pitch. As shown in FIG. 2A, when the LAN cable 20 and the coaxial cable 30 are twisted together, it means the distance in the longitudinal direction of the composite cable 10 required for the LAN cable 20 or the coaxial cable 30 to make one turn. On the other hand, as shown in FIGS. 2B, 2C, and 2D, when the LAN cable 20 is wound around the coaxial cable 30, it means the distance in the longitudinal direction of the composite cable 10 required for the LAN cable 20 to make one turn around the coaxial cable 30. In the present embodiment, the collective pitch means the distance in the longitudinal direction of the composite cable 10 required for the LAN cable 20 or the telephone cable 40 to make one turn around the coaxial cable 30. The collective pitch P is preferably in the range of, for example, 250 to 450 mm, and more preferably in the range of 300 to 400 mm.

[0018] When (P / D) exceeds 30, the reflection attenuation amount of the LAN cable 20 increases. On the other hand, when (P / D) is less than 17, the near-end crosstalk attenuation amount of the LAN cable 20 increases.

[0019] The LAN cable 20 has a cable core 21, a first press-wound layer 22, a first shielding layer 23, and a first outer sheath layer 24.

[0020] The cable core 21 has a plurality of first twisted pairs 25 and a cross intervening member 26 for separating the plurality of first twisted pairs 25 from each other.

[0021] The first pair of twisted wires 25 has two first insulated wires 27. The first pair of twisted wires 25 is formed by twisting the two first insulated wires 27 so as to have a predetermined twist pitch. The number of the first pairs of twisted wires 25 is not particularly limited as long as it is plural. In the present embodiment, the number of the first pairs of twisted wires 25 is four. The first pair of twisted wires 25 is formed by twisting a plurality of (two in the present embodiment) first insulated wires 27 in a certain direction. Here, the twist pitch means the lengthwise distance of the first pair of twisted wires 25 required for one of the first insulated wires 27 to make one full turn when the two first insulated wires 27 are twisted together as a whole.

[0022] The first insulated wire 27 has a first conductor 28 and a first insulating layer 29 covering the first conductor 28.

[0023] The first conductor 28 is a wire formed of a conductive metal material. The type of the first conductor 28 is not particularly limited as long as it is formed of a conductive metal material. In the present embodiment, the first conductor 28 is a soft copper wire. The first conductor 28 may be a single wire or a stranded wire formed by twisting a plurality of strands. The thickness of the first conductor 28, that is, the diameter of the cross section orthogonal to the length direction is not particularly limited and is appropriately selected according to the use and type of the LAN cable 20. The diameter of the first conductor 28 is, for example, in the range of 0.3 to 0.6 mm.

[0024] The first insulating layer 29 covers the first conductor 28. The material of the first insulating layer 29 is not particularly limited as long as it has insulating properties. In the present embodiment, the first insulating layer 29 is made of polyethylene. The thickness of the first insulating layer 29 is not particularly limited and is appropriately selected. The thickness of the first insulating layer 29 is, for example, in the range of 0.1 to 0.3 mm.

[0025] The cross-shaped interposition 26 separates the first pair of twisted wires 25 from each other. The cross-shaped interposition 26 extends in the longitudinal direction of the LAN cable 20. The shape of the cross-shaped interposition 26 is not particularly limited as long as it can isolate the plurality of first pair of twisted wires 25. In the present embodiment, the cross-sectional shape of the cross-shaped interposition 26 orthogonal to the longitudinal direction of the LAN cable 20 is in the shape of a plus sign. Also, the material of the cross-shaped interposition 26 is not particularly limited as long as it can exhibit the above functions. In the present embodiment, the material of the cross-shaped interposition 26 is polyethylene. The cross-shaped interposition 26 is twisted along with the first pair of twisted wires 25 in the longitudinal direction of the composite cable 10.

[0026] The first winding layer 22 covers the cable core 21. The first winding layer 22 keeps the distance between the first conductor 28 and the first shielding layer 23 of the cable core 21 constant. Examples of the material of the first winding layer 22 include non-woven tape made of any one or a combination of two or more of polyester, polypropylene, aramid fiber, nylon, acrylic fiber, or glass fiber. In the present embodiment, the material of the first winding layer 22 is a polyester non-woven tape. The number of non-woven tapes is not particularly limited as long as the object and effect of the present embodiment are not impaired. The basis weight of the non-woven tape constituting the first winding layer 22 is 90 to 110 g / m 2 and preferably 95 to 105 g / m 2 . The thickness of the first winding layer 22 is not particularly limited as long as it can exhibit the above functions and is appropriately selected. The thickness of the first winding layer 22 is, for example, in the range of 0.1 to 0.5 mm.

[0027] The first shielding layer 23 covers the first winding layer 22. The first shielding layer 23 protects the cable core 21 and blocks electromagnetic waves from the outside. The first shielding layer 23 is 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. In the present embodiment, the metal laminate tape of the first shielding layer 23 is an Al / PET tape. A slit for blocking conduction is formed in the aluminum foil portion. The first shielding layer 23 is wound horizontally from above the first winding layer 22. The thickness of the first shielding layer 23 is not particularly limited as long as the above functions can be exhibited, and is appropriately selected. The thickness of the first shielding layer 23 is, for example, in the range of 0.01 to 0.1 mm. Note that the LAN cable 20 may not have the first shielding layer 23.

[0028] The first outer sheath layer 24 covers the first shielding layer 23. The first outer sheath layer 24 protects the cable core 21. The material of the first outer sheath layer 24 is not particularly limited as long as the above functions can be exhibited. Examples of the material of the first outer sheath layer 24 include polyvinyl chloride and polyolefin. In the present embodiment, the material of the first outer sheath layer 24 is polyvinyl chloride. The thickness of the first outer sheath layer 24 is not particularly limited. The thickness of the first outer sheath layer 24 is, for example, in the range of 0.3 to 1.0 mm.

[0029] The coaxial cable 30 includes a second conductor 31, a second insulating layer 32, a second shielding layer 33, a third shielding layer 34, and a second outer sheath layer 35.

[0030] The second conductor 31 is a wire formed of a conductive metal material. The type of the second conductor 31 is not particularly limited as long as it is formed of a conductive metal material. In the present embodiment, the second conductor 31 is a soft copper wire. The second conductor 31 may be a single wire or a stranded wire formed by twisting a plurality of strands together at a predetermined pitch. In the present embodiment, the second conductor 31 is a single wire. The thickness of the second conductor 31, that is, the diameter of the cross section perpendicular to the length direction is not particularly limited and is appropriately selected according to the use and type of the coaxial cable 30, etc. The diameter of the second conductor 31 is, for example, in the range of 0.5 to 3.0 mm.

[0031] The second insulating layer 32 covers the second conductor 31. The material of the second insulating layer 32 is not particularly limited as long as it has insulating properties. In the present embodiment, the material of the second insulating layer 32 is foamed polyethylene. The thickness of the second insulating layer 32 is not particularly limited. The thickness of the second insulating layer 32 is not particularly limited and is appropriately selected. The thickness of the second insulating layer 32 is, for example, in the range of 1.0 to 5.0 mm.

[0032] The second shielding layer 33 covers the second insulating layer 32. The second shielding layer 33 is, for example, a double-sided aluminum foil plastic tape. The thickness of the second shielding layer 33 is, for example, in the range of 0.01 to 0.1 mm.

[0033] The third shielding layer 34 covers the second shielding layer 33. The third shielding layer 34 is, for example, a tinned soft copper wire braid.

[0034] The second outer covering layer 35 covers the third shielding layer 34. The second outer covering layer 35 protects the components inside the third shielding layer 34. Examples of the material of the second outer covering layer 35 include polyvinyl chloride and polyethylene. In the present embodiment, the second outer covering layer 35 is made of polyvinyl chloride. The thickness of the second outer covering layer 35 is not particularly limited. The thickness of the second outer covering layer 35 is not particularly limited as long as the above functions can be exerted and is appropriately selected. The thickness of the second outer covering layer 35 is, for example, in the range of 0.5 to 2.0 mm.

[0035] The telephone cable 40 has a plurality of second twisted pairs 41 and a third outer sheath 42.

[0036] The number of the second twisted pairs 41 is not particularly limited as long as it is plural. In the present embodiment, the number of the second twisted pairs 41 is two. Each second twisted pair 41 is formed by twisting a plurality of (two in the present embodiment) second insulated wires 43 in a certain direction with a predetermined twist pitch. The second insulated wire 43 has a third conductor 44 and a third insulating layer 45 that covers the third conductor 44.

[0037] The third conductor 44 is a wire formed of a conductive metal material. The diameter of the third conductor 44 is, for example, in the range of 0.4 to 0.65 mm.

[0038] The third insulating layer 45 covers the third conductor 44. The material of the third insulating layer 45 is not particularly limited as long as it has insulation properties, and is, for example, resin. In the present embodiment, the third insulating layer 45 is made of polyethylene. The film thickness of the third insulating layer 45 is not particularly limited. The thickness of the third insulating layer 45 is, for example, in the range of 0.1 to 0.3 mm.

[0039] The third outer sheath 42 covers the third insulating layer 45. The third outer sheath 42 protects the third insulating layer 45. Examples of the material of the third outer sheath 42 include polyvinyl chloride and polyethylene. In the present embodiment, the third outer sheath 42 is made of polyvinyl chloride. The thickness of the third outer sheath 42 is not particularly limited. The thickness of the third outer sheath 42 is, for example, in the range of 0.5 to 1.0 mm.

[0040] The intervening member 50 is disposed within a region surrounded by the outer jacket layer 70 other than the LAN cable 20 and the coaxial cable 30. In the example shown in FIG. 1A, the intervening member 50 is disposed within a region surrounded by the outer jacket layer 70 other than the LAN cable 20, the coaxial cable 30, and the telephone cable 40. The intervening member 50 suppresses local loading on the LAN cable 20, the coaxial cable 30, and / or the telephone cable 40 when the composite cable 10 is bent, and makes the cross-section perpendicular to the longitudinal direction of the composite cable 10 substantially circular. The material of the intervening member 50 is not particularly limited as long as it can exhibit the above functions. Examples of the material of the intervening member 50 include synthetic fibers. Examples of synthetic fibers include polypropylene (PP) split and PP-C split in which calcium carbonate is mixed into the PP split. The fineness of the intervening member 50 is preferably in the range of 4800 to 80000 denier, and more preferably in the range of 10000 to 40000 denier. The number of the intervening members 50 is appropriately set according to the fineness of the intervening member 50 used for the composite cable 10. In the present embodiment, the total fineness of the intervening members 50 disposed in the composite cable 10 may be 160000 denier. For example, in the present embodiment, two intervening members 50 with a fineness of 80000 denier may be used, four intervening members 50 with a fineness of 40000 denier may be used, five intervening members 50 with a fineness of 32000 denier may be used, or sixteen intervening members 50 with a fineness of 10000 denier may be used.

[0041] The winding layer 60 covers the LAN cable 20 and the coaxial cable 30. In the present embodiment, the winding layer 60 covers the LAN cable 20, the coaxial cable 30, the telephone cable 40, and the intervening member 50. The type of the winding layer 60 is not particularly limited as long as it can exhibit the above functions. The winding layer 60 is composed of a polyethylene terephthalate tape. The winding method of the polyethylene terephthalate tape may be horizontal winding or vertical winding. In the present embodiment, the winding method of the polyethylene terephthalate tape is horizontal winding. Specifically, the polyethylene terephthalate tape is wound while overlapping a tape wound with the side edge portion of the tape first. The thickness of the winding layer 60 is, for example, in the range of 10 to 50 μm.

[0042] The outer covering layer 70 covers the winding layer 60. Examples of the material of the outer covering layer 70 include polyvinyl chloride and polyethylene. In the present embodiment, the material of the outer covering layer 70 is polyvinyl chloride. The thickness of the outer covering layer 70 is not particularly limited. The thickness of the outer covering layer 70 is, for example, in the range of 0.7 to 1.5 mm. A tearing string 71 may be disposed on the outer covering layer 70.

[0043] The tearing string 71 is disposed inside the outer covering layer 70 in a cross section along the length direction of the composite cable 10. By pulling the tearing string 71, the outer covering layer 70 can be torn. The number of the tearing strings 71 is not particularly limited. In the present embodiment, the tearing string 71 is one. The material of the tearing string 71 is not particularly limited as long as the above functions can be exhibited. In the present embodiment, the material of the tearing string 71 is a polyester cord yarn (Tetoron yarn).

[0044] (Method for manufacturing a composite cable) FIG. 3 is a flowchart of a method for manufacturing the composite cable 10 of the present embodiment.

[0045] The composite cable 10 can be manufactured, for example, by the following method. Here, the composite cable 10 having the LAN cable 20, the coaxial cable 30, the telephone cable 40, the intervening member 50, the winding layer 60, and the outer covering layer 70 will be described.

[0046] The method for manufacturing the composite cable 10 includes a step (S110) of preparing the LAN cable 20 and the coaxial cable 30, and a step (S120) of twisting the LAN cable 20 and the coaxial cable 30 together. In the present embodiment, as shown in FIG. 3, it includes a step (S110) of preparing, a step (S120) of twisting, and a step (S130) of covering.

[0047] In the preparation step (S110), a LAN cable 20 and a coaxial cable 30 are prepared. In the present embodiment, in the preparation step, a LAN cable 20, a coaxial cable 30, and a telephone cable 40 are prepared. As the LAN cable 20, the coaxial cable 30, and the telephone cable 40, commercially available cables 20, 30, and 40 having the above-described configurations may be purchased and prepared, or the cables 20, 30, and 40 may be manufactured and prepared, or some of the cables may be purchased and prepared, and some of the other cables may be manufactured and prepared.

[0048] The LAN cable 20 can be manufactured, for example, by the following method. While conveying the first conductor 28 in the length direction, polyethylene is extruded from the die of an extruder to coat the first conductor 28 with the first insulating layer 29 to form the first insulated wire 27. Next, a plurality (here, two) of the first insulated wires 27 are bundled together and twisted together a predetermined number of times in a predetermined direction to form the first twisted pair 25. Next, after arranging the cross-interposition 26 so that the first twisted pairs 25 do not contact each other, a polyester non-woven tape is wound horizontally to form the first winding layer 22. Next, an Al / PET tape is wound horizontally to form the first shielding layer 23. Next, polyvinyl chloride is extruded from the die of an extruder to coat the first shielding layer 23 with the first outer covering layer 24 to obtain the LAN cable 20.

[0049] The coaxial cable 30 can be manufactured, for example, by the following method. While conveying the second conductor 31 in the length direction, foamed polyethylene is extruded from the die of an extruder to coat the second conductor 31 with the second insulating layer 32. Next, a double-sided aluminum foil plastic tape is wound to form the second shielding layer 33. Next, a tin-plated soft copper wire braid is applied to form the third shielding layer 34. Finally, polyvinyl chloride is extruded from the die of an extruder to coat the third shielding layer 34 with the second outer covering layer 35 to obtain the coaxial cable 30.

[0050] The telephone cable 40 can be manufactured, for example, in the following manner. While transporting the third conductor 44 in the longitudinal direction, polyethylene is extruded from the die of an extruder to coat the third conductor 44 with a third insulating layer 45, thereby forming the second insulated wire 43. Next, a plurality (here, two) of the second insulated wires 43 are bundled together and twisted in a predetermined direction a predetermined number of times to form the second twisted pair 41. Next, polyvinyl chloride is extruded from the die of an extruder to coat the second twisted pair 41 with a third outer sheath layer 42, thereby obtaining the telephone cable 40.

[0051] In the twisting step (S120), the LAN cable 20 and the coaxial cable 30 are twisted together so as to satisfy predetermined conditions. In the present embodiment, the composite cable 10 twists together the LAN cable 20, the coaxial cable 30, the telephone cable 40, and the spacer 50 all at once. At this time, when the maximum length in the cross-section orthogonal to the longitudinal direction of the composite cable 10 in the region surrounded by the winding layer 60 is D and the collective pitch of the composite cable 10 is P, the twisting is performed so as to satisfy the following formula (1). Formula (1) 17 ≦ (P / D) < 30

[0052] In the covering step (S130), first, the composite cable 10 twists together the LAN cable 20, the coaxial cable 30, the telephone cable 40, and the spacer 50 all at once, and wraps a polyethylene terephthalate tape to form the winding layer 60. Finally, the tearing string 71 is arranged in the longitudinal direction, and polyvinyl chloride is extruded from the die of an extruder to coat it with the outer sheath layer 70, thereby obtaining the composite cable 10.

[0053] (Effect) As described above, according to the present invention, when the maximum length in the cross-section orthogonal to the longitudinal direction of the composite cable 10 in the region surrounded by the winding layer 60 is D and the collective pitch of the composite cable 10 is P, since 17 ≦ (P / D) < 30 is satisfied, an increase in the reflection attenuation amount and an increase in the near-end crosstalk attenuation amount can be suppressed.

Example

[0054] Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by these examples in any way, and the embodiments can be changed without departing from the spirit of the present invention.

[0055] 1. Fabrication of the composite cable (1) Fabrication of the composite cable 1 Polyethylene was extruded and coated on a soft copper wire (the first conductor) to form a first insulated wire having a first insulator. Next, two insulated wires were twisted (paired-twisted) to form a first paired-twisted wire body. Next, with four first paired-twisted bodies arranged in a cross-interposed manner, as a first pressing winding layer, a polyester non-woven fabric tape with a thickness of 0.3 mm was wound in a 1 / 2 overlapping manner (wound while overlapping 1 / 2 of the width of the non-woven fabric tape). Next, as a first shielding layer, an Al / PET tape with a thickness of 0.05 mm was wound in a 1 / 4 overlapping manner. Next, polyvinyl chloride was extruded and coated on the first shielding layer to fabricate a LAN cable with an outer diameter of 7.0 mm.

[0056] Foamed polyethylene was extruded and coated on a soft copper wire (the second conductor) with a diameter of 1.05 mm to form a second insulating layer with a thickness of 1.98 mm. Next, a double-sided aluminum foil plastic tape was wound in a 1 / 4 overlapping manner on the second insulating layer to form a second shielding layer with a thickness of 0.05 mm. Next, a tin-plated soft copper wire braid was applied to the second shielding layer to form a third shielding layer. Finally, polyvinyl chloride was extruded and coated on the third shielding layer to fabricate a coaxial cable with an outer diameter of 7.7 mm.

[0057] Polyethylene was extruded and coated on a soft copper wire (the third conductor) with a diameter of 0.5 mm to form a third insulating layer with a thickness of 0.15, and a third insulated wire with an outer diameter of 0.8 was formed. Next, two insulated wires were twisted (paired-twisted) to form a second paired-twisted wire. Next, polyvinyl chloride was extruded and coated on the second paired-twisted wire to fabricate a telephone cable with an outer diameter of 4.0 mm.

[0058] A coaxial cable, a LAN cable, a telephone cable, and four intervening members of 40,000 denier were wound around such that the collective pitch P was 300 mm. Subsequently, a polyethylene terephthalate tape was wound to form a winding layer with a thickness of 0.025 mm. Finally, a Tetoron thread was aligned along the winding layer in the longitudinal direction as a tear string, and polyvinyl chloride was extruded from the die of an extruder to form an outer sheath layer with a thickness of 1.0 mm. The maximum length in the cross-section orthogonal to the longitudinal direction of the composite cable in the region surrounded by the measured winding layer was 15.3 mm. Incidentally, when the maximum length in the cross-section orthogonal to the longitudinal direction of the composite cable in the region surrounded by the winding layer was defined as D, and the collective pitch of the composite cable was defined as P, P / D was 20. In this way, the composite cable 1 was manufactured.

[0059] (2) Manufacture of Composite Cables 2 to 5 Composite cables 2 to 5 were manufactured in the same manner as the manufacture of composite cable 1, except that they were manufactured such that P / D satisfied Table 1 below.

[0060] (3) Manufacture of Composite Cables 6 to 10 Composite cables 6 to 10 were manufactured in the same manner as the manufacture of composite cable 1, except that they had no intervening members and were manufactured such that P / D satisfied Table 1 below.

[0061] 2. Evaluation (1) With each composite cable arranged linearly, the return loss (RL) and near-end crosstalk loss (NEXT) of the LAN cable were measured using general-purpose LAN cable automatic measuring equipment. For the evaluation criteria of the return loss (RL) and the near-end crosstalk loss (NEXT), the case where it passed with a margin of 2 dB or more with respect to the standard values of Category 6A of the ANSI / TIA standard was regarded as "◎", the case where it satisfied the standard was regarded as "〇", and the case where it did not satisfy the standard was regarded as "×". For the comprehensive evaluation, the case where the return loss (RL) and the near-end crosstalk loss (NEXT) were "◎" or "〇" was regarded as "○", and the case where the return loss (RL) or the near-end crosstalk loss (NEXT) was "×" was regarded as "×".

[0062] Table 1 shows the maximum length D, the bundling pitch P, and the evaluation results in a cross-section orthogonal to the longitudinal direction of the composite cable in the region surrounded by the wrapping layer.

[0063]

Table 1

[0064] 3. Evaluation (2) After each composite cable was wound around a drum and then extended, the return loss (RL) and the near-end crosstalk loss (NEXT) were measured using general-purpose LAN cable automatic measuring equipment. The evaluation criteria for the return loss (RL) and the near-end crosstalk loss (NEXT) were the same as those in Evaluation (1).

[0065] Table 2 shows the maximum length D, the bundling pitch P, and the evaluation results in a cross-section orthogonal to the longitudinal direction of the composite cable in the region surrounded by the wrapping layer.

[0066]

Table 2

[0067] As shown in Table 1 and Table 2, for composite cables 1 to 3 and 6 to 8 that satisfy 17 ≤ (P / D) < 30, both the return loss (RL) and the near-end crosstalk loss (NEXT) were good in both the linearly arranged state (Table 1) and the state after being wound around a drum and then extended (Table 2).

[0068] Also, when extended after being wound around a drum, for composite cables 1 to 3 with intervention, the return loss (RL) and the near-end crosstalk loss (NEXT) were better than those of composite cables 6 to 8 without intervention. It is considered that for composite cables 6 to 8 without intervention, tension acts in the longitudinal direction when wound around a drum, causing impedance fluctuations and affecting the insertion loss. For composite cables 1 to 3 with intervention, since the intervention functions as a buffer even when wound around a drum, it is considered that the return loss (RL) and the near-end crosstalk loss (NEXT) were good.

[0069] In the composite cables 4, 5, 9, and 10 that do not satisfy 17 ≦ (P / D) < 30, after being wound around a drum and in the extended state (Table 2), the return loss (RL) or the near-end crosstalk loss (NEXT) was poor. When P / D is less than 17, it is considered that a large amount of twist is added to the LAN cable, affecting the near-end crosstalk loss (NEXT). When P / D is 30 or more, it is considered that tension acts in the longitudinal direction of the LAN cable, causing impedance fluctuations. In the composite cables 4, 5, 9, and 10 that do not satisfy 17 ≦ (P / D) < 30, in the linearly arranged state (Table 1), the return loss (RL) or the near-end crosstalk loss (NEXT) was poor.

Industrial Applicability

[0070] The composite cable according to the present invention is useful for collectively wiring a LAN cable capable of high-speed communication and a coaxial cable for television.

Explanation of Reference Numerals

[0071] 10 Composite cable 20 LAN cable 21 Cable core 22 First winding layer 23 First shielding layer 24 First outer sheath layer 25 First twisted pair 26 Cross intervention 27 First insulated wire 28 First conductor 29 First insulating layer 30 Coaxial cable 31 Second conductor 32 Second insulating layer 33 Second shielding layer 34 Third shielding layer 35 Second outer sheath layer 40 Telephone cable 41 Second twisted pair 42 Third outer sheath layer 43 Second insulated wire 44 Third conductor 45 Third insulating layer 50 Interposition 60 Pressing winding layer 70 Outer covering layer 71 Tear string

Claims

1. A composite cable having a LAN cable, a coaxial cable, a winding layer covering the LAN cable and the coaxial cable, and an outer covering layer covering the winding layer, wherein the LAN cable and the coaxial cable are twisted together, when the maximum length in a cross section orthogonal to the length direction of the composite cable in the region surrounded by the winding layer is D and the collective pitch of the composite cable is P, the following formula (1) is satisfied: Composite cable. Formula (1) 17 ≤ (P / D) < 30

2. In the composite cable of Claim 1, the LAN cable is wound around the coaxial cable, Composite cable.

3. In the composite cable of Claim 1, further satisfying the following formula (2): Composite cable. Formula (2) 20 ≤ (P / D) ≤ 27

4. In the composite cable of Claim 1, further having an intervening member disposed in the region surrounded by the outer covering layer other than the LAN cable and the coaxial cable, Composite cable.

5. In the composite cable of Claim 1, further having a telephone cable, the LAN cable, the coaxial cable and the telephone cable are twisted together, the outer covering layer covers the LAN cable, the coaxial cable and the telephone cable, Composite cable.

6. A method for manufacturing a composite cable having a LAN cable, a coaxial cable, a winding layer covering the LAN cable and the coaxial cable, and an outer covering layer covering the winding layer, the method comprising: a step of preparing the LAN cable and the coaxial cable; a step of twisting the LAN cable and the coaxial cable so as to satisfy the following formula (1) when the maximum length in a cross section orthogonal to the length direction of the composite cable in the region surrounded by the winding layer is D and the collective pitch of the composite cable is P: Method for manufacturing a composite cable. Formula (1) 17 ≤ (P / D) < 30

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