JP2023018272A - Communication cable, and method for manufacturing the same - Google Patents

Abstract

To provide a communication cable that is capable of suppressing alien crosstalk, does not require grounding, and can be efficiently manufactured.SOLUTION: A communication cable comprises: a cable core; and a shielding tape in which an isolation layer and a conductor layer are laminated. A plurality of slits 32a that segments a conductive layer 32 from one side edge part to the other side edge part are formed on the shielding tape 30, and the slits 32a are arranged at every 150 mm or more along a longitudinal direction of the shielding tape 30. The shielding tape 30 is laterally wound around the cable core, and its overlapping width is 1/3 or less the width of the shielding tape 30.SELECTED DRAWING: Figure 2

Description

The present invention relates to a communication cable and its manufacturing method.

Communication cables such as LAN (Local Area Network) cables are used to connect various devices such as between servers, between a server and a switch, and between a server and a personal computer. When connecting devices, a plurality of communication cables may be arranged close to each other. However, when multiple communication cables are placed in close proximity, the adjacent communication cables can generate noise referred to as alien crosstalk.

As a method of suppressing such alien crosstalk, a technique of placing a metal layer around the cable core of a communication cable is known. For example, conventionally, a shielding tape obtained by laminating a polyethylene terephthalate (hereinafter also referred to as "PET") film and an aluminum layer is wrapped around a cable core.

However, when the periphery of the cable core is uniformly covered with a metal layer (aluminum layer), the shielding tape is charged and tends to act as an antenna for high frequencies. When the shielding tape acts as an antenna, the electrical characteristics of the communication cable are affected, so one end or both ends of such a communication cable must be grounded. However, grounding work is very costly.

Therefore, for example, a method has been proposed in which slits are formed in the aluminum layer of the shielding tape and the shielding tape is lap-wound so that there is no portion not covered with the aluminum layer (Patent Document 1).

JP 2009-205828 A

If slits are formed in the aluminum layer of the shielding tape as in Patent Document 1, the shielding tape does not function as an antenna and grounding is not required. However, the work of overlapping the shielding tape so that there is no portion not covered with the aluminum layer is very complicated (the amount of overlapped shielding tape increases, and the taping time increases), and it is not efficient.

A main object of the present invention is to provide a communication cable that can suppress alien crosstalk, does not require grounding, and can be efficiently manufactured.

In order to solve the above problems, according to the present invention,
comprising a cable core and a shielding tape laminated with an insulating layer and a conductor layer,
A plurality of slits are formed in the shielding tape to divide the conductive layer from one side edge to the other side edge, and the slits are arranged at intervals of 150 mm or more along the longitudinal direction of the shielding tape. cage,
A communication cable is provided in which the shielding tape is laterally wound around the cable core, and the overlapping width is ⅓ or less of the width of the shielding tape.

Advantageous Effects of Invention According to the present invention, alien crosstalk can be suppressed, grounding is not required, and the shielding tape winding operation is not complicated, and efficient manufacturing is possible.

1 is a schematic cross-sectional view of a communication cable according to an embodiment of the invention; FIG. FIG. 2A is a plan view of a shielding tape of a communication cable according to one embodiment of the invention, and FIG. 2B is a side view of the shielding tape. 1 is a side view of a communication cable according to an embodiment of the invention; FIG.

The communication cable of the present invention is very useful as a so-called twisted pair cable for LAN. However, the use of the communication cable of the present invention is not limited to this use. Moreover, although one embodiment of the communication cable of the present invention will be described with reference to the drawings, the communication cable of the present invention is not limited to the embodiment.

FIG. 1 shows a longitudinal cross-sectional view of a communication cable 1 according to one embodiment of the present invention. The communication cable 1 of this embodiment is composed of a cable core 10 , a winding 20 , a shielding tape 30 and a jacket 40 .

As described above, a communication cable in which the cable core is uniformly coated with a metal layer requires grounding work even if alien crosstalk can be suppressed. On the other hand, when a slit is provided in the conductor portion of the shielding tape and the cable core is covered so that there is no portion that is not covered by the conductor portion, the work of winding the shielding tape becomes extremely complicated, resulting in a problem of low manufacturing efficiency. there were.

On the other hand, according to the study of the present inventors, the conductor layer of the shielding tape including the insulating layer and the conductor layer is provided with slits every 150 mm or more and 300 mm or less, and the slits are overlapped by 1/6 or more and 1/3 or less. It was found that the width winding not only eliminates the need for grounding work, but also sufficiently suppresses alien crosstalk. The reason is considered as follows. In the shielding tape, since the conductor layer has slits at regular intervals, the shielding tape is difficult to be charged with electricity, and the shielding tape does not function as a high-frequency antenna. On the other hand, when the shielding tape is wrapped around the cable core with the above overlapping width, the slits are arranged at substantially regular intervals in the length direction of the communication cable. At this time, since the intervals between the slits are within an appropriate range, the presence of the slits hardly affects the electrical characteristics of the communication cable. As a result, it is considered that alien crosstalk is sufficiently suppressed.

In addition, the communication cable does not need to be wrapped with a shielding tape in a complicated manner during manufacture. Therefore, there is also the advantage that the manufacturing process is less likely to become complicated.

A more specific configuration of the communication cable 1 of this embodiment will be described below.
In the communication cable 1 of the present embodiment, the cable core 10 is composed of a plurality of pairs (here, four pairs) of twisted pair wires 8 and a cross-shaped interposition 9 for separating the plurality of twisted pair wires 8 from each other. ing. Each twisted wire pair 8 has a configuration in which two insulated wires 6 each having a conductor 2 covered with an insulator 4 are twisted together. Normally, the conductor 2 is made of annealed copper wire, and the insulator 4 is made of polyethylene resin. The conductor 2 may be a single wire or a twisted wire obtained by twisting a plurality of strands. The thickness of the conductor 2 , that is, the diameter of the cross section perpendicular to the length direction is not particularly limited, and is appropriately selected according to the application and type of the communication cable 1 .

The cross interposition 9 is a member for isolating the twisted pair wires 8 from each other and separating them so that they do not come into contact with each other, and extends in the longitudinal direction of the communication cable 1 . The shape of the cross interposition 9 is not particularly limited as long as it can isolate a plurality of twisted pair wires 8 . The cross interposition 9 is made of polyethylene resin.

The cross-wiring 9 is twisted along the length direction of the communication cable 1, and the twisted pair wires 8 are also twisted while being separated from each other by the cross-wiring 9. - 特許庁

A winding 20 is installed around the cable core 10.例文帳に追加The winding 20 is a member for keeping the distance between the conductor 2 in the cable core 10 and the shielding tape 30 constant. Although the type of the roll 20 is not particularly limited, the roll 20 can be a high-density polyethylene tape in this embodiment. The winding method of the winding 20 is not particularly limited, and in this embodiment, the cable core 10 is horizontally wound along the length direction. In this specification, the term “horizontal winding” means winding a long tape in a spiral shape along the length direction of the object to be wound, and the side edge of the tape is overlapped with the previously wound tape. , means. The thickness and the number of sheets of the shimaki 20 are not particularly limited as long as they do not impair the purpose and effect of the present embodiment.

A shielding tape 30 is installed (horizontally wound) around the shimaki 20. - 特許庁The shielding tape 30 includes an insulating layer and a conductive layer. FIG. 2A shows a plan view of the shielding tape 30 before being placed around the shimaki 20, and FIG. 2B shows a side view of the shielding tape 30. As shown in FIG.
As shown in FIG. 2B, the shielding tape 30 of this embodiment has a conductive layer 32 made of aluminum laminated on an insulating layer 31 made of a PET film, and these layers are bonded together by an adhesive layer 33 . However, the types of the insulating layer 31 and the conductive layer 32 are not limited to these as long as the object and effect of this embodiment are not impaired.

Although the thickness of the conductive layer 32 in the shielding tape 30 is not particularly limited, it is preferably 10 μm or more and 50 μm or less, more preferably 20 μm or more and 40 μm or less. When the thickness of the conductive layer 32 is within this range, a sufficient shielding effect can be easily obtained. Further, when the thickness of the conductive layer 32 is within the range, the shielding tape 30 can be easily wound around the cable core 10 and the winding 20 . On the other hand, the thickness of the insulating layer 31 is not particularly limited, but is preferably 10 μm or more and 30 μm or less, more preferably 12 μm or more and 25 μm or less. When the thickness of the insulating layer 31 is within this range, the shielding tape 30 can be easily wound around the shimaki 20 or the like.

A plurality of slits 32 a are formed in the shielding tape 30 from one side edge to the other side edge of the shielding tape 30 to electrically divide the conductive layer (aluminum layer) 32 . Although the width of each slit 32a is not particularly limited, it is preferably 0.01 mm or more and 0.3 mm or less, and more preferably 0.02 mm or more and 0.25 mm or less. In this specification, the "width of the slit" refers to the length of the slit 32a in the longitudinal direction of the shielding tape 30. As shown in FIG. When the width of the slit 32a is within this range, it becomes easier to suppress charging of the conductive layer 32 . On the other hand, if the width of the conductive layer 32 is excessively wide, the electrical characteristics of the communication cable may deteriorate, such as alien crosstalk.

The shape of the slit 32a when the shielding tape 30 is viewed from above may be formed continuously from one side edge to the other side edge of the shielding tape 30, or may be linear. , may be curved. The slits 32a may be formed perpendicular to the longitudinal direction of the shielding tape 30, but are arranged so as to form an arbitrary angle (other than 180°) with the longitudinal direction of the shielding tape 30. may be

The plurality of slits 32a are arranged along the longitudinal direction of the shielding tape 30 every 150 mm or more, preferably every 150 mm or more and 300 mm or less, and the distance between the slits 32a is within the numerical range. In this specification, the “distance between slits” refers to the distance (interval) between adjacent slits 32a when the shielding tape 30 is not wrapped around the shimaki 20 or the like, and is the distance represented by L1 in FIG. 2A. is. When the plurality of slits 32a are arranged at the above distances, when the shielding tape 30 is wound around the cable core 10 or the winding 20, the intervals between the slits 32a can be maintained appropriately. Therefore, the electrical characteristics of the communication cable 1 can be improved.
As long as the distance between the slits 32a is 150 mm or more and 300 mm or less, the distance between the slits 32a does not have to be constant.

Although the width of the shielding tape 30 is not particularly limited, it is preferably 10 mm or more and 30 mm or less, more preferably 15 mm or more and 25 mm or less. If the width of the shielding tape 30 is too narrow, winding takes time. On the other hand, if the width of the shielding tape 30 is too wide, the handleability will be low.

In this embodiment, the shielding tape 30 is laterally wound along the length direction of the cable core 10 . At this time, the overlapping width of the shielding tapes 30 is preferably 1/3 or less of the width of the shielding tape 30, and more preferably 1/6 or more and 1/3 or less. As used herein, the term “overlapping width” refers to the width of overlap between the previously wound shielding tape 30 and the later wound shielding tape 30 when the shielding tape 30 is wound around the cable core 10 or the shim 20. say. The overlapping width is the length represented by L2 in FIG.

A jacket 40 is formed around the outer circumference of the shielding tape 30 . The jacket 40 is made of polyvinyl chloride resin or polyolefin resin. The jacket 40 is a so-called sheath that covers the outer circumference of the shielding tape 30 and forms the outermost layer of the communication cable 1 .

Next, a method for manufacturing the communication cable 1 will be described.

First, a single annealed copper wire is prepared as the conductor 2 . Thereafter, the polyethylene resin is extruded from the die of the extruder while conveying the conductor 2 in the longitudinal direction, and the conductor 2 is covered with the insulator 4 to form the insulated wire 6 . Subsequently, two insulated wires 6 are twisted to form a twisted wire pair 8, and four pairs of twisted wire pairs 8 are arranged along the cross-shaped interposition 9 to form a cable core 10. As shown in FIG.

After that, the cable core 10 is twisted at a predetermined pitch, and the winding 20 (high-density polyethylene tape) is laterally wound around the cable core 10 .

After that, a shielding tape 30 (aluminum foil tape) having the above-described distance between slits is prepared, and the shielding tape 30 is laterally wound around the pressing roll 20 with the above-described overlap width.
The method of forming the slits 32a is not particularly limited. For example, after laminating the conductive layer 32 on the insulating layer 31 with the adhesive layer 33 interposed therebetween, the slits 32a may be formed by laser or the like. After that, the polyvinyl chloride resin is extruded from a die of an extruder while the cable core 10 wrapped with the compression winding 20 and the shielding tape 30 is conveyed in the longitudinal direction, and the shielding tape 30 is covered with the jacket 40 . Thereby, the communication cable 1 is manufactured.

According to the present embodiment described above, it is possible to obtain the communication cable 1 that is capable of suppressing alien crosstalk and does not require grounding.

The Sustainable Development Goals (SDGs), which are international targets aiming for a sustainable and better world by 2030, were described in the "2030 Agenda for Sustainable Development" adopted at the United Nations Summit in September 2015. ), Goal 4 “Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all”.

(1) Comparative Example 1
An annealed copper wire (single wire) having an outer diameter of 0.540 mm was prepared as a conductor. Then, high-density polyethylene was prepared as an insulating resin and extruded through a die of an extruder to cover the conductor with an insulating material. After that, two insulated wires with an outer diameter of 1 mm were twisted together to form a twisted pair wire with an outer diameter of about 2 mm. Subsequently, a 5.0 mm long × 0.75 mm thick cruciform interposition was prepared, four pairs of twisted pair wires were arranged along the cruciform interposition to form a cable core, and the cable core was twisted at a pitch of 90 mm. .

After that, a press winding (high-density polyethylene tape, thickness 0.1 mm) was prepared and laterally wound around the cable core. Further, as a shielding tape, an Al/PET tape without slits (aluminum: thickness 30 μm, PET: thickness 12 μm, width 20 mm) was prepared and laterally wound around the roll. At this time, each 3.3 mm (1/6 lap) was overlapped and wound. After that, polyvinyl chloride is prepared as the outer covering resin, and this is extruded through the die of an extruder to cover the shielding tape with an outer covering (thickness of 0.4 mm) to produce a communication cable with an outer diameter of about 6.9 mm. bottom.

(2) Example 1-4
As a shielding tape, an Al/PET tape (aluminum: thickness 30 μm, PET: thickness 12 μm, width 20 mm) having slits (width 0.3 mm) perpendicular to the longitudinal direction every 150 mm or every 300 mm along the longitudinal direction prepared. Then, the shielding tape was wound sideways by overlapping each 3.3 mm (1/6 lap) or 6.7 mm (1/3 lap) around the push-wound. Other than that, a communication cable was manufactured in the same manner as in Comparative Example 1.

(3) Evaluation Alien crosstalk (PSANEXT) of each communication cable was measured with a general-purpose field tester. Table 1 shows the measurement results.

As shown in Table 1, in Example 1-4, the shielding tape was provided with a plurality of slits for dividing the conductive layer every 150 mm or more, and the shielding tape was pressed and wound so that the overlapping width was 1/3 or less. wrapped horizontally around the As a result, the alien crosstalk was substantially the same as when no slit was provided (Comparative Example 1), which was very good. In addition, the communication cable can be efficiently manufactured because the shielding tape can be wound by a general winding method (horizontal winding).

1 Communication Cable 2 Conductor 4 Insulator 6 Insulated Wire 8 Twisted Pair Wire 9 Cross Interposition 10 Cable Core 20 Winding 30 Shielding Tape 31 Insulating Layer 32 Conductive Layer 32a Slit 33 Adhesive Layer 40 Coating

Claims (4)

comprising a cable core and a shielding tape laminated with an insulating layer and a conductor layer,
A plurality of slits are formed in the shielding tape to divide the conductive layer from one side edge to the other side edge, and the slits are arranged at intervals of 150 mm or more along the longitudinal direction of the shielding tape. cage,
The communication cable, wherein the shielding tape is laterally wound around the cable core, and the overlapping width is ⅓ or less of the width of the shielding tape. In the communication cable according to claim 1,
The slits are arranged every 150 mm or more and 300 mm or less along the longitudinal direction of the shielding tape,
The communication cable, wherein the overlapping width is 1/6 or more and 1/3 or less of the width of the shielding tape. In a method for manufacturing a communication cable comprising a cable core and a shielding tape laminated with an insulating layer and a conductor layer,
In the step of preparing the shielding tape, a plurality of slits are formed to divide the conductor layer from one side edge to the other side edge, and the slits are 150 mm or more along the longitudinal direction of the shielding tape. a step of arranging each
a step of laterally winding the shielding tape around the cable core, wherein the overlapping width is ⅓ or less of the width of the shielding tape;
A method of manufacturing a communication cable. In the method for manufacturing a communication cable according to claim 3,
In the step of preparing the shielding tape, the slits are arranged every 150 mm or more and 300 mm or less along the longitudinal direction of the shielding tape,
In the step of laterally winding the shielding tape, the overlapping width is set to 1/6 or more and 1/3 or less of the width of the shielding tape.

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