CN206460801U - Multi-core cable - Google Patents

Abstract

Multi-core cable (1) possesses：At least two pairs wire pairs (10A~10D) that are made up of 2 electric wires (11)；At least 2 insulated electric conductors (21)；And sheath (30), it around wire pair (10A~10D) and insulated electric conductor (21) to covering.In the section vertical with length direction of cable (1), wire pair (10A~10D) is configured on same circumference, between each wire pair (10A~10D), each insulated electric conductor (21) contacts and configured with the individual wires (11) of wire pair (10A~10D).

Description

multi-core cable

technical field

The utility model relates to a multi-core cable.

Background technique

As a multi-core cable, there is known a structure in which coaxial wires and insulated wires are mixedly arranged in the cable (for example, refer to Patent Document 1).

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-006443

Utility model content

For the above-mentioned multi-core cables, it is required to realize higher-speed signal transmission, and to suppress crosstalk between electric wires included in the multi-core cables to a minimum.

The purpose of the utility model is to provide a multi-core cable, which can realize high-speed signal transmission, and can suppress the crosstalk between insulated wires and the crosstalk between differential transmission wire pairs.

The multi-core cable of the present utility model has:

At least two wire pairs consisting of 2 wires;

At least 2 insulated wires; and

a sheath covering the pair of wires and around the insulated wires,

In a section perpendicular to the length direction of the cable, the wire pairs are arranged on the same circumference,

Between each pair of electric wires, each insulated electric wire is arranged in contact with a single electric wire of the pair of electric wires.

The effect of utility model

According to the present invention, it is possible to provide a multi-core cable capable of realizing high-speed differential signal transmission and suppressing crosstalk between insulated wires and crosstalk between differential transmission wire pairs.

Description of drawings

FIG. 1 is a cross-sectional view illustrating an example of a multi-core cable according to an embodiment of the present invention.

2A is a graph showing the evaluation results of crosstalk between insulated wires constituting the multi-core cable of FIG. 1 .

2B is a graph showing the evaluation results of crosstalk between insulated wires constituting a conventional multi-core cable.

3A is a graph showing the evaluation results of crosstalk between coaxial wires constituting the multi-core cable of FIG. 1 .

3B is a graph showing the evaluation results of crosstalk between coaxial wires constituting a conventional multi-core cable.

4 is a cross-sectional view of a multi-core cable according to the conventional example shown in FIGS. 2B and 3B .

5A is a cross-sectional view showing a modified example of the multi-core cable according to the embodiment of the present invention.

5B is a cross-sectional view illustrating another modified example of the multi-core cable according to the embodiment of the present invention.

5C is a cross-sectional view showing another modified example of the multi-core cable according to the embodiment of the present invention.

detailed description

[description of embodiment of the present invention]

First, the content of embodiment of this invention is enumerated and demonstrated.

The multi-core cable involved in the embodiment of the present utility model,

(1) Possess:

At least two wire pairs consisting of 2 wires;

At least 2 insulated wires; and

a sheath covering the pair of wires and around the insulated wires,

In a section perpendicular to the length direction of the cable, the wire pairs are arranged on the same circumference,

Between each pair of electric wires, each insulated electric wire is arranged in contact with a single electric wire of the pair of electric wires.

According to this structure, one wire pair can transmit a differential transmission signal. In addition, since the insulated wires are arranged between the wire pairs arranged on the same circumference, crosstalk between the insulated wires and crosstalk between the differential transmission wire pairs can be suppressed. Furthermore, since the insulated wire is in contact with (the single wire of) the pair of wires, the pair of wires is separated from each other and the distance thereof is stable, and crosstalk can be further suppressed.

(2) It is preferable that a collective shielding layer is provided inside the sheath, and the collective shielding layer covers the pair of electric wires and the insulated electric wires.

According to this configuration, accurate high-speed signal transmission without errors due to the influence of noise can be realized. In addition, no influence of noise is exerted on external equipment.

(3) It is preferable that a pressing and winding portion is provided inside the sheath, and the pressing and winding portion covers the pair of electric wires and the insulated electric wire,

The pressing and winding part is in contact with the pair of electric wires and the insulated electric wire.

According to this structure, when a centralized shielding layer (made by braiding or winding metal thin wires) is formed on the pair of wires and insulated wires, the sheath of the pair of wires and the insulation layer of the insulated wires are not damaged, and the conductors below are damaged. exposed danger. Therefore, it is possible to prevent the exposed conductors from contacting the collective shielding layer when the cable is in use, thereby preventing sparks from being emitted.

(4) Preferably, in the cross section, an insulated electric wire different from the at least two insulated electric wires is disposed on a cable center side of the pair of electric wires.

According to this configuration, at least the pair of electric wires and the insulated electric wires between them are arranged on the circumference, and deflection can be suppressed.

(5) Preferably, the two electric wires of the electric wire pair are integrated and covered with a shielding layer.

Since noise is prevented from being applied to differential transmission signals by the shielding layer, high-speed signal transmission can be realized.

(6) The pair of electric wires is preferably a two-core parallel electric wire, and the electric wires constituting the two-core parallel electric wire are arranged in parallel along the circumferential direction of the multi-core cable.

According to this configuration, the amount of attenuation of the signal, the skew of the differential signal, and the crosstalk can be reduced.

(7) It is preferable that each of the two electric wires constituting the electric wire pair is a coaxial electric wire.

Since each line of the coaxial electric wire is shielded, noise is not applied to the differential transmission signal, and high-speed signal transmission can be realized.

(8) Preferably, the coaxial electric wires are arranged in parallel in the circumferential direction of the multi-core cable.

According to this configuration, the amount of attenuation of the signal, the skew of the differential signal, and the crosstalk can be reduced.

[the details of the embodiment of the present invention]

Next, an example of the multi-core cable according to the present invention will be described with reference to the drawings. The multi-core cable involved in the utility model has multiple wire pairs and multiple insulated wires. The wires are used to transmit differential transmission signals.

As shown in FIG. 1 , the multi-core cable 1 according to this embodiment has a plurality of coaxial wires 11 (differential wires 11 ) for high-speed signal transmission on the inner side of the outermost layer, that is, a sheath 30 (an example of a sheath). An example of a transmission wire), and a plurality of (at least 2) insulated wires 21 for low-speed signal transmission or power supply.

This multi-core cable 1 accommodates two coaxial electric wires 11 in groups so that it is suitable for differential transmission. In the multi-core cable 1 of this example, a coaxial wire pair 10A, a coaxial wire pair 10B, a coaxial wire pair 10C, and a coaxial wire pair 10D these four pairs. It is preferable that the coaxial electric wires 11 of each pair (for example, the coaxial electric wires 11 of the coaxial electric wire pair 10A) are arranged close to each other. In addition, it is preferable that the coaxial electric wires 11 constituting a pair are not twisted with each other.

Each coaxial wire 11 has a coaxial structure, that is, a central conductor 12 is covered by an insulator 13 , an outer conductor 14 is disposed on the outer periphery of the insulator 13 , and the periphery of the outer conductor 14 is covered by a sheath 15 . The coaxial wire 11 is preferably a thinner coaxial wire than AWG (American Wire Gauge) No. 28 in order to carry out high-speed digital transmission. mm ² ~0.004mm ² ).

As the central conductor 12 , for example, an annealed copper wire, a single wire of a copper alloy wire (tin plating or silver plating may be applied), or a twisted wire obtained by twisting a plurality of wires is used. In this example, as the central conductor 12 , for example, a twisted wire obtained by twisting tin-plated annealed copper wire can be used. The outer diameter of the central conductor 12 is, for example, 0.09 mm to 0.4 mm.

The insulator 13 uses, for example, a fluororesin composed of polyethylene, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polytetrafluoroethylene (PFA), or polymethylpentamethylene. The insulator 13 is formed by extrusion molding the above-mentioned resin material around the central conductor 12 . The outer diameter of the insulator 13 is, for example, 0.2 mm to 1.0 mm.

The outer conductor 14 is formed, for example, by arranging a plurality of thin metal wires wound laterally (wound in a spiral shape) around the outer periphery of the insulator 13 . An annealed copper wire and an alloy wire can be used as the thin metal wire, and plating may be performed. The outer conductor 14 can be, for example, a tin-plated annealed copper wire, which can be wound laterally at a winding angle (angle with respect to the central axis of the coaxial wire 11 ), for example, 5 degrees or more and 10 degrees or less. By setting the winding angle of the tin-plated annealed copper wire within a range of 5 degrees or more and 10 degrees or less, an increase in attenuation in the coaxial wire 11 can be sufficiently suppressed.

In addition, the sheath 15 is made by extruding and covering the outer periphery of the outer conductor 14 with fluororesin such as polyethylene, polyvinyl chloride (PVC), FEP, or winding a resin tape (such as polyethylene terephthalate). formed on the outer periphery of the outer conductor 14 . The outer diameter of the sheath 15 is, for example, 0.3 mm to 1.2 mm.

In addition, a plurality of (seven in this example) insulated electric wires 21 are accommodated in the multi-core cable 1 . In the present embodiment, some (hereinafter referred to as first insulated wires 21A) of the plurality (seven in this example) of insulated wires 21 are arranged between the coaxial wire pairs 10A to 10D, respectively. 21 A of 1st insulated electric wires are arrange|positioned in contact with the single coaxial electric wire 11 of each coaxial electric wire pair 10A-10D. In addition, a plurality of insulated wires 21 (hereinafter referred to as second insulated wires 21B) different from the first insulated wire 21A are arranged inside a circle formed by the coaxial wire pairs 10A to 10D and the first insulated wire 21A.

Both the insulated wires 21A and 21B are wires in which the conductor 22 is covered with the sheath 23 .

The conductor 22 is formed of a single wire or a twisted wire. The outer diameter of the conductor 22 is, for example, 0.15 mm to 0.8 mm. In addition, as the material of the sheath 23 covering the conductor 22, fluororesins such as polyethylene, polyvinyl chloride, and FEP are preferably used, and the outer diameter of the sheath 23 is, for example, 0.25 mm to 1.2 mm. As shown in FIG. 1 , the diameter of the first insulated wire 21A is smaller than that of the second insulated wire 21B, but the first and second insulated wires can be appropriately changed according to the outer diameter and number of coaxial wires 11 included in the multi-core cable 1 . The outer diameter and number of electric wires 21A, 21B.

In the multi-core cable 1 having four coaxial wire pairs 10A to 10D composed of two coaxial wires 11 as a set and a plurality of insulated wires 21A, 21B, the In the cross section (the cross section of FIG. 1 ), four pairs of coaxial electric wires 10A to 10D are arranged on the same circumference. The coaxial wire 11 preferably has its center conductor 12 arranged on the aforementioned circumference. It is permissible that the central conductor 12 is slightly deviated from the aforementioned circumference due to manufacturing errors and wire movement during use. In addition, the above-mentioned circle in which the coaxial electric wires 11 are arranged may be slightly elliptical. One first insulated electric wire 21A is disposed between the four coaxial electric wire pairs 10A to 10D, respectively. Each first insulated wire 21A is arranged in contact with the coaxial wires 11 of the adjacent coaxial wire pairs 10A to 10D, that is, the individual coaxial wires 11 of the respective coaxial wire pairs 10A to 10D. It is preferable that the distances from the center of the multi-core cable 1 to the respective insulated wires 21A in the cross section of FIG. 1 are the same.

A plurality of second insulated electric wires 21B are arranged inside a circle formed by the coaxial electric wire pairs 10A to 10D and the first insulated electric wire 21A. By the second insulated electric wire 21B, it is ensured that the coaxial electric wire pairs 10A to 10D and the first insulated electric wire 21A between them are arranged on the same circumference, and skew can be suppressed.

Between the coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B arranged as described above, tensile fibers 31 made of aramid fibers and filler 32 made of rayon or the like are arranged.

In the present embodiment, the coaxial wires 11 constituting the coaxial wire pairs 10A to 10D are not twisted with each other, and the four pairs of coaxial wire pairs 10A to 10D and the first and second insulated wires 21A and 21B and the tensile fibers 31 They are collectively twisted together into a helical shape and bundled (so-called layer twisting method). The reason for this is that crosstalk between the coaxial wires 11 tends to increase if the coaxial wire pair is configured by a so-called pair twisting method in which the coaxial wires are twisted in the conventional manner.

The coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B that are bundled in layers are wound with the press winding portion 41, whereby the arrangement of the coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B is not changed. will be scattered and bound.

In addition, the coaxial electric wire pairs 10A to 10D and the insulated electric wires 21A and 21B are covered with the collective shielding layer 42 via the press winding portion 41 . Furthermore, the outer peripheral side of the centralized shielding layer 42 is covered with the outer skin 30 .

As the pressing and winding portion 41 , for example, a conductive resin tape is used. The resin belt constituting the conductive resin belt is made of fluorine resin such as polytetrafluoroethylene (PTFE) resin excellent in heat resistance and abrasion resistance, and polyester resin such as polyethylene terephthalate (PET) resin. Alternatively, polyethylene (PE) or the like may be used. The conductive resin tape used as the push-and-wind portion 41 is mixed with a conductive substance such as graphite into the resin constituting the resin tape so as to be dispersed throughout the resin tape in order to have conductivity. The push-and-roll portion 41 is formed in a film shape having a predetermined thickness. The winding direction of the pressing winding portion 41 may be the same direction as the twisting direction when the coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B are collectively twisted and bundled, or may be the opposite direction. In addition, as the press winding part 41, the metal tape which consists of copper foil, aluminum foil, etc. can be used.

As described above, when the collective shielding layer 42 is formed around the coaxial wire pairs 10A to 10D and the insulated wire 21A by providing the pressing and winding portion 41, there is no sheath 15 of the coaxial wire pairs 10A to 10D and the insulated wire 21A. The sheath 23 is damaged, and the conductors 14, 22 under it are in danger of being exposed. If these conductors 14, 22 are exposed, they will come into contact with the collective shielding layer 42, which may cause sparks to be emitted during use of the multi-core cable. If the pressing and winding portion 41 is a metal tape, it is less likely to affect devices outside the multi-core cable 1 (external devices) or be less affected by noise from external devices. In addition, if the pressing winding part 41 is a conductive tape, the amount of attenuation of a signal can be reduced.

The centralized shielding layer 42 is formed by horizontally winding or braiding fine metal wires. The collective shielding layer 42 is formed by braiding tinned annealed copper wires with an outer diameter of 0.03 mm to 0.08 mm, for example. By concentrating the shielding layer 42 , noise is not applied to the signals transmitted by the coaxial wire pairs 10A to 10D, so accurate high-speed signal transmission without errors due to the influence of noise can be realized. In addition, no influence of noise is exerted on external equipment.

In addition, the sheath 30 is formed of, for example, polyvinyl chloride, polyolefin resin, or the like. The outer diameter of the sheath 30 is, for example, 2.0 mm to 6.0 mm.

When manufacturing the multi-core cable 1 of the present embodiment configured as above, first, a plurality of (three in this example) second insulated electric wires 21B are arranged in the center portion of the cross section of the cable 1 . Then, around the second insulated electric wire 21B, four pairs of coaxial electric wire pairs 10A to 10D are arranged on the same circumference. At this time, one first insulated electric wire 21A is arranged on the same circumference as the coaxial electric wire pairs 10A to 10D and between the coaxial electric wire pairs 10A to 10D so as to be in contact with the coaxial electric wire 11 . Furthermore, tensile fibers 31 or fillers 32 are arranged in gaps between the coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B. Then, the coaxial wire pairs 10A to 10D and the insulated wires 21A and 21B are intensively twisted together with the tensile fibers 31 or fillers 32 . Next, the press winding part 41 is wound around the twisted structure as described above, and the outer periphery thereof is further covered with the concentrated shielding layer 42 . Finally, the outer skin 30 is extruded on the outer periphery of the centralized shielding layer 42 .

According to the configuration of the present embodiment, differential transmission signals can be transmitted through each of the coaxial wire pairs 10A to 10D. In addition, since the insulated wire 21A is arranged between the coaxial wire pairs 10A to 10D arranged on the same circumference, crosstalk between the insulated wires 21A and crosstalk between the differential transmission wire pairs (coaxial wire pairs 10A to 10D) can be suppressed. to suppress. Furthermore, since the insulated wire 21A is in contact with the single wire 11 of the coaxial wire pairs 10A to 10D, the coaxial wire pairs 10A to 10D are separated from each other and the distance is stable, and crosstalk can be further suppressed.

(Example)

As Example 1 of the embodiment, an evaluation test of crosstalk between insulated electric wires and between pairs of coaxial electric wires was performed using the multi-core cable shown in FIG. 1 . In this evaluation test, three multi-core cables shown in FIG. 1 were prepared, and crosstalk was evaluated for each cable. The results are shown in Fig. 2A and Fig. 3A.

On the other hand, as Example 2 of the comparative example, a multi-core cable including a plurality of pairs of coaxial wires and a plurality of insulated wires, and a multi-core cable in which no insulated wire is arranged between adjacent pairs of coaxial wires was used. Cables were tested to evaluate crosstalk between insulated wires and coaxial wire pairs. In this evaluation test, three multi-core cables shown in FIG. 4 were prepared, and crosstalk was evaluated for each cable.

The results are shown in Fig. 2B and Fig. 3B. FIG. 4 is a cross-sectional view of the multi-core cable 100 according to Example 2 (comparative example) shown in FIGS. 2B and 3B . In the multi-core cable 100 , the insulated wire 121 is not arranged between the plurality of coaxial wire pairs 110A to 110D arranged on the same circumference. The insulated wire 121 is housed inside the circumference formed by the coaxial wire pairs 110A to 110D.

As shown in FIGS. 2A and 2B , in Example 1, the crosstalk between insulated electric wires is about −30 to −50 dB in the frequency band of 100 MHz to 500 MHz. On the other hand, in Example 2, the crosstalk between the insulated wires is about −20 to −40 dB in the same frequency band. As described above, it was confirmed that crosstalk between insulated electric wires can be suppressed by using the multi-core cable according to the above-mentioned embodiment.

In addition, as shown in FIGS. 3A and 3B , in Example 1, the crosstalk between the coaxial wire pairs is about −50 to −80 dB in the frequency band of 100 MHz to 500 MHz. On the other hand, in Example 2, the crosstalk between the coaxial wire pairs is about -30 to -60 dB in the same frequency band. As described above, it was confirmed that crosstalk between coaxial wire pairs can also be suppressed by using the multi-core cable according to the above-mentioned embodiment.

As mentioned above, although this invention was demonstrated in detail with reference to the specific embodiment, it is clear for those skilled in the art that various changes and corrections can be added without deviating from the mind and range of this invention. In addition, the number, position, shape, etc. of the components demonstrated above are not limited to the said embodiment, It can change to the preferable number, position, shape, etc. which implement this invention.

The number and arrangement of the coaxial wire pairs 10A to 11D and the insulated wires 21 in the multi-core cable 1 of the above-mentioned embodiment are not limited to this embodiment. At least 2 pairs of coaxial wires and at least 2 insulated wires can be accommodated in the multi-core cable.

The multi-core cables can be arranged in an arrangement relationship such as modified examples shown in FIGS. 5A to 5C , for example.

Like multi-core cables 1A and 1B shown in FIGS. 5A and 5B , two first insulated electric wires 21A may be arranged in parallel between coaxial electric wire pairs 10A to 10D. These multi-core cables 1A and 1B are used for applications where crosstalk is not a concern.

In addition, as shown in FIG. 5B , the outer diameter of the first insulated electric wire 21A arranged between the coaxial electric wire pairs 10A to 10D may be larger than that of the coaxial electric wire 11 . This large-diameter insulated wire 21A is a feeder wire for supplying current, and there is no need to consider crosstalk with other wires. Compared with other insulated wires with thicker diameters 21A, in the cross section of FIG. Misalignment is allowed to the degree on the circumference where 10A to 10D are arranged. As long as the thick-diameter insulated wire 21A is in contact with the adjacent coaxial wire 11 and the press-wound portion 41 , it can be regarded as being located on the same circumference as the coaxial wire 11 .

In addition, like the multi-core cable 1C shown in FIG. 5C , the second insulated electric wire 21B accommodated in the circle formed by the coaxial electric wire pairs 10A to 10D arranged on the same circumference may be arranged in each of the configurations. The structure between a pair of coaxial electric wires 11 of coaxial electric wire pair 10A-10D.

In addition, in the above-mentioned embodiment, the coaxial wire pairs 10A to 10D composed of a pair of coaxial wires 11 are used as the wire pairs for differential signal transmission included in the multi-core cable 1 , but the present invention is not limited thereto. example. For example, as a wire pair for differential signal transmission (high-speed signal transmission), a twisted-pair cable called STP (Shielded Twisted Pair) that twists two insulated wires and shields its surroundings can be used. A two-core parallel (twin-axial) wire that twists two insulated wires in parallel and shields their surroundings. In the case of using STPs, it is only necessary to consider that the centers of the STPs are on the same circumference in the cross section of FIG. 1 . In the case of using a double-core parallel electric wire, similar to the arrangement of the coaxial electric wire 11 shown in FIG. Parallel wires and insulated wires are twisted in layers. Thereby, it is difficult to cause positional displacement of electric wires constituting the multi-core cable, and it is possible to reduce signal attenuation, skew of differential signals, and crosstalk.

In addition, the coaxial electric wire is characterized in that there is little risk of disconnection when the cable is repeatedly bent. On the other hand, STP and twin-core parallel wires are characterized by small skew.

According to the usage environment of the cable, the wires to be used as the wire pair for differential signal transmission are determined by taking advantage of the advantages of each wire (simultaneous wire, STP, twin-core parallel wire).

This application is based on Japanese Patent Application No. 2015-113750 of the Japanese patent application for which it applied on June 4, 2015, The content is taken in here as a reference.

Explanation of labels

1: multi-core cable

10A to 10D: Coaxial wire pair (an example of a wire pair)

11: Coaxial wire (an example of a differential transmission wire)

12: Center conductor

13: insulation layer

14: Outer conductor

15: skin

21: Insulated wire (21A: first insulated wire, 21B: second insulated wire)

22: Conductor

23: skin

30: Sheath (an example of a sheath)

31: Tensile fiber

32: filler

41: Press the winding part

42: shielding layer

Claims (10)

1. A multi-core cable, which has: At least two wire pairs consisting of 2 wires; At least 2 insulated wires; and a sheath covering the pair of wires and around the insulated wires, In a section perpendicular to the length direction of the cable, the wire pairs are arranged on the same circumference, Between each pair of electric wires, each insulated electric wire is arranged in contact with a single electric wire of the pair of electric wires. 2. The multi-core cable according to claim 1, wherein, A centralized shielding layer is provided inside the sheath, and the centralized shielding layer covers the pair of wires and the insulated wires. 3. The multi-core cable according to claim 2, wherein, A pressing and winding part is provided on the inner side of the sheath, and the pressing and winding part covers the pair of electric wires and the insulated electric wires, The pressing and winding part is in contact with the pair of electric wires and the insulated electric wire. 4. The multi-core cable according to any one of claims 1 to 3, wherein, In the cross section, an insulated electric wire different from the at least two insulated electric wires is disposed on a cable center side of the pair of electric wires. 5. The multicore cable according to any one of claims 1 to 3, wherein, The two electric wires of the electric wire pair are integrated and covered with a shielding layer. 6. The multi-core cable according to claim 4, wherein, The two electric wires of the electric wire pair are integrated and covered with a shielding layer. 7. The multi-core cable according to claim 5, wherein, The pair of electric wires is a two-core parallel electric wire, and the electric wires constituting the two-core parallel electric wire are arranged in parallel along the circumferential direction of the multi-core cable. 8. The multicore cable according to any one of claims 1 to 3, wherein, The two electric wires constituting the electric wire pair are coaxial electric wires. 9. The multi-core cable according to claim 4, wherein, The two electric wires constituting the electric wire pair are coaxial electric wires. 10. The multi-core cable according to claim 8, wherein, Each of the coaxial wires is juxtaposed along the circumferential direction of the multi-core cable.