JP2015099652A - Composite cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small, or small-diameter, composite cable which can reduce the AC resistance of a power source line in the high-frequency region and noise in a signal line.SOLUTION: A composite cable includes: a signal line unit formed by twisting a plurality signal lines together; a first shield layer formed around the signal line unit; a power source line unit arranged by twisting an even number of power source lines together around the first shield layer so as to be concentric circular in the cross-sectional view; and a second shield layer formed around the power source line unit. Electric currents in mutually reverse directions flow through the even-number power source lines; the ratio d1/d2 of the outer diameter d1 of the signal line unit to the outer diameter d2 of the power source line is 1.6-3.0; the twisting pitch of the signal line unit is 25-35 times the pitch diameter; and the twisting pitch of the power source line unit is 25-35 times the pitch diameter.

Description

  The present invention relates to a composite cable including a power line (strong wire) for transporting electrical energy and a signal line (weak wire) for transmitting information by electrical communication, and in particular, a power supply cable for charging a battery of an electric vehicle. It is related with the composite cable suitable for.

  In recent years, an electromagnetic induction type non-contact power feeding system using a coil has been put into practical use as one of charging methods for an electric vehicle (EV). The non-contact power feeding system includes a power feeding device installed on the ground and a power receiving device mounted on an electric vehicle. By arranging the power supply side coil (primary coil) provided in the power supply apparatus and the power reception side coil (secondary coil) provided in the power reception side apparatus so as to face each other and magnetically coupling the power supply side coil and the power reception side coil. The power can be supplied without contact.

  As a power supply device, for example, there is a device that uses a power supply coupler incorporating a power supply coil. The power feeding coupler is connected to a power supply device installed on the ground via a power feeding cable, and is charged by being inserted into the coupler insertion port of the power receiving device. In general, the power feeding coupler includes a communication unit that transmits and receives information and the like necessary for setting charging conditions to and from the power receiving apparatus.

  A composite cable having a power transmission power line and a signal transmission signal line is used as a power feeding cable connecting the power feeding coupler and the power supply device. By using a composite cable, power can be supplied and signals can be transmitted and received with a single cable.

The composite cable is required to have a small size (small diameter), a low AC resistance of the power line, and no noise on the signal line. However, in the power feeding cable, a high-frequency large current flows through the power supply line, so that electromagnetic induction noise is generated in the signal line arranged close to the power supply line.
In order to solve this problem, an even number of power supply lines are arranged equidistantly from the cable center, that is, concentrically so that the currents flowing in opposite directions are adjacent to each other, and the signal lines are arranged inside the power supply lines. Has been proposed (see, for example, Patent Document 1 and FIG. 6A). According to the composite cable described in Patent Document 1, since the induced electromotive force generated in the signal line is canceled, electromagnetic induction noise can be reduced.

JP 2001-160322 A

When the power supply line is arranged on the outer periphery of the signal line as in the composite cable described in Patent Document 1, adjacent power supply lines are arranged in an orderly manner while ensuring a total conductor cross-sectional area necessary for flowing a large current. Is required. However, depending on the outer diameter of the signal line and the outer diameter of the power supply line, such a requirement cannot be satisfied.
That is, when the outer diameter of the power supply line is increased and the number of power supply lines is designed to be small (for example, four in FIG. 6A of Patent Document 1), the gap between the power supply lines is increased, and the power supply lines are separated. The arrangement may vary. Further, since the outer diameter of the power supply line is large, the outer diameter of the composite cable is also increased. On the other hand, when the outer diameter of the power supply line is reduced and the number of power supply lines is designed to be large, it is difficult to arrange all the power supply lines in an orderly manner on the outer periphery of the signal line.

  As described above, when the power supply lines cannot be neatly arranged on the outer periphery of the signal line, the AC resistance in the high frequency region increases, and the electromagnetic induction noise generated in the signal line also increases. Further, in the composite cable, when the periphery of the signal line is not shielded, it is considered that not less than electrostatic induction noise occurs in the signal line due to the electrostatic capacitance (floating capacitance) between the signal line and the power source line.

  An object of the present invention is to provide a small-sized (small diameter) composite cable that can reduce the AC resistance of a power supply line in a high-frequency region and reduce noise in a signal line.

The composite cable according to the present invention is a signal line unit formed by twisting a plurality of signal lines,
A first shielding layer formed around the signal line unit;
Around the first shielding layer, a power line unit in which an even number of power lines are twisted and arranged so as to be concentric in a sectional view;
A second shielding layer formed around the power line unit,
In the even number of power lines, a reverse current flows alternately,
The ratio d1 / d2 between the outer diameter d1 of the signal line unit and the outer diameter d2 of the power supply line is 1.6 to 3.0,
The twist pitch of the signal line unit is 25 to 35 times the layer core diameter,
The twist pitch of the power line unit is 25 to 35 times the core diameter.

  According to the composite cable according to the present invention, the AC resistance of the power supply line in the high frequency region can be reduced, noise in the signal line can be reduced, and further downsizing (thinning in diameter) can be achieved.

It is a figure which shows the utilization form of the composite cable which concerns on one embodiment of this invention. It is sectional drawing of the cable for electric power feeding to which this invention is applied.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a utilization form of a composite cable according to an embodiment of the present invention. In FIG. 1, the composite cable according to the present invention is applied as the power supply cable 1 of the power supply apparatus 100 that constitutes the vehicle non-contact power supply system. That is, the power supply cable 1 includes a power supply line 14 (strong electric wire) that transports electric energy and a signal line 11 (weak electric wire) that transmits information by electrical communication.

  The power supply device 100 includes a power supply device 3 installed on the ground and a power supply coupler 2 connected to the power supply device 3 via the power supply cable 1.

  The power feeding coupler 2 includes a power feeding side communication unit 21 and a power feeding side coil 22. The power feeding coupler 2 is inserted into a coupler insertion port of a power receiving device mounted on the vehicle when charging the vehicle battery. When the power feeding coupler 2 is inserted into the coupler insertion port, the power feeding side coil 22 is arranged to face the power receiving side coil (not shown). The power feeding side communication unit 21 transmits and receives information to and from the power receiving side communication unit (not shown) of the power receiving device by wireless communication. The power supply side communication unit 21 receives, for example, information permitting charging transmitted from the power reception side communication unit, and outputs the information to the power supply side control unit 31 via the signal line 11.

  The power supply device 3 includes a power supply side control unit 31, an inverter 32, an AC power source 33, an operation unit (not shown), and the like. The power feeding side control unit 31 is connected to the power feeding side coil 22 when, for example, information for instructing charging is input from an operation unit (not shown) and information for permitting charging is input from the power feeding side communication unit 21. On the other hand, the inverter 32 is controlled so as to supply power. The inverter 32 converts the commercial frequency AC voltage supplied from the AC power source 33 into a predetermined high frequency AC voltage and supplies the AC voltage to the power supply side coil 22 via the power line 14.

  When an AC voltage is applied to the power supply side coil 22, an AC current flows, and a magnetic flux that links the power reception side coil (not shown) is generated. When this magnetic flux changes, an induced current flows through the power receiving coil, and the battery mounted on the vehicle is charged.

  The power feeding cable 1 is a composite cable including a signal line 11 that performs signal transmission between the power feeding side communication unit 21 and the power feeding side control unit 31, and a power line 14 that performs power transmission between the power feeding side coil 22 and the inverter 32. . The power supply cable 1 is required to be small (small diameter), have a small AC resistance on the power supply line, and generate no noise on the signal line.

  FIG. 2 is a cross-sectional view of the power supply cable 1. As shown in FIG. 2, the power supply cable 1 includes a signal line unit 11U, an internal pressing tape 12, an internal shielding layer 13, a power line unit 14U, an external pressing tape 15, an external shielding layer 16, and the like in order from the center.

  The signal line unit 11U is an assembly in which a plurality of (for example, four) signal lines 11 are twisted together. Each signal line 11 has a configuration in which a plurality of conductor strands 11a (for example, seven copper wires) are twisted and covered with an insulator 11b (for example, cross-linked polyethylene).

  The twist pitch of the signal line unit 11U is 25 to 35 times the core diameter of the signal line unit 11U. The layer core diameter of the signal line unit 11U is the diameter of a circle C1 passing through the center of each signal line 11. For example, when the signal line unit 11U is configured by twisting four signal lines 11 having an outer diameter of 2.95 mm, the layer core diameter of the signal line unit 11U is 4.17 mm. Therefore, the twist pitch of the signal line unit 11U is set to 104 to 146 mm.

  When the twist pitch of the signal line unit 11U is smaller than 25 times the layer core diameter, the signal line 11 becomes longer, so that cost and weight increase. Further, when the twisting pitch of the signal line unit 11U is larger than 35 times the layer core diameter, the twisting is too loose and it is difficult to maintain a predetermined arrangement. That is, by making the twisting pitch of the signal line unit 11U 25 to 35 times the layer core diameter, it is possible to suppress an increase in cost and weight, and to ensure the twisted shape of the signal line unit 11U.

  An inner pressing tape 12 such as a non-woven fabric is wound around the outer periphery of the signal line unit 11U, and further an inner shielding layer 13 such as a copper tape is wound. The core material of the power feeding cable 1 is formed by the signal line unit 11U, the internal pressing tape 12, and the internal shielding layer 13. By forming the shielding layer 13 (first shielding layer) on the outer periphery of the signal line unit 11U, it is possible to effectively prevent the electrostatic induction noise from being generated in the signal line 11.

  In order to finish the core material in a circular shape, inclusions (not shown) such as jute, paper string, polypropylene string are filled between the signal lines 11. Further, a pressing tape may be wound around the inner shielding layer 13. In addition to the copper tape, a copper pipe, a braided copper wire, or the like can be applied as the internal shielding layer 13.

  The power supply line unit 14U is an aggregate in which an even number (for example, 8) of power supply lines 14 are twisted around the inner shielding layer 13 using a core material as a guide. That is, the power supply line 14 is disposed so as to be concentric in a cross-sectional view. The even number of power supply lines 14 may be arranged on the concentric circles at equal intervals, or the power supply line pairs formed by two adjacent power supply lines 14 may be arranged at equal intervals. Each power supply line 14 has a configuration in which a plurality of conductor strands 14a (for example, seven copper wires) are twisted and covered with an insulator 14b (for example, cross-linked polyethylene).

  In the power supply line unit 14 </ b> U, a current in the reverse direction flows through the adjacent power supply line 14. In FIG. 2, the power supply line 14 through which a first polarity (for example + polarity) current flows is distinguished as a power supply line 14A, and the power supply line 14 through which a second polarity (for example -polarity) current flows is distinguished as a power supply line 14B. Since currents in opposite directions flow through the power supply line 14A and the power supply line 14B, the induced electromotive force generated in the signal line 11 is canceled out, so that electromagnetic induction noise is reduced.

The power supply line unit 14U includes a plurality of pairs of power supply lines 14A and 14B (four pairs in FIG. 2) with adjacent power supply lines 14A and 14B as a pair. When the total conductor cross-sectional area of the power supply line 14 (the sum of the conductor cross-sectional areas of the individual power supply lines 14) is the same, a plurality of pairs of power supply lines 14A are formed rather than the power supply line unit 14U configured by a pair of power supply lines 14A and 14B. 14B, the AC resistance when a high-frequency current (for example, 200 kHz) flows is smaller.
Therefore, by configuring the power supply line unit 14U with a plurality of pairs of power supply lines 14A and 14B, a large current can flow when the total cross-sectional area of the conductor is constant. In other words, when the current is constant, the total cross-sectional area of the conductor can be reduced, that is, the diameter of the power supply line 14 can be reduced, and consequently the diameter of the power supply cable 1 can be reduced.

  The outer diameter d2 of the power line 14 has a ratio d1 / d2 between the outer diameter d1 of the signal line unit 11U and the outer diameter d2 of the power line 14 (hereinafter referred to as “outer diameter ratio d1 / d2”) of 1.6 to 3.0. Preferably, it is set to be 1.8 to 2.6. The outer diameter d1 of the signal line unit 11U may be adjusted as appropriate so that the outer diameter ratio d1 / d2 falls within the above range. For example, when the outer diameter d1 of the signal line unit 11U is 7.10 mm, the outer diameter d2 of the power supply line 14 is set to 2.37 to 4.44 mm.

  When the outer diameter ratio d1 / d2 between the signal line unit 11U and the power supply line 14 is smaller than 1.6, the number of the power supply lines 14 that can be arranged around the signal line unit 11U is reduced. Get smaller. Further, the gap between the power supply lines 14 becomes large, and the arrangement may be destroyed. Further, when the outer diameter ratio d1 / d2 between the signal line unit 11U and the power supply line 14 is larger than 3.0, all the power supply lines 14 necessary for flowing a large current are arranged in an orderly manner on the outer periphery of the signal line unit 11U. It becomes difficult. That is, when the outer diameter of the signal line unit 11U is excessively large or small, it is difficult to arrange the power lines 14 in a concentric manner around the signal line unit 11U.

  That is, by setting the outer diameter ratio d1 / d2 between the signal line unit 11U and the power supply line 14 to 1.6 to 3.0, preferably 1.8 to 2.6, the conductor total cross-sectional area for flowing a large current is set. The plurality of power supply lines 14 can be arranged on the outer periphery of the signal line unit 11U in an orderly manner. Further, by defining the outer diameter ratio d1 / d2 between the signal line unit 11U and the power supply line 14, the outer diameter d1 of the signal line unit 11U, the outer diameter d2 of the power supply line 14, and the like so as to have desired cable characteristics, The number of power lines 14 can be easily changed.

  In particular, the power supply line unit 14U is preferably constituted by 6 to 10 power supply lines 14, that is, constituted by 3 to 5 pairs of power supply lines 14A and 14B. As a result, the AC resistance can be reduced and the useless space is reduced, so that the cable can be made thinner.

  The twist pitch of the power line unit 14U is 25 to 35 times the core diameter of the power line unit 14U. The core diameter of the power line unit 14U is the diameter of a circle C2 that passes through the center of each power line 14. For example, when the outer diameter of the core material (signal line unit 11U + inner holding tape 12 + inner shielding layer 13) is 7.8 mm and the outer diameter of the power line 14 is 4.00 mm, the core diameter of the power line unit 14U is 11.8 mm. It becomes. Therefore, the twist pitch of the power line unit 14U is set to 490 to 686 mm.

  When the twist pitch of the power supply unit 14U is smaller than 25 times the layer core diameter, the power supply line 14 becomes longer, so that cost and weight increase. Moreover, when the twist pitch of the power supply line unit 14U is larger than 35 times the layer core diameter, the twist is too loose and it is difficult to maintain a predetermined arrangement. That is, by setting the twist pitch of the power line unit 14U to 25 to 35 times the core diameter, it is possible to suppress an increase in cost and weight, and to ensure the twist shape of the power line unit 14U.

  An external pressing tape 15 such as a non-woven fabric is wound around the outer periphery of the power line unit 14U, and an external shielding layer 16 such as a copper tape is wound around the outer periphery. The outer shielding layer 16 is grounded. A sheath 17 made of an insulator such as crosslinked polyethylene is formed on the outermost layer of the power supply cable 1. By forming the external shielding layer 16 (second shielding layer) on the outer periphery of the power line unit 14U, it is possible to prevent the electric field from leaking to the outside. Moreover, the external shielding layer 16 becomes a current flow path at the time of a short circuit accident.

  In addition, in order to finish the power feeding cable 1 in a circular shape, inclusions (not shown) such as jute, paper string, and polypropylene string are filled between the power lines 14. Further, a pressing tape may be wound around the outer shielding layer 16. In addition to the copper tape, a copper pipe, a braided copper wire, or the like can be applied as the external shielding layer 16.

As described above, the power feeding cable 1 includes a signal line unit 11U formed by twisting a plurality of signal lines 11, an internal shielding layer 13 (first shielding layer) formed around the signal line unit 11U, Around the inner shielding layer 13, a power line unit 14U in which an even number of power lines 14 are twisted and arranged so as to be concentric in a sectional view, and an outer shielding layer 16 formed around the power line unit 14U. (Second shielding layer).
In the power supply cable 1, the current in the opposite direction alternately flows through the even number of power supply lines 14 (14 </ b> A and 14 </ b> B), and the outer diameter ratio d1 / d2 between the signal line unit 11 </ b> U and the power supply line 14 is 1. 6 to 3.0, the twisting pitch of the signal line unit 11U is 25 to 35 times the layer core diameter, and the twisting pitch of the power line unit 14U is 25 to 35 times the layer core diameter.

  Thereby, the AC resistance of the power supply line 14 in the high frequency region can be reduced, and noise in the signal line 11 can be reduced. Further, the power supply cable 1 can be reduced in size (thinner diameter).

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.
For example, the power supply line of the composite cable may have a configuration in which a litz wire obtained by twisting a plurality of insulated wires (for example, seven polyurethane insulated copper wires) is covered with an insulator (for example, crosslinked polyethylene). In this case, the AC resistance in the power supply line can be reduced.
Moreover, although the composite cable which concerns on this invention is suitable as a cable for electric power feeding used for the non-contact electric power feeding system shown in embodiment, it can also be utilized with another form.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Power supply cable (composite cable)
11 Signal line 11U Signal line unit 12 Internal pressing tape 13 Internal shielding layer (first shielding layer)
14, 14A, 14B Power supply line 14U Power supply line unit 15 External pressing tape 16 External shielding layer (second shielding layer)
17 sheath

Claims (4)

A signal line unit formed by twisting a plurality of signal lines;
A first shielding layer formed around the signal line unit;
Around the first shielding layer, a power line unit in which an even number of power lines are twisted and arranged so as to be concentric in a sectional view;
A second shielding layer formed around the power line unit,
In the even number of power lines, a reverse current flows alternately,
The ratio d1 / d2 between the outer diameter d1 of the signal line unit and the outer diameter d2 of the power supply line is 1.6 to 3.0,
The twist pitch of the signal line unit is 25 to 35 times the layer core diameter,
The composite cable, wherein the twisted pitch of the power supply unit is 25 to 35 times the core diameter.   The composite cable according to claim 1, wherein a ratio d1 / d2 between an outer diameter d1 of the signal line unit and an outer diameter d2 of the power supply line is 1.8 to 2.6.   3. The composite cable according to claim 1, wherein the number of the power supply lines is 6 to 10.   The composite cable according to any one of claims 1 to 3, wherein the first shielding layer and the second shielding layer are shielding tapes wound in a spiral shape.

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