JP6301675B2 - Coil unit and power supply system having the same - Google Patents

Description

  The present invention relates to a coil unit that receives or supplies electric power in a non-contact manner and a power supply system having the coil unit.

  In recent years, for example, charging of a secondary battery (hereinafter simply referred to as a “power battery”) included in a plug-in hybrid vehicle (PHEV), an electric vehicle (EV), or the like is performed by using a plug connection. Wireless (non-contact) power transmission technology that does not require physical connection such as the above is used.

  For example, in the power feeding system disclosed in Patent Document 1, one of a pair of coils that electromagnetically resonate with each other is installed on the ground of the power feeding equipment, and the other is mounted on the vehicle, and the coil installed on the ground of the power feeding equipment Electric power is supplied in a non-contact manner to the coil mounted on the vehicle.

  Generally, the coil is housed in a case together with various components such as a capacitor for adjusting a resonance frequency in order to reduce the size. However, the conventional power supply system has a problem that the temperature in the case rises, the power transmission efficiency decreases due to an increase in the resistance value of the coil, and the upper limit value of the operating temperature of the capacitor is exceeded.

JP 2012-186909 A

  Then, this invention makes it a subject to provide the coil unit which can suppress the temperature rise in a case, and an electric power feeding system provided with the same.

  As a result of diligent search, the present inventors have found that an eddy current is generated in a metal such as an electrode of a capacitor housed in the case due to a magnetic field generated from the coil, thereby increasing the temperature. The present invention has been reached.

That is, the invention according to claim 1 is a coil unit comprising a coil for supplying or receiving electric power in a non-contact manner, a part at least partially made of metal, and a case for housing the coil and the part. The coil includes a core and a coil wire wound around the core in a spiral shape, the component is formed of a substrate, and the substrate includes both end portions in the central axis direction of the coil and The coil unit is characterized in that the end on the side close to the coil is cut out.

According to a second aspect of the present invention, the substrate is provided with a connection portion with a terminal fitting attached to an end portion of the electric wire, and the connection portion is provided in the vicinity of the edge portion farthest from the coil on the substrate. It consists in the coil unit according to claim 1, characterized in that was.

The invention described in claim 3 is a power feeding system having a power feeding unit provided on the ground and a power receiving unit provided on a vehicle, wherein the power receiving unit receives the power transmitted from the power feeding unit in a contactless manner. The power reception unit or the power supply unit includes the coil unit according to claim 1 .

As described above, according to the first and third aspects of the invention, since the parts are not arranged near both ends in the coil central axis direction with high magnetic flux density, eddy currents are generated in the metal of the parts. It is suppressed and temperature rise can be suppressed.

According to invention of Claim 2 , generation | occurrence | production of the eddy current in a connection part is suppressed, and a temperature rise can be suppressed.

It is a figure which shows schematic structure of the electric power feeding system of one Embodiment of this invention. It is a figure explaining arrangement | positioning of the electric power feeding unit with which the electric power feeding system of FIG. FIG. 3 is a schematic exploded perspective view of a power feeding unit and a power receiving unit in FIG. 2. FIG. 4 is a top view of the capacitor body and the coil shown in FIG. 3. It is a top view of the capacitor body and coil in a comparative example. It is a top view of the capacitor | condenser body and coil which are shown in FIG. 3 in other embodiment.

  Hereinafter, a power supply system according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram illustrating a schematic configuration of a power feeding system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the arrangement of the power supply unit and the power reception unit included in the power supply system of FIG. FIG. 3 is an exploded perspective view of the power supply unit and the power reception unit of FIG. In FIG. 3, the reference numerals of the parts constituting the power receiving unit are shown in parentheses.

  The power feeding system of this embodiment supplies electric power to the vehicle from the ground side in a non-contact manner using a magnetic field resonance method. A method other than the magnetic field resonance method may be used as long as power is transmitted by electromagnetically coupling the power feeding side and the power receiving side.

  First, a general configuration of the power feeding system 1 will be described. As shown in FIG. 1, the power feeding system 1 includes a power feeding device 20 as a power feeding unit arranged on the ground G (shown in FIG. 2) and a power receiving unit as a power receiving unit arranged in a vehicle V (shown in FIG. 2). Device 30. As shown in FIG. 2, the vehicle V includes a drive unit DRV having an engine and a motor, and a power battery BATT that supplies electric power to the motor.

  As shown in FIG. 1, the power feeding device 20 includes a high-frequency power source 21, a power feeding unit 22 as a coil unit, a matching unit 27, and a control unit 28.

  The high frequency power source 21 generates, for example, high frequency power from a commercial power source and supplies it to a power supply unit 22 described later. The high frequency power generated by the high frequency power source 21 is set to a frequency equal to the resonance frequency of the power supply unit 22 and the resonance frequency of the power receiving unit 32 described later.

  As shown in FIGS. 2 and 3, the power supply unit 22 includes a power supply side coil 23 as a coil, a power supply side capacitor body 24 as a component, and a power supply side case 25 as a box-shaped case that accommodates these. have. The power supply unit 22 is installed on the ground G as shown in FIG. The power supply unit 22 may be embedded in the ground G.

  The power feeding side coil 23 and the power feeding side capacitor body 24 are connected in series with each other to form a resonance circuit that resonates at a predetermined resonance frequency. In the present embodiment, the power supply side coil 23 and the power supply side capacitor body 24 are connected in series, but may be connected in parallel.

  The matching unit 27 is a circuit for matching the impedance between the high-frequency power source 21 and the resonance circuit including the power supply side coil 23 and the power supply side capacitor body 24.

  The control unit 28 includes a well-known microcomputer having a ROM, a RAM, and a CPU, and controls the entire power supply apparatus 20. For example, the control unit 28 performs on / off control of the high-frequency power source 21 in response to a request for power transmission.

  The power receiving device 30 includes a power receiving unit 32 as a coil unit and a rectifier 38.

  As shown in FIGS. 2 and 3, the power receiving unit 32 includes a power receiving side coil 33 as a coil, a power receiving side capacitor body 34 as a component, and a power receiving side case 35 as a box-shaped case for housing them. have. The power receiving unit 32 is attached to the lower surface of the vehicle V as shown in FIG.

  The power receiving side coil 33 and the power receiving side capacitor body 34 are connected to each other in series to form a resonance circuit that resonates at the same resonance frequency as the power supply unit 22. In the present embodiment, the power receiving side coil 33 and the power receiving side capacitor body 34 are connected in series, but may be connected in parallel.

  The rectifier 38 converts the high frequency power received by the power receiving unit 32 into DC power. For example, a load L such as a charging unit used for charging a power battery BATT mounted on the vehicle V is connected to the rectifier 38.

  Next, detailed configurations of the power feeding unit 22 and the power receiving unit 32 described in the above outline will be described with reference to FIG. As described above, each of the power feeding and power receiving units 22 and 32 includes the power feeding side, the power receiving side coils 23 and 33, the power feeding side and the power receiving side capacitor bodies 24 and 34, and the power feeding side and the power receiving side cases 25 and 35. ing. In addition, in the cases 25 and 35, in addition to the coils 23 and 33 and the capacitor bodies 24 and 34, for example, the control circuit board 9 as a board provided for performing communication between the power feeding unit 22 and the power receiving unit 32. May also be housed.

  As shown in FIG. 3, each of the power supply side and power reception side coils 23 and 33 includes a rectangular flat ferrite core 3A and a coil wire 3B made of a litz wire wound around the core 3A in a coil shape. doing.

  The cores 3 </ b> A of the power supply side and power reception side coils 23 and 33 are horizontally disposed in a power supply side and power reception side cases 25 and 35 described later. The coil wire 3 </ b> B is wound around the core 3 </ b> A with a direction perpendicular to the separation direction (the vertical direction Y <b> 1 in the present embodiment) between the power supply unit 22 and the power reception unit 32 as a central axis. As shown in FIG. 2, when the vehicle V is parked at a predetermined power feeding position, the cores 3A face each other in the vertical direction Y1 and the center of the coil wire 3B. It arrange | positions so that axial direction Y2 may become mutually parallel.

  As shown in FIG. 3, the power supply side and power reception side capacitor bodies 24 and 34 are mounted on a circuit board 4A as a rectangular flat board having a wiring pattern formed on the surface of a glass epoxy board, and the circuit board 4A, respectively. A plurality of ceramic capacitors 4B. As shown in FIG. 3, terminal fittings attached to one end of the coil wire 3 </ b> B are fastened to the circuit board 4 </ b> A by bolts B. Thereby, the coil wire 3B and the ceramic capacitor 4B are electrically connected. Further, a terminal fitting attached to one end of a lead wire 7 made of a litz wire is fastened to the circuit board 4A by a bolt B. The other end of the coil wire 3B and the other end of the lead wire 7 described above are connected to the terminal of the pair of lead wires 8 and the bolt B, which are drawn out from the inside of the power feeding side and the power receiving side cases 25 and 35 described later. It is concluded by.

  The power feeding and power receiving side cases 25 and 35 are configured to be divided into a main body 5A provided with an opening and a lid 5B covering the opening of the main body 5A. The main body 5A is made of a material that can pass magnetism from the power supply device 20, such as fiber reinforced plastic (FRP). The lid 5B is made of, for example, a material that does not transmit magnetism (becomes a magnetic shield) such as aluminum or an alloy. The power feeding side and power receiving side cases 25 and 35 are combined with the main body portion 5A and the lid portion 5B and fixed by fixing means such as a screw (not shown), so that the power feeding side, the power receiving side coils 23 and 33 and the power feeding side, A space for accommodating the power receiving side capacitor bodies 24 and 34 is formed. The power supply side case 25 is disposed on the ground G so that the lid 5B is on the ground G side and the main body 5A is on the vehicle V side. The power receiving side case 35 is attached to the lower surface of the vehicle V so that the lid portion 5B is on the lower surface side of the vehicle V and the main body portion 5A is on the ground G side.

  Next, the arrangement positions of the circuit board 4A and the control circuit board 9 constituting the capacitor bodies 24 and 34 will be described. The circuit board 4A, the control circuit board 9, and the coils 23 and 33 are arranged horizontally along the width direction Y3 of the coils 23 and 33 (that is, the direction orthogonal to both the vertical direction Y1 and the central axis direction Y2). Has been. In the present embodiment, the coils 23 and 33 are sandwiched between the circuit board 4A and the control circuit board 9 in the width direction Y3. The circuit board 4A and the control circuit board 9 are arranged so as to coincide with the center positions of the coils 23 and 33 in the central axis direction Y2, as shown in FIGS. Is not arranged.

  For example, when the two circuit boards 4A and the control circuit board 9 are arranged as described above, in general, in order to reduce the power feeding and power receiving units 22 and 32, as shown in FIG. Normally, the control circuit boards 9 are arranged along the central axis direction Y2.

  However, in the arrangement as shown in FIG. 6, the temperature of the ceramic capacitor 4B rises, and there is a possibility that the upper limit of the use temperature may be exceeded. The present inventors diligently investigated the cause of this temperature rise, and as shown by the dotted lines in FIG. 5, a magnetic flux φ from one end to the other end in the central axis direction Y1 is generated in the coils 23 and 33. .

  When the magnetic flux density around the coils 23 and 33 was examined, it was found that the vicinity of both ends in the central axis direction Y2 surrounded by a dotted line was the highest and the central position in the central axis direction Y2 was the lowest. Further, elements such as a ceramic capacitor 4B are mounted on the circuit board 4A and the control circuit board 9, and electrodes are provided on the elements. A conductive pattern is also formed on the surface. That is, part of the circuit board 4A and the control circuit board 9 is made of metal. In the comparative example shown in FIG. 5, the circuit board 4 </ b> A and the control circuit board 9 are arranged in a portion having a high magnetic flux density surrounded by a dotted line, and therefore the circuit board 4 </ b> A and the control circuit board 9 are caused by the magnetic flux φ from the coils 23 and 33. It was found that a large eddy current flowed through the metal part of this metal, which caused the temperature to rise.

  Therefore, in the present embodiment, as shown in FIGS. 3 and 4, the circuit board 4A and the control circuit board 9 are arranged so as to coincide with the center positions of the coils 23 and 33 in the central axis direction Y2, and the coil 23 Are not arranged in the vicinity of both ends in the central axis direction Y2. As a result, the circuit board 4A and the control circuit board 9 can be disposed in a place where the magnetic flux density is low, the generation of eddy currents in the metal of the circuit board 4A and the control circuit board 9 is suppressed, and the temperature rise is suppressed. it can.

  In the present embodiment, the circuit board 4A and the control circuit board 9 are arranged along the width direction Y3, thereby arranging the plurality of boards 4A, 9 in the center of the central axis direction Y2 of the coil 23 having a low magnetic flux density. The generation of eddy currents in the metals of the substrates 4A and 9 can be suppressed, and the temperature rise can be suppressed.

  Moreover, in this embodiment, in order to suppress generation | occurrence | production of an eddy current and to suppress a temperature rise, as shown to FIG. 3, FIG. 4, the circuit board 4A, the coil wire 3B (electric wire), the lead wire 7 (electric wire), The bolt fastening portion (connection portion) is provided in the vicinity of the edge portion farthest from the coils 23 and 33 on the circuit board 4A. As the distance from the coils 23 and 33 increases, the magnetic flux density decreases. That is, the bolt fastening portion can be disposed at a place where the magnetic flux density on the circuit board 4A is low. Thereby, generation | occurrence | production of the eddy current in a bolt fastening part, ie, the terminal metal fitting attached to the edge part of the coil wire 3B or the lead wire 7, and the volt | bolt B can be suppressed, and a temperature rise can be suppressed.

  According to the above-described embodiment, the circuit board 4A and the control circuit board 9 are used as components. However, the present invention is not limited to this. Any component may be used as long as at least a part is made of metal. In the embodiment described above, the control circuit board 9 may be a board having a function other than the control.

  Further, according to the above-described embodiment, the circuit board 4A and the control circuit board 9 are disposed on both sides of the coils 23 and 33 in the width direction Y3. However, the present invention is not limited to this. For example, the circuit board 4A and the control circuit board 9 may be arranged side by side in the width direction Y3 on one side of the coils 23 and 33 in the width direction Y3.

  Further, according to the above-described embodiment, the circuit board 4A and the control circuit board 9 are arranged along the width direction Y3 in the center of the central axis direction Y2 of the coils 23 and 33. However, the present invention is not limited to this. Absent. The circuit board 4A and the control circuit board 9 may be arranged side by side along the vertical direction Y1 in the center in the central axis direction Y2 of the coils 23 and 33.

  Further, according to the above-described embodiment, in the power feeding and power receiving units 22 and 32, the circuit board 4A and the control circuit board 9 are arranged so as to face the center in the central axis direction Y2 of the coils 23 and 33. It is not limited to this. Only one of the power feeding and power receiving units 22 and 32 may be used.

  Further, according to the above-described embodiment, the substrates 4A and 9 are arranged so as to coincide with the center position of the coils 23 and 33 in the central axis direction Y2 of the coils 23 and 33. is not. For example, as shown in FIG. 6, when the plurality of substrates 4A and 9 must be arranged along the central axis direction Y2 due to the space in the cases 25 and 35, the central axes of the coils 23 and 33 are arranged. Notches C may be provided in the vicinity of both ends in the direction Y2, and the substrates 4A and 9 may not be disposed in the vicinity of both ends in the central axis direction Y2 of the coils 23 and 33 having a high magnetic flux density.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Power supply system 3B Coil wire (electric wire)
4A circuit board (board)
7 Lead wire (electric wire)
9 Control circuit board (component, board)
20 Power supply device (power supply unit)
22 Power supply unit (coil unit)
23 Power supply coil (coil)
24 Power supply capacitor body (parts)
25 Power supply side case
30 Power receiving device (power receiving unit)
32 Power receiving unit (coil unit)
33 Power receiving coil (coil)
34 Power-receiving-side capacitor body (parts)
35 Power receiving case (case)
G Ground V Vehicle Y1 Vertical direction (separate direction)
Y2 Central axis direction Y3 Width direction (direction orthogonal to both the separation direction and the central axis direction)

Claims (3)

A coil unit comprising: a coil that supplies or receives power in a non-contact manner; a component that is at least partially made of metal; and a case that houses the coil and the component,
The coil has a core and a coil wire wound around the core in a spiral shape,
The component is composed of a substrate,
The coil unit is characterized in that both ends of the substrate in the central axis direction of the coil and an end close to the coil are cut out . The board is provided with a connection portion with a terminal fitting attached to the end of the electric wire,
The coil unit according to claim 1 , wherein the connection portion is provided in the vicinity of an edge portion farthest from the coil on the substrate. A power supply system having a power supply unit provided on the ground and a power reception unit provided on a vehicle, wherein the power reception unit receives power transmitted from the power supply unit in a contactless manner;
The power reception system, wherein the power reception unit or the power supply unit includes the coil unit according to claim 1 .

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