JP6331902B2 - Power transmission equipment - Google Patents

Description

  The present invention relates to a power transmission device that transmits power to a power receiving device in a contactless manner.

  As disclosed in Patent Documents 1 to 7, a power transmission device that transmits and receives power without contact and a power transmission system that uses the power reception device are known. In particular, the power transmission device disclosed in Patent Document 6 includes a base material, an element mounted on the base material, a shield provided so as to cover the element, and a ferrite core disposed on the shield. And a power transmission coil mounted on the ferrite core. A flat spiral coil is employed as the power transmission coil.

  Moreover, in the power transmission device and power reception device disclosed in Patent Document 7, flat circular coils are employed for the power transmission coil and the power reception coil.

JP2013-154815A JP2013-146154A JP2013-146148A JP 2013-110822 A JP 2013-126327 A JP 2014-011852 A JP 2014-039462 A

  When a shield is disposed immediately below the circular coil and the spiral coil, an eddy current is generated in the shield due to the magnetic flux from the coil, and transmission efficiency is reduced. In particular, in the vicinity of the coil wire and in the vicinity of the end of the core, the magnetic field strength is strong, and a large eddy current is generated in the shield, which may significantly reduce transmission efficiency.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a power transmission device capable of reducing eddy currents generated in a shield by magnetic flux in a shield provided in the vicinity of a coil.

  This power transmission device is a power transmission device that transmits power to a power receiving device in a contactless manner, and houses a power transmission coil unit, an electrical device connected to the power transmission coil unit, the power transmission coil unit, and the electrical device. A housing and an electromagnetic field shield provided in the housing so as to separate the power transmission coil unit on a power transmission side and the electric device on a placement side opposite to the power transmission side.

  The power transmission coil unit includes a spiral-shaped power transmission coil and a plate-shaped ferrite core, and the electromagnetic field shield includes a main wall extending along the surface on the placement side of the ferrite core, and an end of the main wall From the first standing wall extending from the end of the first standing wall to the mounting side, the extending wall extending in a direction away from the main wall from the end of the first standing wall, and the end of the ferrite core from one end of the extending wall A second standing wall that is spaced apart and extends to the power transmission side beyond the ferrite core.

  The first standing wall extends from the end of the ferrite core toward the placement side from a position retracted toward the inside of the ferrite core.

  According to this power transmission device, at the end of the ferrite core, the electromagnetic field shield has the first standing wall, the extending wall, and the second standing wall from a position retracted from the end of the ferrite core toward the inside of the ferrite core. However, it will be arrange | positioned in the state spaced apart from the edge part of a ferrite core. Accordingly, a predetermined gap is maintained from the end of the ferrite core to the electromagnetic field shield, and the electromagnetic field shield is not disposed at a position where the strength of the magnetic flux is strong.

  According to the present invention, it is possible to provide a power transmission device that can reduce an eddy current generated in a shield by a magnetic flux in an electromagnetic field shield provided in the vicinity of a coil.

It is a figure which shows the electric power transmission system in embodiment. It is a perspective view which shows the structure of the power transmission apparatus in embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a perspective view which shows the structure of the power receiving apparatus in embodiment. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4.

  Embodiments of an example based on the present invention will be described below with reference to the drawings. In the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated. It is planned from the beginning to use the structures in the embodiments in appropriate combinations. In the drawings, the actual dimensional ratios are not described, and some ratios are described in order to facilitate understanding of the structure.

  The configuration of the power transmission device installed on the facility side (parking lot or the like) shown below can also be applied to a power reception device placed on the vehicle side. In the power transmission device, the placement surface means the facility (ground) side, and the surface side (power transmission side) means the power reception device (vehicle) side. On the other hand, in the power receiving device, the placement surface means the vehicle side, and the surface side (power receiving side) means the power transmitting device (ground) side.

  In each figure used below, the direction indicated by the arrow F in the figure indicates the forward direction and the reverse direction of the vehicle, and the direction indicated by the arrow W in the figure indicates the width direction of the vehicle.

(Power transmission system 1000)
A power transmission system 1000 that transmits power without contact will be described with reference to FIG. 1. The power transmission system 1000 includes a power receiving device 10 mounted on the electric vehicle 100 and a power transmission device 50 installed on the facility side such as a parking lot. Electric vehicle 100 includes a power receiving device 10 and a vehicle main body 105.

(Power receiving device 10)
The power receiving device 10 includes a power receiving coil unit 200 and an electric device 110 provided between the battery 150 as a power storage device that stores the power received by the power receiving coil unit 200. The power receiving coil unit 200 includes a power receiving coil 250 and a flat ferrite core 260. A spiral coil is used as the power receiving coil 250.

  The electric device 110 includes a capacitor 120, a rectifier 130, a DC / DC converter 140, and the like. In the figure, the power receiving coil 250 and the capacitor 220 are connected in series, but they may be connected in parallel.

  The vehicle main body 105 includes a battery 150 connected to the DC / DC converter 140 of the electric device 110, a power control unit 160, a motor unit 170, a communication unit 180, and the like.

  The number of turns of the power receiving coil 250 indicates a distance between the power receiving coil 250 and a power transmitting coil 450 described later, a Q value (for example, Q ≧ 100) indicating a resonance strength between the power receiving coil 250 and the power transmitting coil 450, and a degree of coupling thereof. The coupling coefficient κ is appropriately set so as to increase. The power receiving coil 250 is connected to the rectifier 130. The rectifier 130 converts the alternating current supplied from the power receiving coil unit 200 into a direct current and supplies it to the DC / DC converter 140.

(Power transmission device 50)
The power transmission device 50 includes a power transmission coil unit 400 and an electric device 300. The power transmission coil unit 400 includes a power transmission coil 450 and a flat ferrite core 460. A spiral coil is used as the power transmission coil 450.

  The electric device 300 includes a capacitor 420, a high frequency power device 310, a power transmission ECU 320, and a communication unit 322. The external AC power source 330 is detachably connected using an outlet plug 340 or the like. In the figure, the power transmission coil 450 and the capacitor 420 are connected in series, but they may be connected in parallel.

  The high frequency power device 310 converts the power received from the AC power source 330 into high frequency power, and supplies the converted high frequency power to the power transmission coil 450. The power transmission coil 450 transmits power to the power receiving coil 250 of the power receiving coil unit 200 in a non-contact manner by electromagnetic induction.

(Details of power transmission device 50)
With reference to FIG. 2 and FIG. 3, the detailed structure of the power transmission apparatus 50 in this Embodiment is demonstrated. 2 is a perspective view showing a configuration of the power transmission device 50, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  Referring to FIG. 2, the power transmission device 50 transmits power to the power receiving device 10 in a non-contact manner as described above, and supplies electricity to the power transmission coil unit 400 and is connected to an external power source. The power transmission coil unit 400 and the electric device 300 are housed in a housing 600. Therefore, power transmission device 50 in the present embodiment has a configuration in which power transmission coil unit 400 and electric device 300 are integrated. The housing 600 includes an installation wall 610, a lid member 620, and a side wall 630.

  In the present embodiment, as shown in FIG. 1, the electric device 300 includes a high-frequency power device 310, a power transmission ECU 320, and a communication unit 322. The components constituting these devices include a switching power supply and a PFC sub-device. Examples include a substrate, a fan, a DC / RF unit, a 5V / 15V power source, a 24V power source, a resonance capacitor, a heat sink, a filter inductor, an SCU, an interface, and an input control unit.

  Referring to FIG. 3, electromagnetic field shield 660 is provided in housing 600 so as to separate power transmission coil unit 400 on power transmission side S2 and electric device 300 on mounting side S1 opposite to power transmission side S2. Is arranged.

  The electromagnetic field shield 660 is made of a material such as copper so as not to allow passage of the electromagnetic field. The electromagnetic field shield 660 includes a main wall 661 extending along the surface of the placement side S1 of the ferrite core 460, a first standing wall 662 extending from the end of the main wall 661 to the placement side S1, and a first standing wall 662. An extending wall 663 extending in a direction away from the main wall 661 from the end of the first wall, and a second extending from the end of the extending wall 663 to the end 460t of the ferrite core 460 and extending to the power transmission side S2 beyond the ferrite core 460. A standing wall 664. Further, the first standing wall 662 extends from the end portion 460t of the ferrite core 460 toward the inside of the ferrite core 460 (the dimension W3 in the drawing) to the placement side S1.

  In FIG. 3, the distance W1 from the end 460t of the ferrite core 460 to the second standing wall 664 is calculated as an appropriate separation distance based on the magnetic flux emitted from the end 460t of the ferrite core 460. When the distance from the surface S1 of the ferrite core 460 to the extending wall 663 is W2, and the distance from the end 460t of the ferrite core 460 to the first standing wall 662 is W3, the distance between W2 and W3 Is preferably larger than W1.

  As described above, at the end portion 460t of the ferrite core 460, the electromagnetic field shield 660 has the first standing wall 662 and the extending wall 663 from a position retracted from the end portion 460t of the ferrite core 460 toward the inside of the ferrite core 460. And the 2nd standing wall 664 will be arrange | positioned in the state spaced apart from the edge part 460t of the ferrite core 460. FIG. As a result, a predetermined gap is maintained from the end portion 460t of the ferrite core 460 to the electromagnetic field shield 660, and the electromagnetic field shield 660 is not disposed at a position where the strength of the magnetic flux is strong.

  As a result, in the electromagnetic field shield 660 provided in the vicinity of the power transmission coil, it is possible to reduce the eddy current generated in the electromagnetic field shield by the magnetic flux, and it is possible to reduce the shield loss and decrease the transmission efficiency. It becomes.

  In the present embodiment, since the first standing wall 662 is formed to extend to a position that substantially reaches the installation wall 610, the electrical device 300 located on the placement side S1 of the ferrite core 460 is It will be in the state surrounded by the electromagnetic field shield 660. Thereby, it is also possible to ensure the stability of the operation of the electric device 300 located on the placement side S1 of the ferrite core 460.

  Further, in the power transmission device 50 in which the power transmission coil unit 400 and the electric device 300 are integrated in the housing 600, it is possible to reduce the influence of the electromagnetic field.

(Details of the power receiving device 10)
With reference to FIG. 4 and FIG. 5, a detailed configuration of power reception device 10 in the present embodiment will be described. 4 is a perspective view illustrating the configuration of the power receiving device 10, and FIG. 5 is a cross-sectional view taken along the line VV in FIG.

  With reference to FIG. 4, the power receiving device 10 includes the power receiving coil unit 200 that receives power from the power transmitting device 50 in a non-contact manner as described above, and the electric device 110 connected to the power receiving coil unit 200. The power receiving coil unit 200 and the electric device 110 are housed in the housing 600 as in the case of the power transmission device 50. Therefore, the power receiving device 10 according to the present embodiment has a configuration in which the power receiving coil unit 200 and the electric device 110 are integrated. The housing 600 includes an installation wall 610, a lid member 620, and a side wall 630.

  In the present embodiment, as shown in FIG. 1, electric device 110 includes at least a capacitor 120, a rectifier 130, and a DC / DC converter 140.

  Referring to FIG. 5, electromagnetic field shield 660 is provided in casing 600 so as to separate power receiving coil unit 200 on power receiving side S2 and electric device 110 on mounting side S1 opposite to power receiving side S2. Is arranged.

  The electromagnetic field shield 660 is made of a material such as copper so as not to allow passage of the electromagnetic field. The electromagnetic field shield 660 includes a main wall 661 extending along the surface of the placement side S1 of the ferrite core 260, a first standing wall 662 extending from the end of the main wall 661 to the placement side S1, and a first standing wall 662. An extending wall 663 extending in a direction away from the main wall 661 from the end of the first wall, and a second extending from the end of the extending wall 663 to the end 460t of the ferrite core 260 and extending to the power transmission side S2 beyond the ferrite core 260. A standing wall 664. Further, the first standing wall 662 extends from the end portion 460t of the ferrite core 260 toward the inside of the ferrite core 260 (the dimension W3 in the drawing) toward the placement side S1.

  In FIG. 5, the distance W1 from the end portion 260t of the ferrite core 260 to the second standing wall 664 is calculated as an appropriate separation distance based on the magnetic flux emitted from the end portion 260t of the ferrite core 260. When the distance from the surface S1 of the ferrite core 260 to the extending wall 663 is W2, and the distance from the end 260t of the ferrite core 260 to the first standing wall 662 is W3, the distance between W2 and W3 Is preferably larger than W1.

  Thus, at the end portion 260 t of the ferrite core 260, the electromagnetic field shield 660 has the first standing wall 662 and the extending wall 663 from a position retracted from the end portion 260 t of the ferrite core 260 toward the inside of the ferrite core 260. And the 2nd standing wall 664 will be arrange | positioned in the state spaced apart from the edge part 260t of the ferrite core 260. FIG. As a result, a predetermined gap is maintained from the end portion 260t of the ferrite core 260 to the electromagnetic field shield 660, and the electromagnetic field shield 660 is not disposed at a position where the strength of the magnetic flux is strong.

  As a result, in the electromagnetic field shield 660 provided in the vicinity of the power receiving coil, it is possible to reduce eddy currents generated in the electromagnetic field shield by the magnetic flux, reduce the shield loss, and reduce the transmission efficiency. It becomes.

  In the power receiving device 10, since the first standing wall 662 is formed to extend to a position that substantially reaches the installation wall 610, the electric device 110 located on the placement side S <b> 1 of the ferrite core 260 is It will be in the state surrounded by the electromagnetic field shield 660. Thereby, it is also possible to ensure the stability of the operation of the electric device 110 located on the placement side S1 of the ferrite core 260.

  Further, in the power receiving device 10 in which the power receiving coil unit 200 and the electric device 110 are integrated in the housing 600, the influence of the electromagnetic field can be reduced.

  Although the embodiments have been described above, the embodiments disclosed herein are illustrative and non-restrictive in every respect. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Power receiving apparatus, 50 Power transmission apparatus, 100 Electric vehicle, 105 Vehicle main body, 110,300 Electric equipment, 120,220,420 Capacitor, 130 Rectifier, 140 Converter, 150 Battery, 160 Power control unit, 170 Motor unit, 180,322 Communication unit, 200 power receiving coil unit, 250 power receiving coil, 260, 460 ferrite core, 310 high frequency power device, 330 AC power source, 400 power transmitting coil unit, 450 power transmitting coil, 600 housing, 610 installation wall, 620 lid, 630 side surface Wall, 661 Main wall, 662 First standing wall, 663 Extended wall, 664 Second standing wall, 1000 Power transmission system.

Claims (1)

A power transmission device that transmits power to a power receiving device in a contactless manner,
A power transmission coil unit;
An electrical device connected to the power transmission coil unit;
A housing for housing the power transmission coil unit and the electrical device;
An electromagnetic field shield provided in the housing, provided to separate the power transmission coil unit on a power transmission side and the electric device on a mounting side opposite to the power transmission side;
With
The power transmission coil unit is:
Including a spiral-shaped power transmission coil and a flat ferrite core,
The electromagnetic field shield is
A main wall extending along the surface on the mounting side of the ferrite core;
A first standing wall extending from the end of the main wall to the mounting side;
An extending wall extending in a direction away from the main wall from an end of the first standing wall;
A second standing wall spaced from the end of the ferrite core from one end of the extending wall and extending to the power transmission side beyond the ferrite core;
The first standing wall extends from the end of the ferrite core toward the placement side from a position retracted toward the inside of the ferrite core.
Power transmission device.

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