JP2014011332A - Non-contact power transmission coil unit, power receiving apparatus, vehicle, and power transmitting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission coil unit capable of improving a coupling coefficient in power transmission, power receiving apparatus, vehicle, and power transmitting apparatus including the coil unit.SOLUTION: A non-contact power transmission coil comprises: a first coil part 41 which surrounds a first winding axial line O1 and is formed by winding a coil wire so as to displace in an extending direction of the first winding axial line O1; and connected coil parts 42, 43 which are connected to the first coil part 41. The connected coil parts 42, 43 are formed to surround virtual lines O3, O4 which extend in a direction different from the extending direction of the first winding axial line O1.

Description

  The present invention relates to a coil unit for non-contact power transmission, a power receiving device, a vehicle, and a power transmission device.

  In recent years, attention has been focused on hybrid vehicles, electric vehicles, and the like that drive wheels using electric power such as a battery in consideration of the environment. Particularly in recent years, attention has been focused on wireless charging capable of charging a battery in a non-contact manner without using a plug or the like in an electric vehicle equipped with the battery as described above.

  For example, as a system for transmitting power using a unit in which a coil is wound around a core, JP 2011-49230 A, JP 2011-97671 A, JP 2010-172084 A, and JP 2011-50127 A. Gazettes are introduced.

  Furthermore, it is also introduced in International Publication No. 2011/016736 pamphlet, International Publication No. 2011/016737 pamphlet and the like.

JP 2011-49230 A JP 2011-97671 A JP 2010-172084 A JP 2011-50127 A International Publication No. 2011/016736 Pamphlet International Publication No. 2011/016737 Pamphlet

  For example, in the non-contact power feeding device described in Japanese Patent Application Laid-Open No. 2011-49230, a power transmission device and a power receiving device are included, and each of the power transmitting device and the power receiving device has a configuration in which a coil is wound around a rectangular core. It has become. The coil is wound around the center of the plate-shaped core.

  However, in such a power receiving device and a power transmitting device, a part of the magnetic flux radiated from the end of the core does not go to the counterpart core, and the coupling coefficient between the power receiving device and the power transmitting device decreases. was there.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a non-contact power transmission coil unit capable of improving the coupling coefficient during power transmission, and a power receiving device including the coil unit. An apparatus, a vehicle, and a power transmission device are provided.

  The coil unit for non-contact power transmission according to the present invention includes a first coil portion formed by winding a coil wire so as to surround the first winding axis and to be displaced in the extending direction of the first winding axis. And a connection coil part connected to the first coil part. The connection coil portion is formed so as to surround a virtual line extending in a direction different from a direction in which the first winding axis extends.

Preferably, the non-contact power transmission coil unit further includes a core. The core is
A plate-like first winding part around which the first coil part is wound is included. The first winding part includes a first main surface and a second main surface. The connection coil portion includes a main surface coil disposed on the first main surface.

  Preferably, the winding axis of the main surface coil extends in a direction orthogonal to the direction in which the first winding axis extends. Preferably, the connecting coil portion is arranged so that the imaginary line intersects the first main surface.

  Preferably, the first coil portion includes a first end portion and a second end portion. The connection coil part includes a second coil part connected to the first end part and a third coil part connected to the second end part.

  Preferably, a first winding part including the first main surface and the second main surface, a second winding part provided so as to protrude from the first main surface, and around which the second coil part is wound, And a core including a third winding portion provided so as to protrude from the first main surface and wound with the third coil portion.

  Preferably, the second winding part includes a first end surface and a first peripheral surface extending from the first end surface toward the first main surface. The third winding part includes a second end surface and a second peripheral surface extending from the second end surface toward the first main surface. The area of the first end face is larger than the area of the cross section of the first winding part in the direction perpendicular to the first winding axis. The area of the second end face is wider than the cross-sectional area of the first winding part in the direction perpendicular to the first winding axis.

  Preferably, the height of the second winding part from the first main surface and the height of the third winding part from the first main surface are substantially equal to the thickness of the first winding part. Preferably, the number of turns of the main surface coil is set to 1 turn or less. The power receiving device according to the present invention includes the non-contact power transmission coil unit.

  Preferably, the power receiving device is a power receiving device that receives power in a non-contact manner with the power transmitting device, and the non-contact power transmission coil unit is arranged so that the virtual line extends downward.

  Preferably, the power transmission device includes a power transmission unit. The power receiving device includes a power receiving unit including a coil unit for non-contact power transmission. The difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is 10% or less of the natural frequency of the power reception unit.

  Preferably, the power transmission device includes a power transmission unit. The power receiving device includes a power receiving unit including a coil unit for non-contact power transmission. The coupling coefficient between the power reception unit and the power transmission unit is 0.1 or less.

  Preferably, the power transmission device includes a power transmission unit. The power receiving device includes a power receiving unit including a coil unit for non-contact power transmission. The power reception unit is formed between at least one of a magnetic field formed between the power reception unit and the power transmission unit and oscillating at a specific frequency, and an electric field formed between the power reception unit and the power transmission unit and oscillating at a specific frequency. Receives power from the power transmission unit.

  The vehicle according to the present invention includes the power receiving device, and the coil unit for non-contact power transmission is arranged so that the virtual line is directed downward.

  The power transmission device according to the present invention includes the coil unit for non-contact power transmission. Preferably, the non-contact power transmission coil unit is arranged so that the virtual line is directed upward.

  According to the non-contact power transmission coil unit, the power receiving device including the coil unit, the vehicle, and the power transmission device according to the present invention, the coupling coefficient during power transmission can be improved.

It is a schematic diagram which shows typically the electric power transmission system, vehicle, power transmission apparatus, etc. which concern on Embodiment 1. FIG. It is an electric circuit diagram which implement | achieves non-contact electric power transmission in the electric power transmission system shown in FIG. 2 is a bottom view showing a bottom surface 25 of the vehicle 10. FIG. 2 is an exploded perspective view showing a power receiving device 11. FIG. 4 is a perspective view showing a coil unit 24. FIG. 3 is a perspective view showing a ferrite core 21. FIG. 2 is a perspective view schematically showing a secondary coil 22. FIG. It is sectional drawing in the VIII-VIII line shown in FIG. It is a perspective view which shows typically the state which made the power transmission part 56 and the power receiving part 20 face each other. It is a figure which shows the simulation model of an electric power transmission system. It is a graph which shows the gap | deviation (%) of a natural frequency, and the transmission efficiency (%) in a fixed frequency. 6 is a graph showing the relationship between the power transmission efficiency when the air gap AG is changed and the frequency f3 of the current supplied to the first coil 58 with the natural frequency f0 fixed. It is the figure which showed the relationship between the distance from an electric current source or a magnetic current source, and the intensity | strength of an electromagnetic field. 4 is a cross-sectional view schematically showing a state when electric power transmission is performed between the power receiving unit 20 and the power transmission unit 56. FIG. It is the schematic diagram which showed typically the coil unit 24A which concerns on this Embodiment 1. FIG. It is a schematic diagram which shows typically the coil unit 24B as the comparative example 1. FIG. It is a schematic diagram which shows typically the coil unit 24C as the comparative example 2. FIG. It is a schematic diagram which shows typically coil unit 24D which concerns on this Embodiment 1. FIG. It is a schematic diagram which shows the coil unit 24E as the comparative example 3. FIG. It is a figure which shows the simulation result when using two coil units 24A which concern on this Embodiment 1, and transmitted electric power between coil units 24A. It is a figure which shows the simulation result when electric power transmission is carried out between coil units 24B. It is a perspective view which shows the power receiving part 20 which concerns on this Embodiment 2. FIG. It is a perspective view which shows typically the power receiving apparatus 11 which concerns on this Embodiment 3, and the power transmission apparatus 50. FIG. FIG. 6 is a plan view showing a power receiving device 11 according to a fourth embodiment. FIG. 10 is a perspective view showing a power reception unit 20 and a power transmission unit 56 according to the fifth embodiment. FIG. 10 is a cross-sectional view showing a power reception unit 20 and a power transmission unit 56 according to a sixth embodiment. 3 is a perspective view schematically showing a coil unit 24 of a power reception unit 20. FIG.

  A power transmission system, a vehicle, a power receiving device, a power receiving coil unit, a power transmitting device, and a coil unit according to the embodiment will be described with reference to FIGS. In addition, about the same or substantially the same structure, the same code | symbol may be attached | subjected and the description may be abbreviate | omitted.

(Embodiment 1)
FIG. 1 is a schematic diagram schematically showing the power transmission system, the vehicle, the power transmission device, and the like according to the first embodiment.

  The power transmission system according to the first embodiment includes an electric vehicle 10 including a power receiving device 11 and an external power feeding device 51 including a power transmission device 50. The power receiving device 11 of the electric vehicle 10 stops at a predetermined position of the parking space 52 in which the power transmission device 50 is provided, and mainly receives power from the power transmission device 50.

  The parking space 52 is provided with a line indicating a wheel stop, a parking position, and a parking range so that the electric vehicle 10 stops at a predetermined position.

  The external power supply device 51 includes a high frequency power driver 54 connected to the AC power source 53, a control unit 55 that controls driving of the high frequency power driver 54 and the like, and a power transmission device 50 connected to the high frequency power driver 54. The power transmission device 50 includes a power transmission unit 56, and the power transmission unit 56 includes a coil unit 60 and a capacitor 59 connected to the coil unit 60. The coil unit 60 includes a ferrite core 57 and a primary coil 58 wound around the ferrite core 57. The first coil 58 is connected to the high frequency power driver 54.

  In FIG. 1, an electric vehicle 10 includes a power receiving device 11, a rectifier 13 connected to the power receiving device 11, a DC / DC converter 14 connected to the rectifier 13, and a battery connected to the DC / DC converter 14. 15, a power control unit (PCU (Power Control Unit)) 16, a motor unit 17 connected to the power control unit 16, and a vehicle ECU (a ECU for controlling driving of the DC / DC converter 14, the power control unit 16, etc. Electronic Control Unit) 12. Electric vehicle 10 according to the present embodiment is a hybrid vehicle including an engine (not shown), but includes a fuel cell vehicle as long as the vehicle is driven by a motor.

  The rectifier 13 is connected to the power receiving device 11, converts an alternating current supplied from the power receiving device 11 into a direct current, and supplies the direct current to the DC / DC converter 14.

  The DC / DC converter 14 adjusts the voltage of the direct current supplied from the rectifier 13 and supplies it to the battery 15. The DC / DC converter 14 is not an essential component and may be omitted. In this case, the DC / DC converter 14 can be substituted by providing a matching unit for matching impedance with the external power feeding device 51 between the power transmission device 50 and the high frequency power driver 54.

  The power control unit 16 includes a converter connected to the battery 15 and an inverter connected to the converter, and the converter adjusts (boosts) a direct current supplied from the battery 15 and supplies it to the inverter. The inverter converts the direct current supplied from the converter into an alternating current and supplies it to the motor unit 17.

  The motor unit 17 employs, for example, a three-phase AC motor and is driven by an AC current supplied from an inverter of the power control unit 16.

  The electric vehicle 10 may further include an engine or a fuel cell. The motor unit 17 includes a motor generator that mainly functions as a generator and a motor generator that mainly functions as an electric motor.

The power receiving device 11 includes a power receiving unit 20. The power receiving unit 20 includes a coil unit 24 and a capacitor 23 connected to the coil unit 24. The coil unit 24 includes a ferrite core 21 and a secondary coil 22 wound around the ferrite core 21. In the power receiving unit 20 as well, the capacitor 23 is not an essential component. The second coil 22 is connected to the rectifier 13.

  FIG. 2 is an electric circuit diagram for realizing contactless power transmission in the power transmission system shown in FIG. The circuit configuration shown in FIG. 2 is an example, and the configuration for realizing non-contact power transmission is not limited to the configuration in FIG.

  The secondary coil 22 forms a resonance circuit together with the capacitor 23 and receives the electric power sent from the power transmission unit 56 of the external power feeding device 51 in a non-contact manner. Although not particularly shown, a closed loop is formed by the secondary coil 22 and the capacitor 23, and a coil for taking out AC power received by the secondary coil 22 from the secondary coil 22 by electromagnetic induction and outputting it to the rectifier 13 is separately provided. May be.

  On the other hand, the primary coil 58 forms a resonance circuit together with the capacitor 59, and transmits AC power supplied from the AC power supply 53 to the power receiving unit 20 in a contactless manner. Although not particularly illustrated, a closed loop may be formed by the primary coil 58 and the capacitor 59, and a coil for supplying the AC power output from the AC power supply 53 to the primary coil 58 by electromagnetic induction may be separately provided.

  The capacitors 23 and 59 are provided to adjust the natural frequency of the resonance circuit. When a desired natural frequency is obtained using the stray capacitance of the primary coil 58 and the secondary coil 22, the capacitors 23 and 59 are provided. The capacitors 23 and 59 may be omitted.

  FIG. 3 is a bottom view showing the bottom surface 25 of the vehicle 10. Vehicle 10 includes a floor panel 26 provided at the bottom of vehicle 10. The floor panel 26 is a plate-like member that partitions the interior of the vehicle from the exterior of the vehicle.

  The bottom surface 25 of the vehicle 10 is a surface that is visible when the vehicle 10 is viewed from a position that is vertically downward with respect to the vehicle 10 in a state where the tire of the vehicle 10 is in contact with the ground. The power receiving device 11 is provided on the bottom surface 25 of the vehicle 10.

  FIG. 4 is an exploded perspective view showing the power receiving device 11. In FIG. 4, “D” indicates a downward direction D in the vertical direction. “U” indicates the upper U in the vertical direction. “L” indicates the left direction L of the vehicle. “R” indicates the vehicle right direction R. “F” indicates the vehicle front direction F. “B” indicates the vehicle rear direction B.

  The power receiving device 11 includes a power receiving unit 20 and a housing 27 that houses the power receiving unit 20 therein. The casing 27 includes a bottomed shield 28 having an opening, and a lid 29 arranged so as to close the opening of the shield 28. The shield 28 includes a top plate portion that faces the floor panel 26 and an annular peripheral wall portion that hangs downward in the vertical direction D from the top plate portion. The shield 28 is made of a metal material such as copper, for example.

  The lid portion 29 is formed so as to close the opening portion of the shield 28, and is formed of, for example, a resin material.

  FIG. 5 is a perspective view showing the coil unit 24. The ferrite core 21 includes a plate portion 30 formed in a plate shape, a protruding portion 31 provided on the plate portion 30, and a protruding portion 32 provided on the plate portion 30.

The plate portion 30 includes a main surface 33 and a main surface 34 arranged in the thickness direction. The plate part 30 is formed in a flat rectangular parallelepiped shape, and is arranged so that the longitudinal direction of the plate part 30 is the front-rear direction of the vehicle. The main surface 33 is directed downward D in the vertical direction, and the main surface 34 is directed upward U in the vertical direction.

  FIG. 6 is a perspective view showing the ferrite core 21. As shown in FIG. 6, the plate portion 30 includes side surfaces 35 and side surfaces 36 arranged in the width direction, and side surfaces 37 and side surfaces 38 arranged in the longitudinal direction.

  The protruding portion 31 is disposed along the peripheral portion on the side surface 37 side of the main surface 33. The projecting portion 32 is disposed along the peripheral portion on the side surface 38 side of the main surface 33.

  The protrusion 31 is formed in a plate shape. Projecting portion 31 includes an end surface 39 facing downward D in the vertical direction and a peripheral surface that is located around end surface 39 and hangs down toward main surface 33. The peripheral surface of the protruding portion 31 includes a side surface 35 a and a side surface 36 a arranged in the width direction of the plate portion 30, and a side surface 37 a and a side surface 38 a arranged in the longitudinal direction of the plate portion 30.

  The protrusion 32 is also formed in a plate shape. The protruding portion 32 includes an end surface 40 facing downward in the vertical direction D and a peripheral surface that is located around the end surface 40 and hangs down toward the main surface 33. The peripheral surface of the protruding portion 32 includes a side surface 35 b and a side surface 36 b arranged in the width direction of the plate portion 30, and a side surface 37 b and a side surface 38 b arranged in the longitudinal direction of the plate portion 30.

  Here, the winding axis of the portion of the secondary coil 22 wound around the plate portion 30 is defined as the winding axis O1, and the cross-sectional area of the plate portion 30 in the direction perpendicular to the winding axis O1 is defined as the cross-sectional area S1. To do. The area of the end face 39 is larger than the cross-sectional area S1, and the area of the end face 40 is larger than the cross-sectional area S1. The length L1 of the protruding portion 31 in the extending direction of the winding axis O1 is longer than the thickness T of the plate portion 30.

  The thickness T1 of the protruding portion 31 and the thickness T2 of the protruding portion 32 are substantially the same as the thickness T of the plate portion 30. Further, the thickness T1 of the protrusion 31 and the thickness T2 of the protrusion 32 are substantially the same as the diameter D1 of the secondary coil 22. The thickness T1 of the protrusion 31 is the height from the main surface 33 to the end surface 39, and the thickness T2 of the protrusion 32 is the height from the main surface 33 to the end surface 40.

  In FIG. 5, the secondary coil 22 includes a first coil 41 wound around the outer peripheral surface of the plate portion 30, a second coil 42 wound around the peripheral surface of the protruding portion 31, and a peripheral surface of the protruding portion 32. And the third coil 43 wound around.

  FIG. 7 is a perspective view schematically showing the secondary coil 22. In FIG. 7, the secondary coil 22 is connected to the first coil 41, the second coil 42 connected to the first end 44 of the first coil 41, and the second end 45 of the first coil 41. A third coil 43.

  The first coil 41 includes a plurality of unit coils 80 arranged in the extending direction of the winding axis O1. The first coil 41 surrounds the winding axis O1 as it goes from the first end 44 to the second end 45, and winds the coil wire so as to be displaced in the extending direction of the winding axis O1. Is formed.

  The second coil 42 is formed so as to surround the imaginary line O3, and the extending direction of the imaginary line O3 is different from the extending direction of the winding axis O1.

  The second coil 42 includes a tilt unit coil 81 connected to the first end 44 of the first coil 41 and a main surface coil 82 connected to the tilt unit coil 81.

  The tilt unit coil 81 is formed so as to surround the winding axis O5. The extending direction of the winding axis O5 is different from the winding axis O1. Inclined unit coil 81 includes a portion located on side surface 35 of ferrite core 21 shown in FIG. 6, a portion located on main surface 34, and a portion located on side surface 36.

  Main surface coil 82 is arranged on main surface 33. In the first embodiment, the main surface coil 82 is wound around the peripheral surface of the protruding portion 31. The main surface coil 82 is formed to surround the winding axis O6. The extending direction of the winding axis O <b> 6 is a direction orthogonal to the extending direction of the winding axis O <b> 1 and passes through the main surface 33.

  Main surface coil 82 includes a portion extending along side surface 38a of protrusion 31 shown in FIG. 6, a portion extending along side surface 35a, and a portion extending along side surface 37a. Thus, the number of turns of the second coil 42 is set to 1 turn or less. A portion extending along the end surface 37 a is drawn out and connected to the capacitor 23.

  Thus, the virtual line O3 includes the winding axis O5 and the winding axis O6, and the virtual line O3 is not limited to a straight line. In the power receiving unit 20 according to the present embodiment, the second coil 42 includes the tilt unit coil 81 and the main surface coil 82, but only the tilt unit coil 81 or only the main surface coil 82 may be used. Further, for example, the second coil 42 may include a plurality of tilt unit coils 81 and a main surface coil 82 connected to the tilt unit coils 81. Thus, the virtual line O3 may be any of a straight line, a broken line, and a curved line.

  The third coil 43 is formed so as to surround the winding axis O4, and the extending direction of the winding axis O4 is different from the extending direction of the winding axis O1.

  A tilt unit coil 83 connected to the second end 45 of the first coil 41 and a main surface coil 84 connected to the tilt unit coil 83 are included.

  The tilt unit coil 83 is formed so as to surround the winding axis O7. The direction in which the winding axis O7 extends is different from the direction in which the winding axis O1 extends.

  Inclined unit coil 83 includes a portion located on side surface 36 of plate portion 30 shown in FIG. 6, a portion located on main surface 34 of plate portion 30, a portion located on side surface 35, and a portion located on main surface 33. Including.

  Main surface coil 84 is located on main surface 33 shown in FIG. The main surface coil 84 is formed so as to surround the peripheral surface of the protruding portion 32. Main surface coil 84 includes a portion extending along side surface 36b of protrusion 32 shown in FIG. 6, a portion extending along side surface 38b, a portion extending along side surface 35b, and a portion extending along side surface 37b. Including. A portion extending along the side surface 37 b is drawn out and connected to the capacitor 23. Thus, the number of turns of the main surface coil 84 is one.

  8 is a cross-sectional view taken along line VIII-VIII shown in FIG. As shown in FIG. 8, the number of turns of main surface coil 82 and the number of turns of main surface coil 84 are one or less. For this reason, the height of the main surface coil 82 and the main surface coil 84 is substantially the diameter of the coil wire. Further, the heights of the protruding portion 31 and the protruding portion 32 also substantially coincide with the diameter of the coil wire. For this reason, it is suppressed that the thickness of the coil unit 24 becomes thick.

FIG. 9 is a perspective view schematically illustrating a state in which the power transmission unit 56 and the power reception unit 20 are opposed to each other. The power transmission unit 56 and the power reception unit 20 have substantially the same configuration. As shown in FIG. 9, the power transmission unit 56 includes a coil unit 60 and a capacitor 59. The coil unit 60 includes a primary coil 58 and a ferrite core 57, and the ferrite core 57 includes a plate portion 61 formed in a plate shape, a protruding portion 62 provided on the plate portion 61, and a plate portion 61. And a protrusion 63 provided.

  The plate portion 61 is formed in a rectangular parallelepiped plate shape, and the plate portion 61 includes a main surface 64 arranged toward the upper vertical direction U and a main surface 65 arranged toward the lower vertical direction D. including. Protruding portion 62 and protruding portion 63 are arranged on main surface 64.

  The protruding part 62 and the protruding part 63 are arranged at intervals in the longitudinal direction of the plate part 61. Protruding part 62 and protruding part 63 are arranged along the side part of main surface 64 arranged in the longitudinal direction.

  The height of the protrusion 62 is substantially equal to the cross-sectional diameter of the coil wire of the primary coil 58, and the height of the protrusion 63 is substantially equal to the cross-sectional diameter of the coil wire of the primary coil 58.

  The primary coil 58 includes a fourth coil portion 66 wound around the peripheral surface of the plate portion 61, a fifth coil portion 67 wound around the peripheral surface of the protruding portion 62, and a peripheral surface of the protruding portion 63. A rotated sixth coil portion 68. The fourth coil portion 66 includes a plurality of unit coils 70 arranged in the direction in which the winding axis O10 extends. The fourth coil portion 66 surrounds the winding axis O10 from one end to the other end, The coil wire is wound so as to be displaced in the extending direction of the winding axis O10.

  The fifth coil unit 67 includes a tilt unit coil 71 connected to the end of the fourth coil unit 66 and a main surface coil 72 connected to the tilt unit coil 71. The winding axis of the tilt unit coil 71 extends in a direction crossing the winding axis O10. The main surface coil 72 is wound around the peripheral surface of the protruding portion 62 and is located on the main surface 64 of the plate portion 61. The main surface coil 72 is formed so as to surround the periphery of the winding axis O11 extending in a direction orthogonal to the winding axis O1. The number of turns of the main surface coil 72 is one.

  The sixth coil unit 68 includes a gradient unit coil 73 connected to the end of the primary coil 58 and a main surface coil 74 connected to the gradient unit coil 73. The winding axis of the tilt unit coil 73 extends in a direction crossing the winding axis O10. The main surface coil 74 is wound around the peripheral surface of the protrusion 63 and is located on the main surface 64. The number of turns of the main surface coil 74 is approximately one.

  Thus, the number of turns of the main surface coil 72 and the number of turns of the main surface coil 74 are both 1 turn or less. Furthermore, since the height of the protrusions 62 and 63 is substantially equal to the cross-sectional diameter of the coil wire, the thickness of the coil unit 60 is suppressed from increasing.

  In addition, the area of the end surface of the protrusion part 62 is wider than the area of the cross section of the board part 61 in the direction perpendicular | vertical to winding axis O10. The area of the end face of the protruding part 63 is wider than the area of the cross section of the plate part 61 in the direction perpendicular to the winding axis O10.

  Here, the coil unit 60 and the coil unit 24 are arranged so as to face each other. The portion (surface) having the largest area among the surfaces of the coil unit 60 and the portion having the largest area among the surfaces of the coil unit 24. (Face) means facing each other.

The surface of the coil unit 60 mainly includes an upper surface, a lower surface, and four side surfaces. And in this Embodiment 1, the area of an upper surface and a lower surface is wider than another surface. Similarly, the coil unit 24 also includes an upper surface, a lower surface, and four side surfaces, and the upper surface and the lower surface have a larger area than the other surfaces.

  And in this Embodiment 1, at the time of electric power transmission, it arrange | positions so that the lower surface of the coil unit 24 and the upper surface of the coil unit 60 may face each other.

  In the power transmission system configured as described above, each operation principle when power is transmitted will be described.

  In FIG. 1, when electric power is transmitted from the external power supply device 51 to the vehicle 10, the vehicle 10 stops so that the power reception unit 20 and the power transmission unit 56 face each other as shown in FIG. 9.

  In the power transmission system according to the present embodiment, the difference between the natural frequency of power transmission unit 56 and the natural frequency of power reception unit 20 is 10% or less of the natural frequency of power reception unit 20 or power transmission unit 56. By setting the natural frequency of each power transmission unit 56 and power reception unit 20 in such a range, the power transmission efficiency can be increased. On the other hand, when the difference between the natural frequencies becomes larger than 10% of the natural frequency of the power receiving unit 20 or the power transmitting unit 56, the power transmission efficiency becomes smaller than 10%, and the adverse effects such as the charging time of the battery 15 become longer. .

  Here, the natural frequency of the power transmission unit 56 is the case where the electric circuit formed by the inductance of the first coil 58 and the capacitance of the first coil 58 freely vibrates when the capacitor 59 is not provided. Means vibration frequency. In the case where the capacitor 59 is provided, the natural frequency of the power transmission unit 56 is vibration when the electric circuit formed by the capacitance of the first coil 58 and the capacitor 59 and the inductance of the first coil 58 freely vibrates. Means frequency. In the above electric circuit, the natural frequency when the braking force and the electric resistance are zero or substantially zero is also referred to as a resonance frequency of the power transmission unit 56.

  Similarly, the natural frequency of the power receiving unit 20 is the case where the electric circuit formed by the inductance of the second coil 22 and the capacitance of the second coil 22 freely vibrates when the capacitor 23 is not provided. Means vibration frequency. In the case where the capacitor 23 is provided, the natural frequency of the power reception unit 20 is vibration when the electric circuit formed by the capacitance of the second coil 22 and the capacitor 23 and the inductance of the second coil 22 freely vibrates. Means frequency. In the electric circuit, the natural frequency when the braking force and the electric resistance are zero or substantially zero is also referred to as a resonance frequency of the power receiving unit 20.

  A simulation result obtained by analyzing the relationship between the natural frequency difference and the power transmission efficiency will be described with reference to FIGS. 10 and 11. FIG. 10 shows a simulation model of the power transmission system. The power transmission system includes a power transmission device 190 and a power reception device 191, and the power transmission device 190 includes a coil 192 (electromagnetic induction coil) and a power transmission unit 193. The power transmission unit 193 includes a coil 194 (primary coil) and a capacitor 195 provided in the coil 194.

  The power receiving device 191 includes a power receiving unit 196 and a coil 197 (electromagnetic induction coil). Power receiving unit 196 includes a coil 199 and a capacitor 198 connected to this coil 199 (secondary coil).

The inductance of the coil 194 is defined as an inductance Lt, and the capacitance of the capacitor 195 is defined as a capacitance C1. The inductance of the coil 199 is defined as an inductance Lr, and the capacitance of the capacitor 198 is defined as a capacitance C2. When each parameter is set in this way, the natural frequency f1 of the power transmission unit 193 is represented by the following equation (1), and the natural frequency f2 of the power reception unit 196 is represented by the following equation (2).

f1 = 1 / {2π (Lt × C1) ^1/2 } (1)
f2 = 1 / {2π (Lr × C2) ^1/2 } (2)
Here, when the inductance Lr and the capacitances C1 and C2 are fixed and only the inductance Lt is changed, the relationship between the deviation of the natural frequency of the power transmission unit 193 and the power reception unit 196 and the power transmission efficiency is shown in FIG. . In this simulation, the relative positional relationship between the coil 194 and the coil 199 is fixed, and the frequency of the current supplied to the power transmission unit 193 is constant.

  In the graph shown in FIG. 11, the horizontal axis indicates the deviation (%) of the natural frequency, and the vertical axis indicates the transmission efficiency (%) at a constant frequency. The deviation (%) in the natural frequency is expressed by the following equation (3).

(Deviation of natural frequency) = {(f1-f2) / f2} × 100 (%) (3)
As is clear from FIG. 11, when the deviation (%) in natural frequency is ± 0%, the power transmission efficiency is close to 100%. When the deviation (%) in natural frequency is ± 5%, the power transmission efficiency is 40%. When the deviation (%) of the natural frequency is ± 10%, the power transmission efficiency is 10%. When the deviation (%) in natural frequency is ± 15%, the power transmission efficiency is 5%. That is, by setting the natural frequency of each power transmission unit and the power reception unit so that the absolute value (difference in natural frequency) of the deviation (%) of the natural frequency is within a range of 10% or less of the natural frequency of the power reception unit 196. It can be seen that the power transmission efficiency can be increased. Furthermore, the power transmission efficiency can be further improved by setting the natural frequency of each power transmitting unit and the power receiving unit so that the absolute value of the deviation (%) of the natural frequency is 5% or less of the natural frequency of the power receiving unit 196. I understand that I can do it. As simulation software, electromagnetic field analysis software (JMAG (registered trademark): manufactured by JSOL Corporation) is employed.

Next, the operation of the power transmission system according to the present embodiment will be described.
In FIG. 1, the first coil 58 is supplied with AC power from the high frequency power driver 54. At this time, electric power is supplied so that the frequency of the alternating current flowing through the first coil 58 becomes a specific frequency.

  When a current having a specific frequency flows through the first coil 58, an electromagnetic field that vibrates at the specific frequency is formed around the first coil 58.

  The second coil 22 is disposed within a predetermined range from the first coil 58, and the second coil 22 receives electric power from an electromagnetic field formed around the first coil 58.

  In the present embodiment, so-called helical coils are employed for the second coil 22 and the first coil 58. For this reason, a magnetic field and an electric field that vibrate at a specific frequency are formed around the first coil 58, and the second coil 22 mainly receives electric power from the magnetic field.

Here, a magnetic field having a specific frequency formed around the first coil 58 will be described. The “magnetic field of a specific frequency” typically has a relationship with the power transmission efficiency and the frequency of the current supplied to the first coil 58. First, the relationship between the power transmission efficiency and the frequency of the current supplied to the first coil 58 will be described. The power transmission efficiency when power is transmitted from the first coil 58 to the second coil 22 varies depending on various factors such as the distance between the first coil 58 and the second coil 22. For example, the natural frequency (resonance frequency) of the power transmission unit 56 and the power reception unit 20 is the natural frequency f0, the frequency of the current supplied to the first coil 58 is the frequency f3, and the frequency between the second coil 22 and the first coil 58 is Let the air gap be the air gap AG.

  FIG. 12 is a graph showing the relationship between the power transmission efficiency and the frequency f3 of the current supplied to the first coil 58 when the air gap AG is changed with the natural frequency f0 fixed.

  In the graph shown in FIG. 12, the horizontal axis indicates the frequency f3 of the current supplied to the first coil 58, and the vertical axis indicates the power transmission efficiency (%). The efficiency curve L1 schematically shows the relationship between the power transmission efficiency when the air gap AG is small and the frequency f3 of the current supplied to the first coil 58. As shown in the efficiency curve L1, when the air gap AG is small, the peak of power transmission efficiency occurs at frequencies f4 and f5 (f4 <f5). When the air gap AG is increased, the two peaks when the power transmission efficiency is increased change so as to approach each other. As shown in the efficiency curve L2, when the air gap AG is larger than the predetermined distance, the peak of the power transmission efficiency is one, and the power transmission efficiency is obtained when the frequency of the current supplied to the first coil 58 is the frequency f6. Becomes a peak. When the air gap AG is further increased from the state of the efficiency curve L2, the peak of power transmission efficiency is reduced as shown by the efficiency curve L3.

  For example, the following first method can be considered as a method for improving the power transmission efficiency. As a first method, the frequency of the current supplied to the first coil 58 shown in FIG. 1 is constant, and the capacitances of the capacitor 59 and the capacitor 23 are changed according to the air gap AG. A method of changing the characteristic of the power transmission efficiency with the unit 20 can be mentioned. Specifically, the capacitances of the capacitor 59 and the capacitor 23 are adjusted so that the power transmission efficiency reaches a peak in a state where the frequency of the current supplied to the first coil 58 is constant. In this method, the frequency of the current flowing through the first coil 58 and the second coil 22 is constant regardless of the size of the air gap AG. As a method for changing the characteristics of the power transmission efficiency, a method using a matching device provided between the power transmission device 50 and the high-frequency power driver 54, a method using the converter 14, or the like can be adopted. .

  The second method is a method of adjusting the frequency of the current supplied to the first coil 58 based on the size of the air gap AG. For example, in FIG. 11, when the power transmission characteristic is the efficiency curve L <b> 1, a current having a frequency f <b> 4 or a frequency f <b> 5 is supplied to the first coil 58. When the frequency characteristic becomes the efficiency curves L 2 and L 3, a current having a frequency f 6 is supplied to the first coil 58. In this case, the frequency of the current flowing through the first coil 58 and the second coil 22 is changed in accordance with the size of the air gap AG.

  In the first method, the frequency of the current flowing through the first coil 58 is a fixed constant frequency, and in the second method, the frequency flowing through the first coil 58 is a frequency that changes as appropriate according to the air gap AG. . The first coil 58 is supplied with a current having a specific frequency set so as to increase the power transmission efficiency by the first method, the second method, or the like. When a current having a specific frequency flows through the first coil 58, a magnetic field (electromagnetic field) that vibrates at a specific frequency is formed around the first coil 58. The power reception unit 20 receives power from the power transmission unit 56 through a magnetic field that is formed between the power reception unit 20 and the power transmission unit 56 and vibrates at a specific frequency. Therefore, the “magnetic field oscillating at a specific frequency” is not necessarily a magnetic field having a fixed frequency. In the above example, focusing on the air gap AG, the frequency of the current supplied to the first coil 58 is set, but the power transmission efficiency is the horizontal of the first coil 58 and the second coil 22. It varies depending on other factors such as a shift in direction, and the frequency of the current supplied to the first coil 58 may be adjusted based on the other factors.

  In addition, although the example which employ | adopted the helical coil as a resonance coil was demonstrated, when antennas, such as a meander line, are employ | adopted as a resonance coil, the electric current of a specific frequency flows into the 1st coil 58, and a specific frequency. Is formed around the first coil 58. And electric power transmission is performed between the power transmission part 56 and the power receiving part 20 through this electric field.

  In the power transmission system according to the present embodiment, the efficiency of power transmission and power reception is improved by using a near field (evanescent field) in which the “electrostatic magnetic field” of the electromagnetic field is dominant. FIG. 13 is a diagram showing the relationship between the distance from the current source or the magnetic current source and the strength of the electromagnetic field. Referring to FIG. 13, the electromagnetic field is composed of three components. The curve k1 is a component that is inversely proportional to the distance from the wave source, and is referred to as a “radiated electromagnetic field”. A curve k2 is a component inversely proportional to the square of the distance from the wave source, and is referred to as an “induction electromagnetic field”. The curve k3 is a component inversely proportional to the cube of the distance from the wave source, and is referred to as an “electrostatic magnetic field”. When the wavelength of the electromagnetic field is “λ”, the distance at which the strengths of the “radiant electromagnetic field”, the “induction electromagnetic field”, and the “electrostatic magnetic field” are approximately equal can be expressed as λ / 2π.

  The “electrostatic magnetic field” is a region where the intensity of electromagnetic waves suddenly decreases with the distance from the wave source. In the power transmission system according to the present embodiment, this “electrostatic magnetic field” is a dominant near field (evanescent field). ) Is used to transmit energy (electric power). That is, in the near field where the “electrostatic magnetic field” is dominant, by resonating the power transmitting unit 56 and the power receiving unit 20 (for example, a pair of LC resonance coils) having adjacent natural frequencies, the power receiving unit 56 and the other power receiving unit are resonated. Energy (electric power) is transmitted to 20. Since this "electrostatic magnetic field" does not propagate energy far away, the resonance method transmits power with less energy loss than electromagnetic waves that transmit energy (electric power) by "radiant electromagnetic field" that propagates energy far away. be able to.

  Thus, in this power transmission system, power is transmitted in a non-contact manner between the power transmission unit and the power reception unit by causing the power transmission unit and the power reception unit to resonate (resonate) with each other by an electromagnetic field. Such an electromagnetic field formed between the power reception unit and the power transmission unit may be referred to as a near-field resonance (resonance) coupling field, for example. And coupling coefficient (kappa) between a power transmission part and a power receiving part is about 0.3 or less, for example, Preferably, it is 0.1 or less. Naturally, a range of about 0.1 to 0.3 for the coupling coefficient κ can also be employed. The coupling coefficient κ is not limited to such a value, and may take various values that improve power transmission.

  For example, “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, “magnetic field resonance (resonance) coupling”, “near-field resonance” may be used as the coupling between the power transmitting unit 56 and the power receiving unit 20 in the power transmission of the present embodiment. (Resonant) coupling "," Electromagnetic field (electromagnetic field) resonant coupling "or" Electric field (electric field) resonant coupling ".

  The “electromagnetic field (electromagnetic field) resonance coupling” means a coupling including any of “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, and “electric field (electric field) resonance coupling”.

  Since the coil-shaped antenna is employed for the first coil 58 of the power transmission unit 56 and the second coil 22 of the power reception unit 20 described in this specification, the power transmission unit 56 and the power reception unit 20 are mainly used. The power transmission unit 56 and the power reception unit 20 are “magnetic resonance coupled” or “magnetic field (magnetic field) resonance coupled”.

  For example, an antenna such as a meander line may be employed as the first coils 58 and 22. In this case, the power transmission unit 56 and the power reception unit 20 are mainly coupled by an electric field. At this time, the power transmission unit 56 and the power reception unit 20 are “electric field (electric field) resonance coupled”.

  Next, the case where power transmission is performed between the power reception unit 20 and the power transmission unit 56 according to the present embodiment will be described using FIG. 14 and the like. FIG. 14 is a cross-sectional view schematically showing a state in which power transmission is performed between the power reception unit 20 and the power transmission unit 56.

  When power transmission is performed, the main surface 33 of the power reception unit 20 and the main surface 64 of the power transmission unit 56 face each other. The protruding part 32 of the power receiving unit 20 and the protruding part 62 of the power transmitting unit 56 face each other, and the protruding part 31 of the power receiving unit 20 and the protruding part 63 of the power transmitting unit 56 face each other.

  Here, the facing surface of the coil unit 60 where the coil unit 60 faces the coil unit 24 in a state where the coil unit 24 and the coil unit 60 face each other will be described. The facing surface of the coil unit 60 means a portion of the surface of the coil unit 60 that is located closer to the coil unit 24 than the winding axis O10. In the example illustrated in FIG. 14, the facing surface of the coil unit 60 mainly includes a main surface 64, an end surface of the protruding portion 62, and an end surface of the protruding portion 63.

  Similarly, in the state where the coil unit 24 and the coil unit 60 face each other, the opposed surface of the coil unit 24 where the coil unit 24 faces the coil unit 60 is more than the winding axis O1 in the surface of the coil unit 24. The part located in the coil unit 60 side is meant.

  In the example shown in FIG. 14, the facing surface of the coil unit 24 mainly includes the main surface 33, the end surface of the protruding portion 32, and the end surface of the protruding portion 31.

  Thus, when a current of a predetermined frequency flows through the primary coil 58 in a state where the coil unit 24 and the coil unit 60 face each other, for example, a magnetic flux flows in the fourth coil portion 66 (plate portion 61), Magnetic flux flows toward the fifth coil portion 67.

  The winding axis O10 of the fourth coil portion 66 extends in the horizontal direction. The winding axis of the tilt unit coil 71 bends from the winding axis O1, and the winding axis O11 of the fifth coil portion 67 extends upward in the vertical direction U. In this manner, the winding axis O11 extends toward the power receiving unit 20 in a state where the power receiving unit 20 (coil unit 24) and the power transmission unit 56 (coil unit 60) face each other. For this reason, the magnetic flux is also bent along the winding axis of the fifth coil portion 67, and the magnetic flux is radiated vertically upward U from the end face of the protruding portion 62.

  In particular, since the main surface coil 72 is wound around the peripheral surface of the protrusion 62, the magnetic flux is well radiated upward U in the vertical direction.

  While the winding axis O1 of the first coil 41 of the power receiving unit 20 is arranged to extend in the horizontal direction, the winding axis O4 of the third coil 43 also extends downward D from the winding axis O1. Is bent like so. That is, the winding axis O4 extends toward the power transmission unit 56 (coil unit 60) in a state where the power reception unit 20 (coil unit 24) and the power transmission unit 56 (coil unit 60) face each other. The winding axis O <b> 4 extends so as to penetrate the opposing surface of the coil unit 60. Specifically, the winding axis O <b> 4 penetrates the end surface of the protruding portion 62 among the opposing surfaces of the coil unit 60. For this reason, the magnetic flux enters the secondary coil 22 from the third coil 43 well. The magnetic flux bends along the winding axis O <b> 4 of the third coil 43 and enters the first coil 41.

In particular, since the main surface coil 84 is wound around the peripheral surface of the protruding portion 32, the magnetic flux enters the third coil 43 well from the protruding portion 32. Then, the magnetic flux that has entered from the third coil 43 bends along the winding axis O <b> 4 and enters the first coil 41. Since the first coil 41 is wound around the plate portion 30, the magnetic resistance is small and the magnetic flux flows toward the second coil 42 in a favorable manner.

  The imaginary line O3 of the second coil 42 is also bent from the winding axis O1 and extends toward the lower side D in the vertical direction. The imaginary line O <b> 3 extends so as to penetrate the end surface of the protruding portion 63 among the opposing surfaces of the coil unit 60. For this reason, the magnetic flux that has entered the second coil 42 from the first coil 41 also bends along the imaginary line O <b> 3 and travels downward in the vertical direction D from the second coil 42.

  At this time, since the main surface coil 82 is wound around the peripheral surface of the protruding portion 31, the magnetic flux is radiated from the end surface of the protruding portion 31 well upward U in the vertical direction.

  The winding axis O12 of the sixth coil portion 68 extends from the winding axis O10 so as to be directed upward U in the vertical direction. That is, the winding axis O12 also extends in a direction penetrating the end surface of the protrusion 31. For this reason, the magnetic flux which came out of the 2nd coil 42 enters into the 6th coil part 68 favorably. Then, it bends along the winding axis O <b> 12 and enters the fourth coil portion 66.

  The flow of magnetic flux is not limited to the flow as described above, and naturally, the flow of magnetic flux is switched in the reverse direction over time. In this way, the magnetic path 85 is formed. The magnetic path 85 includes the fourth coil portion 66 (plate portion 61), the inclined unit coil 71, the main surface coil 72 (projecting portion 62), the air gap, and the main surface coil 84 (projecting portion 32). Inside, the gradient unit coil 83, the first coil 41 (plate portion 30), the gradient unit coil 81, the main surface coil 82 (projecting portion 31), the air gap, and the main surface coil 74 ( It passes through the protrusion 63) and the tilt unit coil 73.

  As described above, the fifth coil portion 67 and the third coil 43 guide the magnetic flux so that the magnetic flux can easily pass through each other.

  As described above, according to the power reception unit 20 including the coil unit 24 and the power transmission unit 56 including the coil unit 60, a magnetic path can be formed satisfactorily, and between the power reception unit 20 and the power transmission unit 56 is achieved. The coupling coefficient can be increased. Thereby, electric power transmission can be performed highly efficiently.

  Further, since the magnetic path is suppressed from expanding between the second coil 42 and the sixth coil portion 68 and between the third coil 43 and the fifth coil portion 67, it is formed around the vehicle 10. The electromagnetic field strength that is generated can be kept low.

  The coil units 24 and 60 are reduced in thickness, and the power receiving unit 20 and the power transmission unit 56 can be reduced in size.

  Moreover, the area of the end surface 39 of the protrusion part 31 is larger than the cross-sectional area S1, and the area of the end surface 40 of the protrusion part 32 is also larger than the cross-sectional area S1. For this reason, even if the power reception unit 20 and the power transmission unit 56 are relatively displaced, high power transmission efficiency can be maintained. In particular, since the area of the end surfaces of the projecting portions 62 and 63 is wider than the cross-sectional area of the plate portion 61 also in the power transmission unit 56, it is possible to further improve the misalignment characteristics.

  In addition, in the example shown in the said FIG. 1 to FIG. 14, although the example in which the protrusion part 31 and the protrusion part 32 were provided was demonstrated, the protrusion part 31 and the protrusion part 32 are not an essential structure. In the example shown in FIGS. 1 to 14, the example in which both the second coil 42 and the third coil 43 are provided has been described. However, only one of the second coil 42 and the third coil 43 is provided. You may make it provide.

  Next, the coil unit according to the present embodiment and the coil unit according to the comparative example will be described with reference to FIGS. 15 to 19 and Table 1 below.

FIG. 15 is a schematic diagram schematically showing the coil unit 24A according to the first embodiment. FIG. 16 is a schematic diagram schematically showing a coil unit 24B as the first comparative example. FIG.
7 is a schematic diagram schematically showing a coil unit 24C as the comparative example 2. FIG. FIG. 18 is a schematic diagram schematically showing the coil unit 24D according to the first embodiment. FIG. 19 is a schematic diagram showing a coil unit 24E as Comparative Example 3.

  In Table 1, “coil shape”, “number of turns”, and “core shape” of each of the coil units 24A to 24E are described. As a simulation result when electric power is transmitted between two coil units of the same type, “Ls (inductance)”, “Lo (invalid inductance)”, and “coupling coefficient” are described.

  As shown in Table 1, the coil unit 24B has the highest coupling coefficient among the coil units 24B, 24C, and 24E of the comparative example. It can be seen that the coupling coefficient of the coil unit 24A according to the first embodiment is improved compared to the coil units 24B, 24C, and 24E. Furthermore, it can be seen that the coupling coefficient of the coil unit 24D according to the first embodiment is improved as compared with the coil units 24B, 24C, and 24E.

  Thus, it can be seen that the coupling coefficient can be improved by using the coil unit according to the first embodiment.

  In particular, as shown in the coil unit 24A, it can be seen that the provision of the protrusion 31 and the protrusion 32 can improve the coupling coefficient.

  FIG. 20 is a diagram illustrating a simulation result when power is transmitted between the coil units 24A using the two coil units 24A according to the first embodiment. In FIG. 20, a magnetic field distribution and a magnetic field vector are shown.

  FIG. 21 is a diagram illustrating a simulation result when power is transmitted between the coil units 24B. FIG. 21 also shows the magnetic field distribution and the magnetic field vector.

(Embodiment 2)
A coil unit and the like according to the second embodiment will be described with reference to FIG. FIG. 22 is a perspective view showing power reception unit 20 according to the second embodiment. In the example shown in FIG. 22, the lid of the housing is omitted.

  As illustrated in FIG. 22, the power receiving device 11 includes a coil unit 24, a capacitor 23, and a housing 27 that houses the coil unit 24 and the capacitor 23. The rectifier 13 is also accommodated in the housing 27.

  The coil unit 24 includes a ferrite core 21 and a secondary coil 22 wound around the ferrite core 21. Ferrite core 21 includes a plate portion 30 formed in a plate shape including main surface 33 and main surface 34, a magnetic pole portion 46 provided on main surface 33, and a magnetic pole portion 47 provided on main surface 33. .

  The magnetic pole part 46 and the magnetic pole part 47 are arranged at an interval in the extending direction of the winding axis O1. If the width of the plate portion 30 in the direction perpendicular to the winding axis O1 is the width L10 and the length of the magnetic pole portion 46 in the direction perpendicular to the winding axis O1 is the length L11, the length L11 is larger than the width L10. long.

A central portion of the plate portion 30 in a direction perpendicular to the winding axis O1 is defined as a central portion P1, and a central portion of the magnetic pole portion 46 in a direction perpendicular to the winding axis O1 is defined as a central portion P2. Similarly, the central part of the magnetic pole part 47 in the direction perpendicular to the winding axis O1 is defined as a central part P3. In the direction perpendicular to the winding axis O1, the central portion P2 and the central portion P3 are displaced from the central portion P1 in the same direction. Thus, the ferrite core 21 is formed to be asymmetric with respect to the winding axis O1.

  A recess 48 and a recess 49 are formed by the plate portion 30, the magnetic pole portion 46 and the magnetic pole portion 47. The concave portion 48 is formed at a position adjacent to one side with respect to the plate portion 30, and the concave portion 49 is formed at a position adjacent to the other side with respect to the plate portion 30. The accommodation volume of the recess 48 is larger than the accommodation volume of the recess 49, and the rectifier 13 and the capacitor 23 are accommodated in the recess 48.

  The magnetic pole portion 46 includes an end surface 75 and a peripheral surface extending from the end surface 75 toward the main surface 33. The magnetic pole portion 47 includes an end surface 76 and a peripheral surface extending from the end surface 76 toward the main surface 33.

  The area of the end surface 75 and the area of the end surface 76 are larger than the area of the cross section of the plate part 30 in the direction perpendicular to the winding axis O1. The power receiving unit 20 is mounted on the bottom surface of the vehicle 10 such that the end surface 75 and the end surface 76 are arranged in the vertical direction downward D.

  The secondary coil 22 is connected to the first coil 41 wound around the plate portion 30, the second coil 42 connected to one end of the first coil 41, and the other end of the first coil 41. Third coil 43 formed.

  The second coil 42 includes a main surface coil 82 wound around the peripheral surface of the magnetic pole portion 46, and the third coil 43 includes a main surface coil 84 wound around the peripheral surface of the magnetic pole portion 47. Also in the power reception unit 20 formed in this way, the virtual line O3 of the main surface coil 82 extends toward the lower side D in the vertical direction.

  Also in the power receiving unit 20 configured as described above, the second coil 42 and the third coil 43 are provided, so that the magnetic flux can be guided toward the power transmitting units arranged to face each other.

  Since the end face 75 of the magnetic pole part 46 and the end face 76 of the magnetic pole part 47 are directed to the power transmission part arranged to face each other, the magnetic path is well formed.

  Since the long magnetic pole part 46 and the magnetic pole part 47 are provided, even if the power reception unit 20 and the power transmission unit are displaced in the vehicle left direction L or the vehicle right direction R, the power reception unit 20 and the power reception unit It is easy to form a magnetic path between them, and high power transmission efficiency can be maintained.

  Moreover, by forming the ferrite core 21 asymmetrically, the rectifier 13 and the capacitor 23 can be accommodated in the recess 48, and the power receiving unit 20 can be made compact.

  In addition, although the power receiving apparatus 11 was mainly demonstrated, naturally, the structure of the power receiving apparatus 11 can also be applied to the power transmitting apparatus 50.

(Embodiment 3)
FIG. 23 is a perspective view schematically showing power reception device 11 and power transmission device 50 according to the third embodiment. In FIG. 23, the capacitors 23 and 59, the casing 27, and the casing that houses the power transmission unit 56 are not shown.

  In FIG. 23, the power receiving apparatus 11 includes a plurality of coil units 86A to 86D arranged in an array. In the example shown in FIG. 23, the coil unit 86A and the coil unit 86B are arranged in the front-rear direction of the vehicle 10, and the coil unit 86B and the coil unit 86D are also arranged in the width direction of the vehicle 10.

  The coil unit 86A is arranged on the vehicle rear direction B side from the coil unit 86B, and the coil unit 86C is arranged on the vehicle rear direction B side from the coil unit 86D.

  The coil unit 86A includes a secondary coil 22A and a ferrite core 21A around which the secondary coil 22A is wound. The ferrite core 21A includes a plate portion 30A and a protruding portion 32A formed on the lower surface of the plate portion 30A. The protruding portion 32A is arranged along the side portion on the vehicle rear direction B side in the lower surface of the plate portion 30A. In the coil unit 86A, no protrusion is provided on the side of the lower surface of the plate 30A on the vehicle front direction F side. The secondary coil 22A includes a first coil 41A wound around the peripheral surface of the plate portion 30A and a third coil 43A wound around the peripheral surface of the protruding portion 32A.

  The coil unit 86C is formed in the same manner as the coil unit 86A. The coil unit 86C includes a secondary coil 22C and a ferrite core 21C around which the secondary coil 22C is wound. The ferrite core 21C includes a plate portion 30C and a protruding portion 32C formed on the lower surface of the plate portion 30A. The protruding portion 32C is disposed along the side portion on the vehicle rear direction B side of the vehicle 10 in the lower surface of the plate portion 30C. Note that the coil unit 86C is also provided with no protruding portion on the side on the vehicle front direction F side in the lower surface of the plate portion 30C.

  The secondary coil 22C includes a first coil 41C wound around the peripheral surface of the plate portion 30C and a third coil 43C wound around the peripheral surface of the protruding portion 32C.

  The coil unit 86B includes a secondary coil 22B and a ferrite core 21B around which the secondary coil 22B is wound. The ferrite core 21B includes a plate portion 30B and a protruding portion 31B formed on the lower surface of the plate portion 30B. The protruding portion 31B is disposed along the side portion on the vehicle front direction F side of the vehicle 10 in the lower surface of the plate portion 30B. Note that the coil unit 86B is not provided with a protruding portion on a side portion on the vehicle rear direction B side in the lower surface of the plate portion 30B.

  The secondary coil 22B includes a first coil 41B wound around the peripheral surface of the plate portion 30B and a second coil 42B wound around the peripheral surface of the protruding portion 31B.

  The coil unit 86D includes a secondary coil 22D and a ferrite core 21D around which the secondary coil 22D is wound. The ferrite core 21D includes a plate portion 30D and a protruding portion 31D formed on the lower surface of the plate portion 30D. The protrusion 31D is disposed along the side of the vehicle 10 in the vehicle front direction F side in the lower surface of the plate 30D. Note that the coil unit 86D is not provided with a protruding portion on the side portion on the vehicle rear direction B side in the lower surface of the plate portion 30D.

  The secondary coil 22D includes a first coil 41D wound around the peripheral surface of the plate portion 30D and a second coil 42D wound around the peripheral surface of the protruding portion 31D.

  Thus, the power receiving unit 20 is formed by a plurality of coil units 86A to 86D.

  When power is transmitted between the power receiving unit 20 formed in this way and the power transmission unit 56, the protrusions 32A and 32C of the coil units 86A and 86C are disposed above the protrusion 62 of the power transmission unit 56. The Further, the protruding portions 31 </ b> B and 31 </ b> D are disposed above the protruding portion 63 of the power transmission unit 56.

A current having a specific frequency flows through the primary coil 58.
At this time, since the projecting portion 32A and the projecting portion 32C are arranged to face the projecting portion 62, the magnetic flux is satisfactorily transferred between the coil units 86A and 86C and the power transmitting unit 56.

  Since the coil unit 86A and the coil unit 86B are close to each other, the magnetic flux is satisfactorily exchanged between the coil unit 86A and the coil unit 86B.

  Since the coil unit 86C and the coil unit 86D are close to each other, the magnetic flux is favorably transferred between the coil unit 86C and the coil unit 86D.

  Since the protrusions 31B and 31D are opposed to the protrusion 63, magnetic flux is exchanged favorably between the protrusions 31B and 31D and between the protrusions 63.

  Thus, the magnetic path 85A passing through the coil unit 86A, the coil unit 86B, and the power transmission unit 56, and the magnetic path 85B passing through the coil unit 86C, the coil unit 86D, and the power transmission unit 56 are formed.

  As described above, the magnetic paths 85 </ b> A and 85 </ b> B are formed, so that power can be transmitted favorably between the power receiving unit 20 and the power transmitting unit 56.

(Embodiment 4)
The power receiving device 11 according to the present embodiment will be described with reference to FIG. FIG. 24 is a plan view showing power reception device 11 according to the fourth embodiment. In FIG. 24, capacitor 23 and the housing are not shown.

  Also in the example shown in FIG. 24, the power reception unit 20 includes a ferrite core 21 and a secondary coil 22 wound around the peripheral surface of the ferrite core 21.

  The ferrite core 21 is formed in a long plate shape in the extending direction of the winding axis O1. The secondary coil 22 includes a first coil 41 wound around the peripheral surface of the ferrite core 21, a second coil 42 connected to one end of the first coil 41, and the other end of the first coil 41. 3rd coil 43 connected to the part.

  The first coil 41 surrounds the winding axis O1 and is formed by winding the coil wire so as to be displaced in the extending direction of the winding axis O1 from one end to the other end. Has been.

  The second coil 42 and the third coil 43 are disposed on the lower surface of the ferrite core 21. The second coil 42 and the third coil 43 are arranged with a space therebetween. The second coil 42 surrounds the imaginary line O3 and is formed by winding the coil wire so that the winding diameter decreases from the end connected to the first coil 41 toward the other end. Has been.

  The third coil 43 surrounds the winding axis O4 and is formed so that the winding diameter decreases from the end connected to the first coil 41 toward the other end.

  Thus, the thickness of the second coil 42 and the third coil 43 is substantially the same as the cross-sectional diameter of the coil wire. For this reason, also in the example shown to this figure coil unit 24, thickness reduction of the unit is achieved.

In the power receiving unit 20 according to the fourth embodiment, the direction of the magnetic flux formed by the third coil 43 and the direction of the magnetic flux formed by the second coil 42 when a current flows through the secondary coil 22. It is the opposite direction.

  According to the power receiving unit 20 formed as described above, the magnetic flux transmitted from the power transmitting unit 56 disposed below can be satisfactorily received by one of the second coil 42 or the third coil 43. Then, the magnetic flux received by the second coil 42 or the third coil 43 passes through the ferrite core 21 and the first coil 41, toward the power transmission unit 56 from the other side of the second coil 42 and the third coil 43. It is sent out well.

  Thus, according to the power receiving unit 20 according to the fourth embodiment, it is possible to perform power transmission with the power transmission unit 56 satisfactorily. Although the power receiving unit 20 has been described in the fourth embodiment, it goes without saying that the configuration of the power receiving unit 20 can be applied to the power transmitting unit 56.

(Embodiment 5)
The power reception unit 20 and the power transmission unit 56 according to the fifth embodiment will be described with reference to FIG. As shown in FIG. 25, the power reception unit 20 includes a ferrite core 21 and a secondary coil 22 wound around the ferrite core 21.

  The ferrite core 21 is formed in a + shape. The ferrite core 21 includes a plurality of core pieces 95A to 95D and protrusions 96A to 96D formed on the lower surfaces of the core pieces 95A to 95D. One end portions of the core pieces 95A to 95D are connected to each other, and the other end portions of the core pieces 95A to 95D are free ends.

  The protrusions 96A to 96D are arranged along the free end side of the lower surface of each of the core pieces 95A to 95D.

  The secondary coil 22 is wound around the coil 89A wound around the core piece 95A, the coil 89B wound around the core piece 95B, the coil 89C wound around the core piece 95C, and the core piece 95D. Coil 89D.

  The coils 89A, 89B, 89C, and 89D are the first coils 41A, 41B, 41C, and 41D wound around the peripheral surfaces of the core pieces 95A, 95B, 95C, and 95D, and the protrusions 96A, 96B, 96C, and 96D. And second coils 88A, 88B, 88C, 88D wound around the surface.

  The first coil 41B and the first coil 41D are formed by winding a coil wire so as to surround the winding axis O1a and to be displaced in a direction in which the winding axis O1a extends from one end side to the other end. Has been.

  The first coil 41A and the first coil 41C are formed by winding a coil wire so as to surround the winding axis O1b and to be displaced in the extending direction of the winding axis O1b from the one end side toward the other end side. ing.

  The second coils 88A, 88B, 88C, and 88D are each formed by winding a coil wire so as to surround the periphery of a winding shaft that extends upward U in the vertical direction.

The power transmission unit 56 includes a ferrite core 57 and a primary coil 58 wound around the ferrite core 57. The ferrite core 57 is also formed in a + shape. The ferrite core 57 includes a plurality of core pieces 97A, 97B, 97C, and 97D, and the core pieces 97A, 97B97C,
And protrusions 96A, 96B, 96C, 96D formed on the upper surface of 97D.

  The primary coil 58 includes coils 91A, 91B, 91C, 91D wound around the core pieces 97A, 97B, 97C, 97D. The coils 91A, 91B, 91C, 91D are respectively connected to the fourth coil portions 66A, 66B, 66C, 66D wound around the core pieces 97A, 97B, 97C, 97D and the protruding portions 98A, 98B, 98C, 98D. 5th coil 90A, 90B, 90C, 90D wound is included.

  The fourth coil portions 66B and 66D are formed so as to surround the winding axis O8a and wind the coil wire so as to be displaced in the extending direction of the winding axis O8a from the one end side toward the other end side. It is formed by turning. The fourth coil portions 66A and 66C are formed so as to surround the winding axis O8b and wind the coil wire so as to be displaced in the extending direction of the winding axis O8b from the one end side toward the other end side. It is formed by turning.

  And 5th coil 90A, 90B, 90C, 90D is formed so that the circumference | surroundings of the winding axis line extended to the perpendicular direction upper direction U may be surrounded.

  A case where power is transmitted between the power reception unit 20 and the power transmission unit 56 thus formed will be described.

  When power is transmitted between the power reception unit 20 and the power transmission unit 56, the protrusions 96 </ b> A, 96 </ b> B, 96 </ b> C, 96 </ b> D and the second coils 88 </ b> A, 88 </ b> B, 88 </ b> C, 88 </ b> D of the power reception unit 20 It arrange | positions above protrusion part 98A, 98B, 98C, 98D and 5th coil 90A, 90B, 90C, 90D.

  When a current of a predetermined frequency flows through the coils 91A, 91B, 91C, 91D of the power transmission unit 56, the magnetic path 99A passing through the coils 89A and 91A, the magnetic path 99B passing through the coils 89B and 91B, and the coil A magnetic path 99C passing through 89C and the coil 91C and a magnetic path 99D passing through the coil 89D and the coil 91D are formed.

  At this time, the end surfaces of the projecting portions 96A, 96B, 96C, and 96D and the end surfaces of the projecting portions 98A, 98B, 98C, and 98D are arranged to face each other.

  The winding axes of the second coils 88A, 88B, 88C, 88D extend toward the lower vertical direction D, and the winding axes of the fifth coils 90A, 90B, 90C, 90D are directed upward U in the vertical direction. It extends.

  For this reason, a magnetic path is satisfactorily formed between the power receiving unit 20 and the power transmitting unit 56, and power can be transmitted between the power receiving unit 20 and the power transmitting unit 56 satisfactorily.

(Embodiment 6)
The power receiving unit 20 according to the sixth embodiment will be described with reference to FIG. 26 and FIG. FIG. 26 is a cross-sectional view showing power reception unit 20 and power transmission unit 56 according to the sixth embodiment. As shown in FIG. 26, the size of the power transmission unit 56 is larger than that of the power reception unit 20.

  The power transmission unit 56 includes a coil unit 60, and the coil unit 60 includes a ferrite core 57 and a primary coil 58 wound around the ferrite core 57.

The primary coil 58 is wound around the peripheral surface of the ferrite core 57. The primary coil 58 is formed by winding a coil wire so as to surround the winding axis O10 and displace in the extending direction of the winding axis O10 from one end to the other end. In the direction in which the winding axis O <b> 10 extends, the length of the primary coil 58 is shorter than the length of the ferrite core 57. For this reason, both ends of the ferrite core 57 protrude from the primary coil 58. Portions of the ferrite core 57 that protrude from the primary coil 58 are a magnetic pole portion 92 and a magnetic pole portion 93.

  FIG. 27 is a perspective view schematically showing the coil unit 24 of the power reception unit 20. As shown in FIG. 27, the ferrite core 21 includes a plate portion 30, and a protruding portion 31 and a protruding portion 32 provided on the main surface 33 of the plate portion 30. The protruding portion 31 and the protruding portion 32 are arranged in a direction in which a winding axis O <b> 1 described later extends, and the protruding portion 31 and the protruding portion 32 are arranged on the end side of the main surface 33.

  In the present embodiment, the protruding portion 31 and the protruding portion 32 are arranged so as to be inclined. Specifically, the protruding portion 31 and the protruding portion 32 are formed such that the distance between them increases as the distance from the main surface 33 increases.

  The protruding portion 31 includes an end surface 39 and a peripheral surface from the outer peripheral edge portion of the end surface 39 toward the plate portion 30. The peripheral surface of the protrusion 31 includes side surfaces 35a, 36a, 37a, and 38a. The side surface 37 a and the side surface 38 a are located on opposite sides, and the side surface 37 a and the side surface 38 a are disposed so as to be inclined with respect to the plate portion 30.

  The protrusion 32 includes an end surface 40 and a peripheral surface from the outer peripheral edge portion of the end surface 40 toward the plate portion 30. The peripheral surface of the protrusion 32 includes side surfaces 35b, 36b, 37b, and 38b. The side surface 37b and the side surface 38b are located on opposite sides. The side surface 38a and the side surface 37b are disposed so as to face each other. The side surface 38 a and the side surface 37 b are disposed so as to be inclined with respect to the plate portion 30. The distance between the side surface 38a and the side surface 37b increases as the distance from the main surface 33 increases.

  The secondary coil 22 includes a first coil 41, a second coil 42 connected to one end of the first coil 41, and a third coil 43 connected to the other end of the first coil 41. Including.

  The first coil 41 is wound around the peripheral surface of the plate part 30. The first coil 41 surrounds the winding axis O1 and moves in the extending direction of the winding axis O1 as it goes from one end of the first coil 41 to the other end. It is formed by winding.

  The second coil 42 includes a tilt unit coil 81 and a main surface coil 82 connected to the tilt unit coil 81. The main surface coil 82 is wound around the peripheral surface of the protruding portion 31. Main surface coil 82 is formed to surround winding axis O20. The main surface coil 82 is formed by winding a coil wire so as to surround the winding axis O20 and displace in the extending direction of the winding axis O20 as it goes from one end to the other end. Yes. In the present embodiment, the main surface coil 82 is spirally wound around the peripheral surface of the protruding portion 31.

The third coil 43 includes a tilt unit coil 83 and a main surface coil 84. The main surface coil 84 is wound around the peripheral surface of the protruding portion 32. The main surface coil 84 is formed by winding a coil wire so as to be displaced in the extending direction of the winding axis O21 from one end to the other end. In the present embodiment, main surface coil 84 is wound a plurality of times. Here, as shown in FIG. 26 and FIG. 27, the winding axis O20 and the winding axis O21 extend so that the distance from each other increases from the power receiving unit 20 downward. That is, the winding axis O20 extends away from the power receiving unit 20 in the horizontal direction as it goes downward. In addition, in the example shown in FIG. 26, it extends so as to be displaced in the extending direction of the winding axis O1 as it goes downward. The winding axis O21 extends away from the power receiving unit 20 in the horizontal direction as it goes downward. In addition, in the example shown in FIG. 26, it extends so as to be displaced in the extending direction of the winding axis O1 as it goes downward.

  Then, as shown in FIG. 26, when power is transmitted in a non-contact manner between the power receiving unit 20 and the power transmission unit 56, the coil unit 24 and the coil unit 60 face each other.

  Also in the present embodiment, in a state where the coil unit 24 and the coil unit 60 face each other, the opposed surface of the coil unit 60 is the coil unit 24 in the surface of the coil unit 60 rather than the winding axis O10. It is a part located on the side. In the sixth embodiment, the opposing surface of coil unit 60 mainly includes main surface 64, the upper surface of magnetic pole portion 92, and the upper surface of magnetic pole portion 93.

  Similarly, the facing surface of the coil unit 24 is a portion located on the coil unit 60 side of the winding axis O1 in the surface of the coil unit 24 in a state where the coil unit 24 and the coil unit 60 face each other. .

  Specifically, the facing surface of the coil unit 24 mainly includes the end surface of the protruding portion 32, the main surface 33, and the end surface of the protruding portion 31.

  The winding axis O21 passes through the magnetic pole part 92, and the winding axis O20 passes through the magnetic pole part 93. For this reason, when power transmission is performed between the power reception unit 20 and the power transmission unit 56, the magnetic path 85 is favorably formed between the power reception unit 20 and the power transmission unit 56.

  The inclination angle of the protrusion 31 and the inclination angle of the protrusion 32 with respect to the main surface 33 of the ferrite core 21 can be appropriately set depending on the relationship between the magnetic pole part 92 and the magnetic pole part 93 of the power transmission part 56.

  In the present embodiment, the inclination angle of the protrusion 32 with respect to the main surface 33 of the ferrite core 21 and the inclination angle of the protrusion 32 with respect to the main surface 33 are substantially the same. And the inclination angle of the protrusion 31 may be different.

  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.

DESCRIPTION OF SYMBOLS 10 Vehicle, 11 Power receiving apparatus, 13 Rectifier, 14 Converter, 15 Battery, 16 Power control unit, 17 Motor unit, 20 Power receiving part, 21, 57 Ferrite core, 22 2nd coil, 23, 59 Capacitor, 50 Power transmitting apparatus, 51 External power supply device, 52 parking space, 53 AC power source, 54 high frequency power driver, 55
Control unit, 56 power transmission unit, 58 first coil.

Claims (19)

A first coil portion formed by winding a coil wire so as to surround the first winding axis and be displaced in the extending direction of the first winding axis;
A connecting coil portion connected to the first coil portion;
A non-contact power transmission coil unit comprising:
The connection coil portion is a non-contact power transmission coil unit formed so as to surround a virtual line extending in a direction different from a direction in which the first winding axis extends. A core,
The core includes a plate-like first winding part around which the first coil part is wound,
The first winding part includes a first main surface and a second main surface,
The said connection coil part is a coil unit for non-contact electric power transmission of Claim 1 containing the main surface coil arrange | positioned at the said 1st main surface. A coil unit for non-contact power transmission that receives power in a non-contact manner from a coil unit for power transmission,
3. The non-contact power transmission coil unit according to claim 1, wherein the virtual line extends toward the power transmission coil unit arranged to face the non-contact power transmission coil unit.   The non-contact power transmission coil unit according to claim 3, wherein the power transmission coil unit is disposed below the non-contact power transmission coil unit during power transmission, and the virtual line extends downward. A coil unit for non-contact power transmission that receives power in a non-contact manner with a coil unit for power transmission,
The coil unit for power transmission has a facing surface that faces the coil unit for non-contact power transmission when the coil unit for power transmission is disposed facing the coil unit for non-contact power transmission, and the virtual line passes through the facing surface. The coil unit for non-contact power transmission according to any one of claims 1 to 4, wherein   The coil unit for non-contact power transmission according to claim 2, wherein a winding axis of the main surface coil extends in a direction orthogonal to a direction in which the first winding axis extends.   The said connection coil part is a coil unit for non-contact electric power transmission of Claim 2 arrange | positioned so that the said virtual line may cross | intersect the said 1st main surface. The first coil portion includes a first end and a second end,
The said connection coil part contains the 2nd coil part connected to the said 1st end part, and the 3rd coil part connected to the said 2nd end part, The claim 1 in any one of Claims 1-7. Coil unit for non-contact power transmission.   A first winding portion including a first main surface and a second main surface; a second winding portion provided so as to protrude from the first main surface and wound with the second coil portion; The coil unit for non-contact power transmission according to claim 8, further comprising a core provided so as to protrude from the first main surface and including a third winding part around which the third coil part is wound. The second winding part includes a first end surface and a first peripheral surface extending from the first end surface toward the first main surface,
The third winding part includes a second end surface and a second peripheral surface extending from the second end surface toward the first main surface,
The area of the first end face is larger than the area of the cross section of the first winding portion in the direction perpendicular to the first winding axis.
10. The non-contact power transmission coil unit according to claim 9, wherein an area of the second end face is wider than a cross-sectional area of the first winding portion in a direction perpendicular to the first winding axis.   The height of the second winding part from the first main surface and the height of the third winding part from the first main surface are substantially equal to the thickness of the first winding part. The coil unit for non-contact power transmission according to claim 9 or claim 10.   The coil unit for non-contact power transmission according to claim 2, wherein the number of windings of the main surface coil is 1 or less.   A power receiving device that includes a power receiving unit including the coil unit for non-contact power transmission according to any one of claims 1 to 12, and that receives power in a non-contact manner from a power transmitting device including the power transmitting unit.   The power receiving device according to claim 13, wherein a difference between the natural frequency of the power transmitting unit and the natural frequency of the power receiving unit is 10% or less of the natural frequency of the power receiving unit.   The power receiving device according to claim 13, wherein a coupling coefficient between the power receiving unit and the power transmitting unit is 0.1 or less.   The power reception unit is formed between the power reception unit and the power transmission unit and vibrates at a specific frequency, and an electric field formed between the power reception unit and the power transmission unit and vibrates at a specific frequency. The power receiving device according to claim 13, wherein power is received from the power transmission unit through at least one of the power transmission unit. A power receiving device according to any one of claims 13 to 16, comprising:
A vehicle in which a coil unit for non-contact power transmission is arranged so that the virtual line is directed downward.   A power transmission apparatus including the coil unit for non-contact power transmission according to claim 1.   The power transmission device according to claim 18, wherein the non-contact power transmission coil unit is arranged so that the virtual line is directed upward.