JP2019169531A - Coil unit, wireless power transmission device, wireless power reception device, and wireless power transmission system - Google Patents

Abstract

To provide a coil unit capable of achieving both long-distance transmission of power and stabilization of transmitted power.SOLUTION: A coil unit 14 includes a first magnetic body B1 having a first surface and a second surface that is the surface opposite to the first surface, a first coil 141 in which a first conductor is spirally disposed on the first surface, a second coil 142 in which a second conductor is wound around the first magnetic body B1 as a solenoid coil covering each of a part of the first surface and a part of the second surface, and a third coil 143 in which a third conductor is conductor spirally disposed on the second surface.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a coil unit, a wireless power transmission device, a wireless power reception device, and a wireless power transmission system.

  Research and development of technologies related to wireless power transmission, which is the transmission of power by wireless, are being conducted.

  In wireless power transmission, it is known that a distance for transmitting power can be increased by using a solenoid coil as an antenna.

  On the other hand, in wireless power transmission, as a method for stabilizing the power received by the power receiving device from the power transmitting device, information indicating the power received by the power receiving device is transmitted to the power transmitting device, and the power transmitting device is sent to the power receiving device based on the information. A method for controlling the power to be transmitted is known. Here, the power transmission device is a device on the power transmission side that transmits power to the power receiving device. The power receiving device is a device on the power receiving side that receives power transmitted from the power transmitting device. Transmission of information from the power receiving apparatus to the power transmitting apparatus is often performed by communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark). However, when using the communication, the manufacturing cost for manufacturing each of the power transmission device and the power reception device increases.

  In view of the above circumstances, in a device that performs wireless power transmission, there is a case where a method is used in which power is transmitted by a solenoid coil and signals indicating various information are transmitted by a signal transmission coil. Accordingly, the device can increase the distance for transmitting power and can stabilize the power received by the power receiving device. In addition, the apparatus can suppress an increase in manufacturing cost as compared with a case where communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark) is used.

  In this regard, a first system coil antenna having a first coil conductor wound around a first winding axis, a first coil opening surrounded by the first coil conductor, and a first winding axis A second system coil antenna having a second coil conductor wound around a second winding axis in a direction different from the direction, and a second coil opening surrounded by the second coil conductor, As viewed from the direction of the first winding axis, an antenna device is described in which the second coil conductor is positioned in the formation region of the first coil conductor and the first coil opening in the direction of the second winding axis (Patent Document 1). reference).

International Publication No. 2017/094355

  Here, in such an antenna device, a solenoid coil for transmitting power and a spiral coil for transmitting signals indicating various kinds of information are mounted. The power signal is an electromagnetic wave that transmits power. The spiral coil is a coil in which a conductor is provided in a spiral shape on a certain surface. However, in the antenna device, the power signal transmitted by the solenoid coil may be superimposed on the signal transmitted by the spiral coil. As a result, in some cases, it is difficult for the antenna device to stabilize the power received by the power receiving device including the antenna device.

  The present invention has been made in consideration of such circumstances, and a coil unit, a wireless power transmitting device, a wireless power receiving device, and wireless power that can achieve both long-distance transmission of power and stabilization of the transmitted power. It is an object to provide a transmission system.

  One aspect of the present invention includes a first magnetic body having a first surface and a second surface that is a surface opposite to the first surface, and is disposed on the first surface. The second conductor is wound around the first magnetic body as a solenoid coil that covers each of the first coil provided with the first conductor in a spiral shape and a part of the first surface and a part of the second surface. And a third coil disposed on the second surface and provided with a third conductor spirally on the second surface.

  According to the present invention, it is possible to achieve both long-distance transmission of electric power and stabilization of electric power to be transmitted.

It is a figure showing an example of composition of wireless power transmission system 1 concerning an embodiment. 3 is a top view illustrating an example of a configuration of a coil unit 14. FIG. It is a bottom view of the coil unit 14 shown in FIG. It is sectional drawing which shows an example of the cross section of the coil unit 14 shown in FIG. It is sectional drawing which shows an example of the coil unit 14 in case the 2nd magnetic body B2 is arrange | positioned between the 1st coil 141 and 1st magnetic body B1. When the second magnetic body B2 is disposed between the first coil 141 and the first magnetic body B1, and the third magnetic body B3 is disposed between the third coil 143 and the first magnetic body B1. 3 is a cross-sectional view showing an example of a coil unit 14. FIG. It is a figure which shows an example of the coil unit 14 in case both the 1st coil 141 and the 3rd coil 143 are the coil patterns provided in the flexible substrate. FIG. 6 is a cross-sectional view of the coil unit 14 when the coil unit 14 is cut along a surface along the winding axis of the second coil 142 and perpendicular to the upper surface M1. It is a figure which shows an example of one flexible substrate in which the 1st coil 141 and the 3rd coil 143 were provided.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Overview of wireless power transmission system>
An overview of the wireless power transmission system 1 according to the embodiment will be described. FIG. 1 is a diagram illustrating an example of a configuration of a wireless power transmission system 1 according to the embodiment. In the following, for convenience of explanation, wireless power transmission will be referred to as wireless power transmission.

  The wireless power transmission system 1 includes a wireless power transmission device 10 and a wireless power reception device 20. In the wireless power transmission system 1, power is transmitted from the wireless power transmission device 10 to the wireless power reception device 20 by wireless power transmission.

  As shown in FIG. 1, the wireless power transmission device 10 is connected to a DC power source 11. The wireless power transmission apparatus 10 includes a power transmission circuit 12 (amplifying unit), a control circuit 13, and a coil unit 14. The coil unit 14 includes a first coil 141, a second coil 142, and a third coil 143. Here, the coil in this embodiment is a conductor wound around at least one of a certain region and a certain object, or a conductor provided in a spiral shape around at least one of a certain region and a certain object. This means that a conductor as a lead line connected from the conductor to another circuit is not included.

  The DC power supply 11 may be any power supply as long as it can supply a DC voltage. For example, the DC power supply 11 is a DC power supply obtained by rectifying and smoothing a commercial power supply, a secondary battery, a switching power supply, or the like. A switching power supply is a switching converter or the like. The DC power supply 11 supplies a DC voltage to the power transmission circuit 12.

  The power transmission circuit 12 may be configured to include an inverter that converts a DC voltage output from the DC power supply 11 into an AC voltage having a driving frequency, and is provided between the DC power supply 11 and the inverter in addition to the inverter. It may be configured to include a DC (Direct Current) / DC converter, or may be configured to include another circuit that converts a DC voltage output from the DC power supply 11 into an AC voltage having a driving frequency. The inverter is, for example, a switching circuit (a full bridge circuit, a half bridge circuit, or the like) in which switching elements are bridge-connected. Hereinafter, as an example, the power transmission circuit 12 includes an inverter that converts a DC voltage output from the DC power supply 11 into an AC voltage having a driving frequency, and a DC / DC converter provided between the DC power supply 11 and the inverter. The case will be described. The power transmission circuit 12 supplies the converted AC voltage to the second coil 142 included in the coil unit 14.

The control circuit 13 controls the output DC voltage of the DC / DC converter included in the power transmission circuit 12. The control circuit 13 may be configured to control the drive frequency of the inverter provided in the power transmission circuit 12 instead of the configuration to control the output DC voltage of the DC / DC converter, and control the duty ratio of the inverter. The structure which controls may be sufficient, and the structure which controls the duty ratio of the said inverter while controlling the drive frequency of the said inverter may be sufficient.
Further, the control circuit 13 inputs and acquires a control signal received from the wireless power receiving apparatus 20 by the first coil 141 included in the coil unit 14. This control signal is a signal related to the control of the output DC voltage of the DC / DC converter included in the power transmission circuit 12. The control circuit 13 controls the output DC voltage in accordance with the acquired control signal, and changes the output DC voltage as necessary.

  The first coil 141 is a coil that functions as a communication antenna. The first coil 141 receives a control signal transmitted from the wireless power receiving device 20. Here, the first coil 141 may be interlinked with magnetic flux generated by the second coil 142 described later.

  The second coil 142 is a coil that functions as an antenna for power transmission. The second coil 142 transmits power to the wireless power receiving device 20 by wireless power transmission.

  The third coil 143 is a coil having a function of generating a current that cancels a current flowing through the first coil 141 when the magnetic flux generated by the second coil 142 is linked to the first coil 141. Here, in the coil unit 14, the magnetic flux linked to the first coil 141 among the magnetic flux generated by the second coil 142 is equal to the magnetic flux linked to the third coil 143 among the magnetic flux generated by the second coil 142. (Or almost equal). For this reason, the magnitude of the current flowing through the first coil 141 when the magnetic flux generated by the second coil 142 is linked and the current flowing through the third coil 143 when the magnetic flux generated by the second coil 142 is linked. The size is the same size. For this reason, when the coil unit 14 includes the third coil 143, the coil unit 14 generates the current flowing through the first coil 141 and the second coil 142 due to the linkage of the magnetic flux generated by the second coil 142. The magnetic flux to be linked can cancel out the current flowing through the third coil 143. In the present embodiment, the magnetic flux interlinked with the first coil 141 among the magnetic flux generated by the second coil 142, the magnetic flux interlinked with the third coil 143 among the magnetic flux generated by the second coil 142, and the like. The likelihood is equality when deviation due to noise, assembly error, etc. is allowed, and does not mean that the numerical values completely match. In the example illustrated in FIG. 1, the third coil 143 is connected to the first coil 141. In this case, in the coil unit 14, the current flowing through the first coil 141 due to the linkage of the magnetic flux generated by the second coil 142 and the magnetic flux generated by the second coil 142 are linked to the third coil 143. The flowing current cancels out. That is, the control circuit 13 described above obtains a control signal after such current cancellation has been performed from the first coil 141. Details of the third coil 143 will be described later.

The wireless power receiving apparatus 20 includes a coil unit 21, a rectifying / smoothing circuit 22, a detection unit 24, a comparison unit 25, and a signal generation unit 26. The coil unit 21 includes a first coil 211 and a second coil 212.
A load 23 is connected to the rectifying / smoothing circuit 22.

  The first coil 211 is a coil that functions as a communication antenna. The first coil 211 transmits the control signal supplied from the signal generator 26 to the wireless power transmission apparatus 10. In the present embodiment, as an example, a case where the configuration of the first coil 211 is the same as the configuration of the first coil 141 will be described.

  The second coil 212 is a coil that functions as an antenna for power transmission. The second coil 212 receives power transmitted from the wireless power transmitting apparatus 10 by wireless power transmission. In the present embodiment, as an example, a case where the configuration of the second coil 212 is the same as the configuration of the second coil 142 will be described.

  The third coil 213 is a coil having a function of generating a current that cancels the current flowing through the first coil 211 by interlinking the magnetic flux generated by the second coil 212 with the first coil 211. Here, in the coil unit 14, the magnetic flux linked to the first coil 211 among the magnetic flux generated by the second coil 212 is equal to the magnetic flux linked to the third coil 213 among the magnetic flux generated by the second coil 212. (Or almost equal). For this reason, the magnitude of the current that flows through the first coil 211 when the magnetic flux generated by the second coil 212 is linked and the current that flows through the third coil 213 when the magnetic flux generated by the second coil 212 is linked. The size is the same size. For this reason, when the coil unit 21 includes the third coil 213, the coil unit 21 generates a current flowing through the first coil 211 and a second coil 212 due to the linkage of the magnetic flux generated by the second coil 212. When the magnetic flux to be interlinked, the current flowing through the third coil 213 can be canceled out. In the example illustrated in FIG. 1, the third coil 213 is connected to the first coil 211. In this case, in the coil unit 14, the current flowing through the first coil 141 due to the linkage of the magnetic flux generated by the second coil 142 and the magnetic flux generated by the second coil 142 are linked to the third coil 143. The flowing current cancels out. In the present embodiment, as an example, a case where the configuration of the third coil 213 is the same as the configuration of the third coil 213 will be described. In the present embodiment, the magnetic flux interlinked with the first coil 211 among the magnetic flux generated by the second coil 212, the magnetic flux interlinked with the third coil 213 among the magnetic flux generated by the second coil 212, and the like. The likelihood is equality in the case where deviation due to noise, error, etc. is allowed, and does not mean that the numerical values completely match.

  In the present embodiment, in one example, the configuration of the coil unit 21 is the same as the configuration of the coil unit 14. The configuration of the first coil 211 may be different from the configuration of the first coil 141. The configuration of the second coil 212 may be different from the configuration of the second coil 142. The configuration of the third coil 213 may be different from the configuration of the third coil 143. That is, the configuration of the coil unit 21 may be the same as the configuration of the coil unit 14 or may be a different configuration.

  The rectifying / smoothing circuit 22 is connected to the second coil 212 and converts the AC voltage received by the second coil 212 into a DC voltage. The rectifying / smoothing circuit 22 supplies (outputs) the converted DC voltage to the load 23. The rectifying / smoothing circuit 22 is a converter, and includes, for example, a bridge diode (not shown) and a smoothing capacitor (not shown). For example, the rectifying / smoothing circuit 22 performs full-wave rectification on the AC voltage received by the second coil 212, and smoothes the full-wave rectified voltage using a smoothing capacitor.

The load 23 is supplied with a DC voltage from the rectifying and smoothing circuit 22. For example, the load 23 is a rechargeable secondary battery (for example, a lithium ion battery, a lithium polymer battery, or the like). Note that the load 23 may be another device that performs an operation corresponding to a DC voltage instead of the secondary battery.
A conversion circuit (for example, a DC / DC converter or a DC / AC (Alternating Current) inverter) that converts the output of the rectifying / smoothing circuit 22 is provided between the rectifying / smoothing circuit 22 and the load 23. May be.

  The detector 24 detects the voltage output from the rectifying / smoothing circuit 22. The detection unit 24 outputs the detected voltage to the comparison unit 25. The detector 24 may be configured to detect the current output from the rectifying / smoothing circuit 22 or may be configured to detect the power output from the rectifying / smoothing circuit 22.

  The comparison unit 25 compares the voltage output from the detection unit 24 with a reference voltage (target voltage), and outputs a difference between the voltage and the reference voltage to the signal generation unit 26.

  The signal generation unit 26 generates a control signal based on the difference output from the comparison unit 25. The signal generator 26 transmits the generated control signal to the wireless power transmitting apparatus 10 via the first coil 211. That is, in the wireless power transmission apparatus 10, the control circuit 13 controls the output DC voltage of the DC / DC converter included in the power transmission circuit 12 so that the difference indicated by the control signal acquired via the first coil 141 becomes small.

  With the configuration described above, in the wireless power transmission system 1, power is transmitted from the wireless power transmission device 10 to the wireless power reception device 20. Further, the wireless power transmitting apparatus 10 transmits power to the wireless power receiving apparatus 20 so that the DC voltage received by the wireless power receiving apparatus 20 and output to the load 23 is substantially constant. That is, in the wireless power transmission system 1, the wireless power transmitting apparatus 10 receives the control signal from the wireless power receiving apparatus 20 and controls the amount of transmitted power, thereby stabilizing the power received by the wireless power receiving apparatus 20.

<Configuration of coil unit>
The configuration of the coil unit 14 of the wireless power transmitting apparatus 10 will be described. In the present embodiment, the configuration of the coil unit 21 of the wireless power receiving device 20 is the same as the configuration of the coil unit 14 of the wireless power transmitting device 10, and thus the description thereof is omitted. Hereinafter, for convenience of explanation, the positive direction of the Z axis in the three-dimensional coordinate system shown in FIG. 2 will be referred to as the upward direction, and the negative direction of the Z axis will be referred to as the downward direction.

  FIG. 2 is a top view illustrating an example of the configuration of the coil unit 14. FIG. 3 is a bottom view of the coil unit 14 shown in FIG.

  In FIG. 2, the upper side of the coil unit 14 is the side where the wireless power transmitting apparatus 10 including the coil unit 14 faces the wireless power receiving apparatus 20, that is, the side on which the wireless power receiving apparatus 20 receives power.

  As shown in FIGS. 2 and 3, the coil unit 14 includes a first magnetic body B <b> 1, a first coil 141, a second coil 142, and a third coil 143. In addition to the first magnetic body B1, the first coil 141, the second coil 142, and the third coil 143, the coil unit 14 includes a capacitor that forms a resonance circuit, and a magnetic field generated by the second coil 142. An electromagnetic shielding body (for example, an aluminum plate) that suppresses leakage to the outside, a magnetic body that enhances magnetic coupling between coils (a magnetic body different from the first magnetic body B1), and the like may be used. Hereinafter, for convenience of explanation, a conductor provided as the first coil 141 (that is, a conductor constituting the first coil 141) is referred to as a first conductor, and a conductor provided as the second coil 142 (that is, the second coil). 142) is referred to as a second conductor, and a conductor provided as the third coil 143 (that is, a conductor constituting the third coil 143) is referred to as a third conductor.

  The first magnetic body B1 is a magnetic body having an upper surface M1 and a lower surface M3 that is a surface opposite to the upper surface M1. The upper surface M1 is a surface on which the first coil 141 is disposed. The lower surface M3 is a surface on which the third coil 143 is disposed. Below, the case where the shape of 1st magnetic body B1 is a rectangular plate shape is demonstrated as an example. In this case, each of the upper surface M1 and the lower surface M3 is a rectangular plane facing each other.

  In the example shown in FIG. 2, the upper surface M1 is orthogonal to the Z axis in the three-dimensional coordinate system shown in FIG. That is, the upper surface M1 is the upper surface of the first magnetic body B1 in the example. Note that the upper surface M1 may be a curved surface instead of a flat surface. The shape of the first magnetic body B1 may be any shape as long as it has a top surface M1 instead of a rectangular plate shape, and may be another shape such as a disk shape. The upper surface M1 is an example of a first surface.

  In the example shown in FIG. 3, the lower surface M3 is orthogonal to the Z axis in the three-dimensional coordinate system shown in FIG. That is, the lower surface M3 is the lower surface of the first magnetic body B1 in the example. In the example, the lower surface M3 is a surface parallel to the upper surface M1. Note that the lower surface M3 may be a curved surface instead of a flat surface. Further, the lower surface M3 may be a curved surface instead of a flat surface. The shape of the first magnetic body B1 may be any shape as long as it has a top surface M1 and a bottom surface M3 instead of a rectangular plate shape, and may be another shape such as a disk shape. . The lower surface M3 is an example of a second surface.

  The first coil 141 is disposed on the upper surface M1. The first coil 141 is a coil (spiral type) provided with a first conductor spirally on the upper surface M1. Here, the first coil 141 may be referred to as a spiral coil, a planar coil, or the like.

  As shown in FIG. 2, the first coil 141 has a coil opening H1 on the upper surface M1. The coil opening H1 is a region surrounded by the first conductor on the upper surface M1. Here, the region surrounded by the first conductor on the upper surface M1 is a region inside the conductor region in which the first conductor is provided when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1. . The region surrounded by the first conductor on the upper surface M1 is a region on the inner side from the innermost peripheral portion of the first coil 141 when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1. Also good. The first coil 141 generates a magnetic flux passing through the coil opening H1 when a current is passed through the first conductor. In the first coil 141, when the magnetic flux passing through the coil opening H1 changes, a current flows through the first conductor according to the law of electromagnetic induction.

  Below, the case where the 1st coil 141 is formed on the upper surface M1 by the conducting wire fixed so that it may not move to the upper surface M1 with an adhesive etc. is demonstrated as an example. The conducting wire is an example of the first conductor described above.

  The second coil 142 is a coil in which a second conductor is wound around the first magnetic body B1 as a solenoid coil that covers a part of the upper surface M1 and a part of the lower surface M3. Here, the second conductor is wound around the outer periphery of the first magnetic body B1 having the upper surface M1 provided with the first coil 141 and the lower surface M3 provided with the third coil 143. For this reason, a part of the coil opening H1 is covered with the second conductor on the upper surface M1. Further, a part of a coil opening H3 to be described later is covered with a second conductor on the lower surface M3.

  The third coil 143 is a coil for generating a current that cancels the current generated in the first coil 141 by the electromagnetic induction by the magnetic flux of the second coil 142 that is a solenoid coil, by the electromagnetic induction by the magnetic flux. The coil unit 14 includes the third coil 143, thereby suppressing the power transmitted by the second coil 142, which is a solenoid coil, from being superimposed on the signal transmitted by the first coil 141, which is a spiral coil. can do.

  The third coil 143 is disposed on the lower surface M3. The third coil 143 is a coil (spiral type) provided with a third conductor spirally on the lower surface M3. Here, the third coil 143 may also be referred to as a spiral coil, a planar coil, or the like.

  As shown in FIG. 3, the third coil 143 has the above-described coil opening H3 on the lower surface M3. The coil opening H3 is a region surrounded by the third conductor on the lower surface M3. Here, the region surrounded by the third conductor on the lower surface M3 is a region inside the conductor region where the third conductor is provided when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3. . The region surrounded by the third conductor on the lower surface M3 is a region on the inner side from the innermost peripheral portion of the third coil 143 when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3. Also good. The third coil 143 generates a magnetic flux passing through the coil opening H3 when a current is passed through the third conductor. In the third coil 143, when the magnetic flux passing through the coil opening H3 changes, a current flows through the third conductor according to the law of electromagnetic induction.

  Below, the case where the 3rd coil 143 is formed on the lower surface M3 by the conducting wire fixed so that it may not move to the lower surface M3 with an adhesive etc. is demonstrated as an example. The said conducting wire is an example of the above-mentioned 3rd conductor.

  Here, in the coil unit 14, the first shape that is the shape of the first coil 141 when the upper surface M1 is viewed from the direction orthogonal to the upper surface M1, and the third shape when the lower surface M3 is viewed from the direction. The third shape which is the shape of the coil 143 is substantially the same shape. Thereby, in the coil unit 14, the magnetic flux of the second coil 142 out of the magnetic flux passing through the first coil 141 and the magnetic flux of the second coil 142 out of the magnetic flux passing through the third coil 143 are substantially the same. can do. The first shape and the third shape are the magnetic flux of the second coil 142 out of the magnetic flux passing through the first coil 141 and the magnetic flux of the second coil 142 out of the magnetic flux passing through the third coil 143. Different shapes may be used as long as the difference is smaller than a predetermined size. The predetermined size is a size determined according to the detection accuracy of the signal transmitted by the first coil 141 by the control circuit 13. The predetermined size can be increased as the detection accuracy is higher.

  The third coil 143 may be configured to be electrically connected in series with the first coil 141 or may be configured not to be electrically connected to the first coil 141. However, when the third coil 143 is electrically connected to the first coil 141 in series, when the upper surface M1 and the lower surface M3 are viewed from the direction orthogonal to the upper surface M1, the first coil 141 is formed on the upper surface M1. The starting point where the winding direction of the first conductor provided in a spiral shape is the clockwise direction, and the winding direction of the third conductor provided as a third coil 143 on the lower surface M3 is the clockwise direction. The start point is connected. Alternatively, in this case, the first conductor provided in a spiral shape on the upper surface M1 as the first coil 141 is wound in the clockwise direction, and the third coil 143 is provided in a spiral shape on the lower surface M3. Further, the end point where the winding direction of the third conductor is the clockwise direction is connected. Thereby, in the coil unit 14, the magnetic flux generated by the second coil 142 interlinks the coil opening H1 and the current flowing through the first conductor, and the magnetic flux generated by the second coil 142 interlinks the coil opening H3. Thus, the current flowing through the third conductor cancels out.

  Here, the relative positional relationship of the first coil 141, the second coil 142, and the third coil 143 in the coil unit 14 will be described.

  A region M11 illustrated in FIG. 2 indicates a region covered with the second coil 142 in the region on the upper surface M1. Specifically, the region M11 is a region sandwiched between both ends of the second coil 142 in the coil opening H1 when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1. The both ends are both ends in the direction along the winding axis of the second coil 142 and both ends of the second coil 142 on the upper surface M1. In the example shown in FIG. 2, the second conductor is wound around the first magnetic body B1 so that the region M11 is sandwiched between the region M12 and the region M13. Each of the region M12 and the region M13 indicates a region that is not covered by the second coil 142 in the coil opening H1. Specifically, each of the region M12 and the region M13 is a region that is not sandwiched between both ends of the second coil 142 in the coil opening H1 when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1. is there.

  In addition, a region M31 illustrated in FIG. 3 indicates a region covered with the second coil 142 among regions on the lower surface M3. Specifically, the region M31 is a region sandwiched between both ends of the second coil 142 in the coil opening H3 when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3. The both ends are both ends in the direction along the winding axis of the second coil 142 and both ends of the second coil 142 on the lower surface M3. In the example shown in FIG. 3, the second conductor is wound around the first magnetic body B1 so that the region M31 is sandwiched between the region M32 and the region M33. Each of the region M32 and the region M33 indicates a region that is not covered by the second coil 142 in the coil opening H3. Specifically, each of the region M32 and the region M33 is a region that is not sandwiched between both ends of the second coil 142 in the coil opening H3 when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3. is there.

  That is, in the example shown in FIGS. 2 and 3, the second coil 142 divides the coil opening H1 into three regions (each of the regions M11 to M13) and the coil opening H3 into three regions (regions). Each of the coils M31 to M33) is a coil in which the second conductor is wound around the first magnetic body B1. If the second coil 142 is wound around the first magnetic body B1 as a solenoid coil covering each of a part of the upper surface M1 and a part of the lower surface M3, the second conductor is formed by another winding method. A coil wound around the first magnetic body B1 may be used.

  Further, in the coil unit 14, as shown in FIG. 4, the first coil 141 is located between the first magnetic body B1 and the second coil 142 (more specifically, the first coil 141 located on the upper surface M1 and the upper surface M1). And the third coil 143 is located between the first magnetic body B1 and the second coil 142 (more specifically, the second conductor located on the lower surface M3 and the lower surface M3). Between). FIG. 4 is a cross-sectional view showing an example of a cross section of the coil unit 14 shown in FIG. Specifically, FIG. 4 is a cross-sectional view of the coil unit 14 when the coil unit 14 is cut along a surface along the winding axis of the second coil 142 and perpendicular to the upper surface M1.

  When the 1st coil 141 is arrange | positioned between 1st magnetic body B1 and the 2nd coil 142, the 1st coil 141 is restrained by the upper surface M1, and a deformation | transformation is suppressed. As a result, the coil unit 14 can stabilize the electromagnetic characteristics of the first coil 141. The first coil 141 may be arranged on the upper surface M1 of the first magnetic body B1 around which the second conductor is wound, from above the second conductor. At this time, for example, a spacer not shown in FIG. 4 is arranged between the first conductor and the region where the second conductor is not wound on the upper surface M1. Thereby, a 1st conductor can be arrange | positioned from on the 2nd conductor on the upper surface M1 of 1st magnetic body B1 by which the 2nd conductor was wound.

  Moreover, when the 3rd coil 143 is arrange | positioned between 1st magnetic body B1 and the 2nd coil 142, the 3rd coil 143 is restrained by the lower surface M3, and a deformation | transformation is suppressed. As a result, the coil unit 14 can stabilize the electromagnetic characteristics of the third coil 143. The third coil 143 may be configured to be disposed from above the second conductor on the lower surface M3 of the first magnetic body B1 around which the second conductor is wound. At this time, for example, a spacer not shown in FIG. 4 is arranged between the region where the second conductor is not wound on the lower surface M3 and the third conductor. Thus, the third conductor can be disposed from above the second conductor on the lower surface M3 of the first magnetic body B1 around which the second conductor is wound.

  Here, in the coil unit 14, the relative positional relationship between the second conductor located on the upper surface M <b> 1 and the first coil 141 in the positional relationship when the upper surface M <b> 1 is viewed from the direction orthogonal to the upper surface M <b> 1. The twenty-first positional relationship and the twenty-third positional relationship between the second conductor located on the lower surface M3 and the third coil 143 in the positional relationship when the lower surface M3 is viewed from the direction orthogonal to the lower surface M3. The positional relationship is substantially the same positional relationship. Thereby, in the coil unit 14, the magnetic flux of the second coil 142 out of the magnetic flux passing through the first coil 141 and the magnetic flux of the second coil 142 out of the magnetic flux passing through the third coil 143 are substantially the same. can do. Here, the twenty-first positional relationship is, for example, the relative relationship between the position of the center of gravity of the second coil 142 when the top surface M1 is viewed from the direction orthogonal to the top surface M1 and the position of the center of gravity of the first coil 141 in this case. It is expressed by a general positional relationship. The 23rd positional relationship is, for example, the relative position between the position of the center of gravity of the second coil 142 when viewed on the lower surface M3 from the direction orthogonal to the lower surface M3 and the position of the center of gravity of the third coil 143 in this case. Expressed by various positional relationships.

  In the coil unit 14, the twenty-first positional relationship and the twenty-third positional relationship are the magnetic flux of the second coil 142 among the magnetic flux that passes through the first coil 141 and the magnetic flux that passes through the third coil 143. The positional relationship may be different from each other within a range in which the magnitude of the difference from the magnetic flux of the second coil 142 is smaller than the predetermined magnitude. Further, the position of the first coil 141 when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1 is represented by another position corresponding to the first coil 141, instead of the position of the center of gravity of the first coil 141. It may be a configuration. Further, the position of the second coil 142 when viewed on the upper surface M1 from a direction orthogonal to the upper surface M1 is represented by another position corresponding to the second coil 142 instead of the position of the center of gravity of the second coil 142. It may be a configuration. In addition, the position of the second coil 142 when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3 is represented by another position corresponding to the second coil 142 instead of the position of the center of gravity of the second coil 142. It may be a configuration. Further, the position of the third coil 143 when viewed on the lower surface M3 from a direction orthogonal to the lower surface M3 is represented by another position corresponding to the third coil 143, instead of the position of the center of gravity of the third coil 143. It may be a configuration.

  With the configuration as described above, the coil unit 14 receives the control signal described above by the first coil 141 and transmits power by the second coil 142. The coil unit 14 includes the first coil 141 as a communication coil, so that the power transmitted from the wireless power transmitting apparatus 10 to the wireless power receiving apparatus 20 can be stabilized. Moreover, in the coil unit 14, long distance transmission of electric power is enabled by making the 2nd coil 142 into a solenoid coil.

  In addition, since the coil unit 14 includes the third coil 143, the coil unit 14 has a current generated in the first coil 141 due to the electromagnetic induction by the magnetic flux of the second coil 142 that is a solenoid coil, and the first by the electromagnetic induction by the magnetic flux. The current generated in the three coils 143 can cancel each other.

  Specifically, when the first coil 141 and the third coil 143 are electrically connected in series as described above, the first coil 141 is brought into contact with the first coil 141 by electromagnetic induction by the magnetic flux of the second coil 142 that is a solenoid coil. The generated current and the current generated in the third coil 143 by electromagnetic induction by the magnetic flux cancel each other. Thereby, the coil unit 14 can suppress the influence which arises when the electric power transmitted by the 2nd coil 142 which is a solenoid coil interferes with the signal transmitted by the 1st coil 141 which is a spiral coil.

  Further, when the first coil 141 and the third coil 143 are not electrically connected, the voltage generated in the first coil 141 by the electromagnetic induction by the magnetic flux of the second coil 142 that is a solenoid coil, and the electromagnetic induction by the magnetic flux Thus, the voltage generated in the third coil 143 can be canceled out using a circuit such as an arithmetic circuit (not shown). Thereby, even in this case, the coil unit 14 has an effect caused by the power transmitted by the second coil 142, which is a solenoid coil, interfering with the signal transmitted by the first coil 141, which is a spiral coil. Can be suppressed.

  Thus, the coil unit 14 can achieve both long-distance transmission of electric power and stabilization of electric power to be transmitted.

  In the coil unit 14, as shown in FIGS. 2 to 4, the first magnetic body B <b> 1 is used as a magnetic body that increases the inductance of the first coil 141 and the third coil 143, and the second coil 142 is used. The first magnetic body B1 is used as a magnetic body that increases the inductance of the first magnetic body B1. Thereby, the coil unit 14 is different from the case of using different magnetic bodies for the magnetic body that increases the inductance of the first coil 141 and the third coil 143 and the magnetic body that increases the inductance of the second coil 142. Can be downsized.

<Variation 1 of coil unit>
Hereinafter, Modification 1 of the coil unit 14 described above will be described. In the first modification of the coil unit 14, the permeability between the first coil 141 and the first magnetic body B <b> 1 is higher than the permeability of the first magnetic body B <b> 1 in a predetermined frequency band. A second magnetic body B2 having frequency characteristics is disposed. The second magnetic body B2 may be any magnetic body as long as the magnetic body has frequency characteristics. The predetermined frequency band may be any frequency band as long as it includes a frequency band for signal transmission by the first coil 141. In the present embodiment, the frequency band of power transmission by the second coil 142 is a lower frequency band than the frequency band of signal transmission by the first coil 141.

  FIG. 5 is a cross-sectional view illustrating an example of the coil unit 14 when the second magnetic body B2 is disposed between the first coil 141 and the first magnetic body B1. Specifically, FIG. 5 is a cross-sectional view of the coil unit 14 when the coil unit 14 is cut along a plane along the winding axis of the second coil 142 and perpendicular to the upper surface M1. In this case, the coil unit 14 can suppress the magnetic flux passing through the coil opening H1 from entering the coil opening H3 through the first magnetic body B1 by the second magnetic body B2. As a result, the magnetic flux passing through the coil opening H3 is substantially the magnetic flux of the second coil 142. As a result, the coil unit 14 more reliably generates a current generated in the first coil 141 due to electromagnetic induction by the magnetic flux of the second coil 142, which is a solenoid coil, and a current generated in the third coil 143 due to electromagnetic induction by the magnetic flux. Can cancel each other. As a result, the coil unit 14 more reliably suppresses the influence caused by the power transmitted by the second coil 142, which is a solenoid coil, interfering with the signal transmitted by the first coil 141, which is a spiral coil. be able to.

  The second magnetic body B2 is configured to be disposed between the third coil 143 and the first magnetic body B1 instead of the configuration disposed between the first coil 141 and the first magnetic body B1. There may be.

  Further, as shown in FIG. 6, the coil unit 14 includes a second magnetic body B2 disposed between the first coil 141 and the first magnetic body B1, and a third coil 143 and the first magnetic body B1. The third magnetic body B3 may be arranged between the two. In FIG. 6, the second magnetic body B2 is disposed between the first coil 141 and the first magnetic body B1, and the third magnetic body B3 is disposed between the third coil 143 and the first magnetic body B1. It is sectional drawing which shows an example of the coil unit 14 in the case where it is done. Specifically, FIG. 6 is a cross-sectional view of the coil unit 14 when the coil unit 14 is cut along a plane along the winding axis of the second coil 142 and orthogonal to the upper surface M1. The third magnetic body B3 may be any magnetic body as long as the magnetic body has a frequency characteristic of magnetic permeability that is higher than the magnetic permeability of the first magnetic body B1 in a predetermined frequency band. As a result, the coil unit 14 is more reliable that the magnetic flux passing through the coil opening H1 enters the coil opening H3 through the first magnetic body B1 by the second magnetic body B2 and the third magnetic body B3. Can be suppressed.

<Modification Example 2 of Coil Unit>
Hereinafter, a second modification of the coil unit 14 described above will be described with reference to FIGS. In the second modification of the coil unit 14, at least one of the first coil 141 and the third coil 143 is a coil pattern provided on a flexible substrate. Below, the case where both the 1st coil 141 and the 3rd coil 143 are coil patterns provided in the flexible substrate as an example is demonstrated.

  FIG. 7 is a diagram illustrating an example of the coil unit 14 when both the first coil 141 and the third coil 143 are coil patterns provided on a flexible substrate. 8 is a cross-sectional view showing an example of the coil unit 14 shown in FIG. Specifically, FIG. 8 is a cross-sectional view of the coil unit 14 when the coil unit 14 is cut along a surface along the winding axis of the second coil 142 and orthogonal to the upper surface M1. In FIG. 8, the flexible substrate is omitted in order to avoid complication of the drawing, and only the coil patterns provided on the flexible substrate as the first coil 141 and the third coil 143 (that is, the first conductor and the third conductor). Conductors only) are shown as first coil 141 and third coil 143.

  As shown in FIGS. 7 and 8, when the first coil 141 is a coil pattern provided on the flexible substrate, the flexible substrate is disposed (attached) on the upper surface M1. In addition, when the third coil 143 is a coil pattern provided on the flexible substrate, the flexible substrate is disposed (attached) on the lower surface M3. Thereby, the coil unit 14 can be manufactured easily and the manufacturing cost can be suppressed. As a result, the coil unit 14 is easily mass-produced.

  Further, both the first coil 141 and the third coil 143 may be coil patterns provided on one flexible substrate as shown in FIG. FIG. 9 is a diagram illustrating an example of one flexible substrate on which the first coil 141 and the third coil 143 are provided. In the example shown in FIG. 9, the first coil 141 and the third coil 143 are electrically connected in series. Further, the flexible substrate shown in FIG. 9 is a developed view of the flexible substrate attached to the coil unit 14. That is, in the coil unit 14, the flexible substrate has a portion where the coil pattern of the first coil 141 is provided on the upper surface M1, and a portion where the coil pattern of the third coil 143 is provided on the lower surface M3. Is bent and attached to the first magnetic body B1. Thereby, the coil unit 14 can be manufactured more easily and the manufacturing cost can be further suppressed.

  Here, the frequency of signal transmission performed between the first coil 141 and the first coil 211 described above is, for example, the frequency of power transmission performed between the second coil 142 and the second coil 212. 10 times or more. Note that the frequency of signal transmission performed between the first coil 141 and the first coil 211 may be less than 10 times the frequency of power transmission performed between the second coil 142 and the second coil 212. Good.

  The first magnetic body B1 described above may be configured by combining a plurality of magnetic bodies, for example. In this case, in a state where the first magnetic body B1 is configured by combining the plurality of magnetic bodies, a configuration in which there is no break between the plurality of magnetic bodies in the direction parallel to the winding axis of the power transmission coil 301 is preferable.

  Moreover, in the coil unit 14 demonstrated above, the structure which arrange | positions adjacent 2nd conductors (insulating films) mutually spaced apart (that is, without contacting) is used in a part or all of the 2nd coil 142. May be.

  Further, each of the first conductor, the second conductor, and the third conductor described above is covered with, for example, an insulating film. However, in each of FIGS. 2 to 9, the insulating films of the first conductor, the second conductor, and the third conductor are omitted in order to prevent the drawings from becoming complicated.

Further, in the above description, being arranged on the upper surface M1 means being arranged in a space on the upper surface M1. For this reason, for example, in the coil unit 14, the structure by which a spacer etc. are arrange | positioned between the 1st coil 141 or the 2nd coil 142, and the upper surface M1 may be sufficient. Further, the spacer may have a flat plate shape, or may have a shape other than a flat plate having unevenness.
In the above description, being arranged on the lower surface M3 means being arranged in a space on the lower surface M3. For this reason, for example, in the coil unit 14, the structure by which a spacer etc. are arrange | positioned between the 3rd coil 143 or the 2nd coil 142, and the lower surface M3 may be sufficient. Further, the spacer may have a flat plate shape, or may have a shape other than a flat plate having unevenness.

  As described above, the coil unit according to the embodiment (in this example, each of the coil unit 14 and the coil unit 21) has the first surface (in this example, the upper surface M1) and the surface opposite to the first surface. A first magnetic body (in this example, the first magnetic body B1) having a second surface (in this example, the lower surface M3) and a first magnetic body disposed on the first surface and spirally on the first surface. A first magnetic body as a solenoid coil that covers a first coil provided with a conductor (in this example, the first coil 141 and the first coil 211) and a part of the first surface and a part of the second surface The second coil (in this example, the second coil 142 and the second coil 212) wound with the second conductor is disposed on the second surface, and the third conductor is provided in a spiral shape on the second surface. Third coil (an example of this) Comprising Oite, third coil 143, a third coil) not shown coil unit 21 comprises, a. Thereby, the coil unit 14 can achieve both long-distance transmission of electric power and stabilization of electric power to be transmitted.

  In the coil unit, the shape of the first coil when viewed on the first surface from the direction orthogonal to the first surface and the third coil when viewed on the second surface from the direction orthogonal to the first surface Is substantially the same shape, and the relative relationship between the second conductor and the first coil located on the first surface in the positional relationship when the first surface is viewed from the direction orthogonal to the first surface. The relative positional relationship between the second conductor located on the second surface and the third coil among the positional relationships when the second surface is viewed from the direction orthogonal to the second surface is: A configuration having substantially the same positional relationship may be used.

  Further, in the coil unit, between the first coil and the first magnetic body, there is a frequency characteristic of magnetic permeability that is higher in permeability than the magnetic permeability of the first magnetic body in the frequency band of transmission by the first coil. A configuration in which the second magnetic body (in this example, the second magnetic body B2) is disposed may be used.

  Further, in the coil unit, a frequency characteristic of permeability between the third coil and the first magnetic body has a permeability that is higher in permeability than the permeability of the first magnetic body in the frequency band of transmission by the first coil. A configuration in which the third magnetic body (in this example, the third magnetic body B3) is disposed may be used.

  In the coil unit, a configuration in which at least one of the first coil and the third coil is a coil pattern provided on the flexible substrate may be used.

  In the coil unit, a configuration in which both the first coil and the third coil are coil patterns provided on one flexible substrate may be used.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and changes, substitutions, deletions, and the like are possible without departing from the gist of the present invention. May be.

DESCRIPTION OF SYMBOLS 1 ... Wireless power transmission system, 10 ... Wireless power transmission device, 11 ... DC power supply, 12 ... Power transmission circuit, 13 ... Control circuit, 14 ... Coil unit, 20 ... Wireless power receiving device, 21 ... Coil unit, 22 ... Rectification smoothing circuit, 23 ... Load, 24 ... Detector, 25 ... Comparator, 26 ... Signal generator, 141, 211 ... First coil, 142, 212 ... Second coil, 143 ... Third coil, B1 ... First magnetic body, B2 ... second magnetic body, B3 ... third magnetic body, H1, H3 ... coil opening, M1 ... upper surface, M3 ... lower surface, M11 ... region, M12 ... region, M13 ... region, M31 ... region, M32 ... region, M33 …region

Claims (9)

A first magnetic body having a first surface and a second surface which is a surface opposite to the first surface;
A first coil disposed on the first surface and provided with a first conductor spirally on the first surface;
A second coil in which a second conductor is wound around the first magnetic body as a solenoid coil covering each of a part of the first surface and a part of the second surface;
A third coil disposed on the second surface and provided with a third conductor spirally on the second surface;
A coil unit comprising: The shape of the first coil when viewed on the first surface from a direction orthogonal to the first surface, and the third coil when viewed on the second surface from a direction orthogonal to the first surface Is almost the same shape as
A relative positional relationship between the second conductor located on the first surface and the first coil in a positional relationship when viewed on the first surface from a direction orthogonal to the first surface; Of the positional relationships when the second surface is viewed from the direction orthogonal to the second surface, the relative positional relationship between the second conductor positioned on the second surface and the third coil is approximately The same positional relationship,
The coil unit according to claim 1. Between the first coil and the first magnetic body, there is a second frequency characteristic of magnetic permeability that is higher in permeability than the magnetic permeability of the first magnetic body in the frequency band of transmission by the first coil. Magnetic material is arranged,
The coil unit according to claim 1 or 2. Between the third coil and the first magnetic body, there is a third frequency characteristic of magnetic permeability that has a magnetic permeability higher than the magnetic permeability of the first magnetic body in the frequency band of transmission by the first coil. Magnetic material is arranged,
The coil unit according to any one of claims 1 to 3. At least one of the first coil and the third coil is a coil pattern provided on a flexible substrate.
The coil unit according to any one of claims 1 to 4. Both the first coil and the third coil are coil patterns provided on one flexible substrate.
The coil unit according to claim 5. The coil unit according to any one of claims 1 to 6,
A wireless power transmission device comprising: The coil unit according to any one of claims 1 to 6,
A wireless power receiving apparatus comprising: A wireless power transmission system comprising a wireless power transmission device and a wireless power reception device,
At least one of the wireless power transmitting device and the wireless power receiving device includes the coil unit according to any one of claims 1 to 6.
Wireless power transmission system.

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