JP2008109762A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device which can perform efficient energy power feeding, and is simple in constitution, in the power transmission device which feeds power to an electronic apparatus in a non-contact manner. <P>SOLUTION: A charging device 1 which is a power transmission device comprises: a primary coil 5 which can be magnetically coupled to a secondary coil 7 arranged at a camera 6; an AC-DC conversion circuit which feeds a current to the primary coil 5; a voltage detection part which detects an induction voltage at the primary coil side which is generated corresponding to a dummy current when the prescribed dummy current is fed to the secondary coil 7 by the magnetic coupling of the primary coil 5 and the secondary coil 7; an induction voltage setting part which controls the AC-DC conversion circuit by increasing a current when the induction voltage is lower than a coupled induction voltage which is generated when the coils are most efficiently and magnetically coupled to each other so as to reach the coupled induction voltage; and a position determination part which determines a positional relationship of the coils on the basis of a current value flowing through the primary coil 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission device that supplies electric power to an electronic device in a contactless manner.

As a power transmission device that supplies power to an electronic device in a non-contact manner, a device disclosed in Patent Document 1 is a separation transformer having a coil group that forms a plurality of magnetic paths in a primary device (transmitting energy and information). And a rotating magnetic field, a belt-like moving magnetic field, and the like are generated on the electromagnetic coupling surface by passing pulse currents and alternating currents having different times and phases through the coils. Thereby, the electromagnetic coupling possible area | region of a primary side apparatus and a secondary side apparatus can be expanded relatively, and electric power or information can be transmitted to a secondary side.
JP 2004-229406 A

  Since the electric power transmission device according to Patent Document 1 can relatively expand the electromagnetic coupling possible region between the primary device and the secondary device, the position of the coil of the primary device and the coil of the secondary device are The efficiency is expected to increase somewhat in terms of energy supply. However, the probability that the coil of the primary device and the coil of the secondary device always have a one-to-one corresponding positional relationship is quite small, and the most efficient energy supply is not always performed. In addition, since a separation transformer having a coil group that forms a plurality of magnetic paths must be formed, the configuration is complicated.

  The present invention has been made to solve the above-described problem, and in a power transmission device that supplies power to an electronic device in a contactless manner, the positional relationship between the primary device and the secondary device is energy efficient. It is an object of the present invention to provide a power transmission device that can determine with a simple configuration whether or not there is a positional relationship where power can be supplied.

  The power transmission device according to claim 1 of the present invention is a power transmission device that supplies power to an electronic device in a contactless manner, and a primary coil that is magnetically coupled to a secondary coil provided in the electronic device, and Supply means for supplying a current to the primary coil, and the primary coil and the secondary coil are magnetically coupled to each other when a predetermined dummy current is supplied to the secondary coil. Voltage detecting means for detecting the dielectric voltage on the primary coil side generated and the coupled dielectric voltage generated when the generated dielectric voltage is most effectively magnetically coupled between the primary coil and the secondary coil. Current control means for controlling the supply means so as to increase the current flowing in the primary coil so that the voltage of the primary coil becomes the coupling dielectric voltage, and supply to the primary coil. A current detecting means for detecting a current value, based on the current value flowing in the detected said primary coil comprises a determination means for determining the positional relationship between the primary coil and the secondary coil.

  The power transmission device according to claim 2 of the present invention is the power transmission device according to claim 1, further comprising a moving means for moving the primary coil, and a position of the primary coil and the secondary coil by the determination means. Movement control means for controlling the moving means to move the primary coil in an arbitrary direction when it is determined that the relationship is not the most suitable position for charging. The moving means moves the primary coil in an arbitrary direction so that the current value flowing through the primary coil is minimized.

  The power transmission device according to claim 3 of the present invention is the power transmission device according to claim 2, wherein the movement control means compares the current value of the primary coil detected by the current detection means at each movement position. The moving direction determining means for determining the moving direction of the primary coil is included.

  The power transmission device according to claim 4 of the present invention is the power transmission device according to any one of claims 1 to 3, wherein the current control means is most suitable for charging because of the positional relationship between the primary coil and the secondary coil. When it is determined to be in the position, the amount of current supplied from the supply means to the primary coil is switched to the amount of current for main charging.

  According to the present invention, in a power transmission device that supplies power to an electronic device in a contactless manner, the primary coil of the power transmission device that supplies power can supply power most efficiently to the secondary coil that is supplied with power. It is possible to determine with certainty whether or not there is.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an appearance of a charging device that is a power transmission device according to an embodiment of the present invention. FIG. 2 is a perspective view of an XY drive mechanism unit built in the charging apparatus. FIG. 3 is a main electric circuit diagram of the electric circuit unit built in the charging apparatus and the charging circuit unit of the camera electromagnetically coupled. FIG. 4 is a plan view of a primary coil incorporated in the charging device. 5 is a cross-sectional view taken along the line AA in FIG.

  The charging device 1 of the present embodiment is a charging device that performs charging (power supply) of a power source battery of a camera 6 that is an electronic device, for example, by a contactless method, and includes a mounting table 3 as shown in FIG. Electromagnetic coupling between a primary coil 5 movable on the apparatus main body 2 side and a secondary coil 7 on the camera side for charging the camera 6 placed at an arbitrary position on the mounting table 3. Can be performed by power transmission.

  The apparatus main body 2 incorporates an XY drive mechanism 10 which is a moving means arranged at the lower part of the mounting table 3 and an electric circuit part (substrate) 24. The X and Y axes are orthogonal coordinate axes along the plane of the mounting table 3.

  As shown in FIG. 2, the XY drive mechanism unit 10 includes a mechanism base 11, a feed screw shaft 12 and a guide shaft 13 that are axially supported by the mechanism base 11, and a feed screw shaft 12 and a guide shaft 13. An X-axis drive base 15 supported by the X-axis drive base 15, a feed screw shaft 16 and a guide shaft 17 that are supported by the X-axis drive base 15 along the Y-axis direction, and a Y that is supported by the feed screw shaft 16 and the guide shaft 17 The shaft drive base 18, the primary coil 5 held on the upper surface of the Y-axis drive base 18, and the periphery of the shaft end of the feed screw shaft 12 of the mechanism base 11 or the guide shaft of the X-axis drive base 15 are arranged. X-axis origin detection X sensor (hereinafter referred to as X sensor) 20 and a Y-axis origin detection Y sensor (hereinafter referred to as Y sensor) 22 composed of a photoreflector and an X axis at a predetermined movement position (origin position) Position facing the X sensor 20 on the drive base 15 Or the sensor reflectors 21 and 23 arranged at positions facing the Y sensor 22 on the Y-axis drive base 18, and the mechanism base 11 or the X-axis drive base 15, respectively, and the feed screw shaft 12, Alternatively, it has an X motor 14 and a Y motor 19 which are stepping motors that respectively rotate and drive 16. The electric circuit portion (substrate) 24 is disposed on the lower surface portion of the mechanism base 11.

  When the X motor 14 is driven to rotate, the X axis drive base 15 moves in the X axis direction. When the Y motor 19 is driven to rotate, the Y-axis drive base 18 supported by the X-axis drive base 15 moves in the Y-axis direction. Therefore, the Y-axis drive base 18 to which the primary coil 5 is fixed on the upper surface can be driven along the XY plane of the mounting table 3 by the X motor 14 and / or the Y motor 19.

  As shown in FIG. 3, the electric circuit unit 24 includes an AC-DC conversion circuit unit 30, and a DC-AC conversion circuit unit 32 that is a supply unit that receives the output of the conversion circuit unit 30 and supplies a primary coil current. The voltage detection unit 39 which is a voltage detection unit for detecting the terminal voltage (dielectric voltage) of the primary coil 5 and the current detection unit for detecting the output current (primary coil current) of the AC-DC conversion circuit unit 30 The current detection unit 31, the control unit 33 that controls the charging device, the drive unit 40 including the X and Y motors 14 and 19 and the X and Y sensors 20 and 22, and the output from the communication coil 41 are captured. A communication unit 42 that outputs to the memory unit 43 and a memory unit 43 that captures or stores image information, camera information, voltage control information, and charging-related information output from the camera are mounted.

  The control unit 33 includes a dielectric voltage setting unit 34 including a current control unit that controls the current of the primary coil so that the terminal voltage of the primary coil becomes a predetermined induction voltage, a movement control unit 35 that is a movement control unit, and a drive And a drive control unit 36 that controls the unit 40.

  The movement control unit 35 compares the current value detected by the current detection unit 31 with the position determination unit 37 that determines the relative positional relationship between the primary coil 5 and the secondary coil 7 based on the current value of the current detection unit 31. And a moving direction determining unit 38 for determining the moving direction of the primary coil 5 through the XY drive mechanism unit 10 in such a direction that the current is minimized in the primary coil position search process. Move control. As will be described in detail later, if the primary coil and the secondary coil are close to each other, this movement control is small even if a current is applied so that the primary coil has a predetermined induction voltage. It uses the principle that an induced voltage is not generated unless a current is passed.

  The primary coil 5 is a coil formed by being wound around an axis orthogonal to the XY plane shown in FIG. 1, and an electromagnetic wave reflection plate 5a is disposed on the lower surface thereof (FIGS. 4 and 5). A communication coil 41 is disposed adjacent to the primary coil 5 and on the same surface (FIG. 4). The communication coil 41 is a communication coil for capturing camera information and charging information sent from the camera side.

  As shown in FIG. 3, the camera 6 has a secondary coil 7, an AC-DC conversion circuit unit 51 to which the secondary coil 7 is connected, and a charging circuit unit to which the DC output of the AD-DC conversion circuit unit 51 is connected. 52, a control unit 53 for controlling the charging circuit unit 52, the changeover switch 55 and the communication unit 57, a camera power supply battery 54 formed of a lithium ion battery, and a camera power supply circuit unit 56 formed of a DC-DC converter. A communication unit 57 for outputting camera-side image information, camera information, and charging information to the communication coil 58 via the switch 55 is provided. Note that the charging circuit unit 52 is set to always charge the battery 54 in a constant state.

  A secondary coil 7 is disposed on the bottom surface of the camera 6. The secondary coil 7 has a symmetrical shape with the primary coil 5 in a state of being mounted on the mounting table 3 of the camera 6, is wound around an axis orthogonal to the XY plane, and is wound in the same manner as the primary coil 5. Have a number. Furthermore, an electromagnetic wave reflection plate is attached to the back surface of the coil. A camera-side communication coil 58 is disposed adjacent to the secondary coil.

  The secondary coil 7 does not necessarily have the same number of turns as the primary coil 5. That is, the charging efficiency may be increased by increasing the number of turns of the secondary coil 7 to about twice the number of turns of the primary coil 5. In addition, when the primary coil 5 and the secondary coil 7 are in the optimum electromagnetic coupling state, the communication coils 41 and 58 are in opposing positions where communication is possible.

  The charging processing operation to the power supply battery 54 of the camera 6 by the charging device 1 having the above-described configuration will be described with reference to FIGS.

  FIG. 6 is a diagram showing changes in charging voltage and charging current when charging the camera-side power source battery. FIG. 7 shows an example of primary coil current change and secondary coil current change from the preliminary search operation in which the dummy current at the primary coil position hardly flows through the optimum position search operation in which the dummy current flows to the start of the charging operation. FIG. FIG. 8 shows the primary coil relative to the separation position between the secondary coil and the primary coil in a state where a predetermined dummy current is passed through the secondary coil when the camera-side secondary coil and the primary coil are within the predetermined separation distance range. It is a figure which shows the change of the electric current which flows into.

  FIG. 9 is a diagram illustrating changes in the primary coil current with respect to the measurement timing pulse during the preliminary search operation. FIG. 10 is a diagram illustrating changes in the primary coil current with respect to the distance between the primary coil and the primary coil during the optimum position search operation. FIG. 11 is a diagram illustrating an example of changes in the X and Y axis movement amounts of the primary coil and changes in the primary coil current when the optimum position search operation is performed after the preliminary search operation. FIG. 12 is a flowchart of a main routine of “charging process” by the charging apparatus.

  When the battery 54 of the camera 6 is charged by the charging device 1, first, the camera 6 is placed at an arbitrary position on the mounting table 3 with the secondary coil 7 side on the lower surface side, and the power switch 4 is turned on. .

  Under the control of the control unit 33 and the drive unit 40 of the electric circuit unit 24, the XY drive mechanism unit 10 is drive-controlled to start the movement of the primary coil 5, and the preliminary search process in the main routine of the charging process in FIG. Step S1) is executed.

  In the preliminary search process, the XY drive mechanism unit 10 moves the primary coil 5 along a predetermined search trajectory to change the position of the primary coil 5 shown in FIG. 17 from the point P0 to the points P1 to P1. P24 etc.). By detecting a change in the current value of the primary coil 5 when it passes through the primary coil 5, a position within the electromagnetic coupling range of the primary coil 5 (a position within a closer region including an optimum position described later, for example, a point P20 in FIG. 17). ) And the primary coil 5 is driven to the position within the electromagnetic coupling range at the end of the preliminary search.

  The optimum position is a position where the primary coil 5 is directly below the camera-side secondary coil 7, in other words, an optimum electromagnetic coupling position at which the most efficient power transmission can be performed, for example, the point Ph in FIG.

  Subsequently, the optimum position search process (step S2) is executed. In this process, the charging device side primary coil 5 detects the optimum electromagnetic coupling position (optimum position, for example, the point Ph in FIG. 18) immediately below the camera side secondary coil 7 based on the change in the current value of the primary coil 5, and the position To move both coils to the optimum electromagnetic coupling state. In the optimal electromagnetic coupling state, electric power is transmitted from the primary coil 5 side to the secondary coil 7 side, and the battery 54 is efficiently charged (step S3).

  In the preliminary search process and the optimum position search process, when the secondary coil 7 is in an electromagnetically coupled state with the primary coil 5 on the camera 6 side, the secondary coil 7 has a predetermined preset value set on the camera side. The controller 53 controls the dummy current I2d (FIGS. 7 and 8) to flow.

  Further, during the preliminary search process and the optimum position search process, a predetermined voltage V1 is applied to the primary coil 5. The predetermined voltage V1 is a voltage for applying the predetermined dummy current I2d to the secondary coil 7. More specifically, the primary coil 5 is in the optimum electromagnetic coupling position, and the predetermined dummy current is applied to the secondary coil 7. The voltage is equal to the coupling induction voltage when I2d is flowing. The primary coil current I1 is caused to flow by this voltage V1.

  As shown in FIG. 8, when the primary coil 5 is within the electromagnetic coupling range with respect to the secondary coil 7, the dummy current I2d of the secondary coil 7 is kept constant, and the current I1 of the primary coil 5 due to the primary coil voltage V1. Changes as the mutual inductance changes between the coils due to the distance D between the primary coil 5 and the secondary coil 7. That is, in the electromagnetic coupling state, the current I1 is large when the separation distance D is large, and decreases when the separation distance D is small. When the primary coil 5 reaches the optimum electromagnetic coupling position that matches the position of the secondary coil 7, the current I1 becomes the minimum current I1d. In the optimum position retrieval process, the current I1 of the primary coil 5 is detected to retrieve the optimum electromagnetic coupling position.

  In the optimum position searching process, as described above, the dummy current I2d of the secondary coil 7 is set to a constant value on the camera 6 side. This is because when the primary coil 5 approaches the secondary coil 7 and the primary coil current decreases, the dummy current of the secondary coil increases and the secondary coil voltage also increases. If the current and voltage of the secondary coil 7 change, the accurate current and voltage of the primary coil 5 cannot be measured. Therefore, in this embodiment, the resistance is controlled by the charging circuit unit 52, the dummy current of the secondary coil 7 and its voltage are kept constant, and the current of the primary coil 5 relative to the current of the secondary coil 7 can be detected in this state. I am doing so. That is, the minimum value of the primary coil current value detected at that time is detected as a value in a state where the primary coil 5 of the charging device 1 with the secondary coil 7 on the camera 6 side is most efficiently charged. become.

  FIG. 9 shows that when the primary coil 5 reaches the point P20 in FIG. 17, for example, based on the measurement timing pulse output from the control unit, the primary coil 5 is applied with the voltage V1 of the primary coil 5 during the preliminary search process. It shows a state in which current I1 flows. This measurement timing t20 corresponds to the timing t20 of FIG. 7, and the primary coil current I1 at this time is detected by the current detection unit 31.

  Here, an example of changes in the primary coil current I1 and the secondary coil current I2 in the execution process of the preliminary search process, the optimum position search process in the charging process, and the subsequent charging process will be described with reference to FIG.

  During the preliminary search process, the primary coil 5 and the secondary coil 7 are far away, and almost no current flows through the primary coil 5 at time t0. Further, the current I2d0 of the secondary coil 7 is smaller than the predetermined dummy current I2d, assuming that the current I1d0 flows through the primary coil 5 even at time t1. Thereafter, the primary coil 5 passes through the position within the above-described electromagnetic coupling range (for example, the point P20) during time t1 to t2 during the preliminary search process. Reaching the position within the electromagnetic coupling range is detected by a relatively large current I1d1 of the primary coil 5 corresponding to the predetermined dummy current I2d flowing through the secondary coil 7. As will be described later, the current I1d1 of the primary coil 5 is predetermined in the secondary coil 7 when the primary coil 5 is in an optimum position relative to the secondary coil 7 (optimum electromagnetic coupling position, for example, point Ph). This value is larger than the current I1d of the primary coil 5 when the dummy current I2d flows. At time t2, which is the end of the preliminary search process, the primary coil 5 is moved to a position within the electromagnetic coupling range (for example, the point P20) far from the optimum electromagnetic coupling position described above. The current I1d1 flows through the primary coil 5.

  Thereafter, the optimum position search process (step S2) is executed. In the initial stage of this processing state, the primary coil 5 is at a position within the electromagnetic coupling range (for example, the point P20), and the primary coil current I1 becomes the smallest current value I1d while the primary coil 5 is finely driven. Search for the optimal electromagnetic coupling position. That is, when the primary coil voltage detected by the voltage detector 39 under the state where the dummy current I2d flows through the secondary coil 7 is V1 or less, the primary coil current I1 is increased and kept at the primary coil voltage V1. On the other hand, the primary coil 5 is driven and controlled in a direction in which the primary coil current I1 becomes smaller.

  As shown in FIG. 7, the primary coil current I <b> 1 decreases stepwise as a result of the drive control, and the primary coil 5 moves toward the optimal electromagnetic coupling position with good charging efficiency at which the secondary coil 7 approaches. When it is detected at time t4 that the primary coil current I1 is the minimum I1d, it is determined that the primary coil 5 has reached the optimum electromagnetic coupling position, and the optimum position search process is terminated.

  After completion of the optimum position search process, the control unit 33 applies the voltage V1ch to the primary coil 5, controls the primary coil 5 to pass a current I1ch greater than the current I1d, and charges the secondary coil 7 to the charging current I2ch. The charging operation is started. Changes in the charging voltage V2ch and the charging current I2ch during the charging operation are shown in FIG. That is, the charging voltage V2ch increases linearly with the start of charging, reaches a full charging voltage (4.2 V) after a lapse of time t10, and thereafter shows a constant value. On the other hand, the charging current I2ch starts to be charged at a predetermined constant value, and gradually becomes close to 0 after the time t10 has passed and the full charging state is reached.

  FIG. 10 shows that the primary coil current I1 decreases as the primary coil separation distance D decreases as the primary coil 5 moves from the movement point Pa to Ph during the elapsed time t3 to t4 in FIG. It shows the process of doing. Note that the movement points Pa to Ph indicate the primary coil movement points shown in FIG. 18, the movement point Pa is the primary coil position at the start of the optimum position search process, and the movement point Ph is the optimum position search process. The primary coil optimal electromagnetic coupling position at the time of completion | finish of is shown.

  As shown in FIG. 10, the primary coil current I1 is decreased as the primary coil currents Ia to Ih corresponding to the respective points from the movement points Pa to Ph are respectively reduced to the movement point Ph which is the primary coil optimum electromagnetic coupling position. Indicates the minimum value. By detecting the minimum primary coil current Ih, the arrival of the optimum electromagnetic coupling position of the primary coil is recognized.

  FIG. 11 shows the state of change in the primary coil current when the primary coil 5 moves from the movement point Pa to Ph during the elapsed time t3 to t4 in FIG. The change of the X-axis and Y-axis movement amount is shown. As shown in FIG. 11, according to the optimum position search processing operation, after reaching the moving point Ph where the primary coil current decreases, the surroundings are searched for confirmation, and the moving point Ph The primary coil optimum electromagnetic coupling position where the current I1d which is the minimum value is obtained is determined, and the process returns to the movement point Ph.

  The voltage V1 applied to the primary coil 5 is detected by the voltage detector 39 as the primary coil terminal voltage during the preliminary search process and the optimum position search process. The control unit 33 controls the primary coil current I1 so that the voltage V1 becomes a predetermined induced voltage by the induced voltage setting unit 34. The induced voltage setting unit 34 switches the primary coil terminal voltage to the primary coil voltage V1 during the above-described preliminary search process and optimum position search process, and to the primary coil voltage V1ch during charging.

  At the time of search, values such as the voltage V1 (inductive voltage) of the primary coil 5 and the applied voltage V1ch at the time of charging are stored in the memory unit of the control unit 33 and are called up as necessary. The applied voltage V1 of the primary coil 5 is equal to the coupling induction voltage when the primary coil 5 is at the optimum electromagnetic coupling position and the predetermined dummy current I2d flows through the secondary coil 7 as described above. In the search process, a voltage higher than that may be used. Further, the primary coil voltage V1ch during charging is higher than the applied voltage V1.

  Next, details of the charging process in the charging device 1 will be described with reference to the schematic flowcharts of FIGS. 7 to 11 and FIGS.

  FIG. 12 is a flowchart of the main routine of the charging process in the present charging device as described above, and FIG. 13 is a schematic flowchart of a subroutine “preliminary search process” called by the main routine of the charging process of FIG.

  Under the control of the control unit 33, the “preliminary search process” of the subroutine shown in FIG. 13 is called in step S1 of the main routine of FIG. In step S11 of the “preliminary search process”, the X and Y motors 14 and 19 are driven by the drive control unit 36 of the movement control unit 35, and the primary coil 5 is set in advance (the locus indicated by the broken line in FIG. 17). Along the X and Y axes.

  In step S12, the primary coil current I1 is measured when the measurement timing pulse is output in a state where the voltage V1 is applied at a position on the movement locus (point P1 etc. in FIG. 17). If the measured value is changed in step S13 and the measured value exceeds the current I1d, it is determined that the magnetic coupling region (range including the optimum magnetic coupling position) has been reached, and the process proceeds to step S14. If there is no change in the measured value, the process returns to step S11.

  In step S14, the coordinates of the reaching movement point are stored together with the measured current value.

  Subsequently, in step S15, it is checked whether or not the measurement of the primary coil current I1 at all the movement points of the movement locus is completed. If completed, the process proceeds to step S16, and in step S14, the data stored in the magnetic coupling area is stored. The primary coil 5 is moved to the moving point. However, when there are a plurality of stored movement points, the primary coil 5 is moved to the movement point with the smaller measured current value (the closer to the optimum magnetic coupling position), and the process returns to the main routine.

  Here, further detailed operations of the above-described subroutine “preliminary search processing” will be described with reference to FIGS.

  FIG. 14 is a diagram showing a flow (flow A) of a specific example in the subroutine “preliminary search process” of FIG. FIG. 17 is a diagram showing a movement locus of the primary coil on the mounting table in the flow A of the preliminary search operation of FIG.

  In the preliminary search process, the initial position P0 of the primary coil 5 is recognized as the power switch 4 of the charging apparatus 1 is turned on as shown in the flow A of FIG. 14, and the primary coil 5 is set to the origin from the initial position P0. Move to P1 (F1). This origin position is detected by outputs to the X and Y sensors 20, 22.

  Subsequently, the primary coil 5 is moved along the broken line in FIG. 17 (F2), and the current I1 of the primary coil 5 on the power transmission side is measured at the timing when the primary coil 5 reaches each of the moving points P1 to P24. (F3).

  When the primary coil 5 and the secondary coil 7 are outside the predetermined separation distance, the primary coil 5 is in a non-magnetic coupling state, the primary coil 5 is not loaded, and the primary coil current I1 does not change (F4). ).

  When the primary coil 5 reaches the moving point P20 in FIG. 17, the primary coil (power transmission side) 5 and the secondary coil (power reception side) 7 partially overlap (electromagnetic coupling state), and the primary coil current flows. The current I1 is measured (F5). The measured value and the movement position coordinate are stored in the memory (F6).

  After confirming that the movement of all the movement paths of the primary coil 5 and the current measurement have been completed, it is determined that the movement point P20 of the primary coil 5 is close to the position of the secondary coil 7 (electromagnetic coupling position), and the primary coil 5 is The preliminary search operation is terminated by moving to the movement point P20.

  Subsequent to the subroutine “preliminary search process”, the subroutine “optimum position search process” is called in step S2 of the main routine.

  The “optimum position search process” of the subroutine starts from a movement point P20 (the same point as point Pa in FIG. 18 described later), and first moves the primary coil 5 by a predetermined distance movement amount Δd in the + and −X axis directions. Let The primary coil current I1 is measured at the moving position. It is checked whether the measured current value is minimum or smaller in the movement range in the X-axis direction, and the primary coil 5 is moved to a position showing a minimum or smaller value. Subsequently, the primary coil 5 is moved by a predetermined distance movement amount Δd in the + and -Y axis directions, and the primary coil current I1 is measured at the movement position. It is checked whether the measured current value is minimum or smaller in the movement range in the Y-axis direction, and the primary coil 5 is moved to a position indicating a minimum or smaller value.

  After that, by moving by a predetermined distance movement amount Δd / 2 in the +, −X, and Y axis directions, the change in the primary coil current I1 in a finer movement range is measured, and the primary coil current I1 is the minimum value, or A point at which a smaller value is obtained (becomes the optimum electromagnetic coupling position) is searched, and a moving point where the measured current value is very close to I1d or very close to I1d (for example, point Ph in FIG. 18) is determined as the optimum electromagnetic coupling. This subroutine is terminated as a position, and the process returns to the main routine. The optimum electromagnetic coupling position reached by the primary coil 5 coincides with or substantially coincides with the position P00 (FIG. 18) of the secondary coil 7 on which the camera 6 is set.

  Here, further detailed operations of the above-described subroutine “optimum position search process” will be described with reference to FIGS.

  FIGS. 15 and 16 are diagrams showing a flow of processing (flow B) of a specific example in the subroutine “optimum position search processing”. FIG. 18 is a diagram showing a movement locus of the primary coil on the mounting table in the flow B of the optimum position search operation of FIGS.

  In the flow B of FIG. 15, first, the primary coil current Ia at the moving point Pa (that is, the point P20) searched by the above-described preliminary search operation is measured and stored (F11). And the measurement of the change of the primary coil current by the movement of the X direction of the primary coil 5 is started (F12). As shown in FIG. 18, it moves by a predetermined distance Δd in the −X direction, stores the moving point Pb, and measures and stores the primary coil current Ib at the point Pb (F13, F14). When the primary coil 5 moves away from the target optimum electromagnetic coupling position, it is necessary to flow more current through the primary coil 5 in order to maintain the dielectric voltage V (= the primary coil applied voltage V1).

  The primary coil currents Ia and Ib are compared (F15). When Ia <Ib, it is determined that the point Pb side is away from the target point, and the primary coil 5 is moved in the reverse direction (+ direction) by Δd. The moving point is set as Pc (F16). The primary coil current is measured at the point Pc, and the current value Ic is stored (F17).

  The current value Ic is compared with Ia and Ib (F18). If Ic <Ia and Ic <Ib, it is determined that the direction of the point Pc has approached the target point (optimal electromagnetic coupling position), and the X-direction coordinate of the point Pc is stored (F19). Therefore, the search (movement and measurement) in the X direction is temporarily stopped, and the search (movement and measurement) in the Y direction is started (F20).

  Before moving to the Y direction, the X direction movement and current measurement may be continued to search for the position of the minimum current value in the X direction, and then move to the Y direction movement and measurement. .

  The primary coil 5 is moved from the point Pc in the −Y direction by Δd, and the primary coil current measured at the point Pd is stored as Id (F21, F22). The currents Id and Ic are compared (F23). If Ic <Id, it is determined that the -Y direction is away from the target point, and the primary coil 5 is moved from the point Pc by + d in the + Y direction (F24). The primary coil current Ie is measured and stored at the arrival point Pe (F25).

  The current Ie is compared with Ic and Id (F26). If Ie <Ic and Ie <Id, it is determined that the point Pe side approaches the target point, and the Y-direction coordinate of the point Pe is stored. Then, the search in the Y direction is temporarily stopped and the search in the X direction is started again (F27).

  In this case as well, the search in the Y direction may be continued before the movement in the X direction, and the search in the X direction may be performed after searching for the position of the minimum current value in the Y direction.

  As shown in FIG. 16, in the previous search in the X direction, it is known that the -X direction (left direction) is away from the target point, so the primary coil 5 is moved by Δd in the + X direction, and the primary at the movement point Pf. The coil current If is measured and stored (F28, F29).

  The currents If and Ie are compared (F30). If If <Ie, it is determined that the + X direction is the direction approaching the target point, the search in the X direction is stopped, and the search in the Y direction is started (F31).

  The primary coil 5 is moved in the + Y direction by Δd from the point Pf (F32). The primary coil current Ig is measured and stored at the moving point Pg (F33).

  The currents Ig and If are compared (F34). If If <Ig, since the previous Y direction was also the + direction, it is determined that the target point has been passed. Then, the half value Δd / 2 is returned in the −Y direction, and the current Ih measured at the moving point Ph is stored (F35). Therefore, the search in the Y direction is terminated, and the search again in the X direction.

  It moves by Δd in the + X direction (F36), and measures and stores the current Ii at the moving point Pi (F37).

  The currents Ii and Ih are compared (F38). If Ii> Ih, it is determined that the vehicle has passed the target point, the half value Δd / 2 is returned in the −X direction (F39), and the current Ij at the moving point Pj is measured and stored (F40).

  The currents Ij and Ih are compared, and if Ij> Ih, the previous Y direction is also the + direction, so it is determined that the target point has been passed, and the half-value Δd / 2 is returned to the −X direction by the half value Δd / 2. Move to point Ph (F41). The movement point Ph is determined to be the optimum magnetic coupling position by returning by half value Δd / 2 in the same direction, and the optimum position search process is terminated (F42).

  Thereafter, the terminal voltage of the primary coil 5 is switched to the applied voltage V1ch at the time of charging, and charging of the battery 54 on the camera 6 side is started via the secondary coil 7.

  As described above, according to the charging device 1 of the present embodiment, the most efficient energy feeding is performed in the electromagnetic coupling state between the primary coil 5 and the secondary coil 7 by the preliminary search operation and the optimum position search operation described above. It is possible to search for a position to be detected and perform efficient power transmission at the position.

  And when the electromagnetic coupling position of the primary coil 5 and the secondary coil 7 is not the positional relationship in which the most efficient energy feeding is performed, the control unit 33 is set so as to have the positional relationship in which the most efficient energy feeding is performed. Thus, a position where the primary coil current for causing the predetermined dummy current I2d of the secondary coil 7 to flow is minimized is searched for, and the optimum relative position between the primary coil 5 and the secondary coil 7 can be obtained.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  INDUSTRIAL APPLICABILITY The power transmission device according to the present invention can be used as a power transmission device that can efficiently supply energy and has a simple configuration in a power transmission device that supplies power to an electronic device in a contactless manner.

It is a perspective view which shows the external appearance of the charging device which is the electric power transmission apparatus of one Embodiment of this invention. It is a perspective view of the XY drive mechanism part incorporated in the charging device of FIG. FIG. 2 is a main electric circuit diagram of an electric circuit unit built in the charging device of FIG. 1 and a charging circuit unit of an electromagnetically coupled camera. It is a top view of the primary coil integrated in the charging device of FIG. It is AA sectional drawing of FIG. It is a figure which shows the change of the charging pressure and charging current at the time of the charge to the battery for power supplies of the camera of FIG. FIG. 2 is a diagram illustrating an example of primary coil current change and secondary coil current change from a preliminary search operation of a primary coil position in the charging device of FIG. 1 through an optimal position search operation to a start of charging operation. When the secondary coil on the camera side and the primary coil on the charging device side in FIG. 1 are within a predetermined distance range and a predetermined dummy current is passed through the secondary coil, the secondary coil and the primary coil It is a figure which shows the change of the electric current which flows into the said primary coil with respect to a separation position. It is a figure which shows the change of the primary coil current with respect to the measurement timing pulse at the time of the preliminary | backup search operation | movement of FIG. It is a figure which shows the example of a change of the primary coil current with respect to the separation distance of a primary coil when a movement point changes as shown in FIG. 18 in the state which sent the predetermined dummy current to the secondary coil shown in FIG. It is a figure which shows the change of the X and Y-axis movement amount of the primary coil in the optimal position search operation state of FIG. 7, and the change of the electric current of a primary coil. 4 is a flowchart of a main routine of “charging process” by the charging device of FIG. 1. 13 is a flowchart of a subroutine “preliminary search process” called in the main routine of the charging process of FIG. 12. It is a figure which shows the flow (flow A) of the process of the specific example in the subroutine "preliminary search process" of FIG. 13 called by the main routine of FIG. FIG. 13 is a diagram showing a part of a processing flow (flow B) of a specific example in a subroutine “optimum position search processing” called in the main routine of FIG. 12. It is a figure which shows another part of the flow (flow B) of the process of the specific example in the subroutine "optimum position search process" called by the main routine of FIG. It is the figure which showed the movement locus | trajectory on the mounting base of the primary coil in the flow A of the preliminary | backup search operation | movement of FIG. It is a figure which shows the movement locus | trajectory on the mounting base of the primary coil in the flow B of the optimal position search operation | movement of FIG.

Explanation of symbols

1 ... Charging device (power transmission device)
5 ... Primary coil 6 ... Camera (electronic equipment)
7 ... Secondary coil 10 ... XY drive mechanism (moving means)
31 ... Current detection part (current detection means)
32 ... DC-AC conversion circuit section (supply means)
34 ... Induction voltage setting section (current control means)
37 ... Position determination unit (determination means)
39: Voltage detection unit (voltage detection means)
35 ... Movement control unit (movement control means)
I2d ... secondary coil side dummy current V1 ... primary coil side coupling induced voltage

Claims (4)

In power transmission devices that supply power to electronic devices in a contactless manner,
A primary coil that is magnetically coupled to a secondary coil provided in the electronic device;
Supply means for supplying current to the primary coil;
When the primary coil and the secondary coil are magnetically coupled, when a predetermined dummy current is supplied to the secondary coil, a dielectric voltage on the primary coil side corresponding to the dummy current is generated. Voltage detecting means for detecting;
When the generated dielectric voltage is smaller than the combined dielectric voltage generated when the primary coil and the secondary coil are most effectively magnetically coupled, the voltage of the primary coil becomes the combined dielectric voltage. Current control means for controlling the supply means to increase the current flowing through the primary coil,
Current detection means for detecting a current value supplied to the primary coil;
Determination means for determining the positional relationship between the primary coil and the secondary coil based on the detected current value flowing through the primary coil;
A power transmission device comprising: A moving means for moving the primary coil;
When the determining means determines that the positional relationship between the primary coil and the secondary coil is not the most suitable position for charging, the moving means is controlled to move the primary coil in an arbitrary direction. Movement control means;
2. The power transmission device according to claim 1, wherein the movement control unit moves the primary coil in an arbitrary direction by the moving unit so that a current value flowing through the primary coil is minimized. . The movement control means includes movement direction determination means for determining a movement direction of the primary coil by comparing current values of the primary coil detected by the current detection means at each movement position. Item 3. The power transmission device according to Item 2. The current control means is configured to charge the amount of current supplied from the supply means to the primary coil when it is determined that the positional relationship between the primary coil and the secondary coil is most suitable for charging. 4. The power transmission device according to claim 1, wherein the current transmission amount is switched to a current amount.

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