JP2013118736A - Non-contact electric power transmission apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact electric power transmission apparatus capable of increasing a transmission distance.SOLUTION: The non-contact electric power transmission apparatus includes a transmission device 20 with a primary coil 21 and an electric toothbrush with a secondary coil and a rectification circuit. The electric toothbrush includes an auxiliary coil not electrically connected with the rectification circuit. The primary coil 21 has a non-spiral wiring form in plan view.

Description

  The present invention includes a power transmission device having a primary coil, a power reception device having a secondary coil and a power feeding circuit, and contactless power provided that a current generated in the secondary coil is supplied to the power feeding circuit. The present invention relates to a transmission apparatus.

  The non-contact power transmission device of Patent Document 1 transmits power to the secondary coil by interlinking the magnetic flux of the primary coil with the secondary coil. The secondary battery is charged by supplying the current of the secondary coil to the power feeding circuit.

Japanese Patent No. 3416863

  In a non-contact power transmission device, it is desired to increase the transmission distance. Note that the non-contact power transmission device of Patent Document 1 does not particularly take into account increasing the transmission distance.

  The present invention has been made to solve the above-described problems, and provides a non-contact power transmission apparatus capable of increasing a transmission distance.

  The non-contact power transmission device of the present invention has a power transmission device having a primary coil, a power reception device having a secondary coil and a power feeding circuit, and supplies current generated in the secondary coil to the power feeding circuit The power receiving device has an auxiliary coil that is not electrically connected to the power feeding circuit, and the primary coil has a non-spiral wiring configuration.

  In this non-contact power transmission device, the first linear portion and the second linear portion in which the primary coils are parallel to each other, and the connection for connecting the first linear portion and the second linear portion to each other And connecting the end portion of the second linear portion and the end portion of the first linear portion opposite to the end portion of the first linear portion. Is preferred.

  The present invention provides a contactless power transmission device capable of increasing a transmission distance.

Sectional drawing which shows the cross-section of the state with which the electric toothbrush was mounted on the power transmission apparatus about the non-contact-type electric power transmission apparatus of 1st Embodiment of this invention. About the non-contact-type power transmission device of the embodiment, (a) is a plan view showing a planar structure of a primary coil and a magnetic sheet, and (b) is a cross section showing a sectional structure taken along the line AA of (a). Figure. The circuit diagram which shows a circuit structure about the non-contact-type electric power transmission apparatus of the embodiment. Sectional drawing which shows the cross-section of a part of power transmission device and an electric toothbrush about the non-contact-type electric power transmission apparatus of 2nd Embodiment of this invention. The graph which shows the relationship between load resistance and transmission efficiency about the non-contact-type electric power transmission apparatus of the embodiment. The graph which shows the relationship between the center distance and transmission efficiency about the non-contact-type electric power transmission apparatus of the embodiment. The top view which shows typically the planar structure of an auxiliary coil and a secondary coil about the non-contact-type electric power transmission apparatus of other embodiment of this invention. About the non-contact-type electric power transmission apparatus of other embodiment of this invention, (a) is sectional drawing which shows the cross-sectional structure of a primary coil, an auxiliary | assistant coil, a secondary coil, and a pot core, (b) is the planar structure of a pot core. FIG. The perspective view which shows the perspective structure of an EER core about the non-contact-type electric power transmission apparatus of other embodiment of this invention. Regarding the contactless power transmission device of another embodiment of the present invention, (a) is a sectional view showing a sectional structure of a primary coil, an auxiliary coil, a secondary coil, and an EE core, and (b) is a perspective view of the EE core. The perspective view which shows a structure. Sectional drawing which shows the cross-section of a primary coil, an auxiliary | assistant coil, a secondary coil, and a magnetic sheet about the non-contact-type electric power transmission apparatus of other embodiment of this invention. Sectional drawing which shows the cross-section of an auxiliary coil, a secondary coil, and a core about the non-contact-type electric power transmission apparatus of other embodiment of this invention. (A) is a top view which shows the form of the primary coil which has several linear parts, (b) is the primary coil which has several wave-like parts about the non-contact-type electric power transmission apparatus of other embodiment of this invention. The top view which shows a form, (c) is a top view which shows the form of the primary coil which has several bellows parts, (d) is the top view which shows the form of the primary coil which has several arc parts.

(First embodiment)
With reference to FIG. 1, the whole structure of the non-contact-type electric power transmission apparatus 10 is demonstrated.
The non-contact power transmission device 10 includes a power transmission device 20 having a primary coil 21 and an electric toothbrush 40 having a secondary coil 43. The power transmission device 20 transmits electric power to the secondary battery 46 through the secondary coil 43 of the electric toothbrush 40 by an electromagnetic induction method. The electric toothbrush 40 corresponds to a “power receiving device”.

Here, each direction about the non-contact-type electric power transmission apparatus 10 is defined as follows.
(A) The axial direction of the primary coil 21 of the power transmission device 20 is defined as “axial direction X1”.
(B) The longitudinal direction of the electric toothbrush 40 is defined as “axial direction X2”.
(C) Let the orthogonal direction of the axial direction X2 be the "width direction Y" in the front view of the electric toothbrush 40.

  The power transmission device 20 includes a housing 23 that constitutes a main body of the device 20 and a magnetic sheet 22 that suppresses leakage of magnetic flux of the primary coil 21. The magnetic sheet 22 is located between the bottom wall of the housing 23 and the primary coil 21 and on the opposite side of the electric toothbrush 40 with respect to the primary coil 21 in the axial direction X1 of the power transmission device 20. The primary coil 21 is formed as a planar coil having a circular shape in plan view. The length of each side of the magnetic sheet 22 is larger than the outer diameter of the primary coil 21.

  As shown in FIG. 2A, the primary coil 21 is formed as a planar coil having a non-spiral wiring configuration in plan view. The primary coil 21 has a plurality of linear portions 21A that are parallel to each other and a plurality of connection portions 21B that connect the ends of adjacent linear portions 21A. Each connection portion 21B is orthogonal to the straight portion 21A in plan view. In a pair of adjacent linear portions 21A, one linear portion 21A corresponds to a “first linear portion”, and the other linear portion 21A corresponds to a “second linear portion”.

  Non-spiral wiring forms include wiring forms other than a planar coil having a spiral shape in plan view. The spiral shape includes a shape in which a plurality of annular portions are formed by conductive wires. The annular portion includes a circular shape or a similar shape, a polygon shape or a similar shape.

  As shown in FIG. 2B, when a current is supplied to the primary coil 21, in a pair of adjacent linear portions 21A, the current direction of one linear portion 21A and the current of the other linear portion 21A Are opposite to each other. For this reason, the magnetic flux generated in each linear portion 21A strengthens each other between a pair of adjacent linear portions 21A.

  As shown in FIG. 1, the electric toothbrush 40 includes a main body case 41 held by a user, and an attachment 42 that can be attached to and detached from the main body case 41. The attachment 42 has a brush portion 42A in which a bristle bundle is implanted. The brush portion 42 </ b> A is located at the distal end portion of the attachment 42.

  The main body case 41 includes an auxiliary coil 44 that links with the magnetic flux of the primary coil 21, a secondary coil 43 that links with the magnetic flux of the auxiliary coil 44, and a core 45 formed of a magnetic material. In addition to this, a secondary battery 46 serving as a power source for the electric toothbrush 40 and an electric motor 47 for vibrating the attachment 42 are provided. The auxiliary coil 44, the secondary coil 43, the core 45, the secondary battery 46, and the electric motor 47 are located inside the main body case 41.

  The secondary coil 43 is formed as a cylindrical coil having a circular shape in plan view. That is, the plurality of circular portions constituting the secondary coil 43 have a structure in which they are stacked on each other in the axial direction X2.

  The auxiliary coil 44 is formed as a cylindrical coil having a circular shape in plan view. That is, the plurality of circular portions constituting the auxiliary coil 44 have a structure in which they are stacked on each other in the axial direction X2.

  The secondary coil 43 and the auxiliary coil 44 have a cylindrical core 45. The core 45 is located in the hollow part of the secondary coil 43 and the auxiliary coil 44. That is, the secondary coil 43 and the auxiliary coil 44 are configured as a cored coil having one common core 45.

The relationship between the coils 21, 43, and 44 is shown below.
(A) The outer diameter of the primary coil 21 is larger than the outer diameter of the secondary coil 43.
(B) The outer diameter of the primary coil 21 is larger than the outer diameter of the auxiliary coil 44.
(C) The outer diameter of the auxiliary coil 44 is larger than the outer diameter of the secondary coil 43.
(D) The diameter of the conductive wire of the primary coil 21 is larger than the diameter of the conductive wire of the secondary coil 43.
(E) The diameter of the conductive wire of the primary coil 21 is larger than the diameter of the conductive wire of the auxiliary coil 44.
(F) The diameter of the conductive wire of the auxiliary coil 44 is larger than the diameter of the conductive wire of the secondary coil 43.
(G) The number of turns of the primary coil 21 is larger than the number of turns of the secondary coil 43.
(H) The number of turns of the primary coil 21 is equal to the number of turns of the auxiliary coil 44.
(I) The auxiliary coil 44 and the secondary coil 43 are coaxial.
(J) One end of the auxiliary coil 44 is in contact with one end of the secondary coil 43.

  In relation to the above (D) to (H), the Q value of the auxiliary coil 44 is made larger than the Q value of the secondary coil 43. The above relationship (I) indicates that the coupling coefficient between the secondary coil 43 and the auxiliary coil 44 (hereinafter referred to as “power receiving coupling coefficient”) is compared with a configuration in which the auxiliary coil 44 and the secondary coil 43 are not coaxial. ) Is enlarged.

With reference to FIG. 3, the circuit configuration of the non-contact power transmission apparatus 10 will be described.
The power transmission device 20 includes a primary circuit 30 that controls power supplied to the primary coil 21. The electric toothbrush 40 includes a secondary circuit 50 that controls electric power transmitted from the power transmission device 20.

  The primary circuit 30 includes a transmission circuit 31 that supplies alternating power to the primary coil 21, a control unit 32 that controls the transmission circuit 31, a primary coil 21 connected to the transmission circuit 31, and a primary coil 21. And a capacitor 33 connected in series. The transmission circuit 31 has a plurality of transistors connected to the primary coil 21. The primary coil 21 and the capacitor 33 constitute a resonance circuit 34.

  The secondary circuit 50 includes an auxiliary coil 44 that forms a magnetic circuit with the primary coil 21, a secondary coil 43 that forms a magnetic circuit with the auxiliary coil 44, and alternating power generated in the secondary coil 43. And a rectifier circuit 53 for rectifying the power to DC power. In addition, a capacitor 52 connected in series to the auxiliary coil 44 is provided. The rectifier circuit 53 corresponds to a “feed circuit”.

  The rectifier circuit 53 includes a rectifier bridge formed by combining four diodes, and a capacitor that smoothes the current that has passed through the rectifier bridge. The auxiliary coil 44 and the capacitor 52 constitute a resonance circuit 51. The capacitance of the capacitor 52 is set so that the resonance frequency of the resonance circuit 51 matches the reference frequency FK.

  The rectifier circuit 53 is electrically connected to the secondary coil 43 and the secondary battery 46. On the other hand, the resonance circuit 51 is not electrically connected. For this reason, the impedance of the auxiliary coil 44 is reduced as compared with the configuration in which the resonance circuit 51 is electrically connected to the rectification circuit 53.

With reference to FIG. 3, the power transmission mode of the non-contact power transmission apparatus 10 will be described.
The control unit 32 of the power transmission device 20 supplies alternating power having the reference frequency FK to the primary coil 21 by controlling the transmission circuit 31. As a result, an alternating magnetic flux is generated in the primary coil 21.

  The auxiliary coil 44 generates alternating power and alternating magnetic flux of the reference frequency FK by interlinking with the alternating magnetic flux of the primary coil 21. At this time, the alternating power and the alternating magnetic flux generated in the auxiliary coil 44 are larger than the configuration in which the rectifier circuit 53 and the resonance circuit 51 are electrically connected. Further, since the Q value of the auxiliary coil 44 is higher than the Q value of the secondary coil 43, the alternating magnetic flux of the primary coil 21 does not link with the secondary coil 43 or slightly links with the secondary coil 43. .

  The secondary coil 43 generates alternating power by interlinking with the alternating magnetic flux of the auxiliary coil 44. The rectifier circuit 53 smoothes the alternating power of the secondary coil 43 and converts it into DC power, and supplies this DC power to the secondary battery 46.

(Effect of embodiment)
The non-contact power transmission device 10 of the present embodiment has the following effects.
(1) The auxiliary coil 44 of the non-contact power transmission device 10 is not electrically connected to the rectifier circuit 53. According to this configuration, as compared with the configuration in which the auxiliary coil 44 is electrically connected to the rectifier circuit 53, the current of the auxiliary coil 44 generated when the magnetic flux of the primary coil 21 is linked to the auxiliary coil 44, and Magnetic flux increases. That is, as compared with the configuration in which the magnetic flux of the primary coil 21 is linked to the secondary coil 43, the current and magnetic flux generated in the coil (auxiliary coil 44) in which the magnetic flux of the primary coil 21 is linked first in the electric toothbrush 40. Becomes larger. Thereby, since the electric current of the secondary coil 43 generated when the magnetic flux of the auxiliary coil 44 is linked to the secondary coil 43 increases, the transmission distance can be increased.

  (2) Since a planar coil having a circular shape in plan view has a configuration in which conductive wires are laminated in the radial direction, when a coil is manufactured by a winding machine or by manual work, a contact state between adjacent conductive wires in the radial direction It is required to work while maintaining the shape of the curved portion so that the is uniform over the entire coil.

  On the other hand, the primary coil 21 of the non-contact power transmission device 10 has a non-spiral planar wiring configuration in plan view, and is formed by a plurality of linear portions 21A and a plurality of connection portions 21B. That is, unlike the circular coil having the circular shape, it does not have a spiral portion.

  For this reason, at the time of manufacturing the primary coil 21, it is not necessary to proceed with the work while maintaining the shape of the curved portion so that the contact state between the conductive wires adjacent in the radial direction is uniform over the entire coil. That is, since the accuracy required for the work at the time of manufacture is lower than that of the flat coil having the circular shape, labor for manufacturing is reduced.

  Further, since the primary coil 21 has a form in which a gap is formed between a pair of adjacent linear portions 21A, the tolerance of the wiring position of the linear portion 21A and the tolerance of the angle with respect to the wiring direction can be increased. . On the other hand, since the planar coil having the circular shape has a form in which the conductive wires are in contact with each other in the radial direction, the tolerances such as the wiring positions of the conductive wires need to be smaller than the tolerance of the primary coil 21 with respect to the linear portion 21A. is there. And even from the comparison of this point, it can be confirmed that the primary coil 21 has a configuration in which labor for manufacturing is reduced as compared with the planar coil having the circular shape.

  (3) The primary coil 21 of the non-contact power transmission apparatus 10 includes a linear portion 21A that is parallel to each other and a connection portion 21B that connects the ends of adjacent linear portions 21A to each other. According to this configuration, when electric power is supplied to the primary coil 21, the current directions of the adjacent linear portions 21A are opposite to each other, so that the magnetic forces are strengthened between the adjacent linear portions 21A. For this reason, the transmission efficiency of the electric power from the primary coil 21 to the auxiliary coil 44 is improved.

  (4) The auxiliary coil 44 and the secondary coil 43 of the non-contact power transmission apparatus 10 are coaxial. According to this structure, compared with the structure in which the auxiliary coil 44 and the secondary coil 43 do not have a coaxial, a receiving coupling coefficient becomes large. For this reason, the current of the secondary coil 43 generated via the auxiliary coil 44 increases.

  (5) The auxiliary coil 44 and the secondary coil 43 of the non-contact power transmission device 10 have a circular shape in plan view. According to this configuration, the cost of the auxiliary coil 44 and the secondary coil 43 is reduced as compared with a configuration using a coil having a shape other than a circle in plan view, for example, a triangle or a quadrangle.

  (6) The auxiliary coil 44 of the non-contact power transmission device 10 has a core 45. According to this configuration, the amount of magnetic flux leakage between the primary coil 21 and the auxiliary coil 44 is reduced compared to the configuration in which the core 45 is omitted from the auxiliary coil 44.

  (7) The secondary coil 43 of the non-contact power transmission apparatus 10 has a core 45. According to this configuration, compared to a configuration in which the core 45 is omitted from the secondary coil 43, the amount of magnetic flux leakage between the auxiliary coil 44 and the secondary coil 43 is reduced.

  (8) The auxiliary coil 44 and the secondary coil 43 of the non-contact power transmission apparatus 10 have a common core 45. According to this configuration, the number of cores can be reduced as compared with the configuration in which the core is individually provided for the auxiliary coil 44 and the secondary coil 43.

  (9) The auxiliary coil 44 and the secondary coil 43 of the non-contact power transmission apparatus 10 have a core 45 in the hollow portion. According to this configuration, the physique of the electric toothbrush 40 can be reduced as compared with a configuration using a core that covers the auxiliary coil 44 and the secondary coil 43 from the outside in the width direction Y.

(Second Embodiment)
The contactless power transmission device 10 of the present embodiment shown in FIG. 4 has the following differences as main differences from the contactless power transmission device 10 of the first embodiment shown in FIG. That is, the auxiliary coil 44 and the secondary coil 43 of the electric toothbrush 40 of the first embodiment are coaxial. On the other hand, the auxiliary coil 44 and the secondary coil 43 of the electric toothbrush 40 of the present embodiment have axes that are parallel to each other. In the following, details of differences from the contactless power transmission device 10 of the first embodiment will be described, and the same reference numerals will be given to components common to the first embodiment, and a part or all of the description will be omitted. To do.

  The electric toothbrush 40 has a core 60 formed of a magnetic material instead of the core 45 of FIG. The core 60 includes a columnar first core 61 inserted into the hollow portion of the auxiliary coil 44 and a columnar second core 62 inserted into the hollow portion of the secondary coil 43.

  The second core 62 protrudes from the end surface of the first core 61 in the axial direction X2 of the electric toothbrush 40. The central axis of the second core 62 is eccentric with respect to the central axis of the first core 61. For this reason, the central axis of the secondary coil 43 is eccentric with respect to the central axis of the auxiliary coil 44.

The relationship between the coils 21, 43, and 44 is shown below. The inter-coil distance G <b> 1 indicates the distance between the end of the auxiliary coil 44 and the end of the secondary coil 43 in the axial direction X <b> 2 of the electric toothbrush 40. The inter-coil distance G2 indicates the distance between the end of the auxiliary coil 44 and the end of the primary coil 21 in the axial direction X2 of the electric toothbrush 40.
(A) The axis JA of the secondary coil 43 and the axis JB of the auxiliary coil 44 are parallel to each other.
(B) One end of the auxiliary coil 44 is not in contact with one end of the secondary coil 43.
(C) The inter-coil distance G1 is smaller than the inter-coil distance G2.

  In the relationship (A), the power receiving coupling coefficient is made smaller than the configuration in which the secondary coil 43 and the auxiliary coil 44 are coaxial. The relationship (B) is such that the power receiving coupling coefficient is reduced as compared with the configuration in which one end of the secondary coil 43 is in contact with one end of the auxiliary coil 44.

The power receiving coupling coefficient is the distance between the axis JA of the secondary coil 43 and the axis JB of the auxiliary coil 44 in the radial direction of the secondary coil 43 and the auxiliary coil 44 (hereinafter, “radial distance R”), and the inter-coil distance G1. Correlation with each of the above. The specific relationship is shown below.
(A) The power receiving coupling coefficient decreases as the radial distance R increases.
(B) The power receiving coupling coefficient decreases as the inter-coil distance G1 increases.

  For this reason, by changing at least one of the radial distance R and the inter-coil distance G1 in the design stage of the electric toothbrush 40, the magnitude of the power receiving coupling coefficient can be adjusted according to various design conditions.

  The relationship between the load resistance of the secondary coil 43 and the transmission efficiency will be described with reference to FIG. The vertical axis in FIG. 5 indicates the transmission efficiency, that is, the ratio between the current supplied to the primary coil 21 and the current generated in the secondary coil 43 due to the same current. The horizontal axis in FIG. 5 indicates the magnitude of the load resistance.

  Examples of the load resistance include the rectifier circuit 53, the secondary battery 46, and the electric motor 47 in FIG. Assuming that the voltage of the primary coil 21 is constant, the current supplied to the rectifier circuit 53, the secondary battery 46, and the electric motor 47 decreases as the load resistance increases.

Here, as a configuration defined by the relationship between the secondary coil 43 and the auxiliary coil 44, a “coaxial configuration”, a “first parallel axis configuration”, and a “second parallel axis configuration” are respectively defined as follows.
(A) The coaxial configuration indicates a configuration in which the secondary coil 43 and the auxiliary coil 44 are coaxial, and the secondary coil 43 is in contact with the auxiliary coil 44. The power reception coupling coefficient of the coaxial configuration is larger than the power reception coupling coefficient of the first parallel shaft configuration.
(B) The first parallel axis configuration indicates a configuration in which the axis JA of the secondary coil 43 and the axis JB of the auxiliary coil 44 are parallel to each other and the secondary coil 43 is not in contact with the auxiliary coil 44.
(C) The second parallel axis configuration is such that the axis JA of the secondary coil 43 and the axis JB of the auxiliary coil 44 are parallel to each other, the secondary coil 43 does not contact the auxiliary coil 44, and the first parallel axis configuration. A configuration with a smaller power receiving coupling coefficient is shown.

Each curve L1-L3 of FIG. 5 shows the following relationships, respectively.
(A) A curve L1 shows the relationship between the load resistance of the coaxial configuration and the transmission efficiency.
(B) Curve L2 shows the relationship between the load resistance and transmission efficiency of the first parallel shaft configuration.
(C) Curve L3 shows the relationship between the load resistance and the transmission efficiency of the second parallel axis configuration.

The relationship between the load resistance and transmission efficiency confirmed from the curves L1 to L3 is shown below. Hereinafter, the maximum transmission efficiency in an arbitrary curve is referred to as “maximum transmission efficiency”, and the load resistance corresponding to the maximum transmission efficiency is referred to as “maximum load resistance”.
(A) The maximum load resistance of the curve L2 is smaller than the maximum load resistance of the curve L1.
(B) The maximum load resistance of the curve L3 is smaller than the maximum load resistance of the curve L2.

  In the electric toothbrush 40, the relationship between the curves L1 to L3 is grasped in advance by a test or the like so that the transmission coupling suitable for the magnitude of the load resistance connected to the secondary coil 43 is obtained. A coefficient can be set. For example, when the load resistance is constant, a configuration in which the transmission efficiency among the curves L1 to L3 is maximized with respect to the load resistance can be selected. In addition, as a case where load resistance is a fixed magnitude | size, the case where the charge of the secondary battery 46 is performed with a fixed electric current is mentioned.

  With reference to FIG. 6, the relationship between the inter-axis distance and the transmission efficiency will be described. The vertical axis in FIG. 6 indicates transmission efficiency. The horizontal axis in FIG. 6 indicates the inter-axis distance, that is, the distance between the axis JC of the primary coil 21 and the axis JB of the auxiliary coil 44 in the width direction Y of the electric toothbrush 40 in FIG. In addition, the non-contact power transmission device 10 of FIG. 3 shows a state in which the distance between the axes is “0”.

Each curve K1-K3 of FIG. 6 shows the following relationships, respectively.
(A) Curve K1 shows the relationship between the axial distance of a coaxial structure, and transmission efficiency.
(B) A curve K2 shows the relationship between the inter-axis distance and the transmission efficiency of the first parallel shaft configuration.
(C) Curve K3 shows the relationship between the inter-axis distance and the transmission efficiency of the second parallel axis configuration.

  FIG. 6A shows a relationship between the inter-axis distance and the transmission efficiency in the configuration in which the inter-coil distance G2 is small. FIG. 6B shows the relationship between the inter-axis distance and the transmission efficiency in the configuration in which the inter-coil distance G2 is larger than that in FIG. FIG. 6C shows the relationship between the inter-axis distance and the transmission efficiency in the configuration in which the inter-coil distance G2 is larger than that in FIG. 6B.

  The relationship between the interaxial distances and the transmission efficiencies (curves K1 to K3) of the coaxial configuration, the first parallel axis configuration, and the second parallel axis configuration show almost the same tendency at the same inter-coil distance G2.

  In the electric toothbrush 40, the power receiving coupling coefficient can be set so that transmission efficiency suitable for the inter-coil distance G2 can be obtained by grasping the relationship between the curves K1 to K3 in advance by a test or the like. For example, when the inter-coil distance G2 is a constant size, a configuration in which the transmission efficiency among the curves K1 to K3 is the maximum with respect to the size of the inter-coil distance G2 can be selected.

(Effect of embodiment)
In addition to the effects (1) to (3) and (5) to (9) produced by the contactless power transmission apparatus 10 of the first embodiment, the contactless power transmission apparatus 10 of the present embodiment has the following effects. Play.

  (10) The non-contact power transmission apparatus 10 includes a secondary coil 43 and an auxiliary coil 44 that are individually formed. According to this configuration, the distance in the width direction Y between the axis JA of the secondary coil 43 and the axis JB of the auxiliary coil 44 in the width direction Y of the electric toothbrush 40 is adjusted in the design stage of the contactless power transmission device 10. be able to. In addition, the interval between the secondary coil 43 and the auxiliary coil 44 can be adjusted in the axial direction X2 of the electric toothbrush 40. For this reason, the power receiving coupling coefficient suitable for the magnitude of the load resistance or the distance between the axes can be selected.

(Other embodiments)
The present invention includes embodiments other than the first and second embodiments. Hereinafter, the modification of each embodiment as other embodiment of the present invention is shown. The following modifications can be combined with each other.

In the secondary coil 43 of the first embodiment (FIG. 1), one end is in contact with the auxiliary coil 44. On the other hand, the modified secondary coil 43 is not in contact with the auxiliary coil 44.
-The secondary coil 43 and the auxiliary coil 44 of 1st Embodiment (FIG. 1) have a coaxial. On the other hand, the secondary coil 43 and the auxiliary coil 44 of the modified example have axes parallel to each other.

  In the secondary coil 43 of the second embodiment (FIG. 4), one end is not in contact with the auxiliary coil 44. On the other hand, the modified secondary coil 43 has a configuration in which one end portion is in contact with the auxiliary coil 44.

The secondary coil 43 and the auxiliary coil 44 of the second embodiment (FIG. 4) have axes that are parallel to each other. On the other hand, the secondary coil 43 and the auxiliary coil 44 of the modified example have the same axis.
In the first and second embodiments (FIGS. 1 and 4), the secondary coil 43 and the auxiliary coil 44 are formed as cylindrical coils. On the other hand, at least one of the auxiliary coil 44 and the secondary coil 43 of the modification is formed as a planar coil.

  The outer diameter of the auxiliary coil 44 in the first and second embodiments (FIGS. 1 and 4) is larger than the outer diameter of the secondary coil 43. On the other hand, the outer diameter of the auxiliary coil 44 of the modification has a size equal to or smaller than the outer diameter of the secondary coil 43.

  The number of turns of the auxiliary coil 44 in the first and second embodiments (FIGS. 1 and 4) is larger than the number of turns of the secondary coil 43. On the other hand, the number of turns of the auxiliary coil 44 of the modification has a size equal to or smaller than the number of turns of the secondary coil 43.

  In the first and second embodiments (FIGS. 1 and 4), the number of turns of the primary coil 21 and the number of turns of the auxiliary coil 44 are equal to each other. On the other hand, the number of turns of the primary coil 21 and the number of turns of the auxiliary coil 44 are different from each other.

  The diameter of the conductive wire of the auxiliary coil 44 in the first and second embodiments (FIGS. 1 and 4) is larger than the diameter of the conductive wire of the secondary coil 43. On the other hand, the diameter of the conductive wire of the auxiliary coil 44 of the modification has a size equal to or smaller than the diameter of the conductive wire of the secondary coil 43.

  The cores 45 and 60 of the first and second embodiments (FIGS. 1 and 4) are located in the hollow portions of the auxiliary coil 44 and the secondary coil 43. On the other hand, the cores 45 and 60 of the modified example omit a portion corresponding to the auxiliary coil 44 (first core 61) or a portion corresponding to the secondary coil 43 (second core 62).

  The auxiliary coil 44 and the secondary coil 43 of the first and second embodiments (FIGS. 1 and 4) have cores 45 and 60. On the other hand, the cores 45 and 60 are omitted from the auxiliary coil 44 and the secondary coil 43 of the modification.

The auxiliary coil 44 and the secondary coil 43 of the first and second embodiments (FIGS. 1 and 4) have a cylindrical shape. On the other hand, the auxiliary coil 44 and the secondary coil 43 of the modification have a shape shown in FIG.
(A1) As shown in FIG. 7A, the auxiliary coil 44 has a quadrangular shape in plan view. The secondary coil 43 has a circular shape in plan view.
(A2) As shown in FIG. 7B, the auxiliary coil 44 has a quadrangular shape in plan view. The secondary coil 43 has a quadrangle in plan view.
(A3) As shown in FIG. 7C, the auxiliary coil 44 has a circular shape in plan view. The secondary coil 43 has a quadrangle in plan view.

  The secondary coil 43 and the auxiliary coil 44 in the modified examples of the configurations (A1) to (A3) have axes parallel to each other. On the other hand, the auxiliary coil 44 and the secondary coil 43 in the modified examples of the configurations (A1) to (A3) have the same axis.

-The auxiliary | assistant coil 44 and the secondary coil 43 in the modification of the structure of said (A1)-(A3) have the following shapes.
(B1) The auxiliary coil 44 has a triangular shape, a square shape, or an elliptical shape in plan view.
(B2) The secondary coil 43 has any one of a triangle, a quadrangle, and an ellipse in plan view.
(B3) The auxiliary coil 44 has a coil having any one of the above shapes (B1), and the secondary coil 43 has a coil having any one of the above shapes (B2).

  The electric toothbrush 40 of the first and second embodiments (FIGS. 1 and 4) has cores 45 and 60. On the other hand, the electric toothbrush 40 of a modification has one of the following configurations (C1) to (C4).

  (C1) As shown in FIG. 8A, the auxiliary coil 44 has a pot core 70 instead of the cores 45 and 60. The secondary coil 43 is located in a space closer to the primary coil 21 than the auxiliary coil 44 in the axial direction X2. The secondary coil 43 has a circular planar coil shape.

  As shown in FIG. 8B, the pot core 70 includes a bottom wall 71 that covers the entire auxiliary coil 44 from the axial direction X2 of the electric toothbrush 40, an inner wall 72 that is inserted into a hollow portion of the auxiliary coil 44, and an electric motor. And an outer wall 73 covering the auxiliary coil 44 from the width direction Y of the toothbrush 40.

  According to this configuration, since the pot core 70 has the bottom wall 71 and the outer wall 73, the magnetic flux leakage between the primary coil 21 and the auxiliary coil 44 compared to the configuration in which the auxiliary coil 44 has the cores 45 and 60. The amount is reduced.

  (C2) The auxiliary coil 44 of the modified example of (C1) has an EER core 80 shown in FIG. 9 instead of the pot core 70. The EER core 80 includes a rectangular bottom wall 81 that covers a part of the auxiliary coil 44 in FIG. 8A from the axial direction X2 of the electric toothbrush 40, and a cylindrical inner wall 82 that is inserted into the hollow portion of the auxiliary coil 44. And a pair of outer walls 83 surrounding the auxiliary coil 44 from the width direction Y of the electric toothbrush 40. Each outer wall 83 has an arc-shaped inner surface.

  According to this configuration, since the EER core 80 has the bottom wall 81 and the outer wall 83, the magnetic flux between the primary coil 21 and the auxiliary coil 44 is reduced compared to the configuration in which the auxiliary coil 44 has the cores 45 and 60. Leakage is reduced.

  (C3) As shown in FIG. 10A, the auxiliary coil 44 has an EE core 90 instead of the cores 45 and 60. The secondary coil 43 is located in a space closer to the primary coil 21 than the auxiliary coil 44 in the axial direction X2 of the electric toothbrush 40. A part of the secondary coil 43 is inserted into the EE core 90.

  As shown in FIG. 10B, the EE core 90 is inserted into a rectangular bottom wall 91 that covers a part of the auxiliary coil 44 from the axial direction X <b> 2 of the electric toothbrush 40 and a hollow portion of the auxiliary coil 44. A rectangular inner wall 92 and a pair of rectangular outer walls 93 covering the auxiliary coil 44 from the width direction Y of the electric toothbrush 40 are provided.

  According to this configuration, since the EE core 90 has the bottom wall 91 and the outer wall 93, the magnetic flux between the primary coil 21 and the auxiliary coil 44 can be reduced compared to the configuration in which the auxiliary coil 44 has the cores 45 and 60. Leakage is reduced. Further, since the secondary coil 43 is inserted into the outer wall 93 of the EE core 90, the leakage of magnetic flux between the auxiliary coil 44 and the secondary coil 43 compared to a configuration in which the secondary coil 43 is not inserted into the outer wall 93. The amount is reduced.

  (C4) As shown in FIG. 11, the secondary coil 43 includes a magnetic sheet 100 instead of the cores 45 and 60. The auxiliary coil 44 is located in a space closer to the primary coil 21 than the secondary coil 43 in the axial direction X2 of the electric toothbrush 40. The outer diameter of the auxiliary coil 44 is larger than the outer diameter of the secondary coil 43.

-The auxiliary coil 44 and the secondary coil 43 in the modification of the structure of said (C1)-(C4) have a coaxial.
The secondary coil 43 and the auxiliary coil 44 in the modified examples of the configurations (C1) to (C3) have a configuration in which end portions of the respective coils are in contact with each other.

The auxiliary coil 44 and the secondary coil 43 in the modified example of the configuration (C4) have a configuration in which the respective end portions are not in contact with each other.
The auxiliary coil 44 and the secondary coil 43 of the first and second embodiments (FIGS. 1 and 4) have cores 45 and 60. On the other hand, the auxiliary coil 44 and the secondary coil 43 of the modified example have a core 110 shown in FIG.

  The core 110 includes a first core 111 that is inserted into the hollow portion of the auxiliary coil 44 and a second core 112 that is inserted into the hollow portion of the secondary coil 43. The first core 111 and the second core 112 are individually formed. The second core 112 is fixed to the end surface of the first core 111 in the axial direction X2 of the electric toothbrush 40. A magnetic material is used as the material of the first core 111 and the second core 112. The permeability of the second core 112 is smaller than the permeability of the first core 111.

  The non-contact power transmission apparatus 10 having the core 110 can increase the Q value of the auxiliary coil 44 by increasing the magnetic permeability of the first core 111. When the Q value of the auxiliary coil 44 is increased, it is not necessary to increase the Q value of the secondary coil 43, so that the second core 112 having a low magnetic permeability is allowed to be used. When the second core 112 having a low magnetic permeability is used, the cost for the core is reduced.

  As described above, the non-contact power transmission device 10 is suitable for the auxiliary coil 44 and the secondary coil 43 from the viewpoint of Q value and cost because the first core 111 and the second core 112 are individually formed. A core can be selected.

  The primary coil 21 of the first and second embodiments (FIGS. 1 and 4) is formed of a plurality of linear portions 21A and a plurality of connection portions 21B as an example of a non-spiral wiring configuration. On the other hand, the modified primary coil has any of the following forms (D1), (D2), (E1) to (E3), (F1) to (F3), and (G1) to (G3). Have.

  (D1) As shown in FIG. 13A, the primary coil 21 has a plurality of linear portions 21A parallel to each other. The plurality of straight line portions 21 </ b> A individually receive power from the power supply of the power transmission device 20.

  (D2) The primary coil 21 as a modified example of the form (D1) is omitted except for one linear portion 21A among the plurality of linear portions 21A, and has the remaining one linear portion 21A. One straight line portion 21 </ b> A receives power from the power supply of the power transmission device 20.

  (E1) As shown in FIG. 13B, the primary coil 24 has a plurality of wave-like portions 24A that are parallel to each other and a plurality of connection portions 24B that connect the adjacent wave-like portions 24A to each other. In the pair of adjacent wave portions 24A, one wave portion 24A corresponds to a “first linear portion”, and the other wave portion 24A corresponds to a “second linear portion”.

  (E2) The primary coil 24 as a modification of the form (E1) described above has a plurality of connection portions 24B and a plurality of wavy portions 24A. The plurality of wavy portions 24A individually receive power from the power source of the power transmission device 20.

  (E3) The primary coil 24 as a modified example of the form of (E2) is omitted except for one wavy portion 24A of the plurality of wavy portions 24A, and has the remaining one wavy portion 24A. One wavy portion 24 </ b> A receives power from the power source of the power transmission device 20.

  (F1) As shown in FIG. 13C, the primary coil 25 has a plurality of bellows portions 25A that are parallel to each other and a plurality of connection portions 25B that connect the adjacent bellows portions 25A to each other. In a pair of adjacent bellows portions 25A, one bellows portion 25A corresponds to a “first linear portion” and the other bellows portion 25A corresponds to a “second linear portion”.

  (F2) The primary coil 25 as a modification of the form (F1) has a plurality of connection portions 25B and a plurality of bellows portions 25A. The plurality of bellows portions 25A individually receive power from the power source of the power transmission device 20.

  (F3) The primary coil 25 as a modification of the form of (F2) is omitted except for one bellows portion 25A of the plurality of bellows portions 25A, and has the remaining one bellows portion 25A. One bellows portion 25 </ b> A receives power from the power source of the power transmission device 20.

  (G1) As shown in FIG. 13 (d), the primary coil 26 has a plurality of arc portions 26A that are parallel to each other and a plurality of connection portions 26B that connect the adjacent arc portions 26A to each other. In one set of adjacent arc portions 26A, one arc portion 26A corresponds to a “first linear portion”, and the other arc portion 26A corresponds to a “second linear portion”.

  (G2) The primary coil 26 as a modified example of the above-described form (G1) omits the plurality of connection portions 26B and has a plurality of arc portions 26A. The plurality of arc portions 26A individually receive power from the power source of the power transmission device 20.

  (G3) The primary coil 26 as a modification of the form of (G2) is omitted except for one arc portion 26A of the plurality of arc portions 26A, and has the remaining one arc portion 26A. One arc portion 26 </ b> A receives power from the power source of the power transmission device 20.

  -The modification of the form of said (D1), (E2), (F2), and (G2) is one set of adjacent linear parts, that is, one set of adjacent linear parts 21A, one set of adjacent wavy shapes With respect to the portion 24A, the adjacent set of bellows portions 25A, and the adjacent set of arc portions 26A, currents in opposite directions are supplied to one linear portion and the other linear portion. Thereby, there exists an effect which strengthens magnetic flux between 1 set of linear parts like 21 A of 1 set of adjacent linear parts in 1st and 2nd embodiment.

  -The modification of the form of said (D1), (D2), (E1)-(E3), (F1)-(F3), and (G1)-(G3) is toward the axial direction X1 of the power transmission apparatus 20 And has a bent portion.

  -The electric toothbrush 40 of 1st and 2nd embodiment (FIG. 1 and FIG. 4) has the secondary battery 46. FIG. On the other hand, in the modified electric toothbrush 40, the secondary battery 46 is omitted. The secondary coil 43 of the electric toothbrush 40 supplies current directly to the electric motor 47. The power transmission device 20 transmits electric power to the electric toothbrush 40 when the electric motor 47 is driven.

  The present invention can also be applied to other power receiving devices other than the electric toothbrush 40 exemplified in the first and second embodiments (FIGS. 1 and 4). Examples of other power receiving devices include an electric razor, a nose hair cutter, and a dryer. This power receiving apparatus has a configuration according to the first and second embodiments. Moreover, the effect according to the effect of 1st and 2nd embodiment is show | played.

  DESCRIPTION OF SYMBOLS 10 ... Non-contact-type electric power transmission apparatus, 20 ... Power transmission apparatus, 21 ... Primary coil, 21A ... Linear part (1st linear part, 2nd linear part), 21B ... Connection part, 24 ... Primary coil, 24A ... Wavy portion (first linear portion, second linear portion), 24B ... connection portion, 25 ... primary coil, 25A ... bellows portion (first linear portion, second linear portion), 25B ... connection portion , 26 ... primary coil, 26A ... arc portion (first linear portion, second linear portion), 26B ... connection portion, 40 ... electric toothbrush (power receiving device), 43 ... secondary coil, 44 ... auxiliary coil, 53: Rectifier circuit (feed circuit).

The power transmission device 20 includes a housing 23 that constitutes a main body of the device 20 and a magnetic sheet 22 that suppresses leakage of magnetic flux of the primary coil 21. The magnetic sheet 22 is located between the bottom wall of the housing 23 and the primary coil 21 and on the opposite side of the electric toothbrush 40 with respect to the primary coil 21 in the axial direction X1 of the power transmission device 20 . The length of each side of the magnetic sheet 22 is larger than the outer diameter of the primary coil 21.

The relationship between the coils 21, 43, and 44 is shown below. The direction along the straight portion 21A of the primary coil 21 is defined as “vertical direction”, and the direction orthogonal to the vertical direction and the axial direction X1 is defined as “lateral direction”. Further, the dimension between the linear part 21A on the most lateral side in the horizontal direction and the linear part 21A on the othermost side in the lateral direction is referred to as “the lateral dimension of the primary coil 21”.
(A) The longitudinal dimension of the primary coil 21 is larger than the outer diameter of the secondary coil 43.
(B) The horizontal dimension of the primary coil 21 is larger than the outer diameter of the secondary coil 43.
( C ) The longitudinal dimension of the primary coil 21 is larger than the outer diameter of the auxiliary coil 44.
(D) The lateral dimension of the primary coil 21 is larger than the outer diameter of the auxiliary coil 44.
( E ) The outer diameter of the auxiliary coil 44 is larger than the outer diameter of the secondary coil 43.
( F ) The diameter of the conductive wire of the primary coil 21 is larger than the diameter of the conductive wire of the secondary coil 43.
( G ) The diameter of the conductive wire of the primary coil 21 is larger than the diameter of the conductive wire of the auxiliary coil 44.
( H ) The diameter of the conductive wire of the auxiliary coil 44 is larger than the diameter of the conductive wire of the secondary coil 43 .
(I) The auxiliary coil 44 and the secondary coil 43 are coaxial.
(J) One end of the auxiliary coil 44 is in contact with one end of the secondary coil 43.

Claims (2)

A non-contact power transmission apparatus provided with a power transmission apparatus having a primary coil, a power reception apparatus having a secondary coil and a power supply circuit, and supplying a current generated in the secondary coil to the power supply circuit In
The power receiving device has an auxiliary coil that is not electrically connected to the power feeding circuit;
The primary coil has a non-spiral wiring configuration. A non-contact power transmission device. The contactless power transmission device according to claim 1,
The primary coil includes a first linear portion and a second linear portion that are parallel to each other, and a connection portion that connects the first linear portion and the second linear portion to each other;
In addition, the connection portion connects the end portion of the second linear portion and the end portion of the first linear portion, which face the end portion of the first linear portion, to each other. Contact power transmission device.