JP7131282B2 - Wireless power supply system - Google Patents

Description

The technical field of the present specification relates to wireless power supply systems.

2. Description of the Related Art In recent years, research and development have been actively carried out on techniques for wirelessly supplying power to mobile communication terminals such as smartphones and other electronic devices. Technologies for wirelessly supplying power to electronic devices for vehicles have also been developed.

For example, Patent Literature 1 discloses a technique for wirelessly supplying power to an operation unit of an air-conditioning register. By arranging a power transmission coil around the air-conditioning register, power is supplied to the LED of the operation unit that adjusts the wind direction of the air-conditioning register (see FIG. 8 of Patent Document 1).

JP 2016-2921 A

However, there are many kinds of on-vehicle parts to be mounted on the vehicle. Therefore, from a design point of view, when the number of parts increases, it is difficult to arrange in-vehicle parts in a limited space. Therefore, it is desired to develop a wireless power supply system that can be placed in a limited space and that can effectively supply power to an electronic device to which power is to be supplied.

The problem to be solved by the technique of the present specification is to provide a wireless power supply system that can be placed in a limited space and that can effectively supply power to an electronic device to which power is supplied.

A wireless power supply system according to a first aspect includes an air-core power transmission coil, a power reception coil, a device surrounded by a housing, and an electronic component driven by power from the power reception coil. The housing has a support member on the outer wall of the housing. The power transmission coil is fixed to the support member of the housing. The receiving coil is arranged inside the housing or on the surface of the housing. The support member does not completely cover the power transmission coil, and at least a portion of the power transmission coil is in contact with the atmosphere.

This wireless power supply system can arrange the power transmission coil in a limited space such as the inside of a vehicle, and can effectively supply power to an electronic device to which power is to be supplied. Work is easy when a worker actually assembles it into an automobile. In addition, it is possible to reliably position the power transmission coil and the housing relative to each other. Therefore, there is almost no possibility that the relative positional relationship between the power transmitting coil and the power receiving coil varies from lot to lot.

This specification provides a wireless power supply system that can be placed in a limited space and that can effectively supply power to an electronic device to which power is supplied.

FIG. 2 is a schematic diagram showing the interior of the vehicle according to the first embodiment; FIG. 1 is a schematic diagram showing a schematic configuration of a wireless power feeding system according to a first embodiment; FIG. FIG. 10 is a diagram (part 1) showing a fixed state between the power transmission coil and the housing in the first embodiment; FIG. 10 is a diagram (part 2) showing a fixed state between the power transmission coil and the housing in the first embodiment; FIG. 5 is a partial cross-sectional view showing a part of the VV cross section of FIG. 4; It is a figure which shows the shape of the power transmission coil in 1st Embodiment. It is a perspective view which shows the positional relationship of the receiving coil and light-emitting device in 1st Embodiment. 1 is a diagram schematically showing a circuit of a wireless power feeding system according to a first embodiment; FIG. It is a figure for demonstrating the attachment of the power transmission coil and housing|casing in the modification of 1st Embodiment. FIG. 10 is a front view showing the shape of the power transmission coil of the second embodiment; FIG. 11 is a view of the power transmission coil viewed from the direction of arrow J1 in FIG. 10; FIG. 11 is a schematic configuration diagram of a wireless power feeding system according to a third embodiment; FIG. 11 is a layout diagram of power transmitting coils and power receiving coils of the third embodiment; FIG. 11 is a diagram (part 1) showing a modification of the power transmission coil of the third embodiment; FIG. 12 is a diagram (part 2) showing a modification of the power transmission coil of the third embodiment; FIG. 12 is a diagram (part 3) showing a modification of the power transmission coil of the third embodiment; FIG. 11 is a schematic configuration diagram of a wireless power feeding system in a modified example of the third embodiment;

Specific embodiments will be described below by taking a wireless power feeding system as an example. However, the technology herein is not limited to these embodiments.

(First embodiment)
1. In-Vehicle Parts FIG. 1 is a schematic diagram showing the interior of a vehicle. As shown in FIG. 1, there is an instrument panel IP in front of the driver's seat of the vehicle. The instrument panel IP is provided with a plurality of air conditioning registers CA1. The air conditioning register CA1 has a housing 160 and a knob N1 for the user to adjust the wind direction. The knob N1 is capable of emitting light. This is because the user can easily grasp the position of the knob N1 even when the inside of the vehicle is dark.

2. Wireless Power Supply System FIG. 2 is a schematic diagram showing a schematic configuration of the wireless power supply system 100 of the first embodiment. The wireless power feeding system 100 performs magnetic field coupling type wireless power feeding. As shown in FIG. 2, the wireless power feeding system 100 includes one power transmitting coil 110, two power receiving coils 120, a power transmitting circuit 130, a power receiving circuit 140, a light emitting device 150, and a housing 160. have. As shown in FIG. 2, the power transmission coil 110 has a connecting portion 113 that connects two regions surrounded by the coil.

The resonance frequency of the wireless power feeding system 100 is 6.78 MHz. Therefore, the frequency of the current flowing through power transmitting coil 110 and power receiving coil 120 is 6.78 MHz. The resonance frequency of the LC circuit of power transmission coil 110 is also 6.78 MHz. The resonance frequency of the LC circuit of power receiving coil 120 is also 6.78 MHz. The frequency of the current that the power transmission circuit 130 supplies to the power transmission coil 110 is also 6.78 MHz. In practice, it may deviate slightly from the target frequency. In addition, although 6.78 MHz is given as an example, a resonance frequency of 500 kHz or more and 15 MHz or less may be adopted. Moreover, you may use resonance frequencies other than the above.

Power transmission coil 110 is a coil for forming a magnetic field around power reception coil 120 . The power transmission coil 110 is connected in series with a later-described capacitor. The power transmission coil 110 is made of wire. Wires include, for example, single wires and litz wires. An example of the material of the power transmission coil 110 is copper. The power transmission coil 110 has a shape surrounding two quadrilaterals. Power transmission coil 110 is an air core. The number of turns of the power transmission coil 110 is preferably 1 or more and 3 or less. Of course, it is not limited to this numerical range. In addition, in FIG. 2, the number of turns of the power transmission coil 110 is one.

Power receiving coil 120 is a coil that generates current by the magnetic field formed by power transmitting coil 110 . Power receiving coil 120 is connected in series with a capacitor, which will be described later. Power receiving coil 120 is made of wire. Wires include, for example, single wires and litz wires. An example of the material of the power receiving coil 120 is copper. In FIG. 2, power receiving coil 120 has a shape close to a square, but may have a helical shape like a spring.

The power transmission circuit 130 is a circuit for oscillating an AC voltage to be applied to the power transmission coil 110 . The power transmission circuit 130 generates alternating current of 6.78 MHz.

The power receiving circuit 140 is a circuit for converting the current flowing through the power receiving coil 120 into a current suitable for the light emitting device 150 . Specifically, the AC voltage of power receiving coil 120 is converted into a DC voltage for driving light emitting device 150 . The power receiving circuit 140 may have other functions such as a rectifying circuit.

The light emitting device 150 is for clearly indicating the position of the knob N1 to the user even in a dark vehicle. Light emitting device 150 is an electronic component driven by power from power receiving coil 120 . The light emitting device 150 constitutes a part of the knob N1 of the air conditioning register. The light emitting device 150 has a semiconductor light emitting element. The light emitting device 150 emits light with a DC voltage. The light emitting device 150 is an electronic device and an electronic component. Note that the knob N1 is an operation unit operated by the user. By changing the position of the knob N1 by the user, the user can adjust the wind direction of the air conditioning register CA1.

The housing 160 is the housing of the air conditioning register CA1. In other words, the device surrounded by the housing 160 is the air conditioning register CA1. The material of the housing 160 is, for example, plastic. Since the housing 160 is the housing of the device, its thickness is sufficiently thin.

3. Transmission coil 3-1. Fixed State of Power Transmission Coil and Housing FIG. 3 is a diagram (Part 1) showing a fixed state of power transmission coil 110 and housing 160 . As shown in FIG. 3, a groove 161 is formed in the outer wall of the housing 160 . Power transmission coil 110 is arranged so as to be accommodated in groove 161 of housing 160 . In this manner, power transmission coil 110 is fixed to housing 160 .

FIG. 4 is a diagram (Part 2) showing a fixed state between power transmission coil 110 and housing 160 . The power transmission coil 110 may be fixed to the housing 160 as shown in FIG. FIG. 5 is a partial cross-sectional view showing a part of the V-V cross section of FIG. As shown in FIG. 4, a claw 162 is formed on the outer wall of the housing 160 . Power transmitting coil 110 is positioned by a plurality of claws 162 and fixed to housing 160 . Claw 162 is a support member for fixing power transmission coil 110 .

Other support members may be used as long as they can position and fix the power transmission coil 110 relative to the housing 160 in this way. Moreover, it is preferable that the housing 160 and the power transmission coil 110 are partially in contact with each other.

Note that the groove 161 of the housing 160 or the support member does not completely cover the power transmission coil 110, and at least a portion of the power transmission coil 110 is in contact with the atmosphere. That is, the power transmission coil 110 is not sealed with a non-conductive material.

3-2. Shape of Power Transmission Coil FIG. 6 is a diagram showing the shape of power transmission coil 110 . In FIG. 6, power transmission coil 110 has one turn. The surface surrounded by power transmission coil 110 is a plane. That is, power transmission coil 110 has a planar shape positioned on one plane. The plane surrounded by the power transmission coil 110 is taken on the xy plane. Then, the z-axis is taken in a direction perpendicular to the plane surrounded by the power transmission coil 110 .

The length of the power transmission coil 110 in the x-axis direction is, for example, 10 mm or more and 400 mm or less. It is good in it being 80 mm or more and 350 mm or less. The length of the power transmission coil 110 in the y-axis direction is, for example, 10 mm or more and 400 mm or less. It is good in it being 50 mm or more and 100 mm or less. The length of the power transmission coil 110 in the z-axis direction is, for example, 0.5 mm or more and 10 mm or less. These numerical ranges are guidelines, and numerical values other than the above may be used.

As shown in FIG. 6 , power transmission coil 110 has first section 111 , second section 112 , and connection portion 113 . The first section 111 is a portion surrounding the housing 160 of the first air-conditioning register. The second compartment 112 is the part surrounding the housing 160 of the second air conditioning register. The connecting portion 113 is a portion that connects the first section 111 and the second section 112 .

The first section 111 has four sides 111a, 111b, 111c, 111d. The four sides 111a, 111b, 111c, and 111d generate magnetic fields near the center of the first section 111, respectively. Since the four sides 111 a , 111 b , 111 c , and 111 d surround the housing 160 in this manner, a relatively strong magnetic field is formed around the housing 160 .

The second section 112 has four sides 112a, 112b, 112c, 112d. The four sides 112a, 112b, 112c, 112d generate magnetic fields near the center of the second section 112, respectively. Since the four sides 112 a , 112 b , 112 c , 112 d surround the housing 160 in this manner, a relatively strong magnetic field is formed around the housing 160 .

Thus, power transmission coil 110 has four sides surrounding housing 160 .

Compared to when the sides 111d and 112d are very short or do not exist, the power transmission coil 110 of this embodiment can form a stronger magnetic field. Further, since power transmission coil 110 has sides 111 d and 112 d, power transmission coil 110 can be easily fixed to housing 160 .

4. Power Receiving Coil FIG. 7 is a perspective view showing the positional relationship between power receiving coil 120 and light emitting device 150 . As shown in FIG. 7, the knob N1 is an operation unit for adjusting the wind direction of the air conditioning register. Knob N1 accommodates power receiving coil 120 , power receiving circuit 140 and light emitting device 150 . The receiving coil 120 is spiral. The voltage and current from power receiving coil 120 are input to power receiving circuit 140 . The power receiving circuit 140 converts AC voltage into DC voltage to drive the light emitting device 150 .

Knob N1 is an operation unit and is arranged inside housing 160 or on the surface of housing 160 . Therefore, power receiving coil 120 is arranged inside housing 160 or on the surface of housing 160 .

Power receiving coil 120 is wound so as to be stacked in the z-axis direction. In other words, instead of winding the coils so that the coils fit within the same plane, the coils are wound so as to be stacked in the z-axis direction perpendicular to the plane surrounded by the coils.

The area of the surface surrounded by power receiving coil 120 is sufficiently smaller than the area of the surface surrounded by power transmitting coil 110 . The ratio of the area of the surface surrounded by power receiving coil 120 to the area of the surface surrounded by power transmitting coil 110 is about 1/200 or more and 1/10 or less. It is only a guideline, and numerical values other than the above may be used.

5. Circuit of Wireless Power Supply System FIG. 8 is a diagram schematically showing a circuit of the wireless power supply system 100 of the present embodiment. As shown in FIG. 8, power transmission coil 110 forms an LC series circuit together with capacitor C1. Power receiving coil 120 forms an LC series circuit together with capacitor C2. As described above, the circuit is designed such that the resonant frequency of the LC series circuit on the power transmitting coil 110 side and the resonant frequency of the LC series circuit on the power receiving coil 120 side are equal.

The power transmission output in the wireless power supply system 100 is 10 W or less. For example, 5W. A voltage for driving the light emitting device 150 is, for example, 5V. Of course, numerical values other than the above may be used. The current flowing through the light emitting device 150 is 1 mA or less. Of course, numerical values other than the above may be used.

Note that in FIG. 8 , the capacitor C<b>1 is depicted as being outside the power transmission circuit 130 . FIG. 8 is conceptual and capacitor C1 may be in transmission circuit 130 . Similarly, capacitor C2 may be in receiving circuit 140 .

6. Effect of this Embodiment Even in a place such as the knob N1 of the air-conditioning register CA1 where wiring is difficult to connect, the electronic component can be operated by wireless power supply.

Due to the design of the vehicle, the space for arranging the power transmission coil 110 and the like inside the vehicle is limited. In this embodiment, the power transmission coil 110 is fixed to the outer wall of the housing 160 of the air conditioning register CA1. Furthermore, since the shape of the power transmission coil 110 is adapted to the outer shape of the housing 160, it leads to space saving, which is advantageous in terms of design.

In addition, vibrations generally occur in vehicles. Therefore, there is a possibility that the position of the power transmission coil 110 that should be fixed may be displaced. In the wireless power supply system 100 of the present embodiment, since the power transmission coil 110 is sufficiently fixed to the housing 160, there is almost no possibility that the position of the power transmission coil 110 will shift even if vibrations occur repeatedly in the vehicle.

Power receiving coil 120 is preferably positioned within a plane surrounded by power transmitting coil 110, but may be shifted in the z-axis direction due to mounting of on-vehicle components. Since the wireless power supply system 100 employs a magnetic field coupling system, even if the displacement in the z-axis direction between the power transmitting coil 110 and the power receiving coil 120 is, for example, several tens of centimeters, power can be supplied to the light emitting device 150 without problems. can be done.

7. Modification 7-1. Attachment of Power Transmission Coil FIG. 9 is a diagram for explaining attachment of the power transmission coil 110 and the housing 160 in the modification of the first embodiment. As shown in FIG. 9 , the power transmission coil 110 may be tilted and attached to the substantially rectangular parallelepiped housing 160 .

7-2. Supporting Member The supporting member provided on housing 160 may have other shapes or configurations. For example, clips, spacers, etc. can be employed.

7-3. Lamination Direction of Power Transmitting Coil When the power transmitting coil 110 is wound with two or more turns, it is stacked in the z-axis direction in the same manner as the power receiving coil 120 in FIG. 7 . In other words, the coil is wound so that it is laminated in a direction that intersects the surface surrounded by the coil.

7-4. Wireless Power Supply System The wireless power supply system 100 of the present embodiment is a magnetic field coupling system. However, the technology of the first embodiment can also be applied to an electromagnetic induction wireless power supply system.

7-5. Housing The housing 160 of this embodiment is the housing of the air conditioning register CA1. However, housing 160 may be a housing for other vehicle components. Further, it may be an electrical appliance other than an in-vehicle component. The material of housing 160 may be glass, resin, ceramics, or other non-conductive materials.

7-6. Electronic Component The wireless power feeding system 100 of the present embodiment has a light emitting device 150 . Wireless power supply system 100 may have other electronic devices or electronic components instead of light emitting device 150 .

7-7. Combination The above modifications may be freely combined.

(Second embodiment)
A second embodiment will be described. In the second embodiment, the shape of the power transmission coil is different from that in the first embodiment. Therefore, the power transmission coil will be described.

1. Three-Dimensional Shape of Power Transmission Coil FIG. 10 is a front view showing the shape of the power transmission coil 210 of the second embodiment. As shown in FIG. 10 , power transmission coil 210 has first section 211 , second section 212 , and connection portion 113 . The first section 211 has four sides 111a, 111b, 211c, 111d. The second section 212 has four sides 112a, 112b, 212c, 112d.

FIG. 11 is a view of power transmission coil 210 viewed from the direction of arrow J1 in FIG. As shown in FIG. 11 , side 211 c and side 212 c of power transmitting coil 210 protrude toward power receiving coil 120 . Therefore, side 211 c and side 212 c are curved toward receiving coil 120 .

2. Effects of this Embodiment As shown in FIG. 11, the z-axis is set. In this case, the distance K1 (z-axis direction) between the projecting portion of side 211c and power receiving coil 120 is smaller than the distance K2 (z-axis direction) between side 111a and power receiving coil 120 . As shown in FIG. 11, since the distance K1 is sufficiently smaller than the distance K2, the side 211c can generate a stronger magnetic field at the position of the receiving coil 120. FIG.

3. Modification 3-1. Number of Protruding Sides In FIG. 11 , only one side 211 c of the four sides of the first section 211 protrudes toward the receiving coil 120 . However, the number of sides protruding toward receiving coil 120 may be greater. The number of sides protruding toward power receiving coil 120 is 1 or more and 4 or less. That is, at least one of the four sides of power transmitting coil 110 protrudes toward power receiving coil 120 .

3-2. Combination The second embodiment and its variations may be freely combined with the first embodiment and its variations.

(Third Embodiment)
FIG. 12 is a diagram showing the configuration of the wireless power feeding system of the third embodiment. As shown in FIG. 12, the wireless power supply system of the third embodiment includes two power receiving coils 1A and 1B, one power transmitting coil 2, an AC power supply 3 connected to the power transmitting coil 2, a circuit 4, and a power receiving coil. It has circuits 5A and 5B connected respectively to 1A and 1B.

The wireless power feeding system of the third embodiment is a system that transmits electric power from one power transmitting coil 2 to two power receiving coils 1A and 1B in a non-contact manner using a magnetic resonance method. The output of transmitted power is, for example, 10 W or less.

The AC power supply 3 is a power supply that supplies AC current to the power transmission coil 2 . Its frequency is, for example, 500 kHz to 15 MHz. A circuit 4 is a circuit for setting the resonance frequency on the power transmission side, and is set to a predetermined frequency by the capacitance of the capacitor and the inductance of the inductor. The circuits 5A and 5B are circuits for matching the resonance frequency of the power receiving side with the resonance frequency of the power transmission side, and are set to a predetermined frequency by the capacitance of the capacitor and the inductance of the inductor. A load (not shown) is connected to the circuits 5A and 5B. If the load is a DC-driven device, the received power is converted to DC and supplied to the load. A load is, for example, a light-emitting element.

The receiving coils 1A, 1B and the transmitting coil 2 are made of wire. Any conductive material can be used as the wire material, and for example, a Litz wire or a single copper wire is used. Further, the pattern may be printed on a printed circuit board such as an FPC instead of the wire material.

Next, the shape and arrangement of the power receiving coils 1A and 1B and the power transmitting coil 2 will be described with reference to FIG. FIG. 13 shows the shape of one coil of the power transmission coil 2 as seen from a direction perpendicular to the plane formed by one coil of the power transmission coil 2 . For convenience of explanation, a coordinate system is defined as shown in FIG.

First, the receiving coils 1A and 1B will be described. As shown in FIG. 13, the receiving coils 1A and 1B are arranged with a predetermined interval in the x-axis direction. The interval is arbitrary as long as the interference between the power receiving coil 1A and the power receiving coil 1B is sufficiently reduced. The power receiving coils 1A and 1B are arranged so that the axial direction of the power receiving coils 1A and 1B coincides with the z-axis direction, and the plane formed by the power receiving coils 1A and 1B and the plane formed by the power transmitting coil 2 are on the same plane.

The power receiving coils 1A and 1B are circular coils formed by winding wires in a circular shape. The winding direction is the z-axis direction. Cylindrical ferrite cores 10A and 10B are inserted in the centers of the receiving coils 1A and 1B, respectively. The power receiving coils 1A and 1B have a cross-sectional area of 12 mm ² , a number of turns of 4.5, and an axial length (z-axis length) of 6.5 mm. The ferrite cores 10A and 10B have a diameter of 8 mm and a length of 7 mm.

Note that the cross-sectional areas and the number of turns of the power receiving coils 1A and 1B are not limited to the values shown in the third embodiment, and are set according to the received power, power receiving efficiency, and the like. For example, when the transmitted power is 10 W or less, the widths (coil diameters) in the x-axis and y-axis directions (coil diameters) of the receiving coils 1A and 1B are 3 to 200 mm, and the lengths in the axial direction (z-axis direction) of the coils are is preferably 1 to 20 mm. The power receiving efficiency can be improved, and the power receiving power difference can be further reduced.

Further, the shape of the power receiving coils 1A and 1B is not limited to circular, and may be square, rectangular, or the like. Also, the power receiving coil 1A and the power receiving coil 1B may have different shapes. However, from the viewpoint of facilitating control of the received power difference between the power receiving coil 1A and the power receiving coil 1B, it is preferable that the power receiving coils 1A and 1B have the same shape.

Further, the receiving coils 1A and 1B do not necessarily require a core material, and may be an air-core coil. However, when the cross-sectional area of the power receiving coils 1A and 1B is set to 20 mm ² or less, it is preferable to use a ferrite core from the viewpoint of improving the power receiving efficiency.

In addition, the plane formed by the power receiving coils 1A and 1B does not necessarily have to be the same plane as the plane formed by the power transmitting coil 2. As long as the power from the power transmitting coil 2 can be received, the plane formed by the power transmitting coil 2 is different from the plane formed by the power transmitting coil 2. They may be parallel different planes or they may be angled planes. Further, the plane formed by the power receiving coil 1A and the plane formed by the power receiving coil 1B may be parallel different planes, or may form an angle.

Moreover, the winding direction of the power receiving coils 1A and 1B may be left-handed or right-handed, and the winding direction may be changed between the power receiving coils 1A and 1B.

Next, the power transmission coil 2 will be described. The power transmission coil 2 is a wire material wound a plurality of times in the z-axis direction, and as shown in FIG. The connecting part 21 and , and have a gourd-shaped or spectacle-shaped shape as a whole. The action portions 20A and 20B and the connection portion 21 are clearly shown by enclosing them with dotted lines in FIG. The number of turns of the power transmission coil 2 is appropriately set according to the transmitted power, transmission efficiency, etc., and is, for example, 2 to 3 turns. Moreover, the winding direction may be left-handed or right-handed.

The acting portion 20A is a portion that mainly contributes to power transmission to the power receiving coil 1A, and the acting portion 20B is a portion that mainly contributes to power transmission to the power receiving coil 1B. The acting portions 20A and 20B are wire rod portions having a rectangular cross-sectional shape, and are spaced apart in the x-axis direction. Further, the surface formed by the action portion 20A and the surface formed by the action portion 20B are the same plane. Also, the action portions 20A and 20B are arranged so that their sides are aligned. In addition, the receiving coil 1A is arranged at the center of the acting portion 20A, and the receiving coil 1B is arranged at the center of the acting portion 20B. The working portions 20A and 20B have a width of 140 mm in the x-axis direction and a width of 90 mm in the y-axis direction.

In this manner, the acting portions 20A and 20B are arranged so as to surround the receiving coils 1A and 1B on all four sides. In other words, the sides of the acting portions 20A and 20B are positioned equidistantly in the +x direction, -x direction, +y direction, and -y direction with respect to the centers of the receiving coils 1A and 1B. Therefore, the distribution of the magnetic field strength generated from each side of the action portions 20A and 20B becomes uniform, and the difference in the power received by the power receiving coils 1A and 1B also becomes small.

In order to further reduce the difference in power received by the power receiving coils 1A and 1B, the difference between the longest distance and the shortest distance from the center of the power receiving coils 1A and 1B to the acting portions 20A and 20B is (the diameter of the circumscribed circles of the acting portions 20A and 20B).

In addition, the cross-sectional area of the power receiving coils 1A and 1B is set to 1/2 or less of the cross-sectional area of the action portions 20A and 20B. By setting the cross-sectional areas of the receiving coils 1A and 1B or the cross-sectional areas of the acting portions 20A and 20B in this way, it is possible to suppress the difference in power received from the acting portions 20A and 20B. More preferably, it is 1/50 or less of the cross-sectional area of the acting portions 20A and 20B.

In the third embodiment, the planar pattern of the acting portions 20A and 20B is rectangular, but any shape may be used as long as it surrounds the power receiving coils 1A and 1B. It may have a different shape from the planar pattern of the portion 20B. For example, the planar patterns of the action portions 20A and 20B are square, rectangle, rhombus, circle, semicircle, ellipse, polygon, and the like. FIG. 14 shows an example in which the action portion 20A is circular and the action portion 20B is rectangular. The cross-sectional area of the coil may be changed between the acting portion 20A and the acting portion 20B. FIG. 15 shows an example in which the cross-sectional area of the action portion 20A is made larger than the cross-sectional area of the action portion 20B. When the power transmission coil 2 is mounted by being wound around a housing, it may have a shape that matches the shape of the housing.

In the third embodiment, the surface formed by the action portion 20A and the surface formed by the action portion 20B are the same plane, but they may be different parallel planes as long as power can be transmitted to the power receiving coils 1A and 1B. , may form an angle.

In addition, the power receiving coils 1A and 1B are not necessarily positioned at the center of the action portions 20A and 20B, but preferably near the center from the viewpoint of suppressing the difference in power reception.

The connection portion 21 is a portion that connects the action portion 20A and the action portion 20B, and is two straight wire rods extending in the x-axis direction. On the side where the action portion 20A and the action portion 20B face each other, one of the corner portions of the action portion 20A and the opposite corner portion of the action portion 20B are connected by a connecting portion 21 . Here, the connecting portion is arbitrary as long as the wire rod is not branched and the acting portions 20A, 20B and the connecting portion 21 are connected in a single stroke as a whole. One of the two straight lines of the connecting portion 21 forms one straight line continuous with one side of the action portions 20A and 20B.

The position of the connecting portion 21 is not limited to the position shown in the third embodiment, and may be connected to the action portions 20A and 20B at any position. For example, as shown in FIG. 16, the action portions 20A and 20B may be connected at the central portion of the opposing sides. However, the position shown in the third embodiment requires fewer positions to bend the wire, and a wider spatial region between the acting portion 20A and the acting portion 20B can be secured without division. 2 is easier to implement. Furthermore, since the corners of the acting portions 20A and 20B are positioned farther than the power receiving coils 1A and 1B, the power receiving efficiency is improved.

In addition, in the third embodiment, the connecting portion 21 has a shape in which two wires are arranged in a straight line parallel to each other. Also, the two wires may be in contact with each other or may be twisted together. Also, the length of the connecting portion 21 may be arbitrary.

The shape and size of the power transmission coil 2 as a whole are not particularly limited. The length (length in the z-axis direction) is preferably 1 to 100 mm. The power receiving efficiency can be improved, and the power receiving power difference can be further reduced. Further, in this case, the shape and size of the acting portions 20A and 20B and the connecting portion 21 are arbitrary as long as they are within the above size range as a whole.

In addition, in the third embodiment, the two wires connected to the circuit 4 are drawn out from the acting portion 20A, but the drawing position may be arbitrary, and they may be drawn out from the connecting portion 21. FIG.

As described above, in the wireless power supply system of the third embodiment, the power receiving coils 1A and 1B are arranged so that the power transmitting coils surround the respective power receiving coils 1A and 1B. can be suppressed.

Although the wireless power supply system of the third embodiment transmits power to two power receiving coils, the third embodiment can also be applied to a system that powers power to three or more power receiving coils. . FIG. 17 shows an example in which three receiving coils are used. As shown in FIG. 17, the power transmission coil 30 has acting portions 30A, 30B, and 30C, the acting portions 30A and 30B are connected by a connecting portion 31A, and the acting portions 30B and 30C are connected by a connecting portion 32B. It is The receiving coils 1A, 1B, 1C are arranged at the centers of the action portions 30A, 30B, 30C. As a result, the respective power receiving coils 1A, 1B, 1C are surrounded on all sides by the acting portions 30A, 30B, 30C.

Further, the wireless power supply system of the third embodiment is suitable for suppressing the difference in received power between two receiving coils, but can also be used to adjust the difference in received power to a desired value.

(Appendix)
A wireless power supply system according to a first aspect includes an air-core power transmission coil, a power reception coil, a device surrounded by a housing, and an electronic component driven by power from the power reception coil. The housing has grooves or support members in the outer wall of the housing. The power transmission coil is fixed to the groove of the housing or the support member. The receiving coil is arranged inside the housing or on the surface of the housing.

In the wireless power supply system according to the second aspect, the power transmission coil has four sides surrounding the housing. At least one side of the four sides of the power transmitting coil protrudes toward the power receiving coil.

In the wireless power supply system according to the third aspect, the electronic component is a light emitting device. A device surrounded by a housing has an operation unit for operating the device surrounded by the housing. The operation unit has a power receiving coil and a light emitting device.

In the wireless power supply system according to the fourth aspect, the power transmission coil is a wire.

In the wireless power supply system according to the fifth aspect, the current flowing through the electronic component is 1 mA or less.

The wireless power supply system in the sixth aspect is of magnetic coupling type.

In the wireless power supply system according to the seventh aspect, the housing is a housing of an air conditioning register.

In the wireless power supply system according to the eighth aspect, the groove of the housing or the support member does not completely cover the power transmission coil, and at least part of the power transmission coil is exposed to the atmosphere.

DESCRIPTION OF SYMBOLS 100... Wireless electric power feeding system 110... Power transmission coil 120... Power reception coil 130... Power transmission circuit 140... Power reception circuit 150... Light-emitting device 160... Housing

Claims (8)

an air-core transmission coil;
a receiving coil;
a device enclosed in a housing;
an electronic component driven by power from the power receiving coil;
has
Having a support member on the outer wall of the housing,
The power transmission coil is fixed to the support member of the housing,
The receiving coil is arranged inside the housing or on the surface of the housing,
The support member does not completely cover the power transmission coil, and at least a portion of the power transmission coil is in contact with the atmosphere.
A wireless power supply system characterized by: an air-core transmission coil;
a receiving coil;
a device enclosed in a housing;
an electronic component driven by power from the power receiving coil;
has
having grooves or support members on the outer wall of the housing,
The power transmission coil is fixed to the groove of the housing or the support member,
The receiving coil is arranged inside the housing or on the surface of the housing,
The power transmission coil has four sides surrounding the housing,
A wireless power feeding system, wherein only a first side of four sides of the power transmitting coil protrudes toward the power receiving coil. In the wireless power supply system according to claim 2,
The distance between the projecting portion of the first side of the four sides of the power transmitting coil and the power receiving coil is a second distance not adjacent to the first side of the four sides of the power transmitting coil. A wireless power feeding system, wherein the distance is smaller than a distance between a side and the power receiving coil. an air-core transmission coil;
a receiving coil;
a device enclosed in a housing;
an electronic component driven by power from the power receiving coil;
has
having grooves or support members on the outer wall of the housing,
The power transmission coil is fixed to the groove of the housing or the support member,
The receiving coil is arranged inside the housing or on the surface of the housing,
The housing has a rectangular parallelepiped shape,
The wireless power supply system, wherein the power transmission coil has four sides surrounding a housing and is inclined with respect to the rectangular parallelepiped housing. an air-core transmission coil;
a receiving coil;
a device enclosed in a housing;
an electronic component driven by power from the power receiving coil;
has
having a groove or a support member on an outer wall of the housing that surrounds the central axis of the power receiving coil ;
The housing is a housing of an air conditioning register,
The power transmission coil is fixed to the groove of the housing or the support member and surrounds the housing,
The wireless power supply system, wherein the receiving coil is arranged inside the housing or on the surface of the housing. In the wireless power supply system according to claim 1 or claim 5,
The power transmission coil has four sides surrounding the housing,
A wireless power feeding system, wherein at least one side of four sides of the power transmitting coil protrudes toward the power receiving coil. In the wireless power supply system according to any one of claims 1 to 5,
the electronic component is a light-emitting device,
The device surrounded by the housing has an operation unit for operating the device surrounded by the housing,
The wireless power supply system, wherein the operation unit includes the power receiving coil and the light emitting device. In the wireless power supply system according to any one of claims 2 to 7,
The wireless power supply system, wherein the groove of the housing or the support member does not completely cover the power transmission coil, and at least part of the power transmission coil is in contact with the atmosphere.

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