JP2016066812A - Power reception coil, power reception device and non-contact power transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable increase of a Q-value of a power reception coil used for a power reception device and suppression of degradation of the Q-value of the power reception coil when the power reception coil is put in a housing.SOLUTION: A power reception coil has a coil portion which is obtained by winding a wire around a core formed of a magnetic material and electromagnetically coupled with an external coil through electromagnetic resonance, a resin part having a core and a coil portion, and a side surface being formed in the resin portion so as to be away from the side surface of the coil portion by a predetermined distance, and a non-magnetic body disposed on the side surface of the resin portion so as to be parallel to the center axis of the core thereof. The core has a shaft core portion, a first flange portion provided to an end portion of the shaft core portion, and a second flange portion provided to an end portion at the opposite side to the first flange portion. The outer diameter of the winding of the wire around the shaft core portion of the core of the coil portion is smaller than the outer diameter of the winding of a power transmission coil.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a power receiving coil in which power is transmitted from an electromagnetically coupled power transmitting coil, a power receiving device including the power receiving coil, and a non-contact power transmission system using the power receiving device.

  In recent years, a non-contact power transmission system that performs non-contact power transmission using a power transmission coil and a power reception coil has been proposed (see, for example, Patent Document 1).

  When the power transmission coil of the non-contact power transmission system has a spiral shape and the power reception coil also sends power in a spiral shape, the power reception coil built in the power reception device is used in the metal inside the device (for example, in a case or circuit) ) Greatly deteriorates the Q value. The Q value is an index indicating the relationship between energy retention and loss, or the strength of resonance of the resonance circuit.

  In order to prevent the influence of this metal, a magnetic sheet is pasted on the backs of the spiral-shaped power transmission coil and power reception coil. This magnetic sheet needs a certain thickness in order to prevent the influence of the metal inside the apparatus. In order to completely prevent the influence of the metal inside the apparatus, a magnetic sheet having a size much larger than that of the coil is required. This magnetic sheet is generally made of ferrite (sintered body). Therefore, to make a magnetic sheet thin, a ferrite sheet is thinly formed, laminated with thin resin sheets on the upper and lower sides, and then cut into fine pieces, which is very expensive. Since this ferrite magnetic sheet is matched to the coil as described above, it has a large area and a large variation in thickness and the like, and the variation in the constant of the coil resulting therefrom has caused a large deterioration in the Q value.

上記のとおり、式（１）のコイル間効率（η_rf）は、式（２）のＳ＝ｋ＊√（Ｑ_１＊Ｑ_２）の値に応じて決まる。 When power is transmitted in a non-contact manner, the power transmission efficiency (also referred to as “coil efficiency”) (η _rf ) is the coupling coefficient k, which is the degree of coupling between the power transmission coil and the power reception coil, and Q values of the power transmission coil (Q _1), theoretically can be uniquely determined from the Q-value of the receiving coil (Q _2). Formulas (1) to (3) are used to calculate the inter-coil efficiency (η _rf ).

As described above, the inter-coil efficiency (η _rf ) in Expression (1) is determined according to the value of S = k * √ (Q ₁ * Q ₂ ) in Expression (2).

When the coupling coefficient k between the power transmission coil and the power reception coil is large, that is, in the case of electromagnetic induction, the sizes of the power transmission coil and the power reception coil, such as the winding diameter, are substantially the same, and the Q values (Q ₁ , Q ₂ ) Is small, power can be transmitted. However, since the inter-coil efficiency (η _rf ) in the case of electromagnetic induction depends on the coupling coefficient k, the positional accuracy between the power transmitting coil and the power receiving coil is very important, and positional deviation is not allowed. Therefore, when charging in the case of electromagnetic induction, the power transmission coil and the power reception coil have a one-to-one correspondence. Also, if an electronic device with a high metal usage rate, such as a mobile phone terminal or a digital camera, is placed on a spiral shaped power transmission coil, the Q value of the power receiving coil built into the electronic device will greatly deteriorate. It is necessary to compensate for the deterioration with the coupling coefficient k.

  On the other hand, as an electromagnetic resonance method, the coupling coefficient k between the power transmission coil and the power reception coil is reduced, the Q value as a resonator is increased to transmit power to a plurality of electronic devices, and the power reception coil A method for arranging the symbols freely has been proposed.

Japanese Patent No. 4413236 (Japanese Patent Laid-Open No. 2008-206231)

However, when a power receiving coil stored in an electronic device having a high metal usage rate, such as a mobile phone terminal or a digital camera, is placed on a planar spiral power transmission coil, the Q value (Q ₁ ) of the power transmission coil and The Q value (Q ₂ ) of the power receiving coil deteriorates, and power cannot be transmitted. Therefore, the application is limited to those not affected by the metal of the electronic device.

  In addition, the power receiving coil mounted on the electronic device is smaller than the size of the power transmission coil, the Q value is not as large as about 50, and deteriorates in order to increase the degree of freedom of arrangement with respect to the power transmission coil. It was difficult to realize a contactless power transmission system.

  The present disclosure has been made in consideration of the above situation, and increases the Q value of the power receiving coil used in the power receiving apparatus, and reduces deterioration of the Q value of the power receiving coil when the power receiving coil is placed inside the housing. Is.

The power receiving coil according to the present disclosure includes a coil portion in which a wire is wound around a core made of a magnetic material, the coil portion being electromagnetically coupled to the power transmission coil by electromagnetic resonance, and power being transmitted, and a certain distance from a side surface of the coil portion. And a non-magnetic material disposed apart from each other.
As an example, the thickness of the nonmagnetic material is 0.3 mm or more. Moreover, the resin part which incorporates the core which has the said magnetic body, and a coil part is provided, and the nonmagnetic body is arrange | positioned at the side surface of the resin part. Moreover, the shape of the core is an H shape having an axial center portion and flange portions at both ends of the axial center portion.

  Moreover, the power receiving apparatus of this indication is provided with the said power receiving coil and the power receiving part which receives an alternating current signal from the power transmission apparatus which has the said power transmission coil via the coil part.

The non-contact power transmission system of the present disclosure includes a power transmission device that generates an AC signal and the power reception device that receives the AC signal generated by the power transmission device.
The power transmission device includes a power transmission coil unit in which a wire is wound in a planar shape, and a power transmission unit that supplies an AC signal to the power transmission coil unit.

  According to the configuration of the present disclosure, the Q value can be increased by forming a coil portion by winding a wire around a core made of a magnetic material. Further, by disposing the non-magnetic material at a position away from the side surface of the coil portion by a certain distance, deterioration of the Q value when the coil portion is placed inside a metal-rich housing can be suppressed.

  According to the present disclosure, it is possible to increase the Q value of the power receiving coil used in the power receiving device, and to reduce the deterioration of the Q value of the power receiving coil when the power receiving coil is placed inside the housing.

It is an appearance perspective view of a receiving coil concerning an example embodiment of this indication. It is a front view of the receiving coil shown in FIG. (A)-(d) is explanatory drawing which shows the manufacturing process of the receiving coil shown in FIG. It is explanatory drawing which shows the example of a combination of the conventional power transmission coil and power receiving coil. It is explanatory drawing of the state which has arrange | positioned the portable terminal telephone carrying the conventional receiving coil on the power transmission coil. It is a graph which shows Q value of the primary side coil when the portable terminal telephone carrying the conventional receiving coil is moved on a power transmission coil. It is explanatory drawing which shows the combination of the receiving coil and power transmission coil which concern on the example embodiment of this indication. It is a graph which shows an example of the characteristic of S value-coil efficiency in the combination of the receiving coil and power transmission coil of FIG. It is a graph which shows an example of the characteristic of the distance-coil efficiency between the primary side coils in the combination of the receiving coil and power transmission coil of FIG. It is explanatory drawing which shows a mode that a metal is brought close to the receiving coil side surface which concerns on one example of embodiment of this indication. It is a graph which shows an example of the characteristic of distance -Q value of a metal and a coil side surface. It is a schematic structure figure of a non-contact electric power transmission system provided with a receiving coil and a power transmission coil concerning one example of an embodiment of this indication, respectively.

Hereinafter, exemplary embodiments for carrying out the present disclosure will be described with reference to the accompanying drawings. The description will be given in the following order. In addition, in each figure, the same code | symbol is attached | subjected to the common component and the overlapping description is abbreviate | omitted.
1. Structure of power receiving coil in one embodiment (example in which a conducting wire is wound around an H-shaped core)
2. 2. Combination of conventional power transmission coil and power reception coil 3. Combination of power transmission coil and power reception coil in one embodiment Other

<1. Structure of Power Receiving Coil of One Embodiment>
First, a structure of a power receiving coil according to an embodiment of the present disclosure (hereinafter also referred to as “this example”) will be described with reference to FIGS. 1 and 2.
FIG. 1 is an external perspective view of a power receiving coil according to an embodiment of the present disclosure. FIG. 2 is a front view of the power receiving coil shown in FIG. This power receiving coil is a coil used on the power receiving side of a non-contact power transmission system that transmits power by electromagnetically coupling two coils. Electromagnetic coupling is also called “electromagnetic resonance coupling” or “electromagnetic resonance”, and includes electric field coupling and magnetic field coupling. In either case, resonance is used, and power is transmitted only to the resonating device by coupling of an electric field or a magnetic field. In the following example, electromagnetic coupling will be described.

  The power receiving coil 1 of this example includes a Litz wire (in this example, a wire diameter of φ0...) In which a plurality of thin soft coppers are wound on a side-shaped H-shaped core (magnetic core) 2 made of a magnetic material (for example, ferrite). As an example, 15 wire rods 5 (in this example, wire diameter φ1.0 mm) are wound around a predetermined number of turns. Then, a nonmagnetic material 6 made of, for example, 0.5 mm thick aluminum (Al) is placed on the resin portion 3 confined together with the core 2 at a predetermined distance from the shaft core portion 2 a of the core 2. It is affixed in parallel with the axis (Z axis) of the part 2a. In the state where the nonmagnetic material 6 was attached, the inductance (L value) of the power receiving coil 1 was 7.61 μH and the Q value was 180.

Next, the manufacturing process of the power receiving coil 1 will be described with reference to FIGS.
First, an H-type core 2 is prepared in which flange portions 2b and 2c made of ferrite are attached to both ends of an axis portion 2a made of ferrite (FIG. 3A).
Subsequently, the entire H-shaped core 2 is covered with resin, and the resin portion 3 is formed by a technique such as molding (FIG. 3B). At this time, the resin part 3 is molded so that the side surface 3a is at a predetermined distance from the central axis (Z-axis) of the axial part 2a of the core 2. In this example, a gap is formed between the side surface 3a of the resin portion 3 and the portion corresponding to the shaft core portion 2a of the core 2 in order to reduce the amount of resin used in the resin portion 3 and to reduce the weight of the power receiving coil 1. Part 4 is provided.
And the wire 5 is wound around the part corresponding to the axial part 2a of the core 2 of the molded resin part 3 (an example of a coil part) (FIG.3 (c)). The L value is adjusted by the number of turns.
Finally, a plate-like nonmagnetic material 6 made of, for example, 0.5 mm thick aluminum is attached to the side surface 3 a of the resin portion 3 to complete the power receiving coil 1.

  In this example, aluminum is attached as the nonmagnetic material, but a nonmagnetic material such as copper may be used. Further, although one plate-like non-magnetic material is attached, it may be attached to two sides and three sides so as to surround the core 2. Further, although a rectangular plate-like nonmagnetic material is used, a nonmagnetic material may be provided around the shaft portion 2a of the core 2 so as to be along the cylinder.

  In this example, the shape of the core is the H type, but a similar result can be obtained even with the T type or the I type having a somewhat low coupling coefficient. The T-type is a shape in which only one of the flange portions 2b and 2c is attached to the core 2 in FIG. Further, the I type refers to a shape in which neither of the flange portions 2b and 2c is attached, or the area thereof is smaller than that of the H type.

  In this example, the molded resin part 3 secures the distance between the shaft core part 2a of the core 2 and the non-magnetic material 6 (non-magnetic material such as metal). You may create by sticking a mold. If it demonstrates in the example of FIG.3 (b), the molded mold will be applied to the left side part from the space | gap part 4, instead of making the resin part 3 whole integral structure.

  Moreover, in this example, although the cross-sectional shape of the axial part 2a of the core 2 is made into the rectangle, circular may be sufficient. Furthermore, although the same magnetic material is used for the shaft core portion 2a and the flange portions 2b and 2c of the core 2, an amorphous alloy having a high magnetic permeability may be applied to the flange portions 2b and 2c. As an amorphous alloy, for example, there is a cobalt (Co) based amorphous alloy such as an Mg—Zn alloy. When an amorphous alloy is used, since the strength is increased, the flange portion is reduced in thickness, and as a result, the entire core 2 can be reduced in size. Further, the entire core 2 may be formed of an amorphous alloy.

<2. Combination of conventional power transmission coil and power reception coil>
Here, with reference to FIGS. 4-6, the combination of the conventional power transmission coil and power receiving coil is demonstrated.
FIG. 4 is an explanatory view showing a combination example of a conventional power transmission coil and power reception coil. FIG. 5 is an explanatory diagram of a state in which a mobile terminal phone equipped with a conventional power receiving coil is arranged on the power transmitting coil. FIG. 6 is a graph showing the Q value of the primary coil when a portable terminal phone equipped with a conventional power receiving coil is moved on the power transmitting coil.

  In the example of FIG. 4, a planar spiral power transmission coil 11 is used on the power transmission side, and the size of the power transmission coil 11 is 190 × 150 mm as an example. The power transmission coil 11 is an alpha winding that winds the wire material at the beginning and end of winding around the outer periphery of the coil. The space factor can be improved by winding with alpha. On the other hand, a planar spiral power receiving coil 15 is used on the power receiving side, and the size of the power receiving coil 15 is 40 × 30 mm as an example. Further, the magnetic sheet 12 (190 × 150 mm) and the magnetic sheet 16 (40 × 30 mm) of ferrite of the same size as the respective coils are attached to the back surfaces (opposite surfaces of the pair of coils) of the power transmission coil 11 and the power reception coil 15. It has been. At this time, the Q value of the power transmission coil 11 was 230.5, the Q value of the power reception coil 15 was 59.5, and the coupling coefficient k was 0.096.

  As shown in FIG. 5, the power reception coil 15 was actually incorporated into the mobile phone terminal 21, and the mobile phone terminal 21 was moved on the power transmission coil 11 in the X direction and the Y direction for measurement. One corner of the rectangular coil shape is the origin. When the mobile phone terminal 21 is placed at substantially the center of the power transmission coil 11 (95 mm in the X direction and 75 mm in the Y direction), the Q value of the power transmission coil 11 changes from 230.5 to 58 (see FIG. 6). The Q value also deteriorated from 59.5 to 46.4. Further, the efficiency between the coils of 84% was 54%, and the value of the coupling coefficient k deteriorated to 0.068, which was a value that could hardly be used practically.

<3. Combination of power transmission coil and power reception coil in one embodiment>
Next, a combination of the power transmission coil and the power reception coil according to the present disclosure will be described with reference to FIGS.
FIG. 7 is an explanatory diagram illustrating a combination of a power reception coil and a power transmission coil according to an embodiment of the present disclosure. FIG. 8 is a graph showing an example of S value-coil efficiency characteristics in the combination of the power receiving coil and the power transmitting coil shown in FIG. FIG. 9 is a graph showing an example of the distance-coil efficiency characteristic with respect to the primary coil in the combination of the power receiving coil and the power transmitting coil shown in FIG.

  The receiving coil 1A used for the measurement shown in FIG. 7 has the same structure as the receiving coil 1 of FIG. 1 except that the nonmagnetic material 6 is not provided. Actually, the power receiving coil 1 </ b> A was incorporated in the mobile phone terminal 21, and the position of the mobile phone terminal 21 relative to the power transmission coil 11 was moved for measurement. The power receiving coil 1 </ b> A is disposed so that the central axis of the shaft core portion 2 a of the core 2 is parallel to the central axis (Z axis) of the planar power transmitting coil 11.

  At this time, the Q value (Q1) of the power transmission coil 11 deteriorates similarly to the conventional example of FIG. 4, but as shown in FIG. 8, even if the power reception coil 1A is incorporated in the mobile phone terminal 21, the Q value ( The theoretical value of Q2) is 180, and it can be seen that there is almost no deterioration. When the power receiving coil 1A is actually built in the mobile phone terminal 21, the coupling coefficient k is 0.066, which is smaller than that of the conventional power receiving coil 15 (FIG. 4) that is a spiral coil. However, the Q value of the receiving coil 1A is not very high compared to the conventional one, and the inter-coil efficiency is 78%. As shown in FIG. 9, the distance between the power receiving coil 1A and the power transmitting coil 11 was measured in a plurality of arrangements while changing the positional relationship on both XY planes, but no significant deterioration in inter-coil efficiency was observed. . Therefore, from the viewpoint of inter-coil efficiency, it can be said that even if it is incorporated in a set device, the degree of freedom of arrangement with respect to the power transmission coil is high and a very high level can be realized.

(Distance between receiving coil and metal plate)
Next, the distance between the power receiving coil and the metal plate according to an embodiment of the present disclosure will be described.
FIG. 10 shows a state in which the metal plate 26 is brought close to the side surface of the power receiving coil 1 </ b> A composed of the resin portion 3 </ b> A incorporating the core 2. FIG. 11 is a graph showing the characteristic of the Q value with respect to the distance between the power receiving coil 1 </ b> A (coil side surface) and the metal plate 26. In this example, measurement was performed using, for example, 0.5 mm thick aluminum (Al) and stainless steel (SUS) as the metal plate.

  In FIG. 11, the Q value of the power receiving coil 1 </ b> A tends to deteriorate when the metal plate 26 is present nearby, and the Q value deteriorates as the area of the metal plate increases. In terms of metal materials, aluminum and stainless steel have less deterioration in Q value in aluminum. This is presumably because non-magnetic material such as aluminum does not accumulate magnetic field lines, so eddy currents hardly flow and resistance to high-frequency signals increases. In the case of a non-magnetic material such as aluminum, it can be seen that the influence is reduced if it is separated from the coil wound around the core by about 10 mm.

  In the example of FIG. 11, the measurement was performed using a non-magnetic material having a plate thickness of 0.5 mm, but the same result was obtained even in the case of a non-magnetic material such as aluminum or copper having a plate thickness of 0.3 mm. ing. A non-magnetic material having a plate thickness of 0.3 mm is advantageous for use in a housing having a limited design space such as a mobile phone terminal.

  As for the coil design, it is known that if the coil is separated from the non-magnetic material by about 10 mm, the influence of the non-magnetic material is reduced. However, there are cases where the coil can be separated only by about 5 mm due to restrictions on the arrangement of electronic devices. In such a case, it is also possible to adjust the number of windings of the wire in advance in consideration of the deterioration of the Q value, and increase the Q value of the coil so that there is no problem in actual use.

  In this example using electromagnetic coupling, even if the coupling coefficient k is low, the Q values of the primary and secondary series resonant circuits are increased to increase the degree of freedom in the arrangement of the power transmission coil and the power reception coil. ing. As an example, the coupling coefficient k of the power transmission coil and the power reception coil is set to 0.2 or less, and the Q value of at least one of the primary side coil or the secondary side coil is set to 100 or more. The coupling coefficient k depends on the size of the primary coil in relation to the coil, and the coupling coefficient k increases as the size of the primary coil decreases. It is said.

(Effect of one embodiment)
According to the power receiving coil according to the embodiment described above and the combination of the power receiving coil and the power transmitting coil, there is a degree of freedom in arrangement of the power receiving coil with respect to the power transmitting coil, and power can be received efficiently. That is, the deterioration of the Q value of the power receiving coil when incorporated in an electronic device is reduced, and even when the Q value of the power transmission coil deteriorates when the electronic device is placed on the power transmission coil, the degree of freedom in arrangement is ensured and the power is reduced. Can be realized.

  Moreover, the receiving coil of one Embodiment using a wire for a core is cheaper than the conventional spiral coil. Furthermore, it is possible to manufacture a power receiving coil with less variation in the coil constant (for example, Q value) compared to a conventional spiral coil.

  In the embodiment of the present disclosure, the example in which power is transmitted by the power receiving coil 1 (1A) and the power transmitting coil 11 as illustrated in FIG. 7 has been described, but the present invention is not limited thereto. For example, a repeater coil for making the magnetic flux uniform may be formed in the power transmission coil 11, and power may be transmitted from the power transmission coil 11 to the power receiving coil 1 (1A) via the repeater coil.

<4. Other>
(Another embodiment of the power receiving coil)
Another embodiment of the power receiving coil according to the present disclosure may have the following manufacturing process.
First, the wire 5 covered with the H-shaped core 2 is wound (corresponding to FIG. 3C) (an example of a coil portion). The L value is adjusted by the number of turns. Next, the core 2 around which the wire 5 is wound is inserted into the case of the mold member formed of resin, and is fixed with an adhesive or the like (corresponding to FIG. 3B). Thereafter, the nonmagnetic material 6 is attached to the side surface of the mold member (corresponding to FIG. 3D). Here, the upper surface of the flange portion 2b of the H-shaped core 2 and the lower surface of the flange portion 2c are designed and manufactured so as to be flush with the upper surface and the lower surface of the case of the mold member. When the power receiving coil is manufactured in this way, the height of the H-shaped core 2 and the height of the case of the mold member can be made the same, and thus the thickness can be reduced as compared with the case of molding with resin.

(Contactless power transmission system using the power receiving coil and power transmitting coil of the present disclosure)
A non-contact power transmission system using the power receiving coil and the power transmitting coil of the present disclosure described above will be described.
FIG. 12 is a schematic configuration diagram of a contactless power transmission system including a power receiving coil and a power transmitting coil according to an embodiment of the present disclosure. FIG. 1 shows an example of the most basic circuit configuration (in the case of magnetic field coupling) of a non-contact power transmission system.

The non-contact power supply system of this example includes a power transmission device 31 and a power reception device 41.
The power transmission device 31 includes a signal source 32 including an AC power source 33 and a resistance element 34 that generate an AC signal, a capacitor 35, and a power transmission coil (primary coil) 15. The resistance element 34 illustrates the internal resistance (output impedance) of the AC power supply 33. The capacitor 35 and the power transmission coil 11 are connected to the signal source 32 so as to form a series resonance circuit (an example of a resonance circuit). Then, the capacitance value (C value) of the capacitor 35 and the inductance value (L value) of the power transmission coil 11 are adjusted so as to resonate at the frequency to be measured. The power transmission unit 37 including the signal source 32 and the capacitor 35 transmits power to the power receiving device 41 through the power transmission coil 11 in a non-contact manner (power transmission (power feeding)).

  The power receiving device 41 includes a charging unit 42 including a capacitor 43 (secondary battery) and a resistance element 44, a rectifying unit 48 that converts an AC signal into a DC signal, a capacitor 45, and a power receiving coil (secondary coil) 1. Prepare. The resistance element 44 illustrates the internal resistance (output impedance) of the capacitor 43. The capacitor 45 and the power receiving coil 1 are connected to the charging unit 42 so as to form a series resonance circuit, and the capacitance value (C value) of the capacitor 45 and the inductance of the power receiving coil 1 are set so as to resonate at a frequency to be measured. The value (L value) is adjusted. The power receiving unit 47 including the charging unit 42, the rectifying unit 48, and the capacitor 45 is supplied with electric power from the outside through the power receiving coil 1 (power reception).

  In addition, when the voltage between the power transmission coil 11 and the capacitor 35 constituting the series resonance circuit of the power transmission device 31 is V1 (an example of a voltage applied to the resonance circuit) and the voltage across the power transmission coil 11 is V2, the Q value of the series resonance circuit Is represented by Q = V2 / V1. The same applies to the power receiving device 41 side.

Since FIG. 12 shows a basic circuit including a series resonance circuit, various configurations can be considered as long as the above-described circuit function is provided. For example, in FIG. 12, the capacitor 43 is shown as an example of the load provided in the power receiving device 41, but is not limited to this example. In addition, the power receiving device 41 may include the signal source 32 (power transmission unit 37) and transmit power to the external device via the power receiving coil 1 in a non-contact manner. You may make it receive electric power supply from an external device via the coil 11 non-contactingly. As the power receiving device 41,
Various electronic devices such as a mobile phone terminal and a digital camera can be applied.

  Moreover, although this example demonstrated the series resonance circuit as an example, you may use another resonance circuit as a resonance circuit. For example, the resonance circuit may be configured by connecting the first capacitor in series to the parallel resonance circuit of the second capacitor and the power transmission coil 11. In addition, a resonance circuit may be configured by connecting a second capacitor in parallel to the series resonance circuit of the first capacitor and the power transmission coil 11. The Q value is calculated using the voltage V1 between the power transmission coil 11 and the first capacitor and the voltage V2 across the power transmission coil 11 obtained in each resonance circuit. The series resonance circuit and other resonance circuits described above are examples of the resonance circuit, and are not limited to these configurations.

  Moreover, you may affix the board | substrate which mounted the capacitor | condenser in order to adjust the L value and resonance frequency of a coil to the nonmagnetic material of the aluminum of the receiving coil side surface. Here, both the capacitor for the series resonance circuit and the capacitor for the parallel resonance circuit may be attached to the substrate so that the user can select one of them. Thus, by adjusting the resonance frequency at the time of manufacture as a resonance circuit module, it is not necessary for the user to adjust the frequency. For example, by combining the resonance circuit module with a power receiving unit that can receive an AC voltage of a corresponding resonance frequency, it can be used immediately as a power receiving device.

In addition, this technique can also take the following structures.
(1)
A core having a magnetic material;
A coil portion in which a wire is wound around the core and electromagnetically coupled with an external coil to transmit power;
A non-magnetic material disposed at a certain distance from the side surface of the coil portion;
A power receiving coil comprising:
(2)
The power receiving coil according to (1), wherein the nonmagnetic material has a thickness of 0.3 mm or more.
(3)
Comprising a core having the magnetic body and a resin part containing the coil part;
The power receiving coil according to (1) or (2), wherein the nonmagnetic material is disposed on a side surface of the resin portion.
(4)
The power receiving coil according to any one of (1) to (3), wherein the core has an H shape.
(5)
A core having a magnetic material;
A coil portion in which a wire is wound around the core and electromagnetically coupled with an external coil to transmit power;
A non-magnetic material disposed at a certain distance from the side surface of the coil portion;
A power receiving unit that receives an AC signal via the coil unit;
A power receiving apparatus comprising:
(6)
A power transmission device that generates an AC signal, and a power reception device that receives an AC signal generated by the power transmission device,
The power transmission device is:
A power transmission coil section in which a wire is wound in a planar shape;
A power transmission unit for supplying an AC signal to the power transmission coil unit,
The power receiving device is:
A core having a magnetic material;
A power receiving coil unit in which a wire is wound around the core and electromagnetically coupled to the power transmitting coil unit to transmit electric power;
A nonmagnetic material disposed at a certain distance from the side surface of the power receiving coil portion;
A non-contact power transmission system comprising: a power receiving unit that receives an AC signal via the power receiving coil unit.
(7)
The non-contact power transmission system according to (6), further including a magnetic sheet disposed on a surface of the power transmission coil unit opposite to the power receiving coil unit side.

  As described above, the present disclosure is not limited to each of the above-described embodiments, and various other modifications and application examples can be taken without departing from the gist described in the claims. .

  DESCRIPTION OF SYMBOLS 1,1A ... Power receiving coil, 2 ... Core (H type), 2a ... Shaft core part, 2b, 2c ... Flange part, 3A ... Resin part, 3a ... Side face, 4 ... Air gap part, 5 ... Wire, 6 ... Nonmagnetic material, 11 ... power transmission coil, 12 ... magnetic sheet, 15 ... power reception coil, 16 ... magnetic sheet, 21, 31 ... mobile phone terminal (electronic device), 31 ... power transmission device, 32 ... signal source, 33 ... AC power supply , 34 ... resistor element, 35 ... capacitor, 15 ... power transmission coil, 37 ... power transmission unit, 41 ... power receiving device, 42 ... charging unit, 43 ... capacitor, 44 ... resistance element, 45 ... capacitor, 47 ... power receiving unit, 48 ... Rectifier

Claims (12)

A power receiving coil that receives an AC signal output from a power transmitting coil,
It consists of a magnetic material which has a shaft core part, the 1st flange part provided in the edge part of this shaft core part, and the 2nd flange part provided in the edge part on the opposite side to this 1st flange part. A coil portion in which a wire rod is wound around the shaft core portion of the core, and an outer diameter of the winding of the wire rod is smaller than an outer diameter of the winding of the power transmission coil, and is electromagnetically coupled to the power transmission coil by electromagnetic resonance When,
A resin part having the core and the coil part, and having a side surface separated from the side surface of the coil part by a predetermined distance;
A non-magnetic material disposed on the side surface of the resin portion so as to be parallel to the central axis of the shaft core portion of the core;
A power receiving coil comprising: The power receiving coil according to claim 1, wherein a distance between a side surface of the coil portion and the nonmagnetic material is 5 mm or more. The power receiving coil according to claim 2, wherein a distance between a side surface of the coil portion and the nonmagnetic material is 5 mm to 10 mm. The resin part is a case of a mold member into which the core and the coil part are inserted,
The upper surface of the first flange portion and the lower surface of the second flange portion of the core are configured to be flush with the upper surface and the lower surface of the case, respectively. Power receiving coil. The power receiving coil according to claim 1, wherein a material of the nonmagnetic material is aluminum. The power receiving coil according to claim 1, wherein the nonmagnetic material has a thickness of 0.3 mm or more. The power receiving coil according to claim 1, wherein an amorphous alloy is used as the magnetic material in at least the first flange portion and the second flange portion of the core. The power receiving coil according to claim 1, wherein a substrate on which at least a capacitor for a series resonance circuit or a capacitor for a parallel resonance circuit is mounted is attached to the nonmagnetic material. When the Q value of the power transmission coil is Q ₁ , the Q value of the power reception coil is Q ₂ , the coupling coefficient between the power transmission coil and the power reception coil is k, and the inter-coil efficiency between the power transmission coil and the power reception coil is η _rf ,
η _rf = S ² / [1 + √ {(1 + S ² ) ² }]
However, S = kQ, Q = √ (Q ₁ Q ₂ ) The power receiving coil according to claim 1. A power receiving device that receives an AC signal output from a power transmission coil,
It consists of a magnetic material which has a shaft core part, the 1st flange part provided in the edge part of this shaft core part, and the 2nd flange part provided in the edge part on the opposite side to this 1st flange part. A coil portion in which a wire rod is wound around the shaft core portion of the core, and an outer diameter of the winding of the wire rod is smaller than an outer diameter of the winding of the power transmission coil, and is electromagnetically coupled to the power transmission coil by electromagnetic resonance When,
A resin part having the core and the coil part, and having a side surface separated from the side surface of the coil part by a predetermined distance;
A non-magnetic material disposed on the side surface of the resin portion so as to be parallel to the central axis of the shaft core portion of the core;
A power receiving unit that receives an AC signal via the coil unit;
A power receiving apparatus comprising: A power transmission device that outputs an AC signal and a power reception device that receives an AC signal generated by the power transmission device.
A power transmission coil section in which a wire is wound in a planar shape;
A power transmission unit for supplying an AC signal to the power transmission coil unit,
The power receiving device is:
A core made of magnetic material;
A power receiving coil unit in which a wire is wound around the core and electromagnetically coupled to the power transmitting coil unit to transmit electric power;
A resin portion having the core and the receiving coil portion, and a side surface formed with a predetermined distance away from the side surface of the receiving coil portion;
A nonmagnetic material disposed on the side surface of the resin portion so as to be parallel to the central axis of the core;
A non-contact power transmission system comprising: a power receiving unit that receives an AC signal via the power receiving coil unit. The core includes a shaft core portion around which the wire is wound, a first flange portion provided at an end portion of the shaft core portion, and a second portion provided at an end portion opposite to the first flange portion. And a flange portion of
The power receiving coil portion has an outer diameter of the winding of the wire smaller than an outer diameter of the winding of the power transmission coil portion, and is electromagnetically coupled to the power transmission coil portion by electromagnetic resonance,
The non-contact power transmission system according to claim 11, wherein the non-magnetic body is disposed on the side surface of the resin portion so as to be parallel to a central axis of the shaft core portion of the core.

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