JP2015109762A - Non-contact power transmission apparatus and non-contact power transmission method - Google Patents

Abstract

[PROBLEMS] To increase the distance in which power can be transmitted from a power transmission coil and to enable stable power transmission corresponding to the distance between coils in a region shorter than the distance between coils that is in a critical coupling state (bimodal characteristic region). And A power transmission device having a power transmission coil, a power reception device having a power reception coil, and a power transmission auxiliary device having an auxiliary coil, wherein the power reception coil is disposed in a power reception space formed between the power transmission coil and the auxiliary coil. A contactless transmission apparatus that performs power transmission is further characterized by further including a mechanism system capable of moving at least one of the power transmission coil and the auxiliary coil in order to adjust the distance between the power transmission coil and the auxiliary coil. [Selection] Figure 4

Description

  The present invention relates to a non-contact power transmission system and a non-contact power transmission method for transmitting power in a non-contact (wireless) manner via a power transmission coil provided in a power transmission device and a power reception coil provided in a power reception device.

  As a method of transmitting power in a non-contact manner, an electromagnetic induction type by electromagnetic induction (several hundreds of kHz), an electric field / magnetic field resonance type by transmission between LC resonances via electric field or magnetic field resonance, a microwave power transmission type by radio waves (several GHz), Alternatively, a laser power transmission type using electromagnetic waves (light) in the visible light region is known. Among them, the electromagnetic induction type has already been put into practical use. This has the advantage that it can be realized with a simple circuit (transformer system), but there is also a problem that the transmission distance is short.

  Therefore, recently, electric field / magnetic field resonance type power transmission capable of short-distance transmission (up to 2 m) has attracted attention. Among these, in the case of the electric field resonance type, when a hand or the like is put in the transmission path, the human body is a dielectric, so that energy is absorbed as heat and dielectric loss occurs. On the other hand, in the case of the magnetic resonance type, the human body hardly absorbs energy, and dielectric loss can be avoided. From this point of view, attention to the magnetic resonance type has been increasing.

  Here, when electric power is transmitted and received in a non-contact manner by the magnetic field resonance type, for example, when there is an obstacle 10 such as a glass window or a wall between the power transmission coil 4 and the power reception coil 7 as shown in FIG. The distance between the power transmission coil 4 and the power reception coil 7 differs depending on the thickness.

  If the distance between the power transmission coil 4 and the power reception coil 7 is different, the coupling state between both the power transmission coil 4 and the power reception coil 7 changes, and the frequency dependence of the power transmission efficiency changes. For example, when the distance is long and the coupling state is weak, the power transmission efficiency is a single peak characteristic having one peak as schematically shown in FIG. However, as the distance decreases and the coupling coefficient approaches 1, the influence of the mutual inductance increases, and as shown schematically in FIG. 8B, the bimodal characteristic (tight coupling) having two peaks, f0L and f0H. )

  As described above, when the power transmission coil 4 and the power reception coil 7 are brought close to each other, a bimodal characteristic is obtained. Therefore, even when power is supplied from a high-frequency power source at an original arbitrary frequency, the frequency is not a resonance frequency and the response is lowered. As a result, the transmission power decreases. This means that the efficiency of power supply from the power transmission side changes depending on the distance between the coils. In such a situation, if the frequency of the high-frequency power remains constant, it is far from the resonance point, and high-efficiency power transmission is impossible. Therefore, in order to obtain good power receiving power in both FIG. 7A and FIG. 7B, various optimization adjustments are made according to the distance between the power transmitting coil 4 and the power receiving coil 7 (t1 and t2 in this figure). It becomes necessary.

  In Patent Document 1, a plurality of power transmission coils and power reception coils are used so that the maximum power transmission efficiency is always obtained even when the inter-coil distance is changed. A configuration in which a resonance frequency exists is disclosed. With respect to a change in distance in the usable distance range between the power transmission coil and the power reception coil, two or more resonance frequencies are sequentially arranged so as to coincide with the power transmission frequency.

  Since it has at least three different resonance frequencies, the frequency bandwidth of resonance can be broadened as a whole. As a result, even if the distance between the power transmission coil and the power reception coil changes and the three resonance frequencies change, the resonance frequency sequentially matches the power transmission frequency, so that the transmission efficiency does not decrease. .

JP 2011-205757 A

  In the case of the configuration of Patent Document 1, there is a region in which sufficient power transmission efficiency cannot be obtained with respect to a change in the distance between the power transmission coil and the power reception coil when there are few resonance frequencies. This is determined by the relationship between the amount of change in the inter-coil distance and the interval between adjacent resonance frequencies. In order to solve such a problem, it is necessary to arrange a large number of coils, resulting in an increase in apparatus cost. In addition, various coils may affect each other magnetically, and as a result, power transmission efficiency may be reduced.

  In addition, since the power transmission frequency and the self-resonance frequency of the power receiving coil in the critical coupling state do not coincide with each other, there is a problem that the power transmission efficiency is lowered at the distance between the coils in the critical coupling state. The critical coupling state refers to a boundary state where the frequency dependency of the power transmission efficiency changes from a single peak characteristic to a bimodal characteristic, and is a combined state in which the peak of the single peak is maximized.

  The present invention solves such problems in the prior art, and expands the distance at which power can be transmitted from the power transmission coil, and is an area shorter than the distance between the coils that is in a critically coupled state (bimodal characteristic area). However, it is an object of the present invention to provide a non-contact power transmission device and a non-contact power transmission method that enable stable power transmission corresponding to the distance between the power transmission coil and the power reception coil.

  A non-contact power transmission device according to the present invention includes a power transmission device having a power transmission resonator configured by a power transmission coil and a resonance capacitor, a power reception device having a power reception resonator configured by a power reception coil and a resonance capacitor, an auxiliary coil, and a resonance A power transmission auxiliary device having an auxiliary resonator constituted by a capacitor, the power transmission device and the power transmission auxiliary device are opposed to each other, and the power reception coil is disposed in a power reception space formed between the power transmission coil and the auxiliary coil. It arrange | positions and transmits electric power from the said power transmission apparatus to the said power receiving apparatus.

  In order to solve the above problems, a non-contact power transmission device according to the present invention has a power transmission auxiliary device having an auxiliary resonator constituted by an auxiliary coil and a resonant capacitor, and a constant coil-to-coil distance between the power transmission coil and the auxiliary coil. A coil moving mechanism for maintaining the power transmission device, wherein the power transmission device and the power transmission auxiliary device are opposed to each other, and the power reception coil is disposed in a power reception space formed between the power transmission coil and the auxiliary coil so as to perform power transmission. The coil moving mechanism is configured to adjust the inter-coil distance in the axial direction between the power transmission coil and the auxiliary coil.

  It is preferable that the inter-coil distance between the power transmission coil and the auxiliary coil is adjusted so that the power received from the power transmission device to the power reception device is maximized.

  Further, the non-contact power transmission method of the present invention uses a power transmission device having a power transmission resonator constituted by a power transmission coil and a resonance capacitor, and a power reception device having a power reception resonator constituted by a power reception coil and a resonance capacitance, A method for transmitting electric power from a power transmitting device to a power receiving device via an action between a power transmitting coil and a power receiving coil, further using a power transmission auxiliary device having an auxiliary resonator composed of an auxiliary coil and a resonant capacitor, By adjusting the position of the power transmission coil or auxiliary coil so that the distance between the coil of the power transmission coil and the auxiliary coil is constant even if the distance between the power transmission coil and the power reception coil changes, the power received from the power transmission device to the power reception device can be reduced. It is characterized by optimization.

  According to the present invention, when the distance between the power transmission coil and the power receiving coil is changed by providing the resonance auxiliary device and performing power transmission to the power receiving coil in a state where the distance between the power transmission coil and the auxiliary coil is kept constant. However, stable power transmission is possible. In addition, by adjusting the resonance frequency of the auxiliary resonator in advance, stable power transmission is possible even in a region shorter than the distance between the power transmission coil and the auxiliary coil that is in a critically coupled state (bimodal characteristic region).

Schematic cross-sectional view showing the configuration of the non-contact power transmission apparatus in the first embodiment The graph which shows the relationship of the output electric power P of a rectifier circuit with respect to the distance X between the power transmission coil in a coil center, and a receiving coil of the non-contact electric power transmission apparatus. Schematic cross-sectional view showing the positional relationship among a power transmission coil, a power reception coil, and an auxiliary coil when using glass windows with different thicknesses in the first embodiment Schematic sectional view showing the positional relationship between the power transmission coil, the power reception coil, and the auxiliary coil and the mechanism system for moving the auxiliary coil when the glass windows having different thicknesses in the first embodiment are used. Schematic cross-sectional view showing the positional relationship among a power transmission coil, a power reception coil, and an auxiliary coil when using glass windows with different thicknesses in the second embodiment Schematic sectional view showing the positional relationship between the power transmission coil, the power reception coil, and the auxiliary coil and the mechanism system for moving the power transmission coil when the glass windows having different thicknesses in the second embodiment are used. Schematic sectional view showing the positional relationship between the power transmission coil and the power reception coil when using glass windows with different thicknesses in the prior art Schematic diagram showing the relationship between frequency and power transmission efficiency due to differences in coupling state (corresponding to the distance between the power transmission coil and the power reception coil) in the prior art

  The non-contact power transmission apparatus of the present invention can take the following aspects based on the above configuration.

  A power receiving coil is arranged in a power receiving space formed between the power transmitting coil and the auxiliary coil with the power transmitting coil and the auxiliary coil facing each other, and is configured to perform power transmission, and through magnetic field resonance between the power transmitting coil and the power receiving coil. Then, power is transmitted from the power transmission apparatus to the power reception apparatus.

  By adjusting the resonance capacity of the auxiliary resonator of the power transmission auxiliary device, the resonance frequency of the auxiliary resonator can be adjusted, and as a result, the strength of the magnetic field in the power receiving space can be controlled.

  At this time, the electromagnetic coupling state between the power transmission resonator of the power transmission device and the auxiliary resonator of the power transmission auxiliary device is a bimodal characteristic state (tightly coupled state), and within the distance between the coils of the power transmission coil and the auxiliary coil, It is preferable that the resonance frequency f1, the resonance frequency f2 of the power receiving resonator, and the resonance frequency f3 of the auxiliary resonator are set so as to satisfy a relationship of f1 = f2 <f3 or f3 <f1 = f2. That is, in the present invention, the resonance frequency f3 of the auxiliary coil is different from the resonance frequency f1 of the power transmission coil and the resonance frequency f2 of the power reception coil, and in particular, the power transmission efficiency can be increased when the resonance frequency f3 is the highest. .

  More preferably, when the resonance frequency of the high-frequency power driver for supplying power to the power transmission coil is f0, f0 = f1 = f2 <f3 is set. That is, the power transmission efficiency can be maximized by setting the resonance frequency f0 of the high-frequency power driver to the same frequency as the resonance frequency f2. The resonance frequency f1 of the power transmission coil is preferably the same as f0.

  Note that a specific function of the power transmission auxiliary device 3 and a method for adjusting the resonance frequency and the like are described in Japanese Patent Application Laid-Open No. 2013-85436 filed earlier.

  According to the present invention, the position of the power transmission coil or the auxiliary coil can be moved while the strength of the magnetic field in the power receiving space is optimized by adjusting the resonance capacity of the auxiliary resonator of the power transmission auxiliary device as described above. A mechanism system that can be used is provided. Even when the distance between the power transmission device and the power reception device changes depending on the attachment location of the non-contact power transmission device, the distance between the power transmission coil and the auxiliary coil can be made the optimum distance by adjusting the mechanical system. In adjusting the mechanical system, a detector for monitoring the received power can be provided, and the position of the power transmission coil or auxiliary coil can be adjusted so that the received power is maximized.

  It is preferable that the diameter d1 of the power transmission coil, the diameter d2 of the power reception coil, and the diameter d3 of the auxiliary coil satisfy the relationship of d1> d2 and d2 <d3. If this relationship is maintained, it is effective in increasing the power transferable distance. In particular, it is preferable that the relationship d1 = d3 is satisfied. Thereby, a great effect can be obtained with respect to improvement of transmission efficiency characteristics such as expansion of the power receiving range. Of course, the same effect can be obtained not only in the case of a circular coil but also in a form in which a rectangular coil or the like is arranged. A planar coil is preferable because it can be thinned. Moreover, it is preferable that the central axis of the power transmission coil, the central axis of the auxiliary coil, and the central axis of the power receiving coil are on the same axis.

  Further, the central axes of both coils may be coaxially arranged on the same plane, and the power receiving coil diameter d2 and the auxiliary coil diameter d3 may be configured such that d2 <d3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each embodiment is an example for embodying the present invention, and the present invention is not limited to these.

<Embodiment 1>
FIG. 1 is a schematic diagram illustrating a configuration of a magnetic field resonance type non-contact power transmission apparatus according to the first embodiment. The non-contact power transmission device of the present invention includes a power transmission device 1 and a power reception device 2, and is characterized by including a power transmission auxiliary device 3 in the power reception device 2.

  The power transmission device 1 includes a power transmission coil 4 and a high-frequency power driver 5. The high-frequency power driver 5 converts the power of the AC power source 6 into high-frequency power that can be transmitted, and supplies the power transmission coil 4 with the high-frequency power. The high frequency power is transmitted to the power receiving coil 7 of the power receiving device 2 through the power transmitting coil 4.

  The power transmission device 1 may be provided with a power transmission loop coil. Although illustration is omitted, a resonance capacitor is connected to the power transmission coil 4, and the power transmission coil 4 and the resonance capacitor constitute a power transmission resonator. As the resonance capacitance, a variable capacitor (variable capacitor or trimmer capacitor) or a fixed capacitor may be connected, or a configuration using a stray capacitance may be used.

  The power receiving device 2 includes at least a power receiving coil 7 and a power transmission auxiliary device 3. A power receiving loop coil may be provided near the power receiving coil 7. The high frequency power transmitted from the power transmission coil 4 to the power reception coil 7 is stored in the rechargeable battery of the load via, for example, a power reception circuit equipped with a rectifier circuit. You may make it the structure which transmits electric power directly to a load, without using a rechargeable battery. Although details are not shown in FIG. 1, as will be described in detail later, the power receiving device 2 is provided with a mechanism system that can move the auxiliary coil 8 in the axial direction.

  The power transmission auxiliary device 3 includes an auxiliary resonator including an auxiliary coil 8 and an adjustment capacitor 9. The adjusting capacitor 9 may be constituted by connecting a plurality of variable capacitors (variable capacitors or trimmer capacitors) or fixed capacitors. However, the method of adjusting the resonance frequency of the auxiliary resonator is not limited to the method of adjusting the capacitance of the adjustment capacitor 9.

  Next, the function of the power transmission auxiliary device 3 that is a feature of the present embodiment will be described. When the distance between the power transmission coil 4 and the auxiliary coil 8 is sufficiently large, the coupling force between the power transmission resonator and the auxiliary resonator is weak, and the mutual inductance can be almost ignored. In this case, the resonance frequency ft of the power transmission side resonance system has a single peak characteristic having the same peak as the resonance frequency f1 of the power transmission device 1 (loosely coupled state). The transmission-side resonance system is a resonance system configured by magnetic coupling of a power transmission resonator that is configured by the power transmission coil 4 and the resonant capacitor, and an auxiliary resonator that is configured by the auxiliary coil 8 and the resonant capacitor. . On the other hand, when the distance between the power transmission coil 4 and the auxiliary coil 8 is short, the coupling force between the power transmission resonator and the auxiliary resonator is strong, and the mutual inductance cannot be ignored. In this case, the resonance frequency of the transmission-side resonance system has two peaks, and has a bimodal characteristic in which the lower frequency is ftL and the higher frequency is ftH (tightly coupled state).

  As described above, when the distance between the power transmission coil and the power reception coil is short and the frequency characteristic of the power transmission efficiency is a bimodal characteristic, the frequency at which the maximum transmission efficiency is obtained is not the resonance frequency ft. Since the transmission efficiency at the frequency ft in the bimodal characteristics changes depending on the distance between the power transmission coil and the power reception coil, there is a problem that high-efficiency power transmission cannot be performed if the frequency of the high-frequency power in the power transmission device remains constant. .

  In the present invention, the adjustment capacitor 9 having a variable capacity is used as a capacitor connected to the auxiliary coil 8, and the resonance frequency f 3 of the power transmission auxiliary device 3 is changed by adjusting the capacity of the adjustment capacitor 9. The resonance frequency ft of the resonance system is changed. As a result, the strength of the magnetic field in the power receiving space formed by the power transmission coil 4 and the auxiliary coil 8 can be controlled. Note that a specific function of the power transmission auxiliary device 3 and a method for adjusting the resonance frequency and the like are described in Japanese Patent Application Laid-Open No. 2013-85436 filed earlier.

  In order to sufficiently obtain the control function of the magnetic field strength in the power receiving space by the power transmission auxiliary device 3, the auxiliary coil 8 constituting the power transmission auxiliary device 3 is substantially the same as the shape of the power transmission coil 4, and the central axis of both coils Also, it is desirable to arrange them almost coaxially.

  If the power transmission auxiliary device 3 is used, the transmission distance of power can be increased. For this purpose, when the diameter of the power transmission coil 4 is d1, the diameter of the power reception coil 7 is d2, and the diameter of the auxiliary coil 8 is d3, the relationship of d1> d2 and d2 <d3 may be satisfied. If the diameter d1 of the power transmission coil 4 is larger than the diameter d2 of the power receiving coil 7, the magnetic flux between the auxiliary coil 8 can be used effectively, and the diameter d3 of the auxiliary coil 8 is equal to the diameter d2 of the power receiving coil 7. This is because the magnetic flux between the power transmission coil 4 can be used as long as it is larger.

  FIG. 2 shows the relationship between the distance X from the power transmission coil 4 to the power reception coil 7 and the output power of the rectifier circuit in the power reception circuit by actually performing power transmission using the non-contact power transmission device of FIG. It is a graph of a result. Note that the output power of the rectifier circuit corresponds to the received power. Here, the resonance frequency in each resonator is the same as f1 of the power transmission device 1, f2 of the power reception device 2, and the resonance frequency f0 of the high-frequency power driver 6, all at 13.6 MHz. The distance Z between the power transmission coil 4 and the auxiliary coil 8 was fixed to 50 mm, and the measurement was performed without the obstacle 10. In order to examine the change in the received power according to the position of the power receiving coil 7, the power receiving coil 7 was moved in the distance Z direction within the power receiving space formed by the power transmitting coil 4 and the auxiliary coil 8. At this time, the distance from the power transmission coil 4 to the power reception coil 7 was set to X. Then, by changing the capacitance of the adjustment capacitor 9 connected to the auxiliary coil 8, the resonance frequency f3 of the power transmission auxiliary device 3 is set to 12 MHz, 13 MHz, 13.6 MHz, 14 MHz, and 15 MHz, respectively. The relationship between the distance X and the received power was measured.

  As a result, as shown in FIG. 2, when the resonance frequency f3 of the power transmission auxiliary device 3 is 12 MHz, it is understood that the received power is almost zero in the region where the distance X = 35 mm or more. This is because the mutual inductance between the power transmission resonator and the auxiliary resonator is almost negligible, and the resonance frequency f1 of the power transmission device 1 is the resonance frequency ft of the power transmission side resonance system.

  When the resonance frequency f3 of the power transmission auxiliary device 3 is 13 MHz and is increased by 1 MHz, the mutual inductance between the power transmission resonator and the auxiliary resonator increases, and the received power becomes the lowest in the vicinity of the distance X = about 30 mm.

  When the resonance frequency f3 of the power transmission auxiliary device 3 is the same resonance frequency (13.6 MHz) as the resonance frequency f1 of the power transmission device 1, the received power is the smallest and the distance X is large in the region where the distance X close to the power transmission coil 4 is small. As the power increases, the received power increases and becomes the largest in the region near the auxiliary coil 8.

  When the resonance frequency f3 of the power transmission auxiliary device 3 is 14 MHz, high power reception power can be obtained regardless of the position in the power reception space where the power reception coil 7 is formed by the power transmission coil 4 and the power transmission auxiliary coil 8. That is, when the distance Z between the power transmission coil 4 and the auxiliary coil 8 is constant, stable power reception can be achieved even if the position of the power reception coil 4 in the power reception space is changed by setting the resonance frequency f3 of the power transmission auxiliary device to an appropriate value. You can get power.

  When the resonance frequency f3 of the power transmission auxiliary device 3 is 15 MHz, it can be seen that the received power decreases as the distance X increases. This is considered because the mutual inductance of the power transmission resonator and the auxiliary resonator is reduced.

  Thus, by appropriately setting the resonance frequency f3 of the power transmission auxiliary device 3, it is possible to control the strength of the magnetic field in the power receiving space, and the power received according to the position of the power receiving coil 4 in the power receiving space. It can be seen that it can be controlled.

  The present invention is set to a condition (for example, f3 = 14 MHz in the condition of FIG. 2) such that the power received in the power receiving space is uniformly obtained using the power transmission auxiliary device, and the distance between the power transmitting coil and the power receiving coil is Even if it changes, it should be possible to obtain uniform power reception.

  As shown in FIG. 3A, the thickness d1 of the window glass, the wall, etc., under the condition that the uniform power receiving power as described above is obtained when the inter-coil distance between the power transmission coil 4 and the auxiliary coil 8 is Z1. When the power transmission coil 4 and the power reception coil 7 are provided opposite to each other on the obstacle 10, the inter-coil distance D1 between the power reception coil 7 and the auxiliary coil 8 satisfies the relationship D1 = Z1-d1.

  On the other hand, when the thickness of the obstacle 11 is increased from d1 to d2 as shown in FIG. 3B, the distance between the coil between the power transmission coil 4 and the auxiliary coil 8 needs to be Z1, The inter-coil distance between the coil 7 and the auxiliary coil 8 decreases from D1 to D2.

  By the way, when the power receiving coil 7 and the auxiliary coil 8 are integrally provided in the power receiving device 2 as shown in FIG. 1, the same distance (Z2≈Z1) as the inter-coil distance Z1 between the power transmitting coil 4 and the auxiliary coil 8. In order to achieve this, it is necessary to change the inter-coil distance between the power receiving coil 7 and the auxiliary coil 8 in the power receiving device 2 from D1 to D2.

  Therefore, in the first embodiment, a mechanism system capable of changing the position of the auxiliary coil 8 is provided in the power receiving device 2 as shown in FIG. That is, as shown in FIG. 4A to FIG. 4B, when the thickness of the obstacle increases from t1 to t2, a mechanism system 12 that can move the auxiliary coil 8 in the axial direction. By adjusting the distance, the distance between the power receiving coil 7 and the auxiliary coil 8 can be shortened from D3 to D4. As a result, the inter-coil distance between the power transmission coil 4 and the auxiliary coil 8 can be set to a predetermined distance (Z4≈Z3). Thereby, even when the thickness of the obstacle is changed, good received power can be obtained.

  As a method for obtaining the optimum distance Z4, the auxiliary coil 8 is coiled by adjusting the mechanical system 12 of the power receiving device 2 after attaching the power transmitting device 1 and the power receiving device 2 to the obstacle 11 of FIG. And may be fixed at an optimum position based on a display such as a lamp (not shown) provided in the power receiving device 2. For example, a position where the lamp is lit brightest, a position where a predetermined lamp is lit, etc. may be used. That is, the received power is monitored by a power transmission circuit or a power receiving circuit, and the auxiliary coil 8 may be fixed at a position where the received power is maximized. Here, as a means for moving the auxiliary coil 8, the mechanical system 12 may be moved manually or automatically by a motor or the like. The display lamp may be provided in the power transmission device 1.

  As an example of the mechanism system 12, the auxiliary coil 8 can be moved in the axial direction by tapping a screw inside the hole provided in the power receiving device 2 with a tap, inserting the screw into the screw hole, and rotating the screw.

  Moreover, as a method of attaching the power transmission device 1 and the power reception device 2 to an obstacle, an adsorption board or a magnet, and in some cases, an adhesive or a screw is used. Further, when the obstacle thickness (t1 or t2) is known in advance, a memory is attached to the mechanism system 12 and only the difference in the obstacle thickness (t2-t1) is used to assist the mechanism system 12. The coil 8 may be moved (D3-D4). If the thickness of the obstacle 11 is not known, a laser may be used for a window glass, and ultrasonic waves may be used for a wall such as concrete before attachment. As described above, the power receiving power can be optimized only by mechanical operation.

<Embodiment 2>
Also in the second embodiment, the power transmission auxiliary device 3 is provided in the power receiving device 2 as in the first embodiment. In that respect, the basic configuration is the same as in FIG. However, the second embodiment is different from the first embodiment in that the power transmission device 1 is provided with a mechanism system that moves the position of the power transmission coil. That is, by setting a condition (for example, f3 = 14 MHz in the condition of FIG. 2) such that the received power in the receiving space is uniformly obtained using the power transmission auxiliary device, the position of the power transmission coil is moved, thereby Even if the thickness of the object changes, good power receiving power can be obtained.

  As shown in FIG. 5A, the power receiving coil 7 is provided in contact with an obstacle 10 such as a window glass or a wall, and the distance between the power receiving coil 7 and the auxiliary coil 8 is fixed (distance D5). At this time, when the distance Z5 between the power transmission coil 4 and the auxiliary coil 8 is a condition for obtaining a uniform power reception, the thickness of the obstacle 11 is increased from t1 to t2 as shown in FIG. 5B. In this case, the inter-coil distance between the power transmission coil 4 and the power reception coil 7 must not be changed (d5 = d6). However, the distance between the power transmission coil 4 and the obstacle 11 is shortened.

  Therefore, in the second embodiment, the distance between the power transmission coil 4 and the obstacle 11 is adjusted by changing the position of the power transmission coil 4. As shown in FIG. 6, the power transmission device 1 is provided with a mechanism system 13 that can change the position of the power transmission coil 4. That is, as shown in FIG. 6A to FIG. 6B, when the thickness of the obstacle increases from t1 to t2, a mechanism system 13 that can move the power transmission coil 4 in the axial direction. By adjusting the distance, the inter-coil distance between the power transmission coil 4 and the auxiliary coil 8 can be set to a predetermined distance (Z8≈Z7). Thereby, even when the thickness of the obstacle is changed, good received power can be obtained.

  As a method for obtaining the optimum distance Z8, the power transmission coil is obtained by adjusting the mechanical system 13 provided in the power transmission device 1 after attaching the power transmission device 1 and the power reception device 2 to the obstacle 11 in FIG. What is necessary is just to move 4 to the axial direction of a coil, and to fix in the optimal position based on the display of the lamp etc. which are not shown in the power receiving apparatus 2. For example, a position where the lamp is lit brightest, a position where a predetermined lamp is lit, etc. may be used. That is, the received power is monitored by the power transmission circuit or the power reception circuit, and the power transmission coil 4 may be fixed at a position where the received power is maximized. Here, as a means for moving the power transmission coil 4, the mechanism system 13 may be moved manually or automatically by a motor or the like. The display lamp may be provided in the power transmission device 1.

  As an example of the mechanical system 13, the power transmission coil 4 can be moved in the axial direction by tapping a screw inside the hole provided in the power transmission device 1 with a tap, inserting the screw into the screw hole, and rotating the screw.

  Here, as a method of attaching the power transmission device 1 and the power reception device 2 to an obstacle, an adsorption board or a magnet, and in some cases, an adhesive or a screw is used. If the thickness of the obstacle (t1 or t2) is known in advance, a memory is attached to the mechanical system 13 and power is transmitted using the mechanical system 13 by the difference in the thickness of the obstacle (t2-t1). The coil 4 may be moved. If the thickness of the obstacle 11 is not known, a laser may be used for a window glass, and ultrasonic waves may be used for a wall such as concrete before attachment. As described above, the power receiving power can be optimized only by mechanical operation.

  In the first and second embodiments described above, the resonance frequency is in the MHz band, but the same effect can be obtained even in the KHz band (for example, f1 is 100 kHz).

  As described above, according to the present invention, even when the distance between the power transmission coil 4 and the power reception coil 7 is changed, stable power transmission is possible only by moving the position of the power transmission coil 4 or the auxiliary coil 8. Since it is not necessary to provide a means for adjusting the resonance frequency in the power receiving device and the power transmitting device, the cost of the power transmitting device and the power receiving device can be reduced.

  In the first embodiment, the mechanical system is provided in the power transmission auxiliary device, and in the second embodiment, the mechanical system is provided in the power transmission device. However, both the power transmission auxiliary device and the power transmission device are provided with the mechanical system. The effect similar to the above can be obtained by adjusting the distance between the coil of the power transmission coil and the auxiliary coil.

  The non-contact power transmission device of the present invention is capable of stable power transmission even when the distance between the power transmission coil and the power reception coil changes, and is suitable for non-contact power transmission when there is an obstacle such as a window glass or a wall. It is.

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Power receiving device 3 Power transmission auxiliary device 4 Power receiving coil 5 High frequency power driver 6 AC power supply 7 Power receiving coil 8 Auxiliary coil 9 Adjustment capacitors 10, 11 Obstacles 12, 13

Claims (3)

A power transmission device having a power transmission resonator constituted by a power transmission coil and a resonance capacitor, a power reception device having a power reception resonator constituted by a power reception coil and a resonance capacitance, and an auxiliary resonator constituted by an auxiliary coil and a resonance capacitance A power transmission auxiliary device, wherein the power transmission device and the power transmission auxiliary device are opposed to each other, and the power reception coil is disposed in a power reception space formed between the power transmission coil and the auxiliary coil. In a non-contact power transmission device that transmits power to
Non-contact power transmission, comprising: a coil moving mechanism for adjusting a distance between the power transmission coil and the auxiliary coil by moving at least one of the power transmission coil or the auxiliary coil in the axial direction of the coil. apparatus.   The contactless power transmission device according to claim 1, wherein a distance between the power transmission coil and the auxiliary coil is adjusted so that a power reception power supplied from the power transmission device to the power reception device is maximized. . A power transmission device having a power transmission resonator constituted by a power transmission coil and a resonance capacitor, a power reception device having a power reception resonator constituted by a power reception coil and a resonance capacitance, and an auxiliary resonator constituted by an auxiliary coil and a resonance capacitance A power transmission auxiliary device, wherein the power transmission device and the power transmission auxiliary device are opposed to each other, and the power reception coil is disposed in a power reception space formed between the power transmission coil and the auxiliary coil. In a non-contact power transmission device that transmits power to
Regardless of the distance between the power transmission coil and the power reception coil, the power reception power supplied from the power transmission apparatus to the power reception apparatus is optimized by adjusting the distance between the coils in the axial direction of the power transmission coil and the auxiliary coil. Non-contact power transmission method.

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