JP2022071537A - Coil, power transmission device and power receiving device, and power transmission system - Google Patents

Abstract

To provide a coil and the like that can reduce the weight while reducing various costs as a coil for wireless power transmission, and can improve the transmission efficiency as a coil and prevent the operating temperature from rising.SOLUTION: In a power receiving loop coil RL1 used for non-contact type power transmission and composed of winding of a copper thin film wire RL11 and a copper thin film wire RL12, the thickness of a portion of a copper thin film wire RL11 and the copper thin film wire RL12 having relatively high density of a current flowing during power transmission is configured to be thicker than the thickness of a portion of the copper thin film wire RL11 and the copper thin film wire RL12 having relatively low density of the current.SELECTED DRAWING: Figure 2

Description

The present invention belongs to the technical fields of coils, power transmission devices and power receiving devices, and power transmission systems, and more specifically, coils for non-contact power transmission, non-contact power transmission devices and power receiving devices using the coils, and power receiving devices. It belongs to the technical field of power transmission systems.

In recent years, electric vehicles equipped with storage batteries such as lithium-ion batteries have become widespread. In such an electric vehicle, the electric power stored in the storage battery is used to drive and move the motor, so that the storage battery is required to be charged efficiently. Therefore, as a method of charging the storage battery mounted on an electric vehicle without physically connecting a charging plug or the like, so-called wireless power transmission using a power receiving coil and a power transmission coil that are separated from each other and opposed to each other is used. Is being researched. The wireless power transmission method generally includes an electric field coupling method, an electromagnetic induction method, a magnetic field resonance method, and the like. When these methods are compared from the viewpoints of, for example, the frequency of power transmitted and received, the degree of positional freedom in each of the horizontal and vertical directions, and the transmission efficiency, wireless power for charging the storage battery mounted on the electric vehicle is used. As a transmission method, an electric field coupling method using a capacitor or a magnetic field resonance method using a coil is promising, and research and development on these are being actively carried out. Examples of the prior art document that discloses such a background technique include the following Patent Document 1. Patent Document 1 discloses a coil that transmits power by a magnetic field resonance method using a one-turn (1 turn) loop coil and a 5.5-turn (5.5 turn) open coil. ing.

Japanese Unexamined Patent Publication No. 2011-2000

On the other hand, the above-mentioned wireless power transmission (contactless power supply) for electric vehicles requires transmission of high output power of at least 3.7 kW (that is, flowing through a coil). Therefore, if the resistance of the conductor (coil) becomes high as a result of passing such high output power (current), the loss as a coil becomes large due to the generation of Joule heat, and the efficiency of wireless power transmission is lowered. It will be.

Therefore, as a method for reducing the resistance caused by the loss of the coil, it is conceivable to configure the coil itself by using a stranded wire (so-called litz wire). However, considering that the power receiving coil is mounted on a private car, the configuration of the coil using the stranded wire leads to an increase in weight and a high price of the coil. As a conventional technique for solving this problem, for example, a core material obtained by laminating a thin film made of copper and an insulating layer that insulates between the thin films is patterned and etched into the shape of the coil by using a so-called photolithography method. Then, it is conceivable to manufacture a laminated coil by stacking a plurality of layers of the etched core material and conducting conduction connection between the layers.

On the other hand, the frequency of the power transmitted and received by the wireless power transmission is predetermined by, for example, by law for each device responsible for the wireless power transmission, and is set to a high frequency of 85 kHz in the case of power transmission to the electric vehicle. Here, it is generally known that when a high-frequency current is passed through a conductor, the current density is high on the surface of the conductor and decreases toward the center of the conductor. Regarding this point, the higher the frequency of the current, the more the current concentrates on the surface, and as a result, the AC resistance of the conductor increases. This phenomenon is known as the so-called "skin effect of conductors". In the following description, the AC resistance in the conductor when a high frequency current is passed through the conductor is simply referred to as "impedance". Then, in the above-mentioned wireless power transmission, when an attempt is made to transmit a high-output power while using a high-frequency (for example, the above-mentioned 85 kilohertz) current, the conductor (coil) is caused by the above-mentioned skin effect as a result of passing the high-output power (current). ) Further increases, the loss as a coil due to the Joule heat increases, and this also reduces the efficiency of wireless power transmission.

Further, as an electrical phenomenon that reduces the efficiency of wireless power transmission as in the above skin effect, the so-called "conductor proximity effect" caused by the proximity of conductors in winding as a coil is Can be mentioned. Therefore, it is necessary to take measures against the increase in impedance due to this proximity effect.

Therefore, as a method of using a thin film and reducing the impedance due to heat generation caused by the loss of the laminated coil, it is conceivable to thicken the thin film itself to increase its cross-sectional area. The same problems of weight increase and price increase as when using a stranded wire occur.

Therefore, the present invention has been made in view of the above problems and requirements, and one example of the problem is that the coil can be reduced in weight while reducing various costs as a coil for wireless power transmission, and as a coil. It is an object of the present invention to provide a coil capable of improving the transmission efficiency and preventing an increase in the operating temperature, a non-contact type power transmission device and a power receiving device using the coil, and a power transmission system.

In order to solve the above problems, the invention according to claim 1 is a coil used for non-contact type power transmission, which is perpendicular to the winding direction of the coil and the direction in the winding surface of the coil. The winding line having a length in the first direction longer than the length in the second direction perpendicular to the winding surface is provided, and the density of the current flowing through the winding line during power transmission is relatively high. The length of the winding line portion in the second direction is configured to be longer than the length of the winding line portion having a relatively low density in the second direction.

According to the first aspect of the invention, in a winding line having a length in the first direction longer than the length in the second direction, the length of the winding line having a relatively high current density in the second direction is increased. Since the density is longer than the length of the portion of the winding line having a relatively low density in the second direction, it is possible to reduce the AC resistance due to the so-called skin effect or proximity effect in the winding line for weight reduction and cost reduction. It is possible to achieve both weight reduction and cost reduction, improvement of transmission efficiency, and prevention of an increase in operating temperature. Further, since the AC resistance can be reduced without increasing the length of the winding line in the first direction, it is possible to reduce the size of the coil as a whole, particularly the plan view shape.

In order to solve the above problems, the invention according to claim 2 comprises the coil according to claim 1, wherein the winding line is formed by winding a thin film wire made of a conductor, and as the first direction. The thickness of at least one of the widthwise ends of the thin film wire as the length in the second direction is configured to be thicker than the thickness of the portion other than the end portion of the thin film wire.

According to the invention of claim 2, in addition to the action of the invention of claim 1, the winding line is composed of a winding of a thin film wire made of a conductor, and the end portion in the thin film wire in the width direction. Since the thickness of at least one of the two is thicker than the thickness of the portion of the thin film wire other than the end portion, the AC resistance as the coil can be effectively reduced.

In order to solve the above problems, the invention according to claim 3 comprises the coil according to claim 1 or 2, wherein the winding line is parallel to the winding direction and each of them is a thin film conductor. It is composed of a plurality of parallel winding lines, and the width as the length of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is the parallel on the outer peripheral side in the winding. It is configured so that it is wider than the width of the outer peripheral winding line, which is a winding line, and the thickness of at least a part of the inner winding line as the length in the second direction is thicker than the thickness of the outer peripheral winding line. To.

According to the invention of claim 3, in addition to the action of the invention of claim 1 or 2, the winding line is composed of a plurality of parallel winding lines, and the width of the inner winding line is the outer circumference. Since it is wider than the winding line and at least a part of the inner winding line is thicker than the outer winding line, the AC resistance as a coil can be made more effective by using the parallel winding line configuration together. Can be reduced.

In order to solve the above problems, the invention according to claim 4 comprises the coil according to claim 1 or 2, wherein the winding line is parallel to the winding direction and each of them is a thin film conductor. It is composed of a plurality of parallel winding lines, and the width as the length of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is the parallel on the outer peripheral side in the winding. The width of the outer peripheral winding line, which is a winding line, is wider than the width of the outer peripheral winding line, and the thickness of the outer peripheral winding line as the length in the second direction and the thickness of the inner peripheral side end of the inner peripheral winding line are the inner circumference. It is configured to be thicker than the thickness of the outer peripheral end of the winding line.

According to the invention of claim 4, in addition to the action of the invention of claim 1 or 2, the winding line is composed of a plurality of parallel winding lines, and the width of the inner winding line is the outer circumference. The configuration of the parallel winding line is wider than the width of the winding line, and the thickness of the outer peripheral winding line and the thickness of the inner peripheral side end of the inner winding line are thicker than the thickness of the outer peripheral side end of the inner winding line. By using the above in combination, the AC resistance as a coil can be reduced more effectively.

In order to solve the above problems, the invention according to claim 5 comprises the coil according to claim 1 or 2, wherein the winding line is composed of a plurality of parallel winding lines parallel to each other in the winding direction. The cross-sectional shape of the outer peripheral winding line, which is the parallel winding line on the outer peripheral side in the winding, is a circle or an ellipse having a major axis in the first direction, and the parallel winding line on the inner peripheral side in the winding. The width of the inner winding line made of a thin film conductor as the length in the first direction is longer than the diameter when the cross-sectional shape is the circle or the major axis when the cross-sectional shape is the ellipse. The diameter when the cross-sectional shape is the circle, the short diameter when the cross-sectional shape is the ellipse, and the thickness of the inner peripheral side end of the inner peripheral winding line as the length in the second direction are described above. It is configured to be longer than the thickness of the outer peripheral end of the inner winding line.

According to the invention of claim 5, in addition to the operation of the invention of claim 1 or 2, the winding line is composed of a plurality of parallel winding lines, and the cross-sectional shape of the outer peripheral winding line is circular. Alternatively, it is an ellipse having a major axis in the first direction, and the width of the inner winding line is longer than the diameter when the cross-sectional shape of the outer peripheral winding line is a circle or the major axis when the cross-sectional shape is an ellipse. Since the diameter when is a circle or the diameter when the cross-sectional shape is elliptical and the thickness of the inner peripheral side end of the inner winding line is longer than the thickness of the outer peripheral side end of the inner winding line. By using the parallel winding line configuration together, the AC resistance as a coil can be reduced more effectively.

In order to solve the above problems, the invention according to claim 6 comprises the coil according to claim 1 or 2, wherein the winding line is parallel to the winding direction and each of them is a thin film conductor. It is composed of a plurality of parallel winding lines, and the width as the length of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is the parallel on the outer peripheral side in the winding. The width of the outer peripheral winding line, which is the winding line, is wider than the width, and the average value of the thickness of the outer peripheral winding line as the length in the second direction in the first direction is within the position of the corresponding winding direction. It is configured to be thicker than the average value of the thickness of the circumferential line in the first direction.

According to the invention of claim 6, in addition to the action of the invention of claim 1 or 2, the winding line is composed of a plurality of parallel winding lines, and the width of the inner winding line is the outer circumference. A parallel winding line because it is wider than the width of the winding line and the average value in the width direction of the thickness of the outer winding line is thicker than the average value in the width direction of the thickness of the inner winding line at the corresponding winding direction position. By using the above configurations together, the AC resistance as a coil can be reduced more effectively.

In order to solve the above problems, the invention according to claim 7 is composed of a power transmission device and a power receiving device separated from the power transmission device, and transmits power from the power transmission device to the power receiving device in a non-contact manner. The power transmission coil included in the power transmission system, which is the coil according to any one of claims 1 to 6, is a power transmission coil arranged to face the power receiving device. , An output means for outputting electric power to be transmitted to the power transmission coil.

In order to solve the above problems, the invention according to claim 8 is composed of a power transmission device and a power receiving device separated from the power transmission device, and transmits power from the power transmission device to the power receiving device in a non-contact manner. In the power receiving device included in the power transmission system, the power receiving coil which is the coil according to any one of claims 1 to 6 and which is arranged to face the power transmission device. , And an input means connected to the power receiving coil.

In order to solve the above problems, the invention according to claim 9 is a power transmission device according to claim 7 and a power receiving device that is separated from the power transmission device and is arranged so as to face the power transmission coil. A power receiving device for receiving the electric power transmitted from the power transmitting device is provided.

In order to solve the above problems, the invention according to claim 10 is the power transmission device and the power receiving device according to claim 8, which are separated from the power transmission device and the power receiving coil faces the power transmission device. It is provided with a power receiving device for receiving the electric power transmitted from the power transmitting device.

According to the invention according to any one of claims 7 to 10, at least one of the transmission coil provided in the power transmission device constituting the power transmission system and the power receiving coil provided in the power receiving device is claimed. Since it is the coil according to any one of items 1 to 6, when the transmission coil or the power receiving coil is opposed to each other to perform non-contact power transmission, alternating current due to the skin effect or proximity effect is performed. The resistance can be reduced, and both weight reduction and cost reduction, improvement of transmission efficiency, and prevention of an increase in operating temperature can be achieved at the same time. Further, since the AC resistance can be reduced without increasing the length of the winding line in the first direction, it is possible to reduce the size of the coil as a whole, particularly the plan view shape.

According to the present invention, in a winding line in which the length in the first direction is longer than the length in the second direction, the length in the second direction of the portion of the winding line having a relatively high current density is relative to the density. It is longer than the length of the lower winding line portion in the second direction.

Therefore, it is possible to reduce the AC resistance due to the so-called skin effect or proximity effect in the winding line for weight reduction and cost reduction, and it is possible to reduce the weight and cost, improve the transmission efficiency, and prevent the operating temperature from rising. And, can be compatible. Further, since the AC resistance can be reduced without increasing the length of the winding line in the first direction, it is possible to reduce the size of the coil as a whole, particularly the plan view shape.

It is a block diagram which shows the outline structure of the power transmission system of an embodiment. It is a top view which shows the structure of the power receiving coil of an embodiment. It is a figure which illustrates the distribution of the current density in the power receiving coil at the time of power transmission using the power receiving coil of an embodiment. It is sectional drawing which shows the structure of the transmission coil of embodiment, (a) is the sectional view which shows the structure of the said transmission coil, (b) is the sectional view which shows the structure of the transmission coil of 1st modification. , (C) is a cross-sectional view showing the structure of the transmission coil of the second modified form, and (d) is a cross-sectional view showing the structure of the transmission coil of the third modified form. There is a figure which shows the manufacturing method of the power transmission coil of an embodiment, (a) is the figure which illustrates the cross section of the copper strip used in the 1st example of the manufacturing method, (b) is the figure which exemplifies the 2nd example of the manufacturing method. It is a figure which illustrates the cross section of the copper-clad laminated board used. It is a figure which shows the relationship between the frequency and impedance as an effect by the structure of the power transmission coil and the power reception coil of an embodiment. It is a figure which shows the relationship between the frequency and the impedance ratio as an effect by the structure of the power transmission coil and the power reception coil of an embodiment.

Next, a mode for carrying out the present invention will be described with reference to FIGS. 1 to 5. In the embodiments and modifications described below, the electric power for charging the rechargeable battery mounted on the electric vehicle is transmitted to the electric vehicle equipped with the rechargeable battery in a non-contact manner by a magnetic field resonance method. It is an embodiment and a modification when this invention is applied to a power transmission system.

Here, the electric power transmission system by the magnetic field resonance method of the embodiment and the modified form is arranged so as to face (that is, face each other) away from the power transmission coil described later, which is to send power, and from the power transmission coil. It is provided with a power receiving coil, which will be described later, for receiving the transmitted power.

(I) Overall configuration and operation of the power transmission system of the embodiment
First, the overall configuration and operation of the power transmission system of the embodiment will be described with reference to FIG. Note that FIG. 1 is a block diagram showing an outline configuration of the power transmission system of the embodiment.

As shown in FIG. 1, the power transmission system S of the embodiment includes a power receiving device R including a power receiving unit RV and the power receiving coil RC, and a power transmission device T including a power transmission unit TR and the power transmission coil TC. Has been done. At this time, the power receiving device R is mounted on the electric vehicle and is connected to a storage battery (not shown) mounted on the electric vehicle. On the other hand, the power transmission device T is installed on the ground where the electric vehicle moves or stops. Then, when charging the storage battery, the electric vehicle is operated or stopped so that the power receiving coil RC of the power receiving device R and the power transmission coil TC of the power transmission device T face each other. When charging the storage battery by the power transmission system S of the embodiment, the power transmission device T installed on the ground below the stop position of the power receiving device R mounted on the stopped electric vehicle is used. It can be configured to transmit electric power from the power transmission device T via the power transmission coil TC. In addition, for the power receiving device R mounted on the moving electric vehicle, via the power transmission coil TC of a plurality of power transmission devices T installed in a certain distance section of the road on which the electric vehicle is moving. Therefore, it may be configured to continuously transmit electric power from the power transmission device T. At this time, the power transmission unit TR corresponds to an example of the "output means" of the present invention, and the power receiving unit RV corresponds to an example of the "input means" of the present invention.

On the other hand, as shown in FIG. 1, the power transmission coil TC is configured by stacking the power transmission loop coil TL1 and the power transmission loop coil TL2. Further, the power receiving coil RC is configured by laminating a power receiving loop coil RL2 and a power receiving loop coil RL1. Then, the electric power to be transmitted to the power receiving device R is input from the power transmission unit TR to the power transmission loop coil TL1 and the power transmission loop coil TL2 of the power transmission coil TC. As a result, the power transmission coil TC transmits the electric power to the power reception coil RC by the magnetic field resonance method. On the other hand, the power receiving loop coil RL2 and the power receiving loop coil RL1 of the power receiving coil RC are arranged so as to face the power transmission coil TC, and the power received from the power transmission coil TC by the magnetic field resonance method is output to the power receiving unit RV. At this time, the power transmission loop coil TL1 and the power transmission loop coil TL2 or the power reception loop coil RL2 and the power reception loop coil RL1 correspond to an example of the "coil" of the present invention, respectively.

In the above configuration, the power transmission unit TR of the power transmission device T outputs the above power to be transmitted to the power reception device R to the power transmission coil TC while complying with the regulations such as the Radio Law in the country where the power transmission system S is used. do. As a result, the power transmission coil TC transmits the output power to the power reception coil RC by the magnetic field resonance method. The laws and regulations that should be dealt with at this time regulate the leakage magnetic field so that it is below a predetermined level, for example, in consideration of the influence on the human body. Further, in order to be able to use the interconnection between all the power transmitting devices T and the power receiving devices R, as a result, it is necessary for both to use a frequency in a predetermined range, which is the above. The frequency or frequency band in the predetermined range must follow the recommendations of international organizations such as ISO (International Organization for Standardization) or IEC (International Electrotechnical Commission) as the above-mentioned regulations. Further, since the lower limit value of the transmission efficiency considering the predetermined positional deviation between the power transmission coil TC and the power reception coil RC is also defined by the above-mentioned international organization, the power transmission system S is also required to have high power transmission efficiency. To.

Then, the power receiving loop coil RL1 and the power receiving loop coil RL2 constituting the power receiving coil RC of the power receiving device R that has received the power from the power transmission coil TC by the magnetic field resonance method output the received power to the power receiving unit RV. As a result, the power receiving unit RV converts the output corresponding to the electric power (for example, the high frequency power of 85 kilohertz) into a DC (direct current) current by a power conversion unit (not shown) and outputs the output to the storage battery of the electric vehicle. .. With the above configuration of the power receiving device R1, the storage battery is charged with a required amount of electric power.

(II) Configuration of power transmission coil TC (power receiving coil RC)
Next, the configurations of the power transmission coil TC and the power reception coil RC of the embodiment used in the power transmission system S of the above-described embodiment will be described with reference to FIGS. 2 to 4. The power transmission coil TC and the power reception coil RC of the embodiment basically have the same configuration except for their sizes. That is, the configuration of the power receiving loop coil RL1 and the configuration of the power transmission loop coil TL1 are basically the same. Further, the configuration of the power receiving loop coil RL2 and the configuration of the power transmission loop coil TL2 are basically the same. Further, the positional relationship between the power receiving loop coil RL1 and the power receiving loop coil RL2 in the power receiving coil RC and the positional relationship between the power transmission loop coil TL1 and the power transmission loop coil TL2 in the power transmission coil TC are basically. It is the same. Therefore, in the following description, the structure of the power receiving coil RC will be described. Further, FIG. 2 is a plan view showing the structure of the power receiving coil RC of the embodiment, and FIG. 3 is a diagram illustrating the distribution of the current density in the power receiving coil at the time of power transmission using the power receiving coil. Is a cross-sectional view showing the structure of the power receiving coil and the like. At this time, FIG. 2 is a plan view of the power receiving device R when the power receiving coil RC is viewed from the power receiving unit RV side (see FIG. 1).

As shown in the plan view of FIG. 2, the power receiving coil RC of the embodiment includes a power receiving loop coil RL1 composed of two parallel parallel copper thin film wires RL11 and a copper thin film wire RL12, which will be described later, and FIG. A power receiving loop coil RL2 (not shown) is laminated with an insulating film BF (details will be described later) in the direction of the paper surface of FIG. 2 (see FIG. 1). Further, the power receiving loop coil RL2 is composed of two parallel parallel copper thin film wires RL21 and a copper thin film wire RL22, which will be described later. Further, the center of winding of the copper thin film wire RL11 and the copper thin film wire RL12 constituting the power receiving loop coil RL1 and the winding center of the copper thin film wire RL21 and the copper thin film wire RL22 constituting the power receiving loop coil RL2 are mutual. Is the same as. In the above configuration, the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22 correspond to an example of the "parallel winding line" of the present invention, respectively. In the embodiment, the film BF is used for the insulation between the power receiving loop coil RL1 and the power receiving loop coil RL2, but in addition to these, an insulating material such as a glass epoxy material can also be used. Further, in order to efficiently dissipate the heat generated as the power receiving coil RC, for example, a thin film material in which ceramic particles or the like are dispersed can be used. Further, an appropriate void holding material may be used so as to be laminated through the required voids.

As shown in FIG. 2, the power receiving loop coil RL1 of the power receiving coil RC is composed of a copper thin film wire RL11 and a copper thin film wire RL12 wound in parallel with each other in the same layer, and the outermost peripheral portion thereof. One side has an external connection terminal O1 and an external connection terminal O2 for connecting the copper thin film wire RL11 and the copper thin film wire RL12 and connecting the power receiving loop coil RL1 to the transmission unit TR. The power receiving loop coil RL1 is composed of parallel copper thin film wires RL11 and copper thin film wires RL12 wound six times (6 turns) in parallel, and both ends of each of the copper thin film wires RL11 and the copper thin film wires RL12. (In the case shown in FIG. 2, the center of the right side portion) is the external connection terminal O1 and the external connection terminal O2. Further, the width of the copper thin film wire RL11 <the width of the copper thin film wire RL12 is set over the entire circumference of the power receiving loop coil RL1. Further, the thickness of each of the copper thin film wire RL11 and the copper thin film wire RL12 is set to be uniform and the same thickness over the entire circumference of the power receiving loop coil RL1. Furthermore, the power receiving loop coil RL1 is provided with a straight line portion on each of the upper side portion, the lower side portion, the left side portion, and the right side portion in FIG. 2, and each straight line portion is connected by a substantially concentric arcuate curved portion. ing. Further, at the intersection of the copper thin film wire RL11 and the copper thin film wire RL12, the copper thin film wire RL11 and the copper thin film wire RL12 can be formed by a laminated structure sandwiching an insulating layer (see FIG. 2) or a method using a jumper wire. They are isolated from each other and intersect each other.

In addition to this, in the power receiving loop coil RL1 of the embodiment, the portion having a high current density corresponds to the distribution of the current densities in each of the copper thin film wire RL11 and the copper thin film wire RL12 at the time of power transmission using the power receiving loop coil RL1. The thickness of the copper thin film wire RL11 or the copper thin film wire RL12 is increased.

That is, in the conventional loop coil L in which the copper thin film wire L1 and the copper thin film wire L2 having a flat shape having the same width as the copper thin film wire RL11 and the copper thin film wire RL12 of the embodiment are wound, the power of the embodiment is used. The distribution of the current density when it is used for power transmission similar to the transmission system S is that of the wide copper thin film wire L2 on the inner peripheral side, as illustrated in FIG. 3 by the simulation results of the inventors of the present application. It was found that the current densities were high in the entire copper thin film wire L1 having a narrow width on the inner peripheral side edge portion and the outer peripheral side (see the dark part in FIG. 3). Therefore, in the copper thin film wire RL11 and the copper thin film wire RL12 of the embodiment, the copper thin film wire RL12 is made of the same copper material as the copper thin film wire RL12 and has a width along the inner peripheral side edge portion of the copper thin film wire RL12 having a wide width on the inner peripheral side. Copper thin film wire RL12a, which is narrower than the copper thin film wire RL12, is laminated. As a result, the thickness of the inner peripheral side edge portion increases by the thickness of the copper thin film wire RL12a, and as a result, the portion of the copper thin film wire RL12 in which the current density tends to increase (see FIG. 3). The impedance of the film is reduced to suppress the loss.

On the other hand, the power receiving loop coil RL2 of the embodiment laminated on the power receiving loop coil RL1 via the film BF includes the copper thin film wire RL21 having the same plane shape and cross-sectional shape as the copper thin film wire RL11, and the copper thin film wire RL12 and the copper thin film wire RL12. The copper thin film wire RL22 and the copper thin film wire 22a having the same plane shape and cross-sectional shape as the copper thin film wire RL12a are wound in parallel. Further, on the outermost peripheral portion of the power receiving loop coil RL2, an external connection terminal O1 and an external connection terminal O2 similar to the external connection terminal O1 and the external connection terminal O2 of the power receiving loop coil RL1 are provided. Then, the power receiving loop coil RL2 has the power receiving loop coil RL1 turned upside down in the direction along the central axis of the power receiving coil RC (that is, the power receiving loop coil RL1 is turned upside down) and the power receiving loop. It is laminated on the film BF so as to be concentric with the coil RL1. As a result, when viewed from the center of winding of each of the power receiving loop coil RL1 and the power receiving loop coil RL2, the copper thin film wire RL12 and the copper thin film wire RL12a and the copper thin film wire RL11 of the power receiving loop coil RL1 are the copper thin film of the power receiving loop coil RL2. The wires RL22, the copper thin film wire RL22a, and the copper thin film wire RL21 are laminated so as to be at the same positions. Further, the external connection terminal O1 of the power receiving loop coil RL1 and the external connection terminal O1 of the power receiving loop coil RL2, and the external connection terminal O2 of the power receiving loop coil RL1 and the external connection terminal O2 of the power receiving loop coil RL2 are separately connected to each other. It may be connected to the power receiving unit RV after being interconnected between layers via the film BF.

More specifically, as shown in FIG. 4A, the α-β cross section of the power receiving loop coil RL1 and the power receiving loop coil RL2 is a film BF. It has a cross-sectional shape that is line-symmetrical across. The outer peripheral side of the copper thin film wire RL12, the copper thin film wire RL11, the outer peripheral side of the copper thin film wire RL22, and the copper thin film wire RL21 have the same thickness. A copper thin film wire RL12a having a width narrower than that of the copper thin film wire RL12 and a copper thin film wire RL22a having a width narrower than that of the copper thin film wire RL22 are laminated on the inner peripheral side edge portion of the copper thin film wire RL22, respectively. As a result, the thickness of each of the inner peripheral side edge portion of the copper thin film wire RL12 and the inner peripheral side edge portion of the copper thin film wire RL22 increases by the thickness of each of the laminated copper thin film wire RL12a and the copper thin film wire RL22ba. Therefore, the impedance of each portion (see FIG. 3) of the copper thin film wire RL12 and the copper thin film wire RL22, which tend to have a high current density, is reduced to suppress the loss.

As for the cross-sectional structure of the power receiving loop coil RL1, a plurality of modified cross-sectional structures can be adopted.

That is, as the first modified form, as shown in FIG. 4B, the cross section corresponding to the α-β cross section in FIG. 2 is replaced with the copper thin film wire RL11 and the copper thin film wire RL21 of the embodiment, and the copper thin film wire RL12 is used. RL11a, a copper thin film wire having a thickness corresponding to the thickness of the copper thin film wire RL12a, and RL12a, a copper thin film wire having a thickness corresponding to the thickness of the copper thin film wire RL22 plus the copper thin film wire RL22a. The power receiving loop coil RL1a and the power receiving loop coil RL2a provided on the outer peripheral sides of both sides of the BF may be used.

Further, as a second modification, the cross section corresponding to the α-β cross section in FIG. 2 when applied to the power receiving loop coil RL1a and the power receiving loop coil RL2a having the cross-sectional structure shown in FIG. 4 (b) is shown in FIG. 4 (c). As shown, the outer peripheral side edges of the copper thin film wire RL12 and the copper thin film wire RL22 correspond to the thickness of the copper thin film wire RL12b and the copper thin film wire RL22a having a thickness corresponding to the thickness of the copper thin film wire RL12a. It may be a power receiving loop coil RL1b and a power receiving loop coil RL2b in which a copper thin film wire RL22b having a thickened thickness is further laminated. Further, the copper thin film wire RL12b and the copper thin film wire RL22b having the thicknesses exemplified in FIG. 4C are used, and the copper thin film wire RL12 and the copper thin film wire RL22 of the power receiving loop coil RL1 (see FIG. 4A) of the embodiment are respectively used. It may have a cross-sectional structure laminated on the outer peripheral side edge portion of the above.

Furthermore, as a third modified form, as shown in FIG. 4 (d), the cross section corresponding to the α-β cross section in FIG. 2 is replaced with the copper thin film wire RL11 and the copper thin film wire RL21 of the embodiment, and the copper thin film is used. A copper wire RLS1 having a circular cross-sectional shape having a diameter corresponding to the thickness of the wire RL12 plus the copper thin film wire RL12a, and a circular cross-sectional shape having a diameter corresponding to the thickness of the copper thin film wire RL22 plus the copper thin film wire RL22a. The power receiving loop coil RL1c and the power receiving loop coil RL2c may be provided with the copper wire RSL2 provided on both outer peripheral sides of the film BF. At this time, either one or both of the copper wire RLS1 and the copper wire RSL2 is a copper wire having an elliptical cross-sectional shape obtained by crushing the copper wire RLS1 and the copper wire RSL2 in the vertical direction in FIG. 4 (d). May be good.

(III) Manufacturing method of power receiving coil RC and power transmission coil TC
Next, the outline of the method of manufacturing the power receiving coil RC of the embodiment will be described with reference to FIG. The three manufacturing methods described below can also be adopted as a manufacturing method for the power transmission coil TC having the same configuration as the power receiving coil RC.

As a first example of the manufacturing method, a manufacturing method including each of the following steps (a) -1 to (a) -4 can be used.
(A) -1: A cross-sectional shape in which the copper thin film wire RL12a is laminated on the copper thin film wire RL12, a cross-sectional shape in which the copper thin film wire RL22a is laminated on the copper thin film wire RL22, and a cross-sectional shape in which the copper thin film wire RL22a is laminated by the "melt extruding method" using copper as a material. Copper strips M1 and copper strips M2 each having a cross-sectional shape (see FIG. 5A) corresponding to the cross-sectional shapes of the copper thin film wire RL11 and the copper thin film wire RL12 are manufactured.
(A) -2: The copper strips M1 and copper strips M2 manufactured in (a) -1 above are applied to the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22, respectively. For example, it is adhered to the positions on both sides of the corresponding film BF to form the power receiving loop coil RL1 of the embodiment.
(A) -3: The intersection (see FIG. 2) at each of the copper thin film wire RL11 and the copper thin film wire RL12 and the copper thin film wire RL21 and the copper thin film wire RL22 is formed.
(A) -4: The external connection terminal O1 and the external connection terminal O2 are connected to the power receiving unit RV (in the case of the power receiving device R) or the power transmission unit TR (in the case of the power transmission device T).

At this time, in the case of manufacturing the power receiving loop coil RL1c and the power receiving loop coil RL2c of the third modified form exemplified in FIG. 4D, the copper wire as the copper material corresponding to the copper wire RLS1 and the copper wire RSL2 is used as the copper. For example, it may be adhered to the position of the film BF corresponding to the wire RLS1 and the copper wire RSL2. Further, when the copper wire RLS1 and the copper wire RSL2 having an elliptical cross-sectional shape are manufactured, the copper material crushed so as to have the corresponding cross-sectional shape may be used.

Further, when the first example of the manufacturing method is used, the copper strip M1 is particularly bent in a state where the copper thin film wire RL12a and the copper thin film wire RL22a are laminated for the curved portion in each of the power receiving loop coil RL1 and the power receiving loop coil RL2. May be difficult. In this case, the copper thin film wire RL12a and the copper thin film wire RL22a may be laminated only on the linear portion of each of the power receiving loop coil RL1 and the power receiving loop coil RL2.

On the other hand, as a second example of the manufacturing method, a manufacturing method including each of the following steps (b) -1 to (b) -7 can be used.
(B) -1: A copper thin film is formed on both sides of the film BF.
(B) -2: A resist is applied to the surfaces of the copper thin films (both sides) formed in (b) -1 above.
(B) -3: The resist applied in (b) -2 is patterned on each surface into the shapes of the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22, respectively.
(B) -4: After the patterning of (b) -3, the etching process is performed to form the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22 (note that the intersection shown in FIG. 2). In the portion to be interconnected between layers, the above (b) -2 to the above (b) -4 are repeated for each layer).
(B) -5: A portion of the copper thin film wire RL12 other than the copper thin film wire RL12 on which the copper thin film wire RL12a is laminated, and a portion of the copper thin film wire RL22 other than the copper thin film wire RL22 on which the copper thin film wire RL22a is laminated. Apply the resist again.
(B) -6: The surfaces of the film BF coated with the resist in (b) -5 above are selectively electroplated to form the copper thin film wire RL12a and the copper thin film wire RL22a, and the power receiving loop is formed. The power receiving coil RC including the coil RL1 and the power receiving loop coil RL2.
(B) -7: The external connection terminal O1 and the external connection terminal O2 are connected to the power receiving unit RV (in the case of the power receiving device R) or the power transmission unit TR (in the case of the power transmission device T).

In the case of the second example of the manufacturing method described above, although the number of steps itself is large, it is possible to efficiently increase the film thickness of the necessary portion (that is, the portion where the copper thin film wire RL12a and the copper thin film wire RL22a are laminated). It will be possible.

Finally, as a third example of the manufacturing method, a general printed circuit board manufacturing process, that is, a manufacturing method including each of the following steps (c) -1 to (c) -6 can be used. At this time, as the material used in the manufacturing process, for example, a copper-clad laminate 100 in which copper C is preliminarily laminated on both surfaces of the glass epoxy substrate EP, as illustrated in FIG. 5B, can be used. In the following description, the copper-clad laminate 100 is simply referred to as "CCL (Copper Clad Laminate)" 100.
(C) -1: A resist is applied to the surfaces of copper C on both sides of the CCL100.
(C) -2: The resist applied in (c) -1 above is patterned on each surface into the shapes of the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22, respectively.
(C) -3: After the patterning of (c) -2 above, etching treatment is performed to form the copper thin film wire RL11 and the copper thin film wire RL12, and the copper thin film wire RL21 and the copper thin film wire RL22.
(C) -4: Copper strip C1 to be the copper thin film wire RL12a is welded, for example, to the position of the copper thin film wire RL12 on which the copper thin film wire RL12a is laminated. Further, for example, the copper strip C2 to be the copper thin film wire RL22a is welded to the position of the copper thin film wire RL22 on which the copper thin film wire RL22a is laminated. As a result, the copper thin film wire RL12a and the copper thin film wire RL22a are formed to form a power receiving coil RC including a power receiving loop coil RL1 and a power receiving loop coil RL2.
(C) -5: The external connection terminal O1 and the external connection terminal O2 are connected to the power receiving unit RV (in the case of the power receiving device R) or the power transmission unit TR (in the case of the power transmission device T).

Next, the frequency in the power transmission of the power transmission system S using the power receiving coil RC or the power transmission coil TC of the embodiment based on the configuration shown in FIGS. 2 and 4A is changed to various values to obtain impedance and the like. The experimental results (simulation results) obtained by measuring the above will be described with reference to FIGS. 6 and 7 in comparison with the impedance and the like in the power transmission using the power receiving coil and the transmitting coil of the conventional example. Note that FIG. 6 is a diagram showing the relationship between frequency and impedance as an effect due to the structure of the power receiving coil RC and the power transmitting coil TC of the embodiment, and FIG. 7 is a diagram showing the frequency and impedance ratio (AC / DC) as the effect. It is a figure which shows the relationship of.

At this time, the impedance ratio shown on the vertical axis of FIG. 7 is the impedance at each frequency shown on the horizontal axis of FIG. 7 at 1 kHz, which is a frequency corresponding to direct current in power transmission using the power transmission system S. It is the value divided. Here, the impedance at 1 kHz is generally proportional to the cross-sectional area of the copper thin film wire constituting the power receiving loop coil or the power transmission loop coil, so that the impedance corresponds to the weight of the power receiving coil or the power transmission coil ( It can be said that it is a proportional parameter. Therefore, by examining the relationship with the frequency with the vertical axis of FIG. 7 as the impedance ratio, it is possible to determine which of the power receiving loop coil and the power transmission loop coil can suppress the impedance with less material at each frequency. It can be judged objectively.

Further, the power receiving coil RC and the power transmission coil TC of the embodiment, the power receiving coil and the power transmission coil of the first modified form (see FIG. 4A), whose measurement results of impedance and the like are shown in FIGS. The structural specifications of each of the power receiving coil and the power transmitting coil of the above-mentioned conventional example are as follows.

(I) Structural specifications of the power receiving coil RC (power transmission coil TC) of the embodiment
-Overall shape: length 280 mm x width 280 mm-Thickness of copper thin film wire RL12a + thickness of copper thin film wire RL12: 0.5 mm-Thickness of copper thin film wire RL22a + thickness of copper thin film wire RL22: 0 .5 mm-thickness of copper thin film wire RL12 only and thickness of copper thin film wire RL11, and thickness of copper thin film wire RL22 only and thickness of copper thin film wire RL21: 0.2 mm-width of copper thin film wire RL12 And the width of the copper thin film wire RL22: 6.5 mm ・ The width of the copper thin film wire RL11 and the width of the copper thin film wire RL21: 2.0 mm ・ The thickness of the film BF: 0.2 mm ・ Plane shape: see FIG.

(II) Structural specifications of the power receiving coil (power transmission coil) of the first modified form
-Overall shape: length 280 mm x width 280 mm-Thickness of copper thin film wire RL12a + thickness of copper thin film wire RL12: 0.5 mm-Thickness of copper thin film wire RL22a + thickness of copper thin film wire RL22: 0 .5 mm-Thickness of copper thin film wire RL12 only and thickness of copper thin film wire RL22 only: 0.2 mm-Thickness of copper thin film wire RL11a and thickness of copper thin film wire RL21a: 0.5 mm-Copper thin film Width of wire RL12 and width of copper thin film wire RL22: 6.5 mm ・ Width of copper thin film wire RL11a and width of copper thin film wire RL21a: 2.0 mm ・ Thickness of film BF: 0.2 mm ・ Plane shape: See Figure 2.

(III) Structural specifications of the conventional power receiving coil (power transmission coil)
-Overall shape: length 280 mm x width 280 mm-Thickness of copper thin film wire on the inner circumference side (uniform): 0.5 mm-Thickness of copper thin film wire on the outer circumference side (uniform): 0.5 mm-Inner circumference side Width of copper thin film wire: 6.5 mm ・ Width of outer peripheral side copper thin film wire: 2.0 mm ・ Thickness of interlayer insulating layer: 0.2 mm ・ Plane shape: Uniform thickness of inner peripheral side copper thin film wire and The copper thin film wire on the outer peripheral side rotates five times in parallel (5 turns)

At this time, the cross-sectional area of the inner peripheral side copper thin film wire in the conventional power receiving coil (transmission coil) is, for example, the combination of the copper thin film wire RL12a and the copper thin film wire RL12 in the power receiving coil RC (transmission coil TC) of the embodiment. It is wider than the cross-sectional area and wider than the combined cross-sectional area of the copper thin film wire RL22a and the copper thin film wire RL22. Further, the cross-sectional area of the outer peripheral side copper thin film wire in the conventional power receiving coil (transmission coil) is wider than the cross-sectional area of the copper thin film wire RL11 in the power receiving coil RC (transmission coil TC) of the embodiment, and the copper thin film wire is further formed. It is wider than the cross-sectional area of RL21.

Then, as shown in FIG. 6, looking at the relationship between the frequency and the simple impedance, the impedance in the power receiving coil RC (transmission coil TC) of the embodiment and the impedance in the power receiving coil (transmission coil) of the first modified form are Both of them exceed the impedance of the conventional power receiving coil (transmission coil). This is because the cross-sectional area of the copper thin film wire constituting the power receiving coil (power transmission coil) of the conventional example is larger than the cross-sectional area of the copper thin film wire RL12 or the like (see FIGS. 4 (a) and 4 (b)). It is thought to be caused. On the other hand, as shown in FIG. 7, looking at the relationship between the frequency and the impedance ratio, the impedance ratio in the power receiving coil RC (transmission coil TC) of the embodiment and the impedance in the power receiving coil (transmission coil) of the first modified form. Both ratios are lower than the impedance ratio of the conventional power receiving coil (transmission coil). Based on the above results, the power receiving coil RC (power transmission coil TC) of the embodiment and the power receiving coil (power transmission coil) of the first modified form are more than the power receiving coil (power transmission coil) of the conventional example at each frequency. It can be seen that the impedance can be suppressed with a small amount of material.

As described above, according to the structure of the power receiving coil RC and the power transmitting coil TC of the embodiment, the thickness of the portion of the power receiving loop coil RL1 and the power receiving loop coil RL2 in which the current density at the time of power transmission is relatively high is increased. Since the density is thicker than the thickness of the relatively low portion (see FIGS. 2 to 4 (a)), the so-called skin effect in the power receiving loop coil RL1 and the power receiving loop coil RL2 for weight reduction and cost reduction. Alternatively, the impedance due to the proximity effect can be reduced, and both weight reduction and cost reduction, improvement of transmission efficiency, and prevention of an increase in operating temperature can be achieved at the same time. Further, since the impedance can be lowered without increasing the width of the copper thin film wire RL11 or the like, it is possible to reduce the size of the entire power receiving coil RC and the entire power transmission coil TC, especially in a plan view.

Further, since the thickness of the portion of the copper thin film wire RL12a and the thickness of the portion of the copper thin film wire RL22a are thicker than the thickness of the other portions (see FIG. 4A), the power receiving loop coil RL1 and the power receiving loop coil RL2 are used. Impedance can be effectively reduced.

Further, according to the structure of the power receiving coil or the transmitting coil of the first modified form, the thickness of the portion of the copper thin film wire RL12a, the thickness of the portion of the copper thin film wire RL22a, the thickness of the copper thin film wire RL11a and the copper thin film wire RL21a. Since the thickness of is thicker than the other parts (see FIG. 4B), the impedance as the power receiving coil or the power transmitting coil is more effective even in the case of the structure of the power receiving coil or the power transmitting coil of the first modified form. Can be reduced.

Furthermore, according to the structure of the power receiving coil or the transmitting coil of the second modified form, the thickness of the portion of the copper thin film wire RL12a and the thickness of the portion of the copper thin film wire RL22a, the thickness of the portion of the copper thin film wire RL12b and copper. Since the thickness of the thin film wire RL22b, the thickness of the copper thin film wire RL11a, and the thickness of the copper thin film wire RL21a are thicker than the other parts (see FIG. 4C), the power receiving coil of the second modified form is used. Alternatively, even in the case of the structure of the transmission coil, the impedance as the power receiving coil or the transmission coil can be reduced more effectively.

Further, according to the structure of the power receiving coil or the transmitting coil of the third modified form, the thickness of the portion of the copper thin film wire RL12a and the thickness of the portion of the copper thin film wire RL22a are thicker than those of the other portions, and the copper wire RLS1 and Since the diameter of the copper wire RSL2 is longer than the thickness of the other portion (see FIG. 4D), even in the case of the structure of the power receiving coil or the power transmitting coil of the third modified form, the impedance as the power receiving coil or the power transmitting coil can be obtained. It can be reduced more effectively. This point is the same when the cross-sectional shape of the copper wire RLS1 or the copper wire RSL2 is elliptical.

More generally, when the power receiving loop coil or the power transmitting loop coil is configured by copper thin film wires wound in parallel instead of the structure of the power receiving coil RC or the power transmitting coil TC of the above-described embodiment. The average value of the thickness of the copper thin film wire on the outer peripheral side in the copper thin film wire on the outer peripheral side is larger than the average value of the thickness of the copper thin film wire on the inner peripheral side in the copper thin film wire on the inner peripheral side. It may be configured to be thick. At this time, the above-mentioned first modified form to the third modified form are included in this configuration. Even in this case, the impedance as the power receiving coil or the power transmitting coil can be reduced more effectively.

[Transformation]
Next, another modified form of the present invention will be described. The configurations of the power transmission system of the above-described embodiment and each modification may be modified as shown in the following (A) to (D). In the present invention, even if each of the modifications is added, the same effect as that of the power transmission system S can be obtained.

(A) Fourth modified form
First, as a fourth modification, the copper thin film wire RL11 and the copper thin film wire RL12 constituting, for example, the power receiving loop coil RL1 of the embodiment may be formed in different layers in the power receiving coil RC.

(B) Fifth modified form
Next, as the fifth modification, the order of the power receiving loop coil RL1 and the power receiving loop coil RL2 as seen from the power receiving unit RV side of the embodiment may be changed.

(C) Sixth modified form
Next, as the sixth modification, in the power receiving loop coil RL1 of the embodiment, for example, the widths of the copper thin film wire RL11 and the copper thin film wire RL12 constituting the same are set to be the same over the entire circumference thereof. The width of the copper thin film wire RL11 and the copper thin film wire RL12 may be widened from the outer periphery to the inner circumference thereof. In this case, the width obtained by adding the widths of the two parallel copper thin film wires also becomes wider toward the inner peripheral side of the power receiving coil RC.

(D) Seventh variant
Next, as the seventh modification, in the power receiving loop coil RL1 of the embodiment, the winding direction (counterclockwise direction) of the copper thin film wire RL11 and the copper thin film wire RL12 is the same over the entire circumference, but other than this. In addition, it may be configured so that it is folded back at the innermost peripheral portion and is in the opposite winding direction (clockwise direction).

(E) Eighth variant
Next, as an eighth modification, regarding the connection mode between the external connection terminal O1 and the external connection terminal O2 and the power receiving coil RC in the above embodiment, the configuration of the embodiment, that is, both ends of the power receiving loop coil RL1 and the like are the same. In addition to the configuration in which the outermost peripheral portion is connected to the external connection terminal O1 and the external connection terminal O2, respectively, the winding of the power receiving loop coil RL1 or the like is performed in one direction from the outermost peripheral portion to the innermost peripheral portion (for example, counterclockwise). It is wound in a clockwise direction), and the end portion on the outermost peripheral portion is connected to, for example, the external connection terminal O1, and the outermost circumference is formed by a laminated structure (see FIG. 2) sandwiching an insulating layer from the innermost peripheral portion or a jumper wire or the like. The end of the winding line drawn out to the portion may be configured to be connected to, for example, the external connection terminal O2.

(F) Ninth modified form
Finally, as a ninth modification, the case where the power transmission coil TC and the power receiving coil RC have the same structure in the power transmission system S has been described, but in addition to this, the power transmission coil or the power receiving coil constituting the power transmission system has been described. Only one of the above may have the same structure as the power transmission coil TC or the power reception coil RC of the embodiment.

As described above, the present invention can be used in the field of non-contact power transmission, and is particularly remarkable when applied in the field of power transmission for charging a storage battery mounted on an electric vehicle. The effect is obtained.

100 Copper-clad laminate S Power transmission system RV Power receiving unit RC Power receiving coil R Power receiving device TR Transmission unit TC Transmission coil T Transmission device BF film L Loop coil TL1, TL2 Transmission loop coil RL1, RL1a, RL1b, RL1c, RL2, RL2a RL2b, RL2c Power receiving loop coil RL11, RL11a, RL12, RL12a, RL21, RL21a, RL22, RL22a, L1, L2 Copper thin film wire RLS1, RLS2 Copper wire O1, O2 External connection terminal M1, M2, C1, C2 Copper strip EP Epoxy substrate C copper

Claims (10)

In coils used for non-contact power transmission
The coil is provided with a winding line whose length in the first direction perpendicular to the winding direction of the coil and in the direction in the winding surface of the coil is longer than the length in the second direction perpendicular to the winding surface.
The length of the portion of the winding line in which the density of the current flowing through the winding line during power transmission is relatively high in the second direction is the length of the portion of the winding line in which the density is relatively low. A coil characterized by being longer than the length in the direction. In the coil according to claim 1,
The winding line is composed of winding of a thin film wire made of a conductor.
The thickness of at least one of the widthwise ends of the thin film line as the first direction as the length of the second direction is thicker than the thickness of the portion other than the end of the thin film line. Characterized coil. In the coil according to claim 1 or 2.
The winding line is composed of a plurality of parallel winding lines parallel to the winding direction and each of which is a thin film conductor.
The width of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is larger than the width of the outer peripheral winding line, which is the parallel winding line on the outer peripheral side in the winding. Wide,
A coil characterized in that the thickness of at least a part of the inner winding line as a length in the second direction is thicker than the thickness of the outer peripheral winding line. In the coil according to claim 1 or 2.
The winding line is composed of a plurality of parallel winding lines parallel to the winding direction and each of which is a thin film conductor.
The width of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is larger than the width of the outer peripheral winding line, which is the parallel winding line on the outer peripheral side in the winding. Wide,
The thickness of the outer peripheral winding line as the length in the second direction and the thickness of the inner peripheral side end portion of the inner peripheral winding line are thicker than the thickness of the outer peripheral side end portion of the inner peripheral winding line. A coil characterized by that. In the coil according to claim 1 or 2.
The winding line is composed of a plurality of parallel winding lines parallel to each other in the winding direction.
The cross-sectional shape of the outer peripheral winding line, which is the parallel winding line on the outer peripheral side in winding, is a circle or an ellipse having a major axis in the first direction.
The width as the length in the first direction of the parallel winding line on the inner peripheral side in the winding and the inner peripheral winding line made of a thin film conductor is the diameter when the cross-sectional shape is the circle or the cross section. Longer than the major axis when the shape is the ellipse,
The diameter when the cross-sectional shape is the circle, the short diameter when the cross-sectional shape is the ellipse, and the thickness of the inner peripheral side end of the inner winding line as the length in the second direction. A coil characterized by being longer than the thickness of the outer peripheral end of the inner winding line. In the coil according to claim 1 or 2.
The winding line is composed of a plurality of parallel winding lines parallel to the winding direction and each of which is a thin film conductor.
The width of the inner peripheral winding line, which is the parallel winding line on the inner peripheral side in the winding, as the length in the first direction is larger than the width of the outer peripheral winding line, which is the parallel winding line on the outer peripheral side in the winding. Wide,
The average value of the thickness of the outer peripheral winding line as the length in the second direction in the first direction is the thickness of the inner winding line at the corresponding winding direction position in the first direction. A coil characterized by being thicker than the average value. In the power transmission device included in the power transmission system, which is composed of a power transmission device and a power reception device separated from the power transmission device, and transmits power from the power transmission device to the power reception device in a non-contact manner.
The power transmission coil according to any one of claims 1 to 6, wherein the power transmission coil is arranged so as to face the power receiving device.
An output means that outputs the power to be transmitted to the power transmission coil,
A power transmission device characterized by being equipped with. In the power receiving device included in the power transmission system, which is composed of a power transmitting device and a power receiving device separated from the power transmitting device, and transmits power from the power transmitting device to the power receiving device in a non-contact manner.
A power receiving coil which is the coil according to any one of claims 1 to 6 and which is arranged so as to face the power transmission device.
The input means connected to the power receiving coil and
A power receiving device characterized by being provided with. The power transmission device according to claim 7 and
A power receiving device that is separated from the power transmission device and is arranged so as to face the power transmission coil and that receives power transmitted from the power transmission device.
A non-contact power transmission system characterized by being equipped with. Power transmission equipment and
2.
A non-contact power transmission system characterized by being equipped with.

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