WO2025037412A1 - Coil unit, contactless power supply system, and coil structure - Google Patents

Abstract

The purpose of the present invention is to provide a coil unit, a contactless power supply system, and a coil structure capable of increasing the degree of freedom for disposing a magnetic core while maintaining the strength of magnetic coupling during power supply between a power transmission coil and a power reception coil.　This coil unit (100) has a power transmission coil (21) and a power reception coil (31). A magnetic core (50) that strengthens magnetic coupling between the power transmission coil (21) and the power reception coil (31) during power supply includes: a connection part (53) that faces a portion of the power transmission coil (21) in a z-axis direction; a penetration part (51) that penetrates the inside of the power transmission coil (21); and a crossing part (52) that sandwiches a portion of the power transmission coil (21) with the penetration part (51). During power supply, the penetration part (51) penetrates the power transmission coil (21) and the power reception coil (31), and the crossing part (52) crosses the power transmission coil (21) and the power reception coil (31).

Description

Coil unit, non-contact power supply system and coil structure

This disclosure relates to a coil unit, a non-contact power supply system, and a coil structure.

A non-contact power supply system is a system that transmits power from the power transmitting side to the power receiving side using non-contact power supply technology. Non-contact power supply technology is a technology that transmits power between two coils arranged at a distance from each other. One of these technologies transmits power using the magnetic coupling that occurs between a power transmitting coil and a power receiving coil. In such a power transmission method, the strength of the magnetic coupling between the power transmitting coil and the power receiving coil is an important value. For example, the power supply efficiency can be increased by strengthening the magnetic coupling. In order to strengthen the magnetic coupling, a structure is generally adopted in which a magnetic body that serves as a magnetic core is placed near the coil to promote the generation of a magnetic field. However, using a large amount of magnetic body increases the weight and makes the device difficult to handle. It also causes an increase in costs. For this reason, in non-contact power supply technology, the structure and arrangement method of the magnetic core are very important, and various structures have been proposed. For example, in the charging connector disclosed in Patent Document 1, the primary core (core of the power supply connector) that constitutes the power supply connector together with the primary coil, and the secondary core (core of the vehicle connector) that constitutes the vehicle connector together with the secondary coil, occupy different areas from each other.

Japanese Patent Application Publication No. 10-075538

However, the technology disclosed in Patent Document 1 employs a structure in which the coil and core fit together. Therefore, if there is a change in the coil structure, such as the shape or size of the coil, the shape and arrangement of the core must also be changed accordingly. When it is necessary to match the shapes of the core and coil in this way, there is a problem in that there is no flexibility (freedom) in the design.

The present disclosure has been made to solve the problems described above, and aims to provide a coil unit, a non-contact power supply system, and a coil structure that can increase the freedom of arrangement of the magnetic core while maintaining the strength of the magnetic coupling between the power transmission coil and the power receiving coil when power is being supplied.

The coil unit disclosed herein has a power transmission coil and a power receiving coil that have parallel winding axes and are separated by a distance in the winding axis direction, which is the direction of the winding axis; during power supply, the power transmission coil and the power receiving coil are magnetically coupled to transmit AC power from the power transmission coil to the power receiving coil; and during power supply, the coil unit is equipped with a magnetic body that strengthens the magnetic coupling between the power transmission coil and the power receiving coil. When one of the power transmission coil and the power receiving coil is designated as the first coil and the other is designated as the second coil, the magnetic body includes a connection portion that faces a part of the one coil in the winding axis direction, a through portion that protrudes from the connection portion in the winding axis direction and penetrates the inside of the one coil, and an intersection portion that protrudes from the connection portion in the winding axis direction and has a part sandwiched between the through portion and the connection portion; during power supply, the through portion penetrates the one coil and the other coil, and the intersection portion intersects the one coil and the other coil.

The coil structure of the present disclosure is a coil structure provided with a magnetic body and having a coil used for contactless power supply, the magnetic body including a connection portion facing a part of the coil in the winding axis direction, which is the direction of the winding axis of the coil, a through portion protruding from the connection portion in the winding axis direction and penetrating the inside of the coil, and an intersection portion protruding from the connection portion in the winding axis direction and sandwiching a part between the through portion and the coil, the coil is a power transmitting coil that transmits power between the other coil via magnetic energy and a power receiving coil to which power is transmitted, and is magnetically coupled to another coil separated from the other coil in the winding axis direction during power supply, and the magnetic body is a magnetic body that strengthens the magnetic coupling between the coil and the other coil during power supply, the through portion penetrates the inside of the coil and the other coil during power supply, and the intersection portion intersects one coil and the other coil.

The coil unit, non-contact power supply system, or coil structure disclosed herein can increase the freedom of arrangement of the magnetic core while maintaining the strength of the magnetic coupling between the power transmission coil and the power receiving coil during power supply.

1 is a configuration diagram showing a contactless power supply system according to a first embodiment. 2 is a diagram illustrating an example of the configuration of a power transmitting resonant circuit and a power receiving resonant circuit according to the first embodiment; 1 is a diagram illustrating a configuration example of a power receiving circuit according to a first embodiment; 1 is a perspective view showing a configuration example of a coil unit in accordance with a first embodiment; 2 is a side view showing a configuration example of the coil unit in the first embodiment. FIG. 2 is a plan view showing a configuration example of a coil unit in the first embodiment. FIG. 1A to 1C are diagrams illustrating an application example of the coil unit in the first embodiment. 10A to 10C are diagrams illustrating the arrangement of coils in an application example of the coil unit in embodiment 1. FIG. 11 is a perspective view showing a configuration example of a coil unit in a second embodiment. 13 is a side view showing a configuration example of a coil unit in embodiment 2. FIG. 13 is a side view showing an example of the configuration of a coil unit in a case where the second magnetic core has an inverted U-shaped cross section in embodiment 2. FIG. 13 is a plan view showing a configuration example of a coil unit in embodiment 2. FIG. FIG. 11 is a perspective view showing a configuration example of a coil unit in embodiment 3. FIG. 13 is a side view showing a configuration example of a coil unit in embodiment 3. 13 is a side view showing a configuration example of a coil unit in embodiment 3, in which magnetic cores are arranged on corresponding straight portions of a power transmitting coil and a power receiving coil. FIG. 16 is a diagram illustrating the magnetic core shown in FIG. 15 and the other magnetic core. FIG. FIG. 13 is a perspective view showing a configuration example of a coil unit in embodiment 4. FIG. 13 is a side view showing a configuration example of a coil unit in embodiment 4. 11 is a perspective view showing an example in which a magnetic core and a second magnetic core are arranged at corners of a power transmitting coil and a power receiving coil, respectively. FIG. 11 is a perspective view showing an example in which magnetic units are arranged on a hexagonal power transmitting coil and a hexagonal power receiving coil. FIG.

Embodiment 1.
A first embodiment will be described with reference to Figs. 1 to 8. Fig. 1 is a configuration diagram showing a contactless power supply system in the first embodiment. The contactless power supply system 1000 includes a power transmitting side device 1100 having an AC power source 10 and a power transmitting resonant circuit 20, and a power receiving side device 1200 having a power receiving resonant circuit 30 and a power receiving circuit 40. The AC power source 10 supplies AC power to the power transmitting resonant circuit 20. The AC power supplied from the AC power source 10 is converted into magnetic energy in the power transmitting resonant circuit 20. The magnetic energy generated in the power transmitting resonant circuit 20 is transmitted to the power receiving resonant circuit 30, and converted into AC power in the power receiving resonant circuit 30. This AC power is sent to the power receiving circuit 40. The AC power sent from the power receiving resonant circuit 30 to the power receiving circuit 40 is used in the power receiving circuit 40.

The AC power supply 10 is a power supply that outputs a high-frequency voltage or high-frequency current. The AC power supply 10 is not limited to being composed of only an AC current source or an AC voltage source, but may be composed of a combination of these with a power converter such as an inverter or a DC/DC converter. The AC voltage output by the AC power supply 10 may include a single frequency, or may include multiple frequency components. In addition, the output waveform of the AC power supply 10 may be a sine waveform or a triangular waveform, or may be a waveform such as a rectangular waveform.

The power transmission resonant circuit 20 and the power receiving resonant circuit 30 will be described. FIG. 2 is a diagram showing an example of the configuration of the power transmission resonant circuit and the power receiving resonant circuit according to the first embodiment. The power transmission resonant circuit 20 includes a power transmission coil 21 and at least one power transmission side resonant capacitor 22. The power transmission resonant circuit 20 may also include a resonant coil and a resonant capacitor other than the power transmission coil 21 and the power transmission side resonant capacitor 22. The power transmission resonant circuit 20 is designed so that its resonant frequency is the output frequency of the AC power source 10 or in the vicinity thereof. When the output waveform of the AC power source 10 is a rectangular waveform or the like and includes harmonic components, the power transmission resonant circuit 20 is generally designed to satisfy the resonant condition in the fundamental wave component of the output waveform, that is, the resonant frequency of the power transmission resonant circuit 20 is the frequency of the fundamental wave component. However, the power transmission resonant circuit 20 may also be designed to satisfy the resonant condition in the harmonic components of the output waveform. Note that the power transmission resonant circuit 20 shown in FIG. 2 shows one of various resonant circuit configurations, and does not limit the configuration of the power transmission resonant circuit 20.

The power receiving resonant circuit 30 includes a power receiving coil 31 and at least one power receiving side resonant capacitor 32. The power receiving resonant circuit 30 may include a resonant coil and a resonant capacitor other than the power receiving coil 31 and the power receiving side resonant capacitor 32. The power receiving resonant circuit 30 is designed so that its resonant frequency is the output frequency of the AC power source 10 or in the vicinity thereof. When the output waveform of the AC power source 10 is a rectangular wave shape or the like and includes harmonic components, the power receiving resonant circuit 30 is generally designed so that the resonant condition is satisfied in the fundamental wave component of the output waveform, that is, the resonant frequency of the power receiving resonant circuit 30 is the frequency of the fundamental wave component. However, the power receiving resonant circuit 30 may be designed so that the resonant condition is satisfied in the harmonic components of the output waveform. The power receiving resonant circuit 30 shown in FIG. 2 is configured so that one power receiving side resonant capacitor 32 is connected in series to the power receiving coil 31, but this shows one of various resonant circuit configurations and does not limit the configuration of the power receiving resonant circuit 30.

The power transmission coil 21 and the power receiving coil 31 are strongly magnetically coupled when the power transmission resonant circuit 20 and the power receiving resonant circuit 30 are in a resonant state. With the power transmission coil 21 and the power receiving coil 31 in a strongly magnetically coupled state, AC power is transmitted from the power transmission coil 21 to the power receiving coil 31. In this way, the power transmission coil 21 and the power receiving coil 31 function as a coil unit, which is a non-contact power supply coil. The configuration of the power transmission coil 21 and the power receiving coil 31 as a coil unit will be described later.

The power receiving circuit 40 will be described. FIG. 3 is a diagram showing an example of the configuration of the power receiving circuit according to the first embodiment. The power receiving circuit 40 includes a rectifier circuit 41, a filter 42, and a load 43. The power receiving circuit 40 converts the AC power supplied from the power receiving resonant circuit 30 into DC power for use. The rectifier circuit 41 is a full-bridge diode rectifier circuit composed of diodes 41a to 41d, and rectifies the AC power supplied from the power receiving resonant circuit 30. The filter 42 attenuates the high-frequency AC component contained in the output of the rectifier circuit 41. The load 43 includes an electrical device that consumes the DC power converted by the rectifier circuit 41 and the filter 42, or a battery that stores the power. The load 43 may include a power conversion circuit such as a voltage stabilization circuit. Note that the configuration of the power receiving circuit 40 shown in FIG. 3 is an example, and some elements may be omitted. For example, the rectifier circuit 41 may be omitted and the AC power may be consumed as is. Also, the filter 42 may be omitted and DC power containing high-frequency AC components may be consumed by the load 43. The circuit configuration of the rectifier circuit 41 or the filter 42 may be different. In addition, various modified examples having the same functions as the above-mentioned power receiving circuit 40 may be used.

Figure 4 is a perspective view showing an example of the configuration of a coil unit in embodiment 1. Note that Figure 4 shows a non-powered state in which the power transmission coil 21 and the power receiving coil 31 are separated by a certain distance or more. The coil unit 100 includes the power transmission coil 21, the power receiving coil 31, and a magnetic core 50, i.e., a magnetic body. Each of the power transmission coil 21 and the power receiving coil 31 is a rectangular coil wound around a virtual winding axis along a virtual plane perpendicular to the winding axis. The winding axis of the power transmission coil 21 and the winding axis of the power receiving coil 31 are parallel. The power transmission coil 21 has straight portions 21a and 21c that are parallel to each other, and straight portions 21b and 21d that are parallel to each other. The straight portions 21a and 21c are perpendicular to the straight portions 21b and 21d. The power receiving coil 31 has linear portions 31a and 31c that are parallel to each other, and linear portions 31b and 31d that are parallel to each other. The linear portions 31a and 31c are perpendicular to the linear portions 31b and 31d.

For the following explanation, the coordinate axes are set as follows. First, as shown in FIG. 4, the direction in which one side of the rectangularly wound power transmission coil 21 and power receiving coil 31 extends (the direction in which straight line portions 21b, 21d, 31b, and 31d extend), is the x-axis direction, and the direction in which the side perpendicular to the one side extends (the direction in which straight line portions 21a, 21c, 31a, and 31c extend) is the y-axis direction. The direction parallel to the winding axis of the power transmission coil 21 and power receiving coil 31 is the z-axis direction. In this case, the xy plane stretched by the x-axis and y-axis corresponds to the above-mentioned imaginary plane, so the x-axis and y-axis directions are perpendicular to the z-axis direction. For the sake of convenience, the upward direction in the figure is the +z direction, and the downward direction in the figure is the -z direction. One direction in the x-axis direction is the +x direction, and the direction opposite to the +x direction is the -x direction. Additionally, one direction along the y-axis is designated as the +y direction, and the direction opposite the +y direction is designated as the -y direction.

In FIG. 4, the power transmission coil 21 and the power receiving coil 31 are separated by a separation distance L in the direction of their respective winding axes (z-axis direction). The separation distance L is the distance between the top surface of the power transmission coil 21 and the bottom surface of the power receiving coil 31.

The magnetic core 50 is made of a magnetic material and strengthens the magnetic coupling between the power transmission coil 21 and the power receiving coil 31 during power supply. The magnetic core 50 is arranged to cover a part of the power transmission coil 21, more specifically, a part of the lower side of the straight portion 21a. The magnetic core 50 includes a through portion 51 that protrudes in the +z direction and penetrates the inside of the power transmission coil 21, an intersection portion 52 that faces the through portion 51 and intersects with the power transmission coil 21 on the outside of the power transmission coil 21, and a connection portion 53 that extends along the x-axis direction and the y-axis direction and connects the through portion 51 and the intersection portion 52. The connection portion 53 faces one surface of the part of the straight portion of the power transmission coil 21. In the example shown in FIG. 4, the connection portion 53 faces a part of the lower surface (the surface in the -z direction) of the straight portion 21a. In addition, since each straight portion of the power transmission coil 21 extends in the x-axis direction or the y-axis direction, the connection portion 53 extends parallel to each straight portion of the power transmission coil 21. In FIG. 4, the magnetic core 50 is disposed near the straight portion 21a (for example, at a position within a range of 50% or less of the separation distance L from the straight portion 21a). The width direction of the straight portion 21a is the x-axis direction, and the length direction is the y-axis direction. The x-axis direction of the connection portion 53 is also the width direction, and the y-axis direction is the length direction. In other words, the y-axis direction is the magnetic body extension direction. In addition, the x-axis direction is the opposing direction of the through portion 51 and the intersection portion 52.

In the non-powered state, the through-hole 51 of the magnetic core 50 penetrates only the inside of the power transmission coil 21 in the z-axis direction. The intersection 52 intersects only with the power transmission coil 21 (straight portion 21a). This results in a configuration in which a portion of the straight portion 21a is sandwiched between the through-hole 51 and the intersection 52. The magnetic core 50 is fixed to the power transmission coil 21 via an intermediate member (not shown).

In addition, while FIG. 4 shows an example of a configuration in which the magnetic core 50 is disposed near the lower side of the power transmission coil 21, the magnetic core 50 may be disposed near the power receiving coil 31. That is, when one of the power transmission coil 21 and the power receiving coil 31 is defined as one coil and the other is defined as the other coil, the magnetic core 50 may be disposed near one of the coils. The above-mentioned separation distance L is the distance between one surface of one coil and the surface of the other coil that faces the one surface. When the magnetic core 50 is disposed near the power receiving coil 31, the magnetic core 50 is fixed to the power receiving coil 31 via an intermediate member. The magnetic core 50 is disposed above the power receiving coil 31. That is, the magnetic core 50 is disposed on the side of one coil opposite to the side facing the other coil.

In the example shown in FIG. 4, the magnetic core 50 is disposed facing a portion of the straight portion 21a. It is possible to freely determine which portion of the straight portion 21a the magnetic core 50 is disposed on. In other words, the magnetic core 50 can be moved in the x-axis direction and the y-axis direction as long as it does not interfere with the power transmission coil 21. The magnetic core 50 may also be disposed near any of the other straight portions (straight portions 21b to 21d). Focusing on the through portion 51 and the intersection portion 52, the through portion 51 and the intersection portion 52 are disposed so as to sandwich not the entirety of the power transmission coil 21 or the power receiving coil 31 but a portion of it. This indicates that a common magnetic core 50 can be used even if the shapes and sizes of the power transmission coil 21 and the power receiving coil 31 are different. This allows for a high degree of freedom in the arrangement and design of the magnetic core 50.

FIG. 5 is a side view showing an example of the configuration of the coil unit in the first embodiment, and is a view of the coil unit 100 viewed from the -y direction. FIG. 5 shows the state during power supply, in which the power transmission coil 21 and the power receiving coil 31 are arranged closer to each other than in the non-power supply state shown in FIG. 4. That is, the separation distance L* during power supply shown in FIG. 5 is smaller than the separation distance L in FIG. 4. The separation distance L* during power supply can be, for example, 10% or less of the maximum width (axial length of the straight portion 21a, etc.) of the power transmission coil 21 and the power receiving coil 31. However, since the strength of the magnetic coupling between the power transmission coil 21 and the power receiving coil 31 also depends on the dimensions of the power transmission coil 21 and the power receiving coil 31, the separation distance L* during power supply is not limited to the above. The penetration portion 51 penetrates only the inside of the power transmission coil 21 in the non-power supply state, but penetrates the inside of the power transmission coil 21 and the power receiving coil 31 during power supply. The intersection 52 intersects only with the power transmission coil 21 in the non-power supply state, but intersects both the power transmission coil 21 and the power receiving coil when power is supplied. The through-hole 51 and the intersection 52 sandwich only the power transmission coil 21 (straight portion 21a) in the non-power supply state, but are arranged to sandwich both the power transmission coil 21 and the power receiving coil 31 (straight portion 21a and straight portion 31a) when power is supplied. As shown in FIG. 5, the through-hole 51 protrudes in the +z direction from the end of the connection portion 53 on the -x direction side, that is, the end on the inner side of the power transmission coil 21 and the power receiving coil 31. The intersection 52 protrudes in the +z direction from the end of the connection portion 53 on the +x direction side, that is, the end on the outer side of the power transmission coil 21 and the power receiving coil 31. As a result, the magnetic core 50 is U-shaped when viewed from the -y direction. In this way, the through portion 51 and the intersection portion 52 protrude from one end and the other end of the connection portion 53 in a direction parallel to the winding axis (z-axis direction) and are arranged to intersect with the xy plane.

Since the penetrating portion 51 penetrates both the power transmitting coil 21 and the power receiving coil 31 during power supply, the length L2 in the z-axis direction of the penetrating portion 51, excluding the thickness of the connecting portion 53 (length in the z-axis direction), is preferably longer than the distance L1, which is the sum of the thickness of the power transmitting coil 21, the thickness of the power receiving coil 31, and the distance (separation distance L*) between the power transmitting coil 21 and the power receiving coil 31. Similarly, the length L3 in the z-axis direction of the intersection portion 52, excluding the thickness of the connecting portion 53, is preferably longer than the distance L1. By setting the distance L1, the length L2, and the length L3 in this manner, the amount of magnetic flux interlinking both the power transmitting coil 21 and the power receiving coil 31 can be increased, and the magnetic coupling between the power transmitting coil 21 and the power receiving coil 31 during power supply can be strengthened.

In FIG. 5, the length L2 of the through portion 51 excluding the thickness of the connection portion 53 and the length L3 of the intersection portion 52 excluding the thickness of the connection portion 53 are equal, but they may be set to different lengths.

In the width direction (x-axis direction) of the connection part 53, the length L5 of the portion where the power transmission coil 21 and the power receiving coil 31 overlap with the magnetic core 50 is preferably set to a length less than 1/2 the length L4 of the power transmission coil 21 and the power receiving coil 31 in the x-axis direction. In other words, in a side view seen from the y-axis direction, which is the magnetic body extension direction, the length of the portion where the connection part 53 and the power transmission coil 21 overlap in the x-axis direction, which is the opposing direction, is preferably shorter than half the length of the power transmission coil 21 in the x-axis direction and half the length of the power receiving coil 31 in the x-axis direction.

To achieve stronger magnetic coupling, the magnetic core 50 needs to be made larger, but the volume occupied by the magnetic core 50 can be reduced by setting the width and position of the magnetic core 50 so that the length L4 and the length L5 satisfy the above relationship. Also, by reducing the volume occupied by the magnetic core 50 in this manner, it is possible to achieve a smaller size and lighter weight. Furthermore, the gap in the magnetic flux path generated when transmitting power from the power transmission coil 21 to the power receiving coil 31 is shortened. This reduces the magnetic resistance and has the effect of strengthening the magnetic coupling. Note that in the example of Figure 5, it is assumed that the magnetic core 50 is placed near the power transmission coil 21. In this case, the connection part 53 is placed below the power transmission coil 21. When the magnetic core 50 is placed near the power receiving coil 31, the connection part 53 is placed above the power receiving coil 31. In addition, to fix the relative positions of the power transmission coil 21 and the power receiving coil 31, and the relative positions of the power transmission coil 21 and the magnetic core 50, structures such as jigs and cases are actually provided as intermediate members, but these intermediate members are omitted from FIG. 5.

FIG. 6 is a plan view showing an example of the configuration of a coil unit in the first embodiment. The view is from the +z direction, and the power transmission coil 21 is not visible, but overlaps with the power receiving coil 31. In FIG. 6, length L6 indicates the length of the magnetic core 50 in the y-axis direction. Length L7 indicates the length of the inner side of the power receiving coil 31 (and the power transmission coil 21) in the x-axis direction and the y-axis direction. Note that in the example shown in FIG. 6, the lengths of the straight portions of the power transmission coil 21 and the power receiving coil 31 are the same, but the straight portions extending in the x-axis direction and the straight portions extending in the y-axis direction may be different in length. The connection portion 53 of the magnetic core 50 faces only a portion of the straight portion 21a of the power transmission coil 21. For this reason, length L6 is smaller than length L7.

Length L8 indicates the width (length in the x-axis direction) of the portion inside the power transmission coil 21 where the connection portion 53 and the straight portion 21a do not overlap, and length L9 indicates the width of the portion outside the power transmission coil 21 where the connection portion 53 and the straight portion 21a do not overlap. In other words, length L8 is the distance between the face on the +x direction side of the through portion 51 and the face on the -x direction side of the straight portion 21a (straight portion 21a and straight portion 31a when power is being supplied). Length L9 is the distance between the face on the -x direction side of the intersection 52 and the face on the +x direction side of the straight portion 21a (straight portion 21a and straight portion 31a when power is being supplied). At this time, width W1 (not shown) of straight portion 21a is length L5 minus the thickness (length in the x-axis direction) of through portion 51 and length L8. Additionally, the width W2 (not shown) of the connection portion 53, excluding the widths (length in the x-axis direction) of the through portion 51 and the intersection portion 52, is the sum of the length L8, the width W1, and the length L9. Therefore, W2>W1 holds. That is, the width of the connection portion 53 is greater than the width of the straight portion 21a of the power transmission coil 21. The position of the magnetic core 50 in the x-axis direction can be adjusted by this margin (the difference between width W2 and width W1).

The power transmission coil 21 described above can be said to be a coil structure having a magnetic core 50 and a coil used for contactless power supply. The magnetic core 50 includes a connection portion 53 that faces a part of the power transmission coil 21 in the z-axis direction, a through portion 51 that protrudes in the z-axis direction from one end of the connection portion 53 in the x-axis direction and penetrates the inside of the power transmission coil 21, and an intersection portion 52 that protrudes in the z-axis direction from the other end of the connection portion 53 and sandwiches a part of the power transmission coil between the through portion 51 and the power transmission coil. The power transmission coil 21 is magnetically coupled to the power receiving coil 31, which is another coil separated in the z-axis direction, during power supply. The power transmission coil 21 magnetically coupled to the power receiving coil 31 transmits power between the power transmission coil 31 and the power receiving coil 31 via magnetic energy. The magnetic core 50 is a magnetic body that strengthens the magnetic coupling between the power transmission coil 21 and the power receiving coil 31 during power supply, and during power supply, the through portion 51 passes through the inside of the power transmission coil 21 and the power receiving coil 31, and the intersection portion 52 intersects with the power transmission coil and the power receiving coil 31. When the magnetic core 50 is disposed near the power receiving coil 31, the power receiving coil 31 corresponds to the coil structure described above.

In the first embodiment, the through portion 51 protrudes from one end of the connection portion 53, and the intersection portion 52 protrudes from the other end of the connection portion 53. However, the through portion 51 only needs to penetrate the inside of the power transmission coil 21 in the non-power supply state, and it only needs to penetrate the inside of both the power transmission coil 21 and the power receiving coil 31 when power is being supplied. Therefore, it is not necessarily required to provide the through portion 51 at one end of the connection portion 53. The same is true for the intersection portion 52, which only needs to intersect with the power transmission coil 21 in the non-power supply state to sandwich the power transmission coil 21 with the through portion 51, and it only needs to intersect with both the power transmission coil 21 and the power receiving coil 31 when power is being supplied to sandwich the power transmission coil 21 and the through portion 51. Therefore, it is not necessarily required to provide the intersection portion 52 at the other end of the connection portion 53. As long as the requirements for the through portion 51 and the intersection portion 52 described above are met, it is possible, for example, to have either or both of the through portion 51 and the intersection portion 52 protrude from the center of the connection portion 53.

7 is a diagram showing an application example of the coil unit in the first embodiment, and shows a specific example of the contactless power supply system 1000. The device shown in FIG. 7 (contactless power supply system 1001) is composed of a power supply rack 1101 corresponding to the power transmitting side device 1100 and a module device 1201 corresponding to the power receiving side device 1200. As shown in FIG. 7, in the contactless power supply system 1001, a plurality of module devices 1201 correspond to one power supply rack 1101. Note that in FIG. 7 and FIG. 8, the up-down direction in the figure is the y-axis direction. A plurality of module devices 1201 can be stored in the power supply rack 1101. The module device 1201 is, for example, a device stored in the number required according to the user's request, and is assumed to be a power source or a control device. The power supply rack 1101 is a rack-type device that can store the module devices 1201 as described above and supplies power to the module devices 1201. The module device 1201 can be stored in or removed from the power supply rack 1101 by sliding it in the z-axis direction.

FIG. 8 is a diagram for explaining the arrangement of each coil in an application example of the coil unit in embodiment 1. In FIG. 8, two module devices 1201A (upper module device in the figure) and 1201B (lower module device in the figure) are explained as an example. The power supply rack 1101 has a power transmission coil 21 attached to its inner back surface. The module devices 1201A and 1201B each have a power receiving coil 31 attached to the surface facing the inner back surface of the power supply rack 1101. The AC power source 10 that supplies AC power to the power transmission coil 21 and the power transmission side resonant capacitor 22 for configuring the power transmission resonant circuit 20 are omitted. These configurations may be provided in the power supply rack 1101, or may be provided outside the power supply rack 1101 and connected to the power transmission coil 21. In short, it is sufficient that the power transmission coil 21 is supplied with AC power and resonance is generated in the power transmission coil 21. Module device 1201A and module device 1201B are provided with a power receiving side resonant capacitor 32 and a power receiving circuit 40 inside, but the description of these configurations is omitted.

The positional relationship between the power transmission coil 21 and the power receiving coil 31 is the same as in the examples shown in Figures 4 and 5, and they are separated by a separation distance (not shown in Figure 8) in the z-axis direction, and the non-power supply state and the power supply state are switched by adjusting this separation distance. This separation distance is adjusted depending on how far back each module device is stored in the power supply rack 1101. In Figure 8, the module device 1201A that is not stored very far is in the non-power supply state, and the module device 1201B that is stored relatively far back is in the power supply state. The magnetic core 50 is also disposed near the power transmission coil 21, as in the examples shown in Figures 4 and 5. The magnetic core 50 has the same configuration, and has a through portion 51, an intersection portion 52, and a connection portion 53. The through portion 51 penetrates only the power transmission coil 21 in the non-power supply state, and penetrates both the power transmission coil 21 and the power receiving coil 31 during power supply, as in the examples shown in Figures 4 and 5. The through-hole 51 does not penetrate the power receiving coil 31 of the module device 1201A, but the through-hole 51 penetrates the power receiving coil 31 of the module device 1201B. The same is true for the intersection of the intersection 52 with the power transmitting coil 21 and the power receiving coil 31.

As shown in the lower module device 1201B, the power transmission coil 21 and the power receiving coil 31 are arranged so that they are close to each other when the module device 1201B is stored deep in the power supply rack 1101. By arranging the magnetic core 50 in the power supply rack 1101 in this way, each module device 1201 only needs to be equipped with the power receiving coil 31, making it possible to reduce the size and weight of the module device 1201. In FIG. 8, components such as the power transmission coil 21 and the power receiving coil 31 are exposed, but in an actual device, they are incorporated into the device so that the surroundings are covered with a resin agent or the like.

The power supply rack 1101 is provided with a guide rail 1101a extending in the z-axis direction, and the module device 1201A slides on the guide rail 1101a. By providing the guide rail 1101a, the movement of the module devices 1201A and 1201B in the z-axis direction is stabilized, making it easier to adjust the separation distance between the power transmission coil 21 and the power receiving coil 31.

Note that the mounting position of the power transmission coil 21 in the power supply rack 1101 and the mounting position of the power receiving coil 31 in the module device 1201 are not limited to those shown in FIG. 8. It is sufficient that the module device 1201 is positioned so that the separation distance between the power transmission coil 21 and the power receiving coil 31 can be adjusted by moving the module device 1201.

According to the first embodiment, it is possible to increase the degree of freedom in the arrangement of the magnetic core while maintaining the strength of the magnetic coupling between the power transmission coil and the power receiving coil during power supply. More specifically, the coil unit includes a power transmission coil and a power receiving coil that have parallel winding axes and are separated by a distance in the winding axis direction, the power transmission coil and the power receiving coil are magnetically coupled during power supply to transmit AC power from the power transmission coil to the power receiving coil, and a magnetic core that strengthens the magnetic coupling between the power transmission coil and the power receiving coil during power supply, the magnetic core includes a connection portion that faces a part of the power transmission coil or the power receiving coil in the winding axis direction, a through portion that protrudes from one end of the connection portion in the winding axis direction and penetrates the inside of the power transmission coil or the power receiving coil, and an intersection portion that protrudes from the other end of the connection portion in the winding axis direction and sandwiches a part of the power transmission coil or the power receiving coil with the through portion, and during power supply, the through portion penetrates the power transmission coil and the power receiving coil, and the intersection portion intersects the power transmission coil and the power receiving coil.

The magnetic core is arranged to face a part of either the power transmission coil or the power receiving coil, and the position can be adjusted within a range that does not interfere with the power transmission coil or the power receiving coil. This allows for a high degree of freedom in the arrangement of the magnetic core. In addition, the through-hole and intersection of the magnetic core are also arranged to surround only a part of the power transmission coil and the power receiving coil, not the entirety. This allows a common magnetic core to be used even if the power transmission coil and the power receiving coil are different in shape and size. This allows for a high degree of freedom in the arrangement and design of the magnetic core. In addition, when power is being supplied, the through-hole penetrates the inside of both the power transmission coil and the power receiving coil, and the intersection intersects with both the power transmission coil and the power receiving coil. This makes it possible to increase the amount of magnetic flux interlinking with both coils and to strengthen the magnetic coupling. This allows the magnetic core to maintain its effect of strengthening the strength of the magnetic coupling between the power transmission coil and the power receiving coil.

Furthermore, in the opposing direction of the penetration portion and intersection portion, the length of the portion where the connection portion of the magnetic core overlaps with the power transmission coil is shorter than half the length of the power transmission coil in the opposing direction and shorter than half the length of the power receiving coil in the opposing direction. In this way, by setting the length of the portion where the power transmission coil and power receiving coil overlap with the magnetic core to a length less than half the length of the power transmission coil and power receiving coil in the same direction (the opposing direction), the volume of magnetic material required for the magnetic core can be reduced, making it smaller and lighter.

Embodiment 2.
Next, a second embodiment will be described with reference to Figs. 9 to 12. The same or corresponding configurations as those shown in Figs. 1 to 8 are denoted by the same reference numerals, and the description thereof will be omitted. The contactless power supply system is the same as that of the first embodiment, and therefore the description of the entire contactless power supply system will be omitted. Fig. 9 is a perspective view showing a configuration example of a coil unit in the second embodiment. Fig. 9 shows a non-power supply state in which the power transmission coil 21 and the power receiving coil 31 are separated by a certain distance or more. The coil unit 200 includes the power transmission coil 21, the power receiving coil 31, the magnetic core 50, and the second magnetic core 60, i.e., the second magnetic body. The power transmission coil 21, the power receiving coil 31, and the magnetic core 50 are the same as those of the first embodiment.

The second magnetic core 60 is a plate-shaped magnetic body having a thickness in the z-axis direction and extending along the x-axis direction and the y-axis direction. The second magnetic core 60 is disposed in the vicinity of the upper part of the receiving coil 31, and the lower surface of the second magnetic core 60 faces at least a part of one straight portion of the rectangular receiving coil 31. In the example shown in FIG. 9, the second magnetic core 60 faces a part of the upper surface of the straight portion 31a of the receiving coil 31 in the z-axis direction. In FIG. 9, the second magnetic core 60 is disposed in the vicinity of the straight portion 31a. As described above, the magnetic core 50 is disposed in the vicinity of the lower part of the transmitting coil 21. The magnetic core 50 and the second magnetic core 60 are fixed to the transmitting coil 21 and the receiving coil 31, respectively, via intermediate members not shown.

When the magnetic core 50 is placed on one side (below) of one coil (power transmission coil 21), the second magnetic core 60 is placed on the other side (above) of the other coil (power receiving coil 31). When the magnetic core 50 is placed above the power receiving coil 31, the second magnetic core 60 is placed below the power transmitting coil 21. In other words, the second magnetic core 60 is placed on the opposite side of the other coil from the side facing the one coil.

Note that FIG. 9 shows an example of a configuration in which the magnetic core 50 is disposed near the lower side of the power transmission coil 21 and the second magnetic core 60 is disposed near the upper side of the power receiving coil 31, but the magnetic core 50 may be disposed near the power receiving coil 31 and the second magnetic core 60 may be disposed near the power transmission coil 21. As described above, FIG. 9 shows the non-powered state, so the penetration portion 51 of the magnetic core 50 penetrates only the power transmission coil 21 and the intersection portion 52 intersects only with the power transmission coil 21. The second magnetic core 60 is disposed so as not to penetrate any coils or intersect with any coils. For example, the second magnetic core 60 is disposed parallel to the upper surface of the power receiving coil 31.

FIG. 10 is a side view showing an example of the configuration of a coil unit in embodiment 2, and is a view of the coil unit 200 from the -y direction. FIG. 10 shows the state when power is being supplied, in which the power transmission coil 21 and the power receiving coil 31 are arranged closer to each other than in the non-power supply state shown in FIG. 9. In other words, the separation distance L* when power is being supplied shown in FIG. 10 is smaller than the separation distance L in FIG. 9. The magnetic core 50 is the same as in embodiment 1, so its description is omitted. The second magnetic core 60 seen from the -y direction has a flat plate shape that extends linearly along the x-axis direction, and its lower surface forms an opposing surface 60a that faces the magnetic core 50 in the z-axis direction. The second magnetic core 60 is arranged close to both the through portion 51 and the intersection portion 52 of the magnetic core 50 when power is being supplied. In FIG. 10, even when power is being supplied, there is a gap between the magnetic core 50, more specifically, the upper end surface of the through portion 51 and the upper end surface of the intersection portion 52, and the second magnetic core 60, more specifically, the opposing surface 60a. However, the magnetic core 50 and the second magnetic core 60 may be in contact with each other when power is being supplied. Also, the second magnetic core 60 does not need to be flat as a whole as long as it is close to both the through portion 51 and the intersection portion 52 of the magnetic core 50 when power is being supplied. It may have a shape with a bent portion or a curved portion depending on the shape of the receiving coil 31 and the magnetic core 50.

10, the length L2 of the through portion 51 excluding the thickness of the connection portion 53 and the length L3 of the intersection portion 52 excluding the thickness of the connection portion 53 are equal to each other as in the first embodiment. However, the length L2 and the length L3 may be set to different lengths. Even when the length L2 and the length L3 are different, it is preferable that the second magnetic core 60 is arranged so as to be in close proximity to or in contact with both the through portion 51 and the intersection portion 52. Also, in FIG. 10, the end of the second magnetic core 60 (the end in the x-axis direction in FIG. 10) and the end of the magnetic core 50, more specifically, the upper end of the through portion 51 and the upper end of the intersection portion 52 are in close proximity to each other, but the above ends do not need to be in close proximity to each other, and one end may be in close proximity to the center of the other (the portion between one end and the other end of the other). For example, the -x-direction end of the second magnetic core 60 may be configured to be located directly above the center of the magnetic core 50 in the x-axis direction, or the through portion 51 or the intersection portion 52 may be configured to be located directly below the center of the second magnetic core 60 in the x-axis direction.

Furthermore, in the width direction (x-axis direction) of the connection portion 53, the length L5 of the portion where the power transmission coil 21 and the power receiving coil 31 overlap with the magnetic core 50 and the second magnetic core 60 is preferably set to a length less than 1/2 the length L4 of the power transmission coil 21 and the power receiving coil 31 in the x-axis direction. By setting the width and arrangement position of the magnetic core 50 and the second magnetic core 60 in this manner, the volume of the required magnetic body can be reduced, as in the first embodiment. Also, by reducing the volume of the required magnetic body, it is possible to achieve miniaturization and weight reduction, as in the first embodiment. The gap in the magnetic flux path generated when transmitting power from the power transmission coil 21 to the power receiving coil 31 is shortened, and the magnetic resistance is reduced, which has the effect of strengthening the magnetic coupling, as in the first embodiment.

It is also possible that the second magnetic core 60 has the same configuration as the first magnetic core 50, i.e., a through portion, an intersection portion, and a connection portion. The second magnetic core 601 shown in Fig. 11 has an inverted U-shaped cross section that is upside down compared to the magnetic core 50, and includes a through portion 61 that passes through the inside of the power receiving coil 31, an intersection portion 62 that intersects with the power receiving coil 31 on the outside of the power receiving coil 31, and a connection portion 63. The through portion 61, the intersection portion 62, and the connection portion 63 of the second magnetic core 601 correspond to the through portion 51, the intersection portion 52, and the connection portion 53 of the magnetic core 50, respectively.
When such a second magnetic core 601 is used, the sum of the length of the through portion 51 in the z-axis direction (excluding the thickness of the connection portion 53) and the length of the through portion 61 in the z-axis direction (excluding the thickness of the connection portion 63) corresponds to the length L2 in Fig. 10. In Fig. 11, this is indicated as length L2*. Also, the sum of the length of the intersection portion 52 in the z-axis direction (excluding the thickness of the connection portion 53) and the length of the intersection portion 62 in the z-axis direction (excluding the thickness of the connection portion 63) corresponds to the length L3 in Fig. 10. In Fig. 11, this is indicated as length L3*.

12 is a plan view showing an example of the configuration of the coil unit in the second embodiment. As in the example of FIG. 10, the ends of the second magnetic core 60 (in the case of FIG. 12, the ends in the x-axis direction and the y-axis direction) and the ends of the magnetic core 50 (the upper end of the through-hole 51 and the upper end of the intersection 52) are configured to be close to each other when power is supplied, so in FIG. 12, which is a view from the +z direction, the second magnetic core 60 covers the entire magnetic core 50. However, as described above, the end of the second magnetic core 60 does not necessarily have to be close to the end of the magnetic core 50 when power is supplied, so the magnetic core 50 may be exposed in the plan view depending on the positional relationship between the magnetic core 50 and the second magnetic core 60.

According to the second embodiment, the same effects as those of the first embodiment can be obtained.
In addition, it is possible to increase the amount of magnetic flux interlinking both coils and strengthen the magnetic coupling. More specifically, a second magnetic core is provided in the receiving coil. The second magnetic core is close to the penetration part and the intersection part of the magnetic core when power is being supplied. Therefore, by forming a magnetic flux path by the two magnetic cores, it is possible to increase the amount of magnetic flux interlinking both coils. As a result, it is possible to strengthen the magnetic coupling.

Embodiment 3.
Next, the third embodiment will be described with reference to Figs. 13 to 16. The same or corresponding configurations as those shown in Figs. 1 to 12 are denoted by the same reference numerals, and the description thereof will be omitted. The contactless power supply system is the same as that of the first embodiment, and therefore the description of the entire contactless power supply system will be omitted. Fig. 13 is a perspective view showing a configuration example of a coil unit in the third embodiment. Fig. 13 shows a non-power supply state in which the power transmission coil 21 and the power receiving coil 31 are spaced apart from each other by a certain distance or more. Although not shown in Fig. 13, the power transmission coil 21 and the power receiving coil 31 are also spaced apart from each other by a distance L in the direction of their respective winding axes (z-axis direction). In the third embodiment, the magnetic core 50 is a plurality of magnetic cores 50A to 50D. The coil unit 300 includes the power transmission coil 21, the power receiving coil 31, and the magnetic cores 50A to 50D. The magnetic cores 50A to 50D are arranged near the straight portions 21a to 21d, respectively. The configuration of the magnetic cores 50A to 50D is the same as that of the magnetic core 50 in the first embodiment. The positions of the magnetic cores 50A to 50D are also the same as those of the magnetic core 50, and they are arranged below the respective straight sections. As described above, Fig. 13 shows a non-powered state, and therefore the penetration sections of the magnetic cores 50A to 50D penetrate only the power transmission coil 21, and the intersection sections intersect only with the power transmission coil 21. In the example shown in Fig. 13, a total of four magnetic cores 50 are arranged, one on each straight section of the power transmission coil 21, but it is sufficient that at least two or more magnetic cores 50 are arranged.

Also, some of the magnetic cores 50 may be arranged near the receiving coil 31. Although not shown, for example, when the magnetic core 50B is arranged as the other magnetic core near the straight portion 31b of the receiving coil 31, the magnetic core 50B, i.e., the other magnetic core, is arranged so as to cover a part of the upper side of the straight portion 31b of the receiving coil 31. The magnetic core 50B as the other magnetic core has a other through portion (not shown) that protrudes in the -z direction and penetrates the inside of the receiving coil 31, a other intersection portion (not shown) that faces the other through portion and intersects with the receiving coil 31 on the outside of the receiving coil 31, and a other connection portion (not shown) that extends along the x-axis direction and the y-axis direction and connects the other through portion and the other intersection portion. In the non-powered state, the other through portion penetrates only the receiving coil 31, and the other intersection portion intersects only with the receiving coil 31. When power is being supplied, the other through-hole passes through the power receiving coil 31 and the power transmitting coil 21, and the other intersecting part intersects with the power receiving coil 31 and the power transmitting coil 21.

As described above, it is arbitrary whether each of the magnetic cores 50A to 50D is placed near the power transmission coil 21 or the power receiving coil 31. All four may be placed near the power transmission coil 21, or all four may be placed near the power receiving coil 31. It is also possible to place some near the power transmission coil 21 and the rest near the power receiving coil 31. That is, in the third embodiment, each of the multiple magnetic cores 50 is placed near either the power transmission coil 21 or the power receiving coil 31. Note that the placement and shape of each magnetic core 50 (including the other magnetic core) are set so that they do not interfere with each other in the non-power supply state and when power is being supplied. Specifically, when the magnetic core 50 (or the other magnetic core) is placed near both the power transmission coil 21 and the power receiving coil 31, it is possible to place the magnetic core 50 (or the other magnetic core) on at most only one of the corresponding straight sections, such as the straight section 21a and the straight section 31a. In addition, when magnetic cores 50 are placed on both of the corresponding straight sections, it is possible to adjust the width (length in the x-axis direction) of the connection section 53 (or the other connection section) and reduce the separation distance L between the power transmission coil 21 and the power receiving coil 31 during power supply, thereby avoiding interference between the connection section and the other connection, and between the intersection section and the other intersection section.

As mentioned above, the shapes of the power transmission coil 21 and the power receiving coil 31 are not limited to rectangular. The shape of both or either one of the power transmission coil 21 and the power receiving coil 31 may be polygonal with N sides (N is any natural number equal to or greater than 3). Even in such a case, each of the multiple magnetic cores 50 may be arbitrarily assigned to the N straight portions of the power transmission coil 21 and the power receiving coil 31. For example, all of the magnetic cores 50 may be arranged in the power transmission coil 21, or only some of the magnetic cores 50 may be arranged in the power receiving coil 31. Furthermore, even if some or all of the power transmission coil 21 and the power receiving coil 31 are curved, magnetic cores 50 that match the shapes of the power transmission coil 21 and the power receiving coil 31 may be used.

FIG. 14 is a side view showing an example of the configuration of a coil unit in embodiment 3, and is a view of coil unit 300 from the -y direction. FIG. 14 shows the state when power is being supplied, in which power transmission coil 21 and power receiving coil 31 are arranged closer together than in the non-powered state shown in FIG. 13. In other words, the separation distance L* when power is being supplied shown in FIG. 14 is smaller than the separation distance L in the non-powered state. In embodiment 3, the structure and dimensions of each of magnetic cores 50A-50D are set to be generally similar to those of magnetic core 50 in embodiment 1. For example, focusing on magnetic core 50A arranged on the +x direction side in the figure, magnetic core 50A has a through portion 51A, an intersection portion 52A, and a connection portion 53A. Because the penetrating portion 51A penetrates the power transmitting coil 21 and the power receiving coil 31, the length L2 in the z-axis direction of the penetrating portion 51A, excluding the thickness (length in the z-axis direction) of the connecting portion 53A, is preferably longer than the distance L1, which is the sum of the thickness of the power transmitting coil 21, the thickness of the power receiving coil 31, and the distance (separation distance L*) between the power transmitting coil 21 and the power receiving coil 31. Similarly, the length L3 in the z-axis direction of the intersection portion 52A, excluding the thickness of the connecting portion 53A, is preferably longer than the distance L1.

In the width direction (x-axis direction) of the connection portion 53A, the length L5 of the portion where the power transmission coil 21 and the power receiving coil 31 overlap with the magnetic core 50A is preferably set to a length less than 1/2 the length L4 of the power transmission coil 21 and the power receiving coil 31 in the x-axis direction.

The above also applies to magnetic core 50C located on the -x-direction side, so a description will be omitted. The same can be said about lengths L4 and L5 described above for magnetic core 50B, which is located in the center in the x-direction, with the exception that the width direction of its connection part (not shown) is in the y-direction.

Different from the first embodiment, the multiple magnetic cores 50A-50D must be shaped and positioned so that they do not interfere with each other. Furthermore, it is desirable that all magnetic cores 50A-50D have the same shape. This makes it possible to minimize the variety of shapes of the magnetic cores to be manufactured, and to reduce the cost of manufacturing magnetic cores of different shapes. However, it is not necessary to set the magnetic cores 50A-50D to the same shape, and the effect of strengthening the magnetic coupling can be obtained even if they are all different shapes.

The case where a magnetic core is arranged on each of the corresponding straight sections of the power transmission coil 21 and the power receiving coil 31 will be described. FIG. 15 is a side view showing an example of the configuration of a coil unit in embodiment 3, and is a diagram showing a case where a magnetic core is arranged on each of the corresponding straight sections of the power transmission coil and the power receiving coil. FIG. 16 is also a diagram explaining the magnetic core and the other magnetic core. In the example shown in FIG. 15, in addition to the example shown in FIG. 14, the other magnetic core 50C* is arranged above the straight section 31c of the power receiving coil 31. As can be seen from FIG. 13, the straight section 21c and the straight section 31c are straight sections that correspond to each other. The magnetic core 50C has a through section 51C, an intersection section 52C, and a connection section 53C like the magnetic core 50. The other magnetic core 50C* also has the other through section 51C*, the other intersection section 52C*, and the other connection section 53C*. As shown in FIG. 15, during power supply, the through portion 51C and the other through portion 51C* pass through both the power transmitting coil 21 and the power receiving coil 31. In addition, the intersection portion 52C and the other intersection portion 52C* intersect with both the power transmitting coil 21 and the power receiving coil 31.

However, it is necessary to prevent the through portion 51C from interfering with the other through portion 51C*. For this reason, as shown in FIG. 16, the length L3 in the z-axis direction of the through portion 51C and the intersection portion 52C, excluding the thickness of each of the connection portions 53C, is longer than the length L3** in the z-axis direction of the other through portion 51C* and the other intersection portion 52C*, excluding the thickness of each of the other connection portions 53C*. In addition, the width of the connection portion 53C, excluding the thickness (length in the x-axis direction) of each of the through portion 51C and the intersection portion 52C, i.e., the length L10 in the x-axis direction, is longer than the width of the other connection portion 53C*, including the thickness (length in the x-axis direction) of each of the other through portion 51C* and the other intersection portion 52C*, i.e., the length L10* in the x-axis direction. For this reason, even if the power transmission coil 21 and the power receiving coil 31 are close to each other during power supply, the other magnetic core 50C* is configured to enter inside the magnetic core 50C. In addition, the tip end (the end in the -z direction) of the other through portion 51C* and the other intersection portion 52C* does not come into contact with the upper surface of the connection portion 53C. Therefore, there is no interference between the magnetic core 50C and the other magnetic core 50C*.

According to the third embodiment, the same effects as those of the first embodiment can be obtained.
In addition, it is possible to further strengthen the magnetic coupling between the power transmission coil and the power receiving coil during power supply. More specifically, a plurality of magnetic cores are arranged near the power transmission coil or the power receiving coil. Therefore, there are at least two or more penetration parts penetrating the inside of the power transmission coil and the power receiving coil during power supply. In addition, there are at least two or more intersection parts intersecting with the power transmission coil and the power receiving coil during power supply. As a result, the amount of magnetic flux interlinking both coils is further increased, making it possible to strengthen the magnetic coupling more than in the first embodiment. In addition, it is also possible to adjust the strength of the magnetic coupling by adjusting the number of magnetic cores.

Furthermore, by using multiple magnetic cores, it is possible to suppress misalignment between the transmitting coil and the receiving coil when power is being supplied. Note that in order to suppress misalignment, it is also possible to use a magnetic core that is integrally formed so as to surround the transmitting coil and the receiving coil at multiple points. In that case, the degree of freedom in layout and design is reduced. In contrast, if multiple magnetic cores that are independent of each other are used, the positions of the multiple magnetic cores can be changed when the shapes and sizes of the coils differ, ensuring the degree of freedom in design and layout. As described above, the magnetic core to be used can be determined according to the purpose.

Furthermore, by arbitrarily allocating the placement of multiple magnetic cores near the power transmission coil and near the power receiving coil, it is possible to adjust the amount of magnetic material placed on the power transmission side and the power receiving side. As a result, it is possible to realize a configuration in which no magnetic cores are placed on the side of equipment where miniaturization and weight reduction are desired.

Embodiment 4.
Next, the fourth embodiment will be described with reference to Figs. 17 and 18. The same or corresponding configurations as those shown in Figs. 1 to 16 are denoted by the same reference numerals, and the description thereof will be omitted. The contactless power supply system is the same as that of the first embodiment, and therefore the description of the entire contactless power supply system will be omitted. Fig. 17 is a perspective view showing a configuration example of a coil unit in the fourth embodiment. Fig. 17 shows a non-power supply state in which the power transmission coil 21 and the power receiving coil 31 are spaced apart by a certain distance or more. Although not shown in Fig. 17, the power transmission coil 21 and the power receiving coil 31 are also spaced apart by a separation distance L in the direction of their respective winding axes (z-axis direction). In the fourth embodiment, the second magnetic core 60 is replaced by a plurality of second magnetic cores 60A to 60D. The coil unit 400 includes the power transmission coil 21, the power receiving coil 31, the magnetic cores 50A to 50D, and the second magnetic cores 60A to 60D. The magnetic cores 50A to 50D are the same as those in the third embodiment. As described above, since FIG. 17 shows a non-powered state, the through portions of each of the magnetic cores 50A to 50D pass only through the power transmission coil 21, and the intersecting portions intersect only with the power transmission coil 21.

The second magnetic cores 60A to 60D are disposed near the straight sections 31a to 31d, respectively. The configuration of the second magnetic cores 60A to 60D is the same as the second magnetic core 60 in embodiment 2. In the example shown in FIG. 17, one magnetic core is disposed on each straight section of the power transmission coil 21, for a total of four, and one second magnetic core 60 is disposed on each straight section of the power receiving coil 31, for a total of four, but it is sufficient that at least two of each of the magnetic cores 50 and second magnetic cores 60 are disposed.

Also, when some of the magnetic cores 50 are arranged near the receiving coil 31 as the other magnetic core, the same may be done for the second magnetic core. That is, some of the second magnetic cores 60 may be arranged near the transmitting coil 21 as the other second magnetic core in correspondence with the other magnetic core. Although not shown, for example, when the magnetic core 50B is arranged near the straight portion 31b of the receiving coil 31 to be the other magnetic core, the second magnetic core 60B is arranged near the straight portion 21b of the transmitting coil 21 in correspondence with the magnetic core 50B. In this case, the second magnetic core 60B becomes the other second magnetic core. In this case, the magnetic core 50B, i.e., the other magnetic core, is arranged so as to cover a part of the upper side of the straight portion 31b of the receiving coil 31, so that the second magnetic core 60B, which is the other second magnetic core, is arranged below the straight portion 21b.

As described above, it is optional whether each of the magnetic cores 50A-50D is placed near the power transmission coil 21 or the power receiving coil 31. All four may be placed near the power transmission coil 21, or all four may be placed near the power receiving coil 31. The second magnetic cores 60A-60D are placed in correspondence with the magnetic cores 50A-50D, so depending on the placement of the magnetic cores 50A-50D, all four may be placed near the power receiving coil 31, or all four may be placed near the power transmission coil 21. Also, some may be placed near the power receiving coil 31 and the rest may be placed near the power transmission coil 21. That is, in the fourth embodiment, each of the multiple magnetic cores 50 is placed near either the power transmission coil 21 or the power receiving coil 31, and each of the multiple second magnetic cores 60 is placed near the other coil. The arrangement and shape of each magnetic core 50 and each second magnetic core 60 are set so that they do not interfere with each other when power is not being supplied and when power is being supplied.

In the example shown in FIG. 17, the number of magnetic cores 50 and the number of second magnetic cores 60 are four, which is the same, but the number of second magnetic cores 60 may be fewer than the number of magnetic cores 50, and the second magnetic cores 60 may be arranged partially.

FIG. 18 is a side view showing a configuration example of a coil unit according to a fourth embodiment;
This is a view of the coil unit 400 as seen from the -y direction. Fig. 18 shows a state during power supply, in which the power transmitting coil 21 and the power receiving coil 31 are arranged closer to each other than in the non-power supply state shown in Fig. 17. In other words, the separation distance L* during power supply shown in Fig. 14 is smaller than the separation distance L in the non-power supply state.

In the fourth embodiment, the structure and dimensions of each of the magnetic cores 50A to 50D are set to be generally similar to the magnetic core 50 in the first embodiment. Also, the structure and dimensions of each of the second magnetic cores 60A to 60D are set to be generally similar to the second magnetic core 60 in the second embodiment. For example, focusing on the magnetic core 50A and the second magnetic core 60A arranged on the +x-direction side in the figure, the magnetic core 50A has a through portion 51A, an intersection portion 52A, and a connection portion 53A. Since the through portion 51A passes through the power transmission coil 21 and the power receiving coil 31, it is preferable that the length L2 in the z-axis direction of the through portion 51A excluding the thickness (length in the z-axis direction) of the connection portion 53A is longer than the distance L1 which is the sum of the thickness of the power transmission coil 21, the thickness of the power receiving coil 31, and the distance (separation distance L*) between the power transmission coil 21 and the power receiving coil 31. Similarly, it is preferable that the length L3 of the intersection 52A in the z-axis direction, excluding the thickness of the connection portion 53A, is longer than the distance L1.

Furthermore, in the width direction (x-axis direction) of the connection portion 53A, the length L5 of the portion where the power transmission coil 21 and the power receiving coil 31 overlap with the magnetic core 50A and the second magnetic core 60A is preferably set to a length less than 1/2 the length L4 of the power transmission coil 21 and the power receiving coil 31 in the x-axis direction.

When viewed from the -y direction, the second magnetic core 60A has a flat plate shape extending linearly along the x-axis direction, and its lower surface is an opposing surface 60a that faces the magnetic core 50A in the z-axis direction. The second magnetic core 60A is disposed in close proximity to both the through-portion 51A and the intersection 52A of the magnetic core 50A during power supply. In FIG. 18, even during power supply, there is a gap between the magnetic core 50A, more specifically, the upper end surface of the through-portion 51A and the upper end surface of the intersection 52A, and the second magnetic core 60A, more specifically, the opposing surface 60a, but the magnetic core 50A and the second magnetic core 60A may be in contact with each other during power supply. In addition, the second magnetic core 60A does not need to be flat as a whole as long as it is in close proximity to both the through-portion 51A and the intersection 52A of the magnetic core 50A during power supply. It may have a shape having a bent portion or a curved portion depending on the shape of the receiving coil 31 and the magnetic core 50.

The above also applies to magnetic core 50C and second magnetic core 60C arranged on the -x-direction side, so a description will be omitted. The difference with magnetic core 50B and second magnetic core 60B arranged in the center in the x-axis direction is that the width direction of their connection part (not shown) is the y-axis direction, but the same can be said about the lengths L4 and L5 described above.

The difference from the second embodiment is that the multiple magnetic cores 50A-50D and the second magnetic cores 60A-60D must be shaped and arranged so as not to interfere with each other. Furthermore, it is desirable that all the magnetic cores 50A-50D have the same shape. It is also desirable that all the second magnetic cores 60A-60D have the same shape. By doing so, the variety of shapes of the magnetic cores and the second magnetic cores to be manufactured can be minimized, and the cost of manufacturing magnetic cores of different shapes can be reduced. However, it is not necessary to set the magnetic cores 50A-50D to the same shape, and the effect of strengthening the magnetic coupling can be obtained even if they are all different shapes. Furthermore, it is not necessary to set the second magnetic cores 60A-60D to the same shape, and the effect of strengthening the magnetic coupling can be obtained even if they are all different shapes.

According to the fourth embodiment, the same effects as those of the second embodiment can be obtained.
In addition, it is possible to further strengthen the magnetic coupling between the power transmission coil and the power receiving coil during power supply. More specifically, a plurality of magnetic cores are arranged near the power transmission coil or the power receiving coil, and a plurality of second magnetic cores are arranged near the power receiving coil or the power transmission coil corresponding to the magnetic cores. Therefore, there are at least two or more penetration parts penetrating the inside of the power transmission coil and the power receiving coil during power supply. In addition, there are at least two or more intersection parts intersecting with the power transmission coil and the power receiving coil during power supply, and there are at least two or more second magnetic cores adjacent to the penetration parts and intersection parts of the magnetic core during power supply. As a result, the amount of magnetic flux interlinked with both coils is further increased, making it possible to strengthen the magnetic coupling more than in the second embodiment. In addition, it is also possible to adjust the strength of the magnetic coupling by adjusting the number of magnetic cores and second magnetic cores.

In addition, there are multiple pairs of magnetic cores and second magnetic cores, and each pair is independent of the others. Therefore, similar to the third embodiment, freedom of design and layout is ensured.

In addition, by adjusting the arrangement of the multiple magnetic cores and the multiple second magnetic cores, it is possible to adjust the amount of magnetic material arranged on the power transmitting side and the power receiving side. For example, if the second magnetic core is lighter than the magnetic core, more second magnetic cores can be arranged in the equipment where miniaturization and weight reduction are desired.
(Other Modifications)

In each of the above-mentioned embodiments, the magnetic core and the second magnetic core are disposed near the straight portion of the rectangular power transmission coil and power receiving coil. However, the magnetic core and the second magnetic core do not necessarily have to be disposed near the straight portion. For example, the magnetic core and the second magnetic core may be disposed near the corner of the rectangular coil. FIG. 19 is a perspective view showing an example in which the magnetic core and the second magnetic core are disposed at the corners of the power transmission coil and the power receiving coil, respectively. Note that FIG. 19 shows a non-powered state in which the power transmission coil 21 and the power receiving coil 31 are separated by a certain distance or more. Here, a modified example of the second embodiment is used as an example, but similar modifications are possible for the other embodiments described above. The coil unit 201 includes the power transmission coil 21, the power receiving coil 31, the magnetic core 501, and the second magnetic core 602. The power transmission coil 21 and the power receiving coil 31 are the same as those in the first embodiment.

The magnetic core 501 is disposed near a corner that connects the straight portion 21a and the straight portion 21d. The magnetic core 501 includes a through portion 511 that protrudes in the +z direction and penetrates the inside of the power transmission coil 21, an intersection portion 521 that faces the through portion 511 and intersects with the power transmission coil 21 on the outside of the power transmission coil 21, and a connection portion 531 that extends along the x-axis direction and the y-axis direction and connects the through portion 511 and the intersection portion 521. The through portion 511 has a portion that follows the inner surface of the straight portion 21a and a portion that follows the inner surface of the straight portion 21d, and has an L-shaped cross section when viewed from the z-axis direction. The intersection portion 521 has a portion that follows the outer surface of the straight portion 21a and a portion that follows the outer surface of the straight portion 21d, and has an L-shaped cross section when viewed from the z-axis direction. The through portion 511 has a shape that fits along the inside of the corner of the power transmitting coil 21 and is fixed to the inside of the corner. The intersection portion 521 has a shape that fits along the outside of the corner of the power transmitting coil 21 and is fixed to the outside of the corner.

Furthermore, like the through portion 51 in the first embodiment, the through portion 511 only passes through the inside of the power transmission coil 21 in the non-powered state, and passes through the insides of the power transmission coil 21 and the power receiving coil 31 when power is being supplied. Similarly, the intersection portion 521 only intersects with the power transmission coil 21 in the non-powered state, and intersects with the power transmission coil 21 and the power receiving coil 31 when power is being supplied.

The second magnetic core 602 is disposed near the upper corner connecting the straight portion 31a and the straight portion 31d. The second magnetic core 602 is a plate-shaped magnetic body having a thickness in the z-axis direction and extending in the diagonal direction of the power receiving coil 31. The second magnetic core 602 has an end portion on the outer side of the power receiving coil 31 and an end portion on the inner side of the power receiving coil 31 in the diagonal direction. The end portion on the inner side is provided with a protruding portion 602b that protrudes to the inside of the power receiving coil 31. The end portion on the outer side is provided with a protruding portion 602c that protrudes to the outside of the power receiving coil 31. The protruding portion 602b is provided with a cut from the inner side of the power receiving coil 31. As a result, the protruding portion 602b when viewed from below protrudes to the inside of the power receiving coil 31 as an L-shaped portion, and the lower surface of the protruding portion 602b faces the upper end surface of the through portion 511. The protrusion 602c is an isosceles triangular protrusion with a diagonal of the power receiving coil 31 as a center line, and the protrusion 602c, as viewed from below, is an L-shaped part that protrudes outward from the power receiving coil 31. As a result, the lower surface of the protrusion 602c faces the upper end surface of the intersection 521. Note that the above-described shapes of the protrusions 602b and 602c are merely examples, and it is sufficient that at least a part of the lower surface of the protrusions 602b and 602c corresponds to the facing surface 60a of the second embodiment and the like. That is, it is sufficient that at least a part of the lower surface of the protrusion 602b faces the upper end surface of the through portion 511, and at least a part of the lower surface of the protrusion 602c faces the upper end surface of the intersection 521.
The rest of the configuration is the same as that of embodiment 2. Even if the magnetic core and the second magnetic core are provided at the corners of the power transmitting coil and the power receiving coil as in this modified example, the same effects as those of embodiment 2 can be obtained.

Next, an example in which the power transmitting coil and the power receiving coil are not rectangular will be described. Figure 20 is a perspective view showing an example in which a magnetic unit is arranged on a hexagonal power transmitting coil and a hexagonal power receiving coil. Note that Figure 20 shows the state during power supply, in which the power transmitting coil 211 and the power receiving coil 311 are close to each other. Also, a modified example of the third embodiment is used as an example here, but similar modifications are possible for the other embodiments. The coil unit 301 includes a power transmitting coil 211, a power receiving coil 311, and magnetic cores 502A to 502C. Each of the power transmitting coil 211 and the power receiving coil 311 is a coil wound around a virtual winding axis (z-axis in Figure 20) along a virtual plane perpendicular to the winding axis (xy plane in Figure 20). In the power transmission coil 211, adjacent straight sections, such as straight section 211a and straight section 211b, form angles of 120°, and the entire coil (straight sections 211a to 211f and the corners connecting each straight section) forms a regular hexagonal coil. Similarly, in the power reception coil 311, adjacent straight sections, such as straight section 311a and straight section 311b, form angles of 120°, and the entire coil (straight sections 311a to 311f and the corners connecting each straight section) forms a regular hexagonal coil.

Magnetic cores 502A, 502B, and 502C are disposed near straight portions 211b, 211d, and 211f, respectively. The configuration and arrangement of magnetic cores 502A, 502B, and 502C are the same as those of magnetic core 50 in embodiment 1. Taking magnetic core 502C as an example, magnetic core 502C includes a through portion 512C that protrudes in the +z direction and penetrates the inside of power transmission coil 211 and power receiving coil 311, an intersection portion 522C that faces through portion 512C and intersects with power transmission coil 211 and power receiving coil 311 on the outside of power transmission coil 211 and power receiving coil 311, and a connection portion 532C that extends along the x-axis direction and the y-axis direction and connects through portion 512C and intersection portion 522C. As described above, FIG. 20 shows the state during power supply, in which the power transmission coil 211 and the power receiving coil 311 are close to each other, so the through portion 512C passes through both the power transmission coil 211 and the power receiving coil 311. Also, the intersection portion 522C intersects with both the power transmission coil 211 and the power receiving coil 311. When the power transmission coil 211 and the power receiving coil 311 are separated by a certain distance or more in the non-power supply state, the through portion 512C passes only through the inside of the power transmission coil 211, and the intersection portion 522C intersects only with the power transmission coil 211.

In the example shown in FIG. 20, a total of three magnetic cores 50 are arranged on a straight portion of the power transmission coil 211, but the number of magnetic cores 50 to be arranged is not limited. In addition, some or all of the magnetic cores 50 may be arranged near the power receiving coil 311 instead of near the power transmission coil 211.

Although the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.
Therefore, countless modifications not exemplified are assumed within the scope of the technology disclosed in this specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.

10 AC power source, 21, 211 Power transmission coil, 30 Power receiving resonant circuit, 31, 311 Power receiving coil, 50, 50A to 50D, 501, 502A to 502C Magnetic core, 50C* Other magnetic core, 51, 511, 512C, 51A, 51C, 51C*, 61 Penetration portion, 52, 521, 522C, 52A, 52C, 52C*, 62 Intersection portion, 53, 531, 532C, 53A, 53C, 53C*, 63 Connection portion , 60, 60A-60D, 601, 602 Second magnetic core, 60a Opposing surface, 100, 200, 201, 300, 301, 400 Coil unit, 1000, 1001 Non-contact power supply system, 1100 Power transmission device, 1101 Power supply rack, 1200 Power receiving device, 1201, 1201A, 1201B Module device, L, L* Separation distance, L1 Distance, L2-L5, L2*, L3*, L3** Length

Claims (12)

A coil unit comprising: a power transmitting coil and a power receiving coil having parallel winding axes and spaced apart by a separation distance in a winding axis direction that is the direction of the winding axis; during power supply, the power transmitting coil and the power receiving coil are magnetically coupled to transmit AC power from the power transmitting coil to the power receiving coil; and a magnetic body that strengthens the magnetic coupling between the power transmitting coil and the power receiving coil during power supply, wherein when one of the power transmitting coil and the power receiving coil is designated as one coil and the other is designated as the other coil, the magnetic body is
a connection portion facing a part of the one coil in the winding axis direction;
a through portion that protrudes from the connection portion in the winding axis direction and penetrates an inside of the one coil;
an intersection portion protruding from the connection portion in the winding axis direction and sandwiching the part between the connection portion and the through portion,
A coil unit characterized in that, during power supply, the through portion passes through the one coil and the other coil, and the intersection portion intersects with the one coil and the other coil. The coil unit of claim 1, wherein the length of the through portion in the winding axis direction, excluding the thickness of the connection portion, is longer than the sum of the thickness of the one coil, the thickness of the other coil, and the separation distance when power is supplied. The coil unit according to claim 1 or 2, in which the direction perpendicular to the winding axis direction and in which the through-hole portion and the intersection portion face each other is defined as the facing direction, and the direction perpendicular to the winding axis direction and the facing direction is defined as the magnetic body extension direction, in a side view seen from the magnetic body extension direction, the length in the facing direction of the portion where the connection portion and one of the coils overlap in the facing direction is shorter than half the length of the one of the coils in the facing direction and half the length of the other of the coils in the facing direction. The coil unit according to any one of claims 1 to 3, wherein the other coil has an opposing surface that faces the magnetic body in the winding axis direction, and is provided with a second magnetic body that is adjacent to the through portion and the intersection portion when power is supplied. The coil unit according to any one of claims 1 to 4, comprising a plurality of the magnetic bodies. The other magnetic body is provided on the other coil, and the other magnetic body is
a second connection portion that faces a part of the second coil in the winding axis direction;
a second through portion that protrudes from the second connection portion in the winding axis direction and penetrates an inside of the second coil;
a second intersecting portion that protrudes from the second connection portion in the winding axis direction and has the part sandwiched between the second through-hole portion and the second intersecting portion,
6. The coil unit according to claim 1, wherein, during power supply, the other through portion passes through the other coil and the one coil, and the intersection portion intersects with the other coil and the one coil. The coil unit according to claim 4, comprising a plurality of the magnetic bodies and the second magnetic bodies. The coil further includes a second magnetic body on the other side, the second magnetic body being:
The coil unit according to claim 6 , further comprising an opposing surface that faces the other magnetic body in the winding axis direction, and that is adjacent to the other through-hole and the other intersection when power is supplied. The coil unit according to claim 7, wherein the number of the magnetic bodies is greater than the number of the second magnetic bodies. The coil unit according to claim 8, wherein the number of the other magnetic bodies is greater than the number of the other second magnetic bodies. A coil unit according to any one of claims 1 to 10,
a power transmitting side device to which the power transmitting coil is fixed and which supplies AC power to the power transmitting coil;
and a power receiving side device to which the power receiving coil is detachably provided. A coil structure having a magnetic body and a coil used for contactless power supply,
The magnetic body is
a connection portion facing a part of the coil in a winding axis direction, which is a direction of the winding axis of the coil;
a through portion protruding from the connection portion in the winding axis direction and penetrating an inside of the coil;
a crossing portion that protrudes from the connection portion in the winding axis direction and sandwiches the through portion and the part,
the coil is a power transmitting coil that is magnetically coupled to another coil separated from the other coil in the winding axis direction during power supply and transmits power between the other coil and the power transmitting coil via magnetic energy, or a power receiving coil to which the power is transmitted,
The magnetic body is a magnetic body that strengthens magnetic coupling between the coil and the other coil during the power supply,
A coil structure, characterized in that the through portion penetrates the inside of the coil and the other coil when power is supplied, and the intersection portion intersects with the coil and the other coil.

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