JP7357310B2 - Solenoid coil unit and non-contact power supply device - Google Patents

Description

The present disclosure relates to a contactless power supply device that non-contactly transmits power from a power supply side to a power reception side by magnetic field coupling, and a solenoid coil unit used in the contactless power supply device.

In recent years, contactless power supply devices that transmit power to electronic devices, electric mobility, etc. without using cables have been attracting attention. Specifically, an electric vehicle equipped with a power receiving unit can be charged contactlessly using a power supplying unit installed in a parking lot, or a power supplying unit installed on the road side can be charged while driving. This technology enables contactless charging.

The types of coil units used in non-contact power supply devices can be roughly divided into a circular type shown in FIG. 16(A) and a solenoid type shown in FIG. 16(B). As shown in FIG. 16A, the circular coil unit 100A has a configuration in which a coil 101A is concentrically wound on one side of a disk-shaped ferrite core 102A, and is also called a one-sided winding method. As shown in FIG. 16(B), the solenoid coil unit 100B has a configuration in which a coil 101B is wound around a flat ferrite core 102B, and is also called a double-sided winding method.

In either method, a decrease in power transmission efficiency not only increases loss but also causes heat generation, so increasing the transmission efficiency of a non-contact power supply device is an extremely important issue. It is known that in order to increase transmission efficiency, it is important to increase the coupling coefficient k between the power feeding side unit and the power receiving side unit and to increase the Q value of the coil.

Generally, although a circular coil unit has a high coupling coefficient k, it has a characteristic that it has a small tolerance for positional deviation between the power feeding side unit and the power receiving side unit. On the other hand, although the solenoid coil unit has a leakage magnetic flux on the back surface and has a slightly lower coupling coefficient, it is said to have a characteristic of having a large tolerance against positional deviation (Patent Document 1). The tolerance for misalignment between the power supply and power receiving units is called "robustness," and is a major issue in the social implementation of wireless power transfer.

Regarding contactless power supply technology for electric mobility such as hybrid cars and electric vehicles, it is believed that technology that enables power supply while driving will be necessary in the future. When assuming power supply while driving, it is necessary to ensure high robustness against both displacement in the front-rear movement direction of the mobility vehicle and displacement in the lateral direction, which is the direction of movement perpendicular to the front-rear movement direction. Desired.

FIG. 17 shows a graph showing the robustness of each of the solenoid type and circular type coil units using an H-shaped core, based on FIG. 4.2 of Non-Patent Document 1. Graphs Hx and Hy show changes in the coupling coefficient due to positional deviation in the x and y directions for the solenoid-type coil unit, respectively, and graph Cr shows changes in the coupling coefficient due to positional deviation in the circular-type coil unit. It shows. When the amount of positional deviation shown on the horizontal axis becomes large, the coupling coefficient of the circular coil unit rapidly decreases and power transmission becomes impossible. In the case of a solenoid coil unit using an H-shaped core, the robustness against positional deviation is higher than that of a circular coil unit due to the characteristics of the solenoid coil. However, due to the characteristics of the shape of the H-shaped core, the coupling coefficient may drop significantly depending on the direction and amount of misalignment, and it can be said that there is still room for improvement.

Furthermore, when considering contactless power supply to electric mobility, a gap of approximately 100 mm to 250 mm exists between the power supply side coil unit and the power reception side coil unit depending on the vehicle type. When specifically designing a coil unit that can accommodate this gap, there is a problem that conventional circular or solenoid type coil units are too heavy. In this regard, Patent Document 1 states that, for the purpose of reducing the weight of the coil unit, the width of the coiled part of the flat core where the coil is wound is narrower than the width of the magnetic pole part where the coil is not wound. A solenoid coil unit employing an H-shaped core is disclosed.

When the H-shaped core disclosed in Patent Document 1 is used, the solenoid coil unit can be made lighter than a conventional flat plate-shaped one. However, according to the details of the experimental conditions disclosed in Non-Patent Document 2, the gap between the coils is designed to be approximately 70 mm to 100 mm. In order to accommodate a gap of approximately 200 mm while maintaining power feeding performance, the solenoid coil unit may become larger, and as a result, further weight reduction will be required for practical use of the H-shaped core. there is a possibility. In fact, the weight of the coil units used in past demonstration experiments has ranged from several tens of kilograms to 100 kilograms, depending on the output, making it impractical to mount them on mobility vehicles.

Japanese Patent Application Publication No. 2011-50127

Jun Yamada Dissertation "Basic study of coil shape and resonant circuit system suitable for non-contact power supply during driving for electric vehicles" March 2018 Saitama University Graduate School of Science and Engineering Chiaki, Nagatsuka, Kaneko, Abe, Yasuda, Suzuki “Size and weight reduction of non-contact power transfer transformer for electric vehicles using new core structure” (SPC-11-048)

As described above, by using the solenoid coil unit that employs the H-shaped core disclosed in Patent Document 1, it is possible to achieve a certain degree of weight reduction and robustness. However, considering the full-scale social implementation of non-contact power transfer that is about to begin, and the selection of coil systems with an eye on power transfer while driving, it is difficult to say that we have reached a state that satisfies all aspects of coupling coefficient, robustness, and weight reduction. do not have.

The purpose of the present disclosure is to develop a solenoid coil unit that achieves all of "coupling coefficient", "robustness", and "lightweight" at a high level, and the solenoid coil unit, with the aim of full-scale social implementation of wireless power transfer. An object of the present invention is to provide a non-contact power supply device using the present invention.

A first form for solving the above problems is provided as a solenoid coil unit that exchanges power with other solenoid coil units in a non-contact manner. The solenoid coil unit of this form includes a solenoid coil installed in parallel with the other solenoid coil provided in the other solenoid coil unit at a predetermined distance in a separation direction perpendicular to the central axis direction; A rod-shaped core is wound around a solenoid coil and is longer than the length of the solenoid coil in the central axis direction. The rod-shaped core has a central portion around which the solenoid coil is wound, and end portions extending from both ends of the solenoid coil, and the ratio of the length to the width of the central portion is 2 or more. , the length of the solenoid coil in the central axis direction is approximately twice the separation distance.

In the second form, the ratio of the length to the width of the central portion may be 8 or more.

In the third form, when the length of the central portion is L and the width of the central portion is w, the relationship 2≦L/w≦16 may be satisfied.

In a fourth embodiment, the separation distance is 200 mm for another solenoid coil unit including the other solenoid coil having the same configuration as the solenoid coil and another rod-shaped core having the same configuration as the rod-shaped core. It is sufficient that the coupling coefficient k when installed without positional deviation across the substrate is 0.17 or more and less than 0.2.

In a fifth embodiment, the end portion may be provided with a plate-shaped additional magnetic pole portion that is thinner than the center portion and protrudes from the end portion.

In the sixth embodiment, the length of the additional magnetic pole portion may be greater than the width of the central portion.

In the seventh embodiment, the length and width of the additional magnetic pole portion may be approximately equal.

The eighth form is provided as a contactless power supply device. The non-contact power supply device of this embodiment includes a first solenoid coil unit that is the solenoid coil unit of any of the above embodiments, and a second solenoid coil unit that is the other solenoid coil unit. Mutual induction is generated between the first and second solenoid coil units to transmit and receive electric power.

According to the solenoid coil unit of the first embodiment, even if the separation distance between the solenoid coil unit and other solenoid coil units increases, the rod-shaped core can be configured to be elongated with a length corresponding to the separation distance, so that an increase in weight can be avoided. A high coupling coefficient can be obtained while suppressing In addition, if a solenoid coil unit is equipped with such an elongated rod-shaped core, it is possible to suppress a decrease in the coupling coefficient due to positional deviation more than when using a conventional disk-shaped core, flat plate core, H-shaped core, etc. High robustness can be achieved. Therefore, according to the solenoid coil unit of the first embodiment, it is possible to achieve all of the coupling coefficient, robustness, and weight reduction at a high level.

According to the solenoid coil unit of the second embodiment, since the rod-shaped core is configured to be more elongated, the coupling coefficient can be further increased while suppressing an increase in the weight of the solenoid coil unit. At the same time, high robustness can also be achieved.

According to the solenoid coil unit of the third embodiment, it is possible to prevent the weight from increasing significantly and to prevent the coupling coefficient with other solenoid coil units from becoming extremely low. Therefore, it is possible to achieve all of the coupling coefficient, robustness, and weight reduction at a higher level.

According to the solenoid coil unit of the fourth embodiment, it is possible to both suppress an increase in the weight of the solenoid coil unit and improve the coupling coefficient at an even higher level. Therefore, it is possible to achieve all of the coupling coefficient, robustness, and weight reduction at an even higher level.

According to the solenoid coil of the fifth embodiment, by providing the additional magnetic pole portion, the coupling coefficient can be increased even when the central portion of the rod-shaped core is downsized. Further, since the weight of the additional magnetic pole portion can be reduced by reducing the thickness, it is possible to effectively increase the coupling coefficient while suppressing an increase in the weight of the solenoid coil. Moreover, if the additional magnetic pole part is provided, it is possible to further suppress a decrease in the coupling coefficient due to positional deviation with respect to other solenoid coil units. Therefore, it is possible to achieve all of the coupling coefficient, robustness, and weight reduction at a higher level.

According to the solenoid coil of the sixth embodiment, since the additional magnetic pole portion is expanded in the width direction, an even higher coupling coefficient and robustness can be obtained.

According to the solenoid coil unit of the seventh embodiment, the additional magnetic pole portion is expanded in both the central axis direction and the width direction. Therefore, while increasing the coupling coefficient, it is possible to further improve the robustness against misalignment with respect to other solenoid coil units in both the central axis direction and the width direction.

According to the non-contact power supply device of the eighth embodiment, since it includes the solenoid coil unit of the above embodiment, it is possible to achieve a high level of coupling coefficient, robustness, and weight reduction.

FIG. 1 is a schematic front view, a schematic plan view, and a schematic side view of a solenoid coil unit according to a first embodiment. FIG. 1 is a schematic diagram showing the configuration of a non-contact power supply device using a solenoid coil unit according to a first embodiment. FIG. 3 is a schematic diagram for explaining magnetic flux generated in a pair of solenoid coil units. An explanatory diagram showing a graph regarding the length of a solenoid coil and a coupling coefficient. FIG. 2 is an explanatory diagram showing a graph representing the relationship between magnetic permeability and coupling coefficient. FIG. 3 is an explanatory diagram showing a graph representing the relationship between the cross-sectional area of a rod-shaped core and the coupling coefficient. FIG. 7 is an explanatory diagram showing a graph representing the relationship between the ratio of the coupling coefficient to the cross-sectional area of the rod-shaped core and the cross-sectional area of the rod-shaped core. A schematic front view, a schematic plan view, and a schematic side view of a solenoid coil unit according to a second embodiment. FIG. 7 is a schematic diagram showing the configuration of a non-contact power supply device using a solenoid coil unit according to a second embodiment. FIG. 7 is an explanatory diagram showing a graph representing the relationship between the dimensions of the additional magnetic pole portion and the coupling coefficient. FIG. 7 is an explanatory diagram showing a graph representing the relationship between the area of the additional magnetic pole portion and the coupling coefficient. An explanatory diagram showing a graph representing the relationship between separation distance and coupling coefficient. FIG. 3 is a schematic diagram showing a state in which a pair of solenoid coil units are misaligned in the width direction. FIG. 3 is a schematic diagram showing a state in which a pair of solenoid coil units are misaligned in the central axis direction. FIG. 3 is an explanatory diagram showing a graph representing the relationship between the amount of positional shift and the coupling coefficient. A schematic front view and a schematic plan view of a circular type and a solenoid type coil unit used in a conventional non-contact power supply device. FIG. 7 is an explanatory diagram showing a graph representing robustness in a conventional coil unit.

Hereinafter, embodiments of a solenoid coil unit and a non-contact power supply device of the present disclosure will be described in detail with reference to the drawings.

1. First embodiment:
FIG. 1 shows a schematic front view, a schematic plan view, and a schematic side view of a solenoid coil unit 50 according to a first embodiment. The solenoid coil unit 50 includes a solenoid coil 10.

In FIG. 1, the central axis CX of the solenoid coil 10 is shown by a chain line. Hereinafter, the direction along the central axis CX will also be simply referred to as the "central axis direction." FIG. 1 shows an arrow indicating the y direction corresponding to the central axis direction and an arrow indicating the x direction orthogonal to the y direction. The x direction corresponds to the "width direction" orthogonal to the central axis direction and the separation direction described later. In the following, regarding the dimensions of the solenoid coil unit, when we say "length" we mean the dimension in the y direction, when we say "width" we mean the dimension in the x direction, and when we say "thickness" we mean the dimension in the y direction. It means the dimension in the separation direction perpendicular to the x direction and the y direction.

The solenoid coil 10 is formed by tightly winding an insulated wire in a spiral shape, and generates a magnetic field in the direction of the central axis by passing a current through the wire. In order to reduce disturbance and leakage of magnetic flux as much as possible, it is desirable that the electric wire be wound evenly and regularly. The length of the solenoid coil 10 is L. In addition, in the figure, representation of each electric wire is omitted. The winding direction of the electric wire in the solenoid coil 10 is along the x direction.

The solenoid coil unit 50 further includes a rod-shaped core 20 around which the solenoid coil 10 is wound. The central axis of the rod-shaped core 20 corresponds to the central axis CX of the solenoid coil 10, and the y direction corresponds to the longitudinal direction of the rod-shaped core 20. The rod-shaped core 20 is made of, for example, a ferromagnetic material such as ferrite. The cross-sectional shape of the rod-shaped core 20 in a cross section perpendicular to the longitudinal direction is not particularly limited, and may be approximately square as shown in the figure, or may be a perfect circle or an ellipse. good.

The rod-shaped core 20 is made longer than the length L of the solenoid coil. The rod-shaped core 20 has a central portion 21 wound around the solenoid coil 10 and end portions 22 located at both ends of the rod-shaped core 20 and extending from both ends of the solenoid coil 10 . The length of the solenoid coil 10 matches the length L of the solenoid coil. Hereinafter, the length of the central portion 21 will also be expressed as "L". A pair of ends 22 of the rod-shaped core 20 function as magnetic poles of the solenoid coil unit 50.

Note that, as shown in FIG. 1, the thickness t of the rod-shaped core 20 is smaller than the length L of the central portion 21 and the width w of the rod-shaped core 20. The thickness of the rod-shaped core 20 is not particularly limited, and may be, for example, the width of the central portion 21 or more.

2 and 3 are schematic diagrams showing a state in which a pair of solenoid coil units 50, 50a are arranged in parallel with a predetermined distance G between them. In FIG. 3, the magnetic flux MF is illustrated by a dashed line. Further, in FIG. 3, electric wires forming the solenoid coil 10 are schematically illustrated.

The pair of solenoid coil units 50, 50a constitute a non-contact power supply device 55, and the solenoid coil unit 50 transfers power to and from another solenoid coil unit 50a arranged apart from each other in a non-contact manner. Hereinafter, the solenoid coil unit 50 of this embodiment will also be referred to as the "first solenoid coil unit 50", and the other solenoid coil unit 50a will also be referred to as the "second solenoid coil unit 50a".

In this embodiment, the second solenoid coil unit 50a has the same configuration as the first solenoid coil unit 50. The second solenoid coil unit 50a includes a solenoid coil 10 having the same configuration as the first solenoid coil unit 50 and a rod-shaped core 20, and has the same self-inductance as the first solenoid coil unit 50. be.

In the non-contact power supply device 55, the two solenoid coil units 50 and 50a are installed in parallel and spaced apart in the direction of separation. The "separation direction" here corresponds to the z direction perpendicular to the x direction and the y direction, and corresponds to the thickness direction of the rod-shaped core 20. In addition, in this specification, "parallel" means a state in which one straight line is along another straight line, and a state in which two straight lines are arranged mathematically strictly in "parallel"; This concept includes a state in which one straight line has an inclination angle of several degrees with respect to another straight line.

In the non-contact power supply device 55, the second solenoid coil unit 50a is installed with a separation distance G and no positional deviation. That is, in the non-contact power supply device 55, the first solenoid coil unit 50 is installed at a position overlapping the second solenoid coil unit 50a when viewed in the separation direction. With this arrangement, as shown in FIG. 3, part of the magnetic flux MF generated in one of the pair of solenoid coil units 50, 50a through which current is passed is transferred to the other solenoid. By passing through the rod-shaped core 20 of the solenoid coil 10 constituting the coil unit and returning to the one solenoid coil unit, mutual induction can be caused and electric power can be exchanged. In this specification, unless otherwise specified, the term "coupling coefficient" refers to two coils of the same configuration that are spaced apart in the direction of separation and arranged in parallel, as shown in FIGS. 2 and 3. This is the value when installed without any positional deviation.

FIG. 4 shows the relationship between the length L of the solenoid coil with respect to the separation distance G and the coupling coefficient k with respect to the length L when two solenoid coils having the same configuration are arranged in parallel with a separation distance G between them. This is a graph showing. In order to obtain the highest coupling coefficient k most efficiently, the inventor of the present invention investigated the relationship between the separation distance G between a pair of solenoid coils and the length L of the solenoid coils using experiments and simulations. The separation distance G is determined depending on the application of the non-contact power supply device 55, and here, assuming non-contact power supply to electric mobility, 200 mm is adopted as an example. In this case, as shown in FIG. 4, it is clear that the length L of the solenoid coil that can most efficiently obtain a high coupling coefficient k is approximately twice the separation distance G, that is, L≒2G. Ta. In an experimental example by the inventor of the present invention, the value of the coupling coefficient k was 0.088 when G = 200 mm and L = 400 mm.

If the solenoid coil unit is designed in the range of L<2G, it will be difficult to obtain a sufficient coupling coefficient k, and if the solenoid coil unit is designed in the range of L>2G, the solenoid coil unit will become larger than necessary and it will be difficult to reduce the weight. becomes. Note that the relationship shown in FIG. 4 is not limited to the case where the separation distance G is 200 mm. A similar relationship can be obtained even if the separation distance G is set to an arbitrary value within the range of 150 mm or more and 250 mm or less, or an arbitrary value within the range of 180 mm or more and 220 mm or less. Further, the value of L is not limited to one point of 2G, but a predetermined width is allowed depending on the purpose and design, and as an example, an error of about 10% is allowed. Therefore, the length L of the solenoid coil, which is approximately twice the separation distance G, is allowed to be set within the range of 1.8G to 2.2G. In this specification, the expression "L≈2G" means that L is any value within the range of 1.8G to 2.2G.

In this embodiment, the length L of the solenoid coil 10 is configured to satisfy the condition L≈2G. This makes it possible to design the rod-shaped core 20 into a shape that allows weight reduction while maintaining a high coupling coefficient k. Further, in the solenoid coil unit 50 of the present embodiment, the length L of the central portion 21 of the rod-shaped core 20 is designed to be at least twice the width w, that is, L≧2w. In this way, the rod-shaped core 20 can be made into an elongated shape with a small width w, so that the solenoid coil 10 can be adjusted so that the coupling coefficient k reaches a desired high value while suppressing an increase in the weight of the solenoid coil unit 50. The length L can be increased.

In the solenoid coil unit 50, the ratio of the length L of the central portion 21 in the central axis direction of the rod-shaped core 20 to the width w of the central portion 21 is preferably 3 times or more, and more preferably 4 times or more. . Further, the ratio of the length L of the central portion 21 to the width w of the central portion 21 may be 8 or more, that is, L≧8w. In this way, the solenoid coil unit 10 can be made into a more elongated rod-like shape, and the coupling coefficient k can be further increased while suppressing an increase in the weight of the solenoid coil unit 10.

Note that from the perspective of weight reduction only, the thinner the rod core is, the more effective it is, but in reality, it is necessary to take into account mechanical strength, specifications of the insulated wire to be wound, and ensuring a cross-sectional area that is sufficient to avoid saturation of magnetic flux density. It is preferable that the maximum value of L/w is determined.

FIG. 5 shows a graph showing the coupling coefficient k when the magnetic permeability of the rod-shaped core 20 is changed in the non-contact power supply device 55. In order to obtain a high coupling coefficient k, the rod-shaped core 20 is preferably made of a material with a magnetic permeability of 1500 H/m or more, and more preferably made of a material with a magnetic permeability of 2000 H/m or more. More preferably, the rod-shaped core 20 is made of a material having a magnetic permeability of 2500 H/m or more. Furthermore, even if the rod-shaped core 20 is made of a material with a magnetic permeability greater than 3000 H/m, it is not expected that the coupling coefficient k will become significantly high. Therefore, it is preferable that the rod-shaped core 20 is made of a material having a magnetic permeability of 3000 H/m or less.

FIG. 6 shows a graph showing the relationship between the cross-sectional area S of the rod-shaped core 20 and the coupling coefficient k in the non-contact power supply device 55. FIG. 7 shows a graph showing the relationship between the ratio k/S of the coupling coefficient k to the cross-sectional area S of the rod-shaped core 20 and the cross-sectional area S. The graphs in FIGS. 6 and 7 were independently obtained by the inventor of the present application through repeated research. The coupling coefficient k in the graphs of FIGS. 6 and 7 is a value when the separation distance G between the two solenoid coil units 10 and 10a is 200 mm. Furthermore, in the graphs of FIGS. 6 and 7, the region where the cross-sectional area S is greater than or equal to s1 and less than s2 corresponds to the region where the coupling coefficient k is greater than or equal to 1.7 and less than 2.0.

The cross-sectional area S of the rod-shaped core 20 corresponds to the cross-sectional area of the central portion 21 in a cross section perpendicular to the central axis direction. As shown in FIG. 6, the larger the cross-sectional area S of the rod-shaped core 20, the higher the coupling coefficient k can be. However, increasing the cross-sectional area S leads to an increase in the size of the rod-shaped core 20, which leads to an increase in the weight of the solenoid coil unit 50.

Here, as shown in FIGS. 6 and 7, in a region where the coupling coefficient k is 0.2 or more, even if the cross-sectional area S is increased, the coupling coefficient k does not increase much. If the cross-sectional area S is increased so that the coupling coefficient k becomes larger than 0.2, the weight of the rod-shaped core 20 may increase significantly, which is not preferable. Therefore, in the solenoid coil unit 50, the value of the coupling coefficient k per weight of the solenoid coil unit 50 can be increased by designing the rod-shaped core 20 with a cross-sectional area S such that the coupling coefficient k is less than 0.2. , it becomes possible to obtain higher power supply performance with lighter weight.

Further, as shown in FIGS. 6 and 7, in a region where the coupling coefficient k is less than 0.17, the amount of decrease in the coupling coefficient k relative to the amount of decrease in the cross-sectional area S becomes significantly large. Therefore, if the cross-sectional area S is such that the coupling coefficient k is less than 0.17, even if the weight of the solenoid coil unit 50 can be reduced, there is a high possibility that the power supply performance will deteriorate significantly. Therefore, in the solenoid coil unit 50, it is preferable to design the rod-shaped core 20 with a cross-sectional area S such that the coupling coefficient k is 0.17 or more.

Thus, in the solenoid coil unit 50, it is preferable to design the rod-shaped core 20 so that the coupling coefficient k is 0.17 or more and less than 0.2. The higher the coupling coefficient k is, the more preferable it is. Therefore, in the solenoid coil unit 50, it is more preferable to design the rod-shaped core 20 so that the coupling coefficient k is 0.175 or more. It is further preferred to design a rod-shaped core 20. It is even more preferable to design the solenoid coil unit 50 so that the coupling coefficient k is 0.19 or more.

In addition, the inventor of the present invention found from the graphs in FIGS. 6 and 7 that in the rod-shaped core 20, the ratio L/w of the length L to the width w of the central portion 21 is 2≦L/w≦16. We have found that it is preferable to satisfy the following criteria. If this relationship is satisfied, it is possible to prevent the cross-sectional area S of the rod-shaped core 20 from becoming too small and the coupling coefficient k from becoming an extremely low value. In addition, it is possible to prevent the cross-sectional area S of the rod-shaped core 20 from becoming too large and the weight of the solenoid coil unit 50 from becoming extremely large.

In this embodiment, since the solenoid coil 10 of the solenoid coil unit 50 is of a solenoid type, it is more robust during non-contact power supply than a conventional circular type coil unit as shown in FIG. 16(A). Highly sexual. In addition, the solenoid coil unit 50 has a longer length in the central axis direction than a conventional solenoid type coil unit, so the position in the central axis direction during non-contact power supply is longer than that of a conventional solenoid type coil unit. Increased robustness against misalignment.

As described above, according to the solenoid coil unit 50 of the present embodiment and the non-contact power supply device 55 including the solenoid coil unit 50, it is possible to achieve all of the coupling coefficient, robustness, and weight reduction at a high level. It is.

2. Second embodiment:
FIG. 8 shows a schematic front view, a schematic plan view, and a schematic side view of a solenoid coil unit 50A according to the second embodiment. The configuration of the solenoid coil unit 50A of the second embodiment is the same as that of the solenoid coil unit 50 described in the first embodiment, except that an additional magnetic pole portion 30 is provided at each of the two ends 22 of the rod-shaped core 20. Almost the same.

The additional magnetic pole portion 30 is configured as a plate-shaped portion that protrudes from the end portion 22 of the rod-shaped core 20 and is thinner than the central portion 21 . In the second embodiment, the additional magnetic pole sections 30 at each end 22 have the same shape. In the second embodiment, the additional magnetic pole portion 30 has a substantially square shape when viewed in the thickness direction, and protrudes from the end portion 22 along the x direction and the y direction. As shown in FIG. 8, in the second embodiment, the end portion 22 is located at the center of the additional magnetic pole portion 22 in the x direction, and the end portion 22 is configured such that its thickness decreases as it moves away from the center portion 21. .

The thickness c of the additional magnetic pole portion 30 is constant. From the viewpoint of reducing the weight of the solenoid coil unit 50A, it is preferable that the thickness c of the additional magnetic pole portion 30 is as small as possible. The thickness c of the additional magnetic pole portion 30 is preferably 1/2 or less, and more preferably 1/3 or less, of the thickness t of the central portion 21. It is more preferable that the thickness c of the additional magnetic pole part 30 is 1/5 or less of the thickness t of the central part 21. Note that in other embodiments, the thickness c of the additional magnetic pole portion 30 may not be constant. The additional magnetic pole part 30 may have a configuration in which the thickness changes continuously in the width direction or the length direction, for example. In this case, the above-mentioned thickness c may be the maximum thickness of the additional magnetic pole portion 30.

In the second embodiment, the additional magnetic pole section 30 is made of the same magnetic material as the rod-shaped core 20 and is produced integrally with the rod-shaped core 20. In other embodiments, the additional magnetic pole section 30 may be configured separately from the rod-shaped core 20 and may be retrofitted to the end portion 22 by joining. Furthermore, the additional magnetic pole section 30 may be made of a different type of magnetic material from the rod-shaped core 20.

As will be described later, by including the additional magnetic pole portion 30, the solenoid coil unit 50A has the effect of increasing the coupling coefficient k while suppressing an increase in weight, and increasing the robustness against positional displacement. It is possible.

Note that the shape of the plate surface of the additional magnetic pole section 30 is not limited to a substantially rectangular shape. In other embodiments, the shape of the plate surface of the additional magnetic pole section 30 may be, for example, a triangular shape, a polygonal shape, a perfect circular shape, or an elliptical shape. Further, the shape of the plate surface of the additional magnetic pole section 30 may be different between one end 22 and the other end 22. In the second embodiment, the additional magnetic pole portion 30 protrudes from the end portion 22 in the width direction, and the width b of the additional magnetic pole portion 30 is larger than the width w of the end portion 22 of the rod-shaped core 20. On the other hand, in other embodiments, the additional magnetic pole portion 30 may not extend from the end portion 22 in the width direction, but may extend only in the central axis direction. Further, the additional magnetic pole portion 30 does not need to protrude from the end portion 22 in the central axis direction, and may protrude only in the width direction.

FIG. 9 is a schematic diagram showing a non-contact power supply device 55A using a solenoid coil unit 50A of the second embodiment. The contactless power supply device 55A includes a first solenoid coil unit 50A and a second solenoid coil unit 50Aa. The second solenoid coil unit 50Aa has the same configuration as the first solenoid coil unit 50A, and includes a solenoid coil 10 and a rod-shaped core 20 provided with an additional magnetic pole portion 30. The second solenoid coil unit 50Aa has the same self-inductance as the first solenoid coil unit 50A. Further, the dimensions of the additional magnetic pole portion 30 are also the same.

In the non-contact power supply device 55A, the first solenoid coil unit 50A is separated by a predetermined distance G in the separating direction from the second solenoid coil unit 50Aa, which is another solenoid coil unit that performs non-contact power supply by mutual induction. are installed in parallel across the The separation direction is a direction along the z direction, similar to the first embodiment. In the contactless power supply device 55A, similarly to the contactless power supply device 55 of the first embodiment, the pair of solenoid coil units 50A and 50Aa are installed without being displaced from each other. In this arrangement, the additional magnetic pole part 30 of the first solenoid coil unit 50A and the additional magnetic pole part 30 of the second solenoid coil unit 50Aa are arranged in parallel so that their plate surfaces face each other in the direction of separation. Ru.

FIG. 10 shows a graph showing the relationship between the dimensions of the additional magnetic pole portion 30 and the coupling coefficient k. FIG. 11 shows a graph showing the relationship between the area PS of the additional magnetic pole section 30 and the coupling coefficient k. 10 and 11 were obtained through experiments by the inventor of the present invention.

The coupling coefficient k in this experiment is a value obtained between a pair of solenoid coil units 50A and 50Aa having the same configuration as shown in FIG. In this experiment, the additional magnetic pole section 30 was configured to have a substantially square plate surface with equal length a and width b. The dimensions of the additional magnetic pole part 30 in FIG. 10 correspond to the width b of the additional magnetic pole part 30. The area PS of the additional magnetic pole part 30 in FIG. 11 includes the area of the side surface of the end part 22, and corresponds to a value obtained by multiplying the length a and the width b of the additional magnetic pole part 30. That is, PS=a×b.

The graph of FIG. 10 shows that the coupling coefficient k increases as the additional magnetic pole portion 30 protrudes from the end portion 22, as indicated by the solid line. Moreover, the graph of FIG. 11 shows that the larger the area of the additional magnetic pole part 30, the larger the coupling coefficient k becomes.

Here, the magnetic resistance R in the magnetic circuit consisting of the two solenoid coil units 50A and 50Aa is expressed by the following equation 1. As shown in Equation 1, the larger the area PS of the additional magnetic pole part 30 is, the smaller the magnetic resistance R becomes, and the larger the magnetic flux becomes. From this, it is clear that if the dimensions a and b of the additional magnetic pole portion 30 are increased and the area PS thereof is increased, the coupling coefficient k will be increased.

In the case of the additional magnetic pole part 30, by increasing its dimensions, it is easier to increase the coupling coefficient k than by increasing the length L and cross-sectional area S of the central part 21 of the rod-shaped core 20. Moreover, since the additional magnetic pole part 30 is plate-shaped, it is easy to make it lightweight by adjusting the thickness c. Therefore, in the solenoid coil unit 50A of the second embodiment, even if the length L and cross-sectional area S of the central portion 21 of the rod-shaped core 20 are reduced to reduce the weight, the provision of the additional magnetic pole portion 30 makes it possible to maintain the coupling. It becomes possible to increase the coefficient k. In other words, with the solenoid coil unit 50A of the second embodiment, it is possible to increase the coupling coefficient k even more easily while suppressing an increase in weight.

FIG. 12 shows a graph showing an example of the relationship between the separation distance G between coil units and the coupling coefficient k in a non-contact power supply device using conventional coil units. A first graph GP shown by a dashed line shows an example of the relationship between the separation distance G and the coupling coefficient k obtained in the conventional circular coil unit 100A shown in FIG. 16(A). The second graph GS shown by the two-dot chain line shows an example of the relationship between the separation distance G and the coupling coefficient k obtained in the conventional solenoid coil unit 100B having the flat ferrite core 102B shown in FIG. 16(B). ing. When performing contactless power supply using the conventional coil units 100A and 100B, the separation distance G and the coupling coefficient k generally have a so-called trade-off relationship, and as the separation distance G increases, the coupling coefficient k increases. There is a declining relationship.

Here, the hatched area RA around the two graphs GP and GS indicates the approximate range of power supply performance achieved by the conventional technology. Hereinafter, the area RA will also be referred to as the "reference area RA." In FIG. 12, when the coupling coefficient k is plotted in the upper right region of the reference region RA, it can be said that the contactless power supply device has a configuration that exhibits power supply performance with higher efficiency than the conventional one. Conversely, if the coupling coefficient k is plotted in the lower left area of the reference area RA, it can be said that the contactless power supply device has a configuration that exhibits power supply performance with lower efficiency than the conventional one.

See Table 1 below. As an example of the second embodiment, the inventor of the present invention proposed that in the configuration of the solenoid coil unit 50A shown in FIG. Manufacturing example E of a solenoid coil unit 50A was produced.

The inventor of the present invention constructed a non-contact power supply device 55A shown in FIG. 9 using Manufacturing Example E, and determined the coupling coefficient k when the separation distance G was 200 mm. The results are plotted as points PI in FIG. In this example, the value of the coupling coefficient k is 0.175, and it can be seen that the power supply performance is more efficient and higher than that of the conventional example.

In this way, with the configuration of the solenoid coil unit 50A of the second embodiment, by providing the additional magnetic pole portion 30, it is possible to further increase the coupling coefficient k while suppressing an increase in weight. According to the solenoid coil unit 50A of the second embodiment, the separation distance G is not limited to 200 mm, but also when the separation distance G is set to any value within the range of 150 mm or more and 250 mm or less, or 180 mm. Even if it is set to an arbitrary value within the range of 220 mm or less, the coupling coefficient k can be set to 0.18 or more or 0.2 or more.

Next, the weight of Production Example E above was compared with that of a conventional solenoid coil unit using a flat core and an H-shaped core. The results are shown in Table 2 below. The solenoid coil unit of the comparative example showed a coupling coefficient k equivalent to that of Production Example E when the separation distance G was as short as 70 mm to 100 mm. In other words, Manufacturing Example E was lighter than the Comparative Example and exhibited higher power feeding performance than the Comparative Example. In addition, in the solenoid coil unit of the comparative example, if you try to achieve the same coupling coefficient k by setting the separation distance G to 200 mm, the length of the coil or core may need to be twice as long, and the area may need to be about 4 times as large. Yes, the weight will increase accordingly.

As can be seen from Table 2, compared to the conventional solenoid coil unit using a flat core or an H-shaped core, the solenoid coil unit 50A of the second embodiment can significantly reduce weight while improving power supply performance. This makes it practical to install it in electric mobility, etc.

The robustness of the solenoid coil unit 50A will be described with reference to FIGS. 13 and 14. FIG. 13 schematically shows an arrangement state in which a pair of solenoid coil units 50A and 50Aa constituting a non-contact power supply device 55A are shifted by a distance Dx in the x direction. FIG. 14 schematically shows an arrangement state in which the pair of solenoid coil units 50A and 50Aa are shifted by a distance Dy in the y direction.

With the non-contact power supply device 55A using the solenoid coil unit 50A of the second embodiment, even if a positional deviation occurs, the coupling coefficient k due to the positional deviation is increased by the additional magnetic pole portion 30. decrease is suppressed. Therefore, high robustness against misalignment between the pair of solenoid coil units 50A and 50Aa can be achieved.

In the solenoid coil unit 50A, the width b of the additional magnetic pole portion 30 is preferably larger than the width w of the central portion 21. Thereby, the robustness against misalignment in the width direction can be increased by the amount that the additional magnetic pole section 30 protrudes in the width direction. Further, in the solenoid coil unit 50A, it is desirable that the additional magnetic pole portion 30 has the same length a and width b. This makes it possible to increase robustness against misalignment both in the central axis direction and in the width direction.

Below, the results of an experiment conducted by the inventor of the present invention regarding the robustness of the non-contact power supply device 55A against positional displacement will be explained. In this experiment, a non-contact power supply device 55A was constructed using Manufacturing Example E described above with a separation distance G of 200 mm, and non-contact power supply was performed with a shift of 150 mm in each of the x direction and the y direction.

Here, in general, the inductance L is expressed by Equation 2. When a positional shift occurs as shown in FIGS. 13 and 14, the inductance L decreases due to a decrease in the area S where the magnetic poles overlap in the direction of separation and an increase in the magnetic path length l. In this experimental example, since the capacitance C of the capacitor used in the electric circuit is constant, resonance is maintained by increasing the resonant frequency f by the amount that the inductance L decreases based on Equation 3. .

Table 3 shows the results of the experiment. If a positional shift of 150 mm occurs in the width direction, the efficiency of 92.5% decreases to 85.0%, but by adjusting the supply frequency as described above, the efficiency can be increased to 91.6%. It turns out it's possible. Furthermore, if a positional deviation of 150 mm occurs in the central axis direction, the efficiency of 92.2% will drop to 81.9%, but by adjusting the supply frequency in the same way, the efficiency can be increased to 91.0%. was found to be possible.

FIG. 15 is a graph showing changes in the coupling coefficient k when the position is shifted in the x direction, which is the width direction, and the y direction, which is the central axis direction. The horizontal axis of FIG. 15 shows the amount of positional deviation [mm], and the vertical axis shows the coupling coefficient k/k ₀ normalized to 1.0 in a state where there is no positional deviation.

Graphs Gx and Gy are obtained in the non-contact power supply device 55A using Manufacturing Example E described above. Graph Gx is a graph when the position is shifted in the x direction, and graph Gy is a graph when the position is shifted in the y direction.

Graphs C1 to C3 of the comparative example are graphs based on the coupling coefficients disclosed in Non-Patent Document 1. Graph C1 of the comparative example shows a case where a positional shift in the x direction is caused in a configuration using an H-shaped core. Graph C2 of the comparative example shows a case where a positional shift in the y direction is caused in a configuration using an H-shaped core. Graph C3 of the comparative example shows a case where positional deviation occurs in a configuration using a circular coil unit. Note that the circular positional shift has no directional dependence in the x direction and the y direction.

According to FIG. 15, when manufacturing example E of the solenoid coil unit 50A is used, even when the amount of positional deviation reaches 300 mm, the positional deviation in the y-direction is 45% or more relative to the positional deviation in the x-direction, and the positional deviation in the y-direction is This shows that power can be transferred while the coupling coefficient k is maintained at 20% or more. On the other hand, in all of the graphs C1 to C3 of the comparative example, it can be seen that the coupling coefficient k decreases rapidly as the amount of positional deviation increases. In the graph C1 of the comparative example, the coupling coefficient k becomes almost zero when the displacement amount is 300 mm, and in the graphs C2 and C3 of the comparative example, the coupling coefficient k becomes smaller than zero already when the displacement amount reaches 100 mm. There are dead spots where power cannot be transferred.

As a result of evaluating the influence of positional deviation on power transmission efficiency, it was confirmed that the structure had high robustness in both the x and y directions. This will further expand the applications of contactless power transfer technology, and make it more realistic to provide power while driving to electric mobility vehicles.

As described above, according to the solenoid coil unit 50A of the second embodiment and the non-contact power supply device 55A using the same, since the additional magnetic pole section 30 is provided, the coupling coefficient can be improved at an even higher level. Both robustness and weight reduction can be achieved.

3. summary:
As shown in Table 4, conventional circular-type coil units, solenoid-type coil units with a flat core, and solenoid-type coil units with an H-shaped core have all the advantages of coupling coefficient, robustness, and weight reduction. It does not even meet the standards. On the other hand, according to the solenoid coil units 50 and 50A of the first embodiment and the second embodiment, as described above, all of the coupling coefficient, robustness, and weight reduction can be achieved at a high level. Further, in conventional circular coil units and solenoid type coil units having a flat core, dead spots occur when positional deviation becomes large. In a solenoid type coil unit having an H-shaped core, dead spots may occur depending on the direction of positional deviation. On the other hand, according to the solenoid coil units 50 and 50A of the first embodiment and the second embodiment, generation of dead spots due to positional deviation can be suppressed more than such conventional solenoid coil units.

Although preferred embodiments and examples of the present invention have been described above, the present invention is not limited to such embodiments and examples. Various changes and modifications can be made to the configuration disclosed in this application within the scope of the technical idea of the invention of this application. For example, the solenoid coil units 50 and 50A of the first embodiment and the second embodiment described above may be used for contactless power supply between other coil units having different configurations.

10 Solenoid coil 20 Rod-shaped core 21 Center part 22 End part 30 Additional magnetic pole part 50, 50a, 50A, 50Aa Solenoid coil unit 55, 55A Non-contact power supply device 100A, 100B Coil unit 101A Circular coil 101B Solenoid coil 102A Disc-shaped Ferrite core 102B Flat ferrite core CX Central axis MF Magnetic flux

Claims (3)

A solenoid coil unit that exchanges power without contact with other solenoid coil units,
a solenoid coil installed in parallel with another solenoid coil included in the other solenoid coil unit at a predetermined distance in a separation direction perpendicular to the central axis direction;
a rod-shaped core around which the solenoid coil is wound and which is longer than the length of the solenoid coil in the central axis direction;
Equipped with
The rod-shaped core has a central portion around which the solenoid coil is wound, and end portions extending from both ends of the solenoid coil,
The ratio of the length to the width of the central portion is 2 or more,
The length of the solenoid coil in the central axis direction is 1.8 or more and 2.2 or less of the separation distance,
The end portion is provided with a plate-shaped additional magnetic pole portion that is thinner than the center portion and protrudes from the end portion ,
The length and width of the additional magnetic pole portion are equal;
A solenoid coil unit characterized by: The solenoid coil unit according to claim 1, wherein the width of the additional magnetic pole portion is larger than the width of the central portion. A first solenoid coil unit which is the solenoid coil unit according to claim 1 or 2 ;
a second solenoid coil unit that is the other solenoid coil unit;
Equipped with
A non-contact power supply device that generates mutual induction between the first and second solenoid coil units to transmit and receive power.