Contactless power supply device

Abstract

To provide a contactless power supply capable of suppressing reduction in the effect of a magnetic body.SOLUTION: In a contactless power supply that supplies power from a power transmission coil to a power reception coil without contact, the power receiving coil includes a first magnetic body that is formed by winding a wire so as to surround the winding axis and arranged on the opposite side to the power transmission coil with respect to the power reception coil so as to intersect the winding axis, and a second magnetic body that is arranged without contact with the power reception coil and the first magnetic body, and arranged with respect to the power reception coil outside a position half the coil width between the inner circumference and the outer circumference of the power reception coil in a direction orthogonal to the winding axis.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a contactless power supply device. [Background technology]

[0002] Patent Document 1 discloses a technology in which, in a contactless power supply device, the transmitting coil and the receiving coil are spiral coils, the receiving coil is attached directly or indirectly to a metal member, a non-conductive magnetic thin film is formed on the surface of the metal member in a certain range centered on the attachment position of the receiving coil, and the shape of the non-conductive magnetic thin film is the same as the shape of the transmitting coil extended in the vehicle width direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-076653 Summary of the Invention [Problem to be solved by the invention]

[0004] If a magnetic thin film is placed on the back surface of the coil so as to cover the coil, the magnetic flux density increases and the effect of the magnetic material decreases.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a contactless power supply device that can prevent the effect of a magnetic body from being reduced. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the contactless power supply device of the present invention is a contactless power supply device that supplies power contactlessly from a transmitting coil to a receiving coil, wherein the receiving coil is formed by winding a wire around a winding axis, and is characterized by comprising: a first magnetic body that is arranged on the opposite side of the receiving coil from the transmitting coil so as to intersect with the winding axis; and a second magnetic body that is arranged in a non-contact manner with the receiving coil and the first magnetic body, and is arranged with respect to the receiving coil outside a position half the coil width between the inner and outer circumferences of the receiving coil in a direction perpendicular to the winding axis.

[0007] This allows the transmission efficiency between the coils to be improved compared to when the second magnetic body is not present, while reducing the magnetic flux density of the second magnetic body, thereby preventing the effect of the magnetic body from being reduced.

[0008] In the above configuration, the second magnetic body may be disposed on the opposite side of the first magnetic body from the power receiving coil side.

[0009] This makes it possible to prevent the effect of the magnetic body from being reduced in a configuration in which the second magnetic body is disposed on the opposite side of the first magnetic body from the power receiving coil side.

[0010] In the above configuration, the second magnetic body may be disposed on the opposite side of the power receiving coil from the first magnetic body side.

[0011] This makes it possible to prevent the effect of the magnetic body from being reduced in a configuration in which the second magnetic body is disposed on the opposite side of the power receiving coil from the first magnetic body side.

[0012] In addition, in the above, an intermediate magnetic body may be provided which extends in the same direction as the winding axis, has one end in contact with or not in contact with the first magnetic body, and has the other end in contact with the second magnetic body.

[0013] This allows the maximum magnetic flux density of the second magnetic body to be reduced more than when there is no relay magnetic body.

[0014] In the above, an extension portion may be provided that extends from the other end of the relay magnetic body along the second magnetic body in a direction perpendicular to the winding axis.

[0015] This improves the transmission efficiency between the coils and reduces the maximum magnetic flux density of the second magnetic body compared to when there is no elongated portion. [Effects of the Invention]

[0016] The contactless power supply device according to the present invention has an advantage that it is possible to prevent the effect of the magnetic body from being reduced. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a contactless power supply device according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing a contactless power receiving device and a contactless power transmitting device. [Figure 3] Fig. 3(a) is a bottom view of the power receiving coil, and Fig. 3(b) is a top view of the power receiving coil. [Figure 4] Fig. 4(a) shows a case where the second magnetic body is arranged with an overlap rate of 100% with respect to the receiving coil, Fig. 4(b) shows a case where the second magnetic body is arranged with an overlap rate of 50% with respect to the receiving coil, and Fig. 4(c) shows a case where the second magnetic body is arranged with an overlap rate of 0% with respect to the receiving coil. [Figure 5] FIG. 5 is a graph showing the relationship between the overlap rate of the second magnetic body with respect to the power receiving coil and the transmission efficiency between the coils. [Figure 6] FIG. 6 is a graph showing the relationship between the overlap ratio of the second magnetic body with respect to the power receiving coil and the maximum magnetic flux density of the second magnetic body. [Figure 7] FIG. 7 is a diagram showing a contactless power receiving device and a contactless power transmitting device according to the second embodiment. [Figure 8] FIG. 8 is a diagram for explaining the positional relationship between the end of the power receiving coil and the end of the second magnetic body. [Figure 9] FIG. 9 is a graph showing the relationship between the end position of the second magnetic body and the magnetic flux density. [Figure 10] FIG. 10 is a graph showing the relationship between the end position of the second magnetic body and the transmission efficiency. [Figure 11] FIG. 11 is a diagram showing a case where a relay magnetic body is provided between the first magnetic body and the second magnetic body. [Figure 12] FIG. 12 is a graph showing the relationship between the presence or absence of relay magnetic bodies and the transmission efficiency between coils. [Figure 13] FIG. 13 is a graph showing the relationship between the presence or absence of relay magnetic bodies and the maximum magnetic flux density of the second magnetic bodies. [Figure 14] FIG. 14 is a diagram for explaining the positional relationship between the end of the power receiving coil, the end of the second magnetic body, and the end of the relay magnetic body. [Figure 15] FIG. 15 is a graph showing the relationship between the end position of the second magnetic body and the transmission efficiency between the coils. [Figure 16] FIG. 16 is a graph showing the relationship between the end position of the second magnetic body and the maximum magnetic flux density of the second magnetic body. [Figure 17] FIG. 17 is a diagram showing a case where the relay magnetic body is extended along the second magnetic body. [Figure 18] Fig. 18(a) shows the case where the extension amount of the extension portion along the second magnetic body in the radial direction is 0 [mm], Fig. 18(b) shows the case where the extension amount of the extension portion along the second magnetic body in the radial direction is 20 [mm], and Fig. 18(c) shows the case where the extension amount of the extension portion along the second magnetic body in the radial direction is 40 [mm]. [Figure 19] FIG. 19 is a graph showing the relationship between the extension amount along the second magnetic body of the extension portion in the radial direction and the transmission efficiency between the coils. [Figure 20]FIG. 20 is a graph showing the relationship between the extension amount of the extension portion along the second magnetic body in the radial direction and the maximum magnetic flux density of the second magnetic body. [Figure 21] Fig. 21(a) is a diagram showing a case where the overlap amount of the extension portion with respect to the second magnetic body is 0 [mm]. Fig. 21(b) is a diagram showing a case where the overlap amount of the extension portion with respect to the second magnetic body is 20 [mm]. Fig. 21(c) is a diagram showing a case where the overlap amount of the extension portion with respect to the second magnetic body is 40 [mm]. Fig. 21(d) is a diagram showing a case where the overlap amount of the extension portion with respect to the second magnetic body is 60 [mm]. Fig. 21(e) is a diagram showing a case where the overlap amount of the extension portion with respect to the second magnetic body is 80 [mm]. [Figure 22] FIG. 22 is a graph showing the relationship between the overlap amount of the extension portion with respect to the second magnetic body and the maximum magnetic flux density of the second magnetic body. [Figure 23] FIG. 23 is a graph showing the relationship between the overlap amount of the extension portion with respect to the second magnetic body and the transmission efficiency between the coils. [Figure 24] Fig. 24(a) is a diagram showing a case where second magnetic bodies are provided corresponding to two opposing sides of a first magnetic body. Fig. 24(b) is a diagram showing a case where second magnetic bodies are provided corresponding to four sides of the first magnetic body. Fig. 24(c) is a diagram showing a case where second magnetic bodies, each longer than the sides of the first magnetic body, are provided corresponding to two opposing sides of the first magnetic body. Fig. 24(d) is a diagram showing a case where second magnetic bodies are provided to surround the periphery of the first magnetic body. [Figure 25] Fig. 25(a) is a diagram showing the case where the mouth-shaped second magnetic body is provided at 50[%] elongation, Fig. 25(b) is a diagram showing the case where the mouth-shaped second magnetic body is provided at 100[%] elongation, and Fig. 25(c) is a diagram showing the case where the mouth-shaped second magnetic body is provided at 200[%] elongation. [Figure 26] Fig. 26(a) shows a case where the second magnetic body is elongated by 50%. Fig. 26(b) shows a case where the second magnetic body is elongated by 100%. Fig. 26(c) shows a case where the second magnetic body is elongated by 200%. [Figure 27] Fig. 27(a) shows the case where the I-shaped second magnetic body is provided at 50[%] elongation, Fig. 27(b) shows the case where the I-shaped second magnetic body is provided at 100[%] elongation, and Fig. 27(c) shows the case where the I-shaped second magnetic body is provided at 200[%] elongation. [Figure 28] Figure 28(a) shows the case where the second magnetic body of the mold is provided at 50[%] elongation, Figure 28(b) shows the case where the second magnetic body of the mold is provided at 100[%] elongation, and Figure 28(c) shows the case where the second magnetic body of the mold is provided at 200[%] elongation. [Figure 29] FIG. 29 is a diagram showing some of the conditions for misalignment of the power receiving coil unit with respect to the power transmitting coil. [Figure 30] FIG. 30 is a graph showing the relationship between the elongation rate of the second magnetic body and the average transmission efficiency. [Figure 31] FIG. 31 is a graph showing the relationship between the area of the second magnetic body and the average transmission efficiency. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Embodiment 1) A first embodiment of a contactless power supply device according to the present invention will be described below, but the present invention is not limited to this embodiment.

[0019] FIG. 1 is a diagram showing a schematic configuration of a contactless power supply device 10 according to a first embodiment. The contactless power supply device 10 according to the first embodiment is configured by a contactless power receiving device 4 having a power receiving coil 41 as a vehicle-side coil provided in a vehicle 1 equipped with a motor generator 2 and a battery 3, and a plurality of contactless power transmitting devices 5 having power transmitting coils 51 as ground-side coils installed on a road 6, which is a road on which the vehicle 1 can travel, along the vehicle's traveling direction. Note that well-known configurations can be adopted as the basic configurations of the contactless power receiving device 4 and the contactless power transmitting device 5. The contactless power receiving device 4 can contactlessly receive power transmitted (supplied) from a power transmitting coil 52 of the contactless power transmitting device 5 having the power transmitting coil 51, by using the power receiving coil 41. The power received by the contactless power receiving device 4 from the contactless power transmitting device 5 is supplied to the motor generator 2 and the battery 3.

[0020] Figure 2 is , non 3A and 3B are diagrams showing a contact power receiving device 4 and a contactless power transmitting device 5. Fig. 3(a) is a diagram showing a bottom view of a power receiving coil 41. Fig. 3(b) is a diagram showing a top view of the power receiving coil 41.

[0021] 2, 3(a) and 3(b), the non-contact power receiving device 4 includes a wound power receiving coil 41, a first magnetic body 42, and a second magnetic body 43. In this embodiment, at least the power receiving coil 41, the first magnetic body 42, and the second magnetic body 43 form a power receiving coil unit.

[0022] In this embodiment, the power receiving coil 41 is a flat spiral coil formed by winding a wire in a square shape on the same plane around the winding axis AX, and has an air core surrounded by the wire. Note that the "radial direction" in FIG. 2 indicates the radial direction of the power receiving coil 41, which is a spiral coil formed by winding a wire. Also, the "axial direction" in FIG. 2 indicates the direction in which the winding axis of the power receiving coil 41 extends. In the following explanation, toIn this specification, unless otherwise specified, the "radial direction" refers to the radial direction of the power receiving coil 41, and the "axial direction" refers to the direction in which the winding axis of the power receiving coil 41 extends.

[0023] The first magnetic body 42 is a square, plate-shaped base core made of a ferromagnetic material such as ferrite. The first magnetic body 42 is arranged on the upper surface of the power receiving coil 41 in the axial direction (the opposite side of the power receiving coil 41 from the power transmitting coil 51 side) so as to intersect with the winding axis AX and to be positioned at least on the projection plane of the power receiving coil 41 (covering at least the power receiving coil 41). The power receiving coil 41 and the first magnetic body 42 are arranged so as not to be in direct contact with each other via an air gap or resin.

[0024] The second magnetic body 43 is an additional core made up of multiple plate-shaped members formed of a ferromagnetic material such as ferrite. The second magnetic body 43 is arranged on the opposite side of the first magnetic body 42 from the power receiving coil 41 in the axial direction (on the upper surface side of the first magnetic body 42) so as not to come into direct contact with the power receiving coil 41 and the first magnetic body 42 via a gap or resin. Furthermore, the second magnetic body 43 is arranged so as to be radially outward from a position that is half the width (thickness) of one side of the square-shaped power receiving coil 41, w / 2, in the radial direction, where w is the radial width (thickness) of one side of the power receiving coil 41. In other words, the second magnetic body 43 is arranged without contact with the power receiving coil 41 and the first magnetic body 42, and is arranged with respect to the power receiving coil 41 outside a position that is half the coil width between the inner and outer circumferences of the power receiving coil 41 in a direction perpendicular to the winding axis AX. The area radially inside the position of half the width w / 2 of one side of the power receiving coil 41, including the air-core portion, is a prohibited area where the second magnetic body 43 must not be placed.

[0025] 2, the contactless power transmitting device 5 includes a wound power transmitting coil 51. In this embodiment, the power transmitting coil 51 is a flat spiral coil formed by winding a wire in a square shape on the same plane, and has an air core surrounded by the wire. The size of the power transmitting coil 51 in the planar direction is larger than the size of the power receiving coil 41 in the planar direction.

[0026] FIG. 4(a) illustrates a case where the second magnetic body 43 is disposed with an overlap ratio of 100% relative to the power receiving coil 41. FIG. 4(b) illustrates a case where the second magnetic body 43 is disposed with an overlap ratio of 50% relative to the power receiving coil 41. FIG. 4(c) illustrates a case where the second magnetic body 43 is disposed with an overlap ratio of 0% relative to the power receiving coil 41. The overlap ratio of the second magnetic body 43 with respect to the power receiving coil 41 represents the proportion of one side of the power receiving coil 41 that is covered by the second magnetic body 43 in the radial direction. For example, an overtap ratio of 100% represents a state in which the second magnetic body 43 covers the entire side of the power receiving coil 41 in the radial direction, as shown in FIG. 4(a). An overlap ratio of 50% represents a state in which the second magnetic body 43 covers from the outside to half the width of one side of the power receiving coil 41 in the radial direction, as shown in FIG. 4(b). Furthermore, an overlap rate of 0% indicates a state in which the second magnetic body 43 does not cover one side of the receiving coil 41 in the radial direction, and the end face of the receiving coil 41 and the end face of the second magnetic body 43 are located at the same position in the radial direction, as shown in Figure 4(b).

[0027] Fig. 5 is a graph showing the relationship between the overlap ratio of the second magnetic body 43 with respect to the power receiving coil 41 and the transmission efficiency between the coils. Fig. 6 is a graph showing the relationship between the overlap ratio of the second magnetic body 43 with respect to the power receiving coil 41 and the maximum magnetic flux density of the second magnetic body 43. The analysis conditions were that the thickness of the first magnetic body 42 was 5 mm and the thickness of the second magnetic body 43 was 1 mm.

[0028] As shown in Figure 5, the relationship between the overlap ratio of the second magnetic body 43 with respect to the receiving coil 41 and the transmission efficiency between the coils (between the transmitting coil 51 and the receiving coil 41) shows that the presence of the second magnetic body 43 improves the transmission efficiency between the coils compared to when the second magnetic body 43 is not present, regardless of the overlap ratio, and that the transmission efficiency is equivalent regardless of the overlap ratio.

[0029] Furthermore, as shown in Figure 6, the relationship between the overlap rate of the second magnetic body 43 with respect to the receiving coil 41 and the maximum magnetic flux density of the second magnetic body 43 is such that when the overlap rate is less than 50%, the maximum magnetic flux density of the second magnetic body 43 can be reduced, and when the overlap rate is 0%, the maximum magnetic flux density of the second magnetic body 43 can be reduced by 15%.

[0030] Therefore, in the contactless power supply device 10 according to the embodiment, the second magnetic body 43 is arranged so as to be positioned radially outward from a position that is half the width of one side of the power receiving coil 41, in other words, so that the overlap rate of the second magnetic body 43 with respect to the power receiving coil 41 is less than 50%. This makes it possible to improve the transmission efficiency between the coils compared to when the second magnetic body 43 is not present, while reducing the magnetic flux density of the second magnetic body 43, thereby preventing the effect of the magnetic body from being reduced.

[0031] (Embodiment 2) Next, a contactless power supply device according to a second embodiment of the present invention will be described. Note that, in the contactless power supply device 10 according to the second embodiment, descriptions of the same parts as those in the first embodiment will be omitted as appropriate.

[0032] FIG. 7 is a diagram showing a contactless power receiving device 4 and a contactless power transmitting device 5 according to the second embodiment.

[0033] 7, in the contactless power supply device 10 according to the second embodiment, a first magnetic body 42 is disposed on the upper surface side of the power receiving coil 41 in the axial direction, and a second magnetic body 43 is disposed on the lower surface side of the power receiving coil 41 in the axial direction (the side opposite the first magnetic body 42 side with respect to the power receiving coil 41). The second magnetic body 43 is disposed so as not to come into direct contact with the power receiving coil 41 and the first magnetic body 42 via an air gap or resin. In the present embodiment, the second magnetic body 43 is disposed so as not to cover one side of the power receiving coil 41 in the radial direction (apart from the projection plane of the power receiving coil 41), and so that the end face of the power receiving coil 41 and the end face of the second magnetic body 43 are positioned at the same position in the radial direction, i.e., so that the overlap rate is 0%.

[0034] Fig. 8 is a diagram illustrating the positional relationship between the end of the power receiving coil 41 and the end of the second magnetic body 43. Fig. 9 is a graph showing the relationship between the end position of the second magnetic body 43 and the magnetic flux density. Fig. 10 is a graph showing the relationship between the end position of the second magnetic body 43 and the transmission efficiency.

[0035] 8 , the position of the end face of the power receiving coil 41 is set as a reference 0 mm, the side farther from the end face of the power receiving coil 41 in the radial direction is set as a positive side, and the side closer to the power receiving coil 41 in the radial direction is set as a negative side. In this embodiment, the end position of the second magnetic body 43 is determined based on the distance between the end face of the power receiving coil 41 and the end face of the second magnetic body 43. Here, when the width w of one side of the power receiving coil 41 in the radial direction is 40 mm, a position 20 mm (−20 mm) from the reference 0 mm toward the negative side in the radial direction is the position where half the width of one side of the power receiving coil 41 is located in the radial direction.

[0036] As shown in Figures 9 and 10, when the end position of the second magnetic body 43 is located on the negative side and is located further negative in the radial direction than the position (-20 mm) that is half the width of one side of the receiving coil 41, it can be seen that the magnetic flux density of the second magnetic body 43 increases sharply and the transmission efficiency between the coils decreases.

[0037] Therefore, even in a configuration in which the second magnetic body 43 is arranged on the underside of the receiving coil 41, as in the non-contact power supply device 10 of embodiment 2, by positioning the end of the second magnetic body 43 radially outside the position of half the width of one side of the receiving coil 41, it is possible to improve the transmission efficiency between the coils compared to when the second magnetic body 43 is not present, while reducing the magnetic flux density of the second magnetic body 43, thereby preventing the effect of the magnetic body from being reduced.

[0038] (Embodiment 3) Next, a third embodiment of the contactless power supply device 10 according to the present invention will be described. Note that, in the contactless power supply device 10 according to the third embodiment, descriptions of the same parts as those in the first and second embodiments will be omitted as appropriate.

[0039] FIG. 11 is a diagram showing a case where a relay magnetic body 44 is provided between a first magnetic body 42 and a second magnetic body 43. In FIG.

[0040] 11, in the contactless power receiving device 4 of the contactless power supply device 10 according to the third embodiment, a first magnetic body 42 is arranged on the upper surface side of the power receiving coil 41 in the axial direction, and a second magnetic body 43 is arranged on the lower surface side of the power receiving coil 41 in the axial direction (the side opposite to the first magnetic body 42 side with respect to the power receiving coil 41). The second magnetic body 43 is arranged so as not to cover one side of the power receiving coil 41 in the radial direction (apart from the projection plane of the power receiving coil 41), and so that the end face of the power receiving coil 41 and the end face of the second magnetic body 43 are positioned at the same position in the radial direction, i.e., so that the overlap rate is 0%.

[0041] In this embodiment, a plate-shaped relay magnetic body 44 is provided, which extends in the axial direction (the same direction as the winding axis AX), with one end side surface in contact with the end face of the first magnetic body 42 and the other end surface facing the second magnetic body 43. The relay magnetic body 44 is arranged so as not to come into direct contact with the second magnetic body 43 via a gap or resin. The relay magnetic body 44 may be in contact with the first magnetic body 42 or may be separated from it. In the contactless power feeding device 10 according to the third embodiment, at least the power receiving coil 41, the first magnetic body 42, the second magnetic body 43, and the relay magnetic body 44 form a power receiving coil unit.

[0042] Fig. 12 is a graph showing the relationship between the transmission efficiency between the coils and the presence or absence of the relay magnetic body 44. As shown in Fig. 12, it can be seen that the transmission efficiency between the coils is improved when the relay magnetic body 44 is present compared to when the relay magnetic body 44 is not present.

[0043] Fig. 13 is a graph showing the relationship between the presence or absence of the relay magnetic body 44 and the maximum magnetic flux density of the second magnetic body 43. As shown in Fig. 13, it can be seen that the maximum magnetic flux density of the second magnetic body 43 is lower when the relay magnetic body 44 is present than when the relay magnetic body 44 is not present.

[0044] Therefore, in the contactless power supply device 10 of embodiment 3, by providing a relay magnetic body 44 in addition to the first magnetic body 42 and the second magnetic body 43, it is possible to improve the transmission efficiency between the coils compared to when the relay magnetic body 44 is not provided, while reducing the maximum magnetic flux density of the second magnetic body 43, thereby preventing the effect of the magnetic body from being reduced.

[0045] FIG. 14 is a diagram for explaining the positional relationship between the end of the power receiving coil 41, the end of the second magnetic body 43, and the end of the relay magnetic body 44. As shown in FIG.

[0046] In this embodiment, as shown in FIG. 14 , the position of the end face of the power receiving coil 41 is defined as a reference 0 mm. The side farther from the end face of the power receiving coil 41 in the radial direction is defined as a positive side, and the side closer to the power receiving coil 41 in the radial direction is defined as a negative side. In this embodiment, the end position of the second magnetic body 43 is determined based on the distance between the end face of the power receiving coil 41 and the end face of the second magnetic body 43. Here, when the width w of one side of the power receiving coil 41 in the radial direction is 40 mm, a position 20 mm (−20 mm) negative from the reference 0 mm in the radial direction corresponds to half the width of one side of the power receiving coil 41 in the radial direction. In addition, the end face of the first magnetic body 42 is located 10 mm (+10 mm) positive from the reference 0 mm in the radial direction. In addition, the end position of the relay magnetic body 44, which is provided in contact with the end face of this first magnetic body 42, is located 15 mm (+15 mm) radially from the reference 0 mm to the positive side.

[0047] Fig. 15 is a graph showing the relationship between the end position of the second magnetic body 43 and the transmission efficiency between the coils. Fig. 16 is a graph showing the relationship between the end position of the second magnetic body 43 and the maximum magnetic flux density of the second magnetic body 43.

[0048] As shown in Figures 15 and 16, by positioning the end position of the second magnetic body 43 on the positive side (radially outward) of the end position of the relay magnetic body 44, the transmission efficiency between the coils is slightly reduced, but it can be seen that the maximum magnetic flux density of the second magnetic body 43 can be further reduced.

[0049] (Embodiment 4) Next, a fourth embodiment of the contactless power supply device 10 according to the present invention will be described. Note that, in the contactless power supply device 10 according to the fourth embodiment, descriptions of the same parts as those in the first, second and third embodiments will be omitted as appropriate.

[0050] FIG. 17 is a diagram showing a case where the relay magnetic body 44 is extended along the second magnetic body 43. In FIG.

[0051] 17 , in the contactless power supply device 10 according to the fourth embodiment, the second magnetic body 43 is disposed on the power transmitting coil 51 side of the power receiving coil 41 in the axial direction. The first magnetic body 42 is disposed on the opposite side of the power receiving coil 41 from the power transmitting coil 51 side in the axial direction. The second magnetic body 43 is disposed so as not to overlap with the power receiving coil 41, in other words, the second magnetic body 43 is disposed off the projection plane of the power receiving coil 41.

[0052] The contactless power supply device 10 according to the fourth embodiment includes a relay magnetic body 44 between the first magnetic body 42 and the second magnetic body 43 in the axial direction. The relay magnetic body 44 is disposed between the first magnetic body 42 and the second magnetic body 43 via a gap or resin to avoid direct contact with the power receiving coil 41. Furthermore, the relay magnetic body 44 is disposed between the second magnetic body 43 via a gap or resin to avoid direct contact with the power receiving coil 41. For example, analysis was performed under the same conditions except for whether the relay magnetic body 44 and the second magnetic body 43 were in contact with each other. The magnetic flux density was 300 mT when the relay magnetic body 44 and the second magnetic body 43 were in direct contact with each other, and 199 mT when the relay magnetic body 44 and the second magnetic body 43 were not in contact with each other. The first magnetic body 42 and the relay magnetic body 44 may be in contact with each other or may be spaced apart.

[0053] 17 , the contactless power supply device 10 according to the fourth embodiment has an extending portion 45 extending radially along the second magnetic body 43 from the end of the relay magnetic body 44 on the second magnetic body 43 side. The relay magnetic body 44 and the extending portion 45 may be formed integrally or separately. In the contactless power supply device 10 according to the fourth embodiment, at least the power receiving coil 41, the first magnetic body 42, the second magnetic body 43, the relay magnetic body 44, and the extending portion 45 form a power receiving coil unit.

[0054] 17 , the magnetic flux density can be reduced by extending the extension portion 45 in the radial direction from the end of the relay magnetic body 44 on the second magnetic body 43 side along the second magnetic body 43 in a direction away from the power receiving coil 41. Therefore, in this embodiment, the magnetic flux density and the transmission efficiency between the coils were analyzed when the extension portion 45 was extended in the radial direction from the end of the relay magnetic body 44 on the second magnetic body 43 side along the second magnetic body 43 with the positional relationship between the relay magnetic body 44 and the second magnetic body 43 fixed.

[0055] The extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction was set to 0 mm, 20 mm, 40 mm, 60 mm, 80 mm, and 100 mm. For each extension amount, the size of the gap (GAP) between the relay magnetic body 44 (extension portion 45) and the second magnetic body 43 in the axial direction was set to 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm.

[0056] Fig. 18(a) is a diagram showing a case where the extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction is 0 [mm]. Fig. 18(b) is a diagram showing a case where the extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction is 20 [mm]. Fig. 18(c) is a diagram showing a case where the extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction is 40 [mm].

[0057] Fig. 19 is a graph showing the relationship between the extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction and the transmission efficiency between the coils. Fig. 20 is a graph showing the relationship between the extension amount of the extension portion 45 along the second magnetic body 43 in the radial direction and the maximum magnetic flux density of the second magnetic body 43.

[0058] As shown in Figures 19 and 20, regardless of the size of the gap (GAP) between the relay magnetic body 44 and the second magnetic body 43, the greater the radial extension of the extension portion 45 along the second magnetic body 43, the more the transmission efficiency between the coils improves and the maximum magnetic flux density of the second magnetic body 43 decreases.

[0059] In addition, in this embodiment, the point where the end of the relay magnetic body 44 and the end of the second magnetic body 43 are aligned at a position 20 mm radially away from the side of the relay magnetic body 44 is set to 0, and while keeping the position of the second magnetic body 43 fixed, the extension portion 45 is extended radially along the second magnetic body 43, and the transmission efficiency between the coils and the maximum magnetic flux density of the second magnetic body 43 are analyzed according to the amount of overlap of the extension portion 45 with the second magnetic body 43.

[0060] FIG. 21(a) is a diagram showing a case where the overlap amount of the extension portion 45 with respect to the second magnetic body 43 is 0 [mm]. FIG. 21(b) is a diagram showing a case where the overlap amount of the extension portion 45 with respect to the second magnetic body 43 is 20 [mm]. FIG. 21(c) is a diagram showing a case where the overlap amount of the extension portion 45 with respect to the second magnetic body 43 is 40 [mm]. FIG. 21(d) is a diagram showing a case where the overlap amount of the extension portion 45 with respect to the second magnetic body 43 is 60 [mm]. FIG. 21(e) is a diagram showing a case where the overlap amount of the extension portion 45 with respect to the second magnetic body 43 is 80 [mm].

[0061] Fig. 22 is a graph showing the relationship between the overlap amount of the extension portion 45 with respect to the second magnetic body 43 and the maximum magnetic flux density of the second magnetic body 43. Fig. 23 is a graph showing the relationship between the overlap amount of the extension portion 45 with respect to the second magnetic body 43 and the transmission efficiency between the coils.

[0062] 22, regardless of the size of the gap (GAP) between the relay magnetic body 44 (extension portion 45) and the second magnetic body 43 in the axial direction, once the extension portion 45 is extended along the second magnetic body 43 in the radial direction and the extension portion 45 overlaps the second magnetic body 43, the maximum magnetic flux density of the second magnetic body 43 increases until the overlap amount reaches 20 mm. Then, it can be seen that when the extension portion 45 is further extended along the second magnetic body 43 in the radial direction to overlap it, and the overlap amount exceeds 20 mm, the maximum magnetic flux density of the second magnetic body 43 decreases.

[0063] Furthermore, as shown in Figure 23, regardless of the size of the gap (GAP) between the relay magnetic body 44 (extension portion 45) and the second magnetic body 43 in the axial direction, it can be seen that the transmission efficiency between coils becomes higher when the extension portion 45 of the relay magnetic body 44 is extended along the second magnetic body 43 in the radial direction and the extension portion 45 is made to overlap with the second magnetic body 43, compared to an arrangement in which the extension portion 45 does not overlap with the second magnetic body 43 (overlap amount 0 [mm]).

[0064] (Embodiment 5) Next, a fifth embodiment of the contactless power supply device 10 according to the present invention will be described. Note that, in the contactless power supply device 10 according to the fifth embodiment, descriptions of the same parts as those in the first, second, third and fourth embodiments will be omitted as appropriate.

[0065] Next, the maximum magnetic flux density of the second magnetic body 43 was analyzed for cases where the second magnetic body 43 was provided in different shapes on the upper surface of the power receiving coil 41 in the axial direction, as shown in FIGS. 24(a) to 24(d). FIG. 24(a) is a diagram showing a case where the second magnetic body 43 is provided to correspond to two opposing sides of the first magnetic body 42. FIG. 24(b) is a diagram showing a case where the second magnetic body 43 is provided to correspond to four sides of the first magnetic body 42. FIG. 24(c) is a diagram showing a case where the second magnetic body 43, which is longer than the length of the sides of the first magnetic body 42, is provided to correspond to two opposing sides of the first magnetic body 42. FIG. 24(d) is a diagram showing a case where the second magnetic body 43 is provided to surround the periphery of the first magnetic body 42.

[0066] When the second magnetic body 43 was provided relative to the first magnetic body 42 as shown in FIG. 24(a), the maximum magnetic flux density of the second magnetic body 43 was 344 [mT]. When the second magnetic body 43 was provided relative to the first magnetic body 42 as shown in FIG. 24(b), the maximum magnetic flux density of the second magnetic body 43 was 260 [mT]. When the second magnetic body 43 was provided relative to the first magnetic body 42 as shown in FIG. 24(c), the maximum magnetic flux density of the second magnetic body 43 was 1754 [mT]. When the second magnetic body 43 was provided relative to the first magnetic body 42 as shown in FIG. 24(d), the maximum magnetic flux density of the second magnetic body 43 was 269 [mT]. 24(b), 24(d), 24(a), and 24(c) as the arrangement of the second magnetic body 43 relative to the first magnetic body 42. It can also be said that the arrangement of the second magnetic body 43 relative to the first magnetic body 42 as shown in FIG. 24(b) is the arrangement in which the maximum magnetic flux density of the second magnetic body 43 is lowest.

[0067] Next, in this embodiment, the effect of improving transmission efficiency depending on the shape of the second magnetic body 43 was verified by varying the conditions using the shape of the second magnetic body 43 (M-shaped, X-shaped, I-shaped, and C-shaped) and the size of the second magnetic body 43 as parameters.

[0068] Fig. 25(a) is a diagram showing a case where the mouth-shaped second magnetic body 43 is provided at 50[%] elongation, Fig. 25(b) is a diagram showing a case where the mouth-shaped second magnetic body 43 is provided at 100[%] elongation, and Fig. 25(c) is a diagram showing a case where the mouth-shaped second magnetic body 43 is provided at 200[%] elongation.

[0069] Fig. 26(a) is a diagram showing a case where the second magnetic body 43 in a cross shape is provided at 50[%] elongation, Fig. 26(b) is a diagram showing a case where the second magnetic body 43 in a cross shape is provided at 100[%] elongation, and Fig. 26(c) is a diagram showing a case where the second magnetic body 43 in a cross shape is provided at 200[%] elongation.

[0070] Fig. 27(a) is a diagram showing an I-shaped second magnetic body 43 provided at 50[%] elongation, Fig. 27(b) is a diagram showing an I-shaped second magnetic body 43 provided at 100[%] elongation, and Fig. 27(c) is a diagram showing an I-shaped second magnetic body 43 provided at 200[%] elongation.

[0071] Fig. 28(a) is a diagram showing the case where the second magnetic body 43 of the mold is provided at 50[%] elongation, Fig. 28(b) is a diagram showing the case where the second magnetic body 43 of the mold is provided at 100[%] elongation, and Fig. 28(c) is a diagram showing the case where the second magnetic body 43 of the mold is provided at 200[%] elongation.

[0072] 25 to 28, the dimensions of the receiving coil 41 (the dimensions of the first magnetic body 42) are 400 mm x 400 mm, the dimensions of the transmitting coil 51 are 700 mm x 700 mm, and the condition under which the second magnetic body 43 is extended from the end of the receiving coil 41 to become the same dimensions as the transmitting coil 51 is defined as 100% extension, half the length of 100% extension is defined as 50% extension, and twice the length of 100% extension is defined as 200% extension.

[0073] Fig. 29 is a diagram showing some of the conditions for misalignment of the power receiving coil unit with respect to the power transmitting coil 51. The power receiving coil unit shown in Fig. 29 is composed of at least the power receiving coil 41, a first magnetic body 42, and a second magnetic body 43. The misalignment of the power receiving coil unit with respect to the power transmitting coil 51 is the amount of misalignment in the X and Y directions of the center point O4 of the power receiving coil unit (power receiving coil 41) with respect to the center point O5 of the power transmitting coil 51.

[0074] The analysis conditions for the positional misalignment of the receiving coil unit relative to the transmitting coil 51 were set as 0 [mm], 175 [mm], and 350 [mm] in the Y direction, and 0 [mm], 87.5 [mm], 175 [mm], 262.5 [mm], and 350 [mm] in the X direction. Each combination of positional misalignment in the X and Y directions was analyzed, and the average values (average transmission efficiency) for all analysis conditions were summarized in a graph.

[0075] The analysis results are shown in Figures 30 and 31. Figure 30 is a graph showing the relationship between the elongation rate of the second magnetic body 43 and the average transmission efficiency. In Figure 30, (1) is the second magnetic body 43 with a square cross section, (2) is the second magnetic body 43 with an I cross section, (3) is the second magnetic body 43 with a cross cross section, and (4) is the second magnetic body with a square cross section. Figure 30 also shows a transmission efficiency curve when the horizontal axis represents the elongation rate of the second magnetic body 43.

[0076] Fig. 31 is a graph showing the relationship between the area of the second magnetic body 43 and the average transmission efficiency. In Fig. 31, (1) is the second magnetic body 43 in a square shape, (2) is the second magnetic body 43 in an I shape, (3) is the second magnetic body 43 in a cross shape, and (4) is the second magnetic body in a square shape. Fig. 31 also shows a transmission efficiency curve when the horizontal axis represents the area of the second magnetic body 43.

[0077] As can be seen from Figure 30, when the shape of the second magnetic body 43 is a mouth shape, the average transmission efficiency is the best for the elongation ratio, followed by a cross shape, a square shape, and an I shape. In addition, since the elongation ratio can be said to be equal to the length of one side of the power receiving coil unit, the mouth shape can be said to be the preferred shape under conditions where the length of one side of the power receiving coil unit cannot be secured when installing it in the vehicle 1.

[0078] 31, when the shape of the second magnetic body 43 is a square, the transmission efficiency achieved is the highest under the analysis conditions (elongation ratio of up to 225%), but similarly, a larger area is required for the second magnetic body 43. Therefore, if there is room in the size of the power receiving coil unit when mounted on the vehicle 1, it can be said that the shapes of the second magnetic body 43 that are cross-shaped, I-shaped, and J-shaped, and especially I-shaped and J-shaped, are effective. [Explanation of symbols]

[0079] 1 vehicle 2 Motor generator 3 Battery 4. Contactless power receiving device 5. Non-contact power transmission device 6 road 10. Contactless power supply device 41 Receiving coil 42 First magnetic body 43 Second magnetic body 44 Relay magnetic material 45 Extension part 51 Transmission coil

Claims

1. A contactless power supply device that supplies power from a power transmitting coil to a power receiving coil in a contactless manner, The power receiving coil is formed by winding a wire around a winding axis, a first magnetic body arranged on an opposite side of the power receiving coil from the power transmitting coil so as to intersect with the winding axis; a second magnetic body that is disposed in a non-contact state with the power receiving coil and the first magnetic body, and that is disposed with respect to the power receiving coil outside a position that is half the coil width between an inner circumference and an outer circumference of the power receiving coil in a direction perpendicular to the winding axis; Equipped with The non-contact power supply device, wherein the second magnetic body is disposed on the opposite side of the first magnetic body from the power receiving coil side.

2. A contactless power supply device that supplies power from a transmitting coil to a receiving coil in a contactless manner, The power receiving coil is formed by winding a wire around a winding axis, a first magnetic body arranged on an opposite side of the power receiving coil from the power transmitting coil so as to intersect with the winding axis; a second magnetic body that is disposed in a non-contact state with the power receiving coil and the first magnetic body, and that is disposed with respect to the power receiving coil outside a position that is half the coil width between an inner circumference and an outer circumference of the power receiving coil in a direction perpendicular to the winding axis; Equipped with the second magnetic body is disposed on the opposite side of the power receiving coil from the first magnetic body side, A contactless power supply device characterized by including a relay magnetic body extending in the same direction as the winding axis, one end of which is in contact or non-contact with the first magnetic body, and the other end of which is in non-contact with the second magnetic body.

3. The contactless power supply device according to claim 2 , further comprising an extension portion that extends from the other end of the relay magnetic body along the second magnetic body in a direction perpendicular to the winding axis.

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