Inductive charging device for a vehicle charging system

Abstract

Inductive charging device for a vehicle charging system comprising: a housing; a flat coil with radially consecutive coil turns wound around a winding axis, having a maximum radial span corresponding to a maximum distance between an innermost portion of an innermost coil turn and an outermost portion of an outermost coil turn; magnetic conductors arranged around the winding axis, comprising corner magnetic conductors (CMC) arranged in housing corner regions each CMC overlapping with the coil turns and protruding inwardly and outwardly; an inward protrusion of a CMC beyond the innermost portion of the innermost coil turn along a diagonal axis is less than / equal to 20 % of the maximum radial span, an outward protrusion of a CMC beyond the outermost portion of the outermost coil turn along a diagonal axis is less than / equal to 10 % of the maximum radial span.

Description

08.08.2025Inductive charging device for a vehicle charging system

[0001] The present invention relates to an inductive charging device for a vehicle charging system. Further, the present invention relates to a vehicle charging system.

[0002] Inductive charging devices are well-known in the art and are used for contactless charging of a battery mounted in an electrically operated vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (EV). For this purpose, a primary coil of a stationary inductive charging device is inductively coupled to a secondary coil of a vehicle-mounted inductive charging device. When an alternating current flows through the primary coil, a magnetic alternating field is generated around the primary coil. In the secondary coil, the magnetic alternating field induces a voltage that causes an alternating current flow. The alternating current may be rectified by power electronics and delivered to the battery to charge the battery.

[0003] Conventional inductive charging devices typically comprise a housing including a base and a cover, an induction coil configured to provide a magnetic field for contactless energy transfer and / or receive a magnetic field from contactless energy transfer and having a plurality of coil turns wound around a coil winding center, and a plurality of magnetic conductors distributed circumferentially around the coil winding center and configured to conduct the magnetic field. The magnetic conductors are typically designed as polygonal flat bodies arranged in a pizza pattern around the coil winding center, with each magnetic conductor extending radially with respect to the coil winding center and with a controlled gap between the magnetic conductors around the coil winding center.

[0004] Such an inductive charging device is known, for example, from document US 2020 / 0139828 A1.

[0005] Typically, the magnetic conductors of conventional inductive charging devices extend over an entire radial span of the induction coil and protrude both radially inwardly and radially outwardly with respect to the induction coil. The inventors have recognized that excessive radial protrusion of the magnetic conductors, in particular the corner magnetic conductors,MAHLE internal (CL2)can have a detrimental effect on magnetic performance and / or overall weight of an inductive charging device. With this in mind, conventional inductive charging devices leave room for improvement.

[0006] Against this background, it is an object of the present invention to provide an improved inductive charging device for a vehicle charging system and an improved vehicle charging system. In particular, it is an object of the present invention to provide an inductive charging device and a vehicle charging system with improved power transfer efficiency and / or improved overall weight.

[0007] According to a first aspect of the present invention, there is provided an inductive charging device for a vehicle or a vehicle charging system, comprising: a housing, in particular having a substantially polygonal, preferably rectangular, basic shape; a flat coil arranged at least partially in the housing and comprising a plurality of radially consecutive coil turns wound around a coil winding axis, wherein the flat coil has a maximum radial span that corresponds to a distance between a radially innermost portion of a radially innermost coil turn of the plurality of coil turns and a radially outermost portion of a radially outermost coil turn of the plurality of coil turns in a radial direction perpendicular to the coil winding axis; and a plurality of magnetic conductors arranged circumferentially around the coil winding axis, wherein the plurality of magnetic conductors comprises a plurality of corner magnetic conductors each arranged in a respective corner region of the housing, and wherein each of the plurality of corner magnetic conductors extends radially with respect to the coil winding axis so as to overlap with the plurality of radially consecutive coil turns and protrude radially inwardly beyond a radially innermost portion of a radially innermost coil turn of the plurality of coil turns and radially outwardly beyond a radially outermost portion of a radially outermost coil turn of the plurality of coil turns;MAHLE internal (CL2)wherein a radially inward protrusion of the respective corner magnetic conductor beyond the radially innermost portion of the radially innermost coil turn of the plurality of coil turns along a respective diagonal axis of the housing, which perpendicularly intersects the coil winding axis and extends between opposite corner regions of the housing, is less than or equal to 20 % of the maximum radial span, and wherein a radially outward protrusion of the respective corner magnetic conductor beyond the radially outermost portion of the radially outermost coil turn of the plurality of coil turns along the respective housing diagonal axis is less than or equal to 10 % of the maximum radial span.

[0008] According to the invention, the flat coil has a maximum radial span. The maximum radial span corresponds to or defines a maximum distance between the innermost and outermost portions or edges of the flat coil in the radial direction. In other words, the maximum radial span corresponds to or defines a maximum width of the flat coil in plan view, measured along a straight line extending radially outward from the coil winding axis.

[0009] Corner magnetic conductors distributed circumferentially around the coil winding axis are arranged in corner regions of the housing, such that each corner magnetic conductor is provided in a respective corner region. Each of the corner magnetic conductors extends radially with respect to the coil winding axis so as to overlap with the plurality of radially consecutive coil turns and protrude both radially inwardly and radially outwardly beyond the innermost and outermost coil turns in each corner region of the housing.

[0010] The radially inward protrusion of each of the plurality of corner magnetic conductors along the respective diagonal axis which intersects the coil winding axis and extends between opposite corner regions of the housing is less than or equal to 20 % of the maximum radial span. In other words, a distance or amount or length by which the respective corner magnetic conductor protrudes radially beyond the radially innermost portion or edge of the radially innermost coil turn along the respective diagonal axis of the housing is less than or equal to 20 % of the maximum radial span. Preferably, the radially inward protrusion of each of the plurality of corner magnetic conductors along the diagonal axis of the housingMAHLE internal (CL2)is greater than or equal to 10 % of the maximum radial span and less than or equal to 20 % of the maximum radial span.

[0011] The radially outward protrusion of each of the plurality of corner magnetic conductors along the diagonal axis of the housing is less than or equal to 10 % of the maximum radial span. In other words, a distance or amount or length by which the respective corner magnetic conductor protrudes radially beyond the radially outermost portion or edge of the radially innermost coil turn along the respective diagonal axis of the housing is less than or equal to 10 % of the maximum radial span. Preferably, the radially outward protrusion of each of the plurality of corner magnetic conductors along the diagonal axis of the housing is greater than or equal to 7,5 % of the maximum radial span and less than or equal to 20 % of the maximum radial span.

[0012] The inventors have recognized that by limiting the radial protrusions of the respective corner magnetic conductor in this way, an improved magnetic performance of the inductive charging device can be achieved along with a reduction in weight. In particular, radially opposite distal ends or edges of the respective corner magnetic conductor move closer together along the respective diagonal axis and thus closer to the flat coil than is the case with conventional inductive charging devices. Consequently, when viewed in the axial direction (i.e., in top view), an enlarged surface for closing the magnetic flux lines from the outside is obtained near the radially opposite distal ends or edges of the respective corner magnetic conductor, which benefits magnetic performance. In addition, this configuration enables weight savings, as less material is required for each corner magnetic conductor compared to conventional inductive charging devices.

[0013] The flat coil may be configured to provide a magnetic field for contactless energy transfer and / or receive a magnetic field from contactless energy transfer. Preferably, the term "flat coil" is herein understood as an induction coil having a substantially planar arrangement of coil turns. The flat coil may have different forms, such as, for example, spiral, helical, meander, concentric, rectangular, or serpentine patterns.MAHLE internal (CL2)

[0014] The magnetic conductors may be configured to guide the magnetic field in a suitable manner and thus increases energy transfer efficiency. The magnetic conductors may have a higher magnetic permeability than air and / or may be formed at least in part from ferrimagnetic and / or ferromagnetic materials. Preferably, the magnetic conductors, in particular the corner magnetic conductors, are arranged substantially in one plane.

[0015] Preferably, the term "diagonal axis" is herein understood as an imaginary line that extends across the housing, connecting two opposite corner regions of the housing. The diagonal axis intersects perpendicularly with the coil winding axis and serves as a reference for measuring the radial protrusions of the corner magnetic conductors. Preferably, each corner magnetic conductor extends at least partially along the respective diagonal axis of the housing.

[0016] According to a second aspect of the invention, there is provided a vehicle comprising an inductive charging device according to the first aspect or any one of its refinements.

[0017] The vehicle may be an electrically operated vehicle such as, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) or an electric vehicle (EV).

[0018] According to a second aspect of the invention, there is provided a vehicle charging system comprising: a stationary inductive charging station; and a vehicle, in particular an electrically operated vehicle; wherein at least one of the stationary inductive charging station or the vehicle comprises an inductive charging device according to the first aspect or any one of its refinements.

[0019] The vehicle may be an electrically operated vehicle such as, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) or an electric vehicle (EV). The stationary inductive charging station may be provided in or on the ground. The inductive charging station may be buried in the ground, for example. It may be provided that the inductive charging station is designed or configured for a power transfer of at least 10 kW.

[0020] Accordingly, the objective technical problem is fully solved.MAHLE internal (CL2)

[0021] In a preferred refinement of any one of the above aspects, the flat coil has a rectangular basic shape with rounded corners when viewed in an axial direction parallel to the coil winding axis.

[0022] Such a coil arrangement allows for improved utilization of the available space in the housing, particularly with respect to a housing having a rectangular basic shape, which improves power transfer efficiency. Furthermore, the limitation of the radial protrusions of the corner magnetic conductors according to the invention proves to be particularly advantageous for a flat coil with a rectangular basic shape with rounded corners. In particular, by limiting the radially inward protrusion of the respective corner magnetic conductor to 20 % of the radial span and the radially outward protrusion of the respective corner magnetic conductor to 10 % of the radial span, uniform inner and outer equivalent radii of the flux concentrator can be achieved, which improves the magnetic performance of the device. This leads to obtaining a higher surface of the flux concentrator and improves the performance in misalignment conditions.

[0023] Preferably, the rounded corners of the flat coil are each formed by a plurality of radially consecutive, curved turn sections of the plurality of coil turns, each rounded corner being arranged at least partially in a respective corner region of the housing so that the respective corner magnetic conductor overlaps at least partially with the plurality of radially consecutive, curved turn sections.

[0024] In a preferred refinement of any one of the above aspects, each side of the substantially rectangularly shaped flat coil is formed by a plurality of radially consecutive, substantially straight turn sections of the plurality of coil turns, wherein the plurality of straight turn sections of adjacent sides of the flat coil transition into one another via the respective plurality of curved turn sections.

[0025] In a preferred refinement of any one of the above aspects, the flat coil is a flat spiral coil.

[0026] A flat spiral coil is a type of coil where the wire is wound in a preferably continuous spiral pattern, lying in a single plane. The turns extend outward in progressively larger loops,MAHLE internal (CL2)maintaining a flat, planar structure throughout. Each loop of the spiral is concentric with the previous one, creating a compact and uniform design.

[0027] In a preferred refinement of any one of the above aspects, the inductive charging device further comprises a plurality of intermediate magnetic conductors each arranged between adjacent corner magnetic conductors of the plurality of corner magnetic conductors.

[0028] The plurality of magnetic conductors thus comprises a plurality of corner magnetic conductors and a plurality of intermediate magnetic conductors. The corner magnetic conductors and the intermediate magnetic conductors are preferably alternately arranged or distributed around the coil winding axis, so that each corner magnetic conductor is followed by an intermediate magnetic conductor in the circumferential direction.

[0029] Preferably, the inductive charging device comprises four, in particular exactly four, corner magnetic conductors and / or four, in particular exactly four, intermediate magnetic conductors.

[0030] In a preferred refinement of any one of the above aspects, each of the plurality of magnetic conductors, in particular each corner magnetic conductor, is formed as a flat body having a peripheral edge, the peripheral edge extending substantially parallel to the axial direction and having a first edge portion and a second edge portion which extend parallel to each other and are radially spaced apart from each other.

[0031] Preferably, the peripheral edge extends between two main surfaces of the respective magnetic conductor, in particular corner magnetic conductor, the main surfaces facing away from each other in the axial direction. The first and second edge portions are parallel to each other. Preferably, the first edge portion defines a radially innermost end and the second edge portion defines a radially outermost end of the respective magnetic conductor, in particular corner magnetic conductor, with respect to the coil winding axis.

[0032] In a preferred refinement of any one of the above aspects, each of the plurality of corner magnetic conductors is formed as a flat body, in particular a polygonal flat body, having aMAHLE internal (CL2)peripheral edge, the peripheral edge extending substantially parallel to the axial direction and having a first edge portion and a second edge portion which extend parallel to each other and are radially spaced apart from each other.

[0033] In a preferred refinement of any one of the above aspects, when viewed in the axial direction, the first edge portion and the second edge portion of the respective corner magnetic conductor each extend substantially perpendicularly to the respective diagonal axis of the housing.

[0034] With such a configuration of the corner magnetic conductors, the magnetic performance of the inductive charging device can be further improved, in particular in a case in which the flat coil has a rectangular basic shape with rounded corners when viewed along the axial direction.

[0035] In a preferred refinement of any one of the above aspects, when viewed in the axial direction, a radial distance, in particular a shortest radial distance, between the coil winding axis and the first edge portion along the respective diagonal axis is the same for each of the plurality of corner magnetic conductors, and / or a radial distance, in particular a shortest radial distance, between the coil winding axis and the second edge portion along the respective diagonal axis is the same for each of the plurality of corner magnetic conductors.

[0036] In this way, a compact design and improved magnetic performance can be achieved.

[0037] In a preferred refinement of any one of the above aspects, each corner magnetic conductor is symmetrical with respect to a plane of symmetry defined by the respective diagonal axis of the housing and the coil winding axis.

[0038] In this way, an improved, in particular more homogenous, distribution of the magnetic flux density can be achieved in this way. Furthermore, this simplifies manufacturing of the corner magnetic conductors.MAHLE internal (CL2)

[0039] Preferably, the corner magnetic conductors are arranged such that, when viewed in the axial direction, the planes of symmetry of two neighboring corner magnetic conductors enclose between them an angle of 90 degrees.

[0040] Alternatively or additionally, it may be provided that each of the plurality of intermediate magnetic conductors is symmetrical with respect to a plane of symmetry oriented parallel to the axial direction and containing the coil winding axis. Preferably, the intermediate magnetic conductors are arranged such that, when viewed in the axial direction, the planes of symmetry of two neighboring intermediate magnetic conductors enclose between them an angle of 90 degrees.

[0041] In a preferred refinement of any one of the above aspects, each corner magnetic conductor is formed as a polygonal flat body with one or more rounded corners, wherein, when viewed along the axial direction, at least one rounded corner of the one or more rounded corners is located between the radially innermost coil turn of the plurality of coil turns and the coil winding axis and has a radius which is less than or equal to 20 % of the maximum radial span.

[0042] In other words, each of the plurality of corner magnetic conductors has, in plan view, at least one rounded corner arranged radially inwardly with respect to the radially innermost portion of the radially innermost coil turn of the plurality of coil turns.

[0043] An advantage of this refinement is that the magnetic path of the magnetic field generated during power transfer can be improved. In particular, a rounded corner, as opposed to a sharp corner, helps to prevent the concentration of magnetic flux in a small, localized area. This is desirable because sharp corners tend to create hotspots where magnetic flux is concentrated, which can lead to increased power losses. If a larger radius is applied, the surface available to close the magnetic flux lines may be reduced, resulting in poorer system performance.MAHLE internal (CL2)

[0044] Preferably, the radius of the at least one rounded corner of the respective corner magnetic conductor is greater than or equal to 1 % of the maximum radial span and less than or equal to 20 % of the maximum radial span.

[0045] Preferably, each corner magnetic conductor of the plurality of corner magnetic conductors comprises two rounded corners located between the radially innermost coil turn of the plurality of coil turns and the coil winding axis, wherein each of the two rounded corners has a radius which is greater than or equal to 1 % of the maximum radial span and / or less than or equal to 20 % of the maximum radial span.

[0046] In a preferred refinement of any one of the above aspects, the magnetic conductors are designed as polygonal flat bodies arranged in pizza pattern around the coil winding center.

[0047] Preferably, an intermediate gap is formed between any two magnetic conductors of the plurality of magnetic conductors, which are adjacent to each other in the circumferential direction around the coil winding axis. Alternatively, the respective two magnetic conductors that are adjacent to each other in the circumferential direction around the coil winding axis may lie against one another so as to be in contact and / or gap-free.

[0048] In a preferred refinement of any one of the above aspects, the plurality of corner magnetic conductors and the plurality of intermediate magnetic conductors are geometrically diverse when viewed along the axial direction.

[0049] In other words, the geometries of the corner magnetic conductors differ from the geometries of the intermediate magnetic conductors. In this way, the magnetic conductors can be better adapted to the geometry of the housing and / or the geometry of the flat coil, which improves the magnetic performance.

[0050] For example, respective ones of the plurality of corner magnetic conductors may have a larger physical volume than respective ones of the plurality of intermediate magnetic conductors.MAHLE internal (CL2)

[0051] In a preferred refinement of any one of the above aspects, each of the plurality of corner magnetic conductors has a substantially hexagonal basic shape when viewed in the axial direction, and / or each of the plurality of intermediate magnetic conductors has a substantially quadrangular, in particular trapezoidal, basic shape when viewed in the axial direction.

[0052] For example, when viewed in the axial direction, the basic shape of the respective intermediate magnetic conductor may correspond to an isosceles trapezoid. Preferably, the intermediate magnetic conductors are arranged such that the parallel bases of each isosceles trapezoid run substantially parallel to the respective straight coil turn sections of the flat coil. An isosceles trapezoid is a convex quadrilateral with a line of symmetry bisecting one pair of opposite sides. It is a special case of a trapezoid. Alternatively, it can be defined as a trapezoid in which both legs and both base angles are of equal measure, or as a trapezoid whose diagonals have equal length.

[0053] Alternatively or additionally, when viewed in the axial direction, the basic shape of the respective corner magnetic conductor may be comprised of two isosceles trapezoids whose longer bases are congruent and coincide. In other words, the two isosceles trapezoids forming the basic shape of the respective corner magnetic conductor share a common longer base. The term "base" is understood herein to be one of the two parallel sides of an isosceles trapezoid. The expression "longer base" therefore refers to the longer of the two parallel sides of an isosceles trapezoid.

[0054] Preferably, the shorter bases, which are opposite each other with respect to the common longer base, correspond to the first edge portion and the second edge portion of the circumferential edge of the respective corner magnetic conductor.

[0055] In a preferred refinement of any one of the above aspects, the radially inward protrusion of each corner magnetic conductor beyond the radially innermost portion of the radially innermost coil turn along the respective diagonal is greater than its radially outward protrusion beyond the radially outermost portion of the radially outermost coil turn along the same diagonal axis.MAHLE internal (CL2)

[0056] With such a configuration of the corner magnetic conductors, the magnetic performance of the inductive charging device can be further improved.

[0057] In a preferred refinement of the second or third aspect, the inductive charging device is provided on an underside of the vehicle, in particular on an underbody of the vehicle.

[0058] In this way, efficient energy transfer can be ensured when approaching a stationary inductive charging station. When provided on the underside or the underbody of the vehicle, an orientation of the inductive charging device on the vehicle may be such that the coil winding axis extends substantially parallel to a vertical axis of the vehicle, also known as the Z-axis.

[0059] It goes without saying that the features mentioned above and those yet to be explained below cannot only be used in the respective combinations disclosed, but also in different combinations or alone without departing from the scope of the present invention.

[0060] Further features and advantages will be apparent from the following detailed description. In the drawings:Fig. 1 shows a simplified top view of an exemplary embodiment of the inductive charging device;Fig. 2 shows a simplified bottom view of a corner segment of the inductive charging device of Fig. 1;Fig. 3 shows a simplified schematic illustration of an embodiment of a vehicle charging system.

[0061] In Figs. 1 and 2, an exemplary embodiment of an inductive charging device is shown, designated by reference number 10 in its entirety. Throughout the figures, the same elements are designated with the same reference numbers.MAHLE internal (CL2)

[0062] The inductive charging device 10 comprises a housing 12, a flat coil 14 having a plurality of radially consecutive coil turns 16 wound around a coil winding axis 18, and a plurality of magnetic conductors 20 arranged circumferentially around the coil winding axis 18. The flat coil 14 and the magnetic conductors 20 are adjacent to each other in an axial direction (not illustrated) parallel to the coil winding axis 18.

[0063] For receiving the flat coil 14 and the magnetic conductors 20, the housing 12 may comprise a base 22 and a cover (not illustrated). The cover may be arranged in contact with the base 22, in particular in a fluid-tight manner, so that the components arranged therein are protected for example from environmental influences. As shown in Fig. 1, the basic shape of the housing 12 is substantially square with truncated or cut-off corners 24.

[0064] The inductive charging device 10 may comprise at least a first diagonal axis 26 which is oriented perpendicular and / or transversely to a second diagonal axis 28. The first diagonal axis 26 and the second diagonal axis 28 are each oriented perpendicular to the coil winding axis 18 and each intersect the coil winding axis 18. Furthermore, the inductive charging device 10 may comprise at least a first midpoint axis 30 which is oriented perpendicular and / or transversely to a second midpoint axis 32. The first midpoint axis 30 and the second midpoint axis 32 are each oriented perpendicular to the coil winding axis 18 and each intersect the coil winding axis 18. The diagonal axes 26, 28 and the midpoint axes 30, 32 thus span a plane that is orientated perpendicular to the coil winding axis 18. With respect to a circumferential direction 34, the midpoint axes 30, 32 may be oriented spaced apart and / or rotated in angle substantially by 45° with respect to the diagonal axes 26, 28.

[0065] The first and second diagonal axes 26, 28 each extend between opposite corner regions 36 of the quadrangular housing 12. In the illustrated embodiment, four corner regions 36 are provided by way of example. In each of the four corner regions 36, a corner magnetic conductor 38 is arranged. Therefore, a total of four corner magnetic conductors 38 are provided by way of example. Furthermore, in the illustrated embodiment, the inductive charging device 10 comprises four intermediate magnetic conductors 40 which are each arranged in the circumferential direction 34 between two adjacent ones of the four corner magnetic conductors 38. It will be understood that the number of corner magneticMAHLE internal (CL2)conductors 38 and / or the number of intermediate magnetic conductors 40 is not limited to four in each case.

[0066] In the illustrated embodiment, two of the corner magnetic conductors 38 extend along the first diagonal axis 26, and two of the corner magnetic conductors 38 extend along the second diagonal axis 28. Each corner magnetic conductor 38 is designed as a flat body with a substantially hexagonal basic shape. As illustrated in Fig. 1, when viewed along the axial direction, each corner magnetic conductor 38 is symmetrical with respect to the respective diagonal axis 26, 28 along which the respective corner magnetic conductor 38 extends. In particular, the two corner magnetic conductors 38 extending along the first diagonal axis 26 are symmetrical with respect to a first plane of symmetry 42 defined by the first diagonal axis 26 and the coil winding axis 18, and the two corner magnetic conductors 38 extending along the second diagonal axis 28 are symmetrical with respect to a second plane of symmetry 44 defined by the second diagonal axis 28 and the coil winding axis 18.

[0067] Furthermore, two of the intermediate magnetic conductors 40 extend along the first midpoint axis 30, and two of the intermediate magnetic conductors 40 extend along the second midpoint axis 30. Each corner magnetic conductor 38 is designed as a flat body with a substantially quadrangular, in particular trapezoidal, basic shape. As illustrated in Fig. 1, when viewed along the axial direction, each intermediate magnetic conductor 40 is symmetrical with respect to the respective midpoint axis 30, 32 along which the respective intermediate magnetic conductor 40 extends. In particular, the two intermediate magnetic conductors 40 extending along the first midpoint axis 30 are symmetrical with respect to a third plane of symmetry 46 defined by the first midpoint axis 30 and the coil winding axis 18, and the two intermediate magnetic conductors 40 extending along the second midpoint axis 30 are symmetrical with respect to a fourth plane of symmetry 48 defined by the second midpoint axis 32 and the coil winding axis 18.

[0068] Each of the corner magnetic conductors 38 extends radially with respect to the coil winding axis 18 so as to overlap with the plurality of radially consecutive coil turns 16 and protrude radially inwardly beyond a radially innermost portion 50 of a radially innermost coil turn 52 of the plurality of coil turns 16 and radially outwardly beyond a radiallyMAHLE internal (CL2)outermost portion 54 of a radially outermost coil turn 56 of the plurality of coil turns 16. The flat coil 14 has a maximum radial span 58 across the plurality of radially consecutive coil turns 16 in a radial direction 59 perpendicular to the coil winding axis 18.

[0069] A radially inward protrusion 80 of each corner magnetic conductor 38 beyond the radially innermost portion 50 of the radially innermost coil turn 52 of the plurality of coil turns 16 along the respective diagonal axis 26, 28 is less than or equal to 20 % of the maximum radial span 58. A radially outward protrusion 82 of the respective corner magnetic conductor 38 beyond the outermost portion 54 of the outermost coil turn of the plurality of coil turns 16 along the respective housing diagonal axis 26, 28 is less than or equal to 10 % of the maximum radial span 58.

[0070] In the illustrated embodiment, each corner magnetic conductor 38 has two rounded corners 60, 62 located between the radially innermost coil turn 52 of the plurality of radially consecutive coil turns 16 and the coil winding axis 18. Each rounded corner 60, 62 has a radius 64 which is less than or equal to 20 % of the radial span 58. The two rounded corners 60, 62 are formed at a peripheral edge 68 of the respective corner magnetic conductor 38. The peripheral edge 68 of each corner magnetic conductor 38 extends substantially parallel to the axial direction and has a first edge portion 70 and a second edge portion 72 which are oriented substantially parallel to each other and are radially spaced apart from each other. The first edge portion 70 is located closer to the coil winding axis 18 than the second edge portion 72.

[0071] As indicated in Fig. 2, the flat coil 14 has a rectangular basic shape with rounded corners 74 when viewed in an axial direction. The rounded corners 74 of the flat coil are each formed by a plurality of radially consecutive, curved turn sections 76, wherein each rounded corner 74 is arranged at least partially in a respective corner region 36 so that the respective corner magnetic conductor 38 overlaps at least partially with the plurality of radially consecutive, curved turn sections 76. Each side of the substantially rectangularly shaped flat coil 14 is formed by a plurality of radially consecutive, substantially straight turn sections 78. The straight turn sections 78 of adjacent sides of the flat coil 14 transition into one another via the curved turn sections 76.MAHLE internal (CL2)

[0072] As shown in Fig. 2, the maximum radial span 58, by way of example, is defined across the plurality of radially consecutive, curved turn sections 76, in particular along the second diagonal axis 28. However, it will be understood that the location of the maximum radial span 58 depends in particular on the basic shape of the flat coil and is thus not limited to the illustrated location.

[0073] Fig. 3 shows a simplified schematic illustration of an embodiment of a vehicle charging system, designated by reference number 100 in its entirety. The vehicle charging system 100 comprises a vehicle 102 and a stationary inducive charging station 104. In the exemplary embodiment, the vehicle 102 and the stationary inductive charging station 104 each include an inductive charging device 10 according to the embodiment shown in Figs. 1 and 2. The vehicle charging system 100 may be configured for wireless energy transmission from the (stationary) inductive charging device 10 of the stationary inductive charging station 104 to the (on-board) inductive charging device 10 of the vehicle 102. The flat coil 14 of the (stationary) inductive charging device 10 of the stationary inductive charging station 104 may be a primary coil, whereas the at least one flat coil 14 of the (onboard) inductive charging device 10 of the vehicle 102 may be a secondary coil.MAHLE internal (CL2)

Claims

Claims1. An inductive charging device (10) for a vehicle charging system (100), comprising: a housing (12), in particular having a substantially polygonal, preferably rectangular, basic shape; a flat coil (14) arranged at least partially in the housing (12) and comprising a plurality of radially consecutive coil turns (16) wound around a coil winding axis (18), wherein the flat coil (14) has a maximum radial span (58) that corresponds to a maximum distance between a radially innermost portion of a radially innermost coil turn (52) of the plurality of coil turns and a radially outermost portion of a radially outermost coil turn (56) of the plurality of coil turns (16) in a radial direction (59) perpendicular to the coil winding axis (18); and a plurality of magnetic conductors (20) arranged circumferentially around the coil winding axis (18), wherein the plurality of magnetic conductors (20) comprises a plurality of corner magnetic conductors (38) each arranged in a respective corner region (36) of the housing (12), and wherein each of the plurality of corner magnetic conductors (38) extends radially with respect to the coil winding axis (18) so as to overlap with the plurality of radially consecutive coil turns (16) and protrude radially inwardly beyond a radially innermost portion (50) of a radially innermost coil turn (52) of the plurality of coil turns (16) and radially outwardly beyond a radially outermost portion (54) of a radially outermost coil turn (56) of the plurality of coil turns (16); characterized in that a radially inward protrusion (80) of the respective corner magnetic conductor (38) beyond the radially innermost portion (50) of the radially innermost coil turn (52) along a respective diagonal axis (26, 28) of the housing (12), which perpendicularly intersects the coil winding axis (18) and extends between opposite corner regions (36) of the housing, is less than or equal to 20 % of the maximum radial span (58), and in that a radially outward protrusion (82) of the respective corner magnetic conductor (38) beyond the radially outermost portion (54) of the radially outermost coil turn (56) along the respective housing diagonal axis (26, 28) is less than or equal to 10 % of the maximum radial span (58).

2. The inductive charging device (10) according to claim 1 , wherein the flat coil (14) has a rectangular basic shape with rounded corners (74) when viewed in an axial direction LE internal (CL2)parallel to the coil winding axis (18), in particular wherein the rounded corners (74) of the flat coil are each formed by a plurality of radially consecutive, curved turn sections (76) of the plurality of coil turns (16), each rounded corner (74) being arranged at least partially in a respective corner region (36) of the housing (12) so that the respective corner magnetic conductor (38) overlaps at least partially with the plurality of radially consecutive, curved turn sections (76).

3. The inductive charging device (10) according to claim 2, wherein each side of the substantially rectangularly shaped flat coil (14) is formed by a plurality of radially consecutive, substantially straight turn sections (78) of the plurality of coil turns (16), wherein the plurality of straight turn sections (78) of adjacent sides of the flat coil (78) transition into one another via the respective plurality of curved turn sections (76).

4. The inductive charging device (10) according to any one of the preceding claims, wherein the flat coil (14) is a flat spiral coil.

5. The inductive charging device (10) according to any one of the preceding claims, further comprising a plurality of intermediate magnetic conductors (40) each arranged between adjacent corner magnetic conductors (38) of the plurality of corner magnetic conductors (38), in particular in the circumferential direction (34).

6. The inductive charging device (10) according to any one of the preceding claims, wherein each of the plurality of corner magnetic conductors (38) is formed as a flat body, in particular a polygonal flat body, having a peripheral edge (68), the peripheral edge (68) extending substantially parallel to the axial direction and having a first edge portion (70) and a second edge portion (72) which extend parallel to each other and are radially spaced apart from each other.

7. The inductive charging device (10) according to claim 6, wherein, when viewed in the axial direction, the first edge portion (70) and the second edge portion (72) of the respective corner magnetic conductor (38) each extend substantially perpendicularly to the respective diagonal axis of the housing (12). LE internal (CL2)8. The inductive charging device (10) according to claim 7, wherein, when viewed in the axial direction, a radial distance between the coil winding axis (18) and the first edge portion (70) along the respective diagonal axis (26, 28) is the same for each of the plurality of corner magnetic conductors (38), and / or a radial distance between the coil winding axis (18) and the second edge portion (72) along the respective diagonal axis (26, 28) is the same for each of the plurality of corner magnetic conductors (38).

9. The inductive charging device (10) according to any one of the preceding claims, wherein each corner magnetic conductor (38) is symmetrical with respect to a plane of symmetry (42, 44) defined by the respective diagonal axis (26, 28) of the housing (12) and the coil winding axis (18).

10. The inductive charging device (10) according to any one of the preceding claims, wherein each corner magnetic conductor (38) is formed as a polygonal flat body with one or more rounded corners, wherein, when viewed along the axial direction, at least one rounded corner (60, 62) of the one or more rounded corners is located between the radially innermost coil turn (52) of the plurality of coil turns (16) and the coil winding axis (18) and has a radius (64) which is less than or equal to 20 % of the radial span (58).

11. The inductive charging device (10) according to any one of the preceding claims, wherein: each of the plurality of corner magnetic conductors (38) has a hexagonal basic shape when viewed in the axial direction, and / or each of the plurality of intermediate magnetic conductors (40) has a quadrangular, in particular trapezoidal, basic shape when viewed in the axial direction.

12. A vehicle (102) comprising an inductive charging device (10) according to any one of the preceding claims.

13. A vehicle charging system (100) comprising: a stationary inductive charging station (104); and a vehicle (102), in particular an electrically operated vehicle; LE internal (CL2)wherein at least one of the stationary inductive charging station (104) or the vehicle (102) comprises an inductive charging device (10) according to any one of claims 1-11.LE internal (CL2)

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