Inductive charging device for vehicle charging system

Abstract

The invention relates to an inductive charging device for a vehicle charging system, comprising an energy transmission winding, at least one flux guide element and at least one first and second sensor winding, the flux guide element being suitable for guiding a magnetic field during an energy transmission between another inductive charging device and the energy transmission winding, the first and second sensor winding being arranged around at least one of the at least one flux guide element.

Description

[Technical field]

[0001] The present invention relates to an inductive charging device for a vehicle charging system according to the preamble of the independent claim.

[0002] From DE 10 2014202747 A1 a double winding system is known which is used to determine the position deviation between the primary coil and the secondary coil of an inductive charging system. The two windings of the double winding system are offset from each other by a certain angle and wound around one common ferrite element. The magnetic field of the primary coil induces a voltage in the two windings. The two voltages are evaluated by an evaluation unit and the position deviation between the primary coil and the secondary coil is calculated therefrom. In this case, it is necessary to integrate a separate component with its own ferrite element for the double winding system. Furthermore, it is not possible to position the double winding in such a way that no voltage or only a very low voltage is induced during the charging process.

[0003] The present invention addresses the problem of providing an improved or at least alternative embodiment of an inductive charging device of the type mentioned at the beginning, in particular an embodiment which reduces the complexity and improves the service life of the components used.

[0004] The ability to charge vehicles inductively offers numerous advantages over conventional conductive charging processes. Here, the comfort benefit should be mentioned above all, since the handling of charging cables and plug-in connectors, which are in some cases very heavy, is omitted. However, what is important for the inductive charging process is that the inductive charging device of the vehicle is positioned as accurately as possible with respect to the stationary inductive charging device, for example on the bottom side. This is difficult to achieve by purely manual positioning of the vehicle passing over the stationary inductive charging device, and the driver then requires assistance from an assistance system that provides information about the position deviation between the mobile inductive charging device of the vehicle and the stationary inductive charging device, or from an automatic positioning system that is directly responsible for automating the parking process. Here, a sensor device is required that can detect the corresponding position deviation. It is advantageous in this case if no initial calibration is required between the stationary inductive charging device and the mobile inductive charging device in the vehicle. Furthermore, a long range is advantageous for the positioning system as much as possible. That is, it is desirable for the positioning system to be able to accurately determine the position deviation already when the distance from the stationary inductive charging equipment to the mobile inductive charging equipment in the vehicle is at its maximum possible magnitude.

[0005] The device according to the invention having the features of the independent claims is advantageous over the prior art due to the fact that the sensor winding is integrated into the inductive charging device, without the need for additional magnetic cores or additional flux guide elements, and due to the inventive arrangement of the sensor winding, which allows the voltage induced in the sensor winding during the charging process to be reduced to a minimum. Furthermore, the proposed arrangement also makes it possible to accommodate the sensor winding in the inductive charging device of the vehicle, which is usually defined by a housing. In this case, no additional wiring is required, as would be the case if it were arranged outside the inductive charging device of the vehicle.

[0006] Important further features and advantages of the invention emerge from the respective dependent claims, the drawings and the corresponding figure description based on the drawings.

[0007] It is obvious that the features mentioned above and those to be described hereinafter can be used not only in the respective combinations mentioned, but also in other combinations or alone, without departing from the scope of the invention.

[0008] The invention proposes an inductive charging device for a vehicle charging system, characterized in that it has an energy transmission winding, at least one flux guide element and at least one first sensor winding and a second sensor winding, where the flux guide elements are suitable for guiding a magnetic field during energy transmission between a further inductive charging device and the energy transmission winding, and where the first sensor winding is arranged around at least one of the at least one flux guide elements and the second sensor winding is arranged around at least one other of the at least one flux guide elements.

[0009] During inductive charging, energy is transferred in the form of a magnetic field between two inductive charging devices, often between a stationary and a mobile inductive charging device.

[0010] The term "inductive charging device" is therefore used herein to refer to only one of at least two parts required for energy transfer for an inductive charging process. In an inductive charging process, an energy transfer winding generates an alternating magnetic field in one inductive charging device. This alternating magnetic field induces a voltage in another energy transfer winding of the other inductive charging device. This other inductive charging device is therefore used as the counter part in this particular charging process. Energy is transferred wirelessly and received by induction of a voltage.

[0011] The inductive charging device can be used for the inductive charging of vehicles. In principle, the inductive charging device according to the invention can be used for any kind of land, ship or aircraft equipped with an electric or hybrid drive. In particular, passenger cars, buses and trucks are mentioned here.

[0012] A vehicle charging system includes at least one mobile inductive charging device and another, often stationary, inductive charging device, e.g., mountable on and / or within the vehicle.

[0013] Thus, an inductive charging device on and / or in a vehicle is suitable for receiving a magnetic field and supplying electrical energy to an energy store of the vehicle, for example a battery or an accumulator in the vehicle.

[0014] In principle, the vehicle charging system can also be used for bidirectional charging, in which case the vehicle can also temporarily supply energy from an energy accumulator to the power grid via the vehicle charging system.

[0015] The inductive charging device has an energy transmission winding capable of efficiently receiving and / or transmitting a magnetic field from another energy transmission winding during the charging process, preferably capable of transmitting a power of 3 kW to 500 kW, particularly preferably 3 kW to 50 kW.

[0016] Very generally, a coil is defined here as a component that generates or receives a magnetic field. It may consist of a winding and any other elements, such as a magnetic core and a coil support. In this case, a winding is a device around which a current conductor is wound. A winding may consist of one or more turns, where a winding is one complete revolution of the conductor. Very generally, however, a winding may consist of less than one turn, i.e., for example, 0.5 turns. Of course, a non-integer number of turns is also possible, for example, 2.5 turns.

[0017] The energy transmission windings can be made in various forms, for example from high frequency Litz wire having a diameter of 0.5 mm to 10 mm, preferably made of copper.

[0018] The sensor winding is necessary for the positioning process. When the vehicle is still located at some distance from the stationary inductive charging device, for example at 5-10 m, the stationary inductive charging device can transmit a signal, preferably a magnetic field, which induces a voltage in the sensor winding. By comparison of the voltages and a corresponding evaluation, the position deviation between the vehicle and the stationary inductive charging device can be determined. In principle, it is also possible for the mobile inductive charging device to transmit a signal and for the stationary inductive charging device to receive it. The sensor winding according to the invention can be formed in various forms, here having half a turn, one turn or preferably several turns. Of course, a non-integer number of turns is also possible, for example 2.5 turns. The conductor of such a sensor winding in this case has a thickness of, for example, 0.01 mm. 2 ~2mm 2 The conductors can be configured here as Litz wires or as individual conductors or in other shapes, for example in the form of a circuit board. If the conductor structure is realized on a circuit board, the conductor tracks can have a cross-sectional area of ​​the order of 0.8 μm to 35 μm, for example.

[0019] The magnetic flux guide elements are suitable for guiding the magnetic field in a set manner. r >1, preferably μ r >50, particularly preferably μ r It has a high magnetic permeability >100. The flux guide element is a magnetic core for the energy transfer winding. In particular in this case, the magnetic field acts in such a way that, due to the high magnetic permeability, as much magnetic flux as possible is transferred to the energy transfer winding. With the flux guide element, the energy transfer winding receives a larger magnetic flux under otherwise equal parameters than it would without the flux guide element. The flux guide element can be made of a ferromagnetic material or preferably a ferrite magnetic material, particularly preferably ferrite. The flux guide element can be made preferably plate-like (in the form of a planar core) and can be arranged in the inductive charging device on the opposite side of the energy transfer winding, i.e. on the side remote from the other inductive charging device.

[0020] By arranging the first and second sensor windings around at least one of the at least one flux guide elements, at least one of the at least one flux guide elements then assumes a double function: it serves as a magnetic core for the first and / or second sensor winding and also as a magnetic core or flux guide element for the energy transmission winding, so that a separate flux guide element for the sensor windings is not required, which leads to simplified manufacturing.

[0021] Arranging the sensor winding around the flux guide element means here that the flux guide element is at least partially surrounded by the sensor winding. The first and the second sensor winding can be arranged around the same flux guide element or around two different flux guide elements or each can also be arranged around several flux guide elements.

[0022] The two sensor windings may be arranged to surround only one or more flux guide elements or may be arranged to surround further elements, such as an energy transmission winding and / or a cooling device and / or a shielding device.

[0023] Preferably, the inductive charging device according to the present invention is a mobile inductive charging device located on and / or within a vehicle or is a stationary inductive charging device.

[0024] A stationary inductive charging equipment is a non-moving part of a vehicle charging system, i.e., it does not move with the vehicle.

[0025] The stationary inductive charging device can be preferably arranged on or on the surface of or within the bottom. The device here may be an inductive charging device mounted on the ground or buried in the ground. The bottom may be a roadway, a parking lot floor, a garage floor, a parking structure, or the floor of another building. Alternatively, the stationary inductive charging device may be arranged on a wall or the like.

[0026] The device can also be a stationary inductive charging device for a dynamic inductive charging process, in which the energy accumulator of the vehicle can be charged while the energy accumulator is moving. For example, in this case the stationary inductive charging device can extend along the roadway, below, in or on the roadway surface.

[0027] A mobile inductive charging device can be located on and / or within the vehicle. Very generally, a mobile inductive charging device is understood to be that part of the vehicle charging system that moves with the vehicle.

[0028] Preferably, the first sensor winding has a first radial longitudinal direction and the second sensor winding has a second radial longitudinal direction, the first radial longitudinal direction and the second radial longitudinal direction being each arranged at an angle of 45°±10° relative to the vehicle longitudinal direction, preferably at an angle of 45°, and the first radial longitudinal direction and the second radial longitudinal direction intersect at an angle of 70° to 110°, preferably perpendicularly.

[0029] Generally, the windings extend about an axis in at least two dimensions. The main direction of extension perpendicular to the winding axis is referred to here as the radial longitudinal direction. That is to say, if the winding has a rectangular, i.e. non-square cross section, the main direction of extension extends along or parallel to the long side of the rectangle. In a winding with an elliptical cross section, the radial longitudinal direction extends along or parallel to the main axis of the ellipse. The radial longitudinal direction of the sensor winding according to the invention may preferably lie in a plane extending parallel to the ground.

[0030] A corresponding arrangement of the radial longitudinal angles is advantageous for the highest possible detection sensitivity and for the simplest possible calculation of the position deviation between the vehicle and the stationary inductive charging device.

[0031] If the two angles between the respective radial longitudinal directions of the sensor windings and the vehicle longitudinal direction are approximately equal in magnitude, this means that the sensor windings are arranged symmetrically relative to the direction of travel.

[0032] When the expression "vehicle longitudinal direction" is used in relation to a stationary inductive charging device, this relates to the "vehicle longitudinal direction" achieved when the positioning process is successfully completed, i.e. the "vehicle longitudinal direction" positioned during the energy transmission process.

[0033] This is particularly advantageous since the function of the sensor windings is also to detect lateral position deviations, in particular between the inductive charging device in the vehicle and the stationary inductive charging device. If the sensor windings are arranged symmetrically with respect to the direction of travel, then if the lateral position deviations are of equal magnitude, then the voltages induced in the sensor windings are correspondingly symmetrical, and the position deviation can thus be calculated relatively simply from the induced voltages. If the two angles are 45°, then the two sensor windings will be at an angle of 90° to one another, which is ideal for optimal evaluation of the sensor signals.

[0034] Preferably, the first sensor winding has a first radial longitudinal direction and the second sensor winding has a second radial longitudinal direction, the first radial longitudinal direction and the second radial longitudinal direction intersecting in the area of ​​a surface deployed by the energy transmission winding.

[0035] The area of ​​the surface subtended by the energy transfer winding is the surface subtended by the energy transfer winding in a plane perpendicular to the winding axis, i.e. areas inside the energy transfer winding where there are no windings are implied, but not surfaces lying outside the energy transfer winding.

[0036] It is important to note here that "direction" always means, for example, a straight line in the "radial longitudinal direction", and not a section defined by the beginning and end of a component. The intersection of the two radial longitudinal directions of the sensor windings in the area of ​​the surface developed by the energy transmission windings does not necessarily mean that the sensor windings themselves intersect, which may only occur in extension.

[0037] Arranging the two sensor windings so that the two radial longitudinal directions intersect in the area of ​​the surface developed by the energy transmission winding offers advantages when evaluating the two sensor signals. In the signal transmitted from the stationary inductive charging device for positioning, voltages are induced in the two windings, respectively, and the position deviation between the vehicle and the stationary inductive charging device can be directly deduced from the ratio of the two voltages. In particular, it is advantageous in this case if both sensor windings are arranged symmetrically with respect to the vehicle longitudinal direction.

[0038] Particularly preferably, the first radial longitudinal direction and the second radial longitudinal direction intersect at least approximately in the centre of the energy transmission winding.

[0039] The center of the energy transfer winding here refers to an area of ​​a few centimeters centered on the geometric center of the energy transfer winding in a plane perpendicular to the winding axis of the energy transfer winding. The "center" here only relates to the two dimensions in which the energy transfer winding mainly extends, i.e., for example, the driving plane. The intersection does not have to be in the center of the energy transfer winding in the direction in which the energy transfer takes place, i.e. it does not have to be located in the center with respect to the height of the vehicle, for example.

[0040] This is advantageous because in this way the two radial longitudinal directions of the two sensor windings are both inclined with respect to the vehicle longitudinal direction by an angle that is advantageous for optimal detection of position deviations between the vehicle and the stationary inductive charging device, and furthermore the sensor winding is thereby arranged relative to the energy transmission winding in such a way that the lowest possible voltage is induced in the sensor winding during the energy transmission process.

[0041] In one embodiment, the two sensor windings cross at least approximately at the center of the energy transmission winding. A weaker condition is that only the radial longitudinal directions of the two sensor windings cross approximately at the center of the energy transmission winding. In this case, the two sensor windings can be relatively short and arranged in a "V" shape. If these two sensor windings are virtually extended in their respective radial longitudinal directions, the radial longitudinal directions cross, but the two sensor windings themselves do not cross. A narrower condition is that the two sensor windings cross themselves. In this case, the sensor windings are longer compared to the "V"-shaped arrangement and actually cross. The arrangement here is "X"-shaped. In this embodiment, the sensor windings have a larger area in which voltages are induced compared to the embodiment in which the radial longitudinal directions of the sensor windings cross only in the extension lines and many voltages can be induced. In this case, the sensor windings actually cross and the crossing only in the extension lines of the sensor windings no longer occurs.

[0042] In this embodiment, it is advantageous if both sensor windings are arranged point-symmetrically with respect to the centre of the energy transmission winding.

[0043] In a preferred alternative embodiment, the inductive charging device has at least four sensor windings, where two sensor windings each are arranged on opposite sides of the center of the energy transmission winding, and all radial longitudinal directions extend approximately through the center of the energy transmission winding and / or the four radial longitudinal directions of the four sensor windings each form an angle of 45°±10°, preferably an angle of 45°, with the vehicle longitudinal direction.

[0044] The four sensor windings are therefore arranged in a cross shape around the centre of the energy transmission winding, with no sensor winding at the centre of the energy transmission winding itself. Preferably, the four sensor windings are equally spaced apart in the radial direction around the centre of the energy transmission winding and may form approximately equal angles with each other. For example, the angle between the radial longitudinal direction of each sensor winding and the radial longitudinal direction of the respective adjacent sensor winding may always be 45°±10°, preferably 45°.

[0045] This embodiment is advantageous, on the one hand, compared to the embodiment with only two sensor windings, because the arrangement here allows for a more efficient use of the construction space and therefore allows for more turns per sensor winding. Thus, more voltage is induced overall. Compared to the embodiment with two intersecting sensor windings, this embodiment also offers the advantage that there is no sensor winding in the center of the energy transmission winding, so that a stabilizing element can be introduced in this area.

[0046] In this case, the four sensor windings can be connected to one another, preferably in series, with particular preference being given to two diagonally opposite sensor windings each being connected to one another in series.

[0047] Advantageously, the first radial longitudinal direction and the second radial longitudinal direction are at least approximately parallel to a main direction of magnetic field lines which are formed in the flux guide element in the area covered by the sensor winding during energy transmission.

[0048] The main direction of the magnetic field lines refers to the direction in which the magnetic field lines mainly extend in the flux guide element at each location. In this case, it is not the exact extension characteristic of the magnetic field lines due to the sensor winding, but rather the radial longitudinal direction that is oriented in the extension direction of the magnetic field lines in the extension area of ​​the sensor winding. During the energy transfer from the stationary inductive charging device to the inductive charging device in the vehicle, the magnetic field is guided in the flux guide element or elements. If the flux guide element or elements are designed in the form of a plate, during the charging process, a magnetic field with magnetic field lines that extend approximately radially to the energy transfer winding is generated in the flux guide element. Although a voltage is indeed induced in the sensor winding during the positioning process, from which the position deviation between the vehicle and the stationary inductive charging device is calculated, it is important that during the charging process, the lowest possible voltage is induced in the sensor winding, so that the magnetic field does not become so strong that it would destroy the component or adjacent components. With regard to the induced voltage, the magnetic field component perpendicular to the radial longitudinal direction of the sensor winding is important. Therefore, in a sensor winding arrangement in which the radial longitudinal direction of the sensor winding is ensured to be at least approximately parallel to the main direction of the magnetic field lines in the flux guide element during the charging process, no or only a small voltage is induced in the sensor winding.

[0049] Alternatively, the first radial longitudinal direction and the second radial longitudinal direction may intersect outside the center of the energy transfer winding.

[0050] Preferably, the energy transmission winding is formed as a flat coil and / or as a first sensor winding and the second sensor winding is formed as a solenoid.

[0051] The flat coil may be a helical flat coil, in particular a circular helical flat coil or a rectangular helical flat coil. The helical flat coil may be wound in the form of an Archimedes spiral. The turn shape may in this case be another shape similar to a circle (circular helical flat coil), but also another shape similar to a square or rectangle or a rectangle with rounded corners (rectangular helical flat coil). Here, the helix lies in one plane. The flat coil is particularly suitable for transmitting the highest possible power between the stationary inductive charging device and the inductive charging device in the vehicle.

[0052] Solenoids are also called cylindrical coils or solenoid coils. They can be wound in the form of a spiral or cylindrical spiral. In this case, however, the shape of the turns does not have to resemble a circle, but can for example resemble a square or a rectangle or a rectangle with rounded corners. The important difference with flat coils is that the turns do not lie in one plane, but extend along an axis. However, here it is entirely possible for two or more turns to extend parallel and thus lie in the same plane perpendicular to the axis.

[0053] In this case, the shape of the solenoid is well suited to detect the signal transmitted from the stationary inductive charging device during the positioning process.

[0054] In another preferred embodiment, a number of flux guide elements are arranged radially about the center of the energy transfer winding, with the air gaps between each of the flux guide elements also extending radially.

[0055] From a manufacturing perspective, it is impossible or extremely difficult to manufacture large flux guide elements that cover the entire surface of the energy transmission winding or that protrude beyond the energy transmission winding. Therefore, in most cases, several relatively small flux guide elements must be arranged in parallel. In this case, rectangular flux guide elements can be used. These are easier to manufacture. In this case, there are always relatively small air gaps between the flux guide elements. These air gaps have a negative effect on the guidance of the magnetic field. With rectangular flux guide elements, the air gaps between the flux guide elements always extend partially perpendicular to the magnetic field lines. Advantageously, therefore, the air gaps between the flux guide elements also extend in the radial direction and thus only have a minimal effect on the guidance of the magnetic field.

[0056] Preferably, the first and second sensor windings are formed by conductor tracks applied on at least one circuit board, preferably by conductor tracks applied on at least two circuit boards, in particular by conductor tracks applied on at least one upper circuit board and at least one lower circuit board, where each turn of the sensor winding is realized in the form of a conductor track on a circuit board.

[0057] In this case, the conductor tracks can be made of copper, for example. The conductor tracks can be constructed in multiple layers, preferably in two layers. The cross section of such a conductor track can be adapted very flexibly to the boundary conditions set by the limited construction space. In particular, the cross section of the conductor track can be constructed as a rectangle with a small height, the height being in the dimension perpendicular to the ground.

[0058] The realization of the sensor winding using conductor tracks on a circuit board allows the height of the sensor winding to be significantly reduced compared to conventional windings, for example based on high-frequency Litz wire. This type of sensor winding therefore requires less construction space, especially in the dimension along the winding axis of the energy transmission winding, which is the most critical in terms of construction space. Furthermore, the manufacturing method of the circuit board-based sensor winding is simpler compared to conventional sensor windings with wound high-frequency Litz wire conductors.

[0059] Preferably, the energy transmission winding is thermally coupled to one of the at least one magnetic flux guide elements, which in turn is thermally coupled to a cooling device, preferably a cooling plate and / or a metal shield.

[0060] A component being thermally coupled to another component is understood to mean that these two components are directly connected to each other, i.e., they are in direct contact with each other or are connected to each other via a solid body capable of good thermal conductivity. That is, between the two components, there may be one or more layers or other solid bodies, such as a thermally conductive intermediate layer, a thermal interface material (TIM), a metal body or metal sheet, an adhesive having good thermal conductivity, etc. In particular, it is desirable that the thermal conduction between the two components is preferably in the range of 0.1 K / W to 1.0 K / W.

[0061] A cooling device, preferably a cooling plate, can be used to dissipate the waste heat arising from the various components of the inductive charging device. A fluid flows through such a cooling plate and the absorbed waste heat can be dissipated to this fluid. Alternatively, the cooling plate can be solid and the absorbed waste heat can be dissipated to the surrounding air, for example through cooling ribs and / or a heat exchanger. The cooling plate can be made of metal, in particular aluminum.

[0062] During inductive charging, strong magnetic and electromagnetic fields are generated. These must be shielded to prevent electrical components in the vehicle from being damaged or destroyed, or from overheating and causing damage to the vehicle. For this purpose, a metal shield can be used. A metal sheet, for example an aluminum sheet, can be used as the metal shield. However, the shield can also be somewhat thicker than the shield plate.

[0063] The metal shield can also simultaneously function as a cooling plate, for which a somewhat thicker variant as a shield plate is better suited.

[0064] It is important that the components to be cooled are well thermally coupled to the cooling plate, where thermally coupled means that the components mentioned are in thermal contact, i.e. that heat exchange between them is possible via the best possible thermally conductive connection.

[0065] In this case, the heat path leads from the energy transmission winding via at least one flux guide element to the cooling plate, i.e. the waste heat of the energy transmission winding and the at least one flux guide element can be dissipated to the cooling plate. Since the sensor windings can be arranged per area around the at least one flux guide element, it is important that these sensor windings only interfere with the heat path to a minimum. For this purpose, in particular when arranging the sensor windings on the circuit board, care should be taken to keep the area of ​​the insulating circuit board material as small as possible.

[0066] Very generally, the cooling device does not have to be configured as a cooling plate, but can be any object used for active or passive cooling.

[0067] In a preferred variant, at least one of the at least one circuit board has a smaller width in its longitudinal region than in its contact region.

[0068] The longitudinal area of ​​the circuit board is the area that runs along the radial longitudinal direction of the sensor winding. The contact areas of the circuit board are located at both ends of the longitudinal area of ​​the circuit board, where the conductor tracks of the different circuit boards can be contact-connected to each other.

[0069] In this case, the width does not have to decrease continuously in the longitudinal region, it may only be reduced in a portion or only cut out in a certain region along the width, it being important in this variant that circuit board material is saved by the fact that the circuit board is not realized completely along the longitudinal region over the entire width of the circuit board material.

[0070] The above configuration limits the insulating circuit board material to a minimum, and because insulating circuit board material is not a good conductor of heat, the optimized configuration herein allows more waste heat to be carried away from the various components of the inductive charging device.

[0071] Furthermore, only one of the two contact regions can be wider compared to the longitudinal region, while the other contact region can be configured with the same width as the longitudinal region or with a width that further increases towards the end.

[0072] In a preferred embodiment, the first and second sensor windings consist of upper conductor tracks on an upper circuit board and lower conductor tracks on a lower circuit board, the conductor tracks on the upper circuit board being connectable to the conductor tracks on the lower circuit board such that a spiral winding results.

[0073] In this case, the upper conductor path can be arranged primarily above the flux guide element or elements, and the lower conductor path can be arranged primarily below the flux guide element or elements. The concepts "upper" and "lower" or "above" and "below" relate primarily to an arrangement of the inductive charging device that runs parallel to the ground. If the charging device is arranged, for example, parallel to a wall, the concepts can also be understood in the sense of "on one side of the flux guide element" and "on the other side of the flux guide element" without departing from the scope of the invention.

[0074] In one variant, the upper conductor tracks are soldered to the lower conductor tracks.

[0075] Preferably, the upper conductor tracks are connected to the lower conductor tracks via through-contact and / or surface-soldered plug-in and socket strips. By using plug-in and socket strips, the connection can be made during the assembly of the inductive charging device without soldering the conductor tracks. This offers significant advantages in manufacturing. This is particularly true in the case of variants using through-contact plug-in and socket strips. However, when using plug-in and socket strips, if surface-mounted or surface-soldered (SMD) plug-in strips are used, the plug-in and socket strips can also be soldered, which is much simpler than a soldering process without a corresponding plug-in connector device.

[0076] In a preferred alternative variant, the upper conductor tracks are connected to the lower conductor tracks via a flexible circuit board. In this case, the upper and lower circuit boards can also be configured as rigid circuit boards. The flexible circuit board serves to complete the connection via the vertical edge faces, whereby the winding for the coil is provided around at least one flux guide element. In this way, a combination of a rigid circuit board and a flexible circuit board is produced. The combination is also called a rigid-flexible circuit board. This is also a variant, which allows for a simpler and more convenient production than in situ soldering.

[0077] In another advantageous embodiment, the upper circuit boards are connected to each other. In this case, the upper circuit board is preferably formed as a common upper circuit board. Since the circuit board itself is merely a non-conductive base of the actual circuit board, no connections that affect the electromagnetic properties are formed between the different sensor windings. The upper circuit boards are combined into one common circuit board, which allows the manufacture of a mechanically more stable component and also makes it significantly easier to implement only one component here instead of providing an upper circuit board for each sensor winding. Via such a common upper circuit board, for example, it is easier to electrically connect the sensor windings to each other, for example in series or in parallel with each other. This also makes it unnecessary to guide a small number of connecting conductors to a distant electronic circuit device. In this variant, an area around the center of the sensor windings can be left free, so that further support elements can be arranged in this area. In this case, the common upper circuit board is formed in the shape of a ring in the center.

[0078] Another option is to clip the upper circuit board to the inner ring circuit board and thus connect them together, where clipping means that a releasable connection between the upper circuit board and the ring circuit board is made by hooking or clamping or snapping.

[0079] The first and / or second sensor winding can be electrically connected to an electronic circuit arrangement. The electronic circuit arrangement can advantageously be arranged on or near the surface of the shield and / or the cooling plate. The electronic circuit arrangement can then be responsible for further processing and / or evaluation of the sensor signal from the sensor winding. In turn, the connection lines required to connect the sensor winding to the electronic circuit arrangement can be guided through further components, such as the shield and / or the cooling plate. Such feed-throughs of the connection lines, like the contact areas of the sensor winding, can be realized in the form of pin strips or in the form of flexible conductor tracks. Each circuit board can be arbitrarily shaped and / or dimensioned. Preferably, each circuit board has a shape extending in the direction of the winding with a width of 20 mm to 60 mm, in particular 30 mm to 50 mm, preferably 40 mm, formed transversely to the longitudinal direction of the turns. Thus, several windings can be arranged in particular side by side. Preferably, each circuit board has a number of turns, ie 8 to 23, in particular 11 to 19, preferably 15 turns.

[0080] It may be advantageous to reduce the number of feedthroughs required. This can be achieved by connecting two or more sensor windings in series. Alternatively or additionally, several connecting lines can be bundled and guided by one feedthrough.

[0081] In an advantageous alternative embodiment, the first and second sensor windings are formed as Litz wires, in particular as high-frequency Litz wires or as wires. High-frequency Litz wires consist of a number of wires insulated from one another. This offers an advantage, since at high frequencies the current flows mainly near the surface of the conductor, and the implementation of a large number of individual conductors allows the maximum amount of conductor surface to be utilized. Wires in this case are also realized as insulated individual wires wound in the form of multiple turns. The advantage of forming the sensor windings as high-frequency Litz wires or as wires lies in the proven and simple manufacturing form.

[0082] In this embodiment, an additional mechanical support structure can be used to prevent the high frequency litz wire or wire from slipping on the flux guide elements. Alternatively, the high frequency litz wire or wire can be glued to at least one flux guide element to prevent slipping.

[0083] Also, a spacer structure may be used that ensures a defined distance between the individual turns of the sensor winding.

[0084] Preferred embodiments of the invention are illustrated in the drawings and explained in detail in the following description, in which identical reference numbers refer to identical or similar or functionally identical components. [Brief description of the drawings]

[0085] [Figure 1] FIG. 1 shows a highly simplified view of a vehicle equipped with an inductive charging device. [Diagram 2] FIG. 1 is a cross-sectional view showing an inductive charging device for a vehicle charging system. [Diagram 3] FIG. 1 is a plan view showing an inductive charging device according to the present invention. [Figure 4] FIG. 4 is a plan view showing an inductive charging device according to another embodiment of the present invention. [Diagram 5] FIG. 4 is a plan view showing an inductive charging device according to another embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view showing a sensor winding disposed around a flux guide element. [Figure 7] FIG. 13 is a perspective view illustrating an alternative sensor winding disposed around a flux guide element. [Figure 8] 8 is a cross-sectional view showing the sensor winding of FIG. 7 taken along line VIII. [Figure 9] 1 is a cross-sectional view of a portion of an inductive charging device according to the present invention having a corresponding thermal path. [Figure 10]FIG. 11 is a plan view showing two variations of the circuit board for the sensor windings. [Figure 11] FIG. 13 is a top view of an inductive charging device according to the present invention in an alternative embodiment. [Figure 12] FIG. 13 is a perspective view showing an alternative sensor winding with pin strips and socket strips arranged around a flux guide element. [Figure 13] FIG. 13 is a plan view of an upper circuit board for a sensor winding of an inductive charging device according to the present invention in another embodiment. [Figure 14] FIG. 2 is a cross-sectional view of a portion of an inductive charging device according to the present invention having feed-throughs for lines through the shield and / or cooling plate. [Figure 15] 4 is a cross-sectional view showing a portion of another embodiment of an inductive charging device according to the present invention. FIG.

[0086] If the figures have reference numbers separated by a comma, this means that two descriptions apply to the specific referenced part. For example, in figure 1, 1a is shown, which means that this is an inductive charging device and furthermore a mobile inductive charging device.

[0087] In FIG. 1, a mobile inductive charging device 1a is shown, which is arranged on a vehicle 2 with an energy accumulator 3 and is positioned above a stationary inductive charging device 1b. During operation, energy can be transferred from the stationary inductive charging device 1b to the mobile inductive charging device 1a, so that the energy accumulator of the vehicle 3 can be charged. The mobile inductive charging device 1a and the stationary inductive charging device 1b together form a vehicle charging system 8 or are part of the vehicle charging system 8. In principle, the vehicle charging system 8 can be operated bidirectionally. In this case, energy can be temporarily transferred from the mobile inductive charging device 1a to the stationary inductive charging device 1b. The stationary inductive charging device 1b, which is arranged on the ground in FIG. 1, can alternatively be buried in the roadway (not shown here). In a buried arrangement, the inductive charging device 1b can be covered by a certain layer of the roadway or can terminate flush with the roadway surface.

[0088] 2 shows a cross-sectional side view of an inductive charging arrangement 1, 1a, which includes a number of flux guide elements 5 and energy transmission windings 4, 4a, and is mounted on a vehicle 2. A corresponding arrangement also exists for a stationary inductive charging arrangement 1b, which, however, is arranged on the ground instead of being arranged on the vehicle 2 (not shown).

[0089] In Fig. 3 a plan view of an inductive charging device 1 according to the invention is shown. The inductive charging device 1 can be a mobile inductive charging device 1a or a stationary inductive charging device 1b. In this embodiment eight flux guide elements 5 are shown, which are arranged in a plane radially about the centre 7 of the energy transmission winding 4. Narrow air gaps 27 are present between the flux guide elements 5, which likewise extend radially about the centre 7 and therefore extend approximately in the main direction of the magnetic field lines (here three magnetic field lines 14 are symbolically shown) which arise during energy transmission to the flux guide elements 5. The energy transmission winding 4 is shown with dashed lines, since in the plan view it is covered by the flux guide elements 5. The energy transmission winding 4 is here a flat coil 10. A first sensor winding 9, 9a is arranged around one flux guide element 5, and a second sensor winding 9, 9b is arranged around another flux guide element 5. The sensor windings are formed as solenoids, also referred to here as cylindrical coils. The first sensor winding 9a is arranged axially symmetrically to the second sensor winding 9b with respect to the vehicle longitudinal direction 6. The first sensor winding 9a has a first radial longitudinal direction 11a, and the second sensor winding 9b has a second radial longitudinal direction 11b. The angle 12 between the first radial longitudinal direction 11a and the longitudinal direction 6 of the vehicle 2 is at least approximately as large as the angle 13 between the second radial longitudinal direction 11b and the vehicle longitudinal direction. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b cross or intersect at least approximately in the center 7 of the energy transmission winding 4. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b extend radially outward from the center 7 of the energy transmission winding 4.

[0090] During the charging process, the vehicle 2 is positioned above the stationary inductive charging device 1b and energy is transferred to the inductive charging device 1a. The flux guide element 5 then assumes the function of flux guidance. In this case, in the charging state, the magnetic field lines run essentially radially. In FIG. 3, three magnetic field lines 14 are symbolically shown. Since the first radial longitudinal direction 11a and the second radial longitudinal direction 11b are likewise oriented radially and thus at least essentially parallel to the magnetic field lines 14, only a relatively small or no voltage is induced in the first and second sensor windings 9a and 9b. This is important, since otherwise destruction of the sensor windings would easily occur at high powers of energy transfer and thus at high magnetic flux densities. Thus, no additional costs are required to prevent destruction of the device.

[0091] In Fig. 4 and Fig. 5, for the sake of clarity, all elements or parts already shown are not referenced again. Elements or parts not given separate references in these figures are to be understood as being similar to those described in the previous figures. Fig. 4 shows a plan view of another embodiment of an inductive charging device 1 according to the invention. In contrast to the embodiment of Fig. 3, here the first sensor winding 9a extends around two flux guide elements 5 located diagonally opposite each other with respect to the center 7 of the energy transmission winding 4. The second sensor winding 9b is wound correspondingly around two further flux guide elements 5 also located diagonally opposite each other with respect to the center 7. Here the first sensor winding 9a and the second sensor winding 9b intersect approximately at the center 7 of the energy transmission winding 4.

[0092] In Fig. 5, a plan view of another embodiment of an inductive charging device 1 according to the invention is shown. Here, four sensor windings 9a, 9b, 9c, 9d with four radial longitudinal directions 11a, 11b, 11c, 11d are provided. Each sensor winding is arranged around a separate flux guide element 5. Two flux guide elements each are located diagonally opposite each other with respect to the center 7 of the energy transmission winding 4. The four sensor windings 9a, 9b, 9c, 9d together form a cross-shaped arrangement similar to that described above. The advantage over the arrangement of Fig. 4 is that in this case the area of ​​the center 7 of the energy transmission winding 4 is constructed without a sensor winding 9. Mechanically necessary support elements (not shown) can therefore be arranged in addition in this embodiment.

[0093] 6 shows the flux guide element 5. Around the flux guide element a sensor winding 9 is arranged. The sensor winding 9 is formed as a copper Litz wire 15.

[0094] Figure 7 shows a perspective view of an alternative embodiment of a flux guide element 5 with a sensor winding 9, and Figure 8 shows a cross-section thereof along the section line VIII of Figure 7. Here, the sensor winding 9 is designed in the form of a circuit board 16 with a conductor track 17. An upper conductor track 17a on an upper circuit board 16a is connected to a lower conductor track 17b on a lower circuit board 16b in such a way as to form a continuously extending winding.

[0095] FIG. 9 shows the thermal coupling of the various components to the cooling plate 18 and / or the metal shield 26. The cooling plate 18 or the metal shield 26 are not shown in all previous examples for the sake of clarity, but can also be provided in all previous and following examples. The cooling plate 18 can be solid, can be realized as a thin metal sheet or can be circulated through by a fluid. The cooling plate 18 can additionally assume the function of the metal shield 26 or can be constructed as a separate component. Only one cooling plate 18 or only one metal shield 26 can be provided. The energy transmission winding 4 transfers its heat via the lower circuit board 16b to the flux guide element 5. Here, the heat is guided to the cooling plate 18 or the metal shield 26 together with the heat generated there via the upper circuit board 16a. Since the circuit board 16 does not have a very good thermal conductivity, it is important that the circuit board material is used only where necessary.

[0096] 10 thus shows two different possibilities for the optimized shape of the circuit board 16. The width of the circuit board 19 is significantly smaller in a longitudinal region 20 of the circuit board 12 than in a contact region 21 of the circuit board. The longitudinal region 20 of the circuit board is a region that extends along the upper or lower surface of the flux guide element 5. In the right-hand embodiment, one of the two contact regions 21 is additionally formed with a semicircular tip.

[0097] In the previous exemplary embodiments, flux guide elements 5 are shown which do not have any interruptions along the magnetic field lines which arise in the radial direction during the charging process. As shown in figures 3 to 7, the air gaps between the flux guide elements likewise always extend in the radial direction. This is favorable for the guidance of the magnetic field.

[0098] However, for manufacturing reasons, a rectangular flux guide element 5, as shown in FIG. 11, is also conceivable. Here, however, the air gap 27 does not run parallel to the direction of the magnetic field lines occurring in the flux guide element 5. The sensor windings 9a, 9b can also be arranged around the flux guide element 5, and again the sensor windings 9a, 9b cross at least approximately in the center 7 of the energy transmission winding. In this embodiment, the same circuit board is used for the two sensor windings 9a, 9b. The conductor tracks of the sensor windings 9a, 9b are located on different "layers" of the circuit board and therefore also cross without short circuits. Furthermore, in FIG. 11 the energy transmission winding 4 also has a rectangular shape.

[0099] 12 shows another alternative embodiment in which the sensor winding 9 is arranged around the flux guide element 5. Here too, the sensor winding 9 is formed from a conductor track 17 on the circuit board 16. The connection between the upper conductor track 17a on the upper circuit board 16a and the lower conductor track 17b on the lower circuit board 16b is in this case formed by a pin strip 22 and a socket strip 23.

[0100] Another embodiment is shown in Fig. 13. Here, only an upper circuit board 16a for the sensor windings 9a, 9b, 9c, 9d for an inductive charging device 1 is shown. Here, four upper circuit boards 16a are shown for four sensor windings 9a, 9b, 9c, 9d. However, in this case, the upper circuit boards 16a are connected to each other in the form of a ring in the region of the center 7 of the energy transmission winding 4. This has manufacturing advantages. In this embodiment, it is also possible to attach a mechanical support in the center of the sensor winding.

[0101] 14 shows a cross-sectional view of a part of an inductive charging device according to the invention with feed-through connections of the lines 24 through the shield 26 and / or through the cooling plate 18 to the electronic circuit arrangement 25. The shield 26 and the cooling plate 18 may be the same part.

[0102] The upper conductor track 17a is arranged with the lower conductor track 17b in a manner surrounding the flux guide element 5 and is interconnected to form a sensor winding 9, which is connected for evaluation by an electronic circuit arrangement 25 via two electrical lines per sensor winding, which are connected to the upper conductor track 17a on the upper circuit board 16a. Above the sensor winding 9, a metal shield 26 and / or a cooling plate 18 are arranged. The electronic circuit arrangement 25 is located on the metal shield 26 and / or on the cooling plate 18 or above the metal shield 26 and / or above the cooling plate 18. A through-connection of the lines 24 through the metal shield 26 and / or the cooling plate 18 is therefore necessary here. For this purpose, in the present example, recesses are formed in the metal shield 26 and / or the cooling plate 18, which enable lines to be guided through the metal shield 26 and / or the cooling plate 18 and connected to the electronic circuit device 25 above the metal shield 26 and / or the cooling plate 18.

[0103] A separate feed-through of the lines 24 through the shield 26 and / or cooling plate 18 for each sensor winding 9 does not have to be realized. It is also possible to connect multiple sensor windings 9 to one another (in series or in parallel or in a combination thereof) and to realize a single feed-through of the lines 24 for these multiple sensor windings 9.

[0104] In Fig. 15, a cross-sectional view of an alternative inductive charging device according to the invention is shown. Here too, the sensor winding 9 is realized from a number of conductor tracks 17 on a circuit board 16 and is arranged around the flux guide element 5. For this, the upper conductor tracks 17a on the upper circuit board 16a are electrically connected to the lower conductor tracks 17b on the lower circuit board 16b. In this case, the upper circuit board 16a is not arranged directly above the flux guide element 5, and the lower circuit board 16b is not arranged directly below the flux guide element 5. The sensor winding 9 in the form of two circuit boards 16 again further surrounds the shield 26 and / or the cooling plate 18 as well as the energy transmission winding 4. The upper circuit board 16a is here arranged above the shield 26 and / or the cooling plate 18. The lower circuit board 16b is here arranged below the energy transmission winding 4. [Explanation of symbols]

[0105] 1 Inductive charging device 1a Mobile inductive charging device 1b Stationary inductive charging device 2 Vehicles 3 Vehicle Energy Storage Unit 4 Energy transmission winding 4a Energy transmission winding of a mobile inductive charging device 4b Energy transmission winding of stationary inductive charging device 5 Flux guide element 6 Vehicle longitudinal direction 7. Center of energy transmission winding 8 Vehicle Charging System 9 Sensor Winding 9a First sensor winding 9b Second sensor winding 9c Third sensor winding 9d Fourth sensor winding 10 Flat coil 11 Radial longitudinal direction 11a first radial longitudinal direction 11b Second radial longitudinal direction 11c Third radial longitudinal direction 11d 4th radial longitudinal direction 12 First Angle 13 Second Angle 14 Main direction of magnetic field lines 15 Litz wire 16 circuit board 16a Upper circuit board 16b Lower circuit board 17 Conductor Path 17a Upper conductor path 17b Lower conductor track 18 Cooling plate 19 Circuit Board Width 20 Longitudinal area of ​​circuit board 21 Circuit Board Contact Area 22 pin strip 23 Socket Strip 24 Line through-connection 25 Electronic circuit equipment 26 Metal shield with optional cooling function 27 Air gap between flux guide elements

Claims

1. An inductive charging device (1) for a vehicle charging system (8), comprising: The magnetic flux guiding element (5) includes an energy transmission winding (4), at least one flux guide element (5), and at least one first sensor winding (9a) and a second sensor winding (9b), The magnetic flux guide element (5) is suitable for guiding a magnetic field during energy transmission between another inductive charging device (1) and the energy transmission winding (4), the first sensor winding (9a) and the second sensor winding (9b) are arranged around at least one of the at least one flux guide element (5); Inductive charging device (1).

2. the inductive charging device (1) is a mobile inductive charging device (1a) located on and / or within a vehicle (2), or The inductive charging device (1) is a stationary inductive charging device (1b). An inductive charging device (1) according to claim 1.

3. the first sensor winding (9a) has a first radial longitudinal direction (11a); the second sensor winding (9b) has a second radial longitudinal direction (11b); the first radial longitudinal direction (11a) is disposed at an angle of 45°±10° relative to the vehicle longitudinal direction (6), preferably at an angle of 45°; the second radial longitudinal direction (11b) is disposed at an angle of 45°±10°, preferably at an angle of 45°, relative to the vehicle longitudinal direction (6); The first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect at an angle of 70° to 110°, preferably perpendicularly. An inductive charging device (1) according to claim 1 or 2.

4. the first sensor winding (9a) has a first radial longitudinal direction (11a); the second sensor winding (9b) has a second radial longitudinal direction (11b); the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect in the area of ​​the surface developed by the energy transmission winding (4); An inductive charging device (1) according to claim 1 or 2.

5. the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect at least approximately at the center (7) of the energy transmission winding (4); An inductive charging device (1) according to claim 3.

6. The inductive charging device (1) has at least four sensor windings (9), two of each are arranged on opposite sides of the center (7) of the energy transmission winding (4); the four radial lengths (11a, 11b, 11c, 11d) of the four sensor windings extend substantially through the center (7) of the energy transfer winding (4); and / or the four radial longitudinal directions (11a, 11b, 11c, 11d) of the four sensor windings (9a, 9b, 9c, 9d) each form an angle of 45°±10°, preferably 45°, with respect to the vehicle longitudinal direction (6); An inductive charging device (1) according to claim 1 or 2.

7. 4. The inductive charging device (1) according to claim 3, wherein the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) extend at least approximately parallel to a main direction of magnetic field lines (14) formed in the area covered by the sensor winding in the magnetic flux guide element (5) during energy transmission.

8. 4. The inductive charging device (1) according to claim 3, wherein the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect outside the center (7) of the energy transmission winding (4).

9. the energy transmission winding (4) is formed as a flat coil (10) and / or the first sensor winding (9a) and the second sensor winding (9b) are formed as solenoids; An inductive charging device (1) according to claim 1 or 2.

10. The plurality of magnetic flux guide elements (5) are arranged in a radial direction around the center (7) of the energy transmission winding (4), and air gaps (27) between the magnetic flux guide elements (5) also extend in the radial direction. An inductive charging device (1) according to claim 1 or 2.

11. the first sensor winding (9a) and / or the second sensor winding (9b) are formed by conductor tracks (17) applied to at least one circuit board (16), preferably by conductor tracks (17) applied to at least two circuit boards (16a, 16b), in particular by conductor tracks (17) applied to at least one upper circuit board (16a) and at least one lower circuit board (16b); An inductive charging device (1) according to claim 1 or 2.

12. the energy transmission winding (4) is thermally coupled to the at least one flux guide element (5); the at least one magnetic flux guide element (5) is thermally coupled to a cooling device, preferably a cooling plate (18) and / or a metal shield (26); An inductive charging device (1) according to claim 1 or 2.

13. 12. The inductive charging device (1) of claim 11, wherein at least one of the at least one circuit boards (16) has a width (19) in the longitudinal region of the circuit board (20) that is smaller than in the contact region of the circuit board (21).

14. 12. The inductive charging device (1) according to claim 11, wherein the first sensor winding (9a) and the second sensor winding (9b) comprise upper conductor paths (17a) on at least one upper circuit board (16a) and lower conductor paths (17b) on at least one lower circuit board (16b).

15. 15. The inductive charging device (1) according to claim 14, wherein the upper conductor track (17a) is soldered to the lower conductor track (17b).

16. 16. The inductive charging device (1) according to claim 15, wherein the upper conductor path (17a) is connected to the lower conductor path (17b) via through-contact-connected and / or surface-soldered plug-in and socket strips.

17. 15. The inductive charging device (1) according to claim 14, wherein the upper conductor path (17a) is connected to the lower conductor path (17b) via a flexible circuit board.

18. 15. The inductive charging device (1) according to claim 14, wherein the upper circuit boards (16a) are interconnected and are in particular formed as a common upper circuit board (16a).

19. the first sensor winding (9a) and the second sensor winding (9b) are formed as Litz wires, in particular as high-frequency Litz wires (15), or as wires; An inductive charging device (1) according to claim 1 or 2.

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