Inductive charging device for vehicles

Abstract

The invention relates to an inductive charging device for a vehicle charging system, which has an energy transmission winding, at least one flux guide element and at least one positioning signal winding, the positioning signal winding being configured as a solenoid with a winding axis in the vehicle longitudinal direction or in a target vehicle longitudinal direction, the flux guide element being suitable for guiding a magnetic field during an energy transmission process between a further inductive charging device and the energy transmission winding, the positioning signal winding surrounding at least one of the at least one flux guide element and the energy transmission winding.

Description

[Technical field]

[0001] The present invention relates to an inductive charging device for a vehicle charging system as well as to a vehicle charging system according to the preambles of the respective independent claims.

[0002] DE 10 2018 210 726 A1 describes a positioning antenna, which is used to position an inductive secondary unit relative to a primary unit. In this case, the coil core of the positioning antenna is simultaneously used as the coil core of a charging coil for inductive energy transfer. The positioning antenna can generate or receive a measuring magnetic field for positioning. The positioning antenna is realized as a cylindrical coil comprising several turns of a conductor and made of a flat band cable. The positioning antenna has an advantageous directional effect. In this case, the positioning antenna must always be positioned between the coil core and the charging coil, which is laborious. Furthermore, a correspondingly advantageous receiver for a simple positioning antenna with an advantageous directional effect is not shown.

[0003] The present application proposes an inductive charging device for a vehicle charging system comprising an energy transmission winding, at least one magnetic flux guide element and at least one positioning signal winding, in which the positioning signal winding is configured as a solenoid having a winding axis in the vehicle longitudinal direction or in a target vehicle longitudinal direction, and in which the positioning signal winding surrounds at least one of the at least one magnetic flux guide element and surrounds the energy transmission winding.

[0004] During inductive charging, energy is transferred in the form of a magnetic field between two inductive charging devices, most often between a stationary and a mobile inductive charging device.

[0005] Thus, the term "inductive charging device" here refers to only one of at least two parts required for an inductive energy transfer process. In an inductive energy transfer process, an energy transfer winding generates an alternating magnetic field in an inductive charging device. This alternating magnetic field induces a voltage in another energy transfer winding of the other inductive charging device. The other inductive charging device is thus used as the counter part in this particular energy transfer process. Energy is transmitted wirelessly and received by induction of a voltage.

[0006] 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 all types of land vehicles, ships or aircraft with electric or hybrid drives. In particular, passenger cars, buses and trucks are mentioned here.

[0007] 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.

[0008] Thus, the inductive charging device on and / or in the vehicle is suitable for receiving a magnetic field and supplying electrical energy to an energy storage of the vehicle, for example a battery or an accumulator in the vehicle. Basically, the vehicle charging system can also be used for bidirectional charging. In this case, the vehicle can also temporarily supply energy from the energy storage to the power grid via the vehicle charging system. The inductive charging device has an energy transmission winding that can efficiently receive a magnetic field from another energy transmission winding and / or transmit a magnetic field during the energy transmission process. In this case, a power output of preferably 3 kW to 500 kW, particularly preferably 3 kW to 50 kW, can be transmitted.

[0009] 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 turn 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.

[0010] 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.

[0011] The energy transmission winding can be configured as a flat coil. The flat coil can be a helical flat coil, in particular a circular helical flat coil or a rectangular helical flat coil. The helical flat coil can be wound in the form of an Archimedes spiral. The shape of the turns can in this case be similar to a circle (circular helical flat coil), but also other shapes, for example similar to a square or a rectangle or similar to a rectangle with rounded corners (rectangular helical flat coil). Here, the spiral lies in one plane. The flat coil is particularly suitable for transmitting the highest possible power between a stationary inductive charging device in a vehicle and a mobile inductive charging device.

[0012] The energy transmission winding may alternatively be configured similar to a flat coil distributed across multiple planes, for example across three planes, in a shape similar to a truncated pyramid.

[0013] 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 rIt has a high magnetic permeability >100. The flux guide element is a magnetic core for the energy transmission 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 transmitted to the energy transmission winding. With the flux guide element, the energy transmission 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 or preferably a ferrimagnetic 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 transmission winding, i.e. on the side remote from the other inductive charging device.

[0014] The positioning signal winding can transmit a positioning signal during the positioning process. For example, the positioning signal winding can generate an alternating magnetic field with a certain frequency based on an alternating voltage. In principle, the energy transmission winding can also transmit a positioning signal, but as proposed here, it is advantageous to use a separate positioning signal winding for forming the positioning signal. In particular, the positioning signal winding can generate a magnetic field that is suitable for positioning and allows a larger range, especially at the same power. The energy transmission winding is designed to be coupled as well as possible to the corresponding counter part. The energy transmission winding therefore generally does not have a large range for transmitting or receiving a magnetic field in the vehicle longitudinal direction or in the target vehicle longitudinal direction. However, this is important for the positioning process.

[0015] During positioning, the maximum possible power or magnetic field of the positioning signal is significantly limited. The maximum possible power or magnetic field of the positioning signal is significantly smaller than during the energy transfer process. During the positioning process, no vehicle is present on the stationary inductive charging device. Thus, for example, a person may be present on the stationary inductive charging device. In order for the magnetic field to be non-hazardous for people, a magnetic flux density of 27 μT or 6.25 μT, depending on the frequency range, must not be exceeded. The proposed positioning signal winding makes it possible to generate a positioning signal that maintains the limit or reference value and yet allows a high range.

[0016] 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 resemble other shapes, for example a square or a rectangle or a rectangle with rounded corners. An 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.

[0017] The stationary inductive charging equipment has a target vehicle longitudinal direction, which is the direction in which the vehicle longitudinal direction should be located after the positioning process is successfully completed.

[0018] When the positioning signal winding is in a mobile inductive charging device of a vehicle, the winding axis of the positioning signal winding is oriented in the vehicle longitudinal direction. When the positioning signal winding is in a stationary inductive charging device, the winding axis of the positioning signal winding is oriented in the target vehicle longitudinal direction.

[0019] In the proposed arrangement, the flux guide elements are responsible for guiding the magnetic field for energy transmission during the energy transmission process and for guiding the magnetic field for positioning during the positioning process, i.e. the flux guide elements here assume a double function, which is particularly advantageous, since this allows an efficient use of material and construction space.

[0020] It is advantageous to arrange the positioning signal winding around at least one of the at least one flux guide elements and around the energy transmission winding, since in this case the positioning signal winding can be arranged around an otherwise complete and pre-mounted induction charging device. Furthermore, if the positioning signal winding is arranged around at least one of the at least one flux guide elements and around the energy transmission winding, a larger area is formed by the positioning signal winding than, for example, if it is arranged only around one or more flux guide elements. Thus, for the same power, local maxima of the magnetic flux density are significantly reduced, or in other words, a higher power can be used while maintaining the magnetic flux density reference value or magnetic flux density limit value, and thus a higher range can be achieved.

[0021] Particularly preferably, the positioning signal winding can be arranged around the entire width of the inductive charging device, which makes it possible to cover as large an area as possible and thus to generate as homogeneous a magnetic field as possible.

[0022] Preferably, the inductive charging device according to the present invention is a mobile inductive charging device located on and / or within a vehicle or a stationary inductive charging device.

[0023] A stationary inductive charging device is a non-moving part of a vehicle charging system, i.e., a part that does not move with the vehicle. The stationary inductive charging device may be preferably located on or at or within the bottom. In this case, the device may be a ground-mounted inductive charging device or an inductive charging device that is buried on or within the ground. The bottom may be a roadway, a parking lot floor, a garage floor, a parking structure, or a floor of another building. Alternatively, the stationary inductive charging device may be located on a wall, etc.

[0024] The device may 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 vehicle is moving, for example, in this case the stationary inductive charging device can extend along the roadway, below, in or on the roadway surface.

[0025] A mobile inductive charging device can be located on and / or within a vehicle. Very generally, a mobile inductive charging device is understood to be a part of a vehicle charging system that moves with the vehicle.

[0026] Preferably, the positioning signal winding is formed by a conductor track deposited on at least one circuit board, preferably on at least two circuit boards.

[0027] Here, the turns of the positioning signal winding are realized in the form of conductor tracks on a circuit board. In this case, the conductor tracks can be made, for example, from copper. 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 here being in the dimension perpendicular to the ground.

[0028] The realization of the positioning signal winding using conductor tracks on a circuit board allows the height of the positioning signal winding to be significantly reduced compared to conventional windings, for example based on high-frequency Litz wire, and therefore requires less construction space, especially in the dimension along the winding axis of the energy transmission winding, which represents the greatest problem in terms of construction space.

[0029] Preferably, at least two circuit boards are used for the positioning signal winding, where one circuit board can be arranged on one side of the flux guide element, for example above, and another circuit board on the other side of the flux guide element, for example below. The conductor tracks provided on the two circuit boards are connected here by correspondingly flexible or non-flexible connections and thus form a winding. Furthermore, the manufacturing process for a winding based on a circuit board is simpler than for a conventional winding with wound high-frequency Litz wire conductors.

[0030] In an advantageous alternative embodiment, the positioning signal winding is configured as a Litz wire, in particular as a high-frequency Litz wire, or as a wire.

[0031] High-frequency litz wire consists of several wires insulated from one another. This offers advantages, since at high frequencies the current flows mainly close to 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. Wire in this case also refers to the implementation of insulated individual wires wound in the form of several turns. The advantage of forming the positioning signal winding as high-frequency litz wire or as wire is the proven and simple manufacturing method.

[0032] 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 element. Alternatively, the high-frequency litz wire or wire can be glued to at least one flux guide element to prevent slipping. Also, a spacer structure can be used that ensures a defined distance between the individual turns of the positioning signal winding.

[0033] Preferably, the positioning signal winding at least approximately intersects with the winding axis of the energy transmission winding, where, depending on the geometry of the energy transmission winding, it is not possible in each case to assign a winding axis directly and unambiguously to said energy transmission winding, in which case the winding axis is regarded as lying approximately in the geometric center of the energy transmission winding.

[0034] Such an arrangement is advantageous, since the voltage induced in the positioning signal winding during the energy transfer process is as low as possible, since otherwise the high powers occurring during the energy transfer could destroy or damage the positioning signal winding. Of importance for this is, among other things, the main direction of the magnetic flux in the at least one flux guide element. The main direction of the magnetic field lines is the direction in which the magnetic field lines mainly extend in the flux guide element at each location. Here, the magnetic field lines mainly extend tangentially. It is therefore advantageous for the arrangement of the positioning signal winding to cross approximately through the center of the energy transfer winding, i.e. through the winding axis of the energy transfer winding, since in this case the conductors of the positioning signal winding extend at least approximately parallel to the magnetic field lines and therefore only very low voltages are induced.

[0035] In a preferred alternative embodiment, the positioning signal winding is arranged away from the centre of the energy transmission winding, in particular near an edge of the energy transmission winding of the inductive charging device or near an edge of the inductive charging device.

[0036] In this embodiment, the positioning signal winding is offset with respect to the position where it intersects with the winding axis of the energy transmission winding, i.e., the positioning signal winding is not centrally located with respect to the energy transmission winding and is not centrally located within the inductive charging device. The positioning signal winding is located closer to the inductive charging device forming the counter part or further away from the inductive charging device compared to the center of the energy transmission winding. The positioning signal winding is spaced apart from the center of the energy transmission winding in the direction of one edge. Here, "edge" merely means that the energy transmission winding or the inductive charging device terminates at the edge, but does not constitute a description of the shape of the edge (e.g. rounded or not rounded). In this case, the edge is in particular the leading edge or the trailing edge in the mobile inductive charging device with respect to the vehicle longitudinal direction and in the stationary inductive charging device with respect to the target vehicle longitudinal direction. For example, the positioning signal winding may be located near the edge, or may be located, for example, halfway from the edge to the center of the energy transfer winding.

[0037] Arranging it spaced apart from the center of the energy transmission winding has the advantage, firstly, that in this embodiment it is possible to find a position for the positioning signal winding whose placement is not made difficult by other components, for example support elements or interruptions in the flux guide elements.

[0038] Furthermore, the arrangement at a distance from the center of the energy transmission winding is advantageous in terms of the positioning method. If the positioning signal winding is located closer to the inductive charging device forming the counter part compared to the center of the energy transmission winding, the range is increased. If the positioning signal winding is located further away from the inductive charging device forming the counter part compared to the center of the energy transmission winding, it is possible to carry out the positioning method further up to a smaller minimum distance between the two inductive charging devices. Overall, the positioning method with the vehicle charging system according to the invention not only achieves a maximum range, but also results in a very small distance between the two inductive charging devices, at which the sensor winding no longer produces a usable signal. Thus, for example, for areas where two inductive charging devices are located very close to each other, a different proximity positioning method can be used. However, this method has a very short range. What is important here is that the minimum distance at which the positioning method is possible with the inductive charging device according to the invention is as small as possible. This is achieved by arranging the positioning signal winding further away from the inductive charging device forming the counter part compared to the center of the energy transmission winding.

[0039] Furthermore, the invention proposes a vehicle charging system with a first inductive charging device and a further inductive charging device, where the first inductive charging device has at least one energy transmission winding, at least one flux guide element and at least one positioning signal winding, where the positioning signal winding is configured as a solenoid with a winding axis in the vehicle longitudinal direction or in a target vehicle longitudinal direction, and the further inductive charging device has at least one energy transmission winding, at least one flux guide element, a first sensor winding with a first radial longitudinal direction and a second sensor winding with a second radial longitudinal direction, where the first radial longitudinal direction and the second radial longitudinal direction are arranged at an angle of 70° to 110° to each other, preferably perpendicular to each other and at an angle of 35° to 55° to the vehicle longitudinal direction or in the target vehicle longitudinal direction, preferably at an angle of 45° to the vehicle longitudinal direction or in the target vehicle longitudinal direction.

[0040] Such a configuration and arrangement of the positioning signal winding and the sensor winding is advantageous both for the positioning process and for the energy transfer process. By configuring the positioning signal winding as a solenoid with a winding axis in the vehicle longitudinal direction or in the target vehicle longitudinal direction, a magnetic field is generated with a main direction of magnetic field lines in the vehicle longitudinal direction or in the target vehicle longitudinal direction. On the one hand, this has the advantage that for positioning, this configuration allows a significantly larger range than would be possible with the same power or the same field strength by the positioning signal generated by the energy transfer winding. Furthermore, such an orientation of the magnetic field is particularly well suited to allow the simplest possible detection of position or angle deviations in the sensor winding.

[0041] Particularly preferably, the positioning signal winding is designed with a particularly large extension in the driving plane and perpendicular to the vehicle longitudinal direction or the target vehicle longitudinal direction, for example, the positioning signal winding can extend over the entire width of the inductive charging device, in order to obtain a sufficiently homogeneous magnetic field with a main direction of magnetic flux in the vehicle longitudinal direction or the target vehicle longitudinal direction.

[0042] The proposed arrangement of the sensor windings is likewise advantageous for an optimized positioning process: if the sensor windings are arranged symmetrically relative to the vehicle longitudinal direction or the target vehicle longitudinal direction, a simple comparison of the voltages induced in the two sensor windings makes it possible to determine the angular deviation with respect to a homogeneous magnetic field with a clear main direction of magnetic flux.

[0043] During the energy transfer process, it is desirable to induce the lowest possible voltage in both the positioning signal winding and the energy transfer winding, since otherwise high powers or high field strengths during the energy transfer could lead to the destruction of the corresponding windings. The positioning signal winding according to the invention and the sensor signal winding according to the invention can be arranged in each inductive charging device advantageously such that the conductors forming these windings run mainly parallel to the main direction of the magnetic flux during the energy transfer at each location. It can thus be ensured that the lowest possible voltage is induced in each winding during the energy transfer.

[0044] For this purpose in particular the orientation of the magnetic flux in each magnetic flux guide element of the inductive charging device is important, which may preferably extend radially outwards from the centre of each energy transmission winding.

[0045] Preferably, the first inductive charging apparatus is a mobile inductive charging apparatus located on and / or in the vehicle and the other inductive charging apparatus is a stationary inductive charging apparatus, or the first inductive charging apparatus is a stationary inductive charging apparatus and the other inductive charging apparatus is a mobile inductive charging apparatus located on and / or in the vehicle.

[0046] Advantageously, the positioning signal winding surrounds at least one of the at least one flux guide element, which in the proposed arrangement is responsible for guiding the magnetic field for the energy transfer during the energy transfer process and for guiding the magnetic field for positioning during the positioning process, i.e. the flux guide element here assumes a double function.

[0047] Preferably, the positioning signal winding intersects at least approximately with the winding axis of the energy transmission winding of the first inductive charging device, and the first radial longitudinal direction and the second radial longitudinal direction intersect at least approximately in the center of the energy transmission winding of the other inductive charging device. With this arrangement, the conductors forming the positioning signal winding and the sensor winding run at least approximately parallel to the magnetic field lines that are generated at each location during the energy transmission. This means that the lowest possible voltage is induced in the corresponding winding during the energy transmission, and thus it is ensured that the winding is not destroyed by the high power generated during the energy transmission. Note that the center of the energy transmission winding here refers to an area of ​​several centimeters centered on the geometric center of the energy transmission winding in a plane perpendicular to the winding axis of the energy transmission winding.

[0048] It is advantageous to arrange the sensor windings accordingly, since the two radial longitudinal directions of the two sensor windings are 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 windings are arranged relative to the energy transmission windings in such a way that the lowest possible voltage is induced in the sensor windings during the energy transmission process.

[0049] 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. 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 a voltage is induced compared to the embodiment in which the radial longitudinal directions of the sensor windings cross only in the extension lines, in which a larger voltage 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.

[0050] In this embodiment, it is advantageous if the two sensor windings are arranged point-symmetrically with respect to the centre of the energy transmission winding.

[0051] 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.

[0052] 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°.

[0053] This embodiment is advantageous 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, and thus stabilization elements can be introduced in this area.

[0054] 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.

[0055] In one advantageous variant, the positioning signal winding is arranged spaced apart from the center of the energy transmission winding of the first inductive charging device, in particular near an edge of the energy transmission winding of the first inductive charging device or near an edge of the first inductive charging device.

[0056] Particularly preferably, the positioning signal winding is located at a position farther away from the other inductive charging device than the centre of the energy transmission winding of the first inductive charging device during the positioning process.

[0057] Overall, the positioning method with the vehicle charging system according to the invention not only achieves the maximum range, but also in the case of very small distances, in particular in the case of very small distances between two inductive charging devices in the driving plane, where the sensor winding no longer produces a usable signal. Thus, for example, for areas where two inductive charging devices are located very close to each other, another proximity positioning method can be used, which has a very short range, however. What is important here is that the minimum distance over which the positioning method is possible with the inductive charging device according to the invention is as small as possible. This is achieved by arranging the positioning signal winding further away from the other inductive charging device compared to the center of the energy transmission winding of the first inductive charging device.

[0058] Particularly preferably, the positioning signal winding is formed by a conductor track applied on at least one circuit board, and the first and second sensor windings are formed by conductor tracks applied on at least one circuit board. The realization of the sensor winding with 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 form 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 problematic in terms of construction space. Each circuit board can be shaped and / or dimensioned as desired. Preferably, each circuit board has a shape extending in the direction of the turns 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 several turns, i.e. 7 to 20, in particular 10 to 16, preferably 13 turns. Additionally, the manufacturing process for the circuit board based sensor winding is simpler than that of conventional sensor windings with wound high frequency litz wire conductors.

[0059] In a preferred embodiment, the first sensor winding and / or the second sensor winding and / or the positioning signal winding consists of an upper conductor track on an upper circuit board and a lower conductor track on a lower circuit board. The conductor tracks on the upper circuit board can be connected to the conductor tracks on the lower circuit board in such a way that a spiral winding is produced. In this case, the upper conductor tracks can be arranged primarily above the one or more flux guide elements and the lower conductor tracks can be arranged primarily below the one or more flux guide elements.

[0060] The concepts "above" and "below" or "upper" and "lower" relate primarily to an arrangement of the inductive charging device that extends parallel to the ground. If the charging device is arranged, for example, parallel to a wall, the concepts should 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 present invention.

[0061] 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 during production. 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 and socket strips are used, the plug-in and socket strips can also be connected by a soldering process, which is much simpler than a soldering process without a corresponding plug-in connector device.

[0062] 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 may also be formed 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. Thus, a combination of a rigid circuit board and a flexible circuit board is obtained, which is also called a star-flex circuit board. This is also a variant, which allows for a simpler and more convenient production than in situ soldering.

[0063] The current flowing through each positioning signal winding, preferably with a valid value, is in particular between 130 mA and 390 mA, for example between 195 mA and 325 mA, preferably 260 mA.

[0064] The invention further includes an inductive charging device for a vehicle charging system according to the invention, where the inductive charging device has an energy transmission winding, at least one flux guiding element and at least one positioning signal winding, where the positioning signal winding is configured as a solenoid with a winding axis in the vehicle longitudinal direction or in the target vehicle longitudinal direction, where the flux guiding element is suitable for guiding a magnetic field during an energy transmission process towards or from the inductive charging device, and where the positioning signal winding surrounds at least one of the at least one flux guiding element.

[0065] 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.

[0066] 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.

[0067] Alternatively, the plurality of flux guide elements may be formed as at least approximately orthogonal tiles with an air gap between each flux guide element.

[0068] Important further features and advantages of the invention emerge from the respective dependent claims, the drawings and the corresponding description based on the drawings.

[0069] 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.

[0070] Preferred embodiments of the invention are illustrated in the drawings and explained in detail in the following description, in which like reference numbers refer to identical or similar or functionally identical components. [Brief description of the drawings]

[0071] [Figure 1] FIG. 1 is a highly simplified diagram showing a vehicle equipped with an inductive charging device passing above a stationary inductive charging device. [Diagram 2]1 is a schematic plan view showing an inductive charging device according to the present invention; [Diagram 3] 1 is a schematic plan view of an alternative inductive charging device according to the present invention; [Figure 4] 1A-1C are schematic side views illustrating two alternative inductive charging devices according to the present invention; [Diagram 5] FIG. 2 is a schematic perspective view showing a positioning signal winding according to the present invention; [Figure 6] FIG. 1 is a schematic diagram showing the winding direction. [Figure 7] 1 is a schematic diagram showing a vehicle charging system according to the present invention during a positioning process. [Figure 8] FIG. 2 is a plan view of an inductive charging device according to the present invention with a sensor winding. [Figure 9] FIG. 13 is a plan view of an alternative inductive charging device according to the present invention with a positioning signal winding.

[0072] 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, thereby charging the energy accumulator 3 of the vehicle. The mobile inductive charging device 1a and the stationary inductive charging device 1b together form or are part of a 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.

[0073] 2 shows an inductive charging device 1 according to the invention with an energy transmission winding 4 and a number of flux guide elements 5. The energy transmission winding 4 is configured as a flat coil 10. A positioning signal winding 41 is arranged around the flux guide element 5 and around the energy transmission winding 4. The positioning signal winding 41 is configured as a solenoid 42. The positioning signal winding 41 is arranged here centrally, extending above the center of the energy transmission winding 4.

[0074] In Figure 3 an alternative inductive charging device 1 according to the invention is shown. In contrast to the embodiment shown in Figure 2, here the positioning signal winding 41 is arranged only around the flux guide element 5 and not around the energy transmission winding 4. Furthermore, the positioning signal winding 41 does not extend across the centre of the energy transmission winding 4 here but is arranged close to the edge of the inductive charging device 1.

[0075] Figure 4 shows two different inductive charging devices 1 according to the invention in side views. On the left is shown an embodiment in which the positioning signal winding 41 surrounds the energy transmission winding 4 and the flux guide element 5, i.e. the positioning signal winding 41 is here arranged wound around the energy transmission winding 4, as in Figure 2. On the right is shown an embodiment in which the positioning signal winding 41 surrounds the flux guide element 5 but not the energy transmission winding 4, i.e. the positioning signal winding 41 is here not arranged wound around the energy transmission winding 4, as in Figure 3.

[0076] 5 shows a schematic perspective view of a positioning signal winding 41 according to the invention, which is arranged here around the flux guide element 5. The positioning signal winding 41 is realized as a conductor track 38 on a circuit board 37. At the short vertical edges the conductor track is connected via a flexible element as connecting element 43.

[0077] In Fig. 6 the directions in a winding, in particular the directions defining the radial longitudinal direction 11 in the sensor winding here, are shown diagrammatically. In the example of Fig. 6 the winding is a cylindrical coil with 5 turns. The direction in which the winding is wound over is the winding axis 27. The coil here has a non-square rectangular cross section. The direction along the long side of the rectangle is referred to here as the radial longitudinal direction 11. In the case where the cross section is not rectangular but elliptical, the radial longitudinal direction 11 extends along the main axis of the ellipse.

[0078] In Fig. 7a) a vehicle 2 with a vehicle longitudinal direction 6 with a mobile inductive charging device 1a is shown diagrammatically during a positioning process above a stationary inductive charging device 1b with a target vehicle longitudinal direction 6a. In this example, the vehicle 2 is driving towards the stationary inductive charging device 1b, so that the target vehicle longitudinal direction 6a is the same as the vehicle longitudinal direction 6. The vehicle charging system here comprises the mobile inductive charging device 1a and the stationary inductive charging device 1b. In addition to the energy transmission winding (not shown), a positioning signal winding 41 is also present in the mobile inductive charging device 1a. The positioning signal winding 41 has a winding axis 27 and a radial longitudinal direction 11. The conductors forming the positioning signal winding 41 extend mainly along the radial longitudinal direction 11. The positioning signal winding 41 thus generates a magnetic field during operation, in which the orientation of the magnetic field lines lies for the most part in one plane parallel to the winding axis 27.

[0079] Such an oriented magnetic field is particularly suitable for detecting position or angular deviations with respect to the stationary inductive charging device 1b. The stationary inductive charging device 1b has two sensor windings 9a, 9b in addition to an energy transmission winding (not shown). The two sensor windings each have one radial longitudinal direction 11a and 11b, in which the conductors forming the sensor windings extend primarily. The two sensor windings are arranged in the target position at an angle of 45° to the target vehicle longitudinal direction 6a and thus to the vehicle longitudinal direction 6 and symmetrically to the target vehicle longitudinal direction 6a. The two sensor windings 9a and 9b or their radial longitudinal directions 11a and 11b are therefore mutually perpendicular. Such an arrangement of the windings for positioning purposes is particularly advantageous. The positioning signal winding 41 generates a more or less homogeneous magnetic field with magnetic field lines that extend primarily parallel to the vehicle longitudinal direction in the driving plane. In the sensor windings 9a and 9b, a voltage is induced by the magnetic field of the positioning signal winding 41. The voltage is proportional to the component of the magnetic field perpendicular to the respective radial longitudinal directions 11a, 11b of the sensor windings. If the vehicle travels exactly perpendicular to the stationary inductive charging device 1b, as shown in the schematic diagram on the left, voltages of the same magnitude are induced in the two sensor windings 9a and 9b.

[0080] FIG. 7 b) shows an embodiment in which the positioning signal winding 41 is arranged in the stationary inductive charging device 1b and the sensor windings 9a and 9b are arranged in the mobile inductive charging device 1a. Otherwise, the operation of the embodiment is exactly the same. Here, the case is shown in which the vehicle 2 does not approach the stationary inductive charging device 1b perpendicularly, but with a deviation at an angle of about 45°. The vehicle longitudinal direction 6 and the target vehicle longitudinal direction 6a are therefore at an angle of 45° to each other. In this case, the positioning signal winding 41 generates a magnetic field perpendicular to the first sensor winding 9a. Here, a maximum voltage is induced. Furthermore, the magnetic field generated by the positioning signal winding 41 is approximately parallel to the second sensor winding 9b. Here, a minimum voltage or no voltage is induced at all.

[0081] In Fig. 8 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 in the radial direction around the centre 7 of the energy transmission winding 4. Narrow air gaps are present between the flux guide elements 5 [Error! Link source not found]. The air gaps also extend in the radial direction around the centre 7 and therefore 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 windings 4 are shown with dashed lines, since they are covered by the flux guide elements 5 in the plan view. The energy transmission windings 4 are here flat coils 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 configured here as solenoids, also referred to 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 (or the target vehicle longitudinal direction 6a). 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 intersect or cross 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.

[0082] 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 the charging state, the magnetic field lines in the flux guide element 5 run essentially radially. In FIG. 8, 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.

[0083] In Fig. 9, a preferred alternative embodiment of the inductive charging device 1 with a positioning signal winding 41 is shown. The inductive charging device 1 comprises an energy transmission winding 4 and a positioning signal winding 41. The positioning signal winding 41 is configured as a solenoid 42. The inductive charging device 1 further comprises a number of flux guide elements 5, which are arranged spaced apart from one another by air gaps 27. The positioning signal winding 41 is arranged around the flux guide elements 5 but not around the energy transmission winding 4. The energy transmission winding 4 is configured as a flat coil 10. The flux guide elements 5 are arranged on a mechanical support element 44. The positioning signal winding 41 is arranged in such a way that the support element 44 does not extend in this area, but only the air gaps 27 between the flux guide elements 5 extend in one direction. [Explanation of symbols]

[0084] 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 5 Flux guide element 6 Vehicle longitudinal direction 6a Target vehicle longitudinal direction 7. Center of energy transmission winding 8 Vehicle Charging System 9 Sensor Winding 9a First sensor winding 9b Second sensor winding 10 Flat coil 11 Radial longitudinal direction 11a first radial longitudinal direction 11b Second radial longitudinal direction 12 First Angle 13 Second Angle 14 Magnetic Field Lines 27 Air gap between flux guide elements 28 Winding axis 37 Circuit board 38 Conductor Path 41 Positioning signal winding 42 Solenoid 43 Connection elements between conductor tracks 44 Support element

Claims

1. An inductive charging device (1) for a vehicle charging system (8), comprising an energy transmission winding (4), at least one flux guide element (5), and at least one positioning signal winding (41), The positioning signal winding (41) is configured as a solenoid (42) having a winding axis in the longitudinal direction of the vehicle or in the target longitudinal direction of the vehicle; The magnetic flux guide element (5) is suitable for guiding a magnetic field during an energy transfer process between another inductive charging device (1) and the energy transfer winding (4), the positioning signal winding (41) surrounds at least one of the at least one flux guide element (5) and surrounds the energy transmission winding (4); 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. 3. The inductive charging device (1) according to claim 1 or 2, wherein the positioning signal winding (41) is formed by a conductor path (38) disposed on at least one circuit board (27), preferably by a conductor path (38) disposed on at least two circuit boards (27).

4. 3. The inductive charging device (1) according to claim 1 or 2, wherein the positioning signal winding (41) is configured as a Litz wire, in particular as a high-frequency Litz wire, or as a wire.

5. 3. The inductive charging device (1) according to claim 1, wherein the positioning signal winding (41) at least approximately intersects with the winding axis of the energy transmission winding (4).

6. 3. The inductive charging device (1) according to claim 1 or 2, wherein the positioning signal winding (41) is arranged at a distance from the center of the energy transmission winding (4), in particular near an edge of the energy transmission winding (4) of the inductive charging device (1) or near an edge of the inductive charging device (1).

7. A vehicle charging system (8) comprising a first inductive charging device (1) and another inductive charging device (1), The first inductive charging device (1) has at least one energy transmission winding (4), at least one magnetic flux guide element (5), and at least one positioning signal winding (41); The positioning signal winding (41) is configured as a solenoid (42) having a winding axis in the vehicle longitudinal direction (6) or the target vehicle longitudinal direction (6a), The other inductive charging device (1) comprises at least one energy transmission winding (4), at least one magnetic flux guide element (5), a first sensor winding (9a) having a first radial longitudinal direction (11a), and a second sensor winding (9b) having a second radial longitudinal direction (11b), the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) are arranged at an angle of 70° to 110° to each other, preferably perpendicular to each other, and at an angle of 35° to 55° to the vehicle longitudinal direction (6) or the target vehicle longitudinal direction (6a), preferably at an angle of 45° to the vehicle longitudinal direction (6) or the target vehicle longitudinal direction (6a); Vehicle charging system (8).

8. the first inductive charging device (1) is a mobile inductive charging device (1a) located on and / or in a vehicle (2), and the other inductive charging device (1) is a stationary inductive charging device (1b); or the first inductive charging device (1) is a stationary inductive charging device (1b) and the other inductive charging device (1) is a mobile inductive charging device (1a) located on and / or within a vehicle (2); A vehicle charging system (8) according to claim 7.

9. 9. The vehicle charging system (8) according to claim 7 or 8, wherein the positioning signal winding (41) surrounds at least one of the at least one flux guide element (5).

10. the positioning signal winding (41) at least approximately intersects with the winding axis of the energy transmission winding (4) of the first inductive charging device; 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) of the other inductive charging device; A vehicle charging system (8) according to claim 7 or 8.

11. 9. The vehicle charging system (8) according to claim 7 or 8, wherein the positioning signal winding (41) is arranged at a distance from the center of the energy transmission winding (4) of the first inductive charging device (1), in particular near an edge of the energy transmission winding (4) of the first inductive charging device (1) or near an edge of the first inductive charging device (1).

12. 12. The vehicle charging system (8) of claim 11, wherein the positioning signal winding (41) is positioned at a position farther from the other inductive charging device (1) than the center of the energy transmission winding (4) of the first inductive charging device (1) during a positioning process.

13. The positioning signal winding (41) is formed by a conductor track (38) deposited on at least one circuit board (37), the first sensor winding (9a) and the second sensor winding (9b) are formed by conductor tracks (38) deposited on at least one circuit board (37); A vehicle charging system (8) according to claim 7 or 8.

14. 9. An inductive charging device (1) for a vehicle charging system (8) according to claim 7 or 8, comprising an energy transmission winding (4), at least one flux guide element (5) and at least one positioning signal winding (41), The positioning signal winding (41) is configured as a solenoid (42) having a winding axis in the longitudinal direction of the vehicle or in the target longitudinal direction of the vehicle; the magnetic flux guide element (5) is suitable for guiding a magnetic field during an energy transfer process towards or from the inductive charging device (1), the positioning signal winding (41) surrounds at least one of the at least one flux guide element (5); Inductive charging device (1).

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