Inductive charging device for a vehicle

Abstract

The invention relates to an inductive charging device for a vehicle charging system, comprising an energy transmission winding, at least two flux-guiding elements, a housing and at least one positioning signal winding. The positioning signal winding is in the form of a solenoid having a winding axis in the vehicle longitudinal direction or the target vehicle longitudinal direction, and the flux-guiding elements are suitable for guiding a magnetic field during an energy transmission process which takes place between a further inductive charging device and the energy transmission winding. The positioning signal winding is arranged in a gap between at least two of the at least two flux-guiding elements or in a gap between at least one flux-guiding element and the housing.

Description

[0001] Inductive charging device for a vehicle

[0002] The invention relates to an inductive charging device for a vehicle charging system and a vehicle charging system according to the class of the independent patent claims.

[0003] DE 102018210726 A1 describes a positioning antenna used to position an inductive secondary unit relative to a primary unit. A coil core of the positioning antenna is simultaneously used as the coil core of a charging coil for inductive energy transmission. The positioning antenna can generate or receive a magnetic measuring field for positioning. The positioning antenna comprises several windings of a conductor and is implemented as a cylindrical coil made of ribbon cables. The positioning antenna exhibits advantageous directional properties.

[0004] In this case, the positioning antenna must always be laboriously positioned between the coil core and the charging coil. Furthermore, for the simple positioning antenna with advantageous directional effect, no correspondingly advantageous receiver is shown on the opposite side.

[0005] The present invention proposes an inductive charging device for a vehicle charging system comprising an energy transmission winding, at least two flux guiding elements, a housing and at least one positioning signal winding, wherein the positioning signal winding is designed as a solenoid with a winding axis in the vehicle longitudinal direction or desired vehicle longitudinal direction and the flux guiding elements are suitable for guiding a magnetic field during an energy transmission process which takes place between a further inductive charging device and the energy transmission winding, and the positioning signal winding is arranged in a gap between at least two of the at least two flux guiding elements or in a gap between at least one flux guiding element and the housing.

[0006] Inductive charging involves transferring energy in the form of a magnetic field between two inductive charging devices, usually between a stationary charging device and a mobile inductive charging device.

[0007] The term "inductive charging device" therefore refers to only one of at least two components required for an inductive energy transfer process. During the inductive energy transfer process, a power transfer winding in an inductive charging device generates an alternating magnetic field. This alternating magnetic field induces a voltage in another power transfer winding of another inductive charging device. This additional inductive charging device thus serves as a counterpart for this specific energy transfer process. The energy is transmitted wirelessly and absorbed by inducing a voltage.

[0008] Inductive charging devices can be used for inductive charging of vehicles. In principle, an inductive charging device according to the invention can be used for any type of land, water, or aircraft with an electric or hybrid drive. This applies in particular to passenger cars, buses, and trucks.

[0009] A vehicle charging system comprises at least one mobile inductive charging device and another, usually stationary, inductive charging device. A mobile inductive charging device can, for example, be mounted on and / or in a vehicle.

[0010] An inductive charging device on and / or in the vehicle is therefore suitable for absorbing the magnetic field and making electrical energy available from an energy storage device in the vehicle, for example a battery or accumulator in the vehicle.

[0011] In principle, a vehicle charging system can also be used for bidirectional charging. This allows the vehicle to temporarily feed energy from the energy storage system into the power grid via the vehicle charging system.

[0012] An inductive charging device comprises a power transmission coil that can efficiently receive and / or emit a magnetic field from another power transmission coil during the power transmission process. Power levels of 3 kW to 500 kW can preferably be transmitted, particularly preferably 3 kW to 50 kW.

[0013] In general, a coil is defined here as a component for generating or receiving a magnetic field. A coil can consist of a winding and optionally other elements such as a magnetic core and a coil carrier. A winding is a wound arrangement of a current conductor. A winding can consist of one or more turns, with one turn representing one full circuit of a conductor. In general, however, a winding can also consist of fewer than one turn, for example, 0.5 turns. Of course, a partial number of turns, such as 2.5 turns, is also possible.

[0014] An energy transmission winding can be designed in various forms and can consist, for example, of a high-frequency stranded wire with a diameter between 0.5 mm and 10 mm, preferably made of copper.

[0015] The energy transmission winding can be designed as a flat coil. A flat coil can be a spiral flat coil, in particular a circular spiral flat coil or a rectangular spiral flat coil. A spiral flat coil can be wound in the shape of an Archimedean spiral. The winding shape can be circular (circular spiral flat coil), but other shapes are also possible, such as square or rectangular, or even similar to a rectangle with rounded corners (rectangular spiral flat coil). The spiral lies in a single plane. A flat coil is particularly suitable for transmitting the highest possible power between a stationary inductive charging device and a mobile inductive charging device in a vehicle.

[0016] The power transmission winding can also be arranged in a so-called double-D arrangement or DD arrangement. In a double-D arrangement, the power transmission winding consists of two partial windings, whereby the two partial windings are arranged next to each other, are electrically connected in series and are wound in opposite directions of rotation. The current therefore flows in the two partial windings in opposite directions. This has the particular advantage that the coupling factor between the stationary and mobile coil is higher than in a circular coil system (with otherwise similar boundary conditions). The coupling factor indicates which proportion of the magnetic flux of one coil is captured by the second coil. This means that less reactive power needs to be provided and somewhat higher efficiencies can be achieved.

[0017] The energy transmission winding can alternatively be designed similar to a flat coil or double-D coil, distributed over several levels, for example three levels, similar to a truncated pyramid.

[0018] A flux guide element is designed to guide a magnetic field in a predetermined manner. It has a high magnetic permeability with r >1 , preferably p r >50, especially preferred p r>100. The flux guide element represents a magnetic core for the energy transmission winding. In particular, the high permeability influences the magnetic field in such a way that the greatest possible magnetic flux is transferred to the energy transmission winding. With a flux guide element, the energy transmission winding absorbs a greater magnetic flux than without a flux guide element, all other parameters being equal. A flux guide element can be made of a ferromagnetic or, preferably, a ferrimagnetic material, particularly preferably a ferrite. A flux guide element can preferably be plate-like—in the form of a planar core—and can be arranged in the inductive charging device on the side of the energy transmission winding facing away from the opposite side, i.e., the other inductive charging device.

[0019] In this case, one or more flux guiding elements can serve both as a flux guiding element for the energy transmission winding and as a flux guiding element for the positioning signal winding. A key feature of the invention is that the positioning signal winding does not have to be arranged directly around the corresponding flux guiding element(s). Since an energy transmission winding for inductively charging vehicles is relatively large, it also requires correspondingly large flux guiding elements. These can often not be manufactured in one piece, or can only be manufactured with great difficulty. Therefore, several smaller flux guiding elements are usually arranged next to one another. A small gap then forms between these flux guiding elements. The positioning signal winding can advantageously be arranged in these gaps between flux guiding elements.Furthermore, a small gap is created between the outermost flux guide element and the housing of the energy transmission winding. Alternatively, the positioning signal winding can be arranged in these gaps between the flux guide elements and the housing. The adjacent flux guide elements or the adjacent flux guide element influence the magnetic field of the positioning signal winding sufficiently positively, and there is no need to wrap the flux guide elements directly with the positioning signal winding. This is advantageous because the installation space in inductive charging devices, particularly in the dimension perpendicular to the ground, is very limited. This applies both to a stationary inductive charging device, which is arranged on the ground, for example, and should therefore be as flat as possible, and to a mobile inductive charging device.Arranging the positioning signal winding around flux guide elements would increase the height of the inductive charging device in this dimension. However, if the positioning signal winding is arranged in gaps between flux guide elements or in gaps between the flux guide element and the housing, this does not increase the height of the inductive charging device. At the same time, the flux guide elements located laterally next to the positioning signal winding also act as flux guide elements for the positioning signal windings and thus as flux guide elements during the positioning process. The flux guide elements arranged on one side next to a positioning signal winding also generate or influence the magnetic field of a positioning signal winding arranged in the gap.

[0020] A positioning signal winding can emit a positioning signal during a positioning process. For example, a positioning signal winding can generate an alternating magnetic field with a specific frequency due to an alternating voltage. In principle, an energy transmission winding can also emit a positioning signal, but it is advantageous, as proposed here, to use a separate positioning signal winding to generate a positioning signal. In particular, the positioning signal winding can generate magnetic fields that are more suitable for positioning and, in particular, enable a greater range with the same power. The energy transmission windings are designed to couple as well as possible with their corresponding counterparts. Therefore, they generally do not have a long range with regard to the transmission or reception of magnetic fields in the vehicle's longitudinal direction or.The desired vehicle longitudinal direction is shown. However, this is crucial for a positioning process.

[0021] During positioning, the maximum possible power or the maximum possible magnetic fields of the positioning signal are severely limited. They are significantly lower than is the case during an energy transfer process. During the positioning process, no vehicle is located on the stationary inductive charging device. Therefore, it is possible for a person, for example, to stand on the stationary inductive charging device. To ensure that the magnetic fields remain harmless to a person, they must not exceed certain limit values ​​depending on the frequency range. Depending on the frequency range and the guidelines used in the respective country, these limit values ​​can be flux densities of 27 pT, 15 pT, or 6.25 pT. With a proposed positioning signal winding, it is possible to generate positioning signals that comply with the limit values ​​or reference values ​​while still enabling a long range.

[0022] A solenoid is also called a cylindrical coil or solenoid coil. A solenoid can be wound in the shape of a helix or a cylindrical spiral. However, the winding shape does not necessarily have to be circular, but can also have other shapes, such as square or rectangular, or even similar to a rectangle with rounded corners. The important difference from a flat coil is that the windings are not in a single plane, but rather extend along an axis. However, two or more windings can also run parallel and thus be in the same plane, perpendicular to the axis.

[0023] A stationary inductive charging device has a target vehicle longitudinal direction. This is the direction in which the vehicle's longitudinal direction should be after a successful positioning process.

[0024] If the positioning signal winding is located in a mobile inductive charging device of a vehicle, the winding axis of the positioning signal winding is aligned in the vehicle's longitudinal direction. If the positioning signal winding is located in a stationary inductive charging device, the winding axis of the positioning signal winding is aligned in the desired vehicle longitudinal direction.

[0025] In the proposed arrangement, the flux guide element guides a magnetic field for energy transfer during an energy transfer process and a magnetic field for positioning during a positioning process. Thus, the flux guide element performs a dual function, which is particularly advantageous because it allows for efficient use of material and installation space.

[0026] An inductive charging device is advantageously arranged in a housing. A housing does not have to enclose an inductive charging device on all sides, but can also be open on one side, for example. The housing protects the inductive charging device from environmental influences, such as mechanical impact or water. A housing can be made of plastic, for example. A housing enables the inductive charging device to be manufactured as a prefabricated unit. The housing of a stationary inductive charging device is subject to particularly high demands in terms of mechanical stability, as it must be able to withstand being driven over by a vehicle, for example.

[0027] The arrangement of the positioning signal winding in a gap between at least two of the at least two flux guiding elements or in a gap between at least one flux guiding element and the housing means here that the positioning signal winding extends at least partially and at least in part of the gap. In this case, the gap can be longer than the positioning signal winding or the positioning signal winding can be longer than the gap or the positioning signal winding can be the same length as the gap. A gap can be formed between two flux guiding elements. A gap can also extend over several flux guiding elements. For example, a gap can be formed between two times two flux guiding elements. A gap can be formed between two flux guiding elements and a housing.A gap can therefore continue after a gap between two additional flux guide elements or between another flux guide element and a housing. An inventive arrangement of the positioning signal winding in a gap is advantageous because the positive influence of the flux guide element on the magnetic field of the positioning signal winding can be utilized without requiring additional installation space for the flux guide element.

[0028] Preferably, the positioning signal winding can extend over the entire width of the energy transmission winding.

[0029] Particularly preferably, the positioning signal winding can be arranged around the entire width of the inductive charging device in order to cover as large an area as possible and thus to be able to generate a magnetic field that is as homogeneous as possible.

[0030] An inductive charging device according to the invention is preferably a mobile inductive charging device which is arranged on and / or in a vehicle or a stationary inductive charging device.

[0031] A stationary inductive charging device is the non-mobile part of a vehicle charging system, i.e. the part that does not move with the vehicle.

[0032] A stationary inductive charging device can preferably be located on, at, or in a floor. This can be an inductive charging device mounted on the ground or an inductive charging device sunk into a subsurface or into the ground. A floor can be a roadway, a parking lot surface, a garage floor, or the floor of a parking garage or other building. However, a stationary inductive charging device can also be located on walls or similar structures.

[0033] It is also possible for a stationary inductive charging device to be used for a dynamic inductive charging process. During a dynamic inductive charging process, a vehicle's energy storage device can be charged while the vehicle is moving. For example, in this case, the stationary inductive charging device can extend along the roadway, under, in, or on the road surface. During dynamic inductive charging, the positioning process is not a time-limited parking process, but rather extends over a longer period of time and is more similar to a lane-keeping process. However, here too, advantageous positioning of the mobile inductive charging device relative to the stationary inductive charging device is crucial.

[0034] A mobile inductive charging device can be installed on and / or in a vehicle. Generally speaking, this refers to the part of a vehicle charging system that moves with the vehicle.

[0035] Preferably, the positioning signal winding is formed by conductor tracks which are applied to at least one printed circuit board, preferably to at least two printed circuit boards.

[0036] Here, the turns of a positioning signal winding are realized in the form of conductor tracks on printed circuit boards.

[0037] The conductor tracks can be made of copper, for example.

[0038] The conductor tracks can be multi-layered, preferably double-layered. The cross-section of such a conductor track can be adapted much more flexibly to the constraints imposed by the limited installation space. In particular, it is possible to design the cross-section of the conductor tracks as a rectangle with a low height, with the height in this case being perpendicular to the substrate.

[0039] Implementing a positioning signal winding using conductive tracks on printed circuit boards makes it possible to significantly reduce the height of the positioning signal winding compared to conventional windings, such as those based on high-frequency stranded wires. This form of positioning signal winding therefore requires less installation space, particularly in the dimension along the winding axis of the power transmission winding, which is the most critical in terms of installation space.

[0040] A positioning signal winding can be arranged around a support element. A support element can be made of an electrically non-conductive and magnetically neutral material. A support element can be arranged in a gap between two flux guide elements or in a gap between a flux guide element and the housing. A support element can be formed separately or be part of a larger support element, for example a support element that carries the flux guide elements. A support element can have a lower height than the flux guide elements between or next to which it is arranged. Height here means the extension in the dimension parallel to the walls of the gap and perpendicular to the main extension plane of the flux guide elements.

[0041] It is also conceivable not to use a carrier element, but to fill the gap with a potting or adhesive material and to arrange the positioning signal winding in it.

[0042] Preferably, at least two circuit boards are used for a positioning signal winding, wherein one circuit board can be arranged on one side of a carrier element, for example above, and another circuit board can be arranged on another side of a carrier element, for example below. The conductor tracks on the two circuit boards are connected by corresponding flexible or inflexible connections and thus form a winding. The manufacturing process for a circuit board-based winding is also simpler compared to conventional windings with wound high-frequency stranded conductors. In an alternative advantageous embodiment, the positioning signal winding is designed as a stranded wire, in particular as a high-frequency stranded wire or as a wire.

[0043] A high-frequency stranded wire consists of several mutually insulated wires. This offers advantages because at high frequencies, the current flows primarily near the surface of a conductor, and the implementation with many individual conductors ensures the largest possible conductor surface area.

[0044] The term "wire" refers to the implementation as an insulated single wire, which is then wound in multiple turns. One advantage of implementing the positioning signal winding as a high-frequency stranded wire or as a wire is that it is a proven and simple manufacturing method.

[0045] For this embodiment, the support structure can be designed with corresponding grooves or grooves or the like so that the high-frequency strand or wire does not slip on the support element.

[0046] Alternatively, it is possible to glue the high-frequency strand or wire to the carrier element to prevent slipping.

[0047] A spacer structure can also be used to ensure a defined distance between the individual turns of the positioning signal winding.

[0048] Preferably, the positioning signal winding at least approximately crosses at least one of the winding axes of the energy transmission winding.

[0049] Depending on the shape of the power transmission winding, it is not always possible to directly assign a winding axis. In this case, the winding axis is assumed to be located approximately at the geometric center of the power transmission winding. It is also possible for a power transmission winding to have multiple winding axes. This is the case, for example, with a power transmission winding in a double-D configuration, which has two winding axes for the two partial windings. In this case, the condition is that the positioning signal winding crosses at least one of the power transmission winding axes.

[0050] Such an arrangement is advantageous because as little voltage as possible should be induced in the positioning signal winding during an energy transfer process, since the high power levels that occur during energy transfer could otherwise destroy or damage the positioning signal winding. The main direction of the magnetic flux in or near the at least one flux guide element is crucial for this. The main direction of the magnetic field lines at the respective location refers to the direction in which the magnetic field lines extend primarily in or near the flux guide element. It is particularly important here that - if the flux guidance is provided by several flux guide elements arranged next to one another and separated by gaps - the magnetic field also develops in the gaps.The direction of the magnetic field lines largely corresponds to the direction of the magnetic field lines in the adjacent flux guide elements. Here, the magnetic field lines run primarily radially. Thus, arranging the positioning signal winding approximately through the center of the power transmission winding, i.e., crossing the winding axis of the power transmission winding, is advantageous, since in this case the conductors of the positioning signal winding run at least approximately parallel to the magnetic field lines, and therefore only a very low voltage is induced.

[0051] In an alternative preferred embodiment, the positioning signal winding is arranged at a distance from the center 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. In this embodiment, the positioning signal winding is shifted to the position at which the positioning signal winding intersects the winding axis of the energy transmission winding. The positioning signal winding is therefore not arranged centrally with respect to the energy transmission winding and also not centrally in the inductive charging device. Compared to the center of the energy transmission winding, the positioning signal winding is located closer to or further away from the inductive charging device that forms the counterpart. The positioning signal winding is spaced towards an edge from the center of the energy transmission winding."Edge" here simply means that the energy transfer winding or the inductive charging device ends there and makes no statement about the shape (e.g., whether rounded or not) of this edge. In particular, in a mobile inductive charging device, this refers to a front or rear edge, taking the vehicle's longitudinal direction into account, and in a stationary inductive charging device, it refers to a front or rear edge, taking the vehicle's desired longitudinal direction into account. For example, the positioning signal winding can be arranged near an edge or, for example, halfway between the edge and the center of the energy transfer winding.

[0052] An arrangement at a distance from the center of the energy transmission winding has the advantage that a position for the positioning signal winding can be found here in which no further components, such as support elements, make arrangement difficult.

[0053] Furthermore, an arrangement spaced apart from the center of the energy transmission winding is also advantageous for a positioning method. If the positioning signal winding is located closer to the inductive charging device that forms the counterpart than 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 that forms the counterpart than the center of the energy transmission winding, it is still possible to carry out a positioning method down to a smaller minimum distance between the two inductive charging devices. In general, there is not only a maximum range for a positioning method with a vehicle charging system according to the invention, but also that even at very small distances between the two inductive charging devices, no usable signal is received from the sensor windings.Therefore, for example, in areas where the two inductive charging devices are very close to each other, another close-range positioning method can be used. However, this method has a very short range. Therefore, it is important that the minimum distance up to which a positioning method is possible with an inductive charging device according to the invention is as small as possible. This is achieved by arranging the positioning signal winding farther away from the inductive charging device, which forms the counterpart, compared to the center of the energy transmission winding.

[0054] Furthermore, a vehicle charging system with a first inductive charging device and a further inductive charging device is proposed,wherein the first inductive charging device has at least one energy transmission winding and at least two flux guiding elements and at least one positioning signal winding, and the positioning signal winding is designed as a solenoid with a winding axis in the vehicle longitudinal direction or the desired vehicle longitudinal direction, and the positioning signal winding is arranged in a gap between at least two of the at least two flux guiding elements or in a gap between at least one flux guiding element and a housing, and the further inductive charging device has at least one energy transmission winding and at least one flux guiding element and a first sensor winding with a first radial longitudinal direction and a second sensor winding with a second radial longitudinal direction, and the first radial longitudinal direction and the second radial longitudinal direction are at an angle between 70° and 110° to one another,preferably perpendicular to each other and at an angle between 35° and 55° to the vehicle longitudinal direction or to the desired vehicle longitudinal direction, preferably at a 45° angle to the vehicle longitudinal direction or to the desired vehicle longitudinal direction.

[0055] In general, a winding extends in at least two dimensions around an axis. The main extension direction perpendicular to the winding axis is referred to here as the radial longitudinal direction. Thus, for a winding with a rectangular, non-square cross-section, the main extension direction runs along or parallel to the longer side of the rectangle. For a winding with an elliptical cross-section, the radial longitudinal direction runs along or parallel to the main axis of the ellipse. The radial longitudinal direction of a sensor winding according to the invention can preferably lie in a plane that extends parallel to the ground.

[0056] Such a design and arrangement of the positioning signal winding and the sensor windings is advantageous for both a positioning process and a power transmission process. The design of the positioning signal winding as a solenoid with a winding axis in the vehicle's longitudinal direction or in the desired vehicle's longitudinal direction generates a magnetic field with a main direction of the magnetic field lines in the vehicle's longitudinal direction or in the desired vehicle's longitudinal direction. This has the advantage that this design enables a significantly greater range for positioning than would be the case with a positioning signal generated by a power transmission winding with the same power or the same magnetic field strength. Furthermore, such an orientation of the magnetic field is also particularly well suited to enabling the simplest possible detection of a positional deviation or an angular deviation in the sensor windings.

[0057] Particularly preferably, the positioning signal winding is designed such that it has a particularly large extension in the travel plane and perpendicular to the vehicle longitudinal direction or to the desired vehicle longitudinal direction.

[0058] For example, the positioning signal winding can extend across the entire width of a power transmission winding or across the entire width of an inductive charging device. This achieves a largely homogeneous magnetic field with a main direction of magnetic flux in the vehicle's longitudinal direction or the desired vehicle's longitudinal direction.

[0059] A proposed arrangement of the sensor windings is also advantageous for an optimized positioning process. If the sensor windings are arranged symmetrically to the vehicle's longitudinal direction or to the desired vehicle longitudinal direction, an angular deviation relative to a homogeneous magnetic field with a clear main direction of the magnetic flux can be determined by simply comparing the voltages induced in the two sensor windings.

[0060] During an energy transfer process, as little voltage as possible should be induced in both the positioning signal winding and the energy transfer winding, since the high power or field strengths during energy transfer could otherwise lead to destruction of the corresponding windings.

[0061] A positioning signal winding according to the invention and sensor signal windings according to the invention can advantageously be arranged in the respective inductive charging device such that the conductors forming these windings run primarily parallel to the main direction of the magnetic flux during energy transfer at the respective location. This ensures that the lowest possible voltage is induced in the respective windings during energy transfer.

[0062] In particular, the orientation of the magnetic flux in or near the respective flux guide elements of the inductive charging devices is crucial. This can preferably run radially outward from the center of the respective energy transmission winding.

[0063] It is preferred that the first inductive charging device is a mobile inductive charging device which is arranged on and / or in a vehicle, and the further inductive charging device is a stationary inductive charging device, or that the first inductive charging device is a stationary inductive charging device and the further inductive charging device is a mobile inductive charging device which is arranged on and / or in a vehicle.

[0064] Preferably, the positioning signal winding at least approximately crosses at least one 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 further inductive charging device.

[0065] A power transmission winding in a double-D configuration has two winding axes. A positioning signal winding can be arranged so that it at least approximately crosses both winding axes or at least approximately crosses one of the two winding axes.

[0066] This arrangement ensures that the conductors forming the positioning signal winding and the sensor windings run at least approximately parallel to the magnetic field lines that develop at the respective location during energy transfer. This ensures that the lowest possible voltage is induced in the corresponding windings during energy transfer, preventing them from being destroyed by the high power levels generated during energy transfer. The center of the energy transfer winding refers to the area a few centimeters around the geometric center of the energy transfer winding in the plane perpendicular to the winding axis of the energy transfer winding.

[0067] A corresponding arrangement of the sensor windings is advantageous because the two radial longitudinal directions of the two sensor windings are tilted to the longitudinal direction of the vehicle by an angle that is advantageous for optimal detection of a positional deviation between the vehicle and the stationary inductive charging device.

[0068] In addition, the sensor windings are arranged in relation to the energy transmission winding in such a way that the lowest possible voltages are induced in the sensor windings during the energy transmission process.

[0069] In one embodiment, the two sensor windings intersect at least approximately in the center of the energy transfer winding. The fact that only the radial longitudinal directions of the two sensor windings intersect approximately in the center of the energy transfer winding is a weaker condition. In this case, it is also possible for the two sensor windings to be relatively short and arranged in a "V" shape. If these two sensor windings are notionally extended in their radial longitudinal direction, these radial longitudinal directions intersect, but not the two sensor windings themselves. The fact that the two sensor windings themselves intersect is a stricter condition. In this case, the sensor windings are longer than in a "V"-shaped arrangement and actually intersect. The arrangement is "X"-shaped.In this embodiment, the sensor windings have a larger area in which voltage is induced than in embodiments where only the radial longitudinal directions of the sensor windings intersect in the extension, and more voltage can be induced. In this case, an actual crossing of the sensor windings occurs, rather than merely a crossing in the extension of the sensor windings.

[0070] It is advantageous if, in this embodiment, the two sensor windings are arranged point-symmetrically to the center of the energy transmission winding.

[0071] In an alternative preferred embodiment, the inductive charging device has at least four sensor windings, two of which are arranged on opposite sides of the center of the energy transmission winding and all radial longitudinal directions run 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 45°, with the longitudinal direction of the vehicle.

[0072] Thus, the four sensor windings are arranged like a cross around the center of the energy transmission winding, whereby the center of the energy transmission winding itself is free of a sensor winding.

[0073] Preferably, the four sensor windings can be arranged radially at equal intervals around the center of the energy transmission winding and can be arranged at approximately the same angle to one another. For example, the angle between the respective radial longitudinal direction of a sensor winding and the radial longitudinal direction of the adjacent sensor winding can always be 45° + / - 10°, preferably 45°.

[0074] This embodiment is advantageous over the embodiment with only two sensor windings, as this arrangement allows for more efficient use of the installation space and allows for more windings per sensor winding. Overall, more voltage is induced. Compared to the embodiment with two intersecting sensor windings, it also offers the advantage that the center of the energy transmission winding remains free of a sensor winding, allowing stabilizing elements to be incorporated in this area.

[0075] The four sensor windings can be interconnected, preferably in series. Particularly preferred is the two diagonally opposite sensor windings being interconnected in series.

[0076] In an advantageous variant, the positioning signal winding is arranged at a distance 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.

[0077] Particularly preferably, the positioning signal winding is arranged further away from the further inductive charging device during a positioning process than the center of the energy transmission winding of the first inductive charging device.

[0078] In general, there is not only a maximum range for a positioning method using a vehicle charging system according to the invention, but also that even at very small distances, particularly at very small distances in the travel plane, no usable signal is received from the sensor windings between the two inductive charging devices. Therefore, for example, in the area in which the two inductive charging devices are very close to each other, another short-range positioning method can be used. However, this has a very short range. In this respect, it is important that the minimum distance up to which a positioning method is possible with an 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 further inductive charging device compared to the center of the energy transmission winding of the first inductive charging device.

[0079] In an alternative preferred embodiment, the positioning signal winding is arranged closer to the additional inductive charging device during a positioning process than the center of the energy transmission winding of the first inductive charging device. Depending on the precise conditions and requirements, this embodiment can also be advantageous. If the positioning signal winding is arranged such that it is closer to the additional inductive charging device during the positioning process, the system has a greater range.

[0080] Particularly preferably, the positioning signal winding is formed by conductor tracks applied to at least one printed circuit board, and the first sensor winding and the second sensor winding are formed by conductor tracks applied to at least one printed circuit board. Implementing a sensor winding using conductor tracks on printed circuit boards makes it possible to significantly reduce the height of the sensor winding compared to conventional windings, for example, those based on high-frequency stranded wires. This form of sensor winding therefore requires less installation space, particularly in the dimension along the winding axis of the energy transmission winding, which is the most critical in terms of installation space. The respective printed circuit board can be of any shape and / or dimension.Preferably, the respective circuit board has a shape extending in the direction of the windings and a width that is transverse to the longitudinal direction of the windings, between 20 mm and 60 mm, in particular between 30 mm and 50 mm, preferably between 40 mm. This allows multiple windings, in particular adjacent to one another, to be located thereon. Preferably, the respective circuit board has a plurality of windings between 7 and 20, in particular between 10 and 16, preferably 13. The manufacturing process for a circuit board-based sensor winding is also simpler compared to conventional sensor windings with wound high-frequency stranded conductors.

[0081] In a preferred embodiment, the first sensor winding and / or the second sensor winding and / or the positioning signal winding consist of upper conductive tracks on an upper circuit board and of lower conductive tracks on a lower circuit board.

[0082] The conductor tracks on the upper circuit board can be connected to the conductor tracks on the lower circuit board to create a spiral winding.

[0083] The upper conductor track can be arranged predominantly above one or more flux guiding elements or support elements and the lower conductor track can be arranged predominantly below one or more flux guiding elements or support elements.

[0084] The terms "above" and "below" or "upper" and "lower" refer to the arrangement of an inductive charging device that extends primarily parallel to the ground. If, for example, a charging device is arranged parallel to a wall, the terms continue to be understood as "on one side of the flux guide elements / support elements" and "on the other side of the flux guide elements / support elements," without departing from the scope of the invention.

[0085] Preferably, the upper conductor tracks are connected to the lower conductor tracks via through-plated and / or surface-soldered plug and socket strips.

[0086] Using plug and socket connectors, it's possible to create a connection without soldering the conductors during assembly of the inductive charging device. This offers significant advantages during manufacturing. This is especially true for the version with through-hole plug and socket connectors.

[0087] However, the use of plug and socket strips can also involve a soldering process when using surface-mounted or surface-soldered (surface-mounted device, SMD) plug and socket strips, which is, however, significantly simpler than a soldering process without the corresponding plug and socket devices.

[0088] In an alternative preferred variant, the upper conductor tracks are connected to the lower conductor tracks via flexible circuit boards.

[0089] The upper and lower circuit boards can still be designed as rigid circuit boards. The flexible circuit boards provide the connection via the vertical end faces and thus complete the winding for the coil around at least one flux guide element. This creates a combination of rigid and flexible circuit boards. This combination is also known as rigid-flex circuit boards. This is also a variant that allows for simpler and more suitable manufacturing than on-site soldering.

[0090] The magnetic flux flowing through the respective positioning signal winding, preferably the effective value, is in particular between 130 mA and 390 mA, for example between 195 mA and 325 mA, preferably 260 mA. The magnetic flux is the electric current multiplied by the unitless number of turns. A magnetic flux of 260 mA corresponds, for example, to an electric current of 260 mA for one turn. In general, however, with a number of turns greater than 1, the magnetic flux can be a multiple of the electric current. Previously, the unit of magnetic flux was specified in ampere-turns or ampere-turns. Since the number of turns or turns is unitless, the unit is now only specified in amperes.The invention further includes an inductive charging device for a vehicle charging system according to the invention, wherein the inductive charging device has an energy transmission winding and at least two flux guiding elements and at least one positioning signal winding, wherein the positioning signal winding is designed as a solenoid with a winding axis in the vehicle longitudinal direction or desired vehicle longitudinal direction and the flux guiding elements are suitable for guiding a magnetic field during an energy transmission process to or from the inductive charging device and the positioning signal winding is arranged in a gap between at least two of the at least two flux guiding elements or in a gap between at least one flux guiding element and a housing.

[0091] In a further preferred embodiment, a plurality of flux guide elements are arranged radially around the center of the energy transmission winding, with gaps between the flux guide elements also extending radially.

[0092] From a manufacturing perspective, it is either impossible or very difficult to produce a large flux guide element that covers the entire surface of the energy transfer coil or even extends beyond it. Therefore, several smaller flux guide elements must usually be placed next to one another. In this case, it is possible to use rectangular flux guide elements. These are easier to manufacture. There are then always smaller gaps between the flux guide elements. These can negatively influence the guidance of the magnetic field. With rectangular flux guide elements, the gaps between the flux guide elements will always run partly perpendicular to or at an angle to the magnetic field lines. It is therefore advantageous if the gaps between the flux guide elements also run radially and thus influence the guidance of the magnetic field as little as possible.Alternatively, several flow guidance elements can be designed as at least approximately rectangular tiles with gaps between the flow guidance elements.

[0093] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0094] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0095] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0096] It shows, schematically

[0097] Fig. 1 is a highly simplified representation of a vehicle with an inductive charging device above a stationary inductive charging device,

[0098] Fig. 2 is a sectional view of an inductive charging device for a vehicle charging system,

[0099] Fig. 3 is a schematic plan view of an inductive charging device according to the invention,

[0100] Fig. 4 is a schematic plan view of an alternative inductive charging device according to the invention, Fig. 5 is a schematic plan view of a further alternative inductive charging device according to the invention,

[0101] Fig. 6 schematic perspective view of a positioning signal winding according to the invention,

[0102] Fig. 7 is a schematic representation of the directions in a winding,

[0103] Fig. 8 is a schematic representation of an inventive

[0104] Vehicle charging system during the positioning process,

[0105] Fig. 9 Top view of an inductive charging device according to the invention with sensor windings.

[0106] Fig. 1 shows a mobile inductive charging device 1a, which is arranged on a vehicle 2 with an energy storage device 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, and the energy storage device of the vehicle 3 can thereby be charged. 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, it is also possible to operate the vehicle charging system 8 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 arranged on the ground in Fig. 1 can alternatively also be arranged sunk into the roadway (not shown here).In a recessed arrangement, the inductive charging device 1b can be covered by certain layers of the road surface or can be flush with the road surface.

[0107] Fig. 2 shows a lateral section through an inductive charging device 1, 1a, which includes several flux guiding elements 5 and an energy transmission winding 4, 4a and is mounted on a vehicle 2. A corresponding arrangement exists for a stationary inductive charging device 1b, except that it is arranged on or in a subsurface instead of on a vehicle 2 (not shown).

[0108] Fig. 3 shows an inductive charging device 1 according to the invention with an energy transmission winding 4 and several flux guiding elements 5. The energy transmission winding 4 is designed as a double-D coil 15. A positioning signal winding 41 is arranged in a gap 27 between two flux guiding elements 5. The positioning signal winding has a winding axis 28 in the vehicle longitudinal direction 6 or the desired

[0109] Vehicle longitudinal direction 6a. The energy transmission winding 4, which in plan view is formed by the flux guide elements 5 and the

[0110] The position signal winding 41 is concealed by a dashed line. The position signal winding 41 is designed as a solenoid 42. The position signal winding 41 extends across the entire width of the flux guide elements 5. This is advantageous because the largest possible width of the position signal winding 41 generates the most homogeneous magnetic field possible, which in turn is particularly suitable for a positioning process.

[0111] Fig. 4 shows an alternative inductive charging device 1 according to the invention. In contrast to the embodiment in Fig. 2, the positioning signal winding 41 is not arranged over the entire width of the flux guide elements 5, but the positioning signal winding 41 is narrower than the flux guide elements 5 which form the gap 27 and thus the positioning signal winding 41 does not extend over the entire length of the gap 27. Fig. 5 shows a further alternative embodiment of an inductive charging device 1 according to the invention. Here, the housing 17 is shown, which has been omitted in Fig. 3 and Fig. 4 for reasons of clarity. In this embodiment, the positioning signal winding 41 is arranged in a gap 26 between the housing 17 and a flux guide element 5.Here too, the flux guiding element 5 still influences the magnetic field of the positioning signal winding 41 sufficiently positively to function as a flux guiding element 5 during a positioning process.

[0112] Fig. 6 shows a schematic perspective view of a positioning signal winding 41 according to the invention. Here, it is arranged around a support element 16. The positioning signal winding 41 is implemented as conductor tracks 38 on printed circuit boards 37. At the vertical short edges, the conductor tracks are connected via flexible elements as connecting elements 43.

[0113] Fig. 7 schematically shows how the directions, in particular the radial longitudinal direction 11, are defined in a winding, particularly in a positioning signal winding 41. The example in Fig. 7 shows a cylindrical coil with five turns. The direction along which the winding was wound is the winding axis 28. The coil here has a rectangular, not square, cross-section. The direction along the longer side of the rectangle is referred to here as the radial longitudinal direction 11. If the cross-section is not rectangular, but elliptical, the radial longitudinal direction 11 runs along the main axis of the ellipse.

[0114] Fig. 8 a) schematically shows a vehicle 2 with a vehicle longitudinal direction 6 with a mobile inductive charging device 1a during a positioning process above a stationary inductive charging device 1b with a target vehicle longitudinal direction 6a. In the present case, the vehicle 2 is driving towards the stationary inductive charging device 1b and the target vehicle longitudinal direction 6a is thus the same as the vehicle longitudinal direction 6. The vehicle charging system includes the mobile inductive charging device 1a and the stationary inductive charging device 1b. In addition to the energy transmission winding (not shown), the mobile inductive charging device 1a also contains a positioning signal winding 41. The positioning signal winding 41 has a winding axis 28 and a radial longitudinal direction 11. The conductors which form the positioning signal winding 41 extend mainly along the radial longitudinal direction 11.During operation, the positioning signal winding 41 thus generates a magnetic field, the orientation of the magnetic field lines being largely parallel to the winding axis 28 in a plane.

[0115] A magnetic field aligned in this way is particularly suitable for detecting a positional deviation or an angular deviation with respect to the stationary inductive charging device 1b. In addition to the energy transmission winding (not shown), the stationary inductive charging device 1b has two sensor windings 9a and 9b. Both sensor windings each have a radial longitudinal direction 11a and 11b, in which the conductors forming the sensor windings mainly extend. Both sensor windings are arranged at an angle of 45° to the desired vehicle longitudinal direction 6a and thus to the vehicle longitudinal direction 6 in the target position and symmetrically to the desired vehicle longitudinal direction 6a. The two sensor windings 9a and 9b, or their radial longitudinal directions 11a and 11b, are thus perpendicular to one another. This arrangement of the windings is particularly advantageous for positioning.The positioning signal winding 41 generates a fairly homogeneous magnetic field with magnetic field lines that extend primarily in the travel plane and parallel to the vehicle's longitudinal direction. A voltage is induced in the sensor windings 9a and 9b by the magnetic field of the positioning signal winding 41. This voltage is proportional to the component of the magnetic field that is perpendicular to the respective radial longitudinal direction 11a, 11b of the sensor winding. If the vehicle travels exactly perpendicularly toward the stationary inductive charging device 1b, as shown in the left sketch, an equal voltage is induced in both sensor windings 9a and 9b.

[0116] Fig. 8b) 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. The functioning of this embodiment is otherwise exactly the same. Shown here is a case in which the vehicle 2 does not drive perpendicularly towards the stationary inductive charging device 1b, but deviates from it at an angle of approximately 45°. The vehicle's longitudinal direction 6 and the desired vehicle longitudinal direction 6a are therefore at an angle of 45° to one another. In this case, the positioning signal winding 41 generates a magnetic field which is perpendicular to the first sensor winding 9a. Here, a maximum voltage is induced. The magnetic field generated by the positioning signal winding 41 is also approximately parallel to the second sensor winding 9b. Here, a minimal voltage or no voltage is induced.

[0117] Fig. 9 shows a plan view of an inductive charging device 1 according to the invention. This can be a mobile inductive charging device 1a or a stationary inductive charging device 1b. In the present exemplary embodiment, eight flux guiding elements 5 are shown, which are arranged radially around the center 7 of the energy transmission winding 4 in the plane. Narrow gaps 27 are located between the flux guiding elements 5. The gaps also run radially around the center 7, thus the gaps run approximately in the main direction of the magnetic field lines (three magnetic field lines 14 are symbolically indicated here) that arise during energy transmission in the flux guiding elements 5. The energy transmission winding 4, which is concealed by the flux guiding elements 5 in the plan view, is indicated by dashed lines. The energy transmission winding 4 is a flat coil 10 here.A first sensor winding 9, 9a is arranged around one of the flux guide elements 5, and a second sensor winding 9, 9b is arranged around another flux guide element 5. Alternatively, it is also possible to arrange the sensor windings 9, 9a, 9b in a gap 27 between the flux guide elements 5 (not shown). The sensor windings are designed here as a solenoid, also called a cylindrical coil. The first sensor winding 9a is arranged axially symmetrically to the second sensor winding 9b with respect to the vehicle's longitudinal direction 6 (or the desired 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 the same size as the angle 13 between the second radial longitudinal direction 11b and the longitudinal direction of the vehicle.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 outwards from the center 7 of the energy transmission winding 4.

[0118] 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 guiding elements 5 perform the function of flux guiding. In the charging state, the field lines of the magnetic field run approximately radially in them. Three magnetic field lines 14 are symbolically indicated in Fig. 3. Since the first radial longitudinal direction 11a and the second radial longitudinal direction 11b are also aligned radially and thus at least approximately parallel to the magnetic field lines 14, only relatively little or no voltage is induced in the first sensor winding 9a and the second sensor winding 9b. This is important, since the high power levels of the energy transfer and thus the high flux densities could otherwise easily lead to the destruction of the sensor windings.Additional effort to prevent the destruction of the arrangement is therefore unnecessary. Reference symbol.

[0119] 1 inductive charging device

[0120] 1a mobile inductive charging device

[0121] 1 b stationary inductive charging device

[0122] 2 vehicles

[0123] 3 Vehicle energy storage

[0124] 4 Energy transmission winding

[0125] 5 Flow guide element

[0126] 6 Vehicle longitudinal direction

[0127] 6a Target vehicle longitudinal direction

[0128] 7 Center of the energy transmission winding

[0129] 8 Vehicle charging system

[0130] 9 Sensor winding

[0131] 9a first sensor winding

[0132] 9b second sensor winding

[0133] 10 circular flat coil

[0134] 11 radial longitudinal direction

[0135] 11 a first radial longitudinal direction

[0136] 11 b second radial longitudinal direction

[0137] 12 first angle

[0138] 13 second angle

[0139] 14 magnetic field lines

[0140] 15 Double-D Coil

[0141] 16 support element

[0142] 17 housings

[0143] 26 Gap between flux guide element and housing

[0144] 27 Gap between flow guide elements

[0145] 28 Winding axis PCB Conductor tracks Positioning signal winding Solenoid Connecting element between conductor tracks

Claims

Claims 1. Inductive charging device (1) for a vehicle charging system (8) with an energy transmission winding (4), at least two flux guiding elements (5), a housing (17) and at least one positioning signal winding (41), wherein - the positioning signal winding (41) is designed as a solenoid (42) with a winding axis (28) in the vehicle longitudinal direction or desired vehicle longitudinal direction and - the flux guiding elements (5) are suitable for guiding a magnetic field during an energy transfer process which takes place between a further inductive charging device (1) and the energy transfer winding (4), and - the positioning signal winding (41) is arranged in a gap (27) between at least two of the at least two flux guiding elements (5) or in a gap (26) between at least one flux guiding element (5) and the housing (17).

2. Inductive charging device (1) according to claim 1, characterized in that - the inductive charging device (1) is a mobile inductive charging device (1a) which is arranged on and / or in a vehicle (2), or that - the inductive charging device (1) is a stationary inductive charging device (1b).

3. Inductive charging device (1) according to claim 1 or claim 2, characterized in that the positioning signal winding (41) is Conductor tracks (38) which are applied to at least one printed circuit board (37), preferably to at least two printed circuit boards (37).

4. Inductive charging device (1) according to claim 1 or claim 2, characterized in that the positioning signal winding (41) is designed as a stranded wire, in particular as a high-frequency stranded wire or as a wire.

5. Inductive charging device (1) according to one of the preceding claims, characterized in that the positioning signal winding (41) at least approximately crosses at least one of the winding axes of the energy transmission winding (4).

6. Inductive charging device (1) according to one of claims 1-4, characterized in that 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. Vehicle charging system (8) with a first inductive charging device (1) and a further inductive charging device (1 ), wherein - the first inductive charging device (1) has at least one energy transmission winding (4) and at least two flux guiding elements (5) and at least one positioning signal winding (41) and - the positioning signal winding (41) is designed as a solenoid (42) with a winding axis (28) in the vehicle longitudinal direction (6) or desired vehicle longitudinal direction (6a) and - the positioning signal winding (41) in a gap (27) between at least two of the at least two flux guide elements (5) is arranged or is arranged in a gap (26) between at least one flux guide element (5) and a housing (17) and - the further inductive charging device (1) has at least one energy transmission winding (4) and at least one flux guiding element (5) and a first sensor winding (9a) with a first radial longitudinal direction (11a) and a second sensor winding (9b) with a second radial longitudinal direction (11b) and - the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) are arranged at an angle between 70° and 110° to one another, preferably perpendicular to one another and at an angle between 35° and 55° to the vehicle longitudinal direction (6) or to the desired vehicle longitudinal direction (6a), preferably at a 45° angle to the vehicle longitudinal direction (6) or to the desired vehicle longitudinal direction (6a).

8. Vehicle charging system (8) according to claim 7, characterized in that - that the first inductive charging device (1 ) is a mobile inductive charging device (1a) which is arranged on and / or in a vehicle (2), and the further inductive charging device (1 ) is a stationary inductive charging device (1 b) or - that the first inductive charging device (1 ) is a stationary inductive charging device (1 b) and the further inductive charging device (1 ) is a mobile inductive charging device (1 a) which is arranged on and / or in a vehicle (2).

9. Vehicle charging system (8) according to claim 7 or claim 8, characterized in that - the positioning signal winding (41) at least approximately crosses at least one of the winding axes of the energy transmission winding (4) of the first inductive charging device and - the first radial longitudinal direction (11 a) and the second radial longitudinal direction (11 b) intersect at least approximately in the center (7) of the energy transmission winding (4) of the further inductive charging device.

10. Vehicle charging system (8) according to claim 7 or claim 8, characterized in that 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).

11. Vehicle charging system (8) according to claim 10, characterized in that the positioning signal winding (41) is arranged further away from the further inductive charging device (1) during a positioning process than the center of the energy transmission winding (4) of the first inductive charging device (1).

12. Vehicle charging system (8) according to claim 10, characterized in that the positioning signal winding (41) is arranged less far away from the further inductive charging device (1) during a positioning process than the center of the energy transmission winding (4) of the first inductive charging device (1).

13. Vehicle charging system (8) according to one of claims 7-12, characterized in that - the positioning signal winding (41) is formed by conductor tracks (38) which are applied to at least one printed circuit board (37) and - the first sensor winding (9a) and the second sensor winding (9b) are formed by conductor tracks (38) which are applied to at least one printed circuit board (37).

14. Inductive charging device (1) for a vehicle charging system (8) according to one of claims 7-13 with an energy transmission winding (4) and at least two flux guiding elements (5) and at least one positioning signal winding (41), wherein - the positioning signal winding (41) is designed as a solenoid (42) with a winding axis (28) in the vehicle longitudinal direction or desired vehicle longitudinal direction and - the flux guiding elements (5) are suitable for guiding a magnetic field during an energy transfer process to or from the inductive charging device (1) and - the positioning signal winding (41) is arranged in a gap (27) between at least two of the at least two flux guiding elements (5) or in a gap (26) between at least one flux guiding element (5) and a housing (17).

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