Charging device for inductive charging of a mobile terminal device and motor vehicle with such a charging device and operating method for the charging device

Abstract

Charging device (11) for inductive charging of a mobile terminal (21), wherein the charging device (11) comprises: a support plate (12) for placing the terminal (21) in a support volume, and an electrical transmitting coil (19) for generating an alternating magnetic field (42) for induction charging and a magnet arrangement (20) for magnetically fixing the terminal device (21) with respect to the transmitting coil (19) by means of a permanent magnetic field of the magnet arrangement (20) while the terminal device (21) is placed on the support plate (12), wherein the transmitting coil (19) and the magnet arrangement (20) are arranged together in a holding device (13) which is arranged in a recess (15) of the support plate (12) and which is mounted in the recess (15) along a coil axis (25) of the transmitting coil (19) by means of a bearing device (30) so as to be movable wholly or partially out of the recess (15) towards the support volume, wherein the holding device (13) is fixed against a translational movement parallel to a plane in which the support plate (12) extends and / or the bearing device (30) has a retaining device (13) which limits a withdrawal path of the holding device (13) out of the recess (15) to a path length of less than 3 centimeters, wherein the retaining device (13) provides a ring or several tabs on the holding device (13), by means of which a diameter of the holding device (13) in the region of the retaining device (13) is larger than the recess (15).

Description

The invention relates to a charging device for induction charging of a mobile terminal, for example a smartphone or a tablet PC. The charging device can be part of a docking station, for example, as it can be provided in a center console of a motor vehicle. In order to be able to store the mobile terminal, the charging device has a bearing plate from which, starting from an electrical transmitting coil (charging coil), an alternating magnetic field for the induction charging can be generated. In order to adjust the transmitting coil in position with respect to the terminal, a magnet arrangement is provided, as can be provided, for example, according to the Qi2 TM standard. The invention also includes a motor vehicle having the charging device and an operating method according to which the charging device can be operated.In order to be able to recharge or supply a portable mobile terminal, such as a smartphone or a tablet PC, wirelessly with electrical energy, an electrical transmitting coil or charging coil for induction charging can be integrated into a charging device. This saves the terminal from being plugged onto a charging plug. A charging device for induction charging can additionally have a magnetic arrangement, for example a circular ring arrangement of magnets or at least one circular arc arrangement (pitch circle) of such magnets, in order to be able to fix or specify a position or position of the terminal device with respect to the transmitting coil. Known standards for this are MagSafe ( .RTM. ) and Qi2 ( .RTM. ).In the mobile terminal, the electrical receiving coil for the induction charging is generally located on the rear side, that is to say on the wall of the terminal facing away from the main screen. Together with the receiving coil, a corresponding magnet arrangement can also be integrated in this wall in order to be able to ensure the described magnetic fixing of the receiving coil with respect to the transmitting coil.One problem of today's mobile terminals is that their rear side, i.e. the rear wall with the receiving coil integrated therein, is often not planar or planar, but rather, for example, due to a size of a camera, there is no planar support surface. If the rear side of the terminal is thus placed on a support plate of a loading device, it will not lie flat on the support plate there, but will assume a tilted position, for example, by the camera. Accordingly, an air gap is produced between the rear wall of the terminal and the supporting plate. The alternating magnetic field must be transmitted across this air gap from the transmitting coil of the charging device to the receiving coil, which leads to a reduction in the energy efficiency. In addition, the magnetic holding force is too low due to the air gap to hold the telephone in the desired position.Loading devices with planar loading plates are known, for example, from DE 11 2020 003 590 T5 and US 2020 / 0083726 A1. In these loading devices, the problem of a protruding camera is solved in that the bearing plate is smaller than the rear wall of the terminal device, so that the camera can protrude beyond the bearing plate. However, this reduces the hold of the terminal in the charging device.KR 10 2012 0 117 262 A discloses a wireless energy transmitter for vehicles for tuning a position of a first coil within a housing to the position of a second coil using a mechanical device. To this end, a position fixing device selectively fixes or releases a position of a transfer coil unit that is disposed in the housing and includes the first coil and a magnet according to the user control. The charge energy is supplied to a charge target device, for example, a mobile terminal, by inductive coupling of the first coil and the second coil. Another magnet is attached to the charge target device.EP 2 946 050 B1 discloses a device for wirelessly transmitting electrical power and electrical signals, comprising a first electrical component mounted on a mechanical structure, in particular in a housing or a trim part, wherein the first electrical component is held movably and actuating means are provided for the relative movement of the first electrical component, wherein the actuating means are configured to improve the electromagnetic coupling between the first and the second electrical component by a movement of the first electrical component depending on the position of a second electrical component with respect to the mechanical structure, wherein at least one of the electrical components is rotatably mounted in a mounting box, wherein a trough rotatably mounted in the mounting box is provided for receiving the electrical components, and actuating means are provided for positioning the trough in the mounting box.US 2015 / 0270046 A1 discloses an electronic device comprising: a housing defining a connection surface; and a magnetic member disposed adjacent to the connection surface and within the housing, wherein the magnetic member is configured to align the housing with an adjacent outer surface by moving one of the housing and the outer surface relative to each other to achieve an aligned position; and the magnetic member is further configured to resist separation of the housing from the outer surface when the housing and the outer surface are in the aligned position.WO 2014 / 157840 A1 discloses a wireless power transmission device and a vehicle equipped therewith, wherein the wireless power transmission device comprises: a transmitting unit for transmitting a wireless power signal to a wireless power receiving device; and an upward driving unit for driving the transmitting unit upward. In particular, energy transmission to terminals of different sizes is provided structurally.DE 10 2018 201 300 A1 discloses a charging device for wirelessly charging an electrical energy store of a mobile terminal, wherein the charging device comprises a housing with charging electronics, with a support region for the mobile terminal and with an air inlet opening and with an air outlet opening, wherein the charging device has an air conveying device for aspirating air through the air inlet opening, for passing through an air conveying path through the air conveying unit and for blowing out the air through an air outlet opening.The invention is based on the object of enabling an efficient inductive charging process even in a charging device with a bearing plate on which the entire terminal device is intended to be able to rest.The object is achieved by the subject matters of the independent claims. Advantageous further developments of the invention are described by the dependent patent claims, the following description and the figures.As a solution, the invention provides a charging device for induction charging of a mobile terminal. A mobile terminal is understood here in a manner known per se to be a portable computer device, in particular a smartphone or a tablet PC.In a manner known per se, the loading device has a support surface or support plate for placing the terminal device on top. The bearing plate can be part of a larger structure, for example a depression or a trim part in the interior of a motor vehicle. The support plate is preferably of such a size or dimensioned in such a way that a terminal can be placed or can be placed in its full length and / or width. Exemplary dimensions are edge lengths in a range of more than 15 cm, for example in a range of 15 cm to 25 cm. In the mounted state, the terminal is then located on the support plate. This space above the support plate is referred to herein as the "support volume".The charging device also includes, in a manner known per se, an electrical transmitting coil or charging coil which is configured to generate an alternating magnetic field for the induction charging. Of course, the corresponding power electronics for operating the electric transmitting coil for generating the alternating magnetic field can also be provided in the charging device. However, to understand the invention, it is sufficient to know the electrical transmitting coil.Finally, a magnet arrangement is also provided in the charging device, for example a circular ring or a circular arc of magnets. This magnet arrangement is configured to fix the terminal magnetically with respect to the transmitting coil by means of a permanent magnetic field of the magnet arrangement or at least a time-invariant magnetic field during the induction charging. The magnet arrangement can be formed, for example, from permanent magnets, as is known per se for the standards already mentioned. The terminal device can be fixed while the terminal device is located on the support plate or is placed there when the terminal device is located in the support volume.In order to now avoid in this arrangement that an air gap remains between the transmitting coil and the placed terminal, for example, by a protruding camera of the terminal, it is provided according to the invention that the transmitting coil and the magnet arrangement are arranged together in a holding device. This holding arrangement constitutes a "loading head" movably mounted in the supporting plate. The holding device can be designed, for example, as a housing, as can be produced, for example, from a plastic by means of an injection molding process. The holding device is movably arranged in the bearing plate by providing in the bearing plate a recess in which the holding device is arranged. The holding device is thus not covered by the bearing plate, but can directly contact an placed terminal through the cutout. The holding device can be designed, for example, as a connecting piece or cylinder or a pouch (in particular a flat cylinder, having a diameter which is at least three times greater than the cylinder height). A correspondingly round cutout can then be provided in the bearing plate, in which the holding device is then arranged.In order to close an air gap between the terminal device placed on top and the charging device, the holding device is arranged movably in the recess of the bearing plate by means of a bearing or bearing device, namely the holding device can be moved completely or partially out of the recess toward the support volume at least along a coil axis of the transmitting coil. In other words, the spool can slide out of the recess or be moved out along its spool axis. The coil axis is a virtual line representing a surface normal of the winding plane of the windings of the coil. The transmitting coil is arranged in particular coplanar or plane-parallel to a plane described by the surface of the supporting plate. The holding device can be driven by the bearing device, for example, by a motor, for example, and / or the bearing device can also bear or hold the holding device in a correspondingly loose or clearance manner, so that the holding device can be pulled out of the recess, for example, by the described permanent magnetic field of the magnet arrangement and a magnetic force resulting therefrom. If a terminal is thus placed on the support plate, the holding device can now be moved by its bearing device out of the recess at least along the coil axis toward the mobile terminal and thus come to rest against or lie against the terminal without any gaps (i.e. without an air gap between them), in particular directly lie against it, while the terminal is placed or placed on the support plate.The invention provides the advantage that even if a terminal cannot be placed completely or without gaps on a support plate of the charging device in the region of its receiving coil, because, for example, a protruding or protruding camera of the terminal prevents a planar placement or without gaps, the transmitting coil can nevertheless be moved out of the recess of the support plate to the terminal by its movably mounted holding device, whereby an air gap can be avoided and the alternating magnetic field of the transmitting coil can thus efficiently penetrate or pass over the terminal and its receiving coil.According to the invention, the holding device is fixed with respect to the bearing plate against a translatory movement parallel to the plane in which the bearing plate extends. In other words, the holding device cannot be moved laterally in translation in the bearing plate, but can only be pulled out of the holding plate and preferably still be tilted in the process. For this translatory fixing, for example, a shape of the recess in the bearing plate can correspond to the shape or the contour of the holding device to the effect that a play in the translatory movement direction is less than three millimeters, in particular less than two millimeters. This still allows the tilting movement, but a translatory movement by more than this play is then blocked. The fixation with respect to the translatory movement has the advantage that the terminal cannot "move around" on the support plate in the mounted state, i.e. does not slip there, as might otherwise be caused by vibrations in a motor vehicle, for example, during travel over uneven driving surfaces.Additionally or alternatively, it is provided according to the invention that, when the terminal is removed from the support plate, it is prevented that the holding device with the transmitting coil and the magnet arrangement remains adhered to the terminal. For this purpose, the bearing device, by which the holding device is mounted or held with respect to the bearing plate, has a retaining device which limits a pull-out path of the holding device out of the cutout to a path length of less than three centimeters. For example, the pull-out path may be limited to a value in the range of five millimeters to 15 millimeters. If a user picks up the terminal from the support plate, then the holding device is retained by the retaining device when the pull-out path is reached and the user thus pulls the terminal off the holding device. The magnet arrangement can have a permanent magnet force which permits this, for example, at a force of less than ten Newtons, in particular less than six Newtons.In order to provide such a retaining device, it is provided that the retaining device provides a ring or a plurality of lugs, by means of which a diameter of the retaining device in the region of the retaining device is greater than the cutout. In other words, the ring or the plurality of lugs on the holding device therefore do not fit through the cutout. Thus, the holding device with the ring or the tabs abuts an edge of the recess, which then means that the pull-out path is reached.The invention also encompasses further developments, which result in additional advantages.If the camera or another extension is located in an edge region of the rear wall of the terminal, the terminal is tilted on the supporting plate during placement, whereby the rear wall of the terminal is oriented obliquely to the supporting plate. In order to also compensate for this angle of inclination of the rear wall of the terminal, a further development provides that the holding device is mounted in a tiltable manner with respect to the supporting plate by the bearing device. For example, the bearing device can provide a corresponding clearance or free space for tilting the holding device in the recess. Additionally or alternatively, for example, a part of the bearing device can be designed as a ball segment. The holding device is thus mounted in the recess so as to be movable not only transversely out of the recess along the coil axis, but preferably also tiltable or tiltable. A maximum angle of inclination of the coil axis which results from this with respect to a surface normal of the plane in which the bearing plate extends is preferably in a range from 0 degrees to 40 degrees in terms of absolute value. Thus, the holding device can bear directly over the entire surface with that adhesion surface or that adhesion region with which the holding device is intended to adhere to the terminal by the permanent magnetic field, even if the terminal rests on the bearing plate in a tilted or inclined manner.After removal or removal of the terminal, the holding device preferably automatically retracts into the recess of the bearing plate. For this purpose, according to a further development, it is provided that, in the case of an empty support volume (i.e. when no terminal device rests on the support surface), the holding device is held by its bearing device on a gravity-based and / or spring-based basis in a retracted position, in which the holding device is retracted in the recess. If the bearing surface is oriented horizontally, for example, the holding device can fall back into the recess by a correspondingly loose or loose arrangement (the bearing device is designed to be correspondingly loose). In order to ensure this even in the case of vibrations, for example, that is to say to secure the retracted position even in the case of vibrations, a retaining spring can be provided in order to hold the holding device in the retracted position. This is advantageous in particular when using the charging device in a motor vehicle, where shaking movements might otherwise cause the holding device to vibrate or rattle in the cutout during a journey.In order to move the holding device out of the recess into the support volume, i.e. toward the terminal, when placing a terminal, a particularly robust and efficient mechanism is provided, since according to a further development a magnetic field strength of the magnet arrangement is large enough in relation to an own weight of the holding device and in relation to a retaining force of the storage device or is large enough to pull or move the holding device out of its retracted position or out of the holding device into a pulled-out position, in which the holding device protrudes completely or partially out of the recess and holds it there in the described manner. This naturally presupposes that the magnet arrangement has a corresponding magnet arrangement or a magnetic arrangement (for example a soft iron sheet) in its permanent magnetic field, that is to say that the holding device adheres to a magnetic terminal. Thus, the holding device can itself pull towards the terminal by the permanent magnetic field of its magnet arrangement. In order to make this possible, the holding device is balanced in the described manner, for example by a selection of the material (preferably a plastic) and / or a material thickness of the holding device and / or with respect to the retaining force of the bearing device, that is to say, for example, the retaining force of the described spring arrangement or retaining spring, in such a way that the magnetic field strength of the magnet arrangement is sufficient for this.During a charging process, an electrical energy store of the mobile terminal should be held in a temperature window, which is also referred to as the "well-being range" of the energy store. This is particularly important in energy stores based on lithium-ion batteries. In order to achieve this, a further development provides that a fan is provided in the charging device, which fan is configured to convey an air flow through the cutout, that is to say along an outer wall of the holding device and / or through the holding device. For example, the air flow can suck in air between the terminal device placed on top and the supporting plate and suck in this sucked-in air through the cutout past the holding device and / or through the latter into the interior of the loading device. Blowing towards the terminal can also be provided. In order for the air flow to be conveyed through the holding device, it can have, for example, corresponding through-openings or channels. By conveying an air flow in the region of the recess and the holding device, the advantage results that a heat source, namely the transmitting coil and the alternating region between transmitting coil and terminal, are actively cooled.In order to allow cooling and an air exchange between the terminal (in the mounted state) and the support plate, a further development provides that the support plate has support webs or support ribs for the terminal. In other words, the rear wall of the terminal does not touch the bearing plate over its full surface, but rather lies on an effective bearing surface which is provided by the webs. In particular, the bearing surface is thereby reduced to a value of less than 20 percent, in particular less than ten percent, of the total surface area of the bearing surface covered or covered by a terminal device. Air can thus flow between the terminal and the bearing plate, namely between the bearing webs or bearing ribs. This may be advantageous for convection cooling. In connection with the described fan, the air flow conveyed by the latter can be conveyed in this way between the terminal and the supporting webs / supporting ribs. Due to the reduced contact surface or the contact surface reduced to the contact surface of the support webs / support ribs, a transfer of heat between the support plate and the terminal is also reduced.The part of the holding device which projects through the recess is preferably designed in the manner described as a cylindrical base or as a cylindrical head piece, that is to say in particular as a flat cylinder, the diameter of which is at least four times as large as the height or length of the base or head piece along the coil axis. The part of the base or head piece facing the terminal or the bearing region has a planar base surface which represents an adhesion region for magnetically adhering to the terminal. At a lower region of the base or head piece or region facing away from the base surface, the ring or the tabs of the retaining device can then be provided in the described manner, so that the base or the head piece cannot be pulled out of the cutout.As already stated, a further solution of the invention provides the described motor vehicle in which at least one charging device of the described type is provided. In a motor vehicle, this charging device is particularly advantageous because a terminal can be placed on the support plate, for example in a region of a central console, and can be recharged there by means of induction charging.The respective bearing plate of each loading device is preferably oriented in a horizontal plane in the motor vehicle or in a plane whose normal vector has an angle of less than 20 degrees with respect to the vertical. In other words, the terminal device is therefore oriented flat or horizontal or at least inclined by less than the described inclination in the motor vehicle on the bearing plate. Thus, it can also be ensured, for example, during a travel through a striking hole that the terminal remains adhered to the holding device, which does not have to be ensured in a more strongly or further tilted position due to the jerk forces occurring.When the charging device is operated, the method also belonging to the invention results, in which a mobile terminal is used, which has, in its rear wall, which faces the supporting plate of the charging device, the receiving coil for the induction charging and a magnetic fixing device (for example a ring of permanent magnets and / or a soft magnetic sheet metal). When placed on the support plate, this mobile terminal enters into a magnetic interaction with the holding device of the charging device by means of its fixing device, which also has a magnet arrangement with a permanent magnetic field. As a result of a magnetic force of the interaction which arises in this case, the holding device is completely or partially pulled out of the cutout of the bearing plate and, in addition, the terminal is pulled into a predefined position relative to the transmitting coil of the holding device. In other words, the receiving coil and the transmitting coil are "found" by the magnetic interaction between the terminal and the holding device. The terminal can then also be placed on the support plate in such a fixed manner, wherein it is level or can be compensated if the wall cannot be placed fully on the support plate, because, for example, a camera of the terminal projects or protrudes from the wall. The holding device can be tilted accordingly, for example, in order to nevertheless bear without gaps against the wall of the terminal with the adhesion region or the adhesion surface.The invention also comprises developments of the method as they result from the corresponding developments of the charging device according to the invention. For this reason, the corresponding features of the developments of the method are not described again here.For use cases or application situations which can arise in the method and which are not explicitly described here, provision can be made for an error message and / or a request for inputting a user feedback to be output and / or for a default setting and / or a predetermined initial state to be set according to the method.The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.The invention also includes the combinations of the features of the described embodiments. The invention therefore also comprises implementations which each have a combination of the features of a plurality of the described embodiments, provided that the embodiments have not been described as mutually exclusive.Exemplary embodiments of the invention are described below. The following shows: FIG. 1 shows a schematic illustration of an embodiment of the motor vehicle according to the invention with a loading device, the holding device of which is shown once in a retracted position and once in a pulled-out position; FIG. 2 shows the loading device from FIG. 1 in a side view with the holding device once in the retracted position and once in the extended position; FIG. 3 shows a schematic illustration of a process of placing a mobile terminal on the charging device, resulting in an embodiment of the method described; FIG. 4 shows a schematic illustration of a longitudinal section of the loading device with a cooling device having a fan.The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that also develop the invention independently of one another. Therefore, the disclosure is intended to include combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.In the figures, identical reference numerals designate functionally identical elements.FIG. 1 shows a motor vehicle 10, which can be a motor vehicle, in particular a passenger car or truck. In the motor vehicle 10, a charging device 11 can be provided, which is illustrated in two different states in the figure.The charging device 11 can be provided, for example, in a central console or in a rear bench or in an interior trim of a vehicle door, to name only exemplary installation sites. The loading device 11 can have a support surface for a mobile terminal, which can be formed by a support plate 12. The bearing plate 12 can have bearing webs 14.For inductive charging, a holding device 13 can be provided, which can be arranged in a recessed manner in a recess 15 of the bearing plate 12. The recess 15 can be recessed in the bearing plate 12 for example as a bore or in an injection molding process.The holding device 13 can be designed, for example, as a flat cylinder in the described manner, that is to say with a connecting piece or as a loading head. In a retracted position 17, the holding device 13 can be recessed in the recess 15 in such a way that the holding device 13 ends flush or planar with the bearing plate 12. This prevents an object from being able to tick on a protruding edge of the holding device 13 and also prevents dirt from accumulating on an edge. In a pulled-out position 18, on the other hand, the holding device 13 can be extended out of the recess. This pull-out position 18 takes up the holding device in particular when a terminal with a magnetic rear wall rests on the supporting plate 12.A transmitting coil 19 for induction charging and a magnet arrangement 20, for example a ring of permanent magnets, can be embedded or integrated into the holding device 13. Power electronics for the operation of the transmitting coil 19 can be provided in a manner known per se. It is not relevant here any further for the explanation of the invention.FIG. 2 shows a side view of how, when the terminal 21 is placed on, a rear wall 22 of the terminal 21 facing the bearing plate 12 can be aligned obliquely with respect to the bearing plate 12, because, for example, a camera 23 of the terminal 21 protrudes from the wall 22. If the holding device 13 assumes the pull-out position 18, it is nevertheless possible to prevent an air gap 24 from remaining between the holding device 13 and the wall 22 of the terminal 21. For changing into the pull-out position 18, the holding device 13 can be extended or pulled out along a coil axis 25 of the transmitting coil 19 and can additionally be inclined or tilted by a tilt angle 26 with respect to the vertical 27.FIG. 3 illustrates the adjustment or extraction process 28 by which the holding device 13 is extracted from the recess 15 out of the supporting plate 12. If the terminal 21 approaches the bearing plate 12, a magnetic interaction 29 can occur in the holding device 13 due to a magnetic fixing device in the terminal 21, for example further permanent magnets, and the magnet arrangement 20 in the holding device 13, as a result of which a magnetic force acts on the holding device 13. A bearing device 30 for the holding device 13 holds the latter in a translatory and preferably also tiltable manner along the spool axis 25 with respect to the bearing plate 12, so that in the extended position 18 the holding device 13 is extended or extended from the recess 15 of the bearing plate 12 to such an extent that it bears completely directly against the wall 22 of the terminal 21 by a contact surface 31. Thus, an alternating magnetic field 42 generated by the transmitting coil 19 can penetrate the receiving coil of the terminal device 21 efficiently or with a particularly low loss.As shown in FIG. 4, during the charging process carried out after the placement, a fan 60 of a cooling device 61 is preferably operated, by means of which a stream of air 62 is drawn through the cutout 15 and thus past the holding device 13 and / or through it into the charging device 11 or is ejected therefrom, so that the cooling stream of air 62 is conveyed between the mobile terminal 21 and the supporting plate 12.The implementation in the vehicle is as follows, according to a preferred implementation form.A storage surface is provided in the vehicle, which contains the electronics, the cooling system and the transmitting coils. The surface of the support surface or depositing surface is preferably designed to be anti-slip. It preferably keeps a distance between telephone and surface in order to cool it by means of fans, for example by means of bearing webs or bearing ribs.In addition, most telephones have a camera which can be located at almost any location. This results in the problem that the coil with the magnet can have different distances from the telephone. To ensure the charging function and positioning of the telephone, the transmitting coil must abut completely on the coil of the telephone.For this purpose, the transmitting coil with a revolving magnet can move upward along the coil axis. Preferably, it can additionally be inclined or tilted laterally.Overall, the examples show how a wireless charger (charging device for induction charging) can be provided for one of the MagSafe and Qi2 (MPP qi standard) standards in a motor vehicle.

Claims

Charging device (11) for induction charging of a mobile terminal (21), wherein the charging device (11) comprises: a support plate (12) for placing the terminal (21) in a support volume, and an electrical transmitting coil (19) for generating an alternating magnetic field (42) for induction charging, and a magnet arrangement (20) for magnetically fixing the terminal (21) with respect to the transmitting coil (19) by means of a permanent magnetic field of the magnet arrangement (20), while the terminal (21) is placed on the support plate (12), wherein the transmitting coil (19) and the magnet arrangement (20) are arranged together in a holding device (13), which is arranged in a recess (15) of the support plate (12) and which is mounted by means of a bearing device (30) in the recess (15) so as to be movable completely or partially out of the recess (15) towards the support volume along a coil axis (25) of the transmitting coil (19), wherein the holding device (13) is fixed against a translatory movement parallel to a plane in which the bearing plate (12) extends and / or the bearing device (30) has a retaining device (13) which limits a pull-out path of the holding device (13) out of the recess (15) to a path length of less than 3 centimeters, wherein the retaining device (13) provides a ring or a plurality of lugs on the holding device (13), by means of which a diameter of the holding device (13) in the region of the retaining device (13) is greater than the recess (15).Loading device (11) according to claim 1, wherein the holding device (13) is mounted by the bearing device (30) such that it can be tilted with respect to the bearing plate (12).Loading device (11) according to one of the preceding claims, wherein, in the case of an empty support volume, the holding device (13) is held by the bearing device (30) in a gravity-based and / or spring-based manner in a retracted position (17), in which the holding device (13) is retracted in the cutout (15).Charging device (11) according to one of the preceding claims, wherein a magnetic field strength of the magnet arrangement (20) in relation to an own weight of the holding device (13) and in relation to a retaining force of the storage device (30) is large enough to hold the holding device (13) in a pull-out position (18) in which it protrudes from the recess (15) if the magnet arrangement (20) adheres to a magnetic terminal (21).Charging device (11) according to one of the preceding claims, wherein a fan (60) is provided in the charging device (11), which fan is configured to convey an air stream (62) through the cutout (15) along an outer wall of the holding device (13) and / or through the holding device (13).Loading device (11) according to one of the preceding claims, wherein the bearing plate (12) has bearing webs (14) for the terminal device (21).Loading device (11) according to one of the preceding claims, wherein the holding device is designed as a cylindrical base or as a cylindrical head piece with a planar base surface as an adhesion region for magnetically adhering to the terminal (21).Motor vehicle (10) having at least one charging device (11) according to one of the preceding claims.Motor vehicle (10) according to claim 8, wherein a respective bearing plate (12) is arranged in a horizontal plane or in a plane whose normal vector has an angle of less than 20 degrees with respect to the vertical (27).Method for operating a charging device (11) according to one of Claims 1 to 7, wherein a mobile terminal (21) which, in a wall (22) which faces a supporting plate (12) of the charging device (11), has a receiving coil for induction charging and a magnetic fixing device, enters a magnetic interaction (29) with a holding device (13) of the charging device (11) by means of the fixing device when it is placed on the supporting plate (12), and, by means of a magnetic force of the interaction (29), pulls the holding device (13) completely or partially out of a cutout (15) and pulls the terminal (21) into a predefined relative position with respect to a transmitting coil (19) of the holding device (13).

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