Stationary charging device having a magnetic locking device

Abstract

The invention relates to a stationary charging device (10) which comprises a charging socket (20), into which a vehicle-side charging plug can be plugged, a movable charging socket cover (30), which closes the charging socket (20) in a closed position and releases the charging socket in an open position, and a locking device (40), by means of which the charging socket cover (30) can be locked in the closed position. The locking device (40) comprises a ferromagnetic locking element (42), a permanent magnet (44), the permanent magnet (44) being arranged in such a way that the ferromagnetic locking element (42) is held in the closed position of the charging socket cover (30) by the magnetic attraction force of the magnetic field of the permanent magnet (30), an electromagnetic unlocking device (46) having an electromagnet (47), and a control device (50), which is designed to actuate the electromagnet (47) in such a way that a magnetic field directed oppositely to the magnetic field of the permanent magnet (44) can be generated in order to remove the magnetic attraction force acting on the ferromagnetic locking element (42) and thereby unlock the charging socket cover (30). The locking device (40) operates purely magnetically and additionally does not have any moving parts which could be subject to wear or the mobility of which could be impaired by soiling.

Description

[0001] DESCRIPTION

[0002] Stationary charging device with a magnetic locking device

[0003] The present invention relates to a stationary charging device for electrically charging a traction battery of a battery-electric vehicle, for example a so-called hybrid vehicle or a purely electric vehicle. In particular, the invention relates to a locking device for a charging socket cover of a stationary charging device.

[0004] A charging port cover of a stationary charging device is typically locked by means of a mechanical locking mechanism. For example, bolt locks are used, in which an electrically actuated bolt engages a locking element attached to the charging port cover when it is in the closed position, thus locking it.

[0005] Such a locking mechanism is known, for example, from US 2011 / 0316479 Al.

[0006] Such a bolt locking mechanism is relatively prone to malfunction. Firstly, it is susceptible to contamination, which, with increasing levels of contamination, can restrict the bolt's movement. Secondly, the bolt locking mechanism is subject to significant wear, which can lead to damage to the bolt or the locking element and thus to failure of the locking mechanism. Furthermore, the bolt locking mechanism can be damaged as a result of overloading, for example, due to vandalism. The present invention therefore aims to create a stationary charging device whose locking mechanism operates with relatively low wear and is robust against contamination.

[0007] This problem is solved according to the invention by a stationary charging device with the features of claim 1.

[0008] The stationary charging device according to the invention for electrically charging a traction battery of a battery-electric vehicle comprises a charging socket into which a vehicle-side charging plug can be inserted. The charging socket is preferably a female connector into which a male connector can be inserted, thereby establishing an electrical connection between the charging device and the traction battery of the battery-electric vehicle, whereby either an alternating voltage or a direct voltage is transmitted from the charging device to the vehicle-side traction battery.

[0009] The stationary charging device further comprises a movable charging socket cover that closes the charging socket in a closed position and releases it in an open position. The charging socket cover can be designed, for example, as a flap, a slider, or as a pivoting unit integrally formed with the charging socket, the closed charging socket cover protecting the charging socket from contamination and unauthorized access.

[0010] The stationary charging device also features a locking mechanism that secures the charging port cover in the closed position. Opening the charging port cover requires prior unlocking, which typically occurs only after successful user authentication. Once the locking mechanism unlocks the charging port cover, it can be opened, allowing the user access to the charging port, insert the charging plug, and begin the charging process.

[0011] The locking device comprises a ferromagnetic locking element made of a ferromagnetic material, for example ferritic steel, so that it is magnetically attractive.

[0012] Furthermore, the locking device comprises a permanent magnet arranged such that the ferromagnetic locking element is held in the closed position of the charging port cover by the magnetic attraction of the permanent magnet's magnetic field. The ferromagnetic locking element is positioned relative to the permanent magnet such that it is operatively connected to the permanent magnet's magnetic field. Preferably, the ferromagnetic locking element is located adjacent to the permanent magnet. When the charging port cover is closed, the permanent magnet magnetically attracts the ferromagnetic locking element, thus locking the charging port cover purely magnetically. The charging port cover is therefore held exclusively by the magnetic attraction of the permanent magnet.The permanent magnet is dimensioned such that its magnetic force is strong enough to prevent the charging port cover from being opened manually. The locking device also includes an electromagnetic release mechanism with an electromagnet and a control unit. The control unit is configured to drive the electromagnet in such a way that a magnetic field opposite to that of the permanent magnet can be generated. The field lines of the electromagnet's magnetic field run essentially parallel to and in the opposite direction to those of the permanent magnet's magnetic field, thereby canceling the magnetic attraction acting on the ferromagnetic locking element. This unlocks the charging port cover, allowing it to be opened by a user.To unlock the charging port cover, the electromagnet only needs to be briefly energized until the user moves it into the open position. Advantageously, a position detection system is provided to recognize the position of the charging port cover.

[0013] The locking device operates purely magnetically and has no moving parts that could be subject to wear or whose movement could be impaired by contamination. Furthermore, the locking device operates almost without current when locked, resulting in relatively low energy consumption.

[0014] In a particularly preferred embodiment of the invention, the ferromagnetic locking element is arranged on the charging port cover, whereas the permanent magnet is arranged on a housing of the charging device. This embodiment is relatively simple in design and therefore cost-effective to implement. Furthermore, the electromagnet, which is sensibly located in the housing due to its leads to the control unit, can be positioned relatively close to the permanent magnet. Alternatively, the electromagnet can also be arranged on the charging port cover.

[0015] In a particularly preferred embodiment of the invention, the stationary charging device is designed as a curbside charging device. A curbside charging device is understood to be a charging device that is embedded or recessed into the ground, in particular into a curb or kerbstone, a sidewalk, or a parking area. Specifically, the power electronics of the charging device are embedded or recessed in the ground, particularly into a curb or kerbstone, a sidewalk, or a parking area. The curbside charging device makes it possible to arrange a charging device for charging the traction battery of a battery-electric vehicle in urban areas in a space-saving manner, without aesthetically impairing the cityscape.

[0016] In a further particularly preferred embodiment of the invention, the ferromagnetic locking element comprises a sheet metal element. The sheet metal element is made of a ferromagnetic material, for example, ferritic steel, so that it is attracted to the magnetic field of the permanent magnet. The sheet metal element is relatively easy and inexpensive to manufacture.

[0017] The sheet metal element is preferably made of electrical steel. So-called electrical steel sheets are typically used to manufacture stator cores for electric motors because their alloy composition of iron and silicon gives them particularly good magnetic properties. Preferably, the electromagnet is arranged adjacent to the permanent magnet, which allows the magnetic fields to overlap particularly well, resulting in a complete cancellation of the permanent magnet's magnetic attraction.

[0018] In a further particularly advantageous embodiment of the invention, the permanent magnet is dimensioned such that the magnetic attraction force acting on the ferromagnetic locking element is between 5 N and 150 N. A magnetic attraction force exceeding 50 N is particularly preferred, as this prevents the lid from being opened by hand without authorization.

[0019] In a further particularly preferred embodiment of the invention, the electromagnet comprises a coil. Furthermore, the control device is configured to control the electromagnet such that, with the charging port cover closed, a magnetic field oriented in the same direction as the magnetic field of the permanent magnet can be generated by adjusting the locking current direction in the coil. The magnetic fields, whose field lines are directed in the same direction, superimpose in such a way that a combined magnetic field is formed whose magnetic attraction is greater than that of the permanent magnet field alone. The electromagnetic magnetic field thus also acts on the ferromagnetic locking element, so that the holding force acting on the charging port cover can be further increased if necessary.

[0020] In a further advantageous embodiment of the invention, the control device is configured to energize the coil of the electromagnet in the locking current direction such that the resulting heat warms the charging port cover, the housing cover, and / or components arranged on the housing cover. The coil can thus be used, for example, to prevent the charging port cover from icing up in winter, eliminating the need for additional separate heating elements. The coil is energized in the manner already described, so that the electromagnetic magnetic field also exerts an attractive force on the ferromagnetic locking element, and the charging port cover remains locked during heating.

[0021] In a further particularly preferred embodiment of the invention, a compression spring is provided that biases the charging port cover in the opening direction. The compression spring is preferably arranged on the inside of the charging port cover, in or adjacent to the charging port. In the closed state, the compression spring is thus compressed, resulting in a constant spring force acting on the charging port cover, which the permanent magnet must additionally counteract. Accordingly, the permanent magnet must be sufficiently strong to counteract the spring force and any additional manual force required by an attempted unauthorized access. After unlocking by means of the electromagnet, the compression spring lifts the charging port cover by a defined amount to signal to the user that the charging port cover can be opened manually.In this process, the charging port cover is only lifted to the extent necessary, due to the spring's dimensions, to keep the ferromagnetic locking element within the effective range of the permanent magnet's magnetic field. This ensures that if the charging port cover is not opened, the permanent magnet is able to return it to the locked position. An embodiment of the present invention is described below with reference to the accompanying figures. These figures show:

[0022] Figure 1 shows a schematic representation of a stationary charging device according to the invention in a cutaway front view,

[0023] Figure 2a shows a schematic representation of the charging socket cover of the stationary charging device of Figure 1 in the closed position in a detailed view.

[0024] Figure 2b shows a schematic representation of the charging socket cover of the stationary charging device of Figure 1 in the unlocked position in a detailed view, and

[0025] Figure 2c shows a schematic representation of a charging socket cover of the stationary charging device of Figure 1 in an open position in a detailed view. Figure 1 shows a stationary charging device 10 according to the invention for charging a traction battery of a battery-electric vehicle, which is designed as a curbside charging device 15. The charging device 10 comprises a charging socket 20 for receiving a Type 2 charging plug for transmitting an alternating voltage between the charging device 10 and a traction battery of a battery-electric vehicle. The curbside charging device 15 comprises a housing 12, which is essentially formed by a curbside base body 14 and a housing cover 13 that closes the curbside base body 14 at the top. The charging socket 20 is attached to the housing cover 13 such that the plug opening 22 faces upwards, as shown in Figures 2a, 2b, and 2c.Figures 2a, 2b, and 2c further show a movable charging port cover 30, which is attached to the housing cover 13. The charging port cover 30 is designed as a charging port flap 34, which is pivotally mounted about a pivot axis and is movable between a closed position (see Figure 2a) and an open position (see Figure 2c). In the closed position, the charging port cover 30 seals the charging port 20, whereas in the open position, the charging port cover 30 releases the charging port 20.

[0026] The charging device 10 further comprises a locking device 40 by means of which the charging socket cover 30 can be locked in the closed position. The locking device 40 comprises a ferromagnetic locking element 42, which is arranged on the side of the charging socket cover 30 opposite the pivot axis. The ferromagnetic locking element 42 is designed as a sheet metal element 43 made of so-called electrical steel. Furthermore, the ferromagnetic locking element 42 is arranged on the underside of the charging socket cover 30, with the permanent magnet 44 being arranged in the housing cover 13 below the locking element 42 with respect to the vertical direction.

[0027] The locking device 40 further comprises a permanent magnet 44, which is arranged on the housing cover 13 below the ferromagnetic locking element 42 in the housing cover 13 with respect to the installation position of the curb-loading device 15. This ensures that, in the closed position of the charging socket cover 30, the permanent magnet 44 is positioned opposite the ferromagnetic locking element 42 in the vertical direction, so that the ferromagnetic locking element 42 is operatively connected to the magnetic field of the permanent magnet 44, the permanent magnet 44 being oriented such that the magnetic attraction force attracts the locking element 42 and holds the charging socket cover 30 in the closed position.

[0028] The locking device 40 has a compression spring 32 which sits vertically in the housing cover 13 and is pre-tensioned against the underside of the charging socket cover 30 in the closed position of the charging socket cover 30.

[0029] The locking device 40 also includes an electromagnetic unlocking device 46 with an electromagnet 47 comprising a coil 48. The electromagnet 47 is arranged vertically adjacent to the permanent magnet 44 on the side of the permanent magnet 44 opposite the ferromagnetic locking element 42.

[0030] The locking device 40 further comprises a control unit 50, which is arranged in a liquid-tight electronics housing 52, which also houses the power electronics 54 of the charging device 10. The control unit 50 is configured to control the electromagnet 47 such that a magnetic field opposite to the magnetic field of the permanent magnet 44 can be generated, thereby canceling the magnetic attraction of the permanent magnet 44 acting on the ferromagnetic locking element 42. For this purpose, the electromagnet 47 is arranged such that its magnetic field is superimposed on the magnetic field of the permanent magnet 44, with the field lines of the two magnetic fields being oriented in opposite directions.As soon as the coil 48 of the electromagnet 47 is energized in an unlocking current direction, the permanent magnet 44 temporarily loses its attraction, so that the charging port cover 30 is unlocked and the charging port cover 30 can be opened by the user.

[0031] Due to the preload of the compression spring 32, the charging port cover 30 is lifted in the unlocked position, as shown in Figure 2b, thus signaling to the user that the charging port cover 30 can be opened. The compression spring 32 lifts the charging port cover 30 in opening direction A only to such an extent that, when the electromagnet 47 is switched off, the permanent magnet 44 pulls the charging port cover 30 back into the closed position.

[0032] The permanent magnet 44 is also dimensioned in such a way that its attractive force is approximately 80 N, so that it is not possible to open the charging socket cover 30 by hand.

[0033] Furthermore, the control device 50 is configured to control the electromagnet 47 in such a way that, with the charging socket cover 30 closed, a magnetic field oriented in the coil 48 opposite to the unlocking current direction can be generated, which additionally acts on the ferromagnetic locking element 42. This reverses the polarity of the electromagnetic field when the coil 48 is energized in the locking current direction compared to the electromagnetic field when the coil 48 is energized in the unlocking current direction, thereby increasing the holding force acting on the charging socket cover. Consequently, unauthorized manual opening from the outside is made more difficult.Furthermore, the control device 50 is designed to energize the coil 48 in the locking current direction when current is applied to the coil 48 in such a way that the coil 48 heats up, the heat generated thereby heating the charging socket cover 30 and / or the housing cover (13), which are preferably made of a thermally conductive material and thus protecting it, for example, from icing.

Claims

PATENT CLAIMS 1. Stationary charging device (10) for electrically charging a traction battery of a battery-electrically powered vehicle, comprising: - a charging socket (20) into which a vehicle-side charging plug can be inserted, - a movable charging port cover (30) which closes the charging port (20) in a closed position and releases it in an open position, and - a locking device (40) by means of which the charging socket cover (30) can be locked in the closed position, with • a ferromagnetic locking element (42), • a permanent magnet (44), wherein the permanent magnet (44) is arranged such that the ferromagnetic locking element (42) is held in the closed position of the charging socket cover (30) by the magnetic attraction of the magnetic field of the permanent magnet (30), • an electromagnetic unlocking device (46) with an electromagnet (47), and • a control device (50) which is configured to control the electromagnet (47) in such a way that a magnetic field opposite to the magnetic field of the permanent magnet (44) can be generated in order to overcome the magnetic attraction force acting on the ferromagnetic locking element (42) and thereby unlock the charging socket cover (30).

2. Stationary charging device (10) according to claim 1, wherein the ferromagnetic locking element (42) is arranged on the charging socket cover (30), and the permanent magnet (44) is arranged on a housing (12) of the charging device.

3. Stationary charging device (10) according to one of the preceding claims, which is designed as a curbside charging device (15).

4. Stationary charging device (10) according to one of the preceding claims, wherein the ferromagnetic locking element (42) comprises a sheet metal element (43).

5. Stationary charging device (10) according to claim 4, wherein the sheet metal element (43) is made of electrical steel.

6. Stationary charging device (10) according to one of the preceding claims, wherein the electromagnet (47) is arranged adjacent to the permanent magnet (44).

7. Stationary charging device (10) according to one of the preceding claims, wherein the permanent magnet (44) is dimensioned such that the magnetic attraction force is between 5 N and 150 N.

8. Stationary charging device (10) according to one of the preceding claims, wherein the electromagnet (47) has a coil (48), and wherein the control device (50) is configured to control the electromagnet (47) in such a way that, with the charging socket cover (30) closed, a magnetic field oriented in the same direction as the magnetic field of the permanent magnet (44) can be generated by setting a locking current direction in the coil (48), which also acts on the ferromagnetic locking element (42).

9. Stationary charging device (10) according to claim 8, wherein the control device (50) is configured to position the coil (48) in the to apply current in the locking direction such that the heat generated warms the charging socket cover (30).

10. Stationary charging device (10) according to one of the preceding claims, wherein a compression spring (32) is provided which the Charging port cover (30) is pre-tensioned in the opening direction (A).

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