Loading flap system for a motor vehicle

Abstract

Such a loading flap system is known, comprising a loading flap movable between a closed position that closes a vehicle-side loading recess and an open position that releases the loading recess, an electric drive device that moves the loading flap between the open position and the closed position, an electronic control unit for controlling the drive device, a locking device that is provided for locking or releasing the loading flap in its closed position, and a monitoring device for detecting a locked or unlocked state of the loading flap in its closed position. According to the invention, the electronic control unit is associated with a monitoring system which includes a control function of the control unit and a monitoring function of the locking device, which interact with each other in such a way that the control function moves the loading flap in the direction of the opening position when the loading flap is in the closed position, and that the monitoring function detects parameters in a time-dependent manner that allow the locked or unlocked state of the loading flap to be recognized in the closed position. Application for passenger cars with electric drive

Description

[0001] The invention relates to a loading flap system for a motor vehicle with a loading flap that is movable between a closed position closing a vehicle-side loading recess and an open position releasing the loading recess, with an electric drive device that moves the loading flap between the open position and the closed position, with an electronic control unit for controlling the drive device, with a blocking device, in particular electrically actuable, which is provided for locking or releasing the loading flap in its closed position, and with a monitoring device for detecting a locked or unlocked state of the loading flap in its closed position.

[0002] Such a charging flap system is generally known for motor vehicles with an electric drive. A corresponding motor vehicle has a vehicle-mounted charging bay equipped with a socket for inserting a charging plug of a charging cable. The charging bay is closable by a charging flap that is movably mounted relative to the motor vehicle between a closed position covering the charging bay and an open position exposing the charging bay. An electric drive device is provided for moving the charging flap between the closed and open positions. In the closed position of the charging flap, the charging flap can be locked relative to the charging bay by means of a linear actuator. The electric drive device for moving the charging flap is controlled by an electronic control unit.The linear actuator is also assigned a sensor that detects whether the linear actuator is holding the tailgate in the locked position. The corresponding sensor works in conjunction with a vehicle-mounted control unit.

[0003] The object of the invention is to create a loading flap system of the type mentioned above which enables secure locking of the loading flap to the loading trough independently of a connection to vehicle-side control units.

[0004] This object is achieved in that a monitoring system is assigned to the electronic control unit as a monitoring device, said monitoring system comprising a control function of the control unit and a monitoring function for the blocking device, which interact with one another in such a way that the control function moves the loading flap in the direction of the open position when the loading flap is in the closed position, and in that the monitoring function records parameters, in particular electrical parameters, over time, which indicate the locked or unlocked state of the loading flap in the closed position. According to the invention, autonomous monitoring of the loading flap system is achieved without the need for an external, vehicle-mounted control unit. According to the invention, when the loading flap is in the closed position, the drive device for the loading flap is controlled in such a way that the loading flap is moved in the direction of the open position.At the same time, the monitoring function records parameters that indicate whether the locked state of the tailgate in its closed position, achievable by the blocking device, has been reached or not. The monitoring function and the control function can be provided in hardware or software. The solution according to the invention eliminates the need for external sensors connected to a vehicle-mounted control unit. The electronic control unit for the tailgate drive device is advantageously coupled to an electronic control system for the drive system such that starting the drive system is only possible once the monitoring system has determined that the tailgate is locked in its closed position.The opening movement of the tailgate from its closed position occurs only over a limited time and a limited distance, which is sufficient to determine whether the tailgate is locked in its closed position or not. The solution according to the invention is particularly advantageous for passenger cars with an electric drive, whether as a purely electric drive or as a hybrid drive. It is essential for the solution according to the invention that a power storage system such as a battery arrangement or an accumulator arrangement is designed to be rechargeable.

[0005] In one embodiment of the invention, a sensor system is provided that detects a change in the position of the tailgate after activation of the control function and is connected to the electronic control unit. The corresponding sensor system can be formed by a Hall sensor, which can be assigned to a pivot axis of the tailgate, provided the tailgate is mounted so that it can pivot relative to the loading cradle.

[0006] In a further embodiment of the invention, a force sensor is assigned to the tailgate, which is coupled to the monitoring function to transmit time-dependent force values ​​to the monitoring function. The force sensor can detect an increased force if the tailgate encounters a positive resistance during its opening movement from the closed position, namely the locking mechanism. This increase in force can be evaluated over time.

[0007] In a further embodiment of the invention, the monitoring function is designed to detect current change parameters of the electric drive device over time. This embodiment is based on the finding that moving the tailgate from the closed position toward the open position using the electric drive device results in increased power consumption if the tailgate hits a locked stop of the locking device during an opening process.

[0008] In a further embodiment of the invention, a change in current level is provided as the current change parameter, which can be evaluated by the control unit of the drive device. When the charging flap is controlled from the closed position towards the open position over a limited period of time, in particular a period of 250 ms, a significant change in current level occurs if the charging flap moves against the locked stop. This signals to the control unit of the drive device that the charging flap is locked in its closed position, so that the control unit can send a corresponding signal to a control system of the motor vehicle's drive system, indicating that the drive system can be started. If a corresponding opening movement of the charging flap does not result in a significant increase in current consumption, the control unit concludes that the charging flap is not locked in the closed position.Accordingly, there is no release signal for starting the drive.

[0009] In a further embodiment of the invention, a current phase change is provided as the current change parameter, which can be evaluated by the control unit of the drive device. This embodiment is advantageous for an electric drive device that has an electric drive motor that is operated either with multi-phase direct current or with alternating or three-phase current. Within the specified period of the opening movement of the tailgate, the temporal sequence and magnitude of the amplitudes of the current phases can change. Alternatively, the number of zero crossings of corresponding current phase curves can change.

[0010] In a further embodiment of the invention, a change in a current ripple is provided as the current change parameter, which can be evaluated by the control unit of the drive device. Here, too, different scenarios arise depending on whether the tailgate is locked in its closed position or not.

[0011] In a further embodiment of the invention, the electronic control unit is embodied as a data processing system, and the control function and the monitoring function are configured as a data processing program stored in a memory of the electronic control unit. The memory can be implemented as a data carrier coupled to the electronic control unit or as a memory integrated into the electronic control unit that becomes usable upon electrical activation. Preferably, the data processing system is configured as a microcontroller in which appropriate software is programmed to implement the functions of a monitoring system.

[0012] In a further embodiment of the invention, the electronic control unit is coupled to a drive control system of the motor vehicle in such a way that if an unlocked tailgate is detected in the closed position of the tailgate, the drive system is blocked from starting. This embodiment is an important safety feature for the operation of a motor vehicle with an electric drive system.

[0013] Further advantages and features of the invention emerge from the claims and from the following description of a preferred embodiment of the invention, which is illustrated by the drawings. Fig. 1 to 7 schematically show an embodiment of a loading flap system according to the invention for a passenger car in different functional positions and Fig. 8 a diagram of a time course of several voltages of a three-phase alternating current system and a pulsating direct current system of an electric motor in the form of a three-phase machine for a drive device of the loading flap system according to the Fig. 1 to 7.

[0014] The drive device preferably comprises a brushless DC motor powered by direct current, which in turn is generated from alternating current or three-phase current by a rectifier. Preferably, a pulsating direct current is generated, in which the frequency and amplitude change over time as the current intensity changes. This effect is utilized according to the invention to detect whether the tailgate is locked or unlocked.

[0015] A loading flap system according to the Fig. 1 to 7 comprises a charging cradle 1 mounted on the vehicle, which defines a receiving space 2 in which one or more charging sockets are arranged in a manner not shown in detail. The charging sockets are connected to a vehicle-mounted power storage unit, which is intended to supply an electric drive system of the passenger car.

[0016] The receiving space 2 of the loading trough 1 can be closed by a loading flap 3, which is mounted on one side of the receiving space 2 on the loading trough 1 and thus on the vehicle side so as to be pivotable about a pivot axis S between a Fig. 1 shown opening position and one in Fig. 3. The tailgate 3 is displaced between the open position and the closed position in both directions of rotation by means of an electric drive device 4. The electric drive device 4 has an electric drive motor, which can be designed as a brushless DC motor. Alternatively, the electric drive motor can be a three-phase motor or an AC motor. The electric drive device 4 is supplied with power by a vehicle-mounted battery, in particular by the power storage unit, which also supplies the electric drive.

[0017] In its closed position, the tailgate 3 is also assigned a blocking device 7, which has a linearly displaceable locking bolt 8. The blocking device 7 can be operated pneumatically, hydraulically, mechanically, or electrically to move the locking bolt 8 between a locked position and a release position. The locking bolt 8 interacts with a locking receptacle 9 on the tailgate 3. The locking receptacle 9 has a clear cross-section that is larger than a cross-section of the locking bolt 8, so that the tailgate 3 remains pivotally movable to a limited extent even in the locked state, in which the locking bolt 8 is inserted into the locking receptacle 9 of the tailgate 3 in its closed position.

[0018] To control the electric drive device 4, an electronic control unit St is provided, which according to Fig. 5 is coupled to a controller F of the electric drive of the passenger car. The coupling is provided in such a way that the electric drive is only released for start by the controller F when the electronic control unit St has signaled to the controller F that the loading flap 3 is in a locked state in its closed position. According to the invention, the locked or unlocked state is not detected by an external sensor system assigned to the blocking device 7 or the locking bolt 8. Rather, the locked or unlocked state is monitored directly via the electronic control unit St. For this purpose, the electronic control unit St has a monitoring system which is stored as a two-part data processing program in a memory of the electronic control unit St. The electronic control unit St is designed as a microcontroller.A control stage of the monitoring system serving as a control function 5 is provided to control the drive device 4 in the closed position of the loading flap 3 in such a way that the loading flap 3 moves from the closed position according to the arrow A (. Fig. 4 to 7) is driven towards the opening position.

[0019] In addition, the monitoring system has a second software level as a monitoring function 6, which monitors current change parameters of the power supply of the electric drive device 4 in a time-dependent manner over a limited period of time, preferably 250 ms.

[0020] This results in two scenarios: If the locking bolt 8 is correctly moved into its locking position blocking the loading flap 3 in accordance with the Fig. 4 and Fig. 5, then the tailgate 3, during a corresponding opening movement in the direction of arrow A, runs against a stop formed by an edge of the locking receptacle 9 and by the locking bolt 8. The monitoring function 6 of the electronic control unit St detects that when the tailgate 3 hits the stop, the electric drive device 4 requires a greatly increased current consumption in order to overcome the stop. The corresponding current change is detected by the monitoring function 6 of the electronic control unit St and evaluated in the electric control unit St in such a way that the locked state of the tailgate 3 is confirmed. This leads to a corresponding signal to the control F of the electric drive, so that the electric drive can be started.

[0021] If, according to the Fig. 6 and Fig. 7 the locking bolt 8 is not retracted into the locking receptacle 9 of the loading flap 3 in its closed position, then the activation of the drive device 4 by the control function 5 of the electronic control unit St in the direction of the open position over a limited period of time, preferably 250 ms, does not lead to any significant change in current, since the locking receptacle 9 does not run against a stop. This scenario is also evaluated in the electronic control unit St and recorded as an unlocked state of the loading flap 3. The electronic control unit St accordingly transmits a signal to the control F of the electric drive of the passenger car that the loading flap 3 is not yet locked in its closed position, so that the electric drive is also not released for start.

[0022] Based on the Fig. Figure 8 shows a schematic time diagram of three voltage phases of a three-phase motor, from which one can read the frequency of the corresponding sinusoidal curves of the three voltages U1, U2, and U3, as well as the amplitudes and corresponding zero crossings of the sinusoidal curves. For a pulsating direct current, the corresponding truncated wave crests are only visible above the zero line according to Fig. 8. Here, too, the frequency of the wave crests as well as the amplitude of the wave crests and the impact of the wave crests on the zero line can be recorded, so that with corresponding current changes, analogous frequency changes, amplitude changes or changes in the zero line contact occur over time or over corresponding revolutions of an output shaft of the electric motor. A schematic representation of a corresponding pulsating DC diagram is shown in dashed lines in Fig. 8 inserted.

Claims

[1] Loading flap system for a motor vehicle with a loading flap (3) movable between a closed position closing a vehicle-side loading recess (1) and an open position releasing the loading recess (1), with an electric drive device (4) which displaces the loading flap (3) between the open position and the closed position, with an electronic control unit (St) for controlling the drive device, with a blocking device (7), in particular electrically actuable, which is provided for locking or releasing the loading flap (3) in its closed position, and with a monitoring device for detecting a locked or unlocked state of the loading flap (3) in its closed position, characterized bythat the electronic control unit (St) is assigned a monitoring system (5, 6) as a monitoring device, which monitoring system comprises a control function (5) of the control unit (St) and a monitoring function (6) for the blocking device, which interact with one another in such a way that the control function (5) moves the loading flap (3) in the closed position in the direction of the open position, and that the monitoring function (6) records parameters, in particular electrical parameters, in a time-dependent manner, which allow the locked or unlocked state of the loading flap (3) to be recognized in the closed position. [2] Loading flap system according to claim 1, characterized by that a sensor system is provided which detects a change in position of the loading flap (3) after activation of the control function (5) and which is connected to the electronic control unit (St). [3] Loading flap system according to claim 2, characterized bythat the loading flap (3) is assigned a force sensor which is coupled to the monitoring function (6) in order to transmit time-dependent force values to the monitoring function (6). [4] Loading flap system according to claim 1, characterized by that the monitoring function (6) is designed to detect current change parameters of the electric drive device (4) in a time-dependent manner. [5] Loading flap system according to claim 4, characterized by that a change in current level is provided as the current change parameter, which can be evaluated by the control unit (St) of the drive device (4). [6] Loading flap system according to claim 4, characterized by that a current phase change is provided as the current change parameter, which can be evaluated by the control unit (St) of the drive device (4). [7] Loading flap system according to claim 4, characterized bythat a change in a current ripple is provided as the current change parameter, which can be evaluated by the control unit (St) of the drive device (4). [8] Loading flap system according to one of the preceding claims, characterized by that the electronic control unit (St) is designed as a data processing system, and that the control function and the monitoring function (6) are integrated in a data processing program which is stored in a memory of the electronic control unit (St). [9] Loading flap system according to one of the preceding claims, characterized by that the electronic control unit (St) is coupled to a drive control (F) of the motor vehicle in such a way that when an unlocked loading flap (3) is detected in the closed position of the loading flap (3), the start of the drive is blocked.

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