Method for controlling a flap arrangement of a motor vehicle

Abstract

Method for controlling a flap assembly (1) of a motor vehicle, wherein the flap assembly (1) comprises a flap (2) and a drive assembly (3) for motor-driven adjustment of the flap (2), wherein the drive assembly (3) comprises at least one drive (4) with a drive motor (6), wherein the drive (4) is motionally coupled to the flap (2) and is designed to be reboundable, wherein the drive (4) comprises a transmission assembly (7) which is connected between the drive motor (6) and the flap (2) in terms of drive technology, wherein the transmission assembly (7) operates with a friction braking effect on the flap (2), wherein the drive assembly (3) comprises a drive control (8), and the drive motor (6) is operated by means of the drive control (8) in a holding mode of the flap assembly (1) to hold the flap (2) in place against a load acting on the flap (2) as a short-circuit brake and operates with a short-circuit braking effect on the flap (2).wherein in the holding mode the gear arrangement (7) and the drive motor (6) operate with a total braking effect on the flap (2), characterized in that in the holding mode for at least one load state of the flap (2) the proportion of the friction braking effect to the total braking effect is greater than the proportion of the short-circuit braking effect to the total braking effect.

Description

[0001] The invention relates to a method for controlling a flap arrangement of a motor vehicle according to the preamble of claim 1, a drive arrangement according to claim 12, and a flap arrangement according to claim 14.

[0002] The method in question is used for the motorized adjustment of any flaps or hatches of a motor vehicle. Such flaps or hatches can include, for example, tailgates, trunk lids, hoods, cargo floor panels, and also doors, especially sliding doors or side doors. In this context, the term "flap" or hatch is to be interpreted broadly.

[0003] The known method for controlling a retractable drive (DE 20 2017 105 031 U1), from which the invention is based, is equipped with a switching element that short-circuits the supply terminals of an electric motor in the event of a power failure. This short circuit only occurs in one adjustment direction of an associated flap of the motor vehicle, so that in an emergency the flap can be opened manually, while in the closing direction it is braked by the short circuit of the electric motor.

[0004] While the above method can be implemented with simple control technology, it only allows for limited control of the flap movement. One reason for this is that the short-circuit braking of the electric motor exerts a braking effect that depends on the flap's speed. Highly dynamic flap movements, such as gusts of wind, can be effectively absorbed. However, low-dynamic flap movements, such as those resulting from a gradual, gravity-induced closing of the flap, are only inadequately or not at all dampened.

[0005] The invention is based on the problem of designing and further developing the known method in such a way that a locking function is realized using simple means, which operates reliably regardless of the dynamics of the movement components of the flap to be locked.

[0006] The above problem is solved in a method according to the preamble of claim 1 by the features of the characterizing part of claim 1.

[0007] It has been proposed that a reliable locking of the flap can be achieved through a specific combination of a short-circuit braking effect and a friction braking effect, whereby the short-circuit braking effect primarily brakes the highly dynamic movement components and the friction braking effect brakes - at least also - the low-dynamic movement components.

[0008] Specifically, it is proposed that in the holding mode, for at least one load condition of the flap, the proportion of the friction braking effect to the total braking effect is greater than the proportion of the short-circuit braking effect to the total braking effect.

[0009] The term "locking" is to be interpreted broadly in this context. This means that locking the flap does not necessarily imply a complete blockage of the flap in the strict sense, but also includes a strong braking action.

[0010] The term "load state of the flap" encompasses all forces and torques acting on the flap that are not attributable to the drive mechanism. This includes spring forces, gravitational force, manual actuation forces, and the like. The load state in this sense also includes the flap position, as this significantly determines the aforementioned torques, particularly when the forces mentioned above are the weight of the flap.

[0011] The proposed solution takes into account the fact that the forces acting on a vehicle's tailgate can vary considerably. For example, gusts of wind striking the tailgate can lead to strong and highly dynamic load peaks. These load peaks can hardly be dampened by friction braking alone without the risk of the friction braking unduly hindering the motorized adjustment of the tailgate. Here, the proposed short-circuit braking effect comes into play, which is particularly pronounced during load peaks. In contrast, a gradual adjustment of the tailgate, as mentioned above, which can be caused, for example, by gravity, can hardly be dampened at all using the short-circuit braking principle. Here, the proposed friction braking effect comes into play, thus ensuring a high level of operational reliability for the locking function, regardless of the tailgate's load condition.

[0012] A further noteworthy aspect of the proposed solution is that, firstly, the friction braking effect in the locking mode is significantly stronger compared to the short-circuit braking effect, and secondly, the drive is designed with a return spring. This allows for manual adjustment of the flap at any time outside the locking mode, provided the friction braking effect is overcome. Simultaneously, a low short-circuit current is expected during the locking mode, enabling the components involved in setting the locking mode to be designed using simple means and thus cost-effectively.

[0013] In the preferred embodiment according to claim 2, in at least one load condition of the flap, a large part or even the entire part of the total braking effect is provided by the friction braking effect. As a result, the flap moves against a correspondingly large resistance in these cases.

[0014] In a further embodiment according to claim 3, which is particularly preferred, at least part of the frictional braking effect is generated by the internal friction in at least one gear stage of the gear arrangement. This can be implemented particularly easily from a design perspective if the gear stage is designed such that mechanical drive power is transmitted from the drive to the flap with low efficiency. According to claim 4, the low-efficiency gear stage can be a feed gear stage, wherein, in the preferred embodiment described therein, an intermediate gear stage for the locking operation must provide correspondingly less internal friction.

[0015] In the embodiment according to claim 5, a short circuit between two drive terminals of the drive motor, preferably pulsating, particularly within the framework of pulse-width modulation, can be created to generate the short-circuit braking effect. This allows considerable flexibility in the design of the short-circuit braking effect. Pulse-width modulation allows the short-circuit braking effect to be metered over a wide range.

[0016] The embodiments of claims 6 to 9 relate to preferred embodiments of a driver circuit for the drive motor. An H-bridge circuit is provided here, which has a braking circuit consisting of two normally open circuit breakers, so that the H-bridge circuit operates in hold-open mode without control currents or voltages for the circuit breakers. In an emergency according to claim 8, the flap assembly thus automatically engages the hold-open mode.

[0017] According to a further teaching as claimed in claim 12, which has independent significance, a drive arrangement for carrying out the proposed method is claimed. Reference may be made to all descriptions of the proposed method that are suitable for explaining the drive arrangement.

[0018] A particularly preferred embodiment of the drive arrangement relates to claim 13. Here, the power switches providing the brake circuit are preferably designed as relays, while the other power switches are preferably designed as MOSFETs. This is advantageous because relays can readily be designed to be robust with regard to potential peak short-circuit currents.

[0019] According to a further teaching as described in claim 14, which has independent significance, a flap arrangement of a motor vehicle with a proposed drive arrangement is claimed. Reference may be made to all descriptions of the proposed method and the proposed drive arrangement.

[0020] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment. The drawing shows Fig. 1. The rear of a motor vehicle in a side view with a tailgate and a proposed drive arrangement for carrying out a proposed procedure, Fig. 2 a drive of the drive arrangement according to Fig. 1 in a longitudinal section, and Fig. 3 a driver circuit of the drive control of the drive arrangement according to Fig. 1 for operating the drive motor.

[0021] The in Fig. The motor vehicle shown is equipped with a flap. 2 and with a drive arrangement 3 for motorized adjustment of the flap 2 equipped. The drive arrangement 3 has at least one drive 4 In the illustrated and thus preferred embodiment, two drives are used. 4 provided for, on both sides of one of the flaps 2 assigned flap opening 5 are arranged. For the sake of simplicity, the following description will only refer to a single drive. 4 The speech. All related statements apply accordingly to any further, potentially planned drive system.

[0022] The proposed procedure concerns a control mechanism for the above flap arrangement, which will be explained in more detail later. 1 of the motor vehicle.

[0023] The drive 4 features a drive motor 6on, which is supplied with electrical drive power in a manner yet to be explained, in order to open the flap 2 to understand motor skills.

[0024] Here, and preferably, the flap is involved. 2 about a tailgate. However, the proposed solution is also applicable to all other flaps mentioned in the introductory part of the description. All details regarding the flap shown, designed as a tailgate. 2 The same applies to all other types of valves.

[0025] The drive 4 is with the flap 2 motion-coupled. In general, the drive motor can 6 bidirectional or unidirectional with the flap 2 be motion-coupled. This motion coupling allows the flap to 2 by means of the drive 4to open and / or close by motor. This motion coupling also works in reverse. The drive is used for this purpose. 4 It is designed to be retractable. This means that initiating movement into the valve... 2 to a reversing of at least part of the drivetrain between the drive motor 6 and the flap 2 leads.

[0026] The drive 4 features a gear arrangement 7 up, which is technically between the drive motor 6 and the flap 2 is switched. In drive technology terms, this means that the drive movements of the drive motor are being carried out. 6 through the gearbox arrangement 7 on the flap 2 can be transferred.

[0027] The gearbox arrangement 7 acts on the flap with a friction braking effect. 2 This means, in particular, that one into the flap 2movement initiated by the gear arrangement 7 braking is achieved through friction braking.

[0028] As proposed, the drive arrangement 3 a drive control 8 on, which in Fig. 3 is shown. The drive motor 4 is controlled by means of the drive control 8 in a locked position of the flap arrangement 1 It is operated as a short-circuit brake and works with a short-circuit braking effect on the flap. 2 The short-circuit braking effect also works here, one of the flaps being the one that engages. 2 initiated movement.

[0029] In locking mode, the gear arrangement operates 7 and the drive motor 6 with an overall braking effect on the flap 2 It is essential that, in the holding mode, the flap is protected against at least one load condition. 2the proportion of friction braking effect to the total braking effect is greater than the proportion of short-circuit braking effect to the total braking effect.

[0030] A stress condition of the valve 2 is in Fig. 1 is shown as an example. Here, only the force of gravity and the spring force of the [unclear] are at work. Fig. 2 spring arrangement shown 9 on the flap which is in an open position 2 The spring arrangement 9 This drive is designed here, preferably as a linear drive. 4 into its extended position, so that the spring arrangement 9 the flap 2 against the force of gravity, it moves in the opening direction. It is assumed here that the force of gravity predominates, so that the flap... 2 The entire flap is driven in its closing direction. In holding mode, the overall braking effect ensures that the flap remains closed. 2their respective disclosures.

[0031] In the aforementioned stress state of the flap 2 Preferably, the majority of the total braking effect is provided by friction braking. Specifically, preferably more than 60%, further preferably more than 70%, and particularly more than 90% of the total braking effect is provided by friction braking.

[0032] The above design ensures that only a minimal short-circuit braking effect is required for the holding-open function. This results in a comparatively low short-circuit current, effectively protecting the electrical components from overheating.

[0033] The friction braking effect is at least partially due to the internal friction in at least one gear stage of the gear arrangement. 7This creates something that is easy to implement in terms of design. The degree of friction braking can be easily adjusted via the efficiency of the respective gear stage. The efficiency of the gear stage and / or the gear arrangement 7 is preferably less than 80%, more preferably less than 70%, and particularly less than 50%. The relevant gear stage or gear arrangement 7 In a particularly preferred embodiment, the design incorporates a self-locking mechanism. However, care must be taken to ensure that self-locking is not achieved, in order to maintain the reversibility of the drive. 4 to ensure.

[0034] As in Fig. As shown in 2, the gear arrangement 7 a feed gear stage 11 , preferably a linear drive, in particular a spindle-spindle nut drive, for generating drive movements. As shown in the illustration Fig. 2 can also be seen that the feed gear stage 11 an intermediate gear stage 10 is integrated upstream of the drive system. A particularly gentle motor adjustment is achieved by minimizing the internal friction of the feed gear stage. 11 greater than the internal friction of the intermediate gear stage 10 is.

[0035] For hold-open operation, a short circuit between at least two electrical supply connections is preferably used. 12 of the drive motor 6 , possibly via a braking resistor 13 , preferably pulsed, is produced. Generally speaking, a voltage is induced between the supply terminals according to the principle of induction. 12 induced as soon as the drive motor 6 is manually retracted. 12 Now electrically connected, water flows between the supply connections. 12 a short-circuit current.

[0036] The term "short circuit" is always to be understood broadly in this context, since it also includes a braking resistor mentioned above. 13 It can be switched into such a short circuit. The resulting short-circuit current induces a magnetic field in the windings of the drive motor. 6 , which counteracts the original movement, corresponding to the short-circuit braking effect. The faster the movement of the flap. 2 The larger the current, the greater the short-circuit current and the resulting short-circuit braking effect.

[0037] Preferably the drive 4 by means of the drive control 8 a driver circuit 14 to supply the drive motor 6 with electric drive power. The driver circuit is... 14 with electrically activated circuit breakers 15Equipped for switching the drive power. The term "circuit breaker" means that this component is used for switching electrical drive power for the drive motor. 6 serves.

[0038] Furthermore preferably at least one of the circuit breakers 15 as an opening circuit breaker 16 designed as in Fig. 3 is indicated. The driver circuit represents 14 a brake circuit 17 ready, in which the aforementioned short circuit is prevented by deactivating at least one of the opening circuit breakers 16 is manufactured. Normally open circuit breakers are those that close in a deactivated state (i.e., an uncontrolled state) and only open in an activated state (i.e., a controlled state). Normally closed circuit breakers behave in the opposite way. 20 .

[0039] For the in Fig. 3 shown driver circuit 14 This means that the hold-open operation is achieved by deactivating the circuit breakers. 15 This is achieved. Therefore, the hold-open mode is automatically activated if the circuit breakers are not activated. 15 This is done. It follows in particular that in the event of a power supply failure, which will be addressed later, U the flap arrangement 1 The locking operation is automatically discontinued.

[0040] Here, and preferably, the driver circuit forms 14 an H-bridge circuit with the high-side 18 and low-side 19 from which two circuit breakers each operate in the usual manner 15 for controlling the drive motor 6 exhibiting such characteristics. With such an H-bridge circuit, bidirectional control of the drive motor, designed as a DC motor, can be achieved in a known manner. 6 to reach.

[0041] Preferably, this consists of two open circuit breakers. 16 one of the pages 18 , 19 the H-bridge circuit and the brake circuit 17 preferably at least two normally closed circuit breakers form 20 the other side of the H-bridge circuit. In hold-open mode, the two closing circuit breakers are 20 As mentioned above, it is deactivated.

[0042] Advantageously, the following are used as opening circuit breakers: 16 Relays are used that are particularly robust with regard to potential short-circuit current spikes. Normally closed relays, which provide the function of a normally open circuit breaker, are suitable here. Alternatively, transistors, especially depletion-type MOSFETs, can be used. The normally closed circuit breakers 20are preferably designed as transistors, in particular as enhancement-type MOSFETs. Here, and preferably, two MOSFETs and two relays form an H-bridge circuit.

[0043] As mentioned above, in the event of a power supply failure U for the flap arrangement 1 , which are connected via the supply lines 12 the drive power to the drive motor 6 when the locking mode is activated.

[0044] To prevent unwanted locking of the flap 2 To prevent this, the flap arrangement 1 preferably an emergency switch 21 on, by whose activation the short-circuit braking effect of the drive motor 6 is cancelled.

[0045] Preferably the emergency switch 21 in a crash situation through the control arrangement 8 triggered. In the case of the Fig.However, in the illustrated embodiment 1, the emergency switch 21 It is manually operated. This is because the emergency stop switch 21 here and preferably in the brake circuit 17 When the brakes are switched on, the braking operation can be stopped by pressing the emergency stop button. 21 pick up easily.

[0046] According to another doctrine, which is also of independent importance, a drive arrangement 3 claimed for carrying out the proposed procedure. All of the above statements relating to the drive arrangement are excluded. 3 Reference may be made to applicable provisions.

[0047] According to another doctrine, which is also of independent importance, a flap arrangement 1 with a proposed drive arrangement 3 claimed. All of the above statements relating to the flap arrangement are excluded. 1 Reference may be made to applicable provisions. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 202017105031 U1

[0003]

Claims

[1] Method for controlling a flap arrangement (1) of a motor vehicle, wherein the flap arrangement (1) comprises a flap (2) and a drive arrangement (3) for motor-driven adjustment of the flap (2), wherein the drive arrangement (3) has at least one drive (4) with a drive motor (6), wherein the drive (4) is designed to be motionally coupled to the flap (2) and to be reboundable, wherein the drive (4) has a gear arrangement (7) which is connected between the drive motor (6) and the flap (2) in terms of drive technology, wherein the gear arrangement (7) operates with a friction braking effect on the flap (2), wherein the drive arrangement (3) has a drive control (8), and the drive motor (6) is operated by means of the drive control (8) in a holding mode of the flap arrangement (1) to hold the flap (2) against a load acting on the flap (2) as a short-circuit brake and operates with a short-circuit braking effect on the flap (2), in the holding mode the gear arrangement (7) and the drive motor (6) operate with a total braking effect on the flap (2), characterized by , that in the holding operation for at least one load condition of the flap (2) the proportion of the friction braking effect to the total braking effect is greater than the proportion of the short-circuit braking effect to the total braking effect. [2] Method according to claim 1, characterized by, that in at least one load condition of the flap (2) more than 60%, preferably more than 70%, further preferably more than 90%, of the total braking effect is provided by the friction braking effect. [3] Method according to claim 1 or 2, characterized by , that the friction braking effect is generated at least partly by the internal friction in at least one gear stage of the gear arrangement (7), preferably that the efficiency of the gear stage and / or the gear arrangement (7) is less than 80%, preferably less than 70%, more preferably less than 50%. [4] Method according to any one of the preceding claims, characterized by, that the gear arrangement (7) has a feed gear stage (11) for generating drive movements and an intermediate gear stage (10) which is upstream of the feed gear stage (11) in terms of drive technology, preferably that the internal friction of the feed gear stage (11) is greater than the internal friction of the intermediate gear stage (10). [5] Method according to any one of the preceding claims, characterized by , that in the holding mode, a short circuit is created between at least two electrical supply terminals (12) of the drive motor (6), preferably pulsating, to generate the short-circuit effect. [6] Method according to claim 5, characterized by, that the drive control (8) has a driver circuit (14) for supplying the drive motor (6) with electrical drive power, which has electrically activatable power switches (15) for switching the drive power and that at least one of the power switches (15) is designed as an opening power switch (16), preferably that the driver circuit (14) provides a braking circuit (17) in which the short circuit is created by deactivating at least one of the opening power switches (16). [7] Method according to claim 6, characterized by, that the driver circuit (14) forms an H-bridge circuit with the sides high-side (18) and low-side (19), each having two power switches (15) for controlling the drive motor (8), preferably that two normally open power switches (16) form one of the sides of the H-bridge circuit and the brake circuit (17), further preferably that at least two normally closed power switches (20) form the other side of the H-bridge circuit and that in the holding operation the two normally closed power switches (20) are deactivated. [8] Method according to any one of the preceding claims, characterized by , that the flap assembly (1) is always operated in hold-open mode in an emergency in which the electrical supply voltage (U) of the flap assembly (1) has failed. [9] Method according to claim 6 or 7 and according to claim 8, characterized by, that in the normal case, in which the flap assembly (1) is supplied by an electrical supply voltage (U), a drive current flows for the motor adjustment of the flap (2) through a deactivated opening power switch (16) and an activated closing power switch (20). [10] Method according to any one of the preceding claims, characterized by , that the flap arrangement (1) has an emergency switch (21) by actuating which the short-circuit braking effect of the drive motor (8) is cancelled. [11] Method according to claims 6 and 10, characterized by , that the emergency switch (21) is connected to the brake circuit (17). [12] Drive arrangement for carrying out a method according to one of the preceding claims. [13] Drive arrangement according to claim 12, characterized by, that at least one of the opening power switches (16) is designed as a relay, in particular as a normally closed contact relay, or as a transistor, in particular as a depletion-type MOSFET, and / or that one of the closing power switches (20) is designed as a transistor, in particular as an enhancement-type MOSFET. [14] Valve arrangement with a drive arrangement (3) according to claim 12 or 13.