The invention relates to a drive arrangement for motor-operated adjustment of a closure element in a motor vehicle, and to a closure element arrangement in a motor vehicle.
The term “closure element” is to be understood here in an inclusive fashion. It includes tailgates, trunk lids, engine hoods, side doors, sliding doors, lifting roofs, sliding windows, etc.
However, the drive arrangement in question is primarily applied in tailgates and side doors in motor vehicles. It serves for motor-operated adjustment of the respective closure element in the closing direction and in the opening direction.
The known drive arrangement (DE 20 2005 007 155 U1) on which the invention is based is assigned to a tailgate of a motor vehicle. The drive arrangement is equipped with two spindle drives which each have, in a compact structural unit, a drive motor, an intermediate transmission with a clutch and a spindle/spindle nut mechanism. A spring arrangement, which counteracts the weight of the assigned tailgate, is provided in the respective structural unit.
The known drive arrangement also has a drive controller which serves to actuate the two drives, in particular the two drive motors. The drives are generally each configured with a sensor for sensing the drive movement. Tailgates of considerable size and/or considerable weight can be adjusted by motor with the known drive arrangement. This opens new degrees of freedom in the configuration of such tailgates. However, the increase in the weight basically also involves an increased risk when the drive arrangement fails.
In the most unfavorable case, the drive connection between the drive arrangement and the tailgate ruptures, which would cause the tailgate to suddenly slam shut. This involves overall a considerable restriction of the operational safety of the tailgate arrangement.
The invention is based on the problem of configuring and developing the known drive arrangement in such a way that the operational safety is increased.
The above problem is solved in a drive arrangement for motor-operated adjustment of a closure element in a motor vehicle, wherein at least one drive with a drive motor, and a drive controller are provided, wherein the closure element can be driven in the motor-operated adjustment mode by means of the drive motor in the closing direction and in the opening direction between a closed position and an open position, wherein the drive is of non-self-locking design, wherein the drive has a sensor, in particular a Hall sensor, for sensing the drive movement, wherein the drive controller monitors the sensor signals for a fault state, and when a fault state is sensed said drive controller initiates an emergency braking mode and/or an emergency stop mode, in that the drive arrangement comprises two drives each with a sensor for determining the respective drive movement, and in that, in order to detect fault-induced slamming shut of the closure element, the drive controller correlates the sensor signals of the two sensors with one another, in particular compares said sensor signals with one another.
It is essential that the drive controller monitor the sensor signals of the sensor or of the sensors of the drive or drives for a fault state and initiate an emergency braking mode and/or an emergency stop mode when a fault state is detected. It has been realized here that the sensor signals which serve to control the movement per se can be used to detect deviations from the normal operating state.
In one embodiment, the fault state which is to be monitored relates to fault-induced slamming shut of the closure element. This fault state is in the spotlight here.
In particular, the teaching is based on the fault state in which one of the two drives of the drive arrangement becomes disengaged from the closure element, which in turn leads to fault-induced slamming shut of the closure element. This fault state is detected according to the proposal in that the sensor signals of the two sensors are correlated with one another. In the simplest case, a comparison of the sensor signals of the two sensors takes place here.
In another embodiment, it has been detected that the drive motor or drive motors of the drive or drives can readily be actuated in such a way that the braking effect which is necessary for the emergency braking mode or the emergency stop mode is brought about.
There are, at any rate, two possible ways of generating the abovementioned braking effect of the drive motor.
One way is to connect the drive motor to a short circuit, preferably in a pulsed fashion. As a result, a braking effect is generated which is due to the Lorentz force.
Another way of generating the braking effect of the drive motor is to apply a preferably pulsed countervoltage and/or a preferably pulsed countercurrent to the drive motor. As a result, an even stronger braking effect than with the short-circuit braking can be achieved.
According to a further teaching, which is also attributed independent significance, a closure element arrangement which has a closure element on one hand and a drive arrangement on the other is claimed as such. Reference can be made to the full scope of the statements relating to possible variants of the closure element and of the drive arrangement.
Further details, features, objectives and advantages of the present invention will be explained in more detail below with reference to the drawing of a preferred exemplary embodiment. In the drawing:
The drive arrangement illustrated in
Basically, a single drive 2 can be assigned to the drive arrangement. However, the drive arrangement illustrated in
The following statements apply almost consistently only to the drive 2 which can be seen in
It can be stated in respect of the above that in specific application cases a single drive motor 3 can be assigned to a plurality of drives 2, preferably two thereof. The plurality of drives 2 then, as it were, share the one drive motor 3.
In addition, a drive controller 5 is provided which is assigned to the drive 2 or the drives 2. Said drive controller 5 will be explained in more detail below.
All the exemplary embodiments have in common the fact that the tailgate 1 can be driven in the motor-operated adjustment mode by means of the drive motor 3 in the closing direction and in the opening direction between a closed position and an open position.
In the mounted state, the arrangement is such that the weight of the closure element 1 acts in the closing direction. In this case, the drives 2 are not configured here in a self-locking way, with the result that the weight of the closure element 1 can basically trigger a closing movement of the closure element 1. In order to prevent this, a prestressing of the drives 2 and/or of the closure element 1 is generally provided, as will be explained.
The drive 2 is equipped with a sensor (not illustrated) for sensing the drive movement. The sensor is preferably a Hall sensor which interacts with a magnet arranged on a drive shaft.
It is essential that the drive controller 5 monitor the sensor signals for a fault state and initiate an emergency braking mode and/or an emergency stop mode when a fault state is detected.
There is primarily provision here that the drive controller 5 monitors the sensor signals for fault-induced slamming shut of the closure element 1. Such fault-induced slamming shut can be caused, in particular, by a drive component of the drive arrangement rupturing. It will be explained further below which drive component this may be.
Specifically when a drive component ruptures, the slamming shut movement will take place suddenly. Against this background, there is preferably provision that, in order to detect fault-induced slamming shut of the closure element 1, the drive controller 5 checks the sensor signals for sudden signal deviations. By way of clarification it can be stated in this respect that this means a deviation with respect to the signal profile occurring in the normal operating mode.
It has already been mentioned further above that fault-induced slamming shut of the closure element 1 may be due to the fact that one of the drives 2 becomes disengaged from the closure element 1. This is the case in the illustrated exemplary embodiment if, during the loading when the tailgate 1 is opened, a strong shock is inadvertently applied to one of the drives 2, which shock ruptures the drive coupling between the drive 2 and the tailgate 1 and/or the motor vehicle bodywork. This generally causes the tailgate 1 to slam shut owing to the weight of the tailgate.
For the above case it is appropriate that the drive arrangement 5 initiates an emergency braking mode and/or an emergency stop mode only for that drive 2 which follows the fault-induced slamming shut movement of the tailgate 1. This method of actuation is particularly advantageous for a case in which the emergency braking mode and/or the emergency stop mode is due to inverse energization of the drive 2, as will be explained.
In the drive arrangement with two drives 2, which each have a sensor, the detection of fault-induced slamming shut of the closure element 1 can be implemented by virtue of the fact that the sensor signals of the two sensors are correlated with one another. This means that the sensor signals of the two sensors are processed with one another in some way or other, so that the presence of the fault state can be detected from the result of the processing.
In the simplest case, the sensor signals of the two sensors are largely identical to one another in the normal operating mode. This is also the case in the illustrated exemplary embodiment with identical drives 2. In particular it is sufficient that the sensor signals of the two sensors are compared with one another, wherein the upward transgression of a predetermined signal deviation implies the occurrence of the fault state.
However, there may, for example, also be provision that, in order to detect fault-induced slamming shut of the closure element 1, the drive controller 5 monitors the upward transgression of a predetermined limiting difference in the drive speed or the drive travel experienced by the two drives 2. Other possible ways of detecting the fault state are conceivable.
There is preferably provision that the drive 2 is prestressed in the opening direction, specifically in such a way that the prestressing counteracts the weight of the tailgate 1. This will be explained in more detail below. Such prestressing generally leads, in the case of the above “tearing off” of a drive 2, to a situation in which the drive 2 carries out a sudden drive movement in the opening direction due to the prestressing. Against this background, there is preferably provision that the drive controller 5 monitors the sensor signals for the fault state of a sudden drive movement in the opening direction which is caused, in particular by prestressing of the drive 2.
In this context there is also preferably provision that the drive arrangement 5 initiates an emergency braking mode and/or emergency stop mode only for that drive 2 for which no sudden drive movement in the opening direction has just been sensed.
Various possible ways of implementing the emergency braking mode and the emergency stop mode are conceivable.
For example, it is conceivable that the drive arrangement has an actuable brake arrangement, and that, in order to initiate the emergency braking mode and/or the emergency stop mode, the drive controller 5 correspondingly actuates the brake arrangement. Given corresponding configuration of the brake arrangement, the necessary braking effect can be achieved quickly and reliably.
In a particularly preferred embodiment there is, however, provision that, in order to initiate the emergency braking mode and/or the emergency stop mode, the drive controller 5 actuates the drive motor 3 in such a way that said drive motor 3 acts in a braking fashion on adjustment of the closure element 1. The fact that additional structural measures, such as the provision of a brake arrangement, can be dispensed with is advantageous here.
The weight of the tailgate 1 can be of a considerable magnitude so that preferably a spring arrangement 6 is provided which at any rate compensates the weight of the tailgate 1 over an adjustment range of the tailgate 1. This is generally intended to ensure that the tailgate 1 is always located in the vicinity of a state of equilibrium. However, it may also be advantageous to provide over-compensation in such a way that the tailgate 1 is predisclosed to move in the opening direction. The spring arrangement 6 preferably brings about the already abovementioned prestressing of the drive 2 in the opening direction here. However, it is also conceivable that a spring arrangement is provided separately from the drive 2. This generally comprises gas compression springs or the like.
In the case of a spring fracture, the potential fault state of the undesired slamming shut of the tailgate 1 is associated with all spring arrangements which counteract the weight of the tailgate 1.
It is basically conceivable that, in order to initiate the emergency operating mode and/or the emergency stop mode, the braking of the drive motor 3 takes place in an uncontrolled fashion. However, the braking drive motor 3 preferably takes place in a controlled fashion.
The drive controller 5 preferably has a control loop 7 for controlling the motor-operated adjustment of the closure element 1, wherein the control loop 7 generates a manipulated variable 9 in the motor-operated adjustment mode on the basis of a control error, and wherein the drive motor 3 acts in a controlled driving fashion or controlled braking fashion as a function of the manipulated variable 9. “controlled driving fashion” and “controlled braking fashion” preferably mean here that the braking effect is not only switched on and off but is also “metered”, as is the driving effect of the drive motor 3. Preferred variants of such metered “braking” will be explained below.
The above control loop 7 is illustrated by way of example in
During the equipment of the drive controller 5 with a control loop 7, the above fault state can be detected particularly easily. Such detection is then based on the detection of a sudden control error, caused, for example, by the mechanical rupture of a spring arrangement 6 which is assigned to the drive 2.
One particularly simple possible way of implementing the above braking effect of the drive motor 3 is also shown in
The variant of short-circuit braking illustrated in
In the embodiment which is illustrated in
Numerous variants are conceivable for the circuitry implementation of the bidirectional actuation on the one hand and the short-circuit braking on the other. The switching unit 17 can, for example, be configured as a relay. However, it is also possible for the bidirectional actuation to the preferably implemented as a full bridge in an integrated component, and for the short-circuit braking to be implemented in a separate relay.
The explained braking effect of the drive motor by short circuiting is based, as mentioned above, on the Lorentz principle. However, this means that this cannot be used to implement braking as far the stationary state in the case of continuous loading of the tailgate 1, for example by weight.
Alternatively or additionally there is therefore preferably provision that, in order to generate a braking effect, the drive controller 5 applies a countervoltage and/or a countercurrent to the drive motor 3 which countervoltage and/or countercurrent counteracts the respective adjustment movement. This can be readily implemented with the power output stage 15 illustrated in
Depending on the embodiment of the closure element 1, the emergency stop mode is associated with a continuous power drain by the drive motor 3. This is the case with the tailgate 1 which is illustrated in
During the controlled stopping of the tailgate 1 above, the tailgate 1 is continuously braked and driven. The braking is carried out here by means of the abovementioned application of a countervoltage and/or a countercurrent to the drive motor 3. It goes without saying that the short-circuit braking above does not permit the tailgate 1 to be returned from deflected position into the stop position.
The utilization of the braking effect of a drive motor 3 according to the proposal can be freely applied to all possible structural variants. One particularly preferred drive 2 is illustrated in
It has already been pointed out that the teaching according to the proposal can be applied to all types of closure elements 1 in a motor vehicle. However, the closure element 1 is preferably configured as a flap, in particular as a tailgate 1 or as a trunk lid.
According to a further teaching, which is also attributed independent significance, a closure element arrangement, in particular a tailgate arrangement, in a motor vehicle is claimed which has a closure element and a drive arrangement, as explained above. Reference can be made to the full scope of the above statements.
Number | Date | Country | Kind |
---|---|---|---|
10 2008 057 014.1 | Nov 2008 | DE | national |
This application is a national stage application under 35 U.S.C. 371 of International Patent Application Serial No. PCT/EP2009/007222, entitled “ DRIVE ARRANGEMENT FOR MOTOR-OPERATED ADJUSTMENT OF A CLOSURE ELEMENT IN A MOTOR VEHICLE,” filed Oct. 8, 2009, which claims priority from German Patent Application No. 10 2008 057 014.1, filed Nov. 12, 2008, the disclosures of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2009/007222 | 10/8/2009 | WO | 00 | 7/25/2011 |