DE102007001068B4 - Damper drive for motor vehicles in particular - Google Patents

Abstract

Damper drive for in particular motor vehicles, with at least one drive unit (5, 6, 7), which acts on a flap (1) and a controllably switched on and off electric motor (5), wherein the electric motor (5) with a varying electric drive power (P ), characterized in that - the electrical drive power (P) is varied as a function of a) the position of the flap (1) and / or b) forces acting on the motor vehicle, wherein - at least one sensor (23, 24) is realized for detecting the position of the flap (1) and / or acting on the motor vehicle forces.

Description

The invention relates to a damper drive for particular motor vehicles, with at least one drive unit which acts on a flap and a controllable switched on and off electric motor, wherein the electric motor is subjected to a varying electric drive power, and a method for operating such a damper drive.

A damper drive is exemplified in the DE 38 16 175 A1 described. There, a first drive wheel for generating a sliding movement and a second drive wheel for generating a pivoting movement are realized. Both drive wheels can be coupled via automatically controllable clutches with a common drive motor or electric motor. That is, the controllable switched on and off electric motor requires in the known teaching additional mechanical clutches. This is expensive and expensive.

In the context of the generic state of the art according to the DE 10 2004 052 590 A1 a device for opening and / or closing a pivotable body part and in particular a tailgate of a motor vehicle is described. The electromotive drive provided at this point is provided with an electronic disconnecting device. The enabling device can be activated as a function of a signal of a sensor device. With the aid of the sensor device, a manual actuation of the pivotable body part or the flap is detected. As a result, the electric motor drive can be released in a manual intervention, so that a motor shaft is substantially freely rotatable. As a result of the electromotive drive, no forces counteracting the manual actuation are exerted on the pivotable body part or flap.

In the context of the well and generally generic state of the art after the DE 20 2005 011 236 U1 it is about a control device of an adjustment of a motor vehicle. The adjusting device may also be a tailgate. For controlling an electrical quantity of the drive motor and in particular of the drive current, at least one power semiconductor is provided whose actual temperature is approximately determined. As a result, any blockage can be determined.

In practice, attempts to produce such damper actuators as small as possible and little bulky, because the installation space for such damper actuators is increasingly reduced by additional inputs and attachments. In addition, the cost pressure in the automotive industry is enormous, so that low-cost and cost-effective solutions are sought. This is where the invention starts.

The invention is based on the technical problem of further developing such a flap drive so that an overall cost-effective and compact solution is made available. In addition, the possibility should be opened to be able to brake the flap in question easily in virtually any desired position, as well as to specify a corresponding method for operating such a flap drive.

This problem is solved by the features specified in claims 1 and 7.

The electrical drive power can basically be changed in terms of their amplitude. It will usually work with a voltage change, whereas the current remains the same. In the context of the invention, however, it is advantageous to work with a time-varying drive power. This means that the current and voltage are kept predominantly constant, but the entire drive power is switched on and off as such. That is, the drive power may be pulsed. Advantageously, the drive power in the pause times between individual drive pulses will not be completely reduced to zero in order, for example, to avoid falling back of an openable tailgate as a result of its own weight and to achieve as continuous and "smooth" a movement as possible.

In order to achieve the temporal modulation of the electric drive power, it is possible, for example, to work with the aid of pulse width modulation (PWM). This pulse width modulation expresses that the length of the respective drive pulse is varied according to the requirements. The same applies to the pause times between the individual drive pulses, which can also be varied.

The drive unit in question is usually used in a tailgate drive, as used for example in the DE 20 2006 006 792 U1 will be described in detail. In this context, the drive unit in addition to the acted upon by the varying electric drive power electric motor in addition to a spindle drive, a crank mechanism or a hydraulic unit. The electric motor works on the spindle drive, the crank mechanism or the hydraulic unit in such a way that its rotational movements are usually implemented in pivotal movements of the flap.

For this purpose, the flap is usually pivotally attached to a body of the Motor vehicle articulated. The drive unit may have on the one hand a fixed connection element and on the other hand a (regularly linear) displaceable connection element. The fixed connection element is largely connected to the body, whereas the displaceable connection element acts on the pivotable flap and thereby initiates the pivoting movements of the flap.

The flap is not limited to a tailgate of the said motor vehicle. In principle, namely, a pivotable side door can be driven with a corresponding damper drive. In addition, the damper drive regularly ensures that said flap or tailgate is opened and closed. That is, the damper drive performs the motor opening and closing of the flap in question. In order to provide a compact and at the same time cost-effective design, the drive unit regularly has a spindle drive in addition to the electric motor. Here, the electric motor sets a spindle in rotation. Moves on the spindle are a spindle nut up and down, which is connected to the adjustable or movable or movable connection element, which consequently performs the necessary linear positioning movements.

The electrical drive power for acting on the electric motor is variable depending on the position of the flap compared to the motor vehicle or the vehicle body. In fact, the invention thereby takes into account the requirement to be able to decelerate the flap or tailgate theoretically in any position.

Incidentally, it is conceivable to reduce the electric drive power for the electric motor, for example, when the flap is close to its closed position. Because in this position, the flap is usually moved by its own weight. This ensures that the flap or tailgate during the closing movement gently into the associated door lock falls. That is, the electric drive power for acting on the electric motor can not be adjusted or varied not only in such a way that the flap is braked for a certain time compared to the motor vehicle. But also in such a way that the opening movement and / or closing movement of the flap with variable drive power of the electric motor is completed. In this case, the invention takes into account the fact that for the movements in question not always a constant electric drive power of the electric motor is needed because complementary effects play a role that have not been considered so far. Thus, when closing the flap their own weight support the closing movement. Similarly, a spring can act at this point.

Just as well, it is conceivable that the opening position of the flap is supported by a spring, which allows a reduction in the electric drive power of the electric motor. In any case, the electric drive power can be variably adapted to the position of the flap and possibly also its closing and / or opening speed.

To achieve this in detail, the one or more sensors are realized. It is conceivable here to work on the flap in question with angle sensors which detect the respective pivoting angle and consequently the position of the flap. In addition, changes in the swing angle, the opening speed / closing speed of the flap can be determined. Alternatively or additionally, it is conceivable to work with sensors that are usually integrated into the electric motor. Here Hall sensors have proven that detect the speed (and also the direction of rotation) of the electric motor and with their help not only the position of the flap, but also their opening / closing speed can be calculated.

Finally, the use of one or more force sensors for determining the weight is conceivable. Such a force sensor can be mounted, for example, in the region of the fixed connection element and registers the forces or weight forces exerted on the fixed connection element by the flap. Depending on the weight forces can now be applied to the electric motor with the variable electric drive power. In this case, one will tend to work with a greater electrical drive power, the greater the force exerted by the fixed connection element on the body forces.

Alternatively or additionally, the electrical drive power is also varied as a function of forces acting on the motor vehicle. These forces may be static or dynamic forces. In the former case, it is conceivable that the motor vehicle is parked on a slope or downhill slope and in dependence on these acting on the motor vehicle as a whole forces and the electrical drive power for the electric motor is varied. Thus, for example, the closing force exerted by the electric motor on the flap closing force can be reduced when the motor vehicle is parked on a downgrade and thereby undergoes the closing movement of the flap or tailgate support. Conversely, the closing force must be increased compared to the situation in a plane when the motor vehicle at a Slope route is turned off. The same applies to a possible deceleration force to slow down the flap or tailgate feeling. In any case, it is clear that the electric drive power is also varied depending on the total acting on the motor vehicle from the outside forces.

To quantify these forces, additional sensors can be queried or existing sensors can be evaluated anyway. For example, it is conceivable to detect the inclination of the motor vehicle with the aid of an acceleration sensor, which is usually present anyway, for example, to trigger safety devices such as an airbag. Overall, these sensors, whether they are now assigned to the electric motor directly or the motor vehicle in general, ensure that the signals emitted by them - for example, via a control unit - specify the electric drive power for the electric motor by the drive power is pulse width modulated according to an advantageous embodiment.

To achieve this in detail, the electric motor is switched off in a pulse width modulation in the pause times without power or preferably almost de-energized. In contrast, the drive pulses ensure that the electric motor performs the desired rotation in the given drive direction during its duration. In this context, the electric motor may be formed reversible, so be additionally changed in terms of its direction of rotation. This makes it easy to distinguish between the already mentioned opening movement and the closing movement of the flap.

In general, the control unit ensures that with their help, the electrical drive power is changed. For this purpose, the control unit acts on at least one switching device. The switching device may in each case be a conventional controllable switch, for example a relay. Preferably, however, a low-cost electronic switch, for example a FET (field effect transistor) and here in particular a MOS (metal to silicon) FET is used. Of course, combinations of, for example, relay and transistor are conceivable.

In addition, the electric drive power for varying the application of the electric motor can be switched off completely. In most cases, one will additionally operate the electric motor in the sense of a generator in this case, in order to represent the closing movement of an, for example, connected tailgate. As a result, an overall harmonious course of the flap movement is achieved.

On the one hand, the electric motor no longer receives any electric drive power during the closing movement of the flap, which is primarily used for the opening movement. On the other hand, as it were switching the electric motor in a generator mode or generator mode ensures that kinetic energy of the tailgate is converted into those of the electric motor and finally into electricity. This current can be dissipated through a resistor and converted into heat, so overall leads to the desired deceleration. The effect is naturally greater than if the electric motor in question, for example, "only" disengaged or de-energized. Because by its generator function of the electric motor takes in the desired manner kinetic energy during the closing movement and transforms them, for example, in heat.

On the above-mentioned function of the electric motor in the sense of a generator, which as it were inherent from the outset, is usually used only when the associated motor vehicle is parked in the plane on a sloping or slightly ascending road and here closed the tailgate shall be. If, on the other hand, the motor vehicle is on a pronounced incline, situations are entirely conceivable that the electric motor is continuously supplied with electrical drive power both for the opening movement and for the closing movement, because otherwise the associated tailgate could not be closed at all in the example. Conversely, it is quite conceivable during operation of the tailgate on a downgrade that the opening movement is at least partially implemented so that the electric drive power is switched off and the electric motor is operated in the sense of a generator to decelerate the supported by the weight of the flap opening movement. In any case, the invention holds the appropriate variant available. This also includes that, for example, between not done drive and generator operation of the electric motor and drive the electric motor is selectively switched back and forth or can be.

Always a damper actuator is provided, which provides a universal, compact and inexpensive solution for controlling the position of a flap, especially tailgate available. In addition, there is still the possibility to actuate the flap or tailgate supplementarily or alternatively manually, because the electric motor can be operated with switched-off drive power in the sense of a generator.

Since each required for this variable electric drive power using a cost-effective electronic circuit without mechanical intervention is realized, a compact and inexpensive solution is provided. In addition, the position or position of the motor vehicle and the flap are taken into account when it comes to adjust the electric drive power for the electric motor accordingly and to initiate the desired movement process (opening or closing). As a result, a significant increase in comfort is observed because, for example, the closing process is only accompanied by the electric motor and the weight of the flap mainly contributes to this. In addition, a particularly harmonious course of the flap movement results. As a consequence, the noise during the closing process is additionally reduced and at this point the obligatory rear lock is less mechanically stressed. Here are the main benefits.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment; show it:

1 a motor vehicle with a tailgate in an overview,

2a and 2 B the associated drive unit for moving the flap or tailgate schematically,

3 an electronic circuit for controlling the electric motor of the drive unit schematically and

4 the variant actually used 3 ,

In the 1 a flap on a motor vehicle is shown, namely a motor vehicle flap, which is not limited to a motor vehicle pivoting flap in the form of a tailgate 1 is. The tailgate 1 is in the range of a pivot axis 2 to an associated vehicle body 3 pivotally hinged and serves to an associated body opening 4 to close and release. For this purpose, the motor vehicle flap or tailgate 1 in the context of the embodiment and not restrictive motor moves, namely by resorting to a tailgate 1 acting drive unit 5 . 6 . 7 ,

The drive unit 5 . 6 . 7 is made up of an electric motor 5 and a spindle drive 6 . 7 together. The in the 2a and 2 B Spindle drive shown in detail 6 . 7 essentially has a spindle 6 as well as one on the spindle 6 up and down moving spindle nut 7 on. By the electric motor 5 in turns, he ensures that even the spindle 6 rotates and consequently the spindle nut 7 moved up and down.

End of the drive unit 5 . 6 . 7 find a solid connection element 8th and a movable connecting element 9 , The fixed connection element 8th is to the vehicle body 3 connected, whereas the displaceable or movable connection element 9 the flap 1 applied, or vice versa. For this purpose, the movable connection element 9 in the example with the spindle nut 7 connected like this 2a and 2 B represent in detail drawing.

The to the drive unit 5 . 6 . 7 associated electric motor 5 can be controllably switched on and off. For this purpose, the electric motor 5 acted upon by a varying electric drive power P. In the example, the motor voltage U is changed. In the context of the embodiment and not restricting it is worked with a constant electric drive power P, which is switched on and off within certain time intervals, as shown in the schematic timing diagram in the 2a and 2 B makes it clear. In fact, the drive power P and consequently the motor voltage in individual pause times t ₁ , t ₂ , t ₃ between drive pulses P ₁ , P ₂ , P _{3 is} not reduced completely to zero, but to a predetermined constant minimum value.

It can be seen that the electric drive power P is pulse width modulated by the electric motor 5 with the drive pulses P ₁ , P ₂ , P ₃ different duration t is applied. Between these drive pulses P ₁ , P ₂ , P _3, there is consequently the likewise variable pause times t ₁ , t ₂ and t ₃ . In order to be able to vary the drive pulses P ₁ , P ₂ , P ₃ and the pause times t ₁ , t ₂ , t ₃ , is a control unit 10 realized in the 3 and 4 recognizes and which via control lines 11 . 12 . 17 . 18 ensures that the electric drive power P for the electric motor 5 has the desired modulation. In fact, in the embodiment, the electric drive power P for the electric motor 5 temporally changed, namely pulsed, in the sense of a pulse width modulation. Of course, this is not meant to be limiting.

In detail, this is the electric drive power P using the control unit 10 changed, which in the embodiment of two switching devices 13 . 14 applied. In addition to these two switching devices 13 . 14 There are two more switching devices 15 . 16 realized, which serve the direction of rotation of the electric motor 5 to specify or to reverse the direction if desired. At the switching devices 13 to 16 are basically controllable switch whose respective switching state (open or closed) from the control unit 10 is given. These are the already mentioned four control lines 11 . 12 . 17 . 18 realized. As part of the variant 4 are the switching devices 13 to 16 designed as FET transistors, in the present case as MOS-FETs, which are each operated in source circuit. With the help of the control lines 11 . 12 . 17 . 18 changes the control unit 10 the respective gain-source voltage and opens and thereby closes the associated "switch".

Finally, you recognize two poles 19 . 20 a vehicle battery or a voltage source, wherein the positive pole with 19 and the negative pole or ground pole with 20 Marked are. The basic mode of operation is now based on the schema representation in 3 explained.

So that the electric motor 5 works in one direction, for example, the two switching devices 14 and 15 closed. This is ensured by the control unit 10 , As a result, the current flows in the 3 above indicated direction from left to right by the electric motor 5 and generated in this way on the output side a rotational movement, with the help of the spindle drive 6 . 7 in a movement of the tailgate 1 empties.

For reversing the direction of rotation it is only necessary to use the two aforementioned switching devices 14 . 15 to open and in contrast the switching devices 13 and 16 close. Then the current flows from the positive pole 19 from right to left by the electric motor 5 like the bottom arrow in 3 indicates, so that the rotation reverses. This allows the different directions of movement of the flap or tailgate 1 and as a result realize the opening and closing movement.

In order now to the electric drive power P for the electric motor 5 to vary and thus also to slow down its output-side movement or the electric motor 5 To stop completely, the electric drive power P by means of the control unit 10 changed. For this purpose, the switching devices 14 . 15 for the one direction of movement or 13 . 16 for the other direction of movement in time from the control unit 10 predetermined pulse width modulation open and closed. In this case, the two switching devices 14 . 15 on the one hand and 13 . 16 On the other hand, both together open and closed together or even only one switching device of the pair. In any case, the drive power P can be set and changed as shown in the diagram in the 2a . 2 B is pictured.

As a result, the output side movement of the electric motor 5 slowed or accelerated, in the direction of movement desired. Another variant is added with the possibility, with switched off drive power P, the braking effect of the electric motor 5 in addition to exploit. One recognizes by means of the 3 that is a supply line 21 . 22 for the electric motor 5 in front of his entrance into an entrance pipe 21a . 22a and a short circuit line 21b . 22b Splits. In the short circuit lines 21b . 22b are the switching devices 13 . 14 looped.

In order now to the complementary decelerating effect of the electric motor 5 when the drive power P is switched off, the electric motor 5 operated in the sense of a generator. This is the electric motor 5 over the short circuit lines 21b . 22b with the help of the switching devices 13 . 14 shorted. In this functional state, of course, both switching devices 15 . 16 open. This is ensured by the control unit 10 , In this working position, the former acting as a drive electric motor 5 work like a generator, namely by the tailgate 1 induces tension in it. The thus of the working as a generator electric motor 5 provided electric power can be converted into heat, for example via a switchable resistor and leads to the overall movement of the tailgate 1 is actively decelerated when the drive power P is switched off. This is the described generator function of the electric motor 5 as a further variant in addition to the variation of the electric drive power P for the electric motor 5 and, of course, the change of its direction of rotation available to a total smooth and harmonic movement of the flap 1 to realize.

In this case, the electric drive power P for the electric motor can be 5 depending on the position of the flap or tailgate 1 in comparison to the motor vehicle or the vehicle body 3 specify variable. For this purpose, the tailgate 1 a merely indicated angle sensor 23 assigned, in the context of the embodiment in the pivot axis 2 may be arranged. Alternatively, but also the speed and direction of rotation of the electric motor 5 with a query in this integrated sensor. In any case, the signal of the sensor or angle sensor 23 from the control unit 10 processed.

Also to the control unit 10 connected is another sensor 24 which is present and not limiting as inclination sensor 24 is formed and inclinations of the vehicle body 3 detected. As described in the introduction, can be with the help of the sensors 23 . 24 certain operating conditions of the vehicle body 2 or of the motor vehicle as a whole and / or its flap or tailgate 1 to capture. Depending on the hereby determined and on the motor vehicle or the vehicle body 3 acting forces and / or the position of the flap 1 and / or their closing speed / opening speed can now be the electric drive power P for the electric motor 5 vary.

For this purpose, the control unit calculates 10 from the position of the tailgate 1 or the position of the vehicle body 3 an associated electric drive power P, with which the electric motor 5 is charged. Depending on the desired result and the selected direction of rotation for the electric motor 5 becomes the corresponding switching device 13 or 14 with the help of the associated control line 11 respectively 12 in the cycle of the calculated pulse width modulation open and closed. As a result, the electric motor experiences 5 the in the 2 schematically represented modulated loading. It can - as I said - the drive pulses P ₁ , P ₂ , P ₃ as well as the pause times t ₁ , t ₂ , t ₃ depending on the position of the flap 1 on the vehicle body 3 acting forces and / or depending on the closing / opening speed of the flap 1 be changed.

Claims (7)

Damper drive for in particular motor vehicles, with at least one drive unit ( 5 . 6 . 7 ), which has a flap ( 1 ) and a controllable switched on and off electric motor ( 5 ), wherein the electric motor ( 5 ) is acted upon by a varying electrical drive power (P), characterized in that - the electrical drive power (P) in dependence on a) the position of the flap ( 1 ) and / or b) forces acting on the motor vehicle, wherein - at least one sensor ( 23 . 24 ) for detecting the position of the flap ( 1 ) and / or realized by acting on the motor vehicle forces. Flap drive according to claim 1, characterized in that the electrical drive power (P) is changed over time, for example pulsed, is formed. Flap drive according to claim 1 or 2, characterized in that the electrical drive power (P) respectively switched off and the electric motor ( 5 ) is operated in the sense of a generator. Flap drive according to one of claims 1 to 3, characterized in that the electrical drive power (P) by means of a control unit ( 10 ), which at least one switching device ( 13 to 16 ). Flap drive according to one of claims 1 to 4, characterized in that a supply line ( 21 . 22 ) for the electric motor ( 5 ) in an input line ( 21a . 22a ) and a short-circuit line ( 21b . 22b ) Splits. Flap drive according to one of claims 1 to 5, characterized in that the electric motor ( 5 ) is reversibly formed and in each case two divided supply lines ( 21 . 22 ) are provided. Method for operating a flap drive for motor vehicles, in particular, after which a flap ( 1 ) by means of a drive unit ( 5 . 6 . 7 ) is applied, after which further the drive unit ( 5 . 6 . 7 ) a controllable switched on and off electric motor ( 5 ), and after which the electric motor ( 5 ) is acted upon electrical drive power (P), characterized in that - the electrical drive power (P) in dependence on a) the position of the flap ( 1 ) and / or b) forces acting on the motor vehicle, wherein - with the aid of at least one sensor ( 23 . 24 ) the position of the flap ( 1 ) and / or forces acting on the motor vehicle are detected.

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