DE102021129269A1 - Drive arrangement for motorized adjustment of a flap of a motor vehicle - Google Patents

Abstract

The invention relates to a drive arrangement for motorized adjustment of a flap (2) of a motor vehicle (3), the drive arrangement (1) being equipped with a drive (4) which has an electric drive motor (5) and a drive motor (5) which is connected downstream in terms of drive technology feed gear (6) for generating linear drive movements, the drive (4) being equipped with a brake arrangement (7) which can be engaged/disengaged via a freewheel arrangement, the drive arrangement (1) having a control arrangement (8) which controls the drive (4th ) in order to adjust the flap (2) in an adjustment range for the flap position, and wherein the control arrangement (8) determines drive values of the drive arrangement (1) that are representative of a flap movement. It is proposed that the control arrangement (8) monitors the drive values to ensure that a predetermined braking error criterion is met when the flap (2) reaches a predetermined holding state, and that the control arrangement (8) provides a braking routine during motorized adjustment when the braking error criterion is met, in which the control arrangement (8) controls the drive (4) in such a way that the drive arrangement (1) works with a motor braking effect on the flap (2).

Description

The present invention relates to a drive arrangement for motorized adjustment of a flap of a motor vehicle according to the preamble of claim 1.

The drive arrangement in question is used for motorized adjustment of a flap of a motor vehicle, which is, for example, a tailgate, a trunk lid, a side door, a tailgate, a hood or the like. The flap can be pivoted and/or slidably arranged on the motor vehicle body.

The well-known drive arrangement ( WO 2009/059747 A1 ), on which the invention is based, is equipped with a brake arrangement which can be engaged/disengaged via a freewheel arrangement and which is connected on the drive side to a motor and on the output side to the flap. The freewheel assembly engages the brake assembly when the flap is adjusted, thereby initiating a driven-side motion in the freewheel assembly. As a result, for example, the brake arrangement can counteract the dead weight of the flap, so that the flap can be held securely, in particular in a holding flap position. In the case of a drive-side movement, on the other hand, the brake arrangement is disengaged, as a result of which the braking force does not oppose the drive during the adjustment. This proven state of the art makes it possible to realize large differences between the braking effect, which opposes a movement introduced on the drive side, and the braking effect, which opposes a movement on the output side.

It is a challenge to improve the known prior art with regard to error detection. The clutch of the brake assembly, which is effected, for example, via a wrap spring arrangement, can be subject to wear or, in the event of a failure of individual components, in particular the wrap spring arrangement, can in many cases no longer engage and disengage properly, which affects the operation of the drive arrangement.

The invention is based on the problem of designing and developing the known drive arrangement in such a way that further optimization is achieved with regard to the challenge mentioned.

The above problem is solved by the features of the characterizing part of claim 1.

The fundamental consideration is that if the brake arrangement no longer fully engages during a movement on the output side and therefore too little braking force is exerted in this situation, the control arrangement can detect this on the basis of drive values once the flap has reached a holding state. For example, the flap then leaves a previously assumed flap position too quickly when the brake arrangement is not fully engaged.

In detail, it is proposed that the control arrangement monitors the drive values for fulfillment of a predetermined braking error criterion when a predetermined holding state of the flap is reached, and that the control arrangement provides a braking routine during motorized adjustment when the braking error criterion is met, in which the control arrangement controls the drive in such a way that the drive arrangement works with a motorized braking effect on the flap.

The brake arrangement can also be highly relevant to safety in the event of pinching or a collision, the presence of which is monitored using the drive values. If the brake assembly fails, the driving forces could otherwise be too high, since the brake assembly counteracts the drive only insufficiently. In the preferred embodiment according to claim 2, the check of the braking error criterion is used accordingly to change the pinching or collision criterion, if necessary, with a limit value of the drive value preferably being reduced to increase safety.

In the preferred embodiment according to claim 3, the braking error criterion is defined by a movement limit value which, in particular, indicates that a flap speed or flap acceleration to be expected for the respective flap has been exceeded. Preferably, however, when checking the braking error criterion, it is taken into account whether the flap movement is caused by manual actuation by the operator, which is represented by an actuation criterion.

Furthermore, the braking error criterion according to claim 4 can be specified as a function of the flap position. The flap arrangement preferably has a self-retaining area in which it is provided that the flap automatically maintains the respective flap position. The braking error criterion can be defined differently within the self-locking range than outside of the self-locking range.

The fact that the flap automatically leaves the self-holding area can also be used to define the braking error criterion, which is specified in claim 5 . Leaves the If a flap position in the self-retaining range occurs, for example, with a flap speed that is too high, this is an indication of incomplete disengagement of the brake assembly.

• 1 das Heck eines Kraftfahrzeugs in einer Seitenansicht mit einer vorschlagsgemäßen Antriebsanordnung sowie einen Antrieb der Antriebsanordnung in einem Längsschnitt.

The invention is explained in more detail below with reference to a drawing that merely shows exemplary embodiments. In the drawing shows

• 1 the rear of a motor vehicle in a side view with a proposed drive assembly and a drive of the drive assembly in a longitudinal section.

The exemplary embodiment shown in the figures and preferred in this respect relates to a drive arrangement 1 for motorized adjustment of a flap 2 of a motor vehicle 3, the drive arrangement 1 being equipped with a drive 4 which has an electric drive motor 5 and a feed gear 6 downstream of the drive motor 5 in terms of drive technology for generating has linear drive movements, the drive 4 being equipped with a brake arrangement 7 which can be engaged/disengaged via a freewheel arrangement, the drive arrangement 1 having a control arrangement 8 which controls the drive 4 in order to adjust the flap 2 in an adjustment range for the flap position, and wherein the control arrangement 8 determines drive values of the drive arrangement 1 which are representative of a flap movement.

Here, and preferably, the flap 2 is a tailgate of the motor vehicle 3, which is mounted pivotably about a flap axis 9 and can be pivoted in the region of a flap opening 10. However, the proposed solution can also be applied to all other flaps 2 mentioned in the introductory part of the description. All statements relating to the illustrated flap 2 designed as a tailgate apply accordingly to all other types of flaps 2 .

In a preferred embodiment, two drives 4 are provided, which are arranged on both sides of the flap opening 10 assigned to the flap 2 . In the following, only a single drive 4 is discussed for the purposes of a simplified representation. All statements in this regard apply correspondingly to any further drive 4 that may be provided.

As shown in the illustration in 1 further shows, drive connections 11 of the drive 4 are provided, between which the linear drive movements can be generated. In the preferred embodiment shown, the feed gear 6 is designed as a spindle/spindle nut gear, with the drive connections 11 being assigned to the spindle 12 and the spindle nut 13 in each case. Furthermore, an intermediate gear 14 can be provided, which is connected in drive terms between the drive motor 5 and the feed gear 6 .

In terms of drive technology, this means that motor movements of the drive motor 5 can be transmitted to the flap 2 by the relevant components. In the assembled state, the drive 4 is coupled in motion to the flap 2 via one of the drive connections 11 . The drive motor 5 is preferably bidirectionally coupled to the flap 2 for movement. The movement coupling allows the flap 2 to be motor-driven by means of the drive 4 between an in 1 shown open position and a closed position, not shown, to be adjusted by motor in both directions of movement. At the same time, this movement coupling also works the other way around. For this purpose, the drive 4 is designed to be driven back. This means that the initiation of a movement in the flap 2 leads to at least part of the drive train between the drive motor 5 and the flap 2 being driven back.

The brake assembly 7 has a braking element, not shown in detail, which generates a braking effect with which the braking element brakes a movement initiated on the output side. The braking effect is generally brought about by a braking load, which can be a braking force or a braking torque, which can in principle be generated as desired. The braking effect ensures that a movement initiated on the output side, ie a movement initiated via one of the drive connections 11, is slowed down or prevented, depending on the strength of the movement. The braking effect is particularly preferably generated by a frictional torque or a frictional force, meaning static or rolling and/or sliding friction, depending on the state.

The freewheel arrangement engages the braking element by the movement introduced on the output side and disengages the braking element by a movement introduced on the input side. The movements introduced into the drive arrangement 1 are conducted here and preferably through the freewheel arrangement, but it is also sufficient if they are only partially conducted into the freewheel arrangement, for example, as long as the engagement and disengagement can be realized thereby. The engagement and disengagement can, for example, in a manner known per se, such as in the WO 2009/059747 A1 described, be effected via a wrap spring arrangement.

As shown, the control arrangement 8 can be configured as a flap control device which is assigned to the flap 2 and which interacts with a higher-level motor vehicle control system. Instead of the With this decentralized approach, the control arrangement 8 can also be part of a central motor vehicle control system. The control arrangement 8 preferably has control electronics for implementing the control tasks occurring here.

The drive value can be an electrical variable, for example the drive voltage provided and/or generated at the electric drive motor 5 or the drive current, which occurs during operation of the drive arrangement 1 and allows conclusions to be drawn about the drive movements and thus flap movements. For example, the drive movement can be inferred on the basis of current ripples in the drive current.

It is also conceivable that the drive values are sensor values of a movement sensor arrangement provided for the direct or indirect detection of the flap movement. The movement sensor arrangement can be assigned to the drive arrangement 1 and, for example, to the drive motor 5 or feed gear 6 . It is also possible that the movement sensor arrangement is not part of the drive arrangement 1 but is assigned to the flap 2 and the control arrangement 8 only receives the sensor values of the movement sensor arrangement in order to determine the drive values.

It is now essential that the control arrangement 8 monitors the drive values to ensure that a predetermined braking error criterion is met when a predetermined holding state of the flap 2 is reached, and that the control arrangement 8 provides a braking routine during motorized adjustment when the braking error criterion is met, in which the control arrangement 8 controls the drive 4 in this way that the drive assembly 1 works with a motor braking effect on the flap 2.

The holding state is preferably understood to mean a state of movement of the flap 2 close to or at a complete standstill of the flap 2 . For example, the holding state is considered to have been reached when the speed of the flap 2 determined from the movement values falls below a predetermined threshold value. It can also be specified that a specified adjustment range or a specified flap position must be reached in order to reach the holding state. The holding state can also be considered to have been reached when activation of the drive 4 for the motorized adjustment of the flap 2 has been completed, in particular regardless of which state of motion the flap 2 assumes. In the holding state, preferably no driving forces caused by the drive motor 5 act.

The brake error criterion is representative of the fact that the engagement of the brake arrangement 7 does not take place completely and therefore no braking effect or at least an insufficient braking effect is generated by the brake arrangement 7 even in the case of a movement initiated on the output side.

The braking effect of the brake arrangement 7 is therefore motor-assisted by the actuation in the braking routine, for example in order to absorb the weight force and inertial forces acting on the flap 2 . The motor braking effect can be implemented by operating the drive motor 5 as a short-circuit brake or by providing drive power that counteracts the movement of the flap.

It is conceivable that in a normal operational state no motorized braking effect is provided and the braking routine is activated when the braking error criterion is met during motorized adjustment. An already existing activation in the braking routine, in particular with regard to an increased motor braking effect, can also be modified if the braking error criterion is met.

The control arrangement 8 can also carry out a holding routine in a predetermined holding flap position, in which the control arrangement 8 controls the drive 4 in such a way that the drive arrangement 1 works with a motor braking effect on the flap 2 . In the holding flap position, the flap 2 is automatically stopped, whereby the flap 2 should remain in the respective flap position even without activation of the drive 4 due to a mechanical equilibrium of forces. When the mechanical braking effect decreases, there is a risk that the flap 2 will no longer remain in the holding flap position by itself. The control arrangement 8 can, for example, regulate the drive 4 to the holding flap position in a holding control circuit and thus stabilize the holding flap position by motor.

Furthermore, it is preferably provided here that the control arrangement 8 monitors the drive values during motorized adjustment of the flap 2 to ensure that a trapping criterion and/or collision criterion of the flap 2 is met, and that the control arrangement 8 modifies the trapping criterion and/or the collision criterion to meet the braking error criterion. preferably that the control arrangement 8 reduces a limit value of the pinching criterion and/or collision criterion for the drive value.

The pinching criterion is representative of the fact that an object in the flap opening 10 between rule flap 2 and motor vehicle body is detected by a closing movement of the flap 2. The collision criterion is representative of the fact that the flap 2 makes contact with an object outside of the motor vehicle 3, in particular during an opening movement. Both cases can be detected using the drive values occurring during motorized adjustment, for example via limit values of the drive current or a deviation from a specification of the flap speed, whereupon the motorized adjustment is modified and in particular terminated or reversed. However, the definition of the pinching criterion and/or the collision criterion is also based on a specific assumption about the mechanical braking effect, which can be modified here if the braking error criterion is met.

In particular, when the mechanical braking effect decreases, a reduction in limit values for the drive value is advantageous, since otherwise excessive drive forces can act on the object.

Furthermore, it is preferably provided here that the braking error criterion is specified on the basis of a movement limit value of the drive values being exceeded in the holding state, preferably that the movement limit value relates to a maximum flap speed and/or flap acceleration, more preferably that the braking error criterion is only given if a specified, a manual actuation action on the flap 2 representing an actuation criterion is considered to be fulfilled by the drive values.

Manual actuation by the operator is recognized via the actuation criterion, for example if the flap 2 is manually closed or opened by the operator. If the actuation criterion is met, the flap movement determined via the drive values is therefore not attributed to a faulty brake arrangement 7, but to the operator.

It is also preferably provided here that the braking error criterion is specified as a function of the flap position, preferably that a self-retaining range of the flap position in the adjustment range is specified for the drive arrangement 1, and that the braking error criterion is defined differently within the self-retaining range than outside of the self-retaining range.

The forces acting on the flap 2 can vary with the flap position. In the case of a pivotable flap 2 in particular, the weight and the driving force act on the flap 2 at different angles depending on the flap angle. A failure of the brake arrangement 7 can consequently lead to different effects on the flap 2 depending on the flap position. The braking error criterion is specified in particular as a mathematical function of the flap position, in particular the flap angle, in order to take this fact into account.

The holding flap positions already mentioned are provided in the self-holding area. In configurations, however, the self-retaining range can only extend over part of the adjustment range, which means that flap positions are provided in which a weight-related lowering movement or spring-related opening movement of the flap 2 is expected even if the brake arrangement 7 is functional. This can also be mapped in the braking error criterion, with movement limit values within the self-locking range being selected to be lower than outside of the self-locking range, for example. It is also conceivable that the braking error criterion is only checked within the self-locking range.

Furthermore, it is preferably provided here that the braking error criterion relates to the fact that the flap 2 automatically leaves the self-retaining area.

It can be specified here that the flap 2 does not leave the self-holding area when the brake arrangement 7 is functional, for example after the flap 2 has already reached a holding flap position. If, based on the drive values, a flap position is then determined outside the self-retaining range, this indicates a faulty brake arrangement 7 .

Also disclosed within the scope of the present application, according to a further teaching which is of independent importance, is a flap arrangement of a motor vehicle 3 with a flap 2 and a proposed drive arrangement 1 assigned to the flap 2.

Also disclosed within the scope of the present application, according to a further teaching that is of independent importance, is a method for operating the proposed drive arrangement 1 for motorized adjustment of a flap 2 of a motor vehicle 3.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2009059747 A1 [0003, 0020]

Claims (5)

Drive arrangement for motorized adjustment of a flap (2) of a motor vehicle (3), the drive arrangement (1) being equipped with a drive (4) which has an electric drive motor (5) and a feed gear (6) downstream of the drive motor (5) in terms of drive technology. for generating linear drive movements, the drive (4) being equipped with a brake arrangement (7) which can be engaged/disengaged via a freewheel arrangement, the drive arrangement (1) having a control arrangement (8) which controls the drive (4) in order to to adjust the flap (2) in an adjustment range for the flap position, and wherein the control arrangement (8) determines drive values of the drive arrangement (1) which are representative of a flap movement, characterized in that the control arrangement (8) when the flap ( 2) the drive values are monitored to ensure that a specified braking error criterion is met, and that the control arrangement (8) provides a braking routine for motorized adjustment when the braking error criterion is met, in which the control arrangement (8) controls the drive (4) in such a way that the drive arrangement (1) with a motor braking effect on the flap (2) works. Drive arrangement according to claim 1 , characterized in that the control arrangement (8) monitors the drive values during motorized adjustment of the flap (2) to ensure that a trapping criterion and/or collision criterion of the flap (2) is met, and that the control arrangement (8) monitors the trapping criterion and/or the collision criterion Fulfillment of the braking error criterion modifies, preferably that the control arrangement (8) reduces a limit value of the trapping criterion and/or collision criterion for the drive value. Drive arrangement according to claim 1 or 2 , characterized in that the braking error criterion is specified on the basis of a movement limit value of the drive values being exceeded in the holding state, preferably that the movement limit value relates to a maximum flap speed and/or flap acceleration, more preferably that the braking error criterion only applies if a specified value is not met, a manual actuation action on the flap (2) representing actuation criterion is considered to be fulfilled by the drive values. Drive arrangement according to one of the preceding claims, characterized in that the braking error criterion is specified as a function of the flap position, preferably that a self-retaining range of the flap position in the adjustment range is specified for the drive arrangement (1), and that the braking error criterion is defined differently within the self-retaining range than outside of the self-hold area. Drive arrangement according to one of the preceding claims, characterized in that the braking error criterion relates to the flap (2) automatically leaving the self-retaining area.

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