Method for operating an actuating device and actuating device

Abstract

The present disclosure relates to a method for operating an actuating device (1) with an actuator (2) which, for actuating an actuating element (3), can be rotated in one direction of rotation from a starting position to an actuating position and, for returning the actuating element (3) to its starting position, can be rotated in the same direction of rotation from the actuating position to the starting position, wherein, when a stop signal is received during actuating, the actuator (2) is rotated beyond the actuating position towards its starting position at least at undiminished speed. Furthermore, the present disclosure relates to an actuating device (1) with an actuator (2) which can be operated by such a method.

Description

[0001] The present disclosure relates to a method for operating an actuating device having an actuator that is rotatable in a rotational direction from an initial position, in particular from a bottom dead center position, to an actuating position, in particular to a top dead center position, for actuating an actuating element / element to be actuated, and is rotatable in the same rotational direction from the actuating position to the initial position for returning the actuating element. Furthermore, the present disclosure relates to an actuating device having an actuator that is operable using the method.

[0002] Such actuating devices with an actuator are already known from the prior art, for example from DE 10 2022 124 760 B3, which, due to the transmission / mechanical coupling with the element to be actuated, realizes an oscillating forward and backward movement (of the element to be actuated) from (only) one direction of rotation of the actuator / actuator drive, for example to switch a function on or off (i.e., to actuate or reset / close or open). Actuating devices with a reversing actuator are also known from the prior art, for example from DE 10 2021 125 611 A1, which can be operated / driven for forward movement (of the element to be actuated) in one direction of rotation and for reverse movement (of the element to be actuated) in the other direction of rotation.

[0003] From the publications DE 10 2016 119 077 A1 and DE 10 2014 200 257 A1, further actuating devices and methods for operating an actuating device are known in which the actuator rotates to its initial position when the user's actuation ends.

[0004] It is problematic if, after the actuator has started an adjustment / actuation movement, i.e. when the actuator is no longer in its initial position, a so-called change-of-mind situation occurs, i.e. a situation in which the actuator's adjustment / actuation movement is to be aborted. A direct reversal of the actuator's direction is not possible in this case. The actuator is usually stopped in the (intermediate) position it is in at the time of a abort signal, which can lead to function- and / or safety-critical stop positions of the actuator. At a permissible time, the actuator's adjustment / actuation movement (in particular the initiated closing movement) can be ended before a normal actuation movement (in particular a normal opening movement) can follow.

[0005] Against this background, the present disclosure is based on the object of avoiding or at least mitigating the disadvantages of the prior art. In particular, the aim is to prevent the possibility of functionally and / or safety-critical stop positions of the actuator occurring in a so-called change-of-mind situation.

[0006] This object is achieved by a method having the features of the independent patent claim. Furthermore, the object is achieved by an actuating device having the features of the independent patent claim. Advantageous further developments are the subject of the dependent claims.

[0007] In particular, the problem is solved in terms of process technology in that, when a stop signal (to stop the actuating movement) is received during actuation, the actuator rotates (in the direction of rotation) at at least an undiminished, i.e., at least a constant / unreduced, speed, in particular beyond the actuating position / top dead center position, toward its initial position. This means that, upon receipt of the stop signal, the actuator is not immediately decelerated or stopped to force an immediate stop or a stop in the actuating position, but, on the contrary, continues to rotate out of a potentially function- and / or safety-critical stop position.

[0008] The core of the disclosure or invention is that the abort signal does not trigger a speed reduction, but rather a continuation of the adjustment / actuation movement at least at the same speed beyond the actuation position in order to avoid the actuator coming to a standstill in a critical stop position for a longer period of time.

[0009] In other words, the object is achieved by a method for operating an actuating device with an actuator which is rotatable in a direction of rotation from an initial position, in particular from a bottom dead center position, into an actuating position, in particular into a top dead center position, for actuating an actuating element / element to be actuated, and is rotatable in the same direction of rotation from the actuating position into the initial position for returning the actuating element, wherein the actuator, when a cancellation signal is received, rotates at least undiminished speed beyond the actuating position in the direction of its initial position.

[0010] According to a preferred embodiment, when the abort signal is received, the actuator can rotate at an accelerated speed toward its starting position. This means that the actuator's adjustment / actuation movement is not only not decelerated, but is deliberately accelerated. This shortens the time until the actuator returns to its "safe" starting position, so that a critical stop position can be avoided or passed through as quickly as possible. Thus, the described actuator can be brought to a safe stop position even faster than a reversing actuator, which is stopped and rotated back upon receipt of the abort signal.

[0011] According to a preferred embodiment, when the abort signal is received, the actuator can rotate to its initial position and remain there. This means that after the abort signal is received, the actuator deliberately rotates to its initial position and only stops there. This has the advantage that the critical stop position is passed through, preferably at an accelerated rate, i.e., as quickly as possible, and the actuator only comes to a stop in a safe stop position.

[0012] According to a preferred embodiment, the actuator can be deliberately decelerated before reaching the starting position, so that it comes to a stop in the starting position. This means that the actuator, which is preferably initially accelerated after receiving the abort signal, is deliberately decelerated to prevent it from overrunning / moving beyond the starting position (and thus coming to a stop in a critical stop position).

[0013] According to a preferred embodiment, the actuator can be deliberately decelerated before reaching the actuating position, particularly if no abort signal is received / during normal operation, so that it comes to a stop in the actuating position, i.e., does not overshoot the actuating position. This ensures safe actuation of the element to be actuated.

[0014] The object of the present disclosure is also achieved by an actuating device with an actuator that can be operated with / according to a described method. The actuator is rotatable in one direction of rotation from an initial position (in particular from a bottom dead center) to an actuating position (in particular to a top dead center) to actuate an actuating element, and is rotatable in the same direction of rotation from the actuating position to the initial position to return the actuating element.

[0015] According to a preferred embodiment, the actuator can be used to actuate and reset a coupling device, preferably in an electrified motor vehicle drive train. In particular, the actuator can be used to engage and disengage an electric axle. Especially in such an application for axle engagement, it can happen that a fault occurs during engagement of the coupling device / components of the coupling device, i.e. when the speed of the axle to be engaged and the already driving axle is already synchronized and when the closing movement of the coupling device / components of the coupling device has begun, so that it is more advantageous to complete the closing movement quickly. Because the fault often only leads to a critical state after a time delay, the described actuator may have already completed the closing movement and be in the opening movement when the critical state is reached.In particular, the described actuator can thus be in a position at the earliest possible time in which the coupling device / components of the coupling device have no tooth contact position.

[0016] According to a preferred embodiment, the actuator can be used to actuate and reset a parking lock. Even in the application area of ​​parking lock actuation, certain functionally and / or safety-critical positions of the parking lock can arise, which can be quickly passed through by the described actuator.

[0017] According to a preferred embodiment, the actuator can be driven / operated / rotated in a second rotational direction to actuate another actuating element. This means that the second rotational direction of the actuator can be used to actuate, i.e., to actuate and reset, another / second actuating element.

[0018] According to a preferred embodiment, the actuator can be driven / operated / rotated to convey fluid in a second direction of rotation. This means that the second direction of rotation of the actuator can be used to convey a fluid, in particular a cooling fluid for cooling certain drive components. In particular, the actuator can have a pump for this purpose, which conveys fluid by rotating the actuator or the electric motor in the second direction of rotation. When using a reversing pump with a corresponding hydraulic rectifier, fluid can be conveyed in both directions of rotation.

[0019] According to a further development of the preferred embodiment, the actuator can have an (electric) motor with a (single) output shaft, via which the motor is coupled both to the actuation of the actuating element and to the conveying of the fluid. This has the advantage that installation space can be saved and a control unit of the actuator can be more easily placed or mounted on the actuator (or no hole is required in the control unit, in particular the circuit board). Alternatively, the motor can have two output shafts, with the motor being coupled to the actuation of the actuating element via one output shaft and to the conveying of the fluid via the other output shaft.

[0020] In other words, the disclosure relates to a method for operating an actuating device with only one direction of rotation. Due to their transmission ratio, such actuators implement an oscillating forward and backward movement from one direction of rotation of the actuator drive, for example to switch a function on or off. Such a function can be, for example, the switching of a so-called separation unit in an electrified powertrain. In particular, one possible embodiment of this operating principle can be the so-called cooling + 1, in which a first direction of rotation of the actuator drive is used for conveying a fluid and the second direction of rotation is used for actuating a separation unit or parking lock. In this embodiment, when actuation is requested, the actuator moves to the top dead center of the actuation and remains there until the request to open occurs, at which time the actuator continues to rotate in the same direction of rotation (as before).To prevent the top dead center from being accidentally overrun, the speed must be reduced well before reaching the top dead center. If a so-called change-of-mind situation occurs after the intentional or even unintentional request for actuation (triggering the adjustment movement), the actuator can only be stopped due to its operating principle, since a direct reversal of direction is not possible, which can lead to functionally and safety-critical stop positions of the actuator. In this case, the closing movement must be completed at a permissible time before a normal opening movement can follow.

[0021] In the described method, the actuator should not be stopped if a change-of-mind situation occurs, but should travel past top dead center at at least the same speed and deliberately only stop at bottom dead center (open). Preferably, upon receipt of the change-of-mind signal / abort signal, the actuator is accelerated even further until it has passed top dead center, before targeted braking begins to bring the actuator to a safe stop at bottom dead center. This control strategy is particularly important for function- and safety-critical malfunctions, such as the transmission of unwanted torque, for which so-called fault tolerance times exist. The fault tolerance times are so short that a vehicle does not react disruptively or critically to an incorrectly introduced wheel torque due to inertia and elasticity.In other words, the control strategy is not to brake (in order to avoid possibly coming to a standstill in the critical state for a longer period of time), but to drive through the critical state as quickly as possible (in order to then come to a safe stop in the safe state).

[0022] The disclosure is explained below with the help of drawings: Fig. 1 and Fig. 2 show schematic diagrams of a structure of an actuating device according to the present disclosure, Fig. 3 shows a flowchart of a method according to the present disclosure, Fig. 4 shows a graph in which qualitative time courses of the process are shown in comparison to a process of a reversing actuator, and Fig. 5 shows a graph in which a path behavior of the method is shown in comparison to a method of the reversing actuator.

[0023] Fig. 1 and Fig. 2 show schematic diagrams of a structure of an actuating device 1 according to the present disclosure. The actuating device 1 has an actuator 2. The actuator 2 serves to actuate or reset, in particular to cause an oscillating back-and-forth movement / forward-and-back movement / stroke movement of an actuating element 3. The actuator 2 is rotatable in a (first) direction of rotation to actuate the actuating element 3 from an initial position into an actuating position and in the same (first) direction of rotation from the actuating position to the initial position to return the actuating element. In the actuating position, the actuator 2 is located in particular at a top dead center. In the initial position, the actuator 2 is located in particular at a bottom dead center.

[0024] In the (first) direction of rotation, the actuator 2 can be used, in particular, to actuate (i.e., close) and reset (i.e., open) a coupling device, preferably for engaging an (electric) drive axle in an electrified motor vehicle drive train as needed. Alternatively, the actuator 2 can be used to actuate and reset a parking lock.

[0025] In Fig. 1, the actuator 2 has a motor 4 which is coupled to an eccentric mechanism 5 via a first freewheel 23 in order to translate a rotation of the motor 4 into a (first) translational movement. The eccentric mechanism 5 is coupled to a crank 7 having a (second) freewheel 6 in order to translate the (first) translational movement into a rotational movement or pivoting movement of the crank 7. The crank 7 does not rotate through 360°, but rather a back-and-forth movement which is transmitted in a first direction by the freewheel 6 to the actuating element 3 and overtaken by the freewheel 6 in another direction opposite to the first direction. The crank 7 is coupled to the actuating element 3 in order to translate the rotation of the crank 7 into a (second) translational movement of the actuating element 3. This means that the rotation of the motor 4 in the (first) direction of rotation is coupled with the stroke movement of the actuating element 3.

[0026] In Fig. 2, the actuator 2 comprises the motor 4, which is coupled via the first freewheel 23 to a gearing mechanism 8 (to translate a rotation of the motor 4 into a rotation of gears of the gearing mechanism 8). The gearing mechanism 8 is coupled to the crank 7, which has the (second) freewheel 6, to translate the rotation of the gears into a rotation or reciprocating movement of the crank 7. The crank 7 is coupled to the actuating element 3 to translate the rotation of the crank 7 into a translational movement of the actuating element 3. This means that the rotation of the motor 4 in the (first) direction of rotation is coupled to the reciprocating movement of the actuating element 3.

[0027] Preferably, the actuator 2 can be rotatable in a second direction of rotation (opposite to the first direction of rotation) to convey fluid. In particular, the motor 4 is coupled to a pump 24 for this purpose. Preferably, the motor 4 can have (only / exactly) one output shaft, via which the motor 4 is coupled both to the lifting movement of the actuating element 3 (i.e., the eccentric mechanism 5 or the toothed mechanism 8) and to the fluid conveyance (i.e., the pump 24). The illustrations in Fig. 1 and Fig. 2 are merely schematic diagrams in which the connection of the motor 4, in particular the coupling via the one (single) output shaft, is not precisely depicted. Alternatively, the motor 4 can have two output shafts, with the motor 4 being coupled to the lifting movement of the actuating element 3 via one output shaft and to the fluid delivery via the other output shaft.

[0028] Alternatively, the actuator 2 could be rotatable in the second direction of rotation (opposite to the first direction of rotation) to actuate a further actuating element, even if this is not shown.

[0029] Fig. 3 shows a schematic sequence of a method for operating the actuating device 1. In step 9, an enable occurs. With the enable, a movement of the actuator 2 in the direction of actuation (closing) begins, i.e. in the direction of the actuated position. In step 10, a setpoint is specified for the actuator 2. The setpoint is specified with the aim of moving the actuator 2 exactly into the actuated position (i.e. with the aim of precisely engaging ( / actuating / closing or an engaging position / actuated position) or at a limited speed). In step 11, a query is made as to whether a cancellation signal ( / change-of-mind signal) is received. If the query for the cancellation signal is negative, no change to the (setpoint) specification takes place in step 12. If the query of the abort signal is positive, ie if an abort signal is received, a modified setpoint value is specified for actuator 2 in step 13.The modified setpoint specification is made with the aim of ensuring that actuator 2 moves (quickly) through the actuating position ( / the insertion position), in particular at an increased speed. A new setpoint specification is made in step 14. The new setpoint specification is made with the aim of ensuring that actuator 2 is decelerated and stops in the starting position ( / in a disengaged position).

[0030] This means that when a stop signal is received, the actuator 2 rotates at least at an undiminished speed, preferably at an accelerated speed, beyond the actuating position towards its starting position, before being deliberately braked before reaching the starting position until it comes to a stop in the starting position.

[0031] Fig. 4 and Fig. 5 show graphical representations of qualitative time courses of the actuating device according to the disclosure in comparison with the qualitative time courses of an actuating device known from the prior art with a reversing actuator which uses different directions of rotation for actuation and resetting (for closing and opening) and which is braked in the event of a change-of-mind situation / when a cancellation signal is received and is rotated back to its initial position in the opposite direction of rotation.

[0032] On an x-axis of the Fig. 4 and Fig. 5 a time t, measured in milliseconds, is applied. On a (left) y-axis of the Fig. 4 is a speed and a cooling 15, measured in percent. On a (right) y-axis of the Fig. 4 shows a status 16 of a signal, a release and a moment. On a y-axis of the Fig. 5 is a rotation and a path 17, measured in percent, applied. In the Fig. 4 and Fig. In Figure 5, characteristic curves of the disclosed actuating device 1 are shown in dashed lines, while those of the prior art actuating device are shown in solid lines. When the lines are superimposed, only the solid line is visible. This means that the course of the dashed line corresponds to the course of the solid line of a respective characteristic curve if the dashed line is not shown in the corresponding area.

[0033] Initially, a signal characteristic curve 18 has the status 1. However, actuator 2 initially does not move until the enable signal is given (see step 9) and an enable characteristic curve 19 has the status 1. Actuator 2 moves according to its setpoint (see step 10), and a speed characteristic curve 20 increases linearly. Upon receipt of the abort signal (see step 11), signal characteristic curve 18 has the status 0, and the enable characteristic curve 19 also goes to the status 0.

[0034] From this point of release change, the speed characteristic curve 20 of the reversing actuator decreases linearly until the reversing actuator stops. Then, the speed characteristic curve 20 of the reversing actuator increases linearly in the negative direction (i.e., in the opposite direction of rotation) to a negative maximum, before the speed characteristic curve 20 of the reversing actuator decreases linearly again before reaching the initial position. A torque characteristic curve 21 of the reversing actuator has a status of 1.5 in the range between 47 and 68 milliseconds.

[0035] In contrast, the speed characteristic curve 20 of actuator 2 continues to rise linearly from this point of the release change to a maximum, before the speed characteristic curve 20 of actuator 2 falls linearly again before reaching the initial position. The torque characteristic curve 21 of actuator 2 has a status of 1.5 in the range between 47 and 63 milliseconds.

[0036] Accordingly, a travel characteristic curve 22 of the reversing actuator and actuator 2 is at 0 percent at one point in time. After that, the travel characteristic curve 22 of the reversing actuator increases with a decreasing gradient, before the travel characteristic curve 22 of the reversing actuator decreases again (slowly) with an increasing gradient. In contrast, the travel characteristic curve 22 of actuator 2 increases with an increasing gradient / approximately exponentially (increasing more rapidly than the travel characteristic curve 22 of the reversing actuator) before decreasing again (rapidly) with a decreasing gradient / approximately exponentially (decreasing more rapidly than the travel characteristic curve 22 of the reversing actuator). It is crucial that the travel characteristic curve 22 of the actuator 2 falls below a “non-critical 10 percent limit” of a travel earlier than the travel characteristic curve 22 of the reversing actuator, at which there is (still or again) no tooth contact of a coupling device actuated by the actuator 2 (or the reversing actuator). List of reference symbols 1 actuating device 2 Actuator 3 Actuating element 4 Engine 5 Eccentric mechanism 6 (second) freewheel 7 Crank 8 Gearing mechanism 9 Step 10 steps 11 Step 12 steps 13 Step 14 Step 15 Speed ​​and cooling 16 Status 17 Speed ​​and distance 18 Signal characteristic curve 19 Release characteristic curve 20 Speed ​​characteristic curve 21 Torque characteristic curve 22 Path characteristic 23 (first) freewheel 24 Pump t time

Claims

[1] Method for operating an actuating device (1) with an actuator (2) which is rotatable in one direction of rotation from an initial position into an actuating position for actuating an actuating element (3) and is rotatable in the same direction of rotation from the actuating position into the initial position for returning the actuating element (3), characterized by that the actuator (2), if a cancellation signal is received during actuation, is rotated at least at an undiminished speed beyond the actuating position in the direction of its initial position. [2] Method according to claim 1, characterized by that the actuator (2), when the abort signal is received, is rotated at accelerated speed towards its initial position. [3] Method according to claim 1 or 2, characterized by that the actuator (2), when the abort signal is received, is rotated to its initial position and remains in the initial position. [4] Method according to one of claims 1 to 3, characterized by that the actuator (2) is deliberately braked before reaching the starting position so that it comes to a stop in the starting position. [5] Method according to one of claims 1 to 4, characterized by that the actuator (2), in normal operation of the actuator (2), is deliberately braked before reaching the actuating position so that it comes to a standstill in the actuating position. [6] Actuating device (1) with an actuator (2) which can be operated by a method according to one of claims 1 to 5, wherein the actuator (2) is rotatable in a direction of rotation from an initial position into an actuating position for actuating an actuating element (3) and is rotatable in the same direction of rotation from the actuating position into the initial position for returning the actuating element (3). [7] Actuating device (1) according to claim 6, characterized bythat the actuator (2) serves to actuate and reset a coupling device. [8] Actuating device (1) according to claim 6, characterized by that the actuator (2) serves to actuate and reset a parking lock. [9] Actuating device (1) according to one of claims 6 to 8, characterized by that the actuator (2) can be driven in a second direction of rotation to actuate a further actuating element. [10] Actuating device (1) according to one of claims 6 to 8, characterized by that the actuator (2) can be driven in a second direction of rotation to convey fluid.

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