Arrangement for independently actuating two subsystems in a motor vehicle by means of an electric machine

Abstract

The invention relates to an arrangement (1) for independently actuating two subsystems (3, 4) in a motor vehicle, comprising an electric machine (2), wherein a first subsystem (3) can be actuated by means of the electric machine (2) in a first direction of rotation and a second subsystem (4) can be actuated by means of the electric machine (2) in a second direction of rotation, and wherein, in the second direction of rotation, the electric machine (2) experiences at least one defined resistance in at least one defined travel range and in this way the control position of the second subsystem (4) can be determined by means of a current and travel measurement in the electric machine (2).

Description

[0001] Arrangement for the independent operation of two subsystems in a motor vehicle by means of an electric machine

[0002] Field of the invention

[0003] The present invention relates to an arrangement for the independent actuation of two subsystems in a motor vehicle, comprising an electric machine, wherein a first subsystem can be actuated via the electric machine in a first direction of rotation and a second subsystem can be actuated via the electric machine in a second direction of rotation.

[0004] State of the art

[0005] Arrangements described above are already disclosed in the prior art.

[0006] For example, the document DE 102019 201 664 B4 discloses a system for actuating a parking lock in a transmission with an electric machine which is connected via at least one freewheel to a pump for the hydraulic system of the transmission and to an eccentric arrangement, wherein the eccentric arrangement engages and disengages a parking lock.

[0007] By combining two tasks in one electric drive, it is used more efficiently and an additional electric motor for actuating a parking lock is eliminated.

[0008] However, in this technical design, only one direction of rotation of the electric motor is available for “opening” and “closing” the parking lock, which requires the integration of an additional sensor close to the parking lock, via which the (final) position of the parking lock unit can be determined.

[0009] Summary of the invention

[0010] It is an object of the invention to provide an arrangement for the independent actuation of two subsystems in a motor vehicle with an electric machine, which addresses the above-mentioned problem and enables a (final) position determination of at least one subsystem in a simple manner without an additional sensor.

[0011] This need can be met by the subject matter of the present invention according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims.

[0012] The arrangement according to the invention serves for the independent operation of two subsystems in a motor vehicle.

[0013] According to the invention, the arrangement comprises an electrical machine, wherein a first subsystem can be actuated via the electrical machine in a first direction of rotation and a second subsystem can be actuated via the electrical machine in a second direction of rotation.

[0014] According to the present invention, the electric machine experiences at least a defined resistance in at least one defined travel range in the second direction of rotation, wherein the switching position of the second subsystem can be determined via a current and travel measurement in the electric machine. In a particularly preferred embodiment of the present invention, the first subsystem is designed as a coolant pump and the second subsystem as a parking lock or as a switching unit. In this context, a switching unit can be understood in particular as a separating clutch of any type or a gearshift clutch of any type.

[0015] The electric machine is preferably connected to the second subsystem via a freewheel.

[0016] Furthermore, in a particularly preferred embodiment of the present invention, a switching gate is formed on a rotating component in an actuator path for actuating the second subsystem, against which a spring-mounted locking element rests, wherein the second switching gate has an opening-relevant area and a closing-relevant area with respective neutral areas in between, wherein the opening-relevant area and the closing-relevant area each have a locking recess into which the locking element can engage.

[0017] The second switching gate preferably has, starting from the locking recess in the opening-relevant region in the second direction of rotation, at least one first locking transition section with a first transition gradient and a first locking end section with a first end gradient.

[0018] Furthermore, the second switching gate preferably has, starting from the locking recess in the closing-relevant region in the second direction of rotation, at least one second locking transition section with a second transition gradient and a second locking end section with a second end gradient.

[0019] The inventive design of the arrangement for the independent actuation of two subsystems by means of an electric motor not only combines two tasks in one electric drive and thus ensures extremely efficient use of the electric motor, but also allows the (end) position of the second subsystem to be determined easily without having to install an additional sensor in the area of ​​the second subsystem. This allows for a particularly cost-optimized design of the arrangement.

[0020] Brief description of the drawings

[0021] The invention is described below by way of example with reference to the drawings.

[0022] Fig. 1 shows a schematic representation of an arrangement for

[0023] Actuation of two subsystems by means of an electrical machine.

[0024] Fig. 2 shows a schematic detailed side view of an actuator unit for actuating a parking lock.

[0025] Fig. 3 shows a schematic side view of a first switching gate on a rotating component in an actuator path.

[0026] Fig. 4a shows a schematic side view of a locking recess in a closing-relevant area of ​​a second switching gate.

[0027] Fig. 4b shows a schematic side view of a locking recess in an opening-relevant area of ​​a second shift gate. Detailed description of the invention

[0028] Fig. 1 shows an arrangement 1 for the independent actuation of two subsystems 3, 4 of a motor vehicle by means of an electric machine 2.

[0029] The arrangement 1 comprises an electric machine 2, which is drive-connected to a first subsystem 3 and a second subsystem 4 via an output shaft. Furthermore, the electric machine 2 is communicatively connected to a control and processing unit 8 via a contact line.

[0030] In the illustrated embodiment of the arrangement according to the invention, the first subsystem 3 is designed as a coolant pump 3a and the second subsystem 4 as a parking lock 4a.

[0031] In a first direction of rotation of the electric machine 2, the first subsystem 3 can be actuated via the electric machine 2. If the first subsystem 3 is formed by the coolant pump 3a, a volume flow for cooling and / or lubricating components of the motor vehicle can be provided in this way.

[0032] In a second direction of rotation of the electric machine 2, the second subsystem 4 can be actuated via the electric machine 2. If the second subsystem 4 is formed by the parking lock 4a, opening and closing of the parking lock 4a can be initiated in this way.

[0033] The electric machine 2 is connected to the second subsystem 4, i.e. the parking lock 4a, via a freewheel 5 and an actuator unit 7.

[0034] The actuator unit 7 converts the rotary motion of the electric machine 2 into a translatory motion to actuate the second subsystem 4. When the electric machine 2 is operated in a first direction of rotation, the actuator unit 7 is not operated—it is decoupled from the electric machine 2 by the freewheel 5—and thus the parking lock 4a is actuated neither in the opening nor in the closing direction. In this operating state, a minimal friction torque is transmitted via the freewheel to the second subsystem 4, i.e., the parking lock 4a.

[0035] As soon as there is a request for actuation of the parking lock 4a, the direction of rotation of the electric machine 2 is changed from the first direction of rotation to the second direction of rotation via the control and computing unit 8, so that the first subsystem 3, i.e. the coolant pump 3a, is essentially deactivated and the actuator unit 7 and thus the parking lock 4a is activated in the opening or closing direction.

[0036] When the parking lock 4a is actuated, the coolant pump 3a briefly sucks instead of pumping. This short-term state of the coolant pump 3a is not relevant for a cooling and / or lubrication circuit.

[0037] In Fig. 2, a section of an actuator unit 7 for actuating the parking lock 4a is shown as an example.

[0038] The electric machine 2 drives at least one rotating component 10 of the actuator unit 7. The rotating component 10 is fixedly mounted, namely in a rotationally fixed and axially fixed manner, on an axially displaceable sliding sleeve 13. Two shift gates, namely a first shift gate 11 and a second shift gate 6, are formed on the rotating component 10. A spring-mounted locking element 9 rests against the second shift gate 6 (Fig. 2).

[0039] The direction axial describes a direction along or parallel to a central axis 18.

[0040] The locking element 9 is designed, for example, as a ball detent and comprises a locking ball which is pressed against the switching gate 6 on the rotating component under the action of a compression spring mounted in a bushing (Fig. 2).

[0041] Fig. 3 shows a schematic section of the first shift gate 11. The first shift gate is used for shifting, namely opening and closing, the parking lock 4a. The first shift gate 11 is designed as an "endless gate", for example rotationally symmetrical. The first shift gate 11 is formed on the end face of the rotating component 10 of the actuator unit 7 and drives against a fixed component 12, wherein an elastic element 14 preloads the rotating component 10 and thus the sliding sleeve 13 into a first position corresponding to an open parking lock 4a, and the sliding sleeve 13 can be transferred against the spring force of the elastic element 14 into a second position corresponding to a closed parking lock 4a.

[0042] Fig. 4a and Fig. 4b each schematically illustrate a section of the second shift gate 6, wherein the second shift gate 6 has an opening-relevant region DC and a closing-relevant region C, with respective neutral regions 19 in between, alternating around its circumference. The second shift gate 6 is designed as an "endless gate," for example, rotationally symmetrical, which enables actuation via one direction of rotation of the electric motor 2 in both switching positions of the parking lock 4a. The opening-relevant region DC and the closing-relevant region C each have a locking recess 15 into which the locking ball of the locking element 9 can engage.

[0043] Starting from the locking recess 15, the second switching gate 6 has in the opening-relevant area DC in the second direction of rotation at least a first locking transition section 16a with a first transition gradient and a first locking end section 17a with a first end gradient (Fig. 4a, Fig. 4b).

[0044] Starting from the locking recess 15, the second switching gate 6 has, in the closing-relevant region C in the second direction of rotation, at least one second locking transition section 16b with a second transition gradient and a second locking end section 17b with a second end gradient (Fig. 4a, Fig. 4b).

[0045] When the electric motor 2 is actuated in the first direction of rotation, a minimal frictional torque is transmitted via the freewheel 5 to the second subsystem 4, i.e., the parking lock 4a. In this way, but also generally, the mechanical resistance (ball detent in a detent recess) can also be used to fix the second subsystem 4, i.e., the parking lock 4a, or to hold it in position and prevent unintentional switching.

[0046] To represent a calibration mode, the electric machine experiences a defined resistance over a defined travel range when actuated in the second direction of rotation via the respective transition gradient of the first locking transition section or the second locking transition section 16b. Via a current and travel measurement in the electric machine 2, more precisely via the control and computing unit 8 of the electric machine 2, the switching position of the parking lock 4a can be determined by the different configuration of the locking transition sections 16a, 16b with different transition gradients in the respective DC, C ranges.

[0047] In a calibration mode, the electric machine 2 can be operated in a speed-controlled mode in which a defined current must not be exceeded (current limitation). With this current, the respective detent end section 17a, 17b cannot be overrun. Starting from the detent recess 15, the electric machine 2 would move into or onto the respective detent end section 17a, 17b. The path traveled allows the absolute position of the parking lock 4a to be determined. The current required for this (e.g., current integral) allows the gradient to be determined and, in turn, the position of the parking lock 4a to be determined. Both pieces of information can be obtained redundantly, thus ensuring the required system integrity (ASIL B).

[0048] The calibration mode should be able to be executed multiple times, which is why the mechanical system / mechanical resistance must have a reset function in which the actuator unit 7 is moved from the detent end section 17a, 17b back into the detent recess 15. For example, a reset function can be generated via the spring-loaded ball of the detent element 9 and the respective transition pitch in the respective detent transition section 16a, 16b. The electric motor 2 cannot actively reset via the freewheel 5 - however, the electric motor 2 can and should be "assisted" so that the mechanical system does not have to generate the entire force (and friction) for the reset.This movement towards “pump operation”, i.e. in the first direction of rotation of the electric machine 2, helps with resetting and could at the same time also make the hydraulic system “ready for operation” again, since the coolant pump 3a was operated incorrectly when the parking lock 4a was engaged.

[0049] If the parking lock 4a is to be switched, the electric machine 2 is operated with a current that is greater than the limit in the calibration mode, allowing the respective detent end section 17a, 17b to be overrun. The actual switching of the parking lock 4a takes place afterwards. The next calibration or detent position can be traveled with path control, where the end position can be determined again. A time must be allowed for the position determination. In the event of an error or system failure in the switching range or possibly during initial commissioning, a "search function" must be integrated with which a detent position can be found. This can be done almost analogously to the calibration mode described.

[0050] List of reference symbols

[0051] 1 arrangement

[0052] Electric machine

[0053] First subsystem a coolant pump

[0054] Second subsystem a parking lock

[0055] Freewheel

[0056] Second shift gate

[0057] 7 Actuator unit

[0058] 8 Control and computing unit

[0059] 9 locking element

[0060] 10 Rotating component

[0061] 11 First shift gate

[0062] 12 Fixed component

[0063] 13 Sliding sleeve

[0064] 14 Elastic element

[0065] 15 Recess

[0066] 16a First rest transition section

[0067] 16b Second rest transition section

[0068] 17a First resting section

[0069] 17b Second resting section

[0070] 18 Central Axis

[0071] C Closing-relevant area (of the second switching gate)

[0072] DC Opening-relevant area (of the second switching gate)

Claims

Patent claims 1. Arrangement (1) for the independent actuation of two subsystems (3, 4) in a motor vehicle, comprising an electrical machine (2), wherein a first subsystem (3) can be actuated via the electrical machine (2) in a first direction of rotation and a second subsystem (4) can be actuated via the electrical machine (2) in a second direction of rotation, characterized in that the electrical machine (2) experiences at least one defined resistance in at least one defined travel range in the second direction of rotation and the switching position of the second subsystem (4) can be determined in this way via a current and travel measurement in the electrical machine (2).

2. Arrangement (1) according to claim 1, characterized in that the first subsystem (3) is a coolant pump (3a) and the second subsystem (4) is a parking lock (4a) or a switching unit.

3. Arrangement (1) according to claim 1 or 2, characterized in that the electrical machine (2) is connected to the second subsystem (4) via a freewheel (5).

4. Arrangement (1) according to claim 1, 2 or 3, characterized in that in an actuator path for actuating the second subsystem (4) on a rotating component (10) a second switching gate (6) is formed, against which a spring-mounted locking element (9) rests, wherein the second switching gate (6) has an opening-relevant area (DC) and a closing-relevant area (C) with respective neutral areas in between, wherein the opening-relevant area (DC) and the closing-relevant area (C) each have a locking recess (15) into which the locking element (9) can lock.

5. Arrangement (1) according to claim 4, characterized in that the second switching gate (6), starting from the locking recess (15) in the opening-relevant region (DC) in the second direction of rotation, has at least one first locking transition section (16a) with a first transition gradient and a first locking end section (17a) with a first end gradient, and that the second switching gate (6), starting from the locking recess (15) in the closing-relevant region (C) in the second direction of rotation, has at least one second locking transition section (16b) with a second transition gradient and a second locking end section (17b) with a second end gradient.

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