Vehicle parking lock device

Abstract

The invention relates to a vehicle parking lock device (1) comprising an actuator (2) and a parking lock mechanism (3), wherein the actuator (2) interacts with the parking lock mechanism (3) in such a way that the parking lock mechanism (3) can be moved by the actuator (2) into a parking lock locking position and a parking lock release position, wherein the actuator (2) has a first linear actuator element (4) and a second linear actuator element (5) which are coupled to each other in such a way that the linear offset (6) of the actuator (2) can be provided by the linear offset (7) of the first linear actuator element (4) and the linear offset (8) of the second linear actuator element (5).

Description

[0001] The present invention relates to a vehicle parking lock device comprising an actuator and a parking lock mechanism, wherein the actuator interacts with the parking lock mechanism in such a way that the parking lock mechanism can be transferred by the actuator into a parking lock locking position and a parking lock release position.

[0002] To prevent motor vehicles from accidentally rolling away, e.g., on a slope, vehicles can be equipped with a vehicle parking lock device, which creates a positive locking of the driven vehicle wheels within the vehicle drivetrain, thus preventing the vehicle from rolling away. This function is similar to a handbrake in the vehicle. While a handbrake is usually intended to prevent the driven vehicle wheels from being locked by force, a vehicle parking lock device achieves this through a positive locking mechanism within the vehicle drivetrain.

[0003] Particularly when non-mechanical components are installed in a motor vehicle's drivetrain, such as automatic transmissions with hydrodynamic torque converters or electric vehicles, vehicle parking lock devices serve to prevent the vehicle from accidentally rolling away when the vehicle is stationary or the engine is switched off. For this purpose, the vehicle parking lock device can be activated mechanically, electrically, and / or hydraulically by the driver using a parking lock operating device.

[0004] The vehicle parking lock device typically blocks a shaft within the power flow in a vehicle drivetrain, for example of an automatic transmission or a downstream differential axle gear. The shaft to be blocked is selected such that its blocking reliably prevents movement of the vehicle's drive wheels. When a vehicle is parked on a slope, for example, the vehicle's weight can generate large forces on the parking lock mechanism, depending on the wheel diameter and the gear ratio. Since these high applied forces must be overcome when unlocking the vehicle parking lock device on a slope, purely manual unlocking cannot always be carried out safely and easily for a user. Consequently, electric and / or hydraulic actuators have become established for power-assisted unlocking.

[0005] To control the actuator and / or the parking lock mechanism, a parking lock operating device is typically arranged in the passenger compartment of the motor vehicle. In principle, various mechanical, electro-hydraulic, and electromechanical parking lock operating devices are known. Mechanical parking lock operating devices for actuating the vehicle parking lock device comprise, for example, a Bowden cable between the selector lever located in the passenger compartment and the parking lock mechanism. In modern motor vehicles, the transmission of switching commands from the parking lock operating device is generally carried out exclusively by means of electrical or electronic signals. In other words, with regard to a vehicle parking lock device, this means that the vehicle parking lock device is also generally actuated electrically, electro-hydraulicly, and / or hydraulically.In addition to manual operation of the parking lock operating device by a user, the vehicle parking lock device can also be operated automatically under certain circumstances, for example in the case of the parking lock being automatically engaged when the ignition key is removed or the vehicle is left behind.

[0006] To generate the necessary force and travel to unlock the locking device, a sufficiently large actuator, such as a solenoid, is typically required. Such a parking lock device is known, for example, from DE 199 20 095 C1.

[0007] Further relevant prior art is known from DE 10 2020 207 430 A1, DE 10 2014 209 253 A1, US 2010 / 0 248 884 A1 and DE 10 2009 021 891 A1.

[0008] It is therefore the object of the invention to provide a vehicle parking lock device that has a compact design and can provide a large adjustment range and / or a high force for actuating the parking lock. This object is achieved by a vehicle parking lock device according to claim 1 or 2, comprising an actuator and a parking lock mechanism, wherein the actuator interacts with the parking lock mechanism in such a way that the parking lock mechanism can be transferred by the actuator into a parking lock locking position and a parking lock release position, wherein the actuator has a first linear actuator element and a second linear actuator element which are coupled to one another in such a way that the linear offset of the actuator can be provided by the linear offset of the first linear actuator element and the linear offset of the second linear actuator element.

[0009] This provides the advantage of better control of both the actuator stroke and its force exerted on the parking lock mechanism, which particularly favors more precise control of the vehicle parking lock device while minimizing the actuator's installation space. Furthermore, by dividing the actuator into two linear actuator elements, the available installation space can be utilized flexibly and optimally. Furthermore, dividing the actuator into the two linear actuator elements also provides a certain degree of redundancy should one of the linear actuator elements fail.

[0010] In particular, the actuator can thus not only be actuated directly with a stroke (complete force, complete travel) at the actuator end, but the actuation can be divided into several individual steps via the linear actuator elements, which enables better control and utilization of installation space.

[0011] The individual technical elements of the vehicle parking lock device according to the invention are explained in more detail below. Following this, particularly preferred embodiments and further developments of the vehicle parking lock device according to the invention are described.

[0012] A vehicle parking lock device according to the invention typically comprises an actuator that acts on a parking lock mechanism for the purpose of locking the vehicle parking lock device, which then creates a positive locking within the vehicle drive train to block the driven vehicle wheels. The actuator can have at least two linear actuator elements. A linear actuator element converts hydraulic and / or pneumatic and / or electrical energy into mechanical kinetic energy, which is then fed to the parking lock mechanism.

[0013] A linear actuator element can be coupled to an actuator mechanism. The actuator mechanism converts the movement of the linear actuator element acting on it at its input into an output movement of the actuator mechanism. In this sense, an actuator mechanism can also be referred to as a motion converter. A linear actuator element can, in particular, be designed as an electromotive, electrohydraulic, electromagnetic, or hydraulic linear actuator element. The actuator mechanism can preferably be designed as a linear actuator, which converts a rotary movement of the actuator drive into a translatory movement. In this context, it is particularly preferred to design the actuator mechanism as a spindle drive actuator.

[0014] The parking lock mechanism converts the movement applied by the actuator into a movement acting on the vehicle's drivetrain for the purpose of positively locking and blocking the driven vehicle wheels. The parking lock mechanism can, in particular, comprise a parking lock pivot lever mechanism. In a parking lock pivot lever mechanism, the movement applied by the actuator is converted into a movement acting on the vehicle's drivetrain for the purpose of positively locking and blocking the driven vehicle wheels by means of a parking lock pawl pivotably mounted in the parking lock pivot lever mechanism. The parking lock pawl can be pivoted between its locked position and its released position about a parking lock pawl bearing.

[0015] In order to avoid operating errors, a parking lock pivot lever mechanism can have a preload spring mechanism in which a preload spring acts on the parking lock pivot lever mechanism when a locking situation occurs in order to bring about a secured positive locking or secured unlocking of the parking lock mechanism.

[0016] A preload spring guide can advantageously guide the preload spring of the preload spring mechanism along a defined spring travel. This ensures a defined behavior of the spring force and the spring force curve along the guided spring travel of the preload spring.

[0017] The preload spring is typically preloaded to move the parking lock lever mechanism into a predefined state under spring force. The preload spring typically acts directly or indirectly on the parking lock pawl to pivot it from its locked position to or into its locked position. This allows, for example, a "normally close" operating mode of the parking lock lever mechanism to be implemented, in which, after a safety device is removed, the parking lock pawl of the parking lock lever mechanism is pivoted into its locked position under spring force.

[0018] The parking lock pawl is used to create a positive, releasable connection between the parking lock mechanism and the vehicle drivetrain. In its locked position, the parking lock pawl engages positively with the vehicle drivetrain, preventing rotation of the driven vehicle wheels. In its released position, the parking lock pawl is spaced apart from the vehicle drivetrain, i.e., not in positive engagement with it, allowing rotation of the driven vehicle wheels. For this purpose, a corresponding parking lock gear is formed within the vehicle drivetrain, for example, into which the parking lock pawl engages positively to secure the vehicle against unintentional rolling.

[0019] The actuator can be controlled in such a way that the first and second linear actuator elements are actuated sequentially. It is also possible to control both linear actuator elements simultaneously, so that they are actuated simultaneously.

[0020] According to an advantageous embodiment of the invention, it can be provided that the first linear actuator element is selected from the group of electromechanical linear actuators, electromagnetic linear actuators, hydraulic linear actuators, and / or pneumatic linear actuators. According to a further preferred development of the invention, it can also be provided that the second linear actuator element is selected from the group of electromechanical linear actuators, electromagnetic linear actuators, hydraulic linear actuators, and / or pneumatic linear actuators.

[0021] An electromechanical linear actuator can, for example, be designed as a spindle linear drive. This type of linear actuator uses a rotating spindle and a nut to generate the linear movement. The rotation of the spindle, which can be achieved by an electric motor, for example, moves the nut along the spindle, thus generating a linear movement. It would also be conceivable to use linear motor drives, which use a linear motor to generate the linear movement. Furthermore, it would also be possible to use piezo linear drives, which use piezoelectric materials to generate a linear movement by applying a voltage to the piezoelectric material.

[0022] An electromagnetic linear actuator can, for example, be a lifting magnet.

[0023] A hydraulic linear actuator can, for example, be designed as a piston-cylinder linear actuator. This type of linear actuator uses a piston that is moved by a hydraulic fluid in a cylinder to generate the linear movement. The hydraulic fluid is pumped into the cylinder by a hydraulic motor or hydraulic pump. A hydraulic linear actuator can also be configured as a telescopic cylinder linear actuator, which consists of several nested cylinders that are moved by a hydraulic fluid. Each cylinder has its own piston that is moved by the hydraulic fluid to generate the linear movement. It would also be possible to design the hydraulic linear actuator as a double-acting cylinder linear actuator, in which one cylinder is designed with two pistons, both moved by a hydraulic fluid.The movement of the pistons in both directions creates the linear movement.

[0024] Furthermore, according to a similarly advantageous embodiment of the invention, it can be provided that the first linear actuator element and the second linear actuator element are selected from different groups of linear actuators. The advantageous effect of this embodiment is based on the fact that it allows the advantages of different types of linear actuators to be combined.

[0025] According to another particularly preferred embodiment of the invention, the parking lock mechanism can be provided with a pivotably mounted lever, at one distal end of which a parking lock pawl is formed, which can be positively coupled to a corresponding parking lock gear, and at the other distal end of which the actuator rests. This allows for a particularly secure and mechanically simple parking lock mechanism. Furthermore, the length of the lever allows for the force and travel ratios to be optimally matched to the actuator.

[0026] For example, it would be conceivable that the lever to be actuated by the actuator is designed to be sufficiently long so that low actuating forces result, but a single stroke of the actuator (linear actuator, lifting magnet) would not be sufficient to release the parking lock.

[0027] Furthermore, the invention is also characterized in that the first linear actuator element is a solenoid and the second linear actuator element is a hydraulic cylinder. In one embodiment of the invention, it can also be provided, or in a second alternative according to the invention it is provided, that the first linear actuator element is coupled to a linearly displaceable actuating plunger that engages with the hydraulic cylinder. It can also be advantageous to further develop the invention or to provide in a first embodiment according to the invention that the hydraulic cylinder has a first hydraulic chamber and a second hydraulic chamber that are connected to one another via a check valve. According to a further preferred embodiment of the subject matter of the invention, it can be provided that the first hydraulic chamber and the second hydraulic chamber are hydraulically connected to one another by means of an orifice.

[0028] This allows the hydraulic cylinder to operate like a piston pump, driven by the stroke of the solenoid. This makes it possible to achieve the entire required linear displacement of the actuator through several short individual strokes, which are "added up" accordingly by the hydraulic cylinder.

[0029] For example, it is then possible and also provided according to the second embodiment of the invention to control the actuator in such a way that by actuating the first linear actuator element multiple times, the hydraulic cylinder then has a linear offset that is greater than the linear offset of the first linear actuator element.

[0030] The hydraulic cylinder can also be used to drive a comparatively small first linear actuator element, such as a solenoid, which can provide a correspondingly small stroke and / or actuation force. Thus, the parking lock mechanism is not actuated directly with a single stroke (complete force, complete travel) by the actuator, but rather the actuation is divided into several individual steps, in particular by the "pumping" of the first linear actuator element in conjunction with the hydraulic cylinder.

[0031] Finally, the invention can also be advantageously designed such that the actuating plunger is spring-loaded by means of a preload spring.

[0032] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0033] It shows: Fig. 1 a vehicle parking lock device in a parking lock locking position in a schematic representation, Fig. 2 a vehicle parking lock device in a parking lock release position in a schematic representation, Fig. 3 an actuator of the vehicle parking lock device in different operating states in a schematic representation each.

[0034] The Fig. 1 shows a vehicle parking lock device 1 comprising an actuator 2 and a parking lock mechanism 3, wherein the actuator 2 interacts with the parking lock mechanism 3 such that the parking lock mechanism 3 can be transferred by the actuator 2 into a parking lock locking position and a parking lock release position. Fig. 1 shows the vehicle parking lock device 1 in its parking lock locking position and the Fig. 2 in its parking lock release position.

[0035] The Fig. 1-2 further show that the parking lock mechanism 3 has a pivotably mounted lever 9, at one distal end 12 of which a parking lock pawl 10 is formed, which can be positively coupled to a corresponding parking lock gear 11 and at the other distal end 13 of which the actuator 2 rests.

[0036] The actuator 2 has a first linear actuator element 4 and a second linear actuator element 5, which are coupled to one another in such a way that the linear offset 6 of the actuator 2 can be provided by the linear offset 7 of the first linear actuator element 4 and the linear offset 8 of the second linear actuator element 5. In the embodiment shown, the Fig. 1-2, the first linear actuator element 4 is a lifting magnet 14 and the second linear actuator element 5 is a hydraulic cylinder 15.

[0037] Here, the first linear actuator element 4 is coupled to a linearly displaceable actuating plunger 16, which engages the hydraulic cylinder 15. The actuating plunger 16 is spring-loaded by a preload spring 21. The hydraulic cylinder 15 has a first hydraulic chamber 17 and a second hydraulic chamber 18, which are connected to each other via a check valve 19. Furthermore, the first hydraulic chamber 17 and the second hydraulic chamber 18 are hydraulically connected to each other via an orifice 20. The second hydraulic chamber 18 serves as a reservoir for hydraulic medium and can be connected to a corresponding hydraulic system via the hydraulic connection 22.

[0038] In other words, a hydraulic cylinder 15 is provided between the actuating tappet 16 of the actuator 2 and the lever 9 to be actuated, which, analogous to hydraulic tappets in the combustion engine (hydraulic valve clearance compensation element), has a check valve 19, an orifice 20 (e.g. annular gap) and a preload spring 21.

[0039] If the lever 9 is engaged (e.g., spring-loaded) and is to be disengaged by the actuator 2 under load, the hydraulic cylinder 15 is compressed to such an extent that it is positioned without play between the retracted actuator 2 and the distal end 13 of the lever 9 by the preload spring 21. Alternatively (or in addition to the preload spring), both ends of the hydraulic cylinder 15 can also be connected to the corresponding connecting element in tension to achieve zero play.

[0040] To actuate the parking lock mechanism 3, the solenoid 14 is now extended. The check valve 19 prevents hydraulic fluid from escaping from the first hydraulic chamber 17, so the hydraulic cylinder 15 rigidly transmits the actuation stroke to the distal end 13 of the lever 9. A slight travel loss occurs due to the orifice 20 (annular gap), through which a small amount of hydraulic fluid can escape.

[0041] During the return stroke of the lifting magnet 14, the preload spring 21 (and / or the tensile connection of the components) creates a suction effect in the first hydraulic chamber 17, which opens the check valve 19 and allows hydraulic medium to flow into the first hydraulic chamber 17. The hydraulic cylinder 15 expands instead of retracting the lever 9. Even during this return stroke, hydraulic medium can be pushed back through the orifice 20 by spring preloading the lever 9. The elements are designed such that at least 50% of the individual stroke, preferably at least 75% of the individual stroke, and particularly preferably at least 95% of the individual stroke is retained for each individual stroke until another individual stroke of the lifting magnet 14 is executed. Thus, by means of several short individual strokes following one another in quick succession, a large total stroke can be achieved, which is sufficient to fully actuate the parking lock mechanism with great force.

[0042] If no further individual strokes occur after the actuation has been completed, the hydraulic cylinder 15 is compressed again by the (spring) preload of the lever 9 and the pressure reduction through the aperture 20, so that the parking lock mechanism 3 can engage again without the actuator 2 preventing this.

[0043] In this way, it is possible to apply a large force over a large distance with an actuator 2, which can only provide small forces over small strokes (force increase via lever ratio / transmission ratios and large distances by adding up several small distances).

[0044] The actuator 2 is thus designed and controlled in such a way that by repeatedly actuating the first linear actuator element 4, the hydraulic cylinder 15 has a linear offset 8 which is greater than the linear offset 7 of the first linear actuator element 4. This can also be clearly seen from the Fig. 3. Figure a of the Fig. Figure 3 shows the actuator 2 in its maximum possible axial displacement 6. This maximum displacement 6 in Figure a is caused by multiple actuation of the first linear actuator element 4, which can also be referred to as "pumping." In this case, the displacement 7 of the first linear actuator element 4 is essentially constant. This is shown in Figures b and c of the Fig. 3. It can be clearly seen how, with increasing number of actuations (from figure b to c and to a), the hydraulic cylinder 15 is extended further and further linearly until it finally reaches its maximum displacement 6 shown in figure a.

[0045] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority.

Claims

[1] Vehicle parking lock device (1) comprising an actuator (2) and a parking lock mechanism (3), wherein the actuator (2) interacts with the parking lock mechanism (3) in such a way that the parking lock mechanism (3) can be transferred by the actuator (2) into a parking lock locking position and a parking lock release position, wherein the actuator (2) comprises a first linear actuator element (4) and a second linear actuator element (5) which are coupled to one another in such a way that the linear offset (6) of the actuator (2) can be provided by the linear offset (7) of the first linear actuator element (4) and the linear offset (8) of the second linear actuator element (5), characterized by , that the first linear actuator element (4) is a lifting magnet (14) and the second linear actuator element (5) is a hydraulic cylinder (15), and the hydraulic cylinder (15) has a first hydraulic chamber (17) and a second hydraulic chamber (18) which are connected to one another via a check valve (19). [2] Vehicle parking lock device (1) comprising an actuator (2) and a parking lock mechanism (3), wherein the actuator (2) interacts with the parking lock mechanism (3) in such a way that the parking lock mechanism (3) can be transferred by the actuator (2) into a parking lock locking position and a parking lock release position, wherein the actuator (2) comprises a first linear actuator element (4) and a second linear actuator element (5) which are coupled to one another in such a way that the linear offset (6) of the actuator (2) can be provided by the linear offset (7) of the first linear actuator element (4) and the linear offset (8) of the second linear actuator element (5), characterized by , that the first linear actuator element (4) is a lifting magnet (14) and the second linear actuator element (5) is a hydraulic cylinder (15), the first linear actuator element (4) is coupled to a linearly displaceable actuating plunger (16) which engages in the hydraulic cylinder (15), and the actuator (2) is controlled such that by multiple actuation of the first linear actuator element (4) the hydraulic cylinder (15) has a linear offset (8) which is greater than the linear offset (7) of the first linear actuator element (4). [3] Vehicle parking lock device (1) according to claim 1 or 2, characterized by that the first linear actuator element (4) is selected from the group of electromechanical linear actuators, electromagnetic linear actuators, hydraulic linear actuators and / or pneumatic linear actuators. [4] Vehicle parking lock device (1) according to at least one of claims 1 to 3, characterized bythat the second linear actuator element (5) is selected from the group of electromechanical linear actuators, electromagnetic linear actuators, hydraulic linear actuators and / or pneumatic linear actuators. [5] Vehicle parking lock device (1) according to claim 3 or 4, characterized by that the first linear actuator element (4) and the second linear actuator element (5) are selected from different groups of linear actuators. [6] Vehicle parking lock device (1) according to one of the preceding claims, characterized by that the parking lock mechanism (3) has a pivotably mounted lever (9), at one distal end (12) of which a parking lock pawl (10) is formed, which can be positively coupled to a corresponding parking lock wheel (11) and at the other distal end (13) of which the actuator (2) rests. [7] Vehicle parking lock device (1) according to claim 1 or according to claim 1 and one of claims 3 to 6, characterized bythat the first linear actuator element (4) is coupled to a linearly displaceable actuating plunger (16) which engages in the hydraulic cylinder (15). [8] Vehicle parking lock device (1) according to claim 2, characterized by that the hydraulic cylinder (15) has a first hydraulic chamber (17) and a second hydraulic chamber (18) which are connected to one another via a check valve (19). [9] Vehicle parking lock device (1) according to claim 1 or according to claim 1 and one of claims 3 to 7, characterized by that the first hydraulic chamber (17) and the second hydraulic chamber (18) are hydraulically connected to one another by means of an orifice (20). [10] Vehicle parking lock device (1) according to one of claims 7 or 9, when dependent on claim 7, characterized by that the actuating plunger (16) is spring-loaded by means of a preload spring (21). [11] Vehicle parking lock device (1) according to one of claims 1, 7 or 9, characterized by that the actuator (2) is controlled such that by multiple actuation of the first linear actuator element (4) the hydraulic cylinder (15) has a linear offset (8) which is greater than the linear offset (7) of the first linear actuator element (4).

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