Actuator for a parking lock

Description

[0001] The invention relates to an actuating actuator for a parking lock, comprising at least the following components: an axial drive means for transmitting an axial force; an actuating element with an actuating axis, which is axially movable from a first position to a second position by means of the axial force of the axial drive means; a stopper element; a stopper component corresponding to the stopper element; and a holding element, which is movable between a released position and a locked position, wherein, while the actuating element is in the deflected position, the stopper element and the stopper component are fixed to one another with the holding element in the locked position. The actuating actuator is characterized in that a lifting magnet with a coil and a lifting piston axially movable by means of a magnetic force generated by the coil is also provided. wherein the holding element is fixedly connected to the axially movable reciprocating piston. The invention further relates to a parking lock for a parking lock device of a transmission, a parking lock device having such a parking lock, a transmission having such a parking lock device for a drive train, a drive train having such a transmission, and a motor vehicle having such a drive train.

[0002] Parking locks are known, for example, from DE 10 2018 115 548 A1. Motor vehicles with parking locks, such as so-called by-wire parking locks, in a normally locked configuration, i.e., with the chassis locked in the event of a system failure, must be actively held open while driving, constantly consuming energy. As motor vehicles become more electrified, the energy requirements of all components are relevant to the achievable range, and therefore, energy-efficient operation of the parking lock while the vehicle is moving must be strived for.

[0003] DE 10 2013 213 678 A1 discloses an actuating device for a parking lock unit, in which a low holding current is required for an electromagnet to lock the parking lock unit in the open operating state. Furthermore, unintentional opening of the parking lock unit can be prevented by not switching the electromagnet.

[0004] A device of this type is also known from EP 2 458 226 A1. Based on this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. The features of the invention are set forth in independent claim 1, with advantageous embodiments being presented in the dependent claims.

[0005] In the following, reference is made to the specified actuation axis when, without explicit indication to the contrary, the axial direction, radial direction, or rotational direction and corresponding terms are used. Ordinal numbers used in the preceding and following descriptions serve only to clearly distinguish them and do not reflect the order or ranking of the designated components. An ordinal number greater than one does not necessarily imply that another such component must be present.

[0006] The actuating actuator proposed here comprises an axial drive means, for example, an electric actuator with a spindle drive or a slave piston of a fluidic, i.e., pneumatic or hydraulic, actuation system. By means of the axial drive means, an axial force can be exerted along an actuation axis and transmitted to the actuating element. The actuating element is, for example, a plunger or rod, an axially movable spindle, or an axially movable spindle nut. The actuating element is configured to transmit the axial force of the axial drive means to a locking mechanism. The actuating element is movably guided along an actuation axis and can be axially moved from a (normal) first position to a (deflected) second position by means of the axial drive means.In a preferred embodiment, the actuating element can be returned to the normal position exclusively passively by a (storage) force antagonistic to the axial force of the axial drive means. Alternatively, the actuating element can be returned from the deflected position to the normal position additionally or alternatively by the axial drive means. The axial force of the axial drive means, which can be transmitted by means of the actuating element, is designed to overcome an antagonistic force of a first energy storage element and / or a locking mechanism, whereby a (normally locking) locking mechanism can preferably be transferred from the locked state to the free state. Alternatively, conversely, a (normally open) locking mechanism can be transferred from the free state to the locked state. Such a (first) energy storage element is designed, for example, as a helical compression spring, disc spring, magnetic spring, or gas spring.Preferably, the first energy storage element is designed as a helical compression spring with a spring axis parallel or coaxial to the actuating axis.

[0007] In order to be able to maintain the respective state of the locking mechanism with low energy consumption, a stopper element is proposed which is designed to interact with a corresponding stopper component in such a way that a frictional and / or positive connection is formed. In one embodiment, the stopper element is fixed to the axial drive means or to the actuating element, and the stopper component is fixed axially to a counterbearing of the axial drive means, at least during the deflected position of the actuating element. Alternatively, this is implemented the other way around. In one embodiment, the stopper element is formed by at least one tab with a contact point, wherein the contact point can be brought into contact with the corresponding stopper component to apply the holding force.In one embodiment, a (preferably switchable) magnetic (stopper) force is additionally generated, with which the stopping force resulting from the positive locking and / or frictional engagement is supported. In one embodiment, the stopping force provides a force that supplements the axial force, and by means of or while maintaining the stopping force, the (required) axial force to overcome the above-mentioned antagonistic force can be reduced, thus reducing the energy consumption of the actuating actuator. In another embodiment, the stopping force (without the cooperation of the holding element) is negligibly small, with preferably no magnetic force being maintained between the stopping element and the corresponding stopping component.

[0008] In a preferred embodiment, the corresponding stopper component (or stopper element) (fixed in the deflected position) is axially fixed and thus fixed relative to the counterbearing of the axial drive means (e.g., the fluid cylinder of a slave piston). In an alternative embodiment, the corresponding stopper component is movable with the axial drive means or with the actuating element and is fixed in the second position by means of a stop.

[0009] To ensure that the parking lock assumes its normal state (be it normally locked or normally open), the stop force must be lower than the antagonistic force to the axial force of the axial drive mechanism, whereby the antagonistic force is transferable to transfer the actuating element from the deflected position to the normal position. In a normally locking configuration of the parking lock, the axial force actively transfers the parking lock from the (normal) locked state to the (deviating) free state, whereby the normal position of the actuating element corresponds to the locked state (parking position) and the deflected position to the free state (drive position). In the normal position, no axial force needs to be exerted, so that no external energy absorption is required by the axial drive mechanism.The normal position of the actuating element is preferably secured by the stored force of a first energy storage element. An axial force is required to transfer the actuating element into the deflected position, which therefore requires external energy absorption.

[0010] To ensure that the stopper force is sufficient to hold the actuating element in the deflected position (for example, the drive position for a parking lock in a normal-locking configuration), it is proposed here that a retaining element is also provided. The retaining element is movable between a locking position and a released position. By means of the retaining element, in the locking position, the state of the corresponding stopper component and the stopper element is fixed in the state that corresponds to the deflected position of the actuating element. Thus, the retaining element transmits such a force that the resulting stopper force is sufficient to overcome the force antagonistic to the axial force of the axial drive means.In the case of a purely frictional engagement between the stopper element and the corresponding stopper component, an additional holding force is preferably applied by the holding element to increase the frictional adhesion, particularly preferably by means of a link, for example a ramp shape on the holding element and / or on the stopper element. At least a positive engagement is formed between the holding element and the stopper element in such a way that the stopper element is prevented from making an evasive movement. The possibility of an evasive movement (without the action of the holding element) is intended, so that the connection between the stopper element and the corresponding stopper component releases automatically as soon as the holding element is in the released position and the axial force of the axial drive means is sufficiently low, preferably minimal (for example zero or negative).

[0011] In one embodiment, the (corresponding) stopper component is formed by means of an undercut (relative to the actuation axis), for example by means of a groove. In one embodiment, the contact point of the stopper element is an elevation, preferably at a tip of the stopper element designed as a tab, which can be countersunk axially behind the undercut, for example a groove, to form a positive connection. In one embodiment, the stopper element is formed by at least one spring tab with an axial main extension and a radial spring direction. In a preferred embodiment, an arrangement of sub-elements of the stopper element and the stopper component, and preferably of the holding element, is formed that is symmetrical to the actuation axis in order to avoid tilting forces transverse to the actuation axis, particularly preferably a ring-like arrangement.For example, the stopper element comprises a plurality of (preferably spring) tabs, and the corresponding stopper component comprises a complementary receptacle, for example, a circumferential counter surface or undercut (e.g., a groove). The retaining element is then preferably also complementary to the plurality of tabs or ring-shaped.

[0012] The at least one spring tab is made, for example, from a metallic material, such as a spring sheet. In another embodiment, the spring tab is made from a plastic. In a preferred embodiment, the at least one spring tab is integrally enclosed by the stopper element.

[0013] According to the present invention, a lifting magnet is provided with a coil and a lifting piston that can be moved axially by means of a magnetic force generated by the coil, wherein the holding element is fixedly connected to the axially movable lifting piston. Thus, by energizing the coil, such a magnetic field can be induced with a magnetic force (which can be switched off) resulting on the holding element, so that when the magnetic force is applied, the holding element is moved from the locked position to the released position. This creates an electronic switchability for fixing the actuating element in the second position. In one embodiment, the holding element and the lifting piston are formed integrally with one another.

[0014] In one embodiment, it is proposed that the two surfaces of the reciprocating piston and the inner return path are aligned with each other in such a way that when the coil is energized, the reciprocating piston is moved in the direction of the inner return path, so that the axial gap is reduced.

[0015] The lifting magnet is designed such that the coil is held in place and positioned in an insulating manner by means of a magnetically non-conductive material (e.g., plastic), preferably by the inner yoke. The yokes are preferably made of a ferromagnetic material. The inner yoke is arranged radially closer to the actuating axis than the outer yoke. In a preferred embodiment, the coil is arranged radially circumferentially around the actuating axis and completely enclosed by the lifting magnet and the lifting piston. In this case, the holding element is preferably also circumferentially designed, for example, in a ring shape, and is guided coaxially to the coil and the yokes. The stopper component (or stopper element) fixed in the second position of the actuating element is preferably fixed to the counterbearing of the axial drive means via the outer yoke.

[0016] Both return pins together form a U-shaped opening in which the reciprocating piston is located. The reciprocating piston is arranged between the inner return pin and the outer return pin in such a way that an axial movement is possible within the axial extent of one of the return pins, namely between the locked position and the released position. The reciprocating piston is guided in its axial movement by one of the return pins (preferably by the outer return pin) and secured against jamming and / or loss.

[0017] Due to the axial movement of the piston, an axial gap is created between the piston and one of the return ports (preferably the inner return port) in one of the positions. In a preferred embodiment, the axial gap is present at least in the locking position.

[0018] In one embodiment, the axial gap is closed in the (maximum) other (then, for example, released) position. The lifting magnet is then configured, for example, such that the lifting piston can be brought into contact with the inner yoke, i.e., the magnetic force is set so large that the axial gap approaches zero. It should be noted that in an alternative embodiment, an axial gap exists between the lifting piston and the outer yoke, and the two components can be brought into contact. Furthermore, it should be noted that in one embodiment, an axial gap is permanently present.

[0019] The axial gap is such a gap between the reciprocating piston and the corresponding return path, which includes an axial vector component so that an axial reciprocating movement of the reciprocating piston (and thus of the holding element) is possible.

[0020] It is further proposed in an advantageous embodiment of the actuating actuator that the gap normal of the axial gap is inclined to the actuating axis or is aligned purely axially.

[0021] The axial gap between the return paths and the reciprocating piston is such that, depending on the design of the reciprocating piston and the complementary return path, the gap is a purely axially aligned axial gap, i.e. parallel to the actuation axis. In one embodiment, the axial gap has a radial vector component, whereby a gap normal of the axial gap is oriented at an angle to the actuation axis, i.e. the two surfaces that form the axial gap are conically guided with respect to the actuation axis. In one embodiment, the axial gap comprises a plurality of sections with gap normals that are aligned differently from one another; for example, in one section the gap normal is aligned purely radially.

[0022] In a preferred embodiment, in which a circumferential axial gap is formed (for example, an annular holding element and / or complementary return path), a (preferably rotationally symmetrical) conical shape is assumed. The geometry of the respective ends of the complementary components (holding element and return path) has a direct influence on the magnetic force. Depending on the orientation of the magnetic field lines within the return paths and the immersion of the component geometry of the reciprocating piston into the lifting magnet, a different magnetic force or a different axial vector component of the magnetic force results. If the axial stroke of the reciprocating piston is relatively small, for example less than or equal to 0.5 mm [five-tenths of a millimeter], a purely axial alignment of the gap normal is advantageous for a high magnetic force or low energy consumption and / or size of the coil.Conversely, for a relatively large axial stroke of the reciprocating piston, for example greater than 0.6 mm [six tenths of a millimeter], an inclined, particularly preferably conical, alignment of the gap normal is advantageous for a large magnetic force or a low energy consumption and / or size of the coil over the entire axial stroke (and especially at the maximum of the gap extension of the axial gap) of the reciprocating piston.

[0023] It is further proposed in an advantageous embodiment of the actuating actuator that the lifting magnet further comprises a second energy storage element, from which a holding force antagonistic to the magnetic force is held on the lifting piston, wherein the magnetic force is preferably a tensile force.

[0024] Here, it is proposed that the lifting magnet comprise a second energy storage element. This second energy storage element is designed such that it applies a holding force to the lifting piston counter to the magnetic force of the lifting magnet. Thus, by means of the second energy storage element, the lifting piston (i.e. the holding element) is passively held in the locking position and can only be actively transferred to the released position by energizing the coil of the lifting magnet. For a parking lock in a normally locking configuration, the actuating actuator is designed such that when electrical energy is supplied to the coil, the holding element moves from its locking position to its released position, thus transferring the parking lock from a (passively secured) free state to the (normal, i.e. passive) locking state. For a parking lock in a normally open configuration, the reverse applies.

[0025] In this embodiment, the coil inducing the magnetic force is designed such that the magnetic force (with respect to the reciprocating piston) is a tensile force. Due to the tensile force, the active axial movement of the reciprocating piston (resulting from the energization of the coil) is directed towards the coil. The second energy storage element is dimensioned such that the minimum (active) magnetic force is greater than the (correspondingly minimum or maximum) holding force. Only when the magnetic force is switched off (i.e., zero or sufficiently low) can the holding element return to the released position. If the stopper element and the stopper component are in a state corresponding to the deflected position of the actuating element, the actuating element is then held in the second position without external energy absorption (i.e., passively).As soon as the holding element is moved into the released position by the magnetic force, the stopper element and the stopper component separate from each other unless a sufficient (active) axial force is applied by the axial drive means. In the event of a locking engagement (groove and tab), the stopper element's fixation from the stopper component is removed, and the stopper element slides out of the stopper component due to the storage force (of a first energy storage element) that is antagonistic to the axial force.

[0026] The second energy storage element is designed, for example, as a helical compression spring, disc spring, magnetic spring, or gas spring. The second energy storage element is preferably designed as a helical compression spring with a spring axis parallel or coaxial with the actuation axis. For example, the diameter of the second energy storage element is limited by the diameter of the actuation actuator and / or by the wall thickness of the holding element, so that the energy storage element preferably acts radially circumferentially on the holding element. In another embodiment, the second energy storage element comprises a plurality of separate springs (preferably helical compression springs) which are arranged circumferentially and each act on the holding element at a point.

[0027] A further embodiment is proposed, according to which the coil is accommodated by the internal return path, the internal return path is arranged coaxially with the actuating axis, and the actuating element and / or a slave piston encompassed by the axial drive means at least partially axially overlap. This means that the internal return path and the actuating element or the slave piston are at least partially nested.

[0028] According to a further development of the invention, the outer return path is firmly connected to the inner return path via a press fit. This allows for particularly simple assembly and construction of the actuator.

[0029] According to a further aspect of the present invention, a parking lock for a parking lock device of a transmission is proposed, comprising at least the following components: a locking mechanism for locking a locking gear in a torque flow, wherein, in use, the locking mechanism blocks the locking gear in a locking state and releases the locking gear in a free state; and an actuating actuator according to any one of claims 1-7, wherein, in the deflected position of the actuating element, the locking mechanism is moved out of the locking state, and wherein the normal position of the actuating element corresponds to the locking state of the locking mechanism.

[0030] The parking lock proposed here is configured such that the locking mechanism blocks the locking gear in a locking state, and the locking gear is only released from the locking mechanism in a free state. In the free state, the locking gear is freely rotatable, for example, when used in a motor vehicle transmission, and the motor vehicle can then roll. It should be noted that the locking gear is integrated into a torque flow of a transmission. If the actuating element is moved into the locking state, the torque flow is blocked by means of the locking mechanism, and the transmission is blocked. In the locking state of the locking gear, when used in such a transmission, the motor vehicle cannot roll. The parking lock comprises an actuating actuator with an actuating element that is connected to the locking mechanism.The actuating element is connected to the locking mechanism in such a way that, when the actuating element is in the deflected position, the locking mechanism is in a state that deviates from the normal state. With a parking lock in a normal-locking configuration, the free state can be actively brought about by means of the actuating actuator. However, the state that deviates from the normal state does not have to be maintained actively (i.e. by external energy absorption), but is held passively by the stopper element and the stopper component with the support of the holding element. When the coil of the lifting magnet is energized, the stopper element is separated from the stopper component and thus (preferably passively) the actuating element is moved from the deflected position to the normal position. The locking mechanism is thus free to return from the deviating state to the normal state.

[0031] It is further proposed in an advantageous embodiment of the parking lock that an unlocking element is provided which is movable between a normal position and an unlocking position, wherein in the unlocking position the free state of the locking mechanism is maintained and in the normal position the normal-locking function of the parking lock is ensured.

[0032] The parking lock is actuated electrically and / or fluidically, for example pneumatically or hydraulically, and in the event of an electronics failure or a drop in fluid pressure or fluid volume, the locking mechanism is transferred to the normal (preferably locking) state. With a parking lock in a normal-locking configuration, the locking wheel is then blocked. In order to deactivate this during a passive state (for example in a motor vehicle during production, transport, or in a workshop), it is proposed here that an unlocking element be provided which is movable between two positions (for example designed as a pivoting lever mounted about a pivot axis). The unlocking element is designed such that, with the unlocking element in the unlocking position, the deviating (for example free) state of the locking mechanism can be maintained without external energy absorption.This passive state ensures that, when the (normally locking) parking lock is engaged in a motor vehicle's transmission, the vehicle can continue to roll. To cancel this passive state, which is undesirable during operation of the parking lock, the release element can be deactivated again (preferably repeatedly), i.e., returned to the normal position.

[0033] In a preferred embodiment, a locking element is additionally provided. The locking element is configured to hold the unlocking element in the unlocking position. If the locking element does not hold the unlocking element in the unlocking position, the free state of the locking mechanism cannot be (passively) maintained by the unlocking element. This means that the unlocking position or the deviating (and thus, in the case of a parking lock in a normal-locking configuration, the free) state of the locking mechanism can only be (permanently) adjusted through the interaction of the unlocking element and the locking element.

[0034] According to a further aspect of the present invention, a parking lock device is proposed, comprising a locking gear for arrangement in a lockable torque flow and a parking lock according to claim 8 or claim 9, wherein the locking gear is lockable by means of the locking mechanism.

[0035] The parking lock device proposed here comprises a parking lock and a corresponding locking gear. The locking gear is integrated into a lockable torque flow of a drive train of a motor vehicle, preferably a transmission, and can be locked as described above.

[0036] In one embodiment, the parking lock and the locking gear form a structural unit. Such a structural unit can be delivered for installation as a coherent component and can be mounted at the intended installation location, for example in a motor vehicle, without the need to disassemble this structural unit. In one embodiment, the locking mechanism, and in one embodiment also the locking gear, are a structural unit, while the actuating actuator is formed separately, wherein in one embodiment the actuating actuator forms a separate further structural unit. When installed in a drive train, for example of a motor vehicle, the locking gear is arranged in such a way that at least one of the consumers is prevented from transmitting or absorbing torque when the locking mechanism is in the locking state, i.e. the locking gear is blocked.

[0037] According to a further aspect of the present invention, a transmission for a drive train is proposed, comprising at least the following components: a parking lock device according to claim 10; a torque transmission gear comprising the locking gear; and a gear housing surrounding a gear chamber, wherein the locking mechanism of the parking lock, preferably completely, particularly preferably the entire parking lock device, is arranged in the transmission chamber.

[0038] The transmission, for example, an automatic transmission for a motor vehicle drivetrain, includes the locking gear. For example, the locking gear forms a spur gear of a torque transmission designed as a shiftable transmission. The transmission has a torque input, for example, one or more transmission input shafts, and a torque output, for example, one or more transmission output shafts. In the transmission, the torque is redirected, reduced, increased, and / or distributed according to the required torque (as a differential).

[0039] In one embodiment, the transmission includes a clutch, for example a friction clutch or a dog clutch, in the torque flow. The torque input is located on the drive engine side, and the torque output is located on the consumer side. However, the torque direction is also possible in the opposite direction, from a consumer (during recuperation) to a drive engine or a generator. Furthermore, in an advantageous embodiment of the transmission, it is proposed that the parking lock as a whole, or solely the locking mechanism, be integrated into a transmission chamber formed by a transmission housing.

[0040] According to a further aspect of the present invention, a drive train is proposed, comprising at least the following components: at least one drive machine for outputting a torque; at least one consumer for receiving a torque; and a transmission according to claim 11, wherein the at least one drive motor and the at least one consumer are connected to one another in a torque-transmitting manner by means of the transmission, wherein a torque transmission between the drive motor and the at least one consumer is prevented by means of the parking lock device in the locking state of the locking mechanism.

[0041] The drive train proposed here comprises at least one drive machine, for example an internal combustion engine and / or an electric drive machine, which forms the torque source of a torque flow at least in one main state. Furthermore, at least one consumer is included, for example drive wheels of a motor vehicle, which forms the torque sink of the torque flow at least in one main state. Interposed is a transmission according to an embodiment as described above, via which the (preferably entire wheel-side) torque flow is directed. If the transmission is locked, the torque flow is locked and torque transmission in the drive train between the torque source and the torque sink is prevented.

[0042] The drivetrain proposed here comprises a transmission with such a parking lock device, with which both the drive position (free state) and the park position (locking state) can be maintained passively, i.e., without external energy consumption. Furthermore, the deviating (e.g., free) state of the parking lock can be canceled with very low power consumption (of the solenoid coil), thus ensuring that the normal (e.g., locking) state of the parking lock is assumed in almost all cases, even in the event of an electronics failure, for example, by means of a local electrical capacitor as an emergency storage device. The transmission can be implemented with the same installation space and with only minor additional costs compared to a parking lock device without the option of unlocking. Furthermore, there is a high degree of certainty that the drivetrain will only be operated as long as the parking lock device is unlocked.

[0043] According to a further aspect of the present invention, a motor vehicle is proposed, comprising at least one drive wheel and a drive train according to claim 12, wherein, for propelling the motor vehicle, a torque can be delivered from the at least one drive motor of the drive train to the at least one drive wheel, and rolling of the motor vehicle is prevented by means of the parking lock device in the locking state of the locking mechanism.

[0044] The motor vehicle is, for example, a passenger car, a truck, or a motorized two-wheeler. The motor vehicle has a drive train according to an embodiment as described above. The torque output by the at least one prime mover is transmitted via the transmission to the at least one drive wheel (consumer). The transmission referred to here is preferably a switchable transmission. Alternatively, the transmission is, for example, a fixed transmission, i.e., with an unchangeable transmission ratio, or a differential or a slip clutch. The parking lock device proposed here is preferably designed as described above and particularly preferably integrated into the transmission.

[0045] A rotational movement of at least one drive wheel in a park position is only possible if the parking lock (and the legally required parking brake) are released. For further details, please refer to the above description of the parking lock device.

[0046] The motor vehicle drivetrain proposed here comprises a transmission having such a parking lock device, with which both the drive position (free state) and the park position (locking state) can be maintained passively, i.e., without external energy consumption. Furthermore, the deviating (e.g., free) state of the parking lock can be canceled with very low power consumption (of the solenoid coil), thus ensuring that the normal (e.g., locking) state of the parking lock is assumed in almost all cases, even in the event of an electronics failure, for example, by means of a local electrical capacitor as an emergency storage device. The transmission can be implemented with the same installation space and with only minor additional costs compared to a parking lock device without the option of unlocking.In addition, there is a high level of security that the vehicle will only be put into operation as long as the parking lock device is unlocked.

[0047] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention, which is defined by the claims, is in no way limited by the purely schematic drawings, whereby it should be noted that the drawings are not to scale and are not suitable for defining proportions. It is shown in Fig. 1: a locking mechanism of a parking lock in the locking state; Fig. 2: an actuating actuator with an actuating element in the deflected position; Fig. 3: an actuating actuator according to Fig. 2with the actuating element in normal position; Fig. 4: a lifting magnet with an axial gap in a conical embodiment; Fig. 5: a lifting magnet with an axial gap in a purely axial embodiment; Fig. 6: a holding element with a locking receptacle (stopper); Fig. 7: the holding element according to Fig. 6 in the locking position; Fig. 8: the holding element Fig. 6 and Fig. 7 in a releasing position; and Fig. 9: a drive train with a parking lock device in a motor vehicle.

[0048] In Fig. 1 is a locking mechanism 21 a parking lock 2 (compare Fig. 9 ) in a normal-locking configuration in a locking state in a schematic side view with a locking wheel 22 The locking mechanism 21 includes a parking lock pawl 33, which rotates around its pawl axis 34is rotatably mounted and is shown here in the locked state. When the locking mechanism 21 is transferred to the locking state, the parking lock pawl engages 33 positively into the locking wheel 22 so that the locking wheel 22 is blocked. Then a traverse 35 from a preload spring 36 (shown here as a compression spring) is forced into such a position that (purely optionally by means of the support of the crossbeam 35 on a fixed frame 37, for example, part of a gearbox housing 27, compare Fig. 9 ) the parking lock pawl 33 in the locking state (tooth-in-gap engagement on the locking wheel 22) is geometrically blocked. In a free state of the traverse (not shown here) 35 is the preload spring 36tensioned (here compressed to the left as shown). In this embodiment, the parking lock pawl 33 by means of a release spring 38 (for example a leg spring or compression spring) from a tooth gap of the locking wheel 22 highlighted.

[0049] In the normal state, the parking lock pawl is 33 can only be transferred from the engaging (blocking) state to the free state by an actuating element 5 (here shown on the right) of an actuating actuator 1 active with an axial force 4 opposite to the preload by means of the preload spring 36 against the traverse 35 acts (as shown to the left) and the preload spring 36 tensioned. The actuator 1 is for example as in Fig. 2 and Fig. 3 shown. The parking lock pawl 33remains as long as the traverse 35 from the actuating element 5 of the actuating actuator 1 is deflected, in the free state and the locking wheel 22 is free around its wheel axis 39 rotatable.

[0050] In this advantageous embodiment, the parking lock comprises 2 purely optionally a release element 24, which in the embodiment shown is a pivoting axis 40 pivoting lever. The pivot axis is purely optional 40 perpendicular to the actuating axis 6. The release element shown here 24 acts with its actuating tip 41 (purely optional directly) onto the traverse 35, so that in this embodiment, with a clockwise pivoting around the pivot axis 40 the parking lock pawl 33can be transferred from the engaged (blocking) state to the free state. The actuating element 5 can remain in its first position (parking position).

[0051] In Fig. 2 is an actuating actuator 1 with an actuating element 5 shown in a deflected position in a schematic sectional view. The actuator 1 is for example used to operate a locking mechanism 21 according to Fig. 1 The actuator 5 is along an actuating axis 6 active by means of an axial drive 3 movable, so that as shown the actuating element 5 can be moved from right to left. The axial drive mechanism 3 is designed here as a fluidic, preferably hydraulic, slave unit. A slave piston 42 in a slave cylinder 43 (counter bearing 44)controlled by a fluid from a normal (here first) position to a deflected (here second) position. The resulting axial force 4 thus forces the actuating element 5 to the left as shown. In this case, no pulling force is exerted by the slave unit on the actuating element 5 transferable. Rather, the actuating element 5 by means of a first energy storage element 7 (here one coaxial to the actuation axis 6 arranged helical compression spring) is preloaded to the right as shown. It is therefore from the first energy storage element 7 one to the axial force 4 antagonistic storage power 9 on the slave piston 42 and thus on the actuating element 5 Without external energy absorption (here in the form of fluid pressure), the actuating element 5 so (passive) the normal position (compare Fig. 3 ) taken.

[0052] Here is a stopper element 10 which is firmly connected to the axial drive means 3. The stopper element 10 is designed here as a locking element, more precisely as (a plurality of) spring tabs, with a contact point. The corresponding stopper component 11 is with the counter bearing 44 of the axial drive means 3. The stopper component 11 is designed here as a complementary locking receptacle, whereby the contact point of the stopper element 10 by means of a corresponding undercut. The stopper element 10 slides when a sufficient axial force 4 of the axial drive 3 into the stopper component, which is designed here as an undercut 11 into it (positive locking), preferably in the manner of a snap closure. The stopping force 45is so small that it alone does not provide any protection against the storage force 9 of the first energy storage element 7 Rather, the storage power 9 so large that the connection between the stopper element 10 and the stopper component 11 can be released so that the actuating element 5 passively into the normal position. If there is no sufficient axial force 4 is generated, the stopper element slides 10 from the stopper component 11 out and the actuating element 5 assumes the normal position.

[0053] Because in a motor vehicle 32 the deflected position (with the locking mechanism 21 according to Fig. 1 Since the actuator is in a permanent state during operation (e.g., travel position), little or no external energy consumption is desired. For this purpose, a holding element 12By means of the holding element 12 is the stopper element 10 (at least additionally) secured against slipping out during the deflected position, here by means of a positive locking (snap lock). The holding force 46 of the holding element 12 is sufficient to ensure the connection between the stopper element 10 and the stopper component 11 against the storage power 9 of the first energy storage element 7 to fix.

[0054] The holding element 12 itself is in this embodiment by means of a second energy storage element 8 into the locking position shown by means of a holding force 47 pre-tensioned and thus secures the contact point of the spring tab (stopper element 10) in the locking groove (stopper component 11). If the coil 14 is energized, a magnetic field is generated that in the direction of the axial force4 pointing magnetic force 15 on the reciprocating piston 16 and thus to the holding element formed in one piece 12 is applied. The holding force 47 is overcome and the stopper element 10 detaches from the stopper component 11, if a sufficiently low (for example a negligible) axial force 4 As a result of the storage power 9 of the first energy storage element 7 the actuating element 5 returned to the normal position.

[0055] The lifting magnet 13 In the embodiment shown, it includes an internal conclusion 56 and an external conclusion 57, which the reciprocating piston 16 U-shaped. In these conclusions 56,57 runs (the main part) of the magnetic field of the coil 14. On the one hand, the reciprocating piston 16actuated like a moving coil and on the other hand an axial gap 55 (inclined here), whereby preferably a stop for the axial movement of the piston 16 The axial gap 55 has an axial extension which is equal to the desired stroke of the holding element 12 for releasing and locking the stopper element 10 is.

[0056] Furthermore, in the embodiment shown (purely optional) a magnetic field sensor 18 and a position magnet 17 (permanent magnet), whereby the magnetic field sensor 18 relative to the counter bearing 44 of the axial drive 3 is fixed and the position magnet 17 into the actuating element 5 is integrated. This means that the position of the actuating element 5 electronically recordable or ascertainable.

[0057] Furthermore, in the embodiment shown (purely optional), the actuating element 5 separate from the axial drive means 3 formed, here the slave piston 42, This is advantageous if the locking mechanism 21 should be unlocked. Then the slave piston can 42 return to the passive position while the actuating element 5 is still in the deflected position. In one embodiment, the actuating element 5 exclusively by means of the axial drive 3 into the deflected position. In the embodiment shown, an additional unlocking element is (purely optional) 24 By means of the unlocking element 24 can be moved into the deflected position from the outside (for example, via a screw or a push button). This represents an advantageous variant compared to the embodiment according to Fig. 1because it causes the magnetic field sensor 18 This means that a notification or electronic blocking of the commissioning of a motor vehicle 32 (for example via the vehicle’s on-board computer 32) easy to implement.

[0058] The unlocking element 24 can be pivoted around a pivot axis 40 designed, alternatively designed to be linearly movable. The actuating tip 41 of the unlocking element 24 acts directly against a flange of the actuating element 5, which is arranged here (purely optionally) at the tip on the lock side. The unlocking element 24 is therefore pivoted clockwise to the left as shown. By means of the force-transmitting contact from an actuating tip 41 on the actuating head 59 is the actuating element 5forced into the first position. The actuating element 5 is contrary to the storage power 9 of the first energy storage element 7 held in the first position. It should be noted that the actuating element 5 not from the unlocking element 24 is held in the deflected position shown, but by means of the interaction of the stopper element 10, the stopper component 11 and the holding element 12 (or the second energy storage element 8). An additional locking element to hold the release element 24 in the swivelled-out position shown is therefore not necessary. For example, the unlocking element 24opposite to the unlocking position shown, it is pre-tensioned into a normal position and automatically (passively) returns to the normal position after actuation. Alternatively, the unlocking element 24 freely movable or is connected to the actuating element 5 carried permanently.

[0059] In Fig. 3 is an actuating actuator 1 after Fig. 2 with the actuating element 5 shown in normal position. The slave piston 42 is by means of the storage power 9 of the first energy storage element 7 returned to the normal position. The (purely optional) design of the stopper element 10 as a plurality of coaxial to the actuating axis 6 arranged spring tabs, which here with the slave piston 42 are firmly connected, is clearly visible here. Furthermore, the (purely optional) design of the retaining element 12as a circumferential ring. It should be noted that the retaining element 12 is back in the blocking position, i.e. the coil 14 is de-energized or sufficiently low energized so that the holding force 47 the holding element 12 into the locking position. The axial force 4 is able to increase the holding force 47 to overcome and thus the stopper element 10 with the stopper component 11 to lock, whereupon the retaining element 12 returns to the locking position. The entire process is carried out without actuating the coil 14 executable.

[0060] In Fig. 4 is a lifting magnet 13 with an axial gap 55 in a conical design in a schematic sectional view. For clarity, the outlines of the individual components of the lifting magnet are shown in this view. 13and the magnetic field lines of the current-carrying coil 14 inside and outside the components. The lifting magnet 13 In this embodiment, it includes an internal conclusion 56, an external conclusion 57, and a coil 14 and a reciprocating piston 16 (as in Fig. 2 and Fig. 3 shown). The reciprocating piston 16 includes a holding element 12, which is preferably integral with the reciprocating piston 16 is manufactured. The reciprocating piston 16 is in this embodiment within the external conclusion 57 and the coil 14 The two conclusions include 56,57 the coil 14 and form a U-shaped opening at the right end as shown, in which the piston 16 axially movable in such a way that the axial gap 55 between the inner conclusion 56 and the holding element12 In this embodiment, the end of the inner short circuit 56 conical, as is the lower end of the piston 16 shown.

[0061] Due to the geometry of the internal return 56 and the reciprocating piston 16 In this embodiment, an axial gap results 55 with a slit normal 58 at an angle between the actuating axis 6 and the radial of the actuating axis 6 (compare Fig. 2 ). The conical design of the axial gap 55, with a to the actuating axis 6 inclined slit normal 58, has in this axial spacing between holding element 12 and internal conclusion 56 an increase in the magnetic field line density, which leads to an increased magnetic force 15 compared to a purely axial axial gap 55 leads (compare Fig. 5 ).

[0062] In Fig. 5 is a lifting magnet 13 with an axial gap 55 in a purely axial embodiment in a schematic sectional view. For clarity, the outlines of the individual components of the solenoid are shown in this view. 13 and the magnetic field lines of the current-carrying coil 14 inside and outside the components. This embodiment is, without exclusion of generality, purely for the sake of clarity, largely identical to the one shown in Fig. 4 shown embodiment is identical, so that reference is made to the description there and only the differences are discussed here.

[0063] In this embodiment, the end of the inner return path facing away from the coil is 56 purely axial, as is the lower end of the piston shown 16. This design of the ends of the piston 16and the internal conclusion 56, result in a lower magnetic field line density within the axial gap 55 than in the conical design in Fig. 4 . A lower magnetic field line density induces a lower magnetic force 15, which the reciprocating piston 16 to the coil 14 The axial gap 55 includes a gap normal 58, which here has a purely axial orientation. It should be noted that with a larger spacing between the holding element 12 and the internal conclusion 56 a lower magnetic force 15 necessary to move the piston 16 to the coil 14 This means that depending on the axial stroke of the piston 16, either the geometry according to Fig. 4 or as shown here is more advantageous.

[0064] In Fig. 6 is a holding element 12 with a stopper component11, which is designed as a locking receptacle, and a stopper element 10, which is designed as a locking element, more precisely as a snap hook, shown in a schematic sectional view. The locking receptacle (stopper component 11) is designed in such a way that a corresponding locking element (stopper element 10) can be accommodated. The holding element 12 is for fixing the stopper element 10 in the stopper component 11 set up and from the holding force 47 of the second energy storage element 8 is biased to the right as shown and is acted upon by the magnetic force 15 of the lifting magnet 13 movable to the left as shown (compare Fig. 2 to Fig. 5 ).

[0065] In Fig. 7 is the holding element 12 after Fig. 6 shown in the locking position. The holding force 46 of the holding element 12 results from the holding element 12leading system when the holding element 12 by means of the holding force 47 is held in the relative (locking) position shown, while the stopper element 10 in the stopper component 11 The actuating element 5 is thus axially fixed in the deflected position without the need for external energy absorption.

[0066] In Fig. 8 is the holding element 12 after Fig. 6 and Fig. 7 shown in a releasing position. The holding force 46 of the holding element 12 is canceled by the magnetic force 15 the holding force 47 of the second energy storage element 8 is overcome. If the axial force is absent (or too low) 4 the actuating element is now 5 again from the deflected position because the storage force 9 of the first energy storage element 7a radial deflection of the stopper element 10 and the stopper element 10 from the stopper component 11 solves.

[0067] In Fig. 9 is purely schematically a motor vehicle 32 with a drive train 25 shown in a plan view, with a drive machine 29, here optionally as an electric drive machine 29 shown, perpendicular to a longitudinal axis 49, along a motor axis 50 The motor axis 50 is in the direction of travel in front of a driver's cab 51 of the motor vehicle 32 The drive train 25 is used to propel the motor vehicle 32 by driving a left drive wheel 30 and a right drive wheel 31 (here optionally the front axle of the vehicle 32) by means of a torque output from the drive machine 29via a gearbox 20 set up, and so a dashed torque flow 23 (shown here with the direction corresponding to a tensile moment). For example, a torque transmission gear 26 a part of a gearbox 20, which is operated by means of a gearshift lever 52 in the driver's cab 51 can be switched by a vehicle driver.

[0068] In the torque flow 23 is now a parking lock device 19 arranged, whereby the left drive wheel 30 and the right drive wheel 31 can be locked. The parking lock device 19 includes a locking wheel 22, for example, a gear wheel of the torque transmission gear 26 of the gearbox 20 or an additional wheel of the torque transmission gear 26, and a parking barrier 2, where the parking lock 2a locking mechanism 21 and an actuating actuator 1 The locking mechanism 21 is for example as in Fig. 1 shown. Here is an embodiment of the parking lock device 19 shown, in which (optional) the locking mechanism 21 inside the gearbox compartment 28 in a gearbox housing 27 of the gearbox 20 and the actuating actuator 1 outside the gearbox housing 27 is arranged.

[0069] The locking wheel 22 is in the torque flow 23 arranged in such a way that the vehicle cannot roll away 32 can be prevented. The parking lock device 19 can be operated with at least one of the following controls: from a gearshift lever 52, for example by means of a parking switch position "P", a parking lever 53;and / or an ignition button 54 (alternatively an ignition key).

[0070] Furthermore, the parking lock device is preferred 19 can be operated automatically, for example when leaving the vehicle 32 (for example after locking) the parking lock 2 inserted automatically.

[0071] With the actuator proposed here, both the drive and park positions can be passively maintained. Furthermore, the parking lock can be released from a non-normal state (e.g., free) with very low power consumption. List of reference symbols 1 Actuator 32 motor vehicle 2 Parking lock 33 Parking lock pawl 3 Axial drive 34 pawl axis 4 axial force 35 traverse 5 Actuating element 36 Preload spring 6 Actuating axis 37 frame 7 first energy storage element (plunger) 38 release spring 39 wheel axle 8 second energy storage element (holding element) 40 Swivel axis 41 Actuating tip 9 Storage power 42 slave piston 10 Stopper element 43 slave cylinder 11 Stopper component 44 Counter bearing 12 Holding element 45 Stopping force 13 Lifting magnet 46 Holding force 14 Sink 47 Holding force 15 Magnetic force 48 ramp 16 reciprocating piston 49 Longitudinal axis 17 Position magnet 50 Motor axle 18 Magnetic field sensor 51 Driver's cab 19 Parking lock device 52 Gearshift lever 20 Gearbox 53 Parking lever 21 locking mechanism 54 ignition button 22 Locking wheel 55 axial gap 23 Torque flow 56 internal inference 24 Release element 57 external inference 25 Powertrain 58 Gap normal 26 Torque transmission gear 59 Actuating head 27 Gearbox housing 28 Gearbox compartment 29 drive machine 30 left drive wheel 31 right drive wheel

Claims

1. An actuator (1) for a parking lock (2), comprising at least the following components: - an axial drive means (3) for transmitting an axial force (4); - an actuating element (5) having an actuating axis (6), which is axially moveable from a normal position into a deflected position by means of the axial force (4) of the axial drive means (3); - a stopper element (10); - a stopper component (11) corresponding to the stopper element (10); and - a holding element (12) which is moveable between a released position and a locking position, wherein, while the actuating element (5) is in the deflected position, the stopper element (10) and the stopper component (11) are fixed relative to one another with the holding element (12) in the locking position, wherein a solenoid (13) having a coil (14) and a piston (16) that is axially moveable by means of a magnetic force (15) generated by the coil (14) is also provided, and wherein the holding element (12) is fixedly connected to the axially moveable piston (16), characterised in that the magnetic flux generated by the coil (14) is conducted through a return path, the return path comprises a radially inner return path (56) and a radially outer return path (57), which surround the piston (16) in a U-shape, an axial gap (55) is present between the piston (16) and the inner return path (56) in at least one of the two positions of the holding element (12), and the magnetic flux is conducted through the two surfaces of the piston (16) and the inner return path (56), which form the axial gap (55).

2. The actuator (1) according to claim 1, wherein the two surfaces of the piston (16) and the inner return path (56) are aligned relative to one another such that, when the coil (14) is energized, the piston (16) is moved in the direction of the inner return path (56), so that the axial gap (56) is reduced.

3. The actuator (1) according to claim 2, wherein the piston (16) and the inner return path (56) can be brought into contact with one another.

4. The actuator (1) according to claim 2 or 3, wherein the gap normal (58) of the axial gap (55) is inclined to the actuating axis (6) or is aligned purely axially.

5. The actuator (1) according to one of the preceding claims, wherein furthermore a second energy storage element (8) is comprised by the solenoid (13), from which a retaining force (47) antagonistic to the magnetic force (15) is retained on the piston (16), wherein the magnetic force (15) is preferably a tensile force.

6. The actuator (1) according to one of claims 1 to 3, wherein the coil (14) is received by the inner return path (56), the inner return path (56) is arranged coaxially to the actuating axis (6) and at least partially axially overlaps the actuating element (5) and / or a slave piston (42) comprised by the axial drive means (3).

7. The actuator (1) according to claim 6, wherein the outer return path (57) is fixedly connected to the inner return path (56) via a press fit.

8. A parking lock (2) for a parking lock device (19) of a transmission (20), comprising at least the following components: - a locking mechanism (21) for locking a locking wheel (22) in a torque flow (23), wherein, when the locking mechanism (21) is in a locking state, the locking wheel (22) is blocked and, in a free state, the locking wheel (22) is released; and - an actuator (1) according to one of the preceding claims, wherein, in the deflected position of the actuating element (5), the locking mechanism (21) is guided out of the locking state, and wherein the normal position of the actuating element (5) corresponds to the locking state of the locking mechanism (21).

9. The parking lock (2) according to claim 8, wherein an unlocking element (24) is further provided, which is moveable between a normal position and an unlocking position, wherein the free state of the locking mechanism (21) is maintained in the unlocking position and the normal locking function of the parking lock (2) is ensured in the normal position.

10. A parking lock device (19), having a locking wheel (22) for arrangement in a lockable torque flow (23) and a parking lock (2) according to claim 8 or claim 9, wherein the locking wheel (22) can be blocked by means of the locking mechanism (21).

11. A transmission (20) for a drive train (25), having at least the following components: - a parking lock device (19) according to claim 10; - a torque transmitting transmission (26) comprising the locking wheel (22); and - a transmission housing (27) which surrounds a transmission chamber (28), wherein the locking mechanism (21) of the parking lock (2), preferably completely, particularly preferably the entire parking lock device (19), is arranged in the transmission chamber (28).

12. A drive train (25), having at least the following components: - at least one drive unit (29) for outputting a torque; - at least one consumer (30, 31) for receiving a torque; and - a transmission (20) according to claim 11, wherein the at least one drive unit (29) and the at least one consumer (30, 31) are connected to one another in a torque-transmitting manner by means of the transmission (20), wherein torque transmission between the drive unit (29) and the at least one consumer (30, 31) is prevented by means of the parking lock device (19) in the locking state of the locking mechanism (21).

13. A motor vehicle (32), having at least one propulsion wheel (30, 31) and one drive train (25) according to claim 12, wherein a torque can be transmitted from the at least one drive unit (29) of the drive train (25) to the at least one propulsion wheel (30, 31) in order to propel the motor vehicle (32), and rolling of the motor vehicle (32) is prevented by means of the parking lock device (19) in the locking state of the locking mechanism (21).