Parking lock device with sensable emergency release with aluminum gripping element; gearbox and drive train

Abstract

Parking lock device (1) for a drive train (25) of a vehicle, comprising: - a locking mechanism (3) for locking a rotational movement of a shaft (23) of the drive train (25), wherein the locking mechanism (3) is switchable between a locking state in which the shaft (23) is blocked and an unlocked state in which the shaft (23) is rotationally released; - an actuator (4) with an actuating element (6) movable along a displacement axis (5) between an active position and a passive position, wherein the actuating element (6) acts on the locking mechanism (3) in such a way that the locking mechanism (3) is in its unlocked state in the active position and is capable of assuming its locking state in the passive position, and with a sensor (7) for detecting a position of the actuating element (6); and - an unlocking device (8), which in turn has a gripping element (9) for gripping an unlocking shoulder (10) of the actuating element (6), wherein the gripping element (9) is movably mounted between a normal position in which the actuating element (6) is freely movable relative to the gripping element (9), and an unlocking position in which the gripping element (9) holds the actuating element (6) in the active position, characterized in that the gripping element (9) is formed by casting and is made of an aluminum material.

Description

[0001] The invention relates to a parking lock device for a drive train, preferably for a transmission of the drive train, of a (preferably electrified, more preferably purely electrically driven) motor vehicle, such as a car, truck, bus, or other commercial vehicle. The parking lock device has a locking mechanism for locking a rotational movement of a shaft of the drive train ( / preferably the transmission), wherein the locking mechanism can be switched between a locking state in which the shaft is blocked, i.e., supported fixedly to the housing, and an unlocked state in which the shaft is rotationally released, i.e., freely rotatable relative to a housing.In addition, an actuator is provided with an actuating element movable along a displacement axis between an active position and a passive position, wherein the actuating element acts on the locking mechanism such that the locking mechanism is in its unlocked state in the active position and is capable of assuming its locking state in the passive position. The actuator also has a sensor for detecting a position of the actuating element. In addition, a (mechanical) unlocking device is provided, which in turn has a gripping element for gripping an unlocking shoulder of the actuating element, wherein the gripping element is movably mounted between a normal position, in which the actuating element is freely movable relative to the gripping element, and an unlocking position, in which the gripping element holds the actuating element in the active position.The invention also relates to a transmission and a drive train with this parking lock device.

[0002] Parking lock devices of this type are already well known in the prior art. For example, DE 10 2020 110 374 A1 discloses a parking lock in a normally locked configuration for a parking lock device of a transmission. A release element is pivotably mounted about a pivot axis that is skewed relative to an actuating axis. Further prior art is disclosed in DE 10 2022 103 385 A1.

[0003] However, it has been found that with these parking lock devices, the position of the actuating element can be incorrectly detected during use / operation of the sensor. This is particularly due to the surrounding components, especially the gripping element of the release device, whose movement relative to the actuator can introduce interference signals during operation, which the sensor also detects.

[0004] It is therefore an object of the present invention to provide a normally locking parking lock device with an unlocking device which enables a reliable determination of the actuator state in any operating state of the parking lock device.

[0005] According to the invention, this object is achieved by a parking lock device according to claim 1, in which the gripping element is formed by casting and is made of / consists of / is formed from an aluminum material.

[0006] By manufacturing the gripping element from aluminum (preferably an aluminum alloy), the gripping element is made of a material that is non-magnetic or only slightly magnetizable. This significantly reduces interference signals to the installed sensor. Furthermore, this enables a cost-effective yet robust design of the unlocking device.

[0007] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0008] It is advantageous if the gripping element is designed as a lever that is rotatably mounted around a pivot bearing fixed to the housing. This allows for a space-saving arrangement of the unlocking device.

[0009] Furthermore, it is advantageous if the pivot bearing is designed such that the gripping element can be relatively displaced and / or tilted along a main pivot axis defined by the pivot bearing (around which the gripping element rotates between the normal position and the unlocking position). This allows any tolerances that may exist in the individual components of the parking lock device to be easily compensated.

[0010] Furthermore, it is advantageous to provide a locking element for holding the gripping element in the unlocked position, wherein the locking element is adjustably accommodated in a housing-fixed receiving bushing. The receiving bushing is preferably formed integrally with the housing. This results in a space-saving integrated receptacle for the locking element within the housing.

[0011] In this context, it is also expedient if a stop elevation / protrusion is formed directly onto the gripping element, which is designed such that, in an assembled state of the parking lock device in which the actuator is not yet mounted on the housing, the gripping element rests against one end face of the housing-fixed receiving bushing. This ensures that the gripping element is supported as robustly and as gently as possible, even during assembly, with minimal wear and tear.

[0012] For optimal sealing, it has also proven advantageous if the locking element has a head region guided in the receiving bushing, with the head region accommodating two spaced-apart sealing rings that seal a gap between the receiving bushing and the locking element. The sealing rings are preferably implemented as O-rings. This achieves the most reliable seal possible between the space accommodating the parking lock device and its surroundings.

[0013] If the gripping element has a fork-shaped gripping area which is designed in such a way that it positively engages behind a mushroom-shaped end area of the operating element, at least in the unlocking position, this results in a low-wear support contour which at the same time functions as reliably as possible.

[0014] Furthermore, the invention relates to a transmission for a drive train of a motor vehicle, comprising a transmission shaft and a parking lock device according to the invention, coupled to the transmission shaft by means of the locking mechanism, according to at least one of the previously described embodiments.

[0015] In addition, the invention relates to a drive train for a motor vehicle, comprising an electric drive motor, a transmission connected downstream of this drive motor along a torque transmission path and a parking lock device according to the invention coupled to a shaft according to at least one of the previously described embodiments.

[0016] The invention will now be explained in more detail below with reference to figures.

[0017] They show: Fig. 1 a sectional view of a parking lock device according to the invention according to a preferred embodiment, used in a transmission of a drive train of a motor vehicle, wherein an actuator and a gripping element of an unlocking device connectable to an actuating element of the actuator are clearly visible, and wherein the gripping element is in a normal position in which it is spaced apart from / disengaged from the actuating element, Fig. 2 a sectional view of the parking lock device along a Fig. 1 section line marked “II-II”, showing a portion of the actuating element and a supporting projection of the actuator housing arranged laterally thereto, Fig. 3 a perspective view of the parking lock device in the area of the actuating element in the state of Fig. 1 and Fig. 2, which shows the support projection in more detail, Fig. 4 a perspective view of the Fig. 1 to 3 inserted gripping element to its front, Fig. 5 a perspective view of the gripping element from its rear side, Fig. 6 a perspective view of the parking lock device to illustrate a locking element cooperating with the gripping element, with a housing of the transmission hidden, Fig. 7 a perspective view of the parking lock device similar to Fig. 6, with the gripping element now again shown to its rear side, Fig. 8 a perspective view of the parking lock device, illustrating a sectioned pivot bearing of the gripping element, whereby the freedom of movement of the gripping element relative to the housing can be clearly seen, Fig. 9 a sectional view of the parking lock device, similar to Fig. 1, whereby the gripping element now engages around the support projection, Fig. 10 a sectional view along the Fig. 9 cutting line marked “XX”, Fig. 11 a sectional view of the parking lock device, similar to Fig. 1 and Fig. 9, wherein the gripping element is pivoted into its unlocking position while carrying the actuating element, in which the actuating element fixes the locking mechanism in its unlocking position, and Fig. 12. a sectional view along the Fig. 11 section line marked “XII-XII”.

[0018] The figures are merely schematic and serve solely to facilitate understanding of the invention. The same elements are designated by the same reference numerals.

[0019] With Fig. 1 clearly shows the basic structure of a parking lock device 1 according to the invention. The parking lock device 1 is mounted in a conventional manner in a Fig. 1 indicated transmission 2. The transmission 2 is in turn preferably part of a drive train 25 of a motor vehicle, which also preferably has an electric drive machine 24 connected upstream of the transmission 2, which in Fig. 1 is only indicated schematically. Thus, the drive motor 24 and the transmission 2 are arranged together in the drive train 25 downstream of one another along a torque transmission path.

[0020] It has also proven particularly advantageous if the transmission 2 and the drive motor 24 are housed in a common housing 27, forming a so-called electric axle / electric axle drive unit. The transmission 2 is then implemented as a manual transmission and is used in the usual way to convert the torque generated by the drive motor 24.

[0021] The parking lock device 1 therefore acts on a shaft / transmission shaft 23. However, it is also possible in principle to position the parking lock device 1 outside the transmission 2 in the drive train 25.

[0022] With Fig. 1, with respect to the transmission 2, a transmission shaft 23 is particularly indicated, which is provided with a locking gear 29. The locking gear 29 is in turn a component of a locking mechanism 3 of the parking lock device 1. The locking gear 29 is mounted on the transmission shaft 23 in a rotationally fixed manner. The locking gear 29 interacts with a locking lever 30. The locking lever 30 is switchable / pivotable in the usual manner between an unlocked state, in which it is out of positive engagement with the locking gear 29 and the transmission shaft 23 is consequently free to rotate, and a locking state / locked state, in which it is in positive engagement with the locking gear 29 and the transmission shaft 23 is fixed to the housing. Fig. 1 the blocking state is implemented.

[0023] It can also be seen that the parking lock device 1 is implemented as a normally locking parking lock device 1, so that in a rest state of the parking lock device 1 the locking lever 30 engages positively in the locking wheel 29 and thereby blocks the transmission shaft 23.

[0024] Also in Fig. 1 shows a cross member 32 which interacts with a support area 31 of the locking lever 30 and which, as explained in more detail below, can be displaced by actuating an actuator 4. In the locking state according to Fig. 1, the cross member 32 is arranged so that it fixes the locking lever 30 in the position engaging the locking wheel 29. In the unlocked state, the cross member 32 is according to Fig. 11 is displaced in such a way that the locking lever 30 automatically pivots out of the locking wheel 29 (by means of a spring not shown for the sake of clarity) and thus the gear shaft 23 is released for rotation.

[0025] Returning to Fig. 1 also shows the aforementioned actuator 4 of the parking lock device 1, which serves to move the cross member 32 and thus unlock or relock the locking lever 30 from the locking wheel 29. The cross member 32 and the locking lever 30 are components of the locking mechanism 3.

[0026] The actuator 4 has an actuating element 6 in the form of an armature / plunger that is (axially) movable along a displacement axis 5. In Fig. 1, the actuating element 6 is in a passive position, in which it allows the locking mechanism 3 to automatically assume the locking state (by means of a spring device acting on the cross member 32). Fig. 1 and Fig. 11 it is again evident that the actuating element 6 can in principle be switched between this passive position and a Fig. 11, wherein in the active position the locking mechanism 3 is brought into the unlocked state.

[0027] To detect the current position of the actuating element 6, in particular the active position and the passive position, a sensor 7 is housed in a housing-fixed component of the actuator 4. This sensor 7 is implemented as a Hall sensor. The sensor 7 thus directly detects the axial position (i.e., position along the displacement axis 5) of the actuating element 6.

[0028] In an unactuated state, the actuator 4 is in its passive position, while in its actuated state it is displaced toward the active position. Preferably, the actuator 4 is implemented as an electric linear motor.

[0029] Furthermore, a mechanical unlocking device 8 is provided, which serves, as can be seen from the Fig. 9 to 12, the actuating element 6 is mechanically fixed in its active position. This is particularly necessary in the event of a vehicle electrical system failure.

[0030] The further construction of the unlocking device 8 also results from these Fig. 9 to 12.

[0031] The unlocking device 8 has a gripping element 9 which is implemented as a lever. The gripping element 9 serves directly to grip an unlocking shoulder 10 of the actuating element 6. The gripping element 9 is in turn adjustable between a normal position, as shown in Fig. 9, and an unlocking position as shown in Fig. 11 can be seen, displaced / pivoted.

[0032] Regarding the bearing of the gripping element 9, reference is made to the Fig. 6 to 8. These figures show a fitting screw 33, which serves to pivotally mount the gripping element 9 on the housing 27. The fitting screw 33 is thus part of a pivot bearing 12 for mounting the gripping element 9 in the housing 27. The pivot bearing 12 thus defines a main pivot axis 13 about which the gripping element 9 can be pivoted between its normal position and its unlocking position.

[0033] In Fig. 8 it can also be seen in more detail that the pivot bearing 12, namely in particular a bearing eye 34 of the gripping element 9 and a bearing surface 35 / outer surface of the fitting screw 33 are matched to one another in such a way that the gripping element 9 can, on the one hand, perform an axial displacement along the main pivot axis 13 and, on the other hand, tilt along the main pivot axis 13, that is to say about a fixed point on the main pivot axis 13.

[0034] It can also be seen that a return spring 36 is partially swung around the fitting screw 33, which return spring 36 is inserted in such a way that it preloads the gripping element 9 into its normal position.

[0035] To fix the gripping element 9 in the unlocked position, a locking element 14 is provided. The locking element 14 is essentially designed as a threaded bolt / screw. The locking element 14 thus has a threaded portion 37. This threaded portion 37 is screwed into an internal thread 38 of a receiving bushing 15. The receiving bushing 15 is a direct, integral component of the housing 27. The locking element 14 is thus accommodated in the housing 27 so as to be adjustable along its longitudinal axis.

[0036] In addition, the locking element 14 has a head region 18, which also serves as a seal. For this purpose, two sealing rings 19 in the form of O-rings are accommodated in the head region 18, spaced apart from one another as viewed along the locking element 14. These sealing rings 19 directly serve to seal the gap 20 between the locking element 14 and the receiving bushing 15.

[0037] Furthermore, it should be noted that, as in the Fig. 4 and Fig. 5 clearly shows that the gripping element 9 is cast from an aluminum material according to the invention. The gripping element 9 is thus particularly suitable in conjunction with the use of the sensor 7 for detecting the position of the actuating element 6.

[0038] Furthermore, it should be noted that a raised stop 16 is integrally formed (primarily formed) on the gripping element 9 on a side facing the locking element 14. The raised stop 16 is positioned and configured such that, in an assembled state in which the actuator 4 has not yet been inserted into the housing 27, the gripping element 9 rests against an end face 17 of the receiving bushing 15 in the region of this raised stop 16 (with the locking element 14 in the maximum retracted position).

[0039] In the normal position, the locking element 14 is, as shown in Fig. 9 can be seen, fully retracted.

[0040] In connection with the Fig. 2, Fig. 10 and Fig. 12 it can also be seen that the gripping element 9 has a specially designed fork-shaped gripping area 21. This fork-shaped gripping area 21 is designed such that it is supported at a distance from the actuating element 6 in the normal position, wherein in Fig. 10 it can be seen in particular that the support is provided by a support projection 28 formed on the actuator housing 26.

[0041] As soon as the locking element 14 pivots the gripping element 9 toward the unlocking position, the gripping area 21 always automatically comes into positive engagement with the unlocking shoulder 10, as formed by a mushroom-shaped end area 22 of the actuating element 6. The actuating element 6 is thus moved along with the gripping area 21, which is moved toward the locking mechanism 3, and is finally brought into the active position. In this case, the actuating element 6 is brought into the active position, particularly when the actuator 4 is inactive. This state is mechanically fixed by the locking element 14.

[0042] In other words, the parking lock (parking lock device 1) according to the invention with unlocking mechanism (unlocking device 8) preferably consists of a fork (gripping element 9), a threaded pin (locking element 14), a leg spring (return spring 36) and a fitting screw 33, more preferably also additionally of a centering sleeve and a washer.

[0043] The fork engages the actuator plunger through a cam during actuation and pulls it downward. The plunger then pushes the parking lock cross member downward, as in normal operation.

[0044] The fork's link is designed to ensure the actuator plunger has free movement in the assembly position and to allow the plunger to be pulled out to its end position.

[0045] The position of the plunger is sensed in the actuator and thus the unlocking can be detected.

[0046] The fork is also operated by a threaded pin that is screwed on from outside the gearbox.

[0047] When the release is deactivated, the threaded pin in the 0 position is unscrewed. The leg spring then pulls the fork back to its 0 position.

[0048] If the actuator needs to be replaced, the actuator is unscrewed and pulled upwards. The leg spring then pulls the fork back into its mounting position until it reaches a defined stop on the housing. The new actuator can then be installed, and the plunger will engage the fork guide during installation until it reaches the zero position.

[0049] In the 0 position, the lever is pressed onto the lower surface of the actuator; the preload of the leg spring helps to avoid disturbing vibrations.

[0050] Because the tolerance chain from the actuator plunger to the housing is quite large, and because the gate must be positioned precisely on the plunger, the mechanism has a degree of freedom at the axis of the fitting screw. The fitting screw can slide on the sleeve, allowing the position of the fork to adjust along this axis on the plunger.

[0051] Therefore, during assembly, the fork is positioned by your fingers and a ramp on the actuator so that the plunger is engaged.

[0052] The leg spring is also axially preloaded to achieve this operating position.

[0053] The mechanism and the strength of the components are designed to ensure unlocking in the limit position (vehicle hanging with maximum weight on the maximum slope).

[0054] The fork's centering diameter is matched to the fitting screw to allow for a certain amount of pivoting. The fork can then align itself with the effective position of the plunger. A centering pin on the lower side of the actuator, close to the plunger, is used for this purpose. This projection therefore has a tighter tolerance with the actuator plunger.

[0055] The fork has a stepped slot so that its position is precisely determined by the pin during assembly of the actuator without touching the actuator plunger in the operating position.

[0056] The release fork is also constructed from die-cast aluminum, preventing magnetic interference with the actuator sensor.

[0057] The end stop is also located directly in the housing bore for the threaded pin, which is then screwed in from the outside. This can significantly reduce the stresses in the fork, especially in the case of misuse during towing from the vehicle, when the tightening torque of the threaded pin is not taken into account.

[0058] Additionally, two O-rings are provided on the head of the threaded pin. This ensures the seal is always secure, not just in the operating position and when the user pulls out the threaded pin. The double seal also prevents leakage in aggressive environments (salt).

[0059] The system is also designed so that the set screw cannot be removed, thus never damaging the seal. The set screw is no longer unscrewed to a specific torque; it simply slides out of the bore thread in the operating position. The snap ring 39 installed inside the set screw prevents it from moving out due to vibration. The friction between the two O-rings also helps.

Claims

[1] Parking lock device (1) for a drive train (25) of a vehicle, comprising: - a locking mechanism (3) for locking a rotational movement of a shaft (23) of the drive train (25), wherein the locking mechanism (3) is switchable between a locking state in which the shaft (23) is blocked and an unlocked state in which the shaft (23) is rotationally released; - an actuator (4) with an actuating element (6) movable along a displacement axis (5) between an active position and a passive position, wherein the actuating element (6) acts on the locking mechanism (3) in such a way that the locking mechanism (3) is in its unlocked state in the active position and is capable of assuming its locking state in the passive position, and with a sensor (7) for detecting a position of the actuating element (6); and - an unlocking device (8), which in turn has a gripping element (9) for gripping an unlocking shoulder (10) of the actuating element (6), wherein the gripping element (9) is movably mounted between a normal position in which the actuating element (6) is freely movable relative to the gripping element (9), and an unlocking position in which the gripping element (9) holds the actuating element (6) in the active position, characterized by that the gripping element (9) is formed by casting and made of an aluminum material. [2] Parking lock device (1) according to claim 1, characterized by that the gripping element (9) is designed as a lever (11) which is rotatably received about a pivot bearing (12) fixed to the housing. [3] Parking lock device (1) according to claim 2, characterized bythat the pivot bearing (12) is designed such that the gripping element (9) is relatively displaceable and / or tiltable along a main pivot axis (13) defined by the pivot bearing (12). [4] Parking lock device (1) according to one of claims 1 to 3, characterized by that a locking element (14) is provided for holding the gripping element (9) in the unlocking position, wherein the locking element (14) is adjustably received in a receiving bushing (15) fixed to the housing. [5] Parking lock device (1) according to claim 4, characterized by that a stop elevation (16) is formed directly on the gripping element (9), which is designed such that the gripping element (9) is in contact with an end face (17) of the housing-fixed receiving bush (15) in an assembled state of the parking lock device (1), in which the actuator (4) is not yet mounted on the housing side. [6] Parking lock device (1) according to claim 4 or 5, characterized bythat the locking element (14) has a head region (18) guided in the receiving bush (15), wherein the head region (18) receives two spaced-apart sealing rings (19) which seal a gap (20) between the receiving bush (15) and the locking element (14). [7] Parking lock device (1) according to one of claims 1 to 6, characterized by that the gripping element (9) has a fork-shaped gripping region (21) which is designed such that it positively engages behind a mushroom-shaped end region (22) of the actuating element (6), at least in the unlocking position. [8] Transmission (2) for a drive train (25) of a motor vehicle, comprising a transmission shaft (23) and a parking lock device (1) according to one of claims 1 to 7, coupled to the transmission shaft (23) by means of the locking mechanism (3). [9] Drive train (25) for a motor vehicle, comprising an electric drive motor (24), a transmission (2) connected downstream of said drive motor (24) along a torque transmission path, and a parking lock device (1) coupled to a shaft (23) according to one of claims 1 to 7.

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