VEHICLE PARKING LOCK

Description

Technical area

[0001] The invention relates to a parking lock for vehicles, wherein the parking lock comprises a locking wheel and a pawl interacting with the locking wheel, which is actuated by an actuator via an actuator shaft. Furthermore, the invention relates to an electric axle module of an electrically powered vehicle having such a parking lock. State of the art

[0002] DE 101 43 386 B4 relates to a parking lock for a motor vehicle with a drive train, comprising a drive shaft operatively connected to the drive wheels and having a positively lockable engagement gear. Furthermore, an elastic spring element is provided, which absorbs rotational energy of the drive train when the engagement gear is locked as a result of a relative rotation of the engagement gear and a flange arranged on the drive shaft in a rotationally fixed manner.

[0003] In electrically powered vehicles, the transmission input shaft and the parking lock ratchet are firmly connected to the rotor of the electric motor. Suitable means are designed to dissipate the rotor's rotational energy in the event of an abrupt engagement of the parking lock.

[0004] For rotational drive, the meshing gear is operatively connected to a flange mounted on the drive shaft in a rotationally fixed manner. Alternating positive locking profiles are provided at the two element ends, between which at least one elastic spring element is arranged. In particular, the positive locking profiles are designed as radial teeth. This creates U-shaped chambers in cross-section, into which the elastic spring elements, also with a substantially U-shaped cross-section, are embedded. An elastomer, particularly HNBR, is preferred as the material for the elastic spring element.

[0005] For example, a number of radially outward-running webs are formed on the flange, and the same number of webs, but radially inward-running, are present on an engagement gear as a ratchet wheel. The spring element can be manufactured, for example, using an injection molding process and is deformed upon relative movement of the ratchet wheel and flange, resiliently absorbing residual rotational energy from the drive train. To accommodate this deformation, various cavities are provided adjacent to the spring elements in the direction of the flange and the ratchet wheel.

[0006] EP 2 410 214 B1 relates to a locking mechanism for non-rotatably locking a shaft, which is used particularly in parking locks in electric vehicles. The aim is to provide a locking mechanism that can absorb high loads and is simultaneously cost-effective to manufacture and has a compact design. The disclosed parking lock comprises a ratchet wheel, which is connected directly or indirectly to the intermediate shaft via a damping element, for example, a plastic part, a torsion spring, or the like, to dampen peak loads.

[0007] From US 2020 / 166131 A1 and DE 10 2025 206 157 A1, parking locks for vehicles are known which comprise a locking wheel and a pawl cooperating with the latter, which can be actuated by means of an actuator via an actuator shaft. Disclosure of the invention

[0008] A parking lock for vehicles according to claim 1 is proposed, wherein the parking lock comprises a locking wheel and a pawl cooperating therewith, which is actuated by an actuator via an actuator shaft. Upon actuation of the pawl upon engagement of its locking position and engagement of its release position of the locking wheel, which corresponds to a release of the locking wheel, the actuator is driven in the same direction of rotation, wherein the actuator shaft drives a shaft which runs at a 90° offset to the actuator shaft and which has a groove on the circumference of the shaft in which at least one sliding block or roller of a sliding piece is guided, wherein the sliding piece has an anti-twist device and, upon a rotational movement of the shaft, moves in a translational direction parallel to the axis of rotation of the shaft, and the sliding piece is operatively connected to the pawl.According to the invention, the groove in the shaft extends in a meandering or thread-like manner at a circumferential angle of 720°, corresponding to two complete revolutions of the shaft.

[0009] The inventive design of the parking lock significantly reduces the number of moving parts. Furthermore, the inventive design of the parking lock allows for extremely fast engagement speeds. Finally, it should be noted that the actuator that drives the parking lock only operates in one direction, as both engaging and releasing the parking lock according to the invention is driven in one direction, making the actuator more cost-effective due to the reduction in parts.

[0010] According to the invention, the actuator shaft of the actuator drives a shaft that runs at a 90° offset from the actuator shaft and further comprises a groove in which a slide rail or a roller of a sliding piece is guided. The 90° offset between the shaft and the actuator shaft allows for self-locking of the parking lock proposed according to the invention if the power supply of an electrically driven actuator is interrupted.

[0011] The groove machined into the shaft extends in a meandering or thread-like manner at a circumferential angle of 720° along the shaft, corresponding to two complete revolutions of the shaft. This contributes to an increase in insertion speed; furthermore, a very fast disengagement movement can be achieved, which is due to the 720° circumferential extension of the groove in the shaft.

[0012] The sliding piece has an anti-rotation device and, during a rotational movement of the shaft, moves in a translational direction parallel to the shaft's axis of rotation. The sliding piece converts the rotational movement of the shaft into a translational direction of the sliding piece parallel to the shaft's axis of rotation, thereby easily causing a roller carriage of the parking lock, which interacts with a ramp of the pawl, to undergo a translational movement, which causes the pawl to pivot about an axis.

[0013] Further advantageous embodiments of the invention emerge from the dependent claims.

[0014] In a further advantageous embodiment of the parking lock proposed according to the invention, the roller carriage is guided in a guide and comprises at least one rolling element. This design of the parking lock proposed according to the invention enables secure guidance and thus reliable actuation of the parking lock via the guided roller carriage.

[0015] In a further advantageous embodiment of the parking lock proposed according to the invention, the pawl which interacts with the locking wheel is designed such that it can be pivoted about a pawl axis.

[0016] In a further advantageous embodiment of the parking lock proposed according to the invention, the pawl has a ramp surface that rests on the at least one rolling element of the trolley. A translational movement of the trolley, which results from a rotational movement, results in the movement of the ramp surface, which is particularly advantageously located on the underside of the pawl, which is movable about its pawl axis.

[0017] In a further advantageous embodiment of the parking lock proposed according to the invention, a spring surrounding the shaft is accommodated between the trolley and the sliding piece. The spring is preferably designed as a compression spring and rests with one side against a collar on the trolley and with the other side against the sliding piece, keeping them spaced apart.

[0018] In a further advantageous embodiment of the parking lock proposed according to the invention, the actuator shaft is provided with a worm which meshes with a worm wheel of the shaft, which has a 90° offset with respect to the actuator shaft.

[0019] The invention further relates to an e-axle module of an electrically powered vehicle with such a parking lock. Advantages of the invention

[0020] The parking lock proposed according to the invention is characterized by a significant reduction in the number of moving parts compared to prior art parking lock solutions. The mechanical design allows for extremely fast engagement of the parking lock proposed according to the invention.

[0021] Particularly advantageously, the actuator can be driven in only one direction, so that only one direction of rotation of the actuator is required to engage and release the parking lock. This allows for a significantly more cost-effective design of the actuator by eliminating parts, since only one drive direction needs to be ensured.

[0022] The solution proposed according to the invention allows very short switching times due to the achievable high engagement speed of the parking lock proposed according to the invention.

[0023] The advantageous design of the worm and worm gear, which are arranged with a 90° shaft offset relative to each other on the parking lock proposed according to the invention, can be represented in two basic variants. In the first variant, with a self-locking worm, this locks the parking lock system in the event of a fault, for example, an electrical failure of the actuator. This means that the pawl remains in the locking gear and the vehicle cannot roll away uncontrollably. This variant requires an actuator that can be rotated in a clockwise and a counterclockwise direction. This is independent of the drive direction of the actuator used.

[0024] In a second design variant, i.e. in the case of a worm gear that is not designed to be self-locking, in the event of a fault, for example in the case of an electrical failure of the actuator, the spring force acting on the entire system pushes the actuator back and the pawl releases the ratchet wheel, so that at least some movement of the vehicle is possible again. Short description of the drawings

[0025] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0026] They show: Figure 1 shows an embodiment of a parking lock, Figure 2 shows a schematic representation of the structure of the parking lock proposed according to the invention, Figure 3 shows a side view of the parking lock proposed according to the invention according to Figure 2, Figure 4 is a perspective view of the parking lock proposed according to the invention with translation and rotation directions of the components involved, Figure 5 is a view of the parking lock proposed according to the invention in the 1 o'clock position of the actuator shaft, Figure 6 is a perspective view of the parking lock proposed according to the invention in the 5 o'clock position of the actuator shaft, Figure 7 is a view of the parking lock proposed according to the invention in the 8 o'clock position of the actuator shaft and Figure 8 is the 1 o'clock position of the actuator shaft after its complete rotation in the clockwise direction.

[0027] Figure 11 shows a parking lock 10 having a ratchet wheel 12 which is mounted on a drive shaft 14 in a rotationally fixed manner. The ratchet wheel 12 has a toothing 16 comprising individual teeth 18 which are separated from one another in the circumferential direction by tooth gaps 20. A pawl 22 is associated with the ratchet wheel 12 and is rotatable about a pawl axis 24. The parking lock 10 according to Figure 1 is actuated by an actuator 26. The parking lock 10 has a rack and pinion mechanism with which the pivoting movement of the pawl 22 is initiated. Embodiments of the invention

[0028] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0029] Figure 2shows a perspective view of the essential components of the parking lock 10 proposed according to the invention.

[0030] How Figure 2 shows, the locking wheel 12 of the parking lock 10 is mounted on the drive shaft 14 in a rotationally fixed manner. On the circumference of the locking wheel 12, which is made of a metallic material, a plastic material or as a hybrid component, there is the toothing 16, which has a number of teeth 18 that are separated from each other in the circumferential direction by individual tooth gaps 20. Below the locking wheel 12 of the parking lock 10, as shown in Figure 2 the pawl 22, which is pivotable about the pawl axis 24. The parking lock 10 also comprises an actuator shaft 28, only partially shown here, which is driven by an actuator 26, such as in Figure 1The actuator 26 can be, for example, an electric drive. This drives the actuator shaft 28, which has a Figure 2 not shown screw 40. This meshes with a Figure 2 The worm gear 42, only partially shown, is attached to one end of a shaft 44. On this shaft 44 is a rotation lock 32 of a sliding piece 30, hidden here.

[0031] The shaft 44 is connected to a roller carriage 34. The roller carriage 34 comprises at least one rolling element 98. The rolling element 98 interacts with a ramp surface 100 of the pawl 22, while another rolling element 98 of the roller carriage 34 is guided in a guide 36 of the housing of the parking lock 10.

[0032] As can be seen from the perspective view of the parking lock 10 according to Figure 2As can be seen further, both the shaft 44 and parts of the trolley 34 are enclosed by a spring 38. This spring is supported with one end face on a collar of the trolley 34 and with its opposite end face on an end face of the sliding piece 30 with anti-twist device 32.

[0033] Figure 3 shows a side view of the parking lock 10 proposed according to the invention. Figure 3 It can be seen that the sliding piece 30 is mounted on the circumference of the shaft 44. On its inner circumferential surface is a roller or a sliding block 48 or the like, which runs within a groove 50. This groove extends on the circumference of the shaft 44 in a meandering shape or in the form of a thread around a circumferential angle of 720°, which essentially corresponds to two full revolutions of the shaft 44. Figure 3It is further apparent that the spring 38 - designed as a compression spring - is supported on one side on the sliding piece 30 and on the opposite side on a collar of the trolley 34. The shaft 44 rotates about its axis of rotation 46 and has on one end face the worm gear 42, which is driven by the worm 40 of the actuator shaft 28. As Figure 3 shows, the shaft 44 is arranged at a 90° shaft offset 74 with respect to the actuator shaft 28. From the illustration according to Figure 3 It can be seen that the pawl 22 with its pawl tooth is retracted into a tooth gap 20 between two teeth 18 of the ratchet wheel 12 (not shown in detail here), the rotation of which is therefore blocked in the circumferential direction.

[0034] Figure 4 shows a perspective view of the parking lock proposed according to the invention from its drive side.

[0035] The Handle 22 - in Figure 4only partially shown - is pivotable about the pawl axis 24 of the parking lock 10. The sliding piece 30 arranged on the circumference of the shaft 44 is movable in the translation direction 54 according to the double arrow. On the inner circumferential surface of the sliding piece 30 is the sliding block 48 or the roller, which is guided in the groove 50 on the circumference of the shaft 44. The actuator shaft 28 is Figure 4The actuator 26 (not shown in detail) is driven in a clockwise direction of rotation 52. As a result, the worm gear 42 on the end face of the shaft 44, which meshes with the worm 40 of the actuator shaft 28, is driven clockwise about its axis of rotation 46. Due to the anti-rotation device 32 of the sliding piece 30, this converts the rotational movement of the shaft 44 about the axis of rotation 46 into a movement in the translational direction 54. The range of movement of the trolley 34 thus corresponds to the degree to which the sliding piece 30 is moved on the circumference of the shaft 44 in the translational direction 54.

[0036] The figure sequence of the Figure 5 , 6 , 7 and 8various positions, namely a 1 o'clock position 80 of a pointer 76 on the actuator shaft 28, the 5 o'clock position 82 of the pointer 76, the 8 o'clock position 84 of the pointer 76 and the 1 o'clock position 80 of the pointer 76 of the actuator shaft 28 reached again after a full clockwise rotation 70 of the actuator shaft 28 can be seen in detail.

[0037] In Figure 5 When the actuator shaft 28 is driven, its rotation - shown here by the pointer 76 - occurs in a clockwise direction 70. A pointer 78 on the end face of the worm gear 42 moves in a counterclockwise direction 72 as the shaft 44 rotates. As the shaft 44 rotates, the sliding block 48 or a corresponding roller runs in the groove 50. Rotation of the sliding piece 30 is prevented by the anti-rotation device 32. The shaft 44 is connected to the roller carriage 34; the spring 38 is received between a collar of the roller carriage 34 and an end face of the sliding piece 30.

[0038] From the representation according to Figure 5 It can be seen that the pawl 22 is set in the locking position 86, thus engaging a tooth gap 20 between two adjacent teeth 18 of the ratchet wheel 12. A contact zone exists between the rolling body 98 of the rolling carriage 34 and a ramp surface 100 on the underside of the pawl 22. Thus, in the 1 o'clock position 80, the pawl 22 is locked in its locking position 86.

[0039] When the actuator shaft 28 is rotated clockwise 70 from the Figure 5 shown 1 o'clock position 80 into a Figure 6The worm gear 42 rotates counterclockwise 72 in the illustrated 5 o'clock position 82 corresponding to the position of the pointer 76 shown there. The sliding piece 30 performs a translational movement, so that the rolling carriage 34 performs a translational movement in the direction of the worm gear 42 in accordance with the course of the groove 50 and a decreasing contact 96 is established between the rolling body 98 of the rolling carriage 34 and the ramp surface 100 on the underside of the pawl 22. In the Figure 6 In the illustrated 5 o'clock position 82 of the actuator shaft 28, the pawl 22 is still in the locking position 86, ie between two teeth 18 of the ratchet wheel.

[0040] If the actuator shaft 28 is rotated further from the Figure 6 shown 5 o'clock position 82 into the Figure 7At the 8 o'clock position 84 shown, the sliding piece 30 is moved further in the direction of the worm wheel 42 and the rolling carriage 34 moves away from it in accordance with the geometry of the ramp surface 100, whereby the pawl 22, which is movable about the pawl axis 24, moves in an extension direction 90 out of the toothing gap 20 between two adjacent teeth 18 of the ratchet wheel 12. The release movement of the pawl 22 occurs by the rolling body 98 of the rolling carriage 34 rolling on the ramp surface 100 on the underside of the pawl 22. Accordingly, a pivoting movement of the pawl 22 occurs about the pawl axis 24 when the pointer 76 of the actuator shaft 28 moves from the 5 o'clock position 82 to the 8 o'clock position 84 as shown in Figure 7 .

[0041] The complete release of the locking wheel 12 is in Figure 8shown. Here, the pointer 76 of the actuator shaft 28 has reached its 1 o'clock position 80 again after a complete 360° rotation of the actuator shaft 28. The sliding piece 30, which is guided translationally on the circumferential surface of the shaft 44 due to the provision of the anti-rotation device 32, has reached its maximum proximity to the worm gear 42. The trolley 34, which is coupled to the shaft 44, has moved under the pawl 22, which is due to the rounding of the ramp surface 100 on the underside of the pawl 22, which is pivotable about the pawl axis 24.

[0042] As can be seen from the illustration according to Figure 8 As can be seen, the tooth gap 20 between the teeth 18 of the locking wheel 12 is released (see release position 94). The parking lock 10 is in the Figure 8 shown release position 94 is deactivated, so that the drive shaft 14, which is non-rotatably coupled to the locking wheel 12 of the parking lock 10, can rotate freely in both directions of rotation.

[0043] When the actuator 26 is again activated to rotate the actuator shaft 28 in the clockwise direction 70, it is moved further in the same direction of rotation and transferred, correspondingly, with a further complete 360° rotation of the actuator shaft 28 or of its pointer 76, the pawl 22 is transferred by a pivoting movement about the pawl axis 24 from the position shown in Figure 8 shown release position 94 into the Figure 5 Locking position 86 shown, as already described above in connection with Figure 5 described.

[0044] The key advantage of the solution proposed by the invention lies in the significantly simplified design of the actuator 26, in that it is driven in the same direction both for engaging the parking lock 10 and for deactivating it. This allows for a significantly simpler design of the actuator 26 and also offers high engagement speeds for the parking lock 10 as well as rapid release options. Furthermore, the solution proposed by the invention enables extremely short switching times due to the extremely high engagement and disengagement speeds with respect to the pawl 22.

[0045] With the parking lock 10 proposed according to the invention, the worm 40 or the worm gear 42, arranged at a 90° shaft offset 74 from each other, can be designed such that they are self-locking or non-self-locking. If a self-locking worm drive is configured, this locks the system in the event of a fault, for example, if the electric actuator 26 fails. This means that the pawl 22 remains in the locking gear 12 and the vehicle cannot roll away uncontrollably. This requires an actuator 26 that can rotate clockwise and counterclockwise, regardless of its drive direction.If the worm 40 and worm gear 42 are designed to create a non-self-locking worm drive, in the event of a fault, for example, if the electric actuator 26 fails, the entire system is pushed back due to the force of the spring 38, causing the trolley 34 to retract and the pawl 22 to release the ratchet wheel 12. In this case, the vehicle can at least be moved again.

[0046] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art.

Claims

1. Parking lock (10) for vehicles, wherein the parking lock (10) comprises a locking wheel (12) and a pawl (22) which interacts with it, which can be actuated by means of an actuator (26) via an actuator shaft (28), wherein, when the pawl (22) is actuated, when its locking position (86) is engaged and its release position (94) is engaged, corresponding to a release of the locking wheel (12), the actuator (26) is driven in the same direction of rotation (52), and wherein the actuator shaft (28) drives a shaft (44) which runs at a 90° offset (74) to the actuator shaft (28) and which has a groove (50) on the circumference of the shaft (44), in which at least one sliding block (48) or a roller of a sliding piece (30) is guided, wherein the sliding piece (30) has a torsion protection means (32) and moves in a rotational movement of the shaft (44) in a translational direction (54) parallel to the rotational axis (46) of the shaft (44) and the sliding piece (30) is operatively connected to the pawl (22), characterized in that the groove (50) in the shaft (44) extends in a meander or thread turn form at a circumferential angle of 720°, corresponding to two complete revolutions of the shaft (44).

2. Parking lock (10) according to Claim 1, characterized in that the parking lock (10) has a roller carriage (34) which is connected to the shaft (44), is guided in a guide (36) and has at least one rolling body (98).

3. Parking lock (10) according to either of Claims 1 and 2, characterized in that the pawl (22) is pivotable around a pawl axis (24).

4. Parking lock (10) according to Claim 2 or according to Claim 3 in conjunction with Claim 2, characterized in that the pawl (22) has a ramp surface (100) which rests on the at least one roller body (98) of the roller carriage (34).

5. Parking lock (10) according to Claim 2 or according to Claim 4 or according to Claim 3 in conjunction with Claim 2, characterized in that a spring (38) surrounding the shaft (44) is received between the roller carriage (34) and the sliding piece (30).

6. Parking lock (10) according to one of Claims 1 to 5, characterized in that the actuator shaft (28) has a worm (40) which meshes with a worm gear (42) of the shaft (44).

7. E-axle module of an electrically driven vehicle with a parking lock (10) according to one of the preceding claims.