parking lock

Abstract

The present invention relates to a parking lock (10) for a motor vehicle transmission, the parking lock having: a locking pawl (12) rotatable about a rotation axis (14), the locking pawl having locking teeth (16) configured to lock the parking lock gear (56) in a locked position and release the parking lock gear (56) in an unlocked position; a locking cone (52) by means of which the locking pawl (12) can move to the locked position; and a guide rod (58) on which the locking cone (52) is linearly movably disposed. A rotary joint (54) is provided between the locking teeth (16) and the guide rod (58).

Description

Technical Field

[0001] The present invention relates to a parking lock, the parking lock comprising: a locking pawl rotatable about a rotation axis, the locking pawl having locking teeth configured to lock the parking lock gear in a locked position and release the parking lock gear in an unlocked position; a locking cone via which the locking pawl can move to the locked position; and a guide rod on which the locking cone is linearly movably disposed. Background Technology

[0002] Parking locks are known, for example, from DE 101 44 063A1. This describes a parking lock in an automatic transmission of a motor vehicle, the parking lock having a locking ring with a locking recess disposed on the transmission shaft. A pawl engages with the locking recess in the locked state of the device by means of a pivotable selector lever and a connecting rod hinged thereon. The connecting rod has rollers at its end, a second roller of which guides the connecting rod in an L-shaped guide plate. The guide plate is fixed in the housing of the automatic transmission. The second roller rolls on the guide plate during longitudinal movement of the connecting rod. Here, the guide plate includes sidewalls and a horizontally extending wall. The horizontally extending wall of the guide rod has an elongated hole. The sidewall of the guide plate is a separate component and has a crenellated protrusion at its edge. The protrusion, with respect to its dimensions, matches the elongated hole of the horizontally extending wall and can be engaged into the opening of the horizontal wall by means of a press fit.

[0003] Other parking locks are known from CN 104 534 087A and DE 101 44 058A1. The latter illustrates such a parking lock. Parking locks with locking pawls and operating units are mounted to the transmission housing, thereby supporting the parking lock gear mounted on the powertrain. Tolerances are derived from different fixed reference points, and these tolerances must be compensated for. In particular, dimensional fluctuations occur between the centering hole in the housing and the contact surface of the operating unit that moves the locking pawl due to manufacturing reasons. Therefore, adjustment work is always performed during parking lock installation to precisely position the pawl relative to the parking lock gear. While it is conceivable to shift the adjustment work from the parking lock gear-locking pawl interface to the locking pawl-locking pawl operating mechanism interface, this introduces the disadvantage that the parking lock, along with its actuator, cannot be supplied as a pre-produced module, which increases installation costs; the locking pawl operating mechanism is, for example, an electric motor.

[0004] DE 10 2018 131 263B4 proposes a movable plate that tilts to compensate for manufacturing tolerances. The locking element can tilt by introducing a load at pawl contact and deducing a load at the transmission housing / plate contact point to two non-opposing contact points of the locking element, until the two contact force vectors meet again on the central axis of the locking element. It has been shown that this type of tolerance compensation is not sufficient in all cases. Angled compensation cannot be achieved over the entire circumference due to the typically guided locking element on the guide rod and the insufficient degrees of freedom present therebetween. Therefore, the locking element is supported on the guide rod, the load is introduced, and the guide rod bends. This causes a significant limitation on the function of the parking lock. Summary of the Invention

[0005] The purpose of this invention is to improve the parking lock and avoid the above-mentioned disadvantages.

[0006] The objective is achieved by a parking lock having the features of the present invention.

[0007] The parking lock according to the invention has a rotary joint disposed between the locking teeth and the guide rod. "Between" here is understood in a functional sense. Additionally, a spatial physical device can also be provided between the components. If the load in the parking lock is supported in the housing via staggered contact points, the rotary joint rotates such that the force vectors acting meet at the locking element's central axis, thus preventing the generation of torque. Tilting is therefore prevented from the outset, preventing adjacent components, especially the guide rod, from bending.

[0008] In contrast to solutions in the prior art, rotary joints not only enable larger gap compensation, but also enable gap compensation in different directions.

[0009] In the first embodiment of the invention, the rotary joint performs angular compensation not only in the locked position but also in the region of possible positions of the locking cone. Ideally, angular compensation occurs throughout the entire movement path of the locking element from the disengaged position "nP" to the engaged position "P". This reduces the maximum load on the parking lock components, allowing the parking lock to be constructed in a lighter and smaller form factor.

[0010] In another design, a rotary joint is positioned between the locking cone and the guide rod. This eliminates the need for adjustment of the locking pawl, allowing it to be manufactured as a single piece, as is done in the prior art.

[0011] If the rotary joint can achieve angular compensation directly in the locking cone during the entire engagement and disengagement of the parking lock, then it ensures that the two acting contact force vectors at the locking element always meet on the central axis of the locking element, thus preventing torque from being generated.

[0012] A rotary joint can also achieve this: transferring the necessary adjustments from the locking pawl-parking lock gear interface to the parking lock itself. Additionally, the locking cone, in the locked position, can be supported on a support element that is loosely connected to the parking lock housing. This clearance is chosen such that typical manufacturing tolerances can be compensated for. The "floating" arrangement of the support element within its boundaries thus introduces additional degrees of freedom, allowing for internal compensation of manufacturing tolerances. The self-adjusting, automatic orientation of the support element thereby allows the entire parking lock to be installed as a pre-produced unit, eliminating the need to compensate for production inaccuracies during installation. More precisely, this self-adjustment additionally enables the parking lock to be installed in the running position nP, since tolerance compensation is also possible when operating the parking lock pawl.

[0013] In its simplest form, the rotary joint can be configured as a ball supported on a guide rod. The ball has a central hole for the guide rod. A locking cone is provided on the ball, resulting in a compact unit. In this case, the locking cone can form a housing or support cover for the ball. The locking cone thus slides on the surface of the ball and ensures angular compensation.

[0014] A perforated plate can be provided to enclose the rotary joint relative to the environment. The holes in the perforated plate form a guide for the guide rod. For easy installation, the perforated plate can be engaged with the locking cone.

[0015] Optionally, the parking lock has a parking lock housing. The parking lock housing may surround the parking lock from one or more sides. The parking lock housing may hold support elements and additionally perform other functions. For example, the parking lock housing may guide the operating unit, support the locking pawl, and / or house a return spring for the locking pawl.

[0016] A locking pawl is a pawl movable about a pivot point, having locking teeth at its end opposite to the pivot point. These locking teeth allow the locking pawl to be shape-fitted into the tooth profile of a parking lock gear. On the radial side of the parking lock gear opposite to the locking teeth, the locking pawl has a pawl back, which has a pawl profile loaded by the operating unit when the parking lock is engaged. This pawl profile can be formed in a narrow sense, such that it is configured as a raised profile. In a variant, the pawl profile is a flat surface.

[0017] An externally applied force for operating the parking lock is transmitted to the parking lock via an operating unit. The operating unit moves linearly in one direction; typically, this direction is approximately parallel to the locking pawl in its engaged state. This results in a particularly compact parking lock design.

[0018] In most cases, the operating unit is spring-preloaded, allowing the parking lock to be automatically triggered in the event of an electrical fault. The operating unit currently features a locking cone that functions as a slider.

[0019] The locking cone is supported on one side at the pawl profile and on the other side at the parking lock housing or the transmission housing. The support is preferably provided by rollers or balls.

[0020] The vehicle can be a motor vehicle. The vehicle can be a hybrid vehicle or an electric vehicle. The vehicle can have a powertrain with a transmission. The transmission can be housed in the E-axis. The transmission can be a dedicated hybrid transmission. The transmission can be an automatic transmission.

[0021] A parking lock can restrict or prevent a vehicle from leaving its parking position. For example, it can prevent a vehicle parked on a slope from moving. The parking lock can be connected to the transmission. The parking lock can be located within the transmission. The parking lock can be connected to the transmission housing. The parking lock can be connected to the transmission housing, at least via the parking lock housing, for example, by tightening.

[0022] The parking lock can be operated by an actuator. The actuator can be an electric motor, especially a servo motor.

[0023] Other advantages and advantageous designs of the invention are illustrated in the accompanying drawings. Attached Figure Description

[0024] The present invention is described below with reference to the accompanying drawings. Details are shown below:

[0025] Figure 1 A spatial view of the parking lock according to the present invention is shown.

[0026] Figure 2 A schematic diagram showing a longitudinal section of a locking pawl with a guide rod is provided.

[0027] Figure 3 Showing according to Figure 2 A scaled-down 3D view of the device, and

[0028] Figure 4 A longitudinal section is shown through the guide rod with the locking cone. Detailed Implementation

[0029] Figure 1A parking lock 10 is shown, having a locking pawl 12 rotatable about a rotation axis 14. As the locking pawl 12 rotates, a locking tooth 16, integrally formed with it, moves substantially in a radial direction 19 about a transmission main shaft (not shown). The parking lock 10 is designed for insertion into the transmission of a motor vehicle and causes the parking lock gear 56 to be fixed, which is torsionally connected to the transmission main shaft. The parking lock gear 56 has locking teeth provided on its outer circumference, into which the locking teeth 16 can be form-fitted.

[0030] The locking pawl 12 is held by a return spring 28, which prevents the locking pawl 12 from unintentionally locking onto the parking lock gear 56 due to gravity in an unloaded state.

[0031] The parking lock 10 also has a housing wall 20, which is fixed to the transmission housing by means of screws 30. Furthermore, the parking lock 10 includes a support element 18 that accommodates the housing wall 20 and allows for additional clearance compensation.

[0032] The operating unit 24 is associated with the pawl profile 44 of the locking pawl 12, which serves as the mating surface. On the opposite side, the operating unit is supported by a roller 42, which serves as the mating surface. The roller 42 itself is supported on the parking lock housing 21, currently supported on the support element 18. The roller 42 and the pawl profile 44 form a ramp for the operating element 24.

[0033] The operating unit 24 has a guide rod 58 and a locking cone 52, which is linearly movable along an axial direction 26, which extends substantially tangentially relative to the parking lock gear 56. The locking cone 52 is preloaded by a spring element 64 supported on the locking cone 52. To axially secure the locking cone 52 to the guide rod 58, the guide rod has an end flange 66.

[0034] The locking cone 52 is rotatable relative to the guide rod 58. It contacts the guide rod 58 not directly, but via a ball 62. The ball has a central recess 68 as a through-hole for the guide rod 58. The locking cone 52, together with the ball 62, forms a rotary joint 54.

[0035] The locking cone 52 also has a through recess 70 for the guide rod 58, which extends coaxially with the central recess 68. At the end, pointing towards the flange 66, the locking cone is closed by a perforated plate 60, which holds the ball 62 on the locking cone 52. Radially connected to the perforated plate 60, the locking cone 52 has a tapered surface 72 that interacts with the back of a pawl 44 or a roller 42, which together form a ramp for the tapered surface 72. An inclined force is internally compensated by the rotation of the locking cone 52 at the ball 62, the compensation being related to the axial position of the locking cone 52 on the guide rod 58, preventing the guide rod 58 from bending.

[0036] The locking cone 52 can move axially in the axial direction 26 against the restoring force of the spring element 64 via an actuator (not shown). If the locking cone 52 is in the left position with respect to the axial direction 26, then the locking pawl 12 is in the released position (P). If the locking cone 52 moves to the right from the left position, then the locking pawl 12 reaches the locked position. In the locked position, the parking lock 10 is locked.

[0037] List of reference numerals in the attached diagram:

[0038] 10 Parking Lock

[0039] 12 Locking pawl

[0040] 14 Rotation axis

[0041] 16 locking teeth

[0042] 18 Supporting elements

[0043] 19 Radial direction

[0044] 20 Shell wall

[0045] 21 Parking lock housing

[0046] 24 operating units

[0047] 26 Axial direction

[0048] 28. Return spring

[0049] 30 screws

[0050] 42 Rollers

[0051] 44. Racket outline

[0052] 52 Locking Cone

[0053] 54 Rotary Joint

[0054] 56 Parking lock gear

[0055] 58 Guide rod

[0056] 60-hole plate

[0057] 62 balls

[0058] 64 Spring elements

[0059] 66 Flange

[0060] 68 Central fovea

[0061] 70 penetration recess

Claims

1. A parking lock (10) for a motor vehicle transmission, the parking lock having: - A locking pawl (12) rotatable about a rotation axis (14), the locking pawl having locking teeth (16) configured to lock the parking lock gear (56) in the locked position and release the parking lock gear (56) in the unlocked position. - Locking cone (52), by means of which the locking pawl (12) can move to the locking position; - A guide rod (58), on which the locking cone (52) is linearly movable. Its features are, - A rotary joint (54) is provided between the locking tooth (16) and the guide rod (58). The rotary joint (54) is disposed between the locking cone (52) and the guide rod (58) so that the locking cone is rotatable relative to the guide rod.

2. The parking lock according to claim 1, Its features are, The rotary joint (54) has a ball (62).

3. The parking lock according to claim 1, Its features are, The locking cone (52) has a perforated plate (60).

4. The parking lock according to claim 3, Its features are, The perforated plate (60) engages with the locking cone (52).

5. The parking lock according to claim 1, Its features are, The locking cone (52) has an annular cone, which is loaded by two ramps (42, 44).

6. The parking lock according to any one of claims 1 to 5, Its features are, There is full angular compensation in each axial position of the locking cone (52).

7. The parking lock according to any one of claims 1 to 5, Its features are, The locking cone (52) is supported on a support element (18) in the engaged state (P) of the parking lock, the support element being connected to the parking lock housing (21) with a gap.

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