Parking lock for a motor vehicle

Abstract

A parking lock (1) for a motor vehicle, wherein the parking lock (1) has a housing (21), a locking pawl (4) which is arranged such that it can be pivoted about a rotational axis (a) and has a pawl tooth (5) which is configured for engaging in a positively locking manner into a parking lock gear, an actuator (6) for actuating the locking pawl (4), with the result that it can be brought reversibly into engagement with the parking lock gear by way of the pawl tooth (5) of the locking pawl (4), and a movable transmission element which transmits the movement of the actuator (6) to the locking pawl (4). The parking lock (1) has a damping mechanism for the locking pawl or for the movable transmission element.

Claims

1. A parking lock for a motor vehicle, the parking lock comprising: a housing; a locking pawl arranged to pivot about an axis of rotation relative to the housing, the locking pawl including a pawl tooth constructed for positive-fit engagement in a parking lock gear; an actuator that actuates the locking pawl, so that the locking pawl is movable into reversible engagement with the parking lock gear with said pawl tooth; a moving transmission mechanism that transfers movement of the actuator to the locking pawl; and a spring assembly that acts as a stop for the locking pawl or for the moving transmission mechanism, wherein the spring assembly is located between a slide and the housing.

2. The parking lock according to claim 1, wherein the moving transmission mechanism includes a roller that transfers the movement of the actuator to the locking pawl.

3. The parking lock according to claim 1, wherein the moving transmission mechanism has the slide that is displaceable in a linear fashion.

4. The parking lock according to claim 3, wherein a distance of the slide from the spring assembly in a locked state of the parking lock is less than twice a width of the pawl tooth.

5. The parking lock according to claim 1, wherein the spring assembly is arranged between the moving transmission mechanism and the housing.

6. The parking lock according to claim 1, wherein the spring assembly has two or more spring plates arranged one behind the other.

7. The parking lock according to claim 6, wherein at least two of the spring plates have a same shape and are arranged one directly behind the other.

8. The parking lock according to claim 6, wherein at least one of the spring plates has a shape deviating from one of the other spring plates.

9. The parking lock according to claim 6, wherein the spring plates are coated with friction material.

10. The parking lock according to claim 6, wherein the spring plates are spaced apart from each other by spring gaps.

11. A parking lock for a motor vehicle, the parking lock comprising: a housing; a locking pawl arranged to pivot about an axis of rotation relative to the housing, the locking pawl including a pawl tooth constructed for positive-fit engagement in a parking lock gear; an actuator that actuates the locking pawl, so that the locking pawl is movable into reversible engagement with the parking lock gear with said pawl tooth, the actuator including an actuator shaft that is rotatable about an actuator axis; a moving transmission mechanism that transfers movement of the actuator to the locking pawl, the moving transmission mechanism including a crank connected to the actuator shaft, a slide that drives the locking pawl, and a connecting rod connecting the crank to the slide; and a spring assembly that acts as a stop for the locking pawl or for the moving transmission mechanism, wherein slide is displaceable in a linear fashion and a distance of the slide from the spring assembly in a locked state of the parking lock is less than twice a width of the pawl tooth.

12. The parking lock according to claim 11, further comprising a roller located on the slide that transfers movement of the actuator to the locking pawl.

13. The parking lock according to claim 11, wherein the spring assembly is located between the slide and the housing.

14. The parking lock according to claim 13, wherein the spring assembly comprises two or more spring plates.

15. The parking lock according to claim 13, wherein at least two of the spring plates have a same shape and are arranged one directly behind the other.

16. The parking lock according to claim 15, wherein the spring plates are coated with friction material.

17. The parking lock according to claim 15, wherein the spring plates are spaced apart from each other by spring gaps.

18. A parking lock for a motor vehicle, the parking lock comprising: a housing; a locking pawl configured to pivot relative to the housing; an actuator that actuates the locking pawl; a moving transmission mechanism that transfers movement of the actuator to the locking pawl, the moving transmission mechanism including a rod enclosed by a compression spring that pretensions the locking pawl; and a spring assembly separate from the compression spring that acts as a stop for the moving transmission mechanism.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) One embodiment of the invention is shown in the figures. Shown are:

(2) FIG. 1 the essential components of a first parking lock according to the invention without a slide and without a locking pawl in a longitudinal cross section,

(3) FIG. 2 the parking lock according to FIG. 1 with a slide and without a locking pawl in a perspective partial view,

(4) FIG. 3 the parking lock according to FIG. 2 with the additional locking pawl in a perspective view, and

(5) FIG. 4 a part of a second parking lock.

DETAILED DESCRIPTION

(6) In FIGS. 1 to 4, two parking locks 1 are shown, wherein only the essential functional parts are shown. Covers and connecting parts of the arrangement are omitted for reasons of clarity. Below, the features relevant to the invention are described, which are based on a basic structural concept of a parking lock, as explained in detail in the applicant's publications, DE 10 2010 053 857 A1 and DE 10 2011 080 498 A1, named above. Reference is made to these previously known solutions explicitly to avoid repetitions with respect to the basic functioning principle of a parking lock.

(7) In general, the parking lock 1 comprises a locking tooth arrangement 2 that has a number of recesses 3 on its periphery. The other central component of the parking lock 1 is a locking pawl 4 that is arranged so that it can pivot about an axis of rotation a.

(8) In FIG. 4, the locking pawl 4 is shown in a position pointed downward (in the direction toward the locking tooth arrangement 2), in which a pawl tooth 5 of the locking pawl 4 engages in one of the recesses 3 of the locking tooth arrangement 2 and thus locks the arrangement.

(9) The locking or unlocking of the parking lock 1 is realized by an actuator 6 that is here shown as a shaft that rotates about an axis of rotation c for the locking or unlocking.

(10) The transfer of the movement of the actuator 6 to the locking pawl 4 is realized by means of a transmission element 7. Like in the mentioned previously known solutions, the transmission element 7 comprises a linear displaceable slide 12 in which three rollers 13, 14, and 15 are supported.

(11) The roller 13 can here contact a ramp 17 (see FIG. 1), which is constructed on the locking pawl 4. Thus, if the slide 12 carries out a linear movement, the locking pawl 4 pivots.

(12) In the case of FIG. 4, the transmission element 7 comprises a crank drive 8 with which a part 9 of the transmission element 7 can be moved in a linear fashion. Between the part 9 and the slide 12 there is a rod 16, so that a linear movement of the part 9 is transferred to the slide 12. The rod 16 is enclosed by a compression spring 20 that pretensions the locking pawl 4 and holds it in the locked position. The crank drive 8 here has a crank 10 and a connecting rod 11 that are connected to each other in an articulated fashion. The crank 10 is locked in rotation with the actuator 6. The connecting rod 11 is connected to the part 9 in an articulated fashion.

(13) If the actuator 6 is now operated, i.e., it performs a rotation about the axis c, the crank 10 moves accordingly and pulls the connecting rod 11 with it. Now, with the crank drive 8, for a small, equal torque on the actuator 6, a large force can be realized for unlockingdue to the properties of a crank drivewithout reducing the total displacement path. The force then decreases for increasing displacement angle or path, which, in this case, however, is not a problem, because a large force is only required at the beginning until (in this case) the roller 13 has reached the high point of the ramp 17 of the locking pawl 4 and in this way the locking of the locking pawl is undone by the roller 13.

(14) As can be seen from FIG. 4, the pivot axis b of the hinge-like connection between the crank 10 and the connecting rod 11 points in the vertical direction, while the axis of rotation a of the locking pawl 4 points in the horizontal direction. If the pivot axis b is projected onto the axis of rotation a, these two axes are aligned at a right angle to each other.

(15) As can be seen especially from FIG. 1, the roller 13 rolls on the locking pawl 4, while the rollers 14, 15 roll on a reinforcement 27. The reinforcement 27 is constructed as a flat, hardened steel sheet and contacts, on the back side, the housing 21 of the parking lock 1.

(16) In the illustrated embodiment, the two housing-side rollers 14, 15 are supported by needle rollers for minimizing the friction and form support rollers. The third roller 13 that rolls on the locking pawl is a solid roller.

(17) The rollers are integrated in a slide 12. The slide 12 has two elongated side parts 22, 23 that are preferably constructed as stamped sheet-metal parts. Both side parts 22, 23 are connected on the ends by two transverse parts 24, 25. The transverse parts 24, 25 are also advantageously produced as stamped sheet-metal parts. The side parts 22, 23 and the transverse parts 24, 25 can be riveted to each other.

(18) The slide 12 carries a drive tooth segment 26 and guide rollers 28. The guide rollers 28 are placed so that they are in the optimal flow of forces to the drive pinion of the actuator 6.

(19) The box-like slide 12 further has the compression spring 20 that is guided on the drive tooth segment 26. It also holds the shafts of the support rollers 14, 15 and guides these in the axial direction.

(20) A distance (D) of the slide 12 from the spring assembly 42 in a locked state of the parking lock is less than twice a width (W) of the pawl tooth 5.

(21) Between the housing 21 of the parking lock 1 and the slide 12, two spring plates 40, 41 form, as spring assembly 42, an end stop for the slide 12 on the housing 21 or the locking pawl 4. The two spring plates 40, 41 are tensioned in the housing 21. They have a convex shape and can deform when the slide 12 contacts, so that they can convert its motion energy by deformation and thus internal friction into heat and thus form a damping mechanism. The two spring plates 40, 41 are spring-mounted in the present example on their side on a third spring plate 43.

LIST OF REFERENCE SYMBOLS

(22) 1 Parking lock 2 Locking tooth arrangement 3 Recess 4 Locking pawl 5 Pawl tooth 6 Actuator 7 Transmission element 8 Crank drive 9 Part of the transmission element 10 Crank 11 Connecting rod 12 Slide 13 Roller 14 Roller 15 Roller 16 Rod 17 Ramp 20 Compression spring 21 Housing 22 Side part 23 Side part 24 Transverse part 25 Transverse part 26 Drive tooth segment 27 Reinforcement 28 Guide roller 29 Pawl recess 30 Engagement mechanism 31 Blocking mechanism 32 Ball 40 First spring plate 41 Second spring plate 42 Spring assembly 43 Third spring plate a Axis of rotation of the locking pawl b Pivot axis of the connection between the crank and connecting rod c Axis of rotation of the actuator