CN114135667A

CN114135667A - Parking lock

Info

Publication number: CN114135667A
Application number: CN202110918199.6A
Authority: CN
Inventors: 克里斯托夫·蒂劳夫; 托比亚斯·基希格斯纳; 马赛厄斯·费尔巴哈
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2020-09-03
Filing date: 2021-08-11
Publication date: 2022-03-04
Also published as: DE102020122986A1

Abstract

The invention relates to a parking brake (10) for a motor vehicle transmission, comprising: a locking pawl (12) which is rotatable about a rotational axis (14) and has a locking tooth (16) which is designed to lock the parking lock gear (56) in a locked position and to release the parking lock gear (56) in an unlocked position; a locking cone (52) by means of which the locking pawl (12) can be moved into a locking position; and a guide rod (58) on which the locking cone (52) is arranged in a linearly movable manner. A rotary joint (54) is provided between the locking tooth (16) and the guide rod (58).

Description

Parking lock

Technical Field

The invention relates to a parking brake, comprising: a locking pawl which is rotatable about a rotational axis and has a locking tooth which is designed to lock the parking brake gear in a locked position and to release the parking brake gear in an unlocked position; a locking cone via which the locking pawl can be moved into a locking position; and a guide rod on which the locking cone is linearly movably disposed.

Background

A parking lock is known, for example, from DE 10144063 a 1. A parking lock in an automatic transmission of a motor vehicle is described, which has a locking ring with a locking recess provided on a transmission shaft. By means of a pivotable selector lever and a connecting rod articulated thereon, the pawl is engaged with the locking recess in the locked state of the device. The connecting rod has rollers at its ends, a second of which guides the connecting rod in an L-shaped guide plate. The guide plate is fixed in a housing of the automatic transmission. The second roller rolls on the guide plate when the connecting rod moves longitudinally. The guide plate comprises a side wall and a horizontally extending wall. The horizontally extending wall of the guide rod has an elongated hole. The side walls of the guide plates are separate members and have at the edges crenellated projections. The projection is matched with respect to its dimensions to the elongated hole of the horizontally extending wall and can be engaged by means of a press fit into the opening of the horizontal wall.

Other parking locks are known from CN 104534087 a and DE 10144058A 1. The latter shows such a parking lock. The parking lock having the lock pawl and the operating unit is mounted in a manner fixed to the transmission case, whereby the parking lock gear provided on the powertrain can be supported. The tolerances, which must be compensated, are derived from the different fixed reference points. In particular, dimensional fluctuations occur for production reasons between the centering bore in the housing and the contact surface of the actuating unit that moves the locking pawl. When the parking brake is installed, an adjustment is therefore always carried out in order to precisely position the pawl with respect to the parking brake gear. The transfer of the actuating operation from the parking brake gear/locking pawl interface to the locking pawl/locking pawl actuator interface is conceivable, but nevertheless results in the following disadvantages: the parking brake with its actuator, which is for example an electric motor, cannot be provided as a prefabricated module, which in turn increases the assembly effort.

DE 102018131263B 4 proposes a movable plate which is inclined in order to be able to compensate for manufacturing tolerances. By introducing the load when the pawl is in contact and introducing the load at the transmission housing/plate contact to two non-opposing contact points of the blocking element, the blocking element can tilt until the two contact force vectors meet again on the center axis of the blocking element. It has proven to be insufficient in any case for this type of tolerance compensation. Due to the usually guided locking elements on the guide rods and the insufficient freedom available between them, the angular compensation cannot be realized over the entire circumference. Thus, the locking element is supported on the guide rod, the load is introduced and the guide rod bends. This results in a significant limitation of the function of the parking lock.

Disclosure of Invention

The object of the invention is to improve a parking brake and to avoid the above-mentioned disadvantages.

This object is achieved by a parking lock having the features of the invention.

The parking lock according to the invention has a rotary joint which is arranged between the locking tooth and the guide rod. "between … …" is understood herein in a functional sense. Additionally, a space entity arrangement can also be provided between the components. If the load is supported in the housing in the parking lock via contact points offset from one another, the rotary joint rotates so that the acting force vectors meet at the locking element on its central axis and no torque can be generated. Tilting is thus already prevented at the outset, so that the adjacent components, in particular the guide rods, are no longer bent.

Contrary to the solutions in the prior art, the rotary joint not only enables a large clearance compensation, but also causes said clearance compensation in different directions.

In a first embodiment of the invention, the rotary joint performs an angular compensation both in the locked position and over the region of the locking cone at the possible position. Ideally, the angular compensation takes place over the entire path of movement of the blocking element from the disengaged position "nP" up to the engaged position "P". Thereby, the maximum load of the parking lock member is reduced, so that the parking lock can be constructed more lightweight and smaller.

In a further embodiment, the rotary joint is arranged between the locking cone and the guide rod. Thereby, no adjustment of the locking pawl is required, so that the locking pawl can be produced in one piece as in the prior art.

If the rotary joint is able to compensate the angle directly in the locking cone over the entire engagement and disengagement process of the parking lock, it is ensured that: the two active contact force vectors at the locking element always meet at the center axis of the locking element and cannot cause a torque.

The rotary joint can also realize that: the required adjustment work is transferred from the locking pawl/parking brake gear interface into the parking brake. In addition, the locking cone can be supported in the locked position on a support element, which is connected with clearance to the parking lock housing. The gap is selected here such that typically occurring manufacturing tolerances can be compensated by this gap. The "floating" arrangement of the support element within the boundaries therefore introduces an additional degree of freedom which allows an internal compensation of manufacturing tolerances. The self-adjusting, automatic orientation of the support element thereby allows the entire parking brake to be installed as a pre-produced unit without the need to compensate for production inaccuracies during installation. Rather, it is additionally possible by means of the self-adjustment that the parking brake can be installed in the operating position nP, since tolerance compensation is also possible when the parking brake pawl is actuated.

The rotary joint can in the simplest case be designed as a ball which is supported on the guide rod. The ball has a central hole for guiding the rod. A locking cone is provided on the ball so that a compact unit is present. The locking cone may in this case form a housing or a bearing cage for the ball. The locking cone thus slides on the ball surface and ensures angular compensation.

An orifice plate can be provided to enclose the rotary union with respect to the environment. The bore of the perforated plate forms a lead-through for the guide rod. For simple assembly, the perforated plate can be engaged on the locking cone.

Optionally, the parking lock has a parking lock housing. The parking lock housing may enclose the parking lock from one or more sides. The parking lock housing can hold the support element and additionally assume further functions. For example, the parking lock housing may guide the operating unit, support the locking pawl and/or accommodate a return spring for the locking pawl.

The locking pawl is a pawl which is movable about a rotation point and has a locking tooth at its end facing away from the rotation point, by means of which the locking pawl can be positively locked into a tooth profile provided on the parking lock gear. On the side of the parking brake gear facing radially away from the locking tooth, the locking pawl has a pawl back with a pawl contour which is acted upon by the operating unit when the parking brake is engaged. The detent contour can be formed as a narrow contour, so that it is formed as a contour projection. In one variant, the detent profile is a flat face.

By means of the operating unit, an externally introduced force for operating the parking brake is transmitted to the parking brake. Here, the operation unit is linearly moved in one direction; typically, the direction is substantially parallel to the locking pawl in its engaged state. This results in a parking brake which is particularly compact.

In most cases, the operating unit is spring-biased, so that in the event of an electrical failure, the parking brake can be automatically triggered. The operating unit currently has a locking cone as a slide.

The locking cone is supported on the one hand at the pawl contour and on the other hand at the parking lock housing or at the transmission housing. The support is preferably via rollers or balls.

The vehicle may be a motor vehicle. The vehicle may be a hybrid vehicle or an electric vehicle. A vehicle may have a powertrain with a transmission. The transmission may be incorporated into the E-shaft. The transmission may be a dedicated hybrid transmission. The transmission may be an automatic transmission.

The park lock may limit or prevent movement of the vehicle out of the park position. For example, the movement of the vehicle stopped on a slope can be prevented. The parking brake may be connected to the transmission. The parking lock may be provided in the transmission. The parking brake may be connected to a transmission housing of the transmission. The parking brake may be connected, for example screwed, to the transmission housing at least via the parking brake housing.

The parking lock may be operated by an actuator. The actuator may have an electric motor, in particular a servomotor.

Further advantages and advantageous embodiments of the invention result from the description of the figures and the drawings.

Drawings

The invention is described hereinafter with reference to the accompanying drawings. Showing in detail:

figure 1 shows a spatial view of a parking lock according to the invention,

figure 2 shows a schematic view of a longitudinal section of a locking pawl with a guide rod,

fig. 3 shows a reduced perspective view of the device according to fig. 2, an

Fig. 4 shows a longitudinal section through a guide rod with a locking cone.

Detailed Description

Fig. 1 shows a parking brake 10 having a locking pawl 12 which is rotatable about an axis of rotation 14. When the locking pawl 12 rotates, the locking tooth 16 formed integrally therewith moves substantially in a radial direction 19 (with respect to the main shaft of the transmission (not shown)). The parking brake 10 is provided for installation in a vehicle transmission of a motor vehicle and causes a fixing of a parking brake gear 56, which is connected in a rotationally fixed manner to a transmission main shaft. For this purpose, the parking brake gear 56 has a locking tooth system provided on its outer circumference, into which the locking teeth 16 can be positively locked.

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

The parking brake 10 furthermore has a housing wall 20, which is fastened to the transmission housing by means of screws 30. Furthermore, parking brake 10 comprises a support element 18, which accommodates a housing wall 20 and via which a play compensation can additionally be carried out.

The operating unit 24 is associated with a pawl contour 44 of the locking pawl 12 as an abutment surface. On the opposite side, the operating unit is supported via rollers 42 as mating abutment surfaces. The roller 42 is itself supported on the parking lock housing 21, in the present case on the support element 18. The roller 42 and the detent profile 44 form a ramp for the operating element 24.

The operating unit 24 has a guide rod 58 and a locking cone 52 which is linearly movable in an axial direction 26 which runs substantially tangentially with respect to the parking lock gear 56. The locking cone 52 is prestressed by a spring element 64, which is supported on the locking cone 52. In order to fix the locking cone 52 axially on the guide rod 58, the guide rod has an end-side flange 66.

The locking cone 52 is rotatable relative to the guide bar 58. In this case, it is not in contact with the guide bar 58 directly, but via the ball 62. The ball has a central recess 68 as a lead-through for the guide rod 58. The locking cone 52 together with the ball 62 form the rotary joint 54.

The locking cone 52 likewise has a through-recess 70 for the guide rod 58, which extends coaxially with the central recess 68. The end face points toward the flange 66, the locking cone is closed by an orifice 60, which holds the ball 62 on the locking cone 52. Radially connected to the perforated plate 60, the locking cone 52 has a conical surface 72, which interacts with the pawl back 44 or the roller 42, which form a ramp for the conical surface 72. The obliquely introduced force causes an internal compensation via the rotation of the locking cone 52 at the ball 62, which is dependent on the axial position of the locking cone 52 on the guide rod 58, so that the guide rod 58 itself does not bend.

The locking cone 52 is axially displaceable in the axial direction 26 via an actuator, not shown, against a restoring force of the spring element 64. If the locking cone 52 is in the left position with respect to the axial direction 26, the locking pawl 12 is in the release position (P). If the locking cone 52 is moved to the right from the left position, the locking pawl 12 reaches the locking position. In the locked position, the parking brake 10 is locked.

List of reference numerals:

10 parking lock

12 locking pawl

14 axis of rotation

16 locking tooth

18 support element

19 radial direction

20 casing wall

21 parking lock casing

24 operating unit

26 axial direction

28 return spring

30 screw

42 roller

44 pawl profile

52 locking awl

54 rotary joint

56 parking lock gear

58 guide rod

60 orifice plate

62 ball

64 spring element

66 flange

68 central recess

70 through recess

Claims

1. Parking lock (10) for a motor vehicle transmission, having:

-a locking pawl (12) rotatable about a rotation axis (14), the locking pawl having a locking tooth (16) configured for, in a locked position, locking a parking lock gear (56) and, in an unlocked position, releasing the parking lock gear (56);

-a locking cone (52) by means of which the locking pawl (12) is movable into the locking position;

a guide rod (58) on which the locking cone (52) is arranged in a linearly movable manner,

it is characterized in that the preparation method is characterized in that,

-a swivel joint (54) is provided between the locking tooth (16) and the guide bar (58).

2. The parking lock according to claim 1,

it is characterized in that the preparation method is characterized in that,

the rotary joint (54) is arranged between the locking cone (52) and the guide rod (58).

3. Parking lock according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the rotary joint (54) has a ball (62).

4. Parking lock according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the locking cone (52) has an orifice plate (60).

5. The parking lock according to claim 4,

it is characterized in that the preparation method is characterized in that,

the orifice plate (60) engages the lock cone (52).

6. The parking lock according to claim 1,

it is characterized in that the preparation method is characterized in that,

the locking cone (52) has an annular cone which is acted upon by two ramps (42, 44).

7. Parking lock according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

in each axial position of the locking cone (52), there is a complete angular compensation.

8. Parking lock according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the locking cone (52) is supported in the engaged state (P) of the parking lock on a support element (18) which is connected with a gap to a parking lock housing (21).