DE102015200978A1 - Parking lock actuator for a Parsperre a motor vehicle automatic transmission - Google Patents

Abstract

The invention relates to a parking brake actuator for a parking brake of a motor vehicle automatic transmission, comprising a parking lock pawl which engages or disengages in a connected to the output of the transmission parking lock gear, one on a connecting rod (1) and a spring element (3) sprung locking element ( 2) which is clamped in the locked state between the parking pawl and a guide plate to prevent forcing out the parking pawl of a tooth space of the parking lock gear, wherein the parking lock is mechanically inserted according to the NC principle, wherein the Parksperrenaktuator one for laying out the parking lock electrically Bestrombare delivery device (5), which is operatively connected to the connecting rod (1) via a in the power flow between the delivery device (5) and the connecting rod (1) Auslegefederelement (6), wherein the Auslegefederelement (6) designed as a leg spring and in a raced Scheib e is integrated, which is made in two parts and a first and a second detent disc (7, 8), which are arranged on a shaft (9), wherein the first detent disc (7) rotatably connected to the shaft (9) and the second detent disc (8) has a predetermined freewheel in the direction of rotation in the operating direction of the parking brake along the outer diameter of the shaft (9), wherein the connecting rod (1) on the second detent disc (8) is articulated and the first detent disc (7) with a lever ( 20) and a screw (13) for emergency release and operatively connected to a piston rod (14) of the delivery device (5), wherein the first detent disc (7) upon actuation of the parking brake in the opening direction of the parking lock relative to the second detent disc (8) in Is sense of charging the leg spring (6) is rotatable and wherein the second detent disc for realizing the freewheel one viewed radially in the direction of the central longitudinal axis of the W. and the lever (9) on which it is mounted has an extending projection (15) arranged in a ring - segment - shaped groove (12) of predetermined size, so that a freewheeling in the direction of rotation between the ends of the ring - segment - shaped groove (12) along the outer diameter of the Shaft (9) is realized.

Description

The present invention relates to a parking brake actuator for a parking brake of a motor vehicle automatic transmission according to the preamble of patent claim 1.

Parking brake mechanisms for automatic transmissions are known from the prior art. Usually, such mechanisms have a preloaded spring over which the parking brake is activated, wherein the parking lock function is realized via a locking pawl system. To deactivate the parking lock, a mechanical linkage or a hydraulically or pneumatically actuated piston is usually used. Here, an actuating rod of a linkage or a piston rod of the piston, which in turn is arranged axially displaceably in a piston bore of an actuator housing, interacts with a parking pawl and a parking lock gear.

The usually designed as a locking cone locking element such parking lock mechanisms is usually trapped in the locked state between a parking pawl and a guide plate to prevent the parking pawl is pushed out of the tooth gap of a connected to the output of the transmission parking lock gear.

Parking locks in automatic transmissions, which have no mechanical connection, for example via a detent disk to the shift or selector lever in the vehicle interior, are usually actuated hydraulically. When hydraulically performed Auslegevorgang the parking brake a locking cone is pulled out of the restricted area between the guide plate and parking pawl, wherein the locking cone is spring-loaded and operatively connected via a push rod with the actuating piston of the hydraulic. The springing of the pawl also allows in the event that the ratchet teeth of the parking pawl rests on a tooth of the parking lock gear, a hydraulic activation of the parking brake, even before the parking pawl engages in the parking lock gear.

From the DE 41 27 991 C2 The Applicant discloses a parking lock for automatic transmissions in motor vehicles with a switchable by a manual selector hydraulic or pneumatic parking lock mechanism, the parking brake mechanism having a sliding actuating rod which cooperates with a parking pawl and a parking lock gear. Here, the actuating rod is at the same time the piston rod arranged in the interior of a transmission case, single-acting piston, which pushed the actuating rod in the pressureless state and thus keeps the parking brake closed and this opens when pressurized.

From the DE 102 453 69 A1 the applicant is an electro-hydraulic actuator for a parking brake of an automatic transmission known in which the parking brake is mechanically engaged via a spring accumulator and designed hydraulically via a piston of a Parksperrenaktuators. In this known actuator, a pump is provided which maintains the pressure supply of the Parksperrenaktuators after switching off a drive motor of the transmission.

From the DE 101 364 25 B4 Another device for actuating a parking brake of a motor vehicle is known, comprising a pressure source and a Parksperrenaktuator with a hydraulically actuated piston, which is operatively connected to the parking brake to actuate. The piston can be pressurized on both sides. As a result, an unintentional actuation of the parking brake caused, for example, by a pressure drop should be avoided.

When the parking lock is laid out under load, which is e.g. the case is when the vehicle is on a slope, a high force is required for the deployment process, i. the pressure in the actuating cylinder of the parking lock mechanism increases until the force is sufficient to interpret the locking cone, which is clamped between the parking pawl and a guide plate.

As soon as the locking cone, which holds the parking pawl in the tooth space of a parking lock wheel connected to the output of the transmission, leaves the blocking edge on the guide plate or on the parking pawl during the laying process, the self-locking is lost, resulting in a sudden relaxation of the system. In this case, the hydraulic pressure in the actuating cylinder decreases, because a counterforce is missing, whereby the piston continues to move in accordance with the existing fluid or oil volume flow. After the locking cone has left the blocking area, the speed of movement of the piston depends on the available volume flow in the bore. This volume flow in turn depends on the viscosity and the density of the fluid, on the effective line cross-sections and flow-mechanically effective diaphragms, and on the delivery rate of the gear pump. Thus, the volume flow is limited and can not be increased quickly enough in the short term to the needs required in certain cases.

After laying out the parking lock, the parking pawl moves very fast towards the locking cone and guide plate. The The parking pawl pushes the poppet back at high speed, with the pawl plunging into the pawl spring suspension, with the result that the pawl initially exits the pawl wheel completely.

When the directional force of the parking pawl directed towards the parking brake has been absorbed by the pawl spring suspension, the pawl moves back from the reverse pawl stop to engage the parking brake due to the spring energy now stored in the pawl spring suspension from its immersion. Has until this time, the piston of the Parksperrenaktuators due to the physically limited volume flow not covered enough way, the Sperrkegelanfederung the locking cone, which is operatively connected via a connecting rod with the piston, move back so far in the direction of insertion, that there is an undesirable touch of the pawl comes with the parking pawl. This re-touching the pawl with the parking pawl is undesirable because in this way the parking pawl may be raised again, which then leads to an undesirable, wear-prone contact between the parking pawl and the Parksperrenrad. The latter is also referred to as "ratcheting the parking pawl on Parksperrenrad".

In the event that the drive train is heavily biased, for example, when the vehicle is on a slope, depending on the rigidity of the entire drive train, the output shaft is biased by a certain angle. This preload is released suddenly when laying out, which leads briefly to very high angular velocities on the parking lock gear.

From the DE 198 37 832 A1 The applicant is a parking brake is known, which blocks or releases an automatic transmission due to a triggered by the driver via an operating device an automatic transmission by a parking pawl, which via a device with discs, namely a detent disc and an emergency release disc, and with a detent in conjunction with an actuating device, consisting of a piston, a cylinder and a return spring, is moved, wherein the parking pawl can be moved manually via an operative connection from a vehicle compartment or hydraulically via an actuating device. In the known parking brake is provided that disengaged by turning the device about the central axis by pressurizing an actuator, the parking pawl while bringing a detent in an open state and by depressurizing an actuator, the device is rotated in the opposite direction about its central axis and while the park pawl engages.

The present invention has for its object to provide a Parksperrenaktuator for a parking brake of a motor vehicle automatic transmission.

This object is achieved by a Parksperrenaktuator with the features of claim 1. Further embodiments of the invention will become apparent from the dependent claims.

Accordingly, a Parksperrenaktuator is proposed for a parking brake of a motor vehicle automatic transmission, which comprises a parking pawl which engages in a connected to the output of the transmission parking lock gear, and which comprises a arranged on a connecting rod and spring-loaded by a spring element, which in locked state between the parking pawl and a guide plate is clamped to prevent a pushing out of the parking pawl from a tooth space of the parking lock gear. The blocking element may for example be designed as a locking cone. The parking brake is mechanically inserted by means of an inserting device, which is preferably designed as a spring element, wherein the parking brake according to the NC (Normally Closed) principle is energized.

According to the invention, the Parkperrenaktuator on a laying out the parking lock electrically energizable delivery device that generates an actuating force profile via an electromagnet or has an electric motor, which is operatively connected to the connecting rod via a arranged in the power flow between the delivery device and the connecting rod Auslegefederelement.

The Auslegefederelement is designed as a leg spring and integrated into a detent disk, wherein the detent disk is made in two parts and having a first and a second detent disc, which are arranged on a shaft, wherein the first detent disc is rotatably connected to the shaft and the second detent disc a predetermined Freewheel in the direction of rotation in the operating direction of the parking lock along the outer diameter of the shaft and wherein one leg of the designed as a leg spring Auslegefederelementes with the first detent disc and the other leg is operatively connected to the second detent disc.

The second detent disk has to realize the freewheel radially extending in the direction of the central longitudinal axis of the shaft on which it is mounted, extending projection, which is arranged in a ring-segment-shaped groove of predetermined size, so that a freewheel in the direction of rotation is realized between the ends of the annular segment-shaped groove along the outer diameter of the shaft.

According to the invention, the connecting rod is articulated to the second detent disk, wherein the first detent disk is operatively connected to a lever and an emergency release bolt and articulated to a piston rod of the deployment device, the first detent disk being actuated relative to the second one upon actuation of the parking brake in the opening direction of the parking lock Notched disk in the sense of a charge of designed as a leg spring Auslegefederelementes is rotatable.

According to the invention, an operating point shift of the electrically energizable delivery device is achieved by the delivery spring element arranged in the force flow between the delivery device and the connecting rod, so that it can be designed to save space and with low power consumption.

At the beginning of the deployment process of the parking brake, the piston rod of the electrically powered delivery device moves a predetermined part of the total stroke against the force of Auslegefederelementes, whereby the Auslegefederelement serves as a rotatory energy storage and is charged. During this time, the parking brake is still engaged. Once the Auslegefederelement reaches the required Auslegekraft for the engaged parking brake, the parking brake is designed abruptly, while the piston rod of the electrically energized Auslegevorrichtung moves the rest of the stroke. As a result, an extremely high deflection speed of the blocking element is achieved.

Due to the freewheeling of the second detent disc, a pulse is also generated during the deployment process of the parking brake, which supports the Auslegevorgang. By the operation of the parking brake in the opening direction, the first detent disk is rotated relative to the second detent disc in the sense of a charge of Ausleger designed as a leg spring Auslegefederelementes, wherein when a predetermined charge of the leg spring is achieved on the operatively connected to the connecting rod second detent disc through the relative rotational movement of the shaft is transmitted to the fixed with the parking brake second detent disc conditional pulse due to the achievement of the corresponding stop of the freewheel. The degree of charging of the leg spring, i. The leg spring force at the time of impulse transmission can be determined by the dimensioning of the ring-segment-shaped groove of the freewheel.

If the momentum transfer occurs before the leg spring force is sufficient to overcome the self-locking force, i. has reached the required Auslegekraft, the pulse must be so high dimensioned that the parking brake is designed securely. The required disengagement force is determined on the basis of a worst-case scenario, which corresponds to laying out the parking lock of a heavy SUV vehicle on a slope.

If, due to the dimensioning of the ring segment-shaped groove of the freewheel, the momentum transfer takes place after the leg spring force has reached the required disengagement force, this means that the impulse, if a given required disengagement force is not exceeded, will never be transmitted; the parking brake is laid out via the extension spring. Accordingly, the impulse is to be understood as security. If the parking lock requires a higher leveling force than specified, then in addition to the deflection spring force, the impulse is transmitted, which interprets the parking lock via an additional force peak.

When the momentum transfer occurs, when the leg spring force reaches the required disengagement force, the disengagement speed of the parking lock is increased.

The conception according to the invention ensures that the parking lock is reliably and quickly designed using an electrically powered delivery device.

The invention will be explained in more detail below with reference to the accompanying figures, by way of example. Show it:

1 a schematic perspective view of a parking brake with a running according to the invention Parkperrenaktuator;

2 : a schematic side view of in 1 shown parking lock in the engaged state;

3 : a schematic side view of in 1 shown parking lock at the beginning of the deployment process;

4 : a schematic side view of in 1 shown parking lock at the time of pulse transmission;

5 : a schematic side view of in 1 shown parking lock in the designed state; and

6 : a schematic side view of in 1 shown parking lock along the Central longitudinal axis of the electrically powered delivery device.

In the accompanying 1 is with the reference numeral 1 a connecting rod, wherein at one end of the connecting rod 1 a via a spring element 3 Sprung locking element 2 is arranged, which is clamped in the locked state between a parking lock pawl, not shown, and a guide plate, not shown, to prevent forcing out the parking pawl of a tooth space of the parking lock wheel, not shown. The parking lock is by means of an inserting device, which acts as a spring element 4 is executed, according to the NC principle mechanically inserted.

The Parksperrenaktuator has a laying out the parking brake electrically energizable delivery device 5 on, which generates a force profile in the example shown via a pot magnet, with the connecting rod 1 via a force flow between the delivery device 5 and the connecting rod 1 arranged deployment spring element 6 is actively connected. Furthermore, in the example shown, a locking unit 16 provided which can latch the states "inserted" and "designed"; this engages a Rastierelement 18 in locking grooves which in 2 - 6 with the reference number 17 are provided.

As 1 it can be seen, is the Auslegefederelement 6 designed as a leg spring and integrated into a detent disk, wherein the detent disk is made in two parts and a first and a second detent disc 7 . 8th that is on a shaft 9 are arranged, wherein the first detent disc 7 rotatably with the shaft 9 is connected and the second detent disc 8th a predetermined freewheel in the direction of rotation in the operating direction of the parking lock along the outer diameter of the shaft 9 and wherein a leg 10 designed as a leg spring Auslegefederelementes 6 with the first notch 7 and the other thigh 11 with the second detent disc 8th is actively connected.

According to the invention, the connecting rod 1 at the second detent disc 8th hinged, with the first detent disc 7 with a lever and a screw 13 operatively connected to the emergency release and with a piston rod or sliding sleeve 14 the delivery device 5 hingedly connected, wherein the first detent disc 7 upon actuation of the parking brake in the opening direction relative to the second detent disc 8th in the sense of a charge of designed as a leg spring Auslegefederelementes 6 is rotatable.

To realize the freewheel, the second detent disc 8th a radially viewed in the direction of the central longitudinal axis of the shaft 9 on which it is mounted, extending projection in a ring segment-shaped groove 12 is arranged predetermined size, so that a freewheel in the rotational direction between the ends of the annular segment-shaped groove, which serve as stops, along the outer diameter of the shaft 9 is realized. The lead is in the 2 - 5 , which illustrate the operation of the Parksperrenaktuators invention, denoted by the reference numeral 15 Mistake.

In 2 is a parking brake comprising a executed in accordance with the invention Parksperrenaktuator shown in the inserted state, wherein 3 represents the parking lock at the beginning of the laying process. This has due to the operation of the electrically powered delivery device 5 , which is designed in the example shown as a pot magnet, the piston rod or sliding sleeve 14 axially moved to the right, causing the shaft 9 rotatably connected first detent disc 7 relative to the second detent disc 8th in the sense of a charge of designed as a leg spring Auslegefederelementes 6 rotated by an angle; the parking lock is still engaged, leaving the second detent disc 8th not been turned. Furthermore, the locking of the state "parking brake engaged" is canceled.

At a later date and referring to 4 have due to the operation of the electrically powered delivery device 5 the wave 9 and those with the wave 9 rotatably connected first detent disc 7 relative to the second detent disc 8th in the sense of a charge of designed as a leg spring Auslegefederelementes 6 turned to another angle, taking on the with the connecting rod 1 operatively connected second detent disc 8th a by the relative rotational movement of the shaft 9 for fixed with parking brake second detent disc 8th Conditional pulse is transmitted due to the achievement of the corresponding stop of the freewheel.

Immediately after the pulse transmission, the parking lock is designed in the example shown, as shown 5 illustrated; through the locking unit 16 is the state "parking lock designed" rastiert.

Based on the schematic side view of in 1 shown parking lock along the central longitudinal axis of the electrically powered delivery device 5 according to 6 the possibility of emergency release by means of one with the first detent disc 7 connected levers 20 that's about a screw 13 is operable, even with locked state "parking brake engaged" illustrated. To ensure an emergency release is in the Piston rod or sliding sleeve 14 the delivery device 5 a transverse groove 19 provided that an axial movement of the lever 20 in the direction of the delivery device 5 and thus a rotational movement of the shaft 9 and the one with the wave 9 rotatably connected first detent disc in the opening direction of the parking brake even with engaged engaged parking brake and non-functioning delivery device 5 allows.

LIST OF REFERENCE NUMBERS

1

connecting rod

2

blocking element

3

spring element

4

spring element

5

A display device

6

Auslegefederelement, leg spring

7

first notch

8th

second detent disc

9

wave

10

Leg of the Auslegefederelementes 6

11

Leg of the Auslegefederelementes 6

12

ring segment-shaped groove

13

Emergency release screw

14

sliding sleeve 14 the delivery device 5

15

head Start

16

locking unit

17

locking groove

18

detent element

19

transverse groove

20

Emergency release lever

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4127991 C2 [0005]
• DE 10245369 A1 [0006]
• DE 10136425 B4 [0007]
• DE 19837832 A1 [0013]

Claims (6)

A parking brake actuator for a parking brake of a motor vehicle automatic transmission, comprising a parking pawl which engages or disengages into a parking lock wheel connected to the output of the transmission, a parking brake on a connecting rod ( 1 ) and via a spring element ( 3 ) sprung locking element ( 2 ), which is clamped in the locked state between the parking pawl and a guide plate to prevent forcing out the parking pawl of a tooth space of the parking lock gear, wherein the parking lock is mechanically inserted according to the NC principle, wherein the Parksperrenaktuator one for laying out the parking lock energetically energized Delivery device ( 5 ), which with the connecting rod ( 1 ) via a force flow between the delivery device ( 5 ) and the connecting rod ( 1 ) arranged Auslegefederelement ( 6 ) is operatively connected, wherein the Auslegefederelement ( 6 ) designed as a leg spring and is integrated in a detent disk, which is made in two parts and a first and a second detent disc ( 7 . 8th ) mounted on a shaft ( 9 ) are arranged, wherein the first detent disc ( 7 ) rotatably with the shaft ( 9 ) and the second detent disc ( 8th ) a predetermined freewheel in the direction of rotation in the operating direction of the parking brake along the outer diameter of the shaft ( 9 ), wherein a leg ( 10 ) of the leg spring ( 6 ) with the first detent disc ( 7 ) and the other leg ( 11 ) with the second detent disc ( 8th ) is operatively connected, wherein the connecting rod ( 1 ) on the second detent disc ( 8th ) and the first detent disc ( 7 ) with a lever ( 20 ) and a screw ( 13 ) operatively connected to the emergency release and with a piston rod ( 14 ) of the delivery device ( 5 ) is hinged, wherein the first detent disc ( 7 ) on actuation of the parking brake in the opening direction of the parking lock relative to the second detent disc ( 8th ) in the sense of charging the leg spring ( 6 ) is rotatable and wherein the second detent disc for realizing the freewheel a radially viewed in the direction of the central longitudinal axis of the shaft ( 9 ) on which it is mounted, extending projection ( 15 ), which in a ring segment-shaped groove ( 12 ) predetermined size, so that a freewheel in the direction of rotation between the ends of the annular segment-shaped groove ( 12 ) along the outer diameter of the shaft ( 9 ) is realized. Parksperrenaktuator for a parking lock of a motor vehicle automatic transmission, according to claim 1, characterized in that (through the freewheeling of the second notched disk 8th ) during the Auslegevorgangs the parking brake, a pulse is generated, which supports the Auslegevorgang, wherein the operation of the parking brake in the opening direction, the first detent disc ( 7 ) with the wave ( 9 ) relative to the second detent disc ( 8th ) in the sense of charging the leg spring ( 6 ), wherein, when a predetermined charge of the leg spring ( 6 ) is reached, with the connecting rod ( 1 ) operatively connected second detent disc ( 8th ) a by the relative rotational movement of the shaft ( 9 ) to the fixed with the parking brake second detent disc ( 8th ) conditional pulse is transmitted due to the achievement of the corresponding stop of the freewheel, wherein the degree of charging of the leg spring ( 6 ) at the time of impulse transmission by the dimensioning of the annular segment-shaped groove ( 12 ) of the freewheel is determinable. Parksperrenaktuator for a parking brake of a motor vehicle automatic transmission, according to claim 2, characterized in that the momentum transfer takes place before the leg spring force has reached the force necessary to overcome the self-locking force, ie the required Auslegekraft. Parksperrenaktuator for a parking brake of a motor vehicle automatic transmission, according to claim 2, characterized in that the momentum transfer takes place after the leg spring force has reached the required Auslegekraft or when the Auslegefederkraft reaches the required Auslegekraft. A parking brake actuator for a parking lock of a motor vehicle automatic transmission, according to one of the preceding claims, characterized in that a locking unit ( 16 ) is provided, via which the states "parking brake engaged" and "parking brake designed" by the intervention of a Rastierelementes ( 18 ) in locking grooves ( 17 ) are rested. Parksperrenaktuator for a parking brake of a motor vehicle automatic transmission, according to claim 5, characterized in that for emergency unlocking the parking brake with the first detent disc ( 7 ) associated levers ( 20 ) via a screw ( 13 ) is operable, wherein in the piston rod ( 14 ) of the delivery device ( 5 ) a transverse groove ( 19 ) is provided, which is an axial movement of the lever ( 20 ) in the direction of the delivery device ( 5 ) and thus a rotational movement of the shaft ( 9 ) and the one with the wave ( 9 ) rotatably connected first detent disc ( 7 ) in the opening direction of the parking brake even with a locked engaged parking brake and non-functioning delivery device ( 5 ).

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