DE102008036971B3 - Emergency release for parking lock of automatic transmission of motor vehicle, has operating wheel manually operated to bring parking lock element in outer engagement with parking lock wheel even in inactive condition of transmission - Google Patents

Abstract

The release (10) has a connecting element (40) designed as Bowden cable (42) and coupled between a disengagement lever (28) and a disengagement mechanism (49). The mechanism comprises a worm drive (50) that comprises a worm wheel (48) and a worm shaft (52) that is connected with an operating wheel (70). The wheel is manually operated to bring a parking lock element (16) in outer engagement with a parking lock wheel (14) even in inactive condition of a transmission over the lever in case of malfunction of force assisted control rod (22). The mechanism is made of plastic.

Description

The The present invention relates to a mechanical unlocking device for one Parking lock of an automated or automatic transmission of a Motor vehicle. The present invention enables a helpless Unlocking the parking lock of the transmission, the unlocking preferably by means of a slight manual force by the driver, in particular out of a vehicle interior, can be made.

Emergency unlocking for parking barriers are known in the art.

In the German patent DE 43 17 257 C1 a parking brake for automatic transmissions of motor vehicles is disclosed which blocks or releases an automatic transmission due to a triggered by the driver via an operating device actuating signal in the normal state by a pawl in a parking gear on an output shaft of the automatic transmission on or disengages, wherein the Pawl is operated by displacing a connecting rod, which is mounted between the pawl and the movable part of a hydraulic unit, which in turn consists of a piston, a cylinder and a return spring, wherein the parking brake is connected to another operable by the driver control device, with the locked in the parking gear pawl, the connecting rod can be moved so that the pawl releases the parking gear. A disadvantage of this solution is the high, manually expended by the driver force to operate the emergency release. The force to be expended in order to unlock the locked parking lock in an emergency (eg towing the motor vehicle after it has stopped) is all the greater when the vehicle is being parked, for example. B. is on a slope, because then gravity exerts a permanent force on the output shaft. This increases the frictional force to be overcome in the entire actuating mechanism of the parking brake. Another disadvantage is the fact that the disengagement of the pawl is jerky, so that the driver is exposed during the opening of the parking brake the risk of seriously injuring a sudden relaxation.

Other unlocking devices are in the publications DE 199 40 029 A1 . EP 1 111 275 B1 . EP 1 199 234 A2 as well as in the DE 101 15 126 A1 disclosed.

The emergency releases known from the prior art have the Disadvantage that, especially with a manual operation, very high forces have to be spent the only outermost Effort can be spent by the driver. There is also a risk that one already open Parking lock due to reset mechanisms jumps back into its locked state, because the driver is the To hold open the parking brake required holding force is not permanent can.

The DE 10 2006 037 660 A1 further discloses a hydraulic vehicle brake with integrated electric motor-operated parking brake. There, an emergency release by means of worm shaft is revealed by hand.

It is therefore an object of the present invention, a mechanical Emergency release for one Provide parking brake of automatic transmissions for motor vehicles, which are operated with little effort, especially manually can. A sudden relaxation at the moment of opening the Parking lock should be as possible be prevented. Furthermore is it desirable that the opening the parking lock required force can not be spent permanently has to open the parking lock in the To maintain state.

These Task is with a mechanical emergency release for a parking brake solved an automatic motor vehicle transmission, the parking brake on rotatably mounted on an output shaft of the transmission Parksperrrad and a parking pawl or parking pawl, wherein the parking pawl in an inactive state of the transmission due to a by a Spring device applied to the parking pawl force with the Parksperrrad is engaged and remains there, and the parking pawl in an active normal state of the transmission by a power assisted shift rod except Intervention is brought with the Parksperrrad, wherein the mechanical Emergency release includes: a release lever that fits in with one gearbox rotatably mounted and preferably leading out of the gear housing Shaft is rotatably connected; a return mechanism; and a Connecting element between the release lever and the release mechanism is coupled; the release mechanism a worm gear having a worm wheel and a Worm shaft, wherein the worm shaft with the operating wheel connectable, which can be manually operated to in case a failure of the power-assisting Shift rod the parking pawl itself in the inactive state of Transmission over the release lever out of engagement to bring with the park ratchet wheel.

The use of a worm gear to apply the force required for an emergency opening of the parking brake has the advantage that only very small forces must be expended in order to overcome the high blocking forces. by virtue of the freely selectable, high reduction ratio is the worm gear as Leistungsgetrie be used. The force required to drive the worm shaft can be applied manually by the driver.

One Another advantage is the self-locking of the worm gear to see. The self-locking prevents an independent reset the parking lock in its locked state. Braking devices, the usual are used to prevent such a process are Therefore, according to the present Invention not required.

There the release lever and the release or reset mechanism is connected to each other by means of a connecting element is it does not require that the release mechanism in the immediate spatial Proximity to release lever is arranged. The release mechanism can thus be mounted at any location in or on the motor vehicle become. An arrangement of the release mechanism within the motor vehicle is desirable to prevent that the driver when releasing the Parking lock of which may be itself is being rolled over.

One Another advantage of the present invention is to be seen in that the operating wheel is not permanent with the release mechanism must be connected. Since it is in the present invention to an emergency release, it is assumed that the emergency release not too often during the life of the motor vehicle must be actuated. In case of emergancy can the operating wheel be attached to the worm shaft. The operating wheel disturbs the Driver in normal operation so not.

As soon as the error that leads to the failure of the otherwise automatically operated parking brake has led is fixed, locking and unlocking the parking lock again by means of the conventional automated mechanisms are made. The mechanical Emergency release of the present invention is designed so that Do not mess with the conventional one automated actuation mechanism for the parking brake disturbs. Naturally The parking lock can also by means of emergency release by opposite Actuate (Turning) the worm shaft reset, d. H. getting closed.

According to one preferred embodiment the worm wheel only in the form of a segment - and thus not as a full wheel - provided.

This results in a space saving and a reduction of the total weight the release mechanism, so that in particular the release mechanism can be arranged in places that are only a spatially very allow limited expansion.

Further it is advantageous if the release mechanism is a multi-part housing block having, in its interior space for receiving the worm wheel and the worm shaft offers.

By the multi-part of the housing block is guaranteed that in case of wear of the Worm wheel and / or the worm shaft the worn element can be exchanged quickly and easily. The worm wheel and the worm shaft are disposed within the housing block to a damage prevent these elements from external influences.

Also It is advantageous if the connecting element with the worm wheel is rotatably connected, wherein the housing block has a first opening for execution the actuating wheel, a non-positive Connection between the operating wheel and the worm shaft, and a second opening to execution comprising the connecting element through the housing block.

These Type of arrangement allows an extremely compact Construction. The operating wheel can while Times when the transmission is working normally at another Place and only in case of emergency on the release mechanism or in the housing block be plugged in.

According to one Another preferred embodiment, the worm wheel means Bushings or a bolt, the center of the housing block sticking out and outside of the housing block connected to a rotary arm for coupling to the connecting element is rotatable in the housing block stored.

The Providing bushings or a bolt increases stability and ensures at the same time that the worm wheel within the housing block while an actuation, at the very high forces applied to the worm wheel its position relative to the housing block is not changed. So can be guaranteed be that required for adjusting the individual components Verstellwege safely covered become.

According to one another preferred embodiment is the worm shaft in its axial direction with a disk in the housing block secured.

The disc prevents the worm shaft from being moved out of the housing block by restoring forces (eg spring), in particular when the parking lock has been opened in an emergency. The Disc serves as an abutment to ensure the effect of self-locking.

Farther It is advantageous if the connecting element is a cable or Bowden cable is.

at Use of a cable or Bowden cable can be the release mechanism positioned at any location in or on the motor vehicle become. Should it be necessary, pulleys may be provided be to the train from the release mechanism to the release lever to steer.

According to one Another preferred embodiment of the release mechanism, in particular the housing block, the worm wheel and the worm shaft, made of plastic.

The Use of plastic results in a lower weight and reduces the manufacturing costs. It is assumed, that an emergency release is not carried out too often in the "life" of a motor vehicle, so the higher one Wear at Plastic (compared to for example metal) negligible is.

Also let yourself the release mechanism, the The worm gear comprises, by injection molding extremely compact and cheap make, so that the release mechanism also very little Space needed for installation.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

embodiments The invention are illustrated in the drawings and in the following description explained. Show it:

1 a perspective view of a mechanical emergency release according to the present invention;

2 an isolated view of the release mechanism of 1 with closed housing;

3 a section through the release mechanism of 2 ;

4 another embodiment of a release mechanism according to the present invention; and

5 a section through the release mechanism of 4 ,

In the following description of the figures, a mechanical emergency release for a parking brake according to the present invention is generally with 10 be designated. Like features will be denoted by like reference numerals. Similar features will be denoted by similar reference numerals.

1 shows a schematic perspective view of a mechanical emergency release 10 for a parking lock 12 according to the present invention. The parking lock 12 is used in particular in automatic and automated transmissions of motor vehicles.

The parking lock 12 has a park ratchet wheel 14 and a parking pawl or parking pawl 16 on. The park ratchet wheel 14 is rotatably mounted on a transmission output shaft, not shown here. The Parksperrrad is provided along its outer circumference with a plurality of alternating teeth and gaps. The parking pawl 16 has a projection for engaging in one of the gaps of the Parkperrrads 14 is adjusted.

In the 1 engages the projection of the parking pawl 16 in one of the gaps of the park wheel 14 one. When the parking pawl 16 so engaged with the Parksperrrad 14 is, is the parking lock 12 active, ie locked. The parking pawl 16 is mounted on a transmission housing not shown here in detail, that a rotation of the Parksperrrads 14 in the 1 shown state is not possible. This means that, even if the motor vehicle z. B. is parked on a slope, the transmitted via the wheels of the motor vehicle to the output shaft driving force rotation of the transmission output shaft - and thus the Parksperrrads 14 - unable to effect. In the 1 So a situation is shown as it exists when the motor vehicle is inactive and the parking brake 12 is active.

A spring device 18 works over an arm 19 on the parking pawl 16 so to the parking pawl 16 out of engagement with the wheel 14 bring to. To the parking lock 12 To open, the parking pawl must 16 out of engagement with the Parksperrrad 14 be brought, as exemplified by an arrow 20 is indicated. In the 1 can the park pawl 16 for unlocking by means of the arm 19 be lifted when the arm of a push rod 22 is free. The arm 19 is in the 1 with the help of a shift rod 22 locked. The release of the arm 19 takes place by an axial movement of the shift rod 22 in the direction L, which is preferably oriented parallel to the axis of the transmission output shaft. The pole 22 is then with an auxiliary power axially from the pawl 16 Moves away, as indicated by a double arrow 26 is indicated, where "L" stands for release and "V" for locking.

When the motor vehicle is in operation (ie activated), the shift rod is 22 in position L (L = release). This is the shift rod 22 with the assistant in the direction L moves. The feather 18 then causes that arm 19 is still moved up. The parking pawl 16 is thus disengaged from the Parksperrrad 14 brought as it is by the arrow 20 or a dark arrow is indicated without further description. As soon as the motor vehicle is deactivated, the auxiliary power is taken away. A feather 100 Fixed at one end and at the other end at the pole 22 is stored, relaxes and moves the rod 22 therefore in the V position. The pole 22 interacts with the latch 16 such that they are in the in the 1 shown position is moved back and so the latch 16 locks. This excludes that the parking brake 12 remains open in an inactive state.

To the parking lock 12 but also in an emergency, ie when no external power to operate the shift rod 22 to be able to open, the present invention provides the following elements described below.

The emergency release 10 also has a release lever 28 on, the rotation with a shaft 30 is connected, which in turn is rotatably mounted in the transmission housing. The wave 30 is about an axis 32 rotatable, as with the help of a double arrow 34 is indicated. The wave 30 can protrude from the transmission housing, not shown here.

The release lever 28 is preferably in the vicinity of the parking pawl 16 arranged. At his the park pawl 16 directly opposite end can be the release lever 28 having a fork-shaped end portion which the shift rod 22 freely surrounds. The fork-shaped end portion is such that an axial movement of the shift rod 22 (in normal operation and also in an emergency) is not affected.

At one end of the wave 30 , which preferably protrudes from the gear housing, here is a bow-shaped unlocking lever or arm 36 provided at his the shaft 30 opposite end z. B. a ball stud 38 having. The wave 30 and the release lever 36 preferably enclose an angle of about 90 °.

To the release lever 36 couples over the ball stud 38 a connecting element 40 at. At the connecting element 40 can it be z. B. a cable or a Bowden cable 42 act. For this purpose, the connecting element 40 at its ends also eyelets 44 exhibit to the element 38 to pair.

At his the release lever 36 opposite end has the connecting element 40 also an eyelet 44 put on a bolt 46 rotatably coupled. The bolt 46 Again, with a worm wheel or worm wheel segment 48 connected, which part of a disengagement or return mechanism 49 according to the present invention.

The release mechanism 49 has a worm gear 50 on. The worm gear 50 has the worm wheel 48 and a worm shaft intermeshing therewith 52 on. The worm shaft 52 is about an axis 54 rotatable in a, preferably multi-part constructed, housing block 56 stored. The housing block 56 is in the 1 shown in a cutaway view. The housing block 56 here only comprises a first housing part 58 , The housing part 58 has one or more openings 60 for receiving z. B. cylinder screws 62 (see also 2 ) on.

The worm shaft 52 has a threaded portion 64 on. The threaded section 64 meshes with a correspondingly toothed section of the worm wheel 48 , which is segmented here. The worm wheel segment 48 is about an axis 66 rotatable in the housing block 56 stored.

The worm shaft 52 is again by means of a disc 68 in the housing block 56 secured. The worm shaft 52 is rotatable in the housing block 56 stored, which by turning a control wheel 70 , such as B. a star wheel, when rotated in the direction of an arrow 72 easily possible. The operating wheel 70 can be operated manually and power assisted. Preferably, the operating wheel 70 but operated manually (by the driver of the motor vehicle). The operating wheel 70 can be connected to the worm shaft 52 be formed, so that the operating wheel 70 not necessarily permanent with the shaft 52 connected is. This can be beneficial if the release mechanism 49 is arranged at a point in the motor vehicle, where the wheel 70 can be inserted from the interior of the vehicle forth in a corresponding opening to the shaft 52 to be connected. In normal operation, the operating wheel 70 stored in another location, so that it does not protrude into the interior of the motor vehicle. It is understood that the release mechanism 49 can be arranged at any location in or on the motor vehicle. The release mechanism 49 is built as compact as possible, including the housing block 56 is preferably injected from plastic. An interior of the housing block 56 is dimensioned so that the worm wheel 48 or the corresponding segment, as in 1 shown, just enough far enough to be turned to the one for disengaging the pawl 16 required swing to initiate movement.

The following is the disengagement of the latch 16 - And thus the release (L) of the parking brake 12 - be described in an emergency. An emergency is z. B. then before, if no auxiliary power is available from the motor vehicle to the shift rod 22 (in the L direction).

In this case, the operating wheel 70 if it is kept separately, on the shaft 52 plugged and turned in the L-direction, as indicated by the arrow 72 is indicated. The rotation of the shaft 52 causes the worm wheel segment 48 along the arrow clockwise (direction L) around the axis 66 rotates. This rotation, in turn, causes the bolt as well 46 that rotates in the worm wheel segment 48 is mounted, rotates clockwise and thus a movement of the cable 42 in the 1 to the right (direction L) causes.

This in turn causes a rotation of the Entriegelungsarms 36 clockwise when looking at the axis from above 32 the wave 30 looks. The wave 30 thus also rotates clockwise. Because the wave 30 rotatably with the release lever 28 connected, the lever moves 28 against the spring 100 ,

Because the spring 100 stuck with the pole 22 is connected, it exerts an axial force in the L direction on the rod 22 out. The feather 100 is pressed against the housing wall and stretched. The force to be applied can be relatively large. The feather 100 is at its end, the lever 28 facing, positively with the rod 22 connected and therefore pushes the rod 22 usually strong in the V position. However, there is a worm gear 50 is used with preferably large reduction, the driver has to spend only a small force to a laborious pivoting of the arm 28 to effect in the L direction. Due to the self-locking of the worm gear 50 will prevent the spring device 100 the release lever 28 pushes back into the V position and thus the parking brake 12 locked again ..

In this way it is possible, although no auxiliary power is available, the parking brake 12 to manually unlock in an emergency. The unlocking takes place permanently.

However, the unlocking can in turn be canceled by the operating wheel 70 is rotated counterclockwise.

In the 2 is the release mechanism 49 of the 1 shown in an isolated perspective view.

In the 2 is the housing block 56 closed. The housing block 56 has the first housing part 58 and a second housing part 76 on. The housing block 56 is with suitable fasteners, such. B. cylinder screws 62 , kept closed and has at least two openings. A first opening 78 serves to pass the in the 2 not shown cable 42 through the housing block 56 , A second opening, which is not designated here, serves to carry out the axis of the actuating wheel 70 through the housing block 56 ,

In the 3 is a sectional view through the release mechanism 49 of the 2 shown.

The worm wheel 48 or the worm wheel segment 48 is preferably formed in one piece and directly in the housing block 56 stored. If desired, however, in the area of the axis of rotation 66 one or more sockets 80 between the worm wheel 48 and the housing block 56 be provided.

In 4 is a modification of the release mechanism in the form of a release mechanism 49 ' shown.

The release mechanism 49 ' is different from the release mechanism 49 of the 1 to 3 in that a full worm wheel 48 ' instead of a segment 48 is provided. As seen from the sectional view of 5 can be seen, is the Schneckenvollrad 48 ' also around the axis of rotation 66 rotatably mounted.

The coupling to the connecting element 40 or to the cable 42 but is done via a rotary arm 82 which is rotatable in both directions, as indicated by an arrow 84 is indicated. The rotary arm 82 is by means of a bolt 88 rotatably with the worm wheel 48 ' connected. The rotary arm 82 is in the embodiment of the release mechanism 49 ' of the 4 and 5 laterally outside of the housing block 56 arranged. This may be for special spatial arrangements of the release mechanism 59 be advantageous relative to the motor vehicle, depending on the installation location.

In addition, a cable puller 86 on the housing block 56 be provided to ensure that the connecting element 40 always guided along a predetermined path and is fixed so. At the cable puller 86 puts a cable counterpart 101 (eg Bowden head).

The present invention is distinguished, inter alia, by the fact that no great effort is required dig is to release the parking brake. A danger to the driver, z. B. hillside position of the vehicle by rolling over during the actuation process can by arrangement of the emergency release 10 be excluded within the vehicle. A mechanism for keeping open the parking brake is also not required because the worm gear acts self-locking.

By the multiple levers that can be used in optional lengths can the effort required to open the parking brake be adapted to the vehicle conditions.

By Using a cable connection can close the emergency release be arranged at any location in the vehicle.

There the emergency release mechanism usually only a few times during a "life" of the motor vehicle actuated will, can some or all components of the emergency release mechanism, in particular the release mechanism, be made of plastic. This reduces on the one hand that Weight. On the other hand it facilitates the production (injection molding process). The production costs are reduced thereby.

Claims (8)

Emergency release ( 10 ) for a parking brake ( 12 ) of an automatic motor vehicle transmission, wherein the parking lock ( 12 ) a non-rotatably mounted on an output shaft of the transmission Parksperrrad ( 14 ) and a parking pawl ( 16 ), wherein the parking pawl ( 16 ) in an inactive state of the transmission due to a spring means ( 100 ) on the park pawl ( 16 ) applied force in engagement with the Parksperrrad ( 14 ) and remains there, and wherein the parking pawl ( 16 ) in an active normal state of the transmission by a force-assisted shift rod ( 22 ) out of engagement with the Parksperrrad ( 14 ), comprising: - a release lever ( 28 ), which with a rotatably mounted in a transmission housing and preferably leading out of the transmission housing shaft ( 30 ) is rotatably connected; A release mechanism ( 49 ); and a connecting element ( 40 ) between the release lever ( 28 ) and the release mechanism ( 49 ) is coupled; the release mechanism ( 49 ) a worm gear ( 50 ), which is a worm wheel ( 48 ) and a worm shaft ( 52 ), wherein the worm shaft ( 52 ) with an operating wheel ( 70 ), which can be manually operated, in the event of a failure of the power assisted shift rod ( 22 ) the parking pawl ( 16 ) even in the inactive state of the transmission via the release lever ( 28 ) out of engagement with the Parksperrrad ( 14 ) bring to. Emergency release according to claim 1, wherein the worm wheel ( 48 ) is provided only in the form of a segment, and thus not as a full wheel. Emergency release according to claim 1 or 2, wherein the release mechanism ( 49 ) a multi-part housing block ( 56 ), which in its interior space for receiving the worm wheel ( 48 ) and the worm shaft ( 52 ) offers. Emergency release according to one of the preceding claims, wherein the connecting element ( 40 ) with the worm wheel ( 48 ) is rotatably connected, and wherein the housing block ( 56 ) a first opening for carrying out the actuating wheel ( 70 ), a frictional connection between the operating wheel ( 70 ) and the worm shaft ( 52 ) and a second opening ( 78 ) for the passage of the connecting element ( 40 ) through the housing block ( 56 ) having. Emergency release according to claim 4, wherein the worm wheel ( 48 ) by means of sockets ( 80 ) or a bolt ( 88 ), the center of the housing block ( 56 ) and outside the housing block ( 56 ) with a rotary arm ( 82 ) for coupling to the connecting element ( 40 ) is rotatable in the housing block ( 56 ) is stored. Emergency release according to one of claims 3 to 5, wherein the worm shaft ( 52 ) in its axial direction ( 54 ) with a disc ( 68 ) in the housing block ( 56 ) is secured. Emergency release according to one of the preceding claims, wherein the connecting element ( 40 ) a cable or Bowden cable ( 42 ). Emergency release according to one of the preceding claims, wherein the release mechanism ( 49 ), in particular the housing block ( 56 ), the worm wheel ( 48 ) and the worm shaft ( 52 ), is made of plastic or are.