WO2004000599A2

WO2004000599A2 - Manual transmission, in particular manual transmission for a motor vehicle

Info

Publication number: WO2004000599A2
Application number: PCT/DE2003/002083
Authority: WO
Inventors: Carmen Stumm; Burkhard Pollak; James Antony Lethbridge; Christoph Lindenschmidt; Andreas Lauckner; Carsten Bünder; Ian Richard Joseph Bates
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2002-06-24
Filing date: 2003-06-23
Publication date: 2003-12-31
Also published as: AU2003247241A1; ITMI20031266A0; ITMI20031266A1; DE10393324D2; WO2004000599A3; DE10328019B4; FR2841317A1; DE10328019A1

Abstract

The invention relates to a drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock, a clutch that links both elements, in addition to a drive shaft. The selector device for selecting the gears enables a parking lock (3) to be engaged by means of a shift finger (16) and a parking lock gearshift rail (15).

Description

Manual transmission, in particular manual transmission for a motor vehicle

The present invention relates to a drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a clutch connecting it and a drive shaft.

In addition to drive trains with manual transmissions and automatic transmissions, it has also become known to use automated manual transmissions in drive trains of motor vehicles. In the case of the automated manual transmission, an actuator in the form of, for example, an electric motor or two electric motors is used for the selection process and the gear change process in order to be able to carry out the gear changes in a program-controlled manner or to be requested by the driver.

Such an automated manual transmission with the actuators, the clutch for disconnecting the drive train and the operating devices for operating the transmission is designed as a “by-wire” system, in which the actuator (s) are controlled via electronic control pulses and a mechanical one Power transmission path between the selector lever arranged in the vehicle and the transmission is no longer provided. In such an automatically operated transmission in the form of, for example, an automated manual transmission or a double clutch transmission with two clutches and electromotive actuators, it is known to provide a parking lock so that this The park lock can be used to block the output shaft of the transmission and thus the drive train. According to the state of the art, the park lock is actuated by its own additional actuator.

The present invention is based on the object of specifying a drive train which requires a smaller number of actuators than in the prior art and to couple the parking lock contained therein to the parking brake so that it can be actuated manually in an emergency. This problem is solved by a drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a clutch connecting it and a drive shaft, in which the manual transmission has a selector device for gear selection with an arrangement. tion of at least a first shift rail and a parking lock shift rail for actuating the parking lock and a shift finger, which is to be brought into engagement with the first shift rail and the parking lock shift rail. The parking lock shift rail is integrated as an additional shift rail in the selection device for gear selection with an arrangement with at least one first shift rail. The parking lock shift rail can be actuated by the same shift finger with which the shift rails can be operated for gear selection. The transmission of the drive train according to the invention therefore does not require an additional actuator to actuate the parking lock.

Preferably, several shift rails are present in the gearbox of the drive train according to the invention. Two gears can be engaged with each of the shift rails so that the number of shift rails corresponds to the number of gears.

The shift finger can preferably be moved by a gear actuator. The gear actuator enables a translational movement of the shift finger in the axial direction of the shift shaft on which the shift finger is arranged, and a rotational movement of the shift finger about the longitudinal axis of the shift shaft. The gear actuator is preferably operated electrically.

In a preferred embodiment of the drive train according to the invention it is provided that the displacement path of the parking lock shift rail is greater than the displacement path of the shift rails. In a further preferred embodiment it is provided that the shift mouth of the parking lock shift rail is arranged displaced with respect to the shift mouths of the shift rail. These measures make it possible that the displacement path for engaging the parking lock is twice as large as the displacement path for engaging a gear. This double displacement path can be used by a suitable reduction to be able to exert a correspondingly high force without having to make a change to the actuators. A shift of the shift finger into the aisle of the parking lock shift rail is preferably possible in any position of the shift rails. This means that the parking lock can be operated regardless of the gear engaged. For example, an even and an odd gear or only one of the gears can be engaged, wherein the parking lock can also be engaged as desired.

Alternatively, it can be provided that a shifting of the shift finger into the aisle of the parking lock shift rail is only possible in certain positions of the adjacent shift rails. For example, this can mean that the alley of the parking lock shift rail can only be reached when the first gear is engaged or, for example, only when the reverse gear is engaged. In particular in the case of a transmission with only one clutch, it can thus be ensured that the parking lock can only be engaged in a specific operating state.

The problem mentioned at the outset is also solved by a drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a coupling connecting this and a drive shaft in which the parking lock can be opened by a hydraulic parking lock slave cylinder, the parking lock slave cylinder can be actuated by a master cylinder of a hydraulic clutch system. The master cylinder of the hydraulic clutch system is preferably actuated by an electrically operated actuator. The manual transmission is preferably a so-called automatic manual transmission, in which both the gear selection and the clutch actuation are carried out by electronically controlled and electrically operated actuators. In the manual transmission of the drive train according to the invention, no separate master cylinder is now necessary to actuate the parking lock. This function is also taken over by the master cylinder for clutch actuation.

A first valve is preferably arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system. This valve makes it possible to decouple or connect the parking lock slave cylinder from the hydraulic system as desired and thus to enable or prevent actuation. A switchover valve is preferably arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system, which enables hydraulic fluid to flow into the parking lock slave cylinder in a first switching position and hydraulic fluid to flow out of the parking lock slave cylinder in a second switching position. In addition, a check valve is preferably arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system, which prevents hydraulic fluid from flowing back out of the parking lock slave cylinder in the first switching position of the reversing valve. This measure prevents the parking lock from being inserted in the event of a pressure drop in the hydraulic system, for example in the event of a malfunction or a leak in the hydraulic system.

In a first variant of the manual transmission of the drive train according to the invention, the hydraulic pressure required to actuate the parking lock slave cylinder is lower than the hydraulic pressure required to actuate the clutch slave cylinder. When the master cylinder is actuated, the parking lock is opened first, then the clutch is opened. The previously mentioned check valve in connection with a suitable valve position of the changeover valve prevents backflow of the hydraulic fluid and thus the closing of the parking lock. Special measures for uncoupling the slave cylinder of the clutch are not necessary in this case, since the parking lock can first be actuated by the higher pressure required to actuate the clutch slave cylinder compared to the pressure required to actuate the parking lock slave cylinder.

Alternatively, the gearbox can include a second valve with which the clutch slave cylinder can be decoupled from the hydraulic line. In this case, the operating pressure required to actuate the parking lock slave cylinder can also be higher than the operating pressure required to actuate the clutch.

The problem mentioned at the outset is also solved by a hydraulic system, in particular for motor vehicles, comprising a master cylinder, a slave cylinder for actuating a motor-transmission clutch and a pressure medium line connecting it. device solved, in which the master cylinder is connected via a further hydraulic line to a parking lock slave cylinder for actuating a parking lock.

The problem mentioned at the outset is also solved by a drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a coupling connecting this and a drive shaft, in which the parking lock can be opened by an actuator and additionally with a manual one operated lever can be opened. An advantageous embodiment of the invention provides that the emergency actuation of the parking lock in the passenger compartment is covered by the lever of the parking brake during driving, in order to ensure that the vehicle is inevitably parked safely by means of its parking brake before the parking lock is released.

In a further advantageous embodiment of the invention, it is provided that the parking lock is permanently connected to the foot or hand-operated parking brake in an emergency by means of at least one adapter or connecting element. This connecting element can be, for example, a split pin or a screw. If the actuator system for opening the parking lock fails, for example if the entire electrical system of the vehicle fails or if there is a fault in the actuator for actuating the parking lock, the parking lock can be opened in this way and the vehicle can be made able to roll, for example for towing.

For this purpose, the lever is preferably connected to the parking lock via an transmission element with an actuating element. The transmission means can be, for example, a Bowden cable or the like. Alternatively, other pull or push actuation means are also possible here.

The transmission means is preferably arranged eccentrically on the lever. In this way, a translation is realized when the lever is actuated, so it is a comparatively long way with a comparatively small force to actuate the transmission means.

The transmission means is preferably arranged eccentrically on the lever by means of a bolt. In this way, the lever can be turned about 180 °. In a development of the drive train according to the invention, the lever covers a screw for manually actuating a clutch actuator in a driving operating position. The lever takes on a second function in this way, it prevents the possibility of actuating the screw for manual actuation of the clutch actuator during normal operation.

The screw is preferably arranged in a recess which is covered by a cap made of preferably elastic material. The depression is preferably dustproof and / or waterproof covered by the cap. This measure prevents damage or contamination of the screw for manual actuation of the clutch actuator.

The invention further relates to a method for controlling a drive train of a motor vehicle, the drive train comprising a drive motor, a transmission, a coupling connecting it, a drive shaft and a shaft brake connected to the drive shaft in a rotationally fixed manner.

The shaft brake of the drive train is usually used as a parking brake or as a supporting service brake. According to the invention, it is now provided that the shaft brake applies an additional holding torque in certain operating states. In this way, the range of applications for the shaft brake can be expanded.

In particular, it can be provided that an additional holding torque is applied by the shaft brake to start the motor vehicle on an incline. It is preferably provided that the sum of the holding torque applied by the shaft brake and the clutch torque of the clutch corresponds to the torque required to hold the motor vehicle on an incline. This reduces the thermal load and wear on the clutch.

The shaft brake is preferably opened completely as soon as the torque applied by the clutch is greater than that required to hold the motor vehicle Moment. In this operating state, the torque applied by the clutch is sufficient to start the vehicle. With a closed shaft brake, this would therefore counteract the starting torque.

In a further development of the invention, it is provided that an additional holding torque is applied on a slope by the shaft brake in order to shift the transmission. This prevents undesired acceleration of the vehicle, particularly in overrun mode.

In a further development of the invention it is provided that the additional holding torque is applied until after the engagement of a new gear the engine speed of the drive motor is synchronized and the clutch can be closed almost without torque. This measure enables the gearbox to be shifted without causing thermal stress or wear on the clutch.

The invention is explained below with reference to the accompanying drawings.

Show:

Figure 1 is a schematic representation of a parking lock in the locked state.

Figure 2 is a schematic representation of a parking lock in the unlocked state.

3 shows an arrangement of shift rails, a shift finger and design geometries; 4 shows a first example of a switching state;

5 shows a second example of a switching state;

6a - d sketches on the functioning of the arrangement according to FIG. 3;

Fig. 7-9 further embodiments as circuit diagrams for parking lock actuation;

10 shows a first embodiment of a hydraulically operated parking lock; 11 shows a second embodiment of a hydraulically operated parking lock;

12 shows a first embodiment of a lever for actuating an emergency release device; 13 shows a second embodiment of a lever for actuating an emergency release device in a first position;

14 shows the second embodiment of a lever for actuating an emergency release device in a second position; Fig. 15 shows a solution to the emergency operation under the lever of the parking brake

16 shows a further solution for an emergency actuation for a parking lock

17 shows a drive train of a motor vehicle with a shaft brake;

18 shows a schematic diagram of a drive train of a motor vehicle.

18 shows a schematic diagram of a drive train 80 of a motor vehicle 70. A four-wheel vehicle 70 is shown, in which a drive motor 71 drives an axle 76 with wheels 77 arranged therein via a clutch 72 and a transmission 73 and a drive shaft 74 via a differential 75 , The drive train shown is basically identical in a vehicle with front-wheel drive and rear-wheel drive, only the arrangement of the transmission and downstream drive means change. The principle shown can also be applied to a vehicle with all-wheel drive.

A parking lock wheel 1 according to FIG. 1 is arranged on a transmission output shaft 2 in a rotationally fixed manner. The transmission output shaft is connected to drive wheels, not shown here, of a motor vehicle via a differential gear and associated drive shafts. A parking pawl 3 is connected to the transmission housing 4, which is only shown schematically, by means of a schematically illustrated rotatable suspension 5. The parking pawl 3 can be rotated about the suspension 5 and, in a first position as the parking position according to FIG. 1, engages with the parking lock wheel 1 and thus fixes the parking lock wheel 1 and the transmission output shaft 2 with respect to the transmission housing 4. 2, the parking pawl 3 is not in engagement with the parking pawl wheel 1 and thus enables the transmission output shaft 2 to rotate freely. The parking pawl 3 is pulled into the locking position according to FIG. 1 by a spring 6. Against the force of the spring 6, an actuating element 7 can push the parking pawl 3 into the unlocked position according to FIG. 2. The actuating element 7 can be carried out, for example, by a shift finger, not shown here, which is actuated by actuators moved by an electric motor. through of a holding element 8, which can be an electric actuator, for example, the parking pawl 3 is held in the driving operating position according to FIG. 2. The holding element 8 can be, for example, an electromagnet, which can hold the parking pawl 3 in the driving operating position according to FIG. 2 with a low holding current.

Fig. 3 shows a selector 10 for gear selection in a manual transmission. The basic arrangement of four shift rails, namely a first shift rail 11, a second shift rail 12, a third shift rail 13 and a fourth shift rail 14, is shown. In addition, a parking lock shift rail 15 is provided. The respective shift rails 11, 12, 13, 14 are to be displaced by a displacement path 27 for engaging a gear. As can be seen directly from the sketches in FIGS. 3 to 5, the displacement path 28 for inserting the parking lock is significantly larger, here approximately twice as large as the displacement path for gear actuation 27.

The first to fourth shift rails are each connected to shift forks that serve to shift the individual gears. In the present case, the transmission has 7 forward gears and one reverse gear, the assignment is shown with numbers 1 to 7 and the letter R. The parking lock switch rail 15 is connected to the actuating element 7 shown in FIGS. 1 and 2. The shift rails can be moved by a shift finger 16, which is arranged on a shift shaft 17. For this purpose, the shift finger can engage in a shift mouthpiece 19 in the shift rails 11, 12, 13, 14, 15. Furthermore, at least two design geometries 18 are arranged on the control shaft 17. The design geometries 18 can each interact with the shift rails 11 to 15, in which there is currently no engagement with the shift finger 16. The selector shaft 17 is rotatable about its longitudinal axis and, in the illustration in FIG. 1, can be displaced in the vertical direction in the plane of the drawing, so that the selector finger 16 can be brought into engagement with each selector rail 11 to 15. The shift rails 11 to 15 are usually also referred to as alleys. A movement of the shift rails takes place by rotating the shift shaft 17 about its axis, so that the link-like guides of the shift rails 11 to 15 can be moved from left to right or vice versa by means of the shift finger 16 in the plane of FIG. 3. The parking lock shift rail 15 connected to the parking lock is shifted by half the actuation path relative to the other shift rails, as FIG. 3 immediately illustrates. 3, the transmission is in the neutral position, the parking lock is in the open position. The wide shift mouth of the shift rail of the parking lock is shifted compared to the other shift rails.

Fig. 4 shows a switching state in which the gears 4 and 5 are engaged, the parking lock is still open. In FIG. 5, in addition to the illustration in FIG. 4, the parking lock is also inserted. It can be seen in FIGS. 3 to 5 that the path of the parking lock shift rail 15 is twice as long as, for example, that of the second and fourth shift rails 12 and 14 belonging to the gears 4 and 5. Due to the offset arrangement of the shift jaws in FIG. 3 the selection, switching on or off of all gears and the parking lock are still possible. Due to the larger actuation path of the parking lock shift rail 15 compared to the shift rails for engaging the gears, a greater amount of work can be done by the parking lock shift rail 15 for actuating the parking lock at a predetermined torque for rotating the shift shaft 17. In particular, the geometry of the shift finger 16 and the parking lock shift rail 15 or that part of the parking lock shift rail 15 which engages with the shift finger 16 can be designed such that the greatest possible force can be exerted. In this way, a much greater force for actuating the parking lock can be applied with a relatively low-power actuator for actuating the manual transmission.

6a, 6b, 6c and 6d illustrate the functioning of the circuit shown in FIGS. 3 to 5. Shown is the shift finger 16 which is brought into engagement with the fifth shift rail 15 or the third shift rail 13.

6a, the shift finger 16 is in the middle position and can thus be moved and positioned to any shift rail. By moving the shift finger 16 in the illustration in FIG. 6b, the parking lock is engaged. The design geometries 18 are in this position of the shift finger 16, that is to say if it can be brought into engagement with the parking lock shift rail 15, outside of the first to the second to the first fourth shift rail 11 to 14, so that engaged gears are not shifted out again. In other words, the fifth shift rail 15 is the only shift rail that can be actuated without this having an influence on the switching state of the first to fourth shift rails. The design geometries 18 are otherwise arranged such that the fifth or seventh gear is automatically switched off when the first gear is shifted, for example, or the second or fourth gear is automatically switched off when the sixth gear is shifted.

6c shows the shift finger 16 rotated back into the middle position. Other lanes can be controlled here, as in the illustration in FIG. 6a. The parking lock can be removed by turning the shift finger 16 as shown in FIG. 6d.

Due to the increased path of parking lock actuation, the actuator can be dimensioned smaller, a balanced layout between the actuation forces for synchronizing and designing the parking position is possible. This is also necessary with regard to the path resolution and dynamics of the actuators, since the use of a stronger motor would also increase the time constant.

3 to 6 are usually used in transmissions with a double clutch and two gear trains, in which all odd gears are served by one gear train with one clutch and all even gears are served by one gear train with another clutch. With such gearshifts it is permissible that an even and an odd gear are engaged at the same time, since these are ultimately operated by different clutches. Such transmissions also enable the transmission of a torque during the shifting process by preselecting the next higher gear, so that a similarly smooth acceleration can be achieved with a manual transmission as with an automatic transmission.

7 illustrates a further embodiment of the parking lock actuation according to the invention. In this case, a gearbox with an input shaft that rotations can be applied to a single clutch. With such a transmission, only one gear can and may be engaged at a time. For this purpose, the shift gate is equipped with a first shift rail 21, a second shift rail 22 and a third shift rail 23, in which the shift finger (not shown here) can be moved into the other aisle in the middle position of the shift rails. This ensures that two gears can never be engaged at the same time. A change to the alley of the parking lock is only possible from the first gear in the illustration in FIG. 7. For the movement of the parking lock shift rail 15, there is thus a double way of actuation compared to engaging a gear.

FIG. 8 illustrates an arrangement according to FIG. 7, in which the parking lock can only be engaged from the reverse gear, which is designated REV.

Fig. 9 illustrates a further alternative embodiment, in which a gap is inserted between the parking lock shift rail 25 and the other shift rails 21 to 23, so that a sweeping movement of the shift finger and thus an additional selection movement is required along the dashed line 26.

10 shows a sketch of a hydraulically operated parking lock. A master cylinder 31 is shown, which can act via a hydraulic line 32 on a clutch slave cylinder of a clutch, not shown here, between an engine and a transmission of a motor vehicle. The master cylinder 31 is actuated by an electrical actuator, not shown here, for example. A second hydraulic line 35 is connected to the hydraulic line 32 at a branch 34. The second hydraulic line 35 is connected to a parking lock slave cylinder 36. A check valve 37 and a changeover valve 38 are also arranged in the second hydraulic line 35. The changeover valve 38 makes it possible to couple a hydraulic line of the parking lock slave cylinder 36 either to the hydraulic line 30 via the second hydraulic line 35 or a third hydraulic line 40. 10, the changeover valve 38 is in a position in which the second hydraulic line 35 connects to the hydraulic line 39 of the parking lock merzylinders 36 is connected. The check valve 37 allows a flow only in the direction of the parking lock slave cylinder, this is indicated by an arrow 41. A dashed arrow 42 in FIG. 10 indicates the second position of the changeover valve 38. In this switching state of the changeover valve 38, hydraulic fluid can flow in both directions, but in particular from the parking lock slave cylinder 36 in the direction of the master cylinder 31. In the first switching position of the changeover valve 38 indicated by the arrow 41 in FIG. 10, only a flow of the hydraulic fluid can take place in the direction of the parking lock slave cylinder 36, so that when the master cylinder 31 is actuated, the only schematically arranged parking lock 43 is opened. This occurs against the force of a return spring 44. In the second position of the changeover valve 32 indicated by the dashed arrow 42 in FIG. 10, hydraulic fluid can flow in the opposite direction, ie the parking lock slave cylinder 36 is emptied, for example, by the force of the return spring 44, so that the Parking lock 43 is closed.

In the embodiment according to the description of FIG. 10, it is assumed that the actuating pressure for actuating the parking lock is lower than the pressure for actuating the clutch and slave cylinder 33. If this is not the case, an alternative embodiment can be shown 11 are used. Here, a second valve 45 is arranged in the hydraulic line 32 in front of the clutch slave cylinder 33, which enables the hydraulic fluid to the clutch slave cylinder 33 to be switched on and off. The closed second valve 45 is shown in FIG. 11. In the illustration in FIG. 11, the changeover valve 38 allows flow through in the direction of the parking lock slave cylinder 36. With this combination of the positions of the valves, the parking lock can be activated with the master cylinder 31 via the parking lock slave cylinder 36 43 can be opened. When the second valve 45 closes, the check valve 37 prevents the hydraulic fluid from flowing out of the parking lock slave cylinder 36. In the valve position of the changeover valve 38 shown in FIG. 11 with the arrow 41 and the second valve 45 closed, the clutch slave cylinder 33 can be actuated via the master cylinder become. If the changeover valve 38 is brought into the position indicated by the dashed arrow 42 in FIG. 11, hydraulic fluid can flow back from the parking lock slave cylinder 36 due to the force of the return spring 44 and thus actuates the parking lock 43.

12 shows an eccentric lever for actuating the emergency release device of a parking lock. A lever 50 is connected via a pin 51 to a guided bolt 52, which in turn is connected to a Bowden cable 53. The bolt is mounted eccentrically in the lever, so that when the lever 1, which is supported on a base plate 54, is actuated, the Bowden cable 53 is pulled. The lever 50 has flat surfaces 55 on both sides, which are connected to one another by an arc 56. The flat surfaces 55 of the lever 1 ensure that the respective end position of the lever 50 is maintained by a force exerted on the Bowden cable 53, since the radial distance between the pin 51 and the point of contact between the base plate 54 and the lever 50 increases when the lever is moved from its end position and therefore a greater actuation force is required. 1 shows the rest position 57, in which the Bowden cable 53, as can be seen immediately, is not tightened; An actuation position 58, in which the Bowden cable 53 is tightened, is shown as a dashed line. When the lever 50 is actuated, it is not necessary to overcome the force acting on the Bowden cable, but only a lower force which is reduced by the cam mechanism formed from the flat surfaces 55 and the circular arc 56. The Bowden cable 53 is connected, for example, to an actuating element 7 according to FIG. 2 and can move it into the driving operating position according to FIG. 2. Instead of a Bowden cable 53, any other pulling or pushing means, for example ropes, rods or the like, can be used as the transmission means.

13 and 14 show a further embodiment of an emergency actuation of a parking lock. As in the embodiment previously illustrated with reference to FIG. 12, a lever 50 is connected eccentrically via a pin 51 to a bolt 52, which in turn is connected to a Bowden cable 53. 13 shows the normal operating position, ie the emergency actuation of the parking lock is closed. The lever 50 hides an adjusting screw 60 arranged in a recess 59 for manual actuation of the clutch actuator. To seal the screw 60 or the recess 59 in

Normal operation in relation to the environment and to avoid contamination, the recess 59 is covered by a cap 61 which is arranged on the lever 50. 14 shows the lever 50 after the parking lock (43) has been actuated by folding the lever 50 over. As can be seen, the lever is asymmetrical and has a plurality of surfaces 62 which lock the lever in different positions. Alternatively, a lever configuration according to FIG. 12 can also be used here. After actuating the lever 50 in accordance with FIG. 14, the screw 60 is accessible for manual actuation of the clutch actuator and can be actuated manually, for example, using an Allen key, a screwdriver or the like. The cap 61 covers the depression 59 and thus the screw 60 in a dust-tight and / or protected against splashing water.

15 shows a solution of a parking lock emergency actuation in combination with a parking brake (30)

17 shows a gear arrangement in a motor vehicle. A four-wheeled vehicle 70 is shown in which a drive motor 71 drives a rear axle 76 with wheels 77 arranged therein via a clutch 72 and a transmission 73 and a drive shaft 74 via a differential 75. A shaft brake 78 is arranged on the drive shaft. In the present example this is designed as a conventional disc brake. Brake calipers, not shown, of the disc brake are actuated by a hydraulic system, which is not shown here. A variable pressure force can be exerted on brake shoes of the brake calipers by means of pressure cylinders (not shown), so that the braking torque of the shaft brake 78 can be controlled. Instead of a hydraulic control, a mechanical, pneumatic or electrical control can also be provided here. The brake is self-defining, which means that the braking force is applied via a spring; the brake is released by applying the hydraulic pressure. If the pressure in the system drops, the brake is closed. In this way, the function of a parking brake can be realized. The exact design of the shaft brake can vary widely, the only condition is that the device works proportionally and not only knows the position fixed / loose, as is the case for example with parking brakes with claw-like elements. Instead of the disc brake, here alternatively, for example, an eddy current brake or the like can also be used.

In the present case, clutch 72 is designed as an automatically controlled clutch, gearbox 73 is accordingly designed as an automatic manual transmission. In order to implement the function of a starting aid on gradients, the clutch is only partially closed while the vehicle is stationary and the service brakes are released, with a low starting gear being selected. If the vehicle is on a slight incline with the forward gear engaged, the sliding, partially closed clutch can be sufficient to hold the vehicle motionless on a slope. This operating state can result in an extraordinary thermal load and a corresponding wear of the clutch 72. By changing the accelerator pedal position, the driver can increase the engine speed and thus bring about a greater holding force on larger gradients. This measure additionally increases the thermal load and the wear on the clutch 72.

Instead of holding the vehicle on the slope by means of a torque applied via the sliding clutch 72, the shaft brake 78 is now closed. In addition, rolling away of the vehicle in the opposite direction, here downhill, can be prevented by a torque applied by the clutch by partially closing it. A delay in the application of a sufficient torque to bring the vehicle to a standstill can be countered by initially applying a torque by means of the shaft brake 78. If the clutch torque exceeds a predetermined torque, the vehicle speed is simultaneously below a minimum speed, at the same time the starting gear is selected or inserted, the engine is idling or at least close to idling and the brake pedal applies a braking force below a minimum force, the shaft brake 78 is closed as a starting aid or to hold the vehicle on an incline. The holding force applied by the shaft brake 78 or the torque applied to the drive shaft 74 is selected such that the holding torque generated by the shaft brake 78 adds the desired drive torque to the drive torque applied by the clutch via the transmission for holding the vehicle. The torque of the shaft brake 78 is increased until the torque to be applied by the clutch 72 becomes zero. This continues until the maximum torque that can be applied by the shaft brake 78 is reached.

As soon as the driver increases the engine speed or preselects a torque for the clutch 72 that is greater than the necessary holding torque, the shaft brake 78 is slowly opened, the clutch 72 is slowly closed, so that the vehicle starts. The starting process is ended as soon as clutch 72 is completely closed.

If the driver wishes to stop the vehicle on the slope and this is demonstrated, for example, by an increased pedal force on the service brake, the shaft brake 78 is opened in return so that the vehicle is held on the slope only by the service brake.

With the drive system shown above, a switching aid can also be implemented when driving downhill. If, for example, a downshift is made when driving downhill, there may be high torque differences on the clutch. When shifting, strong changes in the deceleration can occur and generate correspondingly high loads on the clutch. A holding torque can now be applied to the drive train by means of the shaft brake 78, so that the drive or holding torque to be generated in the new gear to be engaged can be applied for a short time. The vehicle is thus kept at a constant speed or constant or the desired deceleration during the switching process with the aid of the shaft brake 78. In this way, it is possible to synchronize the engine speed with the transmission speed after engaging the next gear in such a way that clutch 72 is more or less torque-free. If the output torque of the clutch 72 is less than 0, in other words the motor 71 prevents the vehicle from accelerating, usually referred to as overrun mode, at the same time the vehicle speed is above a minimum speed and a gear change is requested or carried out, the shaft brake 78 is activated. The braking torque generated by this is adjusted such that the moment currently applied to the clutch 72 minus the torque applied by the shaft brake 78 corresponds to the desired clutch torque on the clutch 72. This process continues until the moment currently applied to clutch 72 is zero. At this moment, the gear change is carried out and the drive motor 71 is synchronized with the transmission 73, so that the clutch 72 can be closed without torque. As soon as the gear change has ended, the gear change has been interrupted or the vehicle speed is below a minimum speed, the torque applied by the shaft brake 78 is slowly reduced. The torque applied by the drive motor 71 minus the torque applied by the shaft brake 78 corresponds to the desired torque on the clutch 72. The torque applied by the shaft brake 78 is reduced until it is zero and the brake is thus fully opened ,

All torque details in the preceding description are to be standardized either on the drive shaft 74 or the engine torque 72. This means that when considering the torque generated by the clutch 72 and the shaft brake 78, the gear ratio of the gear 73 must be taken into account.

The patent claims submitted with the application are proposals for formulation without prejudice for the achievement of further patent protection. The applicant reserves the right to claim further combinations of features previously only disclosed in the description and / or drawings.

Back-references used in sub-claims indicate the further development of the subject matter of the main claim through the features of the respective sub-claim; they are not considered a waiver of achieving self-employment, to understand physical protection for the combinations of features of the related subclaims.

Since the subjects of the subclaims can form their own and independent inventions with regard to the prior art on the priority date, the applicant reserves the right to make them the subject of independent claims or declarations of division. They can also contain independent inventions which have a design which is independent of the objects of the preceding subclaims.

The exemplary embodiments are not to be understood as a restriction of the invention. Rather, numerous changes and modifications are possible within the scope of the present disclosure, in particular those variants, elements and combinations and / or materials which are achieved, for example, by combining or modifying individuals in conjunction with those described in the general description and embodiments and the claims and features or elements or procedural steps contained in the drawings can be taken by the person skilled in the art with regard to the solution of the task and, through combinable features, lead to a new object or to new procedural steps or procedural step sequences, also insofar as they involve manufacturing, testing and working methods affect.

Claims

claims

1. Drivetrain, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with actuation, a coupling connecting this and a drive shaft, characterized in that the manual transmission has a selection device for gear selection with an arrangement of at least a first shift rail and a parking lock shift rail for actuation the parking lock and a shift finger, which is to be brought into engagement with the first shift rail and the parking lock shift rail.

2. Drive train according to the preceding claim, characterized in that several shift rails are present.

3. Drive train according to one of the preceding claims, characterized in that the shift finger can be moved by a gear actuator.

4. Drive train according to one of the preceding claims, characterized in that the displacement path of the parking lock shift rail is greater than the displacement path of the shift rails.

5. Drive train according to one of the preceding claims, characterized in that the shift mouth of the parking lock shift rail is arranged shifted relative to the shift walls of the shift rails.

6. Drive train according to one of the preceding claims, characterized in that a shift of the shift finger into the alley of the parking lock shift rail is possible in any position of the shift rails.

7. Drive train according to one of the preceding claims, characterized in that a shift of the shift finger into the alley of the parking lock shift rail is only possible in certain positions of the adjacent shift rails.

8. Drive train according to the preceding claim, characterized in that a shift of the shift finger in the alley of the parking lock shift rail is only possible when the first gear or reverse gear is engaged.

9. drivetrain, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a coupling connecting this and a drive shaft, characterized in that the parking lock can be opened by a hydraulic parking lock slave cylinder, the parking lock slave cylinder by a master cylinder hydraulic clutch system can be operated.

10. Drive train according to the preceding claim, characterized in that a first valve is arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system.

11. The drive train according to the preceding claim, characterized in that a changeover valve is arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system, the inflow of hydraulic fluid into the parking lock slave cylinder in a first switching position and outflow of hydraulic fluid from the second switching position

Parking lock slave cylinder enables.

12. Drive train according to one of the preceding claims, characterized in that a check valve is arranged between the parking lock slave cylinder and the master cylinder of the hydraulic clutch system, which prevents backflow of hydraulic fluid from the parking lock slave cylinder in the first switching position of the switching valve.

13. Drive train according to one of the preceding claims, characterized in that the hydraulic pressure required to actuate the parking lock slave cylinder is lower than the hydraulic pressure required to actuate the clutch slave cylinder.

14. Drive train according to one of the preceding claims, characterized in that it comprises a second valve with which the clutch slave cylinder can be decoupled from the hydraulic line.

15. Hydraulic system, in particular for motor vehicles, comprising a master cylinder, a slave cylinder for actuating a motor-transmission clutch and a pressure medium line connecting the same, characterized in that the master cylinder is connected via a further hydraulic line to a parking lock slave cylinder for actuating a parking lock.

16. Drive train, in particular for a motor vehicle, comprising a drive motor, a manual transmission with a parking lock with emergency actuation, a coupling connecting this and a drive shaft, characterized in that the parking lock can be opened by an actuator and additionally with a manually operated lever can be opened.

17. Drive train according to claim 16, characterized in that the emergency actuation of the parking lock is covered by the lever of the parking brake during driving.

18. Drive train according to claim 16 and 17, characterized in that the parking lock can be firmly connected to the parking brake via at least one adapter or connecting element.

19. Drive train according to claim 16 to 18, characterized in that the connecting element produces a non-positive and / or positive connection between the parking brake and the parking lock.

20. Drive train according to one of the preceding claims, characterized in that the emergency actuation for the parking lock is located in the passenger compartment.

21. Drive train according to the preceding claim, characterized in that the lever is connected via a transmission means to an actuating element of the parking lock.

22. Drive train according to one of the preceding claims, characterized in that the transmission means is arranged eccentrically on the lever.

23. Drive train according to one of the preceding claims, characterized in that the transmission means is arranged eccentrically on the lever by means of a bolt.

24. Drive train according to one of the preceding claims, characterized in that the transmission means is a Bowden cable.

25. Drive train according to one of the preceding claims, characterized in that the lever in a driving operating position covers a screw for manual actuation of a clutch actuator.

26. Drive train according to one of the preceding claims, characterized in that the screw is arranged in a recess which is covered by a cap.

27. Drive train according to claim 26, characterized in that the cap preferably consists of an elastic material.

28. Drive train according to one of the preceding claims, characterized in that the depression is dust-tight and / or waterproof covered by the cap

29. A method for controlling a drive train of a motor vehicle, the drive train comprising a drive motor, a transmission, a coupling connecting it and a drive shaft, characterized in that the drive shaft has a rotating firmly connected shaft brake and that in certain operating states an additional holding torque is applied by the shaft brake.

30. The method according to the preceding claim, characterized in that an additional holding torque is applied to start the motor vehicle on an incline by the shaft brake.

31. The method according to the preceding claim, characterized in that the sum of the holding torque applied by the shaft brake and the clutch torque of the clutch corresponds to the torque required to hold the motor vehicle on the slope.

32. The method according to any one of the preceding claims, characterized in that the shaft brake is opened completely as soon as the torque applied by the clutch is greater than that required to hold the motor vehicle

Moment.

33. The method according to any one of the preceding claims, characterized in that an additional holding torque is applied to shift the transmission on a slope by the shaft brake.

34. The method according to the preceding claim, characterized in that the additional holding torque is applied until after the engagement of a new gear, the engine speed of the drive motor is synchronized and the clutch can be closed almost without torque.