DE19926697A1 - Method and device for increasing motor vehicle operating safety with an automatic clutch has a controller with a drive cable connecting a motor to drive wheels, a friction clutch and automatic multispeed transmission - Google Patents

Abstract

If a vehicle is not ready to start and is essentially stationary with its engine (1) running and a gear engaged in a separately engaged friction clutch (3), a controller (7) completely prevents a vehicle being driven by its engine and engages a neutral gear in the transmission (5) in order to prevent the vehicle from rolling away unintentionally.

Description

The invention relates to an apparatus and a method for controlling a Motor vehicle whose connecting the engine to the drive wheels Drivetrain automatically separating the drivetrain Friction clutch and possibly an automated one Multi-speed transmission, in particular an automated manual transmission, contains whereby when the vehicle is in a non-roadworthy state is prevented from rolling away of the vehicle.

A device of this type is known in DE 197 43 674 A1. If there with the ignition off, d. H. stationary engine, and off control unit of an automated transmission and one automated clutch a driver activity, e.g. B. a brake application, is detected, the control unit is activated, for example around the clutch disengage and immediately switch on the gearbox to restart can. It can be used as a roll-away protection when the ignition is switched off stationary engine and gear engaged the previously opened clutch be closed automatically.

Furthermore, a vehicle has become known in which, when the engine is running, a gear is engaged and within one when the clutch is open predetermined time the foot brake was not applied, the motor is turned off.

Increasingly, motor vehicles are between the engine and the transmission with an automatically separating friction clutch fitted. These are single or  Multi-disc dry clutches, which are by means of an electrical or hydraulic actuator in accordance with clutch control signals one central control unit can be opened and closed. The control unit generates the clutch control signals automatically program-controlled or by signals entered by the driver.

The automated transmission can be an automatic Acting switching planetary gear automatic transmission with brake clutches or to a countershaft transmission with several over Synchronizing gears to be engaged by means of electrical or hydraulic actuators in accordance with transmission control signals from Control unit can be switched. The control unit generates the Transmission control signals are either automatically program controlled or by signals entered by the driver.

If an automatically separating friction clutch with the engine running is kept disengaged by the actuator for a long time, there is a risk that errors of the control unit, connected to it Sensors, such as current and / or position detection, the Signal transmission, actuator error or power transmission from Actuator for clutch or the like. The clutch engages slowly unintentionally and the vehicle begins to roll, which is particularly dangerous if the Driver has left the vehicle with the engine running.

Such an unwanted transmission of moments can also occur in the event of a failure of the hydraulic unit, such as pressure supply, supply lines, Valves; in the event of failure of the control unit, such as valve actuation, Control of the hydraulic pump in the case of a hydraulic actuator, Motor control with electromechanical actuator.

With hydraulic power transmission between the actuator and the Coupling with master and slave cylinders is usually in the range of  Master cylinder piston provided a compensating hole, which is not actuated clutch is released by the piston and a compensation of the enclosed between the master and slave cylinder Hydraulic medium allowed in an expansion tank.

The hydraulic medium between the master and slave cylinders is subject temperature-dependent volume changes. When closed Compensating hole then there is a change in position of the Clutch. If a position sensor on the Master cylinder is arranged, he can not recognize this change because only the slave cylinder moves.

With the clutch disengaged and the hydraulic medium under pressure can due to manufacturing tolerances hydraulic medium on the Escape the master cylinder seal and into the compensating hole. so that the volume of the hydraulic medium becomes smaller and the Position of the clutch changes. With encoder or. Integrated with the actuator The opposite cylinder can occur, namely that between Volume enclosed by master and slave cylinders increases.

This can result in the case that the one arranged on the master cylinder Position sensor outputs a signal that is not the actual one Coupling position corresponds and then by overpressing that Release system and / or the clutch is damaged. Furthermore, it can In addition, the clutch involuntarily engages partially and then the gear is no longer properly engaged or even the vehicle is not wanted starts.

A critical situation can arise when the driver drives the vehicle with the engine running and about to engage reverse gear and he or another driver gets back in later and wants to drive forward. It could also be unintentionally caused by accelerating or releasing the brakes  signal a driving request so that the vehicle is then unwanted or moved in an unwanted direction.

Another critical situation can arise if the Engine and gear engaged the hood is opened to To carry out maintenance work on the engine. The one working in front of the vehicle Person could wish to drive by pressing the accelerator pedal linkage signal so that the vehicle starts moving unintentionally and endangers the person.

Another critical situation can arise when the vehicle for example on a slope with not or not sufficiently tightened Handbrake and running engine is turned off and the vehicle unintentionally sets in motion after leaving the driver.

Is the automated clutch in a partially engaged state in one Creep mode is operable, so the creep mode may speak first a certain time delay after switching on when the Clutch is engaged very slowly. It cannot be ruled out here that you accidentally switch on the crawl mode, leave the vehicle and only after the vehicle leaves the crawl mode begins to work and the vehicle drives off unintentionally.

The object of the invention is therefore in one with an automated Friction clutch equipped motor vehicle in not ready to drive Condition and running engine even if the clutch engages unintentionally to prevent rolling away.

According to a first aspect, a Control device of the type mentioned, which, if at essentially stationary vehicle, on separately switched Friction clutch, engaged gear and running engine the vehicle  is not ready to drive, the drive of the vehicle by the engine completely prevented by shifting the transmission into a neutral state.

By switching to the neutral state, the drive transmission becomes too the wheels are prevented even when the clutch is about begins to close unintentionally for one of the reasons stated above, so that the vehicle does not accidentally roll away.

The control device preferably only switches after one predetermined period of time since the start of the non-ready condition Gearbox in neutral to prevent it from shifting too often To prevent neutral state. The time period can range from about 10 Seconds.

A sensor is preferred for determining the state that is not ready for driving provided to the actuation of a to drive the vehicle operating control element, in particular a driving or brake pedal, appeals. If the control element is not actuated, the Control device then turns the transmission to neutral preferably only after the predetermined period of time has elapsed.

Is preferred when the control element is actuated again before Switching to neutral last gear selected automatically the control device reinserted so that no further Operation by the driver is required.

The sensor is preferably one in the vehicle anyway existing accelerator pedal position sensor or brake pressure switch.

If the vehicle is not ready to drive and in neutral gearbox the engine stops for some reason, can the control device automatically again a gear, in particular the  high gear, engage to counter the vehicle Secure rolling away.

In order not to irritate the driver, preference is given to the time of the Gear selection no change by the selector lever position or a additional display of displayed gangs, d. H. it remains the last one inserted Gear in the display.

With the engine running and automatically switched to neutral The clutch can be closed again by a gearbox Compensation of the hydraulic medium between the master and slave cylinders to reach. It is also possible to leave the clutch open and only at regular intervals, about every 2 minutes, the clutch for short Time to close, about 6 seconds, especially when the vehicle is with is equipped with a dual mass flywheel. This allows one Idle rattling of dual mass flywheel and clutch effective suppress. It also shortens the time to put the gear back in, because then the gear shaft is stopped and no longer needs to be synchronized.

The control device preferably switches this when the vehicle is stationary Gearbox in neutral and then closes the clutch if since the standstill of the vehicle over a predetermined period of time Service or parking brake of the vehicle applied continuously was used, for example, in hydraulic systems with displacement sensing Master cylinder to be able to balance the hydraulic medium.

A sensor can also be used to determine that the vehicle is not ready to drive be provided on the opening state of a hood and / or door of the vehicle responds, the control device with the hood open or door switches the transmission to neutral. At the door it can are the driver's or passenger's door, or a loading door Delivery van. Laying the gear in neutral can also  if the door is closed again with the engine running, because then it is not clear whether the driver has actually left the vehicle.

To record the door operation can usually be anyway Use existing door contact switches for interior lighting.

If the hood is the bonnet of the vehicle, is a special hood contact required to open the To be able to sense the bonnet. This should be redundant, to detect a failure of a contact and / or an open one Bonnet from a not fully locked or locked Distinguish hood. Different signals from both Contacts could be used, but not gear selection or to activate at least with changed times and / or the start up to allow to lay out the aisle. Here for security reasons open bonnet, the transmission goes into neutral immediately be switched.

If the bonnet contact is not redundant, for example for cost reasons executed, the start should only after a predetermined time, for. B. 5 Seconds, thus preventing the vehicle from failing, for example of the bonnet signal, with an open bonnet permanently is displayed, remains mobile. By visual or / and acoustic warning If there is no driver activity, the upcoming start prevention to be announced.

If the conditions for gear selection are in neutral can after a predetermined time, e.g. B. a second, the driver through an optical or acoustic signal for the upcoming laying be pointed out. The warning can also be displayed after the gear has been remain active in the neutral state or in whole or in part be switched off.  

Regardless of the safety function, while the engine is running and open door always give a visual and / or acoustic warning.

A new gear should only be able to be put in again after the Driver has placed the selector lever in the neutral position, thus ensuring is that he actually the present neutral state of the transmission recognized.

In certain countries there may be a requirement that the driver in can drive away immediately in an emergency situation even with the driver's door open, if, for example, he is threatened with physical violence to leave the Vehicle is asked to steal the vehicle (criminal attack). For this purpose, the control device can be opened without any driver door Engage a delay when a driving control of the Vehicle, in particular the accelerator pedal, is operated. By pressing the The driver can immediately escape using the accelerator pedal, without having to shift gears.

Another way to determine the non-roadworthy condition is to provide a sensor based on the occupancy of the driver's seat responds, so that the control device when the driver's seat is not occupied Gearbox switches to neutral. Here there is the possibility that when the seat contact is activated again and the door is closed again last used gear is automatically re-engaged.

If the clutch is hydraulically operated, there is a possibility that the Control device when the vehicle is not ready for driving Neutral state switches when the temperature of the hydraulic fluid is a predetermined maximum temperature or a change in temperature of the Hydraulic fluid exceeds a predetermined maximum temperature change. This prevents the temperature from increasing in volume  of the hydraulic fluid gradually closes the opened clutch and the vehicle begins to roll.

In this case, preference is given to the vehicle not being ready to drive and shifting in the neutral state due to increased hydraulic temperature or -change the clutch briefly closed and then disconnected again, to balance the hydraulic fluid volume through the Allow compensating hole. The thresholds of the Changes in temperature are then selected so that, on the one hand, no overpressing the clutch takes place and on the other hand still safely disconnects the clutch.

Within the remaining distance of the master cylinder, one can Correction of the transmission characteristics of the clutch via the Temperature change take place, e.g. B. in the form of a shift of Clutch engagement point or the positions for the end positions, as long as the temperature change thresholds mentioned have not been reached, if the clutch position sensor is provided on the master cylinder.

If the clutch is operated hydraulically, it may be necessary to reduce the pump duty cycle of the hydraulic unit Master cylinder piston in the disengaged position to a stop move so that the clutch valve can leave the restricted area and leakage current can be prevented. Leak minimization takes precedence before temperature compensation - this decision can be made by the Ambient temperature of the hydraulic unit or the pump driving motor can be hit - so a correction of the Adjust the coupling position only when the stop again was left. This can result in a different threshold for the permissible temperature increase become necessary.

To recognize the change in temperature of the hydraulic fluid is a Temperature sensor required. The temperature should be as close as possible  measured on the main volume of the enclosed hydraulic medium be, for example, by a separate temperature sensor. The simplicity for the sake of it, one that is usually available anyway Ambient air temperature sensor or intake air temperature sensor whose values are used between a Engine and transmission control unit to be replaced.

The temperature can also change from a change in resistance connected solenoid valves can be determined. Since to regulate the Hydraulic pressure or the flow of a valve the current through the Valve must be set very precisely, this setting is made via a Current regulation. Here the actual current is measured and with compared to a target current value. Adjusting the control deviation the control signal is adjusted so that the control deviation becomes zero. From the control signal for a constant current, the Resistance of the solenoid coil can be calculated, and from this can be done via the known nominal resistance and the also known Temperature coefficient of the coil material on the temperature of the valve getting closed. The nominal resistance is subject to large tolerances and if a more precise absolute temperature measurement is necessary, it can Teaching in the nominal resistance at the end of the production line is necessary his.

Another way to prevent the vehicle from being accidentally rolls away, is that the control device when at essential stationary vehicle, on separately switched Friction clutch, engaged gear and running engine the vehicle is not ready to drive, the drive of the vehicle by the engine completely thereby preventing it from turning off the engine and the friction clutch closes. Through the stationary engine, the closed clutch and the the vehicle is secured against rolling away.  

This version is particularly applicable when the vehicle does not have an automatically shifting gearbox, but one by hand shifting gear. There is only one to stop the engine appropriate interface to the engine control unit required. in the In the simplest case, this can be a relay contact in the supply line Ignition key position signal for the travel position, which is normally is closed and by the clutch control unit for a predetermined Time is activated, d. H. is opened to stop the engine. This must however, be sure that the clutch control unit is not a wrong one Ignition lock signal received. However, communication can also take place both control units take place via a data interface, to transmit the shutdown command.

The control device preferably only sets after a predetermined one has elapsed first time span, about 10 seconds, since the start of not ready to drive Condition the engine.

Before this, the driver can be warned of the upcoming event Engine shutdowns are advised.

Preferably, the control device sets when tightened Vehicle parking brake only after a second predetermined Time since the start of the non-ready state, the engine is longer than the first period. This allows the driver to drive the vehicle Switch off with the engine running to warm up the engine in winter, for example while he scrapes the ice off the windows. This second time can be about 3 minutes, with an additional one Outside air temperature signal can be used for decision.

If the vehicle has an automated gearbox is equipped, there is a possibility that the control device after automatically switching off the engine a high gear,  in particular the first gear, in order in this case as well closed clutch to secure the vehicle against rolling away.

Finally, there is a possibility that the control device, if after switching off the engine and closing the friction clutch Vehicle is ready to drive again, the control device the clutch again opens, disengages the gear and starts the engine again so that the driver can continue driving without having to start the engine separately. However, this could surprise the driver very much if he drives for a longer time Absence gets back into the vehicle and suddenly the engine of starts again. Therefore, the restart should only be up to one predetermined time, about 3 minutes after the automatic shutdown be admitted again.

The invention will now be described with reference to exemplary embodiments explained on the accompanying drawings.

Fig. 1 shows a first embodiment with automated hydraulic actuation of the clutch and transmission;

FIG. 1A shows a clutch master cylinder with position sensor of the hydraulic unit 11 shown in FIG. 1;

FIG. 2 shows a second embodiment similar to FIG. 1, but with a position sensor arranged on the clutch slave cylinder;

Fig. 3 shows a third embodiment with automated electromechanical actuation of the clutch and transmission; and

Fig. 4 shows a fourth embodiment with automated electromechanical actuation of the clutch and manual transmission.

First, a first embodiment is explained with reference to FIG. 1. A motor 1 for driving a motor vehicle is connected via a single or multiple disc friction clutch 3 , possibly in combination with a dual mass flywheel, and a multi-speed manual transmission 5 to wheels of the vehicle, not shown. The clutch 3 and the transmission 5 are automated in accordance with control signals from a common central electronic control unit 7 , ie, program-controlled or as a function of operator control signals.

To control the clutch 3 , the control unit 7 is connected to a hydraulic unit 11 via a signal line 9 . The hydraulic unit 11 comprises a motor-operated hydraulic oil pump, electromagnetic control and switching valves, an oil reservoir (not shown in each case) and an integrated clutch master cylinder 13 with a compensating tank 15 , as shown in detail in FIG. 1A. The master cylinder 13 delimits, with a piston 17, a working chamber 19 which is connected via a line 21 to a slave cylinder 23 which is mechanically connected via a clutch (not shown) of the clutch 3 . By pressure supply from the hydraulic pump of the hydraulic unit 1 l via line 25 as the piston 17 moves in accordance with FIG. 1A, right under reduction of volume of the working chamber 19, against the force of a mounted in the working chamber 19 the compression spring 27 to via line 21 and the slave cylinder 23 to open the clutch 3 and thereby completely prevent torque transmission from the engine 1 to the transmission 5 . Without pressure supply from the oil pump of the hydraulic unit 11 , the piston 17 moves to the left by the pressure of a clutch release spring and the compression spring 27 according to FIG. 1A and releases a radial bore 29 in the cylinder wall which connects the working space 19 to the expansion tank 15 . Here, the clutch 3 is engaged. In the course of disengagement for disengaging the clutch 3 in accordance with Fig. 1A to the right of the piston 17 blocks the bore 29 and allows pressure to build up between master and slave cylinders 13, 23. The piston 17 is connected to a position sensor 31 , which determines the longitudinal position of the master piston 17 , which is used as a measure of the respective clutch position. The position sensor 31 is fed back to the control unit 7 via a signal line 33 .

The hydraulic unit 11 is also hydraulically connected to a selector cylinder 37 and a shift cylinder 39 via transmission control lines 35 in order to switch the transmission 5 - here in the form of a synchronized multi-shaft transmission - between several forward speed stages, a reverse speed stage and a neutral stage in response to corresponding signals from the control unit 7 can. In addition to the position sensor 31 , the control unit 7 receives signals from an engine ignition switch 41 , a gear selector lever 43 , a brake pedal position sensor 45 , an accelerator pedal position sensor 47 , a gear detection sensor 49 provided in the transmission 5 , a transmission speed sensor 51 , wheel speed sensors 53 and from the shift and the select cylinder 37, 39 associated position sensors 37 a, 39 a. Furthermore, the control unit 7 is connected to a motor control unit 55 of the motor 1 via a data bus line, and outputs signals to a diagnostic switch 57 and an acoustic or optical warning signal generator 59 .

The execution works as follows:
If, with the engine 1 running, the wheel speed sensors 53 indicate that the vehicle is stationary, the brake pedal sensor 45 indicates that the foot brake has not been actuated, the gear selector lever 43 is engaged in a forward or reverse gear, the clutch position sensor 31 indicates that the clutch 3 is engaged and has started If all of the above conditions exist, a first predetermined waiting time - here approximately 3 seconds - has elapsed, the control unit 7 emits an acoustic warning signal via the warning signal generator 59 .

The warning signal is ended by brake actuation and a corresponding signal from the brake pedal sensor 45 .

After a second waiting time has elapsed since the start of the above conditions, which is longer than the first waiting time, here approx. 10 seconds, the control unit 7 outputs a transmission control signal to the hydraulic unit 11 so that the latter can be transmitted via the hydraulic lines 35 and the control and Selector cylinder 37 , 39 sets the transmission 5 to neutral, the selector lever remaining in the previously set position, but a gear position indicator, not shown, is switched to "neutral".

The control unit 7 then outputs a clutch control signal to the hydraulic unit 11 so that it engages the clutch 5 via the master cylinder 13 , the line 21 and the slave cylinder 23 , as a result of which the master piston 17 clears the bore 29 and the working chamber 19 is connected to the expansion tank 15 .

By switching the transmission 5 to neutral, whereby the transmission input shaft is decoupled from the transmission output shaft, the drive force transmission from the engine 1 to the wheels is inevitably interrupted, so that unintentional starting of the vehicle is reliably prevented. This in turn opens the possibility of closing the clutch 3 and relieving the hydraulic system between the master and slave cylinders. A slight pressure leak between the master piston 17 and master cylinder 13 to the expansion tank 15 has no consequences, ie the clutch 3 cannot engage unintentionally and the vehicle cannot roll away.

The warning by the warning device 59 remains until the foot brake is applied or the selector lever is set to neutral.

If the driver steps on the brake, clutch 5 opens and the previously engaged gear is engaged again and the warning is switched off. Simply by pressing the accelerator pedal, you can start driving again without any further operating steps.

In addition, the system can be designed such that after switching to neutral and closing the clutch 5 , after a further waiting time, the engine 1 is switched off and the first gear is engaged in order to secure the vehicle against rolling away. By actuating the brake, the clutch 5 is opened and the engine 1 is started again.

There is also the possibility of connecting the control unit 7 to a door opening sensor 61 , a seat occupancy sensor 62 and / or a bonnet opening sensor 63 . If the driver or loading door and / or the bonnet of the vehicle is opened or the driver leaves the seat while the engine 1 is running, the vehicle is in gear, and the accelerator and brake are not actuated, the driver will leave the seat after a first waiting time - e.g. B. 3 seconds - first a warning signal is issued, and after a further waiting time the transmission 5 is set to neutral and the clutch 3 is engaged. This prevents the vehicle from moving off if the driver has left the vehicle through the driver's door or a loading door, for example, or the bonnet is open for maintenance purposes.

Another possibility is to connect the control unit 7 to a temperature sensor 65 , which is arranged as a separate sensor in the area of the hydraulic system between the clutch master and slave cylinders 13 , 23 or which measures the temperature of the ambient or intake air to the engine by one strong temperature change in the hydraulic system between clutch master and slave cylinders 13 , 23 can measure. If, while the engine 1 is running, the vehicle is stationary, the gear is engaged and the accelerator pedal is not actuated and the brake is not actuated, the sensor 65 outputs a signal which indicates that the temperature of the hydraulic system between the master and slave cylinders 13 , 23 is increasing too quickly, the transmission 5 is set to neutral and the clutch 3 closed. Due to the increasing temperature, the hydraulic medium between the master and slave cylinders 13 , 23 expands, so that the clutch 3 could disengage gradually without the position sensor 31 attached to the master cylinder 13 being able to detect this. By engaging the clutch 3 , there is a volume compensation with the expansion tank 15 , so that the signal of the position sensor 31 is correctly assigned to the position of the clutch 3 again and overpressure of the clutch 3 is avoided.

Fig. 2 shows a similar embodiment as Fig. 1, in which the same parts are provided with the same reference numerals. The essential difference from the first embodiment is that here the clutch position sensor is mounted 131 on the clutch slave cylinder 123 so that the sensor 131 always detects the proper position of the clutch 3 irrespective of temperature changes in the hydraulic system between the master and slave cylinders via the line 133rd The control unit 7 can be connected to further input and output elements, as shown in FIG. 1. With 67 a gear oil temperature sensor is designated. Otherwise the execution is the same in function and structure as the first execution.

Fig. 3 shows a similar embodiment as Fig. 1, but in which the clutch 3 and the gear 5 are actuated by electromechanical actuators which are controlled directly by the control unit 7 without hydraulic components via control lines 321 and 335 . Here, the clutch 3 is engaged and disengaged by an electromotive actuator 323 , and the transmission 5 is shifted by a selector motor 337 and a shift motor 339 . Otherwise, the design is identical in function and structure to the first design, with the same parts being provided with the same reference numerals. With 3 a the release of the clutch 3 is designated.

FIG. 4 shows a further embodiment with a hydraulically automated clutch 3 , as in the first embodiment, but with a multi-speed transmission 405 to be shifted by hand. If in this embodiment the vehicle is stationary, the clutch is disconnected 403, a gear is engaged and the brake or the accelerator pedal is not operated, the control unit 407 outputs after a waiting time, a signal to the motor control unit 59, so that this the motor 1 turns off. When the engine 1 is stopped, the control unit 407 outputs a further signal to the electromechanical clutch actuator 411 so that it engages the clutch 3 via the master cylinder 413 and the slave cylinder 423 and the vehicle is secured against rolling away by the stationary engine 1 . Identical to Fig. 1 elements are provided with same reference numerals and are not explained in more detail.

Here, the control unit 407 can additionally be connected to a handbrake sensor 476 in order to switch off the engine 1 and to close the clutch 3 only if the handbrake of the vehicle has not been applied or may not have been correctly applied for a predetermined time in the presence of the above conditions to prevent the vehicle from rolling away unintentionally even on a slope.

Claims (24)

1. Control device for a motor vehicle of which the engine (1) connecting to the drive wheels drive train a powertrain automated separating friction clutch (3) and an automated multi-speed transmission (5), in particular an automated shift transmission, contains, wherein the control device (7) then, when the vehicle is in a non-ready-to-drive condition, prevents the vehicle from rolling away, characterized in that the control device ( 7 ), when the vehicle is essentially stationary, with the friction clutch ( 3 ) switched off, the gear engaged and the engine running ( 1 ) the vehicle is not ready to drive, the motor ( 1 ) completely prevents the vehicle from being driven by switching the transmission ( 5 ) into a neutral state. 2. Control device according to claim 1, characterized in that it switches the transmission ( 5 ) into the neutral state only after a predetermined period of time since the start of the non-ready state. 3. Control device according to claim 1 or 2, characterized in that a sensor ( 45 , 47 ) is provided for determining the non-ready state, which responds to the actuation of an operating element to be operated to drive the vehicle, in particular a driving or brake pedal and when the control element is not actuated, the control device ( 7 ) switches the transmission ( 5 ) into the neutral state. 4. Control device according to claim 3, characterized in that, when the control element ( 45 , 47 ) is actuated again, it engages the gear last selected before switching to the neutral state. 5. Control device according to claim 3 or 4, characterized in that the sensor is an accelerator pedal position sensor ( 47 ) or a brake pressure switch ( 45 ). 6. Control device according to one of the preceding claims, characterized in that when the motor ( 1 ) stops when the vehicle is not ready to move and the transmission ( 5 ) is in the neutral state, a signal, in particular a gear, is again signaled by the control device ( 7 ) high gear, engaged. 7. Control device according to one of the preceding claims, characterized in that it closes the clutch ( 3 ) when the vehicle is not ready to move and the transmission ( 5 ) is in the neutral state. 8. Control device according to one of the preceding claims, characterized in that it switches the transmission ( 5 ) into the neutral state when the vehicle is stationary and the clutch ( 3 ) closes when the service or parking brake has been inactive for a predetermined period of time since the vehicle has come to a standstill the vehicle was operated continuously. 9. Control device according to one of the preceding claims, characterized in that a sensor ( 61 , 63 ) is provided for determining the non-ready to drive state, which is based on the opening state of a hood and / or door of the vehicle, in particular hood and / or driver's door and / or the loading door, and the control device ( 7 ) switches the transmission ( 5 ) into the neutral state when the hood or door is open. 10. Control device according to one of the preceding claims, characterized in that the control device ( 7 ) a predetermined time before switching the transmission ( 5 ) in the neutral state when the vehicle is not ready emits a warning signal perceptible by the driver. 11. Control device according to one of the preceding claims, characterized in that it only releases re-engagement of a gear when the driver has previously placed a gear selector lever of the transmission ( 5 ) in the neutral position. 12. Control device according to one of claims 8 to 1 l, characterized in that it engages a gear, in particular without delay when the driver's door is open, when an operating element to be operated to drive the vehicle, in particular the accelerator pedal ( 47 ), is actuated. 13. Control device according to one of the preceding claims, characterized in that a sensor ( 62 ) is provided for determining the non-ready state, which responds to the occupancy of the driver's seat and the control device switches the transmission to the neutral state when the driver's seat is not occupied. 14. Control device according to one of the preceding claims, characterized in that the clutch ( 3 ) is hydraulically actuated and the control device ( 7 ) switches the transmission ( 5 ) into the neutral state when the vehicle is not ready for driving when a temperature of the hydraulic fluid reaches a predetermined maximum temperature or a change in temperature of the hydraulic fluid exceeds a predetermined maximum temperature change. 15. Control device according to claim 14, characterized in that when the vehicle is not ready to move, the control device ( 7 ) briefly closes the clutch ( 3 ) after switching to the neutral state due to increased hydraulic temperature or change and then separates again. 16. Control device according to claim 14 or 15, characterized in that a signal from a temperature sensor ( 65 ) is used to assess the temperature of the hydraulic fluid, the temperature of the ambient air, the engine intake air or the temperature of a hydraulic control unit ( 11 ) of the clutch measures. 17. Control device according to one of the preceding claims, characterized in that it switches off the engine ( 1 ) after a predetermined period of time since switching to the neutral state and in the transmission ( 5 ) engages a gear, in particular a high gear. 18. Control device for a motor vehicle, the drive train connecting the engine ( 1 ) to the drive wheels includes a friction clutch ( 3 ) that automatically separates the drive train and a multi-speed manual transmission ( 405 ), the control device ( 407 ) when the vehicle is in is not ready to drive, prevents the vehicle from rolling away, characterized in that the control device, when the vehicle is essentially stationary, with the friction clutch ( 3 ) switched separately, the gear engaged and the engine ( 1 ) running, the vehicle is not ready to drive, the drive of the vehicle by the engine ( 1 ) completely prevented by turning off the engine ( 1 ) and closing the friction clutch ( 3 ). 19. Control device according to claim 18, characterized in that it only shuts off the engine ( 1 ) after a predetermined first period of time since the start of the non-ready state. 20. Control device according to claim 19, characterized in that when the vehicle parking brake is applied, the engine ( 1 ) is switched off only after a predetermined second time period has elapsed since the start of the non-ready state, the second time period being longer than the first time period. 21. Control device according to one of claims 18 to 20, characterized,  that the drive train is also an automated multi-speed transmission, contains in particular an automated manual transmission, and the Control device when the vehicle is not operational and after parking the engine in the transmission a gear, especially a high translate gear, engages. 22. Control device according to claim 21, characterized, that it turns off the engine when the vehicle is not in motion and the Gear engages when one to be operated to drive the vehicle Operating element, in particular a driving or brake pedal, during a predetermined period after the Motors was not operated. 23. Control device according to claim 21 or 22, characterized in that when the vehicle is after stopping the engine (1) and closing of the friction clutch (3) again running, the clutch (3) opens again interprets the response and the Engine ( 1 ) starts again. 24. A method for preventing a motor vehicle whose drive train connecting the motor ( 1 ) to the drive wheels contains a friction clutch ( 3 ) that automatically separates the drive train from starting in the non-ready state by motor drive, whereby when the vehicle is essentially stationary, Separation of the switched friction clutch ( 3 ) and running engine ( 1 ) the vehicle is not ready to drive, drive of the vehicle by the engine ( 1 ) is prevented by switching off the engine and / or a transmission ( 5 ) contained in the drive train in a neutral state is switched.