WO2008058626A1

WO2008058626A1 - Motor vehicle with a start-stop function for an internal combustion engine and operating method for the same

Info

Publication number: WO2008058626A1
Application number: PCT/EP2007/009386
Authority: WO
Inventors: Friedhelm Krake; Gerhard Landsmann
Original assignee: Gm Global Technology Operations, Inc.
Priority date: 2006-11-14
Filing date: 2007-10-30
Publication date: 2008-05-22
Also published as: DE102006053515A1

Abstract

The present invention relates to a method for operating a motor vehicle with an internal combustion engine (1), a manually shiftable manual-shift transmission (6) and a clutch (3) by means of which the internal combustion engine (1) can be connected to the manual-shift transmission (6), wherein in the presence of a stop condition, a control device (22) effects an automatic shut-off of the internal combustion engine (1) into a stop mode, and in the presence of a start condition, said control device (22) effects an automatic restart of the internal combustion engine (1). In addition to a conventional automatic restart of the internal combustion engine (1) for continuing the journey of the motor vehicle, a restart is provided if the load state of an energy accumulator (19) which can be charged by the internal combustion engine (1) falls below a minimum value during the stop mode. In order to prevent a restart taking place when the driving gear is engaged and the clutch (3) is closed, which could bring about a safety-critical driving state, it is proposed on the one hand to prompt the driver, by means of a signal, to open the clutch or to shift the transmission into the neutral position. Alternatively proposed is a shift prevention device (25) which prevents a shift of the transmission (3) from the neutral position into a driving gear position during the stop mode of the internal combustion engine (1).

Description

Motor vehicle with a start-stop function for an internal combustion engine and operating method therefor

Description

The present invention relates to a motor vehicle and a method for its operation, wherein the motor vehicle nen an internal combustion engine, a manual transmission and a clutch, by which the internal combustion engine is connected to the manual transmission, the motor vehicle between a normal operating state with running internal combustion engine and a Standby state is switched with the internal combustion engine off, wherein in the standby state, the presence of one or more turn-on conditions of a set of startup conditions is checked and in the presence of at least one turn-on condition of the set, the motor vehicle is reset by switching on the internal combustion engine in the normal operating state.

By switching off the combustion engine in certain conditions when no drive of the vehicle is required, usually during deceleration or standstill of the vehicle, the fuel consumption can be reduced.

If the driver expects a longer standstill of the vehicle, for example in front of a railroad crossing with a closed railway barrier or in front of a construction site traffic light, the driver usually switches the transmission to neutral position and then releases the clutch pedal, ie closes the clutch. Non-operation of the clutch pedal when the vehicle is at a standstill is considered in a system described in paragraph 7 in DE 102004024213 Al as a shutdown condition, when it enters the internal combustion engine is switched off. A restart of the internal combustion engine takes place when the clutch is opened, without the brake pedal is actuated, since this is interpreted as a signal that the driver wants to continue his journey.

If the motor vehicle is in the standby state for a long time or heaped up, there is the risk that a battery to be charged by the internal combustion engine will be discharged to such an extent by the electrical load applied to the battery that the remaining capacity will no longer suffice to return the internal combustion engine to the vehicle Normal operating state to restart.

In DE 199 11 736 Al it is proposed, when the motor vehicle is in the standby state and the remaining capacity of the battery falls below a predetermined value, to automatically start the internal combustion engine before the battery expires in a state in which the internal combustion engine can not be started ,

However, when the driver in the standby state accidentally shifts the transmission into a driving gear without opening the clutch, there is the risk that the vehicle will unexpectedly start when restarting. Especially if the re-start is not intentionally caused by the driver, but by an automatic, a safety-critical situation may arise.

In DE 19911736 Al, the danger is more likely to be seen in the overload of the starter motor when starting the engine when the drive gear and clutch engaged. It is therefore proposed to allow starting of the internal combustion engine when the vehicle is at standstill below a given minimum charge value of the battery only when the transmission is in neutral position. In the event that the vehicle is stationary, the internal combustion engine is switched off Minimum charge value of the battery is below and the transmission is in a driving position, the DE 19911736 Al offers no solution.

The object of the present invention is therefore to provide an operating method for a motor vehicle and a motor vehicle, in which the safety-critical situation described above can be avoided and it is ensured that the vehicle does not unexpectedly remain in the standby state for the driver.

The object is achieved by a method according to one of claims 1 and 4 and a motor vehicle according to one of claims 8 and 9.

In the context of the present invention, two methods are provided for achieving the above object. These are in each case a method for operating a motor vehicle having an internal combustion engine, a manual transmission and a clutch, by which the internal combustion engine can be connected to the manual transmission, wherein the motor vehicle is switchable between a normal operating state with the internal combustion engine running and a standby state with the internal combustion engine switched off, when in the standby state

the presence of one or more turn-on conditions of a set of turn-on conditions is monitored, and

- When there is at least one turn-on condition of the set, the motor vehicle is reset by switching back on the internal combustion engine (1) in the normal operating state.

In the method according to claim 1, in the standby state, it is further detected whether there is an exclusion condition that simultaneously the clutch is closed and a gear is engaged in the manual transmission, and the return to the normal operation state is inhibited as long as the exclusion condition exists. To avoid the driver is surprised, when the exclusion condition occurs, a perceptible by a driver of the vehicle signal is generated so that it can cancel the exclusion condition by opening the clutch or switching to a neutral position in a timely manner.

Complementary to the monitoring of the switch-on condition in the standby state, the monitoring of a switch-off condition preferably takes place in the normal operating state in order to automatically switch to the standby state when it occurs.

A minimum requirement for the presence of the shutdown condition may be that the transmission is in neutral.

In the method according to claim 4, the presence of a switch-off condition is further monitored in the normal operating state and the motor vehicle is placed in the ready state when the switch-off condition, the switch-off comprises the requirement that the transmission is in neutral position, and the insertion of a Gangs is locked while the vehicle is in standby mode. In this way, the occurrence of the exclusion condition described above is prevented from the outset.

In the latter method, the shutdown condition may further include the request that the clutch is closed.

The shutdown condition includes in both methods expediently the requirement that the vehicle is at a standstill.

There may be several startup conditions, one of which must be met in order to initiate the transition to the normal operating state. A first turn-on condition may include as a minimum requirement that the clutch is open. This usually opens the driver to insert a drive to continue the drive of the vehicle. The opening of the clutch is thus understood as a signal that the driver wants to continue his journey. Optionally, the first start condition may include further requirements, for example that a gear is engaged in the transmission, and / or that an accelerator pedal is actuated.

A second connection condition is expediently that the charge state of a rechargeable by the internal combustion engine energy storage device falls below a minimum value. This minimum value must cover the energy requirements that a starter needs to start the internal combustion engine.

To achieve the object of the present invention further motor vehicles are provided, which are each preferably designed to carry out one of the operating methods described above.

The motor vehicles have an internal combustion engine, a manual transmission, a clutch, by which the internal combustion engine with the manual transmission is connectable, and a control device for switching the motor vehicle between a normal operating condition with the engine running and a standby mode with the engine off, the automatic in the presence of a shutdown condition Disconnection of the internal combustion engine causes a stop operation and causes an automatic restart of the internal combustion engine in the presence of a start condition. The control means is arranged to monitor, in the standby state, the presence of one or more turn-on conditions of a set of turn-on conditions, to detect whether there is an exclusion condition that the clutch is simultaneously closed and a gear is engaged in the manual transmission, and if at least one turn-on condition is present of the sentence and absence of the exclusion condition that Reset motor vehicle by switching back on the internal combustion engine (1) in the normal operating state.

Furthermore, in one of these motor vehicles, a signaling device is provided, which is connected to generate a driver-detectable signal upon occurrence of the exclusion condition in the standby state with the control device.

In the other motor vehicle, the control device is set up to monitor the presence of a switch-off condition in the normal operating state and to put the motor vehicle in the standby state when the switch-off condition occurs, the switch-off condition comprising the requirement that the transmission (6) is in neutral position , and a shift prevention device (25) is provided to prevent the engagement of a gear in the transmission (6) during the standby state.

Preferably, the first and second motor vehicles have a neutral position sensor in communication with the controller that detects whether or not the transmission is in neutral, the neutral position sensor in the transmission, on the shift lever, or on one of the shift lever and the transmission Shift lever mechanism is arranged.

Preferably, the control device forms at least part of an engine control unit of the motor vehicle. However, the control device may be a control device independent of the engine control unit.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

1 is a schematic representation of the drive unit of a first embodiment of a motor vehicle according to the present invention;

Fig. 2 to

4 shows flowcharts for illustrating an operating method for a motor vehicle with the drive unit shown in FIG. 1;

5 is a schematic representation of the drive unit of a second embodiment of a motor vehicle;

Fig. 6 to

8 shows flowcharts for illustrating an operating method for a motor vehicle with the drive unit shown in FIG. 5.

Fig. 1 shows a schematic representation of a drive unit of a motor vehicle not shown. The drive unit comprises an internal combustion engine 1, the crankshaft 2 of which can be connected to a transmission input shaft 4 of a manual transmission 6 via a clutch 3. A transmission output shaft 7 is connected via a drive train 8 with wheels 9 of the motor vehicle. The opening and closing of the clutch 3 takes place with a clutch pedal 11 to be actuated by the driver. The driver selects a driving gear or the neutral position (idling) of the transmission 6 via a shift lever 13. A driving gear can be a forward gear or a reverse gear.

The drive unit of the motor vehicle further includes a clutch sensor 14, which detects a closing and opening of the clutch 3. The clutch sensor 14 may be configured as a switch. A neutral position sensor 16, which is in the 6 gears or in a shift lever 13 and the transmission 6 connecting, not shown shift lever mechanism is arranged, detects whether the transmission 6 is in neutral position or is connected in a drive. The neutral position sensor 16 can also be designed as a switch. A motion sensor 18 on the powertrain 8 determines whether the vehicle is moving or at a standstill.

The motor vehicle further includes an energy storage 19 for electrical energy. This energy storage, usually a commercial 12V motor vehicle battery can be charged by means of a generator 5 on the engine 1.

By way of an optical and / or acoustic signaling device 20, for example on an instrument panel in the vehicle cabin, the driver can be requested to bring the transmission 6 into neutral position by means of the shift lever 13.

The internal combustion engine 1, the clutch sensor 14, the

Neutral position sensor 16, the motion sensor 18, the battery 19 and the signal generator 20 are in communication with a controller 22. The controller may be implemented by programming a conventionally existing engine controller 22 to perform the tasks of the controller described below in addition to its conventional functions. The controller 22 controls the operations described below with reference to FIGS. 2 to 4.

FIG. 2 shows a possible switch-off routine for switching off the internal combustion engine 1 shown in FIG. 1 when a predetermined switch-off condition comprising a plurality of requests is satisfied. The shutdown of the internal combustion engine 1 serves to save fuel when a drive of the vehicle is not required by the internal combustion engine, for example when the vehicle is at a standstill. According to FIG. 2, in step S1 it is first checked whether the internal combustion engine 1 is switched on. If this question is answered in the affirmative, it is checked in step S2 whether the vehicle is at a standstill, ie whether the vehicle speed is zero. The query is carried out by the control device 22 to the motion sensor 18 in the drive train 8. If the question is answered yes, is queried in step S3 via the clutch sensor 14, whether the clutch 3 is closed, or whether the clutch pedal 11 is released. If the question is answered in the affirmative, it is checked in step S4 whether the transmission is in neutral position. This is done by requesting the neutral position sensor 16. If this question is answered in the affirmative, the control device 22 effects a shutdown of the internal combustion engine 1 and a transition to a standby state in step S5. The shutdown of the engine takes place for example by switching off a fuel pump, not shown.

If one of the questions in steps S2 and S3 with

No answered, the query returns to step Sl and the engine 1 remains on.

The shutdown routine shown in FIG. 2 only shows one example of possible shutdown condition requirements. However, a shutdown can also take place when other than the requirements mentioned, as described for example in DE 102004 024 212 Al or DE 10 2004 024 213 Al, are met.

If it is determined in step S 1 in step S 1 that the internal combustion engine 1 is already in the standby state, the control device 22 changes over to the restart routine shown in FIG. 3.

In step Sil is checked via the clutch sensor 14, whether the clutch 3 is open, that is, whether the clutch pedal 11 has passed through. If this question is answered in the affirmative, the internal combustion engine 1 is restarted in step S14. The restart takes place, for example, by switching on the fuel pump and actuating a starter 10 shown in FIG. 1, which rests against the battery 19 and whose need for electrical energy is covered exclusively by the battery 19.

In addition to the query in step S <b> 1, the restart condition for restarting the engine 1 may include another request which is checked in the broken line step S <b> 12, namely, whether a running gear is engaged, which can be detected by the neutral position sensor 16.

If the query Sil and possibly the query S12 answered No, the controller 22 returns to step Sl, and the internal combustion engine 1 remains switched off.

The restart routine shown in Fig. 3 only shows one

Example of possible requirements for a connection condition. However, a restart of the internal combustion engine can also take place if other than the above requirements are met, as described for example in DE 10 2004 024 212 Al or DE 10 2004 024 213 Al.

FIG. 4 shows another restart routine that runs concurrently with the restart routine shown in FIG. if the question in step S1 is answered no, i. when the engine 1 is already turned off and is in the standby state.

In step S41 is first queried whether the driver during the standby state with the shift lever 13 a driving gear, for example, the reverse gear or one of

Forward gears, has turned on. For this purpose, the controller 22 makes a request to the neutral position sensor 16. Will If the question is answered in the affirmative, ie if a driving gear is engaged, a request is made to the clutch sensor 14 in step S42 as to whether the clutch 3 is open, ie whether the clutch pedal 11 has passed. If yes, the engine 1 is restarted in step S43. The step S43 thus corresponds to step S14. The passage of the clutch pedal 11 and the insertion of a driving gear are thus interpreted as signals that the driver wants to continue his journey with the motor vehicle.

If the question is answered in the negative at step S42, i. If the driver does not pass the clutch pedal 11, i. without opening the clutch 3, a drive, so it is requested via the signal giving means 20 by means of an optical and / or acoustic signal to bring the transmission by means of the shift lever 13 in neutral position.

In step S45, the neutral position sensor 16 is asked if the transmission 6 is in the neutral position, i. whether the driver has brought the transmission 6 to the signal in neutral position. If this is the case, i. If this question is answered in the affirmative, it is checked in step S46 whether the charge state of the battery 19 has fallen below a minimum value. If this is the case, the internal combustion engine 1 is automatically restarted in step S47. If the minimum value does not fall below, the query returns to step S41. An automatic restart will not be performed.

If the question is answered in the negative at step S45, i. If the transmission 6 is switched to a driving gear, then the query returns to step S42.

With the automatic restart in step S47 it is ensured that the battery 19 always has a sufficiently high charge state, so that, for example, the internal combustion engine 1 can be restarted at all or consumers attached to the battery 19, such as a not shown conditioning or on a 6V socket, such as a cigarette lighter, fitting external cooling device can be sufficiently supplied with electrical energy even when the vehicle is stationary.

Steps S41, S42, S44 and S45 ensure that an automatic restart due to the state of charge of the battery takes place only when either the clutch pedal 11 has been depressed or the transmission 6 is in neutral position. Namely, would an automatic restart with the drive gear engaged and released clutch pedal 11, i. closed clutch 3, this could allow the vehicle to roll on and cause a safety-critical driving condition of the vehicle.

If the driver has not engaged during the standby mode, i. if the question is answered in the negative at step S41, the query immediately proceeds to step S46. A critical driving state is not to be expected in an automatic restart of the vehicle, since the transmission 6 is in neutral position.

The operating method according to the invention thus comprises a safety procedure which proceeds as follows: as soon as the driver switches the transmission into a driving gear in the stand-by state without passing through the clutch, he is requested by a signal of the signal-generating device 20 to bring the transmission 3 into neutral position. A restart of the internal combustion engine 1 which is required later due to an insufficient charge state can then be carried out safely.

When the driver receives the signal of the signaling device 20 without engaging the clutch pedal 11 when engaging a driving gear in the standby state, he can respond thereto not only by disengaging the gear, but also by passing the clutch pedal 11. This would lead to the restart of the engine 1 according to the above description. Alternatively, you can the restart can also be linked to the fulfillment of a further requirement, such as the actuation of an unillustrated accelerator pedal.

Fig. 5 shows a drive unit of a second embodiment of a motor vehicle. In contrast to the vehicle of FIG. 1, this has a shift prevention device 25 which, when activated, prevents shifting of the transmission 6 from the neutral position to a running gear position. A signaling device 20 as in the embodiment of Fig. 1 is not present here. The shift prevention device 25 may be arranged in the transmission 6 itself or on the shift lever 13 with the transmission 6 connecting shift lever mechanism. The switching prevention device 25 and the control device 22 communicate with each other.

FIG. 6 shows a switch-off routine, which comprises an additional step Sβ in comparison to FIG. In this step S6, the control device 22 activates and activates the shift prevention device 25 so that the driver can no longer shift the transmission 6 into a driving gear in the stop mode. The transmission thus remains in the neutral position, in which the driver, the transmission 3 at standstill of the vehicle and before releasing the clutch pedal 11, i. brought before closing the clutch 3.

FIG. 7 shows a restart routine having an additional step S13 compared to the restart routine of FIG. 3, in which the controller 22 drives and deactivates the shift inhibitor 25 after the driver has passed the clutch pedal 11 to continue driving, ie the clutch 3 has opened, ie the query in step Sil is answered yes. With the deactivation of the shift prevention device 25, the driver can switch the transmission 6 back into a drive to continue driving. FIG. 8 shows a restart routine for the internal combustion engine 1 when the internal combustion engine is to be restarted automatically due to a minimum value for the state of charge of the battery during the stop mode.

If it is determined in step Sl of Fig. 6 that the engine 1 is turned off, i. is already in the standby state, the query goes to step S21 of Fig. 8 on whether the charge state of the battery 19 has fallen below a minimum value. If this question is answered in the affirmative, the internal combustion engine 1 for recharging the battery is automatically restarted in step S22. A demand as in the restart routine of Fig. 4 after the position of the clutch 3 or the transmission 6 is not necessary here, since a switching of the transmission 6 in a driving gear during the standby state by the switching prevention device 25 is generally prevented. A critical driving state in an automatic restart of the internal combustion engine 1 is prevented in this way.

The shutdown routines shown in FIGS. 2, 6 may comprise a further query (not shown), namely whether the charge state of the battery 19 is equal to or greater than a further, second minimum value, which is preferably selected to be greater than the first in the turn-on routines of FIG 4 and 8 described minimum value. With this query, the transition to the standby state is prevented from the outset if the charge state of the battery is so low that an automatic restart of the motor would be necessary after a short standstill. Reference list

Internal combustion engine 1 Crankshaft 2

Coupling 3

Transmission input shaft 4

Generator / Alternator 5

Transmission 6 Transmission output shaft 7

Drive train 8

Wheel 9

Starter 10

Clutch pedal 11 shift lever 13

Coupling sensor 14

Neutral position sensor 16

Motion sensor 18

Battery 19 Signaling device 20

Control device 22 Sehalt prevention device 25

Signaling device 27

Claims

Patent claims

1. A method for operating a motor vehicle with an internal combustion engine (1), a manual transmission (6) and a clutch (3) by which the internal combustion engine (1) with the manual transmission (6) is connectable, wherein the motor vehicle between a normal operating condition with the internal combustion engine running (1) and a standby state with the internal combustion engine (1) switched off, in which case in the standby state

monitoring the presence of one or more turn-on conditions of a set of turn-on conditions,

- It is detected whether an exclusion condition exists, according to the same time, the clutch is closed and a

Gear is engaged in the manual transmission, and

- In the presence of at least one turn-on condition of the set and absence of the exclusion condition, the motor vehicle by switching back on the internal combustion engine (1) in the normal operating state is reset, characterized in that in the standby state further

- Upon the occurrence of the exclusion condition, a perceptible by a driver of the vehicle signal is generated.

2. The method according to claim 1, characterized in that in the normal operating state, the presence of a shutdown condition is monitored and in the presence of the shutdown condition, the motor vehicle is placed in the standby state.

3. The method according to claim 2, characterized in that the

Shutdown condition includes the request that the transmission (6) is in neutral position.

4. A method for operating a motor vehicle with an internal combustion engine (1), a manual transmission (6) and a clutch (3) through which the internal combustion engine (1) with the manual transmission (6) is connectable, wherein the motor vehicle between a normal operating state with the internal combustion engine (1) and a standby state with switched off internal combustion engine (1) is switchable, in which in the normal operating state - the presence of a shutdown condition is monitored and

- In the presence of the switch-off condition, the motor vehicle is placed in the standby state, and in the standby state

- the presence of one or more turn-on conditions of a set of turn-on conditions is monitored, and

in the presence of at least one turn-on condition of the set, the motor vehicle is returned to the normal operating state by the internal combustion engine (1) being switched on, characterized in that the switch-off condition comprises the request that the transmission (6) be in neutral position and that the insertion of a Gangs is locked while the vehicle is in standby mode.

5. The method according to claim 4, characterized in that the shutdown condition includes the requirement that the clutch (3) is closed.

6. The method according to any one of the preceding claims, characterized in that the shutdown condition includes the requirement that the vehicle is at a standstill.

7. The method according to any one of the preceding claims, characterized in that the turn-on condition is present when the charge state of a charging of the internal combustion engine Baren energy store (19) falls below a minimum value.

8. The method according to any one of the preceding claims, characterized in that the turn-on condition is present when the clutch (3) is opened.

9. Motor vehicle, in particular for carrying out the method according to one of claims 1 to 3 or one of claims 5 to 8, as far as dependent on claim 1, with a

Internal combustion engine (1), a manual transmission (6), a clutch, by the internal combustion engine (1) with the manual transmission (6) is connectable, and a control device (22) for switching the motor vehicle between a normal operating condition with running internal combustion engine (1) and a standby state with the internal combustion engine (1) being set off, in the standby state

to monitor the presence of one or more turn-on conditions of a set of turn-on conditions;

- To detect whether an exclusion condition exists, according to the simultaneous clutch is closed and a gear is engaged in the transmission, and

if there is at least one connection condition of the sentence and no exclusion condition exists

Switching the motor vehicle back into the normal operating state by switching the internal combustion engine (1) back on, characterized by a signaling device (20, 27) which is connected to the control device (22) in the standby state when the exclusion condition occurs in order to generate a driver-detectable signal.

10. Motor vehicle, in particular for carrying out the method according to claim 4 or one of claims 5 to 8, as far as

Claim 4 back, with an internal combustion engine (1), a manual transmission (6), a clutch through which the Combustion engine (1) with the manual transmission (6) is connectable, and a control device (22) for switching the motor vehicle between a normal operating state with running internal combustion engine (1) and a standby state with the internal combustion engine (1), which is arranged in the Normal operating condition to monitor the presence of a shutdown condition and to put the motor vehicle in the standby state in the standby state, and to monitor the presence of one or more turn-on conditions of a set of start conditions and in the presence of at least one turn-on condition of the set, the motor vehicle by turning on the engine (1) to return to the normal operating state, characterized in that the switch-off condition includes the request that the transmission (6) is in neutral position, and that a switching prevention device (25) for Ve rhindern of inserting a gear in the transmission (6) is provided during the standby state.

11. Motor vehicle according to one of claims 8 to 10, characterized in that with the control device (22) in communication neutral position sensor (16) which detects whether the transmission (6) is in neutral position or not, in the transmission ( 6), on a shift lever (13) or on a the shift lever (13) and the transmission (6) connecting shift lever mechanism is arranged.

12. Motor vehicle according to one of claims 8 to 11, characterized in that the control device (22) is integrated in an engine control unit.