DE4302500B4 - Method for operating a motor vehicle and motor vehicle - Google Patents

Abstract

Method for operating a motor vehicle with
an internal combustion engine,
one of these downstream, the nonuniformities of the engine torque balancing flywheel,
at least one switchable clutch between the internal combustion engine and the flywheel and / or a switchable clutch between the flywheel and a downstream transmission, wherein an automatic control of the switching operation of the clutches is provided,
wherein a motor quench is performed after opening the transmission-side clutch, and wherein the engine quenching via a clutch actuation and / or via a device for engine quenching takes place with a certain time delay,
characterized,
that the time delay of engine stalling - the off-delay - varies depending on the accelerator pedal operation made in a past period, and
in that, for the calculation of the turn-off delay, the speed of the accelerator pedal movement (accelerator angle changing speed) and the accelerator pedal position (accelerator angle α _GP ) are shared.

Description

The The invention relates to a method for operating a motor vehicle according to the preamble of claim 1.

Farther the invention relates to a motor vehicle according to the preamble of Claim 16.

For normal operation of an internal combustion engine having a motor vehicle include changing pulling and coasting phases, possibly with short downtime, such as traffic lights or other reasons. From the DE-OS 27 48 697 it is known to turn off the engine at certain operating conditions for the purpose of fuel economy. In a special way, this is done there by separating the machine by means of an additional clutch of a downstream flywheel. Due to the usual with internal combustion engines with reciprocating speed fluctuations during a revolution, this separation of the flywheel to stop the engine is sufficient. The restarting is done in a simple manner by closing the clutch, the rotating flywheel entrains the engine and so in the shortest time to start it again. For engines with lower speed fluctuations, such as those with higher numbers of cylinders or two-stroke engines also required at the same time with the clutch actuation ignition or fuel cut can be made.

In another way, the engine without a separate disconnect clutch between crank mechanism and flywheel conventionally, z. B. by influence the Gemischbildner, shut down and then via an electric motor starter be put back into operation.

The activity the clutch and thus the shutdown of the engine or conventional drivetrain the opening the starting and shifting clutch and the subsequent stopping of the engine is automated and subject to certain criteria, such as the purpose fuel economy, ride comfort or driving safety. So it is known to operate the clutch and a subsequent engine quenching to effect, if no Zugbetrieb exists and the flywheel rotates at a minimum speed. The clutch operation and the engine quenching takes place with a certain time delay, to different driver-dependent operating habits for the To compensate for accelerator pedal. From DE patent application P 41 14 688.3 It is also known, the delay of engine quenching dependent on from the engaged gear or a correspondingly assigned speed to vary. In the same patent application are other possibilities for influencing the switch-off delay shown.

From the DE 30 26 489 A1 is a drive unit for motor vehicles, wherein as a criterion for disengagement of a clutch, the exceeding of a predetermined value of a closing direction extending throttle or accelerator pedal angle change over time or an accelerator pedal closing speed is provided.

The DE 36 41 243 C2 relates to an electrical setpoint generator for an electronic accelerator pedal system with an accelerator pedal, for which a position-dependent restoring force is provided, wherein when passing a certain position, a different restoring force than otherwise applies.

task It is the object of the present invention to delay engine stall to different driver habits and routes to improve driving safety, ride comfort and fuel economy adapt.

The solution This object is achieved by a method according to the new claim 1 and a motor vehicle according to the new claim 16 achieved.

In the calculation of the switch-off delay goes Accordingly, the driver and distance-dependent accelerator pedal movement or Position with one. In particular, the ride comfort and the energy balance (Fuel economy) of the vehicle are improved.

Concrete it is particularly important that either the accelerator pedal position at a certain time or the movement the accelerator pedal are used to calculate the switch-off delay. Possible is also a shortcut both factors.

to execution of the method, the accelerator pedal is a device for detection and transmission assigned to its current position. This device can be configured in various ways, for example as Potentiometer, incremental encoder or as a series of multiple switches dependent on of the desired At dissolution level. A downstream electronic control unit receives and processes the information for accelerator pedal operation and calculates the required switch-off delay.

Further Features of the invention are the rest claims removable. Advantageous embodiments The invention will be described below with reference to drawings and diagrams explained in more detail. It demonstrate:

1 An arrangement of Teilaggragaten in a motor vehicle for carrying out the method according to the invention,

2 another arrangement of sub-aggregates, similar to the one in 1 .

3 an illustration of the components supplying information to a control unit,

4 a flow chart for the determination of intermediate values for the calculation of a switch-off delay,

5 a flowchart for calculating the switch-off delay using the according to 4 determined intermediate values,

6 a representation of an accelerator pedal with a device for defining a particular course of the restoring force,

7 a path-force diagram for the gas pedal according to 6 .

8th a representation of an accelerator pedal with three associated switches,

9a a special design of an accelerator pedal according to the invention in a plan view,

9b a cross section through the accelerator pedal according to 9a along the line IX - IX, in an illustration with an attached shoe.

It will first be referred to 1 , An internal combustion engine 10 is a flywheel 11 and then a gearbox 12 downstream. Between the transmission 12 and the flywheel 11 is a clutch K1 and between the flywheel 11 and the internal combustion engine 10 provided a clutch K2. The clutch K1 is actuated during a switching operation, while a release of the clutch K2 causes a standstill or a shutdown of the internal combustion engine, due to the speed fluctuations. The functions of the clutches K1, K2 are automated and dependent on one in the 2 centrally located control unit. This processes various information relating to the vehicle according to specific criteria and controls the clutches accordingly.

In a similar way shows 2 an arrangement with only one clutch K1 between the flywheel 11 and the transmission 12 , Again, the clutch operation is automated. In addition, engine quenching is provided by influencing mixture formation or ignition. Clutch actuation and engine stopping are via the control unit in 3 performed.

The connection of the engine takes place in the arrangement according to 1 by opening the clutch K1, closing the clutch K2 and then soft closing the clutch K1. In the arrangement according to 2 becomes the engine 10 Tempered by an already existing, not shown electric motor starter. With respect to these and other details of the background of the invention, reference is also made to the German patent application P 41 14 688.3.

3 shows the already mentioned above control unit with this associated and influenced by this or this influencing sensors, switches and ancillaries. One of the important tasks of the control unit is the actuation or activation of the clutches K2 and / or K1 according to specific criteria and evaluation of all available information. The clutches K1, K2 are directly actuated by the coupling servo drawn to the right of the control unit. Furthermore, the controller affects the also drawn right injection pump to a safe shutdown of the engine 10 to ensure. Also possible are embodiments with a control only for the clutch K1 ( 2 ). Information-providing switches and sensors are connected to the control unit around it. These are the battery for controlling the battery voltage, the engine and the drive shaft speeds, the position of the ignition switch, the position of the shift lever for the transmission 12 with a gear information, the position of an accelerator pedal via a potentiometer, an incremental encoder or multiple switches, a steering angle, a value of a turn signal switch, values for brake pressure switch, brake light, trailer plug switch, tilt switch, handbrake switch, wheel speed sensors left and right and sensors for longitudinal and lateral acceleration. The stated criteria, measured values and sensors can influence in any combination an algorithm provided in the control unit for determining an optimal switch-off delay. For the present invention of particular importance is the determination of the accelerator pedal position and the wheel speeds and the longitudinal and lateral acceleration.

In the following, the influence of the accelerator pedal operation on the switch-off delay, that is explained in more detail on the delay in stopping the internal combustion engine. A shutdown is basically possible and useful at idle or in overrun, possibly in conjunction with a clutch operation. As soon as such a time is reached, the period of time calculated for the switch-off delay begins to run. In addition to in conjunction with the 3 described there In particular, the accelerator pedal actuation should influence the switch-off delay. The 4 and 5 describe simple processes of this influence. First to 4 :
Considered are an accelerator pedal angle α _{GP of} a past time period and the speed of an accelerator angle change, expressed in terms of difference α _GF at time N minus α _GP at time N-1, for simplicity. The accelerator angle α _GP is measured every tenth of a second, recorded and compared with the next value. If the gas pedal angle α _GP does not change, as a result of which the difference is 0, the value α _GP (n) is stored in an intermediate memory 1. In this case, it is possible to speak of a constant gas pedal angle over a certain period of time. The operation continues until two consecutive values are identical again and the value in buffer 1 is correspondingly overwritten. In this way, there is always information about the last constant accelerator pedal position.

If the difference α _GP (n) -α _GP (n-1) is positive, this difference (not one of the two values) is stored in the buffer 2. In this way, there is always information about the speed or "violence" of the last performed accelerator pedal operation. Finally, a check of the difference takes place to see whether it is unequal to 0 over a longer period. As such a period, for example, 20 sec. into consideration. If the difference for more than 20 sec. is not equal to 0, the value of the buffer 1 is set to 0. This ensures that temporally further past constant accelerator angle α _GP do not enter into the calculation of the switch-off delay. The intermediate memory 1 and 2 are preferably in the control unit ( 3 ) arranged.

According to 5 From other parameters, a certain switch-off delay AV1 has already been calculated. Suitable functions or sensors are in connection with the 3 been called. The values Z1 and Z2 stored in the latches 1 and 2 are now multiplied by certain factors F1 and F2 and used to calculate the switch-off delay. By means of the factors F1, F2, a normalization and weighting of the values Z1 and Z2 also takes place with respect to the turn-off delay AV1 serving as an input variable. First, a switch-off delay AV2 is calculated using the in the 5 mentioned formula. The value Z1 and thus the last constant accelerator angle α _GP has a negative effect on the switch-off delay. The greater the accelerator angle α _GP , the smaller the calculated turn-off delay AV2. Background for this is the consideration that after a greater acceleration, that is, in time for a larger constant accelerator pedal angle, the engine can be turned off earlier, or because in the opposite case too fast shutdown n should be avoided n. Just small absolute accelerator angles indicate a restless flow of traffic at low speeds. Too early and too frequent shutdowns would rather worsen the vehicle's energy balance.

Out the switch-off delay AV2 is using the stored in the buffer 2 difference Z2 the switch-off delay AV3 calculated. In this case the context is exactly the opposite. A bigger difference - a bigger value Z2 - results an extension the switch-off delay AV3. A bigger difference means a greater rate of change the accelerator pedal angle and thus more violent accelerator pedal movements. In such a case, the switch-off delay should be extended. This takes into account that so-called sporty drivers who perform more violent accelerator pedal movements, too early and frequent shutdown as a loss of comfort can feel.

Also can such a driving style alone due to a specific traffic situation be required.

The last ascertained value AV3 is now set as a switch-off delay time for conditions that are otherwise present for a switch-off, compare last box in FIG 5 ,

The method described above for influencing the switch-off delay by the accelerator angle α _GP and by a difference between successive accelerator pedal angles is particularly simple and can be varied in various ways. Thus, the accelerator angle α _{GP can} also be determined and recorded at other time intervals, for example every one-hundredth of a second. The accelerator angle α _GP is defined as constant if it remains unchanged over a period of one tenth to two tenths of a second. With an angle determination every one-hundredth of a second, a corresponding number of intermediate values must be buffered and compared with each other. Also conceivable is a period of 0.5 to 1 sec. for determining a constant accelerator pedal angle.

The difference formation described takes into account the last occurring positive difference α _GP (n) -α _GP (n-1). In a modification of this, it may also be provided to use the amount of the difference or to determine the penultimate difference or a difference over a longer period or to determine the largest difference within a certain period. Other possibilities are conceivable.

The the test carried out, whether the difference is over longer Time is non-zero, as one of many possibilities also omitted to simplify the procedure.

The Values Z1, Z2 basically go linear in the calculations. Nonlinear, nonlinear for example, quadratic dependencies. The factors F1, F2 must in dependence of the desired Weighting and normalization selected become. After all is the time in seconds for the turn-off delay AV1 also changed only in seconds become. For the case that one the factors F1, F2 is set to zero, finds the corresponding Value Z1 or Z2 no consideration. As favorable is considered, the value Z2 stronger to weight as Z1 and corresponding to the factor F2 relative to F1 select.

The described determination of the accelerator pedal angle α _GP or the difference between two successive accelerator pedal angles is also possible when using individual switches arranged in the region of the accelerator pedal. The number of switches used correlates with the resolution accuracy. In a particularly simple embodiment, according to the 7 . 8th two or three switches S1, S2 and S3 provided. The accelerator is in the 6 to 9b designated GP. In the area of the switch S1, the accelerator pedal GP is in the neutral position, that is to say idling with the permissibility of stopping the internal combustion engine after a calculated switch-off delay. The switches S1 to S3 may be in addition to or instead of the potentiometer or incremental encoder on the accelerator pedal. Upon activation of the switch 2, the accelerator pedal is still in an idle position. A shutdown of the internal combustion engine is no longer allowed. The switch S3 is in this particular case for the shutdown without meaning, but causes the control of a visible for the driver upshift or full load display. However, it is also possible to calculate an accelerator pedal change rate corresponding to the value Z2 in FIG 5 based on the elapsed time between different switches, such as from switch 1 to switch 2 or switch 2 to switch 3 or switch 1 to switch 3. Also, multiple switches may be provided. Similarly, a set over a longer period switch can represent a constant accelerator pedal angle.

The 6 . 7 show a particularity with respect to the restoring force of the accelerator pedal GP. In addition to a return spring not shown, which acts on the accelerator pedal with a restoring force, a device is provided which generates an additional restoring force for a specific accelerator pedal angle α _GP and a reduced restoring force for another angle. In the 7 the entire return force F _GP is applied via the accelerator pedal angle α _GP. The device is geometrically arranged so that the reduced restoring force on withdrawal of the accelerator pedal adjusts immediately when the switch 2 passes. The driver receives in this way via the gas foot, the information that the idle is reached, a shutdown of the engine, however, can not be done. For this, the accelerator pedal must first be taken back. In this way it is possible for the driver to influence the otherwise automated engine stall depending on the traffic. 6 shows a possibility for generating such a restoring force curve. Between the accelerator GP and a body part 13 is a piston-cylinder unit with a piston 14 and a cylinder 15 arranged. The piston has an annular constriction 16 on. Inside the cylinder 15 is a spring-loaded ball 17 arranged, which at an accelerator pedal movement of the constriction 16 is happening. After entering the ball 17 in the constriction 16 the results in the 7 represented Kraftenke F1.

Similarly, instead of the described device also be provided on a stop special contour along sliding spring plate. Not shown is an addition to the arrangement according to 8th , Thereafter, a manually operated switch is provided in the control area of the driver, by the further activation of the switch S2 differentiations are possible. For example, an additional switch can be arranged with two or three different positions on a steering column. It is assumed that in the position switch 2 engine quenching does not take place, however, there is an idle. Based on the steering column switch described can now be decided whether the clutch, for example, the clutch K1, opens and thus there is a freewheel. A second possibility is that the clutch remains closed. A third possibility consists in a fuel cut-off of the engine when the clutch is closed, such as a mountain brake. A equipped with the functions of the steering column switch described can also without the arrangement according to the 6 to 8th be provided. It is only important that a motor quenching is excluded.

The 9a . 9b show a simple way to influence the engine quenching. At the gas pedal GP is laterally, preferably right a safety edge 18 arranged. This is due to a clockwise rotation of the gas foot 19 acted upon. As switching logic can be provided that upon activation of the safety edge 18 engine quenching does not take place even when idling. Exactly then, the previously described steering column switch or a For this analog switch find use.

In all embodiments may be provided in place of the accelerator pedal and a throttle in the output tract with means for determining the time-dependent position thereof. The calculated switch-off delay can be set according to 3 continue to be affected by a current acceleration value. This can be determined from sensors for determining the longitudinal and / or transverse acceleration. Such sensors are in the 3 symbolically shown below the clutch servos to the right of the control unit. With a large lateral acceleration, the switch-off delay should be increased. This allows a speedy driving without loss of comfort due to premature engine silencing. In particular, a negative longitudinal acceleration, that is, sudden strong braking should also increase the turn-off delay. Again, it is about improving the ride comfort and avoiding too early engine quenching in a speedy or sporty driving style. Advantageously, the braking time is also evaluated, to the effect that a longer braking time causes a further extension of the switch-off delay.

In Vehicles with certain equipment, such as anti-lock braking system or slip control wheel speed sensors are provided. About this will be in a further embodiment a value corresponding to a curve radius is calculated and influenced the switch-off delay used. For example, the turn-off delay becomes special lengthened tight corners or even set to infinity, as it is expected that the output a tight cornering again a vehicle acceleration take place should. A motor quench would delay this or worsen the energy balance of the vehicle unnecessarily.

10

Internal combustion engine

11

Inertia

12

transmission

13

body part

14

piston

15

cylinder

16

Einschnürrung

17

Bullet

18

Safety Edge

19

Gasfuss

K1

clutch

K2

clutch

GP

accelerator

S1

switch

S2

switch

S3

switch

F1

power sink the restoring force

Claims (19)

Method for operating a motor vehicle with an internal combustion engine, one of these downstream, the nonuniformities of the engine torque balancing flywheel, at least one switchable coupling between the engine and the flywheel and / or a switchable coupling between the flywheel and a downstream transmission, wherein an automatic control of the switching operation the clutches is provided, wherein a motor quenching is performed after opening the transmission-side clutch, and wherein the engine quenching via a clutch actuation and / or via a device for stopping the engine with a certain time delay, characterized in that the time delay of the engine quenching - the Switch - off delay - varies depending on the accelerator pedal operation that has occurred in a past period of time, and that the speed for calculating the switch - off delay Accelerator pedal movement (accelerator angle change rate) and the accelerator pedal position (accelerator angle α _GP ) are used in common. Method for operating a motor vehicle according to Claim 1, characterized in that for the calculation of the switch-off delay, the Speed a bigger impact exercises. Method according to claim 1 or 2, characterized that continuously - continuously or discreet - the respective accelerator pedal position corresponding values, preferably measurable voltages of a potentiometer, signals of an incremental encoder or positions of various switches, determined and stored and calculate the shutdown delay based on one or more of these values becomes. A method according to claim 3, characterized in that for the calculation of the switch-off delay of the last over a certain period constant value of the accelerator pedal position (accelerator angle α _GP ) is used. Method according to claim 4, characterized in that that as a period for determining a constant value less than 1 second, in particular less than 0.5 seconds, preferably 1/10 to 2/10 seconds are used. Method according to one or more of claims 1 to 5, characterized in that for the calculation of the deceleration delay the speed of the accelerator pedal movement (accelerator angle change rate) is used at a certain time or as an average over a certain period or as an average over a certain range of values. Method according to one or more of claims 1 to 6, characterized in that the accelerator pedal GP more, at least However, two switches S1, S2 are assigned, depending on the accelerator pedal position are activated and that the engine quenching only when activating a specific switch (S1) depending on from a certain accelerator pedal position and preferably after one certain switch-off delay is made. Method according to one of claims 1 to 7, characterized that upon activation of a particular switch (S2) or switch state, a Engine quench suppressed becomes. Method according to claim 8, characterized in that that in suppressed Engine quenching over another, especially manually operated switch a selection potential clutch states and / or engine load conditions - in particular Idle or fuel cut - is made. Method according to one or more of claims 1 to 9, characterized in that instead of the accelerator pedal position a Throttle position or movement is evaluated. Method according to one of claims 1 to 10, characterized that the time delay of engine quenching - the switch-off delay - depending on of mutually comparable output values on both sides of Vehicle arranged wheel speed sensors varies. Method according to one of claims 1 to 11, characterized that the time delay of engine quenching - the switch-off delay - depending on varies from the vehicle transverse and / or vehicle longitudinal acceleration. Method according to claim 12, characterized in that that the turn-off delay dependent on from the duration of a particular negative vehicle acceleration varied. Method according to one of claims 1 to 13, characterized that an accelerator pedal (GP) or a throttle valve means for recording and transmission assigned to the current position of the same or the same is. Method according to claim 14, characterized in that that the device for collecting and transmitting the current Position of the accelerator pedal (GP) or throttle a potentiometer, an incremental encoder or a series of at least two switches is. Motor vehicle with an internal combustion engine, one this subordinate, the nonuniformities of the engine torque balancing flywheel, at least one switchable coupling between the internal combustion engine and the flywheel and / or a switchable coupling between the flywheel and a downstream Transmission, where an automatic Control of the shift operation the couplings is provided wherein a motor quenching After opening the transmission-side clutch is feasible, and wherein the engine quenching via a clutch Control and / or over a device for engine quenching with a certain time delay feasible is characterized, that engine quenching dependent on from a current accelerator pedal position is vornehmbar, the accelerator pedal (GP) a position-dependent Restoring force has, in such a way that when passing a certain position another restoring force (F1) as the rest occurs. Motor vehicle according to claim 16, characterized in that in that at least one switch (S2) is assigned to the gas pedal, which one in dependence of the accelerator pedal position can be activated or a specific switching state assumes that the changed Restoring force when pressed the accelerator pedal (GP) occurs immediately upon passing the switch (S2), and that the switch in the activated state, a motor quenching suppressed. Motor vehicle according to claim 16 or 17, characterized in that for generating a modified restoring force from the accelerator pedal (GP) to be actuated body with a special contour and a hereby cooperating spring-loaded body, in particular one with a constriction ( 16 ) and a spring-loaded ball ( 17 ) passing piston ( 14 ) are provided. Motor vehicle according to one or more of claims 16 to 18, characterized by a manually operated switch, in particular a steering column switch, by the suppressed engine quenching a activity the transmission side coupling possible is, and by preferably also a fuel cut of the internal combustion engine possible is.