DE19619320A1 - Method and device for controlling an internal combustion engine - Google Patents

Abstract

The proposal is for a process and a device for controlling an internal combustion engine in which a predetermined number of cylinders is cut out in predetermined operating conditions to reduce consumption and pollutant emission. Besides a corresponding adjustment in the degree of cylinder filling, the ignition angle is corrected and/or the cylinders to be cut out are controlled, especially in the cut-out transition stage and when the cylinders are cut in again, in order to maintain the revolution speed selected by the driver.

Description

State of the art

The invention relates to a method and a device for controlling an internal combustion engine according to the Preambles of the independent claims.

From EP 27 865 A1 it is known, in predetermined Operating states of the vehicle or the internal combustion engine at least one cylinder one Switching the multi-cylinder internal combustion engine on and off, d. H. interrupt the fuel supply to this cylinder and to resume. To that of the internal combustion engine keep the delivered torque essentially constant, is the position of a in this known arrangement electrically controllable throttle flap in the sense compensation of the cylinder deactivation generated change in torque. Despite the change in Throttle valve position is used in this known device due to the systemic slowness of the air intervention the activation and deactivation of the cylinders is noticeable for the driver be.

It is an object of the invention to transition to an operation with cylinder deactivation and vice versa that the driving comfort is not impaired and that of the Engine torque given off even in transition is kept substantially constant.

This task is characterized by the characteristics of the independent claims achieved.

DE 42 39 711 A1 describes one method and one Device for controlling an internal combustion engine is known, where a uniform engine torque interface is used. One over this moment interface The requested torque is slowly changing Interventions (filling) and / or quick interventions (Injection suppression and ignition angle) realized. activities in connection with the shutdown of a given Number of cylinders, preferably the shutdown of one Cylinder bank, in the idle and part load range are not specified.

DE 43 34 864 A1 describes a control method or one Control device for an internal combustion engine, known which by suitable synchronization of Ignition angle correction and injection suppression of the Moment jump when switching a cylinder on or off is reduced.

Advantages of the invention

When switching on and off at least one cylinder one multi-cylinder internal combustion engine in the partial load range by coordinating the ignition, filling and Injection intervention that is delivered by the internal combustion engine Torque with unchanged pedal position and speed in  kept essentially constant. The driving comfort is therefore not affected by switching the cylinders on and off.

The use of these is particularly advantageous Procedure in connection with switching off and on Cylinder banks for engines with a large number of cylinders.

It is particularly advantageous that the driver's request (that of Driver's desired torque) regardless of the supply or Shutdown of individual cylinders is realized. Here there is no noticeable deterioration in comfort during of the dynamic process.

It is particularly advantageous that external intervention on the Internal combustion engine (for example from a Traction control or a transmission control) also implemented independently of switching off or on can be.

Further advantages result from the following Description of exemplary embodiments or from the dependent claims.

drawing

The invention is described below with reference to the drawing illustrated embodiments explained in more detail. It shows

Fig. 1 is an overview block diagram of a control apparatus for an internal combustion engine, while FIG. 2 is an overview block diagram of the procedure of the invention is illustrated. Various exemplary embodiments of the procedure according to the invention are shown in the block diagrams of FIGS. 3 to 9.

Description of exemplary embodiments

In Fig. 1, a control device is shown for a multi-cylinder internal combustion engine 10. The control device comprises an electronic control device 12 , which consists of at least one microcomputer 14 , an input 16 and an output unit 18 . Input unit 16 , output unit 18 and microcomputer 14 are linked via a communication bus 20 for mutual data exchange. The input lines 16 , the input lines 22 , 24 , 28 and 30 are supplied. The line 22 comes from a measuring device 32 for detecting the pedal position, the line 24 from a measuring device 34 for detecting the engine speed, the line 28 from a measuring device 38 for detecting the engine load and the line 30 from at least one further control device 40 , for example one Control device for traction control, for transmission control and / or for engine drag torque control. Depending on the exemplary embodiment, air mass meters, air volume meters or pressure sensors for detecting the intake manifold pressure or the combustion chamber pressure are provided for detecting the engine load. In addition to the operating variable shown, the control unit detects other variables that are essential for engine control, such as engine temperature, driving speed, etc.

An output line 42 is connected to the output unit 18 , which leads to an electrically actuable throttle valve 44 , which is arranged in the air intake system 46 of the internal combustion engine. Output lines 48 , 50 , 52 , 54 , etc. are also shown, which are connected to actuating devices for metering fuel in each cylinder of internal combustion engine 10 or are used to set the ignition angle in each cylinder.

The basic idea of the procedure according to the invention is Realization of the engine torque by coordination of Filling, ignition angle adjustment and injection suppression at Switching off or reinserting a number of cylinders, those for reducing consumption and pollutants, for example is then specified if the internal combustion engine in one predetermined (partial) load range is operated. The Decision on cylinder deactivation or - Reinstatement and its extent is preferred Embodiment based on engine load and engine speed met. Falls below the measured engine load and measured speed a predetermined limit, so a predetermined number of cylinders switched off. At The cylinders are exceeded reinstated, d. H. the fuel supply again added. According to the present invention, starting out from the driver's request in accordance with the specified number of cylinders by intervening in the firing angle and in the filling both in stationary operation as well as in the transitions that of Driver specified engine torque, engine load, filling or Performance essentially on the one specified by the driver Value held.

In Fig. 2 on the basis of a block diagram the basic structure of the internal combustion engine controller is set forth in the context of the inventive solution. In a preferred implementation, the elements shown in the block diagrams are parts of the program of the microcomputer, the blocks representing special program parts with tables, characteristic curves, characteristic diagrams and / or calculation steps.

The input lines 22 , 24 and 28 are routed to an element 100 for determining the driver's request. The driver's request determined in the following manner (cf. FIG. 3 or 4) is led via a line 102 to elements 104 and 106 , to which line 30 is also fed in each case. The elements 104 and 106 are used to select the setpoint to be specified for engine control in accordance with the supplied setpoints with regard to the driver's request and external interventions (cf. FIG. 5). The selected setpoint is led via lines 108 and 110 to calculation units 112 and 114 . The calculation element 112 calculates the correction of the ignition angle and / or the injection suppression from the supplied target value in accordance with at least engine speed and engine load (cf. FIG. 8 or 9). In an analogous manner, the calculation element 114 calculates the charge from the supplied target value in accordance with at least engine speed and engine load, which is set by actuating the throttle valve via line 42 (cf. FIG. 6 or 7). In a preferred exemplary embodiment, the calculation elements 112 and 114 are connected via line 116 to exchange data.

To reduce consumption and improve pollutant emissions, the control unit specifies the number of cylinders to be deactivated or reinserted (reduction stage) depending on the engine operating state (engine load, engine speed). In addition to this cylinder deactivation, the procedure outlined in FIG. 2 coordinates other interventions on the torque of the internal combustion engine (intervention by traction control, by a transmission control, by the driver) by adjusting the filling (slow intervention), injection and ignition angle (rapid intervention).

To set the filling, the specified cylinder deactivation and the stationary ignition angle are taken into account in the context of the calculation element 114 without additional intervention, so that the torque output by the internal combustion engine remains constant with a constant pedal position (in the stationary case), regardless of whether the cylinder is deactivated or not . The ignition angle is corrected and / or individual injections are suppressed during the dynamic process when the predetermined cylinder deactivation is implemented or when it is withdrawn, so that the torque emitted by the internal combustion engine remains essentially constant even during this dynamic process (with the pedal position being constant) (calculation element 112 ). In the preferred exemplary embodiment, ignition angle and injection intervention are synchronized in accordance with the prior art mentioned at the beginning.

To determine the setpoint specified by the driver different paths open. It is known from the Accelerator pedal angle to determine a target clutch torque. This moment becomes dependent on the accelerator pedal position and vehicle speed calculated wheel torque under Consideration of the transmission status (gear stage, Converter condition, gear loss) calculated.

Another possibility for calculating the driver target value is outlined in FIG. 3. There, a target combustion torque MISOLL (FA) specified by the driver is calculated directly from the accelerator pedal angle by interpolation between the torque requirement at idling MLL and the maximum torque MMAX.

This embodiment of block 100 is shown in FIG . The maximum torque value and the torque requirement when idling (pedal not depressed) MLL are specified as speed-dependent characteristics. In another advantageous exemplary embodiment, the torque requirement during idling (pedal not depressed) MLL represents the (speed-dependent) output of an idling speed controller. In the exemplary embodiment shown in FIG. 3, the engine speed is supplied via line 24 to the stored characteristic curve for the maximum torque 200 which reads out a maximum torque value and is conducted via line 202 to interpolation block 204 . Correspondingly, the engine speed is fed via line 24 to the stored characteristic curve 206 for the idling torque requirement, from which a value representing the idling requirement value MLL is read out and fed via line 208 to the interpolation block 204 . A preprogrammed map 210 is also provided, to which the engine speed is fed via line 24 and the accelerator pedal position is fed via line 22 . Depending on these two variables, a combustion torque corresponding to the accelerator pedal position is determined between a maximum and a minimum value in the characteristic diagram and is conducted via line 212 to interpolation block 204 . In interpolation block 204 , the setpoint is calculated as part of a linear interpolation between maximum (MMAX) and minimum (MLL) and the corresponding driver setpoint torque value is led via line 214 to a selection stage 216 . In this selection stage 216 , the setpoint torque value predetermined on the basis of the accelerator pedal actuation and, if appropriate, a corresponding setpoint torque value, which is led from a vehicle speed controller 218 via line 220 to the selection stage 216 , is the greater than the driver setpoint torque value MISOLL (FA) selected and delivered via line 220 . The setpoint torque value specified by the vehicle speed controller is calculated accordingly, taking into account the gear ratio, gearbox losses and the loss moments of the engine, on the basis of the setpoint vehicle speed specified by the driver via an operating element. The characteristic curves 200 and 206 are predefined in such a way that the idling demand value decreases to zero as the speed increases.

Another advantageous exemplary embodiment for determining the driver's request is shown in FIG. 4. In this version, a target filling value (target load) is determined instead of the target torque. The accelerator pedal position value is fed via line 42 to an interpolation stage 300 , in which the relative nominal filling value is determined by interpolation between a minimum and a maximum filling value. This value is sent over line 302 to selection stage 216 . There, the larger than the driver's desired value is selected from the correspondingly treated target value signal of the vehicle speed controller 218 and the relative filling value from the accelerator pedal position. The selected setpoint signal is routed via line 304 to a multiplication block 306 . The line 308 is supplied to this from an idle controller 310 , which determines the relative charge during idle on the basis of the engine speed and the cylinder deactivation condition supplied via the line 312 . The relative charge value determined by the idling controller is divided by the ratio of the maximum number of cylinders to the number of deactivated cylinders for correction in accordance with the number of deactivated cylinders. Then, in block 306, a percentage of the maximum fill derived from the fill value of the idle controller is determined as a correction value to determine the target fill value that goes beyond the idle value and multiplied by the driver fill value. The result, the filling setpoint TLSOLL (FA) is output via line 314 .

In addition to determining filling or torque setpoints becomes a load setpoint in other advantageous embodiments  (corresponds to the filling value), a power setpoint (calculation determined from target torque and speed), etc.

In block 106 in the path of the filling adjustment, the driver target values determined in FIGS. 3 and 4 are coordinated with target values that originate from additional interventions. Referring to FIG. 5, the line is supplied 314 and 222, a first selection stage 400, in which from the supplied desired values of each is smallest is selected. Accordingly, interventions are combined in the selection stage 400 , which can lead to a reduction in the engine torque compared to the driver's request. Such functions are, for example, traction control, transmission control or functions such as load limitation, speed limitation, speed limitation and / or torque limitation. The corresponding target values are fed to the element 400 in the dimension used in each case (filling, torque, etc.).

The respectively selected setpoint is led via line 402 to a further selection stage 404 . This passes on the larger value in each case, so that the selection stage 404 takes into account interventions which increase the engine torque compared to the driver's request. Such interventions originate from the idle control or from an engine drag torque control. The corresponding setpoints are supplied via lines 208 and 412 . A setpoint torque value for filling setting MISOLLFE or a setpoint filling value TLSOLL is then output via output line 414 to calculation block 114 .

The corresponding procedure is carried out with respect to the fuel and ignition angle intervention in block 104 (output quantity target combustion torque MISOLL or target load value TLSOLL). Only interventions that also or only affect fuel metering and / or ignition, such as traction control, idling control, etc., are taken into account.

FIG. 6 shows the operation of the calculation block 114 in a preferred exemplary embodiment. The throttle valve opening is calculated taking into account the specified cylinder deactivation. In order to achieve the target combustion torque determined according to FIG. 5 and transmitted via line 414 , the charge, ie the throttle valve setting, must be corrected when the cylinder is switched off. Taking into account the influence of the ignition angle without intervention ZWBASE and the cylinder deactivation with a predefined reduction stage REDSOL, there is an indicated engine torque MIDK for calculating the throttle valve opening according to the following equation:

MIDK = MISOLLÜ / (f (ZWOPT - ZWBASE) × (1 - REDSOL / REDMX))

where ZWOPT is the optimal ignition angle, ZWBASE the Basic ignition angle without intervention, f () that of the difference between the optimal firing angle and the optimal one Moment MIOPT related basic ignition angle dependent Efficiency curve, REDSOL the specified reduction level and REDMX is the maximum number of stages.

If half of the cylinders are switched off, REDSOL = REDMX / 2, so that the indicated engine torque MIDK is around the Factor 2 is increased.

The calculation of MISOLLFE according to the equation shown above is shown in FIG. 6. The optimum ignition angle ZWOPT is determined in a characteristic diagram 500 in accordance with the engine speed and engine load supplied via lines 24 and 26 . This ignition angle or the characteristic diagram 500 is determined with a view to an optimal efficiency of the internal combustion engine. The optimal firing angle is led to a comparison point 504 via line 502 . This is fed via line 506 to form the difference DZW of the basic ignition angle without intervention. This is formed in map 508 depending on the engine speed, engine load, engine temperature, etc. This ignition angle represents the ignition angle that would be set under the current operating conditions without external intervention, without cylinder deactivation and ignition angle correction. The difference DZW is fed from the comparison point 504 via the line 510 to the efficiency curve 512 . The output line 514 of this characteristic leads to a dividing element 516 . The output signal of the efficiency characteristic curve 512 represents a correction value of the setpoint MISOLLÜF formed under optimal efficiency, which follows from the deviation of the set ignition angle without intervention from the optimal ignition angle determined for setting the optimal efficiency of the internal combustion engine. The correction takes place in dividing element 516 according to the equation above. The result is sent via line 518 to dividing element 520 . There, a factor is supplied via line 522 from cylinder deactivation specification unit 524 , which represents the number of cylinders deactivated. The result MIDK of element 520 is led via line 526 to characteristic diagram 528 , in which a target load value TLSOLL is read out via line 530 from the target engine torque MIDK for calculating the throttle valve opening in accordance with the engine speed. This setpoint is passed on the one hand to a multiplication stage 532 and on the other hand to a comparison point 534 . The latter is also supplied with a measure of the actual load of the motor 538 via the line 536 . The actual load is measured by an air mass meter, an air flow meter, an intake manifold pressure sensor or combustion chamber pressure sensor. The difference between the target and actual load is led via line 540 to controller unit 542 . This determines a correction value for the target load value from the control deviation in accordance with a specified control strategy (e.g. PID). In the multiplication stage 532 , the target value and the correction value are multiplied and led to a further characteristic diagram 548 via an output line 546 . There, a target throttle valve position value DKSOLL is determined in accordance with the speed from the predetermined, corrected target load value. This is led via line 550 to the electrical actuating device 542 which, for example in accordance with a position control loop via line 554, adjusts the throttle valve of the internal combustion engine and thus the charge or the combustion torque to the predetermined target value by means of charge setting (the quantity of fuel to be injected becomes known determined at least from engine speed and load with a view to a predetermined air / fuel ratio).

The procedure according to FIG. 6 thus forms the target torque MIDK and the speed via the map 528 , which was measured at an optimal ignition angle, the target charge TLSOLL and finally the throttle valve target position DKSOLL. The specification of the cylinders to be switched off (block 524 ) takes place in the preferred embodiment in idle and at low load, for. B. if the target torque by the driver is less than a predetermined threshold. The cylinders are also switched off in push mode. When the accelerator pedal position is raised, the target torque for the filling increases. If this becomes so large that, for example, the calculated throttle valve opening DKSOLL exceeds a predefined speed-dependent threshold (for example 85 °), the cylinder deactivation is reversed in the preferred exemplary embodiment. In this case, the target torque MIDK is reduced by approximately half. If the system is idle again or at low load or in the coasting phase, the shutdown default is reactivated.

The realization shown in FIG. 6 only applies to the stationary case, ie for the case when the cylinders are already switched off. During the deactivation or reinsertion of the cylinders, the interventions in the filling, in the cylinders and in the ignition angle must be synchronized in such a way that as little change in the torque output by the engine as possible is noticeable before and after the cylinder deactivation. If a predetermined number of cylinders is switched off, the torque MIDK is calculated from the above equation with the new number of cylinders REDSOL switched off. The throttle valve opening that is then determined can be set immediately (abruptly) or, in the preferred exemplary embodiment, with a predetermined time ramp. This increases the measured load TL. This behavior is used for the ignition angle correction as described below with reference to FIG. 8.

In Fig. 7, a second embodiment for setting the filling in accordance with the predetermined nominal value is displayed. This exemplary embodiment is preferably to be used when the target value is a filling value.

The setpoint is supplied via line 414 . In the subsequent multiplication point 600 , the supplied target value is multiplied by factors supplied via line 602 , which represent the number of cylinders deactivated. If all cylinders are active, the factor 1 is read from the memory location 406 . If half of the cylinders are switched off, the value 2 is read out from the memory cell 606 by switching the switching element 608 . Accordingly, factors can be provided for further numbers of cylinders to be deactivated. The corrected target value is fed via line 610 to a map 612 , in which a target setting angle for the throttle valve is determined, taking into account the engine speed, if necessary. This is delivered via line 614 to positioner 616 , which adjusts throttle valve 622 according to the desired value via control line 618 and motor 620 .

In a simplified version of the procedure according to FIG. 6, the procedure shown in FIG. 7 can also be used accordingly when a target torque value is specified.

Fig. 8 shows a preferred embodiment for controlling the ignition angle and the fuel supply, in particular in the dynamic range, or to supplement the setting shown in Fig. 6 7 of the filling.

When the cylinders are switched off or replaced, the throttle valve position is changed as shown in FIGS. 6 and 7. This increases the engine load. The combustion torque MIOPT at an optimal ignition angle is estimated from engine load and engine speed in map 720 . The deviation of the ignition angle setting from the optimal setting is determined analogously to FIG. 6 in steps 700 to 714. In the multiplier 722 , a basic combustion torque MIBASE is determined from the estimated optimal combustion torque MIOPT, taking into account the influence of the ignition angle without intervention. This basic combustion torque represents the torque that is generated by the engine by setting the basic ignition angle ZWBASE.

This basic combustion torque MIBASE without intervention is compared (divided) in the dividing element 724 with the predetermined target torque in order to determine the ignition angle setting and / or fuel metering.

This moment is greater due to the increasing engine load as the target moment, a fuel intervention and / or an ignition angle correction is calculated so that the target torque is observed. This measure will Torque increase due to the change in the filling Cylinder blanking and / or ignition angle correction compensated. It is essential that during the dynamic Operation hidden cylinders are also the cylinders that switched off according to the specification of the cylinder deactivation should be. In the simplest example of a bank shutdown the cylinders on a motor bench during the dynamic process one by one according to one predetermined time course switched off. The moment transition when switched off, the ignition angle is corrected. When the moment transition is complete, it is Reduction level RED from the cylinder deactivation given. The firing angle is based on the basic firing angle set. These values are then displayed during the Maintain cylinder deactivation. Will be preferred Embodiment of cylinder deactivation in overrun (all cylinders switched off), only one is made Influenced over the filling, no correction the ignition angle. When reinserting then only reinstated the allowed cylinders.

When reinstalling, the reduction level default is set to Set value zero, d. H. all cylinders are fired. The filling becomes smaller according to the equation above, the throttle valve being immediately or with a predetermined one  Ramp is set to the new value. The measured Load and thus the detected combustion torque MIBASE sink. The ignition angle and / or the number becomes corresponding the cylinders to be replaced. With sinking The load and thus the sinking combustion moment goes Reduction level REDNEU starting from that through the Cylinder deactivation predetermined value direction zero. Also here the moment is passed between two reduction stages Ignition angle adjustment affected. If the load on the steady-state value is dynamic Process ended and the reduction level remains zero. Of the The ignition angle is reset to the basic ignition angle.

In general:

MISOLL = MIOPT × (f (ZWOPT - ZWSOL) × (1 - REDNEU / REDMX))

where ZWSOL is the ignition angle output by the correction is.

The regulation of the target torque according to this equation shown in FIG. 8 automatically results in a suitable ignition angle ZWSOL and a suitable reduction stage REDNEW when MISOLL is observed. If the accelerator pedal position and speed remain constant during the process and there is no external intervention, MISOLL remains constant.

As is known from the prior art Injection intervention and the ignition angle adjustment also for Realization of fast requirements, such as an ASR or an MSR request. Give this the target values, which are then filled accordingly, The ignition angle and fuel metering can be set. Consequently are these interventions independent of an operation with or without cylinder deactivation.  

According to the prior art mentioned at the outset Intervention of ignition angle and injection suppression see above synchronized that when changing the reduction level as little moment jump as possible.

Fig. 8 shows an advantageous embodiment of the above described procedure. As already mentioned, a comparison is made in the dividing stage 724 between the target torque MISOL and the combustion torque MIBASE. The quotient of MISOLL and MIBASE is subtracted from one in comparison stage 726 and the difference in multiplier stage 728 is multiplied by the maximum number of reduction stages REDMX. The result is then inverted in inverter 730 . The value 1 / ((1 - MISOLL / MIBASE) × REDMX) is present at the output of the inverter. According to the above equation, however, this is nothing more than the predefined reduction stage REDNEU with an optimal ignition angle. When the cylinder deactivation is active, the switching element 732 is in the position shown. Accordingly, a reduction stage REDNEW is output, which is implemented by changing the charge by interrupting the injections to the specified cylinders. Outside the phases with cylinder deactivation, the switching element 732 is in the other position, so that zero is output as the reduction stage. The setpoint torque value MISOLL is fed to a further dividing stage 736 via the line 734 . This path denotes the determination of the target ignition angle. Line 738 is fed to this dividing stage 736 . The combustion torque MIND, which is determined taking into account the current number of deactivated cylinders, is supplied on this line. This is determined by reversing the above formula. It is determined from the current number of hidden cylinders REDST by dividing by the maximum number of stages in block 740 and subtracting this quotient from 1 while multiplying in the multiplier 742 by the optimal moment. The quotient of the desired torque and the combustion torque, which was formed in element 736 , is converted via line 744 , the efficiency curve 746 , into an ignition angle change DZW. In the correction point 748 , the optimum ignition angle determined in the characteristic diagram 700 is corrected and output via line 750 as the desired angle ZWSOLL.

FIG. 9 shows a simplified exemplary embodiment in relation to the bank shutdown, in which an entire cylinder bank is shut down. In this exemplary embodiment, the driver does not specify a torque setpoint, but a filling setpoint. This is supplied via line 414 . The charge setpoint is converted into a setpoint torque value in accordance with the engine speed in a characteristic diagram 800 . In a preferred exemplary embodiment, the relative charge is multiplied by the driver by the maximum load and the air density and corrected using a filter which essentially represents the intake manifold dynamics. The combustion torque read from the characteristic map is corrected in the multiplier 802 to the target combustion torque MISOLL in accordance with the difference between the optimum ignition angle and the basic ignition angle, as was described in the other exemplary embodiment. In the dividing point 804 , the target torque MISOLL is divided by a calculated torque value MIEZA, which represents the combustion torque at an optimal ignition angle, taking into account the number of active cylinders. This combustion torque is formed from the optimal combustion torque determined in a known manner in the characteristic diagram 806 , which is multiplied in the multiplier 808 by a factor which indicates the number of active cylinders. If all cylinders are active, this factor is one; if a cylinder bank is switched off, this factor is 0.5. The corresponding selection is made via the switching element 810 . An ignition angle correction value DZW is determined from the quotients between the target combustion torque and the actual combustion torque in accordance with the efficiency function 812 . The target ignition angle ZWSOL to be set is formed by subtracting this correction value from the optimal ignition angle.

The ignition angle intervention (rapid intervention) described in FIG. 9 is activated when the cylinder deactivation is activated or when the cylinder is switched off again (switching of the switching element 810 ) and is blocked again after a certain time or depending on the load, if the load has settled and the Bank switching was successfully carried out.

If switching from operation with 12 cylinders to operation with 6 cylinders, the filling is first increased in accordance with FIG. 6. This change in charge is compensated for by ignition angle correction as part of normal engine control, so that the engine torque remains constant. When the charge has settled, the cylinders are switched off and the cylinders on a bench are switched off immediately one after the other. This reduces the combustion torque value MIEZA by half, which means that the ignition angle of the cylinders that are still fired is pulled back early. If all cylinders are deactivated, the ignition angle intervention is ended. When switching operation from 6 to 12 cylinders, the switching elements in the filling path as well as in the ignition angle correction are changed simultaneously. The deactivated cylinders are immediately switched on again. Since the filling is slowly reduced, the engine torque becomes too great at the beginning. Therefore, the ignition angle is pulled late in accordance with FIG. 9. As the load drops, the ignition angle is pulled back more and more early. If the load has settled and the intervention has ended, the target ignition angle from the calculations according to FIG. 9 is no longer taken into account.

The embodiment according to FIG. 9 is not only limited to the driver specifying a filling setpoint, but can also be carried out as a simple embodiment within the scope of the embodiment of FIG. 8.

In the preferred embodiment, in the case of Bank shutdown with each shutdown the other Cylinder bank switched off.

Claims (11)

1. A method for controlling an internal combustion engine, wherein a predetermined number of cylinders is switched off in predetermined operating states, and by influencing the filling, the torque of the internal combustion engine desired by the driver is maintained regardless of the number of cylinders switched off, characterized in that in addition to influencing the Filling in the transition phase in the event of a change in the number of deactivated cylinders, the ignition angle is additionally corrected and / or the number of deactivated cylinders is influenced. 2. The method according to claim 1, characterized in that when switching off a predetermined number of cylinders to maintain the specified torque filling to be adjusted is set, additionally in the sense a control of the generated by the internal combustion engine Torque to a predetermined value the number of corrected cylinder and / or the ignition angle corrected becomes. 3. The method according to any one of the preceding claims, characterized in that in the transition phase to Switch off the specified number of cylinders selected cylinders one by one as required the change in the filling can be switched off.   4. The method according to claim 3, characterized in that the specified torque by ignition angle correction in is essentially maintained. 5. The method according to claim 4, characterized in that with the filling installed, the selected cylinders one by one the other are switched off and the Cylinder angle correction on the fired cylinders of one after the other is withdrawn. 6. The method according to any one of the preceding claims, characterized in that a target torque from the driver, a target filling, a target load or a target performance is specified. 7. The method according to any one of the preceding claims, characterized in that the number of to be hidden Cylinder in the transition phase from the difference of predetermined target torque value and an estimated Torque value without intervention taking into account the Ignition angle influence is determined without intervention. 8. The method according to any one of the preceding claims, characterized in that the ignition angle correction related to a certain ignition angle (e.g. optimal ignition angle) in accordance with the deviation of the target torque value from one considering the cylinder blanking determined torque value at the ignition angle reference point (e.g. optimal ignition angle) is formed. 9. The method according to any one of the preceding claims, characterized in that the target value for the Driver request by interpolation from a maximum value for the torque or for the filling and one  Idling demand value for the torque or for the filling is determined. 10. The method according to any one of the preceding claims, characterized in that the filling setpoint or Torque target value by selection from driver specification and Additional functions, such as traction control, Engine drag torque control, transmission intervention, Idle control and / or by limiting functions for Speed, driving speed, load and / or Torque limitation is determined. 11. Device for controlling an internal combustion engine an electronic control unit for influencing Filling, ignition angle and injection, which in predetermined operating states a predetermined number of Shuts off cylinders and changes the filling so that the torque of the internal combustion engine desired by the driver is maintained, characterized in that the electronic control unit in addition to influencing the Filling, especially in the transition phase to Cylinder deactivation and when the cylinders are replaced, corrected the ignition angle and / or the number of controls cylinder to be hidden.