DE10335401B4 - Method for starting an internal combustion engine - Google Patents

Abstract

Method for starting an internal combustion engine (1), in particular a vehicle, wherein a first-time injection of fuel into a cylinder (5, 10, 15, 20) of the internal combustion engine (1) for a starting process and then a first-time combustion in the cylinder for the starting process (5, 10, 15, 20), characterized in that a first operating variable of the internal combustion engine (1) is evaluated for the first combustion in the cylinder (5, 10, 15, 20) for the starting process and that at least one is the Second operating variable of the internal combustion engine (1) that influences combustion is adapted as a function of the evaluation for at least the subsequent combustion of the same starting process in the or in at least one further cylinder (5, 10, 15, 20).

Description

State of the art

The invention is based on a method for starting an internal combustion engine according to the preamble of the main claim.

Methods for starting an internal combustion engine, in particular a vehicle, are already known. It is known, for example, that a direct start is performed in which fuel is injected directly into the cylinders of an internal combustion engine without the use of a starter. For this purpose, on the basis of the discharge position of the parked engine, a low-standing cylinder is identified, which is positioned, for example, about 90 degrees crank angle to the upper Zündtotpunkt. In this cylinder takes place at the start time, the injection of fuel with the engine stopped and after the mixture has formed the ignition. The engine run-up then happens automatically without the operation of a starter within the next two to three burns. For example, a very high engine temperature is critical for a direct start, because then only a small amount of air or oxygen is present in the combustion chamber. The energy that can be generated with the first injections is directly proportional to the amount of oxygen present in the combustion chamber. Also critical are unknown parameters, such. B. the fuel properties. Thus, the mixture formation in the combustion chamber of the corresponding cylinder takes place differently depending on the fuel properties, for example, depending on the use of winter or summer fuel.

During the conventional engine start by means of a starter, a start adaptation is performed. Here, by evaluating the engine speed increase during the starting process, a recognition of the quality of combustion, and thus to achieve an adaptation of the fuel quality. It is for certain or known conditions such. As starting temperature, injection quantity, etc., the engine run-up over a certain number of burns observed. If, for example, "bad" fueled fuel, this leads to a poorer mixture formation. Thus, less vaporized fuel is available for combustion. The result is too lean a mixture in the combustion chamber and thus a bad engine run-up. The start adaptation would be here at a wake enrichment, d. H. When enriching the mixture, enrich the air / fuel mixture immediately after the start and at the start enrichment of the subsequent start.

From the DE 101 11 928 B4 a method for starter-free starting is known in which the position of a piston is determined and injected fuel into the combustion chamber of that cylinder and ignited immediately thereafter, the piston is in a working phase, wherein in the further course of the starting process still in the same power stroke immediately after the Ignition of the fuel injected into the cylinder in the working phase fuel fuel in the combustion chamber of another cylinder is injected whose piston is in an intake phase.

From the DE 198 35 045 C2 For example, there is known a method of starting an internal combustion engine in which a combustion chamber containing combustion air is identified prior to starting, and wherein the crankshaft is in a position corresponding to a working stroke of the associated piston and fuel is injected the internal combustion engine is stopped so that a piston is in the power stroke.

From the EP 1 464 832 B1 is a method for starting an internal combustion engine is known in which during the start phase in the first expansion stroke of at least one cylinder is a combustion, wherein before the start phase, the oxygen concentration in the working cylinder is determined, and in dependence on a fuel quantity to be burned is metered.

From the DE 100 43 695 A1 a method for determining a hot start situation in an internal combustion engine of a motor vehicle is known.

From the DE 101 46 504 B4 For example, an ignition timing control apparatus is known in which an ignition timing correcting means corresponding to a cam phase deviation corrects the basic ignition timing when the engine is in the uniform combustion mode and the stratified combustion mode.

Advantages of the invention

The object of the present invention is to enable a quick and comfortable engine start under all operating conditions, in particular with changing fuels. This object is achieved by a method having the features of claim 1. The subclaims form further developments of the method.

The inventive method for starting an internal combustion engine having the features of the main claim has the advantage that a first operating variable of the internal combustion engine for the first time for the startup combustion in a cylinder of the internal combustion engine is evaluated and that at least one combustion influencing second operating variable of the internal combustion engine in dependence of the Evaluation is adapted for at least one subsequent combustion of the same starting process in or in at least one other cylinder. In this way, a start adaptation of the second operating variable can already be carried out for the current starting process, so that the starting characteristics of the internal combustion engine can already be improved for the current starting process. In this way, a faster and more comfortable engine start under all operating conditions, especially with changing fuels, perform. In this case, in particular, the fuel properties can be taken into account in the current starting process, which is particularly advantageous after a refueling operation and an associated change in the fuel properties.

The measures listed in the dependent claims advantageous refinements and improvements of the main claim method are possible.

It is particularly advantageous if a motor speed representative for the first combustion of the cylinder in the cylinder is selected as the first operating variable, and if during the evaluation the engine rotational speed representative of the first combustion in the cylinder for the starting process is compared with a predetermined threshold value. In this way, the evaluation can be carried out particularly easily on the basis of an engine speed signal.

A further advantage results when the maximum engine speed determined for the first combustion is selected as the engine rotational speed representative of the combustion process for the first time in the cylinder. In this way, the representative engine speed can be determined particularly easily and without additional sensors using a mathematical maximum value search.

A further advantage results if the operating variable of the internal combustion engine influencing the combustion is selected to be a value representative of an air / fuel mixture ratio. In this way, the combustion during the starting process can be particularly effectively adapted to the operating conditions of the internal combustion engine, in particular the fuel properties.

This can be done simply by enriching the air / fuel ratio when the engine speed representative of the initial combustion in the cylinder for the startup process is less than the predetermined threshold and when the air / fuel ratio is leaned out when the engine exhausted for the starting process, the first time combustion in the cylinder representative engine speed exceeds the predetermined threshold.

However, this can also be achieved in a simple manner by adapting the air / fuel mixture ratio as a function of the engine speed representative of the combustion of the cylinder in the cylinder which is the first time for starting, by means of a characteristic diagram.

A further advantage results when the ignition variable is selected as the at least one combustion variable influencing the combustion of the internal combustion engine. In this way, the combustion during the starting process also particularly effective to the operating conditions of the internal combustion engine, in particular the fuel properties, adapt.

This can be done simply by shifting the firing angle early if the engine speed representative of the first-time combustion in the cylinder for the startup process falls below the predetermined threshold and if the firing angle is retarded, if that for the starting operation first combustion in the cylinder representative engine speed exceeds the predetermined threshold.

However, this can also be done in a simple manner by adjusting the ignition angle as a function of the engine speed representative of the combustion of the cylinder in the cylinder which is the first time for the starting process, by means of a characteristic diagram.

A further advantage results if the ignition angle is additionally adjusted as a function of the position of the cylinder before the first injection. In this way, the combustion during the starting process can be more effectively adapted to the operating conditions of the internal combustion engine, in particular the fuel properties.

drawing

Embodiments of the invention is illustrated in the drawing and explained in more detail in the following description. Show it 1 a schematic view of an internal combustion engine in the form of a block diagram, 2 a flowchart for an exemplary sequence of the method according to the invention, 3 a speed-time diagram for a motor run-up and 4 a flowchart for an alternative embodiment.

Description of the embodiments

In 1 features 1 an internal combustion engine, for example a vehicle. The internal combustion engine 1 includes an internal combustion engine 55 , which should be designed in this example as a gasoline engine. The internal combustion engine 55 is about an air supply 25 Fresh air supplied. It is in the air supply 25 one from a motor control 35 controlled throttle 30 arranged to provide a desired air supply during operation of the internal combustion engine 1 for example, depending on one at a in 1 not shown accelerator pedal given driver's request. In the example below 1 includes the internal combustion engine 55 four cylinders 5 . 10 . 15 . 20 , The internal combustion engine 55 may alternatively comprise more or fewer cylinders. The combustion chamber of the internal combustion engine 55 is through the combustion chambers of each cylinder 5 . 10 . 15 . 20 educated. According to the example 1 is for every cylinder 5 . 10 . 15 . 20 one injection valve each 41 . 42 . 43 . 44 provided, is injected via the direct fuel into the combustion chamber of the respective cylinder. Further, for each cylinder 5 . 10 . 15 . 20 one spark plug each 51 . 52 . 53 . 54 provided in the combustion chamber of the respective cylinder 5 . 10 . 15 . 20 To ignite located air / fuel mixture and thus initiate combustion of the air / fuel mixture. Both the injectors 41 . 42 . 43 . 44 as well as the spark plugs 51 . 52 . 53 . 54 be from the engine control 35 for setting a predetermined injection quantity or a predetermined ignition timing in each case individually controlled. The injection quantity can be for each cylinder 5 . 10 . 15 . 20 from the engine control 35 be set individually, for example, to set a predetermined air / fuel mixture ratio. The ignition timing can be for each cylinder 5 . 10 . 15 . 20 from the engine control 35 be individually specified, for example, to implement a predetermined depending on the accelerator pedal position driver request torque. At the internal combustion engine 55 is still a speed sensor 45 arranged in the manner known in the art, the speed of the internal combustion engine 55 , ie the engine speed, detected and sent to the engine control 35 forwards. That during the combustion of the air / fuel mixture in the individual cylinders 5 . 10 . 15 . 20 formed exhaust gas is in an exhaust line 50 pushed out. In the exhaust system 50 is a lambda sensor 40 arranged, which measures the oxygen content in the exhaust gas and the measured value to the engine control 35 forwards. The engine control 35 can from the measured value for the oxygen content, a common actual value for the air / fuel mixture ratio in the combustion chambers of the individual cylinders 5 . 10 . 15 . 20 determine in a manner known to those skilled in the art.

The following is a starting process of the internal combustion engine 1 considered. This is in 2 an example of a flowchart shown. The starting process takes place without starter. It is initially based on the discharge position of the parked engine 55 identified a favorable cylinder. Such a low-standing cylinder has a piston position of about 90 degrees crank angle after the upper Zündtotpunkt. In this cylinder takes place at the start time, the injection with the internal combustion engine 55 and after completion of air / fuel mixture formation in this cylinder, the ignition of the mixture. The engine will then start up automatically without the use of a starter within the next two to three or four burns. Such a boot process is referred to as a direct start.

For each of these first burns of the direct start, a value is set for the air / fuel mixture ratio to be set, wherein these predefined values can be learned from previous starting processes, for example also with a starter start, or applied to a test stand. Thus, a first value L1 for the first injection or combustion, a second value L2 for the second injection or combustion, a third value L3 for the third injection or combustion, and a fourth value L4 for the fourth injection or combustion , The individual injections are performed in a direct start in succession in different cylinders, if more than one cylinder is present. The order of use of the different cylinders for the injection is determined by the crankshaft position of the individual cylinders.

After the start of the program, the software and / or hardware in the engine control 35 can be implemented, reads the engine control 35 from one in 1 not shown memory at a program point 100 the current application values L1, L2, L3, L4 for the adjusted air / fuel mixture ratio of the individual injections or burns of the direct start. Subsequently, the engine control searches 35 those cylinders whose piston position comes closest to the direct start ideal position of 90 degrees crank angle after the top dead center and causes direct injection into that cylinder. For this purpose, the engine control system controls the injection valve of this cylinder as a function of the throttle position, ie the set air supply, and the first application value L1 for setting a corresponding injection time in order to implement the first application value L1 for the air / fuel mixture ratio in this cylinder. After a predetermined time after completion of the injection, the engine controller controls 35 the selected cylinder associated spark plug for ignition of the present in the associated combustion chamber air / fuel mixture. Subsequently, this air / fuel mixture is burned. The speed sensor delivers 45 continuously during the entire starting process, a speed signal to the engine control 35 , so also during the first burn at program point 100 , Subsequently, becomes a program point 105 branched.

At program point 105 checks the engine control 35 whether the determined during the first combustion maximum engine speed is less than a first predetermined threshold nmot0. If this is the case, then becomes a program point 110 otherwise it becomes a program point 115 branched. In 3 is a speed-time diagram for the engine ramp-up. The speed n is plotted in revolutions per minute over the time t in seconds after the starting time at which the first injection takes place. The effect of the first combustion extends from the start time t = 0 to a first time t1, which is approximately 0.13 seconds and represents a first speed minimum nmot1 'in the course of the first combustion. To determine the first speed maximum nmot0 'in the course of the first combustion evaluates the engine control 35 the course of the speed signal of the speed sensor 45 in the range from t = 0 to t1. If nmot0 'is less than nmot0 then becomes program point 110 branches, otherwise becomes program point 115 branched. The first speed maximum nmot0 'is representative of the engine speed that occurs in the course of the first combustion.

At program point 110 the second application value L2 is increased by a second difference amount DL2, which leads to an extension of the injection time for the second injection and thus to an enrichment of the air / fuel mixture in the corresponding cylinder. In addition, the third application value L3 can also be increased by a third difference amount DL3, which leads to an extension of the injection time for the third injection and thus to an enrichment of the air / fuel mixture in the corresponding cylinder. In addition, the fourth application value L4 can also be increased by a fourth difference amount DL4, which leads to an extension of the injection time for the fourth injection and thus to an enrichment of the air / fuel mixture in the corresponding cylinder. In addition, for a subsequent direct start, the first application value L1 can also be increased by a first difference amount DL1, which leads to an extension of the injection time for the first injection and thus to an enrichment of the air / fuel mixture in the corresponding cylinder. Subsequently, the further injections are carried out on the basis of the changed application values L2, L3, L4. Subsequently, this becomes a program item 120 branched.

At program point 115 checks the engine control 35 whether the determined during the first combustion maximum engine speed nmot0 'is greater than a second predetermined threshold value. If this is the case, then becomes a program point 135 otherwise the program is exited and the further injections are made on the basis of the application values L2, L3, L4 read from the memories. The second predetermined threshold value is greater than the first predetermined threshold value. The first predetermined threshold value and the second predetermined threshold value can be suitably applied, for example, on a test bench, wherein a satisfactory engine run-up is ensured in the region between the first and second predetermined threshold values for the first combustion.

At program point 135 the second application value L2 is reduced by the second difference amount DL2, which leads to a shortening of the injection time for the second injection and thus to a leaning of the air / fuel mixture in the corresponding cylinder. In addition, the third application value L3 can also be reduced by the third difference amount DL3, which leads to a shortening of the injection time for the third injection and thus to a leaning of the air / fuel mixture in the corresponding cylinder. In addition, the fourth application value L4 can also be reduced by the fourth difference amount DL4, which leads to a shortening of the injection time for the fourth injection and thus to a leaning of the air / fuel mixture in the corresponding cylinder. In addition, for a subsequent direct start, the first application value L1 can also be reduced by the first difference amount DL1, which leads to a shortening of the injection time for the first injection and thus to a leaning of the air / fuel mixture in the corresponding cylinder. Subsequently, the further injections are carried out on the basis of the changed application values L2, L3, L4. Subsequently, becomes the program point 120 branched. The lowering of the application values L1, L2, L3, L4 can also take place with other difference amounts than with the increase of the application values L1, L2, L3, L4 at program point 110 the case is.

At program point 120 checks the engine control 35 whether the direct start was successful, ie, for example, whether in the course of the fourth combustion the desired idle speed was reached. If this is the case, then becomes a program point 125 otherwise it becomes a program point 130 branched.

At program point 125 initiates the engine control 35 an override at program point 100 From the memory read application values L1, L2, L3, L4 with the program point 110 or at program point 135 changed application values and storing the so changed application values in the memory for a subsequent direct start. Afterwards the program is left.

At program point 130 become at program point 100 from the memory read adaptation values L1, L2, L3, L4 remain unchanged and are thus available for a subsequent direct start. Afterwards the program is left.

Alternatively, at program point 110 to dispense with the adaptation of the third application value. Instead, after the second injection or combustion, the engine rotational speed representative of the second combustion could be compared, for example, in the form of the rotational speed maximum nmot2 'occurring in the course of the second combustion, with a third predetermined threshold value. According to 3 For example, the effect of the second combustion extends from the first time t1 to a second time t2 in FIG 3 is about 0.22 seconds. If the speed maximum nmot2 'occurring in the course of the second combustion falls below the third predetermined threshold value, then the third application value L3 is increased by the third difference amount DL3. If appropriate, then the fourth application value L4 can also be increased by the fourth difference amount DL4. Alternatively, however, the fourth application value L4 can also be adapted in a corresponding manner after a corresponding evaluation of a rotational speed maximum occurring in the course of the third combustion. The effect of the third combustion extends according to 3 from the second time t2 to a third time t3, which is about 0.27 seconds. In this way, the adaptation values can be adapted even better to the engine run-up during the direct start.

Alternatively, could also be correspondingly at program point 135 to dispense with the adaptation of the third application value. Instead, after the second injection or combustion, the engine speed representative of the second combustion could be compared, for example, in the form of the speed maximum nmot2 'occurring in the course of the second combustion, with a fourth predetermined threshold value. The fourth predetermined threshold value is greater than the second predetermined threshold value. If the speed maximum nmot2 'occurring in the course of the second combustion exceeds the fourth predetermined threshold value, the third application value L3 is reduced by the third difference amount DL3. If appropriate, the fourth application value L4 can then also be lowered by the fourth difference amount DL4. Alternatively, however, the fourth application value L4 can also be adapted in a corresponding manner after a corresponding evaluation of a rotational speed maximum occurring in the course of the third combustion. In this way, the adaptation values can also be better adapted to the engine run-up during the direct start. The third predefined threshold value and the fourth predefined threshold value can be suitably applied, for example, on a test bench, whereby a satisfactory engine run-up is ensured in the range between the third and the fourth predefined threshold value for the second combustion.

4 shows an example flowchart for an alternative embodiment. After starting the program, the engine control system determines 35 as above to program point 100 described the four adaptation values L1, L2, L3, L4 from the memory. Subsequently, becomes a program point 205 branched.

At program point 205 initiates the engine control 35 the first injection using the first adaptation value L1 as described above. Subsequently, becomes a program point 210 branched.

At program point 210 determines the engine control 35 as described above, the first speed maximum nmot0 '. Subsequently, becomes a program point 215 branched.

At program point 215 determines the engine control 35 from a characteristic field or from a characteristic as a function of the determined first speed maximum nmot0 ', a first assigned correction value for the first application value L1, which, however, comes into effect only in a subsequent direct start, a second assigned correction value for the second application value L2, which for the subsequent injection or combustion is used in the current direct start, a third associated correction value for the third application value L3, which is used for the subsequent injection or combustion in the current direct start, and a fourth associated correction value for the fourth application value L4, which for the nachnachnachfolgende injection or combustion in the current direct start is used. Subsequently, becomes a program point 220 branched.

At program point 220 corrects the engine control 35 the four adaptation values L1, L2, L3, L4 with the respectively assigned correction value, which depends on the determined first speed maximum nmot0 'can be positive or negative, additive. Thus, the correction values may be greater the further the determined first rotational speed maximum nmot0 'lie outside the range enclosed by the first predetermined threshold value and the second predetermined threshold value, the correction values being positive if the determined first rotational speed maximum nmot0' is below the first predetermined threshold value and wherein the correction values are negative if the determined first speed maximum nmot0 'is above the second predetermined threshold value. Subsequently, becomes a program point 225 branched.

At program point 225 initiates the engine control 35 an override at program point 200 From the memory read application values L1, L2, L3, L4 with the program point 220 corrected application values and storing the so changed application values in the memory for a subsequent direct start. Afterwards the program is left.

Alternatively, the correction of the third adaptation value L3 and of the fourth adaptation value L4 can also be carried out correspondingly with the aid of a characteristic diagram or a characteristic after a corresponding evaluation of the speed maximum nmot2 'determined in the course of the second combustion, wherein the fourth adaptation value L4 also applies a corresponding evaluation of the determined in the course of the third combustion speed maximum can also be corrected in a corresponding manner with the aid of a map or a characteristic.

The maps or characteristics used can be suitably applied, for example, on a test bed.

In the two exemplary embodiments described above, the operating variable of the internal combustion engine influencing the combustion was used 1 selected an air / fuel mixture ratio and adapted after evaluation of a first combustion in a direct start with direct injection for the subsequent burns. Additionally or alternatively, as a combustion-influencing operating variable of the internal combustion engine 1 also the ignition angle or ignition timing for the individual cylinders 5 . 10 . 15 . 20 to get voted. In this case, ignition angle adaptation values Z1, Z2, Z3, Z4 are used in a similar manner as the adaptation values L1, L2, L3, L4 for the air / fuel mixture ratio and analogously to the flowchart according to FIG 2 with the aid of corresponding correction values DZ1, DZ2, DZ3, DZ4 or according to 4 corrected with the help of a map or a characteristic. In this case, an enrichment of the air / fuel mixture in the case of the ignition angle correction corresponds to an ignition angle early shift and an emaciation of the air / fuel mixture corresponds to a late shift in the ignition angle. In the case of the correction of the ignition angle, the piston position of the cylinder can also be taken into account, in which the direct start is the first to be injected. Thus, it follows that the correction values DZ1, DZ2, DZ3, DZ4 for the ignition angle adaptation values Z1, Z2, Z3, Z4 are respectively determined from a two-dimensional characteristic map whose input variables are the piston position of the cylinder which is injected first in the direct start, and are representative of the corresponding combustion maximum speed. The piston position of the cylinder that is injected first in the direct start and that before the first injection based on the run-down position of the parked engine 55 is present, for the determination of the ignition timing and thus also for the correction of the same crucial to the realization of a satisfactory combustion. For the first ignition which follows the first injection and which initiates the first combustion, a first ignition angle adaptation value Z1 is in the form of an ignition delay since the end of the first injection as a function of a fuel pressure in a 1 Not shown supply line for the supply of fuel to the individual injectors 41 . 42 . 43 . 44 intended. This can thus be stored in the form of a characteristic curve in the memory and be determined at the beginning of the direct start depending on the fuel pressure from the characteristic. By contrast, the other ignition angle adaptation values Z2, Z3, Z4 can be conventional values for the ignition angle or the ignition time, without requiring an ignition delay as for the first ignition angle adaptation value Z1.

The characteristic maps or characteristic curves used can also be suitably applied in this case, for example on a test bench.

In the event that both the air / fuel mixture ratio and the ignition angle are adapted in the direct start, the corrections for these two operating variables can each be realized to a lesser extent. In this case, both the air / fuel mixture ratio and the ignition angle according to the first embodiment can after 2 be adapted. Alternatively, both the air / fuel mixture ratio and the ignition angle according to the second embodiment can after 4 be adapted. Alternatively, the air / fuel mixture ratio according to the first embodiment may 2 and the ignition angle according to the second embodiment 4 be adapted. Alternatively, the air / fuel mixture ratio according to the second embodiment may 4 and the ignition angle according to the first embodiment 2 be adapted.

By means of the method according to the invention, an immediate consideration of the fuel properties at the first start after a change in the fuel properties can be realized, for example after a refueling operation. If both the ignition angle and the air / fuel mixture ratio are adapted in the described manner during direct start, the ignition angle can be led to early, for example in the case of poorly vaporized fuel, since the combustion speed is lower and thus the increase in pressure in the combustion chamber is weaker. This Zündwinkel-early shift can be performed in parallel to enrichment, the enrichment would then be much weaker than without Zündwinkeladaption. In this way fuels can be saved.

In contrast to the starter start sets the direct combustion at the first combustion always at the engine speed zero and a specific position of the engine 55 or the crankshaft. These defined conditions allow to draw conclusions about the fuel quality from the speed curve of the first combustion. This direct inference is necessary with very different fuel qualities in order to already maximize the recovered mechanical energy from the second combustion in each case by correcting the injection parameters and / or the ignition angle, for example, sufficient to overcome a full load compression, so a compression of a full load filling , as it adjusts, for example, with open throttle and fully completed cylinder intake stroke.

Claims (12)

Method for starting an internal combustion engine ( 1 ), in particular of a vehicle, wherein an injection of fuel for the first time into a cylinder ( 5 . 10 . 15 . 20 ) of the internal combustion engine ( 1 ) and then a combustion for the first time in the cylinder ( 5 . 10 . 15 . 20 ), characterized in that a first operating variable of the internal combustion engine ( 1 ) for the first time combustion in the cylinder for the starting process ( 5 . 10 . 15 . 20 ) is evaluated and that at least one combustion variable influencing the second operating variable of the internal combustion engine ( 1 ) as a function of the evaluation for at least the subsequent combustion of the same starting process in or in at least one further cylinder ( 5 . 10 . 15 . 20 ) is adjusted. A method according to claim 1, characterized in that as a first operating variable for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 is chosen representative of the engine speed and that in the evaluation for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed is compared with a predetermined threshold. A method according to claim 2, characterized in that as the for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed is selected for the first-time combustion maximum engine speed is selected. A method according to claim 1, characterized in that as the at least one combustion-influencing operating variable of the internal combustion engine ( 1 ) a value representative of an air-fuel mixture ratio is selected. A method according to claim 2 or 3, characterized in that as the at least one combustion-influencing operating variable of the internal combustion engine ( 1 ) a value representative of an air-fuel mixture ratio is selected. A method according to claim 5, characterized in that the air / fuel mixture ratio is enriched when the for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed falls below the predetermined threshold value and that the air / fuel mixture ratio is emaciated, when the for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed exceeds the predetermined threshold. A method according to claim 5, characterized in that the air / fuel mixture ratio as a function of the combustion for the first time in the cylinder for the starting process ( 5 . 10 . 15 . 20 ) is adapted representative engine speed by means of a map. A method according to claim 1, characterized in that as the at least one combustion-influencing operating variable of the internal combustion engine ( 1 ) an ignition angle is selected. Method according to one of claims 2 to 7, characterized in that as the at least one combustion-influencing operating variable of the internal combustion engine ( 1 ) an ignition angle is selected. A method according to claim 9, characterized in that the ignition angle is shifted to early, when the for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed falls below the predetermined threshold and that the ignition angle is retarded, if the for the first time for the startup combustion in the cylinder ( 5 . 10 . 15 . 20 ) representative engine speed exceeds the predetermined threshold. A method according to claim 9, characterized in that the ignition angle as a function of the for the startup process for the first time combustion in the cylinder ( 5 . 10 . 15 . 20 ) is adapted representative engine speed by means of a map. A method according to claim 11, characterized in that the ignition angle additionally in dependence of the position of the cylinder ( 5 . 10 . 15 . 20 ) is adjusted before the first injection.

Images