METHOD FOR OPERATING A MULTI-DIRECT-INJECTION COMBUSTION ENGINE AND MASS-BASED SWITCHING OF THE NUMBER OF INJECTIONS

Description

[0001] The invention relates to a method for operating an internal combustion engine, in particular a motor vehicle, in which fuel is injected directly into a combustion chamber of the internal combustion engine in a fuel injection device in a plurality of partial injections spaced apart in time per working cycle.

[0002] Raw emissions, particularly HC and NMHC emissions and soot particle number, are very high at low engine temperatures. This can be counteracted by improving mixture formation in the combustion chamber by increasing the number of possible injections. This is especially important for cold starts and warm-up until the combustion chamber and exhaust aftertreatment system reach operating temperature.

[0003] As a general state of the art, for example, five short injection pulses per operating cycle, injected directly into a combustion chamber of the internal combustion engine, are known. Regarding exhaust aftertreatment, additional technologies are used, such as electrocatalysts in the exhaust system, burners in the exhaust system, or secondary air systems in the exhaust system for rapid catalytic converter heating. Particle storage systems, such as hydrocarbon absorbers and particulate filters, are used to reduce raw emission levels.

[0004] The publication DE 101 05 755 A1 describes a method for operating an internal combustion engine, in particular a motor vehicle, in which the fuel is injected directly into a combustion chamber of the internal combustion engine with at least one injection per working cycle, which is characterized in that a fuel injection comprises a plurality of short injection pulses spaced apart in time.

[0005] German patent application DE 10 2018 209 096 A1 describes a catalyst heating operation. An air-fuel ratio of λ ≥ 1 is used. After the charge exchange top dead center (TDC), the first injection of a fuel quantity occurs with the valve fully open, followed by a second injection with the valve only partially open. The second injection, with a second fuel quantity, occurs after the ignition TDC has been passed. Ignition then takes place at the ignition point. In this catalyst heating operation, the advantage of injection close to the ignition point can also be utilized. This can reduce raw particulate emissions and raw nitrogen oxide emissions, particularly during cold starts. Multiple injections are also possible. For example, in lean-burn operation, one or more additional injections can be performed before and after the ignition point.Similarly, in the catalytic converter heating mode, one or more fuel injections can be carried out before and after the ignition point.

[0006] The German patent application DE 10 2004 046 628 A1 discloses that when the fuel pressure in the pressure accumulator is below a threshold value, instead of a single injection, a multitude of injection pulses are provided, dividing the fuel quantity.

[0007] Further state of the art is represented by the publications DE 10 2012 000 688 A1, DE 11 2014 003 993 B4, D3 US 2003 / 233997 A1 and DE 60 2004 003 390 T2.

[0008] The invention is based on gasoline direct injection. In this process, fuel is injected at very high pressure into the combustion chamber of the internal combustion engine via injection valves located directly adjacent to the combustion chamber. The internal combustion engine operates cyclically in a known manner. In a four-stroke internal combustion engine, for example, one operating cycle comprises four power strokes. As explained above, incomplete combustion of the injected fuel leads to HC and NMHC emissions. It is known that this problem is exacerbated when the internal combustion engine is cold, as the exhaust system is still cold and therefore under particular stress.

[0009] The object of the present invention is to further develop conventional methods for direct injection of spark-ignition engines, so that fuel consumption is optimized even further, i.e., reduced, and emissions are simultaneously reduced, in order to particularly relieve the burden on the exhaust system. A further object is to reduce the amount of gasoline entering the oil of the internal combustion engine as significantly as possible.

[0010] The invention teaches a method for operating an internal combustion engine of a motor vehicle, in which fuel is injected into a fuel injection device in a

[0011] Multiple partial injections, spaced apart in time, are injected directly into a combustion chamber of the internal combustion engine per work cycle, with the following steps: Determining the total injection mass per working cycle into the combustion chamber as a function of a power requirement for the internal combustion engine, dependent on an air mass supplied to the combustion chamber, and producing a fuel / air mixture taking into account a specified air-fuel ratio; determining a maximum possible number of partial injections per working cycle as a function of a critical mass threshold of a fuel injector assigned to the respective combustion chamber, below which the fuel mass per partial injection is not undercut, and the desired total injection mass to be injected per working cycle; defining a mass-based target number of injections as a function of the determined maximum possible number of partial injections and distributing the total injection mass among the defined mass-based target number of injections;and injection of the total injection mass per working cycle according to the specified mass-based target injection number with the fuel masses divided among the partial injections.

[0012] It is further intended that, by determining the target number of injections, a switch will be made from a previously determined mass-based target number of injections to a lower maximum possible determined mass-based target number of injections due to a possible undershooting of the critical mass threshold value, which is defined as rail pressure dependent at a minimum possible opening time of the fuel injection valve.

[0013] The next step is to determine how the total injection mass is divided into the determined maximum possible smaller number of partial injections.

[0014] It is further stipulated that the determination process always involves switching from a previously determined mass-based target injection number to a maximum possible determined mass-based target injection number, taking into account the possible undershooting of the critical mass threshold value, which is reached depending on the rail pressure at a minimum possible opening time of the fuel injection valve.

[0015] Similarly, the distribution of the total injection mass across the determined maximum possible number of partial injections is then determined.

[0016] Preferably, it is provided that several partial injections are carried out in a mass-based manner within a working cycle during the intake and compression phase, wherein several partial injections, in particular up to ten partial injections, are distributed across the intake and compression phase at different injection times, particularly in two injection packages.

[0017] Furthermore, it is preferably provided that the switch to a determined lower number of partial injections is carried out in good time so that the critical mass threshold of at least one of the partial injections is not undercut, at which the distribution of the total injection mass within the determined possible number of partial injections is reliably possible.

[0018] It is also preferably provided that the switchover to a determined maximum possible number of partial injections is carried out when a mass threshold value is reached at which the distribution of the total injection mass within the determined maximum possible number of partial injections is reliably possible.

[0019] The method is preferably further characterized by the fact that switching back and forth between the critical mass threshold and the mass threshold occurs in a hysteresis.

[0020] The method is particularly advantageous in certain operating conditions. Preferably, in addition to the actual mass-based driving mode in normal operation, the method is applied in such a way that the switching of the previously determined mass-based target injection number is carried out from a stoichiometric operation of the internal combustion engine in a) a cold start (start adaptation) and / or b) a catalytic converter diagnostic (parallelization) and / or c) a catalytic converter cleaning and / or d) a component protection event, whereby there is a deviation from stoichiometric operation, so that a change in the total fuel mass delivered per operating cycle and, if necessary, in the determined mass-based target injection number is effected.

[0021] Another preferred application involves switching the previously determined mass-based target injection number when the air-fuel mixture has stabilized at a stoichiometric value and the internal combustion engine is operating in torque reserve, such as idling, catalyst heating, particulate filter regeneration, and coolant heating, whereby, depending on a decrease in the efficiency of the internal combustion engine, a switch to at least one additional partial injection takes place, thus increasing the determined mass-based target injection number.

[0022] In summary, a specific direct injection method is proposed, the "mass-based injection timing" of which is explained in detail below.

[0023] The invention is explained below with reference to the accompanying figures. These show: Figure 1: A diagram with two abscissas, wherein the first abscissa shows the injection timing (in °CA before TDC) and the second abscissa shows the crankshaft angle (in °CA) of an internal combustion engine, with a first ordinate on which the valve lift of an air intake valve assigned to a cylinder of the internal combustion engine (in mm) and a second ordinate on which the piston position of the piston arranged in the same cylinder (in mm) is plotted; Figure 2: A diagram on whose abscissa the crankshaft angle (in °CA) is plotted, wherein the wetting of a cylinder inner wall (in mg) is plotted on the ordinate; Figure 3: A diagram on whose abscissa the crankshaft angle (in °CA) is plotted, wherein the wetting of a piston surface (in mg) is plotted on the ordinate;Figure 4A shows a diagram with a characteristic map (K BPkalt ) on whose abscissa the rotational speed DRZ (in rpm) of a crankshaft is plotted, while on the ordinate the filling of a combustion chamber (in %) is plotted, wherein the characteristic map (K BPkalt ) illustrates an operating point-dependent driving style of the internal combustion engine in cold operation; Figure 4A shows a diagram with a characteristic map (K MBkalt ) on whose abscissa the rotational speed DRZ (rpm) of a crankshaft is plotted, while on the ordinate the filling of a combustion chamber (in %) is plotted, wherein the characteristic map (K MSkalt ) illustrates a driving style of the internal combustion engine in cold operation; Figure 5A shows a diagram with a characteristic map (K BPwarm) on whose abscissa the rotational speed DRZ in (1 / min) of a crankshaft is plotted, while on the ordinate the filling of a combustion chamber (in %) is plotted, whereby the characteristic map (K BPwarm) illustrates an operating point-dependent driving style of the internal combustion engine in warm operation;Figure 5: Diagram with a characteristic map (K MBwarm) on whose abscissa the rotational speed DRZ in (1 / min) of a crankshaft is plotted, while on the ordinate the filling of a combustion chamber (in %) is plotted, wherein the characteristic map (K MBwarm) illustrates a mass-based driving style of the internal combustion engine in warm operation; Figure 6A Diagrams I, II, III, IV with operating parameters (ordinate) over time t (abscissa) on a diagram of an operating point-dependent addressing of a target injection number TE n-target-BP , where in diagram I, the injected partial fuel mass m per partial injection TE n=6 and in diagram II, the speed, the relative filling of the combustion chamber, the speed of the vehicle with the internal combustion engine and the load of the vehicle (driver request, pedal) and in diagram III, the number n of partial injections TE n=6 according to the operating point-dependent target injection number TE n-target-BP and in diagram IV, the lambda value λ are shown;Figure 6B shows diagrams I, II, III, IV with operating parameters (ordinate) over time t (abscissa) on a diagram for an operating point-dependent addressing of a mass-based target injection number TE n-target-BP according to ; Figure 6Awith verification of the maximum permissible number n of partial injections TE n-max with switching of the mass-based target injection number TE n-target-MB = 6 to the mass-based target injection number TE n-target-MB = 4 due to possible undershooting of a critical mass threshold m krit , the minimum possible opening time t min of the fuel injector, wherein in diagram I, the injected fuel mass m per partial injection TE n=4 after switching from the mass-based target injection number TE n-target-MB = 6 to the mass-based target injection number TE n-target-MB = 4 and in diagram II, the engine speed, the relative filling of the combustion chamber, the speed of the vehicle with the internal combustion engine and the load of the vehicle (driver request, pedal) and in diagram III, the number n of partial injections TE n=6 and TE n=4 according to the mass-based target injection numbers and in diagram IV, the Lambda value λ are shown;Figure 7A shows a diagram of a specific fuel mass to be injected in a partial injection TE n within the operating point-dependent driving mode, a defined number n of partial injections TE n (ordinate) over time t (abscissa) with a critical mass threshold m krit undershot in the operating point-dependent driving mode due to a lack of switching, with undershooting of m krit and reaching a critical range P1 of at least one partial injection TE n ;Figure 7: Diagram of the specific fuel mass to be injected according to a continuously calculated number n of partial injections TE n (ordinate) over time t (abscissa) within mass-based driving mode, with the critical mass threshold m krit of the fuel injector in mass-based driving mode, in which the specific mass per partial injection TE n is advantageously increased automatically by switching TE n-1 of the number n of partial injections TE n without falling below m krit, and the number n is decreased, and the mass threshold m krit + m offset, at which the specific mass per partial injection TE n is automatically reduced back to the previous continuously calculated mass of the partial injections TE n, and the number n is increased again by switching TE n+1 of the partial injections TE n.

[0024] Figure 1The diagram shows two abscissas, where the first abscissa represents the injection timing (in °CA before TDC) and the second abscissa represents the crankshaft angle (CA) (in °CA) of an internal combustion engine. The first ordinate represents the valve lift (in mm) of a high-pressure fuel injector assigned to a cylinder of the internal combustion engine. The second ordinate represents the piston position (in mm) of the piston in the same cylinder.

[0025] An internal combustion engine, not shown in detail, operates according to the known four-stroke principle; one working cycle therefore comprises four strokes. It includes a combustion chamber to which air is supplied via an intake manifold, depending on the opening and closing of an intake valve according to the stroke characteristic curve KL Hub.

[0026] Fuel is injected into the combustion chamber through the fuel injector (not shown). The fuel injector is supplied from a fuel rail (not shown), which provides the fuel at very high pressure, for example, 350 bar. The fuel-air mixture formed in the combustion chamber is ignited by an ignition device (not shown), in particular a spark plug. The expansion of the burning air-fuel mixture moves a piston in a known manner, whose piston characteristic curve KL piston in Figure 1 is shown.

[0027] The operating state of the internal combustion engine, in particular the position of the piston, is detected by a sensor (not shown). The hot combustion exhaust gases are discharged in a known manner via an exhaust pipe and fed to a catalyst (also not shown) within an exhaust system (not shown).

[0028] The internal combustion engine includes a control unit, which receives information about the power demand from the user via the accelerator pedal. The control unit also receives signals from a sensor that measures the relevant angle (°KW) of the engine's crankshaft and forwards the corresponding signal to the control unit. On its output side, the control unit is also connected to, among other things, the fuel injector of an injection system and the ignition system for igniting the air-fuel mixture.

[0029] In order to achieve homogenization, that is, the most uniform possible mixing of the fuel injected into the combustion chamber by the injection valve with the air drawn in through the intake manifold, the fuel is generally injected very early, that is, at the beginning of the downward movement of the piston in the intake phase of the internal combustion engine.

[0030] At the in Figure 1 In the conventional driving mode shown, at a specific exemplary operating point BP, three partial injections TE n=3 ; TE 1 , TE 2 , TE 3 are injected in an early injection package during the intake phase according to a map setting, at predetermined crank angles °KW, at 300°KW, 275°KW and at 260°KW.

[0031] A fourth and fifth partial injection TE n=2 ; TE 4 , TE 5 , takes place in the specific exemplary operating point BP during conventional driving in a late injection package in the compression stroke at predetermined crank angles °KW at 155°KW and at 140°KW.

[0032] With a driving style of a maximum of five, which in Figure 1 The partial injections shown (TE n=5) result, for example, in a wetting of the cylinder inner wall, the so-called liner, which is shown in the characteristic curve KL Liner in Figure 2 depending on the position of the crankshaft in °KW analogous to Figure 1 is shown.

[0033] When driving with the five in Figure 1 The partial injections shown (TE n=5) result, for example, in a wetting (of the combustion chamber-side surface) of the cylinder piston, which is shown in the characteristic curve KL Zylk in Figure 3 depending on the position of the crankshaft in °KW analogous to Figure 1 is shown.

[0034] How Figure 1 As further clarified, it is provided that more partial injections TE n than before are applied during a work cycle within the intake and compression phase, whereby it is provided that at different injection times, which are specified in a characteristic map, several partial injections TE n, in the exemplary embodiment up to ten partial injections TE n=10, are distributed over the intake and compression phase.

[0035] It is intended that, according to Figure 1At the specific exemplary operating point BP, five partial injections TE n=5 ; TE 1 , TE 2 , TE 3 , TE 4 , TE 5 are initially provided, with the injection times defined in a characteristic map. It is provided that five partial injections TE 1-5 ; TE 1 , TE 2 , TE 3 , TE 4 , TE 5 are delivered at predetermined crank angles °KW between 300°KW and 260°KW during the intake phase in an early injection package, depending on the operating point. A constant pause time ΔP between the individual partial injections TE n=5, for example ΔP=1.5ms, is provided.

[0036] It is further planned that according to Figure 1At the specific exemplary operating point BP, five further partial injections TE 6-10; TE 6, TE 7, TE 8, TE 9, TE 10 are provided, with the injection times defined in a characteristic map. By way of example, it is provided that five partial injections TE 1-6; TE 1, TE 2, TE 3, TE 4, TE 5 are dispensed at predetermined crank angles KW in °KW between 155°KW and 140°KW during the compression phase in a late injection package, depending on the operating point, with a constant pause time ΔP between the individual partial injections TE 6-10, for example ΔP = 1.5 ms.

[0037] Driving style with ten in Figure 1 The partial injections shown (TE n=10) result, for example, in a wetting of the cylinder inner wall, which is shown in the characteristic curve KL Liner in Figure 2 depending on the position of the crankshaft in °KW analogous to Figure 1 is shown.

[0038] Driving style with ten in Figure 1 The partial injections shown (TE n=10) result, for example, in a wetting of the cylinder piston, which is shown in the characteristic curve KL Zylk in Figure 3 depending on the position of the crankshaft in °KW analogous to Figure 1 is shown.

[0039] Since the pressure in the combustion chamber is relatively low, especially during the intake phase, there is a risk that the fuel injected into the combustion chamber at high pressure by the fuel injector will impact the wall of the combustion chamber opposite the fuel injector or the top of the piston and adhere there. Such fuel deposits on the wall or piston are difficult to vaporize and do not participate in combustion in the combustion chamber, or at least not in the desired way, which increases fuel consumption and worsens emissions.

[0040] The problem of fuel condensation on a combustion chamber wall is – as mentioned – particularly pronounced when the combustion chamber wall is cold. In this case, the cold-start performance of the internal combustion engine is impaired in the well-known manner.

[0041] To prevent fuel from depositing on the combustion chamber wall, especially during cold operation, the fuel injector is controlled by the control unit to open and close in pulses as often as possible, meaning that as many partial injections as possible are provided to keep the fuel penetration depth in the combustion chamber so low that the fuel no longer impacts the combustion chamber wall opposite the injector.

[0042] This discontinuous fuel injection, achieved through an optimized number n of multiple n individual injection pulses or partial injections TE n into the combustion chamber, reduces the fuel penetration depth. This effectively minimizes the risk of fuel depositing on the combustion chamber wall opposite the fuel injector or on the piston surface of the cylinder piston that forms the combustion chamber. This ensures that the injected fuel is present as completely as possible as an air-fuel mixture within the combustion chamber, resulting in optimal combustion. Consequently, fuel consumption decreases and emissions are improved, particularly regarding HC, NMHC, and soot emissions.The reduced penetration depth of the fuel into the combustion chamber is particularly advantageous when the wall of the combustion chamber is cold, i.e., during a cold start of the internal combustion engine.

[0043] It becomes clear that it is highly advantageous to administer as large a number n of partial injections TE n as possible, which has been done so far as explained below.

[0044] Operating point-dependent driving mode is understood to mean that, within a map K BP, a desired number n of partial injections TE n – as a fixed operating point-dependent setting within a map K BP – is specified as a function of the engine speed DRZ and the relative filling of the combustion chamber. The total mass of fuel to be injected per working cycle depends, as is known, on the relative filling of the combustion chamber, i.e., on the mass of air entering the combustion chamber. Taking into account lambda λ=1, the total mass of fuel to be injected per working cycle is divided, as a function of the relative filling in %, into a desired number n of partial injections TE n – as a fixed operating point-dependent setting within the map K BP – either linearly or non-linearly.

[0045] The described operating-point-dependent driving style is then demonstrated using the Figure 4AThis will be further illustrated by an example of the internal combustion engine operating in cold conditions.

[0046] The Figure 4A The diagram shows a characteristic map K BPkalt, where the abscissa represents the crankshaft speed (RPM) and the ordinate represents the combustion chamber filling percentage. The K BPkalt characteristic map illustrates the operating point-dependent driving behavior of the internal combustion engine during cold operation. In other words, the K BPkalt characteristic map, or a section thereof, illustrates the operating point-dependent driving behavior of the exemplary internal combustion engine with a displacement of 1.0 l and a rated output of 85 kW (rail pressure 350 bar) during cold operation, where the number of partial injections (TE n) is specified.

[0047] In Figure 4AThe diagram of the dataed characteristic map K BPcold illustrates at which operating points BP of the aforementioned internal combustion engine in cold operation analogous to Figure 1 Ten partial injections TE 1-10 can be administered.

[0048] Within the characteristic map K BPcold, as illustrated by one of the other exemplary operating points BP with a combustion chamber filling of 75% and a DRZ of 2500 in 1 / min (pressure in rail 350 bar), eight partial injections TE n=8 are specified depending on the operating point.

[0049] In other words, the map setting at the exemplary cold operating point 75% / 2500 rpm results in only eight partial injections TE n=8 being carried out, which according to Figure 1 The work cycle is distributed into early and late packages in a preferred configuration.

[0050] This means that this map specification, in an exemplary alternative operating point BP of the map K BPcolt, which differs from the number of partial injections TE n=10, only shows eight partial injections TE n=8 at the operating point with a fill level of 75% and an engine speed of 2500 rpm. This is because, at this operating point BP, the maximum desired number of ten partial injections TE n-max = 10 cannot be achieved, due to the total injection mass mges intended for injection, which depends on the operating point, using ten partial injections TE n=10, taking into account a minimum possible opening time tmin of the fuel injector, which cannot be undercut, and a predetermined constant pause time ΔP, as will be explained further below.

[0051] For a fuel injector, the minimum possible, i.e., available, opening time t min of the fuel injector is t min = t oe + t as + ts . This time t min cannot be reduced.

[0052] Here, t min is the minimum opening time of the switching valve, t oe is the opening time, t as is the time at the stroke stop, and ts is the closing time.

[0053] The longer the time t min, the more mass (fuel mass) is taken from the switching chamber of the fuel injector and the greater the fuel injection mass of the fuel injector (injector) which is injected into the combustion chamber by adjusting an injector needle controlled by the switching valve through the fluid pressure in the switching chamber.

[0054] This also means that the minimum possible opening time t min of the fuel injector, taking the rail pressure into account, is assigned a critical mass threshold m krit, which cannot be undercut in the sense of a specific critical mass m krit per partial injection TE n. In other words, an injection mass smaller than m krit per partial injection TE n cannot be implemented by the fuel injector.

[0055] Each fuel injector has a known injector specification, meaning that, without considering operationally relevant influences (such as aging, etc.), t min, the minimum opening time t min of the fuel injector, and the associated injector-specific critical mass threshold m krit are known.

[0056] According to the invention, the procedure is as follows: With the aim of realizing the greatest possible number of partial injections TE n-max in every operating mode (cold or warm operation) of the internal combustion engine, but especially in cold operation, it is provided according to the invention to determine the maximum possible number of partial injections TE n-max as a function of the minimum opening time t min of the fuel injection valve, taking into account the total fuel mass m Ges to be injected and taking into account that in certain operating conditions the critical mass threshold m krit of the fuel injection valve is not undercut.

[0057] Using the previous approach based exclusively on operating point-dependent characteristic maps K BPkalt (compare Figure 4A ) or K BPwarm (compare Figure 5A) this highest possible number n-max of partial injections TE n-max is not optimally solved, since the dataing of the characteristic maps with regard to the number of partial injections TE n is decided exclusively on the basis of the relative filling and the speed DRZ in the respective operating point BP and the associated specific total injection mass m Ges and is fixed by dataing the respective characteristic map K BP.

[0058] In other words, lambda setpoint jumps, where deviations from stoichiometric operation λ=1 occur due to operating states such as a) cold start (start adaptation), b) catalytic converter diagnostics (parallelization), c) catalytic converter removal, or d) component protection events, and a change in the total fuel mass mges delivered per work cycle is caused, are disadvantageously not taken into account in the operating point-dependent approach with regard to the maximum possible number n of partial injections TEn-max.

[0059] A further problem arises with the operating-point-dependent approach, which the invention aims to solve. The problem is that if the total fuel mass mges to be injected per operating cycle changes, while the number n of partial injections TEn and the pause times ΔP between partial injections TEn remain constant, there is a risk that a critical condition will arise within the operating-point-dependent map due to lambda jumps. This is caused by the fuel injector injecting too low a fuel mass per partial injection at a specific number n of partial injections TEn in the operating-point-dependent map, due to its minimum possible opening time tmin. This occurs when the total fuel mass mges per operating cycle is reduced by a certain amount, for example, in lean-burn or other operating conditions.

[0060] In other words, for example, with an operating point-dependent addressing of the target injection number TE n-target-BP in the operating point-dependently dataed characteristic map, six partial injections TE n=6 (compare beforehand) Figure 6A If the injection quantity (n=6) is not changed due to a reduced total fuel mass (mges) of the fuel, the critical mass threshold (mcrit) of the fuel injector may be undershot. This is because, considering the minimum possible opening time (tmin) of the fuel injector, the reduced total fuel mass (mges) is completely dispensed after, for example, five partial injections (TEn=5). This means that at least one of the six partial injections (TEn=6) cannot be dispensed, thus preventing the [missing information] associated with [missing information]. Figure 1The fuel distribution described above did not occur as desired, and therefore was detrimental.

[0061] As already mentioned, the internal combustion engine includes a control and regulating unit to which the power requirement of a user is communicated via a fuel pedal, so that an operating point-dependent fuel mass is transmitted to the control and regulating unit.

[0062] If, depending on the respective operating point BP, the fuel mass increases or decreases in the described operating conditions, the total injection mass mges changes accordingly. A calculation of the total injection mass mBP that depends solely on the operating point does not take into account the changes in the total injection mass mges caused by the aforementioned operating conditions.

[0063] For this reason, the invention provides that in the control and regulating device to which the power request is transmitted, no operating point-dependent total injection masses m BP are transmitted, but only mass-based total injection masses m Ges are calculated and determined, as explained below.

[0064] Depending on the performance requirements, mass-based driving mode means that a specific total injection mass mges is desired or specified for each operating cycle. Depending on the air mass supplied to the combustion chamber, the specified total injection mass mges is added, taking into account a specified lambda value λ of the supplied air mass. It is designed that, even before the actual injection, the maximum number n of partial injections TEn – depending on mcrit and the desired total injection mass mges – is always determined "automatically" and "continuously" per operating cycle.The total injection mass mges is then always injected in the maximum possible number n of partial injections TEn-max, whereby the total injection mass mges is distributed linearly or non-linearly among the partial injections TEn, taking into account that the critical mass threshold mcrit is not undercut. The aim is to never fall below the critical mass threshold mcrit, considering the rail pressure.

[0065] For example, a specific power requirement at an operating point BP is determined in cold operation using the mass-based characteristic map K MBcold according to Figure 4B A total mass mges is assigned to be injected. This assignment allows, for example, a "cold start adaptation" to be carried out, so that, deviating from the operating point-dependent driving style, an increased total injection mass mges is injected within the cold start adaptation.

[0066] This specification is transmitted via the control unit and advantageously taken into account by the mass-based approach by increasing the total injection mass mges and then proceeding as previously explained.

[0067] This means that, in mass-based driving mode, the specific total injection mass mges – now the one increased by cold-start adaptation – is specified for each operating cycle based on the increased total injection mass mges resulting from the power demand and cold-start adaptation. Depending on the air mass supplied to the combustion chamber, this cold-start-induced increased total injection mass mges is added, taking into account a predefined lambda value λ of the supplied air mass. It is designed that, even before the actual injection, the maximum number n of partial injections TEn – depending on mcrit and the desired cold-start-induced increased total injection mass mges to be injected – is always determined "automatically" and "continuously".Subsequently, the total injection mass mGes is always injected in the maximum possible number n of partial injections TEn-max, whereby the total injection mass mGes is distributed linearly or non-linearly among the partial injections TEn, also taking into account that mcrit is not undercut, on a mass-based basis.

[0068] In each operating cycle, a value is available for the maximum total opening time ΔtGes of the fuel injector for injecting the total injection mass mGes in the n partial injections TEn, assuming the total injection mass mGes would be dispensed in a single injection n=1. This total opening time ΔtGes is, according to the previously explained premises, divided into a maximum possible number n of partial injections TEn-max with multiple partial opening times, taking into account that mcrit is not undercut, mass-based, so that the mass-based target injection number TEn-target-MB is available in the control unit and is ultimately executed as the actual injection number TEn-actual-MB.

[0069] The procedure is such that the respective (current) total injection mass mGes is divided into equal (linear) or unequal (non-linear) fuel masses m per partial injection TEn, taking into account constant or variable predefinable pause times ΔP and the critical mass threshold mcrit, whereby the maximum possible number n of partial injections TEn-max is calculated, which is then available in the control unit as the determined mass-based target injection number TEn-target-MB and is finally executed as the actual injection number TEn-actual-MB.

[0070] The advantage is provided by Figure 4B clarifies. By comparing the in Figure 4B Mass-based determination of the maximum possible number of partial injections TE n-max = 9 at the operating point 75% / 2500 rpm with the same operating point 75% / 2500 rpm in Figure 4AIt becomes clear that the total injection mass mges, depending on the minimum opening time tmin of the injection valve known from the injector specification and the predefinable uniformly distributed pause times ΔP of equal length between the individual partial injections TEn, can be up to nine TEn-max = 9 by the mass-based calculation, instead of previously (compare Figure 4A ) eight partial injections TE n=8 can be carried out, which are specified in the conventional operating point-dependent procedure in the characteristic map K BPcold.

[0071] By increasing the number of partial injections, here in the exemplary embodiment n+1, the already explained desired advantages with regard to the optimal combustion of the injected fuel and with regard to the reduction of fuel consumption and the improvement of emission behavior, in particular the HC, NmHC and soot emissions, especially in cold operation (cold start) of the internal combustion engine are achieved.

[0072] This approach is also supported by the Figure 5A and 5B clarifies.

[0073] The Figure 5A The diagram shows a characteristic map K BPwarm on whose abscissa the rotational speed DRZ in 1 / min of a crankshaft KW is plotted, while on the ordinate the relative filling of a combustion chamber in % is plotted, whereby the characteristic map K BPwarm illustrates an operating point-dependent driving style of the internal combustion engine in warm operation.

[0074] The Figure 5BThe diagram shows a characteristic map K MBwarm on whose abscissa the rotational speed DRZ in 1 / min of a crankshaft KW is plotted, while on the ordinate the filling of a combustion chamber in % is plotted, whereby the characteristic map K MBwarm illustrates a mass-based driving style and calculation of the maximum possible number of partial injections TE n-max of the internal combustion engine in warm operation.

[0075] According to the Figure 5A and 5BA special feature is highlighted, namely that in mass-based driving with the aim of determining the largest possible number of partial injections TE n, a threshold value is taken into account, where TE n-max < / =3) sein soll. Das heißt, hinsichtlich der maximalen Anzahl TE n-max der Teileinspritzungen wird im warmen Betrieb, wie zuvor erläutert, die jeweilige (aktuelle) Gesamteinspritzmasse m Ges in gleichgroße eingespritzte Kraftstoffmassen m pro Teileinspritzungen TE n unter Berücksichtigung der gleichbleibenden vorgebbaren Pausenzeit ΔP und des kritischen Massenschwellenwertes m krit geteilt, wodurch die maximal mögliche Anzahl n von Teileinspritzungen TE n-max errechnet wird. Ist der errechnete Wert TE n-max > 3, the number of partial injections TE n is set to the maximum value n=3.

[0076] This means that in warm operation, according to the mass-based characteristic map K MBwarm, only determined mass-based target injection numbers TE n-target-MB =1, 2 or 3 are processed in the control and regulating unit and are set off as partial injections TE n as actual injection numbers TE n-actual-MB.

[0077] The advantage of the mass-based approach is due to Figure 5B clarifies. By comparing the in Figure 5B Mass-based determination of the maximum possible number of partial injections TE n-max = 2 at the operating point 75% / 2500 rpm with the same operating point 75% / 2500 rpm in Figure 5A It becomes clear that the total injection mass mges, depending on the minimum opening time tmin of the injection valve known from the injector specification and the predefinable uniformly distributed pause times ΔP of equal length between the individual partial injections TEn, can be up to two TEn-max = 2 by the mass-based calculation, instead of previously (compare Figure 5A ) only partial injections TE n=1 can be carried out, which are specified in the conventional operating point-dependent procedure in the characteristic map K BPcold.

[0078] Mass-based driving thus advantageously allows for the consideration of not only performance-related parameters, such as the desired torque, but also operating conditions during combustion engine operation, such as the removal of the catalytic converter from the exhaust system. In this case, the fuel mass is increased independently of the user's power demand by pressing the accelerator pedal. This increases the total fuel mass to be injected in the respective operating cycle, i.e., the total injection mass mges, which is determined by mass-based driving in the KNBcold maps (see...). Figure 4B ) and K MBwarm (compare Figure 5B ) is taken into account.

[0079] Mass-based driving makes it advantageously possible to adjust the total injected mass mges in the respective map KMBcold (compare) regardless of whether the engine is cold or warm, using the example load-dependent operating point 75% / 2500 rpm. Figure 4B ) or K MBwarm (compare Figure 5B ) can be driven richer - with more fuel - or leaner - with less fuel.

[0080] In this determination, it is always taken into account whether the maximum possible number TE n-max of partial injections TE n, determined as a function of the total injection mass m Ges defined in the characteristic map K MBkalt or in the characteristic map KMBwarm, can also be realized within a maximum total time Δt Ges available for injection.

[0081] The Figure 6ADiagrams I, II, III, IV show operating parameters (ordinate) over time t (abscissa) on a diagram of an operating point-dependent addressing of a determined target injection number TE n-target-BP .

[0082] Diagram I shows the injected mass m per partial injection for six partial injections TE n=6.

[0083] Diagram II shows the characteristic curves: rotational speed with associated scaling, the relative filling of the combustion chamber with associated scaling, the vehicle speed without associated scaling (constant > 0), and the driver's request (pedal = constant >0), also without scaling.

[0084] Diagram III shows the number n of partial injections TE n=6 according to the operating point-dependent target injection number TE n-target-BP =6.

[0085] Diagram IV shows the lambda value λ, which forms the basis for the characteristic curves shown in diagrams I to III.

[0086] The vertical line A in the figure illustrates that in lean operation λ > 1 according to diagram IV with unchanged operating point-dependent target injection number TE n-target-BP = 6 according to diagram III and constant driving style of the internal combustion engine according to diagram II, the injected fuel mass m per partial injection TE n, at the specified target injection number TE n-target-BP = 6, may adversely reach the critical mass threshold ?m krit of the fuel injection valve, as illustrated at the intersection of line A at the lowest value of the mass m per partial injection TE n in diagram I.

[0087] In this case, the total mass mGes to be injected is so small due to the lambda jump to λ > 1, which illustrates the invention, that the corresponding fuel mass can no longer be safely deposited within six partial injections TEn=6 because of tmin, the minimum possible opening time tmin of the fuel injection valve.

[0088] This problem is solved by the inventive method, as explained below.

[0089] Figure 6B Diagrams I, II, III, IV with operating parameters (ordinate) versus time t (abscissa) are shown in one figure, with an operating point-dependent addressing of a target injection number TE n-target-BP according to Figure 6Awith verification of the maximum permissible number n of partial injections TE n with switching from the determined mass-based target injection number TE n-target-MB =6 to the mass-based determined target injection number TE n-target-MB =4 due to possible undershooting of the critical mass threshold m krit , which is reached by the minimum possible opening time t min of the fuel injection valve.

[0090] Diagram I shows the injected fuel mass m per partial injection TE n=4 after switching from the determined mass-based target injection number TE n-target-MB =6 to the determined mass-based target injection number TE n-target-MB =4.

[0091] Diagram II shows the characteristic curves: rotational speed with associated scaling, the relative filling of the combustion chamber with associated scaling, the vehicle speed without associated scaling (constant > 0), and the driver's request (pedal = constant <0), also without scaling.

[0092] Diagram III shows the number n of partial injections TE n=6 and TE n=4 according to the mass-based target injection numbers TE n-target-MB =6 and determined mass-based target injection number TE n-target-MB =4.

[0093] Diagram IV shows the lambda value λ, which forms the basis for the characteristic curves shown in diagrams I to III.

[0094] The vertical line B in the figure illustrates that in lean operation λ > 1 according to diagram IV according to diagram III, a switch is made from the mass-based determined target injection number TE n-target-MB =6 to the determined target injection number TE n-target-MB =4.

[0095] Diagram II clearly shows that the constant driving style of the internal combustion engine corresponds to Diagram II, meaning that the load specified by the driver has not changed.

[0096] Since the injected fuel mass m per partial injection TE n, at the specified target injection number TE n-target-BP = 6, adversely approaches the critical mass threshold μcrit of the fuel injector according to Diagram I, the number n of partial injections TE n is reduced to the mass-based target injection number TE n-target-MB = 4. Compare Diagram III at the intersection with line B.

[0097] This increases the injected fuel mass m per partial injection TE n as desired at TE n-target-MB =4, as illustrated in diagram I at the intersection with line B, so that the risk of a possible undershooting of m crit , depending on the minimum possible opening time t min of the fuel injector no longer exists.

[0098] In the exemplary embodiment, due to the large amount of the lambda step chosen for clarification, the determined mass-based target injection number TE n-target-MB = 6 is reduced to TE n-target-MB = 4 by the number n-2.

[0099] The principle applies that in the control unit n-1 or n+1, according to the above calculation of the possible mass-based target injection number TE n-target-MB, switching operations are carried out to adjust the determined mass-based target injection number TE n-target-MB based on the mass-based target injection number TE n-target-MB. In the exemplary embodiment, the reduction of the determined mass-based target injection number TE n-target-MB = 6 to TE n-target-MB = 4 was thus carried out in the control unit in quick succession by two switching operations n-1. This staged switching is in Figure 6B not discernible.

[0100] The Figure 7A Finally, a diagram shows the injected fuel mass m of a partial injection TE n (ordinate) over the time t (abscissa) of a multiple injection with a critical mass threshold m crit of the fuel injector in the operating point-dependent driving style.

[0101] Furthermore, in Figure 7A to clarify the invention in relation to Figure 7B A mass threshold value mcrit + moffset is represented, at which the injection of the specified masses of all partial injections TE n of a multiple injection is definitely possible in the operating point-dependent and mass-based driving modes.

[0102] In the case of multiple injections in one work cycle, for example, with six partial injections TE n=6, it is analogous to Figure 6AIt is possible that at least one partial injection TE n, when addressing the target injection number TE n-target-BP = 6 according to arrow P1, will enter a critical range P1 below mcrit if no change in the target injection number TE n-target-BP = 6 occurs due to the mass of fuel delivered during six partial injections TE n = 6. The critical mass threshold mcrit of the fuel injector will be undershot, with the effect that at least one of the partial injections TE n = 6 will not be triggered or will not be triggered reliably.

[0103] According to legend L1 in Figure 7A No switching of TE n-target-BP occurs at the critical mass m crit, which is detrimental.

[0104] According to the invention, the situation is different, as in Figure 7B is shown.

[0105] This diagram again shows the injected fuel mass m per partial injection TE n (ordinate) over time t (abscissa) with the critical mass threshold m crit of the fuel injector in mass-based driving mode.

[0106] Furthermore, in Figure 7B analogous to Figure 7A The mass threshold mcrit + moffset is represented, at which the mass-based specified masses of all partial injections TEn of a multiple injection remain non-critical after a switch to a higher number n of partial injections TEn, as will be explained further below.

[0107] In the case of multiple injections in one work cycle, for example, with six partial injections TE n=6, it is analogous to Figure 6B It is no longer possible that at least one partial injection TE n, when addressing the target injection number T=6 according to the arrow P1, enters a critical area P1 below m krit.

[0108] Advantageously, the mass-based target injection number TE n-target-MB = 6 is changed before the critical range P1 is undershot, i.e., the mass-based target injection number TE n-target-MB = 6 is reduced in the exemplary embodiment (compare Figure 6 , in particular I and III, line B) twice by n-1 to TE n-target-BP = 4. This means that the critical mass threshold mcrit of the fuel injector is no longer undershot, with the effect that all of the partial injections are always recorded as the actual injection number TE n-actual-MB = 4. If the critical mass threshold mcrit is reached within a hysteresis period, the mass-based target injection number TE n-target-MB is reduced.

[0109] If the mass threshold value mcrit + moffset is reached again within the hysteresis between mcrit and mcrit + moffset, the mass-based target injection number TEn - target MB = 4 in the exemplary embodiment according to the invention (compare Figure 6 , in particular I and III) twice by n+1 to TE n-target-MB =6 and dropped as actual injection number TE n-actual-MB =6.

[0110] The hysteresis advantageously ensures that switching between the threshold values ​​m crit +m offset and m crit is possible without causing a permanent switching between the respective number n of partial injections TE n=6.

[0111] According to legend L2 in Figure 7B A switchover occurs at m krit +m offset to TE n-target-MB if at least one further injection n+1 is possible without the critical mass m krit being undercut.

[0112] According to legend L3 in Figure 7BA switchover from at least one partial injection TE n to n-1 of TE n-target-MB takes place before the critical mass m crit is reached.

[0113] The legend L4 in the Figures 7A and 7B denotes the critical mass mcrit below which the opening of the injection valve is not reliably guaranteed.

[0114] Finally, here are some examples of the aforementioned specific operating conditions, in which, in particular, lambda setpoint jumps occur.

[0115] Starting from the stoichiometric operation λ=1, in these operating states a) cold start (start adaptation), b) catalytic converter diagnostics (parallelization) or c) catalytic converter removal or d) component protection events, deviations from the stoichiometric operation λ=1 occur, resulting in a change in the total fuel mass mges delivered per work cycle.

[0116] These operating conditions are taken into account using the inventive method, the "mass-based driving mode", as follows. a) Cold start (start adaptation):

[0117] For example, as already explained, the additional fuel mass required during start-up adaptation is achieved by means of an additional partial injection TE n+1 (additional partial injection) after testing of the switchover, in order to positively influence the homogenization of the air-fuel mixture and thus protect the internal combustion engine even better from fuel entering the oil. b) Catalyst diagnosis (parallelization):

[0118] If the load-dependent operating point BP does not change, and the total injection quantity mGes is increased or decreased for other reasons in an operating condition such as the CAT diagnostics of the exhaust system, where the fuel quantity is changed independently of the user's power requirement, this operating condition "CAT diagnostics" has so far been disadvantageously disregarded with regard to the maximum possible number n of partial injections TEn-max.

[0119] It is preferably intended that during catalytic converter diagnosis, in the case of a lean mixture adjustment (compare Figure 6B , I to IV) of the air-fuel mixture and simultaneously maintaining the operating point in the quasi-steady state, a switching takes place advantageously taking into account the critical mass m krit, so that instead of n partial injections TE n at least one partial injection TE n-1 less is carried out.

[0120] In case of fat adjustment (compare Figure 6B , I to V) of the air-fuel mixture, however, at the same quasi-stationary operating point, an increased total injection quantity mges is required, which takes place by switching, taking into account the critical mass mcrit, so that instead of n partial injections TEn, at least one additional partial injection TEn+1 is carried out. c) Catalytic removal:

[0121] Even when the catalytic converter is removed, the air-fuel mixture is enriched. It is intended that, advantageously, at least one additional partial injection (TE n+1) takes place, taking the switchover into account. d) Component protection events:

[0122] For component protection reasons, the air-fuel mixture is also enriched. Similar to the process of removing the catalytic converter, this enrichment advantageously leads to at least one additional partial injection (TE n+1), taking into account the switching process. Momentary reserve:

[0123] Finally, as a further embodiment, it is provided that - even if the air-fuel mixture has stabilized at a lambda value, but the internal combustion engine is operated in the torque reserve, such as idling, catalytic converter heating, particulate filter regeneration and coolant heating, the mass-based driving mode or its switching is advantageously used depending on the efficiency deterioration of the engine by switching to at least one additional partial injection TE n+1.

[0124] The present invention also relates to a computer program suitable for carrying out the above method when executed on a computer. It is particularly preferred that the computer program be stored in memory. The present invention also relates to the aforementioned control and / or regulating device for operating an internal combustion engine, in particular a motor vehicle, in which the fuel is injected directly into a combustion chamber of the internal combustion engine. In order to optimize the operation of the internal combustion engine with regard to fuel consumption and emissions, it is proposed according to the invention that the control and / or regulating device be suitable for and used to control and / or regulate the above method. It is particularly preferred that the control and / or regulating devices are each provided with a computer program of the type mentioned above.The invention relates to an internal combustion engine with at least one combustion chamber and a device that injects the fuel directly into the combustion chamber. To improve the operating characteristics of this internal combustion engine, in particular fuel consumption, emissions, and cold-start performance, the invention provides that the internal combustion engine is equipped with a control and / or regulating device. Reference symbol list

[0125] Crankshaft (CW) °CW degrees Crankshaft angle (CW) Cylinder piston top dead center at ignition DRZ Engine speed (RPM) n Number of partial injections or nth injection n-1 Number-reducing switchover n+1 Number-increasing switchover TE n partial injections TE n-max Number of maximum possible partial injections TE n TE n-target-BP Target injection number (operating point dependent) TE n-target-MB Target injection number (mass-based) K BP cold map operating point dependent in cold operation K MB cold map mass-based in cold operation K BP warm map operating point dependent in warm operation K MB warm map mass-based in warm operation KL Stroke Intake valve characteristic KL Piston Piston characteristic KL Liner characteristic Cylinder inner wall wetting KL Cylk characteristic Cylinder piston wetting ΔP Intermittent time t min Minimum opening time t oe Opening time t as Time at stroke stop ts Closing time mFuel mass m Total injection mass (mass-based) mBP Total injection mass (operating point-dependent) mcrit criticalMass threshold? mcrit Is the critical mass threshold not reached? moffset Amount of an injection mass as an offset of the critical mass threshold mcrit + moffset Mass threshold P1 Arrow, critical range λ Lambda A Line A B Line B L1 Figure text L2 Figure text L3 Figure text L4 Figure text

Claims

1. Method for operating an internal combustion engine of a motor vehicle, in which fuel in a fuel injection device is injected directly into a combustion chamber of the internal combustion engine in a plurality (n) of time-spaced partial injections (TEn) per duty cycle, the method comprising the following steps: determining the total injection mass (mGes) per duty cycle into the combustion chamber as a function of an output requirement for the internal combustion engine as a function of an air mass supplied into the combustion chamber; and producing a fuel / air mixture, taking into account a predetermined air-fuel ratio, further comprising the following steps: identifying a maximum possible number (n) of partial injections (TEn-max) per duty cycle as a function of a critical mass threshold (mkrit) of a fuel injector assigned to the particular combustion chamber, in which the fuel mass per partial injection (TEn) is not undercut, and of the desired determined total injection mass (mGes) per duty cycle to be injected, determining a mass-based target injection number (TEn-Soll-MB) as a function of the identified maximum possible number (n) of partial injections (TEn-max) and distribution of the total injection mass (mGes) to the determined mass-based target injection number (TEn-Soll-MB), and injecting the total injection mass (mGes) per duty cycle according to the determined mass-based target injection number (TEn-Soll-MB) with the fuel masses (m) distributed to the partial injections (TEn), wherein the previously identified mass-based target injection number (TEn-Soll-MB) is switched to a lower maximum possible identified mass-based target injection number (TEn-Soll-MB) due to a possible undercutting of the critical mass threshold (mkrit), which is defined dependent on rail pressure at a minimum possible opening time (tmin) of the fuel injector, and a distribution of the total injection mass (mGes) to the identified maximum possible lower number (n-1) of partial injections (TEn-max) is determined, wherein the previously identified mass-based target injection number (TEn-Soll-MB) is always switched to a maximum possible identified mass-based target injection number (TEn-Soll-MB) taking into account the possible undercutting of the critical mass threshold (mkrit), which is reached dependent on rail pressure at a minimum possible opening time (tmin) of the fuel injector, and a distribution of the total injection mass (mGes) to the identified maximum possible number (n+1) of partial injections (TEn-max) is determined.

2. Method according to claim 1, characterized in that in a duty cycle within the intake and compression phase, a plurality of partial injections (TEn) are delivered on a mass basis, wherein at different injection times, a plurality of partial injections (TEn), in particular up to ten partial injections (TEn=10), are distributed in particular in two injection bundles to the intake and compression phase.

3. Method according to claim 1, characterized in that an identified lower number (n) of partial injections (TEn-Soll-MB) is switched to before the critical mass threshold (mkrit) of at least one of the partial injections (TEn) is undercut in which the distribution of the total injection mass (mGes) within the determined possible number (n) of partial injections (TEn) is possible.

4. Method according to claim 1, characterized in that an identified maximum possible number (n) of partial injections (TEn-max) is switched to when a mass threshold (mkrit+mOffset) is reached in which the distribution of the total injection mass (mGes) within the determined maximum possible number (n) of partial injections (TEn-max) is possible.

5. Method according to claims 3 and 4, characterized in that a switching back and forth in a hysteresis takes place between the critical mass threshold (mkrit) and the mass threshold (mkrit+mOffset).

6. Method according to claim 1, characterized in that the previously identified mass-based target injection number (TEn-Soll-MB) is switched, starting from a stoichiometric operation (λ=1) of the internal combustion engine, in certain operating states such as an a) cold start (start adaptation) and / or a b) catalytic converter diagnosis (parallelization) and / or a c) catalytic converter purging and / or a d) component protection event, wherein the stoichiometric operation (λ=1) is deviated from so that a change in the total fuel mass (mGes) put through per duty cycle and, if required, in the identified mass-based target injection number (TEn-Soll-MB) is achieved.

7. Method according to claim 1, characterized in that the previously identified mass-based target injection number (TEn-Soll-MB) is switched when the air-fuel mixture has stabilized to a stoichiometric value, and the internal combustion engine is operated in the torque reserve, such as idling, catalytic converter heating, particulate filter regeneration, and coolant heating, wherein, depending on a deterioration in the efficiency of the internal combustion engine, at least one additional partial injection (TEn+1) is switched to, so that the identified mass-based target injection number (TEn-Soll-MB) is increased.

8. Computer program, characterized in that it is configured to carry out the method according to any of claims 1 to 7 when executed on a computer, wherein the computer program is stored in a memory.

9. Control and / or regulation apparatus for operating an internal combustion engine of a motor vehicle, in which the fuel is injected directly into a combustion chamber of the internal combustion engine, characterized in that the apparatus is configured to control and / or regulate the method according to any of claims 1 to 7, wherein the control and regulation apparatus is provided with a computer program according to claim 8.

10. Internal combustion engine comprising at least one combustion chamber and a fuel injection device which injects the fuel directly into the combustion chamber, characterized in that the internal combustion engine is provided with a control and / or regulation apparatus according to claim 9.