Method for operating a multiple direct injection internal combustion engine and number of injections based on mass switching
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- VOLKSWAGEN AG
- Filing Date
- 2023-03-22
- Publication Date
- 2026-06-02
Smart Images
Figure CN116804397B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for operating an internal combustion engine, particularly a motor vehicle, wherein fuel is directly injected into the combustion chamber of the internal combustion engine in partial injections at intervals between each other in a device for fuel injection during each working cycle. Background Technology
[0002] In particular, the raw emission levels of HC emissions, NMHC emissions, and particulate matter are very high at lower engine temperatures. This can be countered by improving the mixture formation in the combustion chamber, i.e., increasing the number of injections possible. This is especially necessary for cold starts and warm-up until the combustion chamber and exhaust aftertreatment are at operating temperatures.
[0003] As is commonly known in existing technologies, five short injection pulses, spaced five times apart from each other, are injected directly into the combustion chamber of an internal combustion engine per working cycle. Additional technologies are used for exhaust aftertreatment, such as electrocatalytic converters in the exhaust system, burners in the exhaust system, or secondary air systems in the exhaust system for rapid heating of the catalyst. To reduce raw emission levels, particulate storage systems, such as HC absorbers and particulate filters, are used.
[0004] Printed document DE 101 05 755A1 describes a method for operating an internal combustion engine, particularly a motor vehicle, wherein fuel is directly injected into the combustion chamber of the internal combustion engine at least once per working cycle, characterized in that the fuel injection comprises multiple short injection pulses spaced apart from each other.
[0005] Printed document DE 10 2018 209 096 A1 describes a catalyst-heated operation for a catalyst. Here, an air ratio of λ ≥ 1 is selected. After the load change top dead center, a first injection of the first fuel quantity is achieved with the closed element fully open, followed immediately by a second injection with the closed element only partially open. The second injection is achieved with a second fuel quantity after exceeding the ignition top dead center. Ignition is then achieved at the ignition timing. Here, the advantage of near-ignition injection can also be utilized in catalyst-heated operation. Therefore, particulate emissions and nitrogen oxide emissions can be reduced, especially during cold starts. Multiple injections are also possible. Therefore, one or more additional injections can be performed during lean-burn operation before and after ignition timing. Similarly, one or more fuel injections can be performed during catalyst-heated operation before and after ignition timing.
[0006] Printed document DE 10 2004 046 628 A1 discloses that, when the fuel pressure in the accumulator is below a threshold, the fuel quantity is set with multiple injection pulses as an alternative to the single injection in the case of divided fuel quantity. Summary of the Invention
[0007] The starting point of this invention is gasoline direct injection. In this method, fuel is injected at very high pressure into the combustion chamber of an internal combustion engine via an injection valve directly located in the combustion chamber. Here, the internal combustion engine operates in a known cyclic manner. In the case of a four-stroke internal combustion engine, the working cycle includes, for example, four working strokes. As explained above, incomplete combustion of the injected fuel results in HC emissions and NMHC emissions. It is known that this problem is amplified in the cold state of the internal combustion engine, where the exhaust system is still cold and under particular load.
[0008] The objective of this invention is to improve conventional methods for direct injection in gasoline engines, thereby further optimizing fuel consumption, i.e., reducing it, and simultaneously reducing emissions, in particular to alleviate the load on exhaust systems. Furthermore, this objective is to significantly reduce the load on the gasoline input to the internal combustion engine.
[0009] Therefore, the starting point of the present invention is a method for operating an internal combustion engine, particularly a motor vehicle, wherein fuel is directly injected into the combustion chamber of the internal combustion engine in partial injections at multiple time intervals in each working cycle in a device for fuel injection, comprising the following steps:
[0010] The total injection mass into the combustion chamber for each working cycle depends on the power requirements of the internal combustion engine, which in turn depends on the determination of the mass of air supplied to the combustion chamber and the manufacture of the fuel / air mixture taking into account a pre-given air-fuel ratio.
[0011] The maximum possible number of partial injections per work cycle depends on the verification of the fuel injection valve associated with the corresponding combustion chamber, in which the fuel mass injected in each partial injection is not less than a critical mass threshold and the determined total fuel mass to be injected in each work cycle.
[0012] The mass-based rated number of injections depends on the determination of the verified maximum possible number of partial injections and the allocation of total fuel mass to the determined mass-based rated number of injections; and
[0013] The total fuel mass for each work cycle is determined based on the number of injections, with the fuel mass allocated to the partial injections.
[0014] Preferably, the setup is configured such that a quality-based switch is made by verifying that the critical quality threshold defined in the case of the fuel injection valve opening time, which depends on the rail pressure, is lower than the previously verified rated number of injections to a smaller maximum possible empirically verified number of injections.
[0015] The next step is to determine the division of total fuel mass into the maximum possible number of partial injections.
[0016] Preferably, the following additional setting is made: by verifying that the critical mass threshold, which depends on the rail pressure at the minimum possible opening time of the fuel injection valve, is lower than the previously verified rated number of injections, the mass-based switching between the maximum possible empirically proven number of injections is always performed.
[0017] Similarly, the next step is to determine the division of total fuel mass into the verified maximum possible number of partial injections.
[0018] Another preferred configuration is to place multiple partial injections based on mass during the working cycle within the intake and compression phases, wherein multiple partial injections at different injection times, particularly up to ten partial injections, are divided into intake and compression phases, especially in the two injection groups.
[0019] Furthermore, it is preferable to configure the process such that quality-based switching to a fewer number of verified partial sprays is performed in a timely manner, so that at least one critical quality threshold in the partial sprays is not lowered, wherein the division of the total spray quality within the number of verified possible partial sprays is reliably possible.
[0020] Furthermore, it is preferable to configure the process such that quality-based switching is performed on the portion of the verified maximum possible number of injections, where the division of the total injection quality within the portion of the verified maximum possible number of injections is reliably possible when a quality threshold is reached.
[0021] The method is further preferably characterized by switching back and forth between the critical quality threshold and the quality threshold in a hysteresis state.
[0022] This method is particularly advantageous under defined operating conditions. Preferably, the method is applied in normal operation, in addition to actual mass-based operation, such that the switching of previously verified rated injection counts is initiated by stoichiometric operation of the internal combustion engine during a) cold start (start-up adaptation) and / or b) catalyst diagnostics (parallel) and / or c) catalyst cleaning and / or d) component protection events, wherein the stoichiometric operation is deviated from, thereby causing a change in the total fuel mass traversed per duty cycle and, if necessary, the verified rated injection counts.
[0023] Another preferred application is achieved in that the previously verified rated number of injections is switched when the air-fuel mixture is stably at the stoichiometric ratio and the internal combustion engine is running in torque reserve, such as idling, catalyst heating, particulate filter regeneration and coolant heating, wherein the verified rated number of injections is increased by switching to at least one additional partial injection depending on the efficiency degradation of the internal combustion engine.
[0024] A specific method for direct injection is proposed in general, and its "mass-based injection time" is described in detail below. Attached Figure Description
[0025] The present invention will be described below with reference to the accompanying drawings. Wherein:
[0026] Figure 1 A graph with two horizontal axes is displayed, where the injection timing (in °KW before ZOT) is plotted on the first horizontal axis and the crankshaft angle of the internal combustion engine (in °KW) is plotted on the second horizontal axis. The horizontal axis is associated with a first vertical axis plotted on the valve travel (in mm) of the intake valve of the cylinder of the internal combustion engine and a second vertical axis plotted on the piston position (in mm) of the piston arranged in the same cylinder.
[0027] Figure 2 A graph showing crank angles (in °KW) plotted on the horizontal axis and cylinder wall wetting (in mg) plotted on the vertical axis is displayed.
[0028] Figure 3 A graph showing crankshaft angles (in °KW) plotted on the horizontal axis and piston surface wettability (in mg) plotted on the vertical axis is displayed.
[0029] Figure 4A Displays characteristic curves (K) BPkalt The graph shows the crankshaft speed DRZ (in 1 / min) on the horizontal axis and the combustion chamber filling (in %) on the vertical axis. The characteristic curve (K...) BPkalt This illustrates the operating mode of an internal combustion engine during cold operation, which depends on the operating point.
[0030] Figure 4B Displays characteristic curves (K) MBkalt The graph shows the crankshaft speed DRZ (in 1 / min) on the horizontal axis and the combustion chamber filling (in %) on the vertical axis. The characteristic curve (K...) MBkaltThis describes the operating mode of an internal combustion engine during cold operation;
[0031] Figure 5A Displays characteristic curves (K) BPwarm The graph shows the crankshaft speed DRZ (in 1 / min) on the horizontal axis and the combustion chamber filling (in %) on the vertical axis. The characteristic curve (K...) BPwarm This illustrates the operating mode of an internal combustion engine during hot operation, which depends on the operating point.
[0032] Figure 5B Displays characteristic curves (K) MBwarm The graph shows the crankshaft speed DRZ (in 1 / min) on the horizontal axis and the combustion chamber filling (in %) on the vertical axis. The characteristic curve (K...) MBwarm This describes the mass-based operating mode of an internal combustion engine during hot operation;
[0033] Figure 6A The display shows the number of injections TE at the rated number of injections. n-Soll-BP The graphs I, II, III, and IV are plots on the image that depend on the addressing of the run point, with run parameters (vertical axis) versus time t (horizontal axis).
[0034] • In Figure I, the TE for each partial injection is shown. n＝6 The mass of the injected fuel is m, and
[0035] • Figure II shows the engine speed, relative filling of the combustion chamber, speed of the vehicle with the internal combustion engine, and vehicle load (driver expectation, pedal position), and
[0036] • In Figure III, the partial injection TE is shown based on the rated number of injections depending on the operating point. n＝6 The number of times n, and
[0037] • The value of λ is shown in Figure IV;
[0038] Figure 6B Shown in accordance with Figure 6A Rated number of injections TE n-Soll-BP The graphs I, II, III, and IV, showing the operating parameters (vertical axis) versus time t (horizontal axis) in the case of addressing dependent on the run point, with partial injection TEs showing the maximum allowed number of injections n. n-max Inspection, with rated number of sprays TE n-Soll-MB =6 to the rated number of sprays based on quality (TE) n-Soll-MB =4 due to the critical mass threshold m kritThe possible lower than the minimum possible opening time t of the fuel injection valve min Quality-based switching, in which,
[0039] • In Chart I, the number of injections TE at the rated number of injections is shown. n-Soll-MB =6 to rated number of sprays TE n-Soll-MB =4 after quality-based switching, each partial injection TE n＝4 The mass of the injected fuel, and
[0040] • Figure II shows the speed, relative filling of the combustion chamber, speed, and vehicle load (driver expectation, pedal) of a vehicle with an internal combustion engine, and
[0041] • In Figure III, the partial injection TE is shown based on the rated number of injections per mass. n＝6 and TE n＝4 The number of times n, and
[0042] • The value of λ is shown in Figure IV;
[0043] Figure 7A The partial injection TE is shown as the number of times n is determined within the operating mode depending on the operating point. n Partial injection TE within (vertical axis) n A graph showing the determined mass of fuel to be injected versus time t (x-axis), with the critical mass threshold m that falls below the threshold due to lack of switching in operating modes that depend on the operating point. krit , with m krit The lower than and at least once partial injection TE n The critical range P1 is reached;
[0044] Figure 7B The partial injection TE is displayed based on the number of times n is continuously calculated within the quality-based operation mode. n A graph of the determined mass of fuel to be injected (vertical axis) versus time t (horizontal axis), representing the critical mass threshold m in mass-based operation with a fuel injection valve. krit In which TE is sprayed in partial spray each time n The determined quality is advantageously achieved through n partial injections of TE. n Quality-based switching TE n-1 At no less than m krit In the case where the number of iterations n is automatically increased and the number of iterations n is decreased, and a quality threshold m is included. krit +m Offset In which TE is sprayed in partial spray each time n The determined quality was automatically reduced to a partial injection TE nThe previously calculated mass, and the number of times n is injected via partial TE. n Quality-based switching TE n+1 It was raised again. Detailed Implementation
[0045] Figure 1 A graph with two horizontal axes is displayed. The first horizontal axis plots the injection timing of the internal combustion engine (in °KW before ZOT), and the second horizontal axis plots the crankshaft angle of the internal combustion engine (in °KW). The first vertical axis plots the valve travel (Ventilhub, sometimes also called valve lift or valve stroke) of the high-pressure fuel injection valve associated with the internal combustion engine cylinder (in mm). The second vertical axis plots the piston position (in mm) of the piston located in the same cylinder.
[0046] The internal combustion engine, not shown in further detail, operates in a known manner according to the four-stroke principle, and its working cycle therefore comprises four strokes. It includes a combustion chamber, which, via an intake manifold, depends on the opening and closing of intake valves according to the stroke characteristic curve KL. Hub Supply air.
[0047] Fuel is injected into the combustion chamber through a fuel injection valve (not shown in more detail). The fuel injection valve supplies fuel from a fuel collection pipe (not shown), also referred to as a "track," in which fuel is supplied at very high pressures, such as 350 bar. Ignition of the fuel-air mixture formed in the combustion chamber is achieved by an ignition device (not shown in more detail), particularly a spark plug. The piston is moved in a known manner by the expansion of the burning air-fuel mixture. Figure 1 The figure shows its piston characteristic curve KL. Kolben .
[0048] The operating status of the internal combustion engine, particularly the piston position, is obtained by sensors not shown in further detail. Hot combustion exhaust gases are discharged via an exhaust pipe in a known manner and directed to a catalytic converter, also not shown, in an exhaust system (not shown).
[0049] The internal combustion engine includes a control and regulation unit, to which the user's power demand is transmitted via the accelerator pedal. Furthermore, the control and regulation unit receives signals from sensors that acquire the crankshaft angle (°KW) of the internal combustion engine and send corresponding signals to the control and regulation unit. Additionally, on the output side, the control and regulation unit is connected to the injection valves of the injection system and the ignition device for igniting the air-fuel mixture.
[0050] In order to achieve homogenization, that is, to mix the fuel injected into the combustion chamber by the injection valve as evenly as possible with the air drawn in through the intake manifold, the fuel is usually injected very early, that is, at the beginning of the piston's downward movement during the intake phase of the internal combustion engine.
[0051] exist Figure 1 In the case of the conventional operation shown, TE is partially injected three times at a defined exemplary operating point BP. n＝3 TE1, TE2, and TE3 are injected during the intake phase in the earlier injection group, according to the numerical markings (Kennfeldbedatung) of the characteristic curves performed, in the case of a pre-given crankshaft angle °KW, in the case of 300°KW, 275°KW, and in the case of 260°KW.
[0052] Fourth and fifth part injection TE n＝2 ;TE4,TE5 are performed at the defined exemplary operating point BP in the case of normal operation, in the later injection group, in the compression stroke, in the case of a pre-given crankshaft angle °KW, in the case of 155°KW, and in the case of 140°KW.
[0053] With the maximum of five, in Figure 1 The part of the jet TE shown n＝5 In operating conditions, for example, the wetting (Benetzung) of the cylinder inner wall (so-called bushing) is obtained, which in Figure 2 Characteristic curves KL Liner The value depends on the crankshaft position and is expressed in °KW, similar to... Figure 1 To show.
[0054] With five times Figure 1 Partial spray TE shown n＝5 In the case of operation, for example, the wetting of the cylinder piston (the surface on the combustion chamber side) is determined, which in Figure 3 Characteristic curves KL Zylk The value depends on the crankshaft position and is expressed in °KW, similar to... Figure 1 To show.
[0055] like Figure 1 Further, as shown, the following settings are made: during the intake and compression phases of the working cycle, more partial injection TEs are placed compared to the current configuration. n The following settings are made: different injection times are marked on the characteristic curve, with more of the injection TE portion being used. n In this embodiment, up to ten partial TE injections n＝10 It is divided into the intake and compression stages.
[0056] Make the following settings here, according to Figure 1 In the defined exemplary operating point BP, five partial injection TEs are initially set. n＝5 TE1, TE2, TE3, TE4, TE5, where the injection timing is numerically marked on the characteristic curve. The following settings are made: five partial injections TE... 1-5 TE1, TE2, TE3, TE4, and TE5, in the case of a pre-given crankshaft angle °KW, in the intake phase, in the earlier injection group, according to the invention, depending on the operating point being placed between 300°KW and 260°KW, wherein TE1, TE2, TE3, TE4, and TE5 are provided with TE5 injections in each partial injection phase. n＝5 The same (constant) stopping time ΔP between them, for example ΔP = 1.5ms.
[0057] Further settings are made as follows, namely, according to Figure 1 Five additional partial injections TE are set at the defined exemplary operating point BP. 6-10 ;TE6,TE7,TE8,TE9,TE 10 The injection timing is numerically marked on the characteristic curve. An example setting is as follows: five partial injections TE... 1-6 TE1, TE2, TE3, TE4, and TE5, under a pre-defined crankshaft angle (in °KW), are positioned between 155°KW and 140°KW in the later injection group during the compression phase, depending on the operating point. Furthermore, TE5 is configured to be used in each partial injection stage. 6-10 The same (constant) stopping time ΔP between them, for example ΔP = 1.5ms.
[0058] With ten times Figure 1 The part of the jet TE shown n＝10 In operating conditions, for example, the wetting of the cylinder inner wall is obtained, which is in Figure 2 Characteristic curves KL Liner The value depends on the crankshaft position and is expressed in °KW, similar to... Figure 1 It is shown.
[0059] With ten times Figure 1 The part of the jet TE shown n＝10 In operating conditions, for example, the wetting of the cylinder piston is determined. Figure 3 Characteristic curves KL Zylk The value depends on the crankshaft position and is expressed in °KW, similar to... Figure 1 It is shown.
[0060] Because of the relatively low pressure in the combustion chamber, especially during the intake phase, there is a risk that fuel injected into the combustion chamber at higher pressure by the fuel injection valve may impact and adhere to the combustion chamber wall or the top surface of the piston opposite the fuel injection valve. This fuel coating on the wall or piston is difficult to evaporate and does not, or at least does not participate in combustion in the desired manner, increasing fuel consumption and worsening emissions behavior.
[0061] The problem of fuel deposition on the combustion chamber walls is particularly prominent, as mentioned, when the combustion chamber walls are cold. In this case, the cold start behavior of the internal combustion engine is affected in a known manner.
[0062] To avoid fuel deposition on the combustion chamber walls, especially during cold operation, the fuel injection valve is configured such that it is operated by a control and regulation device to open and close in a pulsed manner as frequently as possible; that is, it is equipped with as many partial injection TEs as possible. n-max This is to keep the fuel penetration depth in the combustion chamber so low that the fuel no longer impacts the wall of the combustion chamber opposite the injection valve.
[0063] Fuel is injected via multiple individual injection pulses or partial injections of TE, optimized for n times. n The discontinuous fuel injection into the combustion chamber reduces the fuel penetration depth. This effectively reduces the risk of fuel deposition on the combustion chamber wall opposite the fuel injection valve or on the piston surface of the cylinder piston that forms the combustion chamber. This ensures that the fuel injected into the combustion chamber is present as completely as possible as an air-fuel mixture within the combustion chamber, thus achieving optimal combustion of the injected fuel. This reduces fuel consumption and improves emission behavior, particularly HC, NMHC, and particulate emissions. The reduced fuel penetration depth is particularly advantageous when the combustion chamber walls are cold, i.e., during a cold start of an internal combustion engine.
[0064] The following becomes clear: that is, to place the partial spray TE as many times as possible, n times. n It is very advantageous, and it is currently being carried out as explained below.
[0065] The operating mode, which depends on the operating point, can be understood as follows: On characteristic curve K... BP The specific parameters depend on the engine speed (DRZ) and the relative filling of the combustion chamber, as well as the partial injection (TE). n The expected number of times n (as shown on the characteristic curve K) BPThe numerical markings (fixed within one or more default values depending on the operating point) are described. The total mass of fuel to be injected per working cycle depends in a known manner on the relative fill of the combustion chamber, that is, on the mass of air reaching the combustion chamber. The total mass of fuel to be injected per working cycle, considering the case of λ=1, depends on the relative fill (in percentage) and is linearly or non-linearly divided into fractional injections TE of the desired number of times n. n (as shown in characteristic curve K) BP (The fixed numerical markers within the value depend on one or more default values depending on the running point).
[0066] The described operation mode, which depends on the running point, is then used with the help of Figure 4A For example, it is explained in more detail in the cold operation of internal combustion engines.
[0067] Figure 4A The characteristic curve K is shown in the graph. BPkalt The crankshaft speed DRZ (in 1 / min) was plotted on the horizontal axis, while the combustion chamber filling (in %) was plotted on the vertical axis. The characteristic curve K... BPkalt This illustrates the operating mode of an internal combustion engine during cold operation, depending on the operating point. In other words, the characteristic curve K... BPkalt Alternatively, the characteristic curves may illustrate the operating conditions at a specific operating point for an exemplary internal combustion engine selected during cold operation with a displacement of 1.0L and a nominal power of 85kW (at a pressure of 350bar in the rail), in which TE is partially injected. n The number of times is marked with a number.
[0068] exist Figure 4A In the middle, the characteristic curve K of the marked numbers is used as a reference. BPkalt The chart illustrates the similarities between the operating points BP of the internal combustion engine during cold operation. Figure 1 Can be placed for ten partial sprays TE 1-10 .
[0069] In the characteristic curve K BPkalt Internally, as shown in other exemplary cases with 75% combustion chamber filling and a DRZ of 2500 (in units of 1 / min) at the run point BP (pressure of 350 bar in the rail), eight partial injection TE n＝8 It depends on the run point being given in advance.
[0070] In other words, the default characteristic curve of 75 (%) / 2500 (1 / min) at the exemplary cold operating point results in the following: only eight partial injection TE n＝8 It was carried out, based on Figure 1In the work cycle, the preferred design scheme is divided into earlier and later groups.
[0071] This means that in the characteristic curve K BPkalt Partially injected TE n＝10 Another exemplary operating point where the number of deviations is observed is the characteristic curve at the default value in the operating point BP, where fill = 75% and speed DRZ = 2500 (in 1 / min), with only eight partial injection TEs. n＝8 This is because, in the case of the operating point BP, for example, the maximum expected number of partial injections TE is ten. n-max =10 Due to the setting of the total injection mass m depending on the operating point for injection. Ges With the help of ten partial injections TE n＝10 Considering the minimum possible opening time t of the fuel injection valve min = (which cannot be lower than) and the case of maintaining the same stopping time ΔP given in advance cannot be realized, as further explained.
[0072] In the case of fuel injection valves, the minimum possible, or rather, usable, opening time t of the fuel injection valve. min derive t min =t oe +t as +t s At that time t min It cannot be lower than.
[0073] Here, t min It is the minimum opening time of the switching valve, t oe It's the opening time, t as The time at the end of the journey (Hubanschlag) and t s That is the closing time.
[0074] Time t min The longer the fuel injection valve, the more mass (fuel mass) is extracted from the control chamber (Schaltraum) of the fuel injection valve and injected into the combustion chamber by the injector needle controlled by the control valve through the fluid pressure in the control chamber.
[0075] Similarly, this means the minimum possible opening time t of the fuel injection valve. min When considering orbital pressure, this relates to the critical mass threshold m. krit It sprays TE in each partial injection n The determined critical mass m krit In its meaning, it cannot be lower than. In other words, each partial injection TE n Compared to mkrit Smaller injection mass cannot be achieved through fuel injection valves.
[0076] Each fuel injection valve here has a known injector specification, meaning that, without considering operational-related effects (such as aging), t min Minimum opening time t of fuel injection valve min and the specific critical mass threshold m of the subordinate injector krit It is known.
[0077] According to the present invention, it is carried out as follows:
[0078] To achieve the maximum possible number of TE cycles in any operating mode of the internal combustion engine (cold or hot operation), but especially in cold operation. n-max Partial injection TE n To achieve this objective, according to the present invention, the following setting is made: the setting depends on the minimum opening time t of the fuel injection valve. min Considering the total fuel mass to be injected, m Ges Determine the maximum possible number of partial injections TE under the following circumstances. n-max Furthermore, consider the following: under a given operating condition, the critical mass threshold m of the fuel injection valve... krit Not lower than.
[0079] With the help of the current characteristic curve K based on the number of markers that depends only on the running point BPkalt (see Figure 4A ) or K BPwarm (see Figure 5A The action method is to maximize the number of n-max partial injections TE. n-max The problem was not optimally solved because, given the partial injection TE... n The labeled numbers of the characteristic curves for the number of injections are based solely on relative filling and rotational speed DRZ at the corresponding operating point BP, and the associated determined total injection mass m. Ges To determine and through the corresponding characteristic curve K BP The marked numbers are fixed and given in advance.
[0080] In other words, the total fuel mass m traversed in each working cycle is deviated from the operating state a) cold start (start-up adaptation), b) catalyst diagnostics (parallel), c) catalyst cleaning, or d) component protection event, starting from stoichiometric operation λ=1. Ges The variation of λ-rated jump, in the case of action depending on the running point, with respect to the maximum possible number of partial jet TEs n. n-max Not to be affected in an adverse way.
[0081] Another problem arises in situations where the action depends on the operating point, which should be solved by the present invention. This problem lies in the following: the total fuel mass to be injected in each working cycle, m... Ges In the case of changes, and while maintaining the same number of injections n, TE is sprayed. n and in part of the injection TE n In the case of a constant stopping time ΔP, there is a danger due to λ jumps that a critical state is formed within the characteristic curve, which depends on the marked number of the operating point. This is caused by the fuel injection valve exceeding its minimum possible opening time t. min TE is injected in a portion of the characteristic curve that depends on the operating point, at a certain number of times. n In cases where the partial injection injects too low a fuel mass each time, when the total fuel mass m in each working cycle... Ges For example, when a definite value decreases in a rarefied operating state (Magerbetriebszustand) or other operating states.
[0082] In other words, for example, at the rated number of injections TE n-Soll-BP In the case of addressing dependent on the operating point, a characteristic curve that depends on the operating point marker number is set with, for example, a six-part injection TE. n＝6 (see Figure 6A Then it is possible that, when the total fuel mass m to be traversed decreases due to the reduction in fuel, the following is true. Ges Without achieving a change in the number of injections n=6, the critical mass threshold m of the fuel injection valve is generated. krit The lower the value. This is due to the following, namely, the reduced total fuel mass m to be traversed. Ges Considering the minimum possible opening time t of the fuel injection valve min In cases such as five partial injections of TE n＝5 It has since completely stopped. This means that the following occurred: six partial injections of TE. n＝6 At least once in the process of not being or not being able to be stopped, thus relating to Figure 1 The associated fuel distribution was not achieved in an adverse manner as expected.
[0083] As already mentioned, an internal combustion engine includes a control and regulation device, to which the user's power demand is communicated via the fuel pedal, and thus the fuel quality at the operating point is transmitted to the control and regulation device.
[0084] If the fuel mass increases or decreases depending on the corresponding operating point BP in the described operating conditions, the total injection mass to be observed is m. Ges Changes. Total injection mass m BPThe number of marks depends only on the operating point and does not consider the total injection mass m due to changes in the mentioned operating conditions. Ges .
[0085] For this reason, the present invention is configured such that the total injection mass m, which depends on the operating point, is not transmitted in the control and regulation device to which the power demand is transmitted. BP Instead, it only calculates and determines the total mass of the jet based on mass. Ges As explained below.
[0086] Based on power requirements, the mass-based operation mode can be understood as follows: for each work cycle, the expected or pre-given total injection mass m is... Ges The total injection mass m is determined based on the mass of air supplied to the combustion chamber. Ges It is added considering a pre-given value λ of the supplied air quality, wherein the following settings are made: the partial injection TE is always verified "automatically" and "continuously" even before actual injection, and the number of times n is injected per work cycle. n Depends on m krit and the desired total fuel mass m to be injected Ges That is the maximum possible. Next, the total ejected mass m Ges The spray always occurs in portions of TE with the maximum possible number of sprays n. n-max The process is underway, including partial injection of TE. n Total spray mass m Ges Linear or nonlinear when considering not less than m krit In the case where the mass is divided into sub-spray TE n Above. The objective is to ensure that, considering orbital pressure, the mass does not fall below the critical mass threshold m. krit .
[0087] The power requirements determined at the operating point BP, for example, in cold operation, are based on mass. Figure 4B Characteristic curve K MBkalt The total mass m to be sprayed is related to the total mass m. Ges This association allows for, for example, "cold start adaptation," thereby increasing the total injection mass m within the cold start adaptation by deviating from the operating mode depending on the operating point. Ges .
[0088] This default value is transmitted via the control and regulation device and is taken into account in an advantageous manner through a mass-based action, namely, the total injection mass m Ges It is raised and then proceeded as previously explained.
[0089] This means that, based on the increased total injection mass m resulting from power demand and cold start adaptation... Ges In a quality-based operation, for each work cycle, a predetermined total injection mass m is provided, which is increased by cold start adaptation at this time. Ges Depending on the quality of air supplied to the combustion chamber, this cold start causes an increase in the total injection mass m. Ges It is added considering a pre-given value λ of the supplied air quality, wherein the following settings are made: even before actual injection, the partial injection TE is always verified "automatically" and "continuously" a certain number of times n is injected per work cycle. n Depends on m krit The expected cold start before injection results in an increase in total fuel mass m Ges That is the maximum possible. Next, the total ejected mass m Ges The spray always occurs in portions of TE with the maximum possible number of sprays n. n-max The process is underway, including partial injection of TE. n Total spray mass m Ges Linear or nonlinear, the same applies when considering m. krit In the case where the mass is divided into sub-spray TE n superior.
[0090] Here, the maximum available total opening time Δt for the fuel injection valve in each work cycle is given. Ges The value for m is available for use with respect to the total injection mass. Ges In nth partial injection TE n In the injection, when the total injection mass m Ges When it is released in the only jet n=1, the total opening time Δt Ges Based on the previously stated premise, considering a minimum of m krit In the case where the mass is divided into the maximum possible number n of partial injection TEs with multiple partial opening times, the injection TEs are based on the mass. n-max Thus, the rated number of injections TE exists in the control and regulation device. n-Soll-MB And ultimately implemented as the actual number of sprays TE n-Ist-MB .
[0091] This is done in such a way that the corresponding (current) total injection mass m Ges Considering a fixed or variable, pre-given stopping time ΔP and a critical mass threshold m krit In this case, it is divided into TE injections for each partial injection. n Given fuel masses m of the same (linear) or different (non-linear) size, the maximum possible number of partial injections TE is n. n-maxIt is calculated that this is then used in the control and regulation device as the verified rated number of injections TE n-Soll-MB The number of sprays (TE) exists and is ultimately implemented. n-Ist-MB .
[0092] Advantages through Figure 4B To display. By comparison in Figure 4B In the operation point 75 (%) / 2500 (1 / min), the maximum possible number of partial injections TE based on the mass is determined. n-max =9 and in Figure 4A The same operating point 75 (%) / 2500 (1 / min) becomes clear as follows, that is, the total spray mass m to be sprayed. Ges The minimum opening time t depends on the injector valve and is known from the injector manual. min And the equal length of the TE spray in each sub-section can be given in advance with an average distribution. n The stopping time ΔP between these points can be determined based on mass up to nine TEs. n-max =9 is calculated as currently (see Figure 4A Eight partial injections TE n＝8 The alternative is to perform it in the characteristic curve K in the conventional operation mode that depends on the running point. BPkalt The middle part is given in advance.
[0093] By increasing the number of partial injections, here in embodiment n+1, especially in the cold operation (cold start) of the internal combustion engine, the advantages described are achieved due to the optimal combustion of the injected fuel and due to the reduction in fuel consumption and the improvement in emission behavior, especially HC emissions, NmHC emissions and soot emissions.
[0094] This method of action also... Figure 5A and 5B To display.
[0095] Figure 5A Displaying characteristic curve K BPwarm The graph plots crankshaft power (kW) at speed DRZ (in 1 / min) on the horizontal axis and combustion chamber relative filling (in %) on the vertical axis. The characteristic curve K... BPwarm It shows the operating mode of an internal combustion engine during hot operation, which depends on the operating point.
[0096] Figure 5B Displaying characteristic curve K MBwarm The graph plots crankshaft power (kW) at speed DRZ (in 1 / min) on the horizontal axis and combustion chamber relative filling (in %) on the vertical axis. The characteristic curve K... MBwarmShows the calculation of the partial injection TE based on the quality-based operating mode and the maximum possible number of times in the hot-running internal combustion engine. n-max of the calculation.
[0097] According to Figure 5A and 5B illustrates a characteristic, which lies in the fact that in the case of the quality-based operating mode, the threshold default value is considered for the purpose of determining the maximum possible number of times TE n-max of the partial injection TE n in which TE n-max should be < / = 3). That is to say, in view of the maximum number of times TE n-max of the partial injection in the hot run, as previously described, the same pre-given stop time ΔP and the critical mass threshold m krit are considered, and the partial injection is divided into the same-sized injected fuel mass m for each partial injection TE n , and thus the maximum possible number n of partial injections TE n-max is calculated. If the calculated value TE n-max > 3, the number of partial injection times TE n is set to the maximum value n = 3.
[0098] That is to say, in the control and regulation device, in the hot run, only the verified rated injection times TE MBwarm = 1, 2 or 3 are processed according to the quality-based characteristic curve K n-Soll-MB and are set as the actual injection times TE n . n-Ist-MB .
[0099] The advantages of the quality-based mode of action are shown by Figure 5B . By comparing the maximum possible number of partial injections TE Figure 5B determined based on quality at the operating point 75 (%) / 2500 (1 / min) in n-max = 2 with Figure 5A at the same operating point 75 (%) / 2500 (1 / min) in Ges , it becomes clear that the total injection mass m min to be injected depends on the minimum opening time t n of the injection valve known from the injector specification and the pre-given equally distributed and equal-length stop time ΔP between each partial injection TE n-max = 2 can be carried out as an alternative to the current (see Figure 5A ) single partial injection TE n＝1 , which in the conventional operating mode depending on the operating point in the characteristic curve K BPkaltThe middle part is given in advance.
[0100] By employing a quality-based operating method, it is therefore possible, advantageously, that not only performance-related parameters, such as desired torque, are considered, but also operating conditions, such as catalyst cleaning of the exhaust system, arise during the operation of the internal combustion engine, where fuel quality is increased regardless of the user's power demand via throttle pedal operation. Consequently, the desired total fuel mass to be injected in the corresponding operating cycle is increased, that is, the total injection mass m Ges It operates based on a quality-based method in the characteristic curve K. MBkalt (see Figure 4B ) and K MBwarm (see Figure 5B It was considered in the ( ).
[0101] In an advantageous manner, mass-based operation is possible, i.e., independent of cold or hot conditions, exemplarily depending on the load, at an operating point of 75 (%) / 2500 (L / min) via the total sprayed mass m. Ges The load-independent matching is shown in the corresponding characteristic curve K. MBkalt (see Figure 4B ) or K MBwarm (see Figure 5B It can be driven in a richer (with more fuel) or leaner (with less fuel) state.
[0102] Here, in this determined case, it is always considered whether it depends on the characteristic curve K. MBkalt Or characteristic curve K MBwarm The total spray mass m to be sprayed is determined in the middle. Ges The maximum possible number TE is determined n-max Partial injection TE n The maximum total time available for injection Δt Ges The same can be achieved internally.
[0103] Figure 6A This shows the number of verified rated injections (TE). n-Soll-BP The graphs I, II, III, and IV are based on the addressing of the run point and show the run parameters (vertical axis) with respect to time t (horizontal axis).
[0104] Chart I shows the TE in six partial injections. n＝6 In the case of partial spraying, the mass m of the sprayed component is [missing information].
[0105] Figure II shows the speed characteristic curves with an attached scale, the relative filling of the combustion chamber with an attached scale, and the vehicle speed (constant > 0) without an attached scale, as well as the driver expectation (pedal = constant > 0) without a scale.
[0106] Figure III shows the number of rated injections (TE) depending on the operating point. n-Soll-BP =6 partial injection TE n＝6 The number of times n.
[0107] The value λ is shown in Figure IV, which forms the basis for the characteristic curves shown in Figures I through III.
[0108] The vertical line A in the image is shown below, that is, in the thin run (Magerbetrieb) λ>1 according to Chart IV, the constant nominal number of injections TE depending on the run point according to Chart III. n-Soll-BP =6 and in the case of constant operation of the internal combustion engine according to Chart II, each partial injection of TE n The mass of fuel injected, m, at a predetermined number of injections, TE. n-Soll-BP =6. If necessary, in an unfavorable manner, is the fuel injection valve at its critical mass threshold? m krit In the middle, such as at the intersection of line A, in each partial injection of TE n The case of the minimum value of mass m is shown in Figure I.
[0109] In this case, the total mass m to be sprayed Ges Because the λ jump to λ>1 described in this invention is so small, that is, the associated fuel mass is in the six partial injection TE n＝6 Internal due to t min (Minimum possible opening time t of the fuel injection valve) min It can no longer be reliably placed.
[0110] This problem is eliminated by means of action according to the invention, as described below.
[0111] Figure 6B Graphs I, II, III, and IV, showing operating parameters (vertical axis) versus time t (horizontal axis), illustrate the time t at the rated number of injections TE. n-Soll-BP In the case where the addressing depends on the run point, according to Figure 6A Partial injection TE with maximum allowed number of times n n The test, with verified rated number of sprays TE n-Soll-MB =6 to the rated number of sprays based on quality-based empirical verification TE n-Soll-MB=4 on mass-based switching, due to the minimum possible opening time t of the fuel injection valve min The critical quality threshold m that is reached krit The probability is lower than that.
[0112] Chart I shows the verified rated number of injections TE n-Soll-MB =6 to verified rated number of sprays TE n-Soll-MB =4 after quality-based switching, each partial injection TE n＝4 The mass of fuel injected, m.
[0113] Figure II shows the characteristic curves for engine speed with an auxiliary scale, relative filling of the combustion chamber with an auxiliary scale, vehicle speed without an auxiliary scale (constant > 0), and driver expectation (pedal = constant < 0) without an auxiliary scale.
[0114] Figure III shows the number of rated injections (TE) based on mass (n rated injections). n-Soll-MB =6 and verified rated number of sprays TE n-Soll-MB =4) Partial injection TE n＝6 and TE n＝4 The number of times n.
[0115] The value λ is shown in Figure IV, which forms the basis for the characteristic curves shown in Figures I through III.
[0116] The vertical line B in the image is shown below, that is, in the thin operation λ>1 according to Chart IV, the empirically proven number of injections TE based on quality is achieved according to Chart III. n-Soll-MB =6 to verified rated number of sprays TE n-Soll-MB Switching on =4.
[0117] As becomes clear in Figure II, the constant operating mode of the internal combustion engine is consistent with Figure II, which means that the load given in advance by the driver does not change.
[0118] Because each partial injection TE n The mass of fuel injected, m, at a predetermined number of injections, TE. n-Soll-BP In the case of =6, what is the disadvantageous aspect of the critical mass threshold of the fuel injection valve according to Chart I? krit Therefore, part of the TE injection was obtained. n The number of times n is reduced to the rated number of injections TE n-Soll-MB =4. See Figure III at the intersection with line B.
[0119] Therefore, to improve in TE in the desired way n-Soll-MBIn the case of 4, TE is partially injected each time. n The mass of fuel injected, m, as shown in Figure I at the intersection with line B, thus depends on the minimum possible opening time t of the fuel injection valve. min Possibly lower than m krit The risk no longer exists.
[0120] In this embodiment, because the larger value of λ jump is selected for display, the verified rated number of injections TE n-Soll-MB =6 was reduced to TE by n-2 times. n-Soll-MB =4.
[0121] The following principle applies: in the control and regulation device, n-1 or n+1 is based on the possible quality-verified rated number of injections TE. n-Soll-MB The above calculations are performed for the verified rated number of injections TE n-Soll-MB The switching is based on quality matching. In this embodiment, the verified rated number of injections TE is therefore executed briefly and sequentially through two brief, sequentially implemented switching steps n-1 in the control and regulation device. n-Soll-MB =6 to TE n-Soll-MB =4. This quality-based switching of the classification is at... Figure 6B It cannot be identified.
[0122] final, Figure 7A This shows the critical mass threshold m with fuel injection valve in an operating mode that depends on the operating point. krit With partial injection TE n A graph showing the mass of the sprayed material (vertical axis) versus the time t between multiple sprays (horizontal axis).
[0123] In addition, Figure 7A For reference Figure 7B This invention illustrates a quality threshold m. krit +m Offset TE sprayed in all parts of the sprayed multiple times n The injection of a pre-given mass is reliably possible in any operation that depends on the operating point and is based on mass.
[0124] In cases of multiple injections during a work cycle, such as in a situation similar to... Figure 6A Six partial injections TE n＝6 It is possible in the case that at least one partial injection of TE is performed. n At the rated number of sprays TE n-Soll-BP =6 depends on the addressing of the run point, according to arrow P1 at m kritIn the critical range P1 below, when the mass of fuel being passed through during the sixth partial injection TE... n＝6 In cases where the rated number of sprays (TE) is not achieved n-Soll-BP When the value changes by 6, the critical mass threshold m of the fuel injection valve... krit Being lower than, has the following effect, namely, partial injection TE n＝6 At least once, it is not set or is not reliably set.
[0125] According to Figure 7A In the diagram L1, the critical mass m is not achieved in an unfavorable manner. krit TE in the case n-Soll-BP Switching.
[0126] According to the present invention and in Figure 7B The different representations shown are illustrated.
[0127] The chart also shows the TE for each partial injection. n The injected fuel mass m (ordinate) versus time t (horizontal axis), and the critical mass threshold m with fuel injection valve in mass-based operation. krit .
[0128] In addition, Figure 7B Similar to Figure 7A The quality threshold m is shown. krit +m Offset TE sprayed in all parts of the sprayed multiple times n The mass based on a pre-given mass is used in the partial injection of TE up to n times. n After the switch, it remains non-critical, as further explained below.
[0129] In the case of multiple injections during a work cycle, for example, in a situation similar to... Figure 6B Six partial injections TE n＝6 In situations where at least one partial TE injection is no longer possible, n At the rated number of sprays TE n-Soll-MB In the case of quality-based addressing with a value of 6, according to arrow P1 at m... krit Within the critical range P1 below.
[0130] Thus, the rated number of injections TE is achieved advantageously before falling below the critical range P1. n-Soll-MB =6, which means the rated number of injections TE n-Soll-MB =6 In this embodiment (see Figure 6, especially I and III, line B), n-1 to TE are used twice. n-Soll-BP =4 is a decrease. This means that the critical mass threshold m of the fuel injection valve... kritNo longer being lower than, with the following effect: all of the partial sprays are always set to the actual number of sprays TE. n-Ist-MB =4. If the critical quality threshold m is reached during the lag state. krit Rated number of sprays TE n-Soll-MB It was reduced.
[0131] If the quality threshold m krit +m Offset In the lag state, m krit With m krit +m Offset The number of sprays TE according to the present invention is then reached. n-Soll-MB =4 In this embodiment (see Figure 6, especially I and III), it is twice raised to TE with n+1. n-Soll-MB =6 and set to the actual number of sprays TE n-Ist-MB =6.
[0132] The hysteresis state is advantageously used as follows, i.e., at a threshold m krit +m Offset With m krit The two can be switched back and forth without causing partial injection TE. n＝6 A permanent switch between the corresponding number of times n.
[0133] according to Figure 7B The L2 implementation in the diagram is in m krit +m Offset In the case of TE n-Soll-MB The above is based on mass switching, when at least one additional injection n+1 is possible and the critical mass m krit Not lower than when.
[0134] according to Figure 7B The diagram shows that L3 achieves at least one partial injection TE. n To TE n-Soll-MB The quality-based switching on n-1, at the critical mass m krit Before it is reached.
[0135] exist Figure 7A and 7B Legend L4 in the figure indicates the critical mass m below which the opening of the fuel injection valve cannot be reliably ensured. krit .
[0136] Finally, some embodiments relative to the previously mentioned defined operating states are shown, in which λ-rated jumps occur in particular.
[0137] Starting from stoichiometric operation λ=1, deviations from stoichiometric operation λ=1 occur in the following operating states: a) cold start (start-up adaptation), b) catalyst diagnostics (parallel), c) catalyst cleaning, or d) component protection events, resulting in an increase in the total fuel mass m traversed in each working cycle. Ges The changes.
[0138] These operating states are considered as follows when using the "quality-based operating mode" according to the invention.
[0139] a) Cold start (startup adaptation):
[0140] For example, as already explained, in the case of startup adaptation, additional partial injection of TE is performed after the detection of the quality-based switching by means of necessary enrichment (Anfettung) of the air-fuel mixture. n+1 (Additional partial injection) achieves additional necessary fuel mass so as to positively influence the homogenization of the air-fuel mixture, thereby better protecting the internal combustion engine from fuel entering the oil in an advantageous manner.
[0141] b) Catalyst diagnosis (parallel):
[0142] If the operating point BP, which depends on the load, remains unchanged, and the total injection quantity m increases or decreases due to other reasons... Ges (In the operating state of a catalyst diagnostic for exhaust systems, where the fuel quantity is changed independently of the user's power demand), the operating state of this "catalyst diagnostic" currently relates to the maximum possible number of partial injection TEs n. n-max Not to be affected in an adverse way.
[0143] According to the present invention, the following settings are made: during catalytic converter diagnostics, the lean adjustment of the air-fuel mixture (see...) Figure 6B In cases where the operating point is maintained in a quasi-static state (I to IV), this is advantageously considered in terms of the critical mass m. krit Switching is performed under certain circumstances, thus serving as the nth partial injection TE. n The alternative is to set at least one partial injection TE less often. n-1 .
[0144] Concentration adjustment of air-fuel mixture (see) Figure 6B In the case of I to V), at the same quasi-static operating point, however, the total injection volume m needs to be increased. Ges When considering the critical mass m krit In this case, switching is performed to achieve n partial injections TE. n The alternative is to set at least one partial injection TE. n+1.
[0145] c) Catalyst cleaning:
[0146] Even in the case of a clean catalyst, the air-fuel mixture is enriched. This is achieved by setting the system in a way that allows for at least one additional partial injection of TE in cases considering mass-based switching. n+1 .
[0147] d) Component protection events:
[0148] For component protection reasons, the air-fuel mixture is also enriched. This enrichment is similar to, in the case of catalyst cleaning, causing at least one additional partial injection TE in a favorable manner, considering a mass-based switching scenario. n+1 .
[0149] Torque reserve:
[0150] Finally, as another embodiment, the following configuration is made: even when the air-fuel mixture stably reaches the λ value, the internal combustion engine is still operated in torque reserve, such as idling, catalyst heating, particulate filter regeneration, and coolant heating. The quality-based operating mode, or its switching, is advantageously utilized in a manner that depends on the deterioration of engine efficiency, namely, achieving at least one additional partial injection TE. n+1 Switching on.
[0151] This invention also generally relates to a computer program suitable for performing the above-described methods when implemented on a computer. It is particularly preferred that the computer program is stored in a memory. The invention also relates to a control and / or regulation device for operating an internal combustion engine, particularly a motor vehicle, in which fuel is directly injected into the combustion chamber of the internal combustion engine. To optimize the operation of the internal combustion engine with respect to fuel consumption and emissions behavior, it is suggested according to the invention that the control and / or regulation device is suitable for and used for controlling and / or regulating the above-described methods. It is particularly preferred that the control and / or regulation device is equipped with a computer program of the above-described form. Finally, the invention relates to an internal combustion engine having at least one combustion chamber and a device for directly injecting fuel into the combustion chamber. To improve the operating characteristics of this internal combustion engine, particularly fuel consumption, emissions, and cold start characteristics, it is suggested according to the invention that the internal combustion engine is equipped with a control and / or regulation device.
[0152] List of reference numerals
[0153] KW crankshaft
[0154] °KW crankshaft angle in degrees
[0155] ZOT cylinder piston at top dead center during ignition
[0156] DRZ speed
[0157] The number of times n parts are sprayed or the nth spray.
[0158] Switching with n-1 fewer iterations
[0159] Switching with n+1 increments
[0160] TE n Partial spray
[0161] TE n-max Maximum possible partial injection TE n Number of times
[0162] TE n-Soll-BP Rated number of sprays (depending on operating point)
[0163] TE n-Soll-MB Rated number of sprays (based on mass)
[0164] K BPkalt The characteristic curve depends on the operating point during cold operation.
[0165] K MBkalt Quality-based characteristic curves during cold operation
[0166] K BPwarm The characteristic curves during hot operation depend on the operating point.
[0167] K MBwarm Mass-based characteristic curves during thermal operation
[0168] KL Hub Intake valve characteristic curve
[0169] KL Kolben Piston characteristic curve
[0170] KL Liner Characteristic curve of cylinder inner wall wetting
[0171] KL Zylk Cylinder piston wetting characteristic curve
[0172] ΔP stopping time
[0173] t min Minimum opening time
[0174] t oe Opening time
[0175] t as Time t at the end of the journey (Hubanschlag) s Closing Time
[0176] m fuel mass
[0177] m Ges Total injection mass (based on mass)
[0178] m BP Total injection mass (depending on operating point)
[0179] m krit Critical mass threshold
[0180] ? m krit Is the critical quality threshold lower than?
[0181] m Offset The numerical value m of the deviation of the injection mass from the critical mass threshold. krit +m Offset Quality threshold
[0182] Arrow indicating the critical range of P1
[0183] λλ
[0184] Line A
[0185] B-line BL1 Graphic Text
[0186] L2 Graphic Text
[0187] L3 Graphic Text
[0188] L4 Graphic Text
Claims
1. A method for operating an internal combustion engine of a motor vehicle, wherein fuel is partially injected (TE) at intervals between each other multiple times in each working cycle in a device for fuel injection. n The solution is directly injected into the combustion chamber of the internal combustion engine, involving the following steps: - Total injected mass (m³) into the combustion chamber per working cycle Ges The power requirement of the internal combustion engine depends on the determination of the quality of air supplied to the combustion chamber. - The manufacture of fuel / air mixtures taking into account a pre-defined air-fuel ratio. Its features The following steps are required: - The maximum possible number of partial injections per working cycle depends on the fuel injection valve associated with the corresponding combustion chamber in which each partial injection (TE) occurs. n The fuel quality is not lower than the critical mass threshold (m) krit ) and the determined total mass of spray to be sprayed in each work cycle (m) Ges ) verification, - The rated number of injections based on mass depends on the determination of the verified maximum possible number of partial injections and the total injection mass (m³). Ges The division is based on a determined number of mass-based rated sprays, and - Total injection mass per work cycle (m) Ges According to the mass-based determination, the part is divided into injection portions (TE). n The number of injections per unit fuel mass (m) is the rated number of injections. - Wherein, due to the minimum possible opening time (t) of the fuel injection valve depending on the rail pressure. min The critical quality threshold (m) defined in the case of ) krit The possible number of injections may be less than the previously verified rated number of injections, and the mass-based switching on the maximum possible verified rated number of injections is determined, and the total injection mass (m) is determined. Ges (to the verified maximum possible number of partial sprays) - Wherein, considering the minimum possible opening time (t) of the fuel injection valve depending on the rail pressure. min The critical quality threshold (m) reached in the case of ) krit In cases where the total injection mass (m) is likely to be lower than the previously verified rated number of injections, a mass-based switch is always performed from the maximum possible empirically verified rated number of injections, and the total injection mass (m) is determined. Ges The division of the partial sprays up to the maximum possible number of times verified.
2. The method according to claim 1, characterized in that, During the working cycle, multiple partial injections (TE) are placed based on mass during the intake and compression phases. n ), in which multiple partial injections are performed at different injection times (TE) n It is divided into the intake and compression stages in the two injection groups.
3. The method according to claim 1, characterized in that, A timely, quality-based switch to a fewer, verified number of partial injections is performed, ensuring that the amount of partial injection (TE) is not less than the required level. n At least once in the critical quality threshold (m) krit ), in the total spray mass (m Ges ) Partial spraying (TE) within the verified possible number of times n The division within ) is possible.
4. The method according to claim 1, characterized in that, Quality-based switching is performed on partial injections up to the verified maximum possible number of times, when the quality threshold (m) is reached. krit +m Offset When ) is reached, in the total spray mass (m Ges It is possible to divide the partial spray within the maximum possible number of times verified.
5. The method according to claim 4, characterized in that, At the critical mass threshold (m) krit ) and the quality threshold (m krit +m Offset The states are switched back and forth in a lag state.
6. The method according to claim 1, characterized in that, The previously verified rated number of injections is switched starting from the stoichiometric operation (λ=1) of the internal combustion engine in a defined operating state, wherein the stoichiometric operation (λ=1) is deviated from, thereby causing a change in the total injection mass passed through each working cycle and, if necessary, the verified rated number of injections.
7. The method according to claim 1, characterized in that, The previously validated rated number of injections is switched when the air-fuel mixture stably reaches the stoichiometric ratio and the internal combustion engine is running in torque reserve, wherein, depending on the efficiency degradation of the internal combustion engine, at least one additional partial injection (TE) is achieved. n+1 Switching on the device allows for a proven increase in the number of rated sprays.
8. The method according to claim 6, characterized in that, The determined operating states include a) cold start and / or b) catalyst diagnostics and / or c) catalyst cleaning and / or d) component protection events.
9. The method according to claim 7, characterized in that, The torque reserves include idling, catalyst heating, particulate filter regeneration, and coolant heating.
10. A computer program product, characterized in that, When the computer program is executed on a computer, the computer program is adapted to perform the method according to any one of claims 1 to 9, wherein the computer program is stored in memory.
11. A control and / or regulation device for an internal combustion engine used in operating a motor vehicle, wherein, The fuel is directly injected into the combustion chamber of the internal combustion engine, characterized in that it is suitable for controlling and / or regulating the method according to any one of claims 1 to 9, wherein the control and / or regulation device is provided with a computer program product according to claim 10.
12. An internal combustion engine having at least one combustion chamber and a device for fuel injection that directly injects fuel into the combustion chamber, characterized in that, It is equipped with the control and / or regulation device according to claim 11.