DE19952096C2 - Compression ignition internal combustion engine - Google Patents

Description

State of the art

The invention is based on an internal combustion engine Compression ignition according to the preambles of claim 1, claim 7 and claim 10.

An internal combustion engine with compression ignition is from the publication "Compression Ratio Effect On Methane HCCI Combustion" by Aceves S., Smith R., Westbrook C. and Pitz W., Paper No. 98-ICE-150, ASME 1998 known. In a homogeneous combustion process of the internal combustion engine described there, a decentralized activation of a charge in a combustion chamber by means of compression achieves a parallel release of energy, in contrast to processes that were previously common, in which central activation by means of an ignition source (Otto process) or by means of injection ( Diesel process) a serial combustion of the charge takes place with a gradually spreading flame front. The decentralized activation gives each charge element enough activation energy to reach the energy release level.

DE 198 04 988 C1 discloses a method for operating a Internal combustion engine in which with a homogeneous, lean basic mixture of Air and fuel and with compression ignition by means of a controllable Influencing element the fuel / air ratio formed in the combustion chamber is changeable. To adapt to changes as quickly as possible To achieve combustion processes, each is measured Combustion, and depending on what is obtained from this measurement The signal becomes the point in time at which the combustion chamber inlet element closes regulated for the next cycle.

DE 195 43 219 C1 describes a method for operating a diesel engine known in which an engine control in a rich / lean control Dependency on its operating parameters enables, with the help of a sensor arranged behind a storage catalytic converter for detection the NOx concentration in the exhaust gas flow, the regeneration of the NOx Storage catalyst is initiated. The regeneration operation through exhaust gas recirculation, increasing the exhaust gas back pressure or a supports additional fuel injection.

WO 98/10179 A2 discloses an internal combustion engine with a homogeneous Charge and compression ignition, which is a combustion Control device for controlling the combustion, an operating state detection device for monitoring the combustion and a Has control or processing device. In doing so Combustion parameters such as the start or duration of the combustion as well Mixture formation and compression set so that a homogeneous Diesel combustion, for example, by controlling variable ones Gas exchange valves can be realized and influenced.  

Special advantages in homogeneous combustion through decentralized activation of the charge result from the possibility of being able to completely burn extremely lean mixtures, which is why the fuel consumption drops. With the combustion of such extremely lean mixtures, on the other hand, low combustion temperatures are associated, which are usually below the temperature limit for the formation of nitrogen oxides (NO _x ), so that the nitrogen oxide emissions of such an internal combustion engine are low, at least at low load.

The auto-ignition of the charge within the combustion pro Processes, however, require a certain energy and temperature level level of cargo. To the temperature in the combustion chamber on the required The publication reveals a level of activation "The Knocking Syndrome - Its Cure and Its Potential" by J. Willand, SAE-Paper 982483, an internal combustion engine with a valve train for variable control of intake and exhaust valves to by ge suitable valve timing a certain amount of hot exhaust gas of the previous cycle to mix with the fresh load to be able to withhold the current cycle in the combustion chamber. Accordingly, the amount and temperature or the energy of the im Combustion chamber remaining exhaust gas, an essential control variable which the combustion process, especially the beginning and the Duration or focus of the implementation / combustion of the cargo, is controllable and regulatable.

As further possibilities for process control are in the known publication called preheating the intake air to raise the temperature in the combustion chamber to the required level. The ignition of one arranged in the combustion chamber serves the same purpose ten spark plug to check the temperature of the charge by initial ignition  and density on that for subsequent compression ignition increase required level. The initial spark is brief before the charge is necessary for compression ignition Has reached auto-ignition.

The present invention has for its object a Internal combustion engine with compression ignition mentioned at the beginning to create a type in which regulation of the Combustion process with a view to lower consumption and lower pollutant emissions is possible.

According to the invention, this object is characterized by ning part of claims 1, 7 and 10 mentioned features.

Advantages of the invention

The internal combustion engine according to the invention with compression Ignition according to claim 1 has the advantage that by changing the the position of the combustion process in Efficiency or consumption-optimal manner is noticeable. Control variables are the beginning and the duration of the order Settlement / combustion of the cargo, which except for consumption opt can also be adjusted to low-emission combustion sites can to reduce exhaust emissions. With the fiction The combustion process can also be regulated an incomplete combustion of the cargo, misfires and extreme steep pressure increases are avoided, which leads to a reduction in resulting noises during combustion and the mechani low engine load.

In the internal combustion engine according to claim 7, the Spark ignition before the auto-ignition occurs, so that  subsequently a combination of the usual flame front burns and a so-called "bulk combustion", which is also known as "low load Knocking "is the result. Spreads starting from the spark plug the flame front and compresses the charge in addition to Compression due to the piston movement until the auto-ignition conditions can be achieved. Thus there is the possibility of Spark ignition to affect the location of the combustion, at the same time remain the advantages of compression ignition, such as B. low gas temperature, short burning time, etc.

Since the internal combustion engine according to claim 10 with a λ- Control and catalytic exhaust gas aftertreatment is provided strict exhaust gas limits are also complied with, in particular re at higher load, if more nitrogen oxide occurs in the exhaust gas. Purpose The λ control is overridden at low load if the nitrogen oxide emissions are low anyway, and the internal combustion engine machine is operated with a lean air-fuel mixture.

By the measures listed in the subclaims are advantageous developments and improvements of the Pa Claims 1, 7 and 10 specified invention possible.

A particularly preferred development of the invention provides that the variably controllable intake and exhaust valves can be controlled by the control and regulating device such that in Dependency of the variables forming the control variables on the beginning and duration the conversion / combustion of the load during a cycle as additional manipulated variable a certain amount of exhaust gas in the combustion chamber retainable or traceable there and accordingly a be correct temperature of the retained or recirculated exhaust gas  is achievable, to determine the start and duration of the implementation charge / combustion for the next cycle.

The motor process is preferably a four-stroke process and at least one inlet valve and one outlet valve which are variable controllable intake and exhaust valves of a cylinder-piston unit can be controlled by the control device in such a way that the exhaust valve opening before one between one exhaust and one Intake stroke lying top charge change dead center position of a Piston and exhaust valve closing after this top charge Change dead center position essentially simultaneously with the inlet valve til-opening take place to exhaust gas from a combustion chamber of the cylinder Piston unit through the open exhaust valve into an exhaust port to push and then from the exhaust duct back into the combustion chamber suck back. Since the reused residual gas content does not run out the outlet channel is rinsed out, a so-called "in nere exhaust gas recirculation "realized.

Known methods for internal exhaust gas recirculation, in which e.g. B. the exhaust valve is closed early and this retains tene exhaust gas residue is then compressed, have the disadvantage that between the hot exhaust gas and the relatively cold Zy heat transfer takes place and thus the temperature of the exhaust gas drops undesirably. For solutions with large Valve overlap to increase the proportion of exhaust gas passes through the early opening of the exhaust valve from the combustion chamber in the relative cold intake duct and from there it is returned to the combustion chamber sucked, which is why the exhaust gas cools down and the desired increase charge temperature in the combustion chamber is not or only insufficiently appropriate entry. In contrast, is described in accordance with the above benen development of the invention, the hot exhaust gas in the outlet channel  pushed in which the wall temperatures are higher than that the cylinder wall, which is why the exhaust gas does not cool down and its for the desired increase in the energy level of the charge high tem maintains temperature.

The influence of exhaust gas retention or exhaust gas recirculation or the other manipulated variables on the homogeneous combustion pro zeß is by means of suitable sensors, for. B. combustion chamber pressure sensors, Ion current sensors or fiber optics using fiber optics, measured.

According to a further embodiment of the invention the control and regulating device a map memory with map in which manipulated variables of the actuators depend on the start and Duration of implementation / combustion of the cargo or the focus the implementation of the charge are deposited during a cycle in order to the start and duration of the implementation / combustion of the cargo or the focus of the implementation of the cargo for the fol cycle.

drawings

Embodiments of the invention are in the drawings shown and explained in more detail in the following description. It demonstrate:

Fig. 1 is a functional diagram of a control and regulating device of an internal combustion engine with compression ignition accelerator as the invention in a preferred embodiment;

FIG. 2 is a diagram in which the piston travel and the valve timing of the internal combustion engine of FIG. 1 are shown over the crank angle;

Figure 3a is a schematic cross-sectional view of a cylinder-piston unit of the engine of Figure 1 in egg nem crank angle of approximately 200 degrees..;

Figure 3b is a schematic cross-sectional view of the cylinder-piston unit at a crank angle of approximately 400 degrees.

3c is a schematic cross-sectional view of the cylinder-piston unit at a crank angle of approximately 500 degrees.

Fig. 4 is a diagram in which the combustion functions of a purely spark-ignited and a mixed spark-ignited and self-ignited combustion process are shown over the crank angle;

Fig. 5 is a diagram in which the course of the specific work of a mixed self-ignited and spark-ignition internal combustion engine is shown against the speed.

In the exemplary embodiment according to FIG. 1, the control and / or regulating device of an internal combustion engine 2 with compression ignition and 4-stroke cycle, which is designated overall by 1, serves to regulate the combustion process, in particular to regulate the start and duration of the implementation / combustion or Heat release of a charge located in a combustion chamber of the internal combustion engine 2 , formed by an air-fuel mixture. By changing the start and the duration of the implementation / combustion of the load, the "location" of the combustion process can be adapted to the respective boundary conditions in order to optimize it with regard to fuel consumption and exhaust gas emissions, which is why these variables are preferably controlled variables x of the control and regulating device 1 represent. The re gel track is formed by the internal combustion engine 2 , on which disturbance variables act z, z. B. in the form of changes in the temperature of the intake air or its pressure.

The control variables start and duration of the implementation / combustion of the charge can be measured by sensors 4 , preferably by a combustion chamber pressure sensor known per se and / or an ion current sensor, in order to provide electrical signals for a control device 6 for comparing the measured variables with corresponding control variables w generate which z. B. are stored in a map memory of the control device 6 . However, it is also possible to use a light guide sensor for generating electrical signals, which can measure the radiation intensity in the combustion chamber.

The internal combustion engine 2 includes the following manipulated variables y supply actuators 8 : variably controllable intake and exhaust valves, an injection system for injecting fuel into the combustion chamber. In addition, the internal combustion engine 2 can be charged, which is why it is a charging device, for. B. comprises an exhaust gas turbocharger with an intercooler for cooling the charge air. In addition, an exhaust gas recirculation device can be provided for external exhaust gas recirculation, in which a defined partial flow is taken from the exhaust gas of the internal combustion engine and fed to the fresh mixture via a valve controlled by the control device 6 . In addition, a heat exchanger can be provided to z. B. to use the existing heat in the cooling system of the internal combustion engine 2 for preheating the intake air in the intake manifold.

Depending on the comparison of the control variables x with the assigned reference variables w, the control unit 6 generates signals for controlling the actuators 8 mentioned in order to influence the combustion process of the internal combustion engine 2 . The variably controllable intake and exhaust valves are controlled by the control device 6 such that depending on the measured by the sensors 4 beginning and the duration of the implementation / combustion of the charge during a cycle as manipulated variables y a certain intake air mass and thus a certain Air ratio λ and a certain effective compression be generated to determine the start and duration of the implementation / combustion of the cargo for the next cycle. The injection system is controlled with the same aim in order to generate a specific injection pressure, a specific injection time and a specific injection quantity as manipulated variables y. In the case of multi-point injection, a certain inhomogeneity of the cylinder charge can also be generated.

Likewise, the charging device and the charge air cooler of the internal combustion engine can be controlled in order to supply charge air with a specific charge air temperature as a control variable y as a control variable y, depending on the start and duration of the ignition of the charge. The same also applies to the heat exchanger, which generates a certain temperature of the intake / charge air as a manipulated variable. The boost pressure of the intake / charge air can by pressure-influencing actuators 8 such. B. a bypass flap or a wastegate can be set. Finally, the exhaust gas recirculation device delivers as a manipulated variable a certain amount of exhaust gas that is returned to the combustion chamber.

It has been found that the quantity and temperature of the exhaust gas remaining or returned to the combustion chamber are essential influencing variables for controlling the combustion process. In order to enable in addition to the described external exhaust gas recirculation by the exhaust gas recirculation device also an internal exhaust gas retention, the internal combustion engine 2 has a variable valve control Ven preferably with electromagnetic or electrohydrau lic inlet and outlet valves.

In Fig. 2 and Fig. 3a to Fig. 3c is an example of a particularly preferred example of the valve control of an electromagnetic intake valve 10 and an electromagnetic exhaust valve 12 of a cylinder-piston unit 14 of the internal combustion engine 2 to realize an internal exhaust gas recirculation. In detail, the piston travel and the valve timing as a function of the crank angle are shown in diagram form in FIG. 2. In the motor process of the internal combustion engine 2 , it is preferably a well-known four-stroke process with an intake stroke, a sealing stroke, a working stroke and an exhaust stroke. Referring to FIG. 2 starting the Kol is ben 16 in an ignition top dead center _OT Z, which initiates the power stroke at a crank angle of zero degrees. The combustion of the air-fuel mixture takes place in a range between 10 degrees before _ZDC to approximately 10 degrees after _ZDC (zero degree crank angle). Shortly before the subsequent bottom dead center position of the piston 16 is reached , the outlet valve 12 - referred to as AÖ in FIG. 2 - opens in a crank angle range between 150 degrees and 180 degrees, preferably at 165 degrees. The exhaust valve 12 remains open during the subsequent exhaust stroke with upward movement of the piston 16 so that hot exhaust gas can be pushed into an outlet channel 18 , as illustrated by the piston position shown in FIG. 3a, at approximately 200 degrees crank angle. Instead of opening the inlet valve 10 as usual just before reaching an upper charge change dead center position LW _OT at a crank angle of 360 degrees, this remains closed until well into the now following suction cycle, so that the piston 16 moving to the bottom dead center position instead of fresh air previously pushed into the exhaust duct 18 , still hot exhaust gas is pulled back into the combustion chamber 20 , as the piston position shown in FIG. 3b illustrates at a crank angle of approximately 400 degrees. At the earliest at approximately 360 degrees crank angle (corresponds to 360 degrees before Z _OT ), fuel can be injected directly into the combustion chamber 20 via an injection nozzle 22 . However, an intake manifold injection is also possible, which is implemented, for example, during the intake of fresh air with the inlet valve open. A pre-storage of the fuel with the inlet valve still closed is also conceivable. Only after the exhaust gas has been sucked back into the combustion chamber 20 , does the intake valve 10 - referred to as EÖ in FIG. 2 - open in order to suck in fresh air from an intake duct 23 by means of the remaining residue of the downward movement of the piston 16 , as shown in FIG. 3c is illustrated with a crank angle position of approximately 500 degrees. The intake valve opening EÖ takes place essentially simultaneously with the exhaust valve closing AS in a crank angle range between 450 and 540 degrees, preferably at 470 degrees. After overcoming a bottom dead center position of the piston 16 , the closing of the inlet valve 10, designated ES, takes place in a crank angle range between 540 and 630 degrees, preferably at 560 degrees. During the subsequent compression of the air-fuel-exhaust gas mixture brought to a higher energy level by the recirculated hot exhaust gases, its auto-ignition is finally triggered in the region of the upper ignition dead center position Z _OT .

In order to influence the controlled variables start and duration of the implementation / combustion of the charge in the combustion chamber 20 , electrical signals from the regulating device 6 to the electromagnetic intake and exhaust valves 10 , 12 are controlled to control the crank angle of the exhaust valve closing AS and the intake valve. Opening EÖ within the above-mentioned crank angle ranges to move to higher or lower crank angles, the crank angle distance between the exhaust valve opening AÖ and intake valve closing ES preferably remains essentially constant.

The exhaust valve closing AS and intake valve opening EÖ er follows approximately in the same crank angle range. Ideally takes place the exhaust valve closing AS and the intake valve opening EÖ in the we held at the same time. Under the focus of Ver the time of a 50% conversion of the sprayed fuel mass understood.

Because of their importance for the combustion process, the amount of exhaust gas remaining or returned to the combustion chamber can also be control variable x instead of control variable y, in which case the inlet and exhaust valves 10 , 12 are controlled by the control device 6 in such a way that, depending on the quantity in the combustion chamber 20 restrained or returned exhaust gas amount during a cycle as manipulated variables, for example, the control times of the intake and exhaust valves 10 , 12 described above for determining the remaining in the combustion chamber 20 or returned exhaust gas amount for the next cycle can be generated.

According to a further development, an ignition system that can be controlled by the control device 6 is provided with one spark plug per cylinder for spark ignition of the air-fuel mixture in the combustion chamber 20 , the spark ignition occurring before the self-ignition of the air-fuel mixture that subsequently occurs. Starting from the spark plug, the flame front spreads and compresses the tail gas in addition to compression due to the piston movement until the auto-ignition conditions are reached. In this respect, spark ignition is only an initial spark for the subsequent auto-ignition. This fact is illustrated by FIG. 4, in which the combustion functions of combustion processes are shown over the crank angle. The curve 24 drawn in dash-dotted lines represents the course of the combustion function as it would be if the combustion process were controlled exclusively by a spark and no auto-ignition would take place. In contrast, the combustion function curve 26 drawn in dashed lines results when an external or initial ignition is initially carried out in order to create the conditions for the subsequent auto-ignition. The curve shape 26 of the burner function is characterized in the latter case by two sections, a first section 28 in which, because of the initial ignition, the flame front gradually spreads starting from the spark plug and a subsequent second section 30 , in which the auto-ignition of the takes place through the initial ignition of a higher energy level air-fuel mixture. Because of the initially exclusively spark-ignited combustion, the curve shape 26 of the combustion function in the first section 28 is parallel to the combustion function curve 24 with exclusively spark ignition, while it becomes steeper in the second section 30 because of the faster conversion.

The internal combustion engine 2 can, according to the invention, be provided with a λ control for the air ratio λ in order to regulate an essentially stoichiometric mixture (λ = 1) in the combustion chamber as a function of the air ratio λ measured by a λ sensor. A conventional three-way catalytic converter is advantageously provided for exhaust gas purification. Since the nitrogen oxide emissions increase especially at higher loads, the λ control is preferably only effective at higher loads, while in areas where the load is low and the nitrogen oxide emissions are low, the internal combustion engine continues to have a lean air / fuel mixture (λ <1) and is operated without λ control.

FIG. 5 shows a diagram in which the specific work p _{m of} a further embodiment of the internal combustion engine according to the invention is shown over the speed n. As already described above, due to the negligible formation of nitrogen oxides in a lower, by a lean mixture (λ <1) characterized load area 32 to an additional exhaust gas cleaning z. B. can be dispensed with by conventional three-way catalysts. In a medium load range 34 , λ control (λ = 1) is preferably put into force because of the nitrogen oxides that accumulate there to enable catalytic exhaust gas aftertreatment. Based on the assumption that the homogeneous combustion process reaches its limits with the usual internal combustion engines in a higher load range 36 , the load is preferably switched to a conventional, purely spark-ignited combustion process when the load increases from the auto-ignition prevailing in the medium load range 34 . This means that from a limit load p _m limit, the charge no longer self- _ignites , but instead spark ignition by means of a spark plug. The exhaust gas cleaning in the higher load range 36 is in turn accomplished by means of conventional 3-way catalysts, which is why the λ control is effective. Because of the regulation of the air ratio λ to the value λ = 1, both in the middle load range 34 and in the higher load range 36 , the transition from the self-ignited combustion to the purely externally ignited combustion and vice versa is made considerably easier. In contrast, the usual full-load enrichment (λ <1) takes place in the full-load region 38 .

Instead of regulation, according to a further embodiment, the combustion process can be controlled by providing a control unit with a map memory with maps or characteristic curves in which the manipulated variables y of the actuators 8 mentioned depend on the operating state, instead of the control device 6 from FIG. 1 and disturbance variables are stored in order to determine the start and duration of the combustion / implementation of the charge for the following cycle. The manipulated variables y stored in the characteristic diagrams or characteristic curves may have been determined empirically, arithmetically (simulation) or by estimation.

Claims (10)

1. Internal combustion engine ( 2 ) with compression ignition comprising the following actuating variables y actuators ( 8 ) for controlling a multi-cycle motor process: variably controllable intake and exhaust valves ( 10 , 12 ), an injection system for direct injection of fuel into a combustion chamber ( 20 ) or for injection into an intake pipe, and a control and / or regulating device ( 1 ) for controlling and regulating the combustion process, characterized in that the variably controllable intake and exhaust valves ( 10 , 12 ) and the injection system by the control and / or Control device ( 1 ) can be controlled in such a way that, depending on a point in time of the 50% conversion of the injected fuel mass during a cycle, a certain air ratio λ, a certain effective compression, a certain injection pressure, a certain injection time and a certain as control variables (y) Injection quantity to determine B The start and duration of the combustion / implementation of the load or the focus of the combustion can be generated for the next cycle. 2. Internal combustion engine according to claim 1, characterized in that the variably controllable intake and exhaust valves ( 10 , 12 ) are preferably electromagnetic or electrohydraulic valves and can be controlled by the control and regulating device ( 1 ) such that depending on the controlled variables (x) Formative variables Start and duration of the combustion / implementation of the charge or focus of the combustion during a cycle as control variables (y) a certain amount of exhaust gas can be retained or traced back to the combustion chamber and a specific temperature of the retained or recirculated exhaust gas can be achieved to determine the start and duration of the combustion / implementation of the load or focus of the combustion for the next cycle. 3. Internal combustion engine according to claim 2, characterized in that the motor process is a four-stroke process and at least one inlet valve ( 10 ) and one outlet valve ( 12 ) of the variably controllable inlet and outlet valves of a cylinder-piston unit ( 14 ) by the control and control means (1) may be controlled such that the exhaust valve opening (AO) before lying between a discharge and an intake stroke top dead center gas exchange (LW _TDC) of a piston (16) and the exhaust valve closing (AS) according to this Upper charge cycle dead center position (LW _OT ) take place essentially simultaneously with the opening of the intake valve (EÖ) to exhaust gas from a combustion chamber ( 20 ) of the cylinder-piston unit ( 14 ) through the opened exhaust valve ( 12 ) into an exhaust port ( 18 ) slide and then suck back into the combustion chamber ( 20 ) from the outlet channel ( 18 ). 4. Internal combustion engine according to claim 3, characterized in that when the top dead center position (LW _OT ) is defined by a crank angle of 360 degrees, the intake and exhaust valves ( 10 , 12 ) have the following preferred timing

• a) opening the exhaust valve ( 12 ) in a crank angle range between 150 degrees and 180 degrees, preferably at 165 degrees;
• b) closing the exhaust valve ( 12 ) and essentially simultaneously opening the intake valve ( 10 ) in a crank angle range between 450 degrees and 540 degrees, preferably at 470 degrees; and
• c) Closing the inlet valve ( 10 ) in a crank angle range between 540 and 630 degrees, preferably at 560 degrees.

5. Internal combustion engine according to one of claims 2 to 4, characterized in that a pilot control is integrated in the control and regulating device ( 1 ) depending on the desired amount of the exhaust gas retained or returned there in the combustion chamber ( 20 ). 6. Internal combustion engine according to one of the preceding claims, characterized in that it further comprises the following actuating variables y actuators ( 8 ): a charging device for charging the engine with charge air, a charge air cooler for cooling the charge air, a heat exchanger for preheating intake / Charge air, an exhaust gas recirculation device for external exhaust gas recirculation, the charging device being controllable by the control and regulating device ( 1 ) in such a way that, depending on the variables (x) forming variables, the start and duration of the combustion / conversion of the charge or focus of the combustion during a cycle a specific boost pressure can be generated as the manipulated variable (y), and the charge air cooler can be controlled such that, depending on the variables forming the controlled variables (x), the start and duration of the combustion / conversion of the charge or the focus of the combustion during a cycle as a manipulated variable (y) determined Lu guidance of the charge air is adjustable, and the heat exchanger can be controlled in such a way that, depending on the variables forming the control variables (x), the start and duration of the combustion / conversion of the charge or the focus of the combustion during a cycle as a control variable (y) a specific preheating of the intake / Charge air takes place, and the exhaust gas recirculation device can be controlled in such a way that, depending on the variables that form the control variables (x), the start and duration of the combustion / implementation of the charge or the focus of the combustion during a cycle as a control variable (y) a certain amount of exhaust gas into the combustion chamber ( 20 ) is returned to determine the start and duration of the combustion / implementation of the load or focus of the combustion for the next cycle. 7. Internal combustion engine ( 2 ) with compression ignition comprising the following manipulated variables y actuators ( 8 ) for controlling a multi-cycle motor process: variably controllable intake and exhaust valves ( 10 , 12 ), an injection system for the direct injection of fuel into a combustion chamber ( 20 ) or for injection into an intake pipe, and a control and / or regulating device (1), characterized in the control and regulation of the combustion process, that one (1) in such a manner controllable ignition system of the regulating and / or control device is provided that this just before Reaching the conditions necessary for the compression ignition generates at least one ignition spark to cause an initial ignition in the combustion chamber ( 20 ), the inlet and exhaust valves ( 10 , 12 ) being controlled in such a way that a relatively high proportion of exhaust gas prevails in the combustion chamber ( 20 ) in the part-load range . 8. Internal combustion engine according to one of the preceding claims, characterized in that at least one combustion chamber pressure sensor ( 4 ) and / or at least one ion current sensor ( 4 ) and / or at least one light guide sensor for generating electrical signals as a function of the measured pressure and / or the measured ion current in Combustion chamber ( 20 ) and / or the measured radiation intensity is provided as input variables for a control device ( 6 ) of the control and / or regulating device ( 1 ), which influence the control variables (x). 9. Internal combustion engine according to one of the preceding claims, characterized in that the control and regulating device ( 1 ) includes a control unit with maps stored in a map memory, in which manipulated variables (y) of the actuators ( 8 ) depending on the start and duration of the implementation / Combustion of the load or focus of the combustion are stored during a cycle in order to determine the start and duration of the implementation / combustion of the load for the following cycle. 10. Combustion engine with compression ignition and with setting values for the air ratio λ of an air-fuel mixture in a combustion chamber ( 20 ) enabling actuators ( 8 ), wherein it includes a control device ( 1 ) for the air ratio λ to in dependence on the to set a target value for the air ratio λ measured by a λ sensor and that a device for the catalytic afterburning of exhaust gases, in particular a three-way catalytic converter, is further provided, characterized in that the control device ( 1 ) is designed in this way is that in a low load area ( 32 ) a lean air-fuel mixture (λ <1) with the λ control deactivated and in a medium load area ( 34 ) an essentially stoichiometric mixture (λ = 1) λ regulation in force can be adjusted and that the combustion process when a limit load (p _mlimit ) is exceeded in the range The low and medium load ( 32 , 34 ) predominant compression ignition for a region of higher load ( 36 ) can be switched to a pure spark ignition.