DE102016204297A1 - Direct-injection spark-ignition internal combustion engine with injection device arranged in the cylinder tube and method for operating such an internal combustion engine - Google Patents

Abstract

The invention relates to a direct-injection spark-ignition internal combustion engine having at least one cylinder (1), in which - each cylinder (1) comprises a combustion chamber (2, 2a, 2b) which is defined by a piston head (5a) of a piston (5), a cylinder tube (5). 4) and the at least one cylinder head (3) is formed with, and - each cylinder (1) in the cylinder tube (4) is equipped with an injection device (6) which has at least two openings. It is intended to provide a spark-ignited internal combustion engine in which the mixture formation, in particular the homogenization of the fuel-air mixture, is improved. This is achieved with a spark-ignited internal combustion engine, which is characterized in that - the at least two openings form at least two groups, each with at least one opening, - the at least one opening of a first group is not aligned with the piston head (5a), whereas at least one Opening a second group on the piston head (5a) is aligned, and - the at least two groups each having at least one opening in the context of an injection process are activated offset in time, wherein the at least one opening of the first group earlier than the at least one opening of the second group is activated.

Description

• – jeder Zylinder einen Brennraum umfasst, der durch einen Kolbenboden eines zylinderzugehörigen Kolbens, ein den Brennraum seitlich begrenzendes Zylinderrohr und den mindestens einen Zylinderkopf mit ausgebildet ist, wobei der Kolben entlang einer Kolbenlängsachse zwischen einem unteren Totpunkt und einem oberen Totpunkt bewegbar ist, und
• – jeder Zylinder in einem Bereich des Zylinderrohres mit einer Einspritzvorrichtung zum direkten Einbringen von Kraftstoff in den Brennraum ausgestattet ist, die über mindestens zwei Öffnungen verfügt, welche im Rahmen eines Einspritzvorganges zwecks Einbringens von Kraftstoff in den Brennraum aktivierbar sind.

The invention relates to a direct-injection spark-ignition internal combustion engine having at least one cylinder head comprising at least one cylinder, in which

• - Each cylinder comprises a combustion chamber which is formed by a piston head of a cylinder-associated piston, a combustion chamber, the laterally delimiting cylinder tube and the at least one cylinder head, wherein the piston along a piston longitudinal axis between a bottom dead center and a top dead center is movable, and
• - Each cylinder is provided in an area of the cylinder tube with an injection device for directly introducing fuel into the combustion chamber, which has at least two openings which can be activated in the context of an injection process for the purpose of introducing fuel into the combustion chamber.

Furthermore, the invention relates to a method for operating such a spark-ignited internal combustion engine.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine includes spark ignited gasoline engines, but also spark ignited hybrid internal combustion engines, d. H. spark-ignition internal combustion engines, which are operated with a hybrid combustion method, and hybrid drives, which include in addition to the spark-ignition internal combustion engine drive-connected with the electric motor, which receives power from the engine or emits additional power as a switchable auxiliary drive.

Internal combustion engines have a cylinder block and at least one cylinder head, which are connected to form the cylinders and their combustion chambers with each other or are. The cylinder block is used regularly as an upper crankcase half for supporting the crankshaft and for receiving the piston or the cylinder liner of each cylinder. The piston can also be stored and guided by omitting a bush as an intermediate element directly in a bore of the block. In the context of the present invention, both the cylinder liner and the bore are subsumed under the term cylinder tube.

The cylinder head usually serves to accommodate the valve trains required for the charge cycle. As part of the charge exchange, the discharge of the combustion gases via Abgasabführsystem via the at least one outlet opening and the supply of combustion air via the intake system via the at least one inlet opening of the cylinder takes place. According to the state of the art, almost exclusively globe valves are used in four-stroke engines for controlling the gas exchange. The valve, including the associated actuating mechanism, is referred to as a valvetrain.

The crankshaft mounted in the crankcase receives the connecting rod forces and transforms the oscillating stroke movement of the pistons into a rotating rotational movement of the crankshaft. The upper crankcase half formed by the cylinder block is regularly supplemented by the sump which can be mounted on the cylinder block and serves as the lower crankcase half.

In the development of internal combustion engines, efforts are constantly being made to minimize fuel consumption and reduce pollutant emissions.

The problem is the fuel consumption, especially in gasoline engines, d. H. in spark-ignition internal combustion engines. The reason for this lies in the principle working method of the traditional gasoline engine. The traditional gasoline engine operates with an outer mixture formation and a homogeneous fuel-air mixture, wherein the adjustment of the desired performance by changing the filling of the combustion chamber takes place, d. H. by means of a quantity regulation. By adjusting a throttle valve provided in the intake system, the pressure of the intake air downstream of the throttle valve can be more or less reduced. With a constant combustion chamber volume, the air mass, d. H. the quantity will be set. This also explains why the quantity control proves to be disadvantageous especially in part-load operation, because low loads require high throttling and pressure reduction in the intake system, whereby the charge exchange losses increase with decreasing load and increasing throttling.

One solution for the dethrottling of the Otto engine work process offers the direct injection of the fuel. The injection of the fuel directly into the combustion chamber of the cylinder is regarded as a suitable measure to noticeably reduce fuel consumption even in gasoline engines. The Entdrosselung the internal combustion engine is realized that within certain limits, a quality control is applied.

With the direct injection of the fuel into the combustion chamber, in particular, a stratified combustion chamber charge can be realized, which can significantly contribute to the dethrottling of the Otto engine operating method, since the internal combustion engine is greatly emaciated with the aid of stratified charge operation can be, especially in part-load operation, ie in the lower and middle load range, if only small amounts of fuel are injected, thermodynamic advantages.

The direct injection is characterized by an inhomogeneous combustion chamber charge, which is not characterized by a uniform air ratio, but regularly has both lean (λ> 1) mixture parts as well as rich (λ <1) mixture parts. The inhomogeneity of the fuel-air mixture is also a reason that the known from the diesel engine process particle emissions in direct-injection gasoline engine are also relevant, whereas these emissions have almost no significance in traditional gasoline engine.

For the injection of the fuel, the mixture preparation in the combustion chamber, namely the mixing of air and fuel and the preparation of the fuel in the context of pre-reactions including evaporation, and the ignition of the treated mixture is comparatively little time available.

The internal combustion engine object of the present invention is a direct-injection spark-ignition internal combustion engine.

Since there is little time for mixture formation in direct injection, measures are needed to support and accelerate mixture formation in order to homogenize the fuel-air mixture as far as possible before ignition; at least as long as no stratified charge operation is desired. Of particular importance in this context is the distribution of the fuel in the combustion chamber and thus also the injection of the fuel.

In order to improve the mixture formation, it is common in the prior art to use a pilot injection of fuel, in which a small amount of fuel is introduced into the cylinder before the actual main injection. The pilot injection also has an advantageous effect on the nitrogen oxide emissions and lowers the pressure gradient, which in particular reduces the noise emissions.

However, internal combustion engines that make use of a pilot injection are inherently very susceptible to dilution or contamination of the oil by unburned hydrocarbons. Depending on the quantity of the fuel and the injection timing, a more or less large portion of the fuel in the pilot injection reaches the cylinder inner wall, in particular the cylinder tube, and mixes with the oil film adhering there. Subsequently, the fuel, together with the oil and the blow-by gas, enters the crankcase and contributes significantly to the oil dilution. The oil dilution increases with increasing fuel quantity and shifting the pilot injection to early, which is why often later, d. H. in the last third of the compression phase, in which the piston moves during the change of charge from bottom dead center to top dead center, is pre-injected. By changing the lubricant properties of the oil, the oil dilution has a significant influence on the wear and the durability, d. H. the life of the internal combustion engine.

In the wall-guided method, which is used in direct-injection spark-ignited internal combustion engines, the fuel is injected in such a way that the injection jet impinges on a combustion chamber bounding wall, preferably in a recess provided on the piston crown, wherein the fuel jets split by the impact into a plurality of partial beams and be deflected so that the largest possible area of the combustion chamber is detected by the fuel jets.

Basically, however, a wetting of the combustion chamber inner walls, including the piston crown, with injected fuel should be prevented.

A forced charge motion, such as a tumble or a spin, can accelerate and aid mixture formation. A tumble is an air vortex about an imaginary axis which is parallel to the longitudinal axis, i. H. runs to the axis of rotation of the crankshaft. A spin represents an air vortex whose axis is parallel to the piston d. H. Cylinder longitudinal axis runs.

From the prior art concepts are known in which the cylinders of the internal combustion engine are each equipped in the region of the cylinder tube with an injection nozzle. The injection nozzle of a cylinder is aligned with the cylinder head; in an individual case on the exhaust valve of the cylinder. This measure is intended to assist and accelerate the vaporization of the fuel particles or fuel droplets and thus the mixture formation. At the same time, the head or the closed outlet valve is cooled by means of fuel. Furthermore, there should be advantages in pollutant emissions. It is also possible to provide two injection nozzles which optionally interact with one another, whereby the mixture formation is to be further improved. The US 5,421,301 describes such an internal combustion engine.

A disadvantage of the in the US 5,421,301 Injection method described in general and on internal combustion engines whose cylinders in the field of Cylinder tube are equipped with an injection device, is that an injection can be made only when the cylinder-associated piston has passed on its way to the bottom dead center of the injector and makes the combustion chamber for the openings of the injector accessible. As a result, the crank angle window, in which an injection can basically take place, is severely restricted. This is all the more relevant, as with direct injection from home very little time is available for the mixture formation.

An injection nozzle, which - as in the US 5,421,301 In the context of the injection process, only the cylinder-head-side region of the combustion chamber is supplied with fuel, whereas the area of the combustion chamber between injector and bottom dead center, ie the piston-side region of the combustion chamber, is ignored during injection.

In view of the foregoing, it is an object of the present invention to provide a direct-injection spark-ignition internal combustion engine according to the preamble of claim 1, in which the mixture formation, in particular the homogenization of the fuel-air mixture, is improved.

Another object of the present invention is to provide a method of operating such an internal combustion engine.

• – jeder Zylinder einen Brennraum umfasst, der durch einen Kolbenboden eines zylinderzugehörigen Kolbens, ein den Brennraum seitlich begrenzendes Zylinderrohr und den mindestens einen Zylinderkopf mit ausgebildet ist, wobei der Kolben entlang einer Kolbenlängsachse zwischen einem unteren Totpunkt und einem oberen Totpunkt bewegbar ist, und
• – jeder Zylinder in einem Bereich des Zylinderrohres mit einer Einspritzvorrichtung zum direkten Einbringen von Kraftstoff in den Brennraum ausgestattet ist, die über mindestens zwei Öffnungen verfügt, welche im Rahmen eines Einspritzvorganges zwecks Einbringen von Kraftstoff in den Brennraum aktivierbar sind, und die dadurch gekennzeichnet ist, dass
• – die mindestens zwei Öffnungen in der Art konfiguriert sind, dass diese mindestens zwei Gruppen mit jeweils mindestens einer Öffnung bilden,
• – die mindestens eine Öffnung einer ersten Gruppe nicht auf den Kolbenboden des zylinderzugehörigen Kolbens ausgerichtet ist, wohingegen mindestens eine Öffnung einer zweiten Gruppe auf den Kolbenboden des zylinderzugehörigen Kolbens ausgerichtet ist, wobei Bezug genommen wird auf eine Position des Kolbens, in der der Brennraum für die mindestens zwei Öffnungen zugänglich ist und der Kolben sich möglichst nahe am oberen Totpunkt befindet, und
• – die mindestens zwei Gruppen umfassend jeweils mindestens eine Öffnung im Rahmen eines Einspritzvorganges zeitlich versetzt aktivierbar sind, wobei die mindestens eine Öffnung der ersten Gruppe früher als die mindestens eine Öffnung der zweiten Gruppe aktiviert ist.

The first sub-task is solved by a direct-injection spark-ignited internal combustion engine with at least one cylinder head comprising at least one cylinder in which

• - Each cylinder comprises a combustion chamber which is formed by a piston head of a cylinder-associated piston, a combustion chamber, the laterally delimiting cylinder tube and the at least one cylinder head, wherein the piston along a piston longitudinal axis between a bottom dead center and a top dead center is movable, and
• Each cylinder in a region of the cylinder tube is equipped with an injection device for direct introduction of fuel into the combustion chamber, which has at least two openings which can be activated in the combustion chamber during an injection process for introducing fuel, and which is characterized that
• - The at least two openings are configured in such a way that they form at least two groups, each with at least one opening,
• - The at least one opening of a first group is not aligned with the piston head of the cylinder-associated piston, whereas at least one opening of a second group is aligned with the piston head of the cylinder-associated piston, wherein reference is made to a position of the piston in which the combustion chamber for the at least two openings is accessible and the piston is as close as possible to top dead center, and
• - The at least two groups comprising at least one opening in the context of an injection process are activated offset in time, wherein the at least one opening of the first group is activated earlier than the at least one opening of the second group.

In the internal combustion engine according to the invention, the openings of the cylinder-associated injection device are grouped, wherein the different groups, each comprising at least one opening, are activated with a time delay, d. H. be activated successively to form a time interval. Due to the time-delayed activation of the openings, different regions of the combustion chamber can be at different times or crank angles, i. H. be supplied with injected fuel at different piston positions.

Thus, as part of an injection process, first the cylinder-head-side region of the combustion chamber can be supplied with fuel and the piston-side region of the combustion chamber, i. H. the area between the bottom dead center or the piston crown and the openings, at a later time.

This way of injecting fuel, d. H. the inventive design of the injection process, takes into account the fact that not all areas of the combustion chamber are simultaneously available for the injection of fuel and fuel can only be injected when the cylinder-related piston makes the respective combustion chamber area accessible to the injector, d. H. releases. In addition, it is taken into account that with direct injection very little time is available for mixture formation and therefore the time available for the injection should be used as extensively as possible. According to the invention, the injection process can start as soon as the piston makes the combustion chamber accessible to the at least two openings.

Periodically, the opening of an injector is activated by connecting and releasing that port to a fuel supply system for the purpose of introducing fuel into the cylinder.

The injection process is terminated by the fact that the openings are separated from the fuel supply system, ie deactivated. According to the invention, the deactivation of the openings can also be carried out with a time delay.

With the internal combustion engine according to the invention, the first sub-task underlying the invention is achieved, namely provided a direct-injection spark-ignition internal combustion engine according to the preamble of claim 1, in which the mixture formation, in particular the homogenization of the fuel-air mixture is improved.

The homogenization of the fuel-air mixture also gains in importance in terms of reducing nitrogen oxide emissions, since the formation of nitrogen oxides requires not only an excess of air, but also high temperatures and therefore increasingly combustion processes with lower combustion temperatures are used, such as the HCCI Homogeneous-charge compression-ignition, also referred to as space ignition method or CAI (Controlled Auto-Ignition) method based on a controlled auto-ignition of the fuel supplied to the cylinder. Due to the low combustion temperatures, an internal combustion engine operated in HCCI mode has comparatively low nitrogen oxide emissions and likewise low or almost no soot emissions.

Due to the lower combustion temperatures and the associated lower temperature differences in the internal combustion engine, the heat losses are lower than in conventionally operated internal combustion engines. This leads to a higher thermal efficiency.

Further advantageous embodiments of the internal combustion engine according to the invention are discussed in connection with the subclaims.

Embodiments of the direct-injection spark-ignited internal combustion engine in which the at least one opening in each case can be deactivated in an offset manner within an injection process are advantageous, wherein the at least one opening of the second group is deactivated earlier than the at least one opening of the first group.

This approach takes into account in particular the fact that the piston to be moved to the top dead center first sweeps over the region of the combustion chamber between the bottom dead center and the openings before the at least one opening of the first group is passed and the piston into the cylinder head side region of the combustion chamber enters. The at least one opening of the second group is therefore preferably to be deactivated earlier; at least if the injection process extends into the compression stroke of the charge exchange.

If the injection device has a movable, for example translationally displaceable, closure body which activates the at least two openings in the context of an injection process for the introduction of fuel and according to the inventive design of the injection first, the at least one opening of the first group and temporally spaced the at least one opening of the As a rule, when the second group is released, in the reverse direction when deactivating the openings, the at least one opening of the second group is deactivated earlier than the at least one opening of the first group.

Embodiments of the direct-injection spark-ignited internal combustion engine in which at least one opening of the first group is aligned with the at least one cylinder head are advantageous.

If, in the context of the present invention, the orientation of an opening is mentioned, reference is thus made to the injection jet or fuel jet emerging from this opening.

In the present case, at least one injection jet of the first group of openings is directed onto the cylinder head, i. H. in an individual case on an exhaust valve or an inlet opening of the cylinder. This supports the evaporation of the fuel and accelerates the mixture formation. An air flow entering via the inlet opening into the combustion chamber, together with the injection jet, can ensure the distribution of the fuel in the cylinder head side region of the combustion chamber. At the same time it is avoided that the piston crown is wetted with fuel.

Also advantageous are embodiments of the direct-injection spark-ignited internal combustion engine, in which at least one opening of the first group is aligned perpendicular to the piston longitudinal axis of the cylinder-associated piston. It is a borderline case.

In this case too, the injection of fuel can be started as soon as the piston has passed the injection device or its openings on the way to bottom dead center, without the piston bottom being wetted with fuel.

Also advantageous are embodiments of the direct-injection spark-ignited internal combustion engine, in which at least one opening of the second group is aligned perpendicular to the piston longitudinal axis of the cylinder-associated piston.

Embodiments of the direct-injection spark-ignited internal combustion engine in which the injection device of each cylinder is aligned perpendicular to the piston longitudinal axis of the cylinder-associated piston are advantageous.

However, embodiments of the direct-injection spark-ignited internal combustion engine in which the injection device of each cylinder is inclined to the piston longitudinal axis of the cylinder-associated piston can also be advantageous.

In this context, embodiments of the direct-injection spark-ignited internal combustion engine in which the injection device of each cylinder is inclined to the piston longitudinal axis of the cylinder-associated piston and is aligned with the at least one cylinder head are advantageous.

Advantageous embodiments are the direct-injection spark-ignited internal combustion engine in which the injection device has a movable closure body which forcibly controls, in the course of an injection process, the at least two openings for the purpose of introducing fuel into the combustion chamber with a fuel supply system and thereby releases, the closure body staggering the openings successively releases, in such a way that at a top dead center to the bottom dead center to moving piston first, the at least one opening of the first group and spaced in time, the at least one opening of the second group is released.

The movable closure body separates the at least two openings of the fuel supply system in a rest position, whereby the openings are deactivated or are. In a first working position, the at least one opening of the first group is already connected to the fuel supply system, while the at least one opening of the second group is still separated from the fuel supply system. If the closure body is then transferred to a second working position, in addition to the at least one opening of the first group, the at least one opening of the second group is connected to the fuel supply system.

The fuel supply system may include a pump, a storage container, d. H. a fuel storage, and / or a fuel line, for example, the common supply line of a common rail system include. The fact that when activating or deactivating is switched off regularly to connect or disconnect from the fuel supply system, is due to the fact that to open and stop the injection process, the openings are not regularly opened or closed, but often only with the fuel supply connected or disconnected from the fuel supply.

The closure body, for example the spherical tip of a nozzle needle, may be electromagnetically, piezoelectrically or otherwise actuated, i. H. moved and transferred from one position to another position, wherein the closure body can take several working positions.

In this context, embodiments in which the movable closure body is translationally displaceable are advantageous.

In the case of an injection nozzle that opens inward, for example, a nozzle needle can be moved translationally in order to transfer a ball-shaped closure body arranged at the combustion chamber end of the nozzle needle from the rest position into a working position. In the working position, the ball-like closure body releases the openings of the first group and / or the openings of the second group by connecting to the fuel supply system of the internal combustion engine.

In the present context, embodiments of the direct-injection spark-ignited internal combustion engine in which the movable closure body deactivates the at least two openings for the purpose of terminating the injection process are advantageous in the context of an injection process, the closure body deactivating the openings successively in time, such that the at least one opening is first of all deactivated the second group and spaced apart the at least one opening of the first group is deactivated.

In the present context, embodiments of the direct-injection spark-ignited internal combustion engine are also advantageous, in which the movable closure body deactivates the at least two openings in order to terminate the injection process as part of an injection process, wherein the closure body deactivates the openings successively in time, in such a way that at one of bottom dead center to the top dead center to moving piston first, the at least one opening of the second group and spaced in time, the at least one opening of the first group is deactivated.

Embodiments of the direct injection spark ignited are advantageous Internal combustion engine, in which the injection device is an injection nozzle, which has the at least two openings.

In this context, embodiments are advantageous in which the injection nozzle is equipped with a nozzle needle which is displaceable in the direction of a longitudinal axis in a nozzle needle guide which, as part of an injection, connects at least two nozzle holes functioning as openings for the purpose of introducing fuel into the fuel supply system and thereby releases them.

Embodiments of the direct-injection spark-ignited internal combustion engine in which a closure body is arranged at a free end of the nozzle needle, wherein the free end of the nozzle needle is the end of the combustion chamber are advantageous.

If the injection device is an injection nozzle, embodiments of the internal combustion engine are advantageous in which the injection nozzle is equipped with a spherical closure body.

If the injection device is an injection nozzle, embodiments of the internal combustion engine may also be advantageous in which the injection nozzle is equipped with a spherical closure body.

Embodiments of the direct-injection spark-ignited internal combustion engine in which the injection device comprises two injection nozzles may also be advantageous, wherein a first injection nozzle has the at least one opening of the first group and a second injection nozzle has the at least one opening of the second group. For each of the two injectors, what has already been said for injectors applies.

Embodiments of the direct-injection spark-ignited internal combustion engine in which the at least two groups each comprise at least two openings or at least one group comprises at least two openings are advantageous.

Embodiments of the direct injection spark-ignited internal combustion engine in which the at least two groups each comprise at least three openings or at least one group comprises at least three openings are advantageous.

Embodiments of the direct injection spark-ignited internal combustion engine in which the at least two groups each comprise at least four openings or at least one group comprises at least four openings are advantageous.

The above embodiments take into account the fact that the number of openings affects the distribution of the introduced fuel in the combustion chamber of the cylinder and thus the mixture formation. The more openings that are provided, the more space the fuel can distribute in the combustion chamber and the more effectively the fuel-air mixture can be homogenized.

Embodiments of the direct-injection spark-ignited internal combustion engine in which each cylinder is equipped with an ignition device for initiating spark ignition are advantageous.

• – zuerst die mindestens eine Öffnung der ersten Gruppe aktiviert wird, wenn der sich auf den unteren Totpunkt zu bewegende Kolben diese mindestens eine Öffnung passiert hat, um in einer ersten Phase des Einspritzvorganges einen zylinderkopfseitigen Bereich des Brennraums mit Kraftstoff zu versorgen, und
• – zeitlich beabstandet die mindestens eine Öffnung der zweiten Gruppe aktiviert wird, um in einer zweiten Phase des Einspritzvorganges einen kolbenseitigen Bereich des Brennraums mit Kraftstoff zu versorgen.

The second sub-task on which the invention is based, namely to disclose a method for operating a spark-ignition internal combustion engine of the type described above, is achieved by a method in which the at least two openings are activated for the purpose of introducing fuel into the combustion chamber as part of an injection process, wherein

• - First, the at least one opening of the first group is activated when the piston to be moved to the bottom dead center has passed this at least one opening to supply a cylinder head side portion of the combustion chamber with fuel in a first phase of the injection process, and
• - Time spaced, the at least one opening of the second group is activated to supply a piston-side portion of the combustion chamber with fuel in a second phase of the injection process.

What has already been said for the internal combustion engine according to the invention also applies to the method according to the invention, which is why reference is generally made at this point to the statements made above with regard to the internal combustion engine.

Embodiments of the method in which the at least two openings are deactivated in order to terminate the injection process are advantageous, wherein the openings are deactivated one after the other in terms of time, such that the at least one opening of the second group and at least the time spaced apart an opening of the first group is deactivated.

In the following the invention is based on an embodiment according to the 1a and 1b described in more detail. Hereby shows:

1a schematically and in cross section the fragment of a cylinder of a first embodiment of the internal combustion engine with a piston in a first position, and

1b schematically and in cross section the in 1a illustrated cylinder with the piston in a second position.

1a shows schematically and in cross section the fragment of a cylinder 1 a first embodiment of the internal combustion engine with a piston 5 in a first position. 1b shows the in 1a illustrated cylinder 1 with the piston 5 in a second position.

The in the 1a and 1b illustrated cylinder 1 has two outlet openings 8th for discharging the exhaust gases via Abgasabführsystem, wherein each exhaust port 8th an exhaust pipe 8a connects and each outlet opening 8th with an exhaust valve 8b is equipped to the outlet opening 8th release in the context of the change of charge. Furthermore, the cylinder has 1 over two inlet openings 7 for supplying the combustion air via the intake system, wherein each intake port 7 a suction line 7a connects and each inlet opening 7 with an inlet valve 7b is equipped to the inlet opening 7 release in the context of the change of charge.

Every cylinder 1 the internal combustion engine comprises a combustion chamber 2 . 2a . 2 B passing through the piston crown 5a a cylinder-associated piston 5 , a the combustion chamber 2 . 2a . 2 B laterally limiting cylinder tube 4 and the cylinder head 3 is trained with. The piston 5 oscillates when operating internal combustion engine along a piston longitudinal axis 5b between a bottom dead center and a top dead center.

Every cylinder 1 the internal combustion engine is in the range of the cylinder tube 4 with an injector 6 for direct introduction of fuel into the combustion chamber 2 . 2a . 2 B fitted. In the present case serves as an injection device 6 an injection nozzle 6a , Which has five openings, which in the context of an injection process for introducing fuel into the combustion chamber 2 . 2a . 2 B activated, ie released.

The openings of the injector 6a are configured and form two groups. The three openings of a first group, that is, the injection jets or fuel jets emerging from these openings 6b , are not on the piston crown 5a of the cylinder-associated piston 5 whereas the two openings of a second group, ie the injection jets or fuel jets emerging from these openings, are aligned 6b , on the piston crown 5a of the cylinder-associated piston 5 are aligned. Reference is made to the in 1a shown position of the piston 5 ie to a position of the piston 5 in which the combustion chamber 2 . 2a . 2 B for the openings of the injection nozzle 6a is accessible and the piston 5 at the same time as close to top dead center as possible.

Two openings of the first group are on the cylinder head 3 aligned on the outlet openings 8th of the cylinder 1 whereas an opening of the first group is perpendicular to the piston longitudinal axis 5b of the cylinder-associated piston 5 is aligned, as in 1a shown.

The two groups of openings are activated offset in time as part of an injection process, d. H. successively released for the introduction of fuel, wherein the openings of the first group are activated earlier than the openings of the second group.

The openings of the first group are activated as soon as the piston to be moved to the bottom dead center 5 these openings has passed to a cylinder head side area in a first phase of the injection process 2a of the combustion chamber 2 . 2a . 2 B to supply with fuel (see 1a ).

Time-spaced, the openings of the second group are activated to a piston-side area in a second phase of the injection process 2 B of the combustion chamber 2 . 2a . 2 B to supply with fuel (see 1b ).

To terminate the injection process, the openings of the injection nozzle 6a separated from the fuel supply system, but not simultaneously, but staggered in time. In this case, the openings of the second group are deactivated earlier than the openings of the first group, ie separated from the fuel supply system.

LIST OF REFERENCE NUMBERS

1

 cylinder

2

 combustion chamber

2a

 Cylinder head side of the combustion chamber

2 B

 Piston side of the combustion chamber

3

 cylinder head

4

 cylinder tube

5

 piston

5a

 piston crown

5b

 piston longitudinal axis

6

 Injector

6a

 injection

6b

 Injection jets, fuel jets

7

 inlet port

7a

 suction

7b

 intake valve

8th

 outlet

8a

 exhaust pipe

8b

 outlet valve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5421301 [0020, 0021, 0022]

Claims (16)

Direct-injection spark-ignited internal combustion engine with at least one cylinder head ( 3 ) comprising at least one cylinder ( 1 ), in which - each cylinder ( 1 ) a combustion chamber ( 2 . 2a . 2 B ), which by a piston head ( 5a ) of a cylinder-associated piston ( 5 ), a combustion chamber ( 2 . 2a . 2 B ) laterally limiting cylinder tube ( 4 ) and the at least one cylinder head ( 3 ) is formed, wherein the piston ( 5 ) along a piston longitudinal axis ( 5b ) is movable between a bottom dead center and a top dead center, and - each cylinder ( 1 ) in a region of the cylinder tube ( 4 ) with an injection device ( 6 ) for direct introduction of fuel into the combustion chamber ( 2 . 2a . 2 B ), which has at least two openings, which in the context of an injection process for the purpose of introducing fuel into the combustion chamber ( 2 . 2a . 2 B ) are activatable, characterized in that - the at least two openings are configured in such a way that they form at least two groups each having at least one opening, - the at least one opening of a first group not on the piston head ( 5a ) of the cylinder-associated piston ( 5 ), whereas at least one opening of a second group is directed towards the piston head ( 5a ) of the cylinder-associated piston ( 5 ), wherein reference is made to a position of the piston ( 5 ), in which the combustion chamber ( 2 . 2a . 2 B ) is accessible for the at least two openings and the piston ( 5 ) is located as close as possible to top dead center, and - the at least two groups each having at least one opening in the context of an injection process are activated offset in time, wherein the at least one opening of the first group is activated earlier than the at least one opening of the second group. Direct injection spark-ignited internal combustion engine according to claim 1, characterized in that the at least two groups each having at least one opening in the context of an injection process can be deactivated offset in time, wherein the at least one opening of the second group is deactivated earlier than the at least one opening of the first group. Direct injection spark-ignited internal combustion engine according to claim 1 or 2, characterized in that at least one opening of the first group on the at least one cylinder head ( 3 ) is aligned. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that at least one opening of the first group perpendicular to the piston longitudinal axis ( 5b ) of the cylinder-associated piston ( 5 ) is aligned. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that at least one opening of the second group perpendicular to the piston longitudinal axis ( 5b ) of the cylinder-associated piston ( 5 ) is aligned. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that the injection device ( 6 ) of each cylinder ( 1 ) perpendicular to the piston longitudinal axis ( 5b ) of the cylinder-associated piston ( 5 ) is aligned. Direct-injection spark-ignition internal combustion engine according to one of claims 1 to 5, characterized in that the injection device ( 6 ) of each cylinder ( 1 ) to the piston longitudinal axis ( 5b ) of the cylinder-associated piston ( 5 ) is inclined. Direct injection spark-ignited internal combustion engine according to claim 7, characterized in that the injection device ( 6 ) of each cylinder ( 1 ) to the piston longitudinal axis ( 5b ) of the cylinder-associated piston ( 5 ) and on the at least one cylinder head ( 3 ) is aligned. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that the injection device ( 6 ) has a movable closure body, the positively controlled in the context of an injection process, the at least two openings for the purpose of introducing fuel into the combustion chamber ( 2 . 2a . 2 B ) connects and releases with a fuel supply system, wherein the closure body releases the openings in succession with a time delay, in such a way that at a piston to be moved from top dead center to bottom dead center (FIG. 5 ) First, the at least one opening of the first group and spaced in time, the at least one opening of the second group is released. Direct injection spark-ignited internal combustion engine according to claim 9, characterized in that the movable closure body deactivates the at least two openings in the context of an injection process for the purpose of ending the injection process, wherein the closure body, the openings temporally offset successively deactivated, in such a way that at from the bottom dead center on the top dead center to moving piston ( 5 ) First, the at least one opening of the second group and spaced in time, the at least one opening of the first group is deactivated. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that the injection device ( 6 ) an injection nozzle ( 6a ), which has the at least two openings. Direct-injection spark-ignition internal combustion engine according to one of claims 1 to 5, characterized in that the injection device ( 6 ) comprises two injection nozzles, wherein a first injection nozzle having at least one opening of the first group and a second injection nozzle having at least one opening of the second group. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that the at least two groups each comprise at least two openings. Direct injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that the at least two groups each comprise at least three openings. Method for operating a direct-injection spark-ignited internal combustion engine according to one of the preceding claims, characterized in that, as part of an injection process, the at least two openings for the purpose of introducing fuel into the combustion chamber ( 2 . 2a . 2 B ) are activated, wherein - first the at least one opening of the first group is activated when the piston to be moved to the bottom dead center ( 5 ) has passed through at least one opening in order, in a first phase of the injection process, to open a cylinder-head-side region ( 2a ) of the combustion chamber ( 2 . 2a . 2 B ) are fueled, and - spaced in time, the at least one opening of the second group is activated in order in a second phase of the injection process, a piston-side area ( 2 B ) of the combustion chamber ( 2 . 2a . 2 B ) to provide fuel. A method according to claim 15, characterized in that in the context of an injection process, the at least two openings are deactivated for the purpose of terminating the injection process, wherein the openings are deactivated offset in time successively, such that first the at least one opening of the second group and temporally spaced at least one opening of the first group is deactivated.

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