DE102006008567A1 - Combustion chamber arrangement of fuel-injected diesel engine has concave contour of piston bowl formed so that first and second fuels jets are directed onto each other and at least partially flow back in direction of central injector - Google Patents

Abstract

The The present invention relates to a combustion chamber arrangement of a direct injection Diesel engine by means of an air-distributing combustion process with a spray-guided Mixture formation comprising a piston (2) and at least one Central injector (4), with which at least a first (5) and a second jet (6) from in each case one outlet opening of the central injector (4) are injectable into a combustion chamber and which of a piston surface (23) the piston (2) is opposite, the piston surface (23) for warranty an improved fuel distribution in the combustion chamber at least a trough (7), which on one to a circumference of the piston adjacent side (10) at least one from the direction of the central injector (4) concave (11) and a subsequent convex trough contour (12), wherein through the convex trough structure (12) has an undercut (24) of the trough (7) is formed, wherein a first impact area (15) of the first beam (5) between a vertex (14) of the convex Trough contour (12) and the concave trough contour (11) provided is and a second, different from the first impact area (16) one of the convex mold contour (12) remote edge of the concave Trough contour (11) is aligned, wherein the concave trough contour (11) is shaped so that the first (5) and second beam (6) are articulated to each other and at least partially towards the central injector (4) flow back.

Description

The The present invention relates to a combustion chamber arrangement of a direct injection Diesel engine with an air-distributing combustion process with spray-guided mixture formation.

One air-distributing combustion process with sprayed mixture formation is at Internal combustion engines used to a combustion process in terms of performance of consumption and in terms of avoiding unnecessary To improve emissions.

task The present invention is an improved fuel distribution in the combustion chamber.

These Task is solved with a combustion chamber arrangement having the features of claim 1, a piston of a combustion chamber arrangement with the features of the claim 15, an internal combustion engine having the features of claim 16 and a method of injecting fuel into a combustion chamber with the features of claim 17. Advantageous embodiments and further developments are specified in the respective dependent claims.

A combustion chamber arrangement according to the invention a direct-injection diesel engine with an air-led combustion process with spray-guided Gemsichbildung comprises a piston and at least one central injector, with which at least a first and a second beam of each an outlet opening of the central injector are injectable into a combustion chamber and which a piston surface opposite the piston, the piston surface has at least one trough, which on one to a circumference the piston adjacent side at least one from a viewing direction of the central injector concave and a subsequent convex Having trough contour, wherein by the convex trough contour a Undercut of the trough is formed, with a first impact area of the first beam between a vertex of the convex trough contour and the concave trough contour is provided and a second, from first different impact area on one of the convex trough contour lying remote edge of the concave depression contour, wherein the concave Trough contour is shaped so that the first and second beam collided and at least partially towards the central injector flow back.

in the The following is an injector under the concept of the central injector to be understood essentially in the cylinder axis with his Symmetryeachse is arranged, wherein a spray pattern substantially has a rotational symmetry about the injector axis. this includes but also fall injectors that are rotationally symmetric Have spray pattern and for that in the middle of a cylinder head.

According to one Continuing education is provided that the second, different from the first Impact area on one of the convex trough contour remote Edge of the concave depression contour approximately tangential to the second Beam is aligned.

The concave trough contour is in a cross section of the piston, for example designed in a circular arc. A length The circular arc corresponds approximately to the length of a semicircle. The Length can but also be provided less and, for example, approximately the length a third circle. In another embodiment can the length also the length of a semicircle and, for example, approximately up to a length of a two-thirds circle be designed. Instead of a pure circular shape can of course also a be provided elliptical or distorted circular shape. Generally has the concave trough contour in about a trough-shaped cross-sectional line. The concave depression contour is preferably starting from a piston surface below the convex trough contour.

The Convex trough contour corresponds in shape approximately to the above presented forms of a concave contour, with different shapes can be provided by convex and concave contour. The however convex contour is from the direction of view of the central injector in contrast to the concave trough contour emerging from the trough. Concave and convex bowl contour can be different in particular designed large be, wherein the convex mold contour preferably at least slightly smaller as the concave trough contour is configured. In a cross section a trough form concave and convex trough contour thus approximately an s-shaped one or mirrored on a longitudinal axis s-shaped Edge contour. Preferably, this contour is arranged so obliquely, that a longitudinal axis the s-shape approximately perpendicular to a line of sight of the central injector is aligned.

The Convex and the concave depression contour are in particular designed such that they at least over a solid angle section related to an origin, which in Central injector is located, extending. The concave or the convex Trough contour can in particular over a partial circumference of the piston be extended on an inner edge.

Based is in a viewing direction perpendicular to the piston surface in the hollow due to the s-shaped Edge contour thus formed an undercut.

A trough height or trough depth of the trough contours is for example approximately one Tenth of a piston diameter. In embodiments, ratios between one twentieth and one fifth.

Of the The vertex of the central injector is from the direction of the central injector Are defined. In particular, a point is defined as a vertex the sliding of a fuel jet impinging thereon equally can be done in both directions and with only a slight displacement of it would be directed in only one of the two directions.

first and second fuel jet are preferably under a high Injection pressure injected into the combustion chamber. For example, pressures from more than one kilobar, preferably more than 1500 bar used. In particular, allows the high injection pressure is a beam forming with a preferably low expansion angle. An impact area of a fuel jet is preferably approximately punctiform. The central injector is in particular adjusted so that from this fuel jets injected into the combustion chamber substantially respectively recurring in separate but approximately constant impact areas arise in accordance with the same injection. An injection time is in the top dead center, preferably between limits so selected that an impact in the respective impact area or their closer Environment is ensured.

Accordingly are for the first and the second beam a first and a second of which different Impact area provided. The first impact area of the first In particular, the ray is between a vertex of the convex Trough contour and the concave trough contour provided that a impinging fuel jet in the direction of the concave depression contour derives or is diverted. In addition to a diversion can in particular be provided that the impinging fuel jet at least partially atomized becomes.

Of the second impingement of the second beam is in particular so designed that the second beam towards the lowest point the trough contour is steered. First and second beam meet in particular, in a remote from the central injector Part of the concave depression contour. A point of clash lies for example approximately in the center in the concave depression contour. The impact areas are preferably designed so that in Essentially a deflection of the rays through the trough contours with only a slight adhesion and thus wetting derselbigen he follows.

Preferably is next to an additional atomization one Propagation of the fuel in one between the central injector and reaches the trough contour located area of the combustion chamber. Of Furthermore, a distribution of the fuel is preferred significantly improved and in particular its surface area increased compared to conventional Einspritzstrahl- / well geometries.

According to one Embodiment is provided that an angle of the beams to each other when hitting each other is less than 180 °. In particular, by an angle smaller than 180 ° good compromise between partial atomization and partial backflow towards of the central injector.

Regarding the Auftreffbereiches is provided in a first variant that the first impingement area is aligned approximately tangentially to the first beam is. In particular, atomization of the first beam is added a hitting at least largely reduced.

In In another variant, the first impact area is at an angle below 90 °, preferably below 45 ° to aligned first beam. In particular, by setting an angle between 0 and 45 ° Degree of atomization upon impact of the first beam on the first impact area set. The impact area can be designed in this way in particular be that even with non-compliance of tolerances or change the spray holes due to deposits within an area which clearly exceeds one Beam diameter is extended, at a prescribed angle is aligned.

According to one Further development, the concave depression contour approximately in the middle Lip up. Preferably, this results in an impact point of the rays more precisely. In particular, the location of the beam deflection or jet atomization largely independent from changed nozzle characteristics for example, as a result of a change in the injection holes due be set by deposits.

alternative or additionally it is provided that the trough at the first and / or second impact area has a lip. Preferably, the lip serves a broadening of the impact area. In particular, this also allows one Reduction of the influence of tolerances or changes the spray holes.

According to one embodiment, the central injector has at least two rows of holes for generating in each case a fan beam, wherein the first and the second beam are each associated with a fan beam. Each fan beam points in particular a large number of individual beams. Accordingly, each of these individual jets is assigned in each case one landing surface. An operation of a deflection is analogous to the embodiments described above concerning the first and the second beam.

Preferably are the fan-beams each aligned in at least one circular sector to the central injector. Trough geometry and / or beam fan geometry are particular within this circle sector at least approximately rotationally symmetric arranged relative to an axis of the central injector.

Regarding the Row of holes is provided in a further embodiment that this one different hole geometry, especially a different one Hole diameter, a different hole conicity and / or Have rounding. Thereby can For example, different jet opening angles within the different beams or fan beams can be achieved. Preferably can be based on an opening angle or Widening angle of a beam, a sputtering process on impact be influenced on the trough.

The Trough geometry is according to a Continuing adapted to a hole diameter of the central injector. In particular, the well geometry is set so that even under consideration a tolerance or a change a spray hole due to deposits from the hole in the jet injected jet within the impact area impinges in the trough contour. Preferably by a sputtering and / or Back flow characteristics the relevant beam of tolerances or deposits impaired.

According to one Further development of the combustion chamber arrangement is provided that the larger of the angle between a stroke direction of the piston and the first jet as well between the stroke direction of the piston and the second jet greater than 80 ° and preferably greater than 85 ° is. In other words, at least one of the two rays becomes approximately perpendicular with an angle greater than 80 ° and preferably greater than 85 ° injected into the trough on a piston tread associated with the piston. Thus, in particular a flat beam guide is at least one of the two Given rays.

According to one Another embodiment of the combustion chamber is provided that a Combustor ceiling a roof pitch greater than about 80 ° and preferred of more than 85 ° to having a stroke direction of the piston. This is especially true provided a flat design of the combustion chamber.

The The invention further relates to a combustion chamber arrangement according to the aforementioned embodiments.

Farther The invention relates to an internal combustion engine, which a Combustion chamber arrangement according to a comprising the embodiments described above.

Finally, concerns the invention a method for injecting fuel into a Combustion chamber of a direct-injection diesel engine with an air-distributing Combustion process with spray-guided Mixture formation, wherein a piston surface bounding the combustion chamber at least a trough, which on one to a circumference of the piston adjacent side at least one from the direction of the central injector concave and an adjoining having convex trough contour, wherein by the convex trough contour an undercut of the trough is formed, wherein at least a first Fuel jet is injected onto the convex trough contour and at least one second fuel jet on one of the convex Tray contour remote edge of the concave depression contour injected is, so that the first and the second fuel jet of the piston surface be deflected so that they are in the concave trough contour or meet the combustion chamber and at least partially into one located between the concave depression contour and the central injector Back flow of the combustion chamber and be atomized.

Of the for the Process used combustion chamber is in particular a combustion chamber a combustion chamber arrangement according to a the embodiments shown above.

According to one Further training is provided that during a movement of the piston at least the first and the second fuel jet offset in time injected into each other. This can be relative to each other the start of injection, the end of injection and / or the duration of injection to be different. Also can Pre and post injections are possible.

Especially takes place when the first and / or the second beam impinge a partial atomization desselbigen. A non-atomized fuel is thereby preferably deflected by the trough contour so that a atomization this fuel part only after a meeting of the two Fuel blasting takes place.

According to one Embodiment make the first and / or the second beam approximately tangential on the trough.

According to one embodiment the first and the second beam are deflected so that a change in direction between entering the trough and exiting the trough Each greater than 160 ° and preferably greater than 180 ° is. As emerging from the trough rays are in particular rays to understand each other immediately before a meeting, if the trough contour to it. is designed accordingly. Especially if the rays meet within the trough, than Beam direction of the exiting rays a middle direction to provide the partial beams generated after a clash.

first and second beam form, for example, an opening angle of about 25 °. An in Direction of the central injector jet flowing back from the concave trough has thus experienced a directional deflection of about 193 °.

According to one another embodiment additionally to the first beam a plurality of neighboring beams in a first Jet fans and additionally to the second beam a plurality of neighboring beams in a second ray fan injected into the trough.

The ray fan are in each case in each case in at least one circular sector set to central injector. A location of the circular sector is in particular to an inlet and / or adapted to an outlet channel. For example, the fan beams are in set two or more circle sectors around the central injector.

In a development is a position of the first and / or second beam determined as a function of the piston stroke. In particular, the first and / or tracked the second beam. For example, a tracking by a stroke adjustment in, for example, a register nozzle, a Varionozzle or a Vario slot nozzle respectively. Preferably, a tracking takes place together with a Adjustment of an injection quantity. Preferably, a tracking causes that with a moving piston a jet always on the same landing surface of the each beam impinges. Preferably, this allows one of a Piston position independent atomization of the Fuel jets. A tracking For example, the rays can also be obtained by using different ones be provided at different angles arranged nozzles, which be used selectively depending on the piston position. In a variant can Depending on the piston stroke also different impact areas may be provided.

In In one embodiment, a deflection of the first and / or second Beam supported by at least one lip in the trough. Preferably will be through the support through the lip a direction of emerging from the trough or atomized Beam, in particular, independently adjusted by tolerances of the incoming rays. Preferably a lip facilitates adjustment of the exiting or atomized jet from the well at least largely independent of a piston stroke.

A Swirl number of a charge movement is according to an embodiment between 0 and 3. A swirl number is defined in particular as the ratio of Rotational velocity component and lateral velocity component in the direction of a piston stroke.

According to one Continuing education will be for one row of holes of the central injector each have an injection rate established. In particular, you can first and second beam or the associated neighboring beams of the corresponding ray fan be set differently strong. Preferably is through a different strong setting of the beams to each other In some way a direction of the atomized Beam independent set of concave and convex trough contour, or to a Middle position varies.

alternative or additionally can be provided that for one row of holes of the central injector each have an injection pressure is determined. Again, preferably at least one central position the jet emerging from the trough within certain limits Influencing its direction are made.

in the The invention will be described in more detail below with reference to the drawings explained. However, this is not on the feature combinations shown there limited. Much more can each in the figures as well as in the description including the description of the figures contained features to trainings combined.

It demonstrate:

1 a first embodiment of a combustion chamber arrangement in a schematic longitudinal section,

2 a second embodiment in a schematic longitudinal section, and

3 a third embodiment in a schematic longitudinal section.

1 shows a first embodiment 1 a combustion chamber arrangement in a schematic longitudinal section. Shown is a half of a piston 2 , which along a central axis 3 centered to a central injector shown in half 4 is aligned. The central injector 4 has two injection ports not shown in detail. This is a first beam 5 and a second beam 6 into a hollow 7 of the piston 2 injected. The hollow 7 has a trough contour 8th on which one on a scale 9 of the piston 2 adjacent side 10 a concave one 11 and a convex trough contour 12 having. The concave 11 and the convex trough contour 12 are at least from the direction of the central injector 4 concave or convex. concave 11 and convex trough contour 12 thus form an approximately mirrored s-shaped Muldenkonturabschnitt 13 ,

The first ray 5 is aligned so that it is between a vertex 14 the convex trough contour 12 and the concave trough contour 11 in a first impact area 15 incident. The first ray 5 In this case, it meets approximately at an angle of 45 ° to a surface of the convex mold contour 12 on. The second ray 6 meets in a second impact area 16 at one of the convex trough contour 12 distant edge 17 on the concave trough contour 11 on. The edge 17 the concave trough contour 11 is approximately tangential to the second beam 6 aligned. As a result of a hitting the first 15 and the second impact area 16 become first 5 and second beam 6 in the concave depression contour 11 deflected, leaving a first deflected beam 18 and a second deflected beam 19 in the concave depression contour 11 meet. This is an outgoing beam 20 formed, which is substantially in the direction of the central injector 4 from the concave depression contour 11 is moved. In particular, an atomization of the exiting jet takes place 20 and preferably a partial Zer atomization of the first deflected beam 18 and the second deflected beam 19 at a meeting.

Furthermore, preferably a partial atomization of the first beam takes place 5 when hitting the first impact area 15 ,

in the Following are equivalent elements with the same reference numerals Mistake.

2 shows a second embodiment 21 a combustion chamber arrangement in a schematic longitudinal section. This embodiment basically corresponds to the first embodiment 1 However, where one of them different trough contour 8th is provided. A hollow 7 a piston 2 is designed so that in a direction of view of a Zentralinjektors 4 concave trough contour 11 about the middle of a lip 22 is arranged. Adjacent to the concave depression contour 11 is a convex trough contour 12 provided, whose radius compared to in the in 1 However, shown well contour is designed much smaller. Perpendicular to a surface 23 of the piston 2 considered forms the convex trough contour 12 an undercut 24 , One from the central injector 4 into the hollow 7 injected first ray 5 meets on a first impact area 15 between a vertex 14 the convex trough contour 12 and the concave trough contour 11 on. The first ray 5 is approximately tangential to the first impact area 15 designed. Furthermore, a second beam 6 from the central injector 4 into the hollow 7 injected. This second ray 6 meets in a second impact area 16 on the concave trough contour 11 on. The second ray 6 is again approximately tangential to the second impact area 16 aligned. When hitting the impact areas 15 . 16 become the first ray 5 and the second beam 6 correspondingly in the concave depression contour 11 diverted. This is through the first deflected beam 18 and the second deflected beam 19 indicated schematically. first 18 and second deflected beam 19 meet under an impact angle 25 each other. This impact angle 25 is about 45 °. This is in the present case significantly smaller than 180 °, so that a resulting emergent beam 20 a larger impulse towards the central injector 4 imprinted than would be the case with a hitting below 180 °. In addition to the exiting beam 20 an atomization of the first, not shown in detail, takes place 18 and the second deflected beam 19 ,

3 shows a third embodiment 26 a combustion chamber arrangement in a schematic longitudinal section. This third embodiment 26 is essentially the ready in 1 shown first embodiment 1 , A combustion chamber ceiling 27 has a roof pitch 28 of about 10 ° relative to a surface 23 a piston 2 on. A first ray 5 which is from a central injector 4 into a hollow 7 of the piston 2 is injected, has a beam angle 29 of about 80 ° relative to a central axis 3 of the piston 2 on. Accordingly, the first beam runs 5 at an angle of about 10 ° to the piston surface 23 , In an embodiment, not shown, an angle can be provided below 5 °. Accordingly, in a configuration, not shown, a roof pitch 28 less than 5 ° relative to the piston surface 23 be provided.

Furthermore, the first beam 5 and a second beam 6 not shown neighbor beams associated, which in a likewise not shown fan of rays around the central injector 4 are arranged. The fan beams extend over at least one circular sector, viewed in a viewing direction parallel to a central axis 3 of the piston 2 , The central injector 4 has in each case a row of holes, which is not shown in detail, for the first and the second fan beams on.

In particular, different hole geometries, in particular different hole conicity and / or rounding, can be provided for the two different rows of holes. For example, the first ray 5 and the second beam 6 , which is not shown in detail, expanded differently. Accordingly, a first impact area increases 15 and a second impact area 16 , Similarly, becoming an effective first impact area 15 and an effective second impact area 16 increased, for example, if, as a result of deposits, the holes of the central injector subject to changes. Similarly, an increase in the impact areas 15 . 16 present when the holes of the central injector 4 Subject to variations in diameter or conicity.

Claims (26)

Combustion chamber arrangement of a direct-injection diesel engine for use with an air-distributing combustion process with spray-guided mixture formation, comprising a piston ( 2 ) and at least one central injector ( 4 ), with which at least one first ( 5 ) and a second beam ( 6 ) from in each case one outlet opening of the central injector ( 4 ) are injectable into a combustion chamber and which of a piston surface ( 23 ) of the piston ( 2 ), wherein the piston surface ( 23 ) at least one trough ( 7 ), which on one to one extent ( 9 ) of the piston ( 2 ) adjacent side ( 10 ) at least one from the direction of view of the central injector ( 4 ) concave ( 11 ) and a subsequent convex trough contour ( 12 ), wherein by the convex trough contour ( 12 ) an undercut ( 24 ) of the trough ( 7 ), wherein a first impact area ( 15 ) of the first beam ( 5 ) between a vertex ( 14 ) of the convex mold contour ( 12 ) and the concave depression contour ( 11 ) and a second, different from the first impact area ( 16 ) on one of the convex mold contours ( 11 ) remote edge ( 17 ) of the concave depression contour, wherein the concave depression contour ( 11 ) is shaped so that the first ( 5 ) and the second beam ( 6 ) and at least partially in the direction of the central injector ( 4 ) flow back. Combustion chamber arrangement according to claim 1, characterized in that the second, different from the first impact area ( 16 ) on one of the convex mold contours ( 11 ) remote edge ( 17 ) of the concave depression contour ( 11 ) approximately tangential to the second beam ( 6 ) is aligned. Combustion chamber arrangement according to claim 1 or 2, characterized in that an angle ( 25 ) of the beams ( 5 ; 6 ) is less than 180 ° to each other when hitting each other. Combustion chamber arrangement according to claim 1, 2 or 3, characterized in that the first impact area ( 15 ) approximately tangential to the first beam ( 5 ) is aligned. Combustion chamber arrangement according to one of the preceding claims, characterized in that the first impingement area ( 15 ) is oriented at an angle of less than 45 ° to the first beam. Combustion chamber arrangement according to one of the preceding claims, characterized in that the concave depression contour ( 11 ) in about the middle of a lip ( 22 ) having. Combustion chamber arrangement according to one of the preceding claims, characterized in that the trough ( 7 ) at first ( 15 ) and / or second impact area ( 16 ) has a lip. Combustion chamber arrangement according to one of the preceding claims, characterized in that a position of the first ( 5 ) and / or the second beam ( 6 ) is set as a function of a piston stroke. Combustion chamber arrangement according to one of the preceding claims, characterized in that the central injector ( 4 ) has at least two rows of holes for generating in each case a fan beam, wherein the first ( 5 ) and the second beam ( 6 ) are each associated with a fan beam. Combustion chamber arrangement according to claim 9, characterized in that the fan beams in each case in at least one circular sector to the central injector ( 4 ) are aligned. Combustion chamber arrangement according to one of claims 9 or 10, characterized in that the rows of holes a different Hole geometry, in particular a different Lochkonizität and / or Hole rounding, exhibit. Combustion chamber arrangement according to one of the preceding claims, characterized in that a depression geometry to a hole diameter of the central injector ( 4 ) is adjusted. Combustion chamber arrangement according to one of the preceding claims, characterized in that the greater of the angles between a stroke direction ( 3 ) of the piston ( 2 ) and the first beam and between the stroke direction ( 3 ) of the piston ( 2 ) and the second beam is greater than 80 ° and preferably greater than 85 °. Combustion chamber arrangement according to one of the preceding claims, characterized in that a combustion chamber ceiling ( 27 ) a roof pitch ( 28 ) of more than about 80 ° and preferably of more than 85 ° to a stroke direction ( 3 ) of the piston ( 3 ) having. Piston of a combustion chamber arrangement according to one of claims 1 to 14th Internal combustion engine comprising a combustion chamber arrangement according to one of the claims 1 to 14. Method for injecting fuel into a combustion chamber of a direct-injection diesel engine by means of an air-distributing combustion method with spray-guided mixture formation, wherein a piston surface bounding the combustion chamber ( 23 ) at least one trough ( 7 ), which on one to one extent ( 9 ) of the piston ( 2 ) adjacent side ( 10 ) at least one from the direction of view of the central injector ( 4 ) concave ( 11 ) and a subsequent convex trough contour ( 12 ), wherein by the convex trough contour ( 12 ) an undercut ( 24 ) of the trough ( 7 ), wherein at least one first fuel jet ( 5 ) on the convex mold contour ( 12 ) is injected and at least a second fuel jet ( 6 ) on one of the convex trough contour ( 12 ) remote edge ( 17 ) of the concave depression contour ( 11 ) is injected so that the first ( 5 ) and the second fuel jet ( 6 ) are deflected from the piston surface so that they in the concave depression contour ( 11 ) or the combustion chamber and at least partially into one between the concave depression contour ( 11 ) and the central injector ( 4 ) located back region of the combustion chamber and are atomized. Method according to claim 17, characterized in that the first ( 5 ) and / or the second beam ( 6 ) impinge approximately tangentially on the trough. Method according to claim 17 or 18, characterized in that the first ( 5 ) and the second beam ( 6 ) are deflected so that a change of direction between entering into the trough ( 5 ; 6 ) and emerging from the trough beams ( 20 ) is greater than 160 ° and preferably greater than 180 °. Method according to one of claims 17 to 19, characterized in that in addition to the first beam ( 5 ) a plurality of neighbor beams in a first beam fan and in addition to the second beam ( 6 ) a plurality of neighbor beams in a second fan beam are injected into the trough. A method according to claim 20, characterized in that the fan beams in each case in at least one circular sector to the central injector ( 4 ). Method according to one of the preceding claims 17 to 21, characterized in that a position of the first ( 5 ) and / or second beam ( 6 ) is determined as a function of a piston stroke. Method according to one of the preceding claims 17 to 22, characterized in that a deflection of the first ( 5 ) and / or second beam ( 6 ) by at least one lip ( 22 ) is supported in the trough. Method according to one of the preceding claims 17 to 23, characterized in that a swirl number of a charge movement between 0 and 3. Method according to one of the preceding claims 17 to 24, characterized in that for each row of holes of the central injector ( 4 ) In each case an injection rate is set. Method according to one of claims 17 to 25, characterized in that for each row of holes of the central injector ( 4 ) In each case an injection pressure is set.