Ignition and combustion in an internal combustion engine

The invention relates to an internal combustion engine with direct fuel injection and Spark ignition, wherein the combustion chamber is formed by a cylinder block, a cylinder head And a piston, a trough is formed in the piston surface, and the Fuel can be injected from an injection nozzle in the direction of the trough and can be fed via a Spark ignition device, and wherein the trough is positioned in the piston And is dimensioned or dimensioned in such a way that the spark ignition device or A carrier of the spark ignition device already at least before the ignition point is reached With its free end immersed in the hollow with little play and on reaching Of the top dead center of the piston is dipped into the trough with little play And at the same time substantially filling out the trough.

The invention is based on a prior art as described in DE-A-31 29 869 Is known. From this publication, an externally ignited internal combustion engine is in concrete terms With charge coating. For this internal combustion engine, It is essential that the spark ignition device and the injection nozzle are integrally connected thereto A component, and that the spark ignition device and the injection nozzle Is integrally formed, namely assigned to the valve Is.

The known internal combustion engine or the technology implemented there is in practice But problematic, because the injection via a moving component - the valve -. The injection of the fuel to the injection nozzle is to avoid Of leakage problems or to ensure the necessary tightness of the System is extremely complex and therefore cost-intensive. Furthermore, it is extreme It is problematic to carry out the ignition via a movable part - the valve - Since there is always the risk of short circuits or shunts.

Starting from the state of the art known from DE-A-31 29 869, It is therefore an object of the present invention to provide an internal combustion engine of the Generic species in such a way that in the simplest form Construction the problems or disadvantages occurring in the prior art Are largely avoided.

The internal combustion engine according to the invention achieves the above object The features of the patent claim 1. According to this, the generic internal combustion engine Characterized in that the radio ignition device or the carrier The spark ignition device and the injection nozzle are independent of each other Components are assigned to the cylinder block in a stationary manner, and in that the injection nozzle is arranged in such a way Is arranged and aligned in such a way that the injection jet axis is aligned with the piston axis Is angled.

According to the invention it has been recognized that a reliable function of the claimed invention Internal combustion engine is possible when the spark ignition device and the injection nozzle Are stationary. To this extent, of the generic status Of the technique, whereby both the spark ignition device and the Injecting nozzle are associated with a movable component, namely the valve. Of Further, in the manner according to the invention, also from the state of the art Manifested combination of spark igniter and injector. In contrast to the prior art, A separate spark ignition device and a separate spark ignition device Injection nozzle. Both components are designed independently of one another And arranging the construction of the claimed internal combustion engine Considerably simplified.

While the spark ignition device is designed and arranged in such a way that, Before reaching the ignition time at least with its free end into the Trough with a small clearance and, when the top dead center of the Piston is immersed in the trough with little play and at the same time the trough at least Largely fills, the injection nozzle is arranged and aligned, That the resulting injection-jet axis is the main axis of the piston movement And thus angled to the piston axis. In this respect, That in the course of the piston movement, at least one momentarily occurs in the trough Directional injection jet axis, wherein, during the piston movement, At least briefly the projection of the injection beam cone onto the piston and the At least partly cover the trough.

Although the injection jet axis is located away from the piston axis, this is at least sufficient Partial overlap in order to supply sufficient fuel in the trough. In contrast to the internal combustion engine known from the prior art Has been further recognized to the effect that an enrichment of fuel in The trough is also possible in the context of such a concrete arrangement without That is, a constraint for the coaxial arrangement of spark ignition means and Injector. On the contrary, the injection nozzle can be located away from the spark ignition device , Whereby an alignment with the trough in the invention is possible Is necessary but also sufficient.

With the internal combustion engine according to the invention, a simple construction is at all events Within the combustion chamber, according to which the spark ignition device And the injector are realized as separate stationary elements, wherein The injection nozzle is arranged away from the piston axis and correspondingly aligned And according to which a sufficient supply of fuel to the trough is nevertheless provided Is possible without the spark ignition device and the injection nozzle being movable And / or coaxially with one another.

The provision of special radio ignition devices, in particular pre-chamber radio ignition devices, Favors on the one hand a particularly far-reaching one Mixture enrichment at the ignition point and, on the other hand, improved reproducibility The mixture composition and homogenization in the range Of ignition. At the same time, it is possible by the pre-chamber ignition device A particularly rapid and uniform combustion of a Especially lean fuel-air mixture with low pollutant emissions Can be achieved.

Special advantages with regard to fuel treatment at low temperature The piston surface area and / or the fuel / air mixture are obtained if, for example, A prechamber spark ignition device or prechamber spark plug is used becomes. In this case, the ignition point is located within an area covered by a play Shaped substantially cylindrical antechamber. When immersing the Anterior chamber in the hollow develop between this and the outer wall of the Prechamber very high flow velocities. Therefore, Surface of the trough before dipping the antechamber still remaining remain Liquid fuel and atomized.

A further advantage of the pre-chamber spark ignition device is that, according to FIG Ignition of the mixture in the chamber Which spread radially from the prechamber into the further combustion chamber. This process results in a particularly even and rapid combustion Of the remaining, very lean fuel-air mixture and low NOx emissions.

If at least a part of the directly injected fuel is applied to the surface of the In the piston and / or the surroundings thereof on the piston base And / or in the form of a fuel - enriched mixture into the trough and / or And after the radio ignition device has been immersed in the The expansion of the combustion gases produced by the combustion Hot gases in connection with a so - called squeeze flow between piston and piston Cylinder head and / or spark ignition device to a substantially piston-bottomed Flow of hot combustion gases into the further combustion chamber.

In this case, the fuel direct injection is effected during the intake process And / or during the compression process of the internal combustion engine. In In either case, a portion of the fuel will be substantially toward the well Injected. In order to achieve this, it is particularly advantageous if the injection beam axis At a particularly small angle to the main axis of the combustion chamber, Ie as steeply as possible to the central region of the piston bottom. The Requires a close proximity of spark igniter and injection valve.

In an alternative embodiment, when approaching the TDC position of FIG A prechamber is formed from the trough which is connected via a circular ring-shaped piston In the radial direction, to the main combustion chamber. At the A further variant with precombustion-spark ignition device is provided via Circular overflow channels has a substantially star-shaped radial flame propagation From the antechamber. Also a combination of both before Mentioned variants is possible.

Due to the immersion of a particularly advantageous pre-chamber spark ignition device An intensive, annular flow is additionally counteracted into the piston recess Of the above, in the upper region of the combustion chamber to the center of the combustion chamber Combustion flow directed, resulting in a rapid mixing of the Fuel-rich mixture from the trough and the vicinity of the pre-chamber spark ignition device With air or lean mixture. Thanks to the use A suitable or special spark ignition device, in particular a pre-chamber radio ignition device, It is possible, specifically and with little effort, Intensive flow of hot gases, mainly flowing uniformly and radially In the narrow region of the trough.

For spark ignition of the mixture in the trough, a conventional spark plug with At least one finger-shaped ground electrode. To ignition However, other embodiments are also conceivable here, such as, for example, an arrangement, In which the ground electrode is inserted in a pin-shaped manner into the piston. In this variant For example, the influence of the Ground electrode. An ignition spark igniter can, of course, also be used for ignition Can be used in which the ignition spark occurs The ceramic stone foot of a spark plug.

On the one hand, the largest possible quantity of the inside the trough Fuel during the compression process into the prechamber spark igniter , The overflow ducts in the front region can be designed as a diffuser, Ie, expanding toward the free end. The diffuser shape causes At the same time that when the burnt hot gases are discharged from the prechamber spark igniter A rapid fanning of the torch beams and thus An early approach of the hot gases to the piston bottom takes place. Since the Maximum discharge speed of the hot combustion gases from the antechamber and The beam thickness is significantly greater than that of the outflow from the annular channel Gases, becomes the core area of ​​the torch beams when they enter the combustion chamber Little influence.

The position and inclination of the transfer channels opposite the piston bottom is thus determined That on the one hand a good evaporation of the fuel results, and on the other hand The heat transfer to the piston and thus the losses remain small.

In order to provide as large a portion as possible of the fuel within the trough in The pre-chamber spark ignition device, and at the same time Of the outflow process of the hot combustion gases Troughs, and in particular the bottom region, are connection bores Or overflow ducts between the end face of the pre-chamber spark ignition device And the other transfer channels the filling of the pre-chamber fuel-air mixture from the bottom portion Of the trough is sucked by a jet pumping action. Through the same Effect occurs when the hot combustion gases flow out through the overflow ducts Penetration of these gases into the bottom region of the trough.

A particularly well - adapted top - to - bottom flow of hot combustion gases in the The environment of the trough is achieved by the fact that, during the immersion process, Prechamber in the trough the generated torch beams on the inner wall of the trough And in the annular gap between the pre-chamber outer wall and the depression wall Flow, which, after the hot gases have escaped from the annular gap A surface of the piston body or of the outer large trough or Of the expanded region of the trough, is formed from hot combustion gases cause.

In order to reliably control the thermal loading of the piston in this case, To line the trough with a sleeve of high-heat-resistant material. A Liner of the well is also in an arrangement other than the one previously discussed applicable.

There are now various possibilities of incorporating the teachings of the present invention in Advantageously and further develop. On the one hand, Subordinate claims, on the other hand to the The following explanation of exemplary embodiments of the invention with reference to FIGS Drawings. In connection with the explanation of the preferred embodiment Embodiments of the invention with reference to the drawing are also made in general Preferred embodiments and further developments of the teaching. In the Drawings <sl><li>FIG. 1 in a schematic side view, partially cut away, FIG An exemplary embodiment of an internal combustion engine according to the invention in detail, namely An arrangement for ignition with spark ignition device with particularly long Electrodes at the time of fuel injection,</li><li>FIG. 2 is a schematic side view, partially cut away from FIG 1 in the top dead center of the piston immediately after introduction The ignition,</li><li>FIG. 3 is a schematic side view, partially cut away, of FIG A further exemplary embodiment of an internal combustion engine according to the invention, namely An arrangement for ignition with a piston arranged in the trough of the piston A metal pin, which serves as a ground electrode,</li><li>FIG. 4 is a schematic side view, partially cut away, of FIG A further exemplary embodiment of an internal combustion engine according to the invention, namely An arrangement with a cylindrical pre-chamber spark ignition device with ignition In the central region of the antechamber,</li><li>FIG. 5 is a schematic cross-sectional view taken along line AA. FIG The object from FIG. 4,</li><li>FIG. 6 is a schematic side view, partially sectioned, of FIG A further exemplary embodiment of an internal combustion engine according to the invention, namely An arrangement with a cylindrical vortex chamber spark igniter Multiple ignition in the wall area of ​​the vortex chamber with tangentially running overflow ducts,</li><li>FIG. 7 is a schematic cross-sectional view taken along line AA. FIG The object from FIG. 6,</li><li>FIG. 8 is a schematic side view, partially sectioned, of FIG A further exemplary embodiment of an internal combustion engine according to the invention, namely An arrangement with a common spark plug with a central electrode and at least A mass electrode at the time of fuel injection,</li><li>FIG. 9 is a schematic side view, partially cut away of FIG 8, in the top dead center of the piston, in which a ring gap between Piston bottom and cylinder head,</li><li>FIG. 10 is a schematic side view, partly in section, of FIG A further exemplary embodiment of an internal combustion engine according to the invention, namely An arrangement with a pre-chamber spark ignition device at the time of fuel injection,</li><li>FIG. 11 is a schematic side view, partially cut away of FIG The subject of FIG. 10 in the top dead center of the piston,</li><li>FIG. 12 is a schematic side view, partially cut away and FIG FIG. 3 is a detailed view of a vortex chamber spark ignition device with several electrodes Sparks in the top dead center of the piston,</li><li>FIG. 13 is a cross-sectional view of the object from FIG. 12 in the plane Of the tangential transfer channels,</li><li>FIG. 14 is a schematic side view, partially cut away and FIG Enlarged, a detailed view of a further vortex chamber spark ignition device, Wherein a central connection bore is provided to the vortex chamber in the region of the end face And additional connection bores between the end face of the vortex chamber And the tangential transfer channels of the vortex chamber spark igniter to lead,</li><li>15 shows in a cross-section the object from FIG. 14 in the plane Of the tangential transfer channels,</li><li>FIG. 16 is a schematic side view, partially cut away and FIG FIG. 10 is a detailed view of a vortex chamber spark ignition device, FIG Connecting bores from the front side of the vortex chamber to the transfer channels In the top dead center and wherein the tangentially emerging torch beams To the side wall of the piston recess, and</li><li>FIG. 17 is a schematic cross-sectional view of the object from FIG. 16 in the plane of the transfer channels which enter tangentially into the vortex chamber.</li></sl>

The figures show together various exemplary embodiments of an internal combustion engine With direct fuel injection and spark ignition, with the Combustion chamber 1 through a cylinder block 2, a cylinder head 3 and a piston 4 Is formed. A depression 6 is formed in the piston surface 5. The fuel is Can be injected in the direction of the trough 6 by an injection nozzle 7 and via a spark ignition device 8 can be ignited.

According to the invention, the trough 6 is positioned and formed in the piston 4 Or dimensioned in such a way that the spark ignition device 8, already before reaching the Ignition time at least with its free end 9 into the trough 6 with little play And when the top dead center of the piston 4 is reached with little play Is immersed in the trough 6 and at the same time largely fills the trough 6.

FIG. 1 shows an internal combustion engine according to the invention in a sectional view, namely In the region of the combustion chamber 1, namely to the ignition of very lean fuel-air mixtures, Wherein a spark ignition device 8 with a particularly long Electrode 10 is used. The electrode 10 is substantially central to the electrode Through the cylinder head 3, the piston 4 and the cylinder wall 11 1 of the internal combustion engine. The piston 4 is in a position During the compression process, in which the fuel from the injection nozzle 7 is injected essentially in the direction towards the trough 6. This can be for example Combustion process, valve arrangement, fuel beam angle, etc. at a crank angle Of the engine can be between 40 degrees and 80 degrees KWv OT and eg Over 15 degrees KW.

Within the limits of the fuel jet 12, the fuel density distribution is ia Approximately by a normal distribution 13 indicated in FIG. 1, Wherein particularly large fuel drops are located in the core region of the fuel jet 12 Are located. In connection with a short injection duration, for example 0.5 -1.0 ms, Ensure that the piston reaches the high speed range Of the injection process only passes through a small stroke, so that large fractions of the Fuel within the trough 6 or in the immediate vicinity of the trough 6 Or as a fuel-enriched mixture in the Trough 6 or the trough 6 can be pre-stored.

During the further compression process, ie the further compression of the Fuel-air mixture in the combustion chamber 1, the air is heated on the piston surface 5 fuel in and outside the trough 6 and vaporizes. In addition A pronounced charge movement occurs from the combustion chamber 1 In the direction of the trough bottom 14, whereby the fuel portions, which are arranged in front of the trough 6, For the most part are also transported into the trough 6.

To the proportion of the fuel entering the trough 6 by the fuel injection , The trough 6 can be at the upper edge in the injection direction of the fuel Have a bevel 15.

In FIG. 2, the arrangement according to FIG. 1 is directly in the top dead center (OT) of the piston 4 After the initiation of the ignition. As a result of fast piston movement In the direction of the top dead center of the piston 4 immediately before the piston Ignition occurs in the trough 6 to an intense charge movement, however, A mass exchange with the combustion chamber 1 is largely suppressed so that In the region of the ignition electrode 10 at the ignition time, a comparatively homogeneous And opposite the mixture composition in the combustion chamber 1 with fuel Enriched mixture.

In the further exemplary embodiment shown in FIG. 3, Shaped metal pin 16 as a ground electrode for the spark ignition device 8. This arrangement results in a particularly low disturbing effect Of the electrodes 10 to the flame propagation. The in the TDC position of the piston 4 results in accordance with the dependence of the ignition angle Motor operating point results in a variable and, in the medium, particularly large electrode spacing. By the choice of an adapted ignition system with high voltage supply And low shunt sensitivity are particularly good Ignition properties.

FIG. 4 shows the section through a special spark ignition device 8, namely FIG Through a prechamber spark plug 17, with ignition in the central region of the prechamber 18 in the TDC position of the piston 4. When penetrating the cylindrical Ignition chamber or prechamber 18 into the trough 6, the pressure generated in the trough 6 and 13 is increased In particular on the base 14, is enriched with fuel Are pushed into the prechamber 18 by the transfer channels 19 located in the bottom And directed into the region of the ignition point 20. A possibly still on the walls The liquid fuel portion located in the trough 6 is caused by the high flow velocity Between the prechamber 18 and the trough 6 and atomized This mixture then either into the ignition chamber or prechamber 18 or laterally Is bypassed at the ignition chamber 18. Thereafter, a part of the laterally escaping, Fuel-enriched mixture via radial overflow ducts 21 the prechamber 18.

To improve the ignition of the mixture in the prechamber 18, Ignition electrodes 10 in the front region and can be made of noble metal, for example Or as electrodes coated with noble metal.

After initiation of the ignition, the air is radiated from the ignition chamber or prechamber 18, which generate a fast, And uniform combustion of the mixture in the combustion chamber 1. At the same time First unburnt and subsequently burned, enriched with fuel Air mixture through the air in the bottom region of the ignition chamber or prechamber 18 And then presses the unburned and Later, the combusted mixture passes through the annular gap 22 between the ignition chamber Prechamber 18 and trough 6. Through this mixture and the During the compression stroke in the vicinity of the prechamber 18, Fuel enriched mixture as well as by the large charge movement An intense combustion takes place in the further environment of the prechamber 18, Which additionally contributes to a safe and uniform ignition Of the very lean fuel-air mixture in the further vicinity of the ignition chamber Or prechamber 18.

The combustion gases emerging on the front side of the ignition chamber or prechamber 18 Even at low piston temperatures such as occur during, for example, Of the warm-up of the engine, a complete combustion of all before introduction Of the ignition in the trough 6 possibly remaining liquid fuel residues. Simultaneously, rapid heating of the trough 6 occurs, so that An extremely lean engine operation is very early on after a cold start of the engine is possible.

FIG. 5 shows a cross-section through the arrangement according to FIG. 4 at the level of the radial Overflow channels 21.

FIG. 6 shows a further exemplary embodiment of an internal combustion engine according to the invention, Namely a further variant of a spark ignition device 8 in the form of a Alternative prechamber spark plug 17. This is in concrete terms A vortex chamber spark ignition device, with which, by the generation of a Swirl flow through tangentially arranged overflow channels 23 and use A multiple center electrode device 24, with which a plurality of spark gap sections 25 to the substantially cylindrical inner wall of the vortex chamber 26 Are still very lean mixtures Can be ignited. This makes it possible to make greater fluctuations in the air number At the ignition point 20, as is the case, for example, in connection with non-stationary driving conditions Be able to safely control.

On the one hand, a particularly far-reaching enrichment of the mixture at the ignition point 20 and, on the other hand, a particularly good reproducibility of the mixture composition And homogenization in the region of the ignition spark, During the immersion of the ignition chamber or prechamber 18 into the trough 6 On the one hand by a central bore 27, which is designed as a central overflow channel Fuel enriched mixture from the bottom region of the trough 6 into the Central region of the cross-section in the region of the ignition electrodes 10. To the Another is enriched with fuel via the tangential overflow channels 23 Mixture from the bottom and side region of the trough 6 into the Turbulent chamber 26, this mixture circulating around the main axis of the vortex chamber 26, and the central hole formed by the central bore 27 Beam. This results in the entire cross-section of the ignition plane Particularly well enriched fuel mixture.

For the particularly good enrichment of the water flowing through the tangential transfer channels 23 Flowing mixture with fuel are on the outer side of the lower portion Of the vortex chamber 26 are arranged grooves 28, which form the enriched mixture of the Bottom region during the penetration of the ignition chamber or prechamber 18 into the Trough 6 in front of the tangential overflow channels 23.

FIG. 7 shows a cross-section through the arrangement according to FIG. 6 at the level of the tangential Overflow channels 23, so that these are particularly clearly recognizable there.

FIG. 8 shows a further arrangement for ignition and combustion in an internal combustion engine With direct fuel injection and spark ignition As in FIGS. 1 to 3, the spark ignition device 8 with conventional electrodes 10 is used to ignite the mixture in the combustion chamber 1. The combustion chamber 1 Is formed by the cylinder head 3, the cylinder block 2 and the piston 4. Of the Piston 4 is shown in a position during the compression process in which the Fuel is injected from the injection nozzle 7 in the direction towards the trough 6.

Especially when the fuel is injected during the compression cycle There is a risk that the fuel jet 12 will strike the surface The trough 6 and the trough bottom 14 still contain liquid fuel parts, Which precipitate as fuel film or finely divided droplets 29.

During the further compression process, ie during the further compression Of the air / fuel mixture in the combustion chamber 1, the air is heated on the trough surface 14 and the piston surface 5 (droplets 29) And is partially blended into the fuel-air mixture above the surfaces 14,

Particularly when the engine is not hot, there is a risk that even when the engine is not running, Compression a small portion of the fuel as a wall depression on the well surface 14 and / or on the piston surface 5 in the narrower environment Of the trough 6 is maintained.

FIG. 9 shows the arrangement according to FIG. 1 in the TDC of the piston 4 immediately after the introduction Of the ignition. As a result of the fast piston movement in the direction of TDC of the piston 4, there is an intense flow in the trough 6 and in the vicinity thereof Which causes a particularly uniform ignition at the ignition location 20 Composition of the fuel-air mixture with a particularly ignitable composition Respectively. Specifically, when approaching the TDC from the piston 4 and Cylinder head 3 from the trough 6, a kind of prechamber is generated, which is connected via a ring-shaped, Flow passage 30 in the radial direction with the combustion chamber 1 Is. As a result of the combustion and the high-speed piston-close The hot gases exiting the annular-shaped overflow channel 30 are ensured, That a liquid fuel is formed on the trough surface 14 and the piston surface 5 is safely dismantled and an early efficiency - optimized and Low-pollutant combustion of the entire fuel present in the combustion chamber 1 Is reached.

FIG. 10 shows a further arrangement in which a prechamber spark plug 17 is used, in which substantially in the middle region of the combustion chamber 1, overflow ducts 23 Which open radially or tangentially into the prechamber 18. After Of the ignition are generated by these torch beams, which are essentially from the Center of the combustion chamber 1 is directed radially in the direction of the cylinder wall are.

The piston 4 is shown in a position during the compression process in FIG The fuel from the injection nozzle 7 moves essentially in the direction towards the trough 6 Is injected.

The comparatively small trough 6 is surrounded by a further larger trough or trough A widened portion 31 which is substantially symmetrical about the Well 6 is formed. The fuel jet generated by the injection nozzle 7 12 is designed in such a way that it is arranged essentially centrally on both troughs 6, 31, and the outer beam edge 32 does not extend beyond the edge of the widened Region 31 of the trough 6.

The piston bottom or the piston surface 5 is light outside the trough 6 Is formed obliquely in the direction of the cylinder head 3 so as to cooperate with an outer, Likewise obliquely shaped part 33 of the cylinder head 3 essentially Which is formed in the combustion chamber 1 at approximation To the OT.

Furthermore, in FIG. 10, an arrow 34 is used to indicate a swirling flow, Especially when later injection of the fuel is necessary to provide a stable charge coating In the combustion chamber 1 and to achieve rapid energy conversion.

In view of stable and uniform charge coating and combustion It is also advantageous if the injection nozzle 7 is arranged as centrally as possible and The injection beam axis 35 has a particularly small angle with respect to the main axis of the Combustion chamber 1. In other words, the fuel jet 12 becomes as much as possible Steeply towards the central region of the piston surface 5. This requires one Close proximity of the spark ignition device 8 to the injection nozzle 7.

However, in the case of early injection, a fuel / air mixture which is as homogeneous as possible A larger fuel spreading angle is useful. Thereby A part of the fuel is applied to the prechamber spark plug 17, thereby causing cooling And a transport of fuel during the compression process into the prechamber 18. Both properties are not an enormous advantage.

FIG. 11 shows the arrangement from FIG. 10 in the TDC position of the piston 4 When the cylindrical ignition chamber 18 penetrates into the trough 6, In the region of the trough bottom 14, with fuel Enriched mixture through on or in the bottom of the well 14 or on the outer side Of the pre-chamber 18, overflow channels 23 and / or recesses Into the prechamber 18. In addition, when approaching OT Increasingly "rich" fuel-air mixture from the region above the trough 6 Or the extended region 31 of the trough 6 via the transfer channels 21, 23 in FIG The prechamber 18 is pushed in and directed into the region of the ignition point 20. On Possibly still present on the walls of the trough 6. In this way, By the high flow velocity between the prechamber 18 and the trough 6 And this mixture is then either passed into the ignition chamber Or prechamber 18 or laterally past the ignition chamber or prechamber 18 Is steered.

When approaching TDC occurs between the outer oblique surfaces of the piston 4 (the piston surface 5) and the corresponding beveled surfaces The corresponding bevelled part 33 of the cylinder head 3 is provided with a nip gap 36. The resulting squeezing flow 37 produces in the upper region of the A flow directed to the center of the combustion chamber 1, which either Air or very lean fuel-air mixture from the outer edge of the combustion chamber 1 into the region of the injection jet axis 35. This flow 36 A swirl flow is superimposed, as shown in FIG. 10, and the ring- Flow directed through the dipping of the pre-chamber spark plug 17 into the trough 6.

After initiating the ignition, a variety of torch beams are formed 38, which bring about a flow of hot combustion gases close to the bottom of the piston.

FIG. 12 shows, in an enlarged illustration, a longitudinal section through a prechamber spark plug 17 in the region marked by a circle 39 in FIG. Of the Section shows an arrangement designed as a vortex chamber spark ignition device, With generation of a swirl flow through tangentially arranged transfer channels 23 and the use of a multi-center electrode 24 known per se A plurality of spark gaps 25 to the substantially cylindrical inner wall Of the vortex chamber 26.

On the one hand, a desired mixture enrichment at the ignition point 20 and on the other hand A particularly good reproducibility of the mixture composition And homogenization in the region of the ignition spark, are the overflow ducts 23 in the front region as a diffuser 40. The outward Expanding shape of the diffuser 40 causes, at the same time, Burnt hot gases from the vortex chamber 26 caused a rapid fan-out of the Torch beams 38 and thus an early approach of the hot gases to the Piston bottom 5 outside the trough 6.

The inclination of the transfer channels 23 opposite the piston base 5 becomes advantageous Is selected such that, on the one hand, a good evaporation of the fuel takes place And, on the other hand, a not too great heat transfer to the piston base 5.

To the mixture flowing over the tangentially arranged overflow channels 23 With a high fuel content, are arranged on the outer side of the lower Region of the turbulence chamber 26, grooves 28 are arranged, which are filled with fuel or with fuel Enriched mixture from the bottom region of the trough 6 during the penetration Of the cyclone spark plug or spark ignition device into the trough 6 Before the transfer channels 23.

FIG. 13 shows in a cross-section through the arrangement from FIG. 12, namely in height Of the tangential overflow channels 23.

FIG. 14 shows a further variant of a vortex chamber spark ignition device A plurality of spark gap sections 25, namely in the TDC position of the piston 4 Which are configured as connecting bores Between the end face of the vortex chamber spark igniter and the prechamber spark plug 17 and the transfer channels 23. During the filling process, Of the turbulence chamber 26 is enriched with a fuel-enriched mixture from the bottom region Of the trough 6 is sucked by a jet pumping action, the jet pumping effect In the region of the connection of the transfer channels 23 and the connection bores Is generated. By the same effect, when the hot air is emitted Gases via the overflow ducts 23 penetrate these gases into the bottom region Of the trough 6 is suppressed. Through this measure, overall The thermal load on the trough bottom 14 of the trough 6 is reduced.

In the variant explained above, but also in other variants, In addition a small central bore 27- as a further overflow channel-to the filling Of the central front portion of the swirl chamber 26 can be used. By This overflow channel 27 is also ensured at the same time that, after ignition and ignition, There is no liquid fuel in the bottom region of the trough 6 to the exit of hot combustion gases Respectively.

FIG. 15 shows a cross-section through the arrangement from FIG. 14, namely in height Of the tangential overflow channels 23.

FIG. 16 also shows a schematic representation, enlarged, of a further embodiment Variant of a vortex chamber spark ignition device, during the immersion The antechamber 18 or the front region of the swirl chamber 26, respectively The hot combustion gases exiting the tangential overflow ducts 23 on the side wall Of the trough 6 and in the annular gap 22 between the outer wall of the Swirl chamber 26 and the inner wall of the trough 6, After the hot gases have escaped from the annular gap 22, a surface which is adjacent to the piston surface 5 from hot combustion gases.

In order to reliably control the thermal load on the piston 4, the trough 6 is formed Is lined with a sleeve 43 of highly heat-resistant material. Such a lining The trough 6 can, of course, also be in a different state from that shown here Arrangement.

In order to prevent liquid fuel from flowing directly through the transfer channels 23, To the ignition point, is between the tangential junctions of the transfer channels 23 into the vortex chamber 26 and to the ignition points 20 a collecting device 44 for liquid fuel parts, which in the exemplary embodiment selected here Is formed as a radially outwardly directed, annular groove.

Finally, FIG. 17 shows a cross-section through the arrangement from FIG. 16, and FIG Again at the level of the tangential transfer channels 23.

Finally, it should be pointed out that the above-mentioned Embodiments of the exemplary discussion of the invention But do not limit them to the exemplary embodiments.