DE102006029210A1 - Fuel injector for e.g. diesel engine, has electrode pairs arranged such that spark gap possesses conical fuel injection beam that is left from nozzle, where spark gap is formed during extraneous ignition - Google Patents

Abstract

The injector (1) has electrode pairs (2a, 2b, 2d) with cathodes (3a, 3b, 3d) and anodes (4a, 4b, 4d ), which are electrically isolated and spaced from each other. A jet needle (7) is moved between idle and working positions in a direction of a longitudinal axis (15) of the injector and locks a nozzle in an idle position. The needle releases a nozzle (5) for injection of fuel into a cylinder. The electrode pairs are arranged such that a spark gap possesses a conical fuel injection beam (17) that is left from the nozzle within injection, where the spark gap is formed during extraneous ignition.

Description

• – mindestens einer Düsenöffnung zur Zuführung des Kraftstoffes in den Zylinder,
• – einer in Richtung Längsachse der Einspritzdüse zwischen einer Ruheposition und einer Arbeitsposition in einer Düsennadelführung verschiebbaren Düsennadel, wobei die Düsennadel die mindestens eine Düsenöffnung in der Ruheposition verschließt und in der Arbeitsposition zur Einspritzung des Kraftstoffes freigibt,
• – einer die Düsennadelführung umgebenden ersten Isolierung, und
• – mindestens einem Elektrodenpaar, das zwei voneinander elektrisch isolierte und beabstandete Elektroden umfasst, wobei die erste Elektrode als Anode und die zweite Elektrode als Kathode dient und das Elektrodenpaar beabstandet zu der mindestens einen Düsenöffnung angeordnet ist.

The invention relates to an injection nozzle, in particular for the injection of fuel into a cylinder of a direct-injection spark-ignited internal combustion engine, with

• At least one nozzle opening for feeding the fuel into the cylinder,
• A nozzle needle which is displaceable in the direction of the longitudinal axis of the injection nozzle between a rest position and a working position in a nozzle needle guide, wherein the nozzle needle closes the at least one nozzle opening in the rest position and releases it in the working position for injection of the fuel,
• A first insulation surrounding the nozzle needle guide, and
• - At least one electrode pair, the two electrically insulated and spaced apart electrodes comprises, wherein the first electrode serves as the anode and the second electrode as a cathode and the electrode pair is spaced from the at least one nozzle opening.

by virtue of the limited resources of fossil fuels, in particular due to the limited presence of mineral oil as a raw material for extraction of fuels for the operation of internal combustion engines, one is in the development of internal combustion engines constantly endeavored to To minimize fuel consumption. In addition, a principle Reduction of pollutant emissions sought to meet future limits for pollutant emissions observed. Therefore, a qualitatively improved d. H. fewer Pollutant-generating combustion or a more efficient d. H. Consumption - optimized combustion in the forefront of efforts in the Framework of development work.

Problematic is the fuel consumption especially due to the worse Efficiency in gasoline engines. The reason for this lies in the principle working method of the traditional gasoline engine. The traditional gasoline engine works with a homogeneous fuel-air mixture that through external mixture formation is prepared by fuel into the intake air in the intake system is introduced. The desired power is set by change the filling of the combustion chamber, allowing the work process of the gasoline engine - different as the diesel engine - one quantity control underlying.

These Load control is usually done by means of a in the intake provided throttle. By adjusting the throttle valve can the pressure of the sucked air behind the throttle more or be reduced less. The further the throttle valve is closed is d. H. the more it blocks the intake the higher the pressure loss of the intake air across the throttle and the lower the pressure of the intake air behind the Throttle and before the inlet into the combustion chamber. At constant Combustion chamber volume can be sucked in this way over the pressure of the Air the air mass i. the quantity will be set. This explained Also, why this type of quantity control especially in the partial load range proves to be disadvantageous because low loads require a high Throttling and pressure reduction in the intake tract. The quantity regulation Throttle valve therefore has thermodynamic disadvantages. To the To reduce throttling losses described above have been different strategies developed for load control. An approach to de-throttling the Ottoman working method is in use a variable valve train.

One another approach to improve the fuel consumption of gasoline engines on the takeover technical features, originally as a characteristic of the diesel engine method. This leads to new ones so-called hybrid combustion process.

The Traditional Ottoman process is characterized by a mixture compression, a homogeneous mixture, a spark ignition, and the quantity regulation, whereas the diesel engine process is characterized by an air compression, an inhomogeneous mixture, a self-ignition and the quality regulation. The low fuel consumption of diesel engines results under from a high compression ratio and low charge cycle losses due to the quality regulation of the diesel engine, where the load is controlled by the amount of fuel injected becomes.

Especially the injection of fuel directly into the combustion chamber of the cylinder is considered a suitable measure fuel consumption is also noticeable for gasoline engines why the development of direct-injection gasoline engines has become increasingly important. Further advantages arise due to - with a direct injection principle connected - internal cooling of the Combustion chamber or of the mixture, whereby a higher compression and / or charge and consequently a better utilization of the fuel without that for the gasoline engine otherwise characteristic early spontaneous combustion of the fuel, the so-called knocking seems possible.

In this case, the fuel is preferably injected directly into the combustion chamber, ie, into the cylinder of the internal combustion engine during the compression phase. 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, as well as the ignition of the treated mixture are comparatively short periods of the order of milliseconds available.

Consequently usually lies during the ignition and combustion a very inhomogeneous fuel-air mixture, which is not characterized by a uniform air ratio, but both lean (λ> 1) mixed parts as also fat (λ <1) mixture parts having. The formation of the for the diesel engine process characteristic soot, the in mixture parts with a substoichiometric air ratio (λ <0.7) and at temperatures above 1300 ° K is formed under extreme lack of air, it is accepted.

conditioned by the direct injection of the fuel into the combustion chamber, Little time to prepare an ignitable and combustible fuel-air mixture to disposal direct injecting Otto engine methods are much more sensitive against changes and deviations in the mixture formation, in particular in the injection, and the ignition as conventional ottomotor Method. The inhomogeneity of the mixture in direct injection gasoline engines makes it difficult in principle a safe and defined inflammation of the fuel-air mixture.

Out the reasons mentioned On the one hand, the aim is to improve the mixture preparation. On the other hand is a very fine - both spatial and temporal - vote of injection and ignition required, in particular a coordinated arrangement from injector and spark plug in the combustion chamber, which is already due to the very limited space available in the cylinder head of the internal combustion engine is only partially possible. To be considered is there in the cylinder head already the control - in the Usually poppet valves - and oil channels and, where appropriate the cooling channels one water cooling are provided, so that in particular in the case of the prior art preferred four-valve engines, which are due to the great for the change of charge provided flow cross-section characterized by an optimized gas exchange, very cramped space available. in principle will be considering one of manufacturing and assembly tolerances as accurately defined arrangement of injection and spark plug aimed at each other.

in the essential can three methods, the direct injection gasoline engine for mixture formation and combustion can be distinguished.

In the air-fired combustion process, an attempt is made to generate a charge movement when the air is drawn into the combustion chamber, in order to achieve a good mixing of the intake air and the directly injected fuel. In this case, the widest possible distribution of the fuel throughout the combustion chamber is sought. In the in the EP 1 258 622 For this purpose, an air vortex generator for generating a so-called tumbles is used and the injection jet directed against the air flow.

At the wall-guided Method, the fuel is injected into the combustion chamber in the manner that the injection jet targeted to a wall bounding the combustion chamber is directed, preferably in a provided on the piston head Trough. The fuel jet is intended by the impact in several Partial beams are split and deflected, leaving one as possible greater Area of the combustion chamber is detected by the fuel jets.

At the spray-guided The fuel is deliberately directed towards the spark plug injected, which by a corresponding orientation of the injection jet is achieved or by an appropriate arrangement of injector and spark plug in the combustion chamber, for example, opposite or close to each other. The mixture transport takes place essentially by the pulse of the injection jet, wherein the movement of the sucked air of is of secondary importance. Compared to the previously described The method is the expansion of the processed fuel-air mixture cloud limited in principle. Especially for the stratified operation the internal combustion engine, the spray-guided process is considered to be effective.

however is the spray-guided Processes are particularly sensitive to changes and deviations at injection and at ignition. This results usually rotational irregularities i.e. Speed fluctuations of the brake motor and misfires like knocking or misfiring, which the use of spray-guided Combustion process, especially the stratified charge, only in a very limited speed and Allow load range of the internal combustion engine. This disadvantage will but accepted, as the spray-guided process in direct injection Gasoline engines further consumption advantages promises.

the limited application of the spray-guided method can by the integral formation of injector and spark plug which subject of the present invention.

The Direct injection of the fuel is usually with a partial increased Pollutant emission associated. The spray-guided process also promises to do so in direct injection gasoline engines Advantages d. H. an improvement of the caused by the direct injection d. H. deteriorated Emission behavior.

Regarding the measure already mentioned above, the arrangement of the injection nozzle and the spark plug in the combustion chamber to ensure a safe ignition of the To ensure a fuel-air mixture found in the prior art, a proposed solution in which the spark plug and the injector be combined into one component.

The DE 37 31 211 A1 describes a generic fuel injector ie an injector according to the preamble of claim 1, with the fuel in the cylinder of a spark-ignited internal combustion engine can be injected and the injected fuel can also be ignited.

The Association of the two components, namely the spark plug and the injection valve, to a single component has several advantages. On the one hand, the very limited space in the cylinder head of the engine Taken into account. On the other hand, the injection nozzle and spark plug are arranged close to each other, being the for a safe ignition authoritative Components, in particular the nozzle openings and the electrodes have a defined immutable position relative to each other and thus also the spark gap generated between the electrodes in terms of through the nozzle openings exiting fuel injection jets. The solid component geometry is to be regarded as advantageous in terms of safe inflammation.

That in the DE 37 31 211 A1 Although described fuel injector combines injector and spark plug to a component, which leads to the advantages shown. However, these two components are not optimally matched in their structural design, but only arranged in immediate proximity to each other.

In the fuel injection valve according to the DE 37 31 211 A1 the pairs of electrodes are equally spaced on a circle arranged concentrically about the longitudinal axis of the nozzle needle, wherein the spark gap is formed at the initiation of the ignition in the circumferential direction of this circle ie tangentially. The fuel emerging from the nozzle opening forms a screen jet.

If, however, the nozzle is equipped with a plurality of nozzle orifices, so that there are several isolated fuel injection jets during injection of the fuel, reliable ignition with an arrangement of the electrode pairs as shown in US Pat DE 37 31 211 A1 is no longer guaranteed.

Therefore Further optimizations are required to increase the inflammation improve, especially in terms of reliability and the maintenance of a given ignition timing. It will be one preferably slight deviation of the actual ignition timing sought from a predetermined setpoint for the ignition.

In front In this context, it is the object of the present invention an injection nozzle according to the generic term of claim 1, with that of the prior art known problems is counteracted, in particular a safe inflammation of the inhomogeneous fuel-air mixture ensures and the use of spray-guided Combustion process, in particular the layer charge supported.

• – mindestens einer Düsenöffnung zur Zuführung des Kraftstoffes in den Zylinder,
• – einer in Richtung Längsachse der Einspritzdüse zwischen einer Ruheposition und einer Arbeitsposition in einer Düsennadelführung verschiebbaren Düsennadel, wobei die Düsennadel die mindestens eine Düsenöffnung in der Ruheposition verschließt und in der Arbeitsposition zur Einspritzung des Kraftstoffes freigibt,
• – einer die Düsennadelführung umgebenden ersten Isolierung, und
• – mindestens einem Elektrodenpaar, das zwei voneinander elektrisch isolierte und beabstandete Elektroden umfasst, wobei die erste Elektrode als Anode und die zweite Elektrode als Kathode dient und das Elektrodenpaar beabstandet zu der mindestens einen Düsenöffnung angeordnet ist, und die dadurch gekennzeichnet ist, dass
• – das mindestens eine Elektrodenpaar in der Art angeordnet ist, dass eine sich zwischen den das Elektrodenpaar bildenden Elektroden im Verlauf der Fremdzündung ausbildende Funkenstrecke im wesentlichen die Ausrichtung eines aus einer Düsenöffnung im Rahmen der Einspritzung austretenden kegelförmigen Kraftstoffeinspritzstrahls aufweist.

This problem is solved by an injection nozzle

• At least one nozzle opening for feeding the fuel into the cylinder,
• A nozzle needle which is displaceable in the direction of the longitudinal axis of the injection nozzle between a rest position and a working position in a nozzle needle guide, wherein the nozzle needle closes the at least one nozzle opening in the rest position and releases it in the working position for injection of the fuel,
• A first insulation surrounding the nozzle needle guide, and
• - At least one pair of electrodes, comprising two electrically insulated and spaced apart electrodes, wherein the first electrode serves as an anode and the second electrode as a cathode and the pair of electrodes spaced from the at least one nozzle opening, and which is characterized in that
• - The at least one pair of electrodes is arranged in such a way that between the electrode pair forming electrodes in the course of the spark ignition spark gap essentially has the orientation of a emerging from a nozzle opening during the injection cone-shaped fuel injection jet.

The injector according to the invention leads to a safe ignition of the inhomogeneous fuel-air mixture in direct injection gasoline engines, because the position of the spark gap, which forms in the context of the ignition between the electrodes, and the position of the fuel injection jet, in the context of injection from a Nozzle outlet exits, are matched to each other and are subject by the integral design only small tolerances, which are essentially due to the manufacturing tolerances.

In contrast to that in the DE 37 31 211 A1 described fuel injector, in which the spark gap is perpendicular to the path or on the pulse of the injected fuel particles have in the injector according to the invention spark gap and fuel injection jet substantially the same orientation.

in the The scope of the present invention is intended to be substantially the same Alignment of spark gap and fuel injection jet assumed when spark gap and fuel injection jet tip Angle α <45 ° C or α <20 ° C form, wherein the center axis of the fuel injection jet for the determination of the angle and the levels i. the plane that from the longitudinal axis the nozzle and the injection jet is spanned, and the plane of the longitudinal axis the nozzle and the spark gap is spun into each other.

Becomes for injection and ignition only one component needed or used, this is particularly in view of the limited space in the cylinder advantageous. The injector and the spark plug are arranged close to each other and have a defined unchanging Location to each other, resulting in the desired Success, namely a safe inflammation of the fuel-air mixture, contributes.

The Injector according to the invention only needed a bore, whereby the flow cross sections be executed enlarged can, whereby the charge exchange is improved. At the same time in the Cylinder head a larger installation space cross-section for the water cooling be provided.

Thereby the problem underlying the invention is solved, namely a Injection nozzle according to the preamble of claim 1, which is a safe inflammation of the Ensures inhomogeneous fuel-air mixture and the use of spray-guided Combustion process, in particular the layer charge supported.

By the injection nozzle according to the invention the possible uses of the stratified, direct-injection and spray-guided combustion process with regard to the possible Speed and load ranges significantly expanded and both the thermodynamic Efficiency and thus both the torque characteristics and the Fuel consumption, as well as the emission behavior significantly improved.

Further Advantages of the injection nozzle according to the invention are in connection with the embodiments according to the subclaims.

Advantageous are embodiments the injection nozzle, in which the at least one pair of electrodes in the region of the conical fuel injection jet lies, which from the at least one nozzle opening as part of the injection exit.

at this embodiment Both the spark gap and the fuel injection jet are not only in the essentially aligned the same, but also spatially together arranged, which is why the fuel injection jet, the spark gap, for example can also cross or affect. In a borderline case, these affect vaporizing droplets in the edge zone of the cone-shaped Fuel injection jet the spark gap.

As in the context of the description of the figures will become clear, according to a embodiment the injector according to the invention, the electrode pairs on concentric spherical surfaces around the long axis of the nozzle needle be arranged around, wherein the anode on a sphere smaller Diameter and the cathode is on a larger diameter ball or vice versa. The nozzle openings can while the side of the nozzle be provided, wherein the spark gap, the lateral surface of a passes through the injection cone formed injection cone or tangent.

Advantageous are embodiments the injection nozzle, in which a centrally disposed nozzle opening is provided, wherein a from this nozzle opening in Frame of injection leaking fuel jet substantially parallel to the longitudinal axis the injector runs.

The orifices should be in the area of the nozzle tip be arranged in the way that the injected fuel preferably evenly in the combustion chamber is distributed. In this case, a centrally arranged nozzle opening is basically expedient.

In addition, a centrally disposed nozzle opening also offers advantages in terms of oil dilution, which will be discussed briefly below. Depending on the injection time reaches a more or less large proportion of the injected fuel to the cylinder inner wall, mixes there with the adhering oil film and then passes together with the oil and the blow-by gas into the crankcase. By changing the lubricant properties of the oil has the oil dilution significantly influence the wear and durability, ie the life of the internal combustion engine.

Of the Fuel injection of a centrally located nozzle opening is directed to the piston head of the piston, which is why by this Injected nozzle opening Fuel does not get on the cylinder inner wall and therefore do not contribute to oil thinning can and does this independently from the injection time.

Advantageous are embodiments the injection nozzle, in which at least two lateral nozzle openings are provided, wherein from these nozzle openings in the context of the injection emerging fuel jets on the lateral surface an imaginary cone lie and the longitudinal axis of the injector axis of this imaginary cone.

As already executed before, should the fuel during injection, if possible evenly in the combustion chamber be distributed. Laterally arranged nozzle openings cause the injection jets the combustion chamber spacious capture, resulting in the formation of a homogeneous fuel-air mixture leads.

Advantageous are embodiments the injection nozzle, in which a centrally disposed nozzle opening and four lateral nozzle openings are provided. Research has shown that this training the nozzle is particularly advantageous, in particular with regard to the mixture preparation in direct injection internal combustion engines.

Advantageous are embodiments the injection nozzle, in which the imaginary cone has a cone opening angle γ with 45 ° <γ <135 °. embodiments the injection nozzle, in which the imaginary cone has a cone opening angle γ with 60 ° <γ <120 °, or embodiments the injection nozzle, in which the imaginary cone has a cone opening angle γ with 75 ° <γ <105 °, but can also be advantageous.

On the one hand should the cone opening angle γ possible be great so that the injection jets capture the combustion chamber over a wide area. on the other hand takes the oil dilution with As the opening angle γ increases, since at larger opening angles γ more fuel reaches the cylinder inner wall than at smaller opening angles γ, in which the fuel predominantly hits the piston crown.

The In addition, the effects described are also influenced by the time of injection. To be considered is about it In addition, which combustion method is used and whether in operation the internal combustion engine frequently injected late is and / or post-injections are made, for example to increase the exhaust gas temperature or to enrich the exhaust gas with unburned hydrocarbons.

Out the reasons mentioned can in some applications a smaller cone opening angle γ advantageous be while in other cases a larger taper angle γ to be preferred is.

in the When defining the cone angle γ, the characteristic combustion chamber shape should optionally be used and the piston shape are taken into account. It can in four-stroke engines also in two mutually perpendicular planes parallel to the cylinder main axes, two different cone angles are used, for. B. with dachförmigem piston with Valve bags. roof-shaped Guide the piston to an unbalanced combustion chamber shape, so adjusted to a more unbalanced Injection may be beneficial.

Advantageous are embodiments the injection nozzle, where for each side nozzle opening Electrode pair is provided. In this embodiment, the fuel each lateral injection jet either by means of a separate d. H. own pair of electrodes ignited, so that the combustion the fuel-air mixture at several places in the same time Combustion chamber is initiated. Or else it stands - if the side nozzle openings are arranged between the pairs of electrodes - two for each lateral nozzle opening Electrode pairs available; with four lateral and a centrally located nozzle opening with it for the central nozzle opening even four electrode pairs. Also in this variant is the combustion of the fuel-air mixture initiated at several points in the combustion chamber. This ensures in particular for an improved flame propagation and thus for a fast combustion.

Advantageous are embodiments the injection nozzle, in which the electrodes of the at least one electrode pair in Area of the at least one nozzle opening formed arcuate are. This embodiment facilitates the arrangement of the electrodes in the area of the fuel injection jet, which consists of the at least a nozzle opening in Frame of injection exits.

A arcuate Design of the electrodes makes it easier, the spark gap a essentially similar To give alignment like the fuel injection jet that off a side nozzle opening emerges.

Embodiments of the injection nozzle in which the at least one anode is made are advantageous an anode sleeve surrounding the nozzle needle guide is formed.

Advantageous are further embodiments the injection nozzle, in which the at least one cathode of a surrounding the nozzle needle guide cathode sleeve is trained.

The sleeve-shaped training the electrodes facilitates the wiring of the injection valve according to the invention. For example, it is sufficient for the anode sleeve to the high voltage source to join, to over all from the anode sleeve resulting anodes the high voltage d. H. the ignition energy initiate. Furthermore, the sleeve shape offers advantages in the production and assembly, especially in positioning and fastening the electrodes in relation to the nozzle openings.

there can be a positioning of the electrodes by providing paragraphs and Grooves on or in the sleeve respectively. Thus, by means of paragraphs the Position of the anode and cathode sleeves along the longitudinal axis the injector be determined and thus, to what extent the electrodes in the combustion chamber or over the nozzle tip into the combustion chamber. Grooves in the exterior or palm the pods, in the direction of the longitudinal axis the injector run, can for aligning the electrodes with respect to the lateral nozzle openings serve and above to align the cathodes with the anodes. In addition, such Slots take over the tasks of a rotation. The grooves and clearances between the sleeves can in a sintering and / or injection molding process with an insulating compound, preferably a ceramic insulation material to be filled.

Advantageous are embodiments the injection nozzle, where the cathode sleeve outside or within the anode sleeve is arranged. These are embodiments the injector advantageous in which between the cathode sleeve and the anode sleeve a Insulation is provided, the insulation preferably also as a sleeve is trained. The cathode sleeve may be on its outer surface with a screw head with which the injection nozzle according to the invention in the cylinder head and / or be bolted to another suitable position in the combustion chamber, be equipped.

In the following the invention with reference to an embodiment of the injection nozzle according to the 1 and 2 described in more detail. Hereby shows:

1 schematically an embodiment of the injection nozzle in cross-section along the longitudinal axis of the injection nozzle, and

2 schematically the in 1 illustrated injection nozzle in the perspective view.

1 shows schematically an embodiment of the injection nozzle 1 in cross-section along the longitudinal axis 15 the injector 1 , The illustrated injection nozzle 1 is used for - one or more times per working cycle - injection of fuel into a cylinder of a direct-injection internal combustion engine and the subsequent ignition of the injected fuel. The fuel is via a fuel supply line 10 fed.

The injector 1 includes a nozzle needle 7 placed in a cylindrical nozzle needle guide 11 in the direction of the longitudinal axis 15 the injector 1 is slidably mounted. The nozzle needle 7 can - be moved by means of an actuator (not shown) - between a rest position and a working position.

At the in 1 shown snapshot is the nozzle needle 7 in the rest position, in which the nozzle needle 7 the nozzle openings provided at the nozzle tip 5 closes, so that no fuel can get into the cylinder of the internal combustion engine. One above the nozzle needle 7 arranged nozzle spring 8th acts on the nozzle needle 7 with a spring force, which is the needle 7 along the longitudinal axis 15 in the direction of rest position, ie in the direction of the closed position. In the working position, however, gives the nozzle needle 7 the nozzle openings 5 free to inject the fuel.

In the 1 illustrated injection nozzle 1 is with five nozzle openings 5 equipped, with a centrally located nozzle opening 5 and four lateral nozzle openings 5 are provided. The from the centrally located nozzle opening 5 emerging conical fuel jet 17 runs parallel to the longitudinal axis 15 the injector 1 and aims at the piston head if the nozzle 1 For example, is installed in the manner in the cylinder of the internal combustion engine, that the longitudinal axis 15 the injector 1 coincides with the longitudinal axis of the cylinder.

The fuel jets 17 coming from the side nozzle openings 5 emerge, lying on the lateral surface of an imaginary cone whose axis through the longitudinal axis 15 the injector 1 is formed. The cone opening angle γ is approximately 75 °, ie γ≈75 °.

The lateral nozzle openings 5 are there - evenly spaced apart - on one about the longitudinal axis 15 arranged concentrically running circle.

In order to electrically isolate the components relating to the injection of the fuel from the components provided for the purpose of ignition, is a first insulation 9 provided, which the nozzle needle guide 11 surrounds.

For each of the four lateral nozzle openings 5 is a pair of electrodes 2a . 2 B . 2d arranged in the injection area. Ie. it is for every single fuel spray 17 that the injector 1 through a lateral nozzle opening 5 leaves, provided a separate ignition device or ignition, whereby the ignition of the fuel-air mixture is made at several points in the combustion chamber.

The electrodes 3a . 3b . 3d . 4a . 4b . 4d are in the area of the lateral nozzle opening 5 arcuate to the in the course of the spark ignition between the electrodes 3a . 3b . 3d . 4a . 4b . 4d trained spark gaps 12 to give substantially the same orientation as that from the side nozzle openings 5 as part of the injection emerging fuel injection jets 17 exhibit. At the in 1 illustrated embodiment, the spark gaps 12 parallel to the injection jets 17 ie α ≈ 0 °.

Both the anodes 4a . 4b . 4d as well as the cathodes 3a . 3b . 3d are as a sleeve 13 . 14 formed, which the nozzle needle guide 11 surround. Ie. the anodes 4a . 4b . 4d or cathodes 3a . 3b . 3d run to a pod 13 . 14 together or form arcuate spaced webs, of a sleeve 13 . 14 protrude.

The cathode sleeve 13 is outside the anode sleeve 14 arranged between the cathode sleeve 13 and anode sleeve 14 an insulation 6 is provided to the two sleeves 13 . 14 from each other and thus the anodes 4a . 4b . 4d opposite the cathodes 3a . 3b . 3d electrically isolate. The insulation 6 is in its upper part as insulating sleeve 16 educated.

2 schematically shows the in 1 illustrated injection nozzle 1 in the perspective view. At this point, it should only supplement the already described 1 For that reason, reference is otherwise made to the description of FIG 1 , The same reference numerals have been used for the same components.

From the perspective view of the injector 1 It can be seen that in the course of ignition between the electrodes 3a . 4a - Which the first pair of electrodes 2a make - training spark gap 12 has substantially the same orientation as that of the associated side nozzle opening 5 exiting fuel injection jet 17 ,

In addition, the spark gap 12 and the fuel injection jet 17 spatially arranged one another, ie the first pair of electrodes 2a lies in the area of the fuel injection jet 17 coming from the associated side nozzle opening 5 exit. The spark gap 12 Aligns with the one from a nozzle opening 5 exiting fuel injection jet 17 why the fuel injection jet 17 on the two electrodes 3a . 4a aims. This is based on the first electrode pair 2a The same applies accordingly to the three remaining pairs of electrodes 2 B . 2c . 2d ,

The four electrode pairs provided 2a . 2 B . 2c . 2d are evenly spaced on concentric spherical surface around the longitudinal axis 15 the nozzle needle 7 or the injection nozzle 1 arranged around, wherein the anodes 4a . 4b . 4c . 4d on a sphere of smaller diameter and the cathodes 3a . 3b . 3c . 3d lie on a larger diameter ball.

From the perspective view is also apparent that the anode sleeve 14 at the top with a flange - for a in 2 not shown - screw thread is equipped and the cathode sleeve 13 was designed as a hexagon nut. The injection nozzle is screwed with the hexagon nut. The screw thread of the anode is used to make electrical contact with the ignition coil (s) by means of a conductive nut and washer on which the ignition cables terminate.

1

injection

2a

electrode pair

2 B

electrode pair

2c

electrode pair

2d

electrode pair

3a

cathode

3b

cathode

3c

cathode

3d

cathode

4a

anode

4b

anode

4c

anode

4d

anode

5

nozzle opening

6

insulation

7

nozzle needle

8th

nozzle spring

9

first insulation

10

Fuel supply line

11

Nozzle needle guide

12

radio link

13

cathode sleeve

14

anode sleeve

15

longitudinal axis the injection nozzle, Longitudinal axis of nozzle needle

16

insulating sleeve

17

Fuel injection jet

α

angle between spark gap and fuel injection jet

γ

Cone angle

Claims (14)

Injector ( 1 ), in particular for the injection of fuel into a cylinder of a direct-injection spark-ignited internal combustion engine, having - at least one nozzle opening ( 5 ) for feeding the fuel into the cylinder, - one in the direction of the longitudinal axis ( 15 ) of the injection nozzle ( 1 ) between a rest position and a working position in a nozzle needle guide ( 11 ) displaceable nozzle needle ( 7 ), wherein the nozzle needle ( 7 ) the at least one nozzle opening ( 5 ) in the rest position and releases in the working position for injection of the fuel, - the nozzle needle guide ( 11 ) surrounding first insulation ( 9 ), and - at least one pair of electrodes ( 2a . 2 B . 2c . 2d ), the two electrically isolated and spaced electrodes ( 3a . 3b . 3c . 3d . 4a . 4b . 4c . 4d ), wherein the first electrode ( 4a . 4b . 4c . 4d ) as an anode ( 4a . 4b . 4c . 4d ) and the second electrode ( 3a . 3b . 3c . 3d ) as a cathode ( 3a . 3b . 3c . 3d ) and the electrode pair ( 2a . 2 B . 2c . 2d ) spaced from the at least one nozzle opening ( 5 ), characterized in that - the at least one pair of electrodes ( 2a . 2 B . 2c . 2d ) is arranged in such a way that between the pair of electrodes ( 2a . 2 B . 2c . 2d ) forming electrodes ( 3a . 3b . 3c . 3d . 4a . 4b . 4c . 4d ) in the course of the spark ignition spark gap ( 12 ) substantially the orientation of one of a nozzle opening ( 5 ) in the context of the injection emerging conical fuel injection jet ( 17 ) having. Injector ( 1 ) according to claim 1, characterized in that the at least one pair of electrodes ( 2a . 2 B . 2c . 2d ) in the area of the fuel injection jet ( 17 ), which from the at least one nozzle opening ( 5 ) emerges during the injection. Injector ( 1 ) according to claim 1 or 2, characterized in that a centrally disposed nozzle opening ( 5 ) is provided, one from this nozzle opening ( 5 ) in the context of injection emerging fuel jet ( 17 ) parallel to the longitudinal axis ( 15 ) of the injection nozzle ( 1 ) runs. Injector ( 1 ) according to one of the preceding claims, characterized in that at least two lateral nozzle openings ( 5 ) are provided, which from these nozzle openings ( 5 ) in the context of the injection emerging fuel jets ( 17 ) lie on the lateral surface of an imaginary cone and the longitudinal axis ( 15 ) of the injection nozzle ( 1 ) forms the axis of this imaginary cone. Injector ( 1 ) according to one of the preceding claims, characterized in that a centrally arranged nozzle opening ( 5 ) and four lateral nozzle openings ( 5 ) are provided. Injector ( 1 ) according to claim 4 or 5, characterized in that the imaginary cone has a cone opening angle γ with 45 ° <γ <135 °. Injector ( 1 ) according to claim 4 or 5, characterized in that the imaginary cone has a cone opening angle γ with 60 ° <γ <120 °. Injector ( 1 ) according to claim 4 or 5, characterized in that the imaginary cone has a cone opening angle γ with 75 ° <γ <105 °. Injector ( 1 ) according to one of claims 4 to 8, characterized in that for each lateral nozzle opening ( 5 ) a pair of electrodes ( 2a . 2 B . 2c . 2d ) is provided. Injector ( 1 ) according to one of the preceding claims, characterized in that the electrodes ( 3a . 3b . 3c . 3d . 4a . 4b . 4c . 4d ) of the at least one electrode pair ( 2a . 2 B . 2c . 2d ) in the region of the at least one nozzle opening ( 5 ) are arcuate. Injector ( 1 ) according to one of the preceding claims, characterized in that the at least one anode ( 4a . 4b . 4c . 4d ) from a nozzle needle guide ( 11 ) surrounding anode sleeve ( 14 ) is trained. Injector ( 1 ) according to one of the preceding claims, characterized in that the at least one cathode ( 3a . 3b . 3c . 3d ) from a nozzle needle guide ( 11 ) surrounding cathode sleeve ( 13 ) is trained. Injector ( 1 ) according to claim 12 when appended to claim 11, characterized in that the cathode sleeve ( 13 ) outside or inside the anode sleeve ( 14 ) is arranged. Injector ( 1 ) according to claim 13, characterized characterized in that between the cathode sleeve ( 13 ) and anode sleeve ( 14 ) an insulation ( 16 ) is provided.