EP0148837B1 - Device for injecting fuel into a secondary flow of combustion air in a combustion chamber - Google Patents

Device for injecting fuel into a secondary flow of combustion air in a combustion chamber Download PDF

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Publication number
EP0148837B1
EP0148837B1 EP84900267A EP84900267A EP0148837B1 EP 0148837 B1 EP0148837 B1 EP 0148837B1 EP 84900267 A EP84900267 A EP 84900267A EP 84900267 A EP84900267 A EP 84900267A EP 0148837 B1 EP0148837 B1 EP 0148837B1
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EP
European Patent Office
Prior art keywords
openings
nozzle
combustion
combustion chamber
fuel
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EP84900267A
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German (de)
French (fr)
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EP0148837A1 (en
Inventor
Thomas Frey
Werner Grünwald
Ernst Imhof
Iwan Komaroff
Helmut Reum
Günther Schmid
Kurt Schmid
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Robert Bosch GmbH
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Robert Bosch GmbH
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Priority to AT84900267T priority Critical patent/ATE33169T1/en
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Publication of EP0148837B1 publication Critical patent/EP0148837B1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M53/00—Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
    • F02M53/04—Injectors with heating, cooling, or thermally-insulating means
    • F02M53/06—Injectors with heating, cooling, or thermally-insulating means with fuel-heating means, e.g. for vaporising
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for

Definitions

  • the invention relates to a device for injecting fuel according to the preamble of the main claim.
  • a heating chamber is arranged between the spray opening of the fuel injection nozzle and the passage opening in the partition between the nozzle and the combustion chamber, in which the heating device is arranged coaxially with the defined fuel jet.
  • a negative pressure is created in this heating chamber due to the water jet pump effect, as long as the injection takes place.
  • the pressure in this chamber can drop significantly below the ambient air pressure.
  • gas flows from the combustion chamber into the heating chamber due to the pressure difference.
  • this known device also has the disadvantage in continuous injection systems, for example for heating combustion rooms, that the negative pressure which arises in the heating chamber cannot be compensated for. This inevitably draws air past the spray jet past the spray jet into the heating chamber, which has a disadvantageous effect on the jet direction, jet shape and jet speed of the fuel jet. The fuel jet flutters and is usually pushed in on one side. It loses speed and is poorly distributed in the combustion chamber. This leads to increased soot emissions and reduced energy yield.
  • a cylinder tube is attached to the end of an injection nozzle on the combustion chamber side and forms a combustion or evaporation chamber directly downstream of the spray opening, in which the combustion chamber is in the form a conical spray is already ignited.
  • the cylinder tube is provided with lateral openings for supplying combustion air into the combustion or evaporation space enclosed by it, which is guided along the outside of the cylinder tube and thereby heats up on the cylinder tube, which acts as a passive heating element.
  • the spray jets of which have at least approximately a jet geometry symmetrical with respect to the nozzle axis and the injection nozzle of which is followed by an electrically heated incandescent body which has an axial passage for the spray jets and with the side opening into the passage is provided, through which the spray jets suck combustion air from the combustion chamber through an annular space surrounding the glow body.
  • the combustion air drawn in and heated on the incandescent body penetrates into the peripheral zones of the spray jets, which considerably increases the ignitability of the spray jets.
  • the device according to the invention with the characterizing features of the main claim has the advantage that combustion air circulates almost continuously via the bypass, which is heated by the heating device arranged there. Even if the fuel injection works intermittently, the fuel jet never acts against the flow of combustion air in the bypass, but rather only drives it. At higher speeds and a correspondingly higher injection frequency, the speed of the air flow through the bypass also increases comparatively, so that there is also a correspondingly higher heating output. Due to the largely uniform heating of the volume resulting from the speed, on the one hand a much more uniform combustion process and on the other hand an improvement in the emission can be achieved. Another essential The advantage is that primarily the combustion air flowing through the bypass is heated and the heating device does not act directly on the fuel.
  • the device according to the invention has an advantageous effect particularly in modern internal combustion engines with their combustion chambers optimized with regard to flow dynamics.
  • it does not offer any disadvantage in terms of flow technology, but rather can be planned into that of the combustion chambers by the designer using the flow function that has been input to it, as a result of which the flow characteristics of the combustion chamber can be improved.
  • the heating element on the air guiding device ensures that the heating device is always at the most favorable heating effect provided by the designer, namely where the heating surfaces are optimally coated due to known flow conditions.
  • the device according to the invention manages with relatively low electrical energy and can therefore be used in continuous operation.
  • a heat insulation layer or a protective plate that dissipates the hot air can serve as a heat-protecting agent.
  • the partition wall can advantageously be arranged on the nozzle clamping nut.
  • the nozzle clamping nut is fixed in its position in relation to the fuel injection nozzle and thus to the combustion chamber, so that the air guiding device is also fixed accordingly.
  • a preferred area of application for the invention is the diesel engine, and the exemplary embodiments described below relate to use in such a self-igniting internal combustion engine. All three exemplary embodiments are arranged directly on the fuel injection nozzle of the diesel engine, one of which is also shown in FIG. 1, for example.
  • a nozzle body 1 is clamped via a nozzle clamping nut 2 to a nozzle holder 3 which is connected to an injection pump by fuel lines, not shown.
  • the fuel supplied intermittently by the injection pump passes through a pressure channel 4 into a pressure chamber 5 of the nozzle body 1 and shifts a valve needle 7 in the opening direction against the force of the closing spring 6.
  • the pressure chamber 5 becomes a blind hole 9 connected, branch off from the spray openings 11 arranged in a nozzle tip 10.
  • FIG. 2 shows this injection part of the fuel injection nozzle of the first exemplary embodiment shown in FIG. 1 on an enlarged scale.
  • the nozzle clamping nut has a tubular section 12, which runs coaxially to the injection nozzle axis and in which through openings 13 are provided for the fuel jet formed via the spray openings 11.
  • the spray openings 11 and the associated through openings 13 are axially aligned. Since the tubular section 12 of the nozzle clamping nut 2 forms a partition between the fuel injection nozzle and there specifically the crest 10 and the combustion chamber 14 located outside this pipe section 12, the fuel jet must be able to pass through the through opening 13 unhindered.
  • the fuel / air mixture then forms in the combustion chamber 14 in a conventional manner and ignites itself if the compression is sufficient.
  • a heating coil 16 is arranged in this tube space 15, coaxially with the tube section 12, which is supplied with electrical energy via the cable 17 shown in FIG. 1 and is grounded at its end 18 via the nozzle tip 10 is.
  • the air flowing from the combustion chamber 14 into the heating chamber 15 can be heated accordingly before it comes into contact with the fuel jet.
  • the pump effect caused by the jet energy also ensures that this warmed-up air is mixed with the fuel jet and thus, in addition to the heating of the fuel-air mixture, for its intensive mixing and preparation.
  • This heating and conditioning of the fuel / air mixture not only improves ignition, but also reduces the amount of soot in the exhaust gas, since more complete combustion of the hydrocarbons is possible.
  • the combustion air flowing in via the heating chamber 15 can have or maintain a considerable temperature, so that the tip of the nozzle could possibly be endangered by overheating.
  • a heat protection 19 is arranged transversely to the flow direction on the dome 10 of the nozzle body 1, the end face of which is provided with a heat-insulating layer 20 toward the flow side. The heated by the heating coil 16 air flow in the bypass 15 is passed through the heat protection 19 to the outside and thus to the through openings 13, so that overheating of the actual tip 10 and thus the spray openings 11 or even the blind hole 9 is avoided.
  • a thermal shield 21 is attached to the summit 10 "', which has the same function as the thermal protection 19 described above, but is relatively easy to attach to standard perforated nozzles, for example by welding.
  • the tubular section 12 ′ has a funnel-shaped extension 23 towards the combustion chamber 14.
  • the input of the bypass is expanded accordingly, so that air is drawn in from a wider zone of the combustion chamber 14.
  • This air sweeps over a heating conductor 24, which is arranged on the inside of the funnel 23.
  • the air then enters the cylindrical section of the air guiding device 12 ′ in order to then flow back into the combustion chamber 14 via the fuel jet and the through openings 13.
  • Thermal protection is provided on the dome 10 'of the nozzle body 1' of this exemplary embodiment, which is cylindrical, on the end face opposite the flow. 4 shows two variants of this thermal protection, one on the left and one on the right of the central axis.
  • the variant on the right is a tube 25 which is placed on the nozzle tip 10 'and serves to guide the air, which protrudes a little further into the funnel 23 and, together with it, delimits a partially conical ring channel 26 which serves as a bypass. Otherwise, the heated air is drawn to the through openings 13 by the fuel jet before it can reach spray openings 11.
  • thermo insulation layer 27 with a corresponding effect.
  • a conical heating coil is arranged in a funnel - shaped air bypass tube which forms the bypass for heating the air
  • heating conductors are provided on the inside walls of a corresponding cylindrical bypass tube.
  • a tube with heat conducting surfaces is preferably arranged coaxially in the tube or funnel. All of these conceivable possibilities are covered by the invention, but are to be considered less preferred than the examples shown, in particular because of the production costs.
  • a third embodiment is shown, in which the air drawn in from the combustion chamber 14 flows transversely to the nozzle axis to the fuel jets. Since the fuel jets are also sprayed transversely to the injector axis even in this exemplary embodiment, which is also about a perforated nozzle, the air inlet and outlet largely take place in a plane transverse to the injector axis.
  • an air guiding device in the form of a dome-like hood 29 is arranged above the dome 10 "of the nozzle body 1", but essentially follows the shape of the dome 10 "with a larger diameter. Between dome 10 "and this hood 29 is created as Bypass a hemispherical annular space 30, from which then branch off the corresponding through openings and inlet openings arranged in the hood. Elongated openings 31, which are arranged in a plane and centrally symmetrically, serve as input openings. The plane corresponds to the sectional plane VI-VI from FIG. 5, as shown in FIG. 6.
  • the through openings 13 ′′ assigned to these spray openings are also arranged in this plane in accordance with a part of the spray openings 11 ′′. Further through openings 13 "are in turn arranged coaxially with further spray openings 11", this common axis enclosing a certain angle with the plane mentioned.
  • the combustion air is heated via heating conductors 32, which are arranged on the outer circumferential surface of the hood 29 in such a way that they are captured by the inflowing air as far as possible. Since the air enters transversely to the nozzle axis here, on the one hand the conical hood section 33 is occupied and on the other hand a part of the spherical area 29 near the inlet openings 31.
  • the heating enables two heating stages, which can be switched on either alternatively or in parallel.
  • a stronger heating output could be used during a cold start and a weaker, for example continuous one, as permanent heating to improve the combustion process.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Pressure-Spray And Ultrasonic-Wave- Spray Burners (AREA)

Abstract

PCT No. PCT/DE83/00212 Sec. 371 Date Dec. 18, 1984 Sec. 102(e) Date Dec. 18, 1984 PCT Filed Dec. 20, 1983 PCT Pub. No. WO84/04359 PCT Pub. Date Nov. 8, 1984.An apparatus for injecting fuel into the combustion chamber of an internal combustion engine, having an injection nozzle and following the injection nozzle a partition (12, 23, 29) which is provided with through openings (13) for the injection streams and is embodied as a guide device for a partial flow of combustion air, which flow is accelerated by the injector action of the fuel streams in the through openings (13). A device (26, 24, 32) for preheating the partial flow of combustion air is also secured to the partition (12, 23, 29). In this apparatus, the partial flow of combustion air circulates virtually continuously through the partition (12, 23, 29) embodied as a guide device, and the acceleration caused by the injector action of the fuel streams increases with increasing engine rpm. This has the advantage that over the entire power and rpm range of the engine, a uniform course of combustion and a reduction of toxic emissions is attainable.

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Einrichtung zum Einspritzen von Kraftstoff nach der Gattung des Hauptanspruchs. Bei einer bekannten Einrichtung dieser Art (FR-A-1 382 697 Fig. 5) ist zwischen Spritzöffnung der Kraftstoffeinspritzdüse und der Durchgangsöffnung in der Trennwand zwischen Düse und Brennkammer ein Heizraum angeordnet, in dem koaxial zum definierten Kraftstoffstrahl die Heizvorrichtung angeordnet ist. An der Durchgangsstelle des Kraftstoffstrahles durch die Durchgangsöffnung entsteht aufgrund des Wasserstrahlpumpeneffektes in dieser Heizkammer, solange eingespritzt wird, ein Unterdruck. Der Druck in dieser Kammer kann dabei erheblich unter den Umgebungsluftdruck sinken. Sobald dann die Einspritzung unterbrochen wird, strömt aufgrund des Druckunterschieds Gas aus der Brennkammer in die Heizkammer. Bei der Einspritzung von Brennkraftmaschinen ist die Taktzahl der intermittierenden Einspritzung abhängig von der Drehzahl, so daß bei hohen Drehzahlen der Druckausgleich der beiden Kammern noch nicht erreicht ist, bevor die neuerliche Einspritzung beginnt. Dieses sich Begegnen von Kraftstoffstrom und Gasstrom hat zwar eine intensive Durchmischung von Kraftstoff und Gas (Luft) zur Folge, hat jedoch den Nachteil, daß sich dieses Kraftstoffluftgemisch in seinen Anteilen an Kraftstoff bzw. Luft drehzahlabhängig ändert. Ein normalerweise angestrebtes, von der Drehzahl weitgehend unabhängiges und zündgerechtes Kraftstoffluftgemisch ist somit nicht erzielbar. Es besteht sogar die Gefahr, daß völlig unkontrolliert in gewissen Drehzahlbereichen Frühzündungen oder Spätzündungen erfolgen, was bei selbstzündenden Brennkraftmaschinen auf Kosten der Leistung und einer günstigen Emission geht.The invention relates to a device for injecting fuel according to the preamble of the main claim. In a known device of this type (FR-A-1 382 697 Fig. 5), a heating chamber is arranged between the spray opening of the fuel injection nozzle and the passage opening in the partition between the nozzle and the combustion chamber, in which the heating device is arranged coaxially with the defined fuel jet. At the point of passage of the fuel jet through the passage opening, a negative pressure is created in this heating chamber due to the water jet pump effect, as long as the injection takes place. The pressure in this chamber can drop significantly below the ambient air pressure. As soon as the injection is interrupted, gas flows from the combustion chamber into the heating chamber due to the pressure difference. In the injection of internal combustion engines, the number of cycles of the intermittent injection depends on the speed, so that at high speeds the pressure compensation of the two chambers has not yet been reached before the new injection begins. This encounter of fuel flow and gas flow does result in an intensive mixing of fuel and gas (air), but has the disadvantage that this fuel-air mixture changes in its proportions of fuel and air depending on the speed. A normally desired, ignitable fuel-air mixture that is largely independent of the speed cannot be achieved. There is even the danger that pre-ignition or late ignition will occur completely uncontrolled in certain speed ranges, which in the case of self-igniting internal combustion engines comes at the expense of performance and a favorable emission.

Ein weiterer Nachteil dieser bekannten Einrichtung besteht darin, daß die Heizstrahlung der Heizvorrichtung unmittelbar den Kraftstoffstrahl trifft, so daß an dessen Oberfläche eine Überhitzung eintritt, die in Verbindung mit dem hier zumindest zeitweise vorhandenen Sauerstoff zu einer teilweisen Vorverbrennung führt. Dieser Vorverbrennung schließt sich später dann die Hauptverbrennung an, deren Effizienz von der Qualität der Aufbereitung des Kraftstoffluftgemisches abhängt. Diese Qualität kann jedoch nur dann über den ganzen Drehzahlbereich in gewünschtem Maße aufrecht erhalten werden, wenn auch die oben beschriebene Vorverbrennung über den ganzen Drehzahlbereich konstant ist.Another disadvantage of this known device is that the heating radiation of the heating device strikes the fuel jet directly, so that overheating occurs on its surface, which leads to partial pre-combustion in connection with the oxygen present here at least at times. This pre-combustion is then followed by the main combustion, the efficiency of which depends on the quality of the preparation of the fuel-air mixture. However, this quality can only be maintained to the desired extent over the entire speed range if the pre-combustion described above is constant over the entire speed range.

Nicht zuletzt hat diese bekannte Einrichtung auch bei kontinuierlichen Einspritzanlagen, beispielsweise für Heizungsbrennräume, den Nachteil, daß der in der Heizkammer entstehende Unterdruck nicht kompensiert werden kann. Hierdurch wird zwangsläufig Luft entgegen der Spritzstrahlrichtung am Spritzstrahl vorbei in die Heizkammer gesogen, was sich nachteilig auf Strahlrichtung, Strahlform und Strahlgeschwindigkeit des Kraftstoffstrahles auswirkt. Der Kraftstoffstrahl flattert und wird meist einseitig eingedrückt. Er verliert an Geschwindigkeit und wird schlecht in der Brennkammer verteilt. Das führt zu vermehrter Rußemission und zu verminderter Energieausbeute.Last but not least, this known device also has the disadvantage in continuous injection systems, for example for heating combustion rooms, that the negative pressure which arises in the heating chamber cannot be compensated for. This inevitably draws air past the spray jet past the spray jet into the heating chamber, which has a disadvantageous effect on the jet direction, jet shape and jet speed of the fuel jet. The fuel jet flutters and is usually pushed in on one side. It loses speed and is poorly distributed in the combustion chamber. This leads to increased soot emissions and reduced energy yield.

Bei einer anderen bekannten Einrichtung zum Einspritzen von Kraftstoff in eine Brennkammer einer Brennkraftmaschine (US-A 1 693 931) ist am brennkammerseitigen Stirnende einer Einspritzdüse ein Zylinderrohr befestigt, das einen der Spritzöffnung unmittelbar nachgeschalteten Brenn- bzw. Verdampfungsraum bildet, in welchem der in Form eines konischen Sprühstrahles ausgespritzte Kraftstoff bereits gezündet wird. Das Zylinderrohr ist mit seitlichen Öffnungen zum Zuführen von Verbrennungsluft in den von ihm umschlossenen Brenn- bzw. Verdampfungsraum versehen, welche außen am Zylinderrohr entlang geführt wird und sich dabei an dem als passives Heizelement wirkenden Zylinderrohr erwärmt.In another known device for injecting fuel into a combustion chamber of an internal combustion engine (US-A 1 693 931), a cylinder tube is attached to the end of an injection nozzle on the combustion chamber side and forms a combustion or evaporation chamber directly downstream of the spray opening, in which the combustion chamber is in the form a conical spray is already ignited. The cylinder tube is provided with lateral openings for supplying combustion air into the combustion or evaporation space enclosed by it, which is guided along the outside of the cylinder tube and thereby heats up on the cylinder tube, which acts as a passive heating element.

Aus der nicht vorveröffentlichten EP-A 0 102 507 sind ferner Einrichtungen zum Einspritzen von Kraftstoff bekannt, deren Spritzstrahlen mindestens annähernd eine zur Düsenachse symmetrische Strahlgeometrie haben und deren Einspritzdüse ein elektrisch beheizter Glühkörper nachgeschaltet ist, der mit einem axialen Durchgang für die Spritzstrahlen und mit von der Seite her in den Durchgang einmündenden Öffnungen versehen ist, durch welche die Spritzstrahlen Verbrennungsluft aus der Brennkammer über einen den Glühkörper umgebenden Ringraum ansaugen. Dabei dringt die angesaugte und am Glühkörper erwärmte Verbrennungsluft in die Randzonen der Spritzstrahlen ein, wodurch die Zündwilligkeit der Spritzstrahlen wesentlich erhöht wird.From the unpublished EP-A 0 102 507 devices for injecting fuel are also known, the spray jets of which have at least approximately a jet geometry symmetrical with respect to the nozzle axis and the injection nozzle of which is followed by an electrically heated incandescent body which has an axial passage for the spray jets and with the side opening into the passage is provided, through which the spray jets suck combustion air from the combustion chamber through an annular space surrounding the glow body. The combustion air drawn in and heated on the incandescent body penetrates into the peripheral zones of the spray jets, which considerably increases the ignitability of the spray jets.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Einrichtung mit den kennzeichnenden Merkmalen des Hauptanspruchs hat den Vorteil, daß über den Bypass nahezu kontinuierlich Verbrennungsluft zirkuliert, die durch die dort angeordnete Heizvorrichtung aufgeheizt wird. Auch wenn die Kraftstoffeinspritzung intermittierend arbeitet, so wirkt der Kraftstoffstrahl niemals gegen die Strömung der Verbrennungsluft im Bypass, sondern er bewirkt lediglich einen Antrieb derselben. Bei höheren Drehzahlen und einer entsprechend höheren Einspritzfrequenz nimmt vergleichsweise auch die Geschwindigkeit der Luftströmung durch den Bypass zu, so daß auch eine entsprechend höhere Heizleistung gegeben ist. Aufgrund der über der Drehzahl sich damit ergebenden weitgehend gleichmäßigen Aufheizung des Volumens ist einerseits ein wesentlich gleichmäßigerer Verbrennungsablauf und andererseits eine Verbesserung der Emission erzielbar. Ein wesentlicher weiterer Vorteil besteht darin, daß in erster Linie die Verbrennungsluft, die den Bypass durchströmt, aufgeheizt wird und die Heizvorrichtung nicht unmittelbar auf den Kraftstoff wirkt. Hierdurch werden nachteilige Verkokungen vermieden, sowie über der Drehzahl ungleichmäßige Teilverbrennungen. Besonders bei modernen Brennkraftmaschinen mit ihren bezüglich der Strömungsdynamik optimierten Brennkammern wirkt sich die erfindungsgemäße Einrichtung vorteilhaft aus. Im Gegensatz zu den bekannten Einrichtungen bietet sie keinen strömungstechnischen Nachteil, sondern läßt sich mit der ihr eingegebenen Strömungsfunktion durch den Konstrukteur in diejenige der Brennkammern einplanen, wodurch sich die Strömungskenngrößen der Brennkammer verbessern lassen. Je nach Lage des Eingangs des Bypasses wird unmittelbar Einfluß auf die Brenkammerströmung genommen. Durch Anordnung des Heizelements an der Luftleitvorrichtung ist gewährleistet, daß die Heizvorrichtung sich immer an der vom Konstrukteur vorgesehenen Stelle günstigster Heizwirkung befindet, nämlich wo aufgrund bekannter Strömungsverhältnisse die Heizflächen optimal bestrichen werden. Aufgrund der sich bei der Strömung ergebenden Verwirbelung wird die stromauf des Kraftstoffeintritts strömende Luft wirkungsvoll aufgeheizt, bevor sie mit dem kühleren Kraftstoffstrahl in Berührung kommt. Die Durchmischung wird stromab der Durchgangsöffnung verstärkt, so daß vor Zündung ein weitgehend homogenes und fettes Kraftstoffluftgemisch zur Verfügung steht. Die erfindungsgemäße Einrichtung kommt mit verhältnismäßig geringer elektrischer Energie aus und kann somit im Dauerbetrieb eingesetzt werden.The device according to the invention with the characterizing features of the main claim has the advantage that combustion air circulates almost continuously via the bypass, which is heated by the heating device arranged there. Even if the fuel injection works intermittently, the fuel jet never acts against the flow of combustion air in the bypass, but rather only drives it. At higher speeds and a correspondingly higher injection frequency, the speed of the air flow through the bypass also increases comparatively, so that there is also a correspondingly higher heating output. Due to the largely uniform heating of the volume resulting from the speed, on the one hand a much more uniform combustion process and on the other hand an improvement in the emission can be achieved. Another essential The advantage is that primarily the combustion air flowing through the bypass is heated and the heating device does not act directly on the fuel. In this way, disadvantageous coking is avoided, as are partial burns which are uneven over the speed. The device according to the invention has an advantageous effect particularly in modern internal combustion engines with their combustion chambers optimized with regard to flow dynamics. In contrast to the known devices, it does not offer any disadvantage in terms of flow technology, but rather can be planned into that of the combustion chambers by the designer using the flow function that has been input to it, as a result of which the flow characteristics of the combustion chamber can be improved. Depending on the position of the inlet of the bypass, there is an immediate influence on the brine chamber flow. Arranging the heating element on the air guiding device ensures that the heating device is always at the most favorable heating effect provided by the designer, namely where the heating surfaces are optimally coated due to known flow conditions. Due to the turbulence resulting from the flow, the air flowing upstream of the fuel inlet is effectively heated before it comes into contact with the cooler fuel jet. The mixing is strengthened downstream of the passage opening, so that a largely homogeneous and rich fuel-air mixture is available before ignition. The device according to the invention manages with relatively low electrical energy and can therefore be used in continuous operation.

. Durch die in den Ansprüchen 2 bis 12 aufgeführten Merkmale sind vorteilhafte Weiterbildungen der Anordnung nach Anspruch 1 möglich.. Due to the features listed in claims 2 to 12, advantageous developments of the arrangement according to claim 1 are possible.

Zum Schutz der Spritzöffnungen der Einspritzdüse vor zu starker Erwärmung wird vorgeschlagen, daß der aufgeheizten Verbrennungsluft ausgesetzte und Spritzöffnungen aufweisende Bereiche eines Düsenkörpers mit hitzeschützenden Mitteln versehen sind. Als hitzeschützendes Mittel kann eine Wärmedämmschicht oder ein die Heißluft ableitendes Schutzblech dienen.To protect the injection openings of the injection nozzle from excessive heating, it is proposed that areas of a nozzle body which are exposed to the heated combustion air and have injection openings are provided with heat-protecting means. A heat insulation layer or a protective plate that dissipates the hot air can serve as a heat-protecting agent.

Bei Einrichtungen mit einem Düsenkörper, der quer zur Längsachse der Einspritzdüse angeordnete Spritzöffnungen aufweist und durch eine Düsenspannmutter an einem Düsenhalter festgespannt ist, kann die Trennwand vorteilhaft an der Düsenspannmutter angeordnet sein. Die Düsenspannmutter ist in ihrer Lage zur Kraftstoffeinspritzdsüe und damit zur Brennkammer fixiert, so daß auch die Luftleitvorrichtung entsprechend fixiert ist. Während bei Zapfendüsen oder nach außen öffnenden Düsen die Durchgangsöffnung koaxial zur Einspritzdüsenachse verläuft, ist bei Lochdüsen eine exakte Zuordnung von Durchgangsöffnungen in der Luftleitvorrichtung und Spritzlöchern im Düsenkörper erforderlich, was bei der einteiligen Ausführung von Luftleitvorrichtung und Düsenspannmutter problemlos machbar ist.In devices with a nozzle body which has spray openings arranged transversely to the longitudinal axis of the injection nozzle and is clamped to a nozzle holder by a nozzle clamping nut, the partition wall can advantageously be arranged on the nozzle clamping nut. The nozzle clamping nut is fixed in its position in relation to the fuel injection nozzle and thus to the combustion chamber, so that the air guiding device is also fixed accordingly. While in the case of pintle nozzles or outward-opening nozzles, the through opening runs coaxially to the injection nozzle axis, in the case of perforated nozzles an exact assignment of through openings in the air guiding device and spray holes in the nozzle body is required, which is easily possible with the one-piece design of the air guiding device and nozzle clamping nut.

Zeichnungdrawing

Drei Ausführungsbeispiele des Gegenstandes der Erfindung sind in der Zeichnung dargestellt und in nachfolgender Beschreibung näher erläutert. Es zeigen :

  • Fig. 1 eine Kraftstoffeinspritzdüse im Längsschnitt, an der das erste Ausführungsbeispiel verwirklicht ist,
  • Fig. 2 einen Ausschnitt aus Fig. 1 des ersten Ausführungsbeispiels in vergrößertem Maßstab,
  • Fig. 3 eine Variante des Wärmeschutzes des ersten Ausführungsbeispiels,
  • Fig. 4 das zweite Ausführungsbeispiel im Längsschnitt mit einem trichterförmigen Lufteinlaß,
  • Fig. 5 das dritte Ausführungsbeispiel im Längsschnitt mit radialer Luftzuströmung und
  • Fig. 6 einen Schnitt gemäß der Linie VI-VI in Fig. 5.
Three embodiments of the object of the invention are shown in the drawing and explained in more detail in the following description. Show it :
  • 1 is a fuel injector in longitudinal section, on which the first embodiment is realized,
  • 2 shows a detail from FIG. 1 of the first embodiment on an enlarged scale,
  • 3 shows a variant of the thermal protection of the first exemplary embodiment,
  • 4 shows the second embodiment in longitudinal section with a funnel-shaped air inlet,
  • Fig. 5 shows the third embodiment in longitudinal section with radial air inflow and
  • 6 shows a section along the line VI-VI in FIG. 5.

Beschreibung der AusführungsbeispieleDescription of the embodiments

Ein bevorzugtes Anwendungsgebiet für die Erfindung ist der Dieselmotor und auch die nachfolgend beschriebenen Ausführungsbeispiele betreffen die Anwendung in einer derartigen selbstzündenden Brennkraftmaschine. Alle drei Ausführungsbeispiele sind unmittelbar an der Kraftstoffeinspritzdüse des Dieselmotors angeordnet, von denen auch beispielsweise eine in Fig. 1 dargestellt ist.A preferred area of application for the invention is the diesel engine, and the exemplary embodiments described below relate to use in such a self-igniting internal combustion engine. All three exemplary embodiments are arranged directly on the fuel injection nozzle of the diesel engine, one of which is also shown in FIG. 1, for example.

Ein Düsenkörper 1 ist über eine Düsenspannmutter 2 an einen Düsenhalter 3 gespannt, welcher durch nicht dargestellte Kraftstoffleitungen mit einer Einspritzpumpe verbunden ist. Der von der Einspritzpumpe intermittierend zugeführte Kraftstoff gelangt über einen Druckkanal 4 in einen Druckraum 5 des Düsenkörpers 1 und verschiebt in Öffnungsrichtung eine Ventilnadel 7 entgegen der Kraft der Schliessfeder 6. Nach Abheben der Ventilnadel 7 von einem Sitz 8 wird der Druckraum 5 mit einem Sackloch 9 verbunden, von dem in einer Düsenkuppe 10 angeordnete Spritzöffnungen 11 abzweigen.A nozzle body 1 is clamped via a nozzle clamping nut 2 to a nozzle holder 3 which is connected to an injection pump by fuel lines, not shown. The fuel supplied intermittently by the injection pump passes through a pressure channel 4 into a pressure chamber 5 of the nozzle body 1 and shifts a valve needle 7 in the opening direction against the force of the closing spring 6. After lifting the valve needle 7 from a seat 8, the pressure chamber 5 becomes a blind hole 9 connected, branch off from the spray openings 11 arranged in a nozzle tip 10.

In Fig. 2 ist dieser Abspritzteil der Kraftstoffeinspritzdüse des in Fig. 1 dargestellten ersten Ausführungsbeispiels in vergrößertem Maßstab dargestellt. Die Düsenspannmutter weist einen koaxial zur Einspritzdüsenachse verlaufenden rohrförmigen Abschnitt 12 auf, in dem Durchgangsöffnungen 13 für den über die Spritzöffnungen 11 gebildeten Kraftstoffstrahl vorgesehen sind. Die Spritzöffnungen 11 und die zugeordneten Durchgangsöffnungen 13 sind achsgleich. Da der rohrförmige Abschnitt 12 der Düsenspannmutter 2 eine Trennwand zwischen Kraftstoffeinspritzdüse und dort speziell der Kuppe 10 und dem außerhalb dieses Rohrabschnitts 12 gelegenen Brennraum 14 bildet, muß der Kraftstoffstrahl ungehindert die Durchgangsöffnung 13 passieren können. Im Brennraum 14 bildet sich dann in üblicher Weise das Kraftstoffluftgemisch, das bei ausreichender Verdichtung sich selbst entzündet. Aufgrund der sich im Bereich der Durchgangsöffnung 13 mit dem Kraftstoffstrahl bildenden Injektorwirkung wird aus dem vom Rohrabschnitt 12 eingeschlossenen Raum 15 Luft über die Durchgangsöffnungen 13 « herausgepumpt » und in die Brennkammer 14 gefördert, wobei ein Teil dieser Luft sich mit dem Kraftstoffstrahl vermischt. Infolge dieses Absaugens strömt über die offene Seite des Rohrabschnitts 12 Luft aus dem Brennraum 14 in diesen Rohrraum 15. Der Rohrraum 15 wirkt dabei als Bypass für eine gezielte Luftströmung, da auch im Brennraum 14 aufgrund der Kolbenarbeit des Motors und entsprechender Luftführungen in Brennkammer und Zylinder Strömungen entstehen. Je höher die Einspritzfrequenz ist, desto höher ist auch die Strömungsgeschwindigkeit im Bypass, sowie die durch diesen geförderte Luftmenge.FIG. 2 shows this injection part of the fuel injection nozzle of the first exemplary embodiment shown in FIG. 1 on an enlarged scale. The nozzle clamping nut has a tubular section 12, which runs coaxially to the injection nozzle axis and in which through openings 13 are provided for the fuel jet formed via the spray openings 11. The spray openings 11 and the associated through openings 13 are axially aligned. Since the tubular section 12 of the nozzle clamping nut 2 forms a partition between the fuel injection nozzle and there specifically the crest 10 and the combustion chamber 14 located outside this pipe section 12, the fuel jet must be able to pass through the through opening 13 unhindered. The fuel / air mixture then forms in the combustion chamber 14 in a conventional manner and ignites itself if the compression is sufficient. Due to the in the area of the passage opening 13 with the injector effect, air is "pumped out" from the space 15 enclosed by the pipe section 12 via the passage openings 13 and conveyed into the combustion chamber 14, a part of this air mixing with the fuel jet. As a result of this suction, air flows out of the combustion chamber 14 into this pipe chamber 15 via the open side of the pipe section 12. The pipe chamber 15 acts as a bypass for a targeted air flow, since also in the combustion chamber 14 due to the piston work of the engine and corresponding air ducts in the combustion chamber and cylinder Currents arise. The higher the injection frequency, the higher the flow rate in the bypass and the amount of air that it delivers.

Zur Aufwärmung der in den Bypass 15 eintretenden Luft ist in diesem Rohrraum 15 und zwar koaxial zum Rohrabschnitt 12 eine Heizwendel 16 angeordnet, die über das in Fig. 1 dargestellte Kabel 17 mit elektrischer Energie versorgt wird und mit ihrem Ende 18 über die Düsenkuppe 10 geerdet ist. Die aus dem Brennraum 14 in den Heizraum 15 strömende Luft kann entsprechend aufgeheizt werden, bevor sie mit dem Kraftstoffstrahl in Berührung kommt. Der durch die Strahlenergie bewirkte Pumpeffekt sorgt zudem für ein Vermischen dieser aufgewärmten Luft mit dem Kraftstoffstrahl und damit neben der Aufwärmung des Kraftstoffluftgemisches für dessen intensive Vermischung und Aufbereitung. Diese Erwärmung und Aufbereitung des Kraftstoffluftgemisches bewirkt nicht nur eine bessere Zündwilligkeit, sondern auch eine Abnahme der Rußanteile im Abgaß, da eine vollkommenere Verbrennung der Kohlenwasserstoffe möglich ist.To heat the air entering the bypass 15, a heating coil 16 is arranged in this tube space 15, coaxially with the tube section 12, which is supplied with electrical energy via the cable 17 shown in FIG. 1 and is grounded at its end 18 via the nozzle tip 10 is. The air flowing from the combustion chamber 14 into the heating chamber 15 can be heated accordingly before it comes into contact with the fuel jet. The pump effect caused by the jet energy also ensures that this warmed-up air is mixed with the fuel jet and thus, in addition to the heating of the fuel-air mixture, for its intensive mixing and preparation. This heating and conditioning of the fuel / air mixture not only improves ignition, but also reduces the amount of soot in the exhaust gas, since more complete combustion of the hydrocarbons is possible.

Die über die Heizkammer 15 einströmende Verbrennungsluft kann jedoch eine erhebliche Temperatur aufweisen oder erhalten, so daß gegebenenfalls die Düsenkuppe durch Überhitzung gefährdet sein könnte. Zudem besteht die Gefahr, daß aufgrund der hohen Temperaturen der Kraftstoff bereits in den Spritzöffnungen 11 verkokt und dadurch deren Durchgang entweder verengt, oder überhaupt sperrt. Aus diesem Grunde ist an der Kuppe 10 des Düsenkörpers 1 ein Hitzeschutz 19 quer zur Strömungsrichtung angeordnet, dessen Stirnseite zur Strömungsseite hin mit einer wärmedämmenden Schicht 20 versehen ist. Der durch die Heizwendel 16 aufgeheizte Luftstrom in dem Bypass 15 wird durch den Wärmeschutz 19 nach außen und damit zu den Durchgangsöffnungen 13 hingeleitet, so daß eine Überhitzung der eigentlichen Kuppe 10 und damit der Spritzöffnungen 11 oder gar des Sacklochs 9 vermieden wird.However, the combustion air flowing in via the heating chamber 15 can have or maintain a considerable temperature, so that the tip of the nozzle could possibly be endangered by overheating. In addition, there is a risk that, due to the high temperatures, the fuel will already carbonize in the spray openings 11 and thereby narrow the passage thereof or block it at all. For this reason, a heat protection 19 is arranged transversely to the flow direction on the dome 10 of the nozzle body 1, the end face of which is provided with a heat-insulating layer 20 toward the flow side. The heated by the heating coil 16 air flow in the bypass 15 is passed through the heat protection 19 to the outside and thus to the through openings 13, so that overheating of the actual tip 10 and thus the spray openings 11 or even the blind hole 9 is avoided.

In Fig. 3 ist als Variante des Wärmeschutzes dieses ersten Ausführungsbeispiels an der Kuppe 10"' ein Wärmeschutzschild 21 befestigt, der die gleiche obenbeschriebene Funktion hat wie der Wärmeschutz 19, jedoch verhältnismässig leicht an serienmässige Lochdüsen, beispielsweise durch Schweißen, anbringbar ist.In Fig. 3, as a variant of the thermal protection of this first embodiment, a thermal shield 21 is attached to the summit 10 "', which has the same function as the thermal protection 19 described above, but is relatively easy to attach to standard perforated nozzles, for example by welding.

Bei dem in Fig. 4 dargestellten zweiten Ausführungsbeispiel weist der rohrförmige Abschnitt 12' zum Brennraum 14 hin eine trichterförmige Erweiterung 23 auf. Hierdurch wird entsprechend der Eingang des Bypasses erweitert, so daß aus einer breiteren Zone der Brennkammer 14 Luft angesogen wird. Diese Luft überstreicht einen Heizleiter 24, der auf der Innenseite des Trichters 23 angeordnet ist. Danach gelangt dann die Luft in den zylindrischen Abschnitt der Luftleitvorrichtung 12', um dann über den Kraftstoffstrahl und die Durchgangsöffnungen 13 wieder in den Brennraum 14 zu strömen. Auf der Kuppe 10' des Düsenkörpers 1' dieses Ausführungsbeispiels, die zylindrisch ausgebildet ist, ist auf der der Strömung entgegengesetzten Stirnseite ein Wärmeschutz vorgesehen. In dieser Fig. 4 sind 2 Varianten dieses Wärmeschutzes dargestellt, und zwar jeweils eine links bzw. rechts der Mittelachse. Bei der rechten Variante handelt es sich um ein auf die Düsenkuppe 10' gesetztes, der Luftführung dienendes Röhrchen 25, welches noch ein Stück in den Trichter 23 hineinragt und gemeinsam mit diesem einen zum Teil konischen, als Bypass dienenden Ringkanal 26 begrenzt. Im übrigen wird durch den Kraftstoffstrahl die aufgeheizte Luft zu den Durchgangsöffnungen 13 gesogen, bevor sie zu Spritzöffnungen 11 gelangen kann.In the second exemplary embodiment shown in FIG. 4, the tubular section 12 ′ has a funnel-shaped extension 23 towards the combustion chamber 14. As a result, the input of the bypass is expanded accordingly, so that air is drawn in from a wider zone of the combustion chamber 14. This air sweeps over a heating conductor 24, which is arranged on the inside of the funnel 23. The air then enters the cylindrical section of the air guiding device 12 ′ in order to then flow back into the combustion chamber 14 via the fuel jet and the through openings 13. Thermal protection is provided on the dome 10 'of the nozzle body 1' of this exemplary embodiment, which is cylindrical, on the end face opposite the flow. 4 shows two variants of this thermal protection, one on the left and one on the right of the central axis. The variant on the right is a tube 25 which is placed on the nozzle tip 10 'and serves to guide the air, which protrudes a little further into the funnel 23 and, together with it, delimits a partially conical ring channel 26 which serves as a bypass. Otherwise, the heated air is drawn to the through openings 13 by the fuel jet before it can reach spray openings 11.

Bei der anderen, links der Mittelachse dargestellten Variante handelt es sich wiederum, wie beim ersten Ausführungsbeispiel, um eine Wärmedämmschicht 27 mit einer entsprechenden Wirkung.The other variant, shown on the left of the central axis, is again, as in the first exemplary embodiment, a thermal insulation layer 27 with a corresponding effect.

Natürlich sind auch Ausführungsmöglichkeiten der Erfindung denkbar, bei denen in einem trich- terförmigen und den Bypass bildenden Luftleitrohr zur Aufheizung der Luft eine kegelförmig ausgebildete Heizwendel angeordnet ist, und es ist genauso denkbar, daß in einem zylindrischen entsprechenden Bypassrohr an dessen Innenwänden Heizleiter vorgesehen sind. Es ist auch denkbar, daß im Rohr oder Trichter vorzugsweise koaxial ein Rohr mit Heizleitflächen angeordnet ist. Alle diese denkbaren Möglichkeiten werden zwar von der Erfindung erfaßt, sind aber insbesondere der Herstellungskosten wegen weniger bevorzugt zu betrachten, als die dargestellten Beispiele.Of course, possible embodiments of the invention are also conceivable in which a conical heating coil is arranged in a funnel - shaped air bypass tube which forms the bypass for heating the air, and it is equally conceivable that heating conductors are provided on the inside walls of a corresponding cylindrical bypass tube. It is also conceivable that a tube with heat conducting surfaces is preferably arranged coaxially in the tube or funnel. All of these conceivable possibilities are covered by the invention, but are to be considered less preferred than the examples shown, in particular because of the production costs.

In den Fig. 5 und 6 ist ein drittes Ausführungsbeispiel dargestellt, bei dem die aus dem Brennraum 14 angesogene Luft quer zur Düsenachse zu den Kraftstoffstrahlen strömt. Da die Kraftstoffstrahlen selbst bei diesem Ausführungsbeispiel, bei dem es ebenfalls um eine Lochdüse geht, auch quer zur Einspritzdüsenachse abgespritzt werden, erfolgt der Luftzu- und -austritt weitgehend in einer Ebene quer zur Einspritzdüsenachse.5 and 6, a third embodiment is shown, in which the air drawn in from the combustion chamber 14 flows transversely to the nozzle axis to the fuel jets. Since the fuel jets are also sprayed transversely to the injector axis even in this exemplary embodiment, which is also about a perforated nozzle, the air inlet and outlet largely take place in a plane transverse to the injector axis.

Wie in Fig. 5 im Längsschnitt der Kraftstoffeinspritzdüse dargestellt, ist über der Kuppe 10" des Düsenkörpers 1" eine Luftleitvorrichtung in Form einer kuppelartigen Haube 29 angeordnet, die im wesentlichen der Form der Kuppe 10" allerdings mit einem größeren Durchmesser folgt. Zwischen Kuppe 10" und dieser Haube 29 entsteht als Bypass ein Halbkugelringraum 30, von dem dann die entsprechenden und in der Haube angeordneten Durchgangsöffnungen sowie Eingangsöffnungen abzweigen. Als Eingangsöffnungen dienen in einer Ebene und zentralsymmetrisch angeordnete längliche Öffnungen 31. Die Ebene entspricht der Schnittebene VI-VI aus Fig. 5, wie sie in Fig. 6 dargestellt ist. In dieser Ebene sind entsprechend einem Teil der Spritzöffnungen 11" auch die diesen Spritzöffnungen zugeordneten Durchgangsöffnungen 13" angeordnet. Weitere Durchgangsöffnungen 13" sind wiederum achsgleich zu weiteren Spritzöffnungen 11" angeordnet, wobei diese gemeinsame Achse mit der genannten Ebene einen bestimmten Winkel einschließt. Die Verbrennungsluft-Aufheizung erfolgt über Heizleiter 32, die auf der äußeren Mantelfläche der Haube 29 derart angeordnet sind, daß sie von der zuströmenden Luft möglichst erfaßt werden. Da hier die Luft quer zur Düsenachse eintritt, ist einerseits der konische Haubenabschnitt 33 belegt und andererseits ein Teil des kugeligen Bereichs 29 in der Nähe der Eingangsöffnungen 31. Ein zusätzlicher Hitzeschutz an der Düsenkuppe 10" ist nicht mehr erforderlich, da die Verbrennungsluft, bevor sie tatsächlich mit der Kuppe in Berührung kommen kann, durch die Kraftstoffstrahlen wieder aus dem Bypass herausgerissen wird. Der elektrische Anschluß des Heizleiters 32 erfolgt über einen Anschlußdraht 34, der in einer Bohrung 35 der Düsenspannmutter verläuft und durch Glaseinschmelzung 36 gegenüber dieser isoliert ist.As shown in FIG. 5 in the longitudinal section of the fuel injection nozzle, an air guiding device in the form of a dome-like hood 29 is arranged above the dome 10 "of the nozzle body 1", but essentially follows the shape of the dome 10 "with a larger diameter. Between dome 10 "and this hood 29 is created as Bypass a hemispherical annular space 30, from which then branch off the corresponding through openings and inlet openings arranged in the hood. Elongated openings 31, which are arranged in a plane and centrally symmetrically, serve as input openings. The plane corresponds to the sectional plane VI-VI from FIG. 5, as shown in FIG. 6. The through openings 13 ″ assigned to these spray openings are also arranged in this plane in accordance with a part of the spray openings 11 ″. Further through openings 13 "are in turn arranged coaxially with further spray openings 11", this common axis enclosing a certain angle with the plane mentioned. The combustion air is heated via heating conductors 32, which are arranged on the outer circumferential surface of the hood 29 in such a way that they are captured by the inflowing air as far as possible. Since the air enters transversely to the nozzle axis here, on the one hand the conical hood section 33 is occupied and on the other hand a part of the spherical area 29 near the inlet openings 31. Additional heat protection at the nozzle tip 10 "is no longer necessary, since the combustion air before it can actually come into contact with the tip, by means of which fuel jets are torn out of the bypass again. The electrical connection of the heating conductor 32 takes place via a connecting wire 34, which runs in a bore 35 of the nozzle clamping nut and is insulated from it by glass melting 36.

Erfindungsgemäß ist auch denkbar, daß die Aufheizung zwei Heizstufen ermöglicht, die entweder alternativ oder parallel einschaltbar sind. So könnte eine stärkere Heizleistung bei Kaltstart eingesetzt werden und eine schwächere, beispielsweise kontinuierliche, als Dauerheizung zur Verbesserung des Verbrennungsablaufs.According to the invention, it is also conceivable that the heating enables two heating stages, which can be switched on either alternatively or in parallel. For example, a stronger heating output could be used during a cold start and a weaker, for example continuous one, as permanent heating to improve the combustion process.

Claims (12)

1. Apparatus for injecting fuel into a combustion chamber of an internal combustion engine, in particular self-igniting, with an injection nozzle which has at least one spray opening (11) which is arranged at an angle to the nozzle axis and through which defined fuel jets are discharged which are directed towards the side, characterized in that provided between the spray opening the (or spray opening) (11) and combustion chamber (14) is a dividing wall (12, 23, 29) which surrounds at a radial distance the area (10) of the injection nozzle provided with the spray openings (11) and is provided with through openings (13) for the fuel jets, that, moreover, the dividing wall (12, 23, 29) acts as a conducting device for a bypass of the combustion air from the combustion chamber (14) via the through openings (13) back to the combustion chamber and is designed in such a way that the fuel jets at the through openings (13) produce an injector effect accelerating the combustion air in this bypass, and that, on or inside the dividing wall (12, 23, 29), a heating device is provided at which the combustion air drawn in is heated before entering into the through openings (13).
2. Apparatus according to Claim 1, characterized in that a heating element which can be heated up electrically is provided as the heating device.
3. Apparatus according to Claim 1 or 2, characterized in that the areas (10) exposed to the heated-up combustion air and having the spray openings (11) are provided with heatscreening means (20, 25).
4. Apparatus according to Claim 3 characterized in that a thermal insulation layer (20, 27) serves as a heat-screening means.
5. Apparatus according to Claim 3, characterized in that a screening plate (25) which dissipates the hot air serves as a heat-screening means.
6. Apparatus according to one of the preceding claims, with a nozzle body which has spray openings arranged transversely to the longitudinal axis of the injection nozzle and is clamped tightly on a nozzle holder by a nozzle clamping nut, characterized in that the dividing wall.(12, 23, 29) is arranged on the nozzle clamping nut (2).
7. Apparatus according to Claim 6, characterized in that the dividing wall (12, 23) is designed as a tube section (12, 23) which runs on the same axis as the injection nozzle and is open on the side remote from the nozzle, and the heating device (16, 24) is arranged in the space enclosed by the tube section (12, 23).
8. Apparatus according to Claim 7, characterized in that an electrically heated glow coil (16) running coaxially to the tube section (12) serves as the heating device.
9. Apparatus according to Claim 7, characterized in that at least one heating conductor (24) arranged on the inner wall of the tube section, serves as the heating device.
10. Apparatus according to one of Claims 7-9, characterized in that the tube section (12) is widened in a funnel shape (23) towards the combustion chamber (14) after a cylindrical section.
11. Apparatus according to one of Claims 1-6, characterized in that a dome-shaped hood (29) in which the through openings (13) and also inflow openings (31) run transversely to the nozzle axis serves as the dividing wall.
12. Apparatus according to Claim 11, characterized in that upstream of the inlet openings (31 heating conductors (32, 33) are arranged on the dividing wall (29).
EP84900267A 1983-04-27 1983-12-20 Device for injecting fuel into a secondary flow of combustion air in a combustion chamber Expired EP0148837B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84900267T ATE33169T1 (en) 1983-04-27 1983-12-20 DEVICE FOR INJECTING FUEL INTO A SECONDARY FLOW OF COMBUSTION AIR OF A COMBUSTION CHAMBER.

Applications Claiming Priority (2)

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DE19833315241 DE3315241A1 (en) 1983-04-27 1983-04-27 DEVICE FOR INJECTING FUEL INTO A SECONDARY FLOW OF COMBUSTION AIR FROM A COMBUSTION CHAMBER
DE3315241 1983-04-27

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EP0148837A1 EP0148837A1 (en) 1985-07-24
EP0148837B1 true EP0148837B1 (en) 1988-03-23

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EP (1) EP0148837B1 (en)
JP (1) JPS60501165A (en)
AT (1) ATE33169T1 (en)
DE (2) DE3315241A1 (en)
IT (1) IT1176060B (en)
WO (1) WO1984004359A1 (en)

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Publication number Publication date
WO1984004359A1 (en) 1984-11-08
ATE33169T1 (en) 1988-04-15
DE3315241A1 (en) 1984-10-31
IT8420550A1 (en) 1985-10-16
JPS60501165A (en) 1985-07-25
EP0148837A1 (en) 1985-07-24
IT1176060B (en) 1987-08-12
DE3376080D1 (en) 1988-04-28
US4604975A (en) 1986-08-12
IT8420550A0 (en) 1984-04-16

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