EP0101822B1 - Fuel injector for an internal-combustion engine - Google Patents

Fuel injector for an internal-combustion engine Download PDF

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Publication number
EP0101822B1
EP0101822B1 EP19830106278 EP83106278A EP0101822B1 EP 0101822 B1 EP0101822 B1 EP 0101822B1 EP 19830106278 EP19830106278 EP 19830106278 EP 83106278 A EP83106278 A EP 83106278A EP 0101822 B1 EP0101822 B1 EP 0101822B1
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EP
European Patent Office
Prior art keywords
fuel
discharge hole
chamber
nozzle
injection
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19830106278
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German (de)
French (fr)
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EP0101822A1 (en
Inventor
Katsuoki Dipl.-Ing. Itoh
Iwan Komaroff
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of EP0101822A1 publication Critical patent/EP0101822A1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/06Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves being furnished at seated ends with pintle or plug shaped extensions
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for

Definitions

  • the invention relates to a fuel injection nozzle according to the preamble of the main claim.
  • Injectors of this type e.g. are known from EP-A-0 020 888, are used in diesel engines with a divided combustion chamber.
  • the special injection characteristics of these injection nozzles with a pronounced pre-jet and main jet enable low-noise combustion of the injected fuel.
  • the arrangement according to the invention with the characterizing features of the main claim has the advantage that no combustion gases can get into or into the fuel outlet opening when the fuel is injected.
  • the combustion gases can penetrate into the outlet chamber, but they deposit the soot particles carried away on the walls of the outlet chamber away from the fuel outlet opening.
  • the spray jet sucks fuel gases through the side channel or channels, which prevents the spray jet from depositing on one side of the outlet chamber with small injection quantities and taking on an undesirable shape.
  • the conically narrowing section of the outlet opening ensures that the spray jets only wet the edge at the outlet opening of the outlet chamber and the hydrocarbon pollutant emission remains within acceptable limits.
  • the arrangement according to the invention is particularly advantageous in the case of injection nozzles in which the throttle pin of the valve needle is provided on the end face with a taper pin which is smaller in diameter and which, when the valve is fully open, plunges at least a bit into the nozzle bore.
  • a flow separation on the wall of the nozzle bore and of the taper pin on the valve needle occurs without the arrangement of an outlet chamber with small injection quantities, which promotes the penetration of soot and prevents its removal.
  • the side channels of the outlet chamber are particularly effective if they are closer to the beginning of the outlet chamber than to the outlet opening.
  • the outlet chamber is expediently ventilated via at least three evenly distributed channels which advantageously open tangentially into the outlet chamber.
  • the front part is an individual part placed on the nozzle housing, the other parts of the injection nozzle can largely have the conventional structure.
  • FIG. 1 shows a side view of the exemplary embodiment, partly in section
  • FIG. 2 enlarges area A of FIG. 1
  • FIG. 3 shows a section along line 111-111 in FIG. 2.
  • the injection nozzle has a nozzle body 10, in which a valve seat 12 is formed and a valve needle 14 is slidably mounted.
  • the valve needle 14 has a conical section 16, which forms a valve surface which cooperates with the valve seat 12. Closes at section 16 a throttle pin 18 engages, which engages with little play through a nozzle bore 20, which leads from the valve seat 12 to the end face 22 of the nozzle body 10 on the combustion chamber side.
  • a taper pin 19 with a smaller diameter is formed on the throttle pin 18 and is used for shaping the spray jet in the usual use of the injection nozzle.
  • the nozzle body 10 is clamped together with an washer 24 to a nozzle holder 28 by means of a union nut 26.
  • This is provided with a connecting piece 30 for a fuel supply line, which is connected via channels 32, 34, 36, 38 and 40 to a pressure chamber 42 in the nozzle body 10.
  • the pressure chamber 42 is connected to the nozzle bore 20 via the valve seat 12 and in the region of the pressure chamber 42 the valve needle 14 is provided with a pressure shoulder 44.
  • the valve needle 14 has a pin 46 upstream, which projects into a stepped center bore of the intermediate disk 24 and carries a pressure piece 48, via which a closing spring 52 arranged in a chamber 50 of the nozzle holder 28 acts on the valve needle 14 in the closing direction.
  • the force of the closing spring 52 is directed against the pressure of the fuel which it exerts in the annular space 42 on the pressure shoulder 44 of the valve needle 14.
  • the structure described so far corresponds to that of a conventional throttle pin nozzle.
  • a quantity-limited pre-jet first squirts out through the fuel outlet opening, which is formed at the combustion chamber-side opening of the throttle gap between the throttle pin 18 and the nozzle bore 20.
  • the main jet of fuel is sprayed out through the then substantially larger annular gap between the nozzle bore 20 and the taper pin 19.
  • the combustion gases can enter the fuel outlet opening after closing the valve 12, 14 and gradually clog it.
  • the fuel jet separates from the wall of the nozzle bore 20 and the taper pin 19 in the main injection phase. This favors the penetration of soot into the nozzle bore 20 and thereby the premature clogging of the fuel outlet opening, which in turn changes the injection process and worsens engine operation.
  • an attachment part 58 is attached to the nozzle body 10 in the injection nozzle according to the invention, which has a central outlet chamber 60 through which the sprayed fuel jet passes.
  • the outlet chamber 60 has a cylindrical section 62 which is adjoined by a conically narrowing section 64. This ends in a narrow cylindrical ring edge 66 which encloses an outlet opening 68.
  • Four channels 70 open tangentially in section 62, the function of which is described below.
  • the spray jet entering the outlet chamber 60 sucks air or combustion gases out of the combustion chamber through the channels 70 as a result of the injector action, and these are expelled again with the spray jet through the outlet opening 68.
  • the spray jet thus receives a larger volume and, if the cross-sections of the outlet chamber 60 and the channels 70 are appropriately coordinated, fills the cross-section of the cross-section of the at every operating point of the machine and at least approximately over the entire opening stroke of the valve needle 14, with the other parameters determining the injection quantity and the course of the injection Exit opening 68 fully out.
  • the spray jet would deposit on one side of the outlet chamber 60 with small injection quantities, which could impair its protective function.
  • the spray jet emerging from the outlet chamber 60 practically only wets the very narrow ring edge 66, as a result of which an increased hydrocarbon emission is avoided.
  • the proposal according to the invention can be usefully supplemented by keeping the length of the nozzle bore 20 as short as possible.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Kraftstoff-Einspritzdüse nach der Gattung des Hauptanspruchs. Einspritzdüsen dieser Gattung, die z.B. aus der EP-A-0 020 888 bekannt sind, werden bei Dieselmotoren mit unterteiltem Verbrennungsraum verwendet. Die besondere Einspritzcharakteristik dieser Einspritzdüsen mit ausgeprägten Vor- und Hauptstrahl ermöglicht eine geräuscharme Verbrennung des eingespritzten Kraftstoffs. Nachteilig ist jedoch, dass die Verbrennungsgase aus dem Brennraum unmittelbar an die Kraftstoffaustrittsöffnung der Düsenbohrung gelangen, so dass sich diese verhältnismässig rasch durch abgelagerte Russteilchen aus den Brenngasen zusetzt.The invention relates to a fuel injection nozzle according to the preamble of the main claim. Injectors of this type, e.g. are known from EP-A-0 020 888, are used in diesel engines with a divided combustion chamber. The special injection characteristics of these injection nozzles with a pronounced pre-jet and main jet enable low-noise combustion of the injected fuel. However, it is disadvantageous that the combustion gases from the combustion chamber directly reach the fuel outlet opening of the nozzle bore, so that the latter is clogged relatively quickly by deposited soot particles from the combustion gases.

Zur Sicherstellung einer vollständigen Verbrennung des Kraftstoffs auch bei ungünstigen Betriebsbedingungen ist es bei Kraftstoff-Einspritzdüsen aus der FR-A-2 147 631 bekannt, mehr oder weniger stark vorgewärmte Luft durch einen zusätzlichen Druckerzeuger in die Spritzstrahlen einzublasen. Zu diesem Zweck ist die Einspritzdüse in einem in die Brennkammer führenden Kanal eingesetzt, in welchem die Luft stromauf der Kraftstoffaustrittsöffnung der Einspritzdüse eingeblasen wird und welcher unmittelbar stromab der Kraftstoffaustrittsöffnung eine die eingeblasene Luft in die Spritzstrahlen lenkende Einschnürung hat, hinter der sich der Kanalquerschnitt wieder erweitert. Diese Ausführung kann nicht verhindern, dass Russteilchen aus den Brenngasen an die Kraftstoffaustrittsöffnung gelangen und dort die geschilderten nachteiligen Wirkungen hervorrufen.In order to ensure complete combustion of the fuel even under unfavorable operating conditions, it is known for fuel injection nozzles from FR-A-2 147 631 to blow more or less preheated air into the spray jets by means of an additional pressure generator. For this purpose, the injection nozzle is inserted into a channel leading into the combustion chamber, in which the air is blown upstream of the fuel outlet opening of the injection nozzle and which immediately downstream of the fuel outlet opening has a constriction which directs the blown air into the spray jets, behind which the channel cross section widens again . This embodiment cannot prevent soot particles from the fuel gases from reaching the fuel outlet opening and causing the adverse effects described there.

Bei Kraftstoff-Einspritzdüsen, die zwischen ihrem Ventilsitz und der Kraftstoffaustrittsöffnung eine Drallkammer haben (US-A-1 843 821) und dadurch ein verhältnismässig grosses schädliches Kraftstoffvolumen aufweisen, ist es bekannt, das Bilden von Kraftstofftröpfchen an der Kraftstoffaustrittsöffnung durch Einsaugen von Luft in die schirmartigen Spritzstrahlen zu vermeiden bzw. schon gebildete Kraftstofftröpfchen zu zerstäuben und abzuführen. Zu diesem Zweck ist der Kraftstoffaustrittsöffnung ein Vorsatzteil nachgeschaltet, welches sich konisch zur Brennkammer hin erweitert und in seinem Mantel mit einem Kranz von Luftansaugöffnungen versehen ist. Durch das Abführen bzw. Verhindern von Kraftstofftröpfchen wird zwar letztlich auch einem Verkoken der Kraftstoffaustrittsöffnung entgegengewirkt. Der zur Brennkammer hin sich konisch erweiternde Vorsatzteil könnte bei Einspritzdüsen der gattungsmässigen Art jedoch ebenfalls nicht verhindern, dass Brenngase in den Spritzpausen und in Betriebsbereichen mit geringen Einspritzraten an die Kraftstoffaustrittsöffnung gelangen und dort Russteilchen ablagern.In the case of fuel injection nozzles which have a swirl chamber between their valve seat and the fuel outlet opening (US Pat. No. 1,843,821) and therefore have a comparatively large harmful fuel volume, it is known to form fuel droplets at the fuel outlet opening by sucking air into them to avoid umbrella-like spray jets or to atomize and remove already formed fuel droplets. For this purpose, the fuel outlet opening is followed by a front part, which widens conically towards the combustion chamber and is provided in its jacket with a ring of air intake openings. The removal or prevention of fuel droplets ultimately counteracts coking of the fuel outlet opening. In the case of injection nozzles of the generic type, however, the front part, which widens conically towards the combustion chamber, could also not prevent fuel gases from reaching the fuel outlet opening during injection breaks and in operating areas with low injection rates and depositing soot particles there.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemässe Anordnung mit den kennzeichnenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, dass beim Einspritzen des Kraftstoffs keine Verbrennungsgase an oder in die Kraftstoffaustrittsöffnung gelangen können. In der Schlussphase der Einspritzung können die Verbrennungsgase zwar in die Austrittskammer eindringen, wobei sie jedoch die mitgeführten Russteilchen entfernt von der Kraftstoffaustrittsöffnung an den Wänden der Austrittskammer ablagern. Der Spritzstrahl saugt infolge Injektorwirkung Brenngase durch den oder die seitlichen Kanäle an, wodurch verhindert wird, dass sich der Spritzstrahl bei kleinen Einspritzmengen an einer Seite der Austrittskammer anlegt und eine unerwünschte Form annimmt. Durch den sich konisch verengenden Abschnitt der Austrittsöffnung ist erreicht, dass die Spritzstrahlen nur die Kante an der Austrittsöffnung der Austrittskammer benetzen und die Kohlenwasserstoff-Schademission in tragbaren Grenzen bleibt.The arrangement according to the invention with the characterizing features of the main claim has the advantage that no combustion gases can get into or into the fuel outlet opening when the fuel is injected. In the final phase of the injection, the combustion gases can penetrate into the outlet chamber, but they deposit the soot particles carried away on the walls of the outlet chamber away from the fuel outlet opening. As a result of the injector action, the spray jet sucks fuel gases through the side channel or channels, which prevents the spray jet from depositing on one side of the outlet chamber with small injection quantities and taking on an undesirable shape. The conically narrowing section of the outlet opening ensures that the spray jets only wet the edge at the outlet opening of the outlet chamber and the hydrocarbon pollutant emission remains within acceptable limits.

Die erfindungsgemässe Anordnung ist besonders vorteilhaft bei Einspritzdüsen, bei denen der Drosselzapfen der Ventilnadel stirnseitig mit einem im Durchmesser kleineren Kegelzapfen versehen ist, der bei voll geöffnetem Ventil mindestens ein Stück weit in die Düsenbohrung eintaucht. Bei derartigen Einspritzdüsen tritt ohne die Anordnung einer Austrittskammer bei kleinen Einspritzmengen eine Strömungsablösung an der Wand der Düsenbohrung und des Kegelzapfens an der Ventilnadel auf, welche das Eindringen von Russ begünstigt und dessen Abtragung verhindert. Durch die Anordnung der Austrittskammer werden diese Nachteile vermieden.The arrangement according to the invention is particularly advantageous in the case of injection nozzles in which the throttle pin of the valve needle is provided on the end face with a taper pin which is smaller in diameter and which, when the valve is fully open, plunges at least a bit into the nozzle bore. With such injection nozzles, a flow separation on the wall of the nozzle bore and of the taper pin on the valve needle occurs without the arrangement of an outlet chamber with small injection quantities, which promotes the penetration of soot and prevents its removal. These disadvantages are avoided by the arrangement of the outlet chamber.

Durch die in den Unteransprüchen aufgeführten Massnahmen sind vorteilhafte Weiterbildungen der im Hauptanspruch angegebenen Anordnung möglich.The measures listed in the subclaims permit advantageous developments of the arrangement specified in the main claim.

Die seitlichen Kanäle der Austrittskammer sind besonders wirksam, wenn sie näher am Beginn der Austrittskammer als an deren Austrittsöffnung liegen. Zweckmässig ist die Austrittskammer über mindestens drei gleichmässig verteilte Kanäle belüftet, die vorteilhaft tangential in die Austrittskammer einmünden.The side channels of the outlet chamber are particularly effective if they are closer to the beginning of the outlet chamber than to the outlet opening. The outlet chamber is expediently ventilated via at least three evenly distributed channels which advantageously open tangentially into the outlet chamber.

Wenn der Vorsatzteil ein auf das Düsengehäuse aufgesetztes Einzelteil ist, können die anderen Teile der Einspritzdüse weitgehend den herkömmlichen Aufbau haben.If the front part is an individual part placed on the nozzle housing, the other parts of the injection nozzle can largely have the conventional structure.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eine Seitenansicht des Ausführungsbeispiels, teilweise im Schnitt, Figur 2 vergrössert den Bereich A der Figur 1 und Figur 3 einen Schnitt nach der Linie 111-111 in Figur 2.An embodiment of the invention is shown in the drawing and explained in more detail in the following description. FIG. 1 shows a side view of the exemplary embodiment, partly in section, FIG. 2 enlarges area A of FIG. 1 and FIG. 3 shows a section along line 111-111 in FIG. 2.

Beschreibung des AusführungsbeispielsDescription of the embodiment

Die Einspritzdüse hat einen Düsenkörper 10, in welchem ein Ventilsitz 12 gebildet und eine Ventilnadel 14 verschiebbar gelagert ist. Die Ventilnadel 14 hat einen kegeligen Abschnitt 16, welcher eine mit dem Ventilsitz 12 zusammenarbeitende Ventilfläche bildet. An den Abschnitt 16 schliesst sich ein Drosselzapfen 18 an, der mit geringem Spiel durch eine Düsenbohrung 20 greift, welche vom Ventilsitz 12 ausgehend zur brennraumseitigen Stirnfläche 22 des Düsenkörpers 10 führt. An den Drosselzapfen 18 ist ein im Durchmesser kleinerer Kegelzapfen 19 angeformt, der bei üblicher Verwendung der Einspritzdüse zur Spritzstrahlformung dient.The injection nozzle has a nozzle body 10, in which a valve seat 12 is formed and a valve needle 14 is slidably mounted. The valve needle 14 has a conical section 16, which forms a valve surface which cooperates with the valve seat 12. Closes at section 16 a throttle pin 18 engages, which engages with little play through a nozzle bore 20, which leads from the valve seat 12 to the end face 22 of the nozzle body 10 on the combustion chamber side. A taper pin 19 with a smaller diameter is formed on the throttle pin 18 and is used for shaping the spray jet in the usual use of the injection nozzle.

Der Düsenkörper 10 ist zusammen mit einer Zwischenscheibe 24 durch eine Überwurfmutter 26 an einem Düsenhalter 28 festgespannt. Dieser ist mit einem Anschlussstutzen 30 für eine Kraftstoff-Zuführungsleitung versehen, der über Kanäle 32,34,36,38 und 40 mit einem Druckraum 42 im Düsenkörper 10 verbunden ist. Der Druckraum 42 ist über den Ventilsitz 12 mit der Düsenbohrung 20 verbunden und im Bereich des Druckraumes 42 ist die Ventilnadel 14 mit einer Druckschulter 44 versehen.The nozzle body 10 is clamped together with an washer 24 to a nozzle holder 28 by means of a union nut 26. This is provided with a connecting piece 30 for a fuel supply line, which is connected via channels 32, 34, 36, 38 and 40 to a pressure chamber 42 in the nozzle body 10. The pressure chamber 42 is connected to the nozzle bore 20 via the valve seat 12 and in the region of the pressure chamber 42 the valve needle 14 is provided with a pressure shoulder 44.

Die Ventilnadel 14 hat stromauf einen Zapfen 46, der in eine gestufte Mittenbohrung der Zwischenscheibe 24 hineinragt und ein Druckstück 48 trägt, über welches eine in einer Kammer 50 des Düsenhalters 28 angeordnete Schliessfeder 52 auf die Ventilnadel 14 im Schliesssinn einwirkt. Die Kraft der Schliessfeder 52 ist dem Druck des Kraftstoffs entgegengerichtet, welcher dieser im Ringraum 42 auf die Druckschulter 44 der Ventilnadel 14 ausübt.The valve needle 14 has a pin 46 upstream, which projects into a stepped center bore of the intermediate disk 24 and carries a pressure piece 48, via which a closing spring 52 arranged in a chamber 50 of the nozzle holder 28 acts on the valve needle 14 in the closing direction. The force of the closing spring 52 is directed against the pressure of the fuel which it exerts in the annular space 42 on the pressure shoulder 44 of the valve needle 14.

Der bisher beschriebene Aufbau entspricht dem einer herkömmlichen Drosselzapfendüse. Beim Öffnungshub der Ventilnadel 14 spritzt zunächst ein mengenmässig begrenzter Vorstrahl durch die Kraftstoffaustrittsöffnung aus, die an der brennraumseitigen Ausmündung des zwischen dem Drosselzapfen 18 und der Düsenbohrung 20 sich befindenden Drosselspaltes gebildet ist. Wenn der Drosselzapfen 18 aus der Düsenbohrung 20 ausgetreten ist, wird durch den dann wesentlich grösseren Ringspalt zwischen Düsenbohrung 20 und Kegelzapfen 19 der Hauptstrahl des Kraftstoffs ausgespritzt. Ohne zusätzliche Schutzmassnahmen können die Verbrennungsgase nach dem Schliessen des Ventils 12,14 an die Kraftstoffaustrittsöffnung treten und diese allmählich zusetzen. Im Teillastbetrieb kann es ausserdem vorkommen, dass in der Haupteinspritzphase sich der Kraftstoffstrahl von der Wand der Düsenbohrung 20 und des Kegelzapfens 19 ablöst. Das begünstigt das Eindringen von Russ in die Düsenbohrung 20 und dadurch das vorzeitige Zusetzen der Kraftstoffaustrittsöffnung, was seinerseits den Einspritzverlauf verändert und den Motorbetrieb verschlechtert.The structure described so far corresponds to that of a conventional throttle pin nozzle. During the opening stroke of the valve needle 14, a quantity-limited pre-jet first squirts out through the fuel outlet opening, which is formed at the combustion chamber-side opening of the throttle gap between the throttle pin 18 and the nozzle bore 20. When the throttle pin 18 has emerged from the nozzle bore 20, the main jet of fuel is sprayed out through the then substantially larger annular gap between the nozzle bore 20 and the taper pin 19. Without additional protective measures, the combustion gases can enter the fuel outlet opening after closing the valve 12, 14 and gradually clog it. In partial load operation, it can also happen that the fuel jet separates from the wall of the nozzle bore 20 and the taper pin 19 in the main injection phase. This favors the penetration of soot into the nozzle bore 20 and thereby the premature clogging of the fuel outlet opening, which in turn changes the injection process and worsens engine operation.

Um diese Nachteile zu vermeiden, ist bei der erfindungsgemässen Einspritzdüse am Düsenkörper 10 ein Vorsatzteil 58 befestigt, das eine zentrale Austrittskammer 60 hat, durch die der ausgespritzte Kraftstoffstrahl hindurchtritt. Die Austrittskammer 60 hat einen zylindrischen Abschnitt 62, an den sich ein konisch verengender Abschnitt 64 anschliesst. Dieser endet in einer schmalen zylindrischen Ringkante 66, welche eine Austrittsöffnung 68 umschliesst. In den Abschnitt 62 münden tangential vier Kanäle 70 ein, deren Funktion im nachfolgenden beschrieben wird.In order to avoid these disadvantages, an attachment part 58 is attached to the nozzle body 10 in the injection nozzle according to the invention, which has a central outlet chamber 60 through which the sprayed fuel jet passes. The outlet chamber 60 has a cylindrical section 62 which is adjoined by a conically narrowing section 64. This ends in a narrow cylindrical ring edge 66 which encloses an outlet opening 68. Four channels 70 open tangentially in section 62, the function of which is described below.

Beim Einspritzen des Kraftstoffs saugt der in die Austrittskammer 60 eintretende Spritzstrahl infolge Injektorwirkung durch die Kanäle 70 Luft- bzw. Verbrennungsgase aus der Brennkammer ein, die mit dem Spritzstrahl durch die Austrittsöffnung 68 wieder ausgestossen werden. Der Spritzstrahl erhält so ein grösseres Volumen und füllt bei entsprechender Abstimmung der Querschnitte der Austrittskammer 60 und der Kanäle 70 mit den übrigen, die Einspritzmenge und den Einspritzverlauf bestimmenden Parametern bei jedem Betriebspunkt der Maschine und mindestens annähernd über den gesamten Öffnungshub der Ventilnadel 14 den Querschnitt der Austrittsöffnung 68 voll aus. Bei Fehlen der Kanäle 70 würde sich der Spritzstrahl bei kleinen Einspritzmengen an einer Seite der Austrittskammer 60 anlegen, wodurch deren Schutzfunktion beeinträchtigt sein könnte. Der aus der Austrittskammer 60 austretende Spritzstrahl benetzt praktisch nur die sehr schmale Ringkante 66, wodurch eine erhöhte Kohlenwasserstoff-Schademission vermieden ist. Der erfindungsgemässe Vorschlag kann sinnvoll dadurch ergänzt werden, dass die Länge der Düsenbohrung 20 so kurz wie möglich gehalten wird.When the fuel is injected, the spray jet entering the outlet chamber 60 sucks air or combustion gases out of the combustion chamber through the channels 70 as a result of the injector action, and these are expelled again with the spray jet through the outlet opening 68. The spray jet thus receives a larger volume and, if the cross-sections of the outlet chamber 60 and the channels 70 are appropriately coordinated, fills the cross-section of the cross-section of the at every operating point of the machine and at least approximately over the entire opening stroke of the valve needle 14, with the other parameters determining the injection quantity and the course of the injection Exit opening 68 fully out. In the absence of the channels 70, the spray jet would deposit on one side of the outlet chamber 60 with small injection quantities, which could impair its protective function. The spray jet emerging from the outlet chamber 60 practically only wets the very narrow ring edge 66, as a result of which an increased hydrocarbon emission is avoided. The proposal according to the invention can be usefully supplemented by keeping the length of the nozzle bore 20 as short as possible.

Claims (3)

1. Fuel injection nozzle for internal combustion engines, with a nozzle body, in which a valve seat is formed and a valve needle is displaceably mounted, which valve needle opens against the fuel flow, is acted upon by a closing spring and, in the other direction, by the fuel pressure, and which is provided at the front with a throttle pin which enters, with throttling clearance, in a nozzle bore adjoining the valve seat on the downstream side and, along with the wall of the nozzle bore, bounds a fuel discharge hole, characterized in that an attachment (58) with a discharge chamber (60) is arranged downstream of the fuel discharge hole, in that the discharge chamber (60) has a cylindrical section (62) which is concentric to the fuel discharge hole, adjoins the wall having the discharge hole with a diameter which is greater than that of the fuel discharge hole and which has a section (64) which tapers conically in flow direction, adjoins the cylindrical section (62) and extends up to the discharge hole (68) on the combustion chamber side, in that at least one passage (70) opening toward the combustion chamber opens out into the cylindrical section (62) to supply air to the discharge chamber (60), and in that the cross- sections of the discharge chamber (60) and of the passage (70) are matched to each other and with respect to the parameters determining the injection quantity and the injection sequence in such a way that the injected jet completely fills the discharge hole (68) of the discharge chamber (60) at least approximately over the entire opening stroke of the valve needle (14) and at every operating point of the internal combustion engine.
2. Injection nozzle according to Claim 1, characterized in that at least three passages (70) offset uniformly with respect to one another are provided, which open out closer to the beginning of the discharge chamber (60) than to its discharge hole (68) and preferably lead tangentally into the discharge chamber (60).
3. Injection nozzle according to Claim 1 or 2, characterized in that the attachment (58) is a component part fitted on the nozzle housing.
EP19830106278 1982-08-05 1983-06-28 Fuel injector for an internal-combustion engine Expired EP0101822B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3229190 1982-08-05
DE19823229190 DE3229190A1 (en) 1982-08-05 1982-08-05 FUEL INJECTION NOZZLE FOR INTERNAL COMBUSTION ENGINES

Publications (2)

Publication Number Publication Date
EP0101822A1 EP0101822A1 (en) 1984-03-07
EP0101822B1 true EP0101822B1 (en) 1987-10-28

Family

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Application Number Title Priority Date Filing Date
EP19830106278 Expired EP0101822B1 (en) 1982-08-05 1983-06-28 Fuel injector for an internal-combustion engine

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EP (1) EP0101822B1 (en)
JP (1) JPS5943963A (en)
DE (2) DE3229190A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01300057A (en) * 1988-05-30 1989-12-04 Isuzu Motors Ltd Fuel injection nozzle
DE60125786T2 (en) * 2001-11-27 2007-10-11 Toyota Jidosha Kabushiki Kaisha, Toyota Injection valve for an exhaust gas purification device
JP5811979B2 (en) * 2012-09-24 2015-11-11 株式会社デンソー Fuel injection valve

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1330181A (en) * 1970-09-25 1973-09-12 Petrol Injection Ltd Fuel injection nozzles
EP0007724A1 (en) * 1978-07-06 1980-02-06 Nissan Motor Co., Ltd. Fuel injector valve
EP0020888A1 (en) * 1979-06-22 1981-01-07 Robert Bosch Gmbh Fuel injection nozzle for internal-combustion engines

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1843821A (en) * 1929-09-30 1932-02-02 Joslyn Diesel Engine Company L Fuel atomizing nozzle
CH356636A (en) * 1956-06-15 1961-08-31 Exxon Research Engineering Co Injection valve for a diesel engine and method for operating the same
DE2137030A1 (en) * 1971-07-23 1973-02-01 Werner Dipl Phys Kraus FUEL INJECTION DEVICE
DE2610927C2 (en) * 1976-03-16 1983-01-27 Institut für Motorenbau Prof. Huber e.V., 8000 München Injection nozzle for injecting fuel into the combustion chamber of an internal combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1330181A (en) * 1970-09-25 1973-09-12 Petrol Injection Ltd Fuel injection nozzles
EP0007724A1 (en) * 1978-07-06 1980-02-06 Nissan Motor Co., Ltd. Fuel injector valve
EP0020888A1 (en) * 1979-06-22 1981-01-07 Robert Bosch Gmbh Fuel injection nozzle for internal-combustion engines

Also Published As

Publication number Publication date
EP0101822A1 (en) 1984-03-07
DE3229190A1 (en) 1984-02-09
DE3374210D1 (en) 1987-12-03
JPS5943963A (en) 1984-03-12

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