EP0246220B1 - Injection nozzle for internal-combustion engines, particularly for diesel engines - Google Patents

Injection nozzle for internal-combustion engines, particularly for diesel engines Download PDF

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Publication number
EP0246220B1
EP0246220B1 EP19870890095 EP87890095A EP0246220B1 EP 0246220 B1 EP0246220 B1 EP 0246220B1 EP 19870890095 EP19870890095 EP 19870890095 EP 87890095 A EP87890095 A EP 87890095A EP 0246220 B1 EP0246220 B1 EP 0246220B1
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EP
European Patent Office
Prior art keywords
valve
valve stem
projections
injection nozzle
stem
Prior art date
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
EP19870890095
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German (de)
French (fr)
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EP0246220A1 (en
Inventor
Hans Dipl.-Ing.Dr. List
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AVL List GmbH
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AVL Gesellschaft fuer Verbrennungskraftmaschinen und Messtechnik mbH
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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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/08—Fuel-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 opening in direction of fuel flow
    • 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
    • F02M61/165—Filtering elements specially adapted in fuel inlets to injector
    • 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
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift

Definitions

  • the invention relates to an injection nozzle for internal combustion engines, in particular diesel engines, with a poppet valve which consists of a valve disk and valve stem and which opens due to the fuel pressure in the flow direction with a very small stroke, the stroke of the poppet valve being limited by a stop which is in the vicinity of the valve disk is provided and is formed by projections which are provided on the inside of the valve housing and on the outside of the valve stem, the mutually facing contact surfaces of these projections projecting from one another by the desired maximum stroke when the valve is closed.
  • Such an injection nozzle is used for uniform distribution of the fuel along the circumference of an at least approximately rotationally shaped combustion chamber, the injection nozzle being arranged approximately in the axis of the combustion chamber.
  • the fuel emerges from the injection nozzle in the form of a cone jacket with a very small wall thickness; it offers the relatively little moving combustion air in the combustion chamber a very large target. As it moves against the circumference of the combustion chamber at high speed during injection, there is a strong friction between the fuel and the air, which splits the fuel into tiny droplets. The air is accelerated by the impulse of the fuel moving at high speed in the direction of the circumference of the combustion chamber in accordance with the impact laws, which creates flows in the combustion chamber which are directed from the injection nozzle to the circumference and then lead from the circumference against the injection nozzle.
  • the angle of the fuel jacket in the combustion chamber and this itself must be coordinated so that an equal mixture of fuel and air occurs.
  • the opening angle of the injected fuel cone jacket is at least 90 ° , preferably 120 to 160 ° .
  • the stroke of the valve plate is accordingly very small, approximately in the order of magnitude of one or several hundredths of a millimeter.
  • An injection nozzle of the type mentioned is known from DE-C 933 003.
  • a conical valve body is provided, but with an acute cone angle, which cooperates with a correspondingly conical valve seat in one valve seat plate.
  • the valve body opens due to the fuel pressure in the direction of flow and overcomes the force of a coil spring.
  • the valve seat plate is fixed in the valve housing, which is designed as a screw-in nipple, by a pressure bush, on which a pressure piece screwed into the valve housing and having an inlet bore acts.
  • the valve body has a shaft protruding into the cavity of the pressure sleeve, with which it engages the helical tension spring.
  • the helical tension spring is suspended at the top from an abutment which is supported on a shoulder provided at the upper end of the pressure bush.
  • the stem of the valve body is passed through a disc clamped between the pressure sleeve and the valve seat plate, which has a radial slot for mounting the stem.
  • the fuel can pass through to the valve seat through this slot and through axial bores in the disk.
  • the said disk serves to limit the stroke of the valve body, the stem of which strikes a shoulder on the disk.
  • This injector is particularly complicated in construction due to the separate stroke limiting disk and cumbersome in assembly and maintenance.
  • the injector must be completely disassembled to access the valve.
  • an injection nozzle was known from DE-OS 3 139 948, in which, however, the stop limiting the stroke of the valve plate is at a very considerable distance from the valve plate.
  • the valve plate has a larger diameter than the valve stem, which has an annular groove immediately above the valve plate, in which transverse bores end, which establish a connection to a central blind hole through which the fuel can be supplied.
  • the stop is formed by a sleeve held in the upper region of the valve stem, which is acted upon by a spring and is supported via intermediate elements on an O-ring held on the valve stem.
  • This injector also has the disadvantage that the valve is only accessible when the injector is practically completely disassembled, which results in a correspondingly high level of maintenance.
  • the relatively large distance between the stop and the valve seat results in an undesirable considerable thermal influence on the largest opening gap of the valve.
  • the object of the invention is to propose an injection nozzle of the type mentioned at the outset which avoids the disadvantages of the known designs and which, while ensuring the largest opening gap, is distinguished by a simple structure, simple assembly and a high degree of ease of maintenance.
  • this is achieved in that two radial projections on the valve housing are integral with this and form recesses in the valve housing, and two projections on the valve stem each diametrically opposite extend over less than 90 degrees and the axial coverage of these projections after insertion of the valve stem in the valve housing is reached through the recesses by turning the valve stem.
  • the stop can be easily manufactured with the necessary accuracy. Different thermal expansions from the valve stem and valve housing can only have a minor effect on the maximum valve lift. The result is a simple design and simple installation and maintenance options.
  • plate springs which are arranged coaxially to the valve stem and which are supported on the valve housing on the one hand and on nuts screwed onto the valve stem on the other hand can be provided on the end of the valve stem opposite the valve stem.
  • the disc springs can also be used to secure the valve stem against rotation by, according to a further feature of the invention, by providing the valve stem with a flattened portion on the one hand and a corresponding recess in the disc spring resting on the valve housing and, on the other hand, a pin for securing this disc spring against the valve housing is provided.
  • a filter for the fuel can be provided between the access of the fuel to the valve and the exit from the valve be formed in the valve housing, which is smaller than the maximum valve lift.
  • the injection nozzle according to the invention shown in FIGS. 1 to 3 consists of the valve housing 1, in which the valve stem 2 is axially slidably supported with play. At its lower end, the valve stem 2 has a valve disk 3 with a conical seat surface 4, the cone angle of which is denoted by 5 and is approximately 140 ° in the present example.
  • the injection nozzle is designed so that it opens in the direction of flow due to the pressure of the fuel supplied.
  • two identical plate springs 6 and 7 engage, which should generally be very stiff.
  • the upper part 8 of the valve stem 2 is provided with a thread, preferably a fine thread, and two nuts 9.
  • the maximum stroke of the valve is very small, about one to several hundredths of a millimeter. It is illustrated schematically in the drawing by dimension 10.
  • the stop which limits the maximum stroke 10, is formed by the outward projections 11 on the shaft 2 on the one hand and the inward projections 12 in the valve housing 1 on the other hand.
  • the valve stem 2 can be inserted into the valve housing 1 through corresponding recesses 13, which must be slightly larger than the projections 11, so that the projections 11 come to rest on the side of the projections 12 facing away from the valve disk 3.
  • the valve stem 2 is now rotated by 90 ° , so that the projections 11 on the valve stem 2 and the projections 12 in the valve housing 1 overlap in the axial direction and in this way result in the stroke limitation.
  • the plate spring 7 is used, which has an opening 14 for the flattened 15 upper part of the valve stem 2 and is also prevented by the pin 16 from rotating relative to the valve housing 1.
  • the pressure pipe coming from the injection pump (not shown) is connected in the bore 17, from there the fuel is supplied via the bore 18 to the annular groove 19 which is arranged in the valve stem 2.
  • the fuel is supplied to the annular groove 21 via the valve disk 3.
  • the number of grooves 20 to be carried out axially is to be selected so that the distribution on the circumference becomes sufficiently uniform.
  • the leak fuel is supplied to the leak fuel drain 24 via the bore 23.
  • FIG. 4 shows an embodiment according to the invention in which the upper contour of the inlet into the valve gap is rounded in contrast to the embodiment according to FIG. 1. In this way, the location of the highest fuel speed is moved in the vicinity of the exit of the jet, as a result of which a larger part of the pressure energy is converted into kinetic energy of the jet.
  • FIG. 5 differs from that of FIG. 1 in that the axially extending grooves between the annular grooves 19 and 25 are not continuous, but that axial grooves 26 and 27 are provided, which alternate from the upper annular groove 19 and the lower annular groove 25 go out and each end in front of the other annular groove.
  • the fuel is forced to take the path via the clearance between the valve stem 2 and the valve housing 21.
  • This game is dimensioned smaller than the maximum valve stroke 10, so that dirt particles are retained which could clog the valve gap.

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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

Die Erfindung bezieht sich auf eine Einspritzdüse für Brennkraftmaschinen, insbesondere Dieselmotoren, mit einem durch den Kraftstoffdruck in Strömungsrichtung mit sehr geringem Hub öffnenden, aus Ventilteller und Ventilschaft bestehendem Tellerventil, wobei der Hub des Tellerventiles durch einen Anschlag begrenzt ist, der in der Nähe des Ventiltellers vorgesehen ist und durch Vorsprünge gebildet ist, die am Ventilgehäuse nach innen und am Ventilschaft nach außen vorgesehen sind, wobei die einander zugewandten Kontaktflächen dieser Vorsprünge bei geschlossenem Ventil um den gewünschten maximalen Hub voneinander abstehen.The invention relates to an injection nozzle for internal combustion engines, in particular diesel engines, with a poppet valve which consists of a valve disk and valve stem and which opens due to the fuel pressure in the flow direction with a very small stroke, the stroke of the poppet valve being limited by a stop which is in the vicinity of the valve disk is provided and is formed by projections which are provided on the inside of the valve housing and on the outside of the valve stem, the mutually facing contact surfaces of these projections projecting from one another by the desired maximum stroke when the valve is closed.

Eine solche Einspritzdüse dient zur gleichmäßigen Verteilung des Kraftstoffes längs des Umfanges eines wenigstens annähernd rotationsförmigen Brennraumes, wobei die Einspritzdüse etwa in der Achse des Brennraumes angeordnet ist.Such an injection nozzle is used for uniform distribution of the fuel along the circumference of an at least approximately rotationally shaped combustion chamber, the injection nozzle being arranged approximately in the axis of the combustion chamber.

Der Kraftstoff tritt dabei aus der Einspritzdüse in Form eines Kegelmantels mit sehr kleiner Wandstärke aus; er bietet der relativ wenig bewegten Verbrennungsluft im Brennraum eine sehr große Angriffsfläche. Da er sich mit großer Geschwindigkeit beim Einspritzen gegen den Umfang des Brennraumes bewegt, entsteht eine starke Reibung zwischen dem Kraftstoff und der Luft, die den Kraftstoff in kleinste Tröpfchen zerteilt. Die Luft wird durch den Impuls des mit hoher Geschwindigkeit bewegten Kraftstoffes in der Richtung zum Umfang des Brennraumes nach den Stoßgesetzen beschleunigt, wodurch Strömungen im Brennraum entstehen, die von der Einspritzdüse an den Umfang gerichtet sind und sodann vom Umfang gegen die Einspritzdüse führen. Der Winkel des Kraftstoffmantels im Brennraum und dieser selbst sind so aufeinander abzustimmen, daß eine gieichmäßige Mischung von Kraftstoff und Luft eintritt. Der Offnungswinkel des eingespritzten Kraftstoff-Kegelmantels beträgt hierbei mindestens 90°, vorzugsweise 120 bis 160°. Der Hub des Ventiltellers ist dementsprechend sehr klein, etwa in der Größenordnung von einem oder mehreren hundertstel Millimeter.The fuel emerges from the injection nozzle in the form of a cone jacket with a very small wall thickness; it offers the relatively little moving combustion air in the combustion chamber a very large target. As it moves against the circumference of the combustion chamber at high speed during injection, there is a strong friction between the fuel and the air, which splits the fuel into tiny droplets. The air is accelerated by the impulse of the fuel moving at high speed in the direction of the circumference of the combustion chamber in accordance with the impact laws, which creates flows in the combustion chamber which are directed from the injection nozzle to the circumference and then lead from the circumference against the injection nozzle. The angle of the fuel jacket in the combustion chamber and this itself must be coordinated so that an equal mixture of fuel and air occurs. The opening angle of the injected fuel cone jacket is at least 90 ° , preferably 120 to 160 ° . The stroke of the valve plate is accordingly very small, approximately in the order of magnitude of one or several hundredths of a millimeter.

Eine Einspritzdüse der eingangs genannten Art ist durch die DE-C 933 003 bekannt. Dabei ist ein kegeliger Ventilkörper, allerdings mit spitzem, Kegelwinkel, vorgesehen, der mit einem entsprechend kegelig ausgebildeten Ventilsitz in einer, Ventilsitzplatte zusammenarbeitet. Der Ventilkörper öffnet durch den Kraftstoffdruck in Strömungsrichtung und unter Überwindung der Kraft einer Schraubenzugfeder. Die Ventilsitzplatte ist in dem als Einschraubnippel ausgebildeten Ventilgehäuse durch eine Druckbüchse auf die ein in das Ventilgehäuse eingeschraubtes, eine Zulaufbohrung aufweisendes Druckstück wirkt, festgelegt. Der Ventilkörper weist einen in den Hohlraum der Druckbüchse hineinragenden Schaft auf, mit dem er an der Schraubenzugfeder angreift. Die Schraubenzugfeder ist oben an einem Widerlager aufgehängt, das sich auf einem am oberen Ende der Druckbüchse vorgesehenen Absatz abstützt. Der Schaft des Ventilkörpers ist durch eine zwischen die Druckbüchse und die Ventilsitzplatte eingeklemmte Scheibe hindurchgeführt, die zur Montage des Schaftes einen radialen Schlitz aufweist. Durch diesen Schlitz und durch axiale Bohrungen der Scheibe kann der Kraftstoff zum Ventilsitz durchtreten. Die genannte Scheibe dient zur Hubbegrenzung des Ventilkörpers, wobei dessen Schaft an einem Absatz an der Scheibe anschlägt.An injection nozzle of the type mentioned is known from DE-C 933 003. In this case, a conical valve body is provided, but with an acute cone angle, which cooperates with a correspondingly conical valve seat in one valve seat plate. The valve body opens due to the fuel pressure in the direction of flow and overcomes the force of a coil spring. The valve seat plate is fixed in the valve housing, which is designed as a screw-in nipple, by a pressure bush, on which a pressure piece screwed into the valve housing and having an inlet bore acts. The valve body has a shaft protruding into the cavity of the pressure sleeve, with which it engages the helical tension spring. The helical tension spring is suspended at the top from an abutment which is supported on a shoulder provided at the upper end of the pressure bush. The stem of the valve body is passed through a disc clamped between the pressure sleeve and the valve seat plate, which has a radial slot for mounting the stem. The fuel can pass through to the valve seat through this slot and through axial bores in the disk. The said disk serves to limit the stroke of the valve body, the stem of which strikes a shoulder on the disk.

Diese Einspritzdüse ist insbesondere wegen der separaten Hubbegrenzungsscheibe kompliziert im Aufbau und umständlich in der Montage und in der Wartung. Die Einspritzdüse muß vollständig zerlegt werden, um zum Ventil zu gelangen.This injector is particularly complicated in construction due to the separate stroke limiting disk and cumbersome in assembly and maintenance. The injector must be completely disassembled to access the valve.

Weiters wurde durch die DE-OS 3 139 948 eine Einspritzdüse bekannt, bei der allerdings der den Hub des Ventiltellers begrenzende Anschlag einen sehr erheblichen Abstand vom Ventilteller aufweist. Bei dieser Düse weist der Ventilteller einen größeren Durchmesser als der Ventilschaft auf, der unmittelbar oberhalb des Ventiltellers eine Ringnut aufweist, in der Querbohrungen enden, die eine Verbindung zu einer zentralen Sackbohrung herstellen, über die der Kraftstoff zuführbar ist. Der Anschlag ist dabei durch eine im oberen Bereich des Ventilschaftes gehaltene Hülse gebildet, die von einer Feder beaufschlagt ist und sich über Zwischenelemente an einem am Ventilschaft gehaltenen O-Ring abstützt. Bei dieser Einspritzdüse ergibt sich aber ebenfalls der Nachteil, daß das Ventil nur bei praktisch vollständiger Zerlegung der Einspritzdüse zugänglich ist, woraus ein entsprechend hoher Wartungsaufwand resultiert. Außerdem ergibt sich aufgrund des relativ großen Abstandes zwischen dem Anschlag und dem Ventilsitz eine unerwünschte beträchtliche thermische Beeinflussung des größten Öffnungsspaltes des Ventiles.Furthermore, an injection nozzle was known from DE-OS 3 139 948, in which, however, the stop limiting the stroke of the valve plate is at a very considerable distance from the valve plate. In this nozzle, the valve plate has a larger diameter than the valve stem, which has an annular groove immediately above the valve plate, in which transverse bores end, which establish a connection to a central blind hole through which the fuel can be supplied. The stop is formed by a sleeve held in the upper region of the valve stem, which is acted upon by a spring and is supported via intermediate elements on an O-ring held on the valve stem. This injector also has the disadvantage that the valve is only accessible when the injector is practically completely disassembled, which results in a correspondingly high level of maintenance. In addition, the relatively large distance between the stop and the valve seat results in an undesirable considerable thermal influence on the largest opening gap of the valve.

Aufgabe der Erfindung ist es, eine Einspritzdüse der eingangs erwähnten Art vorzuschlagen, welche die Nachteile der bekannten Ausführungen vermeidet und die sich unter Sicherstellung des größten Öffnungsspaltes durch einen einfachen Aufbau, eine einfache Montage und durch ein hohes Maß an Wartungsfreundlichkeit auszeichnet.The object of the invention is to propose an injection nozzle of the type mentioned at the outset which avoids the disadvantages of the known designs and which, while ensuring the largest opening gap, is distinguished by a simple structure, simple assembly and a high degree of ease of maintenance.

Gemäß der Erfindung wird dies dadurch erreicht, daß zwei radiale Vorsprünge am Ventilgehäuse mit diesem einstückig sind und Ausnehmungen im Ventilgehäuse bilden, sowie zwei Vorsprünge am Ventilschaft je diametral gegenüberliegend sich über weniger als 90 Winkelgrade erstrecken und die axiale Deckung dieser Vorsprünge nach Einsetzen des Ventilschaftes in das Ventilgehäuse durch die Ausnehmungen durch Verdrehung des Ventilschaftes erreicht wird. Auf diese Weise kann der Anschlag mit der nötigen Genauigkeit auf einfache Weise hergestellt werden. Verschiedene Wärmedehnungen vom Ventilschaft und Ventilgehäuse können sich auf den maximalen Ventilhub nur geringfügig auswirken. Es ergibt sich eine einfache Ausführung und einfache Montage- und Wartungsmöglichkeit.According to the invention, this is achieved in that two radial projections on the valve housing are integral with this and form recesses in the valve housing, and two projections on the valve stem each diametrically opposite extend over less than 90 degrees and the axial coverage of these projections after insertion of the valve stem in the valve housing is reached through the recesses by turning the valve stem. In this way, the stop can be easily manufactured with the necessary accuracy. Different thermal expansions from the valve stem and valve housing can only have a minor effect on the maximum valve lift. The result is a simple design and simple installation and maintenance options.

In weiterer Ausgestaltung der Erfindung können an dem dem Ventilteller gegenüberliegenden Ende des Ventilschaftes koaxial zum Ventilschaft angeordnete Tellerfedern vorgesehen sein, die sich einerseits am Ventilgehäuse und andererseits an auf dem Ventilschaft aufgeschraubte Muttern abstützt. Diese Ausführung gibt eine baulich sehr einfache und zweckmäßige Lösung, weil die leicht montierbaren Tellerfedern für den sehr geringen Maximalhub des Ventils ausreichend sind und in axialer Richtung eine sehr geringe Bauhöhe aufweisen können.In a further embodiment of the invention, plate springs which are arranged coaxially to the valve stem and which are supported on the valve housing on the one hand and on nuts screwed onto the valve stem on the other hand can be provided on the end of the valve stem opposite the valve stem. This design is very structural Simple and expedient solution because the easy-to-assemble disc springs are sufficient for the very small maximum stroke of the valve and can have a very low overall height in the axial direction.

Die Tellerfedern können gleichzeitig auch zur notwendigen Drehsicherung des Ventilschaftes herangezogen werden, indem, nach einem weiteren Merkmal der Erfindung, einerseits der Ventilschaft mit einer Abflachung und die am Ventilgehäuse aufliegende Tellerfeder mit einer dementsprechenden Ausnehmung versehen und andererseits ein Stift zur Drehsicherung dieser Tellerfeder gegenüber dem Ventilgehäuse vorgesehen ist.The disc springs can also be used to secure the valve stem against rotation by, according to a further feature of the invention, by providing the valve stem with a flattened portion on the one hand and a corresponding recess in the disc spring resting on the valve housing and, on the other hand, a pin for securing this disc spring against the valve housing is provided.

Vorteilhaft kann zwischen dem Zutritt des Kraftstoffes zum Ventil und dem Austritt aus dem Ventil ein Filter für den Kraftstoff vorgesehen sein, das durch abwechselnd von einer oberen und einer unteren Ringnut ausgehenden und jeweils vor der anderen Ringnut endenden axialen Nuten am Ventilschaft und ein Spiel des Ventilschaftes im Ventilgehäuse gebildet sein, das kleiner ist als der maximale Ventilhub. Dadurch wird auf einfache und zuverlässige Weise die angestrebte Filterwirkung erzielt und ein Verstopfen des sehr kleinen Ventilspaltes vermieden.Advantageously, a filter for the fuel can be provided between the access of the fuel to the valve and the exit from the valve be formed in the valve housing, which is smaller than the maximum valve lift. As a result, the desired filter effect is achieved in a simple and reliable manner and clogging of the very small valve gap is avoided.

Die Erfindung wird nachfolgend anhand der Zeichnung näher erläutert . Es zeigen:

  • Figur 1 eine erfindungsgemäße Einspritzdüse im Axialschnitt,
  • Figur 2 einen Schnitt gemäß der Linie 11-11 in Figur 1,
  • Figur 3 einen Schnitt gemäß der Linie 111-111 in Figur 1,
  • Figur 4 ein Detail einer anderen Ausführungsform in vergrößerter Darstellung und
  • Figur 5 den Ventilschaft einer, weiteren Ausführungsform mit weggeschnittenem Mittelteil.
The invention is explained below with reference to the drawing. Show it:
  • FIG. 1 shows an injection nozzle according to the invention in axial section,
  • FIG. 2 shows a section along the line 11-11 in FIG. 1,
  • FIG. 3 shows a section along the line 111-111 in FIG. 1,
  • Figure 4 shows a detail of another embodiment in an enlarged view and
  • 5 shows the valve stem of a further embodiment with the central part cut away.

Gleiche Teile sind mit den selben Bezugszeichen versehen.The same parts are provided with the same reference numerals.

Die in Fig. 1 bis 3 dargestellte erfindungsgemäße Einspritzdüse besteht aus dem Ventilgehäuse 1, in welchem der Ventilschaft 2 mit Spiel axial gleitbar gelagert ist. An seinem unteren Ende weist der Ventilschaft 2 einen Ventilteller 3 mit einer konischen Sitzfläche 4 auf, deren Konuswinkel mit 5 bezeichnet ist und beim vorliegenden Beispiel etwa 140° beträgt. Die Einspritzdüse ist so gestaltet, daß sie durch den Druck des zugeführten Kraftstoffes in Strömungsrichtung öffnet.The injection nozzle according to the invention shown in FIGS. 1 to 3 consists of the valve housing 1, in which the valve stem 2 is axially slidably supported with play. At its lower end, the valve stem 2 has a valve disk 3 with a conical seat surface 4, the cone angle of which is denoted by 5 and is approximately 140 ° in the present example. The injection nozzle is designed so that it opens in the direction of flow due to the pressure of the fuel supplied.

Am anderen Ende des Ventilschaftes 2 greifen zwei gleichartige Tellerfedern 6 und 7 an, die im allgemeinen sehr steif sein sollen. Zum Anspannen der Tellerfedern 6, 7 ist der obere Teil 8 des Ventilschaftes 2 mit einem Gewinde, vorzugsweise Feingewinde, und zwei Muttern 9 versehen. Der maximale Hub des Ventiles ist sehr klein, etwa in der Größenordnung von ein bis mehreren hundertstel Millimeter zu bemessen. Er ist in der Zeichnung schematisch durch das Maß 10 veranschaulicht.At the other end of the valve stem 2, two identical plate springs 6 and 7 engage, which should generally be very stiff. To tighten the plate springs 6, 7, the upper part 8 of the valve stem 2 is provided with a thread, preferably a fine thread, and two nuts 9. The maximum stroke of the valve is very small, about one to several hundredths of a millimeter. It is illustrated schematically in the drawing by dimension 10.

Der Anschlag, der den maximalen Hub 10 begrenzt, wird durch die nach außen liegenden Vorsprünge 11 am Schaft 2 einerseits und die im Ventilgehäuse 1 nach innen gerichteten Vorsprünge 12 andererseits, gebildet. Den Ventilschaft 2 kann man in das Ventilgehäuse 1 durch entsprechende Ausnehmungen 13, die etwas größer als die Vorsprünge 11 bemessen sein müssen, einstecken, so daß die Vorsprünge 11 auf der, dem Ventilteller 3 abgekehrten Seite der Vorsprünge 12 zu liegen kommen. Beim dargestellten Ausführungsbeispiel dreht man nun den Ventilschaft 2 um 90°, sodaß sich die Vorsprünge 11 am Ventilschaft 2 und die Vorsprünge 12 im Ventilgehäuse 1 in axialer Richtung decken und auf diese Weise die Hubbegrenzung ergeben.The stop, which limits the maximum stroke 10, is formed by the outward projections 11 on the shaft 2 on the one hand and the inward projections 12 in the valve housing 1 on the other hand. The valve stem 2 can be inserted into the valve housing 1 through corresponding recesses 13, which must be slightly larger than the projections 11, so that the projections 11 come to rest on the side of the projections 12 facing away from the valve disk 3. In the illustrated embodiment, the valve stem 2 is now rotated by 90 ° , so that the projections 11 on the valve stem 2 and the projections 12 in the valve housing 1 overlap in the axial direction and in this way result in the stroke limitation.

Zur Sicherung gegen Verdrehung des Ventilschaftes 2 aus dieser Lage dient die Tellerfeder 7, welche eine Durchbrechung 14 für den mit Abflachungen 15 versehenen oberen Teil des Ventilschaftes 2 aufweist und außerdem durch den Stift 16 am Verdrehen gegenüber dem Ventilgehäuse 1 verhindert wird.To secure against rotation of the valve stem 2 from this position, the plate spring 7 is used, which has an opening 14 for the flattened 15 upper part of the valve stem 2 and is also prevented by the pin 16 from rotating relative to the valve housing 1.

Das von der nicht dargestellten Einspritzpumpe kommende Druckrohr ist in der Bohrung 17 angeschlossen, von dort wird der Kraftstoff über die Bohrung 18 der Ringnut 19 zugeführt, die im Ventilschaft 2 angeordnet ist. Durch die Nuten 20, die am Umfang des Ventilschaftes 2 in axialer Richtung angebracht sind, wird der Kraftstoff der Ringnut 21 über dem Ventilteller 3 zugeführt. Die Anzahl der axial auszuführenden Nuten 20 ist so zu wählen, daß die Verteilung am Umfang genügend gleichmäßig wird. Durch die Ringnut 22 wird der Leckkraftstoff über die Bohrung 23 dem Leckkraftstoffabfluß 24 zugeführt.The pressure pipe coming from the injection pump (not shown) is connected in the bore 17, from there the fuel is supplied via the bore 18 to the annular groove 19 which is arranged in the valve stem 2. Through the grooves 20, which are attached to the circumference of the valve stem 2 in the axial direction, the fuel is supplied to the annular groove 21 via the valve disk 3. The number of grooves 20 to be carried out axially is to be selected so that the distribution on the circumference becomes sufficiently uniform. Through the annular groove 22, the leak fuel is supplied to the leak fuel drain 24 via the bore 23.

Der Kegelwinkel 5 des Kraftstoffmantels im Brennraum und dieser selbst sind so aufeinander abzustimmen, daß eine gleichmäßige Mischung von Kraftstoff und Luft eintritt. In Fig. 4 ist eine Ausführung gemäß der Erfindung dargestellt, bei der die obere Kontur des Einlaufes in den Ventilspalt im Gegensatz zur Ausführung gemäß Fig. 1 abgerundet ist. Auf diese Weise wird die Stelle höchster Kraftstoffgeschwindigkeit in die Nähe des Austrittes des Strahles verlegt, wodurch ein größerer Teil der Druckenergie in kinetische Energie des Strahles umgesetzt wird.The cone angle 5 of the fuel jacket in the combustion chamber and this itself must be coordinated so that a uniform mixture of fuel and air occurs. FIG. 4 shows an embodiment according to the invention in which the upper contour of the inlet into the valve gap is rounded in contrast to the embodiment according to FIG. 1. In this way, the location of the highest fuel speed is moved in the vicinity of the exit of the jet, as a result of which a larger part of the pressure energy is converted into kinetic energy of the jet.

Die Ausführung des Ventilschaftes 2 gemäß Fig. 5 unterscheidet sich von jener nach Fig. 1 dadurch, daß die axial verlaufenden Nuten zwischen den Ringnuten 19 und 25 nicht durchgehend sind, sondern daß axiale Nuten 26 und 27 vorgesehen sind, die abwechselnd von der oberen Ringnut 19 und der unteren Ringnut 25 ausgehen und jeweils vor der anderen Ringnut enden. Dadurch wird der Kraftstoff gezwungen, den Weg über den Spielraum zwischen dem Ventilschaft 2 und dem Ventilgehäuse 21 zu nehmen. Dieses Spiel ist kleiner bemessen als der maximale Ventilhub 10, so daß Schmutzteilchen zurückgehalten werden, welche den Ventilspalt verstopfen könnten.5 differs from that of FIG. 1 in that the axially extending grooves between the annular grooves 19 and 25 are not continuous, but that axial grooves 26 and 27 are provided, which alternate from the upper annular groove 19 and the lower annular groove 25 go out and each end in front of the other annular groove. As a result, the fuel is forced to take the path via the clearance between the valve stem 2 and the valve housing 21. This game is dimensioned smaller than the maximum valve stroke 10, so that dirt particles are retained which could clog the valve gap.

Claims (3)

1. An injection nozzle for internal combustion engines, especially diesel engines, with a poppet valve comprising a valve disk and a valve stem, the lift of said poppet valve being very small upon opening on account of the fuel pressure in the direction of flow, and being limited by a stop, which is located in the vicinity of the valve disk and is formed by projections extending inwards on the valve cage and outwards on the valve stem, the adjacent contact faces of said projections being separated by the desire maximum lift when the valve is closed, wherein two radial projections on the valve cage are cast integral with the latter and form recesses in the valve cage, and wherein two projections on the valve stem are positioned diametrically opposite each other, subtending an angle of less than 90 degrees, axial alignment of said projections being obtained by turning the valve stem after it has been inserted into the valve cage through the recesses.
2. An injection nozzle according to claim 1, wherein cup springs are provided on the end of the valve stem opposite of the valve disk, whose position is coaxial with the valve stem, and which are supported by the valve cage on the one side and by the nuts fastened on the valve stem on the other side.
3. An injection nozzle according to claim 2, wherein the valve stem is secured against turning by the cooperation of a flattened portion of the valve stem and a corresponding recess of the cup spring resting on the valve cage on the one hand, and by a pin for arresting the cup spring against turning relative to the valve cage on the other hand.
EP19870890095 1986-05-13 1987-05-12 Injection nozzle for internal-combustion engines, particularly for diesel engines Expired EP0246220B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT1277/86 1986-05-13
AT127786A AT395638B (en) 1986-05-13 1986-05-13 INJECTION NOZZLE FOR INTERNAL COMBUSTION ENGINES, ESPECIALLY DIESEL ENGINES

Publications (2)

Publication Number Publication Date
EP0246220A1 EP0246220A1 (en) 1987-11-19
EP0246220B1 true EP0246220B1 (en) 1989-09-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870890095 Expired EP0246220B1 (en) 1986-05-13 1987-05-12 Injection nozzle for internal-combustion engines, particularly for diesel engines

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EP (1) EP0246220B1 (en)
AT (1) AT395638B (en)
DE (1) DE3760630D1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4034203C2 (en) * 1990-10-27 1995-02-09 Rinsum Cornelis Van Dipl Ing Fuel injection nozzle for internal combustion engines
DE4322313A1 (en) * 1993-07-05 1995-01-12 Kanis Paul Gerhard Dipl Ing Vibrating-plunger nozzle
DE19719295A1 (en) * 1997-05-07 1998-11-12 Bosch Gmbh Robert Fuel injection valve for internal combustion engines
DE102006053556A1 (en) * 2006-11-14 2008-05-15 Purem Abgassysteme Gmbh & Co. Kg Device for dosing reducing agent and injector in a device for dosing reducing agent

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE475116C (en) * 1925-01-21 1929-04-19 Deckel Friedrich Method and device for injecting fuel in internal combustion engines
GB400539A (en) * 1932-05-21 1933-10-26 Bosch Robert Improvements in or relating to fuel injection nozzles for internal combustion engines
US1985289A (en) * 1932-07-18 1934-12-25 Aerol Engine Corp Injector for internal combustion engines
US2263197A (en) * 1939-03-08 1941-11-18 Eisemann Magneto Corp Fuel injection nozzle
GB539856A (en) * 1940-02-19 1941-09-26 Ex Cell O Corp Improvements in or relating to fuel-injection nozzles for internal-combustion engines
DE933003C (en) * 1954-03-19 1955-09-15 Rudolf Dipl-Ing Schenk Injection valve for internal combustion engines
DE1086487B (en) * 1955-03-22 1960-08-04 Borg Warner Fuel injector
FR1169811A (en) * 1956-04-16 1959-01-06 Mowag Motorwagenfabrik Ag Nozzle
DE3139948A1 (en) * 1981-10-08 1983-04-28 Robert Bosch Gmbh, 7000 Stuttgart Fuel injection nozzle for internal combustion engines
DE3410476A1 (en) * 1983-08-13 1985-02-21 Robert Bosch Gmbh, 7000 Stuttgart Fuel injection nozzle for internal combustion engines

Also Published As

Publication number Publication date
ATA127786A (en) 1992-06-15
DE3760630D1 (en) 1989-11-02
AT395638B (en) 1993-02-25
EP0246220A1 (en) 1987-11-19

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