EP0418800B1 - Fuel injection apparatus for an internal combustion engine - Google Patents

Fuel injection apparatus for an internal combustion engine Download PDF

Info

Publication number
EP0418800B1
EP0418800B1 EP90117905A EP90117905A EP0418800B1 EP 0418800 B1 EP0418800 B1 EP 0418800B1 EP 90117905 A EP90117905 A EP 90117905A EP 90117905 A EP90117905 A EP 90117905A EP 0418800 B1 EP0418800 B1 EP 0418800B1
Authority
EP
European Patent Office
Prior art keywords
injection
main
pump
piston
line
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 - Lifetime
Application number
EP90117905A
Other languages
German (de)
French (fr)
Other versions
EP0418800A2 (en
EP0418800A3 (en
Inventor
Helmut Nieth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LOrange GmbH
Original Assignee
LOrange GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by LOrange GmbH filed Critical LOrange GmbH
Publication of EP0418800A2 publication Critical patent/EP0418800A2/en
Publication of EP0418800A3 publication Critical patent/EP0418800A3/en
Application granted granted Critical
Publication of EP0418800B1 publication Critical patent/EP0418800B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/06—Pumps peculiar thereto
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/46—Valves
    • F02M59/462—Delivery valves

Definitions

  • the invention relates to a fuel injection device for an internal combustion engine with an injection pump for delivering a main injection quantity via a main injection line and with a pre-injection piston chamber coupled to a pre-injection line, in which a pre-injection piston operated hydraulically by the injection pump against a spring force works.
  • a fuel injection device in which an ignitable main fuel, for example alcohol in a main injection and another ignition fuel is supplied in a pre-injection of the internal combustion engine.
  • Two separate fuel supply lines in particular two fuel tanks and two fuel pumps, are required to operate the internal combustion engine.
  • the pre-injection takes place in that the pressure impressed on the unwanted fuel in the injection pump moves the pre-injection piston against its spring force, so that the pre-injection line and a nozzle are conveyed into a combustion chamber of the internal combustion engine.
  • the main disadvantage of this arrangement is too see that a separate feed pump is required for filling the pre-injection piston chamber.
  • a further fuel injection device for an internal combustion engine with an injection pump for delivering a main injection quantity via a main injection line and with a pre-injection piston chamber coupled to a pre-injection line, in which a pre-injection piston operated hydraulically by the injection pump against a spring force works.
  • a main valve is formed by the pre-injection piston, which is mounted coaxially and slidably in a storage piston that determines the start of the main injection.
  • the geometry and spring force of the pre-injection piston are matched so that the pre-injection quantity is delivered before the main valve opens.
  • This arrangement also uses a separate low-pressure feed pump to deliver the pre-injection quantity into the pre-injection piston chamber.
  • a major advantage of the device according to the invention is that the fuel supply to the pre-injection piston chamber is provided in a simple manner via the connecting channel from the fuel volume in the main injection line when the main valve is closed after the main injection has ended. This advantageously eliminates the need for a separate low-pressure feed pump for the pre-injection quantity of the fuel, because the The pre-injection piston chamber is filled using the amount of fuel in the main injection line.
  • a pressure line is provided from the pump chamber of the injection pump to the end face of the pre-injection piston on the pump chamber side.
  • This end face is preferably larger than the effective cross section of the pressure line.
  • the length of the pre-injection line and the main injection line are preferably matched to one another in order to achieve a desired spread between the pre-injection and the main injection.
  • Another advantageous embodiment of the invention provides that the opening pressures of the pre-injection valve and the main injection valve are matched to one another in order to achieve a desired spread between the pre-injection and the main injection.
  • Another advantage is that the injection pump, the main pressure valve and the pre-injection piston chamber form a compact structural unit.
  • the number and size of the devices to be attached to the motor can thus be minimized as far as possible.
  • FIG. 1 schematically shows the fuel injection device 1, which essentially consists of an injection pump 2 and an injection quantity distribution head 3 flanged onto it.
  • a pre-injection line 6 branches off from the injection distributor head 3, which in turn is coupled to a pre-injection valve 7.
  • the injection pump 2 shows the fuel injection device 1 consisting of the injection pump 2 and the injection distributor head 3 mounted therein in a schematic longitudinal section.
  • the injection pump 2 consists of a pump housing 8 in which a piston guide 9 is fitted. Between the pump housing 8 and the piston guide 9, an annular suction space 10 is let in, which communicates with a fuel reservoir, not shown.
  • the piston guide 9 has a central pump chamber 11, in which a pump piston 12 can be moved in an oscillating manner. The pump piston 12 is moved in an oscillating manner via cam kinematics (not shown).
  • the pump chamber 11 is connected to the suction chamber 10 via control bores 13, fuel being sucked out of the suction chamber 10 into the pump chamber 11 via the control bores 13 when the pump piston 12 moves downward.
  • the pump piston 12 has control edges 14 and 15, by means of which the start and end of the pressure stroke can be controlled in a known manner.
  • the pump piston 12 can be rotated in the circumferential direction by a certain angle in a known manner.
  • the pump chamber 11 is connected via a main bore 16 to a main injection line 4, a main valve 18 being provided between the main bore 16 and the main injection line 4, which has a lock cylinder 19 which is pressed by a compression spring 20 against an annular sealing shoulder 21 to close the main bore 16 is.
  • a pre-injection piston chamber 22 is also provided, which is closed off from the pressure pump chamber 11 by the pre-injection piston 23.
  • the pre-injection piston 23 is pressed against a second sealing shoulder 25 via the compression spring 24.
  • the pressure line 26 connected to the pump chamber 11 has a smaller diameter and thus a smaller area than the end face of the pre-injection piston 23.
  • the pre-injection piston chamber 22 is also connected on the one hand to a pre-injection line 6, which, as can be seen from FIG. 1, is coupled to the pre-injection valve 7.
  • the pre-injection piston chamber 22 is connected to the main injection line 4 via the connecting channel 27.
  • the pump chamber 11 is also connected via an overpressure bore 28 to an overpressure valve 29 connected anti-parallel to the main valve 18, the pressure side of the overpressure valve 29 communicating with the main injection line 4 by means of the line 30.
  • the mode of operation of the fuel injection device according to the invention is as follows:
  • the pump piston 12 is - as shown in FIG. 2 - at its bottom dead center.
  • the filling process of fuel from the suction chamber 10 via the control bores 13 into the pump chamber 11 is complete, ie it is filled with fuel.
  • the pump piston 12 then moves back into the pump chamber 11, with no pressure building up in the pump chamber 11 until the front control edge 14 of the pump piston 12 has closed the control bores 13. Up to this point, part of the fuel flows back into the suction chamber 10.
  • the locking cylinder 19 of the main valve 18 and the pre-injection piston 23 are meanwhile held in their lower end position by the common stand pressure in the injection lines 4 and 6 and by the spring force of the compression springs 20 and 24, the locking cylinder 19 facing the main bore 16 along the sealing shoulder 21 Main injection line 4 seals.
  • the pressure in the pump chamber required to open the pre-injection piston 23 only acts on the area formed by the sealing cross-section of the pressure line 26 and must therefore be greater than the standing pressure of the injection lines 4 and 6, which acts on the larger area of the sealing shoulder 25 and additionally by the force of the Compression spring 24 is supported.
  • the pre-injection piston 23 jumps up and generates a pressure wave that propagates via the pre-injection line 6 to the pre-injection valve 7.
  • the pre-injection piston 23 moves against the force of the compression spring 24, displacing the fuel located in the pre-injection piston chamber 22, primarily into the pre-injection line 6 until its annular sealing flange 31 bears against the sealing surface 32 of the injection distributor head 3.
  • the connecting channel 27 is closed, so that the pre-injection line 6 is sealed off from the main injection line 4.
  • the fuel quantity of the pre-injection is determined by the stroke of the pre-injection piston 23.
  • the amount of fuel in the pump chamber 11 does not yet have a drain option at the time of the pre-injection, so that the pressure in the pump chamber 11 builds up even further. This continues until the delivery pressure also overcomes the counterforces at the lock cylinder 19 from stand pressure in the main injection line 4 and spring force of the compression spring 20.
  • the lock cylinder 19 then moves upwards to its upper stop 33 and the main injection quantity is delivered from the pump chamber 11 via the main bore 16 and a channel system 34 in the interior of the lock cylinder to the main injection line 4, from which the injection takes place via the main injection valve 5.
  • the main injection takes place after completion of the pre-injection and upward movement of the lock cylinder 19 until the rear control edge 15 of the pump piston 12 connects the pump chamber 11 to the control bore 13 again, so that the remaining fuel escapes into the suction chamber 10 again.
  • the pressure difference between the pump chamber 11 and the main injection line 4 can be set by the pressure relief valve 29 installed antiparallel to the main valve 18. After a certain pressure drop through the opening of the control bores 13, the lock cylinder 19 moves downward and seals the main injection line 4 against the pump chamber 11 on the sealing shoulder 21. Until the stand pressure in the injection lines 4 and 6 has set, the pilot injection piston 23 has returned to its lower end position due to the force of the compression spring 24 and the pressure difference between the injection lines 4 and 6 and the pump chamber 11.
  • the pre-injection piston chamber 22 fills with fuel that flows from the main injection line 4 into the pre-injection piston chamber 22 via the connecting channel 27. In parallel, fuel flows from the main injection line 4 until the set stand pressure at the pressure relief valve 29 is reached via the pressure relief hole 28 back into the pump chamber 11. When the pump piston 12 passes its top dead center, the suction stroke begins. The pump chamber 11 fills with fuel from the suction chamber 10, provided the control bores 13 are not exactly closed by the pump piston 12. After passing through the bottom dead center by the pump piston 12, the fuel injection device 1 is ready for a new injection process.

Landscapes

  • 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 betrifft eine Brennstoffeinspritzvorrichtung für eine Brennkraftmaschine mit einer Einspritzpumpe zur Förderung einer Haupteinspritzmenge über eine Haupteinspritzleitung und mit einem mit einer Voreinspritzleitung gekoppelten Voreinspritzkolbenraum, in dem ein von der Einspritzpumpe gegen eine Federkraft hydraulisch beaufschlagter Voreinspritzkolben arbeitet.The invention relates to a fuel injection device for an internal combustion engine with an injection pump for delivering a main injection quantity via a main injection line and with a pre-injection piston chamber coupled to a pre-injection line, in which a pre-injection piston operated hydraulically by the injection pump against a spring force works.

Aus der DE-OS 30 02 851 ist eine Brennstoffeinspritzvorrichtung bekannt, bei der ein zündwilliger Hauptkraftstoff, beispielsweise Alkohol in einer Haupteinspritzung und ein anderer Zündkraftstoff in einer Voreinspritzung der Brennkraftmaschine zugeführt wird. Es sind zwei getrennte Kraftstoffzuführungen, insbesondere zwei Kraftstofftanks und zwei Kraftstoffpumpen zum Betrieb der Brennkraftmaschine erforderlich. Die Voreinspritzung erfolgt dabei dadurch, daß der in der Einspritzpumpe dem zündunwilligen Kraftstoff aufgeprägte Druck den Voreinspritzkolben gegen dessen Federkraft bewegt, so daß die Voreinspritzleitung und eine Düse in einen Brennraum der Brennkraftmaschine gefördert wird. Der wesentliche Nachteil dieser Anordnung ist darin zu sehen, daß für die Füllung des Voreinspritzkolbenraumes eine eigene Förderpumpe erforderlich ist.From DE-OS 30 02 851 a fuel injection device is known in which an ignitable main fuel, for example alcohol in a main injection and another ignition fuel is supplied in a pre-injection of the internal combustion engine. Two separate fuel supply lines, in particular two fuel tanks and two fuel pumps, are required to operate the internal combustion engine. The pre-injection takes place in that the pressure impressed on the unwanted fuel in the injection pump moves the pre-injection piston against its spring force, so that the pre-injection line and a nozzle are conveyed into a combustion chamber of the internal combustion engine. The main disadvantage of this arrangement is too see that a separate feed pump is required for filling the pre-injection piston chamber.

Aus der DE-A 33 34 619 ist eine weitere Brennstoffeinspritzvorrichtung für eine Brennkraftmaschine bekannt, mit einer Einspritzpumpe zur Förderung einer Haupteinspritzmenge über eine Haupteinspritzleitung und mit einem mit einer Voreinspritzleitung gekoppelten Voreinspritzkolbenraum, in dem ein von der Einspritzpumpe gegen eine Federkraft hydraulisch beaufschlagter Voreinspritzkolben arbeitet. Durch den Voreinspritzkolben, welcher koaxial und gleitverschieblich in einem den Beginn der Haupteinspritzung bestimmenden Speicherkolben gelagert ist, wird ein Hauptventil gebildet. Die Geometrie und Federkraft des Voreinspritzkolbens ist so abgestimmt, daß die Förderung der Voreinspritzmenge vor Öffnung des Hauptventils erfolgt. Auch diese Anordnung verwendet für die Förderung der Voreinspritzmenge in den Voreinspritzkolbenraum eine gesonderte Niederdruckförderpumpe.From DE-A 33 34 619 a further fuel injection device for an internal combustion engine is known, with an injection pump for delivering a main injection quantity via a main injection line and with a pre-injection piston chamber coupled to a pre-injection line, in which a pre-injection piston operated hydraulically by the injection pump against a spring force works. A main valve is formed by the pre-injection piston, which is mounted coaxially and slidably in a storage piston that determines the start of the main injection. The geometry and spring force of the pre-injection piston are matched so that the pre-injection quantity is delivered before the main valve opens. This arrangement also uses a separate low-pressure feed pump to deliver the pre-injection quantity into the pre-injection piston chamber.

Hiervon ausgehend ist es Aufgabe der vorliegenden Erfindung, eine Brennstoffeinspritzvorrichtung der eingangs bezeichneten Art anzugeben, mittels der eine getrennte Vor- und Haupteinspritzung von Brennstoff erzielbar ist, ohne daß eine separate Niederdruckeinspritzpumpe für die Voreinspritzmenge erforderlich ist. Weiterhin soll eine konstruktiv möglichst einfache Ausführung geschaffen werden.Proceeding from this, it is an object of the present invention to provide a fuel injection device of the type mentioned at the outset, by means of which separate pre-injection and main injection of fuel can be achieved without the need for a separate low-pressure injection pump for the pre-injection quantity. Furthermore, the design should be as simple as possible in terms of construction.

Erfindungsgemäß wird die Aufgabe durch eine Brennstoffeinspritzvorrichtung mit den Merkmalen des Patentanspruchs 1 gelöst.According to the invention, the object is achieved by a fuel injection device having the features of patent claim 1.

Ein wesentlicher Vorteil der erfindungsgemäßen Vorrichtung ist darin zu sehen, daß die Brennstoffversorgung des Voreinspritzkolbenraumes auf einfache Weise über den Verbindungskanal aus dem in der Haupteinspritzleitung befindlichen Brennstoffvolumen erfolgt, wenn das Hauptventil nach Beendigung der Haupteinspritzung verschlossen ist. Dadurch erübrigt sich vorteilhafterweise eine separate Niederdruckförderpumpe für die Voreinspritzmenge des Brennstoffes, denn die Auffüllung des Voreinspritzkolbenraumes erfolgt über die in der Haupteinspritzleitung befindliche Brennstoffmenge.A major advantage of the device according to the invention is that the fuel supply to the pre-injection piston chamber is provided in a simple manner via the connecting channel from the fuel volume in the main injection line when the main valve is closed after the main injection has ended. This advantageously eliminates the need for a separate low-pressure feed pump for the pre-injection quantity of the fuel, because the The pre-injection piston chamber is filled using the amount of fuel in the main injection line.

In bevorzugter Weiterbildung der Erfindung ist eine Druckleitung vom Pumpenraum der Einspritzpumpe zur pumpenraumseitigen Stirnfläche des Voreinspritzkolbens vorgesehen. Diese Stirnfläche ist vorzugsweise größer als der wirksame Querschnitt der Druckleitung. Bei Erreichen eines bestimmten Schwellendruckes im Pumpenraum, der den Voreinspritzkolben entgegen dessen Federkraft und dem Standdruck im Voreinspritzkolbenraum in Bewegung setzt, wirkt der Pumpenraumdruck nach geringfügigem Anheben des Voreinspritzkolbens schlagartig auf die größere Fläche des ganzen Kolbendurchmessers. Durch das hierdurch erfolgende schlagartige Anwachsen der Druckkraft springt der Voreinspritzkolben auf und erzeugt eine Druckwelle, die sich über die Voreinspritzleitung bis zur Voreinspritzdüse fortpflanzt. Dieses Merkmal der erfindungsgemäßen Vorrichtung beinhaltet den wesentlichen Vorteil der Erfindung: Die Erzeugung einer Druckwelle bestimmter Höhe in der Voreinspritzleitung fast unabhängig von der Drehzahl der Einspritzpumpe.In a preferred development of the invention, a pressure line is provided from the pump chamber of the injection pump to the end face of the pre-injection piston on the pump chamber side. This end face is preferably larger than the effective cross section of the pressure line. When a certain threshold pressure is reached in the pump chamber, which sets the pre-injection piston against its spring force and the static pressure in the pre-injection piston chamber, the pump chamber pressure suddenly affects the larger area of the entire piston diameter after the pre-injection piston has been slightly raised. As a result of the sudden increase in the pressure force, the pre-injection piston springs open and generates a pressure wave that propagates through the pre-injection line to the pre-injection nozzle. This feature of the device according to the invention includes the essential advantage of the invention: the generation of a pressure wave of a certain height in the pre-injection line almost independent of the speed of the injection pump.

Vorzugsweise sind die Voreinspritzleitung und die Haupteinspritzleitung hinsichtlich ihrer Länge zur Erzielung einer gewünschten Spreizung zwischen Vor- und Haupteinspritzung aufeinander abgestimmt.The length of the pre-injection line and the main injection line are preferably matched to one another in order to achieve a desired spread between the pre-injection and the main injection.

Eine weitere vorteilhafte Ausbildung der Erfindung sieht vor, daß die Öffnungsdrücke des Voreinspritzventils und des Haupteinspritzventils zur Erzielung einer gewünschten Spreizung zwischen Vor- und Haupteinspritzung aufeinander abgestimmt sind.Another advantageous embodiment of the invention provides that the opening pressures of the pre-injection valve and the main injection valve are matched to one another in order to achieve a desired spread between the pre-injection and the main injection.

Weiterhin von Vorteil ist, daß die Einspritzpumpe, das Hauptdruckventil und der Voreinspritzkolbenraum eine kompakte bauliche Einheit bilden. Somit läßt sich die Anzahl und Größe der am Motor anzubauenden Vorrichtungen weitestgehend minimieren. Insbesondere sind statt der bisher verwendeten drei Bauteile - Hochdruckeinspritzpumpe, Niederdruckförderpumpe und Kraftstoffeinspritzvorrichtung - nur noch eine einzige, alle drei Funktionen ausführende Vorrichtung erforderlich. Dadurch werden weiterhin die Längen der benötigten Zuleitungen minimiert. Ferner wird der Herstellungs-, Einbau- und Wartungsaufwand gegenüber den bekannten Vorrichtungen reduziert.Another advantage is that the injection pump, the main pressure valve and the pre-injection piston chamber form a compact structural unit. The number and size of the devices to be attached to the motor can thus be minimized as far as possible. In particular, instead of the three components used hitherto - high-pressure injection pump, low-pressure feed pump and fuel injection device - only a single device performing all three functions is required. This further minimizes the lengths of the supply lines required. Furthermore, the manufacturing, installation and maintenance costs are reduced compared to the known devices.

Die Erfindung wird nachfolgend anhand der beigefügten Zeichnung weiter erläutert. Dabei zeigt:

Fig. 1
eine schematische Ansicht der erfindungsgemäßen Brennstoffeinspritzvorrichtung nebst Einspritzventilen,
Fig. 2
einen schematischen Längsschnitt durch die Brennstoffeinspritzvorrichtung.
The invention is further explained below with reference to the accompanying drawing. It shows:
Fig. 1
2 shows a schematic view of the fuel injection device according to the invention together with injection valves,
Fig. 2
a schematic longitudinal section through the fuel injection device.

In Fig. 1 ist schematisch die Brennstoffeinspritzvorrichtung 1 gezeigt, die im wesentlichen aus einer Einspritzpumpe 2 und einem an diesen angeflanschten Einspritzmengenverteilkopf 3 besteht. Mit diesen verbunden ist einerseits eine Haupteinspritzleitung 4, die mit einem Haupteinspritzventil 5 kommuniziert. Weiterhin zweigt vom Einspritzverteilkopf 3 eine Voreinspritzleitung 6 ab, die wiederum mit einem Voreinspritzventil 7 gekoppelt ist.1 schematically shows the fuel injection device 1, which essentially consists of an injection pump 2 and an injection quantity distribution head 3 flanged onto it. A main injection line 4, which communicates with a main injection valve 5, is connected to these on the one hand. Furthermore, a pre-injection line 6 branches off from the injection distributor head 3, which in turn is coupled to a pre-injection valve 7.

In Fig. 2 ist die aus der Einspritzpumpe 2 und dem darin angebrachten Einspritzverteilkopf 3 bestehende Brennstoffeinspritzvorrichtung 1 im schematischen Längsschnitt zu sehen. Die Einspritzpumpe 2 besteht aus einem Pumpengehäuse 8, in dem eine Kolbenführung 9 eingepaßt ist. Zwischen Pumpengehäuse 8 und Kolbenführung 9 ist ein ringförmiger Saugraum 10 eingelassen, der mit einem nicht dargestellten Brennstoffvorratsbehälter kommuniziert. Die Kolbenführung 9 weist einen zentralen Pumpenraum 11 auf, in dem ein Pumpenkolben 12 oszillierend bewegbar ist. Der Pumpenkolben 12 wird über eine nicht dargestellte Nockenkinematik oszillierend bewegt.2 shows the fuel injection device 1 consisting of the injection pump 2 and the injection distributor head 3 mounted therein in a schematic longitudinal section. The injection pump 2 consists of a pump housing 8 in which a piston guide 9 is fitted. Between the pump housing 8 and the piston guide 9, an annular suction space 10 is let in, which communicates with a fuel reservoir, not shown. The piston guide 9 has a central pump chamber 11, in which a pump piston 12 can be moved in an oscillating manner. The pump piston 12 is moved in an oscillating manner via cam kinematics (not shown).

Der Pumpenraum 11 steht über Steuerbohrungen 13 mit dem Saugraum 10 in Verbindung, wobei Brennstoff bei einer abwärtigen Bewegung des Pumpenkolbens 12 aus dem Saugraum 10 über die Steuerbohrungen 13 in den Pumpenraum 11 angesaugt wird. Der Pumpenkolben 12 weist Steuerkanten 14 und 15 auf, mittels denen in bekannter Weise Beginn und Ende des Druckhubes steuerbar sind. Hierzu ist in bekannter Weise der Pumpenkolben 12 in Umfangsrichtung um einen gewissen Winkel drehbar.The pump chamber 11 is connected to the suction chamber 10 via control bores 13, fuel being sucked out of the suction chamber 10 into the pump chamber 11 via the control bores 13 when the pump piston 12 moves downward. The pump piston 12 has control edges 14 and 15, by means of which the start and end of the pressure stroke can be controlled in a known manner. For this purpose, the pump piston 12 can be rotated in the circumferential direction by a certain angle in a known manner.

Der Pumpenraum 11 steht über eine Hauptbohrung 16 mit einer Haupteinspritzleitung 4 in Verbindung, wobei zwischen Hauptbohrung 16 und Haupteinspritzleitung 4 ein Hauptventil 18 vorgesehen ist, das einen Schließzylinder 19 aufweist, der durch eine Druckfeder 20 gegen eine ringförmige Dichtschulter 21 zum Verschließen der Hauptbohrung 16 gedrückt ist.The pump chamber 11 is connected via a main bore 16 to a main injection line 4, a main valve 18 being provided between the main bore 16 and the main injection line 4, which has a lock cylinder 19 which is pressed by a compression spring 20 against an annular sealing shoulder 21 to close the main bore 16 is.

Im Einspritzverteilkopf 3 ist ferner ein Voreinspritzkolbenraum 22 vorgesehen, der gegenüber dem Druckpumpenraum 11 durch den Voreinspritzkolben 23 verschlossen ist. Der Voreinspritzkolben 23 ist über die Druckfeder 24 gegen eine zweite Dichtschulter 25 gedrückt. Die mit dem Pumpenraum 11 verbundene Druckleitung 26 weist dabei einen geringeren Durchmesser und somit eine geringere Fläche auf als die Stirnfläche des Voreinspritzkolbens 23.In the injection distributor head 3, a pre-injection piston chamber 22 is also provided, which is closed off from the pressure pump chamber 11 by the pre-injection piston 23. The pre-injection piston 23 is pressed against a second sealing shoulder 25 via the compression spring 24. The pressure line 26 connected to the pump chamber 11 has a smaller diameter and thus a smaller area than the end face of the pre-injection piston 23.

Der Voreinspritzkolbenraum 22 steht ferner einerseits mit einer Voreinspritzleitung 6 in Verbindung, die, wie aus Fig. 1 ersichtlich, mit dem Voreinspritzventil 7 gekoppelt ist. Außerdem steht der Voreinspritzkolbenraum 22 über den Verbindungskanal 27 mit der Haupteinspritzleitung 4 in Verbindung.The pre-injection piston chamber 22 is also connected on the one hand to a pre-injection line 6, which, as can be seen from FIG. 1, is coupled to the pre-injection valve 7. In addition, the pre-injection piston chamber 22 is connected to the main injection line 4 via the connecting channel 27.

Der Pumpenraum 11 ist ferner über eine Überdruckbohrung 28 mit einem antiparallel zum Hauptventil 18 geschalteten Überdruckventil 29 verbunden, wobei die Druckseite des Überdruckventils 29 mittels der Leitung 30 mit der Haupteinspritzleitung 4 kommuniziert.The pump chamber 11 is also connected via an overpressure bore 28 to an overpressure valve 29 connected anti-parallel to the main valve 18, the pressure side of the overpressure valve 29 communicating with the main injection line 4 by means of the line 30.

Die Wirkungsweise der erfindungsgemäßen Brennstoffeinspritzvorrichtung ist wie folgt: Der Pumpenkolben 12 befinde sich - wie in Fig. 2 dargestellt - in seinem unteren Totpunkt. Der Füllungsvorgang von Brennstoff aus dem Saugraum 10 über die Steuerbohrungen 13 in den Pumpenraum 11 ist abgeschlossen, d. h., dieser ist mit Brennstoff gefüllt. Der Pumpenkolben 12 bewegt sich anschließend wieder in den Pumpenraum 11 hinein, wobei solange kein Druckaufbau im Pumpenraum 11 stattfindet, bis die vordere Steuerkante 14 des Pumpenkolbens 12 die Steuerbohrungen 13 verschlossen haben. Bis zu diesem Zeitpunkt fließt ein Teil des Brennstoffes wieder in den Saugraum 10 ab. Der Schließzylinder 19 des Hauptventiles 18 sowie der Voreinspritzkolben 23 werden währenddessen durch den gemeinsamen Standdruck in den Einspritzleitungen 4 und 6 sowie durch die Federkraft der Druckfedern 20 und 24 in ihrer unteren Endlage gehalten, wobei der Schließzylinder 19 die Hauptbohrung 16 entlang der Dichtschulter 21 gegenüber der Haupteinspritzleitung 4 abdichtet.The mode of operation of the fuel injection device according to the invention is as follows: The pump piston 12 is - as shown in FIG. 2 - at its bottom dead center. The filling process of fuel from the suction chamber 10 via the control bores 13 into the pump chamber 11 is complete, ie it is filled with fuel. The pump piston 12 then moves back into the pump chamber 11, with no pressure building up in the pump chamber 11 until the front control edge 14 of the pump piston 12 has closed the control bores 13. Up to this point, part of the fuel flows back into the suction chamber 10. The locking cylinder 19 of the main valve 18 and the pre-injection piston 23 are meanwhile held in their lower end position by the common stand pressure in the injection lines 4 and 6 and by the spring force of the compression springs 20 and 24, the locking cylinder 19 facing the main bore 16 along the sealing shoulder 21 Main injection line 4 seals.

Etwa zum Zeitpunkt des Verschließens der Steuerbohrungen 13 durch die Steuerkante 14 des Pumpenkolbens 12 wird im Pumpenraum 11 derjenige Förderdruck erreicht, der die den Voreinspritzkolben 23 zuhaltenden Kräfte überwindet.At about the time when the control bores 13 are closed by the control edge 14 of the pump piston 12, that delivery pressure is reached in the pump chamber 11 which overcomes the forces to be held by the pilot injection piston 23.

Der zum Öffnen des Voreinspritzkolbens 23 erforderliche Druck im Pumpenraum wirkt nur auf die vom Dichtungsquerschnitt der Druckleitung 26 gebildete Fläche und muß deshalb größer sein als der Standdruck der Einspritzleitungen 4 und 6, welcherauf die größere Fläche der Dichtschulter 25 wirkt und zusätzlich noch durch die Kraft der Druckfeder 24 unterstützt wird.The pressure in the pump chamber required to open the pre-injection piston 23 only acts on the area formed by the sealing cross-section of the pressure line 26 and must therefore be greater than the standing pressure of the injection lines 4 and 6, which acts on the larger area of the sealing shoulder 25 and additionally by the force of the Compression spring 24 is supported.

Hat sich der Voreinspritzkolben 23 durch diesen ausreichenden Druck im Pumpenraum 11 geringfügig angehoben, dann ist die Dichtung am Dichtdurchmesser der Druckleitung 26 nicht mehr wirksam, und der Pumpenraumdruck wirkt nun schlagartig auf die größere Stirnfläche des Voreinspritzkolbens 23, nachdem dieser von der zweiten Dichtschulter 25 abgehoben hat.If the pre-injection piston 23 has risen slightly as a result of this sufficient pressure in the pump chamber 11, the seal on the sealing diameter of the pressure line 26 is no longer effective, and the pump chamber pressure now acts suddenly on the larger end face of the pre-injection piston 23 after it has been lifted off the second sealing shoulder 25 Has.

Der Voreinspritzkolben 23 springt auf und erzeugt eine Druckwelle, die sich über die Voreinspritzleitung 6 bis zum Voreinspritzventil 7 fortpflanzt. Der Voreinspritzkolben 23 bewegt sich entgegen der Kraft der Druckfeder 24 unter Verdrängung des im Voreinspritzkolbenraum 22 befindlichen Brennstoffes vornehmlich in die Voreinspritzleitung 6 solange, bis dessen ringförmiger Dichtflansch 31 an der Dichtfläche 32 des Einspritzverteilkopfes 3 anliegt. Dadurch wird der Verbindungskanal 27 verschlossen, so daß die Voreinspritzleitung 6 gegenüber der Haupteinspritzleitung 4 abgedichtet ist. Die Brennstoffmenge der Voreinspritzung wird durch den Hub des Voreinspritzkolbens 23 bestimmt.The pre-injection piston 23 jumps up and generates a pressure wave that propagates via the pre-injection line 6 to the pre-injection valve 7. The pre-injection piston 23 moves against the force of the compression spring 24, displacing the fuel located in the pre-injection piston chamber 22, primarily into the pre-injection line 6 until its annular sealing flange 31 bears against the sealing surface 32 of the injection distributor head 3. As a result, the connecting channel 27 is closed, so that the pre-injection line 6 is sealed off from the main injection line 4. The fuel quantity of the pre-injection is determined by the stroke of the pre-injection piston 23.

Die Brennstoffmenge im Pumpenraum 11 besitzt im Zeitpunkt der Voreinspritzung noch keine Abflußmöglichkeit, so daß sich der Druck im Pumpenraum 11 noch weiter aufbaut. Dies geschieht solange, bis der Förderdruck auch die am Schließzylinder 19 anstehenden Gegenkräfte aus Standdruck in der Haupteinspritzleitung 4 und Federkraft der Druckfeder 20 überwindet. Sodann bewegt sich der Schließzylinder 19 nach oben an seinen oberen Anschlag 33 und die Förderung der Haupteinspritzmenge erfolgt aus dem Pumpenraum 11 über die Hauptbohrung 16 und ein Kanalsystem 34 im Inneren des Schließzylinders zur Haupteinspritzleitung 4, von der die Einspritzung über das Haupteinspritzventil 5 erfolgt. Die Haupteinspritzung erfolgt nach Abschluß der Voreinspritzung und Aufwärtsbewegung des Schließzylinders 19 solange, bis die hintere Steuerkante 15 des Pumpenkolbens 12 den Pumpenraum 11 wieder mit der Steuerbohrung 13 verbindet, so daß der verbleibende Kraftstoff wieder in den Saugraum 10 entweicht.The amount of fuel in the pump chamber 11 does not yet have a drain option at the time of the pre-injection, so that the pressure in the pump chamber 11 builds up even further. This continues until the delivery pressure also overcomes the counterforces at the lock cylinder 19 from stand pressure in the main injection line 4 and spring force of the compression spring 20. The lock cylinder 19 then moves upwards to its upper stop 33 and the main injection quantity is delivered from the pump chamber 11 via the main bore 16 and a channel system 34 in the interior of the lock cylinder to the main injection line 4, from which the injection takes place via the main injection valve 5. The main injection takes place after completion of the pre-injection and upward movement of the lock cylinder 19 until the rear control edge 15 of the pump piston 12 connects the pump chamber 11 to the control bore 13 again, so that the remaining fuel escapes into the suction chamber 10 again.

Die Druckdifferenz zwischen dem Pumpenraum 11 und der Haupteinspritzleitung 4 ist durch das antiparallel zum Hauptventil 18 eingebaute Überdruckventil 29 einstellbar. Nach einem gewissen Druckabfall durch die Öffnung der Steuerbohrungen 13 bewegt sich der Schließzylinder 19 nach unten und dichtet die Haupteinspritzleitung 4 gegenüber dem Pumpenraum 11 an der Dichtschulter 21 ab. Bis sich der Standdruck in den Einspritzleitungen 4 und 6 eingestellt hat, ist der Voreinspritzkolben 23 durch die Kraftwirkung der Druckfeder 24 und der Druckdifferenz zwischen den Einspritzleitungen 4 und 6 und dem Pumpenraum 11 in seine untere Endlage zurückgekehrt.The pressure difference between the pump chamber 11 and the main injection line 4 can be set by the pressure relief valve 29 installed antiparallel to the main valve 18. After a certain pressure drop through the opening of the control bores 13, the lock cylinder 19 moves downward and seals the main injection line 4 against the pump chamber 11 on the sealing shoulder 21. Until the stand pressure in the injection lines 4 and 6 has set, the pilot injection piston 23 has returned to its lower end position due to the force of the compression spring 24 and the pressure difference between the injection lines 4 and 6 and the pump chamber 11.

Der Voreinspritzkolbenraum 22 füllt sich mit Brennstoff, der über den Verbindungskanal 27 aus der Haupteinspritzleitung 4 in den Voreinspritzkolbenraum 22 zufließt. Parallel fließt Brennstoff aus der Haupteinspritzleitung 4 bis zum Erreichen des eingestellten Standdruckes am Überdruckventil 29 über die Überdruckbohrung 28 zurück in den Pumpenraum 11. Durchfährt der Pumpenkolben 12 seinen oberen Totpunkt, beginnt der Saughub. Der Pumpenraum 11 füllt sich dabei mit Kraftstoff aus dem Saugraum 10, sofern die Steuerbohrungen 13 nicht gerade vom Pumpenkolben 12 verschlossen sind. Nach Durchfahren des unteren Totpunktes durch den Pumpenkolben 12 ist die Brennstoffeinspritzvorrichtung 1 bereit für einen neuen Einspritzvorgang.The pre-injection piston chamber 22 fills with fuel that flows from the main injection line 4 into the pre-injection piston chamber 22 via the connecting channel 27. In parallel, fuel flows from the main injection line 4 until the set stand pressure at the pressure relief valve 29 is reached via the pressure relief hole 28 back into the pump chamber 11. When the pump piston 12 passes its top dead center, the suction stroke begins. The pump chamber 11 fills with fuel from the suction chamber 10, provided the control bores 13 are not exactly closed by the pump piston 12. After passing through the bottom dead center by the pump piston 12, the fuel injection device 1 is ready for a new injection process.

Claims (8)

  1. Fuel injection device for an internal combustion engine having an injection pump for supplying a main injection amount via a main injection line (4) and having a pre-injection piston chamber (22) which is coupled to a pre-injection line (6) and in which chamber there works a pre-injection piston (23) hydraulically acted on by the injection pump against spring force and having a main valve (18) between the injection pump (2) and the main injection line (4), wherein the geometry and spring force of the pre-injection piston (23) is dimensioned so that the pre-injection amount is supplied before the main valve (18) is opened, characterised in that the main injection line (4) communicates via a communication channel (27) with the pre-injection piston chamber (22), and when pre-injection is ended the pre-injection piston (23) interrupts the communication channel (27) between the main injection line (4) and the pre-injection piston chamber (22).
  2. Fuel injection device according to claim 1, characterised in that a pressure line (26) leads from the pump chamber (11) of the injection pump (2) to the front face of the pre-injection piston (23) on the pump chamber side.
  3. Fuel injection device according to claim 2, characterised in that the front face of the pre-injection piston (23) on the pump chamber side is larger than the effective cross-section of the pressure line (26).
  4. Fuel injection device according to one of the preceding claims, characterised in that the pre-injection line (6) and the main injection line (4) are matched to each other with respect to their length for obtaining a desired spread between the pre- and the main injection.
  5. Fuel injection device according to one of the preceding claims, characterised in that the opening pressures of the pre-injection valve (7) and the main injection valve (5) are matched to each other for obtaining a desired spread between the pre- and the main injection.
  6. Fuel injection device according to claim 1, characterised in that an excess pressure valve (29) is provided antiparallel to the main valve (18).
  7. Fuel injection device according to one of the preceding claims, characterised in that the main valve (18) has a spring-loaded lock cylinder (19) which in its throughflow position blocks the communication channel.
  8. Fuel injection device according to one of the preceding claims, characterised in that the injection pump (2), the main valve (18) and the pre-injection piston chamber (22) form a compact structural unit.
EP90117905A 1989-09-20 1990-09-18 Fuel injection apparatus for an internal combustion engine Expired - Lifetime EP0418800B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3931338A DE3931338A1 (en) 1989-09-20 1989-09-20 FUEL INJECTION DEVICE FOR AN INTERNAL COMBUSTION ENGINE
DE3931338 1989-09-20

Publications (3)

Publication Number Publication Date
EP0418800A2 EP0418800A2 (en) 1991-03-27
EP0418800A3 EP0418800A3 (en) 1991-10-09
EP0418800B1 true EP0418800B1 (en) 1993-10-20

Family

ID=6389782

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90117905A Expired - Lifetime EP0418800B1 (en) 1989-09-20 1990-09-18 Fuel injection apparatus for an internal combustion engine

Country Status (2)

Country Link
EP (1) EP0418800B1 (en)
DE (2) DE3931338A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9302566D0 (en) * 1993-02-10 1993-03-24 Lucas Ind Plc Valve
GB9615663D0 (en) * 1996-07-25 1996-09-04 Lucas Ind Plc Fuel pumping apparatus
US5873527A (en) * 1997-02-19 1999-02-23 Caterpillar Inc. Fuel injector with regulated plunger motion
DE102014002002B4 (en) * 2014-02-17 2016-10-06 L'orange Gmbh Injection system, in particular pump-line nozzle injection system, and injection system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3334619A1 (en) * 1983-09-24 1985-04-11 Robert Bosch Gmbh, 7000 Stuttgart Fuel injection device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3629751C2 (en) * 1986-09-01 1998-07-02 Bosch Gmbh Robert Pre-injection device for internal combustion engines
DE3731240C2 (en) * 1987-09-17 1995-04-06 Volkswagen Ag Injector
DE3732003A1 (en) * 1987-09-23 1989-04-06 Dahlmann Gerd Uwe Injection device
FI80327C (en) * 1988-05-16 1990-05-10 Waertsilae Oy Ab Distribution and control valve for fuel injection pump

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3334619A1 (en) * 1983-09-24 1985-04-11 Robert Bosch Gmbh, 7000 Stuttgart Fuel injection device

Also Published As

Publication number Publication date
DE3931338A1 (en) 1991-03-28
EP0418800A2 (en) 1991-03-27
DE59003143D1 (en) 1993-11-25
EP0418800A3 (en) 1991-10-09

Similar Documents

Publication Publication Date Title
EP0141044B1 (en) Fuel injection device with main and pre-injection for internal-combustion engines
DE3048347C2 (en)
DE2602280A1 (en) HIGH PRESSURE FUEL INJECTION DEVICE FOR DIESEL ENGINES
EP0133470B1 (en) Fuel injection nozzle for internal-combustion engines
DE2755222A1 (en) FUEL INJECTION DEVICE, IN PARTICULAR FOR DIESEL COMBUSTION MACHINES
DE69814990T2 (en) Injector
DE2353737A1 (en) FUEL INJECTION PUMP FOR COMBUSTION MACHINES
EP0688950B1 (en) Fuel injection system
DE19860672A1 (en) Piston pump for high-pressure fuel generation
EP0064146B1 (en) Injection system for injecting two fuels through one injection nozzle
CH669015A5 (en) DEVICE FOR INJECTING INJECTION OF DIESEL OIL AND IGNITION OIL INTO THE COMBUSTION COMPONENT OF A PISTON PISTON ENGINE USED WITH DIESEL OIL OR GAS AS A MAIN FUEL.
DE3712310A1 (en) FUEL INJECTION VALVE USED IN A FUEL INJECTION DEVICE FOR AN INTERNAL COMBUSTION ENGINE
CH671809A5 (en)
DE10139055A1 (en) Method, computer program, control and / or regulating device and fuel system for an internal combustion engine
EP0418800B1 (en) Fuel injection apparatus for an internal combustion engine
DE2656276A1 (en) INJECTION SYSTEM FOR SELF-IGNING COMBUSTION MACHINERY
EP1370764B1 (en) Method for injecting fuel into the combustion chambers of an internal combustion engine, and fuel injection system for said engine
DE1751080B1 (en) Fuel injection nozzle for diesel engines
DE3236828A1 (en) FUEL INJECTION DEVICE
DE3909750C2 (en)
DE2258309A1 (en) FUEL INJECTION PUMP FOR COMBUSTION MACHINES
DE3535005A1 (en) INJECTION DEVICE FOR AN INTERNAL COMBUSTION ENGINE
DE2449332C2 (en) Fuel distributor injection pump for internal combustion engines
DE4425339C2 (en) Injection system
EP0713002B1 (en) High pressure fuel pump for internal combustion engines

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): CH DE FR GB IT LI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): CH DE FR GB IT LI

17P Request for examination filed

Effective date: 19911102

17Q First examination report despatched

Effective date: 19920416

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO MILA

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB IT LI

ET Fr: translation filed
REF Corresponds to:

Ref document number: 59003143

Country of ref document: DE

Date of ref document: 19931125

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19940118

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20020909

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040528

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20060914

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20060921

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20060926

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20060930

Year of fee payment: 17

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20070918

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070930

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080401

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070918

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070918