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EP1458970B1 - Fuel-injection device for an internal combustion engine - Google Patents

Fuel-injection device for an internal combustion engine Download PDF

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Publication number
EP1458970B1
EP1458970B1 EP02796496A EP02796496A EP1458970B1 EP 1458970 B1 EP1458970 B1 EP 1458970B1 EP 02796496 A EP02796496 A EP 02796496A EP 02796496 A EP02796496 A EP 02796496A EP 1458970 B1 EP1458970 B1 EP 1458970B1
Authority
EP
European Patent Office
Prior art keywords
pressure
pressure chamber
control
injection
fuel
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
EP02796496A
Other languages
German (de)
French (fr)
Other versions
EP1458970A1 (en
Inventor
Thomas Kuegler
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch 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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1458970A1 publication Critical patent/EP1458970A1/en
Application granted granted Critical
Publication of EP1458970B1 publication Critical patent/EP1458970B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F02M45/08—Injectors 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
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • 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
    • F02M45/08—Injectors peculiar thereto
    • F02M45/086—Having more than one injection-valve controlling discharge orifices
    • 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
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F02M57/022—Injectors structurally combined with fuel-injection pumps characterised by the pump drive
    • F02M57/023—Injectors structurally combined with fuel-injection pumps characterised by the pump drive mechanical
    • 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
    • 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
    • F02M59/466—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means
    • F02M59/468—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means using piezoelectric operating means
    • 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
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/46—Valves, e.g. injectors, with concentric valve bodies

Definitions

  • the invention relates to a fuel injection device for an internal combustion engine according to the preamble of claim 1.
  • Such a fuel injection device is characterized by the DE 198 35 494 A1 or the US 4976 245A1 known.
  • This fuel injection device has a high-pressure fuel pump and a fuel injection valve connected thereto for each cylinder of the internal combustion engine.
  • the high-pressure fuel pump has a pump piston driven by the internal combustion engine in a lifting movement, which limits a pump working space, which is connected to a pressure chamber of the fuel injection valve.
  • the fuel injection valve has an injection valve member, by which at least one injection opening is controlled and which is acted upon by the pressure prevailing in the pressure chamber against a closing force in an opening direction for releasing the at least one injection opening.
  • a connection of the pump working chamber to a discharge space is controlled at least indirectly to control the fuel injection.
  • the pressure in the pump working chamber and thus in the pressure chamber of the fuel injection valve reaches the opening pressure, so the injection valve member moves in the opening direction and releases the at least one injection port.
  • the injection cross section, which is controlled by the injection valve member thereby is always the same size. This does not allow optimum fuel injection under all operating conditions of the internal combustion engine.
  • the fuel injection device according to the invention with the features of claim 1 has the advantage that can be released or closed by the second injection valve member with the at least one second injection port additional injection cross section, so that the injection cross section can be optimally adapted to the operating conditions of the internal combustion engine.
  • the control of the injection cross section is carried out in a simple manner by the variable pressure in the control pressure chamber.
  • the embodiment according to claim 5 allows a substantial pressure equalization at the control valve member.
  • the embodiment of claim 8 allows easy generation of the pressure in the control pressure chamber.
  • the embodiment according to claim 11 enables an optimal adaptation of the injection cross section to the load and / or speed of the internal combustion engine.
  • the embodiment according to claim 12 allows combustion with low noise and pollutant emission of the internal combustion engine.
  • FIG. 1 a fuel injection device for an internal combustion engine in a schematic representation in a longitudinal section
  • FIG. 2 in an enlarged view a in FIG. 1 II section of the fuel injection device
  • FIG. 3 in an enlarged view a in FIG. 1 labeled III section of the fuel injector
  • FIG. 4 Strokes of injection valve members of the fuel injector over time during an injection cycle.
  • the internal combustion engine is preferably a self-igniting internal combustion engine.
  • the fuel injection device is designed as a so-called pump-nozzle system or as a pump-line-nozzle system and has for each cylinder of the internal combustion engine in each case a high-pressure fuel pump 10 and connected thereto fuel injection valve 12.
  • the high-pressure fuel pump 10 is disposed away from the fuel injection valve 12 and connected thereto via a line.
  • the fuel injector is formed as a pump-nozzle system, wherein the high-pressure fuel pump 10 and the fuel injection valve 12 are directly connected to each other and form a structural unit.
  • the high-pressure fuel pump 10 has a tightly guided in a cylinder bore 16 in a pump body 14
  • Pump piston 18 which is driven by a cam 20 of a camshaft of the internal combustion engine against the force of a return spring 19 in a lifting movement.
  • the pump piston 18 defines in the cylinder 16 a pump working chamber 22 in which the delivery stroke of the pump piston 18 compresses fuel under high pressure.
  • the pump working chamber 22 is supplied with fuel from a fuel tank 24 of the motor vehicle during the suction stroke of the pump piston 18 in a manner not shown.
  • the fuel injection valve 12 has, as in the FIGS. 1 and 3 illustrate a valve body 26 which may be formed in several parts, in which a first injection valve member 28 is guided longitudinally displaceably in a bore 30.
  • the valve body 26 at its the combustion chamber of the cylinder of the internal combustion engine end portion facing at least a first, preferably a plurality of first injection ports 32 which are arranged distributed over the circumference of the valve body 26.
  • the first injection valve member 28 has, at its end region facing the combustion chamber, an approximately conical sealing surface 34, for example, which cooperates with a valve seat 36 formed in the valve body 26 in its end region facing the combustion chamber, from or after which the first injection openings 32 are discharged.
  • annular space 38 is present between the injection valve member 28 and the bore 30 toward the valve seat 36, which merges in its end region remote from the valve seat 36 by a radial widening of the bore 30 into a pressure chamber 40 surrounding the first injection valve member 28.
  • the first injection valve member 28 has at the level of the pressure chamber 40 by a cross-sectional reduction on a pressure shoulder 42.
  • a first biased closing spring 44 At the end remote from the combustion chamber of the first injection valve member 28 engages a first biased closing spring 44, through which the first Injection valve member 28 is pressed to the valve seat 36 back.
  • the first closing spring 44 is arranged in a spring chamber 46 of the valve body 26, which adjoins the bore 30.
  • the first injection valve member 28 of the fuel injection valve 12 is hollow and in this a second injection valve member 128 is slidably guided in a bore formed coaxially in the injection valve member 28.
  • a second injection valve member 128 is slidably guided in a bore formed coaxially in the injection valve member 28.
  • the second injection valve member 128, at least one second injection port 132 in the valve body 26 is controlled.
  • the at least one second injection opening 132 is arranged offset in the direction of the longitudinal axis of the injection valve members 28, 128 to the at least one first injection opening 32 toward the combustion chamber.
  • the second injection valve member 128 has, at its end region facing the combustion chamber, an approximately conical sealing surface 134, for example, which cooperates with a valve seat 136 formed in the valve body 26 in its end region facing the combustion chamber, from or after which the second injection openings 132 are discharged.
  • the second injection valve member 128 may be formed in two parts and having a sealing surface 134, the combustion chamber facing part and a combustion chamber adjacent to the first part second part. Near the combustion chamber end of the second injection valve member 128, a pressure surface 142 is formed on this, acts on the pressure prevailing in the pressure chamber 40 when the first injection valve member 28 is open.
  • a control pressure chamber 60 is formed in which a second, acting on the second injection valve member 128 closing spring 144 is arranged.
  • the control pressure chamber 60 is slightly smaller in diameter than the spring chamber 46.
  • the first Injection valve member 28 protrudes with its end into the spring chamber 46 and is supported on the first closing spring 44.
  • the first closing spring 44 is supported with its end remote from the first injection valve member 28 at a sleeve 47 arranged between the spring chamber 46 and the control pressure chamber 60.
  • the sleeve 47 in turn is supported on an annular shoulder formed at the transition from the spring chamber 46 to the control pressure chamber 60 by the diameter reduction.
  • the sleeve 47 may be pressed into the spring chamber 46 and thus fixed or may alternatively be displaceable in the spring chamber 46 in the direction of the longitudinal axis of the first injection valve member 28.
  • the second injection valve member 128 protrudes through the sleeve 47 into the control pressure chamber 60 and is supported on a control piston 62 delimiting the control pressure chamber 60 toward the spring chamber 46.
  • the second closing spring 144 is supported with its end facing away from the control piston 62 at the bottom of the control pressure chamber 60.
  • the control pressure chamber 60 is supplied under pressure fuel, for example by means of a feed pump 64.
  • the feed pump 64 may also serve to promote during the suction stroke of the pump piston 18 fuel into the pump working chamber 22.
  • the pressure in the control pressure chamber 60 is variably set depending on operating conditions of the internal combustion engine, such as engine speed, load, temperature and others.
  • the feed pump 64 can be operated correspondingly with variable speed or it can be provided between the feed pump 64 and the control pressure chamber 60, a relief valve 66, by means of which the pressure in the control pressure chamber 60 is controlled by the relief valve 66 opens or closes a connection to a low pressure region ,
  • connection 48 in the pressure chamber 40 of the fuel injection valve 12.
  • the connection 48 is controlled by a control valve 70.
  • the control valve 70 has a in a subsequent to the control pressure chamber 60 bore 71 of the valve body 26 tightly guided piston-shaped control valve member 72.
  • the bore 71 has a formed by a radial extension, the control valve member 72 surrounding annular space 73 into which a leading to the pump working chamber 22 part of the connection 48 and a pressure chamber 40 leading part of the connection 48 opens.
  • a valve seat 74 is formed, with which the control valve member 72 cooperates with a sealing surface 76 formed on this.
  • the starting from the annular space 73 to the control pressure chamber 60 arranged portion 171 of the bore 71 has a slightly smaller diameter than the starting from the annular space 73 the control pressure chamber 60 facing away arranged portion 271 of the bore 71.
  • the control valve member 72 has accordingly in his in section 171 of the bore 71 guided portion 172 has a smaller diameter than in its guided in the section 271 of the bore 71 portion 272.
  • the sealing surface 76 is formed on the control valve member 72 at the junction between the two regions 172 and 272.
  • the control valve member 72 has a greatly reduced diameter portion 372 so that between the portion 372 of the control valve member 72 and the portion 171 of the bore 71, an annular space 77th is available.
  • the annular space 77 has a connection to a low-pressure region, which may be, for example, a return 78 into the fuel reservoir 24.
  • the spring chamber 46 is also connected to the return 78.
  • an actuator pressure chamber 80 is formed in the valve body 26 or the pump body 14 or between them, which is limited by the control valve member 72.
  • the control valve member 72 is thus acted upon by the pressure prevailing in the actuator pressure chamber 80 in the closing direction.
  • the control valve member 72 is of the pressure prevailing in the control pressure chamber 60 and also by a clamped between the control piston 62 and the control valve member 72 return spring 82.
  • the pressure in Aktordruckraum 80 is controlled by a piezoelectric actuator 84 which depends on an applied to this Voltage its extent, in particular changes its length and thereby changes the pressure in the actuator pressure chamber 80.
  • the actuator 84 is connected to an electronic control device 86 through which the voltage applied to the actuator 84 is provided.
  • the actuator 84 may be connected via a hydraulic coupler to the actuator pressure chamber 80 in order to reinforce a relatively small change in length of the actuator 84 and to be able to effect relatively large pressure changes in the actuator pressure chamber 80. If a high pressure prevails in the actuator pressure chamber 80, then the control valve member 72 is against the pressure prevailing in the control pressure chamber 60 and against the force of the return spring 82 in its closed position, so that the pump working chamber 22 is separated from the return line 78.
  • control valve member 72 If there is a slight pressure in the actuator pressure chamber 80, then the control valve member 72 is in its open position by the pressure prevailing in the control pressure chamber 60 and the return spring 82, so that the pump working chamber 22 is connected to the return line 78.
  • control device 86 and the feed pump 64 and the relief valve 66 is controlled to adjust the pressure prevailing in the control pressure chamber 60 pressure depending on operating conditions of the internal combustion engine.
  • a connection 88 is provided between the actuator pressure chamber 80 and the control pressure chamber 60, in which a check valve 90 which opens toward the actuator pressure chamber 80 is arranged.
  • the check valve 90 opens, so that the actuator pressure chamber 80 can be filled with fuel. If the pressure in the actuator pressure chamber 80 is higher than in the control pressure chamber 60, so the check valve 90 closes, so that the Aktordruckraum 80 is separated from the control pressure chamber 60.
  • the control valve member 72 When the suction stroke of the pump piston 18, the control valve member 72 is in its open position, wherein the annular space 77 has a connection with the feed pump 64, so that fuel from the fuel tank 24 passes into the pump working chamber 22.
  • the start of fuel injection is determined by moving the control valve member 72 to its closed position.
  • an increased voltage is applied to the actuator 84 by the control device 86, so that the pressure in the actuator pressure chamber 80 is increased and the control valve member 72 in its closed position arrives.
  • the pump working chamber 22 is then separated from the return line 78 and in this high pressure builds up according to the stroke of the pump piston 18.
  • the fuel injection valve 12 opens by the first injection valve member 28 lifts off with its sealing surface 34 from the valve seat 36 and the at least one first injection port 32 releases.
  • the closing force exerted by the pressure prevailing in the control pressure chamber 60, the second closing spring 144 and the return spring 82 on the control piston 62 and thus the second injection valve member 128 is greater than the pressure prevailing in the pressure chamber 40 Force exerted on the second injection valve member 128 via the pressure surface 142 so that the second injection valve member 128 remains in its closed position.
  • the fuel injection valve 12 therefore, only part of the total injection cross section is opened with the first injection openings 32, so that correspondingly only a small amount of fuel is injected.
  • the end of the fuel injection is determined by the control device 86, the voltage at the actuator 84 is reduced, whereby the pressure in the Aktordruckraum 80 is reduced, so that the control valve member 72 caused by the pressure prevailing in the control pressure chamber 60 and the force of the return spring 82nd moved to its open position.
  • the pump chamber 22 is then connected to the return line 78 and in this no high pressure can build up.
  • the first injection valve member 28 then closes due to the force of the first closing spring 44.
  • pressure surface 142 of the second injection valve member 128 is separated from the pressure chamber 40, so that the second injection valve member 128 due to Force of the second closing spring 144 closes.
  • a stroke stop for the second injection valve member 128 is arranged on the first injection valve member 28, through which the opening stroke of the second injection valve member 128 is limited.
  • the second injection valve member 128 may also open until it comes to rest on the stroke stop.
  • the first injection valve member 28 closes, the second injection valve member 128 is forcibly also closed via this stroke stop.
  • the injection cross sections formed by the first injection openings 32 and the second injection openings 132 are at least approximately equal, so that when opening only the first injection valve member 28 of half total Injection cross section is released.
  • the first injection openings 32 form a larger or smaller injection cross section than the second injection openings 132.
  • FIG. 4 the course of the opening stroke h for the first injection valve member 28 is shown in solid line and for the second injection valve member 128 in dashed line during an injection cycle over the time t.
  • the control valve member 72 is brought by setting a high pressure in the actuator pressure chamber 80 in its closed position, so that the pump working chamber 22 is separated from the return line 78.
  • a high pressure is set, so that at low delivery stroke of the pump piston 18 initially only the first injection valve member 28 opens and the fuel injection valve 12, only a portion of the entire injection cross section is released. There is then a pre-injection of a small amount of fuel only through the first injection ports 32.
  • the voltage at the actuator 84 is then reduced, so that the pressure in the actuator pressure chamber 80 decreases and the control valve member 72 assumes its open position, so that the pump working chamber 22 relieved is and the first injection valve member 28 closes and the fuel injection is interrupted. Subsequently, the voltage at the actuator 84 is increased by the control device 86, so that the control valve member 72 again assumes its closed position due to the increased pressure in the actuator pressure chamber 80.
  • the pressure in the control pressure chamber 60 can be reduced by the control device 86 so that the closing force is reduced to the second injection valve member 128 and in addition, the second injection valve member 128 opens, so that Fuel injection valve 12, the entire injection cross section is released and a main injection of a large amount of fuel takes place.
  • the pressure in the control pressure chamber 60 can be reduced by the control device 86 already at the beginning of the main injection, so that the second injection valve member 128 only after a short time delay after the first injection valve member 28 opens.
  • the pressure in the control pressure chamber 60 can also be opened by the control device 86 during the course of the main injection, so that the second injection valve member 128 opens with a larger time delay after the first injection valve member 28 as in FIG. 4 is shown. There is then a main injection of a large amount of fuel through the first injection ports 32 and the second injection ports 132nd
  • a high pressure is set, so that only the first injection valve member 28 opens and the second injection valve member 128 remains closed.
  • a high pressure can be set, so that only the first injection valve member 28 opens, and during the main injection, the pressure be reduced in the control pressure chamber 60 by the control device 86, so that in addition, the second injection valve member 128 opens.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine nach der Gattung des Anspruchs 1.The invention relates to a fuel injection device for an internal combustion engine according to the preamble of claim 1.

Eine solche Kraftstoffeinspritzeinrichtung ist durch die DE 198 35 494 A1 oder die US 4976 245A1 bekannt. Diese Kraftstoffeinspritzeinrichtung weist für jeden Zylinder der Brennkraftmaschine eine Kraftstoffhochdruckpumpe und ein mit dieser verbundenes Kraftstoffeinspritzventil auf. Die Kraftstoffhochdruckpumpe weist einen durch die Brennkraftmaschine in einer Hubbewegung angetriebenen Pumpenkolben auf, der einen Pumpenarbeitsraum begrenzt, der mit einem Druckraum des Kraftstoffeinspritzventils verbunden ist. Das Kraftstoffeinspritzventil weist ein Einspritzventilglied auf, durch das wenigstens eine Einspritzöffnung gesteuert wird und das von dem im Druckraum herrschenden Druck beaufschlagt gegen eine Schließkraft in einer Öffnungsrichtung zur Freigabe der wenigstens einen Einspritzöffnung bewegbar ist. Durch ein mittels eines piezoelektrischen Aktors betätigtes Steuerventil wird zur Steuerung der Kraftstoffeinspritzung zumindest mittelbar eine Verbindung des Pumpenarbeitsraums mit einem Entlastungsraum gesteuert. Wenn der Druck im Pumpenarbeitsraum und damit im Druckraum des Kraftstoffeinspritzventils den Öffnungsdruck erreicht, so bewegt sich das Einspritzventilglied in Öffnungsrichtung und gibt die wenigstens eine Einspritzöffnung frei. Der Einspritzquerschnitt, der durch das Einspritzventilglied dabei gesteuert wird ist immer gleich groß. Dies ermöglicht nicht unter allen Betriebsbedingungen der Brennkraftmaschine eine optimale Kraftstoffeinspritzung.Such a fuel injection device is characterized by the DE 198 35 494 A1 or the US 4976 245A1 known. This fuel injection device has a high-pressure fuel pump and a fuel injection valve connected thereto for each cylinder of the internal combustion engine. The high-pressure fuel pump has a pump piston driven by the internal combustion engine in a lifting movement, which limits a pump working space, which is connected to a pressure chamber of the fuel injection valve. The fuel injection valve has an injection valve member, by which at least one injection opening is controlled and which is acted upon by the pressure prevailing in the pressure chamber against a closing force in an opening direction for releasing the at least one injection opening. By means of a control valve operated by means of a piezoelectric actuator, a connection of the pump working chamber to a discharge space is controlled at least indirectly to control the fuel injection. When the pressure in the pump working chamber and thus in the pressure chamber of the fuel injection valve reaches the opening pressure, so the injection valve member moves in the opening direction and releases the at least one injection port. The injection cross section, which is controlled by the injection valve member thereby is always the same size. This does not allow optimum fuel injection under all operating conditions of the internal combustion engine.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Kraftstoffeinspritzeinrichtung mit den Merkmalen gemäß Anspruch 1 hat demgegenüber den Vorteil, daß durch das zweite Einspritzventilglied mit der wenigstens einen zweiten Einspritzöffnung zusätzlicher Einspritzquerschnitt freigegeben oder verschlossen werden kann, so daß der Einspritzquerschnitt an die Betriebsbedingungen der Brennkraftmaschine optimal angepasst werden kann. Die Steuerung des Einspritzquerschnitts erfolgt dabei in einfacher Weise durch den variablen Druck im Steuerdruckraum.The fuel injection device according to the invention with the features of claim 1 has the advantage that can be released or closed by the second injection valve member with the at least one second injection port additional injection cross section, so that the injection cross section can be optimally adapted to the operating conditions of the internal combustion engine. The control of the injection cross section is carried out in a simple manner by the variable pressure in the control pressure chamber.

In den abhängigen Ansprüchen sind vorteilhafte Ausgestaltungen und Weiterbildungen der erfindungsgemäßen Kraftstoffeinspritzeinrichtung angegeben. Die Ausbildung gemäß Anspruch 5 ermöglicht einen weitgehenden Druckausgleich am Steuerventilglied. Die Ausbildung gemäß Anspruch 8 ermöglicht eine einfache Erzeugung des Drucks im Steuerdruckraum. Die Ausbildung gemäß Anspruch 11 ermöglicht eine optimale Anpassung des Einspritzquerschnitts an die Last und/oder Drehzahl der Brennkraftmaschine. Die Ausbildung gemäß Anspruch 12 ermöglicht eine Verbrennung mit geringer Geräusch- und Schadstoffemission der Brennkraftmaschine.In the dependent claims advantageous refinements and developments of the fuel injection device according to the invention are given. The embodiment according to claim 5 allows a substantial pressure equalization at the control valve member. The embodiment of claim 8 allows easy generation of the pressure in the control pressure chamber. The embodiment according to claim 11 enables an optimal adaptation of the injection cross section to the load and / or speed of the internal combustion engine. The embodiment according to claim 12 allows combustion with low noise and pollutant emission of the internal combustion engine.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eine Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine in schematischer Darstellung in einem Längsschnitt, Figur 2 in vergrößerter Darstellung einen in Figur 1 mit II bezeichneten Ausschnitt der Kraftstoffeinspritzeinrichtung, Figur 3 in vergrößerter Darstellung einen in Figur 1 mit III bezeichneten Ausschnitt der Kraftstoffeinspritzeinrichtung und Figur 4 Hubverläufe von Einspritzventilgliedern der Kraftstoffeinspritzeinrichtung über der Zeit während einem Einspritzzyklus.An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description. Show it FIG. 1 a fuel injection device for an internal combustion engine in a schematic representation in a longitudinal section, FIG. 2 in an enlarged view a in FIG. 1 II section of the fuel injection device, FIG. 3 in an enlarged view a in FIG. 1 labeled III section of the fuel injector and FIG. 4 Strokes of injection valve members of the fuel injector over time during an injection cycle.

Beschreibung des AusführungsbeispielsDescription of the embodiment

In den Figuren 1 bis 3 ist eine Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine eines Kraftfahrzeugs dargestellt. Die Brennkraftmaschine ist vorzugsweise eine selbstzündende Brennkraftmaschine. Die Kraftstoffeinspritzeinrichtung ist als sogenanntes Pumpe-Düse-System oder als Pumpe-Leitung-Düse-System ausgebildet und weist für jeden Zylinder der Brennkraftmaschine jeweils eine Kraftstoffhochdruckpumpe 10 und ein mit dieser verbundenes Kraftstoffeinspritzventil 12 auf. Bei einer Ausbildung als Pumpe-Leitung-Düse-System ist die Kraftstoffhochdruckpumpe 10 entfernt vom Kraftstoffeinspritzventil 12 angeordnet und mit diesem über eine Leitung verbunden. Bei dem dargestellten Ausführungsbeispiel ist die Kraftstoffeinspritzeinrichtung als Pumpe-Düse-System ausgebildet, wobei die Kraftstoffhochdruckpumpe 10 und das Kraftstoffeinspritzventil 12 direkt miteinander verbunden sind und eine Baueinheit bilden. Die Kraftstoffhochdruckpumpe 10 weist einen in einer Zylinderbohrung 16 in einem Pumpenkörper 14 dicht geführten Pumpenkolben 18 auf, der durch einen Nocken 20 einer Nockenwelle der Brennkraftmaschine entgegen der Kraft einer Rückstellfeder 19 in einer Hubbewegung angetrieben wird. Der Pumpenkolben 18 begrenzt im Zylinder 16 einen Pumpenarbeitsraum 22, in dem beim Förderhub des Pumpenkolbens 18 Kraftstoff unter Hochdruck verdichtet wird. Dem Pumpenarbeitsraum 22 wird beim Saughub des Pumpenkolbens 18 in nicht näher dargestellter Weise Kraftstoff aus einem Kraftstoffvorratsbehälter 24 des Kraftfahrzeugs zugeführt.In the FIGS. 1 to 3 a fuel injection device for an internal combustion engine of a motor vehicle is shown. The internal combustion engine is preferably a self-igniting internal combustion engine. The fuel injection device is designed as a so-called pump-nozzle system or as a pump-line-nozzle system and has for each cylinder of the internal combustion engine in each case a high-pressure fuel pump 10 and connected thereto fuel injection valve 12. In a design as a pump-line-nozzle system, the high-pressure fuel pump 10 is disposed away from the fuel injection valve 12 and connected thereto via a line. In the illustrated embodiment, the fuel injector is formed as a pump-nozzle system, wherein the high-pressure fuel pump 10 and the fuel injection valve 12 are directly connected to each other and form a structural unit. The high-pressure fuel pump 10 has a tightly guided in a cylinder bore 16 in a pump body 14 Pump piston 18 which is driven by a cam 20 of a camshaft of the internal combustion engine against the force of a return spring 19 in a lifting movement. The pump piston 18 defines in the cylinder 16 a pump working chamber 22 in which the delivery stroke of the pump piston 18 compresses fuel under high pressure. The pump working chamber 22 is supplied with fuel from a fuel tank 24 of the motor vehicle during the suction stroke of the pump piston 18 in a manner not shown.

Das Kraftstoffeinspritzventil 12 weist wie in den Figuren 1 und 3 dargestellt einen Ventilkörper 26 auf, der mehrteilig ausgebildet sein kann, in dem ein erstes Einspritzventilglied 28 in einer Bohrung 30 längsverschiebbar geführt ist. Wie in Figur 2 dargestellt weist der Ventilkörper 26 an seinem dem Brennraum des Zylinders der Brennkraftmaschine zugewandten Endbereich wenigstens eine erste, vorzugsweise mehrere erste Einspritzöffnungen 32 auf, die über den Umfang des Ventilkörpers 26 verteilt angeordnet sind. Das erste Einspritzventilglied 28 weist an seinem dem Brennraum zugewandten Endbereich eine beispielsweise etwa kegelförmige Dichtfläche 34 auf, die mit einem im Ventilkörper 26 in dessen dem Brennraum zugewandtem Endbereich ausgebildeten Ventilsitz 36 zusammenwirkt, von dem oder nach dem die ersten Einspritzöffnungen 32 abführen. Im Ventilkörper 26 ist zwischen dem Einspritzventilglied 28 und der Bohrung 30 zum Ventilsitz 36 hin ein Ringraum 38 vorhanden, der in seinem dem Ventilsitz 36 abgewandten Endbereich durch eine radiale Erweiterung der Bohrung 30 in einen das erste Einspritzventilglied 28 umgebenden Druckraum 40 übergeht. Das erste Einspritzventilglied 28 weist auf Höhe des Druckraums 40 durch eine Querschnittsverringerung eine Druckschulter 42 auf. Am dem Brennraum abgewandten Ende des ersten Einspritzventilglieds 28 greift eine erste vorgespannte Schließfeder 44 an, durch die das erste Einspritzventilglied 28 zum Ventilsitz 36 hin gedrückt wird. Die erste Schließfeder 44 ist in einem Federraum 46 des Ventilkörpers 26 angeordnet, der sich an die Bohrung 30 anschließt.The fuel injection valve 12 has, as in the FIGS. 1 and 3 illustrate a valve body 26 which may be formed in several parts, in which a first injection valve member 28 is guided longitudinally displaceably in a bore 30. As in FIG. 2 illustrated, the valve body 26 at its the combustion chamber of the cylinder of the internal combustion engine end portion facing at least a first, preferably a plurality of first injection ports 32 which are arranged distributed over the circumference of the valve body 26. The first injection valve member 28 has, at its end region facing the combustion chamber, an approximately conical sealing surface 34, for example, which cooperates with a valve seat 36 formed in the valve body 26 in its end region facing the combustion chamber, from or after which the first injection openings 32 are discharged. In the valve body 26, an annular space 38 is present between the injection valve member 28 and the bore 30 toward the valve seat 36, which merges in its end region remote from the valve seat 36 by a radial widening of the bore 30 into a pressure chamber 40 surrounding the first injection valve member 28. The first injection valve member 28 has at the level of the pressure chamber 40 by a cross-sectional reduction on a pressure shoulder 42. At the end remote from the combustion chamber of the first injection valve member 28 engages a first biased closing spring 44, through which the first Injection valve member 28 is pressed to the valve seat 36 back. The first closing spring 44 is arranged in a spring chamber 46 of the valve body 26, which adjoins the bore 30.

Das erste Einspritzventilglied 28 des Kraftstoffeinspritzventils 12 ist hohl ausgebildet und in diesem ist in einer koaxial im Einspritzventilglied 28 ausgebildeten Bohrung ein zweites Einspritzventilglied 128 verschiebbar geführt. Durch das zweite Einspritzventilglied 128 wird wenigstens eine zweite Einspritzöffnung 132 im Ventilkörper 26 gesteuert. Die wenigstens eine zweite Einspritzöffnung 132 ist in Richtung der Längsachse der Einspritzventilglieder 28,128 zu der wenigstens einen ersten Einspritzöffnung 32 zum Brennraum hin versetzt angeordnet. Das zweite Einspritzventilglied 128 weist an seinem dem Brennraum zugewandten Endbereich eine beispielsweise etwa kegelförmige Dichtfläche 134 auf, die mit einem im Ventilkörper 26 in dessen dem Brennraum zugewandtem Endbereich ausgebildeten Ventilsitz 136 zusammenwirkt, von dem oder nach dem die zweiten Einspritzöffnungen 132 abführen. Das zweite Einspritzventilglied 128 kann zweiteilig ausgebildet sein und einen die Dichtfläche 134 aufweisenden, dem Brennraum zugewandten Teil und einen vom Brennraum weg an den ersten Teil anschließenden zweiten Teil aufweisen. Nahe dem brennraumseitigen Ende des zweiten Einspritzventilglieds 128 ist an diesem eine Druckfläche 142 gebildet, auf die bei geöffnetem erstem Einspritzventilglied 28 der im Druckraum 40 herrschende Druck wirkt.The first injection valve member 28 of the fuel injection valve 12 is hollow and in this a second injection valve member 128 is slidably guided in a bore formed coaxially in the injection valve member 28. By the second injection valve member 128, at least one second injection port 132 in the valve body 26 is controlled. The at least one second injection opening 132 is arranged offset in the direction of the longitudinal axis of the injection valve members 28, 128 to the at least one first injection opening 32 toward the combustion chamber. The second injection valve member 128 has, at its end region facing the combustion chamber, an approximately conical sealing surface 134, for example, which cooperates with a valve seat 136 formed in the valve body 26 in its end region facing the combustion chamber, from or after which the second injection openings 132 are discharged. The second injection valve member 128 may be formed in two parts and having a sealing surface 134, the combustion chamber facing part and a combustion chamber adjacent to the first part second part. Near the combustion chamber end of the second injection valve member 128, a pressure surface 142 is formed on this, acts on the pressure prevailing in the pressure chamber 40 when the first injection valve member 28 is open.

An den Federraum 46 vom Brennraum weg anschließend ist wie in den Figuren 1 und 2 dargestellt im Ventilkörper 26 ein Steuerdruckraum 60 ausgebildet, in dem eine zweite, auf das zweite Einspritzventilglied 128 wirkende Schließfeder 144 angeordnet ist. Der Steuerdruckraum 60 ist im Durchmesser etwas kleiner ausgebildet als der Federraum 46. Das erste Einspritzventilglied 28 ragt mit seinem Ende in den Federraum 46 hinein und stützt sich an der ersten Schließfeder 44 ab. Die erste Schließfeder 44 stützt sich mit ihrem dem ersten Einspritzventilglied 28 abgewandten Ende an einer zwischen dem Federraum 46 und dem Steuerdruckraum 60 angeordneten Hülse 47 ab. Die Hülse 47 stützt sich wiederum an einer am Übergang vom Federraum 46 zum Steuerdruckraum 60 durch die Durchmesserverringerung gebildeten Ringschulter ab. Die Hülse 47 kann in den Federraum 46 eingepresst und somit fixiert sein oder kann alternativ im Federraum 46 in Richtung der Längsachse des ersten Einspritzventilglieds 28 verschiebbar sein. Das zweite Einspritzventilglied 128 ragt durch die Hülse 47 hindurch in den Steuerdruckraum 60 und stützt sich an einem den Steuerdruckraum 60 zum Federraum 46 hin begrenzenden Steuerkolben 62 ab. Auf der den Steuerdruckraum 146 begrenzenden Seite des Steuerkolbens 62 stützt sich die zweite Schließfeder 144 ab. Die zweite Schließfeder 144 stützt sich mit ihrem dem Steuerkolben 62 abgewandten Ende am Boden des Steuerdruckraums 60 ab.To the spring chamber 46 away from the combustion chamber is then as in the FIGS. 1 and 2 represented in the valve body 26, a control pressure chamber 60 is formed in which a second, acting on the second injection valve member 128 closing spring 144 is arranged. The control pressure chamber 60 is slightly smaller in diameter than the spring chamber 46. The first Injection valve member 28 protrudes with its end into the spring chamber 46 and is supported on the first closing spring 44. The first closing spring 44 is supported with its end remote from the first injection valve member 28 at a sleeve 47 arranged between the spring chamber 46 and the control pressure chamber 60. The sleeve 47 in turn is supported on an annular shoulder formed at the transition from the spring chamber 46 to the control pressure chamber 60 by the diameter reduction. The sleeve 47 may be pressed into the spring chamber 46 and thus fixed or may alternatively be displaceable in the spring chamber 46 in the direction of the longitudinal axis of the first injection valve member 28. The second injection valve member 128 protrudes through the sleeve 47 into the control pressure chamber 60 and is supported on a control piston 62 delimiting the control pressure chamber 60 toward the spring chamber 46. On the control pressure chamber 146 limiting side of the control piston 62, the second closing spring 144 is supported. The second closing spring 144 is supported with its end facing away from the control piston 62 at the bottom of the control pressure chamber 60.

Dem Steuerdruckraum 60 wird unter Druck stehender Kraftstoff zugeführt, beispielsweise mittels einer Förderpumpe 64. Die Förderpumpe 64 kann außerdem dazu dienen, beim Saughub des Pumpenkolbens 18 Kraftstoff in den Pumpenarbeitsraum 22 zu fördern. Der Druck im Steuerdruckraum 60 wird in Abhängigkeit von Betriebsbedingungen der Brennkraftmaschine, wie beispielsweise Drehzahl, Last, Temperatur und anderen, variabel eingestellt. Hierzu kann die Förderpumpe 64 entsprechend mit variabler Drehzahl betrieben werden oder es kann zwischen der Förderpumpe 64 und dem Steuerdruckraum 60 ein Entlastungsventil 66 vorgesehen sein, mittels dem der Druck im Steuerdruckraum 60 gesteuert wird, indem das Entlastungsventil 66 eine Verbindung zu einem Niederdruckbereich öffnet oder schließt.The control pressure chamber 60 is supplied under pressure fuel, for example by means of a feed pump 64. The feed pump 64 may also serve to promote during the suction stroke of the pump piston 18 fuel into the pump working chamber 22. The pressure in the control pressure chamber 60 is variably set depending on operating conditions of the internal combustion engine, such as engine speed, load, temperature and others. For this purpose, the feed pump 64 can be operated correspondingly with variable speed or it can be provided between the feed pump 64 and the control pressure chamber 60, a relief valve 66, by means of which the pressure in the control pressure chamber 60 is controlled by the relief valve 66 opens or closes a connection to a low pressure region ,

Vom Pumpenarbeitsraum 22 führt durch den Pumpenkörper 14 und, den Ventilkörper 26 eine Verbindung 48 in den Druckraum 40 des Kraftstoffeinspritzventils 12. Die Verbindung 48 wird durch ein Steuerventil 70 gesteuert. Das Steuerventil 70 weist ein in einer an den Steuerdruckraum 60 anschließenden Bohrung 71 des Ventilkörpers 26 dicht geführtes kolbenförmiges Steuerventilglied 72 auf. Die Bohrung 71 weist einen durch eine radiale Erweiterung gebildeten, das Steuerventilglied 72 umgebenden Ringraum 73 auf, in den ein zum Pumpenarbeitsraum 22 führender Teil der Verbindung 48 und ein zum Druckraum 40 führender Teil der Verbindung 48 mündet. An dem zum Steuerdruckraum 60 weisenden Übergang vom Ringraum 73 zur Bohrung 71 ist ein Ventilsitz 74 ausgebildet, mit dem das Steuerventilglied 72 mit einer an diesem ausgebildeten Dichtfläche 76 zusammenwirkt. Der ausgehend vom Ringraum 73 zum Steuerdruckraum 60 hin angeordneten Abschnitt 171 der Bohrung 71 weist einen etwas kleineren Durchmesser auf als der ausgehend vom Ringraum 73 dem Steuerdruckraum 60 abgewandt angeordnete Abschnitt 271 der Bohrung 71. Das Steuerventilglied 72 weist entsprechend in seinem im Abschnitt 171 der Bohrung 71 geführten Bereich 172 einen kleineren Durchmesser auf als in seinem im Abschnitt 271 der Bohrung 71 geführten Bereich 272. Die Dichtfläche 76 ist am Steuerventilglied 72 am Übergang zwischen den beiden Bereichen 172 und 272 ausgebildet. Zwischen der Dichtfläche 76 und dem im Abschnitt 171 der Bohrung 71 geführten Bereich 172 des Steuerventilglieds 72 weist das Steuerventilglied 72 einen im Durchmesser stark verringerten Bereich 372 auf, so daß zwischen dem Bereich 372 des Steuerventilglieds 72 und dem Abschnitt 171 der Bohrung 71 ein Ringraum 77 vorhanden ist. Der Ringraum 77 weist eine Verbindung mit einem Niederdruckbereich auf, der beispielsweise ein Rücklauf 78 in den Kraftstoffvorratsbehälter 24 sein kann. Der Federraum 46 ist ebenfalls mit dem Rücklauf 78 verbunden. Wenn sich das Steuerventilglied 72 in seiner Schließstellung befindet, in der es mit seiner Dichtfläche 76 am Ventilsitz 74 anliegt, so ist der Ringraum 73 vom Ringraum 77 getrennt und der Pumpenarbeitsraum 22 ist vom Rücklauf 78 getrennt, so daß sich im Pumpenarbeitsraum 22 entsprechend dem Hub des Pumpenkolbens 18 Druck aufbauen kann. Wenn sich das Steuerventilglied 72 in einer Öffnungsstellung befindet, in der dieses mit seiner Dichtfläche 76 vom Ventilsitz 74 abgehoben ist, so ist der Ringraum 73 mit dem Ringraum 77 verbunden, so daß aus dem Pumpenarbeitsraum 22 Kraftstoff über den Rücklauf 78 abfließen kann und sich im Pumpenarbeitsraum 22 kein Druck aufbauen kann.From the pump working chamber 22 passes through the pump body 14 and the valve body 26, a connection 48 in the pressure chamber 40 of the fuel injection valve 12. The connection 48 is controlled by a control valve 70. The control valve 70 has a in a subsequent to the control pressure chamber 60 bore 71 of the valve body 26 tightly guided piston-shaped control valve member 72. The bore 71 has a formed by a radial extension, the control valve member 72 surrounding annular space 73 into which a leading to the pump working chamber 22 part of the connection 48 and a pressure chamber 40 leading part of the connection 48 opens. At the control pressure chamber 60 facing transition from the annular space 73 to the bore 71, a valve seat 74 is formed, with which the control valve member 72 cooperates with a sealing surface 76 formed on this. The starting from the annular space 73 to the control pressure chamber 60 arranged portion 171 of the bore 71 has a slightly smaller diameter than the starting from the annular space 73 the control pressure chamber 60 facing away arranged portion 271 of the bore 71. The control valve member 72 has accordingly in his in section 171 of the bore 71 guided portion 172 has a smaller diameter than in its guided in the section 271 of the bore 71 portion 272. The sealing surface 76 is formed on the control valve member 72 at the junction between the two regions 172 and 272. Between the sealing surface 76 and guided in the portion 171 of the bore 71 portion 172 of the control valve member 72, the control valve member 72 has a greatly reduced diameter portion 372 so that between the portion 372 of the control valve member 72 and the portion 171 of the bore 71, an annular space 77th is available. The annular space 77 has a connection to a low-pressure region, which may be, for example, a return 78 into the fuel reservoir 24. The spring chamber 46 is also connected to the return 78. When the control valve member 72 is in its closed position, in FIG it rests with its sealing surface 76 on the valve seat 74, the annular space 73 is separated from the annular space 77 and the pump chamber 22 is separated from the return line 78 so that 18 can build up pressure in the pump chamber 22 corresponding to the stroke of the pump piston. When the control valve member 72 is in an open position in which it is lifted with its sealing surface 76 from the valve seat 74, the annular space 73 is connected to the annular space 77, so that from the pump working chamber 22 fuel can flow through the return line 78 and in Pump working space 22 can not build up pressure.

Auf der dem Steuerdruckraum 60 abgewandten Seite des Steuerventilglieds 72 ist im Ventilkörper 26 oder dem Pumpenkörper 14 oder zwischen diesen ein Aktordruckraum 80 gebildet, der durch das Steuerventilglied 72 begrenzt wird. Das Steuerventilglied 72 ist somit von dem im Aktordruckraum 80 herrschenden Druck in Schließrichtung beaufschlagt. In Öffnungsrichtung ist das Steuerventilglied 72 von dem im Steuerdruckraum 60 herrschenden Druck und außerdem von einer zwischen dem Steuerkolben 62 und dem Steuerventilglied 72 eingespannten Rückstellfeder 82. Der Druck im Aktordruckraum 80 wird durch einen piezoelektrischen Aktor 84 gesteuert, der abhängig von einer an diesen angelegten elektrischen Spannung seine Ausdehnung, insbesondere seine Länge ändert und dadurch den Druck im Aktordruckraum 80 verändert. Der Aktor 84 ist mit einer elektronischen Steuereinrichtung 86 verbunden, durch die die am Aktor 84 anliegende Spannung bereitgestellt wird. Der Aktor 84 kann über einen hydraulischen Koppler mit dem Aktordruckraum 80 verbunden sein, um eine relativ geringe Längenänderung des Aktors 84 zu verstärken und relativ große Druckänderungen im Aktordruckraum 80 bewirken zu können. Wenn im Aktordruckraum 80 ein hoher Druck herrscht, so befindet sich das Steuerventilglied 72 gegen den im Steuerdruckraum 60 herrschenden Druck und gegen die Kraft der Rückstellfeder 82 in seiner Schließstellung, so daß der Pumpenarbeitsraum 22 vom Rücklauf 78 getrennt ist. Wenn im Aktordruckraum 80 ein geringer Druck herrscht, so befindet sich das Steuerventilglied 72 durch den im Steuerdruckraum 60 herrschenden Druck und die Rückstellfeder 82 bewirkt in seiner Öffnungsstellung, so daß der Pumpenarbeitsraum 22 mit dem Rücklauf 78 verbunden ist. Durch die Steuereinrichtung 86 wird auch die Förderpumpe 64 bzw. das Entlastungsventil 66 gesteuert, um den im Steuerdruckraum 60 herrschenden Druck abhängig von Betriebsbedingungen der Brennkraftmaschine einzustellen.On the side facing away from the control pressure chamber 60 side of the control valve member 72, an actuator pressure chamber 80 is formed in the valve body 26 or the pump body 14 or between them, which is limited by the control valve member 72. The control valve member 72 is thus acted upon by the pressure prevailing in the actuator pressure chamber 80 in the closing direction. In the opening direction, the control valve member 72 is of the pressure prevailing in the control pressure chamber 60 and also by a clamped between the control piston 62 and the control valve member 72 return spring 82. The pressure in Aktordruckraum 80 is controlled by a piezoelectric actuator 84 which depends on an applied to this Voltage its extent, in particular changes its length and thereby changes the pressure in the actuator pressure chamber 80. The actuator 84 is connected to an electronic control device 86 through which the voltage applied to the actuator 84 is provided. The actuator 84 may be connected via a hydraulic coupler to the actuator pressure chamber 80 in order to reinforce a relatively small change in length of the actuator 84 and to be able to effect relatively large pressure changes in the actuator pressure chamber 80. If a high pressure prevails in the actuator pressure chamber 80, then the control valve member 72 is against the pressure prevailing in the control pressure chamber 60 and against the force of the return spring 82 in its closed position, so that the pump working chamber 22 is separated from the return line 78. If there is a slight pressure in the actuator pressure chamber 80, then the control valve member 72 is in its open position by the pressure prevailing in the control pressure chamber 60 and the return spring 82, so that the pump working chamber 22 is connected to the return line 78. By the control device 86 and the feed pump 64 and the relief valve 66 is controlled to adjust the pressure prevailing in the control pressure chamber 60 pressure depending on operating conditions of the internal combustion engine.

Zwischen dem Aktordruckraum 80 und dem Steuerdruckraum 60 ist eine Verbindung 88 vorgesehen, in der ein zum Aktordruckraum 80 hin öffnendes Rückschlagventil 90 angeordnet ist. Wenn der Druck im Steuerdruckraum 60 höher ist als im Aktordruckraum 80, so öffnet das Rückschlagventil 90, so daß der Aktordruckraum 80 mit Kraftstoff befüllt werden kann. Wenn der Druck im Aktordruckraum 80 höher ist als im Steuerdruckraum 60, so schließt das Rückschlagventil 90, so daß der Aktordruckraum 80 vom Steuerdruckraum 60 getrennt ist.Between the actuator pressure chamber 80 and the control pressure chamber 60, a connection 88 is provided, in which a check valve 90 which opens toward the actuator pressure chamber 80 is arranged. When the pressure in the control pressure chamber 60 is higher than in the actuator pressure chamber 80, the check valve 90 opens, so that the actuator pressure chamber 80 can be filled with fuel. If the pressure in the actuator pressure chamber 80 is higher than in the control pressure chamber 60, so the check valve 90 closes, so that the Aktordruckraum 80 is separated from the control pressure chamber 60.

Nachfolgend wird die Funktion der Kraftstoffeinspritzeinrichtung erläutert. Beim Saughub des Pumpenkolbens 18 befindet sich das Steuerventilglied 72 in seiner Öffnungsstellung, wobei der Ringraum 77 eine Verbindung mit der Förderpumpe 64 aufweist, so daß Kraftstoff aus dem Kraftstoffvorratsbehälter 24 in den Pumpenarbeitsraum 22 gelangt. Beim Förderhub des Pumpenkolbens 18 wird der Beginn der Kraftstoffeinspritzung dadurch festgelegt, daß das Steuerventilglied 72 in seine Schließstellung bewegt wird. Hierzu wird durch die Steuereinrichtung 86 eine erhöhte Spannung an den Aktor 84 angelegt, so daß der Druck im Aktordruckraum 80 erhöht wird und das Steuerventilglied 72 in seine Schließstellung gelangt. Der Pumpenarbeitsraum 22 ist dann vom Rücklauf 78 getrennt und in diesem baut sich Hochdruck entsprechend dem Hub des Pumpenkolbens 18 auf.The function of the fuel injector will be explained below. When the suction stroke of the pump piston 18, the control valve member 72 is in its open position, wherein the annular space 77 has a connection with the feed pump 64, so that fuel from the fuel tank 24 passes into the pump working chamber 22. In the delivery stroke of the pump piston 18, the start of fuel injection is determined by moving the control valve member 72 to its closed position. For this purpose, an increased voltage is applied to the actuator 84 by the control device 86, so that the pressure in the actuator pressure chamber 80 is increased and the control valve member 72 in its closed position arrives. The pump working chamber 22 is then separated from the return line 78 and in this high pressure builds up according to the stroke of the pump piston 18.

Wenn der Druck im Pumpenarbeitsraum 22 und damit im Druckraum 40 des Kraftstoffeinspritzventils 12 so hoch ist, daß die durch diesen über die Druckschulter 42 auf das erste Einspritzventilglied 28 erzeugte Druckkraft größer ist als die Kraft der ersten Schließfeder 44, so öffnet das Kraftstoffeinspritzventil 12 indem das erste Einspritzventilglied 28 mit seiner Dichtfläche 34 vom Ventilsitz 36 abhebt und die wenigstens eine erste Einspritzöffnung 32 freigibt. Wenn im Steuerdruckraum 60 ein hoher Druck herrscht, so ist die durch den im Steuerdruckraum 60 herrschenden Druck, die zweite Schließfeder 144 und die Rückstellfeder 82 auf den Steuerkolben 62 und damit das zweite Einspritzventilglied 128 ausgeübte Schließkraft größer als die durch den im Druckraum 40 herrschenden Druck über die Druckfläche 142 auf das zweite Einspritzventilglied 128 ausgeübte Kraft, so daß das zweite Einspritzventilglied 128 in seiner geschlossenen Stellung verbleibt. Am Kraftstoffeinspritzventil 12 wird somit mit den ersten Einspritzöffnungen 32 nur ein Teil des gesamten Einspritzquerschnitts geöffnet, so daß entsprechend nur eine geringe Kraftstoffmenge eingespritzt wird.If the pressure in the pump chamber 22 and thus in the pressure chamber 40 of the fuel injection valve 12 is so high that the pressure generated by this via the pressure shoulder 42 to the first injection valve member 28 is greater than the force of the first closing spring 44, the fuel injection valve 12 opens by the first injection valve member 28 lifts off with its sealing surface 34 from the valve seat 36 and the at least one first injection port 32 releases. If there is high pressure in the control pressure chamber 60, the closing force exerted by the pressure prevailing in the control pressure chamber 60, the second closing spring 144 and the return spring 82 on the control piston 62 and thus the second injection valve member 128 is greater than the pressure prevailing in the pressure chamber 40 Force exerted on the second injection valve member 128 via the pressure surface 142 so that the second injection valve member 128 remains in its closed position. At the fuel injection valve 12, therefore, only part of the total injection cross section is opened with the first injection openings 32, so that correspondingly only a small amount of fuel is injected.

Wenn auch das zweite Einspritzventilglied 128 öffnen soll, so wird im Steuerdruckraum 60 ein geringer Druck eingestellt, so daß die durch den im Steuerdruckraum 60 herrschenden Druck, die zweite Schließfeder 144 und die Rückstellfeder 82 auf den Steuerkolben 62 und damit das zweite Einspritzventilglied 128 ausgeübte Kraft in Schließrichtung geringer ist als die durch den im Druckraum 40 herrschenden Druck über die Druckfläche 142 auf das zweite Einspritzventilglied 128 wirkende Kraft in Öffnungsrichtung, so daß zusätzlich zum ersten Einspritzventilglied 28 auch das zweite Einspritzventilglied 128 öffnet und gibt die zweiten Einspritzöffnungen 132 freigibt. Somit ist am Kraftstoffeinspritzventil 12 der gesamte Einspritzquerschnitt freigegeben und es wird eine größere Kraftstoffmenge eingespritzt. Das Ende der Kraftstoffeinspritzung wird dadurch bestimmt, daß durch die Steuereinrichtung 86 die Spannung am Aktor 84 verringert wird, wodurch der Druck im Aktordruckraum 80 verringert wird, so daß sich das Steuerventilglied 72 bewirkt durch den im Steuerdruckraum 60 herrschenden Druck und die Kraft der Rückstellfeder 82 in seine Öffnungsstellung bewegt. Der Pumpenarbeitsraum 22 ist dann mit dem Rücklauf 78 verbunden und in diesem kann sich kein Hochdruck mehr aufbauen. Das erste Einspritzventilglied 28 schließt dann infolge der Kraft der ersten Schließfeder 44. Wenn das erste Einspritzventilglied 28 mit seiner Dichtfläche 34 am Ventilsitz 36 anliegt, so ist Druckfläche 142 des zweiten Einspritzventilglieds 128 vom Druckraum 40 getrennt, so daß auch das zweite Einspritzventilglied 128 infolge der Kraft der zweiten Schließfeder 144 schließt. Es kann auch vorgesehen sein, daß am ersten Einspritzventilglied 28 ein Hubanschlag für das zweite Einspritzventilglied 128 angeordnet ist, durch den die Öffnungshubbewegung des zweiten Einspritzventilglieds 128 begrenzt wird. Wenn das erste Einspritzventilglied 28 geöffnet ist, so kann das zweite Einspritzventilglied 128 ebenfalls öffnen, bis es am Hubanschlag zur Anlage kommt. Wenn das erste Einspritzventilglied 28 schließt, so wird über diesen Hubanschlag das zweite Einspritzventilglied 128 zwangsweise ebenfalls geschlossen.Although the second injection valve member to open 128, so in the control pressure chamber 60, a low pressure is set, so that the pressure prevailing in the control pressure chamber 60, the second closing spring 144 and the return spring 82 on the control piston 62 and thus the second injection valve member 128 exerted force in the closing direction is less than the pressure prevailing in the pressure chamber 40 via the pressure surface 142 on the second injection valve member 128 acting force in the opening direction, so that in addition to the first Injector valve member 28 and the second injection valve member 128 opens and gives the second injection openings 132 releases. Thus, the entire injection cross section is released at the fuel injection valve 12 and it is injected a larger amount of fuel. The end of the fuel injection is determined by the control device 86, the voltage at the actuator 84 is reduced, whereby the pressure in the Aktordruckraum 80 is reduced, so that the control valve member 72 caused by the pressure prevailing in the control pressure chamber 60 and the force of the return spring 82nd moved to its open position. The pump chamber 22 is then connected to the return line 78 and in this no high pressure can build up. The first injection valve member 28 then closes due to the force of the first closing spring 44. When the first injection valve member 28 abuts with its sealing surface 34 on the valve seat 36, so pressure surface 142 of the second injection valve member 128 is separated from the pressure chamber 40, so that the second injection valve member 128 due to Force of the second closing spring 144 closes. It can also be provided that a stroke stop for the second injection valve member 128 is arranged on the first injection valve member 28, through which the opening stroke of the second injection valve member 128 is limited. When the first injection valve member 28 is opened, the second injection valve member 128 may also open until it comes to rest on the stroke stop. When the first injection valve member 28 closes, the second injection valve member 128 is forcibly also closed via this stroke stop.

Es kann vorgesehen sein, daß die durch die ersten Einspritzöffnungen 32 und die zweiten Einspritzöffnungen 132 gebildeten Einspritzquerschnitte zumindest annähernd gleich groß sind, so daß bei der Öffnung nur des ersten Einspritzventilglieds 28 der halbe gesamte Einspritzquerschnitt freigegeben wird. Alternativ kann auch vorgesehen sein, daß die ersten Einspritzöffnungen 32 einen größeren oder kleineren Einspritzquerschnitt bilden als die zweiten Einspritzöffnungen 132.It may be provided that the injection cross sections formed by the first injection openings 32 and the second injection openings 132 are at least approximately equal, so that when opening only the first injection valve member 28 of half total Injection cross section is released. Alternatively, it can also be provided that the first injection openings 32 form a larger or smaller injection cross section than the second injection openings 132.

In Figur 4 ist der Verlauf des Öffnungshubs h für das erste Einspritzventilglied 28 mit durchgezogener Linie und für das zweite Einspritzventilglied 128 mit gestrichelter Linie während eines Einspritzzykluses über der Zeit t dargestellt. Es kann vorgesehen sein, daß zu Beginn der Kraftstoffeinspritzung das Steuerventilglied 72 durch Einstellung eines hohen Drucks im Aktordruckraum 80 in seine Schließstellung gebracht wird, so daß der Pumpenarbeitsraum 22 vom Rücklauf 78 getrennt ist. Im Steuerdruckraum 60 wird ein hoher Druck eingestellt, so daß bei geringem Förderhub des Pumpenkolbens 18 zunächst nur das erste Einspritzventilglied 28 öffnet und am Kraftstoffeinspritzventil 12 nur ein Teil des gesamten Einspritzquerschnitts freigegeben wird. Es erfolgt dann eine Voreinspritzung einer geringen Kraftstoffmenge nur durch die ersten Einspritzöffnungen 32. Durch die Steuereinrichtung 86 wird anschließend die Spannung am Aktor 84 verringert, so daß der Druck im Aktordruckraum 80 sinkt und das Steuerventilglied 72 seine Öffnungsstellung einnimmt, so daß der Pumpenarbeitsraum 22 entlastet ist und das erste Einspritzventilglied 28 schließt und die Kraftstoffeinspritzung unterbrochen wird. Anschließend wird durch die Steuereinrichtung 86 die Spannung am Aktor 84 erhöht, so daß das Steuerventilglied 72 infolge des erhöhten Drucks im Aktordruckraum 80 wieder seine Schließstellung einnimmt. Bei zunehmendem Förderhub des Pumpenkolbens 18 kann der Druck im Steuerdruckraum 60 durch die Steuereinrichtung 86 verringert werden, so daß die Schließkraft auf das zweite Einspritzventilglied 128 verringert wird und zusätzlich auch das zweite Einspritzventilglied 128 öffnet, so daß am Kraftstoffeinspritzventil 12 der gesamte Einspritzquerschnitt freigegeben wird und eine Haupteinspritzung einer großen Kraftstoffmenge erfolgt. Der Druck im Steuerdruckraum 60 kann durch die Steuereinrichtung 86 schon zu Beginn der Haupteinspritzung verringert werden, so daß das zweite Einspritzventilglied 128 nur mit geringer zeitlicher Verzögerung nach dem ersten Einspritzventilglied 28 öffnet. Alternativ kann der Druck im Steuerdruckraum 60 durch die Steuereinrichtung 86 auch erst während des Verlaufs der Haupteinspritzung geöffnet werden, so daß das zweite Einspritzventilglied 128 mit größerer zeitlicher Verzögerung nach dem ersten Einspritzventilglied 28 öffnet wie dies in Figur 4 dargestellt ist. Es erfolgt dann eine Haupteinspritzung einer großen Kraftstoffmenge durch die ersten Einspritzöffnungen 32 und die zweiten Einspritzöffnungen 132.In FIG. 4 the course of the opening stroke h for the first injection valve member 28 is shown in solid line and for the second injection valve member 128 in dashed line during an injection cycle over the time t. It can be provided that at the beginning of the fuel injection, the control valve member 72 is brought by setting a high pressure in the actuator pressure chamber 80 in its closed position, so that the pump working chamber 22 is separated from the return line 78. In the control pressure chamber 60, a high pressure is set, so that at low delivery stroke of the pump piston 18 initially only the first injection valve member 28 opens and the fuel injection valve 12, only a portion of the entire injection cross section is released. There is then a pre-injection of a small amount of fuel only through the first injection ports 32. By the controller 86, the voltage at the actuator 84 is then reduced, so that the pressure in the actuator pressure chamber 80 decreases and the control valve member 72 assumes its open position, so that the pump working chamber 22 relieved is and the first injection valve member 28 closes and the fuel injection is interrupted. Subsequently, the voltage at the actuator 84 is increased by the control device 86, so that the control valve member 72 again assumes its closed position due to the increased pressure in the actuator pressure chamber 80. With increasing delivery stroke of the pump piston 18, the pressure in the control pressure chamber 60 can be reduced by the control device 86 so that the closing force is reduced to the second injection valve member 128 and in addition, the second injection valve member 128 opens, so that Fuel injection valve 12, the entire injection cross section is released and a main injection of a large amount of fuel takes place. The pressure in the control pressure chamber 60 can be reduced by the control device 86 already at the beginning of the main injection, so that the second injection valve member 128 only after a short time delay after the first injection valve member 28 opens. Alternatively, the pressure in the control pressure chamber 60 can also be opened by the control device 86 during the course of the main injection, so that the second injection valve member 128 opens with a larger time delay after the first injection valve member 28 as in FIG. 4 is shown. There is then a main injection of a large amount of fuel through the first injection ports 32 and the second injection ports 132nd

Es kann auch vorgesehen sein, daß bei bestimmten Betriebsparametern der Brennkraftmaschine, insbesondere bei geringer Last und/oder Drehzahl, wenn nur eine geringe Kraftstoffmenge eingespritzt wird, über den gesamten Förderhub des Pumpenkolbens 18 während der Vor- und Haupteinspritzung im Steuerdruckraum 60 durch die Steuereinrichtung 86 ein hoher Druck eingestellt wird, so daß nur das erste Einspritzventilglied 28 öffnet und das zweite Einspritzventilglied 128 geschlossen bleibt. Bei hoher Last und/oder Drehzahl der Brennkraftmaschine, wenn eine größere Kraftstoffmenge eingespritzt wird, kann während der Voreinspritzung im Steuerdruckraum 60 durch die Steuereinrichtung 86 ein hoher Druck eingestellt werden, so daß nur das erste Einspritzventilglied 28 öffnet, und während der Haupteinspritzung kann der Druck im Steuerdruckraum 60 durch die Steuereinrichtung 86 verringert werden, so daß zusätzlich auch das zweite Einspritzventilglied 128 öffnet.It can also be provided that at certain operating parameters of the internal combustion engine, especially at low load and / or speed when only a small amount of fuel is injected over the entire delivery stroke of the pump piston 18 during the pre-injection and main injection in the control pressure chamber 60 by the controller 86th a high pressure is set, so that only the first injection valve member 28 opens and the second injection valve member 128 remains closed. At high load and / or speed of the internal combustion engine, when a larger amount of fuel is injected, during the pilot injection in the control pressure chamber 60 by the controller 86, a high pressure can be set, so that only the first injection valve member 28 opens, and during the main injection, the pressure be reduced in the control pressure chamber 60 by the control device 86, so that in addition, the second injection valve member 128 opens.

Claims (14)

  1. Fuel injection device for an internal combustion engine having a high-pressure fuel pump (10) and one fuel injection valve (12) which is connected to the former for each cylinder of the internal combustion engine, the high-pressure fuel pump (10) having a pump piston (18) which is driven in a reciprocating movement by the internal combustion engine and delimits a pump working chamber (22) which is connected to a pressure chamber (40) of the fuel injection valve (12), the fuel injection valve (12) having at least one first injection valve element (28), by which at least one first injection opening (32) is controlled and which, loaded by the pressure which prevails in the pressure chamber (40), can move in an opening direction (29) counter to a closing force in order to release the at least one first injection opening (32), and having a control valve (70) which is actuated by a piezoelectric actuator (84) and by which a connection of the pump working chamber (22) to a relief region (78) is controlled at least indirectly, characterized in that the fuel injection valve (12) has a second injection valve element (128) which is guided displaceably within the first injection valve element (28) of hollow configuration and by which at least one second injection opening (132) is controlled and which, loaded by the pressure which prevails in the pressure chamber (40), can move in an opening direction (29) counter to a closing force, in that the second injection valve element (128) is loaded at least indirectly in a closing direction by the pressure which prevails in a fuel-filled control pressure chamber (60), and in that the pressure which prevails in the control pressure chamber (60) is controlled variably as a function of operating conditions of the internal combustion engine.
  2. Fuel injection device according to Claim 1, characterized in that the pressure which prevails in an actuator pressure chamber (80) is controlled by the piezoelectric actuator (84), in that the control valve (70) has a control valve element (72) which can be moved between a closed position, in which the pump working chamber (22) is separated from the relief region (78), and an open position, in which the pump working chamber (22) is connected to the relief region (78), and in that the control valve element (72) is loaded in a closing direction by the pressure which prevails in the actuator pressure chamber (80).
  3. Fuel injection device according to Claim 2, characterized in that, on its end side which faces away from the actuator pressure chamber (80), the control valve element (72) is loaded in an opening direction by the pressure which prevails in the control pressure chamber (60).
  4. Fuel injection device according to Claim 2 or 3, characterized in that the control valve element (72) is loaded in an opening direction by a restoring spring (82).
  5. Fuel injection device according to one of Claims 2 to 4, characterized in that the control pressure chamber (60) has a connection (88) to the actuator pressure chamber (80), in which connection (88) a non-return valve (90) is arranged which opens towards the actuator pressure chamber (80).
  6. Fuel injection device according to one of Claims 1 to 5, characterized in that the control pressure chamber (60) is delimited by a control piston (62) which acts on the second injection valve element (128), and in that the second injection valve element (128) is additionally loaded in the closing direction by a closing spring (144) which is preferably supported on the control piston (62).
  7. Fuel injection device according to Claims 4 and 6, characterized in that the restoring spring (82) is clamped between the control valve element (72) and the control piston (62).
  8. Fuel injection device according to one of the preceding claims, characterized in that the pressure in the control pressure chamber (60) is generated by a delivery pump (64).
  9. Fuel injection device according to Claim 8, characterized in that the operation of the delivery pump (64) is controlled by a control device (86) in such a way that the said delivery pump (64) generates the pressure in the control pressure chamber (60), which pressure is variable as a function of operating conditions of the internal combustion engine.
  10. Fuel injection device according to Claim 8, characterized in that the pressure in the control pressure chamber (60) is set variably as a function of operating conditions of the internal combustion engine by a relief valve (66) which is actuated by a control device (86).
  11. Fuel injection device according to one of the preceding claims, characterized in that, at low load and/or rotational speed of the internal combustion engine, a high pressure is set in the control pressure chamber (60), with the result that the second injection valve element (128) remains in its closed position and only the first injection valve element (28) opens and releases the at least one first injection opening (32), and in that, at high load and/or rotational speed of the internal combustion engine, a low pressure is set in the control pressure chamber (60), with the result that, in addition, the second injection valve element (128) also opens and releases the at least one second injection opening (132).
  12. Fuel injection device according to one of the preceding claims, characterized in that, at the beginning of an injection cycle, a high pressure is set in the control pressure chamber (60), with the result that the second injection valve element (128) remains in its closed position and only the first injection valve element (28) opens and releases the at least one first injection opening (32), and in that, in the further course of the injection cycle, a low pressure is set in the control pressure chamber (60), with the result that, in addition, the second injection valve element (128) also opens and releases the at least one second injection opening (132).
  13. Fuel injection device according to Claim 12, characterized in that the injection cycle begins with a preinjection of a small fuel quantity, while a high pressure is set in the control pressure chamber (60), and in that the injection cycle continues with a main injection of a larger fuel quantity, while a low pressure is set in the control pressure chamber (60).
  14. Fuel injection device according to Claim 13, characterized in that a low pressure is not set in the control pressure chamber (60) until during the course of the main injection.
EP02796496A 2001-12-20 2002-11-11 Fuel-injection device for an internal combustion engine Expired - Lifetime EP1458970B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10162651 2001-12-20
DE10162651A DE10162651A1 (en) 2001-12-20 2001-12-20 Fuel injection device for an internal combustion engine
PCT/DE2002/004160 WO2003054374A1 (en) 2001-12-20 2002-11-11 Fuel-injection device for an internal combustion engine

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EP1458970A1 EP1458970A1 (en) 2004-09-22
EP1458970B1 true EP1458970B1 (en) 2008-07-09

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US (1) US6896208B2 (en)
EP (1) EP1458970B1 (en)
JP (1) JP2005513331A (en)
KR (1) KR20040067853A (en)
CN (1) CN100379975C (en)
DE (2) DE10162651A1 (en)
PL (1) PL362307A1 (en)
WO (1) WO2003054374A1 (en)

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CN1492966A (en) 2004-04-28
JP2005513331A (en) 2005-05-12
EP1458970A1 (en) 2004-09-22
DE10162651A1 (en) 2003-09-04
CN100379975C (en) 2008-04-09
US20040144364A1 (en) 2004-07-29
DE50212491D1 (en) 2008-08-21
PL362307A1 (en) 2004-10-18
WO2003054374A1 (en) 2003-07-03
US6896208B2 (en) 2005-05-24
KR20040067853A (en) 2004-07-30

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