EP1458970A1 - Fuel-injection device for an internal combustion engine - Google Patents

Fuel-injection device for an internal combustion engine

Info

Publication number
EP1458970A1
EP1458970A1 EP02796496A EP02796496A EP1458970A1 EP 1458970 A1 EP1458970 A1 EP 1458970A1 EP 02796496 A EP02796496 A EP 02796496A EP 02796496 A EP02796496 A EP 02796496A EP 1458970 A1 EP1458970 A1 EP 1458970A1
Authority
EP
European Patent Office
Prior art keywords
injection
control
valve member
pressure chamber
pressure
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.)
Granted
Application number
EP02796496A
Other languages
German (de)
French (fr)
Other versions
EP1458970B1 (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

Links

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 known from DE 198 35 494 AI. This fuel injector has the for each cylinder
  • the high-pressure fuel pump has a pump piston which is driven by the internal combustion engine in a stroke movement and which delimits a pump work chamber which is connected to a pressure chamber of the fuel injection valve.
  • the fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which, when acted upon by the pressure prevailing in the pressure chamber, can be moved against a closing force in an opening direction to release the at least one injection opening.
  • the injection valve member moves in the opening direction and releases the at least one injection opening.
  • the injection cross section that is controlled by the injection valve member is always the same size. This does not enable optimal fuel injection under all operating conditions of the internal combustion engine.
  • the fuel injection device according to the invention with the features according to claim 1 has the advantage that additional injection cross-section can be released or closed by the second injection valve member with the at least one second injection opening, so that the injection cross-section to the
  • the injection cross section is controlled in a simple manner by the variable pressure in the control pressure chamber.
  • Claim 8 enables 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 enables combustion with low noise and pollutant emissions from the internal combustion engine.
  • FIG. 1 shows a fuel injection device for an internal combustion engine in a schematic illustration in a longitudinal section
  • FIG. 2 shows an enlarged section of a section of the fuel injection device designated by II in FIG. 1
  • FIG. 3 shows an enlarged section of the fuel injection device designated by III in FIG. 1
  • FIG. 4 Stroke profiles 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 a high-pressure fuel pump 10 and a fuel injection valve 12 connected to each cylinder of the internal combustion engine. When designed as a pump-line-nozzle system, the high-pressure fuel pump 10 is removed from the
  • Fuel injection valve 12 arranged and connected to it via a line.
  • the fuel injection device is designed as a pump-nozzle system, the high-pressure fuel pump 10 and the
  • Fuel injection valve 12 are connected directly to one another and form a structural unit.
  • the high-pressure fuel pump 10 has one in one
  • the pump piston 18 delimits a pump working chamber 22 in the cylinder 16, in which fuel is compressed under high pressure during the delivery stroke of the pump piston 18.
  • fuel from a fuel reservoir 24 of the motor vehicle is supplied to the pump working chamber 22 in a manner not shown.
  • the fuel injection valve 12 has a valve body 26, which can be designed in several parts, in which a first injection valve member 28 is guided in a bore 30 in a longitudinally displaceable manner.
  • the valve body 26 has at least one first, preferably a plurality of first injection openings 32 at its end region facing the combustion chamber of the cylinder of the internal combustion engine, which are arranged distributed over the circumference of the valve body 26.
  • the first injection valve member 28 has, for example, an approximately conical sealing surface 34 on its end region facing the combustion chamber, 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 lead away.
  • annular space 38 between the injection valve member 28 and the bore 30 towards the valve seat 36, which in its end region facing away from the valve seat 36 is the first by a radial expansion of the bore 30
  • Injection valve member 28 passes surrounding pressure chamber 40.
  • the first injection valve member 28 has a pressure shoulder 42 at the level of the pressure chamber 40 by reducing the cross section.
  • a first prestressed closing spring 44 acts through which the first Injection valve member 28 is pressed toward the valve seat 36.
  • the first closing spring 44 is arranged in a spring chamber 46 of the valve body 26, which adjoins the bore 30.
  • Fuel injection valve 12 is hollow and a second injection valve member 128 is slidably guided therein in a bore formed coaxially in injection valve member 28.
  • the second injection valve member 128 controls at least one second injection opening 132 in the valve body 26.
  • the at least one second injection opening 132 is 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, for example, an approximately conical sealing surface 134 on its end region facing the combustion chamber, 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 lead away.
  • the second injection valve member 128 can be formed in two parts and have a part which has the sealing surface 134 and faces the combustion chamber and a second part which adjoins the first part away from the combustion chamber. Near the end of the second injection valve member 128 on the combustion chamber side, a pressure surface 142 is formed thereon, on which the pressure prevailing in the pressure chamber 40 acts when the first injection valve member 28 is open.
  • a control pressure chamber 60 is formed in the valve body 26, as shown in FIGS. 1 and 2, in which a second closing spring 144 acting on the second injection valve member 128 is arranged.
  • the control pressure chamber 60 is somewhat smaller in diameter than the spring chamber 46.
  • the first Injection valve member 28 protrudes with its end into spring chamber 46 and is supported on first closing spring 44.
  • the first closing spring 44 is supported with its end facing away from the first injection valve member 28 on an between the spring chamber 46 and the
  • Control pressure chamber 60 arranged sleeve 47.
  • the sleeve 47 is in turn supported on an annular shoulder formed at the transition from the spring chamber 46 to the control pressure chamber 60 by the reduction in diameter.
  • the sleeve 47 can be pressed into the spring chamber 46 and thus fixed, or alternatively can 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 projects through the sleeve 47 into the control pressure chamber 60 and is supported on a control piston 62 delimiting the control pressure chamber 60 towards the spring chamber 46.
  • the second closing spring 144 is supported on the side of the control piston 62 delimiting the control pressure chamber 146.
  • 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 pressurized space 60 is supplied with fuel under pressure, for example by means of a feed pump 64.
  • the feed pump 64 can also serve to deliver fuel into the pump work space 22 during the suction stroke of the pump piston 18.
  • the pressure in the control pressure chamber 60 is variably set depending on operating conditions of the internal combustion engine, such as speed, load, temperature and others.
  • the feed pump 64 can be operated at a correspondingly variable speed, or a relief valve 66 can be provided between the feed pump 64 and the control pressure chamber 60, by means of which the pressure in the control pressure chamber 60 is controlled by the relief valve 66 opening or closing a connection to a low-pressure region ,
  • a connection 48 leads from the pump work chamber 22 through the pump body 14 and the valve body 26 into 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 piston-shaped control valve member 72 which is tightly guided in a bore 71 of the valve body 26 adjoining the control pressure chamber 60.
  • the bore 71 has an annular space 73 formed by a radial expansion and surrounding the control valve member 72, into which a part of the connection 48 leading to the pump working space 22 and a part of the connection 48 leading to the pressure space 40 open.
  • a valve seat 74 is formed, with which the control valve member 72 cooperates with a sealing surface 76 formed thereon.
  • the section 171 of the bore 71 arranged starting from the annular space 73 towards the control pressure chamber 60 has a somewhat smaller diameter than the section 271 of the bore 71 arranged away from the annular space 73 and away from the control pressure chamber 60.
  • the control valve member 72 accordingly has in its section 171 of the bore 71 performed area 172 has a smaller diameter than in its area 272 guided in section 271 of the bore 71.
  • the sealing surface 76 is formed on the control valve member 72 at the transition between the two areas 172 and 272.
  • control valve member 72 has a region 372 which is greatly reduced in diameter, so that between the region 372 of the control valve member 72 and the section 171 the
  • annular space 77 is present.
  • the annular space 77 is connected to a low-pressure area, which can be, for example, a return 78 into the fuel reservoir 24.
  • the spring chamber 46 is also connected to the return 78. If that
  • Control valve member 72 is in its closed position, in which 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 working space 22 is separated from the return 78 so that pressure can build up in the pump working space 22 in accordance with the stroke of the pump piston 18. If that
  • Control valve member 72 is in an open position, in which this 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 fuel can flow out of the pump working space 22 via the return 78 and there is none in the pump working space 22 Can build pressure.
  • an actuator pressure chamber 80 is formed in the valve body 26 or the pump body 14 or between these, which is delimited 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 from the pressure prevailing in the control pressure chamber 60 and also from a return spring 82 clamped between the control piston 62 and the control valve member 72.
  • the pressure in the actuator pressure chamber 80 is controlled by a piezoelectric actuator 84, which is dependent on an electrical applied to it Voltage changes its extent, in particular its length, and thereby changes the pressure in the actuator pressure chamber 80.
  • the actuator 84 is connected to an electronic control device 86, by which the voltage applied to the actuator 84 is provided.
  • the actuator 84 can be connected to the actuator pressure chamber 80 via a hydraulic coupler in order to amplify a relatively small change in length of the actuator 84 and to be able to bring about relatively large pressure changes in the actuator pressure chamber 80. If there is a high pressure in the actuator pressure chamber 80, the control valve member 72 is located 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 space 22 is separated from the return 78.
  • control valve member 72 If there is a low pressure in the actuator pressure chamber 80, then the control valve member 72 is in the open position due to the pressure prevailing in the control pressure chamber 60 and the return spring 82 causes it to open, so that the pump working chamber 22 is connected to the return 78.
  • the feed pump 64 or the relief valve 66 is also controlled by the control device 86 in order to adjust the pressure prevailing in the control pressure chamber 60 as a function of 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 opening towards the actuator pressure chamber 80 is arranged. If 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, the check valve 90 closes, so that the actuator pressure chamber 80 is separated from the control pressure chamber 60.
  • 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 78 and high pressure builds up in it in accordance with the stroke of the pump piston 18.
  • Pressure chamber 40 of the fuel injection valve 12 is so high that the pressure force generated by it via the pressure shoulder 42 on 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 with its sealing surface 34 from the valve seat 36 and the at least one first injection opening 32 opens. If a high pressure prevails 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 closing force prevailing by the pressure 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, only a part of the entire injection cross section is thus opened with the first injection openings 32, so that correspondingly only a small amount of fuel is injected.
  • the second injection valve member 128 is also to open, a low pressure is set in the control pressure chamber 60, so that the force exerted by the pressure 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 in the closing direction is less than the force acting on the second injection valve member 128 in the opening direction due to the pressure prevailing in the pressure chamber 40 via the pressure surface 142, so that in addition to the first Injection valve member 28 also opens second injection valve member 128 and releases second injection openings 132.
  • the entire injection cross section is released at the fuel injection valve 12 and a larger amount of fuel is injected.
  • Fuel injection is determined in that the voltage at the actuator 84 is reduced by the control device 86, whereby the pressure in the actuator pressure chamber 80 is reduced, so that the control valve member 72 is caused by the pressure prevailing in the control pressure chamber 60 and the force of the return spring 82 in its opening division emotional.
  • the pump work chamber 22 is then connected to the return 78 and no high pressure can build up in it.
  • the first injector member 28 then closes due to the force of the first closing spring 44.
  • Injection valve member 28 rests with its sealing surface 34 on the valve seat 36, so the 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 also closes due to the force of the second closing spring 144. It can also be provided that a stroke stop for the second injection valve element 128 is arranged on the first injection valve element 28, by means of which the opening stroke movement of the second injection valve element 128 is limited. If the first injection valve member 28 is open, the second injection valve member 128 can 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 also forcibly 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 the same size, so that when only the first injection valve member 28 is opened, half of the 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 shows the course of the opening stroke h for the first injection valve member 28 with a solid line and for the second injection valve member 128 with a dashed line during an injection cycle over time t. It can be provided that at the beginning of the
  • control valve member 72 is brought into its closed position by setting a high pressure in the actuator pressure chamber 80, so that the pump working chamber 22 is separated from the return 78.
  • a high pressure is set in the control pressure chamber 60, so that when the delivery stroke of the pump piston 18 is short, only the first injection valve member 28 opens and on
  • Fuel injection valve 12 is released only part of the total injection cross section. A small quantity of fuel is then pre-injected only through the first injection openings 32. The voltage at the actuator 84 is then reduced by the control device 86, so that the pressure in the actuator pressure chamber 80 drops and the control valve member 72 assumes its open position, so that the pump working chamber 22 is relieved is and the first injection valve member 28 closes and the
  • Fuel injection is interrupted.
  • the control device 86 then increases the voltage at the actuator 84, so that the control valve member 72 resumes 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 on the second injection valve member 128 is reduced and, in addition, the second injection valve member 128 also opens, so that on 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 opens after the first injection valve member 28 only with a slight time delay.
  • the pressure in the control pressure chamber 60 can only be opened by the control device 86 during the course of the main injection, so that the second injection valve member 128 opens after the first injection valve member 28 with a greater time delay, as shown in FIG. There is then a main injection of a large amount of fuel through the first injection openings 32 and the second injection openings 132.
  • 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 by the control device 86 during the pilot injection in the control pressure chamber 60, so that only the first injection valve member 28 opens, and during the main injection, the pressure can can be reduced in the control pressure chamber 60 by the control device 86, so that the second injection valve member 128 also opens.

Abstract

The invention relates to a fuel-injection device comprising a high-pressure fuel pump (10) for each cylinder of the internal combustion engine. Said pump has a working chamber (22) and a fuel-injection valve (12) connected to the latter. A connection from the working chamber (22) to a relief area (78) is controlled by a control valve (70) that is actuated by means of a piezoelectric actuator (84). The fuel-injection valve (12) comprises two concentric injection valve members (28, 128), which are used to control at least a first and a second injection orifice (32, 132) and can be displaced in an opening direction (29) in opposition to a closing force, by means of the pressure created in the working chamber (22). The second injection valve member (128) is at least indirectly subjected to the pressure prevailing in the fuel-filled pressure control chamber (60) in a closing direction.

Description

KRAFTSTOFFEINSPRITZEINRICHTUNG FUER EINE BRENNKRAFTMASCHINE FUEL INJECTION DEVICE FOR AN INTERNAL COMBUSTION ENGINE
Kraftstoffeinspritzeinrichtung für eine BrennkraftmaschineFuel injection device for an internal combustion engine
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 AI bekannt. Diese Kraftstoffeinspritzeinrichtung weist für jeden Zylinder derSuch a fuel injection device is known from DE 198 35 494 AI. This fuel injector has the for each cylinder
Brennkraftmaschine eine Kraftstoffhochdruckpumpe und ein mit dieser verbundenes Kraftstoffeinspritzventil auf. Die Kraftstoff ochdruckpumpe 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 einemInternal combustion engine a high-pressure fuel pump and a fuel injection valve connected to this. The high-pressure fuel pump has a pump piston which is driven by the internal combustion engine in a stroke movement and which delimits a pump work chamber which is connected to a pressure chamber of the fuel injection valve. The fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which, when acted upon by the pressure prevailing in the pressure chamber, can be moved against a closing force in an opening direction to release the at least one injection opening. By means of a control valve actuated by means of a piezoelectric actuator, a connection of the pump work space to a is made at least indirectly for controlling the fuel injection
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.Relief chamber controlled. If the pressure in the pump work chamber and thus in the pressure chamber of the fuel injector reaches the opening pressure, then the injection valve member moves in the opening direction and releases the at least one injection opening. The injection cross section that is controlled by the injection valve member is always the same size. This does not enable optimal 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 dieThe fuel injection device according to the invention with the features according to claim 1 has the advantage that additional injection cross-section can be released or closed by the second injection valve member with the at least one second injection opening, so that the injection cross-section to the
Betriebsbedingungen der Brennkraftmaschine optimal angepasst werden kann. Die Steuerung des Einspritzquerschnitts erfolgt dabei in einfacher Weise durch den variablen Druck im Steuerdruckraum.Operating conditions of the internal combustion engine can be optimally adjusted. The injection cross section is controlled 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 gemäßAdvantageous refinements and developments of the fuel injection device according to the invention are specified in the dependent claims. The embodiment according to claim 5 enables extensive pressure equalization on the control valve member. The training according to
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 .Claim 8 enables 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 enables combustion with low noise and pollutant emissions from the internal combustion engine.
Zeichnung 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 .drawing An embodiment of the invention is shown in the drawing and explained in more detail in the following description. 1 shows a fuel injection device for an internal combustion engine in a schematic illustration in a longitudinal section, FIG. 2 shows an enlarged section of a section of the fuel injection device designated by II in FIG. 1, FIG. 3 shows an enlarged section of the fuel injection device designated by III in FIG. 1 and FIG. 4 Stroke profiles 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 eineIn Figures 1 to 3 is one
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 vomFuel injection device for an internal combustion engine of a motor vehicle 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 a high-pressure fuel pump 10 and a fuel injection valve 12 connected to each cylinder of the internal combustion engine. When designed as a pump-line-nozzle system, the high-pressure fuel pump 10 is removed from the
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 dasFuel injection valve 12 arranged and connected to it via a line. In the illustrated embodiment, the fuel injection device is designed as a pump-nozzle system, the high-pressure fuel pump 10 and the
Kraftstoffeinspritzventil 12 direkt miteinander verbunden sind und eine Baueinheit bilden. Die Kraftstoffhochdruckpumpe 10 weist einen in einerFuel injection valve 12 are connected directly to one another and form a structural unit. The high-pressure fuel pump 10 has one in one
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.Cylinder bore 16 in a pump body 14 tightly guided 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 delimits a pump working chamber 22 in the cylinder 16, in which fuel is compressed under high pressure during the delivery stroke of the pump piston 18. During the suction stroke of the pump piston 18, fuel from a fuel reservoir 24 of the motor vehicle is supplied to the pump working chamber 22 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 ersteAs shown in FIGS. 1 and 3, the fuel injection valve 12 has a valve body 26, which can be designed in several parts, in which a first injection valve member 28 is guided in a bore 30 in a longitudinally displaceable manner. As shown in FIG. 2, the valve body 26 has at least one first, preferably a plurality of first injection openings 32 at its end region facing the combustion chamber of the cylinder of the internal combustion engine, which are arranged distributed over the circumference of the valve body 26. The first injection valve member 28 has, for example, an approximately conical sealing surface 34 on its end region facing the combustion chamber, 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 lead away. In the valve body 26 there is an annular space 38 between the injection valve member 28 and the bore 30 towards the valve seat 36, which in its end region facing away from the valve seat 36 is the first by a radial expansion of the bore 30
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 .Injection valve member 28 passes surrounding pressure chamber 40. The first injection valve member 28 has a pressure shoulder 42 at the level of the pressure chamber 40 by reducing the cross section. At the end of the first injection valve member 28 facing away from the combustion chamber, a first prestressed closing spring 44 acts through which the first Injection valve member 28 is pressed toward the valve seat 36. 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 desThe first injection valve member 28 of the
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 Einspritzöfnung 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.Fuel injection valve 12 is hollow and a second injection valve member 128 is slidably guided therein in a bore formed coaxially in injection valve member 28. The second injection valve member 128 controls at least one second injection opening 132 in the valve body 26. The at least one second injection opening 132 is 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, for example, an approximately conical sealing surface 134 on its end region facing the combustion chamber, 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 lead away. The second injection valve member 128 can be formed in two parts and have a part which has the sealing surface 134 and faces the combustion chamber and a second part which adjoins the first part away from the combustion chamber. Near the end of the second injection valve member 128 on the combustion chamber side, a pressure surface 142 is formed thereon, on which the pressure prevailing in the pressure chamber 40 acts 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 demFollowing the spring chamber 46 away from the combustion chamber, a control pressure chamber 60 is formed in the valve body 26, as shown in FIGS. 1 and 2, in which a second closing spring 144 acting on the second injection valve member 128 is arranged. The control pressure chamber 60 is somewhat smaller in diameter than the spring chamber 46. The first Injection valve member 28 protrudes with its end into spring chamber 46 and is supported on first closing spring 44. The first closing spring 44 is supported with its end facing away from the first injection valve member 28 on an between the spring chamber 46 and the
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.Control pressure chamber 60 arranged sleeve 47. The sleeve 47 is in turn supported on an annular shoulder formed at the transition from the spring chamber 46 to the control pressure chamber 60 by the reduction in diameter. The sleeve 47 can be pressed into the spring chamber 46 and thus fixed, or alternatively can 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 projects through the sleeve 47 into the control pressure chamber 60 and is supported on a control piston 62 delimiting the control pressure chamber 60 towards the spring chamber 46. The second closing spring 144 is supported on the side of the control piston 62 delimiting the control pressure chamber 146. 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 S euerdruckraum 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. 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.The pressurized space 60 is supplied with fuel under pressure, for example by means of a feed pump 64. The feed pump 64 can also serve to deliver fuel into the pump work space 22 during the suction stroke of the pump piston 18. The pressure in the control pressure chamber 60 is variably set depending on operating conditions of the internal combustion engine, such as speed, load, temperature and others. For this purpose, the feed pump 64 can be operated at a correspondingly variable speed, or a relief valve 66 can be provided between the feed pump 64 and the control pressure chamber 60, by means of which the pressure in the control pressure chamber 60 is controlled by the relief valve 66 opening or closing a connection to a low-pressure region , A connection 48 leads from the pump work chamber 22 through the pump body 14 and the valve body 26 into 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 piston-shaped control valve member 72 which is tightly guided in a bore 71 of the valve body 26 adjoining the control pressure chamber 60. The bore 71 has an annular space 73 formed by a radial expansion and surrounding the control valve member 72, into which a part of the connection 48 leading to the pump working space 22 and a part of the connection 48 leading to the pressure space 40 open. At the transition from the annular space 73 to the bore 71 facing the control pressure chamber 60, a valve seat 74 is formed, with which the control valve member 72 cooperates with a sealing surface 76 formed thereon. The section 171 of the bore 71 arranged starting from the annular space 73 towards the control pressure chamber 60 has a somewhat smaller diameter than the section 271 of the bore 71 arranged away from the annular space 73 and away from the control pressure chamber 60. The control valve member 72 accordingly has in its section 171 of the bore 71 performed area 172 has a smaller diameter than in its area 272 guided in section 271 of the bore 71. The sealing surface 76 is formed on the control valve member 72 at the transition between the two areas 172 and 272.
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 derBetween the sealing surface 76 and the region 172 of the control valve member 72 guided in the section 171 of the bore 71, the control valve member 72 has a region 372 which is greatly reduced in diameter, so that between the region 372 of the control valve member 72 and the section 171 the
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 dasBore 71 an annular space 77 is present. The annular space 77 is connected to a low-pressure area, which can be, for example, a return 78 into the fuel reservoir 24. The spring chamber 46 is also connected to the return 78. If that
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 dasControl valve member 72 is in its closed position, in which 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 working space 22 is separated from the return 78 so that pressure can build up in the pump working space 22 in accordance with the stroke of the pump piston 18. If that
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.Control valve member 72 is in an open position, in which this 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 fuel can flow out of the pump working space 22 via the return 78 and there is none in the pump working space 22 Can build 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 of the control valve member 72 facing away from the control pressure chamber 60, an actuator pressure chamber 80 is formed in the valve body 26 or the pump body 14 or between these, which is delimited 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 from the pressure prevailing in the control pressure chamber 60 and also from a return spring 82 clamped between the control piston 62 and the control valve member 72. The pressure in the actuator pressure chamber 80 is controlled by a piezoelectric actuator 84, which is dependent on an electrical applied to it Voltage changes its extent, in particular its length, and thereby changes the pressure in the actuator pressure chamber 80. The actuator 84 is connected to an electronic control device 86, by which the voltage applied to the actuator 84 is provided. The actuator 84 can be connected to the actuator pressure chamber 80 via a hydraulic coupler in order to amplify a relatively small change in length of the actuator 84 and to be able to bring about relatively large pressure changes in the actuator pressure chamber 80. If there is a high pressure in the actuator pressure chamber 80, the control valve member 72 is located 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 space 22 is separated from the return 78. If there is a low pressure in the actuator pressure chamber 80, then the control valve member 72 is in the open position due to the pressure prevailing in the control pressure chamber 60 and the return spring 82 causes it to open, so that the pump working chamber 22 is connected to the return 78. The feed pump 64 or the relief valve 66 is also controlled by the control device 86 in order to adjust the pressure prevailing in the control pressure chamber 60 as a function of 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.A connection 88 is provided between the actuator pressure chamber 80 and the control pressure chamber 60, in which a check valve 90 opening towards the actuator pressure chamber 80 is arranged. If 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, the check valve 90 closes, so that the actuator pressure chamber 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 desThe function of the fuel injection device is explained below. During the suction stroke of the pump piston 18, the control valve member 72 is in its open position, the annular space 77 being connected to the feed pump 64 so that fuel from the fuel reservoir 24 enters the pump work chamber 22. During the delivery stroke of the
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.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 78 and high pressure builds up in it in accordance with the stroke of the pump piston 18.
Wenn der Druck im Pumpenarbeitsraum 22 und damit imIf the pressure in the pump work chamber 22 and thus in
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 erstePressure chamber 40 of the fuel injection valve 12 is so high that the pressure force generated by it via the pressure shoulder 42 on 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
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 Kraf stoffeinspritzventil 12 wird somit mit den ersten Einspritzöffnungen 32 nur ein Teil des gesamten Einspritzquerschnitts geöffnet, so daß entsprechend nur eine geringe Kraftstoffmenge eingespritzt wird.Injection valve member 28 lifts with its sealing surface 34 from the valve seat 36 and the at least one first injection opening 32 opens. If a high pressure prevails 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 closing force prevailing by the pressure 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, only a part of the entire injection cross section is thus 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 derIf the second injection valve member 128 is also to open, a low pressure is set in the control pressure chamber 60, so that the force exerted by the pressure 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 in the closing direction is less than the force acting on the second injection valve member 128 in the opening direction due to the pressure prevailing in the pressure chamber 40 via the pressure surface 142, so that in addition to the first Injection valve member 28 also opens second injection valve member 128 and releases second injection openings 132. Thus, the entire injection cross section is released at the fuel injection valve 12 and a larger amount of fuel is injected. The end of
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 Öffnungssteilung 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 ersteFuel injection is determined in that the voltage at the actuator 84 is reduced by the control device 86, whereby the pressure in the actuator pressure chamber 80 is reduced, so that the control valve member 72 is caused by the pressure prevailing in the control pressure chamber 60 and the force of the return spring 82 in its opening division emotional. The pump work chamber 22 is then connected to the return 78 and no high pressure can build up in it. The first injector member 28 then closes due to the force of the first closing spring 44. When the first
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.Injection valve member 28 rests with its sealing surface 34 on the valve seat 36, so the 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 also closes due to the force of the second closing spring 144. It can also be provided that a stroke stop for the second injection valve element 128 is arranged on the first injection valve element 28, by means of which the opening stroke movement of the second injection valve element 128 is limited. If the first injection valve member 28 is open, the second injection valve member 128 can 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 also forcibly 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 can be provided that the injection cross sections formed by the first injection openings 32 and the second injection openings 132 are at least approximately the same size, so that when only the first injection valve member 28 is opened, half of the 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 derFIG. 4 shows the course of the opening stroke h for the first injection valve member 28 with a solid line and for the second injection valve member 128 with a dashed line during an injection cycle over time t. It can be provided that at the beginning of the
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 amFuel injection, the control valve member 72 is brought into its closed position by setting a high pressure in the actuator pressure chamber 80, so that the pump working chamber 22 is separated from the return 78. A high pressure is set in the control pressure chamber 60, so that when the delivery stroke of the pump piston 18 is short, only the first injection valve member 28 opens and on
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 dieFuel injection valve 12 is released only part of the total injection cross section. A small quantity of fuel is then pre-injected only through the first injection openings 32. The voltage at the actuator 84 is then reduced by the control device 86, so that the pressure in the actuator pressure chamber 80 drops and the control valve member 72 assumes its open position, so that the pump working chamber 22 is relieved is and the first injection valve member 28 closes and the
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.Fuel injection is interrupted. The control device 86 then increases the voltage at the actuator 84, so that the control valve member 72 resumes 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 on the second injection valve member 128 is reduced and, in addition, the second injection valve member 128 also opens, so that on 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 opens after the first injection valve member 28 only with a slight time delay. Alternatively, the pressure in the control pressure chamber 60 can only be opened by the control device 86 during the course of the main injection, so that the second injection valve member 128 opens after the first injection valve member 28 with a greater time delay, as shown in FIG. There is then a main injection of a large amount of fuel through the first injection openings 32 and the second injection openings 132.
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 for certain operating parameters of the internal combustion engine, in particular 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 control device 86 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 engine speed, when a larger amount of fuel is injected, a high pressure can be set by the control device 86 during the pilot injection in the control pressure chamber 60, so that only the first injection valve member 28 opens, and during the main injection, the pressure can can be reduced in the control pressure chamber 60 by the control device 86, so that the second injection valve member 128 also opens.

Claims

Ansprüche Expectations
1. Kraftstoffeinspritzeinrichtung für eine1. Fuel injector for one
Brennkraftmaschine mit einer Kraftstoffhochdruckpumpe (10) und einem mit dieser verbundenen Kraftstoffeinspritzventil (12) für jeden Zylinder der Brennkraftmaschine, wobei die Kraftstoffhochdruckpumpe (10) einen durch die Brennkraftmaschine in einer Hubbewegung angetriebenenInternal combustion engine with a high-pressure fuel pump (10) and a fuel injection valve (12) connected thereto for each cylinder of the internal combustion engine, the high-pressure fuel pump (10) being driven by the internal combustion engine in a stroke movement
Pumpenkolben (18) aufweist, der einen Pumpenarbeitsraum (22) begrenzt, der mit einem Druckraum (40) des Kraftstoffeinspritzventils (12) verbunden ist, wobei das Kraftstoffeinspritzventil (12) wenigstens ein erstes Einspritzventilglied (28) aufweist, durch das wenigstens eine erste Einspritzöffnung (32) gesteuert wird und das von dem im Druckraum (40) herrschenden Druck beaufschlagt gegen eine Schließkraft in einer Öffnungsrichtung (29) zur Freigabe der wenigstens einen ersten Einspritzöffnung (32) bewegbar ist, und mit einem durch einen piezoelektrischenPump piston (18) which delimits a pump work 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 member (28) through which at least one first injection opening (32) is controlled and which is acted upon by the pressure prevailing in the pressure chamber (40) against a closing force in an opening direction (29) to release the at least one first injection opening (32), and with a piezoelectric one
Aktor (84) betätigten Steuerventil (70) , durch das zumindest mittelbar eine Verbindung des Pumpenarbeitsraums (22) mit einem Entlastungsbereich (78) gesteuert wird, dadurch gekennzeichnet, daß das Kraftstoffeinspritzventil (12) ein zweites, innerhalb des hohl ausgebildeten ersten Einspritzventilglieds (28) verschiebbar geführtes Einspritzventilglied (128) aufweist, durch das wenigstens eine zweite Einspritzöffnung (132) gesteuert wird und das von dem im Druckraum (40) herrschenden Druck beaufschlagt gegen eine Schließkraft in einer Öffnungsrichtung (29) bewegbar ist, daß das zweite Einspritzventilglied (128) zumindest mittelbar von dem in einem kraftstoffgefüllten Steuerdruckraum (60) herrschenden Druck in einer Schließrichtung beaufschlagt ist und daß der im Steuerdruckraum (60) herrschende Druck abhängig von Betriebsbedingungen der Brennkraftmaschine variabel gesteuert wird.Actuator (84) actuated control valve (70), through which at least indirectly a connection of the pump work space (22) to a relief region (78) is controlled, characterized in that the fuel injection valve (12) has a second, inside the hollow first injection valve member (28 ) which has a displaceably guided injection valve member (128) through which at least one second injection opening (132) is controlled and which, when acted upon by the pressure prevailing in the pressure chamber (40), can be moved in an opening direction (29) against a closing force such that the second injection valve member (128 ) is acted upon at least indirectly by the pressure prevailing in a fuel-filled control pressure chamber (60) in a closing direction and that the pressure prevailing in the control pressure chamber (60) is variably controlled depending on the operating conditions of the internal combustion engine.
2. Kraftstoffeinspritzeinrichtung nach Anspruch 1, dadurch gekennzeichnet, daß durch den piezoelektrischen Aktor (84) der in einem Aktordruckraum (80) herrschende Druck gesteuert wird, daß das Steuerventil (70) ein Steuerventilglied (72) aufweist, das zwischen einer Schließstellung, in der der Pumpenarbeitsraum (22) vom Entlastungsbereich (78) getrennt ist, und einer Öffnungsstellung, in der der Pumpenarbeitsraum (22) vom Entlastungsbereich (78) getrennt ist, bewegbar ist, und daß das Steuerventilglied (72) durch den im Aktordruckraum (80) herrschenden Druck in einer Schließrichtung beaufschlagt ist.2. Fuel injection device according to claim 1, characterized in that the pressure prevailing in an actuator pressure chamber (80) is controlled by the piezoelectric actuator (84), that the control valve (70) has a control valve member (72) which between a closed position in which the pump work space (22) is separated from the relief area (78), and an open position in which the pump work space (22) is separated from the relief area (78) is movable, and that the control valve member (72) through that in the actuator pressure space (80) Pressure is applied in a closing direction.
3. Kraftstoffeinspritzeinrichtung nach Anspruch 2, dadurch gekennzeichnet, daß das Steuerventilglied (72) auf seiner dem Aktordruckraum (80) abgewandten Stirnseite von dem im Steuerdruckraum (60) herrschenden Druck in einer Öffnungsrichtung beaufschlagt ist.3. Fuel injection device according to claim 2, characterized in that the control valve member (72) on its end facing away from the actuator pressure chamber (80) is acted upon by the pressure prevailing in the control pressure chamber (60) in an opening direction.
4. Kraftstoffeinspritzeinrichtung nach Anspruch 2 oder 3 , dadurch gekennzeichnet, daß das Steuerventilglied (72) durch eine Rückstellfeder (82) in einer Öffnungsrichtung beaufschlagt ist.4. Fuel injection device according to claim 2 or 3, characterized in that the control valve member (72) is acted upon by a return spring (82) in an opening direction.
5. Kraftstoffeinspritzeinrichtung nach einem der Ansprüche 2 bis 4, dadurch gekennzeichnet, daß der Steuerdruckraum (60) eine Verbindung (88) mit dem Aktordruckraum (80) aufweist, in der ein zum Aktordruckraum (80) hin öffnendes Rückschlagventil (90) angeordnet ist. 5. Fuel injection device according to one of claims 2 to 4, characterized in that the control pressure chamber (60) has a connection (88) with the actuator pressure chamber (80), in which a check valve (90) opening towards the actuator pressure chamber (80) is arranged.
6. Kraftstoffeinspritzeinrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß der Steuerdruckraum (60) durch einen auf das zweite Einspritzventilglied (128) wirkenden Steuerkolben (62) begrenzt wird und daß das zweite Einspritzventilglied (128) zusätzlich durch eine sich vorzugsweise am Steuerkolben (62) abstützende Schließfeder (144) in Schließrichtung beaufschlagt ist.6. Fuel injection device according to one of claims 1 to 5, characterized in that the control pressure chamber (60) by a on the second injection valve member (128) acting control piston (62) is limited and that the second injection valve member (128) additionally by a preferably on Control piston (62) supporting closing spring (144) is acted upon in the closing direction.
7. Kraftstoffeinspritzeinrichtung nach Anspruch 4 und 6, dadurch gekennzeichnet, daß die Rückstellfeder (82) zwischen dem Steuerventilglied (72) und dem Steuerkolben (62) eingespannt ist.7. Fuel injection device according to claim 4 and 6, characterized in that the return spring (82) between the control valve member (72) and the control piston (62) is clamped.
8. Kraftstoffeinspritzeinrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß der8. Fuel injection device according to one of the preceding claims, characterized in that the
Druck im Steuerdruckraum (60) durch eine Förderpumpe (64) erzeugt wird.Pressure in the control pressure chamber (60) is generated by a feed pump (64).
9. Kraftstoffeinspritzeinrichtung nach Anspruch 8, dadurch gekennzeichnet, daß der Betrieb der Förderpumpe (64) durch eine Steuereinrichtung (86) derart gesteuert wird, daß diese den in Abhängigkeit von Betriebsbedingungen der Brennkraftmaschine variablen Druck im Steuerdruckraum (60) erzeugt .9. Fuel injection device according to claim 8, characterized in that the operation of the feed pump (64) is controlled by a control device (86) such that it generates the pressure in the control pressure chamber (60) as a function of operating conditions of the internal combustion engine.
10. Kraftstoffeinspritzeinrichtung nach Anspruch 8, dadurch gekennzeichnet, daß der Druck im Steuerdruckraum (60) durch ein von einer Steuereinrichtung (86) angesteuertes Entlastungsventil (66) in Abhängigkeit von Betriebsbedingungen der Brennkraftmaschine variabel eingestellt wird.10. Fuel injection device according to claim 8, characterized in that the pressure in the control pressure chamber (60) by a control device (86) controlled relief valve (66) is variably set depending on the operating conditions of the internal combustion engine.
11. Kraftstoffeinspritzeinrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß bei geringer Last und/oder Drehzahl der Brennkraftmaschine im Steuerdruckraum (60) ein hoher Druck eingestellt wird, so daß das zweite Einspritzventilglied (128) in seiner geschlossenen Stellung bleibt und nur das erste Einspritzventilglied (28) öffnet und die wenigstens eine erste Einspritzöffnung (32) freigibt und daß bei hoher Last und/oder Drehzahl der Brennkraftmaschine im Steuerdruckraum (60) ein geringer Druck eingestellt wird, so daß zusätzlich auch das zweite Einspritzventilglied (128) öffnet und die wenigstens eine zweite Einspritzöffnung (132) freigibt.11. Fuel injection device according to one of the preceding claims, characterized in that at low load and / or speed of the internal combustion engine in the control pressure chamber (60) a high pressure is set, so that the second injection valve member (128) remains in its closed position and only the first injection valve member (28) opens and the at least one first injection opening (32) opens and that at high load and / or speed of the internal combustion engine in the control pressure chamber (60) a low pressure is set so that the second injection valve member (128) also opens and the at least one second injection opening (132) is opened.
12. Kraftstoffeinspritzeinrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß zu Beginn eines Einspritzzyklus im Steuerdruckraum (60) ein hoher Druck eingestellt wird, so daß das zweite Einspritzventilglied (128) in seiner geschlossenen Stellung bleibt und nur das erste Einspritzventilglied (28) öffnet und die wenigstens eine erste Einspritzöffnung (32) freigibt, und daß im weiteren Verlauf des Einspritzzyklus im Steuerdruckraum (60) ein geringer Druck eingestellt wird, so daß zusätzlich auch das zweite Einspritzventilglied (128) öffnet und die wenigstens eine zweite Einspritzöffnung (132) freigibt.12. Fuel injection device according to one of the preceding claims, characterized in that at the beginning of an injection cycle in the control pressure chamber (60) a high pressure is set so that the second injection valve member (128) remains in its closed position and only the first injection valve member (28) opens and the at least one first injection opening (32) opens, and that in the further course of the injection cycle a low pressure is set in the control pressure chamber (60), so that the second injection valve member (128) also opens and the at least one second injection opening (132) opens ,
13. Kraftstoffeinspritzeinrichtung nach Anspruch 12, dadurch gekennzeichnet, daß der Einspritzzyklus mit einer Voreinspritzung einer geringen Kraftstoffmenge beginnt, während der im Steuerdruckraum (60) ein hoher Druck eingestellt wird, und daß der Einspritzzyklus sich mit einer Haupteinspritzung einer größeren Kraftstoffmenge fortsetzt, während der im Steuerdruckraum (60) ein geringer Druck eingestellt wird.13. Fuel injection device according to claim 12, characterized in that the injection cycle begins with a pre-injection of a small amount of fuel, during which a high pressure is set in the control pressure chamber (60), and that the injection cycle continues with a main injection of a larger amount of fuel, during which Control pressure chamber (60) a low pressure is set.
14. Kraftstoffeinspritzeinrichtung nach Anspruch 13, dadurch gekennzeichnet, daß erst während des Verlaufs der Haupteinspritzung ein geringer Druck im Steuerdruckraum (60) eingestellt wird. 14. Fuel injection device according to claim 13, characterized in that only a low pressure in the control pressure chamber (60) is set 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)

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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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Also Published As

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WO2003054374A1 (en) 2003-07-03
CN1492966A (en) 2004-04-28
CN100379975C (en) 2008-04-09
DE10162651A1 (en) 2003-09-04
PL362307A1 (en) 2004-10-18
US6896208B2 (en) 2005-05-24
DE50212491D1 (en) 2008-08-21
US20040144364A1 (en) 2004-07-29
JP2005513331A (en) 2005-05-12
EP1458970B1 (en) 2008-07-09
KR20040067853A (en) 2004-07-30

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