EP1241347B1 - Fuel injection system for internal combustion engines - Google Patents

Fuel injection system for internal combustion engines Download PDF

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Publication number
EP1241347B1
EP1241347B1 EP02004726A EP02004726A EP1241347B1 EP 1241347 B1 EP1241347 B1 EP 1241347B1 EP 02004726 A EP02004726 A EP 02004726A EP 02004726 A EP02004726 A EP 02004726A EP 1241347 B1 EP1241347 B1 EP 1241347B1
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EP
European Patent Office
Prior art keywords
pressure
valve
space
fuel
control
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
EP02004726A
Other languages
German (de)
French (fr)
Other versions
EP1241347A3 (en
EP1241347A2 (en
Inventor
Nestor Rodriguez-Amaya
Roger Potschin
Juergen Dr. Gruen
Ulrich Dr. Projahn
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Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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Filing date
Publication date
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Publication of EP1241347A2 publication Critical patent/EP1241347A2/en
Publication of EP1241347A3 publication Critical patent/EP1241347A3/en
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Publication of EP1241347B1 publication Critical patent/EP1241347B1/en
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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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/04—Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
    • 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
    • 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
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/06—Pumps peculiar thereto
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/12—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship providing a continuous cyclic delivery with variable 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
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing 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
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • 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
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0003—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure
    • F02M63/0007—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure using electrically actuated 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
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/40—Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator

Definitions

  • the invention relates to a fuel injection device for internal combustion engines according to the preamble of claim 1.
  • Such a fuel injection device is known from EP 0 957 261 A1.
  • This fuel injector includes a fuel pump for each cylinder of the internal combustion engine having a pump piston driven by the engine in a reciprocating motion and defining a pump working space to which fuel is supplied from a fuel reservoir.
  • the pump working space is connected to a fuel injection valve having an injection valve member through which at least one injection port is controlled and which is movable by the pressure prevailing in the pump working space against a closing force in the opening direction.
  • a first electrically controlled control valve is provided, by which a connection of the pump working chamber to the fuel reservoir is controlled as a diversion chamber.
  • a second electrically controlled control valve is provided by which the control pressure prevailing in a control pressure chamber is controlled, by which the injection valve member is at least indirectly acted upon in the closing direction.
  • JP-06093936A discloses a fuel injector in which a fuel pump is provided which has a pump piston indirectly driven by the engine in a reciprocating motion, which limits a pump working space to which fuel is supplied from a fuel reservoir.
  • the pump working space is connected to a high-pressure accumulator, to which in turn at least one fuel injection valve is connected.
  • the fuel injection valve has an injection valve member, is controlled by the at least one injection port and which is movable by the pressure generated in the high pressure accumulator and thus in the pump working space against a closing force in an opening direction.
  • the Abêtraum is a low-pressure accumulator in which a pressure is maintained, which is increased relative to the prevailing pressure in the fuel tank, but is less than the pressure prevailing in the high-pressure accumulator pressure.
  • the low-pressure accumulator is also connectable to the fuel injection valve and fuel can be removed from the low-pressure accumulator for a pilot injection.
  • the pressure in the low-pressure accumulator is determined by the electrically controlled valve, which controls the connection of the pump working chamber with the low-pressure accumulator. In this case, no independent influence on the pressure in the low-pressure accumulator and the control of the connection of the pump working chamber with the low-pressure accumulator is possible.
  • the fuel injection device with the features of claim 1 has the advantage that the pressure prevailing in the discharge chamber pressure accumulator held in a simple manner by means of the pressure relief valve at least approximately constant or can be variably adjusted by means of the third electrically controlled control valve, regardless of the control of Connection of the pump working space by means of the first electrically controlled control valve.
  • FIG. 1 shows a fuel injection device for an internal combustion engine in a schematic representation according to a first 3 shows a profile of a pressure at injection openings of a fuel injection valve of the fuel injection device, Figure 4 shows a detail of a modified embodiment of the fuel injection device and Figure 5 shows a detail of a further modified embodiment of Krafscherin mousse sensible.
  • FIGS. 1, 2, 4 and 5 show a fuel injection device for an internal combustion engine of a motor vehicle.
  • the internal combustion engine is preferably a self-igniting internal combustion engine.
  • the fuel injection device is preferably designed as a so-called pump-line-nozzle system and has for each cylinder of the internal combustion engine in each case a fuel pump 10, a fuel injection valve 12 and a fuel injection valve 12 to the fuel pump 10 connecting line 14.
  • the fuel pump 10 has a tightly guided in a cylinder 16 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 by means of a feed pump 21 fuel from a fuel tank 24 of the motor vehicle. Between the feed pump 21 and the pump working chamber 22, a check valve 23 opening to the pump working chamber 22 is arranged. The check valve 23 may also be omitted, in which case a control edge of the pump piston 18, the laxative from the cylinder 16 connection of the pump working chamber 22 with the fuel tank 24 and is controlled. In line 14, a further check valve 25 opening from the pump working chamber 22 is arranged. The delivery line from the feed pump 21 opens between the pump working chamber 22 and the further check valve 25th
  • the fuel injection valve 12 is arranged separately from the fuel pump 10 and connected via the line 14 to the pump working chamber 22.
  • the fuel injection valve 12 has a valve body 26, which may be formed in several parts, in which an injection valve member 28 is guided longitudinally displaceably in a bore 30.
  • the valve body 26 At its end region facing the combustion chamber of the cylinder of the internal combustion engine, the valve body 26 has at least one, preferably a plurality of injection openings 32.
  • the 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 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 injection valve member 28.
  • the injection valve member 28 has at the level of the pressure chamber 40 by a cross-sectional reduction on a pressure shoulder 42.
  • a prestressed closing spring 44 At the end remote from the combustion chamber of the injection valve member 28 engages a prestressed closing spring 44, through which the injection valve member 28 is pressed to the valve seat 36.
  • the closing spring 44 is arranged in a spring chamber 46 of the valve body 26, the adjoins the bore 30.
  • a further bore 48 in which a piston 50 is guided tightly, which is connected to the injection valve member 28.
  • the piston 50 defines with its end facing away from the injection valve member 28 a control pressure chamber 52 in the valve body 26.
  • a channel 54 is formed, in which the line 14 to the fuel pump 10 opens and which opens into the pressure chamber 40.
  • FIG. 1 shows the fuel injection device according to a first exemplary embodiment. From the channel 54, a connection 56 branches off to the control pressure chamber 52.
  • the fuel injection device has a first control valve 60, which is arranged close to the fuel pump 10 and which can be integrated into the fuel pump 10, for example.
  • a connection 59 of the pump working chamber 22 of the fuel pump 10 is controlled with a discharge chamber 62 designed as a pressure accumulator.
  • the connection 59 branches off the line 14 downstream of the check valve 25.
  • the pressure accumulator 62 a pressure which is increased in relation to the pressure in the fuel reservoir 24 is maintained.
  • the accumulator 62 is connected via a pressure relief valve 64 with a discharge chamber, which is for example the fuel tank 24.
  • the pressure in the pressure accumulator 62 at least kept approximately constant by this opens upon reaching the set pressure and fuel can flow from the accumulator 62 into the fuel tank 24. If the internal combustion engine has a plurality of cylinders, then a common pressure accumulator 62 can be used for the fuel injectors of all cylinders.
  • the first control valve 60 is electrically controllable and has an actuator 61, which may be an electromagnet or a piezoelectric actuator, which is electrically controlled and through which a valve member of the control valve 60 is movable.
  • the first control valve 60 may be pressure compensated or non-pressure balanced.
  • the first control valve 60 is designed as a 2/2-way valve and through this the connection 59 is opened to the accumulator 62 in a first switching position and in a second switching position, the connection 59 is disconnected to the pressure accumulator 62.
  • the control valve 60 is controlled by an electric control device 66 as a function of operating parameters of the internal combustion engine.
  • a second control valve 68 is provided, through which a connection 70 of the control pressure chamber 52 with a discharge chamber, such as the fuel tank 24, is controlled.
  • the second control valve 68 is electrically controllable and has an actuator 69, which may be an electromagnet or a piezoelectric actuator, which is electrically controlled and through which a valve member of the control valve 68 is movable.
  • the second control valve 68 is preferably formed pressure balanced, but can not be pressure balanced.
  • the second control valve 68 is designed as a 2/2-way valve, through which the connection 70 of the control pressure chamber 52 is opened with the fuel tank 24 in a first switching position and separated by the connection 70 of the control pressure chamber 52 with the fuel tank 24 in a second switching position is.
  • a throttle body 58 is provided in the connection 59 of the control pressure chamber 52 with the channel 54 and in the connection 70 of the control pressure chamber 52 to the fuel tank 24 is between the Control pressure chamber 52 and the second control valve 68, a further throttle point 71 is provided.
  • the second control valve 68 is also controlled by the controller 66.
  • the control of the control valves 60,68 by the control device 66 is dependent on operating parameters of the internal combustion engine, such as speed, load and temperature.
  • the pressure prevailing in the pump working chamber 22 pressure acts via the line 14 and the channel 54 in the valve body 26 in the pressure chamber 40.
  • the second control valve 68 is opened by the control device 66, so that in the control pressure chamber 52 in spite of its connection 56 with the channel 54 no high pressure can build, but this is reduced to the fuel tank 24 out.
  • By the throttle points 58 and 71 it is achieved that from the channel 54 only a small amount of fuel in the Fuel tank 24 can drain.
  • the injection valve member 28 When the pressure prevailing in the pressure chamber 40 has reached such a height that it exerts on the injection valve member 28 on the injection valve member 28 in the opening direction 29 acting force which is greater than the force of the closing spring 44, the injection valve member 28 lifts with its sealing surface 34th from the valve seat 36 and fuel is injected through the injection openings 32 in the combustion chamber of the cylinder of the internal combustion engine.
  • the opening pressure of the fuel injection valve 12 is only dependent on the force of the closing spring 44 because of the opened second control valve 68.
  • the pressure curve during the injection is determined by the profile of the cam 20.
  • the first control valve 60 is opened, so that the connection 59 is open to the pressure accumulator 62.
  • the pressure level at which the pilot injection takes place is determined by the pressure set in the pressure accumulator 62 by means of the pressure limiting valve 64.
  • the opening pressure of the fuel injection valve 12 is lower than the pressure set in the pressure accumulator 62 by the pressure limiting valve 64.
  • FIG. 3 shows the course of the pressure p at the injection openings 32 of the fuel injection valve 12 over the time t during an injection cycle.
  • the pilot injection corresponds to an injection phase designated by I in FIG.
  • the second control valve 68 is closed by the control device 66, so that the control pressure chamber 52 is separated from the fuel tank 24 and builds up in the control pressure chamber 52 via the connection 56 with the channel 54 pressure.
  • the Force of the closing spring 44 generates supporting force, so that the injection valve member 28 moves against its opening direction 29 and comes with its sealing surface 34 on the valve seat 36 to the plant and the injection is terminated.
  • the second control valve 68 is opened by the control device 66, so that the control pressure chamber 52 is relieved again and the fuel injection valve 12 opens.
  • the first control valve 60 may be closed at the beginning of the main injection, so that the connection 59 is separated to the pressure accumulator 62 and in the line 14 and the pressure chamber 40 of the fuel injection valve 12, a pressure build-up corresponding to the profile of the cam 20.
  • the first control valve 60 remains initially still open, so that only a pressure corresponding to that by the pressure relief valve 64 in the accumulator 62 due to the open connection 59 to the accumulator 62 in the line 14 and the pressure chamber 40 of the fuel injection valve set pressure can build.
  • the main injection then starts at a pressure level as well as the pre-injection has occurred.
  • the main injection begins with the first control valve 60 closed at a higher pressure level than initially opened first control valve 60. Subsequently, the first control valve 60 is closed by the controller 66, and the main injection is carried out at a pressure as in accordance with the profile of the cam 20 in the pump working space 22 is generated. It may also be provided that initially the first control valve 60 is closed, but the second control valve 68 still remains closed, so that no injection takes place. The second control valve 68 is then opened only delayed, whereby the start of the main injection is delayed and also the Main injection starts at a higher pressure.
  • the main injection corresponds in Figure 3 to an injection phase denoted by II, wherein the pressure curve is shown in solid line in the event that the first control valve 60 is opened at the beginning, and the pressure curve is shown in dashed line in the event that the first control valve 60 is already closed at the beginning.
  • the second control valve 68 is closed by the control device 66, so that the control pressure chamber 52 is separated from the fuel tank 24 and in the control pressure chamber 52 by its connection with the channel 54 and thus the pump working chamber 22 builds high pressure, through which the fuel injection valve 12th is closed.
  • the first control valve 60 remains closed, so that the connection 59 is disconnected to the accumulator 62.
  • the second control valve 68 is opened again by the control device 66, so that the control pressure chamber 52 is relieved again and the fuel injection valve 12 opens.
  • the post-injection is carried out with a pressure curve corresponding to the profile of the cam 20.
  • the post-injection the first control valve 60 is opened, so that the post-injection takes place only with the pressure level corresponding to the pressure accumulator 62.
  • the second control valve 68 is closed by the control device 66 and / or the first control valve 60 is opened by the control device 66.
  • the post-injection corresponds to an injection phase designated III in FIG.
  • the second control valve 68 may be closed or opened.
  • the first Control valve 60 is opened, so that the connection 59 is open to the pressure accumulator 62.
  • the pressure drops to the pressure in the fuel tank 24 or the pressure generated by the feed pump 21.
  • the pump chamber 22 is separated by the check valve 25 from the line 14, wherein in the conduit 14, in the channel 54 and in the pressure chamber 40 of the fuel injection valve 12, a pressure corresponding to the predetermined by the pressure relief valve 64 in the accumulator 62 pressure.
  • FIG. 2 shows the fuel injection device according to a second embodiment, in which the basic structure is the same as in the first embodiment explained above, but the control of the pressure in the pressure accumulator 62 is modified.
  • a third control valve 74 is provided instead of the pressure limiting valve 64.
  • the third control valve 74 is electrically controllable and has an actuator 75, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 74 is movable.
  • the third control valve 74 is designed as a 2/2-way valve and through this a connection 76 of the pressure accumulator 62 is opened with the fuel tank 24 as a relief space in a first switching position and in a second switching position, the connection 76 is disconnected to the fuel tank 24.
  • the third control valve 74 is likewise controlled by the control device 66.
  • a pressure sensor 78 is provided, by which the pressure in the pressure accumulator 62 is detected and which is connected to the control device 66.
  • the pressure in the accumulator 62 are increased and can be adjusted variably depending on operating parameters of the internal combustion engine, so that, correspondingly, the pressure at which the pilot injection takes place and the main injection begins, is variable. Even the pressure in the line 14 and the pressure chamber 40 of the fuel injection valve 12 with unloaded pump working chamber 22 can be variably adjusted. Otherwise, the operation of the fuel injection device according to the second embodiment is the same as in the first embodiment
  • FIG. 4 shows a further embodiment of the fuel injection device, in which the basic structure is essentially the same as in the first or second embodiment, but the arrangement and design of the second control valve 168 is modified.
  • the second control valve 168 is electrically controllable and has an actuator 169, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 168 is movable.
  • the second control valve 168 is arranged in the connection 56 of the control pressure chamber 52 with the channel 54.
  • the second control valve 168 is designed as a 3/2-way valve, through which the connection 56 of the control pressure chamber 52 with the channel 54 and thus the pump working chamber 22 is opened and the control pressure chamber 52 is separated from the fuel tank 24 as a relief space in a first switching position. In a second switching position of the second control valve 168, the control pressure chamber 52 is connected to the fuel tank 24 as a relief space and the connection 56 to the channel 54 and thus to the pump working chamber 22 is disconnected.
  • the second control valve 168 is brought by the control device 66 in its second switching position in which the control pressure chamber 52 is relieved in the fuel tank 24, and to close the fuel injection valve 12, the second control valve 168 is brought into its first switching position in which the control pressure chamber 52 with the channel 54 is connected. Otherwise, the operation of the fuel injection device according to this modified embodiment is the same as in the first or second embodiment.
  • FIG. 5 shows a further embodiment of the fuel injection device, in which the basic structure is essentially the same as in the first or second embodiment, but the arrangement and design of the second control valve 268 is modified.
  • the second control valve 268 is electrically controllable and has an actuator 269, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 268 is movable.
  • the line 14 is connected to the second control valve 268 and on the other hand, the channel 54 is connected to the pressure chamber 40 and the connection 56 to the control pressure chamber 52 to this.
  • the second control valve 268 is designed as a 3/2-way valve, through which the connection 56 of the control pressure chamber 52 is opened with the channel 54 in a first switching position and the channel 54 is separated from the line 14 and thus from the pump working chamber 22. In a second switching position of the second control valve 268 is separated by this the control pressure chamber 52 from the channel 54 and the channel 54 is connected to the conduit 14 and thus the pump working chamber 22.
  • the control pressure chamber 52 has a connection 270 with the fuel tank 24 as a relief space in which a fuel tank 24 to open Check valve 272 is arranged and also a throttle point may be provided.
  • the second control valve 268 is brought by the control device 66 in its second switching position in which the control pressure chamber 52 is separated from the channel 54 and the channel 54 is connected to the line 14 so that the fuel pump of the 10th generated pressure in the pressure chamber 40 of the fuel injection valve 12 passes, the control pressure chamber 52 is relieved in the fuel tank 24.
  • the second control valve 268 is brought into its first switching position, in which the control pressure chamber 52 is connected to the channel 54, the channel 54, however, is separated from the line 14.
  • the pressure prevailing in the pressure chamber 40 of the fuel injection valve 12 also acts in the control pressure chamber 52, whereby the fuel injection valve 12 is closed. Otherwise, the operation of the fuel injection device according to this modified embodiment is the same as in the first or second embodiment.

Description

Stand der TechnikState of the art

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

Eine solche Kraftstoffeinspritzeinrichtung ist durch die EP 0 957 261 A1 bekannt. Diese Kraftstoffeinspritzeinrichtung weist eine Kraftstoffpumpe für jeden Zylinder der Brennkraftmaschine auf, die einen durch die Brennkraftmaschine in einer Hubbewegung angetriebenen Pumpenkolben aufweist, der einen Pumpenarbeitsraum begrenzt, dem Kraftstoff aus einem Kraftstoffvorratsbehälter zugeführt wird. Der Pumpenarbeitsraum ist mit einem Kraftstoffeinspritzventil verbunden, das ein Einspritzventilglied aufweist, durch das wenigstens eine Einspritzöffnung gesteuert wird und das durch den im Pumpenarbeitsraum herrschenden Druck gegen eine Schließkraft in Öffnungsrichtung bewegbar ist. Es ist ein erstes elektrisch gesteuertes Steuerventil vorgesehen, durch das eine Verbindung des Pumpenarbeitsraums mit dem Kraftstoffvorratsbehälter als Absteuerraum gesteuert wird. Es ist außerdem ein zweites elektrisch gesteuertes Steuerventil vorgesehen, durch das der in einem Steuerdruckraum herrschende Steuerdruck gesteuert wird, durch den das Einspritzventilglied zumindest mittelbar in Schließrichtung beaufschlagt ist. Nachteilig bei dieser bekannten Kraftstoffeinspritzeinrichtung ist, daß durch die Verwendung des drucklosen Kraftstoffvorratsbehälters als Absteuerraum der Druck im Pumpenarbeitsraum und in den mit diesem verbundenen Bereichen der Kraftstoffeinspritzeinrichtung bei der Verbindung mit dem Entlastungsraum stark abfällt und somit die Gefahr von Kavitation besteht. Außerdem ist der Wirkungsgrad der Kraftstoffeinspritzeinrichtung hierdurch nicht optimal.Such a fuel injection device is known from EP 0 957 261 A1. This fuel injector includes a fuel pump for each cylinder of the internal combustion engine having a pump piston driven by the engine in a reciprocating motion and defining a pump working space to which fuel is supplied from a fuel reservoir. The pump working space is connected to a fuel injection valve having an injection valve member through which at least one injection port is controlled and which is movable by the pressure prevailing in the pump working space against a closing force in the opening direction. A first electrically controlled control valve is provided, by which a connection of the pump working chamber to the fuel reservoir is controlled as a diversion chamber. In addition, a second electrically controlled control valve is provided by which the control pressure prevailing in a control pressure chamber is controlled, by which the injection valve member is at least indirectly acted upon in the closing direction. A disadvantage of this known fuel injection device is that by the use of the non-pressurized fuel reservoir as Absteuerraum the pressure in the pump working space and in the associated with this areas of the fuel injector in the connection with the discharge space drops sharply and thus there is the danger of cavitation. In addition, the efficiency of the fuel injector is not optimal thereby.

Durch die JP-06093936A ist außerdem eine Kraftstoffeinspritzeinrichtung bekannt, bei der eine Kraftstoffpumpe vorgesehen ist, die einen mittelbar durch die Brennkraftmaschine in einer Hubbewegung angetriebenen Pumpenkolben aufweist, der einen Pumpenarbeitsraum begrenzt, dem Kraftstoff aus einem Kraftstoffvorratsbehälter zugeführt wird. Der Pumpenarbeitsraum ist mit einem Hochdruckspeicher verbunden, mit dem wiederum wenigstens ein Kraftstoffeinspritzventil verbunden ist. Das Kraftstoffeinspritzventil weist ein Einspritzventilglied auf, durch das wenigstens eine Einspritzöffnung gesteuert wird und das durch den im Hochdruckspeicher und damit im Pumpenarbeitsraum erzeugten Druck gegen eine Schließkraft in einer Öffnungsrichtung bewegbar ist. Es ist ein erstes elektrisch gesteuertes Steuerventil vorgesehen, durch das eine Verbindung des Pumpenarbeitsraums mit einem Absteuerraum gesteuert wird und es ist ein zweites elektrisch gesteuertes Steuerventil vorgesehen, durch das der in einem Steuerdruckraum des Kraftstoffeinspritzventils herrschende Druck gesteuert wird, durch den das Einspritzventilglied zumindest mittelbar in Schließrichtung beaufschlagt ist. Der Absteuerraum ist ein Niederdruckspeicher, in dem ein Druck aufrechterhalten wird, der gegenüber dem im Kraftstoffvorratsbehälter herrschenden Druck erhöht ist, jedoch geringer ist als der im Hochdruckspeicher herrschende Druck. Der Niederdruckspeicher ist dabei ebenfalls mit dem Kraftstoffeinspritzventil verbindbar und aus dem Niederdruckspeicher kann Kraftstoff für eine Voreinspritzung entnommen werden. Der Druck im Niederdruckspeicher wird durch das elektrisch gesteuerte Ventil bestimmt, das die Verbindung des Pumpenarbeitsraums mit dem Niederdrcukspeicher steuert. Hierbei ist keine unabhängige Beeinflussung des Drucks im Niederdruckspeicher und der Steuerung der Verbindung des Pumpenarbeitsraums mit dem Niederdruckspeicher möglich.Moreover, JP-06093936A discloses a fuel injector in which a fuel pump is provided which has a pump piston indirectly driven by the engine in a reciprocating motion, which limits a pump working space to which fuel is supplied from a fuel reservoir. The pump working space is connected to a high-pressure accumulator, to which in turn at least one fuel injection valve is connected. The fuel injection valve has an injection valve member, is controlled by the at least one injection port and which is movable by the pressure generated in the high pressure accumulator and thus in the pump working space against a closing force in an opening direction. It is a first electrically controlled control valve is provided, through which a connection of the pump chamber is controlled with a Absteuerraum and there is a second electrically controlled control valve is provided, which controls the pressure prevailing in a control pressure chamber of the fuel injection valve pressure through which the injection valve member at least indirectly in Closing direction is acted upon. The Absteuerraum is a low-pressure accumulator in which a pressure is maintained, which is increased relative to the prevailing pressure in the fuel tank, but is less than the pressure prevailing in the high-pressure accumulator pressure. The low-pressure accumulator is also connectable to the fuel injection valve and fuel can be removed from the low-pressure accumulator for a pilot injection. The pressure in the low-pressure accumulator is determined by the electrically controlled valve, which controls the connection of the pump working chamber with the low-pressure accumulator. In this case, no independent influence on the pressure in the low-pressure accumulator and the control of the connection of the pump working chamber with the low-pressure accumulator is possible.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Kraftstoffeinspritzeinrichtung mit den Merkmalen gemäß Anspruch 1 hat demgegenüber den Vorteil, dass der im als Absteuerraum vorgesehenen Druckspeicher herrschende Druck auf einfache Weise mittels des Druckbegrenzungsventils zumindest annähernd konstant gehalten oder mittels des dritten elektrisch gesteuerten Steuerventils variabel eingestellt werden kann, unabhängig von der Steuerung der Verbindung des Pumpenarbeitsraums mittels des ersten elektrisch gesteuerten Steuerventils.The fuel injection device according to the invention with the features of claim 1 has the advantage that the pressure prevailing in the discharge chamber pressure accumulator held in a simple manner by means of the pressure relief valve at least approximately constant or can be variably adjusted by means of the third electrically controlled control valve, regardless of the control of Connection of the pump working space by means of the first electrically controlled control valve.

In den abhängigen Ansprüchen sind vorteilhafte Ausgestaltungen und Weiterbildungen der erfindungsgemäßen Kraftstoffeinspritzeinrichtung angegeben.In the dependent claims advantageous refinements and developments of the fuel injection device according to the invention are given.

Zeichnungdrawing

Mehrere Ausführungsbeispiele der Erfindung sind in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eine Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine in schematischer Darstellung gemäß einem ersten Ausführungsbeispiel, Figur 2 die Kraftstoffeinspritzeinrichtung gemäß einem zweiten Ausführungsbeispiel, Figur 3 einen Verlauf eines Druckes an Einspritzöffnungen eines Kraftstoffeinspritzventils der Kraftstoffeinspritzeinrichtung, Figur 4 ausschnittsweise eine modifizierte Ausführung der Kraftstoffeinspritzeinrichtung und Figur 5 ausschnittsweise eine weitere modifizierte Ausführung der Krafstoffeinspritzeinrichtung.Several embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. 1 shows a fuel injection device for an internal combustion engine in a schematic representation according to a first 3 shows a profile of a pressure at injection openings of a fuel injection valve of the fuel injection device, Figure 4 shows a detail of a modified embodiment of the fuel injection device and Figure 5 shows a detail of a further modified embodiment of Krafstoffeinspritzeinrichtung.

Beschreibung der AusführungsbeispieleDescription of the embodiments

In den Figuren 1,2,4 und 5 ist eine Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine eines Kraftfahrzeugs dargestellt. Die Brennkraftmaschine ist vorzugsweise eine selbstzündende Brennkraftmaschine. Die Kraftstoffeinspritzeinrichtung ist vorzugsweise als sogenanntes Pumpe-Leitung-Düse-System ausgebildet und weist für jeden Zylinder der Brennkraftmaschine jeweils eine Kraftstoffpumpe 10, ein Kraftstoffeinspritzventil 12 und eine das Kraftstoffeinspritzventil 12 mit der Kraftstoffpumpe 10 verbindende Leitung 14 auf. Die Kraftstoffpumpe 10 weist einen in einem Zylinder 16 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 mittels einer Förderpumpe 21 Kraftstoff aus einem Kraftstoffvorratsbehälter 24 des Kraftfahrzeugs zugeführt. Zwischen der Förderpumpe 21 und dem Pumpenarbeitsraum 22 ist ein zum Pumpenarbeitsraum 22 öffnendes Rückschlagventil 23 angeordnet. Das Rückschlagventil 23 kann auch entfallen, wobei dann durch eine Steuerkante des Pumpenkolbens 18 die vom Zylinder 16 abführende Verbindung des Pumpenarbeitsraums 22 mit dem Kraftstoffvorratsbehälter 24 auf- und zugesteuert wird. In der Leitung 14 ist ein aus dem Pumpenarbeitsraum 22 öffnendes weiteres Rückschlagventil 25 angeordnet. Die Förderleitung von der Förderpumpe 21 mündet zwischen dem Pumpenarbeitsraum 22 und dem weiteren Rückschlagventil 25.FIGS. 1, 2, 4 and 5 show a fuel injection device for an internal combustion engine of a motor vehicle. The internal combustion engine is preferably a self-igniting internal combustion engine. The fuel injection device is preferably designed as a so-called pump-line-nozzle system and has for each cylinder of the internal combustion engine in each case a fuel pump 10, a fuel injection valve 12 and a fuel injection valve 12 to the fuel pump 10 connecting line 14. The fuel pump 10 has a tightly guided in a cylinder 16 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 by means of a feed pump 21 fuel from a fuel tank 24 of the motor vehicle. Between the feed pump 21 and the pump working chamber 22, a check valve 23 opening to the pump working chamber 22 is arranged. The check valve 23 may also be omitted, in which case a control edge of the pump piston 18, the laxative from the cylinder 16 connection of the pump working chamber 22 with the fuel tank 24 and is controlled. In line 14, a further check valve 25 opening from the pump working chamber 22 is arranged. The delivery line from the feed pump 21 opens between the pump working chamber 22 and the further check valve 25th

Das Kraftstoffeinspritzventil 12 ist getrennt von der Kraftstoffpumpe 10 angeordnet und über die Leitung 14 mit dem Pumpenarbeitsraum 22 verbunden. Das Kraftstoffeinspritzventil 12 weist einen Ventilkörper 26 auf, der mehrteilig ausgebildet sein kann, in dem ein Einspritzventilglied 28 in einer Bohrung 30 längsverschiebbar geführt ist. Der Ventilkörper 26 weist an seinem dem Brennraum des Zylinders der Brennkraftmaschine zugewandten Endbereich wenigstens eine, vorzugsweise mehrere Einspritzöffnungen 32 auf. Das 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 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 Einspritzventilglied 28 umgebenden Druckraum 40 übergeht. Das Einspritzventilglied 28 weist auf Höhe des Druckraums 40 durch eine Querschnittsverringerung eine Druckschulter 42 auf. Am dem Brennraum abgewandten Ende des Einspritzventilglieds 28 greift eine vorgespannte Schließfeder 44 an, durch die das Einspritzventilglied 28 zum Ventilsitz 36 hin gedrückt wird. Die Schließfeder 44 ist in einem Federraum 46 des Ventilkörpers 26 angeordnet, der sich an die Bohrung 30 anschließt. An den Federraum 46 schließt sich an dessen der Bohrung 30 abgewandtem Ende im Ventilkörper 26 eine weitere Bohrung 48 an, in der ein Kolben 50 dicht geführt ist, der mit dem Einspritzventilglied 28 verbunden ist. Der Kolben 50 begrenzt mit seiner dem Einspritzventilglied 28 abgewandten Stirnseite einen Steuerdruckraum 52 im Ventilkörper 26. Im Ventilkörper 26 ist ein Kanal 54 ausgebildet, in den die Leitung 14 zur Kraftstoffpumpe 10 mündet und der in den Druckraum 40 mündet.The fuel injection valve 12 is arranged separately from the fuel pump 10 and connected via the line 14 to the pump working chamber 22. The fuel injection valve 12 has a valve body 26, which may be formed in several parts, in which an injection valve member 28 is guided longitudinally displaceably in a bore 30. At its end region facing the combustion chamber of the cylinder of the internal combustion engine, the valve body 26 has at least one, preferably a plurality of injection openings 32. The 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 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 injection valve member 28. The 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 injection valve member 28 engages a prestressed closing spring 44, through which the injection valve member 28 is pressed to the valve seat 36. The closing spring 44 is arranged in a spring chamber 46 of the valve body 26, the adjoins the bore 30. To the spring chamber 46 connects at its end facing away from the bore 30 in the valve body 26, a further bore 48, in which a piston 50 is guided tightly, which is connected to the injection valve member 28. The piston 50 defines with its end facing away from the injection valve member 28 a control pressure chamber 52 in the valve body 26. In the valve body 26, a channel 54 is formed, in which the line 14 to the fuel pump 10 opens and which opens into the pressure chamber 40.

In Figur 1 ist die Kraftstoffeinspritzeinrichtung gemäß einem ersten Ausführungsbeispiel dargestellt. Vom Kanal 54 zweigt eine Verbindung 56 zum Steuerdruckraum 52 ab. Die Kraftstoffeinspritzeinrichtung weist ein nahe der Kraftstoffpumpe 10 angeordnetes erstes Steuerventil 60 auf, das beispielsweise in die Kraftstoffpumpe 10 integriert sein kann. Durch das erste Steuerventil 60 wird eine Verbindung 59 des Pumpenarbeitsraums 22 der Kraftstoffpumpe 10 mit einem als Druckspeicher ausgebildeten Absteuerraum 62 gesteuert. Die Verbindung 59 zweigt stromabwärts des Rückschlagventils 25 von der Leitung 14 ab. Im Druckspeicher 62 wird ein gegenüber dem Druck im Kraftstoffvorratsbehälter 24 erhöhter Druck aufrechterhalten. Der Druckspeicher 62 ist über ein Druckbegrenzungsventil 64 mit einem Entlastungsraum verbunden, der beispielsweise der Kraftstoffvorratsbehälter 24 ist. Durch das Druckbegrenzungsventil 64 wird der Druck im Druckspeicher 62 zumindet annähernd konstant gehalten, indem dieses bei Erreichen des eingestellten Druckes öffnet und Kraftstoff aus dem Druckspeicher 62 in den Kraftstoffvorratsbehälter 24 abfließen kann. Wenn die Brennkraftmaschine mehrere Zylinder aufweist, so kann für die Kraftstoffeinspritzeinrichtungen aller Zylinder ein gemeinsamer Druckspeicher 62 verwendet werden.FIG. 1 shows the fuel injection device according to a first exemplary embodiment. From the channel 54, a connection 56 branches off to the control pressure chamber 52. The fuel injection device has a first control valve 60, which is arranged close to the fuel pump 10 and which can be integrated into the fuel pump 10, for example. By the first control valve 60, a connection 59 of the pump working chamber 22 of the fuel pump 10 is controlled with a discharge chamber 62 designed as a pressure accumulator. The connection 59 branches off the line 14 downstream of the check valve 25. In the pressure accumulator 62, a pressure which is increased in relation to the pressure in the fuel reservoir 24 is maintained. The accumulator 62 is connected via a pressure relief valve 64 with a discharge chamber, which is for example the fuel tank 24. By the pressure relief valve 64, the pressure in the pressure accumulator 62 at least kept approximately constant by this opens upon reaching the set pressure and fuel can flow from the accumulator 62 into the fuel tank 24. If the internal combustion engine has a plurality of cylinders, then a common pressure accumulator 62 can be used for the fuel injectors of all cylinders.

Das erste Steuerventil 60 ist elektrisch steuerbar und weist einen Aktor 61 auf, der ein Elektromagnet oder ein Piezoaktor sein kann, der elektrisch angesteuert wird und durch den ein Ventilglied des Steuerventils 60 bewegbar ist. Das erste Steuerventil 60 kann druckausgeglichen oder nicht druckausgeglichen ausgebildet sein. Das erste Steuerventil 60 ist als ein 2/2-Wegeventil ausgebildet und durch dieses wird in einer ersten Schaltstellung die Verbindung 59 zum Druckspeicher 62 geöffnet und in einer zweiten Schaltstellung wird die Verbindung 59 zum Druckspeicher 62 getrennt. Das Steuerventil 60 wird durch eine elektrische Steuereinrichtung 66 in Abhängigkeit von Betriebsparametern der Brennkraftmaschine gesteuert.The first control valve 60 is electrically controllable and has an actuator 61, which may be an electromagnet or a piezoelectric actuator, which is electrically controlled and through which a valve member of the control valve 60 is movable. The first control valve 60 may be pressure compensated or non-pressure balanced. The first control valve 60 is designed as a 2/2-way valve and through this the connection 59 is opened to the accumulator 62 in a first switching position and in a second switching position, the connection 59 is disconnected to the pressure accumulator 62. The control valve 60 is controlled by an electric control device 66 as a function of operating parameters of the internal combustion engine.

Zur Steuerung des Druckes im Steuerdruckraum 52 ist ein zweites Steuerventil 68 vorgesehen, durch das eine Verbindung 70 des Steuerdruckraums 52 mit einem Entlastungsraum, beispielsweise dem Kraftstoffvorratsbehälter 24, gesteuert wird. Das zweite Steuerventil 68 ist elektrisch steuerbar und weist einen Aktor 69 auf, der ein Elektromagnet oder ein Piezoaktor sein kann, der elektrisch angesteuert wird und durch den ein Ventilglied des Steuerventils 68 bewegbar ist. Das zweite Steuerventil 68 ist vorzugsweise druckausgeglichen ausgebildet, kann jedoch auch nicht druckausgeglichen sein. Das zweite Steuerventil 68 ist als ein 2/2-Wegeventil ausgebildet, durch das in einer ersten Schaltstellung die Verbindung 70 des Steuerdruckraums 52 mit dem Kraftstoffvorratsbehälter 24 geöffnet ist und durch das in einer zweiten Schaltstellung die Verbindung 70 des Steuerdruckraums 52 mit dem Kraftstoffvorratsbehälter 24 getrennt ist. In der Verbindung 59 des Steuerdruckraums 52 mit dem Kanal 54 ist eine Drosselstelle 58 vorgesehen und in der Verbindung 70 des Steuerdruckraums 52 mit dem Kraftstoffvorratsbehälter 24 ist zwischen dem Steuerdruckraum 52 und dem zweiten Steuerventil 68 eine weitere Drosselstelle 71 vorgesehen. Das zweite Steuerventil 68 wird ebenfalls durch die Steuereinrichtung 66 gesteuert. Die Steuerung der Steuerventile 60,68 durch die Steuereinrichtung 66 erfolgt abhängig von Betriebsparametern der Brennkraftmaschine, wie beispielsweise Drehzahl, Last und Temperatur.To control the pressure in the control pressure chamber 52, a second control valve 68 is provided, through which a connection 70 of the control pressure chamber 52 with a discharge chamber, such as the fuel tank 24, is controlled. The second control valve 68 is electrically controllable and has an actuator 69, which may be an electromagnet or a piezoelectric actuator, which is electrically controlled and through which a valve member of the control valve 68 is movable. The second control valve 68 is preferably formed pressure balanced, but can not be pressure balanced. The second control valve 68 is designed as a 2/2-way valve, through which the connection 70 of the control pressure chamber 52 is opened with the fuel tank 24 in a first switching position and separated by the connection 70 of the control pressure chamber 52 with the fuel tank 24 in a second switching position is. In the connection 59 of the control pressure chamber 52 with the channel 54, a throttle body 58 is provided and in the connection 70 of the control pressure chamber 52 to the fuel tank 24 is between the Control pressure chamber 52 and the second control valve 68, a further throttle point 71 is provided. The second control valve 68 is also controlled by the controller 66. The control of the control valves 60,68 by the control device 66 is dependent on operating parameters of the internal combustion engine, such as speed, load and temperature.

Nachfolgend wird die Funktion der Kraftstoffeinspritzeinrichtung gemäß dem ersten Ausführungsbeispiel erläutert. Beim Saughub des Pumpenkolbens 18 wird durch die Förderpumpe 21 Kraftstoff aus dem Kraftstoffvorratsbehälter 24 durch das geöffnete Rückschlagventil 23 oder die durch die Steuerkante des Pumpenkolbens 18 geöffnete Verbindung in den Pumpenarbeitsraum 22 gefördert. Beim Förderhub des Pumpenkolbens 18 schließt das Rückschlagventil 23 bzw. wird die Verbindung vom Pumpenkolben 18 überdeckt und das Rückschlagventil 25 öffnet, wobei das erste Steuerventil 60 geöffnet sein kann, so daß die Verbindung 59 mit dem Druckspeicher 62 geöffnet ist. Wenn die Kraftstoffeinspritzung mit einer Voreinspritzung beginnen soll, so wird das erste Steuerventil 60 durch die Steuereinrichtung 66 geschlossen, so daß die Verbindung 59 zum Druckspeicher 62 getrennt ist und sich im Pumpenarbeitsraum 22 Hochdruck aufbauen kann. Der im Pumpenarbeitsraum 22 herrschende Druck wirkt über die Leitung 14 und den Kanal 54 im Ventilkörper 26 auch im Druckraum 40. Das zweite Steuerventil 68 wird durch die Steuereinrichtung 66 geöffnet, so daß sich im Steuerdruckraum 52 trotz dessen Verbindung 56 mit dem Kanal 54 kein Hochdruck aufbauen kann, sondern dieser zum Kraftstoffvorratsbehälter 24 hin abgebaut wird. Durch die Drosselstellen 58 und 71 wird erreicht, daß aus dem Kanal 54 nur eine geringe Kraftstoffmenge in den Kraftstoffvorratsbehälter 24 abfließen kann. Wenn der im Druckraum 40 herrschende Druck eine derartige Höhe erreicht hat, daß dieser über die Druckschulter 42 auf das Einspritzventilglied 28 eine in Öffnungsrichtung 29 wirkende Kraft ausübt, die größer ist als die Kraft der Schließfeder 44, so hebt das Einspritzventilglied 28 mit seiner Dichtfläche 34 vom Ventilsitz 36 ab und Kraftstoff wird durch die Einspritzöffnungen 32 in den Brennraum des Zylinders der Brennkraftmaschine eingespritzt. Der Öffnungsdruck des Kraftstoffeinspritzventils 12 ist dabei wegen dem geöffneten zweiten Steuerventil 68 nur von der Kraft der Schließfeder 44 abhängig. Der Druckverlauf während der Einspritzung ist durch das Profil des Nockens 20 bestimmt.Hereinafter, the operation of the fuel injection device according to the first embodiment will be explained. During the suction stroke of the pump piston 18, fuel is conveyed from the fuel reservoir 24 through the open check valve 23 or the connection opened by the control edge of the pump piston 18 into the pump working chamber 22 by the feed pump 21. When the delivery stroke of the pump piston 18, the check valve 23 closes or the connection is covered by the pump piston 18 and the check valve 25 opens, wherein the first control valve 60 can be opened, so that the connection 59 is opened with the pressure accumulator 62. If the fuel injection is to start with a pilot injection, the first control valve 60 is closed by the control device 66, so that the connection 59 is disconnected from the pressure accumulator 62 and high pressure can build up in the pump working space 22. The pressure prevailing in the pump working chamber 22 pressure acts via the line 14 and the channel 54 in the valve body 26 in the pressure chamber 40. The second control valve 68 is opened by the control device 66, so that in the control pressure chamber 52 in spite of its connection 56 with the channel 54 no high pressure can build, but this is reduced to the fuel tank 24 out. By the throttle points 58 and 71 it is achieved that from the channel 54 only a small amount of fuel in the Fuel tank 24 can drain. When the pressure prevailing in the pressure chamber 40 has reached such a height that it exerts on the injection valve member 28 on the injection valve member 28 in the opening direction 29 acting force which is greater than the force of the closing spring 44, the injection valve member 28 lifts with its sealing surface 34th from the valve seat 36 and fuel is injected through the injection openings 32 in the combustion chamber of the cylinder of the internal combustion engine. The opening pressure of the fuel injection valve 12 is only dependent on the force of the closing spring 44 because of the opened second control valve 68. The pressure curve during the injection is determined by the profile of the cam 20.

Alternativ kann auch vorgesehen sein, daß während der Voreinspritzung das erste Steuerventil 60 geöffnet ist, so daß die Verbindung 59 zum Druckspeicher 62 geöffnet ist. In diesem Fall ist das Druckniveau, bei dem die Voreinspritzung erfolgt, durch den mittels des Druckbegrenzungsventils 64 im Druckspeicher 62 eingestellten Druck bestimmt. Der Öffnungsdruck des Kraftstoffeinspritzventils 12 ist dabei niedriger als der im Druckspeicher 62 durch das Druckbegrenzungsventil 64 eingestellte Druck. In Figur 3 ist der Verlauf des Druckes p an den Einspritzöffnungen 32 des Kraftstoffeinspritzventils 12 über der Zeit t während einem Einspritzzyklus dargestellt. Die Voreinspritzung entspricht dabei einer in Figur 3 mit I bezeichneten Einspritzphase.Alternatively, it may also be provided that during the pre-injection, the first control valve 60 is opened, so that the connection 59 is open to the pressure accumulator 62. In this case, the pressure level at which the pilot injection takes place is determined by the pressure set in the pressure accumulator 62 by means of the pressure limiting valve 64. The opening pressure of the fuel injection valve 12 is lower than the pressure set in the pressure accumulator 62 by the pressure limiting valve 64. FIG. 3 shows the course of the pressure p at the injection openings 32 of the fuel injection valve 12 over the time t during an injection cycle. The pilot injection corresponds to an injection phase designated by I in FIG.

Zur Beendigung der Voreinspritzung wird das zweite Steuerventil 68 durch die Steuereinrichtung 66 geschlossen, so daß der Steuerdruckraum 52 vom Kraftstoffvorratsbehälter 24 getrennt ist und sich im Steuerdruckraum 52 über dessen Verbindung 56 mit dem Kanal 54 Druck aufbaut. Hierdurch wird über den Kolben 50 auf das Einspritzventilglied 28 eine die Kraft der Schließfeder 44 unterstützende Kraft erzeugt, so daß das Einspritzventilglied 28 entgegen seiner Öffnungsrichtung 29 bewegt und mit seiner Dichtfläche 34 am Ventilsitz 36 zur Anlage kommt und die Einspritzung beendet wird.To complete the pilot injection, the second control valve 68 is closed by the control device 66, so that the control pressure chamber 52 is separated from the fuel tank 24 and builds up in the control pressure chamber 52 via the connection 56 with the channel 54 pressure. As a result, via the piston 50 to the injection valve member 28 a the Force of the closing spring 44 generates supporting force, so that the injection valve member 28 moves against its opening direction 29 and comes with its sealing surface 34 on the valve seat 36 to the plant and the injection is terminated.

Für eine nachfolgende Haupteinspritzung wird das zweite Steuerventil 68 durch die Steuereinrichtung 66 geöffnet, so daß der Steuerdruckraum 52 wieder entlastet ist und das Kraftstoffeinspritzventil 12 öffnet. Das erste Steuerventil 60 kann beim Beginn der Haupteinspritzung geschlossen sein, so daß die Verbindung 59 zum Druckspeicher 62 getrennt ist und sich in der Leitung 14 und dem Druckraum 40 des Kraftstoffeinspritzventils 12 ein Druckaufbau entsprechend dem Profil des Nockens 20 ergibt. Alternativ kann auch vorgesehen sein, daß das erste Steuerventil 60 zunächst noch geöffnet bleibt, so daß sich infolge der offenen Verbindung 59 zum Druckspeicher 62 in der Leitung 14 und im Druckraum 40 des Kraftstoffeinspritzventils 12 nur ein Druck entsprechend dem durch das Druckbegrenzungsventil 64 im Druckspeicher 62 eingestellten Druck aufbauen kann. Die Haupteinspritzung beginnt dann mit einem Druckniveau wie auch die Voreinspritzung erfolgt ist. Die Haupteinspritzung beginnt bei geschlossenem erstem Steuerventil 60 mit einem höheren Druckniveau als bei zunächst geöffnetem erstem Steuerventil 60. Anschließend wird das erste Steuerventil 60 durch die Steuereinrichtung 66 geschlossen, und die Haupteinspritzung erfolgt mit einem Druck, wie er entsprechend dem Profil des Nockens 20 im Pumpenarbeitsraum 22 erzeugt wird. Es kann auch vorgesehen sein, daß zunächst das erste Steuerventil 60 geschlossen wird, jedoch das zweite Steuerventil 68 noch geschlossen bleibt, so daß noch keine Einspritzung erfolgt. Das zweite Steuerventil 68 wird dann erst verzögert geöffnet, wodurch der Beginn der Haupteinspritzung verzögert wird und außerdem die Haupteinspritzung bei einem höheren Druck beginnt. Die Haupteinspritzung entspricht in Figur 3 einer mit II bezeichneten Einspritzphase, wobei der Druckverlauf mit durchgezogener Linie für den Fall dargestellt ist, daß das erste Steuerventil 60 zu Beginn geöffnet ist, und der Druckverlauf mit gestrichelter Linie für den Fall dargestellt ist, daß das erste Steuerventil 60 schon zu Beginn geschlossen ist.For a subsequent main injection, the second control valve 68 is opened by the control device 66, so that the control pressure chamber 52 is relieved again and the fuel injection valve 12 opens. The first control valve 60 may be closed at the beginning of the main injection, so that the connection 59 is separated to the pressure accumulator 62 and in the line 14 and the pressure chamber 40 of the fuel injection valve 12, a pressure build-up corresponding to the profile of the cam 20. Alternatively, it may also be provided that the first control valve 60 remains initially still open, so that only a pressure corresponding to that by the pressure relief valve 64 in the accumulator 62 due to the open connection 59 to the accumulator 62 in the line 14 and the pressure chamber 40 of the fuel injection valve set pressure can build. The main injection then starts at a pressure level as well as the pre-injection has occurred. The main injection begins with the first control valve 60 closed at a higher pressure level than initially opened first control valve 60. Subsequently, the first control valve 60 is closed by the controller 66, and the main injection is carried out at a pressure as in accordance with the profile of the cam 20 in the pump working space 22 is generated. It may also be provided that initially the first control valve 60 is closed, but the second control valve 68 still remains closed, so that no injection takes place. The second control valve 68 is then opened only delayed, whereby the start of the main injection is delayed and also the Main injection starts at a higher pressure. The main injection corresponds in Figure 3 to an injection phase denoted by II, wherein the pressure curve is shown in solid line in the event that the first control valve 60 is opened at the beginning, and the pressure curve is shown in dashed line in the event that the first control valve 60 is already closed at the beginning.

Zur Beendigung der Haupteinspritzung wird das zweite Steuerventil 68 durch die Steuereinrichtung 66 geschlossen, so daß der Steuerdruckraum 52 vom Kraftstoffvorratsbehälter 24 getrennt ist und sich im Steuerdruckraum 52 durch dessen Verbindung mit dem Kanal 54 und damit dem Pumpenarbeitsraum 22 Hochdruck aufbaut, durch den das Kraftstoffeinspritzventil 12 geschlossen wird. Das erste Steuerventil 60 bleibt dabei geschlossen, so daß die Verbindung 59 zum Druckspeicher 62 getrennt ist. Für eine Nacheinspritzung wird das zweite Steuerventil 68 durch die Steuereinrichtung 66 nochmals geöffnet, so daß der Steuerdruckraum 52 wieder entlastet ist und das Kraftstoffeinspritzventil 12 öffnet. Die Nacheinspritzung erfolgt mit einem Druckverlauf entsprechend dem Profil des Nockens 20. Alternativ kann auch vorgesehen sein, daß zur Nacheinspritzung das erste Steuerventil 60 geöffnet wird, so daß die Nacheinspritzung nur mit dem Druckniveau entsprechend dem Druckspeicher 62 erfolgt. Zur Beendigung der Nacheinspritzung wird das zweite Steuerventil 68 durch die Steuereinrichtung 66 geschlossen und/oder das erste Steuerventil 60 durch die Steuereinrichtung 66 geöffnet. Die Nacheinspritzung entspricht einer in Figur 3 mit III bezeichneten Einspritzphase.To terminate the main injection, the second control valve 68 is closed by the control device 66, so that the control pressure chamber 52 is separated from the fuel tank 24 and in the control pressure chamber 52 by its connection with the channel 54 and thus the pump working chamber 22 builds high pressure, through which the fuel injection valve 12th is closed. The first control valve 60 remains closed, so that the connection 59 is disconnected to the accumulator 62. For a post-injection, the second control valve 68 is opened again by the control device 66, so that the control pressure chamber 52 is relieved again and the fuel injection valve 12 opens. The post-injection is carried out with a pressure curve corresponding to the profile of the cam 20. Alternatively, it can also be provided that the post-injection, the first control valve 60 is opened, so that the post-injection takes place only with the pressure level corresponding to the pressure accumulator 62. To end the post-injection, the second control valve 68 is closed by the control device 66 and / or the first control valve 60 is opened by the control device 66. The post-injection corresponds to an injection phase designated III in FIG.

Nach Beendigung der Nacheinspritzung kann das zweite Steuerventil 68 geschlossen oder geöffnet sein. Das erste Steuerventil 60 ist geöffnet, so daß die Verbindung 59 zum Druckspeicher 62 geöffnet ist. Im Pumpenarbeitsraum 22 fällt der Druck bis auf den Druck im Kraftstoffvorratsbehälter 24 bzw. den von der Förderpumpe 21 erzeugten Druck ab. Der Pumpenarbeitsraum 22 ist durch das Rückschlagventil 25 von der Leitung 14 getrennt, wobei in der Leitung 14, im Kanal 54 und im Druckraum 40 des Kraftstoffeinspritzventils 12 ein Druck entsprechend dem durch das Druckbegrenzungsventil 64 im Druckspeicher 62 bestimmten Druck einstellt.After completion of the post-injection, the second control valve 68 may be closed or opened. The first Control valve 60 is opened, so that the connection 59 is open to the pressure accumulator 62. In the pump working chamber 22, the pressure drops to the pressure in the fuel tank 24 or the pressure generated by the feed pump 21. The pump chamber 22 is separated by the check valve 25 from the line 14, wherein in the conduit 14, in the channel 54 and in the pressure chamber 40 of the fuel injection valve 12, a pressure corresponding to the predetermined by the pressure relief valve 64 in the accumulator 62 pressure.

In Figur 2 ist die Kraftstoffeinspritzeinrichtung gemäß einem zweiten Ausführungsbeispiel dargestellt, bei dem der grundsätzliche Aufbau gleich ist wie beim vorstehend erläuterten ersten Ausführungsbeispiel, jedoch die Steuerung des Drucks im Druckspeicher 62 modifiziert ist. Zur Steuerung des Drucks im Druckspeicher 62 ist anstelle des Druckbegrenzungsventils 64 ein drittes Steuerventil 74 vorgesehen. Das dritte Steuerventil 74 ist elektrisch steuerbar und weist einen Aktor 75 auf, der ein Elektromagnet oder ein Piezoaktor sein kann, der elektrisch angesteuert wird und durch den ein Ventilglied des Steuerventils 74 bewegbar ist. Das dritte Steuerventil 74 ist als ein 2/2-Wegeventil ausgebildet und durch dieses wird in einer ersten Schaltstellung eine Verbindung 76 des Druckspeichers 62 mit dem Kraftstoffvorratsbehälter 24 als Entlastungsraum geöffnet und in einer zweiten Schaltstellung wird die Verbindung 76 zum Kraftstoffvorratsbehälter 24 getrennt. Das dritte Steuerventil 74 wird ebenfalls von der Steuereinrichtung 66 angesteuert. Es ist außerdem ein Drucksensor 78 vorgesehen, durch den der Druck im Druckspeicher 62 erfaßt wird und der mit der Steuereinrichtung 66 verbunden ist. Durch entsprechende Ansteuerung des dritten Steuerventils 74 durch die Steuereinrichtung 66 kann der Druck im Druckspeicher 62 variabel eingestellt werden. Beispielsweise kann für die Voreinspritzphase I und den Beginn der Haupteinspritzphase II der Druck im Druckspeicher 62 erhöht werden und variabel abhängig von Betriebsparametern der Brennkraftmaschine eingestellt werden, so daß entsprechend der Druck, bei dem die Voreinspritzung erfolgt und die Haupteinspritzung beginnt, variabel ist. Auch der Standdruck in der Leitung 14 und dem Druckraum 40 des Kraftstoffeinspritzventils 12 bei entlastetem Pumpenarbeitsraum 22 kann variabel eingestellt werden. Ansonsten ist die Funktionsweise der Kraftstoffeinspritzeinrichtung gemäß dem zweiten Ausführungsbeispiel gleich wie beim ersten Ausführungsbeispiel2 shows the fuel injection device according to a second embodiment, in which the basic structure is the same as in the first embodiment explained above, but the control of the pressure in the pressure accumulator 62 is modified. For controlling the pressure in the pressure accumulator 62, a third control valve 74 is provided instead of the pressure limiting valve 64. The third control valve 74 is electrically controllable and has an actuator 75, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 74 is movable. The third control valve 74 is designed as a 2/2-way valve and through this a connection 76 of the pressure accumulator 62 is opened with the fuel tank 24 as a relief space in a first switching position and in a second switching position, the connection 76 is disconnected to the fuel tank 24. The third control valve 74 is likewise controlled by the control device 66. In addition, a pressure sensor 78 is provided, by which the pressure in the pressure accumulator 62 is detected and which is connected to the control device 66. By appropriate control of the third control valve 74 by the control device 66, the pressure in the pressure accumulator 62 can be variably adjusted. For example, for the Pre-injection phase I and the beginning of the main injection phase II, the pressure in the accumulator 62 are increased and can be adjusted variably depending on operating parameters of the internal combustion engine, so that, correspondingly, the pressure at which the pilot injection takes place and the main injection begins, is variable. Even the pressure in the line 14 and the pressure chamber 40 of the fuel injection valve 12 with unloaded pump working chamber 22 can be variably adjusted. Otherwise, the operation of the fuel injection device according to the second embodiment is the same as in the first embodiment

In Figur 4 ist eine weitere Ausführung der Kraftstoffeinspritzeinrichtung dargestellt, bei der der grundsätzliche Aufbau im wesentlichen gleich wie beim ersten oder zweiten Ausführungsbeispiel ist, jedoch die Anordnung und Ausbildung des zweiten Steuerventils 168 modifiziert ist. Das zweite Steuerventil 168 ist elektrisch steuerbar und weist einen Aktor 169 auf, der ein Elektromagnet oder ein Piezoaktor sein kann, der elektrisch angesteuert wird und durch den ein Ventilglied des Steuerventils 168 bewegbar ist. Das zweite Steuerventil 168 ist in der Verbindung 56 des Steuerdruckraums 52 mit dem Kanal 54 angeordnet. Das zweite Steuerventil 168 ist als ein 3/2-Wegeventil ausgebildet, durch das in einer ersten Schaltstellung die Verbindung 56 des Steuerdruckraums 52 mit dem Kanal 54 und damit dem Pumpenarbeitsraum 22 geöffnet ist und der Steuerdruckraum 52 vom Kraftstoffvorratsbehälter 24 als Entlastungsraum getrennt ist. In einer zweiten Schaltstellung des zweiten Steuerventils 168 ist der Steuerdruckraum 52 mit dem Kraftstoffvorratsbehälter 24 als Entlastungsraum verbunden und die Verbindung 56 zum Kanal 54 und damit zum Pumpenarbeitsraum 22 ist getrennt. Zur Ermöglichung der Öffnung des Kraftstoffeinspritzventils 12 wird das zweite Steuerventil 168 durch die Steuereinrichtung 66 in seine zweite Schaltstellung gebracht, in der der Steuerdruckraum 52 in den Kraftstoffvorratsbehälter 24 entlastet ist, und zum Schließen des Kraftstoffeinspritzventils 12 wird das zweite Steuerventil 168 in seine erste Schaltstellung gebracht, in der der Steuerdruckraum 52 mit dem Kanal 54 verbunden ist. Ansonsten ist die Funktionsweise der Kraftstoffeinspritzeinrichtung gemäß dieser modifizierten Ausführung gleich wie beim ersten oder zweiten Ausführungsbeispiel.FIG. 4 shows a further embodiment of the fuel injection device, in which the basic structure is essentially the same as in the first or second embodiment, but the arrangement and design of the second control valve 168 is modified. The second control valve 168 is electrically controllable and has an actuator 169, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 168 is movable. The second control valve 168 is arranged in the connection 56 of the control pressure chamber 52 with the channel 54. The second control valve 168 is designed as a 3/2-way valve, through which the connection 56 of the control pressure chamber 52 with the channel 54 and thus the pump working chamber 22 is opened and the control pressure chamber 52 is separated from the fuel tank 24 as a relief space in a first switching position. In a second switching position of the second control valve 168, the control pressure chamber 52 is connected to the fuel tank 24 as a relief space and the connection 56 to the channel 54 and thus to the pump working chamber 22 is disconnected. To enable opening of the fuel injection valve 12 the second control valve 168 is brought by the control device 66 in its second switching position in which the control pressure chamber 52 is relieved in the fuel tank 24, and to close the fuel injection valve 12, the second control valve 168 is brought into its first switching position in which the control pressure chamber 52 with the channel 54 is connected. Otherwise, the operation of the fuel injection device according to this modified embodiment is the same as in the first or second embodiment.

In Figur 5 ist eine weitere Ausführung der Kraftstoffeinspritzeinrichtung dargestellt, bei der der grundsätzliche Aufbau im wesentlichen gleich wie beim ersten oder zweiten Ausführungsbeispiel ist, jedoch die Anordnung und Ausbildung des zweiten Steuerventils 268 modifiziert ist. Das zweite Steuerventil 268 ist elektrisch steuerbar und weist einen Aktor 269 auf, der ein Elektromagnet oder ein Piezoaktor sein kann, der elektrisch angesteuert wird und durch den ein Ventilglied des Steuerventils 268 bewegbar ist. An das zweite Steuerventil 268 ist einerseits die Leitung 14 angeschlossen und andererseits ist an dieses der Kanal 54 zum Druckraum 40 und die Verbindung 56 zum Steuerdruckraum 52 angeschlossen. Das zweite Steuerventil 268 ist als ein 3/2-Wegeventil ausgebildet, durch das in einer ersten Schaltstellung die Verbindung 56 des Steuerdruckraums 52 mit dem Kanal 54 geöffnet ist und der Kanal 54 von der Leitung 14 und somit vom Pumpenarbeitsraum 22 getrennt ist. In einer zweiten Schaltstellung des zweiten Steuerventils 268 ist durch dieses der Steuerdruckraum 52 vom Kanal 54 getrennt und der Kanal 54 ist mit der Leitung 14 und somit dem Pumpenarbeitsraum 22 verbunden. Der Steuerdruckraum 52 weist eine Verbindung 270 mit dem Kraftstoffvorratsbehälter 24 als Entlastungsraum auf, in der ein zum Kraftstoffvorratsbehälter 24 öffnendes Rückschlagventil 272 angeordnet ist und außerdem eine Drosselstelle vorgesehen sein kann. Zur Ermöglichung der Öffnung des Kraftstoffeinspritzventils 12 wird das zweite Steuerventil 268 durch die Steuereinrichtung 66 in seine zweite Schaltstellung gebracht, in der der Steuerdruckraum 52 vom Kanal 54 getrennt ist und der Kanal 54 mit der Leitung 14 verbunden ist, so daß der von der Kraftstoffpumpe 10 erzeugte Druck in den Druckraum 40 des Kraftstoffeinspritzventils 12 gelangt, wobei der Steuerdruckraum 52 in den Kraftstoffvorratsbehälter 24 entlastet ist. Zum Schließen des Kraftstoffeinspritzventils 12 wird das zweite Steuerventil 268 in seine erste Schaltstellung gebracht, in der der Steuerdruckraum 52 mit dem Kanal 54 verbunden ist, der Kanal 54 jedoch von der Leitung 14 getrennt ist. Der im Druckraum 40 des Kraftstoffeinspritzventils 12 herrschende Druck wirkt dabei auch im Steuerdruckraum 52, wodurch das Kraftstoffeinspritzventil 12 geschlossen wird. Ansonsten ist die Funktionsweise der Kraftstoffeinspritzeinrichtung gemäß dieser modifizierten Ausführung gleich wie beim ersten oder zweiten Ausführungsbeispiel.FIG. 5 shows a further embodiment of the fuel injection device, in which the basic structure is essentially the same as in the first or second embodiment, but the arrangement and design of the second control valve 268 is modified. The second control valve 268 is electrically controllable and has an actuator 269, which may be an electromagnet or a piezoelectric actuator, which is electrically actuated and through which a valve member of the control valve 268 is movable. On the one hand, the line 14 is connected to the second control valve 268 and on the other hand, the channel 54 is connected to the pressure chamber 40 and the connection 56 to the control pressure chamber 52 to this. The second control valve 268 is designed as a 3/2-way valve, through which the connection 56 of the control pressure chamber 52 is opened with the channel 54 in a first switching position and the channel 54 is separated from the line 14 and thus from the pump working chamber 22. In a second switching position of the second control valve 268 is separated by this the control pressure chamber 52 from the channel 54 and the channel 54 is connected to the conduit 14 and thus the pump working chamber 22. The control pressure chamber 52 has a connection 270 with the fuel tank 24 as a relief space in which a fuel tank 24 to open Check valve 272 is arranged and also a throttle point may be provided. To enable the opening of the fuel injection valve 12, the second control valve 268 is brought by the control device 66 in its second switching position in which the control pressure chamber 52 is separated from the channel 54 and the channel 54 is connected to the line 14 so that the fuel pump of the 10th generated pressure in the pressure chamber 40 of the fuel injection valve 12 passes, the control pressure chamber 52 is relieved in the fuel tank 24. To close the fuel injection valve 12, the second control valve 268 is brought into its first switching position, in which the control pressure chamber 52 is connected to the channel 54, the channel 54, however, is separated from the line 14. The pressure prevailing in the pressure chamber 40 of the fuel injection valve 12 also acts in the control pressure chamber 52, whereby the fuel injection valve 12 is closed. Otherwise, the operation of the fuel injection device according to this modified embodiment is the same as in the first or second embodiment.

Claims (8)

  1. Fuel injection device for internal combustion engines having a fuel pump (10) for each cylinder of the internal combustion engine, which fuel pump (10) has a pump piston (18) which is driven in a reciprocating motion by the internal combustion engine, said pump piston delimiting a pump working space (22) to which fuel is supplied from a fuel storage tank (24) and which is connected to a fuel injection valve (12), which fuel injection valve has an injection valve member (28) which controls at least one injection opening (32) and which can be moved counter to a closing force in an opening direction (29) by the prevailing pressure in the pump working space (22), having a first electrically controlled control valve (60), by means of which a connection (59) between the pump working space (22) and a termination space (62) is controlled and having a second electrically controlled control valve (68; 168; 268), by means of which the prevailing pressure in a control pressure space (52) of the fuel injection valve (12) is controlled, by means of which prevailing pressure the injection valve member (28) is at least indirectly acted upon in the closing direction, the termination space (62) being a pressure store in which a pressure which is higher than the prevailing pressure in the fuel storage tank (24) is maintained, characterized in that the pressure in the pressure store (62) is kept at least approximately constant by means of a pressure limiting valve (64) which opens towards the fuel storage tank (24), or is variably adjustable by means of a third electrically controlled control valve (74) which opens towards the fuel storage tank (24).
  2. Fuel injection device according to Claim 1, characterized in that the pressure in the pressure store (62) is sensed by means of a sensor device (78) which is connected to an electrical control device (66), by means of which the third control valve (74) is actuated in order to set a predefined pressure in the pressure store (62).
  3. Fuel injection device according to Claim 1 or 2, characterized in that a connection (76) between the pressure store (62) and a relief space (24) is controlled by means of the third control valve (74).
  4. Fuel injection device according to one of Claims 1 to 3, characterized in that a non-return valve (23), which opens towards the pump working space (22), is arranged in the connection between the pump working space (22) and the fuel storage tank (24), through which connection fuel is supplied to the pump working space (22).
  5. Fuel injection device according to one of the preceding claims, characterized in that a non-return valve (25), which opens towards the first control valve (60), is arranged in the connection between the pump working space (22) and the first control valve (60).
  6. Fuel injection device according to one of the preceding claims, characterized in that the second control valve (168) is designed as a 3/2 directional control valve, by means of which, in a first switching position, the control pressure space (52) is connected to the pump working space (22) and is separated from a relief space (24), and by means of which, in a second switching position, the control pressure space (52) is connected to the relief space (24) and is separated from the pump working space (22).
  7. Fuel injection device according to one of Claims 1 to 5, characterized in that the second control valve (268) is designed as a 3/2 directional control valve, by means of which, in a first switching position, the control pressure space (52) is separated from a pressure space (40) of the fuel injection valve (12) and the pressure space (40) is connected to the pump working space (22), and by means of which, in a second switching position, the control pressure space (52) is connected to the pressure space (40) and the pressure space (40) is separated from the pump working space (22).
  8. Fuel injection valve according to Claim 7, characterized in that the control pressure space (52) has a connection (270) to a relief space (24), in which a non-return valve (272), which opens towards the relief space (24), is preferably arranged.
EP02004726A 2001-03-15 2002-03-01 Fuel injection system for internal combustion engines Expired - Lifetime EP1241347B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10112432A DE10112432A1 (en) 2001-03-15 2001-03-15 Fuel injection device for internal combustion engines
DE10112432 2001-03-15

Publications (3)

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EP1241347A2 EP1241347A2 (en) 2002-09-18
EP1241347A3 EP1241347A3 (en) 2004-03-10
EP1241347B1 true EP1241347B1 (en) 2006-05-10

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EP02004726A Expired - Lifetime EP1241347B1 (en) 2001-03-15 2002-03-01 Fuel injection system for internal combustion engines

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EP (1) EP1241347B1 (en)
DE (2) DE10112432A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7191762B2 (en) * 2002-03-26 2007-03-20 Volvo Lastvagnar Ab Fuel injection system
EP1826397A3 (en) * 2002-05-03 2009-08-05 Delphi Technologies, Inc. Fuel injection system
US7077101B2 (en) * 2002-08-14 2006-07-18 Electro-Motive Diesel, Inc. Hybrid fuel injection system
DE10238951A1 (en) * 2002-08-24 2004-03-11 Robert Bosch Gmbh Fuel injection system
US7059301B2 (en) * 2003-02-20 2006-06-13 Caterpillar Inc. End of injection rate shaping
US7373924B1 (en) * 2007-05-10 2008-05-20 Ford Global Technologies, Llc Method and system to mitigate pump noise in a direct injection, spark ignition engine
US7970526B2 (en) 2009-01-05 2011-06-28 Caterpillar Inc. Intensifier quill for fuel injector and fuel system using same
DE102016015037B3 (en) * 2016-12-16 2018-05-30 L'orange Gmbh fuel injector
JP7344019B2 (en) * 2019-06-24 2023-09-13 株式会社ジャパンエンジンコーポレーション Marine internal combustion engine

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1962720A1 (en) * 1969-05-07 1970-11-19 Univ Magdeburg Tech Equal pressure injection device, especially for diesel engines
DE4118236C2 (en) * 1990-06-06 2000-02-17 Avl Verbrennungskraft Messtech Injection system for internal combustion engines
JP2882209B2 (en) * 1992-09-11 1999-04-12 三菱自動車工業株式会社 Accumulator type fuel injection device
GB9422864D0 (en) * 1994-11-12 1995-01-04 Lucas Ind Plc Fuel system
US5732679A (en) * 1995-04-27 1998-03-31 Isuzu Motors Limited Accumulator-type fuel injection system
DE19640826B4 (en) * 1995-10-03 2004-11-25 Nippon Soken, Inc., Nishio Storage fuel injection device and pressure control device therefor
GB9810327D0 (en) * 1998-05-15 1998-07-15 Lucas Ind Plc Fuel system and pump suitable for use therein
DE69905685T2 (en) * 1998-11-19 2003-10-02 Mitsubishi Motors Corp Fuel injection device of the battery type
EP1008741B1 (en) * 1998-11-20 2003-04-02 Mitsubishi Jidosha Kogyo Kabushiki Kaisha Accumulator type fuel injection system
US6142127A (en) * 1999-01-25 2000-11-07 Siemens Automotive Corporation Restriction structure for reducing gas formation in a high pressure fuel return line
DE19939424A1 (en) * 1999-08-20 2001-03-08 Bosch Gmbh Robert Fuel injection system for an internal combustion engine
DE19939421A1 (en) * 1999-08-20 2001-03-01 Bosch Gmbh Robert Combined stroke / pressure controlled fuel injection method and system for an internal combustion engine
DE60000255T2 (en) * 1999-09-22 2003-03-27 Mitsubishi Motors Corp Reservoir fuel injection device
DE10084656C2 (en) * 2000-03-31 2003-12-18 Mitsubishi Fuso Truck & Bus Method of operating an accumulator fuel injector

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Publication number Publication date
EP1241347A3 (en) 2004-03-10
US20020129792A1 (en) 2002-09-19
DE50206716D1 (en) 2006-06-14
US6651626B2 (en) 2003-11-25
EP1241347A2 (en) 2002-09-18
DE10112432A1 (en) 2002-09-19

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