WO2004016935A1 - Fuel-injection device for an internal combustion engine - Google Patents

Fuel-injection device for an internal combustion engine Download PDF

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Publication number
WO2004016935A1
WO2004016935A1 PCT/DE2003/001580 DE0301580W WO2004016935A1 WO 2004016935 A1 WO2004016935 A1 WO 2004016935A1 DE 0301580 W DE0301580 W DE 0301580W WO 2004016935 A1 WO2004016935 A1 WO 2004016935A1
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WO
WIPO (PCT)
Prior art keywords
pump
chamber
connection
pressure
fuel
Prior art date
Application number
PCT/DE2003/001580
Other languages
German (de)
French (fr)
Inventor
Peter Voigt
Raphael Pourret
François Rossignol
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
Priority to EP03737899A priority Critical patent/EP1525389A1/en
Publication of WO2004016935A1 publication Critical patent/WO2004016935A1/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
    • 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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
    • 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
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/30—Fuel-injection apparatus having mechanical parts, the movement of which is damped
    • F02M2200/304—Fuel-injection apparatus having mechanical parts, the movement of which is damped using hydraulic 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
    • F02M2200/31—Fuel-injection apparatus having hydraulic pressure fluctuations damping elements
    • F02M2200/315—Fuel-injection apparatus having hydraulic pressure fluctuations damping elements for damping fuel pressure fluctuations
    • 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
    • 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
    • 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
    • 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

Definitions

  • the invention is based on one
  • Fuel injection device for an internal combustion engine according to the preamble of claim 1.
  • Such a fuel injection device is known from DE 39 00 763 AI.
  • This fuel injection device has a high-pressure fuel pump and a fuel injection valve for a cylinder of the internal combustion engine.
  • the high-pressure fuel pump has a pump piston which is driven by the internal combustion engine and delimits a pump work space, a connection of the pump work space to a relief space being controlled by an electrically controlled valve.
  • the fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which can be moved in an opening direction against the force of a closing spring arranged in a spring chamber by the pressure prevailing in a pressure chamber having a connection to the pump working chamber.
  • the closing spring is supported on the one hand at least indirectly on the injection valve member and on the other hand at least indirectly on a storage piston.
  • the storage piston delimits a storage space on its side facing away from the closing spring, which has a connection to the pump working space and can be moved into the spring space against the force of the closing spring.
  • the accumulator piston enables fuel to be pre-injected by moving it into the spring chamber as the pressure in the pump work chamber rises due to the pressure prevailing in the accumulator chamber becomes.
  • its injector member first opens for the pre-injection.
  • the bias of the closing spring is increased so that the injection valve member closes again.
  • the injection valve member opens against the increased pretension of the closing spring and a main injection of fuel takes place.
  • the amount of fuel that is injected during the pre-injection is dependent on the operating parameters of the internal combustion engine, in particular the speed, in a map. It was found that the amount of fuel injected during the pre-injection is essentially influenced by pressure waves in the fuel injection device between the pump work space and the pressure space and the storage space. These pressure waves are triggered by the closing process of the control valve when the pump work space is separated from the relief area. The running times of these pressure waves, which are dependent on the length of the connections between the pressure space or the storage space and the pump work space, are therefore of great importance for the fuel injection quantity during the pre-injection and these are not optimal in the known fuel injection device.
  • the fuel injection device with the features according to claim 1 has the advantage that the fuel injection quantity is optimally determined in the map during the pre-injection. This is achieved by coordinating the lengths of the connections between the pressure chamber and the storage chamber with the pump work chamber, which the Determine the transit times of the pressure waves in the ratio specified in claim 1.
  • the embodiment according to claim 2 enables a further optimization of the fuel injection quantity during the pre-injection in the map.
  • the design according to claim 4 allows a large length of the connection of the storage space with the pump work space in a simple manner, which is necessary to achieve the specified ratio of the lengths of the connections, since the length of the connection of the pressure space with the pump work space can be shortened only with difficulty due to design conditions can.
  • FIG. 2 shows an enlarged illustration in FIG. 1 with II and FIG. 3 shows a course of the stroke of an injection valve member of the fuel injection device during an injection cycle.
  • the internal combustion engine has one or more cylinders, a fuel injection device having a high-pressure fuel pump 10 and a fuel injection valve 12 being provided for each cylinder.
  • the fuel injection valve 12 has a valve body 26 which can be constructed in several parts and which is connected to the pump body 14, for example with an intermediate body 27 interposed.
  • a disk 15 can also be arranged between the intermediate body 27 and the pump body 14.
  • An injection valve member 28 is guided in a longitudinally displaceable manner in a bore 30 in the valve body 26.
  • the bore 30 runs at least approximately parallel to the cylinder 16 of the pump body 14, but can also run at an incline to the latter.
  • the valve body 26 faces the combustion chamber of the cylinder of the internal combustion engine facing end region 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, for example, approximately conical sealing surface 34 which interacts with a valve seat 36, for example likewise approximately conical in the valve body 26 in its end region facing the combustion chamber, from or after which the injection openings 32 lead away.
  • 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 passes through a radial expansion of the bore 30 into a pressure chamber 40 surrounding the injection valve member 28.
  • the injection valve member 28 has a pressure shoulder 42 facing the valve seat 36 at the level of the pressure chamber 40 due to a reduction in cross section.
  • a prestressed closing spring 44 engages, by means of which the injection valve member 28 is pressed toward the valve seat 36.
  • the closing spring 44 is arranged in a spring space 46 of the intermediate body 27 which is formed by a bore 47 and which adjoins the bore 30.
  • the closing spring 44 is supported on the one hand at least indirectly, for example via a spring plate, on the injection valve member 28 and on the other hand at least indirectly, for example likewise via a spring plate 51, on a storage piston 50.
  • the accumulator piston 50 is guided tightly in the bore 47 forming the spring space 46 and delimits a storage space 52 in the bore 47 with its end face remote from the closing spring.
  • the storage space 52 has a connection 54 to the pump working space 22 which runs through the intermediate body 27, the disk 15 and the pump body 14 on.
  • the connection 54 has a length 12. In order to achieve the greatest possible length 12 of the connection 54, the connection 54 does not run directly along the shortest route between the storage space 52 and the pump work space 22, but rather has at least one deflection. As shown in FIG.
  • connection 54 starting from the end region of the storage space 52 facing the disk 15, initially extends at least approximately radially to the longitudinal axis of the intermediate body 27, which is the same as the longitudinal axis of the injection valve member 28.
  • a groove 56 is formed in the end face of the intermediate body 27 facing the disk 15, or alternatively in the end face of the disk 15 facing the intermediate body 27.
  • the groove 56 is closed by the disc 15, so that a closed channel is formed.
  • the groove 56 is followed by a bore 58 in the intermediate body 27, which for example runs at least approximately parallel to the longitudinal axis of the intermediate body 27.
  • the bore 58 opens into a further groove 60 formed in the end face of the intermediate body 27 facing the valve body 26.
  • the groove 60 can alternatively also be formed in the end face of the valve body 26 facing the intermediate body 27.
  • the groove 60 extends, for example, at least approximately radially outwards.
  • a further bore 62 leads from the radially outer end of the groove 60 through the intermediate body 27, which for example runs at least approximately parallel to the bore 58 and opens out on the end face of the intermediate body 27 facing the disk 15. Close in the disc 15 and the pump body 14 more holes as part of the connection 54.
  • the length 12 of the connection is the sum of the lengths of the grooves 56.60, the bores 58.60 in the intermediate body 27 and the bores in the disk 15 and the pump body 14 up to the pump working space 22.
  • the ratio ⁇ of the length 11 of the connection 48 of the pressure chamber 40 is
  • Fuel injection valve 12 with the pump work chamber 22 is constructive through the construction of the
  • the function of the fuel injection device is explained below.
  • the pump working chamber 22 is filled with fuel during the suction stroke of the pump piston 18.
  • the control valve 23 is initially open, so that no high pressure can build up in the pump work chamber 22.
  • the control valve 23 is closed by the control device 25, so that the pump working space 22 is separated from the fuel reservoir 24 and builds up in this high pressure. If the pressure in the pump working chamber 22 and in the pressure chamber 40 is so high that the force acting on the injection valve member 28 via the pressure shoulder 42 in the opening direction 29 is greater than the force of the closing spring 44, the injection valve member 28 moves in the opening direction 29 and gives the at least one injection port 32 through which fuel into the Combustion chamber of the cylinder is injected.
  • the storage piston 50 is in a starting position in which it is arranged closest to the disk 15. The pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam 20.
  • the accumulator piston 50 performs an evasive stroke movement and moves away from the disk 15 into the spring chamber 46 into it, with the storage space 52 being enlarged. This causes a pressure drop in the pump work chamber 22 and also increases the pretension of the closing spring 44, which is supported on the accumulator piston 50.
  • FIG. 3 shows the opening stroke of the injection valve member 28 over time during an injection cycle, the stroke for the pre-injection being designated I in FIG.
  • the amount of fuel injected is essentially determined by the opening pressure of the accumulator piston 50, that is the pressure in the pump working chamber 22 at which the accumulator piston 50 begins its evasive stroke movement.
  • By closing the Control valve 23 during the delivery stroke of the pump piston 18 causes pressure waves which propagate from the pump working chamber 22 via the connection 48 to the pressure chamber 40 and via the connection 54 to the storage chamber 52.
  • the transit times of the pressure waves in the connections 48 and 54 are coordinated with one another in such a way that under different operating conditions, in particular different speeds of the Internal combustion engine, in each case an optimal fuel injection quantity is reached during the pre-injection.
  • the opening stroke of the injection valve member 28 during the pre-injection can be hydraulically limited by a damping device.
  • a damping device is known from DE 39 00 762 AI and the corresponding US Pat. No. 5,125,580 and DE 39 00 763 AI and the corresponding US Pat. No. 5,125,581, the contents of which are hereby expressly incorporated by reference.
  • the pressure in the pump working chamber 22 subsequently rises further in accordance with the profile of the cam 20, so that the pressure force acting on the injection valve member 28 increases again in the opening direction 29 and increases the closing force due to the increased preload of the closing spring 44, so that the
  • Fuel injection valve 12 opens again. A larger amount of fuel is injected over a longer period of time than during the pre-injection.
  • the stroke of the injection valve member 28 during the main injection is designated II in FIG. 3.
  • the time period and the amount of fuel injected during this main injection are determined by the point in time at which the control valve 23 is opened again by the control device 25.

Abstract

The invention relates to a fuel injection device comprising a high-pressure fuel pump (10) and a fuel-injection valve (12) for a cylinder of the internal combustion engine. Said high-pressure fuel pump (10) has a working chamber (22) and the fuel-injection valve (12) has an injection valve member (28), which is used to control at least one injection orifice (32) and which can be displaced in an opening direction (29) against the force of a closing spring (44), by means of the pressure prevailing in a pressure chamber (40) that comprises a connection (48) to the working chamber (22). According to the invention, one end of the closing spring (44) is supported on the injection valve member (28) and the other end is supported on a displaceable accumulator plunger (50), whose opposite face to the closing spring (44) delimits an accumulator chamber (52) that has a connection (54) to the working chamber (22) and which is displaceable in a spring chamber (46) against the force of the closing spring (44). The ratio (μ) of the length (11) of the connection (48) from the pressure chamber (40) to the working chamber (22) to the length (12) of the connection (54) from the accumulator chamber (52) to the working chamber (22) is between 1.5 and 4.

Description

Kraftstoffeinspritzeinrichtung für eine BrennkraftmaschineFuel injection device for an internal combustion engine
Stand der TechnikState of the art
Die Erfindung geht aus von einerThe invention is based on one
Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine nach der Gattung des Anspruchs 1.Fuel injection device for an internal combustion engine according to the preamble of claim 1.
Eine solche Kraftstoffeinspritzeinrichtung ist durch die DE 39 00 763 AI bekannt. Diese Kraftstoffeinspritzeinrichtung weist eine Kraftstoffhochdruckpumpe und ein Kraftstoffeinspritzventil für einen Zylinder der Brennkraftmaschine auf. Die Kraftstoffhochdruckpumpe weist einen durch die Brennkraftmaschine angetriebenen, einen Pumpenarbeitsraum begrenzenden Pumpenkolben auf, wobei durch ein elektrisch gesteuertes Ventil eine Verbindung des Pumpenarbeitsraums mit einem Entlastungsraum gesteuert wird. Das Kraftstoffeinspritzventil weist ein Einspritzventilglied auf, durch das wenigstens eine Einspritzöffnung gesteuert wird und das durch den in einem eine Verbindung mit dem Pumpenarbeitsraum aufweisenden Druckraum herrschenden Druck gegen die Kraft einer in einem Federraum angeordneten Schließfeder in einer Öffnungsrichtung bewegbar ist. Die Schließfeder stützt sich einerseits zumindest mittelbar am Einspritzventilglied und andererseits zumindest mittelbar an einem Speicherkolben ab. Der Speicherkolben begrenzt auf seiner der Schließfeder abgewandten Seite einen Speicherraum, der eine Verbindung mit dem Pumpenarbeitsraum aufweist und ist gegen die Kraft der Schließfeder in den Federraum bewegbar. Der Speicherkolben ermöglicht eine Voreinspritzung von Kraftstoff, indem dieser bei ansteigendem Druck im Pumpenarbeitsraum durch den im Speicherraum herrschenden Druck in den Federraum bewegt wird. Bei steigendem Druck im Pumpenarbeitsraum und damit im Druckraum des Kraftstoffeinspritzventils öffnet dessen Einspritzventilglied zunächst für die Voreinspritzung. Bei der Bewegung des Speicherkolbens in den Federraum wird die Vorspannung der Schließfeder erhöht, so daß das Einspritzventilglied wieder schließt. Bei weiterem Druckanstieg im Pumpenarbeitsraum und im Druckraum öffnet das Einspritzventilglied gegen die erhöhte Vorspannung der Schließfeder und es erfolgt eine Haupteinspritzung von Kraftstoff. Die Kraftstoffmenge, die bei der Voreinspritzung eingespritzt wird, ist in einem Kennfeld abhängig von Betriebsparametern der Brennkraftmaschine, insbesondere der Drehzahl. Es wurde festgestellt, daß die Kraftstoffeinspritzmenge bei der Voreinspritzung dabei wesentlich von Druckwellen in der Kraftstoffeinspritzeinrichtung zwischen dem Pumpenarbeitsraum und dem Druckraum sowie dem Speicherraum beeinflußt wird. Diese Druckwellen werden durch den Schließvorgang des Steuerventils ausgelöst, wenn der Pumpenarbeitsraum vom Entlastungsbereich getrennt wird. Die Laufzeiten dieser Druckwellen, die abhängig von der Länge der Verbindungen zwischen dem Druckraum bzw. dem Speicherraum und dem Pumpenarbeitsraum sind, sind daher von großer Bedeutung für die Kraftstoffeinspritzmenge bei der Voreinspritzung und diese sind bei der bekannten Kraftstoffeinspritzeinrichtung nicht optimal.Such a fuel injection device is known from DE 39 00 763 AI. This fuel injection device has a high-pressure fuel pump and a fuel injection valve for a cylinder of the internal combustion engine. The high-pressure fuel pump has a pump piston which is driven by the internal combustion engine and delimits a pump work space, a connection of the pump work space to a relief space being controlled by an electrically controlled valve. The fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which can be moved in an opening direction against the force of a closing spring arranged in a spring chamber by the pressure prevailing in a pressure chamber having a connection to the pump working chamber. The closing spring is supported on the one hand at least indirectly on the injection valve member and on the other hand at least indirectly on a storage piston. The storage piston delimits a storage space on its side facing away from the closing spring, which has a connection to the pump working space and can be moved into the spring space against the force of the closing spring. The accumulator piston enables fuel to be pre-injected by moving it into the spring chamber as the pressure in the pump work chamber rises due to the pressure prevailing in the accumulator chamber becomes. When the pressure in the pump work chamber and thus in the pressure chamber of the fuel injector increases, its injector member first opens for the pre-injection. When the accumulator piston moves into the spring chamber, the bias of the closing spring is increased so that the injection valve member closes again. If the pressure in the pump work chamber and in the pressure chamber continues to rise, the injection valve member opens against the increased pretension of the closing spring and a main injection of fuel takes place. The amount of fuel that is injected during the pre-injection is dependent on the operating parameters of the internal combustion engine, in particular the speed, in a map. It was found that the amount of fuel injected during the pre-injection is essentially influenced by pressure waves in the fuel injection device between the pump work space and the pressure space and the storage space. These pressure waves are triggered by the closing process of the control valve when the pump work space is separated from the relief area. The running times of these pressure waves, which are dependent on the length of the connections between the pressure space or the storage space and the pump work space, are therefore of great importance for the fuel injection quantity during the pre-injection and these are not optimal in the known fuel injection device.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Kraftstoffeinspritzeinrichtung mit den Merkmalen gemäß Anspruch 1 hat demgegenüber den Vorteil, daß die Kraftstoffeinspritzmenge bei der Voreinspritzung im Kennfeld optimal festgelegt ist. Dies wird durch die Abstimmung der Längen der Verbindungen des Druckraums und des Speicherraums mit dem Pumpenarbeitsraum, die die Laufzeiten der Druckwellen bestimmen, in dem im Anspruch 1 angegebenen Verhältnis erreicht.The fuel injection device according to the invention with the features according to claim 1 has the advantage that the fuel injection quantity is optimally determined in the map during the pre-injection. This is achieved by coordinating the lengths of the connections between the pressure chamber and the storage chamber with the pump work chamber, which the Determine the transit times of the pressure waves in the ratio specified in claim 1.
In den abhängigen Ansprüchen sind vorteilhafte Ausgestaltungen und Weiterbildungen der erfindungsgemäßen Kraftstoffeinspritzeinrichtung angegeben. Die Ausbildung gemäß Anspruch 2 ermöglicht eine weitere Optimierung der Kraftstoffeinspritzmenge bei der Voreinspritzung im Kennfeld. Die Ausbildung gemäß Anspruch 4 ermöglicht auf einfache Weise eine große Länge der Verbindung des Speicherraums mit dem Pumpenarbeitsraum, die zur Erreichung des angegebenen Verhältnisses der Längen der Verbindungen erforderlich ist, da die Länge der Verbindung des Druckraums mit dem Pumpenarbeitsraum aufgrund konstruktiver Gegebenheiten nur schwer verkürzt werden kann.Advantageous refinements and developments of the fuel injection device according to the invention are specified in the dependent claims. The embodiment according to claim 2 enables a further optimization of the fuel injection quantity during the pre-injection in the map. The design according to claim 4 allows a large length of the connection of the storage space with the pump work space in a simple manner, which is necessary to achieve the specified ratio of the lengths of the connections, since the length of the connection of the pressure space with the pump work space can be shortened only with difficulty due to design conditions can.
Zeichnungdrawing
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eineAn embodiment of the invention is shown in the drawing and explained in more detail in the following description. 1 shows a
Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine in vereinfachter schematischer Darstellung, Figur 2 einen in Figur 1 mit II bezeichneten Ausschnitt in vergrößerter Darstellung und Figur 3 einen Verlauf des Hubs eines Einspritzventilglieds der Kraftstoffeinspritzeinrichtung während eines Einspritzzyklus.Fuel injection device for an internal combustion engine in a simplified schematic representation, FIG. 2 shows an enlarged illustration in FIG. 1 with II and FIG. 3 shows a course of the stroke of an injection valve member of the fuel injection device during an injection cycle.
Beschreibung des AusführungsbeispielsDescription of the embodiment
In den Figuren 1 und 2 ist eineIn Figures 1 and 2 is one
Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine 10 eines Kraftfahrzeugs dargestellt. Die Brennkraftmaschine weist einen oder mehrere Zylinder auf, wobei für jeden Zylinder eine Kraftstoffeinspritzeinrichtung mit einer Kraftstoffhochdruckpumpe 10 und einem Kraftstoffeinspritzventil 12 vorgesehen ist. Die Kraftstoffhochdruckpumpe 10 und dasFuel injection device for an internal combustion engine 10 of a motor vehicle shown. The internal combustion engine has one or more cylinders, a fuel injection device having a high-pressure fuel pump 10 and a fuel injection valve 12 being provided for each cylinder. The high pressure fuel pump 10 and that
Kraftstoffeinspritzventil 12 sind zu einer sogenannten Pumpe-Düse-Einheit zusammengefaßt. DieFuel injection valve 12 are combined to form a so-called pump-nozzle unit. The
Kraftstoffhochdruckpumpe 10 weist einen Pumpenkörper 14 auf, in dem in einem Zylinder 16 ein Pumpenkolben 18 dicht geführt ist, 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 Kraftstoff aus einem Kraftstoffvorratsbehälter 24 zugeführt, beispielsweise mittels einer Förderpumpe 21. Der Pumpenarbeitsraum 22 weist eine Verbindung mit einem Entlastungsbereich auf, als der beispielsweise zumindest mittelbar derHigh-pressure fuel pump 10 has a pump body 14, in which a pump piston 18 is tightly guided in a cylinder 16, 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 is supplied to the pump work chamber 22 from a fuel reservoir 24, for example by means of a feed pump 21. The pump work chamber 22 has a connection to a relief region than that, for example, at least indirectly
Kraftstoffvorratsbehälter 24 dienen kann, und die von einem elektrisch betätigten Steuerventil 23 gesteuert wird. Das Steuerventil 23 ist mit einer Steuereinrichtung 25 verbunden .Fuel tank 24 can serve, and which is controlled by an electrically operated control valve 23. The control valve 23 is connected to a control device 25.
Das Kraftstoffeinspritzventil 12 weist einen Ventilkörper 26 auf, der mehrteilig ausgebildet sein kann, und der mit dem Pumpenkörper 14, beispielsweise unter Zwischenlage eines Zwischenkörpers 27, verbunden ist. Zwischen dem Zwischenkörper 27 und dem Pumpenkörper 14 kann noch eine Scheibe 15 angeordnet sein. Im Ventilkörper 26 ist in einer Bohrung 30 ein Einspritzventilglied 28 längsverschiebbar geführt. Die Bohrung 30 verläuft zumindest annähernd parallel zum Zylinder 16 des Pumpenkörpers 14, kann jedoch auch geneigt zu diesem verlaufen. 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, beispielsweise ebenfalls etwa kegelförmigen Ventilsitz 36 zusammenwirkt, von dem oder nach dem die Einspritzöffnungen 32 abführen.The fuel injection valve 12 has a valve body 26 which can be constructed in several parts and which is connected to the pump body 14, for example with an intermediate body 27 interposed. A disk 15 can also be arranged between the intermediate body 27 and the pump body 14. An injection valve member 28 is guided in a longitudinally displaceable manner in a bore 30 in the valve body 26. The bore 30 runs at least approximately parallel to the cylinder 16 of the pump body 14, but can also run at an incline to the latter. The valve body 26 faces the combustion chamber of the cylinder of the internal combustion engine facing end region 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, for example, approximately conical sealing surface 34 which interacts with a valve seat 36, for example likewise approximately conical in the valve body 26 in its end region facing the combustion chamber, from or after which the injection openings 32 lead away.
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 zum Ventilsitz 36 weisende 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 durch eine Bohrung 47 gebildeten Federraum 46 des Zwischenkörpers 27 angeordnet, der sich an die Bohrung 30 anschließt. Der Federraum 46 ist vorzugsweise mit einem Entlastungsbereich, beispielsweise zumindest mittelbar dem Kraftstoffvorratsbehälter 24, verbunden. Der Druckraum 40 weist eine durch den Ventilkörper 26, den Zwischenkörper 27, die Scheibe 15 und den Pumpenkörper 14 verlaufende Verbindung 48 mit dem Pumpenarbeitsraum 22 auf. Die Verbindung 48 weist eine Länge 11 auf.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 passes through a radial expansion of the bore 30 into a pressure chamber 40 surrounding the injection valve member 28. The injection valve member 28 has a pressure shoulder 42 facing the valve seat 36 at the level of the pressure chamber 40 due to a reduction in cross section. At the end of the injection valve member 28 facing away from the combustion chamber, a prestressed closing spring 44 engages, by means of which the injection valve member 28 is pressed toward the valve seat 36. The closing spring 44 is arranged in a spring space 46 of the intermediate body 27 which is formed by a bore 47 and which adjoins the bore 30. The spring chamber 46 is preferably connected to a relief region, for example at least indirectly the fuel reservoir 24. The pressure chamber 40 has a connection 48 through the valve body 26, the intermediate body 27, the disk 15 and the pump body 14 to the pump working chamber 22. The connection 48 has a length 11.
Die Schließfeder 44 stützt sich einerseits zumindest mittelbar, beispielsweise über einen Federteller, am Einspritzventilglied 28 und andererseits zumindest mittelbar, beispielsweise ebenfalls über einen Federteller 51, an einem Speicherkolben 50 ab. Der Speicherkolben 50 ist in der den Federraum 46 bildenden Bohrung 47 dicht geführt und begrenzt mit seiner der Schließfeder abgewandten Stirnseite in der Bohrung 47 einen Speicherraum 52. Der Speicherraum 52 weist eine durch den Zwischenkörper 27, die Scheibe 15 und den Pumpenkörper 14 verlaufende Verbindung 54 mit dem Pumpenarbeitsraum 22 auf. Die Verbindung 54 weist eine Länge 12 auf. Um eine möglichst große Länge 12 der Verbindung 54 zu erreichen verläuft die Verbindung 54 nicht direkt auf kürzestem Weg zwischen dem Speicherraum 52 und dem Pumpenarbeitsraum 22 sondern weist wenigstens eine Umlenkung auf. Wie in Figur 2 dargestellt verläuft die Verbindung 54 ausgehend von dem der Scheibe 15 zugewandten Endbereich des Speicherraums 52 beispielsweise zunächst zumindest annähernd radial zur Längsachse des Zwischenkörpers 27, die gleich ist wie die Längsachse des Einspritzventilglieds 28, nach außen. Hierbei ist in der der Scheibe 15 zugewandten Stirnseite des Zwischenkörpers 27, oder alternativ in der dem Zwischenkörper 27 zugewandten Stirnseite der Scheibe 15, eine Nut 56 ausgebildet. Die Nut 56 wird durch die Scheibe 15 verschlossen, so daß ein geschlossener Kanal gebildet ist. An die Nut 56 schließt sich als weiterer Teil der Verbindung 54 eine Bohrung 58 im Zwischenkörper 27 an, die beispielsweise zumindest annähernd parallel zur Längsachse des Zwischenkörpers 27 verläuft. Die Bohrung 58 mündet auf der dem Ventilkörper 26 zugewandten Seite des Zwischenkörpers 27 in eine in der dem Ventilkörper 26 zugewendten Stirnseite des Zwischenkörpers 27 ausgebildete weitere Nut 60. Die Nut 60 kann alternativ auch in der dem Zwischenkörper 27 zugewandten Stirnseite des Ventilkörpers 26 ausgebildet sein. Die Nut 60 verläuft beispielsweise zumindest annähernd radial nach außen. Vom radial äußeren Ende der Nut 60 führt eine weitere Bohrung 62 durch den Zwischenkörper 27 ab, die beispielsweise zumindest annähernd parallel zur Bohrung 58 verläuft und die an der der Scheibe 15 zugewandten Stirnseite des Zwischenkörpers 27 mündet. In der Scheibe 15 und dem Pumpenkörper 14 schließen sich weitere Bohrungen als Teile der Verbindung 54 an. Die Länge 12 der Verbindung ist die Summe der Längen der Nuten 56,60, der Bohrungen 58,60 im Zwischenkörper 27 und der Bohrungen in der Scheibe 15 und dem Pumpenkörper 14 bis zum Pumpenarbeitsraum 22.The closing spring 44 is supported on the one hand at least indirectly, for example via a spring plate, on the injection valve member 28 and on the other hand at least indirectly, for example likewise via a spring plate 51, on a storage piston 50. The accumulator piston 50 is guided tightly in the bore 47 forming the spring space 46 and delimits a storage space 52 in the bore 47 with its end face remote from the closing spring. The storage space 52 has a connection 54 to the pump working space 22 which runs through the intermediate body 27, the disk 15 and the pump body 14 on. The connection 54 has a length 12. In order to achieve the greatest possible length 12 of the connection 54, the connection 54 does not run directly along the shortest route between the storage space 52 and the pump work space 22, but rather has at least one deflection. As shown in FIG. 2, the connection 54, starting from the end region of the storage space 52 facing the disk 15, initially extends at least approximately radially to the longitudinal axis of the intermediate body 27, which is the same as the longitudinal axis of the injection valve member 28. In this case, a groove 56 is formed in the end face of the intermediate body 27 facing the disk 15, or alternatively in the end face of the disk 15 facing the intermediate body 27. The groove 56 is closed by the disc 15, so that a closed channel is formed. As a further part of the connection 54, the groove 56 is followed by a bore 58 in the intermediate body 27, which for example runs at least approximately parallel to the longitudinal axis of the intermediate body 27. On the side of the intermediate body 27 facing the valve body 26, the bore 58 opens into a further groove 60 formed in the end face of the intermediate body 27 facing the valve body 26. The groove 60 can alternatively also be formed in the end face of the valve body 26 facing the intermediate body 27. The groove 60 extends, for example, at least approximately radially outwards. A further bore 62 leads from the radially outer end of the groove 60 through the intermediate body 27, which for example runs at least approximately parallel to the bore 58 and opens out on the end face of the intermediate body 27 facing the disk 15. Close in the disc 15 and the pump body 14 more holes as part of the connection 54. The length 12 of the connection is the sum of the lengths of the grooves 56.60, the bores 58.60 in the intermediate body 27 and the bores in the disk 15 and the pump body 14 up to the pump working space 22.
Erfindungsgemäß beträgt das Verhältnis λ der Länge 11 der Verbindung 48 des Druckraums 40 desAccording to the invention, the ratio λ of the length 11 of the connection 48 of the pressure chamber 40 is
Kraftstoffeinspritzventils 12 mit dem Pumpenarbeitsraum 22 geteilt durch die Länge 12 der Verbindung 54 des Speicherraums 52 mit dem Pumpenarbeitsraum 22 zwischen 1,5 und 4. Das Verhältnis λ beträgt insbesondere zwischen 2 und 2,5, vorzugsweise zumindest annähernd 2,1. Die Länge 11 der Verbindung 48 des Druckraums 40 desFuel injection valve 12 with the pump working space 22 divided by the length 12 of the connection 54 of the storage space 52 with the pump working space 22 between 1.5 and 4. The ratio λ is in particular between 2 and 2.5, preferably at least approximately 2.1. The length 11 of the connection 48 of the pressure chamber 40 of the
Kraftstoffeinspritzventils 12 mit dem Pumpenarbeitsraum 22 ist konstruktiv durch den Aufbau derFuel injection valve 12 with the pump work chamber 22 is constructive through the construction of the
Kraftstoffeinspritzeinrichtung vorgegeben und kann daher nicht beliebig verringert werden.Fuel injection device specified and can therefore not be reduced arbitrarily.
Nachfolgend wird die Funktion der Kraftstoffeinspritzeinrichtung erläutert. Der Pumpenarbeitsraum 22 wird während des Saughubs des Pumpenkolbens 18 mit Kraftstoff gefüllt. Beim Förderhub des Pumpenkolbens 18 ist das Steuerventil 23 zunächst geöffnet, so daß sich im Pumpenarbeitsraum 22 kein Hochdruck aufbauen kann. Wenn die Kraftstoffeinspritzung beginnen soll, so wird das Steuerventil 23 durch die Steuereinrichtung 25 geschlossen, so daß der Pumpenarbeitsraum 22 vom Kraftstoffvorratsbehälter 24 getrennt ist und sich in diesem Hochdruck aufbaut. Wenn der Druck im Pumpenarbeitsraum 22 und im Druckraum 40 so hoch ist, daß die über die Druckschulter 42 auf das Einspritzventilglied 28 wirkende Kraft in Öffnungsrichtung 29 größer ist als die Kraft der Schließfeder 44, so bewegt sich das Einspritzventilglied 28 in Öffnungsrichtung 29 und gibt die wenigstens eine Einspritzöffnung 32 frei, durch die Kraftstoff in den Brennraum des Zylinders eingespritzt wird. Der Speicherkolben 50 befindet sich hierbei in einer Ausgangsstellung, in der dieser am nächsten zur Scheibe 15 angeordnet ist. Der Druck im Pumpenarbeitsraum 22 steigt nachfolgend entsprechend dem Profil des Nockens 20 weiter an.The function of the fuel injection device is explained below. The pump working chamber 22 is filled with fuel during the suction stroke of the pump piston 18. During the delivery stroke of the pump piston 18, the control valve 23 is initially open, so that no high pressure can build up in the pump work chamber 22. When the fuel injection is to begin, the control valve 23 is closed by the control device 25, so that the pump working space 22 is separated from the fuel reservoir 24 and builds up in this high pressure. If the pressure in the pump working chamber 22 and in the pressure chamber 40 is so high that the force acting on the injection valve member 28 via the pressure shoulder 42 in the opening direction 29 is greater than the force of the closing spring 44, the injection valve member 28 moves in the opening direction 29 and gives the at least one injection port 32 through which fuel into the Combustion chamber of the cylinder is injected. The storage piston 50 is in a starting position in which it is arranged closest to the disk 15. The pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam 20.
Wenn die durch den im Pumpenarbeitsraum 22 herrschenden Druck auf den Speicherkolben 50 ausgeübte Kraft großer wird als die durch die Schließfeder 44 auf den Speicherkolben 50 ausgeübte Kraft, so fuhrt der Speicherkolben 50 eine Ausweichhubbewegung aus und bewegt sich von der Scheibe 15 weg in den Federraum 46 hinein, wobei der Speicherraum 52 vergrößert wird. Hierbei wird ein Druckabfall im Pumpenarbeitsraum 22 verursacht und außerdem die Vorspannung der Schließfeder 44 erhöht, die sich am Speicherkolben 50 abstutzt. Durch den Druckabfall im Pumpenarbeitsraum 22 und im Druckraum 40 ergibt sich eine geringere Kraft in Offnungsrichtung 29 auf das Einspritzventilglied 28 und infolge der Erhöhung der Vorspannung der Schließfeder 44 ergibt sich eine erhöhte Kraft in Schließrichtung auf das Einspritzventilglied 28, so daß dieses wieder in Schließrichtung bewegt wird, mit seiner Dichtflache 34 am Ventilsitz 36 zur Anlage kommt und die Einspritzoffnungen 32 verschließt, so daß die Kraftstoffeinspritzung unterbrochen wird. Das Kraftstoffeinspritzventil 12 ist dabei nur für eine kurze Zeitdauer geöffnet und es wird nur eine geringe Menge Kraftstoff als Voreinspritzung in den Brennraum eingespritzt. In Figur 3 ist der Offnungshub des Einspritzventilglieds 28 über der Zeit wahrend eines Einspritzzyklus dargestellt, wobei der Hub bei der Voreinspritzung in Figur 3 mit I bezeichnet ist. Die eingespritzte Kraftstoffmenge ist im wesentlichen vom Offnungsdruck des Speicherkolbens 50 bestimmt, das ist der Druck im Pumpenarbeitsraum 22, bei dem der Speicherkolben 50 seine Ausweichhubbewegung beginnt. Durch das Schließen des Steuerventils 23 beim Förderhub des Pumpenkolbens 18 werden Druckwellen verursacht, die sich vom Pumpenarbeitsraum 22 über die Verbindung 48 zum Druckraum 40 und über die Verbindung 54 zum Speicherraum 52 ausbreiten. Durch die vorstehend erläuterte Wahl der Länge 11 der Verbindung 48 und der Länge 12 der Verbindung 54 zur Erzielung des Verhältnisses λ im angegebenen Bereich sind die Laufzeiten der Druckwellen in den Verbindungen 48 und 54 derart aufeinander abgestimmt, daß bei unterschiedlichen Betriebsbedingungen, insbesondere unterschiedlichen Drehzahlen der Brennkraftmaschine, jeweils eine optimale Kraftstoffeinspritzmenge bei der Voreinspritzung erreicht wird.If the force exerted on the accumulator piston 50 by the pressure prevailing in the pump work chamber 22 becomes greater than the force exerted on the accumulator piston 50 by the closing spring 44, the accumulator piston 50 performs an evasive stroke movement and moves away from the disk 15 into the spring chamber 46 into it, with the storage space 52 being enlarged. This causes a pressure drop in the pump work chamber 22 and also increases the pretension of the closing spring 44, which is supported on the accumulator piston 50. The pressure drop in the pump working chamber 22 and in the pressure chamber 40 results in a lower force in the opening direction 29 on the injection valve member 28 and, due to the increase in the pretension of the closing spring 44, there is an increased force in the closing direction on the injection valve member 28 so that it moves again in the closing direction is, with its sealing surface 34 comes to rest on the valve seat 36 and closes the injection openings 32 so that the fuel injection is interrupted. The fuel injection valve 12 is only open for a short period of time and only a small amount of fuel is injected into the combustion chamber as a pre-injection. FIG. 3 shows the opening stroke of the injection valve member 28 over time during an injection cycle, the stroke for the pre-injection being designated I in FIG. The amount of fuel injected is essentially determined by the opening pressure of the accumulator piston 50, that is the pressure in the pump working chamber 22 at which the accumulator piston 50 begins its evasive stroke movement. By closing the Control valve 23 during the delivery stroke of the pump piston 18 causes pressure waves which propagate from the pump working chamber 22 via the connection 48 to the pressure chamber 40 and via the connection 54 to the storage chamber 52. Through the selection of the length 11 of the connection 48 and the length 12 of the connection 54 explained above to achieve the ratio λ in the specified range, the transit times of the pressure waves in the connections 48 and 54 are coordinated with one another in such a way that under different operating conditions, in particular different speeds of the Internal combustion engine, in each case an optimal fuel injection quantity is reached during the pre-injection.
Der Öffnungshub des Einspritzventilglieds 28 während der Voreinspritzung kann durch eine Dämpfungseinrichtung hydraulisch begrenzt sein. Eine solche Dämpfungseinheit ist durch die DE 39 00 762 AI sowie die korrespondierende US- 5,125,580 sowie die DE 39 00 763 AI sowie die korrespondierende US-5,125,581 bekannt, auf deren Inhalt hiermit ausdrücklich Bezug geommen wird.The opening stroke of the injection valve member 28 during the pre-injection can be hydraulically limited by a damping device. Such a damping unit is known from DE 39 00 762 AI and the corresponding US Pat. No. 5,125,580 and DE 39 00 763 AI and the corresponding US Pat. No. 5,125,581, the contents of which are hereby expressly incorporated by reference.
Der Druck im Pumpenarbeitsraum 22 steigt nachfolgend weiter an entsprechend dem Profil des Nockens 20, so daß die auf das Einspritzventilglied 28 wirkende Druckkraft in Öffnungsrichtung 29 wieder zunimmt und die infolge der erhöhten Vorspannung der Schließfeder 44 erhöhte Schließkraft übersteigt, so daß dasThe pressure in the pump working chamber 22 subsequently rises further in accordance with the profile of the cam 20, so that the pressure force acting on the injection valve member 28 increases again in the opening direction 29 and increases the closing force due to the increased preload of the closing spring 44, so that the
Kraftstoffeinspritzventil 12 wieder öffnet. Dabei wird eine größere Kraftstoffmenge über eine längere Zeitdauer eingespritzt als während der Voreinspritzung. Der Hub des Einspritzventilglieds 28 während der Haupteinspritzung ist in Figur 3 mit II bezeichnet. Die Zeitdauer und die während dieser Haupteinspritzung eingespritzte Kraftstoffmenge werden durch den Zeitpunkt bestimmt, zu dem das Steuerventil 23 durch die Steuereinrichtung 25 wieder geöffnet wird. Nach - lo ¬Fuel injection valve 12 opens again. A larger amount of fuel is injected over a longer period of time than during the pre-injection. The stroke of the injection valve member 28 during the main injection is designated II in FIG. 3. The time period and the amount of fuel injected during this main injection are determined by the point in time at which the control valve 23 is opened again by the control device 25. To - lo ¬
dern Öffnen des Steuerventils 23 ist der Pumpenarbeitsraum 22 wieder mit dem Kraftstoffvorratsbehälter 24 verbunden, so daß dieser entlastet ist und das Kraftstoffeinspritzventil 12 schließt. Der Speicherkolben 50 wird durch die Kraft der Schließfeder 44 wieder in seine Ausgangsstellung zurückbewegt. Der zeitliche Versatz zwischen der Voreinspritzung und der Haupteinspritzung ist hauptsächlich durch den Ausweichhub des Speicherkolbens 50 bestimmt. When the control valve 23 is opened, the pump working chamber 22 is connected again to the fuel reservoir 24, so that the latter is relieved and the fuel injection valve 12 closes. The storage piston 50 is moved back into its starting position by the force of the closing spring 44. The time offset between the pilot injection and the main injection is mainly determined by the evasive stroke of the accumulator piston 50.

Claims

Ansprüche Expectations
1. Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine mit einer Kraftstoffhochdruckpumpe (10) und einem Kraftstoffeinspritzventil (12) für einen Zylinder der Brennkraftmaschine, wobei die Kraftstoffhochdruckpumpe1. Fuel injection device for an internal combustion engine with a high-pressure fuel pump (10) and a fuel injection valve (12) for a cylinder of the internal combustion engine, the high-pressure fuel pump
(10) einen durch die Brennkraftmaschine angetriebenen, einen Pumpenarbeitsraum (22) begrenzenden Pumpenkolben (18) aufweist, mit einem elektrisch betätigten Steuerventil (23) , durch das zumindest mittelbar eine Verbindung des Pumpenarbeitsraums (22) mit einem Entlastungsbereich (24) gesteuert wird, wobei das Kraftstoffeinspritzventil (12) wenigstens ein Einspritzventilglied (28) aufweist, durch das wenigstens eine Einspritzöffnung (32) gesteuert wird und das durch den in einem eine Verbindung (48) mit dem Pumpenarbeitsraum (22) aufweisenden Druckraum (40) herrschenden Druck gegen die Kraft einer in einem Federraum(10) has a pump piston (18) driven by the internal combustion engine and delimiting a pump work chamber (22), with an electrically operated control valve (23), by means of which a connection of the pump work chamber (22) to a relief region (24) is controlled at least indirectly, wherein the fuel injection valve (12) has at least one injection valve member (28) through which at least one injection opening (32) is controlled and which is opposed by the pressure prevailing in a pressure chamber (40) having a connection (48) to the pump working chamber (22) Force one in a spring chamber
(46) angeordneten Schließfeder (44) in einer Öffnungsrichtung (29) bewegbar ist, wobei sich die Schließfeder (44) einerseits zumindest mittelbar am Einspritzventilglied (28) und andererseits zumindest mittelbar an einem verschiebbaren Speicherkolben (50) abstützt, der auf seiner der Schließfeder (44) abgewandten Seite einen eine Verbindung (54) mit dem Pumpenarbeitsraum(46) arranged closing spring (44) is movable in an opening direction (29), the closing spring (44) on the one hand being supported at least indirectly on the injection valve member (28) and on the other hand at least indirectly on a displaceable storage piston (50) which rests on the closing spring (44) facing away from a connection (54) with the pump work space
(22) aufweisenden Speicherraum (52) begrenzt und der durch den im Speicherraum (52) herrschenden Druck beaufschlagt gegen die Kraft der Schließfeder (44) in den Federraum (46) bewegbar ist, dadurch gekennzeichnet, daß das Verhältnis (λ) der Länge (11) der Verbindung (48) des Druckraums (40) mit dem Pumpenarbeitsraum (22) geteilt durch die Länge (12) der Verbindung (54) des Speicherraums (52) mit dem Pumpenarbeitsraum (22) zwischen 1,5 und 4 beträgt. (22) having a storage space (52) and which can be moved against the force of the closing spring (44) into the spring space (46) by the pressure prevailing in the storage space (52), characterized in that the ratio (λ) of the length ( 11) the connection (48) of the pressure chamber (40) to the pump work chamber (22) divided by the length (12) of the connection (54) of the storage chamber (52) to the pump work chamber (22) is between 1.5 and 4.
2. Kraftstoffeinspritzeinrichtung nach Anspruch 1, dadurch gekennzeichnet, daß das Verhältnis (λ) zwischen 2 und 2,5, vorzugsweise zumindest annähernd 2,1 beträgt.2. Fuel injection device according to claim 1, characterized in that the ratio (λ) is between 2 and 2.5, preferably at least approximately 2.1.
3. Kraftstoffeinspritzeinrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Kraftstoffhochdruckpumpe (10) einen Pumpenkörper (14) und das3. Fuel injection device according to claim 1 or 2, characterized in that the high-pressure fuel pump (10) has a pump body (14) and the
Kraftstoffeinspritzventil (12) einen Ventilkörper (26) aufweist, die unter Zwischenlage wenigstens eines Zwischenkörpers (27) miteinander verbunden sind, daß der Speicherraum (52) im Zwischenkörper (27) ausgebildet ist und daß die Verbindung (54) des Speicherraums (52) mit dem Pumpenarbeitsraum (22) zumindest teilweise durch den Zwischenkörper (27) verläuft.Fuel injection valve (12) has a valve body (26) which are connected to one another with the interposition of at least one intermediate body (27), that the storage space (52) is formed in the intermediate body (27) and that the connection (54) of the storage space (52) with the pump working space (22) runs at least partially through the intermediate body (27).
4. Kraftstoffeinspritzeinrichtung nach Anspruch 3, dadurch gekennzeichnet, daß die Verbindung (54) des Speicherraums (52) mit dem Pumpenarbeitsraum (22) im Zwischenkörper (27) wenigstens eine Umlenkung zur Verlängerung der Verbindung4. Fuel injection device according to claim 3, characterized in that the connection (54) of the storage space (52) with the pump working space (22) in the intermediate body (27) at least one deflection for extending the connection
(54) aufweist. (54).
PCT/DE2003/001580 2002-07-20 2003-05-15 Fuel-injection device for an internal combustion engine WO2004016935A1 (en)

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DE10233101.4 2002-07-20
DE2002133101 DE10233101A1 (en) 2002-07-20 2002-07-20 Fuel injection device for an internal combustion engine

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Publication number Priority date Publication date Assignee Title
US8695899B2 (en) 2008-07-29 2014-04-15 Continental Automotive Gmbh Fuel injector

Families Citing this family (1)

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Publication number Priority date Publication date Assignee Title
EP1921307B1 (en) 2006-11-08 2012-08-15 Delphi Technologies Holding S.à.r.l. Fuel injection system

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DE3900763A1 (en) * 1989-01-12 1990-07-19 Voest Alpine Automotive Fuel injection nozzle
DE3900762A1 (en) * 1989-01-12 1990-07-19 Voest Alpine Automotive Fuel injection nozzle with a hollow yielding piston
US6227175B1 (en) * 1999-12-27 2001-05-08 Detroit Diesel Corporation Fuel injector assembly having a combined initial injection and a peak injection pressure regulator
DE10000384A1 (en) * 2000-01-07 2001-07-12 Volkswagen Ag Damper for fuel injection pressure fluctuations comprises variable volume body or elastic layer or fuelproofly sheathed body or air volume directly at pump intake for immediate pressure smoothing.
EP1213476A2 (en) * 2000-12-05 2002-06-12 Caterpillar Inc. Common rail injector with separately controlled pilot and main injection
DE10062896A1 (en) * 2000-12-16 2002-06-20 Bosch Gmbh Robert Fuel injection device for an internal combustion engine
DE10116635A1 (en) * 2001-04-04 2002-10-17 Bosch Gmbh Robert Method for operating a unit injector and unit injector
US20030106948A1 (en) * 2001-12-07 2003-06-12 Robert Bosch Gmbh Fuel injection system for an internal combustion engine

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US4913113A (en) * 1989-01-09 1990-04-03 Baranescu George S Internal combustion engine with fuel tolerance and low emissions
DE3900763A1 (en) * 1989-01-12 1990-07-19 Voest Alpine Automotive Fuel injection nozzle
DE3900762A1 (en) * 1989-01-12 1990-07-19 Voest Alpine Automotive Fuel injection nozzle with a hollow yielding piston
US6227175B1 (en) * 1999-12-27 2001-05-08 Detroit Diesel Corporation Fuel injector assembly having a combined initial injection and a peak injection pressure regulator
DE10000384A1 (en) * 2000-01-07 2001-07-12 Volkswagen Ag Damper for fuel injection pressure fluctuations comprises variable volume body or elastic layer or fuelproofly sheathed body or air volume directly at pump intake for immediate pressure smoothing.
EP1213476A2 (en) * 2000-12-05 2002-06-12 Caterpillar Inc. Common rail injector with separately controlled pilot and main injection
DE10062896A1 (en) * 2000-12-16 2002-06-20 Bosch Gmbh Robert Fuel injection device for an internal combustion engine
DE10116635A1 (en) * 2001-04-04 2002-10-17 Bosch Gmbh Robert Method for operating a unit injector and unit injector
US20030106948A1 (en) * 2001-12-07 2003-06-12 Robert Bosch Gmbh Fuel injection system for an internal combustion engine

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8695899B2 (en) 2008-07-29 2014-04-15 Continental Automotive Gmbh Fuel injector

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