EP1397591A1 - Fuel injection device comprising a pressure amplifier - Google Patents

Fuel injection device comprising a pressure amplifier

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Publication number
EP1397591A1
EP1397591A1 EP02745063A EP02745063A EP1397591A1 EP 1397591 A1 EP1397591 A1 EP 1397591A1 EP 02745063 A EP02745063 A EP 02745063A EP 02745063 A EP02745063 A EP 02745063A EP 1397591 A1 EP1397591 A1 EP 1397591A1
Authority
EP
European Patent Office
Prior art keywords
pressure
fuel
piston
injection device
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP02745063A
Other languages
German (de)
French (fr)
Other versions
EP1397591B1 (en
Inventor
Wolfgang Braun
Bernd Mahr
Martin Kropp
Hans-Christoph Magel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1397591A1 publication Critical patent/EP1397591A1/en
Application granted granted Critical
Publication of EP1397591B1 publication Critical patent/EP1397591B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/12—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
    • 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
    • F02M57/025—Injectors structurally combined with fuel-injection pumps characterised by the pump drive hydraulic, e.g. with pressure amplification

Definitions

  • the invention relates to a fuel injection device according to the preamble of patent claim 1.
  • the fuel injection device according to the invention can be designed both stroke-controlled and pressure-controlled. In the context of the invention is under 'a stroke controlled
  • Fuel einspritzeinrichtunq understood that the 'opens and closes the injection port • by means of a displaceable nozzle needle due to the hydraulic interaction of the fuel pressures in a nozzle chamber and a control chamber. A pressure drop within the control room causes the nozzle needle to lift.
  • the nozzle needle can be deflected by an actuator (actuator, actuator).
  • the nozzle needle is moved by the fuel pressure prevailing in the nozzle chamber of an injector against the action of a closing force (spring), so that the injection opening is released for an injection of fuel from the nozzle chamber into the cylinder.
  • injection pressure The pressure at which fuel emerges from the nozzle chamber into a cylinder of an internal combustion engine
  • system pressure is understood to mean the pressure at which fuel is available or is stored within the fuel injection device.
  • Fuel metering means providing a defined amount of fuel for injection. Leakage is to be understood as an amount of fuel that arises during operation of the fuel injection device (for example a guide leakage), is not used for injection and is returned to the fuel tank. The pressure level of this leakage can have a static pressure, the fuel then being expanded to the pressure level of the fuel tank. Many engine manufacturers require a flat pressure rise edge at the start of injection. Often a boot phase to reduce emissions is also desired.
  • the pressure booster can be used to shape the course of the injection.
  • the desired injection course can without additional parts such as A realize 'usweichkolben.
  • the movement of the piston of the pressure booster can be used to influence the pressure curve.
  • the stroke-dependent influencing of the inlet cross section to the pressure booster chamber on the low pressure side is known from US Pat. No. 5,568,31 7.
  • the US PS proposes a multi-stage control of the inlet cross section.
  • a fuel injection device To influence the fuel pressure during the injection and to achieve a flat pressure rise without disturbing pressure vibrations, a fuel injection device according to claim .1 is proposed. As the piston stroke increases, a larger cross section and thus a larger injection quantity is released, so that a stepless configuration of the injection course is possible.
  • Figure 1 shows a first continuous cross-sectional change of the inlet or outlet to a space of a pressure booster in a fuel injection device.
  • Fig. 2 shows a second continuous change in cross section of the inlet or
  • Fig. 3 shows a stroke-controlled fuel injection device with a
  • a mengengeregel promotes' te fuel pump 2 fuel from a storage tank via a feed pipe in a central pressure accumulator (common rail) 2 '', corresponding one of the plurality of the number of individual cylinder pressure lines 2 lead to the individual injectors 3 (injection device) projecting into the combustion chamber of the internal combustion engine to be supplied. Only one of the injectors 3 is shown in FIG. 1. With the help of the fuel pump 2 ', a first system pressure is generated and stored in the pressure storage chamber 2'.
  • This first system pressure is used for pre-injection and, if necessary, for post-injection (HC enrichment for exhaust gas aftertreatment or soot reduction) as well as for displaying an injection course with plateau (boat injection).
  • each injector 3 is assigned a local pressure booster 4 with a check valve 5 and with a displaceable piston 6.
  • Such fuel injection devices are known for example from DE-A1 - 19910970.
  • the pressure in the differential space 7 formed by a transition from a larger to a smaller piston cross-section is used to control the pressure booster 4.
  • the differential space 7 is supplied with a supply pressure (rail pressure). Then the same pressure conditions (rail pressure) prevail on all pressure surfaces of a piston 6.
  • the piston 6 is pressure balanced. With an additional spring 8 the piston 6 is pressed into its starting position.
  • the differential space 7 is relieved of pressure and the pressure amplifier 4 generates a pressure gain in accordance with the area ratio.
  • a throttle 1 1 and. simple 2/2-way valve 1 2 can be used.
  • the throttle 1 1 connects the '' differential space 7 with fuel under supply pressure from the pressure storage space 2 ''.
  • the 2/2-way valve 12 connects the differential chamber 7 to a leakage line 13.
  • the throttle 1 1 should be designed as small as possible, but still so large that " the piston 6 returns to its starting position between the injection cycles.
  • a guide leakage of the piston 6 can also be used as a throttle. With the 2/2-way valve 1 closed 2 there is no leakage in the guides of the piston 6, since the differential space 7 is pressurized, the throttle can also be integrated in the piston.
  • the injector 3 is under the pressure of the pressure storage space 2. ' '
  • the pressure booster 4 is in the starting position. Now an injection with rail pressure can take place through the valve 14. If an injection with a higher pressure is desired, the 2/2-way valve 12 is activated (opened) and thus a pressure increase is achieved.
  • the injection takes place via a fuel metering. with the aid of a nozzle needle 15 which is axially displaceable in a guide bore and has a conical valve sealing surface at one end, with which it cooperates with a valve seat surface on the injector housing of the injector 3. Injection openings are provided on the valve seat surface of the injector housing.
  • a pressure surface pointing in the opening direction of the nozzle needle 15 is there exposed to prevailing pressure, which is supplied to the nozzle chamber 16 via a pressure line.
  • a pressure piece 18 also acts on the nozzle needle 15, which delimits the control chamber 19 with its end face facing away from the valve sealing surface.
  • the control chamber 1 9 has an inlet with a first throttle and an outlet to the leakage line 13, which is controlled by the 2/2-way valve 14, from the fuel pressure connection.
  • Fuel under the first or second system pressure constantly fills the nozzle chamber 16 and the control chamber 19.
  • the pressure in the control chamber 1 9 can be reduced, so that the in Opening direction on the nozzle needle 1 5 pressure force in the nozzle chamber 16 exceeds the pressure force acting in the closing direction on the nozzle needle 15.
  • the valve sealing surface lifts off the valve seat surface and fuel is injected.
  • the pressure relief operation can be influenced via the Dime ⁇ sion réelle the throttles of the control chamber 9 and 1 'thus the stroke control of the nozzle needle 1. 5
  • the end of the injection is initiated by actuating (closing) the 2/2-way valve 1 again, which decouples the control chamber 19 from the leakage line 1 3, so that a pressure builds up again in the control chamber 1 9, which pressure element 1 8 can move in the closing direction.
  • the inlet to the pressure intensifier space 10 on the low-pressure side and / or the outlet from the differential space 7 is provided with a continuous cross-sectional enlargement.
  • a flat rise in pressure can be achieved without disturbing pressure fluctuations.
  • only a partial surface 25 of a slot-shaped opening 26 up to a control edge 24 ' is released by the direction of movement 23 of a piston 24 (longitudinal direction of the opening and the piston) and a partial surface 27 of the opening 26 is covered.
  • the opening 26 in the wall surface of a pressure booster chamber (differential chamber or low-pressure chamber) connects the differential chamber 7 (see FIG.
  • a slot-shaped opening 28 in the wall surface of a pressure booster chamber has a cross-sectional area that is variable in the direction of movement 29 of the piston 30.
  • the piston 30 itself has a recess 31, which establishes the continuous connection of the differential space 7 (see FIG. 1) to the leakage line or the connection between the low-pressure space 10 and the pressure line 2.
  • the recess 31 forms a kind of control window that slides along the slot 28.
  • slot-shaped opening 28 can also be formed in the piston and the control edge 24 '... Or a recess '31 in the wall surface.

Landscapes

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

Abstract

The invention relates to a fuel injection device comprising a pressure amplifier. The pressure amplifier comprises a moving piston (24), for compressing the fuel for supply to an injector in a high-pressure side pressure amplification chamber and which may be pressurised by means of a low-pressure side pressure amplification chamber. The stroke of the piston is essentially controllable by means of the pressure in a difference chamber in the pressure amplifier and is used to control the fuel pressure supplied to the injector. Means (24, 25) are provided for the stepless embodiment of the inlet cross-section on the low-pressure side pressure amplification chamber of the pressure amplifier, or of the outlet cross-section from the difference chamber of the pressure amplifier.

Description

Kraftstoffeinspritzeinrichtung mit Druckverstärker Fuel injector with pressure booster
B E S C H R E I B U IM GB E S C H R E I B U IM G
Stand der TechnikState of the art
Die Erfindung betrifft eine Kraftstoffeinspritzeinrichtung gemäß dem Oberbegriff des Patentanspruchs 1 .The invention relates to a fuel injection device according to the preamble of patent claim 1.
Zum besseren Verständnis der Beschreibung und der Patentansprüche werden nachfolgend einige Begriffe erläutert: Die Kraftstoffeinspritzeinrichtung gemäß der Erfindung kann sowohl hubgesteuert als auch druckgesteuert ausgebildet sein. Im Rahmen der Erfindung wird unter' einer hubgesteuerteriFor a better understanding of the description and the patent claims, some terms are explained below: The fuel injection device according to the invention can be designed both stroke-controlled and pressure-controlled. In the context of the invention is under 'a stroke controlled
Kraftstoff einspritzeinrichtunq verstanden, dass das' Öffnen und Schließen der • Einspritzöffnung mit Hilfe einer verschiebbaren Düsennadel aufgrund des hydraulischen Zusammenwirkens der Kraftstoffdrücke in einem Düsenraum und in einem Steuerraum erfolgt. Eine Druckabsenkung innerhalb des Steue raums bewirkt einen Hub der Düsennadel. Alternativ kann das Auslenken der Düsennadel durch ein Stellglied (Aktor, Aktuator) erfolgen. Bei einer druckgesteuerten Kraftstoff einspritzeinrichtung gemäß der Erfindung wird die Düsennadel durch den im Düsenraum eines Injektors herrschenden Kraftstoffdruck gegen die Wirkung einer Schließkraft (Feder) bewegt, so dass die Einspritzöffnung für eine Einspritzung des Kraftstoffs aus dem Düsenraum in den Zylinder freigegeben wird. Der Druck, mit dem Kraftstoff aus dem Düsenraum in einen Zylinder einer Brennkraftmaschine austritt, wird als Einspritzdruck bezeichnet, während unter einem Systemdruck der Druck verstanden wird, unter dem Kraftstoff innerhalb der Kraftstoffeinspritzeinrichtung zur Verfügung steht bzw. bevorratet ist. Kraftstoff zumessung bedeutet, eine definierte Kraftstoffmenge zur Einspritzung bereitzustellen. Unter Leckage ist eine Menge an Kraftstoff zu verstehen, die beim Betrieb der Kraftstoffeinspritzeinrichtung entsteht (z.B. eine Führungsleckage), nicht zur Einspritzung verwendet und zum Kraftstofftank zurückgefördert wird. Das Druckniveau dieser Leckage kann einen Standdruck aufweisen, wobei der Kraftstoff anschließend auf das Druckniveau des Kraftstofftanks entspannt wird. Viele Motorenhersteller fordern eine flache Druckanstiegsflanke zu Beginn der Einspritzung. Oftmals wird auch eine Bootphase zur Reduktion - von Emissionen gewünscht. Bei Kraftstoffeinspritzeinrichtungen mit Druckverst rker, wie sie beispielsweise aus der DE-A1 -1 991 0970 bekannt sind, kann der Druckverst rker zur Formung des Einspritzverlaufs verwendet werden. So lässt sich der gewünschte Einspritzverlauf ohne zusätzliche Teile, wie z.B. A'usweichkolben realisieren. Zur Beeinflussung des Druckverlaufs kann dabei die Bewegung des Kolbens des Druckverst rkers genutzt werden. Die hubabhängige Beeinflussung des Zulaufquerschnitts zum niederdruckseitigen Druckverstarkerraum ist aus der US-PS 5,568,31 7 bekannt. Durch die US-PS wird eine mehrstufige Steueru ng des Zulauf querschnitts vorgeschlagen.Fuel einspritzeinrichtunq understood that the 'opens and closes the injection port • by means of a displaceable nozzle needle due to the hydraulic interaction of the fuel pressures in a nozzle chamber and a control chamber. A pressure drop within the control room causes the nozzle needle to lift. Alternatively, the nozzle needle can be deflected by an actuator (actuator, actuator). In a pressure-controlled fuel injection device according to the invention, the nozzle needle is moved by the fuel pressure prevailing in the nozzle chamber of an injector against the action of a closing force (spring), so that the injection opening is released for an injection of fuel from the nozzle chamber into the cylinder. The pressure at which fuel emerges from the nozzle chamber into a cylinder of an internal combustion engine is referred to as injection pressure, while a system pressure is understood to mean the pressure at which fuel is available or is stored within the fuel injection device. Fuel metering means providing a defined amount of fuel for injection. Leakage is to be understood as an amount of fuel that arises during operation of the fuel injection device (for example a guide leakage), is not used for injection and is returned to the fuel tank. The pressure level of this leakage can have a static pressure, the fuel then being expanded to the pressure level of the fuel tank. Many engine manufacturers require a flat pressure rise edge at the start of injection. Often a boot phase to reduce emissions is also desired. In the case of fuel injection devices with pressure boosters, as are known, for example, from DE-A1-1 991 0970, the pressure booster can be used to shape the course of the injection. Thus the desired injection course can without additional parts such as A realize 'usweichkolben. The movement of the piston of the pressure booster can be used to influence the pressure curve. The stroke-dependent influencing of the inlet cross section to the pressure booster chamber on the low pressure side is known from US Pat. No. 5,568,31 7. The US PS proposes a multi-stage control of the inlet cross section.
Vorteile der ErfindungAdvantages of the invention
Zur Beeinflussung des Kraftstoffdrucks während der Einspritzung und zur Erzielung eines flachen Druckanstiegs ohne störende Druckschwingungen wird eine Kraftstoffeinspritzeinrichtung gemäß Patentanspruch .1 vorgeschlagen. Mit zunehmendem Kolbenhub wird ein größerer Querschnitt und somit eine größere Einspritzmenge freigegeben, so dass eine stufenlose Gestaltung des Einspitzverlaufs möglich wird.To influence the fuel pressure during the injection and to achieve a flat pressure rise without disturbing pressure vibrations, a fuel injection device according to claim .1 is proposed. As the piston stroke increases, a larger cross section and thus a larger injection quantity is released, so that a stepless configuration of the injection course is possible.
Zeichnungdrawing
Zwei Ausführungsbeispiele der erfindungsgemäßen Kraftstoffeinspritzeinrichtung sind in der schematischen Zeichnung dargestellt und werden in der nachfolgenden Beschreibung erläutert. Es zeigen:Two exemplary embodiments of the fuel injection device according to the invention are shown in the schematic drawing and are explained in the description below. Show it:
Fig. 1 eine erste stufenlose Querschnittsänderung des Zulaufs oder Ablaufs zu einem Raum eines Druckverstärkers bei einer Kraftstoff einspritzeinrichtung; Fig. 2 eine zweite stufenlose Querschnittsänderung des Zulaufs oderFigure 1 shows a first continuous cross-sectional change of the inlet or outlet to a space of a pressure booster in a fuel injection device. Fig. 2 shows a second continuous change in cross section of the inlet or
Ablaufs zu einem Raum eines Druckverstärkers bei einer Kraftstoff einsprit∑einrichtung;Sequence to a space of a pressure booster in a fuel injection device;
Fig. 3 eine hubgesteuerte Kraftstoffeinspritzeinrichtung mit einemFig. 3 shows a stroke-controlled fuel injection device with a
Druckverst rker nach dem Stand der Technik.State-of-the-art pressure booster.
Beschreibung der AusführungsbeispieieDescription of the execution examples
Bei der in der Fig. 3 dargestellten bekannten hubgesteuerteπ KFaftstoffeinspritzeinrichtung 1 fördert eine mengengeregel'te Kraftstoffpumpe 2 Kraftstoff aus einem Vorratstank über eine Förderleitung in einen zentralen Druckspeicherraum (Common-Rail) 2' ' , von dem mehrere, der Anzahl einzelner Zylinder entsprechende Druckleitungen 2 zu den einzelnen, in den Brennraum der zu versorgenden Brennkraftmaschine ragenden Injektoren 3 (Einspritzvorrichtung) abführen. In der Fig. 1 ist lediglich einer der Injektoren 3 eingezeichnet. Mit Hilfe der Kraftstoffpumpe 2 ' wird ein erster Systenidruck erzeugt und im Druckspeicherraum 2 ' gelagert, Dieser erste Systemdruck wird zur Voreinspritzung und bei Bedarf zur Nacheinspritzung (HC-Anreicherung zur Abgasnachbehandlung oder Rußreduktion) sowie zur Darstellung eines Einspritzverlaufs mit Plateau (Bootinjektion) verwendet. Zur Einspritzung von Kraftstoff mit einem zweiten höheren Systemdruck ist jedem Injektor 3 jeweils ein lokaler Druckverstärker 4 mit einem Rückschlagventil 5 und mit einem verschieblichen Kolben 6 zugeordnet. Derartige Kraftstoffeinspritzeinrichtungen sind beispielsweise aus der DE-A1 - 19910970 bekannt.When in the Fig. Illustrated known hubgesteuerteπ KFaftstoffeinspritzeinrichtung 1 3 a mengengeregel promotes' te fuel pump 2 fuel from a storage tank via a feed pipe in a central pressure accumulator (common rail) 2 '', corresponding one of the plurality of the number of individual cylinder pressure lines 2 lead to the individual injectors 3 (injection device) projecting into the combustion chamber of the internal combustion engine to be supplied. Only one of the injectors 3 is shown in FIG. 1. With the help of the fuel pump 2 ', a first system pressure is generated and stored in the pressure storage chamber 2'. This first system pressure is used for pre-injection and, if necessary, for post-injection (HC enrichment for exhaust gas aftertreatment or soot reduction) as well as for displaying an injection course with plateau (boat injection). For the injection of fuel with a second higher system pressure, each injector 3 is assigned a local pressure booster 4 with a check valve 5 and with a displaceable piston 6. Such fuel injection devices are known for example from DE-A1 - 19910970.
Zur Steuerung des Druckverstärkers 4 wird der Druck im durch einen Übergang von einem größeren zu einem kleineren Kolbenquerschnitt ausgebildeten Differenzraum 7 verwendet. Zur Wiederbefüllung und Deaktivierung des Druckverstärkers wird der Differenzraum 7 mit einem Versorgungsdruck (Raildruck) beaufschlagt. Dann herrschen an allen Druckflächen eines Kolbens 6 die gleichen Druckverhältπisse (Raildruck). Der Kolben 6 ist druckausgegiichen. Durch eine zusätzliche Feder 8 wird der Kolben 6 in seine Ausgangsstellung gedrückt. Zur Aktivierung des Druckverst rkers 4 wird der Differenzraum 7 druckentlastet und der Druckverstärker 4 erzeugt eine Druckverstärkung gemäß dem Flächenverhältnis. Durch diese Art der Steuerung kann erreicht werden, dass zur Rückstellung des Druckverstärkers 4 und zum Wiederbefüllen einer Druckkammer 9 ein niederdruckseitiger Druckverst rkerraum 10 nicht druckentlastet werden muss. Bei einer kleinen hydraulischen Übersetzung können damit die Entspannungsverluste stark reduziert werden.The pressure in the differential space 7 formed by a transition from a larger to a smaller piston cross-section is used to control the pressure booster 4. In order to refill and deactivate the pressure booster, the differential space 7 is supplied with a supply pressure (rail pressure). Then the same pressure conditions (rail pressure) prevail on all pressure surfaces of a piston 6. The piston 6 is pressure balanced. With an additional spring 8 the piston 6 is pressed into its starting position. To activate the pressure amplifier 4, the differential space 7 is relieved of pressure and the pressure amplifier 4 generates a pressure gain in accordance with the area ratio. With this type of control, it can be achieved that in order to reset the pressure booster 4 and to refill a pressure chamber 9, a low-pressure side pressure booster chamber 10 does not have to be relieved of pressure. With a small hydraulic ratio, the relaxation losses can be greatly reduced.
Zur Steuerung des Druckverst rkers 4 kann anstelle eines aufwendigen 3/2-Wege- Ventils eine Drossel 1 1 und ein. einfaches 2/2-Wege-Ventil 1 2 verwendet werden. Die Drossel 1 1 verbindet den '' Differenzraum 7 mit unter Versorgungsdruck stehendem Kraftstoff aus dem Druckspeicherraum 2 ' '. Das 2/2-Wege-Ventil 12 schließt den Differenzraum 7 an eine Leckageleituπg 13 an. Die Drossel 1 1 sollte möglichst klein ausgelegt werden, aber dennoch so groß, dass" der Kolben 6 zwischen den Einspritzzyklen in seine Ausgangslage zurückkehrt. Als Drossel kann auch eine Führungsleckage des Kolbens 6 verwendet werden. Bei geschlossenem 2/2-Wege-Ventil 1 2 entsteht keine Leckage in den Führungen des Kolbens 6, da der Differenzraum 7 druckbeaufschlagt ist. Die Drossel kann auch im Kolben integriert sein.To control the Druckverst rkers 4 instead of a complex 3/2-way valve, a throttle 1 1 and. simple 2/2-way valve 1 2 can be used. The throttle 1 1 connects the '' differential space 7 with fuel under supply pressure from the pressure storage space 2 ''. The 2/2-way valve 12 connects the differential chamber 7 to a leakage line 13. The throttle 1 1 should be designed as small as possible, but still so large that " the piston 6 returns to its starting position between the injection cycles. A guide leakage of the piston 6 can also be used as a throttle. With the 2/2-way valve 1 closed 2 there is no leakage in the guides of the piston 6, since the differential space 7 is pressurized, the throttle can also be integrated in the piston.
Sind die 2/2-Wege-Ventile 1 2 und 14 geschlossen, so steht der Injektor 3 unter dem Druck des Druckspeicherraums 2.' ' Der Druckverstärker 4 befindet sich in der Ausgangsstellung. Nun kann durch das Ventil 14 eine Einspritzung mit Ra ildruck erfolgen.. Wird eine Einspritzung mit höherem Druck gewünscht, so wird das 2/2- Wege-Ventil 12 angesteuert (geöffnet) und damit eine Druckverstärkung erreicht.If the 2/2-way valves 1 2 and 14 are closed, the injector 3 is under the pressure of the pressure storage space 2. ' ' The pressure booster 4 is in the starting position. Now an injection with rail pressure can take place through the valve 14. If an injection with a higher pressure is desired, the 2/2-way valve 12 is activated (opened) and thus a pressure increase is achieved.
Die Einspritzung erfolgt über eine Kraftstoff-Zumessung. mit Hilfe einer in einer Führungsbohrung axial verschiebbaren Düsennadel 15 mit einer konischen Ventildichtfläche an seinem einen Ende, mit der sie mit einer Ventiisitzf l che am Injektorgehäuse des Injektors 3 zusammenwirkt. An der Ventiisitzf lache des Injektorgehäuses sind Einspritzöffnungen vorgesehen. Innerhalb eines Düsenraums 16 ist eine in Öffnungsrichtung der Düsennadel 1 5 weisende Druckfläche dem dort herrschenden Druck ausgesetzt, der über eine Druckleitung dem Düsenraum 16 zugeführt wird. Koaxial zu einer Ventilfeder 17 greift ferner an der Düsennadel 1 5 ein Druckstück 18 an, das mit seiner der Ventildichtfläche abgewandten Stirnseite den Steuerraum 19 begrenzt. Der Steuerraum 1 9 hat vom Kraftstoffdruckanschluß her einen Zulauf mit einer ersten Drossel und einen Ablauf zu der Leckageleitung 13, die durch das 2/2-Wege-Ventil 14 gesteuert wird.The injection takes place via a fuel metering. with the aid of a nozzle needle 15 which is axially displaceable in a guide bore and has a conical valve sealing surface at one end, with which it cooperates with a valve seat surface on the injector housing of the injector 3. Injection openings are provided on the valve seat surface of the injector housing. Within a nozzle space 16, a pressure surface pointing in the opening direction of the nozzle needle 15 is there exposed to prevailing pressure, which is supplied to the nozzle chamber 16 via a pressure line. Coaxial with a valve spring 17, a pressure piece 18 also acts on the nozzle needle 15, which delimits the control chamber 19 with its end face facing away from the valve sealing surface. The control chamber 1 9 has an inlet with a first throttle and an outlet to the leakage line 13, which is controlled by the 2/2-way valve 14, from the fuel pressure connection.
Unter dem ersten oder zweiten Systemdruck stehender Kraftstoff füllt ständig den Düsenraum 16 und den Steuerraum 19, Bei Betätigung (Öffnen)- des 2/2-Wege- Ventils 14 kann der Druck im Steuerraum 1 9 abgebaut werden, so dass in der Folge die in Öffnungsrichtung auf die Düsennadel 1 5 wirkende Druckkraft im Düsenraum 16 den in Schließrrchtung auf die Düsennadel 15 wirkende Druckkraft übersteigt. Die Ventildichtfläche hebt von der Ventilsitzfläche ab und Kraftstoff wird eingespritzt. Dabei lässt sich der Druckentlastungsvorgang des Steuerraums 1 9 und 'somit die Hubsteuerung der Düsennadel 1 5 über die Dimeήsionierung der Drosseln beeinflussen.Fuel under the first or second system pressure constantly fills the nozzle chamber 16 and the control chamber 19. When the 2/2-way valve 14 is actuated (opened), the pressure in the control chamber 1 9 can be reduced, so that the in Opening direction on the nozzle needle 1 5 pressure force in the nozzle chamber 16 exceeds the pressure force acting in the closing direction on the nozzle needle 15. The valve sealing surface lifts off the valve seat surface and fuel is injected. Here, the pressure relief operation can be influenced via the Dimeήsionierung the throttles of the control chamber 9 and 1 'thus the stroke control of the nozzle needle 1. 5
Das Ende der Einspritzung wird durch erneutes Betätigen (Schließen) des 2/2- Wege-Ventüs 1 eingeleitet, das den Steuerraum 19 wieder von der Leckageleitung 1 3 abkoppelt, so dass sich im Steuerraum 1 9 wieder ein Druck aufbaut, der das Druckstück 1 8 in Schließrichtung bewegen kann.The end of the injection is initiated by actuating (closing) the 2/2-way valve 1 again, which decouples the control chamber 19 from the leakage line 1 3, so that a pressure builds up again in the control chamber 1 9, which pressure element 1 8 can move in the closing direction.
Gemäß Fign. 1 und 2 ist der Zulauf zum niederduckseitigen Druckverstarkerraum 10 und/oder der Ablauf aus dem Differenzraum 7 (siehe Fig. 1) mit einer kontinuierlichen Querschnittsvergrößerung versehen. Es kann ein flacher Druckanstieg ohne störende Druckschwingungen erreicht werden. Gemäß Fig. 1 wird durch die Bewegungsrichtung 23 eines Kolbens 24 (Längsrichtung der Öffnung und des Kolbens) je nach Stellung des Kolbens 24 lediglich eine Teilfläche 25 einer schlitzförmigen Öffnung 26 bis zu einer Steuerkante 24' freigegeben und eine Teilfläche 27 der Öffnung 26 abgedeckt. Die Öffnung 26 in der Wandfläche eines Druckverstärkerraums (Differenzraum oder Niederdruckraum) stellt die Verbindung des Differenzraums 7 (siehe Fig. 1 ) zur Leckageleitung oder die Verbindung des niederdruckseitigen Druckverstärkerraums 10 zur Druckleitung 2 her (siehe Fig. 1) und ist durch den Kolben verschließbar. Mit zunehmendem Kolbenhub wird ein . größerer Zulauf- oder Ablaufquerschnitt freigegeben. Gemäß Fig. 2 weist eine schlitzförmige Öffnung 28 in er Wandfläche eines Druckverstärkerraums eine in Bewegungsrichtung 29 des Kolbens 30 variable Querschnittsfläche auf. Der Kolben 30 besitzt selbst eine Ausnehmung 31 , weiche die durchgängige Verbindung des Differenzraums 7 (siehe Fig. 1) zur Leckageleitung oder die Verbindung zwischen des Niederdruckraums 10 und der Druckleitung 2 herstellt. Die Ausnehmung 31 bildet eine Art Steuerfenster, das an dem Schlitz 28 entlang gleitet.According to FIGS. 1 and 2, the inlet to the pressure intensifier space 10 on the low-pressure side and / or the outlet from the differential space 7 (see FIG. 1) is provided with a continuous cross-sectional enlargement. A flat rise in pressure can be achieved without disturbing pressure fluctuations. 1, depending on the position of the piston 24, only a partial surface 25 of a slot-shaped opening 26 up to a control edge 24 'is released by the direction of movement 23 of a piston 24 (longitudinal direction of the opening and the piston) and a partial surface 27 of the opening 26 is covered. The opening 26 in the wall surface of a pressure booster chamber (differential chamber or low-pressure chamber) connects the differential chamber 7 (see FIG. 1) to the leakage line or connects the low-pressure-side pressure booster chamber 10 to the pressure line 2 (see FIG. 1) and can be closed by the piston , With increasing piston stroke becomes a. larger inlet or outlet cross-section released. 2, a slot-shaped opening 28 in the wall surface of a pressure booster chamber has a cross-sectional area that is variable in the direction of movement 29 of the piston 30. The piston 30 itself has a recess 31, which establishes the continuous connection of the differential space 7 (see FIG. 1) to the leakage line or the connection between the low-pressure space 10 and the pressure line 2. The recess 31 forms a kind of control window that slides along the slot 28.
Alternativ kann die schlitzförmige Öffnung 28 auch im Kolben und die Steuerkante 24 ' ..bzw eine Ausnehmung '31 in der Wandfläche ausgebildet -sein. Alternatively, the slot-shaped opening 28 can also be formed in the piston and the control edge 24 '... Or a recess '31 in the wall surface.

Claims

P A T E N T A N S P R Ü C H E PATENT CLAIMS
1. Kraftstoffeinspritzeinrichtung ( 1 ) mit einem Druckverstärker (4) , der einen über einen niederdruckseitigen Druckverst rkerraum (10) druckbeaufschlagbaren, verschiebbaren Kolben (6; 24; 30) zur Komprimierung des einem Injektor (3) zuzuführenden Kraftstoffs in einem hochdruckseitigen Druckverst rkerraum (9) aufweist, wobei der Hub des Kolbens (6; 24; 30) im wesentlichen durch den Druck in einem Differenzraum (7) des Druckverstärkers (4) steuerbar ist und zur Beeinflussung des dem Injektor (3) zugeführten Kraftstoffdrucks verwendet . wird, dadurch gekennzeichnet, Mittel (24, 25; 28, 31 ) zur stufenlosen1. Fuel injection device (1) with a pressure booster (4) which has a displaceable piston (6; 24; 30) which can be pressurized via a low-pressure side pressure booster chamber (10) for compressing the fuel to be supplied to an injector (3) in a high-pressure side pressure booster chamber ( 9), the stroke of the piston (6; 24; 30) being essentially controllable by the pressure in a differential space (7) of the pressure booster (4) and used to influence the fuel pressure supplied to the injector (3). is characterized, means (24, 25; 28, 31) for stepless
Vergrößerung des Zulaufquerschnitts zum niederdruckseitigenEnlargement of the inlet cross-section to the low pressure side
.Druckverstarkerraum (1 0) des Druckverstärkers (4) oder des Ablaufquerschnitts aus dem Differenzraum (7) des Druckverstarkers (4) vorgesehen sind..Pressure booster space (1 0) of the pressure booster (4) or the drain cross section from the differential space (7) of the pressure booster (4) are provided.
2. -Kraftstoffeinspritzeinrichtung nach Anspruch 1 , dadurch gekennzeichnet, dass die Mittel durch einen schlitzförmige Öffnung (26; 28) zwischen einem Raum (7, 1 0) des Druckverstärkers (4) und einer Zuleitung und den die Öffnung (26;28) verschließenden oder freigebenden Kolben (24; 30) ausgebildet sind.2. Fuel injection device according to claim 1, characterized in that the means through a slot-shaped opening (26; 28) between a space (7, 1 0) of the pressure booster (4) and a feed line and the opening (26; 28) closing or releasing pistons (24; 30) are formed.
' 3. Kraftstoffeinspritzeinrichtung nach Anspruch 2, dadurch gekennzeichnet, dass der Kolben (24) eine Steuerkante (24 ') aufweist, bis zu welcher die Öffnung (26) freigeben wird. ' 3. Fuel injection device according to claim 2, characterized in that the piston (24) has a control edge (24 ' ), up to which the opening (26) is released.
4. Kraftstoffeinspritzeinrichtung nach Anspruch 2, dadurch gekennzeichnet, dass der Kolben (30) eine Ausnehmung (31 ) aufweist, welche über der Öffnung (28) anordenbar ist und einen freigegebenen Bereich der Öffnung (28) definiert. 4. Fuel injection device according to claim 2, characterized in that the piston (30) has a recess (31) which can be arranged above the opening (28) and defines a released area of the opening (28).
EP02745063A 2001-06-01 2002-05-18 Fuel injection device comprising a pressure amplifier Expired - Lifetime EP1397591B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10126685A DE10126685A1 (en) 2001-06-01 2001-06-01 Fuel injection system, at an IC motor, has a pressure amplifier to give a flat pressure increase without pressure oscillations
DE10126685 2001-06-01
PCT/DE2002/001801 WO2002099268A1 (en) 2001-06-01 2002-05-18 Fuel injection device comprising a pressure amplifier

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EP1397591A1 true EP1397591A1 (en) 2004-03-17
EP1397591B1 EP1397591B1 (en) 2007-04-25

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US (1) US6895935B2 (en)
EP (1) EP1397591B1 (en)
JP (1) JP2004521241A (en)
DE (2) DE10126685A1 (en)
WO (1) WO2002099268A1 (en)

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EP3108807A1 (en) * 2015-06-26 2016-12-28 Stryker European Holdings I, LLC Bone healing probe

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US6895935B2 (en) 2005-05-24
DE50210031D1 (en) 2007-06-06
JP2004521241A (en) 2004-07-15
US20040020464A1 (en) 2004-02-05
WO2002099268A1 (en) 2002-12-12
DE10126685A1 (en) 2002-12-19
EP1397591B1 (en) 2007-04-25

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