EP1415082A1 - Fuel injector having two-way valve control - Google Patents

Fuel injector having two-way valve control

Info

Publication number
EP1415082A1
EP1415082A1 EP02750826A EP02750826A EP1415082A1 EP 1415082 A1 EP1415082 A1 EP 1415082A1 EP 02750826 A EP02750826 A EP 02750826A EP 02750826 A EP02750826 A EP 02750826A EP 1415082 A1 EP1415082 A1 EP 1415082A1
Authority
EP
European Patent Office
Prior art keywords
pressure
switching valve
fuel injector
valve
nozzle
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.)
Withdrawn
Application number
EP02750826A
Other languages
German (de)
French (fr)
Inventor
Friedrich Boecking
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 EP1415082A1 publication Critical patent/EP1415082A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0003—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure
    • F02M63/0007—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure using electrically actuated valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • 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
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
    • F02M63/0043—Two-way valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0059—Arrangements of valve actuators
    • F02M63/0061—Single actuator acting on two or more valve bodies
    • 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 combustion chambers of an internal combustion engine are assigned fuel injectors which are supplied with fuel under high pressure.
  • 3/2-way valves can be used on fuel injectors, which are installed together with a 2/2-way valve. Interconnection of a 3/2-way valve with a 2/2-way valve is common practice, but involves a great deal of effort in terms of coordinating the valves with one another.
  • DE 197 01 879 AI relates to a fuel injection device for internal combustion engines.
  • This comprises a common high-pressure accumulator (common rail) that can be filled with fuel from a high-pressure pump.
  • This is connected via injection lines to injection valves projecting into the combustion chamber of the internal combustion engine to be supplied.
  • Their opening and closing movements are each controlled by an electrically controlled control valve, which is designed as a 3/2-way valve.
  • This connects a high-pressure channel opening at an injection opening of the injection valve to the injection line or a relief line.
  • a hydraulic work space which can be filled with high fuel pressure is provided on the control valve member of the control valve and can be opened in a relief channel for adjusting the setting position of the control valve member of the control valve.
  • the working space of the control valve member is designed as a hydraulic working space that can be filled with high fuel pressure, which acts on the control valve member against an hydraulic opening force acting on it in the closing direction of a flow cross-section between the injection line and the high-pressure channel and which can be opened in a relief chamber.
  • the tax valve member traversed by an oblique throttle bore and constantly acted upon by this under high pressure fuel.
  • the inlet throttle integrated in the control valve member and designed in a smaller throttle cross section is difficult to manufacture in terms of its manufacture and fine machining.
  • DE 197 44 518 AI shows a mass-reduced fuel injection valve for internal combustion engines.
  • This comprises an axially displaceable valve body which is arranged in a valve body and has a conical valve sealing surface at its end facing the combustion chamber of the internal combustion engine, with which it interacts with a conical valve seat surface on the valve body for controlling an injection cross section.
  • the valve member is slidably guided on an internal guide on a pin of a stationary insert body.
  • the opening and stroke movement of the valve body is advantageously limited by mechanical stroke stop surfaces on the pin of a stationary insert body.
  • the control valve opening the control chamber into a relief chamber can be designed as a 2/2-way solenoid valve, but alternatively, 2/3, 3 / 2- or 3/3 control valves can also be used.
  • a stroke / pressure-controlled fuel injector can be implemented which is of simple construction.
  • a forward stroke which is provided between the 2/2-way valves, enables one of the 2/2-way valves, i.e. switch the valve located on the pressure accumulator side without actuating the second 2/2-way valve which releases a leak oil drain.
  • the second 2/2-way valve is only switched to its open position when a pre-stroke has been overcome in the direction of switching of the valve actuator; until then the control chamber of the fuel injector configured according to the invention remains from the low pressure side, i.e. completed the leakage oil drain, the nozzle needle remains in its closed position due to the high pressure level prevailing in the control room.
  • the second 2/2-way valve opens to the leakage oil and the fuel injector is stroke-controlled. If, on the other hand, the two 2/2-way valves are switched directly into their open position by the actuator, the fuel injector works under pressure control. It must be ensured that the design of the throttle elements, which are particularly simple to manufacture, for pressure relief and pressurization of the control chamber of the fuel injector ensures its pressure relief is.
  • the outlet throttle is designed with a larger cross-sectional area and enables a greater fuel flow than the inlet throttle, which is accommodated in an inlet connected to a high-pressure source and controllable by means of the first 2/2-way valve.
  • the sealing spring acting on the nozzle needle in the injector housing releases the opening of the injection nozzle after a pressure p D 0E corresponding to the nozzle opening pressure has been reached .
  • the pressure built up in the nozzle chamber counteracts the closing force of the sealing spring when the opening pressure level is reached.
  • the single figure shows a diagram of an injector body, the control and nozzle space of which can be actuated by two 2/2-way valves which can be actuated by an actuator.
  • FIG. 1 shows the basic sketch of a fuel injector with a nozzle chamber and a control chamber, with two 2/2-way valves that can be actuated by means of an actuator, for example a piezo actuator.
  • a control chamber 2 is provided in an injector body 1 of a fuel injector for injecting fuel into the combustion chamber of a combustion engine.
  • a nozzle needle 3, shown only schematically in the injector body 1, is actuated by this.
  • the control chamber 2 inside the injector body 1 is delimited by a control chamber wall 5 in addition to the end face 4.
  • a relief line 6 with the discharge throttle element 7 contained therein extends from the control chamber 2 to a switching valve 27.
  • the control chamber 2 in the interior of the injector body 1 is supplied with fuel under high pressure via an inlet 8 on the high-pressure side with an inlet throttle element 9 integrated therein.
  • a first switching valve 21 is interposed in the inlet 8 on the high-pressure side, which extends from the control chamber 2 to a high-pressure source 20, shown schematically here. from Inlet 8 on the high-pressure side branches off from a nozzle space inlet 17, via which a nozzle space 15 surrounding the nozzle needle 3 can also be acted upon by fuel under high pressure.
  • the nozzle needle 3 is supported by a spring element 11 in the injector body 1 of the fuel injector.
  • the spring element 11 is supported on the one hand on a stop ring 10 on the injector body 1, while the end of the spring element 11 opposite the stop ring 10 is supported on a shoulder 12 of the nozzle needle 3.
  • the nozzle needle 3 is provided with a pressure shoulder 14 in the area in which it is annularly surrounded by the nozzle space 15.
  • the nozzle needle 3 can be provided with a conically tapering end 16, via which the injection openings (not shown here), which protrude into the combustion chamber of the internal combustion engine, are released or closed depending on the stroke movement of the nozzle needle 3 in the injector body 1.
  • Throttle elements which serve as additional leakage, can each be assigned to the nozzle chamber inlet 17 and the relief line 6 extending to the low-pressure side 19 of the fuel injector.
  • Position 18.1 can be used to assign a throttle element to the nozzle space inlet 17 to represent an additional leak; in an alternative embodiment, this can also be assigned to the relief line 6 in the low-pressure region 19 of the fuel injector in position 18.2.
  • the high-pressure inlet 8 to the control chamber 2 extends from the high-pressure source 20 schematically indicated here, the inlet 8 branching off in front of an inlet throttle element 9 provided therein into a nozzle chamber inlet 17, via which the nozzle needle 3 surrounding the pressure shoulder 14 is surrounded Control chamber 15 is subjected to fuel under high pressure.
  • a first switching valve 21 is provided, which is preferably designed as a 2/2-way valve. The first switching valve 21 can be switched to a closed position 22 and an opening position 23.
  • Reference number 24 identifies the side of the first switching valve 21 which is assigned to the high-pressure source 20 and is preferably designed as a 2/2-way valve.
  • the first switching valve can be actuated via an actuator 26, which can be designed on the one hand as a piezo actuator 26 or on the other hand as a solenoid valve ,
  • the one Control chamber 2 facing side of the other switching valve 27 is identified by reference numeral 31, while that facing the low pressure area of the fuel injector
  • the relief line 6 runs from the latter in the direction of the low-pressure region 19 of the fuel injector in accordance with the schematic representation in FIG. 1.
  • a preliminary stroke 33 is set between the first switching valve 21, which is preferably designed as a 2/2-way valve, and the further switching valve 27.
  • the preliminary stroke 33 denotes the distance between two contact surfaces 34, which are formed on the adjustable valve bodies of the first switching valve 21, which is preferably designed as a 2/2-way valve, and on the further, second switching valve 27.
  • the actuator 26 assigned to the first switching valve which can be either a piezo actuator or a solenoid valve, the first switching valve 21 and the further switching valve 27 are actuated in the switching direction 32, bridging the preliminary stroke 33 set between the contact surfaces 34.
  • the first switching valve 21, which is preferably in the form of a 2/2-way valve, is constantly subjected to high fuel pressure on its side 24 facing the high pressure source 20. Leakage oil pressure level is constantly present at the further switching valve 27, which can preferably be configured as a 2/2-way valve analogously to the first switching valve 21. If the actuator 26 assigned to the first switching valve 21 and the further switching valve 27 is energized, for example in the form of a piezo actuator, the first switching valve 21 opens from its closed position 22 shown in FIG. 1 into the open position identified by reference numeral 23.
  • the pressure present in the high-pressure source 20 thus acts on the inlet 8 on the high-pressure side and thus probably on the control chamber 2 and, via the nozzle chamber inlet 17, on the nozzle chamber 15, which encloses the nozzle needle 3.
  • the actuator 26, viewed in the switching direction 32 is actuated such that the forward stroke 33 set between the contact surfaces 34 is not exceeded, the further switching valve 27 remains in the closed position 28, i.e. there is no pressure relief of the control chamber 2 via the relief line 6 on the low pressure side 19 of the injector.
  • the second switching valve 27 is opened from its closed position 28 into its open position 29 in this state, there is a connection between the relief line 6 and the low-pressure side 19 of the fuel injector, ie the injector is now stroke-controlled. It is important that the discharge throttle 7 accommodated in the relief line 6 and the inlet throttle 9 accommodated in the inlet 8 on the high-pressure side are coordinated in such a way that pressure relief of the control chamber / nozzle needle system of the injector is ensured via these throttle elements 7, 8.
  • the spring force between the stop ring 10 and shoulder 12 on the nozzle needle 3 is dimensioned in such a way that it is adjusted to the required nozzle opening pressure.
  • the sealing spring 11 which acts as a nozzle holder spring, functions as a nozzle holder spring when the first switching valve 21 is switched on and the further switching valve 27 is switched on and, in the pressure-controlled operating mode of the fuel injector as shown in FIG. 1, indicates the injection openings in the cone region 16 of the nozzle needle 3 after the nozzle opening pressure has been exceeded the pressure shoulder 14 free.
  • the advantages that can be achieved with the outlined design variant include: to see that a very simple fuel injector can be realized.
  • the fuel injector according to the invention can be used both as a stroke-controlled and also operate as a pressure controlled injector. Otherwise, these operating modes can only be realized by a 3/2-way valve in combination with a 2/2-way valve, with increased effort being required.
  • the design ratio of the outlet throttle 7 accommodated in the relief line 6 and of the throttle element 9 accommodated in the inlet 8 on the high-pressure side can be varied accordingly, so that it is guaranteed at all times that the pressure is relieved High-pressure side of the fuel injector can be guaranteed.

Abstract

The invention relates to a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine, comprising a nozzle needle (3). Said nozzle needle can move inside the injector body (1) between a position that opens injection openings and one that closes the injection openings by means of pressure build-up/pressure reduction inside the control space (2). The control space (2), on the overflow oil-side, can be pressurized via a pressure relief line (6) containing a discharge throttling element (7) and via a high pressure-side inlet (8) provided with an inlet throttle (9), which simultaneously subjects a nozzle space (15) inside the injector body (1) to the action of fuel. The change in pressure inside the control space (2) of the injector body (1) ensues via a first on-off valve (21) and via another on-off valve (27), whereby the first on-off valve (21) has a pre-travel (33) in the direction of switching through (32).

Description

Kraftstoffinjektor mit 2- Wege- VentilsteuerungFuel injector with 2-way valve control
Technisches GebietTechnical field
Bei Hochdruckeinspritzsystemen für direkteinspritzende Verbrennungskraftmaschinen werden den Brennräumen einer Verbrennungskraftmaschine Kraftstoffinjektoren zugeord- net, die mit unter hohem Druck stehenden Kraftstoff versorgt werden. An Kraftstoffinjektoren können 3/2- Wege- Ventile eingesetzt werden, die zusammen mit einem 2/2-Wege- Ventil eingebaut werden. Eine Zusammenschaltung eines 3/2-Wege-Ventils mit einem 2/2- Wege-Ventil ist gängige Praxis, jedoch mit hohem Aufwand hinsichtlich der Abstimmung der Ventile aufeinander verbunden.In high-pressure injection systems for direct-injection internal combustion engines, the combustion chambers of an internal combustion engine are assigned fuel injectors which are supplied with fuel under high pressure. 3/2-way valves can be used on fuel injectors, which are installed together with a 2/2-way valve. Interconnection of a 3/2-way valve with a 2/2-way valve is common practice, but involves a great deal of effort in terms of coordinating the valves with one another.
Stand der TechnikState of the art
DE 197 01 879 AI bezieht sich auf eine Kraftstoffeinspritzeinrichtung für Brennkraftma- schinen. Diese umfasst einen von einer Hochdruckpumpe mit Kraftstoff befüllbaren gemeinsamen Hochdrucksammeiraum (Common Rail). Dieser ist über Einspritzleitungen mit in den Brennraum der zu versorgenden Brennkraftmaschine ragenden Einspritzventilen verbunden. Deren Öffhungs- und Schließbewegungen werden jeweils von einem elektrisch angesteuerten Steuerventil gesteuert, welches als 3/2-Wege-Ventil ausgebildet ist. Dieses verbindet einen an einer Einspritzöffnung des Einspritzventils mündenden Hochdruckkanal mit der Einspritzleitung oder einer Entlastungsleitung. Dabei ist am Steuerventilglied des Steuerventils ein mit Kraftstoffhochdruck befullbarer hydraulischer Arbeitsraum vorgesehen, der zur Verstellung der Einstellposition des Steuerventilgliedes des Steuerventils in einen Entlastungskanal aufsteuerbar ist. Der Arbeitsraum des Steuerventilgliedes ist als ein mit Kraftstoffhochdruck befullbarer hydraulischer Arbeitsraum ausgebildet, der das Steuerventilglied entgegen einer an diesem angreifenden hydraulischen Öffnungskraft in Schließrichtung eines Durchströmquerschnittes zwischen Einspritzleitung und Hochdruckkanal beaufschlagt und der in einen Entlastungsraum aufsteuerbar ist. Dazu ist das Steuer- ventilglied von einer schräg verlaufenden Drosselbohrung durchzogen und über diesen ständig mit unter hohem Druck stehenden Kraftstoff beaufschlagt. Die in das Steuerventilglied integrierte, in einem kleineren Drosselquerschnitt ausgebildete Zulaufdrossel ist hinsichtlich ihrer Herstellung und Feinbearbeitung aufwändig zu fertigen.DE 197 01 879 AI relates to a fuel injection device for internal combustion engines. This comprises a common high-pressure accumulator (common rail) that can be filled with fuel from a high-pressure pump. This is connected via injection lines to injection valves projecting into the combustion chamber of the internal combustion engine to be supplied. Their opening and closing movements are each controlled by an electrically controlled control valve, which is designed as a 3/2-way valve. This connects a high-pressure channel opening at an injection opening of the injection valve to the injection line or a relief line. In this case, a hydraulic work space which can be filled with high fuel pressure is provided on the control valve member of the control valve and can be opened in a relief channel for adjusting the setting position of the control valve member of the control valve. The working space of the control valve member is designed as a hydraulic working space that can be filled with high fuel pressure, which acts on the control valve member against an hydraulic opening force acting on it in the closing direction of a flow cross-section between the injection line and the high-pressure channel and which can be opened in a relief chamber. The tax valve member traversed by an oblique throttle bore and constantly acted upon by this under high pressure fuel. The inlet throttle integrated in the control valve member and designed in a smaller throttle cross section is difficult to manufacture in terms of its manufacture and fine machining.
DE 197 44 518 AI zeigt ein massereduziertes Kraftstoffeinspritzventil für Brennkraftma- schinen. Dieses umfasst einen in einem Ventilkörper angeordneten, axial verschiebbaren Ventilkörper, welcher an seinem dem Brennraum der Brennkraftmaschine zugewandten Ende eine konische Ventildichtfläche aufweist, mit der es mit einer konischen Ventilsitz- fläche am Ventilkörper zur Steuerung eines Einspritzquerschnittes zusammenwirkt. Dabei ist das Ventilglied über eine Innenführung gleitverschiebbar auf einem Zapfen eines ortsfesten Einsatzkörpers geführt. Die Öffnungs- und Hubbewegung des Ventilkörpers wird dabei in vorteilhafter Weise durch mechanische Hubanschlagflächen am Zapfen eines ortsfesten Einsatzkörpers begrenzt. Das den Steuerraum in einen Entlastungsraum aufsteuernde Steuerventil kann dabei als 2/2- Wege-Magnetventil ausgebildet sein, alternativ können aber auch 2/3-, 3/2- oder 3/3-Steuerventile eingesetzt werden.DE 197 44 518 AI shows a mass-reduced fuel injection valve for internal combustion engines. This comprises an axially displaceable valve body which is arranged in a valve body and has a conical valve sealing surface at its end facing the combustion chamber of the internal combustion engine, with which it interacts with a conical valve seat surface on the valve body for controlling an injection cross section. The valve member is slidably guided on an internal guide on a pin of a stationary insert body. The opening and stroke movement of the valve body is advantageously limited by mechanical stroke stop surfaces on the pin of a stationary insert body. The control valve opening the control chamber into a relief chamber can be designed as a 2/2-way solenoid valve, but alternatively, 2/3, 3 / 2- or 3/3 control valves can also be used.
Darstellung der ErfindungPresentation of the invention
Mit der erfindungsgemäßen Lösung ist ein hub-/druckgesteuerter Kraftstoffmjektor realisierbar, der einfach aufgebaut ist. Durch einen Vorhub, der zwischen den 2/2-Wege- Ventilen vorgesehen ist, lässt sich eines der 2/2- Wege- Ventile, d.h. das auf der Druckspeicherseite angeordnete Ventil schalten, ohne dass das Zweite, einen Leckölablauf freigeben- de 2/2-Wege-Ventil betätigt wird. Erst wenn in Durchschalterichtung des Ventilstellers gesehen, ein Vorhub überwunden ist, wird das zweite 2/2-Wege- Ventil in seine Öffnungs- stellung geschaltet; bis dahin bleibt der Steuerraum des erfindungsgemäß konfigurierten Kraftstoffinjektors von der Niederdruckseite, d.h. dem Leckölablauf abgeschlossen, die Düsennadel verbleibt durch das im Steuerraum herrschende hohe Druckniveau in ihrer Schließstellung.With the solution according to the invention, a stroke / pressure-controlled fuel injector can be implemented which is of simple construction. A forward stroke, which is provided between the 2/2-way valves, enables one of the 2/2-way valves, i.e. switch the valve located on the pressure accumulator side without actuating the second 2/2-way valve which releases a leak oil drain. The second 2/2-way valve is only switched to its open position when a pre-stroke has been overcome in the direction of switching of the valve actuator; until then the control chamber of the fuel injector configured according to the invention remains from the low pressure side, i.e. completed the leakage oil drain, the nozzle needle remains in its closed position due to the high pressure level prevailing in the control room.
Wird der Vorhubweg zwischen dem ersten 2/2-Wege- Ventil und dem zweiten 2/2-Wege- Ventil hingegen überwunden, öffnet das zweite 2/2-Wege- Ventil zum Lecköl und der Kraftstoffinjektor ist hubgesteuert. Werden hingegen die beiden 2/2- Wege- Ventile direkt vom Steller in ihre Öffnungsstellung durchgeschaltet, arbeitet der Kraftstoffinjektor druckgesteuert. Es muss sichergestellt sein, dass durch die Auslegung der fertigungstechnisch besonders einfach herstellbaren Drosselelemente zur Druckentlastung und Druckbeaufschlagung des Steuerraums des Kraftstoffinjektors dessen Druckentlastung gewährleistet ist. Zu diesem Zweck ist die Ablaufdrossel mit größerer Querschnittsfläche ausgelegt und ermöglicht einen größeren Kraftstoffdurchfluss als die Zulaufdrossel, die in einem mittels des ersten 2/2-Wege- Ventils aufsteuerbaren, mit einer Hochdruckquelle verbundenen Zulauf aufgenommen ist.On the other hand, if the pre-stroke distance between the first 2/2-way valve and the second 2/2-way valve is overcome, the second 2/2-way valve opens to the leakage oil and the fuel injector is stroke-controlled. If, on the other hand, the two 2/2-way valves are switched directly into their open position by the actuator, the fuel injector works under pressure control. It must be ensured that the design of the throttle elements, which are particularly simple to manufacture, for pressure relief and pressurization of the control chamber of the fuel injector ensures its pressure relief is. For this purpose, the outlet throttle is designed with a larger cross-sectional area and enables a greater fuel flow than the inlet throttle, which is accommodated in an inlet connected to a high-pressure source and controllable by means of the first 2/2-way valve.
Die die Düsennadel im Injektorgehäuse beaufschlagende Dichtfeder, bevorzugt als Spiralfeder ausgebildet, gibt die Öffnung der Einspritzdüse nach Erreichen eines dem Düsenöffnungsdruck entsprechenden Druckes pD 0E frei. Mit der den Düsenraum durchsetzenden Druckschulter wirkt der im Düsenraum aufgebaute Druck ab Erreichen des Öffhungs- druckniveaus der Schließkraft der Dichtfeder entgegen.The sealing spring acting on the nozzle needle in the injector housing, preferably in the form of a spiral spring, releases the opening of the injection nozzle after a pressure p D 0E corresponding to the nozzle opening pressure has been reached . With the pressure shoulder passing through the nozzle chamber, the pressure built up in the nozzle chamber counteracts the closing force of the sealing spring when the opening pressure level is reached.
Zeichnungdrawing
Die Erfindung wird anhand der Zeichnung näher erläutert.The invention is explained in more detail with reference to the drawing.
Die einzige Figur zeigt ein Schema eines Injektorkörpers, dessen Steuer- und Düsenraum über zwei mittels eines Aktors betätigbare 2/2-Wege-Ventile betätigbar sind.The single figure shows a diagram of an injector body, the control and nozzle space of which can be actuated by two 2/2-way valves which can be actuated by an actuator.
Ausführungsvariantenvariants
Figur 1 ist die Prinzipskizze eines Kraftstoffinjektors mit einem Düsenraum und einem Steuerraum entnehmbar, mit zwei 2/2-Wege- Ventilen, die mittels eines Stellers, beispiels- weise eines Piezoaktors betätigbar sind.FIG. 1 shows the basic sketch of a fuel injector with a nozzle chamber and a control chamber, with two 2/2-way valves that can be actuated by means of an actuator, for example a piezo actuator.
In einem Injektorkörper 1 eines Kraftstoffinjektors zum Einspritzen von Kraftstoff in den Brennraum einer Verbrermungskraftmaschine ist ein Steuerraum 2 vorgesehen. Über diesen wird eine hier nur schematisch wiedergegebene Düsennadel 3 im Injektorkörper 1 be- tätigt. Der Steuerraum 2 im Inneren des Injek;orkörpers 1 ist neben der Stirnfläche 4 durch eine Steuerraumwandung 5 begrenzt.A control chamber 2 is provided in an injector body 1 of a fuel injector for injecting fuel into the combustion chamber of a combustion engine. A nozzle needle 3, shown only schematically in the injector body 1, is actuated by this. The control chamber 2 inside the injector body 1 is delimited by a control chamber wall 5 in addition to the end face 4.
Vom Steuerraum 2 erstreckt sich eine Entlastungsleitung 6 mit darin aufgenommenem Ablaufdrosselelement 7 zu einem Schaltventil 27. Der Steuerraum 2 im Inneren des Injek- torkörpers 1 wird über einen hochdruckseitigen Zulauf 8 mit darin integriertem Zulaufdrosselelement 9 mit unter hohem Druck stehenden Kraftstoff versorgt. In den hochdruckseitigen Zulauf 8, der sich vom Steuerraum 2 zu einer hier schematisch dargestellten Hochdruckquelle 20 erstreckt, ist ein erstes Schaltventil 21 zwischengeschaltet. Vom hochdruckseitigen Zulauf 8 zweigt ein Düsenraumzulauf 17 ab, über welchen ein die Düsennadel 3 umgebender Düsenraum 15 ebenfalls mit unter hohem Druck stehenden Kraftstoff beaufschlagbar ist.A relief line 6 with the discharge throttle element 7 contained therein extends from the control chamber 2 to a switching valve 27. The control chamber 2 in the interior of the injector body 1 is supplied with fuel under high pressure via an inlet 8 on the high-pressure side with an inlet throttle element 9 integrated therein. A first switching valve 21 is interposed in the inlet 8 on the high-pressure side, which extends from the control chamber 2 to a high-pressure source 20, shown schematically here. from Inlet 8 on the high-pressure side branches off from a nozzle space inlet 17, via which a nozzle space 15 surrounding the nozzle needle 3 can also be acted upon by fuel under high pressure.
Die Düsennadel 3 stützt sich über ein Federelement 11 im Injektorkörper 1 des Kraftstoffinjektors ab. Das Federelement 11 stützt sich dazu einerseits an einem Anschlagring 10 am Injektorkörper 1 ab, während sich das dem Anschlagring 10 gegenüberliegende Ende des Federelementes 11 an einem Absatz 12 der Düsennadel 3 abstützt. Die Düsennadel 3 ist in dem Bereich, in welchem sie vom Düsenraum 15 ringförmig umschlossen ist, mit einer Druckschulter 14 versehen. Am dem Brennraum zugewandten Ende der Düsennadel 3 kann die Düsennadel 3 mit einem kegelförmig auslaufenden Ende 16 versehen sein, über welches die hier nicht dargestellten, in den Brennraum der Verbrermungskraftmaschine hineinragenden Einspritzöffnungen je nach Hubbewegung der Düsennadel 3 im Injektorkörper 1 freigegeben bzw. verschlossen sind. Dem Düsenraumzulauf 17 sowie der sich zur Niederdruckseite 19 des Kraftstoffinjektors erstreckenden Entlastungsleitung 6 können jeweils Drosselelemente zugeordnet sein, die als Zusatzleckage dienen. Mit Position 18.1 kann dem Düsenraumzulauf 17 ein Drosselelement zur Darstellung einer Zusatzleckage zugeordnet sein; in alternativer Ausführungsform kann dieses in Position 18.2 auch der Entlastungsleitung 6 in den Niederdruckbereich 19 des Kraftstoffinjektors zugeordnet wer- den.The nozzle needle 3 is supported by a spring element 11 in the injector body 1 of the fuel injector. For this purpose, the spring element 11 is supported on the one hand on a stop ring 10 on the injector body 1, while the end of the spring element 11 opposite the stop ring 10 is supported on a shoulder 12 of the nozzle needle 3. The nozzle needle 3 is provided with a pressure shoulder 14 in the area in which it is annularly surrounded by the nozzle space 15. At the end of the nozzle needle 3 facing the combustion chamber, the nozzle needle 3 can be provided with a conically tapering end 16, via which the injection openings (not shown here), which protrude into the combustion chamber of the internal combustion engine, are released or closed depending on the stroke movement of the nozzle needle 3 in the injector body 1. Throttle elements, which serve as additional leakage, can each be assigned to the nozzle chamber inlet 17 and the relief line 6 extending to the low-pressure side 19 of the fuel injector. Position 18.1 can be used to assign a throttle element to the nozzle space inlet 17 to represent an additional leak; in an alternative embodiment, this can also be assigned to the relief line 6 in the low-pressure region 19 of the fuel injector in position 18.2.
Von der hier schematisch angedeuteten Hochdruckquelle 20 erstreckt sich der hochdruck- seitige Zulauf 8 zum Steuerraum 2, wobei der Zulauf 8 vor einem in diesem vorgesehenen Zulaufdrosselelement 9 in einen Düsenraumzulauf 17 abzweigt, über welchen der die Dü- sennadel 3 im Bereich der Druckschulter 14 umgebende Steuerraum 15 mit unter hohem Druck stehenden Kraftstoff beaufschlagt wird. Im hochdruckseitigen Zulauf ist ein erstes Schaltventil 21 vorgesehen, welches bevorzugt als 2/2-Wege- Ventil beschaffen ist. Das erste Schaltventil 21 lässt sich in eine Schließstellung 22 sowie in eine Öffnungsstelle 23 schalten. Die dem Steuerraum 2 zuweisende Seite des hochdruckseitigen Zulaufs 8 ist mit Bezugszeichen 25 gekennzeichnet; Bezugszeichen 24 identifiziert die der Hochdruckquelle 20 zuweisende Seite des ersten, bevorzugt als 2/2- Wege- Ventil ausgestalteten Schaltventils 21. Das erste Schaltventil lässt sich über einen Steller 26 betätigen, der einerseits als ein Piezoaktor 26 oder andererseits als ein Magnetventil beschaffen sein kann.The high-pressure inlet 8 to the control chamber 2 extends from the high-pressure source 20 schematically indicated here, the inlet 8 branching off in front of an inlet throttle element 9 provided therein into a nozzle chamber inlet 17, via which the nozzle needle 3 surrounding the pressure shoulder 14 is surrounded Control chamber 15 is subjected to fuel under high pressure. In the inlet on the high-pressure side, a first switching valve 21 is provided, which is preferably designed as a 2/2-way valve. The first switching valve 21 can be switched to a closed position 22 and an opening position 23. The side of the inlet 8 on the high-pressure side facing the control chamber 2 is identified by reference numeral 25; Reference number 24 identifies the side of the first switching valve 21 which is assigned to the high-pressure source 20 and is preferably designed as a 2/2-way valve. The first switching valve can be actuated via an actuator 26, which can be designed on the one hand as a piezo actuator 26 or on the other hand as a solenoid valve ,
Dem genannten ersten, bevorzugt als 2/2- Wege-Ventil ausgestalteten Schaltventil 21 liegt ein weiteres Schaltventil 27 gegenüber, welches ebenfalls bevorzugt als 2/2-Wege-Ventil beschaffen sein kann. Dieses nimmt eine mit Bezugszeichen 28 bezeichnete Schließstellung sowie eine mit Bezugszeichen 29 gekennzeichnete Öffhungsstellung ein. Die dem Steuerraum 2 zuweisende Seite des weiteren Schaltventils 27 ist mit Bezugszeichen 31 gekennzeichnet, während die dem Niederdruckbereich des Kraftstoffinjektors zuweisendeThe first switching valve 21, which is preferably designed as a 2/2-way valve, is opposite another switching valve 27, which can also preferably be configured as a 2/2-way valve. This assumes a closed position designated by reference number 28 and an open position identified by reference number 29. The one Control chamber 2 facing side of the other switching valve 27 is identified by reference numeral 31, while that facing the low pressure area of the fuel injector
Seite des weiteren Schaltventils 27 mit Bezugszeichen 30 gekennzeichnet ist. Von dieser verläuft die Entlastungsleitung 6 in Richtung des Niederdruckbereiches 19 des Kraftstof- finjektors gemäß der schematischen Wiedergabe in Figur 1.Side of the further switching valve 27 is identified by reference numeral 30. The relief line 6 runs from the latter in the direction of the low-pressure region 19 of the fuel injector in accordance with the schematic representation in FIG. 1.
Zwischen dem ersten, bevorzugt als 2/2- Wege-Ventil ausgebildeten Schaltventil 21 und dem weiteren Schaltventil 27 ist ein Vorhub 33 eingestellt. Der Vorhub 33 bezeichnet den Abstand zweier Kontaktflächen 34, die an den verstellbaren Ventilkörpern des ersten, be- vorzugt als 2/2- Wege- Ventil ausgestalteten Schaltventils 21 und am weiteren, zweiten Schaltventil 27 ausgebildet sind. Über den dem ersten Schaltventil zugeordneten Steller 26, der entweder ein Piezoaktor oder ein Magnetventil sein kann, werden das erste Schaltventil 21 sowie das weitere Schaltventil 27 in Durchschalterichtung 32, den zwischen den Kontaktflächen 34 eingestellten Vorhub 33 überbrückend, betätigt.A preliminary stroke 33 is set between the first switching valve 21, which is preferably designed as a 2/2-way valve, and the further switching valve 27. The preliminary stroke 33 denotes the distance between two contact surfaces 34, which are formed on the adjustable valve bodies of the first switching valve 21, which is preferably designed as a 2/2-way valve, and on the further, second switching valve 27. Via the actuator 26 assigned to the first switching valve, which can be either a piezo actuator or a solenoid valve, the first switching valve 21 and the further switching valve 27 are actuated in the switching direction 32, bridging the preliminary stroke 33 set between the contact surfaces 34.
Am ersten, bevorzugt als 2/2- Wege-Ventil ausgebildeten Schaltventil 21 liegt an dessen der Hochdruckquelle 20 zugewandter Seite 24 dauernd -Kraftstoffhochdruck an. Am weiteren Schaltventil 27, welches analog zum ersten Schaltventil 21 bevorzugt als 2/2- Wege- Ventil ausgestaltet sein kann, liegt dauernd Lecköldruckniveau an. Wird der dem ersten Schaltventil 21 und dem weiteren Schaltventil 27 zugeordnete Steller 26, beispielsweise ausgestaltet als ein Piezoaktor, bestromt, öffnet das erste Schaltventil 21 von seiner in Figur 1 dargestellten Schließstellung 22 in die mit Bezugszeichen 23 gekennzeichnete Öffnungsstellung. Der in der Hochdruckquelle 20 anstehende Druck wirkt somit auf den hochdruckseitigen Zulauf 8 und damit wohl auf den Steuerraum 2 sowie über den Düsen- raumzulauf 17 auf den Düsenraum 15, welcher die Düsennadel 3 umschließt. Solange der Steller 26 in Durchschalterichtung 32 gesehen so betätigt wird, dass der zwischen Kontaktflächen 34 eingestellte Vorhub 33 nicht überschritten wir, bleibt das weitere Schaltventil 27 in Schließstellung 28, d.h. es findet keine Druckentlastung des Steuerraums 2 über die Entlastungsleitung 6 auf die Niederdruckseite 19 des Injektors statt.The first switching valve 21, which is preferably in the form of a 2/2-way valve, is constantly subjected to high fuel pressure on its side 24 facing the high pressure source 20. Leakage oil pressure level is constantly present at the further switching valve 27, which can preferably be configured as a 2/2-way valve analogously to the first switching valve 21. If the actuator 26 assigned to the first switching valve 21 and the further switching valve 27 is energized, for example in the form of a piezo actuator, the first switching valve 21 opens from its closed position 22 shown in FIG. 1 into the open position identified by reference numeral 23. The pressure present in the high-pressure source 20 thus acts on the inlet 8 on the high-pressure side and thus probably on the control chamber 2 and, via the nozzle chamber inlet 17, on the nozzle chamber 15, which encloses the nozzle needle 3. As long as the actuator 26, viewed in the switching direction 32, is actuated such that the forward stroke 33 set between the contact surfaces 34 is not exceeded, the further switching valve 27 remains in the closed position 28, i.e. there is no pressure relief of the control chamber 2 via the relief line 6 on the low pressure side 19 of the injector.
Erfolgt hingegen in diesem Zustand eine Öffnung des zweiten Schaltventils 27 von seiner Schließstellung 28 in seine Öffnungsstellung 29, ist eine Verbindung zwischen der Entlastungsleitung 6 und der Niederdruckseite 19 des Kraftstoffinjektors gegeben, d.h. der Injektor wirkt nun hubgesteuert. Dabei ist wichtig, dass die in der Entlastungsleitung 6 auf- genommene Ablaufdrossel 7 sowie im hochdruckseitigen Zulauf 8 aufgenommene Zulaufdrossel 9 so abgestimmt sind, dass über diese Drosselelemente 7, 8 eine Druckentlastung des Steuerraum/Düsennadelsy stems des Injektors gewährleistet ist. Wird der dem ersten Schaltventil 21 zugeordnete Steller 26, zum Beispiel ein Piezoaktor oder ein Magnetventil hingegen in Durchschalterichtung 32 so betätigt, dass sowohl das ersten Schaltventil 21 in seine Öffnungsstellung 23 als auch das weitere Schaltventil 27 in seine Öffnungsstellung 29 überführt werden, ist der Steuerraum 2 im Injektorkörper 1 kurzgeschlossen und der Kraftstoffinjektor wirkt druckgesteuert. Das Federelement zwischen Anschlagring 10 und Absatz 12 an der Düsennadel 3 ist in seiner Schließkraft so bemessen, dass diese auf den erforderlichen Düsenöffnungsdruck eingestellt ist. Die in diesem Falle als Düsenhalterfeder fungierende Dichtfeder 11 fungiert bei durchgeschaltetem ersten Schaltventil 21 sowie durchgeschaltetem weiteren Schaltventil 27 als Düsen- halterfeder und gibt im druckgesteuerten Betriebsmodus des Kraftstoffinjektors gemäß der Darstellung in Figur 1 die Einspritzöffnungen im Kegelbereich 16 der Düsennadel 3 nach Überschreiten des Düsenöffnungsdruckes an der Druckschulter 14 frei.If, on the other hand, the second switching valve 27 is opened from its closed position 28 into its open position 29 in this state, there is a connection between the relief line 6 and the low-pressure side 19 of the fuel injector, ie the injector is now stroke-controlled. It is important that the discharge throttle 7 accommodated in the relief line 6 and the inlet throttle 9 accommodated in the inlet 8 on the high-pressure side are coordinated in such a way that pressure relief of the control chamber / nozzle needle system of the injector is ensured via these throttle elements 7, 8. If, on the other hand, the actuator 26 assigned to the first switching valve 21, for example a piezo actuator or a solenoid valve, is actuated in the switching direction 32 in such a way that both the first switching valve 21 is moved into its open position 23 and the further switching valve 27 is moved into its open position 29, the control chamber 2 short-circuited in the injector body 1 and the fuel injector is pressure-controlled. The spring force between the stop ring 10 and shoulder 12 on the nozzle needle 3 is dimensioned in such a way that it is adjusted to the required nozzle opening pressure. In this case, the sealing spring 11, which acts as a nozzle holder spring, functions as a nozzle holder spring when the first switching valve 21 is switched on and the further switching valve 27 is switched on and, in the pressure-controlled operating mode of the fuel injector as shown in FIG. 1, indicates the injection openings in the cone region 16 of the nozzle needle 3 after the nozzle opening pressure has been exceeded the pressure shoulder 14 free.
Die mit der skizzierten Ausführungsvariante erzielbaren Vorteile sind u.a. darin zu sehen, dass sich ein sehr einfach aufgebauter Kraftstoffinjektor realisieren läßt. Durch die Verwendung von zwei 2/2 -Wege- Ventilen als erstes Schaltventil 21 und weiteres Schaltventil 27, wobei zwischen diesen beiden Schaltventilen 21 bzw. 27 in Durchschalterichtung 32 gesehen in Vorhub 33 eingestellt ist, lässt sich der erfindungsgemäße Kraftstoffinjektor sowohl als ein hubgesteuerter als auch als ein druckgesteuerter Injektor betreiben. Die Realisierung dieser Betriebsmodi ist sonst lediglich durch ein 3/2-Schaltventil in Kombination mit einem 2/2- Wege- Ventil realisierbar, wobei ein erhöhter Aufwand zu betreiben ist.The advantages that can be achieved with the outlined design variant include: to see that a very simple fuel injector can be realized. By using two 2/2-way valves as the first switching valve 21 and further switching valve 27, wherein between these two switching valves 21 and 27, viewed in the switching direction 32, is set in the forward stroke 33, the fuel injector according to the invention can be used both as a stroke-controlled and also operate as a pressure controlled injector. Otherwise, these operating modes can only be realized by a 3/2-way valve in combination with a 2/2-way valve, with increased effort being required.
Durch das Vorsehen zusätzlicher Leckagedrosseln an den Positionen 18.1 bzw. 18.2 lässt sich das Auslegungsverhältnis der in der Entlastungsleitung 6 aufgenommenen Ablaufdrossel 7 bzw. des in der im hochdruckseitigen Zulauf 8 aufgenommenen Drosselelementes 9 entsprechend variieren, so dass alle Zeit gewährleistet ist, dass eine Druckentlastung der Hochdruckseite des Kraftstoffinjektors gewährleistet werden kann. By providing additional leakage throttles at positions 18.1 and 18.2, the design ratio of the outlet throttle 7 accommodated in the relief line 6 and of the throttle element 9 accommodated in the inlet 8 on the high-pressure side can be varied accordingly, so that it is guaranteed at all times that the pressure is relieved High-pressure side of the fuel injector can be guaranteed.
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BezugszeichenlisteLIST OF REFERENCE NUMBERS
1 Injektorkörper1 injector body
2 Steuerraum2 control room
3 Düsennadel3 nozzle needle
4 Stirnfläche4 end face
5 Steuerraumwandung5 control room wall
6 Entlastungsleitung6 discharge line
7 Drosselelement7 throttle element
8 hochdruckseitiger Zulauf8 inlet on the high pressure side
9 Zulaufdrosselelement9 Inlet throttle element
10 Anschlagring10 stop ring
11 Federelement11 spring element
12 Absatz12 paragraph
13 Führungsabschnitt13 guide section
14 Druckschulter14 pressure shoulder
15 Düsenraum15 nozzle area
16 Düsenkegel16 nozzle cones
17 Düsenraumzulauf17 nozzle space inlet
18. erste Position Zusatzleckage18. First position additional leakage
18.2 zweite Position Zusatzleckage18.2 Second position additional leakage
19 Leckölablauf (Niederdruckseite)19 drain oil drain (low pressure side)
20 Hochdruckquelle20 high pressure source
21 erstes 2/2- Wege- Ventil21 first 2/2-way valve
22 Schließstellung22 closed position
23 Öffhungsstellung 4 Speicherseite 5 Injektorseite23 Open position 4 storage side 5 injector side
26 Steller26 actuators
27 zweites 2/2- Wege- Ventil27 second 2/2-way valve
28 Schließstellung28 closed position
29 Öffhungsstellung29 opening position
30 Leckölseite30 leak oil side
31 Injektorseite31 injector side
32 Durchschalterichtung32 Direction of switching
33 Vorhub33 forward stroke
34 Kontaktfläche 34 contact surface

Claims

Patentansprüche claims
1. Kraftstoffinjektor zum Einspritzen von Kraftstoff in den Brennraum einer Verbrennungskraftmaschine mit einer Düsennadel (3), die im Injektorkörper (1) zwischen einer Einspritzöffnungen freigebenden und einer Einspritzöffnungen verschließenden Stellung durch Druckaufbau/Druckabbau in einem Steuerraum (2) betätigbar ist, der Steuerraum (2) leckölseitig über eine eine Ablaufdrossel (7) enthaltende Entlastungsleitung (6) und über einen hochdruckseitigen Zulauf (8) beaufschlagbar ist, der gleichzeitig einem Düsenraum (15) unter hohem Druck stehenden Kraftstoff zuführt, wobei ein erstes Schaltventil (21) im Hochdruckzulauf (8) vor dessen Verzweigung im Steuerraumzulauf vom Düsenzulauf (17) und ein weiteres Schaltventil im Ablauf vom Steuerraum (2) angeordnet ist, dadurch gekennzeichnet, dass die Schaltventile (21, 27) in Durchschalterichtung (32) gesehen über einen gemeinsamen Steller (26) betätigbar sind, wobei das erste Schaltventil (21) in Durchschalterichtung (32) einen Vorhub (33) gegenüber dem weiteren Schaltventil (27) aufweist.1.Fuel injector for injecting fuel into the combustion chamber of an internal combustion engine with a nozzle needle (3) which can be actuated in the injector body (1) between a position that releases injection openings and closes an injection opening by building up pressure / reducing pressure in a control chamber (2), the control chamber ( 2), a discharge line (6) containing a discharge throttle (7) and an inlet (8) on the high-pressure side can be acted upon on the leakage oil side, which simultaneously supplies fuel to a nozzle chamber (15) under high pressure, a first switching valve (21) in the high-pressure inlet ( 8) before its branching in the control chamber inlet from the nozzle inlet (17) and a further switching valve in the outlet from the control chamber (2), characterized in that the switching valves (21, 27) seen in the switching direction (32) via a common actuator (26) Can be actuated, the first switching valve (21) in the switching direction (32) Advance stroke (33) compared to the other switching valve (27).
2. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass das erste Schaltventil (21) und das weitere Schaltventil (27) jeweils als 2/2 -Wege- Ventile ausgeführt sind.2. Fuel injector according to claim 1, characterized in that the first switching valve (21) and the further switching valve (27) are each designed as 2/2 way valves.
3. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass die Düsennadel (3) durch ein Federelement (11) beaufschlagt ist, dessen Schließkraft auf den Düsenöffnungsdruck PT.OE eingestellt ist3. Fuel injector according to claim 1, characterized in that the nozzle needle (3) is acted upon by a spring element (11), the closing force of which is set to the nozzle opening pressure PT.OE.
4. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass der Steller (26) als ein Piezoaktor ausgebildet ist.4. Fuel injector according to claim 1, characterized in that the actuator (26) is designed as a piezo actuator.
5. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass der Steller (26) als ein Magnetventil beschaffen ist.5. Fuel injector according to claim 1, characterized in that the actuator (26) is designed as a solenoid valve.
6. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass in Öffnungsstel- lung (23) des ersten Schaltventils (21) der Steuerraum (2) und der Düsenraum (15) ü- ber einen hochdruckseitigen Zulauf (8, 17) mit der Hochdruckquelle (20) verbunden sind, die Düsennadel (3) jedoch noch geschlossen ist. 6. Fuel injector according to claim 1, characterized in that in the open position (23) of the first switching valve (21) the control chamber (2) and the nozzle chamber (15) via an inlet on the high pressure side (8, 17) with the high pressure source ( 20) are connected, but the nozzle needle (3) is still closed.
7. Kraftstoffinjektor gemäß Anspruch 6, dadurch gekennzeichnet, daß bei weiterer Betätigung des ersten Schaltventils (21) über den Vorhub (33) hinaus, das weitere Schaltventil (27) in Öffnungsstellung (29) gestellt wird und der Injektor hubgesteuert ist.7. Fuel injector according to claim 6, characterized in that upon further actuation of the first switching valve (21) beyond the preliminary stroke (33), the further switching valve (27) is placed in the open position (29) and the injector is stroke-controlled.
8. Kraftstoffinjektor gemäß Anspruch 1, dadurch gekennzeichnet, dass bei Betätigung des ersten Schaltventils (21) und des weiteren Schaltventils (27) in Durchschalterichtung (32) beide Schaltventile (21, 27) in Öffnungsstellung (23, 29) fahren, der Steuerraum (2) nicht wirksam ist und der Injektor druckgesteuert wird. 8. The fuel injector according to claim 1, characterized in that when the first switching valve (21) and the further switching valve (27) are actuated in the switching direction (32), both switching valves (21, 27) move into the open position (23, 29), the control chamber ( 2) is not effective and the injector is pressure controlled.
EP02750826A 2001-07-04 2002-07-04 Fuel injector having two-way valve control Withdrawn EP1415082A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10132248 2001-07-04
DE10132248A DE10132248C2 (en) 2001-07-04 2001-07-04 Fuel injector with 2-way valve control
PCT/DE2002/002431 WO2003004863A1 (en) 2001-07-04 2002-07-04 Fuel injector having two-way valve control

Publications (1)

Publication Number Publication Date
EP1415082A1 true EP1415082A1 (en) 2004-05-06

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Application Number Title Priority Date Filing Date
EP02750826A Withdrawn EP1415082A1 (en) 2001-07-04 2002-07-04 Fuel injector having two-way valve control

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US (1) US20040011891A1 (en)
EP (1) EP1415082A1 (en)
JP (1) JP2004521263A (en)
DE (1) DE10132248C2 (en)
WO (1) WO2003004863A1 (en)

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CH704454A1 (en) * 2011-02-08 2012-08-15 Liebherr Machines Bulle Sa Injection apparatus for a fluid.
DE102012012420A1 (en) 2012-06-25 2014-01-02 L'orange Gmbh Injector and fuel injection device with such
DE102016205955B4 (en) * 2016-04-08 2022-10-27 Ford Global Technologies, Llc Direct-injection internal combustion engine with a fuel supply system comprising a high-pressure line and method for operating such an internal combustion engine
CN114165373A (en) * 2021-12-17 2022-03-11 中国船舶重工集团公司第七一一研究所 Fuel injector and common rail system

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JPH0759919B2 (en) * 1986-04-04 1995-06-28 日本電装株式会社 Fuel injection controller for diesel engine
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Also Published As

Publication number Publication date
US20040011891A1 (en) 2004-01-22
DE10132248C2 (en) 2003-05-28
DE10132248A1 (en) 2003-01-23
WO2003004863A1 (en) 2003-01-16
JP2004521263A (en) 2004-07-15

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