EP1421274A1 - Fuel injection device for internal combustion engines - Google Patents

Fuel injection device for internal combustion engines

Info

Publication number
EP1421274A1
EP1421274A1 EP02758074A EP02758074A EP1421274A1 EP 1421274 A1 EP1421274 A1 EP 1421274A1 EP 02758074 A EP02758074 A EP 02758074A EP 02758074 A EP02758074 A EP 02758074A EP 1421274 A1 EP1421274 A1 EP 1421274A1
Authority
EP
European Patent Office
Prior art keywords
valve
injection
pressure
fuel injection
injection device
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Withdrawn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
EP02758074A
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 EP1421274A1 publication Critical patent/EP1421274A1/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Withdrawn legal-status Critical Current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
    • F02M63/0012—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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/12—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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
    • F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
    • F02M59/105—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive hydraulic drive
    • 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
    • F02M63/0049—Combined valve units, e.g. for controlling pumping chamber and injection valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
    • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails

Definitions

  • the invention is based on a fuel injection device according to the preamble of claim 1.
  • control chamber is connected via a 2/2-way valve can be connected to a relief line.
  • Another 2/2 way valve is used to activate a pressure intensifier, which is used to generate a second higher injection pressure.
  • the fuel injection device of the invention with the characterizing features of claim 1 has, in contrast, 'that the switching valve and the valve assembly are actuated by a single actuator, and the advantage of such an actuator can be saved.
  • a preferred embodiment of the invention results from claim 4.
  • the main injection can be realized with the first relief valve and a post-injection can be realized with the second relief valve.
  • the two relief valves connected in series can advantageously be integrated into a ball valve with a double seat.
  • Fig. 1 shows the essential components of a fuel injection device according to the invention with a common actuator for controlling the
  • FIG. 2 is a diagram indicating the actuating path (S) of the common actuator, the injection pressure (P) and the stroke (h) of the valve member for the fuel injection device shown in FIG. 1 over the time axis.
  • the fuel injection device 1 for internal combustion engines shown in FIG. 1 comprises a high pressure accumulator 2 (common rail) in which fuel is stored under a first injection pressure P 1.
  • the fuel is discharged from the high-pressure accumulator 2 via pressure lines 3 and injection lines 4 to the individual injection valves (injectors) 5 projecting into the combustion chamber of the internal combustion engine to be supplied, only one of which is shown in FIG. 1.
  • a piston-shaped valve member (nozzle needle) 7 with a conical valve sealing surface 8 is slidably mounted in an axial guide bore 6 of the injection valve 5, which is pressed by a closing spring 9 against a conical valve seat surface 10 of the valve housing and closes the injection openings 11 provided there.
  • the Injection line 4 opens in injection valve 5 into an annular nozzle chamber 12, from which an annular gap running between guide bore 6 and valve member 7 leads to valve seat surface 10.
  • the valve member 7 has a first control surface 13 designed as a pressure shoulder, on which the fuel supplied via the injection line 4 acts on the valve member 7 in the opening direction (ie inwards).
  • the end face of the valve member 7 facing away from the valve sealing surface 8 forms a second control surface 14 which delimits a control chamber 15 and acts in the valve closing direction.
  • the control chamber 15 is connected to the injection line 4 via a Z throttle 16 and can be connected to a relief line (leak oil) 19 via an A throttle 17 and a valve arrangement 18.
  • the valve arrangement 18 comprises two relief valves 20, 21 connected in series, each of which is designed as a 2/2-way valve.
  • the second control surface 14 is larger than the first control surface 13, so that when the valve arrangement 18 is closed, ie at the same pressure in the nozzle chamber 12 and in the control chamber 15, the valve member 7 closes the injection openings 11.
  • the Z-throttle 16 is smaller than the A-throttle 17, so that when the valve arrangement 18 is open, the pressure prevailing in the control chamber 15 is reduced via the relief line 19 and the pressure prevailing in the nozzle chamber 12 is now sufficient to counteract the action of the valve member 7 Open spring 9.
  • a local pressure transmission unit is provided with a transmission piston 23 which can be axially displaced against the action of a return spring 22 and which has a primary chamber 24 on the primary side, second a secondary chamber 25 on the intestine side and a pressure chamber 26 on the pressure side.
  • the primary chamber 24 is connected directly, the secondary chamber 25 to the pressure line 3 via a throttle 27 and the pressure chamber 26 via a check valve 28, the injection line 4 being connected by the
  • Pressure chamber 26 comes off.
  • the secondary chambers 25 can be connected to the relief line 19 via a switching valve 29 designed as a 2/2-way valve. When the switching valve 29 is closed, the fuel pressure Pl of the pressure accumulator 2 prevails in all three chambers 24, 25, 26, so that the
  • Translation piston 23 is pressed into its starting position by the return spring 22. If the secondary chambers 25 are relieved of pressure by opening the switching valve 29, the transmission piston 23 is displaced in the compression direction and the fuel in the pressure chamber 26 is compressed to a higher injection pressure P2 in accordance with the piston cross-sectional ratio in the primary and pressure chambers 24, 26.
  • the check valve 28 prevents the backflow of. compressed fuel back into the pressure line 3.
  • a common piezoelectric actuator 30 which actuates the valves 20, 21, 29 from different actuation paths.
  • the travel S2 required to open the switching valve 29 is greater than the travel S1 required to open the first relief valve 20 and smaller than the travel S3 required to close the second relief valve 21, ie Sl ⁇ S2 ⁇ S3.
  • the actuator 30 comprises an actuator 31 which, in the initial position of the actuator 30 shown in FIG. element 33 of the first relief valve 20 by the actuating path S1, from the actuating element 34 of the switching valve 29 by the actuating path S2 and from the actuating element 35 of the second relief valve 21 by the actuating path S3.
  • the start of the injection process is initiated at time t0 by displacing the actuating element 31 by the actuating path S1.
  • the first relief valve 20 is opened and the control chamber 15 is relieved of pressure.
  • the fuel pressure Pl of the pressure accumulator 2 prevailing in the nozzle chamber 12 is now sufficient to open the valve member 7 against the action of the closing spring 9, so that fuel with the fuel pressure Pl emerges from the injection openings 11.
  • the switching valve 29 is opened by shifting the first actuating element 31 by the actuating travel S2, and the secondary chamber 25 is thereby relieved of pressure.
  • a higher injection pressure builds up in the pressure chamber 26 and thus also in the nozzle chamber 12, as a result of which the valve member 7 is actuated to the maximum stroke h max and the injection is continued with the higher injection pressure.
  • the maximum injection pressure P ma ⁇ results from the piston cross-sectional ratio in the primary and pressure chamber 24, 26.
  • the control element 31 At a point in time t2 at which the pressure prevailing in the nozzle chamber 12 is still higher than the fuel pressure Pl of the pressure accumulator 2, the control element 31, the second relief valve 21 is closed by the actuating path S3.
  • the control chamber 15 is no longer depressurized, so that the valve member 7 closes the injection openings 11.
  • control chamber 15 is again depressurized, and the valve member 7 opens so that the fuel returns with the fuel prevailing in the injection chamber 12, e.g. with P2, is injected.
  • the injection process is ended at time t4 by returning the actuating element 31 to its initial position. This closes both the switching valve 29, whereby 'the secondary chamber 25 is no longer depressurized and consequently the booster piston 23 by the return spring

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 (1) for internal combustion engines, comprising several injection valves (5) arranged respectively in a fuel injection line (4). Each injection valve (5) comprises an injection chamber (12) and a control chamber which are connected to the injection line (4), a valve member (7) which controls the injection inlets (11) of the injection chamber (12) and which can be actuated by a first control surface (13) disposed in the injection chamber (12) and operating in the direction of the valve opening, and by means of a second control surface (14) in the control chamber (15) operating in the closing direction of the valve; also comprising a switch valve (29) for alternating between a low and a high injection pressure and a valve arrangement (18) for controlling the pressure prevailing in the control chamber (15). According to the invention, a common actuating drive (30) is provided for the valve arrangement (18) and the switch valve (29). The actuating path (S2) of the common actuating drive (30) necessary for opening the switch valve (29) is greater than the actuating path (SI) necessary for opening the valve arrangement.

Description

Kraftstoffeinspritzvorrichtuncf für Brennkraftmaschinen Fuel injection device for internal combustion engines
Beschreibungdescription
Stand der TechnikState of the art
Die Erfindung geht aus von einer Kraftstoffeinsprit zvor- richtung nach der Gattung des Patentanspruchs 1.The invention is based on a fuel injection device according to the preamble of claim 1.
Bei einer bekannten Kraftstoffeinspritzvorrichtung dieser Art (DE 199 10 970 AI) ist der Steuerraum über ein 2/2-We- geventil mit einer Entlastungsleitung verbindbar. Ein anderes 2/2 -Wegeventil dient zur Aktivierung eines Druck- übersetzers, mit dem ein zweiter höherer Einspritzdruck erzeugt wird.In a known fuel injection device of this type (DE 199 10 970 AI) the control chamber is connected via a 2/2-way valve can be connected to a relief line. Another 2/2 way valve is used to activate a pressure intensifier, which is used to generate a second higher injection pressure.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Kraftstoffeinspritzvorrichtung mit den kennzeichnenden Merkmalen des Patentanspruchs 1 hat demgegenüber den Vorteil, 'daß das Schaltventil und die Ventilanordnung von einem einzigen Stellantrieb betätigt werden und so ein Stellantrieb eingespart werden kann.The fuel injection device of the invention with the characterizing features of claim 1 has, in contrast, 'that the switching valve and the valve assembly are actuated by a single actuator, and the advantage of such an actuator can be saved.
Eine bevorzugte Ausführungsform der Erfindung ergibt sich aus Anspruch 4. Beispielsweise kann mit dem ersten Entlastungsventil die Haupteinspritzung und mit dem zweiten Entlastungsventil eine Nacheinspritzμng realisiert werden. Die beiden hintereinander geschalteten Entlastungsventile lassen sich vorteilhafterweise in ein Kugelventil mit Dop- pelsitz integrieren.A preferred embodiment of the invention results from claim 4. For example, the main injection can be realized with the first relief valve and a post-injection can be realized with the second relief valve. The two relief valves connected in series can advantageously be integrated into a ball valve with a double seat.
Weitere Vorteile und vorteilhafte Ausgestaltungen des Gegenstands der Erfindung sind der Beschreibung, der Zeichnung und den Ansprüchen entnehmbar.Further advantages and advantageous configurations of the subject matter of the invention can be found in the description, the drawing and the claims.
Zeichnung' Drawing '
Ein Ausführungsbeispiel der erfindungsgemäßen Kraftstoff- einspritzvorrichtung ist in der Zeichnung dargestellt und wird in der nachfolgenden Beschreibung näher erläutert . Es zeigen:An embodiment of the fuel injection device according to the invention is shown in the drawing and is explained in more detail in the following description. It demonstrate:
Fig. 1 die wesentlichen Komponenten einer erfindungsgemäßen Kraftstoffeinspritzvorrichtung mit einem gemeinsamen Stellantrieb für die zum Steuern desFig. 1 shows the essential components of a fuel injection device according to the invention with a common actuator for controlling the
Einspritzvorgangs vorgesehenen Ventile; undInjection provided valves; and
Fig. 2 ein Diagramm, das für die in Fig. 1 dargestellte Kraftstoffeinspritzvorrichtung über die Zeitachse den Stellweg (S) des gemeinsamen Stellantriebs, den Einspritzdruck (P) und den Hub (h) des Ven-*- tilglieds angibt.FIG. 2 is a diagram indicating the actuating path (S) of the common actuator, the injection pressure (P) and the stroke (h) of the valve member for the fuel injection device shown in FIG. 1 over the time axis.
Beschreibung der AusführungsbeispieleDescription of the embodiments
Die in Fig. 1 gezeigte Kraftstoffeinspritzvorrichtung 1 für Brennkraftmaschinen umfaßt einen Hochdruckspeicher 2 (Common Rail) , in dem Kraftstoff unter einem ersten Ein- spritzdruck Pl gelagert ist. Vom Hochdruckspeicher 2 wird der Kraftstoff jeweils über Druckleitungen 3 und Ein- spritzleitungen 4 zu den einzelnen, in den Brennraum der zu versorgenden Brennkraftmaschine ragenden Einspritzventilen (Injektoren) 5 abgeführt, von denen in Fig. 1 nur eines gezeigt ist.The fuel injection device 1 for internal combustion engines shown in FIG. 1 comprises a high pressure accumulator 2 (common rail) in which fuel is stored under a first injection pressure P 1. The fuel is discharged from the high-pressure accumulator 2 via pressure lines 3 and injection lines 4 to the individual injection valves (injectors) 5 projecting into the combustion chamber of the internal combustion engine to be supplied, only one of which is shown in FIG. 1.
In einer axialen Führungsbohrung 6 des Einspritzventils 5 ist ein kolbenförmiges Ventilglied (Düsennadel) 7 mit einer konischen Ventildichtfläche 8 verschiebbar gelagert, welche durch eine Schl-ießfeder 9 gegen eine konische Ventilsitzfläche 10 des Ventilgehäuses gedrückt wird und die dort vorgesehenen Einspritzöffnungen 11 verschließt . Die Einspritzleitung 4 mündet im Einspritzventil 5 in einen ringförmigen Düsenraum 12, von dem ein zwischen Führungs- bohrung 6 und Ventilglied 7 verlaufender Ringspalt bis zur Ventilsitzfläche 10 führt. Das Ventilglied 7 hat im Be- reich des Düsenraumes 12 eine als Druckschulter ausgebildete erste Steuerfläche 13, an welcher der über die Einspritzleitung 4 zugeführte Kraftstoff im Öffnungssinn (d.h. nach innen) am Ventilglied 7 angreift. Die der Ventildichtfläche 8 abgewandte Stirnseite des Ventilglieds 7 bildet eine zweite Steuerfläche 14, die einen Steuerraum 15 begrenzt und in Ventilschließrichtung wirkt. Der Steuerraum 15 ist über eine Z-Drossel 16 mit der Einspritzleitung 4 verbunden sowie über eine A-Drossel 17 und eine Ventilanordnung 18 mit einer Entlastungsleitung (Lecköl) 19 verbindbar. Die Ventilanordnung 18 umfaßt zwei in Reihe geschaltete Entlastungsventile 20, 21, die jeweils als 2/2-Wegeventile ausgebildet sind. Die zweite Steuerfläche 14 ist größer als die erste Steuerfläche 13 , so daß bei geschlossener Ventilanordnung 18, d.h. bei gleichem Druck im Düsenraum 12 und im Steuerraum 15, das Ventilglied 7 die Einspritzöffnungen 11 verschließt. Die Z-Drossel 16 ist kleiner als die A-Drossel 17, so daß bei geöffneter Ventilanordnung 18 der im Steuerraum 15 herrschende Druck über die Entlastungsleitung 19 abgebaut wird und der im Düsenraum 12 herrschende Druck nun ausreicht, um das Ventilglied 7 gegen die Wirkung der Schließfeder 9 aufzusteuern.A piston-shaped valve member (nozzle needle) 7 with a conical valve sealing surface 8 is slidably mounted in an axial guide bore 6 of the injection valve 5, which is pressed by a closing spring 9 against a conical valve seat surface 10 of the valve housing and closes the injection openings 11 provided there. The Injection line 4 opens in injection valve 5 into an annular nozzle chamber 12, from which an annular gap running between guide bore 6 and valve member 7 leads to valve seat surface 10. In the area of the nozzle chamber 12, the valve member 7 has a first control surface 13 designed as a pressure shoulder, on which the fuel supplied via the injection line 4 acts on the valve member 7 in the opening direction (ie inwards). The end face of the valve member 7 facing away from the valve sealing surface 8 forms a second control surface 14 which delimits a control chamber 15 and acts in the valve closing direction. The control chamber 15 is connected to the injection line 4 via a Z throttle 16 and can be connected to a relief line (leak oil) 19 via an A throttle 17 and a valve arrangement 18. The valve arrangement 18 comprises two relief valves 20, 21 connected in series, each of which is designed as a 2/2-way valve. The second control surface 14 is larger than the first control surface 13, so that when the valve arrangement 18 is closed, ie at the same pressure in the nozzle chamber 12 and in the control chamber 15, the valve member 7 closes the injection openings 11. The Z-throttle 16 is smaller than the A-throttle 17, so that when the valve arrangement 18 is open, the pressure prevailing in the control chamber 15 is reduced via the relief line 19 and the pressure prevailing in the nozzle chamber 12 is now sufficient to counteract the action of the valve member 7 Open spring 9.
Für jedes Einspritzventil 5 ist eine lokale Drucküberset- zungseinheit mit einem gegen die Wirkung einer Rückstellfeder 22 axial verschiebbaren Übersetzungskolben 23 vorgesehen, welcher primärseitig eine Primärkammer 24, sekun- därseitig eine Sekundärkammer 25 und druckseitig eine Druckkammer 26 begrenzt. Die Primärkammer 24 ist direkt, die Sekundärkammer 25 über eine Drossel 27 und die Druckkammer 26 über ein Rückschlagventil 28 mit der Drucklei- tung 3 verbunden, wobei die Einspritzleitung 4 von derFor each injection valve 5, a local pressure transmission unit is provided with a transmission piston 23 which can be axially displaced against the action of a return spring 22 and which has a primary chamber 24 on the primary side, second a secondary chamber 25 on the intestine side and a pressure chamber 26 on the pressure side. The primary chamber 24 is connected directly, the secondary chamber 25 to the pressure line 3 via a throttle 27 and the pressure chamber 26 via a check valve 28, the injection line 4 being connected by the
Druckkammer 26 abgeht. Über ein als 2/2-Wegeventil ausgebildetes Schaltventil 29 ist die Sekundärkämmer 25 mit der Entlastungsleitung 19 verbindbar. Bei geschlossenem Schaltventil 29 herrscht in allen drei Kammern 24, 25, 26 der Kraftstoffdruck Pl des Druckspeichers 2, so daß derPressure chamber 26 comes off. The secondary chambers 25 can be connected to the relief line 19 via a switching valve 29 designed as a 2/2-way valve. When the switching valve 29 is closed, the fuel pressure Pl of the pressure accumulator 2 prevails in all three chambers 24, 25, 26, so that the
Übersetzungskolben 23 durch die Rückstellfeder 22 in seine Ausgangslage gedrückt ist. Wird durch Öffnen des Schaltventils 29 die Sekundärkämmer 25 druckentlastet, wird der Übersetzungskolben 23 in Kompressionsrichtung verschoben und dadurch entsprechend dem Kolbenquerschnittsverhältnis in Primär- und Druckkammer 24, 26 der in der Druckkammer 26 befindliche Kraftstoff auf einen höheren Einspritzdruck P2 komprimiert. Das Rückschlagventil 28 verhindert dabei den Rückfluß von. komprimiertem Kraftstoff zurück in die Druckleitung 3.Translation piston 23 is pressed into its starting position by the return spring 22. If the secondary chambers 25 are relieved of pressure by opening the switching valve 29, the transmission piston 23 is displaced in the compression direction and the fuel in the pressure chamber 26 is compressed to a higher injection pressure P2 in accordance with the piston cross-sectional ratio in the primary and pressure chambers 24, 26. The check valve 28 prevents the backflow of. compressed fuel back into the pressure line 3.
Für die beiden Entlastungsventile 20, 21 und das Schaltventil 29 ist ein gemeinsamer piezoelektrischer Stellantrieb 30 vorgesehen, der die Ventile 20, 21, 29 ab jeweils unterschiedlichen Stellwegen betätigt. Der zum Öffnen des Schaltventils 29 erforderliche Stellweg S2 ist größer als der zum Öffnen des ersten Entlastungsventils 20 erforderliche Stellweg Sl und kleiner als der zum Schließen des zweiten Entlastungsventils 21 erforderliche Stellweg S3 , d.h. Sl < S2 < S3. Der Stellantrieb 30 umfaßt ein Stellelement 31, das in der in Fig. 1 gezeigten Ausgangsstellung des Stellantriebs 30 in Stellrichtung 32 vom Stell- element 33 des ersten Entlastungsventils 20 um den Stellweg Sl, vom Stellelement 34 des Schaltventils 29 um den Stellweg S2 und vom Stellelement 35 des zweiten Entlastungsventils 21 um den Stellweg S3 beabstandet ist . Folg- lieh werden die Stellelemente 33, 34, 35 der einzelnenFor the two relief valves 20, 21 and the switching valve 29, a common piezoelectric actuator 30 is provided which actuates the valves 20, 21, 29 from different actuation paths. The travel S2 required to open the switching valve 29 is greater than the travel S1 required to open the first relief valve 20 and smaller than the travel S3 required to close the second relief valve 21, ie Sl <S2 <S3. The actuator 30 comprises an actuator 31 which, in the initial position of the actuator 30 shown in FIG. element 33 of the first relief valve 20 by the actuating path S1, from the actuating element 34 of the switching valve 29 by the actuating path S2 and from the actuating element 35 of the second relief valve 21 by the actuating path S3. As a result, the adjusting elements 33, 34, 35 of the individual
Ventile vom Stellelement 31 ab jeweils unterschiedlichen Stellwegen mitgenommen und dadurch betätigt.Valves taken away by the actuating element 31 from different actuation paths and actuated thereby.
In Fig. 2 ist in einem Diagramm der zeitliche Ablauf des Einspritzvorgangs aufgetragen.2 shows the timing of the injection process in a diagram.
Der Beginn des Einspritzvorgangs wird zum Zeitpunkt tO durch Verschieben des Stellelements 31 um den Stellweg Sl eingeleitet. Dadurch wird das erste Entlastungsventil 20 geöffnet, und der Steuerraum 15 wird druckentlastet. Der im Düsenraum 12 herrschende Kraftstoffdruck Pl des Druckspeichers 2 reicht nun aus, um das Ventilglied 7 gegen die Wirkung der Schließfeder 9 aufzusteuern, so daß Kraftstoff mit dem Kraftstoffdruck Pl aus den Einspritzöffnungen 11 austritt . Zum Zeitpunkt tl wird durch Verschieben des ersten Stellelements 31 um den Stellweg S2 das Schaltventil 29 geöffnet und dadurch die Sekundärkammer 25 druckentlastet. In der Druckkammer 26 und damit auch im Düsenraum 12 baut sich ein höherer Einspritzdruck auf, wodurch das Ventil- glied 7 auf maximalen Hub hmax aufgesteuert wird und die Einspritzung mit dem höheren Einspritzdruck fortgesetzt wird. Der maximale Einspritzdruck Pmaχ ergibt sich aus dem Kolbenquerschnittsverhältnis in Primär- und Druckkammer 24, 26. Zu einem Zeitpunkt t2 , bei dem der im Düsenraum 12 herrschende Druck noch höher als der Kraftstoffdruck Pl des Druckspeichers 2 ist, wird durch Verschieben des Stellele- ments 31 um den Stellweg S3 das zweite Entlastungsventil 21 geschlossen. Der Steuerraum 15 ist nicht mehr druckentlastet, so daß das Ventilglied 7 die Einspritzöffnungen 11 verschließt . Zum Zeitpunkt t3-wird durch Zurückstellen des Stellelements 31 auf den Stellweg S2 das zweite EntlastungsventilThe start of the injection process is initiated at time t0 by displacing the actuating element 31 by the actuating path S1. As a result, the first relief valve 20 is opened and the control chamber 15 is relieved of pressure. The fuel pressure Pl of the pressure accumulator 2 prevailing in the nozzle chamber 12 is now sufficient to open the valve member 7 against the action of the closing spring 9, so that fuel with the fuel pressure Pl emerges from the injection openings 11. At time t1, the switching valve 29 is opened by shifting the first actuating element 31 by the actuating travel S2, and the secondary chamber 25 is thereby relieved of pressure. A higher injection pressure builds up in the pressure chamber 26 and thus also in the nozzle chamber 12, as a result of which the valve member 7 is actuated to the maximum stroke h max and the injection is continued with the higher injection pressure. The maximum injection pressure P ma χ results from the piston cross-sectional ratio in the primary and pressure chamber 24, 26. At a point in time t2 at which the pressure prevailing in the nozzle chamber 12 is still higher than the fuel pressure Pl of the pressure accumulator 2, the control element 31, the second relief valve 21 is closed by the actuating path S3. The control chamber 15 is no longer depressurized, so that the valve member 7 closes the injection openings 11. At time t3-by resetting the control element 31 to the control path S2, the second relief valve
21 wieder geöffnet. Der Steuerraum 15 ist wieder druckentlastet, und das Ventilglied 7 öffnet, so daß der Kraftstoff mit dem in der Einspritzkammer 12 herrschenden Kraftstoff rück, z.B. mit P2, eingespritzt wird.21 opened again. The control chamber 15 is again depressurized, and the valve member 7 opens so that the fuel returns with the fuel prevailing in the injection chamber 12, e.g. with P2, is injected.
Der Einspritzvorgang wird zum Zeitpunkt t4 durch Zurückstellen des Stellelements 31 in seine Ausgangslage beendet. Damit schließen sowohl das Schaltventil 29, wodurch ' die Sekundärkammer 25 nicht mehr druckentlastet ist und folglich der Übersetzerkolben 23 durch die RückstellfederThe injection process is ended at time t4 by returning the actuating element 31 to its initial position. This closes both the switching valve 29, whereby 'the secondary chamber 25 is no longer depressurized and consequently the booster piston 23 by the return spring
22 in seine Ausgangslage gedrückt wird, als auch das erste Entlastungsventil 20, wodurch der nun nicht mehr druckentlastete Steuerraum 15 über die Druckkammer 26 mit Kraftstoff aus dem Druckspeicher 2 gefüllt wird und das Ventil- glied 7 schließt. 22 is pressed into its initial position, as is the first relief valve 20, as a result of which the control chamber 15, which is now no longer depressurized, is filled with fuel from the pressure accumulator 2 via the pressure chamber 26 and the valve member 7 closes.

Claims

Patentansprüche claims
1. Kraftstoffeinspritzvorrichtung (1) für Brennkraftma- schinen, mit mehreren jeweils in einer Einspritzleitung (4) des Kraftstoffs vorgesehenen Einspritzventilen (5), wobei jedes Einspritzventil (5) einen Düsenraum (12) und einen' Steuerraum (15) , die beide mit der Einspritzleitung (4) verbunden sind, ein die Einspritzöffnungen (11) des Düsenraums (12) steuerndes Ventilglied (7) , 'das über eine im Düsenraum (12) befindliche, in Ventilöffnungsrichtung wirkende erste Steuerfläche (13) und über eine im Steuerraum (15) befindliche, in Ventilschließrichtung wirkende zweite Steuerfläche (14) betätigbar ist, ein Schaltventil (29) zum Umschalten zwischen einem tieferen und einem höheren' Einspritzdruck und eine Ventilanordnung (18) zum Steuern des im Steuerraum (15) herrschenden Drucks aufweist, dadurch gekennzeichnet, daß für die Ventilanordnung (18) und das Schaltventil (29) ein gemeinsamer Stellantrieb (30) vorgesehen ist und daß der zum Öffnen des Schaltventils (29) erforderliche Stellweg (S2) des gemeinsamen Stellantriebs (30) größer als 'der zum Öffnen der Ventilanordnung1. Fuel injection device (1) machines for Brennkraftma-, with a plurality of each in an injection line (4) of the fuel provided for the injection valves (5), wherein each injection valve (5) a nozzle chamber (12) and a 'control chamber (15), both with are connected to the injection line (4), a valve member (7) controlling the injection openings (11) of the nozzle chamber (12), 'via a first control surface (13) located in the nozzle chamber (12) and acting in the valve opening direction and via a in the control chamber ( 15) located, acting in the valve closing direction, has a control valve (14), a switching valve (29) for switching between a lower and a higher ' injection pressure and a valve arrangement (18) for controlling the pressure prevailing in the control chamber (15), characterized that for the valve arrangement (18) and the switching valve (29) a common actuator (30) is provided and that the opening of the switching valve (29) e rforderliche travel range (S2) of the common actuator (30) is greater than 'of the valve assembly to open
(18) erforderliche Stellweg (Sl) ist.(18) required travel (Sl).
2. Kraftstoffeinspritzvorrichtung nach Anspruch 1, da- durch gekennzeichnet, daß der zum erneuten Schließen der Ventilanordnung (18) erforderliche Stellweg (S3) des gemeinsamen Stellantriebs (30) größer als der zum Öffnen des Schaltventils (29) erforderliche Stellweg (S2) ist.2. Fuel injection device according to claim 1, characterized in that the travel (S3) of the common actuator (30) required to re-close the valve arrangement (18) is greater than that required travel (S2) to open the switching valve (29).
3. Kraftstoffeinspritzvorrichtung nach Anspruch 1 oder 2, 05. dadurch gekennzeichnet, daß die Ventilanordnung (18) ein vom gemeinsamen Stellantrieb (30) betätigbares erstes Entlastungsventil (20) aufweist und daß der zum Öffnen des Schaltventils (29) erforderliche Stellweg (S2) größer als der zum Öffnen des ersten Entlastungs- 10 ventils (20) erforderliche Stellweg (Sl) ist.3. Fuel injection device according to claim 1 or 2, 05 . characterized in that the valve arrangement (18) has a first relief valve (20) which can be actuated by the common actuator (30) and that the actuating path (S2) required to open the switching valve (29) is greater than that for opening the first relief valve (20) 20) required travel (Sl).
4. Kraftstoffeinspritzvorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß die Ventilanordnung (18) ein vom gemeinsamen Stellantrieb (30) betätigbares zweites4. Fuel injection device according to claim 3, characterized in that the valve arrangement (18) a second actuatable by the common actuator (30)
15 Entlastungsventil (21) aufweist, das in Reihe zum ersten Entlastungsventil (20) geschaltet ist, und daß der zum Schließen des zweiten Entlastungsventils (21) erforderliche Stellweg (S3) des gemeinsamen Stellantriebs (30) größer als der zum Öffnen des15 relief valve (21), which is connected in series with the first relief valve (20), and that the travel (S3) required for closing the second relief valve (21) of the common actuator (30) is greater than that for opening the
20 Schaltventils (29) erforderliche Stellweg (S3) ist.20 switching valve (29) required travel (S3).
5. Kraftstoffeinspritzvorrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß der oder die Ventilkörper der Ventilanordnung (18)5. Fuel injection device according to one of the preceding claims, characterized in that the valve body or the valve assembly of the valve arrangement (18)
25 und des Schaltventils (29) mit dem gemeinsamen Stellantrieb (30) ab jeweils unterschiedlichen Stellwegen bewegungsgekoppelt sind.25 and the switching valve (29) with the common actuator (30) are each coupled from different actuation paths.
6. Kraftstoffeinspritzvorrichtung nach einem der vor- 30 hergehenden Ansprüche, dadurch gekennzeichnet, daß das Schaltventil (29) und/oder das erste Entlastungsventil (20) und/oder das zweite Entlastungs- ventil (21) jeweils als 2/2-Wegeventil ausgebildet sind.6. Fuel injection device according to one of the preceding 30 claims, characterized in that the switching valve (29) and / or the first relief valve (20) and / or the second relief valve valve (21) are each designed as a 2/2-way valve.
7. Kraftstoffeinspritzvorrichtung nach einem der vorher- gehenden Ansprüche, dadurch gekennzeichnet, daß der gemeinsame Stellantrieb (30) als piezoelektrischer Stellantrieb ausgebildet ist.7. Fuel injection device according to one of the preceding claims, characterized in that the common actuator (30) is designed as a piezoelectric actuator.
8. Kraftstoffeinspritzvorrichtung nach einem der vorher- gehenden Ansprüche, dadurch gekennzeichnet, daß zumindest der tiefere Einspritzdruck (Pl) in einem zentralen Druckspeicher (2) gespeichert ist.8. Fuel injection device according to one of the preceding claims, characterized in that at least the lower injection pressure (Pl) is stored in a central pressure accumulator (2).
9. ' Kraftstoffeinspritzvorrichtung nach einem der vorher- gehenden Ansprüche, dadurch gekennzeichnet, daß die9. ' Fuel injection device according to one of the preceding claims, characterized in that the
Einspritzleitung (4) sowohl über ein Rückschlagventil (28) mit dem tieferen Einspritzdruck (Pl) als auch mit der Druckkammer (26) eines durch das Schaltventil (29) aktivierbaren Druckübersetzungskolbens (23) verbunden ist. Injection line (4) is connected both via a check valve (28) to the lower injection pressure (Pl) and to the pressure chamber (26) of a pressure booster piston (23) which can be activated by the switching valve (29).
EP02758074A 2001-08-22 2002-07-05 Fuel injection device for internal combustion engines Withdrawn EP1421274A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10141111A DE10141111B4 (en) 2001-08-22 2001-08-22 Fuel injection device for internal combustion engines
DE10141111 2001-08-22
PCT/DE2002/002462 WO2003019000A1 (en) 2001-08-22 2002-07-05 Fuel injection device for internal combustion engines

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EP (1) EP1421274A1 (en)
JP (1) JP2005500475A (en)
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Publication number Priority date Publication date Assignee Title
JP4345096B2 (en) * 2001-09-28 2009-10-14 株式会社デンソー Fuel injection device
US20050039724A1 (en) * 2001-10-16 2005-02-24 Hiroyuki Ishida Fuel injection device and diesel engine having the same, and fuel injection device controlling method
US7059301B2 (en) 2003-02-20 2006-06-13 Caterpillar Inc. End of injection rate shaping
US20060202053A1 (en) * 2005-03-09 2006-09-14 Gibson Dennis H Control valve assembly and fuel injector using same

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GB1557179A (en) * 1975-09-16 1979-12-05 Lucas Cav Liquid fuel pumping apparatus
AT408133B (en) * 1990-06-08 2001-09-25 Avl Verbrennungskraft Messtech INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES
JP2885076B2 (en) * 1994-07-08 1999-04-19 三菱自動車工業株式会社 Accumulator type fuel injection device
US5732679A (en) * 1995-04-27 1998-03-31 Isuzu Motors Limited Accumulator-type fuel injection system
GB9616521D0 (en) * 1996-08-06 1996-09-25 Lucas Ind Plc Injector
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US7096854B2 (en) 2006-08-29
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JP2005500475A (en) 2005-01-06
US20060042596A1 (en) 2006-03-02
DE10141111B4 (en) 2005-10-13

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