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EP1283954A1 - Fuel injection system for an internal combustion engine - Google Patents

Fuel injection system for an internal combustion engine

Info

Publication number
EP1283954A1
EP1283954A1 EP01940207A EP01940207A EP1283954A1 EP 1283954 A1 EP1283954 A1 EP 1283954A1 EP 01940207 A EP01940207 A EP 01940207A EP 01940207 A EP01940207 A EP 01940207A EP 1283954 A1 EP1283954 A1 EP 1283954A1
Authority
EP
European Patent Office
Prior art keywords
valve
fuel
valve member
pressure chamber
bore
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Withdrawn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
EP01940207A
Other languages
German (de)
French (fr)
Inventor
Matthias Beck
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 EP1283954A1 publication Critical patent/EP1283954A1/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Withdrawn legal-status Critical Current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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/46—Valves
    • F02M59/466—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means
    • F02M59/468—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means using piezoelectric operating means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • 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
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/70—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger
    • F02M2200/703—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic
    • F02M2200/704—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic with actuator and actuated element moving in different directions, e.g. in opposite directions

Definitions

  • the invention is based on a fuel injection device for an internal combustion engine.
  • a fuel injection device in the form of a pump-nozzle unit is known from the published patent application DE 35 23 536 AI.
  • a pump-nozzle unit is provided for each combustion chamber of the internal combustion engine, in which a pump unit, a control valve and an injection valve are integrated in one unit.
  • the pump unit consists of a pump piston that is driven synchronously with the internal combustion engine and immersed in a pump work space, where it displaces the fuel therein under high pressure.
  • the pump work space is connected to the fuel injection valve, which opens at a certain fuel pressure and thus injects fuel under high pressure into the combustion chamber of the internal combustion engine.
  • the control valve arranged in the housing of the pump-injector unit opens and closes a connection between the pump work chamber and a fuel supply system in which the fuel pressure is low and which both supplies fuel to the pump-injector unit and absorbs excess fuel. If the control valve is open, the fuel is led from the pump work space into the fuel supply system, so that no fuel pressure can build up in the injection valve and thus there is no injection. If the control valve closes, a corresponding pressure can build up and fuel is injected into the combustion chamber of the internal combustion engine. In this way, the start of the injection and the duration of the injected fuel quantity can be controlled.
  • valve member is acted upon by a spring in the opening direction and held in the closed position by a controllable counterforce, which is applied here by an electromagnet. If the electromagnet is switched off, the spring pushes the valve member in the opening direction and the connection from the high pressure to the low pressure area is opened.
  • the valve member of the control valve has in one embodiment shown in DE 35 23 536 AI a valve seat and a downstream in the flow direction from the high pressure area to the low pressure area a throttle collar on the valve member, through which the flow cross section in a certain range largely independent of the stroke of the valve member is.
  • the known valve member has the disadvantage that when the valve member opens, a hydraulic force acts on the valve sealing surface, which is added to the opening force of the spring in the course of the opening stroke movement of the valve member. As a result, it is difficult to control the counter force of the electromagnet according to the requirements so that the valve member is held in a position in which the flow of fuel is throttled.
  • the valve member has a relatively large stroke range in which the flow cross-section is independent of the stroke.
  • the throttle gap is formed between a cylindrical section of the bore and the valve member and, viewed in the direction of flow of the fuel from the high-pressure chamber to the low-pressure chamber, lies upstream of the valve seat. The fuel flow from the high-pressure chamber is first passed through this throttle gap and then past the valve sealing surface to the low-pressure chamber, so that there is already a low fuel pressure at the valve sealing surface.
  • valve member can also move to a third, throttling position in an easily controllable manner, so that a pre-injection with lower pressure is possible through the injection valve.
  • FIG. 1 shows a longitudinal section through a fuel injection device
  • Figure 2 is an enlargement of Figure 1 in the area of a control valve
  • Figure 3 is a schematic representation of the flow cross-section controlled by the control valve as a function of the stroke of the valve member. Description of the embodiment
  • FIG. 1 shows a longitudinal section through a fuel injection device according to the invention in the form of a pump-nozzle unit, as is used for injecting fuel into the combustion chamber of an internal combustion engine, in particular a self-igniting internal combustion engine.
  • the pump-nozzle unit contains all components necessary for an injection, that is a high-pressure generating pump unit 39, an injection valve 1 and a control valve 11 which controls the start and the end of the injection.
  • FIG. 2 shows an enlargement of FIG. 1 in the area of the control valve 11.
  • the structure of the individual components is first explained and then their function as part of the pump-nozzle unit is explained.
  • the injection valve 1 comprises an injection valve body 2, which is essentially designed as a cylinder with a stepped diameter and projects with one end into the combustion chamber of an internal combustion engine, not shown in the drawing.
  • a blind bore 9 is formed, the closed end of which faces the combustion chamber and at which end at least one injection opening 7 is formed which connects the blind bore 9 to the combustion chamber of the internal combustion engine.
  • a valve needle 3 is arranged in the blind bore 9, which is longitudinally displaceable against the force of a closing spring 5 and which opens and closes the at least one injection opening 7 through its opening stroke movement.
  • the valve needle 3 is surrounded by a pressure chamber 8 formed in the injection valve body 2, which continues as an annular channel surrounding the valve needle 3 up to the injection openings 7 and can be filled with fuel under high pressure via a high pressure channel 10 formed in the injection valve body 2.
  • a cylinder-shaped valve body 12 is arranged facing away from the combustion chamber and has an end face on the injection valve body 2 and the other end facing away from the combustion chamber comes into contact with a pump body 40, the injection valve body 2, valve body 12 and pump body 40 being connected by a valve Drawing, not shown, are braced against each other in the axial direction.
  • the high-pressure channel 10 formed in the injection valve body 2 continues in the axial direction through the entire valve body 12 into the pump body 40.
  • a bore 26 is formed in the valve body 12 as part of the control valve 11 in the axial direction, which is divided into a larger-diameter sealing section 126 and a smaller-diameter guide section 226, which is closed toward the combustion chamber, one at the transition between the two sections 126, 226 is designed as a valve seat 22 serving as an annular shoulder.
  • a valve member 14 is arranged in the bore 26, which is sealingly guided in the sealing section 126 of the bore 26 and which tapers towards the combustion chamber to form a valve sealing surface 24 and projects into the guide section 226 of the bore 26. Towards the end of the valve member 14 on the combustion chamber side, it increases in diameter again and merges into a section 214 which is guided in the guide section 226 of the bore 26.
  • a spring 27 is arranged under prestress, which acts on the valve member 14 away from the combustion chamber.
  • the sealingly guided section 114 of the valve member 14 is surrounded by a high-pressure space 16 formed in the valve body 12, which is connected to the high-pressure channel 10 via a connecting bore 20.
  • the control valve 11 opens and closes the connection to a low-pressure chamber 18, which is formed by the tapering of the valve member 14 and the guide branch formed between the sections 114 and 214 of the valve member 14. section 226 of the bore 26 is formed.
  • the low pressure chamber 18 is connected to a fuel supply system 58 via an inlet channel 29.
  • the fuel supply system 58 comprises a tank 66, from which fuel is conveyed into the low-pressure chamber 18 via a low-pressure line 60 by means of a feed pump 62.
  • a pressure relief valve 64 is arranged parallel to the feed pump 62 and ensures that fuel can flow back into the tank 66 from the low pressure space 18 when a certain threshold pressure is exceeded.
  • the end face 28 of the valve member 14 facing away from the combustion chamber extends into a control chamber 30 which is formed in a pump body 40 and is filled with fuel. Via the fuel pressure in the control chamber 30, a hydraulic force can be applied to the end face 28 of the valve member 14, which is directed counter to the force of the spring 27, so that the valve member 14 in the bore 26 moves in the longitudinal direction controlled by the fuel pressure in the control chamber 30 leaves .
  • the control chamber 30 is connected via a connecting bore 33 to a spring chamber 38, which spring chamber 38 is delimited by the closed end of a guide bore 37 and the end face of a control piston 32, which is sealingly longitudinally displaceable in the guide bore 37.
  • the control piston 32 is acted upon by a return spring 36 arranged under prestress in the spring chamber 38 and is connected on its end face facing away from the spring chamber 38 to a piezo actuator 34, which changes its extension by means of a suitable energization and thus the control piston 32 in the guide bore 37 can move.
  • the control piston 32 displaces fuel from the spring chamber 38 during its longitudinal movement and presses the fuel through the connecting bore 33 into the control chamber 30, so that there the pressure and thus also the hydraulic force on the end face 28 of the valve member 14 changes accordingly.
  • a throttle section 21 is formed in the bore 26, which has a somewhat larger diameter than the sealing section 126 of the bore 26.
  • a narrow throttle gap 23 designed as an annular gap is formed between the throttle section 21 of the bore 26 and the outer surface of the valve member 14.
  • the pump piston 42 is in its upper reversal point, so that the pump working space 48 has its maximum volume.
  • the pump piston 42 is moved into the pump work chamber 48 by a mechanism, not shown in the drawing, so that it compresses the fuel located in the pump work chamber 48 and displaces it into the high-pressure channel 10.
  • the piezo actuator 34 is energized so that it changes its length and moves the control piston 32 against the force of the return spring 36 into the spring chamber 38.
  • the fuel thus displaced from the spring chamber 38 increases the fuel pressure in the control chamber 30, so that the force on the end face 28 of the valve member 14 also increases accordingly to such an extent that it becomes greater than the force of the spring 27 regulated so that the control edge 25 dips into the throttle section 21 without the valve sealing surface 24 coming into contact with the valve seat 22.
  • the fuel which can flow practically unthrottled from the high-pressure duct 10 via the high-pressure chamber 16 into the low-pressure chamber 18 at the start of the delivery movement of the pump piston 42, is now throttled through the throttle gap 23, so that a certain pre-injection pressure is established in the high-pressure chamber 16 and in the high-pressure duct 10 , which depends on how large the delivery rate of the pump piston 42 and how strong the throttling effect of the throttle gap 23.
  • the throttling of the fuel pressure takes place in the throttle gap 23, so that the pressure in the fuel flow to the low pressure chamber 18 has already dropped when the fuel reaches the valve sealing surface 24. Therefore, there are only slight hydraulic forces on the valve sealing surface 24 and therefore also no forces that are difficult to control in the opening direction on the valve member 14.
  • the pre-injection pressure in the high-pressure channel 10 and thus also in the pressure chamber 8 of the injection valve 1 is matched to the force of the closing spring 5, which holds the valve needle 3 in the closed position, so that the hydraulic force on the valve needle 3 is sufficient to close the valve needle 3 in the open position move and so open the injection openings 7. Since the pre-injection pressure is clearly below the maximum injection pressure, only a small amount of fuel is injected into the combustion chamber (pre-injection).
  • the control piston 32 further increases the pressure in the control chamber 30 through the piezo actuator 34 until the valve member 14 comes into contact with the valve sealing surface 24 on the valve seat 22 due to the hydraulic force on the end face 28.
  • the connection of the high-pressure chamber 16 to the low-pressure chamber 18 is interrupted, and the maximum pressure that can be generated by the pump piston 42 acts in the high-pressure channel 10 and in the pressure chamber 8.
  • the injection is now carried out with a significantly higher injection pressure and thus with a higher injection rate.
  • the main injection can be continued at the longest until the pump piston 42 has reached its lower reversal point and all the fuel that can be displaced by the pump piston 42 is conveyed into the high-pressure channel 10. Most of the time, however, the main injection is terminated much earlier, since less fuel is required in the combustion chamber and secondly a precisely defined end of the injection is aimed for. This is done in that the pressure in the control chamber 30 is reduced, controlled by the piezo actuator 34. The force of the spring 27 now predominates. the opposite of the hydraulic force on the end face 28 of the valve member 14, and the valve member 14 is moved in the direction of the control chamber 30 until it comes to rest on the wall of the control chamber 30.
  • the high-pressure channel 10 is also connected to the low-pressure chamber 18 via the high-pressure chamber 16, so that the pressure in the pressure chamber 8 also drops and the valve needle 3 closes the injection openings 7 by the closing spring 5.
  • the remaining amount of fuel that the pump piston 42 delivers after the end of the injection before it reaches the lower reversal point is delivered into the low-pressure line 60 and from there via the pressure relief valve 64 into the tank 66.
  • valve member 14 The arrangement of the valve member 14, the control piston 32 and the pump piston 44 with respect to the injection valve 1 shown in the drawing is not required in this way for the function of the pump-nozzle unit. Provision can also be made for orienting one or more of these elements in a different way, if it should be expedient.
  • the valve member 14 and thus the bore 26 can also be arranged perpendicular to the longitudinal axis of the nozzle needle 3.

Landscapes

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

Abstract

The invention relates to a fuel injection system comprising a pump assembly (39) which feeds high pressure fuel to a high pressure conduit (10) connected to an injection valve (1), as well as a control valve (11) within which a valve member (14) exhibiting the shape of a piston and having a sealing segment (114) is guided in the bore (26), said sealing segment (114) being surrounded by a high pressure chamber (16) connected to the pump working space (48). An end of the valve member (14) protrudes in a low pressure chamber (18) connected to a fuel supply system (58). The bore (26) has a valve seat (22) which co-operates with a valve sealing face (24) formed on the valve member (14) for controlling the connection of the high pressure chamber (16) and the low pressure chamber (18). Concerning the flow direction of the fuel from the high pressure chamber (16) to the low pressure chamber (18), a throttle section (21) which is situated in the bore (26) upstream from the valve seat (22) forms with the sealing segment (114) of the valve member (14) a throttle slit (23) and therefore limits the fuel flow during the opening stroke in a stroke area of the valve member (14) so that no extra hydraulic force affects the valve member (14) during the opening stroke of said valve member (14).

Description

Kraftstoffeinspritzvorrichtung für eine BrennkraftmaschineFuel injection device for an internal combustion engine
Stand der TechnikState of the art
Die Erfindung geht von einer Kraftstoffeinspritzvorrichtung für eine Brennkraftmaschine aus . Eine solche Kraftstoffeinspritzvorrichtung in Form einer Pumpe-Düse-Einheit ist aus der Offenlegungsschrift DE 35 23 536 AI bekannt. Für jeden Brennraum der Brennkraftmaschine ist eine Pumpe-Düse-Einheit vorgesehen, bei der eine Pumpeneinheit, ein Steuerventil und ein Einspritzventil in einer Einheit integriert ist. Die Pumpeneinheit besteht aus einem Pumpenkolben, der synchron mit der Brennkraftmaschine angetrieben wird und in einen Pumpenarbeitsraum eintaucht, wo er den darin befindlichen Kraftstoff unter hohem Druck verdrängt. Der Pumpenarbeits- raum ist mit dem Kraftstoffeinspritzventil verbunden, das bei einem bestimmten Kraftstoffdruck öffnet und so Kraftstoff unter hohem Druck in den Brennraum der Brennkraftmaschine einspritzt.The invention is based on a fuel injection device for an internal combustion engine. Such a fuel injection device in the form of a pump-nozzle unit is known from the published patent application DE 35 23 536 AI. A pump-nozzle unit is provided for each combustion chamber of the internal combustion engine, in which a pump unit, a control valve and an injection valve are integrated in one unit. The pump unit consists of a pump piston that is driven synchronously with the internal combustion engine and immersed in a pump work space, where it displaces the fuel therein under high pressure. The pump work space is connected to the fuel injection valve, which opens at a certain fuel pressure and thus injects fuel under high pressure into the combustion chamber of the internal combustion engine.
Das im Gehäuse der Pumpe-Düse-Einheit angeordnete Steuerventil öffnet und schließt eine Verbindung des Pumpenarbeits- raums mit einem Kraftstoffzufuhrsystem, in dem ein niedriger Kraftstoffdruck herrscht und das sowohl Kraftstoff der Pumpe-Düse-Einheit zuführt als auch überschüssigen Kraftstoff aufnimmt. Ist das Steuerventil geöffnet, wird der Kraftstoff aus dem Pumpenarbeitsraum in das Kraftstoffzufuhrsystem geleitet, so daß sich kein Kraftstoffdruck im Einspritzventil aufbauen kann und es somit zu keiner Einspritzung kommt. Schließt das Steuerventil, so kann sich ein entsprechender Druck aufbauen und Kraftstoff wird in den Brennraum der Brennkraftmaschine eingespritzt. Auf diese Weise läßt sich der Beginn der Einspritzung und über deren Dauer auch die eingespritzte Kraftstoffmenge steuern. Das Ventilglied wird durch eine Feder in Öffnungsrichtung beaufschlagt und durch eine steuerbare Gegenkraft, die hier durch einen Elektromagneten aufgebracht wird, in Schließstellung gehalten. Wird der Elektromagnet abgeschaltet, so drückt die Feder das Ventilglied in Öffnungsrichtung und die Verbindung vom Hochdruck- in den Niederdruckbereich wird geöffnet .The control valve arranged in the housing of the pump-injector unit opens and closes a connection between the pump work chamber and a fuel supply system in which the fuel pressure is low and which both supplies fuel to the pump-injector unit and absorbs excess fuel. If the control valve is open, the fuel is led from the pump work space into the fuel supply system, so that no fuel pressure can build up in the injection valve and thus there is no injection. If the control valve closes, a corresponding pressure can build up and fuel is injected into the combustion chamber of the internal combustion engine. In this way, the start of the injection and the duration of the injected fuel quantity can be controlled. The valve member is acted upon by a spring in the opening direction and held in the closed position by a controllable counterforce, which is applied here by an electromagnet. If the electromagnet is switched off, the spring pushes the valve member in the opening direction and the connection from the high pressure to the low pressure area is opened.
Das Ventilglied des Steuerventils weist bei einem in DE 35 23 536 AI gezeigten Ausführungsbeispiel einen Ventilsitz und einen in Strömungsrichtung vom Hochdruckbereich in den Niederdruckbereich gesehen stromabwärts gelegenen Bereich einen Drosselbund am Ventilglied auf, durch den der Durchflußquerschnitt in einem gewissen Bereich weitgehend unabhängig vom Hub des Ventilglieds ist. Dadurch kann ein gedrosselter Kraftstofffluß vom Hochdruckraum in den Niederdruckraum eingestellt werden.The valve member of the control valve has in one embodiment shown in DE 35 23 536 AI a valve seat and a downstream in the flow direction from the high pressure area to the low pressure area a throttle collar on the valve member, through which the flow cross section in a certain range largely independent of the stroke of the valve member is. As a result, a throttled fuel flow from the high-pressure space into the low-pressure space can be set.
Dabei weist das bekannte Ventilglied jedoch den Nachteil auf, das beim Öffnen des Ventilglieds auf die Ventildichtfläche eine hydraulische Kraft wirkt, die sich im Laufe der Offnungshubbewegung des Ventilglieds zur Öffnungskraft der Feder hinzu addiert. Dadurch ist es schwer, die Gegenkraft des Elektromagneten entsprechend den Erfordernissen so zu regeln, daß das Ventilglied in einer Stellung gehalten wird, in der der Durchfluß von Kraftstoff gedrosselt wird.However, the known valve member has the disadvantage that when the valve member opens, a hydraulic force acts on the valve sealing surface, which is added to the opening force of the spring in the course of the opening stroke movement of the valve member. As a result, it is difficult to control the counter force of the electromagnet according to the requirements so that the valve member is held in a position in which the flow of fuel is throttled.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Pumpe-Düse-Einheit mit den kennzeichnenden Merkmalen des Patentanspruchs 1 weist demgegenüber den Vorteil auf, daß auf das Ventilglied in der Drosselstellung keine zusätzlichen hydraulischen Kräfte wirken, die vom Öffnungsmechanismus ausgeglichen werden müssen. Das Ventilglied weist einen relativ großen Hubbereich auf, in dem der Durchflußquerschnitt unabhängig vom Hub ist. Der Drosselspalt ist zwischen einem zylindrischen Abschnitt der Bohrung und dem Ventilglied gebildet und liegt in Flußrichtung des Kraftstoffs vom Hochdruckraum zum Niederdruckraum gesehen flußaufwärts zum Ventilsitz. Der Kraftstoffström wird aus dem Hochdruckraum erst durch diesen Drosselspalt und dann an der Ventildichtfläche vorbei zum Niederdruckraum geleitet, so daß an der Ventildichtfläche bereits ein niedriger Kraftstoffdruck herrscht. Dadurch wirken keine oder nur unwesentliche hydraulische Kräfte auf die Ventildichtfläche, die sich der öffnenden Kraft auf das Ventilglied überlagern. Das Ventilglied kann so neben einer geöffneten und einer geschlossenen Position auch eine dritte, drosselnde Position leicht beherrschbar anfahren, so daß eine Voreinspritzung mit niedrigerem Druck durch das Einspritzventil möglich wird.The pump-nozzle unit according to the invention with the characterizing features of claim 1, however, points out the advantage that no additional hydraulic forces act on the valve member in the throttle position, which have to be compensated for by the opening mechanism. The valve member has a relatively large stroke range in which the flow cross-section is independent of the stroke. The throttle gap is formed between a cylindrical section of the bore and the valve member and, viewed in the direction of flow of the fuel from the high-pressure chamber to the low-pressure chamber, lies upstream of the valve seat. The fuel flow from the high-pressure chamber is first passed through this throttle gap and then past the valve sealing surface to the low-pressure chamber, so that there is already a low fuel pressure at the valve sealing surface. As a result, no or only insignificant hydraulic forces act on the valve sealing surface, which are superimposed on the opening force on the valve member. In addition to an open and a closed position, the valve member can also move to a third, throttling position in an easily controllable manner, so that a pre-injection with lower pressure is possible through the injection valve.
Zeichnungdrawing
In der Zeichnung ist ein Ausführungsbeispiel der erfindungs- gemäßen Kraftstoffeinspritzvorrichtung dargestellt. Es zeigt Figur 1 einen Längsschnitt durch eine Kraftstoffein- spritzvorrichtung,An exemplary embodiment of the fuel injection device according to the invention is shown in the drawing. 1 shows a longitudinal section through a fuel injection device,
Figur 2 eine Vergrößerung der Figur 1 im Bereich eines Steuerventils undFigure 2 is an enlargement of Figure 1 in the area of a control valve and
Figur 3 eine schematische Darstellung des vom Steuerventil aufgesteuerten Durchflußquerschnitts als Funktion des Hubs des Ventilglieds. Beschreibung des AusführungsbeispielsFigure 3 is a schematic representation of the flow cross-section controlled by the control valve as a function of the stroke of the valve member. Description of the embodiment
In Figur 1 ist ein Längsschnitt durch eine erfindungsgemäße Kraftstoffeinspritzvorrichtung in Form einer Pumpe-Düse- Einheit gezeigt, wie sie zur Einspritzung von Kraftstoff in den Brennraum einer Brennkraftmaschine, insbesondere einer selbstzündenden Brennkraftmaschine, verwendet wird. Die Pumpe-Düse-Einheit beinhaltet alle für eine Einspritzung notwendigen Komponenten, das ist eine hochdruckerzeugende Pumpeneinheit 39, ein Einspritzventil 1 und ein Steuerventil 11, das den Beginn und das Ende der Einspritzung steuert. Zur Verdeutlichung ist in Figur 2 eine Vergrößerung der Figur 1 im Bereich des Steuerventils 11 gezeigt. Im folgenden wird zunächst der Aufbau der einzelnen Komponenten erläutert und anschließend ihre Funktion als Teil der Pumpe-Düse- Einheit dargelegt .FIG. 1 shows a longitudinal section through a fuel injection device according to the invention in the form of a pump-nozzle unit, as is used for injecting fuel into the combustion chamber of an internal combustion engine, in particular a self-igniting internal combustion engine. The pump-nozzle unit contains all components necessary for an injection, that is a high-pressure generating pump unit 39, an injection valve 1 and a control valve 11 which controls the start and the end of the injection. For clarification, FIG. 2 shows an enlargement of FIG. 1 in the area of the control valve 11. In the following, the structure of the individual components is first explained and then their function as part of the pump-nozzle unit is explained.
Das Einspritzventil 1 umfaßt einen Einspritzventilkörper 2, der im wesentlichen als ein im Durchmesser gestufter Zylinder ausgebildet ist und mit einem Ende bis in den Brennraum einer in der Zeichnung nicht dargestellten Brennkraftmaschine ragt. Im Einspritzventilkörper 2 ist eine Sackbohrung 9 ausgebildet, deren geschlossenes Ende dem Brennraum zugewandt ist und an welchem Ende wenigstens eine Einspritzöffnung 7 ausgebildet ist, die die Sackbohrung 9 mit dem Brennraum der Brennkraftmaschine verbindet . In der Sackbohrung 9 ist eine Ventilnadel 3 angeordnet, die entgegen der Kraft einer Schließfeder 5 längsverschiebbar ist und die durch ihre Offnungshubbewegung die wenigstens eine Einspritzöffnung 7 auf- und zusteuert. Die Ventilnadel 3 ist von einem im Einspritzventilkörper 2 ausgebildeten Druckraum 8 umgeben, der sich als ein die Ventilnadel 3 umgebender Ringkanal bis zu den Einspritzöffnungen 7 fortsetzt und sich über einen im Einspritzventilkörper 2 ausgebildeten Hochdruckkanal 10 mit Kraftstoff unter hohem Druck befüllen läßt. Brennraumabgewandt zum Einspritzventilkörper 2 ist ein zy- linderförmiger Ventilkörper 12 angeordnet, der am Einspritz- ventilkδrper 2 mit einer Stirnseite anliegt und dessen andere, brennraumabgewandte Stirnseite an einem Pumpenkörper 40 zur Anlage kommt, wobei Einspritzventilkörper 2, Ventilkörper 12 und Pumpenkörper 40 durch eine in der Zeichnung nicht dargestellte Vorrichtung in axialer Richtung gegeneinander verspannt sind. Der im Einspritzventilkörper 2 ausgebildete Hochdruckkanal 10 setzt sich in axialer Richtung durch den gesamten Ventilkörper 12 bis in den Pumpenkörper 40 fort. Im Ventilkörper 12 ist als Teil des Steuerventils 11 in axialer Richtung eine Bohrung 26 ausgebildet, die sich in einen im Durchmesser größeren Dichtungsabschnitt 126 und einen im Durchmesser kleineren und zum Brennraum hin verschlossenen Führungsabschnitt 226 unterteilt, wobei am Übergang der beiden Abschnitte 126, 226 eine als Ventilsitz 22 dienende Ringschulter ausgebildet ist. In der Bohrung 26 ist ein Ventilglied 14 angeordnet, das im Dichtungsabschnitt 126 der Bohrung 26 dichtend geführt ist und das sich unter Bildung einer Ventildichtfläche 24 zum Brennraum hin verjüngt und bis in den Führungsabschnitt 226 der Bohrung 26 ragt. Zum brennraumseitigen Ende des Ventilglieds 14 hin vergrößert es sich im Durchmesser erneut und geht in einen Abschnitt 214 über, der im Führungsabschnitt 226 der Bohrung 26 geführt ist. Zwischen dem Ventilglied 14 und dem brennraumseitigen Ende der Bohrung 26 ist eine Feder 27 unter Vorspannung angeordnet, die das Ventilglied 14 vom Brennraum weg beaufschlagt .The injection valve 1 comprises an injection valve body 2, which is essentially designed as a cylinder with a stepped diameter and projects with one end into the combustion chamber of an internal combustion engine, not shown in the drawing. In the injection valve body 2, a blind bore 9 is formed, the closed end of which faces the combustion chamber and at which end at least one injection opening 7 is formed which connects the blind bore 9 to the combustion chamber of the internal combustion engine. A valve needle 3 is arranged in the blind bore 9, which is longitudinally displaceable against the force of a closing spring 5 and which opens and closes the at least one injection opening 7 through its opening stroke movement. The valve needle 3 is surrounded by a pressure chamber 8 formed in the injection valve body 2, which continues as an annular channel surrounding the valve needle 3 up to the injection openings 7 and can be filled with fuel under high pressure via a high pressure channel 10 formed in the injection valve body 2. A cylinder-shaped valve body 12 is arranged facing away from the combustion chamber and has an end face on the injection valve body 2 and the other end facing away from the combustion chamber comes into contact with a pump body 40, the injection valve body 2, valve body 12 and pump body 40 being connected by a valve Drawing, not shown, are braced against each other in the axial direction. The high-pressure channel 10 formed in the injection valve body 2 continues in the axial direction through the entire valve body 12 into the pump body 40. A bore 26 is formed in the valve body 12 as part of the control valve 11 in the axial direction, which is divided into a larger-diameter sealing section 126 and a smaller-diameter guide section 226, which is closed toward the combustion chamber, one at the transition between the two sections 126, 226 is designed as a valve seat 22 serving as an annular shoulder. A valve member 14 is arranged in the bore 26, which is sealingly guided in the sealing section 126 of the bore 26 and which tapers towards the combustion chamber to form a valve sealing surface 24 and projects into the guide section 226 of the bore 26. Towards the end of the valve member 14 on the combustion chamber side, it increases in diameter again and merges into a section 214 which is guided in the guide section 226 of the bore 26. Between the valve member 14 and the combustion chamber end of the bore 26, a spring 27 is arranged under prestress, which acts on the valve member 14 away from the combustion chamber.
Den dichtend geführten Abschnitt 114 des Ventilglieds 14 umgibt ein im Ventilkörper 12 ausgebildeter Hochdruckraum 16, der über eine Verbindungsbohrung 20 mit dem Hochdruckkanal 10 verbunden ist. Das Steuerventil 11 öffnet und schließt die Verbindung zu einem Niederdruckraum 18, der durch die zwischen den Abschnitten 114 und 214 des Ventilglieds 14 gebildete Verjüngung des Ventilglieds 14 und dem Führungsab- schnitt 226 der Bohrung 26 gebildet ist. Der Niederdruckraum 18 ist über einen Zulaufkanal 29 mit einem Kraftstoffzufuhrsystem 58 verbunden. Das Kraftstoffzufuhrsystem 58 umfaßt einen Tank 66 , aus dem über eine Niederdruckleitung 60 Kraftstoff mittels einer Förderpumpe 62 in den Niederdruckraum 18 gefördert wird. Parallel zur Förderpumpe 62 ist ein Überdruckventil 64 angeordnet, das dafür sorgt, daß Kraftstoff aus dem Niederdruckraum 18 bei übersteigen eines bestimmten Schwelldrucks zurück in den Tank 66 fließen kann.The sealingly guided section 114 of the valve member 14 is surrounded by a high-pressure space 16 formed in the valve body 12, which is connected to the high-pressure channel 10 via a connecting bore 20. The control valve 11 opens and closes the connection to a low-pressure chamber 18, which is formed by the tapering of the valve member 14 and the guide branch formed between the sections 114 and 214 of the valve member 14. section 226 of the bore 26 is formed. The low pressure chamber 18 is connected to a fuel supply system 58 via an inlet channel 29. The fuel supply system 58 comprises a tank 66, from which fuel is conveyed into the low-pressure chamber 18 via a low-pressure line 60 by means of a feed pump 62. A pressure relief valve 64 is arranged parallel to the feed pump 62 and ensures that fuel can flow back into the tank 66 from the low pressure space 18 when a certain threshold pressure is exceeded.
Die brennraumabgewandte Stirnfläche 28 des Ventilglieds 14 ragt bis in einen in einem Pumpenkörper 40 ausgebildeten Steuerraum 30, der mit Kraftstoff gefüllt ist. Über den Kraftstoffdruck im Steuerraum 30 läßt sich eine hydraulische Kraft auf die Stirnfläche 28 des Ventilglieds 14 aufbringen, die der Kraft der Feder 27 entgegen gerichtet ist, so daß sich das Ventilglied 14 in der Bohrung 26 gesteuert durch den Kraftstoffdruck im Steuerraum 30 in Längsrichtung bewegen läßt .The end face 28 of the valve member 14 facing away from the combustion chamber extends into a control chamber 30 which is formed in a pump body 40 and is filled with fuel. Via the fuel pressure in the control chamber 30, a hydraulic force can be applied to the end face 28 of the valve member 14, which is directed counter to the force of the spring 27, so that the valve member 14 in the bore 26 moves in the longitudinal direction controlled by the fuel pressure in the control chamber 30 leaves .
Der Steuerraum 30 ist über eine Verbindungsbohrung 33 mit einem Federraum 38 verbunden, welcher Federraum 38 durch das geschlossene Ende einer Führungsbohrung 37 und die Stirnfläche eines in der Führungsbohrung 37 dichtend längsverschiebbar geführten Steuerkolbens 32 begrenzt wird. Der Steuerkol- ben 32 wird von einer im Federraum 38 unter Vorspannung angeordneten Rückstellfeder 36 beaufschlagt und ist an seiner dem Federraum 38 abgewandten Stirnfläche mit einem Piezoak- tor 34 verbunden, der durch eine geeignete Bestromung seine Ausdehnung ändern und so den Steuerkolben 32 in der Führungsbohrung 37 bewegen kann. Der Steuerkolben 32 verdrängt bei seiner Längsbewegung Kraftstoff aus dem Federraum 38 und preßt den Kraftstoff über die Verbindungsbohrung 33 in den Steuerraum 30, so daß sich dort entsprechend der Druck und damit auch die hydraulische Kraft auf die Stirnfläche 28 des Ventilglieds 14 ändert . Zwischen dem Ventilsitz 22 und dem Hochdruckraum 16 ist ein Drosselabschnitt 21 in der Bohrung 26 ausgebildet, der gegenüber dem Dichtungsabschnitt 126 der Bohrung 26 einen noch etwas vergrößerten Durchmesser aufweist. Dadurch ist zwischen dem Drosselabschnitt 21 der Bohrung 26 und der Mantelfläche des Ventilglieds 14 ein enger, als Ringspalt ausgebildeter Drosselspalt 23 gebildet. Zur Steuerung des Kraftstoffflusses vom Hochdruckraum 16 zum Niederdruckraum 18 ergibt sich somit neben der geschlossenen und geöffneten Stellung des Ventilglieds 14 eine weitere: Wenn sich die am Übergang vom dichtenden Abschnitt 114 zur Ventildichtfläche 24 gebildete Steuerkante 25 innerhalb des Drosselabschnitts 21 der Bohrung 26 befindet, findet der Kraftstoffström vom Hochdruckraum 16 zum Niederdruckraum 18 gedrosselt statt. Taucht die Steuerkante 25 im Verlauf der Offnungshubbewegung des Ventilglieds 14 aus dem Drosselabschnitt 21 aus, so ergibt sich ein freier Fluß von Kraftstoff aus dem Hochdruckraum 16 in den Niederdruckraum 18.The control chamber 30 is connected via a connecting bore 33 to a spring chamber 38, which spring chamber 38 is delimited by the closed end of a guide bore 37 and the end face of a control piston 32, which is sealingly longitudinally displaceable in the guide bore 37. The control piston 32 is acted upon by a return spring 36 arranged under prestress in the spring chamber 38 and is connected on its end face facing away from the spring chamber 38 to a piezo actuator 34, which changes its extension by means of a suitable energization and thus the control piston 32 in the guide bore 37 can move. The control piston 32 displaces fuel from the spring chamber 38 during its longitudinal movement and presses the fuel through the connecting bore 33 into the control chamber 30, so that there the pressure and thus also the hydraulic force on the end face 28 of the valve member 14 changes accordingly. Between the valve seat 22 and the high-pressure chamber 16, a throttle section 21 is formed in the bore 26, which has a somewhat larger diameter than the sealing section 126 of the bore 26. As a result, a narrow throttle gap 23 designed as an annular gap is formed between the throttle section 21 of the bore 26 and the outer surface of the valve member 14. To control the fuel flow from the high-pressure chamber 16 to the low-pressure chamber 18, there is another in addition to the closed and open position of the valve member 14: If the control edge 25 formed at the transition from the sealing section 114 to the valve sealing surface 24 is located within the throttle section 21 of the bore 26 the fuel flow from the high-pressure chamber 16 to the low-pressure chamber 18 is throttled instead. If the control edge 25 emerges from the throttle section 21 in the course of the opening stroke movement of the valve member 14, then there is a free flow of fuel from the high-pressure chamber 16 into the low-pressure chamber 18.
Trägt man den durch das Ventilglied 14 freigegebenen Durchflußquerschnitt A gegen den Hub h des Ventilglieds 14 auf, so ergibt sich schematisch das in Figur 3 dargestellte Diagramm, wobei der Hub h bei Anlage der Ventildichtfläche 24 am Ventilsitz 22 null sein soll. Zu Beginn der Offnungshubbewegung weist der sich zwischen Ventildichtfläche 24 und Ventilsitz 22 bildende Steuerspalt 31 einen kleineren Durchflußquerschnitt auf als der Drosselspalt 23. Der aufgesteuerte Durchflußquerschnitt A steigt somit mit dem Hub h an, bis der Durchflußquerschnitt des Steuerspalts 31 den des Drosselspalts 23 erreicht. Ab diesem Punkt steigt die Größe des Durchflußquerschnitts A mit zunehmendem Hub h nur noch leicht an, da der Durchflußquerschnitt A durch den Drosselspalt 23 bestimmt wird und somit der nachfolgende Steuerspalt 31 für den Durchflußquerschnitt des Kraftstoffs und damit auch für den Durchflußwiderstand keine große Rolle M et to rr CQ , H td ö 0 H ≤ Pi rr t CQ >d H ι-i pr Pi Pi μ- tr < μ, PJ α Pi CO ωIf the flow cross-section A released by the valve member 14 is plotted against the stroke h of the valve member 14, the diagram shown in FIG. 3 is obtained schematically, the stroke h being intended to be zero when the valve sealing surface 24 bears against the valve seat 22. At the beginning of the opening stroke movement, the control gap 31 which forms between the valve sealing surface 24 and the valve seat 22 has a smaller flow cross section than the throttle gap 23. The flow cross section A thus increases with the stroke h until the flow cross section of the control gap 31 reaches that of the throttle gap 23. From this point, the size of the flow cross section A increases only slightly with increasing stroke h, since the flow cross section A is determined by the throttle gap 23 and thus the subsequent control gap 31 for the flow cross section of the fuel and thus also for the flow resistance does not play a major role M et to rr CQ, H td ö 0 H ≤ Pi rr t CQ> d H ι-i pr Pi Pi μ- tr <μ, PJ α Pi CO ω
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1 1
druckkanal 10 herrscht der von der Förderpumpe 62 erzeugte, niedrige Kraftstoffdruck. Der Pumpenkolben 42 befindet sich in seinem oberen Umkehrpunkt, so daß der Pumpenarbeitsraum 48 sein maximales Volumen aufweist.pressure channel 10, the low fuel pressure generated by the feed pump 62 prevails. The pump piston 42 is in its upper reversal point, so that the pump working space 48 has its maximum volume.
Durch einen in der Zeichnung nicht dargestellten Mechanismus wird der Pumpenkolben 42 in den Pumpenarbeitsraum 48 bewegt, so daß er den im Pumpenarbeitsraum 48 befindlichen Kraftstoff komprimiert und in den Hochdruckkanal 10 verdrängt. Kurz nach Beginn dieses Förderhubs des Pumpenkolbens 42 wird der Piezoaktor 34 bestromt, so daß er seine Länge ändert und den Steuerkolben 32 entgegen der Kraft der Rückstellfeder 36 in den Federraum 38 bewegt. Der dadurch aus dem Federraum 38 verdrängte Kraftstoff erhöht den Kraftstoffdruck im Steuerraum 30, so daß sich die Kraft auf die Stirnfläche 28 des Ventilglieds 14 ebenfalls entsprechend soweit erhöht, daß sie größer wird als die Kraft der Feder 27. Die Bestromung des Piezoaktors 34 wird dabei so geregelt, daß die Steuerkante 25 in den Drosselabschnitt 21 eintaucht, ohne daß die Ventildichtfläche 24 am Ventilsitz 22 zur Anlage kommt. Der Kraftstoff, der zu Beginn der Förderbewegung des Pumpenkolbens 42 praktisch ungedrosselt aus dem Hochdruckkanal 10 über den Hochdruckraum 16 in den Niederdruckraum 18 abfließen kann, wird nun durch den Drosselspalt 23 gedrosselt, so daß sich im Hochdruckraum 16 und im Hochdruckkanal 10 ein gewisser Voreinspritzdruck einstellt, der davon abhängt, wie groß die Förderrate des Pumpenkolbens 42 und wie stark die drosselnde Wirkung des Drosselspalts 23 ist. Die Drosselung des Kraftstoffdrucks erfolgt dabei im Drosselspalt 23, so daß der Druck im Kraftstoffström zum Niederdruckraum 18 bereits abgefallen ist, wenn der Kraftstoff die Ventildichtfläche 24 erreicht . Deshalb ergeben sich nur geringe hydraulische Kräfte auf die Ventildichtfläche 24 und damit auch keine schlecht zu kontrollierenden Kräfte in Öffnungsrichtung auf das Ventilglied 14. Diese zusätzlichen Kräfte müßten vom Druck im Steuerraum 30 ausgeglichen werden, was die Zuverlässigkeit des Steuerventils deutlich beeinträchtigen würde . Da so als Öffnungskraft im wesentlichen nur die Kraft der Feder 27 wirkt, kann mit hoher Genauigkeit über den Druck im Steuerraum 30 die Drosselstellung des Ventilglieds 14 angefahren werden.The pump piston 42 is moved into the pump work chamber 48 by a mechanism, not shown in the drawing, so that it compresses the fuel located in the pump work chamber 48 and displaces it into the high-pressure channel 10. Shortly after the start of this delivery stroke of the pump piston 42, the piezo actuator 34 is energized so that it changes its length and moves the control piston 32 against the force of the return spring 36 into the spring chamber 38. The fuel thus displaced from the spring chamber 38 increases the fuel pressure in the control chamber 30, so that the force on the end face 28 of the valve member 14 also increases accordingly to such an extent that it becomes greater than the force of the spring 27 regulated so that the control edge 25 dips into the throttle section 21 without the valve sealing surface 24 coming into contact with the valve seat 22. The fuel, which can flow practically unthrottled from the high-pressure duct 10 via the high-pressure chamber 16 into the low-pressure chamber 18 at the start of the delivery movement of the pump piston 42, is now throttled through the throttle gap 23, so that a certain pre-injection pressure is established in the high-pressure chamber 16 and in the high-pressure duct 10 , which depends on how large the delivery rate of the pump piston 42 and how strong the throttling effect of the throttle gap 23. The throttling of the fuel pressure takes place in the throttle gap 23, so that the pressure in the fuel flow to the low pressure chamber 18 has already dropped when the fuel reaches the valve sealing surface 24. Therefore, there are only slight hydraulic forces on the valve sealing surface 24 and therefore also no forces that are difficult to control in the opening direction on the valve member 14. These additional forces would have to be compensated for by the pressure in the control chamber 30, which Reliability of the control valve would significantly affect. Since essentially only the force of the spring 27 acts as the opening force, the throttle position of the valve member 14 can be approached with high accuracy via the pressure in the control chamber 30.
Der Voreinspritzdruck im Hochdruckkanal 10 und damit auch im Druckraum 8 des Einspritzventils 1 ist mit der Kraft der Schließfeder 5, die die Ventilnadel 3 in der Schließstellung hält, so abgestimmt, daß die hydraulische Kraft auf die Ventilnadel 3 ausreicht, die Ventilnadel 3 in Öffnungsstellung zu bewegen und so die Einspritzöffnungen 7 freizugeben. Da der Voreinspritzdruck deutlich unter dem maximalen Ξin- spritzdruck liegt, wird nur eine geringe Kraftstoffmenge in den Brennraum eingespritzt (Voreinspritzung) . Zur Haupteinspritzung erhöht der Steuerkolben 32 durch den Piezoaktor 34 den Druck im Steuerraum 30 weiter, bis das Ventilglied 14 durch die hydraulische Kraft auf die Stirnfläche 28 mit der Ventildichtfläche 24 am Ventilsitz 22 zur Anlage kommt. Dadurch wird die Verbindung des Hochdruckraums 16 zum Niederdruckraum 18 unterbrochen, und der maximale, vom Pumpenkolben 42 erzeugbare Druck wirkt im Hochdruckkanal 10 und im Druckraum 8. Die Einspritzung erfolgt jetzt mit einem deutlich höheren Einspritzdruck und damit mit einer höheren Einspritzrate .The pre-injection pressure in the high-pressure channel 10 and thus also in the pressure chamber 8 of the injection valve 1 is matched to the force of the closing spring 5, which holds the valve needle 3 in the closed position, so that the hydraulic force on the valve needle 3 is sufficient to close the valve needle 3 in the open position move and so open the injection openings 7. Since the pre-injection pressure is clearly below the maximum injection pressure, only a small amount of fuel is injected into the combustion chamber (pre-injection). For the main injection, the control piston 32 further increases the pressure in the control chamber 30 through the piezo actuator 34 until the valve member 14 comes into contact with the valve sealing surface 24 on the valve seat 22 due to the hydraulic force on the end face 28. As a result, the connection of the high-pressure chamber 16 to the low-pressure chamber 18 is interrupted, and the maximum pressure that can be generated by the pump piston 42 acts in the high-pressure channel 10 and in the pressure chamber 8. The injection is now carried out with a significantly higher injection pressure and thus with a higher injection rate.
Die Haupteinspritzung kann längstens solange fortgesetzt werden, bis der Pumpenkolben 42 seinen unteren Umkehrpunkt erreicht hat und der gesamte, durch den Pumpenkolben 42 verdrängbare Kraftstoff in den Hochdruckkanal 10 gefördert ist. Meist wird die Haupteinspritzung jedoch deutlich vorher beendet, da zum einen weniger Kraftstoff im Brennraum benötigt wird und zum anderen ein genau definiertes Ende der Einspritzung angestrebt wird. Dies geschieht dadurch, daß gesteuert durch den Piezoaktor 34 der Druck im Steuerraum 30 reduziert wird. Die Kraft der Feder 27 überwiegt jetzt wie- der gegenüber der hydraulischen Kraft auf die Stirnfläche 28 des Ventilglieds 14, und das Ventilglied 14 wird in Richtung auf den Steuerraum 30 bewegt, bis es an der Wand des Steuerraums 30 zur Anlage kommt. Dadurch wird auch der Hochdruckkanal 10 über den Hochdruckraum 16 mit dem Niederdruckraum 18 verbunden, so daß auch der Druck im Druckraum 8 abfällt und die Ventilnadel 3 durch die Schließfeder 5 die Ein- spritzöffnungen 7 verschließt. Die Restmenge an Kraftstoff, die der Pumpenkolben 42 nach Beendigung der Einspritzung noch fördert, ehe er den unteren Umkehrpunkt erreicht, wird in die Niederdruckleitung 60 gefördert und von dort über das Überdruckventil 64 in den Tank 66.The main injection can be continued at the longest until the pump piston 42 has reached its lower reversal point and all the fuel that can be displaced by the pump piston 42 is conveyed into the high-pressure channel 10. Most of the time, however, the main injection is terminated much earlier, since less fuel is required in the combustion chamber and secondly a precisely defined end of the injection is aimed for. This is done in that the pressure in the control chamber 30 is reduced, controlled by the piezo actuator 34. The force of the spring 27 now predominates. the opposite of the hydraulic force on the end face 28 of the valve member 14, and the valve member 14 is moved in the direction of the control chamber 30 until it comes to rest on the wall of the control chamber 30. As a result, the high-pressure channel 10 is also connected to the low-pressure chamber 18 via the high-pressure chamber 16, so that the pressure in the pressure chamber 8 also drops and the valve needle 3 closes the injection openings 7 by the closing spring 5. The remaining amount of fuel that the pump piston 42 delivers after the end of the injection before it reaches the lower reversal point is delivered into the low-pressure line 60 and from there via the pressure relief valve 64 into the tank 66.
Bei der anschließenden Hubförderbewegung des Pumpenkolbens 42 aus seinem unteren zum oberen Umkehrpunkt wird durch die Förderpumpe 62 Kraftstoff durch die Niederdruckleitung 60 und den Zulaufkanal 29 in den Niederdruckraum 18 gepumpt, von wo der Kraftstoff über den Hochdruckraum 16, die Verbindungsbohrung 20 und den Hochdruckkanal 10 in den Pumpenarbeitsraum 48 gelangt. Erreicht der Pumpenkolben 42 schließlich den oberen Umkehrpunkt, ist der Einspritzzyklus abgeschlossen.During the subsequent stroke-conveying movement of the pump piston 42 from its lower to the upper reversal point, fuel is pumped by the feed pump 62 through the low-pressure line 60 and the inlet channel 29 into the low-pressure chamber 18, from where the fuel via the high-pressure chamber 16, the connecting bore 20 and the high-pressure channel 10 in the pump workspace 48 arrives. When the pump piston 42 finally reaches the upper reversal point, the injection cycle is completed.
Die in der Zeichnung dargestellte Anordnung des Ventilglieds 14, des Steuerkolbens 32 und des Pumpenkolbens 44 bezüglich des Einspritzventils 1 ist für die Funktion der Pumpe-Düse- Einheit nicht in dieser Weise erforderlich. Es kann auch vorgesehen sein, eines oder mehrere dieser Elemente - wenn es zweckdienlich sein sollte - in anderer Weise zu orientieren. Beispielsweise kann das Ventilglied 14 und damit die Bohrung 26 auch senkrecht zur Längsachse der Düsennadel 3 angeordnet sein.The arrangement of the valve member 14, the control piston 32 and the pump piston 44 with respect to the injection valve 1 shown in the drawing is not required in this way for the function of the pump-nozzle unit. Provision can also be made for orienting one or more of these elements in a different way, if it should be expedient. For example, the valve member 14 and thus the bore 26 can also be arranged perpendicular to the longitudinal axis of the nozzle needle 3.
Neben der in der Zeichnung dargestellten hydraulischen Steuerung der Schließkraft auf das Ventilglied 14 mittels eines Piezoaktors ist es auch möglich, die Schließkraft bei- spielsweise durch einen Elektromagneten auszuüben. Auch muß die Kraft des Piezoaktors 34 nicht über eine hydraulische Umsetzung aufgebracht werden, sondern kann auch direkt auf das Ventilglied 14 wirken. In addition to the hydraulic control of the closing force on the valve member 14 by means of a piezo actuator shown in the drawing, it is also possible to for example by an electromagnet. The force of the piezo actuator 34 does not have to be applied via a hydraulic conversion, but can also act directly on the valve member 14.

Claims

Ansprüche Expectations
1. Kraftstoffeinspritzvorrichtung für eine Brennkraftmaschine mit einer Pumpeneinheit (39) , die durch Verdrängung des Kraftstoffs aus einem Pumpenarbeitsraum (48) Kraftstoff unter hohem Druck fördert, und mit einem Hochdruckkanal (10) , über den der Pumpenarbeitsraum (48) mit einem Einspritzventil (1) verbunden ist, mit einem Steuerventil1. Fuel injection device for an internal combustion engine with a pump unit (39), which delivers fuel under high pressure by displacing the fuel from a pump work space (48), and with a high-pressure channel (10), via which the pump work space (48) with an injection valve (1 ) is connected to a control valve
(11) , welches ein Ventilglied (14) aufweist, das mit einem zylinderförmigen, dichtenden Abschnitt (114) in einer Bohrung (26) längsverschiebbar geführt ist, wobei der dichtende Abschnitt (114) von einem Hochdruckraum (16) umgeben ist, der mit dem Pumpenarbeitsraum (48) verbunden ist, welches Ventilglied (14) mit einem Ende in einen Niederdruckraum (18) ragt, der mit einem Kraftstoffzufuhrsystem verbunden ist, wobei zwischen dem Hochdruckraum (16) und dem Niederdruckraum (18) in der Bohrung (26) ein Ventilsitz (22) ausgebildet ist, der mit einer am Ventilglied (14) ausgebildeten Ventildichtfläche (24) zur Steuerung der Verbindung vom Hochdruckraum (16) zum Niederdruckraum (18) zusammenwirkt, wobei die Schließbewegung des Ventilglieds (14) bezüglich der Flußrichtung des Kraftstoffs vom Hochdruckraum (16) zum Niederdruckraum (18) in Flußrichtung erfolgt, dadurch gekennzeichnet, daß flußaufwärts zum Ventilsitz (22) in der Bohrung (26) ein Drosselabschnitt (21) ausgebildet ist, so daß zwischen dem Drosselabschnitt (21) und der Mantelfläche des Ventilglieds (14) ein Drosselspalt (23) gebildet ist.(11), which has a valve member (14) which is guided with a cylindrical, sealing section (114) in a bore (26) in a longitudinally displaceable manner, the sealing section (114) being surrounded by a high-pressure chamber (16) which is connected to is connected to the pump work chamber (48), one end of the valve member (14) projects into a low pressure chamber (18) which is connected to a fuel supply system, the high pressure chamber (16) and the low pressure chamber (18) in the bore (26) a valve seat (22) is formed which cooperates with a valve sealing surface (24) formed on the valve member (14) for controlling the connection from the high pressure chamber (16) to the low pressure chamber (18), the closing movement of the valve member (14) with respect to the flow direction of the fuel from the high-pressure chamber (16) to the low-pressure chamber (18) in the flow direction, characterized in that a throttle section (21) is formed upstream of the valve seat (22) in the bore (26), so that a throttle gap (23) is formed between the throttle section (21) and the outer surface of the valve member (14).
2. Kraftstoffeinspritzvorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß sich der Drosselabschnitt (21) der Bohrung (26) vom Ventilsitz (22) flußaufwärts bis in den Hochdruckraum (16) erstreckt.2. Fuel injection device according to claim 1, characterized in that the throttle section (21) Bore (26) extends from the valve seat (22) upstream into the high-pressure chamber (16).
3. Kraftstoffeinspritzvorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß am Übergang des dichtenden Abschnitts (114) des Ventilglieds (14) zur Ventildicht- fläche (24) eine Steuerkante (25) ausgebildet ist, die bei der Offnungshubbewegung aus dem Drosselabschnitt (21) der Bohrung (26) austritt.3. Fuel injection device according to claim 1 or 2, characterized in that at the transition of the sealing portion (114) of the valve member (14) to the valve sealing surface (24) a control edge (25) is formed, which during the opening stroke movement from the throttle portion (21 ) emerges from the bore (26).
4. Kraftstoffeinspritzvorrichtung nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß der Ventilsitz (22) als Ringschulter ausgebildet ist, die durch eine radiale Verengung der Bohrung (26) in Flußrichtung des Kraftstoffs gebildet ist.4. Fuel injection device according to one of claims 1 to 3, characterized in that the valve seat (22) is designed as an annular shoulder, which is formed by a radial narrowing of the bore (26) in the flow direction of the fuel.
5. Kraftstoffeinspritzvorrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß die Ventil- dichtfläche (24) als Ringschulter durch eine radiale Verengung des Ventilglieds (14) ausgebildet ist. 5. Fuel injection device according to one of the preceding claims, characterized in that the valve sealing surface (24) is designed as an annular shoulder by a radial narrowing of the valve member (14).
EP01940207A 2000-05-16 2001-05-03 Fuel injection system for an internal combustion engine Withdrawn EP1283954A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10023960 2000-05-16
DE10023960A DE10023960A1 (en) 2000-05-16 2000-05-16 Fuel injection device for internal combustion engine has choke gap formed between choke section upstream of valve seat in bore and casing surface
PCT/DE2001/001680 WO2001088367A1 (en) 2000-05-16 2001-05-03 Fuel injection system for an internal combustion engine

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EP1283954A1 true EP1283954A1 (en) 2003-02-19

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US (1) US20020113140A1 (en)
EP (1) EP1283954A1 (en)
JP (1) JP2003533637A (en)
KR (1) KR20020038691A (en)
CN (1) CN1380940A (en)
BR (1) BR0106642A (en)
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WO (1) WO2001088367A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10062966A1 (en) * 2000-12-16 2002-07-18 Bosch Gmbh Robert Single cylinder pump module for a fuel injection system of an internal combustion engine
US6390069B1 (en) * 2001-01-26 2002-05-21 Detroit Diesel Corporation Fuel injector assembly and internal combustion engine including same
DE10333787A1 (en) * 2003-07-24 2005-02-24 Volkswagen Mechatronic Gmbh & Co. Kg Pump-nozzle apparatus
DE10358010B3 (en) * 2003-12-11 2005-06-23 Volkswagen Mechatronic Gmbh & Co. Kg Pump-jet device for diesel engine fuel injection with pump, control valve and jet unit has throttle between working space of pump and discharge channel coupled to control space via valve element
DE102008040881A1 (en) * 2007-08-10 2009-02-26 Robert Bosch Gmbh Injection device for small power engine e.g. small internal combustion engine, of vehicle, has fuel pump, pressure regulator, injector and air controller arranged on common housing and formed as integral components of injection device
DE102009045995A1 (en) * 2009-10-26 2011-06-09 Robert Bosch Gmbh Fuel injector
JP5501272B2 (en) * 2011-03-08 2014-05-21 日立オートモティブシステムズ株式会社 High pressure fuel supply pump
US11260407B2 (en) 2016-08-30 2022-03-01 Ford Global Technologies, Llc Methods and systems for a fuel injector assembly
DE102018200715A1 (en) * 2018-01-17 2019-07-18 Robert Bosch Gmbh Fuel delivery device for cryogenic fuels

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3737100A (en) * 1971-11-18 1973-06-05 Allis Chalmers Internally cooled unit injector
US4572433A (en) * 1984-08-20 1986-02-25 General Motors Corporation Electromagnetic unit fuel injector
DE3523536A1 (en) 1984-09-14 1986-03-27 Robert Bosch Gmbh, 7000 Stuttgart Electrically controlled fuel injection pump for internal combustion engines
JPH07117012B2 (en) * 1986-09-05 1995-12-18 トヨタ自動車株式会社 Unit Injector
DE4142940C2 (en) * 1991-12-24 1994-01-27 Bosch Gmbh Robert Electrically controlled pump nozzle
DE4334802C1 (en) * 1993-10-13 1995-01-05 Mtu Friedrichshafen Gmbh Fuel injection system for diesel engines
US5443209A (en) * 1994-08-02 1995-08-22 Diesel Technology Company High pressure diesel fuel injector for internal combustion engines
DE19624001A1 (en) * 1996-06-15 1997-12-18 Bosch Gmbh Robert Fuel injection device for internal combustion engines
GB9616521D0 (en) * 1996-08-06 1996-09-25 Lucas Ind Plc Injector
DE19837332A1 (en) * 1998-08-18 2000-02-24 Bosch Gmbh Robert Control unit for controlling the build up of pressure in a pump unit such as an internal combustion engine fuel pump
US6158419A (en) * 1999-03-10 2000-12-12 Diesel Technology Company Control valve assembly for pumps and injectors

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0188367A1 *

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DE10023960A1 (en) 2001-11-22
KR20020038691A (en) 2002-05-23
CN1380940A (en) 2002-11-20
WO2001088367A1 (en) 2001-11-22
BR0106642A (en) 2002-04-16
JP2003533637A (en) 2003-11-11
US20020113140A1 (en) 2002-08-22

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