EP2116717B1 - Fuel injector - Google Patents

Fuel injector Download PDF

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Publication number
EP2116717B1
EP2116717B1 EP09100169A EP09100169A EP2116717B1 EP 2116717 B1 EP2116717 B1 EP 2116717B1 EP 09100169 A EP09100169 A EP 09100169A EP 09100169 A EP09100169 A EP 09100169A EP 2116717 B1 EP2116717 B1 EP 2116717B1
Authority
EP
European Patent Office
Prior art keywords
control valve
valve seat
valve element
fuel injector
adjustment axis
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.)
Expired - Fee Related
Application number
EP09100169A
Other languages
German (de)
French (fr)
Other versions
EP2116717A3 (en
EP2116717A2 (en
Inventor
Nadja Eisenmenger
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 EP2116717A2 publication Critical patent/EP2116717A2/en
Publication of EP2116717A3 publication Critical patent/EP2116717A3/en
Application granted granted Critical
Publication of EP2116717B1 publication Critical patent/EP2116717B1/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
    • F02M63/004—Sliding valves, e.g. spool valves, i.e. whereby the closing member has a sliding movement along a seat for opening and closing
    • F02M63/0042—Sliding valves, e.g. spool valves, i.e. whereby the closing member has a sliding movement along a seat for opening and closing combined with valve seats of the lift valve type
    • 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
    • F02M63/007—Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059
    • F02M63/0071—Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059 characterised by guiding or centering means in valves including the absence of any guiding means, e.g. "flying arrangements"
    • 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
    • F02M63/007—Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059
    • F02M63/0077—Valve seat details
    • 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
    • F02M63/007—Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059
    • F02M63/0078—Valve member details, e.g. special shape, hollow or fuel passages in the valve member
    • F02M63/008—Hollow valve members, e.g. members internally guided
    • 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
    • F02M63/007—Details not provided for in, or of interest apart from, the apparatus of the groups F02M63/0014 - F02M63/0059

Definitions

  • the invention relates to a fuel injector, in particular a common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine according to the preamble of claim 1.
  • the EP 1 612 403 A1 is a common rail injector with a pressure balanced in the axial direction control valve known.
  • the control valve which has a sleeve-shaped control valve element, the fuel pressure can be influenced within a control chamber bounded on the end side by an injection valve element.
  • the injection valve element is adjusted between an open position and a closed position, wherein the injection valve element releases the fuel flow into the combustion chamber of the internal combustion engine in its open position.
  • the sleeve-shaped control valve element is connected to an armature plate, which cooperates with an electromagnetic actuator for axial displacement of the control valve element.
  • a guide extension is provided, which is integrally formed with a bottom plate on which a cooperating with the control valve element control valve seat is arranged.
  • an injection valve with a control valve in which the control valve member cooperates with a transversely to the direction of movement movable member on which the control valve seat is formed.
  • the invention has for its object to propose a fuel injector with a sleeve-shaped control valve element, wherein the demands on the precision of the sealing surface and the control valve element seat are minimized while ensuring full functionality.
  • the invention is based on the idea of arranging the control valve seat element which is stationary in the prior art so as to be movable relative to the, in particular axial, adjustment axis of the control valve element.
  • the control valve seat element itself can be aligned relative to the sleeve-shaped control valve element, whereby depending on the degree of freedom of movement of the control valve seat element between existing control valve seat member and control valve element existing coaxial and / or angular errors can be compensated.
  • Due to the possibility for automatic alignment of the control valve seat element relative to the adjustment axis of the control valve seat element relative to the adjustment axis of the control valve element requirements on the precision of the sealing surface and the control valve seat can be minimized without functional losses would have to be accepted. Overall, this results in a cost-effectively producible, particularly robust fuel injector.
  • control valve seat element preferably in the axial direction
  • the component on which the control valve seat element, preferably in the axial direction, is supported itself is movable relative to the adjusting axis of the control valve element.
  • control valve seat element is arranged to be pivotable relative to the adjustment axis movable member and the component itself is slidably disposed to the adjustment axis of the control valve element.
  • an embodiment can be realized in which the control valve element is not completely pressure balanced, but only approximately in the axial direction pressure balanced.
  • a pressure stage acting in the closing direction of the control valve seat element is preferably realized.
  • the inner guide diameter of the control valve element is only slightly larger than the diameter of the sealing line.
  • control valve seat member is slidably disposed relative to the adjustment axis of the control valve element, preferably perpendicular to the adjustment axis of the control valve element.
  • control valve seat element is arranged pivotable and / or unrollable relative to the adjustment axis, preferably in the manner of a ball joint.
  • control valve seat member preferably in the axial direction
  • a component which is arranged fixed relative to the adjustment axis of the control valve member.
  • a relative to the adjustment axis displaceable arrangement of the control valve seat element can be realized in a particularly simple and effective manner.
  • the control valve seat element is held exclusively by the fuel pressure within the fuel injector on the component, ie, a hydraulic force is applied against the component.
  • control valve seat element has at least one part-spherical section, or is completely formed as a ball.
  • the part spherical portion may face the control valve seat and / or a part spherical portion may serve to support the control valve seat on a member either stationary relative to the adjustment axis of the control valve member or movable, preferably displaceable, is arranged to this adjustment axis.
  • control valve seat on the control valve seat element
  • the control valve seat member is either completely formed as a ball or at least a part-spherical, the control valve seat having forming portion.
  • an embodiment of the control valve seat element can be realized with an inner cone-shaped, in particular an inner cone-shaped, control valve seat, or with an outer cone-shaped, in particular an outer cone-shaped, control valve seat.
  • Such a conical control valve seat can also be combined with a control valve seat element which has a part-spherical section, in particular for supporting the control valve seat element on an adjacent component.
  • control valve seat as a flat seat on the control valve seat element, wherein also in such an embodiment, the control valve seat member, in particular for supporting the control valve seat member on a, in particular axial component, may have a part-spherical portion.
  • the optionally provided part-spherical section preferably serves to realize a pivotable arrangement of the control valve seat element relative to the adjustment axis.
  • control valve in which the control valve element is directed downwards, i. opens in the direction of the injection valve element seat.
  • the control valve element is directed downwards, i. opens in the direction of the injection valve element seat.
  • an embodiment with an upward-opening control valve element is also feasible, in the case of an otherwise conventional construction, a correspondingly long drainage channel must be provided through which fuel can flow from the control chamber to the control valve seat.
  • an embodiment is preferred in which the adjustment axis of the control valve element is aligned in the axial direction with the adjustment axis of the injection valve element. It is also an embodiment feasible, in which the adjustment axis of the control valve element and the adjustment axis of the injection valve element are arranged transversely to the longitudinal extent of the adjustment axes offset from each other. Such an embodiment is suitable for minimizing the injector body volume, in particular when the base plate having the guide extension for guiding the control valve seat is formed as a separate component by a throttle plate which has the outlet throttle and / or the inlet throttle for a control chamber.
  • Fig. 1 is a trained as a common rail injector fuel injector 1 for injecting fuel in a combustion chamber, not shown, also shown an internal combustion engine of a motor vehicle.
  • a high pressure pump 2 delivers fuel from a reservoir 3 in a high-pressure fuel storage 4 (Rail). In this fuel, especially diesel or gasoline, under high pressure, of about 2000 bar in this embodiment, stored.
  • the fuel injector 1 is connected, among other injectors, not shown, via a supply line 5.
  • the supply line 5 opens into a supply channel 6, which in turn opens into a pressure chamber 7 (high-pressure region) of the fuel injector 1.
  • the fuel flowing into the pressure chamber 7 flows in an injection process directly into the combustion chamber of the internal combustion engine.
  • the fuel injector 1 is connected via an injector return port 8 to a return line 9. Via the return line 9, a later to be explained control amount of fuel from the fuel injector 1 to flow to the reservoir 3 and fed from there from the high pressure circuit again.
  • injection valve element 11 Within an injector body 10 is a one-piece in this embodiment injection valve element 11, which may be designed in several parts if necessary, adjustable in the axial direction.
  • the injection valve element 11 is guided within an axially adjacent to the injector body 10 nozzle body 12 at its outer periphery. This only partially shown nozzle body 12 is clamped by means of a union nut, not shown, with the injector body 10.
  • the injection valve element 11 has at its tip 13 a closing surface 14 (sealing surface) with which the injection valve element 11 can be attached in a tight contact with a single point valve element seat 15 formed inside the nozzle body 12.
  • fuel can flow from the pressure chamber 7 through axial passages 18 formed in a guide section 17 on the outer circumference of the injection valve element 11 into a lower annular space 19 formed radially between the injection valve element 11 and the nozzle body 12 in the drawing plane the injection valve element 11 to flow past the nozzle hole assembly 16 and there are injected substantially under high pressure (rail pressure) standing in the combustion chamber.
  • a control chamber 23 is limited, via a radially extending in the sleeve-shaped portion of the throttle plate 22 inlet throttle 24 under high pressure fuel from the pressure chamber. 7 is supplied.
  • the sleeve-shaped section 21 with the control chamber 23 enclosed therein is enclosed radially on the outside by high-pressure fuel, so that an annular guide gap 25 is comparatively fuel-tight radially between the sleeve-shaped section 21 and the injection valve element 11.
  • To increase the fuel-tightness of the guide gap 25 are two in axially spaced annular grooves 26 provided on the outer circumference of the injection valve element 11 within the sleeve-shaped portion 21.
  • the control chamber 23 is connected via a flow restrictor 28 having a drain passage 27 with a valve chamber 29.
  • the valve chamber 29 is surrounded radially on the outside by a sleeve-shaped control valve element 31 which is axially adjustable along an adjustment axis 30.
  • the adjustment axis 30 of the control valve element 31 is aligned with a central axis in the fuel injector 1 adjustment axis of the injection valve element 11.
  • the sleeve-shaped control valve element 31 is part of a pressure-balanced in the axial direction of the control valve 32 (servo valve).
  • fuel can flow into a low-pressure region 33 of the fuel injector 1 and from there to the injector return port 8, when the sleeve-shaped control valve element 31, which is formed integrally with an anchor plate 34 in the embodiment shown, lifted from its spherical control valve seat 35 , ie the control valve 32 is open.
  • the sleeve-shaped control valve element 31 To open the control valve 32, the sleeve-shaped control valve element 31 must be adjusted in the drawing plane downwards in the direction of the injection valve element 11.
  • an electromagnetic actuator 36 with an electromagnet 37 (coil) is provided, which cooperates with the armature plate 34 and in sequence with the control valve element 31 with appropriate energization.
  • the actuator 36 is disposed axially between the armature plate 34 and the throttle plate 22.
  • the sleeve-shaped control valve element 31 in the axial direction in the plane of the drawing down along the adjustment axis 30 in the direction of the injection valve element seat 15 to adjusted and lifts it from its control valve seat 35 from.
  • the flow cross sections of the inlet throttle 24 and the outlet throttle 28 are matched to one another such that when open control valve 32, a net outflow of fuel (fuel control amount) from the control chamber 23 via the valve chamber 29 in the low pressure region 33 of the fuel injector 1 and from there via the Injector return port 8 and the return line 9 results in the reservoir 3.
  • the pressure of the control chamber 23 decreases rapidly, whereby the injection valve element 11 lifts from its injection valve element seat 15, whereby fuel in the sequence from the pressure chamber 7 through the nozzle hole assembly 16 can flow into the combustion chamber.
  • the energization of the electromagnetic actuator 36 is interrupted, whereby the sleeve-shaped control valve member 31 by means of a control spring 38, which is supported on the anchor plate 34 and on a ring member 39 which rests on the throttle plate 22, in the plane of the drawing up its control valve seat 35 is adjusted.
  • the fuel flowing in through the inlet throttle 24 into the control chamber 23 ensures rapid pressure increase in the control chamber 23 and thus a closing force acting on the injection valve element 11. This results in that the injection valve element 11 is moved in the drawing plane down to the injection valve element seat 15, whereby the injection process is terminated.
  • a guide extension 40 is formed, which projects in the axial direction upwards.
  • the drain passage 27 from the control chamber 23 passes through this guide extension 40, in which the outlet throttle 28 is arranged, centric.
  • the guide extension 40 extends into the sleeve-shaped control valve element 31 and serves to guide it during an adjustment movement along the adjustment axis 30.
  • the control valve seat 35 is formed by a control valve seat member 41, which is formed in the embodiment shown as a ball.
  • the spherical control valve seat element 41 is supported in the axial direction on a component 42, which in turn is loosely supported on a plate 43, which in turn rests in the axial direction loosely on a threaded insert 44.
  • the component 42 has a dome-shaped portion 45. This is formed as a part-spherical recess, wherein the part-spherical recess has a larger radius of curvature than the radius of curvature of the spherical control valve seat member 41, for alignment purposes, a rolling of the control valve seat member 41 within the section 45, i. within the recess, relative to the adjustment axis 30, to allow.
  • the diameter of the plate 43 corresponds approximately to the diameter of a bore 46 in a valve element 47, with which the threaded insert 44 is screwed. As a result, no lateral adjustment of the plate 43 within the bore 46 is possible.
  • the diameter of the axially immediately adjacent to the plate 43 disposed member 42 is dimensioned slightly smaller than the diameter of the bore 46, so that the component 42 with its dome-shaped portion 45 relative to the adjustment axis 30, namely perpendicular to this, is displaceable.
  • the control valve seat member 41 in turn can roll within the portion 45 of the component 42.
  • both the control valve seat member 41, and the member 42 and the plate 44 are loose (axially adjustable) within the bore 46 of a valve member 47.
  • the control valve seat member 41 is in operation of the located within the drain passage 27, under high pressure standing fuel in the axial direction upwards pressed directly against the component 42, whereby this in turn is pressed directly in the plane of the drawing up against the plate 43, which in turn is subjected to force against the threaded insert 44.
  • valve member 47 is screwed to the injector body 10 and clamps the actuator 36 against the throttle plate 22, which is supported in the axial direction on an inner annular shoulder 48 of the injector body 10.
  • An end-face sealing surface 49 (ring line), with which the control valve member 31 is supported on the control valve seat member 41, is formed inside a conical shape, wherein a not shown, formed by the sealing surface 49 sealing line at least approximately the same diameter, as the guide extension 40 so as to realize a pressure balance of the control valve 32.
  • Fig. 2 an alternative embodiment of a fuel injector 1 is shown.
  • the operation of the fuel injector 1 according to Fig. 2 corresponds substantially to the operation of the fuel injector 1 according to Fig. 1 , so that in order to avoid repetition in the following essentially the differences to the fuel injector 1 described above are set forth. With regard to the similarities is on the previous figure description as well as on Fig. 1 directed.
  • Fig. 2 It can be seen that the adjustment axis 30 of the sleeve-shaped control valve element 31 is arranged offset radially to an injection valve element adjustment axis 50.
  • the arranged in the pressure chamber 7 control chamber 23 is bounded radially outwardly by a sleeve member 51 which is supported in the axial direction of a throttle plate 22.
  • This throttle plate 22 has, in addition to the outlet throttle 28, the inlet throttle 24 for supplying the control chamber 23, wherein the inlet throttle 24 may alternatively be arranged as a radial passage in the sleeve member 51.
  • the sleeve member 51 is pressed by means of a closing spring 52 in the axial direction in the drawing plane up against the throttle plate 22, wherein the closing spring 52 is supported in the axial direction on a peripheral collar 53 of the one-piece injection valve element 11.
  • the closing spring 52 supports the closing movement of the injection valve element 11.
  • a bottom plate 54 Located on the throttle plate 22 is located axially on a bottom plate 54, within which the drain passage 27 continues in the plane of the drawing upwards. Integral with the bottom plate 54 of the guide extension 40 is formed, which serves to guide the sleeve-shaped control valve member 31 during its axial movement.
  • the bottom plate 54 may be formed as a rotationally symmetrical component, in which case the adjustment axis 30 of the control valve element 31 is aligned in the axial direction with the Einspritzventilelementverstellachse 50.
  • the injection valve member 31 is supported in the axial direction in the plane upwards on a designed as a ball control valve seat member 41 which is relatively unrolled relative to the adjustment axis 30 within a dome-shaped portion 45 of an axially adjacent component 42.
  • the component 42 in turn, together with the control valve seat element 41 is received transversely to the adjustment axis 30 of the control valve element 31 displaceable within a bore 46 in the injector body 10.
  • Fig. 3 is an enlarged version of the in the Fig. 1 and 2 realized control valve seat member 41 shown. This is shaped as a ball. It can be seen that the diameter D D of a front face on the control valve seat member 41 formed sealing surface (sealing line) corresponds to the guide diameter D F , at which the control valve element 31 is guided on the guide extension 40. It can also be seen that the radius of curvature of the spherical control valve seat element 41 is less than the radius of curvature of the part-spherical recess which forms the dome-shaped portion 45 of the component 42 displaceably arranged relative to the adjustment axis 30.
  • control valve seat member 41 is formed at least approximately hemispherical, wherein the control valve seat member 41 is supported with a flat portion 59 on a component 42 which is stationary relative to the adjustment axis 30 is arranged.
  • the control valve seat member 41 is slidably disposed relative to the adjustment axis 30 along the component 42, so that coaxial errors can be compensated.
  • the diameter D D of the sealing surface (seal line) also corresponds in the embodiment shown, the guide diameter D F.
  • the control valve seat 35 is formed partially spherical.
  • Fig. 5 an alternative embodiment is shown, wherein the control valve seat 35 is formed as an inner cone-shaped inner cone.
  • the cone angle of the control valve seat 35 is greater than the cone angle of the front side formed on the control valve element 31 cone.
  • the control valve seat member 41 is transverse to the adjustment axis 30, that is, relative to this, slidably disposed along the component 42, whereby coaxial errors can be compensated.
  • a part-spherical, at least approximately hemispherical, control valve seat member 41 is provided, wherein in the embodiment shown, a flat portion 59 of the control valve seat member 41 forms the formed as a flat seat control valve seat 35.
  • the control valve seat element 41 is received in an internal conical recess 61 of the component 42.
  • angle errors can be corrected, in the event that the component 42 is arranged stationary to the adjustment axis 30.
  • coaxial errors of the control valve element 31 can be compensated relative to the control valve seat 35 formed as a flat seat.
  • the control valve seat element 41 which can be adjusted transversely to the adjustment axis 30, has a control valve seat 35 designed as an outer cone.
  • the diameter D D of the annular sealing surface (sealing line) at least approximately corresponds to the guide diameter D F , so that a pressure-balanced in the axial direction control valve is obtained.

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  • 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)

Description

Stand der TechnikState of the art

Die Erfindung betrifft einen Kraftstoff-Injektor, insbesondere einen Common-Rail-Injektor, zum Einspritzen von Kraftstoff in einen Brennraum einer Brennkraftmaschine gemäß dem Oberbegriff des Anspruchs 1.The invention relates to a fuel injector, in particular a common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine according to the preamble of claim 1.

Aus der EP 1 612 403 A1 ist ein Common-Rail-Injektor mit einem in axialer Richtung druckausgeglichenen Steuerventil bekannt. Mittels des Steuerventils, das ein hülsenförmiges Steuerventilelement aufweist, kann der Kraftstoffdruck innerhalb einer von einem Einspritzventilelement stirnseitig begrenzten Steuerkammer beeinflusst werden. Durch die Variation des Kraftstoffdruckes innerhalb der Steuerkammer wird das Einspritzventilelement zwischen einer Öffnungsstellung und einer Schließstellung verstellt, wobei das Einspritzventilelement in seiner Öffnungsstellung den Kraftstofffluss in den Brennraum der Brennkraftmaschine freigibt. Das hülsenförmige Steuerventilelement ist mit einer Ankerplatte verbunden, die mit einem elektromagnetischen Aktuator zum axialen Verstellen des Steuerventilelementes zusammenwirkt. Zur Führung des hülsenförmigen Steuerventilelementes ist ein Führungsfortsatz vorgesehen, der einteilig mit einer Bodenplatte ausgebildet ist, an der ein mit dem Steuerventilelement zusammenwirkender Steuerventilsitz angeordnet ist. Nachteilig bei dem bekannten Kraftstoff-Injektor ist, dass die mit dem Steuerventilsitz zusammenwirkende Dichtfen und sehr präzise auf den Steuerventilelementsitz ausgerichtet werden muss, was die Fertigung aufwändig und damit teuer macht.From the EP 1 612 403 A1 is a common rail injector with a pressure balanced in the axial direction control valve known. By means of the control valve, which has a sleeve-shaped control valve element, the fuel pressure can be influenced within a control chamber bounded on the end side by an injection valve element. By varying the fuel pressure within the control chamber, the injection valve element is adjusted between an open position and a closed position, wherein the injection valve element releases the fuel flow into the combustion chamber of the internal combustion engine in its open position. The sleeve-shaped control valve element is connected to an armature plate, which cooperates with an electromagnetic actuator for axial displacement of the control valve element. To guide the sleeve-shaped control valve element, a guide extension is provided, which is integrally formed with a bottom plate on which a cooperating with the control valve element control valve seat is arranged. A disadvantage of the known fuel injector that cooperates with the control valve seat Dichtfen and must be aligned very precisely on the control valve element seat, which makes the production complex and therefore expensive.

Aus der DE 10 2006 050 042 A1 ist darüber hinaus ein Einspritzventil mit einem Steuerventil bekannt, bei dem das Steuerventilglied mit einem quer zu dessen Bewegungsrichtung beweglichen Bauteil zusammenwirkt, an dem der Steuerventilsitz ausgebildet ist.From the DE 10 2006 050 042 A1 In addition, an injection valve with a control valve is known in which the control valve member cooperates with a transversely to the direction of movement movable member on which the control valve seat is formed.

Offenbarung der ErfindungDisclosure of the invention Technische AufgabeTechnical task

Der Erfindung liegt die Aufgabe zugrunde, einen Kraftstoff-Injektor mit einem hülsenförmigen Steuerventilelement vorzuschlagen, bei dem die Ansprüche an die Präzision der Dichtfläche und des Steuerventilelementsitzes bei Gewährleistung einer vollen Funktionalität minimiert sind.The invention has for its object to propose a fuel injector with a sleeve-shaped control valve element, wherein the demands on the precision of the sealing surface and the control valve element seat are minimized while ensuring full functionality.

Technische LösungTechnical solution

Diese Aufgabe wird mit einem Kraftstoff-Injektor mit den Merkmalen des Anspruchs 1 gelöst. Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen angegeben. In den Rahmen der Erfindung fallen sämtliche Kombinationen aus zumindest zwei von in der Beschreibung, den Ansprüchen und/oder den Figuren offenbarten Merkmalen.This object is achieved with a fuel injector having the features of claim 1. Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention.

Der Erfindung liegt der Gedanke zugrunde, das im Stand der Technik ortsfeste Steuerventilsitzelement relativ zur, insbesondere axialen, Verstellachse des Steuerventilelementes bewegbar anzuordnen. Hierdurch kann sich das Steuerventilsitzelement selbst relativ zu dem hülsenförmigen Steuerventilelement ausrichten, wodurch je nach Bewegungsfreiheitsgrad des Steuerventilsitzelementes ggf. zwischen Steuerventilsitzelement und Steuerventilelement bestehende Koaxial- und/oder Winkelfehler ausgeglichen werden können. Aufgrund der Möglichkeit zur automatischen Ausrichtung des Steuerventilsitzelementes relativ zur Verstellachse des Steuer-ventilsitzelementes relativ zur Verstellachse des Steuerventilelementes können die Anforderungen an die Präzision der Dichtfläche und des Steuerventilsitzes minimiert werden, ohne dass funktionelle Einbußen hingenommen werden müssten. Ingesamt wird hierdurch ein kostengünstig herstellbarer, besonders robuster Kraftstoff-Injektor erhalten.The invention is based on the idea of arranging the control valve seat element which is stationary in the prior art so as to be movable relative to the, in particular axial, adjustment axis of the control valve element. As a result, the control valve seat element itself can be aligned relative to the sleeve-shaped control valve element, whereby depending on the degree of freedom of movement of the control valve seat element between existing control valve seat member and control valve element existing coaxial and / or angular errors can be compensated. Due to the possibility for automatic alignment of the control valve seat element relative to the adjustment axis of the control valve seat element relative to the adjustment axis of the control valve element requirements on the precision of the sealing surface and the control valve seat can be minimized without functional losses would have to be accepted. Overall, this results in a cost-effectively producible, particularly robust fuel injector.

Zudem ist das Bauteil, an dem sich das Steuerventilsitzelement, vorzugsweise in axialer Richtung, abstützt, selbst relativ zur Stellachse des Steuerventilelementes bewegbar ist. Dabei ist eine Ausführungsform besonders bevorzugt, bei der das Steuerventilsitzelement zu dem relativ zur Verstellachse beweglichen Bauteil verschwenkbar angeordnet ist und das Bauteil selbst zur Verstellachse des Steuerventilelementes verschiebbar angeordnet ist. Auch hierbei ist es von Vorteil, das Steuerventilelement ausschließlich durch Kraftstoff-Druck an dem Bauteil zu halten. Anders ausgedrückt eignet sich die beschriebene Ausführungsvariante mit zwei relativ zur Verstellachse des Steuerventilelementes beweglichen Bauelementen (Steuerventilelement + Bauteil) zur Realisierung einer automatischen Korrektur sowohl von Koaxial- als auch von Winkelfehlern.In addition, the component on which the control valve seat element, preferably in the axial direction, is supported, itself is movable relative to the adjusting axis of the control valve element. In this case, an embodiment is particularly preferred in which the control valve seat element is arranged to be pivotable relative to the adjustment axis movable member and the component itself is slidably disposed to the adjustment axis of the control valve element. Again, it is advantageous to hold the control valve element exclusively by fuel pressure on the component. In other words, the embodiment described with two relatively movable to the adjustment of the control valve element components (control valve element + component) for realizing an automatic correction of both coaxial and angle errors.

Von besonderem Vorteil ist eine Ausführungsform des, vorzugsweise als 2/2-Wegeventil ausgebildeten, Steuerventils bzw. des Steuerventilelementes, bei der dieses in seiner Schließstellung in axialer Richtung druckausgeglichen ist. Dies kann bei einem hülsenförmigen Steuerventilelement auf einfache Weise dadurch realisiert werden, dass der Durchmesser der Dichtlinie, mit dem das Steuerventilsitzelement am Steuerventilsitz anliegt, dem axial beabstandeten, inneren Führungsdurchmesser des Steuerventilelementes entspricht. Eine derartige Ausführungsform des Kraftstoff-Injektors eignet sich insbesondere zum Einsatz bei Rail-Drücken jenseits von 1800 bar. Die Realisierung einer axialen Druckausgeglichenheit ermöglicht daher den Einsatz kleinerer (leistungsschwächerer), insbesondere elektromagnetischer, Aktuatoren und Steuerschließfedern. Um die Gefahr von Prellern beim Schließen des Steuerventilelementes zu minimieren, kann auch eine Ausführungsform realisiert werden, bei der das Steuerventilelement nicht vollständig, sondern nur näherungsweise in axialer Richtung druckausgeglichen ist. Bevorzugt wird hierbei eine in Schließrichtung des Steuerventilsitzelementes wirkende Druckstufe realisiert. Hierzu ist der innere Führungsdurchmesser des Steuerventilelementes lediglich etwas größer zu wählen als der Durchmesser der Dichtlinie.Of particular advantage is an embodiment of, preferably designed as a 2/2-way valve, control valve or the control valve element, in which this is pressure balanced in its closed position in the axial direction. This can be realized in a sleeve-shaped control valve element in a simple manner in that the diameter of the sealing line with which the control valve seat member abuts the control valve seat corresponds to the axially spaced, inner guide diameter of the control valve element. Such an embodiment of the fuel injector is particularly suitable for use at rail pressures beyond 1800 bar. The realization of an axial pressure balance therefore allows the use of smaller (less powerful), in particular electromagnetic, actuators and control closing springs. In order to minimize the risk of bouncing when closing the control valve element, an embodiment can be realized in which the control valve element is not completely pressure balanced, but only approximately in the axial direction pressure balanced. In this case, a pressure stage acting in the closing direction of the control valve seat element is preferably realized. For this purpose, the inner guide diameter of the control valve element is only slightly larger than the diameter of the sealing line.

Zum Ausgleichen von Koaxialfehlern zwischen dem Steuerventilelement und dem Steuerventilsitzelement ist eine Ausführungsform bevorzugt, bei der das Steuerventilsitzelement relativ zur Verstellachse des Steuerventilelementes verschiebbar angeordnet ist, vorzugsweise senkrecht zur Verstellachse des Steuerventilelementes. Zusätzlich oder alternativ zu einer verschiebbaren Anordnung des Steuerventilsitzelementes relativ zur Verstellachse des Steuerventilelementes ist, insbesondere zum Ausgleich von Winkelfehlern, eine Ausführungsform bevorzugt, bei der das Steuerventilsitzelement relativ zur Verstellachse verschwenkbar und/oder abrollbar angeordnet ist, vorzugsweise in der Art eines Kugelgelenks.To compensate for coaxial errors between the control valve member and the control valve seat member, an embodiment is preferred in which the control valve seat member is slidably disposed relative to the adjustment axis of the control valve element, preferably perpendicular to the adjustment axis of the control valve element. In addition or as an alternative to a displaceable arrangement of the control valve seat element relative to the adjustment axis of the control valve element, an embodiment is preferred, in particular for compensating angular errors, in which the control valve seat element is arranged pivotable and / or unrollable relative to the adjustment axis, preferably in the manner of a ball joint.

Es ist eine Ausführungsform des Kraftstoff-Injektors realisierbar, welche nicht Teil der Erfindung ist, bei der sich das Steuerventilsitzelement, vorzugsweise in axialer Richtung, an einem Bauteil abstützt, das relativ zur Verstellachse des Steuerventilelementes ortsfest angeordnet ist. Hierdurch kann auf besonders einfache und effektive Weise eine relativ zur Verstellachse verschiebbare Anordnung des Steuerventilsitzelementes realisiert werden. Von besonderem Vorteil ist dabei eine Ausführungsform, bei der das Steuerventilsitzelement ausschließlich von dem Kraftstoff-Druck innerhalb des Kraftstoff-Injektors an dem Bauteil gehalten, d.h. gegen das Bauteil mit einer hydraulischen Kraft beaufschlagt ist.It is an embodiment of the fuel injector feasible, which is not part of the invention, in which the control valve seat member, preferably in the axial direction, is supported on a component which is arranged fixed relative to the adjustment axis of the control valve member. As a result, a relative to the adjustment axis displaceable arrangement of the control valve seat element can be realized in a particularly simple and effective manner. Of particular advantage in this case is an embodiment in which the control valve seat element is held exclusively by the fuel pressure within the fuel injector on the component, ie, a hydraulic force is applied against the component.

Um eine besonders hohe Robustheit des Kraftstoff-Injektors, insbesondere gegenüber im Kraftstoff befindlichen Partikeln, zu realisieren, ist eine Ausführungsform bevorzugt, bei der das Steuerventilsitzelement mindestens einen teilkugelförmigen Abschnitt aufweist, oder vollständig als Kugel ausgebildet ist. Bei einer Ausführungsform, bei der das Steuerventilsitzelement mindestens einen teilkugelförmigen Abschnitt aufweist, kann der teilkugelförmige Abschnitt dem Steuerventilsitz zugewandt sein und/oder ein teilkugelförmiger Abschnitt kann zum Abstützen des Steuerventilsitzes an einem Bauteil dienen, das entweder ortsfest relativ zur Verstellachse des Steuerventilelementes oder beweglich, vorzugsweise verschiebbar, zu dieser Verstellachse angeordnet ist.In order to realize a particularly high robustness of the fuel injector, in particular with respect to particles located in the fuel, an embodiment is preferred in which the control valve seat element has at least one part-spherical section, or is completely formed as a ball. In an embodiment where the control valve seat member has at least one part spherical portion, the part spherical portion may face the control valve seat and / or a part spherical portion may serve to support the control valve seat on a member either stationary relative to the adjustment axis of the control valve member or movable, preferably displaceable, is arranged to this adjustment axis.

Im Hinblick auf die geometrische Ausbildung des Steuerventilsitzes am Steuerventilsitzelement gibt es unterschiedliche Möglichkeiten. So ist es möglich, den Steuerventilsitz teilkugelförmig auszubilden, wobei hierzu das Steuerventilsitzelement entweder vollständig als Kugel ausgebildet ist oder zumindest einen teilkugelförmigen, den Steuerventilsitz bildenden Abschnitt aufweist. Alternativ ist eine Ausführungsform des Steuerventilsitzelementes mit einem innenkegelförmigen, insbesondere einem innenkonusförmigen, Steuerventilsitz, oder mit einem außenkegelförmigen, insbesondere einem außenkonusförmigen, Steuerventilsitz realisierbar. Auch ein derartiger kegelförmiger Steuerventilsitz ist mit einem Steuerventilsitzelement kombinierbar, das einen teilkugelförmigen Abschnitt, insbesondere zum Abstützen des Steuerventilsitzelementes an einem benachbarten Bauteil aufweist. Weiter alternativ ist es möglich, den Steuerventilsitz als Flachsitz am Steuerventilsitzelement auszubilden, wobei auch bei einer derartigen Ausführungsform das Steuerventilsitzelement, insbesondere zum Abstützen des Steuerventilsitzelementes an einem, insbesondere axialen Bauteil, einen teilkugelförmigen Abschnitt aufweisen kann.With regard to the geometric design of the control valve seat on the control valve seat element, there are different possibilities. Thus, it is possible to form the control valve seat part-spherical, for which purpose the control valve seat member is either completely formed as a ball or at least a part-spherical, the control valve seat having forming portion. Alternatively, an embodiment of the control valve seat element can be realized with an inner cone-shaped, in particular an inner cone-shaped, control valve seat, or with an outer cone-shaped, in particular an outer cone-shaped, control valve seat. Such a conical control valve seat can also be combined with a control valve seat element which has a part-spherical section, in particular for supporting the control valve seat element on an adjacent component. Further alternatively, it is possible to form the control valve seat as a flat seat on the control valve seat element, wherein also in such an embodiment, the control valve seat member, in particular for supporting the control valve seat member on a, in particular axial component, may have a part-spherical portion.

Bei sämtlichen zuvor beschriebenen Steuerventilsitzelementvarianten dient der ggf. vorgesehene teilkugelförmige Abschnitt bevorzugt zur Realisierung einer verschwenkbaren Anordnung des Steuerventilsitzelementes relativ zur Verstellachse.In all previously described control valve seat element variants, the optionally provided part-spherical section preferably serves to realize a pivotable arrangement of the control valve seat element relative to the adjustment axis.

Besonders bevorzugt ist eine Ausführungsform des Steuerventils, bei der das Steuerventilelement nach unten, d.h. in Richtung des Einspritzventilelementsitzes öffnet. Zwar ist auch eine Ausführungsform mit nach oben öffnendem Steuerventilelement realisierbar - hier muss jedoch bei ansonsten üblicher Bauweise ein entsprechend langer Ablaufkanal vorgesehen werden, durch den Kraftstoff aus der Steuerkammer zum Steuerventilsitz strömen kann.Particularly preferred is an embodiment of the control valve in which the control valve element is directed downwards, i. opens in the direction of the injection valve element seat. Although an embodiment with an upward-opening control valve element is also feasible, in the case of an otherwise conventional construction, a correspondingly long drainage channel must be provided through which fuel can flow from the control chamber to the control valve seat.

Insbesondere dann, wenn ein Führungsfortsatz zur Realisierung einer inneren Führung für das hülsenförmige Steuerventilelement an einer Drosselplatte ausgebildet ist, ist eine Ausführungsform bevorzugt, bei der die Verstellachse des Steuerventilelementes in axialer Richtung mit der Verstellachse des Einspritzventilelementes fluchtet. Es ist auch eine Ausführungsform realisierbar, bei der die Verstellachse des Steuerventilelementes und die Verstellachse des Einspritzventilelementes quer zur Längserstreckung der Verstellachsen versetzt zueinander angeordnet sind. Eine derartige Ausführungsform eignet sich zur Minimierung des Injektorbauvolumens insbesondere dann, wenn die den Führungsfortsatz zur Führung des Steuerventilsitzes aufweisende Bodenplatte von einer Drosselplatte, die die Ablaufdrossel und/oder die Zulaufdrossel für eine Steuerkammer aufweist, als separates Bauteil ausgebildet ist.In particular, when a guide extension for the realization of an inner guide for the sleeve-shaped control valve element is formed on a throttle plate, an embodiment is preferred in which the adjustment axis of the control valve element is aligned in the axial direction with the adjustment axis of the injection valve element. It is also an embodiment feasible, in which the adjustment axis of the control valve element and the adjustment axis of the injection valve element are arranged transversely to the longitudinal extent of the adjustment axes offset from each other. Such an embodiment is suitable for minimizing the injector body volume, in particular when the base plate having the guide extension for guiding the control valve seat is formed as a separate component by a throttle plate which has the outlet throttle and / or the inlet throttle for a control chamber.

Kurze Beschreibung der ZeichnungenBrief description of the drawings

Weitere Vorteile, Merkmale und Einzelheiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung bevorzugter Ausführungsbeispiele sowie anhand der Zeichnungen. Diese zeigen in:

Fig. 1:
eine ausschnittsweise, schematische Darstellung eines Kraftstoff-Injektors mit einem kugelförmigen Steuerventilsitzelement, das relativ zu einer Ver- stellachse eines hülsenförmigen Steuerventilele- mentes verschwenkbar ist, wobei sich das kugelför- mige Steuerventilsitzelement an einem Bauteil in axialer Richtung abstützt, das quer relativ zur Verstellachse verschiebbar angeordnet ist,
Fig. 2:
eine alternative Ausführungsform eines Kraftstoff- Injektors, bei dem eine Verstellachse des Steuer- ventilelementes relativ zu einer Verstellachse des Einspritzventilelementes versetzt angeordnet ist,
Fig. 3:
eine vergrößerte Darstellung der Ausbildung und Anordnung eines Steuerventilsitzelementes gemäß den Fig. 1 und 2,
Fig. 4:
eine Ausführungsform eines Steuerven- tilsitzes, welche nicht Teil der Erfindung ist, bei dem sich ein teilkugelförmiges Steuerventilsitzelement verschiebbar an einem ortsfest zur Verstellachse des Steuerventilelemen- tes angeordneten Bauteil abstützt,
Fig. 5:
eine alternative Ausführungsform eines relativ zur Verstellachse des Steuerventilelementes verschieb- baren Steuerventilsitzelementes mit einem innenke- gelförmigen Steuerventilsitz,
Fig. 6:
eine alternative Ausführungsform eines Steuerven- tilsitzelementes mit einem Flachsitz und einem ku- gelförmigen Abschnitt zur Realisierung einer Schwenkbewegung relativ zur Verstellachse des Steuerventilelementes und
Fig. 7:
eine alternative Ausführungsform eines Steuerven- tilsitzelementes mit einem außenkegelförmigen Steuerventilsitz.
Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. These show in:
Fig. 1:
a fragmentary, schematic representation of a fuel injector having a spherical control valve seat member which is pivotable relative to an adjusting axis of a sleeve-shaped control valve element, wherein the ball-shaped control valve seat member is supported on a component in the axial direction, the transversely displaceable relative to the adjustment axis is arranged
Fig. 2:
an alternative embodiment of a fuel injector, in which an adjustment axis of the control Valve element is arranged offset relative to an adjustment axis of the injection valve element,
3:
an enlarged view of the design and arrangement of a control valve seat member according to the Fig. 1 and 2 .
4:
an embodiment of a control valve seat, which is not part of the invention, in which a part-spherical control valve seat element is displaceably supported on a component which is stationary relative to the adjustment axis of the control valve element,
Fig. 5:
FIG. 2 shows an alternative embodiment of a control valve seat element displaceable relative to the adjustment axis of the control valve element, with an internal cone-shaped control valve seat, FIG.
Fig. 6:
an alternative embodiment of a Steuerven- tilsitzelementes with a flat seat and a ball-shaped portion for realizing a pivoting movement relative to the adjustment axis of the control valve element and
Fig. 7:
an alternative embodiment of a Steuerven- tilsitzelementes with an outer cone-shaped control valve seat.

Ausführungsformen der ErfindungEmbodiments of the invention

In den Figuren sind gleiche Bauteile und Bauteile mit der gleichen Funktion mit den gleichen Bezugszeichen gekennzeichnet.In the figures, the same components and components with the same function with the same reference numerals.

In Fig. 1 ist ein als Common-Rail-Injektor ausgebildeter Kraftstoff-Injektor 1 zum Einspritzen von Kraftstoff in einem nicht gezeigten Brennraum einer ebenfalls nicht gezeigten Brennkraftmaschine eines Kraftfahrzeugs dargestellt. Eine Hochdruckpumpe 2 fördert Kraftstoff aus einem Vorratsbehälter 3 in einen Kraftstoff-Hochdruckspeicher 4 (Rail). In diesem ist Kraftstoff, insbesondere Diesel oder Benzin, unter hohem Druck, von in diesem Ausführungsbeispiel etwa 2000 bar, gespeichert. An den Kraftstoff-Hochdruckspeicher 4 ist der Kraftstoff-Injektor 1 neben anderen, nicht gezeigten Injektoren über eine Versorgungsleitung 5 angeschlossen. Die Versorgungsleitung 5 mündet in einem Versorgungskanal 6, welcher wiederum in einen Druckraum 7 (Hochdruckbereich) des Kraftstoff-Injektors 1 mündet. Der in den Druckraum 7 einströmende Kraftstoff strömt bei einem Einspritzvorgang unmittelbar in den Brennraum der Brennkraftmaschine. Der Kraftstoff-Injektor 1 ist über einen Injektorrücklaufanschluss 8 an eine Rücklaufleitung 9 angeschlossen. Über die Rücklaufleitung 9 kann eine später noch zu erläuternde Steuermenge an Kraftstoff von dem Kraftstoff-Injektor 1 zu dem Vorratsbehälter 3 abfließen und von dort aus dem Hochdruckkreislauf wieder zugeführt werden.In Fig. 1 is a trained as a common rail injector fuel injector 1 for injecting fuel in a combustion chamber, not shown, also shown an internal combustion engine of a motor vehicle. A high pressure pump 2 delivers fuel from a reservoir 3 in a high-pressure fuel storage 4 (Rail). In this fuel, especially diesel or gasoline, under high pressure, of about 2000 bar in this embodiment, stored. To the high-pressure fuel accumulator 4, the fuel injector 1 is connected, among other injectors, not shown, via a supply line 5. The supply line 5 opens into a supply channel 6, which in turn opens into a pressure chamber 7 (high-pressure region) of the fuel injector 1. The fuel flowing into the pressure chamber 7 flows in an injection process directly into the combustion chamber of the internal combustion engine. The fuel injector 1 is connected via an injector return port 8 to a return line 9. Via the return line 9, a later to be explained control amount of fuel from the fuel injector 1 to flow to the reservoir 3 and fed from there from the high pressure circuit again.

Innerhalb eines Injektorkörpers 10 ist ein in diesem Ausführungsbeispiel einstückiges Einspritzventilelement 11, das bei Bedarf auch mehrteilig ausgeführt sein kann, in axialer Richtung verstellbar. Dabei ist das Einspritzventilelement 11 innerhalb eines axial zum Injektorkörper 10 benachbarten Düsenkörpers 12 an seinem Außenumfang geführt. Dieser nur ausschnittsweise dargestellte Düsenkörper 12 ist mittels einer nicht dargestellten Überwurfmutter mit dem Injektorkörper 10 verspannt.Within an injector body 10 is a one-piece in this embodiment injection valve element 11, which may be designed in several parts if necessary, adjustable in the axial direction. In this case, the injection valve element 11 is guided within an axially adjacent to the injector body 10 nozzle body 12 at its outer periphery. This only partially shown nozzle body 12 is clamped by means of a union nut, not shown, with the injector body 10.

Das Einspritzventilelement 11 weist an seiner Spitze 13 eine Schließfläche 14 (Dichtfläche) auf, mit welcher das Einspritzventilelement 11 in eine dichte Anlage an einen innerhalb des Düsenkörpers 12 ausgebildeten Einspitzventilelementsitz 15 anbringbar ist. Wenn das Einspritzventilelement 11 an seinem Einspritzventilelementsitz 15 anliegt, d.h. sich in einer Schließstellung befindet, ist der Kraftstoffaustritt aus einer Düsenlochanordnung 16 gesperrt. Ist es dagegen von seinem Einspritzventilelementsitz 15 abgehoben, kann Kraftstoff aus dem Druckraum 7 durch in einen Führungsabschnitt 17 am Außenumfang des Einspritzventilelementes 11 durch Anschlüsse gebildete Axialkanäle 18 in einen in der Zeichnungsebene unteren, radial zwischen dem Einspritzventilelement 11 und dem Düsenkörper 12 ausgebildeten Ringraum 19 an dem Einspritzventilelement 11 vorbei zur Düsenlochanordnung 16 strömen und dort im Wesentlichen unter Hochdruck (Rail-Druck) stehend in den Brennraum gespritzt werden.The injection valve element 11 has at its tip 13 a closing surface 14 (sealing surface) with which the injection valve element 11 can be attached in a tight contact with a single point valve element seat 15 formed inside the nozzle body 12. When the injection valve member 11 abuts against its injection valve member seat 15, i. is in a closed position, the fuel outlet from a nozzle hole arrangement 16 is locked. If, on the other hand, it is lifted from its injection valve element seat 15, fuel can flow from the pressure chamber 7 through axial passages 18 formed in a guide section 17 on the outer circumference of the injection valve element 11 into a lower annular space 19 formed radially between the injection valve element 11 and the nozzle body 12 in the drawing plane the injection valve element 11 to flow past the nozzle hole assembly 16 and there are injected substantially under high pressure (rail pressure) standing in the combustion chamber.

Von einer oberen Stirnseite 20 des Einspritzventilelementes 11 und einem in der Zeichnungsebene unteren, hülsenförmigen Abschnitt 21 einer Drosselplatte 22 wird eine Steuerkammer 23 begrenzt, die über eine radial in dem hülsenförmigen Abschnitt der Drosselplatte 22 verlaufende Zulaufdrossel 24 mit unter Hochdruck stehendem Kraftstoff aus dem Druckraum 7 versorgt wird. Der hülsenförmige Abschnitt 21 mit darin eingeschlossener Steuerkammer 23 ist radial außen von unter Hochdruck stehendem Kraftstoff umschlossen, so dass ein ringförmiger Führungsspalt 25 radial zwischen dem hülsenförmigen Abschnitt 21 und dem Einspritzventilelement 11 vergleichsweise kraftstoffdicht ist. Zur Erhöhung der Kraftstoff-Dichtheit des Führungsspaltes 25 sind zwei in axialer Richtung beabstandete Ringnuten 26 am Außenumfang des Einspritzventilelementes 11 innerhalb des hülsenförmigen Abschnittes 21 vorgesehen.From an upper end face 20 of the injection valve element 11 and a lower in the plane of the sleeve-shaped portion 21 of a throttle plate 22, a control chamber 23 is limited, via a radially extending in the sleeve-shaped portion of the throttle plate 22 inlet throttle 24 under high pressure fuel from the pressure chamber. 7 is supplied. The sleeve-shaped section 21 with the control chamber 23 enclosed therein is enclosed radially on the outside by high-pressure fuel, so that an annular guide gap 25 is comparatively fuel-tight radially between the sleeve-shaped section 21 and the injection valve element 11. To increase the fuel-tightness of the guide gap 25 are two in axially spaced annular grooves 26 provided on the outer circumference of the injection valve element 11 within the sleeve-shaped portion 21.

Die Steuerkammer 23 ist über einen eine Ablaufdrossel 28 aufweisenden Ablaufkanal 27 mit einer Ventilkammer 29 verbunden. Die Ventilkammer 29 ist radial außen von einem hülsenförmigen Steuerventilelement 31 umgeben, das axial entlang einer Verstellachse 30 verstellbar ist. Dabei fluchtet die Verstellachse 30 des Steuerventilelementes 31 mit einer im Kraftstoff-Injektor 1 zentrischen Verstellachse des Einspritzventilelementes 11. Das hülsenförmige Steuerventilelement 31 ist Bestandteil eines in axialer Richtung druckausgeglichenen Steuerventils 32 (Servoventil). Aus der Ventilkammer 29 kann Kraftstoff in einen Niederdruckbereich 33 des Kraftstoff-Injektors 1 und von dort aus zu dem Injektorrücklaufanschluss 8 strömen, wenn das hülsenförmige Steuerventilelement 31, das in dem gezeigten Ausführungsbeispiel einstückig mit einer Ankerplatte 34 ausgebildet ist, von seinem kugelförmigen Steuerventilsitz 35 abgehoben, d.h. das Steuerventil 32 geöffnet ist. Zum Öffnen des Steuerventils 32 muss das hülsenförmige Steuerventilelement 31 in der Zeichnungsebene nach unten in Richtung auf das Einspritzventilelement 11 zu verstellt werden. Hierzu ist ein elektromagnetischer Aktuator 36 mit einem Elektromagnet 37 (Spule) vorgesehen, der mit der Ankerplatte 34 und in der Folge mit dem Steuerventilelement 31 bei entsprechender Bestromung zusammenwirkt. Der Aktuator 36, genauer der Elektromagnet 37, ist axial zwischen der Ankerplatte 34 und der Drosselplatte 22 angeordnet. Bei einer Bestromung des Aktuators 36 wird das hülsenförmige Steuerventilelement 31 in axialer Richtung in der Zeichnungsebene nach unten entlang der Verstellachse 30 in Richtung auf dem Einspritzventilelementsitz 15 zu verstellt und hebt dabei von seinem Steuerventilsitz 35 ab. Die Durchflussquerschnitte der Zulaufdrossel 24 und der Ablaufdrossel 28 sind dabei derart aufeinander abgestimmt, dass bei geöffnetem Steuerventil 32 ein Nettoabfluss von Kraftstoff (Kraftstoffsteuermenge) aus der Steuerkammer 23 über die Ventilkammer 29 in den Niederdruckbereich 33 des Kraftstoff-Injektors 1 und von dort aus über den Injektorrücklaufanschluss 8 und die Rücklaufleitung 9 in den Vorratsbehälter 3 resultiert. Hierdurch sinkt der Druck der Steuerkammer 23 rapide ab, wodurch das Einspritzventilelement 11 von seinem Einspritzventilelementsitz 15 abhebt, wodurch in der Folge Kraftstoff aus dem Druckraum 7 durch die Düsenlochanordnung 16 in den Brennraum ausströmen kann.The control chamber 23 is connected via a flow restrictor 28 having a drain passage 27 with a valve chamber 29. The valve chamber 29 is surrounded radially on the outside by a sleeve-shaped control valve element 31 which is axially adjustable along an adjustment axis 30. In this case, the adjustment axis 30 of the control valve element 31 is aligned with a central axis in the fuel injector 1 adjustment axis of the injection valve element 11. The sleeve-shaped control valve element 31 is part of a pressure-balanced in the axial direction of the control valve 32 (servo valve). From the valve chamber 29, fuel can flow into a low-pressure region 33 of the fuel injector 1 and from there to the injector return port 8, when the sleeve-shaped control valve element 31, which is formed integrally with an anchor plate 34 in the embodiment shown, lifted from its spherical control valve seat 35 , ie the control valve 32 is open. To open the control valve 32, the sleeve-shaped control valve element 31 must be adjusted in the drawing plane downwards in the direction of the injection valve element 11. For this purpose, an electromagnetic actuator 36 with an electromagnet 37 (coil) is provided, which cooperates with the armature plate 34 and in sequence with the control valve element 31 with appropriate energization. The actuator 36, more specifically the solenoid 37, is disposed axially between the armature plate 34 and the throttle plate 22. When energizing the actuator 36, the sleeve-shaped control valve element 31 in the axial direction in the plane of the drawing down along the adjustment axis 30 in the direction of the injection valve element seat 15 to adjusted and lifts it from its control valve seat 35 from. The flow cross sections of the inlet throttle 24 and the outlet throttle 28 are matched to one another such that when open control valve 32, a net outflow of fuel (fuel control amount) from the control chamber 23 via the valve chamber 29 in the low pressure region 33 of the fuel injector 1 and from there via the Injector return port 8 and the return line 9 results in the reservoir 3. As a result, the pressure of the control chamber 23 decreases rapidly, whereby the injection valve element 11 lifts from its injection valve element seat 15, whereby fuel in the sequence from the pressure chamber 7 through the nozzle hole assembly 16 can flow into the combustion chamber.

Zum Beenden des Einspritzvorgangs wird die Bestromung des elektromagnetischen Aktuators 36 unterbrochen, wodurch das hülsenförmige Steuerventilelement 31 mittels einer Steuerfeder 38, die sich an der Ankerplatte 34 und an einem Ringelement 39, das auf der Drosselplatte 22 anliegt, abstützt, in der Zeichnungsebene nach oben auf ihren Steuerventilsitz 35 verstellt wird. Der durch die Zulaufdrossel 24 in die Steuerkammer 23 nachströmende Kraftstoff sorgt für eine schnelle Druckerhöhung in der Steuerkammer 23 und damit für eine auf das Einspritzventilelement 11 wirkende Schließkraft. Diese führt dazu, dass das Einspritzventilelement 11 in der Zeichnungsebene nach unten auf den Einspritzventilelementsitz 15 bewegt wird, wodurch der Einspritzvorgang beendet wird.To stop the injection process, the energization of the electromagnetic actuator 36 is interrupted, whereby the sleeve-shaped control valve member 31 by means of a control spring 38, which is supported on the anchor plate 34 and on a ring member 39 which rests on the throttle plate 22, in the plane of the drawing up its control valve seat 35 is adjusted. The fuel flowing in through the inlet throttle 24 into the control chamber 23 ensures rapid pressure increase in the control chamber 23 and thus a closing force acting on the injection valve element 11. This results in that the injection valve element 11 is moved in the drawing plane down to the injection valve element seat 15, whereby the injection process is terminated.

Einstückig mit der Drosselplatte 22 ist ein Führungsfortsatz 40 ausgebildet, welcher in axialer Richtung nach oben ragt. Der Ablaufkanal 27 aus der Steuerkammer 23 durchsetzt diesen Führungsfortsatz 40, in dem auch die Ablaufdrossel 28 angeordnet ist, zentrisch. Der Führungsfortsatz 40 erstreckt sich in das hülsenförmige Steuerventilelement 31 hinein und dient zu dessen Führung bei einer Verstellbewegung entlang der Verstellachse 30.Integral with the throttle plate 22, a guide extension 40 is formed, which projects in the axial direction upwards. The drain passage 27 from the control chamber 23 passes through this guide extension 40, in which the outlet throttle 28 is arranged, centric. The guide extension 40 extends into the sleeve-shaped control valve element 31 and serves to guide it during an adjustment movement along the adjustment axis 30.

Der Steuerventilsitz 35 wird von einem Steuerventilsitzelement 41 gebildet, das in dem gezeigten Ausführungsbeispiel als Kugel ausgebildet ist. Das kugelförmige Steuerventilsitzelement 41 stützt sich in axialer Richtung an einem Bauteil 42 ab, welches sich wiederum lose an einer Platte 43 abstützt, die wiederum in axialer Richtung lose an einem Schraubeinsatz 44 anliegt. Das Bauteil 42 weist dabei einen kalottenförmigen Abschnitt 45 auf. Dieser ist als teilkugelförmige Ausnehmung ausgebildet, wobei die teilkugelförmige Ausnehmung einen größeren Krümmungsradius aufweist, als der Krümmungsradius des kugelförmigen Steuerventilsitzelementes 41, um zu Ausrichtungszwecken ein Abrollen des Steuerventilsitzelementes 41 innerhalb des Abschnittes 45, d.h. innerhalb der Ausnehmung, relativ zur Verstellachse 30, zu ermöglichen.The control valve seat 35 is formed by a control valve seat member 41, which is formed in the embodiment shown as a ball. The spherical control valve seat element 41 is supported in the axial direction on a component 42, which in turn is loosely supported on a plate 43, which in turn rests in the axial direction loosely on a threaded insert 44. The component 42 has a dome-shaped portion 45. This is formed as a part-spherical recess, wherein the part-spherical recess has a larger radius of curvature than the radius of curvature of the spherical control valve seat member 41, for alignment purposes, a rolling of the control valve seat member 41 within the section 45, i. within the recess, relative to the adjustment axis 30, to allow.

Der Durchmesser der Platte 43 entspricht in etwa dem Durchmesser einer Bohrung 46 in einem Ventilelement 47, mit dem der Schraubeinsatz 44 verschraubt ist. Hierdurch ist keine seitliche Verstellung der Platte 43 innerhalb der Bohrung 46 möglich. Der Durchmesser des axial unmittelbar benachbart zu der Platte 43 angeordneten Bauteils 42 ist etwas geringer bemessen als der Durchmesser der Bohrung 46, so dass das Bauteil 42 mit seinem kalottenförmigen Abschnitt 45 relativ zur Verstellachse 30, und zwar senkrecht zu dieser, verschiebbar ist. Das Steuerventilsitzelement 41 wiederum kann innerhalb des Abschnittes 45 des Bauteils 42 abrollen. Durch die abrollbare Anordnung des Steuerventilsitzelementes 41 relativ zur Verstellachse 30 des Steuerventilelementes 31 können somit Winkelfehler zwischen dem Steuerventilelement 31 und dem Steuerventilsitzelement 41 mit seinem Steuerventilsitz 35 ausgeglichen werden. Durch die verschiebbare Anordnung des axial unmittelbar zu dem Steuerventilsitz 41 benachbarten Bauteils 42 quer zur Verstellachse 30 zusammen mit dem Steuerventilsitzelement 41 können zusätzlich Koaxialfehler zwischen dem Steuerventilsitzelement 41 und dem Steuerventilelement 31 ausgeglichen werden.The diameter of the plate 43 corresponds approximately to the diameter of a bore 46 in a valve element 47, with which the threaded insert 44 is screwed. As a result, no lateral adjustment of the plate 43 within the bore 46 is possible. The diameter of the axially immediately adjacent to the plate 43 disposed member 42 is dimensioned slightly smaller than the diameter of the bore 46, so that the component 42 with its dome-shaped portion 45 relative to the adjustment axis 30, namely perpendicular to this, is displaceable. The control valve seat member 41 in turn can roll within the portion 45 of the component 42. As a result of the unrollable arrangement of the control valve seat element 41 relative to the adjustment axis 30 of the control valve element 31, angle errors between the control valve element 31 and the control valve seat element 41 with its control valve seat 35 can thus be compensated. Due to the displaceable arrangement of the axially adjacent to the control valve seat 41 member 42 transverse to the adjustment axis 30 together with the control valve seat member 41 in addition coaxial errors between the control valve seat member 41 and the control valve member 31 can be compensated.

Bei der gezeigten Ausführungsform liegen sowohl das Steuerventilsitzelement 41, als auch das Bauteil 42 als auch die Platte 44 lose (axial verstellbar) innerhalb der Bohrung 46 eines Ventilelementes 47. Das Steuerventilsitzelement 41 wird im Betrieb von dem innerhalb des Ablaufkanals 27 befindlichen, unter hohem Druck stehenden Kraftstoff in axialer Richtung nach oben unmittelbar gegen das Bauteil 42 gedrückt, wodurch dieses wiederum unmittelbar in der Zeichnungsebene nach oben gegen die Platte 43 gedrückt wird, welche wiederum gegen den Schraubeinsatz 44 kraftbeaufschlagt wird.In the embodiment shown, both the control valve seat member 41, and the member 42 and the plate 44 are loose (axially adjustable) within the bore 46 of a valve member 47. The control valve seat member 41 is in operation of the located within the drain passage 27, under high pressure standing fuel in the axial direction upwards pressed directly against the component 42, whereby this in turn is pressed directly in the plane of the drawing up against the plate 43, which in turn is subjected to force against the threaded insert 44.

Wie sich in Fig. 1 ergibt, ist das Ventilelement 47 mit dem Injektorkörper 10 verschraubt und verspannt den Aktuator 36 gegen die Drosselplatte 22, welcher sich in axialer Richtung an einer inneren Ringschulter 48 des Injektorkörpers 10 abstützt.As is in Fig. 1 results, the valve member 47 is screwed to the injector body 10 and clamps the actuator 36 against the throttle plate 22, which is supported in the axial direction on an inner annular shoulder 48 of the injector body 10.

Eine stirnseitige Dichtfläche 49 (Ringlinie), mit der sich das Steuerventilelement 31 an dem Steuerventilsitzelement 41 abstützt, ist innenkegelförmig ausgebildet, wobei eine nicht eingezeichnete, von der Dichtfläche 49 gebildete Dichtlinie zumindest näherungsweise den gleichen Durchmesser aufweist, wie der Führungsfortsatz 40 um somit eine Druckausgeglichenheit des Steuerventils 32 zu realisieren.An end-face sealing surface 49 (ring line), with which the control valve member 31 is supported on the control valve seat member 41, is formed inside a conical shape, wherein a not shown, formed by the sealing surface 49 sealing line at least approximately the same diameter, as the guide extension 40 so as to realize a pressure balance of the control valve 32.

In Fig. 2 ist ein alternatives Ausführungsbeispiel eines Kraftstoff-Injektors 1 gezeigt. Die Funktionsweise des Kraftstoff-Injektors 1 gemäß Fig. 2 entspricht im Wesentlichen der Funktionsweise des Kraftstoff-Injektors 1 gemäß Fig. 1, so dass zur Vermeidung von Wiederholungen im Folgenden im Wesentlichen die Unterschiede zu dem zuvor beschriebenen Kraftstoff-Injektor 1 dargelegt werden. Im Hinblick auf die Gemeinsamkeiten wird auf die vorhergehende Figurenbeschreibung sowie auf Fig. 1 verwiesen.In Fig. 2 an alternative embodiment of a fuel injector 1 is shown. The operation of the fuel injector 1 according to Fig. 2 corresponds substantially to the operation of the fuel injector 1 according to Fig. 1 , so that in order to avoid repetition in the following essentially the differences to the fuel injector 1 described above are set forth. With regard to the similarities is on the previous figure description as well as on Fig. 1 directed.

In Fig. 2 ist zu erkennen, dass die Verstellachse 30 des hülsenförmigen Steuerventilelementes 31 radial zu einer Einspritzventilelementverstellachse 50 versetzt angeordnet ist. Die in dem Druckraum 7 angeordnete Steuerkammer 23 wird radial außen von einem Hülsenbauteil 51 begrenzt, das sich in axialer Richtung an einer Drosselplatte 22 abstützt. Diese Drosselplatte 22 weist zusätzlich zu der Ablaufdrossel 28 die Zulaufdrossel 24 zur Versorgung der Steuerkammer 23 auf, wobei die Zulaufdrossel 24 alternativ auch als Radialkanal in dem Hülsenbauteil 51 angeordnet werden kann. Das Hülsenbauteil 51 wird mit Hilfe einer Schließfeder 52 in axialer Richtung in der Zeichnungsebene nach oben gegen die Drosselplatte 22 gepresst, wobei sich die Schließfeder 52 in axialer Richtung an einem Umfangsbund 53 des einstückigen Einspritzventilelementes 11 abstützt. Die Schließfeder 52 unterstützt dabei die Schließbewegung des Einspritzventilelementes 11.In Fig. 2 It can be seen that the adjustment axis 30 of the sleeve-shaped control valve element 31 is arranged offset radially to an injection valve element adjustment axis 50. The arranged in the pressure chamber 7 control chamber 23 is bounded radially outwardly by a sleeve member 51 which is supported in the axial direction of a throttle plate 22. This throttle plate 22 has, in addition to the outlet throttle 28, the inlet throttle 24 for supplying the control chamber 23, wherein the inlet throttle 24 may alternatively be arranged as a radial passage in the sleeve member 51. The sleeve member 51 is pressed by means of a closing spring 52 in the axial direction in the drawing plane up against the throttle plate 22, wherein the closing spring 52 is supported in the axial direction on a peripheral collar 53 of the one-piece injection valve element 11. The closing spring 52 supports the closing movement of the injection valve element 11.

Unmittelbar an der Drosselplatte 22 liegt axial eine Bodenplatte 54 an, innerhalb der sich der Ablaufkanal 27 in der Zeichnungsebene nach oben fortsetzt. Einstückig mit der Bodenplatte 54 ist der Führungsfortsatz 40 ausgebildet, der zur Führung des hülsenförmigen Steuerventilelementes 31 bei seiner Axialbewegung dient. Alternativ kann die Bodenplatte 54 auch als rotationssymmetrisches Bauteil ausgebildet werden, wobei dann die Verstellachse 30 des Steuerventilelementes 31 in axialer Richtung mit der Einspritzventilelementverstellachse 50 fluchtet.Immediately on the throttle plate 22 is located axially on a bottom plate 54, within which the drain passage 27 continues in the plane of the drawing upwards. Integral with the bottom plate 54 of the guide extension 40 is formed, which serves to guide the sleeve-shaped control valve member 31 during its axial movement. Alternatively, the bottom plate 54 may be formed as a rotationally symmetrical component, in which case the adjustment axis 30 of the control valve element 31 is aligned in the axial direction with the Einspritzventilelementverstellachse 50.

Axial an die Bodenplatte 54 grenzt ein weiteres Plattenelement 55 unmittelbar an, das in einer Bohrung 56 den seitlich zur Längsmittelachse des Kraftstoff-Injektors 1 versetzten Aktuator 36 mit dem Elektromagnet 37 trägt. Ein endseitiger Düsenkörper 12 ist mittels einer Überwurfmutter 57 mit dem Injektorkörper 10 verschraubt, wobei mit Hilfe der Überwurfmutter 57 die Injektorbauteile gegeneinander verspannt werden. Zu erkennen ist weiterhin, dass sich der Versorgungskanal 6 in axialer Richtung durch den Injektorkörper 10, durch das Plattenelement 55 und die Bodenplatte 54 bis zum Druckraum 7 fortsetzt.Axially to the bottom plate 54 adjacent to another plate member 55 which carries in a bore 56 the laterally offset to the longitudinal center axis of the fuel injector 1 actuator 36 with the electromagnet 37. An end nozzle body 12 is screwed by means of a union nut 57 with the injector body 10, wherein the injector components are braced against each other with the aid of the union nut 57. It can also be seen that the supply channel 6 continues in the axial direction through the injector body 10, through the plate element 55 and the bottom plate 54 to the pressure chamber 7.

Wie sich aus Fig. 2 weiter ergibt, stützt sich das Einspritzventilelement 31 in axialer Richtung in der Zeichnungsebene nach oben an einem als Kugel ausgebildeten Steuerventilsitzelement 41 ab, welches relativ zur Verstellachse 30 innerhalb eines kalottenförmigen Abschnittes 45 eines axial benachbarten Bauteils 42 abrollbar ist. Das Bauteil 42 wiederum ist zusammen mit dem Steuerventilsitzelement 41 quer zur Verstellachse 30 des Steuerventilelementes 31 verschiebbar innerhalb einer Bohrung 46 im Injektorkörper 10 aufgenommen.As it turned out Fig. 2 results further, the injection valve member 31 is supported in the axial direction in the plane upwards on a designed as a ball control valve seat member 41 which is relatively unrolled relative to the adjustment axis 30 within a dome-shaped portion 45 of an axially adjacent component 42. The component 42, in turn, together with the control valve seat element 41 is received transversely to the adjustment axis 30 of the control valve element 31 displaceable within a bore 46 in the injector body 10.

Im Folgenden werden anhand der Fig. 3 bis 7 unterschiedliche Anordnungen und Ausbildungen des Steuerventilsitzelementes 41 und der mit diesem zusammenwirkenden Bauteile beschrieben, wobei die Ausführungen unabhängig von der konkreten Kraftstoff-Injektorbauform (vgl. z.B. Fig. 1 oder Fig. 2) realisiert werden können.The following are based on the Fig. 3 to 7 described different arrangements and configurations of the control valve seat member 41 and the cooperating with this components, the embodiments regardless of the specific fuel injector design (see, eg Fig. 1 or Fig. 2 ) can be realized.

In Fig. 3 ist eine vergrößerte Variante des in den Fig. 1 und 2 realisierten Steuerventilsitzelementes 41 gezeigt. Dieses ist als Kugel ausgeformt. Zu erkennen ist, dass der Durchmesser DD einer stirnseitig am Steuerventilsitzelement 41 ausgebildeten Dichtfläche (Dichtlinie) dem Führungsdurchmesser DF entspricht, an dem das Steuerventilelement 31 am Führungsfortsatz 40 geführt ist. Zu erkennen ist weiterhin, dass der Krümmungsradius des kugelförmigen Steuerventilsitzelementes 41 geringer ist als der Krümmungsradius der teilkugelförmigen Ausnehmung, die den kalottenförmigen Abschnitt 45 des relativ zur Verstellachse 30 verschiebbar angeordneten Bauteils 42 bildet.In Fig. 3 is an enlarged version of the in the Fig. 1 and 2 realized control valve seat member 41 shown. This is shaped as a ball. It can be seen that the diameter D D of a front face on the control valve seat member 41 formed sealing surface (sealing line) corresponds to the guide diameter D F , at which the control valve element 31 is guided on the guide extension 40. It can also be seen that the radius of curvature of the spherical control valve seat element 41 is less than the radius of curvature of the part-spherical recess which forms the dome-shaped portion 45 of the component 42 displaceably arranged relative to the adjustment axis 30.

In Fig. 4 ist das Steuerventilsitzelement 41 zumindest näherungsweise halbkugelförmig ausgebildet, wobei sich das Steuerventilsitzelement 41 mit einem Flachabschnitt 59 an einem Bauteil 42 abstützt, welches ortsfest relativ zur Verstellachse 30 angeordnet ist. Das Steuerventilsitzelement 41 ist relativ zur Verstellachse 30 entlang des Bauteils 42 verschiebbar angeordnet, so dass Koaxialfehler ausgeglichen werden können. Der Durchmesser DD der Dichtfläche (Dichtlinie) entspricht auch in dem gezeigten Ausführungsbeispiel dem Führungsdurchmesser DF. Wie sich weiterhin aus Fig. 4 ergibt, ist der Steuerventilsitz 35 teilkugelförmig ausgeformt.In Fig. 4 the control valve seat member 41 is formed at least approximately hemispherical, wherein the control valve seat member 41 is supported with a flat portion 59 on a component 42 which is stationary relative to the adjustment axis 30 is arranged. The control valve seat member 41 is slidably disposed relative to the adjustment axis 30 along the component 42, so that coaxial errors can be compensated. The diameter D D of the sealing surface (seal line) also corresponds in the embodiment shown, the guide diameter D F. How to continue Fig. 4 results, the control valve seat 35 is formed partially spherical.

In Fig. 5 ist ein alternatives Ausführungsbeispiel gezeigt, wobei der Steuerventilsitz 35 als innenkonusförmiger Innenkegel ausgeformt ist. Dabei ist der Kegelwinkel des Steuerventilsitzes 35 größer ist als der Kegelwinkel des stirnseitig an dem Steuerventilelement 31 ausgebildeten Kegels. Wie sich aus Fig. 1 ergibt, ist das Steuerventilsitzelement 41 quer zur Verstellachse 30, d.h. relativ zu dieser, entlang des Bauteils 42 verschiebbar angeordnet, wodurch Koaxialfehler ausgeglichen werden können.In Fig. 5 an alternative embodiment is shown, wherein the control valve seat 35 is formed as an inner cone-shaped inner cone. The cone angle of the control valve seat 35 is greater than the cone angle of the front side formed on the control valve element 31 cone. As it turned out Fig. 1 results, the control valve seat member 41 is transverse to the adjustment axis 30, that is, relative to this, slidably disposed along the component 42, whereby coaxial errors can be compensated.

In Fig. 6 ist wiederum ein teilkugelförmiges, zumindest näherungsweise halbkugelförmiges, Steuerventilsitzelement 41 vorgesehen, wobei bei dem gezeigten Ausführungsbeispiel ein Flachabschnitt 59 des Steuerventilsitzelementes 41 den als Flachsitz ausgebildeten Steuerventilsitz 35 bildet. Mit einem teilkugelförmigen Abschnitt 60 ist das Steuerventilsitzelement 41 in einer innenkegelförmigen Ausnehmung 61 des Bauteils 42 aufgenommen. Mit der gezeigten Ausführungsvariante sind ausschließlich Winkelfehler korrigierbar, für den Fall, dass das Bauteil 42 ortsfest zur Verstellachse 30 angeordnet ist. Für den Fall, dass das Bauteil 42 relativ zur Verstellachse 30 verschiebbar angeordnet ist, können zusätzlich Koaxialfehler des Steuerventilelementes 31 relativ zu dem als Flachsitz ausgebildeten Steuerventilsitz 35 ausgeglichen werden.In Fig. 6 in turn, a part-spherical, at least approximately hemispherical, control valve seat member 41 is provided, wherein in the embodiment shown, a flat portion 59 of the control valve seat member 41 forms the formed as a flat seat control valve seat 35. With a part-spherical section 60, the control valve seat element 41 is received in an internal conical recess 61 of the component 42. With the embodiment shown only angle errors can be corrected, in the event that the component 42 is arranged stationary to the adjustment axis 30. In the event that the component 42 is arranged to be displaceable relative to the adjustment axis 30, in addition coaxial errors of the control valve element 31 can be compensated relative to the control valve seat 35 formed as a flat seat.

Bei dem Ausführungsbeispiel gemäß Fig. 7 weist das quer zur Verstellachse 30 verstellbare Steuerventilsitzelement 41 einen als Außenkegel ausgebildeten Steuerventilsitz 35 auf. Auch hier entspricht der Durchmesser DD der ringförmigen Dichtfläche (Dichtlinie) zumindest näherungsweise dem Führungsdurchmesser DF, so dass ein in axialer Richtung druckausgeglichenes Steuerventil erhalten wird.In the embodiment according to Fig. 7 The control valve seat element 41, which can be adjusted transversely to the adjustment axis 30, has a control valve seat 35 designed as an outer cone. Again, the diameter D D of the annular sealing surface (sealing line) at least approximately corresponds to the guide diameter D F , so that a pressure-balanced in the axial direction control valve is obtained.

Claims (8)

  1. Fuel injector, in particular common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine, with an injection valve element (11) which can be adjusted between a closed position and an open position and can be switched by means of a control valve (32), wherein the control valve (32) has a sleeve-shaped control valve element (31) which can be adjusted along an adjustment axis (30) and, in the closed position thereof, bears in a sealing manner against a control valve seat element (41), wherein the control valve seat element (41) is arranged movably relative to the adjustment axis (30) of the control valve element (31), characterized in that the control valve seat element (41) is supported on a component (42) which is movable, in particular displaceable, relative to the adjustment axis (30), and is movable, in particular pivotable and/or rollable, relative to said component (42).
  2. Fuel injector according to Claim 1, characterized in that the control valve element (31) is at least approximately pressure-equalized in the axial direction in the closed position thereof.
  3. Fuel injector according to either of Claims 1 and 2, characterized in that the control valve seat element (41) is arranged displaceably and/or pivotably and/or rollably, in particular transversely with respect to the adjustment axis (30).
  4. Fuel injector according to one of the preceding claims, characterized in that the control valve seat element (41) has at least one partially spherical portion (60), or is designed as a ball.
  5. Fuel injector according to one of the preceding claims, characterized in that the control valve seat element (41) has a control valve seat (35) which is partially spherical or is in the form of a female taper, or a control valve seat (35) which is in the form of a male taper, or a control valve seat (35) which is designed as a flat seat.
  6. Fuel injector according to one of the preceding claims, characterized in that the control valve (32) is arranged in such a manner that the opening control valve element (31) moves in the direction of an injection valve element seat (15).
  7. Fuel injector according to one of the preceding claims, characterized in that the adjustment axis (30) of the control valve element (31) is arranged offset laterally with respect to a movement axis of the injection valve element (11).
  8. Fuel injector according to one of the preceding claims, characterized in that an outlet throttle (28) assigned to a control chamber (23) and/or an inlet throttle (24) assigned to the control chamber (23) are/is arranged in a throttle plate (22) which is designed as a component which is separate from a base plate (54) which has a guide rod portion for the control valve element (31).
EP09100169A 2008-05-06 2009-03-06 Fuel injector Expired - Fee Related EP2116717B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102008001597A DE102008001597A1 (en) 2008-05-06 2008-05-06 Fuel injector

Publications (3)

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EP2116717A2 EP2116717A2 (en) 2009-11-11
EP2116717A3 EP2116717A3 (en) 2009-12-02
EP2116717B1 true EP2116717B1 (en) 2011-09-28

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP09100169A Expired - Fee Related EP2116717B1 (en) 2008-05-06 2009-03-06 Fuel injector

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US (1) US7987835B2 (en)
EP (1) EP2116717B1 (en)
DE (1) DE102008001597A1 (en)

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DE102010030429A1 (en) 2010-06-23 2011-12-29 Robert Bosch Gmbh Injector i.e. common-rail injector, for injecting fuel into combustion chamber of internal combustion engine, has seat surface whose sealing seat is formed at armature, and valve element formed in ball shape
DE102010039191A1 (en) 2010-08-11 2012-02-16 Robert Bosch Gmbh Fuel injector, particularly common-rail-injector, for injecting fuel in combustion chamber of internal combustion engine, has injection valve element that is adjustable between closing position and open position
DE102010043092A1 (en) * 2010-10-29 2012-05-03 Robert Bosch Gmbh Pressure control valve
DE102012208075A1 (en) * 2012-05-15 2013-11-21 Man Diesel & Turbo Se Injector for a fuel supply system of an internal combustion engine and fuel supply system
SE536494C2 (en) * 2012-05-16 2013-12-27 Scania Cv Ab Valve for a fuel system for an internal combustion engine and a method for controlling a fuel system for an internal combustion engine
US9212639B2 (en) * 2012-11-02 2015-12-15 Caterpillar Inc. Debris robust fuel injector with co-axial control valve members and fuel system using same
CN106321307B (en) * 2015-07-03 2020-03-06 罗伯特·博世有限公司 Fuel injector and control valve therefor
DE102015223442A1 (en) 2015-11-26 2017-06-01 Robert Bosch Gmbh fuel injector
US11415094B2 (en) 2019-04-30 2022-08-16 Delphi Technologies Ip Limited Fuel pressure regulator

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Also Published As

Publication number Publication date
US7987835B2 (en) 2011-08-02
EP2116717A3 (en) 2009-12-02
EP2116717A2 (en) 2009-11-11
DE102008001597A1 (en) 2009-11-12
US20090277421A1 (en) 2009-11-12

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