EP2949918B1 - Fuel injector - Google Patents

Fuel injector Download PDF

Info

Publication number
EP2949918B1
EP2949918B1 EP15163483.9A EP15163483A EP2949918B1 EP 2949918 B1 EP2949918 B1 EP 2949918B1 EP 15163483 A EP15163483 A EP 15163483A EP 2949918 B1 EP2949918 B1 EP 2949918B1
Authority
EP
European Patent Office
Prior art keywords
coupler
nozzle
actuator
fuel injector
volume
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.)
Not-in-force
Application number
EP15163483.9A
Other languages
German (de)
French (fr)
Other versions
EP2949918A1 (en
Inventor
Andreas Gruenberger
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 EP2949918A1 publication Critical patent/EP2949918A1/en
Application granted granted Critical
Publication of EP2949918B1 publication Critical patent/EP2949918B1/en
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
    • F02M51/0603—Injectors peculiar thereto with means directly operating the valve needle using piezoelectric or magnetostrictive 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/167—Means for compensating clearance or thermal expansion
    • 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
    • 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
    • F02M2200/708—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic with hydraulic chambers formed by a movable sleeve

Definitions

  • the invention relates to a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine having the features of the preamble of claim 1.
  • a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine which has for releasing and closing at least one injection port in a high-pressure bore of a nozzle body liftably received nozzle needle and a piezoelectric actuator for controlling the lifting movement of the nozzle needle.
  • the piezoactuator is hydraulically coupled to the nozzle needle and actuates a master piston which acts as a displacer in a coupling space, while the nozzle needle is coupled in a coupled manner to a slave piston which displaces the coupling space in the coupling space.
  • the piezoelectric actuator and the master piston on the one hand and the nozzle needle and the slave piston on the other hand have different lifting axes, these lifting axes are arranged parallel to each other and laterally offset.
  • the direction of action of the piezoelectric actuator corresponds to the direction of movement of the nozzle needle, so that the activation of the piezoelectric actuator generates a closing force acting on the nozzle needle.
  • fuel injectors with so-called “reversing couplers” are known, which allow a reversal of the effective direction of the piezoelectric actuator, so that the activation of the piezoelectric actuator takes place for opening the nozzle needle.
  • a fuel injector is an example of the published patent application DE 10 2011 003 443 A1 out. at Activation lasts the piezoelectric actuator and moves the master piston against the spring force of a biasing spring in the direction of the nozzle needle, so that the pressure rises in a first coupler space.
  • the first coupler space communicates with a further coupler space, which is arranged below a coupler piston connected to the nozzle needle, so that the increase in pressure caused in the further coupler space leads to the lifting of the nozzle needle from its sealing seat.
  • a further coupler space which is arranged below a coupler piston connected to the nozzle needle, so that the increase in pressure caused in the further coupler space leads to the lifting of the nozzle needle from its sealing seat.
  • the piezoelectric actuator is terminated, which then contracts again, the spring force of the biasing spring leads to the return of the master piston.
  • the two coupler spaces are relieved, while in a further coupler volume acting on the nozzle needle closing pressure is built up, so that in the sequence and the nozzle needle is returned to its sealing seat.
  • the present invention has for its object to simplify the structure of a fuel injector with eccentrically arranged piezoelectric actuator and reversing coupler.
  • the fuel injector proposed for injecting fuel into a combustion chamber of an internal combustion engine comprises a nozzle body and a nozzle needle which is liftably received for releasing and closing at least one injection opening in a high-pressure bore of the nozzle body and acted upon in the direction of a sealing seat by the spring force of a nozzle spring. Furthermore, the fuel injector comprises a piezoelectric actuator, which is hydraulically coupled to control the lifting movement of the nozzle needle via a coupling device with the nozzle needle.
  • the coupling device compensates for an axial offset between a longitudinal axis of the nozzle needle and a longitudinal axis of the piezoelectric actuator. In addition, it reverses the effective direction of the piezoelectric actuator.
  • the coupling device comprises a coupler piston which has an actuator-side hydraulic active surface for limiting an actuator-side Coupler volume and a nozzle-side hydraulic active surface for limiting a nozzle-side Kopplervolumens has and is interspersed to connect the two volumes of an axial bore.
  • the nozzle-side coupler volume is divided by a throttle plate into a first partial volume and a second partial volume.
  • the two sub-volumes are also connected via a arranged in the throttle plate bore, in which preferably a throttle is formed.
  • the nozzle-side end of the coupler piston is received in a sleeve which is supported on the throttle plate and acted upon in the direction of the throttle plate by the spring force of a spring.
  • the separation of the nozzle-side Kopplervolumens in two sub-volumes has the advantage that in the region of the throttle plate, the desired axial offset between the longitudinal axis of the nozzle needle and the longitudinal axis of the actuator can be realized.
  • the coupler piston is preferably arranged coaxially to the longitudinal axis of the piezoelectric actuator in this case.
  • the supported on the throttle plate sleeve is displaceable in the radial direction relative to the throttle plate and allows in this way the compensation of manufacturing and / or assembly tolerances.
  • the sleeve can also be used to limit the first sub-volume of the nozzle-side coupler volume in the radial direction on this side of the throttle plate.
  • the nozzle-side hydraulic active surface of the coupler piston on the coupler volume is opposite a hydraulic active surface of the nozzle needle, which is preferably formed on an end face of the nozzle needle facing the piezoelectric actuator.
  • the coupler piston is thus hydraulically coupled via the coupler volume with the nozzle needle.
  • the pressure prevailing in the nozzle-side coupler volume pressurizes the nozzle needle with a hydraulic force acting in the closing direction.
  • the hydraulic force acting in the closing direction can be reduced to such an extent that the nozzle needle opens.
  • the nozzle-side coupler volume is connected to the actuator-side coupler volume via the axial bore in the coupler piston
  • the nozzle needle can also be opened by the actuator volume in the coupler volume Pressure to be lowered. This can be done by moving the coupler piston in the direction of the nozzle needle to increase the actuator-side coupler volume. The pressure in the actuator-side coupler volume drops.
  • the movement of the coupler piston in the direction of the nozzle needle has the consequence that the volume of the nozzle-side coupler volume is reduced.
  • the volume reduction should actually lead to an increase in pressure.
  • the nozzle-side coupler volume is in communication with the actuator-side coupler volume via the axial bore in the coupler piston, a pressure reduction in the coupler volume on the nozzle side can be effected at the same time via the pressure reduction in the actuator-side coupler volume.
  • the nozzle-side hydraulic effective area of the coupler piston is smaller than the actuator-side hydraulic effective area. This means that in particular the area ratio of the hydraulic active surfaces on the coupler piston is decisive, whether in the nozzle-side coupler volume, a pressure increase or a
  • the ratio is generally to be reduced by a factor of 1
  • the area ratio can be chosen such that the ratio is reduced by less than a factor of one.
  • the coupler piston is designed to be single or multi-stepped for this purpose.
  • the coupler piston of the coupling device is arranged in a high-pressure chamber of the fuel injector.
  • the supply of high-pressure fuel can therefore be carried out substantially centrally over a wide range. Elaborate to be produced separate Zulaufbohrungen in the body components of the fuel injector can be omitted, so that its production is further simplified.
  • the high-pressure chamber of the fuel injector is preferably via a coupler plate of a Low-pressure space separated, in which further preferably the piezoelectric actuator is added. The arrangement of the actuator in low pressure favors its life.
  • the coupler plate limits the actuator-side coupler volume in the axial and / or radial direction.
  • the actuator-side coupler volume is formed in the coupler plate, that is, the coupler plate limits the coupler volume in the axial and radial directions.
  • a recess may be formed in the coupler plate, in which the actuator-side end of the coupler piston is received such that between the coupler piston and the bottom of the recess a usable volume as a coupler volume remains.
  • a guide of the coupler piston can be effected in this way, a guide of the coupler piston.
  • the actuator end of the nozzle needle is received in a sleeve which is supported on the throttle plate and acted upon in the direction of the throttle plate by the spring force of the nozzle spring.
  • the sleeve is in turn displaceable in the radial direction relative to the throttle plate and thus enables the compensation of manufacturing and / or assembly tolerances.
  • the sleeve can be used to limit the second sub-volume of the nozzle-side coupler volume beyond the throttle plate in the radial direction.
  • the actuation of the coupler piston of the coupling device via the piezoelectric actuator requires an active connection of the piezoelectric actuator with the coupler piston.
  • the piezoelectric actuator is operatively connected via a pressure pin to the coupler piston.
  • the pressure pin can be guided through the coupler plate, which separates the high-pressure chamber from the low-pressure chamber, in which the piezoelectric actuator is arranged.
  • the pressure pin preferably has a small guide pressure gauge, so that the leakage in the guide region of the pressure pin is limited.
  • the fuel injector shown in longitudinal section comprises a plurality of body components, namely a nozzle body 1, a throttle plate 19, a sleeve-shaped body member 26, a coupler plate 17 and a holding body 27, which are braced axially via a clamping nut 34.
  • a piezoelectric actuator 7 is accommodated for actuating a liftable nozzle needle 2.
  • the liftable nozzle needle 2 is accommodated for releasing and closing at least one injection opening 3 in a high-pressure bore 4 of the nozzle body 1. In this case, the nozzle needle 2 cooperates with a sealing seat 5.
  • the nozzle needle 2 is acted upon by the spring force of a nozzle spring 6, which is supported in the illustrated embodiment on the one hand on a collar 33 of the nozzle needle 2 and on the other hand on a sleeve 24 which surrounds a aktor workedes end of the nozzle needle 2.
  • the spring force of the nozzle spring 6 holds the sleeve 24 in abutment with the throttle plate 19th
  • the nozzle needle 2, the sleeve 24 and the throttle plate 19 define a partial volume 13.2, which communicates via a formed in the throttle plate 19 throttle bore 20, 21 with a further sub-volume 13.1.
  • the further partial volume 13.1 is bounded by the throttle plate 19, a sleeve 22 supported thereon and a lifting coupler piston 9 of a coupling device 8 whose nozzle-side end is received in the sleeve 22.
  • the sleeve 22 is acted upon by the spring force of a spring 23, which holds the sleeve 22 in abutment with the throttle plate 19.
  • the two sub-volumes 13.1, 13.2 together form a nozzle-side coupler volume 13 of the coupling device 8, which is connected via an axial bore 15 in the coupler piston 9 in conjunction with an actuator-side coupler volume 14 of the coupling device 8.
  • the pressure in the two coupler volumes 13, 14 is thus approximately equal.
  • the actuator-side coupler volume 14 is formed in the coupler plate 17, which is equipped for this purpose with a hollow cylindrical projection which surrounds the actuator-side end of the coupler piston 9.
  • the coupler plate 17 also serves to separate a high-pressure chamber 16, in which the coupling device 8 is received, from a low-pressure chamber 18, which is formed in the holding body 27 and serves to receive the piezoelectric actuator 7.
  • a pressure pin 25 is guided by the coupler plate 17, so that the piezoelectric actuator 7 and the coupler piston 9 are mechanically coupled.
  • the coupler piston 9 and the two coupler volumes 13, 14 comprehensive coupling device 8 is used for the hydraulic coupling of the piezoelectric actuator 7 with the nozzle needle 2, so that the lifting movement of the nozzle needle 2 via the piezoelectric actuator 7 is directly controlled.
  • the coupling device 8 is designed such that the effective direction of the piezoelectric actuator 7 is reversed. Furthermore, an amplification of the actuator force is effected via the coupling device 8.
  • the actuator 7 For closing the injection opening 3, the actuator 7 is deactivated. This has the consequence that the actuator 7 contracts again and the spring force of the spring 23 resets the coupler piston 9 in its initial position. This is accompanied by a reduction of the actuator-side coupler volume 14, so that herein a pressure increase is effected. For the reasons already mentioned above is also a pressure increase in nozzle-side coupler volume 13 causes, so that a hydraulic closing force acts on a hydraulic active surface 12 of the nozzle needle 2. This in conjunction with the spring force of the nozzle spring 6 causes the nozzle needle 2 is returned to the sealing seat 5 and the injection is terminated.
  • the connection of the low-pressure space 18 to a return 32 is provided. Since the illustrated fuel injector is a directly operable injector, however, the quantities to be discharged are small. In particular, no Abêtmenge of a servo valve as in indirectly operable fuel injectors.

Landscapes

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

Description

Die Erfindung betrifft einen Kraftstoffinjektor zum Einspritzen von Kraftstoff in einen Brennraum einer Brennkraftmaschine mit den Merkmalen des Oberbegriffs des Anspruchs 1.The invention relates to a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine having the features of the preamble of claim 1.

Stand der TechnikState of the art

Aus der Offenlegungsschrift DE 10 2008 002 412 A1 ist ein Kraftstoffinjektor zum Einspritzen von Kraftstoff in einen Brennraum einer Brennkraftmaschine bekannt, der zum Freigeben und Verschließen wenigstens einer Einspritzöffnung eine in einer Hochdruckbohrung eines Düsenkörpers hubbeweglich aufgenommene Düsennadel sowie einen Piezoaktor zur Steuerung der Hubbewegung der Düsennadel besitzt. Der Piezoaktor ist hierzu mit der Düsennadel hydraulisch gekoppelt und betätigt einen in einem Kopplungsraum verdrängerwirksamen Geberkolben, während die Düsennadel mit einem im Kopplungsraum verdrängerwirksamen Nehmerkolben hubgekoppelt ist. Um im Injektorkörper notwendige Hochdruckleitungen unterbringen zu können, besitzen der Piezoaktor und der Geberkolben einerseits und die Düsennadel und der Nehmerkolben andererseits unterschiedliche Hubachsen, wobei diese Hubachsen zueinander parallel und seitlich versetzt angeordnet sind. Die Wirkrichtung des Piezoaktors entspricht dabei der Bewegungsrichtung der Düsennadel, so dass die Aktivierung des Piezoaktors eine auf die Düsennadel wirkende Schließkraft erzeugt.From the publication DE 10 2008 002 412 A1 a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine is known, which has for releasing and closing at least one injection port in a high-pressure bore of a nozzle body liftably received nozzle needle and a piezoelectric actuator for controlling the lifting movement of the nozzle needle. For this purpose, the piezoactuator is hydraulically coupled to the nozzle needle and actuates a master piston which acts as a displacer in a coupling space, while the nozzle needle is coupled in a coupled manner to a slave piston which displaces the coupling space in the coupling space. To be able to accommodate necessary high-pressure lines in the injector body, the piezoelectric actuator and the master piston on the one hand and the nozzle needle and the slave piston on the other hand have different lifting axes, these lifting axes are arranged parallel to each other and laterally offset. The direction of action of the piezoelectric actuator corresponds to the direction of movement of the nozzle needle, so that the activation of the piezoelectric actuator generates a closing force acting on the nozzle needle.

Darüber hinaus sind Kraftstoffinjektoren mit sogenannten "Umkehrkopplern" bekannt, die eine Umkehrung der Wirkrichtung des Piezoaktors ermöglichen, so dass die Aktivierung des Piezoaktors zum Öffnen der Düsennadel erfolgt. Ein solcher Kraftstoffinjektor geht beispielhaft aus der Offenlegungsschrift DE 10 2011 003 443 A1 hervor. Bei Aktivierung längt sich der Piezoaktor und bewegt den Geberkolben entgegen der Federkraft einer Vorspannfeder in Richtung der Düsennadel, so dass der Druck in einem ersten Kopplerraum ansteigt. Der erste Kopplerraum steht mit einem weiteren Kopplerraum in Verbindung, der unterhalb eines mit der Düsennadel verbundenen Kopplerkolbens angeordnet ist, so dass der im weiteren Kopplerraum bewirkte Druckanstieg zum Abheben der Düsennadel von ihrem Dichtsitz führt. Zum Schließen wird die Aktivierung des Piezoaktors beendet, der sich daraufhin wieder zusammenzieht, wobei die Federkraft der Vorspannfeder zur Rückstellung des Geberkolbens führt. Die beiden Kopplerräume werden entlastet, während in einem weiteren Kopplervolumen ein auf die Düsennadel wirkender Schließdruck aufgebaut wird, so dass in der Folge auch die Düsennadel in ihren Dichtsitz zurückgestellt wird.In addition, fuel injectors with so-called "reversing couplers" are known, which allow a reversal of the effective direction of the piezoelectric actuator, so that the activation of the piezoelectric actuator takes place for opening the nozzle needle. Such a fuel injector is an example of the published patent application DE 10 2011 003 443 A1 out. at Activation lasts the piezoelectric actuator and moves the master piston against the spring force of a biasing spring in the direction of the nozzle needle, so that the pressure rises in a first coupler space. The first coupler space communicates with a further coupler space, which is arranged below a coupler piston connected to the nozzle needle, so that the increase in pressure caused in the further coupler space leads to the lifting of the nozzle needle from its sealing seat. To close the activation of the piezoelectric actuator is terminated, which then contracts again, the spring force of the biasing spring leads to the return of the master piston. The two coupler spaces are relieved, while in a further coupler volume acting on the nozzle needle closing pressure is built up, so that in the sequence and the nozzle needle is returned to its sealing seat.

Aus der DE102008002417 ist ein weiterer Kraftstoffinjektor mit einem Umkehrkoppler bekannt. Der vorliegenden Erfindung liegt die Aufgabe zugrunde, den Aufbau eines Kraftstoffinjektors mit exzentrisch angeordnetem Piezoaktor und mit Umkehrkoppler zu vereinfachen.From the DE102008002417 is another fuel injector with a reverse coupler known. The present invention has for its object to simplify the structure of a fuel injector with eccentrically arranged piezoelectric actuator and reversing coupler.

Zur Lösung der Aufgabe wird der Kraftstoffinjektor mit den Merkmalen des Anspruchs 1 vorgeschlagen. Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen angegeben.To solve the problem, the fuel injector with the features of claim 1 is proposed. Advantageous developments of the invention are specified in the subclaims.

Offenbarung der ErfindungDisclosure of the invention

Der zum Einspritzen von Kraftstoff in einen Brennraum einer Brennkraftmaschine vorgeschlagene Kraftstoffinjektor umfasst einen Düsenkörper und eine Düsennadel, die zum Freigeben und Verschließen wenigstens einer Einspritzöffnung in einer Hochdruckbohrung des Düsenkörpers hubbeweglich aufgenommen und in Richtung eines Dichtsitzes von der Federkraft einer Düsenfeder beaufschlagt ist. Ferner umfasst der Kraftstoffinjektor einen Piezoaktor, der zur Steuerung der Hubbewegung der Düsennadel über eine Kopplungseinrichtung mit der Düsennadel hydraulisch gekoppelt ist. Die Kopplungseinrichtung gleicht dabei einen Achsversatz zwischen einer Längsachse der Düsennadel und einer Längsachse des Piezoaktors aus. Zudem kehrt sie die Wirkrichtung der Piezoaktors um. Zur Umkehrung der Wirkrichtung des Piezoaktors wird erfindungsgemäß vorgeschlagen, dass die Kopplungseinrichtung einen Kopplerkolben umfasst, der eine aktorseitige hydraulische Wirkfläche zur Begrenzung eines aktorseitigen Kopplervolumens und eine düsenseitige hydraulische Wirkfläche zur Begrenzung eines düsenseitigen Kopplervolumens besitzt und zur Verbindung der beiden Volumina von einer Axialbohrung durchsetzt ist. Das düsenseitige Kopplervolumen ist durch eine Drosselplatte in ein erstes Teilvolumen und ein zweites Teilvolumen unterteilt. Die beiden Teilvolumina sind ferner über eine in der Drosselplatte angeordnete Bohrung, in welcher vorzugsweise eine Drossel ausgebildet ist, verbunden. Weiterhin ist das düsenseitige Ende des Kopplerkolbens in einer Hülse aufgenommen, die an der Drosselplatte abgestützt und in Richtung der Drosselplatte von der Federkraft einer Feder beaufschlagt ist.The fuel injector proposed for injecting fuel into a combustion chamber of an internal combustion engine comprises a nozzle body and a nozzle needle which is liftably received for releasing and closing at least one injection opening in a high-pressure bore of the nozzle body and acted upon in the direction of a sealing seat by the spring force of a nozzle spring. Furthermore, the fuel injector comprises a piezoelectric actuator, which is hydraulically coupled to control the lifting movement of the nozzle needle via a coupling device with the nozzle needle. The coupling device compensates for an axial offset between a longitudinal axis of the nozzle needle and a longitudinal axis of the piezoelectric actuator. In addition, it reverses the effective direction of the piezoelectric actuator. In order to reverse the effective direction of the piezoelectric actuator, it is proposed according to the invention that the coupling device comprises a coupler piston which has an actuator-side hydraulic active surface for limiting an actuator-side Coupler volume and a nozzle-side hydraulic active surface for limiting a nozzle-side Kopplervolumens has and is interspersed to connect the two volumes of an axial bore. The nozzle-side coupler volume is divided by a throttle plate into a first partial volume and a second partial volume. The two sub-volumes are also connected via a arranged in the throttle plate bore, in which preferably a throttle is formed. Furthermore, the nozzle-side end of the coupler piston is received in a sleeve which is supported on the throttle plate and acted upon in the direction of the throttle plate by the spring force of a spring.

Die Trennung des düsenseitigen Kopplervolumens in zwei Teilvolumina besitzt den Vorteil, dass im Bereich der Drosselplatte der angestrebte Achsversatz zwischen der Längsachse der Düsennadel und der Längsachse des Aktors realisierbar ist. Der Kopplerkolben ist in diesem Fall bevorzugt koaxial zur Längsachse des Piezoaktors angeordnet. Die an der Drosselplatte abgestützte Hülse ist in radialer Richtung gegenüber der Drosselplatte verschiebbar und ermöglicht auf diese Weise den Ausgleich von Fertigungs- und/oder Montagetoleranzen. Die Hülse kann ferner dazu eingesetzt werden, das erste Teilvolumen des düsenseitigen Kopplervolumens diesseits der Drosselplatte in radialer Richtung zu begrenzen.The separation of the nozzle-side Kopplervolumens in two sub-volumes has the advantage that in the region of the throttle plate, the desired axial offset between the longitudinal axis of the nozzle needle and the longitudinal axis of the actuator can be realized. The coupler piston is preferably arranged coaxially to the longitudinal axis of the piezoelectric actuator in this case. The supported on the throttle plate sleeve is displaceable in the radial direction relative to the throttle plate and allows in this way the compensation of manufacturing and / or assembly tolerances. The sleeve can also be used to limit the first sub-volume of the nozzle-side coupler volume in the radial direction on this side of the throttle plate.

Ferner wird vorgeschlagen, dass der düsenseitigen hydraulischen Wirkfläche des Kopplerkolbens am Kopplervolumen eine hydraulische Wirkfläche der Düsennadel gegenüber liegt, die vorzugsweise an einer dem Piezoaktor zugewandten Stirnfläche der Düsennadel ausgebildet ist. Der Kopplerkolben ist somit über das Kopplervolumen mit der Düsennadel hydraulisch gekoppelt. Dabei beaufschlagt der im düsenseitigen Kopplervolumen herrschende Druck die Düsennadel mit einer in Schließrichtung wirkenden hydraulischen Kraft. Durch Absenken des Drucks im düsenseitigen Kopplervolumen kann die in Schließrichtung wirkende hydraulische Kraft soweit reduziert werden, dass die Düsennadel öffnet. Da erfindungsgemäß das düsenseitige Kopplervolumen über die Axialbohrung im Kopplerkolben mit dem aktorseitigen Kopplervolumen verbunden ist, kann zum Öffnen der Düsennadel auch der im aktorseitigen Kopplervolumen herrschende Druck abgesenkt werden. Dies kann in der Weise erfolgen, dass der Kopplerkolben in Richtung der Düsennadel bewegt wird, um das aktorseitige Kopplervolumen zu vergrößern. Dabei sinkt der Druck im aktorseitigen Kopplervolumen ab.It is also proposed that the nozzle-side hydraulic active surface of the coupler piston on the coupler volume is opposite a hydraulic active surface of the nozzle needle, which is preferably formed on an end face of the nozzle needle facing the piezoelectric actuator. The coupler piston is thus hydraulically coupled via the coupler volume with the nozzle needle. In this case, the pressure prevailing in the nozzle-side coupler volume pressurizes the nozzle needle with a hydraulic force acting in the closing direction. By lowering the pressure in the nozzle-side coupler volume, the hydraulic force acting in the closing direction can be reduced to such an extent that the nozzle needle opens. Since, according to the invention, the nozzle-side coupler volume is connected to the actuator-side coupler volume via the axial bore in the coupler piston, the nozzle needle can also be opened by the actuator volume in the coupler volume Pressure to be lowered. This can be done by moving the coupler piston in the direction of the nozzle needle to increase the actuator-side coupler volume. The pressure in the actuator-side coupler volume drops.

Die Bewegung des Kopplerkolbens in Richtung der Düsennadel hat zur Folge, dass das Volumen des düsenseitigen Kopplervolumens verkleinert wird. Die Volumenverkleinerung müsste eigentlich zu einem Druckanstieg führen. Da das düsenseitige Kopplervolumen jedoch über die Axialbohrung im Kopplerkolben in Verbindung mit dem aktorseitigen Kopplervolumen steht, kann über die Druckabsenkung im aktorseitigen Kopplervolumen zugleich eine Druckabsenkung im düsenseitigen Kopplervolumen bewirkt werden. Dies gilt insbesondere, wenn gemäß einer bevorzugten Ausführungsform der Erfindung die düsenseitige hydraulische Wirkfläche des Kopplerkolbens kleiner als die aktorseitige hydraulische Wirkfläche ist. Das heißt, dass insbesondere das Flächenverhältnis der hydraulischen Wirkflächen am Kopplerkolben entscheidend ist, ob im düsenseitigen Kopplervolumen ein Druckanstieg oder einThe movement of the coupler piston in the direction of the nozzle needle has the consequence that the volume of the nozzle-side coupler volume is reduced. The volume reduction should actually lead to an increase in pressure. However, since the nozzle-side coupler volume is in communication with the actuator-side coupler volume via the axial bore in the coupler piston, a pressure reduction in the coupler volume on the nozzle side can be effected at the same time via the pressure reduction in the actuator-side coupler volume. This is especially true if, according to a preferred embodiment of the invention, the nozzle-side hydraulic effective area of the coupler piston is smaller than the actuator-side hydraulic effective area. This means that in particular the area ratio of the hydraulic active surfaces on the coupler piston is decisive, whether in the nozzle-side coupler volume, a pressure increase or a

Druckabfall bewirkt wird. Ferner kann über das Flächenverhältnis eine Übersetzung bewirkt werden. Während bei aus dem Stand der Technik bekannten Umkehrkopplern aufgrund der Gegenläufigkeit und der Größe der Flächen die Übersetzung in der Regel um den Faktor 1 zu reduzieren ist, kann vorliegend das Flächenverhältnis derart gewählt werden, dass die Übersetzung um weniger als den Faktor 1 reduziert ist. Denn vorliegend ist das Flächenverhältnis der hydraulischen Wirkflächen am Kopplerkolben frei wählbar. Vorteilhafterweise ist hierzu der Kopplerkolben einfach oder mehrfach gestuft ausgeführt.Pressure drop is effected. Furthermore, a translation can be effected via the area ratio. Whereas in the case of reversing couplers known from the prior art, because of the counter-rotation and the size of the surfaces, the ratio is generally to be reduced by a factor of 1, in the present case the area ratio can be chosen such that the ratio is reduced by less than a factor of one. Because in the present case, the area ratio of the hydraulic active surfaces on the coupler piston is freely selectable. Advantageously, the coupler piston is designed to be single or multi-stepped for this purpose.

Weiterhin bevorzugt ist zumindest der Kopplerkolben der Kopplungseinrichtung in einem Hochdruckraum des Kraftstoffinjektors angeordnet. Das heißt, dass der Kopplerkolben von Hochdruck umgeben ist. Die Zuleitung des unter hohem Druck stehenden Kraftstoffs kann demnach über weite Bereiche im Wesentlichen zentral erfolgen. Aufwendig zu fertigende separate Zulaufbohrungen in den Körperbauteilen des Kraftstoffinjektors können entfallen, so dass dessen Fertigung weiter vereinfacht wird. Der Hochdruckraum des Kraftstoffinjektors wird vorzugsweise über eine Kopplerplatte von einem Niederdruckraum getrennt, in dem weiterhin vorzugsweise der Piezoaktor aufgenommen ist. Die Anordnung des Aktors im Niederdruck begünstigt dessen Lebensdauer.Further preferably, at least the coupler piston of the coupling device is arranged in a high-pressure chamber of the fuel injector. This means that the coupler piston is surrounded by high pressure. The supply of high-pressure fuel can therefore be carried out substantially centrally over a wide range. Elaborate to be produced separate Zulaufbohrungen in the body components of the fuel injector can be omitted, so that its production is further simplified. The high-pressure chamber of the fuel injector is preferably via a coupler plate of a Low-pressure space separated, in which further preferably the piezoelectric actuator is added. The arrangement of the actuator in low pressure favors its life.

In Weiterbildung der Erfindung wird vorgeschlagen, dass die Kopplerplatte das aktorseitige Kopplervolumen in axialer und/oder radialer Richtung begrenzt. Vorteilhafterweise ist das aktorseitige Kopplervolumen in der Kopplerplatte ausgebildet, das heißt, dass die Kopplerplatte das Kopplervolumen in axialer und radialer Richtung begrenzt. Beispielsweise kann in der Kopplerplatte eine Ausnehmung ausgebildet sein, in welcher das aktorseitige Ende des Kopplerkolbens derart aufgenommen ist, dass zwischen dem Kopplerkolben und dem Boden der Ausnehmung ein als Kopplervolumen einsetzbares Volumen verbleibt. Über die Kopplerplatte kann auf diese Weise auch eine Führung des Kopplerkolbens bewirkt werden.In a further development of the invention, it is proposed that the coupler plate limits the actuator-side coupler volume in the axial and / or radial direction. Advantageously, the actuator-side coupler volume is formed in the coupler plate, that is, the coupler plate limits the coupler volume in the axial and radial directions. For example, a recess may be formed in the coupler plate, in which the actuator-side end of the coupler piston is received such that between the coupler piston and the bottom of the recess a usable volume as a coupler volume remains. About the coupler plate can be effected in this way, a guide of the coupler piston.

Alternativ oder ergänzend wird vorgeschlagen, dass das aktorseitige Ende der Düsennadel in einer Hülse aufgenommen ist, die an der Drosselplatte abgestützt und in Richtung der Drosselplatte von der Federkraft der Düsenfeder beaufschlagt ist. Die Hülse ist wiederum in radialer Richtung verschiebbar gegenüber der Drosselplatte und ermöglicht somit den Ausgleich von Fertigungs- und/oder Montagetoleranzen. Ferner kann die Hülse dazu eingesetzt werden, das zweite Teilvolumen des düsenseitigen Kopplervolumens jenseits der Drosselplatte in radialer Richtung zu begrenzen.Alternatively or additionally, it is proposed that the actuator end of the nozzle needle is received in a sleeve which is supported on the throttle plate and acted upon in the direction of the throttle plate by the spring force of the nozzle spring. The sleeve is in turn displaceable in the radial direction relative to the throttle plate and thus enables the compensation of manufacturing and / or assembly tolerances. Furthermore, the sleeve can be used to limit the second sub-volume of the nozzle-side coupler volume beyond the throttle plate in the radial direction.

Die Betätigung des Kopplerkolbens der Kopplungseinrichtung über den Piezoaktor erfordert eine Wirkverbindung des Piezoaktors mit dem Kopplerkolben. Bevorzugt ist der Piezoaktor über einen Druckstift mit dem Kopplerkolben wirkverbunden. Der Druckstift kann durch die Kopplerplatte geführt sein, der den Hochdruckraum vom Niederdruckraum trennt, in dem der Piezoaktor angeordnet ist. Der Druckstift besitzt vorzugsweise einen kleinen Führungsdruckmesser, so dass die Leckage im Führungsbereich des Druckstifts begrenzt ist.The actuation of the coupler piston of the coupling device via the piezoelectric actuator requires an active connection of the piezoelectric actuator with the coupler piston. Preferably, the piezoelectric actuator is operatively connected via a pressure pin to the coupler piston. The pressure pin can be guided through the coupler plate, which separates the high-pressure chamber from the low-pressure chamber, in which the piezoelectric actuator is arranged. The pressure pin preferably has a small guide pressure gauge, so that the leakage in the guide region of the pressure pin is limited.

Eine bevorzugte Ausführungsform der Erfindung wird nachfolgend anhand der beigefügten Zeichnung näher erläutert. Diese zeigt einen schematischen Längsschnitt durch einen erfindungsgemäßen Kraftstoffinjektor.A preferred embodiment of the invention will be explained in more detail with reference to the accompanying drawings. This shows a schematic longitudinal section through a fuel injector according to the invention.

Ausführliche Beschreibung der ZeichnungDetailed description of the drawing

Der im Längsschnitt dargestellte Kraftstoffinjektor umfasst mehrere Körperbauteile, nämlich einen Düsenkörper 1, eine Drosselplatte 19, ein hülsenförmiges Körperbauteil 26, eine Kopplerplatte 17 sowie einen Haltekörper 27, die über eine Spannmutter 34 axial verspannt sind. In dem Haltekörper 27 ist ein Piezoaktor 7 zur Betätigung einer hubbeweglichen Düsennadel 2 aufgenommen ist. Die hubbewegliche Düsennadel 2 ist zum Freigeben und Verschließen wenigstens einer Einspritzöffnung 3 in einer Hochdruckbohrung 4 des Düsenkörpers 1 aufgenommen. Hierbei wirkt die Düsennadel 2 mit einem Dichtsitz 5 zusammen. In Richtung des Dichtsitzes 5 wird die Düsennadel 2 von der Federkraft einer Düsenfeder 6 beaufschlagt, die im dargestellten Ausführungsbeispiel einerseits an einem Bund 33 der Düsennadel 2 und andererseits an einer Hülse 24 abgestützt ist, welche ein aktorseitiges Ende der Düsennadel 2 umgibt. Die Federkraft der Düsenfeder 6 hält die Hülse 24 in Anlage mit der Drosselplatte 19.The fuel injector shown in longitudinal section comprises a plurality of body components, namely a nozzle body 1, a throttle plate 19, a sleeve-shaped body member 26, a coupler plate 17 and a holding body 27, which are braced axially via a clamping nut 34. In the holding body 27, a piezoelectric actuator 7 is accommodated for actuating a liftable nozzle needle 2. The liftable nozzle needle 2 is accommodated for releasing and closing at least one injection opening 3 in a high-pressure bore 4 of the nozzle body 1. In this case, the nozzle needle 2 cooperates with a sealing seat 5. In the direction of the sealing seat 5, the nozzle needle 2 is acted upon by the spring force of a nozzle spring 6, which is supported in the illustrated embodiment on the one hand on a collar 33 of the nozzle needle 2 and on the other hand on a sleeve 24 which surrounds a aktorseitiges end of the nozzle needle 2. The spring force of the nozzle spring 6 holds the sleeve 24 in abutment with the throttle plate 19th

Die Düsennadel 2, die Hülse 24 und die Drosselplatte 19 begrenzen ein Teilvolumen 13.2, das über eine in der Drosselplatte 19 ausgebildete Drosselbohrung 20, 21 mit einem weiteren Teilvolumen 13.1 in Verbindung steht. Das weitere Teilvolumen 13.1 wird von der Drosselplatte 19, einer hieran abgestützten Hülse 22 sowie einem hubbeweglichen Kopplerkolben 9 einer Kopplungseinrichtung 8 begrenzt, dessen düsenseitiges Ende in der Hülse 22 aufgenommen ist. Die Hülse 22 wird von der Federkraft einer Feder 23 beaufschlagt, welche die Hülse 22 in Anlage mit der Drosselplatte 19 hält. Die beiden Teilvolumina 13.1, 13.2 bilden gemeinsam ein düsenseitiges Kopplervolumen 13 der Kopplungseinrichtung 8 aus, das über eine Axialbohrung 15 im Kopplerkolben 9 in Verbindung mit einem aktorseitigen Kopplervolumen 14 der Kopplungseinrichtung 8 steht. Der Druck in den beiden Kopplervolumina 13, 14 ist somit annähernd gleich. Das aktorseitige Kopplervolumen 14 ist in der Kopplerplatte 17 ausgebildet, die hierzu mit einem hohlzylinderförmigen Ansatz ausgestattet ist, welcher das aktorseitige Ende des Kopplerkolbens 9 umgibt. Die Kopplerplatte 17 dient ferner der Trennung eines Hochdruckraums 16, in welchem die Kopplungseinrichtung 8 aufgenommen ist, von einem Niederdruckraum 18, der im Haltekörper 27 ausgebildet ist und der Aufnahme des Piezoaktors 7 dient. Um eine Wirkverbindung zwischen dem im Niederdruckraum 18 aufgenommenen Piezoaktor 7 und dem im Hochdruckraum 16 aufgenommenen Kopplerkolben 9 herzustellen, ist durch die Kopplerplatte 17 ein Druckstift 25 geführt, so dass der Piezoaktor 7 und der Kopplerkolben 9 mechanisch gekoppelt sind.The nozzle needle 2, the sleeve 24 and the throttle plate 19 define a partial volume 13.2, which communicates via a formed in the throttle plate 19 throttle bore 20, 21 with a further sub-volume 13.1. The further partial volume 13.1 is bounded by the throttle plate 19, a sleeve 22 supported thereon and a lifting coupler piston 9 of a coupling device 8 whose nozzle-side end is received in the sleeve 22. The sleeve 22 is acted upon by the spring force of a spring 23, which holds the sleeve 22 in abutment with the throttle plate 19. The two sub-volumes 13.1, 13.2 together form a nozzle-side coupler volume 13 of the coupling device 8, which is connected via an axial bore 15 in the coupler piston 9 in conjunction with an actuator-side coupler volume 14 of the coupling device 8. The pressure in the two coupler volumes 13, 14 is thus approximately equal. The actuator-side coupler volume 14 is formed in the coupler plate 17, which is equipped for this purpose with a hollow cylindrical projection which surrounds the actuator-side end of the coupler piston 9. The coupler plate 17 also serves to separate a high-pressure chamber 16, in which the coupling device 8 is received, from a low-pressure chamber 18, which is formed in the holding body 27 and serves to receive the piezoelectric actuator 7. To an operative connection between the recorded in the low pressure chamber 18 piezoelectric actuator 7 and in the high pressure chamber 16th Produce recorded coupler piston 9, a pressure pin 25 is guided by the coupler plate 17, so that the piezoelectric actuator 7 and the coupler piston 9 are mechanically coupled.

Die den Kopplerkolben 9 und die beiden Kopplervolumina 13, 14 umfassende Kopplungseinrichtung 8 dient der hydraulischen Kopplung des Piezoaktors 7 mit der Düsennadel 2, so dass die Hubbewegung der Düsennadel 2 über den Piezoaktor 7 direkt steuerbar ist. Die Kopplungseinrichtung 8 ist dabei derart ausgelegt, dass die Wirkrichtung des Piezoaktors 7 umgekehrt wird. Ferner wird über die Kopplungseinrichtung 8 eine Verstärkung der Aktorkraft bewirkt.The coupler piston 9 and the two coupler volumes 13, 14 comprehensive coupling device 8 is used for the hydraulic coupling of the piezoelectric actuator 7 with the nozzle needle 2, so that the lifting movement of the nozzle needle 2 via the piezoelectric actuator 7 is directly controlled. The coupling device 8 is designed such that the effective direction of the piezoelectric actuator 7 is reversed. Furthermore, an amplification of the actuator force is effected via the coupling device 8.

Die Funktionsweise des dargestellten Kraftstoffinjektors ist wie folgt:

  • Zum Freigeben der Einspritzöffnung 3 wird der Piezoaktor 7 aktiviert. Dieser dehnt sich daraufhin aus und drückt den Druckstift 25 nach unten, d. h. in Richtung der Düsennadel 2. Der Druckstift 25 bewegt dabei den Kopplerkolben 9 ebenfalls nach unten, was zur Folge hat, dass sich das aktorseitige Kopplervolumen 14 vergrößert und das düsenseitige Kopplervolumen 13 verkleinert. Dennoch fällt in beiden Kopplervolumina 13, 14 der Druck ab, was auf das Flächenverhältnis der am Kopplerkolben 9 ausgebildeten hydraulischen Wirkflächen 10, 11 zurückzuführen ist. Denn die das aktorseitige Kopplervolumen 14 begrenzende aktorseitige hydraulische Wirkfläche 10 ist deutlich größer als die das düsenseitige Kopplervolumen 13 begrenzende hydraulische Wirkfläche 11 gewählt. Der demzufolge im düsenseitigen Kopplervolumen 13 eintretende Druckabfall bewirkt schließlich das Öffnen der Düsennadel 2. Über einen seitlich im Haltekörper 27 ausgebildeten Zulaufkanal 28, der an eine Hochdruckquelle 29 angeschlossen ist, sowie Durchströmöffnungen 30, 31 in den weiteren Körperbauteilen wird dann der Hochdruckbohrung 4 und damit der Einspritzöffnung 3 unter hohem Druck stehender Kraftstoff zugeführt.
The operation of the illustrated fuel injector is as follows:
  • To release the injection opening 3 of the piezoelectric actuator 7 is activated. This then expands and pushes the pressure pin 25 down, ie in the direction of the nozzle needle 2. The pressure pin 25 moves the coupler piston 9 also down, which has the consequence that increases the actuator-side coupler volume 14 and the nozzle-side coupler volume 13 is reduced , Nevertheless, the pressure drops in both coupler volumes 13, 14, which is due to the area ratio of the hydraulic active surfaces 10, 11 formed on the coupler piston 9. Because the actuator-side coupler volume 14 limiting actuator-side hydraulic active surface 10 is much larger than the nozzle-side coupler volume 13 limiting hydraulic active surface 11 selected. Finally, the pressure drop occurring in the nozzle-side coupler volume 13 causes the nozzle needle 2 to open. Via a laterally formed in the holding body 27 inlet channel 28 which is connected to a high pressure source 29, and flow openings 30, 31 in the other body components is then the high-pressure bore 4 and thus supplied to the injection port 3 under high pressure fuel.

Zum Verschließen der Einspritzöffnung 3 wird der Aktor 7 deaktiviert. Dies hat zur Folge, dass sich der Aktor 7 wieder zusammenzieht und die Federkraft der Feder 23 den Kopplerkolben 9 in seine Ausgangslage zurückstellt. Damit einher geht eine Verkleinerung des aktorseitigen Kopplervolumens 14, so dass hierin ein Druckanstieg bewirkt wird. Aus den bereits vorstehend genannten Gründen wird ferner ein Druckanstieg im düsenseitigen Kopplervolumen 13 bewirkt, so dass auf eine hydraulische Wirkfläche 12 der Düsennadel 2 eine hydraulische Schließkraft wirkt. Diese in Verbindung mit der Federkraft der Düsenfeder 6 bewirkt, dass die Düsennadel 2 in den Dichtsitz 5 zurückgestellt und die Einspritzung beendet wird.For closing the injection opening 3, the actuator 7 is deactivated. This has the consequence that the actuator 7 contracts again and the spring force of the spring 23 resets the coupler piston 9 in its initial position. This is accompanied by a reduction of the actuator-side coupler volume 14, so that herein a pressure increase is effected. For the reasons already mentioned above is also a pressure increase in nozzle-side coupler volume 13 causes, so that a hydraulic closing force acts on a hydraulic active surface 12 of the nozzle needle 2. This in conjunction with the spring force of the nozzle spring 6 causes the nozzle needle 2 is returned to the sealing seat 5 and the injection is terminated.

Um eine etwaige in den Niederdruckraum 18 gelangende Leckagemenge abzuführen, ist vorliegend der Anschluss des Niederdruckraums 18 an einen Rücklauf 32 vorgesehen. Da es sich bei dem dargestellten Kraftstoffinjektor um einen direkt betätigbaren Injektor handelt, sind die abzuführenden Mengen jedoch gering. Insbesondere fällt keine Absteuermenge eines Servoventils wie bei indirekt betätigbaren Kraftstoffinjektoren an.In order to dissipate any amount of leakage reaching the low-pressure space 18, in the present case the connection of the low-pressure space 18 to a return 32 is provided. Since the illustrated fuel injector is a directly operable injector, however, the quantities to be discharged are small. In particular, no Absteuermenge of a servo valve as in indirectly operable fuel injectors.

Claims (8)

  1. Fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, comprising a nozzle body (1) and a nozzle needle (2) which, for the purposes of opening up and closing at least one injection opening (3), is received, such that it can perform stroke movements, in a high-pressure bore (4) of the nozzle body (1) and is forced in the direction of a sealing seat (5) by the spring force of a nozzle spring (6), furthermore comprising a piezo actuator (7) which, for the control of the stroke movement of the nozzle needle (2), is hydraulically coupled by means of a coupling device (8) to the nozzle needle (2), wherein the coupling device (8) compensates an axial offset between a longitudinal axis (A1) of the nozzle needle (2) and a longitudinal axis (A2) of the piezo actuator (7) and reverses the direction of action of the piezo actuator (7), wherein the coupling device (8) comprises, for the reversal of the direction of action of the piezo actuator (7), a coupler piston (9) which has an actuator-side hydraulic active surface (10) for delimiting an actuator-side coupler volume (14) and a nozzle-side hydraulic active surface (11) for delimiting a nozzle-side coupler volume (13) and which is extended through by an axial bore (15) for connecting the two volumes (13, 14), characterized in that the nozzle-side coupler volume (13) is divided by a throttle plate (19) into a first partial volume (13.1) and a second partial volume (13.2), and the two partial volumes (13.1, 13.2) are connected by means of a bore (20) which is arranged in the throttle plate (19) and in which a throttle (21) is preferably formed, and in that the nozzle-side end of the coupler piston (9) is received in a sleeve (22) which is supported on the throttle plate (19) and which is forced in the direction of the throttle plate (19) by the spring force of a spring (23).
  2. Fuel injector according to Claim 1,
    characterized in that the nozzle-side hydraulic active surface (11) of the coupler piston (9) is, at the coupler volume (13), situated opposite a hydraulic active surface (12) of the nozzle needle (2), which is preferably formed on a face side, facing toward the piezo actuator (7), of the nozzle needle (2).
  3. Fuel injector according to Claim 1 or 2, characterized in that the nozzle-side hydraulic active surface (11) of the coupler piston (9) is smaller than the actuator-side hydraulic active surface (10).
  4. Fuel injector according to one of the preceding claims, characterized in that at least the coupler piston (9) of the coupling device (8) is arranged in a high-pressure chamber (16) which is preferably separated by means of a coupler plate (17) from a low-pressure chamber (18).
  5. Fuel injector according to Claim 4,
    characterized in that the coupler plate (17) delimits the actuator-side coupler volume (14) in an axial and/or radial direction.
  6. Fuel injector according to Claim 1,
    characterized in that the actuator-side end of the nozzle needle (2) is received in a sleeve (24) which is supported on the throttle plate (19) and which is forced in the direction of the throttle plate (19) by the spring force of the nozzle spring (6).
  7. Fuel injector according to one of the preceding claims,
    characterized in that the piezo actuator (7) is operatively connected by means of a pressure pin (25) to the coupler piston (9).
  8. Fuel injector according to Claim 7,
    characterized in that the pressure pin (25) is guided through the coupler plate (17).
EP15163483.9A 2014-05-27 2015-04-14 Fuel injector Not-in-force EP2949918B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102014210101.8A DE102014210101A1 (en) 2014-05-27 2014-05-27 fuel injector

Publications (2)

Publication Number Publication Date
EP2949918A1 EP2949918A1 (en) 2015-12-02
EP2949918B1 true EP2949918B1 (en) 2017-06-14

Family

ID=52824164

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15163483.9A Not-in-force EP2949918B1 (en) 2014-05-27 2015-04-14 Fuel injector

Country Status (2)

Country Link
EP (1) EP2949918B1 (en)
DE (1) DE102014210101A1 (en)

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005007543A1 (en) * 2005-02-18 2006-08-24 Robert Bosch Gmbh Fuel injector with direct needle control for an internal combustion engine
JP2008151049A (en) * 2006-12-19 2008-07-03 Nippon Soken Inc Fuel injection valve
DE102007006941A1 (en) * 2007-02-13 2008-08-14 Robert Bosch Gmbh Injector for fuel injection system of internal-combustion engine, particularly in motor vehicle, has injector body, stepped coupler piston, in actuator section, is arranged vertically lifted in trunk piston opened for needle
EP1970556B1 (en) * 2007-03-15 2009-12-30 Ford Global Technologies, LLC Injector
DE102008002412A1 (en) 2008-06-13 2009-12-17 Robert Bosch Gmbh Fuel injector for injecting fuel into e.g. direct-injection diesel engine, has actuator coupled with nozzle needle, where actuator and head pistons on one side and needle and slave piston on another side exhibit different stroke axis
DE102008002417A1 (en) * 2008-06-13 2009-12-17 Robert Bosch Gmbh Fuel injector for injecting fuel into e.g. direct-injection diesel engine, has slave piston displaceably arranged in slave side region of coupling area, where slave piston region communicates with master piston region
DE102008054421A1 (en) * 2008-12-09 2010-06-10 Robert Bosch Gmbh Fuel injector for use in motor vehicle, has bar including actuator-side end that extends into low pressure range and is hydraulically coupled with actuator, where circular seat is provided at input side of injection nozzle
DE102009024596A1 (en) * 2009-06-10 2011-04-07 Continental Automotive Gmbh Injection valve with transmission unit
DE102011003443A1 (en) 2011-02-01 2012-08-02 Robert Bosch Gmbh fuel injector
DE102012212614A1 (en) * 2012-07-18 2014-01-23 Continental Automotive Gmbh Piezo injector with hydraulically coupled nozzle needle movement
DE102012223934B4 (en) * 2012-12-20 2015-10-15 Continental Automotive Gmbh piezoinjector

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
EP2949918A1 (en) 2015-12-02
DE102014210101A1 (en) 2015-12-03

Similar Documents

Publication Publication Date Title
EP1714025B1 (en) Fuel injector with a direct controlled injection valve member
EP1856403B1 (en) Fuel injector comprising a directly controlled injection valve member with a double-seat
EP1853813B1 (en) Injection nozzle
EP1688611A2 (en) Fuel injector with direct needle control for an internal combustion engine
EP1763628B1 (en) Injector
EP1872008B1 (en) Fuel-injector with two-stage opening
WO2007144226A1 (en) Fuel injector
EP2949918B1 (en) Fuel injector
DE102015223445A1 (en) Fuel injection valve for injecting a gaseous and / or liquid fuel
EP2249024B1 (en) Fuel injector
EP2930344B1 (en) Fuel injector
EP2957760B1 (en) Nozzle assembly for a fuel injector and fuel injector
EP2905458B1 (en) Nozzle assembly for a fuel injector and fuel injector
EP1825137A1 (en) Fuel injection nozzle
EP2930345B1 (en) Fuel injector
DE102006003486A1 (en) Pump nozzle fuel injector for use in combustion chamber of internal combustion engine, has injection opening, which is released or locked by injection valve member and piezo-actuator controlled by injection valve member
DE102006035982A1 (en) Injector for fuel injection system of internal-combustion engine, has piezo-electric actuator formed as pipe and radially limiting coupling space in its interior in area of its actuator bases
EP1825134A1 (en) Fuel injection nozzle
DE102005025138B4 (en) metering valve
DE102014206975A1 (en) fuel injector
DE102006026398A1 (en) Injector for injecting fuel into a combustion chamber of an internal combustion chamber operates via an actuator while linked to a fuel inlet for supplying fuel under system pressure
DE102005045892A1 (en) Directly driven fuel injector, comprises outwards opening jet needle moved by piezoelectric multi-layer device
DE102014212217A1 (en) fuel injector
DE102014206974A1 (en) fuel injector
DE102013225384A1 (en) fuel injector

Legal Events

Date Code Title Description
AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20160602

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20170301

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: AT

Ref legal event code: REF

Ref document number: 901223

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170615

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502015001201

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20170614

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170915

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170914

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170914

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171014

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502015001201

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 4

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

26N No opposition filed

Effective date: 20180315

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20180430

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180414

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180430

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180430

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180414

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20190414

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190414

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170614

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20150414

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170614

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 901223

Country of ref document: AT

Kind code of ref document: T

Effective date: 20200414

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200414

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20220420

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20220627

Year of fee payment: 8

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 502015001201

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230430

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20231103