EP2226494A1 - Injecteur de carburant doté d'un actionneur piézoélectrique et d'un coupleur hydraulique - Google Patents

Injecteur de carburant doté d'un actionneur piézoélectrique et d'un coupleur hydraulique Download PDF

Info

Publication number
EP2226494A1
EP2226494A1 EP10150609A EP10150609A EP2226494A1 EP 2226494 A1 EP2226494 A1 EP 2226494A1 EP 10150609 A EP10150609 A EP 10150609A EP 10150609 A EP10150609 A EP 10150609A EP 2226494 A1 EP2226494 A1 EP 2226494A1
Authority
EP
European Patent Office
Prior art keywords
coupler
fuel injector
piston
filling channel
fuel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP10150609A
Other languages
German (de)
English (en)
Inventor
Jochen Doehring
Mathias Haenel
Andreas Ellenschlaeger
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 EP2226494A1 publication Critical patent/EP2226494A1/fr
Withdrawn legal-status Critical Current

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
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • 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
    • F02M2200/705—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic with means for filling or emptying hydraulic chamber, e.g. for compensating clearance or thermal expansion

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.
  • Fuel injectors are known with a piezoelectric actuator for actuating a control valve, wherein the piezoelectric actuator via a hydraulic coupler, comprising a coupler piston and a working piston, is coupled to the control valve element.
  • a hydraulic coupler comprising a coupler piston and a working piston
  • Upon actuation of the hydraulic coupler by means of the piezoelectric actuator occurs via guide games between the piston and a guide body (coupler body) to an unavoidable leakage.
  • the refilling of the coupler gap volume also takes place via these guide games.
  • a disadvantage of such fuel injectors is that it can lead to an idling of the coupler volume and thus to a failure of the fuel injector. This is due to the fact that at very long or many short switching times, the leakage from the Kopplerspaltvolumen is greater than the refilling, since the refilling takes place at a much lower pressure difference.
  • the invention has for its object to provide a fuel injector with piezoelectric actuator and hydraulic coupler, which is optimized for a simple structure and on the other hand in terms of improved refill control to allow an increased number of injections per stroke.
  • At least one piston of the hydraulic coupler closes and opens at least one filling channel as a function of its axial position, thereby ensuring, in a surprisingly simple manner, optimal control of the refilling of the coupler gap volume.
  • the invention results in a minimization of the refilling time, whereby the rotational speed, ie the number of cycles of the fuel injector and thus the number of injection per unit time is increased.
  • the rotational speed ie the number of cycles of the fuel injector and thus the number of injection per unit time is increased.
  • the technical efficiency of the hydraulic coupler and thus of the fuel injector is improved.
  • the at least one filling channel for refilling the Kopplerspaltvolumens is not introduced as in the prior art in the working piston, but that the filling channel is introduced into a coupler body.
  • the coupler body is preferably a guide body for the coupler piston and the working piston.
  • the coupler piston and the working piston protrude axially from two opposite sides into the coupler body and axially delimit between them the coupler gap volume, which is preferably bounded radially outwardly by the coupler body.
  • a further embodiment of the invention provides not only a filling channel (refilling channel) for the coupler gap volume, but a plurality of filling channels, preferably uniformly distributed over the circumference of the coupler body. It is further preferred if all filling channels are at an axial height and thus simultaneously opened or closed by the coupler piston.
  • the at least one filling channel is not designed (exclusively) as an oblique bore, but, at least in sections, as a radial bore which runs perpendicular to the longitudinal central axis of the hydraulic coupler. Even more preferably, the edges of the filling channel are rounded in the Ausmündungs Symposium.
  • the coupler gap volume is refilled exclusively via the low-pressure region of the fuel injector.
  • the at least one filling channel in the open state connects the low-pressure region of the fuel injector with the coupler gap volume.
  • the piezoelectric actuator is located in the connected to an injector return port low pressure region of the fuel injector.
  • the coupling piston a switching edge is designed to cooperate with a discharge opening of the filling channel.
  • the provision of such a switching edge ensures a defined opening or closing time and ensures in the closed state of the filling channel sufficient fuel-tightness to prevent compressed during the compression phase fuel from the Kopplerspaltvolumen through the filling channel in the low pressure region.
  • the switching edge is designed as a peripheral edge, ie as an annular edge on the outer circumference of the coupler piston.
  • the switching edge is formed and arranged an annular shoulder of the coupler piston limiting.
  • the switching edge is preferably arranged in the region of a diameter jump of the coupler piston.
  • the stroke of the coupler piston during an injection process is greater than the diameter of the orifice of the at least one filling channel. Most preferably, the stroke of the coupler piston is greater than the minimum diameter of the filling channel.
  • the fuel injector can be an injector, in which the working piston forms the one-piece injection valve element or a part of the multipart injection valve element for closing and releasing at least one injection opening.
  • the fuel injector is a fuel injector with servo circuit, in which by means of the hydraulic coupler, a control valve (servo valve) is operable to connect a limited of the one- or multi-part injection valve element control chamber with a low pressure region of the fuel injector.
  • the control valve element of the control valve can be formed either directly by the working piston of the hydraulic coupler or by an actuatable by means of the working piston, from this separate component.
  • An embodiment of the control valve is preferred as a 3/2-way valve, wherein a 2/2-way valve can be realized.
  • Fig. 1 is designed as a common-rail injector fuel injector 1 for injecting fuel into a combustion chamber, not shown, also shown an internal combustion engine, also not shown.
  • a high pressure pump 2 delivers fuel from a reservoir 3 in a high-pressure fuel storage 4 (Rail). In this fuel, especially diesel, under high pressure, stored in this embodiment about 2000bar.
  • the fuel injector 1 is connected via other, not shown, fuel injectors via a supply line 5.
  • the supply line 5 discharges into an axial supply channel 6 belonging to the high-pressure region of the fuel injector 1, through which fuel flows into a pressure chamber 7.
  • the fuel flows from the pressure chamber 7 in the axial direction past a one-part injection valve element 8 (nozzle needle) through nozzle bores of a nozzle hole arrangement 16 into the combustion chamber of the internal combustion engine.
  • the fuel injector 1 is connected via an injector return port 9 to a return line 10.
  • About the return line 10 can be explained later on a control amount of fuel flow from the fuel injector 1 to the reservoir 3 and are fed back from there from the high pressure circuit.
  • the one-piece injection valve element 8 is guided axially adjustable within a stepped bore 11 of a nozzle body 12 in this embodiment.
  • the nozzle body 12 is braced in connection with a throttle plate and a valve body against a holding body 13 by means of a nozzle retaining nut.
  • the nozzle retaining nut is sealed by means of a copper disk in the direction of the combustion chamber into which projects the nozzle body tip.
  • the injection valve element 8 has at its tip 15 a closing surface (sealing surface), with which the injection valve element 8 can be brought into a tight contact with an injection valve element seat formed inside the nozzle body 12.
  • a closing surface closing surface
  • the injection valve member 8 abuts its injection valve member seat, 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, fuel from the pressure chamber 7, substantially under rail pressure, can flow past the injection valve element seat into the combustion chamber.
  • a control chamber 17 (servo chamber) is limited, which is supplied via an inlet throttle 18 with fuel under high pressure from the supply channel 6.
  • a pressure chamber 14 from which fuel can flow into the combustion chamber when the injection valve element 8 is open, is supplied with fuel from the supply channel 6.
  • the pressure chamber 14 encloses a control chamber 17 limiting, spring-loaded sleeve 32 radially outward.
  • the formed in the sleeve 32 control chamber 17 is connected via an outlet throttle 19 with a control valve chamber 20 which is connected by means of an axially adjustable control valve element 21 (valve pin) with a low pressure region 22 and thus with the injector return port 9.
  • the control valve element 21 is part of a designed as a 3/2-way valve control valve 23 (servo valve).
  • a control valve element 21 located in a first (lower) switching position fuel can flow from the control chamber 17 via the outlet throttle 19 and the control valve chamber 20 into the low-pressure region 22 to the injector return port 9.
  • bypass 45 blocked by the control valve element 21.
  • the connection between the control valve chamber 20 and the low pressure region 22 is blocked and the bypass 45 is released, so that the control chamber 17 via the bypass 45, the control valve chamber 20 and the outlet throttle 19 quickly to high pressure is brought.
  • a piezoelectric actuator 24 is provided, which is coupled via a hydraulic coupler 25 to the control valve element 21.
  • the control valve 23 may be formed directly by the hydraulic coupler 25, more specifically by a working piston 28 (valve piston) of the hydraulic coupler 25 to be explained later.
  • the piezoelectric actuator 24 is energized and expands.
  • movable coupler piston 27 of the hydraulic coupler 25 is moved in the plane down, which in turn the working piston 28 of the hydraulic coupler 25, which is hydraulically coupled via a Kopplerspaltvolumen 29 with the coupler piston 27 in the drawing plane down is moved.
  • the working piston 28 presses on the control valve element 21 which is subsequently moved away from its upper control valve seat 26 against the force of a control closing spring 30 (switching valve spring) and thus releases the fuel flow from the control chamber 17 to the injector return port 9 and at the same time the bypass 45 locks.
  • the flow cross sections of the inlet throttle 18 and the outlet throttle 19 are matched to one another such that in the lower switching position of the control valve 23, a net outflow of fuel from the control chamber 17 results.
  • the pressure in the control chamber 17 decreases rapidly, whereby the injection valve element 8 lifts off from its injection valve element seat, so that fuel can flow out of the pressure chamber 7 through the nozzle hole arrangement 16.
  • the energization of the piezoelectric actuator 24 is interrupted, whereby the piezocrystal stack of the actuator 24 contracts and the coupler piston 27, supported by the spring force of a Bourdon tube 34, is moved in the drawing plane upwards.
  • the working piston 28 pushes, supported by the control closing spring 30, in the plane of the drawing down against the control valve element 21. Between the working piston 28 and the control valve element 21 thus a continuous contact is ensured.
  • the working piston 28 and the control valve element 21 are moved at not energized actuator 24 upwards into the upper switching position in which the control valve element 21 rests against its upper control valve seat 26 and the hydraulic connection from the control chamber 17 to the injector return port 9 blocks.
  • the fuel flowing in through the inlet throttle 18 and via the bypass 45 into the control chamber 17 ensures rapid pressure increase in the control chamber 17 and thus for a hydraulic closing force acting on the injection valve element 8.
  • the resulting closing movement of the injection valve element 8 is supported by a closing spring 31, which is supported at one end on the injection valve element 8 and at the other end to a control chamber 17 limiting sleeve 32.
  • the tube spring 34 is arranged, which is supported with its axial lower end to a peripheral collar 35 of the coupler body 33 and with its axially upper end to a plate 36 which passes centrally through the coupler piston 27 is.
  • the tube spring 34 provides for the bias of in Fig. 2 not shown piezoelectric actuator.
  • the coupler piston 27 forms in the hydraulic coupler 25 shown an axially adjustable valve element of a remindbe sleepventils 37.
  • Part of this mulchbe colllventils 37 is also a number of evenly over the circumference of the Koppler stresses 33 arranged Gearkanälen 38, 37 with the fuel pump from the low pressure region 22 in.
  • the Kopplerspaltvolumen 29 can flow to leakage losses during the compression process, ie occur when energized piezoelectric actuator unavoidable over guide gaps 39, compensate.
  • the peripheral switching edge 40 defines an inner annular shoulder 41 of the coupler piston 27 radially outward.
  • the annular shoulder 41 is formed between a lower, reduced-diameter portion 42 of the coupler piston 27 and an upper guide portion 43, on the outer circumference of the coupler piston 27 is guided within the stepped bore of the coupler body 33.
  • a compression spring 46 is arranged, which is supported with its axially upper end on the coupler body 33 and with its axially lower end to a collar sleeve 47, which is pressed onto the working piston 28 or has shrunk.
  • Fig. 3 shows a further detail of the hydraulic coupler 25. It can be seen a stepwise inwardly tapering filling channel 38, which connects the low pressure region 22 hydraulically with the recirculation valve 37 open with the Kopplerspaltvolumen.
  • Fig. 3 Furthermore, the circular contoured opening 48 of the filling channel 38 can be seen. It can be seen that the Filling channel 38 extends exactly in the radial direction and has a radially outer mouth portion 49 and an adjoining connecting portion 50 which connects the mouth portion 49 with the Kopplerspaltvolumen 29. It is essential that the diameter of the connecting portion 50 (significantly) is smaller than the diameter of the mouth portion 49.
  • the maximum stroke .DELTA.H of the coupler piston 27 is designed so that the maximum stroke .DELTA.H smaller is the diameter D of the orifice 48 in a radially inner region.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)
EP10150609A 2009-03-02 2010-01-13 Injecteur de carburant doté d'un actionneur piézoélectrique et d'un coupleur hydraulique Withdrawn EP2226494A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200910001266 DE102009001266A1 (de) 2009-03-02 2009-03-02 Kraftstoff-Injektor mit piezoelektrischem Aktuator sowie hydraulischem Koppler

Publications (1)

Publication Number Publication Date
EP2226494A1 true EP2226494A1 (fr) 2010-09-08

Family

ID=42224639

Family Applications (1)

Application Number Title Priority Date Filing Date
EP10150609A Withdrawn EP2226494A1 (fr) 2009-03-02 2010-01-13 Injecteur de carburant doté d'un actionneur piézoélectrique et d'un coupleur hydraulique

Country Status (2)

Country Link
EP (1) EP2226494A1 (fr)
DE (1) DE102009001266A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012123134A1 (fr) * 2011-03-11 2012-09-20 Robert Bosch Gmbh Procédé et dispositif de remplissage et de contrôle de l'étanchéité d'un injecteur de carburant

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015226373A1 (de) 2015-12-21 2017-06-22 Robert Bosch Gmbh Kraftstoffinjektor
DE102015226427A1 (de) 2015-12-22 2017-06-22 Robert Bosch Gmbh Kraftstoffinjektor
DE102015226576A1 (de) 2015-12-22 2017-06-22 Robert Bosch Gmbh Kraftstoffinjektor
DE102016206261A1 (de) 2016-04-14 2017-10-19 Robert Bosch Gmbh Kraftstoffinjektor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10037527A1 (de) 1999-08-02 2001-02-15 Denso Corp Piezoelektrische Einspritzeinrichtung
DE10326045A1 (de) * 2003-06-10 2004-12-30 Robert Bosch Gmbh Einspritzdüse für Brennkraftmaschinen

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10037527A1 (de) 1999-08-02 2001-02-15 Denso Corp Piezoelektrische Einspritzeinrichtung
DE10326045A1 (de) * 2003-06-10 2004-12-30 Robert Bosch Gmbh Einspritzdüse für Brennkraftmaschinen
EP1636480A1 (fr) * 2003-06-10 2006-03-22 Robert Bosch Gmbh Injecteur pour moteurs a combustion interne

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012123134A1 (fr) * 2011-03-11 2012-09-20 Robert Bosch Gmbh Procédé et dispositif de remplissage et de contrôle de l'étanchéité d'un injecteur de carburant
US9097245B2 (en) 2011-03-11 2015-08-04 Robert Bosch Gmbh Method and device for refilling and checking the leak-tightness of a fuel injector

Also Published As

Publication number Publication date
DE102009001266A1 (de) 2010-09-09

Similar Documents

Publication Publication Date Title
EP2108080B1 (fr) Injecteur pour injecter du carburant dans les chambres de combustion des moteurs à combustion interne
DE10229417A1 (de) Speichereinspritzsystem mit Variodüse und Druckübersetzungseinrichtung
EP0976924B1 (fr) Injecteur avec une servovalve
EP1520100B1 (fr) Dispositif permettant d'amortir la course de l'aiguille sur des injecteurs de carburant commandes par pression
EP2235356B1 (fr) Injecteur de carburant
EP2226494A1 (fr) Injecteur de carburant doté d'un actionneur piézoélectrique et d'un coupleur hydraulique
EP2156050B1 (fr) Système d'amplification de pression pour au moins un injecteur de carburant
WO2009141182A1 (fr) Injecteur de carburant
EP2275666B1 (fr) Injecteur de carburant doté d'une soupape de distribution à pression compensée
EP2022975B1 (fr) Injecteur
EP1334271B1 (fr) Injecteur commande par course/et pression et pourvu d'un double piston
EP2204571B1 (fr) Injecteur de carburant doté d'un actionneur piézoélectrique
WO2003074865A1 (fr) Systeme pour moduler en pression le comportement d'injection
DE10315489B3 (de) Kraftstoffinjektor mit Druckübersetzer und in ein Düsenmodul integriertem Dämpfungskolben
EP3184802B1 (fr) Injecteur de carburant
EP2136067A1 (fr) Injecteur de carburant
EP3184803B1 (fr) Injecteur de carburant
WO2000017511A1 (fr) Dispositif d'injection de carburant destine a des moteurs a combustion interne
EP2204570B1 (fr) Injecteur de carburant
DE102007001365A1 (de) Injektor mit Steuer- und Schaltkammer
EP1606511B1 (fr) Dispositif d'injection de carburant pour moteur a combustion interne
WO2010081576A1 (fr) Injecteur de carburant
EP2085604A1 (fr) Injecteur de carburant
WO2008148632A1 (fr) Injecteur à soupape de commande
DE102005029805A1 (de) Kraftstoffinjektor mit Verzögerungseinrichtung zur Verlängerung der Druckverstärkungsphase

Legal Events

Date Code Title Description
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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): 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 SE SI SK SM TR

AX Request for extension of the european patent

Extension state: AL BA RS

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20110309