EP1070844A1 - Einspritzventil für Brennkraftmaschinen - Google Patents

Einspritzventil für Brennkraftmaschinen Download PDF

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Publication number
EP1070844A1
EP1070844A1 EP00115462A EP00115462A EP1070844A1 EP 1070844 A1 EP1070844 A1 EP 1070844A1 EP 00115462 A EP00115462 A EP 00115462A EP 00115462 A EP00115462 A EP 00115462A EP 1070844 A1 EP1070844 A1 EP 1070844A1
Authority
EP
European Patent Office
Prior art keywords
needle element
bar
injector
piezoelectric
actuator
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Withdrawn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
EP00115462A
Other languages
English (en)
French (fr)
Inventor
Francesco Butera
Stefano Alacqua
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.)
Centro Ricerche Fiat SCpA
Original Assignee
Centro Ricerche Fiat SCpA
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 Centro Ricerche Fiat SCpA filed Critical Centro Ricerche Fiat SCpA
Publication of EP1070844A1 publication Critical patent/EP1070844A1/de
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • 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
    • 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
    • F02M2200/701—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger mechanical
    • 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

Definitions

  • the present invention relates to an injector for internal-combustion engines, in particular for petrol engines and diesel engines for motor vehicles.
  • an injector of the type comprising:
  • the actuator device consists of an electromagnet, which, when excited, generates a force that recalls the needle element towards the inside of the base body, towards a position of opening of the valve seat.
  • injectors in which the actuator device comprises a bar made of piezoelectric material set parallel to the direction of sliding of the needle element.
  • the piezoelectric actuator when activated, it applies a force to the needle element, which tends to push the latter towards the outside of the base body, against the action of elastic means that tend to recall the needle element towards the inside of the base body into a position in which a widened head of the needle element closes the valve seat.
  • injectors provided with piezoelectric-type actuator devices present the advantage of being able to operate with higher fluid pressures, as compared to injectors provided with electromagnetic actuator devices.
  • injectors for petrol-driven engines with electromagnetic actuators can operate with a fluid pressure of up to 120 bar
  • injectors with piezoelectric actuators can operate with a fluid pressure of up to 300 bar.
  • the injectors with piezoelectric actuators of the known type have larger overall dimensions and higher costs, a poorer quality of the jet of fluid, and present more problems as regards the mechanical connection (interface) between the actuator device and the needle element.
  • the present invention sets itself the aim of providing an injector of the type specified at the beginning of the present invention, that makes it possible to overcome the aforesaid drawbacks.
  • the said purpose is achieved by providing an injector having the characteristics specified in the main claim.
  • the number 10 designates an injector for petrol-driven engines, comprising a base body 12 having a cavity 14, into which, in use, petrol under pressure is fed by means of an inlet connection designed to be connected to a fuel-supply pipe (not illustrated).
  • the base body 12 has a tubular end 18 in which a valve seat 20 communicating with an injection hole is made.
  • a needle element 22 is mounted in such a way that it is can slide inside the base body 12 in the direction of its own longitudinal axis 24.
  • a helical spring in compression 26 pushes the needle element 22 towards a position of closing of the valve seat 20.
  • the injector 20 comprises an amplified piezoelectric actuator 28 connected to the needle element 22.
  • the amplified piezoelectric actuator 28 is in itself known and may be, for example, of the type manufactured by the company CEDRAD RICERCHE, distinguished by the code APA, Series S or Series M.
  • the actuator device comprises a bar 30 made of piezoelectric material, which extends in a direction orthogonal to the axis 24 of the needle element 22.
  • the bar 30 made of piezoelectric material co-operates with an amplifying structure 32 having two connection points 34, 36 set in line along the axis 24.
  • connection point 34 has the function of fixing the amplifying structure 32 to the base body 12, and the connection point 36 has the function of connecting the amplifying structure 32 to the needle element 22.
  • An electrical connector 38 electrically connects the bar 30 of piezoelectric material to a conventional-type control unit.
  • the actuator 28 When the bar 30 of piezoelectric material is deenergized, the actuator 28 is in a resting condition, and the needle element 22 is in a position in which it closes the valve seat 20, the spring 26 having a small load, sufficient for recovery of ?play.
  • the bar 30 of piezoelectric material undergoes electrical excitation, it dilates in the direction of its own longitudinal axis and deforms the amplifying structure 32.
  • the structure 32 applies a force on the needle element 22 in the direction indicated by the arrow 40 in Figure 1. This force causes a displacement of the needle element 22 against the action of the spring 26, towards a position of opening of the valve seat 20.
  • the amplified piezoelectric actuator device 28 presents all the advantages intrinsic in piezoelectric technology, among which displacement proportional to the electric voltage applied, fast response times, and small power consumption.
  • the actuator 28 is moreover less costly and cumbersome than direct piezoelectric actuators.
  • an amplified piezoelectric actuator 28 having dimensions 2 cm x 1 cm has a stroke of 50 ⁇ m and applies a force of 50 N, whilst a direct piezoelectric actuator of equal performance would have overall dimensions of approximately 60-90 mm.
  • the amplified piezoelectric actuator 28 enables a needle actuator to be used of a type identical to the one present in injectors with electromagnetic-type actuator devices, in which the needle element is recalled towards the inside of the base body 12 by the force produced by the actuator device. This makes it possible to achieve a jet quality that is typical of electromagnetic injectors, that is, a jet quality that is superior to the one achievable with injectors provided with direct piezoelectric actuators.
  • the present invention may be applied also to injectors for diesel engines.
  • the items corresponding to the ones previously described are designated by the same reference numbers.
  • Injectors for diesel fuel work at pressures decidedly higher than those of injectors for petrol (for example, of the order of 1500 bar).
  • the needle element 22 does not control opening of the injection hole directly, but opens a control valve 40.
  • a rod 42 slides upwards, opening an injection hole 44, in a way in itself known.
  • the needle element 22 is made in a monolithic way (for example co-moulded) with the amplifying structure 32 of the piezoelectric actuator 28.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP00115462A 1999-07-20 2000-07-18 Einspritzventil für Brennkraftmaschinen Withdrawn EP1070844A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT1999TO000642 IT1310126B1 (it) 1999-07-20 1999-07-20 Attuatore piezoelettrico per l'iniezione di carburante
ITTO990642 1999-07-20

Publications (1)

Publication Number Publication Date
EP1070844A1 true EP1070844A1 (de) 2001-01-24

Family

ID=11417983

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00115462A Withdrawn EP1070844A1 (de) 1999-07-20 2000-07-18 Einspritzventil für Brennkraftmaschinen

Country Status (2)

Country Link
EP (1) EP1070844A1 (de)
IT (1) IT1310126B1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2836536A1 (fr) 2002-02-26 2003-08-29 Cedrat Technologies Vanne piezoelectrique
DE10216084A1 (de) * 2002-04-11 2003-10-30 Vemac Gmbh & Co Kg Vergaser für Otto-Motor mit einstellbarer Brennstoffdüse
US9455394B2 (en) 2011-02-07 2016-09-27 Murata Manufacturing Co., Ltd. Displacement member, driving member, actuator, and driving device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE695974C (de) * 1937-06-22 1940-09-16 Auto Union A G Verfahren zum elektrischen Steuern der Duesennadel bei Einspritzventilen
US4022166A (en) * 1975-04-03 1977-05-10 Teledyne Industries, Inc. Piezoelectric fuel injector valve
US4720077A (en) * 1985-12-28 1988-01-19 Aisan Kogyo Kabushiki Kaisha Fuel injection valve
JPH02112664A (ja) * 1989-09-20 1990-04-25 Hitachi Ltd 圧電式燃料噴射弁
JPH1082352A (ja) * 1996-09-09 1998-03-31 Hitachi Ltd 筒内燃料噴射装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE695974C (de) * 1937-06-22 1940-09-16 Auto Union A G Verfahren zum elektrischen Steuern der Duesennadel bei Einspritzventilen
US4022166A (en) * 1975-04-03 1977-05-10 Teledyne Industries, Inc. Piezoelectric fuel injector valve
US4720077A (en) * 1985-12-28 1988-01-19 Aisan Kogyo Kabushiki Kaisha Fuel injection valve
JPH02112664A (ja) * 1989-09-20 1990-04-25 Hitachi Ltd 圧電式燃料噴射弁
JPH1082352A (ja) * 1996-09-09 1998-03-31 Hitachi Ltd 筒内燃料噴射装置

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 014, no. 331 (M - 0999) 17 July 1990 (1990-07-17) *
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 08 30 June 1998 (1998-06-30) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2836536A1 (fr) 2002-02-26 2003-08-29 Cedrat Technologies Vanne piezoelectrique
US6994110B2 (en) 2002-02-26 2006-02-07 Cedrat Technologies Piezoelectric valve
DE10216084A1 (de) * 2002-04-11 2003-10-30 Vemac Gmbh & Co Kg Vergaser für Otto-Motor mit einstellbarer Brennstoffdüse
US9455394B2 (en) 2011-02-07 2016-09-27 Murata Manufacturing Co., Ltd. Displacement member, driving member, actuator, and driving device

Also Published As

Publication number Publication date
IT1310126B1 (it) 2002-02-11
ITTO990642A1 (it) 2001-01-20

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