WO1998049443A1 - Dispositif d'injection de carburant pour moteur a combustion interne - Google Patents
Dispositif d'injection de carburant pour moteur a combustion interne Download PDFInfo
- Publication number
- WO1998049443A1 WO1998049443A1 PCT/FR1998/000778 FR9800778W WO9849443A1 WO 1998049443 A1 WO1998049443 A1 WO 1998049443A1 FR 9800778 W FR9800778 W FR 9800778W WO 9849443 A1 WO9849443 A1 WO 9849443A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- fuel
- injection device
- injector
- fuel injection
- nozzle
- Prior art date
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 88
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 19
- 238000002347 injection Methods 0.000 claims abstract description 55
- 239000007924 injection Substances 0.000 claims abstract description 55
- 230000010355 oscillation Effects 0.000 claims abstract description 9
- 125000004122 cyclic group Chemical group 0.000 claims abstract description 8
- 230000009471 action Effects 0.000 claims description 6
- 239000002828 fuel tank Substances 0.000 claims description 4
- 230000010358 mechanical oscillation Effects 0.000 claims description 2
- 230000001105 regulatory effect Effects 0.000 claims 1
- 238000005452 bending Methods 0.000 description 9
- 239000007788 liquid Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000033001 locomotion Effects 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 239000012528 membrane Substances 0.000 description 3
- 238000009834 vaporization Methods 0.000 description 3
- 230000008016 vaporization Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 210000000887 face Anatomy 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000005499 meniscus Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 210000001331 nose Anatomy 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 210000003128 head Anatomy 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
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
- F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
-
- 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
- F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
- F02M69/04—Injectors peculiar thereto
- F02M69/041—Injectors peculiar thereto having vibrating means for atomizing the fuel, e.g. with sonic or ultrasonic vibrations
-
- 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
- F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
- F02M69/04—Injectors peculiar thereto
- F02M69/042—Positioning of injectors with respect to engine, e.g. in the air intake conduit
- F02M69/044—Positioning of injectors with respect to engine, e.g. in the air intake conduit for injecting into the intake conduit downstream of an air throttle valve
Definitions
- the present invention relates to a fuel injection device for an internal combustion engine intended in particular to equip a motor vehicle.
- the invention relates more particularly to a fuel injection device using a piezoelectric actuator to atomize the fuel injected in the form of very fine droplets.
- the fuel injection devices used today on internal combustion engines fitted to motor or road vehicles conventionally operate on the model of a valve, the open or closed state of which is continuously controlled, the dosage of the injected fuel then done directly by the opening time.
- Such injection systems include an electric fuel supply pump which supplies, via a distribution manifold, all of the injectors under a pressure having a constant difference with the pressure prevailing in the intake manifold. through a pressure regulator.
- an electric fuel supply pump which supplies, via a distribution manifold, all of the injectors under a pressure having a constant difference with the pressure prevailing in the intake manifold. through a pressure regulator.
- the electromagnet actuating the valve of each injector By electronically controlling the electromagnet actuating the valve of each injector, the start and the opening time of the latter are controlled and a precise flow of fuel is determined for each of the injectors, thus the quantity of fuel injected depends only the opening time of the electro-injectors.
- the injectors of the electromagnetically controlled needle type which are the most commonly used, however have limits which hinder the improvement of engine performance, in particular in terms of pollution control.
- the times taken to open or close the needles are still too high, around 1 to 2 ms, which prevents the injection from being distributed correctly over the entire opening time of the valve.
- the minimum opening time which determines the minimum dose of fuel that can be injected, is still too long for certain engine operating points.
- Known needle injectors also have injection holes of relatively large diameters to allow the delivery of the required quantities of fuel for operations at full load and high engine speeds. This arrangement generates fuel jets having drops of large dimensions, which slows down the vaporization of the fuel (and therefore the preparation of the fuel mixture) and is capable of promoting the phenomenon of wall wetting.
- the non-vaporized fuel tends to settle on the walls of the intake duct or the combustion chamber (by direct injection).
- Such a deposit causes metering problems, particularly acute in the transients due to a lack of knowledge of the amount of fuel which actually enters the corresponding combustion chamber.
- This phenomenon of wall wetting is one of the major causes of high pollutant emissions during cold engine starts.
- the object of the present invention is therefore to solve all of these problems by proposing an injection device capable of delivering a cloud of fuel drops whose sizes are perfectly calibrated to ensure precise metering and sufficiently small to ensure the complete and homogeneous spraying of the injected fuel.
- the fuel injection device for an internal combustion engine is of the type comprising an injector connected to a fuel supply circuit under a suitable pressure, this injector comprising an injection nozzle at the end of which at least one fuel injection orifice is provided.
- the channels forming the injection nozzle are adapted to be supplied with fuel by capillarity.
- the injector has an elastically deformable part which cooperates with the means for cyclic vibration controlled by the electronic engine control system, the injection nozzle being secured to this deformable part.
- this elastically deformable part is formed by a chamber extending in the extension of a fuel tank to which the fuel supply circuit is connected by the 'through a pilot valve whose opening is controlled according to the filling level of said tank.
- FIG. 1 represents an overall view of the injection device according to the invention
- FIG. 3 there is seen in cross section an intake duct 12 formed through the cylinder head 16 of an internal combustion engine of the multicylinder type with spark ignition.
- This duct 12 opens out through an inlet orifice on the underside of the cylinder head 16 defining the roof of a combustion chamber 15.
- This inlet orifice conventionally serves as a seat for a stem valve 13 slidably mounted in a housed guide in the cylinder head 16.
- the opening of the valve 13 is controlled by suitable means, not shown, such as a camshaft.
- the fuel supply to the engine is of the electronically controlled multipoint type by which each combustion chamber 15 is supplied with fuel by at least one fuel injector 1.
- the injector 1 extends, according to the particular embodiment shown, directly into one of the intake ducts serving the combustion chamber 15, in this case the duct 12.
- the injector 1 is arranged so that its ejection nozzle 8 is directed towards the head of the valve 13 in order to direct the jet of fuel 11 directly into the combustion chamber 15 through the intake orifice, when the opening of the valve 13.
- the body of the injector 1 is fixed in the cylinder head 16 by its end upper, which is also connected to a fuel supply line 2.
- the injector body comprises, in its upstream part in the direction of flow of the fuel, a buffer tank 4 having a membrane 5 for pressurizing.
- This tank 4 is supplied by a line 2 for supplying the fuel under a suitable pressure.
- an electrically controlled valve 3 whose function is to control the filling level of the tank 4.
- the tank is kept filled by controlling the valve 3.
- the valve 3 When the quantity of fuel in the tank 4 falls below a given threshold, detected by a sensor not shown here, the valve 3 is then opened until the filling of the tank 4 at the required threshold, then valve 3 is closed again.
- the variations in volume in the tank 4 due to the quantities of fuel ejected through the orifices 10 and to the quantities of fuel passing through the valve 3 are sufficiently small compared to the total volume of the tank 4 so that the variations in pressure can be compensated by the pressurizing membrane 5.
- the shape of the chamber 7, between points A and D, and the nature of the materials used for the production of its walls, are therefore adapted so as to generate, under the action of the cyclic pressurization means 6, an oscillation of the nozzle 8 whose amplitude is maximum at the orifices 10 of the channels 9.
- the piezoelectric plate 6 is secured to the wall of the chamber 7 by gluing and its electrodes are formed by two parallel faces, l 'one (AD) being in contact with one injector at the wall of the chamber 7 and the other (CB) having its free surface.
- the piezoelectric plate 6 is polarized in a direction perpendicular to the electrodes, so that when a voltage is applied between these electrodes, by necking effect the piezoelectric plate 6 stretches in its two planar directions, the state of stress on the two faces being different this has the effect of creating a bending of the plate which results locally in a change of curvature of the wall of the chamber 7.
- the bending of the wall of the chamber 7 causes in bending the part 8 of the body 1, namely the injection nozzle, with maximum displacement at its end 14 at the orifices 10.
- the displacement generated at the end of the nozzle 14 makes it possible to expel through each orifice 10 a micro-quantity of liquid which gives rise to a drop 11 ejected with a certain speed.
- each cycle of electric voltage applied to the piezoelectric plate 6 it passes through two symmetrical bending deformation states which causes the end of the nozzle 14 to oscillate between two symmetrical positions E and F linked to an amplitude given oscillation.
- the fuel drops are ejected.
- two drops of fuel are ejected per orifice.
- the ejection of the drops through the orifices 10 at the end 14 of the nozzle 8 is effected by the sole action of the oscillatory movement in bending of the latter.
- Oscillating movement in bending which causes on the one hand a local overpressure in the liquid at the level of the nozzle and on the other hand a setting in motion of the same liquid confined in the nozzle, the two effects contributing simultaneously to the formation and to the ejection of the drops.
- the shape of the injector 1 and more particularly of the nozzle 8, is therefore suitable for obtaining a natural amplification of the movement.
- the beam structure of the channels 9 perfectly meets this objective. Likewise, it is important that the structure chosen can reach high resonant frequencies allowing the injection of a high number of drops of fuel per second.
- the injector according to the invention therefore operates without a valve since the channels 9 open freely to the atmosphere, the retention of the liquid in the nozzle 8 operating simply by virtue of the surface tension of the liquid and the action of the capillary forces.
- a liquid meniscus is thus naturally formed on each orifice 10 of the nozzle 8, a meniscus which prevents the flow of fluid as long as the pressure difference between the liquid contained in the nozzle and the surrounding atmosphere does not exceed a given value.
- the injection device comprises a body 1 which in its part supporting the piezoelectric plate 6 measures 1 millimeter in total and about 1 centimeter in its width and its length, the nozzle has a length close to 20 millimeters and a thickness of the order of 0.2 millimeters at its end where is located a row of circular orifices 10 30 microns in diameter.
- a double beam of drops with excitation frequencies ranging from 40 kH to 400 kH, and this for an applied alternating voltage of the order of 10 volts peak.
- the diameter of the drops is a function of the amplitude of the applied voltage and the operating frequency.
- the speed of the drops depending on the operating point chosen varies from 5 to 15 meters per second.
- the response time of the device for an oscillation of the nozzle and the simultaneous ejection of drops of fuel is approximately 10 microseconds.
- a device operating at 250 kH has 170 orifices 10 of 30 microns in diameter at the end of the nozzle.
- This flow assists the ejection of fuel and drives the drops which are ejected in a bundle of the orifices 10 to propel them directly into the chamber 15 through the opening of the valve.
- the difference between the ejection speed of the drops, between 5 and 10 meters per second and that of the air flow, causes abrasion of the fuel drops and contributes to their evaporation.
- the injection orifices can be circular, square or any other geometric shape, the transverse dimensions of the orifices being able to be reduced to a few microns, for example of the order of ten to thirty microns .
- the section of the orifices makes it possible to calibrate the size of the drops formed, the calibration of the size of the drops can then be modified by varying the amplitude of oscillation of the nozzle.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP98921556A EP0977946A1 (fr) | 1997-04-25 | 1998-04-17 | Dispositif d'injection de carburant pour moteur a combustion interne |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9705129A FR2762648B1 (fr) | 1997-04-25 | 1997-04-25 | Dispositif d'injection de carburant pour moteur a combustion interne |
FR97/05129 | 1997-04-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998049443A1 true WO1998049443A1 (fr) | 1998-11-05 |
Family
ID=9506310
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR1998/000778 WO1998049443A1 (fr) | 1997-04-25 | 1998-04-17 | Dispositif d'injection de carburant pour moteur a combustion interne |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0977946A1 (fr) |
FR (1) | FR2762648B1 (fr) |
WO (1) | WO1998049443A1 (fr) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003334479A (ja) * | 2001-10-02 | 2003-11-25 | Ngk Insulators Ltd | 液体噴射装置 |
FR2879046B1 (fr) | 2004-12-08 | 2007-10-26 | Renault Sas | Procede de commande d'un circuit de pilotage pour des actionneurs piezostrictifs ou magnotostrictifs |
DE102006026153A1 (de) * | 2006-06-06 | 2007-12-13 | Robert Bosch Gmbh | Sprüheinrichtung für Fluide |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2029207A1 (de) * | 1970-06-13 | 1971-12-16 | Daimler Benz Ag | Ultraschall Koppelschwinger |
JPS59201962A (ja) * | 1983-04-28 | 1984-11-15 | Matsushita Electric Ind Co Ltd | 霧化装置 |
EP0361480A1 (fr) * | 1988-09-29 | 1990-04-04 | Siemens Aktiengesellschaft | Buse d'injection de combustible à commande de caractéristique du jet de combustible pour moteur à combustion interne |
US5437255A (en) * | 1994-03-15 | 1995-08-01 | Sadley; Mark L. | Fuel injection sytem employing solid-state injectors for liquid fueled combustion engines |
-
1997
- 1997-04-25 FR FR9705129A patent/FR2762648B1/fr not_active Expired - Fee Related
-
1998
- 1998-04-17 EP EP98921556A patent/EP0977946A1/fr not_active Withdrawn
- 1998-04-17 WO PCT/FR1998/000778 patent/WO1998049443A1/fr not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2029207A1 (de) * | 1970-06-13 | 1971-12-16 | Daimler Benz Ag | Ultraschall Koppelschwinger |
JPS59201962A (ja) * | 1983-04-28 | 1984-11-15 | Matsushita Electric Ind Co Ltd | 霧化装置 |
EP0361480A1 (fr) * | 1988-09-29 | 1990-04-04 | Siemens Aktiengesellschaft | Buse d'injection de combustible à commande de caractéristique du jet de combustible pour moteur à combustion interne |
US5437255A (en) * | 1994-03-15 | 1995-08-01 | Sadley; Mark L. | Fuel injection sytem employing solid-state injectors for liquid fueled combustion engines |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 009, no. 070 (M - 367) 30 March 1985 (1985-03-30) * |
Also Published As
Publication number | Publication date |
---|---|
FR2762648B1 (fr) | 1999-06-04 |
EP0977946A1 (fr) | 2000-02-09 |
FR2762648A1 (fr) | 1998-10-30 |
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