EP0234642A1 - Elektromagnetischer Injektor für Brennkraftmaschine - Google Patents

Elektromagnetischer Injektor für Brennkraftmaschine Download PDF

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Publication number
EP0234642A1
EP0234642A1 EP87200212A EP87200212A EP0234642A1 EP 0234642 A1 EP0234642 A1 EP 0234642A1 EP 87200212 A EP87200212 A EP 87200212A EP 87200212 A EP87200212 A EP 87200212A EP 0234642 A1 EP0234642 A1 EP 0234642A1
Authority
EP
European Patent Office
Prior art keywords
grooves
section
injector
injection nozzle
decreasing cross
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.)
Granted
Application number
EP87200212A
Other languages
English (en)
French (fr)
Other versions
EP0234642B1 (de
Inventor
Alessandro Facchin
Alberto Manetti
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.)
Weber SRL
Original Assignee
Weber SRL
Spica SpA
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 Weber SRL, Spica SpA filed Critical Weber SRL
Publication of EP0234642A1 publication Critical patent/EP0234642A1/de
Application granted granted Critical
Publication of EP0234642B1 publication Critical patent/EP0234642B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/06—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves being furnished at seated ends with pintle or plug shaped extensions
    • 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
    • F02M51/061—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means
    • F02M51/0625—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures
    • F02M51/0664—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a cylindrically or partly cylindrically shaped armature, e.g. entering the winding; having a plate-shaped or undulated armature entering the winding
    • F02M51/0667—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a cylindrically or partly cylindrically shaped armature, e.g. entering the winding; having a plate-shaped or undulated armature entering the winding the armature acting as a valve or having a short valve body attached thereto
    • 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

Definitions

  • This invention relates to an electromagnetically operated injector for use in electronically controlled fuel injection systems, of the single or multiple injector type, for internal combustion engines.
  • This type of injector characteristically comprises a casing, a fuel inlet in said casing, fuel discharge elements complete with at least partly magnetic valve means for controlling the fuel flow through said discharge elements, and a solenoid contained in said casing and which, when energised, causes said valve means to open in opposition to elastic means, and thus allow the fuel to flow through said discharge elements.
  • One of the main characteristics to be considered in designing this type of electromagnetic injector is the shape of the jet leaving the bore in the injection nozzle. In this respect, this shape often differs according to the position of the injector on the engine.
  • an atomised conical spray can be desirable to facilitate the mixing of the petrol with the air drawn in by the engine.
  • the conical jet is obtained by using a typical injector configuration for diesel engines with a precombustion chamber.
  • This conventional method is shown in Figure 1, and comprises a cylindrical pin element which, joined coaxially to the mobile valve element and contained in a bore provided in the fixed valve body, acts as a sizing means for the fuel discharge area, and terminates in a double cone reverberator the purpose of which is to widen the jet leaving the metering section.
  • a different method provides a vortexing element in the form of a disc with oblique bores which, disposed immediately upstream of the valve means, causes the fuel to undergo a vortex movement before the fluid reaches the outlet bore.
  • the discharge coefficient at said seat tends to reduce and therefore an increase in the stroke of travel of the mobile valve means is required in order to ensure that the flow does not become throttled at the passage area in the seat. This increases the time required by the mobile member to undergo its stroke of travel, leading to a higher speed of impact between said mobile member and the cooperating abutment element, with the consequent possibility that the mobile valve means rebounds to produce relative instability in fuel delivery.
  • a further serious drawback of this method is the fact that the fuel present between the vortexing element and the sealing seat is injected without the vortex effect at the commencement of each injection cycle.
  • This volume of liquid which is considerable percentage-wise at low delivery, creates difficulties in handling the flow because of the different discharge coefficients at the seat and at the injector discharge bore, and this gives rise in the jet to a considerable compact pre-spray in the shape of a cylindrical rod, which particularly under idling conditions causes increase in the pollutants emitted by the engine.
  • a further method proposed in two different inventions (US 4,487,369 and US 4,520,962) provides downstream of the valve means a helically grooved element press-fitted into the injection nozzle body.
  • a recent invention obtains jet atomisation by positioning downstream of the injection nozzle discharge bore a shield-shaped element against which the jet strikes, to undergo break-down.
  • This system which had been formerly used in diesel injection, is however very difficult to handle when used in mass-production, from the point of view of directing the broken-down jet into the engine intake duct and obtaining uniformity in the degree of atomisation because of the extreme sensitivity of these two parameters to the dynamics of the impact between the rod-shaped cylindrical jet leaving the injector and the shield-shaped element on which it is broken down.
  • the object of the present invention is therefore to obtain, in a simple manner and under low production costs, an electromagnetic injector which creates an atomised conical jet and which obviates the drawbacks of the known art.
  • an electromagnetic conical jet injector which:
  • an electromagnetically operated injector for feeding fuel to an internal combustion engine, comprising a casing, a fuel inlet in said casing, fuel discharge elements terminating with an injection nozzle, said discharge elements being complete with at least partly ferromagnetic valve means for controlling the fuel flow through said elements, and a solenoid contained in said casing in order, when energised, to cause said valve means to open in opposition to elastic means, characterised in that in the surface which defines the terminal bore of said injection nozzle, through which the fuel flows for its injection into the engine, there are formed one or more grooves which open into an inner chamber faces by said shut-off valve means, and are of gradually decreasing cross-section in the direction away from said inner chamber.
  • an injector according to the present invention has the following advantages:
  • an electromagnetic injector of the type according to the invention comprises a central cylindrical core 10 of ferromagnetic material housed in a casing 11, also of ferromagnetic material, and extending outside the casing 11 to form a connector 10a for connecting the injector to the fuel feed.
  • a ferromagnetic mobile armature 12 is coaxially associated with the core 10 to form a magnetic circuit together with the core 10 and casing 11.
  • the core is at least partly surrounded by a coil 13 wound on a spool 14, and fed electrically in known manner under intermittent control by conductors 15 partly embedded in a plastics cap 16.
  • the mobile armature 12 substantially of hollow cylindrical shape, carries a shut-off element 17 by way of a washer 18, and is guided by a tube 19 inserted into the core 10 but projecting from it.
  • a spring 20 normally urges the shut-off element 17 against a ledge of an injection nozzle 21, which is provided in known manner with a sized bore for fuel discharge.
  • the spring 20 reacts against a dowel 22 inserted with an interference fit into the core 10 and open centrally to allow the fuel to pass.
  • annular spacer 23 which substantially defines the stroke of the armature 12, which at the end facing the core 10 abuts against an annular abutment element 24, which is of impact-resistant material and at least partly amagnetic, and is mounted on the core 10 in such a manner as to project axially from the end of the core 10 to leave a small air gap between the armature 12 and core 10 when the armature is in its completely raised position, in which the shut-off element 17 opens the passage through the nozzle 21.
  • the annular abutment element 24 ensures that there is no mechanical and/or hydraulic sticking, which would be prejudicial to instantaneous injector shut-off action.
  • the hydraulic seal is provided by seal rings 25, 26 and 29.
  • the fuel fed through the dowel 22, reaches the bores 27 of the core 10 in known manner, and then the bores 28 in the armature 12, from which the fuel reaches the outside of the nozzle 21.
  • the armature 12 is in its lowered position in which the shut-off element 17 shuts off the fuel passage through the nozzle 21, whereas when the coil 13 is energised, the armature 12 is in its raised position in contact with the annular abutment element 24, the shut-off element 17 opening the fuel passage through the injection nozzle 21.
  • the terminal zone of the injection nozzle 21 is formed, as shown in Figure 3, by a bore 30 the surface of which is provided with one or more grooves 31 of substantially longitudinal extension, which open into the inner chamber 32 which faces the shut-off valve means 17.
  • Said one or more grooves 31 characteristically have a cross-section which gradually decreases in the direciton away from the inner chamber 32, and can terminate either within the interior of the discharge bore 30 as shown in Figure 3, or can open, at their end distant from the inner chamber 32, into the outer surface 33 of the injection nozzle 21 into which the fuel discharge bore 30 opens, as shown in Figure 9.
  • the grooves 31 of decreasing cross-section cause the formation, within the liquid mass leaving the injector at the moment the valve means open, of fluid fillets of preferential path which by virtue of the proximity of the grooves at the outlet surface 33, cause the fuel injection jets to open out and to break down into droplets of very small size.
  • the injection cone angle and the fuel distribution over the cross-section transverse to the jet axis depend on the dimensional characteristics and number of the grooves 31 of decreasing cross-section.
  • discharge coefficient uniformity of the fuel discharge bore in the injection nozzle 21 can be maintained by controlling the dimension H ( Figure 3) at which the grooves 31 are positioned with respect to the outer surface 33 of the nozzle 21 into which said discharge bore opens.
  • Figure 3, 4, 5 and 6 show grooves 31 of substantially triangular cross-section. Other shapes can be used without appreciable change in their functional performance.
  • the groove or grooves 31 can be of substantially rectangular or semi-­circular cross-section, as shown in Figures 7 and 8 respectively.
  • Figures 3, 4, 5, 7, 8 and 9 show grooves 31 of substantially rectilinear extension, with their longitudinal axis coplanar with the axis of the fuel discharge bore in the injection nozzle. These grooves can however be made with their axis oblique to the axis of the nozzle discharge bore ( Figure 6) in order to create in the fluid mass a tangential component which favours the formation of the atmoised conical spray.
  • the grooves 31 can be of curved extension, for example as shown in Figure 10.
  • An even number or odd number of grooves 31 can be provided, and they are preferably distributed angularly equidistant on the surface of the terminal bore 30 of the injection nozzle.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Fuel-Injection Apparatus (AREA)
EP87200212A 1986-02-18 1987-02-11 Elektromagnetischer Injektor für Brennkraftmaschine Expired - Lifetime EP0234642B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT1944586 1986-02-18
IT8619445A IT1213039B (it) 1986-02-18 1986-02-18 Combustione interna. iniettore ad azionamento elettromagnetico per motori a

Publications (2)

Publication Number Publication Date
EP0234642A1 true EP0234642A1 (de) 1987-09-02
EP0234642B1 EP0234642B1 (de) 1990-04-11

Family

ID=11158052

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87200212A Expired - Lifetime EP0234642B1 (de) 1986-02-18 1987-02-11 Elektromagnetischer Injektor für Brennkraftmaschine

Country Status (3)

Country Link
EP (1) EP0234642B1 (de)
DE (1) DE3762262D1 (de)
IT (1) IT1213039B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997033086A1 (en) * 1996-03-04 1997-09-12 Jerzy Chomiak Orifice shape of a fuel injector
US5836521A (en) * 1995-03-09 1998-11-17 Dysekompagniet I/S Valve device with impact member and solenoid for atomizing a liquid

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE285330C (de) *
FR529508A (fr) * 1915-06-26 1921-11-29 Ruston And Hornsby Ltd Perfectionnements dans les dispositifs pour atomiser des combustibles liquides dans les moteurs à combustion interne
FR779909A (fr) * 1933-10-19 1935-04-16 Dispositif d'injection du combustible dans les moteurs à combustion interne
FR1408212A (fr) * 1963-05-01 1965-08-13 Ass Eng Ltd Clapets d'injection de carburant
FR2447471A1 (fr) * 1979-01-23 1980-08-22 Maschf Augsburg Nuernberg Ag Injecteur de combustible pour moteurs a combustion interne
DE3012416A1 (de) * 1980-03-29 1981-10-15 Robert Bosch Gmbh, 7000 Stuttgart Einspritzventil
DE3415905A1 (de) * 1984-04-28 1985-11-07 Daimler-Benz Ag, 7000 Stuttgart Lochduese fuer brennkraftmaschine mit direkteinspritzung

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3023757A1 (de) * 1980-06-25 1982-01-21 Robert Bosch Gmbh, 7000 Stuttgart Einspritzventil
JPS57126554A (en) * 1981-01-30 1982-08-06 Hitachi Ltd Electro magnetic fuel jet valve
DE3151020A1 (de) * 1981-12-23 1983-07-28 Robert Bosch Gmbh, 7000 Stuttgart Einspritzventil
US4487369A (en) * 1982-01-11 1984-12-11 Essex Group, Inc. Electromagnetic fuel injector with improved discharge structure
GB2136500A (en) * 1983-03-16 1984-09-19 Lucas Ind Plc Electromagnetic fuel injector
GB2144178B (en) * 1983-07-28 1987-03-25 Lucas Ind Plc I.c. engine fuel injector

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE285330C (de) *
FR529508A (fr) * 1915-06-26 1921-11-29 Ruston And Hornsby Ltd Perfectionnements dans les dispositifs pour atomiser des combustibles liquides dans les moteurs à combustion interne
FR779909A (fr) * 1933-10-19 1935-04-16 Dispositif d'injection du combustible dans les moteurs à combustion interne
FR1408212A (fr) * 1963-05-01 1965-08-13 Ass Eng Ltd Clapets d'injection de carburant
FR2447471A1 (fr) * 1979-01-23 1980-08-22 Maschf Augsburg Nuernberg Ag Injecteur de combustible pour moteurs a combustion interne
DE3012416A1 (de) * 1980-03-29 1981-10-15 Robert Bosch Gmbh, 7000 Stuttgart Einspritzventil
DE3415905A1 (de) * 1984-04-28 1985-11-07 Daimler-Benz Ag, 7000 Stuttgart Lochduese fuer brennkraftmaschine mit direkteinspritzung

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5836521A (en) * 1995-03-09 1998-11-17 Dysekompagniet I/S Valve device with impact member and solenoid for atomizing a liquid
WO1997033086A1 (en) * 1996-03-04 1997-09-12 Jerzy Chomiak Orifice shape of a fuel injector

Also Published As

Publication number Publication date
IT1213039B (it) 1989-12-07
DE3762262D1 (de) 1990-05-17
EP0234642B1 (de) 1990-04-11
IT8619445A0 (it) 1986-02-18

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