WO1999043442A1 - Pompe d'injection a pression de refermeture de l'injecteur a aiguille renforcee - Google Patents

Pompe d'injection a pression de refermeture de l'injecteur a aiguille renforcee Download PDF

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Publication number
WO1999043442A1
WO1999043442A1 PCT/US1999/003257 US9903257W WO9943442A1 WO 1999043442 A1 WO1999043442 A1 WO 1999043442A1 US 9903257 W US9903257 W US 9903257W WO 9943442 A1 WO9943442 A1 WO 9943442A1
Authority
WO
WIPO (PCT)
Prior art keywords
fuel
needle valve
chamber
spring
cage
Prior art date
Application number
PCT/US1999/003257
Other languages
English (en)
Inventor
Leon Duo
Werner Pape
Matthew G. Fox
Wilhelm Christ
Original Assignee
Diesel Technology Company
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 Diesel Technology Company filed Critical Diesel Technology Company
Publication of WO1999043442A1 publication Critical patent/WO1999043442A1/fr

Links

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
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • 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
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F02M57/022—Injectors structurally combined with fuel-injection pumps characterised by the pump drive
    • F02M57/023—Injectors structurally combined with fuel-injection pumps characterised by the pump drive 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically

Definitions

  • the present invention relates to a fuel pumping device, and more particularly to a fuel pumping device with increased needle valve closure pressure.
  • fuel is pressurized within a fuel pressurization chamber of a fuel injector body by an engine-driven cam plunger.
  • the fuel pressurization chamber is communicated with a spray tip portion of the fuel injector, whereby an increase in fuel pressure will push against a spring-loaded needle valve for opening the needle valve when the fuel pres- sure is sufficiently high to permit fuel injection to occur.
  • the needle valve will remain open for a period of time, permitting injection until the fuel pressure in the spray tip is insufficient to continue to hold the needle valve open against the force of the needle valve closure spring. Accordingly, when the pressure in the spray tip area decreases, the force of the spring will cause the needle valve to close.
  • the needle valve will close at a lower pressure than the pressure at which it opens because when the needle valve is open, the fuel pressure within the spray tip may act against the entire cross- sectional area of the needle valve, while the fuel pressure only acts against a portion of the cross- section of the needle valve immediately prior to needle valve opening. Because the needle valve closes at a lower pressure, fuel may actually be injected into the engine cylinder at a fuel pressure which is lower than desirable. At low fuel injection pressures, poor atomization of the injector fuel is achieved, which adversely affects the combustion cycle and adversely affects emissions.
  • the present invention overcomes the above- referenced shortcomings of prior art fuel pumping devices by providing a fuel pumping device with a pressure-actuated needle valve extending from a spring cage chamber including a spring which biases the needle valve in the closing direction, wherein the device includes a body forming a fuel pressurization chamber therein for building fuel pressure to open the needle valve against the spring-bias for fuel injection from a spray tip chamber, and the device is configured to close the needle valve at higher spray tip chamber pressures.
  • Increased needle valve closure pressure is achieved in the present invention by forming a fuel flow passage between the fuel pressurization chamber and the spring cage chamber for sufficiently pressurizing the spring cage chamber to assist the spring in closing the needle valve.
  • the fuel flow passage between the fuel pressurization chamber and the spring cage chamber may be - 3 -
  • the spring cage chamber is sufficiently enclosed for hydraulic pressure build-up, and the fuel flow passage is sufficiently restricted to control pressurization of the spring cage chamber.
  • the present invention provides a fuel pumping device with a pressure-actuated needle valve extending from a spring cage chamber including a spring which biases the needle valve in the closing direction, wherein the fuel pumping device is configured such that the needle valve closes at a high fuel pressure for improved fuel injection.
  • the device includes a body forming a fuel pressurization chamber therein for building fuel pressure to open the needle valve against the spring bias for fuel injection.
  • At least one component is configured to form a fuel flow passage between the fuel pressurization chamber and the spring cage chamber for sufficiently pressurizing the spring cage to assist the spring in closing the needle valve. Accordingly, the fuel pressure at which the needle valve closes is increased for improved fuel atomization.
  • the fuel flow passage is formed within a director cage.
  • the fuel flow passage comprises a small aperture formed in the director cage with a diameter of between 0.2 and 0.4 mm to allow fuel pressurization of the spring cage chamber.
  • the diameter is selected in accordance with the desired spring cage chamber pressure.
  • a diametral clearance is provided between the needle valve and its chamber, and a relief passage is provided such that the fuel may flow from the spray tip around the periphery of the needle valve, through the relief passage, and into the spring cage chamber for pressurizing the spring cage chamber.
  • a flat may be provided on the needle valve to allow such fuel flow therealong.
  • a restrictor body is provided with a restrictor chamber formed therein in selective fluid communication between the fuel pressur- ization chamber and the spring cage chamber.
  • the restrictor chamber includes a spring-loaded valve therein for selective fuel flow restriction between the fuel pressurization chamber and the spring cage chamber.
  • an object of the present inven- tion is to provide a fuel pumping device in which the needle valve is provided with an additional hydraulic force so that the needle valve closes at higher pressures for improved fuel atomization.
  • Another object of the present invention is to provide a fuel pumping device with a fuel flow passage provided between a spring cage chamber and a fuel pressurization chamber for allowing pressurization of the spring cage chamber to assist the spring in closing the needle valve, thereby closing the needle valve at higher fuel pressures.
  • FIGURE 1 shows a vertical cross-sectional view of a fuel pumping device in accordance with the present invention
  • FIGURE 2 shows an enlarged partial cross- sectional view of the fuel pumping device shown in Figure 1 ;
  • FIGURE 3 shows a vertical cross-sectional view of a fuel pumping device in accordance with an alterna- tive embodiment of the present invention
  • FIGURE 4 shows a cut-away vertical cross- sectional view of a stop plate for use with the embodiment shown in Figure 3 ;
  • FIGURE 5 shows a horizontal cross-section of a needle valve in accordance with a second alternative embodiment of the present invention.
  • FIGURE 6 shows a vertical cross-sectional view of a fuel pumping device in accordance with a third alternative embodiment of the present invention.
  • a fuel pumping device 10 is shown in accordance with the present invention for injecting fuel into the cylinder of a diesel engine or the like.
  • the fuel pumping device 10 includes a body 12 with a fuel pressurization chamber 14 formed therein.
  • a plunger 16 is engine-driven by means of a cam which engages the top portion 18 of the plunger 16 for driving the plunger up and down, as oriented in Figure 1, against the force of the spring 20.
  • An injector nut 22 is screwed onto the body 12 by means of the threads 24, and include a director cage
  • the needle valve 30 extends into the spray tip 29, which includes a spray tip chamber 31.
  • the body and director cage form a plurality of fuel flow channels therein for facilitating fuel flow within the pumping device 10 for injection.
  • An electronically controlled solenoid valve subassembly 32 is connected to the body for selectively facilitating pressurization of the fuel for injection as the plunger 16 is cycled up and down within the fuel pumping device 10.
  • the electronically controlled solenoid valve subassembly 32 includes a valve portion 34 which is spring-biased to a normally open position by spring 36, and is selectively moved to a closed position by energizing the solenoid coil 38 for moving the valve
  • the needle valve 30 extends from a spring cage chamber 62 into the spray tip chamber 31.
  • the needle valve will be forced upward, as oriented in Figure 1, against the force of the spring 60 in the spring cage chamber 62 for opening the needle valve 58 to permit injection from the spray tip chamber.
  • the present invention is more clearly understood with reference to Figure 2, which is an enlarged view of Figure 1.
  • the needle valve 30 will close when the force of the spring 60 is sufficient to overcome the force resulting from pressure of the fuel pushing upward against the needle valve in the spray tip chamber.
  • the director cage 64 is provided with an aperture 66 for facilitating fluid communication between the fuel pressurization chamber 14 and the spring cage chamber 62. The pressure in the enclosed spring cage is controlled by the aperture diameter. As fuel flows through the aperture 66 from the fuel pressurization chamber 14 into the spring cage chamber 62, fuel pressure is built up within the spring cage chamber 62.
  • the aperture 66 has a diameter between 0.2 and 0.4 mm.
  • fluid communication between the fuel pressurization chamber 14 and spring cage chamber 62 is provided by means of a needle valve clearance area 68 which allows fuel to flow from the spray tip chamber 31 along the outer periphery of the needle valve 30 and into the spring cage chamber 62. Accordingly, pressurized fuel flows from the fuel pressurization chamber 14 through channel 54 into the spray tip chamber 31, and along the outer periphery of the needle valve 30 in the clearance area 68, and through the relief passage 70 formed in the stop plate 28, and finally into the spring cage chamber 62 for assisting closure of the needle valve 30.
  • a pressure relief passage 63 is also provided for set up.
  • Figure 4 illustrates a cut-away cross-sectional view of the stop plate 28 for displaying the relief passage 70, and its communication with the spring cage chamber 62, in accordance with the embodiment shown in Figure 3.
  • the clearance area 68 between the needle valve 30 and its corresponding bore may be accomplished by providing a diametral difference between the needle valve chamber and the needle valve 30.
  • the respective diametral difference is preferably between 2 and 20 microns to allow fuel flow therethrough.
  • the needle valve 30 could simply be provided with a flat portion 74 to create a fuel flow passage along the side of the needle valve 30 to allow fuel to pass for pressurizing the spring cage chamber 62.
  • a restrictor body 78 is provided between the fuel pressurization chamber 14 and the director cage 26.
  • the restrictor body 78 includes a restrictor chamber 80 in selective fluid communication with the fuel pressurization chamber 14 through the aperture 82.
  • the restrictor chamber 80 includes a valve 84 which is loaded by the spring 86 upwardly against the valve seat
  • the director cage 26 is also provided with an aperture 90 and a piston 92, such that fuel within the restrictor chamber 80 may pass through the aperture 90 and push against the top surface 94 of the piston 92 for assisting closure of the needle valve 30. In this manner, fuel communication is provided between the fuel pressurization chamber 14 and the spring cage 62 for assisting closure of the needle valve 30 at higher fuel pressures.

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

L'invention porte sur une pompe à injection (10) comportant un injecteur à aiguille (30) commandé par pression, attenant à un logement (62) renfermant un ressort (60) rappelant l'aiguille (30) dans le sens de la fermeture. La pompe (10) est conçue pour que l'injecteur se referme à un niveau élevé de pression améliorant l'injection. La pompe (10) comporte un corps (12) abritant une chambre (14) de mise sous pression du carburant où s'établit la pression d'ouverture de l'injecteur. L'un au moins des composants consiste en un élément de guidage (64) comportant un petit orifice (66) de passage de carburant reliant la chambre (14) de mise sous pression au logement (62) du ressort, et aidant le ressort (60) à refermer l'injecteur (30) en accroissant la pression de refermeture de l'injecteur (30).
PCT/US1999/003257 1998-02-27 1999-02-16 Pompe d'injection a pression de refermeture de l'injecteur a aiguille renforcee WO1999043442A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US3263998A 1998-02-27 1998-02-27
US09/032,639 1998-02-27

Publications (1)

Publication Number Publication Date
WO1999043442A1 true WO1999043442A1 (fr) 1999-09-02

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1999/003257 WO1999043442A1 (fr) 1998-02-27 1999-02-16 Pompe d'injection a pression de refermeture de l'injecteur a aiguille renforcee

Country Status (1)

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WO (1) WO1999043442A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1794442A2 (fr) * 2004-09-28 2007-06-13 Electro-Motive Diesel, Inc. Injecteur de carburant a ressort de valve resistant a perte de vop a applications sur moteur a emissions conformes

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4378774A (en) * 1980-04-14 1983-04-05 Nippondenso Co., Ltd. Fuel injection system for internal combustion engines
US4684067A (en) * 1986-03-21 1987-08-04 General Motors Corporation Two-stage, hydraulic-assisted fuel injection nozzle
US4741478A (en) * 1986-11-28 1988-05-03 General Motors Corporation Diesel unit fuel injector with spill assist injection needle valve closure
US4934599A (en) * 1987-10-07 1990-06-19 Honda Giken Kogyo Kabushiki Kaisha Fuel injection nozzle for two-stage fuel injection
US5014671A (en) * 1988-12-29 1991-05-14 Yamaha Hatsudoki Kabushiki Kaisha High pressure fuel injection unit for engines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4378774A (en) * 1980-04-14 1983-04-05 Nippondenso Co., Ltd. Fuel injection system for internal combustion engines
US4684067A (en) * 1986-03-21 1987-08-04 General Motors Corporation Two-stage, hydraulic-assisted fuel injection nozzle
US4741478A (en) * 1986-11-28 1988-05-03 General Motors Corporation Diesel unit fuel injector with spill assist injection needle valve closure
US4934599A (en) * 1987-10-07 1990-06-19 Honda Giken Kogyo Kabushiki Kaisha Fuel injection nozzle for two-stage fuel injection
US5014671A (en) * 1988-12-29 1991-05-14 Yamaha Hatsudoki Kabushiki Kaisha High pressure fuel injection unit for engines

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1794442A2 (fr) * 2004-09-28 2007-06-13 Electro-Motive Diesel, Inc. Injecteur de carburant a ressort de valve resistant a perte de vop a applications sur moteur a emissions conformes
EP1794442A4 (fr) * 2004-09-28 2010-06-16 Electro Motive Diesel Inc Injecteur de carburant a ressort de valve resistant a perte de vop a applications sur moteur a emissions conformes

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