EP0017872A1 - Fuel nozzle check damper - Google Patents

Fuel nozzle check damper Download PDF

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Publication number
EP0017872A1
EP0017872A1 EP80101812A EP80101812A EP0017872A1 EP 0017872 A1 EP0017872 A1 EP 0017872A1 EP 80101812 A EP80101812 A EP 80101812A EP 80101812 A EP80101812 A EP 80101812A EP 0017872 A1 EP0017872 A1 EP 0017872A1
Authority
EP
European Patent Office
Prior art keywords
valve
injector
seat
fuel
seated against
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Withdrawn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
EP80101812A
Other languages
German (de)
English (en)
French (fr)
Inventor
Clayton Carl Johnson
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.)
Caterpillar Inc
Original Assignee
Caterpillar Tractor Co
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 Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Publication of EP0017872A1 publication Critical patent/EP0017872A1/en
Withdrawn legal-status Critical Current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
    • 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
    • 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
    • F02M2200/30—Fuel-injection apparatus having mechanical parts, the movement of which is damped
    • F02M2200/304—Fuel-injection apparatus having mechanical parts, the movement of which is damped using hydraulic means

Definitions

  • This invention relates to a fuel injector for internal combustion engines, and more specifically, to such an injector wherein there is included a spring loaded injector valve.
  • One type of fuel injector includes as principal elements a nozzle, an injector valve and a spring to urge the injector valve to a position closing the nozzle.
  • Another type of injector utilizes fuel trapped above the injector valve and compressed as the valve opens to provide the force required to urge the nozzle to the closed position.
  • a seat for the valve is located within the nozzle or tip of the injector such that only a very small volume of fuel exists downstream of the seat and upstream of the nozzle outlets.
  • the injector valve When high pressure fuel is provided to the fuel injector from an engine fuel pump, the injector valve is forced to open and fuel is injected through the nozzle into the combustion space. When fuel pressure from the fuel pump drops, the injector valve is returned to its closed position by the injector valve spring or fuel trapped above the valve and injection of fuel to the combustion space is cut off.
  • valve closing force is typically high so as to effect rapid closing of the valve thereby providing the ability to closely control the length of the injection period by controlling the pressure of fuel supplied by the fuel pump.
  • the high closing force thus causes the valve to engage the seat with a considerable impact.
  • the impact can be of a magnitude that will create stresses and cause breakage of the nozzle tip through the mechanism of fatigue failure. Failure of the nozzle tip causes metal particles to drop into the combustion space which interfere with the smooth operation of the engine. Also, since the injector valve seat is no longer present, the injector valve cannot stop fuel injection at the proper time. Fuel therefore flows into the combustion space at all times, causing localized engine heating, fuel waste and increased hydrocarbon exhaust emissions.
  • valve impact is not of a magnitude sufficient to cause nozzle tip breakage, or prior to failure of the nozzle tip, this impact may have detrimental effects on engine performance.
  • the impact can cause rebound of the injector valve from the valve seat, reopening the injector valve. Rebound will allow additional fuel to flow into the combustion space, resulting, to a lesser degree, in the above problems associated with nozzle tip breakage, and may allow combustion gas to enter the fuel injector.
  • a fuel injector including a nozzle tip, an injector valve and means to urge the injector valve towards a closed position, means to slow the injector valve as it approaches the closed position, thereby reducing impact forces associated with valve closure.
  • FIG. 1 An exemplary embodiment of a fuel injector made according to the invention is illustrated in Fig. 1 and is used in connection with an internal combustion engine (not shown).
  • the injector includes an elongated body 8 which receives fuel supplied to an inlet port 10 at one end of the body 8 and ultimately directs the fuel to a combustion space (not shown) through a nozzle in the form of fuel injector tip orifices 12 located at the opposite end of the body 8.
  • the fuel inlet port 10 is in fluid communication with the orifices 12 through a fuel passageway 14 located in a fuel line adapter 16, a fuel passage 18 extending through the main body of the fuel injector and a fuel chamber 20 which surrounds the lower portion of a fuel injector valve 22.
  • high pressure fuel is supplied to the intake port 10 in a conventional fashion and is communicated to the fuel chamber 20.
  • the high pressure fuel in the fuel chamber 20 acts upon a piston surface 24' of the injector valve 22 which is slidably received in a bore 25 in the upper portion of the fuel injector tip 26.
  • a slight clearance 27 (Fig. 2) is provided between a piston portion 24 of the injector valve 22 and the injector tip 26 so that a small amount of fuel may flow past the injector valve 22 and provide lubrication between the valve and the injector tip 26.
  • This lubricating fuel flows into a spring chamber 28 having a lower end 29 and is ultimately returned to the fuel system through return ports 30.
  • fuel in the chamber 28 will be at low pressure.
  • valve tip 38 thereon separates from a valve seat 40 located in the injector tip 26, placing the fuel chamber 20 in fluid communication with the injection tip orifices 12. Fuel from the fuel chamber 20 is thus expelled through the orifices 12 into the engine combustion chamber.
  • the injector valve 22 When the valve tip 38 once again contacts the valve seat 40, the injector valve 22 is in its closed position blocking the flow of fuel from the fuel chamber 20 through the orifices 12 and into the engine combustion chamber.
  • the check damper 42 is a flat, thin circular spacer and has a close diametral fit with the inner surface of the spring chamber 28.
  • the diametral clearance 45 between the check damper 42 and the inner surface of the spring chamber 28 is typically, though not limited to, .001".
  • the spring 32 will overcome the force caused by the pressure of the fuel and the injector valve 22 will begin to move in a downwardly direction towards the closed position. Since the lower end 29 of the spring chamber 28 is filled with fuel, the injector valve 22 can close only as rapidly as fuel can escape past the check damper 42. By controlling the diametral clearance 45 between the check damper 42 and the inner surface of the spring chamber 28, the rate of fuel flow around the check damper 42, and therefore the velocity of the injector valve 22, may be controlled.
  • diametral clearance of .001 provides the desired fuel flow rate around the check damper 42 and consequently, the desired injector valve 22 closing velocity. It must be noted, however, that suitable diametral clearance can only be determined in conjunction with other fuel injector parameters, in particular, the return spring's 28 spring rate, friction present between the piston portion 24 of the injector valve 22 and the bore 25 of the injector tip 26, fuel viscosity, and the mass of injector valve 22.
  • valve position versus time curve 48 shows that, in the typical fuel injector, after the injector valve 22 first closes at the indicated valve closing point 50, the valve will "bounce" or, in other words, reopen . and reclose a number of times before finally firmly seating on the injector valve seat 40.
  • the stress curve 52 indicates that repeated openings and closing of the valve tip 38 cause a number of reversing stress cycles to be imposed upon the injector tip 26. Cyclical stresses of the type illustrated by stress curve 52 are known to cause component failure through the mechanism of fatigue failure. It has been observed that cyclical loading eventually causes the portion of injector tip 26 around valve seat 40 to break off which allows direct, uncontrolled fluid communication between fuel chamber 20 and the engine combustion space. The result is that a very large amount of fuel flows into the combustion space whenever fuel is provided to the broken injector, greatly increasing fuel consumption, localized engine temperature and hydrocarbon emissions.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP80101812A 1979-04-13 1980-04-03 Fuel nozzle check damper Withdrawn EP0017872A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PCT/US1979/000231 WO1980002311A1 (en) 1979-04-13 1979-04-13 Fuel nozzle check damper
WOPCT/US79/00231 1979-04-13

Publications (1)

Publication Number Publication Date
EP0017872A1 true EP0017872A1 (en) 1980-10-29

Family

ID=22147560

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80101812A Withdrawn EP0017872A1 (en) 1979-04-13 1980-04-03 Fuel nozzle check damper

Country Status (4)

Country Link
EP (1) EP0017872A1 (enrdf_load_stackoverflow)
JP (1) JPS56500388A (enrdf_load_stackoverflow)
BR (1) BR7909000A (enrdf_load_stackoverflow)
WO (1) WO1980002311A1 (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4911366A (en) * 1988-05-16 1990-03-27 Steyr-Daimler-Puch Ag Fuel injection valve for air-compressing internal combustion engines with fuel injection
FR2742190A1 (fr) * 1995-12-09 1997-06-13 Bosch Gmbh Robert Injecteur de carburant pour moteurs a combustion interne
GB2312924A (en) * 1996-05-07 1997-11-12 Caterpillar Inc Direct-operated, velocity-controlled nozzle valve for a fuel injector
DE19636896C1 (de) * 1996-09-11 1998-05-07 Daimler Benz Ag Kraftstoffeinspritzdüse für Brennkraftmaschinen
WO1999028616A1 (de) * 1997-11-27 1999-06-10 Robert Bosch Gmbh Kraftstoffeinspritzventil für brennkraftmaschinen
US11698043B1 (en) 2022-03-09 2023-07-11 Caterpillar Inc. Fuel injector for fuel system having damping adjustment valve

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3221442A1 (de) * 1982-06-07 1983-12-08 Robert Bosch Gmbh, 7000 Stuttgart Kraftstoff-einssritzduese fuer brennkraftmaschinen
US5826802A (en) * 1995-11-17 1998-10-27 Caterpillar Inc. Damped check valve for fluid injector system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1110102A (en) * 1963-11-26 1968-04-18 Ruston & Hornsby Ltd Improvements in fuel injection equipment for internal combustion engines
US3398936A (en) * 1966-08-02 1968-08-27 Curtiss Wright Corp Fuel injection pintle
DE2120108A1 (de) * 1971-04-24 1972-11-09 LOrange KG, 7000 Stuttgart Kraftstoffeinspritzdüse
SU380858A2 (enrdf_load_stackoverflow) * 1971-10-04 1973-05-15
GB1406216A (en) * 1971-10-30 1975-09-17 Cav Ltd Fuel injection nozzle units

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2667896A (en) * 1950-10-20 1954-02-02 Borg Warner Unloading valve
JPS5332447B2 (enrdf_load_stackoverflow) * 1974-02-14 1978-09-08

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1110102A (en) * 1963-11-26 1968-04-18 Ruston & Hornsby Ltd Improvements in fuel injection equipment for internal combustion engines
US3398936A (en) * 1966-08-02 1968-08-27 Curtiss Wright Corp Fuel injection pintle
DE2120108A1 (de) * 1971-04-24 1972-11-09 LOrange KG, 7000 Stuttgart Kraftstoffeinspritzdüse
SU380858A2 (enrdf_load_stackoverflow) * 1971-10-04 1973-05-15
GB1406216A (en) * 1971-10-30 1975-09-17 Cav Ltd Fuel injection nozzle units

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4911366A (en) * 1988-05-16 1990-03-27 Steyr-Daimler-Puch Ag Fuel injection valve for air-compressing internal combustion engines with fuel injection
FR2742190A1 (fr) * 1995-12-09 1997-06-13 Bosch Gmbh Robert Injecteur de carburant pour moteurs a combustion interne
GB2312924A (en) * 1996-05-07 1997-11-12 Caterpillar Inc Direct-operated, velocity-controlled nozzle valve for a fuel injector
US5752659A (en) * 1996-05-07 1998-05-19 Caterpillar Inc. Direct operated velocity controlled nozzle valve for a fluid injector
GB2312924B (en) * 1996-05-07 1999-12-29 Caterpillar Inc Direct operated velocity controlled nozzle valve for a fluid injector
DE19636896C1 (de) * 1996-09-11 1998-05-07 Daimler Benz Ag Kraftstoffeinspritzdüse für Brennkraftmaschinen
WO1999028616A1 (de) * 1997-11-27 1999-06-10 Robert Bosch Gmbh Kraftstoffeinspritzventil für brennkraftmaschinen
US11698043B1 (en) 2022-03-09 2023-07-11 Caterpillar Inc. Fuel injector for fuel system having damping adjustment valve

Also Published As

Publication number Publication date
BR7909000A (pt) 1981-03-31
JPS56500388A (enrdf_load_stackoverflow) 1981-03-26
WO1980002311A1 (en) 1980-10-30

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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

Designated state(s): BE DE GB

17P Request for examination filed
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: 19820427

RIN1 Information on inventor provided before grant (corrected)

Inventor name: JOHNSON, CLAYTON CARL