EP0030103A1 - Valve d'injection de combustible et système muni d'une telle valve - Google Patents

Valve d'injection de combustible et système muni d'une telle valve Download PDF

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Publication number
EP0030103A1
EP0030103A1 EP80304156A EP80304156A EP0030103A1 EP 0030103 A1 EP0030103 A1 EP 0030103A1 EP 80304156 A EP80304156 A EP 80304156A EP 80304156 A EP80304156 A EP 80304156A EP 0030103 A1 EP0030103 A1 EP 0030103A1
Authority
EP
European Patent Office
Prior art keywords
valve
fuel
guide
angle
seat
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Withdrawn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
EP80304156A
Other languages
German (de)
English (en)
Inventor
William A. Grgurich
Albert B. Niles
Kenneth W. Updyke
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 EP0030103A1 publication Critical patent/EP0030103A1/fr
Withdrawn legal-status Critical Current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
    • F02M61/18—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
    • 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
    • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
    • F02M61/12—Other injectors with elongated valve bodies, i.e. of needle-valve type characterised by the provision of guiding or centring means for valve bodies

Definitions

  • This invention relates generally to fuel injection nozzle valves,.
  • fuel injection nozzle valves operate in response to high pressure fuel creating forces acting on differential areas of the valve causing rapid reciprocation of the valve.
  • the rapid reciprocation causes intermittent seating and unseating of a tip of the valve with a valve seat which permits the fuel to be injected into an engine cylinder. Under the influence of such high pressure, this seating and unseating results in tip wear which is known to change the differential areas to the point where valve operating characteristics are changed undesirably.
  • the rapid reciprocation of the valve in a valve alignment guide causes detrimental wear between the valve and guide to add to the undesirable change in operating characteristics.
  • VOP valve opening pressure
  • VCP valve closing pressure
  • VOP results from high pressure fluid forces intermittently imposed on the valve and is required to cause the valve to lift or unseat and permit fuel injection. Over a period of time, wear at the tip and seat can cause a significant detrimental loss of VOP (VOP loss).
  • VCP results from forces acting on the valve and is required to cause the valve to seat and stop fuel injection.
  • Conventional fuel injection nozzle valves become seated between the timing of the intermittently imposed high pressure fluid forces which lift the valve from the seat. Such seating is usually accomplished by a high rate spring matched with specific initial VOP parameters.
  • Conventional fuel injection nozzle valves also have a relatively close fit between the valve and guide to limit leakage of fuel past the guide. Some fuel does leak past the guide and is usually returned to a fuel reservoir. The tight fit creates high friction forces which limit rapid valve closing resulting in poor injection. As the valve and guide wear, friction is reduced and VOP loss occurs due to the reduced friction. The spring then becomes unmatched with the specific intial VOP parameters. In addition, the desired relationship of VOP to VCP gradually deteriorates. Such deterioration results in inefficient fuel injection causing fuel waste, unduly high noxious exhaust emissions, and excessive exhaust smoke.
  • a fuel injection nozzle valve comprising a housing having a conical valve seat of a first constant conical angle,(the seat including a lower portion, and a valve member reciprocable in the housing,is characterized in that the valve member has a conical tip of a second constant conical angle less than the first angle, the tip having a lower portion formed so as to contact only the lower portion of the valve seat.
  • the valve member has a conical tip of a second constant conical angle less than the first angle, the tip having a lower portion formed so as to contact only the lower portion of the valve seat.
  • a fuel injection nozzle valve comprising a housing having a valve guide of a first diameter separating a closed upper fluid cavity from a lower fluid cavity, and a conical valve seat; and a member valve reciprocable in the housing and having a conical tip engaging the seat is characterized in that the valve member has an enlarged diameter portion reciprocable in the guide, the enlarged diameter portion being of a second diameter less than first guide diameter, the guide and enlarged portion diameters defining a clearance therebetween sufficient for metering an amount of fluid between, the upper and lower cavities for maintaining relative fluid pressures in the cavities to avoid a hydraulic lock of the valve in the housing.
  • the invention also includes a fuel system incorporating such valves.
  • a fuel system is generally design- a ted 10, and includes a reservoir 12.
  • a well known fuel transfer pump 13 is connected via a conduit 14 for pumping fuel from reservoir 12 at a system pressure of about 30 - 35 psi.
  • the fuel is then passed through a known filter 16 in conduit 18 to a conventional high pressure fuel injection pump 20 which supplies the fuel at pressures ranging from about 2000 psi to about 15,000 psi and then to a fuel injection nozzle valve 22 via a conduit 24.
  • a known reverse flow check valve 26 be provided between high pressure pump 20 and nozzle valve 22 to check against pressure waves which may oscillate between pump 20 and nozzle valve 22 as a result of rapidly created high pressure surges of fuel being pumped through nozzle valve 22 into an associated engine cylinder 23 at a rate of several times per second.
  • Nozzle valve 22 comprises a housing 28 having a fuel passage 30 for receiving fuel from pump 20 and for conducting the fuel to a cavity 32 formed in housing 28.
  • Housing 28 defines an upper cavity portion 32a and a lower cavity portion 32b and further defines a reduced diameter cylindrical guide 34 separating the upper and lower cavity portions 32a, 32b, respectively.
  • Guide 34 has a diameter designated dg in Figure 4.
  • a valve member 36 is reciprocably disposed in cavity 32.
  • An extended portion 36a of valve 36 extends into upper cavity portion 32a.
  • Valve 36 includes a lower portion 36b having a tip 38 urged into engagement with a valve seat 40 formed in housing 28. Tip 38 is so urged by a resilient means such as a compression spring 42 disposed in upper cavity portion 3 2a.
  • Upper and lower valve portions 36a, 36b, respectively, are separated by an enlarged diameter valve portion 36c which reciprocates within guide 34 and has a valve diameter designated dv in Figure 4.
  • valve portion 36c and guide 34 have a relatively tight fit to limit leakage of fuel from lower cavity 32b to upper cavity 32a.
  • Such tight fit causes the problem of high frictional forces between the valve and guide which limit movement of valve portion 36c in guide 34.
  • Such friction causes substantial wear which substantially changes the initial valve and guide diameters so that after prolonged hours of operation, the initial operating characteristics of the nozzle become.undesirably changed.
  • fuel which does leak into upper cavity 32a is returned to the fuel reservoir.
  • This embodiment of the invention generally includes housing 28 provided with a guide 34 of a first diameter dg separating upper cavity 32a from lower cavity 32b.
  • Valve 36 is provided with an enlarged diameter portion 36a reciprocable in guide 34 and having a second diameter dv, less than the guide diameter dg.
  • the diameters dv, dg define a clearance sufficient for passing fluid from the lower cavity 32b to the upper cavity 32a for metering relative fluid pressures in said cavities 32, 32b to avoid a hydraulic lock of valve 36 in housing 28. Fluid passing through the clearance forms a lubricating fluid film which assists in hydraulically aligning valve portion 36c in guide 34.
  • the clearance varies depending on para-, meters of nozzle 22 relating to the diameter dg and length of guide 34, and the quantity and pressure of fluid volume trapped in upper cavity 32a.
  • Such expanded clearance permits passage or leakage of fuel from lower cavity 32b to upper cavity 32a. Due to the expanded diametral clearance, friction and thus wear are substantially reduced between guide 34 and valve portion 36c. Such leakage provides an advantageous lubricating hydraulic film of fluid in the expanded clearance between guide 34 and valve portion 36c. Fuel which leaks into cavity 32a is not returned to reservoir 12 since cavity 32a represents a trapped volume having no outlet except for a bleed screw 44 which is normally closed but may be selectively opened if desired. There is less wear between guide 34 and valve portion 36c as compared to previously known nozzles. Thus, the increased guide clearance of the present invention substantially reduces a change in VCP during the useful life of nozzle 22.
  • increased guide clearance provides an advantageous hydraulic film between guide 34 and valve portion 36c which permits valve 36 to self align resulting in a centered seating of tip 38 on seat 40 and reduced impact loads during seating of tip 38 on seat 40.
  • the diameter dg of guide 34 is about 3.9878 mm
  • length of guide 34 is about 7.644 mm
  • the trapped volume quantity is about x 121.4mm 3
  • the peak trapped volume pressure is about 6 x 10 6 N/m 2 (90 0 psi).
  • the graph of Figure 5 illustrates the basis for the preferred guide clearance range.
  • the trapped volume of fuel which leaks into upper cavity portion 32a ultimately reaches a peak pressure Pt, that is, the highest pressure the trapped volume of fuel sees during an injection stroke of valve 36.
  • This peak pressure in addition to spring 42, acts on upper portion 36a of valve 36 on closing or seating of tip 38 against seat 40.
  • fuel pressure B is the average pressure between injections, of the fuel remaining in upper cavity 32a after seating of tip 38 against seat 40. From the Figure 5 graph, it is apparent that the peak pressure curve A has a substantially stable portion extending from a guide clearance of about 0.1143 mm (.000450 inches) to about .01651 mm (.000650 inches).
  • the portion of the peak pressure curve wherein the guide clearance is greater than .01651 mm (.000650 inches) illustrates that peak pressure rises at a rate sufficient to eventually cause a hydraulic lock of valve 36 in housing 28. That is, if guide clearance is too great the value of the pressures in cavities 32a, 32b will converge and valve 36 will not reciprocate.
  • the preferred guide clearance range of about .01143 mm (.000450 inches) to about .01651 mm (.000650 inches) permits the VCP to substantially stabilize resulting from a combination of forces acting on uppervalve portion 36a including forces exerted by spring 42 and forces exerted by trapped volume peak pressure in upper cavity 32a. These forces act across an area defined by the diameter dv of valve 36 at portion 36c. Also, in the preferred guide clearance range, residual pressure is substantially reduced which lowers VOP required to lift valve 36 for the next injection.
  • the present embodiment also uses wear advantageously to avoid detrimental VOP loss during the useful life - of nozzle 22.
  • This is accomplished by providing seat 40 with preferably a constant conical angle sa and also providing tip 38 with a constant conical angle ta which is less than the angle sa, see Figure 2. It is preferred that angle ta be less than angle sa by a magnitude of from about 2.5 degrees to about 3.5 degrees. In this manner only a lower portion 38a of a tip 38 contacts only a lower portion 40a of seat 40. As a result, tip portion 38a and seat portion 40a have an interference fit and contact is made at an intial (solid line) diameter sd 1 , see Figure 3.
  • the area defined by diameter dv of valve 36 at portion 3 6c and the areas defined by the diameters sd l , sd 2 of valve 36 at tip portion 38a, are the differential areas affected by fuel pressure for causing valve 36 to reciprocate in housing 28 and provide fuel injection. It can be seen, therefore, that with an increase from diameter sd 1 to diameter sd 2 , and with diameter dv and the force of spring 42 remaining substantially constant, the difference between the defined areas will be reduced and VOP loss can be reduced.
  • An advantage of providing contact between lower tip portion 38a and lower seat portion 40a is a resultant reduction in volume of a sac portion 46. It is well known that a small sac volume 46 is preferred and results in decreasing the emission of hydrocarbons into the atmosphere. Also, a desirable effect of small sac volume and a plurality of small orifices 48 is that some hydraulic damping occurs which aids in cushioning the tip to seat contact.
  • Prolonged use of nozzle 22 causes an area of tip 38 to seat 40 contact to increase as defined by a initial diameter sd 1 to an eventual diameter of sd 2 , greater than sd l '.
  • Diameter dv of valve portion 36c remains substantially constant due to reduced wear between guide 34 and valve portion 36c. As a result, the difference between the areas defined by diameters dv and sd 2 is reduced and substantial VOP loss is avoided.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP80304156A 1979-11-30 1980-11-20 Valve d'injection de combustible et système muni d'une telle valve Withdrawn EP0030103A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PCT/US1979/001091 WO1981001592A1 (fr) 1979-11-30 1979-11-30 Injecteur de carburant
WOPCT/US79/01091 1979-11-30

Publications (1)

Publication Number Publication Date
EP0030103A1 true EP0030103A1 (fr) 1981-06-10

Family

ID=22147824

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80304156A Withdrawn EP0030103A1 (fr) 1979-11-30 1980-11-20 Valve d'injection de combustible et système muni d'une telle valve

Country Status (5)

Country Link
EP (1) EP0030103A1 (fr)
JP (1) JPS56501655A (fr)
BR (1) BR7909045A (fr)
CA (1) CA1145218A (fr)
WO (1) WO1981001592A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2510197A1 (fr) * 1981-07-22 1983-01-28 Lucas Ind Plc Injecteur de combustible
GB2118624A (en) * 1982-04-13 1983-11-02 British Internal Combust Eng >I.C. engine liquid fuel injector

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1987007334A2 (fr) * 1986-05-31 1987-12-03 Robert Bosch Gmbh Soupape d'injection de carburant

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE928499C (de) * 1944-07-11 1955-06-02 Hermann Papst Einspritzventilduese
DE932209C (de) * 1952-04-13 1955-08-25 Bosch Gmbh Robert Kraftstoffeinspritzventil
US2747555A (en) * 1951-04-03 1956-05-29 Sulzer Ag Fuel supply system for internal combustion engines
CH402510A (de) * 1963-05-14 1965-11-15 Sulzer Ag Brennstoffeinspritzventil einer Kolbenbrennkraftmaschine
DE1576582A1 (de) * 1967-07-15 1970-02-12 Kloeckner Humboldt Deutz Ag Kraftstoffeinspritzventil
US3777984A (en) * 1972-01-20 1973-12-11 Mack Trucks Miniature fuel injection nozzle and holder assembly
US3836080A (en) * 1973-09-10 1974-09-17 Ambac Ind Fuel injection nozzle
DE2347100A1 (de) * 1973-09-19 1975-03-27 Kloeckner Humboldt Deutz Ag Brennstoffeinspritzvorrichtung
US4106702A (en) * 1977-04-19 1978-08-15 Caterpillar Tractor Co. Fuel injection nozzle tip with low volume tapered sac
DE2710217A1 (de) * 1977-03-09 1978-09-14 Bosch Gmbh Robert Kraftstoffeinspritzduese
DE2843000A1 (de) * 1978-10-03 1980-04-24 Bosch Gmbh Robert Kraftstoffeinspritzduese

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2927737A (en) * 1952-04-12 1960-03-08 Bosch Gmbh Robert Fuel injection valves

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE928499C (de) * 1944-07-11 1955-06-02 Hermann Papst Einspritzventilduese
US2747555A (en) * 1951-04-03 1956-05-29 Sulzer Ag Fuel supply system for internal combustion engines
DE932209C (de) * 1952-04-13 1955-08-25 Bosch Gmbh Robert Kraftstoffeinspritzventil
CH402510A (de) * 1963-05-14 1965-11-15 Sulzer Ag Brennstoffeinspritzventil einer Kolbenbrennkraftmaschine
DE1576582A1 (de) * 1967-07-15 1970-02-12 Kloeckner Humboldt Deutz Ag Kraftstoffeinspritzventil
US3777984A (en) * 1972-01-20 1973-12-11 Mack Trucks Miniature fuel injection nozzle and holder assembly
US3836080A (en) * 1973-09-10 1974-09-17 Ambac Ind Fuel injection nozzle
DE2347100A1 (de) * 1973-09-19 1975-03-27 Kloeckner Humboldt Deutz Ag Brennstoffeinspritzvorrichtung
DE2710217A1 (de) * 1977-03-09 1978-09-14 Bosch Gmbh Robert Kraftstoffeinspritzduese
US4106702A (en) * 1977-04-19 1978-08-15 Caterpillar Tractor Co. Fuel injection nozzle tip with low volume tapered sac
DE2843000A1 (de) * 1978-10-03 1980-04-24 Bosch Gmbh Robert Kraftstoffeinspritzduese

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2510197A1 (fr) * 1981-07-22 1983-01-28 Lucas Ind Plc Injecteur de combustible
GB2118624A (en) * 1982-04-13 1983-11-02 British Internal Combust Eng >I.C. engine liquid fuel injector

Also Published As

Publication number Publication date
BR7909045A (pt) 1981-10-20
CA1145218A (fr) 1983-04-26
WO1981001592A1 (fr) 1981-06-11
JPS56501655A (fr) 1981-11-12

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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

17P Request for examination filed

Effective date: 19801202

AK Designated contracting states

Designated state(s): BE CH DE FR GB IT SE

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: 19850304

RIN1 Information on inventor provided before grant (corrected)

Inventor name: UPDYKE, KENNETH W.

Inventor name: GRGURICH, WILLIAM A.

Inventor name: NILES, ALBERT B.