EP0097429A1 - Injecteur-pompe combiné à un combustible - Google Patents

Injecteur-pompe combiné à un combustible Download PDF

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Publication number
EP0097429A1
EP0097429A1 EP83302947A EP83302947A EP0097429A1 EP 0097429 A1 EP0097429 A1 EP 0097429A1 EP 83302947 A EP83302947 A EP 83302947A EP 83302947 A EP83302947 A EP 83302947A EP 0097429 A1 EP0097429 A1 EP 0097429A1
Authority
EP
European Patent Office
Prior art keywords
pump
injector assembly
fluid
pump cylinder
retaining means
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
EP83302947A
Other languages
German (de)
English (en)
Other versions
EP0097429B1 (fr
Inventor
James Louis Martin
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 Inc
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 Inc, Caterpillar Tractor Co filed Critical Caterpillar Inc
Publication of EP0097429A1 publication Critical patent/EP0097429A1/fr
Application granted granted Critical
Publication of EP0097429B1 publication Critical patent/EP0097429B1/fr
Expired 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
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • 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

Definitions

  • This invention relates generally to fluid pumping and injecting apparatus and more particularly to unit fuel pump-injectors for delivering fuel directly to the combustion chambers of a compression-ignition engine.
  • the amount of high pressure fuel leakage between the internal components is also very sensitive to the quality of surface finish and parallelism of the numerous abutting sealing end surfaces of those parts. Excessive fuel leakage erodes and thereby irreparably damages the sealing end surfaces and also helps to cause undesirably large tolerances on injector fuel flow rate and injector valve opening pressure.
  • the entire pump-injector must be disassembled for servicing or rebuilding even though it is usually only the spray tip of the injector assembly that requires replacement or cleaning since only the spray tip is directly exposed to the severe environment of the engine combustion chamber.
  • the combustion by-products build up carbon and corrosive elements in the seat area between the spray tip and nut, in addition to the spray tip orifices, making it difficult to disassemble and clean the spray tip and nut.
  • the injector assembly of the pump-injector must be disassembled even though it may be only the pump assembly that requires servicing.
  • a unit fluid pump-injector assembly comprising a housing; a pump assembly having a pump cylinder and a plunger therein for developing an injection charge of pressurized fluid; and an injector assembly for injecting the charge of fluid through an outlet, is characterized in that a first means is provided for removably retaining the pump cylinder against the housing; and that a second means is provided for removably retaining the injector assembly against the first means so that the injector assembly may be removed from or assembled to the first retaining means without altering the position or arrangement of the pump assembly relative to the first retaining means.
  • the present invention thus provides a : modular unit fluid pump-injector having two joints for separately scaled clamping the internal components thereby facilitating easier assembling and servicing of the pump-injector. With fewer internal parts clamped beween each joint, the pump-injector is less prone to high pressure fluid leakage and having the plunger bind in the pump cylinder. Also, either the pump or injector assembly can be serviced without disturbing the other one relative to the first retaining means.
  • FIG. 1 and 2 wherein similar reference numbers designate the same parts in the two views, the preferred embodiment of a unit fluid pump-injector 10 is shown after it has been assembled and then seated against an internal frusto-conical seat or surface 12 located within a stepped bore l4 of a cylinder head 16.
  • the upper portion of the pump-injector is conventional and comprises a housing 18 and a pump assembly 20.
  • a two-prong clamp 22 and a bolt 24 fasten the housing 18 to the cylinder head 16.
  • the lower portion of the pump-injector 10 is unconventional and comprises a first means 26 for removably retaining a portion of the pump assembly 20 against the housing 18, an injector assembly 28, and a second means 30 for removably retaining the injector assembly 28 against the first retaining means 26 so that the injector assembly 28 may be removed from or assembled to the first retaining means 26 without requiring removal of the first retaining means 26 or even altering the position or arrangement of the pump assembly 20 relative to the first retaining means 26.
  • the pump assembly 20 may be removed from or assembled to the first retaining means 26 without requiring removal of the second retaining means 30 or even altering the position or arrangement of the injector assembly 28 relative to the first retaining means 26.
  • the pump assembly 20 includes a pump cylinder or barrel 32 and a plunger 34.
  • the pump cylinder 32 has upper and lower fluid ports 36,38 which communicate with an internal pumping chamber 40.
  • the pump cylinder 32 also includes a reduced-diameter external end portion 42 which is piloted into the housing 18 and is sealably seated against the housing 18 at a housing shoulder 44.
  • the plunger 34 having an internal transverse channel 46 communicating with an internal longitudinal channel 48 and a helical fluid-metering groove 50, is slidably positioned within the pumping chamber 40 and is rotatably clasped by a bifurcated follower 52 which is reciprocable within the housing 18.
  • a plunger return spring 54 cooperates with a pivotal rocker 56, a push rod 58, and an engine-driven rotatable camshaft 60 in effecting reciprocation of follower 52 and plunger 34.
  • the first retaining means 26 includes a first elongate sleeve-type nut or retainer 68, and a pump cylinder retainer 70.
  • the first nut 68 has stepped large, intermediate, and small diameter bores 72, 74, 76, whereby the intermediate and small diameter bores 74, 76 define a shoulder 78.
  • the pump cylinder 32 is positioned in the large diameter bore 72 and the pump cylinder retainer 70 is positionerd within the intermediate diameter bore 74 and is sealably seated between the pump cylinder 32 and the shoulder 78.
  • An annular seal 84 is positioned between the first threaded portion 80 and housing 18.
  • annular fluid reservoir 86 Located concentrically between the first nut 68 and the pump cylinder 32 is an annular fluid reservoir 86 which communicates with upper and lower fluid ports 36, 38.
  • the first nut 68 also includes fluid supply and return ports 88, 90, which communicate with the fluid reservoir 86 and also with an annular space 92 in the cylinder head bore 14 which communicates with a fluid supply manifold (not shown).
  • a plurality of annular fluid seals 94 are externally positioned on the first nut 68 above and below the fluid supply ports 88, 90.
  • the pump cylinder retainer 70 includes a centrally-located fluid delivery opening 96, which connects the pumping chamber 40 'and the injector assembly 28, and a means 98 for returning fluid leakage from the small diameter bore 76 of the first nut 68 to the annular fluid reservoir 86.
  • the fluid leakage return means 98 is a passage angularly drilled in the pump cylinder retainer 70.
  • the injector assembly 28 is located partially in the small diameter bore 76 of the first nut 68 and includes a valve body 100, a valve 102 positioned within the valve body 100, a means 104 for resiliently biasing the valve 102, and a formed case 106 sealably encircling or encapsulating the valve body 100 and the resilient biasing means 104 and retaining them against separation.
  • the valve body 100 includes a spray tip 108 having a valve seat 110 and at least one outlet or spray orifice 112, a spacer block or spring cage 114 sealably abutting the spray ' tip 108, and a spring retainer 116 abutting the spacer block 114 and also sealably abutting the pump cylinder retainer 70.
  • Internal portions of the spray tip 108, spacer block 114, and spring retainer 116 define at least one fluid charge delivery passage 118 which communicates between the fluid delivery opening 96 of the pump cylinder retainer 70 and the outlet 112 of the spray tip 108.
  • the middle portion of the spray tip 108 defines a cardioidal or heart-shaped fluid pressure chamber 121 in the passage 118.
  • the spray tip 108 and spacer block 114 define a centrally-disposed longitudinal stepped bore 120 which houses the slidable valve 102 and resilient biasing means 104.
  • the resilient biasing means 104 includes a helical compression spring 122 and optionally one or more annular spring-preload shims 124.
  • the valve 102 includes a conical tip portion 126, a cylindrical needle portion 128, an annular convex surface portion 130 positioned in the cardioid chamber 121, a relatively larger diameter guide portion 132, a spring seat portion 134, and a stop portion 136.
  • the valve 102 is movable between a first position at which the tip portion 126 is seated on valve seat 110, thereby blocking fluid communication between the fluid. charge delivery passage 118 and the outlet 112, and a second position at which the tip portion 126 is upwardly spaced from the valve seat 110 thereby opening fluid communication.
  • the spring retainer 116 has a centrally disposed cavity 138, facing the fluid delivery opening 96 of the pump cylinder retainer 70, and houses a reverse-flow check valve 140.
  • the check valve 140 in response to differential fluid pressure and gravity is movable between a first position at which the check valve 140 is spaced from the opening 96 and a second position at which the check valve 140 seats against the pump cylinder retainer 70 and blocks the opening 96.
  • the case 106 ofcthe injector assembly 28 is preferably formed of a ductile metal having good heat conducting properties and is pressed or coined to the shape illustrated around the spray tip 108, spacer block 114, and spring retainer 116.
  • the case 106 is substantially tubular and has a frusto-conical end portion 142 which mates with a frusto-conical end portion 144 of the spray tip 108.
  • the case 106 and spacer block 114 define a fluid bleed-off passage 146 which communicates.with the valve body bore 120 and the fluid leakage return means 98 of the pump cylinder retainer 70.
  • the second retaining means 30 includes a second sleeve-type nut or retainer 148 having a substantially tubular portion 150 with a longitudinally splined exterior surface 152 and a frusto-conical end portion 154 which is positioned in close proximity to the interiorly disposed cardioidal chamber 121 of the spray tip 108 and which seats against the internal frusto-conical seat 12 of the cylinder head 16.
  • the first nut 68 has a second externally-threaded portion 156 which threadably mates with the tubular portion 150 of the second nut 148.
  • An annular fluid seal 158 is provided adjacent the second threaded portion 156 and second nut 148.
  • the injector assembly 28 is sealably and removably retained between the pump cylinder retainer 70 and the frusto-conical end portion 154 of the second nut 148.
  • the sandwiched frusto-conical end portions 144,142,154 of the spray tip 108, case 106, and second nut 148, respectively, have the same included angles S,C,N and are selected from the range of about 40° to 80°, and, more preferably are about 50°.
  • This frusto-conical configuration of the end portions 144,142,154 in assembled cooperation with the tightened clamp 22 ensures adequate sealing between the seat 12 and these mating end portions relative to the combustion chamber.
  • This configuration also induces a preselected compressive-stress state in the close proximity region of the spray tip 108 defining the cardioidal chamber 121, to prevent tensile-stress induced cracking and improve the fluid-pressure loading capability and fatigue life of that spray tip region, and yet prevent a loss of optimal guiding, sliding, and fluid leakage clearance between the bore 120 and the slidable valve guide portion 132 when the second nut 148 is tightened.
  • the angles S,C, and N are selected to prevent unacceptable stress in the inner surface of the second nut 148 when it is tightened.
  • a fluid for example diesel fuel
  • a fluid for example diesel fuel
  • the valve 102 is seated and the reciprocable plunger 34 is at the top of its stroke thereby uncovering the lower port 38 and allowing fuel to flow from the annular reservoir 92 into the pumping chamber 40 and fluid charge delivery passage 118.
  • the plunger 34 As the plunger 34 descends under the cooperative influence of the engine-driven rotatable camshaft 60, pushrod 58, pivotal rocker 56, and reciprocable follower 52, the plunger 34 first covers the lower port 38 and then pumps fuel through internal channels 46,48, metering groove 50, out through upper port 36, and back to the annular fluid reservoir 86 until the metering groove 50 no longer communicates with the upper port 36.
  • the modular design of the unit fluid pump-injector having one threaded joint which removably and sealably clamps the pump cylinder 32 between the pump cylinder retainer 70 and the housing 18 and another threaded joint which removably and sealably clamps the injector assembly 28 to the pump cylinder retainer 70, advantageously is less prone to high pressure fuel leakage or to having the plunger bind during assembly since fewer parts are stacked and clamped together.
  • the modular design also advantageously allows merely the second nut 148 to be threadably unfastened from the first nut 68 so that the injector assembly 28 can be removed, for easier servicing or replacement, from the small diameter bore 76 of the first nut 68 without requiring removal of the first nut 68 or altering the position or arrangement of the pump assembly 20 relative to the first nut 68.
  • the housing 18 may be threadably removed from the first nut 68 so that the pump assembly 20 can be removed from the large diameter bore 72 of ,the first nut 68 without requiring removal of the second nut 148 or altering the position or arrangement of the injector assembly 28 relative to the first nut 68.
  • the sandwiched frusto-conical end portions 154,142,144 of the second nut 148, case 106, and spray tip 108, respectively, which seat at surface 12 in the bore 14 of the cylinder head 16 provide a tight seal against carbon formation from the combustion chamber thus facilitating easier removal and servicing of the injector assembly 28.
  • the sandwiched frusto-conical end portions in seated cooperation with the tightened clamp 22 and cylinder head seat 12 create a preselected compressive stress state in the close proximity region of the spray tip 108 defining the cardioidal chamber 121 to prevent cracking and improve the fluid-pressure loading capability and fatigue life of that spray tip region.

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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)
EP83302947A 1982-06-18 1983-05-23 Injecteur-pompe combiné à un combustible Expired EP0097429B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US38963682A 1982-06-18 1982-06-18
US389636 1982-06-18

Publications (2)

Publication Number Publication Date
EP0097429A1 true EP0097429A1 (fr) 1984-01-04
EP0097429B1 EP0097429B1 (fr) 1987-07-22

Family

ID=23539074

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83302947A Expired EP0097429B1 (fr) 1982-06-18 1983-05-23 Injecteur-pompe combiné à un combustible

Country Status (5)

Country Link
EP (1) EP0097429B1 (fr)
JP (1) JPS595870A (fr)
CA (1) CA1188582A (fr)
DE (1) DE3372645D1 (fr)
MY (1) MY101909A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4585171A (en) * 1984-03-08 1986-04-29 Steyr-Daimler-Puch Aktiengesellschaft Fuel injection unit for a diesel engine cylinder
GB2268543A (en) * 1992-07-10 1994-01-12 Volkswagen Ag Mounting a fuel injection pump and nozzle unit on an i.c.engine cylinder head.
GB2311558A (en) * 1996-03-28 1997-10-01 Stanadyne Automotive Corp Fuel injection nozzle with compressive radial pre-loading
WO2016206835A1 (fr) * 2015-06-25 2016-12-29 Robert Bosch Gmbh Injecteur de carburant et procédé de montage d'un injecteur de carburant

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62117577U (fr) * 1986-01-20 1987-07-25

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2082808A (en) * 1934-09-10 1937-06-08 Murphy Diesel Company Ltd Fuel injection apparatus
US2408288A (en) * 1942-11-13 1946-09-24 Bendix Aviat Corp Fuel injection apparatus
US3006556A (en) * 1961-01-03 1961-10-31 Gen Motors Corp Unit fuel pump-injector
US3055593A (en) * 1960-05-02 1962-09-25 Walker Mfg Co Fuel injection nozzle

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5028573A (fr) * 1973-07-13 1975-03-24
DE2424800C2 (de) * 1974-05-22 1986-01-02 Daimler-Benz Ag, 7000 Stuttgart Einspritzgerät zum Einspritzen einer zusätzlichen, geringen Kraftstoffmenge in eine nach dem Schichtladungsprinzip arbeitende fremdgezündete Verbrennungskraftmaschine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2082808A (en) * 1934-09-10 1937-06-08 Murphy Diesel Company Ltd Fuel injection apparatus
US2408288A (en) * 1942-11-13 1946-09-24 Bendix Aviat Corp Fuel injection apparatus
US3055593A (en) * 1960-05-02 1962-09-25 Walker Mfg Co Fuel injection nozzle
US3006556A (en) * 1961-01-03 1961-10-31 Gen Motors Corp Unit fuel pump-injector

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4585171A (en) * 1984-03-08 1986-04-29 Steyr-Daimler-Puch Aktiengesellschaft Fuel injection unit for a diesel engine cylinder
GB2268543A (en) * 1992-07-10 1994-01-12 Volkswagen Ag Mounting a fuel injection pump and nozzle unit on an i.c.engine cylinder head.
GB2268543B (en) * 1992-07-10 1996-01-10 Volkswagen Ag Cylinder head,having a pumping nozzle unit,for an internal combustion engine
GB2311558A (en) * 1996-03-28 1997-10-01 Stanadyne Automotive Corp Fuel injection nozzle with compressive radial pre-loading
WO2016206835A1 (fr) * 2015-06-25 2016-12-29 Robert Bosch Gmbh Injecteur de carburant et procédé de montage d'un injecteur de carburant

Also Published As

Publication number Publication date
DE3372645D1 (en) 1987-08-27
CA1188582A (fr) 1985-06-11
JPS595870A (ja) 1984-01-12
EP0097429B1 (fr) 1987-07-22
MY101909A (en) 1992-02-15

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