EP0458529A1 - Appareil de pompage de combustible - Google Patents

Appareil de pompage de combustible Download PDF

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Publication number
EP0458529A1
EP0458529A1 EP91304424A EP91304424A EP0458529A1 EP 0458529 A1 EP0458529 A1 EP 0458529A1 EP 91304424 A EP91304424 A EP 91304424A EP 91304424 A EP91304424 A EP 91304424A EP 0458529 A1 EP0458529 A1 EP 0458529A1
Authority
EP
European Patent Office
Prior art keywords
bore
plunger
fuel
cylinder
piston
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Withdrawn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
EP91304424A
Other languages
German (de)
English (en)
Inventor
Derek Wallace Tomsett
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.)
ZF International UK Ltd
Original Assignee
Lucas Industries Ltd
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 Lucas Industries Ltd filed Critical Lucas Industries Ltd
Publication of EP0458529A1 publication Critical patent/EP0458529A1/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Withdrawn legal-status Critical Current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
    • 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
    • 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
    • F02M59/24—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke
    • 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
    • F02M59/24—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke
    • F02M59/26—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke caused by movements of pistons relative to their cylinders

Definitions

  • This invention relates to a fuel pumping apparatus of the kind comprising a plunger reciprocable within a bore, an outlet from one end of the bore, a port formed in the wall of the bore and a groove formed on the plunger, the groove communicating with said one end of the bore and having an inclined control edge whereby the angular setting of the plunger within the bore determines the instant during the inward movement of the plunger at which the port is placed in communication with the one end of the bore to terminate flow of fuel through the outlet.
  • Such pumping apparatus is well known in the art and in order to achieve a rapid reduction in the pressure in the one end of the cylinder so that the flow of fuel through the outlet is terminated quickly, the port has to be large to achieve a high rate of flow of fuel as the port is progressively uncovered. Increasing the size of the port to achieve the required rate of flow of fuel leads to an increase in the leakage of fuel along the working clearance between the wall of the bore and the plunger. The rate of leakage of fuel also increases as the pressure at which fuel delivered through the outlet is increased.
  • valve which can be opened to allow fuel to escape from the one end of the bore.
  • the separate valve can be operated electrically but this involves a complex electronic control system or it may be operated mechanically or hydraulically.
  • Mechanical actuation of the valve can possibly involve the addition of a further cam in addition to that which is required to actuate the pumping plunger and in the case of hydraulic operation examples of apparatus are known in which an additional plunger is provided which produces a control pressure specifically to actuate the valve.
  • the object of the present invention is to provide an apparatus of the kind specified in a simple and convenient form.
  • an apparatus of the kind specified comprises a cylinder having an end wall, an actuating piston slidable in said cylinder and resiliently biased towards said end wall, a spill passage extending from said one end of the bore into the cylinder through said end wall, a valve member movable by the piston for controlling the flow of fuel through said spill passage and passage means connecting said port with said cylinder whereby when during the inward movement of the pumping plunger, the port is uncovered by the control edge, fuel will flow into the cylinder to effect movement of the piston and valve member thereby allowing fuel flow through said spill passage into said cylinder.
  • the apparatus comprises a housing 10 in which is formed a bore 11. Communicating with one end of the bore is an outlet 12 which in use is connected to an injection nozzle of an associated engine.
  • a conventional form of delivery valve may be incorporated in the outlet.
  • a pumping plunger 13 Slidable within the bore 11 is a pumping plunger 13 which is driven inwardly towards the one end of the bore by means of an engine driven cam not shown.
  • the plunger is moved outwardly by means of a return spring and the angular setting of the plunger within the bore can be adjusted in known manner.
  • a filling port 14 which in use, is connected to a source of fuel at low pressure.
  • the port 14 is uncovered to the one end of the bore towards the end of the outward movement of the plunger 13.
  • a control port 15 which is connected to one end of a cylinder 16 formed in the housing 10.
  • a seating 18 which is located about a spill passage 19 extending into the cylinder from the one end of the bore and for engagement with the seating there is provided a valve member 20 which is mounted on a piston 21 slidable in the cylinder.
  • the piston is biased towards the one end of the cylinder by means of a coiled compression spring 22 and the end of the cylinder which contains the spring, is vented.
  • a groove 23 which is provided with an inclined control edge.
  • the groove 23 communicates with the one end of the bore by way of a passage in the plunger.
  • the initial inward movement of the plunger will displace fuel from the bore through the filling port 14 however, as soon as this port is covered by the plunger the fuel in the one end of the bore will be pressurised and displaced through the outlet 12 to the associated engine.
  • This flow of fuel continues until the inclined control edge of the groove 23 uncovers the control port 15 and as soon as this occurs, fuel at the high pressure in the one end of the bore 11 flows into the cylinder to effect an initial displacement of the piston 21 against the action of its spring.
  • the displacement of the piston lifts the valve member 20 from the seating and fuel can then flow from the one end of the bore through the spill passage 19 into the cylinder and this flow of fuel continues until the plunger has completed its inward movement.
  • the rapid flow of fuel from the one end of the bore means that the pressure of fuel supplied to the associated injection nozzle falls very quickly and the valve member in the nozzle can therefore close quickly. In some instances it may be desirable to restrict the rate at which the pressure of fuel falls and this can be achieved by providing a restriction 35 in the passage through which the end of the cylinder 16 containing the spring 22 is vented.
  • the piston is provided with an axial bore 25 which communicates with the spill passage 19 by way of a central drilling in the valve member 20.
  • the bore 25 is occupied by a reaction plunger 26 and the diameter of the bore 25 is chosen so that it is slightly smaller than the effective seat diameter of the seating 18.
  • the pressure of fuel in the bore 25 acts upon the valve member to substantially pressure balance the valve member so that the force which requires to be exerted by the spring 22 can be reduced.
  • the sleeve defines a control port 29 which is the equivalent of the control port 15 in the example of Figure 1 and in addition, on its internal surface it defines a circumferential groove 30 which is the equivalent of the filling port 14, the groove 30 being in constant communication with a fuel supply passage 31.
  • the plunger 27 is modified by an extension of the axial drilling 32 which is connected to the groove 23, the extended portion of the drilling being connected by cross drillings 33 to the exterior surface of the piston.
  • the drillings 33 communicate with the groove 30 towards the end of the outward movement of the plunger, to replenish the fuel which has flowed to the associated engine.
  • the space defined between the sleeve 28 and the underside of the enlarged portion of the plunger is vented through a passage 34.
  • the outlet 12 is connected to a fuel injection nozzle of an associated engine.
  • the apparatus can however be utilised to supply fuel to a multi cylinder engine in which case a distributor member is interposed between the outlet 12 and the injection nozzles of the engine.
  • a distributor member is interposed between the outlet 12 and the injection nozzles of the engine.
  • outlet 12 is connected directly to a fuel injection nozzle
  • the usual form of delivery valve can be omitted and the pressure in the pipeline connecting the outlet 12 with the nozzle controlled using the trailing flank of the cam lobe which actuates the pumping plunger.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP91304424A 1990-05-23 1991-05-16 Appareil de pompage de combustible Withdrawn EP0458529A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9011533 1990-05-23
GB909011533A GB9011533D0 (en) 1990-05-23 1990-05-23 Fuel pumping apparatus

Publications (1)

Publication Number Publication Date
EP0458529A1 true EP0458529A1 (fr) 1991-11-27

Family

ID=10676426

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91304424A Withdrawn EP0458529A1 (fr) 1990-05-23 1991-05-16 Appareil de pompage de combustible

Country Status (2)

Country Link
EP (1) EP0458529A1 (fr)
GB (1) GB9011533D0 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2253445A (en) * 1991-03-07 1992-09-09 Lucas Ind Plc Fuel pumping apparatus
WO1993006361A1 (fr) * 1991-09-14 1993-04-01 Lucas Industries Public Limited Company Pompe d'injection de carburant

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0121689A1 (fr) * 1983-03-05 1984-10-17 Robert Bosch Gmbh Dispositif d'injection du combustible pour moteurs à combustion interne
WO1988002068A1 (fr) * 1986-09-09 1988-03-24 Nova-Werke Ag Dispositif d'injection de carburant pour un moteur diesel

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0121689A1 (fr) * 1983-03-05 1984-10-17 Robert Bosch Gmbh Dispositif d'injection du combustible pour moteurs à combustion interne
WO1988002068A1 (fr) * 1986-09-09 1988-03-24 Nova-Werke Ag Dispositif d'injection de carburant pour un moteur diesel

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2253445A (en) * 1991-03-07 1992-09-09 Lucas Ind Plc Fuel pumping apparatus
US5478213A (en) * 1991-09-13 1995-12-26 Lucas Industries Public Limited Company Fuel injection pump
WO1993006361A1 (fr) * 1991-09-14 1993-04-01 Lucas Industries Public Limited Company Pompe d'injection de carburant

Also Published As

Publication number Publication date
GB9011533D0 (en) 1990-07-11

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19920528