US3238934A - Liquid-fuel distributing means for internal combustion engines - Google Patents

Liquid-fuel distributing means for internal combustion engines Download PDF

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Publication number
US3238934A
US3238934A US354332A US35433264A US3238934A US 3238934 A US3238934 A US 3238934A US 354332 A US354332 A US 354332A US 35433264 A US35433264 A US 35433264A US 3238934 A US3238934 A US 3238934A
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United States
Prior art keywords
casing
valve
fuel
metering
block
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Expired - Lifetime
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US354332A
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English (en)
Inventor
Morris John Neville
Fishman Bernard
Bloom Gerald
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SU Carburetter Co Ltd
Simmonds Precision Products Inc
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SU Carburetter Co Ltd
Simmonds Precision Products Inc
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    • 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
    • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
    • F02M69/12—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel comprising a fuel-displaced free-piston for intermittently metering and supplying fuel to injection nozzles

Definitions

  • This invention relates to liquid-fuel metering pumps for supplying'a plurality of fuel-injection nozzles situated individually in the respective inlet ports or induction passages of a multi-cylinder, spark-ignition internal combustion engine. It is customary to provide such pumps either with separate metering chambers associated individually with each engine cylinder or with equivalent means, inherent in the pump, whereby equality of fuel distribution between all the fuel-injection nozzles is assured.
  • the instantaneous rate of fuel flow when supplied by a pump having the characteristics presupposed above, will vary, as between the conditions of idling and full power output, in a ratio of the order of l to 50, and consequently the instantaneous pressure-drop across the nozzle will vary approximately as the square of this ratio. If, therefore, the minimum nozzle pressure-drop required to provide an acceptably finely divided nozzle spray is, say, p.s.i., then this pressure-drop, under full load and speed operation of the engine, will rise to an inconveniently high value, with consequent excessive loading of the pump and nozzle lines.
  • a known expedient for ameliorating the state of affairs just described is the provision of relatively large nozzle orifices which impose very low pressure-drops under idling and light running conditions, and, to ensure the required spray quality of the discharge under these conditions, the admission of atmospheric air to a pulverizing region downstream of the nozzles.
  • This arrangement is unsatisfactory because, under full-throttle operation, particularly at low speeds, the pressure within the inlet ports or induction passages of the engine is not appreciably below atmospheric, and thus the inflow of pulverizing air is much diminished with consequent deterioration of the quality of the spray.
  • Another known expedient for achieving equal distribution of the fuel between all the fuel-injection nozzles, when these are supplied by a pump having the characteristics presupposed, consists in the provision of expansibletype nozzles such as to permit of a wide variation in the instantaneous rate of fuel flow accompanied by a relatively small variation in nozzle pressure-drop.
  • This type of nozzle is exemplified by one in which an outwardly opening pintle valve is held in spring-loaded contact with "ice a seating formed in the extremity of the nozzle body, the arrangement being such that a substantially constant pressure-drop is maintained across the valve seating for a Wide variation in the instantaneous rate of fuel flow, with a consequent acceptable pulverization of fuel.
  • spark-ignition, internal combustion engine a plurality of fuel-injection nozzles of the fixed-orifice type, situated individually in the respective inlet ports or induction passages of the engine, is supplied by at least one common chamber which periodically receives a metered and pressurized charge of fuel from a shuttle-plunger pump having, in addition to a metered fuel reservoir, a pressurized fuel reservoir which, under the control of valve means, is abruptly volumetrically contractible by elastic means to effect rapid delivery of the charge from the metered fuel reservoir ,to the common chamber at an approximately constant pressure.
  • the arrangement may either be such that all the injection nozzles are supplied simultaneously from one and the same common chamber (to which the fuel can be delivered by only a single duct); or, alternatively, it may be such that, instead of the single common chamber, there are two or more separate smaller chambers each common to, and supplying, its own group of the injection nozzles; these two chambers collectively being equivalent to employing a single larger chamber common to all the injection nozzles.
  • This characteristic may be defined in terms of the rapidity with which a pressurized and metered quantity of fuel is made available for supply to the common chamber at the commencement of each delivery phase of the pump, together with the circumstance that an approximately constant pressure is active to impel this metered quantity of fuel into the common chamber and thence through the nozzle lines and nozzles.
  • the means whereby the above-mentioned volumetrically contractible pressurized fuel reservoir is placed in communication with the common chamber from which the nozzles are supplied must be such that an extremely rapid rise of pressure within that chamber is assured, notwithstanding that the engine speed, and consequently the pump speed, may be very low; and that this pressure will be sustained at an approximately constant value throughout the discharge interval of the nozzles, thus ensuring, during this interval, an approximately constant pressure-drop across the fixed orifices of the nozzles which is of a value adequate to provide pulverization of their discharge notwithstanding that the nozzle orifices are sufficiently large to accommodate the fuel flow at maximum power conditions under the moderate and approximately constant pressure provided, and within the interval of time available for completion of the injection phase, even When the engine is operating at its maximum speed and load.
  • any type of nozzle ing good fuel pulverization may be employed.
  • the swirlchamber type of nozzle is particularly suitable.
  • fuel enters a small chamber through one or more tangentially disposed metering orifices, and emerges in a swirling state through a further metering orifice concentric with the chamber.
  • injection pulses directed into the inlet ports or induction passages of the engine occur simultaneously. Therefore, although such a pulse may be delivered into one or more'of the inlet ports or induction passages during the induction phase-of that port or ports, injection pulses, in the case of other ports or induction passages, will occur during phases of the engine cycle other than the induction phase. So long as a high degree of pulverization is provided by the nozzles, however, this asymmetry of phasing (as between the various engine cylinders) is known to have no significant effect upon engine operation, the only essential requirement being that at least one injection pulse must be supplied to each of the ports per engine cycle.
  • FIGURE 1 shows, in sectional elevation, a liquid-fuel metering pump, for use in carrying the invention into effect, together with some of its associated equipment;
  • FIGURE 2 is a similar illustration of a variant of the pump shown in FIGURE 1, having dual outlets each of which serves its own group of fuel-injection nozzles; and FIGURE 3 is a section on the line xx in FIGURE 2.
  • the body of the metering pump 1 comprises a generally cylindrical housing 2 surmounted by a detachable cap 3, these two components having co-operating bolting flanges 4 and 5 respectively.
  • the housing 2 contains a chamber 6 of annular :form, to which liquid fuel, drawn from a supply tank (not shown), is delivered through a pipe 7 by a positive-displacement extraneous pump 8 which has a delivery capacity in excess of the maximum demand of the engine being served.
  • the chamber 6, which conveniently may be designated an expansible pressure accumulator, is elastically distensi'ble and contractible, being sealed at one end by a resilient spring-loaded diaphragm 9.
  • This diaphragm which may be made of neoprene or any other fuel-resistant elastomeric material, is clamped peripherallybetween the bolting flanges 4 and 5, and is loaded by a helical compression spring 10 that is trapped between an annular channel abutment 11 on the diaphragm and the top of the cap 3.
  • the pressurized fuel reservoir 6 has an accurately flat internal facing '12 having two ports or metering chambers 13 and 14 which, by means of ducts 15 and 16 respectively, are in permanent communication with opposite ends of a cylindrical bore 17 that contains a closely fitting shuttle-plunger 18 of stainless steel or other non-corrodible material.
  • the pressurized fuel reservoir 6 is, of course, safeguarded by a pressure-relief valve 19.
  • This valve which controls a relief duct 20 passing through the diaphragm 9, is set to permit a normal working pressure of about 150 p.s.i. in the pressurized fuel reservoir 6; fuel ejected from the relief outlet 21 being returned to the supply tank by way of a pipe (not shown).
  • the latter is spring-loaded axially so that the disc valve 22 isnipped between its co-operating stationary facings 12 and 25.
  • the spring-loading of the block 26 is effected by a helical compression spring 27 trapped between the top of the cap 3 and an abutment flange 28 on a cylindrical block 29 that is coaxial with, and surmounts, the metering block 26.
  • the central zone of the diaphragm 9 is clamped between the two blocks 26 and 29, which are secured together by a central bolt 30.
  • the upper portion ofthe block 29 projects through an opening 3'1 in the cap 3.
  • Each face of the disc valve 22 contains an annular groove, and these two grooves, 32 and 33 respectively, are in permanent communication with each other by way of a duct 34.
  • the annular groove 33 co-operates with a port 35 in the facing 25 of the cylindrical block 26. From the port 35, and by way of a corresponding aperture in the diaphragm 9, a duct 36 in the block 29 affords communication with a single pipe 37 which leads into a chamber 38; this being the common chamber mentioned earlier, and from which individual lines, as at 39, lead'to the respective fuel-injection nozzles, as at 40, of the fixed-orifice, swirl-chamber type.
  • the arrangement is such that as soon as one of the two ports 13 or 14 in the internal facing of the pressurized fuel reservoir 6 begins to become uncovered by the moving rim of the epicyclic valve 22, pressurized fuel (sustained by the elastic contractibility of its reservoir 6) rushes through that port and abrutly impels the shuttleplunger '18 until this is arrested by a stroke-limiting stop.
  • the port 13 has become uncovered by the valve 22, whereas this valve has cut off communication between the pressurized fuel reservoir 6 and the port 14; the latter now being open to the annular groove 32 in the valve 22.
  • the shuttle-plunger 18 is being impelled from right to left, by pressurized fuel flowing through the duct 15, and is in process of delivering a metered quantity of fuel ('by Way of the duct 16, the port 14 and so on) to the common chamber 38, and thence to all of the injection nozzles simultaneously.
  • the shuttleplunger- 18 Upon termination of the delivery phase, the shuttleplunger- 18 is impellcdback to its initial position against an adjustable stop 41, due to the continued movement of the epicyclic valve 22 causing a reversal of the fiow of pressurized fuel through the ports 13 and 14. That is to say, the common chamber 38 receives a metered quantity of fuel at every stroke of the shuttle-plunger 18. The displacement volume of the latter constitutes a metered fuel reservoir.
  • the adjustable stop 41 determines the quantity of fuel metered per stroke of the shuttle-plunger 18, and is adjustable by a cam 42 and associated control mechanism (not shown) that forms no part of the invention.
  • the design of the metering pump 1A is such that, by way of dual outlets 43 and 44, and their associated pipes 45 and 46 respectively, the shuttle-plunger 18 is enabled to supply alternating pulsations of pressurized and metered fuel to two independent sub-common chambers 47 and 48, each of which supplies half the total number of engine cylinders.
  • FIGURES 2 and 3 which remain the same as in FIGURE 1 are identified by the same reference numerals; and the suflix A is employed to indicate a modification of the part similarly numbered in FIG- URE 1.
  • the disc valve 22A (which replaces the corresponding valve 22 of FIGURE 1) has peripheral gear teeth 49 which mesh with a similar set of teeth 50 formed on a stationary annulus 51 which, as depicted, is integral and concentric with the cylindrical housing 2A.
  • the valve 22A also has a number of pairs of ports 52 and 53 on its lower and upper surfaces respectively, each of such pairs being interconnected by a duct 54. If the numbers of gear teeth 49 and 50 provided on the valve disc 22A and housing 2A respectively, are such that the valve disc performs 1/n of a revolution upon its own axis for each revolution of the driveshaft 23 and eccentric 24, then the number of pairs of ports 52 and 53 provided is made equal to n.
  • the ratio of the numbers of teeth 50 and 49 is 9 to 8 and, consequently, the valve disc 22A will rotate by one-eighth of a revolution for each revolution of the drive-shaft 23. Therefore, eight pairs of the ports 52 and 53 are provided, one of these pairs of ports coming, in sequence, into co-operation with each of the single pair of oppositely placed stationary ports 35 and 55, and 14, 13, provided in the facings 25 and 12 respectively, on each rotation of the drive'shaft 23.
  • ducts 36 and 56 in the block 29A lead to the respective outlets 43 and 44.
  • the arrangement is such that as soon as one of the two ports 13 or 14 in the internal facing 12 of the pressurized fuel reservoir 6 begins to become uncovered by the moving rim of the valve 22A, pressurized fuel (sustained by the elastic contractibility of its reservoir 6) rushes through that port and abruptly impels the shuttle plunger 13 until this is arrested by a stroke-limiting stop.
  • the port 14 Simultaneously, or somewhat prior to the uncovering of the port 13, the port 14 has been placed placed, via one of the pair of ports 52 and 53 and their interconnecting duct 54, in communication with the port 35 and its continuation duct 36 and thence, via the pipe 45, with the sub-common chamber 47.
  • the fuel received by this chamber is discharged simultaneously by the associated group of three injection nozzles 40.
  • a further half-revolution of the drive-shaft 23 results in restoration of the situation depicted in FIGURE 2 and, therefore, in a further injection by the group of nozzles 40 served by the sub-common chamber 47.
  • the ports 52 and 53 will have rotated, with respect to the centre line of the valve 22A, by one-sixteenth of a revolution only, and will thus be somewhat out of relative register with the pair of ports 14 and 35 and the pair 13 and 55, with which they alternately establish communication.
  • a fuel injection pump for an internal combustion engine comprising a casing having a liquid-fuel inlet port communicating with an expansible pressure accumulator chamber, a ported valve mounted within the casing for rotary motion and formed with seating faces on opposite sides thereof, a metering block including at least two outlet ports mounted for movement within the casing and having one surface adjacent to one seating face of said valve and shaped complementally thereto, a flanged cap superposed on said metering block, means defining openings therein in coincidence with the ports in said block and a diaphragm interposed between said flange cap and said block, said valve being disposed between said block and one end of the casing with its other seating face in contact with said end of the casing, resilient means disposed within said casing for urging said metering block toward one end of the casing to maintain intimate contact between the casing, the valve and the metering block, plural metering chambers in said casing having one end opening adjacent to the seating face of said valve with the other ends of said chambers

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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)
US354332A 1962-06-27 1964-03-24 Liquid-fuel distributing means for internal combustion engines Expired - Lifetime US3238934A (en)

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GB24602/62A GB972446A (en) 1962-06-27 1962-06-27 Liquid-fuel distributing means for internal combustion engines

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FR (1) FR1385487A (fr)
GB (1) GB972446A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3359962A (en) * 1965-06-24 1967-12-26 Citroen Sa Andre Distributing means for a fuel injection pump
US3654908A (en) * 1968-07-30 1972-04-11 Dewty Technical Developments L Fuel injection systems

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0658100B2 (ja) * 1986-02-06 1994-08-03 日本電装株式会社 分配型燃料噴射ポンプ
US6125813A (en) * 1997-06-09 2000-10-03 Patrick Power Products, Inc. Prechamber combustion for a rotary diesel engine

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892453A (en) * 1956-12-13 1959-06-30 Bosch Gmbh Robert Fuel injection systems for multicylinder engines
US3124116A (en) * 1964-03-10 Fuel-injection pumps for internal combustion engines

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124116A (en) * 1964-03-10 Fuel-injection pumps for internal combustion engines
US2892453A (en) * 1956-12-13 1959-06-30 Bosch Gmbh Robert Fuel injection systems for multicylinder engines

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3359962A (en) * 1965-06-24 1967-12-26 Citroen Sa Andre Distributing means for a fuel injection pump
US3654908A (en) * 1968-07-30 1972-04-11 Dewty Technical Developments L Fuel injection systems

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FR1385487A (fr) 1965-01-15
GB972446A (en) 1964-10-14

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