EP0071800A2 - Pompe d'injection de carburant pour moteur à combustion interne comprenant un dispositif de décharge perfectionné de l'excès de carburant - Google Patents

Pompe d'injection de carburant pour moteur à combustion interne comprenant un dispositif de décharge perfectionné de l'excès de carburant Download PDF

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Publication number
EP0071800A2
EP0071800A2 EP82106366A EP82106366A EP0071800A2 EP 0071800 A2 EP0071800 A2 EP 0071800A2 EP 82106366 A EP82106366 A EP 82106366A EP 82106366 A EP82106366 A EP 82106366A EP 0071800 A2 EP0071800 A2 EP 0071800A2
Authority
EP
European Patent Office
Prior art keywords
fuel
free piston
injection pump
compression chamber
chamber
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Withdrawn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
EP82106366A
Other languages
German (de)
English (en)
Other versions
EP0071800A3 (fr
Inventor
Yoshikazu Hoshi
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Publication of EP0071800A2 publication Critical patent/EP0071800A2/fr
Publication of EP0071800A3 publication Critical patent/EP0071800A3/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Withdrawn legal-status Critical Current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
    • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
    • F02M41/08—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined
    • F02M41/14—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons
    • F02M41/1405—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons pistons being disposed radially with respect to rotation axis
    • F02M41/1411—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons pistons being disposed radially with respect to rotation axis characterised by means for varying fuel delivery or injection timing
    • 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
    • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
    • F02M41/08—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined
    • F02M41/14—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons
    • F02M41/1405—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons pistons being disposed radially with respect to rotation axis
    • F02M41/1411—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined rotary distributor supporting pump pistons pistons being disposed radially with respect to rotation axis characterised by means for varying fuel delivery or injection timing
    • F02M41/1422—Injection being effected by means of a free-piston displaced by the pressure of fuel
    • 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
    • F02M59/32—Varying fuel delivery in quantity or timing fuel delivery being controlled by means of fuel-displaced auxiliary pistons, which effect injection

Definitions

  • the present invention relates to a fuel injection pump used in an internal combustion engine especially a diesel engine and more particularly to a fuel injection pump having an excess fuel discharger.
  • a typical conventional fuel injection pump has a mechanical constitution using a governor, a spark advance system and the like in order to control both the amount of fuel to be injected and injection timing.
  • An object of the present invention is to provide a fuel injection pump for an internal combustion engine capable of electrically controlling both the amount of fuel to be injected and injection timing and further capable of injecting fuel stably and accurately.
  • Another object of the present invention is to provide a fuel injection pump for an internal combustion engine having a compact construction.
  • a fuel injection pump arranges such that a movable free piston is provided in a high-pressure fuel chamber, and a first chamber partitioned by the piston is supplied with fuel related to the amount of fuel to be injected, while a second chamber is supplied with fuel related to injection timing, wherein the abovementioned free piston is provided with a valve mechanism which opens when the piston moves upon the completion of injection of fuel in order to abruptly release the fuel for injection timing control in the second chamber.
  • Fig. 1 shows a fuel injection pump according to the present invention.
  • the basic constitution thereof is disclosed in the preceding application (U.S.Application filed on September 22, 1981: European Patent Application No. 81107263.6 filed on September 15, 1981).
  • a rotor 1 is rotated by means of a driving shaft (not shown) rotating in synchronism with an engine, while a pair of plungers 2a, 2b are housed in a bore laterally penetrating through the left end part of the rotor 1. Outside the plungers 2a, 2b, roller shoes 8a, 8b and rollers 9a, 9b are placed respectively. These plungers 2a, 2b, roller shoes 8a, 8b and rollers 9a, 9b rotate with the rotor 1.
  • a cam ring 3 on the peripheries of the rollers 9a, 9b is fitted in an outermost housing 10. Moreover, the rotorlrotates inside a sleeve 42 mounted in a sleeve holder 41 secured to the housing 10.
  • the inside of the rotor 1 is divided into a first compression chamber 4 and a second compression chamber 6, and a free piston 5 is placed therebetween, the right end of the second compression chamber 6 being sealed with a stopper 7.
  • the second compression chamber 6 communicates with a delivery passage 23 formed in the radial direction of the rotor 1, and a second release passage 12 is provided correspondingly to a second fixed passage 14 in the sleeve 42.
  • a first release passage 11 communicating with the first compression chamber 4 is provided correspondingly to a first fixed passage 13 in the sleeve 42, and an overflow port 29 is provided in the lower part of the first compression chamber 4, connecting with a discharge passage 32 through overflow passages 30, 31.
  • a fuel supply port 43 is formed, and the fuel introduced therefrom fills the chambers housing the valve bodies 17a, 17b of the solenoid valves 15, 16 respectively and the inside of the rotor 1.
  • reference numerals 22a, 22b designate terminals of the coils 19a, 19b respectively, and reference numerals 24 and 25 denote an outlet passage and a connection port respectively.
  • a reference numeral 27 designates a detector with an annular permanent magnet secured to an end part of the sleeve holder 41, and a pulser 26 mounted on the rotor 1 is inserted inside the detector 27.
  • the pulser 26 is a magnetic body provided with a-projection on its periphery and outputs a rotation signal from detection terminals 28 when a magnetic path is interrupted through the rotation of the pulser 26 with the rotor 1, thereby allowing the rotation position and speed of the rotor 1 to be detected.
  • each of these Figs. corresponds to a sectional view of Fig. 1 taken along the line II - II, showing the fuel injection pump in an operating state.
  • the right side part (b) of each Fig. shows the fuel passage relationship between the rotating rotor 1-and the sleeve 42 housing the same and the position of the free piston 5.
  • Fig. 2 the start of supply of fuel to be injected is shown, and the plungers 2a, 2b are moving outward.
  • Fig. 2 (a) because the rollers 9a, 9b have moved from the radially protruded portions to the radially recessed portions of the inner surface of the cam ring 3 and the pressure in the first compression chamber 4 is reduced, the free piston 5 moves in the direction of an arrow, reducing the pressure in the second compression chamber 6. Consequently, fuel to be injected is sucked through the second release passage 12 and the second fixed passage 14. Because the valve body 17b allows the passage 14 to be opened at this time, the compressed fuel from the fuel injection pump flows into the second compression chamber 6. In other words, this is a step of sucking the fuel to be injected.
  • the amount of fuel to be injected is controlled according to the opening period of time of the solenoid valve body 17b, i.e., the electric signal applied to the solenoid valve 16.
  • Fig. 3 shows the start of supply of the fuel for regulating injection timing after the completion of suction of the fuel to be injected.
  • the free piston 5 is suspended and the valve body 17a is in an opening state.
  • the plungers 2a, 2b further reduce the pressure in the first compression chamber 4, so that the fuel for regulating injection timing is sucked through the first fixed passage 13 and the first release passage 11.
  • the amount of the fuel is also controlled by means of the valve body 17a of the solenoid valve 15 controlled electrically. It is also possible to make the valve bodies 17a, 17b simultaneously open their corresponding passages for introducing fuel.
  • Fig. 4 shows the completion of supply of the fuel for regulating injection timing.
  • the plungers 2a, 2b and the free piston 5 are suspended, and both the valve bodies 17a, 17b are in a closing state.
  • Fig. 5 shows the start of injection of fuel. Because the rollers 9a, 9b are led to the protruded portions of the cam ring 3 respectively at this time, the plungers 2a, 2b start approaching to each other. Consequently, the free piston 5 moves in the direction of an arrow, i.e., rightward, pumping the fuel in the second compression chamber 6 to the connection port 25 in Fig. 1 through the delivery passage 23 and the oulet passage 24. Because the pipe attached to the connection port 25 communicates with a cylinder of an internal combustion engine, a given amount of fuel is supplied thereto.
  • Fig. 6 shows the start of discharge of excess fuel after the completion of injection of fuel. Because when the free piston 5 has moved to the right limit the overflow port 29 is exposed, the compressed excess fuel for regulating injection timing flows out through the overflow passage 30. The fuel flows out to the low-pressure portion inside the housing 10 through the overflow passage 31 in the sleeve holder 41 shown in Fig. 1, which exactly shows this state.
  • Fig. 7 shows the completion of discharge of the excess fuel. Although suspending, the free piston 5 is about to move into the state shown in Fig. 2 to suck the fuel to be injected. It may be understood from the above description that a series of fuel suction and injection operations are performed during a 90-degree turn of the rotor 1. Because the engine in this case has four cylinders, fuel is injected into all the cylinders during one full turn of the rotor 1. In case of a three-cylinder engine, the fuel injection pump is arranged such that all the three cylinders are supplied with fuel during one full turn of the rotor 1. In addition, the fuel sucked into the first compression chamber 4 is fuel for regulating what is called injection timing. Therefore, the fuel sucked into the second compression chamber 6 is actually injected.
  • Fig. 8 is a sectional view of an essential part of the fuel injection pump according to the present invention, particularly showing the free piston 5 thereof.
  • the same parts in Fig. 1 and Fig. 8 have the same symbols respectively.
  • valve body 51 is housed in the free piston 50 in this preferred embodiment, the valve body 51 and the free piston 50 are hermetically fitted to each other. Therefore, no fuel moves from the first compression chamber 4 to the second compression chamber 6. Moreover, being pressed by a spring 53 retained by a ring 54, the collar portion of the valve body 51 housed in the free piston 50 closely contacts with the valve seat, preventing the fuel in the first compression chamber 4 from flowing out through a discharge port 52, the overflow port 29 and the overflow passage 30.
  • the cross-sectional area of the passage through which fuel flows is 1.26 mm 2 . Moreover, the fuel passing through the passage can be easily and speedily discharged through the discharge port 52, the overflow port 29 and the overflow passage 30, which have cross-sectional areas larger than this.
  • a slight movement of the free piston 50 makes it possible to speedily discharge the excess fuel. Because the injection end is taken place at a fixed position of the free piston 50, it is easy to set the discharge port 52 so as to face to the overflow port 29.
  • the fuel injection pump according to the present invention is arranged such that the valve body 51 with the collar is placed inside the free piston 50 thereof, and the projected end of the valve body contacts with the stopper 7 at a maximum movement of the free piston 50, so that even when the collar is slightly separated from the seat portion, it is possible to discharge a relatively large amount of the excess fuel in the first compression chamber 4 in a short period of time. Accordingly, it is also possible to improve the accuracy in controlling the amount of the fuel injected from the second compression chamber 6.
  • the free piston 50 receiving pressure rightward around when the delivery passage 23 is opened, the free piston 50 is restrained from vibrating when the excess fuel is discharged, and because the pressure in a high-pressure pipe leading to an injection valve is speedily lowered and stabilized, it is useful for preventing undesired injection when no fuel is needed, i.e., the secondary injection or the like. Accordingly, it is possible to obtain such an advantageous effect as to improve the stability in injection of fuel.

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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)
EP82106366A 1981-08-10 1982-07-15 Pompe d'injection de carburant pour moteur à combustion interne comprenant un dispositif de décharge perfectionné de l'excès de carburant Withdrawn EP0071800A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP125686/81 1981-08-10
JP12568681A JPS5827873A (ja) 1981-08-10 1981-08-10 燃料噴射ポンプの余剰燃料排出装置

Publications (2)

Publication Number Publication Date
EP0071800A2 true EP0071800A2 (fr) 1983-02-16
EP0071800A3 EP0071800A3 (fr) 1984-01-18

Family

ID=14916166

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82106366A Withdrawn EP0071800A3 (fr) 1981-08-10 1982-07-15 Pompe d'injection de carburant pour moteur à combustion interne comprenant un dispositif de décharge perfectionné de l'excès de carburant

Country Status (2)

Country Link
EP (1) EP0071800A3 (fr)
JP (1) JPS5827873A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0073410A2 (fr) * 1981-08-28 1983-03-09 Hitachi, Ltd. Pompe d'injection de combustible du type distributrice
EP0075883A2 (fr) * 1981-09-28 1983-04-06 Hitachi, Ltd. Pompe d'injection de combustible pour moteurs à combustion interne

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3427979A (en) * 1966-03-22 1969-02-18 Cav Ltd Liquid fuel pumping apparatus for supplying fuel to internal combustion engines
US3489093A (en) * 1968-09-11 1970-01-13 Cav Ltd Liquid fuel pumping apparatus
US3704963A (en) * 1971-02-03 1972-12-05 Stanadyne Inc Fuel pump
GB2012360A (en) * 1978-01-16 1979-07-25 Bendix Corp Fuel injector

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3427979A (en) * 1966-03-22 1969-02-18 Cav Ltd Liquid fuel pumping apparatus for supplying fuel to internal combustion engines
US3489093A (en) * 1968-09-11 1970-01-13 Cav Ltd Liquid fuel pumping apparatus
US3704963A (en) * 1971-02-03 1972-12-05 Stanadyne Inc Fuel pump
GB2012360A (en) * 1978-01-16 1979-07-25 Bendix Corp Fuel injector

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0073410A2 (fr) * 1981-08-28 1983-03-09 Hitachi, Ltd. Pompe d'injection de combustible du type distributrice
EP0073410B1 (fr) * 1981-08-28 1987-05-06 Hitachi, Ltd. Pompe d'injection de combustible du type distributrice
EP0075883A2 (fr) * 1981-09-28 1983-04-06 Hitachi, Ltd. Pompe d'injection de combustible pour moteurs à combustion interne
EP0075883B1 (fr) * 1981-09-28 1986-01-29 Hitachi, Ltd. Pompe d'injection de combustible pour moteurs à combustion interne

Also Published As

Publication number Publication date
EP0071800A3 (fr) 1984-01-18
JPH02544B2 (fr) 1990-01-08
JPS5827873A (ja) 1983-02-18

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Inventor name: HOSHI, YOSHIKAZU