Method and apparatus for regulating fuel injection timing and quantity

• US 4,884,549 A
• Filed: 06/08/1988
• Issued: 12/05/1989
• Est. Priority Date: 04/21/1986
• Status: Expired due to Term

• Current Assignee: Standayne Corporation
• Original Assignee: Stanadyne Automotive Holding Corporation (Stanadyne Holdings Incorporated)
• Inventors: Kelly, William W.
• Primary Examiner(s): Miller, Carl Stuart
• Application Number:
  US07/204,170
• Time in Patent Office: 545 Days
• Field of Search: 123/500, 123/506, 123/357, 123/358, 123/359, 123/458, 123/446, 123/501, 123/450, 417/282, 417/290, 417/462, 417/218
• US Class Current: 123/506
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/408 of the distributing type
• CPC Class Codes: F02M 2200/04 Fuel-injection apparatus having means for avoiding effect of cavitation, e.g. erosion
• CPC Class Codes: F02M 41/1411 characterised by means for varying fuel delivery or injection timing
• CPC Class Codes: F02M 59/366 Valves being actuated electrically
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An internal combustion engine fuel injection system having a reciprocating charge pump and a bidirectional flow, solenoid valve for precisely regulating the fuel injection timing by precisely regulating the intake charge quantity of fuel supplied to the charge pump during each intake stroke and for precisely regulating the fuel injection quantity by precisely regulating the spill termination of the high pressure delivery of fuel during each pumping stroke. An electrical controller having a data processor timely energizes and deenergizes the solenoid valve and adjusts the charge pump stroke timing, if adjustable, for adjusting the fuel injection timing and quantity. A start-of-pumping sensor or charge pump stroke timing sensor is used to provide a closed loop feedback, or in the alternative where the charge pump stroke is not adjustable, a calibrated input is used in lieu of a charge pump stroke timing sensor.

Claims

1. In an internal combustion engine fuel injection system having a charge pump with reciprocating pumping means and operating cam means providing periodic intake and pumping strokes of the pumping means to periodically receive an intake charge of fuel supplied at relatively low pressure and deliver fuel at relatively high pressure for injection of a charge of fuel, and regulating means for regulating the fuel injection timing and quantity of each injection charge of fuel, the improvement wherein the regulating means comprises electrical valve means connected to the charge pump and having open and closed positions and which, in the open position thereof, is operable to supply fuel to the charge pump during the intake stroke and to spill fuel from the charge pump during the pumping stroke, the electrical valve means being selectively electrically operable for selectively electrically opening and selectively electrically closing the electrical valve means, and control means actively governing the electrical operation of the electrical valve means during each intake stroke and during each pumping stroke, the control means selectively electrically closing the electrical valve means during each intake stroke to regulate the intake charge quantity of fuel supplied to the charge pump during each intake stroke and thereby regulate the fuel injection timing, the control means selectively electrically opening the electrical valve means during each pumping stroke to regulate the injected charge quantity by regulating the termination of said high pressure delivery of fuel.

2. A fuel injection system according to claim 1 wherein the charge pump comprises charge pump stroke timing means adjustable for adjusting the charge pump stroke timing of the intake and pumping strokes of the pumping means and wherein the control means selectively adjusts the charge pump stroke timing means and selectively electrically closes the electrical valve means during each intake stroke to regulate the intake charge quantity of fuel supplied to the charge pump, and thereby regulate the fuel injection timing, in accordance with the charge pump stroke timing.

3. A fuel injection system according to claim 1 further comprising an auxiliary rotary inlet valve for automatically supplying fuel to the charge pump only during an initial part of each intake stroke before the electric closure of the electrical valve means by said control means.

4. A fuel injection system according to claim 1 wherein the charge pump comprises a fuel passage between the electrical valve means and pumping means, an isolation shuttle mounted for reciprocation in the fuel passage to and from an extended limit position thereof and means biasing the isolation shuttle in one direction thereof to its extended limit position to supply fuel above a first pressure to the pumping means during its intake stroke, the pumping means being connected to hydraulically actuate the isolation shuttle in the opposite direction against said biasing means with fuel delivered by the pumping means during its pumping stroke, and one-way valve means for supplying fuel at a second pressure, less than said first pressure, to the pumping means during its intake stroke after the isolation shuttle reaches its extended limit position.

5. A fuel injection system according to claim 1 wherein the electrical valve means comprises an opening spring for urging the electrical valve means to said open position thereof.

6. A fuel injection system according to claim 1 wherein the control means comprises an injection timing sensor operable to generate an electrical, reference, injection timing signal and an electrical controller having a data processor connected for receiving the generated reference signals and connected for selectively electrically opening and closing the electrical valve means to precisely regulate the injection timing and quantity in accordance with the generated reference signals.

7. A fuel injection system according to claim 1 wherein the control means comprises a stroke timing sensor operable to generate an electrical, reference, injection timing signal and an electrical controller having a data processor connected for receiving the generated reference signals and connected for selectively electrically opening and closing the electrical valve means to precisely regulate the injection timing and quantity in accordance with the generated reference signals.

8. A fuel injection system according to claim 1 wherein the reciprocating pumping means comprises a rotor body having a plurality of radially extending bores and a reciprocating pumping plunger within each bore, the rotor body having an internal bidirectional flow passage connected to the pumping means, the electrical valve means comprising a bidirectional valve having a bidirectional flow, valve member shiftable within said internal passage of the rotor body between open and closed positions thereof and an electrical valve actuator selectively electrically operated by said control means for selectively electrically shifting said bidirectional flow, valve member between its said open and closed positions, said operating cam means being an annular cam surrounding the rotor body for reciprocating the pumping plungers as the rotor body rotates.

9. A fuel injection system according to claim 8 further comprising an auxiliary rotary inlet valve for automatically supplying fuel to the charge pump only during an initial part of each intake stroke of the pumping means before the closure of the bidirectional valve by the control means, the auxiliary valve comprising a valve port in the rotor body connected to the pumping means, and a plurality of angularly spaced fuel supply ports with which the valve port registers in sequence to supply, during each such registration, fuel to the pumping means during said initial part of the intake stroke of the pumping means.

10. A fuel injection system according to claim 8 wherein the valve member is mounted within said internal passage of the rotor body for rotation with the rotor body and to be shifted axially within the rotor body between open and closed positions thereof and wherein the electrical valve actuator comprises a fixed electrical driver selectively energized and deenergized by the control means and an armature mounted in axial alignment with the valve member and axially shiftable by electrical operation of the electrical driver with the control means to shift the valve member between its said open and closed positions.

11. A fuel injection system according to claim 8 wherein the valve member is a poppet valve member having a peripheral annulus permitting bidirectional flow through the bidirectional valve with the valve member in its open position.

12. A fuel injection system according to claim 10 wherein the armature engages an axial end face of the valve member to shift the valve member between its open and closed positions.

13. A fuel injection system according to claim 1, wherein the charge pump has a fixed charge pump stroke timing of the intake and pumping strokes of the pumping means and wherein the operating cam means comprises pumping ramp means, providing said periodic pumping strokes of the pumping means, with a generally constant effective slope.

14. A fuel injection system according to claim 1 wherein the operating cam means comprises intake ramp means with a relatively shallow slope and wherein the control means regulates the intake charge quantity by stroke-time inlet metering.

15. A fuel injection system according to claim 1 wherein the electrical valve means is a bidirectional flow, electrical valve.

16. A method of regulating the fuel injection timing and quantity of an internal combustion engine fuel injection system having a charge pump with reciprocating pumping means with periodic intake and pumping strokes to periodically receive an intake charge of fuel supplied at relatively low pressure and deliver fuel at relatively high pressure for injection of a charge of fuel, the method comprising the step of providing electrical valve means connected to the charge pump and having open and closed positions and which, in the open position thereof, is operable to supply fuel to the charge pump during the intake stroke and to spill fuel from the charge pump during the pumping strike, the electrical valve means being selectively electrically operable for selectively electrically opening and selectively electrically closing the electrical valve means, and the step of actively governing the electrical operation of the electrical valve means during each intake stroke and during each pumping stroke, the governing step comprising the step of selectively electrically closing the valve means during each intake stroke to regulate the intake charge quantity of fuel supplied to the charge pump and thereby regulate the fuel injection timing, the governing step comprising the step of selectively electrically opening the valve means during each pumping stroke to regulate the injected charge quantity by regulating the termination of said high pressure delivery of fuel.

17. A method of regulating the fuel injection timing and quantity according to claim 16 further comprising the step of regulating the charge pump stroke timing of the intake and pumping strokes of the pumping means.

18. A method of regulating the fuel injection timing and quantity according to claim 16 further comprising the step of generating a reference timing signal of the injection timing and regulating the electric closure of the electrical valve means in accordance with the timing of the generated reference signals.

19. A method of regulating fuel injection timing and quantity according to claim 16 wherein the charge pump has a rotary drive for effecting said reciprocation of the pumping means, wherein the step of actively governing the electrical operation of the electrical valve means comprises periodically generating reference timing signals including at least one reference timing signal during each cycle of reciprocation of the pumping means, periodically electronically determining a desired injection timing angle of rotation of the rotary drive after a respective reference timing signal for electrically closing the electrical valve means, periodically electronically determining a desired injection quantity angle of rotation of the rotary drive after a respective reference timing signal, measuring, during each cycle of reciprocation of the pumping means, the actual injection timing angle of rotation of the rotary drive after the respective reference timing signal and electrically closing the electrical valve means when the actual injection timing angle equals the desired injection timing angle and measuring, during each cycle of reciprocation of the pumping means, the actual injection quantity angle of rotation of the rotary drive after the respective reference timing signal and electrically opening the electrical valve means when the actual injection quantity angle equals the desired injection quantity angle.

20. A method of regulating fuel injection timing and quantity according to claim 19 wherein the reference timing signal generating step comprises generating a single reference timing signal during each cycle of reciprocation of the pumping means for regulating electrical closure and electrical opening of the electrical valve means.

21. A method of regulating fuel injection timing and quantity according to claim 20 wherein the single reference timing signal is generated during each cycle of reciprocation of the pumping means at a fixed predetermined reference point.

22. A method of regulating fuel injection timing and quantity according to claim 19 wherein the reference timing signal generating step comprises generating, during each cycle of reciprocation of the pumping means, separate injection timing and injection quantity reference timing signals for regulating electrical closure and electrical opening of the electrical valve means.

23. A method of regulating fuel injection timing and quantity according to claim 22 wherein the separate reference timing signals comprise an injection timing reference timing signal at a fixed predetermined reference point and an injection quantity reference timing signal of the actual fuel injection timing.

28. A method of regulating fuel injection timing and quantity according to claim 21 wherein fuel is supplied to the charge pump during each intake stroke via said bidirectional flow, electrical valve means and in addition via an auxiliary fuel supply valve through which the fuel supply is automatically terminated during each intake stroke prior to said precise electrical closure of said electrical valve means.

24. A method of regulating the fuel injection timing and quantity of an internal combustion engine fuel injection system having a charge pump with reciprocating pumping means and operating cam means having intake and pumping ramp means providing periodic intake and pumping strokes of the pumping means to periodically receive an intake charge of fuel supplied at relatively low pressure and deliver fuel at relatively high pressure for injection of a charge of fuel, the charge pump having a fixed charge pump stroke timing of reciprocation of said pumping means, the method comprising the step of providing bidirectional flow, electrical valve means connected to the charge pump and having open and closed positions and which, in the open position thereof, is operable to supply fuel to the charge pump during the intake stroke and to spill fuel from the charge pump during the pumping stroke, the electrical valve means being selectively electrically operable for selectively electrically opening and selectively electrically closing the electrical valve means, and the step of actively governing the electrical operation of the electrical valve means during each intake stroke and during each pumping stroke, the governing step comprising the step of precisely electrically closing the valve means during each intake stroke to regulate the intake charge quantity supplied to the charge pump during each intake stroke and thereby regulate the fuel injection timing, the governing step comprising the step of precisely electrically opening the valve means during each pumping stroke to regulate the injected charge quantity by regulating the termination of said high pressure delivery of fuel.

25. A method of regulating fuel injection timing and quantity according to claim 24, further comprising the step of generating a reference timing signal of the fuel injection timing during each pumping stroke and wherein the intake charge quantity is regulated during each intake stroke in accordance with the timing of the generated reference signals.

26. A method of regulating fuel injection timing and quantity according to claim 24, further comprising the step of generating a reference timing signal of the charge pump stroke timing and wherein the intake charge quantity is regulated during each intake stroke in accordance with the timing of the generated reference signals.

27. A method of regulating fuel injection timing and quantity of an internal combustion system having a charge pump with reciprocating pumping means and operating cam means for reciprocating the pumping means, the operating cam means having intake and pumping ramp means providing periodic intake and pumping strokes of the pumping means to periodically receive an intake charge of fuel supplied at relatively low pressure and deliver fuel at relatively high pressure for injection of a charge of fuel, the charge pump having an adjustable charge pump stroke timing of reciprocation said pumping means, the method comprising the step of providing bidirectional flow electrical valve means connected to the charge pump and having open and closed positions and which, in the open position thereof, is operable to supply fuel to the charge pump during the intake stroke and to spill fuel from the charge pump during the pumping stroke, the electrical valve means being selectively electrically operable for selectively electrically opening and selectively electrically closing the electrical valve means, the step of adjusting the charge pump stroke timing, and the step of actively governing step comprising the step of precisely electrically closing the valve means during each intake stroke to regulate the intake charge quantity supplied to the charge pump during each intake stroke and thereby regulate the fuel injection timing, the governing step comprising the step of precisely electrically opening the valve means during each pumping stroke to regulate the injected charge quantity by regulating the termination of said high pressure delivery of fuel in accordance with the fuel injection timing resulting from the charge pump stroke timing and the intake charge quantity supplied to the charge pump during the preceding intake stroke.