System and method for acquiring pressure data from a fuel accumulator of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9903306-B2
Application number	US-201313763514-A
Country	US
Kind code	B2
Filing date	Feb 8, 2013
Priority date	Feb 8, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A system and method for measuring fuel pressure decreases in a fuel accumulator caused by a fuel injector of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

First claim

We claim:

1. A system for determining a fuel quantity delivered to a plurality of combustion chambers by a fuel system of an internal combustion engine, the system comprising:
a fuel accumulator positioned to receive a fuel flow at an operating fuel pressure;
a sensor adapted to detect the operating pressure in the fuel accumulator and to transmit a pressure signal indicative of the operating fuel pressure in the fuel accumulator;
a plurality of fuel injectors, each fuel injector operable to deliver a quantity of fuel from the fuel accumulator to one of the plurality of combustion chambers; and
a control system adapted to receive the pressure signal during at least one load condition of the engine, to transmit a control signal to stop the fuel flow to the fuel accumulator during the at least one load condition, to analyze the pressure signal to determine the quantity of fuel delivered by one or more of the plurality of fuel injectors during the at least one load condition, to transmit a control signal to restart the fuel flow to the fuel accumulator after the fuel pressure in the fuel accumulator has decreased by a predetermined amount during the at least one load condition, to adjust an operating parameter of at least one of the plurality of fuel injectors based on the analysis of the pressure signal, to monitor convergence of the at least one fuel injector, and to increase a length of time between transmissions of the control signal to stop the fuel flow to the at least one fuel injector based on the convergence of the fuel accumulator.

2. The system of claim 1 , further including an inlet metering valve, the inlet metering valve adapted to receive the control signal from the control system to stop the fuel flow to the accumulator.

3. The system of claim 1 , wherein the control system adjusts an operating parameter of at least one of the plurality of fuel injectors based on the analysis of the pressure signal.

4. The system of claim 1 , the internal combustion engine including a crankshaft and wherein the fuel flow is stopped at a predetermined crankshaft angle.

5. The system of claim 4 , wherein the fuel flow is stopped at a non-zero crankshaft angle.

6. The system of claim 1 , wherein the fuel flow is stopped at a predetermined interval.

7. The system of claim 6 , wherein the predetermined interval is one hour after a timer is initiated.

8. The system of claim 7 , wherein the pressure signal is received and analyzed by the control system over a plurality of predetermined intervals and the quantity of fuel delivered is averaged over the plurality of predetermined intervals.

9. The system of claim 1 , wherein the fuel flow is stopped only if the operating fuel pressure in the fuel accumulator is above a minimum fuel pressure level.

10. The system of claim 1 , wherein the operating fuel pressure decrease is measured from a current operating fuel pressure in the fuel accumulator.

11. A method of determining an amount of fuel injected by a fuel injector of an internal combustion engine, the method comprising:
providing a fuel flow to a fuel accumulator at an operating fuel pressure;
stopping, during at least one load condition of the engine, the fuel flow to the fuel accumulator to define a beginning of a termination event;
determining, during the at least one load condition, the operating fuel pressure in the fuel accumulator during the termination event;
restarting, during the at least one load condition, the fuel flow to the fuel accumulator when the operating fuel pressure in the fuel accumulator decreases by a predetermined amount, defining an end of the termination event;
determining, during the at least one load condition, the amount of fuel delivered by the fuel injector during a fuel injection event from the operating fuel pressure;
adjusting an operating parameter of at least one of the plurality of fuel injectors based on the analysis of the pressure signal;
monitoring convergence of the at least one fuel injector; and
increasing a length of time between transmissions of the control signal to stop the fuel flow to the fuel accumulator based on the convergence of the at least one fuel injector.

12. The method of claim 11 , wherein an operating parameter of the fuel injector is modified to change the amount of fuel delivered by the fuel injector during a subsequent fuel injection event.

13. The method of claim 11 , wherein the fuel flow is stopped at a predetermined interval.

14. The method of claim 11 , wherein the amount of fuel delivered is averaged over a plurality of termination events.

15. The method of claim 11 , wherein the fuel flow is stopped only if the fuel pressure in the fuel accumulator is above a minimum fuel pressure level.

16. The method of claim 11 , wherein the operating fuel pressure decrease is measured from a current operating fuel pressure in the fuel accumulator.

17. The method of claim 11 , the internal combustion engine including a control system and wherein the control system adjusts an operating parameter of the fuel injector to modify the amount of fuel delivered by the fuel injector during a subsequent fuel injection event.

18. The method of claim 11 , wherein the internal combustion engine includes a control system and an inlet metering valve positioned to control the fuel flow to the fuel accumulator and the fuel flow is stopped by sending a control signal from the control system to the inlet metering valve.

19. The method of claim 11 , wherein the internal combustion engine further includes a crankshaft and wherein the fuel flow is stopped at a predetermined crankshaft angle.

20. The method of claim 19 , wherein the fuel flow is stopped at a non-zero crankshaft angle.

21. The system of claim 1 , wherein the control system is further adapted to stop the fuel flow to the fuel accumulator when the operating fuel pressure is a minimum operating fuel pressure.

Assignees

• Cummins Inc

Inventors

• Carey David M
• Moonjelly Paul V

Classifications

• F02M65/001

  Measuring fuel delivery of a fuel injector · CPC title

• F02D41/221

  relating to the failure of actuators or electrically driven elements · CPC title

• F02D41/3845 Primary

  by controlling the flow into the common rail, e.g. the amount of fuel pumped · CPC title

• F02D2200/0602

  Fuel pressure · CPC title

• F02D2200/0616

  determined by estimation · CPC title