Granted Patent B2

US 11,639,696 · App. 17/050,865 · Granted May 2, 2023

Inventors: Andreas Nilsson (London, GB); Edward Williams (London, GB)

F02D41/221F02M51/00F02D41/30F02D2041/2055F02M2200/241

Abstract

Claims (39)

1. A method of determining the nature of a fault in operation of a hydraulic fuel injector, said hydraulic fuel injector including a needle control valve which is controlled by an electrical actuator, said needle control valve configured to hydraulically control movement of a needle of a needle valve toward and away from a needle valve seat, wherein said hydraulic fuel injector includes an accelerometer located on or adjacent to said hydraulic fuel injector, said method comprising the steps of:

a) sending an actuation pulse to said electrical actuator, said actuation pulse being above a minimum drive pulse of the hydraulic fuel injector;

b) analyzing a signal from said accelerometer and determining if there is a high frequency vibration component subsequent to an end of the actuation pulse; and

c) determining functionality of the needle control valve dependent on the analyzing of step b);

wherein step c) comprises determining that there is a fault with the needle control valve if said high frequency vibration component is not detected and/or determining that there is no fault with the needle control valve if said high frequency vibration component is detected.

2. A method as claimed in claim 1 , wherein in step b) the signal is within an injection cycle of the hydraulic fuel injector.

3. A method as claimed in claim 1 , further comprising determining if there is a misfire in a respective cylinder corresponding to the hydraulic fuel injector.

4. A method as claimed in claim 1 , further comprising determining if there is a vibrational component having a low frequency component.

5. A method of determining the nature of a fault in operation of a hydraulic fuel injector, said hydraulic fuel injector including a needle control valve which is controlled by an electrical actuator, said needle control valve configured to hydraulically control movement of a needle of a needle valve toward and away from a needle valve seat, wherein said hydraulic fuel injector includes an accelerometer located on or adjacent to said hydraulic fuel injector, said method comprising the steps of:

a) sending an actuation pulse to said electrical actuator, said actuation pulse being above a minimum drive pulse of the hydraulic fuel injector;

b) analyzing a signal from said accelerometer and determining if there is a high frequency vibration component subsequent to an end of the actuation pulse;

c) determining functionality of the needle control valve dependent on the analyzing of step b); and

determining if there is a misfire in a respective cylinder corresponding to the hydraulic fuel injector;

wherein step c) comprises determining that there is a fault with the needle control valve if said high frequency vibration component is not detected and a misfire is detected.

6. A method of determining the nature of a fault in operation of a hydraulic fuel injector, said hydraulic fuel injector including a needle control valve which is controlled by an electrical actuator, said needle control valve configured to hydraulically control movement of a needle of a needle valve toward and away from a needle valve seat, wherein said hydraulic fuel injector includes an accelerometer located on or adjacent to said hydraulic fuel injector, said method comprising the steps of:

a) sending an actuation pulse to said electrical actuator, said actuation pulse being above a minimum drive pulse of the hydraulic fuel injector;

b) analyzing a signal from said accelerometer and determining if there is a high frequency vibration component subsequent to an end of the actuation pulse; and

c) determining functionality of the needle control valve dependent on the analyzing of step b);

wherein if said high frequency vibration component is detected, determining that there is a fault in the needle valve.

7. A method of determining the nature of a fault in operation of a hydraulic fuel injector, said hydraulic fuel injector including a needle control valve which is controlled by an electrical actuator, said needle control valve configured to hydraulically control movement of a needle of a needle valve toward and away from a needle valve seat, wherein said hydraulic fuel injector includes an accelerometer located on or adjacent to said hydraulic fuel injector, said method comprising the steps of:

a) sending an actuation pulse to said electrical actuator, said actuation pulse being above a minimum drive pulse of the hydraulic fuel injector;

b) analyzing a signal from said accelerometer and determining if there is a high frequency vibration component subsequent to an end of the actuation pulse; and

c) determining functionality of the needle control valve dependent on the analyzing of step b);

wherein step c) comprises determining that there is a fault with the needle valve if said high frequency vibration component is detected and a misfire is detected.

8. A method as claimed in claim 7 , further comprising determining whether there is a vibrational component having a low frequency component immediately after the end of the actuation pulse or a predetermined period thereafter.

9. A method as claimed in claim 8 , wherein said high frequency component or said low frequency component is identified by analyzing amplitude, frequency, frequency spectra, and/or duration thereof.

10. A method as claimed in claim 9 , further comprising filtering said signal to determine presence of said high frequency signal.

11. A method as claimed in claim 8 , wherein if said low frequency component is detected, concluding that the needle valve does not have a fault.

12. A method as claimed in claim 8 , wherein if said low frequency component is detected and there is a misfire, determining that one or more orifices of the needle valve is blocked.

13. A method as claimed in claim 8 , wherein if said high frequency component is detected and said low frequency component is not detected, then determining that the needle valve is stuck.

14. A method as claimed in claim 8 , wherein determining if there is a vibrational component having a low frequency component comprises: where said high frequency component is detected, determining if said vibrational component having a low frequency component is detected between the end of the actuation pulse and a start of said high frequency component.

15. A method as claimed claim 8 , wherein said high frequency component is indicative of the needle control valve working and/or said low frequency component is indicative the needle valve opening or closing.

16. A method as claimed in claim 8 , wherein said low frequency component is characterised by wave activity in a range of 17-20 kHz range or 45-50 kHz range.

17. A method as claimed in claim 8 , wherein said low frequency component is in a range of 15-50 KHz.

18. A method of determining the nature of a fault in operation of a hydraulic fuel injector, said hydraulic fuel injector including a needle control valve which is controlled by an electrical actuator, said needle control valve configured to hydraulically control movement of a needle of a needle valve toward and away from a needle valve seat, wherein said hydraulic fuel injector includes an accelerometer located on or adjacent to said hydraulic fuel injector, said method comprising the steps of:

a) sending an actuation pulse to said electrical actuator, said actuation pulse being above a minimum drive pulse of the hydraulic fuel injector;

b) analyzing a signal from said accelerometer and determining if there is a high frequency vibration component subsequent to an end of the actuation pulse; and

c) determining functionality of the needle control valve dependent on the analyzing of step b);

wherein said high frequency component is generally in a range 65-75 kHz.

Assignments (6)