Methods for detecting high pressure pump bore wear
AssigneeFord Global Technologies, LLC
InventorsJoseph Norman Ulrey, Ross Dykstra Pursifull, Mark Meinhart, Gopichandra Surnilla
Life of this patent
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Abstract
Methods are provided for detecting high pressure pump bore wear, wherein wear between a piston and bore of a pump may cause an excessive amount of fuel to leak out of a compression chamber of the pump. A reliable method is needed that involves a pump performance model that incorporates a number of physical effects and is verified by real high pressure pump test data. A method is proposed that involves comparing a target pump rate based on the pump performance model to a real fuel injection rate in order to determine if an abnormal amount of fuel may be leaking from the high pressure pump.
Claims20
A method, comprising:
- while an engine is at an idling speed:
- increasing pressure in a direct injection fuel rail of the engine to a threshold fuel rail pressure;
- computing a target pump rate of a high pressure fuel pump based on a pump performance model;
- computing a fuel injection rate;
- comparing the target pump rate and the fuel injection rate;
- and
- issuing a piston-bore interface leak result based on the comparison.
A method, comprising:
- upon completion of an initiation condition and while an engine is at an idling speed:
- increasing pressure in a direct injection fuel rail of the engine to a threshold fuel rail pressure;
- computing a target pump rate of a high pressure fuel pump based on a pump performance model;
- computing a fuel injection rate;
- comparing the target pump rate and the fuel injection rate;
- and
- diagnosing a piston-bore interface as abnormally leaking if the target pump rate is higher than the fuel injection rate by more than a margin.
A fuel system, comprising:
- one or more direct fuel injectors configured to inject fuel into one or more cylinders of an engine;
- a fuel rail fluidly coupled to the one or more direct fuel injectors;
- a high pressure fuel pump fluidly coupled to the fuel rail;
- and
- a controller with computer readable instructions stored in non-transitory memory for:
- while an engine is at an idling speed, increasing pressure in the fuel rail, computing a target pump rate of the high pressure fuel pump based on a pump performance model, computing a fuel injection rate, comparing the target pump rate and the fuel injection rate, and issuing a piston-bore interface leak result based on the comparison.
Dependencies are inferred from the claim text.