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US 8,739,746 B2Granted
Variable oil pump diagnostic
AssigneeFord Global Technologies, LLC
InventorsDavid Karl Bidner, John Eric Rollinger, John Smiley, Ed Badillo
Life of this patent
Estimating the term…
Abstract
Embodiments for indicating degradation of a piston-cooling jet system are provided. In one example, an engine method comprises indicating degradation of a piston-cooling jet system in response to a relationship between engine speed and oil pressure at maximum oil pump displacement conditions. In this way, engine operation may be adjusted in response to an indicated degradation.
Claims17
An engine method, comprising:
- during a first condition, pumping engine oil at less-than-maximum oil pump displacement to one or more components of an engine;
- during a second condition including unregulated oil pressure where the oil pressure does not undergo a commanded change in oil pressure, pumping engine oil at maximum oil pump displacement to the one or more components of the engine;
- and
- indicating degradation of a piston-cooling jet system during the second condition in response to a relationship between engine speed and oil pressure at the maximum oil pump displacement, wherein the relationship includes a responsive curve inflection point of the oil pressure, and wherein the response curve inflection point is determined responsive to the engine oil being pumped at maximum oil pump displacement.
1 more element
An engine method, comprising:
- during a first condition, pumping engine oil at less-than-maximum oil pump displacement from a variable flow oil pump to one or more components of an engine;
- during a second condition, pumping engine oil at maximum oil pump displacement from the variable flow oil pump to the one or more components of the engine and determining an inflection point between engine speed and oil pressure representing an oil pressure at which a passive check valve of a piston-cooling jet system opens, the inflection point determined by collecting multiple engine speed/oil pressure points across a range of engine speeds from low engine speed to high engine speed;
- reducing engine oil output from the variable flow oil pump if the inflection point is below a first threshold, and
- increasing engine oil output from the variable flow oil pump if the inflection point is above a second threshold.
1 more element
An engine system, comprising:
- a variable flow oil pump;
- a piston cooling jet system including a passive preloaded spring check valve;
- and
- a controller including instructions to:
- when operating at less-than-maximum oil pump displacement, maintain desired oil pressure by feedback control of the oil pump;
- indicate degradation of the passive preloaded spring check valve in response to a change in an inflection point between engine speed and oil pressure at maximum oil pump displacement comprising unregulated oil pressure where the oil pressure does not undergo a commanded change, the inflection point determined by collecting multiple engine speed/oil pressure points across a range of engine speeds from low engine speed to high engine speed;
- and
- lower one or more of a maximum available engine torque and an engine coolant temperature set point in response to the indicated degradation.
5 more elements
Dependencies are inferred from the claim text.