VARIABLE OIL PUMP DIAGNOSTIC

• US 20130192545A1
• Filed: 01/31/2012
• Published: 08/01/2013
• Est. Priority Date: 01/31/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Bidner, David Karl, Rollinger, John Eric, Smiley, John, Badillo, Ed
• Granted Patent: US 8,739,746 B2
• Time in Patent Office: Days
• US Class Current: 123/41.15
• CPC Class Codes: F01M 1/08 Lubricating systems characterised by the provision therein of lubricant jetting means
• CPC Class Codes: F01M 1/16 Controlling lubricant pressure or quantity rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: G01M 15/09 by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts

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.

Claims

1. An engine method, comprising:

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.

2. The engine method of claim 1, wherein the relationship includes a responsive curve inflection point of the oil pressure.

3. The engine method of claim 2, wherein the inflection point indicates the oil pressure at which a check valve upstream of the piston-cooling jet opens.

4. The engine method of claim 1, wherein the relationship is determined during select operating conditions.

5. The engine method of claim 4, wherein the select operating conditions include a change in variable camshaft timing of less than a threshold.

6. The engine method of claim 4, wherein the select operating conditions include unregulated oil pressure.

7. The engine method of claim 1, wherein indicating degradation of the piston-cooling jet system further comprises setting a diagnostic code for the piston-cooling jet degradation and notifying a vehicle operator.

8. The engine method of claim 1, further comprising, in response to the indication of degradation, lowering maximum available engine torque.

9. The engine method of claim 1, further comprising, in response to the indication of degradation, lowering an engine coolant temperature set point.

10. An engine method, comprising:

during select conditions, reducing engine oil output from a variable flow oil pump if an inflection point between engine speed and oil pressure at maximum oil pump displacement 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.

11. The engine method of claim 10, wherein the select conditions comprise engine temperature being above a threshold.

12. The engine method of claim 10, wherein the select conditions comprise engine speed and load exceeding a threshold.

13. The engine method of claim 10, further comprising, if the inflection point is above the second threshold and, during the select conditions the engine oil output is at maximum output, lowering maximum available engine torque and/or lowering a coolant temperature set point.

14. An engine system, comprising:

a variable flow oil pump;

a piston cooling jet system including a preloaded spring check valve; and

a controller including instructions to;

indicate degradation of the piston-cooling jet system in response to a change in an inflection point between engine speed and oil pressure at maximum oil pump displacement; and

lower one or more of a maximum available engine torque and engine coolant temperature set point in response to the indicated degradation.

15. The engine system of claim 14, wherein the change in inflection point is determined during stable variable camshaft timing conditions.

16. The engine system of claim 14, wherein the change in inflection point is determined during unregulated oil pressure operating conditions.

17. The engine system of claim 14, wherein the change in inflection point is determined during conditions where oil temperature is in a threshold range.

18. The engine system of claim 14, wherein a decrease in the inflection point indicates a decrease in a set point of the check valve, and in response to the decrease in the set point, decreasing oil pump output when engine temperature exceeds a threshold.

19. The engine system of claim 14, wherein an increase in the inflection point indicates an increase in a set point of the check valve, and in response to the increase in the set point, increasing oil pump output when engine temperature exceeds a threshold.

20. The engine system of claim 14, wherein the controller includes further instructions to, if a determined oil pressure at a given engine speed is lower than an expected oil pressure, indicate degradation of the variable flow oil pump.