Method for determining a remaining life of engine oil

• US 5,750,887 A
• Filed: 11/18/1996
• Issued: 05/12/1998
• Est. Priority Date: 11/18/1996
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Schricker, David R.
• Primary Examiner(s): Dombroske, George M.
• Application Number:
  US08/749,603
• Time in Patent Office: 540 Days
• Field of Search: 73/116, 73/117.2, 73/117.3, 73/118.1, 364/431.03, 364/550, 340/438, 340/439
• US Class Current: 73/114.55
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: F01M 2011/14 for indicating the necessity to change the oil
• CPC Class Codes: F01M 2011/1466 by considering quantity of soot
• CPC Class Codes: F01M 2011/148 by considering viscosity
• CPC Class Codes: F02D 2250/11 Oil dilution, i.e. prevention thereof or special controls according thereto
• CPC Class Codes: F16N 29/04 enabling a warning to be given; enabling moving parts to be stopped
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A method for determining a remaining life of engine oil in an engine is provided. The method includes the steps of measuring a plurality of engine parameters, determining an estimate of the characteristics of the engine oil as a function of the engine parameters, and trending the estimate and responsively determining the remaining life of the engine oil.

Claims

1. A method for determining the remaining life of engine oil in an engine, comprising:

measuring a plurality of engine parameters;

determining an estimate of a characteristic of the engine oil as a function of said plurality of engine parameters; and

,

trending said estimate and responsively determining the remaining life of the engine oil.

2. A method, as set forth in claim 1, wherein the remaining life of engine oil is expressed in terms of a measure of the operating life of the engine.

3. A method, as set forth in claim 1, wherein the remaining life of engine oil is expressed in terms of a percentage.

4. A method, as set forth in claim 1, wherein said trending is with respect to a measure of operation of the engine.

5. A method, as set forth in claim 4, wherein said measure of operation of the engine is operating hours of the engine.

6. A method, as set forth in claim 4, wherein said measure of operation of the engine is fuel consumption.

7. A method, as set forth in claim 4, wherein said measure of operation of the engine is cycles of said engine.

8. A method, as set forth in claim 4, wherein said step of trending includes the steps of:

curve fitting said estimate to a function;

setting said function equal to a predetermined threshold and solving for the remaining life of the engine oil in terms of said measure of operation.

9. A method for determining the remaining life of engine oil in an engine, comprising:

measuring a plurality of engine parameters;

determining an estimate of a first characteristic of the engine oil as a function of said plurality of engine parameters;

calculating a first estimate of the remaining life of the engine oil in response to trending said estimate of said first characteristic;

determining an estimate of a second characteristic of the engine oil as a function of said plurality of engine parameters;

calculating a second estimate of the remaining life of the engine oil in response to trending said estimate of said second characteristic; and

,

comparing said first and second estimate of the remaining life and responsively determining the remaining life of the engine oil.

10. A method, as set forth in claim 9, wherein the remaining life of engine oil is expressed in terms of a measure of the operating life of the engine.

11. A method, as set forth in claim 9, wherein the remaining life of engine oil is expressed in terms of a percentage.

12. A method, as set forth in claim 9, wherein the remaining life of the engine oil is set equal to the lessor of said first and second estimates.

13. A method for determining the remaining life of engine oil in an engine, comprising:

measuring a plurality of engine parameters;

determining soot estimate as a function of said plurality of engine parameters, said soot estimate being indicative of an amount of soot present in said engine oil;

calculating a first estimate of the remaining life of the engine oil in response to trending of said soot estimate;

determining an oxidation estimate of the engine oil as a function of said plurality of engine parameters, said oxidation estimate being indicative of an amount of oxidation of said engine oil;

calculating a second estimate of the remaining life of the engine oil in response to trending said oxidation estimate;

determining a change in viscosity estimate of the engine oil as a function of said plurality of engine parameters, said viscosity estimate being indicative of a viscosity of said engine oil;

calculating a third estimate of the remaining life of the engine in response to trending said change in viscosity estimate;

determining a total base number estimate of said engine oil as a function of said plurality of engine parameters, said total base estimate being indicative of a measure of acid neutralizing capacity of said engine oil;

calculating a fourth estimate of the remaining life of the engine in response to trending said estimate of said total base number estimate; and

,

comparing said first, second, third, and fourth estimate of the remaining life and responsively determining the remaining life of the engine oil.

14. A method, as set forth in claim 13, wherein the remaining life of engine oil is expressed in terms of a measure of the operating life of the engine.

15. A method, as set forth in claim 13, wherein the remaining life of engine oil is expressed in terms of a percentage.

16. A method, as set forth in claim 13, wherein the remaining life of the engine oil is set equal to the lessor of said first, second, third, and fourth estimates.

17. A method, as set forth in claim 13, wherein said plurality of engine parameters includes engine rpm, rack position, engine timing, a mean gas temperature and an engine fuel to air ratio.

18. A method, as set forth in claim 13, wherein said step of determining a soot estimate includes the step of:

determining a soot value as a function of said engine rpm, rack position, engine timing, a mean gas temperature and an engine fuel to air ratio;

determining a level of dispersant present in said oil; and

,

wherein said estimate of soot is a function of said soot value and said level of dispersant.

19. A method, as set forth in claim 13, wherein said plurality of engine parameters includes engine rpm, engine oil temperature at top ring groove, and temperature at sump.

20. A method, as set forth in claim 19, wherein said oxidation estimate is a function of said engine rpm, engine oil temperature at top ring groove, and temperature at sump.

21. A method, as set forth in claim 19, wherein said viscosity estimate is a function of engine rpm, engine oil temperature at top ring groove, and temperature at sump.

22. A method, as set forth in claim 19, wherein said total base number estimate is a function of engine rpm, fuel consumption rate, engine coolant temperature, and intake air temperature.

23. A method for determining the remaining life of engine oil in an engine, comprising:

measuring a plurality of parameters of the engine;

determining a soot estimate as a function of said plurality of parameters, said soot estimate being indicative of an amount of soot present in said oil;

determining a dispersant estimate, said dispersant estimate being indicative of an amount of dispersant remaining in the engine oil;

calculating a soot value as a function of said estimate of soot and said estimate of dispersant; and

calculating the remaining life of the engine oil in response to trending said soot value.

24. A method, as set forth in claim 23, wherein the remaining life of engine oil is expressed in terms of a measure of the operating life of the engine.

25. A method, as set forth in claim 23, wherein the remaining life of engine oil is expressed in terms of a percentage.

26. A method, as set forth in claim 25, wherein said trending is with respect to a measure of operation of the engine.

27. A method, as set forth in claim 26 wherein said measure of operation of the engine is operating hours of the engine.

28. A method, as set forth in claim 26, wherein said measure of operation of the engine is fuel consumption.

29. A method, as set forth in claim 26 wherein said measure of operation of the engine is cycles of said engine.

30. A method, as set forth in claim 26, wherein said step of trending includes the steps of:

curve fitting said soot value to a function;

setting said function equal to a predetermined threshold and solving for the remaining life of the engine oil in terms of said measure of operation.