Method for determining the condition of engine oil based on soot modeling
AssigneeCaterpillar Inc.
InventorsJagannathan Sarangapani, David R. Schricker, Trent A. Simpson
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Abstract
A method for monitoring the condition of oil in an engine is disclosed which includes the steps of determining a plurality of parameters, determining a fuel injection model, determining the area of the cylinder walls that is coated with soot, and responsively determining a soot model. The method may include the additional steps of calculating a value of residual soot, and calculating a value of soot dispersed by dispersants. The accumulation of soot determined from the model may be trended over time to predict the useful life of the oil.
Claims30
A method for determining the condition of lubricating oil in an internal combustion engine, including the steps of:
- determining a plurality of parameters associated with the engine;
- determining a model of the duration of injection of fuel into a cylinder in the engine;
- determining a wall area of the cylinder that is coated with soot during injection;
- determining a model of the soot in the oil as a function of the parameters, the fuel injection duration model, and the coated wall area;
- and
- responsively determining the condition of the oil.
A method for determining the condition of oil in an internal combustion engine, including the steps of:
- determining a plurality of parameters associated with the engine;
- determining a model of the duration of injection of fuel into a cylinder in the engine;
- determining a wall area of the cylinder that is coated with soot during injection;
- calculating a value of residual soot in the engine as a function of the engine geometry and at least one occurrence of replacing the used engine oil with new engine oil;
- calculating a value of soot dispersed by dispersants in the engine oil as a function of at least one occurrence of replacing the used engine oil with new engine oil;
- determining a model of the soot in the oil as a function of the parameters, the coated wall area, the residual soot, and the dispersed soot;
- and
- responsively determining the condition of the oil.
A model for determining the condition of oil in an internal combustion engine, comprising:
- a fuel injection duration model for determining a start of injection, an end of injection, and a duration of injection of fuel into a cylinder in the engine;
- a crank model for receiving the determined data from the fuel injection duration model, and responsively determining the area exposed to injection of fuel in an inner wall of the cylinder;
- and
- a soot model for receiving the determined data from the crank model and for receiving a plurality of parameters associated with the engine, responsively determining a value of soot in the oil, and responsively determining the condition of the oil.
Dependencies are inferred from the claim text.