Method and apparatus for sensing the condition of lubricating oil in an internal combustion engine
AssigneeFord Motor Company
InventorsAllen H. Meitzler, George S. Saloka
Life of this patent
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Abstract
An on-board sensor system which compares the dielectric properties of lubricating oil in an internal combustion engine with the dielectric properties of unused oil in a contained volume and providing an output signal indicative of the changes in viscosity correlated to the dielectric constant changes of the lubricating oil.
Claims10
A system for sensing the condition of the lubricating oil of an engine during engine operation and providing an operator indication when the oil needs to be restored to an acceptable condition, comprising:
- means exposed to the flow of oil through the lubrication system of said engine and having an electrical capacitance value that is dependent on the dielectric constant of said lubricating oil;
- means located so as to be isolated from said flow of lubricating oil but located proximate to said exposed capacitance means so as to be exposed to the same thermal temperatures as said exposed capacitance means and having an electrical capacitance value that is dependent on the dielectric constant of a reference medium that includes a quantity of oil in a predetermined reference volume;
- means connected to said exposed capacitance means and said isolated capacitance means for comparing the respective electrical capacitance values and providing an output signal corresponding to the difference between said capacitance values.
A method for sensing the condition of the lubricating oil of an engine during engine operation and providing an operator indication when the oil needs to be restored to an acceptable condition, comprising the steps of:
- exposing a means, having an electrical capacitance value that is dependent on the dielectric constant of said lubricating oil, to the flow of oil through the lubrication system of said engine;
- isolating a means, having an electrical capacitance value that is dependent on the dielectric constant of a reference medium that comprises a quantity of oil in a reference volume, from said flow of lubricating oil;
- and
- placing said exposed and isolated means in a common thermal environment;
- and
- comparing the respective electrical capacitance values of said exposed and isolated means and providing an operator indication when said capacitance values differ by more than a predetermined amount.
Dependencies are inferred from the claim text.