Apparatus and method for diagnosing lubricant degradation in internal combustion engine
First Claim
1. A method for diagnosing degradation of a lubricant in an internal combustion engine, the method comprising:
- detecting a speed of the engine by a first sensor positioned to measure the speed of the engine and to output a speed detection signal;
determining a load of the engine by a second sensor configured to detect a load parameter related to torque generated by the engine and configured to output a load detection signal;
detecting a temperature parameter of the engine with a temperature sensor positioned on the engine, the temperature parameter being proportional to the temperature of a combustion chamber;
estimating an amount of soot, formed in a predetermined period in the combustion chamber of the internal combustion engine, based on the detected speed of the internal combustion engine and the determined load related to torque generated by the internal combustion engine;
calculating a cumulative value of the amount of soot estimated; and
determining degradation of the lubricant in the internal combustion engine based on the cumulative value of the amount of soot;
estimating the temperature of the combustion chamber based on the detected temperature, and correcting the amount of soot estimated into an increased value in response to when the estimated temperature of the combustion chamber is lower than a predetermined first temperature at which fuel injected into the combustion chamber vaporizes less with a decrease in temperature when estimating the amount of soot formed in the combustion chamber; and
actuating an indicator when the corrected amount of estimated soot reaches a predetermined amount.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus for diagnosing lubricant degradation includes a soot amount estimator configured to estimate an amount of soot formed in a predetermined period in a combustion chamber of an engine, and diagnoses the degradation of a lubricant based on a cumulative value of the amount of soot estimated. The soot amount estimator calculates the amount of soot based on a speed of the engine and a load parameter related to a load of the engine, and corrects, based on a temperature parameter correlated to the temperature of the combustion chamber, the amount of soot calculated into an increased value if the temperature parameter is lower than a predetermined first temperature.
12 Citations
11 Claims
-
1. A method for diagnosing degradation of a lubricant in an internal combustion engine, the method comprising:
-
detecting a speed of the engine by a first sensor positioned to measure the speed of the engine and to output a speed detection signal; determining a load of the engine by a second sensor configured to detect a load parameter related to torque generated by the engine and configured to output a load detection signal; detecting a temperature parameter of the engine with a temperature sensor positioned on the engine, the temperature parameter being proportional to the temperature of a combustion chamber; estimating an amount of soot, formed in a predetermined period in the combustion chamber of the internal combustion engine, based on the detected speed of the internal combustion engine and the determined load related to torque generated by the internal combustion engine; calculating a cumulative value of the amount of soot estimated; and determining degradation of the lubricant in the internal combustion engine based on the cumulative value of the amount of soot; estimating the temperature of the combustion chamber based on the detected temperature, and correcting the amount of soot estimated into an increased value in response to when the estimated temperature of the combustion chamber is lower than a predetermined first temperature at which fuel injected into the combustion chamber vaporizes less with a decrease in temperature when estimating the amount of soot formed in the combustion chamber; and actuating an indicator when the corrected amount of estimated soot reaches a predetermined amount. - View Dependent Claims (2, 3, 4, 5)
-
-
6. An apparatus for diagnosing degradation of a lubricant in an internal combustion engine, the apparatus comprising:
-
a first sensor positioned to detect a speed of the internal combustion engine and to output a detection signal; a second sensor configured to detect a load related to torque generated by the internal combustion engine and to output a detection signal; a third sensor positioned to detect a temperature parameter being proportional to a temperature of a combustion chamber and to output a detection signal; a soot amount estimator configured to receive the detection signals from the first, second, and third sensors, and to calculate an amount of soot formed in a predetermined period in the combustion chamber of the internal combustion engine based on the detected speed of the internal combustion engine and the load; and a diagnostic unit configured to diagnose degradation of the lubricant based on a cumulative value of the amount of soot estimated by the soot amount estimator and to actuate an indicator when the amount of estimated soot reaches a predetermined amount, wherein the soot amount estimator corrects, based on the temperature parameter, the amount of soot calculated into an increased value when estimating the temperature of the combustion chamber and determining the temperature of the combustion chamber to be lower than a predetermined first temperature, and the diagnostic unit actuates the indicator when the amount of estimated soot corrected by the soot amount estimator reaches the predetermined amount. - View Dependent Claims (7, 8, 9, 10, 11)
-
Specification