PROBLEM TO BE SOLVED: To detect deterioration of engine oil with high accuracy and to prevent a device from getting large in size.;SOLUTION: An engine oil deterioration detection device detects a rate of decrease in an engine oil temperature after an internal combustion engine stops using a fact that deteriorated engine oil has low specific heat (a large rate of decrease in an oil temperature). Thus, the engine oil deterioration detection device can detect deterioration of the engine oil with high accuracy even when the same has a certain degree of fluidity. Also, by detecting the rate of decrease in the engine oil temperature after the internal combustion engine stops, the engine oil deterioration detection device can reduce influence of a factor (hereinafter called "disturbance factor" such as a rotation speed of an engine) other than engine oil deterioration (the specific heat) on the rate of decrease in the engine oil temperature.;COPYRIGHT: (C)2015,JPO&INPIT
展开▼
