Diluted oil regeneration in internal combustion engine

Abstract

An internal combustion engine (10) for a vehicle comprises a fuel injector (12) which supplies fuel to a combustion chamber formed in a piston (1), and an oil pan which stores engine oil below the piston (1). With regard to a phenomenon whereby the engine oil is diluted with the fuel injected by the fuel injector (12), a controller (90) determines whether or not the engine oil needs to be regenerated (S13). When the engine oil needs to be regenerated, the controller (90) switches a cooling water path in the engine (10) by controlling an electrically controlled thermostat (74), and raises the temperature of the engine oil over a predetermined time period (S15, S17). As a result of this temperature increase, the fuel in the engine oil is vaporized, thereby reducing the dilution ratio of the engine oil, and thus the engine oil is regenerated.

Dependencies are inferred from the claim text.