| 摘要 |
PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine capable of suppressing generation of a hammering sound in the internal combustion engine executing oil jet to cool a piston and the like.SOLUTION: In a warming-up operation of an engine, piston jet is stopped when an engine load is lower than a prescribed value, a cooling water temperature is higher than an engine oil temperature, and the difference therebetween is a prescribed value or more. Thus an enlargement of an outer diameter of the piston follows an enlargement of a cylinder bore diameter, increase of a clearance gap between an inner face of a cylinder bore and an outer face of the piston is suppressed, and the generation of a hammering sound can be suppressed. The piston jet is started when the engine load becomes higher than the prescribed value, and the difference between the cooling water temperature and the engine oil temperature becomes less than the prescribed value. |
