Oil supply device of internal combustion engine

An oil supply device for an internal combustion engine, the device comprising:

• a hydraulically-actuated variable valve mechanism provided for the internal combustion engine and configured to open and close a valve by hydraulically transmitting a power of a cam, rotating in accordance with an output of the internal combustion engine, to the valve;
• an electric oil pump operating with power supplied from a storage battery and configured to supply oil to the hydraulically-actuated variable valve mechanism;
• a variable valve mechanism oil supply passage configured to supply the oil discharged from the electric oil pump to the hydraulically-actuated variable valve mechanism;
• an oil reservoir arranged halfway along the variable valve mechanism oil supply passage and upstream of the cam, the oil reservoir being configured to reserve the oil discharged from the electric oil pump and to supply the reserved oil to the hydraulically-actuated variable valve mechanism while the internal combustion engine is OFF;
• a controller configured to control activation of the electric oil pump;
• and
• a reserve oil level estimator configured to estimate the level of the oil reserved in the oil reservoir;
• or
• a reserve oil level detector configured to detect the level of the oil reserved in the oil reservoir, wherein
• when the reserve oil level estimator estimates, or the reserve oil level detector detects, that the level of the oil reserved in the oil reservoir has become equal to or less than a predetermined reserve oil level while the internal combustion engine is OFF, the controller performs an oil replenishment control to replenish the oil reservoir with the oil by activating the electric oil pump.