| 摘要 |
PROBLEM TO BE SOLVED: To improve fuel consumption in an engine 1 having an oil jet 30 injecting oil directly to a piston 13, by reducing a drive load of an oil pump 5 with cooling performance for the piston 13 secured.SOLUTION: A hydraulic control device includes a target oil pressure setting part (ECU100) which sets a target oil pressure Pt at a higher value, as a piston temperature Tp estimated on the basis of an operation state of an engine 1 (load rate KL, engine revolution speed Ne, etc.) is higher. The target oil pressure setting part calculates a piston time constant τ representing a response lag of temperature change of a piston 13 for change of the operation state of an engine 1 (step ST23), and uses the piston time constant τ to correct the target oil pressure Pt (ST24). |
