VALVE TIMING CONTROL FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a valve timing control for controlling the rotational phase of a valve driving cam shaft relative to that of a crankshaft, wherein though holded data for maintaining the true rotational phase of the cam shaft in a state converged to an objective rotational phase deviates from a true value, the true rotational phase can be converged to the objective phase soon. SOLUTION: A valve timing control is provided with a variable valve timing mechanism (VVT) 25 being operated in response to the condition of a linear solenoid valve(LSV) 25, a cam sensor 78, and an electronic control unit(ECU) 80. The ECU 80 prescribes an objective rotational phase according to the operational condition of the engine 1, while the electrically energized time of LSV 55 is controlled with duty ratio based on holding duty value as data, deviation, difference in the deviation. The ECU 80 renews holded duty value when the deviation is larger than the first prescribed value and difference is not more than the second one.