| 摘要 |
PROBLEM TO BE SOLVED: To achieve displacement at favorable responsiveness to the most advanced timing side, and save power consumption in holding on the most advanced turning side in a variable valve timing mechanism to change a valve timing by changing a rotation phase of a cam shaft. SOLUTION: An energization quantity of a linear solenoid valve to control oil pressure is duty-controlled to control a rotation phase. For a target value TA of the rotation phase in accordance with operation conditions (S1), when it is changed to the most advanced turning side as a stopper position (S2), a time Y to output 100% on-duty is determined based on a deviationΔTA of the target value, an oil temperature, and a power voltage (S4-S9), and within the time Y after the target value is changed to the most advanced timing side (S10), the 100% on-duty is outputted to the linear solenoid valve (S11). After passage of the time Y, duty X to hold the most advanced timing side is determined in accordance with the power voltage at the time (S12), the 100% on-duty is reduced to the duty X determined (S13), and a condition on the most advanced timing side is held in this condition.
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