| 摘要 |
PROBLEM TO BE SOLVED: To hold a convergent state stably after real valve timing (real timing angle valve) has converged to target valve timing (target timing angle value). SOLUTION: At a point t2 of time when determined the real timing angle is determined to be converged to the target timing angle value, F/B control is changed to a slow change control. In the slow change control, a drive current value is slowly changed by averaging the drive current value to approach a holding current value slowly until the deviation between the drive current value and the holding current value of a hydraulic control valve is fully minimized. At a point t3 of time when the deviation between the drive current value and the holding current value is fully minimized, the slow change control is changed to holding control to hold the real timing angle value to the holding current value by changing the drive current value to the holding current value. This process makes it possible to prevent the drive current value from momentarily and greatly changing when the drive current value is changed to the holding current value to enable the real timing angle to be prevented from deviating from the target timing angle after changing to the holding current value. COPYRIGHT: (C)2004,JPO
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