| 摘要 |
PROBLEM TO BE SOLVED: To provide the electromagnetic type variable valve timing device which advances a cam phase to a crank shaft through friction breaking force by an electromagnetic break against spring force energized to a lag side, wherein a hitting sound in returning to the stopper position is reduced. SOLUTION: When a target rotation phase required according to the engine load and rotation speed is changed to the reference position (rotation phase = 0), the control target value is varied in a stepped form until the specified value S/L, but thereafter the control target value is gradually changed to the normal position with a uniform speed. By so doing, kinetic energy at the time when stopper hits, becomes small so as to reduce a hitting sound.
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