| 摘要 |
A valve timing control apparatus for an engine. Presence/absence of a torque demand (xtq) is estimated upon starting of a lock pin release control to thereby alter a change rate (beta) of a target phase angle in dependence on presence/absence of the torque demand (xtq). Unless torque demand is issued, the change rate is set to a small value (beta2) for suppressing the change of the target phase angle (thetat) after detection of release of the lock pin in order to avoid a shock unexpected by a driver. When the torque demand is issued, the change rate is set to a large value (beta1) for allowing the target phase angle to approach speedily to a base target phase angle (thetamap) for thereby minimizing a delay in response involved in the phase angle detection through the lock pin release control. |
