| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain a motor coil from being thermally damaged and to enhance variable precision for valve timing, with compatibility therebetween. <P>SOLUTION: The motor-driven valve timing variable device sets a target rotational direction Dt of a motor shaft 102 in a direction reverse to that of an internal combustion engine, at a rotational speed Ne less than a threshold value Nth of the internal combustion engine, when satisfying the most timing-lagged condition, sets therein a duty ratio Rd to a value less than a rotation lower limit value R1, and executes most timing-lagged phase learning under the most lagged timing holding condition of holding a stopper projection 94 onto a most timing-lagged stopper 92r. The most timing-lagged phase learning under the most lagged timing holding condition is prohibited at the rotational speed Ne of the threshold value Nth or more of the internal combustion engine, when satisfying the most timing-lagged condition. The target rotational direction Dt of the motor shaft 102 is set in a normal direction same to that of the internal combustion engine, irrespective of the rotational speed Ne of the internal combustion engine, when satisfying the most timing-advanced condition, and most timing-advanced phase learning is executed under the most advanced timing holding condition of holding the stopper projection 94 onto a most timing-advanced stopper 92a. <P>COPYRIGHT: (C)2013,JPO&INPIT |
