| 摘要 |
PROBLEM TO BE SOLVED: To prevent the temperature of the coil of a motor from being overheated beyond an allowable temperature range in an internal combustion engine in which a valve timing is varied by using the motor as the drive source. SOLUTION: An ECU 30 estimates a motor current (drive current for a motor 26) according to a target motor rotational speed, an actual motor rotational speed, and an engine rotational speed. When the estimated motor current exceeds a set value corresponding to a heating limit current value, the varied amount of the target motor rotational speed (corrected amount of rotational speed F/B) output from the ECU 30 to an EDU 31 is limited to limit the motor current controlled for duty by the EDU 31. Since the motor current can be so limited that the heating amount of the motor 26 does not exceed a heating limit, the coil of the motor 26 can be prevented from being overheated beyond the allowable temperature range, and the degradation of the durability and the trouble of the motor 26 due to overheating can be prevented from occurring. COPYRIGHT: (C)2008,JPO&INPIT
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