| 摘要 |
PROBLEM TO BE SOLVED: To surely change the rotating phase of a camshaft by releasing the lock by a lock mechanism in all valve timing variable devices even under insufficient fluid pressure. SOLUTION: This intake and exhaust valve timing variable devices installed in an engine comprise variable mechanisms operated by hydraulic pressure, lock mechanisms, and oil control valves (OCV). When an electronic control device (ECU) outputs instruction signals for changing a lock phase to a different rotating phase simultaneously to both OCVs (step 130), both valve timing variable devices may operate with a time difference according to the instruction signals. When the hydraulic pressure is low based on engine information on hydraulic pressure or the equivalent, the ECU limits the controlled variable (duty ratio) of the instruction signals outputted to the OCV of the valve timing variable device which starts to operate earlier (steps 110, 120, 150). COPYRIGHT: (C)2005,JPO&NCIPI
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