| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve gear in which generation of engine vibration in an early cranking stage of an engine can be suppressed, as well as good combustion during cranking can be obtained. SOLUTION: If it is determined to be a cooled-down state in step 3, the throttle valve SV is controlled to a large opening degree. In step 5, a large working angle and most retard angle state of air intake valves 4, 4 detected in step 1 is controlled to continue as it is. Thereby effective compression rate is reduced. As a result, vibration of the early cranking stage can be effectively reduced, and occurrence of uncomfortable feel to passengers can be suppressed. In step 6, switching control of the working angle of the air intake valves 4, 4 to an intermediate working angle D2 is performed by an air intake VEL1 after initiation of cranking, so as to reduce the working angle, thus causing a closing timing (IVC) of the air intake valves 4, 4 to advance toward a piston bottom dead-center direction. Thereby, the effective compression rate is raised, and good startabilty can be obtained even when the engine is cooled-down. COPYRIGHT: (C)2010,JPO&INPIT
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