| 摘要 |
<p>PURPOSE:To extend the life of a battery and improve startability of an engine by providing a current supply control means to stop electric power supply to a control valve driving circuit with which a control valve is driven to communicate or intercept between a hydraulic actuator and an oil pressure supply part. CONSTITUTION:Intake valves 1, 1' are driven with hydraulic actuators 2, 2'. A control circuit 21 controls piezo-electric actuators 9, 10 to control action of the intake valves l, 1'. An output port 25 is connected to the piezo-electric actuators 9, 10 through control valve driving circuits 35, 36. The valve timing of the intake valves 1, 1' are freely controlled by the valve timing of control valves 6, 8. During no existence of valve drive, the electric power source of the control valve driving circuits 35, 36 is OFF to decrease power source load of a battery 39. In this way, starter output is improved and startability can be improved.</p> |
