| 摘要 |
PROBLEM TO BE SOLVED: To reduce operating noise while surely changing a camshaft phase, when the camshaft phase (valve timing) is changed during engine stop by an electric variable valve timing device. SOLUTION: For changing the camshaft phase during the engine stop, firstly, a current application increase control in which a current application duty ratio of a motor is set to be a predetermined increase value (a current application duty ratio outputting torque necessary for changing the camshaft phase during the engine stop), is executed, when the current application of the motor of the variable valve timing device 18 is started. Thereby, the output torque of the motor is appropriately increased to surely change the camshaft phase. A phase change speed feedback control in which the current application duty ratio is feedback controlled to match the actual change speed of the camshaft phase with a target change speed after the execution of current application increase control, is executed. Thereby, excessive increase in change rate of the camshaft phase is prevented to reduce the operating noise of the variable valve timing device 18. COPYRIGHT: (C)2011,JPO&INPIT |
