| 摘要 |
PROBLEM TO BE SOLVED: To prevent reduction of the learning accuracy caused by deflection of a sensor mounting part in a variable valve mechanism for continuously changing a lift amount of an engine valve by rotating/driving a control shaft when learning the sensor output corresponding to a stopper position for determining a minimum lift position. SOLUTION: When an engine is stopped, the control shaft is pressed to a stopper on a minimum lift side by changing a target in a feedback control of a rotation angle of the control shaft to the stopper direction. Here, limiting an operating amount of a motor for rotating/driving the control shaft to a predetermined value prevents a pressing torque from becoming excess. When rotation of the engine is stopped, the operating amount of the motor is made to be zero for intercepting power supply, which weakens the pressing torque to the stopper and reduces the deflection of the sensor mounting part. After that, when the sensor output for detecting the rotation angle of the control shaft is stabilized, the sensor output at that time is learned as the value corresponding to the minimum lift position. COPYRIGHT: (C)2008,JPO&INPIT
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