| 摘要 |
PURPOSE:To improve the starting performance of an engine by closing a valve element by a stepper motor when an internal combustion engine is suspended/ started, and thereby initializing a relation between the number of the step of a stepper motor and the position of the valve element at the time of starting the engine. CONSTITUTION:The movement in the axial direction of a valve drive rod 40 which is reciprocated in the axial direction by a stepper motor 30, is transmitted to a valve shaft 18 via a compression type elastic member 48. For example, in the entirely closed condition of an exhaust gas re-circulating control valve, a valve element 16 provided for a valve shaft 18 is pressed onto a valve seat 14 owing to the compressed elastic deformation of a compression type elastic member 48 so that valve shut-off force is thereby obtained. In this case, when an internal combustion engine is suspended/started, the valve element 16 is entirely closed by the stepper motor 30 respectively. When the valve element 16 is entirely closed at the time of starting the internal combustion engine, a relation between the number of the step of the stepper motor 30 and position of the valve element 16 is thereby initialized. |
