| 摘要 |
PURPOSE:To simplify a circuit structure and the control logic by using both spring force to act in the valve closing direction and thrust force in the coil closing direction when necessity to full close a flow control valve is generated. CONSTITUTION:One side of a valve shaft 36 is connected to an output shaft 21 by a shaft joint 30, and the other side penetrates a motor holder 34 provided with a gas seal 33 and a space 35 through which air is allowed to pass, and it is connected to a valve 1 capable of opening/closing a valve seat 2, and force acts in the valve closing direction by springs 31a, 31b. A magnet 17 is induction-rotated, and a rotor 19 is rotated by exciting an electric pulse signal to coils 12a, l2b. This rotation converted into the linear motion of the output shaft 21 by an external thread 22 and an internal thread 16, and becomes the linear motion of the valve shaft 36 through the shaft joint 30, and then converted into the linear motion of the valve 1 fixed to the valve shaft 36, thereby the flow rate of exhaust gas to pass a circulating passage 6 is controlled by a space of the valve 1 and the valve seat 2. |
