| 摘要 |
PROBLEM TO BE SOLVED: To easily and accurately sense a positionof a valve which is driven by a DC motor by driving a valve by means of a DC motor through a transmission member installed on a rotary shaft of the DC motor, and arranging a control part of the DC motor and a position sensor of the valve using ripple waves of the DC motor. SOLUTION: Torque of a DC motor 10 rotates a shaft 62 by means of a worm gear (transmission member) 66, and transmitted to a shaft 58. In an intake valve 50, a shaft 58 is moved upward, separated from a valve seat 56 for communicating an intake passage 52 with an intake passage 54. When the shaft 58 is moved downward, and communication between the passages 52, 54 is interrupted. A control mechanism 12 is provided for rotationally driving the DC motor 10 which counts ripple waves output from a ripple terminal until inertial rotation is stopped. When the inertial rotation of the DC motor 10 is stopped, error between a desirable position of the intake valve 50 and the position where the intake valve 50 actually stops is computed from the counted number of the ripple waves. |
