| 摘要 |
PURPOSE:To enable ensurance of a given intake air amount, by a method wherein a plurality of springs having respective given energizing forces are provided on a step motor to control an intake air amount, and during accident, e.g. disconnection, the rotor of a step motor is returned to a given position. CONSTITUTION:Rotational movement of a rotor 51 of a step motor 5 is converted into linear movement by means of a lead screw 56, the conversion regulates a gap between a valve 6 and a valve seat positioned facing the valve, and an air flow rate is controlled. In this case, along with rotation of the rotor 51, a gear 59 engaged with a pinion 58 and an inner gear 60, with which a reduction mechanism is formed, is revolved as it is rotated, and a reduced power is outputted to an arm 61. Along with leftward or rightward rotation of the rotor 51, springs 63 and 64 are selectively compressed through an arm 61 and a holder 62. When energization to stator coil 52-55 is shut off, the rotor 51 is returned to a given position through the forces of the springs 63 and 64. |
