| 摘要 |
PURPOSE:To provide sufficient responsilility upon controlling the amount of sucked air by a method wherein two throttle velves that are driven by step motors are arranged in parallel, and the step motors are driven at low pulse rates. CONSTITUTION:The first and second throttle valves 10, 20 are driven by the first and second step motors 30, 40. The quantity of suction air through a subsuction passage 2 is 1/20 of the quantity of suction air through a main suction passage 1. Both the step motors are controlled by a control circuit 50, and an accelrator opening detector 70. The rotational angle of the first step motor 30 per step is 1.8 deg. while the rotational angle of the second step motor 40per step is 3.6 deg.. According to the instant invention, quick responsibility and high accuracy of the control of amount of suction air can be attained without increasing the driving pulse rats of the step motors. |
