| 摘要 |
PURPOSE:To raise safety of a throttle valve at locking thereof and thereby improve control accuracy of a second throttle valve by providing said throttle valve interlocking with an acceleration pedal and said second throttle valve controlled by an electronic control device, in an air intake passage. CONSTITUTION:A first throttle valve 19 opened and closed by a throttle cable 13 connected to an acceleration pedal and a second throttle valve 21 driven by a step motor 25 controlled by an electronic control device are provided in an air intake passage 17 of an engine. A return spring 18 is provided on the first throttle valve 19, but it is not provided on the second throttle valve 21. Hereby, the step motor can be accurately controlled as a speed type one, while the first throttle valve can be closed even if the second throttle valve is locked at its open position, enabling safety to be improved. |
