| 摘要 |
<p>PURPOSE:To enhance drivability by skippingly controlling an opening/closing control valve for controlling an actuator for opening or closing a waste gate valve if a difference between a target supercharging pressure and an actual supercharging pressure is smaller than a determined value. CONSTITUTION:In a turbocharger 1, a waste gate valve 7 is provided on a bypass passage 6 disposed with respect to an exhaust turbine 2, and is opened or closed by an actuator 8. The actuator 8 opens the waste gate valve 7 via an operating rod 8c in the case where an air pressure inside a diaphragm chamber 8b regulated by an opening/closing control valve 11 exceeds a predetermined value specified by a pressure regulating spring. In duty-controlling the opening/ closing control valve VSV11 by means of an ECU 12, a duty ratio is skippingly changed up to a value determined on the basis of a supercharging pressure if a difference between a target supercharging pressure and an actual supercharging pressure is smaller than the determined value, and then, the duty ratio is gradually changed.</p> |
