| 摘要 |
PURPOSE:To prevent generation of torque shock while improving reliability of a primary turbo supercharger and a secondary turbo supercharger regardless of engine operating condition when the engine operating condition is switched from single-turbo condition to twin-turbo condition. CONSTITUTION:Just after an engine operating range is transferred from a single turbo range to a twin turbo range across a single-to-twin switching judging boarder line, a pressure difference reduction rate DELTADPS between upstream pressure and downstream pressure of an intake air control valve is calculated (Step S40) the more the pressure difference reducing rate DELTADPS is the shorter the first setting time T2 for applying the fully opening timing of an exhaust control valve and a second setting time T3 for applying the opening timing of the intake air control valve are set. (Step S41, S42) After the first set time T2 is passed, the exhaust control valve is fully opened (Step S47), and after the second set time T3 is passed the intake air control valve is opened (Step S49). And then engine operation is switched from single turbo condition in which only a primary turbo supercharger is operated to twin turbo condition in which both turbo superchargers are operated. |
