| 摘要 |
PURPOSE:To simplify constitution of a preliminary rotating means and its control by specifying a preliminary rotating mode at the time of changing from a single turbo mode over to a twin turbo mode, closing a supercharging pressure relief valve at the mode and controlling an exhaust control valve and an air intake control valve so that they open in sequence. CONSTITUTION:Immediately after banks 3, 4 on the left and the right of a horizontal opposed type engine 1, a primary turbo supercharger 40 and a secondary turbo supercharger 50 are arranged. In a single turbo control routine, a supercharging pressure relief valve is opened, while an air intake control valve 58 and an exhaust control valve 55 are sequentially closed, and thereafter, a waste gate valve 51 is totally closed by making the duty ratio of a duty solenoid valve 53 on the secondary side 100%. At the time of transfer to a twin turbo control routine, firstly the supercharging pressure relief valve 60 is closed, thereafter, preliminary rotation control is carried out by sequentially opening the exhaust control valve 55 and the air intake control valve 58, and delay times T1-T3 to open and close each of the valves 60, 55, 58 are set in the relation of T1<T2<T3. |
