| 摘要 |
PURPOSE:To maintain high supercharging efficiency over an wide range of running state by a method wherein the number of superchargers (turbochargers) in use is gradually increased with the increase of the flow rate of exhaust gas. CONSTITUTION:When an engine 1 is operated in the light load and low rotational frequency range, only a first supercharger 10 is in operation and supercompressed suction air is supplied through a main suction pipe 5 to the engine 1. Next, when supercharged air pressure exceeds the set pressure of a first actuator 18, a first control valve 16 is open, resulting in driving a second supercharger 20 by exhaust gas X2. After that, when the pressure of supercompressed charging air produced by the second supercharger 20 exceeds the supercharged air pressure produced by the first supercharger 10, a first check valve 50 is open, resulting in supplying suction airs Y1 and Y2 to the engine 1. When the supercharged air pressure produced by the second supercharger 20 exceeds the set pressure of a second actuator 28, a second control valve 26 is open resulting in actuating a third supercharger 30 in the similar manner as mentioned above. |
