| 摘要 |
PURPOSE:To prevent air from contraflow to a compressor section of a turbo supercharger having low supercharging pressure in low speed stage, by providing a check valve in an outlet portion or air supply pipe of the compressor section in the turbo supercharger having low supercharging pressure in the low speed stage, compared with other supercharger. CONSTITUTION:An exhaust bypass valve 44 and an exhaust intake valve 46 are closed in low speed stage and only a low speed turbo supercharger 32A having large low speed torque is driven. In medium and high speed stages, said valves 44, 46 are opened, and a high speed turbo supercharger 32B having large high speed torque is driven. A lead valve 43 disposed in a first air supply pipe 39B is closed against air flow forcibly sent by the low speed turbo supercharger 32A having large supercharging pressure in low speed stage to prevent a compressor section 34B of the high speed turbo supercharger 32A from the occurrence of surge phenomenon. |
