| 摘要 |
PROBLEM TO BE SOLVED: To suppress leakage of a lubricant from a bearing portion of a low-speed exhaust turbosupercharger when operating a high-speed exhaust turbosupercharger included in a two-stage turbo engine to perform supercharging of intake air.SOLUTION: An internal combustion engine comprises: a low-speed exhaust turbosupercharger with a low-speed turbine and a low-speed compressor; a high-speed exhaust turbosupercharger with a high-speed turbine and a high-speed compressor; an exhaust bypass valve for opening and closing a bypass passage which bypasses the low-speed turbine; an intake bypass valve for opening and closing a bypass passage which bypasses the low-speed compressor; and a control device which performs control for closing, or reducing openings of, both the bypass valves in a low-rotation operation region to perform supercharging with the low-speed exhaust turbosupercharger, while opening, or increasing the openings of, both the bypass valves in a high-rotation operation region to perform supercharging with the high-speed exhaust turbosupercharger, as well as maintaining a number of rotation of the low-speed exhaust turbosupercharger at or near a predetermined number of rotation.SELECTED DRAWING: Figure 1 |
