| 摘要 |
PURPOSE:To attempt to increase the power of an engine by providing a valve opening and closing in the after period of an exhaust stroke in an exhaust air passage making detour around a turbo charger and introducing only an exhaust pressure pulse of high pressure in the former period of the exhaust stroke to the turbine. CONSTITUTION:In an internal combustion engine having a first exhaust passage 12a communicating cylinders of the engine 11 respectively with the turbine 7A of a supercharger 7, a second exhaust passage 12b communicating cylinders with an exhaust passage 4 at the downstream of the turbine 7A are provided, and the passage 12b is opened and closed by a valve 13 provided in the cylinder head of each cylinder 2. The timing of this valve 13 is set so that the valve 13 is opened and closed in a period from the after period of the exhaust stroke to the initial period of the suction stroke, by utilizing a valve mechanism for driving suction and exhaust valves 5 and 6. Accordingly, the increase in the exhaust pressure in the engine high rotation region is suppressed, and lowering of the filling efficiency of the engine and the increase in the pumping efficiency are evaded. |
