| 摘要 |
PURPOSE:To reduce the temperature of exhaust gas to a turbine and improve the efficiency of supercharging, by dividing at least part of an exhaust pipe upstream to the turbine, into plural pipes and by connecting these pipes to plural exhaust ports which communicate with the combustion chamber of the engine body. CONSTITUTION:In a four-cycle internal combustion engine having a single cylinder and an intake and an exhaust lines of cross flow type, two intake ports 31, 32 and two exhaust ports 41, 42 communicate with a combustion chamber 2, an exhaust pipe E is connected to the exhaust ports and the turbine T of a turbocharger S is provided in the exhaust pipe. The part Eu of the exhaust pipe upstream to the turbine T is divided into two pipes, whose upstream ends are connected to the exhaust ports 41, 42 and which are connected to each other through a communication pipe 19. An exhaust pipe Ed downstream to the turbine T is connected to the communication pipe 19 through a waste gate 20 provided with a valve 21, which is opened when the supercharging pressure is higher than a prescribed level. |
