| 摘要 |
A vertical internal combustion engine having overhead valves, a vertically disposed crankshaft and a horizontally disposed cylinder, wherein a carburettor (62) is fixed on one side of the cylinder and an exhaust muffler (65) is fixed on the other side of the cylinder, the configurations of a suction port (58) and an exhaust port (61) being improved, whereby the fluidity of air-fuel mixture in the engine, the cooling effect of cooling air, and maintenance are enhanced. In one embodiment, a suction port (58), coupled to the carburettor, has a horizontal straight portion (59) and a curved portion (60) leading to a suction valve (52); and the central axis (59a) of said horizontal straight portion (59) and the central axis (61a) of an exhaust port (61) connected with said exhaust muffler (65) extending through an exhaust valve (53) and crossing said horizontal straight portion (59) obliquely from below. In another embodiment, a suction valve (52) is arranged in a lower part of the cylinder head (51b) ; a suction port (58) which leads downwardly to said suction valve (52) opens on one side of the cylinder head (51b); the carburettor (62) is connected with the suction port (58), an exhaust port (61) opens in such a way that the centre line (61a) of the exhaust port extends through the exhaust valve (53) and crosses a horizontal line (100) from above, and the muffler (65) is fixed directly to the exhaust port (61). <IMAGE> <IMAGE> <IMAGE> <IMAGE> |
