摘要 |
Crankcase scavenged two-stroke internal combustion engine ( 1 ), in which a piston ported air passage is arranged between an air inlet ( 2 ) and the upper part of a number of transfer ducts ( 3, 3 '). The air inlet is equipped with a restriction valve ( 4 ), controlled by at least one engine parameter, for instance the carburettor throttle control. The air inlet extends via at least one connecting duct ( 6, 6 ') to at least one connecting port ( 7, 7 ') in the engine's cylinder wall ( 12 ). The connecting port ( 7, 7 ') is arranged so that it in connection with piston positions at the top dead center is connected with flow paths ( 9, 9 ') embodied in the piston ( 13 ), which extend to the upper part of a number of transfer ducts ( 3, 3 '), and the flow paths in the piston are so arranged that the recess ( 10, 10'; 11, 11 ') in the piston that meets the respective transfer duct's port ( 31, 31 ') is so arranged that the air supply is given an essentially equally long or longer period, counted as crank angle or time, in relation to the fuel and air mixture inlet period.
|