| 摘要 |
FIELD: mechanical engineering. ^ SUBSTANCE: invention relates to scavenged two-stroke crankcase internal combustion engine in which at least one air channel opened by piston is formed between air supply branch pipe and upper part of row of transfer channels. Fresh air is added in upper part of transfer channels being used as buffer for air-fuel mixture below, thanks to which fuel consumption and emission of combustion products with exhaust gases are reduced. Engine is designed mainly for hand tools. Proposed engine contains at least one air channel opened by piston with length being formed between air supply branch pipe and scavenging ports of row of transfer channels with length from scavenging port to crankcase. Air channel from air supply branch pipe is furnished with limiting valve operated by at least one parameter of engine, for instance, by carburetor throttle valve control. Air supply branch pipe passes through at least one connecting channel to at least one connecting hole in engine cylinder wall. Connecting hole is formed to get connected with cavities in piston when piston is in top dead center. Cavities in piston intersect with corresponding scavenging ports of row of transfer channel being made so that duration of air delivery determined as crank turning angle or time interval is equal to engine intake time. Length of intake channel into which fuel is added exceeds 0.6 of summary length of air channel opened by piston and length of transfer channels, i.e. it is greater than but less than 1.4 of the same length, i.e. ^ EFFECT: improved reliability in operation. ^ 10 cl, 2 dwg |
