| 摘要 |
The invention relates to a two-stroke engine which operates as a drive motor in a portable work apparatus such as a motor-driven chain saw. The two-stroke engine has a combustion chamber (3) which is formed in a cylinder (2) and is delimited by a piston (5) which moves up and down in the cylinder. The piston drives via a connecting rod (6) a crankshaft (7) which rotates in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (14). A first end (20) of the transfer channel (14) opens via an entry window (12) into the combustion chamber (3) and the second end (19) of the transfer channel (14) opens into the crankcase (4). The entry window (12) lies in the cylinder wall (16) and is controlled by the piston (5). The transfer channel (14) is connected to a gas channel (22) between its ends (19, 20). An essentially fuel-free gas flow (40) flows via a check valve (21) from the gas channel (22) and flows into the transfer channel (14). The mixture, which is necessary for operating the two-stroke engine (1), is drawn from a membrane carburetor (8) into the crankcase (4) via an inlet (11). The flow element (23, 33, 45) is mounted in the flow path of the gas flow (40) which exits from the gas channel (22) into the transfer channel (14). A flow element fans out the gas flow (40). In this way, a complete scavenging of the transfer channel is ensured during the induction stroke. |
