Two-stroke engine for portable tool comprises transfer conduit connecting crankshaft case to combustion chamber and air conduit connected through piston port with transfer conduit inlet port

摘要

The engine comprises a transfer conduit (11,12) which, in a predetermined piston positions, connects the crankshaft case (6) to the combustion chamber. The engine has a pure air path (24) which includes an air conduit (15), a piston port (16) and the transfer conduit. The air conduit is connected through the piston port, in predetermined piston positions, with the transfer conduit inlet port. The flow direction in the pure air path from the inlet (29) in the cylinder to the outlet (30) of the piston port extends regularly in a plane perpendicular to the cylinder longitudinal axis in at least one piston position.