METHOD OF GAS EXCHANGE IN TWO-STROKE ICE Russian patent published in 2013 - IPC F02B25/08 

FIELD: engines and pumps.

SUBSTANCE: combustion products are vented from cylinder cavity via openings released by the piston and directed into atmosphere via exhaust manifold. Then, cylinder cavity is scavenged by fresh charge and filled via inlet ports cleared by the piston to bypass the fresh charge portion from cylinder cavity into exhaust manifold tight after combustion chamber with filling the part of exhaust manifold with said fresh charge. Then, exhaust manifold is shut off by slide valve timed with piston to bar the combustion products for increase in exhaust manifold pressure upstream of said slide valve. Thereafter, increased gas pressure upstream of said slide valve displaces the fresh charge fed in exhaust manifold back towards the cylinder. Thus fresh charge is forced from exhaust manifold shutoff by slide valve into cylinder cavity via open outlet ports by the energy of combustion products. Now, inlet and outlet ports are closed by the piston at the compression stroke start. Note here that before closure of inlet ports by the piston, at least, before said moment, pressure outside the cylinder, in the area of inlet ports, is increased to constrict the fresh charge release from cylinder cavity.

EFFECT: higher specific power of two-stroke engine.

3 cl, 6 dwg