FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: in proposed internal combustion engine a new method of compression of air-fuel mixture till ignition in one combustion chamber is used being provided by "pin" piston and air-fuel mixture aftercompression piston cylinder spaces of which are in constant communication with combustion chamber space and piston-compressor whose cylinder space is separated from combustion chamber space. Compression of air-fuel mixture in combustion chamber is provided by "pin" piston, piston-compressor and air-fuel mixture aftercompression piston whose eccentric is in crankcase until "pin" piston reaches TDC, and after-compression of air-fuel mixture to ignition is created by after-compression piston after "pin" piston passes TDC. This guarantees absence of knocking and effective use of high pressure hot gases as "pin" piston of reduced diameter is used in engine on which high pressure gases act in corresponding reduced diameter cylinder with corresponding reduced working capacity. EFFECT: reduced consumption of fuel. 3 cl, 4 dwg
