FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: proposed four-stroke combination internal combustion (diesel) engine employs for its operation a new method of compression of air-fuel mixture: use is made of reduced diameter working piston, arranged in corresponding smaller diameter cylinder whose working volume provides building of maximum 90% of designed value of air-fuel mixture compression ratio in combustion chamber required for compression ignition, and finishing compression larger diameter piston providing designed value of air-fuel mixture compression ratio required for compression ignition and arranged in larger diameter cylinder. Engine has irregular shape eccentric which provides normal operation of air-fuel mixture finishing compression mechanism corresponding to operating conditions of engine. Finishing compression mechanism guarantees timely ignition of air-fuel mixture and, together with smaller diameter working piston fitted in reduced diameter cylinder, with reduced working volume, provides effective use of high-pressure hot gases in reduced volume of working cylinder. EFFECT: increased fuel economy owing to use of high-pressure hot gases in reduced volume of reduced diameter cylinder. 3 cl, 2 dwg
