INTERNAL-COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To effect knocking-free combustion in satisfactory thermal efficiency. SOLUTION: A piston 3 is slidably provided in a cylinder. An ignition source 1 is provided in a cylinder head 2 is actuated to fire the mixture in a combustion chamber 7 formed on the upside of the piston 3. A grooved piston cavity 6 which serves as the combustion chamber 7 is formed on the upside of the piston 3. A similar figure is formed between the corner on the bottom of the piston cavity 6 and a burning surface 8 composed of the surface of propagating flames after fired by the ignition source 1, by making the ratio of the corner curvature R on the bottom of the piston cavity 6 to a diameter D1 of the piston 3 R/D1>=0.2. Then generation of the unburned area 9 in combustion is minimized.