To provide a premixture compression hypergolic combustion engine for actualizing operation corresponding to a wide load range.
A combustion recessed part 7 has a gas residual portion 19 recessed outward beyond an opening peripheral edge 18 in the radial direction of a piston 4. Fresh air hardly flows into the gas residing portion 19, and so when internal EGR gas is mixed with the fresh air and compressed, an area where the concentration of the internal EGR gas is high and an area where it is low are formed in a combustion chamber 9. The internal EGR gas is high-temperature burnt gas and heat is insulated near the gas residual portion 19 by a heat insulating part 8. Thus, a high-temperature site is formed in the combustion chamber 9 near the gas residual portion 19 of the combustion recessed part 7 where the concentration of the internal EGR gas is high and such stratified temperature distribution is formed around the high-temperature site that a temperature is gradually lower as being farther from the gas residual portion 19.
Michiharu Soga
Hidetoshi Furukawa
Suzuki Kenchi
Kajinami order