Patent attributes
An operating gas circulation type internal combustion engine that uses argon as the operating gas, for example, and includes a hydrogen and oxygen supply portion, an argon supply amount regulating portion, and an electric control unit. The electric control unit determines the amount of hydrogen and oxygen to be supplied to a combustion chamber based on a required torque, which is the torque required of the internal combustion engine, and supplies the determined amounts of hydrogen and oxygen to the combustion chamber using the hydrogen supply portion and the oxygen supply portion. Further, the electric control unit determines an amount of operating gas to be supplied to the combustion chamber according to the required torque, and controls the argon supply amount regulating portion such that the determined amount of operating gas is supplied to the combustion chamber.