Patent ID: 7537382

Claim:
A gas mixture temperature estimation method for an internal combustion, the method comprising: estimating a temperature of a gas mixture produced through mixing of fuel injected into a combustion chamber of the internal combustion engine and a cylinder interior gas, which is a gas having been taken into the combustion chamber, wherein: when the gas mixture does not stagnate, a heat transfer does not occur between the gas mixture and an object or substance existing around the gas mixture and the temperature of the gas mixture is calculated based on a quantity of a heat of the fuel injected into the combustion chamber and a quantity of a heat of the cylinder interior gas, and when the gas mixture stagnates in a generally annular configuration in the vicinity of a side wall of the combustion chamber, the heat transfer occurs between the gas mixture and the object or substance existing around the gas mixture during a period in which the gas mixture stagnates and the temperature of the gas mixture is calculated based on the quantity of the heat of the fuel injected into the combustion chamber, the quantity of the heat of the cylinder interior gas, and a quantity of a heat transferred between the gas mixture and the object or substance existing around the gas mixture.