| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently reduce manufacturing costs required for preventing damage to an exhaust gas sensor by eliminating the need for instruments or the like employed for measuring the amount of condensation water accumulated in an exhaust pipe and allow reduction of exhaust gas by activating the exhaust gas sensor as early as possible.SOLUTION: An exhaust pipe wall temperature estimation part calculates an estimated wall temperature in an exhaust pipe which is determined one by one from an exhaust temperature detected from an exhaust temperature sensor, the flow rate of gas detected from an air flow meter, and an outside air temperature detected by an outside air temperature sensor by referring to a map for calculating the supplied amount of heat, a wall temperature additional value map, and a wall temperature subtraction value map. Then a dew-point temperature calculation part of an exhaust pipe wall calculates, by referring to a dew-point temperature calculation map, the dew-point temperature determined from an air-fuel ratio between the flow rate of gas and the weight of fuel. A condensation water amount estimation part determines a relative wall temperature from the estimated wall temperature and the dew-point temperature by referring to a map for calculating a condensation water accumulated amount, calculates the condensation water accumulated amount from the relative wall temperature and the flow rate of gas, and estimates a value obtained by totalizing a calculated condensation water accumulated amount as the amount of the condensation water. |
