Abstract: An internal combustion engine has a separate exhaust passage for each one of banks. An exhaust purifying catalyst is provided in each exhaust passage. The mass flow rates G1, G2 of exhaust gas that flow through the exhaust passages are individually estimated. The flow rate of exhaust gas is individually adjusted per each bank by controlling the operation of each one of exhaust gas recirculation valves such that the difference between the estimated mass flow rates G1, G2 is decreased.

Abstract: In an exhaust gas control apparatus and exhaust gas control method for an internal combustion engine, in which fuel is supplied to a purification mechanism provided in an exhaust passage so that a function of the purification mechanism is recovered. A flow rate of exhaust gas flowing in the exhaust passage or a value correlated with the flow rate is detected, and fuel supply timing is controlled based on a result of the detection. Accordingly, even when the flow rate of the exhaust gas flowing in the exhaust passage is variously changed based on the engine operating state, the fuel supply timing can be set based on the flow rate that is appropriately detected. Thus, it is possible to appropriately convey the supplied fuel to the purification mechanism using force of the exhaust gas.

Abstract: Decreases in the volume of intake air to an engine in response to environmental changes results in an increase in amount of PM emissions. In view of this situation, a correction coefficient of fuel supply interval is calculated based on the variation in amount of PM emissions to adjust a reference fuel supply interval in order to determine an target fuel supply interval. By adjusting the fuel supply interval, a fuel supply amount appropriate to the variation in amount of PM emissions, thereby preventing clogging of the injection hole of a supplemental fuel valve, while maintaining fuel economy.

Abstract: An internal combustion engine has a separate exhaust passage for each one of banks. An exhaust purifying catalyst is provided in each exhaust passage. The mass flow rates G1, G2 of exhaust gas that flow through the exhaust passages are individually estimated. The flow rate of exhaust gas is individually adjusted per each bank by controlling the operation of each one of exhaust gas recirculation valves such that the difference between the estimated mass flow rates G1, G2 is decreased.

Abstract: In an exhaust gas control apparatus and exhaust gas control method for an internal combustion engine, in which fuel is supplied to a purification mechanism provided in an exhaust passage so that a function of the purification mechanism is recovered. A flow rate of exhaust gas flowing in the exhaust passage or a value correlated with the flow rate is detected, and fuel supply timing is controlled based on a result of the detection. Accordingly, even when the flow rate of the exhaust gas flowing in the exhaust passage is variously changed based on the engine operating state, the fuel supply timing can be set based on the flow rate that is appropriately detected. Thus, it is possible to appropriately convey the supplied fuel to the purification mechanism using force of the exhaust gas.