Exhaust gas control apparatus and exhaust gas control method for internal combustion engine

An exhaust gas control apparatus 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, comprising:

• a sensor which is provided in the exhaust passage, and which performs detection of a flow rate of exhaust gas flowing in the exhaust passage or a value correlated with the flow rate;
• a controller which controls fuel supply timing at which the fuel is supplied, based on a result of the detection performed by the sensor;
• and
• wherein the controller sets the fuel supply timing not at constant load, such that a time interval is provided between timing at which a variation tendency of the detected flow rate of the exhaust gas changes from an increasing tendency to a decreasing tendency and the fuel supply timing at which the fuel is supplied, and
• wherein the fuel is supplied from a fuel supply valve that is provided upstream of the purification mechanism in the exhaust passage of the internal combustion engine.

An 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, comprising:

• performing detection of a flow rate of exhaust gas flowing in the exhaust passage or a value correlated with the flow rate;
• controlling fuel supply timing at which the fuel is supplied, based on a result of the detection;
• and
• setting the fuel supply timing such that the fuel is supplied not at constant load but at local maximum, when a variation tendency of the flow rate of the exhaust gas changes from an increasing tendency to a decreasing tendency, based on a result of the detection.

An 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, comprising:

• performing detection of a flow rate of exhaust gas flowing in the exhaust passage or a value correlated with the flow rate;
• controlling fuel supply timing at which the fuel is supplied, based on a result of the detection;
• and
• setting the fuel supply timing not at constant load, such that a time interval is provided between timing at which a variation tendency of the detected flow rate of the exhaust gas changes from an increasing tendency to a decreasing tendency and the fuel supply timing at which the fuel is supplied, and
• wherein the fuel is supplied from a fuel supply valve that is provided upstream of the purification mechanism in the exhaust passage of the internal combustion engine.