Control apparatus for internal combustion engine

A control apparatus for an internal combustion engine, comprising:

• valve stop means for changing an operating state of at least one valve among an intake valve and an exhaust valve between a valve operating state and a closed-valve stopped state;
• fuel-cut operation execution means for executing a fuel-cut operation in a case where a predetermined execution condition is established during operation of the internal combustion engine;
• valve stopping execution means for performing valve stopping control that changes an operating state of the at least one valve to the closed-valve stopped state when executing the fuel-cut operation;
• poisoning correlation value acquisition means for acquiring a poisoning correlation value that has a correlation with progression of rich poisoning of a catalyst that is arranged in an exhaust passage of the internal combustion engine;
• poisoning determination means for determining whether or not rich poisoning of the catalyst has progressed based on the poisoning correlation value;
• and
• oxygen supply means for supplying oxygen to the catalyst in a case where it is determined that the rich poisoning of the catalyst is in a progressed state when executing the fuel-cut operation,
• wherein the oxygen supply means includes valve stopping prohibition means for prohibiting the valve stopping control by the valve stopping execution means, and for supplying oxygen to the catalyst by prohibiting the valve stopping control,
• wherein the poisoning determination means includes poisoning recovery determination means for determining whether or not the catalyst has recovered from the rich poisoning while the valve stopping control is being prohibited by the valve stopping prohibition means, and
• wherein the control apparatus for an internal combustion engine further comprises valve stopping prohibition release means for releasing prohibition of the valve stopping control by the valve stopping prohibition means if it is determined that the catalyst has recovered from the rich poisoning.