Control apparatus for internal combustion engine

摘要

Provided is a control apparatus for an internal combustion engine that can favorably achieve compatibility between suppressing deterioration of a catalyst and suppressing progression of rich poisoning thereof when the internal combustion engine has a configuration that performs valve stopping control during a fuel-cut operation. Variable valve operating apparatuses are provided having valve stop mechanisms that can respectively change an operating state of an intake valve and an exhaust valve between a valve operating state and a closed-valve stopped state. When an integrated fuel injection amount is equal to or greater than a predetermined value β when executing a fuel-cut operation, it is determined that rich poisoning of an upstream catalyst is in a progressed state. In that case, valve stopping control of the intake and exhaust valves is prohibited to thereby supply oxygen to the upstream catalyst.

主权项

1. 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.