Control apparatus for internal combustion engine

摘要

Valve stopping control is performed that changes an operating state of an intake valve and an exhaust valve to a closed-valve stopped state when executing a fuel-cut operation. A device is provided that sets an in-cylinder return-time target air-fuel ratio for an initial two return cycles when returning from a fuel-cut operation. The return-time target air-fuel ratio is set so that respective air-fuel ratios of air-fuel mixtures of fuel and air injected into the same cylinder for respective cycles during the initial return cycles each become values that fall within a combustible range, and so that even if a total amount of fuel injected into the same cylinder for the initial return cycles is supplied into the cylinder during an arbitrary single cycle, the air-fuel ratio of the air-fuel mixture of the total amount of fuel and air becomes a value that falls within the combustible range.

主权项

1. A control apparatus for an internal combustion engine, comprising:
a fuel injection valve that injects fuel into an intake passage or into a cylinder; a valve stop mechanism that is capable of 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 that executes 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 that executes valve stopping control that changes an operating state of the at least one valve from the valve operating state to the closed-valve stopped state at a time of execution of the fuel-cut operation; fuel-cut operation return request detection means that detects a request to return from the fuel-cut operation; valve return execution means that, when the request to return from the fuel-cut operation is detected, in synchrony with or in advance of an operation to resume fuel injection, executes a valve return operation that changes the operating state of the at least one valve from the closed-valve stopped state to the valve operating state; and return-time air-fuel ratio setting means that sets an in-cylinder target air-fuel ratio in initial return cycles that corresponds to an initial at least two cycles at a time of return from the fuel-cut operation, wherein the target air-fuel ratio is set so that respective air-fuel ratios of air-fuel mixtures of fuel and air injected into a same cylinder for respective cycles during the initial return cycles each become a value that falls within a combustible range, and is also set so that even if a total amount of fuel that is injected into a same cylinder for the initial return cycles is supplied into the cylinder during an arbitrary single cycle, an air-fuel ratio of an air-fuel mixture of the total amount of fuel and air becomes a value that falls within the combustible range.