CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

A control apparatus for an internal combustion engine includes an electronic control unit. The electronic control unit corrects a target air-fuel ratio in an air-fuel ratio control with a first correction value set based on a degree of variation among cylinders in terms of a fuel amount to be injected from the port injector, and a second correction value set based on a degree of variation among the cylinders in terms of a fuel amount to be injected from the in-cylinder injector. A first correction amount of the target air-fuel ratio by the first correction value is set to be larger as an injection amount ratio of the intake-port fuel injection valve is larger, and a second correction amount of the target air-fuel ratio by the second correction value is set to be larger as an injection amount ratio of the in-cylinder fuel injection valve is larger.

主权项

1. A control apparatus for an internal combustion engine, the control apparatus comprising:
an intake-port fuel injection valve provided in each of a plurality of cylinders, the intake-port fuel injection valve being configured to inject fuel into an intake port of the internal combustion engine; an in-cylinder fuel injection valve provided in each of the plurality of cylinders of the internal combustion engine, the in-cylinder fuel injection valve being configured to inject fuel into a combustion chamber of the internal combustion engine; a catalyst provided in an exhaust passage of the internal combustion engine, the catalyst being configured to purify gas exhausted from the internal combustion engine; an upstream-side sensor configured to output an output value corresponding to an actual air-fuel ratio on an upstream side relative to the catalyst; and an electronic control unit configured to:
(i) change, according to an engine operation state, injection amount ratios of the fuel to be injected from the intake-port fuel injection valve and the fuel to be injected from the in-cylinder fuel injection valve, relative to a total fuel amount to be injected from the intake-port fuel injection valve and the in-cylinder fuel injection valve,(ii) execute an air-fuel ratio control of controlling the actual air-fuel ratio to a target air-fuel ratio by correcting the total fuel amount such that the output value of the upstream-side sensor achieves an output value corresponding to the target air-fuel ratio,(iii) detect a first variation degree indicative of a degree of variation among the cylinders in terms of a fuel amount to be injected from the intake-port fuel injection valve,(iv) detect a second variation degree indicative of a degree of variation among the cylinders in terms of a fuel amount to be injected from the in-cylinder fuel injection valve,(v) set a first correction value based on the first variation degree such that a first correction amount of the target air-fuel ratio by the first correction value is set to be larger as the injection amount ratio of the intake-port fuel injection valve is larger,(vi) set a second correction value based on the second variation degree such that a second correction amount of the target air-fuel ratio by the second correction value is set to be larger as the injection amount ratio of the in-cylinder fuel injection valve is larger, and(vii) correct the target air-fuel ratio with the first correction value and the second correction value.