CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

In an exhaust path of an internal combustion engine, a catalyst, a first air-fuel ratio sensor installed upstream thereof, and a second air-fuel ratio sensor installed downward thereof are disposed. An air-fuel ratio of the engine is controlled to a rich air-fuel ratio or a lean air-fuel ratio. In a state that is determined as a state where the catalyst stores oxygen to an upper limit after the air-fuel ratio is switched to the lean air-fuel ratio from the rich air-fuel ratio, or a state where the catalyst releases oxygen to a lower limit after the air-fuel ratio is switched to the rich air-fuel ratio from the lean air-fuel ratio, a first output from the first air-fuel ratio sensor, and a second output from the second air-fuel ratio sensor are detected and based on a difference therebetween the output of the first air-fuel ratio sensor is corrected.

主权项

1. A control device for an internal combustion engine that includes a catalyst installed in an exhaust path and having an oxygen storage capacity, a first air-fuel ratio sensor installed upstream of the catalyst, a second air-fuel ratio sensor installed downstream of the catalyst, and control means for controlling an air-fuel ratio of the internal combustion engine to a rich air-fuel ratio that is richer than a theoretical air-fuel ratio, or a lean air-fuel ratio that is leaner than the theoretical air-fuel ratio, the control device comprising:
detection means for detecting a first output that is an output of the first air-fuel ratio sensor, and a second output that is an output of the second air-fuel ratio sensor, in a state that is determined as reaching a first state where the catalyst stores oxygen to an upper limit of an oxygen storage amount after the air-fuel ratio is switched to the lean air-fuel ratio from the rich air-fuel ratio, or a second state where the catalyst releases oxygen to a lower limit of the oxygen storage amount after the air-fuel ratio is switched to the rich air-fuel ratio from the lean air-fuel ratio; and correction means for correcting a first relation of the output of the first air-fuel ratio sensor, and a value of an air-fuel ratio that is calculated in accordance with the output of the first air-fuel ratio sensor, based on a first difference between the first output and the second output.