Air-fuel ratio control apparatus for internal combustion engine

Power plants – Internal combustion engine with treatment or handling of... – Having means analyzing composition of exhaust gas

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60277, 60285, 123688, F01N 300

Patent

active

058756280

ABSTRACT:
In an internal combustion engine in which air-fuel ratio feedback control is performed using an A/F sensor mounted upstream of an exhaust gas purifying catalyst, a deviation in the characteristic of the A/F sensor is estimated and the air-fuel ratio feedback control and catalyst deterioration judging processes are performed accounting for the estimated deviation. If the characteristic of the A/F sensor deviates in an output increasing direction, the amount of fuel correction will become excessively large, and the period from the time an output voltage VAF crosses a target voltage VAFT to the time it returns to the target voltage will become short compared with a normally functioning A/F sensor. On the other hand, if the characteristic of the A/F sensor deviates in an output decreasing direction, the amount of fuel correction will become excessively small, and that period will become long compared with a normally functioning A/F sensor. In the present invention, the output voltage VAF of the A/F sensor is monitored, and its amplitude VP and period CPER are calculated; then, based on the relationship between them, a correction factor K for correcting VAF based on the characteristic deviation is obtained. Instead of the amplitude VP and period CPER, a response curve length and an area enclosed by VAF and VAFT may be used.

REFERENCES:
patent: 5279116 (1994-01-01), Shimizu et al.
patent: 5301501 (1994-04-01), Shimizu et al.
patent: 5303548 (1994-04-01), Shimizu et al.
patent: 5311737 (1994-05-01), Komatsu et al.
patent: 5359853 (1994-11-01), Shimizu
patent: 5377484 (1995-01-01), Shimizu
patent: 5412941 (1995-05-01), Suzuki et al.
patent: 5417058 (1995-05-01), Shimizu
patent: 5485382 (1996-01-01), Seki et al.
patent: 5533332 (1996-07-01), Uchikawa

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