Diagnostic apparatus for air-fuel ratio sensor

Internal-combustion engines – Charge forming device – Including exhaust gas condition responsive means

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

731181, F07D 4114

Patent

active

057586322

ABSTRACT:
The fuel ratio control system controls the supply of fuel to an internal combustion engine to achieve a target air-fuel ratio, based on the output of an air-fuel ratio sensor. The system may determine whether there is an abnormality in the air-fuel ratio sensor based on a comparison between a change of an air-fuel ratio correction coefficient, used to drive the air-fuel ratio to the target value, and a change of the target air-fuel ratio if the target air-fuel ratio has sharply changed. Alternatively, the diagnosis operation may be performed based on a comparison between a total air-fuel ratio correction amount and a change of the air-fuel ratio detected by the air-fuel ratio sensor, a phase difference calculation between peaks of the air-fuel ratio or the air-fuel ratio correction coefficent, or by accumulating the differences between the air-fuel ratio and the target air-fuel ratio, and the differences between the air-fuel ratio correction coefficient and a reference value, and comparing the accumulated values. In addition, the system may detect a sensor abnormality based on the deviation in phase of the air-fuel ratio from the air-fuel ratio correction coefficient. These system may also detect sensor abnormality on the basis of the behavior of the air-fuel ratio during transitional engine operation. As a result, the air-fuel ratio control system will not use an imprecise output from the sensor for air-fuel ratio control, thus achieving highly precise and highly reliable air-fuel ratio control.

REFERENCES:
patent: 4724814 (1988-02-01), Mieno et al.
patent: 4915081 (1990-04-01), Fujimoto et al.
patent: 5058556 (1991-10-01), Fukuma et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Diagnostic apparatus for air-fuel ratio sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Diagnostic apparatus for air-fuel ratio sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diagnostic apparatus for air-fuel ratio sensor will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1450075

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.