Control method and control device for internal combustion engine

By setting the reference oxygen storage capacity in relation to gas flow rate, the method accurately diagnoses three-way catalyst deterioration, addressing the inaccuracies in conventional methods and ensuring precise catalyst performance evaluation.

JP7740546B2Active Publication Date: 2025-09-17NISSAN MOTOR CO LTD
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Patent Information

Application Number
JP2024526183
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-06-10
Publication Date
2025-09-17
Estimated Expiration
2042-06-10

AI Technical Summary

Technical Problem

Conventional methods for diagnosing three-way catalyst deterioration in internal combustion engines fail to account for the influence of gas flow rate, leading to erroneous judgments under high flow conditions.

Method used

Set the reference oxygen storage capacity based on the gas flow rate, specifically using intake air amount as a parameter to adjust the reference oxygen storage capacity, thereby minimizing erroneous diagnoses and optimizing catalyst deterioration diagnosis.

Benefits of technology

Accurately determines catalyst deterioration by considering the impact of gas flow rate, preventing false positives and ensuring precise catalyst performance assessment.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

An internal combustion engine (1) is equipped with a three-way catalyst (15). An engine controller (9) has: an oxygen amount calculation unit (102) for obtaining an oxygen amount per time unit which flows into the three-way catalyst (15); and an oxygen storage amount calculation unit (108) for estimating the current oxygen storage amount by totaling up the positive and negative oxygen amounts. In response to an air intake amount which is outputted by an air intake amount calculation unit (101), a reference oxygen storage volume calculation unit (107) outputs a reference oxygen storage volume, the value of which becomes smaller as the air intake amount is higher. A catalyst diagnosis unit (104) determines catalyst deterioration by comparing the current oxygen storage volume and the reference oxygen storage volume, which takes the air intake amount into account.
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Citation Information

Patent Citations

  • Catalyst deterioration detecting apparatus for internal combustion engine

    JP1994212955A

  • Catalyst deterioration diagnostic device for internal combustion engine

    JP2001329832A

  • Internal combustion engine control device

    WO2012086078A1