Patent · US Expired

Device for determining deterioration of a catalytic converter for an engine

US5412941A · kind A · utility

17Cited by
4References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 2, 1993
Grant dateMay 9, 1995
Priority date
Expiry dateMar 2, 2013

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/40
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

A device for determining a deterioration of the catalytic converter for an engine equipped with a catalytic converter disposed in the exhaust passage and upstream and downstream air-fuel ratio sensors disposed in the exhaust passage upstream and downstream of the catalytic converter, respectively. The device also determines whether the three-way catalyst in the catalytic converter has deteriorated based on the output signal of the downstream air-fuel ratio sensor when the air-fuel ratio of the engine is feedback controlled by the output of the upstream air-fuel ratio sensor, wherein the execution of the determining operation of catalyst deterioration is prohibited when the period of the cycle of the air-fuel ratio feedback control becomes longer than a predetermined value, thereby preventing errors from accuracy in the determination.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.