Air fuel ratio detecting device
US4891121A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1987 |
| Grant date | Jan 2, 1990 |
| Priority date | — |
| Expiry date | Jul 30, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4065
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An air fuel ratio detecting device which is improved in accuracy as compared to similar prior art devices comprises a sensor cell for developing an electrical signal in response to the difference between the concentration of oxygen in the exhaust gas and the concentration of oxygen in a reference gas, a controlling means for developing an electrical control signal having a polarity determined from the output of the sensor cell, a pump cell for moving oxygen ions in response to the electrical control signal received from the controlling means, a control current detecting means for detecting control current flow between the controlling means and the pump cell, an air fuel ratio detecting means for detecting the air fuel ratio from the control current flow, a stoichiometric air fuel ratio detecting means for detecting the direction of the control current flow so as to determine the stoichiometric air fuel ratio, a storage means for storing therein a linear air fuel ratio value which is determined in a predetermined functional relationship with respect to the magnitude of the control current flow, a linear air fuel ratio detecting means for detecting the magnitude of the control curren…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.