Oxygen sensor control system
US4202301A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1977 |
| Grant date | May 13, 1980 |
| Priority date | — |
| Expiry date | Aug 31, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/148
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-to-fuel ratio control mechanism in an internal combustion engine operates in partial response to the output of a control circuit, which circuit in turn is responsive to the output of an oxygen sensor mounted in the exhaust of the engine. The control circuit biases the control mechanism toward a predetermined desired air-to-fuel ratio, normally at or near stoichiometric. When the sensor output deviates above a first predetermined value or below a second predetermined value for longer than a predetermined time period, a comparator circuit provides a disabling signal which disconnects the control circuit from the air-to-fuel ratio control mechanism. At the same time, the disabling signal connects a predetermined signal to the air-to-fuel ratio control mechanism. This predetermined signal simulates a nominal control circuit output to maintain the air-to-fuel ratio close to stoichiometric or some other preferred setting such as a air/fuel ratio which is lean. An indicator is turned on by the disabling signal to alert the operator to possible malfunction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.