Emission control apparatus with reduced hangover time to switch from open- to closed-loop control modes
US4132200A · kind A · utility
26Cited by
10References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1977 |
| Grant date | Jan 2, 1979 |
| Priority date | — |
| Expiry date | Feb 11, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/149
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A closed-loop emission control apparatus for internal combustion engines includes exhaust composition sensor for feedback control of the air-fuel mixture. When the temperature in the exhaust passage is lower than the operating temperature of the sensor, control is switched to an open-loop mode. The feedback control signal is fluctuated above and below a predetermined DC bias at periodic intervals during the open-loop mode to switch the control to the closed-loop mode in a minimum transition time as soon as the sensor's temperature condition warrants feedback control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.