Exhaust emissions control system
US4364356A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 25, 1974 |
| Grant date | Dec 21, 1982 |
| Priority date | — |
| Expiry date | Jan 25, 1994 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1481
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Exhaust emissions control system provides effective control of hydrocarbons, carbon monoxide, and nitrogen oxides by adjusting the air-fuel ratio of an internal combustion engine having a catalytic converter in its exhaust path in response to the percentage oxygen content of the exhaust gases as measured by a voltage generating oxygen sensor positioned in the exhaust path. The electrical signal produced by the oxygen sensor is compared to a set point signal which corresponds to the desired oxygen content which prevails when the conversion of the exhaust gases is optimized and a correcting step adjustment is made in the air-fuel ratio when there is a difference in the signals. To minimize hunting and still provide a relatively rapid response, the system incorporates a time delay to permit each adjustment made in the air-fuel ratio to be reflected in the output of the exhaust gases before the oxygen content of such exhaust gases is sensed preliminary to make succeeding step adjustments. By providing a time delay equal to the time required for a predetermined number of engine revolutions, the length of the delay can be varied greatly so as to closely approximate the different response…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.