Secondary air supply for internal combustion engine
US4586481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1984 |
| Grant date | May 6, 1986 |
| Priority date | — |
| Expiry date | Sep 4, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A secondary air intake system is used in an internal combustion engine. The system supplies secondary air through a first and a second secondary air passage. The first secondary air passage includes a first vacuum operated air control valve. The second secondary air passage includes a second vacuum operated air control valve and an electrically operated air control valve positioned in series. A vacuum control which includes an electrically operated vacuum control valve operates the first and second vacuum operated air control valves to vary the effective area of the two air passages. An air-fuel ratio control which includes an intake air temperature sensor, an exhaust gas oxygen concentration sensor and a throttle plate vacuum sensor determines the engine air-fuel ratio to intermittently open and close the second electrically operated air control valve to open and close the second secondary air passage. The air-fuel ratio control also operates the electrically operated vacuum control valve to gradually open and close the first and second vacuum operated air control valves to gradually open and close the first and second secondary air passages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.