Exhaust gas purification apparatus for an internal combustion engine
US4175386A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 25, 1977 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Feb 25, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N3/227
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A secondary air supply pipe line is opened in the exhaust pipe of an internal combustion engine on the upstream side of an exhaust gas reactor which is mounted in the exhaust pipe, and an air-fuel ratio sensor for detecting the air-fuel ratio of exhaust gases is mounted in the exhaust pipe on the downstream side of the portion where the secondary air supply pipe line is open. An air flow control valve for on-off controlling the flow of air in the secondary air supply pipe line is operated in accordance with the output signal of the air-fuel ratio sensor. When the air-fuel ratio of the exhaust gases is low the secondary air supply pipe line is fully opened by the air flow control valve in response to the output signal of the air-fuel ratio sensor, whereas when the air-fuel ratio of the exhaust gases is high the secondary air supply pipe line is fully closed by the air flow control valve in response to the output signal of the air-fuel ratio sensor, whereby maintaining the air-fuel ratio of exhaust gases supplied to the exhaust gas reactor at a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.