Secondary air supply system for the exhaust system of an internal combustion engine
US4211074A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 2, 1978 |
| Grant date | Jul 8, 1980 |
| Priority date | — |
| Expiry date | May 2, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N3/227
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A secondary air supply system for the exhaust system of an internal combustion engine having a catalytic converter with a three-way catalyst. The system has an air control valve which selectively supplies a part of compressed air to the exhaust system while relieving the rest of the air to the atmosphere. The air control valve has a first valve element which controls a passage between an inlet port and an outlet port and a second valve element which controls a passage between the inlet port and a relief port, the first valve element being controlled by a first diaphragm means in an ON/OFF manner by changing-over of supply of different actuating fluid pressures depending upon monitoring of residual oxygen in exhaust gases, while the second diaphragm element is operated by a second diaphragm means which responds to the duty ratio of changing-over of the different actuating fluid pressures so as to compensate for the change of mean flow of secondary air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.