Exhaust emission control system for internal combustion engine
US6539707B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2001 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Oct 3, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1456
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An upstream catalyst and a downstream catalyst are disposed in series in an exhaust pipe, and first through third sensors for detecting the air-fuel ratio or an adsorption amount of hazardous components on the rich/lean side of exhaust gases are disposed on the upstream and downstream sides of the upstream catalyst and the downstream side of the downstream catalyst, respectively. An ECU for controlling an engine controls the air-fuel ratio so that when the adsorption amount of the hazardous components on the rich side of the downstream catalyst is large, that of the hazardous components on the lean side of the upstream catalyst is large. Similarly, the ECU controls the air-fuel ratio so that when the adsorption amount of the hazardous components on the lean side of the downstream catalyst is large, that of the hazardous components on the rich side of the upstream catalyst is large.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.