Exhaust purification system for internal combustion engine
US9297288B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2011 |
| Grant date | Mar 29, 2016 |
| Priority date | — |
| Expiry date | Feb 19, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Provided is an exhaust purification system for an internal combustion engine. The exhaust purification system comprising: a NOX purifying catalyst arranged in an exhaust passage of the internal combustion engine, wherein the NOX purifying catalyst comprises a base metal supported on a catalyst support; an oxygen sensor arranged at the downstream side of the NOX purifying catalyst in the exhaust passage; and an air-fuel, ratio control means for controlling the air-fuel ratio of exhaust gas flowing into the NOX purifying catalyst; wherein when the NOX purifying catalyst suffers from predetermined oxygen poisoning, the air-fuel ratio control means controls the air-fuel ratio of the exhaust gas, which flows into the NOX purifying catalyst, to a first air-fuel ratio wherein the first air-fuel ratio is richer than a theoretical air-fuel ratio, and then the air-fuel ratio control means switches the air-fuel ratio of the exhaust gas, which flows into the NOX purifying catalyst, to a second air-fuel ratio on the basis of an output value from the oxygen sensor wherein the second air-fuel ratio is leaner than the first air-fuel ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.