Abnormality diagnosis apparatus for exhaust purification system
US8240130B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 2008 |
| Grant date | Aug 14, 2012 |
| Priority date | — |
| Expiry date | Apr 4, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In an exhaust purification system having a urea addition device adding a urea aqueous solution to an NOx catalyst of selective reduction type provided in an exhaust passage in an internal combustion engine, a sensor detecting an ammonia concentration is provided at the downstream side of the NOx catalyst. During fuel cut, a predetermined amount of urea aqueous solution is added. Then, based on a sensor output obtained at this time, an abnormality in at least one of the urea addition device and the urea aqueous solution is detected. The addition of the urea aqueous solution during the fuel cut prevents reactive consumption between urea and NOx. The sensor output corresponding to the amount of the urea aqueous solution is obtained. This output condition is compared with a normal one to allow determination of whether or not an appropriate amount of urea aqueous solution of appropriate quality has been added.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.