Abnormality detection apparatus for preventing fuel gas emission
US6082337A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Jul 10, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0809
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
When a diagnosis execution condition is established, a canister closure valve is closed, thereafter, a purge control valve is opened, a purge control valve is closed in a state where negative pressure is introduced into an evaporated gas system to thereby maintain the evaporated gas system in a hermetically-sealed state and the hermetically-sealed state is continued until abnormality diagnosis is finished. Time period for maintaining the evaporated gas system in the hermetically-sealed state is divided into three time periods of a pressure change determining time period at a first time, an awaiting time period and a pressure change determining time period at a second time. After determining a pressure change amount DPT1 of the evaporated gas system in the pressure change determining time period at the first time, the evaporated gas system is successively maintained in the hermetically-sealed state, after the predetermined awaiting time period has elapsed, the pressure change determination at the second time is carried out by which a pressure change amount DPT2 of the evaporated gas system is determined. Further, presence or absence of leakage of the evaporated gas system is diagnos…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.