Defect diagnosing apparatus of evaporation purge system
US5845625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1997 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Jul 16, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0836
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Three-way VSV switches a passage in communication with pressure sensor either to the atmosphere or to three-way VSV. The three-way VSV is provided in bypass passage connecting fuel tank with canister to switch the path to the fuel tank side or to the canister side with respect to tank internal-pressure control valve. As properly switching the three-way VSVs, the pressure sensor can detect both the pressure in the evaporation purge system and the atmospheric pressure. Upon diagnosis of defect a difference is calculated between the in-system pressure and the atmospheric pressure detected, which cancels out the dispersion or the like upon production of the pressure sensor, thus enabling to detect an accurate pressure change.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.