Method and system for monitoring an evaporative purge system
US5614665A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Aug 16, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0809
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and system for monitoring an evaporative purge system for malfunctions and leaks. First, a plurality of predetermined entry conditions are checked for satisfaction. If the plurality of predetermined entry conditions have been met, a flow of vapor in the evaporative purge system is determined. The evaporative purge system is then sealed from atmosphere so as to pull a vacuum on the fuel tank. The vacuum is compared to a predetermined vacuum range. If the vacuum is within the predetermined vacuum range, the vacuum is allowed to stabilize to obtain a stabilized vacuum level. A decrease in the stabilized vacuum level is determined after a predetermined amount of time to obtain a vacuum bleed-up. A vacuum bleed-up acceptance threshold is then determined based on the determined flow of vapor and the vacuum bleed-up is then compared to the vacuum bleed-up acceptance threshold. If the vacuum bleed-up exceeds the vacuum bleed-up acceptance threshold, atmosphere is provided to the evaporative purge system until stabilization. The evaporative purge system is then sealed again to create a pressure build. The pressure build is compared to a pressure threshold. Finally, a malfunction si…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.