Positive pressure canister purge system integrity confirmation
US5411004A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1993 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | Feb 3, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M2025/0845
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The tank/canister volume's integrity against unacceptable leakage measured by a diagnostic test performed by an on-board diagnostic system which includes an electrically operated air pump and tank-mounted analog pressure transducer. At the beginning of a test, the engine management computer closes the canister purge solenoid valve and operates the pump to begin pressurization of the tank/canister volume. The pumped air is introduced via the canister's atmospheric vent port at a regulated pressure. Failure to build tank pressure to a predetermined pressure within a predetermined time indicates a gross leak. If no gross leak exists, the pressure will build, and the time required to build to a given pressure from the start pressure provides a measurement of any leakage that may be present. The fuel fill level in the tank affects this time, and it is taken into account in the measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.