Diagnostic apparatus for fuel vapor purge system
US6474148B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2001 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | May 14, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0818
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A diagnostic apparatus for a fuel vapor purge system is provided which includes a pressure sensor that measures a pressure in a fuel tank, and which conducts leak diagnosis of a purge path based on a change in the pressure in the fuel tank and an amount of fuel vapor generated in the fuel tank. The change in the pressure is measured after sealing the purge path while providing a difference between inside pressure and outside pressure of the purge path, and the amount of fuel vapor is measured after applying an atmospheric pressure to the purge path and sealing the purge path. The diagnostic apparatus further detects a predetermined state after starting application of the atmospheric pressure to the purge path, and determines that the purge path has reached an atmospheric pressure state upon. detection of the predetermined state. The amount of fuel vapor generated in the fuel tank is measured when it is determined that the purge path has reached the atmospheric pressure state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.