Diagnostic apparatus and method of fuel vapor purge system
US6371089B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Oct 26, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S903/903
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A fuel vapor purge system has a canister for adsorbing fuel vapor from a fuel tank, a bypass passage bypassing the canister, and a bypass valve for controlling the state of connection of the bypass passage to a purge passage. The bypass passage is provided with a venturi so that the flow passage resistance of the bypass passage is normally greater than the flow passage resistance of the canister. The amount of flow of gas from an air chamber to an intake passage changes in accordance with the flow passage resistance of the passage. In this case, the tank internal pressure in the air chamber converges to a value corresponding to the flow passage resistance of the passage between the air chamber and the intake passage. Therefore, based on the tank internal pressure occurring before and after the supply of a drive signal to the bypass valve, it is determined whether the bypass passage has a clogged abnormality and whether the bypass valve has a fixation abnormality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.