Fuel fill vapor recovery system with differential pressure control valve
US5462100A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Aug 31, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8634
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A refueling vapor recovery system for a vehicle utilizes recirculation of a portion of the displaced vapor and combines a vapor vent valve and a recirculation control into a single differential pressure valve assembly. A vapor vent conduit provides fuel tank vapor pressure to one side of a diaphragm and, through a restricted orifice, to the other side of the diaphragm, the other side being further connected by a recirculation conduit to the tank filler neck. When a gas cap closes the filler neck from the atmosphere, the orifice allows pressure to equalize across the diaphragm; and a spring biases the diaphragm to close a vapor vent valve. When the gas cap is removed, atmospheric pressure is provided through the recirculation conduit to the other side of the diaphragm, which can then be activated by a relatively small differential pressure to open the vent for relatively unrestricted vapor flow from the tank to a canister during refueling, with a small portion of the vapor recirculated in a controlled flow through the orifice and recirculation conduit to the filler neck for entrainment in incoming liquid fuel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.