Diagnostic system for canister purge system
US5333590A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 26, 1993 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Apr 26, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/0606
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The present invention provides a system for detecting leaks in the evaporative emission control system utilized in automotive vehicles. Such control systems include a carbon filled canister having both a vent port and a fuel vapor port. The fuel vapor port, as well as a vapor line from the fuel tank, are connected through a purge valve to the intake manifold of the internal combustion engine. The present invention includes a vent valve which is fluidly connected with the canister vent port. An electronic control system closes both the vent valve and opens the purge valve thereby exposing the evaporative emission control system to the partial vacuum in the intake manifold. After a predetermined time period, the purge valve is closed thus entrapping the partial vacuum in the purge system while a pressure transducer thereafter monitors the partial vacuum in the purge system. Changes in the partial vacuum over a time period, after correction by extraneous factors such as temperature and fuel volume in the fuel tank, greater than a threshold amount indicates a leak in the evaporative emission system. When this occurs, the system generates a fault signal to alert the vehicle operator of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.