Failure diagnosis apparatus for evaporative purge system
US5878728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Jun 6, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0809
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A back-pressure chamber of a tank internal pressure regulating valve and a canister are connected to each other by a communicating passage. During purging, since the negative pressure in an evaporative purge system is introduced into the back-pressure chamber, the valve opening pressure setting of the tank internal pressure regulating valve is lowered. As purge-cutting is started, the internal pressure of the canister instantly rises to the valve opening pressure of an air intake valve, thereby increasing the pressure introduced into the back-pressure chamber. Consequently, the valve opening pressure setting of the tank internal pressure regulating valve rises, thereby suppressing the valve opening operation. Thus, diagnosis is prevented from becoming erroneous as the pressure regulating valve in the evaporative purge system opens during the failure diagnosis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.