Apparatus for detecting malfunction in evaporated fuel purge system used in internal combustion engine
US5295472A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1992 |
| Grant date | Mar 22, 1994 |
| Priority date | — |
| Expiry date | Dec 29, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0809
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A malfunction detecting apparatus for an evaporated fuel purge system includes a first control valve for controlling a flow of fuel vapor in a purge passage between a canister and an intake passage, a second control valve for controlling a flow of air from the atmosphere to the canister via an air inlet opening of the canister, a first control part for turning OFF the second control valve and for turning ON the first control valve during a first time period, so as to subject the purge passage, the canister, and a vapor passage to a negative pressure of the intake passage during the first time period, and a first discriminator for detecting whether or not a malfunction has occurred in the system, in accordance with a pressure change rate derived from pressures of the system sensed at a start of the first time period and at an end thereof. The apparatus further includes a second control part for detecting whether or not a pressure of the system reaches a prescribed negative pressure after it is detected that no malfunction has occurred in the system, and for turning OFF the first and second control valves during a second time period after the prescribed negative pressure is reached, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.