Method and arrangement for checking the operability of a tank-venting system
US5463998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1993 |
| Grant date | Nov 7, 1995 |
| Priority date | — |
| Expiry date | Oct 4, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0809
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method for checking the operability of a tank-venting system in a vehicle having an internal combustion engine, which tank-venting system has a tank with a tank-pressure sensor, an adsorption filter connected to the tank via a tank-connecting line, and a tank-venting valve which is connected to the adsorption filter via a valve line, in which system the adsorption filter has a venting line which can be closed with the aid of a shut-off valve, has the following steps: closing the shut-off valve; opening the tank-venting valve; determining the build-up gradient (p+) of the underpressure building up in the tank; closing the tank-venting valve; determining the decay gradient (p-) of the decaying underpressure in the tank; mathematically combining the build-up and decay gradients in a manner such that the influence of the fill level has as little effect as possible on the evaluation variable (Q) formed by means of the combination; and, comparing the value of the evaluation variable with a threshold value (Q.sub.-- SW) and evaluating the system as non-operative if the value of the evaluation variable and the threshold value fulfill a pregiven relationship.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.