The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 29, 2013
Filed:
Dec. 18, 2009
Oliver Grunwald, Ingolstadt, DE;
Siegfried Meixner, Hofstetten, DE;
Peter Enders, Munich, DE;
Audi, AG, Ingolstadt, DE;
Abstract
The invention relates to a method for checking the function of a tank venting valve between the intake manifold of an internal combustion engine and a fuel tank or a fuel vapor reservoir in which the tank venting valve in operation of the internal combustion engine is opened several times and is closed again after a short opening time and in which during repeated opening and closing the time characteristic of a quantity which is dependent on the opening state of the tank venting valve is recorded. In order to enable a reliable function check of the tank venting valve even in the case of very small and/or time-shifted amplitudes of the quantity to be monitored, it is proposed, according to the invention, that the first derivative of the time characteristic of the quantity be evaluated.