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:
Apr. 26, 2011
Filed:
Dec. 11, 2008
Dirk Hartmann, Stuttgart, DE;
Dirk Hartmann, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A method and a device for the diagnosis of at least one gas exchange valve of at least one cylinder of an internal combustion engine that is on the one hand reliable and on the other hand does without additional sensor equipment are described. In a first operating state of the internal combustion engine, at least one gas exchange valve of the at least one cylinder is activated. In a second operating state of the internal combustion engine, all the gas exchange valves of the at least one cylinder are deactivated and therewith closed in stationary fashion. Sound waves produced by the internal combustion engine are acquired. It is checked whether a significant change occurs in a quantity characterizing the acquired sound waves upon a transition from the first operating state to the second operating state. In this case, an erroneous opening of the at least one gas exchange valve is recognized.