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:
Nov. 10, 1998
Filed:
Aug. 14, 1996
Ekkehard Schrey, Aachen, DE;
FEV Motorentechnik GmbH & Co KG, Aachen, DE;
Abstract
A method is provided for detecting play between a cylinder valve of a piston engine and an electromagnetic actuator that actuates the cylinder valve. The electromagnet has a closing electromagnet and an opening electromagnet, two restoring springs and an armature which is guided to be movable back and forth between the two electromagnets, in each case counter to a force of a respective one of the restoring springs for acting upon the cylinder valve. With the armature held at one of the electromagnets by a holding current I.sub.H, a time interval t.sub.H after turnoff of the holding current I.sub.H at the holding electromagnet until the arrival of the armature at the other one of the electromagnets is measured, and the valve play is calculated by subtracting from the time interval t.sub.H a motion time t.sub.B predetermined by the spring-mass system, comprising the armature, valve body and restoring springs, and a sticking time t.sub.K during which the armature remains at the holding electromagnet after cutoff of the holding current.