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:
Mar. 01, 2016
Filed:
Feb. 01, 2012
Martin Brandt, Wörth a.d. Donau, DE;
Martin Brandt, Wörth a.d. Donau, DE;
CONTINENTAL AUTOMOTIVE GMBH, Hannover, DE;
Abstract
An injection device for an internal combustion engine includes a piezo actuator for moving a valve piston, and a control unit for actuating the piezo actuator. The control unit supplies electrical pulses having different pulse energy to the piezo actuator and determines a return stroke between the piezo actuator and valve piston or a time delay caused by the return stroke. The control unit selects the pulse energies such that a maximum excursion of a movement of the piezo actuator caused by at least one pulse is smaller than the return stroke, whereas a maximum excursion of a piezo actuator movement caused by another pulse(s) is greater than the return stroke, after each of the pulses detects a frequency spectrum of a voltage signal at the piezo actuator during the movement caused by the respective pulse, and determines the return stroke or time delay based on these frequency spectra.