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:
Oct. 28, 2003
Filed:
May. 30, 2002
Hirotada Muraki, Brussels, BE;
Masahiro Arai, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
In a variable valve timing system for an internal combustion engine, a soft-landing revertive control that an electromagnetic brake is de-energized and then an angular position of a camshaft relative to a crankshaft returns to an initial position is performed by a combination of a feedback control and a feedforward control. During the revertive control, the feedback control is executed in such a manner as to temporarily halt the angular phase of the camshaft at a predetermined position, which is phase-changed by a predetermined phase angle from the initial position. After the feedback control, the operating mode is switched to a feedforward control, so as to return the angular phase of the camshaft from the predetermined position to the initial position by changing a controlled quantity or a control-signal duty cycle value for the electromagnetic brake with a predetermined time rate of change.