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:
Jun. 14, 2011
Filed:
Aug. 29, 2007
Kazuhiro Ichimoto, Nishikamo-gun, JP;
Makoto Yamazaki, Gotenba, JP;
Tsukasa Abe, Gotenba, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
A variable valve timing system changes a valve phase by reducing an operation amount of an actuator at a speed reduction ratio that varies depending on a phase region. When the valve phase is outside a region in which the ratio of the amount of change in the phase with respect to the operation amount of the actuator is low, namely a high speed reduction ratio, the actuator may be operated due to, for example, a reaction force applied to a camshaft, and an undesirable valve phase change may result. Accordingly, when an engine stop command is possibly issued, the target phase value is restricted to a region more delayed than a phase restriction value set in consideration of the amount by which the valve timing can be changed from when an engine stop command is issued until when the engine is stopped.