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:
Jul. 18, 2017
Filed:
Sep. 30, 2014
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Kentaro Mikawa, Isesaki, JP;
Naoki Okamoto, Isesaki, JP;
HITACHI AUTOMOTIVE SYSTEMS, LTD., Hitachinaka-Shi, JP;
Abstract
The present invention relates to a control device and a control method for a variable valve timing mechanism that changes a valve timing by adjusting a rotational speed of a motor. The control device detects a phase angle RAbased on an output of a crank angle sensor and an output of a cam angle sensor and calculates a change amount ΔRA of a rotational phase based on a difference between a rotation amount of a sprocket and a rotation amount of the motor. The control device stops calculating change amount ΔRA when a failure occurs in a motor rotation angle sensor. When a failure occurs in one of the crank angle sensor or the cam angle sensor, the control device stops calculating phase angle RAand calculates change amount ΔRA using a normal one of the sensors and the motor rotation angle sensor.