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. 29, 2004
Filed:
Feb. 27, 2003
Shinya Kondou, Susono, JP;
Hiroyasu Koyama, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
The invention controls the opening of an oil control valve (OCV), which controls the operation of a variable valve timing mechanism in an internal combustion engine, according to a duty ratio of a driving pulse signal. An electronic control unit (ECU) performs feedback control on a duty ratio DR of the driving pulse signal during ordinary operation based on a target value and an actual value of the valve timing. When the oil temperature is low (i.e., when the operating oil viscosity is high), the ECU controls the valve timing of the engine by repeating an inching operation that maintains the duty ratio DR of the signal at a large value (i.e., 0% or 100%) for a predetermined hold time so as to operate the variable valve timing mechanism, and then maintaining the duty ratio DR of the signal at a value (50%) that does not operate the variable valve timing mechanism.