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:
Feb. 27, 1996
Filed:
Sep. 06, 1994
Nobuhisa Ohkawa, Toyota, JP;
Tadahisa Naganawa, Toyota, JP;
Kouji Endou, Mizunami, JP;
Senji Kato, Aichi, JP;
Shigeru Sone, Toyota, JP;
Atsushi Goto, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A varying mechanism (VVT) for continuously varying the valve timing of an intake valve in a predetermined range is provided on a cam shaft in an engine. By controlling the VVT, the valve overlap period of the intake valve and an exhaust valve is continuously varied in a predetermined range, thus adjusting the amount of the internal EGR in combustion chambers. When determining that the operational load of the engine is small and intermediate based on the value of a manifold pressure, an electronic control unit (ECU) computes a target value for advancing the valve timing with respect to the rotational phase of a crankshaft based on a throttle angle, an engine speed, etc. The ECU also computes a limit value to restrict the target value in accordance with the value of the manifold pressure. When the target value is smaller than the limit value, the ECU controls the VVT based on the target value. When the target value is greater than the limit value, the ECU replaces the limit value with target value and controls the VVT based on this target value.