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. 18, 2002
Filed:
Feb. 26, 2001
Kazuhisa Mikame, Nagoya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A camshaft provided with three-dimensional cams is connected at its one end to a valve lift-varying actuator. By the valve lift-varying actuator or displacing the camshaft in the directions of an axis of the camshaft, the lift characteristic of intake valves set by the three-dimensional cams is variably controlled to a target amount of valve lift. The valve lift characteristic related to this control is detected as a detected amount of valve lift by a reference-purposed detected portion and a cam angle sensor. An apparatus and a method diagnoses abnormalities in the valve lift-varying actuator by, for example, evaluating whether the amount of change in the detected amount of valve lift is at most a predetermined value and the absolute value of a difference between the detected amount of valve lift and the target amount of valve lift is greater than a predetermined value.