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:
Oct. 01, 2002
Filed:
Jan. 11, 2000
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01L 3/26 ; G01M 1/900 ;
U.S. Cl.
CPC ...
G01L 3/26 ; G01M 1/900 ;
Abstract
By employing command value signals for controlling the opening timing of an exhaust valve or an intake valve and means for measuring flow rates of an intake air of a flow direction which flows through an intake manifold of an internal combustion engine, an air flow rate corresponding to the command value signal is measured. A valve mechanism includes the intake valve and the exhaust valve for each cylinder of the internal combustion engine and is controlled by a valve control means for controlling the valve mechanism. A failure diagnosis of an operating status of the valve mechanism can be performed.