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:
Dec. 30, 1997
Filed:
Dec. 20, 1996
Yasuo Sagisaka, Komaki, JP;
Yoshihiko Hirata, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
To appropriately detect malfunction of an air quantity adjusting valve in any type of case, an electronic control type throttle valve is disposed in an air intake pipe of an engine. An ISC valve which is duty controlled by an ECU is disposed in a bypass passage which bypasses the throttle valve. A CPU within the ECU establishes a drive duty ratio of the ISC valve to control engine speed in a target speed region during idling of the engine. Additionally, in a case where the drive duty ratio exceeds a predetermined control range (0 to 100%), the CPU controls idle speed by the throttle valve. Accordingly, in a case where throttle aperture is larger than a predetermined value TAH, or in a case where throttle aperture is smaller than a predetermined value TAL (where TAH>TAL), the CPU determines that an opening side malfunction or a closing side malfunction has occurred in the ISC valve.