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:
Jan. 28, 1992
Filed:
Dec. 10, 1990
Bor-Dong Chen, Dearborn, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
An engine idle speed control (ISC) method includes fully opening an idle speed control valve during an engine crank mode and opening the idle speed control valve to a fixed position during a diagnostic mode. The normal idle speed control mode includes selecting an open-loop idle speed control mode or a closed-loop idle speed control mode as a function of dashpot preposition, dashpot control, Pre-RPM control, RPM control, and RPM lockout protection. In the open-loop idle speed control, the duty cycle is the sum of a base duty cycle, a dashpot action adder, an engine coolant temperature compensation adder, a time-since-engine-start compensation adder, and other duty cycle adders for additional loads, such as air-conditioner. In the closed-loop idle speed control, the duty cycle is adjusted at the proper time and with an appropriate amount to maintain the idling speed at the desired speed.