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:
May. 07, 1996
Filed:
Apr. 19, 1995
Akio Okamoto, Takahama, JP;
Hirohisa Kishi, Nagoya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
The idle speed control device according to the present invention controls a two-solenoid rotary type idle speed control valve properly even when one of the solenoids fails. When one of the solenoids fails, the device calculates the amount of bypass air from the amount of inlet air and the degree of opening of the throttle valve, and estimates the degree of opening of the idle speed control valve. If the degree of opening of the bypass valve is larger than that of the neutral valve position, the device sets the duty ratio of the control signal for driving the idle speed control valve at 0%, and if the degree of opening of the idle speed control valve is less than that of the neutral valve position, the device sets the duty ratio of the control signal at 100%. By this control, the two-solenoid rotary type idle speed control valve is maintained at neutral valve position without determining the type of the failure of the solenoids precisely.