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.

Date of Patent:
Jun. 14, 1988

Filed:

Jul. 01, 1986
Applicant:
Inventors:

Hiroshi Hasebe, Hatogaya, JP;

Masahiko Asakura, Tokorozawa, JP;

Michio Sakaino, Fujimi, JP;

Yukio Miyashita, Hannou, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02N / ;
U.S. Cl.
CPC ...
123339 ; 123352 ;
Abstract

An idling speed control system for controlling idling rotational speed of an internal combustion engine. A vacuum-operated actuator having a diaphragm defining a vacuum chamber controls opening and closing of a throttle valve in an intake passage of the engine in response to first and second control pressures supplied from a change-over control valve to the vacuum chamber. An electronic control unit generates an on-off control pulse signal having a period corresponding to the rotational speed of the engine, one of on-period and off-period of the on-off control pulse signal having a predetermined constant value, and supplies the change-over control valve with the on-off control pulse signal, in response to which the change-over control valve supplies the vacuum chamber of the vacuum-operated actuator, selectively, with the first control pressure and the second control pressure, determines the engine rotational speed and a rate of decrease in the engine rotational speed, and halts the control for a predetermined period of time when the determined engine rotational speed falls within a predetermined range and at the same time the determined rate of decrease in the engine rotational speeds falls within a predetermined range.


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