Idling speed control system of an internal combustion engine

• US 4,611,560 A
• Filed: 12/07/1984
• Issued: 09/16/1986
• Est. Priority Date: 04/08/1983
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Miyazaki, Masaaki, Nakamura, Noboru, Kako, Hajime, Ishii, Mitsuaki, Kakinuma, Hideo
• Primary Examiner(s): Cox, Ronald B.
• Application Number:
  US06/681,855
• Time in Patent Office: 648 Days
• Field of Search: 290/40 R, 290/40 A, 290/40 B, 290/40 C, 290/51, 123/339
• US Class Current: 123/339.17
• CPC Class Codes: F02D 31/004 by controlling a throttle stop
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning

Abstract

The present invention is adapted for providing an idling speed control system of an internal combustion engine, which exhibits a good response for changes in an engine load, comprising: a throttle valve which controls the amount of intake air for the engine; an actuator which includes an electric motor for variably controlling the opening of the throttle valve; a rotation speed detector for detecting the rotation speed of the engine; an idling condition detector for detecting the idling condition of the engine; and a control, responsive to the detected output of the idling condition detector means, for generating feedback control pulses to intermittently drive said electric motor so that the detected rotation speed of the engine under the idling condition may converge into a target idling rotation speed while, responsive to the output of a detector that detects the operation condition of the engine load operated under the idling condition of the engine, or to the detected output of said rotation speed detector indicating that the detected rotation speed has dropped to an abnormally low rotation speed of the engine, for generating drive control pulses at a time independent of said feedback control pulses to drive said electric motor in a predetermined direction.

Claims

1. An idling speed control system of an internal combustion engine comprising:

a valve device which controls the amount of intake air for the engine;

an actuator which includes an electric motor for variably controlling the opening of said valve device;

rotation speed detector means for detecting the rotation speed of the engine;

idling condition detector means for detecting the idling condition of the engine;

feedback control means responsive to the detected output of said idling condition detector means for generating feedback control pulses to intermittently drive said electric motor so that said detected rotation speed of the engine under the idling condition may converge into a target idling rotation speed; and

control means responsive to the output of detector means that detects an abnormally low rotation speed of the engine detected by said rotation speed detector means for generating control pulses that do not overlap said feedback control pulses to drive said electric motor in a predetermined direction.

2. An idling speed control system of an internal combustion engine comprising:

a valve device which controls the amount of intake air for the engine;

an actuator which includes an electric motor for variably controlling the opening of said valve device;

rotation speed detector means for detecting the number of revolutions of the engine;

idling condition detector means for detecting the idling condition of the engine;

engine load condition detector means for detecting the operation condition of an engine load under the idling condition of said engine;

feedback control means responsive to the detected output of said idling condition detector means for generating feedback control pulses to intermittently drive said electric motor so as to converge said detected rotation speed of the engine under the idling condition into a target idling rotation speed;

first control means responsive to an operation condition of an engine load under the idling condition of the engine detected by said engine load condition detector means for generating drive control pulses at a time such that said drive pulses do not overlap said feedback control pulses to drive said electric motor in a predetermined direction; and

second control means for determining the time of the generation of said feedback control pulses relative to the generation of said drive control pulses such that said feedback control pulses are generated at a predetermined time from the generation of said drive control pulses.

4. An idling speed control system of an internal combustion engine according to claim 2, wherein the engine load comprises an air-conditioning apparatus.

3. An idling speed control system of an internal combustion engine comprising:

a valve device which controls the amount of intake air for the engine;

an actuator which includes an electric motor for variably controlling the opening of said valve device;

rotation speed detector means for detecting the rotation speed of the engine;

idling condition detector means for detecting the idling condition of the engine;

feedback control means responsive to the detected output of said idling condition detector means for generating feedback control pulses to intermittently drive said electric motor so as to converge said detected rotation speed of the engine under the idling condition into a target idling rotation speed;

first control means responsive to an abnormally low rotation speed of the engine detected by said rotation speed detector means for generating drive control pulses at a time such that said drive pulses do not overlap said feedback control pulses to drive said electric motor in a predetermined direction; and

second control means for determining the time of the generation of said feedback control pulses relative to the generation of said drive control pulses such that said feedback control pulses are generated at a predetermined hold time from the generation of said drive control pulses.