Method of and apparatus for controlling the idling speed of an engine
AssigneeToyota Jidosha Kogyo Kabushiki Kaisha
InventorsHiroshi Itoh, Mamoru Kobashi
Life of this patent
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Abstract
An engine includes a main intake passage having a throttle valve therein. A bypass passage branches off from the main intake passage upstream of the throttle valve and connects again to the main intake passage downstream of the throttle valve. A flow control valve, actuated by a step motor, is arranged in the bypass passage. When the speed difference between the desired idling speed and the actual idling speed is higher than 20 r.p.m., the step motor is rotated in a direction wherein the actual idling speed approaches the desired speed. Contrary to this, when the above-mentioned speed difference is lower than 20 r.p.m., the step motor remains stationary.
Claims4
Apparatus for controlling the idling speed of an engine, said engine including a main intake passage having a throttle valve disposed therein, the apparatus comprising:
- a bypass passage having first and second ends connected to the main intake passage upstream and downstream of the throttle valve, respectively;
- means for controlling the amount of air passing through the bypass passage;
- means for measuring the actual idling speed of the engine;
- means for calculating the speed difference between said actual idling speed and a predetermined desired speed, said calculating means calculating said speed difference after a predetermined waiting time has elapsed since the previous calculation, said waiting time being increased when said measuring means initially measures said actual idling speed after the operating condition of the engine is changed to an idling operating condition;
- and
- means for adjusting the controlling means to cause actual idling speed to approach the desired speed only when speed difference exceeds a predetermined value.
Dependencies are inferred from the claim text.