Idle rotational speed control device in engine

Abstract

Abstract PURPOSE:To make it possible to prevent engine stalls, by supplying a predetermined volume intake-air in addition to a volume of intake air set under feed- back control when the rotational speed of an engine drops down to a first set rotational speed below a desired idle rotational speed. CONSTITUTION:When an engine control device 13 determines that the operation of an engine is in an idle running range in accordance with signals from a rotational speed sensor 14 and a throttle opening degree sensor 15, an idle control section 132 adjusts the volume of intake-air from a solenoid control valve 11 in accordance with a deviation from a desired idle rotational speed to carry out feed-back control. Under this condition, when the rotational speed of the engine drops down to a first set rotational speed which is below the desired idle rotational speed, a fast idle control section 133 delivers a signal having a predetermined duty ratio to the solenoid control valve 11 in addition to the adjustment to the volume of intake-air under feed-back control, to initiate the supply of intake-air in a predetermined volume. When the rotational speed of the engine increases up to a second set rotational speed above the first set rotational speed, the fast supply of intake-air is stopped, thereby it is possible to prevent the blow-off of the engine and engine stalls.

Inventors

• 👤 Masato Iwaki
• 👤 正人 岩城

Bibliographic Details