Patent ID: 6948477

Claim:
An idle speed control device, for controlling rotational speed of an engine in an idling state to a target value, comprising: a bypass passage for bypassing a throttle valve; an idle control valve provided in the bypass passage; a throttle opening amount sensor for detecting throttle opening amount; and control means for controlling opening amount of the idling control valve; wherein the control means further comprises: means for determining whether the engine is in an idling state or a non-idling state; means for obtaining a target speed for engine rotational speed in the idling state; means for obtaining a target valve opening amount for the idling control valve in the non-idling state; feedback control means for controlling the idling control valve so that the engine rotation speed matches the target value in the idling state; valve opening amount maintaining means for, when shifting from the idling state to a non-idling state, maintaining the idling control valve at the opening amount at the time of feedback control until the throttle opening amount reaches a specified reference opening amount; and open loop control means for controlling the idling control valve to the target valve opening amount if the throttle opening amount reaches the specified reference opening amount in the non-idling state.