Device for controlling the idling operation of an internal combustion engine.

摘要

A device for controlling the idling operation of an internal combustion engine is disclosed which can prevent any abnormal increase in RPMs during the idling of the engine even if a control unit outputs an abnormal signal to an actuator so as to cause a throttle valve to excessively open from a preset position. The idling-operation controlling device comprises: an actuator for controlling the opening degree of a throttle valve during the engine idling operation; an actuator position sensor for sensing the operating position of the actuator; a control unit adapted to receive the output signals from an engine RPM sensor, a water temperature sensor which senses the temperature of engine cooling water and the actuator position sensor to control the operation of the actuator in a manner such that the opening degree of the throttle valve is adjusted to an appropriate level thereby to control the RPMs of the engine during idling to a predetermined value in response to the sensed temperature of the cooling water; a position limiter adapted to output a limit signal to the control unit when the output signal from the actuator position sensor exceeds a preset upper limit which corresponds to the sensed temperature of the cooling water; and an actuator-stopping element adapted to stop the operation of the actuator when the limit signal is input from the position limiter to the control unit and when the control unit outputs to the actuator an output signal which operates the actuator in a direction to increase the engine RPMs. In another embodiment, the actuator-stopping element is replaced by a actuator-limiting element which not only performs the same operation as that of the actuator-stopping element but also operates the actuator in a direction to decrease the engine RPMs to a prescribed level.