| 摘要 |
PURPOSE:To prevent drop of the idling speed of an internal-combustion engine caused by reduction in the density of air due to temperature rise of intake air during idling operation of the engine, by controlling operation of a control valve for controlling the quantity of intake air supplied to the engine according to the temperature of intake air. CONSTITUTION:An air passage 7 is formed in the manner of by-passing a throttle valve 2 that is connected to an intake pipe 6 of an internal-combustion engine 1, and a solenoid valve 3 for increaseing the quantity of intake air supplied to the engine 1 under the idling operation is provided in the air passage 7. Further, an intake-temperature sensor 5 is provided in the intake pipe 6, and an ECU4 increases the quantity of intake air by applying a driving signal to the solenoid valve 3 in response to the output signal of the sensor 5. That is, the ECU4 supplies the output signal of the sensor 5 to a CPU42 via an A/D converter 41, determines opening and closing of the solenoid valve 3 and applies driving signals to the solenoid valve 3 via a driving circuit 43. By thus opening and closing the air passage 7 by the solenoid valve 3, the idling speed of the engine is increased. |
