| 摘要 |
PURPOSE:To enhance the stability and efficiency of supply of hot air, by providing such an arrangement that the heat quantity of a heat-exchanger is obtained in accordance with signals from an engine cooling water flow adjusting valve, a water temperature sensor and an engine rotational speed sensor, and the flow rate of cooling air is controlled in accordance with the thus obtained heat quantity. CONSTITUTION:A control circuit calculates the flow rate of engine cooling water passing through a heat-exchanger 6 in accordance with signals from an engine rotational speed sensor 2 and the opening degree of an engine cooling water control valve 5, and also calculates the heat quantity of the heat-exchanger in accordance with the thus obtained flow rate and a signal from an engine cooling water temperature 4. Meanwhile, a necessary heat-exchanging amount is determined in accordance with a desired blow-off air temperature, the drive voltage of a blower motor 8 and the blow-in air temperature 7 of the heat-exchanger. Further, with the result of comparison between the necessary heat exchanging amount and the heat quantity of the heat- exchanger, the opening degree of the engine cooling water control valve 5 is controlled. With this arrangement it is possible to stabilize the supply of hot air and to enhance the efficiency thereof. |
