| 摘要 |
PURPOSE:To prevent noise of a cooling fan for a vehicle engine from abruptly increasing, by determining a voltage applied to a fan motor in accordance with the temperature of the outside air, the temperature of cooling water, the speed of a vehicle, the rotational speed of an engine, the temperature of exhaust gas, the opening degree of a throttle valve. CONSTITUTION:A computing device 4 receives signals from an outside temperature sensor 1, a vehicle speed sensor 2, a cooling water temperature sensor 3, an engine rotational speed sensor 18, an exhaust gas temperature sensor 19 and a throttle valve opening degree sensor 20, and determines a voltage V to be applied to a fan motor 6, which is delivered to a motor control device 5. Further, when the thus determined voltage V exceeds about 1 voltage, the motor 6 is rotated at a fan rotational speed in accordance with the voltage V. Meanwhile, when the voltage V is less than about 1 voltage, or when it is less than about -0.5 voltage, the fan 7 is stopped, but when it exceeds -0.5 voltage the condition until then is sustained. With this arrangement it is possible to prevent the rotational speed from increasing and to restrain noise. |
