| 摘要 |
PURPOSE:To prevent overheating of an engine due to failure of a fan control circuit, by controlling that the device does not turn the fan off until the temperature detection means detect engine temperature drop in an on-off control device controlling a cooling fan in response to the engine temperature. CONSTITUTION:A motor 27, which drives a fan of engine radiator, is connected to a relay 15 controlled by a thermal switch 1 which detects temperature of cooling water. Also, a relay 5, having a normally shut contact 9, is connected to the thermal switch 1, and the contact 9 is connected to the motor 27 through a diode 11. When the temperature of cooling water is high, the contact B of the thermal switch 1 shuts, the relay 15 shuts and the motor 27 is driven, and when the temperature is low, the contact A shuts and the motor is stopped. Since the relay 15 is self-maintained through the diode 11, the motor 27 is driven even if the switch 1 fails, and overheating of the engine is prevented. |
