Apparatus and method for controlling cooling fan of vehicle

Abstract

An apparatus and a method for controlling a cooling fan of a vehicle are capable of preventing a fan motor from being damaged by locking the fan motor in cold weather conditions. The apparatus includes: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, where the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.

What is claimed is: 
     
         1 . An apparatus for controlling a cooling fan of a vehicle, the cooling fan being installed in an engine compartment of the vehicle, comprising:
 a fan motor driving the cooling fan; and   a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor,   wherein the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.   
     
     
         2 . The apparatus of  claim 1 , wherein:
 the controller confirms a first change rate of the air conditioner refrigerant pressure for a first measurement time, operates the cooling fan through the fan motor by providing the operation signal to the fan motor for a second measurement time, confirms a second change rate of the air conditioner refrigerant pressure for the second measurement time, and stops the operation of the cooling fan depending on the first change rate and the second change rate.   
     
     
         3 . The apparatus of  claim 2 , wherein:
 the controller calculates a comparison value on the basis of the first change rate and the second change rate, decides whether or not the comparison value is less than or equal to a decision reference, and stops the operation of the cooling fan in the case in which the comparison value is not maintained for a duration in a state in which the comparison value is less than or equal to the decision reference.   
     
     
         4 . The apparatus of  claim 1 , further comprising:
 a state detector including at least one of: an intake air temperature measurer measuring the intake air temperature, a coolant measurer measuring a coolant temperature, a speed measurer measuring a vehicle speed, and a pressure measurer measuring the air conditioner refrigerant pressure.   
     
     
         5 . The apparatus of  claim 1 , wherein:
 the controller provides the operation signal to the fan motor and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time, when a compressor is operated and a vehicle speed is 0.   
     
     
         6 . The apparatus of  claim 1 , wherein:
 the controller turns off a compressor when the intake air temperature is not present within the predetermined temperature, and operates the cooling fan when a coolant temperature is greater than or equal to a reference temperature in a state in which the controller turns off an air conditioner switch.   
     
     
         7 . A method for controlling a cooling fan of a vehicle, comprising:
 confirming, by a controller, an ignition-off time for which an ignition was turned off when the ignition is turned on;   deciding, by the controller, whether or not the ignition-off time exceeds a decision-possible time;   deciding, by the controller, whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and   locking a fan motor, by the controller, depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature.   
     
     
         8 . The method of  claim 7 , wherein the locking of the fan motor includes:
 confirming a first change rate of the air conditioner refrigerant pressure for a first measurement time;   operating the cooling fan for a second measurement time;   confirming a second change rate of the air conditioner refrigerant pressure for the second measurement time; and   stopping the operation of the cooling fan depending on the first change rate and the second change rate.   
     
     
         9 . The method of  claim 8 , wherein the stopping of the operation of the cooling fan depending on the first change rate and the second change rate includes:
 calculating a comparison value on the basis of the first change rate and the second change rate;   deciding whether or not the comparison value is less than or equal to a decision reference;   deciding whether or not the comparison value is maintained for a duration in a state in which the comparison value is less than or equal to the decision reference; and   stopping the operation of the cooling fan in the case in which the comparison value is not maintained for the duration.   
     
     
         10 . The method of  claim 9 , wherein the comparison value is calculated through an equation:
     C=B/A      where C is the comparison value, A is the first change rate, and B is the second change rate.   
     
     
         11 . The method of  claim 7 , wherein the locking of the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time when the intake air temperature is present within the predetermined temperature includes:
 deciding whether or not a compressor is operated when the intake air temperature is present within the predetermined temperature;   deciding whether or not a vehicle speed is 0 when the compressor is operated; and   locking the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time when the vehicle speed is 0.   
     
     
         12 . The method of  claim 7 , wherein the deciding of whether or not the intake air temperature is present within the predetermined temperature includes:
 deciding whether or not the intake air temperature is less than a maximum temperature; and   deciding whether or not the intake air temperature is greater than or equal to a minimum temperature when the intake air temperature is less than the maximum temperature.   
     
     
         13 . The method of  claim 7 , wherein, after the deciding of whether or not the intake air temperature is present within the predetermined temperature, further comprising:
 turning off a compressor when the intake air temperature is not present within the predetermined temperature;   measuring a coolant temperature in a state in which an air conditioner switch is turned off; and   operating the cooling fan when the coolant temperature is greater than or equal to a reference temperature.   
     
     
         14 . A non-transitory computer readable medium containing program instructions executed by a processor, the computer readable medium comprising:
 program instructions that confirm an ignition-off time for which an ignition was turned off when the ignition is turned on;   program instructions that decide whether or not the ignition-off time exceeds a decision-possible time;   program instructions that decide whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and   program instructions that lock a fan motor depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature.