Control device for motor fan of vehicle

A control device for a motor fan of a vehicle, which controls a motor fan by duty ratio control to cool a radiator for engine coolant and a condenser for air conditioner refrigerant, comprising:

• a first command value calculation section which calculates a first command value of duty ratio according to refrigerant pressure;
• a second command value calculation section which calculates a second command value of duty ratio according to coolant temperature;
• a first target value setting section which sets the greater of the first command value and the second command value as a first target value of duty ratio;
• a second target value setting section which calculates a total torque of a torque of an alternator and a torque of a compressor, and sets a duty ratio for which the total torque becomes a minimum as a second target value;
• and
• a duty ratio determination section which sets the greater of the first target value and the second target value as a final duty ratio, wherein
• the second target value setting section corrects the calculated total torque of the torque of the alternator and the torque of the compressor based upon a rotational speed of a blower fan motor, and sets a duty ratio for which the corrected total torque becomes minimum as the second target value.

A control device for a motor fan of a vehicle, comprising:

• an engine;
• an alternator which is driven by the engine;
• an air conditioning device of which a compressor is driven by the engine;
• an electrically driven motor fan which is operated by receiving supply of electrical power generated by the alternator, and which cools the air conditioning device;
• a discharge pressure detection section which detects a discharge pressure of the compressor;
• a target discharge pressure setting section which sets a target discharge pressure of the compressor with respect to a cooling performance which is required from the air conditioning device, so that a total of a drive load of the compressor and a drive load of the alternator for obtaining electrical power for operating the electrically driven motor fan becomes a minimum;
• and
• a motor fan control section which controls an operation of the electrically driven motor fan so that the discharge pressure of the compressor becomes equal to the target discharge pressure.

A control method for a motor fan of a vehicle, which controls the motor fan to cool a radiator for engine coolant and a condenser for air conditioner refrigerant, comprising:

• calculating a first command value for control of the motor fan according to refrigerant pressure;
• calculating a second command value for control of the motor fan according to coolant temperature;
• setting the greater of the first command value and the second command value as a first target value;
• obtaining a second target value for control of the motor fan which corresponds to a total torque which is smaller than a total torque of a torque of an alternator and a torque of a compressor corresponding to the first target value;
• and
• controlling the motor fan according to the second target value, wherein
• the total torque of the torque of the alternator and the torque of the compressor is corrected based upon a predetermined condition when obtaining the total torque of the torque of the alternator and the torque of the compressor.

A control method for a motor fan of a vehicle which controls the motor fan to cool an air conditioning device of which a compressor is driven by an engine, comprising:

• detecting a discharge pressure of the compressor;
• setting a target discharge pressure of the compressor with respect to a cooling performance which is required from the air conditioning device, so that a total of a drive load of the compressor and a drive load of an alternator for obtaining electrical power for operating the motor fan becomes a minimum;
• and
• controlling an operation of the motor fan so that the discharge pressure of the compressor becomes equal to the target discharge pressure.

A control device for a motor fan of a vehicle, which controls the motor fan to cool a radiator for engine coolant and a condenser for air conditioner refrigerant, comprising:

• a first command value calculation means for calculating a first command value for control of the motor fan according to refrigerant pressure;
• a second command value calculation means for calculating a second command value for control of the motor fan according to coolant temperature;
• a first target value setting means for setting the greater of the first command value and the second command value as a first target value;
• a second target value setting means for obtaining a second target value for control of the motor fan which corresponds to a total torque which is smaller than a total torque of a torque of an alternator and a torque of a compressor corresponding to the first target value;
• and
• a control means for controlling the motor fan according to the second target value, wherein
• the second target value setting means corrects the total torque of the torque of the alternator and the torque of the compressor based upon a predetermined condition when obtaining the total torque of the torque of the alternator and the torque of the compressor.

A control device for a motor fan of a vehicle, comprising:

• an engine;
• an alternator which is driven by the engine;
• an air conditioning device of which a compressor is driven by the engine;
• an electrically driven motor fan which is operated by receiving supply of electrical power generated by the alternator, and which cools the air conditioning device;
• a discharge pressure detection means for detecting a discharge pressure of the compressor;
• a target discharge pressure setting means for setting a target discharge pressure of the compressor with respect to a cooling performance which is required from the air conditioning device, so that a total of a drive load of the compressor and a drive load of the alternator for obtaining electrical power for operating the electrically driven motor fan becomes a minimum;
• and
• a motor fan control means for controlling an operation of the electrically driven motor fan so that the discharge pressure of the compressor becomes equal to the target discharge pressure.