Vehicle air conditioning apparatus

A vehicle air conditioning apparatus comprising:

• a compressor configured to compress and discharge a refrigerant;
• a radiator provided in an air flow passage that allows air to be supplied to a vehicle interior to flow through and configured to release heat from the refrigerant;
• an indoor heat exchanger provided in the air flow passage in an upstream of air flow from the radiator and configured to absorb the heat into the refrigerant;
• an outdoor heat exchanger provided outside the vehicle and configured to release the heat from the refrigerant;
• and
• an air mix damper configured to be able to change a percentage of the air flowing through the air flow passage that is subjected to a heat exchange with the refrigerant flowing through the radiator, wherein:
• when a degree of an opening defined by movement of the air mix damper is increased, the percentage of the air subjected to the heat exchange with the refrigerant is increased;
• and
• the refrigerant discharged from the compressor releases the heat in the radiator and the outdoor heat exchanger while flowing first through the radiator, and next through the outdoor heat exchanger, and is decompressed by an expansion valve and absorbs the heat in the indoor heat exchanger, so that the air having been cooled in the indoor heat exchanger is heated in the radiator, and then supplied to the vehicle interior,
• the vehicle air conditioning apparatus further comprising:
• a refrigerant flow regulating valve provided in a refrigerant flow passage between the radiator and the outdoor heat exchanger and configured to regulate an amount of the refrigerant flowing through the refrigerant flow passage;
• a target air-blowing temperature calculation part configured to calculate a target air-blowing temperature that is a temperature of the air to be supplied to the vehicle interior required to ensure that the temperature of the vehicle interior is a preset temperature;
• a heated air temperature detection part configured to detect a temperature of the air after being heated in the radiator;
• a cooled air temperature detection part configured to detect a temperature of the air after being cooled in the indoor heat exchanger;
• an opening calculation part configured to calculate the opening of the air mix damper, based on the temperature calculated by the target air-blowing temperature calculation part, the temperature detected by the heated air temperature detection part and the temperature detected by the cooled air temperature detection part;
• a valve opening control part configured to control a valve opening of the refrigerant flow regulating valve such that the valve opening of the refrigerant flow regulating valve is smaller when the valve opening calculated by the opening calculation part is equal to or more than a predetermined value than when the valve opening calculated by the opening calculation part is smaller than the predetermined value;
• and
• an outlet switching part configured to switch a mode among a vent mode to blow the air flowing through the air flow passage toward a head of a passenger in the vehicle interior, a foot mode to blow the air toward feet of the passenger in the vehicle interior, and a bi-level mode to blow the air toward the head and the feet of the passenger in the vehicle interior,
• wherein the predetermined value used by the opening calculation part varies depending on the mode set by the outlet switching part, and
• wherein, the opening calculation part is configured to use 100% as the predetermined value, in response to the mode set by the outlet switching part being the vent mode or the mode set by the outlet switching part being the foot mode.