Heat pump cycle having internal heat exchanger

A heat pump cycle capable of switching between cooling operation and heating operation, which is used for a vehicle air conditioner, comprising:

• a compressor for sucking and compressing a refrigerant;
• an outdoor heat exchanger for performing a heat exchange between outdoor air and the refrigerant;
• an indoor heat exchanger for performing a heat exchange between indoor air blowing into a vehicle compartment and the refrigerant;
• an accumulator for separating the refrigerant into a gas phase refrigerant and a liquid phase refrigerant containing lubricating oil, said accumulator including an oil return hole for extracting the liquid phase refrigerant containing lubricating oil, and said accumulator allowing the liquid phase refrigerant containing the lubricating oil extracted from said oil return hole and the separated gas phase refrigerant to flow out to said compressor;
• an internal heat exchanger for performing a heat exchange between a discharge side refrigerant flowing between said indoor heat exchanger and said outdoor heat exchanger and a suction side refrigerant flowing out of said accumulator;
• a first pressure reducing unit provided in a refrigerant passage allowing said indoor heat exchanger to communicate with said internal heat exchanger, said first pressure reducing unit decompressing the refrigerant flowing out of said internal heat exchanger at a time of the cooling operation to cool the air blowing into said vehicle compartment;
• and
• a second pressure reducing unit provided in a refrigerant passage allowing said outdoor heat exchanger to communicate with said internal heat exchanger, said second pressure reducing unit decompressing the refrigerant flowing from said internal heat exchanger to said outdoor heat exchanger at a time of the heating operation to heat the air blowing into said vehicle compartment through said indoor heat exchanger.