Patent ID: 7891204

Claim:
A refrigeration cycle device for a vehicle, comprising: a refrigeration cycle that includes a capacity-variable compressor driven by an engine mounted on the vehicle and having a capacity varying portion configured to vary a refrigerant discharge capacity discharged from the compressor, and an evaporator coupled to a refrigerant suction side of the compressor and for cooling air to be blown into a compartment by evaporating a low-pressure refrigerant; means for calculating a preset suction pressure that serves as a target value of a refrigerant suction pressure of the compressor and for controlling the refrigerant discharge capacity of the compressor by operating the capacity varying portion such that the refrigerant suction pressure approaches the preset suction pressure; a thermal load detection portion configured to detect a thermal load of the refrigeration cycle; a refrigerant flow amount detection portion configured to detect a flow amount of refrigerant circulating through the refrigeration cycle; means for estimating the refrigerant suction pressure of the compressor based on the thermal load detected by the thermal load detection portion and on the flow amount detected by the refrigerant flow amount detection portion, the estimating means being in communication with the calculating means; means for detecting a load condition exerted on the engine; and means for determining whether the engine is at a high load condition based on the load condition detected by the detecting means; wherein the estimating estimation means estimates an estimated suction pressure after the determining means determines that the engine is at the high load condition; and the calculating means calculates the preset suction pressure based on the estimated suction pressure, and controls the refrigerant discharge capacity of the compressor such that the suction pressure of the compressor becomes the preset suction pressure.