AIR CONDITIONING SYSTEM FOR AUTOMOTIVE VEHICLES

The present invention relates to an air conditioning system for automotive vehicles. The present invention is to solve a hunting phenomenon of that an expansion valve is varied at the same time when the variable rate of change in a compressor is increased, the difficulty of a refrigerant flow control, and cooling performance deterioration in the interior of a vehicle. The present invention in order to achieve the purpose comprises the compressor, a condenser, the expansion valve, and an evaporator, wherein the compressor varies the discharge amount of a refrigerant according to a cooling load in the interior of the vehicle and the expansion valve varies the inflow amount of the refrigerant of the evaporator by varying the opening amount in a throttling passage according to the degree of superheat of the refrigerant. When the rate of change per time of the discharge amount of the refrigerant to be discharged in the compressor is risen more than the predetermined rate of change of the discharge amount of the standard refrigerant, The air conditioning system for automotive vehicles includes a control unit which forcibly controls the opening degree of the expansion valve while entering an anti-hunting mode. The control unit controls the opening degree of the expansion valve when the control unit enters the anti-hunting mode and controls the expansion valve in order to regularly maintain the opening degree of an entering point of the anti-hunting mode.