PURPOSE: To save power by controlling cooling performance, in an air conditioner for a vehicle such as a bus, by a method wherein the amount of loss of the pressure is controlled, by operating a control valve between a compressor and an evaporator by an electronic circuit.
CONSTITUTION: When the valve of a temperature setter 29 is set low, and detected values of an outside-air temperature sensor 9 and a room temperature sensor 10 are both high, their compound resistance comes to the minimum, and a controller 36 puts out the maximum number of pulse, to bring a control valve between a compressor and an evaporator to its-maximum degrees of opening. When the temperature of a room temperature sensor 10 is dropped and the resistance value is increased, the compound resistance is also increased, and the opening of a control valve is decreased according to the lowering of a room temperature, so that the effectiveness of refrigerant is decreased. When the room temperature is further decreased, the operation of a compressor 1 is stopped. The non-stage performance control of air conditioner by the amount of loss of the pressure as mentioned above can be attained by decreasing the feeding amount of refrigerant to a compressor, as a result, the driving power can be decreased.
KOKUBO NAOCHIKA
KOSASA TETSUO
