| 摘要 |
PURPOSE:To enable the prevention of frosting and freezing in an evaporator without causing increased fuel consumption and discomfort by switching the revolutions of a compressor to the low speed level detecting the fin temperature or the like of the evaporator falling below the set value. CONSTITUTION:When the heat load is large with respect to the cooling capacity, the room temperature goes high, raising the fin temperature of an evaporator 10 up to a level higher than the set value. This is detected with a temperature sensor 15 to energize an electromagnetic clutch 5 at the high speed position with a temperature switch 16, causing a compressor 6 to rotate at a high speed. When the fin temperature of the evaporator 10 falls below the set value with the lowering of the room temperature of a vehicle, the energization is switched to the side of an electromagnetic clutch 19 causing the compressor 6 to rotate at the low speed. This allows the selection of capacity of the compressor 6 to match the heat load. When the fin temperature lowers below the set value with reduction in the heat load, the energization of the electromagnetic clutches 5 and 19 is halted to stop the compressor 6. |
