JPS5718511A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To ensure temperature control, by providing a room temperature setting means and a room temperature detector means to make the gradient of the opening degree characteristic curve of an air mix door smaller when the difference between the temperature of a room and a set level is not larger than a prescribed value than when the difference is smaller than the value. CONSTITUTION:An air conditioning control circuit comprising a room temperature sensor 31, a room temperature setting means 32, an air conditioning switch 33, etc. is provided. Ajudgement circuit 34 calculates the temperature difference signal between the set signal of the room temperature setting means 32 and the room temperature signal of the room temperature sensor 31 and judges whether the temperature difference signal is larger or smaller than the output signal of the air conditioning switch 33. When the temperature difference is larger than a prescribed value B, an air mix door 38 is entirely closed or opened. When the temperature difference is between the prescribed value B and a set value C, air conditioning is controlled in a pattern (b). When the temperature difference is not larger than a set value C, the air conditioning is controlled in another pattern (a). According to this constitution, the temperature of a room can be caused to rapidly approach a set level. When and after the temperature has come to the vicinity of the set level, the temperature can be controlled to be stable. The room temperature can thus be surely controlled.