VEHICULAR AIR-CONDITIONER

PROBLEM TO BE SOLVED: To improve on the oil circulation fault to a compressor unit 34 under a cold weather. SOLUTION: An air conditioner ECU 50 corrects a temporary IVO from an outside temperature and time elapsed since the startup of the compressor unit 34, for calculating a true IVO (S28 to S31). The air conditioner ECU 50 is so designed as to make greater the value of incremental rotation speed, that is, Δfrs value, correcting the temporary IVO, as the length of time elapsed since the startup of the compressor unit 34 becomes longer, under the outside temperature being equal to or below a prescribed temperature. This means that, when the outside temperature is low, being equal to or below a prescribed temperature, so that oil is brought to come under a condition that it becomes easy to dwell, the rotation speed of the compressor unit 34 is to be corrected to a higher one even if a required capacity is fulfilled. The correction, for certain, is to be made for a higher rotation speed, the longer the time has elapsed since the startup of the compressor unit 34. This enables an increase in the quantity of circulation of coolant so that oil which is easy to dwell within the circulation cycle is circulated into the compressor unit 34, by which poor-lubrication of the compressor unit 34 under a cold weather can be prevented. COPYRIGHT: (C)2009,JPO&INPIT