Patent ID: 6804970
Filing Date: 2004-10-19
Classification: B60H

Abstract:
A method of controlling a refrigeration cycle of an automotive air conditioner,characterized by estimating a differential pressure between a high pressure-side refrigerant pressure and a low pressure-side refrigerant pressure in the refrigeration cycle and a flow rate of refrigerant flowing therethrough, based on a first external electric signal for controlling the differential pressure between the high pressure-side refrigerant pressure and the low pressure-side refrigerant pressure in the refrigeration cycle or the flow rate of refrigerant flowing therethrough and a second external electric signal for controlling a size of a refrigerant passage in the refrigeration cycle, and estimating a compressor variable displacement ratio and driving torque of a compressor based on the estimated differential pressure and flow rate of refrigerant and an engine rotational speed; and controlling the first external electric signal and the second external electric signal such that refrigerating capacity of the refrigeration cycle is maximized when the automotive air conditioner is started, efficiency of the refrigeration cycle is maximized when the vehicle is in a steady traveling condition, and the driving torque of the compressor is reduced when the vehicle is in an accelerating condition.