초록 ▼

A control device for a compressor in an automotive air conditioning system is disclosed which includes a pressure sensor disposed on a conduit concerning an evaporator and the compressor for detecting a refrigerant pressure at an outlet side of the evaporator. A control unit compares a pressure chan

A control device for a compressor in an automotive air conditioning system is disclosed which includes a pressure sensor disposed on a conduit concerning an evaporator and the compressor for detecting a refrigerant pressure at an outlet side of the evaporator. A control unit compares a pressure change ratio based on the detected refrigerant pressures with a predetermined pressure change ratio and selects either one of two ranges of predetermined values in accordance with the compared results, and further compares the refrigerant pressure with the predetermined values, thereby controlling the operation of an electromagnetic clutch which is mounted on the compressor and the capacity of the compressor in accordance with the last mentioned compared results.

대표청구항 ▼

A device for controlling the capacity of a variable compressor having an evaporator, an electromagnetic clutch and compressor capacity changing means, said device comprising: pressure detector means operatively connected for detecting a refrigerant pressure at an outlet side of said evaporator to de

A device for controlling the capacity of a variable compressor having an evaporator, an electromagnetic clutch and compressor capacity changing means, said device comprising: pressure detector means operatively connected for detecting a refrigerant pressure at an outlet side of said evaporator to determine at least a first refrigerant pressure and a second refrigerant pressure; and control means for controlling said electromagnetic clutch and said capacity changing means, said control means including: first comparison means for comparing said first detected refrigerant pressure with said second detected refrigerant pressure and providing a first control signal when said first detected refrigerant pressure is greater than said second detected refrigerant pressure, wherein a pressure change ratio is calculated based on the comparison of said first and second detected refrigerant pressures and the presence of said first control signal, second comparison means for comparing one of said detected refrigerant pressures with a predetermined pressure and providing a second control signal when said one of said detected refrigerant pressures is below said predetermined pressure, third comparison means for comparing said calculated pressure change ratio with a predetermined pressure change ratio in a response to the comparison by said second comparison means and the presence of said second control signal, said third comparison means providing a third control signal when said calculated pressure change ratio is less than said predetermined pressure change ratio, wherein in response to said third control signal, first, second, third and fourth predetermined pressures are set equal to respective values of a first range of predetermined values, and in the absence of said third control signal, first, second, third and fourth predetermined pressure values are set equal to respective values of a second range of predetermined pressure values, fourth comparison means for comparing one of said detected refrigerant pressures with said second predetermined pressure and providing a fourth control signal when said one of said detected refrigerant pressures is less than said second predetermined pressure, wherein said capacity changing means changes the capacity of said compressor to a small capacity in response to said fourth control signal, fifth comparison means for comparing one of said detected refrigerant pressures with said first predetermined pressure and providing a fifth control signal when said one of said detected refrigerant pressures is greater than said first predetermined pressure, wherein said capacity changing means changes the capacity of said compressor to a large capacity in response to said fifth control signal, sixth comparison means for comparing one of said detected refrigerant pressures with a fourth predetermined pressure in response to the comparison by said fifth comparison means and the absence of said fifth control signal, said sixth comparison means providing a sixth control signal when said one of said detected refrigerant pressures is greater than said fourth predetermined pressure, wherein said electromagnetic clutch is turned off in response to the absence of said sixth control signal, and seventh comparison means for comparing one of said detected refrigerant pressures with said third predetermined pressure and providing a seventh control signal when said one of said detected refrigerant pressures is greater than said third predetermined pressure, wherein said electromagnetic clutch is turned on in response to said seventh control signal.