초록 ▼

An automotive air conditioner has an air duct in which a refrigerant evaporator of a refrigeration cycle is disposed in fluid-flow communication with a variable capacity refrigerant compressor driven by an automotive engine and provided with compressor displacement varying members. A blower is provi

An automotive air conditioner has an air duct in which a refrigerant evaporator of a refrigeration cycle is disposed in fluid-flow communication with a variable capacity refrigerant compressor driven by an automotive engine and provided with compressor displacement varying members. A blower is provided to cause air to flow through the evaporator and through the duct into the passenger compartment. A sensor is provided to detect a condition representing the cooling operation of the evaporator, such as the air temperature downstream of the evaporator, surface temperature thereof or the pressure of the refrigerant at the evaporator. An electric controlling circuit is operative in response to signals from the sensor to actuate a servo motor which in turn drives the compressor displacement varying members whereby the capacity of the compressor is varied in accordance with the condition detected by the sensor.

대표청구항 ▼

1. An air conditioning system comprising: a duct defining therein an air passage having a downstream end open to a chamber to be air-conditioned; a refrigeration system including: a variable capacity refrigerant compressor including means for varying the displacement of said compressor and mean

1. An air conditioning system comprising: a duct defining therein an air passage having a downstream end open to a chamber to be air-conditioned; a refrigeration system including: a variable capacity refrigerant compressor including means for varying the displacement of said compressor and means for driving said compressor displacement varying means; and an evaporator disposed in said air passage and being in fluid-flow communication with the intake side of said compressor; means for causing air to flow through said evaporator and through said duct into said chamber; a heater disposed in said duct downstream of said evaporator and being operative to heat at least a part of the air which has passed through said evaporator; means for controlling the heating of the air by said heater; and means for controlling the capacity of said compressor, said capacity controlling means including: sensor means operative to detect a condition related to the cooling operation of said evaporator and emit a first electric signal representing the condition thus detected; means for detecting the position of said air heating controlling means to emit a second electric signal representing the position thus detected; and electric circuit means operative in response to said first and second electric signals from said sensor means and from said position detecting means to actuate said driving means for thereby varying the displacement of said compressor whereby the capacity of said refrigeration system can be controlled, said electric circuit means including: (a) means emitting a third electric signal in accordance with the ratio between said first and second electric signals; (b) a first comparator means operative to compare said third electric signal with a first electric reference signal to emit a first electric output; (c) a second comparator means operative to compare said third electric signal with a second electric reference signal different from said first electric reference signal to emit a second electric output; (d) first electric actuating means responsive to said first electric output to actuate said driving means in a direction to decrease the compressor displacement; and (e) a second electric actuating means responsive to said second electric output to actuate said driving means in a direction to increase the compressor displacement. 2. An air conditioning system as claimed in claim 1, wherein said third electric signal emitting means comprises an electric connection electrically connecting said sensor means to said position detecting means in series and electrically connected to said first and second comparator means. 3. An air conditioning system comprising: a duct defining therein an air passage having a downstream end open to a chamber to be air-conditioned; a refrigeration system including: a variable capacity refrigerant compressor including means for varying the displacement of said compressor; and an evaporator disposed in said air passage and being in fluid-flow communication with the intake side of said compressor; means for causing air to flow through said evaporator and through said duct into said chamber; a heater disposed in said duct downstream of said evaporator and being operative to heat at least a part of the air which has passed through said evaporator; means for controlling the heating of the air by said heater; and means for controlling the capacity of said compressor, said capacity controlling means including: sensor means operative to detect the temperature of air downstream of said evaporator; means for detecting the position of said air heating controlling means; and electric circuit means operative in response to signals from said sensor means and from said position detecting means to actuate said means for varying the displacement of said compressor whereby the capacity of said refrigeration system can be controlled. 4. An air conditioning system as claimed in claim 1, wherein said sensor means comprises a temperature sensor element disposed to detect the temperature of air downstream of said evaporator. 5. An air conditioning system as claimed in claim 1, wherein said sensor means comprises a temperature sensor element disposed to detect the temperature of the surface of said evaporator. 6. An air conditioning system as claimed in claim 3, wherein said sensor means comprises a pressure sensor for detecting the pressure of the refrigerant at said evaporator. 7. An air conditioning system as claimed in claim 3, wherein said air passage includes a portion bypassing said heater and said means for controlling the heating of the air comprises a valve means operative to control the ratio of the air flow from said evaporator to and through said heater to the air flow from said evaporator and through said bypassing portion. 8. An air conditioning system as claimed in claim 1, wherein said refrigeration system further includes an additional position detecting means for detecting the position of said compressor displacement varying means and emitting a signal representing said detected position, and wherein third electric signal emitting means is operative to emit said third electric signal according to the ratio of the sum of said first and additional electric signals to said second electric signal. 9. An air conditioning system as claimed in claim 8, wherein said third electric signal emitting means comprises a first electric connection electrically connecting said sensor means to said additional position detecting means in series to form a first series circuit, and a second electric connection electrically connecting said first series circuit to the first-mentioned position detecting means in series, said second electric connection being electrically connected to said first and second comparator means. 10. An air conditioning system as claimed in claim 4, wherein said refrigeration system further includes an additional position detecting means for detecting the position of said compressor displacement varying means and wherein said electric circuit means are operative also in response to a signal from said additional position detecting means. 11. An air conditioning system as claimed in claim 5, wherein said refrigeration system further includes an additional position detecting means for detecting the position of said compressor displacement varying means and wherein said electric circuit means are operative also in response to a signal from said additional position detecting means. 12. An air conditioning system as claimed in claim 6, wherein said refrigeration system further includes an additional position detecting means for detecting the position of said compressor displacement varying means and wherein said electric circuit means are operative also in response to a signal from said additional position detecting means. 13. An air conditioning system as claimed in claim 7, wherein said refrigeration system further includes an additional position detecting means for detecting the position of said compressor displacement varying means and wherein said electric circuit means are operative also in response to a signal from said additional position detecting means.