US 5,341,651 A · Control apparatus for use in automotive air conditioning system

Abstract

The present invention is directed to a control apparatus for use in an automotive air conditioning system which includes a variable capacity-type refrigerant compressor. The automotive air conditioning system comprises a refrigerant circuit including a refrigerant compressor with an externally controlled, variable capacity control mechanism; an evaporator connected to a suction chamber of the compressor; and a control apparatus which controls refrigerant circuit operation. The control apparatus includes an adjusting device for adjusting a control point of the compressor suction chamber pressure. During operation of the automotive air conditioning system, the control point of the compressor suction chamber pressure is adjusted to effectively maintain the temperature of air immediately downstream from the evaporator at the set temperature. In one situation in which the automotive air conditioning system is operated in a static thermodynamic condition of the evaporator, the control point of the compressor suction chamber pressure is adjusted to effectively converge the temperature of air immediately downstream from the evaporator to the set temperature. In another situation in which the automotive air conditioning system is operated in a dynamic thermodynamic condition of the evaporator, the control point of the compressor suction chamber is also adjusted to effectively converge the temperature of air immediately downstream from the set temperature. Accordingly, the passenger compartment of the automobile can be more effectively air conditioned during operation of the automotive air conditioning system.

Claims12

Dependent claims

An automotive air conditioning system comprising:

a refrigerant circuit having a refrigerant compressor with an externally controlled, variable capacity control mechanism and an evaporator connected to a suction chamber of said refrigerant compressor;
means for moving air through an exterior surface of said evaporator;
and
a control mechanism for controlling said circuit, wherein said control mechanism comprises:
means for sensing a thermodynamic characteristic relating to said evaporator;
gradient determining means for determining a gradient of the thermodynamic characteristic over a time period;
means for storing a relationship between said gradient and a coefficient;
coefficient determining means for determining a value for said coefficient by using the result of said gradient determining means and the relationship stored in said storing means;
feedback control means for monitoring the thermodynamic characteristic, comparing the thermodynamic characteristic to a set thermodynamic characteristic, and determining a feedback operational result for providing at least proportional control to said circuit;
and
pressure adjusting means for adjusting a control point of pressure in said suction chamber of said compressor responsive to said feedback operational result and said value of said coefficient determined by said coefficient determining means, whereby said feedback operational result is multiplied by said value.

8 more elements

Dependencies are inferred from the claim text.

Control apparatus for use in automotive air conditioning system

Life of this patent

Control apparatus for use in automotive air conditioning system

Life of this patent

Abstract

Claims12