Mobile air conditioning system and control mechanism

In a vehicular air conditioning system including a compressor, a condenser, and an evaporator connected in series for cyclic refrigerant flow therein and wherein the vehicle engine drives the compressor so that the refrigerant pumping capacity of the compressor increases and decreases with increases and decreases in vehicle engine speed, and the heat rejection capacity of the condenser increases and decreases with air flow there through with increases and decreases in vehicle speed and engine fan speed, so that the air conditioning system operating capacity changes with vehicle operation between idle and road run, a control system for controlling the flow of refrigerant flow in the air conditioning system comprising:

• an accumulator coupled between the evaporator and the compressor;
• a pressure sensitive control valve having an input port, an output port, a variable valve mechanism there between having a variable opening for connecting the input port to the output port and a pressure sensing mechanism coupled to the variable valve mechanism for providing a displacement movement thereto for controlling the size of the opening of the valve mechanism;
• means for coupling the input and output port of the pressure sensitive valve in the air conditioning system between the condenser and the evaporator, and
• means for coupling the pressure mechanism to sense the refrigerant pressure adjacent to the evaporator to control the refrigerant flow through the valve mechanism as a function of the magnitude of the sensed pressure in a direction toward enhancing the heat absorbing capacity of the evaporator as the air conditioning system operating capacity changes as vehicle operation changes between idle and road run.

In a vehicular air conditioning system including a compressor, a condenser, and an evaporator connected in series for cyclic refrigerant flow therein and wherein the vehicle engine drives the compressor so that the refrigerant pumping capacity of the compressor increases and decreases with increases and decreases in vehicle speed, and the heat rejection capacity of the condenser increases and decreases with air flow there through with increases and decreases in vehicle speed and engine fan speed, a control system comprising:

• an accumulator coupled between the evaporator and the compressor for storing liquid refrigerant received from the evaporator and for releasing stored refrigerant into the air conditioning system to control the amount of active refrigerant in the air conditioning system;
• a pressure sensitive control valve having an input port, an output port, a valve between the input port and output port, and a pressure sensing mechanism coupled to the valve for providing a displacement movement thereto as a function of sensed pressure for controlling the size of the valve opening;
• means for coupling the input and output ports of the pressure sensitive valve in the air conditioning system wherein the valve controls the refrigerant flow from the condenser to the evaporator, and
• means for coupling the pressure sensing mechanism to sense refrigerant pressure adjacent the evaporator so that the valve functions as a variable orifice to control the amount of refrigerant flow through the system while interacting with the accumulator in a direction toward achieving heat absorption over substantially the entire evaporator with variations in compressor and condenser capacities.

A variable orifice control system for vehicular air conditioning systems including a compressor, a condenser, and an evaporator connected in series for cyclic refrigerant flow therein, and wherein the vehicular air conditioning system capacities change when the vehicle engine that drives the compressor changes speed wherein the refrigerant pumping capacity of the compressor increases and decreases with increases and decreases in vehicle engine speed, and wherein the heat rejection capacity of the condenser increases and decreases with air flow there through with increases and decreases in vehicle speed and engine fan speed, the control system comprising:

• refrigerant storage means coupled between the evaporator and the compressor for storing liquid refrigerant received from the evaporator and for releasing stored refrigerant into the air conditioning system to control the amount of active refrigerant in the air conditioning system;
• a pressure sensitive control valve having an input port, an output port, a valve between the input port and output port, and a pressure sensing mechanism coupled to the valve for providing a displacement movement thereto as a function of sensed pressure for controlling the size of the valve opening;
• means for coupling the input and output ports of the pressure sensitive valve in the air conditioning system between the condenser and the evaporator, and
• means for coupling the pressure sensing mechanism to sense refrigerant pressure adjacent the evaporator so that the valve functions as a variable orifice to vary the amount of refrigerant flowing in the air conditioning system in a direction for enhancing the evaporator cooling capacity as air conditioning system operating capacities change.