Air conditioning system expansion valve

Abstract

The invention relates to an expansion valve, designed especially for an air conditioning system in a motor vehicle, that comprises a valve housing with a first high-pressure side port, a second low-pressure side port, and a channel disposed therebetween through which refrigerant can flow. The valve includes a sliding element that is arranged in the channel and can move along a longitudinal axis, wherein an aperture restricts the flow of refrigerant through the channel, and the size and shape of the aperture is defined by the size and shape of the sliding element and the position of the sliding element in the channel. The expansion valve is easy to manufacture and can be universally used based in part on the sliding element extending completely through the channel.

1 . An expansion valve, especially for an air conditioning system of a motor vehicle, comprising: 
 a valve housing that includes a first port and a second port and a first refrigerant channel disposed between the first and second ports; and    a sliding valve element that is capable of movement that defines a stroke along a longitudinal axis, wherein the position of the valve element along its stroke determines the amount of refrigerant that may flow in the channel and wherein the sliding element completely extends through the channel throughout its stroke.    
   
   
       2 . An expansion valve according to  claim 1 , wherein the valve element is disposed in a hole that crosses the refrigerant channel.  
   
   
       3 . An expansion valve according to  claim 1 , wherein the valve element comprises an elongated body that includes an end section of a constant cross-section and a directly adjacent control section with a tapered cross-section.  
   
   
       4 . An expansion valve according to  claim 3 , wherein the control section of the valve element includes a cross-section that changes over its length.  
   
   
       5 . An expansion valve according to claims  3 , wherein the diameter of end section of the valve element is larger than the diameter of the first refrigerant channel.  
   
   
       6 . An expansion valve according to  claim 1 , wherein a control mechanism determines the position of the valve element in its stroke.  
   
   
       7 . An expansion valve according to  claim 6 , wherein the control mechanism includes a spring that exerts a force upon the valve element.  
   
   
       8 . An expansion valve according to  claim 7 , wherein the spring and the control mechanism are disposed on the same side of the first refrigerant channel.  
   
   
       9 . An expansion valve according to claims  6 , wherein the control mechanism includes a pressure-loaded membrane.  
   
   
       10 . An expansion valve according to  claim 9 , wherein the valve housing further includes a third port.  
   
   
       11 . An expansion valve according to  claim 10 , wherein the valve housing further includes a fourth port and a second refrigerant channel disposed between the third and fourth ports.  
   
   
       12 . An expansion valve according to  claim 10 , wherein the pressure of refrigerant available at the third port exerts a force upon the membrane.  
   
   
       13 . An expansion valve according to  claim 10 , wherein a closed volume exerts pressure upon the membrane and wherein the volume is in thermal contact with refrigerant available at the third port.  
   
   
       14 . An expansion valve according to  claim 10 , wherein the pressure of refrigerant in a refrigerant channel exerts a force upon the membrane.  
   
   
       15 . An expansion valve according to  claim 10 , wherein the initial position of the valve element is determined by position of the control mechanism in relation to the valve housing.