Expansion valve

Abstract

An expansion valve for a refrigerant circuit of a refrigeration apparatus is configured to depressurize a liquid refrigerant. The expansion valve includes a valve main body with a valve seat opening into a valve chest formed in the valve main body and a valve body movable relative to the valve chest in a reciprocating manner. An orifice is formed in the valve seat. The orifice has an orifice entrance with a smallest diameter, an orifice middle section widening in diameter along a direction of refrigerant outflow from the orifice entrance so as to form a first taper angle, and an orifice exit either widening in diameter or not in diameter along the direction of refrigerant outflow from the orifice middle section so as to form a second taper angle smaller than the first taper angle.

1 . An expansion valve for a refrigerant circuit of a refrigeration apparatus the expansion valve being configured to depressurize a liquid refrigerant, the expansion valve comprising:
 a valve main body with a valve seat opening into a valve chest being formed therein; and   a valve body movable relative to the valve chest in reciprocating manner;   an orifice being formed in the valve seat and having
 an orifice entrance with a smallest diameter, 
 an orifice middle section widening in diameter along a direction of refrigerant outflow from the orifice entrance so as to form a first taper angle, and 
 an orifice exit either widening in diameter or not changing in diameter along the direction of refrigerant outflow from the orifice middle section so as to form a second taper angle smaller than the first taper angle. 
   
     
     
         2 . The expansion valve according to  claim 1 , wherein:
 a first outflow direction length of the orifice middle section along tire: direction of refrigerant outflow is at least one times the minimum diameter of the orifice entrance.   
     
     
         3 . The expansion valve according to  claim 1 , wherein:
 the first taper angle is at least 10 degrees and no more than 60 degrees.   
     
     
         4 . The expansion valve according to  claim 1 , wherein:
 a second inclination angle formed by the orifice exit with a plane orthogonal to the direction of refrigerant outflow is greater than a first inclination angle formed by the orifice middle section with a plane orthogonal to the direction of refrigerant outflow, and   the second inclination angle is no more than 90 degrees.   
     
     
         5 . The expansion valve according  claim 1 , wherein;
 a second outflow direction length of the orifice exit along the direction of refrigerant outflow is no more than the first outflow direction length of the orifice middle section along the direction of refrigerant outflow.   
     
     
         6 . The expansion valve according to  claim 2 , wherein
 the first taper angle is at least 10 and no more than 60 degrees.   
     
     
         7 . The expansion valve according to  claim 6 , wherein
 a second inclination angle formed by the orifice exit with a plane orthogonal to the direction of refrigerant outflow is greater than a first inclination angle formed by the orifice middle section with a plane orthogonal to the direction of refrigerant outflow, and   the second inclination angle is no more than 90 degrees.   
     
     
         8 . The expansion valve according to  claim 7 ,
 a second outflow direction length of the orifice exit along the direction of refrigerant outflow is no more than the first outflow direction length of the orifice middle section along the direction of refrigerant outflow.   
     
     
         9 . The expansion valve according to  claim 2 , wherein
 a second inclination angle formed by the orifice exit with a plane orthogonal to the direction of refrigerant outflow is greater than a first inclination angle formed by the orifice middle section with a plane orthogonal to the direction of refrigerant outflow, and   the second inclination angle is no more than 90 degrees.   
     
     
         10 . The expansion valve according to  claim 2 ,
 a second outflow direction length of the orifice exit along the direction of refrigerant outflow is no more than the first outflow direction length of the orifice middle section along the direction of refrigerant outflow.   
     
     
         11 . The expansion valve according to  claim 3 , wherein
 a second inclination angle formed by the orifice exit with a plane orthogonal to the direction of refrigerant outflow is greater than a first inclination angle formed by the orifice middle section with a plane orthogonal to the direction of refrigerant outflow, and   the second inclination angle is no more than 90 degrees.   
     
     
         12 . The expansion valve according to  claim 3 ,
 a second outflow direction length of the orifice exit along the direction of refrigerant outflow is no more than the first outflow direction length of the orifice middle section along the direction of refrigerant outflow.   
     
     
         13 . The expansion valve according to  claim 4 ,
 a second outflow direction length of the orifice exit along the direction of refrigerant outflow is no more than the first outflow direction length of the orifice middle section along the direction of refrigerant outflow.