Expansion valve

Abstract

An expansion valve for a refrigerant cycle has an orifice passage portion, a valve body, a spring member and a deformation portion. The orifice passage portion is configured for decompressing and expanding a high pressure refrigerant into a low pressure refrigerant. The valve body is disposed to open and close the orifice passage portion so that a flow rate of the low pressure refrigerant flowing into a low pressure passage portion is controlled in accordance with a valve opening degree. The spring member is disposed between the valve body and the deformation portion for applying a biasing force to the valve body. The deformation portion is plastically deformable in a direction parallel to an expansion and contraction direction of the spring member by applying an external force.

1 . An expansion valve for a refrigerant cycle, comprising:
 a high pressure passage portion that allows a high pressure refrigerant to flow;   an orifice passage portion disposed to communicate with the high pressure passage portion for decompressing and expanding the high pressure refrigerant, which flows from the high pressure passage portion, into a low pressure refrigerant;   a low pressure passage portion disposed to communicate with the orifice passage portion for allowing the low pressure refrigerant to flow;   a valve body disposed to open and close the orifice passage portion such that a flow rate of the low pressure refrigerant flowing into the low pressure passage portion is controlled in accordance with an opening degree of the valve body;   a spring member disposed to apply a biasing force to the valve body; and   a deformation portion disposed on an opposite side of the valve body with respect to the spring member such that the spring member is interposed between the deformation portion and the valve body, wherein   the deformation portion is plastically deformable in a direction parallel to an expansion and contraction direction of the spring member by an external force.   
   
   
       2 . The expansion valve according to  claim 1 , further comprising:
 a main body block, wherein   the spring member is housed in the main body block, and   the deformation portion is provided by a wall of the main body block, the wall having a thickness that is smaller than a thickness of a peripheral area thereof in the main body block with respect to the direction parallel to the expansion and contraction direction of the spring member.   
   
   
       3 . The expansion valve according to  claim 1 , further comprising:
 a main body block that houses the spring member therein, the main body block having an opening portion at a position opposite to the valve body; and   a deformation plate member having a shape corresponding to the opening portion, wherein   the deformation plate member is disposed in the opening portion and fixed to the main body block, and   the deformation portion is provided by the deformation plate member.   
   
   
       4 . The expansion valve according to  claim 3 , wherein
 the opening portion has an inner diameter that is greater than an outer diameter of the spring member, the outer diameter of the spring member being defined in a direction perpendicular to the expansion and contraction direction of the spring member.   
   
   
       5 . The expansion valve according to  claim 1 , wherein
 the deformation portion has a first surface to which the external force is applied and a second surface that receives the spring member, and   an area of the first surface is equal to or greater than that of the second surface.   
   
   
       6 . The expansion valve according to  claim 5 , wherein
 the thickness of the deformation portion is at least 0.5 mm and at most 2 mm, and   the second surface has an outer diameter that is at least 7 mm and at most 20 mm.   
   
   
       7 . The expansion valve according to  claim 5 , wherein
 the main body block has a peripheral wall portion that coaxially extends from the first surface of the wall.   
   
   
       8 . The expansion valve according to  claim 7 , wherein
 the peripheral wall portion has a thread portion so that an adjustment jig for applying the external force is capable of being screwed into the peripheral wall portion.   
   
   
       9 . The expansion valve according to  claim 2 , wherein
 the main body block has a tubular projection projecting from the deformation portion, and   the tubular projection includes a thread portion so that an adjustment jig for applying the eternal force is capable of being screwed into the tubular projection.   
   
   
       10 . An expansion valve for a refrigerant cycle, comprising:
 a main body block having a high pressure passage portion, a low pressure passage portion and a communication passage portion between the high pressure passage portion and the low pressure passage portion;   a valve element disposed in the communication passage portion so that an orifice passage is defined for decompressing and expanding a high pressure refrigerant, which flows from the high pressure passage portion, into a low pressure refrigerant and for controlling a flow rate of the low pressure refrigerant flowing into the low pressure passage portion in accordance with an opening degree of the orifice passage;   a spring member disposed in the communication passage portion for applying a biasing force to the valve element; and   a deformation portion disposed on a side opposite to the valve element with respect to the spring member to define an end of the communication passage portion, wherein   the spring member is disposed between the valve element and the deformation portion and a set value of the spring member is adjusted by deforming the deformation portion by a predetermined amount in a direction parallel to an expansion and contraction direction of the spring member.   
   
   
       11 . The expansion valve according to  claim 10 , wherein
 the deformation portion is integrally formed into the main body block, and has a predetermined thickness in the direction parallel to the expansion and contraction direction of the spring member.   
   
   
       12 . The expansion valve according to  claim 10 , wherein
 the main body block has a recessed portion on its outer wall and at a position opposite to the communication passage portion with respect to the deformation portion for receiving an adjustment jig when the deformation portion is deformed.