Patent ID: 9726406
Date: 2017-08-08
CPC Classifications: F16K,F25B,Y02B

Claim:
1. An expansion valve having: a valve housing defining a cylindrical main valve chamber; a first port communicated with the main valve chamber; a second port communicated with an axial end of the main valve chamber; a sub-valve arranged in the main valve chamber so as to move in a direction of an axis of the main valve chamber, the sub-valve having a valve port located between the main valve chamber and the second port; and a valve body arranged to move in the direction of the axis of the main valve chamber with respect to the sub-valve to open and close the valve port, wherein when a refrigerant flows from the first port to the second port, the sub-valve is seated on a circumference of the second port due to difference in pressures in the first port and the second port to make the second port to be in a closed state and a flow rate of the refrigerant flowing through the valve port is reduced by the valve body, and when the refrigerant flows from the second port to the first port, the sub-valve moves away from the second port due to difference in pressures in the first port and the second port to make the second port to be in a fully-open state, wherein the sub-valve comprises: a guide member arranged to slidably contact with an inner circumferential face of the valve housing and formed by pressing a metal plate; and a valve seat member having the valve port and arranged at a center of the guide member, the valve seat member being formed by cutting a metal material wherein the guide member includes a disk portion arranged to intersect perpendicularly with the axis of the main valve chamber and a fitting hole formed at a center of the disk portion, wherein the valve seat member includes a disk-like flange portion and a ring-like annular boss portion formed at an upper part of the flange portion, and wherein the annular boss portion of the valve seat member is passed through the fitting hole of the guide member, and an end of the annular boss portion is crimped so as to extend outward to bond the flange portion and the disk portion tightly together, and a welding is applied to a contact portion at which an edge of the disk portion and an edge of the flange portion contact each other to firmly fix the guide member and the valve seat member to each other.