Patent ID: 7832653

Claim:
An expansion valve comprising: a valve body; an inlet port and an outlet port formed in the valve body; a valve chamber formed in the valve body; a refrigerant flow passage formed in the valve body and connecting the inlet port and the outlet port through the valve chamber; a valve member accommodated in the valve chamber; a first throttle formed in the refrigerant flow passage; and a second throttle formed in the refrigerant flow passage downstream from the first throttle; and an enlarged space portion is formed in the refrigerant flow passage between the first throttle and the second throttle, wherein the valve body has a first partition wall partitioning a refrigerant flow in the refrigerant flow passage and a second partition wall partitioning a refrigerant flow downstream from the first partition wall, with the first partition wall including a first valve hole and the second partition wall including a second valve hole; the valve member is formed from a rod-shaped member, and the rod-shaped member has an outer surface including a first valve portion forming the first throttle with the first valve hole and a second valve portion forming the second throttle with the second valve hole; the first throttle having an open degree that is variable by advancing and retracting the first valve portion with respect to a valve seat of the first valve hole; a groove is formed in an outer surface of the second valve portion or an inner surface of the second valve hole; at least either one of the outer surface of the second valve portion and the inner surface of the second valve hole is tapered toward a distal end of the valve member; the second throttle includes a passage formed between the groove and the outer surface of the second valve portion or the inner surface of the second valve hole that faces the groove, and the enlarged space portion is formed by increasing the inner diameter of part of the refrigerant flow passage.