Patent ID: 8267329

Claim:
An expansion valve with noise reduction means comprising: a valve body; an inlet port formed in the valve body and through which a high pressure liquid refrigerant is introduced; a valve chamber communicating with the inlet port and having a lower end opening in a bottom surface of the valve body; the inlet port including a large diameter passage portion formed from one side surface toward the other side surface of the valve body, and also including a small diameter passage portion that provides communication between the large diameter passage portion and the valve chamber, the large diameter passage portion including a bottom end at the lowest portion of the large diameter passage portion, and a vertical end face being defined by a surface between the large diameter passage portion and the small diameter passage portion; a valve hole provided in the valve chamber; an outlet port formed in the valve body and through which the refrigerant expanded in the valve hole is discharged to the outside; a valve member that is brought close to and apart from a valve seat provided at an inlet of the valve hole and opens and closes the valve hole; a coil spring provided in the valve chamber for biasing the valve member toward the valve hole; a plug that is inserted and mounted into the lower end of the valve chamber to support a lower end of the coil spring, and closes the opening of the valve chamber, an outer peripheral portion of the plug having a stepped diameter decreasing toward an upper end; an annular space formed in the valve chamber below the small diameter passage portion of the inlet port and extending from above the elevation of the bottom end of the large diameter passage portion; and an O ring located below and adjacent the small diameter passage portion and being above the bottom end and on the opposite side of the vertical end face of the large diameter passage portion, wherein the O ring is disposed in the annular space formed between the vertical end face of the large diameter passage portion and a side surface of the valve chamber.