Patent ID: 6895993

Claim:
An expansion valve mounted to an air conditioner for controlling the flow of a refrigerant, the expansion valve comprising; a piping member including piping member refrigerant passages to which pipes communicated to various equipments of the air conditioner are connected; a cassette unit inserted to the piping member, said cassette unit comprising a tube member formed integrally with a flange unit as an integral construction and including tube member refrigerant passages with respective ones of the tube member refrigerant passages corresponding to and aligned with respective ones of the piping member refrigerant passages; a guide member having a large diameter portion and a small diameter portion, an orifice member, and a plate member fixed to the inside of the tube member; a valve means equipped inside a valve chamber defined by said orifice member and including a shaft extending through and operative to slide relative to the guide member; the plate member further defining said valve chamber; a spring disposed between the plate member and the valve means for biasing the valve means toward the orifice member; a shaft member for driving the valve means; a lid member welded onto the flange portion; a diaphragm pinched between the lid member and the flange portion and defining a gas charge chamber and a stopper member for transmitting the displacement of the diaphragm to the shaft member; a ring for fixing to the piping member the lid member of the cassette unit inserted to the piping member; and a seal member disposed between the outer wall of the cassette unit and the inner wall of the piping member, the seal member being retained in a space formed between and defined by a tubular member stepped inner wall surface of the tubular member and a piping member stepped inner wall surface of the piping member disposed in offset confronting relations with one another, the seal member in contact with the tubular member stepped inner wall surface and positioned to surround the small diameter portion of the guide member.