Patent ID: 7263857
Filing Date: 2007-09-04
Classification: F25B,Y02B

Abstract:
1. A constant flow rate expansion valve including a main valve for controlling a flow rate of refrigerant, a piston for actuating the main valve in a valve-opening/closing direction by differential pressure between pressure on an upstream side of the main valve and pressure in a pressure chamber formed on a side opposite to the main valve, and a pilot valve controlled such that the pressure in the pressure chamber is set by a solenoid, and becomes constant by sensing a change in the flow rate of refrigerant, wherein a restriction passage for generating differential pressure in proportion to the flow rate of refrigerant so as to control the pilot valve by the differential pressure and the main valve are arranged in series between a refrigerant inlet port and a refrigerant outlet port in a direction of flow of refrigerant, while the pilot valve, the pressure chamber, and a fixed orifice arranged in series in the direction of flow of the refrigerant are disposed in parallel with the main valve.