Patent ID: 6550262
Filing Date: 2003-04-22
Classification: F25B,Y10S

Abstract:
An expansion valve unit includinga temperature-sensing chamber for sensing a temperature of a refrigerant at an outlet of an evaporator to have a pressure therein increased and decreased, a high-pressure refrigerant passage formed in a side portion of a body, a low-pressure refrigerant passage formed in an end portion of the body on an opposite side of the temperature-sensing chamber, a valve seat located at an end surface on a low-pressure refrigerant passage side of a valve hole that communicates between the high-pressure refrigerant passage and the low-pressure refrigerant passage, a valve element capable of moving to and away from the valve seat, a spring for urging the valve element in a valve-closing direction, and a shaft for transmitting displacement of the temperature-sensing chamber caused by the increased and decreased pressure therein to the valve element, the expansion valve unit being characterized by a high-pressure refrigerant guide groove which is formed circumferentially in the body between the temperature-sensing chamber and the low-pressure refrigerant passage such that the high-pressure refrigerant guide groove communicates with the high-pressure refrigerant passage, whereby the temperature-sensing chamber is thermally insulated from the low-pressure refrigerant passage.