Expansion valve

摘要

An expansion valve wherein a plunger slidably fitted in a hollow member for sliding movement and opening and closing valve ports formed in the hollow member is driven by an electromagnetic force, and two chambers defined between opposite ends of the plunger and the hollow member are maintained in communication with each other through a pressure equalization passageway formed in the plunger. The expansion valve is capable of allowing a refrigerant to flow therethrough without any resistance offered to its flow and having ability to allow reversible flow of the refrigerant to take place with high responsiveness.