THROTTLING DEVICE AND REFRIGERATION CYCLE SYSTEM

摘要

A throttling device which can suppress noise and a refrigeration cycle system are provided. This throttling device (10) is provided with: a valve seat member (2) which comprises a valve port (21); a needle valve (4) which makes it possible to change the opening degree of the valve port (21); and a cylindrical guide member (3) which guides forward and backward movement of the needle valve (4). On the needle valve (4) and the guide member (3), sliding surfaces (34, 46) are formed which face one another across a predetermined gap and which can slide against one another. The gap functions as an intermediate flow path (45) allowing a fluid to pass from the valve port (21) towards the secondary side, and on the sliding surface (46) of the needle valve (4), a concave groove (47) is formed which is a flow path expanded portion that is recessed in the direction away from the sliding surface (34) of the guide member (3) and that expands the width dimension of the intermediate flow path (45).