THROTTLING DEVICE AND REFRIGERATION CYCLE

摘要

In this throttling device (10) which reduces the pressure of the refrigerant condensed by the condenser in a refrigeration cycle and feeds said refrigerant to an evaporator, hunting of a needle valve (4) is prevented and hysteresis in differential pressure/flow characteristics in the high-pressure region are reduced. A cylindrical main body case (1) configures a primary chamber (11) connected to the condenser and a secondary chamber (12) connected to the evaporator, and a valve seat member (2), in which a valve port (21) is formed, and a cylindrical guide member (3), which is integral with said valve seat member (2), are provided in the cylindrical main body case (1). In the guide member (3), a coil spring (7) is provided which biases towards the needle valve (4) and the valve port (21). A blade member (5) is provided on a boss portion (43) of the needle valve (4). A blade (51) of the blade member (5) is brought into contact with a cylindrical guide surface (31a) of the guide member (3) to apply sliding resistance. The blade (52) is displaced by the fluid pressure of the refrigerant flowing from introduction paths (45) to a back pressure chamber (44), decreasing the sliding resistance.