MOTOR-OPERATED VALVE AND REFRIGERATION CYCLE SYSTEM

To improve controllability in a small flow rate area by preventing vibration of a main valve element in a small flow rate control area, in a motor-operated valve having two-stage flow rate control areas in which a main valve port of a main valve seat is kept in a fully closed state by a main valve element, and flow rate control in the small flow rate control area, of a refrigerant is performed by a throttle portion between an auxiliary valve port formed on the main valve element and a needle valve.SOLUTION: A main valve port 13a is kept in a fully closed state by a main valve element 3, and a fluid flows in a throttle portion (clearance) between a needle portion 42 of a needle valve 4 and an auxiliary valve port 33a to define a small flow rate control area. In the small flow rate control area, a tapered portion 41a (contact portion) of the needle valve 4 (auxiliary valve element) is brought into contact with a step portion 3a (contact portion) of the main valve element 3. By the contact of the taper portion 41a and the step portion 3a, the main valve element 3 is pressed toward a main valve seat 13 side by the needle valve 4.SELECTED DRAWING: Figure 3 【課題】主弁座の主弁ポートを主弁体で全閉状態とし、この主弁体に形成された副弁ポートとニードル弁との間の絞り部により冷媒の小流量制御域での流量制御を行う二段の流量制御域を有する電動弁において、小流量制御域での主弁体の振動を防止して、小流量域の制御性を向上させる。【解決手段】主弁体３で主弁ポート１３ａを全閉状態として、ニードル弁４のニードル部４２と副弁ポート３３ａとの絞り部（隙間）で流体を流して小流量制御域とする。小流量制御域のとき、ニードル弁４（副弁体）のテーパ部４１ａ（当接部）を主弁体３の段部３ａ（当接部）に当接させる。テーパ部４１ａと段部３ａとの当接により、ニードル弁４により主弁体３を主弁座１３側に押圧する。【選択図】図３