MOTOR-DRIVEN VALVE AND REFRIGERATION CYCLE SYSTEM

To reduce refrigerant passing noise at a throttle portion, in particular, in a small flow rate control region of, for example, a two stage-type motor-driven valve, in the motor-driven valve constituted such that a needle portion does not sit on a valve seat around a valve port.SOLUTION: An opening of an auxiliary valve port 33a is changed by a needle valve 4 to be applied as a small flow rate control region. A main valve element 3 brings a main valve port 13a into a full-open state to be applied as a large flow rate control region, thus the flow rate control regions of two stages are provided. Grooves 6 are formed as a second throttle portion continued to a first throttle portion (clearance) between an auxiliary valve seat 33 acting in the small flow rate control region and a needle portion 42 of the needle valve 4. Six grooves 6 are formed on an opening edge at an auxiliary valve chamber 3R side, of the valve port 33a. The grooves 6 are formed on positions rotationally symmetric to an axis L at equal intervals (every 60°) around the axis L. By the grooves 6, differential pressure before and behind of the throttle portion composed of the auxiliary valve seat 33 and the needle portion 42, is reduced.SELECTED DRAWING: Figure 4 【課題】ニードル部が弁ポートの周囲の弁座に着座しないよう構成された電動弁において、例えば二段式の電動弁の特に小流量制御域での絞り部の冷媒通過音を低減する。【解決手段】ニードル弁４で副弁ポート３３ａの開度を変更して小流量制御域とする。主弁体３が主弁ポート１３ａを全開状態として大流量制御域とし、二段の流量制御域を設ける。小流量制御域で作用する副弁座３３とニードル弁４のニードル部４２との第１絞り部（隙間）に連続する第２絞り部としての溝６を形成する。溝６は、弁ポート３３ａの副弁室３Ｒ側の開口縁に６個形成する。溝６は、軸線Ｌ周りで等間隔（６０°毎）となる軸線Ｌに対して回転対称な位置に形成する。溝６により、副弁座３３とニードル部４２とで構成される絞り部の前後の差圧を減少させる。【選択図】図４