JP5657424B2

JP5657424B2 - Motorized valve

Info

Publication number: JP5657424B2
Application number: JP2011038673A
Authority: JP
Inventors: 裕介荒井
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2011-02-24
Filing date: 2011-02-24
Publication date: 2015-01-21
Anticipated expiration: 2031-02-24
Also published as: JP2012172836A

Description

本発明は、ヒートポンプ式冷暖房システム等に使用するのに好適な電動弁に係り、特に、小流量時の流量制御精度の向上と制御可能流量の増大化・圧力損失の低減化の両方を効果的に図ることのできる電動弁に関する。 The present invention relates to a motor-operated valve suitable for use in a heat pump type air conditioning system and the like, and in particular, it is effective to improve both flow rate control accuracy at a small flow rate, increase controllable flow rate, and reduce pressure loss. The present invention relates to a motor-operated valve that can be achieved.

一般的なヒートポンプ式冷暖房システムでは、冷媒は冷房運転時と暖房運転時とでは逆方向に流されるようにされており、このヒートポンプ式冷暖房システムとして、圧縮機、室外熱交換器、室内熱交換器、四方切換弁等の他、省エネ効率等を向上させるため、通常は一つでよい膨張弁を二つを備え、さらに、圧力損失を可及的に低減するため、それら二つの膨張弁にそれぞれ並列に逆止弁を組み込んだもの（逆止弁付き膨張弁としたもの）が知られている（例えば、下記特許文献１の図６を参照）。 In a general heat pump type air conditioning system, the refrigerant flows in the opposite direction during the cooling operation and the heating operation. As this heat pump type air conditioning system, a compressor, an outdoor heat exchanger, an indoor heat exchanger are used. In addition to four-way switching valves, etc., in order to improve energy-saving efficiency, etc., normally two expansion valves are sufficient, and in order to reduce pressure loss as much as possible, each of these two expansion valves A valve that incorporates a check valve in parallel (an expansion valve with a check valve) is known (see, for example, FIG. 6 of Patent Document 1 below).

また、最近では、その二つの逆止弁付き膨張弁のうちの少なくとも一方を電子制御式電動弁に置き換えることが考えられている（下記特許文献２を参照）。かかる逆止弁付き膨張弁に代えて用いられる電子制御式電動弁の一例を図５に示す。 Recently, it has been considered to replace at least one of the two expansion valves with a check valve with an electronically controlled motor-operated valve (see Patent Document 2 below). An example of an electronically controlled motor-operated valve used in place of the check valve-equipped expansion valve is shown in FIG.

図示例の電動弁１０’は、下部大径部２５ａと上部小径部２５ｂを有する弁軸と、弁室２１を有する弁本体２０と、この弁本体２０にその下端部が密封接合されたキャン４０と、このキャン４０の内周に所定の間隙αをあけて配在されたロータ３０と、このロータ３０を回転駆動すべく前記キャン４０に外嵌されたステータ５０と、を備えている。 The motor-operated valve 10 'in the illustrated example includes a valve shaft having a lower large-diameter portion 25a and an upper small-diameter portion 25b, a valve main body 20 having a valve chamber 21, and a can 40 having a lower end sealed to the valve main body 20. And a rotor 30 disposed with a predetermined gap α on the inner periphery of the can 40, and a stator 50 externally fitted to the can 40 for rotationally driving the rotor 30.

前記弁軸２５は、その下部大径部２５ａの下端部に特定形状（それぞれ所定の中心角を持つ二段の逆円錐台状）の弁体部２４が一体に設けられており、本電動弁１０’では、この弁体部２４のリフト量を変化させることにより冷媒の通過流量を制御するようになっている。 The valve shaft 25 is integrally provided with a valve body portion 24 having a specific shape (a two-stage inverted truncated cone shape each having a predetermined center angle) at the lower end portion of the lower large-diameter portion 25a. In 10 ', the flow rate of the refrigerant is controlled by changing the lift amount of the valve body 24.

前記弁本体２０の弁室２１には、その下部に前記弁体部２４が接離する弁口（オリフィス）２２ａ付き弁座２２が設けられるとともに、その側部に第１流入口１１が開口せしめられ、また、弁本体２０の下部には、前記弁口２２ａに連なって第１流出口１２が設けられている。 The valve chamber 21 of the valve body 20 is provided with a valve seat 22 with a valve port (orifice) 22a to which the valve body portion 24 contacts and separates at a lower portion thereof, and the first inlet 11 is opened at a side portion thereof. In addition, a first outlet 12 is provided in the lower part of the valve main body 20 so as to continue to the valve port 22a.

前記ステータ５０は、ヨーク５１、ボビン５２、ステータコイル５３、及び樹脂モールドカバー５６等で構成され、前記ロータ３０やステータ５０等でステッピングモータが構成され、該ステッピングモータや後述する送りねじ（雌ねじ部３８、雄ねじ部２８）等で前記弁口２２ａに対する弁体部２４のリフト量（＝開度）を調整するための昇降駆動機構が構成される。 The stator 50 is composed of a yoke 51, a bobbin 52, a stator coil 53, a resin mold cover 56, and the like. A stepping motor is composed of the rotor 30, the stator 50, and the like. 38, a male screw portion 28) and the like constitute an elevation drive mechanism for adjusting the lift amount (= opening degree) of the valve body portion 24 with respect to the valve port 22a.

前記ロータ３０には、支持リング３６が一体的に結合されるとともに、この支持リング３６に、ガイドブッシュ２６の外周に配在された下方開口で筒状の弁軸ホルダ３２の上部突部がかしめ固定され、これにより、ロータ３０、支持リング３６及び弁軸ホルダ３２が一体的に連結されている。 A support ring 36 is integrally coupled to the rotor 30, and an upper protrusion of the cylindrical valve shaft holder 32 is caulked to the support ring 36 at a lower opening disposed on the outer periphery of the guide bush 26. Thus, the rotor 30, the support ring 36, and the valve shaft holder 32 are integrally connected.

また、弁本体２０の上部に設けられた嵌合穴４２には、筒状のガイドブッシュ２６の下端部が圧入固定され、このガイドブッシュ２６には弁軸２５（の下部大径部２５ａ）が摺動自在に内挿されている。また、前記ロータ３０の回転を利用して前記弁軸２５（弁体部２４）を昇降させるべく、前記ガイドブッシュ２６の外周に雄ねじ部２８が形成され、前記弁軸ホルダ３２の内周には雌ねじ部３８が形成されており、それら雄ねじ部２８と雌ねじ部３８とで送りねじが構成されている。 A lower end portion of a cylindrical guide bush 26 is press-fitted and fixed in a fitting hole 42 provided in the upper portion of the valve body 20, and the valve shaft 25 (the lower large diameter portion 25 a thereof) is fixed to the guide bush 26. It is slidably inserted. In addition, a male screw portion 28 is formed on the outer periphery of the guide bush 26 to raise and lower the valve shaft 25 (valve body portion 24) using the rotation of the rotor 30, and on the inner periphery of the valve shaft holder 32. A female screw portion 38 is formed, and the male screw portion 28 and the female screw portion 38 constitute a feed screw.

また、前記ガイドブッシュ２６の上部小径部２６ｂが弁軸ホルダ３２の上部に内挿されるとともに、弁軸ホルダ３２の天井部中央（に形成された通し穴）に弁軸２５の上部小径部２５ｂが挿通せしめられている。弁軸２５の上部小径部２５ｂの上端部にはプッシュナット３３が圧入固定されている。 The upper small diameter portion 26b of the guide bush 26 is inserted into the upper portion of the valve shaft holder 32, and the upper small diameter portion 25b of the valve shaft 25 is formed at the center of the ceiling portion of the valve shaft holder 32 (through hole formed therein). It is inserted. A push nut 33 is press-fitted and fixed to the upper end portion of the upper small diameter portion 25 b of the valve shaft 25.

また、前記弁軸２５は、該弁軸２５の上部小径部２５ｂに外挿され、かつ、弁軸ホルダ３２の天井部と弁軸２５における下部大径部２５ａの上端段丘面との間に縮装された圧縮コイルばねからなる閉弁ばね３４によって、常時下方（閉弁方向）に付勢されている。弁軸ホルダ３２の天井部上でプッシュナット３３の外周には、コイルばねからなる復帰ばね３５が設けられている。 The valve shaft 25 is extrapolated to the upper small diameter portion 25b of the valve shaft 25, and is contracted between the ceiling portion of the valve shaft holder 32 and the upper terrace surface of the lower large diameter portion 25a of the valve shaft 25. The valve closing spring 34 composed of a mounted compression coil spring is always urged downward (in the valve closing direction). A return spring 35 formed of a coil spring is provided on the outer periphery of the push nut 33 on the ceiling portion of the valve shaft holder 32.

前記ガイドブッシュ２６には、前記ロータ３０が所定の閉弁位置まで回転下降せしめられた際、それ以上の回転下降を阻止するための回転下降ストッパ機構の一方を構成する下ストッパ体（固定ストッパ）２７が固着され、弁軸ホルダ３２には前記ストッパ機構の他方を構成する上ストッパ体（移動ストッパ）３７が固着されている。 The guide bush 26 has a lower stopper body (fixed stopper) that constitutes one of rotation lowering stopper mechanisms for preventing further rotation lowering when the rotor 30 is rotated and lowered to a predetermined valve closing position. 27 is fixed, and an upper stopper body (moving stopper) 37 constituting the other of the stopper mechanism is fixed to the valve shaft holder 32.

なお、前記閉弁ばね３４は、弁体部２４が弁口２２ａに着座する閉弁状態において所要のシール圧を得るため（漏れ防止）、及び、弁体部２４が弁口２２ａに衝接した際の衝撃を緩和するために配備されている。 The valve closing spring 34 obtains a required sealing pressure in a closed state where the valve body 24 is seated on the valve port 22a (leakage prevention), and the valve body 24 is in contact with the valve port 22a. Deployed to mitigate impact.

このような構成とされた電動弁１０’にあっては、ステータ５０に第１態様で通電励磁パルスを供給することにより、弁本体２０に固定されたガイドブッシュ２６に対し、ロータ３０及び弁軸ホルダ３２が一方向に回転せしめられ、ねじ部２８、３８のねじ送りにより、例えば弁軸ホルダ３２が下方に移動して弁体部２４が弁口２２ａに押し付けられて弁口２２ａが閉じられる。 In the motor-operated valve 10 ′ configured as described above, the rotor 30 and the valve shaft are connected to the guide bush 26 fixed to the valve body 20 by supplying the energization excitation pulse to the stator 50 in the first mode. The holder 32 is rotated in one direction, and by screw feed of the screw portions 28 and 38, for example, the valve shaft holder 32 moves downward, the valve body portion 24 is pressed against the valve port 22a, and the valve port 22a is closed.

弁口２２ａが閉じられた時点では、上ストッパ体３７は未だ下ストッパ体２７に衝接しておらず、弁体部２４が弁口２２ａを閉じたままロータ３０及び弁軸ホルダ３２はさらに回転下降する。この場合、弁軸２５（弁体部２４）は下降しないが、弁軸ホルダ３２は下降するため、閉弁ばね３４が所定量圧縮せしめられ、その結果、弁体部２４が弁口２２ａに強く押し付けられるとともに、弁軸ホルダ３２の回転下降により、上ストッパ体３７が下ストッパ体２７に衝接し、その後ステータコイル５３，５３に対するパルス供給が続行されても弁軸ホルダ３２の回転下降は強制的に停止される（全閉状態）。 When the valve port 22a is closed, the upper stopper body 37 is not yet in contact with the lower stopper body 27, and the rotor 30 and the valve shaft holder 32 are further rotated and lowered while the valve body portion 24 is closed. To do. In this case, the valve shaft 25 (valve body portion 24) does not descend, but the valve shaft holder 32 descends, so that the valve closing spring 34 is compressed by a predetermined amount. As a result, the valve body portion 24 is strongly against the valve port 22a. The upper stopper body 37 comes into contact with the lower stopper body 27 by the lowering of the rotation of the valve shaft holder 32, and the lowering of the valve shaft holder 32 is forced even if the pulse supply to the stator coils 53, 53 is continued thereafter. Is stopped (fully closed).

一方、この全閉状態からステータ５０に第２態様で通電励磁パルスを供給すると、弁本体２０に固定されたガイドブッシュ２６に対し、ロータ３０及び弁軸ホルダ３２が前記と逆方向に回転せしめられ、ねじ部２８、３８のねじ送りにより、今度は弁軸ホルダ３２が上方に移動する。この場合、弁軸ホルダ３２の回転上昇開始時点（パルス供給開始時点）では、閉弁ばね３４が前記のように所定量圧縮せしめられているので、閉弁ばね３４が前記所定量分伸長するまでは、前記弁体部２４が弁口２２ａからは離れず閉弁状態（リフト量＝０）のままである。そして、閉弁ばね３４が前記所定量分伸長した後、弁軸ホルダ３２がさらに回転上昇せしめられると、前記弁体部２４が弁口２２ａから離れて弁口２２ａが開かれ、冷媒が弁口２２ａを通過する。 On the other hand, when the energization excitation pulse is supplied to the stator 50 from the fully closed state in the second mode, the rotor 30 and the valve shaft holder 32 are rotated in the opposite direction to the guide bush 26 fixed to the valve body 20. The valve shaft holder 32 is now moved upward by the screw feed of the screw portions 28 and 38. In this case, since the valve closing spring 34 is compressed by a predetermined amount as described above at the time when the rotation of the valve shaft holder 32 starts to rise (when pulse supply starts), until the valve closing spring 34 is extended by the predetermined amount. The valve body 24 does not leave the valve port 22a and remains in the closed state (lift amount = 0). Then, after the valve closing spring 34 is extended by the predetermined amount, when the valve shaft holder 32 is further rotated up, the valve body portion 24 is separated from the valve port 22a, the valve port 22a is opened, and the refrigerant is supplied to the valve port. Pass 22a.

この場合、ロータ３０の回転量により弁体部２４のリフト量、言い換えれば、弁口２２ａの実効開口面積（＝弁開度）を任意に細かく調整することができ、ロータ３０の回転量は供給パルス数により制御されるため、冷媒流量を高精度に制御することができる。 In this case, the lift amount of the valve body 24, in other words, the effective opening area (= valve opening degree) of the valve port 22a can be arbitrarily finely adjusted by the rotation amount of the rotor 30, and the rotation amount of the rotor 30 is supplied. Since it is controlled by the number of pulses, the refrigerant flow rate can be controlled with high accuracy.

したがって、かかる構成の電動弁１０’を前記ヒートポンプ式冷暖房システムに逆止弁付き膨張弁に代えて組み込む場合には、冷媒が一方向に流されるとき（例えば冷房運転時）は、圧力損失を可及的に低減すべく最大開度（最大リフト量）とされ、冷媒が他方向に流されるとき（例えば暖房運転時）は、流量制御を行なうべくその開度（リフト量）を所定値以下の特定範囲で細かく制御するようにされる（詳細は下記特許文献２を参照）。 Therefore, when the motor-operated valve 10 ′ having such a configuration is incorporated in the heat pump type air conditioning system in place of the expansion valve with a check valve, pressure loss is allowed when the refrigerant flows in one direction (for example, during cooling operation). The maximum opening (maximum lift amount) is set to be reduced as much as possible, and when the refrigerant is flowed in the other direction (for example, during heating operation), the opening (lift amount) is set to a predetermined value or less to perform flow control. Fine control is performed within a specific range (for details, refer to Patent Document 2 below).

特開２０１０−２４９２４６号公報JP 2010-249246 A 特開２００９−１４０５６号公報JP 2009-14056 A

ところで、電気自動車（ＥＶ）やプラグインハイブリッド車（ＰＨＶ）等に配備されるヒートポンプ式冷暖房システム（カーエアコン）では、車室を冷房する以外に搭載バッテリを冷却する必要もあって、冷房運転時と暖房運転時のいずれも冷媒が一方向（同方向）に流されるため、前記従来例の電動弁１０’のように、冷媒が冷房運転時と暖房運転時とでは逆方向に流されるシステム用に作られた電動弁では対応できないおそれがある。 By the way, in a heat pump type air conditioning system (car air conditioner) installed in an electric vehicle (EV), a plug-in hybrid vehicle (PHV), etc., it is necessary to cool the mounted battery in addition to cooling the passenger compartment. Since the refrigerant flows in one direction (same direction) both during the heating operation and the heating operation, for the system in which the refrigerant flows in the opposite direction during the cooling operation and the heating operation as in the motor-operated valve 10 ′ of the conventional example. There is a possibility that the motorized valve made in the above cannot cope.

また、前記従来例の電動弁１０’では、小流量時の流量制御精度の向上と制御可能流量の増大化とは二律背反するものとなる。すなわち、弁口の口径（実効開口面積）が図示例のままであると、小流量時の流量制御精度は高くできるが、システム中に流す冷媒の流量（制御可能流量）を増大させようとすると、弁開度を最大にしても弁口部分が抵抗となって圧力損失が大きくなり、逆に、弁口の口径を大きくすると制御可能流量の増大化・圧力損失の低減化は図れるものの、小流量時の流量制御精度が低下する。 In the conventional motor-operated valve 10 ', the improvement in the flow rate control accuracy at a small flow rate and the increase in the controllable flow rate are contradictory. That is, if the diameter of the valve port (effective opening area) remains as in the illustrated example, the flow rate control accuracy at a small flow rate can be increased, but if the flow rate of refrigerant flowing through the system (controllable flow rate) is to be increased. However, even if the valve opening is maximized, the pressure at the valve port becomes resistance and the pressure loss increases. Conversely, increasing the valve port diameter increases the controllable flow rate and reduces the pressure loss. The flow control accuracy at the time of flow decreases.

本発明は、上記事情に鑑みてなされたもので、その目的とするところは、流体（冷媒）が一方向に流されるもとで、小流量時の流量制御精度の向上と制御可能流量の増大化・圧力損失の低減化の両方を効果的に図ることのできる電動弁を提供することにある。 The present invention has been made in view of the above circumstances, and its object is to improve flow control accuracy at a small flow rate and increase a controllable flow rate while a fluid (refrigerant) flows in one direction. It is to provide an electric valve that can effectively achieve both reduction of pressure and reduction of pressure loss.

前記の目的を達成すべく、本発明に係る電動弁は、基本的には、弁軸と、該弁軸を昇降させるためのロータ、ステータ、送りねじ等からなる昇降駆動機構と、下から順に第１弁口、弁室、及び第２弁口が設けられた弁本体とを備え、前記弁軸の下部に、前記第１弁口を開閉するための第１弁体が軸方向に相対移動可能な状態で配在され、かつ、該第１弁体の前記弁軸に対する下動限界位置を定める第１係止部材が設けられるとともに、前記第１弁体を前記第１係止部材側に付勢する第１ばね部材が設けられ、前記弁軸における前記第１弁体より上側に、前記第２弁口を開閉するための第２弁体が軸方向に相対移動可能な状態で配在され、かつ、該第２弁体の前記弁軸に対する上動限界位置を定める第２係止部材が設けられるとともに、前記第２弁体を前記第２係止部材側に付勢する第２ばね部材が設けられ、前記第１弁口及び第２弁口のうちの一方は実効開口面積が小、他方は実効開口面積が大とされ、前記弁軸が最下降位置から所定位置へ上昇するまでは、前記第１弁体が前記第１弁口を閉じるとともに、前記第２弁体が前記第２弁口の開度を変化させ、前記弁軸を前記所定位置からさらに上昇させると、前記第２弁体が前記第２弁口を閉じるとともに、前記第１弁体が前記第１弁口の開度を変化させるように構成されていることを特徴としている。 In order to achieve the above object, the motor-operated valve according to the present invention basically includes a valve shaft, an elevating drive mechanism composed of a rotor, a stator, a feed screw and the like for elevating the valve shaft, and in order from the bottom. And a valve body provided with a first valve port, a valve chamber, and a second valve port, and a first valve body for opening and closing the first valve port is relatively moved in the axial direction below the valve shaft. A first locking member that is arranged in a possible state and that defines a lower limit position of the first valve body relative to the valve shaft is provided, and the first valve body is disposed on the first locking member side. A first spring member to be urged is provided, and a second valve body for opening and closing the second valve port is disposed above the first valve body in the valve shaft in a state in which the second valve body is relatively movable in the axial direction. And a second locking member that defines an upper movement limit position of the second valve body with respect to the valve shaft is provided, and A second spring member that biases the valve body toward the second locking member is provided, and one of the first valve port and the second valve port has a small effective opening area, and the other has a large effective opening area. The first valve body closes the first valve port and the second valve body changes the opening of the second valve port until the valve shaft rises from the lowest position to a predetermined position. When the valve shaft is further raised from the predetermined position, the second valve body closes the second valve port and the first valve body changes the opening degree of the first valve port. It is characterized by being.

好ましい態様では、前記第１弁体及び第２弁体のうちの、実効開口面積が小の弁口を開閉する方の弁体がニードル型とされ、実効開口面積が大の弁口を開閉する方の弁体がポペット型とされる。 In a preferred embodiment, of the first valve body and the second valve body, a valve body that opens and closes a valve opening with a small effective opening area is a needle type, and opens and closes a valve opening with a large effective opening area. The valve body on the side is a poppet type.

他の好ましい態様では、前記弁室に流入口が開口せしめられ、前記第１弁口に連なって第１流出口が設けられるとともに、前記第２弁口に連なって第２流出口が設けられる。 In another preferred embodiment, an inflow port is opened in the valve chamber, a first outflow port is provided to be connected to the first valve port, and a second outflow port is provided to be connected to the second valve port.

この場合、好ましい態様では、前記第１流出口の下流側が盲蓋で閉塞されるとともに、前記第１流出口と第２流出口とが連通路を介して連通せしめられる。 In this case, in a preferred embodiment, the downstream side of the first outlet is closed with a blind cover, and the first outlet and the second outlet are communicated with each other via a communication path.

本発明に係る電動弁は、より具体的には、弁軸と、該弁軸を昇降させるためのロータ、ステータ、送りねじ等からなる昇降駆動機構と、下から順に、実効開口面積が小の第１弁口、弁室、及び実効開口面積が大の第２弁口が設けられた弁本体とを備え、前記弁軸の下部に、前記第１弁口を開閉するためのニードル型の第１弁体が軸方向に相対移動可能な状態で配在され、かつ、該第１弁体の前記弁軸に対する下動限界位置を定める第１係止部材が設けられるとともに、前記第１弁体を前記第１係止部材側に付勢する第１ばね部材が設けられ、前記弁軸における前記第１弁体より上側に、前記第２弁口を開閉するためのポペット型の第２弁体が軸方向に相対移動可能な状態で配在され、かつ、該第２弁体の前記弁軸に対する上動限界位置を定める第２係止部材が設けられるとともに、前記第２弁体を前記第２係止部材側に付勢する第２ばね部材が設けられ、前記弁軸が最下降位置から所定位置へ上昇するまでは、前記第１弁体が前記第１弁口を閉じるとともに、前記第２弁体が前記第２弁口の開度を変化させる大流量制御状態をとり、前記弁軸を前記所定位置からさらに上昇させると、前記第２弁体が前記第２弁口を閉じるとともに、前記第１弁体が前記第１弁口の開度を変化させる小流量制御状態をとるように構成されていることを特徴としている。 More specifically, the motor-operated valve according to the present invention has a valve shaft, an elevating drive mechanism including a rotor, a stator, a feed screw, and the like for elevating the valve shaft, and an effective opening area in order from the bottom. A valve body having a first valve port, a valve chamber, and a second valve port having a large effective opening area, and a needle-type second for opening and closing the first valve port at a lower portion of the valve shaft. The first valve body is disposed in a state in which the one valve body is relatively movable in the axial direction, and a first locking member is provided for determining a lower limit position of the first valve body relative to the valve shaft, and the first valve body A first spring member for urging the first valve member toward the first locking member, and a poppet-type second valve body for opening and closing the second valve port above the first valve body in the valve shaft. Are arranged in a state in which relative movement is possible in the axial direction, and the upper movement limit position of the second valve body with respect to the valve shaft is determined. A second locking member is provided, and a second spring member for urging the second valve body toward the second locking member is provided, until the valve shaft rises from the lowest position to a predetermined position. The first valve body closes the first valve port, and the second valve body takes a large flow rate control state in which the opening degree of the second valve port is changed, and the valve shaft is further raised from the predetermined position. Then, the second valve body closes the second valve port, and the first valve body is configured to take a small flow rate control state in which the opening degree of the first valve port is changed. It is said.

本発明に係る電動弁では、弁軸が最下降位置から所定位置へ上昇するまでは、第１弁体が第１弁口を閉じるとともに、第２弁体が第２弁口の開度を変化させる大流量制御状態をとり、弁軸を所定位置からさらに上昇させると、第２弁体が第２弁口を閉じるとともに、第１弁体が第１弁口の開度を変化させる小流量制御状態をとるようにされているので、冷媒が一方向に流されるもとで、小流量時の流量制御精度の向上と制御可能流量の増大化・圧力損失の低減化の両方を効果的に図ることができる。 In the electric valve according to the present invention, the first valve body closes the first valve port and the second valve body changes the opening degree of the second valve port until the valve shaft rises from the lowest position to the predetermined position. Small flow rate control in which the second valve body closes the second valve opening and the first valve body changes the opening degree of the first valve opening when the valve shaft is further raised from a predetermined position. Since the refrigerant is flown in one direction, both the improvement of the flow control accuracy at a small flow rate, the increase of the controllable flow rate, and the reduction of the pressure loss are effectively achieved. be able to.

本発明に係る電動弁の一実施例における第１の動作状態を示す主要部拡大断面図。The principal part expanded sectional view which shows the 1st operation state in one Example of the motor operated valve which concerns on this invention. 本発明に係る電動弁の一実施例における第２の動作状態を示す主要部拡大断面図。The principal part expanded sectional view which shows the 2nd operation state in one Example of the motor operated valve which concerns on this invention. 本発明に係る電動弁の一実施例における第３の動作状態を示す主要部拡大断面図。The principal part expanded sectional view which shows the 3rd operation state in one Example of the motor operated valve which concerns on this invention. 図１に示される電動弁における冷媒流量（開度）とパルス数（回転量）との関係の一例を示す図。The figure which shows an example of the relationship between the refrigerant | coolant flow volume (opening) and the number of pulses (rotation amount) in the motor operated valve shown in FIG. 従来の電動弁の一例を示す縦断面図。The longitudinal cross-sectional view which shows an example of the conventional motor operated valve.

以下、本発明の実施形態を図面を参照しながら説明する。
図１、図２、図３は、本発明に係る電動弁の一実施例を示す主要部拡大断面図であり、各図は異なる動作状態を示している。図示実施例の電動弁１０のステータ（ステッピングモータ）５０部分は、図５に示される従来例の電動弁１０’のものとほぼ同じであるので、該部分は省略している。また、従来例の電動弁１０’のモータ部分以外の各部に対応する部分には同一の符号を付して重複説明を省略し、以下は、主要部（特徴部分）である弁軸の下部及び弁本体を中心に説明する。 Embodiments of the present invention will be described below with reference to the drawings.
1, 2, and 3 are enlarged cross-sectional views of a main part showing an embodiment of a motor-operated valve according to the present invention, and each drawing shows different operating states. The stator (stepping motor) 50 portion of the motor-operated valve 10 of the illustrated embodiment is substantially the same as that of the motor-operated valve 10 ′ of the conventional example shown in FIG. Further, parts corresponding to the respective parts other than the motor part of the motor-driven valve 10 ′ of the conventional example are denoted by the same reference numerals, and redundant description will be omitted. The description will focus on the valve body.

図示実施例の電動弁１０は、大流量化を図るべく、従来例の電動弁１０’の弁本体２０より大きな直方体状の弁本体１５を備えている。該弁本体１５の中央には、それを縦貫するように上から順に、段付き穴１４、弁室２１、小口径（実効開口面積が小）の第１弁口２２ａ付き第１弁座２２、第１流出口１２が設けられている。 The motor-operated valve 10 of the illustrated embodiment includes a rectangular parallelepiped valve body 15 larger than the valve body 20 of the motor-operated valve 10 'of the conventional example in order to increase the flow rate. In the center of the valve body 15, in order from the top so as to pass through the valve body 15, a stepped hole 14, a valve chamber 21, a first valve seat 22 with a first valve port 22 a having a small diameter (effective opening area is small) A first outlet 12 is provided.

前記段付き穴１４は、上から順に、大径嵌合穴部１４ａ、中間空所１４ｂ、小径嵌合穴部１４ｃからなり、大径嵌合穴部１４ａには前記従来例の電動弁１０’における弁本体２０の上部に相当するブッシュ保持体１８が圧入等により内嵌固定され、中間空所１４ｂの側部には第２流出口１３が開口せしめられ、小径嵌合穴部１４ｃには、大口径（実効開口面積が大）の第２弁口２３ａ付き第２弁座２３が圧入等により内嵌固定されている。 The stepped hole 14 includes, in order from the top, a large-diameter fitting hole 14a, an intermediate space 14b, and a small-diameter fitting hole 14c. The large-diameter fitting hole 14a includes the electric valve 10 ′ of the conventional example. The bush holding body 18 corresponding to the upper part of the valve body 20 is fitted and fixed by press fitting or the like, the second outlet 13 is opened at the side of the intermediate space 14b, and the small diameter fitting hole 14c has A second valve seat 23 with a second valve port 23a having a large diameter (large effective opening area) is fitted and fixed by press-fitting or the like.

前記弁室２１は、その下部に、前記第１弁座２２を底部とする段付きの小径下部室２１ｂが延設されており、また、弁室２１の側部には流入口１１が開口せしめられている。 The valve chamber 21 is provided with a stepped small-diameter lower chamber 21b with the first valve seat 22 at the bottom, and the inlet 11 is opened at the side of the valve chamber 21. It has been.

前記第１流出口１２の下部は、圧入、螺合等により盲蓋１９が固着されて閉塞されており、また、第１流出口１２と第２流出口１３とは連通路１６を介して連通せしめられている。 The lower part of the first outlet 12 is closed by a blind cover 19 fixed by press fitting, screwing or the like, and the first outlet 12 and the second outlet 13 communicate with each other via a communication path 16. I'm hurt.

一方、前記弁軸２５の下部には、段付き円筒状の弁体収容室４３が設けられている。この弁体収容室４３には、前記第１弁座２２に離接して第１弁口２２ａを開閉するためのニードル型の鍔状部４４ａ付き第１弁体４４（以下、ニードル弁体４４と称す）が軸方向に相対移動可能な状態で配在され、また、弁体収容室４３の下部には、前記ニードル弁体４４（の鍔状部４４ａ）を抜け止め係止する、言い換えれば、該ニードル弁体４４の弁軸２５に対する下動限界位置を定めるスリーブ状の第１係止部材４６が圧入等により内嵌固定されている。 On the other hand, a stepped cylindrical valve body accommodating chamber 43 is provided at the lower portion of the valve shaft 25. The valve body accommodating chamber 43 includes a first valve body 44 with a needle-shaped hook-shaped portion 44a (hereinafter referred to as a needle valve body 44) for opening and closing the first valve port 22a while being separated from and contacting the first valve seat 22. And the needle valve body 44 (the hook-shaped portion 44a) is secured to the lower portion of the valve body housing chamber 43, in other words, A sleeve-like first locking member 46 that determines a lower limit position of the needle valve body 44 relative to the valve shaft 25 is fitted and fixed by press fitting or the like.

また、弁体収容室４３の天井部４３ａとニードル弁体４４（の鍔状部４４ａ）との間には、ニードル弁体４４を下向きに付勢する第１コイルばね６１が縮装されている。さらに、弁軸２５が図１に示される位置まで下降した際には、弁軸２５の上部に配在された閉弁ばね３４（図５参照）の付勢力により、弁体収容室４３の肩部（段差部）４３ｂがニードル弁体４４の鍔状部４４ａ上面外周に当接してそれを押圧するようになっている。 A first coil spring 61 that biases the needle valve body 44 downward is provided between the ceiling 43a of the valve body storage chamber 43 and the needle valve body 44 (the hook-shaped portion 44a). . Further, when the valve shaft 25 is lowered to the position shown in FIG. 1, the shoulder of the valve body accommodating chamber 43 is urged by the urging force of the valve closing spring 34 (see FIG. 5) disposed on the upper portion of the valve shaft 25. The portion (stepped portion) 43b comes into contact with and presses the outer periphery of the upper surface of the flange-shaped portion 44a of the needle valve body 44.

前記弁軸２５における弁体収容室４３より上側には、前記第２弁座２３に離接して第２弁口２３ａを開閉するためのポペット型（円形厚板状）の第２弁体４５（以下、ポペット弁体４５と称す）が軸方向に相対移動可能な状態で外挿され、また、弁軸２５におけるポペット弁体４５より上側には、該ポペット弁体４５の前記弁軸２５に対する上動限界位置を定めるスリーブ状の第２係止部材４７が圧入等により外嵌固定されている。また、弁軸２５における弁体収容室４３の上部外周に設けられた弁軸鍔状部４８とポペット弁体４５との間には、ポペット弁体４５を上向きに付勢する第２コイルばね６２が縮装されている。 A poppet-type (circular thick plate-shaped) second valve body 45 (opening and closing the second valve port 23a by opening and closing the second valve seat 23 on the valve shaft 25 above the valve body housing chamber 43 ( (Hereinafter referred to as a poppet valve body 45) is inserted in an axially movable state, and above the poppet valve body 45 in the valve shaft 25, the poppet valve body 45 is located above the valve shaft 25. A sleeve-like second locking member 47 for defining the movement limit position is fitted and fixed by press fitting or the like. Further, a second coil spring 62 that urges the poppet valve body 45 upward is provided between the valve shaft flange 48 provided on the outer periphery of the valve body housing chamber 43 in the valve shaft 25 and the poppet valve body 45. Is being disguised.

また、前記弁軸鍔状部４８と弁室２１下部に設けられた段付きの小径下部室２１ｂの段丘面部（段差部）２１ｃとの間には、ねじ部２８、３８からなる送りねじのバックラッシュ（遊び）を無くすべく、弁軸２５を上向きに付勢する圧縮コイルばね６３が縮装されている。 Further, between the valve shaft flange 48 and the terrace surface portion (step portion) 21c of the stepped small-diameter lower chamber 21b provided at the lower portion of the valve chamber 21, a back of the feed screw including the screw portions 28 and 38 is provided. In order to eliminate rush (play), a compression coil spring 63 that biases the valve shaft 25 upward is contracted.

このような構成とされた本実施例の電動弁１０にあっては、従来例の電動弁１０’と同様に、ステータ５０に通電励磁パルスを供給することにより、ガイドブッシュ２６に対し、ロータ３０及び弁軸ホルダ３２が回転しながら昇降せしめられ、それに伴って弁軸２５が昇降せしめられる。この場合、ロータ３０の回転量はステータ５０への供給パルス数に応じたものとなるため、上記バルス数（回転量）により、弁軸２５・弁体４４、４５の昇降位置、すなわち、該電動弁１０を通過する冷媒流量を制御することができる。 In the motor-operated valve 10 of the present embodiment having such a configuration, the rotor 30 is applied to the guide bush 26 by supplying an energizing excitation pulse to the stator 50 as in the motor-operated valve 10 ′ of the conventional example. The valve shaft holder 32 is raised and lowered while rotating, and the valve shaft 25 is raised and lowered accordingly. In this case, since the amount of rotation of the rotor 30 depends on the number of pulses supplied to the stator 50, the lifted position of the valve shaft 25 and the valve bodies 44, 45, that is, the electric motor is driven by the number of pulses (rotation amount). The flow rate of the refrigerant passing through the valve 10 can be controlled.

以下、本実施例の電動弁１０の動作を、冷媒流量（開度）とパルス数（回転量）との関係の一例を示す図４を参照しながら説明する。 Hereinafter, the operation of the motor-operated valve 10 of this embodiment will be described with reference to FIG. 4 showing an example of the relationship between the refrigerant flow rate (opening degree) and the number of pulses (rotation amount).

ここでは、図１に示される状態は、第１弁口２２ａが閉、第２弁口２３ａが開の状態（パルス数（回転量）が０の状態）であり、図２に示される状態は、第１弁口２２ａ及び第２弁口２３ａが共に閉の状態、図３に示される状態は、第１弁口２２ａが開、第２弁口２３ａが閉の状態である。 Here, the state shown in FIG. 1 is a state where the first valve port 22a is closed and the second valve port 23a is opened (a state where the number of pulses (rotation amount) is 0), and the state shown in FIG. The first valve port 22a and the second valve port 23a are both closed, and the state shown in FIG. 3 is a state where the first valve port 22a is open and the second valve port 23a is closed.

図１に示されるパルス数（回転量）が０の状態では、弁軸２５及びニードル弁体４４が最下降位置まで下降せしめられており（図５に示された上ストッパ体３７が下ストッパ体２７に衝接して下降が停止された状態）、弁軸２５の上部に配在された閉弁ばね３４の付勢力により、弁体収容室４３の肩部（段差部）４３ｂがニードル弁体４４の鍔状部４４ａ上面外周に当接してそれを押圧し、ニードル弁体４４が第１弁座２２に強く押し付けられ、第１弁口２２ａは全閉状態とされる。 When the number of pulses (rotation amount) shown in FIG. 1 is 0, the valve shaft 25 and the needle valve body 44 are lowered to the lowest position (the upper stopper body 37 shown in FIG. 5 is the lower stopper body). 27, the lowering of the valve shaft 25 is stopped, and the shoulder (stepped portion) 43b of the valve body housing chamber 43 is moved to the needle valve body 44 by the urging force of the valve closing spring 34 disposed on the upper portion of the valve shaft 25. The needle valve body 44 is strongly pressed against the first valve seat 22, and the first valve port 22a is fully closed.

一方、ポペット弁体４５は第２係止部材４７に当接係止された上動限界位置にあり、第２弁座２３から下方に大きく離れており、第２弁口２３ａは全開状態とされる。したがって、この状態では、冷媒は入出口１１→弁室２１→第２弁口２３ａ→中間空所１４ｂ→第２流出口１３へと流れ、その流量は最大のＦｃ（大流量）となる。 On the other hand, the poppet valve body 45 is in the upper movement limit position abutted and locked to the second locking member 47, and is greatly separated downward from the second valve seat 23, and the second valve port 23a is fully opened. The Therefore, in this state, the refrigerant flows from the inlet / outlet 11 → the valve chamber 21 → the second valve port 23 a → the intermediate space 14 b → the second outlet 13, and the flow rate becomes the maximum Fc (large flow rate).

上記図１に示される状態からパルス数を増加させていくと、パルス数がＴｉになるまでは、弁軸２５の上昇に合わせてポペット弁体４５が第２弁座２３に近づけられ、第２弁口２３ａの冷媒流量（開度）が一定の下り勾配をもって滑らかに減少していく。このパルス数が０からＴｉになるまでは、弁軸２５は所定位置（図２に示される位置）まで上昇するが、ニードル弁体４４は第１コイルばね６１の付勢力により第１弁座２２に押し付けられており、第１弁口２２ａは閉じられたままである。 When the number of pulses is increased from the state shown in FIG. 1, the poppet valve body 45 is brought closer to the second valve seat 23 as the valve shaft 25 rises until the number of pulses reaches Ti. The refrigerant flow rate (opening degree) of the valve port 23a smoothly decreases with a constant downward gradient. Until the number of pulses changes from 0 to Ti, the valve shaft 25 rises to a predetermined position (position shown in FIG. 2). However, the needle valve body 44 is moved to the first valve seat 22 by the urging force of the first coil spring 61. The first valve port 22a remains closed.

そして、パルス数がＴｉになると、図２に示されるようにポペット弁体４５が第２弁座２３に接当して第２弁口２３ａが閉じられる。ここで、パルス数がＴｉからＴｊの間の期間は、ニードル弁体４４の鍔状部４４ａと第１係止部材４６との間に隙間βが残っているので（図２参照）、ニードル弁体４４は引き上げられない。したがって、パルス数がＴｉからＴｊになるまでは、第１弁口２２ａ及び第２弁口２３は共に閉じられており、冷媒流量（開度）は０となる。 When the pulse number becomes Ti, the poppet valve body 45 comes into contact with the second valve seat 23 and the second valve port 23a is closed as shown in FIG. Here, since the gap β remains between the flange 44a of the needle valve body 44 and the first locking member 46 during the period between the number of pulses Ti and Tj (see FIG. 2), the needle valve The body 44 cannot be pulled up. Therefore, until the pulse number changes from Ti to Tj, both the first valve port 22a and the second valve port 23 are closed, and the refrigerant flow rate (opening) becomes zero.

続いて、パルス数をＴｊから増加させていくと、図３に示されるようにニードル弁体４４の鍔状部４４ａに第１係止部材４６が接当して、弁軸２５の上昇に合わせてニードル弁体４４が引き上げられ、第１弁口２２ａが開かれ、冷媒は流入口１１→弁室２１→第１弁口２２ａ→第１流出口１２→連通路１６→第２流出口１３へと流れる。このときは、第１弁口２２ａの冷媒流量（開度）が一定の緩やかな上り勾配をもって滑らかに増大していくので、流量をきめ細かく制御することができる。なお、パルス数をＴｊから増加させて弁軸２５を上昇させると、第２コイルばね６２が圧縮されてポペット弁体４５は第２弁座２３に強く押し付けられる（第２弁口２３ａは閉じたまま）。 Subsequently, when the number of pulses is increased from Tj, the first locking member 46 comes into contact with the flange 44a of the needle valve body 44 as shown in FIG. The needle valve body 44 is pulled up, the first valve port 22a is opened, and the refrigerant flows from the inlet 11 to the valve chamber 21 to the first valve port 22a to the first outlet 12 to the communication passage 16 to the second outlet 13. And flow. At this time, the flow rate (opening) of the refrigerant at the first valve port 22a increases smoothly with a constant gradual upward gradient, so that the flow rate can be finely controlled. When the number of pulses is increased from Tj to raise the valve shaft 25, the second coil spring 62 is compressed and the poppet valve body 45 is strongly pressed against the second valve seat 23 (the second valve port 23a is closed). Leave).

以上のように、本実施例の電動弁１０においては、小口径の第１弁口２２ａをニードル弁体４４で開閉するとともに、大口径の第２弁口２３ａをポペット弁体４５で開閉するようにされ、かつ、弁軸２５が最下降位置（図１に示される位置）から所定位置（図２に示される位置）へ上昇するまでは、ニードル弁体４４により第１弁口２２ａが閉じられるとともに、第２弁口２３の流量（開度）がポペット弁体４５によりリニヤに制御される大流量制御状態をとり、弁軸２５を前記所定位置からさらに上昇させると、ポペット弁体４５により第２弁口２３ａが閉じられるとともに、第１弁口２２ａの流量（開度）がニードル弁体４４によりリニヤに制御される小流量制御状態をとるようにされているので、冷媒が一方向に流されるもとで、小流量時の流量制御精度の向上と制御可能流量の増大化・圧力損失の低減化の両方を効果的に図ることができる。 As described above, in the motor-operated valve 10 according to the present embodiment, the first valve port 22a having a small diameter is opened and closed by the needle valve body 44, and the second valve port 23a having a large diameter is opened and closed by the poppet valve body 45. The first valve port 22a is closed by the needle valve body 44 until the valve shaft 25 rises from the lowest lowered position (position shown in FIG. 1) to a predetermined position (position shown in FIG. 2). At the same time, when the flow rate (opening) of the second valve port 23 is linearly controlled by the poppet valve body 45 and the valve shaft 25 is further raised from the predetermined position, the poppet valve body 45 Since the two valve ports 23a are closed and the flow rate (opening degree) of the first valve port 22a is linearly controlled by the needle valve body 44, the refrigerant flows in one direction. In a small stream It is possible to both reduce the increase of the flow rate control accuracy and increased reduction and pressure loss of a controllable flow rate of the effective.

なお、上記実施例において、盲蓋１９及び連通路１６を省いて、小流量時は、冷媒を第２流出口１３を介することなく第１流出口１２より流すようにしてもよい。 In the above embodiment, the blind lid 19 and the communication path 16 may be omitted, and the refrigerant may be flowed from the first outlet 12 without passing through the second outlet 13 at a small flow rate.

また、パルス数がＴiからＴjに至るまでは第１弁口２２ａ及び第２弁口２３ａは、両方共に閉じるものとして説明したが、上記ＴiからＴjに至るまでの間においても、第１弁口２２ａ及び第２弁口２３ａは共に開いたままの構成とすることも可能である。 In addition, the first valve port 22a and the second valve port 23a are both closed until the pulse number reaches Ti to Tj. However, the first valve port may also be closed between Ti and Tj. Both 22a and the second valve port 23a can be configured to remain open.

１０電動弁
１１流入口
１２第１流出口
１３第２流出口
１５弁本体
１６連通路
１９盲蓋
２１弁室
２２第１弁座
２２ａ第１弁口
２３第２弁座
２３ａ第２弁口
２５弁軸
３０ロータ
４０キャン
４３弁体収容室
４４ニードル弁体（第１弁体）
４５ポペット弁体（第２弁体）
４６第１係止部材
４７第２係止部材
５０ステータ
６１第１コイルばね
６２第２コイルばね DESCRIPTION OF SYMBOLS 10 Motorized valve 11 Inflow port 12 1st outflow port 13 2nd outflow port 15 Valve main body 16 Communication path 19 Blind lid 21 Valve chamber 22 1st valve seat 22a 1st valve port 23 2nd valve seat 23a 2nd valve port 25 Valve Shaft 30 Rotor 40 Can 43 Valve body storage chamber 44 Needle valve body (first valve body)
45 Poppet valve body (second valve body)
46 First locking member 47 Second locking member 50 Stator 61 First coil spring 62 Second coil spring

Claims

弁軸と、該弁軸を昇降させるためのロータ、ステータ、送りねじ等からなる昇降駆動機構と、下から順に第１弁口、弁室、及び第２弁口が設けられた弁本体とを備え、
前記弁軸の下部に、前記第１弁口を開閉するための第１弁体が軸方向に相対移動可能な状態で配在され、かつ、該第１弁体の前記弁軸に対する下動限界位置を定める第１係止部材が設けられるとともに、前記第１弁体を前記第１係止部材側に付勢する第１ばね部材が設けられ、
前記弁軸における前記第１弁体より上側に、前記第２弁口を開閉するための第２弁体が軸方向に相対移動可能な状態で配在され、かつ、該第２弁体の前記弁軸に対する上動限界位置を定める第２係止部材が設けられるとともに、前記第２弁体を前記第２係止部材側に付勢する第２ばね部材が設けられ、
前記第１弁口及び第２弁口のうちの一方は実効開口面積が小、他方は実効開口面積が大とされ、前記弁軸が最下降位置から所定位置へ上昇するまでは、前記第１弁体が前記第１弁口を閉じるとともに、前記第２弁体が前記第２弁口の開度を変化させ、前記弁軸を前記所定位置からさらに上昇させると、前記第２弁体が前記第２弁口を閉じるとともに、前記第１弁体が前記第１弁口の開度を変化させるように構成された電動弁。 A valve shaft, a lifting drive mechanism including a rotor, a stator, a feed screw, and the like for moving the valve shaft up and down, and a valve body provided with a first valve port, a valve chamber, and a second valve port in order from the bottom Prepared,
A first valve body for opening and closing the first valve port is disposed at a lower portion of the valve shaft so as to be relatively movable in the axial direction, and a lower limit of the first valve body relative to the valve shaft A first locking member for determining the position, and a first spring member for biasing the first valve body toward the first locking member;
A second valve body for opening and closing the second valve port is disposed above the first valve body in the valve shaft so as to be relatively movable in the axial direction, and the second valve body A second locking member for determining an upper movement limit position with respect to the valve shaft is provided, and a second spring member for biasing the second valve body toward the second locking member is provided,
One of the first valve port and the second valve port has a small effective opening area, and the other has a large effective opening area. Until the valve shaft rises from the lowest position to a predetermined position, the first When the valve body closes the first valve port, the second valve body changes the opening of the second valve port, and when the valve shaft is further raised from the predetermined position, the second valve body is A motor-operated valve configured to close the second valve port and cause the first valve body to change an opening degree of the first valve port.

前記第１弁体及び第２弁体のうちの、実効開口面積が小の弁口を開閉する方の弁体がニードル型とされ、実効開口面積が大の弁口を開閉する方の弁体がポペット型とされていることを特徴とする請求項１に記載の電動弁。 Of the first valve body and the second valve body, a valve body that opens and closes a valve opening having a small effective opening area is a needle type, and a valve body that opens and closes a valve opening having a large effective opening area. The motor-operated valve according to claim 1, wherein the valve is a poppet type.

前記弁室に流入口が開口せしめられ、前記第１弁口に連なって第１流出口が設けられるとともに、前記第２弁口に連なって第２流出口が設けられていることを特徴とする請求項１又は２に記載の電動弁。 An inflow port is opened in the valve chamber, a first outflow port is provided to be connected to the first valve port, and a second outflow port is provided to be connected to the second valve port. The motor-operated valve according to claim 1 or 2.

前記第１流出口の下流側が盲蓋で閉塞されるとともに、前記第１流出口と第２流出口とが連通路を介して連通せしめられていることを特徴とする請求項３に記載の電動弁。 4. The electric motor according to claim 3, wherein a downstream side of the first outlet is closed with a blind cover, and the first outlet and the second outlet are communicated with each other via a communication path. valve.

弁軸と、該弁軸を昇降させるためのロータ、ステータ、送りねじ等からなる昇降駆動機構と、下から順に、実効開口面積が小の第１弁口、弁室、及び実効開口面積が大の第２弁口が設けられた弁本体とを備え、
前記弁軸の下部に、前記第１弁口を開閉するためのニードル型の第１弁体が軸方向に相対移動可能な状態で配在され、かつ、該第１弁体の前記弁軸に対する下動限界位置を定める第１係止部材が設けられるとともに、前記第１弁体を前記第１係止部材側に付勢する第１ばね部材が設けられ、
前記弁軸における前記第１弁体より上側に、前記第２弁口を開閉するためのポペット型の第２弁体が軸方向に相対移動可能な状態で配在され、かつ、該第２弁体の前記弁軸に対する上動限界位置を定める第２係止部材が設けられるとともに、前記第２弁体を前記第２係止部材側に付勢する第２ばね部材が設けられ、
前記弁軸が最下降位置から所定位置へ上昇するまでは、前記第１弁体が前記第１弁口を閉じるとともに、前記第２弁体が前記第２弁口の開度を変化させる大流量制御状態をとり、前記弁軸を前記所定位置からさらに上昇させると、前記第２弁体が前記第２弁口を閉じるとともに、前記第１弁体が前記第１弁口の開度を変化させる小流量制御状態をとるように構成された電動弁。 A valve shaft, a lifting drive mechanism composed of a rotor, a stator, a feed screw and the like for raising and lowering the valve shaft, and a first valve port having a small effective opening area, a valve chamber, and a large effective opening area in order from the bottom. A valve body provided with a second valve opening,
A needle-type first valve body for opening and closing the first valve port is disposed at a lower portion of the valve shaft so as to be relatively movable in the axial direction, and the first valve body with respect to the valve shaft A first locking member for defining a lower movement limit position is provided, and a first spring member for biasing the first valve body toward the first locking member is provided,
A poppet type second valve body for opening and closing the second valve port is disposed above the first valve body in the valve shaft so as to be relatively movable in the axial direction, and the second valve A second locking member for determining an upper movement limit position of the body relative to the valve shaft is provided, and a second spring member for biasing the second valve body toward the second locking member is provided,
The first valve body closes the first valve port and the second valve body changes the opening degree of the second valve port until the valve shaft rises from the lowest position to a predetermined position. When the control state is taken and the valve shaft is further raised from the predetermined position, the second valve body closes the second valve port and the first valve body changes the opening degree of the first valve port. Motorized valve configured to take a small flow control state.