JP2004316718A

JP2004316718A - Electric operated valve

Info

Publication number: JP2004316718A
Application number: JP2003109226A
Authority: JP
Inventors: Hidekazu Sasada; 英一笹田
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2003-04-14
Filing date: 2003-04-14
Publication date: 2004-11-11
Anticipated expiration: 2023-04-14
Also published as: JP4230806B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric operated valve miniaturized in the whole of shape and accurately controlling opening/closing of a main valve. <P>SOLUTION: A main valve main body 60 and an auxiliary valve main body 20 are integrally structured with each other, and the main valve main body 60 is provided with a main valve element 63 for controlling flow rate of the refrigerant, and the auxiliary valve main body 20 is provided with an auxiliary valve element 23 for controlling opening/closing of the main valve element 63. The auxiliary valve main body 20 is provided with a can 40 having a built-in rotor 30 for operating the auxiliary valve element 23, and a stator 50 fitted on the can 40 to rotate the rotor 30. The main valve main body 60 controls passing flow rate of the refrigerant with the main valve element 63 to be brought in contact and separated with/from a main valve seat 62 inside a main valve chamber 61. Namely, opening of the main valve element 63 to be similarly opened/closed in response to opening/closing of the auxiliary valve element 23 is increased/decreased by increasing/decreasing the back pressure of the main valve element 63 with the auxiliary valve element 23. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、空気調和機、冷凍機等に組み込まれて使用される電動弁に係り、特に小型化が可能で、小さい駆動力で正確に開閉可能なパイロット弁付きの電動弁に関する。
【０００２】
【従来の技術】
従来、この種の空気調和機、冷凍機等に組み込まれて使用される電動弁は、冷媒等の流体の流量を制御する機器であり、通常、弁室および弁座を備えた弁本体と、鍔状部を介して前記弁本体の上部に固着された有底円筒状のキャンとを備えており、該キャンの内側にはロータが内蔵され、前記キャンの外部には中央部に挿通孔を有するステータが外嵌されているものである。
【０００３】
図９は前記した公知の特許文献１に示された電動弁の縦断面図を示しており、電動弁１の弁本体２は、弁室２ｃと、ガイドブッシュ固定部２ｄと、キャン固着部２ｅとを備え、弁室２ｃには冷媒等の流体が出入する流体流入管２ａ、流体流出管２ｂが設けられるとともに、その内部には弁軸３の先端に形成された弁体３ａであるニードル弁が接離する弁座２ｆが配設されている。
【０００４】
前記ガイドブッシュ固定部２ｄは、弁室の上方に位置し、弁本体２とガイドブッシュ４とを固定する。該ガイドブッシュ４の内周には雌ねじ部４ａが形成され、該雌ねじ部４ａには弁軸ホルダ５の外周に形成された雄ねじ部５ａが螺合され、雌ねじ部と雄ねじ部とによりねじ送り機構が構成されている。そして、この弁軸ホルダ５内には、下端部に弁体３ａを形成している弁軸３が摺動可能に嵌挿されており、該弁軸３は弁軸ホルダ５内に縮装された圧縮コイルばね３ｂによって常時下方に付勢されている。
【０００５】
キャン固着部２ｅは弁本体２の上端に位置し、内周面をかしめ固定されるとともに下端面を溶接により接合されているリング状金属板で構成され、その外周部にてキャン６の鍔状部と溶接され弁本体２にキャン６を固定している。弁軸３とロータ７との結合は、弁軸３に弁軸ホルダ５と一体成形されるスリーブ５ｄを外嵌させるとともに、これを永久磁石付きのロータ７に内嵌させることによって行われている。弁軸３の上端にはプッシュナット３ｃが圧入固定され、その鍔部が弁軸３に若干の上下動を許容してロータ７に結合している。また、弁軸３およびロータ７の上方移動の最上限は、ロータ７の上部に設けられているばね７ｂとキャン６の内面との接触によって行われる。弁軸ホルダ５に固定される下ストッパ４ｂとスリーブ５ｄに形成される上ストッパ５ｂとによりストッパ機構が構成される。
【０００６】
キャン６の内部にはロータ７が内蔵され、キャン６の外部にはステータ８が外嵌されている。ステータ８の内部には上下にステータコイル８ａおよびヨーク８ｂが格納されており、ステータコイル８ａはリード線８ｃおよびステータ８の外周に設けられたコネクタ８ｄを通じて通電される。ステータコイル８ａの通電によりヨーク８ｂが励磁されてロータ７を回転させ、ねじ送り機構により弁軸ホルダ５と弁軸３を摺動させることにより弁体３ａを開閉作動させて冷媒流量の制御を行っている。ステータ８にはコネクタのカバー８ｅが接着されている。
【０００７】
ステータ８の下方に金属製のリング状の取付板９を固定し、この取付板９と一体に形成された回り止め片９ａを、弁本体２から水平方向に突出する流体流入管２ａに係合させるとともに、弁本体２とキャン６とのリング状溶接部の一辺に係合孔９ｂを係合させ、リング状溶接部の他辺には取付板９と一体に形成された押圧片９ｃを押圧させてステータ８を固定している。
【０００８】
【特許文献１】特願２００１−５０４１５号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、従来技術に係る前記電動弁は、弁体を開閉するための大きな開閉力を要し、そのために、ステ−タ等からなる弁体駆動部が大形になり易いという問題があった。
【００１０】
したがって、本発明はこのような問題に鑑みてなされたものであって、その目的とするところは、全体形状の小形化と、主弁の開閉度を正確にコントロールできる電動弁を提供することにある。
【００１１】
【課題を解決するための手段】
前記目的を達成すべく、本発明に係る電動弁は、下記の構成を具備する。即ち、
請求項１記載の電動弁は、主弁本体と副弁本体とを一体に構成し、前記副弁本体に形成された副弁座に副弁体を接離させることにより、主弁本体に設けられた主弁体の流量を制御させることを特徴とする電動弁。
かかる特徴により、副弁体を主弁体のパイロット弁とすることで、小流量の副弁体の開閉により、大流量の主弁体を開閉する電動弁とすることができる。
【００１２】
請求項２記載の電動弁は、主弁体と該主弁体の流量を制御する副弁体とを具備し、該副弁体の流路断面積の変化に、主弁体の流路断面積の変化を正比例させることを特徴とする。
かかる特徴により、副弁体の流量制御により、主弁体の流量を容易に制御することができる。
【００１３】
請求項３記載の電動弁は、請求項１又は請求項２記載の電動弁において、主弁本体と副弁本体とを一体に構成し、前記主弁本体は主弁室内の主弁座に接離して冷媒の流量を制御する主弁体を具備し、前記副弁本体は副弁室内の副弁座に接離して冷媒の流量を制御する副弁体を具備し、前記主弁体の開度の増減は、副弁体による主弁体の背圧の増減によって行われることを特徴とする。
かかる特徴により、簡単な構成で主弁体の流量を制御することができる。
請求項４記載の電動弁は、請求項３記載の電動弁において、上記副弁本体は、前記副弁体を作動させるステッピングモータを備えていることを特徴とする。
かかる特徴により、ステッピングモータの回転に対して主弁体の流量を容易に制御することができる。
【００１４】
請求項５記載の電動弁は、請求項１乃至請求項４記載のいずれかの電動弁において、上記主弁体の上部に被ガイド部を形成させ、上記副弁本体の下部にガイド部を形成させ、上記被ガイド部の上下動を上記ガイド部により案内させることを特徴とする。
かかる特徴により、簡単な構成で主弁体の横ぶれを防止することができる。
【００１５】
請求項６記載の電動弁は、請求項３記載の電動弁において、上記主弁体に径大部を形成すると共に、該径大部にテーパ部を形成し、該テーパ部と上記主弁室内壁との隙間を上記主弁室から上記副弁室への流路として形成し、前記主弁体の上動により前記流路の面積が増大するように構成されることを特徴とする。
請求項７記載の電動弁は、請求項３記載の電動弁において、上記主弁体に径大部を形成すると共に、該径大部に対応する上記主弁室内壁部分にテーパ部を形成し、該テーパ部と上記主弁体の径大部外周面との隙間を上記主弁室から上記副弁室への流路として形成し、前記主弁体の上動により前記流路の面積が増大するように構成されることを特徴とする。
請求項８記載の電動弁は、請求項３記載の電動弁において、上記主弁体に径大部を形成すると共に、該径大部に略一定幅のスリットテーパ部を形成し、該スリットテーパ部と上記主弁室内壁との隙間を上記主弁室から上記副弁室への流路として形成し、前記主弁体の上動により前記流路の面積が増大するように構成されることを特徴とする。
請求項９記載の電動弁は、請求項３記載の電動弁において、上記主弁体に径大部を形成すると共に、該径大部に一定深さの定深さスリット部を形成し、該定深さスリット部と上記主弁室内壁との隙間を上記主弁室から上記副弁室への流路として形成し、前記主弁体の上動により前記流路の面積が増大するように構成されることを特徴とする。
かかる請求項６乃至請求項９のいずれかの特徴により、副弁体の流量制御が確実になり、その結果、主弁体における流量制御が正確となる。
請求項１０記載の電動弁は、請求項１乃至請求項９記載のいずれかの電動弁において、上記主弁体の流量を上記副弁体の流量に相似的に変化させることを特徴とする。
かかる特徴により、上記主弁体と上記副弁体との開閉度を相似形とすることが可能となる。
【００１６】
【実施形態１】
実施形態１に係る電動弁１０は、主弁室６１内の弁座６２に接離する主弁体６３により冷媒の通過流量を制御する主弁本体６０と、主弁本体６０に設けられた副弁本体２０に固着され副弁体２３を作動させるロータ３０を内蔵するキャン４０と、該キャン４０に外嵌されロータ３０を回転駆動するステータ５０と主弁本体６０のパイロット弁として副弁室２１内の副弁座２２に接離して主弁体６３の開閉度を制御する副弁体２３と、を備えている。前記主弁体６３の開度の増減は、副弁体２３による主弁体６３の背圧の増減によって行われる。なお、ロータ３０とステータ５０によりステッピングモータを構成している。
【００１７】
キャン４０は、ステンレス等の非磁性の金属から形成される有底円筒状をしており、副弁本体２０の上部に固着されたステンレス製の鍔状板４１に溶接等により固着され、内部は気密状態に保たれている。ステータ５０は磁性材より構成されるヨーク５１と、このヨーク５１にボビン５２を介して巻回される上下のステータコイル５３とから構成され、キャン４０に外嵌する嵌合穴５０ａが形成されている。なお、ステータ５０は中心に下面開口の嵌合穴５０ａを有し、この嵌合穴にキャン４０が嵌合し、キャン４０に固定される。
【００１８】
副弁体２３は黄銅製の弁軸２４の下端に形成されている。副弁体２３を副弁座２２に接離させる駆動機構は、副弁本体２０よりロータ３０方向に延出して固定され、固定ねじ部２５が形成される筒状のガイドブッシュ２６と、該ガイドブッシュ２６の固定ねじ部２５に螺合する移動ねじ部３１を有する弁軸ホルダ３２とから構成されるねじ送り機構であり、前記ねじ送り機構をロータ３０内の軸方向全長の略中央部に配置している。
【００１９】
固定ねじ部２５はガイドブッシュ２６の外周に雄ねじで構成され、移動ねじ部３１は弁軸ホルダ３２の内周に雌ねじで構成されている。なお、ガイドブッシュ２６および弁軸ホルダ３２は、ともに黄銅製の円筒状材から形成されている。
【００２０】
弁軸ホルダ３２はガイドブッシュ２６の外側に位置する下方開口の円筒状をしており、前記のように内面に移動ねじ部３１が形成してあり、弁軸ホルダ３２の中心に弁軸２４の上部縮径部が嵌合してプッシュナット３３により連結されている。副弁体２３を下端に形成した弁軸２４は黄銅より構成され、弁軸ホルダ３２の中心に上下動可能に嵌挿されており、弁軸ホルダ３２内に縮装された圧縮コイルばね３４によって常時下方に付勢されている。ガイドブッシュ２６の側面には副弁室２１とキャン４０内の均圧を図る均圧孔３２ａが形成してある。
【００２１】
弁軸２４の上端に圧入固定されたプッシュナット３３の外周に円筒状の圧縮コイルばねで構成される復帰ばね３５を取付け、ガイドブッシュ２６の固定ねじ部２５と弁軸ホルダ３２の移動ねじ部３１との螺合が外れたときに、復帰ばね３５がキャン４０の内面に当接して固定ねじ部２５と移動ねじ部３１との螺合を復帰させるように付勢する。復帰ばね３５はプッシュナット３３の外周に緩く嵌合して載置した状態で取付けてもよく、またプッシュナット３３の外周に弾接するように取付けてもよい。
【００２２】
副弁本体２０は黄銅等の金属から構成され、キャン４０との接合は、副弁本体２０に溶接等により固着された鍔状板４１の段差部にキャンの端部を突き合わせ溶接することにより行っている。なお、突き合わせ溶接に限らず、キャン４０の端部を外周に平坦に折り曲げて鍔状部として形成し、この鍔状部と鍔状板４１とをいわゆる拝み溶接により固定するようにしてもよい。
副弁本体２０の上部にはガイドブッシュ２６が連結・固定されており、その下部には副弁室２１が形成され、該副弁室２１内に、弁軸２４の下部が配置される。また、前記副弁室２１の底部は副弁座２２を構成している。また、副弁本体２０の下部外周部には雄ねじ部２０ａが形成されると共に、副弁本体２０の下部は下方に延設されガイド部２０ｂが形成される。また、該ガイド部２０ｂ内空間と前記副弁室２１とは連通流入孔２１ａにより連通しており、副弁座２２の下部には下部副弁室２１ｂが形成され、該下部副弁室２１ｂは後述の連通流出孔６０ｄに連通している。
【００２３】
弁軸ホルダ３２とロータ３０とは支持リング３６を介して結合されており、支持リング３６は実施形態１ではロータ３０の成形時にインサートされた黄銅製の金属リングで構成されている。支持リング３６の内周孔部に弁軸ホルダ３２の上部突部が嵌合し、上記突部の外周をかしめ固定してロータ３０、支持リング３６および弁軸ホルダ３２を結合している。副弁本体２０、弁軸２４、ガイドブッシュ２６、弁軸ホルダ３２、支持リング３６は、前記したように全て黄銅より構成し、リサイクルを考慮した構成としている。
さらに、それぞれの部品は圧入・かしめで結合されているので、たとえば、弁軸ホルダ３２と支持リング３６のかしめを除去することでロータを再利用することができる。なお、黄銅以外の金属、例えば、ステンレスを用いることができるのは勿論である。
【００２４】
ガイドブッシュ２６には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が固着されており、下ストッパ体２７はリング状のプラスチックより構成され、その上方には板状の下ストッパ片２７ａが突設されている。また、弁軸ホルダ３２には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が固着されており、上ストッパ体３７もリング状のプラスチックより構成され、下方に向けて板状の上ストッパ片３７ａが突設され、前記下ストッパ片２７ａと係合可能である。
【００２５】
下ストッパ体２７はガイドブッシュ２６の外周に形成された螺旋溝部分２６ａに射出成形により固着され、上ストッパ体３７は弁軸ホルダ３２の外周に形成された螺旋溝部分３２ｂに射出成形により固着されている。なお、下ストッパ体２７、上ストッパ体３７の固着は射出成形に限らず、接着や圧入等により固着してもよいのは勿論である。
【００２６】
主弁本体６０は、概略円柱状に形成され、その上部には副弁本体２０を装着するための取付凹部６０ｇが形成され、該取付凹部６０ｇの外周の上部には雌ねじ部６０ｃが形成される。また、上記取付凹部６０ｇの下部には、副弁本体２０側のガイド部２０ｂが嵌合されると共に、更にその下部には主弁室６１が形成される。そして、この主弁室６１の下部側方には流入孔６０ｅが形成され、また、この下部には下部主弁室６１ｂ及び該下部主弁室６１ｂに連通する流出孔６０ｆが形成される。そして、流入孔６０ｅには、流体流入管６０ａが装着され、流出孔６０ｆには流体流出管６０ｂが装着される。
更に、主弁本体６０には主弁室６１と並行して連通流出孔６０ｄが形成される。該連通流出孔６０ｄは、副弁座２２と流出孔６０ｆとを連通するものである。上記主弁本体６０の主弁室６１内部分には、径大部６３ｂが配置される。
【００２７】
上記主弁室６１内における主弁体６３の上下動により、流体流入管６０ａから流体流出管６０ｂに流れる冷媒量を無段階に調節することができる。即ち、主弁体６３は弁座６２に離接する主弁座当接部６３ａと、径大部６３ｂと、被ガイド部６３ｄとからなる。前記径大部６３ｂの下部には段部６３ｆが形成されると共に、外周にはテーパ部６３ｃが形成され、また、被ガイド部６３ｄには連通孔６３ｅが穿設される。なお、被ガイド部６３ｄは、ガイド部２０ｂの内面に上下に摺動可能に配置される。また、被ガイド部６３ｄ内で径大部６３ｂの上面と副弁本体２０の下面との間には主弁体６３を閉方向に弾圧するコイルばね６４が配置される。上記被ガイド部６３ｄをガイド部２０ｂにより案内させる構成は、必ずしも必要でないが、主弁体６３の振動（横移動）を防止することができる。
【００２８】
また、主弁体６３のテーパ部６３ｃと主弁本体６０の主弁室６１内壁との隙間で形成される流路断面積Ａ’は、副弁体２３の上下動に伴って形成される流路断面積ａの変化に比例するように主弁体６３は上下動する（Ａ’＝ｋ’ａ（ｋ’：定数））。上記流路断面積Ａ’は、テーパ部６３ｃのテーパ角度が一定なので主弁体６３のリフト量Ｌに略比例するとみなすことが出来る。したがって、
式Ｌ＝ｋａ（ｋ：定数）、または、Ａ’＝ｋ”Ｌ（ｋ”：定数）となる。
そして、副弁体２３の副弁座当接部２３ａの形状と主弁体６３の主弁座当接部６３ａの形状とは互いに略相似形に形成されると共に、弁軸２４の上下動と主弁体６３の上下動とは、相似的な位置となるように設計されることが望ましい。そして、その相似的な位置となるようにするためには、コイルばね６４のばね定数（弾発力）とテーパ部６３ｃの角度を考慮すればよい。
【００２９】
上記ステータ５０から、ステータコイル５３に接続された複数のリード端子５４が突出しており、このリード端子に複数のリード線５５が接続されたコネクタ５６が連結されている。そして、コネクタ５６を覆うカバー５７がステータ５０に溶着され、カバー５７内はシリコーン樹脂又はエポキシ樹脂等の充填材５８で充填されている。
【００３０】
前記の如く構成された電動弁１０の動作について説明する。
（開→閉）
ステッピングモータを構成するステータコイル５３に一方向の通電を行い励磁すると、副弁本体２０に固着されたガイドブッシュ２６に対しロータ３０および弁軸ホルダ３２が回転され、ガイドブッシュ２６の固定ねじ部２５と弁軸ホルダ３２の移動ねじ部３１とのねじ送り機構により、例えば弁軸ホルダ３２が下方に移動して副弁体２３が副弁座２２に着座圧接して弁口は閉じられる。
【００３１】
弁口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に当接しておらず、副弁体２３が弁口を閉じたままロータ３０および弁軸ホルダ３２はさらに回転下降する。このときは弁軸２４に対して弁軸ホルダ３２が下降するため、圧縮コイルばね３４が圧縮されることにより弁軸ホルダ３２の下降力は吸収される。その後ロータ３０がさらに回転して弁軸ホルダ３２が下降されると、上ストッパ体３７の上ストッパ片３７ａが下ストッパ体２７の下ストッパ片２７ａに当接し、ステータコイル５３に対する通電が続行されても弁軸ホルダ３２の下降は強制的に停止される。
【００３２】
上ストッパ体３７と下ストッパ体２７とから構成されるストッパ機構は、ロータ３０の軸方向の全長内に配置されているので、ストッパ機構が機能しているときでもロータ３０や弁軸ホルダ３２が大きく傾いたりすることが少なく作動が安定し、つぎにロータ３０を逆転するときでも円滑に行うことができる。
上記副弁座当接部２３ａの閉動作により、上記主弁本体６０の閉動作が行われる。即ち、副弁座当接部２３ａの閉動作分（減少分）に応じて、副弁本体２０を流れる量が減少し、その結果、連通流入孔２１ａを流れる量が減少し、上部主弁室６１ａの冷媒圧が上昇し、主弁体６３を下方、即ち、主弁体６３を閉方向に動作させる。
【００３３】
（閉→開）
ステータコイル５３に他方向の通電を行い励磁すると、副弁本体２０に固着されたガイドブッシュ２６に対しロータ３０および弁軸ホルダ３２が前記と逆方向に回転され、ガイドブッシュ２６の固定ねじ部２５と弁軸ホルダ３２の移動ねじ部３１とのねじ送り機構により、今度は弁軸ホルダ３２が上方に移動して弁軸２４の下端の副弁体２３が副弁座２２から離れて弁口が開かれ、冷媒は弁口を通過することができる。そして、ロータ３０の回転量により冷媒の通過量を制御することができ、ロータの回転量はパルス数にて規制されるため正確な制御を行うことができる。
【００３４】
このようにロータ３０が回転し、ガイドブッシュ２６の固定ねじ部２５と弁軸ホルダ３２の移動ねじ部３１とのねじ送り機構によりロータ３０、弁軸ホルダ３２および弁軸２４が軸方向に摺動するが、ねじ送り機構がロータ３０内の特に中央部に位置し、ロータ３０の支持および駆動がロータ３０の全長内で行われているため、回転時にロータ３０が振れることが少なく安定して回転させることができる。
【００３５】
そして、上記副弁座当接部２３ａの開動作により、上記主弁本体６０の開動作が行われる。即ち、副弁座当接部２３ａの開動作分（増加分）に応じて、副弁本体２０を流れる量が比例的に増大し、その結果、連通流入孔２１ａを流れる量が増大し、上部主弁室６１ａの冷媒圧が下降し、主弁体６３を上方、即ち、主弁体６３を開方向に動作させる。また、上記実施形態１の電動弁１０において、流体流入管６０ａから流入する冷媒圧が急激に高くなっても、その冷媒圧は段部６３ｆ及びテーパ部６３ｃに作用し、主弁体６３を瞬間的にコイルばね６４の弾発力及び上部主弁室６１ａの冷媒圧の力に抗して上動させることで、「開」とすることができ、電動弁１０及び冷凍サイクルの損傷を避けることができる。
【００３６】
【実施形態２】
次に、本発明の実施形態２について図４を用いて説明する。図４はその電動弁（閉状態）を示す縦断面図である。実施形態２の特徴は、上部主弁室６１ａの側壁面で、主弁体６３の均一外径で円柱状に形成された径大部６３ｂの外周部が対応する部分に、上部ほど径大となるテーパ部６１ｃが形成されるようにしたもので、実施形態１のテーパ部６３ｃが形成される場合と同様の効果が期待できる。
【００３７】
即ち、上記径大部６３ｂの周部と主弁本体６０の主弁室６１内壁を構成するテーパ部６１ｃとの隙間で形成される流路断面積Ａ’は、副弁体２３の上下動に伴って形成される流路断面積ａの変化に比例するように主弁体６３は上下動する（Ａ’＝ｋ’ａ（ｋ’：定数））。上記流路断面積Ａ’は、テーパ部６１ｃのテーパ角度が一定なので、主弁体６３のリフト量Ｌに略比例するとみなすことが出来、実施形態１と同様に、式Ｌ＝ｋａ（ｋ：定数）、または、Ａ’＝ｋ”Ｌ（ｋ”：定数）となる。
【００３８】
なお、実施形態２における上記以外の部分の構成は、実施形態１の場合と同一であることから、実施形態１を示す図１乃至図３に付した符号と同一符号を図４に付すことによってその説明を省略する。
【００３９】
【実施形態３】
次に、本発明の実施形態３について図５及び図６を用いて説明する。図５は本発明に係る実施形態３の電動弁（閉状態）を示す縦断面図、図６は同実施形態３の要部（主弁体６３）を示す縦断面図（Ａ）、及び、正面図（Ｂ）である。
実施形態３の特徴は、実施形態１のテーパ部６３ｃの形状に代えて、径大部６３ｂ外周の数箇所、例えば、２箇所に一定幅で下部位置ほど深くなるスリットテーパ部６３ｇを形成したもので、実施形態１の場合のテーパ部６３ｃを設けた場合と同様の効果が期待できる。
【００４０】
即ち、主弁体６３の径大部６３ｂ外周部（スリットテーパ部６３ｇを含む）と主弁本体６０の主弁室６１内壁との隙間で形成される流路断面積Ａ’は、副弁体２３の上下動に伴って形成される流路断面積ａの変化に比例するように主弁体６３は上下動する（Ａ’＝ｋ’ａ（ｋ’：定数）。上記流路断面積Ａ’は、スリットテーパ部６３ｇのテーパ角度が一定なので、主弁体６３のリフト量Ｌに略比例するとみなすことが出来、実施形態１と同様に、式Ｌ＝ｋａ（ｋ：定数）、または、Ａ’＝ｋ”Ｌ（ｋ”：定数）となる。
【００４１】
また、この実施形態３は、主弁体６３の径大部６３ｂの外周部（スリットテーパ部６３ｇ以外の部分）が主弁室６１内壁に摺接して支持・案内されるから、主弁体６３の上下動時の安定性が高い（左右の振れが少ない）という副次的効果がある。
なお、実施形態３における上記以外の構成は実施形態１の場合と同一であることから、実施形態１を示す図１乃至図３に付した符号と同一符号を図６，７に付すことによってその説明を省略する。
【００４２】
【実施形態４】
次に、本発明の実施形態４について図７及び図８を用いて説明する。図７は本発明に係る実施形態４の電動弁（閉状態）を示す縦断面図、図８は同実施形態４の要部を示す縦断面図（Ａ）、及び、正面図（Ｂ）である。
実施形態４の特徴は、実施形態１のテーパ部６３ｃの形状に代えて、径大部６３ｂの数箇所、例えば、２箇所に一定深さで下部位ほど幅広となる一定深さの定深さスリット部６３ｈを形成したもので、実施形態３の場合のスリットテーパ部６３ｇを設けた場合と同様の効果が期待できる。
【００４３】
即ち、主弁体６３の径大部６３ｂ外周部（定深さスリット部６３ｈを含む）と主弁本体６０の主弁室６１内壁との隙間で形成される流路断面積Ａ’は、副弁体２３の上下動に伴って形成される流路断面積ａの変化に比例するように主弁体６３は上下動する（Ａ’＝ｋ’ａ（ｋ’：定数）。上記流路断面積Ａ’は、定深さスリット部６３ｈの幅広となる角度が一定なので、主弁体６３のリフト量Ｌに略比例するとみなすことが出来、実施形態１と同様に、式Ｌ＝ｋａ（ｋ：定数）、または、Ａ’＝ｋ”Ｌ（ｋ”：定数）となる。
【００４４】
また、この実施形態４は、実施形態３と同様に、主弁体６３の径大部６３ｂの外周部が主弁室６１内壁に支持・案内されるから、主弁体６３の上下動時の安定性が高い（左右の振れが少ない）という副次的効果がある。
なお、実施形態４における上記以外の構成は実施形態１の場合と同一であることから、実施形態１を示す図１乃至図３に付した符号と同一符号を図７，８に付すことによってその説明を省略する。
【００４５】
なお、この発明は、冷凍サイクルにおいて設けられるエバポレータとエバポレータとの間の管路に用いてドライ運転用の流量制御弁としても使用できる。
【００４６】
【発明の効果】
以上の説明から理解できるように、本発明の電動弁は、主弁体の流量をパイロット弁の流量に正比例させることで、正確な制御が可能になる。また、小さな駆動部（ステッピングモータ）で、大流量の流量制御弁の正確な開閉に用いることができる。また、冷媒圧のショック高圧に対しても主弁体を逃がす（上動させる）ことで、流量の急変動に対応させることができる。
【図面の簡単な説明】
【図１】本発明に係る実施形態１の電動弁（閉状態）を示す縦断面図。
【図２】同実施形態１の電動弁の開閉の途中段階を示す縦断面図。
【図３】同実施形態１の電動弁（開状態）を示す縦断面図。
【図４】本発明に係る実施形態２の電動弁（閉状態）を示す縦断面図。
【図５】本発明に係る実施形態３の電動弁（閉状態）を示す縦断面図。
【図６】同実施形態３の要部を示す縦断面図（Ａ）、及び、正面図（Ｂ）。
【図７】本発明に係る実施形態４の電動弁（閉状態）を示す縦断面図。
【図８】同実施形態４の要部を示す縦断面図（Ａ）、及び、正面図（Ｂ）。
【図９】従来技術に係る電動弁の縦断面図。
【符号の説明】
１・・電動弁（公知例）２・・弁本体２ａ・・流体流入管
２ｂ・・流体流出管２ｃ・・弁室２ｄ・・ガイドブッシュ固定部
２ｅ・・キャン固着部２ｆ・・弁座３・・弁軸３ａ・・弁体
３ｂ・・圧縮コイルばね３ｃ・・プッシュナット
４・・ガイドブッシュ４ａ・・雌ねじ部４ｂ・・下ストッパ
５・・弁軸ホルダ５ａ・・雄ねじ部５ｂ・・上ストッパ
５ｄ・・スリーブ６・・キャン７・・ロータ７ｂ・・ばね
８・・ステータ８ａ・・ステータコイル８ｂ・・ヨーク
８ｃ・・リード線８ｄ・・コネクタ８ｅ・・カバー
９・・取付板９ａ・・回り止め片９ｂ・・係合孔９ｃ・・押圧片
１０・・電動弁（本発明）
２０・・副弁本体２０ａ・・雄ねじ部２０ｂ・・ガイド部
２１・・副弁室２１ａ・・連通流入孔２１ｂ・・下部副弁室
２２・・副弁座２３・・副弁体２３ａ・・副弁座当接部
２４・・弁軸２５・・固定ねじ部２６・・ガイドブッシュ
２６ａ・・螺旋溝部分２７・・下ストッパ体（固定ストッパ）
２７ａ・・下ストッパ片３０・・ロータ３１・・移動ねじ部
３２・・弁軸ホルダ３２ａ・・均圧孔
３２ｂ・・螺旋溝部分３３・・プッシュナット３４・・圧縮コイルばね
３５・・復帰ばね３６・・支持リング３７・・上ストッパ体（移動ストッパ）
３７ａ・・上ストッパ片４０・・キャン４１・・鍔状板
５０・・ステータ５０ａ・・嵌合穴５１・・ヨーク５２・・ボビン
５３・・ステータコイル５４・・リード端子５５・・リード線
５６・・コネクタ５７・・カバー５８・・充填材
６０・・主弁本体６０ａ・・流体流入管６０ｂ・・流体流出管
６０ｃ・・雌ねじ部６０ｄ・・連通流出孔
６０ｅ・・流入孔６０ｆ・・流出孔６０ｇ・・取付凹部
６１・・主弁室６１ａ・・上部主弁室６１ｂ・・下部主弁室
６１ｃ・・テーパ部（実施形態２）
６２・・弁座６３・・主弁体６３ａ・・主弁座当接部
６３ｂ・・径大部
６３ｃ・・テーパ部（実施形態１）６３ｄ・・被ガイド部６３ｅ・・連通孔
６３ｆ・・段部６３ｇ・・スリットテーパ部（実施形態３）
６３ｈ・・定深さスリット部（実施形態４）６４・・コイルばね[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor-operated valve that is used by being incorporated in an air conditioner, a refrigerator, and the like, and particularly to a motor-operated valve with a pilot valve that can be miniaturized and can be opened and closed accurately with a small driving force.
[0002]
[Prior art]
Conventionally, this type of air conditioner, an electric valve used by being incorporated in a refrigerator or the like is a device that controls the flow rate of a fluid such as a refrigerant, and usually includes a valve body having a valve chamber and a valve seat, A bottomed cylindrical can fixed to the upper part of the valve body via a flange portion, a rotor is built inside the can, and an insertion hole is provided at the center outside the can. Having an externally fitted stator.
[0003]
FIG. 9 is a longitudinal sectional view of the motor-operated valve disclosed in the above-mentioned known patent document 1. The valve body 2 of the motor-operated valve 1 includes a valve chamber 2c, a guide bush fixing portion 2d, and a can fixing portion 2e. The valve chamber 2c is provided with a fluid inflow pipe 2a and a fluid outflow pipe 2b through which a fluid such as a refrigerant flows in and out, and a needle valve as a valve body 3a formed at the tip of the valve shaft 3 inside thereof. A valve seat 2f is provided to contact and separate.
[0004]
The guide bush fixing portion 2 d is located above the valve chamber and fixes the valve body 2 and the guide bush 4. A female screw portion 4a is formed on the inner periphery of the guide bush 4, and a male screw portion 5a formed on the outer periphery of the valve shaft holder 5 is screwed to the female screw portion 4a, and a screw feed mechanism is formed by the female screw portion and the male screw portion. Is configured. In the valve shaft holder 5, a valve shaft 3 forming a valve body 3a at a lower end portion is slidably fitted. The valve shaft 3 is contracted into the valve shaft holder 5. The compression coil spring 3b is constantly biased downward.
[0005]
The can fixed portion 2 e is located at the upper end of the valve body 2, is formed by a ring-shaped metal plate which is fixed by caulking the inner peripheral surface and is joined at the lower end surface by welding. The can 6 is fixed to the valve body 2 by being welded to the portion. The connection between the valve shaft 3 and the rotor 7 is performed by externally fitting the sleeve 5d integrally formed with the valve shaft holder 5 to the valve shaft 3 and internally fitting the sleeve 5d to the rotor 7 with the permanent magnet. . A push nut 3 c is press-fitted and fixed to the upper end of the valve shaft 3, and its flange is coupled to the rotor 7 while allowing the valve shaft 3 to slightly move up and down. The upper limit of the upward movement of the valve shaft 3 and the rotor 7 is determined by the contact between the spring 7 b provided above the rotor 7 and the inner surface of the can 6. The lower stopper 4b fixed to the valve shaft holder 5 and the upper stopper 5b formed on the sleeve 5d constitute a stopper mechanism.
[0006]
A rotor 7 is built in the can 6, and a stator 8 is fitted outside the can 6. A stator coil 8a and a yoke 8b are stored inside and below the stator 8, and the stator coil 8a is energized through a lead wire 8c and a connector 8d provided on the outer periphery of the stator 8. The energization of the stator coil 8a excites the yoke 8b, rotates the rotor 7, and slides the valve shaft holder 5 and the valve shaft 3 by the screw feed mechanism to open and close the valve body 3a to control the refrigerant flow rate. ing. A connector cover 8e is adhered to the stator 8.
[0007]
A metal ring-shaped mounting plate 9 is fixed below the stator 8, and a detent piece 9 a formed integrally with the mounting plate 9 is engaged with a fluid inflow pipe 2 a projecting horizontally from the valve body 2. At the same time, an engagement hole 9b is engaged with one side of a ring-shaped welded portion between the valve body 2 and the can 6, and a pressing piece 9c formed integrally with the mounting plate 9 is pressed on the other side of the ring-shaped welded portion. Thus, the stator 8 is fixed.
[0008]
[Patent Document 1] Japanese Patent Application No. 2001-50415
[0009]
[Problems to be solved by the invention]
However, the electric valve according to the related art requires a large opening / closing force for opening / closing the valve body, and therefore, there is a problem that a valve body driving unit including a stator or the like tends to be large.
[0010]
Therefore, the present invention has been made in view of such a problem, and an object of the present invention is to provide a motor-operated valve that can reduce the overall shape and accurately control the opening / closing degree of a main valve. is there.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a motor-operated valve according to the present invention has the following configuration. That is,
The electric valve according to claim 1, wherein the main valve main body and the sub-valve main body are integrally formed, and the sub-valve body is brought into contact with and separated from a sub-valve seat formed in the sub-valve main body, thereby being provided on the main valve main body. An electric valve characterized by controlling a flow rate of a main valve body.
With such a feature, by using the sub-valve as the pilot valve of the main valve, a small-flow sub-valve can be opened and closed to open and close the large-flow main valve.
[0012]
The motor-operated valve according to claim 2 includes a main valve body and a sub-valve element for controlling a flow rate of the main valve body. It is characterized in that the change in the area is made directly proportional.
With this feature, the flow rate of the main valve body can be easily controlled by controlling the flow rate of the sub-valve body.
[0013]
According to a third aspect of the present invention, in the electric valve according to the first or second aspect, the main valve body and the sub-valve body are integrally formed, and the main valve body contacts a main valve seat in the main valve chamber. A main valve body that separates and controls the flow rate of the refrigerant; the sub-valve body includes a sub-valve body that controls the flow rate of the refrigerant by coming into contact with and separating from a sub-valve seat in the sub-valve chamber; The increase and decrease of the degree is performed by increasing and decreasing the back pressure of the main valve body by the sub-valve element.
With this feature, the flow rate of the main valve body can be controlled with a simple configuration.
An electric valve according to a fourth aspect is the electric valve according to the third aspect, wherein the sub-valve main body includes a stepping motor that operates the sub-valve element.
With such a feature, it is possible to easily control the flow rate of the main valve body with respect to the rotation of the stepping motor.
[0014]
According to a fifth aspect of the present invention, in the electric valve according to any one of the first to fourth aspects, a guided portion is formed at an upper portion of the main valve body, and a guide portion is formed at a lower portion of the sub-valve body. And the up-and-down movement of the guided portion is guided by the guide portion.
With such a feature, the main valve body can be prevented from running sideways with a simple configuration.
[0015]
According to a sixth aspect of the present invention, in the electric valve according to the third aspect, a large diameter portion is formed in the main valve body, a tapered portion is formed in the large diameter portion, and the tapered portion and the main valve chamber are formed. A gap with a wall is formed as a flow path from the main valve chamber to the sub-valve chamber, and the upward movement of the main valve body increases the area of the flow path.
A motor-operated valve according to claim 7 is the motor-operated valve according to claim 3, wherein a large-diameter portion is formed in the main valve body, and a tapered portion is formed in the main valve chamber inner wall portion corresponding to the large-diameter portion. The gap between the tapered portion and the outer peripheral surface of the large-diameter portion of the main valve body is formed as a flow path from the main valve chamber to the sub-valve chamber, and the area of the flow path is increased by the upward movement of the main valve body. It is characterized by being configured to increase.
The motor-operated valve according to claim 8 is the motor-operated valve according to claim 3, wherein the main valve body has a large-diameter portion, and the large-diameter portion has a slit taper portion having a substantially constant width. A gap between the portion and the main valve chamber wall is formed as a flow path from the main valve chamber to the sub-valve chamber, and the area of the flow path is increased by the upward movement of the main valve body. It is characterized by.
The motor-operated valve according to claim 9 is the motor-operated valve according to claim 3, wherein a large-diameter portion is formed in the main valve body, and a constant-depth slit portion having a constant depth is formed in the large-diameter portion. A gap between the constant depth slit portion and the main valve chamber wall is formed as a flow path from the main valve chamber to the sub-valve chamber, and the upward movement of the main valve body increases the area of the flow path. It is characterized by comprising.
According to the features of any one of the sixth to ninth aspects, the flow control of the sub-valve is ensured, and as a result, the flow control of the main valve is accurate.
An electric valve according to a tenth aspect is the electric valve according to any one of the first to ninth aspects, wherein the flow rate of the main valve body is changed similarly to the flow rate of the sub-valve body.
With such a feature, the opening and closing degrees of the main valve body and the sub-valve body can be made similar.
[0016]
Embodiment 1
The motor-operated valve 10 according to the first embodiment includes a main valve main body 60 that controls a flow rate of a refrigerant by a main valve body 63 that comes into contact with and separates from a valve seat 62 in a main valve chamber 61, and a sub valve provided in the main valve main body 60. A can 40 having a built-in rotor 30 that is fixed to the valve body 20 and operates the sub-valve element 23; a stator 50 that is fitted on the can 40 and that drives the rotor 30 to rotate; And a sub-valve 23 that controls the degree of opening and closing of the main valve body 63 by coming into contact with and separating from the sub-valve seat 22 therein. The opening degree of the main valve body 63 is increased or decreased by the back pressure of the main valve body 63 by the auxiliary valve body 23. In addition, the rotor 30 and the stator 50 constitute a stepping motor.
[0017]
The can 40 has a bottomed cylindrical shape formed of a non-magnetic metal such as stainless steel, and is fixed to a stainless steel flange plate 41 fixed to the upper part of the sub-valve main body 20 by welding or the like. It is kept airtight. The stator 50 is composed of a yoke 51 made of a magnetic material, and upper and lower stator coils 53 wound around the yoke 51 via a bobbin 52, and is formed with a fitting hole 50a that fits outside the can 40. I have. The stator 50 has a fitting hole 50a having a lower surface opening at the center, and the can 40 is fitted into the fitting hole and fixed to the can 40.
[0018]
The sub-valve 23 is formed at the lower end of a brass valve shaft 24. A drive mechanism for moving the sub-valve element 23 toward and away from the sub-valve seat 22 extends from the sub-valve body 20 in the direction of the rotor 30, is fixed, and has a cylindrical guide bush 26 in which a fixing screw portion 25 is formed; And a valve shaft holder 32 having a moving screw portion 31 to be screwed into the fixed screw portion 25 of the bush 26. The screw feeding mechanism is disposed at a substantially central portion of the rotor 30 in the entire axial direction. are doing.
[0019]
The fixing screw part 25 is formed by a male screw on the outer periphery of the guide bush 26, and the moving screw part 31 is formed by a female screw on the inner circumference of the valve shaft holder 32. The guide bush 26 and the valve shaft holder 32 are both formed of a cylindrical material made of brass.
[0020]
The valve shaft holder 32 has a cylindrical shape with a lower opening located outside the guide bush 26, and has the moving screw portion 31 formed on the inner surface as described above. The upper reduced diameter portion is fitted and connected by a push nut 33. The valve shaft 24 having the sub-valve body 23 formed at the lower end is made of brass, is fitted in the center of the valve shaft holder 32 so as to be vertically movable, and is compressed by a compression coil spring 34 compressed in the valve shaft holder 32. It is always biased downward. A pressure equalizing hole 32 a for equalizing the pressure in the sub-valve chamber 21 and the can 40 is formed on a side surface of the guide bush 26.
[0021]
A return spring 35 composed of a cylindrical compression coil spring is attached to the outer periphery of a push nut 33 press-fitted and fixed to the upper end of the valve shaft 24, and the fixed screw portion 25 of the guide bush 26 and the moving screw portion 31 of the valve shaft holder 32. Is released, the return spring 35 abuts against the inner surface of the can 40 and urges the fixed screw portion 25 and the movable screw portion 31 to return the screw engagement. The return spring 35 may be mounted in a state of being loosely fitted and mounted on the outer periphery of the push nut 33, or may be mounted so as to elastically contact the outer periphery of the push nut 33.
[0022]
The sub-valve body 20 is made of a metal such as brass, and is joined to the can 40 by butt-welding the end of the can to a step portion of a flange-shaped plate 41 fixed to the sub-valve body 20 by welding or the like. ing. Instead of butt welding, the end of the can 40 may be flatly bent to the outer periphery to form a flange, and the flange and the flange plate 41 may be fixed by so-called welding.
A guide bush 26 is connected and fixed to an upper portion of the sub-valve main body 20, and a sub-valve chamber 21 is formed at a lower portion of the guide bush 26. In the sub-valve chamber 21, a lower portion of a valve shaft 24 is disposed. The bottom of the sub-valve chamber 21 constitutes a sub-valve seat 22. A male screw portion 20a is formed on the outer peripheral portion of the lower portion of the sub-valve main body 20, and a lower portion of the sub-valve main body 20 extends downward to form a guide portion 20b. The space inside the guide portion 20b and the sub-valve chamber 21 communicate with each other through a communication inflow hole 21a. A lower sub-valve chamber 21b is formed below the sub-valve seat 22, and the lower sub-valve chamber 21b is It communicates with a communication outlet 60d described later.
[0023]
The valve shaft holder 32 and the rotor 30 are connected via a support ring 36. In the first embodiment, the support ring 36 is formed by a brass metal ring inserted when the rotor 30 is formed. The upper protrusion of the valve shaft holder 32 is fitted into the inner peripheral hole of the support ring 36, and the outer periphery of the protrusion is caulked and fixed to connect the rotor 30, the support ring 36 and the valve shaft holder 32. The sub-valve body 20, the valve shaft 24, the guide bush 26, the valve shaft holder 32, and the support ring 36 are all made of brass as described above, and have a structure considering recycling.
Further, since the components are press-fitted and caulked, the rotor can be reused, for example, by removing the caulking of the valve shaft holder 32 and the support ring 36. Of course, metals other than brass, for example, stainless steel can be used.
[0024]
A lower stopper body (fixed stopper) 27, which constitutes one of the stopper mechanisms, is fixed to the guide bush 26. The lower stopper body 27 is made of a ring-shaped plastic, and a plate-like lower stopper piece 27a is provided above the lower stopper body 27. Is protruding. An upper stopper body (movement stopper) 37, which constitutes the other of the stopper mechanisms, is fixed to the valve shaft holder 32. The upper stopper body 37 is also made of a ring-shaped plastic, and has a plate-shaped upper surface. A stopper piece 37a is protruded, and is engageable with the lower stopper piece 27a.
[0025]
The lower stopper body 27 is fixed to the spiral groove portion 26a formed on the outer periphery of the guide bush 26 by injection molding, and the upper stopper body 37 is fixed to the spiral groove portion 32b formed on the outer periphery of the valve shaft holder 32 by injection molding. ing. The fixing of the lower stopper body 27 and the upper stopper body 37 is not limited to injection molding.
[0026]
The main valve main body 60 is formed in a substantially columnar shape, and has a mounting recess 60g for mounting the sub-valve main body 20 formed on an upper portion thereof, and a female screw portion 60c formed on an outer peripheral upper portion of the mounting recess 60g. . A guide portion 20b on the side of the sub-valve body 20 is fitted into a lower portion of the mounting recess 60g, and a main valve chamber 61 is formed further below the guide portion 20b. An inflow hole 60e is formed at the lower side of the main valve chamber 61, and a lower main valve chamber 61b and an outflow hole 60f communicating with the lower main valve chamber 61b are formed below this. The fluid inlet pipe 60a is attached to the inlet hole 60e, and the fluid outlet pipe 60b is attached to the outlet hole 60f.
Further, a communication outflow hole 60 d is formed in the main valve main body 60 in parallel with the main valve chamber 61. The communication outlet hole 60d communicates between the sub-valve seat 22 and the outlet hole 60f. A large-diameter portion 63b is disposed in the main valve chamber 61 of the main valve body 60.
[0027]
The amount of refrigerant flowing from the fluid inflow pipe 60a to the fluid outflow pipe 60b can be continuously adjusted by the vertical movement of the main valve body 63 in the main valve chamber 61. That is, the main valve body 63 includes a main valve seat contact portion 63a that comes into contact with and separates from the valve seat 62, a large-diameter portion 63b, and a guided portion 63d. A step 63f is formed below the large diameter portion 63b, a tapered portion 63c is formed on the outer periphery, and a communication hole 63e is formed in the guided portion 63d. The guided portion 63d is disposed on the inner surface of the guide portion 20b so as to be slidable up and down. A coil spring 64 that resiliently presses the main valve body 63 in the closing direction is disposed between the upper surface of the large-diameter portion 63b and the lower surface of the sub-valve body 20 in the guided portion 63d. The configuration in which the guided portion 63d is guided by the guide portion 20b is not always necessary, but can prevent vibration (lateral movement) of the main valve body 63.
[0028]
In addition, a flow passage cross-sectional area A ′ formed by a gap between the tapered portion 63c of the main valve body 63 and the inner wall of the main valve chamber 61 of the main valve body 60 has a flow area formed by the vertical movement of the sub-valve body 23. The main valve body 63 moves up and down in proportion to the change in the road cross-sectional area a (A ′ = k′a (k ′: constant)). The flow path cross-sectional area A ′ can be considered to be substantially proportional to the lift amount L of the main valve body 63 since the taper angle of the tapered portion 63c is constant. Therefore,
Expression L = ka (k: constant) or A ′ = k ″ L (k ”: constant).
The shape of the sub-valve seat contact portion 23a of the sub-valve body 23 and the shape of the main valve seat contact portion 63a of the main valve body 63 are substantially similar to each other. The vertical movement of the main valve body 63 is desirably designed to be at a similar position. Then, in order to achieve the similar position, the spring constant (resilient force) of the coil spring 64 and the angle of the tapered portion 63c may be considered.
[0029]
A plurality of lead terminals 54 connected to the stator coil 53 protrude from the stator 50, and a connector 56 to which a plurality of lead wires 55 are connected is connected to the lead terminals. Then, a cover 57 covering the connector 56 is welded to the stator 50, and the inside of the cover 57 is filled with a filler 58 such as a silicone resin or an epoxy resin.
[0030]
The operation of the electric valve 10 configured as described above will be described.
(Open → Close)
When the stator coil 53 constituting the stepping motor is energized in one direction by excitation, the rotor 30 and the valve shaft holder 32 rotate with respect to the guide bush 26 fixed to the sub-valve main body 20, and the fixing screw portion 25 of the guide bush 26 is rotated. For example, the valve shaft holder 32 is moved downward by the screw feed mechanism of the valve shaft holder 32 and the moving screw portion 31 of the valve shaft holder 32, and the sub-valve 23 is seated and pressed against the sub-valve seat 22 to close the valve port.
[0031]
When the valve port is closed, the upper stopper body 37 has not yet contacted the lower stopper body 27, and the rotor 30 and the valve shaft holder 32 further rotate down while the sub-valve body 23 closes the valve port. At this time, since the valve shaft holder 32 is lowered with respect to the valve shaft 24, the compression force of the compression coil spring 34 absorbs the lowering force of the valve shaft holder 32. Thereafter, when the rotor 30 further rotates and the valve shaft holder 32 is lowered, the upper stopper piece 37a of the upper stopper body 37 abuts on the lower stopper piece 27a of the lower stopper body 27, and the energization of the stator coil 53 is continued. The lowering of the valve shaft holder 32 is also forcibly stopped.
[0032]
Since the stopper mechanism constituted by the upper stopper body 37 and the lower stopper body 27 is disposed within the entire length of the rotor 30 in the axial direction, the rotor 30 and the valve shaft holder 32 can be operated even when the stopper mechanism is functioning. The operation is stable with little inclination and the operation can be performed smoothly even when the rotor 30 is next rotated in the reverse direction.
The closing operation of the sub valve seat contact portion 23a causes the closing operation of the main valve body 60 to be performed. That is, in accordance with the closing operation (decrease) of the sub-valve seat contact portion 23a, the amount flowing through the sub-valve main body 20 decreases, and as a result, the amount flowing through the communication inflow hole 21a decreases, and the upper main valve chamber is reduced. The refrigerant pressure of 61a rises and moves the main valve body 63 downward, that is, moves the main valve body 63 in the closing direction.
[0033]
(Closed → open)
When the stator coil 53 is energized in the other direction to be excited, the rotor 30 and the valve shaft holder 32 rotate in the opposite direction to the guide bush 26 fixed to the sub-valve main body 20, and the fixing screw portion 25 of the guide bush 26 is rotated. The screw feed mechanism between the valve shaft holder 32 and the moving screw portion 31 of the valve shaft holder 32 causes the valve shaft holder 32 to move upward, the sub-valve element 23 at the lower end of the valve shaft 24 is separated from the sub-valve seat 22, and the valve port is opened. When opened, the refrigerant can pass through the valve port. The amount of refrigerant passing through can be controlled by the amount of rotation of the rotor 30. Since the amount of rotation of the rotor is regulated by the number of pulses, accurate control can be performed.
[0034]
Thus, the rotor 30 rotates, and the rotor 30, the valve shaft holder 32 and the valve shaft 24 slide in the axial direction by the screw feed mechanism of the fixing screw portion 25 of the guide bush 26 and the moving screw portion 31 of the valve shaft holder 32. However, since the screw feed mechanism is located particularly in the center of the rotor 30 and the rotor 30 is supported and driven within the entire length of the rotor 30, the rotor 30 is less likely to swing during rotation and is stably rotated. Can be done.
[0035]
Then, the opening operation of the main valve main body 60 is performed by the opening operation of the sub valve seat contact portion 23a. That is, in accordance with the opening operation (increase) of the sub-valve seat contact portion 23a, the amount flowing through the sub-valve main body 20 increases proportionally. As a result, the amount flowing through the communication inflow hole 21a increases. The refrigerant pressure in the main valve chamber 61a decreases, and the main valve body 63 is moved upward, that is, the main valve body 63 is operated in the opening direction. In the motor-operated valve 10 of the first embodiment, even if the pressure of the refrigerant flowing from the fluid inflow pipe 60a suddenly increases, the refrigerant pressure acts on the stepped portion 63f and the tapered portion 63c, causing the main valve body 63 to momentarily move. By moving upward against the resilient force of the coil spring 64 and the force of the refrigerant pressure in the upper main valve chamber 61a, it is possible to "open" and avoid damage to the electric valve 10 and the refrigeration cycle. Can be.
[0036]
Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a longitudinal sectional view showing the electric valve (closed state). The feature of the second embodiment is that the diameter of the upper main valve chamber 61a is larger on the side wall surface where the outer peripheral portion of the large-diameter portion 63b formed in a columnar shape with a uniform outer diameter of the main valve body 63 corresponds. Since the tapered portion 61c is formed, the same effect as when the tapered portion 63c of the first embodiment is formed can be expected.
[0037]
That is, the flow path cross-sectional area A ′ formed by the gap between the peripheral portion of the large-diameter portion 63b and the tapered portion 61c that forms the inner wall of the main valve chamber 61 of the main valve main body 60 changes with the vertical movement of the sub-valve element 23. The main valve body 63 moves up and down so as to be proportional to the change in the flow path cross-sectional area a (A ′ = k′a (k ′: constant)). Since the taper angle of the tapered portion 61c is constant, the flow path cross-sectional area A 'can be considered to be substantially proportional to the lift amount L of the main valve body 63. As in the first embodiment, the equation L = ka (k: A ′) or A ′ = k ″ L (k ″: constant).
[0038]
Since the configuration of the other parts in the second embodiment is the same as that in the first embodiment, the same reference numerals as in FIGS. 1 to 3 showing the first embodiment are assigned to FIG. The description is omitted.
[0039]
Embodiment 3
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view showing a motor-operated valve (closed state) of Embodiment 3 according to the present invention, FIG. 6 is a longitudinal sectional view (A) showing a main part (main valve body 63) of Embodiment 3, and It is a front view (B).
The feature of the third embodiment is that, instead of the shape of the tapered portion 63c of the first embodiment, a slit tapered portion 63g is formed at several locations on the outer periphery of the large-diameter portion 63b, for example, at two locations with a constant width and becoming deeper toward the lower position. Thus, the same effect as in the case of providing the tapered portion 63c in the first embodiment can be expected.
[0040]
That is, the flow path cross-sectional area A ′ formed by the gap between the outer peripheral portion (including the slit tapered portion 63g) of the large-diameter portion 63b of the main valve body 63 and the inner wall of the main valve chamber 61 of the main valve body 60 is equal to the auxiliary valve body. The main valve body 63 moves up and down in proportion to a change in the flow path cross-sectional area a formed with the vertical movement of 23 (A ′ = k′a (k ′: constant). 'Can be regarded as substantially proportional to the lift amount L of the main valve body 63 because the taper angle of the slit taper portion 63g is constant. As in the first embodiment, the equation L = ka (k: constant), or A '= k "L (k": constant).
[0041]
Further, in the third embodiment, the outer peripheral portion (the portion other than the slit tapered portion 63g) of the large-diameter portion 63b of the main valve body 63 is slidably in contact with the inner wall of the main valve chamber 61 to be supported and guided. There is a secondary effect that the stability at the time of vertical movement is high (there is little left and right swing).
Since the configuration of the third embodiment other than the above is the same as that of the first embodiment, the same reference numerals as in FIGS. 1 to 3 showing the first embodiment are assigned to FIGS. Description is omitted.
[0042]
Embodiment 4
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 7 is a longitudinal sectional view showing a motor-operated valve (closed state) of Embodiment 4 according to the present invention, and FIG. 8 is a longitudinal sectional view (A) showing a main part of Embodiment 4 and a front view (B). is there.
The feature of the fourth embodiment is that, instead of the shape of the tapered portion 63c of the first embodiment, a constant depth of a constant depth that becomes wider at a certain depth, for example, at two locations, for example, at a lower portion in the large-diameter portion 63b. Since the slit portion 63h is formed, the same effect as in the case of providing the slit taper portion 63g in the third embodiment can be expected.
[0043]
That is, the flow path cross-sectional area A ′ formed by the gap between the outer peripheral portion (including the constant depth slit portion 63h) of the large-diameter portion 63b of the main valve body 63 and the inner wall of the main valve chamber 61 of the main valve body 60 is The main valve body 63 moves up and down in proportion to a change in the flow path cross-sectional area a formed with the up and down movement of the valve body 23 (A ′ = k′a (k ′: constant). The area A 'can be considered to be substantially proportional to the lift amount L of the main valve body 63 since the angle at which the width of the constant-depth slit portion 63h becomes wide is constant, and as in the first embodiment, the expression L = ka (k : Constant) or A '= k "L (k": constant).
[0044]
In the fourth embodiment, similarly to the third embodiment, the outer peripheral portion of the large-diameter portion 63b of the main valve body 63 is supported and guided by the inner wall of the main valve chamber 61. There is a secondary effect of high stability (small left and right swing).
Since the configuration of the fourth embodiment other than the above is the same as that of the first embodiment, the same reference numerals as those shown in FIGS. 1 to 3 showing the first embodiment are assigned to FIGS. Description is omitted.
[0045]
The present invention can be used as a flow control valve for dry operation by using a pipe between evaporators provided in a refrigeration cycle.
[0046]
【The invention's effect】
As can be understood from the above description, the motor-operated valve of the present invention enables accurate control by making the flow rate of the main valve element directly proportional to the flow rate of the pilot valve. In addition, a small driving unit (stepping motor) can be used to accurately open and close a flow control valve having a large flow rate. In addition, the main valve body is released (moved upward) even when the shock pressure of the refrigerant pressure is high, so that it is possible to cope with a sudden change in the flow rate.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a motor-operated valve (closed state) according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing an intermediate stage of opening and closing of the motor-operated valve according to the first embodiment.
FIG. 3 is a longitudinal sectional view showing the motor-operated valve (open state) of the first embodiment.
FIG. 4 is a longitudinal sectional view showing a motor-operated valve (closed state) according to a second embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing a motor-operated valve (closed state) according to a third embodiment of the present invention.
FIG. 6 is a longitudinal sectional view (A) and a front view (B) showing a main part of the third embodiment.
FIG. 7 is a longitudinal sectional view showing a motor-operated valve (closed state) according to a fourth embodiment of the present invention.
FIG. 8 is a longitudinal sectional view (A) and a front view (B) showing a main part of the fourth embodiment.
FIG. 9 is a longitudinal sectional view of a motor-operated valve according to the related art.
[Explanation of symbols]
1..Electric valve (known example) 2..Valve body 2a..Fluid inflow pipe
2b ... Fluid outflow pipe 2c ... Valve chamber 2d ... Guide bush fixing part
2e ··· Can fixed part 2f ··· Valve seat 3 ··· Valve shaft 3a ··· Valve body
3b ・・ Compression coil spring 3c ・・ Push nut
4 Guide bush 4a Female thread 4b Lower stopper
5 Valve stem holder 5a Male thread 5b Upper stopper
5d Sleeve 6 Can 7 Rotor 7b Spring
8. Stator 8a Stator coil 8b Yoke
8c Lead wire 8d Connector 8e Cover
9 Mounting plate 9a Rotating piece 9b Engagement hole 9c Pressing piece
10. Electric valve (this invention)
20 ・・ Sub valve body 20a ・・ Male thread part 20b ・・ Guide part
21 .. sub-valve chamber 21a .... communication inflow hole 21b .... lower sub-valve chamber
22..Auxiliary valve seat 23..Auxiliary valve body 23a..Auxiliary valve seat contact part
24 Valve stem 25 Fixed screw 26 Guide bush
26a: spiral groove 27: lower stopper (fixed stopper)
27a ・・ Lower stopper piece 30 ・・ Rotor 31 ・・ Moving screw part
32 ··· Shaft holder 32a ·· Equalizing hole
32b spiral groove part 33 push nut 34 compression coil spring
35 ・・ Return spring 36 ・・ Support ring 37 ・・ Upper stopper (movement stopper)
37a Upper stopper piece 40 Can 41 Flange plate
50 stator 50a fitting hole 51 yoke 52 bobbin
53..Stator coil 54..Lead terminal 55..Lead wire
56 Connector 57 Cover 58 Filler
60 main valve body 60a fluid inflow pipe 60b fluid outflow pipe
60c female screw part 60d communication outlet
60e ・・ Inlet hole 60f ・・ Outlet hole 60g ・・ Mounting recess
61 Main valve chamber 61a Upper main valve chamber 61b Lower main valve chamber
61c taper portion (Embodiment 2)
62 .. Valve seat 63 .. Main valve body 63a .. Main valve seat contact part
63b
63c ··· Tapered portion (Embodiment 1) 63d ··· Guided portion 63e ··· Communication hole
63f Step 63g Slit taper (Embodiment 3)
63h: constant depth slit portion (Embodiment 4) 64: coil spring

Claims

The main valve body and the sub-valve body are integrally formed, and the flow rate of the main valve body provided in the main valve body is controlled by moving the sub-valve body toward and away from the sub-valve seat formed in the sub-valve body. A motor-operated valve characterized by:

A main valve element and a sub-valve element for controlling a flow rate of the main valve element, wherein a change in a flow path cross-sectional area of the main valve element is directly proportional to a change in a flow path cross-sectional area of the sub-valve element. And electric valve.

The main valve main body and the sub-valve main body are integrally formed, the main valve main body includes a main valve body for controlling the flow rate of the refrigerant by coming into contact with and separating from a main valve seat in the main valve chamber, and the sub-valve main body is a sub-valve. A sub-valve for controlling the flow rate of the refrigerant by contacting and separating from the sub-valve seat in the room is provided, and the degree of opening of the main valve is increased or decreased by increasing or decreasing the back pressure of the main valve by the sub-valve. The motor-operated valve according to claim 1 or claim 2, wherein

The electric valve according to claim 3, wherein the sub-valve main body includes a stepping motor that operates the sub-valve.

The guided part is formed in the upper part of the main valve body, the guide part is formed in the lower part of the sub-valve body, and the up and down movement of the guided part is guided by the guide part. The motor-operated valve according to claim 4.

A large-diameter portion is formed in the main valve body, and a tapered portion is formed in the large-diameter portion, and a gap between the tapered portion and the main valve chamber inner wall flows from the main valve chamber to the sub-valve chamber. 4. The motor-operated valve according to claim 3, wherein an area of the flow passage is increased by upward movement of the main valve body. 5.

A large diameter portion is formed in the main valve body, and a tapered portion is formed in the main valve chamber inner wall portion corresponding to the large diameter portion, and a gap between the tapered portion and an outer peripheral surface of the large diameter portion of the main valve body is formed. 4. The electric motor according to claim 3, wherein a flow path is formed from the main valve chamber to the sub-valve chamber, and the area of the flow path is increased by the upward movement of the main valve body. valve.

A large diameter portion is formed in the main valve body, and a slit taper portion having a substantially constant width is formed in the large diameter portion, and a gap between the slit taper portion and the main valve chamber inner wall is formed from the main valve chamber to the sub valve. The motor-operated valve according to claim 3, wherein the motor-operated valve is formed as a flow path to a valve chamber, and is configured such that an area of the flow path increases by upward movement of the main valve body.

A large diameter portion is formed in the main valve body, a constant depth slit portion having a constant depth is formed in the large diameter portion, and a gap between the constant depth slit portion and the main valve chamber inner wall is formed by the main valve. 4. The motor-operated valve according to claim 3, wherein the valve is formed as a flow path from the chamber to the auxiliary valve chamber, and the area of the flow path is increased by the upward movement of the main valve body. 5.

The motor-operated valve according to any one of claims 1 to 9, wherein a flow rate of the main valve body is changed similarly to a flow rate of the sub-valve body.