JP3905602B2

JP3905602B2 - Motorized valve

Info

Publication number: JP3905602B2
Application number: JP17871397A
Authority: JP
Inventors: 敦希井上; 共存大内
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 1997-07-03
Filing date: 1997-07-03
Publication date: 2007-04-18
Anticipated expiration: 2017-07-03
Also published as: JPH1122846A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えばヒートポンプ式エアコンや冷凍機等を構成する冷凍サイクルに組み込まれて使用される電動弁に係り、特に、ステッピングモータのキャン部分と該キャンを弁本体に連結する蓋状部材とを改善した電動弁に関する。
【０００２】
【従来の技術】
従来のこの種の電動弁としては、図４に示されるものが提案されている。図示例の電動弁１' は、基本的には、ステッピングモータ１０と、弁本体２０と、ロータ軸３５及び弁軸３０とを具備しており、前記ロータ軸３５を前記ステッピングモータ１０により回転駆動してねじ送りにより昇降させ、それに伴って昇降する弁軸３０の弁体３１で前記弁本体２０に形成された流体入出口（弁座）２３を開閉する（開口面積を変化させる）ことにより流量を調整するようになっている。
【０００３】
前記ステッピングモータ１０は、前記弁本体２０に蓋状部材１８を介して連結固定された円筒状のキャン１１の外周部に嵌装されたステータヨーク１３と、ボビン１４と、このボビン１４に巻装され、外部から通電されるマグネットワイヤ１５と、スリーブ４０に固定されたボンド磁石よりなるロータ３９と、を備えて構成されている。
【０００４】
前記弁本体２０は、弁室２１を有し、この弁室２１に連通する導管２４が接続される流体入出口２２が設けられ、その底面部に導管２５が接続されるとともに、前記弁軸３０により開閉される前記流体入出口２３が形成されている。前記弁本体２０の弁室２１上方には、内周部に雌ねじ部が形成されたガイドブッシュ２６が内嵌固定されている。
【０００５】
前記キャン１１、前記蓋状部材１８、及び、前記弁本体２０との組立密封固定は、まず、前記弁本体２０の上部環状突出片２０ａに前記蓋状部材１８を嵌合し、前記上部環状突出片２０ａを外周方向にかしめると共に、前記弁本体２０の外周上部２０ｂと前記蓋状部材１８の下面とをロー付け溶接Ａを行う。その後、前記キャン１１と前記蓋状部材１８内に前記ガイドブッシュ２６、ロータ３９、スリーブ４０、弁軸３０、ロータ軸３５等を収納した後、前記蓋状部材１８の上部鍔部１８ａと前記キャン１１の下部鍔部１１ａとを当接させて、その周囲をＴｉＧ溶接（タングステンイナートガス溶接）等で拝み溶接Ｂを行い、これによって、前記キャン１１内を密封状態としている。
【０００６】
このような構成の電動弁１’においては、前記マグネットワイヤ１５を一方向に通電励磁すると、ロータ３９、スリーブ４０、ロータ軸３５、ホルダ２８等が一体的に回転し、前記雌ねじ部と雄ねじ部との螺合によるねじ送りにより前記弁軸３０が下降せしめられて前記流体入出口２３を閉方向に調整する。また、前記マグネットワイヤ１５を他方向に通電励磁すると、前記弁軸３０が上昇して前記流体入出口２３を開方向に調整する。
【０００７】
【発明が解決しようとする課題】
そして、前記電動弁１’は、冷凍サイクルに組み込まれて使用される稼働時には、前記キャン１１内にも冷媒が供給されるので、該キャン１１内は前記冷媒によって圧力状態に置かれている。このため、前記キャン１１と前記蓋状部材１８とのＴｉＧ溶接等の拝み溶接部Ｂ、及び、前記弁本体２０の外周部２０ｂと前記蓋状部材１８の下面とのロー付け溶接部Ａは、その電動弁１’の前記冷媒の圧力負荷状態での長期の使用に耐えるものでなければならない。
【０００８】
また、近年、フロンガス等によるオゾン層の破壊等の環境上の問題から旧来から使用されている冷媒Ｒ−２２が、フロン規制の対象となったことからその代替冷媒として例えば冷媒Ｒ４１０Ａが採用されてきている。この代替冷媒Ｒ４１０Ａは、前記冷凍サイクル等で使用する場合には、前記旧来からの冷媒Ｒ−２２に比べて、高圧状態（概ね１．４〜１．５倍程度）で作動することになる。このため、前記電動弁１’の稼働中は、前記キャン１１内も代替冷媒Ｒ４１０Ａの使用によって、従来の冷媒Ｒ−２２に比べて高圧状態となり、前記旧来からの冷媒Ｒ−２２ではその強度に問題がなかった前記溶接部Ｂ及びロー付け溶接部Ａにおいても、前記高圧状態に耐える構造のものでなければならなくなった。
【０００９】
ところで、本発明者等の実験によれば、従来の電動弁１’の前記キャン１１と前記蓋状部材１８とのＴｉＧ溶接等の拝み接合溶接部Ｂは、図５に示したように、前記新冷媒Ｒ４１０Ａの内圧によって、前記キャン１１と前記蓋状部材１８との各々は、反対方向の作用力Ｆもしくは作用力Ｆ’を受けることとなり、前記蓋状部材１８の上部鍔部１８ａと前記キャン１１の下部鍔部１１ａとを前記拝み接合溶接部Ｂ部分の作用点Ｅを中心として互いに離す方向に作用し、前記拝み接合溶接部Ｂに分離作用を生じさせることとなる。
【００１０】
前記キャン１１内の冷媒は、その稼働中、その圧力を交番して変化するものであるので、前記作用力Ｆ及び作用力Ｆ’がその強さを繰り返して交番的に変化することとなる。このことは、前記拝み接合溶接部Ｂの作用点Ｅに繰り返し応力が作用することを意味し、やがて、該繰り返し応力によって前記拝み接合溶接部Ｂの溶接ビート（作用点Ｅ）が疲労して該溶接ビート内に亀裂Ｇが発生する問題が生ずるおそれがある。更に、該亀裂Ｇは、前記繰り返し応力の作用によって成長して、前記電動弁１’の動作に不具合が生じるおそれがある。
【００１１】
本発明は、前記のような問題に鑑みてなされたもので、その目的とするところは、従来の電動弁に大きな改造を施さずに、冷媒の内部圧力に基づくキャン、蓋状部材、及び、前記弁本体の接合密封部分の亀裂あるいはその成長を防止する電動弁を提供することにある。
【００１２】
【課題を解決するための手段】
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、有底筒状のキャンと、該キャンの開口部に溶接結合され前記キャンよりも厚い平板状の蓋状部材と、該蓋状部材に取り付け固定される弁本体と、を備えた電動弁であって、前記蓋状部材は、前記キャンの開口部と対向する側の外周部に前記キャンの開口部側の端部が係合する第１の段差形状部を有し、前記キャンの開口部と反対の側の外周部に第２の段差形状部を有し、前記蓋状部材の前記外周部の厚みを前記蓋状部分の他の部分の厚みよりも薄くしたことを特徴としている。
【００１３】
また、本発明の電動弁の好ましい具体的な態様は、前記キャンと前記蓋状部材との溶接部分における前記蓋状部材の厚み方向の中心が、前記キャンの開口部側の端面と前記第１の段差形状部との接合部に位置するようにしたことを特徴としている。
【００１４】
このような構成とされた本発明に係る電動弁においては、キャンと、このキャンよりも厚い平板状の蓋状部材との接合溶接部を、該蓋状部材の外周に形成した上部段差形状部（第１の段差形状部）に前記キャンの開口部の端部を係合する構造として、その周囲を溶接するべく構成したので、従来の冷媒に比べて高圧の代替冷媒Ｒ４１０Ａが前記キャン内に供給されても、前記キャンは、前記代替冷媒Ｒ４１０Ａの径方向の圧力に対しては、筒状の開口部で受けることとなり、かつ、前記キャンの長手方向（上方）の前記冷媒Ｒ４１０Ａの圧力に対しては、前記溶接部の引っ張り力として受けるので、該接合部が、キャン内の従来の冷媒に比べて高い圧力の冷媒Ｒ４１０Ａによって、その稼働中、繰り返し応力の作用を受けたとしても、該繰り返し応力によって亀裂が発生するようなことはない。
また、前記蓋状部材の周部の下部に段差形状部（第２の段差形状部）を形成したことにより、溶接位置のバラツキをなくして、溶接強度の強い溶接部を得ることができる。
【００１５】
【発明の実施の形態】
以下、本発明の電動弁の一実施形態を添付図面を参照しながら詳細に説明する。該実施形態を説明するに当たって、前記従来例と同一機能を奏するものは同じ符号を付して説明する。
【００１６】
図１は、本実施形態の電動弁１の縦断面図である。該図１に示す電動弁１は、基本的には、ステッピングモータ１０と、弁本体２０と、ロータ軸３５及び弁軸３０とを具備しており、前記ロータ軸３５を前記ステッピングモータ１０により回転駆動してねじ送りにより昇降させ、それに伴って昇降する弁軸３０で前記弁本体２０に形成された流体入出口（弁座）２３を弁体３１で開閉する（開口面積を変化させる）ことにより流量を調整するようになっている。
【００１７】
前記ステッピングモータ１０は、前記弁本体２０に蓋状部材３３を介して連結固定された円筒状のキャン３２の外周部に嵌装されたステータヨーク１３と、ボビン１４と、該ボビン１４に巻装され、外部から通電されるマグネットワイヤ１５と、前記ステータヨーク１３、ボビン１４及びマグネットワイヤ１５の外周を封止するモールド１２と、前記キャン３２の内部に配置され、後述するスリーブ４０に固定されたボンド磁石よりなるロータ３９と、を備えて構成されている。
【００１８】
前記モールド１２、ステータヨーク１３、ボビン１４、及びマグネットワイヤ１５は、キャン３２の外周に一体的に嵌装され、それらはモールド１２にビス１６で取り付けられた押圧係止具１７の係止凸部１７ａを前記キャン３２の外周に、例えば９０度間隔で４箇所設けられた凹部１９のいずれかに嵌合させることにより位置決め及び抜止めを行うようになっている。
【００１９】
前記弁本体２０は、弁室２１を有し、該弁室２１に連通する導管２４が接続される流体入出口２２が設けられ、その底面部に導管２５が接続されるとともに、前記弁軸３０の弁体３１により開閉される流体入出口（弁座）２３が形成されている。前記弁本体２０の弁室２１の上方には、内周部に雌ねじ部２７が形成されたガイドブッシュ２６が、内嵌固定されている。
【００２０】
前記ガイドブッシュ２６の雌ねじ部２７には、ホルダ２８の外周に形成された雄ねじ部２９が螺合せしめられ、該ホルダ２８の内周下部にフランジ付きの弁軸３０が摺動可能に嵌挿され、また、前記ホルダ２８の下部には、前記弁軸３０のフランジ３０ａを受けるカラー３４が圧入固定されていて、前記弁軸３０は、前記ホルダ２８内に縮装されたコイルスプリング３７により常時下方に付勢されている。前記ホルダ２８の上部には、ロータ軸３５がそれと一体的に回転移動できるように内嵌固定されており、前記ホルダ２８の上部外周には、凸状の可動側ストッパ４５が、下向きに突設された合成樹脂製のスリーブ４０と一体的に回転移動できるように成形固定されている。
【００２１】
また、前記ロータ軸３５の上部には、コイルスプリング３６が装填されている。このコイルスプリング３６は、ロータ３９が回転（逆転）せしめられてロータ軸３５やスリーブ４０等が前記雌ねじ部２７と雄ねじ部２９との螺合によるねじ送りにより上昇せしめられて、前記ねじ部２７，２９の螺合が外れたとき、前記ホルダ２８をガイドブッシュ２６側に押圧して再螺合し易くするためのものである。
【００２２】
前記ガイドブッシュ２６の上部外周には、前記可動側ストッパ４５が衝接せしめられる凸状の固定側ストッパ５５が上向きに突設された合成樹脂製の固定受け座５０が成形固定されている。
【００２３】
前記キャン３２は、一端に開口部３２ａを備えた有底筒状形状をしており、底部３２ｂが楕円球面状に形成されると共に、前記開口部３２ａが拡大径とされ、一体絞り加工で成形されている。また、前記蓋状部材３３は、図２（ａ）に示すように、キャン３２よりも厚い環状平板状の蓋状部材として形成され、内部に前記弁本体２０の上部環状突出片２０ａに嵌合する内部孔３３ａを有すると共に、その外周部に上部の段差形状部（第１の段差形状部）３３ｂと下部の段差形状部（第２の段差形状部）３３ｃとを有している。
【００２４】
前記キャン３２、前記環状平板の蓋状部材３３、及び、前記弁本体２０との組立密封固定は、まず、図２（ｂ）に示すように、前記弁本体２０の上部環状突出片２０ａに前記蓋状部材３３の内部孔３３ａを嵌合し、前記上部環状突出片２０ａを外周方向にかしめると共に、前記弁本体２０の外周部２０ｂと前記蓋状部材３３の下面とをロー付け溶接Ｃを行う。その後、前記キャン３２と前記蓋状部材３３内に前記ガイドブッシュ２６、ロータ３９、スリーブ４０、弁軸３０、ロータ軸３５等を収納した後、前記蓋状部材３３の上部の段差形状部３３ｂに前記キャン３２の前記開口部３２ａの端部を係合させ、その周囲をＴｉＧ溶接（タングステンイナートガス溶接）等で溶接Ｄを行い、これによって、前記キャン３２内を密封状態としている。
【００２５】
前記溶接Ｄにおいて、図３（ａ）、（ｂ）に示す比較例のように、該溶接部Ｄの前記キャン３２の板厚ｔに対して、前記蓋状部材３３の板厚Ｔが厚い場合には、該蓋状部材３３のヒートマスが増加してしまい、ＴｉＧ溶接時に、該溶接Ｄの溶け込みの位置にバラツキが生じ易く、その結果として、前記キャン３２もしくは蓋状部材３３の溶接部分Ｄ₁、Ｄ₂は、その接合部からの長さｌ₁もしくはｌ₂のいずれか一方が短くなりアンバランスとなってしまい、接合強度が低いものとなる虞がある。
【００２６】
このため、本実施形態においては、この溶接Ｄの溶け込み位置のバラツキを防ぐために、前記蓋状部材３３の下部に下部の段差形状部３３ｃを形成して、該蓋状部材３３の外周部の肉厚Ｔ₁を薄くすることで、前記蓋状部材３３のヒートマスを減少させて、ＴｉＧ溶接時の該溶接Ｄの溶け込みの位置のバラツキを少なくし、前記キャン３２と蓋状部材３３の溶接部分Ｄの接合部からの長さｌ₁、ｌ₂を同じ長さに一致させたものである。これにより、前記キャン３２と蓋状部材３３の溶接部分Ｄを強固な接合部としたものである。すなわち、溶接Ｄの接合部からの長さｌ₁、ｌ₂を同じ長さに一致させることで、キャン３２と蓋状部材３３との溶接部分における蓋状部材の厚み方向の中心が、キャン３２の開口部側の端面と上部の段差形状部３３ｂとの接合部に位置するようにしている。
【００２７】
このような構成の本実施形態の電動弁１においては、前記マグネットワイヤ１５を一方向に通電励磁すると、ロータ３９、スリーブ４０、ロータ軸３５、ホルダ２８等が一体的に正転（ここでは右回りに回転）し、前記雌ねじ部２７と雄ねじ部２９との螺合によるねじ送りにより前記弁軸３０が下降せしめられて、前記弁体３１により、前記流体入出口２３が閉じられる。
【００２８】
前記流体入出口２３が弁体３１で閉じられた時点では、前記可動側ストッパ４５が固定側ストッパ５５に未だ衝接しておらず、前記弁軸３０の弁体３１が前記流体入出口２３を閉じたまま、前記ホルダ２８等はさらに回転下降せしめられる。このときの前記弁軸３０に対する前記ホルダ２８の下降量は、前記コイルスプリング３７が圧縮されることにより吸収される。
【００２９】
その後さらに、前記ホルダ２８等が回転下降せしめられると、前記可動側ストッパ４５が固定側ストッパ５５に衝接し、これにより、前記ロータ３９への通電励磁が続行されていても、前記スリーブ４０、軸３５、ホルダ２８等の回転下降運動が強制的に停止せしめられる。
【００３０】
また、流体入出口２３を開くときは、マグネットワイヤ１５を前記流体入出口２３を閉じるときとは逆方向に通電励磁することにより、ロータ軸３５を逆回転させて、前記流体入出口２３を開口する。
【００３１】
このように、本実施形態の電動弁１は、キャン３２と、該キャン３２を弁本体２０に連結固定する蓋状部材３３とを、前記説明した構造とし、前記キャン３２と前記蓋状部材３３との接合溶接部を、該蓋状部材３３の外周に形成した上部の段差形状部３３ｂに前記キャン３２の開口部３２ａの端部を係合する構造として、その周囲を溶接するべく構成したので、従来の冷媒に対して高圧の代替冷媒が前記キャン３２内に供給されても、前記キャン３２は、前記代替冷媒の径方向の圧力に対しては、筒状の開口部３２ａで受けることとなり、かつ、前記代替冷媒の長手方向（上方）の圧力に対しては、前記溶接部Ｄの引っ張り力として受けるので、該接合部Ｄが、キャン３２内の従来の冷媒に比べて高い圧力の代替冷媒によって、その稼働中、繰り返し応力の作用を受けたとしても、該繰り返し応力によって亀裂が発生するようなことはない。
【００３２】
また、前記蓋状部材３３は、代替冷媒の作動圧力に耐えるために、その周部の下部に段差形状部３３ｃを形成したことにより、前記溶接位置のバラツキをなくして、溶接強度の強い溶接部を得ることができる。
【００３３】
【発明の効果】
以上の説明から理解されるように、本発明の電動弁は、蓋状部材を環状平板とし、該環状平板の外周部に前記キャンの筒状開口部を係合して該係合部を溶接接合したことで、新冷媒に対応した強度の強いキャン部分を実現できる。
また、蓋状部材の環状平板部材の下部外周に段差形状部を設けたことで、溶接位置を一定とすることができるので、強度のある接合部を実現できる。
【図面の簡単な説明】
【図１】本発明に係る電動弁の一実施形態の断面図。
【図２】図１に示される電動弁のキャンと蓋状部材との拡大断面図。
【図３】電動弁のキャンと蓋状部材との接合溶接部の比較例を示す断面図。
【図４】従来の電動弁の一例を示す断面図。
【図５】図４の従来の電動弁におけるキャンと蓋状部材との溶接接合部を示す拡大断面図。
【符号の説明】
１電動弁
１０ステッピングモータ
２０弁本体
２０ａ上部環状突出部
２３流体入出口
３０弁軸
３２キャン
３２ａ開口部
３３蓋状部材
３３ａ内部孔
３３ｂ上部環状段差形状部
３３ｃ下部環状段差形状部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric valve used by being incorporated in a refrigeration cycle constituting, for example, a heat pump air conditioner or a refrigerator, and in particular, includes a can portion of a stepping motor and a lid-like member that connects the can to a valve body. It relates to an improved electric valve.
[0002]
[Prior art]
As a conventional electric valve of this kind, one shown in FIG. 4 has been proposed. The motor-operated valve 1 ′ in the illustrated example basically includes a stepping motor 10, a valve body 20, a rotor shaft 35 and a valve shaft 30, and the rotor shaft 35 is rotationally driven by the stepping motor 10. The valve body 31 of the valve shaft 30 is lifted and lowered by screw feed, and the fluid inlet / outlet (valve seat) 23 formed in the valve body 20 is opened and closed (the opening area is changed). To be adjusted.
[0003]
The stepping motor 10 includes a stator yoke 13 fitted to an outer peripheral portion of a cylindrical can 11 connected and fixed to the valve body 20 via a lid-like member 18, a bobbin 14, and a winding around the bobbin 14. The magnet wire 15 energized from the outside and the rotor 39 made of a bonded magnet fixed to the sleeve 40 are provided.
[0004]
The valve body 20 includes a valve chamber 21, a fluid inlet / outlet port 22 to which a conduit 24 communicating with the valve chamber 21 is connected, a conduit 25 is connected to a bottom surface portion thereof, and the valve shaft 30 is provided. The fluid inlet / outlet port 23 is opened / closed by. Above the valve chamber 21 of the valve main body 20, a guide bush 26 having an internal thread portion formed on the inner peripheral portion is fitted and fixed.
[0005]
To assemble and fix the can 11, the lid-like member 18, and the valve body 20, first, the lid-like member 18 is fitted to the upper annular projection piece 20 a of the valve body 20, and the upper annular projection The piece 20a is caulked in the outer circumferential direction, and the outer circumferential upper portion 20b of the valve body 20 and the lower surface of the lid-like member 18 are brazed and welded A. Thereafter, after the guide bush 26, the rotor 39, the sleeve 40, the valve shaft 30, the rotor shaft 35, etc. are accommodated in the can 11 and the lid member 18, the upper flange portion 18a of the lid member 18 and the can 11 is brought into contact with the lower flange portion 11a, and the periphery thereof is subjected to welding B by TiG welding (tungsten inert gas welding) or the like, whereby the inside of the can 11 is sealed.
[0006]
In the motor-operated valve 1 ′ having such a configuration, when the magnet wire 15 is energized and excited in one direction, the rotor 39, the sleeve 40, the rotor shaft 35, the holder 28, and the like rotate integrally, and the female screw portion and the male screw portion. The valve shaft 30 is lowered by screw feed by screwing to adjust the fluid inlet / outlet 23 in the closing direction. Further, when the magnet wire 15 is energized and excited in the other direction, the valve shaft 30 is raised to adjust the fluid inlet / outlet 23 in the opening direction.
[0007]
[Problems to be solved by the invention]
When the motor-operated valve 1 ′ is used by being incorporated in a refrigeration cycle, refrigerant is also supplied into the can 11, so that the inside of the can 11 is placed in pressure by the refrigerant. For this reason, worship welded portions B such as TiG welding between the can 11 and the lid-like member 18, and a brazed weld portion A between the outer peripheral portion 20b of the valve body 20 and the lower surface of the lid-like member 18, The motor-operated valve 1 ′ must be able to withstand long-term use of the refrigerant under a pressure load.
[0008]
Further, in recent years, refrigerant R-22, which has been used for a long time because of environmental problems such as destruction of the ozone layer by chlorofluorocarbon gas, has been subject to chlorofluorocarbon regulations. For example, refrigerant R410A has been adopted as an alternative refrigerant. ing. When used in the refrigeration cycle or the like, the alternative refrigerant R410A operates in a higher pressure state (approximately 1.4 to 1.5 times) than the conventional refrigerant R-22. For this reason, during operation of the motor-operated valve 1 ′, the can 11 also has a higher pressure than the conventional refrigerant R-22 due to the use of the alternative refrigerant R410A, and the conventional refrigerant R-22 has a higher strength. The welded part B and the brazed welded part A, which had no problem, must have a structure that can withstand the high-pressure state.
[0009]
By the way, according to the experiments by the present inventors, as shown in FIG. 5, the welding joint B such as TiG welding between the can 11 and the lid-like member 18 of the conventional motor-operated valve 1 ′ is Due to the internal pressure of the new refrigerant R410A, each of the can 11 and the lid member 18 receives an acting force F or an acting force F ′ in the opposite direction, and the upper flange portion 18a of the lid member 18 and the can member 18 11 and the lower flange portion 11a in the direction of separating from each other around the point of action E of the welding joint welded portion B, thereby causing the separating joint welded portion B to have a separating action.
[0010]
Since the refrigerant in the can 11 changes its pressure during operation, the acting force F and the acting force F ′ change alternately by repeating the strength. This means that repeated stress acts on the point of application E of the weld joint weld B, and eventually the weld beat (work point E) of the joint weld B becomes fatigued due to the repeated stress. There is a risk that a crack G will occur in the welding beat. Further, the crack G grows due to the action of the repeated stress, and there is a possibility that a malfunction occurs in the operation of the motor-operated valve 1 ′.
[0011]
The present invention has been made in view of the problems as described above, and the object of the present invention is to provide a can based on the internal pressure of the refrigerant, a lid-shaped member, and An object of the present invention is to provide a motor-operated valve that prevents cracking or growth of a joint sealing portion of the valve body.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the motor-operated valve according to the present invention basically includes a bottomed cylindrical can and a flat lid-like member welded to the opening of the can and thicker than the can. A valve main body attached to and fixed to the lid-like member, wherein the lid-like member has an end on the opening side of the can on an outer peripheral portion facing the opening of the can. part has a first step-shaped portion that engages, has a second step-shaped portion on the outer peripheral portion of the opposite side of the opening of the can, the thickness of the outer peripheral portion of the lid-like member It is characterized by being thinner than the thickness of the other part of the lid-like part .
[0013]
Moreover, the preferable specific aspect of the motor operated valve of the present invention is such that the center in the thickness direction of the lid-like member at the welded portion between the can and the lid-like member is the end surface on the opening side of the can and the first. It is characterized in that it is located at the joint with the step-shaped portion .
[0014]
In the electric valve according to such a configuration as has been present invention, the can and the bonding weld a thick plate-shaped lid member than the scan, the upper step shape portion formed on the outer periphery of the cap-like member Since the periphery of the can is engaged with the end of the opening of the can (first step-shaped portion) , the periphery of the can is welded. Therefore, the alternative refrigerant R410A having a higher pressure than the conventional refrigerant is contained in the can. Even if supplied, the can receives the pressure in the radial direction of the alternative refrigerant R410A at the cylindrical opening, and the pressure of the refrigerant R410A in the longitudinal direction (upward) of the can On the other hand, since it receives as a tensile force of the welded portion, even if the joint portion is subjected to repeated stress during operation by the refrigerant R410A having a higher pressure than the conventional refrigerant in the can, Repetitive Is not it, such as cracks caused by the stress.
Moreover, by forming the step-shaped portion (second step-shaped portion) at the lower part of the peripheral portion of the lid-like member, it is possible to obtain a welded portion with high welding strength by eliminating variations in the welding position.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an electric valve according to the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiment, components having the same functions as those of the conventional example will be described with the same reference numerals.
[0016]
FIG. 1 is a longitudinal sectional view of a motor-operated valve 1 according to this embodiment. The motor-operated valve 1 shown in FIG. 1 basically includes a stepping motor 10, a valve body 20, a rotor shaft 35 and a valve shaft 30, and the rotor shaft 35 is rotated by the stepping motor 10. By opening and closing the fluid inlet / outlet (valve seat) 23 formed in the valve main body 20 with the valve shaft 30 by the valve shaft 30 that is driven and lifted by screw feed, and is lifted and lowered accordingly (opening area is changed). The flow rate is adjusted.
[0017]
The stepping motor 10 includes a stator yoke 13 fitted to the outer periphery of a cylindrical can 32 that is connected and fixed to the valve body 20 via a lid-like member 33, a bobbin 14, and a bobbin 14 that is wound around the bobbin 14. The magnet wire 15 energized from the outside, the mold 12 that seals the outer periphery of the stator yoke 13, the bobbin 14, and the magnet wire 15, and the can 32 are disposed inside and fixed to a sleeve 40, which will be described later. And a rotor 39 made of a bonded magnet.
[0018]
The mold 12, the stator yoke 13, the bobbin 14 , and the magnet wire 15 are integrally fitted on the outer periphery of the can 32, and these are the locking projections of the press locking tool 17 attached to the mold 12 with screws 16. Positioning and retaining are carried out by fitting 17a on the outer periphery of the can 32, for example, in any one of four recesses 19 provided at intervals of 90 degrees.
[0019]
The valve body 20 includes a valve chamber 21, a fluid inlet / outlet port 22 to which a conduit 24 communicating with the valve chamber 21 is connected, a conduit 25 is connected to a bottom surface portion thereof, and the valve shaft 30 is provided. A fluid inlet / outlet (valve seat) 23 that is opened and closed by the valve body 31 is formed. Above the valve chamber 21 of the valve body 20, a guide bush 26 having an internal thread portion 27 formed on the inner peripheral portion is fitted and fixed.
[0020]
A male screw portion 29 formed on the outer periphery of the holder 28 is screwed into the female screw portion 27 of the guide bush 26, and a valve shaft 30 with a flange is slidably fitted into the inner peripheral lower portion of the holder 28. A collar 34 that receives the flange 30a of the valve shaft 30 is press-fitted and fixed to the lower portion of the holder 28. The valve shaft 30 is always lowered by a coil spring 37 that is retracted in the holder 28. Is being energized. A rotor shaft 35 is fitted and fixed to the upper portion of the holder 28 so that the rotor shaft 35 can rotate and move integrally therewith. A convex movable side stopper 45 projects downward on the outer periphery of the upper portion of the holder 28. The synthetic resin sleeve 40 is molded and fixed so as to be integrally rotatable.
[0021]
A coil spring 36 is loaded on the upper portion of the rotor shaft 35. In the coil spring 36, the rotor 39 is rotated (reversely rotated), and the rotor shaft 35, the sleeve 40, and the like are raised by screw feeding of the female screw portion 27 and the male screw portion 29, and the screw portions 27, When 29 is disengaged, the holder 28 is pressed toward the guide bush 26 to facilitate re-engagement.
[0022]
On the outer periphery of the upper portion of the guide bush 26, a synthetic resin fixed receiving seat 50 is formed and fixed. The fixed fixed stopper 55 is provided with a convex fixed side stopper 55 on which the movable side stopper 45 comes into contact.
[0023]
The can 32 has a bottomed cylindrical shape with an opening 32a at one end, the bottom 32b is formed in an elliptical spherical shape, and the opening 32a has an enlarged diameter, and is formed by integral drawing. Has been. Further, as shown in FIG. 2A, the lid-like member 33 is formed as an annular flat - plate- like lid-like member thicker than the can 32, and is fitted into the upper annular projecting piece 20a of the valve body 20 inside. And has an upper step shape portion (first step shape portion) 33b and a lower step shape portion (second step shape portion) 33c on the outer periphery thereof.
[0024]
As shown in FIG. 2B, first, the can 32, the annular flat plate lid member 33, and the valve body 20 are assembled and fixed to the upper annular projecting piece 20a of the valve body 20, as shown in FIG. The inner hole 33a of the lid-like member 33 is fitted, the upper annular protruding piece 20a is caulked in the outer circumferential direction, and the outer peripheral portion 20b of the valve body 20 and the lower surface of the lid-like member 33 are brazed and welded C. Do. Thereafter, after the guide bush 26, the rotor 39, the sleeve 40, the valve shaft 30, the rotor shaft 35, etc. are accommodated in the can 32 and the lid-like member 33, the step-shaped portion 33b above the lid-like member 33 is placed. The end portion of the opening 32a of the can 32 is engaged, and the periphery thereof is welded by TiG welding (tungsten inert gas welding) or the like, whereby the inside of the can 32 is sealed.
[0025]
In the weld D, when the plate thickness T of the lid-like member 33 is thicker than the plate thickness t of the can 32 of the weld D as in the comparative example shown in FIGS. , the cause to increase the heat mass of the lid-like member 33, at the time TiG welding, likely to occur variation in the position of penetration of the weld D, as a result, the welding portion D ₁ of the the can 32 or the cap-like member 33 , D ₂ has a possibility that either _one of the lengths l ₁ or l ₂ from the joint portion becomes short and becomes unbalanced, resulting in low joint strength.
[0026]
For this reason, in this embodiment, in order to prevent variation in the welding position of the weld D, a lower step-shaped portion 33c is formed in the lower portion of the lid-like member 33, and the meat of the outer peripheral portion of the lid-like member 33 is formed. By reducing the thickness T ₁ , the heat mass of the lid-like member 33 is reduced, so that the variation in the welding position of the weld D during TiG welding is reduced, and the welded portion D of the can 32 and the lid-like member 33 is reduced. The lengths l ₁ and l ₂ from the joints are made to coincide with each other. Thereby, the welding part D of the said can 32 and the lid-shaped member 33 is made into the strong junction part. That is, by making the lengths l ₁ and l ₂ from the joint portion of the weld D coincide with each other, the center in the thickness direction of the lid-like member at the welded portion between the can 32 and the lid-like member 33 is the can 32. It is made to be located in the junction part of the end surface of this opening part side, and the upper level | step difference shape part 33b.
[0027]
In the motor-operated valve 1 according to the present embodiment having such a configuration, when the magnet wire 15 is energized and excited in one direction, the rotor 39, the sleeve 40, the rotor shaft 35, the holder 28, and the like are integrally rotated forward (here, the right side). The valve shaft 30 is lowered by screw feed by screwing of the female screw portion 27 and the male screw portion 29, and the fluid inlet / outlet port 23 is closed by the valve body 31.
[0028]
When the fluid inlet / outlet 23 is closed by the valve body 31, the movable side stopper 45 is not yet in contact with the fixed side stopper 55, and the valve body 31 of the valve shaft 30 closes the fluid inlet / outlet 23. The holder 28 and the like are further rotated and lowered. The descending amount of the holder 28 with respect to the valve shaft 30 at this time is absorbed by the compression of the coil spring 37.
[0029]
Thereafter, when the holder 28 and the like are further rotated and lowered, the movable side stopper 45 comes into contact with the fixed side stopper 55, so that even if energization excitation to the rotor 39 is continued, the sleeve 40, shaft 35, the rotary lowering movement of the holder 28 and the like is forcibly stopped.
[0030]
When the fluid inlet / outlet 23 is opened, the magnet wire 15 is energized and excited in the opposite direction to that when the fluid inlet / outlet 23 is closed, thereby rotating the rotor shaft 35 in the reverse direction to open the fluid inlet / outlet 23. To do.
[0031]
As described above, the motor-operated valve 1 according to this embodiment includes the can 32 and the lid-like member 33 that connects and fixes the can 32 to the valve body 20 as described above, and the can 32 and the lid-like member 33. The joint welded portion is configured to engage the end portion of the opening 32a of the can 32 with the upper stepped shape portion 33b formed on the outer periphery of the lid-like member 33 so as to weld the periphery thereof. Even if a high-pressure alternative refrigerant is supplied into the can 32 relative to the conventional refrigerant, the can 32 receives the pressure in the radial direction of the alternative refrigerant at the cylindrical opening 32a. In addition, since the pressure in the longitudinal direction (upward) of the alternative refrigerant is received as a tensile force of the weld D, the junction D is an alternative to a higher pressure than the conventional refrigerant in the can 32. Depending on the refrigerant, Ri returns even under the action of stress, is not it, such as cracks caused by the repeated stress.
[0032]
Further, the lid-like member 33 is formed with a step-shaped portion 33c at the lower portion of the peripheral portion thereof to withstand the operating pressure of the alternative refrigerant, thereby eliminating variations in the welding position and having a high welding strength. Can be obtained.
[0033]
【The invention's effect】
As can be understood from the above description, the motor-operated valve of the present invention has a lid-like member as an annular flat plate, engages the cylindrical opening of the can with the outer peripheral portion of the annular flat plate, and welds the engaging portion. By joining, a strong can part corresponding to the new refrigerant can be realized.
Further, since the stepped portion is provided on the outer periphery of the lower part of the annular flat plate member of the lid-like member, the welding position can be made constant, so that a strong joint can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of a motor-operated valve according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a can and a lid-like member of the motor-operated valve shown in FIG.
FIG. 3 is a cross-sectional view showing a comparative example of a welded joint between a motor-operated valve can and a lid-like member.
FIG. 4 is a cross-sectional view showing an example of a conventional motor-operated valve.
5 is an enlarged cross-sectional view showing a welded joint between a can and a lid-like member in the conventional motor-operated valve shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motorized valve 10 Stepping motor 20 Valve main body 20a Upper annular protrusion 23 Fluid inlet / outlet 30 Valve shaft 32 Can 32a Opening 33 Cover member 33a Inner hole 33b Upper annular step shape part 33c Lower annular step shape part

Claims

有底筒状のキャンと、該キャンの開口部に溶接結合され前記キャンよりも厚い平板状の蓋状部材と、該蓋状部材に取り付け固定される弁本体と、を備えた電動弁であって、
前記蓋状部材は、前記キャンの開口部と対向する側の外周部に前記キャンの開口部側の端部が係合する第１の段差形状部を有し、前記キャンの開口部と反対の側の外周部に第２の段差形状部を有し、
前記蓋状部材の前記外周部の厚みを前記蓋状部材の他の部分の厚みよりも薄くしたことを特徴とする電動弁。An electric valve comprising a bottomed cylindrical can, a flat lid-like member welded to the opening of the can and thicker than the can, and a valve body attached and fixed to the lid-like member. And
The lid-like member, the end of the opening side of the can on the outer periphery of the side facing the opening of the can has a first step-shaped portion which engages, opposite the opening of the can A second step-shaped portion on the outer peripheral portion on the side,
The motor-operated valve characterized in that the thickness of the outer peripheral portion of the lid-like member is made thinner than the thickness of the other part of the lid-like member .

前記キャンと前記蓋状部材との溶接部分は、前記蓋状部材の厚み方向の中心が、前記キャンの開口部側の端面と前記第１の段差形状部との接合部に位置するようにしたことを特徴とする請求項１に記載の電動弁。The welded portion between the can and the lid-like member is such that the center in the thickness direction of the lid-like member is located at the joint between the end surface on the opening side of the can and the first step shape portion. The motor-operated valve according to claim 1.