JP4461539B2

JP4461539B2 - Shut-off valve

Info

Publication number: JP4461539B2
Application number: JP36985499A
Authority: JP
Inventors: 正樹山口; 行則尾崎
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1999-12-27
Filing date: 1999-12-27
Publication date: 2010-05-12
Anticipated expiration: 2019-12-27
Also published as: JP2001182854A

Description

【０００１】
【発明の属する技術分野】
本発明は、ガス遮断装置の遮断機構として使用される遮断弁に関し、さらに詳しくは、流路に形成された弁座に対し弁体を前進または後退移動させることによって流路の遮断復帰動作を行うモータを動力源とした遮断弁に関するものである。
【０００２】
【従来の技術】
ガス事故を未然に防ぐため、従来より種種の安全装置が利用されており、中でもガスメータに内蔵され流量センサによりガスの流量を監視しマイクロコンピュータによりガスの使用状態を異常使用と判断した場合や、地震センサ、ガス圧力センサ、ガス警報器、一酸化炭素センサなどのセンサの状況を監視し危険状態と判断した場合は、ガスメータに内蔵された遮断弁によりガスを遮断する電池電源によるマイクロコンピュータ搭載ガス遮断装置内蔵ガスメータ（以下マイコンメータと省略する）は、安全性、ガス配管の容易性、低価格等の優位性のため、普及が促進され、近年ほぼ全世帯普及が実施されるに至っている。また、流量センサによって計測されたガス流量情報を電話回線などを利用して集中監視するテレメータ機能を有した、集中監視型マイコンメータの比率も増加し、ますます、情報端末として利便性の向上が求められている。この集中監視型マイコンメータなどにおいては、簡単な電気スイッチ操作や電話回線などによる遠隔操作でガスの遮断、復帰が可能なよう、マイコンメータに搭載した電池による電気エネルギーでガス遮断もガス復帰も可能で開弁状態と閉弁状態の保持はエネルギーを必要としない遮断弁が要求されている。
【０００３】
この遮断弁の駆動方式としては、従来電磁ソレノイドを使用したものが主流であったが、近年比較的強い閉止力、復帰力を実現でき、非通電時は状態保持可能なＰＭ型ステッピングモータを駆動源とする遮断弁が注目されており、なかでもロータをガス流路内、ステータをガス流路外とする気密隔壁を持った遮断弁が、ガス流路への取り付けが容易なため主流である。
【０００４】
以下に従来の遮断弁について説明する。
【０００５】
従来のこの種の遮断弁は、特開平９−６０７５２号公報、特開平１１−２３５１号公報に示すようなものが一般的であった。この特開平１１−２３５１号公報記載の遮断弁は図５に示されているように、鍔付きカップ状のケーシング６を有し、このケーシング６の外周にステータ４を装着し、前記ケーシング６の開口部にポリアセタール等の自己潤滑性のある合成樹脂製のアウターブッシュ３を嵌着し、このアウターブッシュ３にスタッド５を偏心させて前方に突設し、前記ケーシング６内にポリアセタール等の自己潤滑性のある合成樹脂製のインナーブッシュ１２を挿設し、前記アウターブッシュ３および前記インナーブッシュにリードスクリュー１７をその先端の雄ネジ部１７ａが当該アウターブッシュ３より前方に突出した状態で正逆方向に回転自在に支持し、このリードスクリュー１７にロータ１６を前記ステータ４に対向する形で取り付け、このロータ１６と前記アウターブッシュ３との間にスラスト荷重用ころがり軸受１８を介挿し、前記スタッド５に係合し雄ネジ部１７ａに螺合して弁体２５を配されている。
【０００６】
以上のように構成された遮断弁について、以下その動作について説明する。
【０００７】
ガスの異常使用時などには、図示していない制御部からの通電により、ロータ１６を正転させ、リードスクリュー１７が正方向に回転し、弁体２５がリードスクリュー１７側から弁座２６側に前進して弁座２６に当接することにより、流体経路を閉塞して流体を遮断する。また、これを復元するときには、外部入力によってリードスクリュー１７を逆方向に回転させ、弁体２５を弁座２６側からリードスクリュー１７側に後退させ、流体経路を開放して流体の供給を再開していた。
【０００８】
【発明が解決しようとする課題】
この遮断弁においては、電池という低エネルギーの電源で、ガスメータの使用期間（一般に１０年間）中特にメンテナンスしなくても動作するよう高い信頼性が要求されている。
【０００９】
しかしながら、上記の従来の遮断弁では、ケーシング６の底面の内径がロータ１６の外径とほぼ同じで広く、この底面の内径とほぼ同じ広い外径つばを有するインナーブッシュ１２を挿設していて、すなわち挿入締まり嵌めを行う前記つば部の外径が大きく締め応力がつば内部で緩和しやすく、つば部の軸方向の長さすなわち締め長さが小さく、またインナーブッシュ１２の材料であるポリアセタール等の自己潤滑製のある合成樹脂は柔らかく、クリープ変形しやすいため、締め代が小さい場合は長期の使用中の熱ストレス等で締まり嵌めが緩んでインナーブッシュ１２とケーシング６の同軸がくるい、ロータ１６がケーシング１２の内壁に接触して回転不能になったり、逆に締め代が大きい場合はインナーブッシュ１２のつば部が波打って変形しインナーブッシュ１２とケーシング６の同軸がくるいロータ１６がケーシング１２の内壁に接触して回転不能になったりする可能性があるという課題を有していた。
【００１０】
また、組立時インナーブッシュ１２はケーシング６の側面をこすりながらケーシング６の底面まで移動されるため、底面に到達するまでにインナーブッシュ１２のつば部外周が摩耗、変形し充分な締め応力を確保できなかったり、この移動中にケーシング６の側面が変形しロータ１６がケーシング１２の内壁に接触して回転不能になったりする可能性があるという課題を有していた。
【００１１】
さらに、インナーブッシュ１２やアウターブッシュ３とケーシング６と締め代が過多な場合はその応力で軸受孔径が縮小し、リードスクリュウ１７をロックする可能性があるという課題を有していた。
【００１２】
また、従来例には特に記載されていないが、ケーシング６がアルミニウム合金などステータ４の電磁ヨーク部材である鋼と異系列金属の場合は、水分などの付着により腐食電池が形成されやすく、ケーシング６が腐食されてガス漏れが発生する可能性があるという課題を有していた。
【００１３】
本発明はかかる従来の課題に鑑み、緩みにくく変形しにくく充分な締め代を実現でき、また軸孔に変形のおよびにくい軸受固定方法と、気密隔壁が腐食されにくく信頼性の高い遮断弁を提供することを目的とする。
【００１４】
【課題を解決するための手段】
本発明は上記課題を解決するために、ロータとステータとの気密を保持する隔壁を貫通穴のない２段の底を有するなべ状に成形されたものとし、合成樹脂製の第１の軸受をこの隔壁の小径のなべ側面に嵌挿して配し、概ねふた状の合成樹脂製の第２の軸受をこの隔壁の大径のなべ側面の開放端側に嵌挿して配したものである。
【００１５】
これによって、第１の軸受の挿入締まり嵌め部の径が細いため締め応力が緩和しにくく、比較的強い締め代を設定しても波打ちにくいため隔壁との同軸がくるいにくく、軸方向の締め長さを充分に確保でき、また、組立時に隔壁を変形させたり締まり嵌め部を摩耗しにくいため、緩みにくく変形しにくく充分な嵌合を実現でき、信頼性の高い遮断弁を実現できる。
【００１６】
また、第１または第２の軸受は、隔壁への嵌挿部と中心孔との間に応力緩和部を形成されていて、この応力緩和部によって挿入締まり嵌め部の締め応力が第１または第２の軸受の中心孔に伝達しにくいため、隔壁との締め代を大きく設定しても軸受孔径が縮小しにくく、充分な嵌合を実現でき、信頼性の高い遮断弁を実現できる。
【００１７】
また、隔壁が絞り成形されたオーステナイト系ステンレス鋼板であるため、ステータの電磁ヨーク部材である鋼との腐食による気密性の破壊を起こしにくく、信頼性の高い遮断弁を実現できる。
【００１８】
【発明の実施の形態】
本発明の遮断弁は、励磁コイルを有するステータと、前記ステータの内側に同軸に配され貫通穴のない２段の底を有するなべ状に成形された隔壁と、前記隔壁の小径のなべ側面に嵌挿された中心孔を有する合成樹脂製の第１の軸受と、前記隔壁の大径のなべ側面の開放端側に嵌挿された中心孔を有する概ねふた状の合成樹脂製の第２の軸受と、前記隔壁の内側に前記ステータに対向して配されたロータと、前記第１、第２の軸受に回転可能に緩挿された前記ロータの回転軸と、前記第２の軸受から外側に突出した前記回転軸に配された弁機構とで構成されたものである。そして、第１の軸受の挿入締まり嵌め部の径が細いため締め応力が緩和しにくく、比較的強い締め代を設定しても波打ちにくいため隔壁との同軸がくるいにくく、軸方向の締め長さを充分に確保でき、また、組立時に隔壁を変形させたり締まり嵌め部を摩耗しにくいため、緩みにくく変形しにくく充分な嵌合を実現でき、信頼性の高い遮断弁を実現できる。
【００１９】
また、本発明の遮断弁は、第１または第２の軸受は、隔壁への嵌挿部と中心孔との間に応力緩和部を形成されたものである。そして、この応力緩和部によって挿入締まり嵌め部の締め応力が第１または第２の軸受の中心孔に伝達しにくいため、隔壁との締め代を大きく設定しても軸受孔径が縮小しにくく、充分な嵌合を実現でき、信頼性の高い遮断弁を実現できる。
【００２０】
さらに、本発明の遮断弁は、隔壁が絞り成形されたオーステナイト系ステンレス鋼板であることを特徴とするものである。そして、この隔壁は腐食しにくく強い強度を有し、かつ、ステータの電磁ヨーク部材である鋼との腐食による気密性の破壊を起こしにくく、信頼性の高い遮断弁を実現できる。
【００２１】
【実施例】
以下、本発明の実施例について図面を用いて説明する。
【００２２】
（実施例１）
図１、図２、図３はそれぞれ本発明の実施例１の遮断弁の開弁状態、遮断動作中、閉弁状態の断面図である。
【００２３】
図１において、概ね糸巻き状のコイルボビン４１に導線４２が巻線された励磁コイル４３と、外周に円筒部を有し内周に櫛歯状の磁極を持った第１の電磁ヨーク４４と、この電磁ヨーク４４との間で励磁コイル４３を挟持するように配された概ね円盤状で内周に櫛歯状の磁極を持った第２の電磁ヨーク４５とのセットが２組、互いの第２の電磁ヨーク４５の円盤部を接触させて配されステータ４６を形成している。コイルボビン４１は合成樹脂製でポリブチレンテレフタレート（ＰＢＴ）のような耐熱性があり電気絶縁性の良好なものが望ましい。
【００２４】
第１の電磁ヨーク４４および第２の電磁ヨーク４５は、低炭素鋼板、電磁軟鉄板または硅素鋼板製などの鋼板製で、表面に亜鉛メッキやアルミニウムメッキ、クロム酸処理膜等の防錆処理を施されているか、もしくは電磁ステンレス鋼板製で、経済的には亜鉛メッキ鋼鈑などのプリメッキ鋼鈑が望ましい。第１の電磁ヨーク４４と第２の電磁ヨーク４５の櫛歯状の磁極は所定の隙間を持って噛合し、また２組のセットの櫛歯は、回転方向に他のセットの櫛歯のほぼ隙間部に位置するよう配置されている。
【００２５】
ステータ４６の内側に同軸に、２段の底４７ａ、４７ｂと、大小の円筒部４７ｃ、４７ｄ、大径の円筒部４７ｃの開放端につば４７ｅを有するなべ状に絞り成形された嵌通孔のない金属性の隔壁４７が配されている。隔壁４７の材料は、非磁性ステンレス鋼鈑、銅合金、アルミニウム合金、合成樹脂、セラミックスなどが選択可能であるが、耐腐食性、強度、耐クリープ、薄肉加工性などの理由から、オーステナイト系ステンレス鋼鈑を絞り加工したものが最適であり、絞り加工後固溶化熱処理を施し、残留する内部応力と結晶粒の微細化を除去したものが望ましい。
【００２６】
隔壁４７の小径の円筒部４７ｄなべ側面内側には、中心孔４８ａを有する合成樹脂製の第１の軸受４８が嵌挿されている。隔壁４７の円筒部４７ｄと第１の軸受４８は締まり嵌めで嵌合している。第１の軸受４８の嵌挿部４８ｂと中心孔４８ａとの間には、薄肉化した波紋状の応力緩和部４８ｃが形成されている。また、隔壁４７の底４７ａに当接するようストッパ４８ｄが形成されている。この第１の軸受４８の材料は、ポリアセタール（ＰＯＭ）、ポリアミド（ＰＡ）およびポリテトラフルオロエチレン（ＰＴＦＥ）粉末や黒鉛粒子を配合された各種合成樹脂などの、自己潤滑性を有する合成樹脂が選択可能であるが、摩擦係数の低さや経済的理由からポリアセタールが最適である。このポリアセタールは応力クリープが比較的大きく軟質であるため、締まり嵌めの嵌め合いを設定する場合は、比較的大きな締め代を設定する必要があり、例えば隔壁４７の円筒部４７ｄの内径が８mmである場合は第１の軸受４８の嵌挿部４８ｂの外径は８．０５〜８．１mm程度が適切である。
【００２７】
隔壁４７の大径の円筒部４７ｃのなべ側面の開放端側には、中心孔４９ａ、側面に円筒部４９ｂ、外周につば部４９ｃを同軸に有する概ねふた状の合成樹脂製の第２の軸受４９が、つば部４９ｃを隔壁４７のつば４７ｅに当接して嵌挿されている。隔壁４７の円筒部４７ｃと第２の軸受４９の嵌挿部４９ｅは締まり嵌めで嵌合している。第２の軸受４９の嵌挿部４９ｅと中心孔４９ａとの間には、薄肉化した波紋状の応力緩和部４９ｄが形成されている。
【００２８】
この第２の軸受４９の材料としては第１の軸受４８同様ポリアセタールが最適である。隔壁４７の円筒部４７ｃと第２の軸受４９の嵌挿部４９ｅとの締まり嵌めの嵌め合いは、後述する別の固定手段があるため、また円盤部４９ｆの波打ちを防止するために比較的ゆるめでよく、例えば隔壁４７の円筒部４７ｃの内径が１８mmである場合は第２の軸受４９の嵌挿部４９ｅの外径は１８．０２〜１８．０８程度が適切である。第２の軸受４９の円筒部４９ｂの内面には中心軸に平行な凸状のリブ５０が、円周上で１８０°離れた２カ所に形成されている。
【００２９】
隔壁４７の内側には、円周方向に分極着磁された円筒形の永久磁石５１と、一方の端に送りネジ５２を形成された回転軸５３と永久磁石５１と回転軸５３を同軸に保持するスリーブ５４とで構成されたロータ５５が、回転軸５３の送りネジ５２側端を第２の軸受４９の中心孔４９ａに、逆の端を第１の軸受４８の中心孔４８ａに回転可能に緩挿されて配されている。
【００３０】
流体室５６に取り付け可能な取り付け板５７は、中央に中心孔５７ａと隔壁４７の大径の円筒部４７ｃの外径より若干大きな内径を持った円筒状段差部５７ｂを形成され、外周部の２カ所に爪状の嵌合部５７ｃを形成されている。段差部５７ｂには隔壁４７の大径の円筒部４７ｃの端部が挿入され、第２の軸受４９の円筒部４９ｂが中心孔５７ａを貫通して流体室５６側に突出し、円筒部４７ｃの外周と段差部５７ｂの内周との間には、合成ゴム製Ｏリングなどの弾性体シール部材５８が隔壁４７の中心軸に対して円周方向に圧縮されて配されている。
【００３１】
第２の軸受４９のつば部４９ｃは、取り付け板５７の段差部５７ｂの底面５７ｄと隔壁４７のつば４７ｅとに挟まれて保持されている。取り付け板５７の隔壁４７側平面にはステータ４６が当接して配されていて、このステータ４６と隔壁４７を押しつけて取り付け板５７との間に挟み込んで、両端を取り付け板５７の嵌合部５７ｃに嵌合されて、概ねコの字形状の支持フレーム５９が配されている。支持フレーム５９にはステータ４６に係合可能な係合部５９ｂが形成され、ステータ４６の回転を防止している。
【００３２】
なお、この例では係合部５９ｂは背面から見ると凸字形状であり、先端部を電磁ヨーク４４に開口した孔に差し込んで係合し、凸字の段差部で電磁ヨーク４４を取り付け板５７側へ付勢している。ステータ４６とシール部材５８との間には、シール部材５８が取り付け板５７の段差部５７ｂから脱落することを防止するバックアップリング６０が配されている。取り付け板５７、支持フレーム５９の材質は表面処理された鋼板、ステンレス鋼板、銅合金板、アルミニウム合金板など耐ガス性、耐腐食性と、強度を持った材料なら特に指定はないが、経済的理由から表面処理された鋼板が選択しやすい。
【００３３】
流体室５６内に配された移動体６１は、中心孔６１ａが回転軸５３の送りネジ５４に螺合し、ステータ４６側に概ね円盤状のバネ受け６１ｂを形成され、他端に径の太い係合リング部６１ｃを形成され、それらの間に径の細い円筒部６１ｄを形成されている。バネ受け６１ｂの外周には、第２の軸受４９のリブ５０と係合可能な凹状部６１ｅ（図示せず）が、円周上で９０°の間隔に４カ所に成形されている。この凹状部６１ｅがリブ５０と係合することで、移動体６１と軸受４９との回転が防止され、送りネジ５４の回転動作が移動体６１の前後動作に変換される。移動体６１の材料は、ポリアセタール（ＰＯＭ）、ポリアミド（ＰＡ）およびポリテトラフルオロエチレン（ＰＴＦＥ）粉末や黒鉛粒子を配合された各種合成樹脂などの、自己潤滑性を有する合成樹脂が選択可能であるが、摩擦係数の低さや経済的理由からポリアセタールが最適である。
【００３４】
弁体６２は、流体室５６内に形成された弁座６５に当接可能な概ね円盤状で合成ゴムなどの可撓体性の弁シート６３と、弁シート６３のステータ４６側面に当接して配された合成樹脂など剛体製の弁シート保持部材６４とで構成されている。弁シート６３は貫通孔がなく、外周に係合リング部６３ａを形成し、弁シート保持部材６４を抱き込むようにして遊嵌している。
【００３５】
弁シート保護部材６４は、ステータ４６側に突出し、内径が移動体６１の係合リング部６１ｃの外径とほぼ等しく軸方向に縦割り６４ａが形成された円筒部６４ｂを有し、この円筒部６４ｂの端に、内径が移動体６１の係合リング部６１ｃ外径より細く移動体６１の円筒部６１ｄ外径とほぼ等しい、内側に突出した係合爪６４ｃを有し、移動体６１と係合して配されている。弁シート保持部材６４の円筒部６４ｂ先端と移動体６１のバネ受け６１ｂとの間には隙間６９が設けられている。弁シート保持部材６４の材料は、ポリアセタール（ＰＯＭ）、ポリアミド（ＰＡ）、ポリブチレンテレフタレート（ＰＢＴ）といった、耐ガス性を有する合成樹脂材料が望ましい。
【００３６】
移動体６１と弁シート保持部材６４との間には、弁シート保持部材６４の円筒部６４ｂ外径とほぼ等しい内径を有するコイルスプリング６６が圧縮して保持されている。
【００３７】
そして、この移動体６１と弁体６２とで弁機構を構成している。
【００３８】
ロータ５５のスリーブ５４と第１の軸受４８、第２の軸受４９との間には、ポリテトラフルオロエチレン（ＰＴＦＥ）や黒鉛粒子を配合したポリアミド（ＰＡ）などの自己潤滑性を有する合成樹脂製のスラストワッシャ６７、６８が配されている。
【００３９】
次にこの実施例１の遮断弁の動作、作用について説明する。
【００４０】
ガスの使用状態が異常でなく、各種センサーからの信号が危険を示していない時、マイコンメータの制御部（ここまで図示せず）からの通電はなく、遮断弁は図１に示したように移動体６１はステータ４６側にあり、弁体６２は弁座６５から離れた開弁状態を保持し、ガスが流通可能である。
【００４１】
ガスの使用状態が異常であるか、各種センサーからの信号が危険を示している時、マイコンメータの制御部は励磁コイル４３の各導線４２に位相差を持ったパルス状電流を印加し、ロータ５５を正回転させる。移動体６１は凹状部６１ｅがリブ５０と係合し回転を防止されているため、ロータ５５に連動した送りネジ５４の回転動作は移動体６１の前後動作に変換され、移動体６１と係合している弁体６２は、弁シート６３が弁座６５に当接する位置に移動し、図２に示した状態になる。
【００４２】
さらに移動体６１が弁座６５側に前進すると、コイルスプリング６６がより圧縮され、弁シート保持部材６４の円筒部６４ｂ先端と移動体６１のバネ受け６１ｂとが当接し、弁シート６３が撓み、圧縮され、ついに移動体６１の反発力が送りネジ５４の推力より大きくなり、ロータ５５の回転が停止する。こうして、弁体６２は弁座６５にコイルスプリング６６で付勢され、ガスが遮断される。この閉弁状態の遮断弁を図３に示した。
【００４３】
この後、マイコンメータの制御部が通電を停止しても、ロータ５５は保持トルクのため状態を保持し、したがって弁体６２は弁座６５にコイルスプリング６６で付勢された閉弁状態を保持する。
【００４４】
各種センサーからの信号から危険が解除され復帰可能とマイコンメータの制御部が判断した場合や、ガス利用者が危険状態を復旧し、メータやリモートコントロール盤に設けられた復帰スイッチを操作した場合、ガス供給業者などが通信による遠隔復帰命令を発信した場合などには、マイコンメータの制御部は励磁コイル４３の各導線４２に逆位相差を持ったパルス状電流を印加し、ロータ５５を逆回転させる。
【００４５】
すると送りネジ５４に送られて移動体６１はステータ４６側に移動し、弁体６２は弁座６５から離脱し、ガスが流通可能になる。移動体６１はさらにステータ４６側に移動し、ついに移動体６１が第２の軸受４９に当接し移動下死点となってロータ５５の回転が停止する。この後マイコンメータの制御部が通電を停止しても、ロータ５５は保持トルクのため状態を保持し、図１に示した開弁状態を保持する。
【００４６】
さて、この種の遮断弁が熱ストレスを受けた場合、第１の軸受４８は膨張収縮を繰り返し、一方隔壁４７は金属製のため膨張収縮量が小さく、特に高温時は第１の軸受４８は膨張しようとするにもかかわらず隔壁４７があまり膨張しないため第１の軸受４８の嵌挿部４８ｂは内部応力が小さくなる方向にクリープ変形し、この結果長期の使用期間中に第１の軸受４８と隔壁４７の嵌合が緩む問題点があるが、本実施例の遮断弁は、第１の軸受４８の嵌挿部４８ｂの径が細いため熱による膨張量が小さく、結果として熱ストレスによって締め応力が緩和しにくい。
【００４７】
また、比較的強い締め代を設定しても、嵌挿部４８ｂの径が細いため波打ちににくく、隔壁との同軸がくるいにくい。また、隔壁４７が２段の底を有するなべ状に成形されており、この小径側のなべ側面に第１の軸受４８を嵌挿する形態であり、ロータ４６の入る大径のなべ側面４７ｃには影響を及ぼさないため、第１の軸受４８の軸方向の締め長さ、すなわち嵌挿部４８ｂの長さを充分に確保できる。また、組立時に隔壁４７の大径のなべ側面４７ｃを変形させたり第１の軸受４８の嵌挿部４８ｂを摩耗しにくいため、緩みにくく変形しにくく充分な嵌合を実現できる。このように、熱ストレスの影響を受けにくい嵌挿部を設定可能であり、信頼性の高い遮断弁を実現できる。
【００４８】
また、遮断弁が高温熱ストレスを受けた場合、第１の軸受４８または第２の軸受４９は外側に膨張しようとするにもかかわらず隔壁４７があまり膨張しないため内側に膨張する方向の応力となる。また、第１の軸受４８または第２の軸受４９を隔壁４７に嵌挿する際の応力も、同様に内側に膨張する方向の応力となる。このときもし、第１の軸受またはまたは第２の軸受が単なる円筒ブッシングの形状であったなら、中心孔が縮小する方向に変形し、回転軸５３をロックする可能性がある。
【００４９】
しかしながら、本実施例の遮断弁は、第１の軸受４８の嵌挿部４８ｂと中心孔４８ａとの間に薄肉化した波紋状の応力緩和部４８ｃが形成されていて、また、第２の軸受４９の嵌挿部４９ｅと中心孔４９ａとの間に薄肉化した波紋状の応力緩和部４９ｄが形成されているため、嵌挿部４８ｂ、４９ｅの内側に膨張しようとする応力は応力緩和部４８ｃ、４９ｄで薄肉の部分を曲げる方向の応力に変換され、内側の中心孔４８ａ、４９ａへの影響が少ない。
【００５０】
このため、隔壁４７との締め代を大きく設定しても中心孔４８ａ、４９ａの径が縮小しにくく充分な嵌合を実現でき、熱ストレスによる径の縮小も発生しにくいため、回転軸５３がロックしにくい信頼性の高い遮断弁を実現できる。
【００５１】
また、隔壁４７の外側、すなわちステータ４６側は、ガスメータに取り付けられた場合空気側になり、ガスメータが屋外に設置された場合、高湿な環境にさらされることになる。この高湿環境下で長時間使用されると、隔壁の材料の耐食性が悪い場合や電磁ヨーク４４および４５との腐食電位が大きく異なる場合などは、腐食電池を形成して腐食によって隔壁に穴があき気密性が破壊しガス漏れが発生する危険があるが、本実施例の遮断弁は、隔壁４７が絞り成形されたオーステナイト系ステンレス鋼板であるため、ステータ４６の電磁ヨーク部材である鋼との腐食による気密性の破壊を起こしにくく、信頼性の高い遮断弁を実現できる。
【００５２】
なお、図１において、励磁コイル４３、第１の電磁ヨーク４４、第２の電磁ヨーク４５のセットは２セットとしたが、３セットでも、より多数でもよい。また、ステータ４６、隔壁４７は支持フレーム５９で取り付け板５７に嵌着するとしたが、支持フレームがなく相互に溶接で固定されていてもよい。また、第２の軸受４９にリブ５０を設け、移動体６１に凹状部６１ｅを設けるとしたが、第２の軸受に溝を設け、移動体に凸状部を設けて係合させ回転防止手段としてもよく、取り付け板もしくは第２の軸受に中心からオフセットした棒を突出させ、移動体に穴もしくは溝を形成し係合させることによって回転防止手段としてもよい。
【００５３】
また、スラスト軸受は滑り軸受であるスラストワッシャ６７、６８としたが、ボールベアリングなどの転がり軸受でもよい。ただし、マイコンメータの遮断弁の場合は、長期間にわたって開弁静止状態で放置されることが多いため、潤滑油の使用は好ましくない。また、直動機構は送りネジ５２と移動体６１の係合部とのネジ機構としたが円筒カム機構でもよく、送りネジ５２は回転軸５３に形成しているが、回転軸から減速機構を経て直動機構へ入力してもよい。
【００５４】
また、弁体６２と移動体６１とは別部品としたが、一体的に構成されてもよい。弁シート６３は弁シート保持部材６４を抱き込んでいるとしたが、中央で嵌合してもよく、弁シート保持部材に中心軸を形成して弁シートを気密に貫通させ別の固定部材で締結してもよい。
【００５５】
（実施例２）
図４は本発明の実施例２の遮断弁の開弁状態の断面図である。
【００５６】
ステータ４６の内側に、２段の底と、大小の円筒部７２ａ、７２ｂと、大径の円筒部７２ａの開放端に大径のつば７２ｃを有する貫通孔のないなべ状に成形された隔壁が７２配されている。隔壁７２の小径の円筒部７２ｂ内面にスリーブ状の合成樹脂製の第１の軸受７３が嵌挿されている。隔壁７２の大径の円筒部７２ａの開放端にはふた状の合成樹脂製の第２の軸受７４が嵌挿されている。第２の軸受７４には中心軸からオフセットしてピン７５が配されている。隔壁７２の内部には、送りネジ７７を第２の軸受７４から突出させて、ロータ７６が配されている。
【００５７】
隔壁７２のつば７２ｃとステータ４６との間には、つば７２ｃとほぼ同じ形状の取り付け板７８が配され、流体室５６とつば７２ｃとの間に合成ゴム製Ｏリングなどのシール部材７９を挟んだ状態で、取り付け板７８と隔壁７２は流体室５６にネジなどで締結されている。また、第２の軸受７２の外周も同時につば７２ｃと流体室５６との間に挟持されている。取り付け板７８とステータ４６、ステータ４６の各電磁ヨークは、それぞれ相互に溶接で固着されている。
【００５８】
弁体８０は弁シート８１と弁シート保持部材８２で構成され、弁体８０の凹部に弁シート保持部材８２の凸部が挿着されている。弁シート保持部材８２のロータ４６側には送りネジ７７と螺合可能な雌ねじ８２ａと、ピン７５と係合可能なガイド溝８２ｂが形成されている。
【００５９】
なお、実施例１と同一符号のものは同一構造を有し、説明は省略する。また、各部詳細は第１実施例と同様のため、説明は省略する。
【００６０】
この遮断弁の動作は、実施例１とほぼ同じであるので、詳細の説明を省略する。実施例１と異なるのは、この遮断弁は弁体８０と移動体（雌ねじ８２ａ）が一体的に構成されていてコイルスプリングがないため、遮断動作は、ロータ７６が回転し、弁体８０が移動して弁座６５に当接し、弁シート８１が撓んで、ロータ７６の回転が停止することで完了することである。この遮断弁は、閉弁時の弁体の締めきりを弁シート８１の弾性力に頼っているので、コイルスプリング６６で安定した付勢力を与える実施例１と比較して、閉弁安定性が若干劣っているが、部品点数が削減できるので経済的な効果はある。
【００６１】
次に、実施例２記載の遮断弁の作用について説明する。この遮断弁は隔壁７２の小径の円筒部７２ｂの軸方向長さが長いため、比較的ゆるい嵌合でも熱ストレスの影響を受けにくい嵌挿部を設定可能であり、この例のようなスリーブ状の第１の軸受７３の設定も可能となる。そして、比較的ゆるい嵌合でもよいことから、第１の軸受７３の中心孔径が縮小しにくい。
【００６２】
第２の軸受７４と隔壁７２のつば７２ｃは共に取り付け板７８と流体室５６とに挟まれて固定されているため、第２の軸受７４と隔壁７２の大径の円筒部７２ａとの嵌合はゆるくてよく、第２の軸受７４の中心孔径が縮小しにくい。また、隔壁７２のつば７２ｃと流体室５６との間に設けたシール部材７９のみがガスシール部となり、シール箇所が少ないため、信頼性の高い気密構造となっている。
【００６３】
このように、実施例２の遮断弁は、少ない部品点数の簡単な構造で、信頼性の高い軸受と気密構造の遮断弁を実現できる。
【００６４】
なお、回転防止手段であるピン７５は第２の軸受７２と一体に形成してもよい。
【００６５】
【発明の効果】
以上のように本発明によれば、隔壁を２段の底を有するなべ状に成形し、合成樹脂製の第１の軸受をこの隔壁の小径のなべ側面に嵌挿し、概ねふた状の合成樹脂製の第２の軸受をこの隔壁の大径のなべ側面の開放端側に嵌挿して構成したことにより、第１の軸受の挿入締まり嵌め部の径が細いため締め応力が緩和しにくく、比較的強い締め代を設定しても波打ちにくいため隔壁との同軸がくるいにくく、軸方向の締め長さを充分に確保でき、また、組立時に隔壁を変形させたり締まり嵌め部を摩耗しにくいため、緩みにくく変形しにくく充分な嵌合を実現でき、信頼性の高い遮断弁を実現できるといった有利な効果を有する。
【００６６】
また、第１または第２の軸受に、隔壁への嵌挿部と中心孔との間に応力緩和部を形成したことによって、この応力緩和部によって挿入締まり嵌め部の締め応力が第１または第２の軸受の中心孔に伝達しにくいため、隔壁との締め代を大きく設定しても軸受孔径が縮小しにくく、充分な嵌合を実現でき、信頼性の高い遮断弁を実現できるといった有利な効果を有する。
【００６７】
また、隔壁を絞り成形されたオーステナイト系ステンレス鋼板としたことによって、隔壁が腐食しにくく強い強度を有し、かつ、ステータの電磁ヨーク部材である鋼との腐食による気密性の破壊を起こしにくく、信頼性の高い遮断弁を実現できるといった有利な効果を有する。
【図面の簡単な説明】
【図１】本発明の実施例１の遮断弁の開弁状態の断面図
【図２】同遮断弁の遮断動作中の断面図
【図３】同遮断弁の閉弁状態の断面図
【図４】本発明の実施例２の遮断弁の開弁状態の断面図
【図５】従来の遮断弁の開弁状態の断面図
【符号の説明】
４３励磁コイル
４６ステータ
４７、７２隔壁
４８、７３第１の軸受
４８ａ中心孔
４８ｂ嵌挿部
４８ｃ応力緩和部
４９、７４第２の軸受
５５、７６ロータ
５３回転軸
６１移動体（弁機構）
６２、８０弁体（弁機構）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shut-off valve used as a shut-off mechanism of a gas shut-off device. More specifically, the shut-off operation of a flow path is performed by moving a valve body forward or backward relative to a valve seat formed in the flow path. The present invention relates to a shut-off valve using a motor as a power source.
[0002]
[Prior art]
In order to prevent gas accidents, various types of safety devices have been used in the past.In particular, when the flow rate sensor built in the gas meter monitors the gas flow rate and the microcomputer determines that the gas usage status is abnormal, Microcomputer-equipped gas with a battery power source that shuts off the gas with a shut-off valve built in the gas meter when the status of sensors such as earthquake sensors, gas pressure sensors, gas alarms, carbon monoxide sensors, etc. The gas meter with built-in shut-off device (hereinafter abbreviated as microcomputer meter) has been promoted for its advantages such as safety, ease of gas piping, and low price, and in recent years, almost all households have become popular. In addition, the ratio of centralized monitoring micrometers that have a telemeter function that centrally monitors the gas flow rate information measured by the flow sensor using a telephone line will increase, and the convenience of information terminals will increase. It has been demanded. In this central monitoring type microcomputer meter, etc., gas can be shut off and restored by electric energy from the battery installed in the microcomputer meter so that gas can be shut off and restored by simple electric switch operation or remote operation by telephone line etc. On the other hand, a shut-off valve that does not require energy is required to maintain the open and closed states.
[0003]
As the drive system for this shut-off valve, the one that used an electromagnetic solenoid has been the mainstream. However, in recent years, a relatively strong closing force and return force can be realized. A shut-off valve with a gas-tight partition with the rotor inside the gas flow path and the stator outside the gas flow path is the mainstream because it is easy to attach to the gas flow path. .
[0004]
A conventional shut-off valve will be described below.
[0005]
Conventional shut-off valves of this type are generally shown in Japanese Patent Laid-Open Nos. 9-60752 and 11-2351. As shown in FIG. 5, the shut-off valve described in Japanese Patent Laid-Open No. 11-2351 has a cup-shaped casing 6 with a hook, and a stator 4 is mounted on the outer periphery of the casing 6. A self-lubricating synthetic resin outer bush 3 such as polyacetal is fitted into the opening, and a stud 5 is eccentrically projected to the outer bush 3 so as to project forward, and self-lubricating polyacetal or the like in the casing 6. The inner bush 12 made of synthetic resin is inserted, the lead screw 17 is inserted into the outer bush 3 and the inner bush, and the male thread portion 17a at the tip projects forward from the outer bush 3 in the forward and reverse directions. The rotor 16 is attached to the lead screw 17 so as to face the stator 4. The interposed bearing 18 rolling for thrust load between the outer bushing 3, engaged with the stud 5 is arranged a valve body 25 screwed to the male screw portion 17a and.
[0006]
The operation of the shut-off valve configured as described above will be described below.
[0007]
When the gas is abnormally used, the rotor 16 is rotated forward by energization from a control unit (not shown), the lead screw 17 rotates in the forward direction, and the valve body 25 is moved from the lead screw 17 side to the valve seat 26 side. By moving forward and abutting on the valve seat 26, the fluid path is closed to shut off the fluid. When restoring this, the lead screw 17 is rotated in the reverse direction by an external input, the valve body 25 is retracted from the valve seat 26 side to the lead screw 17 side, the fluid path is opened, and the fluid supply is resumed. It was.
[0008]
[Problems to be solved by the invention]
This shut-off valve is required to have high reliability so that it operates without any maintenance during the period of use of the gas meter (generally 10 years) with a low energy power source called a battery.
[0009]
However, in the above-described conventional shut-off valve, the inner bush 12 having a wide outer diameter collar which is substantially the same as the inner diameter of the bottom surface of the casing 6 and the outer diameter of the rotor 16 is wide. In other words, the outer diameter of the collar portion to be inserted and fitted is large, and the tightening stress is easily relieved inside the collar, the axial length of the collar portion, that is, the tightening length is small, and polyacetal which is the material of the inner bush 12 Since a synthetic resin made of self-lubricating is soft and easily deforms by creep, when the tightening margin is small, the interference fit is loosened due to thermal stress during long-term use, and the inner bush 12 and the casing 6 are concentric. When 16 comes into contact with the inner wall of the casing 12 so that it cannot rotate, or conversely, the allowance is large, the flange portion of the inner bush 12 is wavy. Coaxial deviation rotor 16 forms with the inner bushing 12 and the casing 6 there is a problem that is likely to or become unable to rotate in contact with the inner wall of the casing 12.
[0010]
Further, since the inner bush 12 is moved to the bottom surface of the casing 6 while rubbing the side surface of the casing 6 at the time of assembly, the outer periphery of the collar portion of the inner bush 12 is worn and deformed before reaching the bottom surface, and sufficient tightening stress can be secured. There is a problem that the side surface of the casing 6 may be deformed during the movement, and the rotor 16 may come into contact with the inner wall of the casing 12 to be unable to rotate.
[0011]
Furthermore, when the inner bush 12 or the outer bush 3 and the casing 6 are excessively tightened, the bearing hole diameter is reduced by the stress, and the lead screw 17 may be locked.
[0012]
Although not particularly described in the conventional example, when the casing 6 is made of steel and a different series metal such as an aluminum alloy such as an aluminum alloy member of the stator 4, a corrosion cell is easily formed due to adhesion of moisture or the like. Has a problem that gas leaks may occur due to corrosion.
[0013]
In view of such conventional problems, the present invention provides a bearing fixing method that is difficult to loosen and is not easily deformed, and that has sufficient tightening allowance, and that is difficult to be deformed in the shaft hole, and a highly reliable shutoff valve that is resistant to corrosion of the airtight partition wall. The purpose is to do.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention assumes that the partition for maintaining the airtightness between the rotor and the stator is formed into a pan-like shape having a two-stage bottom without a through hole, and the first bearing made of synthetic resin is provided. The partition is fitted and arranged on a small-diameter pan side surface, and a second lid made of a synthetic resin having a generally lid shape is fitted and arranged on the open end side of the large-diameter pan side surface of the partition wall.
[0015]
As a result, the diameter of the insertion interference fitting portion of the first bearing is thin, so that the tightening stress is difficult to relax. Sufficient length can be secured, and since the partition wall is not easily deformed or the interference fitting portion is hardly worn during assembly, it is difficult to loosen and hardly deform, and a sufficient fitting can be realized, and a highly reliable shut-off valve can be realized.
[0016]
In the first or second bearing, a stress relaxation portion is formed between the insertion portion to the partition wall and the center hole, and the tightening stress of the insertion interference fit portion is reduced by the stress relaxation portion. Since it is difficult to transmit to the center hole of No. 2 bearing, the bearing hole diameter is difficult to be reduced even if the interference with the partition wall is set large, and sufficient fitting can be realized, and a highly reliable shut-off valve can be realized.
[0017]
Further, since the partition wall is an austenitic stainless steel plate formed by drawing, it is difficult to cause hermetic breakdown due to corrosion with steel that is an electromagnetic yoke member of the stator, and a highly reliable shut-off valve can be realized.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The shut-off valve of the present invention includes a stator having an exciting coil, a partition wall that is coaxially arranged inside the stator and has a two-stage bottom having no through hole, and a small-diameter pan side surface of the partition wall. A first synthetic resin bearing having a central hole inserted therein, and a second generally made lid-shaped synthetic resin having a central hole inserted into the open end side of the large-diameter pan side surface of the partition wall. A bearing, a rotor disposed inside the partition so as to face the stator, a rotation shaft of the rotor loosely inserted into the first and second bearings, and an outer side from the second bearing And a valve mechanism disposed on the rotating shaft that protrudes from the center. Since the diameter of the insertion interference fit portion of the first bearing is thin, it is difficult to relieve the tightening stress, and even if a relatively strong tightening margin is set, it is difficult to corrugate with the partition wall. In addition, since the partition wall is not deformed or the interference fitting portion is hardly worn during assembly, it is difficult to loosen and deform easily, and a sufficient fitting can be realized, and a highly reliable shut-off valve can be realized.
[0019]
In the shut-off valve of the present invention, the first or second bearing has a stress relaxation portion formed between the insertion portion into the partition wall and the center hole. Since the tightening stress of the insertion interference fitting portion is not easily transmitted to the center hole of the first or second bearing by the stress relaxation portion, the bearing hole diameter is not easily reduced even if the tightening allowance with the partition wall is set large. Can be realized, and a highly reliable shut-off valve can be realized.
[0020]
Furthermore, the shut-off valve of the present invention is an austenitic stainless steel sheet in which the partition wall is drawn. This partition wall is hard to be corroded and has a strong strength, and it is difficult to cause hermeticity damage due to corrosion with steel which is an electromagnetic yoke member of the stator, thereby realizing a highly reliable shut-off valve.
[0021]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
Example 1
1, FIG. 2, and FIG. 3 are cross-sectional views of the shut-off valve according to the first embodiment of the present invention in the open state, during the shut-off operation, and in the closed state, respectively.
[0023]
In FIG. 1, an exciting coil 43 in which a conducting wire 42 is wound on a substantially bobbin-shaped coil bobbin 41, a first electromagnetic yoke 44 having a cylindrical portion on the outer periphery and a comb-shaped magnetic pole on the inner periphery, Two sets of the second electromagnetic yoke 45 having a generally disc shape and a comb-shaped magnetic pole on the inner periphery, which are arranged so as to sandwich the exciting coil 43 between the electromagnetic yoke 44 and the second one, are mutually connected. The electromagnetic yoke 45 is arranged in contact with the disk portion to form a stator 46. The coil bobbin 41 is preferably made of synthetic resin and has heat resistance such as polybutylene terephthalate (PBT) and good electrical insulation.
[0024]
The first electromagnetic yoke 44 and the second electromagnetic yoke 45 are made of a steel plate such as a low-carbon steel plate, an electromagnetic soft iron plate, or a silicon steel plate, and are subjected to rust prevention treatment such as galvanization, aluminum plating, and chromic acid treatment film on the surface. Economically, a pre-plated steel plate such as a galvanized steel plate is desirable. The comb-shaped magnetic poles of the first electromagnetic yoke 44 and the second electromagnetic yoke 45 mesh with a predetermined gap, and the two sets of comb teeth are substantially the same as the other sets of comb teeth in the rotation direction. It arrange | positions so that it may be located in a clearance gap part.
[0025]
Coaxially inside the stator 46, there are two stages of bottom holes 47a and 47b, large and small cylindrical portions 47c and 47d, and a large diameter cylindrical portion 47c with a flange 47e at the open end of the large diameter cylindrical portion 47c. There is no metallic partition 47. The material of the partition wall 47 can be selected from non-magnetic stainless steel plate, copper alloy, aluminum alloy, synthetic resin, ceramics, etc., but for reasons such as corrosion resistance, strength, creep resistance, thin wall workability, austenitic stainless steel A steel plate that has been drawn is optimal, and a solution that has been subjected to solution heat treatment after drawing to remove residual internal stress and crystal grain refinement is desirable.
[0026]
A first bearing 48 made of synthetic resin having a center hole 48a is fitted into the inside of the side surface of the small-diameter cylindrical portion 47d of the partition wall 47. The cylindrical portion 47d of the partition wall 47 and the first bearing 48 are fitted with an interference fit. Between the fitting portion 48b of the first bearing 48 and the center hole 48a, a thin rippled stress relaxation portion 48c is formed. Further, a stopper 48d is formed so as to contact the bottom 47a of the partition wall 47. The material of the first bearing 48 is selected from synthetic resins having self-lubricating properties such as various synthetic resins in which polyacetal (POM), polyamide (PA) and polytetrafluoroethylene (PTFE) powder and graphite particles are blended. Although possible, polyacetal is the best because of its low coefficient of friction and economic reasons. Since this polyacetal has a relatively large stress creep and is soft, when setting an interference fit, it is necessary to set a relatively large allowance. For example, the inner diameter of the cylindrical portion 47d of the partition wall 47 is 8 mm. In this case, the outer diameter of the fitting portion 48b of the first bearing 48 is appropriately about 8.05 to 8.1 mm.
[0027]
On the open end side of the side surface of the large-diameter cylindrical portion 47c of the partition wall 47, there is a central hole 49a, a cylindrical portion 49b on the side surface, and a flange portion 49c on the outer periphery. 49 is fitted in such a manner that the collar portion 49 c abuts on the collar 47 e of the partition wall 47. The cylindrical portion 47c of the partition wall 47 and the fitting insertion portion 49e of the second bearing 49 are fitted with an interference fit. Between the fitting portion 49e of the second bearing 49 and the center hole 49a, a thin rippled stress relaxation portion 49d is formed.
[0028]
As the material of the second bearing 49, polyacetal is optimal as in the first bearing 48. The interference fit between the cylindrical portion 47c of the partition wall 47 and the insertion portion 49e of the second bearing 49 is relatively loosened because there is another fixing means described later and to prevent the disk portion 49f from wavy. For example, when the inner diameter of the cylindrical portion 47c of the partition wall 47 is 18 mm, the outer diameter of the fitting insertion portion 49e of the second bearing 49 is appropriately about 18.02 to 18.08. On the inner surface of the cylindrical portion 49b of the second bearing 49, convex ribs 50 parallel to the central axis are formed at two locations 180 ° apart on the circumference.
[0029]
Inside the partition wall 47, a cylindrical permanent magnet 51 polarized in the circumferential direction, a rotating shaft 53 having a feed screw 52 formed at one end, the permanent magnet 51, and the rotating shaft 53 are held coaxially. The rotor 55 configured by the sleeve 54 is configured to be able to rotate at the feed screw 52 side end of the rotary shaft 53 to the center hole 49a of the second bearing 49 and the opposite end to the center hole 48a of the first bearing 48. Loosely inserted.
[0030]
A mounting plate 57 that can be attached to the fluid chamber 56 is formed with a cylindrical stepped portion 57b having an inner diameter slightly larger than the outer diameter of the central hole 57a and the large-diameter cylindrical portion 47c of the partition wall 47 at the center. A claw-like fitting part 57c is formed at the place. The end of the large-diameter cylindrical portion 47c of the partition wall 47 is inserted into the stepped portion 57b, and the cylindrical portion 49b of the second bearing 49 passes through the center hole 57a and protrudes toward the fluid chamber 56, and the outer periphery of the cylindrical portion 47c. An elastic seal member 58 such as a synthetic rubber O-ring is compressed in the circumferential direction with respect to the central axis of the partition wall 47 between the inner periphery of the stepped portion 57b.
[0031]
The flange portion 49 c of the second bearing 49 is held between the bottom surface 57 d of the stepped portion 57 b of the mounting plate 57 and the flange 47 e of the partition wall 47. A stator 46 is disposed in contact with the partition plate 47 side surface of the mounting plate 57. The stator 46 and the partition wall 47 are pressed against each other and sandwiched between the mounting plate 57 and both ends thereof are fitted portions 57c of the mounting plate 57. A generally U-shaped support frame 59 is disposed. The support frame 59 is formed with an engaging portion 59 b that can be engaged with the stator 46 to prevent the stator 46 from rotating.
[0032]
In this example, the engaging portion 59b has a convex shape when viewed from the back, and the front end portion is inserted into and engaged with a hole opened in the electromagnetic yoke 44, and the electromagnetic yoke 44 is attached to the mounting plate 57 by the convex stepped portion. It is energizing to the side. Between the stator 46 and the seal member 58, a backup ring 60 for preventing the seal member 58 from dropping from the stepped portion 57b of the mounting plate 57 is disposed. The material of the mounting plate 57 and the support frame 59 is not particularly specified as long as it is a material having gas resistance, corrosion resistance and strength such as surface-treated steel plate, stainless steel plate, copper alloy plate, aluminum alloy plate, etc., but economical. It is easy to select a surface-treated steel sheet for the reason.
[0033]
The moving body 61 disposed in the fluid chamber 56 has a center hole 61a screwed into the feed screw 54 of the rotating shaft 53, a substantially disk-shaped spring receiver 61b formed on the stator 46 side, and a large diameter at the other end. An engagement ring portion 61c is formed, and a cylindrical portion 61d having a small diameter is formed between them. On the outer periphery of the spring receiver 61b, concave portions 61e (not shown) that can engage with the ribs 50 of the second bearing 49 are formed at four locations at intervals of 90 ° on the circumference. When the concave portion 61 e is engaged with the rib 50, the rotation of the moving body 61 and the bearing 49 is prevented, and the rotation operation of the feed screw 54 is converted into the front-rear operation of the moving body 61. The material of the moving body 61 can be selected from synthetic resins having self-lubricating properties such as polyacetal (POM), polyamide (PA), polytetrafluoroethylene (PTFE) powder, and various synthetic resins blended with graphite particles. However, polyacetal is optimal because of its low friction coefficient and economic reasons.
[0034]
The valve body 62 is in contact with a side surface of the stator 46 of the valve seat 63 and a flexible valve seat 63 made of synthetic rubber or the like that is substantially disc-shaped and capable of coming into contact with a valve seat 65 formed in the fluid chamber 56. It comprises a rigid valve seat holding member 64 such as a synthetic resin. The valve seat 63 does not have a through hole, and an engagement ring portion 63 a is formed on the outer periphery, and the valve seat 63 is loosely fitted so as to embrace the valve seat holding member 64.
[0035]
The valve seat protection member 64 has a cylindrical portion 64b that protrudes toward the stator 46 and has an inner diameter that is substantially equal to the outer diameter of the engagement ring portion 61c of the moving body 61 and is formed with a longitudinally split 64a in the axial direction. At the end of 64 b, there is an engaging claw 64 c projecting inward that has an inner diameter smaller than the outer diameter of the engaging ring portion 61 c of the moving body 61 and substantially equal to the outer diameter of the cylindrical portion 61 d of the moving body 61. It is arranged together. A gap 69 is provided between the tip of the cylindrical portion 64 b of the valve seat holding member 64 and the spring receiver 61 b of the moving body 61. The material of the valve seat holding member 64 is preferably a synthetic resin material having gas resistance such as polyacetal (POM), polyamide (PA), polybutylene terephthalate (PBT).
[0036]
A coil spring 66 having an inner diameter substantially equal to the outer diameter of the cylindrical portion 64 b of the valve seat holding member 64 is compressed and held between the moving body 61 and the valve seat holding member 64.
[0037]
The moving body 61 and the valve body 62 constitute a valve mechanism.
[0038]
A synthetic resin having a self-lubricating property such as polytetrafluoroethylene (PTFE) or polyamide (PA) blended with graphite particles is provided between the sleeve 54 of the rotor 55 and the first bearing 48 and the second bearing 49. Thrust washers 67 and 68 are arranged.
[0039]
Next, the operation and action of the shutoff valve of the first embodiment will be described.
[0040]
When the gas usage state is not abnormal and the signals from various sensors do not indicate danger, there is no power supply from the control unit (not shown so far) of the microcomputer meter, and the shut-off valve is as shown in FIG. The moving body 61 is on the stator 46 side, the valve body 62 is kept open from the valve seat 65, and gas can flow therethrough.
[0041]
When the usage state of the gas is abnormal or the signals from various sensors indicate danger, the control unit of the microcomputer meter applies a pulsed current having a phase difference to each conductive wire 42 of the exciting coil 43, and the rotor 55 is rotated forward. Since the moving body 61 is prevented from rotating because the concave portion 61 e is engaged with the rib 50, the rotation operation of the feed screw 54 interlocked with the rotor 55 is converted into the front-rear operation of the moving body 61 and is engaged with the moving body 61. The valve body 62 is moved to a position where the valve seat 63 abuts on the valve seat 65, and is in the state shown in FIG.
[0042]
When the moving body 61 further advances toward the valve seat 65, the coil spring 66 is further compressed, the tip of the cylindrical portion 64b of the valve seat holding member 64 and the spring receiver 61b of the moving body 61 come into contact, and the valve seat 63 bends. As a result, the repulsive force of the moving body 61 finally becomes larger than the thrust of the feed screw 54, and the rotation of the rotor 55 is stopped. Thus, the valve body 62 is urged against the valve seat 65 by the coil spring 66 and the gas is shut off. The shut-off valve in the closed state is shown in FIG.
[0043]
Thereafter, even if the control unit of the microcomputer meter stops energization, the rotor 55 maintains the state due to the holding torque, and therefore the valve body 62 maintains the closed state in which the valve seat 65 is urged by the coil spring 66. To do.
[0044]
When the controller of the microcomputer meter determines that the danger is released from the signals from the various sensors and can be restored, or when the gas user recovers the dangerous condition and operates the return switch provided on the meter or remote control panel, When a gas supplier or the like sends a remote return command by communication, the control unit of the microcomputer meter applies a pulsed current having an opposite phase difference to each conducting wire 42 of the exciting coil 43 and rotates the rotor 55 in the reverse direction. Let
[0045]
Then, it is sent to the feed screw 54 and the moving body 61 moves to the stator 46 side, the valve body 62 is detached from the valve seat 65, and the gas can flow. The moving body 61 further moves to the stator 46 side. Finally, the moving body 61 comes into contact with the second bearing 49 and becomes a moving bottom dead center, and the rotation of the rotor 55 is stopped. Thereafter, even if the control unit of the microcomputer meter stops energization, the rotor 55 maintains the state due to the holding torque, and maintains the valve open state shown in FIG.
[0046]
When this type of shut-off valve is subjected to thermal stress, the first bearing 48 repeatedly expands and contracts. On the other hand, the partition wall 47 is made of metal, so the amount of expansion and contraction is small. Although the partition wall 47 does not expand so much in spite of expansion, the fitting insertion portion 48b of the first bearing 48 creep-deforms in a direction in which the internal stress is reduced. As a result, the first bearing 48 is used during a long period of use. However, the shut-off valve of this embodiment has a small diameter of the fitting insertion portion 48b of the first bearing 48, so that the amount of expansion due to heat is small, and as a result, it is tightened by thermal stress. Stress is difficult to relax.
[0047]
Even if a relatively strong tightening margin is set, since the diameter of the insertion portion 48b is thin, it is difficult to wave and the coaxial with the partition wall is difficult. Further, the partition wall 47 is formed in a pan shape having a two-step bottom, and the first bearing 48 is fitted and inserted into the small-diameter pan side surface. The large-diameter pan side surface 47c into which the rotor 46 enters is formed. Has no effect, the axial tightening length of the first bearing 48, that is, the length of the fitting portion 48b can be sufficiently secured. Further, since the large-diameter pan side surface 47c of the partition wall 47 is not deformed or the fitting insertion portion 48b of the first bearing 48 is not easily worn during assembly, it is difficult to loosen and be deformed, and sufficient fitting can be realized. Thus, it is possible to set an insertion portion that is not easily affected by thermal stress, and a highly reliable shut-off valve can be realized.
[0048]
Further, when the shut-off valve is subjected to high-temperature thermal stress, the first bearing 48 or the second bearing 49 tends to expand outward, but the partition wall 47 does not expand so much so that the stress in the direction of expanding inward Become. Similarly, the stress when the first bearing 48 or the second bearing 49 is inserted into the partition wall 47 is also a stress in the direction of expanding inward. At this time, if the first bearing or the second bearing has a shape of a simple cylindrical bushing, the center hole may be deformed in a contracting direction and the rotating shaft 53 may be locked.
[0049]
However, the shut-off valve of the present embodiment has a rippled stress relaxation portion 48c formed between the fitting insertion portion 48b and the center hole 48a of the first bearing 48, and the second bearing. Since a thin ripple-shaped stress relaxation part 49d is formed between the 49 insertion part 49e and the center hole 49a, the stress to be expanded inside the insertion parts 48b and 49e is the stress relaxation part 48c. 49d is converted into stress in a direction in which the thin portion is bent, and the inner central holes 48a and 49a are less affected.
[0050]
For this reason, even if the tightening allowance with the partition wall 47 is set large, the diameters of the center holes 48a and 49a are difficult to be reduced and sufficient fitting can be realized, and the diameter is not easily reduced due to thermal stress. A highly reliable shut-off valve that is difficult to lock can be realized.
[0051]
Further, the outer side of the partition wall 47, that is, the stator 46 side becomes the air side when attached to the gas meter, and when the gas meter is installed outdoors, it is exposed to a high humidity environment. If the corrosion resistance of the material of the partition wall is poor or the corrosion potential of the electromagnetic yokes 44 and 45 is greatly different when used in a high humidity environment for a long time, a corrosion battery is formed and the hole is formed in the partition wall due to corrosion. Although the airtightness is destroyed and there is a risk of gas leakage, the shut-off valve of the present embodiment is an austenitic stainless steel plate in which the partition wall 47 is drawn. A highly reliable shut-off valve can be realized without causing hermeticity damage due to corrosion.
[0052]
In FIG. 1, the set of the exciting coil 43, the first electromagnetic yoke 44, and the second electromagnetic yoke 45 is two sets, but may be three sets or more. Further, the stator 46 and the partition wall 47 are fitted to the mounting plate 57 by the support frame 59, but they may be fixed to each other by welding without the support frame. Further, the rib 50 is provided in the second bearing 49 and the concave portion 61e is provided in the moving body 61. However, the groove is provided in the second bearing, and the convex portion is provided in the moving body to be engaged with the rotation preventing means. Alternatively, a rotation offset means may be provided by projecting a bar offset from the center on the mounting plate or the second bearing, and forming a hole or groove in the movable body to engage with it.
[0053]
The thrust bearings 67 and 68, which are sliding bearings, are used as the thrust bearings, but may be rolling bearings such as ball bearings. However, in the case of a shut-off valve of a microcomputer meter, the use of lubricating oil is not preferable because it is often left in a stationary state for a long period of time. Further, the linear motion mechanism is a screw mechanism of the feed screw 52 and the engaging portion of the moving body 61, but it may be a cylindrical cam mechanism, and the feed screw 52 is formed on the rotating shaft 53. Then, it may be input to the linear motion mechanism.
[0054]
Further, although the valve body 62 and the moving body 61 are separate parts, they may be configured integrally. The valve seat 63 includes the valve seat holding member 64. However, the valve seat 63 may be fitted in the center, and a central axis is formed in the valve seat holding member so that the valve seat is airtightly penetrated and another fixing member is used. You may fasten.
[0055]
(Example 2)
FIG. 4 is a cross-sectional view of the shutoff valve in the opened state according to the second embodiment of the present invention.
[0056]
Inside the stator 46, there are two-stage bottoms, large and small cylindrical portions 72a and 72b, and a partition wall shaped like a pan without a through hole having a large diameter collar 72c at the open end of the large diameter cylindrical portion 72a. 72. A sleeve-shaped first synthetic resin bearing 73 is fitted into the inner surface of the small-diameter cylindrical portion 72 b of the partition wall 72. A lid-shaped second bearing 74 made of synthetic resin is fitted into the open end of the large-diameter cylindrical portion 72 a of the partition wall 72. The second bearing 74 is provided with a pin 75 offset from the central axis. Inside the partition wall 72, a rotor 76 is disposed with a feed screw 77 protruding from the second bearing 74.
[0057]
A mounting plate 78 having substantially the same shape as the collar 72c is disposed between the collar 72c of the partition wall 72 and the stator 46, and a sealing member 79 such as a synthetic rubber O-ring is sandwiched between the fluid chamber 56 and the collar 72c. In this state, the mounting plate 78 and the partition wall 72 are fastened to the fluid chamber 56 with screws or the like. The outer periphery of the second bearing 72 is also sandwiched between the collar 72 c and the fluid chamber 56 at the same time. The mounting plate 78, the stator 46, and the electromagnetic yokes of the stator 46 are fixed to each other by welding.
[0058]
The valve body 80 includes a valve seat 81 and a valve seat holding member 82, and the convex portion of the valve seat holding member 82 is inserted into the concave portion of the valve body 80. On the rotor 46 side of the valve seat holding member 82, a female screw 82 a that can be screwed with the feed screw 77 and a guide groove 82 b that can be engaged with the pin 75 are formed.
[0059]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description. Further, the details of each part are the same as those in the first embodiment, and the description thereof will be omitted.
[0060]
Since the operation of this shut-off valve is substantially the same as that of the first embodiment, detailed description thereof is omitted. Unlike the first embodiment, this shut-off valve is configured such that the valve body 80 and the moving body (female screw 82a) are integrally formed and there is no coil spring. Therefore, in the shut-off operation, the rotor 76 rotates and the valve body 80 It is completed by moving and contacting the valve seat 65, the valve seat 81 being bent, and the rotation of the rotor 76 being stopped. Since this shut-off valve relies on the elastic force of the valve seat 81 to close the valve body when the valve is closed, the valve closing stability is higher than that in the first embodiment in which a stable urging force is provided by the coil spring 66. Although slightly inferior, there is an economic effect because the number of parts can be reduced.
[0061]
Next, the operation of the shutoff valve described in the second embodiment will be described. In this shut-off valve, since the axial length of the small-diameter cylindrical portion 72b of the partition wall 72 is long, it is possible to set a fitting insertion portion that is not easily affected by thermal stress even with a relatively loose fitting. The first bearing 73 can also be set. And since the loose fitting may be sufficient, the center hole diameter of the 1st bearing 73 is hard to reduce.
[0062]
Since the second bearing 74 and the collar 72c of the partition wall 72 are both sandwiched and fixed between the mounting plate 78 and the fluid chamber 56, the second bearing 74 and the large-diameter cylindrical portion 72a of the partition wall 72 are fitted together. The center hole diameter of the second bearing 74 is difficult to reduce. Further, only the seal member 79 provided between the flange 72c of the partition wall 72 and the fluid chamber 56 serves as a gas seal portion, and since there are few seal locations, a highly reliable airtight structure is provided.
[0063]
As described above, the shutoff valve of the second embodiment can realize a highly reliable bearing and airtight shutoff valve with a simple structure having a small number of parts.
[0064]
Note that the pin 75 as the rotation preventing means may be formed integrally with the second bearing 72.
[0065]
【The invention's effect】
As described above, according to the present invention, the partition wall is formed into a pan shape having a two-step bottom, and the first bearing made of synthetic resin is inserted into the small-diameter pan side surface of the partition wall so as to form a generally lid-shaped synthetic resin. Since the second bearing made of this is fitted to the open end side of the large-diameter pan side surface of the partition wall, the tightening stress is difficult to relieve because the diameter of the insertion and fitting portion of the first bearing is thin. Even if a strong tightening allowance is set, it is difficult to corrugate with the bulkhead because it is difficult to wobble, and it is possible to secure a sufficient axial tightening length, and it is difficult to deform the bulkhead and wear the interference fit during assembly. It has an advantageous effect that it is difficult to loosen and deform, and a sufficient fitting can be realized and a highly reliable shut-off valve can be realized.
[0066]
In addition, since the stress relaxation portion is formed between the insertion portion to the partition wall and the central hole in the first or second bearing, the tightening stress of the insertion interference fit portion is reduced by the stress relaxation portion. Since it is difficult to transmit to the center hole of the bearing No. 2, the bearing hole diameter is difficult to be reduced even if the tightening margin with the partition wall is set large, and it is possible to realize sufficient fitting and to realize a highly reliable shut-off valve. Has an effect.
[0067]
In addition, by making the partition wall a drawn austenitic stainless steel plate, the partition wall is hard to corrode and has a strong strength, and it is difficult to cause hermetic breakdown due to corrosion with steel that is an electromagnetic yoke member of the stator, It has an advantageous effect that a highly reliable shut-off valve can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a shut-off valve in an opened state according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the shut-off valve during a shut-off operation. 4] Cross-sectional view of the shut-off valve according to the second embodiment of the present invention in the open state. [Fig. 5] Cross-sectional view of the shut-off valve of the conventional shut-off state.
43 Excitation coil 46 Stator 47, 72 Bulkhead 48, 73 First bearing 48a Center hole 48b Insertion part 48c Stress relaxation part 49, 74 Second bearing 55, 76 Rotor 53 Rotating shaft 61 Moving body (valve mechanism)
62, 80 Valve body (valve mechanism)

Claims

Formed by drawing into a stator having an excitation coil and a pan-like shape having a two-stage bottom formed of a large-diameter cylindrical portion and a small-diameter cylindrical portion without being provided with a through-hole coaxially disposed inside the stator. opening of the partition wall and a first bearing made of synthetic resin having a fitting interpolated that fitting portion to pan side of the small-diameter cylindrical portion of the center hole and the partition wall, pan side of the cylindrical portion of the large diameter of the partition wall A lid-shaped synthetic resin second bearing having a center hole fitted on the end side, a rotor disposed inside the partition so as to face the stator, and the first and second bearings A rotary shaft of the rotor that is loosely inserted into the rotary shaft, and a valve mechanism that protrudes outward from the second bearing and is disposed on the rotary shaft, and the first bearing has the large diameter. A stopper that abuts the bottom of the cylindrical portion, and the stopper is attached to the side surface of the large-diameter cylindrical portion of the partition wall; Shut-off valve, characterized in that it has a size not in contact it is.

First bearing or the second bearing, the shut-off valve of claim 1, wherein the formation of the stress absorbing portions between the inserting portion and the center hole of the partition wall.