JP4206164B2

JP4206164B2 - Vacuum gate valve

Info

Publication number: JP4206164B2
Application number: JP06393999A
Authority: JP
Inventors: 祥愼福田; 圭司加藤
Original assignee: Shinmaywa Industries Ltd
Current assignee: Shinmaywa Industries Ltd
Priority date: 1999-03-10
Filing date: 1999-03-10
Publication date: 2009-01-07
Anticipated expiration: 2019-03-10
Also published as: JP2000257727A

Description

【０００１】
【発明の属する技術分野】
本発明は、真空容器に連通する開口を開閉する弁板を有する真空ゲート弁に関し、特に、弁板のシール性を安定して確保するための技術分野に属する。
【０００２】
【従来の技術】
従来より、この種の真空ゲート弁として種々のものが知られている。例えば実開昭６２―１９９５６７号公報に示されるものでは、真空容器に連通する開口を有する弁箱内に弁板支持体を、その背面に軸支したガイドローラで案内しながら昇降可能に配置し、この弁板支持体の前側に、弁箱の開口を開閉する弁板を平行リンク機構を介して接離可能に支持し、弁板支持体の閉弁位置への移動時に弁板に当接して弁板を弁板支持体から離れる閉じ方向に相対移動させるストッパを設け、弁箱外に、弁箱の壁部を気密状に貫通するピストンロッドを有するシリンダを取り付けて、そのピストンロッドの先端部を弁箱内の弁板支持体に連結し、シリンダの伸縮作動により弁板支持体を弁箱内で移動させて弁板を開閉させ、シリンダにより弁板支持体を開弁位置に移動させたときには、その弁板支持体と共に弁板を移動させて弁箱の開口を開く一方、弁板支持体を閉弁位置に移動させたときには、その途中で、弁板をストッパに当接させて平行リンク機構により弁板支持体から離隔させ、平行リンク機構のリンクを弁板支持体と弁板との間で突張り状態にして弁板を弁箱の開口周りに押し付け、このことで開口を弁板によりシールして閉じるようになされている。
【０００３】
また、この他、実開昭５９―１５２２５２号や実開平４―１０６５８３号の各公報に示されるように、弁板をシリンダのピストンロッド先端部に直接に取り付けて弁箱の開口に沿った平面と略平行に移動させるようにし、この閉じ位置にある弁板の後側に、環状の弁板押さえと、この弁板押さえに連結された２重円筒状のベローズとを配設し、このベローズに対する圧力流体の給排により、閉じ位置にある弁板を弁箱の壁内面に接離させて開口を開閉するようにしたものが知られている。
【０００４】
【発明が解決しようとする課題】
ところで、上記前者の従来例（実開昭６２―１９９５６７号公報）のように、弁板支持体に平行リンク機構等の連結手段を介して弁板を接離可能に支持し、その弁板を閉じ位置で弁板支持体から離隔させて弁箱の開口周りに押し付け、その弁板で開口を閉じるようにした場合、ゲート弁が長期間に亘り使用されてその開閉回数が多くなると、それに応じて上記連結手段の部品が摩耗し、或いは弁板と弁箱の開口周りとの間を気密シールしているシール部材がへたったり摩耗したりし、この連結手段やシール部材の摩耗等によりシール構造のガタが生じて、ゲート弁の真空シール性能や耐圧性能が低下するという問題があった。このため、連結手段やシール部材のメンテナンスを短期間で行う必要があり、改良の余地がある。
【０００５】
本発明は斯かる点に鑑みてなされたもので、その目的は、上記真空ゲート弁の連結手段やシール部材の摩耗等によるシール構造のガタを吸収する手段を講じることにより、そのゲート弁の真空シール性能や耐圧性能の低下を抑制し、連結手段やシール部材のメンテナンスのサイクルを延ばし得るようにすることにある。
【０００６】
【課題を解決するための手段】
上記の目的の達成のため、この発明では、真空ゲート弁の閉弁時には、弁板が弁板支持体から離隔して開口の周囲部に押し付けられていることに着目し、その状態では弁板の支持部である弁板支持体を弁箱等の固定体に対し弾性状態で支持し、この弾性支持によってシール構造のガタを吸収するようにした。
【０００７】
具体的には、請求項１の発明では、真空容器に連通する開口に沿った平面と略平行に移動可能な弁板支持体と、該弁板支持体に連結手段を介して支持され、弁板支持体の移動に伴い弁板支持体に対し接離して開口を開閉する弁板と、この弁板及び上記開口の周囲部の間をシールするシール部材とが設けられてなる真空ゲート弁が前提である。
【０００８】
そして、上記弁板支持体又は弁板の閉じ状態で該弁板支持体に対向する固定体の少なくとも一方に、上記シール部材とは別に突設され、かつそのシール部材のばね定数以下のばね定数を有し、上記弁板支持体又は固定体の他方に対し弁板の開閉方向に押し付けられて、上記弁板が開口を閉じた状態で上記弁板支持体を弁板の閉じ方向に付勢する、シール機能のない弾性部材を備えたことを特徴とする。
【０００９】
上記の構成により、ゲート弁の閉弁時に、弁板支持体から離隔した弁板が開口の周囲部に押し付けられて開口が閉じられると、この弁板の閉じ状態では、シール機能のない弾性部材が弁板支持体を固定体から離れるように押して、この弾性部材により上記弁板支持体が弁板の閉じ方向（弁板が開口の周囲部に押し付けられる方向）に付勢される。従って、ゲート弁の長期使用に伴って連結手段やシール部材の摩耗等によりシール構造のガタが生じても、そのガタは上記弾性部材による弁板支持体の付勢力により吸収され、ガタの分を補償するように弁板が開口周囲部に常に略一定の圧力で押し付けられるようになる。このことで、ゲート弁の真空シール性能や耐圧性能の低下を長期間に亘り抑制して、連結手段やシール部材のメンテナンスのサイクルを延ばすことができる。
【００１０】
また、上記弾性部材のばね定数が、弁板と開口の周囲部との間をシールするシール部材のばね定数以下であるので、以下の作用効果が得られる。つまり、弾性部材のばね定数が低いほどシール構造のガタを安定して抑制できるが、その反面では弁板を閉じ位置で開口の周囲部へ押し付けるのに必要なストロークが大きくなる。そして、この押付けストロークを短くするには、弾性部材のばね定数を高くする必要があるが、シール部材のばね定数よりも大きくすると、シール構造のガタを抑制するのが困難となる。従って、弾性部材のばね定数をシール部材のばね定数以下とすることで、弁板の押付けストロークを適正に保ちつつ、弾性部材によるシール構造のガタ抑制効果が有効に得られる。
【００１１】
請求項２の発明では、弾性部材はゴム材又は樹脂材からなるものとする。こうすれば、望ましい機能を有する弾性部材が具体的に容易に得られる。
【００１２】
【発明の実施の形態】
図６及び図７は本発明の実施形態に係る真空ゲート弁Ｇを示す。この真空ゲート弁Ｇは、図１及び図２に示すように、前後に位置する第１及び第２真空容器Ｃ１，Ｃ２間に両真空容器Ｃ１，Ｃ２の内部空間（真空空間）同士を連通又は連通遮断するように配設される。
【００１３】
上記真空ゲート弁Ｇは、両真空容器Ｃ１，Ｃ２間に気密状に挟まれた矩形状の弁箱１（固定体）を備え、この弁箱１の前壁（図１、図２及び図６で左側壁）の上部には第１真空容器Ｃ１に連通する前側開口２が、また後壁（同右側壁）の上部には第２真空容器Ｃ２に連通する後側開口３がそれぞれ同じ高さ位置に形成され、これらの開口２，３はいずれも左右方向（図６の紙面と直交する方向。図７では左右方向）に長い矩形状でかつ同じ大きさとされており、この各開口２，３を介して弁箱１内の空間が各真空容器Ｃ１，Ｃ２内部と連通している。
【００１４】
図１及び図２に拡大して示すように、上記弁箱１内には、上記前側開口２を開閉する弁板５が配置されている。この弁板５は前側開口２よりも若干大きい左右方向に長い矩形状の板材からなり、その前面外周部には弁板５の全体に亘って連続するシール収容溝６が形成され、このシール収容溝６内には、弁箱１の前壁内面に圧接変形して弁板５と弁箱１の前側開口２周囲の前壁内面との間をシールするゴム製のシール部材７が収容固定されている。
【００１５】
上記弁板５は、その長さ方向である左右方向に離れた左右両側の２箇所（３箇所以上でもよい）で後面側から同期して弁板支持体１０により後述の平行リンク機構２２，２２を介して押圧されて前側開口２を閉じるものとされている。すなわち、弁板５の後側の弁箱１内に上記弁板支持体１０が配置され、この弁板支持体１０は、弁板５と共に、弁箱１内の下側に位置する開弁位置と、弁箱１内の上側でかつ前後の開口２，３に対応する閉弁位置との間を上記前側開口２に沿った鉛直平面と略平行に上下移動可能とされている。弁板支持体１０は、弁箱１の後側開口３よりも大きい矩形板状の本体１１を有し、この本体１１の前面には、上記弁板５の左右の押圧位置に対応する部分にそれぞれ各平行リンク機構２２の各ガイドローラ３１，３２を案内するためのガイド部材１２が円環板状の取付部材２０により一体的に取付固定されている。すなわち、上記ガイド部材１２は、図３〜図５に示すように、後向きに開口する浅い略皿形状のもので、その下側壁部が切り欠かれて開放され、この切欠き部分以外の外周上半部の後端には半径方向外側に延びるフランジ１２ａが形成されており、このフランジ１２ａを取付部材２０の内周部に係止した状態で該取付部材２０をボルト２１，２１，…（１つのみ図示する）により本体１１に取り付けることで、各ガイド部材１２が本体１１の前面に取付部材２０を介して取付固定されている。
【００１６】
また、上記弁板支持体１０における取付部材２０の下縁部には円筒状の第１ロッド３６の上端部（内端部）が移動一体に気密状に溶接固定されており、この第１ロッド３６の昇降移動（長さ方向の移動）により弁板支持体１０が開弁位置と閉弁位置との間を移動する。
【００１７】
上記ガイド部材１２の前壁（底壁）の中心部には縦長矩形状の開口１４が貫通形成されている。また、ガイド部材１２の前面には、上記開口１４の上下縁部からそれぞれ水平前側に平行に延びる上下１対の突出片１５，１６が一体に形成され、この上側突出片１５下面は開口１４の上縁部下面と、また下側突出片１６上面は開口１４の下縁部上面とそれぞれ面一とされている。また、上記弁板支持体１０の本体１１前面には、上記各ガイド部材１２の開口１４に対応して所定深さの矩形凹部１１ａが形成されている。そして、上記ガイド部材１２の前壁（底壁）と本体１１前面の凹部１１ａとにより、後述する第２ロッド３７の移動方向（上下方向）に延びる垂直ガイド部１３が、また上下１対の突出片１５，１６ないし開口１４により、弁板５の移動方向（前後方向）に延びる水平ガイド部１７がそれぞれ形成されている。また、図５に示すように、上記垂直ガイド部１３を形成するガイド部材１２の前壁後面において開口１４の下側部と、水平ガイド部１７において下側突出片１６の上面後端部との交差部には、後述の下側リンク２８との干渉を避けるために斜めに切り欠いてなる面取部１８が形成されている。
【００１８】
上記弁板支持体１０の左右の各ガイド部材１２内には、上記弁板５を弁板支持体１０に対し前後方向に接離可能に支持するための連結手段としての平行リンク機構２２が配置されている。すなわち、上記各ガイド部材１２における上下の突出片１５，１６間には水平左右方向に延びる上下の前リンク軸２３，２３が上下方向に所定間隔をあけて配置され、この各前リンク軸２３は、左右端部の前側切欠部２３ａ，２３ａ（図３参照）にて弁板取付部材２５にボルト２４，２４により締結固定され、この弁板取付部材２５は弁板５の後面にボルト２６，２６，…により締結されている。
【００１９】
一方、上記各垂直ガイド部１３内、つまりガイド部材１２の開口１４の左右両側部分の前壁後面と本体１１前面の各矩形凹部１１ａ底面（前面）との間には、水平左右方向に延びる上下の後リンク軸２７，２７が上記前リンク軸２３，２３と同じ間隔をあけて上下方向に配置されている。そして、図３に示すように、上記各前リンク軸２３の左右両側寄りに位置する部分にはそれぞれ樹脂製等の左右リンク２８，２８の前端部が揺動可能に支持され、このリンク２８，２８の後端部は、それぞれ前リンク軸２３の後側に対応して位置する後リンク軸２７の左右両側寄り部分に揺動可能に支持されており、前後のリンク軸２３，２７同士は左右１対のリンク２８，２８により連結されている。この各リンク２８の中間部にはその下面を切り欠いた形状の凹部２９が形成されており、図２に示す如く、各リンク２８が後側部を下げるように後向きに傾斜したときに、その凹部２９によりガイド部材１２の開口１４の下縁部上面後端と干渉しないようにしている。
【００２０】
さらに、上記上下の後リンク軸２７，２７は、その左右中央部にて、それぞれガイド部材１２内を上下方向に延びる第２ロッド３７の上端部に上記間隔をあけて取付固定されている。この上下の後リンク軸２７，２７の第２ロッド３７との連結構造はいずれも同じで、各後リンク軸２７の左右中央部にはその略前半部を平面状に切り欠いた嵌合部２７ａが、また第２ロッド３７にはその略後半部を平面状に切り欠いてなる嵌合部３７ａがそれぞれ形成されており、後リンク軸２７と第２ロッド３７とは、互いに交差しかつ各々の嵌合部２７ａ，３７ａで嵌合した状態で両者を前後方向に貫通するボルト３８により一体的に締結固定されている。よって、上記前後のリンク軸２３，２３，２７，２７及び上下両側のリンク２８，２８，…により平行リンク機構２２が構成されている。
【００２１】
上記各前リンク軸２３の左右中央部には、上記水平ガイド部１７により水平前後方向に案内される樹脂製等の前ガイドローラ３１が回転可能に支持されている。すなわち、上側に位置する前リンク軸２３上の前ガイドローラ３１は、ガイド部材１２の上側突出片１５下面ないし開口１４の上縁部下面に沿って、また下側に位置する前リンク軸２３上の前ガイドローラ３１は、下側突出片１６の上面ないし開口１４の下縁部上面に沿ってそれぞれ前後方向に移動可能に転動案内されるようになっており、これら上下の前ガイドローラ３１，３１の案内により弁板５がガイド部材１２（弁板支持体１０）に対し上下方向に相対移動不能に位置決めされた状態で前後移動する。
【００２２】
また、上記各後リンク軸２７の左右端部にはそれぞれ上記垂直ガイド部１３により垂直上下方向に案内される樹脂製等の後ガイドローラ３２，３２が回転可能に支持されている。つまり、これら後ガイドローラ３２，３２は、ガイド部材１２の開口１４の左右両側の前壁後面と本体１１前面の各凹部１１ａ底面との間を転動して案内される。
【００２３】
そして、上記弁板支持体１０が弁箱１内上側の閉弁位置にあるときに、その内部で第２ロッド３７のみを昇降移動させることで、平行リンク機構２２により弁板５を弁板支持体１０に対し接離するように前後方向（両真空容器Ｃ１，Ｃ２の配列方向）に移動させて弁箱１の前側開口２を開閉し、図２に示すように、第２ロッド３７を下降させたときには、平行リンク機構２２の各リンク２８を後側に向かって下側に向かうように傾斜させ、弁板５を弁板支持体１０（第２ロッド３７）に接近させて弁箱１の前側開口２周りの前壁から離隔させることで、その開口２を開く一方、図１に示すように、第２ロッド３７を上昇させたときには、平行リンク機構２２の各リンク２８を前後方向に水平に配置し、弁板５を弁板支持体１０から離して前側開口２周りの前壁内面に押し付けることで、その開口２を閉じるようになっている。
【００２４】
上記弁板支持体１０における各取付部材２０の前端部とその前側の各弁板取付部材２５との後面との間に亘り金属製円筒状の機構収容ベローズ３４が両者の接離方向に伸縮可能に設けられている。この機構収容ベローズ３４の前後端部はそれぞれ弁板取付部材２５及び取付部材２０に気密状に溶接されており、この機構収容ベローズ３４、弁板５（弁板取付部材２５）及び弁板支持体１０で囲まれる気密状の空間に平行リンク機構２２が収容されている。すなわち、機構収容ベローズ３４は、平行リンク機構２２から発生する塵を密閉空間内に封じ込めて弁箱１内への放出を防止するものである。
【００２５】
上記弁板支持体１０が弁箱１内で開弁位置及び閉弁位置間を昇降する動きと、この弁板支持体１０に対し弁板５が接離する動きとは、いずれも弁箱１の底壁外側からの駆動により行われるようになっている。つまり、弁箱１の底壁において各平行リンク機構２２の真下の部分（上記弁板５の左右の押圧位置に対応する部分）には開口部１ａ，１ａが形成され、この各開口部１ａ下面には、上下方向に延びかつ上端が開口する有底状の筒部４０の上端部が同心状にかつ気密状に接合され、この筒部４０の底部中心には中心孔４０ａが貫通形成されている。さらに、上記筒部４０の下側には円筒状のストッパ４１が同心状に接続固定されている。
【００２６】
そして、上記第１ロッド３６は上記弁箱１底壁の開口部１ａないし筒部４０に挿通され、この第１ロッド３６の下端部（外端部）は、筒部４０底部の中心孔４０ａを気密状に貫通した後に弁箱１外であるストッパ４１内を下側に延びてその下側に突出し、この下端部には円板状の上側プレート４２が移動一体に取付固定されており、第１ロッド３６の昇降移動（長さ方向の移動）により弁板支持体１０を開弁位置及び閉弁位置間で移動させ、後述のベローズ取付フランジ５４が略弁箱１の底壁の位置に移動したときを弁板支持体１０の開弁位置に、また上側プレート４２がストッパ４１の下面に当接したときを閉弁位置にそれぞれ設定している。
【００２７】
一方、上記弁板５を弁板支持体１０に対し接離させて開閉させるための上記第２ロッド３７は上記筒状の第１ロッド３６内に上下方向に摺動可能に挿通されている。この第２ロッド３７は、上記弁板支持体１０における取付部材２０の下端部に第１ロッド３６と同心状に形成した挿通孔２０ａに挿通され、その上端部は、既述の如く弁板支持体１０のガイド部材１２内に位置して平行リンク機構２２の後リンク軸２７，２７に移動一体に連結されている。第２ロッド３７の下端部（外端部）は第１ロッド３６の下端部から突出して弁箱１外に延び、この下端部には上側プレート４２と略同径の円板状の下側プレート４３が移動一体に取付固定されており、第２ロッド３７が第１ロッド３６に対し相対的に摺動して長さ方向に移動することにより、弁板５の開き状態及び閉じ状態を切り換え、下側プレート４３が上側プレート４２から最も離れて後述のリンク機構４６，４６が伸長したときを弁板５が弁板支持体１０に接近した開き状態に、また下側プレート４３が上側プレート４２に最も接近して同リンク機構４６，４６が収縮したときを弁板５が弁板支持体１０に離隔した閉じ状態にそれぞれなるようにしている。
【００２８】
図７に示すように、上記左右の第２ロッド３７，３７下端の下側プレート４３，４３には駆動手段としての１つのエアシリンダ５７が駆動連結されている。すなわち、このエアシリンダ５７は上記弁板５の左右の押圧位置間の中央下方位置に配置された上下方向のシリンダ軸線を有するもので、そのボディ上端部は弁箱１に相対移動不能に固定されている。シリンダ５７のピストンロッド５７ａの上端（先端）にはブラケット５８の左右中央部が連結されている。このブラケット５８は左右中央部よりも左右端部が低くなるように略コ字状に折れ曲がった部材からなるもので、その左右端部にそれぞれ上記左右の下側プレート４３，４３が連結されており、１つのシリンダ５７の伸縮作動により、そのピストンロッド５７ａの上端部にブラケット５８を介して連結された左右の第２ロッド３７，３７を長さ方向に昇降移動させて、その第１ロッド３６，３６との一体移動による弁板支持体１０の開弁位置及び閉弁位置間の昇降移動と、第２ロッド３７，３７のみの移動による弁板５の開き状態及び閉じ状態間の切換えとを行うようにしている。
【００２９】
上記弁箱１の外側にある上側及び下側プレート４２，４３間には、第２ロッド３７の下端部周りに配置した圧縮ばね４４が縮装されており、この圧縮ばね４４により第２ロッド３７を第１ロッド３６に対し、弁板５が弁板支持体１０に接近して弁箱１の前側開口２を開く下方向に相対移動させるように付勢している。
【００３０】
さらに、図６に示すように、上記上側及び下側プレート４２，４３同士は、直径方向に対向した位置に配置した１対のリンク機構４６，４６により連結されている。この各リンク機構４６は、上端部が上側プレート４２に水平方向の軸心をもって揺動可能に軸支された上リンク４７と、上端部が該上リンク４７の下端部に水平方向の連結軸４９を介して揺動可能に連結され、下端部が下側プレート４３に水平方向の軸心をもって揺動可能に軸支された下リンク４８とからなり、上記連結軸４９にはガイドローラ５０が回転可能に支持されている。そして、この各リンク機構４６を上下のリンク４７，４８が上下方向に略一直線上に並ぶように伸長させたときには、下側プレート４３を上側プレート４２から離して弁板５を弁板支持体１０に接近させる一方、リンク機構４６を上下のリンク４７，４８が外側（連結軸４９が第２ロッド３７から離れる側）に折れ曲がるように収縮させたときには、下側プレート４３を上側プレート４２に接近させて弁板５を弁板支持体１０から離隔させるようにしている。
【００３１】
また、上記各ストッパ４１の真下位置には、シリンダ５７のストロークに対応した所定長さのリンク規制部５２，５２が配置固定されている。この両リンク規制部５２，５２は、その間を上記上側及び下側プレート４２，４３が所定の隙間をあけて昇降移動するように前後に対向配置されたもので、両リンク規制部５２，５２間には側方から上記ブラケット５８の左右端部が昇降移動可能に挿通されており、シリンダ５７の伸縮作動による各下側プレート４３の昇降動作に応じて各リンク機構４６を伸長状態又は収縮状態に切り換え、シリンダ５７の伸縮作動に伴って弁板支持体１０を開弁位置及び閉弁位置間で昇降移動させたとき、その弁板支持体１０が上昇端の閉弁位置以外にある状態では、上記各リンク機構４６をリンク規制部５２内（両リンク規制部５２，５２間）に、上下リンク４７，４８間の連結軸４９上のガイドローラ５０が各リンク規制部５２の内面で転動案内されるように潜らせて伸長状態に保持する一方、弁板支持体１０が上昇端の閉弁位置にある状態では、各リンク機構４６をリンク規制部５２上端から突出させて収縮状態に切り換えるようにしている。尚、各リンク規制部５２の上端面は、上記ガイドローラ５０の昇降時のリンク規制部５２内に対する出没をスムーズに行わせるように上側に向かって外側（相手側リンク規制部４２から離れる側）に傾斜する傾斜面に形成されている。
【００３２】
そして、上記弁箱１内の下部にある第１ロッド３６の上端寄り部分にはベローズ取付フランジ５４が気密状に一体に取付固定されている。このベローズ取付フランジ５４の下面には、第１ロッド３６の周りに配置した金属製の伸縮可能なロッド収容ベローズ５５の上端部が気密状に溶接固定され、このロッド収容ベローズ５５の下端部は、弁箱１の底壁における筒部４０の底部上面に気密状に溶接固定されており、ロッド収容ベローズ５５により第１ロッド３６の貫通部を気密状に覆っている。
【００３３】
さらに、上記弁板支持体１０の本体１１後面には、上記左右の平行リンク機構２２の各々の上下両側位置にそれぞれ左右方向に延びる上下の弾性部材取付溝６０，６０が形成され、この各取付溝６０には取付溝６０と略同じ長さの丸棒状のゴム（樹脂製でもよい）からなる弾性部材６１が一部を本体１１後面から突出させた状態で収容され、この各弾性部材６１は取付溝６０内部に、ねじ止めした保持部材６２により取付保持されている。上記各弾性部材６１は、弁板５が弁箱１の前側開口２を閉じた閉じ状態で、弁箱１において弁板支持体１０に対向する後側開口３周囲の後壁内面（前面）に押し付けられるもので、この押付け状態での弾性部材６１の弾性反力により弁板支持体１０が弁板５の閉じ方向たる前方向に付勢されるようになっており、その弾性部材６１のばね定数は、上記弁板５前面周囲のシール部材７のばね定数以下とされている。
【００３４】
次に、上記実施形態の作動について説明する。真空ゲート弁Ｇが開弁しているときには、シリンダ５７は収縮してストロークエンドにある。このため、上側及び下側プレート４２，４３は両者を連結するリンク機構４６，４６と共にリンク規制部５２，５２間にあり、その各リンク機構４６は伸長して両プレート４２，４３が離隔している。このことで弁板支持体１０は開弁位置にあり、また、第２ロッド３７の上端部は弁板支持体１０内の下側に位置していて、各平行リンク機構２２の各リンク２８が後側に向かって下側に向かうように傾斜し（図２参照）、弁板５が弁板支持体１０に接近した位置にあって弁箱１の前壁内面から離隔している。また、機構収容ベローズ３４及びロッド収容ベローズ５５はいずれも収縮している。
【００３５】
この状態からゲート弁Ｇを閉弁させるときには、シリンダ５７が伸長してピストンロッド５７ａが上昇する。このピストンロッド５７ａの上昇移動に伴い、その上端にブラケット５８を介して連結されている各下側プレート４３と、該各下側プレート４３に下端が連結されている第２ロッド３７とが上昇する。このとき、上記下側プレート４３と上側プレート４２とを連結しているリンク機構４６，４６はそれぞれリンク規制部５２，５２によりその間に伸長状態に拘束されており、しかも両プレート４２，４３間には圧縮ばね４４が介在されているので、上記下側プレート４３の上昇移動に伴って上側プレート４２も下側プレート４３から離隔したままで追従して上昇し、両者の相対移動は生じない。このことで、ロッド収容ベローズ５５が伸長しながら、上側プレート４２と共に第１ロッド３６が上昇して、その第１ロッド３６の上端部に連結されている弁板支持体１０が開弁位置から閉弁位置に向かって弁板５と共に上昇する。また、第１及び第２ロッド３６，３７間の相対移動が生じないので、弁板５が閉じ状態に切り換わることはなく、その弁板５は弁板支持体１０に接近したままに保たれ、その上昇時に弁箱１の前壁の内面に接触しない。
【００３６】
シリンダ５７がさらに伸長して伸長ストロークエンド近くに達すると、上側プレート４２が、弁箱１の底壁下面の筒部４０に接合されているストッパ４１の下面に当接してそれ以上の上昇移動が規制される。このことで、図２に示すように、弁板支持体１０が閉弁位置に停止して、弁板５が弁箱１における前側開口２に対応した位置に位置付けられる。この状態では、上記各リンク機構４６がリンク規制部５２の上端から抜け出し始めており、シリンダ５７のさらなる伸長作動により、上記各リンク機構４６が収縮状態に変化しかつ圧縮ばね４４が圧縮されながら、上記ストッパ４１で停止規制されている上側プレート４２に対し下側プレート４３のみが上昇する。このことで、図１に示すように、第１ロッド３６と共に停止保持されている弁板支持体１０に対し、第２ロッド３７のみが相対的に上昇して、この第２ロッド３７のみの上昇移動により、機構収容ベローズ３４を伸長させながら、各平行リンク機構２２の各リンク２８が前後方向に水平に回動し、弁板５が弁板支持体１０から離れるように前側に移動して弁箱１の前側開口２周囲の前壁内面を押圧し、その開口２がシール部材７により気密状に閉塞されてゲート弁Ｇが閉弁する。
【００３７】
一方、上記のような閉弁状態にあるゲート弁Ｇを開弁させるときには、上記シリンダ５７が収縮してピストンロッド５７ａが下降する。このピストンロッド５７ａの下降移動に伴い、各下側プレート４３が第２ロッド３７と共に下降し、この第２ロッド３７の下降移動により、機構収容ベローズ３４を収縮させながら、各平行リンク機構２２の各リンク２８が傾斜方向に回動し、弁板５が弁板支持体１０に近付く後方向に移動して弁箱１の前側開口２周囲の前壁内面から離れ、その開口２が開かれる。この後、リンク規制部５２によるリンク機構４６の伸長規制により第１及び第２ロッド３６，３７が一体的に下降して弁板支持体１０が弁板５と共に開弁位置に移動し、ゲート弁Ｇが開弁する。
【００３８】
そして、この実施形態においては、上記弁板支持体１０の本体１１後面で上記左右の平行リンク機構２２，２２の各々の上下両側位置の弾性部材取付溝６０，６０にそれぞれ弾性部材６１，６１が一部を本体１１後面から突出させた状態で充填されているので、上記ゲート弁Ｇの閉弁時、弁板支持体１０から離隔した弁板５が弁箱１の前側開口２周囲の前壁内面に押し付けられて開口２が閉じられたとき、上記各弾性部材６１が弁箱１の後側開口３周囲の後壁内面（前面）に押し付けられて圧縮変形し、この圧縮変形状態にある弾性部材６１の弾性反力により弁板支持体１０が弁箱１に対し弁板５の閉じ方向たる前方向に付勢される。こうして閉弁時に弁板支持体１０を弁板５の閉じ方向に付勢することで、仮に、ゲート弁Ｇの長期使用に伴って各平行リンク機構２２やシール部材７の摩耗等により弁箱１の前側開口２に対する弁板５のシール構造にガタが生じたとしても、そのガタは上記弾性部材６１による弁板支持体１０の付勢力により吸収される。つまり、ガタが生じても、その分を補償するように弁板５が前側開口２周囲の前壁内面に常に略一定の圧力で押し付けられるようになる。その結果、ゲート弁Ｇの真空シール性能や耐圧性能の低下が長期間に亘り抑制され、その分、平行リンク機構２２やシール部材７についてのメンテナンスのサイクルを延ばすことができる。
【００３９】
また、上記各弾性部材６１は弁板支持体１０の本体１１後面において、左右の平行リンク機構２２，２２の各々の上下両側位置であって、閉じ状態の弁板５から反力を集中して受ける位置に配設されているので、上記シール構造のガタを確実に吸収して有効な効果が得られる。
【００４０】
さらに、上記弾性部材６１のばね定数は、弁板５と前側開口２周囲の前壁内面との間をシールするシール部材７のばね定数以下であるので、弁板５の押付けストロークを適正に保ちつつ、その弾性部材６１によるシール構造のガタ抑制効果が得られる。つまり、弾性部材６１のばね定数が低いほどシール構造のガタを安定して抑制できるが、その反面では弁板５を弁箱１の前壁内面へ押し付けるための前後方向のストロークが大きくなる。そして、この押付けストロークを短くするには、弾性部材６１のばね定数を高くする必要があるが、そのばね定数がシール部材７のばね定数よりも大きくなると、シール構造のガタを抑制するのが困難となる。従って、弾性部材６１のばね定数をシール部材７のばね定数以下とすることで、弁板５の押付けストロークの適正化と、弾性部材６１によるシール構造のガタ抑制効果との両立を図ることができる。
【００４１】
さらに、この実施形態では、上記各平行リンク機構２２の各前リンク軸２３の左右中央部には前ガイドローラ３１が、また後リンク軸２７の左右両側部には左右の後ガイドローラ３２，３２がそれぞれ支持され、第２ロッド３７のみの昇降移動に伴う弁板５の前後移動時、上側に位置する前リンク軸２３上の前ガイドローラ３１は、水平ガイド部１７においてガイド部材１２の上側突出片１５下面ないし開口１４の上縁部下面に沿って、また下側に位置する前リンク軸２３上の前ガイドローラ３１は、下側突出片１６の上面ないし開口１４の下縁部上面に沿ってそれぞれ前後方向に移動可能に転動案内される一方、各後ガイドローラ３２は垂直ガイド部１３、つまりガイド部材１２における開口１４の左右両側の前壁後面と本体１１前面の各矩形凹部１１ａ底面との間で転動して案内される。この水平ガイド部１７及び垂直ガイド部１３による各ガイドローラ３１，３２の案内により各リンク２８をスムーズに揺動させることができ、弁板５の弁板支持体１０に対する接離動作が滑らかに行われる。すなわち、弁板支持体１０に垂直ガイド部１３及び水平ガイド部１７が設けられて、これらガイド部１３，１７により平行リンク機構２２の各ガイドローラ３１，３２を転動案内するので、弁板支持体１０をコンパクトな構造としつつ、各平行リンク機構２２の動作のスムーズ化を図ることができる。
【００４２】
また、上記各平行リンク機構２２における各後リンク軸２７と第２ロッド３７とは、後リンク軸２７の前側が切り欠かれた嵌合部２７ａと第２ロッド３７の後側部が切り欠かれた嵌合部３７ａとを互いに交差した状態で嵌合して締結されているので、これら嵌合部２７ａ，３７ａの切欠き分だけ、両者の軸心を近づけることができる。このため、各後リンク軸２７と第２ロッド３７とが直接に連結されていること、及び、第２ロッド３７が各後リンク軸２７よりも前側に位置していて各後リンク軸２７の後側に突出していないこととも相俟って、平行リンク機構２２と第２ロッド３７との連結構造を前後方向でコンパクトにすることができ、その分、弁箱１延いてはゲート弁Ｇの前後厚さを小さくすることができる。
【００４３】
しかも、上記第１ロッド３６は筒状のもので、その内部に第２ロッド３７が挿通されているので、両ロッドを共に中実ロッド状のものとして並立配置する場合に比べ、ロッド３６，３７の配置スペースを小さくでき、弁箱１の大きさをさらに小型化することができる。
【００４４】
また、上記ガイド部材１２の前壁後面において開口１４の下側部と、水平ガイド部１７において下側突出片１６の上面後端部との交差部には面取部１８が形成され、一方、各平行リンク機構２２の下側の各リンク２８の中間部にはその下面を切り欠いた形状の凹部２９が形成されているので、図２に示す如く、各リンク２８が後側部を下げるように後向きに傾斜したときに、上記面取部１８及び凹部２９にそれぞれ相手側部材が入り込むようになり、下側リンク２８の中間部とガイド部材１２前壁後面の開口１４の下側部とが互いに干渉することはない。つまり、ゲート弁Ｇのコンパクト化を図りながら、平行リンク機構２２の各リンク２８の揺動を確保することができる。
【００４５】
尚、上記実施形態では、弁板支持体１０の本体１１後面に各弾性部材６１を弁箱１の後側開口３周囲の後壁内面に押し付けられるように設けているが、逆に、弁箱１の後側開口３周囲の後壁内面に弾性部材６１を弁板支持体１０の本体１１後面に押し付けられるように設けてもよく、両方に設けることもできる。また、弾性部材６１は弁板支持体１０の本体１１後面又は弁箱１の後側開口３周囲の後壁内面において、平行リンク機構２２の上下両側位置のいずれかに設けてもよい。また、このようなゴム製の弾性部材６１に限らず、その他、例えば板ばねやコイルばね等の弾性部材でもよい。
【００４６】
また、上記実施形態では、駆動手段としてエアシリンダ５７を用いているが、液圧シリンダでもよく、その他、回転型のアクチュエータを用いることもでき、電磁型の各種アクチュエータを用いてもよい。また、弁板支持体１０とそれに対し接離する弁板５との連結構造、弁板支持体１０の駆動構造等は上記実施形態に限定されず、本発明の技術思想を損なわない範囲で変更することができる。
【００４７】
また、上記実施形態では、弁板支持体１０及び弁板５を上昇移動させて開弁し、下降移動させて閉弁するようにしているが、逆に弁板支持体１０及び弁板５の下降移動により開弁し、上昇移動により閉弁するようにしてもよい。また、弁板支持体１０及び弁板５の開閉動作の向きを必ずしも上下方向に限定する必要はないのは勿論である。
【００４８】
【発明の効果】
以上説明のように、請求項１の発明によると、真空容器に連通する開口に沿った平面と略平行に移動する弁板支持体と、この弁板支持体に連結手段を介して支持され、弁板支持体に対し接離して開口を開閉する弁板と、この弁板及び上記開口の周囲部の間をシールするシール部材とが設けられてなる真空ゲート弁に対し、弁板支持体又は弁板の閉じ状態で該弁板支持体に対向する固定体の少なくとも一方に、シール部材とは別に突設され、かつ該シール部材のばね定数以下のばね定数を有し、弁板支持体又は固定体の他方に対し弁板の開閉方向に押し付けられて、弁板が開口を閉じた状態で弁板支持体を弁板の閉じ方向に付勢する、シール機能のない弾性部材を備えたことにより、弁板の押付けストロークを適正に保ちつつ、ゲート弁の長期使用に伴って生じるシール構造のガタを弾性部材による弁板支持体の付勢力により吸収して、ゲート弁の真空シール性能や耐圧性能の低下を長期間に亘り抑制でき、連結手段やシール部材のメンテナンスのサイクルの延長化を図ることができる。
【００４９】
請求項２の発明によると、弾性部材はゴム材又は樹脂材としたことにより、望ましい機能を有する弾性部材が具体的に容易に得られる。
【図面の簡単な説明】
【図１】真空ゲート弁の閉弁状態を示す要部拡大側面断面図である。
【図２】真空ゲート弁の弁板が弁箱の前側開口を開いた状態を示す図１相当図である。
【図３】平行リンク機構の一部を拡大して示す部分破断平面図である。
【図４】ガイド部材の拡大正面図である。
【図５】図４のＶ−Ｖ線断面図である。
【図６】真空ゲート弁の全体構成を示す側面図である。
【図７】真空ゲート弁の全体構成を示す正面図である。
【符号の説明】
Ｇ真空ゲート弁
１弁箱（固定体）
２前側開口
５弁板
７シール部材
１０弁板支持体
１２ガイド部材
１３垂直ガイド部
１７水平ガイド部
１８面取部
２２平行リンク機構（連結手段）
２３，２７リンク軸
２７ａ嵌合部
２８リンク
２９凹部
３１，３２ガイドローラ
３６第１ロッド
３７第２ロッド
５７シリンダ
６１弾性部材[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a vacuum gate valve having a valve plate that opens and closes an opening communicating with a vacuum vessel, and particularly relates to a technical field for ensuring stable sealing performance of a valve plate.
[0002]
[Prior art]
  Conventionally, various types of vacuum gate valves of this type are known. For example, in Japanese Utility Model Publication No. 62-199567, a valve plate support is disposed in a valve box having an opening communicating with a vacuum vessel so that the valve plate support can be moved up and down while being guided by a guide roller pivotally supported on the rear surface. A valve plate that opens and closes the opening of the valve box is supported on the front side of the valve plate support through a parallel link mechanism so that the valve plate supports the valve plate when the valve plate support is moved to the valve closing position. A stopper that moves the valve plate relative to the valve plate support in the closing direction is provided, and a cylinder having a piston rod that penetrates the wall of the valve box in an airtight manner is attached outside the valve box. Is connected to the valve plate support in the valve box, the valve plate support is moved in the valve box by the expansion and contraction of the cylinder to open and close the valve plate, and the valve plate support is moved to the valve open position by the cylinder. The valve plate is moved together with the valve plate support. When the valve plate support is moved to the closed position while the valve box opening is opened, the valve plate is brought into contact with the stopper in the middle of the valve plate support and separated from the valve plate support by the parallel link mechanism. The link of the link mechanism is stretched between the valve plate support and the valve plate so that the valve plate is pressed around the opening of the valve box, and the opening is sealed and closed by the valve plate.
[0003]
  In addition, as shown in Japanese Utility Model Laid-Open Nos. 59-152252 and 4-106583, a valve plate is directly attached to the tip of the piston rod of the cylinder, and is a plane along the opening of the valve box. An annular valve plate retainer and a double cylindrical bellows connected to the valve plate retainer are disposed on the rear side of the valve plate in the closed position. It is known that the valve plate in the closed position is brought into contact with and separated from the inner surface of the wall of the valve box to open and close the opening by supplying and discharging pressure fluid to and from.
[0004]
[Problems to be solved by the invention]
  By the way, as in the above-described conventional example (Japanese Utility Model Publication No. 62-199567), the valve plate is supported on the valve plate support through a connecting means such as a parallel link mechanism so that the valve plate can be contacted and separated. When the gate valve is used for a long period of time and the number of times of opening and closing increases when the valve plate is pressed around the opening of the valve box by closing the valve plate support in the closed position and the valve plate is closed. The parts of the connecting means are worn out, or the seal member that hermetically seals between the valve plate and the periphery of the valve box opening is worn out or worn. There has been a problem that the backlash of the structure is generated and the vacuum sealing performance and pressure resistance performance of the gate valve are lowered. For this reason, it is necessary to perform maintenance of a connection means and a sealing member in a short period of time, and there is room for improvement.
[0005]
  The present invention has been made in view of such a point, and an object of the present invention is to provide a means for absorbing the backlash of the sealing structure due to wear of the connecting means of the vacuum gate valve and the sealing member, and the like. An object of the present invention is to suppress the deterioration of the sealing performance and pressure resistance performance and to extend the maintenance cycle of the connecting means and the sealing member.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention focuses on the fact that when the vacuum gate valve is closed, the valve plate is pressed away from the valve plate support and is pressed against the periphery of the opening. The valve plate support, which is the support portion of the valve, is supported in an elastic state with respect to a fixed body such as a valve box, and the backlash of the seal structure is absorbed by this elastic support.
[0007]
  Specifically, in the first aspect of the present invention, a valve plate support that is movable substantially parallel to a plane along the opening communicating with the vacuum vessel, and is supported by the valve plate support via a connecting means, A vacuum gate valve comprising a valve plate that opens and closes an opening in contact with and away from the valve plate support as the plate support moves, and a seal member that seals between the valve plate and the periphery of the opening. It is a premise.
[0008]
  Then, at least one of the valve plate support or the fixed body facing the valve plate support in a closed state of the valve plate is provided separately from the seal member and has a spring constant equal to or less than the spring constant of the seal member. And is pressed against the other of the valve plate support body or the fixed body in the valve plate opening / closing direction and urges the valve plate support body in the valve plate closing direction with the valve plate closed. An elastic member having no sealing function is provided.
[0009]
  With the above configuration, when the gate valve is closed, when the valve plate separated from the valve plate support is pressed against the periphery of the opening and the opening is closed, the elastic member without a sealing function in the closed state of the valve plate Pushes the valve plate support away from the fixed body, and the elastic plate biases the valve plate support in the valve plate closing direction (direction in which the valve plate is pressed against the periphery of the opening). Therefore, even when the gate valve has been used for a long time and the backlash of the seal structure occurs due to wear of the connecting means or the seal member, the backlash is absorbed by the urging force of the valve plate support by the elastic member. In order to compensate, the valve plate is always pressed against the periphery of the opening with a substantially constant pressure. Accordingly, it is possible to extend the maintenance cycle of the connecting means and the seal member by suppressing a decrease in the vacuum seal performance and pressure resistance performance of the gate valve for a long period of time.
[0010]
  In addition, since the spring constant of the elastic member is equal to or less than the spring constant of the seal member that seals between the valve plate and the peripheral portion of the opening, the following effects can be obtained. In other words, the lower the spring constant of the elastic member, the more stable the backlash of the seal structure can be suppressed. On the other hand, the stroke required to press the valve plate against the periphery of the opening in the closed position becomes large. In order to shorten the pressing stroke, it is necessary to increase the spring constant of the elastic member. However, if it is larger than the spring constant of the seal member, it becomes difficult to suppress the backlash of the seal structure. Therefore, by setting the spring constant of the elastic member to be equal to or less than the spring constant of the seal member, the backlash of the seal structure by the elastic member can be effectively obtained while keeping the pressing stroke of the valve plate properly..
[0011]
  Claim2In the invention, the elastic member is made of a rubber material or a resin material. If it carries out like this, the elastic member which has a desirable function will be obtained easily concretely.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
  6 and 7 show a vacuum gate valve G according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the vacuum gate valve G communicates the internal spaces (vacuum spaces) of the vacuum containers C1 and C2 between the first and second vacuum containers C1 and C2 positioned in the front and rear. It arrange | positions so that communication may be interrupted | blocked.
[0013]
  The vacuum gate valve G includes a rectangular valve box 1 (fixed body) sandwiched between the vacuum vessels C1 and C2 in an airtight manner, and the front wall of the valve box 1 (FIGS. 1, 2, and 6). The left side wall) has a front opening 2 communicating with the first vacuum vessel C1, and the rear wall (the right side wall) has a rear opening 3 communicating with the second vacuum vessel C2 at the same height. These openings 2 and 3 are formed in a rectangular shape that is long in the left-right direction (a direction perpendicular to the paper surface of FIG. 6; the left-right direction in FIG. 7) and has the same size. 3, the space in the valve box 1 communicates with the inside of each vacuum vessel C1, C2.
[0014]
  As shown in enlarged views in FIGS. 1 and 2, a valve plate 5 for opening and closing the front opening 2 is disposed in the valve box 1. The valve plate 5 is made of a rectangular plate material that is slightly larger in the left-right direction than the front opening 2, and a seal housing groove 6 that is continuous over the entire valve plate 5 is formed on the outer periphery of the front plate. A rubber seal member 7 is housed and fixed in the groove 6 so as to seal between the valve plate 5 and the inner surface of the front wall around the front opening 2 of the valve box 1 by being pressed against the inner surface of the front wall of the valve box 1. ing.
[0015]
  The valve plate 5 is synchronized with the valve plate support 10 at the two left and right sides (or three or more) on both the left and right sides separated in the left and right direction, which is the length direction thereof, and the parallel link mechanisms 22 and 22 described later by the valve plate support 10. And the front opening 2 is closed. That is, the valve plate support 10 is disposed in the valve box 1 on the rear side of the valve plate 5, and the valve plate support 10 is located at the lower side in the valve box 1 together with the valve plate 5. And a valve closing position corresponding to the front and rear openings 2 and 3 on the upper side in the valve box 1 can be moved up and down substantially parallel to the vertical plane along the front opening 2. The valve plate support 10 has a rectangular plate-shaped main body 11 that is larger than the rear opening 3 of the valve box 1, and the front surface of the main body 11 has portions corresponding to the left and right pressing positions of the valve plate 5. A guide member 12 for guiding the guide rollers 31 and 32 of each parallel link mechanism 22 is integrally attached and fixed by an annular plate-like attachment member 20. That is, as shown in FIGS. 3 to 5, the guide member 12 has a shallow, substantially dish-like shape that opens rearward, and its lower wall portion is notched and opened, and on the outer periphery other than the notched portion. A flange 12a extending radially outward is formed at the rear end of the half, and the mounting member 20 is secured to the bolts 21, 21, ... (1) while the flange 12a is locked to the inner periphery of the mounting member 20. Each guide member 12 is attached and fixed to the front surface of the main body 11 via the attachment member 20 by attaching the main body 11 to the main body 11.
[0016]
  Further, the upper end portion (inner end portion) of the cylindrical first rod 36 is fixed to the lower edge portion of the mounting member 20 in the valve plate support 10 by welding in an airtight manner integrally with the first rod. The valve plate support 10 moves between the valve open position and the valve close position by the up-and-down movement 36 (movement in the length direction).
[0017]
  A vertically long rectangular opening 14 is formed through the center of the front wall (bottom wall) of the guide member 12. Further, on the front surface of the guide member 12, a pair of upper and lower projecting pieces 15, 16 extending in parallel to the horizontal front side from the upper and lower edges of the opening 14 are integrally formed, and the lower surface of the upper projecting piece 15 is formed on the lower surface of the opening 14. The lower surface of the upper edge and the upper surface of the lower protruding piece 16 are flush with the upper surface of the lower edge of the opening 14. A rectangular recess 11 a having a predetermined depth is formed on the front surface of the main body 11 of the valve plate support 10 so as to correspond to the opening 14 of each guide member 12. And the vertical guide part 13 extended in the moving direction (up-down direction) of the 2nd rod 37 mentioned later by the front wall (bottom wall) of the said guide member 12 and the recessed part 11a of the main body 11 is projected on a pair of upper and lower sides again. The horizontal guide portions 17 extending in the moving direction (front-rear direction) of the valve plate 5 are respectively formed by the pieces 15, 16 or the opening 14. Further, as shown in FIG. 5, a lower side portion of the opening 14 on the rear surface of the front wall of the guide member 12 forming the vertical guide portion 13, and a rear end portion of the upper surface of the lower protruding piece 16 on the horizontal guide portion 17. A chamfered portion 18 is formed at the intersection so as to be obliquely cut out in order to avoid interference with a lower link 28 described later.
[0018]
  In each of the left and right guide members 12 of the valve plate support 10, parallel link mechanisms 22 as connecting means for supporting the valve plate 5 so as to be able to contact and separate in the front-rear direction with respect to the valve plate support 10 are arranged. Has been. That is, upper and lower front link shafts 23, 23 extending in the horizontal left-right direction are arranged between the upper and lower protruding pieces 15, 16 in each guide member 12 with a predetermined interval in the vertical direction. The valve plate mounting member 25 is fastened and fixed to the valve plate mounting member 25 by bolts 24 and 24 at the front notches 23a and 23a (see FIG. 3) at the left and right ends. The valve plate mounting member 25 is bolted to the rear surface of the valve plate 5 by bolts 26 and 26. ,...
[0019]
  On the other hand, in the vertical guide portions 13, that is, between the rear surfaces of the front walls of the left and right sides of the opening 14 of the guide member 12 and the bottom surfaces (front surfaces) of the rectangular recesses 11 a on the front surface of the main body 11, The rear link shafts 27, 27 are arranged in the vertical direction at the same interval as the front link shafts 23, 23. As shown in FIG. 3, the front end portions of the left and right links 28, 28 made of resin or the like are swingably supported by the portions located on the left and right sides of the front link shafts 23, respectively. The rear end portion of the rear link shaft 28 is swingably supported on the left and right side portions of the rear link shaft 27 located corresponding to the rear side of the front link shaft 23. They are connected by a pair of links 28, 28. A concave portion 29 is formed in the middle portion of each link 28 by cutting out its lower surface, and when each link 28 is inclined rearward to lower the rear side portion as shown in FIG. The recess 29 prevents interference with the rear end of the upper surface of the lower edge of the opening 14 of the guide member 12.
[0020]
  Further, the upper and lower rear link shafts 27, 27 are attached and fixed to the upper end portion of the second rod 37 extending in the vertical direction inside the guide member 12 at the left and right central portions, respectively, with the gap therebetween. The connecting structure of the upper and lower rear link shafts 27, 27 to the second rod 37 is the same, and the rear link shaft 27 has a fitting portion 27a in which a substantially front half is cut out in a planar shape at the left and right central portions. However, the second rod 37 is formed with fitting portions 37a formed by cutting out substantially the latter half of the second rod 37 in a planar shape, and the rear link shaft 27 and the second rod 37 intersect each other and each of them. In a state of being fitted by the fitting portions 27a and 37a, the bolts 38 that pass through both in the front-rear direction are integrally fastened and fixed. Therefore, the parallel link mechanism 22 is comprised by the said front and rear link shafts 23, 23, 27, 27 and the links 28, 28,.
[0021]
  A front guide roller 31 made of resin or the like that is guided in the horizontal front-rear direction by the horizontal guide portion 17 is rotatably supported at the left and right central portions of the front link shafts 23. That is, the front guide roller 31 on the front link shaft 23 located on the upper side is located on the lower surface of the upper protruding portion 15 of the guide member 12 or the lower surface of the upper edge of the opening 14 and on the front link shaft 23 located on the lower side. The front guide rollers 31 are guided to roll along the upper surface of the lower projecting piece 16 or the upper surface of the lower edge of the opening 14 so as to be movable in the front-rear direction. , 31, the valve plate 5 moves back and forth in a state where it is positioned so as not to move relative to the guide member 12 (valve plate support 10) in the vertical direction.
[0022]
  Further, rear guide rollers 32, 32 made of resin or the like guided in the vertical vertical direction by the vertical guide portion 13 are rotatably supported on the left and right ends of the rear link shafts 27, respectively. That is, the rear guide rollers 32 and 32 are guided by rolling between the rear surface of the front wall on the left and right sides of the opening 14 of the guide member 12 and the bottom surface of each recess 11 a on the front surface of the main body 11.
[0023]
  And when the said valve plate support body 10 exists in the valve-closing position in the valve box 1 upper side, only the 2nd rod 37 is moved up and down inside, and the valve plate 5 is supported by the parallel link mechanism 22 to the valve plate. The front opening 2 of the valve box 1 is opened and closed by moving in the front-rear direction (the arrangement direction of both vacuum vessels C1 and C2) so as to be in contact with and away from the body 10, and the second rod 37 is lowered as shown in FIG. When this is done, each link 28 of the parallel link mechanism 22 is tilted downward toward the rear side, and the valve plate 5 is brought close to the valve plate support 10 (second rod 37) so that the valve box 1 While opening the opening 2 by separating it from the front wall around the front opening 2, as shown in FIG. 1, when the second rod 37 is raised, each link 28 of the parallel link mechanism 22 is leveled in the front-rear direction. The valve plate 5 is separated from the valve plate support 10 and the front side By pressing the front wall inner surface around the mouth 2, so as close the opening 2.
[0024]
  Between the front end of each mounting member 20 in the valve plate support 10 and the rear surface of each front valve plate mounting member 25, a metal cylindrical mechanism housing bellows 34 can be expanded and contracted in the contact / separation direction between them. Is provided. The front and rear ends of the mechanism housing bellows 34 are welded to the valve plate mounting member 25 and the mounting member 20 in an airtight manner, respectively. The mechanism housing bellows 34, the valve plate 5 (valve plate mounting member 25), and the valve plate support. The parallel link mechanism 22 is accommodated in an airtight space surrounded by 10. That is, the mechanism housing bellows 34 is configured to contain dust generated from the parallel link mechanism 22 in a sealed space and prevent release into the valve box 1.
[0025]
  The movement in which the valve plate support 10 moves up and down between the valve opening position and the valve closing position in the valve box 1 and the movement in which the valve plate 5 contacts and separates from the valve plate support 10 are both valve box 1. This is performed by driving from the outside of the bottom wall. That is, openings 1a and 1a are formed in a portion of the bottom wall of the valve box 1 directly below each parallel link mechanism 22 (a portion corresponding to the left and right pressing positions of the valve plate 5), and the bottom surface of each opening 1a. The upper end portion of the bottomed cylindrical portion 40 that extends in the vertical direction and has an open upper end is joined concentrically and in an airtight manner, and a central hole 40a is formed through the center of the bottom portion of the cylindrical portion 40. Yes. Further, a cylindrical stopper 41 is concentrically connected and fixed to the lower side of the cylindrical portion 40.
[0026]
  The first rod 36 is inserted into the opening 1a or the tube portion 40 of the bottom wall of the valve box 1, and the lower end portion (outer end portion) of the first rod 36 passes through the center hole 40a at the bottom portion of the tube portion 40. After penetrating in an airtight manner, the inside of the stopper 41 outside the valve box 1 extends downward and protrudes downward, and a disk-like upper plate 42 is fixedly attached to the lower end of the stopper 41 in a movable manner. The valve plate support 10 is moved between the valve opening position and the valve closing position by moving the rod 36 up and down (moving in the length direction), and a bellows mounting flange 54 described later is moved substantially to the position of the bottom wall of the valve box 1. This is set to the valve opening position of the valve plate support 10, and the time when the upper plate 42 contacts the lower surface of the stopper 41 is set to the valve closing position.
[0027]
  On the other hand, the second rod 37 for opening and closing the valve plate 5 with respect to the valve plate support 10 is inserted into the cylindrical first rod 36 so as to be slidable in the vertical direction. The second rod 37 is inserted through the insertion hole 20a formed concentrically with the first rod 36 at the lower end portion of the mounting member 20 in the valve plate support 10, and the upper end portion is the valve plate support as described above. It is located in the guide member 12 of the body 10 and is connected to the rear link shafts 27, 27 of the parallel link mechanism 22 so as to move together. The lower end portion (outer end portion) of the second rod 37 protrudes from the lower end portion of the first rod 36 and extends outside the valve box 1, and the lower plate has a disk-like lower plate having the same diameter as the upper plate 42. 43 is moved and integrated and fixed, and the second rod 37 slides relative to the first rod 36 and moves in the length direction to switch between the open state and the closed state of the valve plate 5, When the lower plate 43 is farthest from the upper plate 42 and the link mechanisms 46, 46 described later are extended, the valve plate 5 is in an open state approaching the valve plate support 10, and the lower plate 43 is moved to the upper plate 42. When the link mechanisms 46 and 46 are contracted most closely, the valve plate 5 is in a closed state separated from the valve plate support 10.
[0028]
  As shown in FIG. 7, one air cylinder 57 as drive means is drivingly connected to the lower plates 43, 43 at the lower ends of the left and right second rods 37, 37. That is, the air cylinder 57 has a cylinder axis in the vertical direction arranged at a central lower position between the left and right pressing positions of the valve plate 5, and its upper end is fixed to the valve box 1 so as not to be relatively movable. ing. The left and right center portion of the bracket 58 is connected to the upper end (tip) of the piston rod 57 a of the cylinder 57. The bracket 58 is formed of a member bent in a substantially U shape so that the left and right end portions are lower than the left and right center portions, and the left and right lower plates 43 and 43 are connected to the left and right end portions, respectively. By extending and contracting one cylinder 57, the left and right second rods 37, 37 connected to the upper end of the piston rod 57a via the bracket 58 are moved up and down in the length direction, and the first rod 36, The valve plate support 10 is moved up and down between the valve opening position and the valve closing position by integral movement with the valve 36, and the valve plate 5 is switched between the open state and the closed state by moving only the second rods 37 and 37. I am doing so.
[0029]
  A compression spring 44 disposed around the lower end of the second rod 37 is mounted between the upper and lower plates 42 and 43 outside the valve box 1, and the second rod 37 is compressed by the compression spring 44. Is urged against the first rod 36 so that the valve plate 5 approaches the valve plate support 10 and moves downward relative to the front opening 2 of the valve box 1.
[0030]
  Further, as shown in FIG. 6, the upper and lower plates 42 and 43 are connected to each other by a pair of link mechanisms 46 and 46 disposed at positions opposed to each other in the diameter direction. Each link mechanism 46 has an upper link 47 whose upper end is pivotally supported on the upper plate 42 so as to be able to swing with a horizontal axis, and a horizontal connecting shaft 49 whose upper end is supported by the lower end of the upper link 47. And a lower link 48 pivotally supported by the lower plate 43 with a horizontal axis so that the guide roller 50 rotates. Supported as possible. When the link mechanisms 46 are extended so that the upper and lower links 47 and 48 are aligned substantially in the vertical direction, the lower plate 43 is separated from the upper plate 42 and the valve plate 5 is moved to the valve plate support 10. On the other hand, when the link mechanism 46 is contracted so that the upper and lower links 47 and 48 are bent outward (the side where the connecting shaft 49 is separated from the second rod 37), the lower plate 43 is moved closer to the upper plate 42. Thus, the valve plate 5 is separated from the valve plate support 10.
[0031]
  In addition, link restricting portions 52 and 52 having a predetermined length corresponding to the stroke of the cylinder 57 are arranged and fixed immediately below the stoppers 41. The both link restricting portions 52, 52 are arranged so as to face each other so that the upper and lower plates 42, 43 move up and down with a predetermined gap therebetween. From the side, the left and right end portions of the bracket 58 are inserted so as to be movable up and down, and the link mechanisms 46 are extended or contracted in accordance with the raising and lowering operations of the lower plates 43 caused by the expansion and contraction operation of the cylinder 57. When the valve plate support 10 is moved up and down between the valve opening position and the valve closing position in accordance with the expansion and contraction operation of the cylinder 57, the valve plate support 10 is in a state other than the valve closing position at the rising end. Each link mechanism 46 is guided to roll within the link restricting portion 52 (between both link restricting portions 52 and 52), and the guide roller 50 on the connecting shaft 49 between the upper and lower links 47 and 48 is rolled on the inner surface of each link restricting portion 52 Is In the state where the valve plate support 10 is in the closed position at the rising end, each link mechanism 46 is projected from the upper end of the link restricting portion 52 and switched to the contracted state. Yes. In addition, the upper end surface of each link restriction | limiting part 52 is an outer side toward the upper side (side which leaves | separates from the other party link restriction | limiting part 42) so that the protrusion to the inside of the link restriction | limiting part 52 at the time of the raising / lowering of the said guide roller 50 may be performed smoothly. It is formed in the inclined surface which inclines to.
[0032]
  A bellows mounting flange 54 is integrally attached and fixed in an airtight manner to a portion near the upper end of the first rod 36 at the lower part in the valve box 1. On the lower surface of the bellows mounting flange 54, an upper end portion of a metal telescopic rod accommodating bellows 55 disposed around the first rod 36 is fixed in an airtight manner, and a lower end portion of the rod accommodating bellows 55 is The bottom wall of the valve box 1 is welded and fixed in an airtight manner to the upper surface of the bottom portion of the cylindrical portion 40, and the penetrating portion of the first rod 36 is covered in an airtight manner by the rod housing bellows 55.
[0033]
  Further, on the rear surface of the main body 11 of the valve plate support 10, both the upper and lower sides of each of the left and right parallel link mechanisms 22 are provided.positionUpper and lower elastic member mounting grooves 60, 60 extending in the left-right direction are formed, and each mounting groove 60 has an elastic member 61 made of a round bar-like rubber (which may be made of resin) having substantially the same length as the mounting groove 60. A part of the elastic member 61 is accommodated in a state of protruding from the rear surface of the main body 11, and each elastic member 61 is mounted and held in the mounting groove 60 by a holding member 62 that is screwed. The elastic members 61 are arranged on the inner surface (front surface) of the rear wall around the rear opening 3 facing the valve plate support 10 in the valve box 1 in a closed state where the valve plate 5 closes the front opening 2 of the valve box 1. The valve plate support 10 is urged forward by the elastic reaction force of the elastic member 61 in the pressed state, and the spring of the elastic member 61 is urged forward. The constant is set to be equal to or less than the spring constant of the seal member 7 around the front surface of the valve plate 5.
[0034]
  Next, the operation of the above embodiment will be described. When the vacuum gate valve G is open, the cylinder 57 contracts and is at the stroke end. For this reason, the upper and lower plates 42 and 43 are located between the link restricting portions 52 and 52 together with the link mechanisms 46 and 46 for connecting the two, and each link mechanism 46 extends so that the plates 42 and 43 are separated from each other. Yes. Thus, the valve plate support 10 is in the valve open position, and the upper end portion of the second rod 37 is positioned on the lower side in the valve plate support 10 so that each link 28 of each parallel link mechanism 22 is It inclines so that it may go down toward the rear side (refer FIG. 2), the valve plate 5 exists in the position which approached the valve plate support body 10, and is spaced apart from the front wall inner surface of the valve box 1. FIG. Further, both the mechanism housing bellows 34 and the rod housing bellows 55 are contracted.
[0035]
  When the gate valve G is closed from this state, the cylinder 57 extends and the piston rod 57a rises. As the piston rod 57a moves upward, the lower plates 43 connected to the upper ends of the piston rods 57a via the brackets 58 and the second rods 37 connected to the lower plates 43 of the lower ends rise. . At this time, the link mechanisms 46 and 46 connecting the lower plate 43 and the upper plate 42 are constrained in an extended state therebetween by the link restricting portions 52 and 52, respectively, and between the plates 42 and 43. Since the compression spring 44 is interposed, as the lower plate 43 moves upward, the upper plate 42 rises following the lower plate 43 while being separated from the lower plate 43, and relative movement between the two does not occur. As a result, the rod receiving bellows 55 is extended, the first rod 36 is raised together with the upper plate 42, and the valve plate support 10 connected to the upper end of the first rod 36 is closed from the valve opening position. It rises with the valve plate 5 toward the valve position. Further, since the relative movement between the first and second rods 36 and 37 does not occur, the valve plate 5 does not switch to the closed state, and the valve plate 5 is kept close to the valve plate support 10. When it is raised, it does not contact the inner surface of the front wall of the valve box 1.
[0036]
  When the cylinder 57 further extends and reaches near the end of the extension stroke, the upper plate 42 comes into contact with the lower surface of the stopper 41 joined to the cylindrical portion 40 on the lower surface of the bottom wall of the valve box 1 and further moves upward. Be regulated. As a result, as shown in FIG. 2, the valve plate support 10 stops at the valve closing position, and the valve plate 5 is positioned at a position corresponding to the front opening 2 in the valve box 1. In this state, each of the link mechanisms 46 starts to come out from the upper end of the link restricting portion 52, and further expansion operation of the cylinder 57 changes the link mechanisms 46 to a contracted state and compresses the compression spring 44. Only the lower plate 43 ascends with respect to the upper plate 42 that is restricted by the stopper 41. As a result, as shown in FIG. 1, only the second rod 37 rises relative to the valve plate support 10 that is stopped and held together with the first rod 36, and only the second rod 37 rises. By moving the mechanism accommodating bellows 34, the links 28 of the parallel link mechanisms 22 rotate horizontally in the front-rear direction, and the valve plate 5 moves to the front side away from the valve plate support 10 to move the valve. The inner surface of the front wall around the front opening 2 of the box 1 is pressed, the opening 2 is airtightly closed by the seal member 7, and the gate valve G is closed.
[0037]
  On the other hand, when the gate valve G in the closed state as described above is opened, the cylinder 57 is contracted and the piston rod 57a is lowered. As the piston rod 57a is moved downward, each lower plate 43 is lowered together with the second rod 37, and the downward movement of the second rod 37 causes the mechanism housing bellows 34 to be contracted, while each of the parallel link mechanisms 22 is contracted. The link 28 rotates in the inclined direction, the valve plate 5 moves in the rearward direction approaching the valve plate support 10, leaves the inner surface of the front wall around the front opening 2 of the valve box 1, and the opening 2 is opened. Thereafter, the first and second rods 36 and 37 are integrally lowered by the restriction of the extension of the link mechanism 46 by the link restricting portion 52, and the valve plate support 10 is moved together with the valve plate 5 to the valve opening position. G opens.
[0038]
  In this embodiment, the elastic members 61 and 61 are respectively provided in the elastic member mounting grooves 60 and 60 on both the upper and lower sides of the left and right parallel link mechanisms 22 and 22 on the rear surface of the main body 11 of the valve plate support 10. Since a part of the valve 11 is filled in a state of protruding from the rear surface of the main body 11, when the gate valve G is closed, the valve plate 5 separated from the valve plate support 10 is the front wall around the front opening 2 of the valve box 1. When the opening 2 is closed by being pressed against the inner surface, each of the elastic members 61 is pressed against the inner surface (front surface) of the rear wall around the rear opening 3 of the valve box 1 to be compressively deformed. Due to the elastic reaction force of the member 61, the valve plate support 10 is urged forward with respect to the valve box 1 in the closing direction of the valve plate 5. Thus, by energizing the valve plate support 10 in the closing direction of the valve plate 5 when the valve is closed, the valve box 1 is temporarily caused by wear of each parallel link mechanism 22 or the seal member 7 with long-term use of the gate valve G. Even if backlash occurs in the seal structure of the valve plate 5 with respect to the front opening 2, the backlash is absorbed by the urging force of the valve plate support 10 by the elastic member 61. That is, even if the play occurs, the valve plate 5 is always pressed against the inner surface of the front wall around the front opening 2 with a substantially constant pressure so as to compensate for this. As a result, the deterioration of the vacuum sealing performance and pressure resistance performance of the gate valve G is suppressed for a long period of time, and the maintenance cycle for the parallel link mechanism 22 and the sealing member 7 can be extended accordingly.
[0039]
  The elastic members 61 are arranged on the upper and lower sides of the left and right parallel link mechanisms 22 and 22 on the rear surface of the main body 11 of the valve plate support 10.In positionAnd since it is arrange | positioned in the position which receives reaction force concentratedly from the valve plate 5 of a closed state, the play of the said seal structure is absorbed reliably and an effective effect is acquired.
[0040]
  Further, since the spring constant of the elastic member 61 is equal to or less than the spring constant of the seal member 7 that seals between the valve plate 5 and the inner surface of the front wall around the front opening 2, the pressing stroke of the valve plate 5 is maintained appropriately. On the other hand, the backlash suppression effect of the seal structure by the elastic member 61 is obtained. That is, the lower the spring constant of the elastic member 61, the more stable the backlash of the seal structure can be suppressed. On the other hand, the stroke in the front-rear direction for pressing the valve plate 5 against the inner surface of the front wall of the valve box 1 increases. In order to shorten the pressing stroke, it is necessary to increase the spring constant of the elastic member 61. However, if the spring constant becomes larger than the spring constant of the seal member 7, it is difficult to suppress the backlash of the seal structure. It becomes. Therefore, by setting the spring constant of the elastic member 61 to be equal to or less than the spring constant of the seal member 7, it is possible to achieve both optimization of the pressing stroke of the valve plate 5 and the effect of suppressing the backlash of the seal structure by the elastic member 61. .
[0041]
  Furthermore, in this embodiment, the front guide rollers 31 are provided at the left and right center portions of the front link shafts 23 of the parallel link mechanisms 22, and the left and right rear guide rollers 32 and 32 are provided at the left and right sides of the rear link shaft 27. And the front guide roller 31 on the front link shaft 23 located on the upper side protrudes upward of the guide member 12 at the horizontal guide portion 17 when the valve plate 5 moves back and forth with the up and down movement of only the second rod 37. The front guide roller 31 on the front link shaft 23 located along the lower surface of the piece 15 or the upper edge of the opening 14 and also on the lower side is along the upper surface of the lower protruding piece 16 or the upper surface of the lower edge of the opening 14. Each of the rear guide rollers 32 is movably guided in the front-rear direction, and each rear guide roller 32 has a vertical guide portion 13, i.e. It is guided by rolling between the shape recess 11a bottom. Each link 28 can be smoothly swung by guiding the guide rollers 31 and 32 by the horizontal guide portion 17 and the vertical guide portion 13, and the contact and separation of the valve plate 5 with respect to the valve plate support 10 can be performed smoothly. Is called. That is, the vertical guide portion 13 and the horizontal guide portion 17 are provided on the valve plate support 10, and the guide rollers 31 and 32 of the parallel link mechanism 22 are guided by rolling by the guide portions 13 and 17. The operation of each parallel link mechanism 22 can be made smooth while the body 10 has a compact structure.
[0042]
  Further, the rear link shafts 27 and the second rods 37 in the parallel link mechanisms 22 are cut out at the fitting portions 27a in which the front side of the rear link shafts 27 are cut out and the rear side portions of the second rods 37 are cut out. Since the fitting portions 37a are fitted and fastened in a state of crossing each other, the shaft centers of the fitting portions 27a and 37a can be brought closer to each other by the notches. Therefore, the rear link shafts 27 and the second rods 37 are directly connected, and the second rods 37 are positioned in front of the rear link shafts 27 so that the rear link shafts 27 Combined with the fact that it does not protrude to the side, the connecting structure of the parallel link mechanism 22 and the second rod 37 can be made compact in the front-rear direction. The thickness can be reduced.
[0043]
  Moreover, since the first rod 36 is cylindrical and the second rod 37 is inserted into the first rod 36, the rods 36 and 37 are compared with the case where both rods are arranged side by side as solid rods. The arrangement space can be reduced, and the size of the valve box 1 can be further reduced.
[0044]
  Further, a chamfered portion 18 is formed at an intersection between the lower side portion of the opening 14 on the rear surface of the front wall of the guide member 12 and the upper surface rear end portion of the lower protruding piece 16 in the horizontal guide portion 17, Since a concave portion 29 is formed in the lower portion of each link 28 on the lower side of each parallel link mechanism 22 so that the lower surface is cut off, each link 28 lowers the rear side portion as shown in FIG. The other side member enters the chamfered portion 18 and the recessed portion 29, respectively, and the intermediate portion of the lower link 28 and the lower side portion of the opening 14 on the rear surface of the front wall of the guide member 12 are connected to each other. They do not interfere with each other. That is, the swing of each link 28 of the parallel link mechanism 22 can be ensured while the gate valve G is made compact.
[0045]
  In the above embodiment, each elastic member 61 is provided on the rear surface of the main body 11 of the valve plate support 10 so as to be pressed against the inner surface of the rear wall around the rear opening 3 of the valve box 1. The elastic member 61 may be provided on the inner surface of the rear wall around the rear opening 3 so as to be pressed against the rear surface of the main body 11 of the valve plate support 10 or may be provided on both. The elastic member 61 is located behind the main body 11 of the valve plate support 10.Face or faceIs the rear opening 3 rounds of the valve box 1GoOn the inner surface of the rear wallLeaveThe parallel link mechanism 22 may be provided at either of the upper and lower positions. Further, the elastic member 61 is not limited to such a rubber elastic member 61 but may be an elastic member such as a leaf spring or a coil spring.
[0046]
  In the above-described embodiment, the air cylinder 57 is used as the driving means. However, a hydraulic cylinder may be used. In addition, a rotary actuator may be used, and various electromagnetic actuators may be used. Further, the connection structure between the valve plate support 10 and the valve plate 5 that contacts and separates from the valve plate support 10 and the drive structure of the valve plate support 10 are not limited to the above-described embodiments, but can be changed within the range not impairing the technical idea of the present invention. can do.
[0047]
  In the above embodiment, the valve plate support 10 and the valve plate 5 are moved upward to open, and the valve plate support 10 and the valve plate 5 are closed to move downward. The valve may be opened by the downward movement and closed by the upward movement. Of course, the direction of the opening / closing operation of the valve plate support 10 and the valve plate 5 is not necessarily limited to the vertical direction.
[0048]
【The invention's effect】
  As explained above, the claims1According to the present invention, the valve plate support that moves substantially parallel to the plane along the opening communicating with the vacuum vessel, the valve plate support supported by the connecting means, and contacted and separated from the valve plate support. With respect to a vacuum gate valve provided with a valve plate that opens and closes an opening and a seal member that seals between the valve plate and a peripheral portion of the opening, the valve plate is closed when the valve plate support or the valve plate is closed. At least one of the fixed bodies facing the support body is protruded separately from the seal member and has a spring constant equal to or less than the spring constant of the seal member, and the valve plate is in contact with the other of the valve plate support body or the fixed body. Providing an elastic member without a sealing function that presses in the opening and closing direction and biases the valve plate support in the valve plate closing direction with the valve plate closed. The seal structure that occurs with long-term use of the gate valve The backlash can be absorbed by the urging force of the valve plate support by the elastic member, and the deterioration of the vacuum seal performance and pressure resistance performance of the gate valve can be suppressed for a long time, and the maintenance cycle of the connecting means and seal member can be extended. Can be planned.
[0049]
  Claim2According to the invention, the elastic member is made of a rubber material or a resin material, so that an elastic member having a desired function can be easily obtained.
[Brief description of the drawings]
FIG. 1 is an enlarged side sectional view of a main part showing a closed state of a vacuum gate valve.
FIG. 2 is a view corresponding to FIG. 1, showing a state in which the valve plate of the vacuum gate valve opens the front opening of the valve box.
FIG. 3 is a partially broken plan view showing a part of the parallel link mechanism in an enlarged manner.
FIG. 4 is an enlarged front view of a guide member.
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a side view showing the overall configuration of the vacuum gate valve.
FIG. 7 is a front view showing the overall configuration of the vacuum gate valve.
[Explanation of symbols]
  G Vacuum gate valve
  1 Valve box (fixed body)
  2 Front opening
  5 Valve plate
  7 Seal member
  10 Valve plate support
  12 Guide members
  13 Vertical guide
  17 Horizontal guide
  18 Chamfer
  22 Parallel link mechanism (connecting means)
  23, 27 Link shaft
  27a Fitting part
  28 links
  29 recess
  31, 32 Guide roller
  36 First rod
  37 Second rod
  57 cylinders
  61 Elastic member

Claims

A valve plate support that can move substantially parallel to a plane along the opening that communicates with the vacuum vessel, and is supported by the valve plate support via a coupling means. The valve plate support is moved along with the movement of the valve plate support. In a vacuum gate valve provided with a valve plate that opens and closes an opening by contacting and separating, and a seal member that seals between the valve plate and the periphery of the opening,
At least one of the valve plate support or the fixed body facing the valve plate support in a closed state is provided separately from the seal member and has a spring constant equal to or less than the spring constant of the seal member. And pressed against the other of the valve plate support or the fixed body in the valve plate opening / closing direction to urge the valve plate support in the valve plate closing direction with the valve plate closed. A vacuum gate valve comprising an elastic member having no sealing function.

The vacuum gate valve of claim 1 ,
The vacuum gate valve, wherein the elastic member is made of a rubber material or a resin material.