JP4299581B2

JP4299581B2 - Metal seal

Info

Publication number: JP4299581B2
Application number: JP2003139843A
Authority: JP
Inventors: 哲哉芦田; 弘紀笈田; 孝禎三ツ井
Original assignee: Mitsubishi Cable Industries Ltd
Current assignee: Mitsubishi Cable Industries Ltd
Priority date: 2003-05-19
Filing date: 2003-05-19
Publication date: 2009-07-22
Anticipated expiration: 2023-05-19
Also published as: JP2004340315A

Description

【０００１】
【発明の属する技術分野】
本発明は、金属シールに関する。
【０００２】
【従来の技術】
真空、又は内圧外圧の固定フランジ用のシールとしては、従来、ゴムや樹脂等の様々な材料が使用されてきた。特に、高真空・高圧の内圧又は外圧用、高温・低温、及び、腐食性流体への適用等の過酷な条件下では、金属シールが用いられる場合が多い。
【０００３】
【発明が解決しようとする課題】
しかしながら、この金属シールには次のような問題がある。即ち、従来の金属シールは一般に締付力が高く、そのため、相手部材（シール取付部材）としてのフランジ等の肉厚を増加せねばならず、装置の重量増加及び容積（スペース）増加等の問題が発生する。
また、従来、横断面楕円形や円形の金属シールが使用されていた（図示省略）が、相互に平行な一対の平坦面の間に、このような楕円形や円形の金属シールを圧接状に装着した場合、平坦面との圧接シール部分で、局部的に塑性変形を生じ、平坦面───つまりフランジ等の相手部材───に損傷を与え、フランジ等の相手部材の再使用（繰返し使用）に関して問題を生じていた。また、保守・点検等の解体時に、高いメンテナンスコストとメンテナンス時間を要していた。
【０００４】
上述の横断面楕円形や円形の金属シールが相手部材の平坦面に損傷を与える理由は、この金属シールの剛性高さの故に、ほとんど弾性変形することができず、一対の平坦面が相互に接近しようとする方向の締付力をそのまま受けて、局部的に塑性変形（圧潰）を受けるためである。
要するに、従来の金属シールでは作成が容易で、締付力が小さく、かつ、弾性的復元量が大きく、相手部材（平坦面）を局部的に圧潰せず（損傷を与えない）という全ての条件を満足させ得るものが知られていなかった。
【０００５】
そこで、本発明者等は、図６に例示するような横断面形状の金属シール30を、特願２００２−２１１０９７にて提案した。即ち、この金属シール30は、相互に平行な第１平坦面部31と第２平坦面部32の間に介装され、全体が環状であり、横断面矩形状の中間基部33と、第１平坦面部31に当接する内径寄りの半円形の第１接触凸部36と、第２平坦面部32に当接する外径寄りの半円形の第２接触凸部37とを、有し、そして、装着圧縮状態（使用状態）では、相互に接近する第１・第２平坦面部31・32から受ける押圧力Ｆ₁ ，Ｆ₂ によって、中間基部33を中心に捩れ弾性変形を生じ、その捩れ弾性変形に伴う弾性的反発力により、第１接触凸部36は第１平坦面部31に圧着・圧接し、かつ、第２接触凸部37は第２平坦面部32に圧着・圧接して、密封（シール）作用をなさしめるものである。
【０００６】
この図６のように、締付力（矢印Ｆ₁ ，Ｆ₂ 参照）が小さく、復元性に優れた金属シールを提案したのであったが、流体圧力Ｐ…が高い使用条件───例えば10ＭPa以上の圧力───では、図６（Ｂ）の矢印Ｚ方向に、第２接触凸部37が第２平坦面部32から浮上り、矢印Ｇ方向に流体洩れ（ブローバイ）を発生する虞のあることが、その後の本発明者等の試作実験等の検討の結果判明した。
即ち、図６（Ｂ）に示す如く、金属シール30に高圧の流体圧力Ｐが作用すると、比較的小さな締付力（押圧力）Ｆ₁ ，Ｆ₂ にて捩れ弾性変形中の金属シール30は、図６（Ｂ）に示した実線から２点鎖線のように、簡単に矢印Ｚ方向に浮上る現象を生じ、矢印Ｇ方向へ流体洩れ（ブローバイ）を発生する。
【０００７】
本発明の目的は、（金属シールでありながら）締付力が小さく、復元性に優れ、相手部材としてのフランジ等の肉厚を薄くでき、装置の軽量化とコンパクト化を図り、しかも、高圧作用時に、ブローバイ等の流体洩れを有効に防止できて、優れた密封（シール）性を発揮する金属シールを提供することにある。
【０００８】
【課題を解決するための手段】
そこで、本発明は、相互に平行な第１接触平坦面部と第２接触平坦面部の間に介装される全体が環状の金属シールに於て、中間基部と、上記第１接触平坦面部に当接する内径寄りの第１接触凸部と、上記第２接触平坦面部に当接する外径寄りの第２接触凸部と、を備え、装着圧縮状態にて、上記第１・第２平坦面部から受ける押圧力によって上記中間基部を中心に捩れ弾性変形を生ずるように構成され、かつ、内径側圧力作用時に上記第１接触平坦面部に当接して過大捩れ弾性変形を防ぐ横断面小三角形状の第１補助突起を外径寄りに有する。
【０００９】
また、相互に平行な第１接触平坦面部と第２接触平坦面部の間に介装される全体が環状の金属シールに於て、中間基部と、上記第１接触平坦面部に当接する内径寄りの第１接触凸部と、上記第２接触平坦面部に当接する外径寄りの第２接触凸部と、を備え、装着圧縮状態にて、上記第１・第２平坦面部から受ける押圧力によって上記中間基部を中心に捩れ弾性変形を生ずるように構成され、かつ、圧力作用時に上記第１・第２接触平坦面部に各々当接して過大捩れ弾性変形を防ぐ横断面小三角形状の第１・第２補助突起を外径寄り・内径寄りに有する。
【００１０】
また、相互に平行な第１接触平坦面部と第２接触平坦面部の間に介装される全体が環状の金属シールに於て、中間基部と、上記第１接触平坦面部に当接する内径寄りの第１接触凸部と、上記第２接触平坦面部に当接する外径寄りの第２接触凸部と、を備え、装着圧縮状態にて、上記第１・第２平坦面部から受ける押圧力によって上記中間基部を中心に捩れ弾性変形を生ずるように構成され、かつ、外径側圧力作用時に上記第２接触平坦面部に当接して過大捩れ弾性変形を防ぐ横断面小三角形状の第２補助突起を内径寄りに有する。
【００１１】
【発明の実施の形態】
以下、図示の実施の形態に基づき、本発明を詳説する。
図１及び図２は、本発明に係る金属シール（メタルシール）Ｓの実施の一形態を示し、図１は自由状態（未装着状態）の断面正面図であり、図２は使用状態───装着圧縮状態───を示す要部断面説明図である。
【００１２】
この金属シールＳは、ステンレス鋼やばね用鋼やその他の金属から成り、切削や研削等の機械加工にて作製される。
この金属シールＳは、相互に平行な第１接触平坦面部１と第２接触平坦面部２の間に介装されるものであって、全体が円形，楕円，長円，略矩形等の環状である。横断面形状について説明すれば、略矩形（長方形）の中間基部３と、略半円形の第１接触凸部11と第２接触凸部12と、から成る。第１接触凸部11は中間基部３の内径寄りに、第２接触凸部12は中間基部３の外径寄りに、夫々配設される。
装着状態で、内径寄りの第１接触凸部11は第１接触平坦面部１に当接し、外径寄りの第２接触凸部12は第２接触平坦面部２に当接する。
【００１３】
図１の右半分、及び、図２に於て、２点鎖線によって、中間基部３と、第１・第２接触凸部11，12との境界線を示す。図示省略したが、装着未圧縮状態では、この中間基部３の（図の）上下の長辺側端面５，６は、フランジ等の取付部材（相手部材）７，８の前記第１・第２接触平坦面１，２と、平行状態である。なお、図示省略するが、上下の長辺側端面５，６の一方又は両方を、第１・第２接触平坦面１，２と平行でない状態（傾斜状）としても良い場合がある。その後、取付部材（相手部材）７，８が相互に接近してゆけば、図２に示した装着圧縮状態となる。図２の装着圧縮状態にて、第１・第２平坦面部１，２から受ける押圧力Ｆ₁ ，Ｆ₂ によって中間基部３を中心に捩れ弾性変形を生じる。
【００１４】
そして、21は小三角形状の第１補助突起であり、中間基部３の（図の上方の）端面５の外径寄りに配設されて、図２のように流体圧力Ｐによる圧力が作用した時（圧力作用時）に、この外径寄りの第１補助突起21は第１接触平坦面部１に当接し、過大捩れ弾性変形を防ぐ。
また、22は小三角形状の第２補助突起であり、中間基部３の（図の下方の）端面６の内径寄りに配設されて、図２のように圧力作用時に、この第２補助突起22は第２接触平坦面部２に当接し、過大捩れ弾性変形を、同時に防ぐ作用をなしている。流体圧力Ｐが高いときに、上記第１補助突起21・第２補助突起22による過大捩れ弾性変形防止効果は特に発揮される。しかしながら、流体圧力Ｐが低圧のとき（又は真空）であっても、金属シールＳ自体がクリープ現象で変形することを、上記第１・第２補助突起21, 22が防止できる。
【００１５】
横断面に於て、中間基部３の一端面５の内径寄りには第１接触凸部11が、外径寄りには第１補助突起21が、夫々突出状に、配設され、第１補助突起21の高さ寸法（突出寸法）Ｈ₂₁は、第１接触凸部11の高さ寸法（突出寸法）Ｈ₁₁よりも小さく設定されている。つまり、Ｈ₂₁＜Ｈ₁₁とする。
他方、中間基部３の他端面６の外径寄りには第２接触凸部12が、内径寄りには第２補助突起22が、夫々突出状に、配設され、第２補助突起22の高さ寸法（突出寸法）Ｈ₂₂は、第２接触凸部12の高さ寸法（突出寸法）Ｈ₁₂よりも小さく設定されている。つまり、Ｈ₂₂＜Ｈ₁₂とする。
【００１６】
このように、断面矩形状の中間基部３に対し、内径側と外径側に相互に（ラジアル方向に）位置をずらせて、かつ、軸心Ｌ方向に相反する方向に、第１接触凸部11と第２接触凸部12を突設している。かつ、第１補助突起21と第２補助突起22は、同時に、断面矩形状の中間基部３に対し、内径側と外径側に相互に（ラジアル方向に）位置をずらせて、かつ、軸心Ｌ方向に相反する方向に、突設する。しかも、断面矩形状の中間基部３の（内周面を成す）短辺９と略半円形の第１接触凸部11とは（段差のない）連続状であり、かつ、断面小三角形状の第２補助突起22は上記短辺９から折曲線状に連続形成されており、（段差がなく、）断面矩形状の中間基部３の角部に配設されている場合を示している。
【００１７】
さらに、断面矩形状の中間基部３の（外周面を成す）他の短辺10と略半円形の第２接触凸部12とは（段差のない）連続状であり、かつ、断面小三角形状の第１補助突起21は上記短辺10から折曲線状に連続形成されており、（段差がなく、）断面矩形状の中間基部３の角部に配設されている。このように、第１補助突起21と第２補助突起22とは、中間基部３の重心点に関して点対称位置にあるといえる。また、前述の第１接触凸部11と第２接触凸部12とは、上記重心点に関して点対称位置にあるといえる。
【００１８】
なお、図１と図２の実施の形態に於て、第１・第２補助突起21, 22の位置を、短辺９又は短辺10と折曲線状に連続する角位置とせず、中角基部３の上記角位置から、僅かに内側に移転させて、端面５，６から、突出状に設けるも、自由である（図示省略）。
【００１９】
そして、図１に示した自由状態の金属シールＳを、第１・第２接触平坦面部１，２の間に装着して、この第１・第２接触平坦面部１，２を相互に接近させて、図２に示す装着圧縮状態に近づけてゆけば、一対の第１・第２接触平坦面部１，２から受ける押圧力Ｆ₁ ，Ｆ₂ によって、この金属シールＳは中間基部３（の重心）を中心として、回転して（倒れて）捩れ弾性変形を生ずる。そして、第１・第２補助突起21, 22を、夫々、第１・第２接触平坦面部１，２に軽く接触させるように、この第１・第２接触平坦面部１，２の相互間隔寸法Ｃを予め設定しておく。この図２に示した捩れ弾性変形の状態は、一対の第１・第２接触平坦面部１，２が相互に分離すれば、図１に示した元の状態───自由状態姿勢───に復元する。
【００２０】
そして、図２に於て、矢印Ｐで示したように、内径側圧力作用時に、第１接触平坦面１に第１補助突起21が当接すると同時に、第２接触平坦面部２に第２補助突起22が当接し、過大捩れ弾性変形を防ぎ、第２接触凸部12が第２接触平坦面部２から遊離し（浮き上り）、図６（Ｂ）で既に述べた矢印Ｇ方向の流体洩れ（ブローバイ）を防止できる。
【００２１】
要するに本発明に係る金属シールＳでは、相手部材（取付部材）７，８の押圧力Ｆ₁ ，Ｆ₂ を、巧妙に、中間基部３を中心に回転する───倒れる───捩れ弾性変形によって、柔軟に受け止め、かつ、第１・第２補助突起21, 22を、夫々、相手部材（取付部材）７，８に軽く接触させて（図６に矢印Ｇで示した）流体洩れ・ブローバイを防止し、金属シールＳと第１・第２接触平坦面部１，２との接触面圧（当接面圧）を常に小さく保って、金属シールＳ及び第１・第２接触平坦面部１，２が局部的に塑性変形したり、損傷を受けることを、有効に防止できる。
【００２２】
ところで、図１と図２に示した実施の形態のものは、外径側圧力作用時にも有効であり、いわゆる内圧用と外圧用の両方に使用できる形状である。つまり、図２に於て、外径側から圧力流体が作用すれば、第２補助突起22と第２接触平坦面部２との当接によって、金属シールＳ全体の捩りは阻止され、第１接触凸部11と第１接触平坦面部１との分離が防がれて、そこからの流体洩れが防止できる。
【００２３】
次に、図３に示す他の実施の形態について説明する。この図３は既述の実施の形態を示す図２に代わる装着圧縮状態の断面図である。この図３に示した金属シールＳは、図２と図１に示した金属シールＳの第２補助突起22を省略した構成であって、それ以外は同一符号は同様の構成であるので重複説明を省略する。
この図３の金属シールＳは、内径側圧力作用時に、第１接触平坦面部１に当接して過大捩れ弾性変形を防ぐ第１補助突起21のみを外径寄りに有する形状である。即ち、内径側に圧力（矢印Ｐ参照）が作用した際に、図６（Ｂ）のように、矢印Ｚ方向に第２接触凸部37───図３の第２接触凸部12───が浮き上ることを防ぎ、矢印Ｇ方向への流体洩れを防止する内圧用である。
【００２４】
次に、図４に示す別の実施の形態について説明する。この図４は既述の図２に代わる装着圧縮状態の断面図であり、この図４のものは、図２と図１に示した金属シールＳの第１補助突起21を省略した構成であって、それ以外は同一符号は同様の構成であるので、重複説明を省略する。
この図４の金属シールＳは、外径側圧力作用時に、第２接触平坦面部２に当接して過大捩れ弾性変形を防ぐ第２補助突起22のみを内径寄りに有する形状である。即ち、外径側に圧力（矢印Ｐ参照）が作用した際に、第１接触凸部11が第１接触平坦面部１から浮き上ることを防ぎ、その接触部（密封部）から、流体が内径方向へ洩れる（ブローバイする）ことを、防止する。つまり、外圧用の金属シールを示す。
【００２５】
図５の実線は比較例を示す断面図であって、点線は本発明の図１の場合を比較のために付記した断面図である。即ち、本発明の金属シールＳのように第１・第２補助突起21, 22を設けない場合で、図２で述べたと同様の浮き上り防止及び流体洩れ防止作用を得るには、中間基部の厚さ寸法Ｔを実線のように増加せねばならない。このように大きな厚さ寸法Ｔでは、図２で示した押圧力Ｆ₁ ，Ｆ₂ が、極端に増大する。つまり、低締付力という本発明に係る金属シールＳの利点が無くなることが分かる。言い換えれば、この図５から、本発明に係る金属シールＳは、低締付力───押圧力Ｆ₁ ，Ｆ₂ が小さい───という利点を、そのまま残しつつ、図６（Ｂ）で述べた浮上り及び流体洩れを、防止している、優れた金属シールであるといえる。
【００２６】
なお、本発明に係る金属シールＳでは、補助突起21, 22によって、取付部材７，８の相互間隔寸法Ｃの調整が可能となり、余剰な変形を抑えることができ、クリープ変形（捩り変形）を減少乃至防止できる。つまり、補助突起21, 22が無い場合には、金属シールが大きい締付力で捩り変形の状態を長期間保つと、永久変形───クリープ変形───を発生してしまうが、本発明では、このような永久変形を防止できる。
【００２７】
このように、本発明に係る金属シールＳは、高圧環境下でも十分なシール性（密封性）を、長期間、安定して発揮できる。また、相手部材（取付部材）７，８に、過大捩り防止のために金属シールＳの一部に当接する段差加工等も、不要である。
また、自由状態で、中間基部３が第１・第２接触平坦面部１，２と傾斜方向として、大きな回転（捩り）を可能としたり、また、端面５，６を凸曲面状、若しくは、凹曲面状とすることも可能である。また、第１・第２接触凸部11, 12を多角形状とすることも自由である。
【００２８】
上述の図示の実施の形態によれば、横断面形状が直線部が多く、切削加工も容易かつ安価でありメタルＯリングでは加工が難しく高価であるような小さなサイズにも、十分対応できる。本金属シールＳは横断面形状がブロック型でズングリしているにかかわらず、倒れ（回転）による捩れ弾性変形等を複合的に行わせて、低締付力にて十分な密封性（シール性能）を発揮する。このような低締付力を活用して、従来のゴム製Ｏリングに代わるシール材として、高温や低温やプラズマ照射やオゾン雰囲気等の従来のＯリングでは適用できない過酷な条件下での適用が可能となる。
なお、材質としてＳＵＳ３１６Ｌダブルメルトは、カーボンなどの不純物が少なく、清浄度が要求される半導体製造装置として好適である。
【００２９】
本金属シールＳの表面について説明すると、 (ｉ) 銀、金、銅、すず等のメッキ、 (ii) ＰＴＦＥ、ＦＥＰ等の各種樹脂被覆（コーティング）、(iii) 各種ゴム材料の被覆（コーティング）、 (iv) 超研磨仕上げ、 (ｖ) 切削又は研削加工又はプレス加工のまま、のいずれとするも自由である。また、被密封流体としては、上記表面被覆の有無及び材質にもよるが、真空、各種ガス（ＣＯ₂ ，Ｈ₂ ，Ｏ₂ ，ＮＨ₃ ，Ｈ₂ Ｏ等）、各種液体（Ｈ₂ Ｏ，Ｈ₂ ＳＯ₄ ，ＨＣｌ等）のものに適用できる。いずれにせよ、本金属シールＳは、低締付力、及び、大きな弾性的復元量、取扱いの容易性、小部品点数、製作の容易性と安価である点で、優れたシールである。従って、装着される相手部材（フランジ等）７，８がセラミックのように脆い材質やアルミニウム等の軟らかい材質のものにも適用可能であり、また、半導体製造装置のようにプラズマやオゾン等が照射される部位にも適用でき、低温から高温までの広い温度領域にも対応できる。そして、潰しが利いて、広いセット高さ（符号Ｃ参照）の範囲で十分なシール性（密封性）を発揮するので、装着される相手部材（フランジ等）７，８の寸法精度や公差が粗くとも適用でき、深い溝でも浅い溝でも、共通の金属シールＳで対応可能となる場合もある。さらに、上下反転使用によって、長寿命化も図ることが容易である。
【００３０】
また、第１・第２接触凸部11，12を、図示の実施の形態のように、半円形乃至半楕円形とすれば、中間基部３を中心に回転して（倒れて）、捩れ弾性変形する場合、第１・第２接触凸部11, 12は、広いセット高さの範囲で、常に安定して第１・第２平坦面部１，２に接触しつつ、全体にゆっくりと姿勢を変化させるので、優れた密封性能（シール性能）を備える。そして、反対側の端面５，６に突設した補助突起22, 21によって、流体圧力Ｐが高い環境下でもブローバイ等の流体洩れが防止できて、高圧環境下でも優れた密封性能（シール性能）を確保できる。
【００３１】
【発明の効果】
本発明は、上述の構成により次のような著大な効果を奏する。
（請求項１，２，３によれば、）装着圧縮状態にて全体に捩れ弾性変形を生ずるように構成したので、低締付力で使用でき、取付部材（フランジ等）７，８が脆い材質や軟らかい材質にも適用できる。
また、金属Ｏリングでは制作が困難な外形寸法が10mm未満の小型のシールとしても、比較的安価に制作可能なため、実用上優れた金属シールである。また、平坦面１，２の損傷も減少できる。
しかも、このような多くの利点を有しながら、高圧環境下でもブローバイ等の流体洩れを、補助突起21及び／又は補助突起22によって、防止できる。さらに、補助突起21及び／又は補助突起22によって、高圧、及び、低圧（真空）に於て長期使用期間後もクリープ変形を起こさず、長期間、優れた密封性能を維持できる。
（請求項２によれば、）内圧用と外圧用に兼用できる。
【図面の簡単な説明】
【図１】本発明の実施の一形態を示す自由状態の断面正面図である。
【図２】作用説明を兼ねた要部断面図である。
【図３】他の実施の形態を示す要部断面図である。
【図４】別の実施の形態を示す要部断面図である。
【図５】比較例と本発明の実施の形態とを比較対照して説明する断面図である。
【図６】本発明者等が既に出願した発明に係る金属シールを説明する要部断面図である。
【符号の説明】
１第１接触平坦面部
２第２接触平坦面部
３中間基部
11 第１接触凸部
12 第２接触凸部
21 第１補助突起
22 第２補助突起
Ｓ金属シール[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal seal.
[0002]
[Prior art]
Conventionally, various materials such as rubber and resin have been used as a seal for a fixing flange of vacuum or internal pressure / external pressure. In particular, metal seals are often used under harsh conditions such as high vacuum / high pressure internal or external pressure, high / low temperature, and application to corrosive fluids.
[0003]
[Problems to be solved by the invention]
However, this metal seal has the following problems. That is, the conventional metal seal generally has a high clamping force, and therefore the thickness of the flange or the like as the mating member (seal mounting member) must be increased, resulting in problems such as an increase in the weight of the apparatus and an increase in volume (space). Occurs.
Conventionally, an elliptical or circular metal seal has been used (not shown), but such an elliptical or circular metal seal is pressed between a pair of flat surfaces parallel to each other. When installed, the plastic seal is locally plastically deformed at the press-contact seal with the flat surface, damaging the flat surface--that is, the mating member such as the flange--and reusing the mating member such as the flange (repeatedly) Use). In addition, high maintenance costs and maintenance time are required at the time of dismantling for maintenance and inspection.
[0004]
The reason why the above-mentioned metal seal having an oval or circular cross section damages the flat surface of the mating member is that it can hardly be elastically deformed due to the rigidity of the metal seal, and the pair of flat surfaces are mutually This is because it receives the tightening force in the direction of approaching as it is, and locally undergoes plastic deformation (crushing).
In short, it is easy to produce with a conventional metal seal, all the conditions that the tightening force is small, the elastic recovery amount is large, and the mating member (flat surface) is not locally crushed (does not damage). Nothing was known that could satisfy
[0005]
Therefore, the present inventors have proposed a metal seal 30 having a cross-sectional shape as illustrated in FIG. 6 in Japanese Patent Application No. 2002-211097. That is, the metal seal 30 is interposed between a first flat surface portion 31 and a second flat surface portion 32 that are parallel to each other, and is generally annular, and has an intermediate base portion 33 having a rectangular cross section and a first flat surface portion. A semicircular first contact convex portion 36 near the inner diameter abutting 31 and a semicircular second contact convex portion 37 near the outer diameter abutting the second flat surface portion 32, and in a compression state In the state of use, torsional elastic deformation occurs around the intermediate base 33 by the pressing forces F ₁ and F ₂ received from the first and second flat surface portions 31 and 32 that are close to each other, and the elasticity associated with the torsional elastic deformation. by repulsion, the first contact protrusions 36 and crimp-pressed against the first flat surface section 31 and second contact protrusions 37 contact crimp-pressure to the second flat surface section 32, the sealing (seal) action It's something that you can enjoy.
[0006]
As shown in FIG. 6, a metal seal with a small tightening force (see arrows F ₁ and F ₂ ) and an excellent resilience has been proposed. With the above pressure, the second contact convex portion 37 is lifted from the second flat surface portion 32 in the direction of arrow Z in FIG. 6B, and there is a risk of fluid leakage (blow-by) in the direction of arrow G. However, it became clear as a result of subsequent examinations of prototypes by the present inventors.
That is, as shown in FIG. 6 (B), when a high fluid pressure P acts on the metal seal 30, the metal seal 30 undergoing torsional elastic deformation with relatively small tightening forces (pressing forces) F ₁ and F ₂ As shown by the two-dot chain line from the solid line shown in FIG. 6B, a phenomenon of easily rising in the arrow Z direction occurs, and fluid leakage (blow-by) occurs in the arrow G direction.
[0007]
The object of the present invention is to have a small tightening force (although it is a metal seal), to have excellent resilience, to reduce the thickness of the flange as a mating member, to reduce the weight and size of the device, and to achieve high pressure An object of the present invention is to provide a metal seal that can effectively prevent fluid leakage such as blow-by during operation and exhibits excellent sealing performance.
[0008]
[Means for Solving the Problems]
In view of the above, the present invention provides a metal ring that is interposed between the first contact flat surface portion and the second contact flat surface portion that are parallel to each other. A first contact convex portion near the inner diameter that contacts the second contact convex portion closer to the outer diameter that contacts the second contact flat surface portion, and receives from the first and second flat surface portions in a mounted compression state. A first portion having a small triangular cross section that is configured to cause torsional elastic deformation around the intermediate base portion by a pressing force and that prevents excessive torsional elastic deformation by contacting the first contact flat surface portion when the inner diameter side pressure is applied. An auxiliary projection is provided near the outer diameter.
[0009]
Further, in the whole annular metal seal interposed between the first contact flat surface portion and the second contact flat surface portion parallel to each other, the intermediate base portion and the inner diameter contact portion that contacts the first contact flat surface portion are closer to each other. A first contact convex portion and a second contact convex portion close to the outer diameter that abuts on the second contact flat surface portion, and the pressing force received from the first and second flat surface portions in the mounted compression state First and second cross-sectional small triangles configured to cause torsional elastic deformation around the intermediate base and to prevent excessive torsional elastic deformation by abutting against the first and second contact flat surface portions respectively when pressure is applied . having second auxiliary protrusion outside径寄Ri-inner diameter closer.
[0010]
Further, in the whole annular metal seal interposed between the first contact flat surface portion and the second contact flat surface portion parallel to each other, the intermediate base portion and the inner diameter contact portion that contacts the first contact flat surface portion are closer to each other. A first contact convex portion and a second contact convex portion close to the outer diameter that abuts on the second contact flat surface portion, and the pressing force received from the first and second flat surface portions in the mounted compression state A second auxiliary protrusion having a small triangular cross section configured to cause torsional elastic deformation around the intermediate base and to prevent excessive torsional elastic deformation by abutting against the second contact flat surface portion when the outer diameter side pressure is applied; Near the inner diameter.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 and 2 show an embodiment of a metal seal (metal seal) S according to the present invention, FIG. 1 is a sectional front view in a free state (unmounted state), and FIG. FIG. 4 is a cross-sectional explanatory diagram of a main part showing a mounted compression state.
[0012]
The metal seal S is made of stainless steel, spring steel, or other metal, and is manufactured by machining such as cutting or grinding.
The metal seal S is interposed between the first contact flat surface portion 1 and the second contact flat surface portion 2 that are parallel to each other, and the whole is a ring, such as a circle, an ellipse, an ellipse, or a substantially rectangle. is there. The cross-sectional shape will be described. The intermediate base portion 3 has a substantially rectangular shape (rectangular shape), and the first contact convex portion 11 and the second contact convex portion 12 have a substantially semicircular shape. The first contact convex portion 11 is disposed near the inner diameter of the intermediate base portion 3, and the second contact convex portion 12 is disposed near the outer diameter of the intermediate base portion 3.
In the mounted state, the first contact convex portion 11 near the inner diameter abuts on the first contact flat surface portion 1, and the second contact convex portion 12 near the outer diameter abuts on the second contact flat surface portion 2.
[0013]
In the right half of FIG. 1 and FIG. 2, the boundary line between the intermediate base 3 and the first and second contact convex portions 11 and 12 is indicated by a two-dot chain line. Although not shown in the drawings, in the uncompressed state, the upper and lower long side end surfaces 5 and 6 of the intermediate base 3 are the first and second of the attachment members 7 and 8 such as flanges. The contact flat surfaces 1 and 2 are in a parallel state. Although not shown, one or both of the upper and lower long-side end surfaces 5 and 6 may be in a state (inclined) that is not parallel to the first and second contact flat surfaces 1 and 2. Thereafter, when the attachment members (mating members) 7 and 8 approach each other, the attachment compression state shown in FIG. 2 is obtained. In the mounted compression state of FIG. 2, torsional elastic deformation is generated around the intermediate base 3 by the pressing forces F ₁ and F ₂ received from the first and second flat surface portions 1 and ₂ .
[0014]
Reference numeral 21 denotes a small triangular first auxiliary projection, which is disposed near the outer diameter of the end surface 5 (upper side of the drawing) of the intermediate base 3, and is acted upon by the fluid pressure P as shown in FIG. At this time (at the time of pressure action), the first auxiliary projection 21 near the outer diameter comes into contact with the first contact flat surface portion 1 to prevent excessive torsional elastic deformation.
Reference numeral 22 denotes a second auxiliary projection having a small triangular shape, which is disposed near the inner diameter of the end surface 6 (lower side of the drawing) of the intermediate base 3 and is operated when pressure is applied as shown in FIG. 22 abuts against the second contact flat surface portion 2 to prevent excessive torsional elastic deformation at the same time. When the fluid pressure P is high, the effect of preventing excessive torsional elastic deformation by the first auxiliary protrusion 21 and the second auxiliary protrusion 22 is particularly exerted. However, even when the fluid pressure P is low (or vacuum), the first and second auxiliary protrusions 21 and 22 can prevent the metal seal S itself from being deformed by a creep phenomenon.
[0015]
In the cross section, a first contact protrusion 11 is disposed near the inner diameter of the one end surface 5 of the intermediate base 3, and a first auxiliary protrusion 21 is disposed near the outer diameter so as to protrude. The height dimension (projection dimension) H ₂₁ of the protrusion ₂₁ is set smaller than the height dimension (projection dimension) H _{11 of} the first contact projection 11. That is, H ₂₁ <H ₁₁ .
On the other hand, the second contact protrusion 12 is disposed near the outer diameter of the other end surface 6 of the intermediate base 3 and the second auxiliary protrusion 22 is disposed so as to protrude toward the inner diameter. The height dimension (protrusion dimension) H ₂₂ is set smaller than the height dimension (protrusion dimension) H _{12 of} the second contact convex portion 12. That is, H ₂₂ <H ₁₂ .
[0016]
Thus, with respect to the intermediate base portion 3 having a rectangular cross section, the first contact convex portion is displaced in the inner diameter side and the outer diameter side (in the radial direction) and in a direction opposite to the axial center L direction. 11 and the 2nd contact convex part 12 are protrudingly provided. In addition, the first auxiliary projection 21 and the second auxiliary projection 22 are simultaneously shifted in the inner diameter side and the outer diameter side (in the radial direction) with respect to the intermediate base portion 3 having a rectangular cross section, and the axial center. Project in a direction opposite to the L direction. In addition, the short side 9 (which forms the inner peripheral surface) of the intermediate base portion 3 having a rectangular cross section and the first contact convex portion 11 having a substantially semicircular shape are continuous (no step) and have a small triangular cross section. The second auxiliary projection 22 is formed continuously from the short side 9 in a fold line shape, and shows a case where the second auxiliary projection 22 is disposed at a corner of the intermediate base 3 having a rectangular cross section (no step).
[0017]
Further, the other short side 10 (which forms the outer peripheral surface) of the intermediate base portion 3 having a rectangular cross section and the substantially semicircular second contact convex portion 12 are continuous (no step) and have a small triangular shape. The first auxiliary protrusions 21 are continuously formed in a bent shape from the short side 10 and are disposed at the corners of the intermediate base 3 having a rectangular section (no step). Thus, it can be said that the first auxiliary protrusion 21 and the second auxiliary protrusion 22 are in point symmetry with respect to the center of gravity of the intermediate base 3. Further, it can be said that the first contact convex portion 11 and the second contact convex portion 12 described above are in a point symmetrical position with respect to the center of gravity.
[0018]
In the embodiment of FIGS. 1 and 2, the positions of the first and second auxiliary projections 21 and 22 are not the corner positions that are continuous with the short side 9 or the short side 10 in a bent line shape, but the middle angle. It is also free to move from the angular position of the base 3 slightly inward and to project from the end faces 5 and 6 (not shown ).
[0019]
1 is mounted between the first and second contact flat surface portions 1 and 2 so that the first and second contact flat surface portions 1 and 2 are close to each other. Then, when approaching the mounted compression state shown in FIG. 2, the metal seal S is brought into contact with the intermediate base portion 3 (the center of gravity of the intermediate base portion 3) by the pressing forces F ₁ and F ₂ received from the pair of first and second contact flat surface portions 1 and ₂ . ) And torsional elastic deformation occurs. Then, the first and second auxiliary projections 21 and 22 are spaced apart from each other so that the first and second auxiliary projections 21 and 22 are in light contact with the first and second contact flat surfaces 1 and 2, respectively. C is set in advance. The state of torsional elastic deformation shown in FIG. 2 is the original state shown in FIG. 1 when the pair of first and second contact flat surface portions 1 and 2 are separated from each other. Restore to.
[0020]
In FIG. 2, as indicated by an arrow P, when the inner diameter side pressure is applied, the first auxiliary projection 21 comes into contact with the first contact flat surface 1, and at the same time, the second contact flat surface portion 2 has the second auxiliary. The protrusions 22 come into contact with each other to prevent excessive torsional elastic deformation, and the second contact convex portion 12 is released (raised) from the second contact flat surface portion 2, and the fluid leakage in the direction indicated by the arrow G already described with reference to FIG. Blow-by) can be prevented.
[0021]
In short, in the metal seal S according to the present invention, the pressing forces F ₁ and F ₂ of the mating members (mounting members) 7 and 8 are skillfully rotated about the intermediate base 3 ─── collapsed ── torsional elastic deformation Thus, the first and second auxiliary projections 21 and 22 are lightly brought into contact with the mating members (mounting members) 7 and 8 (indicated by an arrow G in FIG. 6), and fluid leakage and blow-by are received. The contact surface pressure (contact surface pressure) between the metal seal S and the first and second contact flat surface portions 1 and 2 is always kept small, and the metal seal S and the first and second contact flat surface portions 1 and 2 are maintained. It is possible to effectively prevent 2 from being locally plastically deformed or damaged.
[0022]
By the way, the embodiment shown in FIG. 1 and FIG. 2 is effective at the time of acting on the outer diameter side pressure, and has a shape that can be used for both internal pressure and external pressure. That is, in FIG. 2, when the pressure fluid acts from the outer diameter side, the torsion of the entire metal seal S is prevented by the contact between the second auxiliary protrusion 22 and the second contact flat surface portion 2, and the first contact is made. Separation of the convex portion 11 and the first contact flat surface portion 1 is prevented, and fluid leakage therefrom can be prevented.
[0023]
Next, another embodiment shown in FIG. 3 will be described. FIG. 3 is a cross-sectional view of a mounted compression state in place of FIG. 2 showing the embodiment described above. The metal seal S shown in FIG. 3 has a configuration in which the second auxiliary protrusions 22 of the metal seal S shown in FIGS. 2 and 1 are omitted, and the other components are the same as those in FIG. Is omitted.
The metal seal S of FIG. 3 has a shape having only the first auxiliary projection 21 closer to the outer diameter to abut against the first contact flat surface portion 1 and prevent excessive torsional elastic deformation when the inner diameter side pressure is applied. That is, when pressure (see arrow P) acts on the inner diameter side, as shown in FIG. 6B, the second contact projection 37 in the direction of arrow Z—the second contact projection 12 in FIG. It is for internal pressure that prevents ─ from floating and prevents fluid leakage in the direction of arrow G.
[0024]
Next, another embodiment shown in FIG. 4 will be described. FIG. 4 is a cross-sectional view of a compression state in place of the above-described FIG. 2. FIG. 4 is a configuration in which the first auxiliary projection 21 of the metal seal S shown in FIGS. 2 and 1 is omitted. In other respects, the same reference numerals have the same configuration, and the duplicate description is omitted.
The metal seal S of FIG. 4 has a shape having only the second auxiliary projection 22 close to the inner diameter so as to abut against the second contact flat surface portion 2 to prevent excessive torsional elastic deformation when the outer diameter side pressure is applied. That is, when pressure (see arrow P) acts on the outer diameter side, the first contact convex portion 11 is prevented from floating from the first contact flat surface portion 1, and the fluid flows into the inner diameter from the contact portion (sealing portion). Prevent leakage (blow-by) in the direction. That is, a metal seal for external pressure is shown.
[0025]
The solid line in FIG. 5 is a cross-sectional view showing a comparative example, and the dotted line is a cross-sectional view in which the case of FIG. 1 of the present invention is added for comparison. That is, when the first and second auxiliary projections 21 and 22 are not provided as in the case of the metal seal S of the present invention, in order to obtain the same lift prevention and fluid leakage prevention action as described in FIG. The thickness dimension T must be increased as shown by the solid line. With such a large thickness dimension T, the pressing forces F ₁ and F ₂ shown in FIG. 2 increase extremely. That is, it can be seen that the advantage of the metal seal S according to the present invention of low tightening force is lost. In other words, from FIG. 5, the metal seal S according to the present invention has the advantage that the low tightening force—the pressing forces F ₁ and F ₂ are small—is retained in FIG. 6B. It can be said that it is an excellent metal seal that prevents the above-described lifting and fluid leakage.
[0026]
In the metal seal S according to the present invention, it is possible to adjust the distance C between the mounting members 7 and 8 by the auxiliary projections 21 and 22, and it is possible to suppress excessive deformation and to perform creep deformation (torsional deformation). It can be reduced or prevented. In other words, in the absence of the auxiliary protrusions 21 and 22, if the metal seal is kept in a torsional deformation state with a large tightening force for a long period of time, permanent deformation --- creep deformation-will occur. Then, such permanent deformation can be prevented.
[0027]
As described above, the metal seal S according to the present invention can stably exhibit a sufficient sealing performance (sealing performance) for a long period of time even under a high pressure environment. Further, it is not necessary to process the mating members (mounting members) 7 and 8 so as to contact a part of the metal seal S to prevent excessive twisting.
Further, in the free state, the intermediate base 3 can be rotated (twisted) with the first and second contact flat surface portions 1 and 2 in an inclined direction, and the end surfaces 5 and 6 are convex curved or concave. It may be curved. Further, the first and second contact protrusions 11 and 12 can be polygonal.
[0028]
According to the illustrated embodiment described above, the cross-sectional shape has many straight portions, cutting is easy and inexpensive, and it can sufficiently cope with a small size that is difficult and expensive with a metal O-ring. This metal seal S has sufficient blockiness (sealing performance) with low tightening force by complexly performing torsional elastic deformation due to tilting (rotation), regardless of whether the cross-sectional shape is block-shaped and splayed. ). Utilizing such a low tightening force, it can be used as a sealing material in place of conventional rubber O-rings under severe conditions that cannot be applied with conventional O-rings such as high temperature, low temperature, plasma irradiation and ozone atmosphere. It becomes possible.
As a material, SUS316L double melt is suitable as a semiconductor manufacturing apparatus that requires few impurities such as carbon and requires high cleanliness.
[0029]
The surface of the metal seal S will be described. (I) Plating of silver, gold, copper, tin, etc. (ii) Various resin coatings (coating) such as PTFE, FEP, (iii) Coating of various rubber materials (coating) (Iv) Super polished finish, (v) Cutting, grinding, or pressing can be left free. Further, as the fluid to be sealed, depending on the presence or absence of the surface coating and the material, vacuum, various gases (CO ₂ , H ₂ , O ₂ , NH ₃ , H ₂ O, etc.), various liquids (H ₂ O, H ₂ SO ₄ , HCl, etc.). In any case, the present metal seal S is an excellent seal in that it has a low clamping force, a large amount of elastic restoration, ease of handling, the number of small parts, ease of manufacture, and low cost. Therefore, the mating member (flange, etc.) 7 and 8 to be mounted can be applied to a brittle material such as ceramic or a soft material such as aluminum, and plasma or ozone is irradiated as in a semiconductor manufacturing apparatus. It can also be applied to a part that is applied to a wide temperature range from low temperature to high temperature. And since it is crushed and exhibits sufficient sealing performance (sealing performance) within a wide set height (see symbol C), the dimensional accuracy and tolerances of the mating members (flange etc.) 7 and 8 to be mounted are Even a rough groove can be applied, and a common metal seal S can be used for both deep and shallow grooves. Furthermore, it is easy to extend the life by using upside down.
[0030]
If the first and second contact protrusions 11 and 12 are semicircular or semielliptical as in the illustrated embodiment, they rotate (fall down) about the intermediate base 3 and are twisted elastically. In the case of deformation, the first and second contact protrusions 11 and 12 are in a wide set height range, always in stable contact with the first and second flat surface parts 1 and 2, and slowly taking an overall posture. Since it is changed, it has excellent sealing performance (sealing performance). The auxiliary protrusions 22 and 21 projecting from the opposite end surfaces 5 and 6 can prevent fluid leakage such as blow-by even under high fluid pressure P environment, and have excellent sealing performance (sealing performance) even under high pressure environment. Can be secured.
[0031]
【The invention's effect】
The present invention has the following remarkable effects by the above-described configuration.
(According to claims 1, 2 and 3) Since it is configured so as to cause torsional elastic deformation as a whole in the mounted compression state, it can be used with a low tightening force, and the mounting members (flange, etc.) 7 and 8 are fragile. It can also be applied to materials and soft materials.
In addition, even a small seal with an outer dimension of less than 10 mm, which is difficult to produce with a metal O-ring, can be produced at a relatively low cost, so it is a practically superior metal seal. Further, damage to the flat surfaces 1 and 2 can be reduced.
In addition, fluid leakage such as blow-by can be prevented by the auxiliary protrusions 21 and / or auxiliary protrusions 22 even under a high pressure environment while having such many advantages. Further, the auxiliary protrusion 21 and / or auxiliary protrusion 22 does not cause creep deformation even after a long period of use at high pressure and low pressure (vacuum), and can maintain excellent sealing performance for a long time.
(According to claim 2) It can be used for both internal pressure and external pressure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view in a free state showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a principal part that also serves as an explanation of operation.
FIG. 3 is a cross-sectional view of a main part showing another embodiment.
FIG. 4 is a cross-sectional view of a main part showing another embodiment.
FIG. 5 is a cross-sectional view illustrating a comparative example in comparison with an embodiment of the present invention.
FIG. 6 is a cross-sectional view of an essential part for explaining a metal seal according to an invention already filed by the present inventors.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st contact flat surface part 2 2nd contact flat surface part 3 Intermediate | middle base
11 First contact protrusion
12 Second contact protrusion
21 First auxiliary protrusion
22 Second auxiliary projection S Metal seal

Claims

An intermediate base (3) and the first contact flat surface in a generally annular metal seal interposed between the first contact flat surface portion (1) and the second contact flat surface portion (2) parallel to each other. A first contact convex portion (11) near the inner diameter that abuts against the surface portion (1) and a second contact convex portion (12) near the outer diameter that abuts against the second contact flat surface portion (2). In the compressed state, it is configured to be twisted and elastically deformed around the intermediate base (3) by the pressing force received from the first and second flat surface portions (1) and (2), and at the time of pressure action on the inner diameter side A metal seal comprising a first auxiliary projection (21) having a small triangular cross-section in contact with the first contact flat surface portion (1) to prevent excessive torsional elastic deformation near the outer diameter.

An intermediate base (3) and the first contact flat surface in a generally annular metal seal interposed between the first contact flat surface portion (1) and the second contact flat surface portion (2) parallel to each other. A first contact convex portion (11) near the inner diameter that abuts against the surface portion (1) and a second contact convex portion (12) near the outer diameter that abuts against the second contact flat surface portion (2). In a compressed state, it is configured to be twisted and elastically deformed around the intermediate base portion (3) by the pressing force received from the first and second flat surface portions (1) and (2), and when the pressure is applied, the first 1-second contact flat surface section (1) (2) in each first and second auxiliary projections (21) of the cross section small triangular prevent contact with excessive torsional elastic deformation (22) of the outer径寄Ri-inner diameter closer The metal seal characterized by having in.

An intermediate base (3) and the first contact flat surface in a generally annular metal seal interposed between the first contact flat surface portion (1) and the second contact flat surface portion (2) parallel to each other. A first contact convex portion (11) near the inner diameter that abuts against the surface portion (1) and a second contact convex portion (12) near the outer diameter that abuts against the second contact flat surface portion (2). In the compressed state, it is configured so as to cause torsional elastic deformation around the intermediate base (3) by the pressing force received from the first and second flat surface portions (1) and (2), and the outer diameter side pressure action A metal seal characterized by having a second auxiliary projection (22) having a small triangular cross section close to the inner diameter, which sometimes abuts against the second contact flat surface portion (2) to prevent excessive torsional elastic deformation.