JP2004332882A

JP2004332882A - Butterfly valve equipped with flooding function

Info

Publication number: JP2004332882A
Application number: JP2003132411A
Authority: JP
Inventors: Kenei Ishii; 健睿石井; Keiichi Sato; 敬一佐藤; Akinobu Hourai; 章伸蓬莱
Original assignee: JAPAN WATER WORKS ASSOCIATION; Kubota Corp
Current assignee: JAPAN WATER WORKS ASSOCIATION; Kubota Corp
Priority date: 2003-05-12
Filing date: 2003-05-12
Publication date: 2004-11-25
Anticipated expiration: 2023-05-12
Also published as: JP4266698B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a butterfly valve equipped with a flooding function which can reduce the operational physical force required when opening/closing the valve. <P>SOLUTION: The butterfly valve includes a rubber valve casing seal ring 3 arranged in a valve casing 2, a rotatable valve element 7 which is in sliding contact with the valve casing seal ring 3 at a full closure position, and a pair of disk tail parts 14, 15 attached to the peripheral edge portion of the valve element 7. The disk tail parts 14, 15 each have a spherically curved outer peripheral surface and a water passage hole 16. A plurality of convex portions 19 and concave portions 20 are circumferentially formed on the inner peripheral surface of the valve casing seal ring 3. The convex portions 19 and concave portions 20 are arranged at a partial closure position rather than at the full closure position in the rotating direction of the valve element 7. When the valve element 7 is at the full closure position, the outer peripheral edge of the valve element 7 is in sliding contact with the inner peripheral surface of the valve casing seal ring 3. When the valve element 7 is within a range of a certain small opening degree α, the outer peripheral surfaces of the disk tail parts 14, 15 are in sliding contact with the convex portions 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、充水機能を備えたバタフライ弁に関し、配管への充水時に定流量で流体を供給するバルブの技術に係るものである。
【０００２】
【従来の技術】
従来、充水機能を備えたバタフライ弁としては例えは図１８，図１９に示すように、内面全体に柔軟な弾性スリーブ５１を装着した弁室５２内に、流路軸心５３と直交する回転軸心５４廻りに回転自在な弁体５５が設けられたものがある。この弁体５５は、外周面を球形に形成した一対の弁部片５５ａ，５５ｂを対称に配置した構成を有している。少なくとも一方の弁部片５５ａには、流量制御用の凹溝５６が形成されている。
【０００３】
これによると、図１８に示すように、弁体５５を全閉位置Ｓにした際、弁体５５の外周面が弾性スリーブ５１の内周面に摺接するとともに、凹溝５６が全閉位置Ｓよりも上流側Ａに位置するため、弁室５２内の流路５７が上記弁体５５で全閉される。
【０００４】
また、図１９に示すように、弁体５５を所定の小開度αにした際、弁体５５の外周面が弾性スリーブ５１の内周面に摺接するとともに、凹溝５６が弁体５５の上流側Ａから下流側Ｂへ連通するため、弁室５２内の流体は、弁体５５の上流側Ａから凹溝５６を通って下流側Ｂへと流れる。これにより、小流量で下流側配管に充水される（例えば、特許文献１参照。）。
【０００５】
【特許文献１】
実開昭５９−１０１０５４号公報
【０００６】
【発明が解決しようとする課題】
しかしながら上記の従来形式では、弁体５５を開閉する際、全閉位置Ｓと所定の小開度αとの間の範囲においては、弁体５５の外周面が弾性スリーブ５１の内周面に対して摺動し、この時の弁体５５の外周面と弾性スリーブ５１の内周面との接触面積が広くなるため、摩擦抵抗が増大し、弁体５５の開閉時に大きな操作力を要するといった問題があった。
【０００７】
本発明は、弁体開閉時に要する操作力を軽減することが可能な充水機能を備えたバタフライ弁を提供することを目的とする。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、本第１発明は、弁箱内に内周面に沿って円環状に配置された弾性体からなる弁箱シールリングと、弁棒の軸心周りに回転して全閉位置で弁箱シールリングに摺接する弁体と、開回転方向における弁体の背面側に取付けられた一対のディスクテール部とを有するバタフライ弁であって、上記ディスクテール部は、弁体回転方向において扇状に形成されて弁体の周縁部に設けられ、且つ、球面状に湾曲した外周面を有し、少なくともいずれか片方のディスクテール部に、一端が外周面に開口するとともに他端が弁体の上記背面側に開口する通水孔が形成され、上記弁箱シールリングの内周面に、ディスクテール部の外周面に摺接する凸部が周方向に沿って形成され、上記凸部は全閉位置よりも閉回転方向側に位置しており、弁体が全閉位置にある場合、弁体の外周縁が弁箱シールリングの内周面に摺接し、弁体が所定の小開度の範囲内にある場合、ディスクテール部の外周面が上記凸部に摺接するものである。
【０００９】
これによると、弁体を全閉位置にした場合、弁体の外周縁が弁箱シールリングの内周面に摺接するため、弁箱内の流路が上記弁体で全閉される。この際、弁体の上流側と下流側とは弁体の外周縁と弁箱シールリングの内周面とでシールされている。
【００１０】
また、弁体を所定の小開度にした場合、両ディスクテール部の外周面が弁箱シールリングの凸部に摺接し、通水孔が弁体の上流側と下流側とに連通する。これにより、弁箱内の流体が弁体の上流側から通水孔を通って下流側へ流れ、小流量で下流側配管に充水される。
【００１１】
また、弁体を開閉する際、全閉位置と所定の小開度との間の範囲においては、ディスクテール部の外周面が上記凸部に対して摺動するため、この時のディスクテール部の外周面と弁箱シールリングとの接触面積が縮小される。これにより、摩擦抵抗が減少し、弁体開閉時に要する操作力を軽減することができる。
【００１２】
また、本第２発明は、弁箱内に内周面に沿って円環状に配置された弾性体からなる弁箱シールリングと、弁棒の軸心周りに回転して全閉位置で弁箱シールリングに摺接する弁体と、開回転方向における弁体の背面側に取付けられた一対のディスクテール部とを有するバタフライ弁であって、上記ディスクテール部は、弁体回転方向において扇状に形成されて弁体の周縁部に設けられ、且つ、弁体の小開度時に弁箱シールリングに摺接する球面状に湾曲した外周面を有し、少なくともいずれか片方のディスクテール部に、一端が外周面に開口するとともに他端が弁体の上記背面側に開口する通水孔が形成され、上記弁箱シールリングの内周面は、開閉時に弁体の外周縁が摺接する弁体摺接部分と、ディスクテール部の外周面が摺接するテール摺接部分とを備え、上記テール摺接部分の摩擦係数を薬品処理によって弁体摺接部分の摩擦係数よりも小さくしたものである。
【００１３】
これによると、弁体を全閉位置にした場合、弁体の外周縁が弁箱シールリングの弁体摺接部分に摺接し、弁箱内の流路が上記弁体で全閉される。この際、弁体の上流側と下流側とは弁体の外周縁と弁箱シールリングの弁体摺接部分とでシールされている。
【００１４】
また、弁体を所定の小開度にした場合、両ディスクテール部の外周面が弁箱シールリングのテール摺接部分に摺接し、通水孔が弁体の上流側と下流側とに連通する。これにより、弁箱内の流体が弁体の上流側から通水孔を通って下流側へ流れ、小流量で下流側配管に充水される。
【００１５】
また、弁体を開閉する際、全閉位置と所定の小開度との間の範囲においては、ディスクテール部の外周面が上記テール摺接部分に対して摺動するが、上記テール摺接部分の摩擦係数を薬品処理によって弁体摺接部分の摩擦係数よりも小さくしているため、ディスクテール部の外周面と弁箱シールリングのテール摺接部分との間の摩擦抵抗が減少し、弁体開閉時に要する操作力を軽減することができる。
【００１６】
【発明の実施の形態】
以下、本発明の第１の実施の形態を図１〜図９に基づいて説明する。
図１〜図４に示すように、１はバタフライ弁であり、その弁箱２は両側のポートＰ１，Ｐ２に上流側配管（図示省略）と下流側配管（図示省略）とが接続されている。
【００１７】
上記弁箱２内には、円環状のゴム（弾性体の一例）製の弁箱シールリング３が内周面に沿って配置されている。また、弁箱２内には、流路軸心４に直交する弁棒５の軸心６廻りに回転する開閉自在な弁体７が設けられている。上記弁体７は、円盤状で且つ内部が中空の本体部９と、この本体部９の外周に形成され且つ本体部９よりも薄い板状の周板部１０とで構成されている。
【００１８】
尚、弁棒５は、弁体７に設けられた一対の円筒状のボス部１１に挿通されて一体的に連結され、弁箱２に回転自在に保持されている。また、弁棒５の端部は、弁棒５を回転して弁体７を開閉する手動ハンドルや減速機付きモータ等の駆動装置（図示省略）に連動連結されている。
【００１９】
また、開回転方向Ｃ（すなわち開栓時の回転方向）における弁体７の背面側には、一対のディスクテール部１４，１５が設けられている。これら両ディスクテール部１４，１５はそれぞれ、弁体７の回転方向において扇状に形成されており、上記周板部１０の外周縁部に取付けられ、周板部１０から立ち上がっている。両ディスクテール部１４，１５の外周面はそれぞれ球面状に湾曲している。尚、弁体７を開回転方向Ｃに回転した場合、一方のディスクテール部１４は上流側Ａへ向かって変位するとともに、他方のディスクテール部１５は下流側Ｂへ向かって変位する。
【００２０】
上記両ディスクテール部１４，１５にはそれぞれ、一端が外周面に開口するとともに他端が弁体７の上記背面側に開口する通水孔１６が形成されている。上記通水孔１６は、弁体７の周方向に沿って細長い長円状であり、上記周板部１０に隣接する１箇所に形成されている。
【００２１】
上記弁箱シールリング３は、弁棒５の箇所で２分割された一対の半円形のシール片３ａ，３ｂによって構成され、弁箱２の内周面に形成された取付溝１８に嵌め込まれて装着されている。
【００２２】
上記一方のシール片３ａの内周面１７は下流側Ｂほど流路軸心４に向かって内側に傾斜しており、他方のシール片３ｂの内周面１７は上流側Ａほど流路軸心４に向かって内側に傾斜している。図４，図５に示すように、弁箱シールリング３の内周面１７には、ゴム（弾性体の一例）製の複数の山形状の凸部１９と谷形状の凹部２０とが交互に全周にわたって形成されている。上記凸部１９と凹部２０とは両シール片３ａ，３ｂの内周面１７にそれぞれ複数条の溝を平行に形成することによって得られ、各凸部１９の頂部は、両シール片３ａ，３ｂの内周面１７とほぼ面一であり、両ディスクテール部１４，１５の外周面に摺接する。
【００２３】
図４に示すように、上記凸部１９と凹部２０とは全閉位置Ｓよりも閉回転方向Ｄ（すなわち閉栓時の回転方向）の側（すなわち一方のシール片３ａにおいては下流側Ｂ、他方のシール片３ｂにおいては上流側Ａ）に位置している。尚、図４，図６に示すように、弁体７が全閉位置Ｓにある場合、周板部１０の外周縁が弁箱シールリング３（すなわち両シール片３ａ，３ｂ）の内周面１７に摺接する。また、図７〜図９に示すように、弁体７が所定の小開度αの範囲内にある場合、両ディスクテール部１４，１５の外周面が上記凸部１９に摺接する。
【００２４】
以下、上記構成における作用を説明する。
図４の実線で示すように、弁体７を全閉位置Ｓにした場合、図６に示すように、周板部１０の外周縁が弁箱シールリング３（すなわち、両シール片３ａ，３ｂ）の内周面１７に摺接するため、弁箱２内の流路２２が上記弁体７で全閉される。この際、弁体７の上流側Ａと下流側Ｂとは周板部１０の外周縁と弁箱シールリング３の内周面１７とでシールされている。
【００２５】
また、図７に示すように弁体７を所定の小開度αにした場合、図８，図９に示すように、両ディスクテール部１４，１５の外周面が弁箱シールリング３の凸部１９に摺接し、通水孔１６が弁体７の上流側Ａと下流側Ｂとに連通する。これにより、弁箱２内の水（上水，工水，農水等）が弁体７の上流側Ａから通水孔１６を通って下流側Ｂへ流れ、小流量で下流側配管に充水される。
【００２６】
また、弁体７を開閉する際、全閉位置Ｓと所定の小開度αとの間の範囲においては、両ディスクテール部１４，１５の外周面は、各凹部２０には摺接せず、上記各凸部１９に対してのみ摺動するため、この時のディスクテール部１４，１５の外周面と弁箱シールリング３との接触面積が縮小される。これにより、摩擦抵抗が減少し、弁体７の開閉時に要する操作力を軽減することができる。また、この際、図８に示すように弁体７が開回転方向Ｃに回転していれば、各凸部１９は開回転方向Ｃ側の各凹部２０に倒れて逃げ、図９に示すように弁体７が閉回転方向Ｄに回転していれば、各凸部１９は閉回転方向Ｄ側の各凹部２０に倒れて逃げるため、各凸部１９が過度にディスクテール部１４，１５の外周面に押圧されることはなく、弁体７の開閉時の操作がより一層スムーズに行える。
【００２７】
尚、図４の仮想線で示すように、弁体７を全閉位置Ｓから開回転方向Ｃへ約９０°回転して全開にした場合、弁体７は流路軸心４上に位置し、弁体７および両ディスクテール部１４，１５は弁箱シールリング３から離間した状態になる。
【００２８】
上記第１の実施の形態では、凸部１９と凹部２０とを、弁箱シールリング３の内周面１７に全周にわたって形成しているが、全周ではなく、周方向に部分的に形成してもよい。また、弾性体の一例であるゴムによって弁箱シールリング３と凸部１９と凹部２０とを形成しているが、ゴム以外の弾性を有する柔軟な材質を用いてもよい。
【００２９】
上記第１の実施の形態では、図５に示すように、凸部１９と凹部２０とをそれそれ複数ずつ形成したが、単数ずつ形成してもよい。
次に、本発明の第２の実施の形態を図１０〜図１３に基づいて説明する。
【００３０】
弁箱シールリング３の内周面１７には、ゴム（弾性体の一例）製の山形状の凸部３０が全周にわたって形成されている。上記凸部３０は両シール片３ａ，３ｂの内周面１７から流路軸心４に向かって内側へ突出しており、両ディスクテール部１４，１５の外周面に摺接する。
【００３１】
上記凸部３０は、両シール片３ａ，３ｂに単数本形成されており、全閉位置Ｓよりも閉回転方向Ｄ（すなわち閉栓時の回転方向）の側（すなわち一方のシール片３ａにおいては下流側Ｂ、他方のシール片３ｂにおいては上流側Ａ）に位置している。尚、図１１に示すように、弁体７が全閉位置Ｓにある場合、周板部１０の外周縁が弁箱シールリング３（すなわち両シール片３ａ，３ｂ）の内周面１７に摺接する。また、図１２，図１３に示すように、弁体７が所定の小開度αの範囲内にある場合、両ディスクテール部１４，１５の外周面が上記凸部３０に摺接する。
【００３２】
以下、上記構成における作用を説明する。
図１１に示すように、弁体７を全閉位置Ｓにした場合、周板部１０の外周縁が弁箱シールリング３（すなわち、両シール片３ａ，３ｂ）の内周面１７に摺接するため、弁箱２内の流路２２が上記弁体７で全閉される。この際、弁体７の上流側Ａと下流側Ｂとは周板部１０の外周縁と弁箱シールリング３の内周面１７とでシールされている。
【００３３】
また、図１２，図１３に示すように、弁体７を所定の小開度αにした場合、両ディスクテール部１４，１５の外周面が弁箱シールリング３の凸部３０に摺接し、通水孔１６が弁体７の上流側Ａと下流側Ｂとに連通する。これにより、弁箱２内の水（上水，工水，農水等）が弁体７の上流側Ａから通水孔１６を通って下流側Ｂへ流れ、小流量で下流側配管に充水される。
【００３４】
また、弁体７を開閉する際、図１２，図１３に示すように、全閉位置Ｓと所定の小開度αとの間の範囲においては、両ディスクテール部１４，１５の外周面は、弁箱シールリング３の内周面１７には摺接せず、上記凸部３０に対してのみ摺動するため、この時のディスクテール部１４，１５の外周面と弁箱シールリング３との接触面積が縮小される。これにより、摩擦抵抗が減少し、弁体７の開閉時に要する操作力を軽減することができる。また、この際、図１２に示すように弁体７が開回転方向Ｃに回転していれば、凸部３０は上流側Ａに倒れて逃げ、図１３に示すように弁体７が閉回転方向Ｄに回転していれば、凸部３０は下流側Ｂに倒れて逃げるため、上記凸部３０が過度にディスクテール部１４，１５の外周面に押圧されることはなく、弁体７の開閉時の操作がより一層スムーズに行える。
【００３５】
上記第２の実施の形態では、凸部３０を、弁箱シールリング３の内周面１７に全周にわたって形成しているが、全周ではなく、周方向に部分的に形成してもよい。また、弾性体の一例であるゴムによって弁箱シールリング３と凸部３０とを形成しているが、ゴム以外の弾性を有する柔軟な材質を用いてもよい。
【００３６】
次に、本発明の第３の実施の形態を図１４〜図１６に基づいて説明する。
両ディスクテール部１４，１５の外周面はそれぞれ、球面状に湾曲しており、図１６に示すように、弁体７が所定の小開度αの範囲内にある時、弁箱シールリング３に摺接する。
【００３７】
上記弁箱シールリング３は、弁棒５の箇所で２分割された一対の半円形のシール片３ａ，３ｂによって構成され、弁箱２の内周面に形成された取付溝１８に嵌め込まれて装着されている。
【００３８】
上記一方のシール片３ａの内周面１７は下流側Ｂほど流路軸心４に向かって内側に傾斜しており、他方のシール片３ｂの内周面１７は上流側Ａほど流路軸心４に向かって内側に傾斜している。また、上記弁箱シールリング３（すなわちシール片３ａ，３ｂ）の内周面１７は、開閉時、弁体７の周板部１０の外周縁が摺接する弁体摺接部分３５と、ディスクテール部１４，１５の外周面が摺接するテール摺接部分３６とを備えている。
【００３９】
図１５に示すように、上記テール摺接部分３６は、全閉位置Ｓよりも閉回転方向Ｄ（すなわち閉栓時の回転方向）の側（すなわち一方のシール片３ａにおいては下流側Ｂ、他方のシール片３ｂにおいては上流側Ａ）に位置している。また、上記弁体摺接部分３５は上記テール摺接部３６よりも開回転方向Ｃの側（すなわち一方のシール片３ａにおいては上流側Ａ、他方のシール片３ｂにおいては下流側Ｂ）に位置している。
【００４０】
尚、上記テール摺接部分３６の表面を薬品処理によって塩素化することにより、上記テール摺接部分３６の表面の摩擦係数を弁体摺接部分３５の表面の摩擦係数よりも小さくしている。尚、上記薬品処理として、容量比が［水１００，５．２５％の次亜塩素酸ナトリウム液３，３７％の塩酸０．５］の処理液を用い、この処理液から発生する塩素ガスで約３〜５時間表面を処理している。このような薬品処理をテール摺接部分３６に対して行うことにより、テール摺接部分３６の表面が硬化して摩擦係数が減少する。
【００４１】
以下、上記構成における作用を説明する。
図１５に示すように、弁体７を全閉位置Ｓにした場合、周板部１０の外周縁が弁箱シールリング３（すなわち、両シール片３ａ，３ｂ）の弁体摺接部分３５に摺接し、弁箱２内の流路２２が上記弁体７で全閉される。この際、弁体７の上流側Ａと下流側Ｂとは周板部１０の外周縁と弁箱シールリング３の弁体摺接部分３５とでシールされている。
【００４２】
また、図１６に示すように、弁体７を所定の小開度αにした場合、両ディスクテール部１４，１５の外周面が弁箱シールリング３のテール摺接部分３６に摺接し、通水孔１６が弁体７の上流側Ａと下流側Ｂとに連通する。これにより、弁箱２内の水（上水，工水，農水等）が弁体７の上流側Ａから通水孔１６を通って下流側Ｂへ流れ、小流量で下流側配管に充水される。
【００４３】
また、弁体７を開閉する際、全閉位置Ｓと所定の小開度αとの間の範囲においては、ディスクテール部１４，１５の外周面が上記テール摺接部分３６に対して摺動するが、テール摺接部分３６の表面の摩擦係数が薬品処理によって弁体摺接部分３５の表面の摩擦係数よりも減少しているため、ディスクテール部１４，１５の外周面と弁箱シールリング３のテール摺接部分３６との間の摩擦抵抗が減少し、弁体７の開閉時に要する操作力を軽減することができる。
【００４４】
上記各実施の形態では、図３に示すように、両ディスクテール部１４，１５にそれぞれ長円状の通水孔１６を１個ずつ形成しているが、両ディスクテール部１４，１５のいずれか片方のみに通水孔１６を形成してもよい。また、上記通水孔１６の形状は長円状に限定されるものではなく、円形や多角形等であってもよい。さらに、通水孔１６をディスクテール部１４，１５に複数個ずつ形成してもよい。
【００４５】
上記各実施の形態では、バタフライ弁１に対する使用流体として水（上水，工水，農水等）を挙げたが、水以外の液体又は気体であってもよい。
上記各実施の形態では、図７に示すように、弁体７を中空の本体部９とこの本体部９の外周に形成された板状の周板部１０とで構成しているが、このような形状に限定されるものではなく、例えば、第４の実施の形態として図１７に示すように、弁体７を、外周ほど次第に薄くなる円板状に形成し、中央にボス部１１を設けたものでもよい。
【００４６】
【発明の効果】
以上のように本第１発明では、弁体を開閉する際、全閉位置と所定の小開度との間の範囲においては、ディスクテール部の外周面が弁箱シールリングの凸部に対して摺動するため、この時のディスクテール部の外周面と弁箱シールリングとの接触面積が縮小される。これにより、摩擦抵抗が減少し、弁体開閉時に要する操作力を軽減することができる。
【００４７】
本第２発明では、弁体を開閉する際、全閉位置と所定の小開度との間の範囲においては、ディスクテール部の外周面がテール摺接部分に対して摺動するが、上記テール摺接部分の摩擦係数を薬品処理によって弁体摺接部分の摩擦係数よりも小さくしているため、ディスクテール部の外周面と弁箱シールリングのテール摺接部分との間の摩擦抵抗が減少し、弁体開閉時に要する操作力を軽減することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態におけるバタフライ弁の側面図である。
【図２】図１におけるＸ−Ｘ矢視図である。
【図３】同、バタフライ弁の弁体の斜視図である。
【図４】同、バタフライ弁の弁体を全閉位置にした際の横断面図である。
【図５】同、バタフライ弁の弁箱シールリングの断面図である。
【図６】同、バタフライ弁の弁体を全閉位置にした際の弁体と弁箱シールリングとの関係を示す拡大断面図である。
【図７】同、バタフライ弁の弁体を小開度だけ開いた際の横断面図である。
【図８】同、バタフライ弁の弁体を小開度の範囲内で開回転方向へ回転している際のディスクテール部と弁箱シールリングとの関係を示す拡大断面図である。
【図９】同、バタフライ弁の弁体を小開度の範囲内で閉回転方向へ回転している際のディスクテール部と弁箱シールリングとの関係を示す拡大断面図である。
【図１０】本発明の第２の実施の形態におけるバタフライ弁の弁箱シールリングの断面図である。
【図１１】同、バタフライ弁の弁体を全閉位置にした際の弁体と弁箱シールリングとの関係を示す拡大断面図である。
【図１２】同、バタフライ弁の弁体を小開度の範囲内で開回転方向へ回転している際のディスクテール部と弁箱シールリングとの関係を示す拡大断面図である。
【図１３】同、バタフライ弁の弁体を小開度の範囲内で閉回転方向へ回転している際のディスクテール部と弁箱シールリングとの関係を示す拡大断面図である。
【図１４】本発明の第３の実施の形態におけるバタフライ弁の弁箱シールリングの断面図である。
【図１５】同、バタフライ弁の弁体を全閉位置にした際の弁体と弁箱シールリングとの関係を示す拡大断面図である。
【図１６】同、バタフライ弁の弁体を小開度の範囲内で回転している際のディスクテール部と弁箱シールリングとの関係を示す拡大断面図である。
【図１７】本発明の第４の実施の形態におけるバタフライ弁の弁体を小開度だけ開いた際の横断面図である。
【図１８】従来のバタフライ弁の図であり、弁体を全閉位置にした状態を示す。
【図１９】同、バタフライ弁の図であり、弁体を小開度だけ開いた状態を示す。
【符号の説明】
１バタフライ弁
２弁箱
３弁箱シールリング
５弁棒
６軸心
７弁体
１４，１５ディスクテール部
１６通水孔
１７内周面
１９凸部
３０凸部
３５弁体摺接部分
３６テール摺接部分
Ｃ開回転方向
Ｄ閉回転方向
Ｓ全閉位置
α 小開度[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a butterfly valve having a water filling function, and relates to a technique of a valve for supplying a fluid at a constant flow rate when filling a pipe with water.
[0002]
[Prior art]
Conventionally, as a butterfly valve having a water filling function, for example, as shown in FIGS. 18 and 19, a rotary chamber orthogonal to a flow axis 53 is provided in a valve chamber 52 in which a flexible elastic sleeve 51 is mounted on the entire inner surface. In some cases, a rotatable valve body 55 is provided around an axis 54. The valve element 55 has a configuration in which a pair of valve pieces 55a and 55b each having a spherical outer peripheral surface are symmetrically arranged. At least one valve piece 55a is formed with a concave groove 56 for controlling the flow rate.
[0003]
According to this, as shown in FIG. 18, when the valve body 55 is at the fully closed position S, the outer peripheral surface of the valve body 55 is in sliding contact with the inner peripheral surface of the elastic sleeve 51, and the concave groove 56 is in the fully closed position S. Since it is located on the upstream side A, the flow path 57 in the valve chamber 52 is completely closed by the valve body 55.
[0004]
As shown in FIG. 19, when the valve body 55 is set to the predetermined small opening degree α, the outer peripheral surface of the valve body 55 comes into sliding contact with the inner peripheral surface of the elastic sleeve 51, and the concave groove 56 To communicate from the upstream side A to the downstream side B, the fluid in the valve chamber 52 flows from the upstream side A of the valve body 55 to the downstream side B through the concave groove 56. As a result, the downstream pipe is filled with water at a small flow rate (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-59-101054 [0006]
[Problems to be solved by the invention]
However, in the above-described conventional type, when the valve body 55 is opened and closed, the outer peripheral surface of the valve body 55 is in contact with the inner peripheral surface of the elastic sleeve 51 in a range between the fully closed position S and the predetermined small opening degree α. At this time, the contact area between the outer peripheral surface of the valve body 55 and the inner peripheral surface of the elastic sleeve 51 is increased, so that frictional resistance is increased and a large operating force is required when the valve body 55 is opened and closed. was there.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a butterfly valve having a water filling function capable of reducing an operation force required for opening and closing a valve body.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention provides a valve box seal ring made of an elastic body arranged in an annular shape along an inner peripheral surface in a valve box, and a valve ring rotating around an axis of a valve stem. A butterfly valve having a valve body slidingly contacting a valve box seal ring at a fully closed position, and a pair of disk tail portions attached to a back side of the valve body in the opening rotation direction, wherein the disk tail portion is a valve body. The valve body is formed in a fan shape in the rotation direction and provided on the peripheral edge of the valve body, and has a spherically curved outer peripheral surface, and at least one of the disk tail portions has one end opened to the outer peripheral surface and the other end A water passage hole is formed on the rear side of the valve body, and a convex portion that slides on the outer peripheral surface of the disk tail portion is formed on the inner peripheral surface of the valve box seal ring along the circumferential direction. Is located closer to the rotation direction than the fully closed position. When the valve body is at the fully closed position, the outer peripheral edge of the valve body slides against the inner peripheral surface of the valve box seal ring, and when the valve body is within a predetermined small opening degree, the outer periphery of the disc tail portion The surface is in sliding contact with the convex portion.
[0009]
According to this, when the valve body is in the fully closed position, the outer peripheral edge of the valve body is in sliding contact with the inner circumferential surface of the valve box seal ring, so that the flow path in the valve box is fully closed by the valve body. At this time, the upstream side and the downstream side of the valve body are sealed by the outer peripheral edge of the valve body and the inner peripheral surface of the valve box seal ring.
[0010]
When the valve body is set to a predetermined small opening degree, the outer peripheral surfaces of both disc tail portions are in sliding contact with the convex portions of the valve box seal ring, and the water holes communicate with the upstream side and the downstream side of the valve body. Accordingly, the fluid in the valve box flows from the upstream side of the valve body to the downstream side through the water hole, and is charged with a small flow rate to the downstream side pipe.
[0011]
Further, when the valve body is opened and closed, in the range between the fully closed position and the predetermined small opening, the outer peripheral surface of the disk tail slides with respect to the convex portion. The contact area between the outer peripheral surface of the valve body and the valve box seal ring is reduced. Thereby, the frictional resistance is reduced, and the operating force required for opening and closing the valve body can be reduced.
[0012]
Further, the second invention provides a valve box seal ring made of an elastic body which is annularly arranged along the inner peripheral surface in the valve box, A butterfly valve having a valve body that is in sliding contact with a seal ring and a pair of disk tail portions attached to the back side of the valve body in the opening rotation direction, wherein the disk tail portion is formed in a fan shape in the valve body rotation direction. It is provided on the peripheral edge of the valve body, and has a spherically curved outer peripheral surface that slides on the valve box seal ring when the valve body is at a small opening degree, and at least one of the disk tails has one end. A water passage hole is formed which opens to the outer peripheral surface and the other end opens to the back side of the valve body. The inner peripheral surface of the valve box seal ring slides on the outer peripheral edge of the valve body when the valve body opens and closes. Part and tail slide where the outer peripheral surface of the disk tail slides And a portion, in which is smaller than the friction coefficient of the valve body sliding portion by chemical treatment the coefficient of friction of the tail sliding contact area.
[0013]
According to this, when the valve body is in the fully closed position, the outer peripheral edge of the valve body slides on the valve body sliding contact portion of the valve box seal ring, and the flow path in the valve box is fully closed by the valve body. At this time, the upstream side and the downstream side of the valve element are sealed by the outer peripheral edge of the valve element and the valve element sliding contact portion of the valve box seal ring.
[0014]
Also, when the valve body is set to a predetermined small opening degree, the outer peripheral surfaces of both disc tail portions slide in contact with the tail sliding portion of the valve box seal ring, and the water holes communicate with the upstream side and the downstream side of the valve body. I do. Accordingly, the fluid in the valve box flows from the upstream side of the valve body to the downstream side through the water hole, and is charged with a small flow rate to the downstream side pipe.
[0015]
Further, when the valve body is opened and closed, in the range between the fully closed position and the predetermined small opening degree, the outer peripheral surface of the disk tail portion slides on the tail sliding contact portion. Because the friction coefficient of the part is made smaller than the friction coefficient of the valve body sliding contact part by chemical treatment, the frictional resistance between the outer peripheral surface of the disk tail part and the tail sliding contact part of the valve box seal ring decreases, The operating force required for opening and closing the valve body can be reduced.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 4, reference numeral 1 denotes a butterfly valve, and a valve box 2 has an upstream pipe (not shown) and a downstream pipe (not shown) connected to ports P1 and P2 on both sides. .
[0017]
In the valve box 2, a ring seal ring 3 made of an annular rubber (an example of an elastic body) is arranged along an inner peripheral surface. In the valve box 2, there is provided a freely openable and closable valve element 7 which rotates around an axis 6 of a valve rod 5 orthogonal to the flow path axis 4. The valve body 7 includes a disk-shaped main body 9 having a hollow inside, and a plate-shaped peripheral plate 10 formed on the outer periphery of the main body 9 and thinner than the main body 9.
[0018]
The valve stem 5 is inserted through a pair of cylindrical bosses 11 provided on the valve body 7 and integrally connected to each other, and is rotatably held by the valve box 2. The end of the valve stem 5 is operatively connected to a drive device (not shown) such as a manual handle for rotating the valve stem 5 to open and close the valve element 7 and a motor with a speed reducer.
[0019]
Further, a pair of disk tail portions 14 and 15 are provided on the back side of the valve body 7 in the opening rotation direction C (that is, the rotation direction at the time of opening). Each of the disk tail portions 14 and 15 is formed in a fan shape in the rotation direction of the valve body 7, is attached to the outer peripheral edge of the peripheral plate portion 10, and rises from the peripheral plate portion 10. The outer peripheral surfaces of the two disk tail portions 14 and 15 are each spherically curved. When the valve element 7 is rotated in the opening rotation direction C, one of the disk tails 14 is displaced toward the upstream side A, and the other disk tail 15 is displaced toward the downstream side B.
[0020]
Each of the disk tail portions 14 and 15 has a water passage hole 16 having one end opened to the outer peripheral surface and the other end opened to the back side of the valve element 7. The water passage hole 16 has an elongated oval shape along the circumferential direction of the valve body 7 and is formed at one location adjacent to the peripheral plate portion 10.
[0021]
The valve case seal ring 3 is constituted by a pair of semicircular seal pieces 3 a and 3 b divided into two parts at the position of the valve rod 5, and is fitted into a mounting groove 18 formed on the inner peripheral surface of the valve case 2. It is installed.
[0022]
The inner peripheral surface 17 of the one seal piece 3a is inclined more inward toward the flow axis 4 toward the downstream side B, and the inner peripheral face 17 of the other seal piece 3b is closer to the flow axis A toward the upstream side A. It is inclined inward toward 4. As shown in FIGS. 4 and 5, on the inner peripheral surface 17 of the valve box seal ring 3, a plurality of mountain-shaped convex portions 19 and valley-shaped concave portions 20 made of rubber (an example of an elastic body) are alternately formed. It is formed over the entire circumference. The convex portion 19 and the concave portion 20 are obtained by forming a plurality of grooves in parallel on the inner peripheral surface 17 of both seal pieces 3a and 3b, and the top of each convex portion 19 is formed by the two seal pieces 3a and 3b. The inner peripheral surface 17 is substantially flush with the inner peripheral surface 17 and is in sliding contact with the outer peripheral surfaces of the disk tail portions 14 and 15.
[0023]
As shown in FIG. 4, the convex portion 19 and the concave portion 20 are closer to the closing rotation direction D (that is, the rotation direction at the time of plugging) than the fully closed position S (that is, the downstream side B in one seal piece 3a, and the other side). Is located on the upstream side A). As shown in FIGS. 4 and 6, when the valve element 7 is at the fully closed position S, the outer peripheral edge of the peripheral plate portion 10 is formed on the inner peripheral surface of the valve box seal ring 3 (that is, both seal pieces 3a and 3b). 17 is in sliding contact. Also, as shown in FIGS. 7 to 9, when the valve element 7 is within the range of the predetermined small opening degree α, the outer peripheral surfaces of both the disc tail portions 14 and 15 are in sliding contact with the convex portion 19.
[0024]
Hereinafter, the operation of the above configuration will be described.
As shown by the solid line in FIG. 4, when the valve element 7 is in the fully closed position S, as shown in FIG. 6, the outer peripheral edge of the peripheral plate portion 10 is formed by the valve box seal ring 3 (that is, both seal pieces 3a and 3b). 2), the flow path 22 in the valve box 2 is fully closed by the valve element 7. At this time, the upstream side A and the downstream side B of the valve element 7 are sealed by the outer peripheral edge of the peripheral plate portion 10 and the inner peripheral surface 17 of the valve box seal ring 3.
[0025]
When the valve body 7 is set to a predetermined small opening degree α as shown in FIG. 7, the outer peripheral surfaces of the two disk tail portions 14 and 15 have convex portions of the valve box seal ring 3 as shown in FIGS. The water flow hole 16 is in sliding contact with the portion 19 and communicates with the upstream side A and the downstream side B of the valve element 7. As a result, water (water, industrial water, agricultural water, etc.) in the valve box 2 flows from the upstream side A of the valve body 7 to the downstream side B through the water passage hole 16 and fills the downstream side pipe with a small flow rate. Is done.
[0026]
When the valve element 7 is opened and closed, in the range between the fully closed position S and the predetermined small opening degree α, the outer peripheral surfaces of the two disk tail portions 14 and 15 do not slide on the concave portions 20. Since only the protrusions 19 are slid, the contact area between the outer peripheral surfaces of the disk tail portions 14 and 15 and the valve box seal ring 3 at this time is reduced. Thereby, frictional resistance is reduced, and the operating force required when opening and closing the valve body 7 can be reduced. Also, at this time, if the valve element 7 is rotating in the opening rotation direction C as shown in FIG. 8, each projection 19 falls down into each recess 20 on the opening rotation direction C side and escapes, as shown in FIG. If the valve element 7 is rotating in the closing rotation direction D, each of the protrusions 19 falls into each of the recesses 20 on the closing rotation direction D side and escapes. The operation of opening and closing the valve body 7 can be performed more smoothly without being pressed against the outer peripheral surface.
[0027]
As shown by the phantom line in FIG. 4, when the valve element 7 is fully opened by rotating about 90 ° in the opening rotation direction C from the fully closed position S, the valve element 7 is located on the flow axis 4. , The valve body 7 and the two disk tail portions 14 and 15 are separated from the valve box seal ring 3.
[0028]
In the first embodiment, the convex portion 19 and the concave portion 20 are formed on the inner peripheral surface 17 of the valve box seal ring 3 over the entire circumference. May be. Further, although the valve box seal ring 3, the convex portion 19 and the concave portion 20 are formed by rubber which is an example of an elastic body, a flexible material having elasticity other than rubber may be used.
[0029]
In the first embodiment, as shown in FIG. 5, a plurality of projections 19 and a plurality of depressions 20 are formed, but a single projection may be formed.
Next, a second embodiment of the present invention will be described with reference to FIGS.
[0030]
On the inner peripheral surface 17 of the valve box seal ring 3, a mountain-shaped convex portion 30 made of rubber (an example of an elastic body) is formed over the entire circumference. The convex portion 30 protrudes inward from the inner peripheral surface 17 of both seal pieces 3a, 3b toward the flow axis 4, and comes into sliding contact with the outer peripheral surfaces of both disk tail portions 14, 15.
[0031]
The convex portion 30 is singularly formed on each of the seal pieces 3a and 3b, and is located downstream of the fully closed position S in the closing rotation direction D (that is, the rotation direction at the time of plugging) (that is, downstream of the one seal piece 3a). Side B and the upstream side A) in the other seal piece 3b. As shown in FIG. 11, when the valve body 7 is at the fully closed position S, the outer peripheral edge of the peripheral plate portion 10 slides on the inner peripheral surface 17 of the valve box seal ring 3 (that is, both seal pieces 3a and 3b). Touch In addition, as shown in FIGS. 12 and 13, when the valve element 7 is within the range of the predetermined small opening degree α, the outer peripheral surfaces of both the disk tail portions 14 and 15 are in sliding contact with the convex portion 30.
[0032]
Hereinafter, the operation of the above configuration will be described.
As shown in FIG. 11, when the valve element 7 is in the fully closed position S, the outer peripheral edge of the peripheral plate portion 10 is in sliding contact with the inner peripheral surface 17 of the valve box seal ring 3 (that is, both the seal pieces 3a and 3b). Therefore, the flow path 22 in the valve box 2 is completely closed by the valve element 7. At this time, the upstream side A and the downstream side B of the valve element 7 are sealed by the outer peripheral edge of the peripheral plate portion 10 and the inner peripheral surface 17 of the valve box seal ring 3.
[0033]
In addition, as shown in FIGS. 12 and 13, when the valve body 7 is set to a predetermined small opening degree α, the outer peripheral surfaces of both disk tail portions 14 and 15 are in sliding contact with the convex portion 30 of the valve box seal ring 3, The water hole 16 communicates with the upstream side A and the downstream side B of the valve element 7. As a result, water (water, industrial water, agricultural water, etc.) in the valve box 2 flows from the upstream side A of the valve body 7 to the downstream side B through the water passage hole 16 and fills the downstream side pipe with a small flow rate. Is done.
[0034]
When the valve body 7 is opened and closed, as shown in FIGS. 12 and 13, in the range between the fully closed position S and a predetermined small opening degree α, the outer peripheral surfaces of both disc tail portions 14 and 15 Since the inner peripheral surface 17 of the valve box seal ring 3 does not slide and slides only on the convex portion 30, the outer peripheral surfaces of the disk tail portions 14, 15 and the valve box seal ring 3 at this time are not in contact with each other. Is reduced. Thereby, frictional resistance is reduced, and the operating force required when opening and closing the valve body 7 can be reduced. Also, at this time, if the valve element 7 is rotating in the opening rotation direction C as shown in FIG. 12, the convex portion 30 falls down to the upstream side A and escapes, and the valve element 7 closes and rotates as shown in FIG. If it rotates in the direction D, the convex portion 30 falls down to the downstream side B and escapes, so that the convex portion 30 is not excessively pressed against the outer peripheral surfaces of the disk tail portions 14 and 15, and Opening and closing operations can be performed more smoothly.
[0035]
In the second embodiment, the projection 30 is formed on the entire inner peripheral surface 17 of the valve box seal ring 3, but may be partially formed in the circumferential direction instead of the entire circumference. . In addition, although the valve box seal ring 3 and the protrusion 30 are formed of rubber, which is an example of an elastic body, a flexible material having elasticity other than rubber may be used.
[0036]
Next, a third embodiment of the present invention will be described with reference to FIGS.
The outer peripheral surfaces of the two disk tail portions 14 and 15 are each spherically curved, and as shown in FIG. 16, when the valve element 7 is within a predetermined small opening α, the valve box seal ring 3 In sliding contact with
[0037]
The valve case seal ring 3 is constituted by a pair of semicircular seal pieces 3 a and 3 b divided into two parts at the position of the valve rod 5, and is fitted into a mounting groove 18 formed on the inner peripheral surface of the valve case 2. It is installed.
[0038]
The inner peripheral surface 17 of the one seal piece 3a is inclined more inward toward the flow axis 4 toward the downstream side B, and the inner peripheral face 17 of the other seal piece 3b is closer to the flow axis A toward the upstream side A. It is inclined inward toward 4. The inner peripheral surface 17 of the valve box seal ring 3 (that is, the seal pieces 3a and 3b) has a valve body sliding contact portion 35 with which the outer peripheral edge of the peripheral plate portion 10 of the valve body 7 slides when opened and closed, and a disk tail. And a tail sliding contact portion 36 with which the outer peripheral surfaces of the portions 14 and 15 slide.
[0039]
As shown in FIG. 15, the tail sliding contact portion 36 is closer to the closing rotation direction D (that is, the rotation direction at the time of closing) than the fully closed position S (that is, the downstream side B in one seal piece 3a, and the other side). In the seal piece 3b, it is located on the upstream side A). Further, the valve body sliding contact portion 35 is located closer to the opening rotation direction C than the tail sliding contact portion 36 (that is, the upstream side A in one seal piece 3a and the downstream side B in the other seal piece 3b). are doing.
[0040]
By chlorinating the surface of the tail sliding contact portion 36 by chemical treatment, the friction coefficient of the surface of the tail sliding contact portion 36 is made smaller than the friction coefficient of the surface of the valve body sliding contact portion 35. In the above chemical treatment, a treatment solution having a volume ratio of [water 100, 5.25% sodium hypochlorite solution 3, 37% hydrochloric acid 0.5] was used, and chlorine gas generated from this treatment solution was used. The surface has been treated for about 3-5 hours. By performing such a chemical treatment on the tail sliding contact portion 36, the surface of the tail sliding contact portion 36 is hardened and the friction coefficient is reduced.
[0041]
Hereinafter, the operation of the above configuration will be described.
As shown in FIG. 15, when the valve element 7 is in the fully closed position S, the outer peripheral edge of the peripheral plate portion 10 is in contact with the valve element sliding contact portion 35 of the valve box seal ring 3 (that is, both seal pieces 3a and 3b). Sliding contact is made, and the flow path 22 in the valve box 2 is completely closed by the valve body 7. At this time, the upstream side A and the downstream side B of the valve body 7 are sealed by the outer peripheral edge of the peripheral plate portion 10 and the valve body sliding contact portion 35 of the valve box seal ring 3.
[0042]
As shown in FIG. 16, when the valve body 7 is set to a predetermined small opening degree α, the outer peripheral surfaces of the two disk tail portions 14 and 15 slidably contact the tail sliding contact portion 36 of the valve box seal ring 3 and The water hole 16 communicates with the upstream side A and the downstream side B of the valve body 7. As a result, water (water, industrial water, agricultural water, etc.) in the valve box 2 flows from the upstream side A of the valve body 7 to the downstream side B through the water passage hole 16 and fills the downstream side pipe with a small flow rate. Is done.
[0043]
When the valve 7 is opened and closed, the outer peripheral surfaces of the disk tail portions 14 and 15 slide with respect to the tail sliding contact portion 36 in a range between the fully closed position S and the predetermined small opening degree α. However, since the friction coefficient of the surface of the tail sliding portion 36 is smaller than the friction coefficient of the surface of the valve sliding portion 35 by the chemical treatment, the outer peripheral surfaces of the disk tail portions 14 and 15 and the valve box seal ring The frictional resistance between the third sliding contact portion 36 and the third sliding portion 36 is reduced, and the operating force required for opening and closing the valve body 7 can be reduced.
[0044]
In each of the above embodiments, as shown in FIG. 3, each of the disk tail portions 14, 15 is formed with one elliptical water passage hole 16, respectively. Alternatively, the water passage hole 16 may be formed only on one side. Further, the shape of the water passage hole 16 is not limited to an elliptical shape, and may be a circular shape or a polygonal shape. Further, a plurality of water passage holes 16 may be formed in each of the disk tail portions 14 and 15.
[0045]
In each of the above embodiments, water (tap water, industrial water, agricultural water, etc.) is used as the fluid used for the butterfly valve 1, but a liquid or gas other than water may be used.
In each of the above embodiments, as shown in FIG. 7, the valve body 7 is constituted by the hollow main body 9 and the plate-shaped peripheral plate 10 formed on the outer periphery of the main body 9. It is not limited to such a shape. For example, as shown in FIG. 17 as a fourth embodiment, the valve body 7 is formed in a disk shape that becomes gradually thinner toward the outer periphery, and the boss 11 is formed in the center. It may be provided.
[0046]
【The invention's effect】
As described above, in the first aspect of the present invention, when the valve body is opened and closed, in the range between the fully closed position and the predetermined small opening degree, the outer peripheral surface of the disk tail portion is in contact with the convex portion of the valve box seal ring. In this case, the contact area between the outer peripheral surface of the disk tail portion and the valve box seal ring is reduced. Thereby, the frictional resistance is reduced, and the operating force required for opening and closing the valve body can be reduced.
[0047]
According to the second aspect of the present invention, when the valve body is opened and closed, the outer peripheral surface of the disk tail portion slides with respect to the tail sliding contact portion in a range between the fully closed position and the predetermined small opening degree. Since the friction coefficient of the tail sliding part is made smaller than the friction coefficient of the valve sliding part by chemical treatment, the frictional resistance between the outer peripheral surface of the disk tail part and the tail sliding part of the valve box seal ring is reduced. The operation force required for opening and closing the valve body can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of a butterfly valve according to a first embodiment of the present invention.
FIG. 2 is a view taken along the line XX in FIG.
FIG. 3 is a perspective view of a valve body of the butterfly valve.
FIG. 4 is a transverse sectional view when the valve body of the butterfly valve is in a fully closed position.
FIG. 5 is a sectional view of a valve box seal ring of the butterfly valve.
FIG. 6 is an enlarged cross-sectional view showing the relationship between the valve body and the valve box seal ring when the valve body of the butterfly valve is at the fully closed position.
FIG. 7 is a transverse sectional view when the valve body of the butterfly valve is opened by a small opening.
FIG. 8 is an enlarged cross-sectional view showing the relationship between the disc tail portion and the valve box seal ring when the valve body of the butterfly valve is rotating in the opening rotation direction within a small opening range.
FIG. 9 is an enlarged cross-sectional view showing the relationship between the disc tail and the valve box seal ring when the valve body of the butterfly valve is rotating in the closing rotation direction within a small opening range.
FIG. 10 is a sectional view of a valve box seal ring of a butterfly valve according to a second embodiment of the present invention.
FIG. 11 is an enlarged sectional view showing the relationship between the valve body and the valve box seal ring when the valve body of the butterfly valve is at the fully closed position.
FIG. 12 is an enlarged cross-sectional view showing a relationship between a disc tail portion and a valve box seal ring when the valve body of the butterfly valve is rotating in an opening rotation direction within a small opening range.
FIG. 13 is an enlarged cross-sectional view showing the relationship between the disc tail and the valve box seal ring when the valve body of the butterfly valve is rotating in the closing direction within a small opening range.
FIG. 14 is a sectional view of a valve box seal ring of a butterfly valve according to a third embodiment of the present invention.
FIG. 15 is an enlarged sectional view showing the relationship between the valve body and the valve box seal ring when the valve body of the butterfly valve is at the fully closed position.
FIG. 16 is an enlarged sectional view showing the relationship between the disc tail and the valve box seal ring when the valve body of the butterfly valve is rotating within a small opening range.
FIG. 17 is a cross-sectional view of a butterfly valve according to a fourth embodiment of the present invention when the valve body is opened by a small opening.
FIG. 18 is a view of a conventional butterfly valve, showing a state where a valve body is in a fully closed position.
FIG. 19 is a view of the butterfly valve, showing a state where the valve body is opened by a small opening degree.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Butterfly valve 2 Valve case 3 Valve case seal ring 5 Valve rod 6 Shaft 7 Valve element 14, 15 Disc tail part 16 Water hole 17 Inner peripheral surface 19 Convex part 30 Convex part 35 Valve body sliding contact part 36 Tail sliding contact Part C Open rotation direction D Close rotation direction S Fully closed position α Small opening

Claims

A valve box seal ring made of an elastic body arranged in an annular shape along the inner peripheral surface in the valve box; and a valve body that rotates around the axis of the valve rod and slides on the valve box seal ring at the fully closed position. A butterfly valve having a pair of disk tails attached to the back side of the valve element in the opening rotation direction, wherein the disk tail part is formed in a fan shape in the valve element rotation direction and is provided at a peripheral edge of the valve element. Provided, and has an outer peripheral surface curved in a spherical shape, at least one of the disk tail portion, there is a water hole having one end opened to the outer peripheral surface and the other end opened to the back side of the valve body. A convex portion is formed along the circumferential direction on the inner peripheral surface of the valve box seal ring, the convex portion slidingly contacting the outer peripheral surface of the disk tail portion, and the convex portion is located closer to the rotation direction than the fully closed position. When the valve is in the fully closed position, The water filling function, wherein the rim slides on the inner peripheral surface of the valve box seal ring, and when the valve element is within a predetermined small opening range, the outer peripheral surface of the disk tail portion slides on the convex portion. With butterfly valve.

A valve box seal ring made of an elastic body arranged in an annular shape along the inner peripheral surface in the valve box; and a valve body that rotates around the axis of the valve rod and slides on the valve box seal ring at the fully closed position. A butterfly valve having a pair of disk tails attached to the back side of the valve element in the opening rotation direction, wherein the disk tail part is formed in a fan shape in the valve element rotation direction and is provided at a peripheral edge of the valve element. A valve body having a spherically curved outer peripheral surface which is in sliding contact with the valve box seal ring when the valve body is at a small opening degree, and at least one of the disk tail portions has one end opened to the outer peripheral surface and the other end A water passage hole is formed on the back side of the valve body, and an inner peripheral surface of the valve box seal ring has a valve body sliding contact portion where an outer peripheral edge of the valve body slides when opening and closing, and an outer periphery of a disk tail portion. A tail sliding contact portion with which the surface slides, Butterfly valve provided with a filling of water functions, characterized in that is smaller than the friction coefficient of the valve body sliding portion by the friction coefficient chemical treatment of Lumpur sliding contact area.