JP3725501B2

JP3725501B2 - Constant pressure reducing valve for water supply

Info

Publication number: JP3725501B2
Application number: JP2002225587A
Authority: JP
Inventors: 伸幸松浦; 寿之山口
Original assignee: 兼工業株式会社
Priority date: 2002-08-02
Filing date: 2002-08-02
Publication date: 2005-12-14
Anticipated expiration: 2022-08-02
Also published as: JP2004070465A; SG102065A1; HK1062843A1; CN1472460A; CN100334378C

Description

【０００１】
【発明の属する技術分野】
本発明は、一次側圧力に対し二次側圧力を所定の比率に保持する水道用の定比減圧弁に関する。
【０００２】
【従来の技術】
高層建築物等において、各階層の水道水の圧力差を無くし、各戸へ水道水を均等に供給するためには、水道本管から各戸へ供給される支管に一次側圧力に対する二次側圧力の比率を各階層毎に設定した減圧弁を配管する必要があった。
しかしながら、既設の配管にダイアフラム式等の大型の減圧弁を取り付けることは、非常に困難であった。
そのため、大型の減圧弁に比し、小型で取付けが比較的容易なインライン式の定比減圧弁を水道メータの二次側（出口）と下流側配水管との間に介装連結して各階層の水道水の圧力差を無くす様にしているが、配管の長さを調節してもなお配管中に設定できる定比減圧弁の介装間隔は極めて短いため、ユニオンナットを利用して定比減圧弁を配管している。
上記定比減圧弁の具体的な構造の一例を図６〜８に示し説明する。
この減圧弁ａは、流入口ｂと、該流入口ｂより大径な流出口ｃとを各端部に設けた円筒状の弁箱ｄに、流入口ｂを開閉する弁部ｅを一端に設けると共に、他端が流出口ｃに開口した中空部ｆを設けたピストンｇを摺動自在に挿嵌し、該ピストンｇの一端側周囲には断面積が流入口ｂの面積より大きく設定された弁箱ｄ内壁との間隙ｈを設け、該間隙ｈを介して弁箱ｄ内壁に面するピストンｇ周壁の十字方向には前記中空部ｆに連通する通水口ｉを開設しており、弁箱ｄの流入口側端部には、ユニオンナットｊを摺動自在に装着し、弁箱ｄの流出口側端部の外周には、下流配管の端部に螺入するテーパーネジｋを螺刻している。
尚、一次側圧力に対する二次側圧力の比率は、一次側圧力を受圧する弁部ｅの面積、即ち、流入口ｂの口径を設定することにより変更している。
【０００３】
【発明が解決しようとする課題】
そして、この減圧弁ａを水道メータと下流側配水管との間に介装するには、その間隔が極めて短く、弁箱ｄ全長より若干長い程度のため、ユニオンナットｊを流出口ｃ側へ一旦スライドした状態で、弁箱ｄの流出口側端部を下流側配水管に螺入し、その後ユニオンナットｊを流入口ｂ側へスライドして水道メータにユニオンナットｊを螺着せねば、減圧弁ａを比較的容易に配管できなかった。
しかも、上記構成の定比減圧弁ａでは、ユニオンナットｊを弁箱ｄの長さ方向へスライドする様に成しているため、弁箱ｄは、ユニオンナットｊの挿通穴ｍに対応した外径でなければならないが、この様に、弁箱ｄの外径、全長に制約があるため、流入口ｂの口径も必然的に小径に成らざるを得ず、よって圧力損失が大きくなり、安定した流量の確保が困難であった。
【０００４】
【課題を解決するための手段】
本発明は、上記課題に鑑み、流入口と、該流入口より大径に設定した流出口とを端部の夫々に設けた円筒状の弁箱に、流入口を開閉する弁部を一端に設けると共に、他端側が流出口に開口した中空部を設けたピストンを摺動自在に挿嵌し、該ピストンの一端側周囲には断面積が流入口の面積より大きく設定された弁箱内壁との間隙を設け、該間隙を介して弁箱内壁に面するピストン周壁に環状の陥没面を凹設し、該陥没面には、前記中空部に連通すると共に、陥没面の幅と同径の通水口を軸線に対し鋭角を以て流出口向きの斜めにして、且つ、狭小間隔を置いて複数開設し、通水口の総面積は、流入口の面積及び通水口の総面積を除いた陥没面の面積のいずれよりも大きく設定することにより、圧力損失を小さくした流路形状を構成した定比減圧弁を提供し、更にかかる定比減圧弁を水道メータの出口内部や、水道メータの二次側に配管される水道器具内部に収容する様にして、定比減圧弁の配管作業をも省ける様にして、上記課題を解決する。
【０００５】
【発明の実施の形態】
以下本発明の一実施例を図面に基づいて説明する。
１は高層マンション等の各戸に装備される水道メータ（図示せず）の二次側（出口）と下流側配水管（図示せず）との間に介装されるインライン形の水道用定比減圧弁であり、該定比減圧弁１は、その弁箱２と、該弁箱２に内装したピストン３とから主に構成されている。
弁箱２は、円筒状に形成され、その各端部の夫々に流入口４と、該流入口４より大径に設定した流出口５とを設け、流入口４の二次側開口部周縁には弁座６を突設している。
又、弁箱２は、流入口４を水道メータの出口外周に設けたユニオンネジに螺着するユニオンナット７の挿通穴7aに摺動自在な外径を有し、弁箱２の流入口端部4aの外周にはユニオンナット７を抜止め掛止するユニオン鍔８を突設し、流出口端部5aの外周には、下流管に螺入されるテーパーネジ９を螺刻している。
尚、ユニオン鍔８の端面には、水道メータの出口端面に密着する様に成した円環状のパッキン10を接着している。
【０００６】
ピストン３は、弁座６に着離することにより流入口４を開閉する弁部11を一端に設けると共に、他端側が流出口５に開口した中空部12を設けた円筒状に形成され、弁箱２内の略中間部位に設けた縮径部13に、Ｕパッキン14で以て気密状にして、且つ、摺動自在に挿嵌している。
そして、ピストン３の一端（弁部11の形成端部）側周囲には、開弁時に流入口４と連通して圧力流体の流路の一部と成る弁箱２内壁との間隙15が設けられ、該間隙15の断面積（弁箱２とピストン３との間のリング状の面積に相当）は流入口４の面積S₁よりも大きく設定して成り、又ピストン３の他端（開口端）の周縁には、Ｕパッキン16を周設したフランジ17を突設し、該フランジ17を弁箱２内壁に摺動自在に内接している。
間隙15を介して弁箱２内壁に常に面するピストン３周壁には、環状の陥没面18を凹設し、該陥没面18には、ピストン３の中空部12に連通すると共に、陥没面18の幅と同径の通水口19を弁箱２の軸線に対し鋭角（図示例では約６０度）を以て流出口５向きの斜めにして、且つ、狭小間隔Ｌを置いて複数（図示例では６個）開設し、通水口19の総面積Saは、流入口４の面積S₁よりも大きく（Sa＞S₁）設定すると共に、陥没面18の全面積Sb（通水口19の総面積Saを含む）から通水口19の総面積Saを除いた陥没面18の面積（Sb−Sa）よりも大きく（Sa＞Sb−Sa）設定している（図１、３参照）。
【０００７】
又、ピストン３において、弁部11の背面には、通水口19の出口19ａに連続して、ピストン３の中心へ向かい傾斜した略漏斗状の凹面部20を凹設している。
弁箱２の流出口５内周には、ピストン３（フランジ17）を抜止めする止め輪21を突設しており、ピストン３のストロークは止め輪21にフランジ17が当接するまでの距離に相当し、かかる状態において縮径部13は通水口19を閉じない様に設定されている（図２参照）。
尚、弁箱２において、縮径部13とフランジ17との間の気密空間は、弁箱２に開設した通気口22にて外部と連通し、ピストン３が支障なく動作できる様に成している。
【０００８】
上記実施例では、水道メータの出口と下流側配水管との間に定比減圧弁１を介装するものを示したが、定比減圧弁１は、その弁箱２の流入口４及び流出口５を一次側及び二次側の夫々に対応させ、図４に示す様に、水道メータＭの出口Ｍ１内部、又は、図５に示す様に、水道メータの下流側に配管される水道器具Ｎの内部に収容しても良い。
この場合、弁箱２は、ユニオン鍔８とテーパーネジ９を廃し、流入口端部4a及び流出口端部5aの外径が同一な直円柱状に形成している。
定比減圧弁１を収容する水道メータＭの出口Ｍ１は、弁箱２の全長より若干長い直管状に形成され、出口Ｍ１の内部において、その奥方には、弁箱２の流入口端部4aより若干小径な環状段部Ｍ２を縮径形成し、該環状段部Ｍ２に弁箱２の流入口端部4aを当接し、流出口端部5aに対応した出口Ｍ１側端内周には、流出口端部5aに当接して弁箱２及びピストン３を抜止めする止め輪21を突設している。
そして、出口Ｍ１の側部には、通気口22と外部とを連通する通気路Ｍ３を設けると共に、出口Ｍ１の内部において、通気路口Ｍ４の前後には、通気路Ｍ３と通気口22との気密性を保持するシール部材（Ｏリング）Ｇを周設している。
水道メータの下流側に配管される水道器具Ｎは、配水管、止水栓等のバルブであって、定比減圧弁１は、直線状の配水管の出口又は入口内部、或いは、バルブに設けた直管状の入口内部に収容される。
配水管の出口内部に定比減圧弁１を収容する構成は、水道メータＭの出口Ｍ１に収容した構成と同一のため図示を省略し、配水管又はバルブの入口内部に定比減圧弁１を収容した構成を図５に示すが、その基本構成は、上記と同様である。
即ち、水道器具（配水管又はバルブ）Ｎの入口Ｎ１内部は、その奥方に弁箱２の流出口端部5aに当接すると共に、ピストン３のストローク端に設けた止め輪21に代替される環状段部Ｎ２を縮径形成し、流入口端部4aに対応した入口Ｎ１側端内周に、流入口端部4aに当接して弁箱２を抜止めする止め輪Ｒを突設し、上記と同様に、通気口22と外部とを連通する通気路Ｎ３を入口Ｎ１の側部に設け、該入口Ｎ１の内部における通気路口Ｎ４の前後にシール部材Ｇを周設している。
【０００９】
次に、本発明に係る定比減圧弁１の作用について説明する。
この定比減圧弁１において、ピストン３の形状は、流入口４と流出口５の口径差を利用してピストン３の弁部11に作用する一次側方向の作用力と、ピストン３の中空部12側に作用する二次側方向の流体作用力（中空部12側の二次側圧力の受圧面積（流出口５の面積S₂に相当）と二次側圧力P₂の積）が釣り合う様に構成されている。
一次側方向の作用力は、弁部11の一次側圧力の受圧面積（流入口４の面積S₁に相当）と一次側圧力P₁の積、弁部11の二次側圧力の受圧面積（弁部11の全面積S₃から一次側圧力の受圧面積S₁を除いた環状面の面積（S₃−S₁）に相当）と二次側圧力P₂の積、及びＵパッキン14、16等に基づくピストン３の摩擦抵抗力αの和である。
即ち、S₁P₁＋（S₃−S₁）P₂＋α＝S₂P₂であり、
P₂＝（S₁P₁＋α）／（S₂−(S₃ −S₁))を得る。
故に、二次側圧力P₂は、一次側圧力P₁を受圧面積（S₂−(S₃ −S₁))と、受圧面積S₁、及び摩擦抵抗αとで決まる値に減圧した圧力となる。
上述の通り、流入口４は流出口５より小径に設定しているため、流入口４の面積S₁は流出口５の面積S₂より小さく（S₁＜S₂）、又弁部11における環状面の面積（S₃−S₁）は流入口４の面積S₁により設定（尚、S₃≦S₂である。）されるから、二次側圧力は流入口４の面積S₁（口径）を変更することにより設定できる。
従って、定比減圧弁１は、二次側圧力が所定圧の時、弁部11が弁座６に着座して閉弁状態であり、給水栓を開いて水を使用することにより、二次側圧力が所定圧より降下すると、一次側圧力により弁部11が弁座６離間して開弁し、一次側流体は流入口４、間隙15、通水口19及び中空部12を経て二次側へ流入する。
【００１０】
上記開弁状態における圧力流体（水道水）の流れについて詳述すると、流入口４から間隙15に流入した圧力流体は、ピストン３の母線に沿った流れを生じ、通水口19がピストン３外周より落ち込んだ位置（陥没面18上）にあるので、ピストン３の母線に沿って流れる圧力流体は環状の窪みに沿って通水口19へ流れ込む。
そして、間隙15の断面積及び通水口19の総面積Saは、流入口４の面積S₁よりも大きいため、圧力流体の滞りのない通過面積を確保できると共に、通水口19の総面積Saは、その面積Saを除いた陥没面18の面積（Sb−Sa）よりも大きく、陥没面18に対する通水口19の開口度が大きく、しかも各通水口19は陥没面18の全周に渡って狭小なる間隔Ｌを置いて隣接しているため、間隔Ｌに阻まれる流れよりも通水口19へ流入する流れが多く、全体的に通水口19へ流入する圧力流体の流れの圧力損失が小さく、通水口19の通過流量が多く確保される。
尚、従来の定比減圧弁ａ（以下、従来品ａと称する。）では、通水口ｉの総面積Sxは、流入口４の面積Szよりも大きいが、通水口ｉの口径を幅としたピストン円周上の環状面（図６において陥没面18に対応した一点鎖線間の面）の面積Syから通水口ｉの総面積Sxを除いた面積（Sy−Sx）より通水口ｉの総面積Sxが小さく、本発明の定比減圧弁１に比し、隣接する通水口ｉの間隔L1が大きいので、通水口ｉへ流入する流体の流れよりも、通水口ｉの間隔L1に流れが阻まれる割合が高く、全体的に通水口ｉへ流入する圧力流体の流れの圧力損失が大きくなり、本発明の定比減圧弁１に比し、通水口ｉの通過流量が多く確保できない。
又、通水口19へ流入した圧力流体は、通水口 19 が、従来品ａの様に流れ方向（弁箱２の軸線方向に相当）に対し直角でなく、軸線に対し鋭角を以て中空部12へ連通しているため、従来品ａに比し圧力流体の流れの抵抗が小さくなる。
そして、各通水口19を通過し中空部12内に流入する圧力流体は、通水口19の出口より連続してピストン３の中心に向かって傾斜する斜面に沿って剥離することの無い流れ、あたかも翼の表面に沿ってよどみなく流れる流体と同様な流れを生じた後に合流するため、合流時に負圧を生じ難く安定した流れの圧力流体が下流側へ流動する。
これに対し、従来品ａでは、通水口ｉから中空部ｆへ流入する圧力流体は、弁部ｅの背面が通水口ｉに沿った平坦のため、中空部ｆ内で激しく衝突して合流することと成り、その合流時に弁部ｅの背面中央に負圧を生じて、圧力流体の流れの圧力損失が増大し、下流へ流動する。
この様に、本発明の定比減圧弁１は、従来品ａに比し、開弁時における圧力流体の圧力損失が全体的に小さく、安定した流量が確保される。
そして、水の使用後、給水栓を閉じると、二次側圧力が上昇するに伴ってピストン３は一次側へ押し戻され、二次側圧力が所定圧に達した時点で閉弁する。
【００１１】
【発明の効果】
要するに本発明は、流入口４と、該流入口４より大径に設定した流出口５とを端部の夫々に設けた円筒状の弁箱２に、流入口４を開閉する弁部11を一端に設けると共に、他端側が流出口５に開口した中空部12を設けたピストン３を摺動自在に挿嵌し、該ピストン３の一端側周囲には断面積が流入口４の面積S₁より大きく設定された弁箱２内壁との間隙15を設け、該間隙15を介して弁箱２内壁に常に面するピストン３周壁に、中空部12に連通する通水口19を複数開設したので、二次側圧力P₂は一次側圧力P₁に対し所定の比率に減圧できるため、弁箱２の口径を変更することなく、流入口４の面積S₁（口径）を変更することで、高層建築物の各階層における二次側圧力を同一に設定でき、水道配管と外径が略同一で軸線方向の長さの短い弁箱２を用いることができ、定比減圧弁１を取付けスペースの小さい箇所にも容易に設置できる。
又、各通水口19は、ピストン３周壁に凹設した通水口19と同径の幅を有する環状の陥没面18上に設けたので、開弁時において、流入口４から間隙15へ流入してピストン３の母線に沿う圧力流体の流れは、通水口19が形成された陥没面18へよどみなく導かれ、通水口19へ到達するまでの流体の圧力損失を軽減することができると共に、陥没面18に形成された通水口19は、従来の様に軸線に対し直角でなく、軸線に対し鋭角を以て流出口５向きの斜めに中空部12へ連通したので、一次側から二次側への流れの方向に、より即した流れを保持でき、通水口19から中空部12へ到達するまでの流体の圧力損失を軽減でき、全体的に圧力損失の小さい流れを保持できる。
更に、間隙15の断面積及び通水口19の総面積Saが流入口４の面積S₁より大きく設定されることで、圧力流体の滞りのない通過面積を確保できると共に、通水口19の総面積Saは、その面積Saを除いた陥没面18の面積（Sb−Sa）よりも大きくして、陥没面18に対する通水口19の開口度を大きくでき、しかも各通水口19は陥没面18の全周に渡って狭小なる間隔Ｌを置いて隣接しているので、間隔Ｌに阻まれる流れよりも通水口19へ流入する流れが多くでき、全体的に通水口19へ流入する圧力流体の流れの圧力損失が小さく、通水口19の通過流量を多く確保できる。
この様に、本発明によれば、全体的に圧力損失の小さい流路（流入口４、間隙15、通水口19、中空部12及び流出口５）を構成できるので、所望する流量を確保でき、単に流入口４の面積S₁を設定することにより、高層建築物の各階層の二次側圧力を同一に設定できると共に、安定した流量を供給できる。
従って、例え弁箱２が、ユニオンナット７の挿通穴7aに摺動自在な外径に形成され、且つ、水道メータと下流側配水管との間隔が短くても、ユニオンナット７を弁箱２上で前後に摺動させることで、従来品ａでは期待できなかった安定した流量の確保が可能な定比減圧弁１を容易に取付けできる。
【００１２】
ピストン３において、弁部11の背面には、通水口19の出口19ａに連続して、ピストン３の中心へ向かい傾斜した略漏斗状の凹面部20を凹設したので、通水口19から中空部12へ流入する圧力流体は、軸線に対し鋭角を以て流出口５に向かって傾斜した通水口19の出口19ａより連続してピストン３の中心に向かい傾斜する凹面部20の斜面に沿って剥離することのない流れを生じて合流し、下流側へ流動するため、従来品ａの様に負圧を生じ難く、圧力損失の小さい流れを生じさせられ、上記効果と相俟って全体的により圧力損失の小さい流れと成すことができ、より一層安定した流量を確保できる。
【００１３】
流入口４及び流出口５を一次側及び二次側の夫々に対応させた弁箱２を水道メータＭの出口Ｍ１内部に収容したり、又は、弁箱２を水道メータの二次側に配管される水道器具Ｎ内部に収容したので、水道メータＭ又は水道器具Ｎに上記性能を具有させられると共に、定比減圧弁１を水道メータと下流側配水管との介装連結する必要がないため、配管作業の手間を省いてその作業効率を向上させることができる等その実用的効果甚だ大である。
【図面の簡単な説明】
【図１】水道用定比減圧弁の閉弁状態を示す断面図である。
【図２】開弁状態を示す断面図である。
【図３】図１のＡーＡ断面図である。
【図４】水道メータの出口内部に水道用定比減圧弁を収容した状態を示す断面図である。
【図５】水道器具の入口内部に水道用定比減圧弁を収容した状態を示す断面図である。
【図６】従来の水道用定比減圧弁の閉弁状態を示す断面図である。
【図７】開弁状態を示す断面図である。
【図８】図６のＢーＢ断面図である。
【符号の説明】
２弁箱
３ピストン
４流入口
５流出口
７ユニオンナット
7a 挿通穴
11 弁部
12 中空部
15 間隙
18 陥没面
19 通水口
19ａ出口
20 凹面部
Ｌ狭小間隔
Ｍ水道メータ
Ｍ１出口
Ｎ水道器具
S₁ 流入口面積
Sa 通水口の総面積
Sb−Sa 通水口の総面積を除いた陥没面の面積[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a constant ratio pressure reducing valve for water supply that maintains a secondary pressure at a predetermined ratio with respect to a primary pressure.
[0002]
[Prior art]
In high-rise buildings, etc., in order to eliminate the difference in tap water pressure at each level and supply tap water evenly to each house, the secondary side pressure relative to the primary side pressure is supplied to the branch pipe supplied from the water main to each house. It was necessary to pipe a pressure reducing valve with the ratio set for each level.
However, it was very difficult to attach a large pressure reducing valve such as a diaphragm type to the existing piping.
For this reason, an in-line constant ratio pressure reducing valve that is small and relatively easy to install compared to a large pressure reducing valve is connected between the secondary side (outlet) of the water meter and the downstream water pipe. Although the pressure difference of tap water in the floor is eliminated, the interval between the constant pressure reducing valves that can be set in the pipe is very short even if the length of the pipe is adjusted. A specific pressure reducing valve is connected.
An example of a specific structure of the constant ratio pressure reducing valve will be described with reference to FIGS.
The pressure reducing valve a has a cylindrical valve box d provided with an inlet b and an outlet c larger in diameter than the inlet b at each end, and a valve portion e that opens and closes the inlet b at one end. In addition, a piston g provided with a hollow part f whose other end is open to the outlet c is slidably inserted, and a cross-sectional area is set larger than the area of the inlet b around the one end side of the piston g. A gap h with the inner wall of the valve box d is provided, and a water passage port i communicating with the hollow part f is opened in the cross direction of the piston g peripheral wall facing the inner wall of the valve box d through the gap h. A union nut j is slidably attached to the inlet side end of the box d, and a taper screw k screwed into the end of the downstream pipe is screwed to the outer periphery of the outlet side end of the valve box d. Engraved.
Note that the ratio of the secondary pressure to the primary pressure is changed by setting the area of the valve portion e that receives the primary pressure, that is, the diameter of the inlet b.
[0003]
[Problems to be solved by the invention]
In order to interpose this pressure reducing valve a between the water meter and the downstream water distribution pipe, the interval is extremely short and slightly longer than the total length of the valve box d, so that the union nut j is moved to the outlet c side. If the outlet side end of the valve box d is screwed into the downstream water pipe after sliding, then the union nut j is slid to the inlet b side and the union nut j is not screwed into the water meter. The valve a could not be piped relatively easily.
Moreover, in the constant ratio pressure reducing valve a configured as described above, since the union nut j is slid in the length direction of the valve box d, the valve box d is an outer part corresponding to the insertion hole m of the union nut j. However, since the outer diameter and overall length of the valve box d are limited in this way, the diameter of the inlet b must inevitably be reduced, and the pressure loss is increased and stable. It was difficult to secure the required flow rate.
[0004]
[Means for Solving the Problems]
In view of the above problems, the present invention provides a cylindrical valve box provided with an inlet and an outlet set to have a larger diameter than the inlet, and a valve portion for opening and closing the inlet at one end. And a valve box inner wall whose cross-sectional area is set larger than the area of the inflow port around the one end side of the piston. An annular recessed surface is recessed in the piston peripheral wall facing the inner wall of the valve box through the clearance, and the recessed surface communicates with the hollow portion and has the same diameter as the width of the recessed surface. A plurality of water inlets are inclined at an acute angle with respect to the axis toward the outlet, and at a small interval, and the total area of the inlet is the area of the recessed surface excluding the area of the inlet and the total area of the inlet. A constant ratio configured with a flow path shape that reduces pressure loss by setting it to be larger than any of the areas. A pressure valve is provided, and the constant ratio pressure reducing valve is housed inside the outlet of the water meter or in the water supply pipe that is piped on the secondary side of the water meter so that the piping work of the constant ratio pressure reducing valve can be omitted. Thus, the above problem is solved.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
1 is a constant ratio for in-line water supply that is interposed between a secondary side (exit) of a water meter (not shown) installed in each unit of a high-rise apartment or the like and a downstream water pipe (not shown). The constant ratio pressure reducing valve 1 is mainly composed of a valve box 2 and a piston 3 built in the valve box 2.
The valve box 2 is formed in a cylindrical shape, and is provided with an inflow port 4 and an outflow port 5 having a diameter larger than that of the inflow port 4 at each end thereof. Is provided with a valve seat 6.
The valve box 2 has a sliding outer diameter in an insertion hole 7a of a union nut 7 that is screwed into a union screw provided on the outer periphery of the outlet of the water meter. A union bar 8 for retaining and latching the union nut 7 is projected on the outer periphery of the portion 4a, and a taper screw 9 screwed into the downstream pipe is threaded on the outer periphery of the outlet end portion 5a.
An annular packing 10 formed so as to be in close contact with the outlet end surface of the water meter is bonded to the end surface of the union rod 8.
[0006]
The piston 3 is formed in a cylindrical shape in which a valve portion 11 that opens and closes the inlet 4 by being attached to and detached from the valve seat 6 is provided at one end, and a hollow portion 12 that is open to the outlet 5 is provided on the other end side. A U-packing 14 is used to slidably fit the reduced diameter portion 13 provided at a substantially intermediate portion in the box 2 with a U packing 14.
A clearance 15 between the piston 3 and the inner wall of the valve box 2 that forms a part of the flow path of the pressure fluid is provided around one end (formation end portion of the valve portion 11) side of the piston 3 when the piston 3 is opened. is made set to be larger than (ring-shaped corresponding to the area between the valve casing 2 and the piston 3) the area S ₁ of the inlet 4 the cross-sectional area of the gap 15, the other end of the piston 3 (opening A flange 17 having a U-packing 16 is provided on the peripheral edge of the end, and the flange 17 is slidably inscribed on the inner wall of the valve box 2.
An annular recessed surface 18 is recessed in the peripheral wall of the piston 3 that always faces the inner wall of the valve box 2 through the gap 15, and the recessed surface 18 communicates with the hollow portion 12 of the piston 3. A plurality of water inlets 19 having the same diameter as the width of the valve box 2 are slanted toward the outlet 5 with an acute angle (about 60 degrees in the illustrated example) with respect to the axis of the valve box 2 and at a narrow interval L (in the illustrated example, 6 The total area Sa of the water inlet 19 is set larger than the area S _{1 of the} inlet 4 (Sa> S ₁ ), and the total area Sb of the depressed surface 18 (the total area Sa of the water inlet 19 is It is set to be larger (Sa> Sb−Sa) than the area (Sb−Sa) of the depressed surface 18 excluding the total area Sa of the water inlet 19 (see FIG. 1 and FIG. 3).
[0007]
Further, in the piston 3, a substantially funnel-shaped concave surface portion 20 that is inclined toward the center of the piston 3 is provided on the back surface of the valve portion 11 continuously to the outlet 19 a of the water flow port 19.
A retaining ring 21 is provided on the inner periphery of the outlet 5 of the valve box 2 to prevent the piston 3 (flange 17) from being pulled out. The stroke of the piston 3 is the distance until the flange 17 contacts the retaining ring 21. Correspondingly, in such a state, the reduced diameter portion 13 is set so as not to close the water inlet 19 (see FIG. 2).
In the valve box 2, an airtight space between the reduced diameter portion 13 and the flange 17 communicates with the outside through a vent 22 formed in the valve box 2 so that the piston 3 can operate without any trouble. Yes.
[0008]
In the above-described embodiment, the constant ratio pressure reducing valve 1 is interposed between the outlet of the water meter and the downstream side distribution pipe, but the constant ratio pressure reducing valve 1 is connected to the inlet 4 and the flow of the valve box 2. The outlet 5 is made to correspond to each of the primary side and the secondary side, and as shown in FIG. 4, the water supply device piped inside the outlet M1 of the water meter M or downstream of the water meter as shown in FIG. You may accommodate in the inside of N.
In this case, the valve box 2 eliminates the union rod 8 and the taper screw 9, and is formed in the shape of a right circular cylinder with the same outer diameter of the inflow port end 4a and the outflow port end 5a.
The outlet M1 of the water meter M that accommodates the constant ratio pressure reducing valve 1 is formed in a straight tube that is slightly longer than the entire length of the valve box 2. Inside the outlet M1, there is an inlet end 4a of the valve box 2 at the back. An annular step portion M2 having a slightly smaller diameter is formed with a reduced diameter, the inlet end 4a of the valve box 2 is brought into contact with the annular step portion M2, and the inner periphery of the outlet M1 side end corresponding to the outlet end portion 5a is A retaining ring 21 is provided in contact with the outlet end portion 5a so as to prevent the valve box 2 and the piston 3 from being pulled out.
An air passage M3 that communicates the air vent 22 with the outside is provided on the side of the outlet M1, and the air passage between the air passage M3 and the air vent 22 is provided before and after the air passage port M4 inside the outlet M1. A sealing member (O-ring) G that retains properties is provided.
The water appliance N piped downstream of the water meter is a valve such as a water pipe or a stop cock, and the constant pressure reducing valve 1 is provided in the outlet or inlet of the straight water pipe or in the valve. It is housed inside a straight tubular entrance.
Since the configuration in which the constant ratio pressure reducing valve 1 is accommodated in the outlet of the water pipe is the same as the configuration accommodated in the outlet M1 of the water meter M, the illustration is omitted, and the constant ratio pressure reducing valve 1 is installed in the inlet of the water pipe or valve. The accommodated configuration is shown in FIG. 5, but the basic configuration is the same as described above.
That is, the inside of the inlet N1 of the water supply device (water pipe or valve) N is in contact with the outlet end portion 5a of the valve box 2 at the back thereof, and is replaced with a retaining ring 21 provided at the stroke end of the piston 3. A diameter of the stepped portion N2 is reduced, and a retaining ring R is provided on the inner periphery of the inlet N1 side end corresponding to the inlet end 4a so as to contact the inlet end 4a and prevent the valve box 2 from being removed. In the same manner as described above, an air passage N3 that communicates the air vent 22 with the outside is provided at the side of the inlet N1, and seal members G are provided around the air passage N4 inside the inlet N1.
[0009]
Next, the operation of the constant ratio pressure reducing valve 1 according to the present invention will be described.
In the constant ratio pressure reducing valve 1, the shape of the piston 3 is such that the acting force in the primary direction acting on the valve portion 11 of the piston 3 by utilizing the difference in the diameter between the inlet 4 and the outlet 5 and the hollow portion of the piston 3. The fluid acting force in the secondary direction acting on the 12 side (the product of the pressure receiving area of the secondary side pressure on the hollow portion 12 side (corresponding to the area S _{2 of the} outlet 5) and the secondary pressure P ₂ ) is balanced. It is configured.
The acting force in the primary direction is the product of the primary pressure receiving area of the valve part 11 (corresponding to the area S _{1 of the} inlet 4) and the primary pressure P ₁ , the secondary pressure receiving area of the valve part 11 ( The product of the area (S ₃ −S ₁ ) of the annular surface excluding the pressure receiving area S ₁ of the primary pressure from the total area S ₃ of the valve part 11) and the secondary pressure P ₂ , and the U packings 14, 16 This is the sum of the frictional resistance α of the piston 3 based on the above.
That is, S ₁ P ₁ + (S ₃ −S ₁ ) P ₂ + α = S ₂ P ₂
P ₂ = (S ₁ P ₁ + α) / (S ₂ − (S ₃ −S ₁ )) is obtained.
Therefore, the secondary pressure P ₂ is a pressure obtained by reducing the primary pressure P ₁ to a value determined by the pressure receiving area (S ₂ − (S ₃ −S ₁ )), the pressure receiving area S ₁ , and the frictional resistance α. Become.
As described above, since the inlet 4 is set to have a smaller diameter than the outlet 5, the area S _{1 of the} inlet 4 is smaller than the area S _{2 of the} outlet 5 (S ₁ <S ₂ ). Since the area (S ₃ −S ₁ ) of the annular surface is set by the area S ₁ of the inlet 4 (where S ₃ ≦ S ₂ ), the secondary pressure is the area S ₁ ( It can be set by changing the aperture.
Accordingly, when the secondary pressure is a predetermined pressure, the constant ratio pressure reducing valve 1 is in the closed state with the valve portion 11 seated on the valve seat 6, and by opening the water tap and using water, When the side pressure falls below a predetermined pressure, the valve portion 11 is opened away from the valve seat 6 due to the primary pressure, and the primary fluid passes through the inlet 4, the gap 15, the water inlet 19 and the hollow portion 12 to the secondary side. Flow into.
[0010]
The flow of the pressure fluid (tap water) in the valve open state will be described in detail. The pressure fluid flowing into the gap 15 from the inlet 4 generates a flow along the bus line of the piston 3, and the water inlet 19 is formed from the outer periphery of the piston 3. Since it is in the depressed position (on the depression surface 18), the pressure fluid flowing along the generatrix of the piston 3 flows into the water inlet 19 along the annular recess.
Since the cross-sectional area of the gap 15 and the total area Sa of the water inlet 19 are larger than the area S _{1 of the} inlet 4, a passage area without stagnation of the pressure fluid can be secured, and the total area Sa of the water inlet 19 is In addition, the area of the recessed surface 18 excluding the area Sa (Sb−Sa) is larger, the opening degree of the water inlet 19 with respect to the recessed surface 18 is larger, and each water outlet 19 is narrow over the entire circumference of the recessed surface 18. Therefore, the flow flowing into the water flow port 19 is larger than the flow blocked by the space L, and the pressure loss of the flow of the pressure fluid flowing into the water flow port 19 as a whole is small. A large passage flow rate of the water port 19 is secured.
In the conventional constant ratio pressure reducing valve a (hereinafter referred to as conventional product a), the total area Sx of the water inlet i is larger than the area Sz of the inlet 4, but the diameter of the water inlet i is the width. The total area of the water inlet i from the area (Sy−Sx) of the annular surface on the piston circumference (the surface between the alternate long and short dash lines corresponding to the depression surface 18 in FIG. 6) minus the total area Sx of the water inlet i Since Sx is small and the distance L1 between the adjacent water inlets i is larger than that of the constant ratio pressure reducing valve 1 of the present invention, the flow is blocked by the distance L1 between the water inlets i rather than the flow of the fluid flowing into the water inlet i. As a result, the pressure loss of the flow of the pressure fluid flowing into the water inlet i increases as a whole, and the passage flow rate through the water inlet i cannot be ensured more than the constant pressure reducing valve 1 of the present invention.
In addition, the pressure fluid flowing into the water flow port 19 is not perpendicular to the flow direction (corresponding to the axial direction of the valve box 2) as in the conventional product a, but to the hollow portion 12 at an acute angle with respect to the axial line. Because of the communication, the resistance to the flow of pressure fluid is smaller than that of the conventional product a.
Then, the pressure fluid that passes through each water flow port 19 and flows into the hollow portion 12 flows as if it does not peel along the slope inclined continuously toward the center of the piston 3 from the outlet of the water flow port 19, as if Since a flow similar to a fluid that flows smoothly along the surface of the blades is generated and then merged, the pressure fluid of a stable flow that hardly generates a negative pressure at the time of the flow flows downstream.
On the other hand, in the conventional product a, the pressure fluid flowing into the hollow portion f from the water passage i collides with and violently collides in the hollow portion f because the back surface of the valve portion e is flat along the water passage i. As a result, a negative pressure is generated at the center of the back surface of the valve part e at the time of merging, and the pressure loss of the flow of the pressurized fluid increases and flows downstream.
As described above, the constant ratio pressure reducing valve 1 of the present invention generally has a small pressure loss of the pressure fluid when the valve is opened compared to the conventional product a, and a stable flow rate is ensured.
When the water faucet is closed after the water is used, the piston 3 is pushed back to the primary side as the secondary pressure increases, and the valve is closed when the secondary pressure reaches a predetermined pressure.
[0011]
【The invention's effect】
In short, in the present invention, the valve portion 11 for opening and closing the inlet 4 is provided in the cylindrical valve box 2 provided with the inlet 4 and the outlet 5 having a diameter larger than that of the inlet 4 at each end. A piston 3 provided at one end and provided with a hollow portion 12 having the other end opened to the outlet 5 is slidably inserted, and a sectional area around the one end of the piston 3 is an area S _{1 of the} inlet 4. Since a larger gap 15 with the inner wall of the valve box 2 is provided, and a plurality of water inlets 19 communicating with the hollow portion 12 are opened on the peripheral wall of the piston 3 always facing the inner wall of the valve box 2 through the gap 15. Since the secondary pressure P ₂ can be reduced to a predetermined ratio with respect to the primary pressure P ₁ , by changing the area S ₁ (caliber) of the inlet 4 without changing the diameter of the valve box 2, the high pressure The secondary side pressure in each level of the building can be set to the same, and the valve box 2 with the short outer diameter and the same axial diameter as the water pipe is used. The constant ratio pressure reducing valve 1 can be easily installed in a small installation space.
In addition, each water inlet 19 is provided on an annular recessed surface 18 having the same diameter as the water inlet 19 provided in the circumferential wall of the piston 3 so that it flows into the gap 15 from the inlet 4 when the valve is opened. Thus, the flow of the pressure fluid along the bus line of the piston 3 is smoothly guided to the depression surface 18 where the water passage 19 is formed, and the pressure loss of the fluid until reaching the water passage 19 can be reduced, and the depression The water inlet 19 formed on the surface 18 is not perpendicular to the axis as in the prior art, but communicates with the hollow portion 12 obliquely toward the outlet 5 with an acute angle with respect to the axis, so that from the primary side to the secondary side. It is possible to maintain a flow that is more in the direction of the flow, reduce the pressure loss of the fluid from the water flow port 19 to the hollow portion 12, and maintain a flow with a small pressure loss as a whole.
Further, the cross-sectional area of the gap 15 and the total area Sa of the water inlet 19 are set to be larger than the area S _{1 of the} inlet 4, so that a passage area without stagnation of the pressure fluid can be secured and the total area of the water inlet 19 Sa can be made larger than the area of the depressed surface 18 excluding the area Sa (Sb−Sa), and the degree of opening of the water inlet 19 with respect to the depressed surface 18 can be increased. Since the gaps are adjacent to each other with a narrow interval L over the circumference, the flow flowing into the water inlet 19 can be more than the flow blocked by the interval L, and the flow of the pressure fluid flowing into the water inlet 19 as a whole can be increased. The pressure loss is small and a large flow rate through the water inlet 19 can be secured.
As described above, according to the present invention, a flow path (inlet 4, gap 15, water inlet 19, hollow portion 12, and outlet 5) having a small pressure loss can be configured as a whole, so that a desired flow rate can be secured. simply by setting the area S ₁ of the inlet 4, it is possible to set the secondary pressure of each layer of the high-rise building to the same, can provide a stable flow rate.
Therefore, even if the valve box 2 is formed to have a slidable outer diameter in the insertion hole 7a of the union nut 7 and the distance between the water meter and the downstream water distribution pipe is short, the union nut 7 is connected to the valve box 2 By sliding back and forth above, it is possible to easily attach the constant ratio pressure reducing valve 1 capable of ensuring a stable flow rate that could not be expected with the conventional product a.
[0012]
In the piston 3, a substantially funnel-shaped concave surface portion 20 that is inclined toward the center of the piston 3 is formed on the back surface of the valve portion 11 continuously to the outlet 19 a of the water inlet 19. pressure fluid flowing into 12 be peeled off along the inclined surface of the concave portion 20 continuously from the outlet 19a of the passage Minakuchi 19 inclined towards the outlet 5 with a acute angle to the axis to toward tilted about the piston 3 As the conventional product a, it is difficult to generate a negative pressure, and a flow with a small pressure loss is generated, and combined with the above effect, the pressure loss as a whole is reduced. Thus, a more stable flow rate can be secured.
[0013]
The valve box 2 in which the inlet 4 and the outlet 5 are respectively associated with the primary side and the secondary side is accommodated inside the outlet M1 of the water meter M, or the valve box 2 is piped on the secondary side of the water meter Since the water meter M or the water appliance N is provided with the above performance, it is not necessary to connect the constant pressure reducing valve 1 between the water meter and the downstream water pipe. The practical effect is significant, such as reducing the labor of piping work and improving the work efficiency.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a closed state of a water ratio constant pressure reducing valve.
FIG. 2 is a cross-sectional view showing a valve open state.
3 is a cross-sectional view taken along the line AA in FIG.
FIG. 4 is a cross-sectional view showing a state in which a constant water pressure reducing valve for water supply is housed inside the outlet of a water meter.
FIG. 5 is a cross-sectional view showing a state in which a constant water pressure reducing valve for water supply is housed inside an inlet of a water supply device.
FIG. 6 is a cross-sectional view showing a closed state of a conventional constant ratio pressure reducing valve for water supply.
FIG. 7 is a cross-sectional view showing a valve open state.
8 is a cross-sectional view taken along the line BB in FIG.
[Explanation of symbols]
2 Valve box 3 Piston 4 Inlet 5 Outlet 7 Union nut
7a Insertion hole
11 Valve
12 Hollow part
15 gap
18 Recessed surface
19 Water outlet
19a Exit
20 Concave part L Narrow interval M Water meter M1 Exit N Water supply
S ₁ Inlet area
Total area of Sa outlet
Sb-Sa Area of the depressed surface excluding the total area of the water inlet

Claims

A cylindrical valve box having an inlet and an outlet set larger in diameter than the inlet at each end, a valve portion for opening and closing the inlet is provided at one end, and the other end is an outlet. A piston provided with an open hollow part is slidably inserted, and a gap with the inner wall of the valve box whose cross-sectional area is set larger than the area of the inlet is provided around one end of the piston. An annular recessed surface is recessed in the piston peripheral wall facing the inner wall of the valve box. The recessed surface communicates with the hollow portion, and a water passage having the same diameter as the width of the recessed surface flows at an acute angle with respect to the axis. A plurality of outlets are opened obliquely at narrow intervals, and the total area of the water inlet is set larger than both the area of the inlet and the area of the depressed surface excluding the total area of the water inlet. A constant pressure reducing valve for water supply.

2. The constant ratio for water supply according to claim 1, wherein a substantially funnel-shaped concave surface portion inclined toward the center of the piston is provided on the back surface of the valve portion continuously from the outlet of the water passage. Pressure reducing valve.

3. The water ratio constant pressure reducing valve according to claim 1, wherein a valve box in which the inlet and the outlet correspond to the primary side and the secondary side is accommodated inside the outlet of the water meter.

The valve box which made the inflow port and the outflow port correspond to each of a primary side and a secondary side was accommodated in the inside of the water appliance piped by the secondary side of a water meter, The Claim 1 or 2 characterized by the above-mentioned. Constant pressure reducing valve for water supply.