JP4105525B2

JP4105525B2 - Differential pressure valve

Info

Publication number: JP4105525B2
Application number: JP2002311564A
Authority: JP
Inventors: 貞武伊勢; 秀柳澤
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2002-08-01
Filing date: 2002-10-25
Publication date: 2008-06-25
Anticipated expiration: 2022-10-25
Also published as: JP2004138228A

Description

【０００１】
【発明の属する技術分野】
本発明は、空調機の冷凍サイクル等において用いられる差圧弁に関する。
【０００２】
【従来の技術】
空調機の冷凍サイクル等において用いられる冷媒圧力調整弁と同様に用いられている差圧弁は、流体の上流（高圧）側と下流（低圧）側との両流体間において、所定の圧力（バネ荷重相当圧分）以上の圧力差がある場合に限って流体を流すものである（特許文献１）が、従来の直動式として使用するものは、低圧側からのパイロット配管が必要となるなど、構造が複雑であるばかりでなく、長期稼動等に依ってパイロット配管の溶接部分の冷媒漏れなどトラブルが発生することがあった。
【特許文献１】
特開平０９−１１３０７１号公報（特に「特許請求の範囲」及び図１参照）
【０００３】
【発明が解決しようとする課題】
本発明の課題は、上記従来技術の問題点を解消することにあり、空調機の冷凍サイクル等において用いる差圧弁において、構造が簡単・コンパクトで、しかも廉価な差圧弁を提供することにある。
【０００４】
【課題を解決するための手段】
上記課題を解決すべく、本発明は、以下の手段を採用した。即ち、
請求項１記載の差圧弁は、外枠パイプの一端に流体入口が形成され、該外枠パイプの他端に流体出口が形成され、前記外枠パイプ内に筒状弁シートが挿入されるとともに該筒状弁シート内に、流体の差圧を感知する感圧部と、該感圧部で感知された差圧により流体の流量を制御する絞り部と、該絞り部による制御量を任意の値に設定する調節部とが設けられ、前記筒状弁シートと前記流体入口との間に高圧側空間部が形成されるとともに前記筒状弁シートと前記流体出口との間に低圧側空間部が形成され、前記感圧部は、前記低圧側空間部に連通する感圧部低圧側空間と、該感圧部低圧側空間と前記高圧側空間部との間で摺動可能なピストンとを備え、前記絞り部は、前記筒状弁シートに形成された弁孔と、該弁孔を貫通するとともに流体の流れ方向に摺動可能な弁体とを備え、該弁体は、一端部に前記ピストンが固定されるとともに中間部に弁部が形成され、該弁部は、前記弁孔の下流側に配置されるとともに前記弁孔の弁座部に接離する円錐状の部分と、その下流側に設けられた径大部と、該径大部に設けられるとともに前記低圧側空間部と前記感圧部低圧側空間とを連通させる下横穴とを有し、前記筒状弁シートにおける前記弁孔の下流側の部位に前記弁孔よりも径大の弁部形成部が設けられ、該弁部形成部に前記弁体の径大部が配置されており、前記弁部形成部と前記弁体の径大部とで形成される流路の断面積は、前記弁部と前記弁座部とで形成される最大開口面積以上であり、且つ前記弁孔の流路の断面積より小さいことを特徴とする。
【０００５】
請求項２記載の差圧弁は、請求項１記載の差圧弁において、前記筒状弁シート部が前記外枠パイプ内にかしめ固定されるとともに前記外枠パイプの両端部が継手形状に絞り成形されていることを特徴とする。
【０００６】
請求項３記載の差圧弁は、請求項１又は請求項２記載の差圧弁において、前記弁体における前記筒状弁シートに摺動可能に支持される部分の外径と前記弁孔の内径とを略同一としたことを特徴とする。
請求項４記載の差圧弁は、外枠パイプの一端に流体入口が形成され、該外枠パイプの他端に流体出口が形成され、前記外枠内に、シリンダ状筒体及びその上流側に連結固定されたバネケースが挿入され、前記バネケースと前記流体入口との間に高圧側空間部が形成され、前記シリンダ状筒体と前記流体出口との間に低圧側空間部が形成され、前記シリンダ状筒体内に、流体の差圧を感知する感圧部と、該感圧部で感知された差圧により流体の流量を制御する絞り部とが設けられ、前記バネケース内に、前記絞り部による制御量を任意の値に設定する調節部が設けられ、前記感圧部は、前記シリンダ状筒体内に摺動可能に配置されたピストンと、該ピストンの下流側に形成され前記高圧側空間部に連通する高圧感圧室と、前記ピストンの上流側に形成され前記低圧側空間部に連通する低圧感圧室とを備え、前記絞り部は、前記ピストンにおける前記高圧感圧室側の部位に設けられた弁体と、前記シリンダ状筒体に設けられ前記高圧感圧室と前記低圧側空間部とを連通する弁座孔を有する弁座とを備えることを特徴とする。
【０００７】
請求項５記載の差圧弁は、請求項４記載の差圧弁において、前記シリンダ状筒体と前記バネケースとの連結体が前記外枠パイプ内にかしめ固定されるとともに前記外枠パイプの両端部が継手形状に絞り形成されていることを特徴とする。
請求項６記載の差圧弁は、請求項４又は請求項５記載の差圧弁において、前記シリンダ状筒体に前記低圧感圧室と前記低圧側空間部とを連通する低圧導入孔が設けられたことを特徴とする。
【０００８】
請求項７記載の差圧弁は、請求項４乃至６のいずれかに記載の差圧弁において、前記ピストンに前記高圧感圧室と前記高圧側空間部とを連通する高圧導入孔が設けられたことを特徴とする。
請求項８記載の差圧弁は、請求項４乃至７のいずれかに記載の差圧弁において、前記弁体及び前記弁座はステンレススチールで形成され、前記弁体は前記ピストンに圧入されるとともに前記弁座は前記シリンダ状筒体に圧入されていることを特徴とする。
【００１３】
【発明の実施の形態】
【実施例１】
実施例１について、図面を用いて説明する。なお、図１はその縦断面図、図２は図１におけるＤ部詳細図である。なお、以下、図面に従って説明するが、上・下・左・右という表現は、図面の記載に伴うものであり、実際の位置関係とは、必ずしも一致するものではない。
【００１４】
先ず、外枠パイプ１０について説明する。
実施例１に係る差圧弁は、図１に示すように、全体として円筒状の外枠パイプ１０と、外枠パイプ１０より短く、外枠パイプ１０の中に挿入・固定される筒状弁シート２０と、該筒状弁シート２０の中に配置される感圧部Ａ、絞り部Ｂ及び調節部Ｃからなる。
また、外枠パイプ１０の一端部の流体入口１１近傍には、高圧側空間部Ｐｈが形成され、外枠パイプ１０の他端部の流体出口１２近傍には、低圧側空間部Ｐｌが形成される。なお、符号１３はカシメ部である。
【００１５】
次に、筒状弁シート２０について説明する。
筒状弁シート２０は、図２に示すように、全体として略円筒状となっており、その高圧側空間部Ｐｈ側の外径は、所定長さだけ径小部２０ａとして形成されており、該径小部２０ａ以外の部分は、前記外枠パイプ１０の内径より若干小さい外径となっている。また、前記外枠パイプ１０の内径より若干小さい外径部分における径小部２０ａ寄りには、カシメ受溝２９が形成されている。そして、上記径小部２０ａと外枠パイプ１０との隙間には流路１４が形成され、高圧側空間部Ｐｈと後述の側孔２４とを連通している。
【００１６】
また、筒状弁シート２０の内部には、ピストン４０が内装・支持される径大部２０ｂと、該径大部２０ｂより若干小径の感圧部低圧空間２１が形成される低圧空間形成部２０ｃと、弁体支持部２２ａ及び該弁体支持部２２ａにより形成される弁体支持孔２２と、弁室２０ｆと、弁孔２３と、前記弁孔２３より径大の弁部形成部２０ｄと、更に、バネ室形成部２０ｅと、が連続的に形成される。
【００１７】
また、上記弁体支持部２２ａの下部には、複数の側孔２４が形成され、側孔２４は前記弁室２０ｆに開口しており、したがって、高圧側空間部Ｐｈ、流路１４、側孔２４、弁室２０ｆ、及び弁孔２３は順次連通している。また、弁孔２３は、弁部３５が「開」のときにその下部の低圧側空間部Ｐｌに連通する。
そして、径大部２０ｂと低圧空間形成部２０ｃでは感圧部Ａが形成され、弁体支持孔２２では弁体３０が支持され、弁孔２３では絞り部Ｂが形成され、バネ室形成部２０ｅでは調節部Ｃが形成される。なお、側孔２４は一個形成しても良いのは勿論である。
【００１８】
次に、弁体３０について説明する。
特に図２に示すように、上記筒状弁シート２０の軸線部分の孔部に沿って棒状の弁体３０が配置される。この弁体３０は、上記筒状弁シート２０の径大部２０ｂから、低圧空間形成部２０ｃ、弁体支持部２２ａ、弁室２０ｆ、弁孔２３、弁部形成部２０ｄを貫通してバネ室２５まで延設されている。そして、筒状弁シート２０の径大部２０ｂ部分では、ピストン４０が弁体３０に一体に装着されている。この装着に当たっては、弁体３０にはカシメ部３１が形成されている。
【００１９】
また、筒状弁シート２０の低圧空間形成部２０ｃ部分に連通する上横孔３３が弁体３０の直径方向に穿設され、弁体３０の長さ方向の軸心部に形成されている低圧導入孔３２に連通している。
また、弁体３０の弁体支持部２２ａに対応する部分は平坦な柱状となっており、この部分の外径は弁孔２３の内径と略同一径として形成される。これは弁体３０に流体によるスラスト荷重を発生させないためである。また、弁体３０の弁室２０ｆから弁孔２３に至る部分は径小部３６として形成される。また、この径小部３６から下方には下方が径大となるテーパー形状の弁部３５が形成され、筒状弁シート２０の弁部形成部２０ｄに位置する。また、弁体３０のバネ室２５部分には、下横孔３４が弁体３０の直径方向に穿設され、バネ室２５に開口していると共に低圧導入孔３２に連通している。また、弁体３０の下端部はバネ受け５２に当接し、バネ受け５２はバネ５３により弾持されている。
したがって、低圧側空間部Ｐｌは、下横孔３４、低圧導入孔３２、及び上横孔３３を通って感圧部低圧空間２１に常時連通していることになる。
【００２０】
次に、感圧部Ａについて説明する。
筒状弁シート２０の径大部２０ｂの内には所定幅で上下に摺動可能にピストン４０が配置されている。ピストン４０は所定厚みの円盤からなり、その外周に形成されたリング溝にはシール用のＯリング４１が配置されている。また、その中心部に穿設された孔には、上記弁体３０の上端部が嵌入されてカシメ部３１が形成されている。
また、上記ピストン４０の上面は、高圧側空間部Ｐｈに面しており、ピストン４０の下面と弁体支持部２２ａとの間の低圧空間形成部２０ｃに感圧部低圧空間２１が形成されている。なお、前記のように、感圧部低圧空間２１は、上横孔３３、低圧導入孔３２及び下横孔３４を通じて低圧側空間部Ｐｌの流体圧が導かれている。
【００２１】
そして、ピストン４０は、
高圧側空間部Ｐｈの流体圧＞感圧部低圧空間２１の流体圧＋バネ５３のバネ荷重相当圧、のときは下動し、
高圧側空間部Ｐｈの流体圧＜感圧部低圧空間２１の流体圧＋バネ５３の荷重相当圧、のときは上動し、弁部３５は開弁することになる。
この差圧によるピストン４０の上下動によりピストン４０と一体の弁体３０も、弁体支持部２２ａに支持された状態で筒状弁シート２０の弁体支持孔２２内を摺動し、上下動することになる。
【００２２】
絞り部Ｂは、弁体３０の径小部３６と弁部３５、及び、筒状弁シート２０側の弁孔２３、弁座部２３ａ及び弁部形成部２０ｄにより構成され、弁部３５と弁座部２３ａにて形成される開口面積が差圧に応答して増減し、流量が絞られて変化する。
【００２３】
次に、調節部Ｃについて説明する。
弁体３０の下端部は、バネ受け５２のバネ受け孔５２ａに当接しており、バネ受け５２は、バネ５３により絞り部Ｂ側に弾持されている。またバネ５３は、図１に示すように、筒状弁シート２０の下部を構成するスカート部２６の雌ネジ受部２７に螺合され通孔５１を有する調節ネジ５０によって支持されている。したがって、調節ネジ５０の回転によって、バネ受け５２に対するバネ５３の弾発力を調節することができる。この弾発力の調節は、差圧量の調節となる。
【００２４】
上記実施例１の差圧弁を構成するに当たっては、先ず、筒状弁シート２０の弁体支持部２２ａにＯリング２８を装着して、筒状弁シート２０内に弁体３０を挿入させ、Ｏリング４１を装着したピストン４０を、筒状弁シート２０上端部に上方から弁体３０と共に嵌合させ、弁体３０の下端部を治具にて受けて、弁体３０の上端部をかしめてピストン４０と固定する。そして、バネ受け５２を弁体３０の下端部に当接した上、バネ受け５２にバネ５３をあてがい、調節ネジ５０を雌ネジ受部２７に螺合する。
【００２５】
上記手段によれば、きわめて簡単で、コンパクトな差圧弁を得ることができる。
【００２６】
かかる構成により、差圧によるピストン４０の上下動に応じて弁体３０が上下動し、弁部３５と弁座部２３ａにて形成される開口面積が可変され、流量が絞られて変化することになる。
【００２７】
また、所定量の差圧以上の差圧が発生した場合は、感圧部Ａにおけるピストン４０の下動により、絞り部Ｂにおいて弁体３０は下動し、所定量の差圧になるまで絞り部Ｂで流量を増加させる。逆に、所定量の差圧以下の差圧が発生した場合は、感圧部Ａにおけるピストン４０の上動により、絞り部Ｂにおいて弁体３０は上動し、所定量の差圧になるまで絞り部Ｂで流量を減少・停止させる。
なお、上記実施例１において、低圧側空間部Ｐｌと感圧部低圧空間２１との連通手段として、下横孔３４、低圧導入孔３２及び上横孔３３を形成したが、これら下横孔３４、低圧導入孔３２及び上横孔３３を設けず、筒状弁シート２０内に別途、低圧側空間部Ｐｌと感圧部低圧空間２１とを直接結ぶ連通路（図示せず）を設けてもよい。
【００２８】
【実施例２】
次に、本発明の実施例２について説明する。図３は、その縦断面図、図４は、図３のＤ'部の詳細図である。実施例２の説明に当たって、実施例１と同一の構成部分には、同一符号を付してその構成の説明を省略する。
実施例１は上記弁孔２３の流体下流側に該弁孔２３より径大の弁部形成部２０ｄが形成されているが、実施例２においては、この弁部形成部２０ｄに位置する上記弁部３５の径大部３７に、一個もしくは複数個の下横孔３４ａを弁部形成部２０ｄと低圧導入孔３２を連通するように設ける。
また、更に弁部形成部２０ｄと弁体３０の径大部３７で形成される流路面積Ｓ（＝弁部形成部２０ｄの横断面積−径大部３７の横断面積）を、弁座部２３ａと弁部３５で形成される最大開口面積ｓ以上とし、かつ、弁孔２３の流路面積ｍ（＝弁孔２３の横断面積−小径部３６の横断面積）より小さく形成される。
通常、流出量が増加するにつれ弁部３５前後の圧力差も大きくなると共に、設定差圧値に対する圧力変化量が増加する傾向にあるが、差圧弁に於いては、流量の変化に対する弁部３５前後の圧力差の変化を最小限に抑える必要があることから、本実施例２においては、弁体３０の径大部３７に一個若しくは複数個の小径の下横孔３４ａを設け、更に、弁部形成部２０ｄと弁体３０の径大部３７で形成される流路面積Ｓを、弁座部２３ａで形成される最大開口面積ｓ以上で、かつ弁孔２３の流路面積ｍよりも小さくすることにより、冷媒の流速を高め、ベルヌーイの原理により低圧空間形成部２０ｃ内の圧力が実際の圧力より低くなり、その結果、大流量流出時に於いても弁開度を大きく、圧力変化を小さくすることが可能となる。
【実施例３】
次に、本発明の実施例３について説明する。図５は、図１のＤ部に相当する実施例３の詳細図である。実施例３の説明に当たって、実施例１と同一の構成部分には、同一符号を付してその構成の説明を省略する。実施例３においても外枠パイプ１０の形状は実施例１と略同一である。
【００２９】
次に、筒状弁シート２０'について説明する。
筒状弁シート２０'は全体として円筒状となっており、その外形は、全長にわたって均一径であるが、その中央部にはカシメ受溝２９が形成されている。また、筒状弁シート２０'の内部には、ピストン４０'を内装・支持させる径大部２０'ｂと、該径大部２０'ｂより若干小径の弁室２０'ｆと、更に、バネ室形成部２０'ｅと、が連続的に形成される。そして、径大部２０'ｂでは感圧部Ａ'が形成され、弁室２０'ｆでは絞り部Ｂ'が形成され、バネ室形成部２０'ｅでは調節部Ｃ'が形成される。
【００３０】
また、筒状弁シート２０'の上下方向の中間位置には支持筒２５ａが一体に設けられている。この支持筒２５ａは後述のピストン４０'側の延伸軸部４０'ａを支持させるものである。また、この支持筒２５ａの内壁下部には、支持筒周溝２５ｃが形成されると共に、この支持筒周溝２５ｃと支持筒２５ａとの外面との間には支持筒側孔２５ｂが形成されている。
【００３１】
次に、感圧部Ａ'について説明する。
筒状弁シート２０'の径大部２０'ｂの内壁には所定幅で上下に摺動可能にピストン４０'が配置されている。ピストン４０'は所定厚みの円盤からなり、その外周に形成されたリング溝にはＯリング４１が配置されている。また、その中心部は所定長さで下方に垂下する延伸軸部４０'ａが形成され、その下端はバネ受け５２を介してバネ５３で上方へ弾持されている。また、ピストン４０'の筒状弁シート２０'に対する上限位置は、筒状弁シート２０'に固定されているストッパ６０により制限されている。
【００３２】
また、上記ピストン４０'の上面は、高圧側空間部Ｐｈに面しており、ピストン４０'の下面には、弁室２０'ｆで低圧側空間部Ｐｌの流体圧が導かれている。
そして、ピストン４０'は、実施例１と同様に、
高圧側空間部Ｐｈの流体圧＞低圧側空間部Ｐｌの流体圧＋バネ荷重相当圧、
のときは下動し、
高圧側空間部Ｐｈの流体圧＜低圧側空間部Ｐｌの流体圧＋バネ荷重相当圧、のときは上動することになる。このピストン４０'の上下動はピストン４０'と一体の延伸軸部４０'ａも支持筒２５ａに支持された状態で上下動することになる。
【００３３】
上記延伸軸部４０'ａ及び支持筒２５ａが絞り部Ｂ'を構成する。上記ピストン４０'の中心部には、延伸軸部４０'ａの中心部まで連続して高圧導入孔４２が形成され、この高圧導入孔４２の下端部近傍には高圧側孔４３が側方に開放されるように形成されている。したがって、高圧側空間部Ｐｈは、高圧導入孔４２を介して、高圧側孔４３まで常に連通していることになる。
また、上記支持筒２５ａには、前記のように支持筒側孔２５ｂが形成されている。そして、高圧側孔４３が支持筒周溝２５ｃと重なり、流路が形成されたときのみ高圧側空間部Ｐｈから低圧側空間部Ｐｌに冷媒が流れることになる。
なお、バネ５３を含む調節部Ｃ'の構成は、実施例１と略同一である。
【００３４】
上記実施例３の差圧弁の使用手段は、実施例１と同じであるので、共通部分については説明を省略し、相違する部分のみ説明する。
実施例３の差圧弁において、先ず、差圧が所定量以下の場合は、ピストン４０'は下動せず、高圧側孔４３が支持筒２５ａ側の支持筒周溝２５ｃと重なることはない。したがって、冷媒が支持筒２５ａの内壁から弁室２０'ｆ内に流出することはない。
【００３５】
また、所定量の差圧が発生した場合は、感圧部Ａにおけるピストン４０'の下動により、絞り部Ｂ'において、延伸軸部４０'ａは下動し、冷媒を弁室２０'ｆに流す。また、所定差圧以下になった場合は、感圧部Ａ'におけるピストン４０'の上動により、絞り部Ｂ'において弁体３０は上動し、所定量の差圧になるまで絞り部Ｂ'で流量を減少・停止させる。
したがって、ピストン４０'が所定位置（差圧が少ない状態での位置）では、支持筒２５ａの内壁により弁室２０'ｆ内に流出することはないが、ピストン４０'が所定位置より、差圧により下がってくると、高圧側孔４３が支持筒周溝２５ｃに重なり、支持筒側溝２５ｂから流体は流出する。そして、その重なりが大きいほど流出量が増加する。
【００３６】
【実施例４】
次に、実施例４について図面を用いて説明する。図６はその縦断面図、図７は図６におけるＤ"部詳細図である。
先ず、外枠パイプ１１０について説明する。
実施例３に係る差圧弁は、図６に示すように、全体として円筒状の金属製、例えば銅製の外枠パイプ１１０と、外枠パイプ１１０より短く、外枠パイプ１１０の中に挿入・固定されるシリンダ状筒体１２０及びバネケース１３０と、該シリンダ状筒体１２０及びバネケース１３０の中に配置される感圧部Ａ"、絞り部Ｂ"及び調節部Ｃ"からなる。
また、外枠パイプ１１０の一端部の流体入口１１１近傍には、高圧側空間部Ｐｈが形成され、外枠パイプ１１０の他端部の流体出口１１２近傍には、低圧側空間部Ｐｌが形成される。更に、外枠パイプ１１０の中間部にはカシメ部１１３が形成される。
【００３７】
次に、シリンダ状筒体１２０について説明する。
外枠パイプ１１０内に配置されるシリンダ状筒体１２０は、図６，７に示すように、全体として略円筒状に形成されており、上記カシメ部１１３の内面に相当するシリンダ状筒体１２０の外周面部分には、カシメ用凹部１２１が形成され、シリンダ状筒体１２０の内面は、後述のバネケース１３０を装着するためのバネケース装着部１２２が形成される。なお、該バネケース装着部１２２の上端部には、後述のバネケース１３０側の径小部１３１が嵌合された後、押し込むようにカシメることでカシメ部１２２ａが形成されている。
【００３８】
また、シリンダ状筒体１２０の下部は所定の厚みで形成され、該所定の厚み部分の内部には、上下に複数の低圧導入孔１２４が形成される。該低圧導入孔１２４の下部は低圧側空間部Ｐｌに連通しており、その上部は後述のシリンダ状筒体１２０内に形成される低圧感圧室１２８に連通している。
そして、シリンダ状筒体１２０の下端部には、弁座支持部１２５が形成され、該弁座支持部１２５の中心部には、例えばステンレススチール製の弁座１２６が圧入により装着される。該弁座１２６には弁座孔１２７が形成されている。
【００３９】
バネケース１３０は、その下部の径小部１３１が前記シリンダ状筒体１２０のバネケース装着部１２２に嵌合される。上記径小部１３１の外周には、シリンダ状筒体１２０側との間に配置されるＯリング１２３ａを嵌合するリング状のリング溝１２３が形成される。また、この径小部１３１の内側は、Ｏリング１３３が介装されており、後述のピストン１４０を支持するピストン支持部１３２となる。
バネケース１３０の上部は外枠パイプ１１０の内周面に嵌合され、その内面にはバネ室１３４が形成される。また、バネケース１３０の上端部内周には、雌ネジ部１３５が形成され、該雌ネジ部１３５には調節ネジ１５０が螺合されている。
調節ネジ１５０は、その中心部に通孔１５１が形成され、上方の高圧側空間部Ｐｈとバネ室１３４とを連通している。
【００４０】
次に、感圧部Ａ"について説明する。感圧部Ａ"は、ピストン１４０の下部に形成される。ピストン１４０は全体として上下に長い異径の円柱状体として形成され、上方部分は小径のピストン軸部１４１となり、下方は大径の感圧部１４２となる。ピストン軸部１４１は、前記ピストン支持部１３２に上下方向に摺動可能に支持され、また、感圧部１４２はシリンダ状筒体１２０の下部の内周面に上下方向に摺動可能に支持されている。また。感圧部１４２の外周とシリンダ状筒体１２０の内周面との間にはＯリング１４３が介装されている。
【００４１】
また、ピストン１４０の軸心部には、その長さ方向（軸心方向）に高圧導入縦孔１４７が形成され、該高圧導入縦孔１４７と連通してその上部には高圧導入横孔１４６が形成され、該高圧導入横孔１４６の端部はバネ室１３４に開口している。また、高圧導入縦孔１４７の下部には、高圧導入縦孔１４７と連通状態で高圧導入斜孔１４８が形成され、その端部は感圧部１４２の下部の空間に開口している。
【００４２】
したがって、この感圧部１４２の上面の空間部は低圧導入孔１２４によって低圧側空間部Ｐｌと連通し、低圧感圧室１２８が形成され、感圧部１４２の下面の空間部は、高圧導入横孔１４６、高圧導入縦孔１４７及び高圧導入斜孔１４８によって、高圧側空間部Ｐｈと連通し、高圧感圧室１２９が形成される。
また、ピストン１４０の上端部には、内面が球面形状の受け凹部１４５が形成され、該受け凹部１４５の底部にバネ受突部１５２ａがバネ１５３の弾発力により当接し、ユニバーサルジョイントを形成している。この当接状態により、バネ１５３の弾発力や高圧冷媒により、ピストン１４０に偏心荷重が負荷してもピストン１４０には円滑に上下圧として作用する。
【００４３】
絞り部Ｂ"は、感圧部１４２の下部で上記高圧導入縦孔１４７に連続して形成された弁体装着孔１４４に装着されるステンレススチール製の弁体１４９と、前記弁座１２６によって構成される。即ち、弁体１４９は、弁体装着孔１４４への柱状の挿入部１４９aと、円盤状の径大部１４９ｂと、下端の倒立円錐状の突部１４９ｃとからなり、該突部１４９ｃと弁座１２６にて形成される開口面積が差圧に応答して、ピストン１４０が上下することで増減し、流量が絞られて変化する。
【００４４】
ピストン１４０は、
高圧感圧室１２９の流体圧＞低圧感圧室１２８の流体圧＋バネ１５３のバネ荷重相当圧、のときは上動し、弁体１４９は開弁することになる。
高圧感圧室１２９の流体圧＜低圧感圧室１２８の流体圧＋バネ１５３のバネ荷重相当圧、のときは下動し、弁体１４９は閉弁することになる。
【００４５】
次に、調節部Ｃ"について説明する。
上記調節ネジ１５０の下面（バネ室１３４側）とバネ室１３４の下部に配置されるバネ受け１５２との間にはバネ１５３が縮装され、該バネ１５３はバネ受け１５２を下方に押し圧している。該バネ受け１５２は、その上面にバネ受面が形成され、その下面には下端部が球面状となったバネ受突部１５２ａが一体に形成される。この弾発力の調節は、差圧量の調節となる。
【００４６】
上記実施例４の差圧弁の組み付けに当たっては、先ず、シリンダ状筒体１２０の弁座支持部１２５に弁座１２６を装着し、ピストン１４０の弁体装着孔１４４に弁体１４９を装着後、シリンダ状筒体１２０にピストン１４０を嵌合させる。次に、バネケース１３０内に、バネ受け１５２及びバネ１５３をこの順に内装し、調節ネジ１５０を雌ネジ部１３５に螺合する。
そして、前記受け凹部１４５に前記バネ受突部１５２ａを遊嵌させながら、シリンダ状筒体１２０に対してバネケース１３０を装着・固定し一体化する。固定に当たっては、上述のようにバネケース装着部１２２に径小部１３１を嵌合後、カシメ部１２２ａをカシメることで、確実に一体化することができる。
そして、このシリンダ状筒体１２０とバネケース１３０との一体物を外枠パイプ１１０内に嵌入させ、カシメ部１１３とカシメ用凹部１２１との位置を合わせた後、カシメる。上記手段によれば、きわめて簡単で、コンパクトな差圧弁を得ることができる。
【００４７】
かかる構成により、差圧によるピストン１４０の上下動に応じて弁体１４９が上下動し、該弁体１４９と弁座１２６にて形成される開口面積が変更され、流量が絞られて変化することになる。
また、所定量の差圧以上の差圧が発生した場合は、感圧部Ａ"におけるピストン１４０の上動により、絞り部Ｂ"において弁体１４９は上動し、所定量の差圧になるまで絞り部Ｂ"で流量を増加させる。逆に、所定量の差圧以下の差圧のときには、感圧部Ａ"におけるピストン１４０の下動により、絞り部Ｂ"において弁体１４９は下動し、所定量の差圧になるまで絞り部Ｂ"で流量を減少又は停止させる。
【００４８】
特に、実施例４においては、低圧感圧室１２８を高圧導入側に設けることにより、弁体１４９を正弁方向（高圧感圧室１２９側）に設置できるため、微少流量の流量制御が可能となる。
また、シリンダ状筒体１２０にピストン１４０及びバネケース１３０を装着後、シリンダ状筒体１２０上端部１２２ａをカシメてカシメ部とし、バネケース１３０とシリンダ状筒体１２０を一体化することにより、ピストン１４０の上・下に低圧感圧室１２８と高圧感圧室１２９を形成することができ、更に、シリンダ状筒体１２０及びバネケース１３０を一体物とすることで、治具による組み付け作業が容易となり、又、最終組立工程の外枠パイプ１１０への組付けも容易となるため、工数低減を図れる。
【００４９】
更に、実施例４によれば、部品点数を増やすことなく、シリンダ状筒体１２０に孔加工するだけで容易に低圧側空間部Ｐｌの圧力をピストンの感圧部上部の低圧感圧室１２８に導くことができ、また、部品点数を増やすことなく、ピストン１４０に孔加工するだけで、容易に高圧側空間部Ｐｈの圧力を感圧部１４２の下面及び高圧感圧室１２９の弁体１４９からなる絞り部Ｂ"に導くことができる。また、弁体１４９及び弁座１２６の素材を、ステンレススチールにすることにより、弁体１４９及び弁座１２６の磨耗が軽減され、更に、弁体１４９及び弁座１２６はそれぞれピストン１４０及びシリンダ状筒体１２０に圧入して使用するために、ピストン１４０及びシリンダ状筒体１２０は安価な材料、例えば黄銅を使用でき経済的である。
【００５０】
【発明の効果】
上記構成により、本発明によれば、構造が簡単・コンパクトで耐久性があり、製造・加工が容易で廉価な差圧弁とすることができる。
【図面の簡単な説明】
【図１】本発明に係る実施例１の縦断面図。
【図２】図１のＤ部の詳細図。
【図３】本発明に係る実施例２の縦断面図。
【図４】図３のＤ'部の詳細図。
【図５】図１のＤ部に相当する部分の実施例３の詳細図。
【図６】本発明に係る実施例４の縦断面図。
【図７】図６のＤ"部の詳細図。
【符号の説明】
Ｐｈ・・高圧側空間部Ｐｌ・・低圧側空間部Ａ，Ａ'，Ａ"・・感圧部
Ｂ，Ｂ'，Ｂ"・・絞り部Ｃ，Ｃ'，Ｃ"・・調節部
１０・・外枠パイプ１１・・流体入口１２・・流体出口
１３・・カシメ部１４・・流路
２０，２０'・・筒状弁シート２０ａ・・径小部
２０ｂ，２０'ｂ・・径大部２０ｃ・・低圧空間形成部
２０ｄ・・弁部形成部２０ｅ，２０'ｅ・・バネ室形成部
２０ｆ，２０'ｆ・・弁室２１・・感圧部低圧空間
２２・・弁体支持孔２２ａ・・弁体支持部
２３・・弁孔２３ａ・・弁座部２４・・側孔
２５，２５'・・バネ室２５ａ・・支持筒２５ｂ・・支持筒側孔
２５ｃ・・支持筒周溝２６・・スカート部２７・・雌ネジ受部
２８・・Ｏリング２９・・カシメ受溝
３０・・弁体３１・・カシメ部３２・・低圧導入孔３３・・上横孔
３４・・下横孔３４ａ・・下横孔３５・・弁部３６・・径小部
３７・・径大部４０，４０'・・ピストン４０'ａ・・延伸軸部
４１・・Ｏリング４２・・高圧導入孔４３・・高圧側孔
５０・・調節ネジ５１・・通孔５２・・バネ受け
５２ａ・・バネ受け孔５３・バネ６０・・ストッパ
１１０・・外枠パイプ［実施例３］
１１１・・流体入口１１２・・流体出口１１３・・カシメ部
１２０・・シリンダ状筒体１２１・・カシメ用凹部
１２２・・バネケース装着部１２２ａ・・カシメ部
１２３・・リング溝１２３ａ・・Ｏリング
１２４・・低圧導入孔１２５・・弁座支持部１２６・・弁座
１２７・・弁座孔１２８・・低圧感圧室１２９・・高圧感圧室
１３０・・バネケース１３１・・径小部１３２・・ピストン支持部
１３３・・Ｏリング１３４・・バネ室１３５・・雌ネジ部
１４０・・ピストン１４１・・ピストン軸部１４２・・感圧部
１４３・・Ｏリング１４４・・弁体装着孔１４５・・受け凹部
１４６・・高圧導入（横）孔１４７・・高圧導入（縦）孔
１４８・・高圧導入（斜）孔
１４９・・弁体１４９ａ・・挿入部１４９ｂ・・径大部
１４９ｃ・・突部１５０・・調節ネジ１５１・・通孔
１５２・・バネ受け１５２ａ・・バネ受突部１５３・バネ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a differential pressure valve used in a refrigeration cycle of an air conditioner.
[0002]
[Prior art]
A differential pressure valve used in the same way as a refrigerant pressure regulating valve used in a refrigeration cycle of an air conditioner is a predetermined pressure (spring load) between both the upstream (high pressure) side and downstream (low pressure) side of the fluid. Flowing fluid only when there is a pressure difference greater than or equal to (corresponding pressure) (Patent Document 1), but the conventional direct-acting type requires pilot piping from the low-pressure side, etc. Not only is the structure complicated, but troubles such as refrigerant leakage at the welded portion of the pilot pipe may occur due to long-term operation.
[Patent Document 1]
Japanese Patent Laid-Open No. 09-113071 (see “Claims” and FIG. 1 in particular)
[0003]
[Problems to be solved by the invention]
An object of the present invention is to eliminate the above-mentioned problems of the prior art, and to provide a differential pressure valve that is simple and compact in structure and inexpensive at a differential pressure valve used in a refrigeration cycle of an air conditioner.
[0004]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention employs the following means. That is,
  The differential pressure valve according to claim 1, wherein a fluid inlet is formed at one end of the outer frame pipe,TheA fluid outlet is formed at the other end of the outer frame pipe,A cylindrical valve seat is inserted into the outer frame pipe and in the cylindrical valve seat,A pressure sensing unit that senses the differential pressure of the fluid, and the pressure difference detected by the pressure sensing unitFlow rateAn aperture for controllingTheAperture partbycontrolAmountAnd an adjustment unit to set to an arbitrary value.The high pressure side space is formed between the cylindrical valve seat and the fluid inlet, and the low pressure side space is formed between the cylindrical valve seat and the fluid outlet. A pressure-sensitive part low-pressure side space communicating with the low-pressure side space part, and a piston slidable between the pressure-sensitive part low-pressure side space and the high-pressure side space part, and the throttle part is the cylindrical shape A valve hole formed in the valve seat; and a valve body that penetrates the valve hole and is slidable in a fluid flow direction. The valve body has the piston fixed to one end portion and an intermediate portion. A valve portion is formed, the valve portion is disposed on the downstream side of the valve hole, and a conical portion contacting and separating from the valve seat portion of the valve hole; and a large-diameter portion provided on the downstream side thereof And a lower horizontal hole provided in the large-diameter portion and communicating the low-pressure side space and the pressure-sensitive portion low-pressure side space. In the tubular valve seat, a valve portion forming portion having a diameter larger than that of the valve hole is provided at a site downstream of the valve hole, and the large diameter portion of the valve body is disposed in the valve portion forming portion. The cross-sectional area of the flow path formed by the valve portion forming portion and the large diameter portion of the valve body is not less than the maximum opening area formed by the valve portion and the valve seat portion, and the valve hole Smaller than the cross-sectional area of the channelIt is characterized by that.
[0005]
  The differential pressure valve according to claim 2 is the differential pressure valve according to claim 1,The cylindrical valve seat portion is fixed by caulking in the outer frame pipe, and both end portions of the outer frame pipe are drawn into a joint shape.It is characterized by that.
[0006]
  The differential pressure valve according to claim 3 is the differential pressure valve according to claim 1 or 2,The outer diameter of the portion of the valve body that is slidably supported by the cylindrical valve seat and the inner diameter of the valve hole are made substantially the same.It is characterized by that.
  The differential pressure valve according to claim 4 is:A fluid inlet is formed at one end of the outer frame pipe, a fluid outlet is formed at the other end of the outer frame pipe, and a cylindrical case and a spring case connected and fixed upstream thereof are inserted into the outer frame, A high-pressure side space is formed between the spring case and the fluid inlet, a low-pressure side space is formed between the cylinder-shaped cylinder and the fluid outlet, and a differential pressure of fluid is generated in the cylinder-shaped cylinder. And a throttle part for controlling the flow rate of the fluid by the differential pressure sensed by the pressure sensitive part, and a control amount by the throttle part is set to an arbitrary value in the spring case. An adjustment part is provided, and the pressure sensitive part includes a piston slidably disposed in the cylindrical cylindrical body, a high pressure pressure sensitive chamber formed on the downstream side of the piston and communicating with the high pressure side space part, The low pressure side space formed on the upstream side of the piston A low-pressure pressure chamber communicating with the valve, the throttle portion being provided in a portion of the piston on the high-pressure pressure chamber side, the high-pressure pressure chamber provided in the cylindrical tubular body, and the A valve seat having a valve seat hole communicating with the low-pressure side spaceIt is characterized by that.
[0007]
  The differential pressure valve according to claim 5 is the differential pressure valve according to claim 4,A connecting body of the cylindrical cylindrical body and the spring case is caulked and fixed in the outer frame pipe, and both end portions of the outer frame pipe are formed into a joint shape.It is characterized by that.
  The differential pressure valve according to claim 6 is the differential pressure valve according to claim 4 or 5,The cylinder-shaped cylinder is provided with a low-pressure introduction hole that communicates the low-pressure chamber and the low-pressure side space.It is characterized by that.
[0008]
  The differential pressure valve according to claim 7,Any one of claims 4 to 6In the differential pressure valve described,The piston is provided with a high-pressure introduction hole that communicates the high-pressure-sensitive chamber and the high-pressure side space.It is characterized by that.
  The differential pressure valve according to claim 8,Any one of claims 4 to 7In the differential pressure valve described,The valve body and the valve seat are formed of stainless steel, the valve body is press-fitted into the piston, and the valve seat is press-fitted into the cylindrical cylindrical body.It is characterized by.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
[Example 1]
Example 1 will be described with reference to the drawings. 1 is a longitudinal sectional view thereof, and FIG. 2 is a detailed view of a portion D in FIG. In addition, although it demonstrates according to drawing below, the expression of upper, lower, left, and right is accompanying description of drawing, and does not necessarily correspond with actual positional relationship.
[0014]
First, the outer frame pipe 10 will be described.
As shown in FIG. 1, the differential pressure valve according to the first embodiment has a cylindrical outer frame pipe 10 as a whole, and a cylindrical valve seat that is shorter than the outer frame pipe 10 and is inserted and fixed in the outer frame pipe 10. 20 and a pressure-sensitive part A, a throttle part B, and an adjusting part C arranged in the tubular valve seat 20.
Further, a high-pressure side space portion Ph is formed near the fluid inlet 11 at one end of the outer frame pipe 10, and a low-pressure side space portion Pl is formed near the fluid outlet 12 at the other end of the outer frame pipe 10. The Reference numeral 13 denotes a caulking portion.
[0015]
Next, the cylindrical valve seat 20 will be described.
As shown in FIG. 2, the tubular valve seat 20 has a substantially cylindrical shape as a whole, and the outer diameter on the high-pressure side space portion Ph side is formed as a small-diameter portion 20 a by a predetermined length. The portion other than the small diameter portion 20a has an outer diameter slightly smaller than the inner diameter of the outer frame pipe 10. Further, a caulking receiving groove 29 is formed near the small diameter portion 20a in the outer diameter portion slightly smaller than the inner diameter of the outer frame pipe 10. And the flow path 14 is formed in the clearance gap between the said small diameter part 20a and the outer frame pipe 10, and the high voltage | pressure side space part Ph and the below-mentioned side hole 24 are connected.
[0016]
Further, inside the cylindrical valve seat 20, a large diameter portion 20b in which the piston 40 is housed and supported, and a pressure sensitive portion low pressure space 21 having a slightly smaller diameter than the large diameter portion 20b are formed. A valve body support part 22a, a valve body support hole 22 formed by the valve body support part 22a, a valve chamber 20f, a valve hole 23, and a valve part formation part 20d having a diameter larger than the valve hole 23, Further, the spring chamber forming portion 20e is continuously formed.
[0017]
A plurality of side holes 24 are formed in the lower part of the valve body support portion 22a, and the side holes 24 open to the valve chamber 20f. Therefore, the high-pressure side space Ph, the flow path 14, and the side holes 24, the valve chamber 20f, and the valve hole 23 are sequentially communicated. Further, the valve hole 23 communicates with the low pressure side space portion Pl below the valve portion 35 when the valve portion 35 is “open”.
The large-diameter portion 20b and the low-pressure space forming portion 20c form a pressure-sensitive portion A, the valve body support hole 22 supports the valve body 30, the valve hole 23 forms the throttle portion B, and the spring chamber forming portion 20e. Then, the adjustment part C is formed. Of course, one side hole 24 may be formed.
[0018]
Next, the valve body 30 will be described.
In particular, as shown in FIG. 2, a rod-shaped valve body 30 is disposed along the hole in the axial portion of the cylindrical valve seat 20. The valve body 30 penetrates from the large-diameter portion 20b of the cylindrical valve seat 20 through the low pressure space forming portion 20c, the valve body support portion 22a, the valve chamber 20f, the valve hole 23, and the valve portion forming portion 20d. It extends to 25. And in the large diameter part 20b part of the cylindrical valve seat 20, the piston 40 is attached to the valve body 30 integrally. In the mounting, a crimping portion 31 is formed on the valve body 30.
[0019]
Further, an upper lateral hole 33 communicating with the low pressure space forming portion 20c portion of the tubular valve seat 20 is formed in the diameter direction of the valve body 30, and is formed at the axial center portion of the valve body 30 in the length direction. It communicates with the introduction hole 32.
Further, the portion corresponding to the valve body support portion 22 a of the valve body 30 has a flat columnar shape, and the outer diameter of this portion is formed to be substantially the same as the inner diameter of the valve hole 23. This is because the thrust load caused by the fluid is not generated in the valve body 30. Further, a portion from the valve chamber 20 f of the valve body 30 to the valve hole 23 is formed as a small diameter portion 36. Further, a tapered valve part 35 having a large diameter on the lower side is formed below the small-diameter part 36, and is positioned on the valve part forming part 20 d of the tubular valve seat 20. Further, a lower horizontal hole 34 is formed in the spring chamber 25 portion of the valve body 30 in the diameter direction of the valve body 30 and opens to the spring chamber 25 and communicates with the low pressure introduction hole 32. Further, the lower end portion of the valve body 30 abuts on a spring receiver 52, and the spring receiver 52 is held by a spring 53.
Therefore, the low-pressure side space portion Pl always communicates with the pressure-sensitive portion low-pressure space 21 through the lower horizontal hole 34, the low-pressure introduction hole 32, and the upper horizontal hole 33.
[0020]
Next, the pressure sensitive part A will be described.
A piston 40 is disposed in the large diameter portion 20b of the cylindrical valve seat 20 so as to be slidable vertically with a predetermined width. The piston 40 is a disk having a predetermined thickness, and a sealing O-ring 41 is disposed in a ring groove formed on the outer periphery of the piston 40. Further, the upper end portion of the valve body 30 is fitted into the hole drilled in the center portion to form a caulking portion 31.
The upper surface of the piston 40 faces the high-pressure side space Ph, and the pressure-sensitive portion low-pressure space 21 is formed in the low-pressure space forming portion 20c between the lower surface of the piston 40 and the valve body support portion 22a. Yes. As described above, in the pressure-sensitive part low-pressure space 21, the fluid pressure in the low-pressure side space part Pl is guided through the upper horizontal hole 33, the low-pressure introduction hole 32, and the lower horizontal hole 34.
[0021]
And the piston 40 is
When the fluid pressure in the high-pressure side space portion Ph> the fluid pressure in the pressure-sensitive portion low-pressure space 21 + the spring load equivalent pressure of the spring 53,
When the fluid pressure of the high-pressure side space portion Ph <the fluid pressure of the pressure-sensitive portion low-pressure space 21 + the load equivalent pressure of the spring 53, the valve portion 35 opens.
Due to the vertical movement of the piston 40 due to the differential pressure, the valve body 30 integrated with the piston 40 also slides in the valve body support hole 22 of the cylindrical valve seat 20 while being supported by the valve body support portion 22a, and moves up and down. Will do.
[0022]
The throttle portion B includes a small-diameter portion 36 and a valve portion 35 of the valve body 30, and a valve hole 23, a valve seat portion 23a, and a valve portion forming portion 20d on the tubular valve seat 20 side. The opening area formed in the seat portion 23a increases or decreases in response to the differential pressure, and the flow rate is reduced and changed.
[0023]
Next, the adjustment unit C will be described.
The lower end portion of the valve body 30 is in contact with the spring receiving hole 52 a of the spring receiver 52, and the spring receiver 52 is elastically held on the throttle portion B side by the spring 53. Further, as shown in FIG. 1, the spring 53 is supported by an adjusting screw 50 that is screwed into the female screw receiving portion 27 of the skirt portion 26 that constitutes the lower portion of the cylindrical valve seat 20 and has a through hole 51. Therefore, the elastic force of the spring 53 against the spring receiver 52 can be adjusted by the rotation of the adjusting screw 50. This adjustment of the elastic force is an adjustment of the differential pressure amount.
[0024]
In configuring the differential pressure valve of the first embodiment, first, the O-ring 28 is attached to the valve body support portion 22a of the tubular valve seat 20, the valve body 30 is inserted into the tubular valve seat 20, and the O The piston 40 fitted with the ring 41 is fitted to the upper end portion of the tubular valve seat 20 together with the valve body 30 from above, the lower end portion of the valve body 30 is received by a jig, and the upper end portion of the valve body 30 is caulked. The piston 40 is fixed. The spring receiver 52 is brought into contact with the lower end portion of the valve body 30, the spring 53 is applied to the spring receiver 52, and the adjusting screw 50 is screwed into the female screw receiving portion 27.
[0025]
According to the above means, an extremely simple and compact differential pressure valve can be obtained.
[0026]
With this configuration, the valve body 30 moves up and down in response to the vertical movement of the piston 40 due to the differential pressure, the opening area formed by the valve portion 35 and the valve seat portion 23a is varied, and the flow rate is reduced and changed. become.
[0027]
Further, when a differential pressure equal to or greater than a predetermined amount of differential pressure is generated, the valve body 30 is moved downward in the throttle portion B due to the downward movement of the piston 40 in the pressure-sensitive portion A, and is throttled until a predetermined amount of differential pressure is reached. In part B, the flow rate is increased. On the other hand, when a pressure difference equal to or less than a predetermined amount of pressure difference occurs, the valve body 30 moves up in the throttle portion B due to the upward movement of the piston 40 in the pressure sensing portion A until the pressure difference reaches a predetermined amount. The flow rate is reduced or stopped at the throttle B.
In the first embodiment, the lower horizontal hole 34, the low pressure introduction hole 32, and the upper horizontal hole 33 are formed as the communication means between the low pressure side space portion Pl and the pressure sensitive portion low pressure space 21. In addition, without providing the low pressure introduction hole 32 and the upper horizontal hole 33, a communication path (not shown) that directly connects the low pressure side space portion Pl and the pressure sensitive portion low pressure space 21 may be provided in the cylindrical valve seat 20. Good.
[0028]
[Example 2]
Next, a second embodiment of the present invention will be described. 3 is a longitudinal sectional view thereof, and FIG. 4 is a detailed view of a portion D ′ in FIG. In the description of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description of the configuration is omitted.
In the first embodiment, a valve portion forming portion 20d having a diameter larger than that of the valve hole 23 is formed on the fluid downstream side of the valve hole 23. In the second embodiment, the valve located in the valve portion forming portion 20d is used. One or a plurality of lower horizontal holes 34a are provided in the large-diameter portion 37 of the portion 35 so that the valve portion forming portion 20d and the low-pressure introduction hole 32 communicate with each other.
Further, the flow passage area S formed by the valve portion forming portion 20d and the large diameter portion 37 of the valve body 30 (= the cross sectional area of the valve portion forming portion 20d−the cross sectional area of the large diameter portion 37) is set as the valve seat portion 23a. And the maximum opening area s formed by the valve part 35 and smaller than the flow path area m of the valve hole 23 (= transverse area of the valve hole 23−transverse area of the small diameter part 36).
Normally, as the flow rate increases, the pressure difference before and after the valve portion 35 increases, and the amount of pressure change with respect to the set differential pressure value tends to increase. However, in the differential pressure valve, the valve portion 35 against the change in flow rate. Since it is necessary to minimize the change in pressure difference between the front and the back, in the second embodiment, one or a plurality of small-diameter lower horizontal holes 34a are provided in the large-diameter portion 37 of the valve body 30, and the valve The flow passage area S formed by the portion forming portion 20d and the large diameter portion 37 of the valve body 30 is equal to or larger than the maximum opening area s formed by the valve seat portion 23a and smaller than the flow passage area m of the valve hole 23. As a result, the flow rate of the refrigerant is increased, and the pressure in the low-pressure space forming portion 20c is lower than the actual pressure due to Bernoulli's principle. As a result, the valve opening is increased and the pressure change is reduced even when a large flow rate flows out. It becomes possible to do.
[Example 3]
Next, Embodiment 3 of the present invention will be described. FIG. 5 is a detailed view of the third embodiment corresponding to the D part of FIG. In the description of the third embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description of the configuration is omitted. Also in the third embodiment, the shape of the outer frame pipe 10 is substantially the same as that of the first embodiment.
[0029]
Next, the cylindrical valve seat 20 ′ will be described.
The tubular valve seat 20 ′ has a cylindrical shape as a whole, and its outer shape has a uniform diameter over the entire length, but a caulking receiving groove 29 is formed at the center thereof. Further, inside the cylindrical valve seat 20 ′, a large-diameter portion 20′b for incorporating and supporting the piston 40 ′, a valve chamber 20′f having a slightly smaller diameter than the large-diameter portion 20′b, and a spring The chamber forming portion 20′e is continuously formed. The large-diameter portion 20′b forms a pressure-sensitive portion A ′, the valve chamber 20′f forms a throttle portion B ′, and the spring chamber forming portion 20′e forms an adjusting portion C ′.
[0030]
A support cylinder 25a is integrally provided at an intermediate position in the vertical direction of the cylindrical valve seat 20 ′. The support cylinder 25a supports an extension shaft portion 40'a on the piston 40 'side which will be described later. A support cylinder circumferential groove 25c is formed in the lower portion of the inner wall of the support cylinder 25a, and a support cylinder side hole 25b is formed between the support cylinder circumferential groove 25c and the outer surface of the support cylinder 25a. Yes.
[0031]
Next, the pressure sensitive part A ′ will be described.
A piston 40 'is disposed on the inner wall of the large diameter portion 20'b of the cylindrical valve seat 20' so as to be slidable vertically with a predetermined width. Piston 40 'consists of a disk of predetermined thickness, and O-ring 41 is arranged in the ring groove formed in the perimeter. In addition, an extension shaft portion 40 ′ a that hangs downward at a predetermined length is formed at the center portion, and a lower end thereof is held upward by a spring 53 via a spring receiver 52. Further, the upper limit position of the piston 40 ′ with respect to the cylindrical valve seat 20 ′ is limited by a stopper 60 fixed to the cylindrical valve seat 20 ′.
[0032]
The upper surface of the piston 40 'faces the high-pressure side space Ph, and the fluid pressure in the low-pressure side space Pl is guided to the lower surface of the piston 40' by the valve chamber 20'f.
And piston 40 'is the same as that of Example 1,
Fluid pressure of high-pressure side space portion Ph> Fluid pressure of low-pressure side space portion Pl + spring load equivalent pressure,
At the time of down,
When the fluid pressure in the high-pressure side space portion Ph <the fluid pressure in the low-pressure side space portion Pl + the spring load equivalent pressure, the pressure increases. The vertical movement of the piston 40 'moves up and down in a state where the extending shaft portion 40'a integrated with the piston 40' is also supported by the support cylinder 25a.
[0033]
The extending shaft portion 40'a and the support cylinder 25a constitute the throttle portion B '. A high-pressure introduction hole 42 is continuously formed at the center of the piston 40 ′ up to the center of the extending shaft 40 ′ a, and a high-pressure side hole 43 is formed laterally near the lower end of the high-pressure introduction hole 42. It is formed to be opened. Accordingly, the high-pressure side space Ph always communicates with the high-pressure side hole 43 through the high-pressure introduction hole 42.
The support cylinder 25a is formed with the support cylinder side hole 25b as described above. The refrigerant flows from the high pressure side space portion Ph to the low pressure side space portion Pl only when the high pressure side hole 43 overlaps the support cylinder circumferential groove 25c and a flow path is formed.
Note that the configuration of the adjusting portion C ′ including the spring 53 is substantially the same as that of the first embodiment.
[0034]
Since the means for using the differential pressure valve of the third embodiment is the same as that of the first embodiment, the description of the common parts will be omitted, and only the different parts will be described.
In the differential pressure valve according to the third embodiment, first, when the differential pressure is a predetermined amount or less, the piston 40 'does not move down, and the high-pressure side hole 43 does not overlap with the support cylinder circumferential groove 25c on the support cylinder 25a side. Therefore, the refrigerant does not flow out from the inner wall of the support cylinder 25a into the valve chamber 20′f.
[0035]
Further, when a predetermined amount of differential pressure is generated, the downward movement of the piston 40 ′ in the pressure sensitive part A causes the extension shaft part 40′a to move downward in the throttle part B ′, and the refrigerant is supplied to the valve chamber 20′f. Shed. Further, when the pressure difference becomes equal to or lower than the predetermined pressure difference, the valve body 30 is moved up at the throttle portion B ′ by the upward movement of the piston 40 ′ in the pressure sensitive portion A ′, and the throttle portion B until the pressure difference reaches a predetermined amount. Decrease / stop the flow with '.
Therefore, when the piston 40 ′ is in a predetermined position (position where the differential pressure is low), the piston 40 ′ does not flow into the valve chamber 20′f by the inner wall of the support cylinder 25a, but the piston 40 ′ is more than the predetermined position. , The high-pressure side hole 43 overlaps the support cylinder circumferential groove 25c, and the fluid flows out from the support cylinder side groove 25b. And the amount of outflow increases as the overlap increases.
[0036]
[Example 4]
Next, Example 4 will be described with reference to the drawings. 6 is a longitudinal sectional view thereof, and FIG. 7 is a detailed view of a portion D ″ in FIG.
First, the outer frame pipe 110 will be described.
As shown in FIG. 6, the differential pressure valve according to the third embodiment is made of an overall cylindrical metal, for example, copper outer frame pipe 110 and shorter than the outer frame pipe 110, and is inserted and fixed in the outer frame pipe 110. The cylinder-shaped cylinder 120 and the spring case 130, and the pressure-sensitive part A ″, the throttle part B ″, and the adjustment part C ″ arranged in the cylinder-shaped cylinder 120 and the spring case 130.
Further, a high pressure side space portion Ph is formed in the vicinity of the fluid inlet 111 at one end of the outer frame pipe 110, and a low pressure side space portion Pl is formed in the vicinity of the fluid outlet 112 at the other end of the outer frame pipe 110. The Further, a caulking portion 113 is formed at an intermediate portion of the outer frame pipe 110.
[0037]
Next, the cylindrical cylindrical body 120 will be described.
As shown in FIGS. 6 and 7, the cylindrical cylindrical body 120 disposed in the outer frame pipe 110 is formed in a substantially cylindrical shape as a whole, and the cylindrical cylindrical body 120 corresponding to the inner surface of the crimping portion 113. A caulking concave portion 121 is formed on the outer peripheral surface portion, and a spring case mounting portion 122 for mounting a spring case 130 described later is formed on the inner surface of the cylindrical cylindrical body 120. A crimped portion 122a is formed at the upper end of the spring case mounting portion 122 by fitting the small diameter portion 131 on the spring case 130 side, which will be described later, and then crimping it.
[0038]
The lower portion of the cylindrical cylindrical body 120 is formed with a predetermined thickness, and a plurality of low-pressure introduction holes 124 are formed in the upper and lower portions inside the predetermined thickness portion. A lower portion of the low pressure introduction hole 124 communicates with the low pressure side space portion Pl, and an upper portion thereof communicates with a low pressure pressure sensing chamber 128 formed in a cylindrical cylindrical body 120 described later.
A valve seat support portion 125 is formed at the lower end of the cylindrical cylindrical body 120, and a valve seat 126 made of, for example, stainless steel is attached to the central portion of the valve seat support portion 125 by press fitting. A valve seat hole 127 is formed in the valve seat 126.
[0039]
The spring case 130 has a small-diameter portion 131 at a lower portion thereof fitted into the spring case mounting portion 122 of the cylindrical cylindrical body 120. On the outer periphery of the small-diameter portion 131, a ring-shaped ring groove 123 that fits an O-ring 123a disposed between the small-diameter portion 131 and the cylindrical tubular body 120 is formed. Further, an O-ring 133 is interposed inside the small-diameter portion 131, and serves as a piston support portion 132 that supports a piston 140 described later.
The upper part of the spring case 130 is fitted to the inner peripheral surface of the outer frame pipe 110, and a spring chamber 134 is formed on the inner surface thereof. A female screw part 135 is formed on the inner periphery of the upper end of the spring case 130, and an adjustment screw 150 is screwed into the female screw part 135.
The adjustment screw 150 has a through hole 151 formed at the center thereof, and communicates the upper high-pressure side space Ph with the spring chamber 134.
[0040]
Next, the pressure sensitive part A ″ will be described. The pressure sensitive part A ″ is formed in the lower part of the piston 140. The piston 140 as a whole is formed as a cylindrical body having a different diameter that is long in the vertical direction. The upper portion is a small-diameter piston shaft portion 141 and the lower portion is a large-diameter pressure-sensitive portion 142. The piston shaft portion 141 is supported by the piston support portion 132 so as to be slidable in the vertical direction, and the pressure sensitive portion 142 is supported by the inner peripheral surface of the lower portion of the cylindrical cylindrical body 120 so as to be slidable in the vertical direction. ing. Also. An O-ring 143 is interposed between the outer periphery of the pressure sensitive part 142 and the inner peripheral surface of the cylindrical cylindrical body 120.
[0041]
Further, a high-pressure introduction vertical hole 147 is formed in the axial direction of the piston 140 in the length direction (axial direction). The high-pressure introduction horizontal hole 146 communicates with the high-pressure introduction vertical hole 147 at the upper portion thereof. The end of the high-pressure introduction lateral hole 146 is open to the spring chamber 134. In addition, a high-pressure introduction oblique hole 148 is formed in a lower portion of the high-pressure introduction vertical hole 147 in communication with the high-pressure introduction vertical hole 147, and an end thereof opens to a space below the pressure-sensitive portion 142.
[0042]
Therefore, the space portion on the upper surface of the pressure-sensitive portion 142 communicates with the low-pressure side space portion Pl through the low-pressure introduction hole 124 to form the low-pressure pressure chamber 128. The hole 146, the high-pressure introduction vertical hole 147, and the high-pressure introduction oblique hole 148 communicate with the high-pressure side space Ph to form a high-pressure-sensitive chamber 129.
Further, a receiving recess 145 having a spherical inner surface is formed at the upper end of the piston 140, and a spring receiving projection 152a abuts on the bottom of the receiving recess 145 by the elastic force of the spring 153 to form a universal joint. ing. Due to this contact state, even if an eccentric load is applied to the piston 140 due to the elastic force of the spring 153 or the high-pressure refrigerant, the piston 140 smoothly acts as a vertical pressure.
[0043]
The throttle portion B ″ is configured by a stainless steel valve body 149 mounted in a valve body mounting hole 144 formed continuously from the high pressure introduction vertical hole 147 below the pressure sensing section 142 and the valve seat 126. That is, the valve body 149 includes a columnar insertion portion 149a into the valve body mounting hole 144, a disk-shaped large-diameter portion 149b, and an inverted conical protrusion 149c at the lower end, and the protrusion 149c. The opening area formed by the valve seat 126 increases and decreases as the piston 140 moves up and down in response to the differential pressure, and the flow rate is reduced and changed.
[0044]
Piston 140 is
When the fluid pressure in the high pressure sensing chamber 129> the fluid pressure in the low pressure sensing chamber 128 + the spring load equivalent pressure of the spring 153, the valve body 149 opens.
When the fluid pressure in the high pressure pressure sensing chamber 129 <the fluid pressure in the low pressure sensing chamber 128 + the spring load equivalent pressure of the spring 153, the valve body 149 is closed.
[0045]
Next, the adjustment unit C ″ will be described.
A spring 153 is contracted between the lower surface of the adjustment screw 150 (on the spring chamber 134 side) and a spring receiver 152 disposed at the lower portion of the spring chamber 134, and the spring 153 presses the spring receiver 152 downward and pressurizes it. Yes. A spring receiving surface is formed on the upper surface of the spring receiver 152, and a spring receiving protrusion 152a having a spherical lower end is integrally formed on the lower surface. This adjustment of the elastic force is an adjustment of the differential pressure amount.
[0046]
In assembling the differential pressure valve of the fourth embodiment, first, the valve seat 126 is mounted on the valve seat support 125 of the cylindrical cylindrical body 120, the valve body 149 is mounted on the valve body mounting hole 144 of the piston 140, and then the cylinder The piston 140 is fitted to the cylindrical body 120. Next, the spring receiver 152 and the spring 153 are housed in this order in the spring case 130, and the adjustment screw 150 is screwed into the female screw portion 135.
The spring case 130 is attached to and fixed to the cylindrical cylindrical body 120 while the spring receiving protrusion 152a is loosely fitted in the receiving recess 145. In fixing, after the small diameter portion 131 is fitted to the spring case mounting portion 122 as described above, the crimping portion 122a is crimped to ensure integration.
Then, the cylindrical cylindrical body 120 and the spring case 130 are fitted into the outer frame pipe 110, and the caulking part 113 and the caulking concave part 121 are aligned, and then caulking. According to the above means, an extremely simple and compact differential pressure valve can be obtained.
[0047]
With this configuration, the valve body 149 moves up and down according to the vertical movement of the piston 140 due to the differential pressure, the opening area formed by the valve body 149 and the valve seat 126 is changed, and the flow rate is reduced and changed. become.
Further, when a differential pressure equal to or greater than a predetermined amount of differential pressure is generated, the valve body 149 is moved up at the throttle portion B ″ by the upward movement of the piston 140 in the pressure-sensitive portion A ″, resulting in a predetermined amount of differential pressure. The flow rate is increased at the throttle portion B ". Conversely, when the differential pressure is not more than a predetermined amount, the valve element 149 moves downward at the throttle portion B" due to the downward movement of the piston 140 in the pressure sensitive portion A ". Then, the flow rate is reduced or stopped at the throttle B "until a predetermined pressure difference is reached.
[0048]
In particular, in the fourth embodiment, by providing the low pressure pressure sensing chamber 128 on the high pressure introduction side, the valve body 149 can be installed in the positive valve direction (high pressure sensing chamber 129 side), so that a flow control of a minute flow rate is possible. Become.
Further, after attaching the piston 140 and the spring case 130 to the cylindrical cylindrical body 120, the upper end portion 122a of the cylindrical cylindrical body 120 is crimped to form a crimped portion, and the spring case 130 and the cylindrical cylindrical body 120 are integrated, thereby The low-pressure pressure chamber 128 and the high-pressure chamber 129 can be formed above and below, and the cylindrical cylindrical body 120 and the spring case 130 can be integrated to facilitate assembly with a jig. Since the assembly to the outer frame pipe 110 in the final assembly process is facilitated, the number of steps can be reduced.
[0049]
Furthermore, according to the fourth embodiment, the pressure in the low-pressure side space portion Pl can be easily applied to the low-pressure pressure-sensitive chamber 128 above the pressure-sensitive portion of the piston without increasing the number of parts and by simply drilling holes in the cylindrical cylindrical body 120. The pressure of the high pressure side space portion Ph can be easily reduced from the lower surface of the pressure sensing portion 142 and the valve body 149 of the high pressure pressure sensing chamber 129 by simply drilling the piston 140 without increasing the number of parts. The valve body 149 and the valve seat 126 are made of stainless steel, so that wear of the valve body 149 and the valve seat 126 is reduced. Further, the valve body 149 and Since the valve seat 126 is used by being press-fitted into the piston 140 and the cylinder-shaped cylinder 120, respectively, the piston 140 and the cylinder-shaped cylinder 120 can use an inexpensive material, for example, brass, and are economical.
[0050]
【The invention's effect】
With the above configuration, according to the present invention, a differential pressure valve that is simple, compact, durable, easy to manufacture and process, and inexpensive.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a first embodiment according to the present invention.
FIG. 2 is a detailed view of a portion D in FIG.
FIG. 3 is a longitudinal sectional view of a second embodiment according to the present invention.
4 is a detailed view of a portion D ′ in FIG. 3;
FIG. 5 is a detailed view of a third embodiment of the portion corresponding to the D portion in FIG.
FIG. 6 is a longitudinal sectional view of a fourth embodiment according to the present invention.
7 is a detailed view of a portion D ″ in FIG. 6;
[Explanation of symbols]
Ph ·· High pressure side space portion Pl · · Low pressure side space portion A, A ', A "·· Pressure sensitive portion
B, B ', B "··· Restricting part C, C', C" ··· Adjusting part
10 .... Outer frame pipe 11 .... Fluid inlet 12 .... Fluid outlet
13 .... Caulking part 14 .... Flow path
20, 20 '· · · cylindrical valve seat 20a · · small diameter part
20b, 20'b ... Large diameter part 20c ... Low pressure space forming part
20d ... Valve part forming part 20e, 20'e ... Spring chamber forming part
20f, 20'f ・・ Valve 21 ・・ Low pressure space
22.Valve support hole 22a ... Valve support part
23 .... Valve hole 23a ... Valve seat 24 .... Side hole
25, 25 '... Spring chamber 25a ... Support cylinder 25b ... Support cylinder side hole
25c ··· Supporting cylinder circumferential groove 26 · · Skirt portion 27 · · Female screw receiving portion
28 ・・ O-ring 29 ・・ Caulking groove
30 ... Valve 31 ... Caulking part 32 ... Low pressure introduction hole 33 ... Upper side hole
34..Lower horizontal hole 34a..Lower horizontal hole 35..Valve part 36..Small diameter part
37 ·· Large diameter portion 40, 40 '· · Piston 40'a · · Extension shaft
41 ... O-ring 42 ... High-pressure introduction hole 43 ... High-pressure side hole
50 ... Adjusting screw 51 ... Through hole 52 ... Spring holder
52a ・・ Spring receiving hole 53 ・ Spring 60 ・・ Stopper
110 .. Outer frame pipe [Example 3]
111 .. Fluid inlet 112 .. Fluid outlet 113 .. Caulking section
120 .. Cylinder-shaped cylinder 121 .. Recess for caulking
122 ... Spring case mounting part 122a ... Caulking part
123 ・・ Ring groove 123a ・・ O-ring
124 ·· Low pressure introduction hole 125 · · Valve seat support 126 · · Valve seat
127 ... Valve seat hole 128 ... Low pressure pressure chamber 129 ... High pressure pressure chamber
130 ... Spring case 131 ... Small diameter part 132 ... Piston support
133 .. O-ring 134 .. Spring chamber 135 .. Female thread
140 .. Piston 141 .. Piston shaft 142.. Pressure sensitive part
143 ... O-ring 144 ... Valve body mounting hole 145 ... Receiving recess
146 ・・ High-pressure introduction (horizontal) hole 147 ・・ High-pressure introduction (vertical) hole
148 ・・ High-pressure introduction (oblique) hole
149 ... Valve 149a ... Insertion part 149b ... Diameter part
149c ... Projection 150 ... Adjusting screw 151 ... Through hole
152 .. Spring receiver 152a .. Spring receiving protrusion 153 Spring

Claims

Fluid inlet is formed at one end of the outer frame pipe, the fluid outlet is formed in the other end of the outer frame pipe, the cylindrical valve in the sheet with the cylindrical valve seat to the outer frame pipe is inserted, a fluid It provided a pressure-sensing section for sensing the differential pressure, and adjusting unit for setting a throttle portion for controlling the flow rate of the fluid due to the pressure difference sensed by the sensitive pressure portion, a control amount by the said diaphragm portion to an arbitrary value A high-pressure side space is formed between the cylindrical valve seat and the fluid inlet, and a low-pressure side space is formed between the cylindrical valve seat and the fluid outlet. A pressure-sensitive part low-pressure side space communicating with the low-pressure side space part, and a piston slidable between the pressure-sensitive part low-pressure side space and the high-pressure side space part. Valve hole formed in the valve seat, and a valve body penetrating the valve hole and slidable in the fluid flow direction The valve body has the piston fixed to one end portion and a valve portion formed in the intermediate portion, and the valve portion is disposed downstream of the valve hole and is a valve seat portion of the valve hole. A conical portion that is in contact with and away from, a large-diameter portion provided on the downstream side thereof, and a lower horizontal hole that is provided in the large-diameter portion and communicates the low-pressure side space portion and the pressure-sensitive portion low-pressure side space. A valve portion forming portion having a diameter larger than that of the valve hole is provided in a portion of the tubular valve seat downstream of the valve hole, and the large diameter portion of the valve body is disposed in the valve portion forming portion. The cross-sectional area of the flow path formed by the valve portion forming portion and the large diameter portion of the valve body is greater than or equal to the maximum opening area formed by the valve portion and the valve seat portion, and A differential pressure valve characterized by being smaller than the cross-sectional area of the flow path of the valve hole .

The differential pressure valve according to claim 1, wherein the cylindrical valve seat portion is caulked and fixed in the outer frame pipe, and both end portions of the outer frame pipe are drawn into a joint shape .

The differential pressure valve according to claim 1 or 2 , wherein an outer diameter of a portion of the valve body that is slidably supported by the cylindrical valve seat and an inner diameter of the valve hole are substantially the same .

A fluid inlet is formed at one end of the outer frame pipe, a fluid outlet is formed at the other end of the outer frame pipe, and a cylindrical case and a spring case connected and fixed upstream thereof are inserted into the outer frame, A high-pressure side space is formed between the spring case and the fluid inlet, a low-pressure side space is formed between the cylinder-shaped cylinder and the fluid outlet, and a differential pressure of fluid is generated in the cylinder-shaped cylinder. And a throttle part for controlling the flow rate of the fluid by the differential pressure sensed by the pressure sensitive part, and a control amount by the throttle part is set to an arbitrary value in the spring case. An adjustment part is provided, and the pressure sensitive part includes a piston slidably disposed in the cylindrical cylindrical body, a high pressure pressure sensitive chamber formed on the downstream side of the piston and communicating with the high pressure side space part, The low pressure side space formed on the upstream side of the piston A low-pressure pressure chamber communicating with the valve, the throttle portion being provided in a portion of the piston on the high-pressure pressure chamber side, the high-pressure pressure chamber provided in the cylindrical tubular body, and the And a valve seat having a valve seat hole communicating with the low-pressure side space .

The connecting body of the cylindrical cylindrical body and the spring case is caulked and fixed in the outer frame pipe, and both ends of the outer frame pipe are formed into a joint shape by drawing . Differential pressure valve.

6. The differential pressure valve according to claim 4 or 5 , wherein a low-pressure introduction hole for communicating the low-pressure chamber and the low-pressure space is provided in the cylindrical cylindrical body .

The differential pressure valve according to any one of claims 4 to 6, wherein the piston is provided with a high-pressure introduction hole that communicates the high-pressure chamber and the high-pressure space .

8. The valve body and the valve seat are made of stainless steel, the valve body is press-fitted into the piston, and the valve seat is press-fitted into the cylindrical cylindrical body . The differential pressure valve according to any one of the above.