JP3659394B2

JP3659394B2 - Liquid tightness measuring device

Info

Publication number: JP3659394B2
Application number: JP10149999A
Authority: JP
Inventors: 基正飯塚; 賢治金原; 善博中瀬; 明岡田; 英雄木内
Original assignee: Denso Corp; Nippon Soken Inc
Current assignee: Denso Corp; Soken Inc
Priority date: 1998-06-30
Filing date: 1999-04-08
Publication date: 2005-06-15
Anticipated expiration: 2019-04-08
Also published as: JP2000081361A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば燃料噴射弁や流量制御弁等の閉弁時に漏洩する液の量を計測する液密計測装置に関する。
【０００２】
【従来の技術】
従来より、内燃機関の燃料噴射弁や、流量制御弁等の検査等において、閉弁時に弁部から漏洩する液量が計測される。例えば燃料噴射弁の場合、漏洩する液量が多いと、空燃比制御の正確さが損なわれて排気ガス量の増加等を招くため、液密の計測は重要である。液密計測装置は、試験対象物である燃料噴射弁や流量制御弁等の出口を採取口と密着せしめるとともに、試験対象物に試験液を充填し、充填された試験液を加圧し、加圧状態で弁部から漏洩した試験液を採取しその液量を計測するもので、採取した試験液は、採取通路を介して透明なガラス製の細い丸管に導入し、その液面変位から液量が計測される。漏洩した液量は、液面の変位量と細管の断面積とに基づいて求めることができる（特開平４−１０５０１９号公報、特開平４−２５５５６８号公報、特開平５−６６１７３号公報、特開平９−８８７６９号公報等）。
【０００３】
上記特開平４−１０５０１９号公報、特開平４−２５５５６８号公報、特開平９−８８７６９号公報には、細管を横切るように光を透過せしめ透過光に基づいて液面を検出する光方式の液面検出手段を設けることで、漏洩量の計測の自動化を図るとともに、作業者による計測ばらつきを防止している。また、上記特開平９−８８７６９号公報記載の装置では、ポンプにより試験液を試験対象物に送出し、充填および加圧することで自動化を促進している。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記各公報記載の発明は液密計測の自動化を主眼とするものであって、漏洩の少ない高性能な燃料噴射弁や流量制御弁について、漏洩した液量を高精度に知ることができない。また、漏洩した液量の計測精度が十分でないと、燃料噴射弁の場合、排気ガス規制の強化に対して十分に対応できないおそれがある。
【０００５】
本発明は上記実情に鑑みなされたもので、漏洩した液量の計測精度の高い液密計測装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本願の発明は、充填試験液加圧手段により試験対象物に充填された試験液を加圧した状態で、試験対象物の液密部から漏洩する試験液を採取通路の一端に形成した採取口から採取し、採取通路の他端と接続された透明な細管に導入し、液面検出手段が、発光部から細管を横切るように光を照射してその光を受光部で検出し、検出光に基づいて細管内の試験液の液面を検出し、液面の変化から上記液密部から漏洩した試験液の量を計測する液密計測装置に関するもので、請求項１記載の発明では、試験液の温度を制御する温度調整手段を設ける。温度調整手段には、試験対象物に供給する試験液との熱交換および上記細管に導入される試験液との熱交換を行う熱交換手段を具備せしめる。熱交換手段はこれらの試験液に共通の熱交換手段とする。
本発明では、上記構成をとることにより、試験対象物に供給される試験液と、細管に導入される試験液とで、共通の熱交換手段により熱交換が行われて温度が調整されるから、試験液間の温度差が低減し、計測精度を高めることができる。
【００１９】
また請求項１記載の発明では、上記熱交換手段は、上記細管の管壁内部に縦孔を形成し、縦孔に細管壁と熱交換する熱媒体を流通せしめる構成とする。
【００２０】
細管の管壁を温調することで装置設置雰囲気が温度変動しても細管の熱膨張および熱収縮を防止するようにしたので、計測精度をさらに高めることができる。
【００２３】
請求項２記載の発明では、試験液の温度を制御する温度調整手段を設けて、試験対象物に供給する試験液との熱交換および上記細管に導入される試験液との熱交換を行う熱交換手段を具備せしめるとともに、上記採取通路を、最低位置となる屈曲部から上方へと延び上記一端および上記他端に到る形状とする。
【００２４】
採取通路に水平方向に形成された部分や山形に曲がる部分を設けないことで、採取通路内に気泡が滞留しない。したがって、気泡の存在による計測誤差を防止することができる。
【００２５】
請求項３記載の発明では、試験液の温度を制御する温度調整手段を設けて、試験対象物に供給する試験液との熱交換および上記細管に導入される試験液との熱交換を行う熱交換手段を具備せしめるとともに、非計測時に採取通路および細管内の試験液を加圧する気泡検出用加圧手段を具備せしめ、加圧時の試験液液面の変位量に基づいて試験液中の気泡の混入量を検出する。
【００２６】
採取通路および細管内の気泡は、試験液の加圧により圧縮し、その細管内の試験液液面が下降する。この下降量は気泡の量に比例するから、気泡量を定量的に知ることができ、高い計測精度を得ることができる。
【００２７】
請求項４記載の発明では、試験液の温度を制御する温度調整手段を設けて、試験対象物に供給する試験液との熱交換および上記細管に導入される試験液との熱交換を行う熱交換手段を具備せしめるとともに、細管を上記採取通路の上記他端から立設せしめ、かつ、細管の下端部に通じ、漏洩試験液の計測後に細管内の試験液を細管外へ排出する排出通路を設け、排出通路の排出口を漏洩試験液の計測の基準となる所定の初期液面の高さに開口せしめる。
【００２８】
漏洩試験液の計測後には、次の計測に備え、試験液を排出して細管内の液面を所定の初期液面に戻す必要がある。しかし、初期液面になるように試験液の量を調整するのは手動であれ、液面検出による調量制御であれ容易ではなく、初期液面のばらつきにより計測誤差が生じる。本発明では、計測後、細管内の試験液は、その自重により排出口から排出され、細管内の液面が排出口の高さで釣り合おうとする。排出口を初期液面の高さに開口せしめることで、細管内の液面が初期液面に高精度で設定される。しかも、そのための制御系が不要なので装置の構成は簡単である。
【００２９】
請求項５記載の発明では、請求項４記載の発明の構成において、上記採取通路の採取口を上記細管の初期液面よりも下方に設け、上記試験対象物の液密部が上記採取口から取り外されたときに細管から逆流する試験液が流入し試験液が貯留する液溜まりを設け、液溜まりを、上記初期液面の高さにおいてオーバフローする構成とし、上記排出通路を採取通路と液溜まりとで構成する。
【００３０】
計測後には採取通路が排出通路となるので、さらに装置の構成を簡単にすることができる。
【００３１】
【発明の実施の形態】
（第１実施形態）
図１に、本発明の第１実施形態になる液密計測装置の構成を示す。液密計測装置は、基台９上に、試験対象物１を保持する保持装置８、試験対象物１から漏洩した試験液を導入する細管３および細管３の液面変位に基づいて試験対象物１から漏洩した液量を計測する液面検出手段たるレーザ式変位センサ４を有している。試験対象物１は、本実施形態では内燃機関の燃料噴射弁である。
【００３２】
試験対象物１は、保持装置８の、断面コ字形の固定治具８２に、先端部１１を下方に向けて固定され、先端部１１は固定治具８２の底板から下方に突出している。試験対象物１には、燃料タンク７１から充填用配管７２を介して試験液たる燃料が供給され、試験対象物１内に燃料が供給される。試験対象物１は、これを駆動する図略の制御装置と結線され、開弁と閉弁とを切り替えられるようになっている。
【００３３】
保持装置８は、基台９と一体の軌道部８１が、試験対象物１が固定される固定治具８２を上下動自在に保持している。軌道部８１と固定治具８２とでシリンダ８３が形成され、固定治具８２の側面から突出するスプール８２１がシリンダ８３内を変位するようになっている。シリンダ８３にはスプール８２１の上側の空間および下側の空間にレギュレータ６８および三方弁６９を介してガスボンベ６０から空気や窒素等の圧縮性ガスが導入されるようになっている。三方弁６９の切り替えによりスプール８２１を上側からもしくは下側からガス圧力により押圧することで、スプール８２１を上端位置まで押し上げもしくは下端位置まで押し下げる。これにより、試験対象物１を後述する台部９２上へのランドと、台部９２からのリフトとを切り替え可能としてある。
【００３４】
一方、基台９の上部には液溜まりたる廃液皿９１が設けてあり、その底部には、試験対象物１の先端部１１に対向して台部９２が設けてある。
【００３５】
また、基台９内部にはコ字状の採取通路２が形成してあり、その一端は台部９２の頂面に開口して採取口２０１としてあり、他端２０２は細管３を取り付けるための凹部９５の底面に開口している。
【００３６】
採取口２０１は、試験対象物１のランド時には、試験対象物１の先端面が台部９２の頂面に密着して閉鎖されるようになっており、試験対象物１の液密部である弁部から漏洩する燃料を、噴射口１１１から採取するようになっている。なお、採取口２０１の周縁部にはシール用のＯリングが設けられて試験対象物１と台部９２間の液密を保持する。
【００３７】
また、廃液皿９１内にはシャッタ９４が設けてあり、試験対象物１のリフト時に、試験対象物１と台部９２間に挿入される。シャッタ９４は採取口２０１よりも大径の平板であり、水平方向に進退自在にスライドするように構成され、左方に進出すると採取口２０１をカバーし、右方に退避すると試験対象物１のランドが可能になる。
【００３８】
細管３は、基台９上に正立して配設される。細管３の下端部が基台９の凹部９５に嵌入し、下端において細管３と採取通路２とが連通している。細管３および採取通路２には、後述するように計測前に所定量の燃料が供給され、細管３内の燃料の液面が初期液面に設定される。そして液面は、計測時に試験対象物１の噴射口１１１からの燃料の液量に応じて初期液面から上昇する。この上昇量から漏洩した燃料の液量が知られる。
【００３９】
図２は、細管３の製造各工程における細管の断面で、細管３は従来のように引き出し丸形管ではなく、四角形管であり、複数の縦割りしたガラス製の管壁部材から製作される。（１），（２），（３）に管壁部材の形状の異なる３つの例を示している。（１）では平板状の管壁部材３１と断面コ字状の管壁部材３２とから製作され、（２）では断面Ｌ字状の管壁部材３３，３４とから製作され、（３）では広幅で平板状の管壁部材３５，３６と狭幅で平板状の管壁部材３７，３８とから製作され、いずれも、図示のように、管壁３０１，３０２，３０３，３０４は、曲面のない平板状で、対向する管壁３０１と管壁３０２、管壁３０３と管壁３０４が平行に配置するように組み合わされる。
【００４０】
また、各管壁部材３１〜３８は、図のように所定の形状に成形された後、外側表面のうち、レーザ光が入射する面３ａおよび出射する面３ｂ、および内側表面３ｃ，３ｄ，３ｅ，３ｆを研磨による平坦化処理で高精度な平面出しを行う。
【００４１】
研磨の後、管壁部材３１〜３８は高温下で融着される。
【００４２】
細管３は、さらに内側の表面３ｃ〜３ｆに撥水コーティングが形成され、完成する。
【００４３】
採取通路２は、採取口２０１から真っ直ぐに下降し、斜め下方に向きを変えて細管３の直下の屈曲部２０３まで延び、屈曲部２０３から他端２０２まで真っ直ぐ上昇している。
【００４４】
採取通路２の屈曲部２０３から斜め下方に分岐する別の接続通路７５が形成してある。接続通路７５は燃料配管７４と接続され、燃料タンク７１から燃料を燃料配管７４を介して採取通路２および細管３内に供給するようになっている。
【００４５】
接続通路７５の最も採取通路２側には遮断弁７６が設けてあり、採取通路２と通路７５間の連通と遮断とを切り替えるようになっている。遮断弁７６は装置の立ち上げ時に開き、採取通路２および細管３内に初期液量が供給され、計測時には閉じられる。
【００４６】
レーザ式変位センサ４は発光部４１と受光部４２とを有している。発光部４１は、上下方向の所定範囲からレーザ光線を帯状に照射する構成のもので、細管３の各高さにおいて、レーザ光線が水平方向に細管３を横切るように照射される。受光部４２は上下方向に配置されたラインＣＣＤ等で構成され、細管３の各高さにおいて細管３を横切り透過する光線を検出するようになっている。受光部４２における検出光強度の不連続部から、細管３内の燃料の液面を検出する。また、上記レーザ光線が細管３の入射側管壁３０１に対して垂直方向に照射するように発光部４１および細管３を配置し、レーザ光線の進行経路を入射側管壁３０１および出射側管壁３０２に対して直交するようにとる。これにより、レーザ光線の偏光、乱反射を防止し、燃料液面の検出精度を高めている。
【００４７】
燃料タンク７１には、ガスボンベ６０から上記圧縮ガスがガス配管６１から、さらにレギュレータ６２および三方弁６４を介して供給されるようになっている。また燃料タンク７１内のガスは、三方弁６４の切り替えにより大気開放されたガス配管６３を介して排出され大気圧に減圧されるようになっている。ガスボンベ６０とガス配管６１とレギュレータ６２と三方弁６４とで充填試験液加圧手段６ａを構成する。
【００４８】
また、ガスボンベ６０の圧縮性ガスはガス配管６１から、さらにレギュレータ６５および三方弁６７を介し、細管３の上端部を受ける保持部材９６に形成した直線通路９６１から細管３の上端より細管３内に供給されるようになっている。また細管３内は、三方弁６７の切り替えによりガス配管６６を介して大気開放されるようになっている。ガスボンベ６０とガス配管６１とレギュレータ６５と三方弁６７とで気泡検出用加圧手段６ｂを構成する。
【００４９】
また、本液密計測装置には、燃料タンク７１、供給配管７２、および採取通路２内の燃料を温度調整する温度調整手段たる温度制御部５を備えている。温度制御部５は、熱媒体が循環する熱媒体流路たる温調配管５１およびタンク５２と、熱媒体を加熱冷却する加熱冷却手段たる加熱冷却部５４とを有している。
【００５０】
タンク５２内の熱媒体はポンプ５３により温調配管５１の上流部５１１へと送出され、下流部５１３より再びタンク５２に戻る循環路を形成している。温調配管５１は、上流部５１１が燃料タンク７１に貯留した燃料中に浸漬し、中流部５１２が燃料配管７２の外周に配設され、下流部５１３が、採取通路２の形成された基台９内部に形成されており、温調配管５１を循環する熱媒体が、燃料タンク２、燃料配管７２、採取通路２内の各燃料と共通に熱交換する。
【００５１】
加熱冷却部５４は、電気ヒータ５４１およびウォータクーラ５４２がタンク５２内の熱媒体を加熱または冷却し熱媒体を温度調整する。
【００５２】
本液密計測装置の作動について説明する。図３は計測手順を示すフローチャートであり、図４、図５、図６、図７、図８、図９は各計測手順における液密計測装置の作動状態を示している。ステップＳ１にて作動を開始する。図４は作動開始時における状態を示している。三方弁６４，６７は細管３および燃料タンク７１が排出配管６３，６６と連通する大気開放側に設定されている。また、三方弁６９はスプール８２１を上方に押し上げ試験対象物１がリフトするリフト側に設定されている。シャッタ９４は右方に退避している。また遮断弁７３，７６は「閉」である。
【００５３】
図５は続くステップＳ２の燃料充填時の状態を示すもので、図４の状態から三方弁６４を、ガスボンベ６０からのガス圧力が燃料タンク７１内に供給される加圧側に切り替え、燃料タンク７１内の燃料を加圧する。シャッター９４を左方へスライドさせ試験対象物１と採取口２０１間に挿入する。次いで遮断弁７６を開く。燃料タンク７１内の燃料が、燃料タンク７１内に供給されたガス圧力により、図中、点線矢印に示すように採取通路２内へ供給される。燃料は採取口２０１から噴出してシャッタ９４の下面に沿って流れて廃液皿９１に溜まり、その液面は上昇する。そして、液面が廃液皿９１の排出口９３の高さに達すると、余剰燃料はオーバーフローして排出口９３から排出され、液面上昇が停止する。このとき、細管３内の燃料の液面Ｌ１も排出口９３の高さで停止する。このように、燃料の計量手段を用いることなく、採取通路２および細管３内に所定量の初期燃料を充填することができる。
【００５４】
さて、このように、採取通路２には初期燃料が充填されるが、採取通路２を、上記のごとく屈曲部２０３から上方へと延び一端２０１および他端２０２に到る形状としたことで、採取通路２内に気泡が滞留しないようにしている。気泡が滞留すると、その分、実際に漏洩した燃料よりも細管３における液面の上昇量が多くなり、計測誤差の原因となるが、上記のように気泡の滞留を防止することで、漏洩した燃料の計測精度を高めることができる。
【００５５】
次いでステップＳ３に進む。図６は、ステップＳ３の試験対象物駆動時の状態を示すもので、図５の状態から、先ず、遮断弁７６を閉じ採取通路２および細管３側と通路７５側とを遮断する。次いで、遮断弁７３を開いて燃料タンク７１と試験対象物１間を連通せしめるとともに、試験対象物１を駆動して試験対象物１内に燃料を充填する。試験対象物１の開弁で、燃料がシャッタ９４の上面に落下して廃液皿９１へ溜まるが、排出口９３を越える液位となる余剰燃料は排出口９３から排出される。
【００５６】
また、燃料タンク２、燃料配管７２、採取通路２内の燃料は、温度調整部５の作動により温度調整され、一定に保たれる。ここで、燃料と熱交換する熱媒体が試験対象物１に供給される燃料および細管３に導入される燃料に共通とすることで、両燃料間の温度差が低減し、燃料体積の膨張、収縮が抑えられて漏洩燃料の計測精度を高めることができる。しかも、上記各燃料は実質的に大きな熱容量の熱媒体と熱交換することになるので、定常状態における温度の安定性を高めることができる。しかして、燃料タンク７１、燃料配管７２、および採取通路２内の燃料は、雰囲気温度が設定温度に対して±５°Ｃ内のときでも、例えば０．１°Ｃの温度変化幅で等温にできる。
【００５７】
図１０は、温度調整部５による燃料の温度変化幅が０．１°Ｃのときの採取通路２および細管３内の燃料体積と体積膨張率（計測誤差）の関係を求めた図である。供試液は燃料の主成分であるペンタンである。上記燃料体積に比例して計測誤差が大きくなることが分かる。
【００５８】
試験対象物が燃料噴射弁の場合では、計測すべき漏洩する液量はおよそ０．５ｍｍ³ であることから、本実施形態では、温度による計測誤差は計測液量の１／１０以下とすることを目標とした。このとき、採取通路２および細管３内の燃料体積は図より２６０ｍｍ³ 以下であれば、この条件を満たす。このように、温度調整部５を設けることで、採取通路２をさ程、短くすることなく、高い計測精度を得ることができる。したがって、基台９上の保持装置８、細管３、レーザ式変位センサ４のレイアウトが楽になり、試験対象物１が大型化しても対応することができる。
【００５９】
なお、上記保持装置８等のレイアウトをそのままに、さらに計測精度を高めるには、本実施形態のごとく、計測時に採取通路２と通路７５とを遮断する遮断弁７６を基台９内部に埋め込み上記燃料体積を小さくするのが効果的である。
【００６０】
次いでステップＳ４に進み気泡の混入を判定する。図７は、気泡混入判定時における状態を示すものである。図６の状態から先ず、シャッター９４を右方へスライドして退避せしめ、遮断弁７３を閉じて試験対象物１を燃料タンク７１から分離する。三方弁６８をランド側に切り替えて試験対象物１を台部９２上にランドせしめ、試験対象物１の先端部１１により採取口２０１を液密裡に覆う。
【００６１】
その後、三方弁６７を、ガスボンベ６０からのガス圧力を細管３内に供給する加圧側に切り替え、ガス圧力を図中、破線で示すように細管３内の燃料に印加する。この時、レギュレータ６５の設定圧力と大気圧の差により、細管３および採取通路２内における気泡の混入量に応じて細管３内の液面は下方へ変位する。
【００６２】
図１１は、採取通路２および細管３内の燃料体積が２６０ｍｍ³ の場合で、レギュレータ６５の設定圧力が１００ｋＰa の時の気泡混入率と燃料の体積変化の関係を示すもので、気泡混入率と燃料体積の変化とが線形に対応している。なお供試液は上記ベンタンである。
【００６３】
気泡混入率が増加するにしたがい加圧時の体積の変化は大きくなる。
【００６４】
気泡の混入の判定は、例えば、計測において影響のない０．１％の気泡混入率を閾値とし、それに相当する体積変化よりも大きいか小さいかによって判定する。上記燃料体積の例では図示のように０．１％の気泡混入率は０．１７ｍｍ³ に相当する。
【００６５】
なお、燃料の体積が小さくなると、気泡混入率に対する体積変化率の傾きも、図中、破線で示すように小さくなり、燃料の体積が大きくなると、気泡混入率に対する体積変化率の傾きも大きくなるが、その時においても、判定の閾値は、気泡混入率で０．１％とする。
【００６６】
ステップＳ４において気泡の混入なしと判定された場合は、ステップＳ５に進み、気泡の混入ありと判定された場合は、ステップＳ２に戻り採取通路２および細管３への燃料の充填からやり直す。
【００６７】
図８は、ステップＳ５の計測における状態を示すものである。
【００６８】
三方弁６７を再び大気開放側に切り替え、細管３内を大気圧に減圧する。その後、遮断弁７３を開き、試験対象物１にガス圧力を供給すると、試験対象物１の噴射口１１１から、試験対象物１の弁部における液密性に応じて燃料が漏洩し、採取通路２へ侵入する。従来の装置のように充填燃料の加圧にポンプを用いないから、ポンプの発熱で燃料温度が上昇することが防止され、燃料の熱膨張による計測誤差を低減することができる。
【００６９】
細管３は、液面が試験対象物１から漏洩した燃料の分、上昇する。一定時間当たりの液面上昇量をレーザ変位センサ４により計測し、これに細管３の通路断面積を乗じて漏洩した液量を算出し、単位時間当たりの漏洩量とする。
【００７０】
細管３の、レーザ光線の入射側および出射側の管壁３０１，３０２を含む管壁３０１〜３０４を平板状に成形するとともにこれを平行に配置したので、細管に丸管を用いた従来の装置のような、細管の曲面部における屈折の影響による散逸等がなく、レーザ式変位センサ４の発光部４１からのレーザ光線は、そのまま水平に細管３を横切り受光部４２に達する。これにより、細管３内の燃料の液面検出が高精度に行える。
【００７１】
また、細管３の内側表面は、研磨により、レーザ光線の入射側および出射側の管壁３０１，３０２における屈折をより好適に防止するとともに、細管３内の通路断面積を、均一に、例えば１％の幅内に入れている。このように、細管３内の通路断面積の精度を上げることで、漏洩燃料の量が液面の変位量に通路断面積を乗じて簡単に得られる。すなわち、計測精度を上げるために、製作された細管ごとにメスシリンジ等を用いて液面位置と漏洩燃料について換算マップを作る必要がなく、低コストにできる。
【００７２】
計測（ステップＳ５）が終了した後、ステップＳ６で再計測を行うか否かを選択する。再計測を行う場合はステップＳ７で初期液面調整を行った後、再びステップＳ３に進む。
【００７３】
図９はステップＳ７の初期液面調整における状態を示すものである。先ず、三方弁６４を大気開放側に切り替えて、燃料タンク７１内およびこれと連通している試験対象物１内を減圧し大気圧とする。その後、遮断弁７３を閉じ試験対象物１を燃料タンク７１から分離する。
【００７４】
この作動が終了した後、三方弁６９をリフト側に切り替え、試験対象物１を台部９２からリフトする。この試験対象物１のリフトにより採取口２０１が開き、採取通路２は廃液皿９１と通じる。細管３上部と廃液皿９１とはともに大気開放であるため、２つの液面は釣り合おうとする。廃液皿９１の液面は排出口９３で規定されているから、液面が釣り合うまで燃料が排出口９３から排出され、計測時に上昇した細管３内の液面を初期の液面位置へ迅速に戻すことができる。
【００７５】
このように、レーザ式変位センサ４の計測値をモニターしながら採取通路２および細管３内の燃料の調整をしなくとも、計測時に液面が上昇した分の燃料が、採取通路２および細管３内から排出されるので、細管３の液面の初期化が簡便に行える。
【００７６】
なお、細管３の内側表面の撥水コーティングにより、細管３内の液面初期化時において、細管３の内側の表面３ｃ〜３ｆ（図２）は液切れがよくなる。したがって、従来の装置のような、前の計測時に細管の内側表面に付着した付着量の一定しない試験液による光の屈折の影響は生じず、次の計測に即座に移ることができる。したがって高い計測精度と、計測の迅速性とを両立させることができる。
【００７７】
なお、細管３は、ガラス製ではなく、やや透過率や屈折率の点でガラスに劣るものの樹脂製とすることもできる。この場合、複数の縦割りした管壁部材で構成するのではなく、簡単に型成形により一体に成形してもよい。
【００７８】
また、光線が入射または出射しない管壁３０３，３０４（図２）は、必ずしも平行に配置する必要はなく、また、細管の通路断面積の均一性が十分であれば、平板状でなくともよい。
【００７９】
ステップＳ６において再計測を行わない方が選択された場合は、ステップＳ８で試験対象物１を変更するか否かを選択する。変更する場合は、ステップＳ９にて固定治具８２に固定される試験対象物１を新しいものに取り替えた後、再びステップＳ３に進む。試験対象物１を変更しない場合は、これにて一連の計測作動を終了する（ステップＳ１０）。
【００８０】
なお、漏洩量の検出感度を高めるには、細管の通路断面積を小さくして漏洩量に対して細管内の液面変化が大きく現れるようにする。その場合、後述するように、入射側管壁および出射側管壁の幅を入射側管壁および出射側管壁の対向間隔よりも広くして、細管の通路断面の形状がレーザ光線の進行方向から見て幅広となるようにするのがよい。
【００８１】
図１２はかかる細管の製造各工程における細管の断面を示すもので、細管３Ａは複数の縦割りしたガラス製の管壁部材から細管３と実質的に同じ製造各工程を経て完成する。図１２の（１），（２），（３）に管壁部材の断面形状の異なる３つの例を示している。（１）では平板状の管壁部材３１Ａと断面コ字状の管壁部材３２Ａとから製作され、管壁部材３２Ａの凹部の断面形状を長方形とすることで、完成時に形成される通路が断面長方形となる。（２）では断面Ｌ字状の管壁部材３３Ａ，３４Ａとから製作され、凸部の幅を小さめに凸部の高さを低めにすることで、完成時に形成される通路が断面長方形となる。（３）では広幅で平板状の管壁部材３５Ａ，３６Ａと狭幅で平板状の管壁部材３７Ａ，３８Ａとから製作され、管壁部材３７Ａ，３８Ａの幅を小さめに厚さを薄めにすることで、完成時に形成される通路が断面長方形となる。そして発光部４１からのレーザ光線が、細管３Ａの上記通路を形成する四方の管壁３０５，３０６，３０７，３０８のうち、長辺側の例えば管壁３０５から入射しその反対側の管壁３０６から出射するように、かつレーザ光線の進行方向と長辺側管壁３０５，３０６の各面とが直交するように、細管３Ａを配置する。
【００８２】
細管３Ａをかかる構成とすることで、次の効果を奏する。図１３、図１４は帯状のレーザ光線が通路断面が正方形の細管３を透過する様子を示すもので、図中、Ｘ１は細管３の通路部分の中心線である。本来、レーザ光線Ｌは、図１３に示すように入射側管壁３０１に垂直に入射し反対側の出射側管壁３０２を抜けていく。しかし、図１４に示すようにレーザ光線Ｌのなす面が上記中心線Ｘ１に対して傾斜していると、レーザ光線Ｌの一部（図例ではレーザ光線Ｌの上側半部）が細管３内を通過しないで管壁３０３，３０４（図例では３０３）を通過し、この位置での液面検出が不可能となる。
【００８３】
したがって、細管３と発光部４１との間の位置合わせが重要になるが、漏洩量の検出感度を上げるべく細管３の通路断面を狭くすると、レーザ光線Ｌの許容される細管３の幅方向のずれが小さくなり、帯状に照射されるレーザ光線Ｌが、その一方の端から他方の端まで、対向する入射側管壁３０１および出射側管壁３０２を通るように、レーザ光線Ｌのなす面の上記中心線Ｘ１に対する傾斜角をより小さくしなければならない。細管３の通路断面を狭くすると相対的に漏洩量に対する液面上昇量が大きくなり、発光部４１のレーザ光線Ｌの液面変位方向の長さも相対的に広げる必要が生じるので、余計、発光部４１と細管３の位置合わせが困難となる。
【００８４】
一方、細管３Ａでは、通路断面の形状を幅方向が広い長方形としたから、図１５に示すように、発光部４１が細管３Ａの通路部分の中心線Ｘ２に対して傾斜しレーザ光線Ｌの一方の端と他方の端とが通路断面の幅方向にずれていても、その許容可能なずれを大きくとることができ、発光部４１と細管３Ａの位置合わせが容易となる。
【００８５】
なお、同じ通路断面積で入射側管壁および出射側管壁の幅をなるべく広くするには通路断面の形状は図１２のように長方形とするのがよいが、図１６の（１）、（２）、（３）、（４）にそれぞれ示すように、細管３Ｃ，３Ｄ，３Ｅ，３Ｆの通路の非レーザ光線透過面である短辺側の面（図中、上下面）が膨出する形状としてもよい。図中、Ｌ１はレーザ光線の進行経路である。また、細管の外形も必ずしも断面矩形とする必要はなく、図例の細管３Ｄ，３Ｆのように角を落とした形状としてもよい。少なくともレーザ光線が通る入射側管壁および出射側管壁の各面が平行になっておればよい。
【００８６】
（第２実施形態）
図１７、図１８に本発明の第２実施形態になる液密計測装置を示す。第１実施形態の構成において、細管と、基台に形成された温調配管の下流部を別の構成としたもので、図中、第１実施形態と実質的に同じ作動をする部分には同じ番号を付し、第１実施形態との相違点を中心に説明する。
【００８７】
細管３Ｇは図１８に示すように、通路の断面形状が長方形のもので、図１２（１）のごとく断面コ字状の管壁部材と断面長方形の管壁部材とからなり、発光部４１からのレーザ光線が通路の長辺側の管壁から入射し、通路を抜けて反対側の管壁から抜けるようになっている。
【００８８】
細管３Ｇには、レーザ光線の進行経路とはなっていない管壁部分に、通路と平行に２箇所に縦孔５１５ａ，５１５ｂが形成してある。
【００８９】
細管３Ｇの上端部を受ける保持部材９６は、その直線通路９６１により三方弁６７と細管３Ｇとを連通するともに、Ｕ字通路５１４により細管３Ｇの両縦孔５１５ａ，５１５ｂを連通せしめている。なお、図は細管３Ｇの両縦孔５１５ａ，５１５ｂおよび保持部材９６のＵ字通路５１４を９０°展開して示している。
【００９０】
基台９内部に形成された温調配管５１Ａの下流部５１３Ａは、途中が細管３Ｇの下端部を受ける凹部９５の底面で分断されており、分断端の一方は細管３Ｇの一方の縦孔５１５ａと通じ、分断端の他方は細管３Ｇの他方の縦孔５１５ｂと通じている。しかして、熱媒体ポンプ５３から送出された熱媒体は基台９内部および細管３Ｇの管壁内部を通り熱媒体タンク５２内に戻される。この循環する熱媒体により、基台９全体の温調を行うとともに、細管３Ｇの管壁の温調を行う。
【００９１】
本実施形態では、試験液である燃料や基台９だけではなく、細管３Ｇの管壁を一定温度に保つことができるので、細管３Ｇの熱膨張を防止することができ、さらに漏洩量の計測精度を向上させることができる。
【００９２】
以上のごとく、本発明の液密計測装置によれば、高い計測精度が得られ、高性能な燃料噴射弁等の検査に適用し得る。しかも上記のごとく、高い計測精度を維持したまま計測の迅速性をも高めているから、スループットを上げることができる。
【００９３】
なお、上記各実施形態では、燃料タンク７１、燃料配管７２、採取通路２の燃料と熱交換する熱交換手段を、熱媒体が循環する単一の温調配管５１により構成しているが、上記燃料タンク７１等の燃料と共通に熱交換する構成であればよい。
【００９４】
また、燃料タンク７１内を加圧する充填試験液加圧手段、細管３内を加圧する気泡検出用加圧手段は、ガスボンベ６０で構成するものに限定されるものではなく、例えば、ガス配管６１内の空気をポンピングにより高圧にしてもよい。
【００９５】
また、採取通路２は、採取口から真っ直ぐに下降して屈曲部まで延び、斜め上方に向きを変えて細管３の直下まで延び、この直下位置から他端まで真っ直ぐ上昇する形状でもよい。あるいは採取通路は、その途中の屈曲部から採取口および細管の直下位置に向けて斜め上方に延びるＶ字形でもよい。
【００９６】
また、細管３の液面初期化時に、細管３から燃料を採取通路２を逆流せしめて廃液皿９１を介して排出口９３からオーバーフローする構成としているが、細管３の下端に通じる別の排出通路を設け、その排出口を初期液面の高さに開口するように構成し、採取口を閉鎖した状態で燃料を排出通路により排出するようにしてもよい。なお、液面初期化時以外は排出口を閉鎖するか、排出通路を採取通路と遮断する。
【００９７】
なお、要求される計測精度によっては本実施形態において開示した本発明のうち、いくつかの構成については省略して装置の構成を簡単にすることも可能である。すなわち、液面検出の高精度化の優先順位が低ければ、細管は引き出し丸形管により構成することもできる。
【００９８】
また、温度変動による燃料体積の膨張、収縮防止の優先順位が低ければ、試験対象物内の燃料への加圧は、燃料を送出するポンプにより行ってもよい。また、燃料の温度調整は、試験対象物に供給する燃料、細管に導入される燃料をそれぞれ別々の温調配管により行う構成でもよい。あるいは温度調整を行う手段そのものを省略してもよい。
【００９９】
また、気泡の混入のおそれがあまりなく、計測精度の高精度化のために気泡混入防止の優先順位が低ければ、採取通路の途中部分が水平方向に形成されているのでもよい。また、混入しても混入量が小さい場合は、気泡混入の判定を行う必要はなく、細管へガスボンベからのガス圧力を印加するためのレギュレータ、三方弁は省略し、細管の上部を常に大気開放とし、装置構成を簡単にしてもよい。
【０１００】
また、細管内の初期液面位置の高精度化の優先順位が低く、細管内燃料の初期設定を手動や細管内燃料のフィードバック制御により行うことが可能であれば、これらの手段でもよい。
【図面の簡単な説明】
【図１】本発明の実施形態を示す液密計測装置の全体構成図である。
【図２】（１），（２），（３）はそれぞれ上記液密計測装置の第１の細管の製作工程を説明する横断面図である。
【図３】上記液密計測装置の作動を説明するフローチャートである。
【図４】上記液密計測装置の作動を説明する第１の作動状態における全体構成図である。
【図５】上記液密計測装置の作動を説明する第２の作動状態における全体構成図である。
【図６】上記液密計測装置の作動を説明する第３の作動状態における全体構成図である。
【図７】上記液密計測装置の作動を説明する第４の作動状態における全体構成図である。
【図８】上記液密計測装置の作動を説明する第５の作動状態における全体構成図である。
【図９】上記液密計測装置の作動を説明する第５の作動状態における全体構成図である。
【図１０】上記液密計測装置の作動を説明する第１のグラフである。
【図１１】上記液密計測装置の作動を説明する第２のグラフである。
【図１２】（１），（２），（３）はそれぞれ上記液密計測装置の第２の細管の製作工程を説明する横断面図である。
【図１３】（１）は上記第２の細管を用いた上記液密計測装置と比較する第１の細管を用いた液密計測装置の作動を説明する細管部の断面図であり、（２）は（１）におけるＡ１−Ａ１線に沿う断面図であり、（３）は（２）におけるＢ１−Ｂ１線に沿う断面図である。
【図１４】（１）は上記第２の細管を用いた上記液密計測装置と比較する第１の細管を用いた液密計測装置の作動を説明する作動状態の異なる細管部の断面図であり、（２）は（１）におけるＡ１−Ａ１線に沿う断面図であり、（３）は（２）におけるＢ１−Ｂ１線に沿う断面図である。
【図１５】（１）は上記第２の細管を用いた上記液密計測装置の作動を説明する細管部の断面図であり、（２）は（１）におけるＡ２−Ａ２線に沿う断面図であり、（３）は（２）におけるＢ２−Ｂ２線に沿う断面図である。
【図１６】（１），（２），（３），（４）はそれぞれ上記液密計測装置に用い得る細管の変形例を示す図である。
【図１７】本発明の別の実施形態を示す液密計測装置の全体構成図である。
【図１８】（１）は上記液密計測装置の細管の横断面図であり、（２）は（１）におけるＣ−Ｃ線に沿う断面図である。
【符号の説明】
１試験対象物
２採取通路
２０１採取口（一端）
２０２他端
２０３屈曲部
３，３Ａ，３Ｂ，３Ｃ，３Ｄ，３Ｅ，３Ｆ，３Ｇ細管
３１，３２，３３，３４，３５，３６，３７，３８，３１Ａ，３２Ａ，３３Ａ，３４Ａ，３５Ａ，３６Ａ，３７Ａ，３８Ａ管壁部材
３０１，３０５入射側管壁（管壁）
３０２，３０６出射側管壁（管壁）
３０３，３０４，３０７，３０８管壁
３ｃ，３ｄ，３ｅ，３ｆ内側の表面
４レーザ式変位センサ（液面検出手段）
４１発光部
４２受光部
５温度調整部（温度調整手段）
５１温調配管（熱媒体流路）
５１５ａ，５１５ｂ縦孔
５４加熱冷却手段
６ａ充填試験液加圧手段
６ｂ気泡検出用加圧手段
６０ガスボンベ
６２，６５レギュレータ
９１廃液皿（液溜まり）
９３排出口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid tightness measuring device that measures the amount of liquid that leaks when a fuel injection valve, a flow control valve, or the like is closed.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, the amount of liquid that leaks from a valve portion when a valve is closed is measured in a fuel injection valve of an internal combustion engine, a flow control valve, or the like. For example, in the case of a fuel injection valve, if the amount of leaked liquid is large, the accuracy of air-fuel ratio control is impaired, leading to an increase in the amount of exhaust gas. The liquid tightness measuring device brings the outlet of the fuel injection valve, flow control valve, etc., which are test objects, into close contact with the sampling port, fills the test object with the test liquid, pressurizes the filled test liquid, and pressurizes The test liquid leaked from the valve part in the state is collected and the amount of the liquid is measured. The collected test liquid is introduced into a thin thin round glass tube through the collection passage, and the liquid level is displaced from the liquid level displacement. The quantity is measured. The amount of the leaked liquid can be obtained based on the amount of displacement of the liquid level and the cross-sectional area of the thin tube (Japanese Patent Laid-Open Nos. 4-105019, 4-255568, and 5-66173, (Kaihei 9-88769).
[0003]
In JP-A-4-105019, JP-A-4-255568, and JP-A-9-88769, an optical liquid that transmits light across a thin tube and detects the liquid level based on the transmitted light. By providing the surface detection means, it is possible to automate the measurement of the leakage amount and to prevent measurement variations by the operator. In the apparatus described in Japanese Patent Laid-Open No. 9-88769, automation is promoted by sending a test liquid to a test object by a pump, filling and pressurizing it.
[0004]
[Problems to be solved by the invention]
However, the inventions described in the above publications mainly focus on automation of liquid-tightness measurement, and it is impossible to know the amount of leaked liquid with high accuracy with respect to a high-performance fuel injection valve or flow control valve with little leakage. . Further, if the measurement accuracy of the leaked liquid amount is not sufficient, the fuel injection valve may not be able to sufficiently cope with the stricter exhaust gas regulations.
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid tightness measuring apparatus with high measurement accuracy of a leaked liquid amount.
[0006]
[Means for Solving the Problems]
  The invention of the present application is a sampling port in which a test liquid leaking from a liquid-tight portion of a test object is formed at one end of a sampling passage in a state where the test liquid filled in the test object is pressurized by a filling test liquid pressurizing means. And is introduced into a transparent thin tube connected to the other end of the sampling passage, and the liquid level detecting means irradiates light from the light emitting portion so as to cross the thin tube, and the light is detected by the light receiving portion. In accordance with the invention, the liquid level of the test liquid in the narrow tube is detected and the amount of the test liquid leaked from the liquid tight part from the change in the liquid level is measured.A temperature adjusting means for controlling the temperature of the test solution is provided. The temperature adjusting means includes heat exchange means for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the thin tube. The heat exchange means is a heat exchange means common to these test solutions.
  In the present invention, by adopting the above configuration, the heat is exchanged by the common heat exchange means between the test liquid supplied to the test object and the test liquid introduced into the narrow tube, and the temperature is adjusted. The temperature difference between the test solutions can be reduced and the measurement accuracy can be increased.
[0019]
  AlsoClaim1In the described invention, the heat exchanging means has a configuration in which a vertical hole is formed inside the tube wall of the thin tube, and a heat medium that exchanges heat with the thin tube wall is circulated in the vertical hole.
[0020]
By controlling the temperature of the tube wall of the thin tube, the thermal expansion and contraction of the thin tube can be prevented even if the apparatus installation atmosphere fluctuates, so that the measurement accuracy can be further improved.
[0023]
  Claim2In the described invention,A temperature adjusting means for controlling the temperature of the test liquid is provided, and heat exchange means for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the thin tube is provided,The sampling passage has a shape that extends upward from the bent portion at the lowest position and reaches the one end and the other end.
[0024]
By not providing a part formed in the horizontal direction or a part bent in a mountain shape in the collection passage, bubbles do not stay in the collection passage. Therefore, measurement errors due to the presence of bubbles can be prevented.
[0025]
  Claim3In the described invention,A temperature adjusting means for controlling the temperature of the test liquid is provided, and heat exchange means for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the thin tube is provided,A bubble detecting means for pressurizing the sample passage and the test liquid in the narrow tube at the time of non-measurement is provided, and the mixing amount of bubbles in the test liquid is detected based on the displacement amount of the test liquid level during pressurization.
[0026]
The bubbles in the collection passage and the narrow tube are compressed by pressurizing the test liquid, and the test liquid level in the thin tube is lowered. Since this descending amount is proportional to the amount of bubbles, the amount of bubbles can be known quantitatively and high measurement accuracy can be obtained.
[0027]
  Claim4In the described invention,A temperature adjusting means for controlling the temperature of the test liquid is provided, and heat exchange means for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the thin tube is provided,A narrow tube is erected from the other end of the sampling passage, and is connected to the lower end of the thin tube, and after the measurement of the leakage test solution, a discharge passage is provided for discharging the test solution in the narrow tube to the outside of the narrow tube. Is opened at a predetermined initial liquid level which is a reference for measuring the leakage test liquid.
[0028]
After measurement of the leak test liquid, it is necessary to discharge the test liquid and return the liquid level in the narrow tube to a predetermined initial liquid level in preparation for the next measurement. However, it is not easy to adjust the amount of the test liquid so that it becomes the initial liquid level, whether it is manual control or the metering control by liquid level detection, and a measurement error occurs due to variations in the initial liquid level. In the present invention, after the measurement, the test liquid in the thin tube is discharged from the discharge port by its own weight, and the liquid level in the thin tube tries to balance with the height of the discharge port. By opening the discharge port at the height of the initial liquid level, the liquid level in the narrow tube is set to the initial liquid level with high accuracy. In addition, the configuration of the apparatus is simple because a control system for that purpose is unnecessary.
[0029]
  Claim5In the described invention,In the configuration of the invention according to claim 4,The sampling port of the sampling passage is provided below the initial liquid level of the capillary tube, and when the liquid tight part of the test object is removed from the sampling port, the test solution flowing backward from the capillary tube flows and the test solution is stored. The liquid reservoir is provided so as to overflow at the height of the initial liquid level, and the discharge passage is constituted by the collection passage and the liquid reservoir.
[0030]
Since the collection passage becomes the discharge passage after the measurement, the configuration of the apparatus can be further simplified.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
In FIG. 1, the structure of the liquid-tight measuring apparatus which becomes 1st Embodiment of this invention is shown. The liquid-tight measuring device is based on a holding device 8 that holds a test object 1 on a base 9, a thin tube 3 that introduces a test liquid leaked from the test object 1, and a liquid level displacement of the thin tube 3. 1 has a laser displacement sensor 4 serving as a liquid level detecting means for measuring the amount of liquid leaked from 1. The test object 1 is a fuel injection valve of an internal combustion engine in the present embodiment.
[0032]
The test object 1 is fixed to a fixing jig 82 having a U-shaped cross section of the holding device 8 with the distal end portion 11 facing downward, and the distal end portion 11 projects downward from the bottom plate of the fixing jig 82. The test object 1 is supplied with fuel as a test solution from the fuel tank 71 via the filling pipe 72, and the fuel is supplied into the test object 1. The test object 1 is connected to a control device (not shown) that drives the test object 1 so that the valve can be switched between opening and closing.
[0033]
In the holding device 8, a track portion 81 integrated with the base 9 holds a fixing jig 82 to which the test object 1 is fixed so as to be movable up and down. A cylinder 83 is formed by the track portion 81 and the fixing jig 82, and a spool 821 protruding from the side surface of the fixing jig 82 is displaced in the cylinder 83. A compressive gas such as air or nitrogen is introduced into the cylinder 83 from the gas cylinder 60 through the regulator 68 and the three-way valve 69 in the space above and below the spool 821. By switching the three-way valve 69, the spool 821 is pressed from the upper side or the lower side by the gas pressure, thereby pushing the spool 821 up to the upper end position or down to the lower end position. Thereby, it is possible to switch between a land on the platform 92 and a lift from the platform 92 to be described later.
[0034]
On the other hand, a waste liquid tray 91 that stores liquid is provided at the top of the base 9, and a base 92 is provided at the bottom of the base 9 so as to face the tip 11 of the test object 1.
[0035]
In addition, a U-shaped sampling passage 2 is formed inside the base 9, one end of which opens to the top surface of the base portion 92 as a sampling port 201, and the other end 202 is for attaching the thin tube 3. An opening is formed in the bottom surface of the recess 95.
[0036]
The sampling port 201 is a liquid-tight portion of the test object 1 such that when the test object 1 is landed, the front end surface of the test object 1 is closed in close contact with the top surface of the base 92. Fuel leaking from the valve portion is collected from the injection port 111. A sealing O-ring is provided at the peripheral edge of the sampling port 201 to maintain liquid tightness between the test object 1 and the base 92.
[0037]
In addition, a shutter 94 is provided in the waste liquid tray 91 and is inserted between the test object 1 and the base 92 when the test object 1 is lifted. The shutter 94 is a flat plate having a diameter larger than that of the sampling port 201, and is configured to slide in a horizontal direction so as to freely move forward and backward. The shutter 94 covers the sampling port 201 when advanced leftward and retracts to the right when the test object 1 is retracted. Land becomes possible.
[0038]
The thin tube 3 is arranged upright on the base 9. The lower end portion of the thin tube 3 is fitted into the recess 95 of the base 9, and the thin tube 3 and the sampling passage 2 are communicated with each other at the lower end. As will be described later, a predetermined amount of fuel is supplied to the narrow tube 3 and the sampling passage 2 before measurement, and the liquid level of the fuel in the narrow tube 3 is set to the initial liquid level. The liquid level rises from the initial liquid level according to the amount of fuel from the injection port 111 of the test object 1 during measurement. The amount of fuel leaked from this increased amount is known.
[0039]
FIG. 2 is a cross-sectional view of a thin tube in each process of manufacturing the thin tube 3. The thin tube 3 is not a drawn round tube as in the prior art but is a square tube, and is manufactured from a plurality of vertically divided glass tube wall members. . (1), (2), and (3) show three examples in which the shape of the tube wall member is different. In (1), it is manufactured from a flat tube wall member 31 and a U-shaped tube wall member 32. In (2), it is manufactured from L-shaped tube wall members 33, 34. In (3), The wide and flat tube wall members 35 and 36 and the narrow and flat tube wall members 37 and 38 are manufactured. As shown in the drawing, the tube walls 301, 302, 303 and 304 are curved surfaces. The pipe wall 301 and the pipe wall 302 facing each other, and the pipe wall 303 and the pipe wall 304 are combined so as to be arranged in parallel.
[0040]
Moreover, after each tube wall member 31-38 is shape | molded by the predetermined shape like a figure, among the outer surfaces, the surface 3a in which a laser beam injects, the surface 3b in which it radiate | emits, and inner surface 3c, 3d, 3e , 3f is flattened by polishing to obtain a highly accurate flat surface.
[0041]
After the polishing, the tube wall members 31 to 38 are fused at a high temperature.
[0042]
The thin tube 3 is completed by forming a water-repellent coating on the inner surfaces 3c to 3f.
[0043]
The sampling passage 2 descends straight from the sampling port 201, changes its direction obliquely downward, extends to the bent portion 203 directly below the narrow tube 3, and rises straight from the bent portion 203 to the other end 202.
[0044]
Another connecting passage 75 that is branched obliquely downward from the bent portion 203 of the sampling passage 2 is formed. The connection passage 75 is connected to the fuel pipe 74 so that fuel is supplied from the fuel tank 71 into the sampling passage 2 and the narrow pipe 3 via the fuel pipe 74.
[0045]
A shutoff valve 76 is provided closest to the collection passage 2 of the connection passage 75 so as to switch communication between the collection passage 2 and the passage 75 and shut off. The shut-off valve 76 is opened when the apparatus is started up, the initial liquid amount is supplied into the collection passage 2 and the narrow tube 3, and is closed during measurement.
[0046]
The laser displacement sensor 4 includes a light emitting unit 41 and a light receiving unit 42. The light emitting unit 41 is configured to irradiate a laser beam in a band shape from a predetermined range in the vertical direction, and is irradiated so that the laser beam crosses the narrow tube 3 in the horizontal direction at each height of the narrow tube 3. The light receiving unit 42 is constituted by a line CCD or the like arranged in the vertical direction, and detects a light beam that traverses and passes through the thin tube 3 at each height of the thin tube 3. From the discontinuous part of the detection light intensity in the light receiving part 42, the liquid level of the fuel in the thin tube 3 is detected. Further, the light emitting section 41 and the thin tube 3 are arranged so that the laser beam is irradiated in a direction perpendicular to the incident side tube wall 301 of the thin tube 3, and the traveling path of the laser beam is set to the incident side tube wall 301 and the output side tube wall. It is taken to be orthogonal to 302. This prevents the polarization and irregular reflection of the laser beam and enhances the detection accuracy of the fuel liquid level.
[0047]
The fuel tank 71 is supplied with the compressed gas from a gas cylinder 60 from a gas pipe 61 and further via a regulator 62 and a three-way valve 64. Further, the gas in the fuel tank 71 is discharged through the gas pipe 63 opened to the atmosphere by switching the three-way valve 64 and is reduced to atmospheric pressure. The gas cylinder 60, the gas pipe 61, the regulator 62, and the three-way valve 64 constitute a filling test solution pressurizing means 6a.
[0048]
Further, the compressible gas in the gas cylinder 60 passes from the gas pipe 61 and further through the regulator 65 and the three-way valve 67 to the narrow pipe 3 from the upper end of the thin pipe 3 through the straight passage 961 formed in the holding member 96 that receives the upper end of the thin pipe 3. It comes to be supplied. In addition, the inside of the narrow tube 3 is opened to the atmosphere via the gas pipe 66 by switching the three-way valve 67. The gas cylinder 60, the gas pipe 61, the regulator 65, and the three-way valve 67 constitute a bubble detecting pressurizing means 6b.
[0049]
In addition, the liquid tightness measuring apparatus includes a fuel tank 71, a supply pipe 72, and a temperature control unit 5 that is a temperature adjusting unit that adjusts the temperature of the fuel in the collection passage 2. The temperature control unit 5 includes a temperature control pipe 51 and a tank 52 that are heat medium channels through which the heat medium circulates, and a heating and cooling unit 54 that is a heating and cooling unit that heats and cools the heat medium.
[0050]
The heat medium in the tank 52 is sent to the upstream part 511 of the temperature control pipe 51 by the pump 53 and forms a circulation path that returns to the tank 52 from the downstream part 513 again. The temperature control pipe 51 is immersed in the fuel stored in the fuel tank 71 in the upstream part 511, the midstream part 512 is disposed on the outer periphery of the fuel pipe 72, and the downstream part 513 is a base on which the sampling passage 2 is formed. 9, the heat medium circulating in the temperature control pipe 51 exchanges heat in common with the fuel in the fuel tank 2, the fuel pipe 72, and the collection passage 2.
[0051]
In the heating / cooling unit 54, the electric heater 541 and the water cooler 542 heat or cool the heat medium in the tank 52 to adjust the temperature of the heat medium.
[0052]
The operation of the liquid tightness measuring apparatus will be described. FIG. 3 is a flowchart showing the measurement procedure, and FIGS. 4, 5, 6, 7, 8, and 9 show the operating state of the liquid-tightness measuring device in each measurement procedure. The operation starts in step S1. FIG. 4 shows a state at the start of operation. The three-way valves 64 and 67 are set on the open side where the narrow pipe 3 and the fuel tank 71 communicate with the discharge pipes 63 and 66. Further, the three-way valve 69 is set on the lift side where the spool 821 is pushed upward to lift the test object 1. The shutter 94 is retracted to the right. The shut-off valves 73 and 76 are “closed”.
[0053]
FIG. 5 shows the state at the time of fuel filling in the subsequent step S2. The three-way valve 64 is switched from the state of FIG. 4 to the pressurizing side where the gas pressure from the gas cylinder 60 is supplied into the fuel tank 71. Pressurize the fuel inside. The shutter 94 is slid leftward and inserted between the test object 1 and the sampling port 201. Next, the shutoff valve 76 is opened. The fuel in the fuel tank 71 is supplied into the collection passage 2 by the gas pressure supplied into the fuel tank 71 as shown by the dotted arrow in the figure. The fuel is ejected from the sampling port 201, flows along the lower surface of the shutter 94, and accumulates in the waste liquid tray 91, and the liquid level rises. When the liquid level reaches the height of the discharge port 93 of the waste liquid tray 91, the surplus fuel overflows and is discharged from the discharge port 93, and the rise of the liquid level stops. At this time, the liquid level L1 of the fuel in the narrow tube 3 also stops at the height of the discharge port 93. In this way, a predetermined amount of initial fuel can be filled into the collection passage 2 and the narrow tube 3 without using a fuel metering means.
[0054]
Now, as described above, the collection passage 2 is filled with the initial fuel, but the collection passage 2 has a shape extending upward from the bent portion 203 and reaching the one end 201 and the other end 202 as described above. Air bubbles are prevented from staying in the collection passage 2. If bubbles remain, the amount of increase in the liquid level in the narrow tube 3 is larger than that of the actually leaked fuel, which causes a measurement error. However, as described above, leakage occurred by preventing the bubbles from staying. Fuel measurement accuracy can be increased.
[0055]
Next, the process proceeds to step S3. FIG. 6 shows the state when the test object is driven in step S3. From the state of FIG. 5, first, the shutoff valve 76 is closed and the sampling passage 2 and the narrow tube 3 side and the passage 75 side are shut off. Next, the shut-off valve 73 is opened to allow communication between the fuel tank 71 and the test object 1, and the test object 1 is driven to fill the test object 1 with fuel. When the test object 1 is opened, the fuel falls onto the upper surface of the shutter 94 and accumulates in the waste liquid tray 91, but excess fuel at a liquid level exceeding the discharge port 93 is discharged from the discharge port 93.
[0056]
Further, the temperature of the fuel in the fuel tank 2, the fuel pipe 72, and the collection passage 2 is adjusted by the operation of the temperature adjusting unit 5 and is kept constant. Here, since the heat medium that exchanges heat with the fuel is common to the fuel supplied to the test object 1 and the fuel introduced into the narrow tube 3, the temperature difference between the two fuels is reduced, the expansion of the fuel volume, Shrinkage is suppressed and the measurement accuracy of leaked fuel can be increased. In addition, since each of the fuels exchanges heat with a heat medium having a substantially large heat capacity, temperature stability in a steady state can be improved. Accordingly, the fuel in the fuel tank 71, the fuel pipe 72, and the sampling passage 2 is made isothermal with a temperature change width of, for example, 0.1 ° C. even when the ambient temperature is within ± 5 ° C. with respect to the set temperature. it can.
[0057]
FIG. 10 is a diagram in which the relationship between the fuel volume in the sampling passage 2 and the thin tube 3 and the volume expansion rate (measurement error) when the temperature change width of the fuel by the temperature adjusting unit 5 is 0.1 ° C. is obtained. The test solution is pentane, the main component of fuel. It can be seen that the measurement error increases in proportion to the fuel volume.
[0058]
When the test object is a fuel injection valve, the amount of leaked liquid to be measured is approximately 0.5 mm.^Three Therefore, in the present embodiment, the measurement error due to temperature is targeted to be 1/10 or less of the measured liquid amount. At this time, the fuel volume in the sampling passage 2 and the narrow tube 3 is 260 mm from the figure.^Three This condition is satisfied if: As described above, by providing the temperature adjustment unit 5, it is possible to obtain high measurement accuracy without shortening the sampling passage 2 so much. Therefore, the layout of the holding device 8, the thin tube 3, and the laser displacement sensor 4 on the base 9 becomes easy, and it is possible to cope with an increase in the size of the test object 1.
[0059]
In order to further improve the measurement accuracy while maintaining the layout of the holding device 8 and the like, a shutoff valve 76 that shuts off the sampling passage 2 and the passage 75 during measurement is embedded in the base 9 as in the present embodiment. It is effective to reduce the fuel volume.
[0060]
Next, the process proceeds to step S4 to determine whether air bubbles are mixed. FIG. 7 shows a state at the time of bubble mixing determination. First, the shutter 94 is slid to the right and retracted from the state of FIG. 6, the shutoff valve 73 is closed, and the test object 1 is separated from the fuel tank 71. The three-way valve 68 is switched to the land side so that the test object 1 is landed on the pedestal 92, and the sampling port 201 is covered in a liquid-tight manner by the tip 11 of the test object 1.
[0061]
Thereafter, the three-way valve 67 is switched to the pressurizing side for supplying the gas pressure from the gas cylinder 60 into the narrow tube 3, and the gas pressure is applied to the fuel in the narrow tube 3 as indicated by a broken line in the figure. At this time, due to the difference between the set pressure of the regulator 65 and the atmospheric pressure, the liquid level in the narrow tube 3 is displaced downward according to the amount of bubbles mixed in the narrow tube 3 and the sampling passage 2.
[0062]
FIG. 11 shows that the fuel volume in the sampling passage 2 and the narrow tube 3 is 260 mm.^Three In this case, the relationship between the bubble mixing rate and the fuel volume change when the set pressure of the regulator 65 is 100 kPa is shown, and the bubble mixing rate and the change in the fuel volume correspond linearly. The test solution is the above bentan.
[0063]
As the bubble mixing rate increases, the volume change during pressurization increases.
[0064]
The determination of the mixing of bubbles is made, for example, based on whether the bubble mixing rate of 0.1% that does not affect the measurement is used as a threshold value and is larger or smaller than the corresponding volume change. In the above fuel volume example, as shown in the figure, the bubble mixing rate of 0.1% is 0.17 mm.^Three It corresponds to.
[0065]
As the fuel volume decreases, the slope of the volume change rate with respect to the bubble mixture rate also decreases as shown by the broken line in the figure. When the fuel volume increases, the slope of the volume change rate with respect to the bubble mixture rate also increases. However, even at that time, the determination threshold is set to 0.1% in terms of the bubble mixture rate.
[0066]
If it is determined in step S4 that bubbles are not mixed, the process proceeds to step S5. If it is determined that bubbles are mixed, the process returns to step S2 and starts again from filling of the sampling passage 2 and the thin tube 3 with fuel.
[0067]
FIG. 8 shows a state in the measurement in step S5.
[0068]
The three-way valve 67 is again switched to the atmosphere opening side, and the inside of the narrow tube 3 is reduced to atmospheric pressure. Thereafter, when the shut-off valve 73 is opened and the gas pressure is supplied to the test object 1, fuel leaks from the injection port 111 of the test object 1 according to the liquid tightness in the valve portion of the test object 1, and the sampling passage Invade 2 Since the pump is not used to pressurize the filled fuel as in the conventional apparatus, the fuel temperature is prevented from rising due to heat generated by the pump, and measurement errors due to the thermal expansion of the fuel can be reduced.
[0069]
The capillary tube 3 rises by the amount of fuel whose liquid level has leaked from the test object 1. The amount of liquid level rise per fixed time is measured by the laser displacement sensor 4, and the amount of leaked liquid is calculated by multiplying this by the passage cross-sectional area of the narrow tube 3, and is defined as the amount of leakage per unit time.
[0070]
Since the tube walls 301 to 304 including the tube walls 301 and 302 on the laser beam incident side and the emission side of the narrow tube 3 are formed into a flat plate shape and arranged in parallel, a conventional apparatus using a round tube for the narrow tube The laser beam from the light emitting unit 41 of the laser displacement sensor 4 crosses the thin tube 3 as it is and reaches the light receiving unit 42 as it is. Thereby, the liquid level of the fuel in the narrow tube 3 can be detected with high accuracy.
[0071]
Further, the inner surface of the thin tube 3 is more preferably prevented from being refracted in the tube walls 301 and 302 on the incident side and the exit side of the laser beam by polishing, and the passage cross-sectional area in the thin tube 3 is made uniform, for example, 1 % Is within the range. Thus, by increasing the accuracy of the passage cross-sectional area in the narrow tube 3, the amount of leaked fuel can be easily obtained by multiplying the displacement amount of the liquid level by the passage cross-sectional area. That is, in order to increase the measurement accuracy, it is not necessary to make a conversion map for the liquid level position and the leaked fuel using a scalpel syringe or the like for each manufactured thin tube, and the cost can be reduced.
[0072]
After the measurement (step S5) is completed, it is selected whether or not remeasurement is performed in step S6. When performing re-measurement, after performing initial liquid level adjustment at step S7, it progresses to step S3 again.
[0073]
FIG. 9 shows a state in the initial liquid level adjustment in step S7. First, the three-way valve 64 is switched to the atmosphere open side, and the pressure in the fuel tank 71 and the test object 1 communicating with the fuel tank 71 is reduced to atmospheric pressure. Thereafter, the shut-off valve 73 is closed and the test object 1 is separated from the fuel tank 71.
[0074]
After this operation is completed, the three-way valve 69 is switched to the lift side, and the test object 1 is lifted from the platform 92. The collection port 201 is opened by the lift of the test object 1, and the collection passage 2 communicates with the waste liquid tray 91. Since the upper part of the thin tube 3 and the waste liquid tray 91 are both open to the atmosphere, the two liquid levels try to balance. Since the liquid level of the waste liquid tray 91 is defined by the discharge port 93, the fuel is discharged from the discharge port 93 until the liquid level is balanced, and the liquid level in the narrow tube 3 that has risen at the time of measurement is quickly returned to the initial liquid level position. Can be returned.
[0075]
Thus, even if the fuel in the sampling passage 2 and the narrow tube 3 is not adjusted while monitoring the measurement value of the laser displacement sensor 4, the fuel corresponding to the rise in the liquid level during the measurement is collected in the sampling passage 2 and the thin tube 3. Since the liquid is discharged from the inside, the liquid surface of the thin tube 3 can be easily initialized.
[0076]
In addition, the water repellent coating on the inner surface of the thin tube 3 allows the inner surfaces 3c to 3f (FIG. 2) of the thin tube 3 to be easily drained when the liquid surface in the thin tube 3 is initialized. Therefore, there is no influence of light refraction caused by the test solution having a non-constant amount adhering to the inner surface of the thin tube during the previous measurement as in the conventional apparatus, and the next measurement can be immediately performed. Therefore, it is possible to achieve both high measurement accuracy and quick measurement.
[0077]
Note that the thin tube 3 is not made of glass but can be made of resin although it is slightly inferior to glass in terms of transmittance and refractive index. In this case, instead of a plurality of vertically divided tube wall members, they may be formed integrally by simple molding.
[0078]
Further, the tube walls 303 and 304 (FIG. 2) where the light beam does not enter or exit are not necessarily arranged in parallel, and may not be flat if the cross-sectional area of the narrow tube is sufficiently uniform. .
[0079]
If it is selected in step S6 that the re-measurement is not performed, it is selected whether or not the test object 1 is to be changed in step S8. In the case of changing, after the test object 1 fixed to the fixing jig 82 is replaced with a new one in step S9, the process proceeds to step S3 again. If the test object 1 is not changed, the series of measurement operations is finished (step S10).
[0080]
In order to increase the detection sensitivity of the leakage amount, the passage cross-sectional area of the narrow tube is reduced so that the change in the liquid level in the narrow tube greatly appears with respect to the leakage amount. In that case, as will be described later, the width of the entrance-side tube wall and the exit-side tube wall is made wider than the interval between the entrance-side tube wall and the exit-side tube wall, and the shape of the passage section of the narrow tube is the traveling direction of the laser beam. It is better to make it wider when viewed from the side.
[0081]
FIG. 12 shows a cross-section of a thin tube in each manufacturing process of the thin tube, and the thin tube 3A is completed from a plurality of vertically divided glass tube wall members through substantially the same manufacturing steps as the thin tube 3. (1), (2), and (3) of FIG. 12 show three examples in which the cross-sectional shape of the tube wall member is different. In (1), the tube wall member 31A having a flat plate shape and a tube wall member 32A having a U-shaped cross section are manufactured. It becomes a rectangle. In (2), it is manufactured from the L-shaped tube wall members 33A and 34A, and the passage formed at the time of completion becomes a rectangular cross section by reducing the width of the convex portion and the height of the convex portion. . In (3), a wide and flat tube wall member 35A, 36A and a narrow, flat tube wall member 37A, 38A are manufactured, and the width of the tube wall members 37A, 38A is made smaller and thinner. Thus, the passage formed at the time of completion becomes a rectangular cross section. The laser beam from the light emitting portion 41 is incident on, for example, the tube wall 305 on the long side among the four tube walls 305, 306, 307, and 308 that form the passage of the narrow tube 3A, and the tube wall 306 on the opposite side. The narrow tube 3A is arranged so that the traveling direction of the laser beam and each surface of the long side tube walls 305 and 306 are orthogonal to each other.
[0082]
The following effects are produced by adopting such a configuration of the thin tube 3A. FIGS. 13 and 14 show a state in which a belt-shaped laser beam passes through a narrow tube 3 having a square passage cross section, and in the drawing, X1 is a center line of a passage portion of the narrow tube 3. FIG. Originally, the laser beam L is perpendicularly incident on the incident side tube wall 301 as shown in FIG. 13 and passes through the opposite exit side tube wall 302. However, as shown in FIG. 14, when the surface formed by the laser beam L is inclined with respect to the center line X1, a part of the laser beam L (the upper half of the laser beam L in the example) is inside the narrow tube 3. Passing through the pipe walls 303 and 304 (303 in the illustrated example) without passing through the liquid level, the liquid level cannot be detected at this position.
[0083]
Therefore, alignment between the narrow tube 3 and the light emitting unit 41 is important. However, if the passage section of the narrow tube 3 is narrowed to increase the detection sensitivity of the leakage amount, the width of the narrow tube 3 in which the laser beam L is allowed to be allowed. The surface of the surface of the laser beam L formed by the laser beam L so that the deviation is small and the laser beam L irradiated in a strip shape passes from one end of the laser beam L to the other end is opposed to the incident side tube wall 301 and the exit side tube wall 302. The inclination angle with respect to the center line X1 must be made smaller. If the passage cross section of the thin tube 3 is narrowed, the amount of rise in the liquid level relative to the amount of leakage becomes relatively large, and the length of the laser beam L of the light emitting unit 41 in the liquid surface displacement direction needs to be relatively widened. The alignment of 41 and the thin tube 3 becomes difficult.
[0084]
On the other hand, in the thin tube 3A, since the shape of the passage section is a rectangle having a wide width direction, the light emitting portion 41 is inclined with respect to the center line X2 of the passage portion of the thin tube 3A as shown in FIG. Even if the other end and the other end are deviated in the width direction of the passage cross section, the permissible deviation can be made large, and the alignment of the light emitting portion 41 and the thin tube 3A becomes easy.
[0085]
In order to increase the width of the entrance-side tube wall and the exit-side tube wall as much as possible with the same passage cross-sectional area, the shape of the passage cross-section is preferably rectangular as shown in FIG. 12, but (1), ( As shown in 2), (3), and (4), the short side surfaces (upper and lower surfaces in the figure) that are non-laser beam transmitting surfaces of the passages of the narrow tubes 3C, 3D, 3E, and 3F bulge out. It is good also as a shape. In the figure, L1 is the traveling path of the laser beam. Further, the external shape of the thin tube is not necessarily rectangular, and it may have a shape with a reduced corner like the thin tubes 3D and 3F in the illustrated example. It is sufficient that at least the surfaces of the incident side tube wall and the emission side tube wall through which the laser beam passes are parallel to each other.
[0086]
(Second Embodiment)
17 and 18 show a liquid tightness measuring apparatus according to the second embodiment of the present invention. In the configuration of the first embodiment, the downstream portion of the temperature control pipe formed on the narrow tube and the base is a different configuration. In the figure, the portion that operates substantially the same as the first embodiment The same number is attached | subjected and it demonstrates centering on difference with 1st Embodiment.
[0087]
As shown in FIG. 18, the thin tube 3G has a rectangular cross-sectional shape, and is composed of a U-shaped tube wall member and a rectangular tube wall member as shown in FIG. The laser beam is incident from the tube wall on the long side of the passage and passes through the tube wall on the opposite side through the passage.
[0088]
In the thin tube 3G, vertical holes 515a and 515b are formed in two portions in parallel with the passage on the tube wall portion that is not the traveling path of the laser beam.
[0089]
The holding member 96 that receives the upper end portion of the thin tube 3G communicates the three-way valve 67 and the thin tube 3G through the straight passage 961, and communicates the vertical holes 515a and 515b of the thin tube 3G through the U-shaped passage 514. In the figure, both vertical holes 515a and 515b of the thin tube 3G and the U-shaped passage 514 of the holding member 96 are developed 90 degrees.
[0090]
The downstream portion 513A of the temperature control pipe 51A formed inside the base 9 is divided at the bottom of the recess 95 that receives the lower end of the thin tube 3G, and one of the divided ends is one vertical hole of the thin tube 3G. It communicates with 515a, and the other of the divided ends communicates with the other vertical hole 515b of the thin tube 3G. Thus, the heat medium sent out from the heat medium pump 53 is returned to the heat medium tank 52 through the inside of the base 9 and the inside of the tube wall of the thin tube 3G. With this circulating heat medium, the temperature of the entire base 9 is adjusted, and the temperature of the tube wall of the thin tube 3G is adjusted.
[0091]
In the present embodiment, not only the fuel that is the test solution and the base 9, but also the tube wall of the thin tube 3G can be maintained at a constant temperature, so that the thermal expansion of the thin tube 3G can be prevented, and the leakage amount can be measured. Accuracy can be improved.
[0092]
As described above, according to the liquid-tightness measuring apparatus of the present invention, high measurement accuracy can be obtained, and it can be applied to inspection of a high-performance fuel injection valve or the like. In addition, as described above, since the speed of measurement is increased while maintaining high measurement accuracy, the throughput can be increased.
[0093]
In each of the above embodiments, the heat exchanging means for exchanging heat with the fuel in the fuel tank 71, the fuel pipe 72, and the sampling passage 2 is constituted by the single temperature control pipe 51 through which the heat medium circulates. Any configuration may be used as long as heat is exchanged in common with the fuel such as the fuel tank 71.
[0094]
Further, the filling test solution pressurizing means for pressurizing the inside of the fuel tank 71 and the bubble detecting pressurizing means for pressurizing the inside of the narrow tube 3 are not limited to those constituted by the gas cylinder 60, for example, in the gas pipe 61. The air may be pressurized by pumping.
[0095]
Further, the sampling passage 2 may have a shape that descends straight from the sampling port and extends to the bent portion, changes its direction obliquely upward to extend directly below the narrow tube 3, and rises straight from the position immediately below to the other end. Alternatively, the collection passage may have a V shape extending obliquely upward from a bent portion in the middle toward a position directly below the collection port and the thin tube.
[0096]
Further, when the liquid level of the thin tube 3 is initialized, the fuel is drawn back from the thin tube 3 through the collection passage 2 and overflows from the discharge port 93 via the waste liquid tray 91, but another discharge passage leading to the lower end of the thin tube 3. The discharge port may be configured to open to the height of the initial liquid level, and the fuel may be discharged through the discharge passage while the collection port is closed. Note that the discharge port is closed or the discharge passage is shut off from the sampling passage except at the time of liquid level initialization.
[0097]
Depending on the required measurement accuracy, some configurations of the present invention disclosed in the present embodiment may be omitted to simplify the configuration of the apparatus. In other words, if the priority for improving the accuracy of liquid level detection is low, the thin tube can be constituted by a drawn round tube.
[0098]
In addition, if the priority for preventing the expansion and contraction of the fuel volume due to temperature fluctuation is low, pressurization of the fuel in the test object may be performed by a pump that delivers the fuel. Further, the fuel temperature may be adjusted by using separate temperature control pipes for the fuel supplied to the test object and the fuel introduced into the narrow pipe. Alternatively, the temperature adjusting means itself may be omitted.
[0099]
Further, if there is not much risk of air bubbles being mixed and the priority of air bubble mixing prevention is low in order to improve the measurement accuracy, the middle part of the sampling passage may be formed in the horizontal direction. In addition, if the mixing amount is small even if it is mixed, there is no need to judge the bubble mixing, omitting the regulator and three-way valve for applying the gas pressure from the gas cylinder to the narrow tube, and always opening the upper part of the narrow tube to the atmosphere The apparatus configuration may be simplified.
[0100]
Further, these means may be used as long as the priority order of the accuracy of the initial liquid level in the narrow tube is low and the initial setting of the fuel in the narrow tube can be performed manually or by feedback control of the fuel in the narrow tube.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a liquid tightness measuring apparatus showing an embodiment of the present invention.
FIGS. 2 (1), (2), and (3) are cross-sectional views for explaining a manufacturing process of a first thin tube of the liquid tightness measuring apparatus.
FIG. 3 is a flowchart for explaining the operation of the liquid-tightness measuring apparatus.
FIG. 4 is an overall configuration diagram in a first operating state for explaining the operation of the liquid-tightness measuring apparatus.
FIG. 5 is an overall configuration diagram in a second operating state for explaining the operation of the liquid-tightness measuring apparatus.
FIG. 6 is an overall configuration diagram in a third operating state for explaining the operation of the liquid-tightness measuring apparatus.
FIG. 7 is an overall configuration diagram in a fourth operating state for explaining the operation of the liquid-tightness measuring apparatus.
FIG. 8 is an overall configuration diagram in a fifth operating state illustrating the operation of the liquid-tightness measuring apparatus.
FIG. 9 is an overall configuration diagram in a fifth operating state illustrating the operation of the liquid tightness measuring apparatus.
FIG. 10 is a first graph for explaining the operation of the liquid tightness measuring apparatus.
FIG. 11 is a second graph for explaining the operation of the liquid tightness measuring apparatus.
FIGS. 12 (1), (2), and (3) are cross-sectional views illustrating the manufacturing process of the second thin tube of the liquid-tightness measuring device.
FIG. 13 is a cross-sectional view of a thin tube section for explaining the operation of the liquid tightness measuring device using the first thin tube compared with the liquid tightness measuring device using the second thin tube, (2) ) Is a cross-sectional view taken along line A1-A1 in (1), and (3) is a cross-sectional view taken along line B1-B1 in (2).
FIG. 14 is a cross-sectional view of a thin tube portion having different operating states for explaining the operation of the liquid tightness measuring device using the first thin tube compared with the liquid tightness measuring device using the second thin tube. Yes, (2) is a sectional view taken along line A1-A1 in (1), and (3) is a sectional view taken along line B1-B1 in (2).
15A is a cross-sectional view of a thin tube portion for explaining the operation of the liquid-tightness measuring apparatus using the second thin tube, and FIG. 15B is a cross-sectional view taken along line A2-A2 in FIG. (3) is a sectional view taken along line B2-B2 in (2).
FIGS. 16 (1), (2), (3), and (4) are diagrams showing modified examples of thin tubes that can be used in the liquid-tight measuring device.
FIG. 17 is an overall configuration diagram of a liquid tightness measuring apparatus showing another embodiment of the present invention.
18 is a cross-sectional view of a thin tube of the liquid-tightness measuring device, and (2) is a cross-sectional view taken along the line CC in (1).
[Explanation of symbols]
1 Test object
2 sampling passage
201 Sampling port (one end)
202 other end
203 Bending part
3, 3A, 3B, 3C, 3D, 3E, 3F, 3G tubule
31, 32, 33, 34, 35, 36, 37, 38, 31A, 32A, 33A, 34A, 35A, 36A, 37A, 38A
301,305 Incident side tube wall (tube wall)
302,306 Output side tube wall (tube wall)
303, 304, 307, 308 pipe wall
3c, 3d, 3e, 3f Inner surface
4 Laser displacement sensor (liquid level detection means)
41 Light emitting part
42 Light receiver
5 Temperature adjustment part (temperature adjustment means)
51 Temperature control piping (heat medium flow path)
515a, 515b Vertical hole
54 Heating and cooling means
6a Filling test solution pressurizing means
6b Pressure detecting means for detecting bubbles
60 Gas cylinder
62,65 Regulator
91 Waste liquid tray (liquid reservoir)
93 outlet

Claims

Filling test liquid pressurizing means for pressurizing the test liquid filled in the test object, a sampling passage for collecting the test liquid leaking from the liquid-tight part of the test object at one end, and other than the sampling path A transparent thin tube connected to the end and into which the collected test solution is introduced, a light emitting unit that emits light across the thin tube, and a light receiving unit that is disposed on the opposite side of the light emitting unit across the thin tube and detects the light A liquid level detecting means for detecting the liquid level of the test liquid in the narrow tube based on the detection light, and measuring the amount of the test liquid leaked from the liquid tight part due to the change in the liquid level In the liquid-tightness measuring apparatus, a heat exchange means common to these test liquids for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the narrow tube is provided. the provided Rutotomoni, the heat exchanger hand temperature adjustment means for controlling the temperature And forming a vertical hole in the tube wall inside the capillary, fluid-tight measuring apparatus being characterized in that a configuration that allowed to flow through the heat medium to capillary walls and heat exchanger vertical hole.

Filling test liquid pressurizing means for pressurizing the test liquid filled in the test object, a sampling passage for collecting the test liquid leaking from the liquid-tight part of the test object at one end, and other than the sampling path A transparent thin tube connected to the end and into which the collected test solution is introduced, a light emitting unit that emits light across the thin tube, and a light receiving unit that is disposed on the opposite side of the light emitting unit across the thin tube and detects the light A liquid level detecting means for detecting the liquid level of the test liquid in the narrow tube based on the detection light, and measuring the amount of the test liquid leaked from the liquid tight part due to the change in the liquid level In the liquid-tightness measuring apparatus, a heat exchange means common to these test liquids for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the narrow tube is provided. And a temperature adjusting means for controlling the temperature of the sampling passage. , Liquid-tight measuring device being characterized in that a shape leading to the one end and the other end extends upward from the bent portion as a lowest position.

Filling test liquid pressurizing means for pressurizing the test liquid filled in the test object, a sampling passage for collecting the test liquid leaking from the liquid-tight part of the test object at one end, and other than the sampling path A transparent thin tube connected to the end and into which the collected test solution is introduced, a light emitting unit that emits light across the thin tube, and a light receiving unit that is disposed on the opposite side of the light emitting unit across the thin tube and detects the light A liquid level detecting means for detecting the liquid level of the test liquid in the narrow tube based on the detection light, and measuring the amount of the test liquid leaked from the liquid tight part due to the change in the liquid level In the liquid-tightness measuring apparatus, a heat exchange means common to these test liquids for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the narrow tube is provided. Temperature adjustment means to control the temperature of the It is equipped with a pressure detection means for detecting bubbles that pressurizes the test solution in the sampling passage and the narrow tube, and the amount of bubbles mixed in the test solution is detected based on the amount of displacement of the test solution level during pressurization. A liquid-tightness measuring device characterized by that .

Filling test liquid pressurizing means for pressurizing the test liquid filled in the test object, a sampling passage for collecting the test liquid leaking from the liquid-tight part of the test object at one end, and other than the sampling path A transparent thin tube connected to the end and into which the collected test solution is introduced, a light emitting unit that emits light across the thin tube, and a light receiving unit that is disposed on the opposite side of the light emitting unit across the thin tube and detects the light A liquid level detecting means for detecting the liquid level of the test liquid in the narrow tube based on the detection light, and measuring the amount of the test liquid leaked from the liquid tight part due to the change in the liquid level In the liquid-tightness measuring apparatus, a heat exchange means common to these test liquids for performing heat exchange with the test liquid supplied to the test object and heat exchange with the test liquid introduced into the narrow tube is provided. Temperature control means to control the temperature of the Stand up from the other end of the sampling passage and lead to the lower end of the narrow tube. After measuring the leakage test solution, provide a discharge passage to discharge the test solution in the narrow tube to the outside of the narrow tube. A liquid- tight measuring device having an opening at a predetermined initial liquid level which is a reference for liquid measurement.

5. The liquid tightness measuring apparatus according to claim 4, wherein a sampling port of the sampling passage is provided below the initial liquid level of the thin tube, and the liquid tight part of the test object is removed from the thin tube when removed from the sampling port. A liquid-tight measurement is provided in which a liquid reservoir for storing the test liquid that flows back and flows is provided, the liquid reservoir overflows at the height of the initial liquid level, and the discharge passage is composed of a sampling passage and a liquid reservoir. apparatus.