JP3933071B2

JP3933071B2 - Inspection device for fluid passage parts

Info

Publication number: JP3933071B2
Application number: JP2003079019A
Authority: JP
Inventors: 博美酒井
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2003-03-20
Filing date: 2003-03-20
Publication date: 2007-06-20
Anticipated expiration: 2023-03-20
Also published as: JP2004286597A

Description

【０００１】
【発明の属する技術分野】
本発明は、流体通路部品の検査装置に関し、特に流体通路部品の液密状態に係る検査する検査装置に関する。
【０００２】
【従来の技術】
流体通路部品、例えば自動車用内燃機関に用いられるインジェクタ、あるいはプレッシャレギュレータの製品検査項目として、弁部の油密検査がある。この弁部の油密検査では、例えばインジェクタの弁部を構成するバルブとノズルニードルが閉弁状態にあるとき、バルブとノズルニードルで形成されるシール部からにじみ出る加圧燃料油の漏れ状態を検査する。この種の油密検査を行なう検査装置としては、燃料通路部品としてのインジェクタに、燃料油相当のテスト油を、一定圧力で供給経路を通じて加圧供給した後、その供給経路側を遮断弁等の開閉弁で遮断し一定時間経過後の圧力降下量でもって、漏れ状態を判定するものがある。
【０００３】
なお、遮断弁とインジェクタとの間あるインジェクタ側供給経路には、圧力センサが設けられている。燃料通路部品と遮断弁とインジェクタ側供給経路は、油密に係る圧力降下量を計測する計測回路を構成している。
【０００４】
【発明が解決しようとする課題】
従来技術の検査装置では、遮断弁の閉弁動作によってテスト油の供給経路を遮断する際、遮断弁の弁部材の弁座への移動によって計測回路を構成するインジェクタ側供給経路内にウォータハンマが発生し、圧力変動が生じるという問題があった。この圧力変動が大きい場合あるいは圧力降下量の判定を行なう所定経過時間までにその圧力変動が減衰しない場合には、油密検査精度が低下するおそれがある。
【０００５】
本発明は、このような事情を考慮してなされたものであり、その目的は、液密状態を流体通路部品に充填した流体の圧力降下量で評価するものにおいて、液密検査精度の向上が図れる流体通路部品の検査装置を提供することにある。
【０００６】
また、別の目的は、液密状態を流体通路部品に充填した流体の圧力降下量で評価するものにおいて、液密検査精度の向上が図れるとともに、液密検査時間の短縮が可能な流体通路部品の検査装置を提供することにある。
【０００７】
【課題を解決するための手段】
本発明の請求項１によると、流体通路部品の液密状態を、流体通路部品に供給した加圧液体の圧力低下量で評価する流体通路部品の検査装置であって、流体を供給する加圧流体供給源と、加圧流体供給源で加圧された流体を、液密検査対象としての流体通路部品に導くことが可能な流体供給経路と、流体供給経路のうち、加圧流体供給源と流体通路部品との間に設けられ、流体の流通および遮断を行なう第１の開閉弁と、流体供給経路のうち、第１の開閉弁と流体通路部品との間に形成された流体供給経路部から分岐して接続される第２の開閉弁と、流体供給経路部内の圧力を検出する検出手段とを備え、第２の開閉弁は、第１の開閉弁の流通および遮断動作により変化する容積分と略同じ容積を有し、第１の開閉弁の流通および遮断動作に対して遮断、流通動作する。
【０００８】
まず、流体通路部品に流体を供給する流体供給経路のうち、第１の開閉弁と流体通路部品との間にある流体供給経路部は、第１の開閉弁の遮断動作によって加圧流体供給源からの流体供給が停止される。
【０００９】
さらに、流体供給経路部には、流体供給経路部から分岐して接続される第２の開閉弁を備え、第１の開閉弁の流通、遮断動作により変化する容積分と略同じ容積を有し、第１の開閉弁の流通、遮断動作に対して、遮断、流通動作するため、例えば第１の開閉弁の遮断動作によって減少した容積を、流体供給経路部は、第２の開閉弁の流通動作によって増加した容積で補うことができる。
【００１０】
これにより、流体を供給する側の開閉弁つまり第１の開閉弁の遮断動作によって流体供給経路部が閉回路になった直後に発生するウォータハンマを防止することが可能である。したがって、第１の開閉弁の遮断動作によって閉回路となった流体供給経路部つまり圧力降下量を評価するための液密計測回路の圧力変動を防止することが可能である。
【００１１】
本発明の請求項２によると、第１の開閉弁および第２の開閉弁は、それぞれ弁座を有するバルブボディと、先端部が弁座に当接および離間可能な弁部材とを備え、流通、遮断動作により変化する容積は、先端部が弁座に当接および離間するに従い、先端部が移動する体積から構成されている。
【００１２】
これにより、第１の開閉弁は、少なくとも第１の開閉弁の流通、遮断動作において弁座に当接、離間するに従い、先端部が移動する体積分を補うように、その移動体積分の容積を確保することができる。
【００１３】
例えば第１の開閉弁の遮断動作において弁部材が弁座に近づくに従って弁部材の先端部により液体が圧縮されることを、第２の開閉弁の流通動作による弁部材の弁座から離れるに従って、液体を減圧することで相殺する。その結果、第１の開閉弁の遮断動作に伴う流体供給経路部の圧力変動を防止する。
【００１４】
本発明の請求項３によると、第１の開閉弁および第２の開閉弁は、それぞれ弁座を有するバルブボディと、先端部が弁座に当接および離間可能な弁部材とを備え、流通、遮断動作により変化する容積は、先端部が弁座に当接した状態でのバルブボディの内周と、弁部材の外周の間に区画される内部流体空間から構成されている。
【００１５】
これにより、第１の開閉弁は、少なくとも第１の開閉弁の流通、遮断動作において第１の開閉弁の内部に収容される流体のうち、第１の開閉弁が遮断されることで、流体供給経路部から分離されるバルブボディの内周と弁部材の外周の間に区画される内部流体空間分を、第２の開閉弁の流通動作によって流体供給経路部と連通する第２の開閉弁の内部流体空間で補うことができる。
【００１６】
本発明の請求項４によると、第２の開閉弁と第１の開閉弁は同じものであって、二つの第１の開閉弁を用いることができる。
【００１７】
本発明の請求項５によると、流体供給経路のうち、加圧流体供給源と第１の開閉弁との間には、流量調整弁を配置することが可能である。
【００１８】
例えば流体通路部品として、内燃機関へ供給する燃料の圧力を制御する燃料圧力制御弁に適用する場合、第１の開閉弁の流通状態にて所定の一定流量における作動圧力を測定することと、第１の開閉弁の流通動作から遮断動作に切換えて液密検査にけるウォータハンマによる圧力変動を防止することが両立できる。
【００１９】
本発明の請求項６によると、第１の開閉弁および第２の開閉弁における流体の流通、遮断動作を行なう駆動源は、工場エアを用いることができ、安価な油密検査装置を提供することができる。
【００２０】
本発明の請求項７によると、流体通路部品として、燃料の供給により駆動される内燃機関等の駆動源に搭載される燃料供給部品に好適に適用することができる。
【００２１】
【発明の実施の形態】
以下、本発明の流体通路部品の検査装置を、具体化した実施形態を図面に従って説明する。図１は、本実施形態の流体通路部品の検査装置の概略構成を示す構成図である。図２は、図１中の第１の開閉弁、および第２の開閉弁の弁部構造を示す模式的断面図である。図３は、実施形態に係る流体通路部品の検査過程における圧力変化特性を表す模式的グラフである。図４は、図１中の第１の開閉弁および第２の開閉弁の作動状態を示す図である。なお、図５は、本実施形態に係る液密検査過程における圧力変化特性を、従来技術における圧力変化特性と比較して示すグラフである。
【００２２】
図１に示すように、流体通路部品の検査装置１は、検査対象としての流体通路部品９の液密状態を検査する。この検査装置１では、流体通路部品９に供給した加圧液体の圧力低下量を測定し、その測定した圧力降下量から液密状態を判定する。
【００２３】
流体通路部品９としては、流体を貯留するために溶接等の接合により形成した容器、流体の流量を調整する流量調整装置、あるいは流体を噴射するための流体噴射装置であっても、液密状態が製品または部品性能項目の一つとして液密状態の検査を行なうものであればいずれの部品、製品、あるいは装置であってもよい。例えば燃料の供給により駆動される内燃機関等の駆動源に搭載される燃料噴射弁、あるいは燃料圧力制御弁等の燃料供給部品であってもよい。なお、以下本実施形で説明する流体通路部品９は、内燃機関へ燃料を供給するため、燃料ポンプ等によって燃料タンクから汲み上げ燃料を、所定の燃料圧力に調圧する流体圧力制御弁（以下、プレッシャレギュレータと呼ぶ）とする。
【００２４】
プレッシャレギュレータ９は、図示しない弁部を構成する弁体（図示せず）と弁座（図示せず）のうち、弁座が、図示しないダイヤフラムとともにケースに固定されている。この弁座およびダイヤフラムによって、そのケース内が、圧力調整側燃料チャンバー（図示せず）と燃料戻し側燃料チャンバー（図示せず）に仕切られている。弁部が開弁すると、圧力調整側から燃料戻し側（低圧側）の燃料チャンバーに燃料が流入する。その結果、この種のプレッシャレギュレータ９は、圧力調整側の燃料が所定流量において、弁部の開弁圧に従いその圧力調整側の燃料を所定の燃料圧力に調圧する。
【００２５】
図１に示すように、検査装置１は、流体としてのテスト油を供給する加圧流体供給源（以下、送油ポンプと呼ぶ）２と、流体の流通、遮断を行なう第１の開閉弁３と、流体の流通、遮断を行なう第２の開閉弁４と、送油ポンプ２で加圧されたテスト油をレギュレータ９に導くことが可能な流体供給経路５と、加圧されたテスト油の圧力を検出する圧力検出手段としての圧力センサ６とを含んで構成されている。なお、テスト油は、製品としてのプレッシャレギュレータ９が調圧する流体すなわち燃料相当の油性状を有するものであればいずれの油、液体であってもよい。燃料相当の油性状とは、例えば流量測定、油密状態の検査に必要な動粘度等が燃料と同じ性状を有するものであれば、燃料に比べて可燃性が低い液体を用いることが好ましい。
【００２６】
送油ポンプ２は、図１に示すように、テスト油が貯留されているタンク７からフィルタ８を介してテスト油を汲み上げ、流体供給経路５へ吐出する。なお、流体供給経路５には、経路途中に背圧調整弁（以下、リリーフ弁）１１を備えており、送油ポンプ２から吐出されたテスト油を所定圧力Ｐ１（図３参照）に設定する。リリーフ弁１１によって調圧されたテスト油のうち余剰のテスト油は、リリーフ弁１１を経てテスト油の低圧側のタンク７に戻される。
【００２７】
流体供給経路５は、周知の配管で構成さている。なお、流体供給経路５の材料としては銅材を用い、配管と、配管あるいは装置等とを繋ぐ配管の継手部は、スリーブ式の締結構造を有する。なお、この流体供給経路５のうち、テスト油に接する部分については電気的な導通が確保できる構造とし、電気的に接地または同電位に保持されていることが好ましい。
【００２８】
第１の開閉弁３は、図１に示すように、流体供給経路５のうち、送油ポンプ２とプレッシャレギュレータ９との間に設けられ、送油ポンプ２で加圧され、プレッシャレギュレータ９へ導かれるテスト油の流通、遮断を行なう。
【００２９】
なお、検査対象である流体通路部品（本実施例では、プレッシャレギュレータ）９の検査項目の一つとして、テスト油の流量を所定流量に設定したときの作動圧を評価する場合には、第１の開閉弁３と送油ポンプ２の間の流体供給経路５の途中に、流量調整装置２１を設けてもよい。この流量調整装置２１は、テスト油の流量調整を行なう流量調整弁部２１ｂと、テスト油の流通、遮断を行なう切換弁部２１ａとからなる。この場合、以下で説明する液密状態に係るプレッシャレギュレータ９の検査する検査過程では、切換弁部２１ａは常に流通状態にある。流量調整装置２１は流量調整弁部２１ｂだけから構成されるものであってもよい。
【００３０】
圧力センサ６は、図１に示すように、流体供給経路５のうち、第１の開閉弁３とプレッシャレギュレータ９との間に形成されている流体供給経路部５ａに設けられ、流体供給経路部５ａ内のテスト油の圧力を検出する。
【００３１】
第２の開閉弁４は、図１に示すように、流体供給経路部５ａから分岐して接続されている。
【００３２】
プレッシャレギュレータ９の燃料導入側つまり圧力調整側には、流体供給経路部５ａが接続され、一方、プレッシャレギュレータ９の燃料戻し側（低圧側）は、漏れ状態を検査するときのにじんだ漏れテスト油、あるいは作動圧を評価するときの余剰のテスト油を再利用できるように、タンク７またはタンク７上部のワーク取付台（図示せず）に取付けられる。
【００３３】
なお、第１の開閉弁３、流体供給経路部５ａ、第２の開閉弁４、および圧力センサ６は、プレッシャレギュレータ９の液密状態すなわち漏れ状態係る圧力降下量を計測する計測回路を構成している。
【００３４】
ここで、第１の開閉弁３および第２の開閉弁４の構造、および第１の開閉弁３と第２の開閉弁４の流通、遮断動作の関係について、図２から図４に従って説明する。なお、図２（ａ）および図２（ｃ）はテスト油を流通させる開弁状態、図２（ｂ）および図２（ｄ）はテスト油を遮断する閉弁状態を示し、図２（ａ）および図２（ｂ）は第１の開閉弁３、図２（ｃ）および図２（ｄ）は第２の開閉弁４のそれぞれの構造を示す。
【００３５】
第１の開閉弁３および第２の開閉弁４は、図２（ａ）、図２（ｃ）に示すように、それぞれ、弁座３ａｓ、４ａｓを有するバルブボディ３ａ、４ａと、弁部材３ｂ、４ｂとを含んで構成されている。弁部材３ｂ、４ｂはバルブボディ３ａ、４ａに軸方向移動可能に収容されている。弁部材３ｂ、４ｂの図２（ａ）、図２（ｃ）中軸方向下方の先端部３ｂｓ、４ｂｓは、弁座３ａｓ、４ａｓに当接、離間可能に配置されている。バルブボディ３ａ、４ａの先端には弁座３ａｓ、４ａｓに開口する開口部３ａｏ、４ａｏが設けられている。
【００３６】
図２（ｂ）の第１の開閉弁３の閉弁状態において、開口部（以下、先端側開口部と呼ぶ）３ａｏは、流体供給経路部５ａが接続されている。一方、弁部材３ｂの先端部３ｂｓが弁座３ａｓに当接した状態で弁部材３ｂの外周とバルブボディ３ａの内周の間に区画される内部流体空間（以下、テスト油閉塞空間と呼ぶ）Ｒ３に連通するように、流体供給経路部５ａの反対に位置するの流体供給経路５側がバルブボディ３ａの外周に形成された開口部（以下、外周側開口部と呼ぶ）（図示せず）に接続している。そして、第１の開閉弁３が閉弁状態では、テスト油閉塞空間内にあるテスト油と、流体供給経路部５ａ内にあるテスト油とは分離状態にある。一方、第１の開閉弁３が開弁状態では、テスト油閉塞空間内にあるテスト油と、流体供給経路部５ａ内にあるテスト油とが連通する。従って、送油ポンプ２により加圧されたテスト油の流通供給経路部５ａへの流れを、第１の開閉弁３の開弁、閉弁動作によってそれぞれ流通、遮断する。
【００３７】
図２（ｃ）の第２の開閉弁４の閉弁状態において、先端側開口部４ａｏは、同様に、流体供給経路部５ａが接続されている。一方、弁部材３ｂの先端部３ｂｓが弁座３ａｓに当接した状態で弁部材４ｂの外周とバルブボディ４ａの内周の間に区画されるテスト油閉塞空間Ｒ４に連通するための外周側開口部が形成されている場合、外周側開口部が形成されていない場合のいずれであってもよい。なお、外周側開口部が形成されている場合には、図１に示すように、外周側開口部は盲栓等により閉塞される構成とする。これにより、第２の開閉弁４の外周側開口部から、テスト油閉塞空間Ｒ４内のテスト油が、外部に流出しないように構成される。従って、流通供給経路部５ａ内にあるテスト油をテスト油閉塞空間Ｒ４へ導く流れを、第２の開閉弁４の開弁、閉弁動作によってそれぞれ流通、遮断する。
【００３８】
さらに、本実施形態では、図２に示すように、第１の開閉弁３と第２の開閉弁４は同じ仕様の開閉弁が用いられ、二つの第１の開閉弁３を用いていることが好ましい。これにより、テスト油閉塞空間Ｒ３およびテスト油閉塞空間Ｒ４は同じ容積となる。さらに、閉弁動作中に、弁部材３ｂ、４ｂの先端部３ｂｓ、４ｂｓが弁座３ａｓ、４ａｓに当接するまでに移動する移動体積Ｖ３、Ｖ４も同じ体積となる。
【００３９】
なお、移動体積Ｖ３、Ｖ４とは、先端部３ｂｓ、４ｂｓの表面積と、先端部３ｂｓ、４ｂｓが当接、離間するに従い移動する移動距離の積である。
【００４０】
さらになお、第１の開閉弁３および第２の開閉弁４の流通、遮断動作を行なう駆動源としては、図２に示すように、軸方向に移動する弁部材３ｂ、４ｂを工場エア等の圧力源を用いる。なお、ソレノイド等の電磁力発生装置を用いてもよい。
【００４１】
次に、第１の開閉弁３と第２の開閉弁４の流通、遮断動作状態の関係は、図３に示すプレッシャレギュレータ９の検査過程における流通供給経路部５ａつまり計測回路内でのテスト油の圧力特性において、図４に示す以下の関係にある。
【００４２】
（１）まず、被検査体のワークとしてのプレッシャレギュレータ９を、燃料タンク７のワーク取付台に取付ける。そして、流体供給経路５をプレッシャレギュレータ９に接続し、計測回路を形成する。この状態では、第１の開閉弁３は遮断状態にある。流通供給経路部５ａ内のテスト油の圧力は上がることはない。この状態を、ワークセット状態Ａ（図３参照）と呼ぶ。なお、このとき、送油ポンプ５は、テスト油の送油を停止する停止状態であっても、テスト油を送油する連続運転状態にあってもいずれでもよい。
【００４３】
第１の開閉弁３、第２の開閉弁４の動作状態としては、図４中のワークセット状態Ａに示すように、流体遮断状態（閉弁動作）、流体流通状態（開弁動作）に設定されている。
【００４４】
（２）流通供給経路部５ａ内に、送油ポンプ５により加圧されたテスト油を導入する。すると、流通供給経路部５ａ内のテスト油の圧力は昇圧され、図３に示すように、所定圧力Ｐ１となる。この状態では、流通供給経路部５ａを通じて所定圧力Ｐ１のテスト油が送油され続ける。この状態を、テスト油送油状態Ｂ（図３参照）と呼ぶ。
【００４５】
第１の開閉弁３、第２の開閉弁４の動作状態としては、図４中のテスト油送油状態Ｂに示すように、流体流通状態（開弁動作）、流体遮断状態（閉弁動作）に設定されている。
【００４６】
（３）流通供給経路部５ａ内のテスト油の圧力が安定した所定圧力Ｐ１になったことを圧力センサ６で検出するか、もしくはテスト油送油状態Ｂでの期間が所定経過時間を経過すると、流通供給経路部５ａを閉塞させ、つまり計測回路を閉回路とする。この状態を、液密状態に係る検査状態Ｃと呼ぶ。第１の開閉弁３、第２の開閉弁４の動作状態としては、図４中の液密状態に係る検査状態Ｃに示すように、流体遮断状態（閉弁動作）、流体流通状態（開弁動作）に設定されている。
【００４７】
この状態では、流通供給経路部５ａ内に所定圧力Ｐ１のテスト油の充填が完了し、送油ポンプ５により加圧されたテスト油のプレッシャレギュレータ９への供給が停止される。これにより、プレッシャレギュレータ９の作動圧を形成する弁部の弁体と弁座のシール状態の良い、悪いのレベルによって、弁体と弁座のシール部（図示せず）からテスト油の低圧側としてのタンク７へにじみでる漏れ量が少なく、多くなる。そして、その漏れ量に応じて流通供給経路部５ａつまり計測回路内に充填されているテスト油の圧力が、所定圧力Ｐ１から徐々に低下する。その結果、図３に示すように、この計測回路内における所定時間Ｔ経過後の圧力降下量ΔＰを計測することで、プレッシャレギュレータ９の液密状態が判定される。
【００４８】
この様に、第２の開閉弁４は、第１の開閉弁３の流通、遮断動作に対して、遮断、流通動作する作動状態の関係にあるように設定されている。
【００４９】
なお、第１の開閉弁３、第２の開閉弁４の作動状態において、第１の開閉弁３を開弁動作から閉弁動作に切換える際、略同タイミングで第２の開閉弁４を閉弁動作から開弁動作に切換えることが好ましい。つまり第１の開閉弁３を遮断動作に切換える際、略同タイミングで第２の開閉弁４を流通動作に切換えることが好ましい。
【００５０】
上述の構成を有する検査装置１において、プレッシャレギュレータ９の液密状態を、流通供給経路部５ａつまり計測回路に設けられた圧力センサ６で検出したテスト油の圧力降下量ΔＰで判定する方法の検査精度を、実験により確認した（図５参照）。図５において、実線による圧力変化特性は本実施形態の検査装置１を用いた場合を示し、破線による圧力変化特性は従来の検査装置１を用いた場合のものを示す。図５に示すように、本実施形態の検査装置１を用いた場合、従来の検査装置を用いたものに比べて、液密状態の検査状態Ａに切換え直後、すなわち第１の開閉弁３を流通動作から遮断動作に切換え直後に生じるウォータハンマ現象を防止することを確認した。
【００５１】
上述の本実施形態によれば、検査装置１は、流通供給経路部５ａへのテスト油の流通、遮断を行なう第１の開閉弁３と、この第１の開閉弁３とは別に、流通供給経路部５ａから分岐して接続する第２の開閉弁４とを備えている。しかも、これら第１の開閉弁３と第２の開閉弁４は同じ仕様の開閉弁であって、二つの第１の開閉弁３が用いられている。そして、第２の開閉弁４は、第１の開閉弁３の流通、遮断動作に対して、遮断、流通動作する作動状態の関係にあるように設定されている。これにより、計測回路を構成する第１の開閉弁３、流体供給経路部５ａ、および第２の開閉弁４内におけるテスト液を満たすための容積のうち、第１の開閉弁３の遮断動作によって減少する容積を、第２の開閉弁４の流通動作によって増加して補うことができる。しかも、第１の開閉弁３と第２の開閉弁４は二つの第１の開閉弁３で構成されるので、減少する容積と増加する容積は略同じである。その結果、第１の開閉弁３の遮断動作によって流体供給経路部５ａつまり計測回路を閉回路となる前後の容積変化を小さく、もしくはなくすことができるため、第１の開閉弁３を流通動作から遮断動作に切換え直後に生じるウォータハンマ現象を防止することができる。したがって、第１の開閉弁３の遮断動作によって閉回路となった流体供給経路部５ａつまり圧力降下量ΔＰを計測するための計測回路におけるウォータハンマに起因した圧力変動を防止することが可能である。流体通路部品５の液密状態を検査する検査精度の向上が図れる。
【００５２】
さらになお、上述の本実施形態によれば、第１の開閉弁３を遮断動作に切換える際、略同タイミングで第２の開閉弁４を流通動作に切換えるので、第１の開閉弁３遮断動作による減少する容積と第２の開閉弁４を流通動作による増加する容積とで精度良く相殺することができる。したがって、第１の開閉弁３の遮断動作によって計測回路が閉回路となる前後で計測回路の容積が変化することを防止できるので、圧力降下量ΔＰを計測するための計測回路におけるウォータハンマに起因した圧力変動を防止することができる。
【００５３】
さらになお、上述の本実施形態によれば、第１の開閉弁３と送油ポンプ２の間の流体供給経路５の途中に、流量調整装置２１を設けることが可能である。第１の開閉弁３の遮断動作に起因して生じるウォータハンマを防止する方法として、第１の開閉弁３の流通流量を絞ることが考えられる。この方法では、流体供給経路５に流すことが可能なテスト油の流量を、ウォータハンマ防止のために絞った第１の開閉弁３の流通流量で制限さてしまう。これに対して本実施形態の検査装置１に用いる第１の開閉弁３および第２の開閉弁４では、これらの流通流量を絞ることを特徴としていないため、流体供給経路５に製品検査に必要な流量を流すことができる。これにより、本実施形態の検査装置１で、第１の開閉弁３の遮断状態にて流体通路部品９の液密状態に係る圧力降下量ΔＰの計測を、ウォータハンマによる圧力変動を防止するとともに、第１の開閉弁３の流通状態にて検査対象となる流体通路部品９の流量に係る機能を判定する検査を行なうことが可能である。検査装置１による検査対象である流体通路部品の適用例として説明したプレッシャレギュレータ９のように、検査項目の一つとして、テスト油の流量を所定流量に設定したときの作動圧を評価する場合に好適である。
【００５４】
さらになお、上述の本実施形態よれば、第１の開閉弁３および第２の開閉弁４の流通、遮断動作を行なう駆動源としては、軸方向に移動する弁部材３ｂ、４ｂを工場エア等の圧力源を用いることが可能である。第１の開閉弁３の遮断動作に起因して生じるウォータハンマを防止する方法として、電気的に弁部材３ｂが弁座３ａｓに移動する移動速度を可変にし、移動速度を弁座に近づくに従い遅くするものが考えられるが、高価である。また、第１の開閉弁３が閉弁するまでの時間が長くなるため、液密状態を検査するための総時間が長くなり、生産性が低下する。これに対して、本実施形態の検査装置１に用いる第１の開閉弁３および第２の開閉弁４では、これら弁部材３ｂ、４ｂの移動速度を弁座３ａｓ、３ｂｓに近づくに従い遅くする特徴としていないため、駆動源として、安価な工場エアを用いることができる。
【００５５】
なお、流体通路部品９が内燃機関等に燃料を供給する燃料通路部品の場合、その製造工程の性能検査工程では、検査装置を防爆構造にする必要がある。例えば開閉弁の駆動源が電機駆動装置の場合には火花が生じないように装置内に窒素ガス等の不活性ガスによりパージする必要があり、その装置つまり検査装置が高価となる。それに対して、本実施形態では第１の開閉弁３および第２の開閉弁４の流通、遮断動作を行なう駆動源として工場エアを用いるので安価である。したがって、本実施形態の検査装置１は、検査対象となる流体通路部品として、燃料の供給により駆動される内燃機関等の駆動源に搭載される燃料通路部品における油密状態等の機能検査に好適である。
【００５６】
以上説明した実施形態において、第１の開閉弁３と第２の開閉弁４は同じ仕様の開閉弁であって、二つの第１の開閉弁３が用いられているものとしたが、第１の開閉弁３と第２の開閉弁４は同じ仕様の開閉弁でなくとも、第１の開閉弁３の遮断動作によって減少する容積を、第２の開閉弁４の流通動作によって増加する容積で補うことが可能なものであればよい。例えば第１の開閉弁３および第２の開閉弁４の構造として、テスト油閉塞空間Ｒ３とテスト油閉塞空間Ｒ４が略同じ容積であればよい。これにより、第１の開閉弁３の遮断動作により流体供給経路部５ａ内のテスト油から分離されるテスト油閉塞空間Ｒ３内のテスト油の容積と、第２の開閉弁４の流通動作により流体供給経路部５ａ内のテスト油に連通するテスト油閉塞空間Ｒ４内のテスト油の容積が略同じとなる。その結果、第１の開閉弁３の遮断動作により流体供給経路部５ａ内の容積変化を殆どなく、またはなくすことができる。したがって、この様な構成であっても、圧力降下量ΔＰを計測するための計測回路におけるウォータハンマに起因した圧力変動を防止することが可能である。
【００５７】
なお、上記では、第１の開閉弁３および第２の開閉弁４の構造うち、テスト油閉塞空間Ｒ３とテスト油閉塞空間Ｒ４が略同じ容積であることを特徴としたが、流通、遮断動作に伴い移動する弁部材３ｂ、４ｂの先端部３ｂｓ、４ｂｓにおける移動体積Ｖ３、Ｖ４が略同じ容積であるものでもよい。
第１の開閉弁３の遮断動作において弁部材３ｂが弁座３ａｓに近づくに従って弁部材３ｂの先端部３ｂｓの移動体積Ｖ３に応じてテスト油を圧縮されることを、第２の開閉弁４の流通動作による弁部材４ｂの弁座４ａｓから離れるに従って、移動体積Ｖ４に応じてテスト油を減圧することで相殺することが可能である。その結果、第１の開閉弁３を流通動作から遮断動作に切換え直後に生じるウォータハンマ現象を緩和または防止することができる。したがって、この様な構成であっても、圧力降下量ΔＰを計測するための計測回路におけるウォータハンマに起因した圧力変動を防止することが可能である。
【００５８】
さらになお、以上説明した実施形態では、第１の開閉弁３の遮断動作によって流体供給経路部５ａつまり計測回路を閉回路にした後、所定時間Ｔ経過した時点で圧力降下量ΔＰを計測している。圧力降下量ΔＰを計測するための計測回路におけるウォータハンマに起因した圧力変動を防止することが可能であるので、所定時間Ｔを短縮することができる。したがって、本実施形態の検査装置１では、流体通路部品９の液密状態を検査する検査時間を短縮することが可能である。
【図面の簡単な説明】
【図１】本発明の実施形態の流体通路部品の検査装置の概略構成を示す構成図である。
【図２】図１中の第１の開閉弁、および第２の開閉弁の弁部構造を示す模式的断面図であって、図２（ａ）および図２（ｃ）は流体を流通させる開弁状態、図２（ｂ）および図２（ｄ）は流体を遮断する閉弁状態を示す断面図である。
【図３】本発明の実施形態に係る流体通路部品の検査過程における圧力変化特性を表す模式的グラフである。
【図４】図１中の第１の開閉弁および第２の開閉弁の作動状態を示す図である。
【図５】本実施形態に係る液密検査過程における圧力変化特性を示すグラフである。
【符号の説明】
１検査装置
２送油ポンプ（加圧流体供給源）
３第１の開閉弁
３ａバルブ
３ａｓ弁座
３ｂ弁部材
３ｂｓ先端部
４第２の開閉弁
４ａバルブ
４ａｓ弁座
４ｂ弁部材
４ｂｓ先端部
５流体供給経路
５ａ流体供給経路部
６圧力センサ（検出手段）
９プレシャレギュレータ（流体通路部品）
１１リリーフ弁（背圧調整弁）
２１流量調整装置
Ｒ３、Ｒ４テスト油閉鎖空間
Ｖ３、Ｖ４移動体積[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection apparatus for fluid passage parts, and more particularly to an inspection apparatus for inspecting a fluid tightness of fluid passage parts.
[0002]
[Prior art]
As a product inspection item of a fluid passage part, for example, an injector used for an internal combustion engine for an automobile or a pressure regulator, there is an oil tightness inspection of a valve portion. In the oil-tightness inspection of the valve part, for example, when the valve and nozzle needle constituting the valve part of the injector are in a closed state, the leakage state of pressurized fuel oil that oozes out from the seal part formed by the valve and nozzle needle is inspected. To do. As an inspection apparatus for performing this kind of oil tightness inspection, a test oil equivalent to fuel oil is supplied to an injector as a fuel passage component under pressure through a supply passage at a constant pressure, and then the supply passage side is provided with a shutoff valve or the like. There are some which judge the leakage state by the amount of pressure drop after a certain time after shutting off with an on-off valve.
[0003]
A pressure sensor is provided in the injector side supply path between the shut-off valve and the injector. The fuel passage part, the shut-off valve, and the injector-side supply path constitute a measurement circuit that measures the pressure drop amount related to oil tightness.
[0004]
[Problems to be solved by the invention]
In the inspection device of the prior art, when the test oil supply path is shut off by the closing operation of the shut-off valve, the water hammer is placed in the injector-side supply path constituting the measuring circuit by moving the shut-off valve to the valve seat. There was a problem that pressure fluctuation occurred. If this pressure fluctuation is large or if the pressure fluctuation is not attenuated by the predetermined elapsed time for determining the pressure drop amount, the oil tightness inspection accuracy may be lowered.
[0005]
The present invention has been made in consideration of such circumstances, and its purpose is to evaluate the liquid-tight state by the pressure drop amount of the fluid filled in the fluid passage part, and to improve the liquid-tightness inspection accuracy. An object of the present invention is to provide an inspection device for fluid passage parts.
[0006]
Another object is to evaluate the liquid-tight state by the pressure drop amount of the fluid filled in the fluid passage part. The fluid passage part can improve the liquid-tightness inspection accuracy and shorten the liquid-tightness inspection time. It is to provide an inspection apparatus.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a fluid passage part inspection apparatus for evaluating a liquid tightness state of a fluid passage part by a pressure drop amount of a pressurized liquid supplied to the fluid passage part. A fluid supply source, a fluid supply path capable of guiding the fluid pressurized by the pressurized fluid supply source to a fluid passage component as a liquid-tightness inspection target, and a pressurized fluid supply source of the fluid supply paths; A first on-off valve that is provided between the fluid passage parts and performs fluid flow and shut-off, and a fluid supply path portion that is formed between the first on-off valve and the fluid path part among the fluid supply paths. A second on-off valve that is branched and connected to the fluid supply path section, and a detecting means that detects a pressure in the fluid supply path, and the second on-off valve has a volume that varies depending on the flow and shut-off operation of the first on-off valve. It has approximately the same volume as the minute and is used for the flow and shut-off operation of the first on-off valve And blocks, to distribution operations.
[0008]
First, of the fluid supply paths for supplying fluid to the fluid passage parts, the fluid supply path section between the first on-off valve and the fluid passage parts is a pressurized fluid supply source by the shut-off operation of the first on-off valve. The fluid supply from is stopped.
[0009]
Furthermore, the fluid supply path section includes a second on-off valve that is branched and connected from the fluid supply path section, and has approximately the same volume as the volume that changes due to the flow and shut-off operation of the first on-off valve. In order to perform the shut-off and flow operations with respect to the flow and shut-off operation of the first on-off valve, for example, the volume reduced by the shut-off operation of the first on-off valve is reduced. It can be compensated by the increased volume by movement.
[0010]
Thus, it is possible to prevent water hammer that occurs immediately after the fluid supply path is closed by the shutoff operation of the fluid on / off valve, that is, the first on / off valve. Therefore, it is possible to prevent pressure fluctuations in the fluid supply path portion that has become a closed circuit due to the shut-off operation of the first on-off valve, that is, the liquid-tight measuring circuit for evaluating the pressure drop amount.
[0011]
According to a second aspect of the present invention, each of the first on-off valve and the second on-off valve includes a valve body having a valve seat, and a valve member whose tip can contact and separate from the valve seat. The volume that changes due to the shut-off operation is composed of a volume that moves the tip as the tip contacts and separates from the valve seat.
[0012]
Thus, the first on-off valve has a volume corresponding to the moving volume so as to compensate for the volume of movement of the tip as it contacts and separates from the valve seat at least during the flow and shut-off operation of the first on-off valve. Can be secured.
[0013]
For example, in the shut-off operation of the first on-off valve, the liquid is compressed by the tip of the valve member as the valve member approaches the valve seat, and as the valve member moves away from the valve seat of the valve member by the flow operation of the second on-off valve, It cancels out by depressurizing the liquid. As a result, the pressure fluctuation in the fluid supply path portion due to the shut-off operation of the first on-off valve is prevented.
[0014]
According to a third aspect of the present invention, each of the first on-off valve and the second on-off valve includes a valve body having a valve seat, and a valve member whose tip can contact and separate from the valve seat. The volume that changes due to the shut-off operation is composed of an inner fluid space that is defined between the inner periphery of the valve body and the outer periphery of the valve member in a state in which the tip portion is in contact with the valve seat.
[0015]
As a result, the first on-off valve shuts off the first on-off valve out of the fluid accommodated in the first on-off valve in the flow and shut-off operation of the first on-off valve, so that the fluid A second on-off valve that communicates the internal fluid space defined between the inner periphery of the valve body and the outer periphery of the valve member separated from the supply path portion with the fluid supply path portion by the flow operation of the second on-off valve Can be supplemented by the internal fluid space.
[0016]
According to the fourth aspect of the present invention, the second on-off valve and the first on-off valve are the same, and two first on-off valves can be used.
[0017]
According to claim 5 of the present invention, it is possible to dispose a flow rate adjusting valve between the pressurized fluid supply source and the first on-off valve in the fluid supply path.
[0018]
For example, when applied to a fuel pressure control valve that controls the pressure of fuel supplied to an internal combustion engine as a fluid passage component, measuring the operating pressure at a predetermined constant flow rate in the flow state of the first on-off valve; It is possible to prevent the pressure fluctuation due to the water hammer in the liquid-tightness inspection by switching from the flow operation of the on-off valve 1 to the shut-off operation.
[0019]
According to claim 6 of the present invention, factory air can be used as a drive source for performing fluid flow and shut-off operations in the first on-off valve and the second on-off valve, and an inexpensive oil tightness inspection apparatus is provided. be able to.
[0020]
According to the seventh aspect of the present invention, the fluid passage part can be suitably applied to a fuel supply part mounted on a drive source such as an internal combustion engine driven by fuel supply.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a fluid passage component inspection apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of an inspection apparatus for fluid passage parts according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing the valve structure of the first on-off valve and the second on-off valve in FIG. FIG. 3 is a schematic graph showing the pressure change characteristic in the inspection process of the fluid passage part according to the embodiment. FIG. 4 is a diagram showing an operating state of the first on-off valve and the second on-off valve in FIG. FIG. 5 is a graph showing the pressure change characteristic in the liquid-tightness inspection process according to the present embodiment in comparison with the pressure change characteristic in the prior art.
[0022]
As shown in FIG. 1, the fluid passage part inspection device 1 inspects the liquid-tight state of the fluid passage part 9 as an inspection target. In this inspection device 1, the pressure drop amount of the pressurized liquid supplied to the fluid passage component 9 is measured, and the liquid-tight state is determined from the measured pressure drop amount.
[0023]
The fluid passage component 9 may be a container formed by joining such as welding to store the fluid, a flow rate adjusting device for adjusting the flow rate of the fluid, or a fluid ejecting device for ejecting the fluid. However, any component, product, or apparatus may be used as long as it performs a liquid-tight inspection as one of the product or component performance items. For example, a fuel supply component such as a fuel injection valve or a fuel pressure control valve mounted on a drive source such as an internal combustion engine driven by supplying fuel may be used. The fluid passage component 9 described below in the present embodiment is a fluid pressure control valve (hereinafter referred to as a pressure) that regulates the fuel pumped up from the fuel tank by a fuel pump or the like to supply fuel to the internal combustion engine. Called a regulator).
[0024]
The pressure regulator 9 has a valve seat (not shown) and a valve seat (not shown) constituting a valve section (not shown) fixed to a case together with a diaphragm (not shown). The inside of the case is partitioned into a pressure adjustment side fuel chamber (not shown) and a fuel return side fuel chamber (not shown) by the valve seat and the diaphragm. When the valve portion opens, fuel flows from the pressure adjustment side into the fuel chamber on the fuel return side (low pressure side). As a result, the pressure regulator 9 of this type regulates the fuel on the pressure adjustment side to a predetermined fuel pressure according to the valve opening pressure of the valve portion when the fuel on the pressure adjustment side has a predetermined flow rate.
[0025]
As shown in FIG. 1, an inspection apparatus 1 includes a pressurized fluid supply source (hereinafter referred to as an oil feed pump) 2 that supplies test oil as a fluid, and a first on-off valve 3 that performs fluid flow and shut-off. A second on-off valve 4 that circulates and shuts off the fluid, a fluid supply path 5 that can guide the test oil pressurized by the oil feed pump 2 to the regulator 9, and the pressurized test oil And a pressure sensor 6 as pressure detecting means for detecting pressure. The test oil may be any oil or liquid as long as it has an oil property equivalent to a fluid that is adjusted by the pressure regulator 9 as a product, that is, a fuel. The oil property corresponding to the fuel is preferably a liquid that is less flammable than the fuel, for example, if the kinematic viscosity necessary for the flow rate measurement and the oil tightness inspection has the same properties as the fuel.
[0026]
As shown in FIG. 1, the oil feed pump 2 pumps the test oil from the tank 7 in which the test oil is stored through the filter 8 and discharges the test oil to the fluid supply path 5. The fluid supply path 5 is provided with a back pressure adjusting valve (hereinafter referred to as a relief valve) 11 in the middle of the path, and the test oil discharged from the oil feed pump 2 is set to a predetermined pressure P1 (see FIG. 3). . Of the test oil regulated by the relief valve 11, surplus test oil is returned to the tank 7 on the low pressure side of the test oil via the relief valve 11.
[0027]
The fluid supply path 5 is constituted by a known pipe. Note that a copper material is used as the material of the fluid supply path 5, and the joint portion of the pipe connecting the pipe and the pipe or the apparatus has a sleeve-type fastening structure. In addition, it is preferable that a portion of the fluid supply path 5 that contacts the test oil has a structure that can ensure electrical continuity, and is electrically grounded or held at the same potential.
[0028]
As shown in FIG. 1, the first on-off valve 3 is provided between the oil feed pump 2 and the pressure regulator 9 in the fluid supply path 5, and is pressurized by the oil feed pump 2 to the pressure regulator 9. Circulates and shuts off the guided test oil.
[0029]
In addition, as one of the inspection items of the fluid passage component (pressure regulator in this embodiment) 9 to be inspected, when evaluating the operating pressure when the flow rate of the test oil is set to a predetermined flow rate, the first A flow rate adjusting device 21 may be provided in the middle of the fluid supply path 5 between the on-off valve 3 and the oil feed pump 2. The flow rate adjusting device 21 includes a flow rate adjusting valve portion 21b for adjusting the flow rate of the test oil and a switching valve portion 21a for circulating and blocking the test oil. In this case, in the inspection process inspected by the pressure regulator 9 relating to the liquid-tight state described below, the switching valve portion 21a is always in a circulating state. The flow rate adjusting device 21 may be configured only by the flow rate adjusting valve portion 21b.
[0030]
As shown in FIG. 1, the pressure sensor 6 is provided in a fluid supply path portion 5 a formed between the first on-off valve 3 and the pressure regulator 9 in the fluid supply path 5. The pressure of the test oil in 5a is detected.
[0031]
As shown in FIG. 1, the second on-off valve 4 is branched from the fluid supply path 5a and connected.
[0032]
The fluid supply path 5a is connected to the fuel introduction side of the pressure regulator 9, that is, the pressure adjustment side. On the other hand, the fuel return side (low pressure side) of the pressure regulator 9 is a leaked test oil that oozes when the leak condition is inspected. Alternatively, it is attached to the tank 7 or a work mounting base (not shown) on the upper part of the tank 7 so that surplus test oil when evaluating the operating pressure can be reused.
[0033]
The first on-off valve 3, the fluid supply path 5a, the second on-off valve 4, and the pressure sensor 6 constitute a measurement circuit that measures the pressure drop amount related to the liquid regulator state of the pressure regulator 9, that is, the leakage state. ing.
[0034]
Here, the structure of the first on-off valve 3 and the second on-off valve 4 and the relationship between the flow of the first on-off valve 3 and the second on-off valve 4 and the shut-off operation will be described with reference to FIGS. . 2 (a) and 2 (c) show a valve open state in which the test oil is circulated, and FIGS. 2 (b) and 2 (d) show a valve closed state in which the test oil is shut off. FIG. ) And FIG. 2B show the structure of the first on-off valve 3, and FIG. 2C and FIG. 2D show the structure of the second on-off valve 4, respectively.
[0035]
As shown in FIGS. 2 (a) and 2 (c), the first on-off valve 3 and the second on-off valve 4, respectively, are valve bodies 3a and 4a having valve seats 3as and 4as, and a valve member 3b. 4b. The valve members 3b and 4b are accommodated in the valve bodies 3a and 4a so as to be movable in the axial direction. The tip portions 3bs and 4bs of the valve members 3b and 4b at the lower side in the axial direction in FIGS. 2 (a) and 2 (c) are arranged so as to contact and separate from the valve seats 3as and 4as. Openings 3ao and 4ao that open to the valve seats 3as and 4as are provided at the tips of the valve bodies 3a and 4a.
[0036]
In the closed state of the first on-off valve 3 in FIG. 2B, the fluid supply path 5a is connected to the opening 3a (hereinafter referred to as the tip side opening) 3ao. On the other hand, an internal fluid space defined between the outer periphery of the valve member 3b and the inner periphery of the valve body 3a in a state where the distal end portion 3bs of the valve member 3b is in contact with the valve seat 3as (hereinafter referred to as a test oil closed space). The fluid supply path 5 side opposite to the fluid supply path 5a is connected to an opening formed on the outer periphery of the valve body 3a (hereinafter referred to as an outer peripheral opening) (not shown) so as to communicate with R3. Connected. When the first on-off valve 3 is in the closed state, the test oil in the test oil closed space and the test oil in the fluid supply path portion 5a are in a separated state. On the other hand, when the first on-off valve 3 is in the open state, the test oil in the test oil closed space communicates with the test oil in the fluid supply path portion 5a. Accordingly, the flow of the test oil pressurized by the oil feed pump 2 to the distribution supply path portion 5a is circulated and blocked by the opening and closing operations of the first on-off valve 3, respectively.
[0037]
In the closed state of the second on-off valve 4 in FIG. 2C, the fluid supply path 5a is similarly connected to the distal end side opening 4ao. On the other hand, an outer peripheral side opening for communicating with the test oil closing space R4 defined between the outer periphery of the valve member 4b and the inner periphery of the valve body 4a in a state where the tip 3bs of the valve member 3b is in contact with the valve seat 3as. When the portion is formed, any of the cases where the outer peripheral side opening is not formed may be used. In addition, when the outer peripheral side opening is formed, as shown in FIG. 1, the outer peripheral side opening is configured to be closed by a blind plug or the like. Thereby, it is comprised so that the test oil in test oil blockade space R4 may not flow outside from the outer peripheral side opening part of the 2nd on-off valve 4. FIG. Therefore, the flow for guiding the test oil in the distribution supply path portion 5a to the test oil closed space R4 is circulated and blocked by the opening and closing operations of the second on-off valve 4, respectively.
[0038]
Furthermore, in this embodiment, as shown in FIG. 2, the first on-off valve 3 and the second on-off valve 4 are the same on-off valves, and the two first on-off valves 3 are used. Is preferred. Thereby, the test oil closed space R3 and the test oil closed space R4 have the same volume. Further, during the valve closing operation, the moving volumes V3 and V4 that move until the tip portions 3bs and 4bs of the valve members 3b and 4b come into contact with the valve seats 3as and 4as have the same volume.
[0039]
The moving volumes V3 and V4 are the product of the surface area of the tip portions 3bs and 4bs and the moving distance that moves as the tip portions 3bs and 4bs come into contact with and move away from each other.
[0040]
Further, as a drive source for performing the flow and shut-off operation of the first on-off valve 3 and the second on-off valve 4, as shown in FIG. 2, valve members 3b and 4b that move in the axial direction are used as factory air or the like. Use a pressure source. An electromagnetic force generator such as a solenoid may be used.
[0041]
Next, the relationship between the flow of the first on-off valve 3 and the second on-off valve 4 and the shut-off operation state is as follows: test oil in the flow supply path section 5a, that is, in the measurement circuit, in the inspection process of the pressure regulator 9 shown in FIG. In the pressure characteristics, there is the following relationship shown in FIG.
[0042]
(1) First, the pressure regulator 9 as the work of the object to be inspected is attached to the work mounting base of the fuel tank 7. Then, the fluid supply path 5 is connected to the pressure regulator 9 to form a measurement circuit. In this state, the first on-off valve 3 is in a cutoff state. The pressure of the test oil in the distribution supply path part 5a does not increase. This state is called a work set state A (see FIG. 3). At this time, the oil feed pump 5 may be in a stopped state in which the oil supply of the test oil is stopped or in a continuous operation state in which the test oil is supplied.
[0043]
As the operating states of the first on-off valve 3 and the second on-off valve 4, as shown in the work set state A in FIG. 4, the fluid shut-off state (valve closing operation) and the fluid circulation state (valve opening operation) Is set.
[0044]
(2) The test oil pressurized by the oil feed pump 5 is introduced into the distribution supply path portion 5a. Then, the pressure of the test oil in the distribution supply path portion 5a is increased to a predetermined pressure P1 as shown in FIG. In this state, the test oil having a predetermined pressure P1 continues to be fed through the distribution supply path portion 5a. This state is referred to as a test oil feed state B (see FIG. 3).
[0045]
As the operating states of the first on-off valve 3 and the second on-off valve 4, as shown in the test oil feed state B in FIG. 4, the fluid flow state (valve opening operation), the fluid shut-off state (valve closing operation) ) Is set.
[0046]
(3) When the pressure sensor 6 detects that the pressure of the test oil in the distribution supply path portion 5a has become a stable predetermined pressure P1, or when a predetermined elapsed time has elapsed in the test oil feed state B The distribution supply path 5a is closed, that is, the measurement circuit is closed. This state is referred to as an inspection state C related to the liquid-tight state. As the operating states of the first on-off valve 3 and the second on-off valve 4, as shown in the inspection state C relating to the liquid-tight state in FIG. 4, a fluid shut-off state (valve closing operation), a fluid circulation state (open state) Valve operation).
[0047]
In this state, the filling of the test oil of the predetermined pressure P1 into the distribution supply path portion 5a is completed, and the supply of the test oil pressurized by the oil feed pump 5 to the pressure regulator 9 is stopped. As a result, the valve body and the valve seat that form the operating pressure of the pressure regulator 9 have a good or bad seal state, and the test oil from the seal portion (not shown) of the valve body and the valve seat is low pressure side. The amount of leakage that leaks into the tank 7 is small and increases. Then, the pressure of the test oil filled in the distribution supply path portion 5a, that is, the measurement circuit, gradually decreases from the predetermined pressure P1 according to the leakage amount. As a result, as shown in FIG. 3, the pressure tightness of the pressure regulator 9 is determined by measuring the pressure drop amount ΔP after a predetermined time T has elapsed in the measurement circuit.
[0048]
In this way, the second on-off valve 4 is set so as to be in an operating state in which the first on-off valve 3 is in a shut-off and flow-through operation with respect to the flow and cut-off operation of the first on-off valve 3.
[0049]
When the first on-off valve 3 and the second on-off valve 4 are in the operating state, when the first on-off valve 3 is switched from the opening operation to the closing operation, the second on-off valve 4 is closed at substantially the same timing. It is preferable to switch from valve operation to valve opening operation. That is, when switching the first on-off valve 3 to the shut-off operation, it is preferable to switch the second on-off valve 4 to the circulation operation at substantially the same timing.
[0050]
In the inspection apparatus 1 having the above-described configuration, an inspection of a method for determining the liquid-tight state of the pressure regulator 9 based on the pressure drop amount ΔP of the test oil detected by the pressure sensor 6 provided in the distribution supply path portion 5a, that is, the measurement circuit. The accuracy was confirmed by experiment (see FIG. 5). In FIG. 5, a pressure change characteristic indicated by a solid line indicates a case where the inspection apparatus 1 of the present embodiment is used, and a pressure change characteristic indicated by a broken line indicates a case where the conventional inspection apparatus 1 is used. As shown in FIG. 5, when the inspection apparatus 1 of the present embodiment is used, the first on-off valve 3 is immediately after switching to the liquid-tight inspection state A, that is, compared to the case using the conventional inspection apparatus. It was confirmed that the water hammer phenomenon that occurs immediately after switching from distribution operation to shut-off operation is prevented.
[0051]
According to the above-described embodiment, the inspection apparatus 1 is configured to distribute and supply the first on-off valve 3 that circulates and shuts off the test oil to the distribution supply path portion 5a and the first on-off valve 3 separately. And a second on-off valve 4 branched from the path portion 5a and connected. Moreover, the first on-off valve 3 and the second on-off valve 4 are on-off valves having the same specifications, and two first on-off valves 3 are used. The second on-off valve 4 is set so as to be in an operating state in which the first on-off valve 3 is in a shut-off and flow-through operation with respect to the flow and cut-off operation of the first on-off valve 3. As a result, the first on-off valve 3 of the volume for filling the test liquid in the first on-off valve 3, the fluid supply path portion 5 a, and the second on-off valve 4 constituting the measurement circuit is cut off. The decreasing volume can be supplemented by increasing the flow of the second on-off valve 4. Moreover, since the first on-off valve 3 and the second on-off valve 4 are composed of the two first on-off valves 3, the volume that decreases is substantially the same as the volume that increases. As a result, the change in volume before and after the fluid supply path 5a, that is, the measurement circuit becomes a closed circuit, can be reduced or eliminated by the shut-off operation of the first on-off valve 3. Therefore, the first on-off valve 3 can be removed from the flow operation. The water hammer phenomenon that occurs immediately after switching to the shut-off operation can be prevented. Therefore, it is possible to prevent the pressure fluctuation caused by the water hammer in the fluid supply path 5a that is closed by the shutoff operation of the first on-off valve 3, that is, the measurement circuit for measuring the pressure drop ΔP. . The inspection accuracy for inspecting the liquid tightness of the fluid passage part 5 can be improved.
[0052]
Furthermore, according to the above-described embodiment, when the first on-off valve 3 is switched to the shut-off operation, the second on-off valve 4 is switched to the flow operation at substantially the same timing. The volume that decreases due to the above and the volume that increases due to the flow of the second on-off valve 4 can be accurately offset. Therefore, since the volume of the measurement circuit can be prevented from changing before and after the measurement circuit becomes a closed circuit due to the shut-off operation of the first on-off valve 3, it is caused by the water hammer in the measurement circuit for measuring the pressure drop ΔP. Pressure fluctuations can be prevented.
[0053]
Furthermore, according to this embodiment described above, the flow rate adjusting device 21 can be provided in the middle of the fluid supply path 5 between the first on-off valve 3 and the oil feed pump 2. As a method for preventing the water hammer caused by the shut-off operation of the first on-off valve 3, it is conceivable to restrict the flow rate of the first on-off valve 3. In this method, the flow rate of the test oil that can flow to the fluid supply path 5 is limited by the flow rate of the first on-off valve 3 that is throttled to prevent water hammer. On the other hand, the first on-off valve 3 and the second on-off valve 4 used in the inspection apparatus 1 of the present embodiment are not characterized by restricting the flow rates of these, and are therefore required for product inspection in the fluid supply path 5. A large flow rate. Thereby, in the inspection apparatus 1 of the present embodiment, the pressure drop amount ΔP related to the liquid-tight state of the fluid passage component 9 is measured in the shut-off state of the first on-off valve 3, and the pressure fluctuation due to the water hammer is prevented. It is possible to perform an inspection for determining a function related to the flow rate of the fluid passage component 9 to be inspected in the flow state of the first on-off valve 3. When evaluating the operating pressure when the flow rate of the test oil is set to a predetermined flow rate, as one of the inspection items, like the pressure regulator 9 described as an application example of the fluid passage component to be inspected by the inspection device 1 Is preferred.
[0054]
Furthermore, according to the above-described embodiment, the valve members 3b and 4b that move in the axial direction are used as factory air or the like as a drive source that performs the flow and shut-off operations of the first on-off valve 3 and the second on-off valve 4. It is possible to use any pressure source. As a method for preventing the water hammer caused by the shut-off operation of the first on-off valve 3, the moving speed at which the valve member 3b moves electrically to the valve seat 3as is made variable, and the moving speed becomes slower as it approaches the valve seat. It can be considered to be expensive. Moreover, since the time until the first on-off valve 3 is closed becomes longer, the total time for inspecting the liquid-tight state becomes longer, and the productivity is lowered. On the other hand, in the first on-off valve 3 and the second on-off valve 4 used in the inspection apparatus 1 of the present embodiment, the moving speed of the valve members 3b and 4b is slowed as the valve seats 3as and 3bs are approached. Therefore, inexpensive factory air can be used as a drive source.
[0055]
When the fluid passage part 9 is a fuel passage part that supplies fuel to an internal combustion engine or the like, it is necessary to make the inspection device an explosion-proof structure in the performance inspection process of the manufacturing process. For example, when the on / off valve drive source is an electric drive device, it is necessary to purge the device with an inert gas such as nitrogen gas so that no sparks are generated, and the device, that is, the inspection device becomes expensive. On the other hand, in this embodiment, since factory air is used as a drive source for performing the flow and shut-off operation of the first on-off valve 3 and the second on-off valve 4, it is inexpensive. Therefore, the inspection apparatus 1 of the present embodiment is suitable for functional inspection such as an oil-tight state in a fuel passage component mounted on a drive source such as an internal combustion engine driven by supply of fuel as a fluid passage component to be inspected. It is.
[0056]
In the embodiment described above, the first on-off valve 3 and the second on-off valve 4 are on-off valves having the same specifications, and the two first on-off valves 3 are used. Even if the on-off valve 3 and the second on-off valve 4 are not the same type of on-off valve, the volume that decreases due to the shut-off operation of the first on-off valve 3 is increased by the circulation operation of the second on-off valve 4. Anything that can be supplemented is acceptable. For example, as a structure of the first on-off valve 3 and the second on-off valve 4, the test oil closed space R3 and the test oil closed space R4 may have substantially the same volume. Thereby, the volume of the test oil in the test oil closed space R3 separated from the test oil in the fluid supply path portion 5a by the shut-off operation of the first on-off valve 3 and the fluid by the circulation operation of the second on-off valve 4 The volume of the test oil in the test oil closed space R4 communicating with the test oil in the supply path portion 5a is substantially the same. As a result, the volume change in the fluid supply path portion 5a can be almost eliminated or eliminated by the shut-off operation of the first on-off valve 3. Therefore, even with such a configuration, it is possible to prevent pressure fluctuation caused by the water hammer in the measurement circuit for measuring the pressure drop amount ΔP.
[0057]
In the above description, among the structures of the first on-off valve 3 and the second on-off valve 4, the test oil closed space R3 and the test oil closed space R4 have substantially the same volume. The moving volumes V3 and V4 at the tip portions 3bs and 4bs of the valve members 3b and 4b that move with the movement may be substantially the same.
In the shut-off operation of the first on-off valve 3, the test oil is compressed according to the moving volume V3 of the tip 3bs of the valve member 3b as the valve member 3b approaches the valve seat 3as. It is possible to cancel the test oil by depressurizing the test oil according to the moving volume V4 as the valve member 4b moves away from the valve seat 4as. As a result, the water hammer phenomenon that occurs immediately after switching the first on-off valve 3 from the flow operation to the shut-off operation can be reduced or prevented. Therefore, even with such a configuration, it is possible to prevent pressure fluctuation caused by the water hammer in the measurement circuit for measuring the pressure drop amount ΔP.
[0058]
Furthermore, in the embodiment described above, the pressure drop amount ΔP is measured when a predetermined time T has elapsed after the fluid supply path 5a, that is, the measurement circuit is closed by the shut-off operation of the first on-off valve 3. Yes. Since it is possible to prevent pressure fluctuation caused by the water hammer in the measurement circuit for measuring the pressure drop amount ΔP, the predetermined time T can be shortened. Therefore, in the inspection apparatus 1 of this embodiment, it is possible to shorten the inspection time for inspecting the fluid tightness of the fluid passage component 9.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a schematic configuration of an inspection apparatus for fluid passage parts according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing the valve structure of the first on-off valve and the second on-off valve in FIG. 1, wherein FIGS. 2 (a) and 2 (c) circulate fluid. FIG. 2 (b) and FIG. 2 (d) are cross-sectional views showing a valve open state in which the fluid is shut off.
FIG. 3 is a schematic graph showing pressure change characteristics in an inspection process of a fluid passage part according to an embodiment of the present invention.
4 is a diagram showing an operating state of the first on-off valve and the second on-off valve in FIG. 1. FIG.
FIG. 5 is a graph showing a pressure change characteristic in a liquid tightness inspection process according to the present embodiment.
[Explanation of symbols]
1 Inspection device
2 Oil pump (pressurized fluid supply source)
3 First on-off valve
3a valve
3as valve seat
3b Valve member
3bs tip
4 Second on-off valve
4a valve
4as valve seat
4b Valve member
4bs tip
5 Fluid supply path
5a Fluid supply path
6 Pressure sensor (detection means)
9 Pressure regulator (fluid passage parts)
11 Relief valve (back pressure adjustment valve)
21 Flow control device
R3, R4 test oil enclosed space
V3, V4 travel volume

Claims

An inspection device for a fluid passage component that evaluates a liquid-tight state of a fluid passage component by a pressure drop amount of a pressurized liquid supplied to the fluid passage component,
A pressurized fluid supply source for supplying fluid, a fluid supply path capable of guiding the fluid pressurized by the pressurized fluid supply source to the fluid passage component as a liquid-tightness inspection target, and the fluid supply path A first on-off valve that is provided between the pressurized fluid supply source and the fluid passage part, and that circulates and shuts off a fluid; and the first on-off valve of the fluid supply path and the A second on-off valve that is branched and connected from a fluid supply path formed between the fluid passage part and a detecting means that detects a pressure in the fluid supply path;
The second on-off valve has substantially the same volume as the volume changed by the flow and shut-off operation of the first on-off valve, and shuts off and the flow operation with respect to the flow and shut-off operation of the first on-off valve. An inspection apparatus for fluid passage parts.

Each of the first on-off valve and the second on-off valve includes a valve body having a valve seat, and a valve member whose tip can contact and separate from the valve seat,
2. The fluid according to claim 1, wherein the volume that changes due to the circulation and blocking operation is configured such that the tip moves as the tip contacts and separates from the valve seat. Inspection device for passage parts.

Each of the first on-off valve and the second on-off valve includes a valve body having a valve seat, and a valve member whose tip can contact and separate from the valve seat,
The volume that changes due to the flow and shut-off operation is composed of an inner fluid space defined between the inner periphery of the valve body and the outer periphery of the valve member in a state in which the tip portion is in contact with the valve seat. The fluid passage component inspection device according to claim 1, wherein:

4. The fluid passage component according to claim 2, wherein the second on-off valve and the first on-off valve are the same, and the two first on-off valves are used. 5. Inspection equipment.

The flow rate adjustment valve is arrange | positioned between the said pressurized fluid supply source and the said 1st on-off valve among the said fluid supply paths, The any one of Claims 1-4 characterized by the above-mentioned. The inspection apparatus for fluid passage parts according to the item.

6. The drive source for performing fluid flow and shut-off operations in the first on-off valve and the second on-off valve is factory air, according to claim 1. Inspection device for fluid passage parts.

The fluid passage component inspection device according to any one of claims 1 to 6, wherein the fluid passage component is a fuel supply component mounted on a drive source driven by fuel supply. .