JP3874698B2

JP3874698B2 - Solenoid for solenoid valve

Info

Publication number: JP3874698B2
Application number: JP2002164461A
Authority: JP
Inventors: 久晴竹内; 正明加藤; 守康後藤; 榎本　　滋郁
Original assignee: Denso Corp; Nippon Soken Inc
Current assignee: Denso Corp; Soken Inc
Priority date: 2002-06-05
Filing date: 2002-06-05
Publication date: 2007-01-31
Anticipated expiration: 2022-06-05
Also published as: JP2004014700A

Description

【０００１】
【発明の属する技術分野】
本発明は、アーマチャを吸引する磁気吸引面に作動流体が触れた状態で使用される電磁弁用ソレノイドに関するものであり、特に磁気吸引面に加わる作動流体の圧力が高圧な電磁弁に用いて好適な技術である。
【０００２】
【従来の技術】
アーマチャを吸引するソレノイドの磁気吸引面に作動流体が触れた状態で使用される電磁弁がある（例えば、特開昭６４−７３１６６号公報に開示される可変吐出量高圧ポンプに使用される電磁弁等）。
この種の電磁弁の一例を図７を参照して説明する。
この電磁弁は、弁部Ｊ1 が設けられたニードルＪ2 、このニードルＪ2 に設けられた鉄製のアーマチャＪ3 を吸引するソレノイドＪ4 等から構成されるものであり、アーマチャＪ3 を収容する室内Ｊ5 には作動流体（燃料等）が満たされる。
【０００３】
【発明が解決しようとする課題】
ソレノイドＪ4 は、図７に示されるように、コイルＪ6 、樹脂製のコイル支持部材Ｊ7 、ステータコアＪ8 を備えるものであり、コイル支持部材Ｊ7 は作動流体で満たされる室内Ｊ5 に露出している。
従来の可変吐出量高圧ポンプのように、作動流体が軽油等の場合は、作動流体が樹脂製のコイル支持部材Ｊ7 に触れても問題はない。しかし、軽油に代えてジメチルエーテル等の液化ガス燃料を用いる場合は、液化ガスの飽和蒸気圧が高い（９０℃で約３ＭＰａ）ため、可変吐出量高圧ポンプへの燃料供給圧力が軽油と比較して非常に高い圧力となり、室内Ｊ5 に非常に高い圧力が加わる。
【０００４】
▲１▼第１の課題
上記の例のように、非常に高い圧力の作動流体が室内Ｊ5 に供給されると、樹脂製のコイル支持部材Ｊ7 が高い圧力によって変形等の破損が発生する可能性がある。
コイル支持部材Ｊ7 に破損が発生した場合は、室内Ｊ5 に高圧供給された作動流体がコイル支持部材Ｊ7 の破損部分を通ってステータコアＪ8 の上方へ漏れる可能性がある。
【０００５】
▲２▼第２の課題
また、作動流体がジメチルエーテルのようなエラストマと化学反応する場合は、材質がＮＢＲ製のＯリングＪ9 を使用する必要があるが、電磁弁のように発熱し、高温となる部位には耐熱が低く、使用できないという問題がある。
【０００６】
【発明の目的】
本発明は、上記の事情に鑑みてなされたものであり、その目的は、例えソレノイドの磁気吸引面に作動流体によって非常に高い圧力が加えられても、作動流体の圧力がコイルおよびコイル支持部材に作用しないようにしてコイル支持部材の破損や変形を防ぎ、作動流体がコイル支持部材を通って漏れることのない電磁弁用ソレノイドの提供にある。
【０００７】
【課題を解決するための手段】
〔請求項１の手段〕
請求項１の手段を採用することにより、次の作用と効果を奏する。
コイルが発生する磁力は、内周磁極部および外周磁極部を介して磁気吸引面に導かれる。内周磁極部と外周磁極部の間は磁気遮断部によって磁束の短絡が回避される。このため、コイルが発生する磁力は、内周磁極部および外周磁極部を介してアーマチャに作用し、アーマチャを磁気吸引面に吸引する。
【０００８】
電磁弁用ソレノイドの磁気吸引面には、金属製の蓋部材が設けられて収納部と室内とを区画シールしている。このため、例え室内に非常に高い圧力の作動流体が満たされて、作動流体の圧力が磁気吸引面に加えられても、その高い圧力はコイルおよびコイル支持部材に作用しない。この結果、樹脂製のコイル支持部材が高い圧力によって破損したり変形したりせず、室内に満たされた作動流体がコイル支持部材を通って漏れる不具合はない。
【０００９】
〔請求項２の手段〕
請求項２の手段を採用し、室内に露出する磁気遮断部の外径寸法を、コイル支持部材の外径寸法よりも小さく設けても良い。
このように設けることにより、磁気吸引面に対向するアーマチャの径を小さくすることができる。これによってアーマチャを軽量化でき、電磁弁の応答性を高めることができる。
【００１０】
〔請求項３の手段〕
非常に高い圧力の作動流体が室内に供給されると、磁気遮断部にはコイル側に抜け出る方向の強い力が加わる。
そこで、請求項３の手段を採用し、磁気遮断部の室内側の幅を収納部側の幅よりも大きく設けても良い。
このように設けることにより、磁気遮断部が受ける圧力を内周磁極部および外周磁極部で受けることができ、磁気遮断部の強度を高めることができる。
【００１１】
〔請求項４の手段〕
請求項４の手段を採用し、磁気遮断部の室内側の幅を段差部を介して収納部側の幅よりも大きく設けても良い。
このように設けることにより、段差部によって磁気遮断部の軸方向位置が定まるため内周磁極部、磁気遮断部および外周磁極部からなる蓋部材の組付精度が高められる。
【００１２】
〔請求項５の手段〕
請求項５の手段を採用し、磁気吸引面に触れる作動流体が、液化ガス燃料（ジメチルエーテル、ＬＰＧ等）であっても良い。
この場合、作動流体が超臨界に達して浸透性が極端に高くなっても、作動流体が金属製の蓋部材によってシールされるため、室内に満たされた作動流体がコイル支持部材を通って漏れる不具合はない。
また、作動流体としてジメチルエーテルのようなエラストマと化学反応する場合であっても、室内に満たされた作動流体がコイル支持部材を通って漏れる不具合はないため、高い信頼性を得ることができる。
【００１３】
【発明の実施の形態】
本発明の実施の形態を、複数の実施例と変形例を用いて説明する。
〔第１実施例〕
図１〜図３を参照して第１実施例を説明する。なお、以下の実施例では、理解の容易化を図るために図面の上下を電磁弁１の上下として説明するが、電磁弁１の組付方向を変えても良いことは言うまでもない。
【００１４】
図１は電磁弁１の断面図を示すものであり、この電磁弁１は、作動流体を高圧圧縮するポンプの圧縮室に装着され、開動作することで高圧に圧縮された作動流体を低圧側に連通させるものであり、バルブシート２が設けられたバルブボディ３、弁部４が設けられた弁体５、スペーサ６、リターンスプリング７、ソレノイド８およびハウジング９等より構成される。
【００１５】
バルブボディ３は、下端面に高圧圧縮された作動流体が満たされるものであり、バルブボディ３の軸芯には上下方向に伸びる弁体５の摺動孔１１が形成され、その摺動孔１１の下端には弁部４が着座するバルブシート２が形成されている。摺動孔１１の下部には作動流体を低圧側へ導くための横孔１２が形成されている。
また、バルブボディ３には、バルブボディ３とソレノイド８の間に形成される室内１３に作動流体を導く縦孔１４が形成されている。
【００１６】
弁体５は、バルブボディ３の摺動孔１１によって上下方向に摺動自在に支持されるニードル１５と、ソレノイド８の発生する磁力に引きつけられる鉄製のアーマチャ１６とを固着したものである。
ニードル１５の下端には、バルブシート２に着座して摺動孔１１の下端を閉塞する弁部４が形成されており、この弁部４がバルブシート２から離座するとバルブボディ３の下端面で圧縮された作動流体が横孔１２へ導かれる。
アーマチャ１６は、縦孔１４を介して作動流体が導かれる室内１３に配置されるものであり、ソレノイド８が磁力を発生するとアーマチャ１６がリターンスプリング７の付勢力に打ち勝ってソレノイド８の下端面（磁気吸引面１７）に引きつけられて弁部４がバルブシート２へ着座する。
【００１７】
スペーサ６は、バルブボディ３とソレノイド８の間に配置される筒体であり、バルブボディ３とソレノイド８の間にアーマチャ１６が可動するスペース（室内１３）を形成するものである。
リターンスプリング７は、弁体５を下方へ付勢する圧縮コイルバネであり、ソレノイド８のパイプ２４（後述する）のバネ支持部材２４ａと、弁体５とに挟まれた状態で保持される。
ソレノイド８は、磁力によって弁体５を上方へ吸引して、弁体５の弁部４をバルブシート２に着座させるものであり、詳細は後述する。
【００１８】
ハウジング９は、電磁弁１を例えばポンプ等の本体に装着するリテーニングナットであり、このハウジング９を本体に強く締めつけることにより、バルブボディ３、スペーサ６、ソレノイド８が軸方向に強く押しつけられる。
【００１９】
次に、ソレノイド８の詳細を説明する。
ソレノイド８は、図２および図３（ａ）に示されるように、コイル２１、コイル支持部材２２、ステータコア２３、パイプ２４等より構成される。
コイル２１は表面に絶縁皮膜が施された導電線を円筒状に巻回した周知なものであり、通電によって磁力を発生する。
コイル支持部材２２は、コイル２１およびコイル通電用のリード端子２５をモールドして保持する樹脂であり、コイル２１をモールドする部分は円筒状を呈する。
ステータコア２３は、コイル２１の周囲に磁路を形成する軟磁性体金属（鉄等）であり、コイル支持部材２２を収納する収納部２６を備える。
【００２０】
ソレノイド８の磁気吸引面１７には、室内１３に満たされる作動流体が例え非常に高圧でも、その作動流体が収納部２６内のコイル支持部材２２に浸入しないように室内１３と収納部２６とを区画シールする金属製の蓋部材３０が設けられている。
この蓋部材３０を全て磁性体金属で形成すると、蓋部材３０に磁路が形成されてコイル２１の発生した磁力が室内１３のアーマチャ１６に届かない。逆に、蓋部材３０を全て非磁性体金属で形成すると、蓋部材３０で磁路が遮断されてコイル２１の発生した磁力が室内１３のアーマチャ１６に届かない。
【００２１】
そこで、蓋部材３０は、ステータコア２３の内周側の磁力を室内１３に導く軟磁性体金属（鉄等）よりなる内周磁極部３１と、ステータコア２３の外周側の磁力を室内１３に導く軟磁性体金属（鉄等）よりなる外周磁極部３２と、内周磁極部３１と外周磁極部３２との間に配置された非磁性体金属（ステンレス、アルミニウム等）よりなるリング状の磁気遮断部３３とを接合してなる。
内周磁極部３１と磁気遮断部３３の内周接合部３４の全周、および磁気遮断部３３と外周磁極部３２の外周接合部３５の全周は、レーザ溶接、レーザビーム溶接、ろう付け等の手段によって封止されるものであり、内外周接合部３４、３５からステータコア２３内の収納部２６に作動流体が浸入できないように設けられている。
【００２２】
このように設けられることにより、作動流体として超高圧となる液化ガス燃料（ジメチルエーテル、ＬＰＧ等）を用いた場合であっても、上述したように作動流体が金属製の蓋部材３０によってシールされるため、室内１３に満たされた作動流体がコイル支持部材２２を破損させて漏れる不具合はない。
このため、ステータコア２３の上側のシール対策を廃止でき、従来技術で示したＯリングＪ9 （符号は図７参照）を廃止でき、電磁弁１に使用されるＯリングの数を減らすことができる。
さらに、作動流体としてジメチルエーテルのようなエラストマと化学反応する流体を用いる場合であっても、作動流体がＯリング等のゴム製のシール部材に触れないため不具合が発生せず、高い信頼性を得ることができる。
【００２３】
次に、図２および図３（ａ）を参照してソレノイド８の組立を説明する。
樹脂製のコイル支持部材２２でモールドされたコイル２１を、ステータコア２３の収納部２６に収納する。次に、ステータコア２３の中央の貫通穴にパイプ２４を挿入するとともに、内周磁極部３１、磁気遮断部３３、外周磁極部３２を上述のように接合した蓋部材３０をステータコア２３の下面に組付ける。
次に、図３（ａ）の矢印Ａに示すステータコア２３と蓋部材３０の接合部を全周に亘ってレーザ溶接等の溶接技術によって封止するとともに、図３（ａ）の矢印Ｂに示すパイプ２４と蓋部材３０の接合部を全周に亘ってレーザ溶接等の溶接技術によって封止する。
以上によって室内１３の作動流体がコイル支持部材２２に浸入しないソレノイド８の組立が完了する。
【００２４】
上記構成よりなる電磁弁１の作動および効果を説明する。
コイル２１が通電されて磁力を発生すると、その磁力は内周磁極部３１および外周磁極部３２を介して磁気吸引面１７に導かれる。内周磁極部３１と外周磁極部３２の間は磁気遮断部３３によって磁束の短絡が回避されているため、コイル２１が発生する磁力は、内周磁極部３１および外周磁極部３２を介して室内１３のアーマチャ１６を吸引する。アーマチャ１６が磁気吸引面１７に吸引されて上方へ変位すると、弁部４がバルブシート２に着座し、電磁弁１が閉じられる。
【００２５】
コイル２１の通電が停止されて磁力が消えると、リターンスプリング７の付勢力によって弁体５が下方へ押し戻され、弁部４がバルブシート２から離座し、電磁弁１が開かれる。
アーマチャ１６が配置される室内１３は、横孔１２および縦孔１４を介して低圧側に通じており、電磁弁１の開閉に関係なく作動流体が満たされる。
【００２６】
このように、室内１３には作動流体が満たされるが、コイル２１およびコイル支持部材２２は蓋部材３０によって完全に覆われており、作動流体がコイル２１およびコイル支持部材２２に触れることはない。
このため、非常に高い圧力の作動流体が室内１３に供給されても、その高い圧力はコイル支持部材２２に作用しない。この結果、樹脂製のコイル支持部材２２が高い圧力によって破損したり変形したりせず、作動流体が漏れる不具合はない。
【００２７】
次に、磁気遮断部３３について説明する。
室内１３に非常に高い圧力の作動流体が供給されると、磁気遮断部３３にはコイル２１側に抜け出る方向の強い力が加わる。
しかるに、磁気遮断部３３の内外周は、図３（ａ）に示すように全周溶接されており、強度が十分あるため作動流体の高圧によって破損することはない。
【００２８】
上記に対し、図３（ｃ）に示すように、磁気遮断部３３の室内１３側の幅を段差部３６を介して収納部２６側の幅よりも大きく設けても良い。
このように設けることにより、磁気遮断部３３が受ける大きな圧力を段差部３６を介して内周磁極部３１および外周磁極部３２で受けることができ、磁気遮断部３３の強度が高められる。このように設けることによって高圧に対する磁気遮断部３３の強度が高まり、作動流体がコイル２１およびコイル支持部材２２に触れる不具合が発生しない。
なお、段差部３６によって磁気遮断部３３の軸方向位置が定まるため、内周磁極部３１、磁気遮断部３３および外周磁極部３２からなる蓋部材３０の組付精度が高められる。
【００２９】
ここで、図３（ｂ）に示すように、磁気遮断部３３によってコイル支持部材２２の下面を蓋するように設けるとともに、段差部３６によって磁気遮断部３３の強度を高めた場合は、室内１３に露出する磁気遮断部３３の外径寸法ａ1 がコイル支持部材２２の外径寸法ｂ1 より大きくなってしまう。すると、弁体５のアーマチャ１６の外径を大きくする必要があり、大きくすることで重くなるため、結果的に電磁弁１の応答性が悪化してしまう。
【００３０】
そこで、この実施例の磁気遮断部３３は、図３（ａ）、（ｃ）に示すように、室内１３に露出する磁気遮断部３３の外径寸法ａ2 をコイル支持部材２２の外径寸法ｂ2 よりも小さく設けている。
このように設けることにより、弁体５のアーマチャ１６を小径化して軽量化できるため、電磁弁１の応答性を高めることができる。
【００３１】
〔第２実施例〕
この第２実施例は、図４に示すように、ジメチルエーテル等の液化ガスを燃料とするコモンレール式燃料噴射システムの可変吐出量高圧ポンプ４０の電磁弁１に本発明を適用するものである。
図４に示す可変吐出量高圧ポンプ４０は、コモンレールへ高圧燃料を圧送するポンプであり、エンジンのクランク軸等によって回転駆動されるカム４１によってピストン４２が上下して加圧室４３の拡張と縮小を繰り返す。加圧室４３には燃料供給ポート４４から燃料が供給されるように設けられており、加圧室４３で加圧された燃料は燃料吐出ポート４５からコモンレールへ送られる。
また、加圧室４３には、加圧燃料を低圧側（燃料供給側）へ溢流させることで燃料吐出量を調整する電磁弁１が取り付けられており、上述したようにこの電磁弁１に本発明が適用される。
【００３２】
液化ガス燃料用の燃料噴射装置として、ディーゼルエンジン用のコモンレール式燃料噴射装置を適用する場合、基本的に既存の噴射システムを使用することができる。しかし、液化ガス燃料は軽油に比較して飽和圧力が高い（９０℃で約３ＭＰａ）。このため、可変吐出量高圧ポンプ４０へ送る燃料供給圧力が軽油と比較して非常に高い圧力となる。そして、室内１３には、図５に示す縦孔１４を介して可変吐出量高圧ポンプ４０へ送られた燃料供給圧力が加わるため、室内１３に満たされる液化ガス燃料（作動流体に相当する）の圧力は非常に高圧となってしまう。
【００３３】
このため、従来技術（符号、図７参照）で示したコイル支持部材が直接室内に露出するタイプのソレノイドでは、樹脂製のコイル支持部材が非常に高い圧力の液化ガス燃料によって破損する可能性がある。コイル支持部材に破損が発生した場合は、室内に高圧供給された作動流体がコイル支持部材の破損部分を通って漏れる可能性がある。また、コイル支持部材に破損が生じなくても、コイル支持部材が非常に高い圧力で変形し、その変形部分から高圧の作動流体が漏れる可能性もある。
【００３４】
そこで、本発明を適用したソレノイド８を用いることにより、第１実施例で示したように、非常に高圧の液化ガス燃料（作動流体）が室内１３に満たされても、コイル支持部材２２は蓋部材３０によって完全に覆われて液化ガス燃料がコイル支持部材２２に触れることはない。
つまり、非常に高い圧力の液化ガス燃料が室内１３に満たされた状態であっても、液化ガス燃料の圧力はコイル支持部材２２に作用しない。この結果、樹脂製のコイル支持部材２２が非常に高い圧力の液化ガス燃料によって破損したり変形したりせず、液化ガス燃料が漏れる不具合はない。
【００３５】
この第２実施例のソレノイド８は、図５に示すように、ステータコア２３を、断面略Ｔ字形を呈した中心コア５１と、断面略Ｌ字形を呈した外周コア５２とを接合して設けたものであり、蓋部材３０を構成する内周磁極部３１が中心コア５１と一体に形成され、外周磁極部３２が外周コア５２と一体に形成されたものである。
そして、この実施例では、中心コア５１と外周コア５２との間にコイル２１をモールドしたコイル支持部材２２および磁気遮断部３３を組付け、内周磁極部３１と磁気遮断部３３の内周接合部３４、および磁気遮断部３３と外周磁極部３２の外周接合部３５を、レーザ溶接、レーザビーム溶接等の溶接手段によって全周溶接し、内外周接合部３４、３５を溶接部５３、５４によって封止している。
【００３６】
また、この実施例の電磁弁１は、ステータコア２３とハウジング９との間にソレノイドケース５５を介在したものであり、外周磁極部３２とソレノイドケース５５の接合部５６も、レーザ溶接、レーザビーム溶接等の溶接手段によって全周溶接し、接合部５６を溶接部５７によって封止している。
なお、図５中に示す符号５８はＯリングを示すものであり、符号５９はコイル通電用の樹脂コネクタを示すものである。
【００３７】
この実施例では、中心コア５１と内周磁極部３１が一体化されるとともに、外周コア５２と外周磁極部３２が一体化されているため、部品点数が少なく、組付けが容易になるため、ソレノイド８のコストを抑えることが可能になる。
また、ステータコア２３の接合部が減るため、接合部で発生する漏れ磁束を減少させ、磁気抵抗の減少を図ることができ、ソレノイド８の磁気吸引力の低下を防ぐことができる。
【００３８】
〔第３実施例〕
この第３実施例のソレノイド８は、図６に示すように、中心コア５１の外周径を小さくし、代わりに外周コア５２の軸方向長を長くして、外周コア５２の内部に中心コア５１を圧入したものである。
このように設けることにより、中心コア５１と外周コア５２が密着するため、中心コア５１と外周コア５２の接合部による漏れ磁束の減少および磁気抵抗の減少を図ることができ、ソレノイド８の磁気吸引力の低下を防ぐことができる。
【００３９】
〔変形例〕
上記の実施例では、コイル２１が通電されているときに電磁弁１が閉じられ、コイル２１の通電が停止されている時に電磁弁１が開かれる例を示したが、通電と開閉が逆のタイプの電磁弁１のソレノイド８に本発明を適用しても良い。
また、液化ガス燃料以外の作動流体を制御する電磁弁に本発明を適用しても良い。
【図面の簡単な説明】
【図１】電磁弁の断面図である（第１実施例）。
【図２】ソレノイドの分解図である（第１実施例）。
【図３】ソレノイドの断面図である（第１実施例）。
【図４】可変吐出量高圧ポンプの断面図である（第２実施例）。
【図５】電磁弁の断面図である（第２実施例）。
【図６】電磁弁の断面図である（第３実施例）。
【図７】電磁弁の断面図である（従来例）。
【符号の説明】
８ソレノイド
１３室内
１６アーマチャ
１７磁気吸引面
２１コイル
２２コイル支持部材
２３ステータコア
２６収納部
３０蓋部材
３１内周磁極部
３２外周磁極部
３３磁気遮断部
３６段差部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solenoid for a solenoid valve that is used in a state where a working fluid is in contact with a magnetic suction surface that sucks an armature, and is particularly suitable for use in a solenoid valve in which the pressure of the working fluid applied to the magnetic suction surface is high. Technology.
[0002]
[Prior art]
There is an electromagnetic valve that is used when a working fluid is in contact with a magnetic suction surface of a solenoid that sucks an armature (for example, an electromagnetic valve used in a variable discharge high pressure pump disclosed in Japanese Patent Application Laid-Open No. 64-73166) etc).
An example of this type of solenoid valve will be described with reference to FIG.
This solenoid valve is composed of a needle J2 provided with a valve portion J1, a solenoid J4 for sucking an iron armature J3 provided on the needle J2, and the like, and is operated in a room J5 containing the armature J3. Fluid (fuel etc.) is filled.
[0003]
[Problems to be solved by the invention]
As shown in FIG. 7, the solenoid J4 includes a coil J6, a resin coil support member J7, and a stator core J8. The coil support member J7 is exposed to a chamber J5 filled with a working fluid.
When the working fluid is light oil or the like as in the conventional variable discharge high pressure pump, there is no problem even if the working fluid touches the resin coil support member J7. However, when liquefied gas fuel such as dimethyl ether is used instead of light oil, the saturated vapor pressure of the liquefied gas is high (about 3 MPa at 90 ° C.), so the fuel supply pressure to the variable discharge high pressure pump is higher than that of light oil. The pressure is very high, and a very high pressure is applied to the room J5.
[0004]
(1) First problem As in the above example, if a very high pressure working fluid is supplied to the chamber J5, the resin coil support member J7 may be damaged due to deformation or the like due to the high pressure. There is.
When the coil support member J7 is damaged, there is a possibility that the working fluid supplied to the chamber J5 at a high pressure leaks above the stator core J8 through the damaged portion of the coil support member J7.
[0005]
(2) Second problem Also, when the working fluid chemically reacts with an elastomer such as dimethyl ether, it is necessary to use an O-ring J9 made of NBR. There is a problem that the heat resistance is low and cannot be used.
[0006]
OBJECT OF THE INVENTION
The present invention has been made in view of the above circumstances, and the object thereof is to provide a coil and a coil support member that have a working fluid pressure even when a very high pressure is applied to the magnetic suction surface of the solenoid by the working fluid. Therefore, the solenoid valve solenoid is prevented from being damaged and deformed so that the working fluid does not leak through the coil support member.
[0007]
[Means for Solving the Problems]
[Means of Claim 1]
By adopting the means of claim 1, the following actions and effects are obtained.
The magnetic force generated by the coil is guided to the magnetic attraction surface via the inner peripheral magnetic pole part and the outer peripheral magnetic pole part. A short circuit of magnetic flux is avoided between the inner peripheral magnetic pole part and the outer peripheral magnetic pole part by the magnetic interrupting part. For this reason, the magnetic force generated by the coil acts on the armature via the inner peripheral magnetic pole portion and the outer peripheral magnetic pole portion, and attracts the armature to the magnetic attraction surface.
[0008]
A metal lid member is provided on the magnetic attraction surface of the solenoid for the solenoid valve so as to partition and seal the storage portion and the room. For this reason, even if the working fluid having a very high pressure is filled in the chamber and the pressure of the working fluid is applied to the magnetic suction surface, the high pressure does not act on the coil and the coil support member. As a result, the resin coil support member is not damaged or deformed by high pressure, and there is no problem that the working fluid filled in the room leaks through the coil support member.
[0009]
[Means of claim 2]
The means of claim 2 may be adopted, and the outer diameter of the magnetic shielding part exposed in the room may be smaller than the outer diameter of the coil support member.
By providing in this way, the diameter of the armature facing the magnetic attraction surface can be reduced. As a result, the armature can be reduced in weight, and the responsiveness of the solenoid valve can be improved.
[0010]
[Means of claim 3]
When a working fluid having a very high pressure is supplied into the room, a strong force is applied to the magnetic shield in the direction of coming out to the coil side.
Therefore, the means of claim 3 may be adopted, and the width on the indoor side of the magnetic shielding portion may be set larger than the width on the storage portion side.
By providing in this way, the pressure which a magnetic interruption | blocking part receives can be received in an inner peripheral magnetic pole part and an outer peripheral magnetic pole part, and the intensity | strength of a magnetic interruption | blocking part can be raised.
[0011]
[Means of claim 4]
The means of claim 4 may be adopted, and the width of the magnetic shielding portion on the indoor side may be provided larger than the width on the storage portion side through the stepped portion.
By providing in this way, the axial position of the magnetic shielding portion is determined by the stepped portion, so that the assembly accuracy of the lid member composed of the inner circumferential magnetic pole portion, the magnetic shielding portion, and the outer circumferential magnetic pole portion is enhanced.
[0012]
[Means of claim 5]
The working fluid that employs the means of claim 5 and touches the magnetic attraction surface may be liquefied gas fuel (dimethyl ether, LPG, etc.).
In this case, even if the working fluid reaches supercriticality and the permeability becomes extremely high, the working fluid is sealed by the metal lid member, so that the working fluid filled in the chamber leaks through the coil support member. There is no fault.
Even when the working fluid chemically reacts with an elastomer such as dimethyl ether, there is no problem that the working fluid filled in the chamber leaks through the coil support member, so that high reliability can be obtained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described using a plurality of examples and modifications.
[First embodiment]
A first embodiment will be described with reference to FIGS. In the following embodiments, the upper and lower parts of the drawing are described as the upper and lower parts of the electromagnetic valve 1 for easy understanding, but it goes without saying that the assembling direction of the electromagnetic valve 1 may be changed.
[0014]
FIG. 1 shows a cross-sectional view of a solenoid valve 1, which is mounted in a compression chamber of a pump that compresses a working fluid at a high pressure and opens the working fluid compressed to a high pressure by opening it. The valve body 3 is provided with a valve seat 2, the valve body 5 is provided with a valve portion 4, a spacer 6, a return spring 7, a solenoid 8, a housing 9, and the like.
[0015]
The valve body 3 has a lower end surface filled with a high-pressure compressed working fluid, and a sliding hole 11 of the valve body 5 extending in the vertical direction is formed on the shaft core of the valve body 3. A valve seat 2 on which the valve portion 4 is seated is formed at the lower end of the valve seat. A lateral hole 12 for guiding the working fluid to the low pressure side is formed below the sliding hole 11.
Further, the valve body 3 is formed with a vertical hole 14 that guides the working fluid to a chamber 13 formed between the valve body 3 and the solenoid 8.
[0016]
The valve body 5 is formed by fixing a needle 15 that is slidably supported in a vertical direction by a sliding hole 11 of the valve body 3 and an iron armature 16 that is attracted by the magnetic force generated by the solenoid 8.
A valve portion 4 is formed at the lower end of the needle 15 so as to be seated on the valve seat 2 and close the lower end of the sliding hole 11. When the valve portion 4 is separated from the valve seat 2, the lower end surface of the valve body 3 is formed. The working fluid compressed in step 1 is guided to the lateral hole 12.
The armature 16 is disposed in the chamber 13 through which the working fluid is guided through the vertical hole 14, and when the solenoid 8 generates a magnetic force, the armature 16 overcomes the urging force of the return spring 7 to lower the bottom surface of the solenoid 8 ( The valve portion 4 is seated on the valve seat 2 by being attracted to the magnetic attraction surface 17).
[0017]
The spacer 6 is a cylindrical body disposed between the valve body 3 and the solenoid 8, and forms a space (inside the room 13) in which the armature 16 can move between the valve body 3 and the solenoid 8.
The return spring 7 is a compression coil spring that urges the valve body 5 downward, and is held in a state sandwiched between a spring support member 24 a of a pipe 24 (described later) of the solenoid 8 and the valve body 5.
The solenoid 8 attracts the valve body 5 upward by magnetic force and seats the valve portion 4 of the valve body 5 on the valve seat 2, which will be described in detail later.
[0018]
The housing 9 is a retaining nut for mounting the electromagnetic valve 1 on a main body such as a pump. The valve body 3, the spacer 6, and the solenoid 8 are strongly pressed in the axial direction by strongly tightening the housing 9 to the main body.
[0019]
Next, details of the solenoid 8 will be described.
As shown in FIGS. 2 and 3A, the solenoid 8 includes a coil 21, a coil support member 22, a stator core 23, a pipe 24, and the like.
The coil 21 is a well-known coil in which a conductive wire having a surface coated with an insulating film is wound in a cylindrical shape, and generates a magnetic force when energized.
The coil supporting member 22 is a resin that molds and holds the coil 21 and the lead terminal 25 for energizing the coil, and the portion where the coil 21 is molded has a cylindrical shape.
The stator core 23 is a soft magnetic metal (iron or the like) that forms a magnetic path around the coil 21, and includes a storage portion 26 that stores the coil support member 22.
[0020]
The magnetic attraction surface 17 of the solenoid 8 is provided with the chamber 13 and the storage portion 26 so that the working fluid filled in the chamber 13 does not enter the coil support member 22 in the storage portion 26 even if the working fluid is very high pressure. A metal lid member 30 is provided for partition sealing.
When the lid member 30 is entirely made of a magnetic metal, a magnetic path is formed in the lid member 30 so that the magnetic force generated by the coil 21 does not reach the armature 16 in the room 13. On the other hand, if the lid member 30 is entirely made of a non-magnetic metal, the magnetic path is blocked by the lid member 30 and the magnetic force generated by the coil 21 does not reach the armature 16 in the room 13.
[0021]
Therefore, the lid member 30 includes an inner peripheral magnetic pole portion 31 made of a soft magnetic metal (iron or the like) that guides the magnetic force on the inner peripheral side of the stator core 23 to the chamber 13, and a soft that guides the magnetic force on the outer peripheral side of the stator core 23 to the chamber 13. An outer peripheral magnetic pole portion 32 made of a magnetic metal (such as iron) and a ring-shaped magnetic shielding portion made of a nonmagnetic metal (stainless steel, aluminum, etc.) disposed between the inner peripheral magnetic pole portion 31 and the outer peripheral magnetic pole portion 32 33 is joined.
Laser welding, laser beam welding, brazing, and the like are performed around the entire circumference of the inner circumferential joint portion 34 between the inner circumferential magnetic pole portion 31 and the magnetic shielding portion 33 and the entire circumference of the outer circumferential joint portion 35 between the magnetic shielding portion 33 and the outer circumferential magnetic pole portion 32. And is provided so that the working fluid cannot enter the storage portion 26 in the stator core 23 from the inner and outer peripheral joint portions 34 and 35.
[0022]
By providing in this way, even when liquefied gas fuel (dimethyl ether, LPG, or the like) having an ultrahigh pressure is used as the working fluid, the working fluid is sealed by the metal lid member 30 as described above. Therefore, there is no problem that the working fluid filled in the chamber 13 breaks the coil support member 22 and leaks.
For this reason, the measures for sealing the upper side of the stator core 23 can be eliminated, the O-ring J9 (see FIG. 7 for the reference) shown in the prior art can be eliminated, and the number of O-rings used in the solenoid valve 1 can be reduced.
Further, even when a fluid that chemically reacts with an elastomer such as dimethyl ether is used as the working fluid, since the working fluid does not touch the rubber seal member such as an O-ring, no malfunction occurs and high reliability is obtained. be able to.
[0023]
Next, the assembly of the solenoid 8 will be described with reference to FIG. 2 and FIG.
The coil 21 molded with the resin coil support member 22 is stored in the storage portion 26 of the stator core 23. Next, the pipe 24 is inserted into the central through hole of the stator core 23, and the cover member 30 in which the inner peripheral magnetic pole portion 31, the magnetic shielding portion 33, and the outer peripheral magnetic pole portion 32 are joined as described above is assembled on the lower surface of the stator core 23. wear.
Next, the joint between the stator core 23 and the lid member 30 indicated by an arrow A in FIG. 3A is sealed over the entire circumference by a welding technique such as laser welding, and is indicated by an arrow B in FIG. The joint between the pipe 24 and the lid member 30 is sealed over the entire circumference by a welding technique such as laser welding.
Thus, the assembly of the solenoid 8 in which the working fluid in the chamber 13 does not enter the coil support member 22 is completed.
[0024]
The operation and effect of the electromagnetic valve 1 having the above configuration will be described.
When the coil 21 is energized to generate a magnetic force, the magnetic force is guided to the magnetic attraction surface 17 via the inner peripheral magnetic pole portion 31 and the outer peripheral magnetic pole portion 32. Since a short circuit of magnetic flux is avoided between the inner peripheral magnetic pole part 31 and the outer peripheral magnetic pole part 32 by the magnetic interrupting part 33, the magnetic force generated by the coil 21 is generated indoors via the inner peripheral magnetic pole part 31 and the outer peripheral magnetic pole part 32. Thirteen armatures 16 are aspirated. When the armature 16 is attracted to the magnetic attraction surface 17 and displaced upward, the valve portion 4 is seated on the valve seat 2 and the electromagnetic valve 1 is closed.
[0025]
When the energization of the coil 21 is stopped and the magnetic force disappears, the valve body 5 is pushed back by the urging force of the return spring 7, the valve portion 4 is separated from the valve seat 2, and the electromagnetic valve 1 is opened.
The chamber 13 in which the armature 16 is disposed communicates with the low pressure side through the horizontal hole 12 and the vertical hole 14 and is filled with the working fluid regardless of whether the electromagnetic valve 1 is opened or closed.
[0026]
Thus, the working fluid is filled in the chamber 13, but the coil 21 and the coil support member 22 are completely covered by the lid member 30, and the working fluid does not touch the coil 21 and the coil support member 22.
For this reason, even if a working fluid having a very high pressure is supplied to the chamber 13, the high pressure does not act on the coil support member 22. As a result, the resin coil support member 22 is not damaged or deformed by high pressure, and there is no problem that the working fluid leaks.
[0027]
Next, the magnetic shielding part 33 will be described.
When a working fluid having a very high pressure is supplied to the chamber 13, a strong force is applied to the magnetic shielding unit 33 in the direction of coming out to the coil 21 side.
However, the inner and outer peripheries of the magnetic shielding part 33 are welded all around as shown in FIG. 3A, and have sufficient strength so that they are not damaged by the high pressure of the working fluid.
[0028]
On the other hand, as shown in FIG. 3C, the width of the magnetic shielding portion 33 on the side of the room 13 may be provided larger than the width of the storage portion 26 side through the step portion 36.
By providing in this way, a large pressure received by the magnetic shield part 33 can be received by the inner peripheral magnetic pole part 31 and the outer peripheral magnetic pole part 32 through the step part 36, and the strength of the magnetic interrupter part 33 is increased. By providing in this way, the strength of the magnetic shielding part 33 against high pressure is increased, and the problem that the working fluid touches the coil 21 and the coil support member 22 does not occur.
In addition, since the axial position of the magnetic shielding part 33 is determined by the step part 36, the assembly accuracy of the lid member 30 including the inner circumferential magnetic pole part 31, the magnetic shielding part 33, and the outer circumferential magnetic pole part 32 is improved.
[0029]
Here, as shown in FIG. 3B, when the magnetic shielding portion 33 is provided so as to cover the lower surface of the coil support member 22 and the strength of the magnetic shielding portion 33 is increased by the step portion 36, the indoor 13 The outer diameter dimension a1 of the magnetic shielding portion 33 exposed to the outer diameter becomes larger than the outer diameter dimension b1 of the coil support member 22. As a result, it is necessary to increase the outer diameter of the armature 16 of the valve body 5, and increasing the size makes it heavier. As a result, the responsiveness of the electromagnetic valve 1 deteriorates.
[0030]
In view of this, the magnetic shielding part 33 of this embodiment has an outer diameter dimension a2 of the magnetic shielding part 33 exposed to the interior 13 as shown in FIGS. 3 (a) and 3 (c). Smaller than that.
By providing in this way, the armature 16 of the valve body 5 can be reduced in diameter and reduced in weight, so that the responsiveness of the electromagnetic valve 1 can be improved.
[0031]
[Second Embodiment]
In the second embodiment, as shown in FIG. 4, the present invention is applied to the electromagnetic valve 1 of a variable discharge high pressure pump 40 of a common rail fuel injection system using liquefied gas such as dimethyl ether as fuel.
A variable discharge high-pressure pump 40 shown in FIG. 4 is a pump that pumps high-pressure fuel to a common rail. The piston 42 is moved up and down by a cam 41 that is rotationally driven by an engine crankshaft or the like. repeat. The pressurizing chamber 43 is provided so that fuel is supplied from the fuel supply port 44, and the fuel pressurized in the pressurizing chamber 43 is sent from the fuel discharge port 45 to the common rail.
The pressurizing chamber 43 is equipped with an electromagnetic valve 1 for adjusting the fuel discharge amount by overflowing pressurized fuel to the low pressure side (fuel supply side). The present invention is applied.
[0032]
When a common rail fuel injection device for a diesel engine is applied as a fuel injection device for liquefied gas fuel, an existing injection system can be basically used. However, the liquefied gas fuel has a higher saturation pressure (about 3 MPa at 90 ° C.) than light oil. For this reason, the fuel supply pressure sent to the variable discharge amount high-pressure pump 40 is very high compared to the light oil. And since the fuel supply pressure sent to the variable discharge amount high-pressure pump 40 via the vertical hole 14 shown in FIG. 5 is applied to the chamber 13, the liquefied gas fuel (corresponding to the working fluid) filled in the chamber 13 is applied. The pressure becomes very high.
[0033]
For this reason, in the solenoid of the type in which the coil support member shown in the prior art (reference numeral, see FIG. 7) is directly exposed to the room, the resin coil support member may be damaged by the liquefied gas fuel at a very high pressure. is there. When the coil support member is damaged, there is a possibility that the working fluid supplied with high pressure into the room leaks through the damaged portion of the coil support member. Even if the coil support member is not damaged, the coil support member may be deformed by a very high pressure, and high-pressure working fluid may leak from the deformed portion.
[0034]
Therefore, by using the solenoid 8 to which the present invention is applied, the coil support member 22 is not covered even if the chamber 13 is filled with very high pressure liquefied gas fuel (working fluid) as shown in the first embodiment. The liquefied gas fuel is not completely covered by the member 30 and does not touch the coil support member 22.
That is, the pressure of the liquefied gas fuel does not act on the coil support member 22 even when the chamber 13 is filled with the liquefied gas fuel having a very high pressure. As a result, the resin coil support member 22 is not damaged or deformed by the liquefied gas fuel at a very high pressure, and there is no problem that the liquefied gas fuel leaks.
[0035]
In the solenoid 8 of the second embodiment, as shown in FIG. 5, the stator core 23 is provided by joining a central core 51 having a substantially T-shaped section and an outer core 52 having a substantially L-shaped section. The inner peripheral magnetic pole portion 31 constituting the lid member 30 is formed integrally with the central core 51, and the outer peripheral magnetic pole portion 32 is formed integrally with the outer peripheral core 52.
In this embodiment, the coil support member 22 in which the coil 21 is molded and the magnetic shield part 33 are assembled between the central core 51 and the outer core 52, and the inner peripheral joint of the inner peripheral magnetic pole part 31 and the magnetic interrupter 33 is assembled. Part 34 and the outer peripheral joint part 35 of the magnetic shield part 33 and the outer peripheral magnetic pole part 32 are welded all around by welding means such as laser welding and laser beam welding, and the inner and outer peripheral joint parts 34 and 35 are welded by the weld parts 53 and 54. It is sealed.
[0036]
Further, the solenoid valve 1 of this embodiment has a solenoid case 55 interposed between the stator core 23 and the housing 9, and the joint 56 between the outer peripheral magnetic pole portion 32 and the solenoid case 55 is also laser-welded or laser-beam welded. The entire circumference is welded by a welding means such as the above, and the joint portion 56 is sealed by the weld portion 57.
In addition, the code | symbol 58 shown in FIG. 5 shows an O-ring, and the code | symbol 59 shows the resin connector for coil electricity supply.
[0037]
In this embodiment, since the central core 51 and the inner peripheral magnetic pole part 31 are integrated, and the outer peripheral core 52 and the outer peripheral magnetic pole part 32 are integrated, the number of parts is small, and the assembly becomes easy. The cost of the solenoid 8 can be reduced.
Moreover, since the joint part of the stator core 23 is reduced, the leakage magnetic flux generated at the joint part can be reduced, the magnetic resistance can be reduced, and the magnetic attraction force of the solenoid 8 can be prevented from being lowered.
[0038]
[Third embodiment]
In the solenoid 8 of the third embodiment, as shown in FIG. 6, the outer peripheral diameter of the central core 51 is reduced, and the axial length of the outer peripheral core 52 is increased instead. Is press-fitted.
By providing in this way, the central core 51 and the outer core 52 are in close contact with each other, so that the leakage magnetic flux and the magnetic resistance can be reduced at the joint between the central core 51 and the outer core 52, and the magnetic attraction of the solenoid 8. It can prevent power loss.
[0039]
[Modification]
In the above embodiment, the solenoid valve 1 is closed when the coil 21 is energized, and the solenoid valve 1 is opened when the coil 21 is de-energized. The present invention may be applied to the solenoid 8 of the electromagnetic valve 1 of the type.
Further, the present invention may be applied to an electromagnetic valve that controls a working fluid other than liquefied gas fuel.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a solenoid valve (first embodiment).
FIG. 2 is an exploded view of the solenoid (first embodiment).
FIG. 3 is a sectional view of a solenoid (first embodiment).
FIG. 4 is a cross-sectional view of a variable discharge high pressure pump (second embodiment).
FIG. 5 is a sectional view of a solenoid valve (second embodiment).
FIG. 6 is a sectional view of a solenoid valve (third embodiment).
FIG. 7 is a sectional view of a solenoid valve (conventional example).
[Explanation of symbols]
8 Solenoid 13 Indoor 16 Armature 17 Magnetic attracting surface 21 Coil 22 Coil support member 23 Stator core 26 Storage part 30 Cover member 31 Inner peripheral magnetic pole part 32 Outer peripheral magnetic pole part 33 Magnetic blocking part 36 Step part

Claims

A substantially cylindrical coil that generates a magnetic force when energized, a resin-made coil support member that houses this coil, and a stator core made of a magnetic metal metal that has a housing part that houses this coil support member With
A solenoid for a solenoid valve used in a state in which a working fluid touches a magnetic suction surface for sucking an armature,
The magnetic attraction surface is provided with a metal lid member that partitions and seals the chamber in which the armature is arranged and filled with the working fluid and the storage portion,
The lid member includes an inner peripheral magnetic pole portion made of a magnetic metal for guiding the magnetic force on the inner peripheral side of the stator core into the chamber, an outer peripheral magnetic pole portion made of a magnetic metal for guiding the magnetic force on the outer peripheral side of the stator core into the chamber, and A solenoid for solenoid valve, comprising: a ring-shaped magnetic shielding portion made of a non-magnetic metal disposed between the inner peripheral magnetic pole portion and the outer peripheral magnetic pole portion.

The solenoid for a solenoid valve according to claim 1,
The solenoid for solenoid valve, wherein an outer diameter dimension of the magnetic shielding portion exposed in the room is smaller than an outer diameter dimension of the coil support member.

The solenoid for a solenoid valve according to claim 1 or 2,
The solenoid for solenoid valves, wherein the magnetic shut-off portion is provided with a width on the indoor side larger than a width on the storage portion side.

The solenoid for a solenoid valve according to claim 3,
The solenoid for solenoid valve, wherein the magnetic blocking part is provided with a width on the indoor side larger than a width on the storage part side through a step part.

In the solenoid for solenoid valves according to any one of claims 1 to 4,
The solenoid for solenoid valve, wherein the working fluid that touches the magnetic attraction surface is liquefied gas fuel.