JP2004003455A

JP2004003455A - High pressure fuel supply and its method of manufacturing the same

Info

Publication number: JP2004003455A
Application number: JP2003082846A
Authority: JP
Inventors: Hisashi Endo; 遠藤　久志
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2002-04-05
Filing date: 2003-03-25
Publication date: 2004-01-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure fuel supply means which reduces concentration of stress to an accumulation container without increasing the number of parts nor causing the residue of foreign substances, thereby improving the pressure resistance of the accumulation container. <P>SOLUTION: A plated section 41 is formed on an inner wall 10a of the accumulation container 10 having an accumulation chamber 13 and a fuel passage 14 formed therein and on a chamfer portion 15 formed at a connecting portion between the accumulation chamber 13 and the fuel passage 14. The chamfer portion 15 is smoothed by the plated section 41 so as to reduce the concentration of stress. At the same time, the foreign substances sticking to the inner wall 10a of the accumulation container is covered with the plated section 41, so that it becomes unnecessary to grind the chamfer portion 15 and to wash the interior of the accumulation container 10. A non-plated section 42 where a plated section is not formed and the inner wall of the accumulation container 10 is exposed is formed on an attachment portion 31 to which a fuel pipe is attached and a seal portion 32 in contact with the fuel pipe in a liquid-tight state. Therefore, it is possible to prevent invasion of plating wastes into the seal portion 32 and reduction of the sealability due to deformation of the seal portion 32. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、蓄圧式の高圧燃料供給装置に関する。
【０００２】
【従来の技術】
従来、ディーゼルエンジンなどの高圧燃料供給装置として、蓄圧容器が形成する蓄圧室に高圧の燃料を蓄圧状態で蓄え、燃料噴射装置へ供給する蓄圧式の高圧燃料供給装置が公知である。高圧燃料供給装置の蓄圧容器は、燃料が蓄えられる蓄圧室と、蓄圧室へ燃料が流入または蓄圧室から燃料が流出するための燃料通路とが形成されている。燃料通路は蓄圧室に連通しており、蓄圧室と燃料通路とは軸がほぼ直交するように形成されている。そのため、蓄圧室と燃料通路との接続部分には角部が形成される。
【０００３】
近年、排気ガスの浄化および燃焼効率の向上などの要求から、燃料噴射圧力を増加し、燃料噴霧をより微粒化することが求められている。
しかし、蓄圧室に蓄えられる燃料圧力を増加すると、蓄圧室の燃料の圧力により蓄圧容器に加わる応力が増加する。蓄圧室と燃料通路との接続部分に角部が形成されている場合、蓄圧容器に加わる応力は角部に特に集中する。
【０００４】
そこで、例えば特許文献１に開示されているように、蓄圧容器を内周部材および外周部材から形成する高圧燃料供給装置が提案されている。この高圧燃料供給装置によると、外周部材に内周部材を圧入することにより、内周部材にあらかじめ圧縮応力を加え、蓄圧室の燃料から内周部材に加わる引張応力の低減を図っている。
【０００５】
【特許文献１】
特開２０００−７３９０８号公報
【０００６】
【発明が解決しようとする課題】
しかしながら、特許文献１に開示されている高圧燃料供給装置では、外周部材ならびに外周部材に圧入される内周部材から蓄圧容器を構成しているため、部品点数の増加、ならびに加工時間が増加を招くという問題がある。
また、他の従来技術として、角部への応力の集中を回避するため、蓄圧室と燃料通路との接続部分に形成される角部を電解加工により面取りする技術が公知である。この場合、電解加工により面取りされた部分は表面が荒れているため、このままでは局所的に応力の集中を招くおそれある。そのため、電解加工により角部の面取りを行った後、蓄圧容器の内部を流体研磨することにより、角部の表面の平滑化が図られている。しかしながら、流体研磨は加工に長時間を必要とするという問題がある。さらに、流体研磨を実施する場合、蓄圧容器の研磨により生じる研磨粉あるいは加工媒体に含まれる研磨剤が加工後の蓄圧容器に異物として残留する。そのため、流体研磨後に精密な洗浄工程を必要とし、さらなる加工時間の増大を招くという問題がある。
【０００７】
そこで、本発明の目的は、部品点数の増大および異物の残留を招くことなく、蓄圧容器への応力の集中を低減し、蓄圧容器の耐圧性が向上され、かつ信頼性の高い高圧燃料供給装置を提供することにある。
本発明の他の目的は、異物の残留を招くことなく、加工期間の短縮が図られる高圧燃料供給装置の製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
本発明の請求項１記載の高圧燃料供給装置によると、蓄圧室および燃料通路を形成する蓄圧容器の内壁ならびに面取り部にはめっき部が形成されている。これにより、蓄圧容器および燃料通路を形成する蓄圧容器の内壁、ならびに例えば電解加工により形成された面取り部は、めっき部により覆われる。そのため、蓄圧容器の内壁および面取り部はめっき部により平滑化される。したがって、部品点数の増加を招くことなく、蓄圧容器への応力の集中が低減され、蓄圧容器の耐圧性を向上することができる。また、めっき部を形成することにより、例えば研磨剤などの残留がなく、蓄圧容器および面取り部の表面に付着した異物は、めっき部により覆われる。したがって、異物の残留を招くことがなく、洗浄などの後処理が不要である。
【０００９】
また、蓄圧容器には蓄圧容器の内壁が露出している非めっき部が形成されている。取付部やシール部は、異物の発生防止ならびにシール性の確保の観点から、めっき部の形成は好ましくない。そのため、めっき部の形成が不要な取付部およびシール部には非めっき部が形成されている。これにより、シール部へのめっき片の侵入ならびにシール部の変形などが防止される。その結果、蓄圧容器に燃料配管が接続された場合、蓄圧容器と燃料配管との接続部からの燃料漏れを防止することができる。したがって、信頼性を向上することができる。
【００１０】
本発明の請求項２記載の高圧燃料供給装置によると、蓄圧容器は外壁にもめっき部を有している。高圧燃料供給装置は例えばエンジンが搭載される車両のエンジンルームに設置されるため、風雨にさらされる可能性がある。蓄圧容器の外壁にめっき部を形成することにより、蓄圧容器の表面はめっき部で保護され、蓄圧容器の腐食を防止することができる。
【００１１】
本発明の請求項３記載の高圧燃料供給装置によると、めっき部は硬質クロムめっきから形成されている。したがって、蓄圧容器の腐食を防止できるとともに、表面の強度を高めることができる。
本発明の請求項４記載の高圧燃料供給装置によると、取付部とシール部のみを非めっき部としている。
本発明の請求項５記載の高圧燃料供給装置によると、めっき部のめっき厚は３０μｍ以上に設定されている。
【００１２】
本発明の請求項６記載の高圧燃料供給装置の製造方法によると、軸孔、枝孔および面取り部が形成された棒状部材に取付部およびシール部を形成した後、封止部材を取り付けてめっき部を形成している。封止部材がシール部および取付部と当接することにより、封止部材が取り付けられた取付部およびシール部にはめっき部が形成されず、棒状部材の内壁が露出した非めっき部が形成される。また、めっき部の形成は軸孔、枝孔および面取り部が加工された後に実施される。そのため、棒状部材の軸孔、枝孔および面取り部にはめっき部が形成され、軸孔、枝孔および面取り部の加工後に残留した異物はめっき部により覆われる。めっき部は、例えばめっき液を流すことにより短期間かつ容易に形成される。したがって、異物の残留を招くことなく、加工時間の短縮を図ることができる。
【００１３】
本発明の請求項７記載の高圧燃料供給装置の製造方法によると、軸孔、枝孔および面取り部が形成された棒状部材にめっき部が形成される。めっき部が形成された後、取付部およびシール部が形成される。これにより、取付部およびシール部にはめっき部が形成されず、棒状部材の内壁が露出した非めっき部が形成される。そのため、非めっき部を形成するためのマスキングが不要となり、加工時間の短縮を図ることができる。したがって、異物の残留を招くことなく、加工時間の短縮を図ることができる。
【００１４】
本発明の請求項８記載の高圧燃料供給装置の製造方法によると、取付部およびシール部の形成の後、棒状部材は洗浄される。取付部およびシール部の形成により発生する異物は、洗浄によって容易に除去が可能であり、加工時間を短縮することができる。
【００１５】
本発明の請求項９記載の高圧燃料供給装置の製造方法によると、軸孔、枝孔および面取り部にめっき部を形成すると同時に棒状部材の外壁にもめっき部が形成される。そのため、棒状部材の表面の保護、ならびに腐食の防止を図ることができる。
本発明の請求項１０記載の高圧燃料供給装置の製造方法によると、棒状部材はめっき液に浸漬される。そのため、棒状部材の内壁および外壁に同時にめっき部を形成することができ、工数の増大を招くことがない。
【００１６】
【発明の実施の形態】
以下、本発明の実施の形態を示す複数の実施例を図面に基づいて説明する。
（第１実施例）
本発明の第１実施例による高圧燃料供給装置を図２に示す。高圧燃料供給装置１は、図示しない高圧ポンプから供給される高圧燃料を所定圧に蓄圧し、図示しないインジェクタに高圧燃料を供給するものである。高圧燃料供給装置１は、蓄圧容器１０および封止栓２０を備えている。
【００１７】
蓄圧容器１０には、燃料入口１１および燃料出口１２が形成されている。燃料入口１１は、図示しない高圧ポンプに接続されており、高圧ポンプから燃料が流入する。燃料出口１２は、図示しないインジェクタに接続されており、蓄圧容器１０に蓄えられている燃料がインジェクタへ流出する。
【００１８】
蓄圧容器１０は、蓄圧室１３および燃料通路１４を有している。蓄圧室１３は、蓄圧容器１０の内壁１０ａと、蓄圧容器１０の端部に設置されている封止栓２０の端部の内壁２０ａとから形成されている。燃料通路１４は、蓄圧容器１０の径方向に蓄圧室１３に連通して形成されている。蓄圧室１３と燃料通路１４との接続部分には面取り部１５が形成されており、蓄圧室１３と燃料通路１４との接続部分への応力の集中を低減している。
【００１９】
次に、燃料入口１１および燃料出口１２について説明する。なお、燃料入口１１および燃料出口１２はそれぞれ構成が同一である。したがって、以下、燃料出口１２について説明する。
図１に示すように、燃料出口１２には取付部３１およびシール部３２が形成されている。取付部３１は、図３に示すようにインジェクタに接続される燃料配管２が取り付けられる。取付部３１は雌ねじ部を有しており、燃料配管２に形成されている雄ねじ部とねじ結合される。シール部３２は平滑な平面状に形成されており、燃料配管２の先端部に形成されている当接部２ａと当接可能である。燃料配管２の雄ねじ部が取付部３１にねじ結合され、燃料配管２の当接部２ａがシール部３２に密着することにより、蓄圧容器１０と燃料配管２との間が液密にシールされる。これにより、燃料配管２の燃料通路２ｂと燃料通路１４とが接続される。一方、燃料入口１１の場合、取付部３１に高圧ポンプに接続される図示しない燃料配管が取り付けられる。
【００２０】
図１に示すように、蓄圧容器１０にはめっき部４１および非めっき部４２が形成されている。めっき部４１は、蓄圧室１３および燃料通路１４を形成する蓄圧容器１０の内壁１０ａと、面取り部１５とに形成されている。すなわち、図４に示すように、めっき部４１は燃料通路１４から蓄圧室１３にかけて形成されている。めっき部４１は、例えば硬質クロムめっきなどの金属のめっき層から形成されている。めっき部４１は、蓄圧容器１０の内壁１０ａおよび面取り部１５に概ね均一に形成されている。一方、非めっき部４２は、図１および図４に示すように燃料入口１１および燃料出口１２の取付部３１およびシール部３２に形成されている。非めっき部４２は、めっき層が形成されることなく蓄圧容器１０の内壁１０ａが露出している部分である。
【００２１】
取付部３１には図３に示す燃料配管２がねじ結合される。そのため、取付部３１にめっき部４１を形成した場合、燃料配管２の取り付けの際にめっきがはがれるおそれがある。この場合、はがれためっき片はシール部３２に噛み込み、蓄圧容器１０と燃料配管２との間のシール性の低下を招くおそれがある。また、シール部３２には燃料配管２の当接部２ａが当接するため、めっき部４１を形成した場合、シール部３２の形状精度が低下するおそれがある。この場合、形状精度の低下により、蓄圧容器１０と燃料配管２との間にシール性の低下を招くおそれがある。これらの理由から、取付部３１およびシール部３２に非めっき部４２を形成している。
【００２２】
図４に示すように、蓄圧容器１０の外壁１０ｂには内壁１０ａと同様にめっき部４３が形成されている。従来、蓄圧容器１０の加工時における腐食防止のため、蓄圧容器１０の外壁１０ｂにはリン酸塩被膜が形成されており、高圧燃料供給装置１を車両へ搭載する際にラッカーなどによる塗装が蓄圧容器１０に施されている。しかし、高圧燃料供給装置１が搭載される車両のエンジンルームは風雨にさらされるおそれがあり、リン酸塩被膜およびラッカー塗装では腐食の防止には十分ではない。そこで、本実施例のように蓄圧容器１０の内壁１０ａだけでなく外壁１０ｂにもめっき部４３を形成することにより、蓄圧容器１０の腐食をより確実に防止することができる。また、蓄圧容器１０の内壁１０ａへのめっき部４１の形成の際に、外壁１０ｂにめっき部４３を形成することができるため、工数の増大を招くこともない。
【００２３】
次に、第１実施例による高圧燃料供給装置１の製造方法について説明する。
図５に示すように蓄圧容器１０となる棒状部材５０に蓄圧室１３および燃料通路１４となる孔が形成される。棒状部材５０は例えば鋳造などにより形成され、燃料入口１１および燃料出口１２となる枝部５１が一体に形成される。形成された棒状部材５０には、蓄圧室１３となる軸方向へ伸びる軸孔５２と、軸孔５２に連通する燃料通路１４となる枝孔５３とが形成される。枝孔５３は枝部５１のそれぞれに形成される。軸孔５２および枝孔５３は、例えば切削などにより形成される。
【００２４】
軸孔５２および枝孔５３が形成された場合、図６（Ａ）に示すように軸孔５２と枝孔５３とが接続される部分には角部５４が形成される。角部５４には応力が集中しやすいため、角部５４には図６（Ｂ）に示すように面取り部５５が形成される。面取り部５５は、例えば電解加工により所定の半径の曲面状に形成される。
棒状部材５０に軸孔５２、枝孔５３および面取り部５５が形成されると、枝部５１のそれぞれに図７に示すように取付部５６およびシール部５７が形成される。取付部５６およびシール部５７は、例えば切削などにより形成される。
【００２５】
取付部５６およびシール部５７の形成が終了すると、図８に示すように各枝部５１に封止部材６０が装着される。封止部材６０は、例えばゴム系の材料により形成されている。封止部材６０は、内周側に連通路６１を有する中空の筒状に形成されている。封止部材６０は、シール部５７と当接する第一当接部７１、取付部５６と当接する第二当接部７２、ならびに枝部５１の端部と当接する第三当接部７３を有している。封止部材６０の第一当接部７１、第二当接部７２および第三当接部７３がそれぞれシール部５７、取付部５６および枝部５１の端部と当接することにより、シール部５７および取付部５６は、軸孔５２、枝孔５３および面取り部５５が形成されている棒状部材５０の内壁５０ａから隔離される。封止部材６０は、取付部５６に圧入またはねじ結合することにより枝部５１に取り付けられる。
【００２６】
棒状部材５０の各枝部５１に封止部材６０が取り付けられると、棒状部材５０はめっき液に浸漬される。めっき液は、図５に示す棒状部材５０の軸孔５２の開口５８および封止部材６０の連通路６１を経由して棒状部材５０の内周側へ流入する。これにより、封止部材６０により隔離されている取付部５６およびシール部５７を除く棒状部材５０の内壁５０ａにはめっき部８１が形成される。封止部材６０は第一当接部７１、第二当接部７２および第三当接部７３がそれぞれシール部５７、取付部５６および枝部５１の端部と当接しているため、シール部５７および取付部５６にはめっき液が流入することはない。また、棒状部材５０がめっき液に浸漬されることにより、棒状部材５０の内壁５０ａと同時に外壁にもめっき部が形成される。
【００２７】
以上の処理により、棒状部材５０の内壁５０ａおよび外壁にはめっき部８１が形成され、取付部５６およびシール部５７には非めっき部が形成される。棒状部材５０をめっき液から引き上げた後、封止部材６０を除去することにより、図１から４に示す蓄圧容器１０が完成する。この蓄圧容器１０に封止栓２０を圧入あるいはねじ結合することにより、高圧燃料供給装置１が完成する。
【００２８】
次に、蓄圧容器１０に形成されるめっき部４１による面粗度の向上について説明する。
蓄圧容器１０の実体強度は、表面係数と平滑材の強度との積、すなわち実体強度＝表面係数×平滑材の強度によって求められる。ここで、平滑材の強度とは、表面にきずのない状態の材料の強度を意味する。また、表面係数とは、製品強度に関係する最大応力部位の表面面粗度から決定される係数である。図８に示すように、表面係数は面粗度が大きくなるにしたがって小さくなる。
【００２９】
蓄圧容器１０の内壁１０ａの面粗度は、上記の面粗度と表面係数との関係から、Ｒ_ｍａｘ＝６．３ｚ以下であることが望ましい。蓄圧容器１０となる材料を切削加工などにより得られる一般的な面粗度である１２．５ｚに形成し、これをめっき部４１により平滑化してＲ_ｍａｘ＝６．３ｚ以下の平滑面に仕上げるには、めっき部４１のめっきの厚さは３０μｍ以上であることが望ましい。めっき部４１のめっきの厚さが増大するほど、切削時における加工面の粗度が大きな場合でも表面を平滑化効果が得られる。一方、めっき部４１のめっきの厚さが増大するほど、加工性の悪化および加工工数の増大を招く。そこで、平滑化の効果と加工性の悪化および加工工数の増大とを考慮し、めっき部４１の厚さの上限は８０μｍに設定するのが望ましい。
【００３０】
上記のめっき部４１を形成する場合、電解めっき法を用いることが望ましい。電解めっき法を用いることにより、蓄圧容器１０の内壁１０ａに形成される凹凸部のうち、凸部よりも凹部によりめっきが堆積しやすいという効果がある。そのため、めっき部４１の厚さが増大するにしたがって、蓄圧容器１０の内壁１０ａの平滑化を図ることができる。また、めっき部４１の形成の進行にともなってめっき浴に含まれる金属性の異物が形成されためっき部４１の表面に付着するおそれがある。そこで、めっき部４１の表面に異物が付着することによる表面の荒れを低減するため、めっき浴に含まれる金属性の異物を除去手段により除去することが望ましい。
【００３１】
以上、説明したように本発明の第１実施例の高圧燃料供給装置１の蓄圧容器１０は、面取り部１５が形成された後、めっき部４１が形成される。そのため、蓄圧室１３、燃料通路１４および面取り部１５が形成されている蓄圧容器１０の内壁１０ａはめっき部４１により平滑化される。したがって、部品点数の増加を招くことなく、蓄圧容器１０への応力の集中を低減することができ、蓄圧容器１０の耐圧性を向上することができる。また、めっき部４１を形成することにより、蓄圧容器１０の内壁１０ａが平滑化されるため、面取り部１５の形成後の例えば流体研磨などの処理が不要となる。これにより、流体研磨後の砥粒など異物の残留がなく、めっき部４１の形成前に蓄圧容器１０の内壁１０ａに付着していた異物はめっき部４１により覆われる。したがって、蓄圧容器１０への異物の残留を低減することができる。さらに、取付部３１およびシール部３２に非めっき部４２を形成することにより、めっきのはがれによる異物の発生、ならびにシール性の低下を防止することができ、蓄圧容器１０と燃料配管２との接続部からの燃料漏れを防止することができる。したがって、高圧燃料供給装置１の信頼性を高めることができる。
【００３２】
また、第１実施例では、めっき部４１の形成により蓄圧容器１０の内壁１０ａが平滑化される。そのため、長期間を必要とする流体研磨、ならびに流体研磨にともなう洗浄が不要となる。したがって、加工工数の低減および加工時間の短縮を図ることができる。
さらに、第１実施例では、蓄圧容器１０の外壁１０ｂにもめっき部４３が形成される。そのため、蓄圧容器１０の腐食を防止することができ、高圧燃料供給装置１の寿命を延長することができる。また、蓄圧容器１０の外壁１０ｂへのめっき部４３の形成は、内壁１０ｂへのめっき部４１の形成と同時に実施することができるため、加工工数の増大および加工時間の延長を招くことがない。
【００３３】
（第２実施例）
本発明の第２実施例による高圧燃料供給装置について説明する。第２実施例は製造工程が第１実施例と異なり、完成した高圧燃料供給装置は第１実施例と同様である。
第１実施例による図５に示すように、棒状部材５０には蓄圧室１３となる軸孔５２ならびに燃料通路となる枝孔５３が形成される。棒状部材５０には燃料入口１１および燃料出口１２となる枝部５１が一体に形成されている。また、軸孔５２と枝孔５３とが接続される部分には面取り部５５が形成される。
【００３４】
棒状部材５０に軸孔５２、枝孔５３および面取り部５５が形成されると、棒状部材５０はめっき液に浸漬される。これにより、図１０に示すように棒状部材５０の内壁５０ａおよび外壁５０ｂにはめっき部８１が形成される。
めっき部８１が形成された棒状部材５０は、枝部５１に取付部およびシール部が形成される。取付部およびシール部は、枝部５１に形成されている枝孔５３の内径を拡大して成形される。取付部およびシール部は例えば切削などにより形成される。そのため、枝孔５３に形成されているめっき部８１の一部は除去され、取付部およびシール部はめっき部が形成されない非めっき部となる。その結果、取付部およびシール部が形成された枝部５１は、例えば第１実施例の図１に示す燃料出口と同一の形状となる。
【００３５】
棒状部材５０に取付部およびシール部が形成された後、取付部およびシール部の形成により発生した異物を除去するために棒状部材５０は洗浄される。取付部およびシール部の形成により発生した異物は、簡単な洗浄により容易に除去されるため、長期間の洗浄は不要である。
以上の工程により蓄圧容器１０が完成する。この蓄圧容器１０に封止栓２０を圧入あるいはねじ結合することにより、高圧燃料供給装置１が完成する。
【００３６】
第２実施例では、取付部およびシール部の形成に先立って棒状部材５０にめっき部８１を形成している。めっき部８１が形成された棒状部材５０に取付部およびシール部を形成することにより、封止部材６０の取り付けが不要である。したがって、蓄圧容器１０の加工を容易にすることができる。また、棒状部材５０にめっき部８１が形成された後に、取付部およびシール部を形成する場合でも、発生した異物の除去は容易であるため、加工工程の複雑化および長期間化を招くことはない。したがって、蓄圧容器１０の加工期間の短縮を図ることができる。
【００３７】
以上説明した複数の実施例では、蓄圧容器となる棒状部材に面取り部を形成した後に取付部およびシール部を形成する手順について説明したが、棒状部材に軸孔、枝孔、取付部およびシール部を形成した後に面取り部を形成する工程としてもよい。
【図面の簡単な説明】
【図１】図２のＩ−Ｉ線で切断した断面図である。
【図２】本発明の第１実施例による高圧燃料供給装置を示す模式的な断面図である。
【図３】本発明の第１実施例による高圧燃料供給装置に燃料配管が接続されている状態を示す断面図である。
【図４】本発明の第１実施例による高圧燃料供給装置の蓄圧室と燃料通路との接続部分の近傍を拡大した模式的な断面図である。
【図５】本発明の第１実施例による高圧燃料供給装置の製造方法を説明するための図であって、棒状部材に軸孔および枝孔が形成されている状態を示す模式的な断面図である。
【図６】図５の要部を拡大した図であって、（Ａ）は軸孔と枝孔との接続部に角部が形成されている状態を示す図であり、（Ｂ）は軸孔と枝孔との接続部に面取り部が形成されている状態を示す図である。
【図７】本発明の第１実施例による高圧燃料供給装置の製造方法を説明するための図であって、取付部およびシール部が形成されている枝部を示す模式的な断面図である。
【図８】本発明の第１実施例による高圧燃料供給装置の製造方法を説明するための図であって、枝部に封止部材が取り付けられている状態を示す模式的な断面図である。
【図９】表面の面粗度と表面係数との関係を示す模式図である。
【図１０】本発明の第２実施例による高圧燃料供給装置の製造方法を説明するための図であって、棒状部材の内壁および外壁にめっき部が形成されている状態を示す模式的な断面図である。
【符号の説明】
１　　高圧燃料供給装置
２　　燃料配管
１０　　蓄圧容器
１０ａ　内壁
１０ｂ　外壁
１３　　蓄圧室
１４　　燃料通路
１５　　面取り部
３１　　取付部
３２　　シール部
４１　　めっき部
４２　　非めっき部
４３　　めっき部
５０　　棒状部材
５１　　枝部
５２　　軸孔
５３　　枝孔
５５　　面取り部
６０　　封止部材
８１めっき部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an accumulator-type high-pressure fuel supply device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a high-pressure fuel supply device such as a diesel engine, a high-pressure fuel supply device of a pressure-accumulation type in which high-pressure fuel is stored in a pressure-accumulation state in a pressure-accumulation chamber formed by a pressure-accumulation container and supplied to a fuel injection device is known. The accumulator of the high-pressure fuel supply device has an accumulator in which fuel is stored, and a fuel passage through which fuel flows into or out of the accumulator. The fuel passage communicates with the accumulator, and the accumulator and the fuel passage are formed such that their axes are substantially orthogonal to each other. Therefore, a corner is formed at a connection portion between the accumulator and the fuel passage.
[0003]
In recent years, due to demands for purification of exhaust gas and improvement of combustion efficiency, it has been demanded to increase the fuel injection pressure and further atomize the fuel spray.
However, when the fuel pressure stored in the accumulator is increased, the stress applied to the accumulator by the pressure of the fuel in the accumulator increases. When a corner is formed at the connection between the accumulator and the fuel passage, the stress applied to the pressure accumulator is particularly concentrated on the corner.
[0004]
Therefore, as disclosed in Patent Document 1, for example, a high-pressure fuel supply device in which a pressure storage container is formed from an inner peripheral member and an outer peripheral member has been proposed. According to this high-pressure fuel supply device, by compressing the inner peripheral member into the outer peripheral member, a compressive stress is applied to the inner peripheral member in advance, thereby reducing the tensile stress applied from the fuel in the accumulator to the inner peripheral member.
[0005]
[Patent Document 1]
JP 2000-73908 A
[Problems to be solved by the invention]
However, in the high-pressure fuel supply device disclosed in Patent Literature 1, since the pressure accumulator is configured by the outer peripheral member and the inner peripheral member that is press-fitted into the outer peripheral member, the number of components increases, and the processing time increases. There is a problem.
Further, as another conventional technique, a technique of chamfering a corner formed at a connecting portion between a pressure accumulating chamber and a fuel passage by electrolytic processing in order to avoid concentration of stress on the corner is known. In this case, since the surface chamfered by the electrolytic processing has a rough surface, there is a possibility that a local concentration of stress may be caused as it is. Therefore, after chamfering the corners by electrolytic processing, the inside of the accumulator is fluid-polished to smooth the surface of the corners. However, fluid polishing has a problem that a long time is required for processing. Further, when performing fluid polishing, polishing powder generated by polishing the pressure accumulator or an abrasive contained in the processing medium remains as foreign matter in the pressure accumulator after processing. Therefore, there is a problem that a precise cleaning step is required after the fluid polishing, which causes a further increase in processing time.
[0007]
Therefore, an object of the present invention is to reduce the concentration of stress on the pressure accumulator, improve the pressure resistance of the pressure accumulator, and provide a highly reliable high-pressure fuel supply device without increasing the number of parts and remaining foreign matter. Is to provide.
Another object of the present invention is to provide a method of manufacturing a high-pressure fuel supply device capable of shortening a processing period without causing foreign matter to remain.
[0008]
[Means for Solving the Problems]
According to the high-pressure fuel supply device according to the first aspect of the present invention, the plating portion is formed on the inner wall and the chamfer of the accumulator which forms the accumulator and the fuel passage. Accordingly, the inner wall of the pressure accumulator and the pressure accumulator that forms the fuel passage, and the chamfered portion formed by, for example, electrolytic processing are covered with the plating portion. Therefore, the inner wall and the chamfered portion of the accumulator are smoothed by the plated portion. Therefore, the concentration of stress on the pressure accumulator can be reduced without increasing the number of parts, and the pressure resistance of the pressure accumulator can be improved. In addition, by forming the plated portion, for example, there is no residue of the abrasive or the like, and foreign matter attached to the surfaces of the pressure accumulator and the chamfered portion is covered by the plated portion. Therefore, no foreign matter remains, and no post-treatment such as cleaning is required.
[0009]
In addition, a non-plated portion where the inner wall of the pressure accumulator is exposed is formed in the pressure accumulator. It is not preferable to form a plated portion in the mounting portion and the seal portion from the viewpoint of preventing generation of foreign matter and ensuring sealing performance. Therefore, a non-plated portion is formed in the mounting portion and the seal portion where the formation of the plated portion is unnecessary. This prevents the plating pieces from entering the seal portion and preventing the seal portion from being deformed. As a result, when the fuel pipe is connected to the pressure accumulator, it is possible to prevent fuel leakage from the connection between the pressure accumulator and the fuel pipe. Therefore, reliability can be improved.
[0010]
According to the high-pressure fuel supply device of the second aspect of the present invention, the accumulator has a plating portion also on the outer wall. Since the high-pressure fuel supply device is installed in, for example, an engine room of a vehicle in which an engine is mounted, the high-pressure fuel supply device may be exposed to wind and rain. By forming the plating portion on the outer wall of the pressure accumulator, the surface of the pressure accumulator is protected by the plating portion, and corrosion of the pressure accumulator can be prevented.
[0011]
According to the high-pressure fuel supply device of the third aspect of the present invention, the plating portion is formed of hard chrome plating. Therefore, corrosion of the accumulator can be prevented, and the surface strength can be increased.
According to the high-pressure fuel supply device of the fourth aspect of the present invention, only the mounting portion and the seal portion are non-plated portions.
According to the high-pressure fuel supply device of the present invention, the plating thickness of the plating portion is set to 30 μm or more.
[0012]
According to the method of manufacturing a high-pressure fuel supply device according to claim 6 of the present invention, after the mounting portion and the sealing portion are formed on the rod-shaped member having the shaft hole, the branch hole, and the chamfered portion, the sealing member is mounted thereon, and the plating is performed. Part is formed. When the sealing member comes into contact with the sealing portion and the mounting portion, no plating portion is formed on the mounting portion and the sealing portion where the sealing member is mounted, and a non-plating portion where the inner wall of the rod-shaped member is exposed is formed. . The formation of the plated portion is performed after the shaft hole, the branch hole, and the chamfered portion are processed. Therefore, a plated portion is formed in the shaft hole, the branch hole, and the chamfered portion of the rod-shaped member, and foreign matter remaining after processing the shaft hole, the branch hole, and the chamfered portion is covered by the plated portion. The plating portion is easily formed for a short period of time by flowing a plating solution, for example. Therefore, the processing time can be shortened without causing foreign matter to remain.
[0013]
According to the method of manufacturing a high-pressure fuel supply device according to claim 7 of the present invention, the plated portion is formed on the rod-shaped member in which the shaft hole, the branch hole, and the chamfered portion are formed. After the plating portion is formed, the mounting portion and the seal portion are formed. As a result, a plating portion is not formed on the mounting portion and the seal portion, and a non-plating portion in which the inner wall of the rod-shaped member is exposed is formed. Therefore, masking for forming the non-plated portion is not required, and the processing time can be reduced. Therefore, the processing time can be shortened without causing foreign matter to remain.
[0014]
According to the method of manufacturing the high-pressure fuel supply device according to the eighth aspect of the present invention, the rod-shaped member is cleaned after the formation of the mounting portion and the seal portion. Foreign matter generated by the formation of the mounting portion and the seal portion can be easily removed by washing, and the processing time can be reduced.
[0015]
According to the method of manufacturing a high-pressure fuel supply device according to the ninth aspect of the present invention, the plated portion is formed on the shaft hole, the branch hole, and the chamfered portion, and at the same time, the plated portion is also formed on the outer wall of the rod-shaped member. Therefore, protection of the surface of the rod-shaped member and prevention of corrosion can be achieved.
According to the method for manufacturing a high-pressure fuel supply device according to claim 10 of the present invention, the rod-shaped member is immersed in the plating solution. Therefore, the plated portions can be formed on the inner wall and the outer wall of the rod-shaped member at the same time, and the man-hour is not increased.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a plurality of examples showing an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 2 shows a high-pressure fuel supply device according to a first embodiment of the present invention. The high-pressure fuel supply device 1 accumulates high-pressure fuel supplied from a high-pressure pump (not shown) to a predetermined pressure and supplies high-pressure fuel to an injector (not shown). The high-pressure fuel supply device 1 includes a pressure accumulator 10 and a sealing plug 20.
[0017]
A fuel inlet 11 and a fuel outlet 12 are formed in the pressure accumulator 10. The fuel inlet 11 is connected to a high-pressure pump (not shown), and fuel flows in from the high-pressure pump. The fuel outlet 12 is connected to an injector (not shown), and the fuel stored in the pressure accumulator 10 flows out to the injector.
[0018]
The pressure storage container 10 has a pressure storage chamber 13 and a fuel passage 14. The accumulator 13 is formed by an inner wall 10 a of the accumulator 10 and an inner wall 20 a at the end of the sealing plug 20 installed at the end of the accumulator 10. The fuel passage 14 is formed so as to communicate with the pressure accumulating chamber 13 in the radial direction of the pressure accumulating vessel 10. A chamfered portion 15 is formed at a connection portion between the pressure accumulation chamber 13 and the fuel passage 14 to reduce concentration of stress on a connection portion between the pressure accumulation chamber 13 and the fuel passage 14.
[0019]
Next, the fuel inlet 11 and the fuel outlet 12 will be described. The fuel inlet 11 and the fuel outlet 12 have the same configuration. Therefore, the fuel outlet 12 will be described below.
As shown in FIG. 1, a mounting portion 31 and a seal portion 32 are formed in the fuel outlet 12. The fuel pipe 2 connected to the injector is mounted on the mounting portion 31 as shown in FIG. The attachment portion 31 has a female screw portion, and is screwed to a male screw portion formed on the fuel pipe 2. The seal portion 32 is formed in a smooth planar shape, and can be in contact with the contact portion 2 a formed at the tip of the fuel pipe 2. The external thread portion of the fuel pipe 2 is screwed to the mounting portion 31, and the contact portion 2 a of the fuel pipe 2 is in close contact with the seal portion 32, so that the space between the pressure accumulator 10 and the fuel pipe 2 is sealed in a liquid-tight manner. . Thereby, the fuel passage 2b of the fuel pipe 2 and the fuel passage 14 are connected. On the other hand, in the case of the fuel inlet 11, a fuel pipe (not shown) connected to a high-pressure pump is attached to the attachment portion 31.
[0020]
As shown in FIG. 1, a plating section 41 and a non-plating section 42 are formed in the pressure accumulator 10. The plating part 41 is formed on the inner wall 10 a of the pressure storage container 10 forming the pressure storage chamber 13 and the fuel passage 14, and on the chamfered part 15. That is, as shown in FIG. 4, the plating portion 41 is formed from the fuel passage 14 to the pressure accumulating chamber 13. The plating portion 41 is formed of a metal plating layer such as hard chrome plating. The plating part 41 is formed substantially uniformly on the inner wall 10 a and the chamfered part 15 of the pressure accumulator 10. On the other hand, the non-plated portion 42 is formed in the attachment portion 31 and the seal portion 32 of the fuel inlet 11 and the fuel outlet 12 as shown in FIGS. The non-plated portion 42 is a portion where the inner wall 10a of the pressure accumulator 10 is exposed without forming a plating layer.
[0021]
The fuel pipe 2 shown in FIG. Therefore, when the plating portion 41 is formed on the mounting portion 31, the plating may be peeled off when the fuel pipe 2 is mounted. In this case, the peeled plating pieces may bite into the seal portion 32, which may cause a reduction in the sealing performance between the pressure accumulator 10 and the fuel pipe 2. Further, since the contact portion 2a of the fuel pipe 2 contacts the seal portion 32, when the plating portion 41 is formed, the shape accuracy of the seal portion 32 may be reduced. In this case, there is a possibility that the sealing performance between the pressure accumulator 10 and the fuel pipe 2 may be reduced due to a reduction in the shape accuracy. For these reasons, the non-plated portion 42 is formed on the attachment portion 31 and the seal portion 32.
[0022]
As shown in FIG. 4, a plating portion 43 is formed on the outer wall 10b of the pressure accumulator 10 similarly to the inner wall 10a. Conventionally, a phosphate coating is formed on the outer wall 10b of the pressure accumulator 10 in order to prevent corrosion during processing of the pressure accumulator 10, so that when the high-pressure fuel supply device 1 is mounted on a vehicle, the coating with a lacquer or the like is required to accumulate the pressure. It is applied to the container 10. However, the engine room of the vehicle in which the high-pressure fuel supply device 1 is mounted may be exposed to wind and rain, and the phosphate coating and the lacquer coating are not sufficient to prevent corrosion. Therefore, by forming the plating portion 43 not only on the inner wall 10a but also on the outer wall 10b of the pressure accumulator 10 as in the present embodiment, the corrosion of the pressure accumulator 10 can be more reliably prevented. Further, when forming the plating portion 41 on the inner wall 10a of the pressure accumulator 10, the plating portion 43 can be formed on the outer wall 10b, so that the number of steps is not increased.
[0023]
Next, a method of manufacturing the high-pressure fuel supply device 1 according to the first embodiment will be described.
As shown in FIG. 5, holes serving as the pressure accumulating chamber 13 and the fuel passage 14 are formed in the rod-shaped member 50 serving as the pressure accumulating container 10. The rod-shaped member 50 is formed, for example, by casting or the like, and a branch 51 serving as the fuel inlet 11 and the fuel outlet 12 is integrally formed. The formed rod-shaped member 50 is formed with a shaft hole 52 extending in the axial direction as the pressure accumulation chamber 13 and a branch hole 53 as the fuel passage 14 communicating with the shaft hole 52. The branch holes 53 are formed in each of the branch portions 51. The shaft hole 52 and the branch hole 53 are formed by, for example, cutting.
[0024]
When the shaft hole 52 and the branch hole 53 are formed, a corner 54 is formed at a portion where the shaft hole 52 and the branch hole 53 are connected as shown in FIG. Since stress is easily concentrated on the corner 54, a chamfered portion 55 is formed on the corner 54 as shown in FIG. The chamfered portion 55 is formed into a curved surface with a predetermined radius by, for example, electrolytic processing.
When the shaft hole 52, the branch hole 53, and the chamfered portion 55 are formed in the rod-shaped member 50, the mounting portion 56 and the seal portion 57 are formed in each of the branch portions 51 as shown in FIG. The attachment portion 56 and the seal portion 57 are formed by, for example, cutting.
[0025]
When the formation of the attachment portion 56 and the seal portion 57 is completed, the sealing member 60 is attached to each branch portion 51 as shown in FIG. The sealing member 60 is formed of, for example, a rubber-based material. The sealing member 60 is formed in a hollow cylindrical shape having a communication path 61 on the inner peripheral side. The sealing member 60 has a first contact portion 71 that contacts the seal portion 57, a second contact portion 72 that contacts the attachment portion 56, and a third contact portion 73 that contacts the end of the branch portion 51. are doing. When the first contact portion 71, the second contact portion 72, and the third contact portion 73 of the sealing member 60 contact the seal portion 57, the attachment portion 56, and the ends of the branch portions 51, respectively, the seal portion 57 is formed. The mounting portion 56 is isolated from the inner wall 50a of the rod 50 in which the shaft hole 52, the branch hole 53, and the chamfered portion 55 are formed. The sealing member 60 is attached to the branch portion 51 by press-fitting or screwing into the attachment portion 56.
[0026]
When the sealing member 60 is attached to each branch 51 of the rod-shaped member 50, the rod-shaped member 50 is immersed in the plating solution. The plating solution flows into the inner peripheral side of the rod-shaped member 50 via the opening 58 of the shaft hole 52 of the rod-shaped member 50 and the communication path 61 of the sealing member 60 shown in FIG. As a result, the plating portion 81 is formed on the inner wall 50a of the bar-shaped member 50 except for the mounting portion 56 and the seal portion 57 separated by the sealing member 60. The sealing member 60 has a first contact portion 71, a second contact portion 72, and a third contact portion 73, which are in contact with the seal portion 57, the attachment portion 56, and the ends of the branch portions 51, respectively. The plating solution does not flow into 57 and the mounting portion 56. Also, by immersing the rod-shaped member 50 in the plating solution, a plating portion is formed on the outer wall as well as on the inner wall 50a of the rod-shaped member 50.
[0027]
By the above processing, the plated portion 81 is formed on the inner wall 50a and the outer wall of the rod-shaped member 50, and the non-plated portion is formed on the mounting portion 56 and the seal portion 57. After the rod-shaped member 50 is pulled up from the plating solution, the sealing member 60 is removed, whereby the pressure accumulator 10 shown in FIGS. 1 to 4 is completed. The high-pressure fuel supply device 1 is completed by press-fitting or screw-connecting the sealing plug 20 to the pressure accumulator 10.
[0028]
Next, the improvement of the surface roughness by the plating part 41 formed in the pressure accumulator 10 will be described.
The actual strength of the pressure accumulator 10 is determined by the product of the surface coefficient and the strength of the smoothing material, that is, the actual strength = the surface coefficient × the strength of the smoothing material. Here, the strength of the smoothing material means the strength of the material in a state where there is no flaw on the surface. Further, the surface coefficient is a coefficient determined from the surface roughness of the maximum stress portion related to the product strength. As shown in FIG. 8, the surface coefficient decreases as the surface roughness increases.
[0029]
The surface roughness of the inner wall 10a of the pressure accumulator 10 is desirably R _max = 6.3z or less from the above relationship between the surface roughness and the surface coefficient. To a material for the pressure accumulator 10 is formed in the cutting, a common surface roughness obtained by such 12.5Z, finish R _{max =} 6.3z following smooth surface is smoothed by plating unit 41 so Preferably, the plating thickness of the plating portion 41 is 30 μm or more. As the thickness of the plating of the plating portion 41 increases, the effect of smoothing the surface can be obtained even when the roughness of the processed surface during cutting is large. On the other hand, as the plating thickness of the plating portion 41 increases, the workability deteriorates and the number of processing steps increases. Therefore, in consideration of the effect of smoothing, deterioration of workability, and increase in the number of processing steps, it is desirable to set the upper limit of the thickness of the plated portion 41 to 80 μm.
[0030]
When forming the plating portion 41, it is desirable to use an electrolytic plating method. By using the electrolytic plating method, there is an effect that plating is more easily deposited in the concave portion than in the convex portion among the concave and convex portions formed on the inner wall 10a of the pressure storage container 10. Therefore, as the thickness of the plating portion 41 increases, the inner wall 10a of the pressure accumulator 10 can be smoothed. Further, as the formation of the plating portion 41 progresses, there is a possibility that metallic foreign matter contained in the plating bath adheres to the surface of the formed plating portion 41. Therefore, in order to reduce the surface roughness due to the adhesion of foreign matter to the surface of the plating portion 41, it is desirable to remove metallic foreign matter contained in the plating bath by a removing means.
[0031]
As described above, in the accumulator 10 of the high-pressure fuel supply device 1 according to the first embodiment of the present invention, the plating portion 41 is formed after the chamfered portion 15 is formed. Therefore, the inner wall 10 a of the accumulator 10 in which the accumulator 13, the fuel passage 14, and the chamfer 15 are formed is smoothed by the plating part 41. Therefore, the concentration of stress on the pressure accumulator 10 can be reduced without increasing the number of components, and the pressure resistance of the pressure accumulator 10 can be improved. Further, by forming the plated portion 41, the inner wall 10a of the pressure accumulator 10 is smoothed, so that a process such as fluid polishing after forming the chamfered portion 15 becomes unnecessary. Accordingly, there is no foreign matter such as abrasive grains remaining after the fluid polishing, and the foreign matter that has adhered to the inner wall 10a of the pressure accumulator 10 before the formation of the plated portion 41 is covered by the plated portion 41. Therefore, it is possible to reduce the amount of foreign matter remaining in the pressure accumulator 10. Further, by forming the non-plated portion 42 on the mounting portion 31 and the seal portion 32, it is possible to prevent the generation of foreign matter due to the peeling of the plating and the deterioration of the sealing property, and to connect the pressure accumulator 10 with the fuel pipe 2. It is possible to prevent fuel leakage from the section. Therefore, the reliability of the high-pressure fuel supply device 1 can be improved.
[0032]
In the first embodiment, the inner wall 10a of the pressure accumulator 10 is smoothed by the formation of the plating portion 41. Therefore, fluid polishing that requires a long period of time and cleaning associated with fluid polishing are not required. Therefore, the number of processing steps and the processing time can be reduced.
Furthermore, in the first embodiment, a plating portion 43 is also formed on the outer wall 10b of the pressure accumulator 10. Therefore, corrosion of the pressure storage container 10 can be prevented, and the life of the high-pressure fuel supply device 1 can be extended. Further, the formation of the plating portion 43 on the outer wall 10b of the pressure accumulator 10 can be performed simultaneously with the formation of the plating portion 41 on the inner wall 10b, so that the number of processing steps and the processing time are not increased.
[0033]
(Second embodiment)
A high-pressure fuel supply device according to a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in the manufacturing process, and the completed high-pressure fuel supply device is the same as the first embodiment.
As shown in FIG. 5 according to the first embodiment, a rod-shaped member 50 is formed with a shaft hole 52 serving as a pressure accumulation chamber 13 and a branch hole 53 serving as a fuel passage. The rod-shaped member 50 is integrally formed with a branch 51 serving as a fuel inlet 11 and a fuel outlet 12. A chamfered portion 55 is formed at a portion where the shaft hole 52 and the branch hole 53 are connected.
[0034]
When the shaft hole 52, the branch hole 53, and the chamfered portion 55 are formed in the rod member 50, the rod member 50 is immersed in the plating solution. As a result, as shown in FIG. 10, the plating portion 81 is formed on the inner wall 50a and the outer wall 50b of the rod-shaped member 50.
In the bar-shaped member 50 on which the plating portion 81 is formed, the attachment portion and the seal portion are formed on the branch portion 51. The mounting portion and the seal portion are formed by enlarging the inner diameter of the branch hole 53 formed in the branch portion 51. The attachment portion and the seal portion are formed by, for example, cutting. Therefore, a part of the plated portion 81 formed in the branch hole 53 is removed, and the mounting portion and the seal portion are non-plated portions where no plated portion is formed. As a result, the branch portion 51 on which the attachment portion and the seal portion are formed has, for example, the same shape as the fuel outlet shown in FIG. 1 of the first embodiment.
[0035]
After the mounting portion and the seal portion are formed on the bar-shaped member 50, the bar-shaped member 50 is washed to remove foreign substances generated by the formation of the mounting portion and the seal portion. Foreign matter generated by the formation of the mounting portion and the seal portion is easily removed by simple cleaning, so that long-term cleaning is unnecessary.
The pressure accumulator 10 is completed by the above steps. The high-pressure fuel supply device 1 is completed by press-fitting or screw-connecting the sealing plug 20 to the pressure accumulator 10.
[0036]
In the second embodiment, a plating portion 81 is formed on the bar-shaped member 50 prior to forming the mounting portion and the seal portion. By forming the mounting portion and the seal portion on the rod-shaped member 50 on which the plated portion 81 is formed, the mounting of the sealing member 60 is unnecessary. Therefore, the processing of the pressure accumulator 10 can be facilitated. Further, even when the mounting portion and the seal portion are formed after the plating portion 81 is formed on the rod-shaped member 50, the generated foreign matter is easily removed, so that the processing step becomes complicated and a long time is not caused. Absent. Therefore, the processing period of the pressure accumulator 10 can be shortened.
[0037]
In the embodiments described above, the procedure for forming the mounting portion and the seal portion after forming the chamfered portion on the rod-shaped member serving as the pressure storage container has been described. However, the shaft hole, the branch hole, the mounting portion, and the seal portion are formed on the rod-shaped member. May be formed after the formation of the chamfered portion.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along line II of FIG.
FIG. 2 is a schematic sectional view showing a high-pressure fuel supply device according to a first embodiment of the present invention.
FIG. 3 is a sectional view showing a state in which a fuel pipe is connected to the high-pressure fuel supply device according to the first embodiment of the present invention.
FIG. 4 is a schematic cross-sectional view in which the vicinity of a connection portion between a pressure accumulation chamber and a fuel passage of the high-pressure fuel supply device according to the first embodiment of the present invention is enlarged.
FIG. 5 is a view for explaining a method of manufacturing the high-pressure fuel supply device according to the first embodiment of the present invention, and is a schematic cross-sectional view showing a state in which a rod-shaped member is formed with a shaft hole and a branch hole. It is.
FIG. 6 is an enlarged view of a main part of FIG. 5, wherein (A) is a view showing a state where a corner is formed at a connecting portion between the shaft hole and the branch hole, and (B) is a view showing It is a figure which shows the state in which the chamfer part is formed in the connection part of a hole and a branch hole.
FIG. 7 is a view for explaining a method of manufacturing the high-pressure fuel supply device according to the first embodiment of the present invention, and is a schematic cross-sectional view showing a branch portion where a mounting portion and a seal portion are formed. .
FIG. 8 is a view for explaining the method of manufacturing the high-pressure fuel supply device according to the first embodiment of the present invention, and is a schematic cross-sectional view showing a state where a sealing member is attached to a branch. .
FIG. 9 is a schematic diagram showing the relationship between surface roughness and surface coefficient.
FIG. 10 is a view for explaining the method of manufacturing the high-pressure fuel supply device according to the second embodiment of the present invention, and is a schematic cross-section showing a state where plated portions are formed on the inner wall and the outer wall of the rod-shaped member. FIG.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 high-pressure fuel supply device 2 fuel pipe 10 pressure storage vessel 10 a inner wall 10 b outer wall 13 pressure storage chamber 14 fuel passage 15 chamfered part 31 mounting part 32 sealing part 41 plating part 42 non-plating part 43 plating part 50 bar-shaped member 51 branch part 52 shaft hole 53 Branch hole 55 Chamfered part 60 Sealing member 81 Plating part

Claims

An accumulator having a pressure accumulator, a fuel passage communicating with the pressure accumulator, and a chamfer formed at a connection between the pressure accumulator and the fuel passage;
An attachment portion formed in the pressure accumulator, to which a fuel pipe connected to the fuel passage is attached;
A seal portion formed in the pressure accumulator and in contact with the fuel pipe;
An inner wall of the pressure accumulator that forms the pressure accumulator and the fuel passage, and a plating portion formed on the chamfered portion so that the inner wall surface is smoother than a bare ground,
A non-plated portion formed on the mounting portion and the seal portion, and exposing an inner wall of the pressure accumulator,
A high-pressure fuel supply device comprising:

The high-pressure fuel supply device according to claim 1, wherein the accumulator has a plating portion on an outer wall.

The high-pressure fuel supply device according to claim 1, wherein the plating portion is formed from hard chrome plating.

The high-pressure fuel supply device according to claim 1, wherein only the mounting portion and the seal portion are non-plated portions.

5. The high-pressure fuel supply device according to claim 1, wherein a plating thickness of the plating portion is set to 30 μm or more. 6.

A method for manufacturing a high-pressure fuel supply device to which a fuel pipe is connected,
In the rod-shaped member, a shaft hole extending in the axial direction, a branch hole communicating with the shaft hole, and a step of forming a chamfered portion at a corner formed at a connection portion between the shaft hole and the branch hole,
Forming a mounting portion to which the fuel pipe is mounted, and a seal portion capable of abutting on the fuel pipe, on the rod-shaped member on which the shaft hole, the branch hole, and the chamfered portion are formed;
Attaching the sealing member capable of contacting the attachment portion and the seal portion to the rod-shaped member, isolating the shaft hole and the branch hole from the attachment portion and the seal portion;
An inner wall forming the axial hole and the branch hole of the rod-shaped member to which the sealing member is attached, and a step of forming a plating portion on the chamfered portion;
A method for manufacturing a high-pressure fuel supply device, comprising:

A method for manufacturing a high-pressure fuel supply device to which a fuel pipe is connected,
In the rod-shaped member, a shaft hole extending in the axial direction, a branch hole communicating with the shaft hole, and a step of forming a chamfered portion at a corner formed at a connection portion between the shaft hole and the branch hole,
An inner wall forming the shaft hole and the branch hole of the rod-shaped member, and a step of forming a plating portion on the chamfered portion,
Forming a mounting portion to which the fuel pipe is mounted on the rod-shaped member on which the plating portion is formed, and a seal portion capable of contacting the fuel pipe;
A method for manufacturing a high-pressure fuel supply device, comprising:

8. The method according to claim 7, further comprising the step of cleaning the branch hole and the shaft hole after the mounting portion and the seal portion are formed.

9. The method of manufacturing a high-pressure fuel supply device according to claim 6, wherein when forming the plated portion, a plated portion is also formed on an outer wall of the rod-shaped member.

The method according to claim 9, wherein the rod-shaped member is immersed in a plating solution.