JP2004278392A - Fuel pressure adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel pressure adjusting device for reducing the generation of noise. <P>SOLUTION: The generation of vapor by a contraction flow of fuel on the downstream side of a valve seat port 40 is restrained by diffusing the fuel toward the outside from the inside of the valve seat port 40 when a valve element 32 separates from a valve seat 34 by arranging the valve element 32 for blocking up the valve seat port 40 on the downstream side of the valve seat 34. The device can be miniaturized by adopting a plate-like plate spring 28 as a means for energizing the valve element 32 in the direction for seating on the valve seat 34. The plate spring 28 is constituted so that the free end abutting on the valve element 32 maintains an attitude near vertical to the plate thickness directional axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００６】
上式（１）は、上記の板ばねの構成により、中央部の変位の増大に伴って外縁部と中央部がなす角度θが大きくなることを抑制できることを示している。すなわち請求項１に記載の燃料圧力調整装置では、弁体に当接する中央部の姿勢をその板厚方向軸線に対して垂直に近い姿勢に維持することができるため、弁座口の開口面積を板ばねの付勢力によって正確に制御できる。その結果、弁座口より上流のシステム圧を正確に調整することができる。
【０００７】
請求項２に記載の発明では、中央部の板厚方向軸線とほぼ垂直な方向に移動可能に弁体を中央部に当接させることにより、弁体を弁座方向に付勢すれば弁座形状に応じて弁体が自動調心されるようになる。これにより、閉弁時に確実に弁座口を閉塞することができる。
【０００８】
請求項３に記載の発明では、請求項１に記載の中央部と弁体とを一体化することにより構成を簡素化する。
請求項４に記載の発明では、隣り合う２つの環状部における外側の環状部の剛性を内側の環状部の剛性より高くすることにより、各環状部に生ずる歪みを一様に近づけることができる。
【０００９】
請求項５に記載の発明では、弁座口を閉塞する弁体を弁座の下流側に設けることにより、弁座から弁体が離座したときに弁座口の内側から外側に向かって燃料を拡散させ、弁座口の下流における燃料の縮流によるベーパの発生を抑制する。また、弁体を弁座に着座させる方向に付勢する手段として板状の板ばねを採用することにより、小型化できる。さらに、板ばねを次のように構成することにより、板ばねの付勢力によって弁座口の開口面積を正確に制御できる。すなわち、弁体に当接する自由端がその板厚方向軸線に対して垂直に近い姿勢を維持するように構成する。具体的には、板ばねの外縁部を固定端とし、板ばねの中央部を弁体に当接する自由端とする。また、基端が外縁部に接続された少なくとも２つのばね部の先端を中央部の外縁に周方向に等間隔に接続する。さらに、弁体に当接する中央部の外縁を周方向に等間隔に複数のばね部によって支持することにより、中央部の姿勢を板厚方向軸線に対して垂直に近い姿勢に維持することができる。したがって、請求項５に記載の燃料圧力調整装置では、弁座口の開口面積を板ばねの付勢力によって正確に制御できる。その結果、弁座口より上流のシステム圧を正確に調整することができる。
【００１０】
請求項６に記載の発明では、中央部の板厚方向軸線とほぼ垂直な方向に移動可能に弁体を中央部に当接させることにより、弁体を弁座方向に付勢すれば弁座形状に応じて弁体が自動調心されるようになる。これにより、閉弁時に確実に弁座口を閉塞することができる。
【００１１】
請求項７に記載の発明では、請求項５に記載の中央部と弁体とを一体化することにより構成を簡素化する。
請求項８に記載の発明では、ばね部をジグザグ形状にすることにより、ばね部の基端から先端までの距離を長くとることができる。この結果、ばね定数の小さい小型の板ばねを実現できる。
【００１２】
請求項９に記載の発明では、ばね部を渦巻き形状にすることにより、ばね部の基端から先端までの距離を長くとることができる。この結果、ばね定数の小さい小型の板ばねを実現できる。
請求項１０に記載の発明では、ばね部の先端から基端に向かって剛性を高くすることにより、ばね部の先端から基端までに生ずる歪みを一様に近づけることができる。
【００１３】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
（第一実施形態）
図１は、本発明による燃料圧力調整装置の第一実施形態を示す模式図である。燃料圧力調整装置としてのプレッシャレギュレータ１８は、例えば車両の燃料タンク１０からエンジンのインジェクタ１４に燃料ポンプ２６によって供給される燃料を所定のシステム圧に調整する装置である。
【００１４】
インタンク式の燃料ポンプ２６は、燃料タンク１０内に収容されている。燃料ポンプ２６の燃料吸入口にはサクションフィルタ３０が接続されている。燃料ポンプ２６の燃料吐出口には燃料フィルタ２２が接続されている。燃料ポンプ２６は、サクションフィルタ３０を通じて燃料タンク１０内の燃料を吸入し、昇圧した燃料を燃料フィルタ２２を通じてインジェクタ１４に供給する。
【００１５】
プレッシャレギュレータ１８は、燃料フィルタ２２から吐出される燃料をインジェクタ１４に供給するための第二配管１２から分岐した第三配管１６に接続されている。プレッシャレギュレータ１８は、ハウジング３８、シート部材４２、弁体３２及び板ばね２８を備えている。
【００１６】
図２は本発明による燃料圧力調整装置の第一実施形態を示す断面図である。
ハウジング３８は、第三配管１６に接続される導入口２０と、燃料タンク１０の内部に通じる吐出口３６とを有する筒状の金属部材である。導入口２０には第三配管１６を通じて第二配管１２から燃料が導入される。
【００１７】
シート部材４２は、円筒状の金属部材であって、ハウジング３８の内壁に圧入などにより固定されている。シート部材４２の内壁２４は燃料流路を形成しており、シート部材４２の下流側端面の内縁部が環状の弁座３４を形成している。弁座３４の内側に形成されている開口部は弁座口４０を構成している。弁座口４０が開放されるとハウジング３８の導入口２０と吐出口３６とが連通する。
【００１８】
弁体３２は、球状の金属部材であってハウジング３８に収容され、ハウジング３８内でシート部材４２の吐出口側に位置し、板ばね２８によってハウジング３８の内部空間に拘束されている。弁体３２は、弁座３４に着座すると弁座口４０を閉塞する寸法に設定されている。また弁体３２は、板ばね２８の円形開口部７０にはまっている。
【００１９】
板ばね２８は、ハウジング３８の吐出口３６に設けられている。板ばね２８は、弁座口４０の中心軸線に垂直な姿勢で、ハウジング３８の吐出口側端部３９に外縁全周がかしめ接合されている。板ばね２８は、弁体３２を弁座３４に着座する方向に付勢している。板ばね２８の自由端の板厚方向軸線は弁座口４０の中心軸線に一致する。弁体３２を弁座３４に着座する方向に付勢する手段として平板状のばねを用いることにより、プレッシャレギュレータ１８の軸長を短くすることができる。弁体３２をハウジング３８内に拘束する手段として通孔が形成された板ばねを用いることにより、プレッシャレギュレータ１８の軸長を短くすることができ、また、プレッシャレギュレータ１８の構成を簡素化することができる。また、板ばね２８をハウジング３８に固定する手段としては、ねじ等を用いてもよいが、かしめ接合によりプレッシャレギュレータ１８の構成を簡素化することができ、また軸長を短くすることができる。
【００２０】
図３は、本発明の第一実施形態に係る板ばね２８を示す平面図である。板ばね２８は、外縁が円形の平板状のばねである。板ばね２８は、同心円上に配列された複数の環状部４４、４６、４８、５０、５２と、隣り合う２つの環状部を接続する接続部５４、５６、６６、６８とを備えている。各環状部の幅及び板厚は同一でもよいし、外側の環状部ほど幅又は板厚を増大させて剛性を高くしてもよい。板ばね２８には、同心円上にＣ字形状の複数の開口部５８、６０、６２、６４が形成され、中心部には円形の円形開口部７０が形成されている。
【００２１】
最も外側の環状部４４（以下、外縁環状部４４という。）は、請求項に記載の外縁部に相当する。最も内側の環状部５２（以下、中央環状部５２という。）は、請求項に記載の中央部に相当する。それ以外の環状部４６、４８、５０は請求項に記載の環状部に相当する。接続部６８は、環状部４６にとって請求項に記載の外側接続部に相当する。接続部５４は、環状部４６にとって請求項に記載の内側接続部に相当し、環状部４８にとって請求項に記載の外側接続部に相当する。接続部６６は、環状部４８にとって請求項に記載の内側接続部に相当し、環状部５０にとって請求項に記載の外側接続部に相当する。接続部５６は、環状部５０にとって請求項に記載の内側接続部に相当する。
【００２２】
中央環状部５２は板ばね２８の板厚方向（図３の紙面垂直方向）に力を受けるとその方向に変位する自由端である。中央環状部５２の内側に形成された円形開口部７０に弁体３２がはまっているため、弁体３２は中央環状部５２の板厚方向軸線に対して垂直な方向（図３の紙面平行方向）に移動しない。外縁環状部４４は弁座口４０の中心軸線に垂直な姿勢でハウジング３８に固定された固定端である。
【００２３】
弁座口４０の下流に弁体３２を設けたプレッシャレギュレータ１８では、弁座口４０を開放させる燃料の圧力が作用する面積は弁座口４０を閉塞している弁体３２の表面積だけである。このため、弁座口４０の下流に弁体３２を設けたプレッシャレギュレータ１８では、燃料流量に対する制御圧力の変化（圧力勾配ΔＰ（次式（２）参照））が小さくなるように、板ばね２８のばね定数を小さく設定することが望ましい。本実施形態では、単純な片持ち梁の形状ではなく、同心円上に重ねた複数の環状部４４、４６、４８、５０、５２を連結した形状にすることで、ばね定数が小さい小型の板ばね２８を実現している。
ΔＰ＝ｋｘ／Ｓ・・・式（２）
（ｋ：ばね定数、ｘ：弁体のリフト量、Ｓ：有効受圧面積）
【００２４】
中央環状部５２が弁体３２から板ばね２８の板厚方向に力を受けると、板ばね２８は図４に示すように弾性変形する。外縁環状部４４に対する中央環状部５２の傾きθ５は次式（３）で近似される。
θ５＝（θ２−θ１）＋（θ４−θ３）・・・式（３）
【００２５】
中央環状部５２に作用する力が増大すると、θ１〜θ４はそれぞれ増大するが、θ１〜θ４の総和の増分に比べると、θ５の増分は相当小さい。すなわち、板ばねが平板形状からジグザグ形状に変形するように、各環状部に半周間隔で内側接続部と外側接続部を設けているため、中央環状部に作用する力の増大に伴って外縁環状部４４に対する中央環状部５２の傾きθ５が増大することが抑制される。この結果、弁体３２に当接する中央環状部５２の姿勢をその板厚方向軸線に対して垂直に近い姿勢に維持することができる。
【００２６】
図５は弁体３２に当接する板ばねの自由端の姿勢と弁座口４０の開口面積の関係を説明するための模式図である。本実施形態の板ばね２８の場合、弁体３２に当接する中央環状部５２の姿勢がその板厚方向軸線Ｌに対して垂直に近い姿勢に維持され、また中央環状部５２に弁体３２がはまっているため、弁体３２は図５（Ａ）のＩ からＩＩに示す位置までほぼ弁座口４０の中心軸線Ｌに沿って移動する。また、自由端の板厚方向軸線Ｌと垂直な方向に移動可能に板ばね２８に弁体３２を当接させたとしても、自由端の姿勢がその板厚方向軸線Ｌに対して垂直に近い姿勢に維持されるため、弁座から離座した状態の弁体３２の中心位置が弁座口４０の中心軸線Ｌから大きくずれにくい。したがって、本実施形態の板ばね２８の場合、板ばね２８の付勢力によって弁座口４０の開口面積を正確に制御することができる。すなわち、プレッシャレギュレータ１８によってその上流のシステム圧を正確に制御することができる。
【００２７】
これに対し、図５（Ｂ）に示すように単純な片持ち梁形状の板ばね９２の場合、弁体３２に当接する自由端の傾きθは、板ばね９２に作用する力が増大すると本実施形態の板ばね２８に比べて顕著に増大する。このため、板ばね９２と弁体３２とが互いに固定されていないとすれば、弁座９４から離座した弁体３２の位置は図５（Ｂ）のＩＩ、ＩＩＩ に示すように、板ばね９２の自由端の変位と無関係に大きく変動する。また、板ばね９２と弁体３２とが互いに固定されているとすれば、弁座９４から離座した状態の弁体３２の中心位置は弁座口９６の中心軸線Ｌから大きくずれることになる。
【００２８】
以上、プレッシャレギュレータ１８の構成を説明した。次にプレッシャレギュレータ１８の作動を説明する。
図１に示す第二配管１２を通じてインジェクタ１４に供給される燃料の圧力が所定値を越えると、第三配管１６を通じてプレッシャレギュレータ１８の弁体３２に作用する燃料圧力により、弁体３２は板ばね２８の付勢力に抗って弁座３４から下流側に離座する。すると、弁体３２によって閉塞されていた弁座口４０が開放され、ハウジング３８の導入口２０及び吐出口３６が連通する。この結果、第二配管１２の燃料は第三配管１６を通じてプレッシャレギュレータ１８の導入口２０に導入され、プレッシャレギュレータ１８の吐出口３６からは板ばね２８の開口部５８、６０、６２、６４を通過した燃料が燃料タンク１０に排出される。すると、第二配管１２を通じてインジェクタ１４に供給される燃料の圧力が所定の圧力に調整される。
【００２９】
図６は弁座口４０が開放されたときの燃料流れを説明するための模式図である。本実施形態では、図６（Ａ）に示すように、弁座３４の下流側に弁体３２を設け、弁体３２を弁座３４の下流側に離座させている。したがって、弁体３２が弁座３４から離座すると、弁座口４０の内側から外側に向かって燃料が拡散するため、弁座口４０の下流で縮流が発生しない。したがって、本実施形態では、弁座口４０の下流における燃料の縮流によるベーパの発生が抑制される。この結果、騒音の発生が抑制される。
【００３０】
これに対し、図６（Ｂ）に示す従来例のように、弁座９９の上流に弁体９７を設け、弁体９７を弁座９９から上流側に離座させると、弁座口９８の外側から内側に向かって燃料が縮流するため、弁座口９８の下流で燃料の圧力がさらに低下しベーパが発生しやすい。
【００３１】
（第二実施形態）
図７は本発明による燃料圧力調整装置の第二実施形態を示す断面図である。第二実施形態による燃料圧力調整装置は、弁座口４０を閉塞する弁体としての機能を板ばね７４で実現するプレッシャレギュレータ７２である。第一実施形態と実質的に同一の部分には同一の符号を付して説明を省略する。
【００３２】
シート部材４２の環状の端面が弁座７８に相当する。
板ばね７４は、中央部７６に円形開口部が形成されていない点と、環状部４６、４８の数が異なる点を除いては第一実施形態と実質的に同一である。中央部７６は、弁座７８に着座して弁座口４０を閉塞可能な円盤形状である。
第二実施形態では、弁座口４０を閉塞する弁体としての機能を板ばね７４で実現することによりプレッシャレギュレータ７２の構成を簡素化できる。
【００３３】
（第三実施形態）
図８は本発明による燃料圧力調整装置の第三実施形態を示す断面図である。第一実施形態と実質的に同一の部分には同一の符号を付して説明を省略する。第三実施形態による燃料圧力調整装置は、円錐形状の弁体８２を備えたプレッシャレギュレータ８０である。弁体８２は、中央環状部５２の円形開口部７０に固定されている。
【００３４】
（第四実施形態）
図９は本発明による燃料圧力調整装置の第四実施形態を示す断面図である。第一実施形態と実質的に同一の部分には同一の符号を付して説明を省略する。第四実施形態による燃料圧力調整装置は、シート部材４２がハウジング２０８から突き出たプレッシャレギュレータ２０４である。燃料は、第三配管１６からシート部材４２の導入口２０６に直接導入される。また、板ばね２１２の中央部２１０に開口部が形成されていないため、板ばね２１２はその板厚方向軸線に垂直な方向に弁体３２を拘束していない。板ばね２１２によって弁体３２が弁座３４に押し付けられることにより、弁体３２は弁座３４に対して調心される。
【００３５】
（板ばねの実施形態）
本発明に係る燃料圧力調整装置の板ばねの実施形態は、図３に示した形状に限られない。以下、板ばねの複数の実施形態を説明する。他の実施形態と実質的に同一の部分には同一の符号を付して説明を省略する。
【００３６】
図１０に示す板ばね１１８は、外縁部１００及び環状部１０２、１０４、１０６が矩形の実施形態である。隣り合う外縁部１００、環状部１０２、１０４、１０６、中央部１０８は接続部１１０、１１２、１１４、１１６で連結されている。接続部１１０は、環状部１０２にとって請求項に記載の外側接続部に相当する。接続部１１６は、環状部１０２にとって請求項に記載の内側接続部に相当し、環状部１０４にとって請求項に記載の外側接続部に相当する。接続部１１２は、環状部１０４にとって請求項に記載の内側接続部に相当し、環状部１０６にとって請求項に記載の外側接続部に相当する。接続部１１４は、環状部１０６にとって請求項に記載の内側接続部に相当する。各環状部において、中央部又は内側の隣の環状部に接続している内側接続部と、外縁部又は外側の隣の環状部に接続している外側接続部とを、互いにほぼ半周離間した位置に設けているため、中央部１０８に弁体３２から力が加わると、ジグザグ形状に変形する（図４参照）。
弁体３２がはまる開口部が中央部１０８に形成されていないため、弁体３２は中央部１０８の板厚方向軸線と垂直な方向に移動可能に中央部１０８に当接する。
【００３７】
図１１に示す板ばね１２０は、隣り合う外縁部１００、環状部１０２、１０４、１０６、中央部１０８がそれぞれの一辺が重なった形で連結された実施形態である。外縁部１００と環状部１０２が重なった部位１２２は、環状部１０２にとって請求項に記載の外側接続部に相当する。環状部１０２と環状部１０４が重なった部位１２８は、環状部１０２にとって請求項に記載の内側接続部に相当し、環状部１０４にとって請求項に記載の外側接続部に相当する。環状部１０４と環状部１０６が重なった部位１２４は、環状部１０４にとって請求項に記載の内側接続部に相当し、環状部１０６にとって請求項に記載の外側接続部に相当する。環状部１０４と中央部１０８が重なった部位１２６は、環状部１０６にとって請求項に記載の内側接続部に相当する。各環状部において、中央部又は内側の隣の環状部に接続している内側接続部と、外縁部又は外側の隣の環状部に接続している外側接続部とを、互いにほぼ半周離間した位置に設けているため、中央部１０８に弁体３２から力が加わると、ジグザグ形状に変形する（図４参照）。
【００３８】
図１２、図１３、図１４、図１５、図１６に示す板ばねは、固定端の外縁部と自由端の中央部が複数のばね部で連結された実施形態である。以下に説明する実施形態においても、弁体３２がはまる開口部を自由端の中央部に形成してもよいし、弁体３２がはまる開口部を中央部に形成せずに、弁体３２が自由端の中央部の板厚方向軸線と垂直な方向に移動可能に中央部に当接する構成を採用してもよい。また、以下に説明する実施形態においても、プレッシャレギュレータの構造を簡素化するために中央部に弁座口４０を閉塞する機能をもたせてもよい。
【００３９】
図１２に示す板ばね１４６では、矩形枠形状の外縁部１３２と矩形の中央部１３６を２つのばね部１４０、１４４で連結している。ばね部１４０の基端１３８とばね部１４４の基端１３０は互いに半周離間して外縁部１３２の内縁に接続されている。ばね部１４０の先端１３４とばね部１４４の先端１４２は互いに半周離間して中央部１３６の外縁に接続されている。弁体３２に当接する中央部１３６の外縁を周方向に等間隔に２つのばね部１４０、１４４によって支持しているため、弁体３２によって中央部１３６に板厚方向の力が作用したときに、中央部１３６の姿勢を板厚方向軸線に対して垂直に近い姿勢に維持することができる。ばね部１４０、１４４は、ジグザグ形状であるため、基端から先端までの距離が長い。したがって、ばね部１４０、１４４は、体格を小さく保ちつつ、ばね定数を小さくすることができる。
【００４０】
図１３に示す板ばね１４８では、円形の外縁部１５０と円形の中央部１５４を２つのばね部１５２、１６０で連結している。ばね部１５２の基端１５８とばね部１６０の基端１６４は互いに半周離間して外縁部１５０の内縁に接続されている。ばね部１５２の先端１５６とばね部１６０の先端１６２は互いに半周離間して中央部１５４の外縁に接続されている。
【００４１】
図１４に示す板ばね１６６では、円形の外縁部１５０と円形の中央部１５４を３つのばね部１６８、１７０、１７２で連結している。弁体３２に当接する中央部１５４の外縁を周方向に等間隔に３つのばね部１６８、１７０、１７２によって支持しているため、弁体３２によって中央部１５４に板厚方向の力が作用したときに、中央部１５４の姿勢を板厚方向軸線に対して垂直に近い姿勢に維持することができる。ばね部１６８、１７０、１７２は、ジグザグ形状であるため、基端から先端までの距離が長い。したがって、ばね部１６８、１７０、１７２は、体格を小さく保ちつつ、ばね定数を小さくすることができる。
【００４２】
図１５に示す板ばね１７４では、円形の外縁部１５０と円形の中央部１５４を２つのばね部１７６、１８４で連結している。ばね部１７６、１８４は、それぞれ先端１８０、１８６から基端１８２、１８８に向かって幅が拡がっている。このため、ばね部１７６、１８４は、それぞれ先端１８０、１８６から基端１８２、１８８に向かって剛性が高くなっている。
【００４３】
図１６に示す板ばね１９０では、円形の外縁部１５０と円形の中央部１５４を２つのばね部１９２、１９８で連結している。ばね部１９２、１９８は、渦巻き形状であるため、基端１９６、２０２から先端２００、１９４までの距離が長い。したがって、ばね１９２、１９８は、体格を小さく保ちつつ、ばね定数を小さくすることができる。また、ばね部１９２、１９８は、それぞれ先端２００、１９４から基端１９６、２０２に向かって幅が拡がっている。このため、ばね部１９２、１９８は、それぞれ先端２００、１９４から基端１９６、２０２に向かって剛性が高くなっている。
【００４４】
【図面の簡単な説明】
【図１】本発明による燃料圧力調整装置の第一実施形態を示す模式図である。
【図２】本発明による燃料圧力調整装置の第一実施形態を示す断面図である。
【図３】本発明の第一実施形態に係る板ばねを示す平面図である。
【図４】本発明の第一実施形態に係る板ばねを示す側面図である。
【図５】本発明の第一実施形態において、板ばねの自由端の姿勢と弁座口の開口面積の関係を説明するための模式図である。
【図６】本発明の第一実施形態において、弁座口が開放されたときの燃料流れを説明するための模式図である。
【図７】本発明による燃料圧力調整装置の第二実施形態を示す断面図である。
【図８】本発明による燃料圧力調整装置の第三実施形態を示す断面図である。
【図９】本発明による燃料圧力調整装置の第四実施形態を示す断面図である。
【図１０】本発明に係る板ばねの実施形態を示す平面図である。
【図１１】本発明に係る板ばねの実施形態を示す平面図である。
【図１２】本発明に係る板ばねの実施形態を示す平面図である。
【図１３】本発明に係る板ばねの実施形態を示す平面図である。
【図１４】本発明に係る板ばねの実施形態を示す平面図である。
【図１５】本発明に係る板ばねの実施形態を示す平面図である。
【図１６】本発明に係る板ばねの実施形態を示す平面図である。
【符号の説明】
１０ 燃料タンク
１８ プレッシャレギュレータ（燃料圧力調整装置）
２６ 燃料ポンプ
２８ 板ばね
３２ 弁体
３４ 弁座
４０ 弁座口
４２ シート部材
４４ 外縁環状部（外縁部）
４６、４８、５０ 環状部
５２ 中央環状部（中央部）
５４、５６、６６、６８ 接続部
１４０、１４４ ばね部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an internal combustion engine (hereinafter, referred to as an engine) by a fuel pump to a predetermined pressure.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an engine by a fuel pump to a predetermined system pressure is known (for example, see Patent Documents 1 and 2). In the fuel pressure adjusting devices disclosed in Patent Literatures 1 and 2, a valve element is provided upstream of a valve seat port, and the valve element is separated from the valve seat upstream by pressure acting on the diaphragm. Recirculate the fuel to the fuel tank.
[0003]
[Patent Document 1]
WO 96/14506 pamphlet
[Patent Document 2]
JP-A-2000-45897
[0004]
[Problems to be solved by the invention]
In the fuel pressure adjusting devices disclosed in Patent Literatures 1 and 2, when the valve element is separated from the valve seat and the valve seat opening is opened, the fuel pressure rapidly drops from the system pressure to the pressure in the fuel tank. At the same time, the pressure of the fuel further decreases due to the contraction of the fuel from the outside of the valve seat toward the inside of the valve seat, and vapor is generated in the fuel. When the fuel containing vapor generated in this way is ejected from the fuel pressure adjusting device as a jet into the fuel tank, fluctuations in the pressure of the jet propagate in the fuel and members that collide with the jet vibrate. Noise.
The present invention has been made to solve this problem, and an object of the present invention is to provide a fuel pressure adjusting device that reduces noise generation.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, by providing the valve element that closes the valve seat at the downstream side of the valve seat, when the valve element separates from the valve seat, the fuel flows from inside to outside of the valve seat. To suppress the generation of vapor due to the contraction of fuel downstream of the valve seat. Further, the size can be reduced by adopting a plate-shaped leaf spring as a means for urging the valve body in the direction of seating on the valve seat. Further, by configuring the leaf spring as follows, the opening area of the valve seat can be accurately controlled by the urging force of the leaf spring. That is, the free end in contact with the valve body is configured to maintain a posture nearly perpendicular to the axis in the thickness direction. Specifically, the outer edge of the leaf spring is a fixed end, and the center of the leaf spring is a free end that abuts on the valve body. At least one annular portion is provided between the outer edge and the free end. Further, in the annular portion, the inner connecting portion connected to the central portion or the inner adjacent annular portion and the outer connecting portion connected to the outer edge portion or the outer adjacent annular portion are separated from each other by approximately half a circle. It is provided in the position where it was done. In addition, the inside connection part of the outer ring part in two adjacent ring parts corresponds to the outside connection part of the inner ring part. When a force in the thickness direction of the leaf spring is applied to the central portion, the leaf spring having such a configuration is elastically deformed into a three-dimensional shape that zigzags at the inner connection portion and the outer connection portion (see, for example, FIG. 4). At this time, an angle (corresponding to θ1 to θ4 in the example of FIG. 4) formed by two elements (an outer edge, an annular portion, or a center) sandwiching the inner connection portion or the outer connection portion is set to θn (n = 1, 2). .. K), the angle θ between the outer edge and the center (corresponding to θ5 in the example of FIG. 4) is approximated by the following equation (1).
(Equation 1)

[0006]
The above equation (1) indicates that the configuration of the leaf spring can suppress an increase in the angle θ between the outer edge portion and the central portion with an increase in the displacement of the central portion. That is, in the fuel pressure adjusting device according to the first aspect, since the posture of the central portion in contact with the valve body can be maintained at a posture substantially perpendicular to the plate thickness direction axis, the opening area of the valve seat opening is reduced. It can be controlled accurately by the biasing force of the leaf spring. As a result, the system pressure upstream of the valve seat can be adjusted accurately.
[0007]
According to the second aspect of the present invention, the valve seat is urged in the valve seat direction by contacting the valve body with the central portion so as to be movable in a direction substantially perpendicular to the plate thickness direction axis at the central portion. The valve element is automatically centered according to the shape. Thus, the valve seat can be reliably closed when the valve is closed.
[0008]
According to the third aspect of the present invention, the configuration is simplified by integrating the central portion and the valve body according to the first aspect.
According to the fourth aspect of the present invention, by making the rigidity of the outer annular portion of the two adjacent annular portions higher than the rigidity of the inner annular portion, it is possible to make the distortion generated in each annular portion more uniform.
[0009]
According to the fifth aspect of the present invention, by providing the valve element that closes the valve seat at the downstream side of the valve seat, when the valve element separates from the valve seat, the fuel flows from the inside of the valve seat to the outside. To suppress the generation of vapor due to the contraction of fuel downstream of the valve seat. Further, the size can be reduced by adopting a plate-shaped leaf spring as a means for urging the valve body in the direction of seating on the valve seat. Further, by configuring the leaf spring as follows, the opening area of the valve seat can be accurately controlled by the urging force of the leaf spring. That is, the free end in contact with the valve body is configured to maintain a posture nearly perpendicular to the axis in the thickness direction. Specifically, the outer edge of the leaf spring is a fixed end, and the center of the leaf spring is a free end that abuts on the valve body. Further, the distal ends of at least two spring portions whose base ends are connected to the outer edge are connected to the outer edge of the central portion at equal intervals in the circumferential direction. Further, by supporting the outer edge of the central portion abutting on the valve body at equal intervals in the circumferential direction by a plurality of spring portions, the attitude of the central portion can be maintained at a position nearly perpendicular to the plate thickness direction axis. . Therefore, in the fuel pressure adjusting device according to the fifth aspect, the opening area of the valve seat can be accurately controlled by the urging force of the leaf spring. As a result, the system pressure upstream of the valve seat can be adjusted accurately.
[0010]
In the invention according to claim 6, the valve seat is biased in the valve seat direction by contacting the valve body with the central portion so as to be movable in a direction substantially perpendicular to the plate thickness direction axis at the central portion. The valve element is automatically centered according to the shape. Thus, the valve seat can be reliably closed when the valve is closed.
[0011]
In the invention described in claim 7, the configuration is simplified by integrating the central portion described in claim 5 and the valve element.
According to the eighth aspect of the invention, by forming the spring portion in a zigzag shape, the distance from the base end to the distal end of the spring portion can be increased. As a result, a small leaf spring having a small spring constant can be realized.
[0012]
According to the ninth aspect of the invention, by forming the spring portion into a spiral shape, the distance from the base end to the distal end of the spring portion can be increased. As a result, a small leaf spring having a small spring constant can be realized.
According to the tenth aspect of the present invention, by increasing the rigidity from the distal end to the proximal end of the spring portion, the distortion generated from the distal end to the proximal end of the spring portion can be made uniform.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing a first embodiment of a fuel pressure adjusting device according to the present invention. The pressure regulator 18 as a fuel pressure adjusting device is a device that adjusts the fuel supplied from the fuel tank 10 of the vehicle to the injector 14 of the engine by the fuel pump 26 to a predetermined system pressure.
[0014]
The in-tank type fuel pump 26 is housed in the fuel tank 10. A suction filter 30 is connected to a fuel inlet of the fuel pump 26. The fuel outlet of the fuel pump 26 is connected to the fuel filter 22. The fuel pump 26 sucks the fuel in the fuel tank 10 through the suction filter 30 and supplies the pressurized fuel to the injector 14 through the fuel filter 22.
[0015]
The pressure regulator 18 is connected to a third pipe 16 branched from the second pipe 12 for supplying the fuel discharged from the fuel filter 22 to the injector 14. The pressure regulator 18 includes a housing 38, a seat member 42, a valve body 32, and a leaf spring 28.
[0016]
FIG. 2 is a sectional view showing a first embodiment of the fuel pressure adjusting device according to the present invention.
The housing 38 is a cylindrical metal member having the inlet 20 connected to the third pipe 16 and the outlet 36 communicating with the inside of the fuel tank 10. Fuel is introduced into the inlet 20 from the second pipe 12 through the third pipe 16.
[0017]
The sheet member 42 is a cylindrical metal member, and is fixed to the inner wall of the housing 38 by press fitting or the like. The inner wall 24 of the seat member 42 forms a fuel flow path, and the inner edge of the downstream end surface of the seat member 42 forms an annular valve seat 34. The opening formed inside the valve seat 34 constitutes a valve seat opening 40. When the valve seat port 40 is opened, the introduction port 20 of the housing 38 and the discharge port 36 communicate with each other.
[0018]
The valve body 32 is a spherical metal member and is housed in the housing 38, is located on the discharge port side of the seat member 42 in the housing 38, and is restricted by the leaf spring 28 in the internal space of the housing 38. The valve body 32 is set to a size that closes the valve seat port 40 when seated on the valve seat 34. The valve element 32 is fitted in the circular opening 70 of the leaf spring 28.
[0019]
The leaf spring 28 is provided at a discharge port 36 of the housing 38. The leaf spring 28 is crimped to the discharge port side end 39 of the housing 38 in the posture perpendicular to the central axis of the valve seat port 40. The leaf spring 28 urges the valve body 32 in a direction of sitting on the valve seat 34. The axis in the thickness direction of the free end of the leaf spring 28 coincides with the central axis of the valve seat 40. The axial length of the pressure regulator 18 can be shortened by using a flat spring as a means for urging the valve body 32 in the direction of sitting on the valve seat 34. By using a leaf spring having a through hole as means for restraining the valve body 32 in the housing 38, the axial length of the pressure regulator 18 can be shortened, and the configuration of the pressure regulator 18 can be simplified. Can be. As a means for fixing the leaf spring 28 to the housing 38, a screw or the like may be used. However, the structure of the pressure regulator 18 can be simplified by caulking and the shaft length can be shortened.
[0020]
FIG. 3 is a plan view showing the leaf spring 28 according to the first embodiment of the present invention. The leaf spring 28 is a flat spring having a circular outer edge. The leaf spring 28 includes a plurality of annular portions 44, 46, 48, 50, 52 arranged concentrically, and connecting portions 54, 56, 66, 68 for connecting two adjacent annular portions. The width and plate thickness of each annular portion may be the same, or the outer annular portion may be increased in width or plate thickness to increase rigidity. The leaf spring 28 has a plurality of C-shaped openings 58, 60, 62, and 64 formed concentrically, and a circular opening 70 at the center.
[0021]
The outermost annular portion 44 (hereinafter, referred to as an outer edge annular portion 44) corresponds to an outer edge portion described in claims. The innermost annular portion 52 (hereinafter, referred to as a central annular portion 52) corresponds to a central portion described in claims. The other annular portions 46, 48, 50 correspond to the annular portions described in the claims. The connecting portion 68 corresponds to an outer connecting portion described in claims for the annular portion 46. The connecting portion 54 corresponds to an inner connecting portion described in claims for the annular portion 46 and corresponds to an outer connecting portion described in claims for the annular portion 48. The connecting portion 66 corresponds to the inner connecting portion described in the claims for the annular portion 48, and corresponds to the outer connecting portion described in the claims for the annular portion 50. The connecting portion 56 corresponds to an inner connecting portion described in claims for the annular portion 50.
[0022]
The central annular portion 52 is a free end that is displaced in the thickness direction of the leaf spring 28 (in the direction perpendicular to the paper surface of FIG. 3) when the force is received in that direction. Since the valve element 32 fits into the circular opening 70 formed inside the central annular section 52, the valve element 32 is oriented in a direction perpendicular to the plate thickness direction axis of the central annular section 52 (the direction parallel to the plane of FIG. 3). ) Do not move. The outer edge annular portion 44 is a fixed end fixed to the housing 38 in a posture perpendicular to the central axis of the valve seat 40.
[0023]
In the pressure regulator 18 having the valve body 32 provided downstream of the valve seat 40, the area where the pressure of the fuel for opening the valve seat 40 acts is only the surface area of the valve body 32 closing the valve seat 40. . For this reason, in the pressure regulator 18 provided with the valve element 32 downstream of the valve seat 40, the leaf spring 28 is controlled so that the change in the control pressure with respect to the fuel flow rate (pressure gradient ΔP (see the following equation (2))) is reduced. It is desirable to set a small spring constant of. In the present embodiment, a small leaf spring having a small spring constant is formed by connecting a plurality of annular portions 44, 46, 48, 50, and 52 concentrically, instead of a simple cantilever shape. 28 are realized.
ΔP = kx / S Equation (2)
(K: spring constant, x: valve lift, S: effective pressure receiving area)
[0024]
When the central annular portion 52 receives a force from the valve body 32 in the thickness direction of the leaf spring 28, the leaf spring 28 is elastically deformed as shown in FIG. The inclination θ5 of the center annular portion 52 with respect to the outer edge annular portion 44 is approximated by the following equation (3).
θ5 = (θ2−θ1) + (θ4−θ3) Equation (3)
[0025]
When the force acting on the central annular portion 52 increases, θ1 to θ4 respectively increase, but the increment of θ5 is considerably smaller than the increment of the sum of θ1 to θ4. That is, since the inner connecting portion and the outer connecting portion are provided at half-circle intervals in each annular portion so that the leaf spring deforms from a flat plate shape to a zigzag shape, the outer edge annular portion is increased with an increase in the force acting on the central annular portion. An increase in the inclination θ5 of the central annular portion 52 with respect to the portion 44 is suppressed. As a result, the posture of the central annular portion 52 abutting on the valve body 32 can be maintained at a posture nearly perpendicular to the axis in the plate thickness direction.
[0026]
FIG. 5 is a schematic diagram for explaining the relationship between the position of the free end of the leaf spring that contacts the valve body 32 and the opening area of the valve seat 40. In the case of the leaf spring 28 of the present embodiment, the posture of the central annular portion 52 abutting on the valve body 32 is maintained at a posture nearly perpendicular to the plate thickness direction axis L, and the valve body 32 is attached to the central annular portion 52. Since it is fitted, the valve element 32 moves substantially along the central axis L of the valve seat 40 from the position I to the position II in FIG. Further, even if the valve body 32 is brought into contact with the leaf spring 28 so as to be movable in a direction perpendicular to the plate thickness direction axis L of the free end, the posture of the free end is almost perpendicular to the plate thickness direction axis L. Since the posture is maintained, the center position of the valve body 32 in a state of being separated from the valve seat is unlikely to be largely shifted from the center axis L of the valve seat opening 40. Therefore, in the case of the leaf spring 28 of the present embodiment, the opening area of the valve seat 40 can be accurately controlled by the urging force of the leaf spring 28. That is, the system pressure upstream of the pressure regulator 18 can be accurately controlled.
[0027]
On the other hand, as shown in FIG. 5B, in the case of a leaf spring 92 having a simple cantilever shape, the inclination θ of the free end that abuts on the valve body 32 becomes smaller when the force acting on the leaf spring 92 increases. It is significantly increased as compared with the leaf spring 28 of the embodiment. For this reason, assuming that the leaf spring 92 and the valve body 32 are not fixed to each other, the position of the valve body 32 separated from the valve seat 94 is changed to the leaf spring as shown in II and III in FIG. It fluctuates greatly irrespective of the displacement of the 92 free end. Further, if the leaf spring 92 and the valve body 32 are fixed to each other, the center position of the valve body 32 in a state of being separated from the valve seat 94 is greatly shifted from the center axis L of the valve seat opening 96. .
[0028]
The configuration of the pressure regulator 18 has been described above. Next, the operation of the pressure regulator 18 will be described.
When the pressure of the fuel supplied to the injector 14 through the second pipe 12 shown in FIG. 1 exceeds a predetermined value, the fuel pressure acting on the valve body 32 of the pressure regulator 18 through the third pipe 16 causes the valve body 32 to It is separated from the valve seat 34 on the downstream side against the urging force of 28. Then, the valve seat port 40 closed by the valve body 32 is opened, and the introduction port 20 and the discharge port 36 of the housing 38 communicate with each other. As a result, the fuel in the second pipe 12 is introduced into the inlet 20 of the pressure regulator 18 through the third pipe 16, and passes through the openings 58, 60, 62, 64 of the leaf spring 28 from the discharge port 36 of the pressure regulator 18. The discharged fuel is discharged to the fuel tank 10. Then, the pressure of the fuel supplied to the injector 14 through the second pipe 12 is adjusted to a predetermined pressure.
[0029]
FIG. 6 is a schematic diagram for explaining the fuel flow when the valve seat port 40 is opened. In this embodiment, as shown in FIG. 6A, the valve element 32 is provided downstream of the valve seat 34, and the valve element 32 is separated from the valve seat 34 downstream. Therefore, when the valve element 32 is separated from the valve seat 34, fuel diffuses from the inside to the outside of the valve seat port 40, so that no flow contraction occurs downstream of the valve seat port 40. Therefore, in this embodiment, the generation of vapor due to the contraction of fuel downstream of the valve seat 40 is suppressed. As a result, generation of noise is suppressed.
[0030]
On the other hand, as in the conventional example shown in FIG. 6B, when the valve body 97 is provided upstream of the valve seat 99 and the valve body 97 is separated from the valve seat 99 to the upstream side, the valve seat opening 98 is closed. Since the fuel contracts from the outside to the inside, the pressure of the fuel further decreases downstream of the valve seat port 98, and vapor is likely to be generated.
[0031]
(Second embodiment)
FIG. 7 is a sectional view showing a second embodiment of the fuel pressure adjusting device according to the present invention. The fuel pressure adjusting device according to the second embodiment is a pressure regulator 72 that realizes a function as a valve body that closes the valve seat port 40 with a leaf spring 74. Parts that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
[0032]
The annular end face of the seat member 42 corresponds to the valve seat 78.
The leaf spring 74 is substantially the same as the first embodiment except that the circular opening is not formed in the central portion 76 and the number of the annular portions 46 and 48 is different. The central portion 76 has a disk shape capable of sitting on the valve seat 78 and closing the valve seat opening 40.
In the second embodiment, the configuration of the pressure regulator 72 can be simplified by realizing the function as a valve body for closing the valve seat port 40 with the leaf spring 74.
[0033]
(Third embodiment)
FIG. 8 is a sectional view showing a third embodiment of the fuel pressure adjusting device according to the present invention. Parts that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. The fuel pressure adjusting device according to the third embodiment is a pressure regulator 80 including a conical valve element 82. The valve body 82 is fixed to the circular opening 70 of the central annular portion 52.
[0034]
(Fourth embodiment)
FIG. 9 is a sectional view showing a fourth embodiment of the fuel pressure adjusting device according to the present invention. Parts that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. The fuel pressure adjusting device according to the fourth embodiment is a pressure regulator 204 in which the seat member 42 protrudes from the housing 208. The fuel is introduced directly from the third pipe 16 into the inlet 206 of the sheet member 42. In addition, since no opening is formed in the central portion 210 of the leaf spring 212, the leaf spring 212 does not restrain the valve body 32 in a direction perpendicular to the plate thickness direction axis. When the valve element 32 is pressed against the valve seat 34 by the leaf spring 212, the valve element 32 is aligned with the valve seat 34.
[0035]
(Embodiment of leaf spring)
The embodiment of the leaf spring of the fuel pressure adjusting device according to the present invention is not limited to the shape shown in FIG. Hereinafter, a plurality of embodiments of the leaf spring will be described. Parts that are substantially the same as in the other embodiments are given the same reference numerals, and descriptions thereof are omitted.
[0036]
The leaf spring 118 shown in FIG. 10 is an embodiment in which the outer edge portion 100 and the annular portions 102, 104, and 106 are rectangular. The adjacent outer edge portion 100, annular portions 102, 104, 106, and central portion 108 are connected by connecting portions 110, 112, 114, 116. The connecting portion 110 corresponds to an outer connecting portion described in claims for the annular portion 102. The connecting portion 116 corresponds to the inner connecting portion described in the claims for the annular portion 102, and corresponds to the outer connecting portion described in the claims for the annular portion 104. The connecting portion 112 corresponds to the inner connecting portion described in the claims for the annular portion 104, and corresponds to the outer connecting portion described in the claims for the annular portion 106. The connection portion 114 corresponds to an inner connection portion described in claims for the annular portion 106. In each of the annular portions, a position where the inner connecting portion connected to the central portion or the inner adjacent annular portion and the outer connecting portion connected to the outer edge portion or the outer adjacent annular portion are substantially half-peripherally separated from each other. Therefore, when a force is applied to the central portion 108 from the valve body 32, the central portion 108 is deformed into a zigzag shape (see FIG. 4).
Since the opening in which the valve element 32 fits is not formed in the central part 108, the valve element 32 abuts on the central part 108 so as to be movable in a direction perpendicular to the plate thickness direction axis of the central part 108.
[0037]
A leaf spring 120 shown in FIG. 11 is an embodiment in which adjacent outer edge portions 100, annular portions 102, 104, 106, and a central portion 108 are connected such that one side thereof is overlapped. The portion 122 where the outer edge portion 100 and the annular portion 102 overlap with each other corresponds to an outer connecting portion described in claims for the annular portion 102. A portion 128 where the annular portion 102 and the annular portion 104 overlap each other corresponds to the inner connecting portion described in the claims for the annular portion 102 and corresponds to the outer connecting portion described in the claims for the annular portion 104. A portion 124 where the annular portion 104 and the annular portion 106 overlap each other corresponds to the inner connecting portion described in the claims for the annular portion 104 and corresponds to the outer connecting portion described in the claims for the annular portion 106. The portion 126 where the annular portion 104 and the central portion 108 overlap with each other corresponds to an inner connecting portion described in claims for the annular portion 106. In each annular portion, a position where the inner connecting portion connected to the central portion or the inner adjacent annular portion and the outer connecting portion connected to the outer edge portion or the outer adjacent annular portion are substantially half-circumferentially separated from each other. Therefore, when a force is applied to the central portion 108 from the valve body 32, the central portion 108 is deformed into a zigzag shape (see FIG. 4).
[0038]
The leaf springs shown in FIGS. 12, 13, 14, 15, and 16 are embodiments in which the outer edge of the fixed end and the center of the free end are connected by a plurality of spring portions. Also in the embodiment described below, the opening in which the valve body 32 fits may be formed in the center of the free end, or the valve body 32 may be formed without forming the opening in which the valve body 32 fits in the center. A configuration in which the free end is in contact with the central portion movably in the direction perpendicular to the plate thickness direction axis at the central portion may be employed. Also, in the embodiment described below, a function of closing the valve seat port 40 may be provided at the center in order to simplify the structure of the pressure regulator.
[0039]
In a leaf spring 146 shown in FIG. 12, a rectangular frame-shaped outer edge portion 132 and a rectangular central portion 136 are connected by two spring portions 140 and 144. The proximal end 138 of the spring portion 140 and the proximal end 130 of the spring portion 144 are connected to the inner edge of the outer edge portion 132 while being separated from each other by a half circumference. The distal end 134 of the spring portion 140 and the distal end 142 of the spring portion 144 are connected to the outer edge of the central portion 136 at a half-periphery from each other. Since the outer edge of the central portion 136 that contacts the valve body 32 is supported at equal intervals in the circumferential direction by the two spring portions 140 and 144, when a force in the plate thickness direction acts on the central portion 136 by the valve body 32. , The posture of the central portion 136 can be maintained close to perpendicular to the thickness direction axis. Since the spring portions 140 and 144 have a zigzag shape, the distance from the proximal end to the distal end is long. Therefore, the spring portions 140 and 144 can reduce the spring constant while keeping the physique small.
[0040]
In a leaf spring 148 shown in FIG. 13, a circular outer edge 150 and a circular center 154 are connected by two springs 152 and 160. The proximal end 158 of the spring portion 152 and the proximal end 164 of the spring portion 160 are connected to the inner edge of the outer edge portion 150 while being separated from each other by a half circumference. The distal end 156 of the spring portion 152 and the distal end 162 of the spring portion 160 are connected to the outer edge of the central portion 154 while being separated from each other by a half circumference.
[0041]
In the leaf spring 166 shown in FIG. 14, the circular outer edge 150 and the circular center 154 are connected by three springs 168, 170, and 172. Since the outer edge of the central portion 154 abutting on the valve body 32 is supported at equal intervals in the circumferential direction by the three spring portions 168, 170, and 172, a force in the thickness direction acts on the central portion 154 by the valve body 32. At this time, the posture of the central portion 154 can be maintained at a posture nearly perpendicular to the plate thickness direction axis. Since the spring portions 168, 170, and 172 have a zigzag shape, the distance from the proximal end to the distal end is long. Therefore, the spring portions 168, 170, and 172 can reduce the spring constant while keeping the physical size small.
[0042]
In the leaf spring 174 shown in FIG. 15, the circular outer edge 150 and the circular center 154 are connected by two springs 176 and 184. The width of the spring portions 176 and 184 increases from the distal ends 180 and 186 toward the proximal ends 182 and 188, respectively. Therefore, the rigidity of the spring portions 176 and 184 increases from the distal ends 180 and 186 toward the proximal ends 182 and 188, respectively.
[0043]
In a leaf spring 190 shown in FIG. 16, a circular outer edge 150 and a circular center 154 are connected by two springs 192 and 198. Since the spring portions 192 and 198 have a spiral shape, the distance from the proximal ends 196 and 202 to the distal ends 200 and 194 is long. Therefore, the springs 192 and 198 can reduce the spring constant while keeping the physical size small. The width of the spring portions 192 and 198 increases from the distal ends 200 and 194 to the proximal ends 196 and 202, respectively. For this reason, the rigidity of the spring portions 192 and 198 increases from the distal ends 200 and 194 toward the proximal ends 196 and 202, respectively.
[0044]
[Brief description of the drawings]
FIG. 1 is a schematic view showing a first embodiment of a fuel pressure adjusting device according to the present invention.
FIG. 2 is a sectional view showing a first embodiment of a fuel pressure adjusting device according to the present invention.
FIG. 3 is a plan view showing a leaf spring according to the first embodiment of the present invention.
FIG. 4 is a side view showing a leaf spring according to the first embodiment of the present invention.
FIG. 5 is a schematic diagram for explaining a relationship between a posture of a free end of a leaf spring and an opening area of a valve seat in the first embodiment of the present invention.
FIG. 6 is a schematic view for explaining a fuel flow when a valve seat is opened in the first embodiment of the present invention.
FIG. 7 is a sectional view showing a second embodiment of the fuel pressure adjusting device according to the present invention.
FIG. 8 is a sectional view showing a third embodiment of the fuel pressure adjusting device according to the present invention.
FIG. 9 is a sectional view showing a fourth embodiment of the fuel pressure adjusting device according to the present invention.
FIG. 10 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 11 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 12 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 13 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 14 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 15 is a plan view showing an embodiment of a leaf spring according to the present invention.
FIG. 16 is a plan view showing an embodiment of a leaf spring according to the present invention.
[Explanation of symbols]
10 Fuel tank
18 Pressure regulator (fuel pressure regulator)
26 Fuel pump
28 leaf spring
32 valve body
34 valve seat
40 valve seat
42 sheet member
44 Outer edge ring (outer edge)
46, 48, 50 Annular part
52 center annular part (central part)
54, 56, 66, 68 connection
140, 144 spring part

Claims (10)

A fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an internal combustion engine by a fuel pump to a predetermined pressure,
A seat member having a valve seat opening to a pipe for supplying fuel from the fuel pump to the internal combustion engine and a valve seat formed around the valve seat opening;
A valve body provided on the downstream side of the valve seat and closing the valve seat opening by sitting on the valve seat,
A plate-shaped leaf spring that urges the valve body in a direction to be seated on the valve seat,
The leaf spring has an outer edge portion of a fixed end, a central portion of a free end that contacts the valve body, and at least one annular portion provided between the outer edge portion and the central portion,
The annular portion is provided at a position substantially half-circumferentially from the inner connecting portion and the inner connecting portion connected to the central portion or the inner adjacent annular portion, and is provided at the outer edge portion or the outer adjacent annular portion. A fuel pressure regulating device having an outer connecting portion connected thereto. 2. The fuel pressure adjusting device according to claim 1, wherein the valve body is in contact with the central portion so as to be movable in a direction substantially perpendicular to an axis of the central portion in a thickness direction. 3. A fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an internal combustion engine by a fuel pump to a predetermined pressure,
A seat member having a valve seat opening to a pipe for supplying fuel from the fuel pump to the internal combustion engine and a valve seat formed around the valve seat opening;
Provided on the downstream side of the valve seat, an outer edge portion of a fixed end, a central portion of a free end that closes the valve seat opening by sitting on the valve seat, and between the outer edge portion and the central portion. At least one annular portion provided, wherein the inner connecting portion is connected to the central portion or the inner adjacent annular portion, and the outer edge portion or the outer edge portion is provided at a position substantially half a circle away from the inner connecting portion. A plate-shaped leaf spring having an annular portion having an outer connecting portion connected to an adjacent annular portion,
A fuel pressure adjusting device comprising: The annular portion is provided at least two,
4. The fuel pressure adjusting device according to claim 1, wherein an outer annular portion of two adjacent annular portions has higher rigidity than an inner annular portion of the two annular portions. 5. A fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an internal combustion engine by a fuel pump to a predetermined pressure,
A seat member having a valve seat opening to a pipe for supplying fuel from the fuel pump to the internal combustion engine and a valve seat formed around the valve seat opening;
A valve body provided on the downstream side of the valve seat to close the valve seat opening by sitting on the valve seat;
A plate-shaped leaf spring that urges the valve body in a direction to be seated on the valve seat,
The leaf spring includes an outer edge portion of a fixed end, a central portion of a free end abutting on the valve body, and at least two spring portions having a proximal end connected to the outer edge portion and a distal end connected to the central portion. And a tip of each of the spring portions is connected to an outer edge of the central portion at equal intervals in a circumferential direction. 6. The fuel pressure adjusting device according to claim 5, wherein the valve body abuts on the central portion so as to be movable in a direction substantially perpendicular to an axis of the central portion in a thickness direction. A fuel pressure adjusting device that adjusts fuel supplied from a fuel tank to an internal combustion engine by a fuel pump to a predetermined pressure,
A seat member having a valve seat opening to a pipe for supplying fuel from the fuel pump to the internal combustion engine and a valve seat formed around the valve seat opening;
Provided on the downstream side of the valve seat, the outer edge of the fixed end, the center of the free end that closes the valve seat opening by sitting on the valve seat, the base end is connected to the outer edge and the tip is A plate-shaped leaf spring having at least two spring portions connected to the central portion, and a tip end of each of the spring portions connected to an outer edge of the central portion at equal intervals in a circumferential direction. A fuel pressure adjusting device characterized by the above-mentioned. The fuel pressure control device according to claim 5, wherein the spring portion has a zigzag shape. The fuel pressure control device according to claim 5, 6 or 7, wherein the spring portion has a spiral shape. The fuel pressure control device according to any one of claims 5 to 9, wherein rigidity of the spring portion increases from a distal end toward a proximal end.

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