JP3728636B2

JP3728636B2 - Negative pressure fuel valve

Info

Publication number: JP3728636B2
Application number: JP01586597A
Authority: JP
Inventors: 裕司内藤
Original assignee: Keihin Corp
Current assignee: Astemo Ltd
Priority date: 1997-01-13
Filing date: 1997-01-13
Publication date: 2005-12-21
Anticipated expiration: 2017-01-13
Also published as: JPH10196812A

Description

【０００１】
【産業上の利用分野】
本発明は、負圧室内へ導入される負圧に応じて移動するダイヤフラムによって、流路を開閉する負圧式燃料弁に関するもので、この負圧式燃料弁は、自動二輪車等の内燃機関に搭載される気化器への燃料流路に配置され、機関の運転によって生起する負圧によって燃料弁を自動的に開放し、燃料タンク内の燃料を自動的に気化器へ供給する自動燃料弁として用いられる。
【０００２】
【従来の技術】
従来の負圧式燃料弁は、図１０に示される。１は弁本体であって以下により形成される。１Ａは、弁本体１の他側Ｂ（図において左側）に形成される平端面１Ｂから一側Ａ（図において右側）に向かって凹設される燃料室であり、この燃料室１Ａの中央底部には、燃料流入路１Ｃに連なる燃料弁座１Ｄが開口して形成される。また、燃料室１Ａから下側方に向かって燃料流出路１Ｅが開口する。この状態で燃料室１Ａは、いまだ平坦面１Ｂに開口する。前記、燃料流入路１Ｃは、例えば、燃料タンク（図示せず）に接続され、燃料流出路１Ｅは、例えば気化器の燃料導入路（図示せず）に接続される。
【０００３】
２は、大気室本体であって以下により形成される。大気室本体２には、その他側Ｂに他側平端面２Ａが形成され、一側Ａに一側平坦面２Ｂが形成されるとともに他側平坦面２Ａから一側平坦面２Ｂに向けて大気室２Ｃが貫通して形成される。この状態で大気室２Ｃはいまだその両端が開口する。そして、大気室２Ｃから外側方に向けて大気開放路２Ｄが穿設される。
【０００４】
３は、負圧室本体であって以下により形成される。負圧室本体３には、その一側Ａに、平坦面３Ａが形成され、この平坦面３Ａから他側Ｂに向けて負圧室３Ｂが凹設され、さらに負圧室３Ｂから外側方に向けて負圧導入路３Ｃが穿設される。この状態で負圧室３Ｂは、いまだ平坦面３Ａに開口する。
【０００５】
Ｄｆはダイヤフラムアッセンブリーであって、図１１に示される。ダイヤフラムアッセンブリーＤｆは主に、燃料ダイヤフラム４、負圧ダイヤフラム５、リテーナ６とによって構成される。燃料ダイヤフラム４はゴム材料よりなり、以下によって形成される。４Ａは、傘状をなす薄膜である、薄膜４Ａの中央部の一側面から一側Ａに向けて弁部４Ｂが突出して形成される。又、薄膜４Ａの中央部の他側面から他側Ｂに向けて第１係止突部４Ｃが突出して形成される。この第１係止突部４Ｃは、薄膜４Ａの他側面から外径Ｅを有する小径突部４Ｄが他側Ｂに向かってのび、次いで小径突部４Ｄの外径Ｅより大なる外径Ｆを有する大径突部４Ｅが更に他側Ｂに向かって形成される。そして、前記小径突部４Ｄと大径突部４Ｅとの連接部には環状面をなす第１環状係止面部４Ｆが形成される。
【０００６】
負圧ダイヤフラム５はゴム材料よりなり以下によって形成される。５Ａは円板状をなす薄膜である。薄膜５Ａの中央部の一側面から一側Ａに向けて第２係止突部５Ｂが形成される。この第２係止突部５Ｂは、薄膜５Ａの一側面から外径Ｅを有する小径突部５Ｃが一側Ａに向かってのび、次いで小径突部５Ｃの外径Ｅより大なる外径Ｆを有する大径突部５Ｄが更に一側Ａに向かって形成される。そして、前記小径突部５Ｃと大径突部５Ｄとの連接部には環状面をなす第２環状係止面部５Ｅが形成される。尚、５Ｆは、薄膜５Ａの他側面から他側Ｂに突出して形成されたプレート嵌合溝であり、皿状のプレート７が嵌合配置される。
【０００７】
リテーナ６は例えばアルミニウム、合成樹脂等の剛性材料よりなり、以下によって形成される。リテーナ６は円柱形状をなし、その中心部分の内方に、第１係止突部４Ｃ、第２係止突部５Ｂの大径突部４Ｅ、５Ｄの外径Ｆより大なる直径を有する大径孔６Ａが長手軸心方向Ｘ−Ｘに沿って穿設され、さらに大径孔６Ａの一側Ａに形成される第１環状係止段部６Ｂを介して、一側Ａに向けて第１小径孔６Ｃが開口して形成される。又、大径孔６Ａの他側Ｂに形成される第２環状係止段部６Ｃを介して、他側Ｂに向けて第２小径孔６Ｄが開口して形成される。この第１小径孔６Ｃ及び第２小径孔６Ｄの直径は、第１係止突部４Ｃの小径突部４Ｄ、第２係止突部５Ｂの小径突部５Ｃを挿入しうる径に選択されるものであり、且つ大径孔６Ａの直径より小径をなす。
【０００８】
そして、ダイヤフラムアッセンブリーＤｆは、以下によって組みつけられる。負圧ダイヤフラム５の他側面に形成されるプレート嵌合溝５Ｆ内にプレート７を嵌合配置し、次いで、第２係止突部５Ｂをリテーナ６内に挿入配置する。すなわち、第２係止突部５Ｂの大径突部５Ｄは、収縮変形されつつ第２小径孔６Ｄ内を通過してリテーナ６の大径孔６Ａ内に配置され、小径突部５Ｃは第２小径孔６Ｄ内に挿入配置される。かかる状態において、第２係止突部５Ｂの第２環状係止面部５Ｅは、リテーナ６の第２環状係止段部６Ｃに対向して配置され、以上をもって、リテーナ６とプレート７を備えた負圧ダイヤフラム５とが結合された。
【０００９】
一方、燃料ダイヤフラム４の第１係止突部４Ｃは、リテーナ６内に挿入配置される。すなわち、第１係止突部４Ｃの大径突部４Ｅは、収縮変形されつつ第１小径孔６Ｃ内を通過してリテーナ６の大径孔６Ａ内に配置され、小径突部４Ｄは第１小径孔６Ｃ内に挿入配置される。かかる状態において、第１係止突部４Ｃの第１環状係止面部４Ｆは、リテーナ６の第１環状係止段部６Ｂに対向して配置され、以上をもって、リテーナ６と燃料ダイヤフラム４とが結合された。
【００１０】
そして、負圧式燃料弁は、以下によって組みつけられる。再び図１０に戻って説明する。大気室本体２の一側平坦面２Ｂ上に燃料ダイヤフラム４の薄膜４Ａの環状の外周部が配置され、他側平坦面２Ａ上に負圧ダイヤフラム５の薄膜５Ａの環状の外周部が配置される。これによると、燃料ダイヤフラム４の弁部４Ｂは、大気室本体２の一側平坦面２Ｂより一側Ａに向かって配置され、プレート７は、大気室本体２の他側平坦面２Ａより他側Ｂに向かって配置される。
【００１１】
そして、かかる大気室本体２の一側平坦面２Ｂを弁本体１の平坦面１Ｂ上に配置し、次いで大気室本体２の他側平坦面２Ａ上に負圧室本体３の平坦面３Ａが配置され、この状態において、弁本体１と大気室本体２と負圧室本体３とが図示されぬビス等によって固定される。
【００１２】
以上によると、燃料ダイヤフラム４は、弁本体１の燃料室１Ａの平坦面１Ｂへの開口を閉塞して、閉塞された燃料室１Ａを形成する。又、大気室本体２の大気室２Ｃの一側平坦面２Ｂへの開口は、燃料ダイヤフラム４によって閉塞され、大気室本体２の大気室２Ｃの他側平坦面２Ａへの開口は、負圧ダイヤフラム５によって閉塞され、もって大気室本体２には閉塞された大気室２Ｃが形成される。又、負圧室本体３の平坦面３Ａに開口する負圧室３Ｂは負圧ダイヤフラム５によって閉塞され、閉塞された負圧室３Ｂが形成される。
【００１３】
そして、負圧室３Ｂ内には、スプリング８が縮設されるもので、これによると、負圧ダイヤフラム５、リテーナ６、燃料ダイヤフラム４によって形成されるダイヤフラムアッセンブリーＤｆは、図において一側Ａへ押圧されるもので、弁部４Ｂは、燃料弁座１Ｄに当接される。
【００１４】
そして、機関の停止時の如く、負圧導入路３Ｃを介して負圧室３Ｂ内へ負圧が導入されない状態において、ダイヤフラムアッセンブリーＤｆは、スプリング８によって一側Ａへ押圧されるもので、これによると、弁部４Ｂは燃料弁座１Ｄに当接し、燃料流入路１Ｃと燃料流出路１Ｅとを遮断する。一方、機関の運転時の如く、負圧導入路３Ｃを介して負圧室３Ｂ内へ負圧が導入されると、ダイヤフラムアッセンブリーＤｆは、スプリング８のバネ力に抗して他側Ｂへ移動するもので、これによると、弁部４Ｂは燃料弁座１Ｄより離反し、燃料流入路１Ｃと燃料流出路１Ｅとを連通する。
【００１５】
【発明が解決しようとする課題】
かかる従来の負圧式燃料弁によると、以下の不具合を有する。ダイヤフラムアッセンブリーＤｆにおいて、負圧ダイヤフラム５の第２係止突部５Ｂの大径突部５Ｄは、リテーナ６の第２小径孔６Ｄを収縮変形されつつリテーナ６の大径孔６Ａ内に挿入配置され、燃料ダイヤフラム４の第１係止突部４Ｃの大径突部４Ｅは、リテーナ６の第１小径孔６Ｃ内を収縮変形されつつリテーナ６の大径孔６Ａ内に挿入配置される。そして、第２係止突部５Ｂの第２環状係止面部５Ｅがリテーナ６の第２環状係止段部６Ｃに臨んで係合配置されること。及び第１係止突部４Ｃの第１環状係止面部４Ｆがリテーナ６の第１環状係止段部６Ｂに臨んで係合配置されること。によって負圧ダイヤフラム５と燃料ダイヤフラム４とが同期的に移動しうるものである。
【００１６】
一方、前述の如く、負圧ダイヤフラム５、燃料ダイヤフラム４は、ゴム材料によって形成されるもので、これによると、例えば、負圧式燃料弁が配置される環境温度が大きく上昇した状態において、長期間に渡って使用された際、ゴム材料の硬度は軟化する傾向にある。これによると、前記ダイヤフラム４、５の大径突部４Ｅ、５Ｄがリテーナ６より脱出し、負圧ダイヤフラム５と燃料ダイヤフラム４との結合が阻害され、それらを同期的に移動させることができないという不具合を生ずる恐れがある。
【００１７】
この不具合を解決するには、第１には、各ダイヤフラム４、５のゴム材料硬度を上げることが考慮される。然しながら、これによると、ダイヤフラム４、５の剛性が増してダイヤフラム４、５の円滑な作動性及び応答性が阻害されること。及び大径突部４Ｅ、５Ｄを第１小径孔６Ｃ、第２小径孔６Ｄ内へ挿入する際における挿入作業性が大きく悪化すること。の問題を生ずる。第２には、各ダイヤフラム４、５の大径突部４Ｅ、５Ｄの外径を大きくして、環状係止面部４Ｆ、５Ｅと、環状係止段部６Ｂ、６Ｃとの係合代を増加することが考慮される。然しながら、これによると、大径突部４Ｅ、５Ｄを第１小径孔６Ｃ、第２小径孔６Ｄ内へ挿入する際の挿入作業が大きく悪化し、挿入不能となる問題を生ずる。
【００１８】
本発明になる負圧式燃料弁は、上記不具合に鑑み成されたもので、環境温度の上昇時にあっても、確実に燃料通路の開閉機能を長期に渡って保証しうる負圧式燃料弁を、ダイヤフラムの作動性及び応答性を阻害することなく、ダイヤフラムとリテーナの組みつけ性を阻害することなく、提供することにある。
【００１９】
【課題を解決する為の手段】
本発明になる負圧式燃料弁は、前記目的達成の為に、燃料流入路と、燃料流出路と、燃料流入路の下流端にあって、燃料流出路に連なる燃料室内に臨んで形成された燃料弁座とを備える弁本体と、燃料室に臨む大気室を備え、弁本体上に配置される大気室本体と、大気室に臨む負圧室を備え、大気室本体上に配置される負圧室本体と、弁本体と大気室本体とによって挟持されて燃料室と大気室とに区分するとともに燃料室側に、燃料弁座を開閉する弁部を備え、大気室側に小径突部と大径突部と、小径突部と大径突部との間に形成される第１環状係止面部とよりなる第１係止突部を備えた燃料ダイヤフラムと、大気室本体と負圧室本体とによって挟持されて大気室と負圧室とに区分するとともに大気室側に、小径突部と大径突部と、小径突部と大径突部との間に形成される第２環状係止面部とよりなる第２係止突部を備えた負圧ダイヤフラムと、大気室内にあって、燃料ダイヤフラムの第１係止突部と、負圧ダイヤフラムの第２係止突部とを結合し、負圧ダイヤフラムと燃料ダイヤフラムとを同期的に連結するリテーナとを備え、負圧室内に導入される負圧に応じて燃料ダイヤフラムを動作し、弁部をもって燃料弁座を開閉制御する負圧式燃料弁において、燃料ダイヤフラム及び負圧ダイヤフラムはゴム材料によって形成されるとともに少なくとも第１係止突部、第２係止突部の大径突部内には、剛性材料によりなる芯金が一体成形されて配置され、一方、リテーナは、大径突部の外径より大なる直径を有する大径孔と、大径孔から第１環状係止段部を介して一側に向かい小径突部を保持しうる第１小径孔と、大径孔から第２環状係止段部を介して他側に向かい小径突部を保持しうる第２小径孔とが穿設され、さらに、前記リテーナは、その長手軸心線に沿って結合自在に二分割して形成され、第１係止突部の大径突部、第２係止突部の大径突部を、分割されたリテーナを結合することによって形成される大径孔内に配置し、第１係止突部の小径突部、第２係止突部の小径突部を、分割されたリテーナを結合することによって形成される第１小径孔、及び第２小径孔内に配置し、第１係止突部の第１環状係止面部を第１係止段部に対向配置し、第２係止突部の第２環状係止面部を第２係止段部に対向配置したことを第１の特徴とする。
【００２０】
又、本発明は、前記第１の特徴に加え、前記、結合されたリテーナの外周に結合リングを嵌合配置したことを第２の特徴とする。
【００２１】
更に又、本発明は、前記第１の特徴に加え、前記、芯金の外径を、各小径突部の外径より大なる直径としたことを第３の特徴とする。
【００２２】
【実施例】
以下、本発明になる負圧式燃料弁の一実施例を説明する。本発明のものと従来のものとは、ダイヤフラムアッセンブリーＤｆが異なる。相違する構成についてのみ説明し、同一構成部分については従来と同一符号を使用し説明を省略する。図１によって燃料ダイヤフラム４について説明する。図１は、燃料ダイヤフラム４の要部を示す。燃料ダイヤフラム４の第１係止突部４Ｃ内には、芯金９が一体的に配置される。この芯金９は、金属材料、合成樹脂材料、等のゴム材料より硬度の高い剛性材料によって形成され、少なくとも大径突部４Ｅ内に配置される。具体的にこの芯金９は、大径突部４Ｅの外径Ｆより小なる径Ｇを有し、燃料ダイヤフラム４をゴム材料によって成形する際、第１係止突部４Ｃ内に一体成形されて配置される。本実施例において、芯金９の一部は小径突部４Ｄ内へ進入して配置された。
【００２３】
図２によって負圧ダイヤフラム５について説明する。図２は負圧ダイヤフラム５の要部を示す。負圧ダイヤフラム５の第２係止突部５Ｂ内には、芯金９が一体的に配置される。この芯金９は、金属材料、合成樹脂材料、等のゴム材料より硬度の高い剛性材料によって形成され、少なくとも大径突部５Ｄ内に配置される。具体的にこの芯金９は、大径突部５Ｄの外径Ｆより小なる径Ｇを有し、負圧ダイヤフラム５をゴム材料によって成形する際、第２係止突部５Ｂ内に一体成形されて配置される。本実施例において、芯金９の一部は小径突部５Ｃ内へ進入して配置される。
【００２４】
次に、図３から図６によってリテーナ１２について説明する。リテーナ１２は、長手軸心線Ｘ−Ｘに沿って二分割１２Ａ、１２Ｂされて形成され、この二分割された各リテーナ１２Ａ、１２Ｂは結合されて単一のリテーナ１２を形成する。説明を容易にする為に各リテーナ１２Ａ、１２Ｂが結合されて単一のリテーナ１２が形成された状態において説明する。リテーナ１２は例えばアルミニウム、合成樹脂等の剛性材料よりなり、以下によって形成される。リテーナ１２は円柱形状をなし、その中心部分に、第１係止突部４Ｃ、第２係止突部５Ｂの大径突部４Ｅ、５Ｄの外径Ｆより大なる直径を有する大径孔１２Ｃが長手軸心方向Ｘ−Ｘに沿って穿設され、さらに大径孔１２Ｃの一側Ａに形成される第１環状係止段部１２Ｄを介して、一側Ａに向けて第１小径孔１２Ｅが開口して形成される。又、大径孔１２Ｃの他側Ｂに形成される第２環状係止段部１２Ｆを介して、他側Ｂに向けて第２小径孔１２Ｇが開口して形成される。この第１小径孔１２Ｅ及び第２小径孔１２Ｇの直径は、第１係止突部４Ｃの小径突部４Ｄ、第２係止突部５Ｂの小径突部５Ｃを挿入して保持しうる径に選択されるものであり、且つ大径孔１２Ｃより小径をなす。そして、分割される下方のリテーナ１２Ｂの分割面１２Ｈには、結合孔１２Ｊが穿設され、分割される上方のリテーナ１２Ａの分割面１２Ｋには前記結合孔１２Ｊに嵌合される結合突部１２Ｌが突出して形成される。すなわち、下方のリテーナ１２Ｂの分割面１２Ｈと上方のリテーナ１２Ａの分割面１２Ｋとを当接するとともに結合突部１２Ｌを結合孔１２Ｊ内へ嵌合することによって下方のリテーナ１２Ｂと上方のリテーナ１２Ａとは結合されて一体のリテーナ１２を形成することができる。尚、結合孔１２Ｊと結合突部１２Ｌとの嵌合時に圧縮代をもって嵌合すると、リテーナ１２Ａ、１２Ｂの結合を強固に行なうことができる。又、上方のリテーナ１２Ａと下方のリテーナ１２Ｂの結合手段は適宜選択すればよいもので上記結合方法に限定されない。例えば接着剤を用いてもよい。
【００２５】
そしてダイヤフラムアッセンブリーＤｆは以下によって組みつけられる。分割された下方のリテーナ１２Ｂの半円形をなす第２小径孔１２Ｇに、負圧ダイヤフラム５の第２係止突部５Ｂの小径突部５Ｃを配置するとともに、第２係止突部５Ｂの大径突部５Ｄを半円形をなす大径孔１２Ｃ内に配置する。このとき半円をなす第２環状係止段部１２Ｆに第２係止突部５Ｂの第２環状係止面部５Ｅは当接配置される。又、半円形をなす第１小径孔１２Ｅに、燃料ダイヤフラム４の第１係止突部４Ｃの小径突部４Ｄを配置するとともに第１係止突部４Ｃの大径突部４Ｅを半円形をなす大径孔１２Ｃ内に配置する。このとき半円をなす第１環状係止段部１２Ｄに第１係止突部４Ｃの第１環状係止面部４Ｆは当接配置される。
【００２６】
そして、前記状態にある下方のリテーナ１２Ｂの分割面１２Ｈ上に臨んで上方のリテーナ１２Ａの分割面１２Ｋを配置するもので、このとき、上方のリテーナ１２Ａの半円形をなす第２小径孔１２Ｇは負圧ダイヤフラム５の第２係止突部５Ｂの小径突部５Ｃに臨んで配置され、半円形をなす大径孔１２Ｃに臨んで第２係止突部５Ｂの大径突部５Ｄが配置され、半円をなす第２環状係止段部１２Ｆに臨んで第２係止突部５Ｂの第２環状係止面部５Ｅが配置される。一方、上方のリテーナ１２Ａの半円形をなす第１小径孔１２Ｅは燃料ダイヤフラム４の第１係止突部４Ｃの小径突部４Ｄに臨んで配置され、半円形をなす大径孔１２Ｃに臨んで第１係止突部４Ｃの大径突部４Ｅが配置され、半円をなす第１環状係止段部１２Ｄに臨んで第１係止突部４Ｃの第１環状係止面部４Ｆが配置される。
【００２７】
そして、かかる状態において、下方のリテーナ１２Ｂの分割面１２Ｈに上方のリテーナ１２Ａの分割面１２Ｋを当接するとともに結合孔１２Ｊ内に結合突部１２Ｌを嵌合配置する。以上によると、下方のリテーナ１２Ｂと上方のリテーナ１２Ａとは結合されて一体のリテーナ１２を形成するもので、このリテーナ１２の大径孔１２Ｃ内に負圧ダイヤフラム５の第２係止突部５Ｂの大径突部５Ｄが配置されるとともに第２小径孔１２Ｇ内に第２係止突部５Ｂの小径突部５Ｃが配置され、さらに第２環状係止段部１２Ｆに対向して第２係止突部５Ｂの第２環状係止面部５Ｅが配置される。
【００２８】
一方、リテーナ１２の大径孔１２Ｃ内に燃料ダイヤフラム４の第１係止突部４Ｃの大径突部４Ｅが配置され、第１小径孔１２Ｅ内に第１係止突部４Ｃの小径突部４Ｄが配置され、さらに第１環状係止段部１２Ｄに対向して第１係止突部４Ｃの第１環状係止面部４Ｆが配置される。以上によって負圧ダイヤフラム５と燃料ダイヤフラム４とがリテーナ１２によって結合された。このダイヤフラムアッセンブリーＤｆは、図７に示される。
【００２９】
そして、このダイヤフラムアッセンブリーＤｆは、従来と同様に、燃料ダイヤフラム４が弁本体１の平坦面１Ｂと大気室本体２の一側平坦面２Ｂとの間に挟持され、負圧ダイヤフラム５が大気室本体２の他側平坦面２Ａと負圧室本体３の平坦面３Ａとの間に挟持される。
【００３０】
而して、負圧導入路３Ｃを介して負圧室３Ｂ内に導入される負圧に応じて負圧ダイヤフラム５が移動すると、この移動は、リテーナ６を介して燃料ダイヤフラム４に伝達されて燃料ダイヤフラム４を負圧ダイヤフラム５と同期して移動させるもので、これによって弁部４Ｂは負圧室３Ｂ内の負圧に応じて燃料弁座１Ｄを開閉制御する。
【００３１】
以上述べた本発明の負圧式燃料弁によると、負圧ダイヤフラム５の少なくとも大径突部５Ｄ内に剛性を有する芯金９を配置したので、負圧ダイヤフラム５が高温度状態にさらされてゴム材料が軟化したとしても大径突部５Ｄの外径Ｆが内方へ大きく縮小することが抑止される。これは、少なくとも大径突部５Ｄの内方に芯金９が配置されて大径突部５Ｄの内方へのゴムの移動を抑止するからである。又、燃料ダイヤフラム４の少なくとも大径突部４Ｅ内に剛性を有する芯金９を配置したので、燃料ダイヤフラム４が高温度状態にさらされてゴム材料が軟化したとしても大径突部４Ｅの外径Ｆが内方へ大きく縮小することが抑止される。これは、少なくとも大径突部４Ｅの内方に芯金９が配置されて大径突部４Ｅの内方へのゴムの移動を抑止するからである。以上の如く、第１係止突部４Ｃの大径突部４Ｅ及び第２係止突部５Ｂの大径突部５Ｄの外径Ｆが内方へ縮小されることが抑止されたことによると、負圧式燃料弁が長期に渡って高温度状態にさらされたとしても、大径突部５Ｄ、４Ｅがリテーナ１２の第２小径孔１２Ｇ、第１小径孔１２Ｅから脱出することがないもので、長期に渡って安定して且つ確実に弁部４Ｂの開閉機能を保証することができる。
【００３２】
又、リテーナ１２を二分割１２Ａ、１２Ｂとし、分割された状態において、リテーナ１２の大径孔１２Ｃ内に大径突部５Ｄ、４Ｅを配置したのちに二分割１２Ａ、１２Ｂされた各リテーナを結合して単一のリテーナ１２としたことによると、前記大径突部５Ｄ、４Ｅを小径孔１２Ｇ、１２Ｅを介することなく大径孔１２Ｃ内に配置できたもので、これら第１係止突部４Ｃ、第２係止突部５Ｂのリテーナ１２内への装着を容易に行なうことができたものである。特に、大径突部５Ｄ、４Ｅを小径孔１２Ｇ、１２Ｅを介することなく大径孔１２Ｃ内に配置できたことは、ダイヤフラム４、５の環状係止面部４Ｆ、５Ｅと、リテーナ１２の環状係止段部１２Ｆ、１２Ｄとの当接代（引掛り代）を大きくとることができ、リテーナ１２と各ダイヤフラム４、５の係止突部４Ｃ、５Ｂとの結合をより一層強固で且つ確実に行なうことができたものである。
【００３３】
又、図９に示されるように、リテーナ１２の外周に環状をなす結合リング１３を装着すると、分割されたリテーナ１２Ａ、１２Ｂのより一層強固な結合を行なうことができる。尚、この結合リング１３に長手方向に沿ってスリット溝（図示せず）を入れると、結合リング１３のスリット溝の溝幅を拡大しつつリテーナ１２の外周に結合リング１３を装着できてその装着作業性を向上できる。
【００３４】
更に、芯金９の外径Ｇを各小径突部４Ｄ、５Ｃの外径Ｅ以上の直径とすると、各大径突部４Ｅ、５Ｄの外径Ｆは小径突部４Ｄ、５Ｃの外径Ｅ以下に縮小されることは絶対にないもので、これによって大径突部４Ｅ、５Ｄの各小径孔１２Ｇ、１２Ｅからの脱出をより確実に抑止できる。
【００３５】
更に又、負圧ダイヤフラム５、燃料ダイヤフラム４のゴム材料は従来と何等変更する必要がないもので、これによると各ダイヤフラムの動特性に何等悪影響を及ぼすことがなく、従来の円滑なダイヤフラムの動特性を維持できる。
【００３６】
【発明の効果】
以上の如く、本発明になる負圧式燃料弁によると、燃料ダイヤフラム及び負圧ダイヤフラムはゴム材料によって形成されるとともに少なくとも第１係止突部、第２係止突部の大径突部内には、剛性材料によりなる芯金が一体成形されて配置され、一方、リテーナは、大径突部の外径より大なる直径を有する大径孔と、大径孔から第１環状係止段部を介して一側に向かい小径突部を保持しうる第１小径孔と、大径孔から第２環状係止段部を介して他側に向かい小径突部を保持しうる第２小径孔とが穿設され、さらに、前記リテーナは、その長手軸心線に沿って結合自在に二分割して形成され、第１係止突部の大径突部、第２係止突部の大径突部を、分割されたリテーナを結合することによって形成される大径孔内に配置し、第１係止突部の小径突部、第２係止突部の小径突部を、分割されたリテーナを結合することによって形成される第１小径孔、及び第２小径孔内に配置し、第１係止突部の第１環状係止面部を第１係止段部に対向配置し、第２係止突部の第２環状係止面部を第２係止段部に対向配置したので、負圧式燃料弁が高温度状態にさらされたとしても、負圧ダイヤフラムと燃料ダイヤフラムとをリテーナによって安定して且つ確実に結合保持できるもので長期間に渡って確実な弁部の開閉機能を保証できるものである。
【００３７】
又、リテーナが分割された状態において、燃料及び負圧ダイヤフラムの各大径突部及び小径突部が分割された各リテーナの大径孔及び小径孔内に配置され、かかる状態において両リテーナを当接して一体のリテーナとすることによって燃料ダイヤフラムと負圧ダイヤフラムとをリテーナを介して結合できたもので、これによって燃料ダイヤフラムと負圧ダイヤフラムとの結合作業性を大きく向上できたものであり、特に環状係止面部と環状係止段部との当接代を大きくとることができ、それらの結合を一層確実にして且つ強固に行なうことができたものである。
【００３８】
又、結合されたリテーナの外周に結合リングを装着することによって、分割されたリテーナの結合をより一層強固に行なうことができる。
【００３９】
更に又、芯金の外径を小径突部の外径以上の直径としたことによって、各大径突部が各小径孔より脱出することをより一層抑止できる。
【図面の簡単な説明】
【図１】本発明の負圧式燃料弁に用いられる燃料ダイヤフラムの一実施例を示す要部拡大縦断面図。
【図２】本発明の負圧式燃料弁に用いられる負圧ダイヤフラムの一実施例を示す要部拡大縦断面図。
【図３】本発明の負圧式燃料弁に用いられるリテーナの一実施例を示し、且つ分割されるリテーナが結合されて一体の状態を示す側面図。
【図４】図３の右側面図。
【図５】図３のＪ−Ｊ線における縦断面図。
【図６】図４のＫ−Ｋ線における縦断面図。
【図７】本発明の負圧式燃料弁に用いられるダイヤフラムアッセンブリーの一実施例を示す拡大縦断面図。
【図８】本発明の負圧式燃料弁の一実施例を示す縦断面図。
【図９】本発明の負圧式燃料弁の他の実施例を示す縦断面図。
【図１０】従来の負圧式燃料弁を示す縦断面図。
【図１１】図１０に用いられるダイヤフラムアッセンブリーの拡大縦断面図。
【符号の説明】
４燃料ダイヤフラム
４Ｃ第１係止突部
４Ｄ小径突部
４Ｅ大径突部
４Ｆ第１環状係止面部
５負圧ダイヤフラム
５Ｂ第２係止突部
５Ｃ小径突部
５Ｄ大径突部
５Ｅ第２環状係止面部
１２リテーナ
１２Ａ、１２Ｂ分割されたリテーナ
１２Ｃ大径孔
１２Ｅ第１小径孔
１２Ｇ第２小径孔
１２Ｄ第１係止段部
１２Ｆ第２係止段部
１３結合リング[0001]
[Industrial application fields]
The present invention relates to a negative pressure fuel valve that opens and closes a flow path by a diaphragm that moves in accordance with a negative pressure introduced into a negative pressure chamber. The negative pressure fuel valve is mounted on an internal combustion engine such as a motorcycle. It is arranged in the fuel flow path to the carburetor and is used as an automatic fuel valve that automatically opens the fuel valve by the negative pressure generated by the operation of the engine and automatically supplies the fuel in the fuel tank to the carburetor .
[0002]
[Prior art]
A conventional negative pressure fuel valve is shown in FIG. 1 is a valve body, which is formed by the following. 1A is a fuel chamber that is recessed from a flat end surface 1B formed on the other side B (left side in the figure) of the valve body 1 toward one side A (right side in the figure), and the center bottom of the fuel chamber 1A Is formed with an open fuel valve seat 1D connected to the fuel inflow passage 1C. Further, a fuel outflow passage 1E opens from the fuel chamber 1A downward. In this state, the fuel chamber 1A is still open to the flat surface 1B. The fuel inflow passage 1C is connected to, for example, a fuel tank (not shown), and the fuel outflow passage 1E is connected to, for example, a fuel introduction passage (not shown) of the carburetor.
[0003]
2 is an atmospheric chamber body, which is formed by the following. In the atmospheric chamber body 2, the other side flat end surface 2A is formed on the other side B, the one side flat surface 2B is formed on one side A, and the atmospheric chamber extends from the other side flat surface 2A toward the one side flat surface 2B. 2C is formed through. In this state, the atmosphere chamber 2C is still open at both ends. Then, an air release path 2D is bored outward from the atmosphere chamber 2C.
[0004]
3 is a negative pressure chamber main body formed by the following. The negative pressure chamber body 3 has a flat surface 3A formed on one side A thereof, a negative pressure chamber 3B is recessed from the flat surface 3A toward the other side B, and further outward from the negative pressure chamber 3B. A negative pressure introduction path 3C is bored toward the end. In this state, the negative pressure chamber 3B is still open to the flat surface 3A.
[0005]
Df is a diaphragm assembly and is shown in FIG. The diaphragm assembly Df is mainly composed of a fuel diaphragm 4, a negative pressure diaphragm 5, and a retainer 6. The fuel diaphragm 4 is made of a rubber material and is formed by the following. 4A is an umbrella-shaped thin film, and is formed such that the valve portion 4B protrudes from one side surface of the thin film 4A toward one side A. Further, a first locking protrusion 4C is formed to protrude from the other side surface of the thin film 4A toward the other side B. The first locking projection 4C has a small-diameter projection 4D having an outer diameter E extending from the other side surface of the thin film 4A toward the other side B, and then has an outer diameter F larger than the outer diameter E of the small-diameter projection 4D. A large-diameter projection 4E having the same is formed toward the other side B. A first annular locking surface portion 4F forming an annular surface is formed at the connecting portion between the small diameter protrusion 4D and the large diameter protrusion 4E.
[0006]
The negative pressure diaphragm 5 is made of a rubber material and is formed as follows. 5A is a disk-shaped thin film. A second locking projection 5B is formed from one side surface of the thin film 5A toward one side A. The second locking projection 5B has a small-diameter projection 5C having an outer diameter E extending from one side surface of the thin film 5A toward one side A, and then has an outer diameter F larger than the outer diameter E of the small-diameter projection 5C. A large-diameter projection 5D having the same is further formed toward one side A. A second annular locking surface portion 5E having an annular surface is formed at the connecting portion between the small diameter protrusion 5C and the large diameter protrusion 5D. Reference numeral 5F denotes a plate fitting groove formed to protrude from the other side surface of the thin film 5A to the other side B, and a dish-like plate 7 is fitted and disposed.
[0007]
The retainer 6 is made of a rigid material such as aluminum or synthetic resin, and is formed as follows. The retainer 6 has a cylindrical shape, and has a large diameter inward of the central portion thereof that is larger than the outer diameter F of the large-diameter protrusions 4E and 5D of the first locking protrusion 4C and the second locking protrusion 5B. The diameter hole 6A is drilled along the longitudinal axial direction XX, and further toward the one side A via the first annular locking step portion 6B formed on one side A of the large diameter hole 6A. One small-diameter hole 6C is formed to open. A second small diameter hole 6D is formed to open toward the other side B via a second annular locking step 6C formed on the other side B of the large diameter hole 6A. The diameters of the first small-diameter hole 6C and the second small-diameter hole 6D are selected so that the small-diameter protrusion 4D of the first locking protrusion 4C and the small-diameter protrusion 5C of the second locking protrusion 5B can be inserted. The diameter is smaller than the diameter of the large-diameter hole 6A.
[0008]
The diaphragm assembly Df is assembled as follows. The plate 7 is fitted and arranged in a plate fitting groove 5F formed on the other side surface of the negative pressure diaphragm 5, and then the second locking projection 5B is inserted and arranged in the retainer 6. That is, the large-diameter projection 5D of the second locking projection 5B is disposed in the large-diameter hole 6A of the retainer 6 while passing through the second small-diameter hole 6D while being contracted and deformed. The small diameter hole 6D is inserted and arranged. In such a state, the second annular locking surface portion 5E of the second locking projection 5B is disposed to face the second annular locking step portion 6C of the retainer 6, and includes the retainer 6 and the plate 7 as described above. The negative pressure diaphragm 5 was combined.
[0009]
On the other hand, the first locking projection 4C of the fuel diaphragm 4 is inserted into the retainer 6 and disposed. That is, the large-diameter protrusion 4E of the first locking protrusion 4C is disposed in the large-diameter hole 6A of the retainer 6 while passing through the first small-diameter hole 6C while being contracted and deformed. The small diameter hole 6C is inserted and arranged. In such a state, the first annular locking surface portion 4F of the first locking protrusion 4C is disposed to face the first annular locking step portion 6B of the retainer 6, and the retainer 6 and the fuel diaphragm 4 are thus connected. Combined.
[0010]
The negative pressure fuel valve is assembled as follows. Returning again to FIG. An annular outer peripheral portion of the thin film 4A of the fuel diaphragm 4 is disposed on one flat surface 2B of the atmospheric chamber body 2, and an annular outer peripheral portion of the thin film 5A of the negative pressure diaphragm 5 is disposed on the other flat surface 2A. . According to this, the valve portion 4B of the fuel diaphragm 4 is disposed toward the one side A from the one side flat surface 2B of the atmospheric chamber body 2, and the plate 7 is located on the other side from the other side flat surface 2A of the atmosphere chamber body 2. It is arranged toward B.
[0011]
Then, the one side flat surface 2B of the atmospheric chamber main body 2 is arranged on the flat surface 1B of the valve main body 1, and then the flat surface 3A of the negative pressure chamber main body 3 is arranged on the other side flat surface 2A of the atmospheric chamber main body 2. In this state, the valve main body 1, the atmospheric chamber main body 2, and the negative pressure chamber main body 3 are fixed by screws or the like not shown.
[0012]
According to the above, the fuel diaphragm 4 closes the opening to the flat surface 1B of the fuel chamber 1A of the valve body 1 to form a closed fuel chamber 1A. Further, the opening of the atmospheric chamber body 2 to the one flat surface 2B of the atmospheric chamber 2C is closed by the fuel diaphragm 4, and the opening of the atmospheric chamber body 2 to the other flat surface 2A of the atmospheric chamber 2C is a negative pressure diaphragm. Thus, the atmospheric chamber body 2 </ b> C is formed in the atmospheric chamber body 2. Further, the negative pressure chamber 3B that opens to the flat surface 3A of the negative pressure chamber body 3 is closed by the negative pressure diaphragm 5, thereby forming a closed negative pressure chamber 3B.
[0013]
A spring 8 is contracted in the negative pressure chamber 3B. According to this, the diaphragm assembly Df formed by the negative pressure diaphragm 5, the retainer 6, and the fuel diaphragm 4 is directed to one side A in the drawing. The valve portion 4B is pressed against the fuel valve seat 1D.
[0014]
In a state where no negative pressure is introduced into the negative pressure chamber 3B via the negative pressure introduction path 3C, such as when the engine is stopped, the diaphragm assembly Df is pressed to the one side A by the spring 8. According to this, the valve portion 4B abuts on the fuel valve seat 1D and shuts off the fuel inflow passage 1C and the fuel outflow passage 1E. On the other hand, when a negative pressure is introduced into the negative pressure chamber 3B via the negative pressure introduction path 3C as during engine operation, the diaphragm assembly Df moves to the other side B against the spring force of the spring 8. Therefore, according to this, the valve portion 4B is separated from the fuel valve seat 1D, and the fuel inflow passage 1C and the fuel outflow passage 1E are communicated.
[0015]
[Problems to be solved by the invention]
Such a conventional negative pressure fuel valve has the following problems. In the diaphragm assembly Df, the large-diameter protrusion 5D of the second locking protrusion 5B of the negative pressure diaphragm 5 is inserted and disposed in the large-diameter hole 6A of the retainer 6 while the second small-diameter hole 6D of the retainer 6 is contracted and deformed. The large-diameter protrusion 4E of the first locking protrusion 4C of the fuel diaphragm 4 is inserted into the large-diameter hole 6A of the retainer 6 while being contracted and deformed in the first small-diameter hole 6C of the retainer 6. Then, the second annular locking surface portion 5E of the second locking protrusion 5B is engaged with the second annular locking step portion 6C of the retainer 6. In addition, the first annular locking surface portion 4F of the first locking projection 4C is engaged with the first annular locking step portion 6B of the retainer 6. Thus, the negative pressure diaphragm 5 and the fuel diaphragm 4 can move synchronously.
[0016]
On the other hand, as described above, the negative pressure diaphragm 5 and the fuel diaphragm 4 are formed of a rubber material. According to this, for example, in a state where the environmental temperature in which the negative pressure type fuel valve is disposed is greatly increased, When used for a long time, the hardness of the rubber material tends to soften. According to this, the large-diameter projections 4E and 5D of the diaphragms 4 and 5 escape from the retainer 6, and the connection between the negative pressure diaphragm 5 and the fuel diaphragm 4 is inhibited, and they cannot be moved synchronously. There is a risk of malfunction.
[0017]
In order to solve this problem, firstly, it is considered that the rubber material hardness of each of the diaphragms 4 and 5 is increased. However, according to this, the rigidity of the diaphragms 4 and 5 is increased, and the smooth operability and responsiveness of the diaphragms 4 and 5 are hindered. In addition, the insertion workability when the large-diameter protrusions 4E and 5D are inserted into the first small-diameter hole 6C and the second small-diameter hole 6D is greatly deteriorated. Cause problems. Secondly, the outer diameter of the large-diameter projections 4E and 5D of the diaphragms 4 and 5 is increased to increase the engagement margin between the annular locking surface portions 4F and 5E and the annular locking step portions 6B and 6C. To be considered. However, according to this, the insertion work when inserting the large-diameter protrusions 4E, 5D into the first small-diameter hole 6C and the second small-diameter hole 6D is greatly deteriorated, resulting in a problem that the insertion is impossible.
[0018]
The negative pressure fuel valve according to the present invention has been made in view of the above-mentioned problems, and a negative pressure fuel valve that can reliably guarantee the opening / closing function of the fuel passage for a long period of time even when the environmental temperature rises, The object of the present invention is to provide a diaphragm and retainer without inhibiting the operability and responsiveness of the diaphragm and without inhibiting the assembling ability of the diaphragm and the retainer.
[0019]
[Means for solving the problems]
In order to achieve the above object, the negative pressure fuel valve according to the present invention is formed at the downstream end of the fuel inflow passage, the fuel outflow passage, and the fuel inflow passage and facing the fuel chamber that is connected to the fuel outflow passage. A valve body having a fuel valve seat, an atmosphere chamber facing the fuel chamber, an atmosphere chamber body disposed on the valve body, a negative pressure chamber facing the atmosphere chamber, and a negative chamber disposed on the atmosphere chamber body The pressure chamber body, the valve body and the atmospheric chamber body are sandwiched between the fuel chamber and the atmospheric chamber, the fuel chamber side is provided with a valve portion for opening and closing the fuel valve seat, and the atmospheric chamber side has a small-diameter protrusion. A fuel diaphragm having a first locking protrusion including a large diameter protrusion, and a first annular locking surface formed between the small diameter protrusion and the large diameter protrusion, an air chamber body, and a negative pressure chamber A small-diameter projection, a large-diameter projection, and a small-diameter projection on the atmospheric chamber side while being sandwiched between the main body and divided into an atmospheric chamber and a negative pressure chamber A negative pressure diaphragm having a second locking projection formed by a second annular locking surface formed between the large-diameter projection and a first locking projection of the fuel diaphragm in the atmosphere chamber; A retainer that connects the second locking projection of the negative pressure diaphragm and connects the negative pressure diaphragm and the fuel diaphragm synchronously, and operates the fuel diaphragm according to the negative pressure introduced into the negative pressure chamber In the negative pressure type fuel valve that controls the opening and closing of the fuel valve seat with the valve portion, the fuel diaphragm and the negative pressure diaphragm are formed of a rubber material and have a large-diameter projection of at least the first locking projection and the second locking projection. A cored bar made of a rigid material is integrally formed and disposed in the part. On the other hand, the retainer has a large-diameter hole having a diameter larger than the outer diameter of the large-diameter protrusion, and a first annular lock from the large-diameter hole. A small-diameter projection facing one side through a step A first small-diameter hole that can be held, and a second small-diameter hole that can hold the small-diameter protrusion from the large-diameter hole to the other side through the second annular locking stepped portion, and further, the retainer, It is formed by being split in two along the longitudinal axis so as to be freely coupled, and the large diameter projection of the first locking projection and the large diameter projection of the second locking projection are coupled to the divided retainer. The first locking projection is formed by connecting the divided retainer to the small-diameter projection of the first locking projection and the small-diameter projection of the second locking projection. It arrange | positions in a small diameter hole and a 2nd small diameter hole, the 1st cyclic | annular locking surface part of a 1st latching protrusion is arrange | positioned facing a 1st latching step part, and the 2nd annular latch of a 2nd latching protrusion The first feature is that the surface portion is disposed opposite to the second locking step portion.
[0020]
In addition to the first feature, the present invention has a second feature that a coupling ring is fitted and arranged on the outer periphery of the coupled retainer.
[0021]
Furthermore, in addition to the first feature, the third feature of the present invention is that the outer diameter of the cored bar is larger than the outer diameter of each small-diameter protrusion.
[0022]
【Example】
Hereinafter, an embodiment of the negative pressure fuel valve according to the present invention will be described. The diaphragm assembly Df differs between the present invention and the conventional one. Only a different configuration will be described, and the same components are denoted by the same reference numerals as those of the prior art, and description thereof will be omitted. The fuel diaphragm 4 will be described with reference to FIG. FIG. 1 shows a main part of the fuel diaphragm 4. A metal core 9 is integrally disposed in the first locking protrusion 4C of the fuel diaphragm 4. The metal core 9 is formed of a rigid material having a hardness higher than that of a rubber material such as a metal material or a synthetic resin material, and is disposed at least in the large-diameter protrusion 4E. Specifically, the metal core 9 has a diameter G smaller than the outer diameter F of the large-diameter protrusion 4E, and is integrally formed in the first locking protrusion 4C when the fuel diaphragm 4 is formed from a rubber material. Arranged. In the present embodiment, a part of the cored bar 9 is disposed so as to enter the small-diameter protrusion 4D.
[0023]
The negative pressure diaphragm 5 will be described with reference to FIG. FIG. 2 shows a main part of the negative pressure diaphragm 5. A metal core 9 is integrally disposed in the second locking projection 5B of the negative pressure diaphragm 5. The metal core 9 is formed of a rigid material having a hardness higher than that of a rubber material such as a metal material or a synthetic resin material, and is disposed at least in the large-diameter protrusion 5D. Specifically, the metal core 9 has a diameter G smaller than the outer diameter F of the large-diameter protrusion 5D, and is integrally formed in the second locking protrusion 5B when the negative pressure diaphragm 5 is formed from a rubber material. To be placed. In the present embodiment, a part of the cored bar 9 is disposed so as to enter the small-diameter protrusion 5C.
[0024]
Next, the retainer 12 will be described with reference to FIGS. The retainer 12 is divided into two parts 12A and 12B along the longitudinal axis XX, and the two divided retainers 12A and 12B are combined to form a single retainer 12. In order to facilitate the description, the description will be given in a state where the retainers 12A and 12B are joined to form a single retainer 12. The retainer 12 is made of a rigid material such as aluminum or synthetic resin, and is formed as follows. The retainer 12 has a cylindrical shape, and a large-diameter hole 12C having a diameter larger than the outer diameter F of the large-diameter protrusions 4E and 5D of the first locking protrusion 4C and the second locking protrusion 5B at the center thereof. Is drilled along the longitudinal axis direction XX, and further through the first annular locking step portion 12D formed on one side A of the large diameter hole 12C, the first small diameter hole toward the one side A 12E is opened and formed. A second small diameter hole 12G is formed to open toward the other side B via a second annular locking step portion 12F formed on the other side B of the large diameter hole 12C. The diameters of the first small diameter hole 12E and the second small diameter hole 12G have such diameters that the small diameter protrusion 4D of the first locking protrusion 4C and the small diameter protrusion 5C of the second locking protrusion 5B can be inserted and held. It is selected and has a smaller diameter than the large diameter hole 12C. A coupling hole 12J is formed in the dividing surface 12H of the lower retainer 12B to be divided, and a coupling protrusion 12L fitted into the coupling hole 12J in the dividing surface 12K of the upper retainer 12A to be divided. Is formed protruding. That is, the lower retainer 12B and the upper retainer 12A are brought into contact with each other by bringing the dividing surface 12H of the lower retainer 12B into contact with the dividing surface 12K of the upper retainer 12A and fitting the coupling protrusion 12L into the coupling hole 12J. Combined, an integral retainer 12 can be formed. If the coupling hole 12J and the coupling protrusion 12L are fitted with a compression allowance, the retainers 12A and 12B can be firmly coupled. Further, the connecting means for the upper retainer 12A and the lower retainer 12B may be selected as appropriate, and is not limited to the above-described connecting method. For example, an adhesive may be used.
[0025]
The diaphragm assembly Df is assembled as follows. A small-diameter projection 5C of the second locking projection 5B of the negative pressure diaphragm 5 is disposed in the semi-circular second small-diameter hole 12G of the divided lower retainer 12B, and the second locking projection 5B is large. The radial protrusion 5D is disposed in the large-diameter hole 12C having a semicircular shape. At this time, the second annular locking surface portion 5E of the second locking projection 5B is disposed in contact with the second annular locking step portion 12F that forms a semicircle. Further, the small-diameter projection 4D of the first locking projection 4C of the fuel diaphragm 4 is disposed in the semi-circular first small-diameter hole 12E, and the large-diameter projection 4E of the first locking projection 4C is semicircular. It arrange | positions in the large diameter hole 12C made. At this time, the first annular locking surface portion 4F of the first locking protrusion 4C is disposed in contact with the first annular locking step portion 12D forming a semicircle.
[0026]
Then, the dividing surface 12K of the upper retainer 12A is arranged facing the dividing surface 12H of the lower retainer 12B in the above state. At this time, the second small-diameter hole 12G forming the semicircular shape of the upper retainer 12A is formed. A large-diameter projection 5D of the second locking projection 5B is arranged facing the small-diameter projection 5C of the second locking projection 5B of the negative pressure diaphragm 5 and a large-diameter hole 12C having a semicircular shape. The second annular locking surface portion 5E of the second locking projection 5B is arranged facing the semicircular second annular locking step portion 12F. On the other hand, the semi-circular first small-diameter hole 12E of the upper retainer 12A is disposed facing the small-diameter protrusion 4D of the first locking protrusion 4C of the fuel diaphragm 4, and faces the semi-circular large-diameter hole 12C. The large-diameter protrusion 4E of the first locking protrusion 4C is arranged, and the first annular locking surface part 4F of the first locking protrusion 4C is arranged facing the first annular locking step part 12D forming a semicircle. The
[0027]
In this state, the dividing surface 12K of the upper retainer 12A is brought into contact with the dividing surface 12H of the lower retainer 12B, and the coupling protrusion 12L is fitted and disposed in the coupling hole 12J. According to the above, the lower retainer 12B and the upper retainer 12A are combined to form an integrated retainer 12, and the second locking projection 5B of the negative pressure diaphragm 5 is inserted into the large-diameter hole 12C of the retainer 12. The large-diameter projection 5D is disposed, the small-diameter projection 5C of the second locking projection 5B is disposed in the second small-diameter hole 12G, and is further opposed to the second annular locking step 12F. A second annular locking surface portion 5E of the stop protrusion 5B is disposed.
[0028]
On the other hand, the large-diameter protrusion 4E of the first locking protrusion 4C of the fuel diaphragm 4 is disposed in the large-diameter hole 12C of the retainer 12, and the small-diameter protrusion of the first locking protrusion 4C is disposed in the first small-diameter hole 12E. 4D is arranged, and further, the first annular locking surface portion 4F of the first locking projection 4C is arranged facing the first annular locking step portion 12D. As described above, the negative pressure diaphragm 5 and the fuel diaphragm 4 are joined by the retainer 12. This diaphragm assembly Df is shown in FIG.
[0029]
In the diaphragm assembly Df, the fuel diaphragm 4 is sandwiched between the flat surface 1B of the valve main body 1 and the one side flat surface 2B of the atmospheric chamber body 2, and the negative pressure diaphragm 5 is the atmospheric chamber main body. 2 is sandwiched between the other flat surface 2A and the flat surface 3A of the negative pressure chamber body 3.
[0030]
Thus, when the negative pressure diaphragm 5 moves according to the negative pressure introduced into the negative pressure chamber 3B via the negative pressure introduction path 3C, this movement is transmitted to the fuel diaphragm 4 via the retainer 6. The fuel diaphragm 4 is moved in synchronization with the negative pressure diaphragm 5, whereby the valve portion 4B controls the opening and closing of the fuel valve seat 1D in accordance with the negative pressure in the negative pressure chamber 3B.
[0031]
According to the negative pressure type fuel valve of the present invention described above, since the rigid cored bar 9 is disposed in at least the large-diameter projection 5D of the negative pressure diaphragm 5, the negative pressure diaphragm 5 is exposed to a high temperature state and is rubber. Even if the material is softened, the outer diameter F of the large-diameter projection 5D is prevented from being greatly reduced inward. This is because the cored bar 9 is disposed at least inward of the large-diameter projection 5D to suppress the movement of rubber inward of the large-diameter projection 5D. In addition, since the rigid metal core 9 is disposed in at least the large-diameter protrusion 4E of the fuel diaphragm 4, even if the fuel diaphragm 4 is exposed to a high temperature state and the rubber material is softened, the outer diameter of the large-diameter protrusion 4E is increased. The diameter F is prevented from being greatly reduced inward. This is because the metal core 9 is disposed at least inward of the large-diameter protrusion 4E to suppress the movement of rubber inward of the large-diameter protrusion 4E. As described above, the outer diameter F of the large-diameter protrusion 4E of the first locking protrusion 4C and the large-diameter protrusion 5D of the second locking protrusion 5B is prevented from being reduced inward. Even if the negative pressure type fuel valve is exposed to a high temperature state for a long time, the large-diameter projections 5D and 4E do not escape from the second small-diameter hole 12G and the first small-diameter hole 12E of the retainer 12. The opening / closing function of the valve portion 4B can be assured stably and reliably over a long period of time.
[0032]
Further, the retainer 12 is divided into two parts 12A and 12B, and in the divided state, after the large-diameter projections 5D and 4E are arranged in the large-diameter hole 12C of the retainer 12, the retainers divided into two parts 12A and 12B are joined. According to the single retainer 12, the large-diameter projections 5D and 4E can be arranged in the large-diameter hole 12C without the small-diameter holes 12G and 12E. 4C and the 2nd latching protrusion part 5B were able to be easily mounted in the retainer 12. In particular, the fact that the large-diameter projections 5D and 4E can be arranged in the large-diameter hole 12C without passing through the small-diameter holes 12G and 12E means that the annular locking surface portions 4F and 5E of the diaphragms 4 and 5 and the annular engagement of the retainer 12 The contact allowance (hooking allowance) with the stop portions 12F and 12D can be increased, and the connection between the retainer 12 and the locking projections 4C and 5B of the diaphragms 4 and 5 is made stronger and more reliable. It was something that could be done.
[0033]
Further, as shown in FIG. 9, when the annular coupling ring 13 is attached to the outer periphery of the retainer 12, the divided retainers 12A and 12B can be more firmly coupled. If a slit groove (not shown) is inserted in the coupling ring 13 along the longitudinal direction, the coupling ring 13 can be mounted on the outer periphery of the retainer 12 while increasing the width of the slit groove of the coupling ring 13. Workability can be improved.
[0034]
Furthermore, if the outer diameter G of the core metal 9 is equal to or larger than the outer diameter E of each of the small diameter protrusions 4D and 5C, the outer diameter F of each of the large diameter protrusions 4E and 5D is the outer diameter E of the small diameter protrusions 4D and 5C. It is never reduced below, so that the escape of the large-diameter protrusions 4E and 5D from the small-diameter holes 12G and 12E can be more reliably prevented.
[0035]
Furthermore, the rubber materials of the negative pressure diaphragm 5 and the fuel diaphragm 4 do not need to be changed at all from those of the conventional one. According to this, there is no adverse effect on the dynamic characteristics of each diaphragm, and the conventional smooth diaphragm movement is not caused. The characteristics can be maintained.
[0036]
【The invention's effect】
As described above, according to the negative pressure type fuel valve of the present invention, the fuel diaphragm and the negative pressure diaphragm are formed of a rubber material, and at least in the large-diameter projections of the first locking projection and the second locking projection. The cored bar made of a rigid material is integrally formed and disposed. On the other hand, the retainer has a large-diameter hole having a diameter larger than the outer diameter of the large-diameter protrusion, and a first annular locking step portion from the large-diameter hole. A first small-diameter hole that can hold the small-diameter protrusion toward one side through the second small-diameter hole, and a second small-diameter hole that can hold the small-diameter protrusion from the large-diameter hole to the other side via the second annular locking step. The retainer is further divided into two parts that can be joined along the longitudinal axis thereof, and the large-diameter projection of the first latching projection and the large-diameter projection of the second latching projection. The portion is disposed in a large-diameter hole formed by joining the divided retainers, and the small diameter of the first locking projection The first and second projections of the first locking projections are disposed in the first and second small-diameter holes formed by connecting the divided retainers. Since the annular locking surface portion is disposed opposite to the first locking step portion, and the second annular locking surface portion of the second locking protrusion is disposed opposite to the second locking step portion, the negative pressure fuel valve is in a high temperature state. Even if it is exposed to the above, the negative pressure diaphragm and the fuel diaphragm can be stably and reliably coupled and held by the retainer, and a reliable opening / closing function of the valve portion can be ensured for a long period of time.
[0037]
In addition, in the state where the retainer is divided, the large-diameter projections and the small-diameter projections of the fuel and the negative pressure diaphragm are disposed in the large-diameter holes and small-diameter holes of the respective retainers. The fuel diaphragm and the negative pressure diaphragm can be coupled via the retainer by making an integral retainer in contact with each other, thereby greatly improving the workability of coupling the fuel diaphragm and the negative pressure diaphragm. The contact allowance between the annular locking surface portion and the annular locking step portion can be made large, and the connection between them can be made more reliably and firmly.
[0038]
Further, by attaching a coupling ring to the outer periphery of the coupled retainer, the divided retainers can be coupled more firmly.
[0039]
Furthermore, by setting the outer diameter of the cored bar to be equal to or larger than the outer diameter of the small-diameter protrusion, it is possible to further prevent each large-diameter protrusion from getting out of each small-diameter hole.
[Brief description of the drawings]
FIG. 1 is an enlarged longitudinal sectional view showing a main part of an embodiment of a fuel diaphragm used in a negative pressure fuel valve of the present invention.
FIG. 2 is an enlarged vertical cross-sectional view showing a main part of an embodiment of a negative pressure diaphragm used in the negative pressure fuel valve of the present invention.
FIG. 3 is a side view showing an embodiment of a retainer used in the negative pressure fuel valve of the present invention, and showing an integrated state in which the divided retainers are combined.
4 is a right side view of FIG. 3;
5 is a longitudinal sectional view taken along line JJ in FIG. 3. FIG.
6 is a longitudinal sectional view taken along the line KK in FIG. 4;
FIG. 7 is an enlarged longitudinal sectional view showing an embodiment of a diaphragm assembly used in the negative pressure fuel valve of the present invention.
FIG. 8 is a longitudinal sectional view showing an embodiment of a negative pressure fuel valve according to the present invention.
FIG. 9 is a longitudinal sectional view showing another embodiment of the negative pressure fuel valve of the present invention.
FIG. 10 is a longitudinal sectional view showing a conventional negative pressure fuel valve.
11 is an enlarged longitudinal sectional view of the diaphragm assembly used in FIG.
[Explanation of symbols]
4 Fuel diaphragm
4C 1st locking projection
4D small diameter protrusion
4E Large diameter protrusion
4F first annular locking surface
5 Negative pressure diaphragm
5B Second locking projection
5C small diameter protrusion
5D large diameter protrusion
5E Second annular locking surface
12 Retainer
12A, 12B Retainer divided
12C large diameter hole
12E 1st small hole
12G 2nd small hole
12D first locking step
12F Second locking step
13 Connecting ring

Claims

A valve body including a fuel inflow passage, a fuel outflow passage, and a fuel valve seat formed at a downstream end of the fuel inflow passage and facing a fuel chamber connected to the fuel outflow passage;
An atmospheric chamber body that faces the fuel chamber and is disposed on the valve body; a negative pressure chamber that faces the atmospheric chamber; a negative pressure chamber body that is disposed on the atmospheric chamber body; the valve body and the atmospheric chamber The fuel chamber is divided into a fuel chamber and an atmospheric chamber and is provided with a valve portion that opens and closes a fuel valve seat on the fuel chamber side, and a small-diameter projection, a large-diameter projection, and a small-diameter projection on the atmospheric chamber side. A fuel diaphragm having a first locking projection formed with a first annular locking surface formed between the large-diameter projection;
It is sandwiched between the atmospheric chamber main body and the negative pressure chamber main body and divided into an atmospheric chamber and a negative pressure chamber, and on the atmospheric chamber side, between the small diameter protrusion and the large diameter protrusion, and between the small diameter protrusion and the large diameter protrusion. A negative pressure diaphragm having a second locking projection formed of a second annular locking surface formed on
A retainer that is in the atmosphere chamber and that connects the first locking projection of the fuel diaphragm and the second locking projection of the negative pressure diaphragm, and synchronously connects the negative pressure diaphragm and the fuel diaphragm;
The fuel diaphragm 4 and the negative pressure diaphragm 5 are formed of a rubber material in a negative pressure type fuel valve that operates the fuel diaphragm according to the negative pressure introduced into the negative pressure chamber and controls the opening and closing of the fuel valve seat with the valve portion. At the same time, a cored bar 9 made of a rigid material is integrally formed and arranged in the large-diameter projections 4E and 5D of the first locking projection 4C and the second locking projection 5B. Is a large-diameter hole 12C having a diameter larger than the outer diameter F of the large-diameter protrusions 4E and 5D, and the small-diameter protrusion 4D from the large-diameter hole 12C toward the one side A via the first annular locking step 12D. A first small diameter hole 12E that can hold the small diameter protrusion 12C and a second small diameter hole 12G that can hold the small diameter protrusion 5C from the large diameter hole 12C to the other side B via the second annular locking step portion 12F. Furthermore, the retainer has a longitudinal axis X- The retainer 12A is formed by dividing the large-diameter protrusion 4E of the first locking protrusion 4C and the large-diameter protrusion 5D of the second locking protrusion 5B into two parts 12A and 12B that can be joined together. , 12B are arranged in a large-diameter hole 12C formed by joining, and the small-diameter projection 4D of the first locking projection 4C and the small-diameter projection 5C of the second locking projection 5B are divided into retainers. 12A and 12B are disposed in the first small diameter hole 12E and the second small diameter hole 12G formed by joining, and the first annular locking surface portion 4F of the first locking projection 4C is the first locking step portion. The negative pressure type fuel valve is arranged so as to face 12D, and the second annular locking surface portion 5E of the second locking projection 5B is arranged to face the second locking step portion 12F.

The negative pressure fuel valve according to claim 1, wherein a coupling ring (13) is fitted and disposed on the outer periphery of the coupled retainers (12A, 12B).

2. The negative pressure fuel valve according to claim 1, wherein the outer diameter G of the metal core is larger than the outer diameter E of each of the small diameter protrusions 4D and 5C.