JP3837300B2 - Positioning structure of air assist cap in fuel injection valve - Google Patents

Description

【０００１】
【発明の属する技術分野】
本発明は，主として内燃機関の燃料供給系に使用される燃料噴射弁に関し，特に，弁座及びその中心部を貫通する弁孔を有する弁座部材と，前記弁座と協働して前記弁孔を開閉する弁体と，前記弁孔に連通する複数の燃料噴孔を有して前記弁座部材の外端面に接合されるインジェクタプレートと，前記弁座部材の外周面に嵌装され，前記燃料噴孔からの噴射燃料が通過する誘導中空部及び，前記噴射燃料の微粒化を促進すべく前記誘導中空部にアシストエアを導入するアシストエア導入孔を有するエアアシストキャップとを備える燃料噴射弁において，エアアシストキャップの弁座部材に対する周方向位置を規定するようにした，エアアシストキャップの位置決め構造に関する。
【０００２】
【従来の技術】
かゝる燃料噴射弁において，インジェクタプレートの燃料噴孔からの噴射燃料に，アシストエア導入孔からのアシストエアを吹きつける際，その吹きつけ方向が変わることは，燃料噴霧パターンを変化させることになり，好ましくない。
【０００３】
そこで，燃料噴孔に対するアシストエア導入孔の位置関係を一定に保つために，例えば特開９−１４０８９号公報に開示されているように，インジェクタプレート及びエアアシストキャップの対向周面に，互いに係合してエアアシストキャップのインジェクタプレートに対する周方向位置を決定する位置決め係合部を形成することが既に知られている。
【０００４】
【発明が解決しようとする課題】
しかしながら，インジェクタプレートの板厚は，一般に０．１〜０．２５ｍｍと極めて薄いため，上記の従来構造では，位置決め強度が極めて弱く，燃料噴射弁をエンジンの取り付け孔へ捩じりながら着脱する際，上記位置決め係合部は，捩じりトルクにより破損してしまい，本来の位置決め機能を果たせなくなる虞がある。
【０００５】
本発明は，かゝる事情に鑑みてなされたもので，位置決め強度が高く，燃料噴孔に対するアシストエア導入孔の位置を一定に正確に保つことを可能にする，燃料噴射弁におけるエアアシストキャップの位置決め構造を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記目的を達成するために，本発明は，弁座及びその中心部を貫通する弁孔を有する弁座部材と，前記弁座と協働して前記弁孔を開閉する弁体と，前記弁孔に連通する複数の燃料噴孔を有して前記弁座部材の外端面に接合されるインジェクタプレートと，前記弁座部材の外周面に嵌装され，前記燃料噴孔からの噴射燃料が通過する誘導中空部及び，前記噴射燃料の微粒化を促進すべく前記誘導中空部にアシストエアを導入するアシストエア導入孔を有する合成樹脂製のエアアシストキャップとを備える燃料噴射弁において，
前記弁座部材の円筒状外周面に外向き位置決め平面を形成する一方，前記エアアシストキャップの円筒状内周面に，前記外向き位置決め平面に重なって該キャップの弁座部材に対する周方向位置を決定する内向き位置決め平面を形成すると共に、
前記弁座部材及びエアアシストキャップの互いに嵌合する嵌合面の一方及び他方に，互いに係合して前記弁座部材及びエアアシストキャップを相互に軸方向に連結する抜け止め溝及び抜け止め突起をそれぞれ形成し，前記エアアシストキャップの弁座部材への嵌合時には，これら抜け止め溝及び抜け止め突起の係合に先立ち，前記外向き位置決め平面及び内向き位置決め平面の重なりが開始するようにしたことを第１の特徴とする。
【０００７】
この第１の特徴によれば，弁座部材の外向き位置決め平面及びエアアシストキャップの内向き位置決め平面には充分に広い面積を付与して，弁座部材及びエアアシストキャップの位置決め強度を高めることができ，したがって，燃料噴射弁の吸気マニホールドへの嵌装時，燃料噴射弁を捩じっても，エアアシストキャップの位置ずれを確実に防ぐことができる。また，弁座部材及びエアアシストキャップを，抜け止め溝及び抜け止め突起の係合により軸方向に強力に連結することができる。しかもエアアシストキャップの弁座部材への嵌合時には，外向き位置決め平面及び内向き位置決め平面の重なりと，環状の抜け止め溝及び抜け止め突起の係合とを互いに干渉させることなく的確に行うことができ，エアアシストキャップの装着性が良好である。さらに，エアアシストキャップを合成樹脂製とすることにより，エアアシストキャップ自体の弾性を有効に利用して，抜け止め溝及び抜け止め突起の係合を容易に行うことができ，エアアシストキャップの装着性の向上に寄与し得る。
【０００８】
また本発明は，第１の特徴に加えて，前記外向き位置決め平面及び内向き位置決め平面を，前記弁座部材及びエアアシストキャップの各直径線上で対向する位置にそれぞれ一対設けたことを第２の特徴とする。
【０００９】
この第２の特徴によれば，外向き位置決め平面及び内向き位置決め平面の面積を極力広くして，位置決め強度の強化を効果的に図ることができる。
【００１０】
【発明の実施の形態】
本発明の実施の形態を，添付図面に示す本発明の実施例に基づいて以下に説明する。
【００１１】
図１は本発明の電磁式燃料噴射弁を装着した内燃機関の要部縦断平面図，図２は図１の２−２線断面図，図３は図２の３部拡大図，図４は図３の４矢視図，図５は図３の５−５線断面図である。
【００１２】
先ず，図１において，内燃機関Ｅのシリンダヘッド５０に下流側を左右二股に分岐させた吸気ポート５２が設けられており，その下流端に形成された左右一対の吸気弁座５２ａ，５２ｂと協働して吸気ポート５２を開閉する左右一対の吸気弁５３ａ，５３ｂがシリンダヘッド５０に装着される。このシリンダヘッド５０の一側面には，吸気ポート５２に連なる吸気路５５を有する吸気マニホールド５１が結合され，前記両吸気弁座５２ａ，５２ｂに向かう一対の燃料噴霧フォームＦａ，Ｆｂを形成すべく燃料を噴射する電磁式燃料噴射弁Ｉがこの吸気マニホールド５１に取り付けられる。
【００１３】
図２〜図５を参照しながら上記電磁式燃料噴射弁Ｉについて説明する。
【００１４】
図２及び図３に示すように，電磁式燃料噴射弁Ｉのケーシング１は，円筒状の弁ハウジング２（磁性体）と，この弁ハウジング２の前端部に液密に結合される有底円筒状の弁座部材３と，弁ハウジング２の後端に環状スペーサ４を挟んで液密に結合される円筒状の固定コア５とから構成される。
【００１５】
環状スペーサ４は，非磁性金属，例えばステンレス鋼製であり，その両端面に弁ハウジング２及び固定コア５が突き当てられて液密に全周溶接される。
【００１６】
弁座部材３及び弁ハウジング２の対向端部には，第１嵌合筒部３ａ及び第２嵌合筒部２ａがそれぞれ形成される。そして第１嵌合筒部３ａが第２嵌合筒部２ａ内にストッパプレート６と共に圧入され，ストッパプレート６は，弁ハウジング２と弁座部材３間で挟持される。第１及び第２嵌合筒部３ａ，２ａの嵌合後は，第１嵌合筒部２ａから露出した第１嵌合筒部３ａの外周面と第２嵌合筒部２ａの端面とに挟まれる環状隅部の全周に渡りレーザビーム溶接が施され，これにより弁ハウジング２及び弁座部材３が相互に液密に結合される。
【００１７】
弁座部材３は，その前端面に開口する弁孔７と，この弁孔７の内端に連なる円錐状の弁座８と，この弁座８の大径部に連なる円筒状のガイド孔９とを備えており，そのガイド孔９は前記第２嵌合筒部２ａと同軸状に形成される。
【００１８】
図３及び図４に示すように，弁座部材３の前端面には鋼板製のインジェクタプレート１０が液密に全周溶接される。弁座部材３の，インジェクタプレート１０との対向面には，弁孔７を中心とする円形で浅い凹部４０が形成されており，これが弁座部材３及びインジェクタプレート１０間の燃料拡散室４１を構成する。またこのインジェクタプレート１０には，この燃料拡散室４１に開口する複数個の燃料噴孔，図示例では上下一対，左右２組の燃料噴孔１１ａ，１１ｂが穿設されており，左側２個の燃料噴孔１１ａから噴射される燃料によって，左側の前記吸気弁座５２ａに向かう燃料噴霧フォームＦａ（図１参照）が形成され，右側２個の燃料噴孔１１ｂから噴射される燃料によって，右側の前記吸気弁座５２ｂに向かう燃料噴霧フォームＦｂ（図１参照）が形成される。
【００１９】
再び図２及び図３において，弁ハウジング２及び環状スペーサ４内には，固定コア５の前端面に対向する可動コア１２が収容され，この可動コア１２は環状スペーサ４の内周面によって軸方向摺動自在に支承される。
【００２０】
可動コア１２は，その一端面から前記弁座８側に延びる小径の杆部１５を一体に備えており，この杆部１５の先端に，前記弁座８に着座し得る球状の弁部１６が溶接により固着される。これら可動コア１２，杆部１５及び弁部１６によって弁体１４が構成される。
【００２１】
弁部１６は，前記ガイド孔９に軸方向摺動自在に支承されるもので，その外周面には，ガイド孔９内での燃料の流通を可能にする複数の面取り部１７が等間隔に並べて形成される。
【００２２】
前記ストッパプレート６には，杆部１５が貫通する切欠き１８が設けられており，このストッパプレート６の，弁座８側端面に対向するストッパフランジ１９が杆部１５の中間部に形成されている。これらストッパプレート６及びストッパフランジ１９間には，弁部１６の閉弁時，即ち弁座８への着座時，弁部１６の開弁ストロークに対応する間隙ｇが設けられる。
【００２３】
一方，固定コア５及び可動コア１２間には，弁部１６の閉弁時，即ち弁部１６の弁座８への着座時でも，両コア５，１２の当接を避けるに足る間隙が設けられる。
【００２４】
固定コア５は，可動コア１２の通孔２０を介して弁ハウジング２内と連通する中空部２１を有しており，その中空部２１に，可動コア１２を弁部１６の閉じ方向，即ち弁座８への着座方向に付勢するコイル状の弁ばね２２と，この弁ばね２２の後端を支承するパイプ状のリテーナ２３とが収容される。その際，弁ばね２２のセット荷重は，リテーナ２３の中空部２１への圧入深さによって調整される。
【００２５】
固定コア５の後端には，パイプ状のリテーナ２３を介して固定コア５の中空部２１に連通する燃料入口２５を持つ入口筒２６が一体に連設され，その燃料入口２５に燃料フィルタ２７が装着される。
【００２６】
環状スペーサ４及び固定コア５の外周にはコイル組立体２８が嵌装される。このコイル組立体２８は，環状スペーサ４及び固定コア５の外周面に嵌合するボビン２９と，これに巻装されるコイル３０とからなっており，このコイル組立体２８を囲繞するコイルハウジング３１の一端部が弁ハウジング２の外周面に溶接により結合される。
【００２７】
コイルハウジング３１，コイル組立体２８及び固定コア５は合成樹脂製の被覆体３２内に埋封され，この被覆体３２の中間部には，前記コイル３０に連なる接続端子３３を備えたカプラ３４が一体に連設される。
【００２８】
燃料噴射弁Ｉは，吸気マニホールド５１への取り付け時，例えば上記カプラ３４を吸気マニホールド５１の外周面と正反対側を向くように配置して，吸気マニホールド５１に対する周方向位置が一定に設定される。このとき，インジェクタプレート１０の左側の一対の燃料噴孔１１ａが左側の前記吸気弁座５２ａを指向し，右側の一対の燃料噴孔１１ｂが右側の前記吸気弁座５２ｂを指向するよう，インジェクタプレート１０は予め定位置に配置される。
【００２９】
即ち，図４に示すように，インジェクタプレート１０の外周には，９０°の位相差をもって位置決め用の小切欠き４０ａ及び大切欠き４０ｂが形成され，小切欠き４０ａを通るインジェクタプレート１０の直径線Ａを境にして，各組の燃料噴孔１１ａ，１１ｂが穿設される。そして，インジェクタプレート１０を弁座部材３の端面に溶接するとき，弁座部材３の端面を正面に見て，大切欠き４０ｂを小切欠き４０ａの左側に配置しながら小切欠き４０ａをカプラ３４の位相に合致させる。こうすれば，燃料噴射弁Ｉを吸気マニホールド５１の定位置に取り付けたとき，インジェクタプレート１０の表裏を間違えることなく，左右の組の燃料噴孔１１ａ，１１ｂを左右の吸気弁座５２ａ，５２ｂに指向させることができる。
【００３０】
図３及び図５において，弁ハウジング２の前端から露出した弁座部材３の外周には，弁座部材３の前端面に連なる小径円筒面４３と，この小径円筒面４３の後端に連なる環状の抜け止め溝４４と，この抜け止め溝４４の後端に連なる大径円筒面４５とが形成される。大径円筒面４５は小径円筒面４３より大径になっており，この大径円筒面４５の直径線上で対向する部分は切除されて一対の外向き位置決め平面４６に形成され，各外向き位置決め平面４６は，小径円筒面４３より半径方向外方に位置する。
【００３１】
弁座部材３のこのような外周に合成樹脂製のエアアシストキャップ４９が嵌着される。このエアアシストキャップ４９の内周には，前記小径円筒面４３に対応する小径円筒面６０と，前記抜け止め溝４４に対応する環状の抜け止め突起６１と，前記大径円筒面４５に対応する大径円筒面６２と，前記外向き位置決め平面４６に対応する内向き位置決め平面６３とが形成される。このエアアシストキャップ４９の小径及び大径円筒面６０，６２は，前記弁座部材３の小径及び大径円筒面４３，４５に圧入されるよう，自由状態ではそれらよりも若干小径に形成され，その圧入時，内向き位置決め平面６３は外向き位置決め平面４６に重なってエアアシストキャップ４９の弁座部材３に対する周方向の位置決めを果たし，また抜け止め突起６１は抜け止め溝４４に係合してエアアシストキャップ４９の弁座部材３に対する軸方向の連結を果たす。
【００３２】
エアアシストキャップ４９の外周面には，一方の内向き位置決め平面６３との対応位置に，該内向き位置決め平面６３の位置を示す突起状の目印６４（図５参照）が形成される。したがって，内向き位置決め平面６３がエアアシストキャップ４９の外側からは目視できなくても，この目印６４を弁座部材３の外向き位置決め平面４６の位置に合わせながらエアアシストキャップ４９を弁座部材３に嵌合することにより，内向き位置決め平面６３を外向き位置決め平面４６に容易，確実に重ねることができる。
【００３３】
エアアシストキャップ４９の内周には，また，前記インジェクタプレート１０の前端面に密着する環状の段部６５と，この段部６５の内周縁に連なり，エアアシストキャップ４９の前端に向かって漸次拡径する誘導面６６とが形成される。この誘導面６６は，その内側に前記燃料噴霧フォームＦａ，Ｆｂを誘導する誘導中空部６７を画成するもので，この誘導中空部６７の下流側に向けてアシストエアを導入する上下一対のアシストエア導入孔６８，６８がエアアシストキャップ４９に穿設される。その際，一対のアシストエア導入孔６８，６８は，インジェクタプレート１０の小切欠き４０ａを通る直径線Ａ（図４参照）上で相対向するようになっている。また各アシストエア導入孔６８，６８の横断面は，エアアシストキャップ４９の軸線を中心とする円弧状をなしている。
【００３４】
エアアシストキャップ４９の後端に形成されたフランジ６９と，前記被覆体３２の前端面との間に環状のシール溝７０が画成され，この環状溝７２に大径のＯリング７１が装着される。またエアアシストキャップ４９の前端部外周に形成された小径で環状のシール溝７２には，小径のＯリング７３が装着される。
【００３５】
一方，図３において，燃料噴射弁Ｉの取り付けのために吸気マニホールド５１に設けられる取り付け孔８０は，小径部８０ａ，大径部８０ｂ及び，それらを接続するテーパ部８０ｃとからなっており，そのテーパ部８０ｃにアシストエア通路８１が開口する。
【００３６】
而して，取り付け孔８０にエアアシストキャップ４９を嵌装すると，取り付け孔８０の大径部８０ｂ及び小径部８０ａの内周面にエアアシストキャップ４９のＯリング７１，７３がそれぞれ密接すると共に，これらＯリング７１，７３間には，アシストエア通路８１及びアシストエア導入孔６８間を連通する環状通路８２が形成される。
【００３７】
アシストエア通路８１の上流端は，吸気マニホールド５１の上流側に結合される図示しないスロットルボディ内の吸気道の，スロットルバルブより上流部に接続される。したがって，内燃機関Ｅの作動時，吸気負圧の作用により，スロットルボディ内の吸気道の上流側の空気がアシストエア通路８１，環状通路８２及びアシストエア導入孔６８，６８を通して，誘導中空部６７に導入されるようになっている。
【００３８】
次に，この実施例の作用について説明する。
【００３９】
図２に示すように，コイル３０を消磁した状態では，弁ばね２２の付勢力で弁体１４が前方に押圧され，弁部１６を弁座８に着座させている。したがって，図示しない燃料ポンプから燃料フィルタ２７及び入口筒２６を通して弁ハウジング２内に供給された高圧燃料は，弁ハウジング２内に待機させられる。
【００４０】
コイル３０を通電により励磁すると，それにより生ずる磁束が固定コア５，コイルハウジング３１，弁ハウジング２及び可動コア１２を順次走り，その磁力により可動コア１２が弁部１６と共に固定コア５に吸引され，弁座８が開放されるので，弁ハウジング２内の高圧燃料が弁部１６の面取り部１７を経て，弁孔７から燃料拡散室４１に移り，該室４１で高圧燃料は周囲に拡散しながら左右２組の燃料噴孔１１ａ，１１ｂに分配され，そしてエアアシストキャップ４９の誘導中空部６７を通して内燃機関Ｅの左右吸気弁座５２ａ，５２ｂ側に噴射され，燃料噴霧フォームＦａ，Ｆｂが形成される。これと同時に，一対のアシストエア導入孔６８，６８から誘導中空部６７にアシストエアが導入され，これらエアは両燃料噴霧フォームＦａ，Ｆｂに両側方から斜めに衝突して，燃料の霧化を促進するので，内燃機関Ｅの燃料室に燃料と吸入空気との良好な混合気を供給し得て，燃焼効率の向上を図ることができる。しかも，エアアシストキャップ４９の弁座部材３への位置決め装着により，アシストエアの両燃料噴霧フォームＦａ，Ｆｂへの衝突位置が一定しているから，量産される全ての内燃機関Ｅにおける燃料噴霧フォームＦａ，Ｆｂを一定形状に保持できて，燃焼の安定化を図ることができる。
【００４１】
ところで，エアアシストキャップ４９の弁座部材３に対する周方向の位置決めは，弁座部材３及びエアアシストキャップ４９の圧入嵌合面に形成された外向き位置決め平面４６及び内向き位置決め平面６３の重なりによって行われるので，両位置決め平面４６，６３には充分に広い面積を付与して，弁座部材３及びエアアシストキャップ４９相互の位置決め強度を高めることができる。したがって，燃料噴射弁Ｉの取り付け孔８０への嵌装時，燃料噴射弁Ｉを捩じっても，Ｏリング７１，７３と取り付け孔８０内周面との摩擦力に抗して，エアアシストキャップ４９を弁座部材３と共に回転させることができ，エアアシストキャップ４９の位置ずれを確実に防ぐことができる。
【００４２】
特に，この場合，外向き位置決め平面４６及び内向き位置決め平面６３は，一対のアシストエア導入孔６８，６８に対応してそれぞれ直径線で対向する一対設けられるので，エアアシストキャップ４９の弁座部材３への嵌合位置を２箇所とすることができて，エアアシストキャップ４９の装着性が良好となる上，各位置決め平面４６，６３の面積を極力広くして，位置決め強度の強化を効果的に図ることができる。
【００４３】
またエアアシストキャップ４９及び弁座部材３は，それらの嵌合面の圧入と，それら嵌合面に形成された環状の抜け止め溝４４及び抜け止め突起６１の係合とにより，軸方向に強力に連結される。エアアシストキャップ４９の弁座部材３への嵌合時には，外向き位置決め平面４６及び内向き位置決め平面６３の重なりと，環状の抜け止め溝４４及び抜け止め突起６１の係合とがその順で行われるので，外向き位置決め平面４６及び内向き位置決め平面６３の重なりと，環状の抜け止め溝４４及び抜け止め突起６１の係合とを互いに干渉させることなく的確に行うことができ，エアアシストキャップ４９の装着性が良好である。
【００４４】
さらにエアアシストキャップ４９は合成樹脂製であるから，それ自体の弾性を有効に利用して，弁座部材３への圧入，並びに抜け止め溝４４及び抜け止め突起６１の係合を容易に行うことができ，エアアシストキャップ４９の装着性の向上に寄与し得る。
【００４５】
本発明は上記実施例に限定されるものではなく，その要旨を逸脱しない範囲で種々の設計変更が可能である。
【００４６】
【発明の効果】
以上のように本発明の第１の特徴によれば，弁座及びその中心部を貫通する弁孔を有する弁座部材と，前記弁座と協働して前記弁孔を開閉する弁体と，前記弁孔に連通する複数の燃料噴孔を有して前記弁座部材の外端面に接合されるインジェクタプレートと，前記弁座部材の外周面に嵌装され，前記燃料噴孔からの噴射燃料が通過する誘導中空部及び，前記噴射燃料の微粒化を促進すべく前記誘導中空部にアシストエアを導入するアシストエア導入孔を有する合成樹脂製のエアアシストキャップとを備える燃料噴射弁において，前記弁座部材の円筒状外周面に外向き位置決め平面を形成する一方，前記エアアシストキャップの円筒状内周面に，前記外向き位置決め平面に重なって該キャップの弁座部材に対する周方向位置を決定する内向き位置決め平面を形成すると共に、前記弁座部材及びエアアシストキャップの互いに嵌合する嵌合面の一方及び他方に，互いに係合して前記弁座部材及びエアアシストキャップを相互に軸方向に連結する抜け止め溝及び抜け止め突起をそれぞれ形成し，前記エアアシストキャップの弁座部材への嵌合時には，これら抜け止め溝及び抜け止め突起の係合に先立ち，前記外向き位置決め平面及び内向き位置決め平面の重なりが開始するようにしたので，弁座部材の外向き位置決め平面及びエアアシストキャップの内向き位置決め平面には充分に広い面積を付与して，弁座部材及びエアアシストキャップの位置決め強度を高めることができ，したがって，燃料噴射弁の吸入マニホールドへの嵌装時，燃料噴射弁を捩じっても，エアアシストキャップの位置ずれを確実に防ぐことができる。また，弁座部材及びエアアシストキャップを，抜け止め溝及び抜け止め突起の係合により軸方向に強力に連結することができる。しかもエアアシストキャップの弁座部材への嵌合時には，外向き位置決め平面及び内向き位置決め平面の重なりと，環状の抜け止め溝及び抜け止め突起の係合とを互いに干渉させることなく的確に行うことができ，エアアシストキャップの装着性が良好である。さらに前記エアアシストキャップを合成樹脂製としたので，エアアシストキャップ自体の弾性を有効に利用して，抜け止め溝及び抜け止め突起の係合を容易に行うことができ，エアアシストキャップの装着性の向上に寄与し得る。
【００４７】
また本発明の第２の特徴によれば，第１の特徴に加えて，前記外向き位置決め平面及び内向き位置決め平面を，前記弁座部材及びエアアシストキャップの各直径線上で対向する位置にそれぞれ一対設けたので，外向き位置決め平面及び内向き位置決め平面の面積を極力広くして，位置決め強度の強化を効果的に図ることができる。
【図面の簡単な説明】
【図１】 本発明の電磁式燃料噴射弁を装着した内燃機関の要部縦断平面図。
【図２】 図１の２−２線断面図。
【図３】 図２の３部拡大図。
【図４】 図３の４矢視図。
【図５】 図３の５−５線断面図。
【符号の説明】
Ｉ・・・・・燃料噴射弁
３・・・・・弁座部材
４・・・・・弁体
７・・・・・弁孔
８・・・・・弁座
１０・・・・インジェクタプレート
１１ａ，１１ｂ・・・燃料噴孔
１４・・・・弁体
４４・・・・抜け止め溝
４６・・・・外向き位置決め平面
４９・・・・エアアシストキャップ
６１・・・・抜け止め突起
６３・・・・内向き位置決め平面
６７・・・・誘導中空部
６８・・・・アシストエア導入孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection valve mainly used in a fuel supply system of an internal combustion engine, and in particular, a valve seat member having a valve seat and a valve hole penetrating the central portion thereof, and the valve seat in cooperation with the valve seat. A valve body that opens and closes a hole, an injector plate that has a plurality of fuel injection holes communicating with the valve hole and is joined to an outer end surface of the valve seat member, and is fitted to an outer peripheral surface of the valve seat member; Fuel injection comprising: an induction hollow portion through which the injected fuel from the fuel injection hole passes; and an air assist cap having an assist air introduction hole for introducing assist air into the induction hollow portion to promote atomization of the injected fuel. The present invention relates to a positioning structure for an air assist cap that defines a circumferential position of the air assist cap with respect to a valve seat member.
[0002]
[Prior art]
In such a fuel injection valve, when the assist air from the assist air introduction hole is sprayed onto the fuel injected from the fuel injection hole of the injector plate, the direction of the spray change changes the fuel spray pattern. It is not preferable.
[0003]
Therefore, in order to keep the positional relationship of the assist air introduction hole with respect to the fuel injection hole constant, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-14089, the opposing peripheral surfaces of the injector plate and the air assist cap are mutually engaged. It is already known to form a positioning engagement portion that determines the circumferential position of the air assist cap with respect to the injector plate.
[0004]
[Problems to be solved by the invention]
However, since the plate thickness of the injector plate is generally very thin at 0.1 to 0.25 mm, the positioning strength is extremely weak in the above-described conventional structure, and when the fuel injection valve is twisted into the mounting hole of the engine, it is removed. The positioning engagement portion may be damaged by torsional torque, and the original positioning function may not be performed.
[0005]
The present invention has been made in view of such circumstances, and has a high positioning strength and an air assist cap in a fuel injection valve that makes it possible to keep the position of the assist air introduction hole with respect to the fuel injection hole constant and accurate. An object of the present invention is to provide a positioning structure.
[0006]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a valve seat member having a valve seat and a valve hole penetrating through a central portion thereof, a valve body for opening and closing the valve hole in cooperation with the valve seat, and the valve An injector plate having a plurality of fuel injection holes communicating with the holes and joined to an outer end surface of the valve seat member; and fitted to an outer peripheral surface of the valve seat member, through which the injected fuel from the fuel injection hole passes. A fuel injection valve comprising: an induction hollow portion that includes a synthetic resin air assist cap having an assist air introduction hole that introduces assist air into the induction hollow portion so as to promote atomization of the injected fuel;
An outward positioning plane is formed on the cylindrical outer peripheral surface of the valve seat member, and a circumferential position of the cap with respect to the valve seat member is overlapped on the cylindrical inner peripheral surface of the air assist cap so as to overlap the outward positioning plane. Forming an inward positioning plane to determine ,
A retaining groove and a retaining projection for engaging the valve seat member and the air assist cap in the axial direction with each other on one and the other of the fitting surfaces of the valve seat member and the air assist cap. When the air assist cap is fitted to the valve seat member, the outward positioning plane and the inward positioning plane start to overlap prior to the engagement of the retaining groove and the retaining protrusion. This is the first feature.
[0007]
According to the first feature, a sufficiently large area is given to the outward positioning plane of the valve seat member and the inward positioning plane of the air assist cap, thereby increasing the positioning strength of the valve seat member and the air assist cap. can be, therefore, HamaSoji to inspiratory manifold fuel injection valve, even twisted fuel injection valve, it is possible to reliably prevent positional deviation of the air-assisted cap. Further, the valve seat member and the air assist cap can be strongly connected in the axial direction by the engagement of the retaining groove and the retaining protrusion. In addition, when the air assist cap is fitted to the valve seat member, the overlap of the outward positioning plane and the inward positioning plane and the engagement of the annular retaining groove and the retaining projection should be accurately performed without interfering with each other. The air assist cap is easy to wear. In addition, by making the air assist cap made of synthetic resin, it is possible to easily engage the retaining groove and the retaining protrusion by effectively utilizing the elasticity of the air assist cap itself. It can contribute to the improvement of sex.
[0008]
The present invention, in addition to the first feature, the outward positioning plane and the inward positioning plane, wherein the valve seat member and the air-assisted second that each opposite positions provided a pair in each diameter line of the cap It is characterized by.
[0009]
With the second feature, the area of the outward positioning plane and inwardly positioned flat and as wide as possible, Ru can strengthen the positioning strength effectively.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.
[0011]
Figure 1 is a fragmentary longitudinal plan view of an internal combustion engine equipped with a electromagnetic fuel injection valve of the present invention, FIG. 2 is sectional view taken along line 2-2 of FIG. 1, FIG. 3 is 3 parts enlarged view of FIG. 2, FIG. 4 4 is a cross-sectional view taken along line 4-5 in FIG.
[0012]
First, in FIG. 1, a cylinder head 50 of the internal combustion engine E is provided with an intake port 52 having a downstream branching bifurcated left and right, and cooperates with a pair of left and right intake valve seats 52a and 52b formed at the downstream end thereof. A pair of left and right intake valves 53 a and 53 b that work to open and close the intake port 52 are mounted on the cylinder head 50. An intake manifold 51 having an intake passage 55 connected to the intake port 52 is coupled to one side surface of the cylinder head 50, and a fuel is formed to form a pair of fuel spray foams Fa and Fb toward both the intake valve seats 52a and 52b. Is attached to the intake manifold 51.
[0013]
The electromagnetic fuel injection valve I will be described with reference to FIGS.
[0014]
As shown in FIGS. 2 and 3, the casing 1 of the electromagnetic fuel injection valve I includes a cylindrical valve housing 2 (magnetic material) and a bottomed cylinder that is liquid-tightly coupled to the front end of the valve housing 2. And a cylindrical fixed core 5 that is liquid-tightly coupled with an annular spacer 4 at the rear end of the valve housing 2.
[0015]
The annular spacer 4 is made of a non-magnetic metal, for example, stainless steel, and the valve housing 2 and the fixed core 5 are abutted against both end surfaces of the annular spacer 4 so as to be welded in a liquid-tight manner.
[0016]
A first fitting tube portion 3a and a second fitting tube portion 2a are formed at opposite ends of the valve seat member 3 and the valve housing 2, respectively. The first fitting cylinder 3a is press-fitted together with the stopper plate 6 into the second fitting cylinder 2a, and the stopper plate 6 is sandwiched between the valve housing 2 and the valve seat member 3. After the first and second fitting tube portions 3a, 2a are fitted, the outer peripheral surface of the first fitting tube portion 3a exposed from the first fitting tube portion 2a and the end surface of the second fitting tube portion 2a Laser beam welding is performed over the entire circumference of the sandwiched annular corner, whereby the valve housing 2 and the valve seat member 3 are connected in a liquid-tight manner.
[0017]
The valve seat member 3 includes a valve hole 7 that opens to a front end surface thereof, a conical valve seat 8 that is continuous with the inner end of the valve hole 7, and a cylindrical guide hole 9 that is continuous with a large diameter portion of the valve seat 8. The guide hole 9 is formed coaxially with the second fitting cylinder portion 2a.
[0018]
As shown in FIGS. 3 and 4, a steel plate injector plate 10 is liquid-tightly welded to the front end surface of the valve seat member 3 in a liquid-tight manner. A circular shallow shallow recess 40 centered on the valve hole 7 is formed on the surface of the valve seat member 3 facing the injector plate 10, and this forms a fuel diffusion chamber 41 between the valve seat member 3 and the injector plate 10. Constitute. The injector plate 10 is provided with a plurality of fuel injection holes opened in the fuel diffusion chamber 41, in the illustrated example, a pair of upper and lower fuel injection holes 11a and 11b. A fuel spray form Fa (see FIG. 1) directed to the intake valve seat 52a on the left side is formed by the fuel injected from the fuel injection holes 11a, and the right side is determined by the fuel injected from the two right fuel injection holes 11b. A fuel spray foam Fb (see FIG. 1) is formed toward the intake valve seat 52b.
[0019]
2 and 3 again, a movable core 12 facing the front end surface of the fixed core 5 is accommodated in the valve housing 2 and the annular spacer 4, and the movable core 12 is axially moved by the inner peripheral surface of the annular spacer 4. It is slidably supported.
[0020]
The movable core 12 is integrally provided with a small-diameter flange 15 extending from one end surface thereof toward the valve seat 8, and a spherical valve section 16 that can be seated on the valve seat 8 is formed at the tip of the flange 15. It is fixed by welding. The movable core 12, the flange portion 15 and the valve portion 16 constitute a valve body 14.
[0021]
The valve portion 16 is supported in the guide hole 9 so as to be slidable in the axial direction, and a plurality of chamfered portions 17 that allow fuel to flow in the guide hole 9 are equidistantly arranged on the outer peripheral surface thereof. They are formed side by side.
[0022]
The stopper plate 6 is provided with a notch 18 through which the flange portion 15 passes, and a stopper flange 19 facing the end face of the stopper plate 6 on the valve seat 8 side is formed at an intermediate portion of the flange portion 15. Yes. A gap g corresponding to the valve opening stroke of the valve portion 16 is provided between the stopper plate 6 and the stopper flange 19 when the valve portion 16 is closed, that is, when seated on the valve seat 8.
[0023]
On the other hand, a gap is provided between the fixed core 5 and the movable core 12 to avoid contact between the cores 5 and 12 even when the valve portion 16 is closed, that is, when the valve portion 16 is seated on the valve seat 8. It is done.
[0024]
The fixed core 5 has a hollow portion 21 communicating with the inside of the valve housing 2 through the through hole 20 of the movable core 12, and the movable core 12 is closed in the hollow portion 21 in the closing direction of the valve portion 16, that is, the valve A coiled valve spring 22 that urges the seat 8 in the seating direction and a pipe-shaped retainer 23 that supports the rear end of the valve spring 22 are accommodated. At that time, the set load of the valve spring 22 is adjusted by the press-fitting depth of the retainer 23 into the hollow portion 21.
[0025]
An inlet cylinder 26 having a fuel inlet 25 communicating with the hollow portion 21 of the fixed core 5 through a pipe-shaped retainer 23 is integrally connected to the rear end of the fixed core 5, and a fuel filter 27 is connected to the fuel inlet 25. Is installed.
[0026]
A coil assembly 28 is fitted on the outer periphery of the annular spacer 4 and the fixed core 5. The coil assembly 28 includes a bobbin 29 fitted to the outer peripheral surfaces of the annular spacer 4 and the fixed core 5 , and a coil 30 wound around the bobbin 29, and a coil housing 31 surrounding the coil assembly 28. Is connected to the outer peripheral surface of the valve housing 2 by welding.
[0027]
The coil housing 31, the coil assembly 28, and the fixed core 5 are embedded in a cover 32 made of synthetic resin, and a coupler 34 having a connection terminal 33 connected to the coil 30 is provided at an intermediate portion of the cover 32. It is connected continuously.
[0028]
When the fuel injection valve I is attached to the intake manifold 51, for example, the coupler 34 is disposed so as to face the opposite side of the outer peripheral surface of the intake manifold 51, and the circumferential position with respect to the intake manifold 51 is set to be constant. At this time, the pair of fuel injection holes 11a on the left side of the injector plate 10 are directed to the intake valve seat 52a on the left side, and the pair of fuel injection holes 11b on the right side are directed to the intake valve seat 52b on the right side. 10 is previously arranged at a fixed position.
[0029]
That is, as shown in FIG. 4, a positioning notch 40a and an important notch 40b are formed on the outer periphery of the injector plate 10 with a phase difference of 90 °, and the diameter line of the injector plate 10 passing through the notch 40a. Each set of fuel injection holes 11a and 11b is formed with A as a boundary. When the injector plate 10 is welded to the end face of the valve seat member 3, the end face of the valve seat member 3 is viewed from the front, and the important notch 40b is disposed on the left side of the small notch 40a while the small notch 40a is coupled to the coupler 34. To match the phase of. In this way, when the fuel injection valve I is mounted at a fixed position of the intake manifold 51, the left and right sets of fuel injection holes 11a, 11b are connected to the left and right intake valve seats 52a, 52b without making a mistake in the front and back of the injector plate 10. Can be oriented.
[0030]
3 and 5, on the outer periphery of the valve seat member 3 exposed from the front end of the valve housing 2, a small diameter cylindrical surface 43 connecting the front end face of the valve seat member 3, with the rear end of the small diameter cylindrical surface 43 An annular retaining groove 44 and a large-diameter cylindrical surface 45 connected to the rear end of the retaining groove 44 are formed. The large-diameter cylindrical surface 45 has a larger diameter than the small-diameter cylindrical surface 43, and the opposing portions on the diameter line of the large-diameter cylindrical surface 45 are cut out to form a pair of outward positioning planes 46. The flat surface 46 is located radially outward from the small diameter cylindrical surface 43.
[0031]
An air assist cap 49 made of synthetic resin is fitted on the outer periphery of the valve seat member 3. The inner periphery of the air assist cap 49 corresponds to the small-diameter cylindrical surface 60 corresponding to the small-diameter cylindrical surface 43, the annular retaining protrusion 61 corresponding to the retaining groove 44, and the large-diameter cylindrical surface 45 . A large-diameter cylindrical surface 62 and an inward positioning plane 63 corresponding to the outward positioning plane 46 are formed. The small diameter and large diameter cylindrical surfaces 60, 62 of the air assist cap 49 are formed to have a slightly smaller diameter in the free state so as to be press-fitted into the small diameter and large diameter cylindrical surfaces 43, 45 of the valve seat member 3, At the time of the press-fitting, the inward positioning plane 63 overlaps the outward positioning plane 46 to perform the circumferential positioning of the air assist cap 49 with respect to the valve seat member 3, and the retaining protrusion 61 engages with the retaining groove 44. The air assist cap 49 is connected to the valve seat member 3 in the axial direction.
[0032]
On the outer peripheral surface of the air assist cap 49, a projecting mark 64 (see FIG. 5) indicating the position of the inward positioning plane 63 is formed at a position corresponding to one inward positioning plane 63. Therefore, even if the inward positioning plane 63 is not visible from the outside of the air assist cap 49, the air assist cap 49 is moved to the valve seat member 3 while aligning the mark 64 with the position of the outward positioning plane 46 of the valve seat member 3. So that the inward positioning plane 63 can be easily and reliably overlapped with the outward positioning plane 46.
[0033]
The inner periphery of the air assist cap 49 is also connected to the annular step portion 65 that is in close contact with the front end surface of the injector plate 10 and the inner periphery of the step portion 65, and gradually expands toward the front end of the air assist cap 49. A guiding surface 66 having a diameter is formed. The guide surface 66 defines a guide hollow portion 67 for guiding the fuel spray foams Fa and Fb on the inner side, and a pair of upper and lower assists for introducing assist air toward the downstream side of the guide hollow portion 67. Air introduction holes 68 are formed in the air assist cap 49. At this time, the pair of assist air introduction holes 68 and 68 are opposed to each other on a diameter line A (see FIG. 4) passing through the small notch 40a of the injector plate 10. Further, the cross section of each assist air introduction hole 68, 68 has an arc shape centered on the axis of the air assist cap 49.
[0034]
An annular seal groove 70 is defined between the flange 69 formed at the rear end of the air assist cap 49 and the front end surface of the covering body 32, and a large-diameter O-ring 71 is attached to the annular groove 72. The A small-diameter O-ring 73 is attached to a small-diameter annular seal groove 72 formed on the outer periphery of the front end portion of the air assist cap 49.
[0035]
On the other hand, in FIG. 3, the mounting hole 80 provided in the intake manifold 51 for mounting the fuel injection valve I is composed of a small diameter portion 80a, a large diameter portion 80b, and a tapered portion 80c connecting them. An assist air passage 81 opens in the tapered portion 80c.
[0036]
Thus, when the air assist cap 49 is fitted into the mounting hole 80, the O-rings 71 and 73 of the air assist cap 49 are in close contact with the inner peripheral surfaces of the large diameter portion 80b and the small diameter portion 80a of the mounting hole 80, respectively. An annular passage 82 communicating between the assist air passage 81 and the assist air introduction hole 68 is formed between the O-rings 71 and 73.
[0037]
The upstream end of the assist air passage 81 is connected to the upstream portion of the intake passage in the throttle body (not shown) coupled to the upstream side of the intake manifold 51 from the throttle valve. Therefore, when the internal combustion engine E is operated, the air on the upstream side of the intake passage in the throttle body passes through the assist air passage 81, the annular passage 82, and the assist air introduction holes 68 and 68 due to the action of the intake negative pressure. To be introduced.
[0038]
Next, the operation of this embodiment will be described.
[0039]
As shown in FIG. 2, when the coil 30 is demagnetized, the valve body 14 is pressed forward by the urging force of the valve spring 22, and the valve portion 16 is seated on the valve seat 8. Therefore, the high-pressure fuel supplied from the fuel pump (not shown) to the valve housing 2 through the fuel filter 27 and the inlet tube 26 is kept in the valve housing 2 .
[0040]
When the coil 30 is energized by energization, the magnetic flux generated by the coil 30 sequentially travels through the fixed core 5, the coil housing 31, the valve housing 2 and the movable core 12, and the movable core 12 is attracted to the fixed core 5 together with the valve portion 16 by the magnetic force. Since the valve seat 8 is opened, the high-pressure fuel in the valve housing 2 moves from the valve hole 7 to the fuel diffusion chamber 41 through the chamfered portion 17 of the valve portion 16, and the high-pressure fuel diffuses to the surroundings in the chamber 41. The fuel injection holes 11a and 11b are distributed to the left and right fuel injection holes 11a and 11b, and injected to the left and right intake valve seats 52a and 52b of the internal combustion engine E through the guide hollow portion 67 of the air assist cap 49, thereby forming fuel spray forms Fa and Fb. The At the same time, the assist air is introduced into the guide hollow portion 67 from the pair of assist air introduction holes 68, 68, and these air collide with both fuel spray foams Fa, Fb obliquely from both sides to atomize the fuel. As a result, the fuel mixture of the internal combustion engine E can be supplied with a good mixture of fuel and intake air, and the combustion efficiency can be improved. Moreover, since the position of the air assist cap 49 on the valve seat member 3 is positioned and fixed, the position of the collision of the assist air with the fuel spray foams Fa and Fb is constant. Therefore, the fuel spray foam in all mass-produced internal combustion engines E Fa and Fb can be held in a fixed shape, and combustion can be stabilized.
[0041]
By the way, the circumferential positioning of the air assist cap 49 with respect to the valve seat member 3 is performed by the overlap of the outward positioning plane 46 and the inward positioning plane 63 formed on the press-fitting fitting surface of the valve seat member 3 and the air assist cap 49. As a result, the positioning planes 46 and 63 can be provided with a sufficiently large area to increase the positioning strength between the valve seat member 3 and the air assist cap 49. Therefore, even when the fuel injection valve I is twisted when the fuel injection valve I is fitted into the mounting hole 80, the air assist is resisted against the frictional force between the O-rings 71 and 73 and the inner peripheral surface of the mounting hole 80. The cap 49 can be rotated together with the valve seat member 3, and the displacement of the air assist cap 49 can be reliably prevented.
[0042]
In particular, in this case, the outward positioning plane 46 and the inward positioning plane 63 are provided in a pair corresponding to the pair of assist air introduction holes 68 and 68 respectively in diameter lines, so that the valve seat member of the air assist cap 49 is provided. The fitting position of the air assist cap 49 can be improved, and the areas of the positioning planes 46 and 63 are made as wide as possible to effectively enhance the positioning strength. Can be aimed at.
[0043]
The air assist cap 49 and the valve seat member 3 are strong in the axial direction by press-fitting their fitting surfaces and engaging the annular retaining grooves 44 and retaining projections 61 formed on the fitting surfaces. Connected to When the air assist cap 49 is fitted to the valve seat member 3, the overlapping of the outward positioning plane 46 and the inward positioning plane 63 and the engagement of the annular retaining groove 44 and the retaining protrusion 61 are performed in that order. Therefore, the overlap of the outward positioning plane 46 and the inward positioning plane 63 and the engagement of the annular retaining groove 44 and the retaining projection 61 can be accurately performed without interfering with each other, and the air assist cap 49 Wearability is good.
[0044]
Further, since the air assist cap 49 is made of a synthetic resin, it is possible to easily press-fit the valve seat member 3 and engage the retaining groove 44 and the retaining projection 61 by effectively utilizing its own elasticity. This can contribute to the improvement of the mountability of the air assist cap 49.
[0045]
The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.
[0046]
【The invention's effect】
As described above, according to the first feature of the present invention, the valve seat member having a valve seat and a valve hole penetrating the central portion thereof, the valve body for opening and closing the valve hole in cooperation with the valve seat, , An injector plate having a plurality of fuel injection holes communicating with the valve hole and joined to the outer end surface of the valve seat member; and an injection plate fitted on the outer peripheral surface of the valve seat member and injected from the fuel injection hole A fuel injection valve comprising a guide hollow portion through which fuel passes and an air assist cap made of a synthetic resin having an assist air introduction hole for introducing assist air into the guide hollow portion in order to promote atomization of the injected fuel, An outward positioning plane is formed on the cylindrical outer peripheral surface of the valve seat member, and a circumferential position of the cap with respect to the valve seat member is overlapped on the cylindrical inner peripheral surface of the air assist cap so as to overlap the outward positioning plane. Inward position to determine To form a determined plane, the one and the other mating surface of each other fit of the valve seat member and the air assist cap is interconnected axially the valve seat member and the air-assisted cap engaged with each other A retaining groove and a retaining projection are formed, respectively, and when the air assist cap is fitted to the valve seat member, the outward positioning plane and the inward positioning plane are engaged prior to the engagement of the retaining groove and the retaining protrusion. Since the overlap between the valve seat member and the air assist cap is increased, the valve seat member and the air assist cap have a sufficiently large area to increase the positioning strength of the valve seat member and the air assist cap. Therefore, even when the fuel injection valve is twisted when the fuel injection valve is fitted to the intake manifold, the position of the air assist cap can be reduced. It is possible to prevent misalignment reliably. Further, the valve seat member and the air assist cap can be strongly connected in the axial direction by the engagement of the retaining groove and the retaining protrusion. In addition, when the air assist cap is fitted to the valve seat member, the overlap of the outward positioning plane and the inward positioning plane and the engagement of the annular retaining groove and the retaining projection should be accurately performed without interfering with each other. The air assist cap is easy to wear. Furthermore, since the air assist cap is made of a synthetic resin, the elasticity of the air assist cap itself can be effectively used to easily engage the retaining groove and the retaining protrusion, and the air assist cap can be easily attached. It can contribute to improvement.
[0047]
According to a second aspect of the present invention, in addition to the first feature, each said outward positioning plane and inward positioning plane, in a position facing each diameter line of the valve seat member and the air-assisted cap since a pair is provided, the area of the outward positioning plane and inwardly positioned flat and as wide as possible, Ru can strengthen the positioning strength effectively.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional plan view of an essential part of an internal combustion engine equipped with an electromagnetic fuel injection valve of the present invention.
[Figure 2] sectional view taken along line 2-2 of FIG.
FIG. 3 is an enlarged view of part 3 of FIG.
4 is a view taken in the direction of arrow 4 in FIG. 3;
5 is a cross-sectional view taken along line 5-5 of FIG.
[Explanation of symbols]
I ... Fuel injection valve 3 ... Valve seat member 4 ... Valve body 7 ... Valve hole 8 ... Valve seat 10 ... Injector plate 11a , 11b ... Fuel injection hole 14 ... Valve body 44 ... Retaining groove 46 ... Outward positioning flat surface 49 ... Air assist cap 61 ... Retaining protrusion 63 ... ... Inward positioning plane 67 ...... Guiding hollow part 68 ...... Assist air introduction hole

Claims (2)

弁座（８）及びその中心部を貫通する弁孔（７）を有する弁座部材（３）と，前記弁座（８）と協働して前記弁孔（７）を開閉する弁体（１４）と，前記弁孔（７）に連通する複数の燃料噴孔（１１ａ，１１ｂ）を有して前記弁座部材（３）の外端面に接合されるインジェクタプレート（１０）と，前記弁座部材（３）の外周面に嵌装され，前記燃料噴孔（１１ａ，１１ｂ）からの噴射燃料が通過する誘導中空部（６７）及び，前記噴射燃料の微粒化を促進すべく前記誘導中空部（６７）にアシストエアを導入するアシストエア導入孔（６８）を有する合成樹脂製のエアアシストキャップ（４９）とを備える燃料噴射弁において，
前記弁座部材（３）の円筒状外周面に外向き位置決め平面（４６）を形成する一方，前記エアアシストキャップ（４９）の円筒状内周面に，前記外向き位置決め平面（４６）に重なって該キャップ（４９）の弁座部材（３）に対する周方向位置を決定する内向き位置決め平面（６３）を形成すると共に、
前記弁座部材（３）及びエアアシストキャップ（４９）の互いに嵌合する嵌合面の一方及び他方に，互いに係合して前記弁座部材（３）及びエアアシストキャップ（４９）を相互に軸方向に連結する抜け止め溝（４４）及び抜け止め突起（６１）をそれぞれ形成し，前記エアアシストキャップ（４９）の弁座部材（３）への嵌合時には，これら抜け止め溝（４４）及び抜け止め突起（６１）の係合に先立ち，前記外向き位置決め平面（４６）及び内向き位置決め平面（６３）の重なりが開始するようにしたことを特徴とする，燃料噴射弁におけるエアアシストキャップの位置決め構造。A valve seat member (3) having a valve seat (8) and a valve hole (7) penetrating through the central portion thereof, and a valve body (open and close) in cooperation with the valve seat (8) ( 14), an injector plate (10) having a plurality of fuel injection holes (11a, 11b) communicating with the valve hole (7) and joined to the outer end surface of the valve seat member (3), and the valve A guide hollow portion (67) that is fitted on the outer peripheral surface of the seat member (3) and through which the injected fuel from the fuel injection holes (11a, 11b) passes, and the guide hollow to promote atomization of the injected fuel. A fuel injection valve including a synthetic resin air assist cap (49) having an assist air introduction hole (68) for introducing assist air into the portion (67);
An outward positioning plane (46) is formed on the cylindrical outer peripheral surface of the valve seat member (3), while the outer peripheral positioning plane (46) is overlapped with the cylindrical inner peripheral surface of the air assist cap (49). Forming an inward positioning plane (63) for determining the circumferential position of the cap (49) with respect to the valve seat member (3) ,
The valve seat member (3) and the air assist cap (49) are engaged with each other on one and the other of the fitting surfaces of the valve seat member (3) and the air assist cap (49), and the valve seat member (3) and the air assist cap (49) are mutually connected. A retaining groove (44) and a retaining protrusion (61) that are connected in the axial direction are formed, and when the air assist cap (49) is fitted to the valve seat member (3), these retaining grooves (44) An air assist cap in a fuel injection valve , wherein the outward positioning plane (46) and the inward positioning plane (63) start to overlap prior to the engagement of the retaining protrusion (61). Positioning structure. 請求項１記載の燃料噴射弁におけるエアアシストキャップの位置決め構造において，
前記外向き位置決め平面（４６）及び内向き位置決め平面（６３）を，前記弁座部材（３）及びエアアシストキャップ（４９）の各直径線上で対向する位置にそれぞれ一対設けたことを特徴とする，燃料噴射弁におけるエアアシストキャップの位置決め構造。In the positioning structure of the air assist cap in the fuel injection valve according to claim 1,
A pair of the outward positioning plane (46) and the inward positioning plane (63) are provided at positions facing each other on each diameter line of the valve seat member (3) and the air assist cap (49). , Positioning structure of air assist cap in fuel injection valve.

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