JP3797533B2

JP3797533B2 - Valve operating device for internal combustion engine

Info

Publication number: JP3797533B2
Application number: JP2000036934A
Authority: JP
Inventors: 利祐秋和; 誠幸高橋
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2000-02-15
Filing date: 2000-02-15
Publication date: 2006-07-19
Anticipated expiration: 2020-02-15
Also published as: JP2001227305A

Description

【０００１】
【発明の属する技術分野】
本出願発明は、カム軸に設けられたカムにより直接または間接に揺動される複数のロッカアームを有し、該ロッカアームと連動して開閉作動される機関弁である吸気弁および排気弁を備えた内燃機関の動弁装置に関し、詳細には、複数のロッカアームを機関弁またはカムに向けてそれぞれ弾発力により付勢する複数の付勢部材をそれぞれ保持する複数の保持部が形成されたホルダに関する。
【０００２】
【従来の技術】
従来、内燃機関の機関弁である吸気弁または排気弁のリフト量等の開弁特性を機関運転状態に応じて切り換えることにより、燃費改善や出力向上を図るべく、カム軸に設けられたプロフィルの異なる複数のカムにより揺動される複数のロッカアームに、それらロッカアームを連結状態および連結解除状態に切り換える連結切換機構が設けられた内燃機関の動弁装置が知られている。
【０００３】
例えば、実開平４−１６０６号公報に開示された内燃機関の動弁装置では、シリンダ毎に、カムシャフトに設けられた隆起部および低速用カムにそれぞれ摺接すると共に、一対の吸気弁にそれぞれ連動、連結された一対の駆動ロッカアームと、高速用カムに摺接すると共に、吸気弁に対して自由となり得る１つの自由ロッカアームが設けられ、さらにそれらロッカアームの連結および連結解除を切換可能な連結切換機構が設けられる。高速用カムにより揺動される自由ロッカアームは、機関の低速運転時には、吸気弁とは無関係に空動きするため自由ロッカアームの暴れを防止すべく、自由ロッカアームを高速用カムに向けて弾発付勢するロストモーション機構が設けられる。
【０００４】
このロストモーション機構は、シリンダヘッドに固定される支持板に設けられた有底円筒部に嵌合される。そして、支持板には、有底円筒部と支持板の締結部とを連結するリブが設けられて、支持板全体の剛性が高められるとともに、高速用カムと自由ロッカアームとの摺接に基づいてロストモーション機構に作用する荷重により生じる有底円筒部周辺の支持板の変形も抑制され、その結果、変形によるロストモーション機構の動作の不具合の発生、例えば設定された弾発力よりも弾発力が弱くなったり、弾発力の作用方向が設定方向からずれたり、摺動部分の摺動運動が円滑に行われなくなるのが抑制される。
【０００５】
【発明が解決しようとする課題】
ところで、前記従来技術では、付勢部材としてのロストモーション機構が各シリンダに１個設けられているだけであるため、ロストモーション機構に作用する荷重による複数の有底円筒部の間の支持板の変形は、前記リブによりある程度抑制される。しかしながら、例えば特開平８−６１０３１号公報に開示された多気筒内燃機関の動弁装置のように、各シリンダに複数個のロストモーション機構が設けられ、それらロストモーション機構が支持板の複数の保持部でそれぞれ保持される場合、各保持部に作用する荷重により、複数の保持部の間にある支持板は変形し易くなる。そこで、それら複数の保持部の間の支持板の剛性を高めるために、支持板全体を肉厚を増したり、またはそれら複数の保持部の間にさらにリブを設けたりすることは、内燃機関の重量増を招来するため、燃費の悪化やコスト高につながる。
【０００６】
本出願発明は、このような事情に鑑みてなされたものであって、請求項１ないし請求項３記載の発明は、複数の付勢部材を備えた内燃機関の動弁装置において、付勢部材を保持する複数の保持部が設けられたホルダの重量増を抑制しつつ複数の保持部の間の剛性を高め、さらに、ホルダ全体の剛性を高めることを目的とする。
【０００７】
【課題を解決するための手段および発明の効果】
本出願の請求項１記載の発明は、カム軸に設けられたカムにより直接または間接に揺動されて機関弁と連動し得る複数のロッカアームを、該機関弁または該カムに向けてそれぞれ弾発力により付勢する複数の付勢部材と、シリンダヘッドに取り付けられて該付勢部材をそれぞれ保持する複数の保持部が設けられたホルダとを備えた内燃機関の動弁装置において、少なくとも２つの前記保持部同士が直接連結されて一体化されており、前記ホルダには、前記カム軸の軸方向に沿って延びて前記保持部相互を連結する第１リブと、該第１リブと連結された前記保持部とは別の前記保持部および前記ホルダを前記シリンダヘッドへ取り付けるための該ホルダの締結部を連結する第２リブとが設けられており、該第２リブは、連結している該保持部と該締結部との間で前記第１リブと連結されている内燃機関の動弁装置である。
【０００８】
この請求項１記載の発明によれば、付勢部材をそれぞれ保持する少なくとも２つの保持部は、それら保持部が直接連結されて一体化されているため、保持部が互いに補強し合うので、保持部の間の剛性が高められる結果、保持部の間の変形を抑制できて、付勢部材の不具合の発生を抑制できる。そして、相互の保持部自体の利用により、ホルダに新たな補強構造を追加形成することなく保持部の間の剛性を高めることができるため、ホルダの重量増を抑制できる。また、保持部相互が直接連結されて一体化されているので、複数の保持部をコンパクトに配置することができる。
しかも、ホルダに設けられるリブが、カム軸の軸方向に延びて保持部相互を連結する第１リブと、保持部と締結部との間で第１リブと連結している第２リブとが交差する形態のリブとなるため、ホルダ全体の剛性が高められる結果、付勢部材の不具合の発生が一層抑制され、また動弁装置の作動が安定し、そのうえ振動が抑制されて、騒音が低減する。
【０００９】
請求項２記載の発明は、請求項１記載の内燃機関の動弁装置おいて、直接連結された前記少なくとも２つの保持部は、有底孔を有すると共に前記ホルダのロッカアーム側に開放する開口端を有する有底保持部と、該ホルダを貫通する貫通孔を有すると共に、該ロッカアーム側に開放する第１開口端および該ホルダの反ロッカアーム側に開放する第２開口端を有する貫通保持部とからなり、該貫通保持部は前記ロッカアームを挟んで前記シリンダヘッドとは反対側に配置され、前記有底保持部の前記有底孔には前記付勢部材の一部が保持され、該貫通保持部の該貫通孔には、前記付勢部材のうち、前記第２開口端から該貫通孔に装着可能に形成された付勢部材が保持されているものである。
【００１０】
この請求項２記載の発明によれば、直接連結されて一体化された少なくとも２つの保持部が、有底保持部と貫通保持部との組合せからなる。その結果、一体化された保持部が貫通孔でなく底を有する有底保持部を含むことから、少なくとも２つの保持部の間の剛性を高めることができると同時に、シリンダヘッドへホルダを取り付けた装着後に、貫通孔を利用することにより、ホルダの、ロッカアーム等の動弁機構がない側である反ロッカアーム側に開放する第２開口端から貫通孔に付勢部材を装着できるので、付勢部材の装着が容易となり、付勢部材の組付け作業性を向上させることができる。
【００１１】
請求項３記載の発明は、カム軸に設けられたカムにより直接または間接に揺動されて機関弁と連動し得る複数のロッカアームを、該機関弁または該カムに向けてそれぞれ弾発力により付勢する複数の付勢部材と、シリンダヘッドに取り付けられて該付勢部材をそれぞれ保持する複数の保持部が設けられたホルダとを備えた内燃機関の動弁装置において、少なくとも２つの前記保持部は、該各保持部が前記ホルダを前記シリンダヘッドへ取り付けるための該ホルダの締結部と直接連結され、該締結部を介して一体に連結されており、前記ホルダには、前記カム軸の軸方向に沿って延びて前記保持部相互を連結する第１リブと、該第１リブと連結された前記保持部とは別の前記保持部および前記ホルダを前記シリンダヘッドへ取り付けるための該ホルダの締結部を連結する第２リブとが設けられており、該第２リブは、連結している該保持部と該締結部との間で前記第１リブと連結されている内燃機関の動弁装置である。
【００１２】
この請求項３記載の発明によれば、少なくとも２つの保持部のそれぞれは、ホルダにおいてシリンダヘッドと結合される締結部と直接連結されて一体となっているため、それら保持部の間の剛性が高められる結果、保持部の間の変形を抑制できて、付勢部材の不具合の発生を抑制できる。また、保持部が位置する締結部の近傍は高剛性となっているため、ロッカアームの揺動に基づいて付勢部材を介して作用する荷重によるホルダ全体の変形を抑制できる。
しかも、第１，第２リブにより、請求項１に係る発明と同様に、ホルダ全体の剛性が高められて、付勢部材の不具合の発生が一層抑制され、また動弁装置の作動が安定し、そのうえ振動が抑制されて、騒音が低減する。
【００１５】
【発明の実施の形態】
以下、本出願発明の一実施形態を図１ないし図７を参照して説明する。
この実施形態において、内燃機関は、車両用の６気筒Ｖ型のＳＯＨＣ内燃機関であり、該内燃機関の一方のバンクを形成する気筒は、低負荷運転域等の燃費重視の機関運転域では、それら気筒の吸気弁および排気弁の開閉作動が休止されて気筒休止状態とされる。
【００１６】
図１、図３ないし図５を参照すると、休止気筒側のバンクにおいて、シリンダブロック（図示されず）に結合されて、該シリンダブロックと共に内燃機関の機関本体の一部を構成するシリンダヘッド１には、クランク軸に沿って配列された３つの気筒A1，A2，A3毎に、燃焼室２に開口する一対の吸気ポート３の吸気口を開閉する一対の機関弁である吸気弁5a，5bと、燃焼室２に開口する一対の排気ポート４の排気口を開閉する一対の機関弁である排気弁6a，6bとが設けられる。なお、シリンダヘッド１の上端面にはシリンダヘッドカバーが結合されて、動弁装置が収容される密閉された動弁室が形成される。また、図１には、各気筒に対応する部分を、符号A1，A2，A3で示している。
【００１７】
各気筒A1，A2，A3において、一対の吸気弁5a，5bは、シリンダヘッド１に圧入されたステムガイド７に摺動自在に嵌合され、シリンダヘッド１と弁ステム端部の鍔部９との間に圧縮状態で装着された弁ばね11により、閉弁方向に付勢される。同様に、一対の排気弁6a，6bも、シリンダヘッド１に圧入されたステムガイド８に摺動自在に嵌合され、シリンダヘッド１と弁ステム端部の鍔部10との間に圧縮状態で装着された弁ばね12により、閉弁方向に付勢される。
【００１８】
内燃機関のクランク軸により１／２の減速比で回転駆動されるカム軸13が、シリンダヘッド１に回転自在に支持される。カム軸13には、吸気カム14と、カム軸13に沿って吸気カム14の両側に位置する一対の排気休止カム15a，15bと、さらに両排気休止カム15a，15bに対して吸気カム14がある側とは反対側に一対の排気カム16a，16bが設けられる。吸気カム14は、内燃機関の通常運転時に一対の吸気弁5a，5bを開閉作動するリフト部とベース円部とからなるプロフィルを有し、両排気休止カム15a，15bは、気筒休止運転時に両排気弁6a，6bを閉弁状態とするベース円部のみからなるプロフィルを有し、両排気カム16a，16bは、内燃機関の通常運転時に一対の排気弁6a，6bをそれぞれ開閉作動するリフト部とベース円部とからなるプロフィルを有する。
【００１９】
一対の吸気弁5a，5bとカム軸13との間には、第１，第２吸気ロッカアーム17，18と、両吸気ロッカアーム17，18の間に位置する第３吸気ロッカアーム19とが、カム軸13の上方でシリンダヘッド１に固定された吸気ロッカアーム軸20に並列した状態で揺動自在に支持される。一方、一対の排気弁6a，6bとカム軸13との間には、第１，第２排気ロッカアーム21，22と、両排気ロッカアーム21，22を挟んでそれらの両側に位置する第３，第４排気ロッカアーム23，24とが、カム軸13の上方でシリンダヘッド１に固定された排気ロッカアーム軸25に並列した状態で揺動自在に支持される。
【００２０】
第１，第２吸気ロッカアーム17，18のそれぞれにおいて、その一端部は吸気ロッカアーム軸20に支持され、その他端部には、吸気弁5a，5bの弁ステム端部に当接するタペットねじ26が進退自在に設けられ、その中間部には後述する第１連結切換機構M1が設けられる。また、図３に図示されるように、第３吸気ロッカアーム19の一端部には、吸気カム14に摺接するローラ28が軸支され、その他端には第１連結切換機構M1が設けられ、その中間部は吸気ロッカアーム軸20に支持される。それゆえ、第１，第２吸気ロッカアーム17，18は、両吸気弁5a，5bとそれぞれ連動し、第３吸気ロッカアーム19は、吸気カム14により直接に揺動される。
【００２１】
一方、第１，第２排気ロッカアーム21，22のそれぞれにおいて、その一端部には、排気休止カム15a，15bに摺接すると共に後述する第２連結切換機構M2が内蔵されたローラ29が軸支され、その他端部には、排気弁6a，6bの弁ステム端部に当接するタペットねじ27が進退自在に設けられ、その中間部は、排気ロッカアーム軸25に支持される。ローラ29は、図７に図示されるように、それぞれ、第１，第２排気ロッカアーム21，22に圧入固定される内輪29aと、排気休止カム15a，15bに摺接する外輪29bと、内輪29aおよび外輪29b間に配置された多数のコロ29cとから構成される。また、第３，第４排気ロッカアーム23，24のそれぞれにおいて、その一端部には、排気カム16a，16bに摺接するとともに、第２連結切換機構M2が内蔵されたローラ30が軸支され、その他端は、排気ロッカアーム軸25に支持されている。ローラ30は、第３，第４排気ロッカアーム23，24に圧入固定される内輪30aと、排気カム16a，16bに摺接する外輪30bと、内輪30aおよび外輪30b間に配置された多数のコロ30cとから構成される。それゆえ、第１，第２排気ロッカアーム21，22は、両排気弁6a，6bとそれぞれ連動し、第３，第４排気ロッカアーム23，24は、両排気カム16a，16bによりそれぞれ直接に揺動される。
【００２２】
このように、第１，第２吸気ロッカアーム17，18は、吸気カム14の動きに対して拘束されることなく自由になり得る自由ロッカアームであり、第３吸気ロッカアーム19は、両吸気弁5a，5bを開閉作動させることなく、両吸気弁5a，5bに対して自由になり得る自由ロッカアームである。同様に、第３，第４排気ロッカアーム23，24のそれぞれは、排気弁6a，6bを開閉作動させることなく、排気弁6a，6bに対して自由になり得る自由ロッカアームである。また、第３吸気ロッカアーム19の前記一端部は、カム軸13の上方で、第１排気ロッカアーム21の前記一端部と第２排気ロッカアーム22の前記一端部との間に、カム軸13に沿って並列した状態で隣接して位置する。
【００２３】
シリンダヘッド１において、カム軸13を挟んでシリンダブロックとの結合面とは反対側の端面である上端面には、３つの気筒A1，A2，A3の気筒配列方向、すなわちカム軸13の軸方向Ｌで、シリンダヘッド１の一端部から他端部に渡って、図２に図示される板状のホルダ50が、１０個の締結部材であるボルトB1〜B10（図１参照）により取り付けられる。
【００２４】
このホルダ50には、各気筒A1，A2，A3について、第１，第２吸気ロッカアーム17，18を、それぞれ、タペットねじ26を介して両吸気弁5a，5bの弁ステム端部に向けて弾発力により付勢する付勢部材としての第１，第２ロストモーション機構31，32、第３吸気ロッカアーム19を吸気カム14に向けて弾発力により付勢する付勢部材としての第３ロストモーション機構33、第３，第４排気ロッカアーム23，24を、それぞれ、両排気カム16a，16bに向けて弾発力により付勢する付勢部材としての第４，第５ロストモーション機構34，35が、それぞれ装着されて保持される第１ないし第５保持部51〜55が形成される。さらに、ホルダ50には、各ボルトB1〜B10に対応して、ボルト挿通孔が形成された円筒状のボスからなる締結部C1〜C10が形成される。
【００２５】
図４を参照すると、第１，第２保持部51，52は、有底孔51a，52aを有すると共に、ホルダ50に対して、各ロッカアーム17〜19，21〜24が配置された側であるロッカアーム側50aで開放した開口端51b，52bを有する有底の一部円筒状の筒体形状をした有底保持部であり、ホルダ50において、ロッカアーム側50aとは反対側の反ロッカアーム側50bに突出している。
【００２６】
有底孔51a，52aにそれぞれ装着される第１，第２ロストモーション機構31，32は同一の構造を有し、それぞれ、有底孔51a，52aに摺動自在に嵌合される頂面を有する円筒状のピストン36と、ピストン36の頂面が第１，第２吸気ロッカアーム17，18の上部に形成された当接面17a，18aに当接して、両吸気ロッカアーム17，18をそれぞれ両吸気弁5a，5bに向けてその弾発力により付勢すべく、ピストン36と各保持部51，52の底面との間に装着される弾発部材としての円筒状のコイルばね37と、各保持部51，52の内面の開口端51b，52b寄りの溝に脱着自在に装着された止め輪38とを備える。
【００２７】
また、図３を参照すると、第３保持部53は、ホルダ50のロッカアーム側50aか
ら反ロッカアーム側50bに貫通し、第３吸気ロッカアーム19を指向した貫通孔53aを有すると共に、ロッカアーム側50aに開放した第１開口端53bと反ロッカアーム側50bに開放した第２開口端53cとを有する一部円筒状の筒体形状の貫通保持部であり、ホルダ50の反ロッカアーム側50bに突出している。そして、図３に示されるように、第３保持部 53 は第３吸気ロッカアーム 19 を挟んでシリンダヘッド１とは反対側に配置される。
【００２８】
貫通孔53aに対して、ホルダ50の反ロッカアーム側50bから装着される第３ロストモーション機構33は、第１開口端53b寄りに位置して、第３吸気ロッカアーム19の上部に形成された当接面19aに当接する当接片41と、第３保持部53の内側の第２開口端53c寄りに形成されたねじ部53dに螺合する固定片42と、当接片41を介して、第３吸気ロッカアーム19を吸気カム14に向けてその弾発力により付勢すべく固定片42と当接片41との間に保持された弾発部材としての円筒状のコイルばね43とを備える。このコイルばね43の外周は第３保持部の内周面に接していて、コイルばね43を貫通孔53aに沿うようにガイドすることにより、その倒れを防止している。
【００２９】
当接片41は、コイルばね43の一端部と当接する鍔状のリテーナ部41aと、コイルばね43の内周に嵌合保持される円柱状の嵌合部41bとからなる。また、固定片42は、コイルばね43の他端部と当接すると共に、外周面にねじ部42dが形成されたリテーナ部42aと、コイルばね43の内周に嵌合保持される円柱状の嵌合部42bと、第２開口端53cに当接するフランジ部42cとからなる。さらに、固定片42には、第３ロストモーション機構33を第３保持部53に装着するために、固定片42のねじ部42dと第３保持部53のねじ部53dとを螺合させて、固定片42をねじ込むための工具が挿入される工具挿入孔である六角孔42eが形成され、さらに六角孔42eの底部に嵌合部42eを貫通する給油孔42fが形成される。給油孔42fは、その上端部が、動弁室の上方空間に向かって開放しており、その下端部が、嵌合部42bの当接片41側の端面に開放している。それゆえ、空間内において、動弁装置の摺動部等に供給される潤滑油の飛沫が、給油孔42fから直接、または固定片42に付着して液流となって給油孔42fを経て、第３ロストモーション機構33の当接片41およびコイルばね43に供給され、それらの摺動部の潤滑が行われる。
【００３０】
一方、図５に図示されるように、第３ロストモーション機構33と同様の構造を有する第４，第５ロストモーション機構34，35が保持される第４，第５保持部54，55は、第３保持部53と同様の構造を有する。それゆえ、図５に示されるように、第４，第５保持部 54 ， 55 は、それぞれ第３，第４排気ロッカアーム 23 ， 24 を挟んでシリンダヘッド１とは反対側に配置される。そして、第４，第５ロストモーション機構34，35の当接片41は、第３，第４排気ロッカアーム23，24の上部に形成された当接面23a，24a（図１参照）にそれぞれ当接している。そして、これら第１〜第５保持部51〜55は、シリンダブロックとシリンダヘッド１との結合面に対して傾斜、すなわち第１〜第５保持部51 〜 55の円筒の中心線が傾斜するように、ホルダ50に設けられる。
【００３１】
ところで、第１，第２，第３吸気ロッカアーム17，18，19に設けられた第１連結切換機構M1は、図６に図示されるように、ピストン60と、第１，第３吸気ロッカアーム17，19を連結し得る連結ピン61と、ピストン60および連結ピン61の移動を規制すると共に第２，第３吸気ロッカアーム18，19を連結し得る連結ピストン62と、ピストン60および連結ピン61を連結側に付勢する戻しばね63とを備える。
【００３２】
第１吸気ロッカアーム17には、ピストン60および連結ピン61が摺動自在に嵌合する有底のガイド孔64が、その開口端を第３吸気ロッカアーム19側にして形成され、ピストン60とガイド孔64の底部との間に油圧室67が形成される。さらに、油圧室67は、連通路68を介して、吸気ロッカアーム軸20の内部の油圧供給路69（図４参照）と第１吸気ロッカアーム17の揺動状態にかかわらず常時連通する。第３吸気ロッカアーム19には、ガイド孔64に対応する位置に同一径のガイド孔65が、その両開口端をそれぞれ第１，第２吸気ロッカアーム17，18側にして形成され、このガイド孔65に連結ピン61および連結ピストン62が摺動自在に嵌合する。第２吸気ロッカアーム18には、ガイド孔65に対応する位置に同一径の有底のガイド孔66が、その開口端を第３吸気ロッカアーム19側にして形成され、このガイド孔66に連結ピストン62が摺動自在に嵌合する。戻しばね63は、連結ピストン62の内周に、ガイド孔66の底部と連結ピストン62との間に圧縮状態で装着される。
【００３３】
そして、油圧制御弁により制御される油圧供給路69の油圧により、第１連結切換機構M1の油圧室67の油圧が低圧とされると、ピストン60、連結ピン61および連結ピストン62は、戻しばね63の弾発力で連結側に移動して、連結ピン61が両ガイド孔64，65に跨って嵌合すると共に、連結ピストン62が両ガイド孔65，66に跨って嵌合して、第１，第２，第３吸気ロッカアーム17，18，19は一体に連結される連結状態となる。また、前記油圧制御弁により油圧室67の油圧が高圧にされると、ピストン60は連結ピン61を第３吸気ロッカアーム19に押し込む位置まで移動して、ピストン60と連結ピン61との当接面が第１，第３吸気ロッカアーム17，19の間に位置し、連結ピン61と連結ピストン62との当接面が第２，第３吸気ロッカアーム18，19の間に位置するため、第１，第２，第３吸気ロッカアーム17，18，19は連結されていない連結解除状態となる。
【００３４】
一方、第１，第３排気ロッカアーム21，23に設けられた第２連結切換機構M2は、図７に図示されるように、ピストン70と、第１，第３排気ロッカアーム21，23を連結し得る連結ピン71と、ピストン70および連結ピン71の移動を規制する規制ピストン72と、ピストン70、連結ピン71および規制ピストン72を連結側に付勢する戻しばね73とを備える。第１排気ロッカアーム21には、ローラ29の内輪29aが圧入固定される有底装着孔21aが、その開口端を第３排気ロッカアーム23側にして形成され、内輪29aに形成されたガイド孔74に、ピストン70と連結ピン71とが摺動自在に嵌合する。そして、ピストン70と有底装着孔21aの底部との間に形成された油圧室76は、連通路77を介して、排気ロッカアーム軸25内部の油圧供給路78（図４参照）と第１排気ロッカアーム21の揺動状態にかかわらず常時連通する。また、第３排気ロッカアーム23には、ローラ30の内輪30aが圧入固定される有底装着孔23bが、その開口端を第１排気ロッカアーム21側にして形成され、内輪30aにおいて、ガイド孔74に対応する位置に形成された同一径のガイド孔75に、連結ピン71と規制ピストン72とが摺動自在に嵌合する。戻しばね73は、規制ピストン72の内側で、有底装着孔23bの底部と規制ピストン72との間に圧縮状態で装着される。
【００３５】
そして、油圧制御弁により制御される油圧供給路78の油圧により、第２連結切換機構M2の油圧室76の油圧が低圧にされると、ピストン70、連結ピン71および規制ピストン72は、戻しばね73の弾発力で連結側に移動して、連結ピン71がガイド孔74，75に跨って嵌合して第１，第３排気ロッカアーム21，23は一体に連結される連結状態となる。また、前記油圧制御弁により油圧室76の油圧が高圧にされると、ピストン70は連結ピン71を第３排気ロッカアーム23に押し込む位置まで移動して、ピストン70と連結ピン71との当接面が第１，第３排気ロッカアーム21，23の間に位置するため、第１，第３排気ロッカアーム21，23は連結されていない連結解除状態となる。
【００３６】
また、第２，第４排気ロッカアーム22，24にも、第１，第３排気ロッカアーム21，23に設けられた第２連結切換機構M2と同様の構造を有する第２連結切換機構M2が設けられ、その油圧室76の油圧が低圧のとき、ピストン70、連結ピン71および規制ピストン72は、戻しばね73の弾発力で連結側に移動しており、連結ピン71がガイド孔74，75に跨って嵌合して第２，第４排気ロッカアーム22，24は一体に連結される連結状態となる。油圧室76の油圧が高圧になると、ピストン70は連結ピン71を第４排気ロッカアーム24に押し込む位置まで移動して、ピストン70と連結ピン71との当接面が第２，第４排気ロッカアーム22，24の間に位置するため、第２，第４排気ロッカアーム22，24は連結されていない連結解除状態となる。
【００３７】
ここで、前述した、カムが設けられたカム軸13、各ロッカアーム17〜19，21〜24、各ロッカアーム軸20，25、吸気弁5a，5b、排気弁6a，6b、ホルダ50およびそれらに付属する部材により、動弁装置が構成されている。
【００３８】
次に、図１および図２を参照しつつ、反ロッカアーム側50bに突出している保持部51，52，53，54，55、締結部C1〜C10および補強用のリブが、鋳造により一体成形されているホルダ50についてさらに説明する。
気筒A1において、第３保持部53のカム軸13の軸方向Ｌにおける両側面に第１，第２保持部51，52の側面が直接連結されている。
【００３９】
カム軸13の軸線に対して第３保持部53の第２開口端53cがある側とは反対側に位置して、第３保持部53の円筒の中心線を通りカム軸13の軸線と直交する平面Ｐに対して略対称に第２開口端54c，55cが位置するように第４，第５保持部54，55が配置され、両保持部54，55の間で、肉抜きにより形成された凹部56に、第１，第２排気ロッカアーム21，22の上部が入り込むようにされる。残りの２気筒A2，A3についても、ホルダ50における第１ないし第５保持部51，52，53，54，55の配置は同様である。さらに、第１，第２排気ロッカアーム21，22の間であってタペットねじ27，27が設けられた端部寄りには、点火栓が挿入されるパイプ39が配置されている。
【００４０】
また、ホルダ50をシリンダヘッド１に締結するボルトB1〜B10が挿通されて締結される締結部C1〜C10は、以下のように配置される。
一列に配列された３つの気筒A1，A2，A3のうち、一端部に位置する気筒A1については、気筒A1の保持部51，52，53，54，55のうち最もホルダ50の一端部寄りに位置する第４保持部54の、カム軸13の軸方向Ｌでホルダ50の一端部寄りの側方において、締結部C1が、その側面と第４保持部54の側面とが直接連結される位置に設けられる。
【００４１】
また、第１，第２保持部51，52において、カム軸13の軸方向Ｌで、第３保持部53が位置する側とは反対側の側方には、２つの締結部C2，C3がそれぞれ設けられ、第３保持部53の側面と両締結部C2，C3の側面との間が第４リブ84，84でそれぞれ連結される。
【００４２】
さらに、気筒A1の保持部51〜55のうち最も気筒A2寄りに位置する第５保持部55の、カム軸13の軸方向Ｌで気筒A2寄りの側方において、締結部C4が、その側面と第５保持部55の側面とが直接連結される位置に設けられる。さらに、この締結部C4において、カム軸13の軸方向Ｌで第５保持部55が位置する側とは反対側の側面が、気筒A2の保持部51〜55において最も気筒A1寄りに位置する第４保持部54の側面と直接連結される。
【００４３】
気筒A2および気筒A3についても、気筒A1と同様の保持部51〜55および締結部C4〜C7の配置とされる。すなわち、気筒A2において、締結部C4は、第４保持部54のカム軸13の軸方向Ｌで気筒A1寄りの側方で、前述のように第４保持部54の側面と直接連結される位置に設けられる。また、第１，第２保持部51，52において、カム軸13の軸方向Ｌでその側方に設けられた２つの締結部C5，C6の側面が、第１，第２保持部51，52の側面との間に設けられた第４リブ84でそれぞれ連結される。さらに、側面が気筒A3における第４保持部54の側面と直接連結されている締結部C7は、カム軸13の軸方向Ｌで気筒A3における第４保持部54が位置する側とは反対側の側面が、気筒A2の保持部51〜55のうち最も気筒A3寄りに位置する第５保持部55の側面と直接連結される位置に設けられる。
【００４４】
同様に、気筒A3おいて、締結部C7は、第４保持部54のカム軸13の軸方向Ｌで気筒A2寄りの側方で、第４保持部54の側面と直接連結される位置に設けられる。また、第１，第２保持部51，52において、カム軸13の軸方向Ｌでその側方に設けられた２つの締結部C8，C9の側面が、第１，第２保持部51，52の側面との間に設けられた第４リブ84，84で連結される。さらに、締結部C10は、その側面が、気筒A3の保持部51〜55のうち最もホルダ50の他端部寄りに位置する第５保持部55の、カム軸13の軸方向Ｌでホルダ50の他端部寄りの側方で、第５保持部55の側面と直接連結される位置に設けられる。
【００４５】
そして、これら締結部C1〜C10のうち、カム軸13に対して、相互に直接連結されている第１，第２，第３保持部51，52，53が位置する側の隣接する気筒A1，A2間の締結部C3，C5の間および気筒A2，A3間の締結部C6，C8の間、そして両端の気筒A1，A3の端部に位置する締結部C2，C9のホルダ50の端部寄りには、肉抜きにより凹部57が形成されて、凹部57の位置に対応するシリンダヘッド１には、シリンダヘッド１をシリンダブロックに結合するための結合部材、例えばボルトが挿通される挿通孔58が形成される。そして、隣接する気筒間の締結部C3，C5，C6，C8には、その対向する側の部分に、該結合部材とそれら締結部C3，C5，C6，C8とが干渉しないように切欠部59が設けられ、さらに両端部寄りに位置する締結部C2，C9には、その端部寄りの部分に同様の切欠部59が設けられる。
【００４６】
また、第１，第２ロストモーション機構31，32においては、両吸気弁5a，5bの閉弁時、また第３，第４，第５ロストモーション機構33〜35においては、吸気カム14または排気カム16a，16bにより第３吸気ロッカアーム19または第３，第４排気ロッカアーム23，24が揺動するとき、コイルばね37またはコイルばね43の圧縮によるばね力が保持部51〜55に作用する。そこで、ホルダ50には、その作用する荷重に対抗すべく、また動弁系の動作による振動発生を抑制すべく、その剛性を高めるための複数のリブが設けられている。こられリブのうち、第１リブ81は、各気筒A1,A2,A3の第３保持部53の中心線方向長さの略中央位置において、カム軸13の軸方向Ｌの側面に連結されて、カム軸13の軸方向Ｌに沿って直線状に延びている。
【００４７】
さらに、第２リブ82は、各気筒A1,A2,A3において、第４保持部54，54，54の中心線および締結部C2，C5，C8の中心線を含む面に沿って両者の側面を連結するように直線状に延びるリブ82aと、第５保持部55，55，55の中心線および締結部C3，C6，C9の中心線を含む面に沿って両者の側面を連結するように直線状に延びるリブ82bとから構成されている。この第２リブ82は、連結している第４，第５保持部54，55と締結部C2，C5，C8， C3，C6，C9との間で第１リブ81と交差するように、この実施形態では略直交するように延びていて、その交差部で第１リブ81と連結されている。
【００４８】
第３リブ83は、気筒A1においては、第３保持部53の第１リブ81との連結部Ｄと、第４保持部54の側面と直接連結された締結部C1の側面および第５保持部55の側面と直接連結された締結部C4の側面とを連結すべく、直線状に延びている。さらに、第３リブ83は、気筒A2，A3においても気筒A1と同様であり、気筒A2については、第３保持部53の第１リブ81との連結部Ｄと、締結部C4の側面および締結部C7の側面とを連結すべく直線状に延びており、気筒A3については、第３保持部53の第１リブ81との連結部Ｄと、締結部C7の側面および締結部C10の側面とを連結すべく直線状に延びている。そして、これら第３リブ83は、第２リブ82と第４，第５保持部54，55の近傍で交差しており、その交差部で第２リブ82と連結されている。
【００４９】
このように構成された動弁装置において、内燃機関が運転されると、気筒休止運転をしない通常運転時は、第１連結切換機構M1の油圧室67が低圧とされるため、第１，第２，第３吸気ロッカアーム17，18，19は連結状態にあり、第３吸気ロッカアーム19が摺接する吸気カム14により、一対の吸気弁5a，5bに当接する第１，第２吸気ロッカアーム17，18が第３吸気ロッカアーム19と一体に揺動するため、両吸気弁5a，5bは吸気カム14により定まる開弁特性により開閉作動される。それゆえ、第１，第２吸気ロッカアーム17，18は、両吸気カム14によりそれぞれ間接に揺動され、第３吸気ロッカアーム19は、吸気弁5a，5bと連動する。
【００５０】
一方、このとき、両第２連結切換機構M2，M2の油圧室76が低圧とされるため、第１，第３排気ロッカアーム21，23、および第２，第４排気ロッカアーム22，24は、それぞれ連結状態にあり、第３，第４排気ロッカアーム23，24がそれぞれ摺接する排気カム16a，16bにより、排気弁6aと当接する第１排気ロッカアーム21が第３排気ロッカアーム23と、また排気弁6bと当接する第２排気ロッカアーム22が第４排気ロッカアーム24と、それぞれ一体に揺動するため、両排気弁6a，6bは、それぞれ排気カム16a，16bにより定まる開弁特性で開閉作動される。それゆえ、第１，第２排気ロッカアーム21，22は、両排気カム16a，16bによりそれぞれ間接に揺動され、第３，第４排気ロッカアーム23，24は、両排気弁6a，6bとそれぞれ連動する。
【００５１】
内燃機関が低負荷運転域等の燃費重視の機関運転域で運転される気筒休止運転時は、第１連結切換機構M1の油圧室67が高圧とされるため、第１，第２，第３吸気ロッカアーム17，18，19は連結解除状態にあって、一対の吸気弁5a，5bには、第３吸気ロッカアーム19を介して吸気カム14の開弁力が伝達されないため、両吸気弁5a，5bは常時閉弁状態となる。
【００５２】
そして、第１，第２吸気ロッカアーム17，18は、第１，第２ロストモーション機構31，32のコイルばね37の弾発力により、気筒休止運転時においても適正なバルブクリアランスを常時維持している。また、第３吸気ロッカアーム19は、第３ロストモーション機構33のコイルばね43の弾発力により吸気カム14に摺接するように付勢された状態で、空動きするが、第３ロストモーション機構33のコイルばね43が伸縮することで、第３吸気ロッカアーム19の暴れが防止される。
【００５３】
また、両第２連結切換機構M2，M2の油圧室76が高圧とされるため、第１，第３排気ロッカアーム21，23、および第２，第４排気ロッカアーム22，24は、それぞれ連結解除状態にあり、第３，第４排気ロッカアーム23，24は、それぞれ摺接する休止排気カム16a，16bにより常時閉弁状態となる。そして、第３，第４排気ロッカアーム23，24は、それぞれ第４，第５ロストモーション機構34，35のコイルばね43の弾発力により排気カム16a，16bに摺接するように付勢された状態で、空動きするが、第４，第５ロストモーション機構34，35のコイルばね43が伸縮することで、第３，第４排気ロッカアーム23，24の暴れが防止される。
【００５４】
以下、前述のように構成された実施形態の作用および効果について説明する。第１，第２，第３ロストモーション機構31，32，33をそれぞれ保持する第１，第２，第３保持部51，52，53が直接連結されて一体化されているため、それら保持部51〜53が互いに補強し合うので、それら保持部51〜53の間の剛性が高められる結果、保持部51〜53の間の変形を抑制できて、各ロストモーション機構31〜33の不具合の発生、例えばコイルばね37，43の設定された弾発力よりも弾発力が弱くなったり、弾発力の作用方向が設定方向からずれたり、ピストン36と第１，第２保持部51，52の内周面との摺動部分やコイルばね43と第３保持部53の内周面との摺動部分などの摺動運動が円滑に行われなくなったりするのが抑制される。
【００５５】
そして、相互の保持部51〜53自体の利用により、ホルダ50に新たな補強構造を追加形成することなく保持部51〜53の間の剛性を高めることができるため、ホルダ50の重量増を抑制できる。また、保持部51〜53相互がカム軸13の軸方向Ｌに並列した状態で直接連結されて一体化されているので、並列した保持部51〜53のカム軸13の軸方向Ｌの幅を小さくでき、３つの保持部51〜53をコンパクトに配置することができて、気筒配列方向の内燃機関の寸法を小さくすることができる。
【００５６】
また、直接連結されて一体化された第１，第２，第３保持部51，52，53は、有底保持部である第１，第２保持部51，52と貫通保持部である第３保持部53の組合せからなる。その結果、一体化されたそれら保持部51，52，53が、貫通孔でなく有底の第１，第２保持部51，52を含むことから、第１，第２，第３保持部51，52，53の間の剛性を高めることができると同時に、シリンダヘッド１にホルダ50を取り付けた後に、貫通孔53aを利用することにより、ホルダ50の、ロッカアーム17〜19、21〜24等の動弁機構がない側である反ロッカアーム側50bに開放する第２開口端53cからに第３ロストモーション機構33を第３保持部53に装着ができるので、ロストモーション機構の装着が容易となり、ロストモーション機構の組付け作業性を向上させることができる。
【００５７】
保持部同士が直接連結された第１，第２，第３保持部51，52，53は、第１，第２リブ81，82および締結部C1〜C10に連結した第３，第４リブ83，84と連結され、第４，第５保持部54，55は、締結部C1，C4，C7，C10に挿通されるボルトB1，B4，B7，B10および締結部C2，C3，C5，C6，C8，C9に連結された第２，第３リブ82,83と連結されているので、ホルダ50全体の剛性が高められ、動弁装置の作動が安定し、そのうえ振動が抑制されて、騒音が低減する。
【００５８】
第４，第５保持部54，55のそれぞれは、ホルダ50においてシリンダヘッド１と結合される締結部C1，C4，C7，C10と直接連結されて一体となっているため、それら保持部54，55の間の剛性が高められる結果、保持部54，55の間の変形を抑制できて、第４，第５ロストモーション機構34，35の不具合の発生を抑制できる。また、保持部54，55が位置する締結部C1，C4，C7，C10の近傍は高剛性となっているため、第３，第４排気ロッカアーム23，24の揺動に基づいて第４，第５ロストモーション機構34，35を介して作用する荷重によるホルダ50全体の変形を抑制できる。
【００５９】
ホルダ50には、カム軸13の軸方向Ｌに沿って延びて各気筒A1，A2，A3の第３保持部53相互を連結する第１リブ81と、第４，第５保持部54，55と締結部C2，C3，C5，C6，C8，C9とをそれぞれ連結する第２リブ82とが設けられており、第２リブ82は、第４保持部54と締結部C2，C5，C8との間、および第５保持部55と締結部C3，C6，C9との間で第１リブ81と連結されている。その結果、第１リブ81と第２リブ82とが交差する形態のリブとなるため、ホルダ50全体の剛性が高められるので、各ロストモーション機構31〜35の不具合の発生が一層抑制され、また動弁装置の作動が安定し、そのうえ振動が抑制されて、騒音が低減する。さらに、実施形態のように、第１リブ81と第２リブ82とが略直交して交差するときは、剛性が一層高められる。
【００６０】
ホルダ50には、第４，第５保持部54，55の間に凹部56が形成され、さらに締結部C3，C5間、締結部C6，C8間および両端部に位置する締結部C2，C9の端部寄りには凹部57が形成されているため、ホルダ50の軽量化、ひいては内燃機関の軽量化ができる。
【００６１】
また、第１〜第５保持部51〜55は、シリンダブロックとシリンダヘッド１との結合面に対して傾斜するようにホルダ50に設けられること、そして第４，第５保持部54，55の間の凹部56に、第１，第２排気ロッカアーム21，22の上部が入り込むようにされていることにより、内燃機関の気筒の軸線方向の寸法を小さくして、内燃機関をコンパクトにすることができる。
【００６２】
以下、前述した実施形態の一部の構成を変更した実施形態について、変更した構成に関して説明する。
前記実施形態では、第１，第２，第３保持部51，52，53の３つの保持部が相互に直接連結されたが、相互に直接連結される保持部は、２つ以上であればよい。前記実施形態では、動弁装置は気筒休止を行う動弁装置ものであったが、気筒休止を行うことなく、機関運転中は常時吸気弁および排気弁の開閉作動を行い、機関運転状態に応じてリフト量等の弁作動特性を変更する機構を備えた動弁装置であってもよい。
【図面の簡単な説明】
【図１】本出願発明が適用される内燃機関の一方のバンクを形成する３気筒のシリンダヘッドの要部平面図である。
【図２】ホルダの平面図である。
【図３】図１のＩＩＩ−ＩＩＩ線断面図である。
【図４】図１のＩＶ−ＩＶ線断面図である。
【図５】図１のＶ−Ｖ線断面図である。
【図６】図４のＶＩ−ＶＩ線断面図である。
【図７】図４のＶＩＩ−ＶＩＩ線断面図である。
【符号の説明】
１…シリンダヘッド、２…燃焼室、３…吸気ポート、４…排気ポート、5a，5b…吸気弁、6a，6b…排気弁、７，８…ステムガイド、９，10…鍔部、11，12…弁ばね、13…カム軸、14…吸気カム、15a，15b …排気休止カム、16a，16b…排気カム、17，18，19…吸気ロッカアーム、20…吸気ロッカアーム軸、21，22，23，24…排気ロッカアーム、25…排気ロッカアーム軸、26，27…タペットねじ、28…ローラ、29，30…ローラ、31〜35…ロストモーション機構、36…ピストン、37…コイルばね、38…止め輪、39…パイプ、
41…当接片、42…固定片、43…コイルばね、
50…ホルダ、51〜55…保持部、51a，52a…有底孔、53a…貫通孔、53c…第２開口端、56，57…凹部、58…挿通孔、59…切欠部、
60…ピストン、61…連結ピン、62…連結ピストン、63…戻しばね、64，65，66…ガイド孔、67…油圧室、68…連通路、69…油圧供給路、70…ピストン、71…連結ピン、72…規制ピストン、73…戻しばね、74，75…ガイド孔、76…油圧室、77…連通路、78…油圧供給路、
81…第１リブ、82…第２リブ、84…第３リブ、84…第４リブ、
A1，A2，A3…気筒、B1〜B10…ボルト、C1〜C10…締結部、Ｄ…連結部、Ｌ…カム軸の軸方向、M1，M2…連結切換機構、Ｐ…平面。[0001]
BACKGROUND OF THE INVENTION
The present invention includes a plurality of rocker arms that are directly or indirectly rocked by a cam provided on a camshaft, and includes an intake valve and an exhaust valve that are engine valves that are opened and closed in conjunction with the rocker arms. More specifically, the present invention relates to a holder formed with a plurality of holding portions that respectively hold a plurality of urging members that urge a plurality of rocker arms toward an engine valve or a cam by an elastic force. .
[0002]
[Prior art]
Conventionally, by switching the valve opening characteristics such as the lift amount of an intake valve or exhaust valve, which is an engine valve of an internal combustion engine, according to the engine operating state, the profile of the camshaft provided for the camshaft is improved. 2. Description of the Related Art A valve operating apparatus for an internal combustion engine is known in which a plurality of rocker arms that are swung by a plurality of different cams are provided with a connection switching mechanism that switches the rocker arms between a connected state and a disconnected state.
[0003]
For example, in the valve operating device for an internal combustion engine disclosed in Japanese Utility Model Laid-Open No. 4-1606, each cylinder is slidably contacted with a raised portion and a low-speed cam provided on the camshaft, and is interlocked with a pair of intake valves. And a pair of drive rocker arms connected to each other and a free rocker arm that is slidably in contact with the high-speed cam and can be free from the intake valve, and a connection switching mechanism that can switch connection and release of the rocker arms. Provided. The free rocker arm that is swung by the high-speed cam moves idle regardless of the intake valve during low-speed operation of the engine, so that the free rocker arm is urged toward the high-speed cam to prevent the free rocker arm from rampaging. A lost motion mechanism is provided.
[0004]
The lost motion mechanism is fitted into a bottomed cylindrical portion provided on a support plate fixed to the cylinder head. The support plate is provided with a rib for connecting the bottomed cylindrical portion and the fastening portion of the support plate, thereby enhancing the rigidity of the entire support plate and based on the sliding contact between the high-speed cam and the free rocker arm. The deformation of the support plate around the bottomed cylindrical part caused by the load acting on the lost motion mechanism is also suppressed, and as a result, the malfunction of the lost motion mechanism due to the deformation occurs, for example, the elasticity more than the set elasticity Are suppressed, the direction of action of the elastic force is deviated from the set direction, and the sliding movement of the sliding portion is prevented from being smoothly performed.
[0005]
[Problems to be solved by the invention]
By the way, in the said prior art, since only one lost motion mechanism as an urging member is provided in each cylinder, a support plate between a plurality of bottomed cylindrical portions due to a load acting on the lost motion mechanism is provided. Deformation is suppressed to some extent by the ribs. However, for example, a plurality of lost motion mechanisms are provided in each cylinder, as in the valve operating device of a multi-cylinder internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 8-61031, and these lost motion mechanisms hold a plurality of support plates. When each of the holding portions holds the support plate, the support plate between the plurality of holding portions is easily deformed by a load acting on each holding portion. Therefore, in order to increase the rigidity of the support plate between the plurality of holding parts, increasing the thickness of the entire support plate or providing further ribs between the plurality of holding parts This leads to an increase in weight, leading to poor fuel consumption and high costs.
[0006]
  The invention of the present application has been made in view of such circumstances, and claims 1 to3In the valve operating apparatus for an internal combustion engine provided with a plurality of urging members, the invention described is provided between the plurality of holding portions while suppressing an increase in the weight of the holder provided with the plurality of holding portions for holding the urging members. Increase rigidityTheFurthermore, it aims at improving the rigidity of the whole holder.
[0007]
[Means for Solving the Problems and Effects of the Invention]
  The invention according to claim 1 of the present application is characterized in that a plurality of rocker arms that can be directly or indirectly swung by a cam provided on a cam shaft and interlocked with an engine valve are elastically directed toward the engine valve or the cam. A plurality of biasing members biased by force;cylinder headAnd a holder provided with a plurality of holding portions each holding the urging member, and at least two of the holding portionsIs straightConnected and integratedAnd the holder includes a first rib extending along the axial direction of the camshaft to connect the holding parts to each other, the holding part separate from the holding part connected to the first rib, and the holder A second rib for connecting a fastening portion of the holder for attaching the holder to the cylinder head is provided, and the second rib is disposed between the holding portion and the fastening portion connected to each other. Connected with one ribThis is a valve operating device for an internal combustion engine.
[0008]
  According to the first aspect of the present invention, the at least two holding portions that respectively hold the urging members are integrated by directly connecting the holding portions, so that the holding portions reinforce each other. As a result of the increased rigidity between the portions, deformation between the holding portions can be suppressed, and the occurrence of a failure of the biasing member can be suppressed. And since the rigidity between holding | maintenance parts can be improved by utilizing mutual holding | maintenance part itself, without newly forming a new reinforcement structure in a holder, the weight increase of a holder can be suppressed. Further, since the holding parts are directly connected and integrated, a plurality of holding parts can be arranged in a compact manner.
  In addition, the rib provided on the holder extends in the axial direction of the camshaft and connects the holding portions to each other, and the second rib connected to the first rib between the holding portion and the fastening portion. The crossed ribs increase the overall rigidity of the holder. As a result, the failure of the urging member is further suppressed, the operation of the valve operating device is stabilized, and vibration is suppressed, reducing noise. To do.
[0009]
  According to a second aspect of the present invention, in the valve operating device for an internal combustion engine according to the first aspect, the at least two holding portions directly connected have a bottomed hole and open to the rocker arm side of the holder. And a through-holding portion having a first opening end opened to the rocker arm side and a second opening end opened to the anti-rocker arm side of the holder. BecomeThe penetrating holding portion is disposed on the opposite side of the cylinder head across the rocker arm,A part of the urging member is held in the bottomed hole of the bottomed holding part, and the through hole of the through-holding part is connected to the through hole from the second opening end of the urging member. An urging member formed so as to be attachable is held.
[0010]
  According to the second aspect of the present invention, the at least two holding portions that are directly connected and integrated include a combination of the bottomed holding portion and the through-holding portion. As a result, since the integrated holding part includes a bottomed holding part having a bottom instead of a through-hole, the rigidity between at least two holding parts can be enhanced,cylinder headBy using the through-hole after attaching the holder to the holder, the biasing member can be attached to the through-hole from the second opening end that opens to the side opposite to the rocker arm, which is the side without the valve mechanism such as the rocker arm. Therefore, it becomes easy to mount the urging member, and the workability of assembling the urging member can be improved.
[0011]
  According to a third aspect of the present invention, a plurality of rocker arms that can be directly or indirectly swung by a cam provided on a cam shaft and interlocked with an engine valve are attached to the engine valve or the cam by elastic force. A plurality of biasing members to be biased;cylinder headAnd a holder provided with a plurality of holding portions each holding the urging member. At least two of the holding portions are arranged such that each holding portion holds the holder.cylinder headIt is directly connected with the fastening part of the holder for mounting to, and is connected integrally through the fastening partAnd the holder includes a first rib extending along the axial direction of the camshaft to connect the holding parts to each other, the holding part separate from the holding part connected to the first rib, and the holder A second rib for connecting a fastening portion of the holder for attaching the holder to the cylinder head is provided, and the second rib is disposed between the holding portion and the fastening portion connected to each other. Connected with one ribThis is a valve operating device for an internal combustion engine.
[0012]
  According to the third aspect of the present invention, each of the at least two holding portions is directly connected to and integrated with the fastening portion coupled to the cylinder head in the holder, so that the rigidity between the holding portions is high. As a result, the deformation between the holding portions can be suppressed, and the occurrence of the failure of the urging member can be suppressed. Further, since the vicinity of the fastening portion where the holding portion is located is highly rigid, deformation of the entire holder due to a load acting via the biasing member based on the rocking of the rocker arm can be suppressed.
  In addition, the first and second ribs increase the rigidity of the entire holder as in the first aspect of the invention, thereby further suppressing the occurrence of the failure of the urging member and stabilizing the operation of the valve gear. Moreover, vibration is suppressed and noise is reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In this embodiment, the internal combustion engine is a 6-cylinder V-type SOHC internal combustion engine for vehicles, and the cylinders forming one bank of the internal combustion engine are in an engine operating range where fuel consumption is important, such as a low-load operating range, The opening / closing operations of the intake valve and the exhaust valve of these cylinders are suspended, and the cylinders are deactivated.
[0016]
Referring to FIGS. 1 and 3 to 5, a cylinder head 1 which is coupled to a cylinder block (not shown) in a bank on the idle cylinder side and forms a part of an engine main body of the internal combustion engine together with the cylinder block. Is a pair of intake valves 5a, 5b which are a pair of engine valves for opening and closing the intake ports of the pair of intake ports 3 opened to the combustion chamber 2 for each of the three cylinders A1, A2, A3 arranged along the crankshaft. Exhaust valves 6a and 6b, which are a pair of engine valves for opening and closing the exhaust ports of the pair of exhaust ports 4 that open to the combustion chamber 2, are provided. A cylinder head cover is coupled to the upper end surface of the cylinder head 1 to form a sealed valve operating chamber in which the valve operating device is accommodated. Further, in FIG. 1, portions corresponding to the respective cylinders are indicated by reference signs A1, A2, and A3.
[0017]
In each cylinder A1, A2, A3, a pair of intake valves 5a, 5b is slidably fitted to a stem guide 7 press-fitted into the cylinder head 1, and a cylinder head 1 and a flange 9 at the end of the valve stem. In the meantime, the valve spring 11 mounted in a compressed state is urged in the valve closing direction. Similarly, the pair of exhaust valves 6a and 6b is also slidably fitted to a stem guide 8 press-fitted into the cylinder head 1, and is compressed between the cylinder head 1 and the flange 10 at the end of the valve stem. The attached valve spring 12 is urged in the valve closing direction.
[0018]
A camshaft 13 that is rotationally driven by a crankshaft of the internal combustion engine at a reduction ratio of ½ is rotatably supported by the cylinder head 1. The camshaft 13 includes an intake cam 14, a pair of exhaust pausing cams 15a and 15b positioned on both sides of the intake cam 14 along the camshaft 13, and an intake cam 14 with respect to both exhaust pausing cams 15a and 15b. A pair of exhaust cams 16a, 16b is provided on the side opposite to the certain side. The intake cam 14 has a profile composed of a lift part and a base circle part that opens and closes a pair of intake valves 5a and 5b during normal operation of the internal combustion engine. Both exhaust pausing cams 15a and 15b The exhaust valve 6a, 6b has a profile consisting only of a base circle that closes the exhaust valves 6a, 6b, and both exhaust cams 16a, 16b are lift parts that respectively open and close the pair of exhaust valves 6a, 6b during normal operation of the internal combustion engine And a base circle part.
[0019]
Between the pair of intake valves 5a and 5b and the camshaft 13, the first and second intake rocker arms 17 and 18 and the third intake rocker arm 19 located between the two intake rocker arms 17 and 18 are connected to the camshaft. 13 is supported in a swingable manner in parallel with an intake rocker arm shaft 20 fixed to the cylinder head 1 above 13. On the other hand, between the pair of exhaust valves 6a and 6b and the camshaft 13, the first and second exhaust rocker arms 21 and 22 and the third and third exhaust rocker arms 21 and 22 positioned on both sides of the exhaust rocker arms 21 and 22 are sandwiched. 4 Exhaust rocker arms 23 and 24 are supported in a swingable manner in parallel with an exhaust rocker arm shaft 25 fixed to the cylinder head 1 above the cam shaft 13.
[0020]
One end of each of the first and second intake rocker arms 17 and 18 is supported by the intake rocker arm shaft 20, and a tappet screw 26 that contacts the valve stem end of the intake valves 5a and 5b is advanced and retracted at the other end. A first connection switching mechanism M1, which will be described later, is provided at an intermediate portion thereof. As shown in FIG. 3, a roller 28 slidably contacting the intake cam 14 is pivotally supported at one end of the third intake rocker arm 19, and a first connection switching mechanism M1 is provided at the other end. The intermediate portion is supported by the intake rocker arm shaft 20. Therefore, the first and second intake rocker arms 17 and 18 are interlocked with both intake valves 5a and 5b, respectively, and the third intake rocker arm 19 is directly swung by the intake cam 14.
[0021]
On the other hand, in each of the first and second exhaust rocker arms 21 and 22, a roller 29 that is slidably in contact with the exhaust stop cams 15a and 15b and has a second connection switching mechanism M2 described later is pivotally supported at one end thereof. The other end portion is provided with a tappet screw 27 that abuts on the valve stem end portion of the exhaust valves 6a and 6b so as to be able to advance and retreat, and an intermediate portion thereof is supported by the exhaust rocker arm shaft 25. As shown in FIG. 7, the roller 29 includes an inner ring 29a press-fitted to the first and second exhaust rocker arms 21 and 22, an outer ring 29b slidably in contact with the exhaust stop cams 15a and 15b, an inner ring 29a and It is comprised from many rollers 29c arrange | positioned between the outer rings 29b. Further, in each of the third and fourth exhaust rocker arms 23 and 24, at one end thereof, a roller 30 which is in sliding contact with the exhaust cams 16a and 16b and incorporates the second connection switching mechanism M2 is pivotally supported. The end is supported by the exhaust rocker arm shaft 25. The roller 30 includes an inner ring 30a that is press-fitted and fixed to the third and fourth exhaust rocker arms 23 and 24, an outer ring 30b that is in sliding contact with the exhaust cams 16a and 16b, and a large number of rollers 30c that are disposed between the inner ring 30a and the outer ring 30b. Consists of Therefore, the first and second exhaust rocker arms 21 and 22 are interlocked with both exhaust valves 6a and 6b, respectively, and the third and fourth exhaust rocker arms 23 and 24 are directly oscillated by both exhaust cams 16a and 16b. Is done.
[0022]
Thus, the first and second intake rocker arms 17 and 18 are free rocker arms that can be free without being restricted by the movement of the intake cam 14, and the third intake rocker arm 19 includes both intake valves 5a, This is a free rocker arm that can be free for both intake valves 5a and 5b without opening and closing 5b. Similarly, the third and fourth exhaust rocker arms 23 and 24 are free rocker arms that can be free from the exhaust valves 6a and 6b without opening and closing the exhaust valves 6a and 6b. The one end portion of the third intake rocker arm 19 extends along the cam shaft 13 between the one end portion of the first exhaust rocker arm 21 and the one end portion of the second exhaust rocker arm 22 above the cam shaft 13. Located adjacent to each other in parallel.
[0023]
In the cylinder head 1, the cylinder arrangement direction of the three cylinders A 1, A 2, A 3, that is, the axial direction of the cam shaft 13, is located on the upper end surface opposite to the coupling surface with the cylinder block with the cam shaft 13 interposed therebetween. At L, the plate-like holder 50 shown in FIG. 2 is attached from the one end portion of the cylinder head 1 to the other end portion by bolts B1 to B10 (see FIG. 1) as ten fastening members.
[0024]
In the holder 50, the first and second intake rocker arms 17 and 18 for each of the cylinders A1, A2 and A3 are elastically moved toward the valve stem ends of both intake valves 5a and 5b via tappet screws 26, respectively. The first and second lost motion mechanisms 31, 32 and the third intake rocker arm 19 as urging members urged by the urging force are directed toward the intake cam 14 and the third lost as urging members urged by the elastic force. Fourth and fifth lost motion mechanisms 34 and 35 as urging members for urging the motion mechanism 33 and the third and fourth exhaust rocker arms 23 and 24 toward the exhaust cams 16a and 16b, respectively. However, first to fifth holding portions 51 to 55 that are mounted and held are formed. Furthermore, the holder 50 is formed with fastening portions C1 to C10 made of cylindrical bosses having bolt insertion holes corresponding to the bolts B1 to B10.
[0025]
Referring to FIG. 4, the first and second holding portions 51 and 52 have bottomed holes 51 a and 52 a, and are the sides on which the rocker arms 17 to 19 and 21 to 24 are disposed with respect to the holder 50. This is a bottomed holding portion having a bottomed part-cylindrical cylindrical shape having open ends 51b and 52b opened on the rocker arm side 50a. In the holder 50, the anti-rocker arm side 50b opposite to the rocker arm side 50a It protrudes.
[0026]
The first and second lost motion mechanisms 31 and 32 attached to the bottomed holes 51a and 52a have the same structure, and have top surfaces that are slidably fitted into the bottomed holes 51a and 52a, respectively. And the top surface of the piston 36 comes into contact with the contact surfaces 17a and 18a formed on the upper portions of the first and second intake rocker arms 17 and 18, respectively. A cylindrical coil spring 37 as a resilient member mounted between the piston 36 and the bottom surfaces of the holding portions 51, 52 to be biased by the resilient force toward the intake valves 5a, 5b, A retaining ring 38 is detachably mounted in a groove near the opening ends 51b and 52b on the inner surfaces of the holding portions 51 and 52.
[0027]
  Referring to FIG. 3, the third holding portion 53 is the rocker arm side 50 a of the holder 50.
A through-hole 53a that penetrates the anti-rocker arm side 50b and faces the third intake rocker arm 19, and has a first opening end 53b that opens to the rocker arm side 50a and a second opening end 53c that opens to the anti-rocker arm side 50b. This is a partially cylindrical cylindrical through-holding portion that protrudes toward the anti-rocker arm side 50 b of the holder 50.As shown in FIG. 3, the third holding portion 53 Is the third intake rocker arm 19 Is disposed on the opposite side of the cylinder head 1 across the cylinder.
[0028]
The third lost motion mechanism 33 mounted on the through hole 53a from the anti-rocker arm side 50b of the holder 50 is positioned near the first opening end 53b and is formed on the upper portion of the third intake rocker arm 19 The contact piece 41 that comes into contact with the surface 19a, the fixing piece 42 that is screwed into the screw portion 53d formed near the second opening end 53c inside the third holding portion 53, and the contact piece 41 3 A cylindrical coil spring 43 as a resilient member held between a fixed piece 42 and a contact piece 41 is provided to urge the three intake rocker arm 19 toward the intake cam 14 by its resilient force. The outer periphery of the coil spring 43 is in contact with the inner peripheral surface of the third holding portion, and the coil spring 43 is prevented from falling by being guided along the through hole 53a.
[0029]
The contact piece 41 includes a bowl-shaped retainer portion 41 a that contacts one end of the coil spring 43 and a columnar fitting portion 41 b that is fitted and held on the inner periphery of the coil spring 43. The fixed piece 42 is in contact with the other end portion of the coil spring 43 and has a retainer portion 42a having a screw portion 42d formed on the outer peripheral surface thereof, and a cylindrical fitting fitted and held on the inner periphery of the coil spring 43. It consists of a joint part 42b and a flange part 42c that comes into contact with the second opening end 53c. Further, in order to attach the third lost motion mechanism 33 to the third holding portion 53, the screw portion 42d of the fixing piece 42 and the screw portion 53d of the third holding portion 53 are screwed to the fixing piece 42, A hexagonal hole 42e, which is a tool insertion hole into which a tool for screwing the fixed piece 42 is inserted, is formed, and an oil supply hole 42f that penetrates the fitting portion 42e is formed at the bottom of the hexagonal hole 42e. The upper end portion of the oil supply hole 42f is open toward the upper space of the valve operating chamber, and the lower end portion thereof is open to the end surface on the contact piece 41 side of the fitting portion 42b. Therefore, in the space, the splash of lubricating oil supplied to the sliding portion of the valve operating device or the like is directly or directly attached to the fixed piece 42 through the oil supply hole 42f and becomes a liquid flow through the oil supply hole 42f. It is supplied to the contact piece 41 and the coil spring 43 of the third lost motion mechanism 33, and the sliding portions thereof are lubricated.
[0030]
  On the other hand, as shown in FIG. 5, the fourth and fifth holding portions 54 and 55, which hold the fourth and fifth lost motion mechanisms 34 and 35 having the same structure as the third lost motion mechanism 33, The third holding portion 53 has the same structure.Therefore, as shown in FIG. 5, the fourth and fifth holding portions 54 , 55 Are the third and fourth exhaust rocker arms, respectively. twenty three , twenty four Is disposed on the opposite side of the cylinder head 1 across the cylinder.Then, the contact pieces 41 of the fourth and fifth lost motion mechanisms 34 and 35 respectively contact the contact surfaces 23a and 24a (see FIG. 1) formed on the upper portions of the third and fourth exhaust rocker arms 23 and 24, respectively. It touches. The first to fifth holding portions 51 to 55 are inclined with respect to the coupling surface between the cylinder block and the cylinder head 1, that is, the first to fifth holding portions.51 ~ 55The holder 50 is provided such that the center line of the cylinder is inclined.
[0031]
Incidentally, the first connection switching mechanism M1 provided in the first, second, and third intake rocker arms 17, 18, and 19 includes a piston 60 and first and third intake rocker arms 17 as shown in FIG. , 19 can be connected, and the piston 60 and the connection pin 61 can be connected to the connection piston 62 that can restrict the movement of the piston 60 and the connection pin 61 and can connect the second and third intake rocker arms 18, 19. And a return spring 63 biased to the side.
[0032]
The first intake rocker arm 17 is formed with a bottomed guide hole 64 in which the piston 60 and the connecting pin 61 are slidably fitted so that the opening end thereof is on the third intake rocker arm 19 side. A hydraulic chamber 67 is formed between the bottom of 64. Further, the hydraulic chamber 67 is always in communication with the hydraulic supply path 69 (see FIG. 4) inside the intake rocker arm shaft 20 via the communication path 68 regardless of the swinging state of the first intake rocker arm 17. The third intake rocker arm 19 is formed with a guide hole 65 having the same diameter at a position corresponding to the guide hole 64 with both open ends thereof facing the first and second intake rocker arms 17 and 18, respectively. The connecting pin 61 and the connecting piston 62 are slidably fitted to each other. The second intake rocker arm 18 is formed with a bottomed guide hole 66 having the same diameter at a position corresponding to the guide hole 65 with the opening end thereof facing the third intake rocker arm 19, and a connecting piston 62 is connected to the guide hole 66. Are slidably fitted. The return spring 63 is attached to the inner periphery of the connecting piston 62 between the bottom of the guide hole 66 and the connecting piston 62 in a compressed state.
[0033]
  When the hydraulic pressure in the hydraulic chamber 67 of the first connection switching mechanism M1 is reduced by the hydraulic pressure of the hydraulic supply passage 69 controlled by the hydraulic control valve, the piston 60, the connection pin 61, and the connection piston 62 are returned to the return spring. The coupling pin 61 is fitted over both the guide holes 64, 65, and the coupling piston 62 is fitted over both the guide holes 65, 66. The first, second and third intake rocker arms 17, 18, and 19 are connected together. When the hydraulic pressure in the hydraulic chamber 67 is increased by the hydraulic control valve, the piston 60 moves to a position where the connecting pin 61 is pushed into the third intake rocker arm 19, and the contact surface between the piston 60 and the connecting pin 61 is reached. Is located between the first and third intake rocker arms 17 and 19, and the contact surface between the connecting pin 61 and the connecting piston 62 is located between the second and third intake rocker arms 18 and 19.PutTherefore, the first, second, and third intake rocker arms 17, 18, and 19 are in a disconnected state that is not connected.
[0034]
On the other hand, the second connection switching mechanism M2 provided in the first and third exhaust rocker arms 21 and 23 connects the piston 70 and the first and third exhaust rocker arms 21 and 23 as shown in FIG. A connecting pin 71 to be obtained, a restricting piston 72 for restricting the movement of the piston 70 and the connecting pin 71, and a return spring 73 for biasing the piston 70, the connecting pin 71 and the restricting piston 72 to the connecting side. The first exhaust rocker arm 21 is formed with a bottomed mounting hole 21a into which the inner ring 29a of the roller 29 is press-fitted and fixed, with the opening end thereof facing the third exhaust rocker arm 23, in a guide hole 74 formed in the inner ring 29a. The piston 70 and the connecting pin 71 are slidably fitted. A hydraulic chamber 76 formed between the piston 70 and the bottom of the bottomed mounting hole 21a is connected to a hydraulic pressure supply path 78 (see FIG. 4) inside the exhaust rocker arm shaft 25 and the first exhaust via a communication path 77. Regardless of the rocker arm 21 swinging state, it always communicates. Also, the third exhaust rocker arm 23 is formed with a bottomed mounting hole 23b into which the inner ring 30a of the roller 30 is press-fitted and fixed with the opening end thereof facing the first exhaust rocker arm 21. The connecting pin 71 and the regulating piston 72 are slidably fitted in guide holes 75 of the same diameter formed at corresponding positions. The return spring 73 is mounted in a compressed state between the bottom of the bottomed mounting hole 23b and the regulating piston 72 inside the regulating piston 72.
[0035]
When the hydraulic pressure in the hydraulic chamber 76 of the second connection switching mechanism M2 is lowered by the hydraulic pressure of the hydraulic pressure supply passage 78 controlled by the hydraulic control valve, the piston 70, the connecting pin 71, and the regulating piston 72 are returned to the return spring. By moving to the connecting side by the elastic force of 73, the connecting pin 71 is fitted over the guide holes 74, 75, and the first and third exhaust rocker arms 21, 23 are connected together. When the hydraulic pressure in the hydraulic chamber 76 is increased by the hydraulic control valve, the piston 70 moves to a position where the connecting pin 71 is pushed into the third exhaust rocker arm 23, and the contact surface between the piston 70 and the connecting pin 71 is reached. Is located between the first and third exhaust rocker arms 21 and 23, the first and third exhaust rocker arms 21 and 23 are in a disconnected state where they are not connected.
[0036]
The second and fourth exhaust rocker arms 22 and 24 are also provided with a second connection switching mechanism M2 having the same structure as the second connection switching mechanism M2 provided on the first and third exhaust rocker arms 21 and 23. When the hydraulic pressure in the hydraulic chamber 76 is low, the piston 70, the connecting pin 71, and the regulating piston 72 are moved to the connecting side by the elastic force of the return spring 73, and the connecting pin 71 enters the guide holes 74, 75. The second and fourth exhaust rocker arms 22 and 24 are fitted together so as to be connected together. When the hydraulic pressure in the hydraulic chamber 76 becomes high, the piston 70 moves to a position where the connecting pin 71 is pushed into the fourth exhaust rocker arm 24 and the contact surface between the piston 70 and the connecting pin 71 is the second and fourth exhaust rocker arm 22. , 24, the second and fourth exhaust rocker arms 22, 24 are in a disconnected state where they are not connected.
[0037]
Here, the cam shaft 13 provided with the cam, the rocker arms 17 to 19 and 21 to 24, the rocker arm shafts 20 and 25, the intake valves 5a and 5b, the exhaust valves 6a and 6b, the holder 50, and the above are attached thereto. A valve operating device is configured by the members to be operated.
[0038]
Next, with reference to FIGS. 1 and 2, the holding portions 51, 52, 53, 54, 55, the fastening portions C1 to C10, and the reinforcing ribs protruding to the anti-rocker arm side 50b are integrally formed by casting. The holder 50 is further described.
In the cylinder A1, side surfaces of the first and second holding portions 51 and 52 are directly connected to both side surfaces in the axial direction L of the cam shaft 13 of the third holding portion 53.
[0039]
Positioned on the opposite side of the third holding portion 53 to the side where the second opening end 53c is present with respect to the axis of the cam shaft 13, passes through the center line of the cylinder of the third holding portion 53, and is orthogonal to the axis of the cam shaft 13. The fourth and fifth holding portions 54 and 55 are disposed so that the second opening ends 54c and 55c are positioned substantially symmetrically with respect to the plane P to be formed, and are formed by thinning between the holding portions 54 and 55. The upper portions of the first and second exhaust rocker arms 21 and 22 enter the recessed portion 56. The arrangement of the first to fifth holding portions 51, 52, 53, 54, 55 in the holder 50 is the same for the remaining two cylinders A2, A3. Further, a pipe 39 into which a spark plug is inserted is disposed between the first and second exhaust rocker arms 21 and 22 and near the end where the tappet screws 27 and 27 are provided.
[0040]
Further, fastening portions C1 to C10 through which bolts B1 to B10 for fastening the holder 50 to the cylinder head 1 are inserted and fastened are arranged as follows.
Of the three cylinders A1, A2, A3 arranged in a row, the cylinder A1 located at one end is closest to one end of the holder 50 among the holding portions 51, 52, 53, 54, 55 of the cylinder A1. Position where the fastening portion C1 is directly connected to the side surface of the fourth holding portion 54 on the side of the fourth holding portion 54 located on the side near the one end portion of the holder 50 in the axial direction L of the camshaft 13 Provided.
[0041]
In the first and second holding portions 51 and 52, two fastening portions C2 and C3 are provided on the side opposite to the side where the third holding portion 53 is located in the axial direction L of the camshaft 13. The fourth ribs 84 and 84 respectively connect the side surfaces of the third holding portion 53 and the side surfaces of the fastening portions C2 and C3.
[0042]
Further, among the holding portions 51 to 55 of the cylinder A1, the fastening portion C4 is located on the side of the fifth holding portion 55 located closest to the cylinder A2 and closer to the cylinder A2 in the axial direction L of the camshaft 13. It is provided at a position where the side surface of the fifth holding portion 55 is directly connected. Further, in the fastening portion C4, the side surface opposite to the side where the fifth holding portion 55 is located in the axial direction L of the camshaft 13 is located closest to the cylinder A1 in the holding portions 51 to 55 of the cylinder A2. 4 It is directly connected to the side surface of the holding portion 54.
[0043]
The cylinders A2 and A3 are also arranged with holding parts 51 to 55 and fastening parts C4 to C7 similar to the cylinder A1. That is, in the cylinder A2, the fastening portion C4 is directly connected to the side surface of the fourth holding portion 54 on the side near the cylinder A1 in the axial direction L of the cam shaft 13 of the fourth holding portion 54 as described above. Provided. Further, in the first and second holding portions 51 and 52, the side surfaces of the two fastening portions C5 and C6 provided on the side in the axial direction L of the camshaft 13 are the first and second holding portions 51 and 52, respectively. Are connected by a fourth rib 84 provided between the side surfaces thereof. Furthermore, the fastening portion C7 whose side surface is directly connected to the side surface of the fourth holding portion 54 in the cylinder A3 is on the opposite side of the axial direction L of the cam shaft 13 from the side where the fourth holding portion 54 is located in the cylinder A3. The side surface is provided at a position that is directly connected to the side surface of the fifth holding portion 55 located closest to the cylinder A3 among the holding portions 51 to 55 of the cylinder A2.
[0044]
Similarly, in the cylinder A3, the fastening portion C7 is provided at a position directly connected to the side surface of the fourth holding portion 54 on the side near the cylinder A2 in the axial direction L of the cam shaft 13 of the fourth holding portion 54. It is done. Further, in the first and second holding portions 51 and 52, the side surfaces of the two fastening portions C8 and C9 provided on the side in the axial direction L of the camshaft 13 are the first and second holding portions 51 and 52, respectively. Are connected by fourth ribs 84 and 84 provided between the side surfaces of the first and second sides. Further, the fastening portion C10 has a side surface of the holder 50 in the axial direction L of the cam shaft 13 of the fifth holding portion 55 that is located closest to the other end of the holder 50 among the holding portions 51 to 55 of the cylinder A3. It is provided at a position where it is directly connected to the side surface of the fifth holding portion 55 on the side near the other end.
[0045]
Of these fastening portions C1 to C10, adjacent cylinders A1, C1, C2, C3, C1 and C3 are adjacent to each other on the side where the first, second, and third holding portions 51, 52, and 53 are directly connected to the camshaft 13. Between the fastening portions C3 and C5 between A2 and between the fastening portions C6 and C8 between the cylinders A2 and A3, and close to the end of the holder 50 of the fastening portions C2 and C9 located at the ends of the cylinders A1 and A3 at both ends In the cylinder head 1 corresponding to the position of the recess 57, a connecting member for connecting the cylinder head 1 to the cylinder block, for example, an insertion hole 58 through which a bolt is inserted, is formed. It is formed. Further, in the fastening portions C3, C5, C6, and C8 between the adjacent cylinders, a cutout portion 59 is provided on the opposite side portion so that the coupling member and the fastening portions C3, C5, C6, and C8 do not interfere with each other. Further, in the fastening portions C2 and C9 positioned near both end portions, the same notch portion 59 is provided in a portion near the end portions.
[0046]
Further, in the first and second lost motion mechanisms 31 and 32, when both intake valves 5a and 5b are closed, and in the third and fourth and fifth lost motion mechanisms 33 to 35, the intake cam 14 or the exhaust gas is exhausted. When the third intake rocker arm 19 or the third and fourth exhaust rocker arms 23, 24 are swung by the cams 16a, 16b, the spring force due to the compression of the coil spring 37 or the coil spring 43 acts on the holding portions 51-55. In view of this, the holder 50 is provided with a plurality of ribs for increasing its rigidity in order to resist the applied load and to suppress the occurrence of vibration due to the operation of the valve system. Among these ribs, the first rib 81 is connected to the side surface of the cam shaft 13 in the axial direction L at a substantially central position in the center line direction length of the third holding portion 53 of each cylinder A1, A2, A3. , And extends linearly along the axial direction L of the camshaft 13.
[0047]
Further, the second rib 82 is configured such that, in each of the cylinders A1, A2, and A3, the side surfaces of both of the cylinders A1, A2, and A3 are disposed along the plane including the center line of the fourth holding portions 54, 54, 54 and the center lines of the fastening portions C2, C5, A rib 82a that extends linearly so as to be connected, and a straight line that connects both side surfaces along a plane that includes the center line of the fifth holding portions 55, 55, 55 and the center line of the fastening portions C3, C6, C9. It is comprised from the rib 82b extended in a shape. The second rib 82 crosses the first rib 81 between the fourth and fifth holding portions 54 and 55 connected to each other and the fastening portions C2, C5, C8, C3, C6, and C9. In the embodiment, it extends so as to be substantially orthogonal, and is connected to the first rib 81 at the intersection.
[0048]
In the cylinder A1, the third rib 83 is connected to the connecting portion D of the third holding portion 53 with the first rib 81, the side surface of the fastening portion C1 directly connected to the side surface of the fourth holding portion 54, and the fifth holding portion. In order to connect the side surface of 55 and the side surface of the fastening portion C4 directly connected, it extends linearly. Further, the third rib 83 is the same as the cylinder A1 in the cylinders A2 and A3. For the cylinder A2, the connection portion D with the first rib 81 of the third holding portion 53, the side surface of the fastening portion C4, and the fastening portion The cylinder A3 extends in a straight line to connect the side surface of the portion C7, and for the cylinder A3, the connection portion D with the first rib 81 of the third holding portion 53, the side surface of the fastening portion C7, and the side surface of the fastening portion C10 To extend in a straight line. The third rib 83 intersects the second rib 82 in the vicinity of the fourth and fifth holding portions 54 and 55 and is connected to the second rib 82 at the intersecting portion.
[0049]
In the valve train configured as described above, when the internal combustion engine is operated, the hydraulic chamber 67 of the first connection switching mechanism M1 is set to a low pressure during the normal operation in which the cylinder deactivation operation is not performed. 2, the third intake rocker arms 17, 18, and 19 are in a connected state, and the first and second intake rocker arms 17, 18 that contact the pair of intake valves 5a and 5b by the intake cam 14 that the third intake rocker arm 19 is in sliding contact with. Oscillates integrally with the third intake rocker arm 19, so that both intake valves 5a and 5b are opened and closed by a valve opening characteristic determined by the intake cam 14. Therefore, the first and second intake rocker arms 17 and 18 are indirectly swung by the both intake cams 14, and the third intake rocker arm 19 is interlocked with the intake valves 5a and 5b.
[0050]
On the other hand, at this time, since the hydraulic chambers 76 of the second connection switching mechanisms M2 and M2 are set to low pressure, the first and third exhaust rocker arms 21 and 23 and the second and fourth exhaust rocker arms 22 and 24 are respectively The first exhaust rocker arm 21 in contact with the exhaust valve 6a is connected to the third exhaust rocker arm 23 and the exhaust valve 6b by exhaust cams 16a and 16b which are in a connected state and in which the third and fourth exhaust rocker arms 23 and 24 slidably contact, respectively. Since the abutting second exhaust rocker arm 22 swings integrally with the fourth exhaust rocker arm 24, both exhaust valves 6a and 6b are opened and closed with valve opening characteristics determined by the exhaust cams 16a and 16b, respectively. Therefore, the first and second exhaust rocker arms 21 and 22 are indirectly swung by both exhaust cams 16a and 16b, respectively, and the third and fourth exhaust rocker arms 23 and 24 are interlocked with both exhaust valves 6a and 6b, respectively. To do.
[0051]
During cylinder deactivation operation in which the internal combustion engine is operated in an engine operation range that emphasizes fuel consumption such as a low-load operation range, the hydraulic chamber 67 of the first connection switching mechanism M1 is at a high pressure, so the first, second, third Since the intake rocker arms 17, 18, and 19 are in a disconnected state and the opening force of the intake cam 14 is not transmitted to the pair of intake valves 5a and 5b via the third intake rocker arm 19, both intake valves 5a and 5b 5b is normally closed.
[0052]
The first and second intake rocker arms 17 and 18 always maintain an appropriate valve clearance even during the cylinder deactivation operation by the elastic force of the coil springs 37 of the first and second lost motion mechanisms 31 and 32. Yes. In addition, the third intake rocker arm 19 is idled while being slidably contacted with the intake cam 14 by the elastic force of the coil spring 43 of the third lost motion mechanism 33, but the third lost motion mechanism 33 As the coil spring 43 expands and contracts, the third intake rocker arm 19 is prevented from rampage.
[0053]
  Further, since the hydraulic chambers 76 of both the second connection switching mechanisms M2 and M2 are set to high pressure, the first and third exhaust rocker arms 21 and 23 and the second and fourth exhaust rocker arms 22 and 24 are in a disconnected state, respectively. The third and fourth exhaust rocker arms 23 and 24 are respectively provided by idle exhaust cams 16a and 16b which are in sliding contact with each other.AlwaysWhen the valve is closed. The third and fourth exhaust rocker arms 23 and 24 are urged so as to be in sliding contact with the exhaust cams 16a and 16b by the elastic force of the coil springs 43 of the fourth and fifth lost motion mechanisms 34 and 35, respectively. However, the coil springs 43 of the fourth and fifth lost motion mechanisms 34 and 35 expand and contract, thereby preventing the third and fourth exhaust rocker arms 23 and 24 from moving up and down.
[0054]
The operation and effect of the embodiment configured as described above will be described below. Since the first, second, and third holding portions 51, 52, and 53 that hold the first, second, and third lost motion mechanisms 31, 32, and 33 are directly connected and integrated, the holding portions are provided. Since 51 to 53 reinforce each other, the rigidity between the holding parts 51 to 53 is increased, so that deformation between the holding parts 51 to 53 can be suppressed, and the malfunction of each lost motion mechanism 31 to 33 occurs. For example, the elastic force becomes weaker than the set elastic force of the coil springs 37, 43, the acting direction of the elastic force deviates from the set direction, the piston 36 and the first and second holding portions 51, 52. The smooth movement of the sliding portion between the inner peripheral surface of the coil spring 43 and the sliding portion between the coil spring 43 and the inner peripheral surface of the third holding portion 53 is prevented from being smoothly performed.
[0055]
Further, by using the mutual holding portions 51 to 53 themselves, the rigidity between the holding portions 51 to 53 can be increased without adding a new reinforcing structure to the holder 50, so that an increase in the weight of the holder 50 is suppressed. it can. Further, since the holding portions 51 to 53 are directly connected and integrated in a state in which the holding portions 51 to 53 are arranged in parallel in the axial direction L of the cam shaft 13, the width of the cam shaft 13 of the holding portions 51 to 53 arranged in parallel is increased in width. The three holding portions 51 to 53 can be compactly arranged, and the size of the internal combustion engine in the cylinder arrangement direction can be reduced.
[0056]
The first, second, and third holding portions 51, 52, and 53 that are directly connected and integrated are the first and second holding portions 51 and 52 that are bottomed holding portions and the first holding portion that is a through-holding portion. 3 holding part 53 combination. As a result, the integrated holding portions 51, 52, 53 include the first and second holding portions 51, 52 having bottoms instead of the through holes, and thus the first, second, and third holding portions 51 are included. , 52, 53, and at the same time, after attaching the holder 50 to the cylinder head 1, by using the through hole 53a, the rocker arms 17-19, 21-24, etc. Since the third lost motion mechanism 33 can be attached to the third holding portion 53 from the second opening end 53c that opens to the anti-rocker arm side 50b that is the side without the valve operating mechanism, the lost motion mechanism can be easily attached and lost. Assembling workability of the motion mechanism can be improved.
[0057]
The first, second, and third holding portions 51, 52, and 53 in which the holding portions are directly connected are the first and second ribs 81 and 82 and the third and fourth ribs 83 that are connected to the fastening portions C1 to C10. , 84, and the fourth and fifth holding portions 54, 55 are bolts B1, B4, B7, B10 inserted into the fastening portions C1, C4, C7, C10 and the fastening portions C2, C3, C5, C6, Since it is connected to the second and third ribs 82 and 83 connected to C8 and C9, the rigidity of the entire holder 50 is increased, the operation of the valve operating device is stabilized, vibrations are suppressed, and noise is reduced. To reduce.
[0058]
Since each of the fourth and fifth holding portions 54 and 55 is directly connected and integrated with the fastening portions C1, C4, C7 and C10 coupled to the cylinder head 1 in the holder 50, the holding portions 54, As a result of the increased rigidity between 55, the deformation between the holding portions 54 and 55 can be suppressed, and the occurrence of defects in the fourth and fifth lost motion mechanisms 34 and 35 can be suppressed. Further, the vicinity of the fastening portions C1, C4, C7, and C10 where the holding portions 54 and 55 are located has high rigidity, so that the fourth and fourth exhaust rocker arms 23 and 24 are driven based on the swing of the third and fourth exhaust rocker arms 23 and 24. 5 Deformation of the entire holder 50 due to a load acting via the lost motion mechanisms 34 and 35 can be suppressed.
[0059]
The holder 50 has a first rib 81 extending along the axial direction L of the camshaft 13 and connecting the third holding portions 53 of the cylinders A1, A2, and A3, and fourth and fifth holding portions 54 and 55. And a second rib 82 for connecting the fastening portions C2, C3, C5, C6, C8, and C9, respectively. The second rib 82 is connected to the fourth holding portion 54 and the fastening portions C2, C5, and C8. And between the fifth holding part 55 and the fastening parts C3, C6, C9. As a result, since the first rib 81 and the second rib 82 intersect with each other, the overall rigidity of the holder 50 is increased, so that the occurrence of problems with the lost motion mechanisms 31 to 35 is further suppressed. The operation of the valve gear is stabilized, and furthermore, vibration is suppressed and noise is reduced. Furthermore, when the first rib 81 and the second rib 82 intersect substantially orthogonally as in the embodiment, the rigidity is further enhanced.
[0060]
In the holder 50, a recess 56 is formed between the fourth and fifth holding portions 54, 55, and between the fastening portions C3, C5, between the fastening portions C6, C8, and between the fastening portions C2, C9 located at both ends. Since the recess 57 is formed near the end, the holder 50 can be reduced in weight, and the internal combustion engine can be reduced in weight.
[0061]
Further, the first to fifth holding portions 51 to 55 are provided on the holder 50 so as to be inclined with respect to the coupling surface between the cylinder block and the cylinder head 1, and the fourth and fifth holding portions 54 and 55. By allowing the upper portions of the first and second exhaust rocker arms 21 and 22 to enter the recess 56 therebetween, it is possible to reduce the size in the axial direction of the cylinder of the internal combustion engine and make the internal combustion engine compact. it can.
[0062]
Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
In the above embodiment, the three holding parts 51, 52, 53 are directly connected to each other. However, if there are two or more holding parts connected directly to each other, Good. In the above-described embodiment, the valve operating apparatus is a valve operating apparatus that performs cylinder deactivation. However, without performing cylinder deactivation, the intake valve and the exhaust valve are always opened and closed during engine operation, and the valve is operated according to the engine operation state. Further, the valve operating device may be provided with a mechanism for changing valve operation characteristics such as a lift amount.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part of a three-cylinder cylinder head forming one bank of an internal combustion engine to which the present invention is applied.
FIG. 2 is a plan view of a holder.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a cross-sectional view taken along line VV in FIG.
6 is a cross-sectional view taken along line VI-VI in FIG.
7 is a cross-sectional view taken along line VII-VII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 2 ... Combustion chamber, 3 ... Intake port, 4 ... Exhaust port, 5a, 5b ... Intake valve, 6a, 6b ... Exhaust valve, 7, 8 ... Stem guide, 9, 10 ... Saddle part, 11, 12 ... Valve spring, 13 ... Cam shaft, 14 ... Intake cam, 15a, 15b ... Exhaust stop cam, 16a, 16b ... Exhaust cam, 17, 18, 19 ... Intake rocker arm, 20 ... Intake rocker arm shaft, 21, 22, 23 24 ... Exhaust rocker arm, 25 ... Exhaust rocker arm shaft, 26, 27 ... Tappet screw, 28 ... Roller, 29, 30 ... Roller, 31-35 ... Lost motion mechanism, 36 ... Piston, 37 ... Coil spring, 38 ... Retaining ring , 39 ... pipe,
41 ... contact piece, 42 ... fixed piece, 43 ... coil spring,
50 ... Holder, 51-55 ... Holding part, 51a, 52a ... Bottomed hole, 53a ... Through hole, 53c ... Second open end, 56, 57 ... Recessed part, 58 ... Insertion hole, 59 ... Notch part,
60 ... Piston, 61 ... Connecting pin, 62 ... Connecting piston, 63 ... Return spring, 64, 65, 66 ... Guide hole, 67 ... Hydraulic chamber, 68 ... Communication passage, 69 ... Hydraulic supply passage, 70 ... Piston, 71 ... Connecting pin, 72 ... Regulating piston, 73 ... Return spring, 74,75 ... Guide hole, 76 ... Hydraulic chamber, 77 ... Communication passage, 78 ... Hydraulic supply passage,
81 ... 1st rib, 82 ... 2nd rib, 84 ... 3rd rib, 84 ... 4th rib,
A1, A2, A3 ... Cylinder, B1-B10 ... Bolt, C1-C10 ... Fastening part, D ... Connection part, L ... Axial direction of camshaft, M1, M2 ... Connection switching mechanism, P ... Plane.

Claims

A plurality of urging members for urging a plurality of rocker arms, which can be directly or indirectly swung by a cam provided on the camshaft and interlocked with the engine valve, by an elastic force toward the engine valve or the cam; A valve operating apparatus for an internal combustion engine comprising a holder provided with a plurality of holding portions attached to the cylinder head and holding the biasing members,
Between at least two of said holding portion are integrated is directly connected to said holder includes a first rib for connecting said holding portion each other extends along the axial direction of the camshaft, the first A second rib that connects the holding portion different from the holding portion connected to the rib and a fastening portion of the holder for attaching the holder to the cylinder head is provided. A valve operating device for an internal combustion engine, wherein the valve operating device is connected to the first rib between the connecting holding portion and the fastening portion .

The at least two holding portions connected directly have a bottomed holding portion having a bottomed hole and an open end opened to the rocker arm side of the holder, a through hole penetrating the holder, and the rocker arm side And a through-holding portion having a second opening end that opens to the side opposite to the rocker arm of the holder, and the through-holding portion is disposed on the opposite side of the cylinder head across the rocker arm. A part of the urging member is held in the bottomed hole of the bottomed holding part, and the through hole of the penetration holding part passes through the piercing member from the second opening end. 2. The valve operating apparatus for an internal combustion engine according to claim 1, wherein an urging member formed so as to be attachable to the hole is held.

A plurality of urging members for urging a plurality of rocker arms, which can be directly or indirectly swung by a cam provided on the camshaft and interlocked with the engine valve, by an elastic force toward the engine valve or the cam; A valve operating apparatus for an internal combustion engine comprising a holder provided with a plurality of holding portions attached to the cylinder head and holding the biasing members,
At least two of said holding portion, directly connected with the fastening portion of the holder for respective retaining portion attaching the holder to the cylinder head are coupled together via the fastening portion, said holder A first rib that extends along the axial direction of the cam shaft and connects the holding portions to each other, and the holding portion and the holder that are different from the holding portion connected to the first rib, to the cylinder head A second rib that connects the fastening portion of the holder for mounting is provided, and the second rib is connected to the first rib between the holding portion and the fastening portion that are connected. A valve operating apparatus for an internal combustion engine.