JP4552376B2

JP4552376B2 - Infinite transmission

Info

Publication number: JP4552376B2
Application number: JP2002347350A
Authority: JP
Inventors: 久則白井
Original assignee: Equos Research Co Ltd
Current assignee: Equos Research Co Ltd
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2010-09-29
Anticipated expiration: 2022-11-29
Also published as: JP2004176890A

Description

【０００１】
【発明の属する技術分野】
本発明は、変速機に関し、特に無段変速機構と遊星歯車機構の組み合わせにより無限変速を行なう無限変速機に関する。
【０００２】
【従来の技術】
車載用自動無段変速機として、無段変速機構と遊星歯車機構を組み合わせ、変速機にトルク循環を生じさせることで出力回転０の状態（ギヤニュートラル：ＧＮ）を実現できる態様（ｌｏｗモード）と、エンジントルクを専ら無段変速機構を経てダイレクトに出力する態様（ｈｉｇｈモード）との切替が可能ないわゆる無限変速機（ＩＶＴ：Infinitely Variable Transmission）が知られている。こうしたＩＶＴにおける無段変速機構は、一般に、変速比（入出力回転数比）を目標値として制御される。しかしながら、前記ギヤニュートラル状態を変速比の制御に追従させて瞬時かつ変動なく得ることは困難である。この理由として、例えば応答遅れ、制御誤差、機構の組み付け誤差、回転数の計測誤差などの存在が挙げられる。
【０００３】
そこで、従来、無段変速機構にベルト式無段変速機構を用いたＩＶＴにおいて、ギヤニュートラル状態に自己収束するようにベルト式無段変速機構のプライマリ及びセカンダリのプーリ軸力を等しくするように制御する技術、すなわち、無段変速機構を、その制御目標値として変速比でなく、出力トルクで制御する技術が提案されている（特許文献１参照）。同じくベルト式無段変速機構を用いた他の技術として、発進装置に流体伝動装置を用いる在来の遊星歯車式自動変速機のように、ギヤニュートラル状態でも所望のクリープ力が出力されるように、ベルト式無段変速機構のプーリ軸力を制御する技術があり、これも同様に無段変速機構の制御目標値として出力トルクを用いた例である（特許文献２参照）。
【０００４】
【特許文献１】
特開平８−２６１３０３号公報
【特許文献２】
特開平１０−１１０８０２号公報
【０００５】
また、前記両従来技術では、ＩＶＴの無段変速機構にベルト式の変速機構が用いられているが、これにトロイダル方式等の他の無段変速機構を用いることも可能である。トロイダル方式の無段変速機構を用いた無限変速機の例としては例えば、次の技術がある（非特許文献１参照）。なお、ＩＶＴの仕組みについては、次の文献が詳しい（非特許文献２参照）。
【０００６】
【非特許文献１】
「ＫＯＹＯＥｎｇｉｎｅｅｒｉｎｇＪｏｕｒｎａｌ」，Ｎｏ．１６１、ｐ．１８−２５
【非特許文献２】
「ＫＯＹＯＥｎｇｉｎｅｅｒｉｎｇＪｏｕｒｎａｌ」，Ｎｏ．１６０
【０００７】
【発明が解決しようとする課題】
一般的に無段変速機搭載車両は、要求出力に対し無段変速の効果によりエンジン（本明細書において、内燃機関又は外燃機関等の燃焼機関を意味する）を効率の良いポイント（回転数、トルク）で運転することができ、その結果、高燃費が期待できる。しかし、無段変速機構そのものの伝達効率はあまり良くなく、高速走行時など変速機構の最オーバドライブ状態（速度比最大となるギヤ比を意味する）で長時間走行する場合などは、その伝達効率の悪さから、伝達効率の良い歯車式多段変速機搭載車両より燃費が劣ってしまう。この点は、無段変速機構を用いるＩＶＴの場合でも同様であり、高速走行時の燃費は歯車式多段変速機に劣ってしまう。
【０００８】
そこで、本発明は、上記のような課題を解決すべく、無段変速機構が最オーバドライブ付近で動力を伝達する状態において、無段変速機構を介するトルク伝達をなくすことができ、無限変速機の伝達効率を向上させ、変速機搭載車両の走行燃費の改善に資することができる無限変速機を提供することを目的とする。
また、無段変速機構が最オーバドライブ付近で動力を伝達する状態において、無段変速機構を介するトルク伝達をなくすことによって、無限変速機の伝達効率を向上させ、変速機搭載車両の走行燃費の改善に資するようにした無限変速機を提供することを他の目的とする。
【０００９】
【課題を解決するための手段】
前記の目的は、基本構成として、エンジンと連結された無限変速機の入力軸と、無限変速機の出力軸と、少なくとも第１、第２の二つの入力要素及び一つの出力要素の３要素を備えた遊星歯車機構と、前記第１の入力要素と前記無限変速機の出力軸とを係脱連結する第１のクラッチと、前記出力要素と前記無限変速機の出力軸とを係脱連結する第２のクラッチと、前記出力要素を回転不能に拘束するブレーキと、無段変速を行う無段変速機構とを有するとともに、該無段変速機構の入力軸は、前記無限変速機の入力軸と連結されるとともに、前記第２の入力要素と駆動連結され、前記無段変速機構の出力軸は前記第１の入力要素と連結されることを特徴とする構成によって達成される。
また、前記構成において、前記ブレーキが前記出力要素を回転不能に拘束するときに、前記第２のクラッチは、無段変速機構を通る動力の伝達を遮断する構成を採るのも有効である。
【００１０】
そして、前記構成において、前記無段変速機構の入力軸は、動力伝達経路上において、無限変速機の入力軸と前記第２の入力要素とが駆動連結される部位より下流において、第３のクラッチを介して、前記無限変速機の入力軸と連結される構成を採るのも有効である。
この場合、前記第３のクラッチは、第１のクラッチの係合による第１の入力要素からの出力時において、該第１の入力要素の速度比に応じて出力要素の空転速度が０となるときに解放される。
【００１１】
また、前記構成において、前記ブレーキは、第１のクラッチの係合による第１の入力要素からの出力時において、該第１の入力要素の速度比に応じて出力要素の空転速度が０となるときに係止させられて、出力要素を回転不能に拘束する。この場合、前記ブレーキが係止させられ、前記出力要素が回転不能に拘束された状態で、無段変速機構におけるトルク伝達が０となるように制御が行われる。
具体的には、前記無段変速機構が、プライマリプーリとセカンダリプーリとの間にベルトを巻き掛け、各プーリとベルトとの圧接力に応じてトルクを伝達するベルト式無段変速機構である場合、トルク伝達が０となる制御は、前記圧接力を調節することによって行われる。
また、前記無段変速機構が、入力ディスクと出力ディスクとの間に挟持されたローラを備え、ローラの位置を調節することによってトルクを伝達するトロイダル式無段変速機構である場合、トルク伝達が０となる制御は、前記ローラの位置の調節のための駆動力をなくすことによって行われる。
【００１２】
【作用】
本発明の請求項１に記載の構成においては、第２のクラッチの係合による出力状態では、無限変速機に入力される動力が、遊星歯車機構に第２の入力要素から入力され、出力要素から第２のクラッチを経て出力軸に出力されるとともに、第１の入力要素が受ける反力が無段変速機構にも伝達され、これにより遊星歯車機構及び無段変速機構を通るトルク循環が生じる。この状態では、無段変速機構の変速比を変更することによって逆回転出力から０回転のギヤニュートラルを経て正回転のある程度までの増速速度比の出力がなされる。また、第１のクラッチの係合による出力状態では、遊星歯車機構が出力要素の空転で動力を伝達しなくなるため、無限変速機に入力される動力は専ら無段変速機構を通り遊星歯車機構の第１の入力要素を通過し、第１のクラッチを経て出力軸に出力される状態になる。そして、この状態で無段変速機構の変速比を上げて行くと、出力の最大速度比付近で、それまで低下を続けてきた遊星歯車機構の出力要素の空転速度比は０に近付いていく。このとき、ブレーキを係合させることによって、出力要素は反力要素として作用するようになり、以後無段変速機構の変速比をブレーキ係合時の変速比に保つことで、動力は専ら遊星歯車機構を通り第１のクラッチを経て出力される状態が続く。
【００１３】
次に、請求項２に記載の構成においては、クラッチの切換えによるローモード時には、無限変速機に入力される動力が、遊星歯車機構を経て出力されるとともに、無段変速機構にも伝達され、これにより遊星歯車機構及び無段変速機構を通るトルク循環が生じる。この状態では、無段変速機構の変速比を変更することで逆回転出力から０回転のギヤニュートラルを経て正回転のある程度までの増速速度比の出力がなされる。また、ハイモード時には、動力が専ら無段変速機構を経て出力される状態になる。そして、この状態で無段変速機構の変速比を上げて行くと、出力の最大速度比付近で、それまで低下を続けてきた遊星歯車機構の空転要素の速度比が０となる作動が生じる。このとき、ブレーキを係合させることによって、空転要素は反力要素として作用するようになり、以後無段変速機構の変速比をこのときの変速比に保つことで、動力は専ら遊星歯車機構経由で出力される状態が続く。
また、請求項３に記載の構成においては、無段変速機構を通る動力伝達が機械的にも遮断される。
そして、請求項５に記載の構成においては、無段変速機構を通る動力伝達は第３のクラッチの解放によって遮断される。
【００１４】
さらに、請求項４に記載の構成においては、ブレーキの係合時期を、出力の最大速度比付近で、遊星歯車機構の出力要素の空転速度比が０となる時期と一致させることによってブレーキの係合が容易に行われる。そして、ブレーキの係合によりそれまで空転していた出力要素が反力要素として作用する。したがって、このときの無段変速機構の変速比を保つことで、動力は専ら遊星歯車機構を通り第１のクラッチを経て出力される状態が続く。
また、請求項６に記載の構成においては、変速比の積極的保持により、遊星歯車機構のみの動力伝達による出力状態が確実に継続する。
そして、請求項７に記載の構成においては、無段変速機構をベルト式無段変速機構とし、プーリとベルトとの圧接力の調節により前記の作用が生じる。
さらに、請求項８に記載の構成においては、無段変速機構をトロイダル式無段変速機構とし、ローラ位置の調節のための駆動力をなくすことにより前記の作用が生じる。
そして、請求項９に記載の構成においては、ブレーキの係合時期と第３のクラッチの解放時期とが出力の最大速度比付近で、遊星歯車機構の出力要素の空転速度比が０となる作動と完全に一致すると、無段変速機構を介する動力伝達は変速比の如何に関わりなく遮断され、動力は専ら遊星歯車機構を通り第１のクラッチを経て出力される状態が続く。
【００１５】
【発明の実施の形態】
以下、図面を参照して、本発明の実施形態を説明する。先ず、図１は、この発明の適用に係る無限変速機の第１実施形態の構成をスケルトンで示す。この無限変速機１は、無段変速機構４と、遊星歯車機構５と、動力伝達経路を切換えるクラッチ６，７との組合わせからなり、入力される動力を無段変速機構４と遊星歯車機構５とを通る動力伝達によりトルク循環を生じつつ出力するローモードと、無段変速機構４を通る動力伝達により出力するハイモードにより無限変速を達成する無限変速機を構成しており、本発明の特徴に従い、ハイモードにおける最大速度比付近で、遊星歯車機構５の空転要素５３の回転を拘束するブレーキ８を備え、ブレーキ８の係止により動力伝達経路を遊星歯車機構５を通る動力伝達に切換える作動を生じるものである。
【００１６】
具体的には、変速機１は、エンジン２に連結される入力軸１１と、無段変速機構４と、第１及び第２の２つの入力要素５１，５２と１つの出力要素５３の３要素を有する遊星歯車機構５と、該遊星歯車機構５の第１の入力要素５１を変速機１の出力軸１２に係脱連結する第１のクラッチ６と、出力要素５３を変速機１の出力軸１２に係脱連結する第２のクラッチ７とを備え、無段変速機構４は、その入力軸４１を変速機１の入力軸１１に連結されるとともに遊星歯車機構５の第２の入力要素５２に駆動連結され、出力軸４２を第１の入力要素５１に連結されており、更に、遊星歯車機構５の出力要素５３を回転不能に拘束するブレーキ８が設けられている。
【００１７】
そして、ブレーキ８は、第１のクラッチ６の係合による第１の入力要素５１からの出力時における出力要素５３の空転速度が０となるときに係止されて、出力要素５３を回転不能に拘束するように制御される。これに対して、無段変速機構４は、ブレーキ８の係止による遊星歯車機構５の出力要素５３の回転不能拘束時に、無段変速機構４の入力軸４１から出力軸４２へのトルク伝達が０となるように制御される。
【００１８】
より具体的には、変速機１は、その入力軸１１を図示しないドライブプレートを介してエンジン２に連結可能とされ、入力軸１１に対して平行軸の出力軸１２をディファレンシャル装置とユニバーサルジョイントを介して車軸に連結可能とされている。無段変速機構４は、平行軸すなわち入力軸４１と出力軸４２間で動力を伝達すべく、入力軸１１側に配設されたプライマリプーリ４３と出力軸４２側に配設されたセカンダリプーリ４４との間にベルト４５を巻き掛け、それぞれのプーリに対する巻き掛け部分の幅を制御することで無段変速を可能とする周知のベルト式無段変速機構とされている。遊星歯車機構５は、サンギヤ５１と、それに外接噛合する複数のピニオンギヤを回転自在に支持するキャリヤ５２と、ピニオンギヤに内接噛合するリングギヤ５３とからなるシンプルプラネタリギヤセットとされている。第１のクラッチ６と第２のクラッチ７は、特にその形式を問うものではないが、本形態では、いずれもハブとドラム間に多板の摩擦材を配し、これを油圧サーボで係合・解放制御する湿式多板クラッチとされている。また、ブレーキ８も同様にバンドブレーキや噛合い式のブレーキとすることもできるが、本形態では、ハブと変速機ケース１０間に多板の摩擦材を配し、これを油圧サーボで係合・解放制御する湿式多板ブレーキとされている。
【００１９】
この形態では、シンプルプラネタリギヤセットのサンギヤ５１が遊星歯車機構５の第１の入力要素、同じくキャリア５２が第２の入力要素、リングギヤ５３が出力要素とされている。また、変速機１の入・出力軸１１，１２が平行軸配置であることから、出力軸１２上で回転自在なキャリア５２を入力軸１１に駆動連結すべく、平行軸駆動連結機構として歯車機構が用いられており、入力軸１１上に相対回転不能に配設されたドライブギヤ１３に、キャリア５２に同じく相対回転不能に連結されたドリブンギヤ１４をアイドラギヤ１５を介して噛合させた構成とされている。なお、この平行軸駆動連結機構には、入・出力軸２軸の回転方向を合わせるための中間軸配置のアイドラギヤが不要な機構を用いることもできる。こうした機構として、ドライブ・ドリブン側を共にスプリケットとし、これらにチェーンを巻き掛けたチェーン式伝動機構やドライブ・ドリブン側を共にプーリとしてこれらにベルトを巻き掛けたベルト式伝動機構がある。かくして、この変速機では、エンジン２の出力軸に連結される入力軸１１と同軸上に、エンジン側から、ドライブギヤ１３と無段変速機構４のプライマリプーリ４３が配置され、入力軸１１と平行な出力軸１２上に、エンジン側に向かって、無段変速機構４のセカンダリプーリ４４、ドリブンギヤ１４、遊星歯車機構５、ブレーキ８、第１のクラッチ６及び第２のクラッチ７が配列された構成となっている。
【００２０】
次に、前記の構成からなる変速機の作動を説明する。この変速機では、エンジン２が無段変速機構４を経てサンギヤ５１に連結されるとともに、歯車対１３，１４を介してキャリア５２に駆動連結された関係となる。この関係をプラネタリギヤセット５の３要素の回転速度比関係で示すと、図２の速度線図のようになる。すなわち、プラネタリギヤセット５のサンギヤ（Ｓ）５１、キャリア（Ｃ）５２及びリングギヤ（Ｒ）５３を縦軸で表し、各縦軸の上下方向の位置で各要素の速度比（回転数比）を表すものとし、エンジン２の回転を基準の速度比１とし、それに駆動連結関係にあるキャリア（Ｃ）５２の速度比を、両ギヤ１３，１４による増減速がないものとすると、サンギヤ（Ｓ）５１を図の左側にＵターンする矢印で示すように、入力速度比Ａｉの高速（オーバドライブ）回転から入力速度比Ｂｉの低速（アンダドライブ）回転に低下させて行くことで、リングギヤ（Ｒ）５３の速度比は、負速度比Ａｏの逆回転からある程度の増速速度比Ｂｏまで変化する。こうした作動は、無段変速機構４を増速状態から減速状態まで図の右側に上向き矢印で示すように、無段変速させることで生じ、この状態で第２のクラッチ７を係合させておくことで、出力軸１２に逆回転からある程度の増速速度比までの出力速度比を出力させることができる。こうした作用との関係で、第２のクラッチ７は、相対的に低速回転の出力に関与することから、以下の実施形態の説明においてロークラッチと呼ぶ。
【００２１】
そして、前記作動の途中、サンギヤ（Ｓ）５１を等速速度比Ｃｉのところでロークラッチ７を解放し、代わって第１のクラッチ６を係合させると、サンギヤ（Ｓ）５１が出力軸１２につながる入力兼出力要素となる。そこで、今度は無段変速機構４を等速状態から増速状態に戻すように無段変速させることで、サンギヤ（Ｓ）５１の速度比は、等速速度比Ｃｉから高速速度比側に増速され、この回転が出力軸１２の速度比となる。このとき、空転状態のリングギヤ（Ｒ）５３の回転は、等速速度比Ｃｏから図の右側に破線矢印で示すように、減速方向に変化し、サンギヤ（Ｓ）５１の速度比がある特定の高速速度比Ｄｉとなるところで空転が止まる。こうした作用との関係で、第１のクラッチ６は、相対的に高速回転の出力に関与することから、以下の実施形態の説明においてハイクラッチと呼ぶ。
【００２２】
こうしたプラネタリギヤセット５の作動から、ロークラッチ７を係合させた状態では、図３にギヤトレーンの作動を示すように、エンジン２の動力（図に太線矢印で示す）は、歯車対１３，１４を経てキャリア５２に伝達され、プラネタリギヤセット５のリングギヤ５３にトルク増幅されて伝達され、ロークラッチ７を経て車軸につながる出力軸に出力される。このとき、リングギヤ５３にかかる駆動負荷による反力がサンギヤ５１にもトルクを及ぼす。このサンギヤ５１に作用するトルクは、出力軸４２を経て無段変速機構４に戻り、入力軸４１側でエンジン２の出力トルクと合わさって歯車対１３，１４を経て再びキャリア５２に伝達されるトルク循環が生じ、エンジン動力が出力軸に出力されるとともに無段変速機構４と遊星歯車機構５を通って循環するいわゆるトルク循環モードとなる。このモードは、車両発進、低速走行、中速急加速時等の大きな駆動トルクが必要とされるときに選択される。本明細書において、このモードをロー（ｌｏｗ）モードという。
【００２３】
次に、ハイクラッチ６を係合させた状態では、ロークラッチ７の解放によりリングギヤ４３の負荷が解放されることから、図４にギヤトレーンの作動を示すように、エンジン２の動力（図に太線矢印で示す）は、無段変速機構４を経てサンギヤ５１に伝達される経路に替わり、ハイクラッチ６を経て出力軸１２から出力されるトルク伝達モードとなる。このモードは、中速時、高速加速時等のさほど大きな駆動トルクが必要とされないときに選択される。本明細書において、このモードをハイ（ｈｉｇｈ）モードという。
【００２４】
このハイ（ｈｉｇｈ）モードで無段変速機構４の変速比をオーバドライブ方向に偏移させて行くと、速度線図を参照して前記したように、リングギヤ５３の空転速度が下がって行き、やがて速度比０となる。そこで、図５に示すように、ハイクラッチ６係合状態のままブレーキ８を係合させると、リングギヤ５３が変速機ケース１０に係止され、リングギヤ５３を反力要素とするキャリア５２入力サンギヤ５１出力のトルク伝達状態が確立される（本明細書では、この状態をロックアップ（Ｌ−ｕｐ）モードと称する）。このとき、無段変速機構４はトルクを伝達せず、その速度比のまま回転する状態（この状態を図に太破線で示す）となる。理論的には、この状態の無段変速機構４の変速比が保たれれば、無段変速機構４はトルクを伝達せず、伝達ロスを生じないことになるが、実際には、この変速比を保つことは困難である。そこで、本発明に従い、無段変速機構４の軸力を制御するトルク制御により、結果的にこのときの変速比を保つ制御が行われる。
【００２５】
ロックアップモードによるこの後の車両の増速は、エンジン回転数の増加によりなされる。すなわち図２の速度線図を参照して、図に矢印αで示すように、キャリア５２の速度比自体が増加され、これに伴いサンギヤ５１の速度比も増加することで車速が増加する。この際、キャリア５２の速度比とサンギヤ５１の速度比との関係は、線図上でリングギヤ速度比０（図に●印で示す）の点とサンギヤ速度比Ｄｉ（図に◎で示す）の点を通る直線が、リングギヤ速度比０の点を回転中心として図示２点鎖線のように左上がりに持ち上げられる関係にあり、キャリア速度比とサンギヤ速度比間の比率、すなわちキャリアとサンギヤに連結する無段変速機構のプライマリ・セカンダリ両プーリ間の変速比は一定比を保ちながら回転数だけが増加する関係になるから、無段変速機構４の変速比は変わらない。
【００２６】
以上の関係をエンジン回転（すなわちプラネタリギヤセット５のキャリア回転）を基準とし、これを一定（速度比１）としてモードの遷移と各速度比の関係で表すと、図６のようになる。すなわち、変速機をロー（ｌｏｗ）クラッチ係合状態でトルク循環を生じさせるロー（ｌｏｗ）モードでは、無段変速機構４の変速比（ここでは速度比を意味する）を最大値（例えば２．５）の最オーバドライブ（Ｏ／Ｄ）状態から最小値（例えば０．４）の最アンダドライブ（Ｕ／Ｄ）状態まで変化させると、無限変速機の出力は、アンダドライブ（Ｕ／Ｄ）の逆回転状態から０を経て正回転のアンダドライブ（Ｕ／Ｄ）状態、更には速度比１の等速回転まで変化する。ここで、今度は、変速機をハイ（ｈｉｇｈ）クラッチ係合状態で直接トルク出力を生じさせるハイ（ｈｉｇｈ）モードに切換え、無段変速機構４の変速比（ここでは速度比を意味する）を最小値（例えば０．４）の最アンダドライブ（Ｕ／Ｄ）状態から最大値（例えば２．５）の最オーバドライブ（Ｏ／Ｄ）状態まで変化させると、無限変速機の出力は、速度比１の等速回転からオーバドライブ（Ｏ／Ｄ）の高速回転となって行き、やがて空転状態のリングギヤ回転数が０に達する。
【００２７】
この間のプラネタリギヤセット５の各要素の回転は、図に示すように、キャリア回転数比については、エンジン回転数を反映して常時１（図に水平線で示す）、サンギヤ回転数比については、増速回転の回転数比から低下して行き等速度比１を経て再び増速回転の回転数比に上昇（図に矢印βで示す）、リングギヤ回転数比については、負の回転数比から上昇して行き０を経て等速度比１まで達し、その後減少に転じて回転数比０に達する変化となる（図に矢印γで示す）。そして、この間に変速機の出力速度比は、図に右上がりの太線で示すように変化する。この結果、車速は、エンジン回転数一定のままでも後進の低速から最高速まで変化する。
【００２８】
本発明は、このハイモードの最高速付近でリングギヤ回転数比が０となるのを利用して、この時点でロックアップモードとして、リングギヤをブレーキで係合し、キャリアから入力されるエンジントルクの反力をこのリングギヤで受け持たせることで、全てのトルク伝達をプラネタリギヤセット５のみを介するトルク伝達の構造を実現し、歯車式変速機のトルク伝達と同様の伝達効率を達成しようとするものである。この結果無段変速機構の変速比は固定されることになる。ここで理論的には無段変速機構の変速比を目標値とする制御は可能であるが、実際には、冒頭に述べた応答遅れ、制御誤差、機構の組み付け誤差、回転数の計測誤差などの存在により、変速比を目標値とする制御による変速比の固定は困難である。そこで、本発明では、伝達トルクを目標値とする制御によって、リングギヤ固定により決定される無段変速機構の入出力回転数差に応じた変速比が従属的に実現されるようにしている。
【００２９】
この伝達トルクを目標値とする制御は、本形態のように無段変速機構４をベルト式無段変速機構とする場合、プライマリプーリ４３とセカンダリプーリ４４とベルト４５の圧接力によるトルク伝達が０となる制御となる。具体的には、この制御は、両プーリ４３，４４の軸方向可動側部分に同等の軸力を作用させる油圧サーボの油圧を制御することでなされる。
【００３０】
かくして、この第１実施形態の無限変速機によれば、ハイモードの最高速でリングギヤ回転数比が０となるのを利用して、リングギヤを固定し、この時点で全てのトルク伝達をプラネタリギヤセット５のみを介するトルク伝達とすることができるため、無限変速機の最高変速比において、歯車式変速機のトルク伝達と同様の高い伝達効率を達成することができる。
【００３１】
次に示す図７は、本発明の第２実施形態のギヤトレーンを同様のスケルトンで示す。この形態では、前記第１実施形態に対して、必要に応じて無段変速機構４を動力伝達経路から切り離すことで、トルク制御なしでロックアップモードを実現できるように、動力遮断クラッチ９が付加されている。すなわち、この形態では、ブレーキ８による遊星歯車機構５の空転要素５３の回転拘束時に、無段変速機構４を通る動力の伝達を遮断するクラッチ９を備える。このクラッチ９は無段変速機構４の入力軸４１側に設けても、また出力軸４２側に設けても、所期の目的を達成可能であるが、この形態では、変速機１の入力軸１１上と出力軸１２上への各要素の配分を均等化する意味で、入力軸１１上配置としている。すなわち、無段変速機構４の入力軸４１は、遊星歯車機構５の第２の入力要素５２が変速機の入力軸１１に駆動連結する部位より動力伝達経路上の下流で、第３のクラッチ９を介して変速機の入力軸１１に連結された構成が採られている。この第３のクラッチは、その配設目的から明らかなように、第１のクラッチ６の係合による第１の入力要素５１からの出力時における出力要素５３の空転速度が０となるときにブレーキ８の係止と併せて解放制御される。その余の構成は、先の第１実施形態の構成と同様であるので、対応する構成要素に同様の参照符号を付して説明に代える。
【００３２】
この第２実施形態の構成を採ると、第１実施形態に関して先に記した無段変速機構４のトルク制御は不要となるため、無段変速機構４の制御が複雑化しない点で、第１実施形態より有利となる。ただし、機構的には複雑になるため、第１実施形態に対する変速機の大型化は避けられない。
【００３３】
以上、本発明の理解のために実施形態を例示したが、本発明は例示の実施形態に限定されるものではなく、特許請求の範囲に記載の事項の範囲内で、種々に具体的構成を変更して実施可能なものである。例えば、無段変速機構４について、専ら入・出力軸が平行なベルト式無段変速機構を例示したが、これに他の摩擦車伝動式無段変速機構を用いることができ、この場合、入・出力軸が平行なものに限らず、入・出力同軸の摩擦車伝動式無段変速機構を用いることもできる。こうした無段変速機構の代表例として、冒頭に記したトロイダル伝動装置が挙げられる。そして、入・出力同軸の無段変速機構を用いる場合、ＦＲ車用にエンジンを含めた全ての構成要素を１軸配置とする意味では、エンジンに対して無段変速機構、遊星歯車機構を直列に配列するのが有効である。
【００３４】
【発明の効果】
本発明の請求項１に記載の構成によれば、本来無段変速機構を介した伝達効率上不利な動力伝達となるべき最高速度比付近においてブレーキにより遊星歯車機構の出力要素を回転不能に拘束することで、動力伝達を無段変速機構を介する経路から遊星歯車機構を介する経路に切り換えて、無限変速機の伝達効率を歯車式変速機と同様の高い伝達効率とすることができる。したがって、この無限変速機の搭載により車両走行状態を通じて最も使用時間が長いと想定される最高速度比付近の出力状態での伝達効率が改善され、車両走行燃費を向上させることができる。
【００３５】
次に、請求項２に記載の構成によれば、ハイモード時の本来無段変速機構を介した伝達効率上不利な動力伝達となるべき最高速度比付近において、専ら遊星歯車機構を通る動力伝達に切り換えて出力することができるので、無限変速機の伝達効率を歯車式変速機と同様の高い伝達効率とすることができる。したがって、この無限変速機の搭載により車両走行状態を通じて最も使用時間が長いと想定されるハイモード時の最高速度比付近の伝達効率が改善され、車両走行燃費を向上させることができる。
【００３６】
そして、請求項３に記載の構成によれば、無段変速機構の形式を問わず、また、格別無段変速機構の変速比制御形態を変更することなく、前記請求項１又は２に記載の構成により得られる効果を達成する無限変速機を実現することができる。
【００３７】
また、請求項４に記載の構成によれば、最高速度比において、前記請求項１又は２に記載の構成により得られる効果を達成する無限変速機を実現することができる。
【００３８】
そして、請求項５に記載の構成によれば、ブレーキにより遊星歯車機構の出力要素を回転不能に拘束する時期と合せて第３のクラッチを解放作動させることで、無段変速機構の形式を問わず、また、格別無段変速機構の変速比制御形態を変更することなく、前記請求項１又は２に記載の構成により得られる効果を達成する無限変速機を実現することができる。
【００３９】
また、請求項６に記載の構成によれば、変速比の制御に比べてより実効性の高いトルク制御により、無段変速機構が動力を伝達しない状態が確実維持されるため、無限変速機の伝達効率を歯車式変速機と同様の高い伝達効率とする状態をより確実に達成することができる。
【００４０】
また、請求項７に記載の構成によれば、無段変速機構をベルト式無段変速機構として前記各効果を達成することができる。
【００４１】
また、請求項８に記載の構成によれば、無段変速機構をトロイダル式無段変速機構として前記各効果を達成することができる。
【００４２】
また、請求項９に記載の構成によれば、無段変速機構の制御形態を格別変更することなく、前記請求項５記載の構成により得られる効果を達成することができる。
【図面の簡単な説明】
【図１】本発明の適用に係る無限変速機の第１実施形態のギヤトレーンを示すスケルトン図である。
【図２】変速機の遊星歯車機構の作動を示す速度線図である。
【図３】変速機のローモード時の作動説明図である。
【図４】変速機のハイモード時の作動説明図である。
【図５】変速機のロックアップモード時の作動説明図である。
【図６】変速機の作動モードを各部変速比の関係で示すチャートである。
【図７】第２実施形態のギヤトレーンを示すスケルトン図である。
【符号の説明】
１無限変速機
１１変速機の入力軸
１２変速機の出力軸
２エンジン
４ベルト式無段変速機構
４１無段変速機構の入力軸
４２無段変速機構の出力軸
４３プライマリプーリ
４５セカンダリプーリ
４６ベルト
５シンプルプラネタリギヤセット（遊星歯車機構）
５１サンギヤ（第１の入力要素）
５２キャリア（第２の入力要素）
５３リングギヤ（空転要素、出力要素）
６クラッチ
７ブレーキ
８クラッチ
９第３のクラッチ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission, and more particularly to an infinite transmission that performs an infinite shift by a combination of a continuously variable transmission mechanism and a planetary gear mechanism.
[0002]
[Prior art]
As an in-vehicle automatic continuously variable transmission, a mode (low mode) in which a continuously variable transmission mechanism and a planetary gear mechanism are combined to generate torque circulation in the transmission to achieve a state of zero output rotation (gear neutral: GN). A so-called infinitely variable transmission (IVT) that can be switched to a mode (high mode) that directly outputs engine torque via a continuously variable transmission mechanism is known. Such a continuously variable transmission mechanism in IVT is generally controlled with a gear ratio (input / output rotation speed ratio) as a target value. However, it is difficult to obtain the gear neutral state instantaneously and without fluctuation by following the control of the gear ratio. The reason for this includes, for example, the presence of response delay, control error, mechanism assembly error, rotation speed measurement error, and the like.
[0003]
Therefore, conventionally, in IVT using a belt-type continuously variable transmission mechanism as a continuously variable transmission mechanism, control is performed so that the primary and secondary pulley axial forces of the belt-type continuously variable transmission mechanism are equalized so as to self-converge into a gear neutral state. In other words, a technique for controlling a continuously variable transmission mechanism with an output torque instead of a gear ratio as a control target value has been proposed (see Patent Document 1). Similarly, as another technology using a belt-type continuously variable transmission mechanism, a desired creep force is output even in a gear neutral state, as in a conventional planetary gear type automatic transmission using a fluid transmission device as a starting device. There is a technique for controlling the pulley axial force of a belt-type continuously variable transmission mechanism, which is also an example in which output torque is used as a control target value for a continuously variable transmission mechanism (see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-8-261303
[Patent Document 2]
JP-A-10-110802
[0005]
In both the above prior arts, a belt-type transmission mechanism is used as the IVT continuously variable transmission mechanism, but other continuously variable transmission mechanisms such as a toroidal system can also be used. As an example of an infinite transmission using a toroidal-type continuously variable transmission mechanism, for example, there is the following technique (see Non-Patent Document 1). Regarding the mechanism of IVT, the following document is detailed (see Non-Patent Document 2).
[0006]
[Non-Patent Document 1]
“KOYO Engineering Journal”, no. 161, p. 18-25
[Non-Patent Document 2]
“KOYO Engineering Journal”, no. 160
[0007]
[Problems to be solved by the invention]
In general, a vehicle equipped with a continuously variable transmission has an efficient point (the number of revolutions) for an engine (which means a combustion engine such as an internal combustion engine or an external combustion engine in this specification) due to the effect of continuously variable transmission with respect to a required output. , Torque), and as a result, high fuel consumption can be expected. However, the transmission efficiency of the continuously variable transmission mechanism itself is not very good. When traveling at a maximum overdrive state (meaning the gear ratio that maximizes the speed ratio) such as during high-speed driving, the transmission efficiency is high. Therefore, the fuel efficiency is inferior to that of a vehicle equipped with a geared multi-stage transmission with good transmission efficiency. This is the same in the case of IVT using a continuously variable transmission mechanism, and the fuel efficiency during high-speed traveling is inferior to that of a geared multi-stage transmission.
[0008]
Therefore, in order to solve the above-described problems, the present invention can eliminate the torque transmission through the continuously variable transmission mechanism in a state where the continuously variable transmission mechanism transmits power near the most overdrive, and the infinite transmission. It is an object of the present invention to provide an infinite transmission capable of improving the transmission efficiency of the transmission and contributing to the improvement of the driving fuel consumption of a vehicle equipped with a transmission.
Also, in the state where the continuously variable transmission mechanism transmits power in the vicinity of the most overdrive, the transmission efficiency of the infinite transmission is improved by eliminating torque transmission via the continuously variable transmission mechanism, and the driving fuel consumption of the vehicle equipped with the transmission is improved. Another object is to provide an infinite transmission that contributes to improvement.
[0009]
[Means for Solving the Problems]
The above-described object is to provide, as a basic structure, an input shaft of an infinite transmission connected to the engine, an output shaft of the infinite transmission, at least first and second input elements and one output element. A planetary gear mechanism provided; a first clutch that engages and disengages the first input element and an output shaft of the infinite transmission; and an engagement and disengagement of the output element and the output shaft of the infinite transmission. A second clutch; a brake that restrains the output element to be unrotatable; and a continuously variable transmission mechanism that performs a continuously variable transmission; and an input shaft of the continuously variable transmission mechanism includes an input shaft of the infinite transmission This is achieved by a configuration in which the second input element is connected to the second input element and the output shaft of the continuously variable transmission mechanism is connected to the first input element.
In the above configuration, it is also effective to adopt a configuration in which the second clutch cuts off transmission of power through the continuously variable transmission mechanism when the brake restrains the output element so as not to rotate.
[0010]
And in the said structure, the input shaft of the said continuously variable transmission mechanism is a 3rd clutch downstream from the site | part where the input shaft of an infinite transmission and the said 2nd input element are drive-connected on a power transmission path | route. It is also effective to adopt a configuration that is connected to the input shaft of the infinite transmission via the.
In this case, when the third clutch outputs from the first input element due to the engagement of the first clutch, the idling speed of the output element becomes 0 according to the speed ratio of the first input element. Sometimes released.
[0011]
In the above configuration, when the brake is output from the first input element due to engagement of the first clutch, the idling speed of the output element becomes 0 according to the speed ratio of the first input element. Sometimes locked to restrain the output element from rotating. In this case, control is performed so that torque transmission in the continuously variable transmission mechanism becomes zero in a state where the brake is locked and the output element is restrained so as not to rotate.
Specifically, when the continuously variable transmission mechanism is a belt type continuously variable transmission mechanism in which a belt is wound between a primary pulley and a secondary pulley and torque is transmitted according to the pressure contact force between each pulley and the belt. The control for torque transmission to be zero is performed by adjusting the pressure contact force.
In the case where the continuously variable transmission mechanism is a toroidal continuously variable transmission mechanism that includes a roller sandwiched between an input disk and an output disk and transmits torque by adjusting the position of the roller, The control to be zero is performed by eliminating the driving force for adjusting the position of the roller.
[0012]
[Action]
In the configuration described in claim 1 of the present invention, in the output state by the engagement of the second clutch, the power input to the infinite transmission is input from the second input element to the planetary gear mechanism, and the output element To the output shaft through the second clutch and the reaction force received by the first input element is also transmitted to the continuously variable transmission mechanism, thereby generating torque circulation through the planetary gear mechanism and the continuously variable transmission mechanism. . In this state, by changing the gear ratio of the continuously variable transmission mechanism, an output of a speed increase speed ratio from a reverse rotation output to a certain degree of forward rotation through a zero gear neutral is made. Further, in the output state due to the engagement of the first clutch, the planetary gear mechanism does not transmit power due to idling of the output element, so that the power input to the infinite transmission passes exclusively through the continuously variable transmission mechanism. It passes through the first input element and is output to the output shaft via the first clutch. When the gear ratio of the continuously variable transmission mechanism is increased in this state, the idling speed ratio of the output element of the planetary gear mechanism that has continued to decrease near the maximum output speed ratio approaches zero. At this time, by engaging the brake, the output element acts as a reaction force element, and thereafter the power is exclusively planetary gear by keeping the speed ratio of the continuously variable transmission mechanism at the speed ratio at the time of brake engagement. A state of being output via the first clutch through the mechanism continues.
[0013]
Next, in the configuration according to claim 2, in the low mode by switching the clutch, the power input to the infinite transmission is output via the planetary gear mechanism and also transmitted to the continuously variable transmission mechanism. This causes torque circulation through the planetary gear mechanism and the continuously variable transmission mechanism. In this state, by changing the speed ratio of the continuously variable transmission mechanism, the speed increasing speed ratio is output from the reverse rotation output through the gear neutral of 0 rotation to a certain degree of forward rotation. In the high mode, the power is output exclusively through the continuously variable transmission mechanism. When the speed ratio of the continuously variable transmission mechanism is increased in this state, an operation is performed in which the speed ratio of the idling element of the planetary gear mechanism that has continued to decrease reaches zero near the maximum output speed ratio. At this time, by engaging the brake, the idling element acts as a reaction force element. After that, by maintaining the speed ratio of the continuously variable transmission mechanism at the speed ratio at this time, power is exclusively transmitted through the planetary gear mechanism. The state output by continues.
In the configuration described in claim 3, the power transmission through the continuously variable transmission mechanism is mechanically interrupted.
According to the fifth aspect of the present invention, power transmission through the continuously variable transmission mechanism is interrupted by releasing the third clutch.
[0014]
Furthermore, in the configuration of the fourth aspect, the brake engagement timing is made to coincide with the timing when the idling speed ratio of the output element of the planetary gear mechanism becomes zero in the vicinity of the maximum speed ratio of the output. Is easily performed. Then, the output element that has been idling by the engagement of the brake acts as a reaction force element. Therefore, by maintaining the gear ratio of the continuously variable transmission mechanism at this time, the power continues to be output through the first clutch through the planetary gear mechanism.
In the configuration described in claim 6, the output state by the power transmission of only the planetary gear mechanism is reliably continued by positively maintaining the speed ratio.
According to the seventh aspect of the present invention, the continuously variable transmission mechanism is a belt-type continuously variable transmission mechanism, and the above-described action occurs by adjusting the pressure contact force between the pulley and the belt.
Further, in the configuration according to the eighth aspect, the continuously variable transmission mechanism is a toroidal continuously variable transmission mechanism, and the above-described action occurs by eliminating the driving force for adjusting the roller position.
According to the ninth aspect of the present invention, the operation in which the idling speed ratio of the output element of the planetary gear mechanism becomes 0 when the brake engagement timing and the third clutch release timing are in the vicinity of the maximum output speed ratio. And the power transmission through the continuously variable transmission mechanism is interrupted regardless of the transmission gear ratio, and the power continues to be output through the first clutch through the planetary gear mechanism.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows the structure of 1st Embodiment of the infinite transmission based on application of this invention with a skeleton. This infinite transmission 1 is composed of a combination of a continuously variable transmission mechanism 4, a planetary gear mechanism 5, and clutches 6 and 7 for switching the power transmission path, and the input power is transmitted to the continuously variable transmission mechanism 4 and the planetary gear mechanism. And an infinite transmission that achieves an infinite shift by a low mode that outputs while generating torque circulation by power transmission through 5 and a high mode that outputs by power transmission through the continuously variable transmission mechanism 4. According to the characteristics, a brake 8 that restricts the rotation of the idling element 53 of the planetary gear mechanism 5 is provided near the maximum speed ratio in the high mode, and the power transmission path is switched to power transmission through the planetary gear mechanism 5 by the locking of the brake 8. It causes the operation.
[0016]
Specifically, the transmission 1 includes three elements: an input shaft 11 coupled to the engine 2, a continuously variable transmission mechanism 4, first and second input elements 51 and 52, and one output element 53. , A first clutch 6 that engages and disengages the first input element 51 of the planetary gear mechanism 5 with the output shaft 12 of the transmission 1, and the output element 53 as the output shaft of the transmission 1. The continuously variable transmission mechanism 4 has an input shaft 41 connected to the input shaft 11 of the transmission 1 and a second input element 52 of the planetary gear mechanism 5. The output shaft 42 is connected to the first input element 51, and the brake 8 that restrains the output element 53 of the planetary gear mechanism 5 so as not to rotate is provided.
[0017]
The brake 8 is locked when the idling speed of the output element 53 at the time of output from the first input element 51 due to the engagement of the first clutch 6 becomes 0, and the output element 53 cannot be rotated. Controlled to restrain. In contrast, the continuously variable transmission mechanism 4 is capable of transmitting torque from the input shaft 41 to the output shaft 42 of the continuously variable transmission mechanism 4 when the output element 53 of the planetary gear mechanism 5 is not allowed to rotate due to the brake 8 being locked. It is controlled to be zero.
[0018]
More specifically, in the transmission 1, the input shaft 11 can be connected to the engine 2 via a drive plate (not shown), and an output shaft 12 parallel to the input shaft 11 is connected to a differential device and a universal joint. Via the axle. The continuously variable transmission mechanism 4 includes a primary pulley 43 disposed on the input shaft 11 side and a secondary pulley 44 disposed on the output shaft 42 side in order to transmit power between the parallel shaft, that is, the input shaft 41 and the output shaft 42. The belt 45 is wound between the two belts, and the width of the winding portion with respect to each pulley is controlled so that a continuously variable transmission is possible. The planetary gear mechanism 5 is a simple planetary gear set including a sun gear 51, a carrier 52 that rotatably supports a plurality of pinion gears externally meshed with the sun gear 51, and a ring gear 53 that meshes internally with the pinion gears. The type of the first clutch 6 and the second clutch 7 is not particularly limited, but in this embodiment, a multi-plate friction material is arranged between the hub and the drum, and these are engaged by a hydraulic servo. -It is a wet multi-plate clutch that controls release. Similarly, the brake 8 can be a band brake or a mesh type brake. In this embodiment, a multi-plate friction material is disposed between the hub and the transmission case 10 and is engaged by a hydraulic servo.・ It is a wet multi-plate brake with release control.
[0019]
In this embodiment, the sun gear 51 of the simple planetary gear set is the first input element of the planetary gear mechanism 5, the carrier 52 is the second input element, and the ring gear 53 is the output element. In addition, since the input / output shafts 11 and 12 of the transmission 1 are arranged in parallel shafts, a gear mechanism is used as a parallel shaft drive coupling mechanism for drivingly coupling the carrier 52 rotatable on the output shaft 12 to the input shaft 11. The drive gear 13 disposed on the input shaft 11 so as not to rotate relatively is engaged with the driven gear 14 connected to the carrier 52 so as not to rotate relative thereto via the idler gear 15. Yes. As the parallel shaft drive coupling mechanism, a mechanism that does not require an idler gear having an intermediate shaft arrangement for matching the rotational directions of the two input / output shafts can be used. As such a mechanism, there are a chain-type transmission mechanism in which the drive-driven side is both a sprocket and a chain is wound around them, and a belt-type transmission mechanism in which the drive-driven side is both a pulley and a belt is wound around them. Thus, in this transmission, the drive gear 13 and the primary pulley 43 of the continuously variable transmission mechanism 4 are arranged on the same axis as the input shaft 11 connected to the output shaft of the engine 2 from the engine side, and are parallel to the input shaft 11. A configuration in which the secondary pulley 44, the driven gear 14, the planetary gear mechanism 5, the brake 8, the first clutch 6, and the second clutch 7 of the continuously variable transmission mechanism 4 are arranged on the output shaft 12 toward the engine side. It has become.
[0020]
Next, the operation of the transmission configured as described above will be described. In this transmission, the engine 2 is connected to the sun gear 51 via the continuously variable transmission mechanism 4 and is connected to the carrier 52 via the gear pairs 13 and 14. If this relationship is represented by the relationship between the rotational speed ratios of the three elements of the planetary gear set 5, the speed diagram of FIG. 2 is obtained. That is, the sun gear (S) 51, the carrier (C) 52, and the ring gear (R) 53 of the planetary gear set 5 are represented by vertical axes, and the speed ratio (rotational speed ratio) of each element is represented by the vertical position of each vertical axis. Assuming that the rotation speed of the engine 2 is a reference speed ratio 1 and the speed ratio of the carrier (C) 52 in the drive connection relation is not increased or decreased by the two gears 13 and 14, the sun gear (S) 51 Is reduced from a high speed (overdrive) rotation with an input speed ratio Ai to a low speed (underdrive) rotation with an input speed ratio Bi, as indicated by an arrow that makes a U-turn on the left side of the figure. The speed ratio changes from the reverse rotation of the negative speed ratio Ao to a certain acceleration speed ratio Bo. Such an operation is caused by continuously shifting the continuously variable transmission mechanism 4 from the speed increasing state to the deceleration state as indicated by an upward arrow on the right side of the drawing, and the second clutch 7 is engaged in this state. Thus, the output speed ratio from the reverse rotation to a certain speed increase speed ratio can be output to the output shaft 12. In relation to such an action, the second clutch 7 is relatively involved in the output of the low-speed rotation, and is therefore referred to as a low clutch in the following description of the embodiment.
[0021]
During the operation, when the sun gear (S) 51 is released at the constant speed ratio Ci and the low clutch 7 is released and the first clutch 6 is engaged instead, the sun gear (S) 51 is connected to the output shaft 12. Connected and output element. Therefore, the speed ratio of the sun gear (S) 51 is increased from the constant speed ratio Ci to the high speed ratio by continuously changing the continuously variable transmission mechanism 4 so as to return from the constant speed state to the increased speed state. This rotation is the speed ratio of the output shaft 12. At this time, the rotation of the ring gear (R) 53 in the idling state changes from the constant speed ratio Co to the decelerating direction as indicated by a broken line arrow on the right side of the drawing, and the speed ratio of the sun gear (S) 51 is a specific speed ratio. The idling stops at the high speed ratio Di. In relation to such an action, the first clutch 6 is relatively involved in the output of high-speed rotation, and is therefore referred to as a high clutch in the following description of the embodiments.
[0022]
From the operation of the planetary gear set 5, when the low clutch 7 is engaged, the power of the engine 2 (indicated by the bold arrows in the figure) is applied to the gear pairs 13 and 14 as shown in FIG. The torque is amplified and transmitted to the ring gear 53 of the planetary gear set 5 via the low clutch 7 and output to the output shaft connected to the axle. At this time, the reaction force due to the driving load applied to the ring gear 53 also exerts torque on the sun gear 51. The torque acting on the sun gear 51 returns to the continuously variable transmission mechanism 4 via the output shaft 42, and is combined with the output torque of the engine 2 on the input shaft 41 side and transmitted again to the carrier 52 via the gear pairs 13 and 14. Circulation occurs, and the engine power is output to the output shaft and a so-called torque circulation mode in which the engine power is circulated through the continuously variable transmission mechanism 4 and the planetary gear mechanism 5 is obtained. This mode is selected when a large driving torque is required, such as when starting a vehicle, traveling at a low speed, or during a medium-speed rapid acceleration. In this specification, this mode is referred to as a low mode.
[0023]
Next, when the high clutch 6 is engaged, the load of the ring gear 43 is released by releasing the low clutch 7, so that the power of the engine 2 (thick line in the figure) is shown in FIG. (Indicated by an arrow) is a torque transmission mode that is output from the output shaft 12 via the high clutch 6 instead of the path that is transmitted to the sun gear 51 via the continuously variable transmission mechanism 4. This mode is selected when a large driving torque is not required, such as during medium speed and high speed acceleration. In this specification, this mode is referred to as a high mode.
[0024]
When the gear ratio of the continuously variable transmission mechanism 4 is shifted in the overdrive direction in this high mode, the idling speed of the ring gear 53 decreases as described above with reference to the speed diagram, and eventually. The speed ratio is zero. Therefore, as shown in FIG. 5, when the brake 8 is engaged with the high clutch 6 engaged, the ring gear 53 is locked to the transmission case 10, and the carrier 52 input sun gear 51 having the ring gear 53 as a reaction force element. An output torque transmission state is established (in this specification, this state is referred to as a lock-up (L-up) mode). At this time, the continuously variable transmission mechanism 4 does not transmit torque and rotates in its speed ratio (this state is indicated by a thick broken line in the figure). Theoretically, if the gear ratio of the continuously variable transmission mechanism 4 in this state is maintained, the continuously variable transmission mechanism 4 does not transmit torque and causes no transmission loss. It is difficult to keep the ratio. Therefore, according to the present invention, the torque control for controlling the axial force of the continuously variable transmission mechanism 4 is performed to control the gear ratio at this time.
[0025]
The subsequent vehicle speed increase in the lock-up mode is performed by increasing the engine speed. That is, referring to the speed diagram of FIG. 2, as indicated by an arrow α in the figure, the speed ratio of the carrier 52 itself is increased, and the speed ratio of the sun gear 51 is also increased accordingly, thereby increasing the vehicle speed. At this time, the relationship between the speed ratio of the carrier 52 and the speed ratio of the sun gear 51 is as follows: the ring gear speed ratio 0 (indicated by ● in the figure) and the sun gear speed ratio Di (indicated by ◎ in the figure) on the diagram. The straight line passing through the point is lifted to the left as shown by the two-dot chain line in the figure with the ring gear speed ratio 0 as the center of rotation, and is connected to the ratio between the carrier speed ratio and the sun gear speed ratio, that is, the carrier and the sun gear. Since the gear ratio between the primary and secondary pulleys of the continuously variable transmission mechanism is a relationship in which only the rotational speed increases while maintaining a constant ratio, the gear ratio of the continuously variable transmission mechanism 4 does not change.
[0026]
When the above relationship is based on the engine rotation (that is, the carrier rotation of the planetary gear set 5) as a reference and this is constant (speed ratio 1), the relationship between the mode transition and each speed ratio is as shown in FIG. That is, in the low mode in which torque circulation is generated with the transmission engaged with a low clutch, the speed ratio of the continuously variable transmission mechanism 4 (which means a speed ratio here) is set to a maximum value (for example, 2. 5) When changing from the most overdrive (O / D) state of 5) to the minimum underdrive (U / D) state of the minimum value (for example, 0.4), the output of the infinite transmission is underdrive (U / D). The reverse rotation state changes from 0 to a forward rotation underdrive (U / D) state, and further to a constant speed rotation with a speed ratio of 1. Here, this time, the transmission is switched to a high mode that directly generates a torque output in a high clutch engaged state, and the gear ratio of the continuously variable transmission mechanism 4 (which means a speed ratio here) is changed. When changing from a minimum underdrive (U / D) state with a minimum value (eg 0.4) to a maximum overdrive (O / D) state with a maximum value (eg 2.5), the output of the infinite transmission is The speed of the overdrive (O / D) increases from a constant speed rotation of a ratio of 1, and the ring gear rotation speed in an idle state eventually reaches zero.
[0027]
As shown in the figure, the rotation of each element of the planetary gear set 5 during this period is always 1 (indicated by a horizontal line in the figure) for the engine speed ratio, and increased for the sun gear speed ratio. Decreases from the speed ratio of the high speed rotation and goes up to the speed ratio of the speed increasing speed again through the constant speed ratio 1 (indicated by arrow β in the figure), and the ring gear speed ratio increases from the negative speed ratio Then, after going through 0, the speed reaches a constant speed ratio of 1, and then starts to decrease and reaches a rotational speed ratio of 0 (indicated by an arrow γ in the figure). During this time, the output speed ratio of the transmission changes as shown by a bold line rising to the right in the figure. As a result, the vehicle speed changes from the reverse speed to the maximum speed even when the engine speed remains constant.
[0028]
The present invention utilizes the fact that the ring gear rotation speed ratio becomes 0 near the maximum speed in the high mode, and at this time, as a lock-up mode, the ring gear is engaged with a brake and the engine torque input from the carrier is reduced. By providing the reaction force with this ring gear, it is possible to achieve a torque transmission structure in which all torque transmission is via the planetary gear set 5 only, and to achieve the same transmission efficiency as that of the gear transmission. is there. As a result, the transmission ratio of the continuously variable transmission mechanism is fixed. Theoretically, control with the gear ratio of the continuously variable transmission mechanism as the target value is possible, but in reality, the response delay, control error, mechanism assembly error, rotational speed measurement error, etc. described at the beginning Therefore, it is difficult to fix the gear ratio by control with the gear ratio as a target value. Therefore, in the present invention, a gear ratio according to the input / output rotational speed difference of the continuously variable transmission mechanism determined by fixing the ring gear is dependently realized by control using the transmission torque as a target value.
[0029]
When the continuously variable transmission mechanism 4 is a belt-type continuously variable transmission mechanism as in the present embodiment, the control with this transmission torque as a target value is zero torque transmission due to the pressure contact force of the primary pulley 43, the secondary pulley 44, and the belt 45. It becomes the control which becomes. Specifically, this control is performed by controlling the hydraulic pressure of a hydraulic servo that applies an equivalent axial force to the axially movable side portions of both pulleys 43 and 44.
[0030]
Thus, according to the infinite transmission of the first embodiment, the ring gear is fixed by utilizing the fact that the ring gear rotational speed ratio becomes 0 at the highest speed in the high mode, and at this point all torque transmission is transmitted to the planetary gear set. Therefore, it is possible to achieve high transmission efficiency similar to the torque transmission of the gear type transmission at the maximum gear ratio of the infinite transmission.
[0031]
Next, FIG. 7 shows the gear train of 2nd Embodiment of this invention with the same skeleton. In this embodiment, a power cut-off clutch 9 is added to the first embodiment so that the lockup mode can be realized without torque control by separating the continuously variable transmission mechanism 4 from the power transmission path as necessary. Has been. That is, in this embodiment, the clutch 9 is provided that interrupts transmission of power through the continuously variable transmission mechanism 4 when the idling element 53 of the planetary gear mechanism 5 is restrained from rotating by the brake 8. Although the clutch 9 can be provided on the input shaft 41 side or the output shaft 42 side of the continuously variable transmission mechanism 4, the intended purpose can be achieved. In this embodiment, the input shaft of the transmission 1 can be achieved. 11 is arranged on the input shaft 11 in order to equalize the distribution of each element on the output shaft 12. In other words, the input shaft 41 of the continuously variable transmission mechanism 4 is connected to the third clutch 9 downstream of the portion where the second input element 52 of the planetary gear mechanism 5 is drivingly connected to the input shaft 11 of the transmission on the power transmission path. The structure connected with the input shaft 11 of the transmission via is taken. This third clutch is braked when the idling speed of the output element 53 becomes zero when the first input element 51 is output due to the engagement of the first clutch 6, as is apparent from the installation purpose. The release control is performed together with the locking of 8. Since the remaining configuration is the same as the configuration of the first embodiment, the same reference numerals are assigned to the corresponding components, and the description is omitted.
[0032]
When the configuration of the second embodiment is adopted, the torque control of the continuously variable transmission mechanism 4 described above with respect to the first embodiment is unnecessary, and therefore the first control is not complicated in the control of the continuously variable transmission mechanism 4. It is more advantageous than the embodiment. However, since the mechanism is complicated, an increase in the size of the transmission relative to the first embodiment is inevitable.
[0033]
The embodiments have been described above for the understanding of the present invention. However, the present invention is not limited to the illustrated embodiments, and various specific configurations may be made within the scope of the matters described in the claims. It can be changed and implemented. For example, the continuously variable transmission mechanism 4 is exemplified by a belt type continuously variable transmission mechanism whose input and output shafts are parallel to each other, but another friction vehicle transmission type continuously variable transmission mechanism can be used for this. -The output shaft is not limited to being parallel, and an input / output coaxial friction wheel transmission type continuously variable transmission mechanism can also be used. A typical example of such a continuously variable transmission mechanism is the toroidal transmission device described at the beginning. When an input / output coaxial continuously variable transmission mechanism is used, a continuously variable transmission mechanism and a planetary gear mechanism are connected in series to the engine in the sense that all components including the engine for an FR vehicle are arranged in a single axis. It is effective to arrange in
[0034]
【The invention's effect】
According to the configuration of the first aspect of the present invention, the output element of the planetary gear mechanism is restrained to be non-rotatable by the brake in the vicinity of the maximum speed ratio that should be an unfavorable power transmission through the continuously variable transmission mechanism. By doing so, the power transmission can be switched from the path via the continuously variable transmission mechanism to the path via the planetary gear mechanism, and the transmission efficiency of the infinite transmission can be made as high as that of the gear transmission. Therefore, the installation of the infinite transmission improves the transmission efficiency in the output state near the maximum speed ratio, which is assumed to be the longest use time throughout the vehicle travel state, and can improve the vehicle travel fuel consumption.
[0035]
Next, according to the second aspect of the present invention, the power transmission through the planetary gear mechanism exclusively in the vicinity of the maximum speed ratio that should be a disadvantageous power transmission through the continuously variable transmission mechanism in the high mode. Therefore, the transmission efficiency of the infinite transmission can be set to the same high transmission efficiency as that of the gear type transmission. Therefore, by installing this infinite transmission, the transmission efficiency near the maximum speed ratio in the high mode, which is assumed to be the longest use time throughout the vehicle running state, is improved, and the vehicle running fuel consumption can be improved.
[0036]
And according to the structure of Claim 3, irrespective of the form of a continuously variable transmission mechanism, and without changing the gear ratio control form of a special continuously variable transmission mechanism, the said Claim 1 or 2 is described. An infinite transmission that achieves the effects obtained by the configuration can be realized.
[0037]
Moreover, according to the structure of Claim 4, in the maximum speed ratio, the infinite transmission which achieves the effect acquired by the structure of the said Claim 1 or 2 is realizable.
[0038]
According to the fifth aspect of the present invention, the third clutch is disengaged at the timing when the output element of the planetary gear mechanism is unrotatably restrained by the brake, so that the type of continuously variable transmission mechanism can be determined. In addition, it is possible to realize an infinite transmission that achieves the effect obtained by the configuration according to claim 1 or 2 without changing the speed ratio control mode of the special continuously variable transmission mechanism.
[0039]
Further, according to the configuration of the sixth aspect, since the continuously variable transmission mechanism is reliably maintained in a state where no power is transmitted by the torque control that is more effective than the speed ratio control, the infinite transmission A state in which the transmission efficiency is set to the same high transmission efficiency as that of the gear transmission can be achieved more reliably.
[0040]
Moreover, according to the structure of Claim 7, each said effect can be achieved by making a continuously variable transmission mechanism into a belt-type continuously variable transmission mechanism.
[0041]
Moreover, according to the structure of Claim 8, each said effect can be achieved by making a continuously variable transmission mechanism into a toroidal type continuously variable transmission mechanism.
[0042]
Moreover, according to the structure of Claim 9, the effect acquired by the structure of the said Claim 5 can be achieved, without changing the control form of a continuously variable transmission mechanism exceptionally.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing a gear train of a first embodiment of an infinite transmission according to an application of the present invention.
FIG. 2 is a velocity diagram showing the operation of the planetary gear mechanism of the transmission.
FIG. 3 is an operation explanatory diagram of a transmission in a low mode.
FIG. 4 is an operation explanatory diagram of a transmission in a high mode.
FIG. 5 is an operation explanatory diagram of a transmission in a lock-up mode.
FIG. 6 is a chart showing the operation mode of the transmission in relation to the gear ratio of each part.
FIG. 7 is a skeleton diagram showing a gear train of a second embodiment.
[Explanation of symbols]
1 Infinite transmission
11 Transmission input shaft
12 Output shaft of transmission
2 Engine
4 Belt type continuously variable transmission mechanism
41 Input shaft of continuously variable transmission
42 Output shaft of continuously variable transmission
43 Primary pulley
45 Secondary pulley
46 belt
5 Simple planetary gear set (Planetary gear mechanism)
51 Sun gear (first input element)
52 Carrier (second input element)
53 Ring gear (idling element, output element)
6 Clutch
7 Brake
8 Clutch
9 Third clutch

Claims

An input shaft of the infinitely variable transmission connected with the engine, an output shaft of the infinitely variable transmission, a planetary gear mechanism having three elements of at least first, second two input elements and one output element a first clutch for engaging and disengaging coupling and the output shaft of the infinitely variable transmission and the first input element, and a second clutch disengaging coupling the output shaft of the infinitely variable transmission and the output element, a brake for rotatably restraining the output element, which has a continuously variable transmission mechanism for stepless, together with the input shaft of the continuously variable transmission mechanism is connected to the input shaft of the infinitely variable transmission, the drivingly connected to the second input element, an output shaft of the continuously variable transmission mechanism is infinitely variable transmission, characterized in that that will be connected to the first input element.

A low mode that outputs input power while generating torque circulation by power transmission through the continuously variable transmission mechanism and the planetary gear mechanism, and a high mode that outputs input power by power transmission through the continuously variable transmission mechanism The brake is locked near the maximum speed ratio of the output in the high mode, restrains the output element to be non-rotatable, and moves the power transmission path through the continuously variable transmission mechanism. The infinite transmission according to claim 1, wherein the transmission path is switched to a power transmission path that passes through the planetary gear mechanism.

The infinite transmission according to claim 1 or 2, wherein when the brake restrains the output element to be non-rotatable, the second clutch interrupts transmission of power through the continuously variable transmission mechanism.

The brake causes the locking when Oite when the output from the first input element by the engagement of the first clutch, idling speed of the output element in accordance with the speed ratio of the input element of first becomes 0 is, the infinite transmission according to 請 Motomeko 1 it unrotatably restraining the output element.

The input shaft of the continuously variable transmission mechanism, in the power transmission path, downstream from the site where the input shaft of the infinitely variable transmission and the second input element is drivingly connected, via a third clutch, the endless transmission according to claim 1 or 4 and the input shaft of the infinitely variable transmission Ru is connected.

In the state where the brake is locked and the output element is restrained to be non-rotatable , the transmission torque is set as a target value, and the input / output rotational speed difference of the continuously variable transmission mechanism is determined by fixing the output element. based on the response speed ratio, infinite transmission according to claim 1 or 4 controlled so that the torque transmission in the continuously variable transmission mechanism is 0 is performed.

The continuously variable transmission mechanism is a belt type continuously variable transmission mechanism that wraps a belt between a primary pulley and a secondary pulley and transmits torque according to the pressure contact force between each pulley and the belt. comprising control infinite transmission according to claim 6 which is carried out by adjusting the contact pressure.

The continuously variable transmission mechanism is a toroidal continuously variable transmission mechanism that includes a roller sandwiched between an input disk and an output disk, and transmits torque by adjusting the position of the roller. control, infinite transmission according to claim 6 which is performed by the eliminating the driving force for the adjustment of the position of the roller.

It said third clutch, when Oite when the output from the first input element by the engagement of the first clutch, idling speed of the output element in accordance with the speed ratio of the input element of first becomes 0 infinite transmission according to claim 5 to be released.