JP3557641B2 - Hydraulic control device for automatic transmission - Google Patents

Description

【００２８】
表１から明らかなように、１速と２速との間の変速時には、ローリバースブレーキ27と２−４ブレーキ26とが変速に関与し、２速と３速との間の変速時には、２−４ブレーキ26と３−４クラッチ24とが変速に関与し、３速と４速との間の変速時には、２−４ブレーキ26とフォワードクラッチ21とが変速に関与して、それぞれ一方が解放され、他方が締結されるようになっている。すなわち、１速ではローリバースブレーキ27が締結されて、２−４ブレーキ26が解放され、２速では、２−４ブレーキ26が締結され、３−４クラッチ24が解放されているが、３速への変速時に、２−４ブレーキ26が解放され、３−４クラッチ24が締結される。また、３速では、２−４ブレーキ26が解放され、フォワードクラッチ21が締結されているが、４速への変速時に、２−４ブレーキ26が締結され、フォワードクラッチ21が解放される。
【００２９】
さらに、同時に締結されると動力伝達経路がインタロックする関係にある摩擦締結要素を表２に示す。
【００３０】
【表２】

【００３１】
表２から明らかなように、ローリバースブレーキ27と２−４ブレーキ26とが同時に締結されたとき、およびローリバースブレーキ27と３−４クラッチ24とが同時に締結されたとき、それぞれ動力伝達経路がインタロックするから、図２の油圧回路は、このインタロックのが発生を阻止する構成となっている。
【００３２】
次に、図２に示す各摩擦締結要素の締結室および解放室に対して作動油を給排する各種弁の構成および動作について詳細に説明する。
【００３３】
オイルポンプ７で昇圧された作動油は、油路ａを経てプレッシャレギュレータバルブ23に供給される。このプレッシャレギュレータバルブ23を制御するために、二方デューティソレノイド弁28（符号Ｃでしめされている）とモデュレータバルブ29とが設けられており、ソレノイド弁28は、エンジントルクに応じた（通常はスロットル開度に応じた）パイロット圧を出力し、モデュレータバルブ29を介して、プレッシャレギュレータバルブ23の出力圧（ライン圧）をエンジントルクに応じて調圧するように構成されている。そして、このようにして得られたライン圧は、油路ｂを経てマニュアルバルブ30に供給される。
【００３４】
マニュアルバルブ30は、図面を簡単にするために、ＤレンジとＲレンジとを切換える２ポート２位置切換弁として描かれており、Ｎレンジその他は省略されている。そして、マニュアルバルブ30に供給されたライン圧は、シフトレバーの位置により、２つの油路ｃ，ｄのうちの１方に選択的に伝達される。すなわち、Ｄレンジではライン圧が油路ｃに伝達され、Ｒレンジでは油路ｄに伝達されるとともに、油路ｃ，ｄのうちのいずれかが選択されてこれにライン圧が伝達されたとき、他方の油路内の作動油はドレーンされるように構成されている。
【００３５】
一方、ローリバースブレーキ27と２−４ブレーキ26とが同時に締結されるのを防止するために、ローリバースブレーキ27の解放室27Ｒと２−４ブレーキ26の締結室26Ａとが油路ｅを介して連通され、この油路ｅと油路ｃと間に、ドレーンポートを備えた常開型の三方デューティソレノイド弁31（符号Ａで示されている）と、切換弁33とが油路ｆを挟んで介装されている。
【００３６】
上記三方デューティソレノイド弁31は、１速と２速との間の変速に際して、ローリバースブレーキ27の解放室27Ｒと２−４ブレーキ26の締結室26Ａとに対し供給・排出される作動油の油圧のデューティ制御して、ローリバースブレーキ27および２−４ブレーキ26のトルク容量をコントロールするためと、３速および４速において、差圧制御弁32を介したロックアップクラッチ14のスリップ制御とを行うために設けられているソレノイド弁である。また、上記切換弁33は、スプリングオフセット・パイロット方式の５ポート２位置切換弁よりなり、３速および４速で締結される３−４クラッチ24の締結室24Ａに連通する油路ｇ内の油圧が、切換弁33に対しパイロット圧として作用するようになっている。
【００３７】
すなわち、表１から明らかなように、１速および２速では、３−４クラッチ24の締結室24Ａ内の作動油が後述する経路で排出されることにより、上記切換弁33に対してはパイロット圧が作用せず、したがって、切換弁33はオフセットスプリングの付勢力で、図２に示す第１の切換位置にあり、三方デューティソレノイド弁31の下流側の油路ｆが、切換弁33および油路ｅを介してローリバースブレーキ27の解放室27Ｒと２−４ブレーキ26の締結室26Ａとに連通される。したがって、１速から２速への変速時および２速から１速への変速時に、ローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａ内の油圧が上記三方デューティソレノイド弁31によりデューティ制御され、変速が行われる。なお、上記切換弁33が第１の切換位置にあるとき、ロックアップクラッチ14を作動させる差圧制御弁32に接続された油路ｈ内の作動油はドレーンされている。
【００３８】
一方、３速および４速では、油路ｇ内に作動油が後述する経路で供給され、この油圧が上記切換弁33に対してパイロット圧が作用することにより、この切換弁33は、図３（３速状態）および図４（４速状態）に示す第２の切換位置に切換えられる。この場合は、三方デューティソレノイド弁38の下流側の油路ｆが、ロックアップクラッチ14を作動させる差圧制御弁32に接続された油路ｈに連通して、三方デューティソレノイド弁31によるロックアップクラッチ14のスリップ制御が可能になる。
【００３９】
また、３速および４速において、ローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａ内の油圧（油路ｅ内の油圧）をライン圧（元圧）に保つために、３速および４速において油路ｃを油路ｅに接続する元圧供給用油路ｉが設けられている。この油路ｉは、図２から明らかなように、切換弁33が第１の切換位置にあるときには、切換弁33によって閉塞されているが、切換弁33が第１の切換位置から第２の切換位置への切換に伴って、図３および図４に示すように、切換弁33を介して油路ｅに連通されるように構成されている。
【００４０】
また、上記油路ｅから分岐された油路ｊと、２−４ブレ−キ26の解放室26Ｒに連通する油路ｋと間に、ドレーンポートを備えた常開型の三方デューティソレノイド弁34（符号Ｂで示されている）が介装されている。
【００４１】
この三方デューティソレノイド弁34は、２速と３速との間の変速に際して、２−４ブレ−キ26の解放室26Ｒおよび３−４クラッチ24の締結室24Ａに対し供給・排出される作動油の油圧をデューティ制御し、かつ３速と４速との間の変速に際して、２−４ブレ−キ26の解放室26Ｒに対し供給・排出される作動油の油圧をデューティ制御するために設けられたソレノイド弁である。
【００４２】
さらに、上記油路ｋから油路ｍが分岐され、この油路ｍが、１速〜３速で第１の切換位置にあるスプリングオフセット・パイロット方式の９ポート２位置切換弁35を介して、３−４クラッチ24の締結室24Ａに連通する油路ｇに接続されている。上記三方デューティソレノイド弁34は、３速のみにおいてＯＦＦ状態とされ、３速以外ではＯＮ状態とされるので、１速および２速では油路ｊが閉塞され、かつ油路ｋおよび油路ｍ内の作動油がこのソレノイド弁34のドレーンポートから排出される。そして、２速と３速との間の変速時および３速と４速との間の変速時に、２−４ブレ−キ26の解放室26Ｒおよび３−４クラッチ24の締結室24Ａ内の油圧が、三方デューティソレノイド弁34によりデューティ制御されるように構成されている。
【００４３】
一方、上記切換弁35に対しては、油路ａのライン圧が、ドレーンポートを備えたＯＮ／ＯＦＦソレノイド弁36（符号ＯＮ／ＯＦＦで示されている）を介してパイロット圧として与えられるようになっている。そして、このソレノイド弁36は、１速〜３速ではＯＦＦ状態とされるので、ライン圧がパイロット圧として印加されて、切換弁35は図２に示す第１の切換位置にあり、これによって、油路ｃとフォワードクラッチ21の締結室21Ａに通じる油路ｎとが連通され、フォワードクラッチ21が締結される。
【００４４】
ここで、上記三方デューティソレノイド弁31，34およびＯＮ／ＯＦＦソレノイド弁36の動作を表３に示す。
【００４５】
【表３】

【００４６】
１速〜３速では、第１の切換位置にある切換弁35を介して油路ｍと油路ｇとが連通されるが、表３から明らかなように、３速では三方デューティソレノイド弁34がＯＦＦ状態とされて、そのドレーンポートが閉じられ、かつ入出力ポート間が連通されるので、油路ｊに供給された作動油は、油路ｍおよび切換弁35を介して油路ｇに供給され、３−４クラッチ24が締結される。また、シャトル弁３７が設けられ、このシャトル弁３７の一方の入力ポートが油路ｃに接続され、他方の入力ポートが、切換弁35を介してドレーン状態の油路ｄに連通する油路ｐに接続され、出力ポートが、油路ｑを通じてローリバースブレーキ27の締結室27Ａに連通していることにより、１速〜３速において、作動油が油路ｃからシャトル弁３７を通ってローリバースブレーキ27の締結室27Ａに供給される。
【００４７】
そして、１速では、三方デューティソレノイド弁31がＯＮ状態とされて、ローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａ内の作動油がソレノイド弁31のドレーンポートから排出されていることにより、ローリバースブレーキ27が締結される。また、三方デューティソレノイド弁34もＯＮ状態とされるので、２−４ブレーキ26の解放室26Ｒおよび３−４クラッチ24の締結室24Ａには油圧が印加されず、２−４ブレーキ26および３−４クラッチ24が解放されている。
【００４８】
次に、２速では、三方デューティソレノイド弁31がＯＦＦ状態とされることにより、ライン圧がこの常開型のソレノイド弁31を経由してローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａに印加されて、ローリバースブレーキ27が解放される。また、三方デューティソレノイド弁34はＯＮ状態とされるので、２−４ブレーキ26の解放室26Ｒおよび３−４クラッチ24の締結室24Ａには油圧が印加されず、２−４ブレーキ26は締結され、３−４クラッチ24は解放される。
【００４９】
さらに３速では、三方デューティソレノイド弁34がＯＦＦ状態とされることにより、ライン圧が油路ｊ，常開型のソレノイド弁34，油路ｍ，切換弁35および油路ｇを経由して３−４クラッチ24の締結室24Ａに印加されるため、３−４クラッチ24が締結される。そして、３−４クラッチ24の締結室24Ａに供給される作動油の油圧（油路ｇ内の油圧）により、切換弁33が図３に示す第２の切換位置に切換えられ、三方デューティソレノイド弁31による差圧制御弁32を介してのロックアップクラッチ14のスリップ制御が可能になる（４速でも同様）。また、油路ｉを経由した作動油が、ローリバースブレーキ27の解放室27Ｒと、２−４ブレーキ26の締結室26Ａおよび解放室26Ｒとに印加されるため、ローリバースブレーキ27および２−４ブレーキ26が解放される。さらに、油路ｉを経由した作動油が油路ｊ，常開型のソレノイド弁34，油路ｍ，切換弁35および油路ｇを経由して３−４クラッチ24の締結室24Ａに印加されるため、３−４クラッチ24の締結状態が維持される。
【００５０】
次に、ソレノイド弁36が４速でＯＮになると、そのドレーンポートが開くため、切換弁35に対するパイロット圧が消滅して、切換弁35は、図４に示すように、スプリングの付勢力で第２の切換位置に移動して、油路ｃとフォワードクラッチ21の締結室21Ａに通じる油路ｎとの間が遮断され、かつフォワードクラッチ21の締結室21Ａ内の作動油が切換弁35を通じてドレーンされるため、フォワードクラッチ21が解放される。また、油路ｅから分岐された油路ｒが切換弁35を介して油路ｇに連通するため、３−４クラッチ24が引続き締結される。さらに、三方デューティソレノイド弁34がＯＮ状態とされることにより、２−４ブレーキ26の解放室26Ｒ内の作動油がソレノイド弁34のドレーンポートから排出され、２−４ブレーキ26が締結される。
【００５１】
一方、Ｒレンジが選択されて、油路ｄにライン圧が供給されたとき、油路ｃ内の作動油はドレーンされるから、ライン圧は、油路ｄからリバースクラッチ25の締結室25Ａに印加され、リバースクラッチ25が締結される。また、油路ｄから分岐された油路ｓ，切換弁35，油路ｐ，シャトル弁37および油路ｑ通じて、ローリバースブレーキ27の締結室27Ａに作動油が供給されるが、三方デューティソレノイド弁31がＯＮ状態とされるので、ローリバースブレーキ27の解放室27Ｒ内の作動油がソレノイド弁31を通じてドレーンされ、ローリバースブレーキ27が締結される。
【００５２】
さらに、図２から明らかなように、フォワードクラッチ21の締結室21Ａに接続された油路ｎおよびリバースクラッチ25の締結室25Ａに接続された油路ｄには、モデュレータバルブ29により、エンジントルクに応じて背圧を制御されるアキュムレータ38および39がそれぞれ接続されている。油路ｎに接続されたアキュムレータ38は、マニュアルバルブ30のＮレンジからＤレンジへのシフト操作時および４速から３速への変速時に、フォワードクラッチ21の締結室21Ａ内の油圧を緩やかに上昇させるとともに、３速から４速への変速時にフォワードクラッチ21の締結室21Ａ内の油圧を緩やかに下降させる棚圧形成機能を有する。
【００５３】
また、油路ｄに接続されたアキュムレータ39は、マニュアルバルブ30のＮレンジからＲレンジへのシフト操作時に、リバースクラッチ25の締結室25Ａ内の油圧を緩やかに上昇させる棚圧形成機能を有する。
【００５４】
図５および図６は、変速時における油圧の変化を示すタイミングチャートである。
【００５５】
まず、図５(A)は、マニュアルバルブ30のＮレンジからＲレンジへのシフト操作時における、ローリバースブレーキ27の締結室27内の油圧ＰＡ_L-RBおよびフォワードクラッチ21の締結室21Ａ内の油圧ＰＡ_FWCの変化を示し、ローリバースブレーキ27の締結室27内の油圧ＰＡ_L-RBは急速に立ち上がるが、フォワードクラッチ21の締結室21Ａ内の油圧ＰＡ_FWCはアキュムレータ38の作用により、緩やかに上昇することを示している。
【００５６】
図５(B)は、１速から２速への変速時において、三方デューティソレノイド弁31によりデューティ制御されるローリバースブレーキ27の解放室27Ｒ内の油圧ＰＲ_L-RBおよびこれに等しい２−４ブレーキ26の締結室26Ａ内の油圧ＰＡ_2-4Bの変化を示す。
【００５７】
図５(C)は、２速から３速への変速時において、三方デューティソレノイド弁34によりデューティ制御される２−４ブレーキ26の解放室26Ｒ内の油圧ＰＲ_2-4Bおよびこれに等しい３−４クラッチ24の締結室24Ａ内の油圧ＰＡ_3-4Cの変化を示す。
【００５８】
図５(D)は、３速から４速への変速時において、三方デューティソレノイド弁34によりデューティ制御される２−４ブレーキ26の解放室26Ｒ内の油圧ＰＲ_2-4Bの変化と、アキュムレータ38の作用により緩やかに下降するフォワードクラッチ21の締結室21Ａ内の油圧ＰＡ_FWCの変化を示す。
【００５９】
図６(A)は、ＮレンジからＲレンジへのシフト操作時における、ローリバースブレーキ27の解放室27Ｒ内の油圧ＰＲ_L-RBおよびリバースクラッチ25の締結室25Ａ内の油圧ＰＡ_REVCの変化を示す。ローリバースブレーキ27の締結室27内の油圧ＰＡ_L-RBは急速に立ち上がるが、リバースクラッチ25の締結室25Ａ内の油圧ＰＡ_REVCはアキュムレータ38の作用により、緩やかに上昇することを示している。
【００６０】
次の図６(B)は、２速から１速への変速時において、三方デューティソレノイド弁31によりデューティ制御される、ローリバースブレーキ27の解放室27Ｒ内の油圧ＰＲ_L-RBおよびこれに等しい２−４ブレーキ26の締結室26Ａ内の油圧ＰＡ_2-4Bの変化を示す。
【００６１】
図６(C)は、３速から２速への変速時において、三方デューティソレノイド弁34によりデューティ制御される、２−４ブレーキ26の解放室26Ｒ内の油圧ＰＲ_2-4Bおよびこれに等しい３−４クラッチ24の締結室24Ａ内の油圧ＰＡ_3-4Cの変化を示す。
【００６２】
図６(D)は、４速から３速への変速時において、三方デューティソレノイド弁34によりデューティ制御される、２−４ブレーキ26の解放室26Ｒ内の油圧ＰＲ_2-4Bの変化と、アキュムレータ38の作用により緩やかに上昇するフォワードクラッチ21の締結室21Ａ内の油圧ＰＡ_FWCを示す。
【００６３】
以上の説明で、本実施例における油圧制御回路の構成および動作が明らかとなったが、本実施例によれば、三方デューティソレノイド弁31により油圧を制御される作動油が出力される油路ｆを切換える切換弁33が設けられ、この切換弁33の第１の切換位置において、上記油路ｆがローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａに接続されることにより、図５(B)および図６(B)に示す１速と２速との間の変速時に、上記三方デューティソレノイド弁31による、ローリバースブレーキ27の解放室27Ｒ内の油圧ＰＲ_L-RBおよび２−４ブレーキ26の締結室26Ａ内の油圧ＰＡ_2-4Bのデューティ制御が可能になる。
【００６４】
また、３速および４速において切換弁33が第２の切換位置に切換えられた場合には、上記油路ｆが、ロックアップクラッチ14の制御手段である差圧制御弁32に接続されるとともに、ローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａに対し、ライン圧を上記切換弁33を介して印加するための油路ｉが設けられていることにより、上記三方デューティソレノイド弁31による、ロックアップクラッチ14のスリップ制御を行いながら、３速および４速におけるローリバースブレーキ27の解放状態の維持と、４速における２−４ブレーキ26の締結状態の維持とを行うことができる。
【００６５】
また、上記切換弁33は、３速および４速において締結される３−４クラッチ24の締結圧をパイロット圧として、第１の切換位置から第２の切換位置に切換えられるように構成されているため、上記切換弁33のためのパイロット圧形成手段を別途にもうけなくても良い利点がある。
【００６６】
さらに、本実施例では、同時に締結されるとインタロックを発生する関係にあるローリバースブレーキ27の解放室27Ｒと２−４ブレーキ26の締結室26Ａとが油路ｅを介して連通され、かつ上記ローリバースブレーキ27の解放室27Ｒおよび２−４ブレーキ26の締結室26Ａ内の油圧が三方デューティソレノイド弁31により制御されるように構成されているため、ローリバースブレーキ27と２−４ブレーキ26とが同時に締結されるおそれは全くない。
【００６７】
また、ローリバースブレーキ27と同時に締結されるとインタロックを発生する関係にある３−４クラッチ24の締結室24Ａに連通する油路ｇが、ローリバースブレーキ27の解放室27Ｒに通じる油路ｅから分岐された形になっているので、ローリバースブレーキ27と３−４クラッチ24とが同時に締結されるおそれも全くなくなる。
【００６８】
なお、本実施例では、ローリバースブレーキ27と２−４ブレーキ26と３−４クラッチ24とを、デューティソレノイド弁31，34によって直接制御しているが、図７に示すように、デューティソレノイド弁31，34に代えて、デューティソレノイド弁51によって制御される調圧弁52を用いても、同様の効果を得ることができる。
【図面の簡単な説明】
【図１】本発明に係わる自動変速機の機械的構成を示すスケルトン図
【図２】同 １速および２速における油圧制御回路の概略図
【図３】同 ３速における油圧制御回路の概略図
【図４】同 ４速における油圧制御回路の概略図
【図５】同 変速時において摩擦締結要素に対し給排される作動油の油圧の変化を示すタイミングチャート
【図６】同 変速時において摩擦締結要素に対し給排される作動油の油圧の変化を示すタイミングチャート
【図７】調圧手段の変形を示す回路図
【符号の説明】
３ トルクコンバータ
５ 歯車変速機構
21 フォワードクラッチ
24 ３−４クラッチ （特定の変速段で締結される摩擦締結要素）
25 リバースクラッチ
26 ２−４ブレーキ （所定の摩擦締結要素）
27 ローリバースブレーキ （所定の摩擦締結要素）
31 三方デューティソレノイド弁 （電磁ソレノイド弁）
32 差圧制御弁 （ロックアップクラッチの制御手段）
33 ５ポート２位置切換弁 （切換手段）
34 三方デューティソレノイド弁
35 ９ポート２位置切換弁
38，39 アキュムレータ[0001]
[Industrial applications]
The present invention relates to a hydraulic control device for an automatic transmission, and more particularly to a common electromagnetic solenoid that controls hydraulic pressure of hydraulic oil supplied to a predetermined friction engagement element and slip control of a lock-up clutch at a specific gear position. The present invention relates to a hydraulic control device for an automatic transmission configured to be controlled by a valve.
[0002]
[Prior art]
Generally, an automatic transmission for a vehicle includes a torque converter and a multi-stage transmission mechanism using a planetary gear mechanism and the like, and various clutches, brakes and other friction engagement elements for switching a power transmission path in the multi-stage transmission mechanism are provided. In this case, by changing the engagement / release state of these friction engagement elements in various ways, by selectively connecting a plurality of rotation elements in a planetary gear mechanism or the like, or by braking the rotation of a specific rotation element, Is automatically selected for the driving state of the vehicle. The engagement or release of the friction engagement element is usually performed by a hydraulic circuit.
[0003]
However, a conventional automatic transmission for a vehicle incorporates a shift valve that is switched according to a throttle opening and a vehicle speed, a regulator valve that controls a line pressure, and an accumulator that sets an engagement pressure characteristic of each friction engagement element. Therefore, when the number of gears is increased, the required number of shift valves and accumulators increases, the valve body becomes larger, the hydraulic circuit becomes more complicated, and the weight, volume and price increase. This has been a major obstacle to miniaturization and price reduction of automatic transmissions.
[0004]
In addition, the accumulator sets the engagement pressure characteristics of the friction engagement element by the orifice and spring force, so that accurate shock control cannot be performed for all shift conditions such as throttle opening, vehicle speed, oil temperature, etc. However, there is a problem that it is difficult to adjust different types of automatic transmissions.
[0005]
For this reason, conventionally, by using an electromagnetic solenoid valve such as a duty solenoid valve, the hydraulic pressure of the hydraulic oil supplied to the friction engagement element can be controlled to an arbitrary value, so that a shift valve, an accumulator, and the like can be controlled. Automatic transmissions have also been proposed that reduce the number and simplify the hydraulic control circuit to reduce size and cost. This The electromagnetic solenoid valve used for such a purpose is expensive, which hinders a reduction in the price of the entire automatic transmission. In particular, when controlling two frictional engagement elements simultaneously, two electromagnetic solenoid valves are inevitably required. Further, when the slip control of the lock-up clutch is to be performed, only three electromagnetic solenoid valves are required. A solenoid valve is required.
[0006]
Therefore, in a hydraulic control device for an automatic transmission described in, for example, Japanese Patent Application Laid-Open No. 1-164848, a switching valve that switches an oil passage to which hydraulic oil whose hydraulic pressure is controlled by an electromagnetic solenoid valve is supplied in accordance with a gear position. Is provided, the number of electromagnetic solenoid valves used is reduced, and the cost is reduced.
[0007]
Further, as disclosed in Japanese Patent Application Laid-Open No. 2-278076, the configuration of a hydraulic control circuit is achieved by controlling both the lock-up clutch and the emblem clutch using only the control hydraulic pressure from one electromagnetic solenoid valve. There is also known an automatic transmission control device for simplifying and reducing the size of the automatic transmission.
[0008]
[Problems to be solved by the invention]
By the way, a switching valve for switching an oil passage to which hydraulic oil whose hydraulic pressure is controlled by an electromagnetic solenoid valve is supplied in accordance with a shift speed is provided, and one electromagnetic solenoid valve controls hydraulic pressure of a predetermined frictional engagement element and locks up. Perform clutch slip control Sea urchin At this time, depending on the configuration of the frictional engagement element, it may be necessary to apply a constant hydraulic pressure to the predetermined frictional engagement element at the shift speed at which the slip control of the lock-up clutch is performed. However, this is difficult with the configuration of the conventional hydraulic control circuit.
[0009]
In view of the circumstances described above, the present invention provides a very simple configuration that allows a single solenoid valve to be used for both hydraulic control of a predetermined frictional engagement element and slip control of a lock-up clutch. It is an object of the present invention to provide a hydraulic control device for an automatic transmission that can apply a constant hydraulic pressure to the above-mentioned predetermined frictional engagement element at a shift speed at which control is performed.
[0010]
[Means for Solving the Problems]
A hydraulic control device for an automatic transmission according to the present invention includes a first switching position for connecting an oil passage, to which hydraulic oil whose hydraulic pressure is controlled by an electromagnetic solenoid valve is supplied, to a predetermined friction engagement element; And a switching means for selectively switching to a second switching position connected to the control means of the lock-up clutch, and when the oil passage is connected to the control means of the lock-up clutch by the switching means. And a source pressure supply means for supplying a source pressure to the predetermined frictional engagement element.
[0011]
The source pressure supply means is operated in accordance with the switching of the switching means from the first switching position to the second switching position, and the switching means is adapted to engage at a specific speed. It comprises a switching valve operated by the hydraulic pressure of the hydraulic oil supplied to the fastening element.
[0012]
According to one aspect of the present invention, the electromagnetic solenoid valve controls hydraulic pressure of hydraulic oil supplied to a predetermined frictional engagement element during a shift between the first speed and the second speed, and The above-mentioned specific shift speed at which the slip control is performed includes a third speed and a fourth speed.
[0013]
[Action and effect of the invention]
According to the present invention, the oil passage to which the hydraulic oil whose hydraulic pressure is controlled by the electromagnetic solenoid valve is supplied is connected to the first friction switching element at the first switching position, and at the specific shift speed (for example, third speed and fourth speed). (Speed), the switching means for selectively switching to the second switching position connected to the control means of the lock-up clutch is provided. The hydraulic pressure of the hydraulic oil supplied to the frictional engagement element can be controlled, and the original pressure for supplying the original pressure to the predetermined frictional engagement element when the switching means is switched to the second switching position. Since the supply means is provided, while the lock-up clutch is controlled by the electromagnetic solenoid valve while maintaining a very simple configuration, a certain amount of oil is supplied to the predetermined frictional engagement element. It is easy to keep applying.
[0014]
Further, when the switching means comprises a switching valve that is operated by the hydraulic pressure of the hydraulic oil supplied to the frictional engagement element that is engaged at the specific shift speed, it is not necessary to separately provide an operating pressure for the switching valve. There are advantages.
[0015]
【Example】
Hereinafter, an embodiment of a hydraulic control device for an automatic transmission according to the present invention will be described with reference to the drawings.
[0016]
As shown in FIG. 1, in the automatic transmission AT, a torque converter 3 for shifting the torque of the engine output shaft 1 and transmitting the torque to the turbine shaft 2 and a further reverse gear for further shifting the torque of the turbine shaft 2 are selected. And a transmission gear mechanism 5 that reverses the rotation when the rotation is in progress and outputs the rotation from the output gear 4 to the driving wheel side. The turbine shaft 2 is formed in a pipe shape, and an oil pump shaft 6 connected to the engine output shaft 1 is disposed in a hollow portion thereof. The oil pump 7 arranged on the left side) is driven to rotate.
[0017]
The torque converter 3 includes a pump 9 connected to the engine output shaft 1 via a connecting member 8, a turbine 10 connected to the turbine shaft 2 and rotationally driven by hydraulic oil discharged from the pump 9, and a And a stator 11 for rectifying the hydraulic oil recirculated to the pump 9 in a direction to promote the rotation of the pump 9, and the torque of the engine output shaft 1 at a speed ratio according to a rotational speed difference between the pump 9 and the turbine 10. The speed is changed. Stator 11 is fixed to transmission case 13 via one-way clutch 12. Reference numeral 14 denotes a lock-up clutch for directly connecting the engine output shaft 1 and the turbine shaft 2 without passing through the torque converter 3.
[0018]
The transmission gear mechanism 5 is a well-known Ravigneaux type planetary gear device. The transmission gear mechanism 5 includes a relatively small diameter small sun gear 15 loosely fitted to the turbine shaft 2 and a small sun gear 15. , A large sun gear 16 having a relatively large diameter loosely fitted to the turbine shaft 2, a plurality of short pinion gears 17 meshing with the small sun gear 15, a front portion (the right side in FIG. 1) meshing with the short pinion gear 17, and a rear portion. A long pinion gear 18 meshing with the large sun gear 16, a ring gear (internal gear) 19 meshing with the long pinion gear 18, and a carrier 20 rotatably supporting the short pinion gear 17 and the long pinion gear 18 are provided.
[0019]
In the transmission gear mechanism 5 configured as described above, the small sun gear 15, the large sun gear 16 or the carrier 20 serves as a torque input unit according to the shift speed, while the ring gear 19 serves as an output unit at any shift speed. Therefore, the output gear 4 is connected to the ring gear 19.
[0020]
A plurality of clutches and brakes are provided for switching the torque transmission path in the transmission gear mechanism 5.
[0021]
That is, a forward clutch 21 for driving the small sun gear 15 is interposed between the turbine shaft 2 and the small sun gear 15, and the carrier 20 is provided between the turbine shaft 2 and the carrier 20 at the third speed and the fourth speed. A driving 3-4 clutch 24 is provided, and a reverse clutch 25 for driving the large sun gear 16 at the time of retreat is provided between the turbine shaft 2 and the large sun gear 16. Further, between the large sun gear 16 and the reverse clutch 25, a 2-4 brake 26 comprising a band brake for fixing the large sun gear 16 at the second and fourth speeds is provided. Further, between the carrier 20 and the transmission case 13, a low reverse brake 27 for fixing the carrier 20 at the first speed and when reversing is provided.
[0022]
The transmission gear mechanism 5 itself has four forward speeds and one reverse speed, and operates the clutches 21, 24, 25 and brakes 26, 27 which are frictional engagement elements as needed to achieve the required speed. Can be obtained.
[0023]
FIG. 2 shows a hydraulic control circuit for the automatic transmission AT of FIG. In the following description with reference to FIG. 2, ranges (N range, P range, etc.) other than the D range and the R range are omitted, and all the switching valves in FIG. The switching positions in the second speed and the second speed are shown.
[0024]
In FIG. 2, the 3-4 clutch 24, the forward clutch 21, and the reverse clutch 25 are provided with only engagement chambers 24A, 21A, 25A (A means apply) to which the engagement hydraulic pressure is supplied. The reverse brake 27 and the 2-4 brake 26 are respectively provided with release chambers 27R and 26R (R means release) in which release hydraulic pressure is supplied in addition to the engagement chambers 27A and 26A to which the engagement hydraulic pressure is supplied. Are provided respectively.
[0025]
Thus, in the friction fastening element having both the fastening chamber and the release chamber, the fastening is performed when the hydraulic pressure is applied only to the fastening chamber, and the hydraulic pressure is applied to both the fastening chamber and the release chamber. Is released when no pressure is applied to both the engagement chamber and the release chamber.
[0026]
Here, Table 1 shows the operating relationship between each gear and the clutch and brake. In Table 1, the state where the hydraulic pressure is applied is indicated by “「 ”.
[0027]
[Table 1]

[0028]
As is apparent from Table 1, the low reverse brake 27 and the 2-4 brake 26 are involved in the shift during the shift between the first speed and the second speed, and the second reverse brake 27 and the 2-4 brake 26 are involved in the shift between the second speed and the third speed. The -4 brake 26 and the 3-4 clutch 24 are involved in shifting, and during shifting between the third and fourth speeds, the 2-4 brake 26 and the forward clutch 21 are involved in shifting, and one of them is released. And the other is fastened. That is, in the first speed, the low reverse brake 27 is engaged and the 2-4 brake 26 is released. In the second speed, the 2-4 brake 26 is engaged and the 3-4 clutch 24 is released. 2-4 brake 26 is released and the 3-4 clutch 24 is engaged. In the third speed, the 2-4 brake 26 is released and the forward clutch 21 is engaged, but when shifting to the 4th speed, the 2-4 brake 26 is engaged and the forward clutch 21 is released.
[0029]
Further, Table 2 shows the frictional fastening elements that have a relation of interlocking the power transmission paths when they are simultaneously engaged.
[0030]
[Table 2]

[0031]
As is apparent from Table 2, when the low reverse brake 27 and the 2-4 brake 26 are simultaneously engaged, and when the low reverse brake 27 and the 3-4 clutch 24 are simultaneously engaged, the power transmission path is Because of the interlock, the hydraulic circuit of FIG. 2 is configured to prevent the occurrence of this interlock.
[0032]
Next, the configuration and operation of various valves for supplying and discharging hydraulic oil to and from the engagement chamber and the release chamber of each friction engagement element shown in FIG. 2 will be described in detail.
[0033]
The hydraulic oil pressurized by the oil pump 7 is supplied to the pressure regulator valve 23 via the oil passage a. In order to control the pressure regulator valve 23, a two-way duty solenoid valve 28 (denoted by a symbol C) and a modulator valve 29 are provided, and the solenoid valve 28 adjusts the engine torque ( A pilot pressure (generally corresponding to the throttle opening) is output, and the output pressure (line pressure) of the pressure regulator valve 23 is adjusted via the modulator valve 29 in accordance with the engine torque. The line pressure thus obtained is supplied to the manual valve 30 via the oil passage b.
[0034]
In order to simplify the drawing, the manual valve 30 is illustrated as a two-port two-position switching valve for switching between a D range and an R range, and the N range and others are omitted. The line pressure supplied to the manual valve 30 is selectively transmitted to one of the two oil passages c and d depending on the position of the shift lever. That is, when the line pressure is transmitted to the oil passage c in the D range, and is transmitted to the oil passage d in the R range, and one of the oil passages c and d is selected and the line pressure is transmitted thereto. The hydraulic oil in the other oil passage is configured to be drained.
[0035]
On the other hand, in order to prevent the low reverse brake 27 and the 2-4 brake 26 from being simultaneously engaged, the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 are connected via the oil passage e. Between the oil passage e and the oil passage c, a normally open three-way duty solenoid valve 31 having a drain port (indicated by reference numeral A) and a switching valve 33 connect the oil passage f. It is interposed between them.
[0036]
The three-way duty solenoid valve 31 is used to supply and discharge hydraulic oil to / from the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 when shifting between the first speed and the second speed. In order to control the torque capacity of the low reverse brake 27 and the 2-4 brake 26 by performing the duty control, and to perform the slip control of the lock-up clutch 14 via the differential pressure control valve 32 in the third speed and the fourth speed. Solenoid valve provided for the purpose. The switching valve 33 is a 5-port 2-position switching valve of a spring offset pilot type, and is provided with a hydraulic pressure in an oil passage g communicating with the engagement chamber 24A of the 3-4 clutch 24 engaged at the third speed and the fourth speed. This acts as a pilot pressure on the switching valve 33.
[0037]
That is, as is clear from Table 1, at the first speed and the second speed, the hydraulic oil in the engagement chamber 24A of the 3-4 clutch 24 is discharged through a path described later, so that the switching valve 33 is No pressure is applied, so the switching valve 33 is in the first switching position shown in FIG. 2 by the biasing force of the offset spring, and the oil passage f downstream of the three-way duty solenoid valve 31 is connected to the switching valve 33 and the oil. The road e is communicated with the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 via the path e. Therefore, during the shift from the first speed to the second speed and during the shift from the second speed to the first speed, the hydraulic pressure in the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 increases the hydraulic pressure in the three-way duty solenoid valve 31. , And the speed is changed. When the switching valve 33 is at the first switching position, the hydraulic oil in the oil passage h connected to the differential pressure control valve 32 for operating the lock-up clutch 14 is drained.
[0038]
On the other hand, at the third speed and the fourth speed, the operating oil is supplied into the oil passage g through a path described later, and the hydraulic pressure causes the pilot pressure to act on the switching valve 33. (3rd speed state) and the second switching position shown in FIG. 4 (4th speed state). In this case, the oil passage f on the downstream side of the three-way duty solenoid valve 38 communicates with the oil passage h connected to the differential pressure control valve 32 that operates the lock-up clutch 14, and the lock-up by the three-way duty solenoid valve 31 is performed. Slip control of the clutch 14 becomes possible.
[0039]
In order to maintain the hydraulic pressure (the hydraulic pressure in the oil passage e) in the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 at the third speed and the fourth speed at the line pressure (source pressure), An oil passage i for supplying the original pressure is provided to connect the oil passage c to the oil passage e at the third speed and the fourth speed. As is apparent from FIG. 2, when the switching valve 33 is at the first switching position, the oil passage i is closed by the switching valve 33, but the switching valve 33 is moved from the first switching position to the second switching position. With the switching to the switching position, as shown in FIGS. 3 and 4, it is configured to communicate with the oil passage e via the switching valve 33.
[0040]
A normally open three-way duty solenoid valve 34 having a drain port is provided between an oil passage j branched from the oil passage e and an oil passage k communicating with the release chamber 26R of the 2-4 brake 26. (Indicated by the symbol B) are interposed.
[0041]
The three-way duty solenoid valve 34 supplies and discharges hydraulic oil to / from the release chamber 26R of the 2-4 brake 26 and the engagement chamber 24A of the 3-4 clutch 24 when shifting between the second and third speeds. For controlling the hydraulic pressure of the hydraulic oil supplied to and discharged from the release chamber 26R of the 2-4 brake 26 at the time of shifting between the third speed and the fourth speed. It is a solenoid valve.
[0042]
Further, an oil passage m is branched from the oil passage k, and the oil passage m is passed through a 9-port 2-position switching valve 35 of a spring offset / pilot type which is in a first switching position at first speed to third speed. It is connected to an oil passage g communicating with the engagement chamber 24A of the 3-4 clutch 24. Since the three-way duty solenoid valve 34 is turned off only in the third speed and turned on in other than the third speed, the oil passage j is closed at the first and second speeds, and the oil passage k and the oil passage m are not closed. Is discharged from the drain port of the solenoid valve 34. The hydraulic pressure in the release chamber 26R of the 2-4 brake 26 and the hydraulic pressure in the engagement chamber 24A of the 3-4 clutch 24 at the time of shifting between the second and third speeds and at the time of shifting between the third and fourth speeds. Is configured to be duty-controlled by a three-way duty solenoid valve.
[0043]
On the other hand, the line pressure of the oil passage a is supplied to the switching valve 35 as a pilot pressure via an ON / OFF solenoid valve 36 (shown by the symbol ON / OFF) having a drain port. It has become. Since the solenoid valve 36 is turned off in the first to third speeds, the line pressure is applied as the pilot pressure, and the switching valve 35 is in the first switching position shown in FIG. The oil passage c communicates with the oil passage n communicating with the engagement chamber 21A of the forward clutch 21, and the forward clutch 21 is engaged.
[0044]
Table 3 shows the operation of the three-way duty solenoid valves 31, 34 and the ON / OFF solenoid valve 36.
[0045]
[Table 3]

[0046]
In the first to third speeds, the oil passage m and the oil passage g are communicated via the switching valve 35 at the first switching position. As is clear from Table 3, in the third speed, the three-way duty solenoid valve 34 is connected. Is turned off, the drain port is closed, and the input and output ports are communicated with each other, so that the hydraulic oil supplied to the oil passage j flows to the oil passage g via the oil passage m and the switching valve 35. Supplied, and the 3-4 clutch 24 is engaged. Further, a shuttle valve 37 is provided. One input port of the shuttle valve 37 is connected to an oil passage c, and the other input port is connected to an oil passage p which is in communication with a drain oil passage d via a switching valve 35. And the output port communicates with the engagement chamber 27A of the low reverse brake 27 through the oil passage q, so that the hydraulic oil flows from the oil passage c through the shuttle valve 37 through the shuttle valve 37 in the first to third speeds. It is supplied to the fastening chamber 27A of the brake 27.
[0047]
In the first speed, the three-way duty solenoid valve 31 is turned on, and the hydraulic oil in the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 is discharged from the drain port of the solenoid valve 31. As a result, the low reverse brake 27 is engaged. Further, since the three-way duty solenoid valve 34 is also turned on, no hydraulic pressure is applied to the release chamber 26R of the 2-4 brake 26 and the engagement chamber 24A of the 3-4 clutch 24, so that the 2-4 brake 26 and 3- Four clutch 24 is released.
[0048]
Next, in the second speed, the three-way duty solenoid valve 31 is turned off, so that the line pressure passes through the normally open type solenoid valve 31 and the release chamber 27R of the low reverse brake 27 and the 2-4 brake 26 And the low reverse brake 27 is released. Since the three-way duty solenoid valve 34 is turned on, no hydraulic pressure is applied to the release chamber 26R of the 2-4 brake 26 and the engagement chamber 24A of the 3-4 clutch 24, and the 2-4 brake 26 is engaged. The 3-4 clutch 24 is released.
[0049]
Further, at the third speed, the three-way duty solenoid valve 34 is turned off, so that the line pressure is reduced via the oil passage j, the normally open solenoid valve 34, the oil passage m, the switching valve 35, and the oil passage g. Since the voltage is applied to the engagement chamber 24A of the -4 clutch 24, the 3-4 clutch 24 is engaged. The switching valve 33 is switched to the second switching position shown in FIG. 3 by the hydraulic pressure of the working oil supplied to the engagement chamber 24A of the 3-4 clutch 24 (the hydraulic pressure in the oil passage g), and the three-way duty solenoid valve The slip control of the lock-up clutch 14 via the differential pressure control valve 32 by the 31 can be performed (the same applies to the fourth speed). In addition, since the hydraulic oil that has passed through the oil passage i is applied to the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A and the release chamber 26R of the 2-4 brake 26, the low reverse brakes 27 and 2-4 The brake 26 is released. Further, the hydraulic oil passing through the oil passage i is applied to the engagement chamber 24A of the 3-4 clutch 24 via the oil passage j, the normally open solenoid valve 34, the oil passage m, the switching valve 35, and the oil passage g. Therefore, the engaged state of the 3-4 clutch 24 is maintained.
[0050]
Next, when the solenoid valve 36 is turned on at the fourth speed, the drain port opens, so that the pilot pressure on the switching valve 35 disappears, and the switching valve 35 is actuated by the urging force of the spring as shown in FIG. 2, the oil passage c is disconnected from the oil passage n communicating with the engagement chamber 21A of the forward clutch 21, and the hydraulic oil in the engagement chamber 21A of the forward clutch 21 is drained through the switching valve 35. Therefore, the forward clutch 21 is released. Further, since the oil passage r branched from the oil passage e communicates with the oil passage g via the switching valve 35, the 3-4 clutch 24 is continuously engaged. Further, when the three-way duty solenoid valve 34 is turned on, the hydraulic oil in the release chamber 26R of the 2-4 brake 26 is discharged from the drain port of the solenoid valve 34, and the 2-4 brake 26 is engaged.
[0051]
On the other hand, when the R range is selected and the line pressure is supplied to the oil passage d, the hydraulic oil in the oil passage c is drained. Therefore, the line pressure is applied from the oil passage d to the engagement chamber 25A of the reverse clutch 25. Is applied, and the reverse clutch 25 is engaged. The hydraulic oil is supplied to the engagement chamber 27A of the low reverse brake 27 through the oil passage s branched from the oil passage d, the switching valve 35, the oil passage p, the shuttle valve 37, and the oil passage q. Since the solenoid valve 31 is turned on, the hydraulic oil in the release chamber 27R of the low reverse brake 27 is drained through the solenoid valve 31, and the low reverse brake 27 is engaged.
[0052]
Further, as is apparent from FIG. 2, the oil passage n connected to the engagement chamber 21A of the forward clutch 21 and the oil passage d connected to the engagement chamber 25A of the reverse clutch 25 are connected to the engine valve by the modulator valve 29. Accumulators 38 and 39 whose back pressure is controlled according to the torque are connected respectively. The accumulator 38 connected to the oil passage n gently increases the hydraulic pressure in the engagement chamber 21A of the forward clutch 21 during a shift operation of the manual valve 30 from the N range to the D range and a shift from the fourth speed to the third speed. And a shelf pressure forming function for gradually lowering the oil pressure in the engagement chamber 21A of the forward clutch 21 when shifting from the third speed to the fourth speed.
[0053]
Further, the accumulator 39 connected to the oil passage d has a shelf pressure forming function of gradually increasing the oil pressure in the engagement chamber 25A of the reverse clutch 25 when the manual valve 30 shifts from the N range to the R range.
[0054]
FIG. 5 and FIG. 6 are timing charts showing changes in the hydraulic pressure during gear shifting.
[0055]
First, FIG. 5A shows the hydraulic pressure PA in the engagement chamber 27 of the low reverse brake 27 when the manual valve 30 is shifted from the N range to the R range. _L-RB And hydraulic pressure PA in the engagement chamber 21A of the forward clutch 21 _FWC And the hydraulic pressure PA in the engagement chamber 27 of the low reverse brake 27 _L-RB Rises rapidly, but the hydraulic pressure PA in the engagement chamber 21A of the forward clutch 21 _FWC Indicates that it gradually rises due to the action of the accumulator 38.
[0056]
FIG. 5B shows the hydraulic pressure PR in the release chamber 27R of the low reverse brake 27 that is duty-controlled by the three-way duty solenoid valve 31 during the shift from the first speed to the second speed. _L-RB And the hydraulic pressure PA in the fastening chamber 26A of the 2-4 brake 26 which is equal to this. _2-4B Shows the change in
[0057]
FIG. 5C shows the hydraulic pressure PR in the release chamber 26R of the 2-4 brake 26 whose duty is controlled by the three-way duty solenoid valve 34 during the shift from the second speed to the third speed. _2-4B And an equivalent hydraulic pressure PA in the engagement chamber 24A of the 3-4 clutch 24. _3-4C Shows the change in
[0058]
FIG. 5D shows the hydraulic pressure PR in the release chamber 26R of the 2-4 brake 26 that is duty-controlled by the three-way duty solenoid valve 34 during the shift from the third speed to the fourth speed. _2-4B And the hydraulic pressure PA in the engagement chamber 21A of the forward clutch 21, which gradually decreases due to the action of the accumulator 38. _FWC Shows the change in
[0059]
FIG. 6A shows the hydraulic pressure PR in the release chamber 27R of the low reverse brake 27 during the shift operation from the N range to the R range. _L-RB And hydraulic pressure PA in the engagement chamber 25A of the reverse clutch 25 _REVC Shows the change in Hydraulic pressure PA in fastening chamber 27 of low reverse brake 27 _L-RB Rises rapidly, but the hydraulic pressure PA in the engagement chamber 25A of the reverse clutch 25 _REVC Indicates that it gradually rises due to the action of the accumulator 38.
[0060]
FIG. 6B shows the hydraulic pressure PR in the release chamber 27R of the low reverse brake 27, which is duty-controlled by the three-way duty solenoid valve 31 during the shift from the second speed to the first speed. _L-RB And the hydraulic pressure PA in the fastening chamber 26A of the 2-4 brake 26 which is equal to this. _2-4B Shows the change in
[0061]
FIG. 6C shows the hydraulic pressure PR in the release chamber 26R of the 2-4 brake 26, which is duty-controlled by the three-way duty solenoid valve 34 during the shift from the third speed to the second speed. _2-4B And an equivalent hydraulic pressure PA in the engagement chamber 24A of the 3-4 clutch 24. _3-4C Shows the change in
[0062]
FIG. 6D shows the hydraulic pressure PR in the release chamber 26R of the 2-4 brake 26, which is duty-controlled by the three-way duty solenoid valve 34 during the shift from the fourth speed to the third speed. _2-4B And the hydraulic pressure PA in the engagement chamber 21A of the forward clutch 21 that rises slowly by the action of the accumulator 38. _FWC Is shown.
[0063]
In the above description, the configuration and operation of the hydraulic control circuit in the present embodiment have been clarified. However, according to the present embodiment, the oil passage f from which the hydraulic oil whose hydraulic pressure is controlled by the three-way duty solenoid valve 31 is output. A switching valve 33 is provided for switching the oil passage f. In the first switching position of the switching valve 33, the oil passage f is connected to the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26. 5 (B) and FIG. 6 (B), the hydraulic pressure PR in the release chamber 27R of the low reverse brake 27 by the three-way duty solenoid valve 31 during the shift between the first speed and the second speed. _L-RB And hydraulic pressure PA in fastening chamber 26A of 2-4 brake 26 _2-4B Duty control becomes possible.
[0064]
When the switching valve 33 is switched to the second switching position at the third speed and the fourth speed, the oil passage f is connected to the differential pressure control valve 32 which is a control means of the lock-up clutch 14, and The line pressure is applied to the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 via the switching valve 33. Was The oil passage i is provided to maintain the released state of the low reverse brake 27 in the third speed and the fourth speed while performing the slip control of the lock-up clutch 14 by the three-way duty solenoid valve 31, and It is possible to maintain the engaged state of the 2-4 brake 26 at the high speed.
[0065]
The switching valve 33 is configured to switch from the first switching position to the second switching position using the engagement pressure of the 3-4 clutch 24 engaged in the third speed and the fourth speed as the pilot pressure. Therefore, there is an advantage that a pilot pressure forming means for the switching valve 33 need not be separately provided.
[0066]
Further, in the present embodiment, the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26, which are in a relation of generating an interlock when simultaneously engaged, are communicated via the oil passage e, and Since the hydraulic pressure in the release chamber 27R of the low reverse brake 27 and the engagement chamber 26A of the 2-4 brake 26 are controlled by the three-way duty solenoid valve 31, the low reverse brake 27 and the 2-4 brake 26 And there is no possibility that they will be fastened at the same time.
[0067]
Further, an oil passage g communicating with the engagement chamber 24A of the 3-4 clutch 24, which has a relationship of generating an interlock when engaged simultaneously with the low reverse brake 27, is replaced with an oil passage e communicating with the release chamber 27R of the low reverse brake 27. Therefore, there is no possibility that the low reverse brake 27 and the 3-4 clutch 24 are simultaneously engaged.
[0068]
In this embodiment, the low reverse brake 27, the 2-4 brake 26, and the 3-4 clutch 24 are directly controlled by the duty solenoid valves 31 and 34. However, as shown in FIG. The same effect can be obtained by using a pressure regulating valve 52 controlled by a duty solenoid valve 51 instead of 31 and 34.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing a mechanical configuration of an automatic transmission according to the present invention.
FIG. 2 is a schematic diagram of a hydraulic control circuit in first and second speeds.
FIG. 3 is a schematic diagram of a hydraulic control circuit at the third speed.
FIG. 4 is a schematic diagram of a hydraulic control circuit at the fourth speed.
FIG. 5 is a timing chart showing a change in hydraulic pressure of hydraulic oil supplied / discharged to / from the friction engagement element at the time of the shift.
FIG. 6 is a timing chart showing a change in hydraulic pressure of hydraulic oil supplied / discharged to / from the friction engagement element at the time of the shift.
FIG. 7 is a circuit diagram showing a modification of the pressure adjusting means.
[Explanation of symbols]
3 Torque converter
5 Gear transmission mechanism
21 Forward clutch
24 3-4 clutch (Friction fastening element engaged at a specific gear position)
25 reverse clutch
26 2-4 Brake (predetermined friction fastening element)
27 Low reverse brake (predetermined friction fastening element)
31 Three-way duty solenoid valve (electromagnetic solenoid valve)
32 Differential pressure control valve (lock-up clutch control means)
33 5 port 2 position switching valve (switching means)
34 Three-way duty solenoid valve
35 9-port 2-position switching valve
38, 39 Accumulator

Claims (6)

A plurality of frictional engagement elements for switching a power transmission path by selective engagement; and an electromagnetic solenoid valve. The electromagnetic solenoid valve controls hydraulic pressure of hydraulic oil supplied to a predetermined frictional engagement element, and controls a specific gear position. In the hydraulic control device of the automatic transmission configured to perform the slip control of the lock-up clutch in the
A first switching position for connecting an oil passage to which the hydraulic oil whose hydraulic pressure is controlled by the electromagnetic solenoid valve is supplied to the predetermined frictional engagement element, and a control means for the lock-up clutch in the specific gear position. and switching means for switching selectively to the second switching position connecting,
When the oil passage is connected to the control unit of the lock-up clutch by the switching unit , a source pressure supply unit that supplies a source pressure to the predetermined friction engagement element ;
The hydraulic control device for an automatic transmission , wherein the electromagnetic solenoid valve controls the hydraulic pressure of hydraulic oil supplied to the predetermined frictional engagement element during a shift between a first speed and a second speed . 2. The hydraulic control of an automatic transmission according to claim 1, wherein said source pressure supply means is operated in accordance with switching of said switching means from said first switching position to said second switching position. apparatus. It said switching means, any one of claim 1 or 2, characterized in that from the switching valve is actuated by hydraulic pressure of hydraulic oil supplied to the frictional engagement element to be fastened at the specific shift speed 2. The hydraulic control device for an automatic transmission according to claim 1 . The hydraulic control device for an automatic transmission according to any one of claims 1 to 3 , wherein the specific shift speed at which the slip control of the lock-up clutch is performed includes a third speed and a fourth speed. . The hydraulic control device for an automatic transmission according to any one of claims 1 to 4 , wherein the electromagnetic solenoid valve comprises a three-way duty solenoid valve. The hydraulic control device for an automatic transmission according to any one of claims 1 to 4 , wherein the electromagnetic solenoid valve comprises a combination of a duty solenoid valve and a pressure regulating valve.

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