JP2004218714A

JP2004218714A - Electrically actuated brake device

Info

Publication number: JP2004218714A
Application number: JP2003006043A
Authority: JP
Inventors: Masahiro Imamachi; 真浩今町
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2003-01-14
Filing date: 2003-01-14
Publication date: 2004-08-05
Anticipated expiration: 2023-01-14
Also published as: JP3909021B2

Abstract

<P>PROBLEM TO BE SOLVED: To improve the responsibility when changing brake force in an electrically actuated brake device. <P>SOLUTION: The electrically actuated brake device consists of a brake piston 17 for moving a brake pad 19 in the direction of an axis L and a first and a second electric motors 36 and 37 connected via a screw mechanism 58. The screw mechanism 58 is provided with a first screw member 21 and a second screw member 28 engaged with each other. The first screw member 21 is rotatably supported with respect to a brake caliper 11, and jammed in the direction of the axis L. The second screw member 28 is relatively rotated with respect to the first screw member 21 so that the second screw member 28 is moved toward the direction of the axis L with the brake piston 17 and the brake pad 19. The brake pad 19 is made to approach, stop and detach only by changing the rotational speed with good responsibility with respect to a brake disk 14 so that the braking force can be controlled to increase, maintain and reduce without stopping or reversing the rotation of both screw members 21 and 28. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、ブレーキキャリパに設けた制動部材と電動モータとをねじ機構を介して接続し、電動モータの駆動力で制動部材を軸線方向に移動させて被制動部材に押し付けることでブレーキ力を発生させる電動ブレーキ装置に関する。
【０００２】
【従来の技術】
一般に従来のブレーキ装置は、ブレーキキャリパに設けたブレーキピストンをマスタシリンダや油圧ポンプで発生した油圧で駆動し、このブレーキピストンでブレーキパッドをブレーキディスクに押し付けてブレーキ力を発生させるようになっている。
【０００３】
ブレーキピストンを油圧で駆動する代わりに、電動モータが発生する回転力を減速機およびねじ機構で推力に変換してブレーキピストンを駆動するものが、下記特許文献により公知である。このブレーキ装置によれば、電動モータの回転方向を変化させてブレーキピストンを前進、停止および後退させることで、ブレーキ力を増加、保持および減少させることができる。
【０００４】
【特許文献】
特開平１１−３２１５９９号公報
【０００５】
【発明が解決しようとする課題】
ところで、上記特許文献に記載されたものは、電動モータの回転力を減速機で減速してねじ機構に伝達し、ねじ機構でピストンを駆動してブレーキ力を発生させるようになっているが、ブレーキ力を増加させるべく減速機の減速比を増加させると電動モータを駆動してからブレーキ力が立ち上がるまでの応答性が低下してしまう問題がある。またブレーキ力を短い時間間隔で増減させるアンチロックブレーキ制御を行う場合には、電動モータを慣性に抗して正転→停止→逆転→停止→正転…させる必要があり、そのために応答性が更に低下する問題がある。
【０００６】
本発明は前述の事情に鑑みてなされたもので、電動ブレーキ装置のブレーキ力を変化させる際の応答性を高めることを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、請求項１に記載された発明によれば、ブレーキキャリパに設けた制動部材と電動モータとをねじ機構を介して接続し、電動モータの駆動力で制動部材を軸線方向に移動させて被制動部材に押し付けることでブレーキ力を発生させる電動ブレーキ装置において、前記ねじ機構は雌ねじを有する第１ねじ部材と、それに噛み合う雄ねじを有する第２ねじ部材とを備え、第１、第２ねじ部材の一方のねじ部材をブレーキキャリパに対して回転可能かつ軸線方向移動不能に支持し、一方のねじ部材およびを他方のねじ部材を相対回転させることで、他方のねじ部材を制動部材と共に軸線方向に移動させることを特長とする電動ブレーキ装置が提案される。
【０００８】
上記構成によれば、第１ねじ部材の雌ねじと第２ねじ部材の雄ねじとを相互に噛み合わせ、一方のねじ部材をブレーキキャリパに対して回転可能かつ軸線方向移動不能に支持し、両ねじ部材を相対回転させて他方のねじ部材を制動部材と共に軸線方向に移動させることで、制動部材を被制動部材に押し付けてブレーキ力を発生させるので、両ねじ部材の回転を停止したり逆転したりすることなく、その回転数を変化させるだけで制動部材を被制動部材に対して応答性良く接近、停止および離反させてブレーキ力の増加、保持および減少を制御することができる。
【０００９】
また請求項２に記載された発明によれば、請求項１の構成に加えて、第１、第２ねじ部材の相対回転の大きさを設定する相対回転量設定手段を備えたことを特長とする電動ブレーキ装置が提案される。
【００１０】
上記構成によれば、相対回転量設定手段により第１、第２ねじ部材の相対回転の大きさを設定することで、第１ねじ部材に対する第２ねじ部材の移動方向および移動速度を変化させ、制動部材の移動方向、移動速度および移動荷重を任意に制御することができる。
【００１１】
また請求項３に記載された発明によれば、請求項２の構成に加えて、相対回転量設定手段は、第１ねじ部材を駆動する第１電動モータと、第２ねじ部材を駆動する第２電動モータとを含むことを特長とする電動ブレーキ装置が提案される。
【００１２】
上記構成によれば、相対回転量設定手段が第１ねじ部材を駆動する第１電動モータと、第２ねじ部材を駆動する第２電動モータとを含むので、第１、第２電動モータの回転数を変化させることで第１、第２ねじ部材の相対回転の大きさを任意に制御することができる。
【００１３】
また請求項４に記載された発明によれば、請求項２の構成に加えて、相対回転量設定手段は、単一の電動モータと、その電動モータの駆動力を第１、第２ねじ部材にそれぞれ伝達する第１、第２動力伝達経路と、第１、第２動力伝達経路の少なくとも一方に設けられた無段変速機とを含むことを特長とする電動ブレーキ装置が提案される。
【００１４】
上記構成によれば、相対回転量設定手段が単一の電動モータと、その電動モータの駆動力を第１、第２ねじ部材にそれぞれ伝達する第１、第２動力伝達経路と、第１、第２動力伝達経路の少なくとも一方に設けられた無段変速機とを含むので、電動モータの数を最小個数の１個に抑えながら、無段変速機の変速比を変化させることで第１、第２ねじ部材の相対回転の大きさを任意に制御することができる。
【００１５】
尚、実施例のブレーキディスク１４は本発明の被制動部材に対応し、実施例のブレーキパッド１９は本発明の制動部材に対応し、実施例の第１ねじ部材２１は本発明の一方のねじ部材に対応し、実施例の第２ねじ部材２８は本発明の他方のねじ部材に対応し、実施例の第１電動モータ３６および第２電動モータ３７は本発明の電動モータに対応する。
【００１６】
【発明の実施の形態】
以下、本発明の実施の形態を、添付図面に示した本発明の実施例に基づいて説明する。
【００１７】
図１および図２は本発明の第１実施例を示すもので、図１は電動ブレーキ装置の縦断面図、図２は図１の２部拡大図である。
【００１８】
電動ブレーキ装置のブレーキキャリパ１１は、車輪を回転自在に支持するナックル（図示せず）に支持される本体部１２と、本体部１２からブレーキディスク１４を跨いで反対側に延びる腕部１３とを備える。ブレーキキャリパ１１の腕部１３の内面にバックプレート１５を介して固定されたブレーキパッド１６と、ブレーキピストン１７にバックプレート１８を介して固定されたブレーキパッド１９とがブレーキディスク１４の両面に当接可能に対向しており、ブレーキピストン１７の周縁部がブーツ２０でブレーキキャリパ１１の本体部１２の内面に接続される。
【００１９】
ブレーキキャリパ１１の本体部１２に、軸線Ｌ方向に延びる大径の凹部１２ａと小径の貫通孔１２ｂとが同軸に形成されており、貫通孔１２ｂを筒状の第１ねじ部材２１の軸部２１ａが貫通する。第１ねじ部材２１の軸部２１ａに連なるフランジ２１ｂがブレーキキャリパ１１の凹部１２ａに収納されており、このフランジ２１ｂの一側面がボールベアリング２２およびリテーナ２３を介して本体部１２の段部１２ｃに支持され、他側面がボールベアリング２４、リテーナ２５およびスプリングワッシャ２６を介して、凹部１２ａの開口端に装着されたサークリップ２７に支持される。
【００２０】
軸線Ｌ上に配置された第１ねじ部材２１の内部に軸状の第２ねじ部材２８が同軸に嵌合し、第１ねじ部材２１の内周面に形成された雌ねじ２１ｃに第２ねじ部材２８の外周面に形成された雄ねじ２８ａが噛み合い、かつ第１ねじ部材２１の内周面および第２ねじ部材２８の外周面間にブッシュ２９が配置される。第２ねじ部材２８の先端に形成された半球状の頭部２８ｂがブレーキピストン１７の外面に形成された皿状の凹部１７ａに相対回転可能に当接し、第２ねじ部材２８の先端近傍に形成された環状溝２８ｃに、ブレーキピストン１７の外面に外周を固定された円環状のピストン戻しスプリング３０の折り返した内周面が相対回転可能に係合する。
【００２１】
ブレーキキャリパ１１の本体部１２にシール部材３１を介して第１ギヤハウジング３２を固定し、かつ第１ギヤハウジング３２にシール部材３３を介して第２ギヤハウジング３４を固定することで、第１、第２ギヤハウジング３２，３４の内部にギヤ室３５が形成される。第１ギヤハウジング３２の外部に第１電動モータ３６および第２電動モータ３７が固定されており、第２ギヤハウジング３４にボールベアリング３８で支持された第１電動モータ３６の出力軸３９に第１ギヤ４０が設けられ、第２ギヤハウジング３４にボールベアリング４１で支持された第２電動モータ３７の出力軸４２に第５ギヤ４３が設けられる。
【００２２】
第１、第２ギヤハウジング３２，３４にボールベアリング４４，４５を介して支持された中間軸４６に第２ギヤ４７および第３ギヤ４８が設けられており、第２ギヤ４７は前記第１ギヤ４０に噛み合い、第３ギヤ４８は第１ねじ部材２１に設けた第４ギヤ４９に噛み合っている。第１、第２ギヤハウジング３２，３４にボールベアリング５０，５１を介して支持された中間軸５２に第６ギヤ５３および第７ギヤ５４が設けられており、第６ギヤ５３は前記第５ギヤ４３に噛み合い、第７ギヤ５４は第２ねじ部材２８に設けた第８ギヤ５５に噛み合っている。第７ギヤ５４は軸線Ｌ方向に長く形成されており、第８ギヤ５５は第７ギヤ５４に対して軸線Ｌ方向に移動可能である。
【００２３】
尚、第２ギヤハウジング３４にボールベアリング５６を介して支持されたガイド軸５７を、第２ねじ部材２８の軸端に開口するガイド孔２８ｄに摺動自在に嵌合させることで、第２ねじ部材２８の振れを防止しながら、その軸線Ｌ方向の移動を許容することができる。ガイド軸５７は第２ギヤハウジング３４に固定することもできる。
【００２４】
また第１ねじ部材２１および第２ねじ部材２８はねじ機構５８を構成し、第１電動モータ３６、第２電動モータ３７および第１ギヤ〜第８ギヤ４０，４７，４８，４９，４３，５３，５４，５５は相対回転量設定手段５９を構成する。
【００２５】
次に、上記構成を備えた第１実施例の作用を説明する。
【００２６】
第１電動モータ３６を駆動すると、その出力軸３９の回転は第１ギヤ〜第４ギヤ４０，４７，４８，４９で減速されて第１ねじ部材２１を回転させる。これと同時に第２電動モータ３７を駆動すると、その出力軸４２の回転は第５ギヤ〜第８ギヤ４３，５３，５４，５５で減速されて第２ねじ部材２８を回転させる。このとき、ねじ機構５８を構成する第１、第２ねじ部材２１，２８が同速度で同方向に回転するように第１、第２電動モータ３６，３７を制御すると、相互に噛み合う第１ねじ部材２１の雌ねじ２１ｃと第２ねじ部材２８の雄ねじ２８ａとの間に相対回転が発生しないため、第２ねじ部材２８は第１ねじ部材２１に対して軸線Ｌ方向に移動することはない。その結果、第２ねじ部材２８はブレーキピストン１７を押しも引きもせず、ブレーキパッド１６，１９とブレーキディスク１４との間の面圧が解除されたままで電動ブレーキ装置は非制動状態になる。
【００２７】
この状態から第１電動モータ３６の回転数を増加させ、第２電動モータ３７の回転数を減少させると、第１ねじ部材２１の回転数＞第２ねじ部材２８の回転数となり、第１ねじ部材２１に対して第２ねじ部材２８が図中左方向に相対移動してブレーキピストン１７を押圧する。その結果、両ブレーキパッド１６，１９がブレーキディスク１４の両面を挟み付け、その摺動面に発生する摩擦力で車輪が制動される。電動ブレーキ装置が発生するブレーキ力は、第１ねじ部材２１に対する第２ねじ部材２８の図中左方向への相対移動量が増加するに応じて増加する。
【００２８】
所定のブレーキ力が得られたときに、第１、第２電動モータ３６，３７の回転数を元に戻して第１、第２ねじ部材２１，２８の回転数を一致させると、ブレーキピストン１７がその位置に停止してブレーキ力が保持される。また第１電動モータ３６の回転数を減少させ、第２電動モータ３７の回転数を増加させると、第１ねじ部材２１の回転数＜第２ねじ部材２８の回転数となり、第１ねじ部材２１に対して第２ねじ部材２８が図中右方向に相対移動する。その結果、ピストン戻しスプリング３０を介してブレーキピストン１７が第２ねじ部材２８に追従するように図中右方向に移動することで、両ブレーキパッド１６，１９がブレーキディスク１４の両面から離反してブレーキ力が減少する。
【００２９】
第２ねじ部材２８が軸線Ｌ方向に進退するとき、それと一体の第８ギヤ５５も進退するが、第８ギヤ５５に噛み合う第７ギヤ５４は軸線Ｌ方向に長く形成されているので、第２ねじ部材２８の進退が阻害されることはない。同様の理由で、両ブレーキパッド１６，１９の摩耗に伴う第２ねじ部材２８の前進にも対応することができる。また回転する第２ねじ部材２８の半球状の頭部２８ｂと、回転しないブレーキピストン１７の皿状の凹部１７ａとは点接触するため、接触部の摩擦抵抗を最小限に抑えることができる。
【００３０】
以上のように、ブレーキ力の増加（ブレーキピストン１７の前進）、ブレーキ力の保持（ブレーキピストン１７の停止）およびブレーキ力の減少（ブレーキピストン１７の後退）を切り換える際に、第１、第２電動モータ３６，３７を停止あるいは逆転させる必要がなく、それらの回転数を増減するだけで良いため、ブレーキ力を応答性良く制御することができる。
【００３１】
また第１、第２ねじ部材２１，２８の回転数差を小さくすれば、第１、第２電動モータ３６，３７から第１、第２ねじ部材２１，２８への動力伝達経路の減速比を大きくしたのと同じ効果が得られ、ブレーキピストン１７を大きな荷重で前進させて大きなブレーキ力を発生させることができる。逆に、第１、第２ねじ部材２１，２８の回転数差を大きくすれば、第１、第２電動モータ３６，３７から第１、第２ねじ部材２１，２８への動力伝達経路の減速比を小さくしたのと同じ効果が得られ、ブレーキピストン１７を速い速度で進退させて応答性を更に高めることができる。
【００３２】
従って、制動初期のブレーキパッド１６，１９がブレーキディスク１４に当接する前には、第１、第２ねじ部材２１，２８の回転数差を大きくして第２ねじ部材２８を素早く前進させ、ブレーキパッド１６，１９がブレーキディスク１４に当接した後には、第１、第２ねじ部材２１，２８の回転数差を小さくして第２ねじ部材２８を大きな荷重で前進させることで、高い応答性および大きなブレーキ力を両立させることができる。
【００３３】
図３〜図５は本発明の第２実施例を示すもので、図３は電動ブレーキ装置の縦断面図、図４は図３の４部拡大図、図５は図４の５−５線断面図である。尚、第２実施例において、第１実施例の構成要素に対応する構成要素に、第１実施例の符号と同じ符号を付すことで重複する説明を省略する。
【００３４】
第１実施例は第１、第２電動モータ３６，３７を備えているが、第２実施例は単一の電動モータ６１のみを備えている。電動モータ６１の駆動力は２分割され、その一方は第１動力伝達経路６２を介して第１ねじ部材２１に伝達され、もう一方は第２動力伝達経路６３を介して第２ねじ部材２８に伝達される。
【００３５】
第１動力伝達経路６２は無段変速機６４と、第１ギヤハウジング３２にボールベアリング６５で支持した第２中間軸６６に設けられた第３ギヤ６７と、第１ねじ部材２１に設けられた第４ギヤ６８とで構成される。無段変速機６４は、第２ギヤハウジング３４にボールベアリング６９で支持した電動モータ６１の出力軸７０に設けられたドライブディスク７１と、出力軸７０と直交する第１中間軸７２により回転自在に支持されたドリブンディスク７３と、ドライブディスク７１の円弧面およびドリブンディスク７３の円弧面に同時に当接する変速ローラ７４とを備える。そしてドリブンディスク７３の背面に一体に形成された第１ギヤ７５が、第２中間軸６６に設けられた第２ギヤ７６に噛み合っている。
【００３６】
変速ローラ７４は枠状のローラハウジング７７に支軸７８およびボールベアリング７９，７９を介して回転自在に支持されており、ローラハウジング７７は出力軸７０および第１中間軸７２の成す平面に直交する支軸８０，８０を介して第２ギヤハウジング３４に回転自在に支持される。ローラハウジング７７に固定したアーム部材８１の先端に形成された長孔８１ａに、ソレノイド８２の出力ロッド８３に設けられたピン８４が係合する。
【００３７】
第２動力伝達経路６３は電動モータ６１の出力軸７０に設けられた第５ギヤ８５と、第２ギヤハウジング３４にボールベアリング８６を介して支持した第３中間軸８７に設けられた第６ギヤ８８と、第２ねじ部材２８に設けられた第７ギヤ８９とで構成される。第２ギヤハウジング３４にボールベアリング９０を介して支持されたガイド軸９１を、第２ねじ部材２８の軸端に開口するガイド孔２８ｄに摺動自在に嵌合させることで、第２ねじ部材２８の振れを防止しながら、その軸線Ｌ方向の移動を許容することができる。
【００３８】
尚、電動モータ６１、無段変速機６４および第１ギヤ〜第７ギヤ７５，７６，６７，６８，８５，８８，８９は相対回転量設定手段５９を構成する。
【００３９】
次に、上記構成を備えた第２実施例の作用を説明する。
【００４０】
電動モータ６１を一定速度で一定方向に回転駆動すると、その出力軸７０の回転は第１動力伝達経路６２および第２動力伝達経路６３にそれぞれ伝達される。第１動力伝達経路６２では、出力軸７０の回転がドライブディスク７１、変速ローラ７４、ドリブンディスク７３、第１ギヤ７５、第２ギヤ７６、第３ギヤ６７および第４ギヤ６８を介して第１ねじ部材２１に伝達され、第２動力伝達経路６３では出力軸７０の回転が第５ギヤ８５、第６ギヤ８８および第７ギヤ８９を介して第２ねじ部材２８に伝達される。
【００４１】
無段変速機６４の変速比が所定の変速比（ニュートラル）であれば、第１、第２ねじ部材２１，２８は同速度で同方向に回転し、相互に噛み合う第１ねじ部材２１の雌ねじ２１ｃと第２ねじ部材２８の雄ねじ２８ａとの間に相対回転が発生しないため、第２ねじ部材２８は第１ねじ部材２１に対して軸線Ｌ方向に移動することはない。その結果、第２ねじ部材２８はブレーキピストン１７を押しも引きもせず、ブレーキパッド１６，１９とブレーキディスク１４との間の面圧が解除されて電動ブレーキ装置は非制動状態になる。
【００４２】
この状態から無段変速機６４のソレノイド８２の出力ロッド８３を伸長すると、図４において変速ローラ７４が支軸８０回りに矢印ａ方向に回転し、ドライブディスク７１と変速ローラ７４との接触部の有効半径が増加し、ドリブンディスク７３と変速ローラ７４との接触部の有効半径が減少することで、無段変速機６４の変速比が減少して第１ねじ部材２１の回転数が増加する。一方、第２ねじ部材２８の回転数は変化しないため、第１ねじ部材２１の回転数＞第２ねじ部材２８の回転数となり、第１ねじ部材２１に対して第２ねじ部材２８が図中左方向に相対移動してブレーキピストン１７を押圧する。その結果、両ブレーキパッド１６，１９がブレーキディスク１４の両面を挟み付け、その摺動面に発生する摩擦力で車輪が制動される。電動ブレーキ装置が発生するブレーキ力は、第１ねじ部材２１に対する第２ねじ部材２８の図中左方向への相対移動量が増加するに応じて増加する。
【００４３】
所定のブレーキ力が得られたときに、ソレノイド８２で変速ローラ７４をニュートラル位置に戻すと、ブレーキピストン１７がその位置に停止してブレーキ力が保持される。また無段変速機６４のソレノイド８２の出力ロッド８３を収縮すると、図４において変速ローラ７４が支軸８０回りに矢印ｂ方向に回転し、ドライブディスク７１と変速ローラ７４との接触部の有効半径が減少し、ドリブンディスク７３と変速ローラ７４との接触部の有効半径が増加することで、無段変速機６４の変速比が増加して第１ねじ部材２１の回転数が減少する。一方、第２ねじ部材２８の回転数は変化しないため、第１ねじ部材２１の回転数＜第２ねじ部材２８の回転数となり、第１ねじ部材２１に対して第２ねじ部材２８が図中右方向に相対移動する。その結果、ピストン戻しスプリング３０を介してブレーキピストン１７が第２ねじ部材２８に追従するように図中右方向に移動することで、両ブレーキパッド１６，１９がブレーキディスク１４の両面から離反してブレーキ力が減少する。
【００４４】
以上のように、ブレーキ力の増加（ブレーキピストン１７の前進）、ブレーキ力の保持（ブレーキピストン１７の停止）およびブレーキ力の減少（ブレーキピストン１７の後退）を切り換える際に、電動モータ６１を停止あるいは逆転させる必要がなく、第１動力伝達経路６２に配置した無段変速機６４の変速比を変更するだけで良いため、ブレーキ力を応答性良く制御することができる。
【００４５】
また変速ローラ７４を小角度揺動させて回転数差を小さくすれば、第１、第２ねじ部材２１，２８の相対回転数を小さくしてブレーキピストン１７を大きな荷重でゆっくりと前進させ、大きなブレーキ力を発生させることができる。逆に、変速ローラ７４を大角度揺動させて第１、第２ねじ部材２１，２８の回転数差を大きくすれば、第１、第２ねじ部材２１，２８の相対回転数を大きくしてブレーキピストン１７を小さな荷重で素早く進退させ、応答性を高めることができる。
【００４６】
従って、制動初期のブレーキパッド１６，１９がブレーキディスク１４に当接する前には、第１、第２ねじ部材２１，２８の回転数差を大きくして第２ねじ部材２８を素早く前進させ、ブレーキパッド１６，１９がブレーキディスク１４に当接した後には、第１、第２ねじ部材２１，２８の回転数差を小さくして第２ねじ部材２８を大きな荷重で前進させることで、高い応答性および大きなブレーキ力を両立させることができる。
【００４７】
以上、本発明の実施例を説明したが、本発明はその要旨を逸脱しない範囲で種々の設計変更を行うことが可能である。
【００４８】
例えば、実施例では第１ねじ部材２１を軸線Ｌ方向に移動不能に設け、第２ねじ部材２８を軸線Ｌ方向に移動可能に設けているが、その関係を逆にして第１ねじ部材２１でブレーキピストン１７を駆動しても良い。
【００４９】
また実施例では無段変速機６４を第１動力伝達経路６２に設けているが、それを第２動力伝達経路６３に設けてたり、第１、第２動力伝達経路６２，６３の両方に設けたりすることができる。
【００５０】
また無段変速機６４は実施例のものに限定されず、任意の構造のものを採用することができる。
【００５１】
【発明の効果】
以上のように請求項１に記載された発明によれば、第１ねじ部材の雌ねじと第２ねじ部材の雄ねじとを相互に噛み合わせ、一方のねじ部材をブレーキキャリパに対して回転可能かつ軸線方向移動不能に支持し、両ねじ部材を相対回転させて他方のねじ部材を制動部材と共に軸線方向に移動させることで、制動部材を被制動部材に押し付けてブレーキ力を発生させるので、両ねじ部材の回転を停止したり逆転したりすることなく、その回転数を変化させるだけで制動部材を被制動部材に対して応答性良く接近、停止および離反させてブレーキ力の増加、保持および減少を制御することができる。
【００５２】
また請求項２に記載された発明によれば、相対回転量設定手段により第１、第２ねじ部材の相対回転の大きさを設定することで、第１ねじ部材に対する第２ねじ部材の移動方向および移動速度を変化させ、制動部材の移動方向、移動速度および移動荷重を任意に制御することができる。
【００５３】
また請求項３に記載された発明によれば、相対回転量設定手段が第１ねじ部材を駆動する第１電動モータと、第２ねじ部材を駆動する第２電動モータとを含むので、第１、第２電動モータの回転数を変化させることで第１、第２ねじ部材の相対回転の大きさを任意に制御することができる。
【００５４】
また請求項４に記載された発明によれば、相対回転量設定手段が単一の電動モータと、その電動モータの駆動力を第１、第２ねじ部材にそれぞれ伝達する第１、第２動力伝達経路と、第１、第２動力伝達経路の少なくとも一方に設けられた無段変速機とを含むので、電動モータの数を最小個数の１個に抑えながら、無段変速機の変速比を変化させることで第１、第２ねじ部材の相対回転の大きさを任意に制御することができる。
【図面の簡単な説明】
【図１】第１実施例の電動ブレーキ装置の縦断面図
【図２】図１の２部拡大図
【図３】第２実施例の電動ブレーキ装置の縦断面図
【図４】図３の４部拡大図
【図５】図４の５−５線断面図
【符号の説明】
１１ブレーキキャリパ
１４ブレーキディスク（被制動部材）
１９ブレーキパッド（制動部材）
２１第１ねじ部材（一方のねじ部材）
２１ｃ雌ねじ
２８第２ねじ部材（他方のねじ部材）
２８ａ雄ねじ
３６第１電動モータ（電動モータ）
３７第２電動モータ（電動モータ）
５８ねじ機構
５９相対回転量設定手段
６１電動モータ
６２第１動力伝達経路
６３第２動力伝達経路
Ｌ軸線[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a braking force is generated by connecting a braking member provided on a brake caliper and an electric motor via a screw mechanism, moving the braking member in the axial direction by the driving force of the electric motor, and pressing the braking member against the member to be braked. The present invention relates to an electric brake device to be driven.
[0002]
[Prior art]
Generally, in a conventional brake device, a brake piston provided in a brake caliper is driven by hydraulic pressure generated by a master cylinder or a hydraulic pump, and a brake pad is pressed against a brake disk by the brake piston to generate a braking force. .
[0003]
Japanese Patent Application Laid-Open No. H11-163873 discloses a technique in which a rotational force generated by an electric motor is converted into a thrust by a speed reducer and a screw mechanism to drive a brake piston instead of driving a brake piston by hydraulic pressure. According to this brake device, the braking force can be increased, held, and reduced by changing the rotation direction of the electric motor to advance, stop, and retreat the brake piston.
[0004]
[Patent Document]
JP-A-11-321599
[Problems to be solved by the invention]
By the way, what is described in the above-mentioned patent document is such that the torque of the electric motor is reduced by a speed reducer and transmitted to a screw mechanism, and a piston is driven by the screw mechanism to generate a braking force. If the reduction ratio of the speed reducer is increased to increase the braking force, there is a problem that the responsiveness from driving the electric motor until the braking force rises is reduced. In addition, when performing antilock brake control for increasing or decreasing the braking force at short time intervals, the electric motor needs to be rotated in a forward direction, a stop, a reverse rotation, a stop, a forward rotation, etc. against the inertia. There is a further problem of deterioration.
[0006]
The present invention has been made in view of the above circumstances, and has as its object to enhance the responsiveness when changing the braking force of an electric brake device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the braking member provided on the brake caliper is connected to the electric motor via a screw mechanism, and the braking member is driven by the driving force of the electric motor so that the braking member is moved along the axis. In the electric brake device that generates a braking force by moving in a direction and pressing against a member to be braked, the screw mechanism includes a first screw member having a female screw and a second screw member having a male screw engaged with the first screw member. By supporting one screw member of the second screw member so as to be rotatable and immovable in the axial direction with respect to the brake caliper and braking the other screw member by rotating the one screw member and the other screw member relative to each other. An electric brake device characterized by being moved in the axial direction together with a member is proposed.
[0008]
According to the above configuration, the female screw of the first screw member and the male screw of the second screw member are engaged with each other, and one of the screw members is rotatably supported on the brake caliper so as not to move in the axial direction. Is relatively rotated to move the other screw member in the axial direction together with the braking member, so that the braking member is pressed against the member to be braked to generate a braking force, so that the rotation of the two screw members is stopped or reversed. Without increasing the number of rotations, the braking member can approach, stop, and separate from the member to be braked with good responsiveness to control the increase, holding, and reduction of the braking force.
[0009]
According to the second aspect of the present invention, in addition to the configuration of the first aspect, a relative rotation amount setting means for setting a relative rotation amount of the first and second screw members is provided. An electric brake device is proposed.
[0010]
According to the above configuration, the relative rotation amount setting means sets the magnitude of the relative rotation of the first and second screw members, thereby changing the moving direction and the moving speed of the second screw member with respect to the first screw member, The moving direction, moving speed and moving load of the braking member can be arbitrarily controlled.
[0011]
According to the third aspect of the present invention, in addition to the configuration of the second aspect, the relative rotation amount setting means includes a first electric motor that drives the first screw member and a second electric motor that drives the second screw member. An electric brake device characterized by including two electric motors is proposed.
[0012]
According to the above configuration, since the relative rotation amount setting unit includes the first electric motor that drives the first screw member and the second electric motor that drives the second screw member, rotation of the first and second electric motors is performed. By changing the number, the magnitude of the relative rotation of the first and second screw members can be arbitrarily controlled.
[0013]
According to the fourth aspect of the present invention, in addition to the configuration of the second aspect, the relative rotation amount setting means includes a single electric motor and a driving force of the electric motor, the first and second screw members. And a continuously variable transmission provided on at least one of the first and second power transmission paths.
[0014]
According to the above configuration, the relative rotation amount setting means includes a single electric motor, and first and second power transmission paths for transmitting the driving force of the electric motor to the first and second screw members, respectively. And a continuously variable transmission provided on at least one of the second power transmission paths, so that the number of electric motors is reduced to a minimum of one and the speed ratio of the continuously variable transmission is changed. The magnitude of the relative rotation of the second screw member can be arbitrarily controlled.
[0015]
The brake disk 14 of the embodiment corresponds to the member to be braked of the present invention, the brake pad 19 of the embodiment corresponds to the braking member of the present invention, and the first screw member 21 of the embodiment corresponds to one screw of the present invention. The second screw member 28 of the embodiment corresponds to the other screw member of the present invention, and the first electric motor 36 and the second electric motor 37 of the embodiment correspond to the electric motor of the present invention.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.
[0017]
1 and 2 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an electric brake device, and FIG. 2 is an enlarged view of a part of FIG.
[0018]
A brake caliper 11 of the electric brake device includes a main body 12 supported by a knuckle (not shown) that rotatably supports wheels, and an arm 13 extending from the main body 12 to the opposite side across the brake disk 14. Prepare. A brake pad 16 fixed to the inner surface of the arm 13 of the brake caliper 11 via the back plate 15 and a brake pad 19 fixed to the brake piston 17 via the back plate 18 abut on both surfaces of the brake disc 14. The periphery of the brake piston 17 is connected to the inner surface of the main body 12 of the brake caliper 11 by the boot 20.
[0019]
A large-diameter concave portion 12a and a small-diameter through hole 12b extending in the direction of the axis L are formed coaxially in the main body 12 of the brake caliper 11, and the through hole 12b is formed in the shaft portion 21a of the cylindrical first screw member 21. Penetrates. A flange 21b connected to the shaft portion 21a of the first screw member 21 is housed in the concave portion 12a of the brake caliper 11, and one side surface of the flange 21b is connected to the step portion 12c of the main body portion 12 via the ball bearing 22 and the retainer 23. The other side is supported by a circlip 27 attached to the open end of the recess 12 a via a ball bearing 24, a retainer 25 and a spring washer 26.
[0020]
An axial second screw member 28 is coaxially fitted inside the first screw member 21 disposed on the axis L, and a second screw member is formed on a female screw 21 c formed on the inner peripheral surface of the first screw member 21. A male screw 28a formed on the outer peripheral surface of the second screw member 28 meshes with the male screw 28a, and a bush 29 is disposed between the inner peripheral surface of the first screw member 21 and the outer peripheral surface of the second screw member 28. A hemispherical head 28b formed at the tip of the second screw member 28 relatively rotatably abuts a dish-shaped recess 17a formed on the outer surface of the brake piston 17, and is formed near the tip of the second screw member 28. The folded inner circumferential surface of an annular piston return spring 30 whose outer circumference is fixed to the outer surface of the brake piston 17 is rotatably engaged with the formed annular groove 28c.
[0021]
By fixing the first gear housing 32 to the main body 12 of the brake caliper 11 via the seal member 31 and fixing the second gear housing 34 to the first gear housing 32 via the seal member 33, A gear chamber 35 is formed inside the second gear housings 32 and 34. A first electric motor 36 and a second electric motor 37 are fixed to the outside of the first gear housing 32, and the first electric motor 36 is supported by a ball bearing 38 on the second gear housing 34, and the first electric motor 36 has an output shaft 39. A gear 40 is provided, and a fifth gear 43 is provided on an output shaft 42 of the second electric motor 37 supported by the second gear housing 34 with a ball bearing 41.
[0022]
A second gear 47 and a third gear 48 are provided on an intermediate shaft 46 supported by first and second gear housings 32, 34 via ball bearings 44, 45, and the second gear 47 is the first gear. The third gear 48 meshes with a fourth gear 49 provided on the first screw member 21. A sixth gear 53 and a seventh gear 54 are provided on an intermediate shaft 52 supported by first and second gear housings 32, 34 via ball bearings 50, 51, and the sixth gear 53 is the fifth gear. The third gear 54 meshes with the eighth gear 55 provided on the second screw member 28. The seventh gear 54 is formed long in the direction of the axis L, and the eighth gear 55 is movable in the direction of the axis L with respect to the seventh gear 54.
[0023]
The guide shaft 57 supported by the second gear housing 34 via a ball bearing 56 is slidably fitted in a guide hole 28d opened at the shaft end of the second screw member 28, whereby the second screw The movement of the member 28 in the direction of the axis L can be allowed while preventing the member 28 from swinging. The guide shaft 57 can be fixed to the second gear housing 34.
[0024]
The first screw member 21 and the second screw member 28 constitute a screw mechanism 58, and include the first electric motor 36, the second electric motor 37, and the first to eighth gears 40, 47, 48, 49, 43, 53. , 54 and 55 constitute a relative rotation amount setting means 59.
[0025]
Next, the operation of the first embodiment having the above configuration will be described.
[0026]
When the first electric motor 36 is driven, the rotation of the output shaft 39 is reduced by the first to fourth gears 40, 47, 48, and 49 to rotate the first screw member 21. At the same time, when the second electric motor 37 is driven, the rotation of the output shaft 42 is reduced by the fifth to eighth gears 43, 53, 54, 55 to rotate the second screw member 28. At this time, when the first and second electric motors 36 and 37 are controlled such that the first and second screw members 21 and 28 constituting the screw mechanism 58 rotate in the same direction at the same speed, the first screw meshing with each other is achieved. Since no relative rotation occurs between the female screw 21c of the member 21 and the male screw 28a of the second screw member 28, the second screw member 28 does not move in the direction of the axis L with respect to the first screw member 21. As a result, the second screw member 28 does not push or pull the brake piston 17, and the electric brake device is in a non-braking state with the surface pressure between the brake pads 16, 19 and the brake disc 14 being released.
[0027]
From this state, when the rotation speed of the first electric motor 36 is increased and the rotation speed of the second electric motor 37 is reduced, the rotation speed of the first screw member 21> the rotation speed of the second screw member 28, and the first screw The second screw member 28 moves relative to the member 21 to the left in the drawing to press the brake piston 17. As a result, both brake pads 16 and 19 sandwich both surfaces of the brake disk 14, and the wheels are braked by the frictional force generated on the sliding surface. The braking force generated by the electric brake device increases as the amount of relative movement of the second screw member 28 to the first screw member 21 to the left in the drawing increases.
[0028]
When a predetermined braking force is obtained, when the rotation speeds of the first and second electric motors 36 and 37 are returned to the original and the rotation speeds of the first and second screw members 21 and 28 are made equal, the brake piston 17 Stops at that position and the braking force is maintained. When the rotation speed of the first electric motor 36 is decreased and the rotation speed of the second electric motor 37 is increased, the rotation speed of the first screw member 21 <the rotation speed of the second screw member 28, and the first screw member 21 The second screw member 28 relatively moves to the right in the drawing. As a result, when the brake piston 17 moves rightward in the drawing so as to follow the second screw member 28 via the piston return spring 30, the brake pads 16 and 19 separate from both surfaces of the brake disk 14. Braking force decreases.
[0029]
When the second screw member 28 advances and retreats in the direction of the axis L, the eighth gear 55 integral therewith also advances and retreats. However, since the seventh gear 54 meshing with the eighth gear 55 is formed longer in the direction of the axis L, The advance / retreat of the screw member 28 is not hindered. For the same reason, it is possible to cope with the advance of the second screw member 28 due to the wear of the brake pads 16 and 19. Further, since the hemispherical head portion 28b of the rotating second screw member 28 and the dish-shaped recess 17a of the non-rotating brake piston 17 make point contact, the frictional resistance of the contact portion can be minimized.
[0030]
As described above, when switching between increasing the braking force (forward movement of the brake piston 17), maintaining the braking force (stopping the brake piston 17), and decreasing the braking force (retreating the brake piston 17), the first and second braking operations are performed. It is not necessary to stop or reverse the electric motors 36 and 37, and it is only necessary to increase or decrease the number of rotations thereof, so that the braking force can be controlled with good responsiveness.
[0031]
Also, if the difference between the rotation speeds of the first and second screw members 21 and 28 is reduced, the reduction ratio of the power transmission path from the first and second electric motors 36 and 37 to the first and second screw members 21 and 28 can be reduced. The same effect as the increase can be obtained, and the brake piston 17 can be advanced with a large load to generate a large braking force. Conversely, if the rotational speed difference between the first and second screw members 21 and 28 is increased, the power transmission path from the first and second electric motors 36 and 37 to the first and second screw members 21 and 28 is reduced. The same effect as when the ratio is reduced is obtained, and the responsiveness can be further improved by moving the brake piston 17 at a high speed.
[0032]
Therefore, before the brake pads 16 and 19 at the initial stage of braking come into contact with the brake disk 14, the rotational speed difference between the first and second screw members 21 and 28 is increased to quickly advance the second screw member 28, and After the pads 16 and 19 come into contact with the brake disc 14, the difference between the rotation speeds of the first and second screw members 21 and 28 is reduced and the second screw member 28 is advanced with a large load, so that high responsiveness is achieved. And a large braking force.
[0033]
3 to 5 show a second embodiment of the present invention. FIG. 3 is a longitudinal sectional view of the electric brake device, FIG. 4 is an enlarged view of a part 4 in FIG. 3, and FIG. 5 is a line 5-5 in FIG. It is sectional drawing. In the second embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and redundant description is omitted.
[0034]
The first embodiment includes first and second electric motors 36 and 37, whereas the second embodiment includes only a single electric motor 61. The driving force of the electric motor 61 is divided into two, one of which is transmitted to the first screw member 21 via the first power transmission path 62 and the other of which is transmitted to the second screw member 28 via the second power transmission path 63. Is transmitted.
[0035]
The first power transmission path 62 is provided on the continuously variable transmission 64, the third gear 67 provided on the second intermediate shaft 66 supported by the first gear housing 32 by the ball bearing 65, and provided on the first screw member 21. And a fourth gear 68. The continuously variable transmission 64 is rotatable by a drive disk 71 provided on an output shaft 70 of an electric motor 61 supported by a ball bearing 69 in a second gear housing 34 and a first intermediate shaft 72 orthogonal to the output shaft 70. The driven disk 73 is supported, and the speed change roller 74 is simultaneously in contact with the arc surface of the drive disk 71 and the arc surface of the driven disk 73. A first gear 75 integrally formed on the back surface of the driven disk 73 meshes with a second gear 76 provided on the second intermediate shaft 66.
[0036]
The speed change roller 74 is rotatably supported by a frame-shaped roller housing 77 via a support shaft 78 and ball bearings 79, 79, and the roller housing 77 is orthogonal to a plane formed by the output shaft 70 and the first intermediate shaft 72. It is rotatably supported by the second gear housing 34 via the support shafts 80, 80. A pin 84 provided on an output rod 83 of a solenoid 82 is engaged with a long hole 81 a formed at the tip of an arm member 81 fixed to the roller housing 77.
[0037]
The second power transmission path 63 includes a fifth gear 85 provided on the output shaft 70 of the electric motor 61 and a sixth gear provided on a third intermediate shaft 87 supported on the second gear housing 34 via a ball bearing 86. 88 and a seventh gear 89 provided on the second screw member 28. A guide shaft 91 supported by the second gear housing 34 via a ball bearing 90 is slidably fitted in a guide hole 28d opened at the shaft end of the second screw member 28, so that the second screw member 28 The movement in the direction of the axis L can be permitted while preventing the deflection of the shaft.
[0038]
The electric motor 61, the continuously variable transmission 64, and the first to seventh gears 75, 76, 67, 68, 85, 88, 89 constitute relative rotation amount setting means 59.
[0039]
Next, the operation of the second embodiment having the above configuration will be described.
[0040]
When the electric motor 61 is driven to rotate at a constant speed in a constant direction, the rotation of the output shaft 70 is transmitted to the first power transmission path 62 and the second power transmission path 63, respectively. In the first power transmission path 62, the rotation of the output shaft 70 is transmitted through the drive disk 71, the speed change roller 74, the driven disk 73, the first gear 75, the second gear 76, the third gear 67, and the fourth gear 68 to the first gear. The rotation of the output shaft 70 is transmitted to the second screw member 28 via the fifth gear 85, the sixth gear 88, and the seventh gear 89 in the second power transmission path 63.
[0041]
If the speed ratio of the continuously variable transmission 64 is a predetermined speed ratio (neutral), the first and second screw members 21 and 28 rotate in the same direction at the same speed, and the female screw of the first screw member 21 meshing with each other. Since no relative rotation occurs between 21c and the external thread 28a of the second screw member 28, the second screw member 28 does not move in the direction of the axis L with respect to the first screw member 21. As a result, the second screw member 28 does not push or pull the brake piston 17, the surface pressure between the brake pads 16, 19 and the brake disk 14 is released, and the electric brake device is brought into a non-braking state.
[0042]
When the output rod 83 of the solenoid 82 of the continuously variable transmission 64 is extended from this state, the transmission roller 74 rotates in the direction of arrow a around the support shaft 80 in FIG. Since the effective radius increases and the effective radius of the contact portion between the driven disk 73 and the speed change roller 74 decreases, the speed ratio of the continuously variable transmission 64 decreases, and the rotation speed of the first screw member 21 increases. On the other hand, since the rotation speed of the second screw member 28 does not change, the rotation speed of the first screw member 21 is larger than the rotation speed of the second screw member 28, and the second screw member 28 with respect to the first screw member 21 in FIG. It moves relatively to the left and presses the brake piston 17. As a result, both brake pads 16 and 19 sandwich both surfaces of the brake disk 14, and the wheels are braked by the frictional force generated on the sliding surface. The braking force generated by the electric brake device increases as the amount of relative movement of the second screw member 28 to the first screw member 21 to the left in the drawing increases.
[0043]
When the shift roller 74 is returned to the neutral position by the solenoid 82 when a predetermined braking force is obtained, the brake piston 17 stops at that position and the braking force is held. When the output rod 83 of the solenoid 82 of the continuously variable transmission 64 is contracted, the transmission roller 74 rotates in the direction of the arrow b around the support shaft 80 in FIG. 4, and the effective radius of the contact portion between the drive disk 71 and the transmission roller 74. Is reduced, and the effective radius of the contact portion between the driven disk 73 and the speed change roller 74 is increased, so that the speed ratio of the continuously variable transmission 64 is increased, and the rotation speed of the first screw member 21 is reduced. On the other hand, since the rotation speed of the second screw member 28 does not change, the rotation speed of the first screw member 21 <the rotation speed of the second screw member 28, and the second screw member 28 with respect to the first screw member 21 in FIG. Move relatively to the right. As a result, when the brake piston 17 moves rightward in the drawing so as to follow the second screw member 28 via the piston return spring 30, the brake pads 16 and 19 separate from both surfaces of the brake disk 14. Braking force decreases.
[0044]
As described above, when switching between increasing the braking force (forward movement of the brake piston 17), maintaining the braking force (stopping the brake piston 17), and decreasing the braking force (retreating the brake piston 17), the electric motor 61 is stopped. Alternatively, it is not necessary to reverse the rotation, and only the gear ratio of the continuously variable transmission 64 arranged in the first power transmission path 62 needs to be changed, so that the braking force can be controlled with good responsiveness.
[0045]
If the speed difference roller 74 is oscillated by a small angle to reduce the rotational speed difference, the relative rotational speeds of the first and second screw members 21 and 28 are reduced, and the brake piston 17 is slowly advanced with a large load, thereby increasing the speed. A braking force can be generated. Conversely, if the speed change roller 74 is swung by a large angle to increase the rotation speed difference between the first and second screw members 21 and 28, the relative rotation speed of the first and second screw members 21 and 28 is increased. The brake piston 17 can be quickly moved back and forth with a small load, and the responsiveness can be improved.
[0046]
Therefore, before the brake pads 16 and 19 at the initial stage of braking come into contact with the brake disk 14, the rotational speed difference between the first and second screw members 21 and 28 is increased to quickly advance the second screw member 28, and After the pads 16 and 19 come into contact with the brake disc 14, the difference between the rotation speeds of the first and second screw members 21 and 28 is reduced and the second screw member 28 is advanced with a large load, so that high responsiveness is achieved. And a large braking force.
[0047]
The embodiments of the present invention have been described above. However, various design changes can be made in the present invention without departing from the gist thereof.
[0048]
For example, in the embodiment, the first screw member 21 is provided so as not to be movable in the axis L direction, and the second screw member 28 is provided so as to be movable in the axis L direction. The brake piston 17 may be driven.
[0049]
Further, in the embodiment, the continuously variable transmission 64 is provided in the first power transmission path 62, but it may be provided in the second power transmission path 63 or provided in both the first and second power transmission paths 62, 63. Or you can.
[0050]
Further, the continuously variable transmission 64 is not limited to the embodiment, but may have any structure.
[0051]
【The invention's effect】
As described above, according to the first aspect of the present invention, the female screw of the first screw member and the male screw of the second screw member mesh with each other, and one of the screw members is rotatable with respect to the brake caliper and the axis is The two screw members are relatively rotated and the other screw member is moved in the axial direction together with the braking member, thereby pressing the braking member against the member to be braked and generating a braking force. Control the increase, hold and decrease of the braking force by causing the braking member to approach, stop and separate from the member to be braked in a responsive manner only by changing the rotation speed without stopping or reversing the rotation of the brake can do.
[0052]
According to the second aspect of the invention, the relative rotation amount setting means sets the magnitude of the relative rotation of the first and second screw members, so that the moving direction of the second screw member with respect to the first screw member. By changing the moving speed and the moving speed, the moving direction, the moving speed and the moving load of the braking member can be arbitrarily controlled.
[0053]
According to the third aspect of the invention, the relative rotation amount setting means includes the first electric motor driving the first screw member and the second electric motor driving the second screw member. The magnitude of the relative rotation of the first and second screw members can be arbitrarily controlled by changing the rotation speed of the second electric motor.
[0054]
According to the invention described in claim 4, the relative rotation amount setting means transmits a single electric motor and the first and second powers for transmitting the driving force of the electric motor to the first and second screw members, respectively. Since the transmission path and the continuously variable transmission provided on at least one of the first and second power transmission paths are included, the speed ratio of the continuously variable transmission can be reduced while the number of electric motors is suppressed to the minimum number of one. By changing the magnitude, the magnitude of the relative rotation of the first and second screw members can be arbitrarily controlled.
[Brief description of the drawings]
1 is a longitudinal sectional view of an electric brake device according to a first embodiment; FIG. 2 is an enlarged view of a part of FIG. 1; FIG. 3 is a longitudinal sectional view of an electric brake device according to a second embodiment; Enlarged view of 4 parts [FIG. 5] Cross-sectional view taken along line 5-5 in FIG.
11 Brake caliper 14 Brake disc (member to be braked)
19 Brake pads (braking members)
21 1st screw member (one screw member)
21c female screw 28 second screw member (other screw member)
28a male screw 36 first electric motor (electric motor)
37 2nd electric motor (electric motor)
58 Screw mechanism 59 Relative rotation amount setting means 61 Electric motor 62 First power transmission path 63 Second power transmission path L Axis

Claims

The braking member (19) provided on the brake caliper (11) and the electric motor (36, 37, 61) are connected via a screw mechanism (58), and braking is performed by the driving force of the electric motor (36, 37, 61). In an electric brake device that generates a braking force by moving a member (19) in the direction of an axis (L) and pressing the member against a braked member (14),
The screw mechanism (58) includes a first screw member (21) having a female screw (21c) and a second screw member (28) having a male screw (28a) engaged with the first screw member (21c). , 28) are supported so as to be rotatable and immovable in the direction of the axis (L) with respect to the brake caliper (11), and the one screw member (21) and the other screw member (28) are supported. An electric brake device characterized in that the other screw member (28) is moved together with the braking member (19) in the direction of the axis (L) by relatively rotating.

The electric brake device according to claim 1, further comprising a relative rotation amount setting means (59) for setting a relative rotation amount of the first and second screw members (21, 28).

The relative rotation amount setting means (59) includes a first electric motor (36) for driving the first screw member (21) and a second electric motor (37) for driving the second screw member (28). 3. The electric brake device according to claim 2, wherein:

The relative rotation amount setting means (59) includes a single electric motor (61) and first and second electric motors (61) for transmitting the driving force of the electric motor (61) to the first and second screw members (21, 28), respectively. 3. A power transmission system comprising: a power transmission path (62, 63); and a continuously variable transmission (64) provided on at least one of the first and second power transmission paths (62, 63). 3. The electric brake device according to claim 1.