JP3909021B2

JP3909021B2 - Electric brake device

Info

Publication number: JP3909021B2
Application number: JP2003006043A
Authority: JP
Inventors: 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: 2007-04-25
Anticipated expiration: 2023-01-14
Also published as: JP2004218714A

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、一方のねじ部材と他方のねじ部材と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ものであり、前記第１ねじ部材はブレーキ力を発生する方向に回転するとともに前記第２ねじ部材はブレーキ力を解除する方向に回転し、第１、第２ねじ部材の相対回転の方向および大きさを変化させることでブレーキ力の増加、保持および減少を制御することを特徴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、その相対回転の方向および大きさ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徴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徴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徴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。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。
【００１７】
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。
【００１８】
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。
【００１９】
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。
【００２０】
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。
【００２１】
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。
【００２２】
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。
【００２３】
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。
【００２４】
次に、上記構成を備えた第１実施例の作用を説明する。
【００２５】
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。
【００２６】
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。
【００２７】
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。
【００２８】
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。
【００２９】
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。
【００３０】
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。
【００３１】
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。
【００３２】
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。
【００３３】
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。
【００３４】
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。
【００３５】
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。
【００３６】
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。
【００３７】
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。
【００３８】
次に、上記構成を備えた第２実施例の作用を説明する。
【００３９】
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。
【００４０】
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。
【００４１】
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。
【００４２】
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。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。
【００４３】
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。
【００４４】
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。
【００４５】
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。
【００４６】
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。
【００４７】
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。
【００４８】
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。
【００４９】
【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、その相対回転の方向および大きさ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。
【００５０】
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。
【００５１】
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。
【００５２】
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]
BACKGROUND OF THE INVENTION
In the present invention, a braking member provided on a brake caliper and an electric motor are connected via a screw mechanism, and the braking force is generated by moving the braking member in the axial direction by the driving force of the electric motor and pressing it against the member to be braked. The present invention relates to an electric brake device.
[0002]
[Prior art]
In general, in the 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]
It is known from the following patent documents that, instead of driving the brake piston hydraulically, the torque generated by the electric motor is converted into thrust by a reduction gear and a screw mechanism to drive the brake piston. According to this brake device, the brake force can be increased, held, and decreased by changing the rotation direction of the electric motor to advance, stop, and retract the brake piston.
[0004]
[Patent Literature]
Japanese Patent Laid-Open No. 11-321599
[Problems to be solved by the invention]
By the way, what is described in the above-mentioned patent document is designed to decelerate the rotational force of the electric motor with a reduction gear and transmit it to the screw mechanism, and drive the piston with the screw mechanism to generate the braking force. If the reduction ratio of the reduction gear is increased in order to increase the braking force, there is a problem that the responsiveness from when the electric motor is driven until the braking force rises decreases. In addition, when performing anti-lock brake control that increases or decreases the braking force at short time intervals, it is necessary to cause the electric motor to rotate forward, stop, reverse, stop, forward ... There is a further problem of lowering.
[0006]
The present invention has been made in view of the above-described circumstances, and an object thereof is to enhance the responsiveness when changing the braking force of the 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, a braking member provided on a brake caliper and an electric motor are connected via a screw mechanism, and the braking member is axially connected by a driving force of the electric motor. 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 meshing with the first screw member. , one of the threaded member of the second screw member rotatably and axially immovably supported relative to the brake caliper, by relative rotation and one of the threaded member and the other threaded member, braking the other threaded member is intended to move in the axial direction together with member, said first threaded member is the second screw member while rotating in a direction to generate a braking force to release the braking force Rotates in direction, the first electric braking device and controls the increase of the braking force, held and reduced by changing the direction and magnitude of the relative rotation of the second threaded 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 screw member is supported so as to be rotatable with respect to the brake caliper and not movable in the axial direction. And the other screw member is moved in the axial direction together with the brake member to press the brake member against the member to be braked to generate a braking force, so that the rotation of both screw members is stopped or reversed. Without changing the direction and magnitude of the relative rotation, it is possible to control the increase, retention and decrease of the braking force by causing the braking member to approach, stop and separate from the member to be braked with good responsiveness.
[0009]
According to the invention described in claim 2, and characterized in that in addition to the first aspect, having a first, relative rotation amount setting means for setting the magnitude of the relative rotation of the second threaded member An electric brake device is proposed.
[0010]
According to the above configuration, by setting the relative rotation magnitude of the first and second screw members by the relative rotation amount setting means, the moving direction and moving speed of the second screw member with respect to the first screw member are changed, The moving direction, moving speed, and moving load of the braking member can be arbitrarily controlled.
[0011]
According to the invention described in claim 3, in addition to the configuration of claim 2, 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. electric braking apparatus is proposed which comprises a second electric motor.
[0012]
According to the above configuration, since the relative rotation amount setting means includes the first electric motor that drives the first screw member and the second electric motor that drives the second screw member, the rotation of the first and second electric motors. The magnitude of relative rotation of the first and second screw members can be arbitrarily controlled by changing the number.
[0013]
According to the invention described in claim 4, in addition to the configuration of claim 2, the relative rotation amount setting means includes a single electric motor and a driving force of the electric motor for the first and second screw members. a first, second power transmission path for transmitting each of the first, the electric brake device which comprises a continuously variable transmission provided on at least one of the second power transmission path is proposed.
[0014]
According to the above configuration, the relative rotation amount setting means has a single electric motor, the 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 in at least one of the second power transmission paths. Therefore, the first, by changing the transmission ratio of the continuously variable transmission while suppressing the number of electric motors to one of the minimum number. The magnitude of relative rotation of the second screw member can be arbitrarily controlled.
[0015]
The brake disk 14 of the embodiment corresponds to the braked member 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 is 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]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings. 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 part 2 of FIG.
[0017]
The brake caliper 11 of the electric brake device includes a main body portion 12 supported by a knuckle (not shown) that rotatably supports a wheel, and an arm portion 13 that extends from the main body portion 12 across the brake disk 14 to the opposite side. Prepare. A brake pad 16 fixed to the inner surface of the arm 13 of the brake caliper 11 via a back plate 15 and a brake pad 19 fixed to the brake piston 17 via a back plate 18 abut against both surfaces of the brake disc 14. The brake piston 17 is connected to the inner surface of the main body 12 of the brake caliper 11 with a boot 20.
[0018]
A large-diameter recess 12a extending in the axis L direction and a small-diameter through-hole 12b are coaxially formed in the main body 12 of the brake caliper 11, and the through-hole 12b is formed in the shaft 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 accommodated in the recess 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 surface is supported by a circlip 27 attached to the open end of the recess 12a via a ball bearing 24, a retainer 25 and a spring washer 26.
[0019]
A shaft-like second screw member 28 is coaxially fitted inside the first screw member 21 disposed on the axis L, and the second screw member is connected to the female screw 21 c formed on the inner peripheral surface of the first screw member 21. A male screw 28 a formed on the outer peripheral surface of the first screw member 21 is engaged with the inner peripheral surface of the first screw member 21, and a bush 29 is disposed between the outer peripheral surface of the second screw member 28. A hemispherical head 28b formed at the tip of the second screw member 28 abuts against a dish-shaped recess 17a formed on the outer surface of the brake piston 17 so as to be relatively rotatable, and is formed near the tip of the second screw member 28. The folded inner peripheral surface of an annular piston return spring 30 whose outer periphery is fixed to the outer surface of the brake piston 17 is engaged with the annular groove 28c so as to be relatively rotatable.
[0020]
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 a first electric shaft 36 of the first electric motor 36 supported by the second gear housing 34 with a ball bearing 38 is first. A gear 40 is provided, and a fifth gear 43 is provided on the output shaft 42 of the second electric motor 37 supported by the ball bearing 41 on the second gear housing 34.
[0021]
A second gear 47 and a third gear 48 are provided on an intermediate shaft 46 supported by the first and second gear housings 32 and 34 via ball bearings 44 and 45, and the second gear 47 is the first gear. 40, and the third gear 48 is engaged 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 on the first and second gear housings 32 and 34 via ball bearings 50 and 51. The sixth gear 53 is the fifth gear. 43, the seventh gear 54 is engaged with an eighth gear 55 provided on the second screw member 28. The seventh gear 54 is formed long in the axis L direction, and the eighth gear 55 is movable in the axis L direction with respect to the seventh gear 54.
[0022]
The guide shaft 57 supported by the second gear housing 34 via the ball bearing 56 is slidably fitted into the guide hole 28d opened at the shaft end of the second screw member 28, whereby the second screw While preventing the member 28 from swinging, the movement in the axis L direction can be allowed. The guide shaft 57 can also be fixed to the second gear housing 34.
[0023]
The first screw member 21 and the second screw member 28 constitute a screw mechanism 58. 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.
[0024]
Next, the operation of the first embodiment having the above configuration will be described.
[0025]
When the first electric motor 36 is driven, the rotation of the output shaft 39 is decelerated by the first gear to the fourth gear 40, 47, 48, 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 decelerated by the fifth to eighth gears 43, 53, 54 and 55 to rotate the second screw member 28. At this time, if the first and second electric motors 36 and 37 are controlled so 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 screws meshing with each other. Since relative rotation does not occur between the female screw 21 c of the member 21 and the male screw 28 a of the second screw member 28, the second screw member 28 does not move in the axis L direction 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 while the surface pressure between the brake pads 16 and 19 and the brake disk 14 is released.
[0026]
From this state, when the rotational speed of the first electric motor 36 is increased and the rotational speed of the second electric motor 37 is decreased, the rotational speed of the first screw member 21> the rotational speed of the second screw member 28 and the first screw The second screw member 28 moves relative to the member 21 in the left direction in the drawing to press the brake piston 17. As a result, both brake pads 16 and 19 sandwich the both surfaces of the brake disc 14, and the wheels are braked by the frictional force generated on the sliding surfaces. The braking force generated by the electric brake device increases as the amount of relative movement of the second screw member 28 relative to the first screw member 21 in the left direction in the figure increases.
[0027]
When a predetermined braking force is obtained, if the rotational speeds of the first and second electric motors 36 and 37 are returned to the original state to match the rotational speeds of the first and second screw members 21 and 28, the brake piston 17 Stops at that position and brake force is maintained. Further, when the rotational speed of the first electric motor 36 is decreased and the rotational speed of the second electric motor 37 is increased, the rotational speed of the first screw member 21 <the rotational speed of the second screw member 28, and the first screw member 21. In contrast, the second screw member 28 relatively moves in the right direction in the figure. As a result, the brake piston 17 moves rightward in the drawing so as to follow the second screw member 28 via the piston return spring 30, so that both brake pads 16 and 19 are separated from both surfaces of the brake disk 14. Brake force decreases.
[0028]
When the second screw member 28 advances and retreats in the direction of the axis L, the eighth gear 55 integrated therewith also advances and retreats, but the seventh gear 54 that meshes with the eighth gear 55 is formed to be long in the direction of the axis L. The advancement / retraction of the screw member 28 is not hindered. For the same reason, it is possible to cope with the advancement of the second screw member 28 accompanying 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 portion 17a of the non-rotating brake piston 17 are in point contact, the frictional resistance of the contact portion can be minimized.
[0029]
As described above, when switching between increasing the braking force (advance of the brake piston 17), holding the braking force (stopping the brake piston 17), and decreasing the braking force (retracting the brake piston 17), the first and second It is not necessary to stop or reverse the electric motors 36 and 37, and it is only necessary to increase or decrease their rotational speed, so that the braking force can be controlled with good responsiveness.
[0030]
Further, if the rotational speed difference between 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 is reduced. The same effect as that obtained can be obtained, and the brake piston 17 can be moved forward with a large load to generate a large brake 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 decelerated. The same effect as that obtained by reducing the ratio can be obtained, and the responsiveness can be further enhanced by moving the brake piston 17 back and forth at a high speed.
[0031]
Therefore, before the brake pads 16 and 19 in the initial stage of braking are brought into contact with the brake disc 14, the second screw member 28 is rapidly advanced by increasing the rotational speed difference between the first and second screw members 21 and 28. After the pads 16 and 19 come into contact with the brake disk 14, the difference in rotational speed between the first and second screw members 21 and 28 is reduced and the second screw member 28 is advanced with a large load, thereby achieving high responsiveness. In addition, a large braking force can be achieved.
[0032]
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 portion 4 in FIG. 3, and FIG. 5 is a line 5-5 in FIG. It is sectional drawing. In the second embodiment, the same reference numerals as those in the first embodiment are assigned to the components corresponding to the components in the first embodiment, thereby omitting redundant description.
[0033]
Although the first embodiment includes first and second electric motors 36 and 37, 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 is transmitted to the second screw member 28 via the second power transmission path 63. Communicated.
[0034]
The first power transmission path 62 is provided in the continuously variable transmission 64, the third gear 67 provided on the second intermediate shaft 66 supported by the ball bearing 65 on the first gear housing 32, and the first screw member 21. The fourth gear 68 is configured. 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 on the second gear housing 34 and a first intermediate shaft 72 orthogonal to the output shaft 70. A supported driven disk 73 and a speed change roller 74 that simultaneously contacts the arc surface of the drive disk 71 and the arc surface of the driven disk 73 are provided. A first gear 75 formed integrally with the back surface of the driven disk 73 is engaged with a second gear 76 provided on the second intermediate shaft 66.
[0035]
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. The roller housing 77 is orthogonal to the plane formed by the output shaft 70 and the first intermediate shaft 72. The second gear housing 34 is rotatably supported by the support shafts 80, 80. A pin 84 provided on the output rod 83 of the solenoid 82 engages with a long hole 81 a formed at the tip of the arm member 81 fixed to the roller housing 77.
[0036]
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 by 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 into a guide hole 28d opened at the shaft end of the second screw member 28, whereby the second screw member 28 is slidably fitted. It is possible to allow movement in the direction of the axis L while preventing run-out.
[0037]
The electric motor 61, the continuously variable transmission 64, and the first to seventh gears 75, 76, 67, 68, 85, 88, 89 constitute a relative rotation amount setting means 59.
[0038]
Next, the operation of the second embodiment having the above configuration will be described.
[0039]
When the electric motor 61 is rotationally driven in a constant direction at a constant speed, 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 output shaft 70 rotates through the drive disk 71, the transmission roller 74, the driven disk 73, the first gear 75, the second gear 76, the third gear 67, and the fourth gear 68. 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.
[0040]
If the transmission gear ratio of the continuously variable transmission 64 is a predetermined transmission gear 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 that meshes with each other. Since no relative rotation occurs between 21c 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, the surface pressure between the brake pads 16, 19 and the brake disc 14 is released, and the electric brake device is in a non-braking state.
[0041]
When the output rod 83 of the solenoid 82 of the continuously variable transmission 64 is extended from this state, the speed change roller 74 rotates in the direction of arrow a around the support shaft 80 in FIG. 4, and the contact portion between the drive disk 71 and the speed change roller 74 is As the effective radius increases and the effective radius of the contact portion between the driven disk 73 and the transmission roller 74 decreases, the transmission 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 greater than the rotation speed of the second screw member 28, and the second screw member 28 is in the drawing with respect to the first screw member 21. The brake piston 17 is pressed by relative movement in the left direction. As a result, both brake pads 16 and 19 sandwich the both surfaces of the brake disc 14, and the wheels are braked by the frictional force generated on the sliding surfaces. The braking force generated by the electric brake device increases as the amount of relative movement of the second screw member 28 relative to the first screw member 21 in the left direction in the figure increases.
[0042]
When a predetermined braking force is obtained and the speed change roller 74 is returned to the neutral position by the solenoid 82, the brake piston 17 stops at that position and the braking force is maintained. When the output rod 83 of the solenoid 82 of the continuously variable transmission 64 is contracted, the speed change roller 74 rotates in the direction of 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 speed change roller 74 is increased. 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 rotational speed of the first screw member 21 is reduced. On the other hand, since the rotational speed of the second screw member 28 does not change, the rotational speed of the first screw member 21 is smaller than the rotational speed of the second screw member 28, and the second screw member 28 is in the drawing with respect to the first screw member 21. Move relative to the right. As a result, the brake piston 17 moves rightward in the drawing so as to follow the second screw member 28 via the piston return spring 30, so that both brake pads 16 and 19 are separated from both surfaces of the brake disk 14. Brake force decreases. As described above, the electric motor 61 is stopped when switching between increasing the braking force (braking the brake piston 17), holding the braking force (stopping the brake piston 17), and decreasing the braking force (retracting the brake piston 17). Alternatively, since it is not necessary to reverse the rotation, it is only necessary to change the gear ratio of the continuously variable transmission 64 disposed in the first power transmission path 62, so that the braking force can be controlled with good responsiveness.
[0043]
Further, if the speed change roller 74 is swung by a small angle to reduce the difference in rotation speed, the relative rotation speed of the first and second screw members 21 and 28 is decreased, and the brake piston 17 is moved forward slowly with a large load. Brake force can be generated. Conversely, if the speed difference of the first and second screw members 21 and 28 is increased by swinging the speed change roller 74 by a large angle, the relative number of rotations of the first and second screw members 21 and 28 is increased. The brake piston 17 can be advanced and retracted quickly with a small load, and the responsiveness can be enhanced.
[0044]
Therefore, before the brake pads 16 and 19 in the initial stage of braking are brought into contact with the brake disc 14, the second screw member 28 is rapidly advanced by increasing the rotational speed difference between the first and second screw members 21 and 28. After the pads 16 and 19 come into contact with the brake disk 14, the difference in rotational speed between the first and second screw members 21 and 28 is reduced and the second screw member 28 is advanced with a large load, thereby achieving high responsiveness. In addition, a large braking force can be achieved.
[0045]
Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.
[0046]
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.
[0047]
In the embodiment, the continuously variable transmission 64 is provided in the first power transmission path 62, but it is provided in the second power transmission path 63, or in both the first and second power transmission paths 62 and 63. Can be.
[0048]
Further, the continuously variable transmission 64 is not limited to that of the embodiment, and may be of any structure.
[0049]
【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 are meshed with each other, and one screw member is rotatable with respect to the brake caliper and is axial. Since the two screw members are relatively rotated and the other screw member is moved in the axial direction together with the brake member, the brake member is pressed against the member to be braked to generate a braking force. Without stopping or reversing the rotation of the brake member, it is possible to increase the braking force by approaching, stopping, and separating the braking member with respect to the member to be braked with high responsiveness simply by changing the direction and magnitude of the relative rotation . Retention and reduction can be controlled.
[0050]
According to the second aspect of the present invention, the relative rotation amount of the first and second screw members is set by the relative rotation amount setting means, thereby moving the second screw member relative to the first screw member. The moving direction, moving speed and moving load of the braking member can be arbitrarily controlled by changing the moving speed.
[0051]
According to the invention described in claim 3, the relative rotation amount setting means includes the first electric motor that drives the first screw member and the second electric motor that drives the second screw member. The magnitude of relative rotation of the first and second screw members can be arbitrarily controlled by changing the rotation speed of the second electric motor.
[0052]
According to a fourth aspect of the invention, 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 it includes a transmission path and a continuously variable transmission provided on at least one of the first and second power transmission paths, the transmission ratio of the continuously variable transmission can be reduced while keeping the number of electric motors to a minimum number. By changing it, the magnitude of 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 part 2 in FIG. 1. FIG. 3 is a longitudinal sectional view of an electric brake device according to a second embodiment. Enlarged view of part 4 [Fig. 5] Sectional view taken along line 5-5 in Fig. 4 [Explanation of symbols]
11 Brake caliper 14 Brake disc (braking member)
19 Brake pads (braking members)
21 First screw member (one screw member)
21c Female screw 28 Second screw member (the other screw member)
28a Male screw 36 1st electric motor (electric motor)
37 Second 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 brake member (19) provided on the brake caliper (11) and the electric motor (36, 37, 61) are connected via the screw mechanism (58), and braking is performed by the driving force of the electric motor (36, 37, 61). In the electric brake device for generating a braking force by moving the member (19) in the direction of the axis (L) and pressing the member (19) against the 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) meshing with the first screw member (21c). , 28) is supported so as to be rotatable with respect to the brake caliper (11) and immovable in the direction of the axis (L), and one screw member (21) and the other screw member (28) . The other screw member (28) is moved in the direction of the axis (L) together with the braking member (19) by relatively rotating the first screw member (21), and the first screw member (21) rotates in a direction to generate a braking force. At the same time, the second screw member (28) rotates in a direction to release the braking force, and the braking force increases by changing the direction and size of the relative rotation of the first and second screw members (21, 28). , Retention and reduction Electric brake system and controls.

First, characterized by comprising a relative rotation amount setting means (59) for setting the magnitude of the relative rotation of the second threaded member (21, 28), the electric brake apparatus according to claim 1.

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 for driving the second screw member (28) (37) characterized in that, the electric brake apparatus according to claim 2.

The relative rotation amount setting means (59) includes a first electric motor (61) and first and second screw members (21, 28) that transmit the driving force of the electric motor (61) to the first and second screw members (21, 28), respectively. a second power transmission path (62, 63), characterized in that it comprises first, continuously variable transmission provided on at least one of the second power transmission path (62, 63) and (64), according to claim 2 The electric brake device described in 1.