JP4059534B2 - Magnetostrictive brake - Google Patents

Magnetostrictive brake Download PDF

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Publication number
JP4059534B2
JP4059534B2 JP01298396A JP1298396A JP4059534B2 JP 4059534 B2 JP4059534 B2 JP 4059534B2 JP 01298396 A JP01298396 A JP 01298396A JP 1298396 A JP1298396 A JP 1298396A JP 4059534 B2 JP4059534 B2 JP 4059534B2
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Japan
Prior art keywords
friction material
displacement
magnetostrictive
brake
fluid
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JP01298396A
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Japanese (ja)
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JPH09203426A (en
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幸雄 村田
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株式会社曙ブレーキ中央技術研究所
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Priority to JP01298396A priority Critical patent/JP4059534B2/en
Priority to US08/789,267 priority patent/US5826683A/en
Priority to DE19703230A priority patent/DE19703230B4/en
Publication of JPH09203426A publication Critical patent/JPH09203426A/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16DCOUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00Parts or details
    • F16D65/14Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes

Abstract

PROBLEM TO BE SOLVED: To make a brake function intelligent so as to improve abrasion allowable capacity of a frictional material by arranging a fluid type-displacement enlarging mechanism between a magnetostrictive material and a frictional material to transfer the displacement rate of the magnetostrictive material to the frictional material by enlarging the displacement rate. SOLUTION: A fluid type displacement enlarging mechanism 5 is formed on a brake caliper 10. A large diameter piston 11 is arranged in such a constitution that one wall part of a cylinder 21 filled a fluid 20 and a displacement is transferred to the fluid 20 connecting to the other end of a magnetostrictive material 12, and a small diameter piston 23 is arranged in such a constitution that the other wall part is inserted and a displacement is transferred from the large diameter piston 11 to a pad 3 connecting to the pad 3. An area ratio between the large diameter piston 11 for push- pressing the fluid 20 and the small diameter piston 23 is designed to a proper value, add thereby, the enlarging rate of the displacement rate is set to a desired value. Seal members 24 are mounted on sliding parts of the pistons 11, 23 in the cylinder 21 to prevent leakage of the fluid 20. It is thus possible to carry out downsizing of a brake device, and to make a brake performance intelligent. It is also possible to improve allowable abrasion capacity of the frictional material.

Description

【0001】
【発明の属する技術分野】
本発明は、車両の制動に使用される電動式のブレーキ装置に関し、更に詳述すると、摩擦材を進退させる電動式のアクチュエータとして磁歪材を利用した構成の磁歪ブレーキに関する。
【0002】
【従来の技術】
従来より、油圧を駆動源として、車両に使用されるブレーキ装置は、油圧配管装備や油圧調整機構のために構成部品点数が増大して、構成が繁雑化するという問題があった。また、最近は、アンチロックブレーキシステムの装備や、トラクションコントロールシステムの装備など、ブレーキ機能のインテリジェント化が活発に行われているが、このようなインテリジェント化に際して、油圧駆動式の従来のブレーキ装置の場合、車輪のロック状態やスリップ状態に応じて所定の電気信号を油圧アクチュエータの機械的動作に変換する電気−油圧制御回路を付加しなければならない。そのため、制御系が繁雑化したり、あるいは、その機構上の特徴であるサーボ効果が影響してよりきめ細かなブレーキ制御が困難になるという問題があり、インテリジェント化になじみにくいという問題が指摘されていた。
【0003】
そこで、このような背景から、近年では、前記駆動源としては回転モータを使用し、回転−直線変換機構や減速機構等を介して摩擦材を制動用の回転体に押し付けることによって所定の制動力を生じさせる電動式のブレーキ装置(特開昭64−21229号公報参照)や、駆動源として圧電セラミックスを利用する電動式のブレーキ装置(特開昭60−136629号公報参照)が提案されている。
【0004】
【発明が解決しようとする課題】
前述のように駆動源として回転モータや圧電セラミックスを利用する電動式のブレーキ装置では、アンチロックブレーキシステムの装備やトラクションコントロールシステムの装備などのブレーキ機能のインテリジェント化が図り易くなる。
【0005】
しかし、駆動源として回転モータを利用するブレーキ装置では、回転−直線変換機構や減速機構等の装備のために、ブレーキ装置が大型化になるという問題があった。一方、駆動源として圧電セラミックスを利用するブレーキ装置では、摩擦材の進退動作に必要な直線運動を駆動源から直接得ることができ、回転−直線変換機構や減速機構等を使用せずに済むためにブレーキ装置を小型化することが可能であるが、圧電セラミックスは変位量が小さいため、摩擦材の摩耗を許容する能力が低いという問題があった。また、大電圧を発生するための装置を必要とするため、車載能力が低い問題があった。
【0006】
本発明は上記状況に鑑みてなされたもので、アンチロックブレーキシステムの装備やトラクションコントロールシステムの装備などのブレーキ機能のインテリジェント化が図り易く、また、装置の小型化に適すると共に、摩擦材を進退動作させるための変位量を大きく設定できて、摩擦材の摩耗許容能力も高めることができるブレーキ装置を提供す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の本発明に係る磁歪ブレーキは、 摩擦材を回転体に向けて進退可能に支持している摩擦材支持部材と、前記回転体に前記摩擦材を押し付けて制動力を得るため該摩擦材を前記回転体に向けて進退移動させる電動式のアクチュエータと、ブレーキ操作部の操作状態に応じて前記アクチュエータの動作を制御するコントロール・ユニットとを具備すると共に、前記アクチュエータは、一端が前記摩擦材支持部材に係止されて磁界が加えられると前記摩擦材の進退方向に沿って長さが変化する棒状に形成された磁歪材と、該磁歪材の外周を囲むように前記摩擦材支持部材に固定されて入力電圧に応じた磁界を前記磁歪材に加える電磁コイルとを備え、前記コントロール・ユニットは、前記電磁コイルの入力電圧を前記ブレーキ操作部の操作状態に応じて制御し、制動に必要な前記摩擦材の進退動作を、前記磁歪材の磁歪による伸縮によって実現する磁歪ブレーキであって、前記磁歪材と前記摩擦材との間に、前記磁歪材の変位量を拡大して前記摩擦材に伝達する流体式の変位拡大機構を装備し、該変位拡大機構は、前記摩擦材支持部材上に形成されて流体を封入したシリンダと、該シリンダの一方の壁部を挿通すると共に前記磁歪材の他端にヨークを介して連結されて前記磁歪材の変位を前記シリンダ内の流体に伝える大径ピストンと、前記シリンダの他方の壁部を挿通すると共に前記摩擦材に連結されて前記大径ピストンから流体に伝えられた変位を前記摩擦材に伝える小径ピストンとを備え、且つ、前記アクチュエータに当接して該アクチュエータと共に前記摩擦材支持部材内に組み込まれたことを特徴とする。
【0008】
【0009】
本発明の上記構成によれば、摩擦材を制動用の回転体に向けて進退させるための駆動源として磁歪によって伸縮する磁歪材を使用したもので、例えば、棒状の磁歪材に磁界を加えて摩擦材の進退方向に伸縮させることで、摩擦材の進退方向に沿って摩擦材の進退動作に必要な直線運動を駆動源である磁歪材から直接得ることができる。
【0010】
また、前記磁歪材の伸縮は該磁歪材の外周を囲う電磁コイルに印加する電圧によって制御するので、電気的に直接動作を制御できる。そして、磁歪材における伸縮量は、該磁歪材に加える電界を強めること、すなわち、電磁コイルに印加する電圧を高めることで容易に増大させることができ、圧電セラミックスの場合と比較すると、摩擦材を進退動作させるための変位量を大きくすることができるとともに、消費電力を低く抑えることができる。
【0011】
また、磁歪材の変位を流体式の変位拡大機構で拡大し摩擦材に伝達する構成のため、摩擦材を進退動作させるための変位量を磁歪材の変位量以上に大きく設定することができる。
【0012】
【発明の実施の形態】
以下、本発明に係る磁歪ブレーキの好適な実施の形態を図面を参照して詳細に説明する。図1は本発明に係る磁歪ブレーキの要部断面図である。この磁歪ブレーキ1は、車両用のディスクブレーキとして設けられ、制動用の回転体であるブレーキディスク(ロータ)2と、該ブレーキディスク2に押し付けることで制動力を発生させる摩擦材であるパッド3と、該パッド3をブレーキディスク2に向けて進退移動させるための電動式のアクチュエータ4と、該アクチュエータ4が発生する変位量を拡大して前記パッド3に伝達する流体式の変位拡大機構5と、ブレーキ操作部であるブレーキペダル6の操作状態に応じて前記アクチュエータ4の動作を制御するコントロール・ユニット(ECU)8とを備えて構成される。
【0013】
前記パッド3は、前記ブレーキディスク2を挟むように一対装備されていて、摩擦材支持部材であるブレーキキャリパ10によって、ブレーキディスク2に向って進退自在に支持されている。
【0014】
前記アクチュエータ4は、棒状をなして一端(図では、左端)が前記ブレーキキャリパ10に係止されると共に、他端がヨーク7を介して前記変位拡大機構5を形成する大径ピストン11に連結(実際は当接しているだけ)されて、磁界が加えられると磁歪によって軸方向の長さが変化する磁歪材12と、該磁歪材12の外周を囲うように前記ブレーキキャリパ10内に固定されて入力電圧に応じた磁界を前記磁歪材12に加える略円筒状の電磁コイル14とを備えて構成される。
【0015】
また、前記ブレーキペダル6は、運転者によって踏下されると、そのとき踏下されたストロークまたは踏力が公知のセンサ16によって前記コントロール・ユニット8に通知される。
【0016】
流体式の変位拡大機構5は、ブレーキキャリパ10上に形成されて流体20を封入したシリンダ21と、該シリンダ21の一方の壁部を挿通すると共に前記磁歪材12の他端に連結されて前記磁歪材12の変位をシリンダ21内の流体20に伝える前記大径ピストン11と、前記シリンダ21の他方の壁部を挿通すると共に前記パッド3に連結されて前記大径ピストン11から流体20に伝えられた変位をパッド3に伝える小径ピストン23とを備え、シリンダ21内の流体20を押圧する大径ピストン11及び小径ピストン23の面積比を適宜値に設計することで変位量の拡大率を所望値に設定できる構成とされている。シリンダ21内に封入される流体20は、非圧縮性及び耐熱性を有する流体で、例えばブレーキオイル等が適用される。また、シリンダ21内のそれぞれのピストン11、23の摺動部分には、流体20の漏出を防止するシール部材24が装備されている。
【0017】
前記コントロール・ユニット8は、前記センサ16からの信号によって運転者の制動指令を検知して前記アクチュエータ4の動作を制御するものであるが、本実施形態の場合は、前記センサ16からの信号に応じて前記電磁コイル14の入力電圧を制御する。すなわち、上記構成の磁歪ブレーキ1は、パッド3をブレーキディスク2に向けて進退させるための駆動源として磁歪によって伸縮する磁歪材12を使用したもので、棒状の磁歪材12に磁界を加えてパッド3の進退方向に伸縮させる構成であれば、パッド3の進退動作に必要な直線運動を駆動源である磁歪材12から直接得ることができ、回転−直線変換機構や減速機構等を使用せずに済むためにブレーキ装置を小型化することができる。
【0018】
また、前記磁歪材12の伸縮は該磁歪材12の外周を囲う電磁コイル14の印加電圧によって制御するもので、電気的に直接動作を制御できるため、アンチロックブレーキシステムの装備やトラクションコントロールシステムの装備などのブレーキ機能のインテリジェント化も図り易い。
【0019】
さらに、磁歪材12における伸縮量は、該磁歪材12に加える電界を強めること、すなわち、電磁コイル14に印加する電圧を高めることで容易に増大させることができ、圧電セラミックスの場合と比較すると、パッド3を進退動作させるための変位量(ストローク)を大きくすることができるとともに、低電圧で駆動でき、消費電力を低く抑えられる。
【0020】
また、磁歪材12の変位を変位拡大機構5で拡大してパッド3に伝達する構成のため、パッド3を進退動作させるための変位量を磁歪材12の変位量以上に大きくすることができ、パッド3に要求される変位をより小さな磁歪材12で実現したり、あるいは、パッド3の変位可能な範囲をより大きく設定して、パッド3の摩耗許容能力をさらに向上させることが可能になる。
【0021】
また、磁歪材12の変位量を拡大してパッド3に伝える機構として、従来より知られている種々の変位拡大機構を利用することが可能であるが、この実施形態のように、流体20を押圧する大径ピストン11及び小径ピストン23の面積比から変位量の拡大率を設定する流体式の変位拡大機構5を適用すれば、図からも明らかなとおり、少ない部品と簡単な構造で所望の性能を得ることができる。本実施形態の場合、例えば、大径ピストン11及び小径ピストン23の面積比を10:1に設定すると、磁歪材12の変位量を10倍に拡大してパッド3に伝えることができ、前記磁歪材12として、変位量が1000PPMで軸長が10cmの磁歪素子を使用すれば、パッド3のストロークは1mmにすることができ、パッド3のストロークとして十分な値が得られる。
【0022】
なお、前記の実施形態では、磁歪材12を棒状として長さ方向に磁歪を生じるようにしたが、例えば、径方向に磁歪を生じる磁歪材を利用することも考えられる。ただし、径方向に磁歪を生じる磁歪材を利用した場合は、パッド3に連結されているピストン部材が磁歪材の径方向の変位で圧迫された流体によって変位するように、流体式の変位拡大機構の構成を改善する必要がある。また、本発明による磁歪ブレーキは、前記実施形態に示したディスクブレーキに限定されるものでなく、例えば、ドラムブレーキにも適用可能である。
【0023】
【発明の効果】
以上記載したとおり、本発明の磁歪ブレーキによれば、磁歪によって伸縮する磁歪材を、摩擦材を制動用の回転体に向けて進退させるための駆動源として使用したので、摩擦材の進退動作に必要な直線運動を駆動源である磁歪材から直接得ることができ、回転−直線変換機構や減速機構等を使用せずに済むためにブレーキ装置を小型化することができる。また、前記磁歪材の伸縮は該磁歪材の外周を囲む電磁コイルの印加電圧によって電気的に直接制御できるため、アンチロックブレーキシステムの装備やトラクションコントロールシステムの装備などのブレーキ機能のインテリジェント化も図り易い。さらに、磁歪材における伸縮量は、該磁歪材に加える電界を強めること、すなわち、電磁コイルの印加電圧を高めることで容易に増大させることができ、圧電セラミックスの場合と比較すると、摩擦材を進退動作させるための変位量を大きくすることができて、摩擦材の摩耗許容能力も高めることができる。さらに、磁歪材の変位を流体式の変位拡大機構で拡大して摩擦材に伝達する構成のため、摩擦材を進退動作させるための変位量を磁歪材の変位量以上に大きく設定することができ、摩擦材に要求される変位量をより小さな磁歪材で実現したり、あるいは、摩擦材の変位範囲をより大きく設定しておいて、摩擦材の摩耗許容能力をさらに向上させることが可能になる。
【図面の簡単な説明】
【図1】 本発明に係る磁歪ブレーキの一実施形態の要部断面図である。
【符号の説明】
1 磁歪ブレーキ
2 ブレーキディスク(制動用の回転体)
3 パッド(摩擦材)
4 アクチュエータ
5 流体式の変位拡大機構
6 ブレーキペダル
7 ヨーク
8 コントロール・ユニット(ECU)
10 ブレーキキャリパ(摩擦材支持部材)
11 大径ピストン
12 磁歪材
14 電磁コイル
16 センサ
20 流体
21 シリンダ
23 小径ピストン
24 シール部材
[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric brake device used for braking a vehicle. More specifically, the present invention relates to a magnetostrictive brake having a configuration using a magnetostrictive material as an electric actuator for advancing and retracting a friction material.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a brake device used in a vehicle using hydraulic pressure as a driving source has a problem that the number of components increases due to hydraulic piping equipment and a hydraulic adjustment mechanism, and the configuration becomes complicated. Recently, intelligent brake functions such as anti-lock brake systems and traction control systems have been actively used. In this case, it is necessary to add an electro-hydraulic control circuit that converts a predetermined electric signal into a mechanical operation of the hydraulic actuator in accordance with the locked state or slip state of the wheel. For this reason, the control system has become complicated, or the servo effect that is a feature of the mechanism has an effect, making it difficult to fine-tune brake control, and it has been pointed out that it is difficult to adapt to intelligentization. .
[0003]
In view of this, in recent years, a rotary motor is used as the drive source, and a predetermined braking force is applied by pressing the friction material against the rotating body for braking via a rotation-linear conversion mechanism, a speed reduction mechanism, or the like. Has been proposed (see Japanese Patent Laid-Open No. 64-21229) and an electric brake device using piezoelectric ceramics as a drive source (see Japanese Patent Laid-Open No. 60-136629). .
[0004]
[Problems to be solved by the invention]
As described above, in an electric brake device that uses a rotary motor or piezoelectric ceramics as a drive source, it is easy to make intelligent brake functions such as an anti-lock brake system and a traction control system.
[0005]
However, in a brake device that uses a rotary motor as a drive source, there is a problem that the brake device becomes large due to the provision of a rotation-linear conversion mechanism, a speed reduction mechanism, and the like. On the other hand, in a brake device using piezoelectric ceramics as a drive source, the linear motion necessary for the forward / backward movement of the friction material can be obtained directly from the drive source, and it is not necessary to use a rotation-linear conversion mechanism, a speed reduction mechanism, or the like. Although it is possible to reduce the size of the brake device, the piezoelectric ceramic has a problem that it has a low ability to allow wear of the friction material because of its small displacement. Further, since a device for generating a large voltage is required, there is a problem that the in-vehicle capability is low.
[0006]
The present invention has been made in view of the above circumstances, and it is easy to make intelligent brake functions such as an anti-lock brake system and a traction control system, and it is suitable for downsizing of the device, and the friction material is advanced and retracted. It is an object of the present invention to provide a brake device that can set a large amount of displacement for operation and can also increase the wear tolerance of a friction material.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a magnetostrictive brake according to the present invention includes a friction material support member that supports a friction material so as to be able to advance and retreat toward a rotating body, and obtains a braking force by pressing the friction material against the rotating body. since the electric actuator for advancing and retracting movement toward the friction member to the rotating member, while and a control unit for controlling the operation of said actuator in accordance with the operation state of the brake operating unit, the actuator has one end Is engaged with the friction material support member, and when a magnetic field is applied, a magnetostrictive material formed in a rod shape whose length changes along the advancing and retreating direction of the friction material, and the friction so as to surround the outer periphery of the magnetostrictive material An electromagnetic coil fixed to a material support member and applying a magnetic field corresponding to an input voltage to the magnetostrictive material, and the control unit is configured to convert the input voltage of the electromagnetic coil to the bracelet. A magnetostrictive brake that is controlled in accordance with the operation state of the operation unit and realizes the advancing / retreating operation of the friction material necessary for braking by expansion / contraction by magnetostriction of the magnetostrictive material, between the magnetostrictive material and the friction material And a fluid displacement magnifying mechanism for enlarging the amount of displacement of the magnetostrictive material and transmitting it to the friction material, the displacement magnifying mechanism comprising a cylinder formed on the friction material support member and enclosing a fluid. A large-diameter piston that passes through one wall of the cylinder and is connected to the other end of the magnetostrictive material via a yoke to transmit the displacement of the magnetostrictive material to the fluid in the cylinder, and the other wall of the cylinder and a small-diameter piston to communicate displacement conveyed to the fluid from said large diameter piston is connected to the friction material to the friction material with inserting the parts, and said together with the actuator in contact with the actuator Characterized in that incorporated in Kosuzai support member.
[0008]
[0009]
According to the above configuration of the present invention, a magnetostrictive material that expands and contracts by magnetostriction is used as a drive source for advancing and retreating the friction material toward the braking rotor. For example, a magnetic field is applied to a rod-shaped magnetostrictive material. By expanding and contracting in the advancing / retreating direction of the friction material, a linear motion necessary for the advancing / retreating operation of the friction material along the advancing / retreating direction of the friction material can be directly obtained from the magnetostrictive material that is a driving source.
[0010]
Further, since the expansion and contraction of the magnetostrictive material is controlled by the voltage applied to the electromagnetic coil surrounding the outer periphery of the magnetostrictive material, the direct operation can be electrically controlled. The amount of expansion and contraction in the magnetostrictive material can be easily increased by increasing the electric field applied to the magnetostrictive material, that is, by increasing the voltage applied to the electromagnetic coil. The amount of displacement for advancing and retracting can be increased, and power consumption can be kept low.
[0011]
Further, since the displacement of the magnetostrictive material is enlarged by a fluid displacement magnifying mechanism and transmitted to the friction material, the displacement amount for moving the friction material forward and backward can be set larger than the displacement amount of the magnetostrictive material.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a magnetostrictive brake according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a magnetostrictive brake according to the present invention. The magnetostrictive brake 1 is provided as a disc brake for a vehicle, and includes a brake disc (rotor) 2 that is a rotating body for braking, and a pad 3 that is a friction material that generates a braking force by being pressed against the brake disc 2. An electric actuator 4 for moving the pad 3 forward and backward toward the brake disc 2, and a fluid displacement expanding mechanism 5 for expanding the amount of displacement generated by the actuator 4 and transmitting it to the pad 3. A control unit (ECU) 8 that controls the operation of the actuator 4 in accordance with the operation state of the brake pedal 6 that is a brake operation unit is provided.
[0013]
A pair of the pads 3 is provided so as to sandwich the brake disk 2 and is supported by a brake caliper 10 which is a friction material support member so as to be able to advance and retract toward the brake disk 2.
[0014]
The actuator 4 has a rod shape and one end (the left end in the figure) is locked to the brake caliper 10 and the other end is connected to a large-diameter piston 11 forming the displacement enlarging mechanism 5 via a yoke 7. (Actually only abutting) and when a magnetic field is applied, the magnetostrictive material 12 whose axial length changes due to magnetostriction, and the brake caliper 10 is fixed so as to surround the outer periphery of the magnetostrictive material 12 And a substantially cylindrical electromagnetic coil 14 for applying a magnetic field corresponding to an input voltage to the magnetostrictive material 12.
[0015]
Further, when the brake pedal 6 is stepped on by the driver, the stroke or the stepping force stepped on at that time is notified to the control unit 8 by a known sensor 16.
[0016]
The fluid-type displacement magnifying mechanism 5 is formed on the brake caliper 10 and encloses the fluid 20, and passes through one wall portion of the cylinder 21 and is connected to the other end of the magnetostrictive material 12. The large-diameter piston 11 that transmits the displacement of the magnetostrictive material 12 to the fluid 20 in the cylinder 21 and the other wall portion of the cylinder 21 are inserted and connected to the pad 3 and transmitted from the large-diameter piston 11 to the fluid 20. And a small-diameter piston 23 that transmits the displacement to the pad 3, and the area ratio of the large-diameter piston 11 and the small-diameter piston 23 that presses the fluid 20 in the cylinder 21 is designed to an appropriate value so that an expansion rate of the displacement amount is desired. It can be set to a value. The fluid 20 sealed in the cylinder 21 is a fluid having incompressibility and heat resistance, and for example, brake oil or the like is applied. Further, the sliding portions of the respective pistons 11 and 23 in the cylinder 21 are equipped with a seal member 24 for preventing the fluid 20 from leaking out.
[0017]
The control unit 8 detects the driver's braking command based on a signal from the sensor 16 and controls the operation of the actuator 4. In the present embodiment, the control unit 8 uses the signal from the sensor 16 as a control signal. In response, the input voltage of the electromagnetic coil 14 is controlled. That is, the magnetostrictive brake 1 having the above configuration uses a magnetostrictive material 12 that expands and contracts by magnetostriction as a drive source for moving the pad 3 forward and backward toward the brake disk 2. 3 can be directly obtained from the magnetostrictive material 12 as a drive source without using a rotation-linear conversion mechanism, a speed reduction mechanism, or the like. Therefore, the brake device can be reduced in size.
[0018]
Further, the expansion and contraction of the magnetostrictive material 12 is controlled by the applied voltage of the electromagnetic coil 14 surrounding the outer periphery of the magnetostrictive material 12, and since the direct operation can be electrically controlled, the anti-lock brake system equipment and the traction control system Brake functions such as equipment can be made intelligent.
[0019]
Furthermore, the amount of expansion / contraction in the magnetostrictive material 12 can be easily increased by increasing the electric field applied to the magnetostrictive material 12, that is, by increasing the voltage applied to the electromagnetic coil 14, compared to the case of piezoelectric ceramics. The displacement (stroke) for moving the pad 3 forward and backward can be increased, and the pad 3 can be driven at a low voltage, and the power consumption can be kept low.
[0020]
Further, since the displacement of the magnetostrictive material 12 is enlarged by the displacement magnifying mechanism 5 and transmitted to the pad 3, the displacement amount for moving the pad 3 forward and backward can be made larger than the displacement amount of the magnetostrictive material 12, The displacement required for the pad 3 can be realized with a smaller magnetostrictive material 12, or the displaceable range of the pad 3 can be set larger to further improve the wear tolerance of the pad 3.
[0021]
Further, as a mechanism for enlarging the amount of displacement of the magnetostrictive material 12 and transmitting it to the pad 3, various conventionally known displacement enlarging mechanisms can be used. If the fluid displacement magnifying mechanism 5 that sets the magnification of the displacement amount is applied from the area ratio of the large-diameter piston 11 and the small-diameter piston 23 to be pressed, as is apparent from the figure, the desired number of parts and a simple structure can be used. Performance can be obtained. In the case of the present embodiment, for example, if the area ratio of the large diameter piston 11 and the small diameter piston 23 is set to 10: 1, the displacement amount of the magnetostrictive material 12 can be expanded to 10 times and transmitted to the pad 3, and the magnetostriction If a magnetostrictive element having a displacement of 1000 PPM and an axial length of 10 cm is used as the material 12, the stroke of the pad 3 can be 1 mm, and a sufficient value can be obtained as the stroke of the pad 3.
[0022]
In the above-described embodiment, the magnetostrictive material 12 is rod-shaped to cause magnetostriction in the length direction. However, for example, it is also conceivable to use a magnetostrictive material that produces magnetostriction in the radial direction. However, when a magnetostrictive material that generates magnetostriction in the radial direction is used, a fluid displacement expanding mechanism is used so that the piston member connected to the pad 3 is displaced by the fluid compressed by the radial displacement of the magnetostrictive material. It is necessary to improve the composition of Further, the magnetostrictive brake according to the present invention is not limited to the disc brake shown in the above embodiment, and can be applied to, for example, a drum brake.
[0023]
【The invention's effect】
As described above, according to the magnetostrictive brake of the present invention, the magnetostrictive material that expands and contracts due to magnetostriction is used as a drive source for moving the friction material forward and backward toward the rotating body for braking. Necessary linear motion can be obtained directly from the magnetostrictive material that is the drive source, and it is not necessary to use a rotation-linear conversion mechanism, a speed reduction mechanism, or the like, so that the brake device can be miniaturized. In addition, since the expansion and contraction of the magnetostrictive material can be directly and electrically controlled by the applied voltage of the electromagnetic coil surrounding the outer periphery of the magnetostrictive material, the brake functions such as the anti-lock brake system and the traction control system can be made intelligent. easy. Furthermore, the amount of expansion and contraction in the magnetostrictive material can be easily increased by increasing the electric field applied to the magnetostrictive material, that is, by increasing the voltage applied to the electromagnetic coil. The amount of displacement for operation can be increased, and the wear tolerance capability of the friction material can be increased. Furthermore, because the displacement of the magnetostrictive material is expanded by the fluid displacement expansion mechanism and transmitted to the friction material, the displacement amount for moving the friction material forward and backward can be set larger than the displacement amount of the magnetostrictive material. The amount of displacement required for the friction material can be realized with a smaller magnetostrictive material, or the friction material can be further improved in its wear tolerance by setting the displacement range of the friction material larger. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of an embodiment of a magnetostrictive brake according to the present invention.
[Explanation of symbols]
1 Magnetostrictive brake 2 Brake disk (rotating body for braking)
3 Pad (friction material)
4 Actuator 5 Fluid displacement enlarging mechanism 6 Brake pedal 7 Yoke 8 Control unit (ECU)
10 Brake caliper (friction material support member)
11 Large Diameter Piston 12 Magnetostrictive Material 14 Electromagnetic Coil 16 Sensor 20 Fluid 21 Cylinder 23 Small Diameter Piston 24 Seal Member

Claims (1)

摩擦材を回転体に向けて進退可能に支持している摩擦材支持部材と、
前記回転体に前記摩擦材を押し付けて制動力を得るため該摩擦材を前記回転体に向けて進退移動させる電動式のアクチュエータと、
ブレーキ操作部の操作状態に応じて前記アクチュエータの動作を制御するコントロール・ユニットとを具備すると共に、
前記アクチュエータは、一端が前記摩擦材支持部材に係止されて磁界が加えられると前記摩擦材の進退方向に沿って長さが変化する棒状に形成された磁歪材と、該磁歪材の外周を囲むように前記摩擦材支持部材に固定されて入力電圧に応じた磁界を前記磁歪材に加える電磁コイルとを備え、
前記コントロール・ユニットは、前記電磁コイルの入力電圧を前記ブレーキ操作部の操作状態に応じて制御し、制動に必要な前記摩擦材の進退動作を、前記磁歪材の磁歪による伸縮によって実現する磁歪ブレーキであって、
前記磁歪材と前記摩擦材との間に、前記磁歪材の変位量を拡大して前記摩擦材に伝達する流体式の変位拡大機構を装備し、該変位拡大機構は、前記摩擦材支持部材上に形成されて流体を封入したシリンダと、該シリンダの一方の壁部を挿通すると共に前記磁歪材の他端にヨークを介して連結されて前記磁歪材の変位を前記シリンダ内の流体に伝える大径ピストンと、前記シリンダの他方の壁部を挿通すると共に前記摩擦材に連結されて前記大径ピストンから流体に伝えられた変位を前記摩擦材に伝える小径ピストンとを備え、且つ、前記アクチュエータに当接して該アクチュエータと共に前記摩擦材支持部材内に組み込まれたことを特徴とする磁歪ブレーキ。
A friction material support member that supports the friction material toward the rotating body so as to be able to advance and retreat; and
An electric actuator that moves the friction material forward and backward toward the rotating body to obtain a braking force by pressing the friction material against the rotating body;
A control unit for controlling the operation of the actuator according to the operation state of the brake operation unit,
The actuator has a rod-shaped magnetostrictive material whose length changes along the advancing and retreating direction of the friction material when one end is locked to the friction material supporting member and a magnetic field is applied, and an outer periphery of the magnetostrictive material An electromagnetic coil fixed to the friction material support member so as to surround and applying a magnetic field according to an input voltage to the magnetostrictive material,
The control unit controls an input voltage of the electromagnetic coil according to an operation state of the brake operation unit, and realizes a forward / backward movement of the friction material necessary for braking by expansion / contraction by magnetostriction of the magnetostrictive material. Because
A hydrodynamic displacement enlarging mechanism is provided between the magnetostrictive material and the friction material to increase the amount of displacement of the magnetostrictive material and transmit it to the friction material, and the displacement enlarging mechanism is mounted on the friction material support member. A cylinder formed with a fluid sealed therein, and inserted through one wall of the cylinder and connected to the other end of the magnetostrictive material via a yoke to transmit the displacement of the magnetostrictive material to the fluid in the cylinder. A piston having a diameter, and a small-diameter piston that is inserted through the other wall portion of the cylinder and connected to the friction material and transmits the displacement transmitted from the large-diameter piston to the fluid. A magnetostrictive brake, which is brought into contact with the actuator and is incorporated in the friction material support member together with the actuator.
JP01298396A 1996-01-29 1996-01-29 Magnetostrictive brake Expired - Fee Related JP4059534B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP01298396A JP4059534B2 (en) 1996-01-29 1996-01-29 Magnetostrictive brake
US08/789,267 US5826683A (en) 1996-01-29 1997-01-28 Magnetostrictive brake
DE19703230A DE19703230B4 (en) 1996-01-29 1997-01-29 Magnetostrictive brake

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP01298396A JP4059534B2 (en) 1996-01-29 1996-01-29 Magnetostrictive brake

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JPH09203426A JPH09203426A (en) 1997-08-05
JP4059534B2 true JP4059534B2 (en) 2008-03-12

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Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000104769A (en) * 1998-09-28 2000-04-11 Akebono Brake Res & Dev Center Ltd Disc brake
US6170921B1 (en) * 1999-01-21 2001-01-09 Meritor Heavy Vehicle Systems, Llc Magnetostrictive brake actuation mechanism
JP6513867B1 (en) * 2018-06-08 2019-05-15 ワックデータサービス株式会社 Brake caliper
CN110962825B (en) * 2019-11-19 2023-12-29 南京航空航天大学 Disk type linear control braking system based on magnetostrictive material and control method thereof
CN114992259B (en) * 2022-05-18 2023-03-17 南京航空航天大学 Electromagnetic combined type sliding plate chassis line control brake system and multi-target optimization method thereof

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