JP3690486B2

JP3690486B2 - Eddy current reducer

Info

Publication number: JP3690486B2
Application number: JP36527899A
Authority: JP
Inventors: 徹桑原
Original assignee: Isuzu Motors Ltd
Current assignee: Isuzu Motors Ltd
Priority date: 1999-12-22
Filing date: 1999-12-22
Publication date: 2005-08-31
Anticipated expiration: 2019-12-22
Also published as: JP2001186746A

Description

【０００１】
【発明の属する技術分野】
本発明は例えば車両の摩擦ブレーキを補助する渦電流減速装置、特に構成が簡単で製造が容易な強磁性板と一体をなす案内筒を備えた渦電流減速装置に関するものである。
【０００２】
【従来の技術】
特公平６−１０１９２２号公報に開示されるような、回転軸に結合した左右１対の制動円板の間に永久磁石（以下単にこれを磁石という）を有する磁石支持輪を備えた渦電流減速装置では、非制動時に磁石からの磁界が外部へ洩れないように、磁石を覆う強磁性板（ポールピース）をかなり厚く（一般的には１０〜１６ｍｍ）しなければならい。このため、アルミニウム鋳物からなる案内筒に強磁性板を鋳込んだり、非磁性のステンレス鋼板を円板状に金型プレスにより成形したうえ周方向等間隔に多数の開口を設け、該開口に強磁性板を嵌合したうえ溶接していた。前者の方法はアルミニウム鋳物に対する強磁性板の鋳込み不良率が高く、後者の方法は強磁性板の溶接に手数が掛るので加工経費の削減が難しい。
【０００３】
【発明が解決しようとする課題】
本発明の課題は上述の問題に鑑み、案内筒の両側壁を強磁性体である厚肉のステンレス鋼板から構成し、磁石と対向する強磁性部分を残し、磁石と対向しない非磁性または弱磁性部分を熱処理により形成し、両者の間の特性を明確にした、製造が簡単で安価な渦電流減速装置を提供することにある。
【０００４】
【課題を解決するための手段】
上記課題を解決するために、本発明の構成は回転軸に結合した左右１対の制動円板と、左右１対の制動円板の間の非回転部分に配設した断面長方形の内空部を有する案内筒と、該案内筒の内空部に回動可能に支持した少くとも１つの磁石支持輪と、該磁石支持輪に周方向等間隔に支持した多数の磁石と、前記案内筒の両側壁に設けた前記各磁石と対向する強磁性部分とを有し、前記磁石からの磁界に基づく渦電流により前記制動円板に制動力を発生させる渦電流減速装置において、前記案内筒の両側壁を強磁性体である厚肉のステンレス鋼板から構成し、前記両側壁の前記磁石と対向する強磁性部分はそのままとし、前記両側壁の前記磁石と対向しない部分を溶体化して高温状態から急冷することにより非磁性または弱磁性とし、前記両側壁の非磁性または弱磁性部分と強磁性部分との境界に幅の狭い径方向の溝を設けたことを特徴とする。
【０００５】
【発明の実施の形態】
本発明では磁石支持輪の側面を覆う案内筒の両側壁を強磁性体である厚肉のステンレス鋼板から構成し、両側壁の磁石と対向する強磁性部分をそのままとし、磁石と対向しない部分を温度８００〜１３５０℃に加熱して溶体化した後に急冷して非磁性または弱磁性にし、磁石と対向する強磁性部分と磁石と対向しない非磁性または弱磁性部分との境界に少くとも径方向の溝を加工する。つまり、案内筒の両側壁の磁石と対向しない部分は、温度８００〜１３５０℃に加熱して溶体化した後に急冷すると、非磁性または弱磁性のオーステナイト相に変態する。案内筒の両側壁は厚肉のステンレス鋼板から構成し、両側壁に溝加工と熱処理を施すだけであるから、製造が簡単であり、製造単価の低減に役立つ。
【０００６】
また、境界の溝により強磁性部分と非磁性または弱磁性部分との各特性が明瞭に区画され、非制動時の短絡的磁気回路と制動時の磁気回路とが効率的に形成され、洩れ磁束が減じられる。
【０００７】
【実施例】
図１に示すように、本発明による渦電流減速装置は例えば車両用変速機の出力回転軸２に結合される１対の導体からなる制動円板３と、１対の制動円板３の間に配設される不動の案内筒５と、案内筒５の断面長方形の内空部に相対回動可能に支持した非磁性体からなる内外１対の磁石支持輪８，１０とを備えている。制動円板３はボス３ａを回転軸２にスプライン嵌合して固定され、ボス３ａとボス３ａから放射状に延びる複数のスポーク３ｂと放射状に延びる複数の通風路３ｃを有する円板部とを例えば鋳造により一体に形成される。
【０００８】
案内筒５は左右１対の環状の側壁１６の間に、外筒２１と内筒２２とを結合して断面長方形の内空部を形成してもよいが、図示の実施例では断面溝形の筒体に環状板を結合して構成される。内筒２２はボス５ａから放射方向に延びる複数のスポーク５ｂと一体に形成され、ボス５ａが軸受４により回転軸２に支持される。案内筒５は適当な手段により例えば変速機の歯車箱に固定される。多数の磁石１２を周方向等間隔に支持する内側の磁石支持輪８は、案内筒５の内部に軸受７により回動可能に支持される。磁石１２と同数の磁石１３を周方向等間隔に支持する外側の磁石支持輪１０は、内側の磁石支持輪８の外周壁に軸受９により回動可能に支持される。軸受７，９は磁石支持輪８，１０の相対回動を得るものであるから、何れか一方だけでもよい。磁石支持輪８，１０の両側面に潤滑油を含浸させた薄い滑り板１４が重ね合され、両側壁１６の内面に摺接可能とされる。
【０００９】
図１〜３に示すように、内側の磁石支持輪８はアルミニウムなどの非磁性体からなり、多数の扇形をなす磁石１２が、側壁１６と対向しかつ側壁１６に対する極性が周方向に交互に異なるように配設される。好ましくは、磁石１２は磁石支持輪８に鋳込まれる。外側の磁石支持輪１０も同様に多数の扇形をなす磁石１３が、側壁１６と対向しかつ側壁１６に対する極性が周方向に交互に異なるように配設される。図示してないが、磁石支持輪１０の外周壁に形成した部分歯車に、案内筒５の外筒２１に固定した電動機のピニオン軸が噛み合され、磁石支持輪１０は磁石１３の配列ピツチｐだけ正逆回動可能とされる。しかし、磁石支持輪１０の代りに、磁石支持輪８を磁石１２の配列ピツチｐだけ正逆回動可能に支持してもよい。強磁性部分６は内外１対の磁石１２，１３の側面を覆う面積の扇形のものである。
【００１０】
図２，３に示すように、本発明では案内筒５の両側壁１６を、１３クロム（Cr）系ステンレス鋼などの強磁性体である厚肉のステンレス鋼板から構成し、両側壁１６の磁石１２，１３と対向する強磁性部分６と、磁石１２，１３と対向しない部分６ａとの境界に、幅の狭い径方向の溝３０を設ける。両側壁１６の内面の磁石１２，１３と対向しない部分６ａは、温度８００℃以上に加熱して溶体化し、高温状態から急冷することにより非磁性または弱磁性に形成される。つまり、案内筒５の両側壁１６の磁石１２，１３と対向しない部分６ａは、１３クロム（Cr）系ステンレス鋼などの強磁性体である厚肉のステンレス鋼板であるが、温度８００〜１３５０℃に加熱して溶体化した後に急冷することにより、非磁性または弱磁性のオーステナイト相に変態させたものである。好ましくは、両側壁１６の外面にも溝３０を、外周面と内周面にも溝３０ａをそれぞれ設け、１対の溝３０と１対の溝３０ａが、強磁性部分６と非磁性または弱磁性部分６ａとの境界を囲むようにする。側壁１６の溝３０，３０ａは熱処理後に加工してもよいが、熱処理前に溝３０，３０ａを加工し、該溝３０，３０ａに冷却剤を装入するなどして、磁石１２，１３と対向しない部分６ａだけを熱処理するのが好ましい。
【００１１】
図１に示すように、制動円板３の強磁性部分６と対向しない内外周縁部の少くとも一方に、銅などの良伝導体からなる環状体２３，２４が結合される。環状体２３，２４により制動円板３の内部を流れる渦電流が径方向に広がり、制動トルクを増大させる。
【００１２】
次に、本発明による渦電流減速装置の作動について説明する。１対の制動円板３が回転軸２と一緒に回転されるのに対し、図１に示すように、非制動時、内外の磁石１２，１３の強磁性部分６に対する極性が異なる配列では、左右２対の強磁性部分６の間で短絡的磁気回路ｚが生じ、制動円板３に磁界を及ぼさない。左右１対の強磁性部分６は磁石１２，１３を両側から全面的に挟む状態にあるから、制動円板３への洩れ磁束は殆ど生じず、制動円板３は引きずりトルクを受けない。
【００１３】
制動時、電動機により外側の磁石支持輪１０を磁石１３の配列ピツチｐだけ回動すると、図２に示すように、内外の磁石１２，１３の強磁性部分６に対する極性が同じになる。したがつて、内外の磁石１２と磁石１３（図２を参照、以下同じ）が等しく強磁性部分６を経て制動円板３に磁界を及ぼす。回転する制動円板３が磁界を横切る時、制動円板３に渦電流が発生し、制動円板３が制動トルクを受ける。この時、各磁石１２から強磁性部分６、制動円板３、隣りの強磁性部分６、隣りの磁石１２、反対側の強磁性部分６、反対側の制動円板３、隣りの強磁性部分６へと磁気回路ｗが生じる。磁石１３も左右１対の制動円板３の間に同様の磁気回路ｗを発生する。
【００１４】
上述のように、内外の磁石支持輪８，１０の磁石１２，１３の配列ピツチｐの回転差動が、案内筒５の両側壁１６の強磁性部分６は、回転軸２を含む面で短絡的磁気回路ｚを形成する非制動状態と、案内筒５の側壁１６から制動円板３に磁界を及ぼし磁気回路ｗを形成する制動状態とに切り換える。
【００１５】
強磁性部分６と非磁性または弱磁性部分６ａとの境界に溝３０を設けたことにより、各部分６，６ａの磁気特性が明確に区画され、非制動時の短絡的磁気回路と制動時の磁気回路とが効率的に形成され、洩れ磁束が減じられ、非制動時の引摺りトルクが抑えられる。
【００１６】
図４，５に示す実施例では、案内筒５の強磁性体である厚肉のステンレス鋼板からなる両側壁１６に、多数の強磁性部分６と非磁性または弱磁性部分６ａとが周方向に交互に形成される。強磁性部分６と同数の磁石１２，１２ａを支持する左右１対の磁石支持輪８，８ａは、案内筒５の内空部に軸受７，７ａにより回動可能に支持される。磁石支持輪８，８ａの外側面に潤滑油を含浸した薄い滑り板１４が結合され、側壁１６の内面に摺接可能とされる。右側の磁石支持輪８ａはアルミニウムなどの非磁性体からなり、強磁性部分６と同数の扇形をなす磁石１２ａが、右側壁１６の強磁性部分６と対向しかつ強磁性部分６に対する極性が周方向に交互に異なるように配設される。好ましくは、磁石１２ａは磁石支持輪８ａに鋳込まれる。同様に、左側の磁石支持輪８もアルミニウムなどの非磁性体からなり、強磁性部分６と同数の扇形をなす磁石１２が、左側壁１６の強磁性部分６と対向しかつ強磁性部分６に対する極性が周方向に交互に異なるように配設される。磁石支持輪８ａは図１に示したものと同様の手段により磁石１２ａの配列ピツチだけ正逆回動可能とされる。図示してないが、各強磁性部分６は磁石１２，１２ａとほぼ同形のものである。
【００１７】
案内筒５の両側壁１６を、１３クロム（Cr）系ステンレス鋼などの強磁性体である厚肉のステンレス鋼板から構成し、両側壁１６の磁石１２，１２ａと対向する強磁性部分６と対向しない部分６ａとの境界に、幅の狭い径方向の溝３０を設け、両側壁１６の内面の磁石１２，１２ａと対向しない部分６ａを温度８００℃以上に加熱して溶体化し、高温状態から急冷することにより非磁性または弱磁性を形成する。好ましくは、両側壁１６の外面にも溝３０を、外周面と内周面にも溝３０ａをそれぞれ設け、１対の溝３０と１対の溝３０ａが強磁性部分６と非磁性または弱磁性部分６ａとの境界を囲むようにする。他の構成は図１の実施例と同様である。
【００１８】
非制動時、左側の磁石支持輪８を固定し、右側の磁石支持輪８ａを磁石１２の配列ピツチだけ回動すると、相対向する磁石１２，１２ａの極性が同じになり、磁気回路が相殺されるので、制動円板３に磁界を及ぼさない。制動時、１対の磁石支持輪８，８ａは相対向する左右の磁石１２，１２ａの極性が逆になる位置に保持される。したがつて、左右の磁石１２，１２ａが一体的に左右１対の強磁性部分６を経て左右１対の制動円板３に垂直な磁界を及ぼす。回転する左右１対の制動円板３が磁界を横切る時、左右１対の制動円板３に渦電流が発生し、左右１対の制動円板３が制動トルクを受ける。この時、図５に示すように、磁石１２，１２ａから強磁性部分６、制動円板３、隣りの強磁性部分６、隣りの磁石１２ａ，１２、反対側の強磁性部分６、反対側の制動円板３、隣りの強磁性部分６へと磁気回路ｗが生じる。
【００１９】
上述の実施例において、右側の磁石支持輪８ａを固定し、左側の磁石支持輪８を電動機またはアクチユエータにより磁石１２の配列ピツチだけ正逆回動するようにしてもよい。
【００２０】
図６〜８に示す実施例では、案内筒５の強磁性体である厚肉のステンレス鋼板からなる両側壁１６に、多数の強磁性部分６と非磁性または弱磁性部分６ａとが周方向交互に形成される。単一の磁石支持輪８が案内筒５の内空部に軸受７により正逆回動可能に支持される。磁石支持輪８には多数の磁石１２が周方向等間隔に結合される。磁石１２は左右の側壁１６の各強磁性部分６に２つずつ対向され、かつ強磁性部分６に対する極性が周方向に２つずつ異なるように配設される。磁石支持輪８の両側面に潤滑油を含浸させた薄い滑り板１４が結合され、側壁１６の内面に摺接可能とされる。図示してないが、磁石支持輪８の外周壁に形成した部分歯車に、案内筒５に固定した電動機のピニオンが噛み合され、磁石支持輪８は磁石１２の配列ピツチｐだけ正逆回動可能とされる。
【００２１】
案内筒５の両側壁１６を、１３クロム（Cr）系ステンレス鋼などの強磁性体である厚肉のステンレス鋼板から構成し、両側壁１６の磁石１２と対向する強磁性部分６と磁石１２と対向しない非磁性または弱磁性部分６ａとの境界に、幅の狭い径方向の溝３０を設け、両側壁１６の部分６ａを温度８００℃以上に加熱して溶体化し、高温状態から急冷することにより、非磁性または弱磁性のオーステナイト相にする。好ましくは、両側壁１６の外面にも溝３０を、外周面と内周面にも溝３０ａをそれぞれ設け、１対の溝３０と１対の溝３０ａが強磁性部分６と非磁性または弱磁性部分６ａとの境界を囲むようにする。他の構成は図１の実施例と同様である。
【００２２】
非制動時、周方向に隣接する２つの磁石１２の共通の強磁性部分６に対する極性が互いに異なる配列では、図８に示すように、左右１対の強磁性部分６の間で短絡的磁気回路ｚが生じ、制動円板３に磁界を及ぼさない。制動時、磁石支持輪８を磁石１２の配列ピツチｐだけ回動すると、共通の強磁性部分６に対向する２つの磁石１２の極性が同じになる。したがつて、図７に示すように、２つの磁石１２が等しく強磁性部分６を経て左右１対の制動円板３に磁界を及ぼす。回転する左右１対の制動円板３が磁界を横切る時、左右１対の制動円板３に渦電流が発生し、左右１対の制動円板３が制動トルクを受ける。この時、磁石１２から強磁性部分６、制動円板３、隣りの強磁性部分６、隣りの磁石１２、反対側の強磁性部分６、反対側の制動円板３、隣りの強磁性部分６へと磁気回路ｗが生じる。
【００２３】
図９に示す実施例は、図６〜８に示す実施例において周方向に並ぶ２つの同極性の磁石１２を１つにしたものである。案内筒５の両側壁１６を、１３クロム（Cr）系ステンレス鋼などの強磁性体である厚肉のステンレス鋼板から構成し、両側壁１６の磁石１２と対向する強磁性部分６と、磁石１２と対向しない部分６ａとの境界に、幅の狭い径方向の溝３０を設け、両側壁１６の部分６ａを温度８００℃以上に加熱して溶体化し、高温状態から急冷することにより非磁性または弱磁性のオーステナイト相にする。好ましくは、両側壁１６の外面にも溝３０を、外周面と内周面にも溝３０ａをそれぞれ設け、１対の溝３０と１対の溝３０ａが強磁性部分６と非磁性または弱磁性部分６ａとの境界を囲むようにする。他の構成は図１の実施例と同様である。
【００２４】
案内筒５の側壁１６の各強磁性部分６に対向して１つの磁石１２が、強磁性部分６に対する極性が周方向に交互に異なるように磁石支持輪８に結合される。磁石支持輪８を磁石１２の半配列ピツチだけ回動することにより、案内筒５の側壁１６の強磁性部分６に周方向に並ぶ２つの磁石１２が部分的に対向して短絡的磁気回路ｚを形成する非制動位置と、案内筒５の側壁１６の強磁性部分６に１つの磁石１２が全面的に対向して制動円板３との間に磁気回路を形成する制動位置とに切り換わる。
【００２５】
【発明の効果】
本発明は上述のように、回転軸に結合した左右１対の制動円板と、左右１対の制動円板の間の非回転部分に配設した断面長方形の内空部を有する案内筒と、該案内筒の内空部に回動可能に支持した少くとも１つの磁石支持輪と、該磁石支持輪に周方向等間隔に支持した多数の磁石と、前記案内筒の両側壁に設けた前記各磁石と対向する強磁性部分とを有し、前記磁石からの磁界に基づく渦電流により前記制動円板に制動力を発生させる渦電流減速装置において、前記案内筒の両側壁を強磁性体である厚肉のステンレス鋼板から構成し、前記両側壁の前記磁石と対向する強磁性部分はそのままとし、前記両側壁の前記磁石と対向しない部分を溶体化して高温状態から急冷することにより非磁性または弱磁性とし、前記両側壁の非磁性または弱磁性部分と強磁性部分との境界に幅の狭い径方向の溝を設けたものであり、構成が簡単で案内筒の製造が容易であり、従来構造のものとほぼ同様の制動性能が得られるとともに、製造経費を低減できる。
【００２６】
また、強磁性部分と非磁性または弱磁性部分との境界の溝により、両者の各磁気特性が明確に区別され、非制動時の短絡的磁気回路と制動時の磁気回路が効率的に形成され、洩れ磁束が減じられる。
【００２７】
制動円板の強磁性部分と対向しない内外周縁部の少くとも一方に、銅などの良伝導体からなる環状体が結合される。環状体により制動円板の内部を流れる渦電流が径方向に広がり、制動トルクを増大させる。
【図面の簡単な説明】
【図１】本発明に係る渦電流減速装置の正面断面図である。
【図２】同渦電流減速装置を展開して示す平面断面図である。
【図３】同渦電流減速装置の側面断面図である。
【図４】本発明の第２実施例に係る渦電流減速装置の正面断面図である。
【図５】同渦電流減速装置を展開して示す平面断面図である。
【図６】本発明の第３実施例に係る渦電流減速装置の正面断面図である。
【図７】同渦電流減速装置の非制動状態を展開して示す平面断面図である。
【図８】同渦電流減速装置の制動状態を展開して示す平面断面図である。
【図９】本発明の第４実施例に係る渦電流減速装置の非制動状態を展開して示す平面断面図である。
【符号の説明】
２：回転軸３：制動円板４：軸受５：案内筒６：強磁性部分６ａ：非磁性または弱磁性部分８，８ａ：磁石支持輪９：軸受１０，１０ａ：磁石支持輪１２，１２ａ：磁石１３：磁石１４：滑り板１６：側壁２１：外筒２２：内筒２３：良伝導体の環状体２４：良伝導体の環状体３０，３０ａ：溝[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an eddy current reduction device that assists a friction brake of a vehicle, for example, and more particularly to an eddy current reduction device that includes a guide cylinder that is integrated with a ferromagnetic plate that is simple in configuration and easy to manufacture.
[0002]
[Prior art]
In an eddy current reduction device including a magnet support wheel having a permanent magnet (hereinafter simply referred to as a magnet) between a pair of left and right braking disks coupled to a rotating shaft as disclosed in Japanese Patent Publication No. 6-101922. In order to prevent the magnetic field from the magnet from leaking outside during non-braking, the ferromagnetic plate (pole piece) covering the magnet must be made considerably thick (generally 10 to 16 mm). For this reason, a ferromagnetic plate is cast into a guide tube made of an aluminum casting, or a non-magnetic stainless steel plate is formed into a disk shape by a die press, and a large number of openings are provided at equal intervals in the circumferential direction. The magnetic plate was fitted and welded. The former method has a high casting defect rate of the ferromagnetic plate with respect to the aluminum casting, and the latter method is difficult to reduce the processing cost because it takes time to weld the ferromagnetic plate.
[0003]
[Problems to be solved by the invention]
In view of the above problems, the object of the present invention is to make both side walls of a guide tube from a thick stainless steel plate that is a ferromagnetic material, leaving a ferromagnetic portion facing the magnet, and non-magnetic or weak magnetism not facing the magnet. An object of the present invention is to provide an eddy current reduction device that is easy to manufacture and inexpensive, in which parts are formed by heat treatment and characteristics between the two are clarified.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the configuration of the present invention has a pair of left and right braking disks coupled to a rotating shaft, and an inner space having a rectangular cross section disposed in a non-rotating portion between the pair of left and right braking disks. A guide tube, at least one magnet support wheel rotatably supported in the inner space of the guide tube, a number of magnets supported at equal intervals in the circumferential direction on the magnet support wheel, and both side walls of the guide tube In the eddy current reduction device that has a ferromagnetic portion facing each of the magnets provided on the magnet and generates a braking force on the braking disk by an eddy current based on a magnetic field from the magnet, both side walls of the guide tube are provided. It is made of a thick stainless steel plate that is a ferromagnetic material, and the ferromagnetic part of the both side walls facing the magnet is left as it is, and the part of the both side walls not facing the magnet is solutionized and rapidly cooled from a high temperature state. a non-magnetic or weakly magnetic, the said side walls In that a non-magnetic or weakly magnetic part and a ferromagnetic part and a narrow radial groove width at the boundary of the features.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, both side walls of the guide tube covering the side surfaces of the magnet support wheel are made of a thick stainless steel plate that is a ferromagnetic material, and the ferromagnetic portions that face the magnets on both side walls are left as they are, and the portions that do not face the magnets. It is heated to a temperature of 800 to 1350 ° C. to form a solution and then rapidly cooled to be nonmagnetic or weakly magnetic, and at least radially in the boundary between the ferromagnetic part facing the magnet and the nonmagnetic or weakly magnetic part not facing the magnet Process the groove. That is, when the portions of the guide cylinders that do not face the magnets on both side walls are heated to a temperature of 800 to 1350 ° C. to form a solution and then rapidly cooled, they are transformed into a nonmagnetic or weakly magnetic austenite phase. Since both side walls of the guide tube are made of thick stainless steel plates and only the grooves and heat treatment are performed on both side walls, the manufacturing is simple and helps to reduce the manufacturing unit price.
[0006]
In addition, the characteristics of the ferromagnetic part and the non-magnetic or weak magnetic part are clearly defined by the groove at the boundary, and a short-circuit magnetic circuit during non-braking and a magnetic circuit during braking are efficiently formed, and leakage flux Is reduced.
[0007]
【Example】
As shown in FIG. 1, an eddy current reduction device according to the present invention includes, for example, a brake disc 3 composed of a pair of conductors coupled to an output rotating shaft 2 of a vehicle transmission and a pair of brake discs 3. And a pair of inner and outer magnet support wheels 8 and 10 made of a non-magnetic material supported in an inner space of a rectangular cross section of the guide tube 5 so as to be relatively rotatable. . The brake disc 3 is fixed by a spline fitting of the boss 3a to the rotary shaft 2, and includes a boss 3a, a plurality of spokes 3b extending radially from the boss 3a, and a disc portion having a plurality of ventilation passages 3c extending radially, for example. It is integrally formed by casting.
[0008]
The guide tube 5 may form an inner hollow portion having a rectangular cross section by connecting the outer tube 21 and the inner tube 22 between a pair of left and right annular side walls 16 in the illustrated embodiment. An annular plate is coupled to the cylindrical body. The inner cylinder 22 is formed integrally with a plurality of spokes 5 b extending in the radial direction from the boss 5 a, and the boss 5 a is supported on the rotating shaft 2 by the bearing 4. The guide cylinder 5 is fixed to, for example, a gear box of a transmission by appropriate means. An inner magnet support wheel 8 that supports a large number of magnets 12 at equal intervals in the circumferential direction is rotatably supported by a bearing 7 inside the guide tube 5. The outer magnet support ring 10 that supports the same number of magnets 13 as the magnets 12 at equal intervals in the circumferential direction is rotatably supported by the bearing 9 on the outer peripheral wall of the inner magnet support ring 8. Since the bearings 7 and 9 obtain the relative rotation of the magnet support wheels 8 and 10, only one of them may be used. Thin sliding plates 14 impregnated with lubricating oil are superposed on both side surfaces of the magnet support wheels 8, 10 so that they can slide on the inner surfaces of both side walls 16.
[0009]
As shown in FIGS. 1 to 3, the inner magnet support ring 8 is made of a nonmagnetic material such as aluminum, and a large number of sector-shaped magnets 12 are opposed to the side wall 16, and the polarities with respect to the side wall 16 are alternately arranged in the circumferential direction. They are arranged differently. Preferably, the magnet 12 is cast into the magnet support wheel 8. Similarly, the outer magnet support ring 10 is also provided with a large number of fan-shaped magnets 13 so as to face the side wall 16 and to have different polarities relative to the side wall 16 in the circumferential direction. Although not shown, the pinion shaft of the electric motor fixed to the outer cylinder 21 of the guide cylinder 5 is meshed with the partial gear formed on the outer peripheral wall of the magnet support wheel 10, and the magnet support wheel 10 has an arrangement pitch p of the magnets 13. Only forward and reverse rotation is possible. However, instead of the magnet support wheel 10, the magnet support wheel 8 may be supported by the arrangement pitch p of the magnets 12 so as to be able to rotate forward and backward. The ferromagnetic portion 6 has a sector shape covering the side surfaces of the inner and outer pair of magnets 12 and 13.
[0010]
As shown in FIGS. 2 and 3, in the present invention, both side walls 16 of the guide tube 5 are made of a thick stainless steel plate that is a ferromagnetic material such as 13 chromium (Cr) stainless steel, and the magnets on both side walls 16. A narrow radial groove 30 is provided at the boundary between the ferromagnetic portion 6 facing the magnets 12 and 13 and the portion 6a not facing the magnets 12 and 13. The portions 6a on the inner surfaces of the side walls 16 that do not face the magnets 12 and 13 are heated to a temperature of 800 ° C. or higher to form a solution, and are rapidly non-magnetically or weakly magnetized by being rapidly cooled from a high temperature state. That is, the portion 6a of the side wall 16 of the guide cylinder 5 that does not oppose the magnets 12 and 13 is a thick stainless steel plate that is a ferromagnetic material such as 13 chromium (Cr) stainless steel, but the temperature is 800 to 1350 ° C. The solution is transformed into a nonmagnetic or weakly magnetic austenite phase by rapid cooling after heating to solution. Preferably, grooves 30 are also provided on the outer surface of both side walls 16 and grooves 30a are provided on the outer peripheral surface and the inner peripheral surface, respectively, so that one pair of grooves 30 and one pair of grooves 30a are nonmagnetic or weak with the ferromagnetic portion 6. The boundary with the magnetic part 6a is surrounded. The grooves 30 and 30a on the side wall 16 may be processed after the heat treatment, but the grooves 30 and 30a are processed before the heat treatment, and a coolant is inserted into the grooves 30 and 30a so as to face the magnets 12 and 13. It is preferable to heat-treat only the portion 6a that is not.
[0011]
As shown in FIG. 1, annular bodies 23 and 24 made of a good conductor such as copper are coupled to at least one of the inner and outer peripheral edge portions not facing the ferromagnetic portion 6 of the brake disc 3. Due to the annular bodies 23 and 24, eddy currents flowing inside the braking disk 3 spread in the radial direction, and the braking torque is increased.
[0012]
Next, the operation of the eddy current reduction device according to the present invention will be described. While a pair of brake disks 3 are rotated together with the rotating shaft 2, as shown in FIG. 1, in an arrangement in which the polarities with respect to the ferromagnetic portions 6 of the inner and outer magnets 12 and 13 are different during non-braking, A short-circuit magnetic circuit z is generated between the left and right pairs of ferromagnetic portions 6 and does not exert a magnetic field on the brake disc 3. Since the pair of left and right ferromagnetic portions 6 are in a state of sandwiching the magnets 12 and 13 from both sides, almost no leakage magnetic flux to the brake disc 3 is generated and the brake disc 3 is not subjected to drag torque.
[0013]
At the time of braking, when the outer magnet support wheel 10 is rotated by the arrangement pitch p of the magnet 13 by the electric motor, the polarities of the inner and outer magnets 12 and 13 with respect to the ferromagnetic portion 6 become the same as shown in FIG. Therefore, the inner and outer magnets 12 and 13 (see FIG. 2; the same applies hereinafter) equally apply a magnetic field to the brake disc 3 through the ferromagnetic portion 6. When the rotating brake disc 3 crosses the magnetic field, an eddy current is generated in the brake disc 3 and the brake disc 3 receives a braking torque. At this time, from each magnet 12, the ferromagnetic portion 6, the braking disk 3, the adjacent ferromagnetic portion 6, the adjacent magnet 12, the opposite ferromagnetic portion 6, the opposite braking disc 3, the adjacent ferromagnetic portion. 6 produces a magnetic circuit w. The magnet 13 also generates a similar magnetic circuit w between the pair of left and right braking disks 3.
[0014]
As described above, the rotational differential of the arrangement pitch p of the magnets 12 and 13 of the inner and outer magnet support wheels 8 and 10 is short-circuited on the plane including the rotating shaft 2 at the ferromagnetic portions 6 of the side walls 16 of the guide tube 5. Switching between a non-braking state in which the magnetic circuit z is formed and a braking state in which a magnetic field is applied from the side wall 16 of the guide cylinder 5 to the braking disc 3 to form the magnetic circuit w.
[0015]
By providing the groove 30 at the boundary between the ferromagnetic portion 6 and the non-magnetic or weak magnetic portion 6a, the magnetic characteristics of the portions 6 and 6a are clearly defined, and the short-circuit magnetic circuit at the time of non-braking and at the time of braking A magnetic circuit is efficiently formed, leakage magnetic flux is reduced, and drag torque during non-braking is suppressed.
[0016]
In the embodiment shown in FIGS. 4 and 5, a large number of ferromagnetic portions 6 and nonmagnetic or weak magnetic portions 6 a are arranged in the circumferential direction on both side walls 16 made of a thick stainless steel plate, which is a ferromagnetic body of the guide tube 5. It is formed alternately. A pair of left and right magnet support wheels 8, 8 a that support the same number of magnets 12, 12 a as the ferromagnetic portion 6 are rotatably supported by bearings 7, 7 a in the inner space of the guide tube 5. A thin sliding plate 14 impregnated with lubricating oil is coupled to the outer surfaces of the magnet support wheels 8, 8 a so that they can slide on the inner surface of the side wall 16. The right magnet support ring 8a is made of a nonmagnetic material such as aluminum, and the same number of fan-shaped magnets 12a as the ferromagnetic portions 6 are opposed to the ferromagnetic portions 6 of the right side wall 16 and the polarity with respect to the ferromagnetic portions 6 is circumferential. It arrange | positions so that it may differ in a direction alternately. Preferably, the magnet 12a is cast into the magnet support wheel 8a. Similarly, the left magnet support ring 8 is also made of a non-magnetic material such as aluminum, and the same number of fan-shaped magnets 12 as the ferromagnetic portions 6 are opposed to the ferromagnetic portions 6 of the left side wall 16 and against the ferromagnetic portions 6. The polarities are alternately arranged in the circumferential direction. The magnet support wheel 8a can be rotated forward and backward by the arrangement pitch of the magnets 12a by the same means as shown in FIG. Although not shown, each ferromagnetic portion 6 has substantially the same shape as the magnets 12 and 12a.
[0017]
Both side walls 16 of the guide tube 5 are made of a thick stainless steel plate made of a ferromagnetic material such as 13 chromium (Cr) stainless steel, and are opposed to the ferromagnetic portions 6 facing the magnets 12 and 12a of the side walls 16. A narrow radial groove 30 is provided at the boundary with the portion 6a not to be heated, and the portion 6a not facing the magnets 12 and 12a on the inner surfaces of the side walls 16 is heated to a temperature of 800 ° C. or more to form a solution and rapidly cooled from a high temperature state. By doing so, non-magnetic or weak magnetism is formed. Preferably, grooves 30 are also provided on the outer surface of both side walls 16, and grooves 30a are provided on the outer peripheral surface and the inner peripheral surface, respectively, and the pair of grooves 30 and the pair of grooves 30a are nonmagnetic or weakly magnetic with the ferromagnetic portion 6. The boundary with the portion 6a is surrounded. Other configurations are the same as those of the embodiment of FIG.
[0018]
When the left magnet support wheel 8 is fixed and the right magnet support wheel 8a is rotated by the arrangement pitch of the magnets 12 during non-braking, the magnets 12 and 12a facing each other have the same polarity, and the magnetic circuit is canceled. Therefore, no magnetic field is applied to the brake disc 3. During braking, the pair of magnet support wheels 8 and 8a are held at positions where the polarities of the left and right magnets 12 and 12a facing each other are reversed. Therefore, the left and right magnets 12 and 12a integrally apply a perpendicular magnetic field to the pair of left and right brake disks 3 via the pair of left and right ferromagnetic portions 6. When the pair of rotating left and right braking disks 3 cross the magnetic field, an eddy current is generated in the pair of left and right braking disks 3, and the pair of left and right braking disks 3 receive a braking torque. At this time, as shown in FIG. 5, from the magnets 12 and 12a to the ferromagnetic portion 6, the brake disc 3, the adjacent ferromagnetic portion 6, the adjacent magnets 12a and 12, the opposite ferromagnetic portion 6, the opposite side A magnetic circuit w is generated to the brake disc 3 and the adjacent ferromagnetic portion 6.
[0019]
In the above-described embodiment, the right magnet support wheel 8a may be fixed, and the left magnet support wheel 8 may be rotated forward and backward by the arrangement pitch of the magnets 12 by an electric motor or an actuator.
[0020]
In the embodiment shown in FIGS. 6 to 8, a large number of ferromagnetic portions 6 and nonmagnetic or weak magnetic portions 6 a are alternately arranged in the circumferential direction on both side walls 16 made of a thick stainless steel plate that is a ferromagnetic body of the guide tube 5. Formed. A single magnet support wheel 8 is supported in the inner space of the guide tube 5 by a bearing 7 so as to be able to rotate forward and backward. A large number of magnets 12 are coupled to the magnet support wheel 8 at equal intervals in the circumferential direction. The magnets 12 are arranged so as to be opposed to the ferromagnetic portions 6 of the left and right side walls 16 two by two, and so that the polarities with respect to the ferromagnetic portions 6 are different by two in the circumferential direction. A thin sliding plate 14 impregnated with lubricating oil is coupled to both side surfaces of the magnet support wheel 8 so as to be capable of sliding contact with the inner surface of the side wall 16. Although not shown, the pinion of the motor fixed to the guide tube 5 is meshed with the partial gear formed on the outer peripheral wall of the magnet support wheel 8, and the magnet support wheel 8 rotates forward and backward by the arrangement pitch p of the magnets 12. It is possible.
[0021]
Both side walls 16 of the guide tube 5 are made of a thick stainless steel plate that is a ferromagnetic material such as 13 chromium (Cr) stainless steel, and the ferromagnetic portions 6 and the magnets 12 facing the magnets 12 on the side walls 16 are provided. By providing a narrow radial groove 30 at the boundary with the non-magnetic or weak magnetic part 6a that does not face each other, heating the part 6a of both side walls 16 to a temperature of 800 ° C. or higher to form a solution, and rapidly cooling from a high temperature state A non-magnetic or weakly magnetic austenitic phase. Preferably, grooves 30 are also provided on the outer surface of both side walls 16, and grooves 30a are provided on the outer peripheral surface and the inner peripheral surface, respectively, and the pair of grooves 30 and the pair of grooves 30a are nonmagnetic or weakly magnetic with the ferromagnetic portion 6. The boundary with the portion 6a is surrounded. Other configurations are the same as those of the embodiment of FIG.
[0022]
When the brakes are not braked, in an arrangement in which the polarities of the two magnets 12 adjacent in the circumferential direction with respect to the common ferromagnetic portion 6 are different from each other, as shown in FIG. z is generated and no magnetic field is applied to the brake disc 3. When the magnet support wheel 8 is rotated by the arrangement pitch p of the magnets 12 during braking, the polarities of the two magnets 12 facing the common ferromagnetic portion 6 are the same. Therefore, as shown in FIG. 7, the two magnets 12 equally apply a magnetic field to the pair of left and right brake disks 3 through the ferromagnetic portion 6. When the pair of rotating left and right braking disks 3 cross the magnetic field, an eddy current is generated in the pair of left and right braking disks 3, and the pair of left and right braking disks 3 receive a braking torque. At this time, from the magnet 12 to the ferromagnetic portion 6, the braking disk 3, the adjacent ferromagnetic portion 6, the adjacent magnet 12, the opposite ferromagnetic portion 6, the opposite braking disc 3, and the adjacent ferromagnetic portion 6. A magnetic circuit w is generated.
[0023]
The embodiment shown in FIG. 9 has two magnets 12 having the same polarity arranged in the circumferential direction in the embodiment shown in FIGS. Both side walls 16 of the guide tube 5 are made of a thick stainless steel plate, which is a ferromagnetic material such as 13 chromium (Cr) stainless steel, and the ferromagnetic portions 6 facing the magnets 12 on both side walls 16 and the magnets 12. A narrow radial groove 30 is provided at the boundary with the portion 6a that does not face the surface, and the portions 6a of both side walls 16 are heated to a temperature of 800 ° C. or more to form a solution, and then rapidly cooled from a high temperature state to be nonmagnetic or weak. Use magnetic austenite phase. Preferably, grooves 30 are also provided on the outer surface of both side walls 16, and grooves 30a are provided on the outer peripheral surface and the inner peripheral surface, respectively, and the pair of grooves 30 and the pair of grooves 30a are nonmagnetic or weakly magnetic with the ferromagnetic portion 6. The boundary with the portion 6a is surrounded. Other configurations are the same as those of the embodiment of FIG.
[0024]
One magnet 12 facing each ferromagnetic portion 6 of the side wall 16 of the guide tube 5 is coupled to the magnet support wheel 8 so that the polarities with respect to the ferromagnetic portion 6 are alternately different in the circumferential direction. By rotating the magnet support wheel 8 by the half arrangement pitch of the magnet 12, the two magnets 12 arranged in the circumferential direction on the ferromagnetic portion 6 of the side wall 16 of the guide cylinder 5 are partially opposed to each other so as to short-circuit the magnetic circuit z. And a braking position in which one magnet 12 entirely faces the ferromagnetic portion 6 of the side wall 16 of the guide cylinder 5 and forms a magnetic circuit with the braking disk 3. .
[0025]
【The invention's effect】
As described above, the present invention includes a pair of left and right brake discs coupled to a rotating shaft, a guide cylinder having a rectangular cross section disposed in a non-rotating portion between the pair of left and right brake discs, At least one magnet support wheel rotatably supported in the inner space of the guide tube, a number of magnets supported at equal intervals in the circumferential direction on the magnet support wheel, and each of the magnets provided on both side walls of the guide tube An eddy current reduction device having a ferromagnetic portion facing the magnet and generating a braking force on the braking disk by an eddy current based on a magnetic field from the magnet, wherein both side walls of the guide tube are made of a ferromagnetic material It is made of a thick stainless steel plate, leaving the ferromagnetic portions facing the magnets on both side walls as they are, and forming the portions not facing the magnets on both side walls as a solution so that they are non-magnetic or weak and magnetic, non-magnetic or Jaku磁of the two side walls Are those in which a portion between the ferromagnetic portion and a narrow radial groove width at the boundary of, is easy to manufacture configuration is simple guide tube, with substantially the same braking performance as the conventional structure can be obtained Manufacturing costs can be reduced.
[0026]
In addition, the groove at the boundary between the ferromagnetic part and the nonmagnetic or weakly magnetic part clearly distinguishes between the magnetic characteristics of both parts, so that a short circuit magnetic circuit during non-braking and a magnetic circuit during braking are efficiently formed. Leakage magnetic flux is reduced.
[0027]
An annular body made of a good conductor such as copper is coupled to at least one of the inner and outer peripheral edge portions that do not face the ferromagnetic portion of the brake disc. The eddy current flowing inside the brake disk is spread in the radial direction by the annular body, and the braking torque is increased.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an eddy current reduction device according to the present invention.
FIG. 2 is a plan sectional view showing the eddy current reduction device in a developed state.
FIG. 3 is a side sectional view of the eddy current reduction device.
FIG. 4 is a front sectional view of an eddy current reduction device according to a second embodiment of the present invention.
FIG. 5 is a plan sectional view showing the eddy current reduction device in a developed state.
FIG. 6 is a front sectional view of an eddy current reduction device according to a third embodiment of the present invention.
FIG. 7 is a plan sectional view showing an unbraking state of the eddy current reduction device.
FIG. 8 is a cross-sectional plan view showing a developed braking state of the eddy current reduction device.
FIG. 9 is a plan sectional view showing an unbraking state of an eddy current reduction device according to a fourth embodiment of the present invention.
[Explanation of symbols]
2: Rotating shaft 3: Brake disc 4: Bearing 5: Guide tube 6: Ferromagnetic part 6a: Non-magnetic or weakly magnetic part 8, 8a: Magnet support ring 9: Bearing 10, 10a: Magnet support ring 12, 12a: Magnet 13: Magnet 14: Sliding plate 16: Side wall 21: Outer cylinder 22: Inner cylinder 23: Annular body of good conductor 24: Annular body of good conductor 30, 30a: Groove

Claims

A pair of left and right brake discs coupled to the rotating shaft, a guide cylinder having an inner space with a rectangular cross section disposed in a non-rotating portion between the pair of left and right brake discs, At least one magnet support wheel that is movably supported, a large number of magnets supported on the magnet support ring at equal intervals in the circumferential direction, and a ferromagnetic portion facing each magnet provided on both side walls of the guide tube; An eddy current reduction device for generating a braking force on the braking disk by an eddy current based on a magnetic field from the magnet, wherein both side walls of the guide tube are made of a thick stainless steel plate that is a ferromagnetic material. , the magnet opposed to the ferromagnetic parts of the side walls is as it is, a non-magnetic or weakly magnetic by quenching from a high temperature state the magnet opposed to not portions of the side walls by solution, non of the two side walls with magnetic or weakly magnetic part and a ferromagnetic part Eddy current reduction apparatus characterized in that a narrow radial groove width to the field.

2. The eddy current reduction device according to claim 1, wherein an annular body made of a good conductor such as copper is provided on at least one of the inner and outer peripheral edge portions not facing the ferromagnetic portion of the brake disk.