JP3671621B2

JP3671621B2 - Magnetization method of permanent magnet type eddy current reduction device

Info

Publication number: JP3671621B2
Application number: JP28304497A
Authority: JP
Inventors: 徹桑原
Original assignee: Isuzu Motors Ltd
Current assignee: Isuzu Motors Ltd
Priority date: 1997-09-30
Filing date: 1997-09-30
Publication date: 2005-07-13
Anticipated expiration: 2017-09-30
Also published as: JPH11113224A

Description

【０００１】
【発明の属する技術分野】
本発明は大型貨物車両などに搭載される永久磁石式渦電流減速装置、特に渦電流減速装置の組立て後に永久磁石を磁石化する、永久磁石式渦電流減速装置の着磁方法に関するものである。
【０００２】
【従来の技術】
永久磁石（以下これを単に磁石という）を使用した渦電流減速装置では、磁性体からなる磁石支持環（継鉄）の外周面に、偶数個（８〜２４極）の磁石を外面の磁極が周方向に交互に異なるように、接着剤、取付金具（アルミニウム、ステンレス、合成樹脂などの非磁性材）などにより取り付けられている。磁石を着磁する時は、予め磁石を１個ずつ着磁するかまたは全部を同時に着磁してから磁石支持環に取り付けるか、着磁してない全部の磁石（厳密には希土類金属などの磁石材）を磁石支持環に接着剤、取付金具などにより取り付けてから、数個ずつ着磁するかまたは全部を同時に着磁していた。
【０００３】
しかし、磁石を１個ずつ着磁するのでは手間が掛かり、例えば全部で１２個の磁石を、磁石支持環の外周面に環状に並べて結合した後に、磁石支持環の外周側から磁界を付与して同時に着磁するのでは、手間は省けるものの、多数の強磁性板（ポールピース）を有する保護筒ないし案内筒の内部へ該磁石支持環を組み付ける時、案内筒に対する磁石の強力な吸引力に抗するため、剛性の高い強固な組付治具を必要とし、作業者が指などを怪我しないように細心の注意を要する。
【０００４】
なお、直流回転機のロータの着磁方法として、特開平2-133100号公報に開示されるようなものがあるが、この方法を永久磁石式渦電流減速装置の磁石支持環に適用しても上述の問題は解決できない。
【０００５】
【発明が解決しようとする課題】
本発明の課題は上述のような磁石支持環を案内筒へ組み付ける手間を省き、強固な組付治具を不要とするために、磁石を磁石支持環に結合しかつ案内筒に組み付けた後に着磁するようにした永久磁石式渦電流減速装置の着磁方法を提供することにある。
【０００６】
【課題を解決するための手段】
上記課題を解決するために、本発明の方法は永久磁石を用いて渦電流による制動力を発生させる渦電流減速装置において、磁性体からなる少なくとも１つの磁石支持環の外周面に着磁前の偶数個の永久磁石を周方向等間隔に結合し、非磁性体からなりかつ前記永久磁石と同数の強磁性板を周方向等間隔に有する案内筒の内部に前記磁石支持環を収容し、前記案内筒の各強磁性板に前記磁石支持環の各永久磁石が全面的に重なるように固定した後、各強磁性板の外面に対向する磁極を有する筒状の着磁装置により、前記磁石支持環の外周側から前記永久磁石に極性が周方向に交互に異なるように着磁し、前記案内筒の各強磁性板に前記磁石支持環の周方向に隣接しかつ極性が互いに異なる２つの永久磁石が重なるように前記磁石支持環を回動し、前記筒状の着磁装置から前記案内筒を引き出すことを特徴とする。
【０００７】
また、本発明の方法は永久磁石を用いて渦電流による制動力を発生させる渦電流減速装置において、磁性体からなる少なくとも１つの磁石支持環の外周面に着磁前の偶数個の永久磁石を周方向等間隔に結合し、非磁性体からなりかつ前記永久磁石の半数の強磁性板を周方向等間隔に有する案内筒の内部に前記磁石支持環を収容し、前記案内筒の各強磁性板に前記磁石支持環の２つの永久磁石がそれぞれ全面的に重なるように固定した後、各強磁性板の外面に対向する磁極を有する筒状の着磁装置により、前記磁石支持環の外周側から前記永久磁石に極性が周方向に２つずつ異なるように着磁し、前記案内筒の各強磁性板に前記磁石支持環の周方向に隣接しかつ極性が互いに異なる２つの永久磁石が重なるように前記磁石支持環を回動し、前記筒状の着磁装置から前記案内筒を引き出すことを特徴とする。
【００１０】
【発明の実施の形態】
本発明では磁石を着磁する前に、磁石を磁石支持環に結合したうえ案内筒の内部へ組み込み、次いで着磁装置の内部へ配置する。強磁性板のない非磁性体の薄板からなる案内筒の場合は、着磁装置の各磁極を案内筒の外側から各磁石へ対向させ、各磁極の電磁コイルに直流電流を流して着磁する。
【００１１】
多数の強磁性板を有する案内筒の場合は、予め各強磁性板に磁石支持環の各磁石が全面的に重なるように固定してから、着磁装置の内部へ配置する。着磁装置の各磁極を案内筒の外側から強磁性板へ対向させ、各磁心の電磁コイルに直流電流を流して着磁する。多数の強磁性板を有する案内筒の内部に２つ以上の磁石支持環が配設される場合は、各強磁性板に各磁石支持環の磁石が全面的に重なるように固定し、当該磁石が全部同極性となるように着磁する。上述の案内筒に収容した磁石支持環について、全部の磁石をまとめて同時に着磁しても、幾つかの磁石を数回に分けて順次着磁してもよい。
【００１２】
磁石支持環の磁石に着磁した後には、周方向に隣接する２つの磁石が案内筒の各強磁性板に部分的に重なるように磁石支持環を回動し、着磁装置から案内筒を引き出す。
【００１３】
【実施例】
図２は本発明が適用される永久磁石式渦電流減速装置の上半分を示す正面断面図、図３は同側面断面図である。本発明に係る永久磁石式渦電流減速装置は、電気導体からなる制動ドラム１３を回転軸４に結合される。このため、車両用変速機の歯車箱２の端壁に軸受３により支持されかつ端壁から突出する出力回転軸４に、スプライン孔５ａを有する取付フランジ５が嵌合され、かつ抜け出ないようにナツト６により締結される。取付フランジ５に駐車ブレーキの制動ドラム７の端壁と、渦電流減速装置の制動ドラム１３のボス部９と一体のフランジ部９ａとが重ね合され、複数のボルト１０とナツト１０ａにより締結される。
【００１４】
制動ドラム１３は鉄などの透磁率の大なる材料からなり、基端部をボス部９から放射方向へ延びる多数の支持腕（スポーク）１２に結合される。制動ドラム１３の外周壁には周方向等間隔に、多数の放熱フイン１３ａが備えられる。
【００１５】
制動ドラム１３の内部に、断面箱形の内空部１５を有する案内筒１８が同軸に配設される。非磁性体からなる不動の案内筒１８は、歯車箱２の突壁２ａに外嵌固定した枠板３１に、軸方向のボルト３２ａと径方向のボルト３２により固定される。案内筒１８は外周壁部１８ａと内周壁部１８ｂとの両端に環状の端壁板を結合して構成してもよいが、図示の案内筒１８は鉄などの磁性体からなる左半部の断面コ字形をなす筒部分と、アルミニウムなどの非磁性体からなる右半部の断面逆Ｌ字形をなす筒部分とを、多数のボルト１４により結合して構成される。
【００１６】
制動ドラム１３の内周面と対向する案内筒１８の外周壁部１８ａに、周方向等間隔に多数の開口が設けられ、各開口に強磁性板（ポールピース）２１が嵌合固定される。実際には、強磁性板２１は外周壁部１８ａをアルミニウムから鋳造する際に鋳ぐるまれる。
【００１７】
補強リブ３１ａを有する枠板３１に、周方向等間隔に複数のアクチユエータ（図示せず）が支持される。アクチユエータはシリンダにピストンを嵌合して１対の流体圧室を区画し、ピストンから案内筒１８の内空部１５へ突出するロツド１７の端部に磁石支持環１９を結合される。磁石支持環１９は案内筒１８の内空部１５に軸方向移動可能に支持される。磁石支持環１９の外周壁に、偶数個または４ｎ個（ｎは自然数）の強磁性板２１にそれぞれ対向する磁石２０が、極性が周方向に交互に異なるように結合される。
【００１８】
制動時、磁石支持環１９は図２，３に示すように、アクチユエータのロツド１７により制動ドラム１３の内部へ突出される。回転する制動ドラム１３が磁石２０から強磁性板２１を経て制動ドラム１３の内周面へ及ぶ磁界を横切る時、制動ドラム１３に渦電流が発生し、制動ドラム１３に制動トルクを及ぼす。この時、図３に示すように、磁石支持環１９と制動ドラム１３との間に磁気回路４０が形成される。制動ドラム１３は渦電流により発熱し、直接または放熱フイン１３ａを介して外気により冷却される。
【００１９】
非制動時、アクチユエータにより磁石支持環１９を図２の左方へ移動し、制動ドラム１３から引退させれば、磁石２０は制動ドラム１３へ磁界を及ぼさなくなり、制動ドラム１３は制動トルクを発生しない。上述のように、渦電流減速装置は磁石２０と制動ドラム１３の相対回転により発生する渦電流に基づく制動力を発生する。
【００２０】
図１に示すように、本発明は上述したような永久磁石式渦電流減速装置において、着磁する前の磁石２０（厳密には磁石材というべきもの）を磁石支持環１９に取付金具５４により結合してから、案内筒１８の内空部１５へ収容する。このため、予め磁石支持環１９を案内筒１８の内周壁部１８ｂへ嵌装してから、内周壁部１８ｂを外周壁部１８ａに多数のボルト１４（図２）により結合する。各磁石２０は断面台形をなすものであり、偶数個の磁石２０を磁石支持環１９の外周面に周方向等間隔に並べたうえ、磁石相互間に断面逆台形の非磁性体からなる取付金具５４を介装し、かつ各取付金具５４を貫通する複数のボルト５５を磁石支持環１９へ締結する。上述のようにして着磁前の磁石２０を結合した磁石支持環１９を案内筒１８の内部へ、各磁石２０が各強磁性板２１に全面的に重なるように収容し、次いで、案内筒１８を着磁装置５０の内部へ配置する。
【００２１】
着磁装置５０は磁性体からなる円筒形の継鉄５１の内周壁に、多数の磁心５３（磁石２０と同数）を周方向等間隔に配設し、各磁心５３に電磁コイル５２を巻装してなる。各磁心５３は継鉄５１の中心へ延びる、断面長方形のものであり、各磁心５３の先端つまり磁極５３ａの端面の周方向寸法と軸方向寸法は、強磁性板２１と同寸に形成される。
【００２２】
案内筒１８は各強磁性板２１が着磁装置５０の各磁極５３ａに重なるように配置され、また各磁石２０が各強磁性板２１に重なるように位置決めされる。次いで、周方向に相隣接する電磁コイル５２に互いに逆方向の直流電流を流すと、図１に矢印ｙで示すように磁気回路が発生する。すなわち、着磁用磁極５３ａから、強磁性板２１、磁石２０、磁石支持環１９、隣りの磁石２０、強磁性板２１、磁心５３、継鉄５１、隣りの磁心５３へと磁気回路ｙが生じ、磁石２０が着磁される。次いで、各電磁コイル５２への通電を停止し、案内筒１８に対して磁石支持環１９を磁石２０の配列ピツチの半分だけ回動すると、周方向に隣接する１対の磁石２０が共通の強磁性板２１に部分的に重なることになる。着磁された磁石２０が磁極５３ａに及ぼす吸引力が弱くなり、案内筒１８を着磁装置５０から簡単に引き出すことができ、強磁性板２１により案内筒１８の引き出し後の反磁界の発生が抑えられ、磁石２０は減磁を生じない。上述の実施例において、全部の磁石２０をまとめて着磁する代りに、幾つかの磁石２０を数回に分けて着磁してもよい。
【００２３】
多数の強磁性板２１を有する案内筒１８の内部に２つ以上の磁石支持環１９，１９ａが配設される場合は、各強磁性板２１に各磁石支持環１９，１９ａの磁石２０，２０ａを全面的に重ね合せ、当該磁石２０，２０ａを全部同極性に着磁する。すなわち、図４，５に示すように、断面箱形の内空部１５を有する案内筒１８の外周壁部１８ａに周方向等間隔に偶数個（２ｎ個、ｎは自然数）の強磁性板２１が結合される一方、内周壁部１８ｂには軸受２２ａにより磁石支持環１９ａが回動可能に支持され、磁石支持環１９ａの左半部の薄肉円筒部１９ｂに軸受２２により磁石支持環１９が回動可能に支持される。磁石支持環１９ａは薄肉円筒部１９ｂから案内筒１８の左端壁のスリツト２８を経て外方へ突出される腕２６を、アクチユエータ２４のピストンロツド２５に連結される。同様に、磁石支持環１９も案内筒１８の左端壁のスリツトを経て外方へ突出される腕を、別のアクチユエータのピストンロツドに連結される。アクチユエータ２４はシリンダ２７にピストンを嵌挿してなり、ピストンからピストンロツド２５が外部へ突出される。
【００２４】
図５に示すように、磁石支持環１９の外周面には各強磁性板２１に２個ずつ対向するように、４ｎ個の磁石２０が所定間隔を存して結合される。磁石支持環１９ａの外周面にも各強磁性板２１に２個ずつ対向するように、４ｎ個の磁石２０ａが所定間隔を存して結合される。
【００２５】
各磁石２０，２０ａを着磁させるには、図４に示すように、予め着磁してない磁石２０，２０ａを各磁石支持環１９，１９ａに結合し、かつ案内筒１８へそれぞれ回動可能に収容し、それぞれ２つの磁石２０，２０ａが全面的に各強磁性板２１に対向するように位置決めする。次いで、案内筒１８を着磁装置５０の内部へ、強磁性板２１が磁極５３ａに全面的に対向するように配置する。磁心５３に巻装した電磁コイル５２に、相隣接する磁心５３を通る磁界の方向が互いに逆になるように直流電流を流すと、図１に示す実施例と同様に各強磁性板２１に対向する４つの磁石２０，２０ａが同極に着磁される。
【００２６】
次いで、電磁コイル５２への通電を停止し、各磁石支持環１９，１９ａを磁石２０，２０ａの配列ピツチ分だけ回動すると、図５に示すように、各強磁性板２１に対向して周方向に並ぶ磁石２０，２０ａの極性が互いに逆になり、各強磁性板２１と各磁石支持環１９，１９ａとの間に短絡的磁気回路４０ａが生じ、磁石２０，２０ａが磁極５３ａに及ぼす吸引力が小さくなり、案内筒１８を着磁装置５０から容易に引き出すことができる。
【００２７】
図５は実際には制動ドラム１３の内部に案内筒１８が配設された渦電流式減速装置を示す。図示の非制動状態では、各強磁性板２１と磁石支持環１９，１９ａとの間に短絡的磁気回路４０ａが生じ、制動ドラム１３に制動力を及ぼさない。磁石支持環１９，１９ａを磁石２０，２０ａの配列ピツチ分だけ回動すると、各強磁性板２１に対向する４個の磁石２０，２０ａの極性が同じになり、磁石２０，２０ａの磁界が強磁性板２１を透過して回転する制動ドラム１３に作用し、渦電流に基づく制動力を制動ドラム１３に及ぼす。この時、４個の磁石２０，２０ａが図３に示す磁石２０と同じ働きをし、磁石支持環１９，１９ａと制動ドラム１３との間に磁気回路が形成される。
【００２８】
なお、本発明は上述の各実施例に限定されるものではなく、特願平7-336180号に開示されるような、強磁性板のない非磁性体からなる薄肉の案内筒の内部へ磁石支持環を収容してなる永久磁石式渦電流減速装置にも適用できる。この場合は、着磁装置の各磁極を薄肉の案内筒の外周側から磁石支持環の各磁石へ対向させ、各磁心の電磁コイルに直流電流を流して着磁する。着磁した後に着磁装置から案内筒を取り出すには、着磁装置から磁性体の筒体の内部へ案内筒を軸方向に移動する。
【００２９】
【発明の効果】
本発明は上述のように、永久磁石を用いて渦電流による制動力を発生させる渦電流減速装置において、磁性体からなる少なくとも１つの磁石支持環の外周面に着磁前の偶数個の永久磁石を周方向等間隔に結合し、非磁性体からなりかつ前記永久磁石と同数または半数の強磁性板を周方向等間隔に有する案内筒の内部に前記磁石支持環を収容し、前記案内筒の各強磁性板に前記磁石支持環の各永久磁石が全面的に重なるように固定した後、各強磁性板の外面に対向する磁極を有する筒状の着磁装置により、前記磁石支持環の外周側から前記永久磁石に極性が周方向に交互にまたは２つずつ異なるように着磁し、前記案内筒の各強磁性板に前記磁石支持環の周方向に隣接しかつ極性が互いに異なる２つの永久磁石が重なるように前記磁石支持環を回動し、前記筒状の着磁装置から前記案内筒を引き出すようにしたから次のような効果が得られる。
【００３０】
案内筒に対する磁石支持環の組付性が向上し、磁石支持環の組付けに当り作業者が指や手を傷つける心配がない。
【００３１】
磁石支持環の磁石に着磁した後には、周方向に隣接する２つの磁石が案内筒の強磁性板に部分的に重なる位置へ磁石支持環を回動すれば、磁石が着磁装置へ及ぼす吸引力が弱くなり、案内筒を着磁装置から容易に引き出すことができる。
【図面の簡単な説明】
【図１】本発明に係る往復動型永久磁石式渦電流減速装置の着磁方法を示す正面断面図である。
【図２】同渦電流式減速装置の側面断面図である。
【図３】同渦電流式減速装置の制動時の正面断面図である。
【図４】本発明に係る回動型永久磁石式渦電流減速装置の着磁方法を示す側面断面図である。
【図５】同渦電流式減速装置の非制動時の正面断面図である。
【符号の説明】
４：回転軸９：ボス部９ａ：フランジ部１２：支持腕１３：制動ドラム１３ａ：放熱フイン１４：ボルト１５：内空部１７：ロツド１８：案内筒１８ａ：外周壁部１８ｂ：内周壁部１９，１９ａ：磁石支持筒１９ｂ：薄肉円筒部２０，２０ａ：永久磁石２１：強磁性板２２，２２ａ：軸受２４：アクチユエータ２５：ロツド２６：腕２７：シリンダ２８：スリツト３１：枠板４０，４０ａ：磁気回路５０：着磁装置５１：継鉄５２：電磁コイル５３：磁心５３ａ：磁極５４：取付金具５５：ボルト[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a permanent magnet type eddy current reduction device mounted on a large freight vehicle or the like, and more particularly to a method for magnetizing a permanent magnet type eddy current reduction device in which a permanent magnet is magnetized after assembly of the eddy current reduction device.
[0002]
[Prior art]
In an eddy current reduction device using a permanent magnet (hereinafter simply referred to as a magnet), an even number (8 to 24 poles) of magnets are provided on the outer peripheral surface of a magnet support ring (a yoke) made of a magnetic material. It is attached with an adhesive, a mounting bracket (nonmagnetic material such as aluminum, stainless steel, synthetic resin) or the like so as to be alternately changed in the circumferential direction. When magnetizing magnets, magnets are magnetized one by one in advance, or all magnets are magnetized at the same time and then attached to the magnet support ring, or all magnets that are not magnetized (strictly, such as rare earth metals) After attaching the magnet material) to the magnet support ring with an adhesive, a mounting bracket, etc., several magnets were magnetized, or all were magnetized simultaneously.
[0003]
However, magnetizing magnets one by one is troublesome. For example, after a total of 12 magnets are arranged in a ring on the outer peripheral surface of the magnet support ring, a magnetic field is applied from the outer peripheral side of the magnet support ring. However, when magnetizing the magnet support ring inside the protective cylinder or guide cylinder having a large number of ferromagnetic plates (pole pieces), the magnet's strong attractive force with respect to the guide cylinder can be reduced. In order to resist it, a rigid and strong assembling jig is required, and careful attention is required so that the operator will not injure his finger.
[0004]
As a method for magnetizing a rotor of a DC rotating machine, there is one disclosed in Japanese Patent Laid-Open No. 2-133100. Even if this method is applied to a magnet support ring of a permanent magnet type eddy current reduction device, The above problem cannot be solved.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to eliminate the labor of assembling the magnet support ring as described above to the guide cylinder and eliminate the need for a strong assembling jig, and then attach the magnet to the magnet support ring and attach it after the assembly to the guide cylinder. It is an object of the present invention to provide a magnetizing method for a permanent magnet type eddy current reduction device that is magnetized.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the method of the present invention is an eddy current reduction device that generates a braking force due to an eddy current using a permanent magnet, and is arranged on the outer peripheral surface of at least one magnet support ring made of a magnetic material before magnetization. An even number of permanent magnets are coupled at equal intervals in the circumferential direction, the magnet support ring is accommodated in a guide tube made of a non-magnetic material and having the same number of ferromagnetic plates as the permanent magnets at equal intervals in the circumferential direction, The permanent magnets of the magnet support ring are fixed to the ferromagnetic plates of the guide cylinder so as to completely overlap, and then the magnet support is provided by a cylindrical magnetizing device having a magnetic pole facing the outer surface of each of the ferromagnetic plates. Two permanent magnets are magnetized from the outer peripheral side of the ring so that the polarities of the permanent magnets are alternately different in the circumferential direction, and are adjacent to the ferromagnetic plates of the guide tube in the circumferential direction of the magnet support ring and have different polarities. Rotate the magnet support ring so that the magnets overlap And wherein the withdrawing the guide tube from the tubular magnetizing apparatus.
[0007]
Further, the method of the present invention is an eddy current reduction device that generates a braking force by eddy current using a permanent magnet. An even number of permanent magnets before magnetization are provided on the outer peripheral surface of at least one magnet support ring made of a magnetic material. The magnet support ring is accommodated in a guide cylinder that is coupled at equal intervals in the circumferential direction and is made of a non-magnetic material and has half the ferromagnetic plates of the permanent magnets at equal intervals in the circumferential direction. After fixing the two permanent magnets of the magnet support ring on the plate so as to completely overlap each other, a cylindrical magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate, the outer peripheral side of the magnet support ring The permanent magnets are magnetized so that the polarities are different by two in the circumferential direction, and two permanent magnets that are adjacent in the circumferential direction of the magnet support ring and have different polarities overlap each ferromagnetic plate of the guide tube. Rotate the magnet support ring so that the Characterized in that from Jo polarizing device draw said guide cylinder.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, before magnetizing the magnet, the magnet is coupled to the magnet support ring and incorporated into the guide tube, and then disposed inside the magnetizing device. In the case of a guide tube made of a non-magnetic thin plate without a ferromagnetic plate, each magnetic pole of the magnetizing device is opposed to each magnet from the outside of the guide tube, and magnetized by flowing a direct current through the electromagnetic coil of each magnetic pole. .
[0011]
In the case of a guide cylinder having a large number of ferromagnetic plates, the magnets of the magnet support ring are fixed to each ferromagnetic plate in advance so as to entirely overlap, and then arranged inside the magnetizing device. Each magnetic pole of the magnetizing device is opposed to the ferromagnetic plate from the outside of the guide tube, and a direct current is passed through the electromagnetic coil of each magnetic core to magnetize it. When two or more magnet support rings are arranged inside a guide cylinder having a large number of ferromagnetic plates, the magnets of each magnet support ring are fixed to each ferromagnetic plate so as to be entirely overlapped, and the magnets Are magnetized so that they all have the same polarity. About the magnet support ring accommodated in the above-mentioned guide cylinder, all the magnets may be magnetized simultaneously, or several magnets may be magnetized sequentially in several times.
[0012]
After magnetizing the magnet of the magnet support ring, the magnet support ring is rotated so that two magnets adjacent in the circumferential direction partially overlap each ferromagnetic plate of the guide cylinder, and the guide cylinder is moved from the magnetizing device. Pull out.
[0013]
【Example】
FIG. 2 is a front sectional view showing the upper half of the permanent magnet type eddy current reduction device to which the present invention is applied, and FIG. 3 is a side sectional view of the same. In the permanent magnet type eddy current reduction device according to the present invention, a braking drum 13 made of an electric conductor is coupled to a rotating shaft 4. For this reason, the mounting flange 5 having the spline hole 5a is fitted to the output rotating shaft 4 supported by the bearing 3 on the end wall of the gear box 2 of the vehicle transmission and protruding from the end wall so that it does not come out. Fastened by nut 6. The end wall of the braking drum 7 of the parking brake and the boss 9 of the braking drum 13 of the eddy current speed reducing device 9 are integrated with the mounting flange 5 and are fastened by a plurality of bolts 10 and nuts 10a. .
[0014]
The brake drum 13 is made of a material having a high magnetic permeability such as iron, and the base end portion is coupled to a number of support arms (spokes) 12 extending in the radial direction from the boss portion 9. A large number of heat radiation fins 13 a are provided on the outer peripheral wall of the brake drum 13 at equal intervals in the circumferential direction.
[0015]
Inside the brake drum 13, a guide cylinder 18 having an inner space 15 having a box-shaped cross section is disposed coaxially. The stationary guide cylinder 18 made of a non-magnetic material is fixed to a frame plate 31 that is externally fitted and fixed to the protruding wall 2a of the gear box 2 by an axial bolt 32a and a radial bolt 32 . The guide tube 18 may be configured by connecting annular end wall plates to both ends of the outer peripheral wall portion 18a and the inner peripheral wall portion 18b. However, the illustrated guide tube 18 is formed on the left half portion made of a magnetic material such as iron. A cylindrical portion having a U-shaped cross section and a cylindrical portion having an inverted L-shaped cross section in the right half made of a nonmagnetic material such as aluminum are connected by a large number of bolts 14.
[0016]
A large number of openings are provided at equal intervals in the circumferential direction on the outer peripheral wall 18a of the guide cylinder 18 facing the inner peripheral surface of the brake drum 13, and a ferromagnetic plate (pole piece) 21 is fitted and fixed to each opening. Actually, the ferromagnetic plate 21 is cast when the outer peripheral wall portion 18a is cast from aluminum.
[0017]
A plurality of actuators (not shown) are supported on the frame plate 31 having the reinforcing ribs 31a at equal intervals in the circumferential direction. The actuator fits a piston into a cylinder to define a pair of fluid pressure chambers, and a magnet support ring 19 is coupled to the end of a rod 17 projecting from the piston to the inner space 15 of the guide tube 18. The magnet support ring 19 is supported by the inner space 15 of the guide tube 18 so as to be movable in the axial direction. Magnets 20 facing the even or 4n (n is a natural number) ferromagnetic plates 21 are coupled to the outer peripheral wall of the magnet support ring 19 so that the polarities are alternately different in the circumferential direction.
[0018]
At the time of braking, the magnet support ring 19 is protruded into the brake drum 13 by the rod 17 of the actuator as shown in FIGS. When the rotating brake drum 13 crosses the magnetic field extending from the magnet 20 through the ferromagnetic plate 21 to the inner peripheral surface of the brake drum 13, an eddy current is generated in the brake drum 13 and applies a braking torque to the brake drum 13. At this time, as shown in FIG. 3, a magnetic circuit 40 is formed between the magnet support ring 19 and the brake drum 13. The brake drum 13 generates heat by eddy current, and is cooled by outside air directly or through the heat radiation fin 13a.
[0019]
During non-braking, if the magnet support ring 19 is moved to the left in FIG. 2 by the actuator and retracted from the braking drum 13, the magnet 20 does not exert a magnetic field on the braking drum 13, and the braking drum 13 does not generate braking torque. . As described above, the eddy current reduction device generates a braking force based on the eddy current generated by the relative rotation of the magnet 20 and the braking drum 13.
[0020]
As shown in FIG. 1, in the permanent magnet type eddy current reduction device as described above, the present invention is configured such that a magnet 20 before magnetizing (strictly speaking, a magnet material) is attached to a magnet support ring 19 by a mounting bracket 54. After being combined, the guide tube 18 is accommodated in the inner space 15. For this reason, after the magnet support ring 19 is fitted in the inner peripheral wall portion 18b of the guide cylinder 18 in advance, the inner peripheral wall portion 18b is coupled to the outer peripheral wall portion 18a by a large number of bolts 14 (FIG. 2). Each magnet 20 has a trapezoidal cross section, and an even number of magnets 20 are arranged on the outer peripheral surface of the magnet support ring 19 at equal intervals in the circumferential direction, and a mounting bracket made of a nonmagnetic material having a reverse trapezoidal cross section between the magnets. A plurality of bolts 55 that interpose 54 and penetrate each mounting bracket 54 are fastened to the magnet support ring 19. As described above, the magnet support ring 19 to which the magnets 20 before magnetization are coupled is accommodated inside the guide cylinder 18 so that each magnet 20 overlaps each ferromagnetic plate 21, and then the guide cylinder 18. Is placed inside the magnetizing device 50.
[0021]
The magnetizing device 50 has a large number of magnetic cores 53 (the same number as the magnets 20) arranged at equal intervals in the circumferential direction on the inner peripheral wall of a cylindrical yoke 51 made of a magnetic material, and an electromagnetic coil 52 is wound around each magnetic core 53. Do it. Each magnetic core 53 has a rectangular cross section extending to the center of the yoke 51, and the circumferential dimension and the axial dimension of the tip of each magnetic core 53, that is, the end face of the magnetic pole 53 a, are formed to be the same as those of the ferromagnetic plate 21. .
[0022]
The guide cylinder 18 is disposed so that each ferromagnetic plate 21 overlaps each magnetic pole 53 a of the magnetizing device 50, and is positioned so that each magnet 20 overlaps each ferromagnetic plate 21. Next, when direct currents in opposite directions are passed through the electromagnetic coils 52 adjacent to each other in the circumferential direction, a magnetic circuit is generated as shown by an arrow y in FIG. That is, a magnetic circuit y is generated from the magnetizing magnetic pole 53a to the ferromagnetic plate 21, the magnet 20, the magnet support ring 19, the adjacent magnet 20, the ferromagnetic plate 21, the magnetic core 53, the yoke 51, and the adjacent magnetic core 53. The magnet 20 is magnetized. Next, when the energization of each electromagnetic coil 52 is stopped and the magnet support ring 19 is rotated by half of the arrangement pitch of the magnets 20 with respect to the guide cylinder 18, a pair of magnets 20 adjacent in the circumferential direction have a common strength. The magnetic plate 21 partially overlaps. The attracting force exerted on the magnetic pole 53a by the magnetized magnet 20 becomes weak, the guide tube 18 can be easily pulled out from the magnetizing device 50, and the ferromagnetic plate 21 generates a demagnetizing field after the guide tube 18 is pulled out. The magnet 20 is not demagnetized. In the above-described embodiment, instead of magnetizing all the magnets 20 together, several magnets 20 may be magnetized in several times.
[0023]
When two or more magnet support rings 19, 19 a are arranged inside the guide cylinder 18 having a large number of ferromagnetic plates 21, the magnets 20, 20 a of the magnet support rings 19, 19 a are arranged on each ferromagnetic plate 21. And magnets 20 and 20a are all magnetized to the same polarity. That is, as shown in FIGS. 4 and 5, an even number (2n, n is a natural number) of ferromagnetic plates 21 at equal intervals in the circumferential direction on the outer peripheral wall portion 18 a of the guide tube 18 having the inner space 15 having a box-shaped cross section. The magnet support ring 19a is rotatably supported by the bearing 22a on the inner peripheral wall portion 18b, and the magnet support ring 19 is rotated by the bearing 22 on the thin cylindrical portion 19b in the left half of the magnet support ring 19a. It is supported movably. The magnet support ring 19a is connected to the piston rod 25 of the actuator 24 with the arm 26 protruding outward from the thin cylindrical portion 19b through the slit 28 on the left end wall of the guide tube 18. Similarly, the magnet support ring 19 is connected to the piston rod of another actuator with the arm protruding outward through the slit of the left end wall of the guide tube 18. The actuator 24 is formed by inserting a piston into the cylinder 27, and the piston rod 25 projects outward from the piston.
[0024]
As shown in FIG. 5, 4n magnets 20 are coupled to the outer peripheral surface of the magnet support ring 19 at a predetermined interval so as to face two ferromagnetic plates 21. 4n magnets 20a are coupled to each of the outer peripheral surfaces of the magnet support ring 19a so as to face each of the ferromagnetic plates 21 at a predetermined interval.
[0025]
In order to magnetize the magnets 20 and 20a, as shown in FIG. 4, the magnets 20 and 20a that are not magnetized in advance are coupled to the magnet support rings 19 and 19a and can be rotated to the guide cylinder 18, respectively. The two magnets 20 and 20a are positioned so as to face the respective ferromagnetic plates 21 entirely. Next, the guide tube 18 is disposed inside the magnetizing device 50 so that the ferromagnetic plate 21 is completely opposed to the magnetic pole 53a. When a direct current is applied to the electromagnetic coil 52 wound around the magnetic core 53 so that the directions of the magnetic fields passing through the adjacent magnetic cores 53 are opposite to each other, the respective ferromagnetic plates 21 are opposed to each other as in the embodiment shown in FIG. The four magnets 20 and 20a are magnetized to the same polarity.
[0026]
Next, when the energization of the electromagnetic coil 52 is stopped and the magnet support rings 19 and 19a are rotated by the arrangement pitches of the magnets 20 and 20a, the peripheral surfaces of the magnets 21 face each other as shown in FIG. The polarities of the magnets 20 and 20a arranged in the direction are opposite to each other, a short-circuit magnetic circuit 40a is generated between each ferromagnetic plate 21 and each magnet support ring 19 and 19a, and the magnet 20 and 20a attracts the magnetic pole 53a. The force is reduced, and the guide tube 18 can be easily pulled out from the magnetizing device 50.
[0027]
FIG. 5 shows an eddy current type speed reducer in which a guide cylinder 18 is actually arranged inside the brake drum 13. In the illustrated non-braking state, a short-circuit magnetic circuit 40 a is generated between each ferromagnetic plate 21 and the magnet support rings 19, 19 a, and no braking force is exerted on the braking drum 13. When the magnet support rings 19 and 19a are rotated by the arrangement pitch of the magnets 20 and 20a, the polarities of the four magnets 20 and 20a facing the ferromagnetic plates 21 are the same, and the magnetic fields of the magnets 20 and 20a are strong. It acts on the brake drum 13 that rotates through the magnetic plate 21, and applies a braking force based on the eddy current to the brake drum 13. At this time, the four magnets 20, 20 a function in the same manner as the magnet 20 shown in FIG. 3, and a magnetic circuit is formed between the magnet support rings 19, 19 a and the brake drum 13.
[0028]
The present invention is not limited to the above-described embodiments, and a magnet is inserted into a thin guide tube made of a non-magnetic material without a ferromagnetic plate as disclosed in Japanese Patent Application No. 7-336180. The present invention can also be applied to a permanent magnet type eddy current reduction device that houses a support ring. In this case, each magnetic pole of the magnetizing device is opposed to each magnet of the magnet support ring from the outer peripheral side of the thin guide tube, and magnetized by flowing a direct current through the electromagnetic coil of each magnetic core. In order to take out the guide tube from the magnetizing device after magnetization, the guide tube is moved in the axial direction from the magnetizing device to the inside of the magnetic cylinder.
[0029]
【The invention's effect】
As described above, the present invention provides an eddy current reduction device that generates a braking force by an eddy current using a permanent magnet, and an even number of permanent magnets before magnetization on the outer peripheral surface of at least one magnet support ring made of a magnetic material. The magnet support ring is accommodated in a guide cylinder made of a non-magnetic material and having the same or half ferromagnetic plates as the permanent magnet at equal intervals in the circumferential direction. After fixing the permanent magnets of the magnet support ring to each ferromagnetic plate so as to overlap the entire surface, the outer periphery of the magnet support ring is formed by a cylindrical magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate. From the side, the permanent magnets are magnetized so that the polarities are alternately or two different in the circumferential direction, and the two ferromagnetic plates of the guide cylinder are adjacent to each other in the circumferential direction of the magnet support ring and have different polarities. The magnet support ring so that the permanent magnets overlap. Dynamic and, effects such as the following are obtained from the from the tubular magnetizing apparatus to draw the guide tube.
[0030]
Assembling property of the magnet support ring to the guide cylinder is improved, and there is no fear that an operator may hurt a finger or a hand when assembling the magnet support ring.
[0031]
After magnetizing the magnet of the magnet support ring, if the magnet support ring is rotated to a position where two magnets adjacent in the circumferential direction partially overlap the ferromagnetic plate of the guide tube, the magnet exerts on the magnetizing device. The attraction force becomes weak and the guide tube can be easily pulled out from the magnetizing device.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a magnetization method of a reciprocating permanent magnet eddy current reduction device according to the present invention.
FIG. 2 is a side sectional view of the eddy current type speed reducer.
FIG. 3 is a front sectional view of the eddy current type speed reducer during braking.
FIG. 4 is a side sectional view showing a magnetization method of the rotating permanent magnet type eddy current reduction device according to the present invention.
FIG. 5 is a front cross-sectional view of the eddy current type speed reducer during non-braking.
[Explanation of symbols]
4: Rotating shaft 9: Boss portion 9a: Flange portion 12: Support arm 13: Braking drum 13a: Radiation fin 14: Bolt 15: Inner space portion 17: Rod 18: Guide tube 18a: Outer peripheral wall portion 18b: Inner peripheral wall portion 19 19a: Magnet support tube 19b: Thin cylindrical portion 20, 20a: Permanent magnet 21: Ferromagnetic plate 22, 22a: Bearing 24: Actuator 25: Rod 26: Arm 27: Cylinder 28: Slit 31: Frame plate 40, 40a: Magnetic circuit 50: Magnetizing device 51: yoke 52: electromagnetic coil 53: magnetic core 53a: magnetic pole 54: mounting bracket 55: bolt

Claims

In an eddy current reduction device that generates a braking force by an eddy current using a permanent magnet, an even number of permanent magnets before magnetization are coupled to the outer peripheral surface of at least one magnet support ring made of a magnetic material at equal intervals in the circumferential direction. The magnet support ring is housed in a guide tube made of a non-magnetic material and having the same number of ferromagnetic plates as the permanent magnets at equal intervals in the circumferential direction, and the magnet support ring is placed on each ferromagnetic plate of the guide tube. After fixing the permanent magnets so as to overlap with each other, the cylindrical magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate causes the permanent magnet to have a polarity in the circumferential direction from the outer peripheral side of the magnet support ring. The magnet support ring is rotated so that two permanent magnets adjacent to each other in the circumferential direction of the magnet support ring and having different polarities overlap each ferromagnetic plate of the guide cylinder. Pull the guide tube from the cylindrical magnetizing device. It characterized Succoth, magnetizing method of the permanent magnet type eddy current reduction apparatus.

In an eddy current reduction device that generates a braking force by an eddy current using a permanent magnet, an even number of permanent magnets before magnetization are coupled to the outer peripheral surface of at least one magnet support ring made of a magnetic material at equal intervals in the circumferential direction. The magnet support ring is housed in a guide tube made of a non-magnetic material and having half the ferromagnetic plates of the permanent magnet at equal intervals in the circumferential direction, and the magnet support ring is placed on each ferromagnetic plate of the guide tube. After fixing the two permanent magnets so as to overlap each other, the permanent magnet is polarized from the outer peripheral side of the magnet support ring by a cylindrical magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate. The magnet support ring is magnetized so as to be different two by two in the circumferential direction, and the two permanent magnets adjacent to each other in the circumferential direction of the magnet support ring and having different polarities overlap each ferromagnetic plate of the guide cylinder. Rotate and forward from the cylindrical magnetizer Characterized in that withdrawing the guide tube, magnetizing method of the permanent magnet type eddy current reduction apparatus.