JP4001051B2

JP4001051B2 - Eddy current reduction device and magnet guide case used therefor

Info

Publication number: JP4001051B2
Application number: JP2003126614A
Authority: JP
Inventors: 博行山口; 憲治今西; 誠均田坂; 泰隆野口; 光雄宮原
Original assignee: Sumitomo Metal Industries Ltd
Current assignee: Nippon Steel Corp
Priority date: 2003-05-01
Filing date: 2003-05-01
Publication date: 2007-10-31
Anticipated expiration: 2023-05-01
Also published as: JP2004336850A

Description

【０００１】
【産業上の利用分野】
本発明は、渦電流式減速装置に関し、特に、機関の回転軸に連結した制動ディスクに対して永久磁石を近接、離間させるタイプの渦電流式減速装置の改良に関する。
【０００２】
【従来の技術】
トラック等の大型車両の補助ブレーキ等に使用される渦電流式減速装置には、いくつかのタイプがある。機関の回転軸に連結した制動部材の形状に着目すると、ディスク状の制動部材を採用するタイプ（ディスクタイプ）と、ドラム状の制動部材を採用するタイプに大別される。また、磁気を発生する構成に着目すると、永久磁石を用いたもの、電磁石を用いたもの、更には永久磁石と電磁石の両方を用いた所謂ハイブリッドタイプに大別される。
【０００３】
【発明が解決しようとする課題】
何れのタイプの渦電流式減速装置においても、制動効率の向上及び装置の小型が常に重要な課題となる。例えば、永久磁石を用いたディスクタイプの渦電流式減速装置においては、制動時に制動ディスクに接近する永久磁石の温度が上昇する。永久磁石の温度が上昇すると、磁石の磁力が低下し、制動効率が低下してしまう。逆に、磁石の温度上昇を抑制するために制動時の永久磁石と制動ディスクとの間隔を大きめにすると、磁力線の磁路長がながくなり、制動効率が低下してしまう。
【０００４】
また、非制動時に永久磁石を制動ディスクから待避されている状態で磁気漏れが発生し、制動ディスクに磁界が作用する場合がある。こうなると、非制動状態でありながら回転軸に微小な制動力が作用してしまう。これを回避するために、非制動時に永久磁石を制動ディスクから大きく引き離す構造を採ることが考えられる。しかし、この場合には、制動時・非制動時における永久磁石の移動ストロークが大きくなり、装置全体が大型化してしまう。
【０００５】
本発明は、上記のような状況に鑑みて成されたものであり、制動効率の向上及び装置の小型化に寄与する渦電流式減速装置を提供することを第１の目的とする。
【０００６】
また、制動効率の向上及び装置の小型化に寄与する渦電流式減速装置用の磁石ケースを提供することを第２の目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、本発明の第１の態様に係る渦電流式減速装置は、機関の回転軸に連結された制動部材と；制動時に前記制動部材の制動面に対して磁界を作用させる磁界発生部と；前記磁界発生部を前記制動部材の制動面に対して制動と非制動とをスイッチさせる機構と；前記磁界発生部材と前記制動面との間に配置され、前記制動面全面に対向する中間薄板部材とを備える。そして、前記中間薄板部材が、高熱伝導率を有する第１の部材と軟磁性の第２の部材とを、各部材が磁極面と平行になるように貼り合わせた構造とする。
【０００８】
ここで、高熱伝導率とは、一般的な軟磁性材料が持つ熱伝導率よりも高い熱伝導率をいう。また、軟磁性とは、高い透磁率を持ちながら保持力が小さい磁性材料の性質をいい、一般的な非磁性材と永久磁石を除く殆どの磁性材料の性質でもある。また、中間薄板部材とは、制動時に磁界発生部材から出る磁束により当該薄板の軟磁性材内部に生じる磁気短絡回路の磁束が飽和する最大の厚さよりも薄い板厚を有する軟磁性材に、高熱伝導率材が少なくとも必要な熱伝導率を確保できるだけの厚さを有するものを積層したものをいう。
【０００９】
また、本発明の第２の態様に係る磁石ケースは、強磁性体からなり、機関の回転軸に連結された制動ディスクと；制動時に前記制動部材の制動面に対して磁界を作用させる複数の永久磁石と；前記永久磁石を前記制動部材の制動面に対して接近、離間させる駆動機構とを備えた渦電流式減速装置に使用され、前記永久磁石を移動可能な状態で収容するケースに適用される。そして、少なくとも前記制動ディスクの制動面に対向する端部全面が、高熱伝導率を有する第１の部材と軟磁性の第２の部材とを貼り合わせた構造の部材で構成される。
【００１０】
上述したように、本発明によれば、永久磁石等の磁界発生部材と制動部材との間に配置される中間薄板部材に熱伝導率の高い材料を用いているため、制動部材から発生する熱が中間薄板部材を介して外部に放熱され易くなる。その結果、磁石と制動部材との距離を短くすることができ、制動効率の向上に寄与することになる。
【００１１】
また、中間薄板部材の材質を軟磁性体としているため、非制動時に磁石から中間薄板部材を通して制動部材に到達する磁束量を低減することができる。これにより、磁気漏れ損失が問題とならない磁石と制動部材との距離が、非磁性材の中間薄板部材を使用した場合に比べ短くできる。その結果、永久磁石等の磁界発生部材を用いた場合に移動ストロークが短くなり、装置を小型化することが可能となる。なお、制動中においては、中間薄板部材に磁石が近接し、非制動時に比べ中間薄板部材の磁束密度は極端に大きくなるため、飽和磁束密度の小さい軟磁性の中間薄板部材では磁気短絡することがなく、非磁性体の中間薄板部材と比較して制動効率の低下は殆ど無い。
【００１２】
【発明の実施の形態】
以下、本発明についてディスク状の制動部材に対して永久磁石を近接、離間させるタイプの渦電流式減速装置を一例に説明する。しかし、本発明の技術的思想は、制動部材の形状及び磁気発生部の方式等に限定されず、磁気発生部の温度上昇及び装置の小型が要求される種々のタイプの渦電流式減速装置に適用可能である。すなわち、ドラム状の制動部材を用い、あるいは、電磁石又は電磁石と永久磁石とを組み合わせた磁石等を磁気発生部として採用した渦電流式減速装置等にも適用可能である。
【００１３】
図１及び図２は、第１参考例に係るリターダの要部の構造を示す断面図であり、各々、図１が非制動状態、図２が制動状態を示す。本実施例に係る渦電流式減速装置（リターダ）は、機関の回転軸１に対して固定された強磁性体からなる制動ディスク２と；制動ディスク２の近傍に配置される制動ユニット（３〜７）とを備えている。
【００１４】
回転軸１は、例えば、大型車両（トラック）のプロペラシャフトに連結される。制動ディスク２は円盤（ディスク）状に成形され、中心部を回転軸１が貫通する格好で配置される。制動ユニットは、制動用の磁界を発生する複数の永久磁石６と；当該永久磁石６を保持するリング状又は円弧状の保持部材４と；これら永久磁石６及び保持部材４を収容するケース３と；保持部材４に連結され、永久磁石６を制動ディスク２に対して近接、離間移動させるための駆動機構（エアシリンダー）５と；ケース３の制動ディスク２側端部に配置されたカバー（中間薄板部材）７とを備えている。
【００１５】
制動ディスク２は強磁性体によって成形され、図の左側面が制動面として機能する。永久磁石６は、保持部材４の表面上に円周方向に所定間隔で複数配置される。カバー７は、熱伝導率が高く、且つ軟磁性の材料によって成形する。ここで、カバー７の熱伝導率としては、少なくとも１０Ｗ／（ｍ・ｋ）以上が適切であり、３０Ｗ／（ｍ・ｋ）以上がより好ましい。また、カバー７の磁性は、磁界強度１００００Ａ／ｍにおける微分透磁率より規定した真空に対する比透磁率（μｓ）で１０以上、１３０以下が好ましい。この値が１０より小さいと常磁性又は非磁性の領域となってしまい、１３０より大きい場合にはカバー７内にできる磁気短絡回路にまわる磁束が増加し、制動力の低下につながる。
【００１６】
カバー７は、プレスや鋳造加工によってケース（案内筒）３と一体で成形することも可能である。カバー７をケース３と別部材とする場合には、ビス止め、カシメ、圧入、接着、溶接などの方法によって、当該カバー７をケース３に対して固定することができる。また、カバー７の断面形状は、一様である必要はなく、磁石と対向しない部分を厚く成形したり、部分的にリブを設けて補強しても良い。
【００１７】
また，カバー７の厚さが厚いほど非制動時の磁気漏れ量は低減し、磁石６の温度上昇量も低減するが、磁石６とディスクとの距離が長くなるので、制動効率が低下する。従って，カバー７の厚さは、磁気漏れ抑制効果と磁石温度上昇抑制効果及び制動効率から最適値を決める。厚さの最適値は、カバー７の磁気的特性と熱伝導率だけでなく、磁石の温度特性によってもかわるので、これらを考慮して決定する。
【００１８】
ケース３は、例えば、アルミニウム、アルミニウム合金、炭素鋼、鋳鉄、ステンレス鋼等の材質によって成形することが望ましい。
【００１９】
本参考例の渦電流式減速装置において、図１に示すように、非制動時には、永久磁石６が制動ディスク２から遠ざかる方向に移動（退避）する。本参考例においては、カバー７の材質を軟磁性体としているため、非制動時に磁石６からカバー７を通して制動ディスク２に到達する磁束量を低減することができる。これにより、磁気漏れ損失が問題とならない磁石と制動部材との距離が、非磁性材のカバーを使用した場合に比べ短くできる。その結果、永久磁石６の移動ストロークが短くなり、装置を小型化することが可能となる。
【００２０】
なお、制動中においては、カバー７が薄くて飽和磁束密度が小さいために、カバー７に磁石が近接し、磁束が大きくなり、カバー７内部で磁気短絡を生じても磁気短絡回路に回る磁束が非常に少ないので、非磁性体のカバーと比較して制動効率の低下は殆ど無い。
【００２１】
一方、制動時には、図２に示すように、永久磁石６が制動ディスク２に接近し、磁束を作用させる。ところで、制動時には制動ディスク２で発生した熱が永久磁石６側に伝わるが、本参考例においては、カバー７が熱伝導率の高い材質で成形されているため、図３に示すように、制動ディスク２で発生した熱は当該カバー７を介して外部に放熱され易くなる。このため、永久磁石６の温度上昇を低減するために、制動時の磁石６と制動ディスク２との間隔を必要以上に大きくする事態を回避でき、その結果、制動効率の向上を図ることが可能となる。
【００２２】
図４は、本発明の第１実施例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。本実施例において、上述した参考例と同一又は対応する構成要素については、同一の符号を付し、重複した説明は省略する。
【００２３】
本実施例においては、カバー７を熱伝導率が高い材料からなる第１部材７ａと、軟磁性の材料からなる第２部材７ｂを貼り合わせた構成（クラッド構造）としている。そして、第２部材７ｂを制動ディスク２側、第１部材７ａを永久磁石６側に配置している。ここで、第１部材７ａと第２部材７ｂの位置を反対とし、第１部材７ａを制動ディスク２側、第２部材７ｂを永久磁石６側に配置しても同様な効果が期待できる。
【００２４】
また、カバー７の熱膨張による変形を考慮し、熱伝導率の高い部材（７ａ）を軟磁性の部材（７ｂ）で挟み込む、あるいは、逆に軟磁性の部材（７ｂ）を熱伝導率の高い部材（７ａ）で挟み込む構造を採ることができる。このようなサンドイッチ構造にすれば、カバー７が熱膨張した場合にも一方向への偏った反り等の変形を抑制することができる。
【００２５】
第１部材７ａに使用される熱伝導率の高い材料としては、軟磁性材料よりも高い熱伝導率を有するアルミニウム、アルミニウム合金、銅、黄銅などの銅合金、マグネシウム、マグネシウム合金などがある。また、これらの材料を主成分として他の物質を添加することもできる。熱伝導率の最も望ましい値としては、１００Ｗ／（ｍ・ｋ）以上を有する程度である。
【００２６】
一方、第２部材７ｂに使用される軟磁性材としては、オーステナイト系ステンレス鋼、フェライト系ステンレス鋼や、二相ステンレス鋼などがある。第２部材７ｂの磁界強度１００００Ａ／ｍにおける微分透磁率より規定した真空に対する比透磁率（μｓ）としては、１０≦μｓ≦１３０が望ましい。なお、一般にオーステナイト系ステンレス鋼は冷間加工を施していない場合、磁気的性質が悪い（透磁率が低い）ため、非磁性材料に分類される場合があるが、冷間加工を施すことにより、マルテンサイト相が誘起され、透磁率が高くなり、本発明でいう軟磁性材料となる。
【００２７】
要するに、本発明における軟磁性材料としては、オーステナイト系ステンレス鋼やフェライト系ステンレス鋼であり、且つ比透磁率（μｓ）が１０≦μｓ≦１３０であるものが最も望ましい。なお、フェライト系ステンレス鋼においては、クロム（Ｃｒ）の含有量を調整することにより、上記のような望ましい比透磁率を得ることが可能である。
【００２８】
本実施例においても、第１参考例と同様の作用効果を得ることができる。
【００２９】
図５は、本発明の第２実施例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。本実施例において、上述した参考例及び実施例と同一又は対応する構成要素については、同一の符号を付し、重複した説明は省略する。
【００３０】
本実施例は、図４に示した第１実施例の応用であり、カバー７をクラッド構造ではなく、全く別の２つの独立した部材によって構成する。そして、永久磁石６側の第２部材７ｂをケース３に対して固定した後に、制動ディスク２側の第１部材を第２部材７ｂの上から覆うように固定する。特性の異なる第１部材７ａ及び第２部材７ｂを全く別の部材とすることにより、装置の使用条件や状況に応じて種々の組み合わせを選択することが可能となる。
【００３１】
また、カバー７の熱膨張による変形を考慮し、熱伝導率の高い部材（７ａ）を軟磁性の部材（７ｂ）で挟み込む、あるいは、逆に軟磁性の部材（７ｂ）を熱伝導率の高い部材（７ａ）で挟み込む構造を採ることができる。このようなサンドイッチ構造にすれば、カバー７が熱膨張した場合にも一方向への偏った反り等の変形を抑制することができる。
【００３２】
図６は、第２参考例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。また、図７は、図６におけるＡ−Ａ方向の断面の一部を示す。本参考例において、上述した各実施例と同一又は対応する構成要素については、同一の符号を付し、重複した説明は省略する。
【００３３】
本参考例においては、軟磁性の第２部材７ｂを永久磁石６と対向しないように部分的に配置し、非磁性（高熱伝導率）の第１部材のみが永久磁石６に対向する構成としている。本実施例によれば、磁石６と制動ディスク２との距離を短くすることができ、一層制動効率が高くなる。なお、非制動時の磁気漏れに関しては、軟磁性の第２部材７ｂの厚さを厚くすることにより、対応することができる。
【００３４】
以上、本発明の実施例（実施形態、実施態様）について説明したが、本発明はこれらの実施例に何ら限定されるものではなく、特許請求の範囲に示された技術的思想の範疇において変更可能なものである。
【図面の簡単な説明】
【図１】図１は、第１参考例に係るリターダの要部の構造を示す断面図であり、非制動状態を示す。
【図２】図２は、第１参考例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。
【図３】図３は、第１参考例に係るリターダの制動時の放熱状態を示す説明図（断面図）である。
【図４】図４は、本発明の第１実施例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。
【図５】図５は、本発明の第２実施例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。
【図６】図６は、第２参考例に係るリターダの要部の構造を示す断面図であり、制動状態を示す。
【図７】図７は、図６におけるＡ−Ａ方向の断面の一部を示す。[0001]
[Industrial application fields]
The present invention relates to an eddy current type reduction device, and more particularly to an improvement of an eddy current type reduction device in which a permanent magnet is brought close to and away from a braking disk connected to a rotating shaft of an engine.
[0002]
[Prior art]
There are several types of eddy current type speed reducers used for auxiliary brakes of large vehicles such as trucks. Focusing on the shape of the braking member connected to the rotating shaft of the engine, it is roughly divided into a type that employs a disc-shaped braking member (disc type) and a type that employs a drum-shaped braking member. Focusing on the configuration that generates magnetism, it is roughly divided into those using permanent magnets, those using electromagnets, and so-called hybrid types using both permanent magnets and electromagnets.
[0003]
[Problems to be solved by the invention]
In any type of eddy current type reduction gear, improvement of braking efficiency and downsizing of the device are always important issues. For example, in a disk type eddy current type speed reducer using a permanent magnet, the temperature of the permanent magnet approaching the braking disk rises during braking. When the temperature of the permanent magnet increases, the magnetic force of the magnet decreases, and the braking efficiency decreases. On the other hand, if the distance between the permanent magnet and the braking disk during braking is increased in order to suppress the temperature rise of the magnet, the magnetic path length of the magnetic lines of force is reduced, and the braking efficiency is reduced.
[0004]
In addition, magnetic leakage may occur when the permanent magnet is retracted from the brake disk during non-braking, and a magnetic field may act on the brake disk. If this happens, a minute braking force will act on the rotating shaft in the non-braking state. In order to avoid this, it is conceivable to adopt a structure in which the permanent magnet is largely separated from the braking disk during non-braking. However, in this case, the movement stroke of the permanent magnet at the time of braking / non-braking becomes large, and the entire apparatus becomes large.
[0005]
The present invention has been made in view of the above situation, and a first object of the present invention is to provide an eddy current reduction device that contributes to improvement in braking efficiency and downsizing of the device.
[0006]
It is a second object of the present invention to provide a magnet case for an eddy current reduction device that contributes to improvement of braking efficiency and downsizing of the device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an eddy current type speed reducer according to a first aspect of the present invention includes a braking member coupled to a rotating shaft of an engine; and a magnetic field acting on a braking surface of the braking member during braking. A magnetic field generating unit that causes the magnetic field generating unit to switch between braking and non-braking with respect to a braking surface of the braking member; and disposed between the magnetic field generating member and the braking surface, the entire braking surface And an intermediate thin plate member opposite to each other . The intermediate thin plate member has a structure in which a first member having high thermal conductivity and a soft magnetic second member are bonded to each other so that each member is parallel to the magnetic pole surface .
[0008]
Here, the high thermal conductivity means a thermal conductivity higher than that of a general soft magnetic material. Soft magnetism means a property of a magnetic material having a high magnetic permeability and a small coercive force, and is also a property of most magnetic materials except general non-magnetic materials and permanent magnets. The intermediate thin plate member is a soft magnetic material having a thickness less than the maximum thickness at which the magnetic short circuit magnetic flux generated inside the thin magnetic material of the thin plate is saturated by the magnetic flux generated from the magnetic field generating member during braking. A conductive material is a laminate of materials having a thickness sufficient to ensure at least the required thermal conductivity.
[0009]
A magnet case according to a second aspect of the present invention comprises a braking disk made of a ferromagnetic material and connected to a rotating shaft of an engine; and a plurality of magnetic fields acting on the braking surface of the braking member during braking. Used in an eddy current type speed reducer comprising a permanent magnet and a drive mechanism for moving the permanent magnet toward and away from the braking surface of the braking member, and applied to a case that accommodates the permanent magnet in a movable state Is done. At least the entire surface of the end facing the braking surface of the braking disk is formed of a member having a structure in which a first member having high thermal conductivity and a soft magnetic second member are bonded together .
[0010]
As described above, according to the present invention, since the material having high thermal conductivity is used for the intermediate thin plate member disposed between the magnetic field generating member such as a permanent magnet and the braking member, the heat generated from the braking member Is easily radiated to the outside through the intermediate thin plate member. As a result, the distance between the magnet and the braking member can be shortened, which contributes to an improvement in braking efficiency.
[0011]
In addition, since the material of the intermediate thin plate member is a soft magnetic material, the amount of magnetic flux reaching the braking member from the magnet through the intermediate thin plate member during non-braking can be reduced. As a result, the distance between the magnet and the braking member where magnetic leakage loss does not become a problem can be shortened compared to the case where a non-magnetic intermediate thin plate member is used. As a result, when a magnetic field generating member such as a permanent magnet is used, the moving stroke is shortened, and the apparatus can be miniaturized. During braking, the magnet is close to the intermediate thin plate member, and the magnetic flux density of the intermediate thin plate member becomes extremely larger than that during non-braking, so a soft magnetic intermediate thin plate member with a low saturation magnetic flux density may cause a magnetic short circuit. There is almost no decrease in braking efficiency as compared with the non-magnetic intermediate thin plate member.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described by taking as an example an eddy current type speed reducer in which a permanent magnet is brought close to and away from a disc-shaped braking member. However, the technical idea of the present invention is not limited to the shape of the braking member and the method of the magnetic generation unit, but to various types of eddy current type reduction gears that require a temperature increase of the magnetic generation unit and downsizing of the device. Applicable. In other words, the present invention can be applied to an eddy current reduction device using a drum-shaped braking member or an electromagnet or a combination of an electromagnet and a permanent magnet as a magnetism generator.
[0013]
1 and 2 are cross-sectional views showing the structure of the main part of a retarder according to a first reference example , in which FIG. 1 shows a non-braking state and FIG. 2 shows a braking state. The eddy current type speed reducer (retarder) according to the present embodiment includes a braking disk 2 made of a ferromagnetic material fixed to the rotating shaft 1 of the engine, and a braking unit (3- 7).
[0014]
The rotating shaft 1 is connected to a propeller shaft of a large vehicle (truck), for example. The brake disc 2 is formed in a disc shape and is arranged in such a manner that the rotation shaft 1 passes through the center. The braking unit includes a plurality of permanent magnets 6 that generate a braking magnetic field; a ring-shaped or arc-shaped holding member 4 that holds the permanent magnet 6; and a case 3 that houses the permanent magnet 6 and the holding member 4. A drive mechanism (air cylinder) 5 connected to the holding member 4 and moving the permanent magnet 6 close to and away from the brake disk 2; a cover (intermediate) disposed at the end of the case 3 on the brake disk 2 side; Thin plate member) 7.
[0015]
The brake disk 2 is formed of a ferromagnetic material, and the left side of the figure functions as a brake surface. A plurality of permanent magnets 6 are arranged on the surface of the holding member 4 at a predetermined interval in the circumferential direction. The cover 7 is formed of a soft magnetic material having a high thermal conductivity. Here, the thermal conductivity of the cover 7 is suitably at least 10 W / (m · k) or more, and more preferably 30 W / (m · k) or more. Further, the magnetism of the cover 7 is preferably 10 or more and 130 or less in terms of relative permeability (μs) with respect to vacuum defined by differential permeability at a magnetic field strength of 10000 A / m. If this value is smaller than 10, it becomes a paramagnetic or non-magnetic region, and if it is larger than 130, the magnetic flux around the magnetic short circuit formed in the cover 7 increases, leading to a reduction in braking force.
[0016]
The cover 7 can be formed integrally with the case (guide cylinder) 3 by pressing or casting. When the cover 7 is a separate member from the case 3, the cover 7 can be fixed to the case 3 by a method such as screwing, caulking, press fitting, adhesion, or welding. Moreover, the cross-sectional shape of the cover 7 does not need to be uniform, and a portion that does not face the magnet may be formed thick, or a rib may be partially provided to be reinforced.
[0017]
Further, as the cover 7 is thicker, the amount of magnetic leakage during non-braking is reduced and the temperature rise of the magnet 6 is also reduced, but the distance between the magnet 6 and the disk is increased, so that the braking efficiency is lowered. Accordingly, the thickness of the cover 7 is determined to be an optimum value from the magnetic leakage suppression effect, the magnet temperature increase suppression effect, and the braking efficiency. The optimum value of the thickness depends on not only the magnetic characteristics and thermal conductivity of the cover 7 but also the temperature characteristics of the magnet, and is therefore determined in consideration of these.
[0018]
The case 3 is desirably formed of a material such as aluminum, aluminum alloy, carbon steel, cast iron, stainless steel, or the like.
[0019]
In the eddy current type speed reducer of this reference example , as shown in FIG. 1, the permanent magnet 6 moves (withdraws) in a direction away from the braking disk 2 during non-braking. In this reference example , since the cover 7 is made of a soft magnetic material, the amount of magnetic flux reaching the brake disk 2 from the magnet 6 through the cover 7 during non-braking can be reduced. As a result, the distance between the magnet and the braking member where magnetic leakage loss does not become a problem can be shortened as compared with the case of using a nonmagnetic cover. As a result, the moving stroke of the permanent magnet 6 is shortened, and the apparatus can be miniaturized.
[0020]
During braking, since the cover 7 is thin and the saturation magnetic flux density is small, the magnet is close to the cover 7, the magnetic flux increases, and even if a magnetic short circuit occurs inside the cover 7, the magnetic flux that rotates around the magnetic short circuit is not generated. Since there are very few, there is almost no fall of braking efficiency compared with the cover of a nonmagnetic material.
[0021]
On the other hand, at the time of braking, as shown in FIG. 2, the permanent magnet 6 approaches the braking disk 2 and acts on the magnetic flux. By the way, the heat generated in the braking disk 2 is transmitted to the permanent magnet 6 side during braking, but in this reference example , the cover 7 is formed of a material having high thermal conductivity, so that the braking is performed as shown in FIG. Heat generated in the disk 2 is easily radiated to the outside through the cover 7. For this reason, in order to reduce the temperature rise of the permanent magnet 6, it is possible to avoid a situation where the distance between the magnet 6 and the braking disk 2 during braking is increased more than necessary, and as a result, it is possible to improve braking efficiency. It becomes.
[0022]
FIG. 4 is a sectional view showing the structure of the main part of the retarder according to the first embodiment of the present invention, and shows a braking state. In the present embodiment, the same or corresponding components as those in the reference example described above are denoted by the same reference numerals, and redundant description is omitted.
[0023]
In this embodiment, the cover 7 has a configuration (clad structure) in which a first member 7a made of a material having high thermal conductivity and a second member 7b made of a soft magnetic material are bonded together. The second member 7b is disposed on the braking disk 2 side, and the first member 7a is disposed on the permanent magnet 6 side. Here, the same effect can be expected even if the positions of the first member 7a and the second member 7b are reversed and the first member 7a is disposed on the braking disk 2 side and the second member 7b is disposed on the permanent magnet 6 side.
[0024]
In consideration of deformation of the cover 7 due to thermal expansion, a member (7a) having a high thermal conductivity is sandwiched between soft magnetic members (7b), or conversely, a soft magnetic member (7b) has a high thermal conductivity. A structure sandwiched between the members (7a) can be adopted. With such a sandwich structure, even when the cover 7 is thermally expanded, it is possible to suppress deformation such as a biased deflection in one direction.
[0025]
Examples of the material having high thermal conductivity used for the first member 7a include aluminum, aluminum alloy, copper alloys such as copper and brass, magnesium, and magnesium alloys having higher thermal conductivity than the soft magnetic material. In addition, other materials can be added with these materials as main components. The most desirable value for thermal conductivity is about 100 W / (m · k) or more.
[0026]
On the other hand, examples of the soft magnetic material used for the second member 7b include austenitic stainless steel, ferritic stainless steel, and duplex stainless steel. The relative permeability (μs) to vacuum defined by the differential permeability at the magnetic field strength of 10,000 A / m of the second member 7b is preferably 10 ≦ μs ≦ 130. In general, when austenitic stainless steel is not subjected to cold working, the magnetic properties are poor (low magnetic permeability), so it may be classified as a non-magnetic material. The martensite phase is induced, the magnetic permeability is increased, and the soft magnetic material referred to in the present invention is obtained.
[0027]
In short, the soft magnetic material in the present invention is most preferably an austenitic stainless steel or a ferritic stainless steel and a relative permeability (μs) of 10 ≦ μs ≦ 130. In ferritic stainless steel, it is possible to obtain the desired relative magnetic permeability as described above by adjusting the content of chromium (Cr).
[0028]
Also in this embodiment, the same effect as that of the first reference example can be obtained.
[0029]
FIG. 5 is a cross-sectional view showing the structure of the main part of the retarder according to the second embodiment of the present invention, showing a braking state. In the present embodiment, the same or corresponding components as those in the reference example and the embodiment described above are denoted by the same reference numerals, and redundant description is omitted.
[0030]
This embodiment is an application of the first embodiment shown in FIG. 4, and the cover 7 is not formed by a clad structure but is constituted by two completely different independent members. Then, after fixing the second member 7b on the permanent magnet 6 side to the case 3, the first member on the braking disk 2 side is fixed so as to cover the second member 7b. By using the first member 7a and the second member 7b having different characteristics as completely different members, various combinations can be selected according to the use conditions and conditions of the apparatus.
[0031]
In consideration of deformation of the cover 7 due to thermal expansion, a member (7a) having a high thermal conductivity is sandwiched between soft magnetic members (7b), or conversely, a soft magnetic member (7b) has a high thermal conductivity. A structure sandwiched between the members (7a) can be adopted. With such a sandwich structure, even when the cover 7 is thermally expanded, it is possible to suppress deformation such as a biased deflection in one direction.
[0032]
FIG. 6 is a cross-sectional view showing the structure of the main part of the retarder according to the second reference example , showing a braking state. FIG. 7 shows a part of a cross section in the AA direction in FIG. In this reference example , the same or corresponding components as those in the above-described embodiments are denoted by the same reference numerals, and redundant description is omitted.
[0033]
In the present reference example , the soft magnetic second member 7 b is partially arranged so as not to face the permanent magnet 6, and only the non-magnetic (high thermal conductivity) first member faces the permanent magnet 6. . According to the present embodiment, the distance between the magnet 6 and the brake disk 2 can be shortened, and the braking efficiency is further increased. Note that magnetic leakage during non-braking can be dealt with by increasing the thickness of the soft magnetic second member 7b.
[0034]
As mentioned above, although the Example (embodiment, embodiment) of this invention was described, this invention is not limited to these Examples at all, It changes in the category of the technical idea shown by the claim. It is possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a structure of a main part of a retarder according to a first reference example , and shows a non-braking state.
FIG. 2 is a cross-sectional view showing a structure of a main part of a retarder according to a first reference example , showing a braking state.
FIG. 3 is an explanatory view (cross-sectional view) showing a heat dissipation state during braking of the retarder according to the first reference example .
FIG. 4 is a cross-sectional view showing the structure of the main part of the retarder according to the first embodiment of the present invention, showing a braking state.
FIG. 5 is a cross-sectional view showing the structure of the main part of a retarder according to a second embodiment of the present invention, showing a braking state.
FIG. 6 is a cross-sectional view showing a structure of a main part of a retarder according to a second reference example , showing a braking state.
7 shows a part of a cross section in the AA direction in FIG.

Claims

機関の回転軸に連結された制動部材と；
制動時に前記制動部材の制動面に対して磁界を作用させる磁界発生部と；
前記磁界発生部を前記制動部材の制動面に対して制動と非制動とをスイッチさせる機構と；
前記磁界発生部材と前記制動面との間に配置され、前記制動面全面に対向する中間薄板部材とを備え、
前記中間薄板部材は、高熱伝導率を有する第１の部材と軟磁性の第２の部材とを、各部材が磁極面と平行になるように貼り合わせた構造であることを特徴とする渦電流式減速装置。A braking member connected to the rotating shaft of the engine;
A magnetic field generator for applying a magnetic field to the braking surface of the braking member during braking;
A mechanism for switching between braking and non-braking of the magnetic field generator with respect to the braking surface of the braking member;
An intermediate thin plate member disposed between the magnetic field generating member and the braking surface and facing the entire braking surface ;
The intermediate thin plate member has a structure in which a first member having high thermal conductivity and a soft magnetic second member are bonded so that each member is parallel to the magnetic pole surface. Type speed reducer.

前記第１の部材が前記制動部材の制動面に対向し、前記第２の部材が前記磁界発生部側に配置されることを特徴とする請求項１に記載の渦電流式減速装置。2. The eddy current reduction device according to claim 1 , wherein the first member faces a braking surface of the braking member, and the second member is disposed on the magnetic field generation unit side.

前記第２の部材が前記制動部材の制動面に対向し、前記第１の部材が前記磁界発生部側に配置されることを特徴とする請求項１に記載の渦電流式減速装置。2. The eddy current reduction device according to claim 1 , wherein the second member faces a braking surface of the braking member, and the first member is disposed on the magnetic field generation unit side.

前記第１の部材を前記第２の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項１に記載の渦電流式減速装置。 2. The eddy current reduction device according to claim 1, wherein the first member has a structure in which both surfaces of the second member are bonded to each other.

前記第２の部材を前記第１の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項１に記載の渦電流式減速装置。2. The eddy current reduction device according to claim 1 , wherein the second member has a structure in which both surfaces of the first member are bonded to each other.

前記第１の部材は、アルミニウム、アルミニウム合金、銅、黄銅等の銅合金、マグネシウム、マグネシウム合金から選択される１つ又は２つ以上の混合材を主成分とすることを特徴とする請求項１，２，３，４又は５に記載の渦電流式減速装置。The first member is of aluminum, according to claim 1, an aluminum alloy, wherein the copper, copper alloys such as brass, magnesium, that a main component one or two or more mixed materials are selected from magnesium alloy , 2, 3, 4 or 5. Eddy current type speed reducer.

前記第２の部材は、オーステナイト系ステンレス鋼、フェライト系ステンレス鋼又は二相ステンレス鋼を主成分とすることを特徴とする請求項１，２，３，４，５又は６に記載の渦電流式減速装置。The eddy current type according to claim 1, 2, 3, 4, 5 or 6 , wherein the second member is mainly composed of austenitic stainless steel, ferritic stainless steel or duplex stainless steel. Reducer.

前記制動部材は、前記機関の回転軸と一体に回転する制動ディスクであり、
前記磁界発生部は、複数の永久磁石と、当該永久磁石を保持する保持部材とを有し、
前記永久磁石及び保持部材を移動可能な状態で収容するケースを更に備え、
前記中間薄板部材は、前記制動ディスクの制動面に対向する前記ケースの端面全面に配置されるカバーであることを特徴とする請求項１に記載の渦電流式減速装置。The braking member is a braking disk that rotates integrally with a rotating shaft of the engine,
The magnetic field generator has a plurality of permanent magnets and a holding member that holds the permanent magnets,
A case for accommodating the permanent magnet and the holding member in a movable state;
2. The eddy current reduction device according to claim 1, wherein the intermediate thin plate member is a cover disposed over the entire end surface of the case facing the braking surface of the braking disk.

前記第１の部材が前記制動部材の制動面に対向し、前記第２の部材が前記永久磁石側に配置されることを特徴とする請求項８に記載の渦電流式減速装置。The eddy current reduction device according to claim 8 , wherein the first member faces a braking surface of the braking member, and the second member is disposed on the permanent magnet side.

前記第２の部材が前記制動部材の制動面に対向し、前記第１の部材が前記永久磁石側に配置されることを特徴とする請求項８に記載の渦電流式減速装置。The eddy current reduction device according to claim 8 , wherein the second member is opposed to a braking surface of the braking member, and the first member is disposed on the permanent magnet side.

前記第１の部材を前記第２の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項８に記載の渦電流式減速装置。The eddy current type speed reducer according to claim 8 , wherein the first member has a structure in which both surfaces of the second member are bonded to each other.

前記第２の部材を前記第１の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項８に記載の渦電流式減速装置。The eddy current type speed reducer according to claim 8 , wherein the second member has a structure in which both surfaces of the first member are bonded to each other.

前記第１の部材は、アルミニウム、アルミニウム合金、銅、黄銅等の銅合金、マグネシウム、マグネシウム合金から選択される１つ又は２つ以上の混合材を主成分とすることを特徴とする請求項８，９，１０，１１又は１２に記載の渦電流式減速装置。The first member is aluminum, claim wherein an aluminum alloy, copper, copper alloys such as brass, magnesium, that a main component one or two or more mixed materials are selected from magnesium alloy 8 , 9, 10, 11 or 12. Eddy current type speed reducer.

前記第２の部材は、オーステナイト系ステンレス鋼、フェライト系ステンレス鋼又は二相ステンレス鋼を主成分とすることを特徴とする８，９，１０，１１，１２又は１３に記載の渦電流式減速装置。The eddy current type speed reducer according to 8, 9, 10, 11, 12 , or 13 , wherein the second member is mainly composed of austenitic stainless steel, ferritic stainless steel or duplex stainless steel. .

機関の回転軸に連結された制動ディスクと；制動時に前記制動部材の制動面に対して磁界を作用させる複数の永久磁石と；前記永久磁石を前記制動部材の制動面に対して接近、離間させる駆動機構とを備えた渦電流式減速装置に使用され、前記永久磁石を移動可能な状態で収容するケースにおいて、
少なくとも前記制動ディスクの制動面に対向する端部全面が、高熱伝導率を有する第１の部材と軟磁性の第２の部材とを貼り合わせた構造の部材で構成されることを特徴とする渦電流式減速装置用の磁石ケース。A braking disk coupled to the rotating shaft of the engine; a plurality of permanent magnets that act on the braking surface of the braking member during braking; and the permanent magnet is moved toward and away from the braking surface of the braking member Used in an eddy current type speed reducer equipped with a drive mechanism, and in the case of accommodating the permanent magnet in a movable state,
A vortex characterized in that at least the entire surface of the end facing the braking surface of the braking disk is composed of a member having a structure in which a first member having high thermal conductivity and a soft magnetic second member are bonded together. Magnet case for current type speed reducer.

前記第１の部材が前記制動部材の制動面に対向し、前記第２の部材が前記永久磁石側に配置されることを特徴とする請求項１５に記載の磁石ケース。The magnet case according to claim 15 , wherein the first member faces a braking surface of the braking member, and the second member is disposed on the permanent magnet side.

前記第２の部材が前記制動部材の制動面に対向し、前記第１の部材が前記永久磁石側に配置されることを特徴とする請求項１５に記載の磁石ケース。The magnet case according to claim 15 , wherein the second member is opposed to a braking surface of the braking member, and the first member is disposed on the permanent magnet side.

前記第１の部材を前記第２の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項１５に記載の磁石ケース。The magnet case according to claim 15 , wherein the magnet case has a structure in which the first member is bonded to both front and back surfaces of the second member.

前記第２の部材を前記第１の部材の表裏両面に貼り合わせた構造であることを特徴とする請求項１５に記載の磁石ケース。The magnet case according to claim 15 , wherein the magnet case has a structure in which the second member is bonded to both front and back surfaces of the first member.

前記第１の部材は、アルミニウム、アルミニウム合金、銅、黄銅等の銅合金、マグネシウム、マグネシウム合金から選択される１つ又は２つ以上の混合材を主成分とすることを特徴とする請求項１５，１６，１７，１８又は１９に記載の磁石ケース。The first member is of aluminum, aluminum alloy, according to claim 15 for copper, copper alloys such as brass, magnesium, characterized in that a main component one or two or more mixed materials are selected from magnesium alloy , 16, 17, 18, or 19 .

前記第２の部材は、オーステナイト系ステンレス鋼、フェライト系ステンレス鋼又は二相ステンレス鋼を主成分とすることを特徴とする請求項１５，１６，１７，１８，１９又は２０に記載の磁石ケース。 21. The magnet case according to claim 15, 16, 17, 18 , 19 or 20 , wherein the second member is mainly composed of austenitic stainless steel, ferritic stainless steel or duplex stainless steel.