JP3968454B2 - Magnet holder - Google Patents

Description

【００５８】
さらに、このように強力な保持力を有しているにもかかわらず、用紙を用いずに直接ホワイトボードに留めた場合でも、磁気吸着面が下に凸の曲面で形成されているため揺動し易く、底面に隙間のある端部の上部を人差指で押すと同時に、他端部を親指で持ち上げることにより、マグネットホルダーを立ち上げ、両指で掴み、容易に取り外すことができた。また、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
（実施例２） （図２参照）
直径２５ｍｍ、厚さ４．０ｍｍのアクリル樹脂製ディスクを素材として、両側の表面を互いに９０°交差し中心部の幅１０ｍｍを残し、曲率半径が３０ｍｍとなるように湾曲面に研削加工した。さらに、中心部に直径１０ｍｍのキリ穴を開けて本体２２ａを得た。加工後の本体周囲の厚さは最も薄い部分で２．１ｍｍ、厚い部分で２．２ｍｍであり、ほぼ同じ適度の厚さを有していた。揺動角θは約２５度であった。
次に、本体２２ａの中心部に開けたキリ穴に、実施例１と同じ着磁したＮｄ系焼結磁石１０を挿入し、エポキシ系接着剤で固定し、模式的に図２に示すマグネットホルダー２２を得た。
【００５９】
マグネットホルダー２２について、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように、いずれの試験結果においても十分な保持力を有することが分かった。特に、磁極面と被掲示体との距離が実施例１の場合より近づくため、マグネットホルダー２１の磁気吸着力を若干上回る保持力を有することが分かった。
さらに、用紙を用いず、直接ホワイトボードに留めた場合でも、磁気吸着面が中心部の一部を除いて下に凸の曲面で形成されているため、揺動し易く、脱着が極めて容易であった。また、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
【００６０】
（実施例３） （図４参照）
１辺３０ｍｍの正四辺形、厚さ６．０ｍｍのアクリル樹脂製の板材を素材として使用した。図４に示すように素材板の４隅の角を切り落とし、対辺距離３０ｍｍの正８角形に加工、さらに、中央部の幅１０ｍｍの部分を平面のまま残し、その平面から２０°となるように両側を研削加工した。同様にして反対側の面も互いに外側に凸の曲面が９０°交差するように研削加工した。さらに、中心部に直径８ｍｍのキリ穴を開けて本体２４ａを得た。加工後の周囲の厚さは最も薄い部分で２．２ｍｍ、厚い部分で２．４ｍｍであり、ほぼ同じ適度の厚さを有していた。
次に、本体２４ａの中心部に開けたキリ穴に厚さ方向に着磁したφ８ｍｍ×ｔ６ｍｍのＮｄ系焼結磁石１１を挿入し、エポキシ系接着剤で固定し、図４に模式的に示すように、マグネットホルダー２４を得た。
【００６１】
マグネットホルダー２４について、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように、磁石形状は異なるものの、ほとんど同じ体積の磁石１０を用いたマグネットホルダー２２とほとんど同じ十分な保持力を有していた。さらに、用紙を用いず、直接ホワイトボードに留めた場合でも、磁気吸着面が下に凸の曲面で形成されているため、揺動し易く、脱着が極めて容易であった。また、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
【００６２】
（比較例１）
実施例１および実施例２の素材として用いたのと同じＮｄ系焼結磁石１０を用いて、そのままの状態で試験方法１および試験方法２により保持力を調べた。その結果は表１に示すように、保持力は実施例２と同じであった。ただし、ホワイトボードに取り付けた状態では素手では取り外すことができなかった。取り外すためには、ペンチ等の道具を用いて取り外す必要があり、極めて使い勝手が悪かった。
【００６３】
（比較例２）
実施例１および実施例２の素材として用いたのと同じＮｄ系焼結磁石１０を用いて、片面のみ平面のままとしたことを除き、その他は実施例２と同様にしてマグネットホルダーを作成した。曲面に加工した側を磁気吸着面とした場合は、実施例２と同じように揺動するため、脱着は容易であった。しかしながら、平面側を吸着面とした場合は、磁石をそのままの状態で用いた比較例１よりは楽なものの、素手では無理して何とか外せる状況であり、極めて使いにくかった。
【００６４】
（比較例３）
強力磁石１６をプラスチック製ディスク５０ａの片側の偏心した位置に開けた空洞部に接着剤で固定した図１１に示す市販品マグネットホルダー５０（コクヨ製、商品名“カラーマグネット”）を用いて、試験方法１および２にて試験を行った。ディスク５０ａの外径は３０ｍｍ、厚さは６．２ｍｍであり、磁石１６を取り出し寸法を測定した結果、直径１０ｍｍ×厚さ２ｍｍであった。また、成分分析等により磁石１６はＮｄ系焼結磁石であることが判明した。
保持力の試験結果は表１に示すように、当該マグネットホルダー５０は試験方法１では本発明のマグネットホルダー２１〜２３に比べてその保持力は小さいものの十分実用的な保持力を有していた。しかし、試験方法２ではほとんど保持力を示さず、折角強力なＮｄ系焼結磁石を用いているにもかかわらず、利用方法が限定されることが分かった。
また、使用を繰り返す内に、メッキが剥離したりして磁石が本体から脱落し、使えなくなる頻度が高かった。
【００６５】
（実施例４） （図５参照）
実施例２と同様にして、直径３０ｍｍ、厚さ５．５ｍｍのアクリル樹脂製のディスク素材を用いて、両側の表面を互いに９０°交差し中心部の幅１０ｍｍを残し、曲率半径が中心部近傍の５０ｍｍから周辺部の３０ｍｍに連続的に変化する湾曲面となるように研削加工した。さらに、中心部にまず直径８ｍｍの貫通穴を開け、次に両側からエンドミルを用いて直径１０ｍｍの穴を深さ２ｍｍまで開けて本体２５ａを得た。加工後の本体周囲の厚さは最も薄い部分で２．８ｍｍ、厚い部分で２．９ｍｍであり、ほぼ同じ適度の厚さを有していた。揺動角θは約２５度であった。
次に、本体２５ａの中心部に開けた穴の深さ方向中央部に直径８ｍｍ厚さ１．５ｍｍの電磁軟鉄製のヨーク３０を挿入し、さらに直径１０ｍｍ厚さ２ｍｍでかつ着磁方向が厚さ方向のＮｄ系焼結磁石１２を本体２５ａの両側から各１個挿入し、模式的に図５に示すマグネットホルダー２５を得た。
【００６６】
マグネットホルダー２５について、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように、いずれの試験結果においても十分な保持力を有することが分かった。磁石体積はマグネットホルダー２１〜２３と同じであるが、若干上回る保持力を有することが分かった。
さらに、用紙を用いず、直接ホワイトボードに留めた場合でも、磁気吸着面が中心部の一部を除いて下に凸の曲面で形成されているため、揺動し易く、脱着が極めて容易であった。また、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
【００６７】
（実施例５） （図６参照）
素材として、横幅６．０ｍｍ、長さ：１２ｍｍ、厚さ：３．０ｍｍの直方体形状のＮｄ系焼結磁石１３を２枚準備した。ただし磁場成型時の配向方向は厚さ方向である。
次に模式的に図６に示すような形状の本体部２６ａをアクリル樹脂を使用して射出成型法で作製した。寸法は直径：３０ｍｍ、最大厚さ：６ｍｍとし、それぞれの面を中央部の幅８ｍｍを除いて、中央部近傍の曲率半径が４０ｍｍ、周辺部の曲率半径が３０ｍｍとなるように成型した。なお、成型時に、前記磁石が収まるキャビティを両側に造り込んだ。
着磁した前記磁石１３ａ、１３ｂを、両側からキャビティに挿入し、マグネットホルダー２６を得た。本体の円周部の厚さは最も薄い部分で２．８ｍｍ、厚い部分で３．０ｍｍであり、ほぼ同じ適度の厚さを有していた。揺動角θは約２７度であった。
【００６８】
マグネットホルダー２６について、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように十分な保持力を有することが分かった。また、平面部の幅が狭く、湾曲面が広いため揺動し易く、マグネットホルダーの脱着が容易であるだけでなく、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
【００６９】
（実施例６） （図７参照）
直径２５ｍｍ、厚さ５．０ｍｍのアクリル樹脂製のディスクを素材として、両側の表面を互いに９０度交差し中心部近傍の曲率半径が５０ｍｍ、周辺部の曲率半径が３０ｍｍとなるように湾曲面に研削加工した。次に、中心部に両側から直径１１ｍｍ、深さ０．５ｍｍのキリ穴をエンドミルを用いて開け、さらに直径１０ｍｍのキリ穴を貫通させ、本体２７ａを得た。加工後の本体周囲の厚さは最も薄い部分で２．５ｍｍ、厚い部分で２．９ｍｍであり、ほぼ同じ適度の厚さを有していた。揺動角θは約２２度であった。
次に、本体中心部の直径１０ｍｍのキリ穴に実施例１と同じＮｄ系焼結磁石１０を挿入し、さらに両面から直径１１ｍｍ、厚さ０．５ｍｍのＳＵＳ４４４製の円盤形状のヨーク３１ａ、３１ｂで蓋をし、これらをエポキシ系接着剤で固定した。さらに、本体の表面形状に合わせて、ヨークを研削加工し模式的に図７に示すマグネットホルダー２７を得た。
【００７０】
マグネットホルダー２７を着磁後、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように、同じ磁石を用いたマグネットホルダー２２、２３には若干劣るものの、十分な保持力を有していた。さらに、本形式のマグネットホルダーは磁石１０がヨーク３１で覆われているため、金属面で滑らせたり過酷な使い方をしても、磁石には全く影響しなかった。また、磁石は磁力でも本体に強固に固定されているため脱落せず耐久性が優れていることが分かった。
なお、用紙を用いず、直接ホワイトボードに留めた場合でも、磁気吸着面がスムーズな下に凸の曲面で形成されているため、揺動し易く、脱着が極めて容易であった。また、被掲示体にマグネットホルダーを吸着させた状態で、上端を押すことにより、掲示物の抜き差しが極めて容易に行えることが分かった。
【００７１】
（実施例７） （図８参照）
厚さ１．２ｍｍのフェライト系ステンレス鋼ＳＵＳ４４４の鋼板を素材として、幅８ｍｍ×１５ｍｍの長方形に切り出し、１５ｍｍ長さ方向の片側の端面を曲率半径が３５ｍｍとなるように研削加工しヨーク３２とした。配向方向が厚さ方向で、寸法が厚さ３ｍｍ×幅５ｍｍ×長さ１０ｍｍの直方体形状のＮｄ系磁石１３を着磁し、両側に前記ヨーク３２をセットし、予め準備したシリコンゴム製の鋳型を用いて、市販されているポリエステル系樹脂（（株）土筆レジン手芸研究所製“ポリテル”）を流し込み図８に模式的に示す形状のマグネットホルダー２８を作製した。本体２８ａの直径は３０ｍｍである。鋳込み成型後さらに、図８（ｂ）正面図の本体２８ａの下側曲線は中央部の曲率半径が３５ｍｍ、周辺部は約２５ｍｍのスムーズな曲線となるように、研削加工により仕上げた。一方、図８（ｃ）側面図の本体２８ａの上側曲線は中央部の約５ｍｍを平面とし、その両側が曲率半径約３０ｍｍの曲面となるように、成型後研削加工により仕上げを行った。研削加工後の本体ａの中央部の厚さは７．５ｍｍ、周辺部の厚さは最も薄い部分で３．４ｍｍ、厚い部分で３．６ｍｍであり、ほぼ同じ十分な厚さを有していた。揺動角θは約２９度であった。
【００７２】
マグネットホルダー２８について、試験方法１および試験方法２により保持力を調べた。その結果、表１に示すように、いずれの試験結果においても十分な保持力を有することが分かった。特に、正面図に示す下側が吸着面になるようにホワイトボードに留めた場合は、極めて小さな力で揺動し、掲示物の脱着がし易く極めて便利であることが分かった。その反対側を吸着面とした場合は、表１の下段に（）内に示すように、２０枚と磁極となるヨークの端面の全面が掲示物に密着するため、試験方法１での磁気吸着力がより強くなることが知られた。このような特徴から使用目的によって、両面を使い分けることができる。
【００７３】
【発明の効果】
以上説明したように、本発明のマグネットホルダーは極めて大きな磁気吸着力を有するにもかかわらず被掲示体からの取り外しが容易である。また、マグネットホルダーの表側も磁気吸着力を有する。そのため、バインダークリップのような汎用留め具で留めた用紙も、これらの磁性部をマグネットホルダーの上面に吸着させることにより十分な保持力で固定できる特長を有する。しかも、近づけるだけで、磁気吸引力が働き、極めて容易に固定できる。さらに用紙を引っ張ることにより、簡単に外すことができる。また、マグネットホルダーを揺動させることで、掲示物の脱着が可能となり、使い勝手は極めて良好となる。
【００７４】
さらに、Ｎｄ系磁石の生産工程で、あるいは使用済みの家電やエレクトロニクス関連機器から大量に発生するＮｄ系磁石スクラップを有効に活用し、リュース、リサイクルを可能にするため、地球環境への負荷低減にも役立ち、かつ貴重かつ高価なＮｄ系磁石を使っているにもかかわらず、安価にすることができる。
【図面の簡単な説明】
【図１】本発明のマグネットホルダーの実施例１に係わるマグネットホルダーを第３角法で示す図である。
【図２】本発明の実施例２に係わるマグネットホルダーを第３角法で示す図である。
【図３】本発明の別の実施態様を第３角法で示す図である。
【図４】本発明の実施例３に係わるマグネットホルダーを第３角法で示す図である。
【図５】本発明の実施例４に係わるマグネットホルダーを第３角法で示す図である。
【図６】本発明の実施例５に係わるマグネットホルダーを第３角法で示す図である。
【図７】本発明の実施例６に係わるマグネットホルダーを第３角法で示す図である。
【図８】本発明の実施例７に係わるマグネットホルダーを第３角法で示す図である。
【図９】ＶＣＭから本発明のマグネットホルダーに用いる磁石を切り出す方法を示す模式図である。
【図１０】湾曲面を９０度交差させずに向き合わせたマグネットホルダーの例を示す図である。
【図１１】比較例３に係わるマグネットホルダーを第３角法で示す図である。
【符号の説明】
１０、１１、１２、１３、１４、１５、１６：希土類磁石
４０：ＶＣＭ磁石
２１、２２、２３、２４、２５、２６、２７、２８、２９、５０：マグネットホルダー
３０、３１、３２：ヨーク[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnet holder used to fix a piece of paper using a strong rare earth magnet to the surface of a household appliance such as a steel refrigerator or office equipment such as a whiteboard or cabinet by using magnetic attraction. Involved. The magnet holder itself is easy to attach and detach even though the holding power is increased by using a strong rare earth magnet, and it is possible to attach and detach postings such as notes without removing the magnet holder. However, by providing a strong magnetic attractive force, papers fixed with a binder clip or the like can be easily held by adsorbing the binder clip on the upper surface thereof. In addition, it is easy to use so that it can be used without distinction between the top and bottom and the top and bottom.
[0002]
[Prior art]
Steel office equipment such as whiteboards and steel cabinets, or the sides and doors of household appliances such as refrigerators, steel equipment (hereinafter referred to as “posts”), paper such as memos and posters (hereinafter abbreviated as “postings”) For the purpose of fixing), a magnet holder using a magnetic attraction force is widely used. Many of the magnets used in such a magnet holder are ferrite magnets. Ferrite magnets are inexpensive, but their magnetic force is weak, and the size and number of postings that can be fixed and held on the posting object are limited. On the other hand, if you want to increase the holding force, a large magnet is required and covers the postings. There was a problem that the area would increase.
[0003]
Recently, as a method for solving the above problems, a magnet holder in which the strongest Nd-based magnet among rare earth magnets is incorporated on the back side of a transparent plate-like or disc-like plastic has been devised (Japanese Patent Laid-Open No. 11-11072). ing.
[0004]
[Problems to be solved by the invention]
The magnet holder in which the Nd-based magnet is embedded in plastic is suitable for fixing a paper piece or the like from its upper surface, but is covered with plastic except for the magnetic adsorption surface. Despite the fact that the magnetic attractive force is extremely weak and uses an Nd-based magnet that is strong at the corner, for example, a sheet fastened with a general-purpose fixing part such as a binder clip or a gem clip is held using these iron clip portions. There was inconvenience that we could not.
[0005]
The magnet holder of the present invention has been devised in view of the above-mentioned problems. The purpose of the magnet holder is as follows: (1) it has a large magnetic attraction force and can be easily removed from the object to be displayed; (2) It is possible to attach and detach postings such as memos with a single touch, and (3) postings that are fastened with steel paper sheet fixtures such as binder clips and zem clips are also sufficient by bringing these parts close to the top surface of the magnet holder. The purpose is to provide a versatile magnet holder that can be magnetically attracted with high strength. Furthermore, (4) even if the magnet holder is turned upside down or turned upside down, the above functions are maintained and the usability is improved.
[0006]
In addition, Nd-based magnet scraps generated in large quantities from the production process of Nd-based magnets or from electronic devices such as used home appliances and personal computer peripherals are effectively used to establish recycling and reuse technologies that help reduce environmental impact. There is to do.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the magnet holder of the present invention has a main body made of a non-magnetic material such as plastic, and three-dimensionally, its upper and lower surfaces intersect each other by 90 degrees, and is formed of a curved surface that is convex on the front side, and The rare-earth magnet is embedded in the central portion of the main body so that its magnetic pole surface is directly or via a yoke made of a soft magnetic material so as to be in a position substantially the same as or slightly recessed from the main body surface.
Specifically, for example, a main body 21a (hereinafter abbreviated as a main body) of the magnet holder 21 is shown in FIG. It is made of a non-magnetic material such as plastic, and the shape thereof is as follows. (B) In the front view, (a) the lower side forms a downwardly convex curve 21b, and the upper surface outline 21c is a flat straight line. (B) In the side view, (b) a curved line 21d whose upper side is convex upward is formed, the lower outline is a straight line 21e in contact with the horizontal line, and (c) the rare earth magnet 10 has its magnetic pole at the center of the main body 21a. A magnet holder for fixing a piece of paper, characterized in that the surface is embedded so as to be the same as or slightly recessed from both surfaces of the main body. In addition, although (a) various shapes are selected as the shape of the plan view, FIG. 1 shows a circular case as a representative example.
[0008]
Alternatively, as shown in another example in FIG. 2, the vicinity of the central portion is constituted by a plane instead of the curved surface on one side or both sides of FIG. Alternatively, as shown in FIG. 3, instead of the curved surface on one side or both sides, two planes in which the surface on one side or both sides forms an angle of 10 degrees to 40 degrees with the central plane and the plane. It is characterized by comprising a total of three planes.
[0009]
As described above, since the magnetic attracting surface is formed as a curved surface convex outward, the magnetic attracting surface is easy to swing in a state of being attracted on the display object. For example, when the end of the upper surface with a gap on the bottom surface is pushed with the index finger At the same time, the magnet holder can be easily raised by lifting the other end with the thumb. In the upright state, it is easy to grasp with both fingers and the magnetic attraction force is almost lost, so it can be removed very easily.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
As described above, the magnet holder of the present invention is mainly characterized in that both surfaces are constituted by curved surfaces protruding outward. In a magnet holder in which only one surface is a curved surface and the remaining surface is a flat surface, if the flat surface side is attracted to the display object, there arises a problem that it becomes difficult to remove. In particular, since the rare earth magnet has a small holding force even if it is small, the entire magnet holder can be reduced in size and thickness. However, in such a magnet holder, a situation in which the front and back are reversed during daily use can sufficiently occur. By configuring both surfaces with curved surfaces, it becomes easy to remove either surface when it is adsorbed to the object to be displayed, so there is no problem even if such a situation occurs. Moreover, it can be used without distinguishing between the front and back sides, and usability can be improved.
[0011]
Furthermore, the magnet holder of the present invention is placed on the posting body so that the swinging direction is up and down, the upper part of the posting object such as a memo is attached to the upper part with the finger pressed upward. It can be fixed by releasing your finger after inserting from the bottom. It can be removed by lifting the lower side in the same way. In this way, desorption is extremely simple.
[0012]
Secondly, the magnet holder of the present invention is characterized by the fact that the convex curved surfaces on the outer sides of the front and back intersect each other by 90 degrees, and the reason for such contrivance will be described below.
If the curved surfaces face each other without intersecting by 90 degrees, as shown in FIG. 10 as an example when a curved surface is selected as a curved surface, a thinned portion is generated at the end, and in an extreme case, it becomes a knife edge and is difficult to handle. Become. In order to avoid such a problem without intersecting the curved surfaces of both surfaces by 90 degrees, it is necessary to increase the curvature radius or increase the thickness of the magnet holder. In the former method, the swing range is narrowed and it is difficult to remove. On the other hand, the latter method not only lowers the commercial value of the magnet holder, but also unnecessarily uses a thicker magnet, thereby reducing cost performance.
[0013]
Furthermore, in general, a rare earth magnet is advantageously a magnet having a small thickness in the magnetization direction with respect to its size because of its magnetic properties. In order to reduce the manufacturing cost of the magnet holder, it is effective to use scraps such as defective dimensions generated in the rare earth magnet manufacturing process and magnets collected from used equipment. And these magnets are also many thin magnets for a size for the said reason. If the magnet holder is made thicker, it becomes necessary to make the magnet thicker, the number of reusable magnets is limited, and it becomes difficult to manufacture an inexpensive magnet holder.
[0014]
All such problems can be solved by intersecting the curved surfaces on both sides of the magnet holder by 90 degrees. For example, when the main body is a magnet holder having a diameter of 25 mm and a thickness of 5.5 mm, if the main body has a curved surface with a curvature radius of 30 mm, the thickness of the end portion does not intersect the curved surface. When facing each other, it becomes almost 0.04 mm and becomes a knife edge, which makes it difficult to handle. On the other hand, when crossing 90 degrees, the thickness of the end portion is sufficiently thick as 2.77 to 2.84 mm, and almost the same thickness over the entire circumference. In this case, the swing range is 24.6 degrees on both sides, which is sufficiently large and easy to remove.
[0015]
Further, when the upper end portion of the magnet holder is pushed for removal, if the curved surfaces are crossed by 90 degrees, the upper surface becomes flat with respect to the swinging direction, and it is easy to push and remove. On the other hand, when the curved surfaces are formed by facing each other in the same direction without crossing 90 degrees, the portion to be pushed is inclined so as to fall on the posted object surface side, so that it is difficult to push and the usability is deteriorated.
[0016]
As described above, the above-described problems can be solved only by configuring the two curved surfaces so as to intersect each other by 90 degrees so that the convex surfaces are on the outside. And with such a device, even if the magnetic attraction is strong, it is easy to remove, and even if it is not thicker than necessary, the end has an appropriate thickness and is durable, excellent in performance, and low in cost. Manufacture is possible.
The case where the surface shape is a curved surface has been described above, but the same applies to a curved surface having a flat central portion of the curved surface or a curved surface composed of three planes.
[0017]
Next, the reason why a strong magnetic attractive force is given to the upper and lower surfaces, which is a feature of the magnet holder of the present invention, will be described.
In the magnet holder of the present invention, for example, the upper end portion of the paper is fastened with a binder clip, and the steel clip portion can be easily attached and detached. Fasteners such as binder clips are very widely used and have strong paper holding power. When the magnet is fastened, the magnetic force works, and it is attracted and held only by bringing it close, and when it is released, the object can be achieved simply by grasping and pulling the paper. Therefore, for example, when fixing the magnet holder of the present invention to the side of a steel desk and removing frequently used postings such as an in-house phone book, there is no problem even if it is slightly deviated from the target, and it is extremely convenient to use. It becomes. That is, it becomes convenient that the object can be achieved by groping in a posture while sitting on a chair.
[0018]
Next, the shape of the convex curve below the lower side in the front view and the shape of the convex curve above the upper side in the side view will be described in more detail.
A specific shape of these curves can be, for example, an arc. Alternatively, by setting the radius of curvature near the center point C shown in FIG. 1B to be larger than the radius of curvature of the peripheral portion, for example, a magnet having a flat magnetic pole surface, such as a disk shape, is placed inside the surface of the magnet holder. Even when the magnet is embedded so that the distance between the display object and the magnet can be reduced over a wider area, the magnetic attractive force can be increased. More desirably, the curve may be such that the radius of curvature of the portion continuously decreases as the distance from the center point C increases. As an example of such a shape, a curve including a portion having the largest curvature radius of an ellipse can be used. Or you can choose a parabola. When such a curved shape is selected, when it is actually used, when one side of the top surface of the magnet holder is pushed and swung for insertion / removal of the bulletin board or attachment / detachment of the magnet holder, the movement becomes smooth and user-friendly. It becomes good.
[0019]
The shape of the curved surface on the bottom surface is easy to remove and makes it easier to put your finger on the rocking surface, so that the gap created between the bottom edge of the lifted part and the display object is reasonably large. Decide on. As a result of prototyping various types of magnet holders and examining their ease of removal, as shown in FIG. 1 (b), the angle formed by the tangents to the curved surfaces at both ends with the plane, that is, swinging for removal It has been known that it is desirable to select an angle θ (hereinafter referred to as a rocking angle θ) in the range of 10 to 45 degrees. More preferably, it is selected from the range of 10 to 40 degrees. When the dimensions are actually determined, the thickness of the thinnest part in the surrounding area is determined so as not to be too thin. Specifically, the thickness is set to 1.0 mm or more, more preferably 1.5 mm or more.
[0020]
In another example of the magnet holder according to the present invention, as shown in FIGS. 2 (b) and 2 (c), the main body in the drawing drawn by the third trigonometric method in a state where the attracting surface is placed on the horizontal surface is located below. The shape is a straight line where the lower center part is in contact with the horizontal line, and the left and right sides are formed with downwardly convex curves, the upper contour line is a flat straight line, and in the side view, a part of the upper center part Is a straight line parallel to the horizontal line, and both left and right sides are formed as upwardly convex curves, and the lower outline is a straight line in contact with the horizontal line. Three-dimensionally, only the central portion of the curved surface convex to the outside of FIG. A combination in which only one side of both surfaces is such a curved surface can also be adopted.
[0021]
Alternatively, in another example of the magnet holder according to the present invention, in the drawing drawn by the third trigonometric method in a state where the attracting surface is placed on the horizontal surface as shown in FIGS. 3 (b) and 3 (c). In the front view, the shape of the main body is a straight line in which the lower center part is in contact with the horizontal line, and its left and right sides are formed with straight lines that form 10 to 40 degrees with the straight line, and the contour line on the upper surface is a flat straight line. In the figure, the upper central part is a straight line parallel to the horizontal line, the left and right sides are formed by straight lines forming 10 to 40 degrees with respect to the central straight line, and the lower contour line can be a straight line in contact with the horizontal line. .
[0022]
Three-dimensionally, a curved surface composed of a central plane portion and three planes of 10 to 40 degrees is rotated by 90 degrees, and the convex portions face each other. If the angle is 10 degrees or more, the swinging range is too small below that, and when one side of the magnet holder is pushed and the opposite side is lifted, the gap formed between the display object and the magnet holder is small and difficult to remove. Become. On the other hand, at 40 degrees or more, when one side of the upper surface is pressed, the component force for pushing the magnet holder in the direction parallel to the surface of the display object is increased, and the usability is deteriorated. In this case as well, it is possible to combine a curved surface composed of three planes on one side and a curved surface on the opposite side, or a curved surface having only the central portion of the curved surface as a plane.
[0023]
In the case where only the central portion of the curved surface is constituted by a plane, or in the case where the curved portion is constituted by the plane portion of the central portion and a plane which forms 10 to 40 degrees therewith, the plane portion of the central portion Is less than ½ of the width of the main body. If it is 1/2 or more, a large force is required to push and swing one side of the upper surface of the magnet holder, making it difficult to remove. Furthermore, the width of the plane portion is desirably set to 1 / 2.5 or less of the width of the main body. In addition, the width of the flat surface portion can be made equal to or slightly larger than the diameter or width of the magnet embedded in the center of the main body, as will be described later, so that it matches the surface level of the main body on the entire surface of the magnetic pole of the magnet. This makes it possible to maximize the magnetic attractive force and at the same time widen the swing range.
[0024]
Japanese Patent Application Laid-Open No. 11-11072 discloses a magnet holder provided with a chamfered portion along the back surface or outer peripheral edge of the main body. However, the chamfered portion is provided for the purpose of facilitating insertion of the paper, and its width is also narrow. In the present invention, the chamfered portion is wide, or the entire surface is formed of a curved surface or a curved surface including a part of a flat surface, thereby enabling smooth swinging and extremely easy removal of the magnet holder from the display object. It is not mentioned that a specific function occurs.
[0025]
Next, the plan view shape of the magnet holder body will be described.
As the shape of the main body of the present invention, a circular shape is selected as a representative shape in a plan view drawn with a magnetic adsorption surface on a horizontal plane. Alternatively, as shown in an example in FIG. 4, a mirror-symmetric octagon is selected as a more desirable shape in the horizontal direction. This is because, in the case of such a planar shape, the thickness of the peripheral portion of the main body is increased in combination with the selection of a structure in which convex curved surfaces intersect each other by 90 degrees as in the present invention. This is because it does not fluctuate, that is, a locally thin portion does not occur, the strength can be maintained, and the product value increases. Further, the circular shape is the simplest shape, and it is easy to produce a mold including a mold as well as an injection molding method. On the other hand, the octagon is also excellent in design.
The planar shape of the magnet holder of the present invention is not limited to these shapes. For example, the magnet holder may have an elliptical shape as long as the ratio of the major axis to the minor axis does not deviate significantly from 1. Alternatively, a polygon such as a hexagon or a decagon can be selected.
[0026]
When the planar shape is a circle, the diameter is preferably 10 mm or more. The magnetic energy product indicating the magnetic attractive force of a rare earth magnet is large, and even a magnet suitable for embedding in a main body having a diameter of 10 mm, for example, a magnet having a diameter of less than about 5 mm has sufficient holding power, but is difficult to grasp if the main body diameter is too small. This is because it becomes difficult to remove. More preferably, the diameter is 15 mm or more. Even if the magnet holder of the present invention has a large diameter and a large magnet is embedded proportionally, the maximum diameter is not particularly defined because it is easy to remove. However, even if it is small, it has a sufficient magnetic attraction force. As it increases, the area to cover up increases when fixing the posting on the object to be posted, and the cost performance decreases. .
[0027]
As a plan view shape, an octagon that is mirror-symmetrical to the center line in the vertical direction and is also mirror-symmetrical to the center line that is orthogonal to the center line, for example, a regular octagon or a vertical or horizontal expansion or reduction at a certain ratio. A deformed figure can be mentioned. However, since the symmetry increases, the deformation rate of expansion or contraction at that time is preferably within 0.7 to 1.4, more preferably within 0.8 to 1.2.
[0028]
In the case of an octagon, a regular quadrangle or a rectangle that is extended in one direction is a basic shape, and a shape in which the four corners are cut to be mirror-symmetric with respect to the vertical and horizontal center lines of the rectangle is also desirable. Can be selected. Also in this case, it is desirable that the range in which the basic rectangle does not deviate significantly from the regular square, that is, the ratio a / b of the long side a and the short side b of the rectangle is 1.4 or less.
[0029]
The size of these octagons is the same as in the case of a circle, and if it is too small, it is difficult to grasp and difficult to remove. ₁ And width W in side view ₂ The smaller value is 10 mm or more, more preferably 15 mm or more. The maximum size is not specified, but for the same reason as in the case of a circle, W ₁ And W ₂ The larger value is about 50 mm or less.
In the present invention, the front view and the side view shape are the most important, and the plan view shape is not limited to the above example as described above.
[0030]
In the magnet holder of the present invention, the convex curve on the lower side in the front view and the convex curve on the upper side in the side view are mirror-symmetric with respect to the respective center lines, thereby distinguishing between the vertical and horizontal directions. Can be further improved. In addition, although the example of the curve containing the part which is circular arc and ellipse and has the largest curvature radius was already given as these curves, these curves satisfy | fill the conditions used as mirror symmetry with respect to a centerline.
[0031]
Further, in the case of the magnet holder of the present invention, when the plan view shape of the main body is a 90-degree rotationally symmetric figure such as a circle or a regular octagon, the horizontal direction is 90 on the basis of the drawing drawn on the horizontal plane. By selecting a shape in which the front view and the side view when drawn in a state of being rotated and turned upside down match the original front view and side view, respectively, there is no distinction between front and back, and usability can be further improved. .
[0032]
Next, the rare earth magnet embedded in the central part of the main body of the magnet holder of the present invention will be described.
As these magnets, for example, a disk-shaped magnet, a ring-shaped magnet, or a regular quadrangular prism-shaped magnet magnetized in the thickness (height) direction can be used. In addition, as a ring-shaped magnet used for the magnet holder of the present invention, a magnet having a small inner diameter ID relative to the outer diameter OD is desirable. For example, when ID / OD = 0.5 or less, the magnetic attractive force is not significantly different from that of a disk having an outer diameter of OD and can be used without any trouble.
[0033]
In addition to the magnet holder in which one rare earth magnet is embedded as described above, a configuration in which two or more rare earth magnets are stacked in series in the thickness direction may be employed. In general, rare earth magnets have many magnets that are thin in the magnetizing direction for their size. By using such a configuration, especially used magnets and scrap generated in the magnet manufacturing process can be reused as raw materials. In this case, the range of materials that can be used is expanded, and material costs can be reduced.
[0034]
Alternatively, as shown in FIG. 5, for example, two disc-shaped, ring-shaped or quadrangular prism-shaped rare earth magnets which are manufactured and magnetized so as to be magnetically oriented in the thickness direction and a soft magnet inserted between them. It is also possible to use magnetic material yokes arranged in series in the thickness direction. In this case, by adjusting the thickness of the yoke, the total thickness including the rare earth magnet and the yoke can be adjusted according to the thickness of the main body. Furthermore, by making the area of the yoke 30 slightly larger or smaller than the area of the magnet, for example, it is possible to firmly fix the yoke 30 to the magnet holder without using any adhesive. FIG. 5 shows an example in which the disk-shaped rare earth magnet 12 is used and the diameter of the yoke 30 inserted between them is slightly smaller than the magnet diameter.
[0035]
By the way, in the case of a magnet holder in which a concave portion is provided on the back surface of an existing plastic body and an Nd magnet is fixed to the portion with an adhesive (see FIG. 11) (see FIG. 11), the magnetic adsorption force of the Nd magnet is extremely strong. At the same time, the strength of the adhesive does not withstand the adsorption force to the object to be displayed, and the adhesive part peels off, or the plating film of the magnet peels off, and the magnet falls off, which is likely to cause problems. In the case of the magnet holder configured as described above according to the present invention, it can be fixed to the main body using the magnetic attraction force itself, so that such a problem can be avoided.
[0036]
In the case of using a material wider than the magnet area as a yoke sandwiched between two magnets, for example, when the main body is made by injection molding, the portion in which the magnet is embedded may be a cavity and the yoke may be integrally molded. Thereafter, a magnet may be inserted into the cavity. On the other hand, when using a material narrower than the magnet area as a yoke sandwiched between two magnets, a cavity suitable for embedding these materials should be provided in the main body in advance when manufacturing the main body by a method such as injection molding. These materials can be inserted later. Thus, it becomes possible to manufacture easily, and at the same time, reliability and durability as a magnet holder can be improved.
[0037]
As another method of the magnet holder of the present invention, as shown in FIG. 6, two rectangular parallelepiped rare earth magnets 13a and 13b magnetized in the thickness direction are combined so that the SN magnetic poles are in close contact with each other and are orthogonal to each other. The magnetic pole surface on the side opposite to the contact surface may be embedded in such a way that it is at the same or slightly recessed position on both surfaces of the main body. When the dimension of the magnet is vertical width a × horizontal width b × thickness c, a> b, and the magnetization direction is the thickness c direction, as shown in FIG. The magnet is embedded in the main body so that it matches the b direction of the upper magnet and the a direction of the upper magnet, and therefore, in the side view, the left-right direction matches the b direction of the upper magnet and the a direction of the lower magnet. Constitute. By adopting such a configuration, it is possible to widen the curved surface, and thus to widen the swing range, and the usability is improved. FIG. 6 shows an example in which the central portion of the curved surface is a flat surface and the width of the central flat surface is slightly larger than b.
[0038]
In the case of the magnet holder having the above-described structure, a main body prepared in advance by a method such as injection molding so that a portion in which the magnet is embedded becomes a cavity is prepared, and two magnetized magnets are connected to each other with the SN poles in the cavity portion. A magnet holder is completed by inserting one piece from each side in such a direction as to attract. Since the magnets are strongly magnetically attached to each other, they can be fixed to the main body without using any adhesive. In this way, the magnet holder can be manufactured very easily. Further, an adhesive may be used to reinforce the magnet. In addition, you may integrally mold with a main body so that a magnet may be integrated beforehand.
[0039]
In addition to the above configuration, a yoke made of a soft magnetic material substantially equal to the longitudinal width a × the lateral width b of the magnet can be inserted inside each rectangular magnet. In such a configuration, it is possible to adjust the total thickness (t + ty) of the magnet and the yoke by adjusting the thickness ty of the yoke. Therefore, it becomes easy to adjust the total thickness to the depth of the cavity of the main body. . That is, the degree of freedom of the magnet thickness t is increased and the range of usable magnets is expanded. In addition, by doing this, for example, one yoke is inserted into the cavity of the main body from both sides in advance, the two yokes are joined by a method such as spot welding, and the magnetic attraction force is utilized for these yokes. By simply attaching a magnet, the magnet can be firmly fixed to the main body.
The magnet holder of the present invention is not limited to the above-described configuration. For example, an example in which a yoke having a vertical width b × horizontal width b is inserted between two rectangular magnets having a vertical width a × horizontal width b, and a yoke is further provided. The case where two rectangular magnets are separated from each other without intervention is also included.
[0040]
Further, for all the magnet holders described so far, for example, as shown in FIG. 7, for example, two magnets 31a and 31b made of a soft magnetic material sandwich both sides of the magnet, and the outside of each yoke is a magnet. It can be configured to be embedded in the main body so as to be substantially flush with the respective surfaces of the holder main body.
With such a configuration, the magnet is not exposed to the outside. Rare earth magnets are generally brittle and generally have poor corrosion resistance, depending on their composition. Therefore, surface treatment such as Ni plating is usually performed. However, depending on the use state of the magnet holder, when the magnet is exposed, the plating may be peeled off and rust may be generated.
By setting it as the above structures, a magnet will not be exposed from the surface and durability can be improved further. In addition, in the case of a yoke made of a soft magnetic material, the workability is good, and it is easy to make a shape that matches the surface shape of the magnet holder body. Thereby, the degree of freedom of the shape of the main body is increased.
[0041]
For example, the shape of the main body is not limited by the shape of the magnet, but as a simple curved surface, if the outer sides of the yokes 31a and 31b are matched to the curved surface of the main body as in the example shown in FIG. It becomes possible to produce a magnet holder that can swing smoothly for removal. Further, if the areas of the yokes 31a and 31b are made larger than the area of the magnetic pole face of the rare earth magnet 10, the magnet can be fixed to the main body only by the magnetic attraction force, and the magnet holder having the magnet fixed to the main body more firmly can be obtained. Fabrication is possible. However, in this case, if the yoke area is made larger than the magnet area, the magnetic attractive force is weakened. Therefore, it is desirable that the rate of increase of the yoke area with respect to the magnet area is kept within 30%.
[0042]
In addition, in the magnet holder of the present invention, as shown in FIG. 8, both magnetic pole surfaces of the rare earth magnet 14 magnetized in the thickness direction are sandwiched between two plate-shaped yokes 32a and 32b made of soft magnetic material. It is also possible that the end face is exposed on substantially the same plane as both surfaces of the magnet holder body. In the case of a magnet other than this method, the magnetization direction is all the thickness direction of the magnet holder main body 28a, whereas in this method, the magnetization direction of the magnet is a direction perpendicular to the thickness direction of the main body. Both N poles and S poles appear on both surfaces through yokes.
[0043]
Further, in the above system, the magnet is completely embedded in the main body by designing so that the magnet does not protrude from the yoke. Since the magnet is thus shielded from the outside air, for example, the magnet can be reduced without being corroded even if the magnet is not plated. Strictly speaking, it is only necessary to select a magnet having a shape and dimension that does not protrude only from the upper end surface and the lower end surface of the yoke, and all such magnets can be used in the magnet holder of this system. Two or more magnets can be used in parallel or in series. As described above, the wide selection range of the magnet is also a great advantage of the magnet holder of this system.
[0044]
As shown in the example shown in FIG. 8B, when the lower end surface 32c of the yoke is formed with a curved surface in accordance with the main body, it can be swung with a very small force, and a sufficient magnetic attractive force can be obtained. Maintenance and usability are further improved.
In addition, as a yoke material, the cold rolled steel plate prescribed | regulated to the electromagnetic soft iron plate prescribed | regulated to magnetic JISC2504 and JISG3141, for example can be used. Alternatively, ferritic stainless steel such as SUS430, which is magnetic stainless steel, can be used. In particular, ferritic stainless steel with reduced interstitial impurity elements such as C and N such as SUS444 can be selected as a more optimal material. In particular, ferritic stainless steel has excellent corrosion resistance and has an advantage that it can be used without being subjected to surface treatment such as plating.
[0045]
By the way, most of Nd-based magnets of typical rare earth magnets are used in a voice coil motor (VCM) which is a drive mechanism of a head of a hard disk drive. In the case of a VCM magnet, quality requirements are strict and the incidence of non-standard products is large. Therefore, the proportion of VCM magnets is overwhelmingly large among magnet scraps. In addition, recovery and reuse of VCM magnets from used HDDs is also an important issue. However, in the case of a VCM magnet, it has a fan-shaped special shape, and recovery and reuse are more difficult than a magnet with a relatively simple shape such as a disk shape, a ring shape, or a rectangular parallelepiped shape.
[0046]
In the case of a magnet sandwiched between the yokes, for example, a magnet cut out from a VCM magnet 40 having a shape as shown in FIG. 9 can be used effectively. FIG. 9 (b) shows a method of cutting the magnet cutting pieces 15a and 15b in a straight line by using the portion including the rounded portion outside the VCM magnet as it is, and FIG. 9 (c) shows that the cutting yield is improved. The purpose is a method in which the VCM magnet 40 is substantially parallel to the rounded portion of the VCM magnet 40, for example, cut into a curved shape by a method such as wire cutting, and further divided and used as the magnet cutting piece 16. (d) emphasizes cutting efficiency. Then, it is a method of first cutting with a multi-saw and then cutting the end in a direction perpendicular to the cutting direction to finally obtain a rectangular parallelepiped magnet cutting piece 17.
Note that the rectangular parallelepiped magnets (magnet cut pieces 15b and magnet cut pieces 17) obtained by the cutting method of FIG. 9 (d) or (b) are magnets using two rectangular parallelepiped magnets shown in FIG. It can also be used for holders.
[0047]
Industrially produced rare earth magnets include SmCo magnets in addition to Nd magnets. The former is more suitable as a magnet holder of the present invention because it has excellent magnetic properties, is inexpensive and has excellent mechanical properties.
These rare earth magnets are generally manufactured using powder metallurgy. That is, it is manufactured through processes such as fine pulverization of raw material alloy, molding in a magnetic field, sintering, heat treatment, and surface treatment. The rare earth magnet used for the magnet holder of the present invention can also be manufactured using a similar method. Furthermore, as shown in the example of the VCM magnet, it can be manufactured by cutting, grinding, or the like using as a raw material magnet scrap generated due to plating defects, corner cracks, dimensional defects, etc. in the magnet manufacturing process. it can. Or the magnet scrap taken out from the used apparatus can also be used.
[0048]
When a rare earth magnet is used for office supplies such as the magnet holder of the present invention, the quality standard for magnetic properties is very loose and the standard for dimensional accuracy and the like is loose compared to industrial applications. The magnet holder of the present invention can be used in various shapes or sizes, and is suitable as a rare earth magnet scrap loosening method.
[0049]
Conventionally, as a recycling method of such Nd-based magnet scrap, a remelting method (eg, Japanese Patent Laid-Open No. 08-31624) and a technique of pulverizing and returning to the magnet manufacturing process (eg: Japanese Patent Laid-Open No. 06-340902) have been proposed. Yes. However, since the yield is extremely poor and the characteristics of the obtained magnet are deteriorated, it has not been established as an economical method in reality. In order to reduce the global environmental load, it is desired to establish an effective recycling technique and a Ruth technique for these Nd-based magnets, and the present invention also complies with such a purpose.
[0050]
Nd-based magnets generally contain about 30 to 32 wt% of rare earth elements such as Dy and Pr as well as chemically active Nd, and therefore generally have poor corrosion resistance. For this reason, it is desirable to take rust prevention measures such as nickel plating after cutting and grinding. For some Nd-based magnets, a magnet added with Co is becoming mainstream for the purpose of improving the heat resistance as well as the corrosion resistance. In such a magnet, when used as a magnet holder as in the present invention, nickel It is also possible to use a method such as painting without plating.
[0051]
In particular, when the magnetic pole surfaces of the rare earth magnet as shown in FIG. 7 are covered with a yoke made of a soft magnetic material, or in the form of two plates so as to sandwich the magnetic pole surfaces of the rare earth magnet as shown in FIG. If the yoke is sandwiched and the end surface of the yoke is exposed on the same surface as both surfaces of the magnet holder body, the magnet is embedded in the body made of plastic or other material and is not directly exposed to the outside air. It can withstand use without surface treatment such as
【Example】
[0052]
Hereinafter, embodiments of the magnet holder of the present invention will be described in more detail using examples. In addition, as a method for measuring the holding force of the produced magnet holder, the following two methods were employed.
[0053]
(Test method 1)
As a simple and practical method, using a steel white board set in the vertical direction, the top of the A4 size copy paper was pressed with a magnetic holder, and the number of sheets fixed and held was examined. In addition, the weight per sheet of A4 size paper used for the test was 4.2 g, and the thickness was 0.083 mm.
[0054]
(Test method 2)
The upper end of the same copy paper used in Test Method 1 was fastened with a binder clip, and this clip was magnetically attracted to the upper surface of a magnet holder fixed to the whiteboard to examine how many copy papers could be held. However, the smallest binder clip (made by Lion Corporation: Binder Clip No. 105) was selected from those commercially available as office supplies.
Further, it was examined how many sheets of A4 size paper can be held using a gem clip instead of a binder clip. A gem clip having an outer width of 6.3 mm and a length of 23.5 mm, which is widely used as office supplies, was used. However, the number of sheets that can be fixedly held by this gem clip is about 20, and if it exceeds that, the sheet will fall with the gem clip remaining in the magnet holder, so in that case “≧ 20 sheets” is displayed.
[0055]
(Example 1) (Refer FIG. 1)
Using an acrylic resin disk with a diameter of 25 mm and a thickness of 4.5 mm as a raw material, the surfaces on both sides intersect each other by 90 °, and the curvature radius is 50 mm near the center and the curvature radius near the center is 30 mm. Grinded. Further, a drill hole having a diameter of 10 mm was formed in the center to obtain a main body 21a. The thickness of the periphery of the main body after processing was 2.2 mm at the thinnest portion and 2.4 mm at the thickest portion, and had almost the same appropriate thickness. The swing angle θ was about 22 degrees.
Next, an Nd-based sintered magnet 10 having a diameter of 10 mm, a thickness of 4 mm, and a magnetization direction in the thickness direction is inserted into a drill hole at the center of the main body 21a, and fixed with an epoxy-based adhesive. The magnet holder 21 shown in FIG.
[0056]
The holding power of the magnet holder 21 was examined by the test method 1 and the test method 2. As a result, as shown in Table 1, it was found that Test Method 1 has a sufficient holding power of 16 sheets of A4 paper. In particular, in Test Method 2, it can be seen that 20 or more A4 sheets can be fixedly held even when fastened with a small clip such as a gem clip, as well as a binder clip, and has a strong holding force. It was.
[0057]
[Table 1]

[0058]
In addition, even though it has such a strong holding force, even if it is fastened directly to the whiteboard without using paper, it swings because the magnetic attracting surface is formed with a downwardly convex curved surface. The upper part of the end part with a gap on the bottom surface was pushed with the index finger and the other end part was lifted with the thumb, so that the magnet holder was raised, grasped with both fingers, and easily removed. In addition, it was found that the post can be inserted and removed very easily by pushing the upper end while the magnet holder is attracted to the post.
(Example 2) (Refer FIG. 2)
Using an acrylic resin disk having a diameter of 25 mm and a thickness of 4.0 mm as a raw material, the surfaces on both sides intersected each other by 90 ° to leave a center width of 10 mm, and were ground into a curved surface so that the curvature radius was 30 mm. Further, a drill hole having a diameter of 10 mm was formed in the center to obtain a main body 22a. The thickness of the periphery of the main body after processing was 2.1 mm at the thinnest part and 2.2 mm at the thickest part, and had the same appropriate thickness. The swing angle θ was about 25 degrees.
Next, the Nd-based sintered magnet 10 magnetized in the same manner as in the first embodiment is inserted into a drill hole formed in the central portion of the main body 22a, fixed with an epoxy-based adhesive, and schematically shown in FIG. 22 was obtained.
[0059]
The holding power of the magnet holder 22 was examined by the test method 1 and the test method 2. As a result, as shown in Table 1, it was found that all the test results had sufficient holding power. In particular, since the distance between the magnetic pole surface and the object to be displayed is closer than in the case of Example 1, it has been found that the holding force slightly exceeds the magnetic attraction force of the magnet holder 21.
Furthermore, even when the paper is not directly used and is fastened directly to the whiteboard, the magnetic attraction surface is formed with a curved surface that protrudes downward except for a part of the center portion, so that it is easy to swing and detachable. there were. In addition, it was found that the post can be inserted and removed very easily by pushing the upper end while the magnet holder is attracted to the post.
[0060]
(Example 3) (Refer FIG. 4)
A plate made of acrylic resin having a side of 30 mm and a thickness of 6.0 mm was used as a material. As shown in FIG. 4, the corners of the four corners of the material plate are cut off and processed into a regular octagon with an opposite side distance of 30 mm, and the central portion with a width of 10 mm is left flat and is 20 ° from the plane. Both sides were ground. Similarly, the opposite surfaces were also ground so that the convex curved surfaces intersect each other by 90 °. Further, a drill hole having a diameter of 8 mm was formed in the center to obtain a main body 24a. The peripheral thickness after processing was 2.2 mm at the thinnest portion and 2.4 mm at the thickest portion, and had the same moderate thickness.
Next, a φ8 mm × t6 mm Nd-based sintered magnet 11 magnetized in the thickness direction is inserted into a hole formed in the center of the main body 24a, and fixed with an epoxy-based adhesive, which is schematically shown in FIG. Thus, the magnet holder 24 was obtained.
[0061]
With respect to the magnet holder 24, the holding force was examined by Test Method 1 and Test Method 2. As a result, as shown in Table 1, although the magnet shape was different, it had almost the same sufficient holding force as the magnet holder 22 using the magnet 10 having almost the same volume. Further, even when the paper is not directly used but is fastened directly to the whiteboard, the magnetic attraction surface is formed as a downwardly convex curved surface, so that it is easy to swing and detachable. In addition, it was found that the post can be inserted and removed very easily by pushing the upper end while the magnet holder is attracted to the post.
[0062]
(Comparative Example 1)
Using the same Nd-based sintered magnet 10 used as the material of Example 1 and Example 2, the holding force was examined by Test Method 1 and Test Method 2 as they were. As a result, as shown in Table 1, the holding force was the same as in Example 2. However, when attached to the whiteboard, it could not be removed with bare hands. In order to remove it, it was necessary to remove it with tools such as pliers, which was extremely inconvenient.
[0063]
(Comparative Example 2)
A magnet holder was prepared in the same manner as in Example 2 except that the same Nd-based sintered magnet 10 as that used in Example 1 and Example 2 was used and only one side was left flat. . When the side processed into a curved surface was a magnetic adsorption surface, it was rocked in the same manner as in Example 2, so that it was easy to detach. However, when the flat surface is an attracting surface, although it is easier than Comparative Example 1 in which the magnet is used as it is, it is a situation that can be forcibly removed with bare hands and is extremely difficult to use.
[0064]
(Comparative Example 3)
Using a commercially available magnet holder 50 (made by KOKUYO, trade name “Color Magnet”) shown in FIG. 11 in which a strong magnet 16 is fixed to a hollow portion opened at an eccentric position on one side of a plastic disk 50a with an adhesive. Tests were performed in methods 1 and 2. The outer diameter of the disk 50a was 30 mm and the thickness was 6.2 mm. The magnet 16 was taken out and the dimensions were measured. As a result, the diameter was 10 mm × thickness 2 mm. Further, it was found by component analysis or the like that the magnet 16 is an Nd-based sintered magnet.
As shown in Table 1, the holding force test results show that the magnet holder 50 has a sufficiently practical holding force in Test Method 1 although its holding force is smaller than that of the magnet holders 21 to 23 of the present invention. . However, it was found that Test Method 2 shows almost no holding force, and that the method of use is limited despite the use of a strong Nd-based sintered magnet.
In addition, during repeated use, the plating peeled off and the magnet fell off from the main body, resulting in a high frequency of use.
[0065]
(Example 4) (Refer FIG. 5)
In the same manner as in Example 2, using a disc material made of acrylic resin having a diameter of 30 mm and a thickness of 5.5 mm, the surfaces on both sides intersect each other by 90 °, leaving a width of 10 mm at the center, and a radius of curvature near the center. Grinding was performed so as to obtain a curved surface continuously changing from 50 mm to 30 mm in the peripheral portion. Further, a through hole having a diameter of 8 mm was first formed in the center, and then a hole having a diameter of 10 mm was formed from both sides using an end mill to a depth of 2 mm to obtain a main body 25a. The thickness of the periphery of the main body after processing was 2.8 mm at the thinnest part and 2.9 mm at the thickest part, and had almost the same appropriate thickness. The swing angle θ was about 25 degrees.
Next, a yoke 30 made of electromagnetic soft iron having a diameter of 8 mm and a thickness of 1.5 mm is inserted into the central portion of the hole in the center of the main body 25a, and further, the diameter is 10 mm, the thickness is 2 mm, and the magnetization direction is thick. One Nd-based sintered magnet 12 in the vertical direction was inserted from both sides of the main body 25a to obtain a magnet holder 25 schematically shown in FIG.
[0066]
With respect to the magnet holder 25, the holding force was examined by Test Method 1 and Test Method 2. As a result, as shown in Table 1, it was found that all the test results had sufficient holding power. The magnet volume was the same as the magnet holders 21 to 23, but it was found to have a slightly higher holding force.
Furthermore, even when the paper is not directly used and is fastened directly to the whiteboard, the magnetic attraction surface is formed with a curved surface that protrudes downward except for a part of the center portion, so that it is easy to swing and detachable. there were. In addition, it was found that the post can be inserted and removed very easily by pushing the upper end while the magnet holder is attracted to the post.
[0067]
(Example 5) (Refer FIG. 6)
Two Nd-based sintered magnets 13 having a rectangular parallelepiped shape having a width of 6.0 mm, a length of 12 mm, and a thickness of 3.0 mm were prepared as materials. However, the orientation direction during magnetic field molding is the thickness direction.
Next, a main body portion 26a having a shape as schematically shown in FIG. 6 was produced by injection molding using acrylic resin. The dimensions were a diameter of 30 mm and a maximum thickness of 6 mm, and each surface was molded so that the radius of curvature in the vicinity of the central portion was 40 mm and the radius of curvature in the peripheral portion was 30 mm, except for the width of 8 mm at the central portion. At the time of molding, cavities for accommodating the magnets were built on both sides.
The magnetized magnets 13a and 13b were inserted into the cavity from both sides to obtain a magnet holder 26. The thickness of the circumference of the main body was 2.8 mm at the thinnest part and 3.0 mm at the thick part, and had the same moderate thickness. The swing angle θ was about 27 degrees.
[0068]
The holding power of the magnet holder 26 was examined by the test method 1 and the test method 2. As a result, as shown in Table 1, it was found to have a sufficient holding force. In addition, the width of the flat part is narrow and the curved surface is wide, so it is easy to swing, and not only the magnet holder can be easily attached and detached, but also by pressing the upper end with the magnet holder attracted to the display object, It was found that it was very easy to insert and remove the posting.
[0069]
(Example 6) (Refer FIG. 7)
Using an acrylic resin disk with a diameter of 25 mm and a thickness of 5.0 mm as a raw material, the surfaces on both sides intersect each other 90 degrees, and the curvature radius near the center is 50 mm, and the curvature radius at the periphery is 30 mm. Grinded. Next, a drill hole having a diameter of 11 mm and a depth of 0.5 mm was opened from both sides in the center using an end mill, and a drill hole having a diameter of 10 mm was further penetrated to obtain a main body 27a. The thickness of the periphery of the main body after processing was 2.5 mm at the thinnest part and 2.9 mm at the thickest part, and had almost the same appropriate thickness. The swing angle θ was about 22 degrees.
Next, the same Nd-based sintered magnet 10 as in Example 1 is inserted into a drill hole having a diameter of 10 mm at the center of the main body, and disk-shaped yokes 31a and 31b made of SUS444 having a diameter of 11 mm and a thickness of 0.5 mm from both sides. And then fixed with an epoxy adhesive. Furthermore, the yoke was ground in accordance with the surface shape of the main body to obtain a magnet holder 27 schematically shown in FIG.
[0070]
After magnetizing the magnet holder 27, the holding force was examined by Test Method 1 and Test Method 2. As a result, as shown in Table 1, although it was slightly inferior to the magnet holders 22 and 23 using the same magnet, it had a sufficient holding force. Furthermore, since the magnet 10 of this type is covered with the yoke 31, the magnet is not affected at all even if it is slid on a metal surface or used severely. Moreover, since the magnet was firmly fixed to the main body even by magnetic force, it was found that the magnet did not fall off and was excellent in durability.
In addition, even when the paper is not directly used and is fastened to the whiteboard, the magnetic attraction surface is formed with a smooth convex convex curved surface, so that it is easy to swing and detachable. In addition, it was found that the post can be inserted and removed very easily by pushing the upper end while the magnet holder is attracted to the post.
[0071]
(Example 7) (Refer FIG. 8)
A steel plate of ferritic stainless steel SUS444 having a thickness of 1.2 mm is used as a raw material, cut into a rectangle having a width of 8 mm × 15 mm, and the end surface on one side in the length direction of 15 mm is ground to a curvature radius of 35 mm to obtain a yoke 32. . A silicon rubber mold prepared in advance by magnetizing a rectangular parallelepiped Nd magnet 13 having an orientation direction of a thickness direction and dimensions of 3 mm thickness × width 5 mm × length 10 mm, and setting the yoke 32 on both sides. Was used to pour a commercially available polyester resin (“Polytel” manufactured by Dobetsu Resin Handicrafts Laboratory Co., Ltd.) to produce a magnet holder 28 having a shape schematically shown in FIG. The diameter of the main body 28a is 30 mm. Further, after casting, the lower curve of the main body 28a in the front view of FIG. 8B was finished by grinding so that the radius of curvature of the central portion was 35 mm and the peripheral portion was a smooth curve of about 25 mm. On the other hand, the upper curve of the body 28a in the side view of FIG. 8 (c) was finished by post-molding grinding so that about 5 mm at the center is a flat surface and both sides thereof are curved surfaces with a curvature radius of about 30 mm. The thickness of the central part of the main body a after grinding is 7.5 mm, the thickness of the peripheral part is 3.4 mm at the thinnest part and 3.6 mm at the thickest part, and has the same and sufficient thickness. It was. The swing angle θ was about 29 degrees.
[0072]
With respect to the magnet holder 28, the holding force was examined by Test Method 1 and Test Method 2. As a result, as shown in Table 1, it was found that all the test results had sufficient holding power. In particular, it was found that when the white board was fixed so that the lower side shown in the front view was an adsorption surface, it was rocked with an extremely small force, and it was easy to attach and detach the posting. When the opposite side is the attracting surface, as shown in () in the lower part of Table 1, the entire surface of the end face of the yoke, which is 20 sheets and the magnetic pole, is in close contact with the posted material. It was known that power became stronger. Due to these features, both sides can be used properly according to the purpose of use.
[0073]
【The invention's effect】
As described above, the magnet holder of the present invention can be easily detached from the display object despite having a very large magnetic attractive force. Moreover, the front side of the magnet holder also has a magnetic attractive force. Therefore, the paper fastened with a general-purpose fastener such as a binder clip has a feature that it can be fixed with a sufficient holding force by adsorbing these magnetic parts to the upper surface of the magnet holder. In addition, magnetic attraction works just by bringing them closer, and they can be fixed very easily. Furthermore, it can be easily removed by pulling the paper. Further, by swinging the magnet holder, it is possible to attach and detach the postings, and the usability is extremely good.
[0074]
Furthermore, in order to reduce the burden on the global environment by making effective use of Nd-based magnet scrap generated in large quantities from Nd-based magnet production processes or from used home appliances and electronics-related equipment, and enabling recycling and recycling. Although it is useful and valuable and expensive Nd-based magnets are used, the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a magnet holder according to a first embodiment of a magnet holder of the present invention by a third angle method.
FIG. 2 is a view showing a magnet holder according to a second embodiment of the present invention by a third angle method.
FIG. 3 is a diagram showing another embodiment of the present invention by the third angle method.
FIG. 4 is a diagram showing a magnet holder according to a third embodiment of the present invention by a third angle method.
FIG. 5 is a view showing a magnet holder according to a fourth embodiment of the present invention by a third angle method.
FIG. 6 is a diagram showing a magnet holder according to a fifth embodiment of the present invention by a third angle method.
FIG. 7 is a view showing a magnet holder according to a sixth embodiment of the present invention by the third angle method.
FIG. 8 is a view showing a magnet holder according to a seventh embodiment of the present invention by the third angle method.
FIG. 9 is a schematic diagram showing a method of cutting out a magnet used for a magnet holder of the present invention from a VCM.
FIG. 10 is a diagram showing an example of a magnet holder in which curved surfaces face each other without crossing 90 degrees.
FIG. 11 is a view showing a magnet holder according to Comparative Example 3 by a third angle method.
[Explanation of symbols]
10, 11, 12, 13, 14, 15, 16: Rare earth magnet
40: VCM magnet
21, 22, 23, 24, 25, 26, 27, 28, 29, 50: Magnet holder
30, 31, 32: York

Claims (6)

  The main body is made of a non-magnetic material, the upper and lower surfaces are formed by convex curved surfaces intersecting each other by 90 degrees, and the rare earth magnet is at the center of the main body and the magnetic pole surface is directly or via a soft magnetic material yoke. A magnet holder that is embedded so that both surfaces are almost the same or slightly recessed.   The shape of the main body in the drawing drawn by the trigonometric method with the main body made of a non-magnetic material and placed on a horizontal surface so that the magnetic adsorption surface is on the bottom is as follows. A convex curve is formed, and the contour line on the upper surface is a flat straight line, or (b ') a lower central part is a straight line that touches the horizontal line, and both left and right sides are formed by convex curves downward, and the contour of the upper surface The line is a flat straight line, or (b) the lower center is a straight line that touches the horizontal line, and the left and right sides form a straight line that forms 10 to 40 degrees with the straight line. In the side view, (b) the upper part forms a convex curve upward, and the lower outline is a straight line that touches the horizontal line, or (b ') part of the upper central part is parallel to the horizontal line. A straight line with left and right sides that are convex upward, and the lower outline touches the horizontal line. The upper central part is a straight line parallel to the horizontal line, and both left and right sides are formed by a straight line forming 10 to 40 degrees with respect to the central straight line, and the lower outline touches the horizontal line. (C) The rare earth magnet is embedded in the center of the main body so that its magnetic pole surface is directly or through a yoke made of soft magnetic material so that it is in the same or slightly recessed position on both surfaces of the main body. A magnet holder characterized by   3. The magnet holder according to claim 1, wherein the magnet holder is an octagon having a mirror symmetry with respect to a center line perpendicular to the circular or vertical center line in a plan view.   2. The rare earth magnet is composed of one rare earth magnet magnetized and magnetized so as to be magnetically oriented in the thickness direction, or two or more rare earth magnets stacked in the thickness direction. The magnet holder of any one of Claim 3.   Two rectangular parallelepiped magnets magnetized in the thickness direction are combined so that the SN magnetic poles are in close contact with each other or close to each other and perpendicular to each other. The magnet holder according to any one of claims 1 to 3, wherein the magnet holder is embedded so as to be in the same or slightly recessed position.   The magnet holder according to any one of claims 1 to 5, wherein the rare earth magnet is an Nd-based sintered magnet.

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