JPH09293623A - Forming method of magnetic particle - Google Patents
Forming method of magnetic particleInfo
- Publication number
- JPH09293623A JPH09293623A JP13084796A JP13084796A JPH09293623A JP H09293623 A JPH09293623 A JP H09293623A JP 13084796 A JP13084796 A JP 13084796A JP 13084796 A JP13084796 A JP 13084796A JP H09293623 A JPH09293623 A JP H09293623A
- Authority
- JP
- Japan
- Prior art keywords
- molding
- magnet powder
- core rod
- filling
- molding space
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0273—Imparting anisotropy
- H01F41/028—Radial anisotropy
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ラジアル異方性リ
ング磁石製造の際の成形方法に関し、より詳しくは、成
形工程において磁石粉末を成形空間内に充填する方法に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method for manufacturing a radial anisotropic ring magnet, and more particularly to a method for filling a molding space with magnet powder in a molding process.
【０００２】[0002]
【従来の技術】スピンドルモータなどに使用されるラジ
アル異方性リング磁石は、磁石の高性能化および組み込
まれるモータの小型化への要求から、小型化、薄肉化の
傾向にある。2. Description of the Related Art Radial anisotropic ring magnets used in spindle motors and the like tend to be smaller and thinner due to the demands for higher performance of magnets and smaller motors incorporated therein.
【０００３】一般に焼結磁石の製造に際しては、原料合
金を直径数ミクロン程度の粉末まで粉砕し、これを成形
装置を用いて圧縮成形した後、焼結を行う粉末冶金法が
採られている。成形装置の成形空間への磁石粉末の充填
にあたっては、磁石粉末を充填したフィーダが成形空間
上で往復運動を行うことで重力落下によって成形空間内
に磁石粉末を充填する方法（いわゆる摺り切り充填方
法）が採用されている。Generally, in the production of sintered magnets, a powder metallurgy method is used in which a raw material alloy is pulverized into powder having a diameter of about several microns, compression molding is performed using a molding device, and then sintering is performed. When the magnet powder is charged into the molding space of the molding device, a method in which a feeder filled with the magnet powder reciprocates in the molding space to gravitationally drop the magnet powder into the molding space (a so-called scraping filling method) ) Has been adopted.
【０００４】ラジアル異方性リング磁石用成形装置で
は、一般に成形空間の間口（径方向幅）に対し充填深さ
が大きいため、上記のような摺り切り充填方法では均一
な充填が難しく、特に、流動性が比較的悪い合金粉末の
場合には充填にばらつきが生じやすい。また、磁石の薄
肉化により成形空間の間口がより狭くなりつつあること
から、ばらつきの増大が顕著になっている。In a molding apparatus for a radial anisotropic ring magnet, since the filling depth is generally large with respect to the opening (width in the radial direction) of the molding space, it is difficult to perform uniform filling with the above-mentioned sliding cut filling method. In the case of alloy powder having relatively poor fluidity, the filling tends to vary. In addition, since the frontage of the molding space is becoming narrower due to the thinning of the magnet, the increase in variation is remarkable.
【０００５】ラジアル異方性リング磁石用の成形用装置
のように成形空間の間口が狭いものに対して従来の摺り
切り充填を行った場合、成形空間内の磁石粉末充填量に
は図４（ａ）に示されるような偏りが生じてしまう。図
示されるように、成形空間の径方向のうちフィーダ移動
方向と一致する方向では磁石粉末の充填は十分に行われ
るが、フィーダ移動方向に直交する方向では充填量が著
しく少なくなってしまう。圧縮成形後には高さの偏りは
なくなるが、成形体中で密度の偏りが生じているため、
図４（ｂ）に示されるようなクラックが発生しやすい。
また、密度の偏りがある成形体を焼結すると、焼成によ
り不均一な収縮が生じるため、円形のリング磁石が得ら
れない。また、焼結体内で密度や配向のばらつきが生じ
ているため、位置によって磁気特性が異なることにな
る。Ｎｄ−Ｆｅ−Ｂ系のボンド磁石では径方向厚さが１
mmを切るリング磁石が生産されているが、上記のような
事情から焼結リング磁石では薄肉化が困難であった。When the conventional scraping filling is applied to a molding machine having a narrow molding space such as a molding machine for a radial anisotropic ring magnet, the amount of the magnet powder packed in the molding space is shown in FIG. The bias as shown in a) will arise. As shown in the drawing, the magnetic powder is sufficiently filled in the radial direction of the molding space that coincides with the feeder movement direction, but the filling amount is significantly reduced in the direction orthogonal to the feeder movement direction. After compression molding, the unevenness in height disappears, but since there is uneven density in the molded body,
Cracks such as those shown in FIG. 4B are likely to occur.
Further, if a compact having a density unevenness is sintered, non-uniform shrinkage occurs due to firing, so that a circular ring magnet cannot be obtained. Further, since the density and the orientation are varied within the sintered body, the magnetic characteristics differ depending on the position. In the Nd-Fe-B system bonded magnet, the radial thickness is 1
Ring magnets with a diameter of less than mm have been produced, but it was difficult to reduce the thickness of the sintered ring magnet due to the above circumstances.
【０００６】このような充填の偏りを改善するための提
案が、例えば特開平１−１４７８１９号公報に記載され
ている。同公報で用いる成形装置は、ダイスおよびその
内部に配置されたコアと、上パンチおよび下パンチで囲
まれた円筒状の成形空間を有するものである。同公報記
載の方法では、成形空間内に強磁性粉末を充填する際
に、まず、コアを静止させた状態でダイスを上昇させる
ことにより、ダイス内に成形空間よりも大きな空間を形
成する。次いで、この空間内に強磁性粉末を充填した
後、コアを上昇させることにより、成形空間以外に充填
された強磁性粉末を排出する。A proposal for improving such a bias in filling is disclosed in, for example, Japanese Patent Laid-Open No. 1-147819. The molding apparatus used in this publication has a die and a core arranged inside the die, and a cylindrical molding space surrounded by an upper punch and a lower punch. In the method described in the publication, when filling the molding space with the ferromagnetic powder, first, the die is lifted while the core is stationary to form a space larger than the molding space in the die. Next, the ferromagnetic powder is filled in this space, and then the core is raised to discharge the ferromagnetic powder filled in the space other than the molding space.
【０００７】しかし、同公報記載の方法では、リング状
成形空間の径方向幅が小さくなると、成形空間内に残る
べき磁石粉末がコア上昇と共に押し出されてしまうよう
になり、結果として必要量の充填が困難となる。必要量
を確実に充填するためには、成形空間の深さ（充填深
さ）を大きくしなければならない。このため、成形装置
の上下パンチを長くし、また、ダイスの有効長を長くす
る必要があるので、ダイス表面での配向磁界の磁束密度
が減少してしまい、高特性の異方性磁石が得られなくな
ってしまう。However, in the method described in the above publication, when the radial width of the ring-shaped molding space becomes smaller, the magnet powder that should remain in the molding space will be pushed out as the core rises, and as a result, the necessary amount of filling will be filled. Will be difficult. In order to reliably fill the required amount, the depth of the molding space (filling depth) must be increased. For this reason, it is necessary to lengthen the upper and lower punches of the molding machine and to lengthen the effective length of the die, so that the magnetic flux density of the orientation magnetic field on the surface of the die decreases, and an anisotropic magnet with high characteristics can be obtained. I will not be able to.
【０００８】また、特開平２−７５０６号公報では、成
形空間の開口近傍にソレノイドコイルを、その中心軸方
向が成形空間深さ方向にほぼ一致する向きに設置し、交
流電流を供給して成形空間開口上方の永久磁石粉体を成
形空間内に充填する方法が提案されている。しかし、こ
の方法では、交流磁界を発生させるソレノイドコイルを
設ける必要があるため、成形装置の構造が複雑になると
いう問題がある。Further, in JP-A-2-7506, a solenoid coil is installed in the vicinity of an opening of a molding space so that its central axis direction substantially coincides with the depth direction of the molding space, and an alternating current is supplied to perform molding. A method of filling the molding space with the permanent magnet powder above the space opening has been proposed. However, this method has a problem in that the structure of the molding apparatus becomes complicated because it is necessary to provide a solenoid coil for generating an AC magnetic field.
【０００９】[0009]
【発明が解決しようとする課題】本発明の目的は、ラジ
アル異方性リング磁石製造に際し、成形装置の成形空間
内に磁石粉末をより均一に充填することにより、クラッ
ク、変形、特性不良などの発生によるリング磁石の歩留
まりの低下を抑えることであり、特に、径方向厚さの小
さいリング磁石の歩留まりを向上させることである。It is an object of the present invention to more uniformly fill the magnet powder in the molding space of the molding apparatus during the manufacture of the radial anisotropic ring magnet, so that cracks, deformation, defective characteristics, etc. This is to suppress a decrease in the yield of ring magnets due to generation, and in particular to improve the yield of ring magnets having a small radial thickness.
【００１０】[0010]
【課題を解決するための手段】このような目的は、下記
（１）〜（６）の本発明により達成される。 （１）ラジアル異方性リング磁石製造の際の成形工程に
おいて、型枠内にリング状の成形空間を介して円柱状の
コアロッドが設けられている成形装置の成形空間へ磁石
粉末を充填するに際し、磁化されたコアロッドの上部が
型枠上面から突出し、かつコアロッドに磁石粉末が磁着
している状態とした後、型枠に対し相対的にコアロッド
を下降させることにより、磁石粉末を成形空間内に引き
込んで充填を行う磁石粉末の成形方法。 （２）磁化されたコアロッド上部の型枠上面から突出し
ている高さの最大値が、成形空間への磁石粉末の充填深
さ以上である上記（１）の磁石粉末の成形方法。 （３）成形空間の径方向幅が５mm以下である上記（１）
または（２）の磁石粉末の成形方法。 （４）底面をもたない箱状のフィーダに磁石粉末を充填
し、このフィーダを成形空間の上で停止させ、このフィ
ーダ内にコアロッドを突き出して磁石粉末を磁着させる
上記（１）〜（３）のいずれかの磁石粉末の成形方法。 （５）磁石粉末充填後に成形空間の径方向の磁界を印加
して、ラジアル配向の成形体を得る上記（１）〜（４）
のいずれかの磁石粉末の成形方法。 （６）Ｒ−Ｔ−Ｂ（ＲはＹを含む希土類元素の少なくと
も１種、ＴはＦｅ、またはＦｅおよびＣｏである）系磁
石粉末の成形に適用される上記（１）〜（５）のいずれ
かの磁石粉末の成形方法。This and other objects are achieved by the present invention which is defined below as (1) to (6). (1) In filling a magnet powder into a molding space of a molding apparatus in which a cylindrical core rod is provided in a mold via a ring-shaped molding space in a molding step in manufacturing a radial anisotropic ring magnet. , After the magnetized core rod has an upper part protruding from the upper surface of the mold and magnet powder is magnetically adhered to the core rod, the core rod is moved down relative to the mold so that the magnet powder is kept inside the molding space. A method for molding magnet powder by drawing into a magnet and filling. (2) The method for molding magnetic powder according to the above (1), wherein the maximum value of the height of the magnetized core rod protruding from the upper surface of the mold is equal to or more than the filling depth of the magnetic powder into the molding space. (3) The above (1) in which the radial width of the molding space is 5 mm or less.
Alternatively, (2) the method for molding magnetic powder. (4) A box-shaped feeder having no bottom surface is filled with magnet powder, the feeder is stopped in the molding space, and the core rod is projected into the feeder to magnetically adhere the magnet powder. The method for forming a magnetic powder according to any one of 3). (5) A magnetic field in the radial direction of the molding space is applied after filling the magnet powder to obtain a radially oriented molded body (1) to (4).
1. A method for molding magnetic powder according to any one of 1. (6) R-T-B (R is at least one kind of rare earth element including Y, T is Fe, or Fe and Co) based magnet powder of the above (1) to (5) applied to molding. A method for molding any of the magnetic powders.
【００１１】[0011]
【作用および効果】本発明では、図１（ａ）に示される
ように、磁化された円柱状の下部コアロッド６の上部が
型枠２上面から突出し、かつ下部コアロッド６に磁石粉
末５が磁着している状態とした後、下部コアロッド６を
下降させる。これにより、図１（ｂ）に示されるように
磁石粉末５はリング状の成形空間内に均一に引き込まれ
るので、成形空間の径方向幅が例えば５mm以下、あるい
は３mm以下となるような薄肉リング磁石の製造に際して
も、成形空間への充填量に位置的なばらつきが生じな
い。このため、ラジアル異方性リング磁石製造の際の歩
留まりが著しく向上する。In the present invention, as shown in FIG. 1 (a), the upper portion of the magnetized cylindrical lower core rod 6 projects from the upper surface of the mold 2 and the magnet powder 5 is magnetically attached to the lower core rod 6. Then, the lower core rod 6 is lowered. As a result, as shown in FIG. 1 (b), the magnet powder 5 is uniformly drawn into the ring-shaped molding space, so that the radial width of the molding space is, for example, 5 mm or less, or 3 mm or less. Even when the magnet is manufactured, there is no positional variation in the filling amount in the molding space. Therefore, the yield at the time of manufacturing the radial anisotropic ring magnet is significantly improved.
【００１２】[0012]
【発明の実施の形態】本発明の実施の形態の構成例を、
図１の（ａ）〜（ｄ）に示す。BEST MODE FOR CARRYING OUT THE INVENTION A configuration example of an embodiment of the present invention,
It shows in (a)-(d) of FIG.
【００１３】図示される成形装置は、型枠２内にリング
状の成形空間を介して円柱状の下部コアロッド６が設け
られている。圧縮成形時には、図１（ｄ）に示されるよ
うに、円筒状の上部パンチ３の下面が成形空間の上面を
構成し、円筒状の下部パンチ４の上面が成形空間の下面
を構成することになる。上部パンチ３の内側には、円柱
状の上部コアロッド７が設けられている。下部コアロッ
ド６および上部コアロッド７の周囲には、それぞれ下部
コイル８および上部コイル９が巻回されている。下部コ
イル８と上部コイル９とは逆方向の磁界を発生するた
め、下部コアロッドを通った磁束と上部コアロッドを通
った磁束とは成形空間付近において同極が対向して反発
する。その結果、リング状成形空間の径方向に磁束が通
り、成形体にラジアル異方性を付与することができる。In the molding apparatus shown in the figure, a cylindrical lower core rod 6 is provided in a mold 2 via a ring-shaped molding space. At the time of compression molding, as shown in FIG. 1D, the lower surface of the cylindrical upper punch 3 constitutes the upper surface of the molding space, and the upper surface of the cylindrical lower punch 4 constitutes the lower surface of the molding space. Become. Inside the upper punch 3, a cylindrical upper core rod 7 is provided. A lower coil 8 and an upper coil 9 are wound around the lower core rod 6 and the upper core rod 7, respectively. Since the lower coil 8 and the upper coil 9 generate magnetic fields in opposite directions, the magnetic flux passing through the lower core rod and the magnetic flux passing through the upper core rod repel each other with the same poles facing each other in the vicinity of the molding space. As a result, magnetic flux passes in the radial direction of the ring-shaped molding space, and radial anisotropy can be imparted to the molded body.
【００１４】本発明では、磁化されたコアロッド６の上
部が型枠２上面から突出し、かつコアロッド６に磁石粉
末５が磁着している状態とした後、コアロッド６を型枠
２に対し相対的に下降させることにより、磁石粉末５を
成形空間内に引き込んで充填を行う。In the present invention, after the magnetized core rod 6 has an upper portion protruding from the upper surface of the mold 2 and the magnet powder 5 is magnetically adhered to the core rod 6, the core rod 6 is moved relative to the mold 2. Then, the magnet powder 5 is drawn into the molding space for filling.
【００１５】図１（ａ）に示されるように、磁化された
コアロッド６の上部が型枠２上面から突出し、かつコア
ロッド６に磁石粉末５が磁着している状態とする手順は
特に限定されないが、通常、以下のように行う。まず、
磁石粉末５を充填してあるフィーダ１０を成形空間の上
で停止させる。フィーダ１０は、底面をもたない箱状の
容器である。次いで、下部コアロッド６を型枠２に対し
相対的に上昇させてフィーダ内に突き出し、この状態で
下部コイル８により下部コアロッド６を励磁する。この
とき、フィーダ１０内に突出している下部コアロッド６
の上部には漏洩磁束が生じ、この磁力によって磁石粉末
が磁着される。このとき、下部コアロッド６上部の型枠
２上面から突出している高さ（下部コアロッド６上面と
型枠２上面との距離）の最大値は、成形空間への磁石粉
末の充填深さ（下部パンチ上面から型枠上面までの高
さ）以上とすることが好ましい。これにより、磁石粉末
の充填量を多くすることができる。As shown in FIG. 1A, there is no particular limitation on the procedure for setting the magnetized core rod 6 so that the upper portion of the magnetized core rod 6 projects from the upper surface of the mold 2 and the magnetic powder 5 is magnetically attached to the core rod 6. However, it is usually performed as follows. First,
The feeder 10 filled with the magnet powder 5 is stopped on the molding space. The feeder 10 is a box-shaped container having no bottom surface. Next, the lower core rod 6 is raised relative to the mold 2 and protrudes into the feeder. In this state, the lower core rod 6 is excited by the lower coil 8. At this time, the lower core rod 6 protruding into the feeder 10
A leakage magnetic flux is generated in the upper part of the magnetic field, and this magnetic force causes the magnetic powder to be magnetically attached. At this time, the maximum value of the height protruding from the upper surface of the mold 2 above the lower core rod 6 (the distance between the upper surface of the lower core rod 6 and the upper surface of the mold 2) is the filling depth of the magnet powder into the molding space (lower punch). It is preferable that the height is from the upper surface to the upper surface of the mold). Thereby, the filling amount of the magnet powder can be increased.
【００１６】次いで、下部コアロッド６を型枠２に対し
両者の上面が一致するまで相対的に下降させ、図１
（ｂ）に示す状態とする。このとき、下部コアロッド６
上部に磁着された磁石粉末５は、下部コアロッドの下降
と共に成形空間内に引き込まれる。下部コアロッドの下
降終了後、通常、下部コイルによる励磁は中止するが、
磁界中成形のときまで励磁を中断しなくてもよい。Then, the lower core rod 6 is relatively lowered with respect to the mold 2 until the upper surfaces of the two are aligned with each other.
The state shown in FIG. At this time, the lower core rod 6
The magnet powder 5 magnetically attached to the upper part is drawn into the forming space as the lower core rod descends. After lowering the lower core rod, excitation by the lower coil is usually stopped,
The excitation does not have to be interrupted until the time of molding in a magnetic field.
【００１７】次いで、フィーダ１０を成形空間の上から
移動させると共に、フィーダ１０の端部で摺り切りを行
い、図１（ｃ）に示される状態とする。Next, the feeder 10 is moved from above the molding space, and the end portion of the feeder 10 is scraped off to obtain the state shown in FIG. 1 (c).
【００１８】次いで、図１（ｄ）に示されるように、上
部コアロッド７および上部パンチ３を下降させ、上部コ
アロッド７が下部コアロッド６と接した後、上部パンチ
３をさらに下降させると共に下部コイル８および上部コ
イル９により励磁を行うことにより、磁界中で圧縮成形
を行い、ラジアル異方性配向をもつリング状成形体を得
る。なお、圧縮成形の際には、必要に応じて下部パンチ
４の上昇を行ってもよい。成形体の相対密度は、通常、
５０〜６０％程度である。Then, as shown in FIG. 1D, the upper core rod 7 and the upper punch 3 are lowered, and after the upper core rod 7 contacts the lower core rod 6, the upper punch 3 is further lowered and the lower coil 8 is placed. And by exciting with the upper coil 9, compression molding is performed in a magnetic field to obtain a ring-shaped molded body having a radial anisotropic orientation. It should be noted that the lower punch 4 may be raised as necessary during compression molding. The relative density of the molded body is usually
It is about 50 to 60%.
【００１９】磁石粉末充填時の下部コアロッド６上部の
表面磁束密度は特に限定されず、目的とする高さの磁石
を得るために必要な磁石粉末が充填できるように適宜決
定すればよい。ただし、表面磁束密度が小さすぎる場
合、磁石粉末の下部コアロッドへの磁着が不十分となる
ため、成形空間の径方向幅が小さい場合には成形空間内
への磁石粉末の引き込みがほとんどできなくなる。この
ため、下部コアロッド６上部、特にその側周面｛図１
（ａ）の位置Ａ｝の表面磁束密度は、一般に１００G以
上、好ましくは３００ G以上とする。なお、表面磁束密
度の上限は特にないが、一般に１０００ G程度以下にな
る。The surface magnetic flux density of the upper portion of the lower core rod 6 at the time of filling the magnet powder is not particularly limited, and may be appropriately determined so that the magnet powder required to obtain a magnet of a desired height can be filled. However, if the surface magnetic flux density is too small, the magnetic powder will not be sufficiently magnetically adhered to the lower core rod, and if the radial width of the molding space is small, it will be almost impossible to draw the magnet powder into the molding space. . For this reason, the upper part of the lower core rod 6, especially its peripheral surface {see FIG.
The surface magnetic flux density at position A} in (a) is generally 100 G or more, and preferably 300 G or more. The upper limit of the surface magnetic flux density is not particularly limited, but it is generally about 1000 G or less.
【００２０】一般に、表面磁束密度が小さければ充填効
率が低くなり、成形空間の単位深さあたりの充填量は少
なくなる。一方、表面磁束密度が大きければ充填効率が
高くなり、成形空間の単位深さあたりの充填量は多くな
る。本発明では、いずれの場合でも均一な充填が可能で
あり、成形空間の単位深さあたりの充填量が少なくなる
場合には、成形空間の深さをあらかじめ大きくし、かつ
成形の際の圧縮率を高くするように構成すれば、所定密
度で所定高さのリング状成形体を得ることができる。し
かし、前述したように、成形空間の深さ（充填深さ）を
大きくすると、型枠の有効長を長くする必要があるの
で、型枠表面での配向磁界の磁束密度が減少してしま
い、高特性の異方性磁石が得られなくなるおそれがあ
る。このため、充填効率は、ある程度以上高いことが好
ましい。充填効率の好ましい範囲については、実施例の
欄において詳述する。Generally, if the surface magnetic flux density is small, the filling efficiency is low, and the filling amount per unit depth of the molding space is small. On the other hand, if the surface magnetic flux density is large, the filling efficiency is high, and the filling amount per unit depth of the molding space is large. In the present invention, uniform filling is possible in any case, and when the filling amount per unit depth of the molding space is small, the depth of the molding space is increased in advance, and the compression ratio at the time of molding is If it is configured to be higher, a ring-shaped molded body having a predetermined density and a predetermined height can be obtained. However, as described above, if the depth of the molding space (filling depth) is increased, it is necessary to increase the effective length of the mold, so the magnetic flux density of the orientation magnetic field on the mold surface decreases, An anisotropic magnet with high characteristics may not be obtained. Therefore, it is preferable that the filling efficiency is higher than a certain level. The preferable range of the packing efficiency will be described in detail in the section of Examples.
【００２１】前述したように、成形空間の径方向幅が小
さくなると磁石粉末の充填量が少なくなってしまうが、
本発明では、下部コアロッド上部の表面磁束密度を高く
したり、下部コアロッドの突き出し量を大きくしたりす
ることにより充填効率を高めることができ、これにより
充填量の減少を抑えることが可能である。すなわち、本
発明では、充填深さを大きくする必要がない。これに対
し、前記した特開平１−１４７８１９号公報の方法で
は、径方向幅の小さな成形空間への充填に際して充填量
の減少を抑えるためには、充填深さを大きくせざるを得
ないので、磁界配向の際に上述した問題が生じてしま
う。As described above, when the radial width of the molding space becomes smaller, the filling amount of the magnet powder becomes smaller.
In the present invention, the filling efficiency can be increased by increasing the surface magnetic flux density of the upper portion of the lower core rod or by increasing the protruding amount of the lower core rod, and thus it is possible to suppress the decrease in the filling amount. That is, in the present invention, it is not necessary to increase the filling depth. On the other hand, in the method disclosed in Japanese Patent Laid-Open No. 1-147819, the filling depth must be increased in order to suppress the decrease in the filling amount when filling the molding space having a small radial width. The above-mentioned problems occur during magnetic field orientation.
【００２２】本発明で用いる成形装置において、型枠、
パンチ、コアロッド等の各部の材質は、従来と同様であ
ってよく特に限定されない。In the molding apparatus used in the present invention, the mold,
The material of each part such as the punch and the core rod may be the same as the conventional one and is not particularly limited.
【００２３】本発明では、図１に示す構成の成形装置に
限らず、例えば図２に示す構成の成形装置を使うことも
できる。図２に示す構成の成形装置は、上部コアロッド
を兼ねる円柱状の上部パンチ３を有する。この上部パン
チ３は、図１における上部コアロッドに相当する磁性コ
ア部３１と、この磁性コア部の下部を取り囲み、図１に
おける上部パンチに相当する非磁性部リング部３２とか
ら構成される。この成形装置では、型枠２および上部パ
ンチ３に対し下部パンチ４を相対的に上昇させることに
より圧縮成形を行う。また、この他の構成の成形装置で
あっても、磁石粉末をコアロッドに磁着させて成形空間
内に磁石粉末を引き込むことが可能な構成であれば、い
ずれも本発明を適用することができる。The present invention is not limited to the molding apparatus having the structure shown in FIG. 1, but a molding apparatus having the structure shown in FIG. 2 may be used. The molding apparatus configured as shown in FIG. 2 has a cylindrical upper punch 3 which also serves as an upper core rod. The upper punch 3 includes a magnetic core portion 31 corresponding to the upper core rod in FIG. 1 and a non-magnetic portion ring portion 32 surrounding the lower portion of the magnetic core portion and corresponding to the upper punch in FIG. In this molding apparatus, compression molding is performed by raising the lower punch 4 relative to the mold 2 and the upper punch 3. Further, the present invention can be applied to any molding apparatus having any other structure as long as the magnet powder is magnetically attached to the core rod and the magnet powder can be drawn into the molding space. .
【００２４】また、図示例では箱状のフィーダを用いて
いるが、本発明では下部コアロッド６の上部近傍に磁石
粉末が存在していればよいので、フィーダの形状および
フィーダ使用の有無は特に問わない。また、磁石粉末充
填後の摺り切りについても、摺り切り用の部材を別に設
けて行ってもよい。Further, although a box-shaped feeder is used in the illustrated example, in the present invention, since the magnet powder may be present near the upper portion of the lower core rod 6, the shape of the feeder and the presence / absence of use of the feeder are not particularly limited. Absent. Further, the scraping after filling the magnet powder may be performed by separately providing a scraping member.
【００２５】本発明は、成形空間への磁石粉末の充填が
比較的困難となる乾式成形法を用いるときに特に有効で
あるが、湿式成形の場合にも有効である。The present invention is particularly effective when using a dry molding method, which makes it relatively difficult to fill the molding space with magnet powder, but is also effective when wet molding.
【００２６】上記のようにして得られたリング状成形体
は、焼結されて磁石化される。The ring-shaped molded body obtained as described above is sintered and magnetized.
【００２７】本発明が適用される磁石粉末の組成は特に
限定されず、希土類磁石粉末や酸化物磁石粉末などの種
々のものを用いることができるが、流動性の悪い磁石粉
末を用い、かつ乾式成形を行う場合に、本発明は著しい
効果を発揮する。The composition of the magnet powder to which the present invention is applied is not particularly limited, and various materials such as rare earth magnet powder and oxide magnet powder can be used. The present invention exerts a remarkable effect when molding is performed.
【００２８】流動性の悪い磁石粉末としては、希土類磁
石粉末、特に、Ｒ−Ｔ−Ｂ（ＲはＹを含む希土類元素の
少なくとも１種、ＴはＦｅ、またはＦｅおよびＣｏであ
る）系磁石粉末が挙げられる。As the magnet powder having poor fluidity, rare earth magnet powder, particularly R-T-B (R is at least one rare earth element including Y, T is Fe, or Fe and Co) magnet powder is used. Is mentioned.
【００２９】Ｒ−Ｔ−Ｂ系の磁石粉末は、通常、Ｒを２
７〜３８重量％、Ｔを５１〜７２重量％、Ｂを０．５〜
４．５重量％含有することが好ましい。Ｒ含有量が少な
すぎると鉄に富む相が析出して高保磁力が得られなくな
り、Ｒ含有量が多すぎると高残留磁束密度が得られなく
なる。Ｂ含有量が少なすぎると高保磁力が得られなくな
り、Ｂ含有量が多すぎると高残留磁束密度が得られなく
なる。なお、Ｔ中のＣｏ量は３０重量％以下とすること
が好ましい。さらに、保磁力を改善するために、Ａｌ、
Ｃｒ、Ｍｎ、Ｍｇ、Ｓｉ、Ｃｕ、Ｃ、Ｎｂ、Ｓｎ、Ｗ、
Ｖ、Ｚｒ、Ｔｉ、Ｍｏなどの元素を添加してもよいが、
添加量が６重量％を超えると残留磁束密度が低下してく
る。In the R-T-B type magnet powder, R is usually 2
7-38 wt%, T 51-72 wt%, B 0.5-
It is preferable to contain 4.5% by weight. If the R content is too low, a phase rich in iron precipitates and high coercive force cannot be obtained, and if the R content is too high, high residual magnetic flux density cannot be obtained. If the B content is too small, a high coercive force cannot be obtained, and if the B content is too large, a high residual magnetic flux density cannot be obtained. The amount of Co in T is preferably 30% by weight or less. Further, in order to improve the coercive force, Al,
Cr, Mn, Mg, Si, Cu, C, Nb, Sn, W,
Elements such as V, Zr, Ti and Mo may be added,
If the added amount exceeds 6% by weight, the residual magnetic flux density will decrease.
【００３０】磁石粉末中には、これらの元素の他、不可
避的不純物あるいは微量添加物として、例えば炭素や酸
素が含有されていてもよい。In addition to these elements, the magnet powder may contain carbon and oxygen as unavoidable impurities or trace additives.
【００３１】このような組成を有する磁石粉末は、実質
的に正方晶系の結晶構造の主相を有する。そして、通
常、体積比で０．５〜１０％程度の非磁性相を含むもの
である。The magnet powder having such a composition has a main phase having a substantially tetragonal crystal structure. It usually contains a non-magnetic phase in a volume ratio of about 0.5 to 10%.
【００３２】磁石粉末の製造方法は特に限定されない
が、通常、母合金インゴットを鋳造し、これを粉砕して
製造するか、還元拡散法によって得られた合金粉末を粉
砕して製造する。磁石粉末の平均粒子径は、通常、１〜
１０μm 程度である。The method for producing the magnet powder is not particularly limited, but it is usually produced by casting a mother alloy ingot and crushing it, or by crushing the alloy powder obtained by the reduction diffusion method. The average particle size of the magnet powder is usually 1 to
It is about 10 μm.
【００３３】また、本発明は、ＳｒフェライトやＢａフ
ェライト等のマグネトプランバイト型の酸化物磁石粉末
に対しても適用できる。The present invention can also be applied to magnetoplumbite type oxide magnet powder such as Sr ferrite and Ba ferrite.
【００３４】[0034]
＜実施例１＞組成が３０Ｎｄ−３Ｄｙ−１Ｂ−ｂａｌ．
Ｆｅ（重量％）である合金インゴットを、鋳造により作
製した。この合金インゴットをジョークラッシャおよび
ブラウンミルにより−＃３２にまで粗粉砕し、次いで、
ジェットミルにより微粉砕し、平均粒子径４μm の磁石
粉末を得た。<Example 1> The composition was 30 Nd-3Dy-1B-bal.
An alloy ingot of Fe (wt%) was made by casting. The alloy ingot was crushed to-# 32 with a jaw crusher and a brown mill, then
The powder was finely pulverized with a jet mill to obtain a magnet powder having an average particle diameter of 4 μm.
【００３５】この磁石粉末を、図１に示す構成の成形装
置の成形空間内に充填した。成形空間は、径方向幅１．
７mm（外径１９．５mm、内径１６．１mm）、充填深さ１
３mmであり、目標充填重量は２．５g であった。This magnet powder was filled in the molding space of the molding apparatus having the structure shown in FIG. The molding space has a radial width of 1.
7 mm (outer diameter 19.5 mm, inner diameter 16.1 mm), filling depth 1
It was 3 mm and the target fill weight was 2.5 g.
【００３６】なお、この場合の目標充填重量とは、充填
密度（磁石粉末の充填重量を成形空間の容積で除した
値）が２g/cm3 となるときの充填重量である。Ｒ−Ｔ−
Ｂ系磁石粉末では、充填密度が２g/cm3 を超えると磁界
配向の際に磁石粉末が動きにくくなるので、好ましくな
い。一方、充填密度が低い、すなわち充填効率が低い
と、所定高さのリング状成形体を得るためには充填深さ
を大きくしなければならず、この場合、前述したように
十分な配向磁界が得られなくなり、好ましくない。した
がって、充填密度は２g/cm3 にできるだけ近いことが好
ましい。そこで、本明細書ではＲ−Ｔ−Ｂ系磁石粉末の
充填効率の評価方法として、目標とする充填密度（２g/
cm3 ）に対する実際の充填密度の比率を用いる。そし
て、リング状成形空間では断面積が一定であることか
ら、充填深さを一定とした場合には充填密度は充填重量
に比例するので、本実施例では、上記目標充填重量に対
する実際の充填重量の比率を、充填効率の指標として用
いる。この比率は、６０％以上であることが好ましく、
８０％以上であることがより好ましい。この比率が６０
％を下回る場合、実用的ではない。The target filling weight in this case is the filling weight when the filling density (the value obtained by dividing the filling weight of the magnet powder by the volume of the molding space) is 2 g / cm 3 . R-T-
When the packing density of the B-based magnet powder exceeds 2 g / cm 3 , the magnet powder becomes difficult to move during magnetic field orientation, which is not preferable. On the other hand, if the packing density is low, that is, the packing efficiency is low, the packing depth must be increased in order to obtain a ring-shaped molded body of a predetermined height, and in this case, a sufficient orientation magnetic field is generated as described above. It is not preferable because it cannot be obtained. Therefore, the packing density is preferably as close as possible to 2 g / cm 3 . Therefore, in this specification, as a method for evaluating the packing efficiency of the RTB-based magnet powder, the target packing density (2 g /
The ratio of the actual packing density to cm 3 ) is used. Since the ring-shaped molding space has a constant cross-sectional area, when the filling depth is constant, the filling density is proportional to the filling weight. Therefore, in this embodiment, the actual filling weight with respect to the target filling weight is set. Is used as an index of filling efficiency. This ratio is preferably 60% or more,
It is more preferably 80% or more. This ratio is 60
If it is less than%, it is not practical.
【００３７】上記成形空間への磁石粉末の充填は、図１
の（ａ）〜（ｄ）に示される手順で、以下のようにして
行った。まず、フィーダ１０を成形空間の直上に置き、
下部コアロッド６を上昇させてフィーダ内に突き出し
た。このとき、型枠２上面から下部コアロッド６上面ま
での距離は、成形空間の深さと同じ１３mmとした。この
状態で下部コイル８に３７５Ａの励磁電流を流して下部
コアロッド６を励磁し、磁石粉末５を磁着した。下部コ
アロッド６の表面磁束密度は、図１（ａ）の位置Ａで８
００ G、位置Ｂで２００ G、位置Ｃで１００ Gであっ
た。次いで、励磁されている下部コアロッド６を図１
（ｂ）に示されるように下降させ、磁石粉末５を成形空
間内に引き込んだ。次いで、フィーダ１０を成形空間の
上から移動させると共にフィーダ１０の端部で摺り切り
を行い、図１（ｃ）に示される状態とした。成形空間内
への磁石粉末充填重量は２．３g であり、目標充填重量
の９２％であった。そして、圧縮成形前の成形空間中で
は、図４（ａ）に示されるような磁石粉末の偏りは見ら
れず、均一に充填されていた。The filling of the magnet powder into the molding space is performed as shown in FIG.
The procedure shown in (a) to (d) was performed as follows. First, place the feeder 10 directly above the molding space,
The lower core rod 6 was lifted and projected into the feeder. At this time, the distance from the upper surface of the mold 2 to the upper surface of the lower core rod 6 was 13 mm, which was the same as the depth of the molding space. In this state, an exciting current of 375 A was passed through the lower coil 8 to excite the lower core rod 6, and the magnet powder 5 was magnetically attached. The surface magnetic flux density of the lower core rod 6 is 8 at the position A in FIG.
00 G, 200 B at position B, and 100 G at position C. Next, the magnetized lower core rod 6 is shown in FIG.
As shown in (b), the magnet powder 5 was lowered and drawn into the molding space. Next, the feeder 10 was moved from above the molding space, and the end portion of the feeder 10 was scraped off to obtain the state shown in FIG. The filling weight of the magnet powder in the molding space was 2.3 g, which was 92% of the target filling weight. In the molding space before compression molding, no bias of the magnet powder as shown in FIG. 4A was observed, and the magnet powder was uniformly filled.
【００３８】次いで、図１（ｄ）に示されるように、磁
界中で圧縮成形を行い、ラジアル異方性配向をもつリン
グ状成形体を得た。励磁電流は、下部コイルおよび上部
コイル共に３７５Ａとし、成形圧力は１．５t/cm2 とし
た。得られた成形体には、図４（ｂ）に示されるような
クラックの発生は認められなかった。Then, as shown in FIG. 1 (d), compression molding was performed in a magnetic field to obtain a ring-shaped molded product having a radial anisotropic orientation. The exciting current was 375 A for both the lower coil and the upper coil, and the molding pressure was 1.5 t / cm 2 . No cracks as shown in FIG. 4B were observed in the obtained molded product.
【００３９】＜比較例１＞実施例１の成形装置および磁
石粉末を用い、下部コアロッド６の突き出しを行わず、
フィーダ１０を型枠２上で１０回往復運動することによ
り摺り切り充填を行った。このときの成形空間内への磁
石粉末の充填重量は０．７g であり、目標充填重量の２
８％であった。そして、圧縮成形前の成形空間中では、
図４（ａ）に示されるような磁石粉末の偏りが生じてい
た。Comparative Example 1 Using the molding apparatus and magnet powder of Example 1, the lower core rod 6 was not ejected,
The feeder 10 was reciprocated 10 times on the mold 2 to perform scraping and filling. The filling weight of the magnet powder in the molding space at this time is 0.7 g, which is 2% of the target filling weight.
8%. And in the molding space before compression molding,
The bias of the magnet powder was generated as shown in FIG.
【００４０】この状態で実施例１と同様にして磁界中成
形を行ったところ、得られた成形体には図４（ｂ）に示
されるようなクラックの発生が認められた。When molding was performed in this state in the same manner as in Example 1 in a magnetic field, the obtained molded product was found to have cracks as shown in FIG. 4 (b).
【００４１】＜比較例２＞特開平１−１４７８１９号公
報で提案されている方法にしたがい、実施例１の成形装
置および磁石粉末を用いて以下の手順で磁石粉末の充填
を行った。まず、下部コアロッド６を、その上面が下部
パンチ３の上面と同一平面上に存在するように下降させ
て円柱状の充填空間を形成し、フィーダ１０を型枠２上
で１０回往復運動することにより、前記充填空間内に摺
り切り充填を行った。次いで、フィーダ１０を停止さ
せ、下部コアロッド６を図１（ｂ）の状態となるように
上昇させた。このときの成形空間内への磁石粉末の充填
重量は１．１g であり、目標充填重量の４４％にすぎな
かった。<Comparative Example 2> According to the method proposed in Japanese Patent Laid-Open No. 1-147819, the magnet powder was filled in the following procedure using the molding apparatus and magnet powder of Example 1. First, the lower core rod 6 is lowered so that the upper surface thereof is flush with the upper surface of the lower punch 3 to form a cylindrical filling space, and the feeder 10 is reciprocated 10 times on the mold 2. Thus, the filling space was slid and filled. Next, the feeder 10 was stopped, and the lower core rod 6 was raised so as to be in the state of FIG. 1 (b). The filling weight of the magnet powder in the molding space at this time was 1.1 g, which was only 44% of the target filling weight.
【００４２】＜実施例２＞径方向幅１．２mm（外径１
２．５mm、内径１０．１mm）、充填深さ１０mmであり、
目標充填重量が０．８５g である成形空間を有する成形
装置を用い、図１の（ａ）の状態における下部コアロッ
ド６の突き出し量を１５mmとし、下部コイル８の励磁電
流を４００Ａとした以外は実施例１と同様にして、磁石
粉末の充填を行った。下部コアロッド６の表面磁束密度
は、図１（ａ）の位置Ａで５８０ G、位置Ｂで６００
G、位置Ｃで７２０ Gであった。なお、励磁電流を１０
０Ａと小さくしたときの表面磁束密度は、位置Ａで４５
０ G、位置Ｂで３００ G、位置Ｃで２００ Gであった。
励磁電流が４００Ａのときの成形空間内への磁石粉末の
充填重量は０．７７g であり、目標充填重量の９１％で
あった。また、励磁電流を１００Ａとしたときの成形空
間内への磁石粉末の充填重量は０．５７g であり、この
ように表面磁束密度が小さい場合でも目標充填重量の６
７％の充填量が得られた。圧縮成形前の成形空間中で
は、図４（ａ）に示されるような磁石粉末の偏りは見ら
れず、均一に充填されていた。<Example 2> 1.2 mm width in radial direction (outer diameter 1
2.5 mm, inner diameter 10.1 mm), filling depth 10 mm,
Using a molding apparatus having a molding space whose target filling weight is 0.85 g, except that the protrusion amount of the lower core rod 6 in the state of FIG. 1 (a) is 15 mm and the exciting current of the lower coil 8 is 400 A. The magnetic powder was filled in the same manner as in Example 1. The surface magnetic flux density of the lower core rod 6 is 580 G at position A and 600 at position B in FIG.
It was 720 G at G and position C. The exciting current is 10
The surface magnetic flux density when reduced to 0 A is 45 at position A.
0 G, 300 G at position B and 200 G at position C.
The filling weight of the magnet powder in the molding space when the exciting current was 400 A was 0.77 g, which was 91% of the target filling weight. The filling weight of the magnet powder in the molding space when the exciting current was 100 A was 0.57 g, which was 6% of the target filling weight even when the surface magnetic flux density was small.
A loading of 7% was obtained. In the molding space before compression molding, no bias of the magnet powder as shown in FIG. 4 (a) was observed, and the magnet powder was uniformly filled.
【００４３】充填の際の励磁電流を４００Ａとした磁石
粉末に対し、配向磁界用の励磁電流を４００Ａとした他
は実施例１と同様にして圧縮成形を行った。得られた成
形体には、図４（ｂ）に示されるようなクラックの発生
は認められなかった。Compression molding was carried out in the same manner as in Example 1 except that the exciting current for the orientation magnetic field was set to 400 A with respect to the magnet powder whose exciting current at the time of filling was set to 400 A. No cracks as shown in FIG. 4B were observed in the obtained molded product.
【００４４】この成形体を、真空中で１１００℃にて２
時間焼結した後、急冷し、次いで、Ａｒ雰囲気中で６０
０℃にて１時間時効処理を行ない、リング磁石を得た。
このリング磁石の外周を研削して平滑化した後、径方向
が切断面となるように均等に８分割し、各々の分割片に
ついて振動試料型磁力計（ＶＳＭ）により残留磁束密度
Ｂｒ、保磁力Ｈcj、最大エネルギー積(BH)max を測定し
た。結果を表１に示す。This molded body was vacuum-treated at 1100 ° C. for 2 hours.
After being sintered for 60 hours, quenched, and then in an Ar atmosphere at 60
Aging treatment was performed at 0 ° C. for 1 hour to obtain a ring magnet.
The outer circumference of this ring magnet was ground and smoothed, and then the ring magnet was evenly divided into 8 parts so that the cut surface was in the radial direction. Hcj and maximum energy product (BH) max were measured. The results are shown in Table 1.
【００４５】[0045]
【表１】 [Table 1]
【００４６】＜比較例３＞実施例２の成形装置および磁
石粉末を用い、下部コアロッド６の突き出しを行わず、
フィーダ１０を型枠２上で１０回往復運動することによ
り摺り切り充填を行った。このときの成形空間内への磁
石粉末の充填重量は０．３５g であり、目標充填重量の
４３％であった。そして、圧縮成形前の成形空間中で
は、図４（ａ）に示されるような磁石粉末の偏りが生じ
ていた。<Comparative Example 3> Using the molding apparatus and magnet powder of Example 2, the lower core rod 6 was not ejected,
The feeder 10 was reciprocated 10 times on the mold 2 to perform scraping and filling. The filling weight of the magnet powder in the molding space at this time was 0.35 g, which was 43% of the target filling weight. Then, in the molding space before the compression molding, the bias of the magnet powder as shown in FIG.
【００４７】この状態で、成形圧力を４．０t/cm2 とし
た以外は実施例２と同様にして磁界中成形を行ったとこ
ろ、得られた成形体には図４（ｂ）に示されるようなク
ラックの発生が認められた。なお、成形圧力を実施例２
よりも高くしたのは、クラックに起因する焼結前や焼結
時の破壊を防ぐためである。In this state, molding was carried out in a magnetic field in the same manner as in Example 2 except that the molding pressure was 4.0 t / cm 2, and the obtained molded body is shown in FIG. 4 (b). The occurrence of such cracks was recognized. The molding pressure was set to the value in Example 2.
The reason why the temperature is higher than that is to prevent damage before and during sintering due to cracks.
【００４８】クラックの存在する成形体を、実施例２と
同様な条件で焼結して時効処理し、リング磁石を得た。
このリング磁石を、外周研削をせずに図３に示されるよ
うに径方向に均等に８分割し、実施例２と同様にして磁
気特性を測定した。結果を表２に示す。なお、外周研削
をしなかったのは、クラックに起因する破壊を防ぐため
である。The compact having cracks was sintered and aged under the same conditions as in Example 2 to obtain a ring magnet.
This ring magnet was evenly divided into eight parts in the radial direction as shown in FIG. 3 without grinding the outer periphery, and the magnetic characteristics were measured in the same manner as in Example 2. Table 2 shows the results. The outer circumference was not grounded in order to prevent damage due to cracks.
【００４９】[0049]
【表２】 [Table 2]
【００５０】表１と表２との比較から、本発明の効果が
明らかである。本発明を適用して製造された表１の磁石
では、分割片間で磁気特性のばらつきほとんど認められ
ない。これに対し、摺り切り充填を用いて製造された表
２の磁石では、磁気特性に大きなばらつきが生じてい
る。表２の磁石では、磁石粉末の充填時に図４（ａ）に
示されるような偏りが生じたので、図３の（１）および
（５）に相当する領域での成形体密度が高くなってしま
い、この結果、これらの領域での磁石粉末の磁界配向が
不十分となってＢｒが低くなったと考えられる。From the comparison between Table 1 and Table 2, the effect of the present invention is clear. In the magnet of Table 1 manufactured by applying the present invention, there is almost no variation in magnetic characteristics between the divided pieces. On the other hand, in the magnets of Table 2 manufactured by using the scraping filling, there is a large variation in the magnetic characteristics. In the magnets of Table 2, the bias as shown in FIG. 4 (a) occurred when the magnet powder was filled, so that the compact density in the regions corresponding to (1) and (5) in FIG. 3 increased. It is considered that, as a result, the magnetic field orientation of the magnet powder in these regions was insufficient and Br became low.
【図面の簡単な説明】[Brief description of drawings]
【図１】（ａ）〜（ｄ）は、本発明における成形装置各
部と磁石粉末との動きの例を示す端面図である。1 (a) to 1 (d) are end views showing an example of the movement of each part of a molding apparatus and magnet powder in the present invention.
【図２】本発明で用いる成形装置の構成例を示す端面図
である。FIG. 2 is an end view showing a configuration example of a molding apparatus used in the present invention.
【図３】比較例３において磁気特性のばらつきを調べる
ためにリング磁石を分割したときの切断方向を示す平面
図である。FIG. 3 is a plan view showing a cutting direction when a ring magnet is divided in order to examine variations in magnetic characteristics in Comparative Example 3.
【図４】（ａ）は、従来の磁石粉末充填方法におけるフ
ィーダ移動方向と磁石粉末充填量との関係を示す斜視図
であり、（ｂ）は、従来の磁石粉末充填方法を用いたと
きにリング状成形体に発生するクラックの例を示す斜視
図である。FIG. 4 (a) is a perspective view showing a relationship between a feeder moving direction and a magnet powder filling amount in a conventional magnet powder filling method, and FIG. 4 (b) shows a case where the conventional magnet powder filling method is used. It is a perspective view which shows the example of the crack which a ring-shaped molded object generate | occur | produces.
２ 型枠 ３ 上部パンチ ３１ 磁性コア部 ３２ 非磁性リング部 ４ 下部パンチ ５ 磁石粉末 ６ 下部コアロッド ７ 上部コアロッド ８ 下部コイル ９ 上部コイル １０ フィーダ 2 Formwork 3 Upper Punch 31 Magnetic Core Part 32 Non-Magnetic Ring Part 4 Lower Punch 5 Magnet Powder 6 Lower Core Rod 7 Upper Core Rod 8 Lower Coil 9 Upper Coil 10 Feeder
Claims (6)
形工程において、 型枠内にリング状の成形空間を介して円柱状のコアロッ
ドが設けられている成形装置の成形空間へ磁石粉末を充
填するに際し、磁化されたコアロッドの上部が型枠上面
から突出し、かつコアロッドに磁石粉末が磁着している
状態とした後、型枠に対し相対的にコアロッドを下降さ
せることにより、磁石粉末を成形空間内に引き込んで充
填を行う磁石粉末の成形方法。1. A magnet powder is filled into a molding space of a molding machine in which a cylindrical core rod is provided in a mold via a ring-shaped molding space in a molding step in manufacturing a radial anisotropic ring magnet. At this time, after the magnetized core rod has an upper part protruding from the upper surface of the mold and magnet powder is magnetically attached to the core rod, the core rod is lowered relative to the mold to form the magnet powder. A method for molding magnet powder in which the powder is drawn into the space for filling.
ら突出している高さの最大値が、成形空間への磁石粉末
の充填深さ以上である請求項１の磁石粉末の成形方法。2. The method for molding magnet powder according to claim 1, wherein the maximum value of the height of the magnetized core rod protruding from the upper surface of the mold is not less than the filling depth of the magnet powder in the molding space.
求項１または２の磁石粉末の成形方法。3. The method for molding magnet powder according to claim 1, wherein the radial width of the molding space is 5 mm or less.
末を充填し、このフィーダを成形空間の上で停止させ、
このフィーダ内にコアロッドを突き出して磁石粉末を磁
着させる請求項１〜３のいずれかの磁石粉末の成形方
法。4. A box-shaped feeder having no bottom is filled with magnet powder, and the feeder is stopped on the molding space,
The method of molding magnet powder according to any one of claims 1 to 3, wherein the core rod is projected into the feeder to magnetize the magnet powder.
界を印加して、ラジアル配向の成形体を得る請求項１〜
４のいずれかの磁石粉末の成形方法。5. A radially oriented molded body is obtained by applying a magnetic field in the radial direction of the molding space after filling the magnet powder.
4. The method for forming a magnetic powder according to any one of 4 above.
少なくとも１種、ＴはＦｅ、またはＦｅおよびＣｏであ
る）系磁石粉末の成形に適用される請求項１〜５のいず
れかの磁石粉末の成形方法。6. The method according to claim 1, wherein the method is applied to the molding of R-T-B (R is at least one rare earth element containing Y, T is Fe, or Fe and Co) magnet powder. The method of molding the magnet powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13084796A JP4057075B2 (en) | 1996-04-26 | 1996-04-26 | Molding method of magnet powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13084796A JP4057075B2 (en) | 1996-04-26 | 1996-04-26 | Molding method of magnet powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09293623A true JPH09293623A (en) | 1997-11-11 |
| JP4057075B2 JP4057075B2 (en) | 2008-03-05 |
Family
ID=15044090
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13084796A Expired - Fee Related JP4057075B2 (en) | 1996-04-26 | 1996-04-26 | Molding method of magnet powder |
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| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001093765A (en) * | 1999-09-24 | 2001-04-06 | Hitachi Metals Ltd | Method for manufacturing rear-earth permanent magnet |
-
1996
- 1996-04-26 JP JP13084796A patent/JP4057075B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001093765A (en) * | 1999-09-24 | 2001-04-06 | Hitachi Metals Ltd | Method for manufacturing rear-earth permanent magnet |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4057075B2 (en) | 2008-03-05 |
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