JPH0711013B2 - Permanent magnet powder filling method and filling device - Google Patents
Permanent magnet powder filling method and filling deviceInfo
- Publication number
- JPH0711013B2 JPH0711013B2 JP10405689A JP10405689A JPH0711013B2 JP H0711013 B2 JPH0711013 B2 JP H0711013B2 JP 10405689 A JP10405689 A JP 10405689A JP 10405689 A JP10405689 A JP 10405689A JP H0711013 B2 JPH0711013 B2 JP H0711013B2
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- molding space
- powder
- magnet powder
- filling
- 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.)
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- Powder Metallurgy (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、金型の円筒状成形空間の開口近傍にソレノイ
ドコイルと磁性ポールを設置し、交流磁場を印加するこ
とによって永久磁石粉体を短時間で均一に成形空間内に
充填する技術に関するものである。磁性ポールは円錐台
状をなし、その上面直径が下面直径の1/6以上であり且
つ下面直径か円筒状成形空間を形成する金型の下ロッド
の直径と同一もしくはそれよりやや小さい。DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention provides a permanent magnet powder by placing a solenoid coil and a magnetic pole near the opening of a cylindrical molding space of a mold and applying an alternating magnetic field. The present invention relates to a technique for uniformly filling a molding space in a short time. The magnetic pole is frustoconical in shape, and the diameter of the upper surface is 1/6 or more of the diameter of the lower surface and is equal to or slightly smaller than the diameter of the lower surface or the lower rod of the mold forming the cylindrical molding space.
この技術は希土類磁石やフェライト磁石、金属磁石等の
成形、あるいはそれらを使用したボンド磁石の製造など
に利用できる。This technique can be used for forming rare earth magnets, ferrite magnets, metal magnets, etc., or for manufacturing bonded magnets using them.
［従来の技術］ 永久磁石粉体の成形には、良好な磁気特性を発現させる
ため、通常、金型の成形空間内に永久磁石粉体を充填し
プレス成形機で圧縮成形する方法が採用されている。[Prior Art] In order to exhibit good magnetic properties, permanent magnet powder is usually filled in the molding space of a mold and compression-molded by a press molding machine in order to express good magnetic properties. ing.
圧縮成形において、金型成形空間内への永久磁石粉体の
充填は専ら重力による自然落下を利用して行われる。つ
まり金型を構成するダイスの上面をスライドする無底の
粉体供給機構によって粉体を成形空間の開口部から自然
落下させて充填し、粉体供給機構をスライドさせて余分
な粉体を取り除く摺切り方式で一定量の粉体を金型の成
形空間内に充填する方法が一般的である。In compression molding, the filling of the permanent magnet powder into the mold molding space is performed exclusively by gravity falling by gravity. In other words, a bottomless powder supply mechanism that slides on the upper surface of the die that forms the mold allows the powder to drop naturally from the opening of the molding space to fill it, and slide the powder supply mechanism to remove excess powder. A method of filling a certain amount of powder into the molding space of a mold by a sliding method is generally used.
金型成形空間の開口面積がかなり大きいものについては
このような方法によって充填可能であるが、例えば薄肉
円筒状のように開口部の幅が小さい場合には、単に粉体
供給機構を金型上面に沿ってスライドさせるだけでは充
分な充填は困難である。If the opening area of the mold forming space is considerably large, it is possible to fill it by such a method. However, if the opening width is small, as in the case of a thin-walled cylinder, for example, simply use the powder supply mechanism as the upper surface of the mold. Sufficient filling is difficult only by sliding along.
そのため金型に振動を加えて充填する方法や成形空間の
上部に強制充填用の羽根（押し込み用部材）を設けて強
制的に粉体を押し込む方法等が採られることもある。Therefore, a method of filling the mold by applying vibration, a method of forcibly pressing the powder by providing a forced filling blade (pressing member) in the upper part of the molding space, and the like may be adopted.
［発明が解決しようとする課題］ 金型に振動を加えて充填する方法は、粉体の状態や形状
によって充填率が変化し易いこと、振動を与えるため装
置のボルト等の締め付けが緩くなる虞れがあること、充
填効率はあまり改善されず、充填量の再現性も悪いこと
等の欠点があった。[Problems to be Solved by the Invention] In a method of filling a mold by applying vibration, the filling rate is likely to change depending on the state and shape of powder, and vibration may be applied, so that tightening of bolts or the like of the device may become loose. However, there were drawbacks such as the fact that the filling efficiency was not improved so much and the reproducibility of the filling amount was poor.
また羽根を用いて強制充填する方法では、充填に要する
時間が非常に長くかかるばかりでなくプレス工程におけ
る粉体充填の自動化が困難で製造効率が極めて悪いこ
と、また羽根によって強制的に押し込まれるため充填さ
れた粉体の形状が以前（充填前）の形状と異なる部分が
局所的に発生し、そのため均一定量充填が困難で成形時
に重量のばらつきや密度分布の不均一が生じる等の欠点
があった。Also, in the method of forced filling using blades, not only the time required for filling is very long, but also the automation of powder filling in the pressing process is difficult and production efficiency is extremely poor, and the blades are forced to fill. The shape of the filled powder is locally different from the shape before (before filling), so it is difficult to perform uniform quantitative filling, and there are drawbacks such as uneven weight distribution and uneven density distribution during molding. It was
本発明の目的は、上記のような従来技術の欠点を解消
し、薄肉円筒状の成形空間内に永久磁石粉体を極く短時
間で均一に一定量充填でき、それによって良好な磁気特
性の永久磁石を製造でき、しかも既存のプレス成形機に
も直ちに適用できるような永久磁石粉体の充填技術を提
供することにある。The object of the present invention is to eliminate the drawbacks of the prior art as described above, and to uniformly and uniformly fill a thin cylindrical molding space with a permanent magnet powder in a very short time, thereby providing good magnetic properties. It is an object of the present invention to provide a permanent magnet powder filling technology that can manufacture permanent magnets and can be immediately applied to existing press molding machines.
［課題を解決するための手段］ 上記のような目的を達成することのできる本発明は、金
型の円筒状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
に設置すると共に、該ソレノイドコイルの中心軸上に、
上面直径が下面直径の1/6以上であり且つ下面直径が円
筒状成形空間を形成する金型の下ロッドの直径と同一も
しくはやや小さい円錐台状の磁性ポールを設け、交流電
流を供給して前記開口上方の永久磁石粉体を前記成形空
間内に磁気的に吸引し充填する永久磁石粉体の充填方法
である。ここで「円筒状」という用語は、軸方向長さが
長い場合のみならず、軸方向長さが短いリング状をも含
む広い意味で用いている。[Means for Solving the Problems] In the present invention capable of achieving the above-mentioned object, a solenoid coil is provided in the vicinity of an opening of a cylindrical molding space of a mold,
The central axis of the solenoid coil is installed in a direction substantially matching the depth direction of the molding space, and on the central axis of the solenoid coil,
A frustoconical magnetic pole with an upper surface diameter that is 1/6 or more of the lower surface diameter and a lower surface diameter that is the same as or slightly smaller than the diameter of the lower rod of the mold that forms the cylindrical molding space is provided to supply alternating current. A permanent magnet powder filling method of magnetically attracting and filling the permanent magnet powder above the opening into the molding space. Here, the term “cylindrical” is used in a broad sense including not only a case where the axial length is long, but also a case where the axial length is short.
この方法を実施するための装置としては、ソレノイドコ
イルと磁性ポールとが非磁性の連結部材で結合一体化さ
れているものがある。As an apparatus for carrying out this method, there is one in which a solenoid coil and a magnetic pole are connected and integrated by a non-magnetic connecting member.
磁性ポールを円錐台状にしたのは永久磁石粉体がスムー
ズに円筒状の成形空間に入るようにするためである。こ
こで上面の直径を下面直径の1/6以上としたのは、1/6未
満では上面付近で磁気飽和し易くなり金型にかかる磁場
が小さくなって粉体を成形空間に吸引する力が弱くなる
からである。また下面の直径を金型の下ロッドの直径と
同一もしくはやや小さくしたのは、小さすぎると磁性ポ
ールが細くなり磁気飽和が生じ易くなるからである。本
来なら下面の直径を金型の下ロッドの直径と同一にする
のが理想であるが、粉体を供給したり成形する際に金型
ダイス上を動かすことから若干小さめが好ましい。The magnetic pole is formed into a truncated cone shape so that the permanent magnet powder can smoothly enter the cylindrical forming space. Here, the diameter of the upper surface is set to be 1/6 or more of the diameter of the lower surface because if it is less than 1/6, magnetic saturation is likely to occur near the upper surface, the magnetic field applied to the mold is reduced, and the force for attracting powder into the molding space is reduced. Because it becomes weak. Further, the diameter of the lower surface is made equal to or slightly smaller than the diameter of the lower rod of the mold, because if it is too small, the magnetic pole becomes thin and magnetic saturation easily occurs. Originally, it is ideal that the diameter of the lower surface be the same as the diameter of the lower rod of the mold, but it is preferable that it is slightly smaller because it moves on the mold die when supplying or molding the powder.
本発明方法では、希土類系、フェライト系、アルニコ
系、或いはネオジウム−鉄−ボロン系等の任意の永久磁
石粉体を使用できるし、また任意の粒径或いは状態の粉
体でも適用可能である。従って焼結磁石用の粉体であっ
てもよいし、樹脂と混練したボンド磁石用の粉体であっ
てもよい。In the method of the present invention, any permanent magnet powder such as rare earth-based, ferrite-based, alnico-based, or neodymium-iron-boron-based powder can be used, and powder with any particle size or state can also be applied. Therefore, it may be powder for a sintered magnet or powder for a bonded magnet kneaded with a resin.
［作用］ 周知のように、或る一定の保磁力をもった永久磁石粉体
は磁場によって敏感に反応する。そしてこれらの永久磁
石粉体は当然のことながら強力な磁場方向へ吸引される
性質を持つ。金型の成形空間の開口近傍に中心軸が成形
空間深さ方向にほぼ一致するような向きでソレノイドコ
イルを設置し交流電流を供給すると、交流磁場が印加さ
れそれによって永久磁石粉体に移動力が与えられる。ソ
レノイドコイルの中央には磁性ポールが設けられている
ため、この磁性ポールによって磁場が集中し、小さな電
流でも永久磁石粉体に十分大きな移動力が付与される。[Operation] As is well known, a permanent magnet powder having a certain coercive force sensitively reacts with a magnetic field. And, of course, these permanent magnet powders have the property of being attracted in the direction of a strong magnetic field. When a solenoid coil is installed near the opening of the molding space of the mold in such a direction that the central axis is substantially aligned with the depth direction of the molding space and an alternating current is supplied, an alternating magnetic field is applied, which causes a movement force to the permanent magnet powder. Is given. Since the magnetic pole is provided at the center of the solenoid coil, the magnetic field concentrates the magnetic pole, and a sufficiently large moving force is applied to the permanent magnet powder even with a small current.
この移動力は永久磁石粉体を成形空間内に吸引させる方
向に働き、永久磁石粉体は前記空間内に順次充填されて
いく。この充填は自然落下等による力よりも遥かに大き
な磁気的吸引力によって行われるため、金型の成形空間
の開口部の幅が極端に狭い場合であっても極く短時間で
スムーズに行われる。しかも従来の羽根等による強制充
填とは異なり、永久磁石粉体は殆ど壊れずにほぼ均一に
充填される。This moving force acts in the direction of attracting the permanent magnet powder into the molding space, and the permanent magnet powder is sequentially filled in the space. Since this filling is performed by a magnetic attraction force that is much larger than the force due to natural fall, etc., it is smoothly performed in an extremely short time even when the width of the opening of the molding space of the mold is extremely narrow. . Moreover, unlike the conventional forced filling with a blade or the like, the permanent magnet powder is filled almost uniformly without being broken.
磁性ポールは上面と下面の直径が所定の比率で且つ下面
が金型の下ロッドに対応した寸法の円錐台状であるた
め、永久磁石粉体は円筒状の成形空間が薄肉構造であっ
てもスムーズに充填される。Since the magnetic pole has a frustoconical shape in which the diameter of the upper surface and the lower surface has a predetermined ratio and the lower surface has a size corresponding to the lower rod of the mold, the permanent magnet powder has a cylindrical molding space even if the molding space has a thin wall structure. Filled smoothly.
［実施例］ 第１図は本発明方法を実施するのに好適な装置の一例を
示す説明図である。これは円筒状の成形体を得るための
金型の一部を示している。中央に円形の穴を有するダイ
ス10と、その中心に間隙をおいて配置される下ロッド12
と、前記ダイス10と下ロッド12との円筒状の間隙内を上
下方向に摺動自在の円筒状下パンチ14とを具備してい
る。それら三者によって形成される円筒状の空隙が成形
空間18になる。その成形空間18内に永久磁石粉体を充填
し、上方から円筒状の上パンチ（図示せず）を挿入加圧
して圧縮成形を行う。このようなプレス成形機金型構造
は基本的には従来の場合と同様である。[Example] FIG. 1 is an explanatory view showing an example of an apparatus suitable for carrying out the method of the present invention. This shows a part of a mold for obtaining a cylindrical molded body. Die 10 with a circular hole in the center and lower rod 12 with a gap in the center
And a cylindrical lower punch 14 which is vertically slidable in a cylindrical gap between the die 10 and the lower rod 12. The cylindrical void formed by these three becomes the molding space 18. The molding space 18 is filled with a permanent magnet powder, and a cylindrical upper punch (not shown) is inserted from above and pressurized to perform compression molding. The mold structure of such a press molding machine is basically the same as the conventional case.
本発明では、金型の成形空間18の開口近傍にソレノイド
コイル20を配置する。このソレノイドコイル20は、その
中心軸方向が成形空間18の深さ方向にほぼ一致する向き
とし、その内径は成形空間18の外径よりもやや大きい。
そして前記ソレノイドコイル20の中心軸に沿って下ロッ
ド12上に純鉄からなる磁性ポール22を設置する。この磁
性ポール22は、下面直径D1が下ロッド12の直径と同一も
しくはやや小さく且つ上面直径D2が下面直径D1の1/6以
上である円錐台状をなしている（即ちD1/6≦D2）。ここ
でソレノイドコイル20と磁性ポール22とは非磁性の連結
部材（図示せず）で結合一体化し、粉体供給時にダイス
10上を一緒にスライドできるようになっている。つまり
永久磁石粉体を金型内に充填する際には成形空間の上方
の所定の位置に移動し、プレス成形時には成形動作（上
パンチの降下）の邪魔にならないように成形空間から外
れた位置に移動する。In the present invention, the solenoid coil 20 is arranged near the opening of the molding space 18 of the mold. The solenoid coil 20 is oriented such that its central axis direction substantially coincides with the depth direction of the molding space 18, and its inner diameter is slightly larger than the outer diameter of the molding space 18.
Then, a magnetic pole 22 made of pure iron is installed on the lower rod 12 along the central axis of the solenoid coil 20. The magnetic pole 22 has a truncated cone shape in which the lower surface diameter D 1 is the same as or slightly smaller than the lower rod 12 and the upper surface diameter D 2 is 1/6 or more of the lower surface diameter D 1 (that is, D 1 / 6 ≦ D 2 ). Here, the solenoid coil 20 and the magnetic pole 22 are connected and integrated by a non-magnetic connecting member (not shown), and the die is used when powder is supplied.
It is designed so that you can slide together on the top 10. That is, when the permanent magnet powder is filled in the mold, it moves to a predetermined position above the molding space, and when it is press-molded, it moves out of the molding space so as not to interfere with the molding operation (lowering of the upper punch). Move to.
なおこの実施例では、金型構成する部材のうちダイス10
と下ロッド12は磁性材で構成し、下パンチ14（上パンチ
も）は非磁性材で構成している。In this embodiment, the die 10 among the members constituting the die is used.
The lower rod 12 and the lower rod 12 are made of a magnetic material, and the lower punch 14 (and the upper punch) are made of a non-magnetic material.
永久磁石粉体の充填は同図に示すようにして行う。金型
の成形空間18の開口近傍に前記のようにソレノイドコイ
ル20及び磁性ポール22を設置し、成形空間18の上方に永
久磁石粉体24を盛る。そしてソレノイドコイル20に交流
電流を供給する。ここで印加する磁場は50e以上、使用
する交流電流の周波数は10kHz以上である。ソレノイド
コイル20に交流電流を流すことによって、同図破線で示
すように磁力線が生じ、永久磁石粉体24及び成形空間18
内等に交流磁場が形成される。磁性ポール22によって成
形空間18に交流磁場を集中させることができ、弱い電流
でも永久磁石粉体24を前記成形空間18内に有効に吸引さ
せることができる。磁力線の形状は便宜的におおよその
経路を表してある。ソレノイドコイル20によって発生し
た磁束は磁性ポール22に集められ、下ロッド12、ダイス
10を通り、ソレノイドコイル20の外側を抜け再び磁性ポ
ール22に戻る。成形空間18の上部に盛った永久磁石粉体
24に交流磁場を加えると、粉体盛り上げ部に大して円筒
状成形空間18の磁束密度の方が大きくなり、その差によ
って粉体が円筒状成形空間18の内部に磁気的に吸引され
る。ダイス10上に残った永久磁石粉体24も前記交流磁場
に反応して複雑な振動を繰り返し非常に狭い間隙であっ
ても短時間（数秒以内）に完全に充填されてしまう。The permanent magnet powder is filled as shown in FIG. The solenoid coil 20 and the magnetic pole 22 are installed near the opening of the molding space 18 of the mold as described above, and the permanent magnet powder 24 is placed above the molding space 18. Then, an alternating current is supplied to the solenoid coil 20. The magnetic field applied here is 50 e or more, and the frequency of the alternating current used is 10 kHz or more. By passing an alternating current through the solenoid coil 20, magnetic force lines are generated as shown by the broken line in the figure, and the permanent magnet powder 24 and the molding space 18 are formed.
An alternating magnetic field is formed inside. An AC magnetic field can be concentrated in the molding space 18 by the magnetic pole 22, and the permanent magnet powder 24 can be effectively attracted into the molding space 18 even with a weak current. The shape of the lines of magnetic force represents an approximate path for convenience. The magnetic flux generated by the solenoid coil 20 is collected by the magnetic pole 22, and the lower rod 12 and the die
It passes through 10, passes through the outside of the solenoid coil 20, and returns to the magnetic pole 22 again. Permanent magnet powder on top of the molding space 18
When an alternating magnetic field is applied to 24, the magnetic flux density of the cylindrical molding space 18 becomes larger than that of the powder raising portion, and the difference magnetically attracts the powder into the cylindrical molding space 18. The permanent magnet powder 24 remaining on the die 10 also reacts with the alternating magnetic field and repeats complicated vibrations, and is completely filled in a short time (within a few seconds) even in a very narrow gap.
従ってその後必要があれば余分な永久磁石粉体を摺切り
法等によって取り除き、上パンチを降下させ加圧して圧
縮成形を行う。Therefore, if necessary, excess permanent magnet powder is removed by a sliding method or the like, and the upper punch is lowered and pressed to perform compression molding.
ソレノイドコイルと磁性ポールとを連結部材で結合一体
化するのが好ましいのは、次の理由による。ソレノイド
コイルと磁性ポールとは、粉体充填時には成形空間上に
位置するように、また成形工程時には成形空間から離れ
るように移動できるようにする必要がある。一体化され
ていれば、一緒に動かすことができるし、両者の位置関
係を常に一定に保つことができる。つまり、ソレノイド
コイル20と磁性ポール22とが、充填−成形の工程でダイ
ス上を水平に移動する場合、両者が一体化されていない
と、特に粉体充填時にソレノイドコイル20と磁性ポール
22の位置関係が変化し易く、位置関係のずれは粉体の充
填のバラツキ、ひいては成形品の成形密度のバラツキに
つながるからである。なお、非磁性の連結部材を用いる
のはソレノイドコイル20と磁性ポール22でつくる磁束分
布（磁力線）を乱さないためである。The reason why the solenoid coil and the magnetic pole are preferably connected and integrated by a connecting member is as follows. It is necessary that the solenoid coil and the magnetic pole be able to move so as to be located in the molding space during powder filling and be separated from the molding space during the molding process. If they are integrated, they can be moved together and the positional relationship between them can be kept constant at all times. In other words, when the solenoid coil 20 and the magnetic pole 22 move horizontally on the die in the filling-molding process, if the two are not integrated, the solenoid coil 20 and the magnetic pole 22 should be packed especially when powder is filled.
This is because the positional relationship of 22 is likely to change, and the deviation of the positional relationship leads to variations in the filling of the powder and eventually variations in the molding density of the molded product. The non-magnetic connecting member is used so as not to disturb the magnetic flux distribution (magnetic force line) formed by the solenoid coil 20 and the magnetic pole 22.
本発明において磁性ポール22を上記のような特定形状に
する理由は以下のような実験結果に基づいている。高さ
Ｈを50mm、下面直径D1を18mmφに固定し、上面直径D2を
0mmφ（円錐形）から18mmφ（円柱形）まで変えた７個
の磁性ポールを用い、金型の円筒状成形空間内への永久
磁石粉体の充填量を測定した。なお下ロッドの直径も18
mmφである。その測定結果を第２図に示す。The reason why the magnetic pole 22 has the above-described specific shape in the present invention is based on the following experimental results. Fix the height H to 50 mm and the bottom surface diameter D 1 to 18 mmφ, and set the top surface diameter D 2 to
Using 7 magnetic poles changed from 0 mmφ (conical) to 18 mmφ (cylindrical), the filling amount of the permanent magnet powder in the cylindrical molding space of the mold was measured. The diameter of the lower rod is also 18
mmφ. The measurement result is shown in FIG.
第２図から、上面直径D2の最適範囲は3mmφ以上である
といえる。ソレノイドコイルに流した一定の電流によっ
て発生する磁束が磁性ポールに流れる際、磁性ポールの
断面積が小さいと、磁束の全てが磁性ポールを通らず一
部が磁性ポールの外に漏洩する。そのため金型の円筒状
成形空間に流れる磁束が減少し、永久磁石粉体を成形空
間内に吸引する力が弱くなって充填量が減少する。また
15mmφを超えると、ソレノイドコイルと磁性ポールの上
部（入口付近）でのギャップが狭くなるため、永久磁石
粉体によっては（特に流動性が悪い粉体の場合）詰まり
易く、磁性ポールの上面中央に載っている永久磁石粉体
が落下し難くなり、充填量の低下が見られる。そのため
流動性の悪い粉体の場合にはD2≦５D1/6とすることが好
ましい。From FIG. 2 , it can be said that the optimum range of the upper surface diameter D 2 is 3 mmφ or more. When the magnetic flux generated by a constant current flowing in the solenoid coil flows in the magnetic pole, if the magnetic pole has a small cross-sectional area, all of the magnetic flux does not pass through the magnetic pole and a part leaks out of the magnetic pole. Therefore, the magnetic flux flowing in the cylindrical molding space of the mold is reduced, the force for attracting the permanent magnet powder into the molding space is weakened, and the filling amount is reduced. Also
If it exceeds 15 mmφ, the gap between the solenoid coil and the upper part of the magnetic pole (near the inlet) becomes narrower, so it is easy to get clogged with the permanent magnet powder (especially in the case of powder with poor fluidity), and at the center of the top surface of the magnetic pole. The permanent magnet powder on the surface is less likely to fall, and the filling amount is reduced. It is preferable that the D 2 ≦ 5D 1/6 in the case of for poor fluidity powder.
次に本発明方法に従い永久磁石粉体を充填した実験例に
ついて説明する。平均粒径1000μｍのサマリウム−コバ
ルト（Sm2Co17）系合金をジェットミルにより平均粒径
３μｍに粉砕した。この原料粉体を1.5g秤り取り、第１
図に示す装置を用いて外径18mmφ、内径16mmφ、高さ15
mmの円筒状の成形空間内に充填し、プレス成形圧3ton/c
m2で成形した。充填時間及び成形密度の測定結果を第１
表に示す。なお第１表において従来方法は、スライド式
充填治具に粉体を入れ、ダイス上で往復運動させること
により上記成形空間内に落下充填する自然落下と押し棒
による強制圧入とを併用した場合である。Next, an experimental example in which the permanent magnet powder is filled according to the method of the present invention will be described. A samarium-cobalt (Sm 2 Co 17 ) alloy having an average particle size of 1000 μm was pulverized by a jet mill to an average particle size of 3 μm. Weigh 1.5g of this raw material powder and
Using the device shown in the figure, outer diameter 18 mmφ, inner diameter 16 mmφ, height 15
Filling into the cylindrical molding space of mm, press molding pressure 3ton / c
Molded at m 2 . The measurement results of filling time and molding density are first
Shown in the table. It should be noted that in Table 1, the conventional method is a case in which the powder is put into a slide type filling jig and reciprocated on a die so as to drop and fill into the molding space and forced press fitting with a push rod. is there.
ここでＲは（最大値−最小値）を示し、σｎはｎ＝５で
のバラツキを示す。 Here, R represents (maximum value-minimum value), and σ n represents the variation when n = 5.
この第１表から本発明方法の方が成形密度が高く且つバ
ラツキも小さい。特に粉体の充填時間についてみれば、
本発明方法は従来方法に比べ1/10以下の極く短時間で良
好な充填が達成されることが判る。From Table 1, the method of the present invention has a higher molding density and less variation. Especially regarding the powder filling time,
It can be seen that the method of the present invention achieves good filling in an extremely short time of 1/10 or less as compared with the conventional method.
本発明における上記のような顕著な効果は主として粉体
の磁気的性質に起因するものであるから、永久磁石粉体
であれば前記サマリウム−コバルト系磁石粉体の他、フ
ェライト系、アルニコ系、或いはネオジウム−鉄−ボロ
ン系等の何れであっても同様の結果が得られる。焼結磁
石用の粉体のみならずボンド磁石用の粉体（樹脂と混練
した粉体）にも適用できることは言うまでもない。Since the remarkable effects as described above in the present invention are mainly caused by the magnetic properties of the powder, if it is a permanent magnet powder, besides the samarium-cobalt magnet powder, a ferrite magnet, an alnico magnet, Alternatively, the same result can be obtained regardless of whether it is a neodymium-iron-boron system or the like. It goes without saying that it can be applied not only to powder for sintered magnets but also to powder for bonded magnets (powder kneaded with resin).
［発明の効果］ 本発明は上記のように金型の円筒状成形空間の開口近傍
に中心軸方向が成形空間深さ方向にほぼ一致する向きに
ソレノイドコイルを設置すると共に、その中心軸に沿っ
て特定の比率の円錐台状の磁性ポールを設置し、交流磁
場を印加するように構成した永久磁石粉体の充填技術で
ある。このため永久磁石粉体に磁気的吸引力が働き、永
久磁石粉体がスムーズに流れ落ち、成形空間の開口部が
極端に狭い場合でもその磁気的吸引力によって永久磁石
粉体を迅速に該成形空間内に充填でき、薄肉円筒状の永
久磁石を非常に効率よく成形できる。永久磁石粉体を充
填する力となる交流磁場は磁性ポールによって中心部に
集められ金型の円筒状成形空間を通る磁束が多くなるた
め、弱い電流でも永久磁石粉体を成形空間内に有効に吸
引充填させることができる。[Advantages of the Invention] According to the present invention, as described above, the solenoid coil is installed in the vicinity of the opening of the cylindrical molding space of the mold in a direction in which the central axis direction substantially coincides with the depth direction of the molding space, and along the central axis thereof. It is a filling technology of permanent magnet powder in which a frustoconical magnetic pole having a specific ratio is installed and an alternating magnetic field is applied. For this reason, a magnetic attraction force acts on the permanent magnet powder, the permanent magnet powder smoothly flows down, and even if the opening of the molding space is extremely narrow, the magnetic attraction force causes the permanent magnet powder to quickly flow into the molding space. It can be filled inside, and a thin-walled cylindrical permanent magnet can be molded very efficiently. The alternating magnetic field, which is the force to fill the permanent magnet powder, is collected in the center by the magnetic pole and the magnetic flux passing through the cylindrical molding space of the mold increases, so that the permanent magnet powder can be effectively stored in the molding space even with a weak current. It can be filled by suction.
しかも本発明は永久磁石粉体を強制的に機械的に押し込
むのではなく磁気的吸引力によって充填するため、元の
粉体の形状がそのまま保たれ、そのため密度分布が均一
で成形体重量も一定となり、特性の揃った永久磁石を量
産できる。更に本発明は金型上部にソレノイドコイルと
磁性ポールを備えた充填装置を設置するだけであるか
ら、既存のどのような形態のプレス成形機にも適用可能
であり、粉体の粒径や状態等に関わりなく永久磁石を製
造する様々な分野で使用可能である。Moreover, since the present invention fills the permanent magnet powder by magnetic attraction rather than forcing it mechanically, the original shape of the powder is maintained as it is, so that the density distribution is uniform and the compact weight is constant. Therefore, it is possible to mass-produce permanent magnets with uniform characteristics. Furthermore, the present invention is applicable to any existing press-molding machine because it only needs to install a filling device equipped with a solenoid coil and a magnetic pole on the upper part of the mold, and the particle size and state of the powder can be applied. It can be used in various fields of manufacturing permanent magnets regardless of the above.
第１図は本発明方法で用いる成形用金型並びに充填用ソ
レノイドコイルと交流磁力線を示す説明図、第２図は磁
性ポールの形状と成形空間内への充填量との関係を示す
グラフである。 10……ダイス、12……下ロッド、14……下パンチ、18…
…成形空間、20……ソレノイドコイル、22……磁性ポー
ル、24……永久磁石粉体。FIG. 1 is an explanatory view showing a molding die used in the method of the present invention, a filling solenoid coil, and alternating magnetic force lines, and FIG. 2 is a graph showing the relationship between the shape of the magnetic pole and the filling amount into the molding space. . 10 …… dice, 12 …… lower rod, 14 …… lower punch, 18…
… Molding space, 20 …… solenoid coil, 22 …… magnetic pole, 24 …… permanent magnet powder.
Claims (4)
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すると共に、該ソレノイドコイル
の中心軸上に、上面直径が下面直径の1/6以上であり且
つ下面直径が円筒状成形空間を形成する金型の下ロッド
の直径と同一もしくはそれよりやや小さい円錐台状の磁
性ポールを設け、交流電流を供給して前記開口上方の永
久磁石粉体を前記成形空間内に充填することを特徴とす
る永久磁石粉体の充填方法。1. A solenoid coil is installed in the vicinity of an opening of a cylindrical molding space of a mold in such a direction that its central axis direction substantially coincides with the depth direction of the molding space, and an upper surface is located on the central axis of the solenoid coil. A frustoconical magnetic pole whose diameter is 1/6 or more of the lower surface diameter and whose lower surface diameter is the same as or slightly smaller than the diameter of the lower rod of the mold that forms the cylindrical molding space is provided to supply alternating current. And a permanent magnet powder above the opening is filled into the molding space.
求項１記載の充填方法。2. The filling method according to claim 1, wherein the permanent magnet powder is a powder for a sintered magnet.
用の粉体である請求項１記載の充填方法。3. The filling method according to claim 1, wherein the permanent magnet powder is a powder for a bonded magnet kneaded with a resin.
位置する磁性ポールとを非磁性の連結部材で結合一体化
した構造をなし、前記磁性ポールは上面直径が下面直径
の1/6以上であり且つ下面直径が円筒状成形空間を形成
する金型の下ロッドの直径と同一もしくはそれよりやや
小さい円錐台状の軟磁性体からなることを特徴とする永
久磁石粉体の充填装置。4. A structure in which a solenoid coil and a magnetic pole located along the central axis of the solenoid coil are combined and integrated by a non-magnetic connecting member, and the magnetic pole has an upper surface diameter of 1/6 or more of a lower surface diameter. A filling device for permanent magnet powder, which is made of a soft magnetic material having a truncated cone shape whose lower surface diameter is equal to or slightly smaller than the diameter of a lower rod of a mold forming a cylindrical molding space.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10405689A JPH0711013B2 (en) | 1989-04-24 | 1989-04-24 | Permanent magnet powder filling method and filling device |
| EP90301518A EP0393815B1 (en) | 1989-04-15 | 1990-02-13 | Method for packing permanent magnet powder |
| DE69008922T DE69008922T2 (en) | 1989-04-15 | 1990-02-13 | Process for packaging permanent magnetic powder. |
| US07/508,421 US5004580A (en) | 1989-04-15 | 1990-04-13 | Method and apparatus for packing permanent magnet powder |
| US07/607,267 US5135375A (en) | 1989-04-15 | 1990-10-31 | Apparatus for packing permanent magnet powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10405689A JPH0711013B2 (en) | 1989-04-24 | 1989-04-24 | Permanent magnet powder filling method and filling device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02282404A JPH02282404A (en) | 1990-11-20 |
| JPH0711013B2 true JPH0711013B2 (en) | 1995-02-08 |
Family
ID=14370536
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10405689A Expired - Fee Related JPH0711013B2 (en) | 1989-04-15 | 1989-04-24 | Permanent magnet powder filling method and filling device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0711013B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003053596A (en) * | 2001-08-17 | 2003-02-26 | Sumitomo Special Metals Co Ltd | Method for packing magnetic powder material and method for producing magnet |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1176476C (en) | 1999-12-09 | 2004-11-17 | 株式会社新王磁材 | Method and device for supplying magnetic powder, and magnet mfg. method |
-
1989
- 1989-04-24 JP JP10405689A patent/JPH0711013B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003053596A (en) * | 2001-08-17 | 2003-02-26 | Sumitomo Special Metals Co Ltd | Method for packing magnetic powder material and method for producing magnet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02282404A (en) | 1990-11-20 |
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