JP2862910B2 - Manufacturing method of bonded magnet - Google Patents
Manufacturing method of bonded magnetInfo
- Publication number
- JP2862910B2 JP2862910B2 JP23887689A JP23887689A JP2862910B2 JP 2862910 B2 JP2862910 B2 JP 2862910B2 JP 23887689 A JP23887689 A JP 23887689A JP 23887689 A JP23887689 A JP 23887689A JP 2862910 B2 JP2862910 B2 JP 2862910B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- bonded magnet
- magnetic field
- manufacturing
- passage
- 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.)
- Expired - Fee Related
Links
Description
【発明の詳細な説明】 ［産業上の利用分野］ この発明は、押出し成形によるボンド磁石の製造方法
に関する。Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a bonded magnet by extrusion molding.
［従来の技術］ ボンド磁石は、バリウムフェライト，ストロンチウム
フェライト等の磁性粉末とゴムまたは合成樹脂よりなる
バインダーを主成分とする複合磁石である。[Related Art] A bonded magnet is a composite magnet mainly composed of a magnetic powder such as barium ferrite or strontium ferrite and a binder made of rubber or synthetic resin.
従来の押出し成形によるボンド磁石の製造方法として
は、例えば特開昭60−194510号公報に開示のものがあ
る。As a conventional method for manufacturing a bonded magnet by extrusion molding, for example, there is one disclosed in JP-A-60-194510.
この開示の技術は、磁性粉末とバインダーとを混合し
た組成物を押し出す通路を波形の部分とストレート形状
の部分とをもつ磁性体で構成すると共に磁場を形成し、
この通路に前記組成物を通すことにより磁気的配向と成
形とを行うものである。According to the technology of this disclosure, a passage for extruding a composition obtained by mixing a magnetic powder and a binder is formed of a magnetic material having a corrugated portion and a straight portion, and forms a magnetic field,
Magnetic orientation and molding are performed by passing the composition through the passage.
この製造方法では、波形部分で磁場が多用に変化する
ため、磁性粉末が揺り動かされ、次のストレート部分で
は磁場が所定方向に揃っているから磁性粉末の配向が所
定方向に揃うことになる。In this manufacturing method, since the magnetic field changes frequently in the waveform portion, the magnetic powder is swung, and in the next straight portion, the magnetic field is aligned in the predetermined direction, so that the orientation of the magnetic powder is aligned in the predetermined direction.
［発明が解決しようとする課題］ 従来の押出し成形によるボンド磁石の製造方法におい
て得られる磁性粉末の配向率は、82％程度が上限であ
り、十分満足できるものではなかった。[Problem to be Solved by the Invention] The upper limit of the orientation ratio of the magnetic powder obtained by the conventional method of manufacturing a bonded magnet by extrusion molding is about 82%, which is not sufficiently satisfactory.
そこで、この発明の目的は、高い配向率を有し，優れ
た磁気特性をもつボンド磁石を押出し成形により製造す
る方法を提供することにある。Accordingly, an object of the present invention is to provide a method for manufacturing a bonded magnet having a high orientation ratio and excellent magnetic properties by extrusion.
［課題を解決するための手段］ この発明の押出し成形によるボンド磁石の製造方法
は、通路内にじゃま部材が突設されると共に所定方向に
磁場が形成された流動切替部と、通路断面積が小さい部
分から大きい部分に急変すると共に所定方向に磁場が形
成された膨張部と、通路断面積が徐々に大きくなると共
に磁場が形成されていない脱出部とを順に通らせて、ボ
ンド磁石用組成物の磁気的配向と成形とを行うことを構
成上の特徴とするものである。[Means for Solving the Problems] According to a method for manufacturing a bonded magnet by extrusion molding of the present invention, a flow switching section in which a baffle member is protruded in a passage and a magnetic field is formed in a predetermined direction, and a passage cross-sectional area is reduced. The composition for bonded magnets is made to pass through an expanding portion in which a magnetic field is formed in a predetermined direction while abruptly changing from a small portion to a large portion, and an escape portion in which a passage cross-sectional area gradually increases and a magnetic field is not formed. It is characterized in that the magnetic orientation and the shaping are performed.
上記構成において、じゃま部材は、多数の非磁性体製
ピンであるのが好ましい。その理由は、磁性体製とする
と、磁力線が集中するので、磁力線が望ましくない方向
に乱され、また、ボンド磁石用組成物の流れの抵抗が大
きくなってしまう問題を生じることがあるからである。In the above configuration, it is preferable that the baffle member is a large number of nonmagnetic pins. The reason is that when made of a magnetic material, the lines of magnetic force are concentrated, so that the lines of magnetic force are disturbed in an undesired direction, and a problem may occur that the resistance of the flow of the composition for bonded magnets increases. .
［作用］ この発明のボンド磁石の製造方法では、まず流動切替
部にて、ボンド磁石用組成物を物理的に流動せしめ、磁
性粉末を揺り動かすが、このとき所定方向に磁場が形成
されているため、磁性粉末はほぼ所定方向に配向する。[Operation] In the method for manufacturing a bonded magnet of the present invention, first, the composition for a bonded magnet is physically caused to flow in the flow switching section, and the magnetic powder is shaken. At this time, a magnetic field is formed in a predetermined direction. The magnetic powder is oriented substantially in a predetermined direction.
次に、膨張部において、急にボンド磁石用組成物の体
積が膨張させられるが、このときにも所定方向に磁場が
形成されているため、磁性体はさらに所定方向に配向す
るようになり、極めて高い配向率となる。Next, in the expanding section, the volume of the bonded magnet composition is suddenly expanded, but also at this time, since the magnetic field is formed in the predetermined direction, the magnetic substance is further oriented in the predetermined direction, An extremely high orientation ratio is obtained.
この後、脱出部を経て成形品として取り出されるが、
脱出部の通路断面積を徐々に大きくしていることによ
り、壁面抵抗による磁性粉末の配向率の低下が防止さ
れ、また、磁場吸引力による成形品の変形も防止され
る。After this, it is taken out as a molded product through the escape part,
By gradually increasing the cross-sectional area of the passage of the escape portion, a decrease in the orientation ratio of the magnetic powder due to the wall resistance is prevented, and the deformation of the molded product due to the magnetic attraction is also prevented.
従って、高い配向率の所定形状のボンド磁石が得られ
る。Therefore, a bonded magnet having a high orientation ratio and a predetermined shape can be obtained.
［実施例］ 以下、図面を参照してこの発明の実施例につき詳細に
説明する。なお、この実施例によりこの発明が限定され
るものではない。Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.
ボンド磁石用組成物の配合例（但し、下記において、
部は重量部を示す。）は、次のものである。Example of the composition of the bonded magnet composition (however, in the following,
Parts are parts by weight. ) Is as follows.
バリウムフェライト（平均粒子径１μｍ）…1950部， アクリロニトリルブタジエンゴム（NBR） …100部， ジオクチルフタレート（DOP） …20部， ステアリン酸亜鉛（滑剤） …17部 低分子オレフィン（滑剤） …20部 上記ボンド磁石用組成物を、第１図に示す押出し成形
装置100によって押出し成形し、シート状のボンド磁石
αを得た。Barium ferrite (average particle diameter 1 μm): 1950 parts, acrylonitrile butadiene rubber (NBR): 100 parts, dioctyl phthalate (DOP): 20 parts, zinc stearate (lubricant): 17 parts Low molecular olefin (lubricant): 20 parts The composition for a bonded magnet was extruded by an extruder 100 shown in FIG. 1 to obtain a sheet-shaped bonded magnet α.
第１図において、１ばバレル,2はスクリュー,3は非磁
性体のダイス,4は磁場形成用ヨーク,5は同じく磁性体ヨ
ーク,6は磁性体ヨーク５の上側から下側に向けて突出し
た非磁性体ピン,7は磁性体ヨーク５の下側から上側に向
けて突出した非磁性体ピン,8は通路開口面積が２分の１
になった圧縮部,9は急に通路開口面積が1.4倍になる膨
張部,10は徐々に通路開口面積が広がる脱出部である。In FIG. 1, 1 is a barrel, 2 is a screw, 3 is a non-magnetic die, 4 is a yoke for forming a magnetic field, 5 is a magnetic yoke, and 6 is a projection from the upper side to the lower side of the magnetic yoke 5. The non-magnetic pin 7 is a non-magnetic pin protruding upward from the lower side of the magnetic yoke 5, and 8 is a half of the passage opening area.
The compression part, 9 is an expansion part whose passage opening area suddenly becomes 1.4 times, and 10 is an escape part whose passage opening area gradually widens.
第２図は、磁性体ヨーク５とピン6,7とを取り出し
て、ダイス３側から見た外観図である。この第２図のＡ
−Ａ断面が第１図の該当部分になる。また、この第３図
のＢ−Ｂ断面は、第３図のようになる。なお、11は非磁
性体製の直方体形状のスペーサである。FIG. 2 is an external view of the magnetic body yoke 5 and the pins 6 and 7 taken out and viewed from the die 3 side. A in FIG.
The section A is the corresponding part in FIG. FIG. 3 is a sectional view taken along the line BB of FIG. Reference numeral 11 denotes a rectangular parallelepiped spacer made of a nonmagnetic material.
磁場の強さは12,000［Oe］（圧縮部８では20,000［O
e］）であり、磁場の方向は下向きである。The magnetic field strength is 12,000 [Oe] (20,000 [Oe
e]), and the direction of the magnetic field is downward.
なお、比較のために、非磁性体ピン6,7および圧縮部
構成部材8aを外した場合（ブランク）と、ピン6,7だけ
を取り付けた場合（ピン）と、圧縮部構成部材8aだけを
取り付けた場合（圧縮膨張）との各場合について押出し
成形し、ボンド磁石を得た。For comparison, the case where the non-magnetic material pins 6, 7 and the compression part constituting member 8a were removed (blank), the case where only the pins 6, 7 were attached (pin), and the case where only the compression part constituting member 8a was Extrusion molding was performed for each of the cases where it was attached (compression expansion), and a bonded magnet was obtained.
結果を第４図に示す。この第４図から理解されるよう
に、この発明の場合（ピン及び圧縮膨張）は、配向度お
よび磁気的特性が最も優れている。The results are shown in FIG. As understood from FIG. 4, in the case of the present invention (pin and compression / expansion), the degree of orientation and the magnetic properties are the most excellent.
このように優れた特性が得られるのは、高圧下のダイ
ス奥にてバルクで磁性粉末を揺動するよりも、高圧が解
放される出口部でダイスエルの限度近くまで膨張させる
方が磁性粉末の自由度が大きくなること、また、ピンで
予め予備運動させた方が圧縮膨張の効果が大きくなるこ
とによると考えられる。The reason why such excellent characteristics can be obtained is that expanding the magnetic powder near the limit of the die swell at the outlet where the high pressure is released is better than oscillating the magnetic powder in bulk at the back of the die under high pressure. It is considered that the degree of freedom is increased, and the effect of the pre-movement with the pin in advance increases the effect of compression and expansion.
なお、磁性粉末の自由度が大きくなる理由は、バイン
ダーがダイス内で受ける過歪が、大気圧近くまで低下し
たときに、内部的で均一な応力緩和を受けるためと考え
られる。It is considered that the reason why the degree of freedom of the magnetic powder is increased is that when the overstrain applied to the binder in the die decreases to near atmospheric pressure, internal and uniform stress relaxation occurs.
次に、磁場の強さを変えて本発明の押出し成形を行
い、得られたボンド磁石の残留磁束密度Brを測定した。
また、比較のために、ピン6,7だけを取り付けた場合に
ついても同様に測定した。Next, the extrusion molding of the present invention was performed while changing the strength of the magnetic field, and the residual magnetic flux density Br of the obtained bonded magnet was measured.
For comparison, the same measurement was performed when only the pins 6 and 7 were attached.
測定結果を第５図に示す。ａが本発明にかかるボンド
磁石であり、ｂがピン6,7だけの場合のボンド磁石であ
る。図示のように、この発明によって磁気的特性に優れ
たボンド磁石を得ることが出来る。The measurement results are shown in FIG. a is the bond magnet according to the present invention, and b is the bond magnet when only the pins 6 and 7 are provided. As shown, a bonded magnet having excellent magnetic characteristics can be obtained by the present invention.
［発明の効果］ この発明は上記した構成であるから、磁性粉末の配向
率が高く，優れた磁気特性を持つボンド磁石を得ること
が出来る。[Effects of the Invention] Since the present invention has the above-described configuration, a bonded magnet having a high orientation ratio of the magnetic powder and excellent magnetic properties can be obtained.
第１図はこの発明の製造方法に用いる押出し成形装置の
断面図、第２図は磁性体ヨーク５の部分を取り出してダ
イス側から見た外観図、第３図は第２図におけるＢ−Ｂ
断面図、第４図はこの発明の実施例によるボンド磁石と
比較例によるボンド磁石の性能を比較するための図表、
第５図は配向磁場の強さとボンド磁石の残留磁束密度の
関係を示す特性図である。 （符号の説明） 100……押出し成形装置 １……バレル ２……スクリュー ３……ダイス ４……ヨーク ５……磁性体ヨーク 6,7……ピン ８……圧縮部 8a……圧縮部構成部材 ９……膨張部 10……脱出部 11……スペーサ α……ボンド磁石。FIG. 1 is a cross-sectional view of an extrusion molding apparatus used in the manufacturing method of the present invention, FIG. 2 is an external view of a portion of a magnetic yoke 5 taken out and viewed from a die side, and FIG. 3 is BB in FIG.
FIG. 4 is a cross-sectional view, and FIG. 4 is a table for comparing the performance of the bonded magnet according to the embodiment of the present invention with the performance of the bonded magnet according to the comparative example;
FIG. 5 is a characteristic diagram showing a relationship between the strength of the orientation magnetic field and the residual magnetic flux density of the bonded magnet. (Description of Signs) 100 Extrusion Molding Device 1 Barrel 2 Screw 3 Dice 4 Yoke 5 Magnetic Yoke 6, 7 Pin 8 Compression Part 8a Compression Part Configuration Member 9: Expanding portion 10: Escape portion 11: Spacer α: Bonded magnet.
Claims (2)
定方向に磁場が形成された流動切替部と、通路断面積が
小さい部分から大きい部分に急変すると共に所定方向に
磁場が形成された膨張部と、通路断面積が徐々に大きく
なると共に磁場が形成されていない脱出部とを順に通ら
せて、ボンド磁石用組成物の磁気的配向と成形とを行う
ことを特徴とする押出し成形によるボンド磁石の製造方
法。1. A flow switching portion in which a baffle member protrudes into a passage and a magnetic field is formed in a predetermined direction, and a magnetic field is formed in a predetermined direction while abruptly changing from a small portion to a large portion in a passage cross-sectional area. By extrusion molding, the expanding section and the passage section are gradually increased and the escape section in which the magnetic field is not formed is sequentially passed, and the magnetic orientation and molding of the bonded magnet composition are performed. Manufacturing method of bonded magnet.
る請求項１の製造方法。2. The method according to claim 1, wherein the blocking member comprises a number of non-magnetic pins.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23887689A JP2862910B2 (en) | 1989-09-14 | 1989-09-14 | Manufacturing method of bonded magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23887689A JP2862910B2 (en) | 1989-09-14 | 1989-09-14 | Manufacturing method of bonded magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03101205A JPH03101205A (en) | 1991-04-26 |
| JP2862910B2 true JP2862910B2 (en) | 1999-03-03 |
Family
ID=17036577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23887689A Expired - Fee Related JP2862910B2 (en) | 1989-09-14 | 1989-09-14 | Manufacturing method of bonded magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2862910B2 (en) |
-
1989
- 1989-09-14 JP JP23887689A patent/JP2862910B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03101205A (en) | 1991-04-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |