JPH0241882B2 - - Google Patents
Info
- Publication number
- JPH0241882B2 JPH0241882B2 JP1249585A JP1249585A JPH0241882B2 JP H0241882 B2 JPH0241882 B2 JP H0241882B2 JP 1249585 A JP1249585 A JP 1249585A JP 1249585 A JP1249585 A JP 1249585A JP H0241882 B2 JPH0241882 B2 JP H0241882B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- magnetic field
- magnetic particles
- mold clamping
- magnetic
- 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
Links
- 239000006249 magnetic particle Substances 0.000 claims description 38
- 238000001746 injection moulding Methods 0.000 claims description 12
- 239000012768 molten material Substances 0.000 claims description 11
- 230000005415 magnetization Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/0013—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor using fillers dispersed in the moulding material, e.g. metal particles
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Description
【発明の詳細な説明】
(イ) 産業上の利用分野
本発明は、磁場射出成形方法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a magnetic field injection molding method.
(ロ) 従来の技術
磁場射出成形は、磁性粒子を溶融材料中に混入
し、プラスチツクマグネツトなどを成形する方法
である。すなわち、磁場発生コイルに電流を流し
て金型キヤビテイに磁場を発生させた状態で磁性
粒子を混入した溶融材料を金型キヤビテイ内に射
出し、磁性粒子を磁場方向に配向させて冷却固化
する。これにより、プラスチツクマグネツトを得
ることができる。(B) Prior Art Magnetic field injection molding is a method for molding plastic magnets and the like by mixing magnetic particles into a molten material. That is, a molten material mixed with magnetic particles is injected into the mold cavity while a current is passed through a magnetic field generating coil to generate a magnetic field in the mold cavity, the magnetic particles are oriented in the direction of the magnetic field, and the material is cooled and solidified. In this way, a plastic magnet can be obtained.
(ハ) 発明が解決しようとする問題点
しかし、従来の磁場射出成形方法には、プラス
チツクマグネツトの磁気特性をある程度以上向上
することができないという問題点があつた。すな
わち、プラスチツクマグネツトの磁気特性は、磁
性粒子が同一の場合には、一般に磁性粒子の混合
比が高いほど、また磁性粒子の配向率が高いほ
ど、向上する。従つて、磁性粒子の混合比を大き
くすれば磁気特性が向上するはずであるが、実際
には磁性粒子の混合比をある程度以上大きくして
も、これに応じて配向率が低下するため磁気特性
は向上せず、磁性粒子の混合比には限界があつ
た。すなわち、磁場中で配向しようとする磁性粒
子同志が機械的に接触し、磁性粒子の配向が互い
の干渉により妨げられる。この状態を第４図に概
念的に示す。溶融材料５０中の各磁性粒子５２は
磁化容易軸５４を有しており、磁場が作用すると
その磁化容易軸５４を磁場方向５６と一致させる
ように回転しようとするが、第４図に示すよう
に、磁性粒子５２同志が互いに干渉し、すべての
磁性粒子の磁化容易軸５４が磁場方向５６と一致
した状態とはならない。すなわち、配向率に限界
がある。本発明は、上記のような問題点を解決す
ることを目的としている。(c) Problems to be Solved by the Invention However, the conventional magnetic field injection molding method has the problem that the magnetic properties of plastic magnets cannot be improved beyond a certain level. That is, when the magnetic particles are the same, the magnetic properties of a plastic magnet generally improve as the mixing ratio of the magnetic particles increases and as the orientation rate of the magnetic particles increases. Therefore, increasing the mixing ratio of magnetic particles should improve the magnetic properties, but in reality, even if the mixing ratio of magnetic particles is increased beyond a certain level, the orientation rate decreases accordingly, so the magnetic properties do not improve. was not improved, and there was a limit to the mixing ratio of magnetic particles. That is, magnetic particles attempting to align in a magnetic field mechanically contact each other, and the alignment of the magnetic particles is hindered by mutual interference. This state is conceptually shown in FIG. Each magnetic particle 52 in the molten material 50 has an axis of easy magnetization 54, and when a magnetic field acts on it, it tries to rotate so that the axis of easy magnetization 54 coincides with the direction of the magnetic field 56, but as shown in FIG. In addition, the magnetic particles 52 interfere with each other, and the easy magnetization axes 54 of all the magnetic particles do not coincide with the magnetic field direction 56. That is, there is a limit to the orientation rate. The present invention aims to solve the above problems.
(ニ) 問題点を解決するための手段
本発明は、型締の最初の段階で型締力を周期的
に変動させることにより、上記問題点を解決す
る。すなわち、本発明による磁場射出成形方法
は、型閉じ完了から所定時間は所定の上限値と下
限値との間を周期的に変動する型締力を作用さ
せ、次いで所定時間経過後は一定の型締力を作用
させることを特徴としている。(d) Means for solving the problems The present invention solves the above problems by periodically varying the mold clamping force at the initial stage of mold clamping. That is, in the magnetic field injection molding method according to the present invention, a mold clamping force that periodically fluctuates between a predetermined upper limit value and a lower limit value is applied for a predetermined time after the completion of mold closing, and then a constant mold clamping force is applied after a predetermined time elapses. It is characterized by applying a tightening force.
(ホ) 作用
上記のようにすることにより、磁性粒子を含む
溶融材料の金型キヤビテイ内への射出工程の最初
の段階で型締力が周期的に変動し、これに応じて
金型キヤビテイの容積が周期的に変動する。この
金型キヤビテイの容積変動が溶融材料中の磁性粒
子に作用し、磁性粒子が微小な運動をする。これ
により、磁性粒子はそれぞれ所定の場所を確保
し、作用する磁場によつて隣接する磁性粒子同志
が衝突することなく配列される。従つて、配向さ
れる際に磁性粒子同志が互いに妨げ合うという現
象の発生が防止され、磁性粒子の配向率が向上す
る。配向率が向上するため磁性粒子の混合比を増
大しても十分に配向させることができ、磁性粒子
の混合比及び配向率が共に増大し、プラスチツク
マグネツトの磁気特性を大幅に向上することがで
きる。(e) Effect By doing the above, the mold clamping force changes periodically at the first stage of the injection process of the molten material containing magnetic particles into the mold cavity, and the mold cavity changes accordingly. The volume fluctuates periodically. This variation in the volume of the mold cavity acts on the magnetic particles in the molten material, causing minute movements of the magnetic particles. As a result, each magnetic particle secures a predetermined location, and the magnetic field that acts causes adjacent magnetic particles to be arranged without colliding with each other. Therefore, the phenomenon in which the magnetic particles interfere with each other during orientation is prevented from occurring, and the orientation rate of the magnetic particles is improved. Because the orientation rate is improved, it is possible to achieve sufficient orientation even when the mixing ratio of magnetic particles is increased, and both the mixing ratio and orientation ratio of magnetic particles are increased, and the magnetic properties of the plastic magnet can be greatly improved. can.
(ヘ) 実施例
以下、本発明の実施例を添付図面の第１〜３図
に基づいて説明する。(F) Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 3 of the accompanying drawings.
第２図に磁場射出成形機の１例を示す。固定盤
１０と型締ハウジング１２とがタイバー１４によ
つて連結されており、可動盤１６がタイバー１４
によつて案内されて移動可能である。固定盤１０
に固定型１８が取り付けられ、可動盤１６に可動
型２０が取り付けられ、固定型１８と可動型２０
とによつて金型キヤビテイ２２が形成される。金
型キヤビテイ２２には、射出シリンダ２４から磁
性粒子を含む溶融材料を注入可能である。型締し
た状態の固定型１８及び可動型２０の外周には磁
場発生コイル２６が配置される。可動盤１６は、
型締ハウジング１２に取り付けられた型締シリン
ダ２８のピストン３０と連結されており、これに
よつて軸方向に駆動可能である。型締シリンダ２
８には油圧源３２からの油圧が作用するが、油圧
源３２の油圧は電磁リリーフ弁３４によつて制御
される。すなわち、電磁リリーフ弁３４はソレノ
イド３４ａの作動状態に応じて油圧源３２からの
吐出油の一部を排出することにより、型締シリン
ダ２８へ供給される油圧を調整する。ソレノイド
３４ａには制御装置３６からの信号に基づいて作
動する増幅器３８から電流が供給される。制御装
置３６は、型締力設定器３９、角振動数設定器４
０及び振幅設定器４２を有している。制御装置３
６は、射出成形機の作動を制御するシーケンスコ
ントローラ４４及びタイマー４６により後述のよ
うに作用する。 Figure 2 shows an example of a magnetic field injection molding machine. The fixed platen 10 and the mold clamping housing 12 are connected by tie bars 14, and the movable platen 16 is connected to the tie bars 14.
It is possible to move by being guided by. Fixed plate 10
The fixed mold 18 is attached to the movable platen 16, the movable mold 20 is attached to the movable platen 16, and the fixed mold 18 and the movable mold 20
A mold cavity 22 is formed by this. A molten material containing magnetic particles can be injected into the mold cavity 22 from an injection cylinder 24 . A magnetic field generating coil 26 is arranged around the outer periphery of the fixed mold 18 and the movable mold 20 in a clamped state. The movable plate 16 is
It is connected to a piston 30 of a mold clamping cylinder 28 attached to the mold clamping housing 12, and thereby can be driven in the axial direction. Mold clamping cylinder 2
Hydraulic pressure from a hydraulic source 32 acts on the hydraulic pressure source 8 , and the hydraulic pressure of the hydraulic source 32 is controlled by an electromagnetic relief valve 34 . That is, the electromagnetic relief valve 34 adjusts the oil pressure supplied to the mold clamping cylinder 28 by discharging a portion of the oil discharged from the oil pressure source 32 according to the operating state of the solenoid 34a. Current is supplied to the solenoid 34a from an amplifier 38 that operates based on a signal from a control device 36. The control device 36 includes a mold clamping force setting device 39 and an angular frequency setting device 4.
0 and an amplitude setter 42. Control device 3
6 operates as described later by a sequence controller 44 and a timer 46 that control the operation of the injection molding machine.
磁場射出成形機による型締、成形、着磁等の動
作は以下のようにして行われる。まず、型開き状
態にある射出成形機の型締シリンダ２８に油圧を
供給し、型閉じを行わせる。すなわち、第２図中
で左方向に移動していた可動盤１６を右向きに移
動させ、可動型２０を固定型１８に接触させる。
可動型２０が固定型１８に接触したことがリミツ
トスイツチなどの図示してない位置検出器によつ
て検出されると、シーケンスコントローラ４４は
制御装置３６に指令を与え、制御装置３６は所定
の電流Ｉ＝I0＋I1・sinωtをソレノイド３４ａに通
電するように増幅器３８に指令信号を与える。こ
こでI0、I1及びωはそれぞれ型締力設定器３９、
振幅設定器４２及び角振動数設定器４０によつて
それぞれ設定される。この電流の供給はタイマー
４６に設定された所定時間だけ継続し、所定時間
経過後は一定の電流I0を通電するように制御され
る。この電流I0の供給はシーケンスコントローラ
４４から着磁工程の終了が指令されるまで継続さ
れる。電磁リリーフ弁３４はソレノイド３４ａに
通電される電流に応じて油圧源３２の圧力を制御
し、これを型締シリンダ２８に作用させる。従つ
て、型締シリンダ２８の押し力、すなわち型締力
はソレノイド３４ａへの通電量に応じて制御され
る。電流I0に対応する型締力F0、及び電流I1に対
応する型締力をF1とすると、所定時間経過まで
の型締力ＦはＦ＝F0＋F1・sinωtで示される。従
つて、型締力は第１図に示すように変化すること
になる。この型締力によつて固定型１８及び可動
型２０が弾性変形し、金型キヤビテイ２２の容積
が変化する。従つて、型締力が振動する所定の時
間の間は金型キヤビテイ２２の容積も振動するこ
とになる。一方、磁場発生コイル２６には型閉じ
工程完了時から図示してない電源装置によつて所
定の電流が供給され、金型キヤビテイ２２には所
定の磁場が発生する。磁場が安定したあと金型キ
ヤビテイ２２内に射出シリンダ２４から磁性粒子
を含む溶融材料が射出される。金型キヤビテイ２
２内に射出された溶融材料中の磁性粒子は磁場方
向に配向させられる。タイマー４６によつて設定
された所定時間中は金型キヤビテイ２２の容積が
周期的に変動するため、溶融材料及びこれに含ま
れる磁性粒子も振動状態となり、磁性粒子はこの
振動によつてそれぞれ最適位置を確保しつつ配向
されることになる。次いで、所定時間経過後は型
締力は一定にし、金型キヤビテイ２２の容積の変
動を停止させ、一定の磁場によつて磁性粒子を十
分に配向させる。これにより磁性粒子の配向率は
大幅に向上し、磁性粒子の混合比が高い場合であ
つても確実に配向させることができる。この場合
の磁性粒子の配向状態を第３図に概念的に示す。
溶融材料５０中の大部分の磁性粒子５２の磁化容
易軸５４が磁場方向５６に一致する。これによ
り、プラスチツクマグネツトの磁気特性を大幅に
向上することができる。なお、磁場発生コイル２
６への通電は着磁完了後には停止され、次いで成
形品の冷却が行われる。その間、成形品の消磁を
行い、次いで型締力を除去し、型開きし、成形品
の取り出しを行う。 Operations such as mold clamping, molding, and magnetization by the magnetic field injection molding machine are performed as follows. First, hydraulic pressure is supplied to the mold clamping cylinder 28 of the injection molding machine, which is in the mold open state, to close the mold. That is, the movable platen 16, which had been moving leftward in FIG. 2, is moved rightward, and the movable mold 20 is brought into contact with the fixed mold 18.
When a position detector (not shown) such as a limit switch detects that the movable mold 20 has contacted the fixed mold 18, the sequence controller 44 gives a command to the control device 36, and the control device 36 controls the predetermined current I. A command signal is given to the amplifier 38 to energize the solenoid 34a with =I 0 +I 1 ·sinωt. Here, I 0 , I 1 and ω are the mold clamping force setting device 39,
They are set by the amplitude setter 42 and the angular frequency setter 40, respectively. The supply of this current continues for a predetermined time set in the timer 46, and after the predetermined time has elapsed, it is controlled to supply a constant current I0 . The supply of this current I 0 is continued until the sequence controller 44 commands the end of the magnetization process. The electromagnetic relief valve 34 controls the pressure of the hydraulic power source 32 according to the current applied to the solenoid 34a, and causes the pressure to act on the mold clamping cylinder 28. Therefore, the pushing force of the mold clamping cylinder 28, that is, the mold clamping force, is controlled according to the amount of current applied to the solenoid 34a. When the mold clamping force F 0 corresponding to the current I 0 and the mold clamping force corresponding to the current I 1 are F 1 , the mold clamping force F until a predetermined time elapses is expressed as F=F 0 +F 1 ·sinωt. Therefore, the mold clamping force changes as shown in FIG. The fixed mold 18 and the movable mold 20 are elastically deformed by this mold clamping force, and the volume of the mold cavity 22 is changed. Therefore, during the predetermined time period in which the mold clamping force oscillates, the volume of the mold cavity 22 also oscillates. On the other hand, a predetermined current is supplied to the magnetic field generating coil 26 from the time when the mold closing process is completed by a power supply device (not shown), and a predetermined magnetic field is generated in the mold cavity 22. After the magnetic field is stabilized, molten material containing magnetic particles is injected into the mold cavity 22 from the injection cylinder 24. Mold cavity 2
The magnetic particles in the molten material injected into 2 are oriented in the direction of the magnetic field. During the predetermined time set by the timer 46, the volume of the mold cavity 22 changes periodically, so the molten material and the magnetic particles contained therein are also in a vibrating state, and the magnetic particles are adjusted to their optimum state by this vibration. It will be oriented while ensuring the position. Next, after a predetermined period of time has elapsed, the mold clamping force is kept constant, the volume of the mold cavity 22 stops changing, and the magnetic particles are sufficiently oriented by a constant magnetic field. As a result, the orientation rate of the magnetic particles is greatly improved, and even when the mixing ratio of the magnetic particles is high, the orientation can be ensured. The orientation state of the magnetic particles in this case is conceptually shown in FIG.
The easy axis of magnetization 54 of most of the magnetic particles 52 in the molten material 50 coincides with the magnetic field direction 56 . This allows the magnetic properties of the plastic magnet to be significantly improved. In addition, the magnetic field generating coil 2
6 is stopped after magnetization is completed, and then the molded product is cooled. During this time, the molded product is demagnetized, the clamping force is removed, the mold is opened, and the molded product is taken out.
(ト) 発明の効果
以上説明してきたように、本発明によると、型
締力を周期的に変動させて金型キヤビテイの容積
を変動させ、磁性粒子の配向を十分に行わせるよ
うにしたので、磁性粒子の配向率が向上しプラス
チツクマグネツトの磁気特性を大幅に向上するこ
とができる。(G) Effects of the Invention As explained above, according to the present invention, the volume of the mold cavity is varied by periodically varying the mold clamping force, and the magnetic particles are sufficiently oriented. , the orientation rate of the magnetic particles is improved, and the magnetic properties of the plastic magnet can be greatly improved.
第１図は本発明による型締力の特性を示す図、
第２図は磁場射出成形機を示す図、第３図は本発
明による磁性粒子の配向状態を示す図、第４図は
従来の磁場射出成形方法による磁性粒子の配向状
態を示す図である。
１８……固定型、２０……可動型、……金型キ
ヤビテイ、２４……射出シリンダ、２６……磁場
発生コイル、２８……型締シリンダ、３２……油
圧源、３４……電磁リリーフ弁、３６……制御装
置、４４……シーケンスコントローラ。
FIG. 1 is a diagram showing the characteristics of mold clamping force according to the present invention;
FIG. 2 is a diagram showing a magnetic field injection molding machine, FIG. 3 is a diagram showing the orientation state of magnetic particles according to the present invention, and FIG. 4 is a diagram showing the orientation state of the magnetic particles according to the conventional magnetic field injection molding method. 18... Fixed type, 20... Movable type,... Mold cavity, 24... Injection cylinder, 26... Magnetic field generating coil, 28... Mold clamping cylinder, 32... Hydraulic power source, 34... Electromagnetic relief valve , 36...control device, 44...sequence controller.
Claims (1)
子を含む溶融材料を射出する磁場射出成形方法に
おいて、 型閉じ完了から所定時間は所定の上限値と下限
値との間を周期的に変動する型締力を作用させ、
所定時間経過後は一定の型締力を作用させること
を特徴とする磁場射出成形方法。[Scope of Claims] 1. In a magnetic field injection molding method in which a molten material containing magnetic particles is injected into a mold cavity in which a magnetic field is generated, a predetermined period of time from completion of mold closing is between a predetermined upper limit value and a predetermined lower limit value. Applying periodically fluctuating mold clamping force,
A magnetic field injection molding method characterized by applying a constant mold clamping force after a predetermined time has elapsed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1249585A JPS61172320A (en) | 1985-01-28 | 1985-01-28 | Magnetic field injection-molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1249585A JPS61172320A (en) | 1985-01-28 | 1985-01-28 | Magnetic field injection-molding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61172320A JPS61172320A (en) | 1986-08-04 |
| JPH0241882B2 true JPH0241882B2 (en) | 1990-09-19 |
Family
ID=11806955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1249585A Granted JPS61172320A (en) | 1985-01-28 | 1985-01-28 | Magnetic field injection-molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61172320A (en) |
-
1985
- 1985-01-28 JP JP1249585A patent/JPS61172320A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61172320A (en) | 1986-08-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4120922A (en) | Method for molding | |
| JPH0379169B2 (en) | ||
| CA2847995A1 (en) | Molding systems and methods | |
| JPH0241882B2 (en) | ||
| JPH0560825U (en) | Clamping device for injection molding machine | |
| JPS61194703A (en) | Control of injection molding in magnetic field | |
| JP2997285B2 (en) | Injection molding machine and injection molding method | |
| JPS6079920A (en) | Magnetic-erasing process at injection molding in magnetic field | |
| JPH0663954A (en) | Mold opening and closing mechanism | |
| JPS61154823A (en) | Method of controlling clamping force of injection molding machine | |
| JPS55162204A (en) | Manufacture of anisotropic cylindrical polymer magnet | |
| JPS588571B2 (en) | Simultaneous orientation magnetization method in injection molding | |
| JPH0622172B2 (en) | Demagnetization control method for magnetic field injection molding machine | |
| JPH0261888B2 (en) | ||
| JPS59130410A (en) | Mold clamping apparatus for plastic magnetic injection molding machine | |
| JP2799903B2 (en) | Control device for injection molding machine | |
| JPH01101612A (en) | Magnetization of magnetic field injection molding equipment | |
| JPH077134Y2 (en) | Injection machine injection machine | |
| JPS55162203A (en) | Manufacture of anisotropic cylindrical polymer magnet | |
| JPH0469223A (en) | Mold opening/locking controlling apparatus for injection molding machine | |
| JPS6313726A (en) | Method and equipment for injection compression molding | |
| JPH03153330A (en) | Mold clamping device | |
| JPH04373B2 (en) | ||
| JPH0361017A (en) | Control method and its device for injection pressure of injection molding machine | |
| JPH01255517A (en) | Control method and device for motorized injection molding machine |