JPS61172320A - Magnetic field injection-molding method - Google Patents
Magnetic field injection-molding methodInfo
- Publication number
- JPS61172320A JPS61172320A JP1249585A JP1249585A JPS61172320A JP S61172320 A JPS61172320 A JP S61172320A JP 1249585 A JP1249585 A JP 1249585A JP 1249585 A JP1249585 A JP 1249585A JP S61172320 A JPS61172320 A JP S61172320A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnetic
- clamping force
- mold
- mold cavity
- 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
-
- 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)
Abstract
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] (b) Industrial application field 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
スチックマグネッ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ャビティに磁
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
型キャビティ内に射出し、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、プラスチックマグネッ
トを得ることができる。(b) Conventional technology 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. Thereby, a plastic magnet can be obtained.
(ハ)廃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、プラスチックマ
グネッ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った。すなわち、プラスチックマ
グネットの磁気特性は、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。従って、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った。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5
2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 that Haimei attempts to solve 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. There was no improvement, 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. 4. Each magnetic particle 52 in the molten material 50 has an axis of easy magnetization 54, and when a magnetic field is applied, the axis of easy magnetization 54 is aligned with the direction of the magnetic field 56. It tries to rotate, but as shown in Figure 4, the magnetic particles 5
The two comrades interfere with each other, and the easy magnetization axes 54 of all the magnetic particles do not coincide with the magnetic field direction 56. In other words, 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
の金型キャビティ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ャビティの容積
が周期的に変動する。この金型キャビティの容積変動が
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1作用する磁場によっ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。従って、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、
プラスチックマグネッ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 the magnetic particles to make minute movements. As a result, each magnetic particle secures a predetermined location and is arranged without colliding with adjacent magnetic particles due to the applied magnetic field. Therefore, the phenomenon in which magnetic particles interfere with each other during orientation is prevented from occurring, and the orientation rate of the magnetic particles is improved. Since the orientation rate is improved, sufficient orientation can be achieved even if the mixing ratio of the magnetic particles is increased, and both the mixing ratio and the orientation ratio of the magnetic particles are increased.
The magnetic properties of plastic magnets can be significantly improved.
(へ)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によって連結されて
おり、可動盤16がタイバー14によって案内されて移
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とによって金型キャビティ22が形成され
る。FIG. 2 shows an example of a magnetic field injection molding machine, in which a fixed platen 10 and a mold clamping housing 12 are connected by tie bars 14, and a movable platen 16 is guided by the tie bars 14 and is movable. A fixed die 18 is attached to the fixed platen 10, a movable die 20 is attached to the movable platen 16, and the fixed die 18 is attached to the movable platen 16.
A mold cavity 22 is formed by the movable mold 20 and the movable mold 20 .
金型キャビティ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、これによって軸方向に駆動可能である。型締
シリンダ28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によって制御さ
れる。すなわち、電磁リリーフ弁34はソレノイド34
a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40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
。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 installed on the outer periphery of the fixed mold 18 and the movable mold 20 in the clamped state.
is placed. The movable platen 16 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. Hydraulic pressure from a hydraulic source 32 acts on the mold clamping cylinder 28,
The oil pressure of the oil pressure source 32 is controlled by an electromagnetic relief valve 34. That is, the electromagnetic relief valve 34 is the solenoid 34
The hydraulic pressure supplied to the mold clamping cylinder 28 is adjusted by discharging a portion of the oil discharged from the hydraulic pressure source 32 according to the operating state of the hydraulic pressure source 32. 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, an angular frequency setting device 40, and an amplitude setting device 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、を閉じを行わ
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。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 cause it to close. 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.
可動型20が固定型18に接触したことがリミットスイ
ッチなどの図示してない位置検出器によって検出される
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 = I O+
I 1 ・sin ωt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Io、工
1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によってそれぞれ設定される。When the contact of the movable mold 20 with the fixed mold 18 is detected by a position detector (not shown) such as a limit switch, the sequence controller 44 gives a command to the control device 36, and the control device 36 sets a predetermined current I = IO+
A command signal is given to the amplifier 38 to energize the solenoid 34a with I 1 ·sin ωt. Here, Io, work 1 and ω are the mold clamping force setter 39 and the amplitude setter 42, respectively.
and the angular frequency setter 40, respectively.
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Ioを通電する
ように制御される。この電流工0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。従って、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Ioに対応する型締
力をFo、及び電流工1に対応する型締力をFlとする
と、所定時間経過までの型締力FはF=Fo+F1参5
in(I)tで示される。従ッテ、型締力は第1図に示
すように変化することになる。この型締力によって固定
型18及び可動型20が弾性変形し、金型キャビティ2
2の容積が変化する。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 Io. This supply of electric current 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. If the mold clamping force corresponding to the current Io is Fo, and the mold clamping force corresponding to the electric current 1 is Fl, the mold clamping force F until the predetermined time elapses is F=Fo+F1.
Indicated by in(I)t. Consequently, 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 mold cavity 2
The volume of 2 changes.
従って、型締力が振動する所定の時間の間は金型キャど
ティ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
装置によって所定の電流が供給され、金型キャビティ2
2には所定の磁場が発生する。磁場が安定したあと金型
キャビティ22内に射出シリング24から磁性粒子を含
む溶融材料が射出される。金型キャビティ22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によって設定された所定時間中は金型
キャビティ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っ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0次いで、所定時間経過後は型締
力を一定にし、金型キャビティ22の容積の変動を停止
させ、一定の磁場によっ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っ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
、プラスチックマグネッ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26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1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。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 by a power supply device (not shown) from the time the mold closing process is completed, and the mold cavity 2
2, a predetermined magnetic field is generated. After the magnetic field is stabilized, molten material containing magnetic particles is injected into the mold cavity 22 from the injection sill 24. The magnetic particles in the molten material injected into the mold cavity 22 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 secure their respective optimal positions due to this vibration. Then, 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. 3, where the axis of easy magnetization 54 of most of the magnetic particles 52 in the molten material 50 coincides with the magnetic field direction 56. Thereby, the magnetic properties of the plastic magnet can be significantly improved. Note that the supply of electricity to the magnetic field generating coil 26 is stopped after the magnetization is completed, and then the molded product is cooled. During this time, the molded product is demagnetized, the mold clamping force is removed, the mold is opened, and the molded product is taken out.
(ト)発明の詳細
な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ャビティの容積を変動させ、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ックマグネットの磁気特性を
大幅に向上することができる。(G) As described in detail, 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.
【図面の簡単な説明】
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、・・φ金型キャ
ビティ、24拳・・射出シリンダ、26・・・磁場発生
コイル、28・・・型締シリンダ、32−Φ−油圧源、
34・・・電磁リリーフ弁、36・φΦ制御装置、44
・・會シーケンスコントローラ。[Brief Description of the Drawings] 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, and Fig. 3 is a diagram showing the orientation state of magnetic particles according to the present invention. , FIG. 4 is a diagram showing the orientation state of magnetic particles by the conventional magnetic field injection molding method. 18...Fixed type, 20...Movable type,...φ mold cavity, 24 fist...Injection cylinder, 26...Magnetic field generating coil, 28...Mold clamping cylinder, 32-φ-hydraulic source ,
34...Electromagnetic relief valve, 36・φΦ control device, 44
... Meeting sequence controller.
Claims (1)
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。[Claims] 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 period between a predetermined upper limit value and a predetermined lower limit value is cycled for a predetermined time from completion of mold closing. A magnetic field injection molding method characterized in that a mold clamping force that fluctuates over time is applied, and a constant mold clamping force is applied after a predetermined period of 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 true JPS61172320A (en) | 1986-08-04 |
JPH0241882B2 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 |
---|---|
JPH0241882B2 (en) | 1990-09-19 |
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