JP3932985B2 - Press molding apparatus and press molding method - Google Patents

Press molding apparatus and press molding method Download PDF

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Publication number
JP3932985B2
JP3932985B2 JP2002163421A JP2002163421A JP3932985B2 JP 3932985 B2 JP3932985 B2 JP 3932985B2 JP 2002163421 A JP2002163421 A JP 2002163421A JP 2002163421 A JP2002163421 A JP 2002163421A JP 3932985 B2 JP3932985 B2 JP 3932985B2
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induction coil
mold
press molding
molding apparatus
frequency current
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JP2004009387A (en
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研吾 貝沼
浩一 岡本
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Fuji Electric Co Ltd
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Fuji Electric Device Technology Co Ltd
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    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/02—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles
    • B29C43/021—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles characterised by the shape of the surface
    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/52—Heating or cooling
    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/58—Measuring, controlling or regulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/34—Heating or cooling presses or parts thereof
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
    • C03B11/06—Construction of plunger or mould
    • C03B11/08—Construction of plunger or mould for making solid articles, e.g. lenses
    • C03B11/088—Flat discs
    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/52—Heating or cooling
    • B29C2043/522—Heating or cooling selectively heating a part of the mould to achieve partial heating, differential heating
    • 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
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/58—Measuring, controlling or regulating
    • B29C2043/5816—Measuring, controlling or regulating temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2011/00—Optical elements, e.g. lenses, prisms
    • B29L2011/0016—Lenses
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2215/00—Press-moulding glass
    • C03B2215/40—Product characteristics
    • C03B2215/44—Flat, parallel-faced disc or plate products

Description

【０００１】
【発明の属する技術分野】
本発明は、プレス成形装置およびプレス成形方法に関し、特に、磁気ディスク等に適用されるガラス基板等を製造するのに好適なプレス成形装置およびプレス成形方法に関する。
【０００２】
【従来の技術】
従来から、ガラスやプラスチック等の原材料からなる基板を備えた磁気ディスクが幅広く用いられている。このような磁気ディスク用の基板は、極めて平滑な表面を有していることが求められることから、当初、ガラス材等を所定のサイズに切り抜くと共に、その表面を平滑に研磨することにより製造されていた。しかしながら、このようにディスク用の基板を１枚ずつ作製する手法は、多数の工程と手間を要するものであり、基板の製造コストを低減させる上で大きな問題を有していた。このため、近年では、基板の作製に際して、金型内でガラス等の原材料を加熱、加圧等することにより、その原材料に所望の形状を高精度に転写するプレス成形法が採用されるようになってきている。
【０００３】
かかるプレス成形法は、一般に次のような手順に従って行われる。まず、上下の型間（固定型と可動型との間）に原材料となるガラス材等を配置し、金型等の周辺を真空または不活性ガス雰囲気とする。更に、所定の熱源により、金型と原材料とを加熱し、金型および原材料が所定温度に達したならば、金型間で原材料を加圧する。そして、加圧完了後、成形品は、冷却され、金型から取り出される。このようなプレス成形法によれば、成形品に対する後処理が不要となり、高品質な基板を安価に大量生産することが可能となる。
【０００４】
ここで、ディスク用基板の成形のように高い加工精度が要求される場合には、金型の温度管理が極めて重要となる。このため、金型および原材料の加熱方式として、温度制御性が良好な高周波誘導加熱方式を採用することが多い。高周波誘導加熱方式を採用するプレス成形装置では、高周波電源に接続された誘導コイルが、導電性を有する金型の周囲に配置される。誘導コイルに高周波電流（交番電流）が供給されると、金型周辺に磁場が形成されて金型には渦電流が流れ、その電流損失により金型自体が発熱することになる。このような高周波誘導加熱方式によれば、被加熱体である金型等を被接触で効率よく加熱可能となり、被加熱体の省熱容量化や設備のクリーン化を図ることもできる。
【０００５】
【発明が解決しようとする課題】
しかしながら、最終的に外径と板厚との比が大きくなるディスク用の基板をプレス成形する場合、原材料として比較的厚さが大きい球状またはマーブル形状の原材料が用いられることから、型同士の相対移動量をある程度大きくせざるを得ない。このため、高周波誘導加熱方式を採用したとしても、誘導コイルと型（特に可動型）との相対位置関係が変動し、２つの型に対する入熱状態が変化する。各型への入熱状態の変化は、２つの型の間に温度差が生じさせ、それにより、高精度なプレス成形の実行が妨げられてしまう。
【０００６】
かかる問題を解消するためには、例えば、誘導コイルを金型の軸方向に移動させることや、コイルの巻きピッチを金型の軸方向において変化させること等が考えられる。しかしながら、これらの手法を採用しても、型の移動に良好に追従するように各型の温度を制御することは困難である。また、特開平６−６４９３２号公報には、固定型および可動型の周囲に２体の誘導コイルを配置すると共に、１体の高周波電源の発振周波数を制御して各誘導コイルへの高周波電流の量を変化させることにより、型同士間の温度差を抑制する手法が開示されている。しかしながら、かかる手法によって各誘導コイルへの高周波電流の量を自在に変化させるのは、極めて複雑かつ高価な制御回路等を用いたとしても容易なことではなく、当該手法により、各型の温度を型締めに良好に追従するように制御することは実質的に不可能に近い。この結果、ディスク用基板等のプレス成形に関しては、基板表面のうねりを抑えて平坦度を向上させたり、同一半径上におけるうねりを抑えると共に基板の内外径の寸法精度を向上させたりすることに依然として課題が残されている。
【０００７】
そこで、本発明は、金型の温度を良好に制御し得る低コストかつ高精度なプレス成形の実現を目的とする。
【０００８】
【課題を解決するための手段】
本発明の一形態は、金型間の原材料を加熱・加圧することにより所望の成形品をつくり出すプレス成形装置であり、この装置は、金型の周囲に配置された第１の誘導コイルと、金型の周囲に配置された第２の誘導コイルと、第１の誘導コイルに第１の高周波電流を供給する第１の高周波電源と、第２の誘導コイルに第１の高周波電流とは異なる周波数をもった第２の高周波電流を供給する第２の高周波電源とを備えることを特徴とする。
【０００９】
このプレス成形装置は、高周波誘導加熱方式により金型および原材料を加熱可能なものである。そして、このプレス成形装置では、金型の周囲に、第１の誘導コイルが配置されると共に、金型の軸方向等において第１の誘導コイルとは異なる位置に第２の誘導コイルが配置される。そして、第１の誘導コイルには、第１の高周波電源から所定の周波数をもった第１の高周波電流が供給され、第２の誘導コイルには、第２の高周波電源から第１の高周波電流とは異なる周波数をもった第２の高周波電流が供給される。
【００１０】
このように、このプレス成形装置では、第１の誘導コイルに供給される第１の高周波電流と第２の誘導コイルに供給される第２の高周波電流との周波数が異なっている。従って、第１の誘導コイルにより形成される磁場と第２の誘導コイルによって形成される磁場とが互いに干渉し合うことを確実に抑制することができる。この結果、金型の周囲において、第１の誘導コイルと第２の誘導コイルとを適切な位置に自在に配置することができる。また、第１の高周波電源と第２の高周波電源とは互いに独立しており、それぞれの制御は低コストかつ単純に実行され得るので、第１の誘導コイルによる加熱量と第２の誘導コイルによる加熱量とを個別かつ高精度に調節することができる。この結果、このプレス成形装置によれば、金型の温度を極めて良好かつ柔軟に制御可能となり、歪みや反りが抑制されて高い寸法精度、平坦度および平滑度等を有する成形品を低コストで製造することができる。
【００１１】
また、金型は、固定型および可動型を含み、第１の誘導コイルは、固定型の外周面を概ね囲むように配置される一方、第２の誘導コイルは、可動型の外周面を概ね囲むように配置されていると好ましい。このような構成を採用すれば、固定型および可動型の温度を極めて良好かつ柔軟に制御可能となり、低コストで高精度なプレス成形を実現することができる。
【００１２】
更に、第１の誘導コイルと第２の誘導コイルとの間には、第１の誘導コイルによる磁場と第２の誘導コイルによる磁場との干渉を防止するためのシールド部材が配置されていると好ましい。このような構成を採用すれば、第１の高周波電流の周波数と第２の高周波電流の周波数とが比較的近い場合であっても、第１の誘導コイルにより形成される磁場と第２の誘導コイルによって形成される磁場とが互いに干渉し合うことを確実に抑制することができるので、実用上極めて良好な結果が得られる。
【００１３】
また、金型は、固定型および可動型を含み、第１の誘導コイルは、固定型および可動型の双方を加熱することができるように配置される一方、第２の誘導コイルは、固定型と可動型との間に生じた温度差を補正することができるように配置されていると好ましい。
【００１４】
このような構成のもとでは、例えば、第１の誘導コイル（メインコイル）が、固定型および可動型の何れか一方を主に加熱するように、固定型および可動型の双方の周囲に配置され、第２の誘導コイル（サブコイル）が、固定型および可動型の他方を主に加熱するように配置される。このような構成を採用しても、金型の温度を極めて良好かつ柔軟に制御可能となり、歪みや反りが抑制されて高い寸法精度、平坦度および平滑度等を有する成形品を低コストで製造することができる。
【００１５】
本発明の他の形態は、金型間の原材料を加熱・加圧することにより所望の成形品をつくり出すプレス成形方法であり、この方法は、金型の周囲に第１の誘導コイルを配置すると共に、金型の周囲に更に第２の誘導コイルを配置し、第１の誘導コイルに第１の高周波電流を供給する一方、第２の誘導コイルに第１の高周波電流とは異なる周波数をもった第２の高周波電流を供給して、金型および原材料を加熱することを特徴とする。
【００１６】
【発明の実施の形態】
以下、図面と共に本発明によるプレス成形装置およびプレス成形方法の好適な実施形態について詳細に説明する。
【００１７】
〔第１実施形態〕
図１は、本発明によるプレス成形装置の第１実施形態を示す概略構成図である。同図に示されるプレス成形装置１は、ガラスやプラスチック等の原材料Ｇから磁気ディスク用の基板をつくり出すために用いると好適なものであり、金型および原材料Ｇを加熱する方式として高周波誘導方式を採用するものである。プレス成形装置１は、ベース３、上ステージ４および下ステージ５を含むフレーム２を有する。上ステージ４は、複数の支柱６によってベース３上に固定されている。また、下ステージ５は、複数の支柱６によって摺動自在に支持されており、ベース３上に設置されたプレスユニット７のロッド７ａに接続されている。プレスユニット７を作動させることにより、下ステージ５をベース３と上ステージ４との間で図中上下方向に移動させることができる。
【００１８】
上ステージ４には、支持部材８を介して、導電性材料（ＷＣ材等）からなる上型（固定型）１１が取り付けられる。一方、下ステージ５には、支持部材９を介して、導電性材料（ＷＣ材等）からなる下型（可動型）１２が取り付けられ、下型１２には規制リング１４が装着される。また、上型１１に対しては、上型温度センサ１５が設けられており、下型１２に対しては、下型温度センサ１６が設けられている。更に、上ステージ４と上型１１との間、および、下ステージ５と下型１２との間には、冷却ジャケット（冷却手段）１７，１８が配置されている。各冷却ジャケット１７および１８には、図１において白抜矢印で示されるように冷却媒体を循環させることができる。各冷却ジャケット１７，１８は、図示されない移動機構によって、上型１１の裏面（転写面と反対側の面）または下型１２の裏面（転写面と反対側の面）に対して接近離間され得る。
【００１９】
さて、このプレス成形装置１では、上型１１および下型１２と原材料Ｇとを加熱するために高周波誘導加熱方式が採用されていることから、上型１１および下型１２の周囲には、第１誘導コイル２１および第２誘導コイル２２が配置されている。第１誘導コイル２１は、上型（固定型）１１の外周面を概ね囲むようにフレーム２に対して固定されている。一方、第２誘導コイル２２は、第１誘導コイル２１とは完全に独立しており、下型１２の移動範囲（少なくとも、原材料Ｇが上型１１の成形面と接触する位置よりも上の範囲）内において、下型１２の外周面を概ね囲むようにフレーム２に対して固定されている。本実施形態では、第１誘導コイル２１と第２誘導コイル２２とは、概ねの同一の内径を有し、下型１２の移動方向（金型の軸方向）において概ね同軸に隣り合うように配置されている。
【００２０】
図１に示されるように、第１誘導コイル２１は、第１高周波電源２３に接続されており、この第１高周波電源２３から所定周波数をもった第１の高周波電流（交番電流）の供給を受ける。第１高周波電源２３には、第１温度調節器２５が接続されている。第１温度調節器２５は、上述の上型温度センサ１５と接続されており、上型温度センサ１５の検出値に基づいて、上型１１の温度が各成形工程において要求される温度と一致するように第１高周波電源２３の出力を制御する。
【００２１】
一方、第２誘導コイル２２は、第２高周波電源２４に接続されており、この第２高周波電源２４から第１の高周波電流とは異なる周波数をもった第２の高周波電流（交番電流）の供給を受ける。第２高周波電源２４には、第２温度調節器２６が接続されている。第２温度調節器２６は、上述の下型温度センサ１６と接続されており、下型温度センサ１６の検出値に基づいて、下型１２の温度が各成形工程において要求される温度と一致するように第２高周波電源２４の出力を制御する。
【００２２】
ここで、プレス成形装置１では、第１誘導コイル２１に供給される第１の高周波電流と、第２誘導コイル２２に供給される第２の高周波電流との周波数が異なっている。従って、第１誘導コイル２１により形成される磁場と第２誘導コイル２２によって形成される磁場とが互いに干渉し合うことが確実に抑制される。この結果、上型１１および下型１２の周囲において、第１誘導コイル２１と第２誘導コイル２２とを適切な位置に自在に配置することができる。なお、プレス成形装置１では、上型１１、下型１２、第１誘導コイル２１および第２誘導コイル２２等が図示されない収容部材内に収容されており、収容部材の内部は、真空または不活性ガス雰囲気にされ得る。
【００２３】
次に、上述のプレス成形装置１の動作について説明する。まず、上型１１と下型１２とが完全に開かれた状態で、図示されない移載ユニットによって収容部材内の下型１２のほぼ中央に原材料Ｇが配置される。原材料Ｇが下型１２に配置されると、プレスユニット７が作動され、原材料Ｇの上部が上型１１の成形面に接触するまで、下型１２が上型１１に接近させられる。そして、上型１１、下型１２、第１誘導コイル２１および第２誘導コイル２２等が高温下で酸化により劣化することを防止すべく、これらの部材が収容されている収容部材の内部は真空または不活性ガス雰囲気にされる。
【００２４】
上型１１および下型１２の周辺が真空または不活性ガス雰囲気になされると、高周波誘導加熱による上型１１および下型１２の加熱が行われ（加熱工程）、原材料Ｇは、上型１１および下型１２を介して所定の軟化温度（プレス温度）まで昇温させられる。原材料Ｇが軟化温度まで昇温すると、プレスユニット７によって下型１２が上型１１へと更に接近させられ、これにより、上型１１と下型１２との間の原材料Ｇが加圧される（プレス工程）。下型１２の上昇動作は、規制リングの上端が上型１１に当接した段階で停止され、これにより、厚さが一定に揃えられた成形品を得ることが可能となる。
【００２５】
加熱工程およびプレス工程の間、第１誘導コイル２１には、第１高周波電源２３から所定の周波数をもった第１の高周波電流が供給され、第２誘導コイル２２には、第２高周波電源２４から第１の高周波電流とは異なる周波数をもった第２の高周波電流が供給される。ここで、上述のように、第１高周波電源２３と第２高周波電源２４とは互いに独立しており、それぞれの制御は、上型温度センサ１５と下型温度センサ１６との検出値に応じて、低コストかつ単純に構成される第１および第２温度調節器２５，２６により実行される。
【００２６】
従って、プレス成形装置１では、第１誘導コイル２１による加熱量と第２誘導コイル２２による加熱量とが個別かつ高精度に調節されることになる。この結果、プレス成形装置１では、上型１１と下型１２との温度差を常時ほぼゼロに維持可能となり、歪みや反りが抑制されて高い寸法精度、平坦度および平滑度等を有する成形品、特に、外径と板厚との比が大きいディスク用の基板を低コストで製造することができる。加圧完了後、上型１１の裏面には冷却ジャケット１７が、下型１２の裏面には冷却ジャケット１８がそれぞれ押し当てられ（冷却工程）、型内の成形品が冷却される。そして、冷却完了後、下型１２が下降させられて金型が開かれ、成形品が取り出される。
【００２７】
なお、第１誘導コイル２１に供給される第１高周波電流の周波数および第２誘導コイル２２に供給される第２高周波電流の周波数としては、上型１１および下型１２の構成材料の電気伝導度および透磁率に応じて任意選択可能である。ただし、第１誘導コイル２１と第２誘導コイル２２とが比較的近接し合う場合には、第１高周波電流の周波数と、第２高周波電流の周波数とは、一方が他方の４倍程度となっているのが好ましい。また、第１の高周波電流の周波数と第２の高周波電流の周波数とが比較的近くなる場合には、図１に示されるように、第１誘導コイル２１と第２誘導コイル２２との間に、磁場同士の相互干渉を防止する磁気シールド部材２７を配置すると好ましい。これにより、実用上極めて良好な結果を得ることができる。
【００２８】
〔第２実施形態〕
以下、図２から図４を参照しながら、本発明によるプレス成形装置の第２実施形態について説明する。なお、上述の第１実施形態に関連して説明されたものと同一の要素については同一の符号が付され、重複する説明は省略される。
【００２９】
図２に示されるプレス成形装置１Ａも、第１実施形態のプレス成形装置１と同様に、それぞれ独立の第１誘導コイル２１Ａおよび第２誘導コイル２２Ａを有する。この場合、第１誘導コイル２１Ａは、上型１１および下型１２の双方の周囲に位置し得るサイズを有すると共に可動型である下型１２を主に加熱するように配置され、メインコイルとして機能する。一方、第２誘導コイル２２Ａは、固定型である上型１１を主に加熱するように配置され、サブコイルとして機能する。
【００３０】
すなわち、本実施形態において、第１誘導コイル２１Ａは、原材料Ｇが上型１１の成形面と接触した状態となっている際に、上型１１の外周面と下型１２の外周面との双方を囲むように配置されている。そして、第１誘導コイル２１Ａは、上型１１よりも下型１２に対して高い加熱効率を発するように、下型１２側（図２における下方）に若干シフトされた状態でフレーム２に対して固定されている。第１誘導コイル２１Ａには、第１高周波電源２３Ａから所定の周波数をもった第１高周波電流が供給される。第１高周波電源２３Ａは、下型温度センサ１６と接続された第１温度調節器２５Ａによって制御される。
【００３１】
一方、第２誘導コイル２２Ａは、第１誘導コイル２１Ａよりも少ない巻線数を有するか、あるいは、第１誘導コイル２１Ａよりもコイルピッチが粗く、第１誘導コイル２１Ａよりも加熱能力が小さい。また、第２誘導コイル２２Ａは、第１誘導コイル２１Ａよりも大きな内径を有しており、固定型である上型１１の外周面に対応する位置において、第１誘導コイル２１Ａを同軸に囲むようにフレーム２に対して固定されている。第２誘導コイル２２Ａには、第２高周波電源２４Ａから第１高周波電流とは異なる周波数をもった第２高周波電流が供給される。第２高周波電源２４Ａは、上型温度センサ１５および下型温度センサ１６の双方と接続された第２温度調節器２６ＡによってＰＩＤ制御される。
【００３２】
このように構成されるプレス成形装置１Ａでは、加熱工程およびプレス工程の間、第１温度調節器２５Ａが、下型温度センサ１６の検出値に基づいて下型１２の温度と各成形工程において要求される温度とが一致するように第１高周波電源２３Ａの出力を制御する。ここで、第１誘導コイル２１Ａは、主として下型（可動型）１２を加熱するためのものであることから、第１誘導コイル２１Ａにのみ高周波電流が供給されるのであれば、下型１２に比べて、上型１１の昇温が遅れてしまうことになる。
【００３３】
これを補うべく、加熱工程およびプレス工程の間、第２温度調節器２６Ａには、上型温度センサ１５および下型温度センサ１６の検出値が入力される。そして、第２温度調節器２６Ａは、上型温度センサ１５および下型温度センサ１６の検出値に基づいて、上型１１と下型１２との温度差を求め、求めた温度差がゼロになるように第２高周波電源２４Ａの出力を制御（ＰＩＤ制御）する。これにより、上型１１および下型１２の温度は、所望の値に極めて良好かつ柔軟に制御され、両者の温度差は常時ほぼゼロに維持されることになる。この結果、プレス成形装置１Ａによっても、歪みや反りが抑制されて寸法精度、平坦度および平滑度等を有する成形品、特に、外径と板厚との比が大きいディスク用の基板を低コストで製造することができる。
【００３４】
なお、本実施形態は、メインコイルとなる第１誘導コイル２１Ａが主として下型１２（可動型）を加熱し、サブコイルとなる第２誘導コイル２２Ａが主として上型１１（固定型）を加熱するものとして説明されたが、これに限られるものではない。すなわち、メインコイルとなる第１誘導コイル２１Ａが主として上型１１（固定型）を加熱し、サブコイルとなる第２誘導コイル２２Ａが主として下型１２（可動型）を加熱するように構成することも可能である。また、サブコイルとなる第２誘導コイル２２Ａをメインコイルとなる第１誘導コイル２１Ａの内側に配置してもよい。
【００３５】
更に、図３に示されるように、メインコイルとなる第１誘導コイル２１Ａが可動型である下型１２（あるいは上型１１）の移動範囲をカバーする一方、サブコイルとなる第２誘導コイル２２Ａのみが固定型である上型１１（あるいは下型１２）の外周面を囲むように構成してもよい。また、図４に示されるように、比較的粗いコイルピッチを有する第１誘導コイル（メインコイル）２１Ａを上型１１および／または下型１２の周囲における所望位置に配置すると共に、第２誘導コイル（サブコイル）２２Ａを構成する導体を所定位置において第１誘導コイル２１Ａに対して巻回することにより、第１誘導コイル２１Ａと第２誘導コイルとを二重らせん状に配置してもよい。なお、図４に示される誘導コイルの構成は、第１実施形態のプレス成形装置１に対して適用されてもよい。
【００３６】
【発明の効果】
以上説明されたように、本発明によれば、金型の温度を極めて良好かつ柔軟に制御可能となり、歪みや反りが抑制されて高い寸法精度、平坦度および平滑度等を有する成形品を低コストで製造することができる。
【図面の簡単な説明】
【図１】本発明によるプレス成形装置の第１実施形態を示す概略構成図である。
【図２】本発明によるプレス成形装置の第２実施形態を示す概略構成図である。
【図３】誘導コイルの他の配置例を示す模式図である。
【図４】誘導コイルの更に他の配置例を示す模式図である。
【符号の説明】
１，１Ａ プレス成形装置
４ 上ステージ
５ 下ステージ
７ プレスユニット
１１ 上型
１２ 上型
１５ 上型温度センサ
１６ 下型温度センサ
２１，２１Ａ 第１誘導コイル
２２，２２Ａ 誘導コイル
２３，２３Ａ 第１高周波電源
２４，２４Ａ 第２高周波電源
２５，２５Ａ 第１温度調節器
２６，２６Ａ 第２温度調節器
２７ 磁気シールド部材
Ｇ 原材料[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a press molding apparatus and a press molding method, and more particularly, to a press molding apparatus and a press molding method suitable for manufacturing a glass substrate or the like applied to a magnetic disk or the like.
[0002]
[Prior art]
Conventionally, magnetic disks including substrates made of raw materials such as glass and plastic have been widely used. Since such a magnetic disk substrate is required to have a very smooth surface, it is initially manufactured by cutting a glass material or the like into a predetermined size and polishing the surface smoothly. It was. However, the method of manufacturing the substrate for the disk one by one in this way requires a large number of steps and labor, and has a big problem in reducing the manufacturing cost of the substrate. For this reason, in recent years, when a substrate is manufactured, a press molding method is employed in which a raw material such as glass is heated and pressurized in a mold to transfer a desired shape to the raw material with high accuracy. It has become to.
[0003]
Such a press molding method is generally performed according to the following procedure. First, a glass material or the like as a raw material is disposed between the upper and lower molds (between the fixed mold and the movable mold), and the periphery of the mold or the like is set to a vacuum or an inert gas atmosphere. Further, the mold and the raw material are heated by a predetermined heat source, and when the mold and the raw material reach a predetermined temperature, the raw material is pressurized between the molds. And after pressurization completion, a molded article is cooled and taken out from a metal mold | die. According to such a press molding method, post-processing for the molded product is not required, and high-quality substrates can be mass-produced at low cost.
[0004]
Here, when high processing accuracy is required as in the formation of a disk substrate, temperature control of the mold is extremely important. For this reason, a high frequency induction heating method with good temperature controllability is often adopted as a heating method for the mold and raw materials. In a press molding apparatus that employs a high-frequency induction heating method, an induction coil connected to a high-frequency power source is disposed around a conductive mold. When a high frequency current (alternating current) is supplied to the induction coil, a magnetic field is formed around the mold, an eddy current flows through the mold, and the mold itself generates heat due to the current loss. According to such a high-frequency induction heating method, it is possible to efficiently heat a metal mold or the like to be heated by being contacted, and it is also possible to reduce the heat saving capacity of the heated object and to clean the equipment.
[0005]
[Problems to be solved by the invention]
However, when press-molding a substrate for a disk whose ratio between the outer diameter and the plate thickness is finally increased, a relatively thick spherical or marble raw material is used as the raw material. The amount of movement must be increased to some extent. For this reason, even if the high frequency induction heating method is adopted, the relative positional relationship between the induction coil and the mold (particularly the movable mold) varies, and the heat input state for the two molds changes. The change in the heat input state of each mold causes a temperature difference between the two molds, thereby preventing the execution of high-precision press molding.
[0006]
In order to solve such a problem, for example, it is conceivable to move the induction coil in the axial direction of the mold, or to change the winding pitch of the coil in the axial direction of the mold. However, even if these methods are employed, it is difficult to control the temperature of each mold so as to follow the movement of the mold satisfactorily. In JP-A-6-64932, two induction coils are arranged around a fixed type and a movable type, and the oscillation frequency of one high frequency power source is controlled to control the high frequency current to each induction coil. A technique for suppressing the temperature difference between the molds by changing the amount is disclosed. However, it is not easy to freely change the amount of high-frequency current to each induction coil by such a technique, even if an extremely complicated and expensive control circuit is used. It is virtually impossible to control to follow the mold clamping well. As a result, with respect to press molding of disk substrates, etc., it is still possible to improve the flatness by suppressing the undulation of the substrate surface, or to suppress the undulation on the same radius and improve the dimensional accuracy of the inner and outer diameters of the substrate. Challenges remain.
[0007]
Accordingly, an object of the present invention is to realize low-cost and high-precision press molding that can favorably control the temperature of a mold.
[0008]
[Means for Solving the Problems]
One aspect of the present invention is a press molding apparatus for producing a desired molded product by heating and pressurizing raw materials between molds, and the apparatus includes a first induction coil disposed around a mold, The second induction coil disposed around the mold, the first high-frequency power source that supplies the first high-frequency current to the first induction coil, and the first high-frequency current different from the first induction coil And a second high-frequency power source for supplying a second high-frequency current having a frequency.
[0009]
This press molding apparatus can heat a mold and raw materials by a high frequency induction heating method. In this press molding apparatus, the first induction coil is disposed around the mold, and the second induction coil is disposed at a position different from the first induction coil in the axial direction of the mold. The The first induction coil is supplied with a first high-frequency current having a predetermined frequency from the first high-frequency power source, and the second induction coil is supplied with the first high-frequency current from the second high-frequency power source. A second high-frequency current having a frequency different from the above is supplied.
[0010]
Thus, in this press molding apparatus, the frequencies of the first high-frequency current supplied to the first induction coil and the second high-frequency current supplied to the second induction coil are different. Therefore, it is possible to reliably suppress the magnetic field formed by the first induction coil and the magnetic field formed by the second induction coil from interfering with each other. As a result, the first induction coil and the second induction coil can be freely arranged at appropriate positions around the mold. Further, the first high-frequency power source and the second high-frequency power source are independent from each other, and each control can be executed at low cost and simply, so that the heating amount by the first induction coil and the second induction coil are The amount of heating can be adjusted individually and with high accuracy. As a result, according to this press molding apparatus, the temperature of the mold can be controlled very well and flexibly, and a molded product having high dimensional accuracy, flatness, smoothness, etc. with reduced distortion and warpage can be produced at low cost. Can be manufactured.
[0011]
The mold includes a fixed mold and a movable mold, and the first induction coil is disposed so as to substantially surround the outer peripheral surface of the fixed mold, while the second induction coil substantially includes the outer peripheral surface of the movable mold. It is preferable to arrange so as to surround. By adopting such a configuration, it becomes possible to control the temperature of the fixed mold and the movable mold extremely well and flexibly, and it is possible to realize press molding with high accuracy at low cost.
[0012]
Further, a shield member for preventing interference between the magnetic field generated by the first induction coil and the magnetic field generated by the second induction coil is disposed between the first induction coil and the second induction coil. preferable. If such a configuration is adopted, even if the frequency of the first high-frequency current and the frequency of the second high-frequency current are relatively close, the magnetic field formed by the first induction coil and the second induction Since it is possible to reliably prevent the magnetic field formed by the coil from interfering with each other, extremely good results can be obtained in practical use.
[0013]
The mold includes a fixed mold and a movable mold, and the first induction coil is arranged so that both the fixed mold and the movable mold can be heated, while the second induction coil is a fixed mold. It is preferable to arrange so that the temperature difference generated between the movable mold and the movable mold can be corrected.
[0014]
Under such a configuration, for example, the first induction coil (main coil) is arranged around both the fixed type and the movable type so as to mainly heat either the fixed type or the movable type. The second induction coil (subcoil) is arranged so as to mainly heat the other of the fixed type and the movable type. Even if such a configuration is adopted, the mold temperature can be controlled very well and flexibly, and a molded product having high dimensional accuracy, flatness, smoothness, etc. with low distortion and warpage can be manufactured at low cost. can do.
[0015]
Another embodiment of the present invention is a press molding method for producing a desired molded product by heating and pressurizing raw materials between molds, and this method includes arranging a first induction coil around the mold. The second induction coil is further arranged around the mold to supply the first induction coil with the first high frequency current, while the second induction coil has a frequency different from the first high frequency current. A second high-frequency current is supplied to heat the mold and the raw material.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a press molding apparatus and a press molding method according to the present invention will be described in detail with reference to the drawings.
[0017]
[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a first embodiment of a press forming apparatus according to the present invention. The press molding apparatus 1 shown in the figure is suitable for use in producing a substrate for a magnetic disk from a raw material G such as glass or plastic. A high frequency induction method is used as a method for heating the mold and the raw material G. Adopted. The press molding apparatus 1 has a frame 2 including a base 3, an upper stage 4 and a lower stage 5. The upper stage 4 is fixed on the base 3 by a plurality of columns 6. The lower stage 5 is slidably supported by a plurality of support columns 6 and is connected to a rod 7 a of a press unit 7 installed on the base 3. By operating the press unit 7, the lower stage 5 can be moved between the base 3 and the upper stage 4 in the vertical direction in the figure.
[0018]
An upper mold (fixed mold) 11 made of a conductive material (WC material or the like) is attached to the upper stage 4 via a support member 8. On the other hand, a lower mold (movable mold) 12 made of a conductive material (WC material or the like) is attached to the lower stage 5 via a support member 9, and a regulating ring 14 is attached to the lower mold 12. An upper mold temperature sensor 15 is provided for the upper mold 11, and a lower mold temperature sensor 16 is provided for the lower mold 12. Further, cooling jackets (cooling means) 17 and 18 are disposed between the upper stage 4 and the upper mold 11 and between the lower stage 5 and the lower mold 12. A cooling medium can be circulated in each of the cooling jackets 17 and 18 as indicated by white arrows in FIG. Each of the cooling jackets 17 and 18 can be moved closer to and away from the back surface of the upper mold 11 (surface opposite to the transfer surface) or the back surface of the lower mold 12 (surface opposite to the transfer surface) by a moving mechanism (not shown). .
[0019]
In the press molding apparatus 1, since the high-frequency induction heating method is used to heat the upper mold 11 and the lower mold 12 and the raw material G, the upper mold 11 and the lower mold 12 are surrounded by the first mold 11. A first induction coil 21 and a second induction coil 22 are arranged. The first induction coil 21 is fixed to the frame 2 so as to substantially surround the outer peripheral surface of the upper mold (fixed mold) 11. On the other hand, the second induction coil 22 is completely independent of the first induction coil 21, and the movement range of the lower mold 12 (at least the range above the position where the raw material G contacts the molding surface of the upper mold 11). ) Is fixed to the frame 2 so as to substantially surround the outer peripheral surface of the lower mold 12. In the present embodiment, the first induction coil 21 and the second induction coil 22 have substantially the same inner diameter and are arranged so as to be substantially coaxially adjacent in the moving direction of the lower mold 12 (the axial direction of the mold). Has been.
[0020]
As shown in FIG. 1, the first induction coil 21 is connected to a first high-frequency power source 23, and supplies a first high-frequency current (alternating current) having a predetermined frequency from the first high-frequency power source 23. receive. A first temperature controller 25 is connected to the first high frequency power supply 23. The first temperature controller 25 is connected to the above-described upper mold temperature sensor 15, and the temperature of the upper mold 11 matches the temperature required in each molding process based on the detection value of the upper mold temperature sensor 15. In this manner, the output of the first high frequency power supply 23 is controlled.
[0021]
On the other hand, the second induction coil 22 is connected to a second high frequency power supply 24, and the second high frequency power supply 24 supplies a second high frequency current (alternating current) having a frequency different from the first high frequency current. Receive. A second temperature regulator 26 is connected to the second high frequency power supply 24. The second temperature controller 26 is connected to the above-described lower mold temperature sensor 16, and the temperature of the lower mold 12 matches the temperature required in each molding step based on the detection value of the lower mold temperature sensor 16. In this manner, the output of the second high frequency power supply 24 is controlled.
[0022]
Here, in the press molding apparatus 1, the frequencies of the first high-frequency current supplied to the first induction coil 21 and the second high-frequency current supplied to the second induction coil 22 are different. Therefore, the magnetic field formed by the first induction coil 21 and the magnetic field formed by the second induction coil 22 are reliably suppressed from interfering with each other. As a result, the first induction coil 21 and the second induction coil 22 can be freely arranged at appropriate positions around the upper mold 11 and the lower mold 12. In the press molding apparatus 1, the upper die 11, the lower die 12, the first induction coil 21, the second induction coil 22, and the like are accommodated in a housing member (not shown), and the inside of the housing member is vacuum or inert. It can be a gas atmosphere.
[0023]
Next, operation | movement of the above-mentioned press molding apparatus 1 is demonstrated. First, in a state where the upper mold 11 and the lower mold 12 are completely opened, the raw material G is arranged at the approximate center of the lower mold 12 in the housing member by a transfer unit (not shown). When the raw material G is disposed on the lower mold 12, the press unit 7 is operated, and the lower mold 12 is brought close to the upper mold 11 until the upper part of the raw material G contacts the molding surface of the upper mold 11. In order to prevent the upper die 11, the lower die 12, the first induction coil 21, the second induction coil 22, and the like from being deteriorated by oxidation at high temperatures, the inside of the accommodation member in which these members are contained is vacuumed. Alternatively, an inert gas atmosphere is used.
[0024]
When the periphery of the upper mold 11 and the lower mold 12 is in a vacuum or an inert gas atmosphere, the upper mold 11 and the lower mold 12 are heated by high-frequency induction heating (heating process). The temperature is raised to a predetermined softening temperature (press temperature) through the lower mold 12. When the temperature of the raw material G is increased to the softening temperature, the lower die 12 is further brought closer to the upper die 11 by the press unit 7, whereby the raw material G between the upper die 11 and the lower die 12 is pressurized ( Pressing process). The ascending operation of the lower mold 12 is stopped when the upper end of the regulating ring comes into contact with the upper mold 11, thereby making it possible to obtain a molded product having a uniform thickness.
[0025]
During the heating step and the pressing step, the first induction coil 21 is supplied with a first high-frequency current having a predetermined frequency from the first high-frequency power source 23, and the second induction coil 22 is supplied with a second high-frequency power source 24. To a second high-frequency current having a frequency different from that of the first high-frequency current. Here, as described above, the first high-frequency power source 23 and the second high-frequency power source 24 are independent from each other, and each control is performed according to the detection values of the upper mold temperature sensor 15 and the lower mold temperature sensor 16. The first and second temperature regulators 25 and 26 are implemented at low cost and simply.
[0026]
Therefore, in the press molding apparatus 1, the heating amount by the first induction coil 21 and the heating amount by the second induction coil 22 are adjusted individually and with high accuracy. As a result, in the press molding apparatus 1, the temperature difference between the upper mold 11 and the lower mold 12 can be maintained at almost zero at all times, and a molded product having high dimensional accuracy, flatness, smoothness, etc., with suppressed distortion and warpage. In particular, a disk substrate having a large ratio between the outer diameter and the plate thickness can be manufactured at low cost. After the pressurization is completed, the cooling jacket 17 is pressed against the back surface of the upper mold 11 and the cooling jacket 18 is pressed against the back surface of the lower mold 12 (cooling step), and the molded product in the mold is cooled. Then, after the cooling is completed, the lower mold 12 is lowered, the mold is opened, and the molded product is taken out.
[0027]
The frequency of the first high-frequency current supplied to the first induction coil 21 and the frequency of the second high-frequency current supplied to the second induction coil 22 are the electrical conductivities of the constituent materials of the upper mold 11 and the lower mold 12. And can be arbitrarily selected according to the magnetic permeability. However, when the first induction coil 21 and the second induction coil 22 are relatively close to each other, one of the frequency of the first high-frequency current and the frequency of the second high-frequency current is about four times that of the other. It is preferable. When the frequency of the first high-frequency current and the frequency of the second high-frequency current are relatively close, as shown in FIG. 1, the first high-frequency current is between the first induction coil 21 and the second induction coil 22. It is preferable to arrange a magnetic shield member 27 that prevents mutual interference between magnetic fields. Thereby, a very good result can be obtained practically.
[0028]
[Second Embodiment]
Hereinafter, a second embodiment of the press molding apparatus according to the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same element as what was demonstrated in relation to the above-mentioned 1st Embodiment, and the overlapping description is abbreviate | omitted.
[0029]
The press molding apparatus 1A shown in FIG. 2 also has independent first induction coils 21A and second induction coils 22A, as with the press molding apparatus 1 of the first embodiment. In this case, the first induction coil 21A has a size that can be located around both the upper mold 11 and the lower mold 12 and is arranged so as to mainly heat the lower mold 12 that is movable, and functions as a main coil. To do. On the other hand, the second induction coil 22A is disposed so as to mainly heat the upper mold 11 which is a fixed mold, and functions as a sub-coil.
[0030]
That is, in the present embodiment, the first induction coil 21 </ b> A has both the outer peripheral surface of the upper die 11 and the outer peripheral surface of the lower die 12 when the raw material G is in contact with the molding surface of the upper die 11. It is arranged to surround. The first induction coil 21A is slightly shifted to the lower mold 12 side (downward in FIG. 2) with respect to the frame 2 so as to emit higher heating efficiency to the lower mold 12 than to the upper mold 11. It is fixed. The first induction coil 21A is supplied with a first high-frequency current having a predetermined frequency from the first high-frequency power source 23A. The first high frequency power supply 23 </ b> A is controlled by a first temperature regulator 25 </ b> A connected to the lower mold temperature sensor 16.
[0031]
On the other hand, the second induction coil 22A has a smaller number of windings than the first induction coil 21A, or the coil pitch is coarser than the first induction coil 21A, and the heating capacity is smaller than that of the first induction coil 21A. Further, the second induction coil 22A has a larger inner diameter than the first induction coil 21A, and surrounds the first induction coil 21A coaxially at a position corresponding to the outer peripheral surface of the fixed upper mold 11. The frame 2 is fixed to the frame 2. The second induction coil 22A is supplied with a second high frequency current having a frequency different from the first high frequency current from the second high frequency power supply 24A. The second high frequency power supply 24A is PID controlled by a second temperature regulator 26A connected to both the upper mold temperature sensor 15 and the lower mold temperature sensor 16.
[0032]
In the press molding apparatus 1A configured as described above, during the heating process and the pressing process, the first temperature controller 25A requires the temperature of the lower mold 12 and the molding process based on the detection value of the lower mold temperature sensor 16. The output of the first high-frequency power source 23A is controlled so that the temperature to be matched matches. Here, since the first induction coil 21A is mainly for heating the lower die (movable type) 12, if a high-frequency current is supplied only to the first induction coil 21A, In comparison, the temperature rise of the upper mold 11 is delayed.
[0033]
In order to compensate for this, detection values of the upper mold temperature sensor 15 and the lower mold temperature sensor 16 are input to the second temperature controller 26A during the heating process and the pressing process. Then, the second temperature controller 26A obtains the temperature difference between the upper die 11 and the lower die 12 based on the detection values of the upper die temperature sensor 15 and the lower die temperature sensor 16, and the obtained temperature difference becomes zero. In this manner, the output of the second high frequency power supply 24A is controlled (PID control). Thereby, the temperature of the upper mold | type 11 and the lower mold | type 12 is controlled very favorably and flexibly to the desired value, and the temperature difference of both is always maintained at substantially zero. As a result, even with the press molding apparatus 1A, distortion and warpage are suppressed, and a molded product having dimensional accuracy, flatness, smoothness, etc., in particular, a disk substrate having a large ratio of the outer diameter to the plate thickness is low cost. Can be manufactured.
[0034]
In this embodiment, the first induction coil 21A serving as a main coil mainly heats the lower mold 12 (movable type), and the second induction coil 22A serving as a sub-coil mainly heats the upper mold 11 (fixed type). However, the present invention is not limited to this. That is, the first induction coil 21A serving as the main coil mainly heats the upper mold 11 (fixed type), and the second induction coil 22A serving as the sub coil mainly heats the lower mold 12 (movable type). Is possible. Further, the second induction coil 22A serving as a subcoil may be disposed inside the first induction coil 21A serving as a main coil.
[0035]
Further, as shown in FIG. 3, the first induction coil 21A as the main coil covers the moving range of the lower mold 12 (or the upper mold 11) which is a movable type, while only the second induction coil 22A as a subcoil. May be configured to surround the outer peripheral surface of the upper mold 11 (or the lower mold 12) which is a fixed mold. Further, as shown in FIG. 4, the first induction coil (main coil) 21A having a relatively coarse coil pitch is arranged at a desired position around the upper die 11 and / or the lower die 12, and the second induction coil. (Subcoil) The first induction coil 21A and the second induction coil may be arranged in a double spiral by winding a conductor constituting the 22A around the first induction coil 21A at a predetermined position. In addition, the structure of the induction coil shown by FIG. 4 may be applied with respect to the press molding apparatus 1 of 1st Embodiment.
[0036]
【The invention's effect】
As described above, according to the present invention, the temperature of the mold can be controlled extremely well and flexibly, and a molded product having high dimensional accuracy, flatness, smoothness, etc. can be reduced by suppressing distortion and warpage. Can be manufactured at cost.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of a press molding apparatus according to the present invention.
FIG. 2 is a schematic configuration diagram showing a second embodiment of a press molding apparatus according to the present invention.
FIG. 3 is a schematic diagram showing another arrangement example of the induction coil.
FIG. 4 is a schematic diagram showing still another arrangement example of the induction coil.
[Explanation of symbols]
1, 1A Press forming apparatus 4 Upper stage 5 Lower stage 7 Press unit 11 Upper mold 12 Upper mold 15 Upper mold temperature sensor 16 Lower mold temperature sensors 21, 21A First induction coils 22, 22A Induction coils 23, 23A First high frequency power supply 24, 24A Second high frequency power supply 25, 25A First temperature controller 26, 26A Second temperature controller 27 Magnetic shield member G Raw material

Claims (5)

金型間の原材料を加熱・加圧することにより所望の成形品をつくり出すプレス成形装置において、
前記金型の周囲に配置された第１の誘導コイルと、
前記金型の周囲に配置された第２の誘導コイルと、
前記第１の誘導コイルに第１の高周波電流を供給する第１の高周波電源と、
前記第２の誘導コイルに前記第１の高周波電流とは異なる周波数をもった第２の高周波電流を供給する第２の高周波電源とを備えることを特徴とするプレス成形装置。In press molding equipment that produces desired molded products by heating and pressurizing raw materials between molds,
A first induction coil disposed around the mold;
A second induction coil disposed around the mold;
A first high frequency power supply for supplying a first high frequency current to the first induction coil;
A press molding apparatus, comprising: a second high-frequency power source that supplies a second high-frequency current having a frequency different from that of the first high-frequency current to the second induction coil. 前記金型は、固定型および可動型を含み、前記第１の誘導コイルは、前記固定型の外周面を概ね囲むように配置される一方、前記第２の誘導コイルは、前記可動型の外周面を概ね囲むように配置されていることを特徴とする請求項１に記載のプレス成形装置。The mold includes a fixed mold and a movable mold, and the first induction coil is disposed so as to substantially surround an outer peripheral surface of the fixed mold, while the second induction coil is an outer periphery of the movable mold. The press molding apparatus according to claim 1, wherein the press molding apparatus is disposed so as to substantially surround the surface. 前記第１の誘導コイルと前記第２の誘導コイルとの間には、第１の誘導コイルによる磁場と前記第２の誘導コイルによる磁場との干渉を防止するためのシールド部材が配置されていることを特徴とする請求項１または２に記載のプレス成形装置。A shield member is disposed between the first induction coil and the second induction coil to prevent interference between the magnetic field generated by the first induction coil and the magnetic field generated by the second induction coil. The press molding apparatus according to claim 1 or 2. 前記金型は、固定型および可動型を含み、前記第１の誘導コイルは、前記固定型および前記可動型の双方を加熱することができるように配置される一方、前記第２の誘導コイルは、前記固定型と前記可動型との間に生じた温度差を補正することができるように配置されていることを特徴とする請求項１に記載のプレス成形装置。The mold includes a fixed mold and a movable mold, and the first induction coil is arranged to be able to heat both the fixed mold and the movable mold, while the second induction coil is 2. The press molding apparatus according to claim 1, wherein the press molding apparatus is arranged so as to correct a temperature difference generated between the fixed mold and the movable mold. 金型間の原材料を加熱・加圧することにより所望の成形品をつくり出すプレス成形方法において、
前記金型の周囲に第１の誘導コイルを配置すると共に、前記金型の周囲に更に第２の誘導コイルを配置し、前記第１の誘導コイルに第１の高周波電流を供給する一方、前記第２の誘導コイルに前記第１の高周波電流とは異なる周波数をもった第２の高周波電流を供給して、前記金型および前記原材料を加熱することを特徴とするプレス成形方法。In the press molding method to produce the desired molded product by heating and pressurizing the raw material between the molds,
A first induction coil is disposed around the mold, and a second induction coil is further disposed around the mold to supply a first high-frequency current to the first induction coil, A press molding method, wherein a second high frequency current having a frequency different from the first high frequency current is supplied to a second induction coil to heat the mold and the raw material.
JP2002163421A 2002-06-04 2002-06-04 Press molding apparatus and press molding method Expired - Fee Related JP3932985B2 (en)

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FR2867939B1 (en) * 2004-03-18 2007-08-10 Roctool METHOD FOR HEATING MATERIALS TO PRODUCE OBJECTS AND DEVICE USING THE METHOD
FR2890588B1 (en) * 2005-09-12 2007-11-16 Roctool Soc Par Actions Simpli DEVICE FOR TRANSFORMING MATERIALS USING INDUCTION HEATING
FR2937270B1 (en) * 2008-10-20 2010-11-26 Roctool DEVICE FOR TRANSFORMING MATERIALS USING INDUCTION HEATING FOR PREHEATING THE DEVICE
JP5271325B2 (en) * 2010-09-17 2013-08-21 本田技研工業株式会社 Molding apparatus and molding method
FR2991902A1 (en) * 2012-06-18 2013-12-20 Roctool METHOD AND DEVICE FOR PREHEATING A MOLD IN PARTICULAR INJECTION MOLDING
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